Sample records for lake surface area

  1. The use of total lake-surface area as an indicator of climatic change: Examples from the Lahontan basin

    USGS Publications Warehouse

    Benson, L.V.; Paillet, Frederick L.

    1989-01-01

    Variation in the size of lakes in the Lahontan basin is topographically constrained. River diversion also has played a major role in regulating lake size in Lahontan subbasins. The proper gage of lake response to change in the hydrologic balance is neither lake depth (level) nor lake volume but instead lake-surface area. Normalization of surface area is necessary when comparing surface areas of lakes in basins having different topographies. To a first approximation, normalization can be accomplished by dividing the paleosurface area of a lake by its mean-historical, reconstructed surface area. ?? 1989.

  2. Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

    USGS Publications Warehouse

    Jones, Perry M.; Trost, Jared J.; Erickson, Melinda L.

    2016-10-19

    OverviewThis study assessed lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes applying three approaches: statistical analysis, field study, and groundwater-flow modeling.  Statistical analyses of lake levels were completed to assess the effect of physical setting and climate on lake-level fluctuations of selected lakes. A field study of groundwater and surface-water interactions in selected lakes was completed to (1) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (2) estimate general ages for waters extracted from the wells, and (3) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake.  Groundwater flow was simulated using a steady-state, groundwater-flow model to assess regional groundwater and surface-water exchanges and the effects of groundwater withdrawals, climate, and other factors on water levels of northeast Twin Cities Metropolitan Area lakes.

  3. Bathymetry of Walker Lake, West-Central Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.; Smith, J. LaRue

    2007-01-01

    Walker Lake lies within a topographically closed basin in west-central Nevada and is the terminus of the Walker River. Much of the streamflow in the Walker River is diverted for irrigation, which has contributed to a decline in lake-surface altitude of about 150 feet and an increase in dissolved solids from 2,500 to 16,000 milligrams per liter in Walker Lake since 1882. The increase in salinity threatens the fresh-water ecosystem and survival of the Lahontan cutthroat trout, a species listed as threatened under the Endangered Species Act. Accurately determining the bathymetry and relations between lake-surface altitude, surface area, and storage volume are part of a study to improve the water budget for Walker Lake. This report describes the updated bathymetry of Walker Lake, a comparison of results from this study and a study by Rush in 1970, and an estimate of the 1882 lake-surface altitude. Bathymetry was measured using a single-beam echosounder coupled to a differentially-corrected global positioning system. Lake depth was subtracted from the lake-surface altitude to calculate the altitude of the lake bottom. A Lidar (light detection and ranging) survey and high resolution aerial imagery were used to create digital elevation models around Walker Lake. The altitude of the lake bottom and digital elevation models were merged together to create a single map showing land-surface altitude contours delineating areas that are currently or that were submerged by Walker Lake. Surface area and storage volume for lake-surface altitudes of 3,851.5-4,120 feet were calculated with 3-D surface-analysis software. Walker Lake is oval shaped with a north-south trending long axis. On June 28, 2005, the lake-surface altitude was 3,935.6 feet, maximum depth was 86.3 feet, and the surface area was 32,190 acres. The minimum altitude of the lake bottom from discrete point depths is 3,849.3 feet near the center of Walker Lake. The lake bottom is remarkably smooth except for mounds near the shore and river mouth that could be boulders, tree stumps, logs, or other submerged objects. The echosounder detected what appeared to be mounds in the deepest parts of Walker Lake, miles from the shore and river mouth. However, side-scan sonar and divers did not confirm the presence of mounds. Anomalies occur in two northwest trending groups in northern and southern Walker Lake. It is hypothesized that some anomalies indicate spring discharge along faults based on tufa-like rocks that were observed and the northwest trend parallel to and in proximity of mapped faults. Also, evaporation measured from Walker Lake is about 50 percent more than the previous estimate, indicating more water is flowing into the lake from sources other than the Walker River. Additional studies need to be done to determine what the anomalies are and whether they are related to the hydrology of Walker Lake. Most differences in surface area and storage volume between this study and a study by Rush in 1970 were less than 1 percent. The largest differences occur at lake-surface altitudes less than 3,916 feet. In general, relations between lake-surface altitude, surface area, and storage volume from Rush's study and this study are nearly identical throughout most of the range in lake-surface altitude. The lake-surface altitude in 1882 was estimated to be between 4,080 feet and 4,086 feet with a probable altitude of 4,082 feet. This estimate compares well with two previous estimates of 4,083 feet and 4,086 feet. Researchers believe the historic highstand of Walker Lake occurred in 1868 and estimated the highstand was between 4,089 feet and 4,108 feet. By 1882, Mason Valley was predominantly agricultural. The 7-26 feet decline in lake-surface altitude between 1868 and 1882 could partially be due to irrigation diversions during this time.

  4. Temperate Lakes Discovered on Titan

    NASA Astrophysics Data System (ADS)

    Vixie, Graham; Barnes, Jason W.; Jackson, Brian; Wilson, Paul

    2012-04-01

    We have discovered two temperate lakes on Titan using Cassini's Visual and Infrared Mapping Spectrometer (VIMS). Three key features help to identify these surface features as lakes: morphology, albedo, and specular reflection. The presence of lakes at the mid-latitudes mean liquid can accumulate and remain stable outside of the poles. We first identify a lake surface by looking for possible shorelines with a lacustrine morphology. Then, we apply a simple atmospheric correction that produces an approximate surface albedo. Next, we prepare cylindrical projection maps of the brightness of the sky as seen from any points on the surface to identify specular reflections. Our techniques can then be applied to other areas, such as Arrakis Planitia, to test for liquid. Currently, all the known lakes on Titan are concentrated at the poles. Lakes have been suggested in the tropic zone by Griffith et al. Our discovery of non-transient, temperate lakes has important implications for Titan's hydrologic cycle. Clouds have been recorded accumulating in the mid-latitudes and areas have been darkened by rainfall but later brightened after evaporation (Turtle et al. 2011). Stable temperate lakes would affect total rainfall, liquid accumulation, evaporation rates, and infiltration. Polaznik Macula (Figure 1) is a great candidate for lake filling, evaporation rates, and stability. References: Griffith, C., et al.: "Evidence for Lakes on Titan's Tropical Surface". AAS/Division for Planetary Sciences Meeting Abstracts #42, Vol. 42, pp. 1077, 2010. Turtle, E. P., et al.: "Rapid and Extensive Surface Changes Near Titan's Equator: Evidence of April Showers". Science, Vol. 331, pp. 1414-, 2011. Figure 1: Polaznik Macula is the large, dark area central to the figure. The encircled dark blue areas represent positively identified lake regions in the T66 flyby. The light blue areas represent lake candidates still under analysis. The green circle marks a non-lake surface feature enclosed by a lake.

  5. Response of water temperatures and stratification to changing climate in three lakes with different morphometry

    NASA Astrophysics Data System (ADS)

    Magee, Madeline R.; Wu, Chin H.

    2017-12-01

    Water temperatures and stratification are important drivers for ecological and water quality processes within lake systems, and changes in these with increases in air temperature and changes to wind speeds may have significant ecological consequences. To properly manage these systems under changing climate, it is important to understand the effects of increasing air temperatures and wind speed changes in lakes of different depths and surface areas. In this study, we simulate three lakes that vary in depth and surface area to elucidate the effects of the observed increasing air temperatures and decreasing wind speeds on lake thermal variables (water temperature, stratification dates, strength of stratification, and surface heat fluxes) over a century (1911-2014). For all three lakes, simulations showed that epilimnetic temperatures increased, hypolimnetic temperatures decreased, the length of the stratified season increased due to earlier stratification onset and later fall overturn, stability increased, and longwave and sensible heat fluxes at the surface increased. Overall, lake depth influences the presence of stratification, Schmidt stability, and differences in surface heat flux, while lake surface area influences differences in hypolimnion temperature, hypolimnetic heating, variability of Schmidt stability, and stratification onset and fall overturn dates. Larger surface area lakes have greater wind mixing due to increased surface momentum. Climate perturbations indicate that our larger study lakes have more variability in temperature and stratification variables than the smaller lakes, and this variability increases with larger wind speeds. For all study lakes, Pearson correlations and climate perturbation scenarios indicate that wind speed has a large effect on temperature and stratification variables, sometimes greater than changes in air temperature, and wind can act to either amplify or mitigate the effect of warmer air temperatures on lake thermal structure depending on the direction of local wind speed changes.

  6. Ground-water/surface-water interaction in nearshore areas of Three Lakes on the Grand Portage Reservation, northeastern Minnesota, 2003-04

    USGS Publications Warehouse

    Jones, Perry M.

    2006-01-01

    Knowledge of general water-flow directions in lake watersheds and how they may change seasonally can help water-quality specialists and lake managers address a variety of water-quality and aquatic habitat protection issues for lakes. Results from this study indicate that ground-water and surface-water interactions at the study lakes are complex, and the ability of the applied techniques to identify ground-water inflow and surface-water outseepage locations varied among the lakes. Measurement of lake-sediment temperatures proved to be a reliable and relatively inexpensive reconnaissance technique that lake managers may apply in complex settings to identify general areas of ground-water inflow and surface-water outseepage.

  7. Simulating Lake-Groundwater Interactions During Decadal Climate Cycles: Accounting For Variable Lake Area In The Watershed

    NASA Astrophysics Data System (ADS)

    Virdi, M. L.; Lee, T. M.

    2009-12-01

    The volume and extent of a lake within the topo-bathymetry of a watershed can change substantially during wetter and drier climate cycles, altering the interaction of the lake with the groundwater flow system. Lake Starr and other seepage lakes in the permeable sandhills of central Florida are vulnerable to climate changes as they rely exclusively on rainfall and groundwater for inflows in a setting where annual rainfall and recharge vary widely. The groundwater inflow typically arrives from a small catchment area bordering the lake. The sinkhole origin of these lakes combined with groundwater pumping from underlying aquifers further complicate groundwater interactions. Understanding the lake-groundwater interactions and their effects on lake stage over multi-decadal climate cycles is needed to manage groundwater pumping and public expectation about future lake levels. The interdependence between climate, recharge, changing lake area and the groundwater catchment pose unique challenges to simulating lake-groundwater interactions. During the 10-year study period, Lake Starr stage fluctuated more than 13 feet and the lake surface area receded and expanded from 96 acres to 148 acres over drier and wetter years that included hurricanes, two El Nino events and a La Nina event. The recently developed Unsaturated Zone Flow (UZF1) and Lake (LAK7) packages for MODFLOW-2005 were used to simulate the changing lake sizes and the extent of the groundwater catchment contributing flow to the lake. The lake area was discretized to occupy the largest surface area at the highest observed stage and then allowed to change size. Lake cells convert to land cells and receive infiltration as receding lake area exposes the underlying unsaturated zone to rainfall and recharge. The unique model conceptualization also made it possible to capture the dynamic size of the groundwater catchment contributing to lake inflows, as the surface area and volume of the lake changed during the study period. Groundwater flows simulated using daily time steps over a 10-year period were used to describe the relationship between climate, the size of the groundwater catchment, and the relative importance of groundwater inflow to the lake water budget. Modeling approaches used in this study should be applicable to other surface-water bodies such as wetlands and playa lakes. Lake Starr watershed (depressions from sinkholes)

  8. Hydrology of the Lake Deaton and Lake Okahumpka area, Northeast Sumter County, Florida

    USGS Publications Warehouse

    Simonds, Edward P.; German, E.R.

    1980-01-01

    The Floridan aquifer in the Lake Deaton and Lake Okahumpka area is 50 to 130 feet below land surface. During the 16-year period 1963-78 lake evaporation exceeded rainfall by 0.4 inches. Drainage from Lake Deaton and its surrounding area goes into Chitty Chatty Creek and on the Hogeye Sink when the altitude of the potentiometric surface of the Floridan aquifer is low. During a higher altitude of the Floridan potentiometric surface, Hogeye Sink may discharge water; this water, along with the normal runoff, goes into Lake Okahumpka. Average lake fluctuation is 1.5 to 2.0 feet per year. Lake Deaton supports a large population of blue-green algae and Lake Okahumpka is choked with aquatic plants. The water quality of the two lakes differ, with Lake Deaton having a sodium chloride water and Lake Okahumpka having a calcium bicarbonate water. Analysis of water and bottom material samples showed that only cadmium and mercury exceeded the Florida Department of Environmental Regulation 's criteria for Class III waters; however, the amounts detected were at or slightly above the limits of the analytical method. (USGS)

  9. Changes in surface area of the Böön Tsagaan and Orog lakes (Mongolia, Valley of the Lakes, 1974-2013) compared to climate and permafrost changes

    NASA Astrophysics Data System (ADS)

    Szumińska, Danuta

    2016-07-01

    The main aim of the study is the analysis of changes in surface area of lake Böön Tsagaan (45°35‧N, 99°8‧E) and lake Orog (45°3‧N, 100°44‧E) taking place in the last 40 years in the context of climate conditions and permafrost degradation. The lakes, located in Central Mongolia, at the borderline of permafrost range are fed predominantly by river waters and groundwater from the surrounding mountain areas, characterized by continuous and discontinuous permafrost occurrence - mostly the Khangai. The analysis of the Böön Tsagaan and Orog lake surface area in 1974-2013 was conducted based on satellite images, whereas climate conditions were analysed using the NOAA climate data and CRU dataset. Principal Component Analysis (PCA) was used to study the relationship patterns between the climatic factors and changes in the surface area of the lakes. A tendency for a decrease in surface area, intermittent with short episodes of resupply, was observed in both studied lakes. Climate changes recorded in the analysed period had both direct and indirect impacts on water supply to lakes. Taking into account the results of PCA analysis, the most significant factors include: fluctuation of annual precipitation, increase in air temperature and thickness of snow cover. The extended duration of snow cover in the last decades of the 20th century may constitute a key factor in relation to permafrost degradation.

  10. Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI

    PubMed Central

    Kang, Sinkyu; Hong, Suk Young

    2016-01-01

    A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km2in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km2. The lake area decreased by -9.3% at an annual rate of -53.7 km2 yr-1 during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability. PMID:27007233

  11. Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI.

    PubMed

    Kang, Sinkyu; Hong, Suk Young

    2016-01-01

    A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km2in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km(2). The lake area decreased by -9.3% at an annual rate of -53.7 km(2) yr(-1) during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability.

  12. Statistical analysis of lake levels and field study of groundwater and surface-water exchanges in the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015: Chapter A of Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

    USGS Publications Warehouse

    Jones, Perry M.; Trost, Jared J.; Diekoff, Aliesha L.; Rosenberry, Donald O.; White, Eric A.; Erickson, Melinda L.; Morel, Daniel L.; Heck, Jessica M.

    2016-10-19

    Water levels declined from 2003 to 2011 in many lakes in Ramsey and Washington Counties in the northeast Twin Cities Metropolitan Area, Minnesota; however, water levels in other northeast Twin Cities Metropolitan Area lakes increased during the same period. Groundwater and surface-water exchanges can be important in determining lake levels where these exchanges are an important component of the water budget of a lake. An understanding of groundwater and surface-water exchanges in the northeast Twin Cities Metropolitan Area has been limited by the lack of hydrologic data. The U.S. Geological Survey, in cooperation with the Metropolitan Council and Minnesota Department of Health, completed a field and statistical study assessing lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes. This report documents the analysis of collected hydrologic, water-quality, and geophysical data; and existing hydrologic and geologic data to (1) assess the effect of physical setting and climate on lake-level fluctuations of selected lakes, (2) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (3) estimate general ages for waters extracted from the wells, and (4) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake. Statistical analyses of lake levels during short-term (2002–10) and long-term (1925–2014) periods were completed to help understand lake-level changes across the northeast Twin Cities Metropolitan Area. Comparison of 2002–10 lake levels to several landscape and geologic characteristics explained variability in lake-level changes for 96 northeast Twin Cities Metropolitan Area lakes. Application of several statistical methods determined that (1) closed-basin lakes (without an active outlet) had larger lake-level declines than flow-through lakes with an outlet; (2) closed-basin lake-level changes reflected groundwater-level changes in the Quaternary, Prairie du Chien, and Jordan aquifers; (3) the installation of outlet-control structures, such as culverts and weirs, resulted in smaller multiyear lake-level changes than lakes without outlet-control structures; (4) water levels in lakes primarily overlying Superior Lobe deposits were significantly more variable than lakes primarily overlying Des Moines Lobe deposits; (5) lake-level declines were larger with increasing mean lake-level elevation; and (6) the frequency of some of these characteristics varies by landscape position. Flow-through lakes and lakes with outlet-control structures were more common in watersheds with more than 50 percent urban development compared to watersheds with less than 50 percent urban development. A comparison of two 35-year periods during 1925–2014 revealed that variability of annual mean lake levels in flow-through lakes increased when annual precipitation totals were more variable, whereas variability of annual mean lake levels in closed-basin lakes had the opposite pattern, being more variable when annual precipitation totals were less variable. Oxygen-18/oxygen-16 and hydrogen-2/hydrogen-1 ratios for water samples from 40 wells indicated the well water was a mixture of surface water and groundwater in 31 wells, whereas ratios from water sampled from 9 other wells indicated that water from these wells receive no surface-water contribution. Of the 31 wells with a mixture of surface water and groundwater, 11 were downgradient from White Bear Lake, likely receiving water from deeper parts of the lake. Age dating of water samples from wells indicated that the age of water in the Prairie du Chien and Jordan aquifers can vary widely across the northeast Twin Cities Metropolitan Area. Estimated ages of recharge for 9 of the 40 wells sampled for chlorofluorocarbon concentrations ranged widely from the early 1940s to mid-1970s. The wide range in estimated ages of recharge may have resulted from the wide range in the open-interval lengths and depths for the wells.Results from stable isotope analyses of water samples, lake-sediment coring, continuous seismic-reflection profiling, and water-level and flow monitoring indicated that there is groundwater inflow from nearshore sites and lake-water outflow from deep-water sites in White Bear Lake. Continuous seismic-reflection profiling indicated that deep sections of White Bear, Pleasant, Turtle, and Big Marine Lakes have few trapped gases and little organic material, which indicates where groundwater and lake-water exchanges are more likely. Water-level differences between White Bear Lake and piezometer and seepage measurements in deep waters of the lake indicate that groundwater and lake-water exchange is happening in deep waters, predominantly downgradient from the lake and into the lake sediment. Seepage fluxes measured in the nearshore sites of White Bear Lake generally were higher than seepage fluxes measured in the deep-water sites, which indicates that groundwater-inflow rates at most of the nearshore sites are higher than lake-water outflow from the deep-water sites.

  13. Mechanisms influencing changes in lake area in Alaskan boreal forest

    USGS Publications Warehouse

    Roach, Jennifer K.; Griffith, Brad; Verbyla, David; Jones, Jeremy B.

    2011-01-01

    During the past ∼50 years, the number and area of lakes have declined in several regions in boreal forests. However, there has been substantial finer-scale heterogeneity; some lakes decreased in area, some showed no trend, and others increased. The objective of this study was to identify the primary mechanisms underlying heterogeneous trends in closed-basin lake area. Eight lake characteristics (δ18O, electrical conductivity, surface : volume index, bank slope, floating mat width, peat depth, thaw depth at shoreline, and thaw depth at the forest boundary) were compared for 15 lake pairs in Alaskan boreal forest where one lake had decreased in area since ∼1950, and the other had not. Mean differences in characteristics between paired lakes were used to identify the most likely of nine mechanistic scenarios that combined three potential mechanisms for decreasing lake area (talik drainage, surface water evaporation, and terrestrialization) with three potential mechanisms for nondecreasing lake area (subpermafrost groundwater recharge through an open talik, stable permafrost, and thermokarst). A priori expectations of the direction of mean differences between decreasing and nondecreasing paired lakes were generated for each scenario. Decreasing lakes had significantly greater electrical conductivity, greater surface : volume indices, shallower bank slopes, wider floating mats, greater peat depths, and shallower thaw depths at the forest boundary. These results indicated that the most likely scenario was terrestrialization as the mechanism for lake area reduction combined with thermokarst as the mechanism for nondecreasing lake area. Terrestrialization and thermokarst may have been enhanced by recent warming which has both accelerated permafrost thawing and lengthened the growing season, thereby increasing plant growth, floating mat encroachment, transpiration rates, and the accumulation of organic matter in lake basins. The transition to peatlands associated with terrestrialization may provide a transient increase in carbon storage enhancing the role of northern ecosystems as major stores of global carbon.

  14. Does lake size matter? Combining morphology and process modeling to examine the contribution of lake classes to population-scale processes

    USGS Publications Warehouse

    Winslow, Luke A.; Read, Jordan S.; Hanson, Paul C.; Stanley, Emily H.

    2014-01-01

    With lake abundances in the thousands to millions, creating an intuitive understanding of the distribution of morphology and processes in lakes is challenging. To improve researchers’ understanding of large-scale lake processes, we developed a parsimonious mathematical model based on the Pareto distribution to describe the distribution of lake morphology (area, perimeter and volume). While debate continues over which mathematical representation best fits any one distribution of lake morphometric characteristics, we recognize the need for a simple, flexible model to advance understanding of how the interaction between morphometry and function dictates scaling across large populations of lakes. These models make clear the relative contribution of lakes to the total amount of lake surface area, volume, and perimeter. They also highlight the critical thresholds at which total perimeter, area and volume would be evenly distributed across lake size-classes have Pareto slopes of 0.63, 1 and 1.12, respectively. These models of morphology can be used in combination with models of process to create overarching “lake population” level models of process. To illustrate this potential, we combine the model of surface area distribution with a model of carbon mass accumulation rate. We found that even if smaller lakes contribute relatively less to total surface area than larger lakes, the increasing carbon accumulation rate with decreasing lake size is strong enough to bias the distribution of carbon mass accumulation towards smaller lakes. This analytical framework provides a relatively simple approach to upscaling morphology and process that is easily generalizable to other ecosystem processes.

  15. iss031e148455

    NASA Image and Video Library

    2012-06-21

    ISS031-E-148455 (21 June 2012) --- Toshka Lakes in southern Egypt are featured in this image photographed by an Expedition 31 crew member on the International Space Station. The Toshka Lakes (center) were formed in the Sahara Desert of Egypt by water from the River Nile conveyed from Lake Nasser by a canal to the Toshka Depression. Flooding of the Toshka Depression had created the four main lakes with a maximum surface area in 2002 of approximately 1,450 square kilometers ? around 25.26 billion cubic meters of water. By 2006 the stored water was reduced by 50 per cent and by 2012 shows open water only in the lowest parts of the main western and eastern basins?representing a reduction in surface area to 307 square kilometers?nearly 80 per cent smaller than the 2002 surface area. Standing water is almost completely absent from the central basin. From space, astronauts documented the first lake?the easternmost one?in 1998. The lakes progressively grew in depressions to the west, the westernmost filling between 2000 and 2001. This image shows lines of center-point agricultural fields near the east-basin lake nearest Lake Nasser. Sunglint on the western lake makes the water surface appear both light and dark, depending on which parts of the surface were ruffled by the wind at the moment the image was taken.

  16. Landscape influences on climate-related lake shrinkage at high latitudes

    USGS Publications Warehouse

    Roach, Jennifer K.; Griffith, Brad; Verbyla, David

    2013-01-01

    Climate-related declines in lake area have been identified across circumpolar regions and have been characterized by substantial spatial heterogeneity. An improved understanding of the mechanisms underlying lake area trends is necessary to predict where change is most likely to occur and to identify implications for high latitude reservoirs of carbon. Here, using a population of ca. 2300 lakes with statistically significant increasing and decreasing lake area trends spanning longitudinal and latitudinal gradients of ca. 1000 km in Alaska, we present evidence for a mechanism of lake area decline that involves the loss of surface water to groundwater systems. We show that lakes with significant declines in lake area were more likely to be located: (1) in burned areas; (2) on coarser, well-drained soils; and (3) farther from rivers compared to lakes that were increasing. These results indicate that postfire processes such as permafrost degradation, which also results from a warming climate, may promote lake drainage, particularly in coarse-textured soils and farther from rivers where overland flooding is less likely and downslope flow paths and negative hydraulic gradients between surface water and groundwater systems are more common. Movement of surface water to groundwater systems may lead to a deepening of subsurface flow paths and longer hydraulic residence time which has been linked to increased soil respiration and CO2 release to the atmosphere. By quantifying relationships between statewide coarse resolution maps of landscape characteristics and spatially heterogeneous responses of lakes to environmental change, we provide a means to identify at-risk lakes and landscapes and plan for a changing climate.

  17. Monitoring and Assessment of Hydrological and Ecological Changes in Lake Manyas

    NASA Astrophysics Data System (ADS)

    Curebal, Isa; Efe, Recep; Soykan, Abdullah; Sonmez, Suleyman

    2014-05-01

    Manyas Lake in the northwest of Turkey occupies an area of 165 square kilometers. The surface area of the lake is continuously changing due to human activities, hydrologic and climatic conditions. The objective of this study is to examine the changes in water level and the area of lake and the effects of these changes on the lake's ecosystem and human economic activities. In order to determine the changes lake level measurement data, 1/25000 scale topography maps, rainfall and temperature data and bathymetry maps were used and elevation models were made. During the study period the water level fluctuated between 14.0 and 17.8 meters, and surface area changed between 124,8 km2 and 170,6 km2 respectively. Prior to the construction of a flood barrier at the southern end of the lake in 1992 the maximum surface area of the lake was calculated at 209 km2. Lake Manyas is an important wetland on the route of migration of birds from/to Europe and Africa. 64 ha of the lake and its surroundings along with the entire National Park is a Ramsar site. Irrigated and dry farming is practiced around the lake and fishing is important economic activity. The changes in the water level as result of natural and human factors brought about negative effects on the lake's ecosystem in last ten years. Result of these effects, natural fluctuation of the lake changed and the marshes around the lake destroyed and the bird population decreased. Lowering the water level in the lake is also significantly reduced the number of fish and number of migratory birds. The construction of the flood barrier destroyed vegetation and bird life in about a 25% of area of the lake on the south. The natural ecosystem in this area has been adversely affected. Moreover, when the water level is low due to low rain fall and irrigation, vegetation on the lake's shore line dies and some areas turn to swamp. The fauna and flora are negatively affected by water level changes particularly in the protected National Park area.

  18. Wind variability and sheltering effects on measurements and modeling of air-water exchange for a small lake

    NASA Astrophysics Data System (ADS)

    Markfort, Corey D.; Resseger, Emily; Porté-Agel, Fernando; Stefan, Heinz

    2014-05-01

    Lakes with a surface area of less than 10 km2 account for over 50% of the global cumulative lake surface water area, and make up more than 99% of the total number of global lakes, ponds, and wetlands. Within the boreal regions as well as some temperate and tropical areas, a significant proportion of land cover is characterized by lakes or wetlands, which can have a dramatic effect on land-atmosphere fluxes as well as the local and regional energy budget. Many of these small water bodies are surrounded by complex terrain and forest, which cause the wind blowing over a small lake or wetland to be highly variable. Wind mixing of the lake surface layer affects thermal stratification, surface temperature and air-water gas transfer, e.g. O2, CO2, and CH4. As the wind blows from the land to the lake, wake turbulence behind trees and other shoreline obstacles leads to a recirculation zone and enhanced turbulence. This wake flow results in the delay of the development of wind shear stress on the lake surface, and the fetch required for surface shear stress to fully develop may be ~O(1 km). Interpretation of wind measurements made on the lake is hampered by the unknown effect of wake turbulence. We present field measurements designed to quantify wind variability over a sheltered lake. The wind data and water column temperature profiles are used to evaluate a new method to quantify wind sheltering of lakes that takes into account lake size, shape and the surrounding landscape features. The model is validated against field data for 36 Minnesota lakes. Effects of non-uniform sheltering and lake shape are also demonstrated. The effects of wind sheltering must be included in lake models to determine the effect of wind-derived energy inputs on lake stratification, surface gas transfer, lake water quality, and fish habitat. These effects are also important for correctly modeling momentum, heat, moisture and trace gas flux to the atmosphere.

  19. Lakes and lake-like waters of the Hawaiian Archipelago

    USGS Publications Warehouse

    Maciolek, J.A.

    1982-01-01

    This summary of Hawaiian lacustrine limnology is based on 12 years of field and literature surveys of archipelagic inland waters. Lakes here are distinguished from other standing waters by limits on surface oceanic area (> 0.1 ha) and depth (> 2 m), and by the absence of flatural surface oceanic connection. A variety of extinct and existing water bodies, sometimes referred to as lakes, are noted. Six lakes are described. Five of them are in crater basins, 3 are freshwater, and 2 are elevated (highest = 3969 m). The scarcity of elevated lakes results from general permeability of the substrata. Among the 6 lakes, surface areas range from 0.22 to 88 ha and maximum depths from 3 to 248 m. Naturally occurring aquatic biota generally is low in species diversity except for phytoplankton; fishes and submersed vascular plants are absent. Two lowland lakes, freshwater Green (Wai a Pele) and saline Kauhak6, are described for the first time. Profundal Kauhak6, 248 m deep, has a surface area of only 0.35 ha, which results in an extraordinary relative depth of 370%. It is permanently stratified, a condition apparently due primarily to the unique morphometry of its basin. 

  20. Fluvial sediment study of Fishtrap and Dewey Lakes drainage basins, Kentucky - Virginia

    USGS Publications Warehouse

    Curtis, William F.; Flint, Russell F.; George, Frederick H.; Santos, John F.

    1978-01-01

    Fourteen drainage basins above Fishtrap and Dewey Lakes in the Levisa Fork and Johns Creek drainage basins of eastern Kentucky and southwestern Virginia were studied to determine sedimentation rates and origin of sediment entering the two lakes. The basins ranged in size from 1.68 to 297 square miles. Sediment yields ranged from 2,890 to 21,000 tons per square mile where surface-mining techniques predominated, and from 732 to 3 ,470 tons per square mile where underground mining methods predominated. Yields, in terms of tons per acre-foot of runoff, ranged from 2.2 to 15 for surface-mined areas, and from 0.5 to 2.7 for underground-mined areas. Water and sediment discharges from direct runoff during storms were compared for selected surface-mined and underground-mined areas. Data points of two extensively surface-mined areas, one from the current project and one from a previous project in Beaver Creek basin, McCreary County, Kentucky, grouped similarly in magnitude and by season. Disturbed areas from mining activities determined from aerial photographs reached 17 percent in one study area where extensive surface mining was being practiced. For most areas where underground mining was practiced, percentage disturbed area was almost negligible. Trap efficiency of Fishtrap Lake was 89 percent, and was 62 percent for Dewey Lake. Average annual deposition rates were 464 and 146 acre-feet for Fishtrap and Dewey Lakes, respectively. The chemical quality of water in the Levisa Fork basin has been altered by man 's activities. (Woodard-USGS)

  1. Glacial Lake Growth and Associated Glacier Dynamics: Case Study from the Himalayas, Andes, Alaska and New Zealand

    NASA Astrophysics Data System (ADS)

    Binger, D. J.; Haritashya, U. K.; Kargel, J. S.; Shugar, D. H.

    2016-12-01

    Glacial lake growth and associated glacier dynamics: Case study from the Himalayas, Andes, Alaska and New Zealand David J. Binger1, Umesh K. Haritashya1 and Jeffrey S. Kargel21University of Dayton, Dayton, OH 2University of Arizona, Tucson, AZ As a result of climate change most of the world's alpine glaciers are undergoing measurable retreat and dynamic changes. The result of accelerated melting has led to the formation and growth of potentially dangerous glacial lakes. In this study, alpine glaciers and associated lakes from the Himalayas, Andes, Alaska and New Zealand, showing similar geomorphological settings were analyzed to compare differences in regional proglacial lake growth and its relationship with glacier dynamics. Specifically, we analyzed the surface area growth of the lakes, retreat of glacier terminus, changes in glacier velocity, surface temperature and potential glacial lake outburst flood triggers. Using Landsat and ASTER satellite images, Cosi - Corr software, and in house thermal mapping, 10 glaciers were analyzed and compared. Results show a substantial increase in proglacial lake surface area, accelerated velocity and significant calving of the glaciers. Glacier surface temperatures varied by location, with some remaining constant and others 2°C - 4°C increases; although increased surface temperature did not always show a direct correlation with increasing retreat rate. Lakes with high rates of surface area growth paired with glaciers with increased velocity and calving could prove to be unsustainable and lead to an increased risk for glacial lake outburst floods. Overall, result show the changing dynamics of the alpine glaciers in different mountain regions and the growth of their proglacial lakes.

  2. Geohydrology of the lowland lakes area, Anchorage, Alaska

    USGS Publications Warehouse

    Zenone, Chester

    1976-01-01

    Unconsolidated deposits, chiefly of glacial origin, make up the surficial geologic materials in the Anchorage lowland lakes area , the western part of the Anchorage glacial outwash plain. Postglacial accumulation of peat, commonly 5 to 10 feet thick, and the presence of ground water at or very near the surface combine to create the swamp-muskeg terrane of much of the area. Deeper, confined ground water is also present beneath thick silt and clay layers that underlie the surficial deposits. Domestic water supply for the lowland lakes area is provided largely by public-supply wells completed in the deep, confined aquifers. No large perennial streams traverse the area, thus streamflow is not a major parameter in the area 's natural water balance. The major uses of surface water are recreational, including fishing and boating at several of the larger lakes, and private and commercial aircraft operations at Hood-Spenard Lakes floatplane base. The hydrology and water balance of these lakes is complex. Water levels in some lakes appear to be closely related to adjacent ground-water levels. Other lakes are evidently perched above the local water table. The relation of lake level to adjacent ground-water level may vary along the shoreline of a single lake. The effect of residential development practices on lake basin water balance is not completely understood. At Sand Lake, the largest lake in this area of rapid urbanization, the water level has declined about 6 feet since the early 1960's. (Woodard-USGS)

  3. Groundwater and surface-water interactions near White Bear Lake, Minnesota, through 2011

    USGS Publications Warehouse

    Jones, Perry M.; Trost, Jared J.; Rosenberry, Donald O.; Jackson, P. Ryan; Bode, Jenifer A.; O'Grady, Ryan M.

    2013-01-01

    The U.S. Geological Survey, in cooperation with the White Bear Lake Conservation District, the Minnesota Pollution Control Agency, the Minnesota Department of Natural Resources, and other State, county, municipal, and regional planning agencies, watershed organizations, and private organizations, conducted a study to characterize groundwater and surface-water interactions near White Bear Lake through 2011. During 2010 and 2011, White Bear Lake and other lakes in the northeastern part of the Twin Cities Metropolitan Area were at historically low levels. Previous periods of lower water levels in White Bear Lake correlate with periods of lower precipitation; however, recent urban expansion and increased pumping from the Prairie du Chien-Jordan aquifer have raised the question of whether a decline in precipitation is the primary cause for the recent water-level decline in White Bear Lake. Understanding and quantifying the amount of groundwater inflow to a lake and water discharge from a lake to aquifers is commonly difficult but is important in the management of lake levels. Three methods were used in the study to assess groundwater and surface-water interactions on White Bear Lake: (1) a historical assessment (1978-2011) of levels in White Bear Lake, local groundwater levels, and their relation to historical precipitation and groundwater withdrawals in the White Bear Lake area; (2) recent (2010-11) hydrologic and water-quality data collected from White Bear Lake, other lakes, and wells; and (3) water-balance assessments for White Bear Lake in March and August 2011. An analysis of covariance between average annual lake-level change and annual precipitation indicated the relation between the two variables was significantly different from 2003 through 2011 compared with 1978 through 2002, requiring an average of 4 more inches of precipitation per year to maintain the lake level. This shift in the linear relation between annual lake-level change and annual precipitation indicated the net effect of the non-precipitation terms on the water balance has changed relative to precipitation. The average amount of precipitation required each year to maintain the lake level has increased from 33 inches per year during 1978-2002 to 37 inches per year during 2003-11. The combination of lower precipitation and an increase in groundwater withdrawals can explain the change in the lake-level response to precipitation. Annual and summer groundwater withdrawals from the Prairie du Chien-Jordan aquifer have more than doubled from 1980 through 2010. Results from a regression model constructed with annual lake-level change, annual precipitation minus evaporation, and annual volume of groundwater withdrawn from the Prairie du Chien-Jordan aquifer indicated groundwater withdrawals had a greater effect than precipitation minus evaporation on water levels in the White Bear Lake area for all years since 2003. The recent (2003-11) decline in White Bear Lake reflects the declining water levels in the Prairie du Chien-Jordan aquifer; increases in groundwater withdrawals from this aquifer are a likely cause for declines in groundwater levels and lake levels. Synoptic, static groundwater-level and lake-level measurements in March/April and August 2011 indicated groundwater was potentially flowing into White Bear Lake from glacial aquifers to the northeast and south, and lake water was potentially discharging from White Bear Lake to the underlying glacial and Prairie du Chien-Jordan aquifers and glacial aquifers to the northwest. Groundwater levels in the Prairie du Chien-Jordan aquifer below White Bear Lake are approximately 0 to 19 feet lower than surface-water levels in the lake, indicating groundwater from the aquifer likely does not flow into White Bear Lake, but lake water may discharge into the aquifer. Groundwater levels from March/April to August 2011 declined more than 10 feet in the Prairie du Chien-Jordan aquifer south of White Bear Lake and to the north in Hugo, Minnesota. Water-quality analyses of pore water from nearshore lake-sediment and well-water samples, seepage-meter measurements, and hydraulic-head differences measured in White Bear Lake also indicated groundwater was potentially flowing into White Bear Lake from shallow glacial aquifers to the east and south. Negative temperature anomalies determined in shallow waters in the water-quality survey conducted in White Bear Lake indicated several shallow-water areas where groundwater may be flowing into the lake from glacial aquifers below the lake. Cool lake-sediment temperatures (less than 18 degrees Celsius) were measured in eight areas along the northeast, east, south, and southwest shores of White Bear Lake, indicating potential areas where groundwater may flow into the lake. Stable isotope analyses of well-water, precipitation, and lake-water samples indicated wells downgradient from White Bear Lake screened in the glacial buried aquifer or open to the Prairie du Chien-Jordan aquifer receive a mixture of surface water and groundwater; the largest surface-water contributions are in wells closer to White Bear Lake. A wide range in oxygen-18/oxygen-16 and deuterium/protium ratios was measured in well-water samples, indicating different sources of water are supplying water to the wells. Well water with oxygen-18/oxygen-16 and deuterium/protium ratios that plot close to the meteoric water line consisted mostly of groundwater because deuterium/protium ratios for most groundwater usually are similar to ratios for rainwater and snow, plotting close to meteoric water lines. Well water with oxygen-18/oxygen-16 and deuterium/protium ratios that plot between the meteoric water line and ratios for the surface-water samples from White Bear Lake consists of a mixture of surface water and groundwater; the percentage of each source varies relative to its ratios. White Bear Lake is the likely source of the surface water to the wells that have a mixture of surface water and groundwater because (1) it is the only large, deep lake near these wells; (2) these wells are near and downgradient from White Bear Lake; and (3) these wells obtain their water from relatively deep depths, and White Bear Lake is the deepest lake in that area. The percentages of surface-water contribution to the three wells screened in the glacial buried aquifer receiving surface water were 16, 48, and 83 percent. The percentages of surface-water contribution ranged from 5 to 79 percent for the five wells open to the Prairie du Chien-Jordan aquifer receiving surface water; wells closest to White Bear Lake had the largest percentages of surface-water contribution. Water-balance analysis of White Bear Lake in March and August 2011 indicated a potential discharge of 2.8 and 4.5 inches per month, respectively, over the area of the lake from the lake to local aquifers. Most of the sediments from a 12.4-foot lake core collected at the deepest part of White Bear Lake consisted of silts, sands, and gravels likely slumped from shallower waters, with a very low amount of low-permeability, organic material.

  4. Storage Capacity and Water Quality of Lake Ngardok, Babeldaob Island, Republic of Palau, 1996-98

    USGS Publications Warehouse

    Yeung, Chiu Wang; Wong, Michael F.

    1999-01-01

    A bathymetric survey conducted during March and April, 1996, determined the total storage capacity Lake Ngardok to be between 90 and 168 acre-feet. Elevation-surface area and elevation-capacity curves summarizing the current relations among elevation, surface area, and storage capacity were created from the bathymetric map. Rainfall and lake-elevation data collected from April 1996 to March 1998 indicated that lake levels correlated to rainfall values with lake elevation rising rapidly in response to heavy rainfall and then returning to normal levels within a few days. Mean lake elevation for the 22 month period of data was 59.5 feet which gives a mean storage capacity of 107 acre-feet and a mean surface area of 24.1 acre. A floating mat of reeds, which covered 58 percent of the lake surface area at the time of the bathymetric survey, makes true storage capacity difficult to estimate. Water-quality sampling during April 1996 and November 1997 indicated that no U.S. Environmental Protection Agency primary drinking-water standards were violated for analyzed organic and inorganic compounds and radionuclides. With suitable biological treatment, the lake water could be used for drinking-water purposes. Temperature and dissolved oxygen measurements indicated that Lake Ngardok is stratified. Given that air temperature on Palau exhibits little seasonal variation, it is likely that this pattern of stratification is persistent. As a result, complete mixing of the lake is probably rare. Near anaerobic conditions exist at the lake bottom. Low dissolved oxygen (3.2 milligrams per liter) measured at the outflow indicated that water flowing past the outflow was from the deep oxygen-depleted depths of the lake.

  5. Simulation and assessment of groundwater flow and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2003 through 2013: Chapter B of Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

    USGS Publications Warehouse

    Jones, Perry M.; Roth, Jason L.; Trost, Jared J.; Christenson, Catherine A.; Diekoff, Aliesha L.; Erickson, Melinda L.

    2017-09-05

    Water levels during 2003 through 2013 were less than mean water levels for the period 1925–2013 for several lakes in the northeast Twin Cities Metropolitan Area in Minnesota. Previous periods of low lake-water levels generally were correlated with periods with less than mean precipitation. Increases in groundwater withdrawals and land-use changes have brought into question whether or not recent (2003–13) lake-water-level declines are solely caused by decreases in precipitation. A thorough understanding of groundwater and surface-water exchanges was needed to assess the effect of water-management decisions on lake-water levels. To address this need, the U.S. Geological Survey, in cooperation with the Metropolitan Council and the Minnesota Department of Health, developed and calibrated a three-dimensional, steady-state groundwater-flow model representing 2003–13 mean hydrologic conditions to assess groundwater and lake-water exchanges, and the effects of groundwater withdrawals and precipitation on water levels of 96 lakes in the northeast Twin Cities Metropolitan Area.Lake-water budgets for the calibrated groundwater-flow model indicated that groundwater is flowing into lakes in the northeast Twin Cities Metropolitan Area and lakes are providing water to underlying aquifers. Lake-water outflow to the simulated groundwater system was a major outflow component for Big Marine Lake, Lake Elmo, Snail Lake, and White Bear Lake, accounting for 45 to 64 percent of the total outflows from the lakes. Evaporation and transpiration from the lake surface ranged from 19 to 52 percent of the total outflow from the four lakes. Groundwater withdrawals and precipitation were varied from the 2003‒13 mean values used in the calibrated model (30-percent changes in groundwater withdrawals and 5-percent changes in precipitation) for hypothetical scenarios to assess the effects of groundwater withdrawals and precipitation on water budgets and levels in Big Marine Lake, Snail Lake, and White Bear Lake. Simulated lake-water levels and budgets for Snail Lake and White Bear Lake were affected by 30-percent changes in groundwater withdrawals and 5-percent changes in precipitation in the area, whereas the water level in Big Marine Lake was mainly affected by 5-percent precipitation changes. The effects of groundwater withdrawals on the lake-water levels depend on the number of wells and amount of withdrawals from wells near the lakes. Although lake-water levels are sensitive to precipitation changes, increases in groundwater withdrawals during dry periods exacerbate lake-water level declines. The calibrated, groundwater-flow model is a tool that water-resources managers can use to address future water management issues in the northeast Twin Cities Metropolitan Area.

  6. Modeling Lake Storage Dynamics to support Arctic Boreal Vulnerability Experiment (ABoVE)

    NASA Astrophysics Data System (ADS)

    Vimal, S.; Lettenmaier, D. P.; Smith, L. C.; Smith, S.; Bowling, L. C.; Pavelsky, T.

    2017-12-01

    The Arctic and Boreal Zone (ABZ) of Canada and Alaska includes vast areas of permafrost, lakes, and wetlands. Permafrost thawing in this area is expected to increase due to the projected rise of temperature caused by climate change. Over the long term, this may reduce overall surface water area, but in the near-term, the opposite is being observed, with rising paludification (lake/wetland expansion). One element of NASA's ABoVE field experiment is observations of lake and wetland extent and surface elevations using NASA's AirSWOT airborne interferometric radar, accompanied by a high-resolution camera. One use of the WSE retrievals will be to constrain model estimates of lake storage dynamics. Here, we compare predictions using the lake dynamics algorithm within the Variable Infiltration Capacity (VIC) land surface scheme. The VIC lake algorithm includes representation of sub-grid topography, where the depth and area of seasonally-flooded areas are modeled as a function of topographic wetness index, basin area, and slope. The topography data used is from a new global digital elevation model, MERIT-DEM. We initially set up VIC at sites with varying permafrost conditions (i.e., no permafrost, discontinuous, continuous) in Saskatoon and Yellowknife, Canada, and Toolik Lake, Alaska. We constrained the uncalibrated model with the WSE at the time of the first ABoVE flight, and quantified the model's ability to predict WSE and ΔWSE during the time of the second flight. Finally, we evaluated the sensitivity of the VIC-lakes model and compared the three permafrost conditions. Our results quantify the sensitivity of surface water to permafrost state across the target sites. Furthermore, our evaluation of the lake modeling framework contributes to the modeling and mapping framework for lake and reservoir storage change evaluation globally as part of the SWOT mission, planned for launch in 2021.

  7. Satellite monitoring of dramatic changes at Hawai'i's only alpine lake: Lake Waiau on Mauna Kea volcano

    USGS Publications Warehouse

    Patrick, Matthew R.; Kauahikaua, James P.

    2015-01-01

    Lake Waiau is a small, typically 100-meter-long lake, located near the summit of Mauna Kea volcano, on the Island of Hawaiʻi. It is Hawaiʻi’s only alpine lake and is considered sacred in Hawaiian cultural tradition. Over the past few years, the lake has diminished in size, and, by October 2013, surface water had almost completely disappeared from the lake. In this study, we use high-resolution satellite images and aerial photographs to document recent changes at the lake. Based on our reconstructions covering the past 200 years, the historical lake surface area has typically ranged from 5,000 to 7,000 square meters, but in 2010 a dramatic plunge in lake area ensued. The lake area rebounded significantly in early 2014, following heavy winter storms. This near disappearance of the lake, judging from analysis of visitor photographs and field reports, appears to be highly unusual, if not unprecedented, in the historical record. The unusually low water levels in the lake are consistent with a recent severe drought in Hawaiʻi.

  8. Changes in the area of inland lakes in arid regions of central Asia during the past 30 years.

    PubMed

    Bai, Jie; Chen, Xi; Li, Junli; Yang, Liao; Fang, Hui

    2011-07-01

    Inland lakes are major surface water resource in arid regions of Central Asia. The area changes in these lakes have been proved to be the results of regional climate changes and recent human activities. This study aimed at investigating the area variations of the nine major lakes in Central Asia over the last 30 years. Firstly, multi-temporal Landsat imagery in 1975, 1990, 1999, and 2007 were used to delineate lake extents automatically based on Normalized Difference Water Index (NDWI) threshold segmentation, then lake area variations were detailed in three decades and the mechanism of these changes was analyzed with meteorological data and hydrological data. The results indicated that the total surface areas of these nine lakes had decreased from 91,402.06 km(2) to 46,049.23 km(2) during 1975-2007, accounting for 49.62% of their original area of 1975. Tail-end lakes in flat areas had shrunk dramatically as they were induced by both climate changes and human impacts, while alpine lakes remained relatively stable due to the small precipitation variations. With different water usage of river outlets, the variations of open lakes were more flexible than those of other two types. According to comprehensive analyses, different types of inland lakes presented different trends of area changes under the background of global warming effects in Central Asia, which showed that the increased human activities had broken the balance of water cycles in this region.

  9. Remote Sensing Analysis of Volume in Taihu Lake: Application for Icesat/hydroweb and Landsat Data

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Li, Y.; Lu, Y.; Yue, H.

    2018-04-01

    In order to evaluate the fluctuation of Taihui Lake, ICESat/Hydroweb and Landsat data recorded from 1975 to 2015 were used to examine changes in lake level and area, derived from Normalized Difference Water Index (NDWI) and Modified Normalized Difference Water Index (MNDWI), which are combined to indirectly evaluate water volume variations and water balance of Taihu Lake. The results show that the time series of lake area and volume variations of Taihu Lake exhibit a gradually increasing trend from 1975 to 2015 and the value rose from 2320.07 km2 and -0.0470 km3, respectively in 1975 to 2341.06 km2 and 0.2759 km3, respectively in 2015. The water level of Taihu Lake demonstrates a fluctuating trend during 1975-2015 and the value changed from 0.9826 m in 1975 to 1.1359 m in 2015. There was a moderate correlation for Taihu Lake (R2 ≈ 0.65) between water level and surface area. The water volume changes was in very good agreement for lake level changes and surface area variations (R2 > 0.85). Combining with lake level and area changes, water balance of Taihu Lake was acquired and it shows a positive water budgets of 0.0092 km3 during past 40 years.

  10. Coastal groundwater/surface-water interactions: a Great Lakes case study

    USGS Publications Warehouse

    Neff, Brian P.; Haack, Sheridan K.; Rosenberry, Donald O.; Savino, Jacqueline F.; Lundstrom, Scott C.

    2006-01-01

    Key similarities exist between marine and Great Lakes coastal environments. Water and nutrient fluxes across lakebeds in the Great Lakes are influenced by seiche and wind set-up and set-down, analogous to tidal influence in marine settings. Groundwater/surface-water interactions also commonly involve a saline-fresh water interface, although in the Great-Lakes cases, it is groundwater that is commonly saline and surface water that is fresh. Evapotranspiration also affects nearshore hydrology in both settings. Interactions between groundwater and surface water have recently been identified as an important component of ecological processes in the Great Lakes. Water withdrawals and the reversal of the groundwater/surface water seepage gradient are also common to many coastal areas around the Great Lakes. As compared to surface water, regional groundwater that discharges to western Lake Erie from Michigan is highly mineralized. Studies conducted by the U.S. Geological Survey at Erie State Game Area in southeastern Michigan, describe groundwater flow dynamics and chemistry, shallow lake-water chemistry, and fish and invertebrate communities. Results presented here provide an overview of recent progress of ongoing interdisciplinary studies of Great Lakes nearshore systems and describe a conceptual model that identifies relations among geologic, hydrologic, chemical, and biological processes in the coastal habitats of Lake Erie. This conceptual model is based on analysis of hydraulic head in piezometers at the study site and chemical analysis of deep and shallow coastal groundwater.

  11. Bathymetric contour map, surface area and capacity table, and bathymetric difference map for Clearwater Lake near Piedmont, Missouri, 2017

    USGS Publications Warehouse

    Richards, Joseph M.; Huizinga, Richard J.

    2018-06-19

    Clearwater Lake, on the Black River near Piedmont in Reynolds County, Missouri, was constructed in 1948 and is operated by the U.S. Army Corps of Engineers for flood-risk reduction, recreation, and fish and wildlife habitat. The lake area is about 1,800 acres with about 34 miles of shoreline at the conservation pool elevation of 498 feet. Since the completion of the lake in 1948, sedimentation likely has caused the storage capacity of the lake to decrease gradually. The loss of storage capacity can decrease the effectiveness of the lake to mitigate flooding, and excessive sediment accumulation also can reduce aquatic habitat in some areas of the lake. Many lakes operated by the U.S. Army Corps of Engineers have periodic bathymetric and sediment surveys to monitor the status of the lake. The U.S. Geological Survey completed one such survey of Clearwater Lake in 2008 during a period of high lake level using bathymetric surveying equipment consisting of a multibeam echosounder, a singlebeam echosounder, 1/3 arc-second National Elevation Dataset data (used outside the multibeam echosounder survey extent), and the waterline derived from 2008 aerial light detection and ranging (lidar) data. In May 2017, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, surveyed the bathymetry of Clearwater Lake to prepare an updated bathymetric map and a surface area and capacity table. The 2008 survey was contrasted with the 2017 survey to document the changes in the bathymetric surface of the lake.

  12. Bisphenol analogues in surface water and sediment from the shallow Chinese freshwater lakes: Occurrence, distribution, source apportionment, and ecological and human health risk.

    PubMed

    Yan, Zhengyu; Liu, Yanhua; Yan, Kun; Wu, Shengmin; Han, Zhihua; Guo, Ruixin; Chen, Meihong; Yang, Qiulian; Zhang, Shenghu; Chen, Jianqiu

    2017-10-01

    Compared to Bisphenol A (BPA), current knowledge on the spatial distribution, potential sources and environmental risk assessment of other bisphenol analogues (BPs) remains limited. The occurrence, distribution and sources of seven BPs were investigated in the surface water and sediment from Taihu Lake and Luoma Lake, which are the Chinese shallow freshwater lakes. Because there are many industries and living areas around Taihu Lake, the total concentrations of ∑BPs were much higher than that in Luoma Lake, which is away from the industry-intensive areas. For the two lakes, BPA was still the dominant BPs in both surface water and sediment, followed by BPF and BPS. The spatial distribution and principal component analysis showed that BPs in Luoma Lake was relatively homogeneous and the potential sources were relatively simple than that in Taihu Lake. The spatial distribution of BPs in sediment of Taihu Lake indicated that ∑BPs positively correlated with the TOC content. For both Taihu Lake and Luoma Lake, the risk assessment at the sampling sites showed that no high risk in surface water and sediment (RQ t  < 1.0, and EEQ t  < 1.0 ng E 2 /L). Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Surface area changes of Himalayan ponds as a proxy of hydrological climate-driven fluctuations

    NASA Astrophysics Data System (ADS)

    Salerno, Franco; Thakuri, Sudeep; Guyennon, Nicolas; Viviano, Gaetano; Tartari, Gianni

    2016-04-01

    The meteorological measurements at high-elevations of the Himalayan range are scarce due to the harsh conditions of these environments which limit the suitable maintenance of weather stations. As a consequence, the meager knowledge on how the climate is changed in the last decades at Himalayan high-elevations sets a serious limit upon the interpretation of relationships between causes and recent observed effects on the cryosphere. Although the glaciers masses reduction in Himalaya is currently sufficiently well described, how changes in climate drivers (precipitation and temperature) have influenced the melting and shrinkage processes are less clear. Consequently, the uncertainty related to the recent past amplifies when future forecasts are done, both for climate and impacts. In this context, a substantial body of research has already demonstrated the high sensitivity of lakes and ponds to climate. Some climate-related signals are highly visible and easily measurable in lakes. For example, climate-driven fluctuations in lake surface area have been observed in many remote sites. On interior Tibetan Plateau the lake growth since the late 1990s is mainly attributed to increased regional precipitation and weakened evaporation. Differently, other authors attribute at the observed increases of lake surfaces at the enhanced glacier melting. In our opinion these divergences found in literature are due to the type of glacial lakes considered in the study and in particular their relationship with glaciers. In general, in Himalaya three types of glacial lakes can be distinguished: (i) lakes that are not directly connected with glaciers, but that may have a glacier located in their basin (unconnected glacial lakes); (ii) supraglacial lakes, which develop on the surface of the glacier downstream; or (iii) proglacial lakes, which are moraine-dammed lakes that are in contact with the glacier front. Some of these lakes store large quantities of water and are susceptible to GLOFs (glacial lake outburst floods). Whereas the lake surface areas variations of these lakes are strictly connected with the ablation processes and glacier velocities, variation related to unconnected glacial lakes are possibly influenced by only the resulting glacier melting. This difference with the other lake types makes unconnected glacial lakes potential indicators of changes of the main water balance components of high-elevated lake basins as: precipitation, glacier melting, and evapotranspiration. An evaluable opportunity for a fine-scale investigation on climate-driven fluctuations in lake surface area is particularly evident on the south slopes of Mt. Everest (Nepal), which is one of the most heavily glacierized parts of Himalaya, at same time, the region that is most characterized by glacial lakes in the overall Hindu-Kush-Himalaya range, and in which a twenty years series of temperature and precipitation has been recently reconstructed for high-elevations (5000 m a.s.l.). This contribution examines the surface area changes of unconnected glacial ponds, i.e., that are not directly connected with glaciers, on the south side of Mt. Everest in the last fifty years as part of an effort to evaluate if they can be considered potential indicators useful to detect how the climate is changed at high-elevations of the Himalayan range.

  14. Remote sensing assessment of oil lakes and oil-polluted surfaces at the Greater Burgan oil field, Kuwait

    NASA Astrophysics Data System (ADS)

    Kwarteng, Andy Yaw

    A heinous catastrophe imposed on Kuwait's desert environment during the 1990 to 1991 Arabian Gulf War was the formation of oil lakes and oil-contaminated surfaces. Presently, the affected areas consist of oil lakes, thick light and disintegrated tarmats, black soil and vegetation. In this study, Landsat TM, Spot, colour aerial photographs and IRS-1D digital image data acquired between 1989 and 1998 were used to monitor the spatial and temporal changes of the oil lakes and polluted surfaces at the Greater Burgan oil field. The use of multisensor datasets provided the opportunity to observe the polluted areas in different wavelengths, look angles and resolutions. The images were digitally enhanced to optimize the visual outlook and improve the information content. The data documented the gradual disappearance of smaller oil lakes and soot/black soil from the surface with time. Even though some of the contaminants were obscured by sand and vegetation and not readily observed on the surface or from satellite images, the harmful chemicals still remain in the soil. Some of the contaminated areas displayed a remarkable ability to support vegetation growth during the higher than average rainfall that occurred between 1992 to 1998. The total area of oil lakes calculated from an IRS-1D panchromatic image acquired on 16 February 1998, using supervised classification applied separately to different parts, was 24.13 km 2.

  15. Earth resources evaluation for New Mexico by LANDSAT-2

    NASA Technical Reports Server (NTRS)

    Vonderlinden, K. (Principal Investigator); Feldman, S. C.; Inglis, M. H.; Tabet, D.; Kottlowski, F. E.

    1975-01-01

    The author has identified the following significant results. A cost effective technique is considered for measuring and monitoring surface area fluctuations in lake size in southeastern New Mexico over a two year period. The lakes are shallow, and therefore a small volume increase results in a noticeable increase in surface area on the LANDSAT imagery. Lake sizes are measured on an I(2)S Digicol viewer. Water from potash mining operations is being pumped into some of these lakes and the input volume is documented. Using water input and surface contour as well as direct lake level measurements as ground truth as well as the LANDSAT images, calculations may be possible regarding how much additional industrial water can be added to these lakes without the occurrence of saline see page into the major river system.

  16. Is there a pattern to oxbow lake geomorphic evolution?

    NASA Astrophysics Data System (ADS)

    Dieras, P.; Constantine, J. A.

    2012-04-01

    Oxbow lakes are located along the floodplain corridor and created after meander cutoff. They are of high ecological value as they provide relatively calm wetlands which are regularly supplied with nutrients during floods. The persistence of oxbow lakes has been observed to vary from decades to several hundreds of years but little is known about the controls on their longevity. This study aims to ascertain if there is a common pattern in the water decrease of oxbow lakes and to define the controls on the lakes' longevity. The longevity of 37 oxbow lakes from 7 rivers from different parts of the world has been studied. The Towy River (Wales), the Ain River (France) and the Sacramento River (CA, USA) are largely dominated by oxbow lakes created after chute cutoff which is the incision of a chute across the floodplain; whereas the Mississippi River (MS, USA), the Kansas River (KS, USA), the Red River (MN, USA) and the Otter Tail River (MN, USA) show a large number of neck cutoffs which occur when two meanders migrate into one another. The water surface area decrease has been measured for all the sites using aerial photographs. Results revealed that the longevity of oxbow lakes is significantly affected by the type of cutoff. The lakes formed by chute cutoff lose very rapidly most of the water surface area of the initial channel as it is reduce by >80% within the first 10 to 30 years following cutoff for most sites. The water surface area of chute cutoff shows a logarithmic decrease with a fast decrease rate following cutoff, followed by a much slower loss of water surface area. The change in water decrease rate appears to be related to the moment of obstruction of the former channel entrance by sediment aggradation. In contrast, lakes formed by neck cutoff persist for much longer in the landscape and lose 40 to 60% within the first decades but then they maintain this water surface area for longer than a century. The cutoff process is therefore the main control on the persistence of oxbow lakes and has important impact on the habitats on the floodplain corridor.

  17. Acidification of lake water due to drought

    NASA Astrophysics Data System (ADS)

    Mosley, L. M.; Zammit, B.; Jolley, A. M.; Barnett, L.

    2014-04-01

    Droughts are predicted to increase in many river systems due to increased demand on water resources and climate variability. A severe drought in the Murray-Darling Basin of Australia from 2007 to 2009 resulted in unprecedented declines in water levels in the Lower Lakes (Ramsar-listed ecosystem of international importance) at the end of the river system. The receding water exposed large areas (>200 km2) of sediments on the lake margins. The pyrite (FeS2) in these sediments oxidised and generated high concentrations of acidity. Upon rewetting of the exposed sediments, by rainfall or lake refill, surface water acidification (pH 2-3) occurred in several locations (total area of 21.7 km2). High concentrations of dissolved metals (Al, As, Co, Cr, Cu, Fe, Mn, Ni, Zn), which greatly exceeded aquatic ecosystem protection guidelines, were mobilised in the acidic conditions. In many areas neutralisation of the surface water acidity occurred naturally during lake refill, but aerial limestone dosing was required in two areas to assist in restoring alkalinity. However acidity persists in the submerged lake sediment and groundwater several years after surface water neutralisation. The surface water acidification proved costly to manage and improved water management in the Murray-Darling Basin is required to prevent similar events occurring in the future.

  18. Lake surface area variation and its responses to climatic change in Yamzhog Yumco Basin, South Tibet during 1970-2010

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Tian, Y.; Sun, R.

    2015-12-01

    The research on lake extraction from multi-source and multi-temporal satellite images and the lake size variation can provide reliable method and indispensable information to deepen the understanding about alpine lake changes with the accelerating warming. With field survey experience in the Yamzhog Yumco Basin, South Tibet, the outlines of five lakes (i.e., Yamzhog Yumco, Chen Co, Kongmu Co, Bajiu Co and Puma Yumco) were delineated by the adoption of 42 scenes of satellite images from Landsat, CBERS and HJ from 1970 to 2010, basing on which the responses of alpine lakes to climate change at different timescales were explored. The results are summarized as follows. (1) The seasonal fluctuation of lake surface area was similar with different trend for the five alpine lakes. As for the last 41 years, the annual variation of lake surface area exhibited two kinds of patterns for the five alpine lakes. And the Yamzhog Yumco declined by 9.41%, while the rest four lakes expanded. (2) The responses of alpine lakes to climate change rely on different timescale and water replenishment types. On the one hand, the precipitation change was the predominant driving forces for the seasonal fluctuation and variation trend of lake size, and the rising temperature accounted for the inter-annual lake surface variation. On the other hand, the two kinds of alpine lakes behaviors were well correspondent with the warming temperature over the Qinghai-Tibetan Plateau. The lakes supplied mainly by precipitation shrunk as a result of increased evaporation, and lakes supplied mainly by glacier and snow meltwater, however, expanded because of the remarkable glacier recession. (3) The quantification of hydrological components would hopefully be improved, according to uncertainties analysis, with the adoption of microwave satellite images and higher resolution ones to disclose the interaction mechanism among climate, glacier, and lake in alpine regions.

  19. Prediction of lake depth across a 17-state region in the United States

    USGS Publications Warehouse

    Oliver, Samantha K.; Soranno, Patricia A.; Fergus, C. Emi; Wagner, Tyler; Winslow, Luke A.; Scott, Caren E.; Webster, Katherine E.; Downing, John A.; Stanley, Emily H.

    2016-01-01

    Lake depth is an important characteristic for understanding many lake processes, yet it is unknown for the vast majority of lakes globally. Our objective was to develop a model that predicts lake depth using map-derived metrics of lake and terrestrial geomorphic features. Building on previous models that use local topography to predict lake depth, we hypothesized that regional differences in topography, lake shape, or sedimentation processes could lead to region-specific relationships between lake depth and the mapped features. We therefore used a mixed modeling approach that included region-specific model parameters. We built models using lake and map data from LAGOS, which includes 8164 lakes with maximum depth (Zmax) observations. The model was used to predict depth for all lakes ≥4 ha (n = 42 443) in the study extent. Lake surface area and maximum slope in a 100 m buffer were the best predictors of Zmax. Interactions between surface area and topography occurred at both the local and regional scale; surface area had a larger effect in steep terrain, so large lakes embedded in steep terrain were much deeper than those in flat terrain. Despite a large sample size and inclusion of regional variability, model performance (R2 = 0.29, RMSE = 7.1 m) was similar to other published models. The relative error varied by region, however, highlighting the importance of taking a regional approach to lake depth modeling. Additionally, we provide the largest known collection of observed and predicted lake depth values in the United States.

  20. Quality of surface-water supplies in the Triangle area of North Carolina, water year 2008

    USGS Publications Warehouse

    Giorgino, M.J.; Rasmussen, R.B.; Pfeifle, C.A.

    2012-01-01

    •Five lakes had chlorophyll a concentrations in excess of 40 micrograms per liter at least once during 2008, including Little River Reservoir, Falls Lake, Lake Benson, University Lake, and Jordan Lake.

  1. On the methane paradox: Transport from shallow water zones rather than in situ methanogenesis is the major source of CH4 in the open surface water of lakes

    NASA Astrophysics Data System (ADS)

    Encinas Fernández, Jorge; Peeters, Frank; Hofmann, Hilmar

    2016-10-01

    Estimates of global methane (CH4) emissions from lakes and the contributions of different pathways are currently under debate. In situ methanogenesis linked to algae growth was recently suggested to be the major source of CH4 fluxes from aquatic systems. However, based on our very large data set on CH4 distributions within lakes, we demonstrate here that methane-enriched water from shallow water zones is the most likely source of the basin-wide mean CH4 concentrations in the surface water of lakes. Consistently, the mean surface CH4 concentrations are significantly correlated with the ratio between the surface area of the shallow water zone and the entire lake, fA,s/t, but not with the total surface area. The categorization of CH4 fluxes according to fA,s/t may therefore improve global estimates of CH4 emissions from lakes. Furthermore, CH4 concentrations increase substantially with water temperature, indicating that seasonally resolved data are required to accurately estimate annual CH4 emissions.

  2. A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009

    PubMed Central

    Sharma, Sapna; Gray, Derek K; Read, Jordan S; O’Reilly, Catherine M; Schneider, Philipp; Qudrat, Anam; Gries, Corinna; Stefanoff, Samantha; Hampton, Stephanie E; Hook, Simon; Lenters, John D; Livingstone, David M; McIntyre, Peter B; Adrian, Rita; Allan, Mathew G; Anneville, Orlane; Arvola, Lauri; Austin, Jay; Bailey, John; Baron, Jill S; Brookes, Justin; Chen, Yuwei; Daly, Robert; Dokulil, Martin; Dong, Bo; Ewing, Kye; de Eyto, Elvira; Hamilton, David; Havens, Karl; Haydon, Shane; Hetzenauer, Harald; Heneberry, Jocelyne; Hetherington, Amy L; Higgins, Scott N; Hixson, Eric; Izmest’eva, Lyubov R; Jones, Benjamin M; Kangur, Külli; Kasprzak, Peter; Köster, Olivier; Kraemer, Benjamin M; Kumagai, Michio; Kuusisto, Esko; Leshkevich, George; May, Linda; MacIntyre, Sally; Müller-Navarra, Dörthe; Naumenko, Mikhail; Noges, Peeter; Noges, Tiina; Niederhauser, Pius; North, Ryan P; Paterson, Andrew M; Plisnier, Pierre-Denis; Rigosi, Anna; Rimmer, Alon; Rogora, Michela; Rudstam, Lars; Rusak, James A; Salmaso, Nico; Samal, Nihar R; Schindler, Daniel E; Schladow, Geoffrey; Schmidt, Silke R; Schultz, Tracey; Silow, Eugene A; Straile, Dietmar; Teubner, Katrin; Verburg, Piet; Voutilainen, Ari; Watkinson, Andrew; Weyhenmeyer, Gesa A; Williamson, Craig E; Woo, Kara H

    2015-01-01

    Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues. PMID:25977814

  3. A global database of lake surface temperatures collected by in situ and satellite methods from 1985-2009.

    PubMed

    Sharma, Sapna; Gray, Derek K; Read, Jordan S; O'Reilly, Catherine M; Schneider, Philipp; Qudrat, Anam; Gries, Corinna; Stefanoff, Samantha; Hampton, Stephanie E; Hook, Simon; Lenters, John D; Livingstone, David M; McIntyre, Peter B; Adrian, Rita; Allan, Mathew G; Anneville, Orlane; Arvola, Lauri; Austin, Jay; Bailey, John; Baron, Jill S; Brookes, Justin; Chen, Yuwei; Daly, Robert; Dokulil, Martin; Dong, Bo; Ewing, Kye; de Eyto, Elvira; Hamilton, David; Havens, Karl; Haydon, Shane; Hetzenauer, Harald; Heneberry, Jocelyne; Hetherington, Amy L; Higgins, Scott N; Hixson, Eric; Izmest'eva, Lyubov R; Jones, Benjamin M; Kangur, Külli; Kasprzak, Peter; Köster, Olivier; Kraemer, Benjamin M; Kumagai, Michio; Kuusisto, Esko; Leshkevich, George; May, Linda; MacIntyre, Sally; Müller-Navarra, Dörthe; Naumenko, Mikhail; Noges, Peeter; Noges, Tiina; Niederhauser, Pius; North, Ryan P; Paterson, Andrew M; Plisnier, Pierre-Denis; Rigosi, Anna; Rimmer, Alon; Rogora, Michela; Rudstam, Lars; Rusak, James A; Salmaso, Nico; Samal, Nihar R; Schindler, Daniel E; Schladow, Geoffrey; Schmidt, Silke R; Schultz, Tracey; Silow, Eugene A; Straile, Dietmar; Teubner, Katrin; Verburg, Piet; Voutilainen, Ari; Watkinson, Andrew; Weyhenmeyer, Gesa A; Williamson, Craig E; Woo, Kara H

    2015-01-01

    Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985-2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues.

  4. A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009

    USGS Publications Warehouse

    Sharma, Sapna; Gray, Derek; Read, Jordan S.; O'Reilly, Catherine; Schneider, Philipp; Qudrat, Anam; Gries, Corinna; Stefanoff, Samantha; Hampton, Stephanie; Hook, Simon; Lenters, John; Livingstone, David M.; McIntyre, Peter B.; Adrian, Rita; Allan, Mathew; Anneville, Orlane; Arvola, Lauri; Austin, Jay; Bailey, John E.; Baron, Jill S.; Brookes, Justin D; Chen, Yuwei; Daly, Robert; Ewing, Kye; de Eyto, Elvira; Dokulil, Martin; Hamilton, David B.; Havens, Karl; Haydon, Shane; Hetzenaeur, Harald; Heneberry, Jocelyn; Hetherington, Amy; Higgins, Scott; Hixson, Eric; Izmest'eva, Lyubov; Jones, Benjamin M.; Kangur, Kulli; Kasprzak, Peter; Kraemer, Benjamin; Kumagai, Michio; Kuusisto, Esko; Leshkevich, George; May, Linda; MacIntyre, Sally; Dörthe Müller-Navarra,; Naumenko, Mikhail; Noges, Peeter; Noges, Tiina; Pius Niederhauser,; North, Ryan P.; Andrew Paterson,; Plisnier, Pierre-Denis; Rigosi, Anna; Rimmer, Alon; Rogora, Michela; Rudstam, Lars G.; Rusak, James A.; Salmaso, Nico; Samal, Nihar R.; Daniel E. Schindler,; Geoffrey Schladow,; Schmidt, Silke R.; Tracey Schultz,; Silow, Eugene A.; Straile, Dietmar; Teubner, Katrin; Verburg, Piet; Voutilainen, Ari; Watkinson, Andrew; Weyhenmeyer, Gesa A.; Craig E. Williamson,; Kara H. Woo,

    2015-01-01

    Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues.

  5. The regional abundance and size distribution of lakes and reservoirs in the United States and implication for estimates of global lake extent

    USGS Publications Warehouse

    McDonald, Cory P.; Rover, Jennifer; Stets, Edward G.; Striegl, Robert G.

    2012-01-01

    We analyzed complete geospatial data for the 3.5 million lakes and reservoirs larger than 0.001 km2, with a combined surface area of 131,000 km2, in the contiguous United States (excluding the Laurentian Great Lakes) and identified their regional distribution characteristics. For Alaska, we also analyzed (1) incomplete data that suggest that the state contains 1–2.5 million lakes larger than 0.001 km2 covering over 50,000 km2 and (2) localized high-resolution (5 m) data that suggest that the number of very small water bodies (< 0.001 km2) may be comparable with the number of lakes > 0.001 km2 in some areas. The Pareto distribution cannot accurately describe the lake abundance-size relationship across the entire size spectrum, and extrapolation of this density function to small size classes has likely resulted in the overestimation of the number of small lakes in the world. While small water bodies dominate in terms of numbers, they are not numerous enough to dominate in terms of surface area, as has been previously suggested. Extending our results to the global scale suggests that there are on the order of 64 million water bodies larger than 0.001 km2 in the world, with a total surface area of approximately 3.8 million km2.

  6. Diel Surface Temperature Range Scales with Lake Size

    PubMed Central

    Woolway, R. Iestyn; Jones, Ian D.; Maberly, Stephen C.; French, Jon R.; Livingstone, David M.; Monteith, Donald T.; Simpson, Gavin L.; Thackeray, Stephen J.; Andersen, Mikkel R.; Battarbee, Richard W.; DeGasperi, Curtis L.; Evans, Christopher D.; de Eyto, Elvira; Feuchtmayr, Heidrun; Hamilton, David P.; Kernan, Martin; Krokowski, Jan; Rimmer, Alon; Rose, Kevin C.; Rusak, James A.; Ryves, David B.; Scott, Daniel R.; Shilland, Ewan M.; Smyth, Robyn L.; Staehr, Peter A.; Thomas, Rhian; Waldron, Susan; Weyhenmeyer, Gesa A.

    2016-01-01

    Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer diel ranges in their near-surface temperatures of between 4 and 7°C. Large diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored. PMID:27023200

  7. Impact of war, precipitation, and water management on quantity of water resources in the Tigris/Euphrates area

    NASA Astrophysics Data System (ADS)

    Hasan, Mejs; Moody, Aaron

    2017-04-01

    The fast-paced conflicts in the Middle East have the potential to disrupt management and supply of water resources in the region. In this research, we use the normalized difference water index (NDWI) in order to monitor changes in the extent of various water bodies over the time span of the Landsat 4, 5, 7, and 8 satellites (1984-present). We focused on Mosul and Haditha dam lakes, located on the Tigris and Euphrates Rivers, respectively, each of which has experienced changes in sovereignty over the last few years of conflict. We established two areas, one land and one water, on each image, plotted the distributions of all NDWI values for each area, and used the number of standard deviations between the two distributions in order to set a dynamic NDWI threshold for each image. Using this threshold, we determined water pixels and lake surface area, and computed daily percent change in lake extent between images. Furthermore, we took account of explanatory water resource variables, such as upstream dam management (via surface extent of upstream Turkish dams), precipitation (via globally-compiled databases), evaporation (based on surface area decreases during non-rainy months), and irrigation withdrawals (based on MODIS Enhanced Vegetation Indices). We used these explanatory variables in order to build a general model of expected dam lake surface extent, and we looked to see if anomalies from expected surface area corresponded with periods of conflict. We found that the recent years of conflict do not appear to have had as much impact on the Mosul and Haditha dam lakes as did the conflicts related to the earlier Gulf Wars. The dam lakes have recorded an overall decrease in surface area simultaneous to increases of upstream dams. A strong seasonal signal driven by springtime Turkish snowmelt and summer evaporation is also evident.

  8. Hidden Outgassing Dynamics at Kilauea (Hawaii) Lava Lake

    NASA Astrophysics Data System (ADS)

    Del Bello, E.; Taddeucci, J.; Orr, T. R.; Houghton, B. F.; Scarlato, P.; Patrick, M. R.

    2014-12-01

    Lava lakes offer unique opportunities for understanding how magmatic volatiles physically escape from low-viscosity, vesicular magma in open-vent conditions, a process often referred to as magma outgassing. Large-scale lava convection movements and meter-scale bubble explosions, sometimes triggered by rock falls, are acknowledged outgassing processes but may not be the only ones. In 2013 we used high-frequency (50-500 Hz) thermal and visible imaging to investigate the short-timescale dynamics of the currently active Halema`uma`u lava lake. At that time, besides the dominant release of large bubbles, three types of peculiar outgassing features were observed on the lava lake surface. The first, diffusely observed throughout the observation experiment, consisted of prolonged (up to seconds) gas venting from 'spot vents'. These vents appeared to open and close without the ejection of material or bubble bursting, and were the site of hot gas emission. Spot vents were located both between and inside cooling plates, and followed the general circulation pattern together with the rest of the lava lake surface. The second feature, observed only once, consisted of the transient wobbling of the whole lava lake surface. This wobbling, with a wavelength of meters to tens of meters, was not related to any external trigger, and dampened soon without apparent consequences on the other lake dynamics. Finally, we observed large (meters) doming areas of the lake surface randomly fluctuating over seconds to minutes. These areas were either stationary or moved independently of the general lake surface circulation, and usually were not affected by other lake surface features (e.g., cooling plate boundaries). These three features, though trivial for the overall lake outgassing, testify that the lava lake has a complex shallow subsurface architecture, in which permeable channels and gas pockets act independently of the more common bubble bursts.

  9. Aspects of the bottom sediment of Lake Nakaumi and Honjo area ~ featuring with organic matter and the Sulfides ~

    NASA Astrophysics Data System (ADS)

    Shinohara, R.

    2015-12-01

    Lake Nakaumi is a brackish water located at southwest Japan. Seawater from the Sea of Japan inflows through Sakai-strait, and river water flows through the Oohashi River into this lake. Lake Nakaumi is characterized with hypoxic and/or anoxic condition of bottom water derived with the distinct stratification of salinity in summer season. In this lake, a public project had been carried out for land reclamation since 1963. Honjo Area located to the north part of Lake Nakaumi, was semi-separated from Lake Nakaumi by reclamation dikes constructed for this project at 1981. However, this public project was aborted with the change of social conditions. To the effective utilization of the area, the partial removal of dike was carried out. Seawater from Sakai-strait flows directly into Honjo Area again. Environmental change of the lake is expected by this inflow of the seawater in Lake Nakaumi and Honjo Area after this restoration. It is well known that the surface sediment reflects the environment of lake bottom. The organic matter and the sulfides in sediment are good indicators of sedimentation environment. In this study, we analyzed them by several methods and grasped the bottom environment of both areas after the removal of dikes. We examined the impact of the restoration to both areas by comparing the observations with the past data. Surface sediment samples in Lake Nakaumi and Honjo Area were obtained at 77 and 40 stations, respectively. We collected surface sediment (about 1cm) were for each station, and analyzed total organic carbon (TOC) and total nitrogen (TN) as organic matter, and hydrogen sulfide (H2S) in pore water, total sulfide (TS) and acid volatile sulfide (AVS) as sulfides. TOC contents of Lake Nakaumi and Honjo Area range within 0.0-5.1% and 0.2-4.9%, respectively. TN contents range within 0.0-0.6 % and 0.1-0.6 %. TS contents range within 0.1-2.6% and 0.0-2.0 %. H2S contents range within 0.3-119.0 ppm and 0.5-140.4 ppm. AVS contents range within 0.0-9.4 mg/g and 0.0-5.1 mg/g. In comparison between Lake Nakaumi and Honjo Area, the apparent difference was not detected in H2S and AVS contents, but there was a broad distinction in TS contents. This results shows that Honjo Area deposits significantly little FeS2 contents. It was thought that a difference in the form of sulfide showed a characteristic of Honjo Area.

  10. Monitoring of Water-Level Fluctuation of Lake Nasser Using Altimetry Satellite Data

    NASA Astrophysics Data System (ADS)

    El-Shirbeny, Mohammed A.; Abutaleb, Khaled A.

    2018-05-01

    Apart from the Renaissance Dam and other constructed dams on the River Nile tributaries, Egypt is classified globally as a state of scarce water. Egypt's water resources are very limited and do not contribute a significant amount to its water share except the River Nile (55.5 billion m3/year). While the number of population increases every year, putting more stress on these limited resources. This study aims to use remote-sensing data to assess the change in surface area and water-level variation in Lake Nasser using remote-sensing data from Landsat-8 and altimetry data. In addition, it investigates the use of thermal data from Landsat-8 to calculate water loss based on evaporation from Lake Nasser. The eight Landsat-8 satellite images were used to study the change in surface area of Lake Nasser representing winter (January) and summer (June/July) seasons in two consecutive years (2015 and 2016). Time series analyses for 10-day temporal resolution water-level data from Jason-2/OSTM and Jason-3 altimetry was carried out to investigate water-level trends over the long term (1993 and 2016) and short term (2015-2016) in correspondence with the change of the surface area. Results indicated a shrink in the lake surface area in 2016 of approximately 14% compared to the 2015 area. In addition, the evaporation rate in the lake is very high causing a loss of approximately 20% of the total water share from the river Nile.

  11. Characterizing the fabric of the urban environment: A case study of Salt Lake City, Utah

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Akbari, Hashem; Rose, L. Shea

    2001-02-28

    Urban fabric data are needed in order to estimate the impact of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on the meteorology and air quality of a city, and to design effective implementation programs. In this report, we discuss the result of a semi-automatic Monte-Carlo statistical approach used to develop data on surface-type distribution and city-fabric makeup (percentage of various surface-types) using aerial color orthophotography. The digital aerial photographs for Salt Lake City covered a total of about 34 km2 (13 mi2). At 0.50-m resolution, there were approximately 1.4 x 108 pixels of data. Four majormore » land-use types were examined: (1) commercial, (2) industrial, (3) educational, and (4) residential. On average, for the areas studied, vegetation covers about 46 percent of the area (ranging 44-51 percent), roofs cover about 21 percent (ranging 15-24 percent), and paved surfaces about 26 percent (ranging 21-28 percent). For the most part, trees shade streets, parking lots, grass, and sidewalks. In most non-residential areas, paved surfaces cover 46-66 percent of the area. In residential areas, on average, paved surfaces cover about 32 percent of the area. Land-use/land-cover (LU/LC) data from the United States Geological Survey were used to extrapolate these results from neighborhood scales to metropolitan Salt Lake City. In an area of roughly 560 km2, defining most of metropolitan Salt Lake City, over 60 percent is residential. The total roof area is about 110 km2, and the total paved surface area (roads, parking areas, sidewalks) covers about 170 km2. The total vegetated area covers about 230 km2.« less

  12. Sources of fatty acids in Lake Michigan surface microlayers and subsurface waters

    NASA Astrophysics Data System (ADS)

    Meyers, Philip A.; Owen, Robert M.

    1980-11-01

    Fatty acid and organic carbon contents have been measured in the particulate and dissolved phases of surface microlayer and subsurface water samples collected from Lake Michigan. Concentrations are highest close to fluvial sources and lowest in offshore areas, yet surface/subsurface fractionation is lowest near river mouths and highest in open lake locations. These gradients plus accompanying fatty acid compositional changes indicate that river-borne organic materials are important constituents of coastal Lake Michigan microlayers and that sinking and turbulent resuspension of particulates affect surface film characteristics. Lake neuston and plankton contribute organic components which partially replace potamic materials removed by sinking.

  13. Recent glacier retreat and lake formation in the Querecocha watershed, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    López Moreno, J.; Valero-Garces, B.; Revuelto, J.; Azorín-Molina, C.; Bazo, J.; Cochachin, A.; Fontaneda, S.; Mark, B. G.

    2013-12-01

    In the Andes, and specifically in the Peruvian mountains a marked decrease of the glaciated area has occurred since the end of the Little Ice Age, and it has been accelerated since the last decades of the 20th century. As a result of the glacier retreat new pro-glaciar lakes are originated, and often the area and volume of existing ones increases. The study of these newly-formed lakes and their recent evolution may provide a better understanding of the hydrological and geomorphological evolution of deglaciated areas, and a better evaluation of the risk of glacial lakes outburst floods (GLOFS). In this work, we use 26 annual Landsat Thematic Mapper images from 1975 to 2010 to determine changes of the glaciated surface, snow line elevation and lakes formation in the headwaters of the Querecocha watershed in Cordillera Blanca (Perú). We also present the information derived from 10 short sediment cores (up to 50 cm long) retrieved along several transects in Yanamarey Lake. Both data sets inform of the sediment yield and lake development in recently deglaciated environments of the Andes. Results demonstrate that only one third of the surface covered by ice in 1975 remained in 2010. In this period, snowline has shifted up more than 100 meters in elevation in both, Yanamarey North and South areas respectively. At the same time, new lakes have been formed very quickly in these deglaciated areas. Preliminary 137Cs dating of Yanamarey sediment core indicates that at least the top 50 cm of the lake sequence deposited after 1960. This is coherent with the Landsat image of 1975 that showed the current surface of the lake still covered by ice. The high sediment rate (> 1 cm/yr) in the lake demonstrates the very high sediment yield in these geomorphically active settings. The sediment cores are composed of cm-thick sequences defined by grain-size (silt-clay) common in proglacial lakes reflecting the variability of hydrological response associated to the glacier retreat in the watershed during the analysed period. There is strong evidence that the Southern Oscillation Index drives much of the reported variability in glacier and lakes evolution in the studied area.

  14. Hydrology, nutrient concentrations, and nutrient yields in nearshore areas of four lakes in northern Wisconsin, 1999-2001

    USGS Publications Warehouse

    Graczyk, David J.; Hunt, Randall J.; Greb, Steven R.; Buchwald, Cheryl A.; Krohelski, James T.

    2003-01-01

    The effects of shoreline development on water quality and nutrient yields in nearshore areas of four lakes in northern Wisconsin were investigated from October 1999 through September 2001. The study measured surface runoff and ground-water flows from paired developed (sites containing lawn, rooftops, sidewalks, and driveways) and undeveloped (mature and immature woods) catchments adjacent to four lakes in northern Wisconsin. Water samples from surface runoff and ground water were collected and analyzed for nutrients. Coupled with water volumes, loads and subsequent yields of selected constituents were computed for developed and undeveloped catchments. The median runoff from lawn surfaces ranged from 0.0019 to 0.059 inch over the catchment area. Median surface runoff estimates from the wooded catchments were an order of magnitude less than those from the lawn catchments. The increased water volumes from the lawn catchments resulted in greater nutrient loads and subsequent annual nutrient yields from the developed sites. Soil temperature and soil moisture were measured at two sites with mixed lawn and wooded areas. At both of these sites, the area covered with a lawn commonly was warmer than the wooded area. No consistent differences in soil moisture were found. A ground-water model was constructed to simulate the local flow systems at two of the paired catchments. Model simulations showed that much of the ground water delivered to the lake originated from distant areas that did not contribute runoff directly to the lake. Surface runoff and ground-water nutrient concentrations from the lawn and wooded catchments did not have apparent patterns. Some of the median concentrations from lawns were significantly different (at the 0.05 significance level) from those at wooded catchments. Water wells and piezometers were sampled for chemical analyses three times during the study period. Variability in the shallow ground-water chemistry over time in the lawn samples was larger than samples from the wooded areas and upgradient wells. Median nutrient yields in surface runoff from lawns always were greater than those from the wooded catchments. Runoff volumes were the most important factor in determining whether lawns or wooded catchments contribute more nutrients to the lake. The ground-water system had appreciable nutrient concentrations, and are likely an important pathway for nutrient transport to the lake. The nitrate plus nitrite nitrogen and total phosphorus yields to the ground-water system from a lawn catchment were approximately 3 to 4 times greater than those from the wooded catchment. There was no difference in the yields of dissolved inorganic phosphorus to the ground-water system from the lawn and wooded catchments. Study results demonstrate that choosing the appropriate landscape position for locating lawns in sloped areas (specifically, slopes that do not terminate at the lake or areas with intervening flat or buffer zones between lawn and lake) can help reduce the adverse effect of lawns on the shallow ground water and, ultimately, the lake. Additional information would be needed to extrapolate these results to a large drainage area of a lake.

  15. Development of an Interactive Shoreline Management Tool for the Lower Wood River Valley, Oregon - Phase I: Stage-Volume and Stage-Area Relations

    USGS Publications Warehouse

    Haluska, Tana L.; Snyder, Daniel T.

    2007-01-01

    This report presents the parcel and inundation area geographic information system (GIS) layers for various surface-water stages. It also presents data tables containing the water stage, inundation area, and water volume relations developed from analysis of detailed land surface elevation derived from Light Detection and Ranging (LiDAR) data recently collected for the Wood River Valley at the northern margin of Agency Lake in Klamath County, Oregon. Former shoreline wetlands that have been cut off from Upper Klamath and Agency Lakes by dikes might in the future be reconnected to Upper Klamath and Agency Lakes by breaching the dikes. Issues of interest associated with restoring wetlands in this way include the area that will be inundated, the volume of water that may be stored, the change in wetland habitat, and the variation in these characteristics as surface-water stage is changed. Products from this analysis can assist water managers in assessing the effect of breaching dikes and changing surface-water stage. The study area is in the approximate former northern margins of Upper Klamath and Agency Lakes in the Wood River Valley.

  16. Using a coupled groundwater/surfacewater model to predict climate-change impacts to lakes in the Trout Lake watershed, Northern Wisconsin

    USGS Publications Warehouse

    Walker, John F.; Hunt, Randall J.; Markstrom, Steven L.; Hay, Lauren E.; Doherty, John

    2009-01-01

    A major focus of the U.S. Geological Survey’s Trout Lake Water, Energy, and Biogeochemical Budgets (WEBB) project is the development of a watershed model to allow predictions of hydrologic response to future conditions including land-use and climate change. The coupled groundwater/surface-water model GSFLOW was chosen for this purpose because it could easily incorporate an existing groundwater flow model and it provides for simulation of surface-water processes. The Trout Lake watershed in northern Wisconsin is underlain by a highly conductive outwash sand aquifer. In this area, streamflow is dominated by groundwater contributions; however, surface runoff occurs during intense rainfall periods and spring snowmelt. Surface runoff also occurs locally near stream/lake areas where the unsaturated zone is thin. A diverse data set, collected from 1992 to 2007 for the Trout Lake WEBB project and the co-located and NSF-funded North Temperate Lakes LTER project, includes snowpack, solar radiation, potential evapotranspiration, lake levels, groundwater levels, and streamflow. The timeseries processing software TSPROC (Doherty 2003) was used to distill the large time series data set to a smaller set of observations and summary statistics that captured the salient hydrologic information. The timeseries processing reduced hundreds of thousands of observations to less than 5,000. Model calibration included specific predictions for several lakes in the study area using the PEST parameter estimation suite of software (Doherty 2007). The calibrated model was used to simulate the hydrologic response in the study lakes to a variety of climate change scenarios culled from the IPCC Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Solomon et al. 2007). Results from the simulations indicate climate change could result in substantial changes to the lake levels and components of the hydrologic budget of a seepage lake in the flow system. For a drainage lake lower in the flow system, the impacts of climate change are diminished. 

  17. Methane Emissions from the Inland Waters of Alaska

    NASA Astrophysics Data System (ADS)

    Striegl, R. G.; Butman, D. E.; Stackpoole, S. M.; Dornblaser, M.

    2017-12-01

    Inland waters at high latitudes generally emit methane (CH4) continuously to the atmosphere during the open water season and build-up CH4 under ice during winter that is released over a short period following ice melt. Landscape position, stream and river size, water source, and turbulence created by water flow largely control CH4 emissions from streams and rivers. Organic carbon sources for CH4 production in lakes vary widely among lakes and landscapes and include hydrologic inputs from terrestrial sources, releases from permafrost thaw (thermokarst), and autochthonous inputs from aquatic macrophytes and algae. Lake emissions are therefore controlled by the balance between within-lake CH4 production and consumption, surface turbulence at the water-air interface, and CH4 ebullition. This creates a complex range of conditions that are difficult to characterize, where dissolved CH4 concentrations may vary by up to 4 orders of magnitude among lakes and/or within a single lake over an annual seasonal cycle. Moreover, large inputs of organic matter from permafrost thaw or other sources commonly result in high rates of bubble production and ebullition from some lakes, while other lakes have negligible ebullition. We quantified water surface areas and estimated CH4 emission rates for lakes, streams and rivers for the six major hydrologic regions of Alaska and determined that they collectively emit about 0.124 Tg C per year as CH4 to the atmosphere. Lake emissions comprise about 75% of the total. When adjusted for total land surface area in Alaska, our lake emission estimate is substantially smaller than previous global estimates for inland waters north of 50 degrees North latitude. We attribute this to incorporation of results that cover a broad range of lake conditions in interior Alaska and to new data from lakes in southwest Alaska that have very low CH4 concentration but very large surface area.

  18. Derivation of Lake Areas and Elevations for the Mackenzie Basin Using Satellite Remote Sensing

    NASA Technical Reports Server (NTRS)

    Birkett, Charon; Kite, Geoff

    1997-01-01

    Modelling hydrological processes in large watersheds flowing to the Arctic ocean is one step towards larger-scale modelling of the global water and energy cycles. Models of the Mackenzie River Basin (Northern Canada) are currently available but omit explicit routing of river flows through the three main lakes - Athabasca, Great Slave Lake and Great Bear Lake (Kite et al, 1994). These lakes occupy an area of 65,000 sq km but little gauge information is available. The levels of the lakes are only measured at a few points on the circumferences and river flows are only measured downstream. The hydraulic relationships between level/discharge and level/area/volume are uncertain. It has been previously shown that satellite remote sensing can be utilised in providing measurements of both lake surface area using imaging techniques and lake level using radar altimetry (Birkett, 1994). Here, we explore the application of these techniques to derive the lake levels and areas for the Mackenzie Basin lakes.

  19. Hydrology of Lake Carroll, Hillsborough County, Florida

    USGS Publications Warehouse

    Henderson, S.E.; Hayes, R.D.; Stoker, Y.E.

    1985-01-01

    Lakeshore property around Lake Carroll has undergone extensive residential development since 1960. This development increased the lake shoreline, altered surface water flow to and from the lake, and may have affected lake-stage characteristics. Some areas of the lake were dredged to provide fill material for lakefront property. Water-balance analyses for 1952-60, a predevelopment period, and 1961-80, a period of residential development, indicate that both net surface water flow to the lake and downward leakage from the lake to the Floridan aquifer were greater after 1960. These changes were due more to changes in the regional climate and related changes in ground-water levels than to changes associated with residential development. Results of water quality analyses in 1980-81 are within State limits for surface waters used for recreation and wildlife propagation. (USGS)

  20. Methane Emissions from Small Lakes: Dynamics and Distribution Patterns

    NASA Astrophysics Data System (ADS)

    Encinas Fernández, J. M.; Peeters, F.; Hofmann, H.

    2014-12-01

    The dynamics of dissolved methane were measured during three years in five small lakes with different surface areas and maximum water depth. We analyze and compare the horizontal and vertical distribution of dissolved methane within these lakes during different time periods: the stratified period in summer, the autumn overturn, the winter mixing period, and the period from spring to summer stratification. The horizontal distributions of dissolved methane within the lakes suggest that the relation between surface area and maximum water-depth is a key factor determining the heterogeneity of methane concentrations in the surface water. During most of the year littoral zones are the main source of the methane that is emitted to the atmosphere except for the overturn periods. The vertical distributions of temperature and dissolved oxygen within the different seasons affect the vertical distribution of dissolved methane and thus the methane budget within lakes. Anoxic conditions in the hypolimnion and the intense mixing during overturn periods are key factors for the overall annual methane emissions from lakes.

  1. Characteristics and causal factors of hysteresis in the hydrodynamics of a large floodplain system: Poyang Lake (China)

    NASA Astrophysics Data System (ADS)

    Zhang, X. L.; Zhang, Q.; Werner, A. D.; Tan, Z. Q.

    2017-10-01

    A previous modeling study of the lake-floodplain system of Poyang Lake (China) revealed complex hysteretic relationships between stage, storage volume and surface area. However, only hypothetical causal factors were presented, and the reasons for the occurrence of both clockwise and counterclockwise hysteretic functions were unclear. The current study aims to address this by exploring further Poyang Lake's hysteretic behavior, including consideration of stage-flow relationships. Remotely sensed imagery is used to validate the water surface areas produced by hydrodynamic modeling. Stage-area relationships obtained using the two methods are in strong agreement. The new results reveal a three-phase hydrological regime in stage-flow relationships, which assists in developing improved physical interpretation of hysteretic stage-area relationships for the lake-floodplain system. For stage-area relationships, clockwise hysteresis is the result of classic floodplain hysteretic processes (e.g., restricted drainage of the floodplain during recession), whereas counterclockwise hysteresis derives from the river hysteresis effect (i.e., caused by backwater effects). The river hysteresis effect is enhanced by the time lag between the peaks of catchment inflow and Yangtze discharge (i.e., the so-called Yangtze River blocking effect). The time lag also leads to clockwise hysteresis in the relationship between Yangtze River discharge and lake stage. Thus, factors leading to hysteresis in other rivers, lakes and floodplains act in combination within Poyang Lake to create spatial variability in hydrological hysteresis. These effects dominate at different times, in different parts of the lake, and during different phases of the lake's water level fluctuations, creating the unique hysteretic hydrological behavior of Poyang Lake.

  2. Monitoring monthly surface water dynamics of Dongting Lake using Sentinel-1 data at 10 m.

    PubMed

    Xing, Liwei; Tang, Xinming; Wang, Huabin; Fan, Wenfeng; Wang, Guanghui

    2018-01-01

    High temporal resolution water distribution maps are essential for surface water monitoring because surface water exhibits significant inner-annual variation. Therefore, high-frequency remote sensing data are needed for surface water mapping. Dongting Lake, the second-largest freshwater lake in China, is famous for the seasonal fluctuations of its inundation extents in the middle reaches of the Yangtze River. It is also greatly affected by the Three Gorges Project. In this study, we used Sentinel-1 data to generate surface water maps of Dongting Lake at 10 m resolution. First, we generated the Sentinel-1 time series backscattering coefficient for VH and VV polarizations at 10 m resolution by using a monthly composition method. Second, we generated the thresholds for mapping surface water at 10 m resolution with monthly frequencies using Sentinel-1 data. Then, we derived the monthly surface water distribution product of Dongting Lake in 2016, and finally, we analyzed the inner-annual surface water dynamics. The results showed that: (1) The thresholds were -21.56 and -15.82 dB for the backscattering coefficients for VH and VV, respectively, and the overall accuracy and Kappa coefficients were above 95.50% and 0.90, respectively, for the VH backscattering coefficient, and above 94.50% and 0.88, respectively, for the VV backscattering coefficient. The VV backscattering coefficient achieved lower accuracy due to the effect of the wind causing roughness on the surface of the water. (2) The maximum and minimum areas of surface water were 2040.33 km 2 in July, and 738.89 km 2 in December. The surface water area of Dongting Lake varied most significantly in April and August. The permanent water acreage in 2016 was 556.35 km 2 , accounting for 19.65% of the total area of Dongting Lake, and the acreage of seasonal water was 1525.21 km 2 . This study proposed a method to automatically generate monthly surface water at 10 m resolution, which may contribute to monitoring surface water in a timely manner.

  3. Rapid increase of lakes in Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ren, H.; Fan, W.; Yao, Y., Sr.; Tian, D.; MA, B.; LIU, R.; Qin, Q.

    2016-12-01

    The Tibetan Plateau, covered with a huge area of snow, glaciers and lakes, feeds several large rivers, incluidng Yangtze River, Yellow River, Yarlung Tsangpo River and Lancang River. Climate change can cause lakes to expand and bring floods and mudflows, and the response of lakes in this plateau to global climate change is very crucial. Using time-series Landsats clear-sky images in summer from the late 1980s to 2015, we established a new finer-resolution (30m) database of lakes in the plateau among five stages (1980s, 1995, 2000, 2005 and 2015), analyzed lake changes in the past three decades, and explored the possible driving forces. Results and discussions(1) Changes in lakes > 1km2 between 1980s and 2015The changes of lake numbers and surface areas were investigated between 1980s and 2015. The lakes were identified by visual interpretation and classified to several different sizes: small (1-10km2), medium (10-50km2), large (50-100km2) and huge (>100km2) lakes. A total of 1375 lakes (>1km2) were detected in 2015, in which the small, medium, large and huge lakes respectively account for 97, 74, 262 and 942 (Fig.1 and Table 1). The numbers of lakes (> 1km2 ) has increased by 384 from 991 in 1980s (Fig.2 a, b). Meanwhile, a rapid increase of lake surface area also occurred: increased by 28.2% from 37711.0km2 in 1980s to 48335.2km2 in 2015 (Fig.2c and Table 1). (2) Temporal changes in lakes > 10km2 between 1980s and 2015Temporal variation in all lakes > 10km2 were investigated at the five stages. Most lakes have expanded (Fig.3). The water surface area of large and huge lakes increased by 13.7% from a total area of 32056.7km2 in 1980s to 36437.0km2 in 2015. For example, Siling Co, which is the largest lake in Tibet region and second largest lake in Tibetan Plateau, has increased by 702.1 km2 (41.0%) to 2416.08 km2 since 1980s with an rate about 28 km2 /a. Some new lakes or water bodies appeared due to melting glaciers or anthropogenic intervention. A few of small lakes were dried up. (3) Effects analysis on Lake changesWe used annual average temperature (AVT), annual precipitation (AP), snow cover (SC) and glacier cover (GC) in spring, and lake salt mining (LSM). The preliminary results shows that the AVT anomaly and GC are the possible drivers for most lake changes, while some lakes are affected by LSM. More details are still on investigation.

  4. Environmental and Groundwater Controls on Evaporation Rates of A Shallow Saline Lake in the Western Sandhills Nebraska, USA

    NASA Astrophysics Data System (ADS)

    Peake, C.; Riveros-Iregui, D.; Lenters, J. D.; Zlotnik, V. A.; Ong, J.

    2013-12-01

    The western Sand Hills of Nebraska exhibit many shallow saline lakes that actively mediate groundwater-lake-atmospheric exchanges. The region is home to the largest stabilized dune field in the western hemisphere. Most of the lakes in the western Sand Hills region are saline and support a wide range of ecosystems. However, they are also highly sensitive to variability in evaporative and groundwater fluxes, which makes them a good laboratory to examine the effects of climate on the water balance of interdunal lakes. Despite being semiarid, little is known about the importance of groundwater-surface water interactions on evaporative rates, or the effects of changes in meteorological and energy forcings on the diel, and seasonal dynamics of evaporative fluxes. Our study is the first to estimate evaporation rates from one of the hundreds of shallow saline lakes that occur in the western Sand Hills region. We applied the energy balance Bowen ratio method at Alkali Lake, a typical saline western Sand Hills lake, over a three-year period (2007-2009) to quantify summer evaporation rates. Daily evaporation rates averaged 5.5 mm/day from July through September and were largely controlled by solar radiation on a seasonal and diel scales. Furthermore, the range of annual variability of evaporation rates was low. Although less pronounced, groundwater level effects on evaporation rates were also observed, especially from August through October when solar radiation was lower. The lake exhibits significant fluctuation in lake levels and combined with a shallow lake bed, large changes in lake surface area are observed. Our findings also show that with the onset of summer conditions, lake surface area can change very rapidly (e.g. 24% of its surface area or ~16.6 hectares were lost in less than ~2 months). In every year summer evaporation exceeded annual rainfall by an average of 28.2% suggesting that groundwater is a significant component of the lake water balance, it is important for sustaining life of surrounding ecosystems, and during the growing season it is transiently stored in the lake before it is rapidly lost to the atmosphere.

  5. Abundance and morphometry changes across the high-mountain lake-size gradient in the tropical Andes of Southern Ecuador

    NASA Astrophysics Data System (ADS)

    Mosquera, Pablo V.; Hampel, Henrietta; Vázquez, Raúl F.; Alonso, Miguel; Catalan, Jordi

    2017-08-01

    The number, size, and shape of lakes are key determinants of the ecological functionality of a lake district. The lake area scaling relationships with lake number and volume enable upscaling biogeochemical processes and spatially considering organisms' metapopulation dynamics. These relationships vary regionally depending on the geomorphological context, particularly in the range of lake area <1 km2 and mountainous regions. The Cajas Massif (Southern Ecuador) holds a tropical mountain lake district with 5955 water bodies. The number of lakes deviates from a power law relationship with the lake area at both ends of the size range; similarly to the distributions found in temperate mountain ranges. The deviation of each distribution tail does not respond to the same cause. The marked relief limits the size of the largest lakes at high altitudes, whereas ponds are prompt to a complete infilling. A bathymetry survey of 202 lakes, selected across the full-size range, revealed a volume-area scaling coefficient larger than those found for other lake areas of glacial origin but softer relief. Water renewal time is not consistently proportional to the lake area due to the volume-area variation in midsize lakes. The 85% of the water surface is in lakes >104 m2 and 50% of the water resources are held in a few ones (˜10) deeper than 18 m. Therefore, midlakes and large lakes are by far more biogeochemically relevant than ponds and shallow lakes in this tropical mountain lake district.

  6. Effects of lake surface elevation on shoreline-spawning Lost River Suckers

    USGS Publications Warehouse

    Burdick, Summer M.; Hewitt, David A.; Rasmussen, J.E.; Hayes, Brian; Janney, Eric; Harris, Alta C.

    2015-01-01

    We analyzed remote detection data from PIT-tagged Lost River Suckers Deltistes luxatus at four shoreline spawning areas in Upper Klamath Lake, Oregon, to determine whether spawning of this endangered species was affected by low water levels. Our investigation was motivated by the observation that the surface elevation of the lake during the 2010 spawning season was the lowest in 38 years. Irrigation withdrawals in 2009 that were not replenished by subsequent winter-spring inflows caused a reduction in available shoreline spawning habitat in 2010. We compared metrics of skipped spawning, movement among spawning areas, and spawning duration across 8 years (2006-2013) that had contrasting spring water levels. Some aspects of sucker spawning were similar in all years, including few individuals straying from the shoreline areas to spawning locations in lake tributaries and consistent effects of increasing water temperatures on the accumulation of fish at the spawning areas. During the extreme low water year of 2010, 14% fewer female and 8% fewer male suckers joined the shoreline spawning aggregation than in the other years. Both males and females visited fewer spawning areas within Upper Klamath Lake in 2010 than in other years, and the median duration at spawning areas in 2010 was at least 36% shorter for females and 20% shorter for males relative to other years. Given the imperiled status of the species and the declining abundance of the population in Upper Klamath Lake, any reduction in spawning success and egg production could negatively impact recovery efforts. Our results indicate that lake surface elevations above 1,262.3-1,262.5 m would be unlikely to limit the number of spawning fish and overall egg production.

  7. Recreational fishing in surface mine lakes - a case study in St. Clair County, Illinois

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mannz, R.H.

    1985-12-09

    Recent mining legislation mandates the reclamation of surface-mined areas to the pre-mining contour, eliminating the potential of many new lakes. However, many pre-law mine lakes have considerable recreational value benefiting the surrounding regions. During 1983, 5296 anglers participated in Peabody Coal Company's Coal Company's recreational fishing program in St. Clair County, Illinois. A random sample of participants were mailed a questionnaire designed to identify user/area characteristics economic implications, and sport fishing resources of the program lakes. Sample data indicated 62,760 angling days spent on 600 acres of program waters during 1983. The single most sought after fish was the largemore » mouth bass. Expenditures by 1983 program users were estimated at $753,120 or $1255 per acre of surface water. Opportunity cost calculations indicated that recreational fishing was an equal or better trade-off to the regional economy when compared to income that could have been produced from rowcrop agriculture. Reclamation techniques designed for fish and wildlife purposes and leaving such areas should be encouraged. Returning surface-mined areas to the pre-mining contour and use is not necessarily the most cost effective or desirable method of reclamation. 14 references, 4 tables.« less

  8. A RESEARCH PLAN FOR THE USE OF THERMAL AVHRR IMAGERY TO STUDY ANNUAL AND SEASONAL MEAN SURFACE TEMPERATURES FOR LARGE LAKES IN NORTH AMERICA

    EPA Science Inventory

    Surface and vertical temperature data will be obtained from several large lakes With surface areas large enough to be effectively sampled with AVHRR imagery. Yearly and seasonal patterns of surface and whole water column thermal values will be compared to estimates of surface tem...

  9. Annual maximum and minimum lake levels for Indiana, 1942-85

    USGS Publications Warehouse

    Fowler, Kathleen K.

    1988-01-01

    Indiana has many natural and manmade lakes. Lake-level data are available for 217 lakes. These data were collected during water years 1942-85 by use of staff gages and, more recently, continuous recorders. The period of record at each site ranges from 1 to 43 years. Data from the lake stations have been compiled, and maximum and minimum lake levels for each year of record are reported. In addition to annual maximum and minimum lake levels, each lake station is described by gage location, surface area, drainage area, period of record, datum of gage, gage type, established legal level, lake level control, inlets and outlets, and extremes for the period of record. 

  10. Water resources of the New Orleans area, Louisiana

    USGS Publications Warehouse

    Eddards, Miles LeRoy; Kister, L.R.; Scarcia, Glenn

    1956-01-01

    Industry, commerce, and public utilities in 1954 withdrew about 1,500 mgd from surface- and groundwater sources in the New Orleans area. Most of the withdrawal was made from the Mississippi River. However, some withdrawal of surface water was made from Lake Pontchartrain. A large part of the withdrawal from both ground- and surface-water sources is available for reuse. Ground-water withdrawal amounts to about 100 mgd and is primarily for industrial and commercial uses. The average flow of the Mississippi River for the 23-year period, 1931--54, amounted to 309,000 mgd, and the approximate average flow of all the tributaries to Lake Pontchartrain is about 4,000 mgd. The flow of the Pearl River, which adjoins the tributary drainage area of Lake Pontchartrain, averages about 8,000 mgd. Total withdrawal of ground and surface waters amounts to less than 3 percent of the recorded minimum flow of the Mississippi River or less than 1 percent of the average flow. Although large quantities of water are always available in the Mississippi River the quality of the Water is not suitable for all uses. Streams from the north that drain into Lakes Maurepas and Pontchartrain, and the aquifers in that area, offer one of the best sources of fresh water in the State. Industry, if located on the northern shores of Lake Maurepas or Lake Pontchartrain near the mouths of these tributaries, would be assured of an ample supply of either ground or surface water of excellent quality. All the tributaries north of Lake Pontchartrain have dry-weather flows which are dependable. The Pearl River above Bogalusa also is a good source of fresh water of excellent quality. At present it serves to dilute the tidal flow of salt water into Lake Pontchartrain through the Rigolets, the principal outlet of the lake. In the area north of Lake Pontchartrain, wells 60 to 2,000 feet deep yield fresh water. There are no known wells tapping sands below 2,000 feet. However, electrical logs of. oil-test wells show that fresh water is available to a maximum depth of 3,000 feet. In the area south of Lake Pontchartrain, there is no withdrawal of ground water for public water supplies because of the saline content of the water. Three principal water-bearing sands, the '200-foot, ' '400-foot, ' and '700-foot'sands, are tapped in the New Orleans area south of Lake Pontchartrain for industrial and commercial use. In this area all deeper sands yield salt water. In some areas the '200-foot' sand contains saline water of the sodium chloride type. Consequently, this sand is not developed extensively. Water from the 200-foot' sand is relatively fresh north of the Mississippi River and becomes increasingly saline to the south and west. The 400-foot' sand is the second most highly developed aquifer in the New Orleans industrial district. The aquifer appears to be very prolific, but its full capabilities have not yet been determined. This aquifer yields a highly mineralized sodium chloride water in some areas; however, elsewhere it is a source of large quantities of fresh water. The '700-foot' sand is the most continuous freshwater bearing sand in the area and is the principal source of fresh ground water in the New Orleans industrial district. Most of the wells tapping this aquifer yield soft water of the bicarbonate type. In the southern and western parts of the industrial district the water in the '700-foot' sand is too mineralized to be suitable for human consumption.

  11. Predicting water-surface fluctuation of continental lakes: A RS and GIS based approach in Central Mexico

    USGS Publications Warehouse

    Mendoza, M.E.; Bocco, G.; Bravo, M.; Lopez, Granados E.; Osterkamp, W.R.

    2006-01-01

    Changes in the water-surface area occupied by the Cuitzeo Lake, Mexico, during the 1974-2001 period are analysed in this study. The research is based on remote sensing and geographic information techniques, as well as statistical analysis. High-resolution satellite image data were used to analyse the 1974-2000 period, and very low-resolution satellite image data were used for the 1997-2001 period. The long-term analysis (1974-2000) indicated that there were temporal changes in the surface area of the Cuitzeo Lake and that these changes were related to precipitation and temperatures that occurred in the previous year. Short-term monitoring (1997-2001) showed that the Cuitzeo Lake surface is lowering. Field observations demonstrated also that yearly desiccation is recurrent, particularly, in the western section of the lake. Results suggested that this behaviour was probably due to a drought period in the basin that began in the mid 1990s. Regression models constructed from long-term data showed that fluctuations of lake level can be estimated by monthly mean precipitation and temperatures of the previous year. ?? Springer Science + Business Media, Inc. 2006.

  12. Enhancement of sediment phosphorus release during a tunnel construction across an urban lake (Lake Donghu, China).

    PubMed

    Wang, Siyang; Li, Hui; Xiao, Jian; Zhou, Yiyong; Song, Chunlei; Bi, Yonghong; Cao, Xiuyun

    2016-09-01

    Tunnel construction in watershed area of urban lakes would accelerate eutrophication by inputting nutrients into them, while mechanisms underlying the internal phosphorus cycling as affected by construction events are scarcely studied. Focusing on two main pathways of phosphorus releasing from sediment (enzymatic mineralization and anaerobic desorption), spatial and temporal variations in phosphorus fractionation, and activities of extracellular enzymes (alkaline phosphatase, β-1,4-glucosidase, leucine aminopeptidase, dehydrogenase, lipase) in sediment were examined, together with relevant parameters in interstitial and surface waters in a Chinese urban lake (Lake Donghu) where a subaqueous tunnel was constructed across it from October 2013 to July 2014. Higher alkaline phosphatase activity (APA) indicated phosphorus deficiency for phytoplankton, as illustrated by a significantly negative relationship between APA and concentration of dissolved total phosphorus (DTP). Noticeably, in the construction area, APAs in both sediment and surface water were significantly lower than those in other relevant basins, suggesting a phosphorus supply from some sources in this area. In parallel, its sediment gave the significantly lower iron-bound phosphorus (Fe(OOH)∼P) content, coupled with significantly higher ratio of iron (II) to total iron content (Fe(2+)/TFe) and dehydrogenase activities (DHA). Contrastingly, difference in the activities of sediment hydrolases was not significant between the construction area and other basins studied. Thus, in the construction area, subsidy of bioavailable phosphorus from sediment to surface water was attributable to the anaerobic desorption of Fe(OOH)∼P rather than enzymatic mineralization. Finally, there existed a significantly positive relationship between chlorophyll a concentration in surface water and Fe(OOH)∼P content in sediment. In short, construction activities within lakes may interrupt cycling patterns of phosphorus across sediment-water interface by enhancing release of redox-sensitive phosphate, and thereby facilitating phytoplankton growth in water column.

  13. Earth observations taken during STS-83 mission

    NASA Image and Video Library

    2016-08-12

    STS083-747-026 (4-8 April 1997) --- Aswan Dam and Lake Nasser along the Nile River, Egypt. The Aswan Dam controls the flow of the Nile River forming Lake Nasser. Lake Nasser is reaching relatively high water levels due to the plentiful rains since December 1996 in Kenya, near the headwaters of the Nile river. The light colored areas in the Lake are where the sun is reflecting off the surface of the water. These areas are fairly calm and not disturbed by wind gusts enabling the sunglint to show water current patterns on the surface. The Aswan runway is seen as a dark set of lines west of the Aswan Dam.

  14. Influence of lake surface area and total phosphorus on annual bluegill growth in small impoundments of central Georgia

    USGS Publications Warehouse

    Jennings, Cecil A.; Sundmark, Aaron P.

    2017-01-01

    The relationships between environmental variables and the growth rates of fishes are important and rapidly expanding topics in fisheries ecology. We used an informationtheoretic approach to evaluate the influence of lake surface area and total phosphorus on the age-specific growth rates of Lepomis macrochirus (Bluegill) in 6 small impoundments in central Georgia. We used model averaging to create composite models and determine the relative importance of the variables within each model. Results indicated that surface area was the most important factor in the models predicting growth of Bluegills aged 1–4 years; total phosphorus was also an important predictor for the same age-classes. These results suggest that managers can use water quality and lake morphometry variables to create predictive models specific to their waterbody or region to help develop lake-specific management plans that select for and optimize local-level habitat factors for enhancing Bluegill growth.

  15. Long-Term Remote Monitoring of Three Typical Lake Area Variations in the Northwest China Over the Past 40 Years

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Lu, Y.; Li, Y.; Yue, H.

    2018-04-01

    water resources management and sustainable development strategy, but also provide reference for assessing the impact of climate change and human activities. This paper selects three inland lakes in Northwest China, using Landsat MSS/TM/ETM+/OLI data from 1970 to 2015, Normalized Difference Water Index (NDWI) and Modified Normalized Difference Water Index (MNDWI) were used to extract lake area and analysed the dynamic trends. Meteorological station rainfall, evaporation and other meteorological data of the lakes were used to analyse reasons for the area change. The results showed that area of Hongjiannao Lake in the past 40 a was reduced, the groundwater impoundment and underground coal mining are the main cause of area reduction; the area of Bosten Lake in recent 40 a showed a decreasing trend after the first increase, the area was mainly affected by the surface runoff and snowmelt; the area of Qinghai Lake in the past 40 a shows a trend of decreasing first and then increasing, the change of its area is mainly affected by regional precipitation and the inflow.

  16. Preliminary Water-Table Map and Water-Quality Data for Part of the Matanuska-Susitna Valley, Alaska, 2005

    USGS Publications Warehouse

    Moran, Edward H.; Solin, Gary L.

    2006-01-01

    The Matanuska-Susitna Valley is in the northeastern part of the Cook Inlet Basin, Alaska, an area experiencing rapid population growth and development proximal to many lakes. Here water commonly flows between lakes and ground water, indicating interrelation between water quantity and quality. Thus concerns exist that poorer quality ground water may degrade local lake ecosystems. This concern has led to water-quality sampling in cooperation with the Alaska Department of Environmental Conservation and the Matanuska-Susitna Borough. A map showing the estimated altitude of the water table illustrates potential ground-water flow directions and areas where ground- and surface-water exchanges and interactions might occur. Water quality measured in selected wells and lakes indicates some differences between ground water and surface water. 'The temporal and spatial scarcity of ground-water-level and water-quality data limits the analysis of flow direction and water quality. Regionally, the water-table map indicates that ground water in the eastern and southern parts of the study area flows southerly. In the northcentral area, ground water flows predominately westerly then southerly. Although ground and surface water in most areas of the Matanuska-Susitna Valley are interconnected, they are chemically different. Analyses of the few water-quality samples collected in the area indicate that dissolved nitrite plus nitrate and orthophosphorus concentrations are higher in ground water than in surface water.'

  17. Bathymetric contour maps of lakes surveyed in Iowa in 2004

    USGS Publications Warehouse

    Linhart, S. Mike; Lund, Kris D.

    2006-01-01

    Bathymetric data were collected using a boat-mounted, differential global positioning system, echo depth-sounding equipment, and computer software. Data were processed with commercial hydrographic software and exported into a geographic information system for mapping and calculating area and volume. Lake volume estimates ranged from 83,924,000 cubic feet (1,930 acre-feet) at Lake Darling to 5,967,000 cubic feet (140 acre-feet) at Upper Gar Lake. Surface area estimates ranged from 10,660,000 square feet (240 acres) at Lake Darling to 1,557,000 square feet (36 acres) at Upper Gar Lake.

  18. Bathymetric contour maps for lakes surveyed in Iowa in 2003

    USGS Publications Warehouse

    Linhart, S. Mike; Lund, Kris D.

    2006-01-01

    Bathymetric data were collected using boat-mounted, differential global positioning system (GPS) equipment, echo depth-sounding equipment, and computer software. Data were processed with commercial hydrographic software and exported into a geographic information system (GIS) for mapping and calculation of area and volume. Lake volume estimates ranged from 590,501,000 cubic feet (13,600 acre-feet) at Lake Macbride to 17,831,000 cubic feet (410 acre-feet) at Lake Meyer. Surface area estimates ranged from 38,118,000 square feet (875 acres) at Lake Macbride to 1,373,000 square feet (32 acres) at Lake Meyer.

  19. Extraction and representation of nested catchment areas from digital elevation models in lake-dominated topography

    NASA Astrophysics Data System (ADS)

    Mackay, D. Scott; Band, Lawrence E.

    1998-04-01

    This paper presents a new method for extracting flow directions, contributing (upslope) areas, and nested catchments from digital elevation models in lake-dominated areas. Existing tools for acquiring descriptive variables of the topography, such as surface flow directions and contributing areas, were developed for moderate to steep topography. These tools are typically difficult to apply in gentle topography owing to limitations in explicitly handling lakes and other flat areas. This paper addresses the problem of accurately representing general topographic features by first identifying distinguishing features, such as lakes, in gentle topography areas and then using these features to guide the search for topographic flow directions and catchment marking. Lakes are explicitly represented in the topology of a watershed for use in water routing. Nonlake flat features help guide the search for topographic flow directions in areas of low signal to noise. This combined feature-based and grid-based search for topographic features yields improved contributing areas and watershed boundaries where there are lakes and other flat areas. Lakes are easily classified from remotely sensed imagery, which makes automated representation of lakes as subsystems within a watershed system tractable with widely available data sets.

  20. Improvements in lake water budget computations using Landsat data

    NASA Technical Reports Server (NTRS)

    Gervin, J. C.; Shih, S. F.

    1979-01-01

    A supervised multispectral classification was performed on Landsat data for Lake Okeechobee's extensive littoral zone to provide two types of information. First, the acreage of a given plant species as measured by satellite was combined with a more accurate transpiration rate to give a better estimate of evapotranspiration from the littoral zone. Second, the surface area coupled by plant communities was used to develop a better estimate of the water surface as a function of lake stage. Based on this information, more detailed representations of evapotranspiration and total water surface (and hence total lake volume) were provided to the water balance budget model for lake volume predictions. The model results based on information derived from satellite demonstrated a 94 percent reduction in cumulative lake stage error and a 70 percent reduction in the maximum deviation of the lake stage.

  1. Estimating the volume of Alpine glacial lakes

    NASA Astrophysics Data System (ADS)

    Cook, S. J.; Quincey, D. J.

    2015-12-01

    Supraglacial, moraine-dammed and ice-dammed lakes represent a potential glacial lake outburst flood (GLOF) threat to downstream communities in many mountain regions. This has motivated the development of empirical relationships to predict lake volume given a measurement of lake surface area obtained from satellite imagery. Such relationships are based on the notion that lake depth, area and volume scale predictably. We critically evaluate the performance of these existing empirical relationships by examining a global database of glacial lake depths, areas and volumes. Results show that lake area and depth are not always well correlated (r2 = 0.38) and that although lake volume and area are well correlated (r2 = 0.91), and indeed are auto-correlated, there are distinct outliers in the data set. These outliers represent situations where it may not be appropriate to apply existing empirical relationships to predict lake volume and include growing supraglacial lakes, glaciers that recede into basins with complex overdeepened morphologies or that have been deepened by intense erosion and lakes formed where glaciers advance across and block a main trunk valley. We use the compiled data set to develop a conceptual model of how the volumes of supraglacial ponds and lakes, moraine-dammed lakes and ice-dammed lakes should be expected to evolve with increasing area. Although a large amount of bathymetric data exist for moraine-dammed and ice-dammed lakes, we suggest that further measurements of growing supraglacial ponds and lakes are needed to better understand their development.

  2. Estimating the volume of Alpine glacial lakes

    NASA Astrophysics Data System (ADS)

    Cook, S. J.; Quincey, D. J.

    2015-09-01

    Supraglacial, moraine-dammed and ice-dammed lakes represent a potential glacial lake outburst flood (GLOF) threat to downstream communities in many mountain regions. This has motivated the development of empirical relationships to predict lake volume given a measurement of lake surface area obtained from satellite imagery. Such relationships are based on the notion that lake depth, area and volume scale predictably. We critically evaluate the performance of these existing empirical relationships by examining a global database of measured glacial lake depths, areas and volumes. Results show that lake area and depth are not always well correlated (r2 = 0.38), and that although lake volume and area are well correlated (r2 = 0.91), there are distinct outliers in the dataset. These outliers represent situations where it may not be appropriate to apply existing empirical relationships to predict lake volume, and include growing supraglacial lakes, glaciers that recede into basins with complex overdeepened morphologies or that have been deepened by intense erosion, and lakes formed where glaciers advance across and block a main trunk valley. We use the compiled dataset to develop a conceptual model of how the volumes of supraglacial ponds and lakes, moraine-dammed lakes and ice-dammed lakes should be expected to evolve with increasing area. Although a large amount of bathymetric data exist for moraine-dammed and ice-dammed lakes, we suggest that further measurements of growing supraglacial ponds and lakes are needed to better understand their development.

  3. Hydrologic reconnaissance of Tsala Apopka Lake, Citrus County, Florida

    USGS Publications Warehouse

    Rutledge, A.T.

    1977-01-01

    The swamps, marshes, and open waters of Tsala Apopka Lake, Florida, were mapped and the hydrologic connection between the lake and the Floridan limestone aquifer was studied from October 1975 to September 1976. Tsala Apopka Lake is a series of shallow , interconnected lakes, ponds, and marshes whose water surface slopes northward at 0.5 foot per mile. According to aerial photographs of December 1972, only 6 percent of the 103 square miles of study area is covered by open water. Open water is abundant along the western side of the lake, dense and sparse marshes occupy most of the lake area, and swamps occupy a thick zone around the Withlacoochee River which borders the lake to the east. Only a small fraction of the total surface flow occurs through the lake. The average lake outflow through S-351 canal is 23.6 cfs; while the average river flow at Holder is 714 cfs. Tsala Apopka Lake is hydraulically connected to the Floridan aquifer. At low flow, the major source of water in the river is ground water from the Floridan aquifer. The specific conductance of water in the Floridan aquifer averages 250-350 umho/cm (micromhos per centimeter) at 25C in this area. The specific conductance of water in the Withlacoochee River near Holder averages 268 umho/cm at 25C, while water in Tsala Apopka Lake at Hernando averages 139 umho/cm at 25C. (Woodard-USGS)

  4. Heat Capacity Mapping Mission (HCMM) thermal surface water mapping and its correlation to LANDSAT. [Lake Anna, Virginia

    NASA Technical Reports Server (NTRS)

    Colvocoresses, A. P. (Principal Investigator)

    1980-01-01

    Graphics are presented which show HCMM mapped water-surface temperature in Lake Anna, a 13,000 dendrically-shaped lake which provides cooling for a nuclear power plant in Virginia. The HCMM digital data, produced by NASA were processed by NOAA/NESS into image and line-printer form. A LANDSAT image of the lake illustrates the relationship between MSS band 7 data and the HCMM data as processed by the NASA image processing facility which transforms the data to the same distortion-free hotline oblique Mercator projection. Spatial correlation of the two images is relatively simple by either digital or analog means and the HCMM image has a potential accuracy approaching the 80 m of the original LANDSAT data. While it is difficult to get readings that are not diluted by radiation from cooler adjacent land areas in narrow portions of the lake, digital data indicated by the line-printer display five different temperatures for open-water areas. Where the water surface response was not diluted by land areas, the temperature difference recorded by HCMM corresponds to in situ readings with rsme on the order of 1 C.

  5. Stable isotope (O and C) and pollen trends in eastern Lake Erie, evidence for a locally-induced climatic reversal of Younger Dryas age in the Great Lakes basin

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lewis, C.F.M.; Anderson, T.W.

    A cool period from about 11000 to 10500 BP (11 to 10.5 ka) is recognized in pollen records from the southern Great Lakes area by the return of Picea and Abies dominance and by the persistence of herbs. The area of cooling appears centred on the Upper Great Lakes. A high-resolution record (ca. 9 mm/y) from a borehole in eastern Lake Erie reveals, in the same time interval, this pollen anomaly, isotope evidence of melt-water presence (a-3 per mil shift in {delta} {sup 18}O and a + 1.1 per mil shift in {delta}{sup 13}C), increased sand, and reduced detrital calcitemore » content, all suggesting concurrent cooling of Lake Erie. The onset of cooling is mainly attributed to the effect of enhanced meltwater inflow on the relatively large upstream Main Lake Agassiz. Termination of the cooling coincides with drainage of Lake Algonquin, and is attributed to loss of its cooling effectiveness associated with a substantial reduction in its surface area. It is hypothesized that that the cold extra in-flow effectively prolonged the seasonal presence of lake ice and the period of spring overturn in Lake Algonquin. The deep mixing would have greatly increased the thermal conductive capacity of this extensive lake, causing suppression of summer surface lakewater temperatures and reduction of onshore growing-degree days. Alternatively, a rapid flow of meltwater, buoyed on sediment-charged (denser) lakewater, may have kept the lake surface cold in summer. Other factors such as wind-shifted pollen deposition and possible effects from the Younger Dryas North Atlantic cooling could have contributed to the Great Lakes climatic reversal, but further studies are needed to resolve their relative significance. 51 refs., 5 figs.« less

  6. ARE COASTAL WETLAND-LAKE LINKAGES IMPORTANT?

    EPA Science Inventory

    Because coastal werlands typically comprise only a small percentage of the overall surface area in large lakes, an assumption has often been made that functional links between wetlands and the lake proper are of little significance. Recent investigations of functional linkages be...

  7. War Damage Assessment

    NASA Technical Reports Server (NTRS)

    1994-01-01

    During and after the Persian Gulf war, hundreds of "oil lakes" were created in Kuwait by oil released from damaged wells. The lakes are a hazard to the Kuwait atmosphere, soil and ground water and must be carefully monitored. Boston University Center for Remote Sensing, assisted by other organizations, has accurately mapped the lakes using Landsat and Spot imagery. The war damage included the formation of over 300 oil lakes, oil pollution and sand dune movement. Total damage area is over 5,400 square kilometers - 30 percent of Kuwait's total surface area.

  8. Climatic and lake temperature data for Wetland P1, Cottonwood Lake Area, Stutsman County, North Dakota, 1982-87

    USGS Publications Warehouse

    Parkhurst, Renee S.; Sturrock, A.M.; Rosenberry, D.O.; Winter, T.C.

    1995-01-01

    Research on the hydrology of Wetland P1 and the Cottonwood Lake Area includes the study of evaporation. Presented here in a graphical format are those data collected during the open-water seasons of 1982-87 that were needed for energy- budget and mass-transfer evaporation studies. The data include air temperatures, water surface and lake-bottom temperatures, windspeed, radiation, humidity, and precipitation. Data were collected at a raft station and two land stations.

  9. Assessment of Sediment Measurements in Lake Michigan as a Case Study: Implications for Monitoring and Modeling

    EPA Science Inventory

    Lake Michigan, the sixth largest freshwater lake in the world by surface area, was utilized as a water body for assessment within a case study. Field data collected at 116 sediment sampling sites throughout the lake in an intensive monitoring effort were utilized for assessment ...

  10. Great Lakes in January

    NASA Image and Video Library

    2017-12-08

    This image taken on January 13, 2015 from the Suomi NPP satellite's VIIRS instrument shows the Great Lakes and surrounding areas. The latest Great Lakes Surface Environmental Analysis (GLSEA) from the NOAA Great Lakes Environmental Research Laboratory shows total ice cover of 29.3% as of January 13th. Credit: NOAA/NASA/NPP Via NOAA Environmental Visualization Laboratory

  11. Salinity and hydrology of closed lakes

    USGS Publications Warehouse

    Langbein, Walter Basil

    1961-01-01

    Lakes without outlets, called closed lakes, are exclusively features of the arid and semiarid zones where annual evaporation exceeds rainfall. The number of closed lakes increases with aridity, so there are relatively few perennial closed lakes, but "dry" lakes that rarely contain water are numerous.Closed lakes fluctuate in level to a much greater degree than the open lakes of the humid zone, because variations in inflow can be compensated only by changes in surface area. Since the variability of inflow increases with aridity, it is possible to derive an approximate relationship for the coefficient of variation of lake area in terms of data on rates of evaporation, lake area, lake depth, and drainage area.The salinity of closed lakes is highly variable, ranging from less than 1 percent to over 25 percent by weight of salts. Some evidence suggests that the tonnage of salts in a lake solution is substantially less than the total input of salts into the lake over the period of existence of the closed lake. This evidence suggests further that the salts in a lake solution represent a kind of long-term balance between factors of gain and loss of salts from the solution.Possible mechanisms for the loss of salts dissolved in the lake include deposition in marginal bays, entrapment in sediments, and removal by wind. Transport of salt from the lake surface in wind spray is also a contributing, but seemingly not major, factor.The hypothesis of a long-term balance between input to and losses from the lake solution is checked by deriving a formula for the equilibrium concentration and comparing the results with the salinity data. The results indicate that the reported salinities seemingly can be explained in terms of their geometric properties and hydrologic environment.The time for accumulation of salts in the lake solution the ratio between mass of salts in the solution and the annual input may also be estimated from the geometric and hydrologic factors, in the absence of data on the salt content of the lake or of the inflow.

  12. Water quality of lakes Faith, Hope, Charity, and Lucien, 1971-79, in an area of residential development and highway construction at Maitland, Florida

    USGS Publications Warehouse

    German, Edward R.

    1983-01-01

    Lakes Faith, Hope, and Charity were sampled from April 1971 to June 1979 to monitor water quality before, during, and after construction of Maitland Boulevard and the Interstate Highway 4 interchange. Lake Lucien was added to the study in April 1975. Chemical quality of the lakes varies little in comparison with surface runoff, bulk precipitation, and the water in the surficial aquifer. Surface runoff supplied about 19 percent of the direct inflow to the lakes and contributed a total of about 2,000 pounds, per acre of lake surface, of dissolved solids from April 1971 to June 1979, while bulk precipitation contributed about 1,170 pounds per acre. Water quality in the lakes changed during the study, generally for the better. However, an infestation of elodea (Hydrilla verticillata), whose growth is not associated with water quality, developed in Lake Hope near the end of the study and has interfered with recreational use of the lake. (USGS)

  13. Rapid and highly variable warming of lake surface waters around the globe

    USGS Publications Warehouse

    O'Reilly, Catherine; Sharma, Sapna; Gray, Derek; Hampton, Stephanie; Read, Jordan S.; Rowley, Rex J.; Schneider, Philipp; Lenters, John D.; McIntyre, Peter B.; Kraemer, Benjamin M.; Weyhenmeyer, Gesa A.; Straile, Dietmar; Dong, Bo; Adrian, Rita; Allan, Mathew G.; Anneville, Orlane; Arvola, Lauri; Austin, Jay; Bailey, John L.; Baron, Jill S.; Brookes, Justin D; de Eyto, Elvira; Dokulil, Martin T.; Hamilton, David P.; Havens, Karl; Hetherington, Amy L.; Higgins, Scott N.; Hook, Simon; Izmest'eva, Lyubov R.; Jöhnk, Klaus D.; Kangur, Külli; Kasprzak, Peter; Kumagai, Michio; Kuusisto, Esko; Leshkevich, George; Livingstone, David M.; MacIntyre, Sally; May, Linda; Melack, John M.; Mueller-Navara, Doerthe C.; Naumenko, Mikhail; Noges, Peeter; Noges, Tiina; North, Ryan P.; Plisnier, Pierre-Denis; Rigosi, Anna; Rimmer, Alon; Rogora, Michela; Rudstam, Lars G.; Rusak, James A.; Salmaso, Nico; Samal, Nihar R.; Schindler, Daniel E.; Schladow, Geoffrey; Schmid, Martin; Schmidt, Silke R.; Silow, Eugene A.; Soylu, M. Evren; Teubner, Katrin; Verburg, Piet; Voutilainen, Ari; Watkinson, Andrew; Williamson, Craig E.; Zhang, Guoqing

    2015-01-01

    In this first worldwide synthesis of in situ and satellite-derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade−1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors—from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade−1) to ice-free lakes experiencing increases in air temperature and solar radiation (0.53°C decade−1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes.

  14. Charcoal deposition and redeposition in Elk Lake, Minnesota, USA

    USGS Publications Warehouse

    Platt, Bradbury J.

    1996-01-01

    Sedimentary charcoal, diatom and phytolith records of the past 1500 years at Elk Lake, Minnesota, in combination with sediment trap studies and a transect of surface sediment samples, document the mechanisms by which previously deposited charcoal is redeposited and finally buried in this lake. The frequent correspondence of high diatom concentrations and peaks of phytolith and charcoal fragments suggest that currents and turbulence related to lake circulation are responsible for winnowing charcoal and phytoliths from shallow water depositional sites to deeper areas of the lake. High diatom concentrations in the record relate to increased nutrient fluxes also supplied by circulation. Despite the fact that the watershed and area around Elk Lake has not been burned since AD 1922, charcoal continues to reach the profundal zone from littoral source areas in Elk Lake. The variable redeposition of within-lake charcoal requires evaluation before fire-history records can be related to global, regional or even local fire events.

  15. Geophysical investigation of sentinel lakes in Lake, Seminole, Orange, and Volusia Counties, Florida

    USGS Publications Warehouse

    Reich, Christopher; Flocks, James; Davis, Jeffrey

    2012-01-01

    This study was initiated in cooperation with the St. Johns River Water Management District (SJRWMD) to investigate groundwater and surface-water interaction in designated sentinel lakes in central Florida. Sentinel lakes are a SJRWMD established set of priority water bodies (lakes) for which minimum flows and levels (MFLs) are determined. Understanding both the structure and lithology beneath these lakes can ultimately lead to a better understanding of the MFLs and why water levels fluctuate in certain lakes more so than in other lakes. These sentinel lakes have become important water bodies to use as water-fluctuation indicators in the SJRWMD Minimum Flows and Levels program and will be used to define long-term hydrologic and ecologic performance measures. Geologic control on lake hydrology remains poorly understood in this study area. Therefore, the U.S. Geological Survey investigated 16 of the 21 water bodies on the SJRWMD priority list. Geologic information was obtained by the tandem use of high-resolution seismic profiling (HRSP) and direct-current (DC) resistivity profiling to isolate both the geologic framework (structure) and composition (lithology). Previous HRSP surveys from various lakes in the study area have been successful in identifying karst features, such as subsidence sinkholes. However, by using this method only, it is difficult to image highly irregular or chaotic surfaces, such as collapse sinkholes. Resistivity profiling was used to complement HRSP by detecting porosity change within fractured or collapsed structures and increase the ability to fully characterize the subsurface. Lake Saunders (Lake County) is an example of a lake composed of a series of north-south-trending sinkholes that have joined to form one lake body. HRSP shows surface depressions and deformation in the substrate. Resistivity data likewise show areas in the southern part of the lake where resistivity shifts abruptly from approximately 400 ohm meters (ohm-m) along the edges to approximately 12 ohm-m in the center. These well-defined areas may indicate a "ravel" zone of increased porosity or clay content. Within Lake Helen (Volusia County), a parallel set of seismic reflectors within a host of chaotic reflectors may represent fill within a large sinkhole. The feature extends to more than 50 meters (m) deep and contains very steep pinnacles within the center. Seismic data in Lake Helen are supported by high resistivity values from adjacent continuous resistivity profiles that show possible center collapse within the lake and infilling of sandy material. When used together, HRSP and DC resistivity techniques provide a composite image of structure and lithology to detect potential conduits for fluid flow.

  16. Possible Climatic Signal Recorded by Alkenone Distributions in Sediments from Freshwater and Saline Lakes on the Skarvsnes and Skallen Areas, Antarctica

    NASA Astrophysics Data System (ADS)

    Sawada, K.; Takeda, M.; Takano, Y.

    2014-12-01

    The distribution of long-chain (C37 - C39) alkenones in marine sediment has been well documented to record paleo-sea surface temperatures. The alkenones were also found in sediments of terrestrial saline lakes, and recently the calibrations of alkenone unsaturation indices - temperature have been established in continental areas. Furthermore, these biomarkers have been identified in lacustrine sediments on high-latitudinal terrestrial areas such as Greenland and Antarctica. In the present study, the alkenones were identified in the lacustrine sediment cores in freshwater (Lake Naga-ike) and saline lakes (Lake Suribati and Lake Funazoko) on the Skarvsnes, and a saline lake (Lake Skallen Oh-ike) on the Skallen, Antarctica. Here, we report that the alkenone distribution in the Antarctic lakes was examined as paleotemperature proxy. C37-C38 Tetra- and tri-unsaturated alkenones and C37 tetra- and tri-unsaturated alkenoates are identified in all sediment samples. The C37 di-unsaturated (C37:2) alkenones can be identified in sediments of surface layers (0-15 cm) of Lake Naga-ike and layers of 160-190 cm depth, in which age is ca. 3000 years BP by 14C dating, in Lake Skallen Ohike, and alkenone unsaturation index (UK37) is analyzed from these sediments. By using a calibration obtained from a culture strain Chrysotila lamellosa as reported by Nakamura et al. (2014), paleotemperatures are calculated to be 9.2-15ºC in surface sediments of Lake Naga-ike and 6.8-8.6ºC in Lake Skallen Oh-ike, respectively. The estimated temperatures are concordant with summer temperature of lake waters observed in Lake Naga-ike. Also, the highest concentrations of the alkenones and alkenoates are observed in deeper (older) sediment layers from Lake Naga-ikes, which has not been connected the ocean and intruded sea water. This implies that the alkenones are originated from indigenous biological organism(s) in Antarctic lake water. The class distributions (unsaturation ratios) of alkenones varied with core depths in Lake Naga-ike and Lake Suribati, whereas these are nearly constant with core depths in Lake Funazoko. These variations presumably depended on changes of climatic and environmental conditions in lake water. Thus, it is suggested that the alkenone proxies can be applicable for Antarctic climate changes.

  17. Integration of altimetric lake levels and GRACE gravimetry over Africa: Inferences for terrestrial water storage change 2003-2011

    NASA Astrophysics Data System (ADS)

    Moore, P.; Williams, S. D. P.

    2014-12-01

    Terrestrial water storage (TWS) change for 2003-2011 is estimated over Africa from GRACE gravimetric data. The signatures from change in water of the major lakes are removed by utilizing kernel functions with lake heights recovered from retracked ENVISAT satellite altimetry. In addition, the contribution of gravimetric change due to soil moisture and biomass is removed from the total GRACE signal by utilizing the GLDAS land surface model. The residual TWS time series, namely groundwater and the surface waters in rivers, wetlands, and small lakes, are investigated for trends and the seasonal cycle using linear regression. Typically, such analyses assume that the data are temporally uncorrelated but this has been shown to lead to erroneous inferences in related studies concerning the linear rate and acceleration. In this study, we utilize autocorrelation and investigate the appropriate stochastic model. The results show the proper distribution of TWS change and identify the spatial distribution of significant rates and accelerations. The effect of surface water in the major lakes is shown to contribute significantly to the trend and seasonal variation in TWS in the lake basin. Lake Volta, a managed reservoir in Ghana, is seen to have a contribution to the linear trend that is a factor of three greater than that of Lake Victoria despite having a surface area one-eighth of that of Lake Victoria. Analysis also shows the confidence levels of the deterministic trend and acceleration identifying areas where the signatures are most likely due to a physical deterministic cause and not simply stochastic variations.

  18. The volume and mean depth of Earth's lakes

    NASA Astrophysics Data System (ADS)

    Cael, B. B.; Heathcote, A. J.; Seekell, D. A.

    2017-01-01

    Global lake volume estimates are scarce, highly variable, and poorly documented. We developed a rigorous method for estimating global lake depth and volume based on the Hurst coefficient of Earth's surface, which provides a mechanistic connection between lake area and volume. Volume-area scaling based on the Hurst coefficient is accurate and consistent when applied to lake data sets spanning diverse regions. We applied these relationships to a global lake area census to estimate global lake volume and depth. The volume of Earth's lakes is 199,000 km3 (95% confidence interval 196,000-202,000 km3). This volume is in the range of historical estimates (166,000-280,000 km3), but the overall mean depth of 41.8 m (95% CI 41.2-42.4 m) is significantly lower than previous estimates (62-151 m). These results highlight and constrain the relative scarcity of lake waters in the hydrosphere and have implications for the role of lakes in global biogeochemical cycles.

  19. Faulting, damage, and intensity in the Canyondam earthquake of May 23, 2013

    USGS Publications Warehouse

    Chapman, K.; Gold, M.B.; Boatwright, John; Sipe, J.; Quitoriano, V.; Dreger, D.; Hardebeck, Jeanne

    2016-09-23

    On Thursday evening, May 23, 2013 (0347 May 24 UTC), a moment magnitude (Mw) = 5.7 earthquake occurred northeast of Canyondam, California. A two-person team of U.S. Geological Survey scientists went to the area to search for surface rupture and to canvass damage in the communities around Lake Almanor. While the causative fault had not been identified at the time of the field survey, surface rupture was expected to have occurred just south of Lake Almanor, approximately 2–4 kilometers south of the epicenter. No surface rupture was discovered. Felt intensity among the communities around Lake Almanor appeared to vary significantly. Lake Almanor West (LAW), Lake Almanor Country Club (LACC), and Hamilton Branch (HB) experienced Modified Mercalli Intensity (MMI) ≥7, whereas other communities around the lake experienced MMI ≤6; the maximum observed intensity was MMI 8, in LAW. Damage in the high intensity areas consisted of broken and collapsed chimneys, ruptured pipes, and some damage to foundations and to structural elements within houses. Although this shaking damage is not usually expected for an Mw 5.7 earthquake, the intensities at Lake Almanor Country Club correlate with the peak ground acceleration (38 percent g) and peak ground velocity (30 centimeters per second) recorded by the California Strong Motion Instrumentation Program accelerometer located at the nearby Lake Almanor Fire Station. The intensity distribution for the three hardest hit areas (LAW, LACC, and HB) appears to increase as the azimuth from epicenter to the intensity sites approaches the fault strike. The small communities of Almanor and Prattville on the southwestern shore of Lake Almanor experienced somewhat lower intensities. The town of Canyondam experienced a lower intensity as well, despite its location up-dip of the earthquake rupture. This report contains information on the earthquake itself, the search for surface rupture, and the damage we observed and compiled from other sources. 

  20. Geochemical evolution of groundwater in the Mud Lake area, eastern Idaho, USA

    USGS Publications Warehouse

    Rattray, Gordon W.

    2015-01-01

    Groundwater with elevated dissolved-solids concentrations—containing large concentrations of chloride, sodium, sulfate, and calcium—is present in the Mud Lake area of Eastern Idaho. The source of these solutes is unknown; however, an understanding of the geochemical sources and processes controlling their presence in groundwater in the Mud Lake area is needed to better understand the geochemical sources and processes controlling the water quality of groundwater at the Idaho National Laboratory. The geochemical sources and processes controlling the water quality of groundwater in the Mud Lake area were determined by investigating the geology, hydrology, land use, and groundwater geochemistry in the Mud Lake area, proposing sources for solutes, and testing the proposed sources through geochemical modeling with PHREEQC. Modeling indicated that sources of water to the eastern Snake River Plain aquifer were groundwater from the Beaverhead Mountains and the Camas Creek drainage basin; surface water from Medicine Lodge and Camas Creeks, Mud Lake, and irrigation water; and upward flow of geothermal water from beneath the aquifer. Mixing of groundwater with surface water or other groundwater occurred throughout the aquifer. Carbonate reactions, silicate weathering, and dissolution of evaporite minerals and fertilizer explain most of the changes in chemistry in the aquifer. Redox reactions, cation exchange, and evaporation were locally important. The source of large concentrations of chloride, sodium, sulfate, and calcium was evaporite deposits in the unsaturated zone associated with Pleistocene Lake Terreton. Large amounts of chloride, sodium, sulfate, and calcium are added to groundwater from irrigation water infiltrating through lake bed sediments containing evaporite deposits and the resultant dissolution of gypsum, halite, sylvite, and bischofite.

  1. Climatic data for the Cottonwood Lake area, Stutsman County, North Dakota 1982

    USGS Publications Warehouse

    Sturrock, A.M.; Hanson, B.A.; Scarborough, J.L.; Winter, T.C.

    1986-01-01

    Research on the hydrology of the Cottonwood Lake area, Stutsman County, North Dakota, includes study of evaporation. Presented here are those climatic data needed for energy-budget and mass-transfer evaporation studies, including: water-surface temperature, sediment temperature dry-bulb and wet-bulb air temperatures, vapor pressure at and above the water surface, wind speed, and short- and long-wave radiation. Data were collected at raft and land stations.

  2. Climatic data for the Cottonwood Lake area, Stutsman County, North Dakota, 1983

    USGS Publications Warehouse

    Sturrock, A.M.; Hanson, B.A.; Scarborough, J.L.; Winter, T.C.

    1987-01-01

    Research on the hydrology of the Cottonwood Lake area, Stutsman County, North Dakota, includes study of evaporation. Climatic data needed for energy-budget and mass-transfer evaporation studies that were collected during 1983 include water-surface temperature, sediment temperature, dry-bulb and wet-bulb air temperature, vapor pressure at and above the water surface, wind speed, and short-and long-wave radiation. Data are collected at raft and land stations. (USGS)

  3. Over-wintering of Supraglacial Lakes on the Greenland Ice Sheet from Sentinel-1 and Landsat-8 Data

    NASA Astrophysics Data System (ADS)

    Benedek, C. L.; Tedesco, M.

    2015-12-01

    Supra-glacial lakes on the GrIS have become a focus of research relating to the contribution of the GrIS to sea level rise. Lakes have been observed to appear during the summer melt season. Though it appears that the quantity of water collected on the surface is small, it is thought that the fracture and drainage of these lakes delivers significant pulses of water to the ice sheet bed, influencing the dynamic movement of glaciers towards the sea. The pattern of this transport mechanism may be a central driver of its influence over dynamic losses, as the flow of the viscoelastic ice sheet will differ if the water is delivered in a short pulse or a slower constant supply. A number of studies have catalogued the traits of lakes with an aim to quantify lake areas, depths, and timing of formation and cessation using visible and near infrared remote sensing instruments mostly focused on the summer melt season. Little is known about the behaviour of the surface lakes over the winter. A recent examination of the over-wintering of surface lakes has been conducted by Koenig et al. [2015] using airborne radar. While the study is extensive in area covered, it is limited in its temporal resolution by the availability of Operation IceBridge data, typically at one pass per year. This study seeks to observe the development of lakes over the winter period. Sentinel-1A radar images are used to track the presence of surface lakes and their variation in three study sites on the Greenland ice sheet. The sites are as follows: upstream of Ryder glacier, upstream of Petermann glacier, and upstream of Jakobshavn glacier. Water masks are created based on summer Landsat-8 images following NDWIice and then compared to Sentinel images at monthly temporal resolution through the winter of 2014-2015. These radar images show persistence of liquid water through the winter in agreement with previous research as well as variation in the buried lake area over the span of the year studied.

  4. Hydrology of Central Florida Lakes - A Primer

    USGS Publications Warehouse

    Schiffer, Donna M.

    1998-01-01

    INTRODUCTION Lakes are among the most valued natural resources of central Florida. The landscape of central Florida is riddled with lakeswhen viewed from the air, it almost seems there is more water than land. Florida has more naturally formed lakes than other southeastern States, where many lakes are created by building dams across streams. The abundance of lakes on the Florida peninsula is a result of the geology and geologic history of the State. An estimated 7,800 lakes in Florida are greater than 1 acre in surface area. Of these, 35 percent are located in just four counties (fig. 1): Lake, Orange, Osceola, and Polk (Hughes, 1974b). Lakes add to the aesthetic and commercial value of the area and are used by many residents and visitors for fishing, boating, swimming, and other types of outdoor recreation. Lakes also are used for other purposes such as irrigation, flood control, water supply, and navigation. Residents and visitors commonly ask questions such as Whyare there so many lakes here?, Why is my lake drying up (or flooding)?, or Is my lake spring-fed? These questions indicate that the basic hydrology of lakes and the interaction of lakes with ground water and surface water are not well understood by the general population. Because of the importance of lakes to residents of central Florida and the many questions and misconceptions about lakes, this primer was prepared by the U.S. Geological Survey (USGS) in cooperation with the St. Johns River Water Management District and the South Florida Water Management District. The USGS has been collecting hydrologic data in central Florida since the 1920s, obtaining valuable information that has been used to better understand the hydrology of the water resources of central Florida, including lakes. In addition to data collection, as of 1994, the USGS had published 66 reports and maps on central Florida lakes (Garcia and Hoy, 1995). The main purpose of this primer is to describe the hydrology of lakes in central Florida, the interactions between lakes and ground- and surface-waters, and to describe how these interactions affect lake water levels. Included are descriptions of the basic geology and geomorphology of central Florida, origins of central Florida lakes, factors that affect lake water levels, lake water quality, and common methods of improving water quality. The geographic area discussed in this primer is approximate (fig. 1) and includes west and east-central Florida, extending from the Gulf of Mexico to the Atlantic Ocean coastlines, northward into Marion, Putnam, and Flagler Counties, and southward to Lake Okeechobee. The information presented here was obtained from the many publications available on lakes in central Florida, as well as from publications on Florida geology, hydrology, and primers on ground water, surface water, and water quality. Many publications are available that provide more detailed information on lake water quality, and this primer is not intended as an extensive treatise on that subject. The reader is referred to the reference section of this primer for sources of more detailed information on lake water quality. Lakes discussed in this report are identified in figure 2. Technical terms used in the report are shown in bold italics and are defined in the glossary. The classification of some water bodies as lakes is highly subjective. What one individual considers a lake another might consider a pond. Generally, any water- filled depression or group of depressions in the land surface could be considered a lake. Lakes differ from swamps or wetlands in the type and amount of vegetation, water depth, and some water-quality characteristics. Lakes typically have emergent vegetation along the shoreline with a large expanse of open water in the center. Swamps or wetlands, on the other hand, are characterized by a water surface interrupted by the emergence of many varieties of plant life, from saw grasses to cypress trees. Lakes may be na

  5. Geologic map database of the El Mirage Lake area, San Bernardino and Los Angeles Counties, California

    USGS Publications Warehouse

    Miller, David M.; Bedford, David R.

    2000-01-01

    This geologic map database for the El Mirage Lake area describes geologic materials for the dry lake, parts of the adjacent Shadow Mountains and Adobe Mountain, and much of the piedmont extending south from the lake upward toward the San Gabriel Mountains. This area lies within the western Mojave Desert of San Bernardino and Los Angeles Counties, southeastern California. The area is traversed by a few paved highways that service the community of El Mirage, and by numerous dirt roads that lead to outlying properties. An off-highway vehicle area established by the Bureau of Land Management encompasses the dry lake and much of the land north and east of the lake. The physiography of the area consists of the dry lake, flanking mud and sand flats and alluvial piedmonts, and a few sharp craggy mountains. This digital geologic map database, intended for use at 1:24,000-scale, describes and portrays the rock units and surficial deposits of the El Mirage Lake area. The map database was prepared to aid in a water-resource assessment of the area by providing surface geologic information with which deepergroundwater-bearing units may be understood. The area mapped covers the Shadow Mountains SE and parts of the Shadow Mountains, Adobe Mountain, and El Mirage 7.5-minute quadrangles. The map includes detailed geology of surface and bedrock deposits, which represent a significant update from previous bedrock geologic maps by Dibblee (1960) and Troxel and Gunderson (1970), and the surficial geologic map of Ponti and Burke (1980); it incorporates a fringe of the detailed bedrock mapping in the Shadow Mountains by Martin (1992). The map data were assembled as a digital database using ARC/INFO to enable wider applications than traditional paper-product geologic maps and to provide for efficient meshing with other digital data bases prepared by the U.S. Geological Survey's Southern California Areal Mapping Project.

  6. Aquatic balance in Vegoritis Lake, West Macedonia, Greece, relating to lignite mining works in the area

    NASA Astrophysics Data System (ADS)

    Dimitrakopoulos, D.; Grigorakou, E.; Koumantakis, J.

    2003-04-01

    Vegoritis Lake, which is located at Vegoritis closed Basin in West Macedonia, Greece, is the biggest lake in Greece. In 1994 the area of the lake was 35 Km2 with maximum depth 42 m at the northwestern part of the lake. It is the final receiving body of the surface runoff of the hydrological basin. Moreover, it is the surficial appearance of an enormous and not well-known karstic aquifer. Being a closed hydrological basin any interference in surface or groundwater conditions in every part of its area affects the level of the lake. The level of the lake in 1900 was 525 masl, in 1942 was 542 masl reaching the higher level of 543 masl in 1956. The increase of the level of the lake was due to the drainage of Ptolemais (Sarigiol) swamp through Soulou drain ditches that transfer the water in the lake. Since then, a continuous drawdown took place with small periods of rising of water level. Today, the level of the lake is declined in a smaller rate having reached the level of 510 masl. Water coming from the lake has been used in the past, and in some cases still does, for agricultural, industrial and domestic use, for hydropower generation and for the cooling system of power plants. Moreover, P.P.C. (Public Power Corporation of Greece) develops an intense activity in the area with the exploitation of the lignite deposits of the basin and power generation in several Power Plants. Few years ago significant quantities from Vegoritis Lake were used for hydro power of Agras Power Plant. With the elaboration of the existent data (water level measurements, recharge, discharge) the connection between the lowering of the surface of the lake and the subtracted quantities through the Arnissa Tunel the first years of its use, is obvious. The last twenty years the condition has change. Outflow through the Arnissa Tunnel for hydropower has stopped. The continued lowering of the level of the lake is caused, mainly, by overexploitation due to the intense increase of the irrigating land. The dewatering of the aquifers for the protection of the lignite mine seems to have an insignificant influence on the aquatic balance, as the water is discharged again into the streams and rivers of the closed basin.

  7. Drainage areas in the Vermillion River basin in eastern South Dakota

    USGS Publications Warehouse

    Benson, Rick D.; Freese, M.D.; Amundson, Frank D.

    1988-01-01

    Above-normal precipitation in the northern portion of the Vermillion River basin from 1982 through 1987 caused substantial rises in lake levels in the Lake Thompson chain of lakes, resulting in discharge from Lake Thompson to the East Fork Vermillion River. Prior to 1986, the Lake Thompson chain of lakes was thought to be a noncontributing portion of the Vermillion River basin. To better understand surface drainage, the map delineates all named stream basins, and all unnamed basins larger than approximately 10 sq mi within the Vermillion River basin in South Dakota and lists by stream name the area of each basin. Stream drainage basins were delineated by visual interpretation of contour information of U.S. Geological Survey 7 1/2 minute topographic maps. Two tables list areas of drainage basins and reaches, as well as drainage areas above gaging stations. (USGS)

  8. Use of thermal inertia determined by HCMM to predict nocturnal cold prone areas in Florida. [The Everglades agricultural area, Lake Okeechobee, and the Suwanee River basin

    NASA Technical Reports Server (NTRS)

    Allen, L. H., Jr. (Principal Investigator); Chen, E.; Martsolf, J. D.; Jones, P. H.

    1981-01-01

    Transparencies, prints, and computer compatible tapes of temperature differential and thermal inertia for the winter of 1978 to 1979 were obtained. Thermal inertial differences in the South Florida depicted include: drained organic soils of the Everglades agricultural area, undrained organic soils of the managed water conservation areas of the South Florida water management district, the urbanized area around Miami, Lake Okeechobee, and the mineral soil west of the Everglades agricultural area. The range of wetlands and uplands conditions within the Suwanee River basin was also identified. It is shown that the combination of wetlands uplands surface features of Florida yield a wide range of surface temperatures related to wetness of the surface features.

  9. 78 FR 76781 - Proposed Modification of Class B Airspace; Salt Lake City, UT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ... City, UT AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking... City Class B airspace area by raising the floor of a small portion of Class B airspace between the Salt Lake City Class B surface area and the Hill Air Force Base (AFB) Class D airspace area. This action...

  10. Radiative temperature measurements at Kupaianaha lava lake, Kilauea Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    Flynn, Luke P.; Mouginis-Mark, Peter J.; Gradie, Jonathan C.; Lucey, Paul G.

    1993-01-01

    The radiative temperature of the surface of Kupaianaha lava lake is computed using field spectroradiometer data. Observations were made during periods of active overturning. The lake surface exhibits three stages of activity. Magma fountaining and overturning events characterize stage 1, which exhibits the hottest crustal temperatures and the largest fractional hot areas. Rifting events between plates of crust mark stage 2; crustal temperatures in this stage are between 100 C and 340 C, and fractional hot areas are at least an order of magnitude smaller than those in stage 1. Stage 3 is characterized by quiescent periods when the lake is covered by a thick crust. This stage dominates the activity of the lake more than 90 percent of the time. The results of this study are relevant for satellite and airborne measurement of the thermal characteristics of active volcanoes, and indicate that the thermal output of a lava lake varies on a time scale of seconds to minutes.

  11. Satellite observation of lake ice as a climate indicator - Initial results from statewide monitoring in Wisconsin

    NASA Technical Reports Server (NTRS)

    Wynne, Randolph H.; Lillesand, Thomas M.

    1993-01-01

    The research reported herein focused on the general hypothesis that satellite remote sensing of large-area, long-term trends in lake ice phenology (formation and breakup) is a robust, integrated measure of regional and global climate change. To validate this hypothesis, we explored the use of data from the Advanced Very High Resolution Radiometer (AVHRR) to discriminate the presence and extent of lake ice during the winter of 1990-1991 on the 45 lakes and reservoirs in Wisconsin with a surface area greater than 1,000 hectares. Our results suggest both the feasibility of using the AVHRR to determine the date of lake ice breakup as well as the strong correlation (R= -0.87) of the date so derived with local surface-based temperature measurements. These results suggest the potential of using current and archival satellite data to monitor changes in the date of lake ice breakup as a means of detecting regional 'signals' of greenhouse warming.

  12. Lake acidification in the Adirondack Mountains of New York causes and consequences

    Treesearch

    Carl L. Schofield

    1976-01-01

    Current and historic geographic distributions of acidity in Adirondack lakes were examined in relation to regional edaphic, climatic, and physiographic features. Acid conditions are currently predominant in high elevation drainage lakes having small watershed/surface area ratios. Comparable levels of acidity were found only in small seepage lakes and bog ponds during...

  13. Evolution of supra-glacial lakes across the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Sundal, A. V.; Shepherd, A.; Nienow, P.; Hanna, E.; Palmer, S.; Huybrechts, P.

    2009-04-01

    We have used 268 cloud-free Moderate-resolution Imaging Spectroradiometer (MODIS) images spanning the 2003 and 2005-2007 melt seasons to study the seasonal evolution of supra-glacial lakes in three different regions of the Greenland Ice Sheet. Lake area estimates were obtained by developing an automated classification method for their identification based on 250 m resolution MODIS surface reflectance observations. Widespread supra-glacial lake formation and drainage is observed across the ice sheet, with a 2-3 weeks delay in the evolution of total supra-glacial lake area in the northern areas compared to the south-west. The onset of lake growth varies by up to one month inter-annually, and lakes form and drain at progressively higher altitudes during the melt season. A correlation was found between the annual peak in total lake area and modelled annual runoff across all study areas. Our results indicate that, in a future warmer climate (Meehl et al., 2007), Greenland supra-glacial lakes can be expected to form at higher altitudes and over a longer time period than is presently the case, expanding the area and time period over which connections between the ice sheet surface and base may be established (Das et al., 2008) with potential consequences for ice sheet discharge (Zwally et al., 2002). Das, S., Joughin, M., Behn, M., Howat, I., King, M., Lizarralde, D., & Bhatia, M. (2008). Fracture propagation to the base of the Greenland Ice Sheet during supra-glacial lake drainage. Science, 5877, 778-781. Meehl, G.A., Stocker, T.F., Collins W.D., Friedlingstein, P., Gaye, A.T., Gregory, J.M., Kitoh, A., Knutti, R., Murphy, J.M., Noda, A., Raper, S.C.B., Watterson, I.G., Weaver, A.J. & Zhao, Z.C. (2007). Global Climate Projections. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Zwally, H.J., Abdalati, W., Herring, T., Larson, K., Saba, J. & Steffen, K. (2002). Surface Melt-Induced Acceleration of Greenland Ice-Sheet Flow. Science, 297, 218-221.

  14. The influence of a land-lake surface discontinuity on the convective boundary layer flow

    NASA Astrophysics Data System (ADS)

    Martinez, Daniel; Bange, Jens; Lang, Andreas

    2013-04-01

    The current work addresses the effects of surface discontinuities into the atmospheric boundary layer (ABL) with free convection using data collected during the STINHO 2002 and LITFASS 2003 experimental campaigns. These field experiments were performed during two consecutive summers in the area of Branderburg, Germany, over a heterogeneous area located around the Meteorological Observatory Lindenberg (MOL) of the German Weather Service (DWD). The terrain can be considered flat with areas of pine forests and agricultural fields, where lakes and villages are irregularly distributed to form a heterogeneous landscape representative of central Europe. Specific measurements collected by the helicopter-borne turbulence probe Helipod were selected to focus on the water-land surface transition over lake Scharnuetzel, a small-scale lake of 10 km x 2 km length scale. Four flights with a similar pattern were performed, with heights that range from 70 to 900 m above ground level (a.g.l.), in order to characterise the vertical extent of the surface discontinuity influence to the turbulent flow. The concepts of blending height and internal boundary layer (IBL) have been applied to the experimental data as a theoretical background. In general, the presence of the lake is reflected in the statistical second-order moments of the time series collected below 100 m a.g.l., specially for those time series related with the potential temperature. However, none of the parametrizations found in the literature related with the blending height or IBL seem to be appropriate for this special case, where a small-scale lake is the responsible of the surface heterogeneity. An analysis of the downstream propagation of the IBL depth shows that it depends on (i) the air stability downwind of the surface discontinuity and (ii) the wind speed in the surface layer. These preliminary results should be confirmed with the performance of new experiments.

  15. Tracking four-decade inundation changes with multi-temporal satellite images in China's largest freshwater lake

    NASA Astrophysics Data System (ADS)

    Wu, Guiping

    2017-04-01

    Poyang Lake is the largest freshwater lake in China. The lake has undergone remarkable spatio-temporal changes in both short- and long-term scales since 1970s, resulting in significant hydrological, ecological and economic consequences. Remote sensing techniques have advantages for large-scale studies, by offering images at different spatial and spectral resolutions. However, due to technical difficulties, no single satellite sensor can meet the needs for high spatio-temporal resolution required for such monitoring. In this study, using Landsat Thematic Mapper (TM) and Moderate Resolution Imaging Spectroradiometer (MODIS) images collected between 1973 and 2012, we documented and investigated the short- and long-term characteristics of lake inundation based on Normalized Difference Water Index (NDWI). First, we presented a novel downscaling method based on the NDWI statistical regression algorithm to generate small-scale resolution inundation map (30m) from coarse MODIS data (500m). The downscaling is a linear calibration of the NDWI index from MODIS imagery to Landsat imagery, which is based on the assumption that the relationships between fine resolution and coarse resolution are invariable. Second, Tupu analysis method was further performed to explore the spatial-temporal distribution and changing processes of lake inundation based on downscaling inundation maps. Then, a defined water variation rate (WVR) and inundation frequency (IF) indicator was used to reveal seasonal water surface submersion/exposure processes of lake expansion and shrinkage in different zones. Finally, mathematical statistics methods were utilized to explore the possible driving mechanisms of the revealed change patterns with meteorological data and hydrological data. The results show that, there is a high correlation (mean absolute error of 3.95% and an R2 of 0.97) between the MODIS- and Landsat-derived water surface areas in Poyang Lake. Over the past 40 years, a declining trend to a certain extent for the Poyang Lake's area could be detected. The lake surface displayed comparatively low values ( 2000 km2) in wet periods of 1980, 2006, 2009 and 2011, corresponding to severe hydrological droughts in the lake. In addition, the water surface variation in Poyang Lake had a typical seasonal behavior. It mostly followed a unimodal cycle with area peaks appeared in the wet season. The earliest beginning of the inundation cycle was emerged in 2000 and the latest in 2006. In general, the change of lake area is a synthetic result of climate change, land-cover change and construction of dykes. Our findings should be valuable to a comprehensive understanding of Poyang Lake's decadal and seasonal variation, which is critical for flood/drought prevention, land use planning and lake ecological conservation.

  16. Integrating limnological characteristics of high mountain lakes into the landscape of a natural area

    USGS Publications Warehouse

    Larson, Gary L.; Wones, A.; McIntire, C.D.; Samora, B.

    1994-01-01

    A general conceptual watershed-lake model of the complex interactions among climatic conditions, watershed location and characteristics, lake morphology, and fish predation was used to evaluate limnological characteristics of high mountain lakes. Our main hypothesis was that decreasing elevation in mountainous terrain corresponds to an increase in diversity of watershed size and lake area, depth, temperature, nutrient concentrations, and productivity. A second hypothesis was that watershed location and aspect relative to climatic gradients within mountainous terrain influences the limnological characteristics of the lakes. We evaluated these hypotheses by examining watershed location, aspect and size; lake morphology; water quality; and phytoplankton and zooplankton community characteristics among high mountain forest and subalpine lakes in Mount Rainier National Park. Although many of the comparisons between all forest and subalpine lakes were statistically insignificant, the results revealed trends that were consistent with our hypotheses. The forest lake group included more lakes with larger watersheds, larger surface areas, greater depths, higher concentrations of nutrients, and higher algal biovolumes than did the group of subalpine lakes. Deep lakes, which were mostly of the forest lake type, exhibited thermal stratification and relatively high values of some of the water-quality variables near the lake bottoms. However, the highest near-surface water temperatures and phytoplankton densities and the taxonomic structures of the phytoplankton and zooplankton assemblages were more closely related to geographical location, which corresponded to a west-east climate gradient in the park, than to lake type. Some crustacean and rotifer taxa, however, were limited in distribution by lake type. Fish predation did not appear to play an important role in the structure of the crustacean zooplankton communities at the genus level with the exception of Mowich Lake, where crustacean taxa were absent from the zooplankton community. This was the only lake inhabited by a true zooplanktivourous species of fish.

  17. Diffuse CO2 fluxes from Santiago and Congro volcanic lakes (São Miguel, Azores archipelago)

    NASA Astrophysics Data System (ADS)

    Andrade, César; Cruz, José; Viveiros, Fátima; Branco, Rafael

    2017-04-01

    Diffuse CO2 degassing occurring in Santiago and Congro lakes, both located in depressions associated to maars from São Miguel Island (Azores, Portugal), was studied through detailed flux measurements. Four sampling campaigns were developed between 2013 and 2016 in each water body, split by the cold and wet seasons. São Miguel has an area of 744.6 km2, being the largest island of the archipelago. The geology of the island is dominated by three quiescent central volcanoes (Sete Cidades, Fogo and Furnas), linked by volcanic fissural zones (Picos and Congro Fissural Volcanic systems). The oldest volcanic systems of the island are located in its eastern part (Povoação-Nordeste). Santiago lake, with a surface area of 0.26 km2 and a depth of 30.5 m, is located inside a maar crater in the Sete Cidades volcano at an altitude of 355 m. The watershed of the lake has an area of 0.97 km2 and a surface flow estimated as 1.54x10 m3/a. A total of 1612 CO2 flux measurements using the accumulation chamber method were made at Santiago lake, 253 in the first campaign (November 2013), and 462, 475 and 422 in the three other campaigns, respectively, in April 2014, September 2016 and December 2016. The total CO2 flux estimated for this lake varies between 0.4 t d-1 and 0.59 t d-1, for the surveys performed, respectively, in November 2013 and September 2016; higher CO2 outputs of 1.57 and 5.87 t d-1 were calculated for the surveys carried out in April 2014 and December 2016. These higher CO2 emissions were associated with a period without water column stratification. Similarly to Santiago lake, Congro lake is located inside a maar, in the Congro Fissural Volcanic system, and has a surface area of 0.04 km2 with 18.5 m depth and a storage of about 2.4x105 m3/a. The lake, located at an altitude of 420 m, is fed by a watershed with an area of 0.33 km2 and a runoff estimated as about 8x104 m3/a. In Congro lake a total of 713 CO2 flux measurements were performed during four surveys from November 2013 to February 2016. The CO2 flux output was estimated as ranging between 0.06 t d-1 and 0.31 t d-1; the lower CO2 emission occurred in July 2015 and should reflect the stratification of the water column that prevents the CO2 flux release at the lake surface. Considering both volcanic lakes, the mean CO2 emissions, standardized per area, in the cold season were ˜14.9 t km-2 d-1 and ˜7.1 t km-2 d-1, respectively, for Santiago and Congro lakes. During summer period, CO2 emissions were lower in both lakes (˜1.9 t km-2 d-1 and ˜4.1 t km-2 d-1 for Santiago and Congro, correspondingly), what is explained by the lake stratification. Due to the organic processes that occur in the lakes, the CO2 emission is mostly associated to a biogenic origin, but a volcanic influence cannot be excluded and further research using carbon isotopic data is crucial to discriminate the CO2 sources. Key words: volcanic lakes, CO2 flux, maars, São Miguel Island

  18. Lake Enriquillo, Dominican Republic

    NASA Image and Video Library

    2017-08-15

    Lake Enriquillo is a hypersaline lake in the Dominican Republic. In 2004, the lake covered an area of 164 square kilometers; by 2011, it had doubled in size and grown to 350 km2, inundating farmland and homes. Various reasons for the flooding include increases in rainfall; increase of sediments going into the lake, raising the lakebed; and milder temperatures, reducing surface evaporation. The lake is home to the largest population of American crocodiles in the Caribbean. The images were acquired October 26, 2003 and June 10, 2017, cover an area of 22.7 by 45.4 km, and are located at 18.5 degrees north, 71.6 degrees west. An image of Lake Enriquillo taken in 2003 is available at https://photojournal.jpl.nasa.gov/catalog/PIA21815

  19. Computing Evaporation Using Meteorological Data for Hydrological Budget of Lake Wapalanne in NJ School of Conservation

    NASA Astrophysics Data System (ADS)

    Jordan, J. J.; Barrett, K. R.; Galster, J. C.; Ophori, D. U.; Flores, D.; Kelly, S. A.; Lutey, A. M.

    2011-12-01

    Lake Wapalanne is small manmade lake about 5.4 hectares in northwest New Jersey in the Highlands Physiographic province within permanently protected land. The lake's surrounding area consists of forested vegetation and is relatively unoccupied which minimizes human influence. The lake's small size, minimal external influence, geographic isolation, and protected status provide an optimal research environment to record meteorological data used in calculation of potential evaporation. Between July 7h and August 3rd meteorological data was collected from a professional weather station placed on an island directly in the center of Lake Wapalanne. The Vantage Pro2 weather station provided accurate readings of temperate, humidity, wind-speed and direction, precipitation, and atmospheric pressure. A bathometric survey of the lake was conducted to determine the surface area with variations in depth of the lake's water level. Using the collected weather station data, a rate of potential evaporation was determined with several evaporation equations. A quantified volume was then derived from the rate and surface area of the lake. Using small scale evaporation measurements of known volumes of water within small pans placed in the lake water and National Oceanic and Atmospheric Administration evaporation stations near the experiment site, a comparison and validation of the calculated potential evaporation accuracy and regional evaporation is achieved. This three year study is part of an ongoing NSF Research Experience for Undergraduates (REU) project that encompasses additional topics of lake research; see abstract from Kelly et al. AGU 2011 for more information on the lake's hydrologic budget. The results and methods of this study will be of use in future forecasting and baseline measurements of hydrologic budgets for lakes and reservoirs within regional proximity, which provide drinking water to over five million people in the State of New Jersey.

  20. Estimating the volume and age of water stored in global lakes using a geo-statistical approach

    PubMed Central

    Messager, Mathis Loïc; Lehner, Bernhard; Grill, Günther; Nedeva, Irena; Schmitt, Oliver

    2016-01-01

    Lakes are key components of biogeochemical and ecological processes, thus knowledge about their distribution, volume and residence time is crucial in understanding their properties and interactions within the Earth system. However, global information is scarce and inconsistent across spatial scales and regions. Here we develop a geo-statistical model to estimate the volume of global lakes with a surface area of at least 10 ha based on the surrounding terrain information. Our spatially resolved database shows 1.42 million individual polygons of natural lakes with a total surface area of 2.67 × 106 km2 (1.8% of global land area), a total shoreline length of 7.2 × 106 km (about four times longer than the world's ocean coastline) and a total volume of 181.9 × 103 km3 (0.8% of total global non-frozen terrestrial water stocks). We also compute mean and median hydraulic residence times for all lakes to be 1,834 days and 456 days, respectively. PMID:27976671

  1. Detection of Supra-Glacial Lakes on the Greenland Ice Sheet Using MODIS Images

    NASA Astrophysics Data System (ADS)

    Verin, Gauthier; Picard, Ghislain; Libois, Quentin; Gillet-Chaulet, Fabien; Roux, Antoine

    2015-04-01

    During melt season, supra-glacial lakes form on the margins of the Greenland ice sheet. Because of their size exceeding several kilometers, and their concentration, they affect surface albedo leading to an amplification of the regional melt. Furthermore, they foster hydro-fracturing that propagate liquid water to the bedrock and therefore enhance the basal lubrication which may affect the ice motion. It is known that Greenland ice sheet has strongly responded to recent global warming. As air temperature increases, melt duration and melt intensity increase and surface melt area extends further inland. These recent changes may play an important role in the mass balance of the Greenland ice sheet. In this context, it is essential to better monitor and understand supra-glacial spatio-temporal dynamics in order to better assess future sea level rise. In this study MODIS (Moderate Resolution Imaging Spectroradiometer) images have been used to detect supra-glacial lakes. The observation site is located on the West margin of the ice sheet, between 65°N and 70°N where the concentration of lake is maximum. The detection is performed by a fully automatic algorithm using images processing techniques introduced by Liang et al. (2012) which can be summarized in three steps: the selection of usable MODIS images, mainly we exclude images with too many clouds. The detection of lake and the automatic correction of false detections. This algorithm is capable to tag each individual lake allowing a survey of all lake geometrical properties over the entire melt season. We observed a large population of supra-glacial lakes over 14 melt seasons, from 2000 to 2013 on an extended area of 70.000 km2. In average, lakes are observed from June 9 ± 8.7 days to September 13 ± 13.9 days, and reach a maximum total area of 699 km2 ± 146 km2. As the melt season progresses, lakes form higher in altitude up to 1800 m above sea level. Results show a very strong inter-annual variability in term of date of melt and freeze up onset, melt season duration, maximum total surface area and number of lakes. As it has already been noticed, we observed a strong spatial persistence. Lakes tend to form at the same place for several years, probably because of the ice sheet surface topography. In order to investigate possible links with climatic parameters we calculated positive degree day (PDD). The main result of this comparison is a strong correlation between melt intensity and the altitude of lakes. During warmer summer, lakes form higher in altitude and consequently the extent of melting increase. Recent studies showed this trend is likely to continue and to increase in the years to come.

  2. Lake Powell

    NASA Image and Video Library

    2007-09-20

    The white ring around Lake Powell tells the story. The surface is down 98 feet. This is critical, because Powell, Lake Mead, and other lakes along the Colorado River provide water for millions of people in five states. We are in the eighth year of a drought on the Colorado River. This year was the driest year ever reported in Southern California, and there is a severe drought in Northern California, down to less than 30-percent of snow pack. This ASTER image of part of Lake Powell was acquired in 2001. The gray area depicts the shrunken, reduced 2007 lake extent compared to the extended, larger black area in 2001. The image covers an area of 24 x 30 km, and is centered near 37.1 degrees north latitude, 111.3 degrees west longitude. This image from NASA Terra satellite. http://photojournal.jpl.nasa.gov/catalog/PIA10614

  3. Distribution of sediment measurements in Lake Michigan as a case study: Implications for estimating sediment and water interactions in eutrophication and bioaccumulation models

    EPA Science Inventory

    Lake Michigan, the sixth largest freshwater lake in the world by surface area, was utilized as a water body for assessment within a case study. Field data collected at 116 sampling sites throughout the lake in an intensive monitoring effort were utilized for evaluation of the di...

  4. Groundwater levels, geochemistry, and water budget of the Tsala Apopka Lake system, west-central Florida, 2004–12

    USGS Publications Warehouse

    McBride, W. Scott; Metz, Patricia A.; Ryan, Patrick J.; Fulkerson, Mark; Downing, Harry C.

    2017-12-18

    Tsala Apopka Lake is a complex system of lakes and wetlands, with intervening uplands, located in Citrus County in west-central Florida. It is located within the 2,100 square mile watershed of the Withlacoochee River, which drains north and northwest towards the Gulf of Mexico. The lake system is managed by the Southwest Florida Water Management District as three distinct “pools,” which from upstream to downstream are referred to as the Floral City Pool, Inverness Pool, and Hernando Pool. Each pool contains a mixture of deep-water lakes that remain wet year round, ephemeral (seasonal) ponds and wetlands, and dry uplands. Many of the major deep-water lakes are interconnected by canals. Flow from the Withlacoochee River, when conditions allow, can be diverted into the lake system. Flow thorough the canals can be used to control the distribution of water between the three pools. Flow in the canals is controlled using structures, such as gates and weirs.Hydrogeologic units in the study area include a surficial aquifer consisting of Quaternary-age sediments, a discontinuous intermediate confining unit consisting of Miocene- and Pliocene-age sediments, and the underlying Upper Floridan aquifer, which consists of Eocene- and Oligocene-age carbonates. The fine-grained quartz sands that constitute the surficial aquifer are generally thin, typically less than 25 feet thick, within the vicinity of Tsala Apopka Lake. A thin, discontinuous, sandy clay layer forms the intermediate confining unit. The Upper Floridan aquifer is generally unconfined in the vicinity of Tsala Apopka Lake because the intermediate confining unit is discontinuous and breached by numerous karst features. In the study area, the Upper Floridan aquifer includes the upper Avon Park Formation and Ocala Limestone. The Ocala Limestone is the primary source of drinking water and spring flow in the area.The objectives of this study are to document the interaction of Tsala Apopka Lake, the surficial aquifer, and the Upper Floridan aquifer; and to estimate an annual water budget for each pool and for the entire lake system for 2004–12. The hydrologic interactions were evaluated using hydraulic head and geochemical data. Geochemical data, including major ion, isotope, and age-tracer data, were used to evaluate sources of water and to distinguish flow paths. Hydrologic connection of the surficial environment (lakes, ponds, wetlands, and the surficial aquifer) was quantified on the basis of a conceptualized annual water-budget model. The model included the change in surface water and groundwater storage, precipitation, evapotranspiration, surface-water inflow and outflow, and net groundwater exchange with the underlying Upper Floridan aquifer. The control volume for each pool extended to the base of the surficial aquifer and covered an area defined to exceed the maximum inundated area for each pool during 2004–12 by 0.5 foot. Net groundwater flow was computed as a lumped value and was either positive or negative, with a negative value indicating downward or lateral leakage from the control volume and a positive value indicating upward leakage to the control volume.The annual water budget for Tsala Apopka Lake was calculated using a combination of field observations and remotely sensed data for each of three pools and for the composite three pool area. A digital elevation model at a 5-foot grid spacing and bathymetric survey data were used to define the land-surface elevation and volume of each pool and to calculate the changes in inundated area with change in lake stage. Continuous lake-stage and groundwater-level data were used to define the change in storage for each pool. The rainfall data used in the water-budget calculations were based on daily radar reflectance data and measured rainfall from weather stations. Evapotranspiration was computed as a function of reference evapotranspiration, adjusted to actual evapotranspiration using a monthly land-cover coefficient (based on evapotranspiration measurements at stations located in representative landscapes). Surface-water inflows and outflows were determined using stage data collected at a series of streamgages installed primarily at the water-control structures. Discharge was measured under varying flow regimes and ratings were developed for the water-control structures. The discharge data collected during the study period were used to calibrate a surface-water flow model for 2004–12. Flows predicted by the model were used in the water-budget analysis. Net groundwater flow was determined as the residual term in the water-budget equation.The results of the water-budget analysis indicate that rainfall was the largest input of water to Tsala Apopka Lake, whereas evapotranspiration was the largest output. For the 2004–12 analysis period, surface-water inflow accounted for 11 percent of the inputs, net groundwater inflow accounted for 1 percent of inputs (annual periods with positive net groundwater flow were included as inputs, while annual periods with negative net groundwater flow were counted as outputs), and rainfall accounted for the remaining 88 percent. For the same period, the outputs consisted of 2 percent surface-water outflow, 12 percent net groundwater outflow, and 86 percent evapotranspiration. Net groundwater inflows and surface-water/groundwater storage were negligible during the water-budget period but could be important components of the budget in individual years.The net groundwater flow was negative (downward) for 8 out of the 9 years modeled (2004–12), indicating that the Tsala Apopka Lake study area was primarily a recharge area for the underlying Upper Floridan aquifer during this time period. Groundwater-level elevation in paired wells (adjacent wells completed in the surficial aquifer and Upper Floridan aquifer) typically was higher in the surficial aquifer than the Upper Floridan aquifer. However, hydraulic head data indicate that the surficial aquifer often has discharge potential to the surface-water system, especially in the low lying areas near the major lakes. Surficial-aquifer water levels were often higher than lake stages, especially during wet periods, which is likely an indication of aquifer-to-lake seepage in these areas. East of the major lakes, hydraulic head data were nearly equal in the surficial aquifer and Upper Floridan aquifer, which is an indication that the Upper Floridan aquifer is unconfined. Based on deuterium and oxygen stable isotope data collected in December 2011 and December 2012, there was no evidence of recharge to the Upper Floridan aquifer from the wetlands east of the major lakes; aquifer isotopic ratios did not indicate an enriched source, which is typical of lake and wetland sources. West of the major lakes, there was evidence of enriched isotopic ratios in water samples from the Upper Floridan aquifer. Differences in hydraulic head at paired wells in the surficial aquifer and Upper Floridan aquifer indicated that the surficial aquifer has the potential to recharge the Upper Floridan aquifer in the western part of the pools and west of the major lakes.

  5. Study of the wide area of a lake with remote sensing

    NASA Astrophysics Data System (ADS)

    Lazaridou, Maria A.; Karagianni, Aikaterini C.

    2016-08-01

    Water bodies are particularly important for environment and development issues. Their study requires multiple information. Remote sensing has been proven useful in the above study. This paper concerns the wide area of Lake Orestiada in the region of Western Macedonia in Greece. The area is of particular interest because Lake Orestiada is included in the Natura 2000 network and is surrounded by diverse landcovers as built up areas and agricultural land. Multispectral and thermal Landsat 5 satellite images of two time periods are being used. Their processing is being done by Erdas Imagine software. The general physiognomy of the area and the lake shore are examined after image enhancement techniques and image interpretation. Directions of the study concern geomorphological aspects, land covers, estimation of surface temperature as well as changes through time.

  6. Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska

    USGS Publications Warehouse

    Jones, Benjamin M.; Grosse, G.; Arp, C.D.; Jones, M.C.; Walter, Anthony K.M.; Romanovsky, V.E.

    2011-01-01

    Quantifying changes in thermokarst lake extent is of importance for understanding the permafrost-related carbon budget, including the potential release of carbon via lake expansion or sequestration as peat in drained lake basins. We used high spatial resolution remotely sensed imagery from 1950/51, 1978, and 2006/07 to quantify changes in thermokarst lakes for a 700 km2 area on the northern Seward Peninsula, Alaska. The number of water bodies larger than 0.1 ha increased over the entire observation period (666 to 737 or +10.7%); however, total surface area decreased (5,066 ha to 4,312 ha or -14.9%). This pattern can largely be explained by the formation of remnant ponds following partial drainage of larger water bodies. Thus, analysis of large lakes (>40 ha) shows a decrease of 24% and 26% in number and area, respectively, differing from lake changes reported from other continuous permafrost regions. Thermokarst lake expansion rates did not change substantially between 1950/51 and 1978 (0.35 m/yr) and 1978 and 2006/07 (0.39 m/yr). However, most lakes that drained did expand as a result of surface permafrost degradation before lateral drainage. Drainage rates over the observation period were stable (2.2 to 2.3 per year). Thus, analysis of decadal-scale, high spatial resolution imagery has shown that lake drainage in this region is triggered by lateral breaching and not subterranean infiltration. Future research should be directed toward better understanding thermokarst lake dynamics at high spatial and temporal resolution as these systems have implications for landscape-scale hydrology and carbon budgets in thermokarst lake-rich regions in the circum-Arctic.

  7. Abundances of northwestern salamander larvae in montane lakes with and without fish, Mount Rainier National Park, Washington

    USGS Publications Warehouse

    Larson, Gary L.; Hoffman, Robert L.

    2002-01-01

    In Mount Rainier National Park, the northwestern salamander usually inhabits relatively large and deep lakes and ponds (average size = 0.3 ha; average depth > 2 m) that contain flocculent, organic bottom sediments and abundant coarse wood. Prior to 1970, salmonids were introduced into many of the park's lakes and ponds that were typical habitat of the northwestern salamander. The objective of this study was to compare, in lakes and ponds with suitable habitat characteristics for northwestern salamanders, the observed abundances of larvae in takes and ponds with and without these introduced salmonids. Day surveys of 61 lakes were conducted between 1993 and 1999. Fish were limited to takes and ponds deeper than 2 in. For the 48 lakes and ponds deeper than 2 in (i.e., 25 fishless lakes and 23 fish lakes), the mean and median observed abundances of northwestern salamander larvae in fishless lakes and ponds was significantly greater than the mean and median observed abundances of larvae in lakes and ponds with fish. Northwestern salamander larvae were not observed in 11 fish lakes. These lakes were similar in median elevation, surface area, and maximum depth to the fishless lakes. The 12 fish lakes with observed larvae were significantly lower in median elevation, larger in median surface area, and deeper in median maximum depth than the fishless lakes. Low to null observed abundances of northwestern salamander larvae in lakes and ponds with fish were attributed to a combination of fish predation of larvae and changes in larval behavior.

  8. Water budget and estimated suspended-sediment inflow for Reelfoot Lake, Obion and Lake Counties, Northwestern Tennessee, May 1984-April 1985

    USGS Publications Warehouse

    Robbins, Clarence H.

    1985-01-01

    Reelfoot Lake in northwestern Tennessee, with a surface area of 15,500 acres at normal pool elevation, is the largest natural lake in Tennessee. Over the years, the lake has become an important economic, environmental, and recreational resource to the people in the area, and to the State of Tennessee. The natural eutrophic succession rate of the lake has apparently been accelerated by land use practices within the Reelfoot Lake drainage basin during the past several decades. The potential loss of Reelfoot Lake has prompted the State to make management and restoration of the lake and its resources a priority objective. The U.S. Geological Survey entered into a cooperative study in May 1984 with the Tennessee Wildlife Resources Agency and the Tennessee Department of Health and Environment, Division of Water Management, to collect and analyze hydrologic data and prepare an annual water budget for Reelfoot Lake. The purpose of the water budget is to provide an analysis of the surface-groundwater-lake-atmospheric water relation at Reelfoot Lake. Results of the analysis can be used by lake managers to evaluate the potential effects of proposed lake management strategies upon the lake and surrounding hydrologic system. The water budget for the 12-month study period (May 1, 1984 through April 30, 1985) is presented in this report. In addition, estimates of suspended-sediment discharge from tributary streams in the Reelfoot Lake basin and an analysis of concentrations of constituents in stream-bottom material at three inflow sites are also presented. (Lantz-PTT)

  9. Drastic change in China's lakes and reservoirs over the past decades.

    PubMed

    Yang, Xiankun; Lu, Xixi

    2014-08-13

    Using remote sensing images, we provided the first complete picture of freshwater bodies in mainland China. We mapped 89,700 reservoirs, covering about 26,870 km(2) and approximately 185,000 lakes with a surface area of about 82,232 km(2). Despite relatively small surface area, the total estimated storage capacity of reservoirs (794 km(3)) is triple that of lakes (268 km(3)). Further analysis indicates that reservoir construction has made the river systems strongly regulated: only 6% of the assessed river basins are free-flowing; 20% of assessed river basins have enough cumulative reservoir capacity to store more than the entire annual river flow. Despite the existence of 2,721 lakes greater than 1 km(2), we found that about 50 lakes greater than km(2) have formed on the Tibetan Plateau resulting from climate change. More than 350 lakes of ≥1 km(2) vanished in four other major lake regions. Although the disappearance of lakes happened in the context of global climate change, it principally reflects the severe anthropogenic impacts on natural lakes, such as, the excessive plundering of water resources on the Inner Mongolia-Xinjiang Plateau and serious destruction (land reclamation and urbanization) on the eastern plains.

  10. Annual contribution of carbon, nitrogen, and phosphorus by migrant Canada geese to a hardwater lake

    USGS Publications Warehouse

    Manny, Bruce A.; Wetzel, Robert G.; Johnson, W.C.

    1975-01-01

    Each year more than 6,000 migrant Canada geese (Branta canadensis interior Todd) rest for 3 to 10 days during the months of March, October, November, and December on Wintergreen Lake, a productive 15 ha (33 acre) hardwater lake in the W. K. Kellogg Bird Sanctuary of Michigan State University in southwestern Michigan. For the past six years accurate weekly counts have been made of resident and migrant waterfowl using Wintergreen Lake. During the past four years Wintergreen Lake has been the site of extensive limnological investigations relating nutrient dynamics and primary productivity. These limnological investigations suggested nutrients contributed by migrant Canada geese were the chief cause of hypereutrophic primary productivity conditions in Wintergreen Lake. Until January 1970, the unpredictable habits of wild Canada geese using Wintergreen Lake prevented accurate estimation of nutrients contributed ton the lake in the form of goose feces. An opportunity to measure this source of nutrients was presented on 9 to 11 January 1970 when about 600 late fall migrant Canada geese rested part of three days in a clearly defined area on newly fallen snow covering frozen Wintergreen Lake. During their stay on the lake accurate records were kept of goose numbers, their location on the lake surface, hours spent on the ice and hours spent feeding off the lake. After the geese left on 11 January 1970, a random sampling procedure was used to measure the density of droppings deposited within the area used by the geese on the lake surface.

  11. The Cultural Resources and Geomorphology of Coralville Lake, Johnson County, Iowa. Volume 1. Technical Report.

    DTIC Science & Technology

    1984-04-01

    PERIOD COVERED THE CULTURAL RESOURCES AND GEOMORPHOLOGY OF FINAL 1984 CORALVILLE LAKE, JOHNSON COUNTY. IOWA 6 PERORMINGORG.REPORTNMBER 7. AUTHOR() 0...County, Iowa (see Figure 1). Coralville Dam Is located on the Iowa River approximately 7 miles above Iowa City, and inundates an area, at maximum flood...landform regions in Iowa . Two of these regions, namely, the Iowan Surface and the Southern Iowa Drift Plain, are in the Coralville Lake area. The

  12. The CO2 Flux and the Chemistry of the Crater lake in 2013-2015 Evidence for the Enhanced Activity of El Chichon volcano, Mexico.

    NASA Astrophysics Data System (ADS)

    Taran, Y.; Jácome Paz, M. P.; Inguaggiato, S.; Collard, N.

    2015-12-01

    During 2013-2015, four CO2 flux surveys were performed in the El Chichon crater both, from the lake surface and from the soil of the crater. The chemistry of the lake water, as well as its physical parameters (surface area, depth, temperature) were also determined. The CO2 flux in 2014-2015 compared to the 2007-2008 data (Mazot et al., 2011, BV, 73: 423-441) increased almost one order of magnitude (from ~ 140 ton d-1 in 2008 to ~ 840 ton d-1 in 2014). During the last two years the lake became the largest for the whole time of observations with the maximum surface area more than 18 ha covering completely the NE fumarolic field and all thermal springs feeding the lake with mineralized water. Despite the maximum volume of the lake it was characterized in 2015 by the highest since 2007 chloride content (~2500 ppm) and temperature (34°C). A large degassing spot in the middle of the lake for the first time was observed in April 2015 with more than 10,000 g m-2 d-1 of the CO2 flux. These observations evidence that the volcano-hydrothermal system of El Chichon volcano came into a new stage of activity associated most probably with changes in the magmatic activity at depth.

  13. Lake Powell

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The white ring around Lake Powell tells the story. The surface is down 98 feet. This is critical, because Powell, Lake Mead, and other lakes along the Colorado River provide water for millions of people in five states. We are in the eighth year of a drought on the Colorado River. This year was the driest year ever reported in Southern California, and there is a severe drought in Northern California, down to less than 30-percent of snow pack. This ASTER image of part of Lake Powell was acquired in 2001. The gray area depicts the shrunken, reduced 2007 lake extent compared to the extended, larger black area in 2001.

    The image covers an area of 24 x 30 km, and is centered near 37.1 degrees north latitude, 111.3 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  14. Remote sensing monitoring study of ecological environment change in Qingtu Lake

    NASA Astrophysics Data System (ADS)

    Han, Tao; Wang, Dawei; Jiang, Youyan; Qian, Li; Chen, Lei; Hao, Xiaocui

    2018-03-01

    Based on the Environmental Mitigation Satellite (HJ-1) data, this paper has carried on the remote sensing monitoring to change of the surrounding vegetation and water area of the Qingtu Lake since 2009. The result shows that the average area of water has increased by 3.59 square kilometres annually since the reappearance of the waters with the Qingtu Lake in 2010. The area of Qingtu Lake and surrounding vegetation cover has presented an average increase of 1.09 square kilometres per year. Since 2010, the precipitation of the Qingtu Lake and its surrounding area in Minqin county have a significant increase in the trend, the average increase rate of 6.0 mm/year. Compared to 2010 years ago, the average precipitation increased 36.4 mm. And it shows that the change of the Qingtu Lake underlying surface has a positive feedback effect to local heavy rainfall according to the comparative analysis of the precipitation observation in the surrounding weather station.

  15. Bathymetric map and area/capacity table for Castle Lake, Washington

    USGS Publications Warehouse

    Mosbrucker, Adam R.; Spicer, Kurt R.

    2017-11-14

    The May 18, 1980, eruption of Mount St. Helens produced a 2.5-cubic-kilometer debris avalanche that dammed South Fork Castle Creek, causing Castle Lake to form behind a 20-meter-tall blockage. Risk of a catastrophic breach of the newly impounded lake led to outlet channel stabilization work, aggressive monitoring programs, mapping efforts, and blockage stability studies. Despite relatively large uncertainty, early mapping efforts adequately supported several lake breakout models, but have limited applicability to current lake monitoring and hazard assessment. Here, we present the results of a bathymetric survey conducted in August 2012 with the purpose of (1) verifying previous volume estimates, (2) computing an area/capacity table, and (3) producing a bathymetric map. Our survey found seasonal lake volume ranges between 21.0 and 22.6 million cubic meters with a fundamental vertical accuracy representing 0.88 million cubic meters. Lake surface area ranges between 1.13 and 1.16 square kilometers. Relationships developed by our results allow the computation of lake volume from near real-time lake elevation measurements or from remotely sensed imagery.

  16. Analysis of water-surface profiles in Leon County and the city of Tallahassee, Florida

    USGS Publications Warehouse

    Franklin, M.A.; Orr, R.A.

    1987-01-01

    Water surface profiles for the 10-, 25-, 50-, and 100-yr recurrence interval floods for most of the streams that drain developing areas of Leon County and the city of Tallahassee are presented. The principal streams studied are in the Lake Munson, Lake Lafayette, and Lake Jackson basins Peak discharges were computed from regression equations based on information gained from 15 streamflow stations in the area. Standard step-backwater procedures were used to determine the water-surface elevations for the streams. The flood elevations were generally higher than those in the Flood Insurance Studies for Tallahassee (1976) and Leon County (1982). The primary reason for the higher profiles is that peak discharges used in this report are larger than those used previously, largely due to changes in land use. The flood profiles for Bradford Brook, North Branch Gum Creek, and West Branch Gum Creek generally match those in the Leon County Flood Insurance Studies. Channel improvements in some areas would lower the flood elevation in that area, but would probably increase flooding downstream. (Lantz-PTT)

  17. A comparison of interpolation methods on the basis of data obtained from a bathymetric survey of Lake Vrana, Croatia

    NASA Astrophysics Data System (ADS)

    Šiljeg, A.; Lozić, S.; Šiljeg, S.

    2014-12-01

    The bathymetric survey of Lake Vrana included a wide range of activities that were performed in several different stages, in accordance with the standards set by the International Hydrographic Organization. The survey was conducted using an integrated measuring system which consisted of three main parts: a single-beam sonar Hydrostar 4300, GPS devices Ashtech Promark 500 - base, and a Thales Z-Max - rover. A total of 12 851 points were gathered. In order to find continuous surfaces necessary for analysing the morphology of the bed of Lake Vrana, it was necessary to approximate values in certain areas that were not directly measured, by using an appropriate interpolation method. The main aims of this research were as follows: to compare the efficiency of 16 different interpolation methods, to discover the most appropriate interpolators for the development of a raster model, to calculate the surface area and volume of Lake Vrana, and to compare the differences in calculations between separate raster models. The best deterministic method of interpolation was ROF multi-quadratic, and the best geostatistical, ordinary cokriging. The mean quadratic error in both methods measured less than 0.3 m. The quality of the interpolation methods was analysed in 2 phases. The first phase used only points gathered by bathymetric measurement, while the second phase also included points gathered by photogrammetric restitution. The first bathymetric map of Lake Vrana in Croatia was produced, as well as scenarios of minimum and maximum water levels. The calculation also included the percentage of flooded areas and cadastre plots in the case of a 2 m increase in the water level. The research presented new scientific and methodological data related to the bathymetric features, surface area and volume of Lake Vrana.

  18. The Volume of Earth's Lakes

    NASA Astrophysics Data System (ADS)

    Cael, B. B.

    How much water do lakes on Earth hold? Global lake volume estimates are scarce, highly variable, and poorly documented. We develop a mechanistic null model for estimating global lake mean depth and volume based on a statistical topographic approach to Earth's surface. The volume-area scaling prediction is accurate and consistent within and across lake datasets spanning diverse regions. We applied these relationships to a global lake area census to estimate global lake volume and depth. The volume of Earth's lakes is 199,000 km3 (95% confidence interval 196,000-202,000 km3) . This volume is in the range of historical estimates (166,000-280,000 km3) , but the overall mean depth of 41.8 m (95% CI 41.2-42.4 m) is significantly lower than previous estimates (62 - 151 m). These results highlight and constrain the relative scarcity of lake waters in the hydrosphere and have implications for the role of lakes in global biogeochemical cycles. We also evaluate the size (area) distribution of lakes on Earth compared to expectations from percolation theory. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. 2388357.

  19. Movements of hatchery-reared lake trout in Lake Superior

    USGS Publications Warehouse

    Pycha, Richard L.; Dryer, William R.; King, George R.

    1965-01-01

    The history of stocking of lake trout (Salvelinus namaycush) in the Great Lakes is reviewed. The study of movements is based on capture of 24,275 fin-clipped lake trout taken in experimental gill nets and trawls and commercial gill nets. Yearling lake trout planted from shore dispersed to 15-fath (27-m) depths in 3A? hr. Most fish remained within 2 miles (3.2 km) of the planting site 2 months, but within 4 months some fish had moved as much as 17 miles (27 km). The highest abundance of planted lake trout was in areas 2-4 miles (3.2-6.4 km) from the planting site even 3 years after release. Distance moved and size of fish were not correlated. Dispersal of lake trout begins at planting and probably continues until the fish are mature. Most movement was eastward in southern Lake Superior and followed the counterclockwise surface currents. Movement is most rapid in areas of strong currents and slowest in areas of weak currents or eddies. Movement to areas west of the Keweenaw Peninsula was insignificant from plantings in Keweenaw Bay and nil from other plantings farther east. Lake trout planted in the eastern third of the lake dispersed more randomly than those planted farther west. Few fish moved farther offshore than the 50-fath (91-m) contour. Lake trout planted in Canadian waters made insignificant contributions to populations in US waters.

  20. Hydrographic Surveys for Six Water Bodies in Eastern Nebraska, 2005-07

    USGS Publications Warehouse

    Johnson, Michaela R.; Andersen, Michael J.; Sebree, Sonja K.

    2008-01-01

    The U.S. Geological Survey, in cooperation with the Nebraska Department of Environmental Quality, completed hydrographic surveys for six water bodies in eastern Nebraska: Maskenthine Wetland, Olive Creek Lake, Standing Bear Lake, Wagon Train Lake and Wetland, Wildwood Lake, and Yankee Hill Lake and sediment basin. The bathymetric data were collected using a boat-mounted survey-grade fathometer that operated at 200 kHz, and a differentially corrected Global Positioning System with antenna mounted directly above the echo-sounder transducer. Shallow-water and terrestrial areas were surveyed using a Real-Time Kinematic Global Positioning System. The bathymetric, shallow-water, and terrestrial data were processed in a geographic information system to generate a triangulated irregular network representation of the bottom of the water body. Bathymetric contours were interpolated from the triangulated irregular network data using a 2-foot contour interval. Bathymetric contours at the conservation pool elevation for Maskenthine Wetland, Yankee Hill Lake, and Yankee Hill sediment pond also were interpolated in addition to the 2-foot contours. The surface area and storage capacity of each lake or wetland were calculated for 1-foot intervals of water surface elevation and are tabulated in the Appendix for all water bodies.

  1. Ground-Water Hydrology of the Upper Klamath Basin, Oregon and California

    USGS Publications Warehouse

    Gannett, Marshall W.; Lite, Kenneth E.; La Marche, Jonathan L.; Fisher, Bruce J.; Polette, Danial J.

    2007-01-01

    The upper Klamath Basin spans the California-Oregon border from the flank of the Cascade Range eastward to the Basin and Range Province, and encompasses the Klamath River drainage basin above Iron Gate Dam. Most of the basin is semiarid, but the Cascade Range and uplands in the interior and eastern parts of the basin receive on average more than 30 inches of precipitation per year. The basin has several perennial streams with mean annual discharges of hundreds of cubic feet per second, and the Klamath River at Iron Gate Dam, which represents drainage from the entire upper basin, has a mean annual discharge of about 2,100 cubic feet per second. The basin once contained three large lakes: Upper and Lower Klamath Lakes and Tule Lake, each of which covered areas of 100 to 150 square miles, including extensive marginal wetlands. Lower Klamath Lake and Tule Lake have been mostly drained, and the former lake beds are now cultivated. Upper Klamath Lake remains, and is an important source of irrigation water. Much of the wetland surrounding Upper Klamath Lake has been diked and drained, although efforts are underway to restore large areas. Upper Klamath Lake and the remaining parts of Lower Klamath and Tule Lakes provide important wildlife habitat, and parts of each are included in the Klamath Basin National Wildlife Refuges Complex. The upper Klamath Basin has a substantial regional ground-water flow system. The late Tertiary to Quaternary volcanic rocks that underlie the region are generally permeable, with transmissivity estimates ranging from 1,000 to 100,000 feet squared per day, and compose a system of variously interconnected aquifers. Interbedded with the volcanic rocks are late Tertiary sedimentary rocks composed primarily of fine-grained lake sediments and basin-filling deposits. These sedimentary deposits have generally low permeability, are not good aquifers, and probably restrict ground-water movement in some areas. The regional ground-water system is underlain and bounded on the east and west by older Tertiary volcanic and sedimentary rocks that have generally low permeability. Eight regional-scale hydrogeologic units are defined in the upper Klamath Basin on the basis of surficial geology and subsurface data. Ground water flows from recharge areas in the Cascade Range and upland areas in the basin interior and eastern margins toward stream valleys and interior subbasins. Ground water discharge to streams throughout the basin, and most streams have some component of ground water (baseflow). Some streams, however, are predominantly ground-water fed and have relatively constant flows throughout the year. Large amounts of ground water discharges in the Wood River subbasin, the lower Williamson River area, and along the margin of the Cascade Range. Much of the inflow to Upper Klamath Lake can be attributed to ground-water discharge to streams and major spring complexes within a dozen or so miles from the lake. This large component of ground water buffers the lake somewhat from climate cycles. There are also ground-water discharge areas in the eastern parts of the basin, for example in the upper Williamson and Sprague River subbasins and in the Lost River subbasin at Bonanza Springs. Irrigated agriculture is an integral part of the economy of the upper Klamath Basin. Although estimates vary somewhat, roughly 500,000 acres are irrigated in the upper Klamath Basin, about 190,000 acres of which are part of the Bureau of Reclamation Klamath Project. Most of this land is irrigated with surface water. Ground water has been used for many decades to irrigate areas where surface water is not available, for example outside of irrigation districts and stream valleys. Ground water has also been used as a supplemental source of water in areas where surface water supplies are limited and during droughts. Ground water use for irrigation has increased in recent years due to drought and shifts in surface-water allocation from irrigati

  2. Archaeological Investigations at the Lewis Site (3LE266): A Twentieth- Century Black Owned Farmstead on the St. Francis Floodway, Lee County, Arkansas

    DTIC Science & Technology

    1992-09-01

    Nash Museum. Testing of suspected mound site near Reelfoot Lake , Obion5 County, Tennessee. Archaeological surface survey of areas in Tipton County...swamps, and oxbow lakes . The areas between Crowleys Ridge. and the St.O Francis Floodway are urained by the floodway. The prime farmland east of the...as were migratory mallard ducks (Anas platyrhynchos) and canadian geese (Branta canadensis). Fish from the larger streams, oxbow lakes , and beaver

  3. Archaeological Survey Along the Obion River: Cultural Resources Survey and Testing Below Sharon and Sidonia, Obion, Weakley, and Gibson Counties, Western Tennessee

    DTIC Science & Technology

    1987-04-22

    in some areas, especially those near Reelfoot Lake . In amny, the water table remains at or near the surface the entire summer. In others, it drops as...114) has documented early historic vugetational communities around Reelfoot Lake , immediately to the west. In brief, higher, interriverine areas were... Reelfoot Lake . N Away from the river, comparatively few major centers, or sites of any kind, have been reported in the interior Western Coastal Plain

  4. Seismic investigation of Lake Issyk-Kul, Kyrgyzstan

    NASA Astrophysics Data System (ADS)

    Gebhardt, C.; Naudts, L.; De Mol, L.; De Batist, M.

    2012-04-01

    Lake Issyk-Kul is located in an intramontane basin of the Tien Shan mountains in Kyrgyzstan, Central Asia. It has formed in a tectonically active region with W-E striking major thrust zones north and south of the lake. The lake's modern surface level is at 1607 m above sea level, maximum depth in the central basin of the lake is roughly 670 m, and the total water volume is around 1736 km3. The lake is elongated with 180 km in west-east and 60 km in south-north direction. With a surface area of 6232 km2, Lake Issyk-Kul is the second largest lake in the higher altitudes. The lake is characterized by two large delta areas at its western and eastern end, with the deltaic area being as wide as up to 60 km in the eastern and 40 km in the western part, and by steep slopes at the northern and southern shore with only a rather narrow shallower shelf area. The lake contains the sediments of the past up to several million years, and has been proposed as a future target for deep drilling within ICDP. Three seismic surveys by Russian and Belgian groups in 1982, 1997 and 2001 revealed a thick sediment infill in Lake Issyk-Kul. At both the western and the eastern end of the lake, large delta systems were formed by actual and previous inlets, namely the Tyup and Djyrgalan rivers in the eastern part of the lake (still active) and the Chu River at the western end (currently bypassing the lake). Large sub-aquatic channel systems are visible in the lake's bathymetry in the shallower part of the delta systems close to the river mouths. They were quite likely formed by these rivers during a former lake level lowstand. The delta system consists of stacked prograding delta lobes with a characteristic topset-foreset-bottomset configuration. These lobes together with sub-aerial terraces found at several spots around the lake witness lake level fluctuations of up to >400 m. The sediments in the central plain of Lake Issyk-Kul are mainly well-layered with many turbiditic sequences intercalated with pelagic background sedimentation. Sediments are slightly inclined towards south with increasing angles with depth, suggesting a halfgraben structure of the lake basin. Mass transport deposits such as debris flows are a common feature close to the steeper flanks around the central plain. The southern flank is characterized by many small terraces and several canyons that are related to the small inlets at the southern shore. The northern flank, however, shows a small, shallow shelf area of 25 to 30 m water depth. This area is characterized by glacial outwash sediments brought to the lake by small rivers that drain the large terminal moraines which are located north of the lake.

  5. Lake Erie: Effects of exploitation, environmental changes and new species on the fishery resources

    USGS Publications Warehouse

    Hartman, Wilbur L.

    1972-01-01

    In no other lake as large as Lake Erie (surface area, 25,690 km2) have such extensive changes taken place in the drainage basin, the lake environment, and the fish populations over the last 100 years. Deforestation and prairie burning led to erosion and siltation of valuable spawning grounds. Marsh spawning areas were drained. Lake-to-river spawning migrations were blocked by mill dams. Accelerated cultural nutrient loading increased total dissolved solids by nearly 50% (1920-70). Average summer water temperatures increased 1.1 C. Phytoplankton and zooplankton abundance increased severalfold. Severe oxygen depletion developed in the bottom waters of all three basins of the lake. Lake sturgeon were fished out as nuisance fish in the late 1800s. The commercial fisheries for lake trout, lake whitefish, and lake herring collapsed by 1940 and those for blue pike and walleye by 1960. Yellow perch production became unstable in the 1960s. The effects of exploitation, environmental changes, and new species on these fish populations are discussed.

  6. Water budgets, water quality, and analysis of nutrient loading of the Winter Park chain of lakes, central Florida, 1989-92

    USGS Publications Warehouse

    Phelps, G.G.; German, E.R.

    1995-01-01

    The Winter Park chain of lakes (Lakes Maitland, Virginia, Osceola, and Mizell) has a combined area of about 900 acres, an immediate drainage area of about 3,100 acres, and mean depths ranging from 11 to 15 feet. The lakes are an important recreational resource for the surrounding communities, but there is concern about the possible effects of stormwater runoff and seepage of nutrient-enriched ground water on the quality of water in the lakes. The lakes receive water from several sources: rainfall on lake surfaces, inflow from other surface-water bodies, stormflow that enters the lakes through storm drains or by direct runoff from land adjacent to the lakes and ground-water seepage. Water leaves the lakes by evaporation, surface outflow, and ground-water outflow. Of the three, only surface outflow can be measured directly. Rainfall, surface inflow and outflow, and lake-stage data were collected from October 1, 1989, to September 30, 1992. Stormflow, evaporation and ground-water inflow and outflow were estimated for the 3 years of the study. Ground-water outflow was calculated by evaluating the rate of lake-stage decline during dry periods. Estimated ground-water outflow was compared to downward leakage rates estimated by ground-water flow models. Lateral ground-water inflow from surficial sediments was calculated as the residual of the flow budget. Flow budgets were calculated for the 3 years of the study. In water year 1992 (a year with about average rainfall), inflow consisted of rainfall, 48 inches; stormflow, 15 inches; surface inflow, 67 inches; and ground water, 40 inches. The calculated outflows were evaporation, 47 inches; surface outflow, 90 inches; and ground water, 33 inches. Water-quality data also were used to calculate nutrient budgets for the lakes. Bimonthly water samples were collected from the lakes and at surface inflow and outflow sites, and were analyzed for physical characteristics, dissolved oxygen, pH, specific conductance, major ions, the nutrients nitrogen and phosphorus, and chlorophyll (collected at lake sites only). Specific conductance ranged from about 190 to 230 microsiemens per centimeter at 25 degrees Celsius in Lakes Maitland, Virginia and Osceola and from about 226 to 260 microsiemens per centimeter at 25 degrees Celsius in Lake Mizell. The median concentrations of total ammonia-plus-organic nitrogen in all the lakes ranged from 0.79 to 0.99 milligrams per liter. Median total phosphorus concentrations ranged from less than 0.02 to 0.20 milligrams per liter. Stormwater samples were collected for 17 storms at one storm-drain site and 16 storms at another storm-drain site on Lake Osceola. Median total nitrogen concentrations at the sites were 2.23 and 3.06 milligrams per liter and median total phosphorus concentrations were 0.34 and 0.40 milligrams per liter. The water quality in the Winter Park lakes generally is fair to good, based on a trophic-state index used by the Florida Department of Environmental Protection for assessing the tropic state of Florida lakes. This index was determined from median total nitrogen, total phosphorus, and chlorophyll-a concentrations, and median Secchi-disk transparency for all lakes for the period September 1989 to June 1992. Based on a one-time sampling of 20 sites around the lakes, surficial ground-water quality is highly variable. Nutrient concentrations were highly variable and could not be correlated to the proximity of septic tanks. Fertilizer probably is the primary source of nutrients in the surficial ground water. Nutrient budgets were calculated for the lakes for the 3 years of the study. The most variable source of nutrient loading to the lakes is stormwater. Nutrient-loading modeling indicates that reduction of nutrients in stormflow probably would improve lake-water quality. However, even with complete removal of nitrogen and phosphorus from stormwater, the lakes might still be mesotrophic with respect to both nutrients during periods of below ave

  7. Hydrologic relations between lakes and aquifer in a recharge area near Orlando, Florida

    USGS Publications Warehouse

    Lichtler, William F.; Hughes, G.H.; Pfischner, F.L.

    1976-01-01

    The three lakes investigated in Orange County, Florida, gain water from adjoining water-table aquifer and lose water to Floridan aquifer by downward leakage. Net seepage (net exchange of water between lake and aquifers) can be estimated by equation S = AX + BY, where S is net seepage, X represents hydraulic gradient between lake and water-table aquifer, A is lumped parameter representing effect of hydraulic conductivity and cross-sectional area of materials in flow section of water-table aquifer, Y is head difference between lake level and potentiometric surface of Floridan aquifer, and B is lumped parameter representing effect of hydraulic conductivity, area, and thickness of materials between lake bottom and Floridan aquifer. If values of S, X, and Y are available for two contrasting water-level conditions, coefficients A and B are determinable by solution of two simultaneous equations. If the relation between lake and ground-water level is the same on all sides of the lake--with regard to each aquifer--and if X and Y are truly representative of these relations, then X and Y terms of equation provide valid estimates of inflow to lake from water-table aquifer and outflow from lake to Floridan aquifer. (Woodard-USGS)

  8. Chemical quality of surface waters in Devils Lake basin, North Dakota

    USGS Publications Warehouse

    Swenson, Herbert; Colby, Bruce R.

    1955-01-01

    Devils Lake basin, a closed basin in northeastern North Dakota, covers about 3,900 square miles of land, the topography of which is morainal and of glacial origin. In this basin lies a chain of waterways, which begins with the Sweetwater group and extends successively through Mauvais Coulee, Devils Lake, East Bay Devils Lake, and East Devils Lake, to Stump Lake. In former years when lake levels were high, Mauvais Coulee drained the Sweetwater group and discharged considerable water into Devils Lake. Converging coulees also transported excess water to Stump Lake. For at least 70 years prior to 1941, Mauvais Coulee flowed only intermittently, and the levels of major lakes in this region gradually declined. Devils Lake, for example, covered an area of about 90,000 acres in 1867 but had shrunk to approximately 6,500 acres by 1941. Plans to restore the recreational appeal of Devils Lake propose the dilution and eventual displacement of the brackish lake water by fresh water that would be diverted from the Missouri River. Freshening of the lake water would permit restocking Devils Lake with fish. Devils and Stump Lake have irregular outlines and numerous windings and have been described as lying in the valley of a preglacial river, the main stem and tributaries of which are partly filled with drift. Prominent morainal hills along the south shore of Devils Lake contrast sharply with level farmland to the north. The mean annual temperature of Devils Lake basin ranges between 36 ? and 42 ? F. Summer temperatures above 100 ? F and winter temperatures below -30 ? Fare not uncommon. The annual precipitation for 77 years at the city of Devils Lake averaged 17.5 inches. Usually, from 75 to 80 percent of the precipitation in the basin falls during the growing season, April to September. From 1867 to 1941 the net fall of the water surface of Devils Lake was about 38 feet. By 1951 the surface had risen fully 14 feet from its lowest altitude, 1,400.9 feet. Since 1951, the level has fallen slowly. Hydrologic changes that may have caused Devils Lake to alter from a very large, moderately deep lake of fresh water to a small, shallow body of brackish water are discussed and evaluated on the basis of scanty information. During several years of average precipitation, temperature, and evaporation, Devils Lake and lakes upstream should receive nearly a quarter of an inch of runoff annually from the drainage area of about 3,000 square miles. Approximately 55 square miles of tributary area would be required to maintain each square mile of lake surface. However, runoff, expressed as percentage of the average, differs greatly from year to year. The amount of runoff retained in upstream lakes also Varies greatly. For these two reasons, annual inflow to Devils Lake is extremely variable. Because many waterways in this basin have no surface outlets at normal stages, runoff collects in depressions, is concentrated by evaporation, and forms saline or alkaline lakes. The chemical and physical properties of the lake waters vary chiefly with changes in lake stage and volume of inflow. Scattered records from 1899 to 1923 and more comprehensive data from 1948 to 1952 show a range of salt concentration from 6,130 to 25,000 parts per million (ppm) in the water of Devils Lake. Although concentration has varied, the chemical composition of the dissolved solids has not changed appreciably. Lake waters are more concentrated in the lower part of the basin, downstream from Devils Lake. For periods of record the salt concentration ranged from 14,932 to 62,000 ppm in East Devils Lake and from 19,000 to 106,000 ppm in east Stump Lake. Current and past tonnages of dissolved solids in Devils Lake, East Bay Devils Lake, East Devils Lake, and east and west Stump Lakes were computed from concentrations and from altitude-capacity curves for each lake. Neither the average rate of diversion of water to restore Devils Lake to a higher level nor the quality of the divert

  9. Modeling nearshore-offshore exchange in Lake Superior

    PubMed Central

    Tokos, Kathy S.; Matsumoto, Katsumi

    2018-01-01

    Lake Superior′s ecosystem includes distinct nearshore and offshore food webs linked by hydrodynamic processes that transport water and tracers along and across shore. The scales over which these processes occur and their sensitivity to increasing summer surface temperatures are not well understood. This study investigated horizontal mixing between nearshore and offshore areas of Lake Superior over the 10-year period from 2003 to 2012 using a realistically forced three-dimensional numerical model and virtual tracers. An age tracer was used to characterize the time scales of horizontal mixing between nearshore areas of the lake where water depth is less than 100 m and deeper areas. The age of water in nearshore areas increased and decreased in an annual cycle corresponding to the lake′s dimictic cycle of vertical mixing and stratification. Interannual variability of mixing in the isothermal period was significantly correlated to average springtime wind speed, whereas variability during the stratified season was correlated to the average summer surface temperature. Dispersal of a passive tracer released from nine locations around the model lake’s perimeter was more extensive in late summer when stratification was established lakewide than in early summer. The distribution of eddies resolved in the model reflected differences between the early and late summer dispersal patterns. In the eastern part of the lake dispersal was primarily alongshore, reflecting counterclockwise coastal circulation. In the western part of the lake, cross-shore mixing was enhanced by cross-basin currents. PMID:29447286

  10. Long-term MODIS observations of cyanobacterial dynamics in Lake Taihu: Responses to nutrient enrichment and meteorological factors

    PubMed Central

    Shi, Kun; Zhang, Yunlin; Zhou, Yongqiang; Liu, Xiaohan; Zhu, Guangwei; Qin, Boqiang; Gao, Guang

    2017-01-01

    We developed and validated an empirical model for estimating chlorophyll a concentrations (Chla) in Lake Taihu to generate a long-term Chla and algal bloom area time series from MODIS-Aqua observations for 2003 to 2013. Then, based on the long-term time series data, we quantified the responses of cyanobacterial dynamics to nutrient enrichment and climatic conditions. Chla showed substantial spatial and temporal variability. In addition, the annual mean cyanobacterial surface bloom area exhibited an increasing trend across the entire lake from 2003 to 2013, with the exception of 2006 and 2007. High air temperature and phosphorus levels in the spring can prompt cyanobacterial growth, and low wind speeds and low atmospheric pressure levels favor cyanobacterial surface bloom formation. The sensitivity of cyanobacterial dynamics to climatic conditions was found to vary by region. Our results indicate that temperature is the most important factor controlling Chla inter-annual variability followed by phosphorus and that air pressure is the most important factor controlling cyanobacterial surface bloom formation followed by wind speeds in Lake Taihu. PMID:28074871

  11. Comparison of evaporation at two central Florida lakes, April 2005–November 2007

    USGS Publications Warehouse

    Swancar, Amy

    2015-09-25

    Both lakes are seepage lakes (no surface-water inflow or outflows) that are dependent on groundwater inflow from their basins to offset an atmospheric deficit, because long-term rainfall in this area is less than evaporation. The Lake Starr basin, where sandy, well-drained ridges surround the lake, has a greater capacity to store infiltrating rain than the Lake Calm basin, which is flat and has poorly drained soils. The storage capacities of the basins affect groundwater exchange with the lakes. Rainfall and net groundwater exchange, which is related to basin characteristics, varied more between these two lakes than did evaporation during this study.

  12. NEARBY LAKE SEDIMENT QUALITY AND SEEDLING TREE SURVIVAL ON ERODED OILY WASTE/BRINE CONTAMINATED SOIL

    EPA Science Inventory

    An ecosystem restoration study is being conducted at an old oil production area in Northeast Oklahoma. Surface soil samples from areas impacted by discarded crude oil and brine wastes have been chemically characterized. Surface erosion has occurred in areas impacted by waste disc...

  13. Effects of lawn fertilizer on nutrient concentration in runoff from lakeshore lawns, Lauderdale Lakes, Wisconsin

    USGS Publications Warehouse

    Garn, Herbert S.

    2002-01-01

    Transport of nutrients (primarily forms of nitrogen and phosphorus) to lakes and resulting accelerated eutrophication are serious concerns for planners and managers of lakes in urban and developing suburban areas of the country. Runoff from urban land surfaces such as streets, lawns, and rooftops has been noted to contain high concentrations of nutrients; lawns and streets were the largest sources of phosphorus in residential areas (Waschbusch, Selbig and Bannerman, 1999). The cumulative contribution from many lawns to the amount of nutrients in lakes is not well understood and potentially could be a large part of the total nutrient contribution.

  14. Final Environmental Assessment: Evaluation of Prescribed Burning for Ecological Restoration and Forest Management

    DTIC Science & Technology

    2005-01-01

    north. Most of the birds winter in western parts of the state, particularly at Reelfoot Lake , and at Dale Hollow Reservoir. However, bald eagles may...Units Final Environmental Assessment d Tims Ford Lake Crumpton Creek Sinking Pond Retention Reservoir ormandy Lake Woods Reservoir P:\\ARNOLDAFB...occur in long narrow areas on first bottoms along streams (USDA SCS, 1949). 3.3.3 Hydrology Hydrological features consist of surface waters ( lakes

  15. Microplastics in Taihu Lake, China.

    PubMed

    Su, Lei; Xue, Yingang; Li, Lingyun; Yang, Dongqi; Kolandhasamy, Prabhu; Li, Daoji; Shi, Huahong

    2016-09-01

    In comparison with marine environments, the occurrence of microplastics in freshwater environments is less understood. In the present study, we investigated microplastic pollution levels during 2015 in Taihu Lake, the third largest Chinese lake located in one of the most developed areas of China. The abundance of microplastics reached 0.01 × 10(6)-6.8 × 10(6) items/km(2) in plankton net samples, 3.4-25.8 items/L in surface water, 11.0-234.6 items/kg dw in sediments and 0.2-12.5 items/g ww in Asian clams (Corbicula fluminea). The average abundance of microplastics was the highest in plankton net samples from the southeast area of the lake and in the sediments from the northwest area of the lake. The northwest area of the lake was the most heavily contaminated area of the lake, as indicated by chlorophyll-α and total phosphorus. The microplastics were dominated by fiber, 100-1000 μm in size and cellophane in composition. To our best knowledge, the microplastic levels measured in plankton net samples collected from Taihu Lake were the highest found in freshwater lakes worldwide. The ratio of the microplastics in clams to each sediment sample ranged from 38 to 3810 and was negatively correlated to the microplastic level in sediments. In brief, our results strongly suggest that high levels of microplastics occurred not only in water but also in organisms in Taihu Lake. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Three frequency false-color image of Prince Albert, Canada

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a three-frequency, false color image of Prince Albert, Canada, centered at 53.91 north latitude and 104.69 west longitude. It was produced using data from the X-band, C-band and L-band radars that comprise the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR). SIR-C/X-SAR acquired this image on the 20th orbit of the Shuttle Endeavour. The area is located 40 km north and 30 km east of the town of Prince Albert in the Saskatchewan province of Canada. The image covers the area east of the Candle Lake, between gravel surface highways 120 and 106 and west of 106. The area in the middle of the image covers the entire Nipawin (Narrow Hills) provincial park. Most of the dark blue areas in the image are the ice covered lakes. The dark area on the top right corner of the image is the White Gull Lake north of the intersection of highway 120 and 913. The right middle part of the image shows Lake Ispuchaw and Lower Fishing Lake. The deforested areas are shown by light

  17. Calculation of area and volume for the south part of Great Salt Lake, Utah

    USGS Publications Warehouse

    Baskin, Robert L.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the Utah Department of Natural Resources, Division of Wildlife Resources, collected bathymetric data for the south part of Great Salt Lake during 2002-04 using a single-beam, high-definition fathometer and real-time differential global positioning system. About 7.6 million depth measurements were collected along more than 930 miles (1,690 kilometers) of survey transects. Sound-velocity profiles were obtained in conjunction with the bathymetric data to provide time-of-travel corrections to the depth calculations. Data were processed with commercial hydrographic software and exported into geographic information system (GIS) software for mapping and calculation of area and volume. Area and volume calculations show a maximum area of about 508,000 acres (2,056 square kilometers) and a maximum volume of about 9,257,000 acre-feet (11.42 cubic kilometers) at a water-surface altitude of 4,200 feet (1,280 meters). Minimum water-surface altitude of the south part of Great Salt Lake is just below 4,167 feet (1,279 meters) in the area just south of the Union Pacific railroad causeway halfway between Promontory Point and the western edge of the lake. At this altitude, and continuing up to about 4,176 feet (1,279 meters), the south part of the lake is separated into two areas by a ridge extending from Promontory Point to Hat Island. Calculations for area and volume are based on a low altitude of 4,167 feet (1,279 meters) to a high altitude of 4,200 feet (1,280 meters).

  18. Soil surface lowering due to soil erosion in villages near Lake Victoria, Uganda

    NASA Astrophysics Data System (ADS)

    de Meyer, A.; Deckers, J.; Poesen, J.; Isabirye, M.

    2009-04-01

    In the effort to pinpoint the sources of sediment pollution in Lake Victoria, the contribution of sedi-ment from compounds, landing sites, main roads and footpaths is determined in the catchment of Na-bera Bay and Kafunda Bay at the northern shore of Lake Victoria in southern Uganda. The amount of soil loss in compounds and landing sites is determined by the reconstruction of the original and current soil surface according to botanical and man-made datable objects. The soil erosion rate is then deter-mined by dividing the eroded soil volume (corrected for compaction) by the age of the oldest datable object. In the study area, the average soil erosion rate in compounds amounts to 107 Mg ha-1 year-1 (per unit compound) and in landing sites to 207 Mg ha-1 year-1 (per unit landing site). Although com-pounds and landing sites occupy a small area of the study area (1.1 %), they are a major source of sediment to Lake Victoria (63 %). The soil loss on footpaths and main roads is calculated by multip-lying the total length of footpaths and main roads with the average width and depth (measured towards a reference surface). After the correction for compaction is carried out, the soil erosion rate on foot-paths amounts to 34 Mg ha-1 year-1 and on main roads to 35 Mg ha-1 year-1. Also footpaths and main roads occupy a small area of the study area (1.1 %), but contribute disproportionately to the total soil loss in the catchment (22 %). In this research, the information about the village/compound given by the villager/owner is indispensable. In accordance to an adaptation of the model of McHugh et al. (2002), 32 % of the sediment that is generated in the catchment, is deposited in Lake Victoria (i.e. 2 209 Mg year-1 or 0.7 Mg ha-1 year-1). The main buffer in the study area is papyrus at the shore of Lake Victoria. Also sugarcane can be a major buffer. However, the sugarcane-area is intersected by com-pounds, landing sites, footpaths and main roads that generate large amounts of sediment and function as main bypass mechanisms (high CR) facilitating and enhancing sediment delivery to Lake Victoria.

  19. Rapid Expansion of Glacial Lakes Caused by Climate and Glacier Retreat in the Central Himalayas

    NASA Astrophysics Data System (ADS)

    Wang, W.

    2016-12-01

    Glacial lake outburst floods are among the most serious natural hazards in the Himalayas. Such floods are of high scientific and political importance because they exert trans-boundary impacts on bordering countries. The preparation of an updated inventory of glacial lakes and the analysis of their evolution are an important first step in assessment of hazards from glacial lake outbursts. Here, we report the spatiotemporal developments of the glacial lakes in the Poiqu River basin, a trans-boundary basin in the Central Himalayas, from 1976 to 2010 based on multi-temporal Landsat images. Studied glacial lakes are classified as glacierfed lakes and non-glacier-fed lakes according to their hydrologic connection to glacial watersheds. A total of 119 glacial lakes larger than 0.01 km2 with an overall surface area of 20.22 km2 (±10.8%) were mapped in 2010, with glacier-fed lakes being predominant in both number (69, 58.0%) and area (16.22 km2, 80.2%). We found that lakes connected to glacial watersheds (glacier-fed lakes) significantly expanded (122.1%) from 1976 to 2010, whereas lakes not connected to glacial watersheds (non-glacier-fed lakes) remained stable (+2.8%) during the same period. This contrast can be attributed to the impact of glaciers. Retreating glaciers not only supply meltwater to lakes but also leave space for them to expand. Compared with other regions of the Hindu Kush Himalayas (HKH), the lake area per glacier area in the Poiqu River basin was the highest. This observation might be attributed to the different climate regimes and glacier status along the HKH. The results presented in this study confirm the significant role of glacier retreat on the evolution of glacial lakes.

  20. Impacts of Agricultural Practices and Tourism Activities on the Sustainability of Telaga Warna and Telaga Pengilon Lakes, Dieng Plateau, Central Java

    NASA Astrophysics Data System (ADS)

    Sudarmadji; Pudjiastuti, Hermin

    2018-02-01

    Telaga Warna and Telaga Pengilon are two volcanic lakes in the Dieng Plateau offer some unique phenomena which are interested for tourists to visit. Telaga Warna and Telaga Pengilon are located side by side in the Dieng Palteau. Those two lakes also have specific ecosystem which differ to other lakes. However as land use in the surrounding area is now gradually changing, the lake is now facing to environmental degradation. The land use in the surrounding area is for intensive agricultural which main crops are vegetable, especially potatoes. Meanwhile, the number of tourist visiting those two lakes is increasing; it may also give some impact to the lake environment. This research aims to study the impacts of agricultural practices and tourism activities to the lake environmental which lead to the environment sustainability of the lakes. The field survey was conducted to collect some data on lakes characteristics, agricultural and tourism activities. Some interviews to local people and tourists were also conducted. Some water and sediment samples were collected followed by laboratory analyses. Some secondary data from previous study was also collected. Data analysis was conducted based on qualitative and quantitative techniques. The study found that agricultural practices of potatoes plantation uses water from the Telaga Pengilon to irrigate the plant by pumping out the water using water pump and distributes the water over the plantation area. Agricultural practices lead to soil erosion, which contribute sediment to the lake carried by surface runoff. Therefore, the volume of lakes is gradually decreasing. The use of fertilizer in the agricultural practice contribute nutrient into the lake carried by surface runoff, leading to the eutrophication, due to the excess used of fertilizer. The study concludes that agricultural practices and tourism activities have some positive economic impacts to the local community, however it also give some adverse affects on the lakes, both quantitatively and qualitatively. The volume of lakes is gradually decreasing due to sedimentation. In the long term periods the lake may not be interesting object for tourism.

  1. Using dual isotopes to evaluate sources and transformations of nitrate in the West Lake watershed, eastern China

    NASA Astrophysics Data System (ADS)

    Jin, Zanfang; Qin, Xue; Chen, Lingxiao; Jin, Mantong; Li, Feili

    2015-06-01

    The West Lake is a World Heritage site in the West Lake watershed in eastern China. In this study, the hydrogeological and dual isotopic approaches were integrated to evaluate the seasonal and spatial variations of nitrate (NO3-) in the West Lake watershed, and to characterize NO3- sources and transformations. The results revealed that the geochemical facies of the water samples were dominated by Ca2 + + Na+-HCO3- + SO42- in the surface water and transfer water, Ca2 + + Na+-HCO3- and Ca2 + + Na+-SO42 - in the groundwater, which most likely reflect natural reactions and anthropogenic inputs. About 13% of the groundwater samples containing NO3- exceeded the World Health Organization (WHO) standard of 10 mg N L- 1. NO3- was the dominant form of total nitrogen (TN) and was the main surface water contaminant in the West Lake watershed. The δ15NNO3 and δ18ONO3 values indicated that the dominant NO3- sources in surface water were soil nitrogen (soil N) and chemical fertilizers, while the main NO3- sources in groundwater were soil N from the forest, chemical fertilizers and manure in the tea garden, domestic sewage from the small, old residential area in the forest as well as urban areas. The distribution of NO3- in groundwater was strongly influenced by land use. Results also suggest that there was significant nitrification in surface water and groundwater in the West Lake watershed, and that there were also denitrification processes in groundwater. The annual net fluxes of TN, NO3-, and NH4+ into the West Lake were 2.0 × 104, 4.0 × 103, and 1.31 × 104 kg as N, respectively.

  2. Impacts of flamingos on saline lake margin and shallow lacustrine sediments in the Kenya Rift Valley

    NASA Astrophysics Data System (ADS)

    Scott, Jennifer J.; Renaut, Robin W.; Owen, R. Bernhart

    2012-11-01

    Studies of modern, Holocene, and Pleistocene sediments around saline to hypersaline, alkaline Lake Bogoria and Lake Magadi show that evidence of flamingo activity in marginal areas of these lakes is nearly ubiquitous. Flamingos produce discrete structures such as webbed footprints (~ 9 cm long, ~ 11 cm wide) and nest mounds (~ 30 cm wide, ~ 20 cm high), and they also extensively rework sediments in delta front, delta plain, and shoreline areas. Large (~ 0.5-2 cm in diameter), pinched, 'bubble pores' and ped-like mud clumps are formed by the trampling and churning of wet clay-rich sediments in these settings. Flamingo nest mounds, although superficially similar to some thrombolite mounds, are typically internally structureless, unless formed on pre-existing sediments that preserve internal structures. The flamingo mounds consist of a dense, packed oval-shaped core, a surrounding 'body' of packed sediment, and an external layer with a ped-like texture of clumped mud. The nests may contain open holes from roots or feather shafts incorporated into the nest, and (or) burrows produced once the nests are abandoned. In areas with high densities of flamingos, lake margin sediments may be preferentially compacted, particularly at breeding sites, and become resistant to subaerial erosion and the effects of transgressive ravinement on time scales ranging from seasons to tens of thousands of years. The relatively well-compacted nest mounds and associated sediments also contribute to the stability of delta distributary channels during regressive-transgressive cycles, and can lead to the minor channelization of unconfined flows where currents are diverted around nest mounds. Pleistocene exhumed surfaces of relatively well-indurated lake margin sediments at Lake Bogoria and Lake Magadi that are interpreted as combined regressive and transgressive surfaces (flooding surface/sequence boundary) preserve evidence of flamingo activities, and are overlain by younger, porous lacustrine silts that preserve large bubble pores produced by flamingos.

  3. Remotely Sensing Lake Water Volumes on the Inner Arctic Coastal Plain of Northern Alaska

    NASA Astrophysics Data System (ADS)

    Simpson, C. E.; Arp, C. D.; Jones, B. M.; Hinkel, K. M.; Carroll, M.; Smith, L. C.

    2017-12-01

    Thermokarst lake depth is controlled by the amount of excess ice in near-surface permafrost, with lake depths of about 1 - 3 m in areas of epigenetic permafrost and over 10 m in areas of syngenetic permafrost. An important exception to these general patterns is found on the inner Arctic Coastal Plain (ACP) of northern Alaska, where deep lakes occur in Pleistocene-aged, ground-ice poor sandy terrain. These lakes cover 20% of the currently inactive sand sheet and dune deposit (referred to as the Pleistocene Sand Sea) that comprises approximately 7000 km2 of the ACP. Surrounded by high and eroding bluffs, sand sea lakes lie in natural depressions and are characterized by wide, shallow littoral shelves and central troughs that are typically oriented NNW to SSE and can reach depths greater than 20 m. Despite their unique form and extensive coverage, these lakes have received little prior study and a literature gap remains regarding regional water storage. This research classifies sand sea lakes, estimates individual lake volume, and provides a first quantification of water storage in a region of the lake-dominated ACP. We measured bathymetric profiles in 19 sand sea lakes using a sonar recorder to capture various lake depth gradients. Bathymetric surveys collected by oil industry consultants, lake monitoring programs, and habitat studies serve as additional datasets. These field measured lake depth data points were used to classify Color Infrared Photography, WorldView-2 satellite imagery, and Landsat-OLI satellite imagery to develop a spectral depth-classification algorithm and facilitate the interpolation of the bathymetry for study lakes in the inner ACP. Finally, we integrate the remotely sensed bathymetry and imagery-derived lake surface area to estimate individual and regional-scale lake volume. In addition to the natural function of these lakes in water storage, energy balance, and habitat provision, the need for winter water supply to build ice roads for oil exploration and development makes lakes in this region an increasingly valuable resource and knowledge of their storage essential. Estimating regional and lake-by-lake water volume will facilitate better management of expanding development activities and serve as a baseline by which to evaluate future responses to ongoing climate change in the Arctic.

  4. Hydrology of Lake Butler, Orange County, Florida

    USGS Publications Warehouse

    Smoot, James L.; Schiffer, Donna M.

    1984-01-01

    Lake Butler is one of the lakes that collectively make up the Butler chain of lakes in the headwaters of the Kissimmee River, Florida. The bottom configuration of the lake is typical of relict karst features formed during lower stages in sea level. The top of the Floridan aquifer is 50 to 100 feet below the land surface. The drainage area of Lake Butler is approximately 14.5 sq mi and is comprised of sub-basins of other lakes in the vicinity. Surface outflow from Lake Butler is generally southward to Cypress Creek, a tributary of the Kissimmee River. The extremes in lake stage for the period 1933-81 are 94.67 ft on June 23, 1981 and 101.78 ft on September 13, 1960. The median lake stage for this period was 99.28 ft above sea level. The quality of water in Lake Butler is excellent, based on studies of physical, chemical, and biological conditions by the Orange County Pollution Control Department. The lake water is slightly acidic and soft (48 mg/L hardness as calcium carbonate). Pesticides in water were below detection levels at two sites sampled in the lake, but were detected in the bottom sediments. (USGS)

  5. Ground-water and surface-water flow and estimated water budget for Lake Seminole, southwestern Georgia and northwestern Florida

    USGS Publications Warehouse

    Dalton, Melinda S.; Aulenbach, Brent T.; Torak, Lynn J.

    2004-01-01

    Lake Seminole is a 37,600-acre impoundment formed at the confluence of the Flint and Chattahoochee Rivers along the Georgia?Florida State line. Outflow from Lake Seminole through Jim Woodruff Lock and Dam provides headwater to the Apalachicola River, which is a major supply of freshwater, nutrients, and detritus to ecosystems downstream. These rivers,together with their tributaries, are hydraulically connected to karst limestone units that constitute most of the Upper Floridan aquifer and to a chemically weathered residuum of undifferentiated overburden. The ground-water flow system near Lake Seminole consists of the Upper Floridan aquifer and undifferentiated overburden. The aquifer is confined below by low-permeability sediments of the Lisbon Formation and, generally, is semiconfined above by undifferentiated overburden. Ground-water flow within the Upper Floridan aquifer is unconfined or semiconfined and discharges at discrete points by springflow or diffuse leakage into streams and other surface-water bodies. The high degree of connectivity between the Upper Floridan aquifer and surface-water bodies is limited to the upper Eocene Ocala Limestone and younger units that are in contact with streams in the Lake Seminole area. The impoundment of Lake Seminole inundated natural stream channels and other low-lying areas near streams and raised the water-level altitude of the Upper Floridan aquifer near the lake to nearly that of the lake, about 77 feet. Surface-water inflow from the Chattahoochee and Flint Rivers and Spring Creek and outflow to the Apalachicola River through Jim Woodruff Lock and Dam dominate the water budget for Lake Seminole. About 81 percent of the total water-budget inflow consists of surface water; about 18 percent is ground water, and the remaining 1 percent is lake precipitation. Similarly, lake outflow consists of about 89 percent surface water, as flow to the Apalachicola River through Jim Woodruff Lock and Dam, about 4 percent ground water, and about 2 percent lake evaporation. Measurement error and uncertainty in flux calculations cause a flow imbalance of about 4 percent between inflow and outflow water-budget components. Most of this error can be attributed to errors in estimating ground-water discharge from the lake, which was calculated using a ground-water model calibrated to October 1986 conditions for the entire Apalachicola?Chattahoochee?Flint River Basin and not just the area around Lake Seminole. Evaporation rates were determined using the preferred, but mathematically complex, energy budget and five empirical equations: Priestley-Taylor, Penman, DeBruin-Keijman, Papadakis, and the Priestley-Taylor used by the Georgia Automated Environmental Monitoring Network. Empirical equations require a significant amount of data but are relatively easy to calculate and compare well to long-term average annual (April 2000?March 2001) pan evaporation, which is 65 inches. Calculated annual lake evaporation, for the study period, using the energy-budget method was 67.2 inches, which overestimated long-term average annual pan evaporation by 2.2 inches. The empirical equations did not compare well with the energy-budget method during the 18-month study period, with average differences in computed evaporation using each equation ranging from 8 to 26 percent. The empirical equations also compared poorly with long-term average annual pan evaporation, with average differences in evaporation ranging from 3 to 23 percent. Energy budget and long-term average annual pan evaporation estimates did compare well, with only a 3-percent difference between estimates. Monthly evaporation estimates using all methods ranged from 0.7 to 9.5 inches and were lowest during December 2000 and highest during May 2000. Although the energy budget is generally the preferred method, the dominance of surface water in the Lake Seminole water budget makes the method inaccurate and difficult to use, because surface water makes up m

  6. Air-Water Exchange of Legacy and Emerging Organic Pollutants across the Great Lakes

    NASA Astrophysics Data System (ADS)

    Lohmann, R.; Ruge, Z.; Khairy, M.; Muir, D.; Helm, P.

    2014-12-01

    Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are transported to great water bodies via long-range atmospheric transport and released from the surface water as air concentrations continue to diminish. As the largest fresh water bodies in North America, the Great Lakes have both the potential to accumulate and serve as a secondary source of persistent bioaccumulative toxins. OCP and PCB concentrations were sampled at 30+ sites across Lake Superior, Ontario and Erie in the summer of 2011. Polyethylene passive samplers (PEs) were simultaneously deployed in surface water and near surface atmosphere to determine air-water gaseous exchange of OCPs and PCBs. In Lake Superior, surface water and atmospheric concentrations were dominated by α-HCH (average 250 pg/L and 4.2 pg/m3, respectively), followed by HCB (average 17 pg/L and 89 pg/m3, respectively). Air-water exchange varied greatly between sites and individual OCPs, however α-endosulfan was consistently deposited into the surface water (average 19 pg/m2/day). PCBs in the air and water were characterized by penta- and hexachlorobiphenyls with distribution along the coast correlated with proximity to developed areas. Air-water exchange gradients generally yielded net volatilization of PCBs out of Lake Superior. Gaseous concentrations of hexachlorobenzene, dieldrin and chlordanes were significantly higher (p < 0.05) at Lake Erie than Lake Ontario. A multiple linear regression that incorporated meteorological, landuse and population data was used to explain variability in the atmospheric concentrations. Results indicated that landuse (urban and/or cropland) greatly explained the variability in the data. Freely dissolved concentrations of OCPs (

  7. Water resources of Sleeping Bear Dunes National Lakeshore, Michigan

    USGS Publications Warehouse

    Handy, A.H.; Stark, J.R.

    1984-01-01

    Sleeping Bear Dunes National Lakeshore in a water-rich area. It borders Lake Michigan and several small streams flow through the park to the lake. Small lakes are numerous within the park and near its boundaries. Ground water is available at most places in the park and wells yield as much as 100 gallons per minute. Water from streams, lakes, wells, and springs is of good quality. Dissolved solids range from 35 to 180 mg/L in lakes, from 145 to 214 mg/L in streams, and from 136 to 468 mg/L in groundwater. Analyses of samples for pesticides and trace metals indicate that no pesticides are present in the water, and that concentrations of trace metals do not exceed recommended drinking-water standards. Surface and ground water are available in sufficient quantity in most areas of the park for the development of water supplies for visitor 's centers, campgrounds, picnic areas, and other park facilities.

  8. Procedural Documentation and Accuracy Assessment of Bathymetric Maps and Area/Capacity Tables for Small Reservoirs

    USGS Publications Warehouse

    Wilson, Gary L.; Richards, Joseph M.

    2006-01-01

    Because of the increasing use and importance of lakes for water supply to communities, a repeatable and reliable procedure to determine lake bathymetry and capacity is needed. A method to determine the accuracy of the procedure will help ensure proper collection and use of the data and resulting products. It is important to clearly define the intended products and desired accuracy before conducting the bathymetric survey to ensure proper data collection. A survey-grade echo sounder and differential global positioning system receivers were used to collect water-depth and position data in December 2003 at Sugar Creek Lake near Moberly, Missouri. Data were collected along planned transects, with an additional set of quality-assurance data collected for use in accuracy computations. All collected data were imported into a geographic information system database. A bathymetric surface model, contour map, and area/capacity tables were created from the geographic information system database. An accuracy assessment was completed on the collected data, bathymetric surface model, area/capacity table, and contour map products. Using established vertical accuracy standards, the accuracy of the collected data, bathymetric surface model, and contour map product was 0.67 foot, 0.91 foot, and 1.51 feet at the 95 percent confidence level. By comparing results from different transect intervals with the quality-assurance transect data, it was determined that a transect interval of 1 percent of the longitudinal length of Sugar Creek Lake produced nearly as good results as 0.5 percent transect interval for the bathymetric surface model, area/capacity table, and contour map products.

  9. Bathymetric Contour Maps of Lakes Surveyed in Iowa in 2005

    USGS Publications Warehouse

    Linhart, S.M.; Lund, K.D.

    2008-01-01

    The U.S. Geological Survey, in cooperation with the Iowa Department of Natural Resources, conducted bathymetric surveys on seven lakes in Iowa during 2005 (Arrowhead Pond, Central Park Lake, Lake Keomah, Manteno Park Pond, Lake Miami, Springbrook Lake, and Yellow Smoke Lake). The surveys were conducted to provide the Iowa Department of Natural Resources with information for the development of total maximum daily load limits, particularly for estimating sediment load and deposition rates. The bathymetric surveys provide a baseline for future work on sediment loads and deposition rates for these lakes. All of the lakes surveyed in 2005 are man-made lakes with fixed spillways. Bathymetric data were collected using boat-mounted, differential global positioning system, echo depth-sounding equipment, and computer software. Data were processed with commercial hydrographic software and exported into a geographic information system for mapping and calculating area and volume. Lake volume estimates ranged from 47,784,000 cubic feet (1,100 acre-feet) at Lake Miami to 2,595,000 cubic feet (60 acre-feet) at Manteno Park Pond. Surface area estimates ranged from 5,454,000 square feet (125 acres) at Lake Miami to 558,000 square feet (13 acres) at Springbrook Lake.

  10. Map showing flood and surface water information in the Sugar House quadrangle, Salt Lake County, Utah

    USGS Publications Warehouse

    Van Horn, Richard; Fields, F.K.

    1974-01-01

    In the past man has built on land that might be covered by floodwaters, with little consideration of the consequences. The result has been disastrous to those in the path of floodwaters and has cost the loss of thousands of lives and untold billions of dollars in property damage in the United States. Salt Lake County, of which the Sugar House quadrangle is a part, has had many floods in the past and can be expected to have more in the future. Construction has taken place in filled or dried-up marshes and lakes, in spring areas, and even in stream channels. Lack of prior knowledge of these and other forms of surface water (water at the surface of the ground) can increase construction and maintenance costs significantly.The map shows the area that probably will be covered by floods at least once in every 100 years on the long-term average (unit IRF, intermediate regional flood), the area that probably will be covered by floods from the worst possible combination of very wet weather and high streamflow reasonably expected of the area (unit SPF, standard project flood), the mapped extent of streamflow by channel shifting or flooding in the past 5,000 years (unit fa), and the probable maximum extent of damaging flash floods and mudflows from small valleys in the Wasatch Range. The map also shows the location of water at the surface of the ground: lakes, streams, springs, weep holes, canals, and reservoirs. Lakes and marshes that existed within the past 100 years, but now are drained, filled, or dried up, are also shown.The following examples show that the presence of water can be desirable or undesirable, depending on how the water occurs. Floods, the most spectacular form of surface water, may result in great property damage and loss of life. Lakes normally are beneficial, in that they may support plant growth and provide habitats for fish and other wildlife, provide water for livestock, and can be used for recreation. Springs may or may not be desirable: they may provide a source of water for domestic or stock use but are undesirable if they appear in a foundation excavation for a building. Thus, the location of areas that may be affected by floods and other surface water is important to people concerned with land-use planning, zoning, and legislation, and with the environment in which we must live.

  11. Spatial distribution and risk assessment of heavy metals and As pollution in the sediments of a shallow lake.

    PubMed

    Deng, Jiancai; Wang, Yuansheng; Liu, Xin; Hu, Weiping; Zhu, Jinge; Zhu, Lin

    2016-05-01

    The concentrations and spatial distributions of eight heavy metals in surface sediments and sediment core samples from a shallow lake in China were investigated to evaluate the extent of the contamination and potential ecological risks. The results showed that the heavy metal concentrations were higher in the northern and southwestern lake zones than those in the other lake zones, with lower levels of As, Hg, Zn, Cu, Pb, Cr, and Ni primarily observed in the central and eastern lake regions and Cd primarily confined to areas surrounding the lake. The concentrations of the eight heavy metals in the sediment profiles tended to decrease with increasing sediment depth. The contents of Ni, Cu, Zn, Pb, and Cd in the surface sediment were approximately 1.23-18.41-fold higher than their background values (BVs), whereas the contents of Cr, As, and Hg were nearly identical to their BVs. The calculated pollution load index (PLI) suggested that the surface sediments of this lake were heavily polluted by these heavy metals and indicated that Cd was a predominant contamination factor. The comprehensive potential ecological risk index (PERI) in the surface sediments ranged from 99.2 to 2882.1, with an average of 606.1. Cd contributed 78.7 % to the PERI, and Hg contributed 8.4 %. Multivariate statistical analyses revealed that the surface sediment pollution with heavy metals mainly originated from industrial wastewater discharged by rivers located in the western and northwestern portion of the lake.

  12. Predicting future glacial lakes in Austria using different modelling approaches

    NASA Astrophysics Data System (ADS)

    Otto, Jan-Christoph; Helfricht, Kay; Prasicek, Günther; Buckel, Johannes; Keuschnig, Markus

    2017-04-01

    Glacier retreat is one of the most apparent consequences of temperature rise in the 20th and 21th centuries in the European Alps. In Austria, more than 240 new lakes have formed in glacier forefields since the Little Ice Age. A similar signal is reported from many mountain areas worldwide. Glacial lakes can constitute important environmental and socio-economic impacts on high mountain systems including water resource management, sediment delivery, natural hazards, energy production and tourism. Their development significantly modifies the landscape configuration and visual appearance of high mountain areas. Knowledge on the location, number and extent of these future lakes can be used to assess potential impacts on high mountain geo-ecosystems and upland-lowland interactions. Information on new lakes is critical to appraise emerging threads and potentials for society. The recent development of regional ice thickness models and their combination with high resolution glacier surface data allows predicting the topography below current glaciers by subtracting ice thickness from glacier surface. Analyzing these modelled glacier bed surfaces reveals overdeepenings that represent potential locations for future lakes. In order to predict the location of future glacial lakes below recent glaciers in the Austrian Alps we apply different ice thickness models using high resolution terrain data and glacier outlines. The results are compared and validated with ice thickness data from geophysical surveys. Additionally, we run the models on three different glacier extents provided by the Austrian Glacier Inventories from 1969, 1998 and 2006. Results of this historical glacier extent modelling are compared to existing glacier lakes and discussed focusing on geomorphological impacts on lake evolution. We discuss model performance and observed differences in the results in order to assess the approach for a realistic prediction of future lake locations. The presentation delivers intermediate results from the FUTURELAKES project, which aims at generating the first nation-wide data set on future glacial lakes in Austria.

  13. Water resources of the Lake Traverse Reservation, South and North Dakota, and Roberts County, South Dakota

    USGS Publications Warehouse

    Thompson, Ryan F.

    2001-01-01

    In 1994, the U.S. Geological Survey, in cooperation with the Sisseton-Wahpeton Sioux Tribe; Roberts County; and the South Dakota Department of Environment and Natural Resources, Geological Survey Program, began a 6-year investigation to describe and quantify the water resources of the area within the 1867 boundary of the Lake Traverse Reservation and adjacent parts of Roberts County. Roberts County is located in extreme northeastern South Dakota, and the 1867 boundary of the Lake Traverse Reservation encompasses much of Roberts County and parts of Marshall, Day, Codington, and Grant Counties in South Dakota and parts of Richland and Sargent Counties in southeast North Dakota. This report includes descriptions of the quantity, quality, and availability of surface and ground water, the extent of the major glacial and bedrock aquifers and named outwash groups, and surface- and ground-water uses within the 1867 boundary of the Lake Traverse Reservation and adjacent parts of Roberts County. The surface-water resources within the 1867 boundary of the Lake Traverse Reservation and adjacent parts of Roberts County include rivers, streams, lakes, and wetlands. The Wild Rice and Bois de Sioux Rivers are tributaries of the Red River within the Souris-Red-Rainy River Basin; the Little Minnesota, Jorgenson, and North Fork Whetstone Rivers are tributaries of the Minnesota River within the Upper Mississippi River Basin, and the James and Big Sioux Rivers are tributaries within the Missouri River Basin. Several of the larger lakes within the study area have been developed for recreation, while many of the smaller lakes and wetlands are used for livestock watering or as wildlife production areas. Statistical summaries are presented for the water-quality data of six selected streams within the study area, and the dominant chemical species are listed for 17 selected lakes within the study area. The glacial history of the study area has led to a rather complex system of glacial aquifers. The boundaries of 11 aquifers and 6 named outwash groups were delineated based on hydrogeologic cross sections, water levels, and water-quality similarities/dissimilarities. The glacial aquifers include Coteau Lakes system, Big Sioux, Alta-mont, Revillo, James, Veblen system, Spiritwood, Hankinson, Rosholt, Milnor Channel, and Fairmount; the bedrock aquifer included in this report is the Dakota. Named outwash groups include the Prairie Coteau, Lonesome Lake, Marday, Eden, Roslyn, and Wilmot. A summary of the character-istics of each of the major aquifers and outwash groups and a summary of selected chemical analyses for each aquifer and outwash group are presented. All aquifers and outwash groups in the study area have either moderately hard or very hard water and are considered fresh to slightly saline. One or more water samples from some of the aquifers and outwash groups have a constituent that was above the recommended or mandatory limit for drinking water. Most aquifers and outwash groups have dissolved solids and sulfate contents above the recommended levels of 500 and 250 mg/L (milligrams per liter), respectively. The Dakota aquifer was the only one to have a mean chloride concentration above the recommended level of 250 mg/L. Nitrate concentrations greater than the mandatory limit of 10 mg/L were found in the Big Sioux aquifer and the Coteau Lakes and Veblen aquifer systems. Concentrations of arsenic greater than 10 ?g/L (micrograms per liter) were found in the Coteau Lakes and Veblen aquifer systems, and in the Rosholt and Fairmount aquifers. Municipalities and rural water systems currently provide most of the water used in the study area-nearly all of it from ground-water sources. Surface-water use is limited to livestock watering. About 55 percent of the total water used in Roberts County is for domestic purposes, with most domestic users served by a public supply system. Irrigation accounts for about 10 percent of the total water used. All

  14. Geophysical Investigation of a Thermokarst Lake Talik in Continuous Permafrost

    NASA Astrophysics Data System (ADS)

    Creighton, A.; Parsekian, A.; Arp, C. D.; Jones, B. M.; Babcock, E.; Bondurant, A. C.

    2016-12-01

    On the Arctic Coastal Plain (ACP) of northern Alaska, shallow thermokarst lakes cover up to 25% of the landscape. These lakes occupy depressions created by the subsidence of thawed, ice-rich permafrost. Areas of unfrozen sediment, or taliks, can form under lakes that have a mean annual bottom temperature greater than 0°C. The geometry of these taliks, as well as the processes that create them, are important for understanding interactions between surface water, groundwater, and carbon cycling. Non-invasive geophysical methods are a useful means to study talik sediments as borehole studies yield few data points, and the contrast between unfrozen and frozen sediments is an ideal geophysical target. To study talik configuration associated with an actively expanding thermokarst lake, we conducted a geophysical transect across Peatball Lake. This lake has an estimated initiation age of 1400 calendar years BP. Over the past 60 years, lake surface area has increased through thermal and mechanical shoreline erosion. A talik of previously unknown thickness likely exists below Peatball Lake. We conducted a transect of transient electromagnetic soundings across the lake extending into the surrounding terrestrial environment. Since permafrost has relatively high resistivity compared to talik sediments, the interpreted electrical structure of the subsurface likely reflects talik geometry. We also conducted nuclear magnetic resonance soundings at representative locations along the transect. These measurements can provide data on sub-lake sediment properties including water content. Together, these measurements resolve the talik structure across the lake transect and showed evidence of varying talik thicknesses from the lake edge to center. These is no evidence of a talik at the terrestrial control sites. These results can help constrain talik development models and thus provide insight into Arctic and permafrost processes in the face of a changing climate.

  15. Continuous Change Detection of Urban Lakes in Wuhan, China Using Multi-Temporal Remote Sensing Images

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Kong, X.; Tan, G.; Zheng, S.

    2018-04-01

    Urban lakes are important natural, scenic and pattern attractions of the city, and they are potential development resources as well. However, lots of urban lakes in China have been shrunk significantly or disappeared due to rapid urbanization. In this study, four Landsat images were used to perform a case study for lake change detection in downtown Wuhan, China, which were acquired on 1991, 2002, 2011 and 2017, respectively. Modified NDWI (MNDWI) was adopted to extract water bodies of urban areas from all these images, and OTSU was used to optimize the threshold selection. Furthermore, the variation of lake shrinkage was analysed in detail according to SVM classification and post-classification comparison, and the coverage of urban lakes in central area of Wuhan has decreased by 47.37 km2 between 1991 and 2017. The experimental results revealed that there were significant changes in the surface area of urban lakes over the 27 years, and it also indicated that rapid urbanization has a strong impact on the losses of urban water resources.

  16. Simulation of groundwater flow and interaction of groundwater and surface water on the Lac du Flambeau Reservation, Wisconsin

    USGS Publications Warehouse

    Juckem, Paul F.; Fienen, Michael N.; Hunt, Randall J.

    2014-01-01

    The Lac du Flambeau Band of Lake Superior Chippewa and Indian Health Service are interested in improving the understanding of groundwater flow and groundwater/surface-water interaction on the Lac du Flambeau Reservation (Reservation) in southwest Vilas County and southeast Iron County, Wisconsin, with particular interest in an understanding of the potential for contamination of groundwater supply wells and the fate of wastewater that is infiltrated from treatment lagoons on the Reservation. This report describes the construction, calibration, and application of a regional groundwater flow model used to simulate the shallow groundwater flow system of the Reservation and water-quality results for groundwater and surface-water samples collected near a system of waste-water-treatment lagoons. Groundwater flows through a permeable glacial aquifer that ranges in thickness from 60 to more than 200 feet (ft). Seepage and drainage lakes are common in the area and influence groundwater flow patterns on the Reservation. A two-dimensional, steady-state analytic element groundwater flow model was constructed using the program GFLOW. The model was calibrated by matching target water levels and stream base flows through the use of the parameter-estimation program, PEST. Simulated results illustrate that groundwater flow within most of the Reservation is toward the Bear River and the chain of lakes that feed the Bear River. Results of analyses of groundwater and surface-water samples collected downgradient from the wastewater infiltration lagoons show elevated levels of ammonia and dissolved phosphorus. In addition, wastewater indicator chemicals detected in three downgradient wells and a small downgradient stream indicate that infiltrated wastewater is moving southwest of the lagoons toward Moss Lake. Potential effects of extended wet and dry periods (within historical ranges) were evaluated by adjusting precipitation and groundwater recharge in the model and comparing the resulting simulated lake stage and water budgets to stages and water budgets from the calibrated model. Simulated lake water budgets and water level changes illustrate the importance of understanding the position of a lake within the hydrologic system (headwater or downstream), the type of lake (surface-water drainage or seepage lake), and the role of groundwater in dampening the effects of large-scale changes in weather patterns on lake levels. Areas contributing recharge to drinking-water supply wells on the Reservation were delineated using forward particle tracking from the water table to the well. Monte Carlo uncertainty analyses were used to produce maps showing the probability of groundwater capture for areas around each well nest. At the Main Pumphouse site near the Village of Lac du Flambeau, most of the area contributing recharge to the wells occurs downgradient from a large wetland between the wells and the wastewater infiltration lagoons. Nonetheless, a small potential for the wells to capture infiltrated wastewater is apparent when considering uncertainty in the model parameter values. At the West Pumphouse wells south of Flambeau Lake, most of the area contributing recharge is between the wells and Tippecanoe Lake. The extent of infiltrated wastewater from two infiltration lagoons was tracked using the groundwater flow model and Monte Carlo uncertainty analyses. Wastewater infiltrated from the lagoons flows predominantly south toward Moss Lake as it integrates with the regional groundwater flow system. The wastewater-plume-extent simulations support the area-contributing-recharge simulations, indicating that there is a possibility, albeit at low probability, that some wastewater could be captured by water-supply wells. Comparison of simulated water-table contours indicate that the lagoons may mound the water table approximately 4 ft, with diminishing levels of mounding outward from the lagoons. Four scenarios, representing potential alternatives for wastewater management, were simulated (at current discharge rates) to evaluate the potential extent of wastewater in the aquifer and discharge to surface-water bodies associated with each management scenario. Wastewater simulated to infiltrate through a hypothetical diffuser below a wetland south of the current lagoons appears to discharge to the overlying wetland and would likely discharge to Moss Lake as overland flow. Wastewater simulated to discharge to a small lake (Mindy Lake) between Moss and Fence Lakes appears to spread radically over a large area between the lakes. Wastewater simulated to discharge to lagoons south and northeast of the current lagoons also appears to spread radially, but the areas of the aquifer with the highest probability of encountering waste-water contamination would likely be between the lagoons and the nearest lake, where the wastewater would eventually discharge. Probability results for the wastewater-plume-extent scenarios are sensitive to the number of mathematical water particles used to represent infiltrating wastewater and the level of detail in the synthetic grid used for the probability analysis. Thus, probability results from wastewater-plume-extent simulations are qualitative only; however, it is expected that illustrations of relatively high or low probability will be useful as a general guide for decision making. Management problems requiring quantitative estimates of probability are best re-cast into problems evaluating the area that contributes recharge to the location of interest, which is not dependent upon the number of simulated particles or the resolution of a synthetic grid.

  17. Age and extent of a giant glacial-dammed lake at Yarlung Tsangpo gorge in the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Liu, Weiming; Lai, Zhongping; Hu, Kaiheng; Ge, Yonggang; Cui, Peng; Zhang, Xiaogang; Liu, Feng

    2015-10-01

    Many glacier dams on major rivers at the southeastern edge of the Tibetan Plateau had been previously determined through remote sensing and glacier terminal position calculation. It was hypothesized that such damming substantially impeded river incision into the plateau interior. Investigation on the large glacial-dammed lake at the entrance of Tsangpo gorge is critical for understanding this hypothesis. So far, the issues, such as age, lake surface elevation, and stages of this dammed lake, are still in debate. Our field survey of lacustrine deposits and loess distribution along the middle Yarlung Tsangpo River and its tributary, Nyang River, suggested that the lake surface elevation was at about 3180 m asl. The 23 quartz optically stimulated luminescence (OSL) and 4 organic AMS 14C ages all fall into the Last Glacial period ( 41-13 ka). The OSL and 14C ages are in general agreement with each other where applicable. There might be only one long damming event because the ages of lacustrine deposits from 2970 to 3100 m asl are similar, and every lacustrine section is sustained for a long time. The estimated lake surface area was 1089 km2, and the volume was 170 km3, which differ from previous estimations which suggested two-stage (about early Holocene and 1.5 ka) lakes, and the largest lake surface elevation reached 3500 m.

  18. The use of radar imagery for surface water investigations

    NASA Technical Reports Server (NTRS)

    Bryan, M. L.

    1981-01-01

    The paper is concerned with the interpretation of hydrologic features using L-band (HH) imagery collected by aircraft and Seasat systems. Areas of research needed to more precisely define the accuracy and repeatability of measurements related to the conditions of surfaces and boundaries of fresh water bodies are identified. These include: the definition of shoreline, the nature of variations in surface roughness across a water body and along streams and lake shores, and the separation of ambiguous conditions which appear similar to lakes.

  19. Calculation of area and volume for the north part of Great Salt Lake, Utah

    USGS Publications Warehouse

    Baskin, Robert L.

    2006-01-01

    The U.S. Geological Survey, in cooperation with the Utah Department of Natural Resources, Division of Forestry, Fire, and State Lands, collected bathymetric data for the north part of Great Salt Lake during the spring and early summer of 2006 using a single-beam, high-definition fathometer and real-time differential global positioning system. About 5.2 million depth measurements were collected along more than 765 miles (1,230 kilometers) of survey transects. Sound-velocity profiles were obtained in conjunction with the bathymetric data to provide time-of-travel corrections to the depth calculations. Data were processed with commercial hydrographic software and exported into geographic information system (GIS) software for mapping and calculation of area and volume. Area and volume calculations show a maximum area of about 385,000 acres (1,560 square kilometers) and a maximum volume of about 5,693,000 acre-feet (about 7 cubic kilometers) at a water-surface altitude of 4,200 feet (1,280 meters). Minimum natural water-surface altitude of the north part of Great Salt Lake is just below 4,167 feet (1,270 meters) in the area just north of the Union Pacific railroad causeway halfway between Saline and the western edge of the lake. The north part of Great Salt Lake generally grades gradually to the west and north and is bounded by steep scarps along its eastern border. Calculations for area and volume are based on a low altitude of 4,167 feet (1,270 meters) to a high altitude of 4,200 feet (1,280 meters).

  20. ERTS-B applications to Minnesota resource management

    NASA Technical Reports Server (NTRS)

    Sizer, J. E. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. The shape, pattern, and extent of surface water (e.g. lakes) can be readily mapped. Comparing detailed maps of several lakes in Itasca County with the areas classified as water by the LANDSAT data shows that some lakes have changed considerably since they were mapped. Due to several droughts this year (1976), the water level in most lakes has dropped. At this time, it seems feasible that LANDSAT digital tape data estimate lake water level change, due to the 1976 drought conditions.

  1. Applications of HCMM satellite data. [Lake Ontario, Buffalo, Syracuse, and Rochester, New York

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The thermal properties of Lake Ontario as they relate to water equality, lake hydrology and energy exchange were investigated as well as the urban heat island problem in selected areas adjacent to the lake. The HCMM thermal sensor was fully calibrated for several underflight data. Actual surface water temperature maps were generated for all of Lake Ontario using the calibration procedure developed. Major water quality changes associated with the thermal bar as located by HCMM thermal data were observed from satellite and aerial data and verified by ground truth.

  2. Ground-Water, Surface-Water, and Water-Chemistry Data, Black Mesa Area, Northeastern Arizona - 1998

    DTIC Science & Technology

    2000-01-01

    and Kayenta PM2, Black Mesa area, Arizona, 1982–98...The aquifer consists of three rock formations—the Navajo Sandstone, the Kayenta Formation, and the Lukachukai Member1 of the Wingate Sandstone...Brown and Eychaner (1988) 0 0 25 KILOMETERS 25 MILES Chinle 264 264 Tsegi Kayenta Red Lake Cow Springs Rocky Ridge Keams Canyon Forest Lake Kitsillie

  3. The global abundance and size distribution of lakes, ponds, and impoundments

    USGS Publications Warehouse

    Downing, J.A.; Prairie, Y.T.; Cole, J.J.; Duarte, C.M.; Tranvik, L.J.; Striegl, Robert G.; McDowell, W.H.; Kortelainen, Pirkko; Caraco, N.F.; Melack, J.M.; Middelburg, J.J.

    2006-01-01

    One of the major impediments to the integration of lentic ecosystems into global environmental analyses has been fragmentary data on the extent and size distribution of lakes, ponds, and impoundments. We use new data sources, enhanced spatial resolution, and new analytical approaches to provide new estimates of the global abundance of surface-water bodies. A global model based on the Pareto distribution shows that the global extent of natural lakes is twice as large as previously known (304 million lakes; 4.2 million km 2 in area) and is dominated in area by millions of water bodies smaller than 1 km2. Similar analyses of impoundments based on inventories of large, engineered dams show that impounded waters cover approximately 0.26 million km2. However, construction of low-tech farm impoundments is estimated to be between 0.1 % and 6% of farm area worldwide, dependent upon precipitation, and represents >77,000 km 2 globally, at present. Overall, about 4.6 million km2 of the earth's continental "land" surface (>3%) is covered by water. These analyses underscore the importance of explicitly considering lakes, ponds, and impoundments, especially small ones, in global analyses of rates and processes. ?? 2006, by the American Society of Limnology and Oceanography, Inc.

  4. False-color composite image of Prince Albert, Canada

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a false color composite of Prince Albert, Canada, centered at 53.91 north latitude and 104.69 west longitude. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on the 20th orbit of the Shuttle Endeavour. The area is located 40 km north and 30 km east of the town of Prince Albert in the Saskatchewan province of Canada. The image covers the area east of the Candle Lake, between gravel surface highways 120 and 106 and west of 106. The area in the middle of the image covers the entire Nipawin (Narrow Hills) provincial park. The look angle of the radar is 30 degrees and the size of the image is approximately 20 kilometers by 50 kilometers (12 by 30 miles). Most of the dark areas in the image are the ice-covered lakes in the region. The dark area on the top right corner of the image is the White Gull Lake north of the intersection of Highway 120 and 913. The right middle part of the image shows Lake Ispuchaw and Lower Fishing Lake

  5. Current status and historical variations of DDT-related contaminants in the sediments of Lake Chaohu in China and their influencing factors.

    PubMed

    Kang, Lei; He, Qi-Shuang; He, Wei; Kong, Xiang-Zhen; Liu, Wen-Xiu; Wu, Wen-Jing; Li, Yi-Long; Lan, Xin-Yu; Xu, Fu-Liu

    2016-12-01

    The temporal-spatial distributions of DDT-related contaminants (DDXs), including DDT (dichlorodiphenyltrichloroethane), DDE (dichlorodiphenyldichloroethylene) and DDD (dichlorodiphenyldichloroethane), in the sediments of Lake Chaohu and their influencing factors were studied. p,p-DDE and p,p-DDD were found to be the two dominant components of DDXs in both surface and core sediments. The parent DDT compounds were still detectable in sediment cores after the late 1930s. Historical usage of technical DDT was identified as the primary source of DDXs in sediments, as indicated by DDT/(DDD + DDE) ratios of less than one. The residual levels of DDXs were higher in the surface and core sediments in the western lake area than in other lake areas, which might be due to the combined inflow effects of municipal sewage, industrial wastewater and agricultural runoff. The DDX residues in the sediment cores reached peak values in the late 1970s or early 1980s. There were significant positive relationships between DDX residues in sediment cores with annual DDT production and with fine particulate sizes (<4.5 μm). The relationship between the DDXs and TOC in sediment was complex, as indicated by the significant differences among the surface and core sediments. The algae-derived organic matter significantly influenced the amount of residue, composition and distribution of DDXs in the sediments. The DDD/DDE ratios responded well to the anaerobic conditions in the sediments that were caused by algal blooms after the late 1970s in the western lake area. This suggests that the algae-derived organic matter was an important factor and served as a biomarker of eutrophication and also affected the DDX residues and lifecycle in the lake ecosystem. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. A Geomorphic Analysis of Floodplain Lakes along the Embanked Lower Mississippi River for Managing Hydrologic Connectivity

    NASA Astrophysics Data System (ADS)

    Hudson, Paul; Boot, Dax; Sounny-Slitinne, M. Anwar; Kristensen, Kristiaan

    2015-04-01

    A Geomorphic Analysis of Floodplain Lakes along the Embanked Lower Mississippi River for Managing Hydrologic Connectivity Floodplain lakes are vital to the environmental integrity of lowland rivers. Embankment by levees (dikes) for flood control greatly reduces the size of lowland floodplains and is detrimental to the quality and functioning of floodplain water bodies, presenting a challenge to government agencies charged with environmental management. The embanked floodplain of the Lower Mississippi River is an enormous surface which includes a variety of lake types formed by geomorphic and anthropogenic processes. While much is known about the channel and hydrologic regime, very little is known about the physical structure and functioning of the embanked floodplain of the lower Mississippi. Importantly, management agencies do not have an inventory of the basic characteristics (e.g., type, frequency, location, size, shape) of water bodies within the lower Mississippi embanked floodplain. An analysis of lakes along the Lower Mississippi River embanked floodplain is performed by utilizing the National Hydrographic Dataset (NHD) from the U.S. Geological Survey, a LiDAR digital elevation model (DEM), as well as streamflow data from the USGS. The vector NHD data includes every official mapped water body (blue line polygons) on USGS topographic maps at scales of 1:100,000 and 1:24,000. Collectively, we identify thousands of discreet water bodies within the embanked floodplain. Utilizing planimetric properties the water bodies were classified into the following lake types: cutoffs (neck and chute), sloughs, crevasse (scour), local drainage (topographic), and borrow pits. The data is then statistically analyzed to examine significant differences in the spatial variability in lake types along the entire lower Mississippi embanked floodplain in association with geomorphic divisions and hydrologic regime. The total embanked floodplain area of the LMR is 7,303 km2,. The total area of floodplain lakes within the embanked floodplain is 382 km2, or 5.2% of the embanked floodplain surface area. Considerable variability in embanked floodplain area along the lower Mississippi, however, results in spatial variability in the frequency of specific lake types. Meander cutoff lakes represent the largest proportion of lake area, at 49%, with approximately half of this area comprised of artificial cutoff lakes. The next largest class of lakes are borrow pit lakes (at 16%), which are anthropogenic water bodies created for the process of levee (dike) construction and maintenance, but which represent valuable environmental habitat. Meander cutoff lakes are especially dominant in the upper reaches of the Lower Mississippi and diminish moving downstream, where the area of embanked floodplain also decreases. Interestingly, anthropogenic lakes (borrow pits) become increasingly prevalent further downstream and dominate over natural formed lakes. The location of lake types along the Lower Mississippi does not correspond with recent historic geomorphic and hydrologic activity. The highest frequency of meander cutoff and crevasse lakes are not located within floodplain sections which historically had the highest rates of lateral migration (m/yr) and flooding (duration). Although overbank hydrologic connectivity varies along the river, it does not vary necessarily where it would be most advantageous to the connectivity of specific types of lakes. The research results provide government agencies with a spatial inventory and methodological approach to improve the management of floodplain water bodies for sustaining valuable aquatic habitat, whether by artificially restricting or enhancing hydrologic connectivity. Key words: floodplain lakes, fluvial geomorphology, hydrologic connectivity, anthropogenic impacts, Lower Mississippi River

  7. Geohydrology and limnology of Walden Pond, Concord, Massachusetts

    USGS Publications Warehouse

    Colman, John A.; Friesz, Paul J.

    2001-01-01

    The trophic ecology and ground-water contributing area of Walden Pond, in Concord and Lincoln, Mass., were investigated by the U.S. Geological Survey in cooperation with the Massachusetts Department of Environmental Management from April 1997 to July 2000. Bathymetric investigation indicated that Walden Pond (24.88 hectares), a glacial kettle-hole lake with no surface inlet or outlet, has three deep areas. The maximum depth (30.5 meters) essentially was unchanged from measurements made by Henry David Thoreau in 1846. The groundwater contributing area (621,000 square meters) to Walden Pond was determined from water-table contours in areas of stratified glacial deposits and from land-surface contours in areas of bedrock highs. Walden Pond is a flow-through lake: Walden Pond gains water from the aquifer along its eastern perimeter and loses water to the aquifer along its western perimeter. Walden Pond contributing area also includes Goose Pond and its contributing area. A water budget calculated for Walden Pond, expressed as depth of water over the lake surface, indicated that 45 percent of the inflow to the lake was from precipitation (1.215 meters per year) and 55 percent from ground water (1.47 meters per year). The groundwater inflow estimate was based on the average of two different approaches including an isotope mass-balance approach. Evaporation accounted for 26 percent of the outflow from the lake (0.71 meters per year) whereas lake-water seepage to the groundwater system contributed 74 percent of the outflow (1.97 meters per year). The water-residence time of Walden Pond is approximately 5 years. Potential point sources of nutrients to ground water, the Concord municipal landfill and a trailer park, were determined to be outside the Walden Pond groundwater contributing area. A third source, the septic leach field for the Walden Pond State Reservation facilities, was within the groundwater contributing area. Nutrient budgets for the lake indicated that nitrogen inputs (858 kilograms per year) were dominated (30 percent) by plume water from the septic leach field and, possibly, by swimmers (34 percent). Phosphorus inputs (32 kilograms per year) were dominated by atmospheric dry deposition, background ground water, and estimated swimmer inputs. Swimmer inputs may represent more than 50 percent of the phosphorus load during the summer. The septic-system plume did not contribute phosphorus, but increased the nitrogen to phosphorus ratio for inputs from 41 to 59, on an atom-to-atom basis. The ratio of nitrogen to phosphorus in input loads and within the lake indicated algal growth would be strongly phosphorus limited. Nitrogen supply in excess of plant requirements may mitigate against nitrogen fixing organisms including undesirable blooms of cyanobacteria. Based on areal nutrient loading, Walden Pond is a mesotrophic lake. Hypolimnetic oxygen demand of Walden Pond has increased since a profile was measured in 1939. Currently (1999), the entire hypolimnion of Walden Pond becomes devoid of dissolved oxygen before fall turnover in late November; whereas historical data indicated dissolved oxygen likely remained in the hypolimnion during 1939. The complete depletion of dissolved oxygen likely causes release of phosphorus from the sediments. Walden Pond contains a large population of the deep-growing benthic macro alga Nitella, which has been hypothesized to promote water clarity in other clear-water lakes by sequestering nutrients and keeping large areas of the sediment surface oxygenated. Loss of Nitella populations in other lakes has correlated with a decline in water quality. Although the Nitella standing crop is large in Walden Pond, Nitella still appears to be controlled by nutrient availability. Decreasing phosphorus inputs to Walden Pond, by amounts under anthropogenic control would likely contribute to the stability of the Nitella population in the metalimnion, may reverse oxygen depletion in the hypolimnion, and decreas

  8. Sedimentological, mineralogical, and geochemical results from surface sediments and the sediment record from Site 2 of the ICDP drilling project at Lake Towuti, Indonesia

    NASA Astrophysics Data System (ADS)

    Hasberg, A. K.; Melles, M.; Wennrich, V.; Vogel, H.; Just, J.; Russell, J. M.; Bijaksana, S.; Morlock, M.; Opitz, S.

    2017-12-01

    More than 1000 m of sediment core were recovered in spring 2015 from three different drill sites in tropical Lake Towuti (2.5°S, 121°E), Indonesia, during the Towuti Drilling Project (TDP) of the International Continental Scientific Drilling Program (ICDP). Furthermore, a set of 84 lake surface sediment samples, distributed over the entire lake, was collected in order to better understand modern sedimentary processes. The surface samples were investigated for physical, chemical, mineralogical, and biological properties at the University of Cologne (UoC), Germany. On the sediment cores macro- and microscopical lithological descriptions, line-scan imaging, logging of physical properties (MSCL), and subsampling was conducted at the National Lacustrine Core Facility of the University of Minnesota, USA, in November 2015 and January 2016. Afterwards, the archive core halves and 672 subsamples of TDP Site 2 were shipped to the UoC for X-Ray Fluorescence (XRF) scanning and sedimentological, geochemical, and mineralogical analyses, respectively, supplemented by visible to near-infrared spectroscopy (VNIR) at Brown University, USA. The data from the surface samples evidence that allochthonous sedimentation in Lake Towuti today is dominated by fluvial supply from five distinguishable source areas: (i) the Mahalona River to the north, which drains lakes Mahalona and Matano, (ii) inlets around the village of Timampu to the northwest, (iii) the Loeha River to the east, (iv) the Lengke River to the south, and (v) the Lemo-Lemo River to the northeast of Lake Towuti. Of these, source areas (ii) and (iii) as well as (iv) and (v) have similar geochemical compositions, respectively. In addition, the lake sedimentation is significantly influenced by gravitational sediment supply from steep slopes as well as lake-internal gravitational and density-driven processes. The uppermost 41 m of sediment core 2A consist of pelagic sediments (totaling 11 m) and event layers from mass movement ( 30 m) that were formed during the past 50 cal kyr. In this period, the data reflect significant climatic and environmental changes, in particular in precipitation and lake level. These changes seem to be coupled to prominent paleoclimatic events.

  9. Fluctuations of Lake Eyre, South Australia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lake Eyre is a large salt lake situated between two deserts in one of Australia's driest regions. However, this low-lying lake attracts run-off from one of the largest inland drainage systems in the world. The drainage basin is very responsive to rainfall variations, and changes dramatically with Australia's inter-annual weather fluctuations. When Lake Eyre fills,as it did in 1989, it is temporarily Australia's largest lake, and becomes dense with birds, frogs and colorful plant life. The Lake responds to extended dry periods (often associated with El Nino events) by drying completely.

    These four images from the Multi-angle Imaging SpectroRadiometer contrast the lake area at the start of the austral summers of 2000 and 2002. The top two panels portray the region as it appeared on December 9, 2000. Heavy rains in the first part of 2000 caused both the north and south sections of the lake to fill partially and the northern part of the lake still contained significant standing water by the time these data were acquired. The bottom panels were captured on November 29, 2002. Rainfall during 2002 was significantly below average ( http://www.bom.gov.au/ ), although showers occurring in the week before the image was acquired helped alleviate this condition slightly.

    The left-hand panels portray the area as it appeared to MISR's vertical-viewing (nadir) camera, and are false-color views comprised of data from the near-infrared, green and blue channels. Here, wet and/or moist surfaces appear blue-green, since water selectively absorbs longer wavelengths such as near-infrared. The right-hand panels are multi-angle composites created with red band data from MISR's 60-degree forward, nadir and 60-degree backward-viewing cameras, displayed as red, green and blue, respectively. In these multi-angle composites, color variations serve as a proxy for changes in angular reflectance, and indicate textural properties of the surface related to roughness and/or moisture content.Data from the two dates were processed identically to preserve relative variations in brightness between them. Wet surfaces or areas with standing water appear green due to the effect of sunglint at the nadir camera view angle. Dry, salt encrusted parts of the lake appear bright white or gray. Purple areas have enhanced forward scattering, possibly as a result of surface moistness. Some variations exhibited by the multi-angle composites are not discernible in the nadir multi-spectral images and vice versa, suggesting that the combination of angular and spectral information is a more powerful diagnostic of surface conditions than either technique by itself.

    The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 5194 and 15679. The panels cover an area of 146 kilometers x 122 kilometers, and utilize data from blocks 113 to 114 within World Reference System-2 path 100.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  10. Moat Development and Evolution on a Perennialy Ice-Covered Lake in East Antarctica

    NASA Astrophysics Data System (ADS)

    Wayt, M. E.; Myers, K. F.; Doran, P.

    2017-12-01

    Lake Fryxell is a closed basin lake located in the lower end of Taylor Valley in McMurdo Dry Valleys of east Antarctica. The lake has an 4 m thick perennial ice-cover, however during the austral summers an ice-free moat forms around the lake margin due to increased temperatures and stream run off. Satellite imagery paired with ground-based camera data from Lake Fryxell were used to determine onset of moat formation, moat duration, and total area of open water at peak formation from 2009 through 2015. Temperature data from a meteorological station on the shore of Lake Fryxell were used to correlate degree days above freezing (DDAF) with moat formation and extent. The results showed that overall, the moat was smallest in 2009-10, accounting for roughly .61% percent of the surface area of Lake Fryxell. In 2010-11 and 2011-12 moat extent increase by roughly 1% and then decreased by 4% in 2012-13. In 2013-14 the moat was at its largest, accounting for about 11% with a decrease in area of 6% the following summer. Preliminary analysis of temperature data suggest a correlation between DDAF and moat extent. Moats make up on average 9% of lake area and are likely sites of elevated primary productivity in the summer. Moats are ice free which allows for unobstructed photosynthetically active radiation to penetrate the shallow water column. We hypothesize projected increases in air temperatures will lead to continued rise in lake level and larger moat areas, making it critical to understand these delicate and rapidly changing ecosystems.

  11. Nutrient and sediment transport in streams of the Lake Tahoe basin: a 30-year retrospective

    Treesearch

    Robert Coats

    2004-01-01

    Lake Tahoe, widely renowned for its astounding clarity and deep blue color, lies at an elevation of 1,898 meters (m) in the central Sierra Nevada, astride the California-Nevada border. The volume of the lake is 156 cubic kilometers (km3), and its surface area is 501 square kilometers (km2), 38 percent of the total basin...

  12. The regional and global significance of nitrogen removal in lakes and reservoirs

    USGS Publications Warehouse

    Harrison, J.A.; Maranger, R.J.; Alexander, Richard B.; Giblin, A.E.; Jacinthe, P.-A.; Mayorga, Emilio; Seitzinger, S.P.; Sobota, D.J.; Wollheim, W.M.

    2009-01-01

    Human activities have greatly increased the transport of biologically available nitrogen (N) through watersheds to potentially sensitive coastal ecosystems. Lentic water bodies (lakes and reservoirs) have the potential to act as important sinks for this reactive N as it is transported across the landscape because they offer ideal conditions for N burial in sediments or permanent loss via denitrification. However, the patterns and controls on lentic N removal have not been explored in great detail at large regional to global scales. In this paper we describe, evaluate, and apply a new, spatially explicit, annual-scale, global model of lentic N removal called NiRReLa (Nitrogen Retention in Reservoirs and Lakes). The NiRReLa model incorporates small lakes and reservoirs than have been included in previous global analyses, and also allows for separate treatment and analysis of reservoirs and natural lakes. Model runs for the mid-1990s indicate that lentic systems are indeed important sinks for N and are conservatively estimated to remove 19.7 Tg N year-1 from watersheds globally. Small lakes (<50 km2) were critical in the analysis, retaining almost half (9.3 Tg N year -1) of the global total. In model runs, capacity of lakes and reservoirs to remove watershed N varied substantially at the half-degree scale (0-100%) both as a function of climate and the density of lentic systems. Although reservoirs occupy just 6% of the global lentic surface area, we estimate they retain ~33% of the total N removed by lentic systems, due to a combination of higher drainage ratios (catchment surface area:lake or reservoir surface area), higher apparent settling velocities for N, and greater average N loading rates in reservoirs than in lakes. Finally, a sensitivity analysis of NiRReLa suggests that, on-average, N removal within lentic systems will respond more strongly to changes in land use and N loading than to changes in climate at the global scale. ?? 2008 Springer Science+Business Media B.V.

  13. Local and synoptic controls on rapid supraglacial lake drainage in West Greenland

    NASA Astrophysics Data System (ADS)

    Williamson, Andrew; Banwell, Alison; Arnold, Neil; Willis, Ian

    2016-04-01

    Many supraglacial lakes within the ablation zone of the Greenland Ice Sheet (GrIS) are known to drain rapidly (in <1 day) in the mid- to late melt season, delivering large meltwater pulses to the subglacial drainage system, thus affecting basal water pressures and ice-sheet dynamics. Although it is now generally recognised that rapid lake drainage is caused by hydrofracture, the precise controls on hydrofracture initiation remain poorly understood: they may be linked to a local critical water-volume threshold, or they may be associated with synoptic-scale factors, such as ice thickness, driving stresses, ice velocities and strain rates. A combination of the local water-volume threshold and one or more synoptic-scale factors may explain the overall patterns of rapid lake drainage, but this requires verification using targeted field- and remotely-based studies that cover large areas of the GrIS and span long timescales. Here, we investigate a range of potential controls on rapid supraglacial lake drainage in the land-terminating Paakitsoq region of the ice sheet, northeast of Jakobshavn Isbræ, for the 2014 melt season. We have analysed daily 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) imagery in order to calculate lake areas, depths and volumes, and have developed an automatic lake-tracking algorithm to determine the dates on which all rapid lake drainage events occur. For each rapidly draining lake, the water volumes immediately prior to drainage are compared with other local factors, notably lake-filling rate and ice thickness, and with a variety of synoptic-scale features, such as slope angles, driving stresses, surface velocities, surface strain rates and the incidence of nearby lake-drainage events. We present the outcomes of our statistical analysis to elicit the statistically significant controls on hydrofracture beneath supraglacial lakes.

  14. A comparison of interpolation methods on the basis of data obtained from a bathymetric survey of Lake Vrana, Croatia

    NASA Astrophysics Data System (ADS)

    Šiljeg, A.; Lozić, S.; Šiljeg, S.

    2015-08-01

    The bathymetric survey of Lake Vrana included a wide range of activities that were performed in several different stages, in accordance with the standards set by the International Hydrographic Organization. The survey was conducted using an integrated measuring system which consisted of three main parts: a single-beam sonar HydroStar 4300 and GPS devices; a Ashtech ProMark 500 base, and a Thales Z-Max® rover. A total of 12 851 points were gathered. In order to find continuous surfaces necessary for analysing the morphology of the bed of Lake Vrana, it was necessary to approximate values in certain areas that were not directly measured, by using an appropriate interpolation method. The main aims of this research were as follows: (a) to compare the efficiency of 14 different interpolation methods and discover the most appropriate interpolators for the development of a raster model; (b) to calculate the surface area and volume of Lake Vrana, and (c) to compare the differences in calculations between separate raster models. The best deterministic method of interpolation was multiquadric RBF (radio basis function), and the best geostatistical method was ordinary cokriging. The root mean square error in both methods measured less than 0.3 m. The quality of the interpolation methods was analysed in two phases. The first phase used only points gathered by bathymetric measurement, while the second phase also included points gathered by photogrammetric restitution. The first bathymetric map of Lake Vrana in Croatia was produced, as well as scenarios of minimum and maximum water levels. The calculation also included the percentage of flooded areas and cadastre plots in the case of a 2 m increase in the water level. The research presented new scientific and methodological data related to the bathymetric features, surface area and volume of Lake Vrana.

  15. Water and bed-sediment quality in the vicinity of Berlin Lake, Ohio, 2001

    USGS Publications Warehouse

    Darner, Robert A.

    2002-01-01

    Berlin Lake, in northeast Ohio, was created by the U.S. Army Corps of Engineers in 1943 and is used primarily for flood control for the upper reaches of the Mahoning River. The area surrounding and under the lake has been tapped for oil and natural gas production. One of the by-products of oil and gas production is concentrated salt water or brine, which might have an effect on the chemical quality of area potable-water sources. This report presents the results of a U.S. Geological Survey baseline study to collect current (2001) water and sediment-quality data and to characterize water quality in the Berlin Lake watershed. Chloride-to-bromide ratios were used to detect the presence of brine in water samples and to indicate possible adverse effects on water quality. Analyses of ground-water samples from domestic wells in the area indicate a source of chloride and bromide, but defining the source would require more data collection. Analyses of specific conductance and dissolved solids indicate that 78 percent (14 of 18) of the ground-water samples exceeded the Secondary Maximum Contaminant Level for dissolved solids in public water supplies of 500 milligrams per liter (mg/L), compared to 6 percent of samples exceeding 500 mg/L in two nearby studies. Surface water was analyzed twice, once each during low-flow and surface runoff conditions. A comparison of the 2001 data to historical chloride concentrations, accounting for seasonal changes, does not indicate an increase in chloride loads for surface water in the area of Berlin Lake. Polycyclic aromatic hydrocarbons were found in bed-sediment samples collected from the mouths of major tributaries to Berlin Lake. Polycyclic aromatic hydrocarbons are produced during the incomplete combustion of organic carbon materials such as wood and fossil fuels, and they are components of petroleum products.

  16. An approach to hydrogeological modeling of a large system of groundwater-fed lakes and wetlands in the Nebraska Sand Hills, USA

    NASA Astrophysics Data System (ADS)

    Rossman, Nathan R.; Zlotnik, Vitaly A.; Rowe, Clinton M.

    2018-05-01

    The feasibility of a hydrogeological modeling approach to simulate several thousand shallow groundwater-fed lakes and wetlands without explicitly considering their connection with groundwater is investigated at the regional scale ( 40,000 km2) through an application in the semi-arid Nebraska Sand Hills (NSH), USA. Hydraulic heads are compared to local land-surface elevations from a digital elevation model (DEM) within a geographic information system to assess locations of lakes and wetlands. The water bodies are inferred where hydraulic heads exceed, or are above a certain depth below, the land surface. Numbers of lakes and/or wetlands are determined via image cluster analysis applied to the same 30-m grid as the DEM after interpolating both simulated and estimated heads. The regional water-table map was used for groundwater model calibration, considering MODIS-based net groundwater recharge data. Resulting values of simulated total baseflow to interior streams are within 1% of observed values. Locations, areas, and numbers of simulated lakes and wetlands are compared with Landsat 2005 survey data and with areas of lakes from a 1979-1980 Landsat survey and the National Hydrography Dataset. This simplified process-based modeling approach avoids the need for field-based morphology or water-budget data from individual lakes or wetlands, or determination of lake-groundwater exchanges, yet it reproduces observed lake-wetland characteristics at regional groundwater management scales. A better understanding of the NSH hydrogeology is attained, and the approach shows promise for use in simulations of groundwater-fed lake and wetland characteristics in other large groundwater systems.

  17. Earth Observation

    NASA Image and Video Library

    2011-06-29

    ISS028-E-010162 (29 June 2011) --- Sault Ste Marie, Ontario and Michigan are featured in this image photographed by an Expedition 28 crew member on the International Space Station. The twin cities of Sault Ste Marie are located across the St. Mary?s River that forms part of the international boundary between Canada (Province of Ontario) and the United States (State of Michigan). This photograph highlights the two cities, together with the region of lakes and islands that separates Lakes Huron and Superior, two of the Great Lakes of North America. Smaller lakes include Lake George to the west; the large forested islands of St. Joseph and Drummond are visible at lower left. The Sault Ste Marie urban areas (upper right) have a distinctive gray to white coloration in the image, contrasting with the deep green of forested areas in Ontario and the lighter green of agricultural fields in Michigan. The coloration of water surfaces in the lakes and rivers varies from blue to blue-green to silver, and is likely caused by varying degrees of sediment and sunglint ? light reflecting back to the observer on the space station from the water surface, much as light reflects from a mirror. Prior to formalization of the US/Canada border in 1817, Sault Ste Marie was a single community. Archeological evidence suggests that the region had been occupied by Native Americans at least five hundred years ago. A mission ? the first European settlement in Michigan ? was established there in 1668 by the French Jesuit Father Jacques Marquette. Today, shipping locks and canals in both urban areas are an important part of the Great Lakes shipping traffic system.

  18. Hydrologic Data for Deep Creek Lake and Selected Tributaries, Garrett County, Maryland, 2007-08

    USGS Publications Warehouse

    Banks, William S.L.; Davies, William J.; Gellis, Allen C.; LaMotte, Andrew E.; McPherson, Wendy S.; Soeder, Daniel J.

    2010-01-01

    Introduction Recent and ongoing efforts to develop the land in the area around Deep Creek Lake, Garrett County, Maryland, are expected to change the volume of sediment moving toward and into the lake, as well as impact the water quality of the lake and its many tributaries. With increased development, there is an associated increased demand for groundwater and surface-water withdrawals, as well as boat access. Proposed dredging of the lake bottom to improve boat access has raised concerns about the adverse environmental effects such activities would have on the lake. The Maryland Department of Natural Resources (MDDNR) and the U.S. Geological Survey (USGS) entered into a cooperative study during 2007 and 2008 to address these issues. This study was designed to address several objectives to support MDDNR?s management strategy for Deep Creek Lake. The objectives of this study were to: Determine the current physical shape of the lake through bathymetric surveys; Initiate flow and sediment monitoring of selected tributaries to characterize the stream discharge and sediment load of lake inflows; Determine sedimentation rates using isotope analysis of sediment cores; Characterize the degree of hydraulic connection between the lake and adjacent aquifer systems; and Develop an estimate of water use around Deep Creek Lake. Summary of Activities Data were collected in Deep Creek Lake and in selected tributaries from September 2007 through September 2008. The methods of investigation are presented here and all data have been archived according to USGS policy for future use. The material presented in this report is intended to provide resource managers and policy makers with a broad understanding of the bathymetry, surface water, sedimentation rates, groundwater, and water use in the study area. The report is structured so that the reader can access each topic separately using any hypertext markup (HTML) language reader. In order to establish a base-line water-depth map of Deep Creek Lake, a bathymetric survey of the lake bottom was conducted in 2007. The data collected were used to generate a bathymetric map depicting depth to the lake bottom from a full pool elevation of 2,462 feet (National Geodetic Vertical Datum of 1929). Data were collected along about 90 linear miles across the lake using a fathometer and a differentially corrected global positioning system. As part of a long-term monitoring plan for all surface-water inputs to the lake, streamflow data were collected continuously at two stations constructed on Poland Run and Cherry Creek. The sites were selected to represent areas of the watershed under active development and areas that are relatively stable with respect to development. Twelve months of discharge data are provided for both streams. In addition, five water-quality parameters were collected continuously at the Poland Run station including pH, specific conductance, temperature, dissolved oxygen, and turbidity. Water samples collected at Poland Run were analyzed for sediment concentration, and the results of this analysis were used to estimate the annual sediment load into Deep Creek Lake from Poland Run. To determine sedimentation rates, cores of lake-bottom sediments were collected at 23 locations. Five of the cores were analyzed using a radiometric-dating method, allowing average rates of sedimentation to be estimated for the time periods 1925 to 2008, 1925 to 1963, and 1963 to 2008. Particle-size data from seven cores collected at locations throughout the study area were analyzed to provide information on the amount of fine material in lake-bed sediments. Groundwater levels were monitored continuously in four wells and weekly in nine additional wells during October, November, and December of 2008. Water levels were compared to recorded lake levels and precipitation during the same period to determine the effect of lake-level drawdown and recovery on the adjacent aquifer systems. Water use in the Deep Creek Lake wa

  19. A review of water resources of the Umiat area, northern Alaska

    USGS Publications Warehouse

    Williams, John R.

    1970-01-01

    Surface-water supplies from the Colville River, small tributary creeks, and lakes are abundant in summer but limited in winter by low or zero flow in streams and thick ice cover on lakes. Fresh ground water occurs in unfrozen zones in alluvium and in the upper part of bedrock beneath the Colville River and beneath lakes that do not freeze to the bottom in winter. These unfrozen zones, forming depressions in the upper surface of permafrost, are maintained by flow of heat from bodies of surface water into subjacent alluvium and bedrock. Brackish or saline ground water occurs in bedrock beneath as much as 1,055 feet of permafrost in the Arctic foothills and beneath 750 to 800 feet of permafrost beneath low terraces of the Colville River valley. The foothill area is unfavorable for developing supplies of potable ground water because of the great depth to water, predominance of brackish or saline water, and low potential yield of the bedrock. In the Colville River valley, shallow unfrozen alluvium beneath the river and deep lakes will yield abundant year-round supplies of ground water, but the bedrock below permafrost yields less than 10 gpm (gallons per minute) of saline or brackish water.

  20. Emerald Lake Watershed study: Introduction and site description

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tonnessen, K.A.

    1991-07-01

    The Emerald Lake Watershed study was organized to investigate the effects of acidic deposition on high-elevation watersheds and surface waters of the Sierra Nevada, California. Some of the results of this comprehensive study of aquatic and terrestrial ecosystems at a small, headwater basin are presented in four papers in this series. The watershed study site is in Sequoia National Park, on the western slope of the Sierra Nevada. This glacial cirque is located in the upper Marble Fork of the Kaweah River. This 120-ha watershed ranges from Alta Peak (3,416 m) down to Emerald Lake (2,400 m). Most of themore » watershed surface area is exposed granite and granodiorite rocks, with limited coverage (about 20%) by thin, acidic soils. The hydrology of the basin is dominated by snowmelt runoff during March-June. Emerald Lake, a glacial tarn, is 2.72 ha in area, with a maximum depth of 10.5 m. Surface waters are poorly buffered and dominated by calcium and bicarbonate. Most of the yearly precipitation falls as dilute snow (pH5.2-5.4), with acidic rain storms sampled during May-October.« less

  1. Hydrocarbon lakes on Titan

    NASA Astrophysics Data System (ADS)

    Mitri, Giuseppe; Showman, Adam P.; Lunine, Jonathan I.; Lorenz, Ralph D.

    2007-02-01

    The Huygens Probe detected dendritic drainage-like features, methane clouds and a high surface relative humidity (∼50% ) on Titan in the vicinity of its landing site [Tomasko, M.G., and 39 colleagues, 2005. Nature 438, 765-778; Niemann, H.B., and 17 colleagues, 2005. Nature 438, 779-784], suggesting sources of methane that replenish this gas against photo- and charged-particle chemical loss on short (10-100) million year timescales [Atreya, S.K., Adams, E.Y., Niemann, H.B., Demick-Montelara, J.E., Owen, T.C., Fulchignoni, M., Ferri, F., Wilson, E.H., 2006. Planet. Space Sci. In press]. On the other hand, Cassini Orbiter remote sensing shows dry and even desert-like landscapes with dunes [Lorenz, R.D., and 39 colleagues, 2006a. Science 312, 724-727], some areas worked by fluvial erosion, but no large-scale bodies of liquid [Elachi, C., and 34 colleagues, 2005. Science 308, 970-974]. Either the atmospheric methane relative humidity is declining in a steady fashion over time, or the sources that maintain the relative humidity are geographically restricted, small, or hidden within the crust itself. In this paper we explore the hypothesis that the present-day methane relative humidity is maintained entirely by lakes that cover a small part of the surface area of Titan. We calculate the required minimum surface area coverage of such lakes, assess the stabilizing influence of ethane, and the implications for moist convection in the atmosphere. We show that, under Titan's surface conditions, methane evaporates rapidly enough that shorelines of any existing lakes could potentially migrate by several hundred m to tens of km per year, rates that could be detected by the Cassini orbiter. We furthermore show that the high relative humidity of methane in Titan's lower atmosphere could be maintained by evaporation from lakes covering only 0.002-0.02 of the whole surface.

  2. The geometry of folds in granitoid rocks of northeastern Alberta

    NASA Astrophysics Data System (ADS)

    Willem Langenberg, C.; Ramsden, John

    1980-06-01

    Granitoid rocks which predominate in the Precambrian shield of northeastern Alberta show large-scale fold structures. A numerical procedure has been used to obtain modal foliation orientations. This procedure results in the smoothing of folded surfaces that show roughness on a detailed scale. Statistical tests are used to divide the study areas into cylindrical domains. Structural sections can be obtained for each domain, and horizontal and vertical sections are used to construct block diagrams. The projections are performed numerically and plotted by computer. This method permits blocks to be viewed from every possible angle. Both perspective and orthographic projections can be produced. The geometries of a dome in the Tulip Lake area and a synform in the Hooker Lake area have been obtained. The domal structure is compared with polyphase deformational interference patterns and with experimental diapiric structures obtained in a centrifuge system. The synform in the Hooker Lake area may be genetically related to the doming in the Tulip Lake area.

  3. Coastal wetlands of Lake Superior’s south shore

    EPA Science Inventory

    There are more than two thousand coastal wetlands that encompass an area of about 215,000 ha in the Laurentian Great Lakes (LGL) of North America. Coastal wetlands in the LGL are distinguished hydrologically from nearby inland wetlands by a direct surface water connection with wa...

  4. Hydrogeological features conditioning trophic levels of quarry lakes in western Po plain (north-western Italy)

    NASA Astrophysics Data System (ADS)

    De Luca, Domenico Antonio; Castagna, Sara; Lasagna, Manuela

    2013-04-01

    Quarry lakes occur in plains areas due to the extraction of alluvial sand and gravel used for grout and concrete in the construction industry. Excavation depths can reach and intersect the groundwater surface, thus creating a lake. Because of the need to optimize efficiency, the number of active open pit mines has increased in recent years; consequently, the global number of pit lakes will increase in coming decades (Castendyk and Eary 2009; Klapper and Geller 2001; Castro and Moore 2000). Similar to natural lakes, pit lakes are subject to eutrophication process, both during and after quarrying activity; during mining activity, the eutrophic level is strongly controlled by the excavation method. In the Piedmont territory (north-western Italy) there are 70 active quarry lakes, corresponding to approximately 0.1% of the entire plain area. Quarry lakes, located primarily along the main rivers occur in alluvial deposits of the plain area and have average depths between 20 and 30 m (maximum of 60 m deep) and surface areas between 3 and 30 hectares (Castagna 2008). The present study describes the trophic status of 23 active quarry lakes in the Piedmont plain that were evaluated by applying classifications from scientific literature. Currently, the majority of the studied quarry lakes may be defined as mesotrophic or eutrophic according to the trophic state classifications. Based on historic data, lake trophic levels have increased over time, during active mining. At the end of mining activity, further deterioration of water quality was expected, especially for smaller lakes with minimal oxygen stratification and higher levels of nutrients and algal growth. In addition, the paper focuses on the pit lake water quality and pit dimension; From an environmental perspective the excavation of quarry lakes with an appreciable size will likely result in a better safeguard of water quality and enhanced possibilities for lake end use after the cessation of mining. Piedmont quarry lakes, for the most part, have rather large depths (over 20 m), and moreover, unlike natural lakes, this type of lake is not influenced by sewage inputs that are often a primary cause of eutrophication in natural lakes. It was shown that, in Piedmont, lakes with a larger depth and volume generally had a lower tendency towards eutrophication. References Castendyk D, Eary T (2009). The nature and global distribution of pit lakes. In, Mine Pit Lakes: Characteristics, Predictive Modeling, and Sustainability Castendyk, D.; Eary, T. and Park, B. (eds.) Society for Mining Engineering (SME), Colorado, USA, 1-11pp. Klapper H, Geller W (2001) Water quality management of mining lakes - a new field of applied hydrobiology. Acta Hydrochim Hydrobiol, 29: 363-374 Castro JM, Moore JN (2000) Pit lakes: their characteristics and the potential for their remediation. Environ Geol, 39(11):1254-1260 Castagna S (2008) Studio delle problematiche idrogeologiche nelle attività estrattive sottofalda per materiali granulari. Ph.D. Thesis.

  5. Influence of Lake Malawi on regional climate from a double-nested regional climate model experiment

    NASA Astrophysics Data System (ADS)

    Diallo, Ismaïla; Giorgi, Filippo; Stordal, Frode

    2017-07-01

    We evaluate the performance of the regional climate model (RCM) RegCM4 coupled to a one dimensional lake model for Lake Malawi (also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique) in simulating the main characteristics of rainfall and near surface air temperature patterns over the region. We further investigate the impact of the lake on the simulated regional climate. Two RCM simulations, one with and one without Lake Malawi, are performed for the period 1992-2008 at a grid spacing of 10 km by nesting the model within a corresponding 25 km resolution run ("mother domain") encompassing all Southern Africa. The performance of the model in simulating the mean seasonal patterns of near surface air temperature and precipitation is good compared with previous applications of this model. The temperature biases are generally less than 2.5 °C, while the seasonal cycle of precipitation over the region matches observations well. Moreover, the one-dimensional lake model reproduces fairly well the geographical pattern of observed (from satellite measurements) lake surface temperature as well as its mean month-to-month evolution. The Malawi Lake-effects on the moisture and atmospheric circulation of the surrounding region result in an increase of water vapor mixing ratio due to increased evaporation in the presence of the lake, which combines with enhanced rising motions and low-level moisture convergence to yield a significant precipitation increase over the lake and neighboring areas during the whole austral summer rainy season.

  6. Bathymetric Contour Maps for Lakes Surveyed in Iowa in 2006

    USGS Publications Warehouse

    Linhart, S.M.; Lund, K.D.

    2008-01-01

    The U.S. Geological Survey, in cooperation with the Iowa Department of Natural Resources, conducted bathymetric surveys on two lakes in Iowa during 2006 (Little Storm Lake and Silver Lake). The surveys were conducted to provide the Iowa Department of Natural Resources with information for the development of total maximum daily load limits, particularly for estimating sediment load and deposition rates. The bathymetric surveys can provide a baseline for future work on sediment loads and deposition rates for these lakes. Both of the lakes surveyed in 2006 are natural lakes. For Silver Lake, bathymetric data were collected using boat-mounted, differential global positioning system, echo depth-sounding equipment, and computer software. For Little Storm Lake, because of its shallow nature, bathymetric data were collected using manual depth measurements. Data were processed with commercial hydrographic software and exported into a geographic information system for mapping and calculating area and volume. Lake volumes were estimated to be 7,547,000 cubic feet (173 acre-feet) at Little Storm Lake and 126,724,000 cubic feet (2,910 acre-feet) at Silver Lake. Surface areas were estimated to be 4,110,000 square feet (94 acres) at Little Storm Lake and 27,957,000 square feet (640 acres) at Silver Lake.

  7. Hydrology of the Reelfoot Lake basin, Obion and Lake counties, northwestern Tennessee

    USGS Publications Warehouse

    Robbins, C.H.

    1985-01-01

    Nine maps describe the following water resources aspects of the Reelfoot Lake watershed: Map 1-Surface water gaging stations, lake level, and locations of observation wells, rainfall stations and National Weather Service rainfall stations; Maps 2 and 3-water level contours, river stage, groundwater movement; Maps 4 and 5-grid blocks simulating constant head on the Mississippi River, Reelfoot Lake, Running Reelfoot Bayou, Reelfoot Creek, and Running Slough; Maps 6 and 7-difference between model calculated and observed water levels; and Maps 8 and 9-line of equal groundwater level increase and approximate lake area at pool elevation. (Lantz-PTT)

  8. Occurrence, distribution, and risk assessment of antibiotics in the surface water of Poyang Lake, the largest freshwater lake in China.

    PubMed

    Ding, Huijun; Wu, Yixiao; Zhang, Weihao; Zhong, Jiayou; Lou, Qian; Yang, Ping; Fang, Yuanyuan

    2017-10-01

    SPE-UPLC-MS/MS was used to investigate the occurrence of 18 target antibiotics in the surface water of Poyang Lake over different seasons of 2014-2015. The maximum concentrations of sulfadiazine, oxytetracycline, and doxycycline were 56.2, 48.7, and 39.7 ng/L, respectively. Compared with those in the other lakes or surface waters, the surface water of Poyang Lake contained moderate or below-average levels of antibiotics. The significantly lower concentrations (P < 0.01) of roxithromycin in June 2015 likely resulted from the dilution effect of water flow during the flood season. Antibiotic concentrations were higher in site P3-1 than in other sites (P < 0.01), whereas those in other sites (P1-1, P2-1, P5-1, P6-1, P7-1, P13-1, P16-1, P17-1, P18-1) were not significantly different (P > 0.05). Given that tetracyclines and sulfonamides are common veterinary medicines, the high concentrations of oxytetracycline, doxycycline, and sulfadiazine in site P3-1 might be closely related to agricultural production in the surrounding areas. The risk assessment of the main antibiotic contaminants revealed that the majority of the risk quotients of the target antibiotics were below 0.01, thereby indicating the minimal risk of these antibiotics to organisms at three different trophic levels. Sulfadimidine and sulfadiazine were identified as the main antibiotics that contribute to ecological risk in Poyang Lake, and that the daphnid is the main model organism exposed to these risks. This study provides important data for antibiotic pollution control and environmental protection in the study area and enriches environmental monitoring data on a global scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. National Surface Water Survey, western wilderness area lakes: environmental assessment. Draft

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1985-03-01

    The US Environmental Protection Agency (EPA) is proposing to sample 498 lakes in federally designated wilderness areas and national parks during the western part of the National Surface Water Survey (NSW). The NSWS has been undertaken to provide high quality data for evaluating the nature and extent of acid deposition throughout the United States. Sampling protocols established for the national survey call for the use of helicopters to gain access to lakes for sampling. Helicopters have already been used in the eastern and midwestern parts of the survey. The US Forest Service (FS) and the National Park Service (NPS) willmore » have to decide which sampling plan for wilderness areas, if any, can be approved under the Wilderness Act of 1964. This Environmental Assessment (EA) has been prepared to evaluate the environmental consequences of alternative means of gaining access to wilderness areas to meet the objectives of the NSWS. Based on this evaluation, EPA has reviewed the possible sampling alternatives and reached a conclusion on the preferred alternative. This assessment is being provided to the FS and the NPS for their use in evaluating the alternatives, including EPA's preferred one. As a result of its evaluation, EPA believes that wilderness area lakes should be included in the survey and that the preferred means of access is using helicopters. 94 references, 14 figures, 18 tables.« less

  10. Three frequency false-color image of Oberpfaffenhofen supersite in Germany

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a three-frequency, false color image of the Oberpfaffenhofen supersite, an area just south-west of Munich in southern Germany. This image was acquired by the Spaceborne Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the Shuttle Endeavour, April 11, 1994. The image is centered at 48.09 degrees north, 11.29 degrees east. The dark area on the left is Lake Ammersee. The two smaller lakes are the Woerthsee and the Pilsensee. On the bottom is the tip of the Starnbergersee. The city of Munich is located just beyond the right of the image. The forested areas have a reddish tint (L-Band). THe green areas seen near both the Ammersee and the Pilsensee lakes indicate marshy areas. The agricultural fields in the upper right hand corner appear mostly in blue and green (X-band and C-band). The white areas are mostly urban areas, while the smooth surfaces of the lakes appear very dark. The Jet Propulsion Laboratory alternative photo number is P-43930.

  11. Documentation of a computer program to simulate lake-aquifer interaction using the MODFLOW ground water flow model and the MOC3D solute-transport model

    USGS Publications Warehouse

    Merritt, Michael L.; Konikow, Leonard F.

    2000-01-01

    Heads and flow patterns in surficial aquifers can be strongly influenced by the presence of stationary surface-water bodies (lakes) that are in direct contact, vertically and laterally, with the aquifer. Conversely, lake stages can be significantly affected by the volume of water that seeps through the lakebed that separates the lake from the aquifer. For these reasons, a set of computer subroutines called the Lake Package (LAK3) was developed to represent lake/aquifer interaction in numerical simulations using the U.S. Geological Survey three-dimensional, finite-difference, modular ground-water flow model MODFLOW and the U.S. Geological Survey three-dimensional method-of-characteristics solute-transport model MOC3D. In the Lake Package described in this report, a lake is represented as a volume of space within the model grid which consists of inactive cells extending downward from the upper surface of the grid. Active model grid cells bordering this space, representing the adjacent aquifer, exchange water with the lake at a rate determined by the relative heads and by conductances that are based on grid cell dimensions, hydraulic conductivities of the aquifer material, and user-specified leakance distributions that represent the resistance to flow through the material of the lakebed. Parts of the lake may become ?dry? as upper layers of the model are dewatered, with a concomitant reduction in lake surface area, and may subsequently rewet when aquifer heads rise. An empirical approximation has been encoded to simulate the rewetting of a lake that becomes completely dry. The variations of lake stages are determined by independent water budgets computed for each lake in the model grid. This lake budget process makes the package a simulator of the response of lake stage to hydraulic stresses applied to the aquifer. Implementation of a lake water budget requires input of parameters including those representing the rate of lake atmospheric recharge and evaporation, overland runoff, and the rate of any direct withdrawal from, or augmentation of, the lake volume. The lake/aquifer interaction may be simulated in both transient and steady-state flow conditions, and the user may specify that lake stages be computed explicitly, semi-implicitly, or fully-implicitly in transient simulations. The lakes, and all sources of water entering the lakes, may have solute concentrations associated with them for use in solute-transport simulations using MOC3D. The Stream Package of MODFLOW-2000 and MOC3D represents stream connections to lakes, either as inflows or outflows. Because lakes with irregular bathymetry can exist as separate pools of water at lower stages, that coalesce to become a single body of water at higher stages, logic was added to the Lake Package to allow the representation of this process as a user option. If this option is selected, a system of linked pools (sublakes) is identified in each time step and stages are equalized based on current relative sublake surface areas.

  12. Google Earth Engine derived areal extents to infer elevation variation of lakes and reservoirs

    NASA Astrophysics Data System (ADS)

    Nguy-Robertson, Anthony; May, Jack; Dartevelle, Sebastien; Griffin, Sean; Miller, Justin; Tetrault, Robert; Birkett, Charon; Lucero, Eileen; Russo, Tess; Zentner, Matthew

    2017-04-01

    Monitoring water supplies is important for identifying potential national security issues before they begin. As a means to estimate lake and reservoir storage for sites without reliable water stage data, this study defines correlations between water body levels from hypsometry curves based on in situ gauge station and altimeter data (i.e. TOPEX/Poseidon, Jason series) and sensor areal extents observed in historic multispectral (i.e. MODIS and Landsat TM/ETM+/OLI) imagery. Water levels measured using in situ observations and altimeters, when in situ data were unavailable, were used to estimate the relationship between water elevation and surface area for 18 sites globally. Altimeters were generally more accurate (RMSE: 0.40 - 0.49 m) for estimating in situ lake elevations from Iraq and Afghanistan than the modeled elevation data using multispectral sensor areal extents: Landsat (RMSE: 0.25 - 1.5 m) and MODIS (RMSE 0.53 - 3.0 m). Correlations between altimeter data and Landsat imagery processed with Google Earth Engine confirmed similar relationships exists for a broader range of lakes without reported in situ data across the globe (RMSE: 0.24 - 1.6 m). Thus, while altimetry is still preferred to an areal extent model, lake surface area derived with Google Earth Engine can be used as a reasonable proxy for lake storage, expanding the number of observable lakes beyond the current constellation of altimeters and in situ gauges.

  13. Mechanisms Controlling Variability of Lake Salinity in Dune Environments in a Semi-arid Climate: The Nebraska Sand Hills (Invited)

    NASA Astrophysics Data System (ADS)

    Zlotnik, V. A.; Ong, J. T.; Swinehart, J. B.; Fritz, S. C.; Lenters, J. D.; Schmieder, J. U.; Lane, J. W.; Halihan, T.

    2010-12-01

    Shallow endorheic saline lakes are common in semi-arid environments in North America, Africa, Asia, and Australia. These lakes receive minimal surface runoff and are supported by groundwater seepage. A combination of hydrologic and geologic factors (regional groundwater flow, evaporation, precipitation, lake size, groundwater recharge, and geologic setting) may preclude seepage out of these lakes, even in the presence of ambient regional flow. Solutes from groundwater are captured by these lakes and become enriched over time by evaporation. The importance of understanding lake dynamics in these arid and semi-arid systems is increasing with societal concerns, including water availability and quality, the use of aquatic ecosystems by waterfowl and other biota, and dangers of dust emissions associated with lake desiccation. We consider the salinity of shallow lakes as a useful indicator of hydroclimatic factors operating at centennial and millennial scales. The Nebraska Sand Hills cover 58 000 km2 of the central Great Plains and are the largest dunefield in the Western Hemisphere. The grass-stabilized dunes attain heights up to 130 m and have been modified by soil development and erosion. In an area <7000 km2, there are ~400 lakes with surface areas >4 ha and depths <1 m. Annual lake evaporation exceeds precipitation by 600 mm, according to some estimates. The salinity of natural lakes in the Nebraska Sand Hills ranges from fresh (~0.3 g L-1) to hypersaline (>100 g L-1), with pH values as high as ~10. We assess the mechanisms that control lake salinity in a group of lakes with different subsurface flow regimes. Our methods combine aquifer coring, electromagnetic and electrical resistivity tomography geophysics, hydraulic testing, lakebed dating using 14C and optically stimulated luminescence, energy and water balance analysis, and salt crust and dust collection. Our theory and results show that terrain and water-table topography, lithology, and climate control the lake-aquifer solute exchanges. This study also brings attention to an underappreciated mechanism in the area, namely eolian deflation, which has not been quantified previously. An interaction of hydraulic and eolian mechanisms controls lake salinity, which may strongly depend on the sequence of arid and pluvial episodes.

  14. Consequences of gas flux model choice on the interpretation of metabolic balance across 15 lakes

    USGS Publications Warehouse

    Dugan, Hilary; Woolway, R. Iestyn; Santoso, Arianto; Corman, Jessica; Jaimes, Aline; Nodine, Emily; Patil, Vijay; Zwart, Jacob A.; Brentrup, Jennifer A.; Hetherington, Amy; Oliver, Samantha K.; Read, Jordan S.; Winters, Kirsten; Hanson, Paul; Read, Emily; Winslow, Luke; Weathers, Kathleen

    2016-01-01

    Ecosystem metabolism and the contribution of carbon dioxide from lakes to the atmosphere can be estimated from free-water gas measurements through the use of mass balance models, which rely on a gas transfer coefficient (k) to model gas exchange with the atmosphere. Theoretical and empirically based models of krange in complexity from wind-driven power functions to complex surface renewal models; however, model choice is rarely considered in most studies of lake metabolism. This study used high-frequency data from 15 lakes provided by the Global Lake Ecological Observatory Network (GLEON) to study how model choice of kinfluenced estimates of lake metabolism and gas exchange with the atmosphere. We tested 6 models of k on lakes chosen to span broad gradients in surface area and trophic states; a metabolism model was then fit to all 6 outputs of k data. We found that hourly values for k were substantially different between models and, at an annual scale, resulted in significantly different estimates of lake metabolism and gas exchange with the atmosphere.

  15. Comparison of three methods for long-term monitoring of boreal lake area using Landsat TM and ETM+ imagery

    USGS Publications Warehouse

    Roach, Jennifer K.; Griffith, Brad; Verbyla, David

    2012-01-01

    Programs to monitor lake area change are becoming increasingly important in high latitude regions, and their development often requires evaluating tradeoffs among different approaches in terms of accuracy of measurement, consistency across multiple users over long time periods, and efficiency. We compared three supervised methods for lake classification from Landsat imagery (density slicing, classification trees, and feature extraction). The accuracy of lake area and number estimates was evaluated relative to high-resolution aerial photography acquired within two days of satellite overpasses. The shortwave infrared band 5 was better at separating surface water from nonwater when used alone than when combined with other spectral bands. The simplest of the three methods, density slicing, performed best overall. The classification tree method resulted in the most omission errors (approx. 2x), feature extraction resulted in the most commission errors (approx. 4x), and density slicing had the least directional bias (approx. half of the lakes with overestimated area and half of the lakes with underestimated area). Feature extraction was the least consistent across training sets (i.e., large standard error among different training sets). Density slicing was the best of the three at classifying small lakes as evidenced by its lower optimal minimum lake size criterion of 5850 m2 compared with the other methods (8550 m2). Contrary to conventional wisdom, the use of additional spectral bands and a more sophisticated method not only required additional processing effort but also had a cost in terms of the accuracy and consistency of lake classifications.

  16. Construction, geologic, and hydrologic data for observation wells in the Reelfoot Lake area, Tennessee and Kentucky

    USGS Publications Warehouse

    Bradley, M.W.

    1987-01-01

    Twenty-three observation wells were installed at 12 sites in the Reelfoot Lake area of Kentucky and Tennessee during July 1986. The wells were installed to supplement an existing water level network and to provide additional data on the hydraulic characteristics and vertical hydraulic gradients in the alluvial aquifer near Reelfoot Lake. Well yields ranged from less than 20 gallons per minute to about 140 gallons per minute. The specific capacities of the wells ranged from less than 1 to 17.1 gallons per minute per foot of drawdown. Dissolved-solids concentrations ranged from 153 to 475 milligrams per liter at six wells. Three lithological sequences were encountered during drilling. Deep clay and silty clay occurred near the southwest corner of Reelfoot Lake. Predominantly medium- to coarse-grained sand occurred below about 15 feet of silt and clay near the west and northwest sides of the Lake. Along the western limit of the study area, near Lake No. 9 and the Mississippi River, at least about 50 feet of silt and silty sand occurred below land surface. (USGS)

  17. Lakes-paleolakes cascade system and its role in shaping the runoff and chemical properties of water in the young-glacial catchment - example from the Tuchola Pinewood Forest (Northern Poland)

    NASA Astrophysics Data System (ADS)

    Gierszewski, Piotr; Brykała, Dariusz; Kaszubski, Michał; Plessen, Birgit

    2016-04-01

    The impact of paleolake basins, filled up with organic mineral deposits, in the transformation of the chemical properties of the outflow is generally ignored. Defining their role and importance in the water and matter cycles is one of the objectives of the hydrological and hydrochemical monitoring, which has been run in the catchment of Lake Czechowskie since mid-2012. The axis of the Lake Czechowskie catchment is a hydrographical system made of river and lake sections. Lake sections are not only present-day lakes (Głęboczek and Czechowskie), but also basins of the lakes functioned in the past, which are now biogenic plains. Lake sections of the system are connected by short valley sections, mostly of a gap character. The size and variability of surface water runoff from the basin is mainly affected by groundwater and the size of evaporation. Stable groundwater table provides stability of the river discharge, even during the periods of significant precipitation deficit. Groundwater fluctuation ranges registered during the period from May 2012 to September 2015 were between 0.17 and 1.25 m. The smallest were in the deepest piezometers located in watershed areas, and the largest in the shallow groundwater of lake terraces. The small dynamics of the groundwater states is reflected by slight fluctuations of water levels in Lake Czechowskie, which in the analyzed period amounted 0.40 cm. The surface of paleolake Trzechowskie, cut by a system of drainage ditches, is the area where an essential part of the surface runoff from the monitored catchment is formed. Large water resources in this part of the catchment are evidenced by the specific runoff value, which amounts to 25 dm3s-1km2. It is much larger than the whole basin specific runoff which reaches 11 dm3s-1km2. The measurements showed that the average surface runoff from Lake Czechowskie in the analyzed period was 0,065 m3s-1 and was similar to the size of the water influx via watercourses supplying the lake. On the basis of this value it was calculated that the theoretical time to replace the water in Lake Czechowskie is 2.8 years. The hydrochemical study showed that the studied ground- and surface waters represent the same bicarbonate-calcium-sulphate hydrochemical type. Against the background of a homogeneous ionic composition, the spatial variation of their overall salinity is very large. This is reflected by the values of electrolytic conductivity, which in the study period ranged from 76 to 1218 μSṡcm-1. The most mineralized (700-800 μSṡcm-1) are the waters of streams migrating in the organic-carbonate formations of the paleolakes and shallow groundwater in these areas. The lowest mineralization is showed by the groundwater circulating in sandy sediments of outwash plains. Mineralization of the Lake Czechowskie water of approx. 340 μSṡcm-1 is a result of supplying the lake from both sources and the effect of biogeochemical processes occurring in the lake. The hydrochemical monitoring results showed that the zones of water enrichment in salts are associated with paleolake basins filled with the organic-carbonate sediment, while the salt precipitation zones with lakes. The results of the study of matter flow in the basin of Lake Czechowskie showed that paleolakes equally affect the runoff volume and the transformation of the chemical properties of the water circulating in the basin as the lakes functioning today. The lakes and paleolakes create a cascade system of interconnected basins. Depending on the place they occupy in the cascade, their effect on the water circulation and transformation of matter is different. This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analyses - ICLEA- of the Helmholtz Association, Grant No VH-VI-415.

  18. Insights into Near-Surface Structural Control of Hydrothermal Fluid Movement at Rabbit Creek Thermal Area, Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Carr, B.; Elliot, M.; Sims, K. W. W.

    2017-12-01

    Recent geophysical imaging efforts at Yellowstone National Park have generated questions about the geologic controls of hydrothermal fluid movement within the parks thermal areas. Currently, faults and lava flow contacts are assumed to be the primary permeability pathways for deeper fluid migration to the surface. Although intuition dictates that these structures are responsible, few studies have definitively shown that this is true. Earlier geophysical imaging efforts of phase separation in Norris Geyser Basin have shown strong evidence for fractures and faulting conducting hydrothermal waters. However, no geologically mapped faults are at the surface to confirm these interpretations. Therefore, during the summer of 2017, UW surface geophysical data acquisition focused on understanding the geologic controls for a thermal area within the well-mapped Rabbit Creek Fault Zone (RCFZ). The RCFZ strikes N-S along the eastern edge of Midway Geyser Basin (i.e. the western edge of the Mallard Lake Dome) about 2.8 Km SE of Grand Prismatic spring. The section of the fault zone within the Rabbit Creek thermal area is exposed on the eastern valley wall and dips steeply to the west. Regardless at our site, this puts the two of the plateau rhyolites (i.e. the Biscuit Basin Flow and Mallard Lake flow) next to each other ( 100 m apart) with a small amount of overlying alluvial, glacial and hydrothermal deposits covering the actual fault trace. Interestingly, at least two mapped reverse faults from the Mallard Lake Dome trend NW-SE into the site and are interpreted to intersect to the RCFZ. At RCFZ, DC resistivity and seismic refraction profiling combined with Self-Potential, Magnetics, and Transient Electromagnetic soundings were acquired to provide images and in situ geophysical properties. These data highlight the variable fracturing and surface expressions of the hydrothermal fluids associated with the RCFZ and the NW trending fault zone associated with the Mallard Lake Dome. Therefore, the shallow geophysics at this one study area indicates faulting is the dominant control for hydrothermal waters reaching the surface.

  19. Development of Turbulent Diffusion Transfer Algorithms to Estimate Lake Tahoe Water Budget

    NASA Astrophysics Data System (ADS)

    Sahoo, G. B.; Schladow, S. G.; Reuter, J. E.

    2012-12-01

    The evaporative loss is a dominant component in the Lake Tahoe hydrologic budget because watershed area (813km2) is very small compared to the lake surface area (501 km2). The 5.5 m high dam built at the lake's only outlet, the Truckee River at Tahoe City can increase the lake's capacity by approximately 0.9185 km3. The lake serves as a flood protection for downstream areas and source of water supply for downstream cities, irrigation, hydropower, and instream environmental requirements. When the lake water level falls below the natural rim, cessation of flows from the lake cause problems for water supply, irrigation, and fishing. Therefore, it is important to develop algorithms to correctly estimate the lake hydrologic budget. We developed a turbulent diffusion transfer model and coupled to the dynamic lake model (DLM-WQ). We generated the stream flows and pollutants loadings of the streams using the US Environmental Protection Agency (USEPA) supported watershed model, Loading Simulation Program in C++ (LSPC). The bulk transfer coefficients were calibrated using correlation coefficient (R2) as the objective function. Sensitivity analysis was conducted for the meteorological inputs and model parameters. The DLM-WQ estimated lake water level and water temperatures were in agreement to those of measured records with R2 equal to 0.96 and 0.99, respectively for the period 1994 to 2008. The estimated average evaporation from the lake, stream inflow, precipitation over the lake, groundwater fluxes, and outflow from the lake during 1994 to 2008 were found to be 32.0%, 25.0%, 19.0%, 0.3%, and 11.7%, respectively.

  20. Arctic lake physical processes and regimes with implications for winter water availability and management in the National Petroleum Reserve Alaska.

    PubMed

    Jones, Benjamin M; Arp, Christopher D; Hinkel, Kenneth M; Beck, Richard A; Schmutz, Joel A; Winston, Barry

    2009-06-01

    Lakes are dominant landforms in the National Petroleum Reserve Alaska (NPRA) as well as important social and ecological resources. Of recent importance is the management of these freshwater ecosystems because lakes deeper than maximum ice thickness provide an important and often sole source of liquid water for aquatic biota, villages, and industry during winter. To better understand seasonal and annual hydrodynamics in the context of lake morphometry, we analyzed lakes in two adjacent areas where winter water use is expected to increase in the near future because of industrial expansion. Landsat Thematic Mapper and Enhanced Thematic Mapper Plus imagery acquired between 1985 and 2007 were analyzed and compared with climate data to understand interannual variability. Measured changes in lake area extent varied by 0.6% and were significantly correlated to total precipitation in the preceding 12 months (p < 0.05). Using this relation, the modeled lake area extent from 1985 to 2007 showed no long-term trends. In addition, high-resolution aerial photography, bathymetric surveys, water-level monitoring, and lake-ice thickness measurements and growth models were used to better understand seasonal hydrodynamics, surface area-to-volume relations, winter water availability, and more permanent changes related to geomorphic change. Together, these results describe how lakes vary seasonally and annually in two critical areas of the NPRA and provide simple models to help better predict variation in lake-water supply. Our findings suggest that both overestimation and underestimation of actual available winter water volume may occur regularly, and this understanding may help better inform management strategies as future resource use expands in the NPRA.

  1. Arctic lake physical processes and regimes with implications for winter water availability and management in the national petroleum reserve alaska

    USGS Publications Warehouse

    Jones, Benjamin M.; Arp, C.D.; Hinkel, Kenneth M.; Beck, R.A.; Schmutz, J.A.; Winston, B.

    2009-01-01

    Lakes are dominant landforms in the National Petroleum Reserve Alaska (NPRA) as well as important social and ecological resources. Of recent importance is the management of these freshwater ecosystems because lakes deeper than maximum ice thickness provide an important and often sole source of liquid water for aquatic biota, villages, and industry during winter. To better understand seasonal and annual hydrodynamics in the context of lake morphometry, we analyzed lakes in two adjacent areas where winter water use is expected to increase in the near future because of industrial expansion. Landsat Thematic Mapper and Enhanced Thematic Mapper Plus imagery acquired between 1985 and 2007 were analyzed and compared with climate data to understand interannual variability. Measured changes in lake area extent varied by 0.6% and were significantly correlated to total precipitation in the preceding 12 months (p < 0.05). Using this relation, the modeled lake area extent from 1985 to 2007 showed no long-term trends. In addition, high-resolution aerial photography, bathymetric surveys, water-level monitoring, and lake-ice thickness measurements and growth models were used to better understand seasonal hydrodynamics, surface area-to-volume relations, winter water availability, and more permanent changes related to geomorphic change. Together, these results describe how lakes vary seasonally and annually in two critical areas of the NPRA and provide simple models to help better predict variation in lake-water supply. Our findings suggest that both overestimation and underestimation of actual available winter water volume may occur regularly, and this understanding may help better inform management strategies as future resource use expands in the NPRA. ?? 2008 Springer Science+Business Media, LLC.

  2. Assessment of the spatial extent and height of flooding in Lake Champlain during May 2011, using satellite remote sensing and ground-based information

    USGS Publications Warehouse

    Bjerklie, David M.; Trombley, Thomas J.; Olson, Scott A.

    2014-01-01

    Landsat 5 and moderate resolution imaging spectro-radiometer satellite imagery were used to map the area of inundation of Lake Champlain, which forms part of the border between New York and Vermont, during May 2011. During this month, the lake’s water levels were record high values not observed in the previous 150 years. Lake inundation area determined from the satellite imagery is correlated with lake stage measured at three U.S. Geological Survey lake level gages to provide estimates of lake area at different lake levels (stage/area rating) and also compared with the levels of the high-water marks (HWMs) located on the Vermont side of the lake. The rating developed from the imagery shows a somewhat different relation than a similar stage/area rating developed from a medium-resolution digital elevation model (DEM) of the region. According to the rating derived from the imagery, the lake surface area during the peak lake level increased by about 17 percent above the average or “normal” lake level. By using a comparable rating developed from the DEM, the increase above average is estimated to be about 12 percent. The northern part of the lake (north of Burlington) showed the largest amount of flooding. Based on intersecting the inundation maps with the medium-resolution DEM, lake levels were not uniform around the lake. This is also evident from the lake level gage measurements and HWMs. The gage data indicate differences up to 0.5 feet between the northern and southern end of the lake. Additionally, the gage data show day-to-day and intradaily variation of the same range (0.5 foot). The high-water mark observations show differences up to 2 feet around the lake, with the highest level generally along the south- and west-facing shorelines. The data suggest that during most of May 2011, water levels were slightly higher and less variable in the northern part of the lake. These phenomena may be caused by wind effects as well as proximity to major river inputs to the lake. The inundation areas generated from the imagery generally coincide with flood mapping as estimated by the Federal Emergency Management Agency (FEMA) and shown on its digital flood insurance rate maps. Where areas in the flood inundation map derived from the imagery and the FEMA estimated flooded areas differ substantially, this difference may be due to differences between the flood magnitude at the time of the image and the assumed flood condition used for the FEMA modeling and mapping, wind/storage effects not accounted for by the FEMA modeling, and the resolution of the image compared to the DEM used in the FEMA mapping.

  3. A rare Uroglena bloom in Beaver Lake, Arkansas, spring 2015

    USGS Publications Warehouse

    Green, William R.; Hufhines, Brad

    2017-01-01

    A combination of factors triggered a Uroglena volvox bloom and taste and odor event in Beaver Lake, a water-supply reservoir in northwest Arkansas, in late April 2015. Factors contributing to the bloom included increased rainfall and runoff containing increased concentrations of dissolved organic carbon, followed by a stable pool, low nutrient concentrations, and an expansion of lake surface area and littoral zone. This was the first time U. volvox was identified in Beaver Lake and the first time it was recognized as a source of taste and odor. Routine water quality samples happened to be collected by the US Geological Survey and the Beaver Water District throughout the reservoir during the bloom—. Higher than normal rainfall in March 2015 increased the pool elevation in Beaver Lake by 2.3 m (by early April), increased the surface area by 10%, and increased the littoral zone by 1214 ha; these conditions persisted for 38 days, resulting from flood water being retained behind the dam. Monitoring programs that cover a wide range of reservoir features, including dissolved organic carbon, zooplankton, and phytoplankton, are valuable in explaining unusual events such as this Uroglena bloom.

  4. Geophysical characterization of the role of fault and fracture systems for recharging groundwater aquifers from surface water of Lake Nasser

    NASA Astrophysics Data System (ADS)

    Mansour, Khamis; Omar, Khaled; Ali, Kamal; Abdel Zaher, Mohamed

    2018-06-01

    The role of the fracture system is important for enhancing the recharge or discharge of fluids in the subsurface reservoir. The Lake Nasser is consider one of the largest artificial lakes all over the world and contains huge bulk of storage water. In this study, the influence of fracture zones on subsurface fluid flow in groundwater reservoirs is investigated using geophysical techniques including seismicity, geoelectric and gravity data. These data have been utilized for exploring structural structure in south west Lake Nasser, and subsurface discontinuities (joints or faults) notwithstanding its related fracture systems. Seismicity investigation gave us the comprehension of the dynamic geological structure sets and proposing the main recharging paths for the Nubian aquifer from Lake Nasser surface water. Processing and modelling of aerogravity data show that the greater thickness of sedimentary cover (700 m) is located eastward and northward while basement outcrops occur at Umm Shaghir and Al Asr areas. Sixty-nine vertical electrical soundings (VES's) were used to delineate the subsurface geoelectric layers along eight profiles that help to realize the subsurface geological structure behind the hydrogeological conditions of the studied area.

  5. Integrative investigations on sediments in the Belauer See catchment (northern Germany)

    NASA Astrophysics Data System (ADS)

    Dreibrodt, Stefan

    2015-04-01

    The Holocene history of lake development, catchment vegetation, soil formation and human impact since the onset of the Neolithic period was reconstructed via the analysis of sediment sequences at Lake Belau (northern Germany). The chronology of the annually laminated lake sediment sequence was established via varve counts, radiocarbon dating and tephra analysis. Sequences of colluvial sediments and buried soils studied in 19 large exposures and supplementing auger cores within the lake catchment area were dated via radiocarbon dating and archaeological dating of embedded artifacts. The long term development of the lake status was found to be strongly influenced by local human activity. This is indicated by coincidence of phases of landscape openness deduced from pollen data with input of detritus and solutes into the lake. A comparison with palaeo-climate reconstructions reveals that calcite precipitation in the lake reflects climate variability at least to a certain degree. Calibrating the sediment record of the sub-recent lake sediments (micro-facies) on limnological and meteorological records discovered the influence of the NAO as well as solar activity on the limnological processes during the last century reflected by distinguished sedimentation patterns. A comparative study of additional laminated surface sediment sequences from northern Germany corroborates the results. A high resolution reconstruction of Neolithic weather conditions in northern Germany based on the varves of Lake Belau and Lake Poggensee was facilitated by the calibration. The quantitative records of sediments originating from soil erosion (colluvial sediments, allochthonous input into the lake) illustrate the dominance of short distance surface processes (slopes) acting in Holocene mid-latitude landscapes. Coincidence of gully incision in the lake catchment area and increased allochthonous input into the lake indicates the former occurrence of hydrological high energy runoff events (e. g. in the 14th century or at ca. 200 cal BC) whose regional significance is testable via comparative investigations in additional lake catchments.

  6. The High Arctic's Only Great Lake Is Succumbing To Climate Warming

    NASA Astrophysics Data System (ADS)

    St Louis, V. L.; Lehnherr, I.; Schiff, S. L.; Sharp, M. J.; Smol, J. P.; Muir, D.; Gardner, A. S.; Tarnocai, C.; St Pierre, K.; Michelutti, N.; Emmerton, C. A.; Mortimer, C.; Talbot, C.; Wiklund, J.

    2016-12-01

    Lake Hazen, located within Quttinirpaaq National Park on northern Ellesmere Island (Nunavut, Canada), is the largest lake by volume north of the Arctic Circle and the High Arctic's only true Great Lake. Lake Hazen has a maximum depth of 267 m, a surface area of 540 km2 and a 8400 km2 watershed that is 1/3 glaciated. The climate of the Lake Hazen watershed has experienced a recent strong warming trend of 0.21 °C yr-1 from 2000-2012. During this period, modeled glacier mass-balance values showed a distinct shift from net annual mass gain of 0.3 Gt to a net annual mass loss of up to 1.4 Gt beginning in 2007-2008. Recent warming of soils (0.14 oC yr-1) and deepening of the active layer in the Lake Hazen watershed have also occurred. Rising temperatures had important consequences for summer lake ice cover: the ice-free area on the lake increased by an average of 3 km2 yr-1 from 2000 to 2012, and full ice-off on Lake Hazen became more frequent, from 60% of the years between 1985-95 to 88% of the years between 2006-12. The 250 year sediment record obtained from the floor of Lake Hazen showed that, in the past 15 years, changes in diatom species % abundance, sedimentation rates, geological inputs from the catchment, the abundance of redox sensitive elements such as Fe and Mn in the sediments, and fluxes of organic carbon and contaminants are historically unprecedented and consistent with the observed trends of rising surface temperatures, increasing glacial melt and runoff, and decreasing summer lake ice cover. These changes have important implications for in-lake processes that pertain to ecosystem net productivity, and the cycling of carbon, nutrients and contaminants. We demonstrate that even more resilient ecosystems such as very large lakes are exhibiting regime shifts due to climate change and entering new ecological states.

  7. Mountain Lake, Presidio National Park, San Francisco: Paleoenvironment, heavy metal contamination, sedimentary record rescue, remediation, and public outreach

    NASA Astrophysics Data System (ADS)

    Myrbo, A.; Rodysill, J. R.; Jones, K.; Reidy, L. M.

    2014-12-01

    Sediment cores from Mountain Lake, a small natural lake in Presidio National Park, San Francisco, CA, provide a record of Bay Area environmental change spanning the past 2000 years, and of unusually high heavy metal contamination in the last century (Reidy 2001). In 2013, partial dredging of the lake removed the upper two meters of lake sediment as part of a remediation effort. Prior to dredging, long and short cores spatially covering the lake and representing deep and shallow environments were recovered from the lake to preserve the paleoenvironmental record of one of the only natural lakes on the San Francisco Peninsula. The cores are curated at LacCore and are available for research by the scientific community. Mountain Lake formed in an interdunal depression and was shallow and fluctuating in its first few hundred years. Lake level rise and inundation of a larger area was followed by lowstands under drier conditions around 550-700 and 1300 CE. Nonnative taxa and cultivars appeared at the time of Spanish settlement in the late 18th century, and the lake underwent eutrophication due to livestock pasturing. U.S. Army landscaping introduced trees to the watershed in the late 19th century. The upper ~1m of sediments document unusually high heavy metal contamination, especially for lead and zinc, caused by the construction and heavy use of Highway 1 on the lake shore. Lead levels peak in 1975 and decline towards the surface, reflecting the history of leaded gasoline use in California. Zinc is derived mainly from automobile tires, and follows a pattern similar to that of lead, but continues to increase towards the surface. Ongoing research includes additional radiocarbon dating and detailed lithological analysis to form the basis of lake-level reconstruction and archeological investigations. Because the Presidio archaeological record does not record human habitation in the area until approximately 1300 years before present, the core analysis also has the potential to determine whether people lived at the tip of the SF peninsula as early as 2000 BP. In October 2014 the Presidio Trust opened a Heritage Gallery that interprets the cultural and natural history of the park for the public. The Mountain Lake sedimentary record is an important component of this exhibit, which includes an epoxy-embedded core from the lake.

  8. Characterizing seasonal and diel vertical movement and habitat use of lake whitefish (Coregonus clupeaformis) in Clear Lake, Maine

    USGS Publications Warehouse

    Zydlewski, Joseph D.; Gorsky, Dimitry; Balsey, David

    2016-01-01

    Seasonal and daily vertical activity of lake whitefish Coregonus clupeaformis was studied in Clear Lake, Maine (253 ha), using acoustic telemetry from November 2004 to June 2009. Twenty adult lake whitefish were tagged with acoustic tags that had either a depth sensor or both depth and temperature sensors to assess vertical habitat use at a seasonal and daily resolution. Vertical habitat selection varied seasonally and was strongly influenced by temperature. Between December and April, when the lake was covered with ice, surface temperature was below 2°C and tagged individuals occupied deep areas of the lake (∼15 m). After ice-out, fish ascended into shallow waters (∼5 m), responding to increased water temperature and possibly to greater foraging opportunity. When surface water temperatures exceeded 20°C, fish descended below the developing thermocline (∼9 m), where they remained until surface temperatures fell below 20°C; fish then ascended into shallower depths, presumably for feeding and spawning. Through the winter, fish remained in thermal habitats that were warmer than the surface temperatures; in the summer, they selected depths with thermal habitats below 15°C. Though the amplitude varied greatly across seasons, lake whitefish displayed a strong diurnal pattern of activity as measured by vertical velocities. Fish were twofold more active during spring, summer, and fall than during winter. Lake whitefish exhibited diel vertical migrations, rising in the water column during nighttime and occupying deeper waters during the day. This pattern was more pronounced in the spring and fall and far less prominent during winter and summer. The strong linkage between temperature and habitat use may limit the current range of lake whitefish and may be directly impacted by climatic change.

  9. Using dual isotopes to evaluate sources and transformations of nitrate in the West Lake watershed, eastern China.

    PubMed

    Jin, Zanfang; Qin, Xue; Chen, Lingxiao; Jin, Mantong; Li, Feili

    2015-01-01

    The West Lake is a World Heritage site in the West Lake watershed in eastern China. In this study, the hydrogeological and dual isotopic approaches were integrated to evaluate the seasonal and spatial variations of nitrate (NO3(-)) in the West Lake watershed, and to characterize NO3(-) sources and transformations. The results revealed that the geochemical facies of the water samples were dominated by Ca(2+)+Na(+)-HCO3(-)+SO4(2)(-) in the surface water and transfer water, Ca(2+)+Na(+)-HCO3(-) and Ca(2+)+Na(+)-SO4(2-) in the groundwater, which most likely reflect natural reactions and anthropogenic inputs. About 13% of the groundwater samples containing NO3(-) exceeded the World Health Organization (WHO) standard of 10 mg N L(-1). NO3(-) was the dominant form of total nitrogen (TN) and was the main surface water contaminant in the West Lake watershed. The δ(15)NNO3 and δ(18)ONO3 values indicated that the dominant NO3(-) sources in surface water were soil nitrogen (soil N) and chemical fertilizers, while the main NO3(-) sources in groundwater were soil N from the forest, chemical fertilizers and manure in the tea garden, domestic sewage from the small, old residential area in the forest as well as urban areas. The distribution of NO3(-) in groundwater was strongly influenced by land use. Results also suggest that there was significant nitrification in surface water and groundwater in the West Lake watershed, and that there were also denitrification processes in groundwater. The annual net fluxes of TN, NO3(-), and NH4(+) into the West Lake were 2.0×10(4), 4.0×10(3), and 1.31×10(4) kg as N, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Four years of continuous monitoring of the Meirama end-pit lake and its impact in the definition of future uses.

    PubMed

    Delgado-Martin, J; Juncosa-Rivera, R; Falcón-Suárez, I; Canal-Vila, J

    2013-11-01

    Following the technical closure of the brown lignite Meirama mine (NW Spain) in April 2008, the reclamation of the mined area is being accomplished with the controlled flooding of its large pit. During the first 7 months of flooding, the sequential arrest of the ground water dewatering system led to the growth of an acidic water body of about 2 hm3. Since October 2008, the surface waters from some local streams have been diverted towards the pit so that these have become the major water input in the flooding process. Surface water has promoted a major change in the chemical composition of the lake water so that, at present, its surface has a circum neutral pH, net alkalinity, and low conductivity. At present, the lake has slightly more than one half of its final volume, and it is expected the overflow in 3 to 3.5 years. The lake is meromictic, with a sharp chemocline separating the acidic monimolimnion (pH≈3.2, acidity≈150 mg CaCO3/L, κ 25≈2.4 mS/cm) from the main water body (pH≈6.5, alkalinity≈15 mg CaCO3/L, κ 25≈0.3 mS/cm). Oxygen is being depleted at the bottom of the lake so that the monimolimnion became anoxic in January 2011. Above the chemocline, the composition of the lake is similar, but not identical, to that of the flooding stream waters. Close to the surface, some constituents (pH, metals) show strong seasonal variations in coincidence with the phytoplankton growing periods. Those parameters whose limits are legally prescribed comply with the corresponding water quality standards, and they are also consistent with the forecasting results obtained in early modeling. At present, a project considering the construction of an uptake tunnel to exploit the lake is being developed for the emergency water supply of the metropolitan area of A Coruña.

  11. Spatiotemporal variability of carbon dioxide and methane in a eutrophic lake

    NASA Astrophysics Data System (ADS)

    Loken, Luke; Crawford, John; Schramm, Paul; Stadler, Philipp; Stanley, Emily

    2017-04-01

    Lakes are important regulators of global carbon cycling and conduits of greenhouse gases to the atmosphere; however, most efflux estimates for individual lakes are based on extrapolations from a single location. Within-lake variability in carbon dioxide (CO2) and methane (CH4) arises from differences in water sources, physical mixing, and local transformations; all of which can be influenced by anthropogenic disturbances and vary at multiple temporal and spatial scales. During the 2016 open water season (March - December), we mapped surface water concentrations of CO2 and CH4 weekly in a eutrophic lake (Lake Mendota, WI, USA), which has a predominately agricultural and urban watershed. In total we produced 26 maps of each gas based on 10,000 point measurements distributed across the lake surface. Both gases displayed relatively consistent spatial patterns over the stratified period but exhibited remarkable heterogeneity on each sample date. CO2 was generally undersaturated (global mean: 0.84X atmospheric saturation) throughout the lake's pelagic zone and often differed near river inlets and shorelines. The lake was routinely extremely supersaturated with CH4 (global mean: 105X atmospheric saturation) with greater concentrations in littoral areas that contained organic-rich sediments. During fall mixis, both CO2 and CH4 increased substantially, and concentrations were not uniform across the lake surface. CO2 and CH4 were higher on the upwind side of the lake due to upwelling of enriched hypolimnetic water. While the lake acted as a modest sink for atmospheric CO2 during the stratified period, the lake released substantial amounts of CO2 during turnover and continually emitted CH4, offsetting any reduction in atmospheric warming potential from summertime CO2 uptake. These data-rich maps illustrate how lake-wide surface concentrations and lake-scale efflux estimates based on single point measurements diverge from spatially weighted calculations. Both gases are not well represented by a sample collected at lake's central buoy, and thus, extrapolations from a single sampling location may not be adequate to assess lake-wide CO2 and CH4 dynamics in human-dominated landscapes.

  12. Groundwater flux and nutrient loading in the northeast section of Bear Lake, Muskegon County, Michigan, 2015

    USGS Publications Warehouse

    Totten, Alexander R.; Maurer, Jessica A.; Duris, Joseph W.

    2017-11-30

    Bear Lake in North Muskegon, Michigan, is listed as part of the Muskegon Lake area of concern as designated by the U.S. Environmental Protection Agency. This area of concern was designated as a result of eutrophication and beneficial use impairments. On the northeast end of Bear Lake, two man-made retention ponds (Willbrandt Pond East and Willbrandt Pond West), formerly used for celery farming, may contribute nutrients to Bear Lake. Willbrandt Ponds (East and West) were previously muck fields that were actively used for celery farming from the early 1900s until 2002. The restoration and reconnection of the Willbrandt Ponds into Bear Lake prompted concerns of groundwater nutrient loading into Bear Lake. Studies done by the State of Michigan and Grand Valley State University revised initial internal phosphorus load estimates and indicated an imbalance in the phosphorus budget in Bear Lake. From June through November 2015, the U.S. Geological Survey (USGS) did an investigative study to quantify the load of nutrients from shallow groundwater around the Willbrandt Ponds in an effort to update the phosphorus budget to Bear Lake. Seven sampling locations were established, including five shallow groundwater wells and two surface-water sites, in the Willbrandt pond study area and Bear Lake. A total of 12 nutrient samples and discrete water-level measurements were collected from each site from June through November 2015. Continuous water-level data were recorded for both surface-water monitoring locations for the entire sampling period.Water-level data indicated that Willbrandt Pond West had the highest average water-level elevation of all sites monitored, which indicated the general direction of flux is from Willbrandt Pond West to Bear Lake. Nutrient and chloride loading from Willbrandt Pond West to Bear Lake was calculated using two distinct methods: Dupuit and direct seepage methods. Shallow groundwater loading calculations were determined by using groundwater levels to first determine a flux of shallow groundwater, then nutrient concentrations to determine a load. It was determined that Willbrandt Pond East and Willbrandt Pond West contributed between 2 to 4 percent of the total annual phosphorus load to Bear Lake by way of shallow groundwater flow. Annual loads calculated for other constituents include orthophosphate (40–100 pounds per year [lb P/yr]), total nitrogen (200–830 lb/yr), chloride (12,700–32,100 lb/yr), and ammonia (130–670 lb N/yr). Study results indicated that mean groundwater and surface-water nutrient concentrations calculated in this study were higher than reported Michigan statewide values. The data collected in this study allow understanding of groundwater nutrient loading into Bear Lake in an effort to help inform future restoration and management decisions.

  13. Depth estimation for ordinary high water of streams in the Mobile District of the U.S. Army Corps of Engineers, Alabama and adjacent states

    USGS Publications Warehouse

    Harkins, Joe R.; Green, Mark E.

    1981-01-01

    Drainage areas for about 1,600 surface-water sites on streams and lakes in Florida are contained in this report. The sites are generally either U.S. Geological Survey gaging stations or the mouths of gaged streas. Each site is identified by latitude and longitude, by the general stream type, and by the U.S. Geological Survey 7.5-minute topographic map on which it can be located. The gaging stations are furhter identified by a downstream order number, a county code, and a nearby city or town. In addition to drainage areas, the surface areas of lakes are shown for the elevation given on the topographic map. These data were retrieved from the Surface Water Index developed and maintained by the Hydrologic Surveillance section of the Florida District Office, U.S. Geological Survey. (USGS)

  14. Remote sensing of ephemeral water bodies in western Niger

    USGS Publications Warehouse

    Verdin, J.P.

    1996-01-01

    Research was undertaken to evaluate the feasibility of monitoring the small ephemeral water bodies of the Sahel with the 1.1 km resolution data of the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR). Twenty-one lakes of western Niger with good ground observation records were selected for examination. Thematic Mapper images from 1988 were first analysed to determine surface areas and temperature differences between water and adjacent land. Six AVHRR scenes from the 1988-89 dry season were then studied. It was found that a lake can be monitored until its surface area drops below 10 ha, in most cases. Furthermore, with prior knowledge of the location and shape of a water body, its surface area can be estimated from AVHRR band 5 data to within about 10 ha. These results are explained by the sharp temperature contrast between water and land, on the order of 13?? C.

  15. Tracking fine-scale seasonal evolution of surface water extent in Central Alaska and the Canadian Shield

    NASA Astrophysics Data System (ADS)

    Cooley, S. W.; Smith, L. C.; Pitcher, L. H.; Pavelsky, T.; Topp, S.

    2017-12-01

    Quantifying spatial and temporal variability in surface water storage at high latitudes is critical for assessing environmental sensitivity to climate change. Traditionally the tradeoff between high spatial and high temporal resolution space-borne optical imagery has limited the ability to track fine-scale changes in surface water extent. However, the recent launch of hundreds of earth-imaging CubeSats by commercial satellite companies such as Planet opens up new possibilities for monitoring surface water from space. In this study we present a comparison of seasonal evolution of surface water extent in two study areas with differing geologic, hydrologic and permafrost regimes, namely, the Yukon Flats in Central Alaska and the Canadian Shield north of Yellowknife, N.W.T. Using near-daily 3m Planet CubeSat imagery, we track individual lake surface area from break-up to freeze-up during summer 2017 and quantify the spatial and temporal variability in inundation extent. We validate our water delineation method and inundation extent time series using WorldView imagery, coincident in situ lake shoreline mapping and pressure transducer data for 19 lakes in the Northwest Territories and Alaska collected during the NASA Arctic Boreal Vulnerability Experiment (ABoVE) 2017 field campaign. The results of this analysis demonstrate the value of CubeSat imagery for dynamic surface water research particularly at high latitudes and illuminate fine-scale drivers of cold regions surface water extent.

  16. Monitoring Earth's reservoir and lake dynamics from space

    NASA Astrophysics Data System (ADS)

    Donchyts, G.; Eilander, D.; Schellekens, J.; Winsemius, H.; Gorelick, N.; Erickson, T.; Van De Giesen, N.

    2016-12-01

    Reservoirs and lakes constitute about 90% of the Earth's fresh surface water. They play a major role in the water cycle and are critical for the ever increasing demands of the world's growing population. Water from reservoirs is used for agricultural, industrial, domestic, and other purposes. Current digital databases of lakes and reservoirs are scarce, mainly providing only descriptive and static properties of the reservoirs. The Global Reservoir and Dam (GRanD) database contains almost 7000 entries while OpenStreetMap counts more than 500 000 entries tagged as a reservoir. In the last decade several research efforts already focused on accurate estimates of surface water dynamics, mainly using satellite altimetry, However, currently they are limited only to less than 1000 (mostly large) water bodies. Our approach is based on three main components. Firstly, a novel method, allowing automated and accurate estimation of surface area from (partially) cloud-free optical multispectral or radar satellite imagery. The algorithm uses satellite imagery measured by Landsat, Sentinel and MODIS missions. Secondly, a database to store reservoir static and dynamic parameters. Thirdly, a web-based tool, built on top of Google Earth Engine infrastructure. The tool allows estimation of surface area for lakes and reservoirs at planetary-scale at high spatial and temporal resolution. A prototype version of the method, database, and tool will be presented as well as validation using in-situ measurements.

  17. Thermal Pollution Mathematical Model. Volume 2; Verification of One-Dimensional Numerical Model at Lake Keowee

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Sengupta, S.; Nwadike, E. V.

    1980-01-01

    A one dimensional model for studying the thermal dynamics of cooling lakes was developed and verified. The model is essentially a set of partial differential equations which are solved by finite difference methods. The model includes the effects of variation of area with depth, surface heating due to solar radiation absorbed at the upper layer, and internal heating due to the transmission of solar radiation to the sub-surface layers. The exchange of mechanical energy between the lake and the atmosphere is included through the coupling of thermal diffusivity and wind speed. The effects of discharge and intake by power plants are also included. The numerical model was calibrated by applying it to Cayuga Lake. The model was then verified through a long term simulation using Lake Keowee data base. The comparison between measured and predicted vertical temperature profiles for the nine years is good. The physical limnology of Lake Keowee is presented through a set of graphical representations of the measured data base.

  18. Bathymetry of Lake William C. Bowen and Municipal Reservoir #1, Spartanburg County, South Carolina, 2008

    USGS Publications Warehouse

    Nagle, D.D.; Campbell, B.G.; Lowery, M.A.

    2009-01-01

    The increasing use and importance of lakes for water supply to communities enhance the need for an accurate methodology to determine lake bathymetry and storage capacity. A global positioning receiver and a fathometer were used to collect position data and water depth in February 2008 at Lake William C. Bowen and Municipal Reservoir #1, Spartanburg County, South Carolina. All collected data were imported into a geographic information system database. A bathymetric surface model, contour map, and stage-area and -volume relations were created from the geographic information database.

  19. The Dynamics of Laurentian Great Lakes Surface Energy Budgets

    NASA Astrophysics Data System (ADS)

    Spence, C.; Blanken, P.; Lenters, J. D.; Gronewold, A.; Kerkez, B.; Xue, P.; Froelich, N.

    2015-12-01

    The Laurentian Great Lakes constitute the largest freshwater surface in the world and are a valuable North American natural and socio-economic resource. In response to calls for improved monitoring and research on the energy and water budgets of the lakes, there has been a growing ensemble of in situ measurements - including offshore eddy flux towers, buoy-based sensors, and vessel-based platforms -deployed through an ongoing, bi-national collaboration known as the Great Lakes Evaporation Network (GLEN). The objective of GLEN is to reduce uncertainty in Great Lakes seasonal and 6-month water level forecasts, as well as climate change projections of the surface energy balance and water level fluctuations. Although It remains challenging to quantify and scale energy budgets and fluxes over such large water bodies, this presentation will report on recent successes in three areas: First, in estimating evaporation rates over each of the Great Lakes; Second, defining evaporation variability among the lakes, especially in winter and; Third, explaining the interaction between ice cover, water temperature, and evaporation across a variety of temporal and spatial scales. Research gaps remain, particularly those related to spatial variability and scaling of turbulent fluxes, so the presentation will also describe how this will be addressed with enhanced instrument and platform arrays.

  20. Lateral and subsurface flows impact arctic coastal plain lake water budgets

    USGS Publications Warehouse

    Koch, Joshua C.

    2016-01-01

    Arctic thaw lakes are an important source of water for aquatic ecosystems, wildlife, and humans. Many recent studies have observed changes in Arctic surface waters related to climate warming and permafrost thaw; however, explaining the trends and predicting future responses to warming is difficult without a stronger fundamental understanding of Arctic lake water budgets. By measuring and simulating surface and subsurface hydrologic fluxes, this work quantified the water budgets of three lakes with varying levels of seasonal drainage, and tested the hypothesis that lateral and subsurface flows are a major component of the post-snowmelt water budgets. A water budget focused only on post-snowmelt surface water fluxes (stream discharge, precipitation, and evaporation) could not close the budget for two of three lakes, even when uncertainty in input parameters was rigorously considered using a Monte Carlo approach. The water budgets indicated large, positive residuals, consistent with up to 70% of mid-summer inflows entering lakes from lateral fluxes. Lateral inflows and outflows were simulated based on three processes; supra-permafrost subsurface inflows from basin-edge polygonal ground, and exchange between seasonally drained lakes and their drained margins through runoff and evapotranspiration. Measurements and simulations indicate that rapid subsurface flow through highly conductive flowpaths in the polygonal ground can explain the majority of the inflow. Drained lakes were hydrologically connected to marshy areas on the lake margins, receiving water from runoff following precipitation and losing up to 38% of lake efflux to drained margin evapotranspiration. Lateral fluxes can be a major part of Arctic thaw lake water budgets and a major control on summertime lake water levels. Incorporating these dynamics into models will improve our ability to predict lake volume changes, solute fluxes, and habitat availability in the changing Arctic.

  1. Drainage network structure and hydrologic behavior of three lake-rich watersheds on the Arctic Coastal Plain, Alaska

    USGS Publications Warehouse

    Arp, C.D.; Whitman, M.S.; Jones, Benjamin M.; Kemnitz, R.; Grosse, G.; Urban, F.E.

    2012-01-01

    Watersheds draining the Arctic Coastal Plain (ACP) of Alaska are dominated by permafrost and snowmelt runoff that create abundant surface storage in the form of lakes, wetlands, and beaded streams. These surface water elements compose complex drainage networks that affect aquatic ecosystem connectivity and hydrologic behavior. The 4676 km2 Fish Creek drainage basin is composed of three watersheds that represent a gradient of the ACP landscape with varying extents of eolian, lacustrine, and fluvial landforms. In each watershed, we analyzed 2.5-m-resolution aerial photography, a 5-m digital elevation model, and river gauging and climate records to better understand ACP watershed structure and processes. We show that connected lakes accounted for 19 to 26% of drainage density among watersheds and most all channels initiate from lake basins in the form of beaded streams. Of the > 2500 lakes in these watersheds, 33% have perennial streamflow connectivity, and these represent 66% of total lake area extent. Deeper lakes with over-wintering habitat were more abundant in the watershed with eolian sand deposits, while the watershed with marine silt deposits contained a greater extent of beaded streams and shallow thermokarst lakes that provide essential summer feeding habitat. Comparison of flow regimes among watersheds showed that higher lake extent and lower drained lake-basin extent corresponded with lower snowmelt and higher baseflow runoff. Variation in baseflow runoff among watersheds was most pronounced during drought conditions in 2007 with corresponding reduction in snowmelt peak flows the following year. Comparison with other Arctic watersheds indicates that lake area extent corresponds to slower recession of both snowmelt and baseflow runoff. These analyses help refine our understanding of how Arctic watersheds are structured and function hydrologically, emphasizing the important role of lake basins and suggesting how future lake change may impact hydrologic processes.

  2. Investigation of lagoon lakes in Kocacay delta by using remote sensing method.

    PubMed

    Irtem, Emel; Sacin, Yener

    2012-04-01

    Coasts are areas that are under the influence of the interaction of the air, water and land and attract attention with the abundance of their natural resources and therefore are subjected to excessive usage. This excessive usage may disturb the sensitive balance of the coast ecosystem. In this study, the changes in Arapçiftligi, Poyraz, Dalyan lakes area found in Kocacay delta located in the south coast of Marmara sea was evaluated between the periods of 2000 to 2007 with remote sensing method. These lakes, located on the shores, have a very sensitive naturally dynamic balance and very importance in terms of natural surroundings and the coastal zones management plan. It must be known the change of the lakes mentioned above area according to years. Research and applications have demonstrated the advantages of remote sensing and geographic information system techiques on river,delta, lake, lagoon lake, sensitivite areas in a lakeshore, coastal erosion etc. monitoring and management. In the study, we benefited from Erdas and Intergraph-Geomedia 6.1 image processing and GIS, and also from AutoCAD 2007 and NetCAD 4.0 computer-aided design (CAD) software. For 2000, 2001, 2005 and 2007 years (4 number) Landsat-5 TM satellite images belonging to the region were used. As a result of the study, Arapçiftligi, Dalyan and Poyraz lake areas, number of islets that are seen in the lakes were given in respect to years. Arapçiftligi lake shrank 29.5% in size in the years 2000 and 2007. The fact that the lake continued to get smaller in size even in periods of high precipitation may be due to the sediment flowing from the agricultural fields established close to the lake area. Dalyan and Poyraz lakes lost 60% in terms of their surface area in the years 2000 and 2007. In 2000-2001 periods, Dalyan and Poyraz lakes increased in size by 3.2%. The reason for this could be the excessive precipitation and the fact that the seawater from Marmara sea seeps into the lake. Protection of the natural balance of the lagoons can be possible by using a monitoring programme to be set in connection with a healthy, systematic and manageable data system.

  3. BOREAS HYD-5 Winter Surface Flux Data

    NASA Technical Reports Server (NTRS)

    Harding, Richard; Hall, Forrest G. (Editor); Huemmrich, Karl Fred (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The BOREAS HYD-5 team collected tower flux, surface meteorological, and surface temperature data on a frozen lake (Namekus Lake) and in a mature jack pine forest in the Beartrap Creek watershed. Both sites were located in the BOREAS SSA. The objective of this study was to characterize the winter energy and water vapor fluxes, as well as related properties (such as snow density, depth, temperature, and melt) for forested and nonforested areas of the boreal forest. Data were collected on Namekus Lake in the winters of 1994 and 1996, and at Beartrap Creek in the winter of 1994 only. The data are available in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  4. STS-65 Earth observation of Lake Chad, Africa, taken aboard Columbia, OV-102

    NASA Technical Reports Server (NTRS)

    1994-01-01

    STS-65 Earth observation taken aboard Columbia, Orbiter Vehicle (OV) 102, shows Lake Chad, Africa. This is another long term ecological monitoring site for NASA scientists. Lake Chad was first photographed from space in 1965. A 25-year length-of-record data set exists for this environmentally important area. A number of these scenes have been digitized, rectified, classified and results show that the lake area has been shrinking and only 15% to 20% of the surface water is visible on space images. NASA's objective in monitoring this lake is to document the intra- and interannual areal changes of the largest standing water body in the Sahelian biome of North Africa. These areal changes are an indicator of the presence or absence of drought across the arguably overpopulated, overgrazed, and over biological carrying capacity limits nations of the Sahel.

  5. Simulation of the shallow groundwater-flow system in the Forest County Potawatomi Community, Forest County, Wisconsin

    USGS Publications Warehouse

    Fienen, Michael N.; Saad, David A.; Juckem, Paul F.

    2013-01-01

    The shallow groundwater system in the Forest County Potawatomi Comminity, Forest County, Wisconsin, was simulated by expanding and recalibrating a previously calibrated regional model. The existing model was updated using newly collected water-level measurements, inclusion of surface-water features beyond the previous near-field boundary, and refinements to surface-water features. The updated model then was used to calculate the area contributing recharge for seven existing and three proposed pumping locations on lands of the Forest County Potawatomi Community. The existing wells were the subject of a 2004 source-water evaluation in which areas contributing recharge were calculated using the fixed-radius method. The motivation for the present (2012) project was to improve the level of detail of areas contributing recharge for the existing wells and to provide similar analysis for the proposed wells. Delineated 5- and 10-year areas contributing recharge for existing and proposed wells extend from the areas of pumping to delineate the area at the surface contributing recharge to the wells. Steady-state pumping was simulated for two scenarios: a base-pumping scenario using pumping rates that reflect what the Community currently (2012) pumps (or plans to in the case of proposed wells), and a high-pumping scenario in which the rate was set to the maximum expected from wells installed in this area, according to the Forest County Potawatomi Community Natural Resources Department. In general, the 10-year areas contributing recharge did not intersect surface-water bodies. The 5- and 10-year areas contributing recharge simulated at the maximum pumping rate at Bug Lake Road may intersect Bug Lake. At the casino near the Town of Carter, Wisconsin, the 10-year areas contributing recharge intersect infiltration ponds. At the Devils Lake and Lois Crow Drive wells, areas contributing recharge are near cultural features, including residences.

  6. Imaging radar observations of frozen Arctic lakes

    NASA Technical Reports Server (NTRS)

    Elachi, C.; Bryan, M. L.; Weeks, W. F.

    1976-01-01

    A synthetic aperture imaging L-band radar flown aboard the NASA CV-990 remotely sensed a number of ice-covered lakes about 48 km northwest of Bethel, Alaska. The image obtained is a high resolution, two-dimensional representation of the surface backscatter cross section, and large differences in backscatter returns are observed: homogeneous low returns, homogeneous high returns and/or low returns near lake borders, and high returns from central areas. It is suggested that a low return indicates that the lake is frozen completely to the bottom, while a high return indicates the presence of fresh water between the ice cover and the lake bed.

  7. Ice patterns and hydrothermal plumes, Lake Baikal, Russia - Insights from Space Shuttle hand-held photography

    NASA Technical Reports Server (NTRS)

    Evans, Cynthia A.; Helfert, Michael R.; Helms, David R.

    1992-01-01

    Earth photography from the Space Shuttle is used to examine the ice cover on Lake Baikal and correlate the patterns of weakened and melting ice with known hydrothermal areas in the Siberian lake. Particular zones of melted and broken ice may be surface expressions of elevated heat flow in Lake Baikal. The possibility is explored that hydrothermal vents can introduce local convective upwelling and disrupt a stable water column to the extent that the melt zones which are observed in the lake's ice cover are produced. A heat flow map and photographs of the lake are overlaid to compare specific areas of thinned or broken ice with the hot spots. The regions of known hydrothermal activity and high heat flow correlate extremely well with circular regions of thinned ice, and zones of broken and recrystallized ice. Local and regional climate data and other sources of warm water, such as river inlets, are considered.

  8. Landsat-based trend analysis of lake dynamics across northern permafrost regions

    USGS Publications Warehouse

    Nitze, Ingmar; Grosse, Guido; Jones, Benjamin M.; Arp, Christopher D.; Ulrich, Mathias; Federov, Alexander; Veremeeva, Alexandra

    2017-01-01

    Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding the underlying processes driving lake change. To date, lake change studies in permafrost regions were based on a variety of different sources, image acquisition periods and single snapshots, and localized analysis, which hinders the comparison of different regions. Here we present, a methodology based on machine-learning based classification of robust trends of multi-spectral indices of Landsat data (TM,ETM+, OLI) and object-based lake detection, to analyze and compare the individual, local and regional lake dynamics of four different study sites (Alaska North Slope, Western Alaska, Central Yakutia, Kolyma Lowland) in the northern permafrost zone from 1999 to 2014. Regional patterns of lake area change on the Alaska North Slope (-0.69%), Western Alaska (-2.82%), and Kolyma Lowland (-0.51%) largely include increases due to thermokarst lake expansion, but more dominant lake area losses due to catastrophic lake drainage events. In contrast, Central Yakutia showed a remarkable increase in lake area of 48.48%, likely resulting from warmer and wetter climate conditions over the latter half of the study period. Within all study regions, variability in lake dynamics was associated with differences in permafrost characteristics, landscape position (i.e. upland vs. lowland), and surface geology. With the global availability of Landsat data and a consistent methodology for processing the input data derived from robust trends of multi-spectral indices, we demonstrate a transferability, scalability and consistency of lake change analysis within the northern permafrost region.

  9. Large subglacial lakes in East Antarctica at the onset of fast-flowing ice streams.

    PubMed

    Bell, Robin E; Studinger, Michael; Shuman, Christopher A; Fahnestock, Mark A; Joughin, Ian

    2007-02-22

    Water plays a crucial role in ice-sheet stability and the onset of ice streams. Subglacial lake water moves between lakes and rapidly drains, causing catastrophic floods. The exact mechanisms by which subglacial lakes influence ice-sheet dynamics are unknown, however, and large subglacial lakes have not been closely associated with rapidly flowing ice streams. Here we use satellite imagery and ice-surface elevations to identify a region of subglacial lakes, similar in total area to Lake Vostok, at the onset region of the Recovery Glacier ice stream in East Antarctica and predicted by ice-sheet models. We define four lakes through extensive, flat, featureless regions of ice surface bounded by upstream troughs and downstream ridges. Using ice velocities determined using interferometric synthetic aperture radar (InSAR), we find the onset of rapid flow (moving at 20 to 30 m yr(-1)) of the tributaries to the Recovery Glacier ice stream in a 280-km-wide segment at the downslope margins of these four subglacial lakes. We conclude that the subglacial lakes initiate and maintain rapid ice flow through either active modification of the basal thermal regime of the ice sheet by lake accretion or through scouring bedrock channels in periodic drainage events. We suggest that the role of subglacial lakes needs to be considered in ice-sheet mass balance assessments.

  10. Towards monitoring surface and subsurface lakes on the Greenland Ice Sheet using Sentinel-1 SAR and Landsat-8 OLI imagery

    NASA Astrophysics Data System (ADS)

    Miles, Katie E.; Willis, Ian C.; Benedek, Corinne L.; Williamson, Andrew G.; Tedesco, Marco

    2017-07-01

    Supraglacial lakes are an important component of the Greenland Ice Sheet’s mass balance and hydrology, with their drainage affecting ice dynamics. This study uses imagery from the recently launched Sentinel-1A Synthetic Aperture Radar (SAR) satellite to investigate supraglacial lakes in West Greenland. A semi-automated algorithm is developed to detect surface lakes from Sentinel-1 images during the 2015 summer. A combined Landsat-8 and Sentinel-1 dataset, which has a comparable temporal resolution to MODIS (3 days versus daily) but a higher spatial resolution (25-40 m versus 250-500 m), is then used together with a fully-automated lake drainage detection algorithm. Rapid (< 4 days) and slow (> 4 days) drainages are investigated for both small (< 0.125 km2, the minimum size detectable by MODIS) and large (≥ 0.125 km2) lakes through the summer. Drainage events of small lakes occur at lower elevations (mean 159 m), and slightly earlier (mean 4.5 days) in the melt season than those of large lakes. The analysis is extended manually into the early winter to calculate the dates and elevations of lake freeze-through more precisely than is possible with optical imagery (mean 30 August; 1270 m mean elevation). Finally, the Sentinel-1 imagery is used to detect subsurface lakes and, for the first time, their dates of appearance and freeze-through (mean 9 August and 7 October, respectively). These subsurface lakes occur at higher elevations than the surface lakes detected in this study (mean 1593 m and 1185 m, respectively). Sentinel-1 imagery therefore provides great potential for tracking melting, water movement and freezing within both the firn zone and ablation area of the Greenland Ice Sheet.

  11. Land use impacts on lake water quality in Alytus region (Lithuania)

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo; Laukonis, Rymvidas

    2016-04-01

    Land use has important impacts on soils, surface and ground water quality. Urban agricultural areas are an important source of pollutants, which can reach lakes through surface runoff and underground circulation. Human intervention in the landscape is one of the major causes pollution and land degradation, thus it is very important to understand the impacts of and use on environment and if they have some spatial pattern (Pereira et al., 2013, 2015; Brevik et al., 2016). The identification of the spatial pattern of lakes pollution is in Alytus area (Lithuania) is fundamental, since they provide an important range of ecosystem services to local communities, including food and recreational activities. Thus, the degradation of these environments can induce important economic losses. In this context, it is import to identify the areas with high pollutant accumulation and the environmental and human factors responsible for it. The objective of this work is to study identify the amount of some important nutrients resultant from human activities in lake water quality in Alytus region (Lithuania). Alytus region is located in southern part of Lithuania and has an approximate area of 40 km2. Inside this region we analyzed several water quality parameters of 55 lakes, including, pH, electrical conductivity (EC), suspended materials (SM), water clarity (WC) biochemical oxygen demand (BDO), total phosphorous (TP), total Nitrogen (TN), dissolved organic carbon (DOC), as other environmental variables as altitude, lake maximum deep (MD), lake area and land use according Corine land cover classification (CLC2006). Previous to data analysis, data normality and homogeneity of the variances, was assessed with the Shapiro-wilk and Leven's test, respectively. The majority of the data did not respect the Gaussian distribution and the heteroscedasticity, even after a logarithmic, and box-cox transformation. Thus, in this work we used the logarithmic transformed data to do a principal component analysis (PCA), based on the correlation matrix. The loadings of factors that at least explained one of the variables were used for a hot spot analysis, in order to identify if there was a spatial pattern in the variables distribution (Pereira et al., 2010, 2016). The results showed that in Alytus region 45.5% of the land use was classified as agricultural area, 47.3% as forest and semi-natural areas, 3.3% as water bodies, 2% as artificial surfaces and 1.9% as wetlands. The water properties of the studied lakes were the follow: pH 8.3±0.41, EC 336.31±106.49 μS/cm, 9.55±3.09 mg/l, WC 2.55±1.41 meters, BDO 3.53±1.30 mg/l, TP 0.0425±0.027 mg/l, TN 0.92±0.39 mg/l, DOC 9.61±0.79 mg/l. On average, the altitude of the lakes was 113.98±17.06 meters, MD 15.98±12.08 and lake area 243.85±386.52 ha. The PCA identified three different groups (factors). The factor 1 had high loadings in MD and WC, and high negative loadings in BDS, TP, TN and SM. The factor 2 showed high negative loadings in pH, EC and DOC. Finally, the factor 3 had high positive loadings in the area of the lake and high negative loadings in altitude. The hot spot analysis carried out with the loadings of factor 1 showed that that the area at northeast of Alytus region had a significant concentration lakes with high amounts of BDS, TP, TN, and SM, and in the west an area of lakes with high WC and MD. The hot spot analysis applied to the factor 2 loadings, showed that there was a group of lakes with high pH, EC and DOC, and a cluster located in the northeast part of Alytus region with a low level of pH, EC and DOC. Finally, the hot spot analysis applied to the factor 3 loadings, identified that the areas where the high lake area were located in the northwest of the study area, and small lakes were identified in the northeast. The lakes located at high altitude were located in the northeast area and the ones at low altitude at northeast part of Alytus area. Overall, the area with lakes with high pollution are located at northwest of the study area, where the lakes were more shallow, the altitude was low and the majority of the surroundings are covered by agricultural areas. The degradation of water quality of this area may be attributed to the fertilizers and pesticides applied by farmers in this area, contributing to the degradation of water quality and the quality of the services offered by this area. References Brevik, E., Baumgarten, A., Calzolari, C., Jordan, A., Kabala, C., Miller, B., Pereira, P. Editorial Historical perspectives and future needs in soil mapping, classification and pedological modelling, Geoderma, 264, Part B, 253-255. Pereira, P., Úbeda, X., Baltrenaite, E. (2010) Mapping Total Nitrogen in ash after a Wildfire, a microplot analysis, Ekologija, 56 (3-4), 144-152. Pereira, P., Cerdà, A., Jordán, A., Bolutiene, V., Úbeda, X., Pranskevicius, M., Mataix-Solera, J. (2013) Spatio-temporal vegetation recuperation after a grassland fire in Lithuania, Procedia Environmental Sciences, 19:856-864 Pereira, P., Gimenez-Morera, A., Novara, A., Keesstra, S., Jordan, A., Masto, R.E., Cerda, A. (2015) Soil erosion on road and railways embankments in the Canyoles river watershed, Eastern Spain, Hydrology and Earth System Sciences, Discussions, 12, 12947-12985.doi:10.5194/hessd-12-12947-2015 Pereira, P., Oliva, M., Misiune, I. (2016) Spatial interpolation of precipitation indexes in Sierra Nevada (Spain): comparing the performance of some interpolation methods, Theoretical and Applied Climatology (in press), doi:10.1007/s00704-015-1606-8

  12. Hydrological and depositional processes associated with recent glacier recession in Yanamarey catchment, Cordillera Blanca (Peru).

    PubMed

    López-Moreno, J I; Valero-Garcés, B; Mark, B; Condom, T; Revuelto, J; Azorín-Molina, C; Bazo, J; Frugone, M; Vicente-Serrano, S M; Alejo-Cochachin, J

    2017-02-01

    In this study, we investigate changes in the glaciated surface and the formation of lakes in the headwater of the Querococha watershed in Cordillera Blanca (Peru) using 24 Landsat images from 1975 to 2014. Information of glacier retreat was integrated with available climate data, the first survey of recent depositional dynamics in proglacial Yanamarey Lake (4600m a.s.l.), and a relatively short hydrological record (2002-2014) at the outlet of Yanamarey Lake. A statistically significant temperature warming (0.21°C decade -1 for mean annual temperature) has been detected in the region, and it caused a reduction of the glacierized area since 1975 from 3.5 to 1.4km -2 . New small lakes formed in the deglaciated areas, increasing the flooded area from1.8ha in 1976 to 2.8ha in 2014. A positive correlation between annual rates of glacier recession and runoff was found. Sediment cores revealed a high sedimentation rate (>1cmyr -1 ) and two contrasted facies, suggesting a shift toward a reduction of meltwater inputs and higher hydrological variability likely due to an increasing role of precipitation on runoff during the last decades. Despite the age control uncertainties, the main transition likely occurred around 1998-2000, correlating with the end of the phase with maximum warming rates and glacier retreat during the 1980s and 1990s, and the slowing down of expansion of surface lake-covered surface. With this hydrological - paleolimnological approach we have documented the association between recent climate variability and glacier recession and the rapid transfer of hydroclimate signal to depositional and geochemical processes in high elevation Andean environments. This, study also alerts about water quality risks as proglacial lakes act as secondary reservoirs that trap trace and minor elements in high altitude basins. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Titan's lakes and Mare observed by the Visual and Infrared Mapping Spectrometer

    NASA Astrophysics Data System (ADS)

    Brown, R. H.; Soderblom, L. A.; Sotin, C.; Barnes, J. W.; Hayes, A. G.; Lawrence, K. J.; Le Mouelic, S.; Rodriguez, S.; Soderblom, J. M.; Baines, K. H.; Buratti, B. J.; Clark, R. N.; Jaumann, R.; Nicholson, P. D.; Stephan, K.

    2012-04-01

    Titan is the only place, besides Earth, that holds stable liquid bodies at its surface. The large Kraken Mare, first seen by ISS [1], was then observed by the radar instrument that discovered a large number of small lakes as well as two other Mare [2]. The liquid nature of these radar-dark features was later confirmed by the specular reflection observed by the Visual and Infrared Mapping Spectrometer (VIMS) over Kraken Mare [3] and by the very low albedo at 5-micron over Ontario Lacus [4]. The three largest lakes are called Mare and are all located in the North Pole area. It is remarkable that most of these lakes have been observed on the North Pole with only one large lake, Ontario lacus, located in the South Pole area. This observation suggests the influence of orbital parameters on the meteorology and the occurrence of rainfalls to refill the depressions [5]. Ethane was detected by the VIMS instrument as one component of Ontario lacus [4]. These lakes and Mare play a key role in Titan's meteorology as demonstrated by recent global circulation models [6]. Determining the composition and the evolution of those lakes has become a primary science objective of the Cassini extended mission. Since Titan entered northern spring in August 2009, the North Pole has been illuminated allowing observations at optical wavelengths. On June 5, 2010 the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft observed the northern pole area with a pixel size from 3 to 7 km. These observations demonstrate that little of the solar flux at 5-micron is scattered by the atmosphere, which allowed us to build a mosaic covering an area of more than 500,000 km2 that overlaps and complements observations made by the Synthetic Aperture Radar (SAR) in 2007. We find that there is an excellent correlation between the shape of the radar dark area, known as Ligeia Mare and the VIMS 5-micron dark unit. Matching most of the radar shoreline, the 2010 VIMS observations suggest that the 125,000-km2 surface area of Ligeia Mare measured by RADAR in 2007 has not significantly changed [7]. The analysis of the 2-micron spectral window confirms the presence of ethane [8]. Because its saturation vapor pressure is several orders of magnitude smaller than that of methane, liquid ethane is expected to be very stable at Titan's surface conditions, which could explain the stability of the shorelines if ethane is the major compound of the lakes. VIMS observations of Ontario Lacus are planned in 2012 before it disappears in the polar night. Several observations of the northern lakes are planned in 2012 as well as observations of the Mare later in the mission. This work has been performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Government sponsorship acknowledged.

  14. Carbon Cycling of Lake Kivu (East Africa): Net Autotrophy in the Epilimnion and Emission of CO2 to the Atmosphere Sustained by Geogenic Inputs

    PubMed Central

    Borges, Alberto V.; Morana, Cédric; Bouillon, Steven; Servais, Pierre; Descy, Jean-Pierre; Darchambeau, François

    2014-01-01

    We report organic and inorganic carbon distributions and fluxes in a large (>2000 km2) oligotrophic, tropical lake (Lake Kivu, East Africa), acquired during four field surveys, that captured the seasonal variations (March 2007–mid rainy season, September 2007–late dry season, June 2008–early dry season, and April 2009–late rainy season). The partial pressure of CO2 (pCO2) in surface waters of the main basin of Lake Kivu showed modest spatial (coefficient of variation between 3% and 6%), and seasonal variations with an amplitude of 163 ppm (between 579±23 ppm on average in March 2007 and 742±28 ppm on average in September 2007). The most prominent spatial feature of the pCO2 distribution was the very high pCO2 values in Kabuno Bay (a small sub-basin with little connection to the main lake) ranging between 11213 ppm and 14213 ppm (between 18 and 26 times higher than in the main basin). Surface waters of the main basin of Lake Kivu were a net source of CO2 to the atmosphere at an average rate of 10.8 mmol m−2 d−1, which is lower than the global average reported for freshwater, saline, and volcanic lakes. In Kabuno Bay, the CO2 emission to the atmosphere was on average 500.7 mmol m−2 d−1 (∼46 times higher than in the main basin). Based on whole-lake mass balance of dissolved inorganic carbon (DIC) bulk concentrations and of its stable carbon isotope composition, we show that the epilimnion of Lake Kivu was net autotrophic. This is due to the modest river inputs of organic carbon owing to the small ratio of catchment area to lake surface area (2.15). The carbon budget implies that the CO2 emission to the atmosphere must be sustained by DIC inputs of geogenic origin from deep geothermal springs. PMID:25314144

  15. Hydrology, water quality, and response to changes in phosphorus loading of Minocqua and Kawaguesaga Lakes, Oneida County, Wisconsin, with special emphasis on effects of urbanization

    USGS Publications Warehouse

    Garn, Herbert S.; Robertson, Dale M.; Rose, William J.; Saad, David A.

    2010-01-01

    Minocqua and Kawaguesaga Lakes are 1,318- and 690-acre interconnected lakes in the popular recreation area of north-central Wisconsin. The lakes are the lower end of a complex chain of lakes in Oneida and Vilas Counties, Wis. There is concern that increased stormwater runoff from rapidly growing residential/commercial developments and impervious surfaces from the urbanized areas of the Town of Minocqua and Woodruff, as well as increased effluent from septic systems around their heavily developed shoreline has increased nutrient loading to the lakes. Maintaining the quality of the lakes to sustain the tourist-based economy of the towns and the area was a concern raised by the Minocqua/Kawaguesaga Lakes Protection Association. Following several small studies, a detailed study during 2006 and 2007 was done by the U.S. Geological Survey, in cooperation with the Minocqua/Kawaguesaga Lakes Protection Association through the Town of Minocqua to describe the hydrology and water quality of the lakes, quantify the sources of phosphorus including those associated with urban development and to better understand the present and future effects of phosphorus loading on the water quality of the lakes. The water quality of Minocqua and Kawaguesaga Lakes appears to have improved since 1963, when a new sewage-treatment plant was constructed and its discharge was bypassed around the lakes, resulting in a decrease in phosphorus loading to the lakes. Since the mid-1980s, the water quality of the lakes has changed little in response to fluctuations in phosphorus loading from the watershed. From 1986 to 2009, summer average concentrations of near-surface total phosphorus in the main East Basin of Minocqua Lake fluctuated from 0.009 mg/L to 0.027 mg/L but generally remained less than 0.022 mg/L, indicating that the lake is mesotrophic. Phosphorus concentrations from 1988 through 1996, however, were lower than the long-term average, possibly the result of an extended drought in the area. Water-quality data for Kawaguesaga Lake had a similar pattern to that of Minocqua Lake. Summer average chlorophyll a concentrations and Secchi depths also indicate that the lakes generally are mesotrophic but occasionally borderline eutrophic, with no long-term trends. During the study, major water and phosphorus sources were measured directly, and minor sources were estimated to construct detailed water and phosphorus budgets for the lakes for monitoring years (MY) 2006 and 2007. During these years, the Minocqua Thoroughfare contributed about 38 percent of the total inflow to the lakes, and Tomahawk Thoroughfare contributed 34 percent; near-lake inflow, precipitation, and groundwater contributed about 1, 16, and 11 percent of the total inflow, respectively. Water leaves the lakes primarily through the Tomahawk River outlet (83 percent) or by evaporation (14 percent), with minor outflow to groundwater. Total input of phosphorus to both lakes was about 3,440 pounds in MY 2006 and 2,200 pounds in MY 2007. The largest sources of phosphorus entering the lakes were the Minocqua and Tomahawk Thoroughfares, which delivered about 39 and 26 percent of the total, respectively. The near-lake drainage area, containing most of the urban and residential developments, disproportionately accounted for about 12 percent of the total phosphorus input but only about 1 percent of the total water input (estimated with WinSLAMM). The next largest contributions were from septic systems and precipitation, each contributing about 10 percent, whereas groundwater delivered about 4 percent of the total phosphorus input. Empirical lake water-quality models within BATHTUB were used to simulate the response of Minocqua and Kawaguesaga Lakes to 19 phosphorus-loading scenarios. These scenarios included the current base years (2006?07) for which lake water quality and loading were known, nine general increases or decreases in phosphorus loading from controllable external sources (inputs from the tributa

  16. Terrestrial laser scanning observations of geomorphic changes and varying lava lake levels at Erebus volcano, Antarctica

    NASA Astrophysics Data System (ADS)

    Jones, Laura K.; Kyle, Philip R.; Oppenheimer, Clive; Frechette, Jedediah D.; Okal, Marianne H.

    2015-03-01

    A Terrestrial Laser Scanning (TLS) instrument was used to image the topography of the Main Crater at Erebus volcano each December in 2008, 2009, and 2010. Our high-spatial resolution TLS scans provide unique insights into annual and decadal scale geomorphic evolution of the summit area when integrated with comparable data collected by an airborne instrument in 2001. We observe both a pattern of subsidence within the Inner Crater of the volcano and an ~ 3 m per-year drop in the lava lake level over the same time period that are suggestive of decreasing overpressure in an underlying magma reservoir. We also scanned the active phonolite lava lake hosted within the Inner Crater, and recorded rapid cyclic fluctuations in the level of the lake. These were sporadically interrupted by minor explosions by bursting gas bubbles at the lake surface. The TLS data permit calculation of lake level rise and fall speeds and associated rates of volumetric change within the lake. These new observations, when considered with prior determinations of rates of lake surface motion and gas output, are indicative of unsteady magma flow in the conduit and its associated variability in gas volume fraction.

  17. PeRL: a circum-Arctic Permafrost Region Pond and Lake database

    NASA Astrophysics Data System (ADS)

    Muster, Sina; Roth, Kurt; Langer, Moritz; Lange, Stephan; Cresto Aleina, Fabio; Bartsch, Annett; Morgenstern, Anne; Grosse, Guido; Jones, Benjamin; Sannel, A. Britta K.; Sjöberg, Ylva; Günther, Frank; Andresen, Christian; Veremeeva, Alexandra; Lindgren, Prajna R.; Bouchard, Frédéric; Lara, Mark J.; Fortier, Daniel; Charbonneau, Simon; Virtanen, Tarmo A.; Hugelius, Gustaf; Palmtag, Juri; Siewert, Matthias B.; Riley, William J.; Koven, Charles D.; Boike, Julia

    2017-06-01

    Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002-2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( < 300 m a.s.l.) land surface area. PeRL waterbodies with sizes of 1. 0 × 106 m2 down to 1. 0 × 102 m2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1. 0 × 10 to 9. 4 × 101 km-2. Ponds are the dominant waterbody type by number in all landscapes representing 45-99 % of the total waterbody number. The implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands. Waterbody maps, study area boundaries, and maps of regional permafrost landscapes including detailed metadata are available at https://doi.pangaea.de/10.1594/PANGAEA.868349.

  18. Chemical composition of natural waters of contaminated area: The case for the Imandra Lake catchment (the Kola Peninsula)

    NASA Astrophysics Data System (ADS)

    Evtyugina, Z. A.; Guseva, N. V.; Kopylova, J. G.; A, Vorobeva D.

    2016-03-01

    The study of the current chemical composition of natural waters in the eastern and western parts of the Imandra Lake catchment was performed using ion chromatography, potentiometry and inductively coupled plasma mass spectrometry. It was found that the content of trace elements in the surface water is considerably higher than that in the groundwater. The nickel and copper concentrations exceed the background levels over 19 and 2 times respectively in groundwater, and 175 and 61 times in the surface waters. These data show that the Severonikel influences negatively air and surface water.

  19. HCMM hydrological analysis in Utah

    NASA Technical Reports Server (NTRS)

    Miller, A. W. (Principal Investigator)

    1982-01-01

    The feasibility of applying a linear model to HCMM data in hopes of obtaining an accurate linear correlation was investigated. The relationship among HCMM sensed data surface temperature and red reflectivity on Utah Lake and water quality factors including algae concentrations, algae type, and nutrient and turbidity concentrations was established and evaluated. Correlation (composite) images of day infrared and reflectance imagery were assessed to determine if remote sensing offers the capability of using masses of accurate and comprehensive data in calculating evaporation. The effects of algae on temperature and evaporation were studied and the possibility of using satellite thermal data to locate areas within Utah Lake where significant thermal sources exist and areas of near surface groundwater was examined.

  20. Major correlates of mercury in small fish and common loons (Gavia immer) across four large study areas in Canada.

    PubMed

    Scheuhammer, A M; Lord, S I; Wayland, M; Burgess, N M; Champoux, L; Elliott, J E

    2016-03-01

    We investigated mercury (Hg) concentrations in small fish (mainly yellow perch, Perca flavescens; ∼60% of fish collected) and in blood of common loons (Gavia immer) that prey upon them during the breeding season on lakes in 4 large, widely separated study areas in Canada (>13 lakes per study area; total number of lakes = 93). Although surface sediments from lakes near a base metal smelter in Flin Flon, Manitoba had the highest Hg concentrations, perch and other small fish and blood of common loon chicks sampled from these same lakes had low Hg concentrations similar to those from uncontaminated reference lakes. Multiple regression modeling with AIC analysis indicated that lake pH was by far the most important single factor influencing perch Hg concentrations in lakes across the four study areas (R(2) = 0.29). The best model was a three-variable model (pH + alkalinity + sediment Se; Wi = 0.61, R(2) = 0.85). A single-variable model (fish Hg) best explained among-lake variability in loon chick blood Hg (Wi = 0.17; R(2) = 0.53). From a toxicological risk perspective, all lakes posing a potential Hg health risk for perch and possibly other small pelagic fish species (where mean fish muscle Hg concentrations exceeded 2.4 μg/g dry wt.), and for breeding common loons (where mean fish muscle Hg concentrations exceeded 0.8 μg/g dry wt., and loon chick blood Hg exceeded 1.4 μg/g dry wt.) had pH < 6.7 and were located in eastern Canada. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  1. Large Eddy Simulation of complex sidearms subject to solar radiation and surface cooling.

    PubMed

    Dittko, Karl A; Kirkpatrick, Michael P; Armfield, Steven W

    2013-09-15

    Large Eddy Simulation (LES) is used to model two lake sidearms subject to heating from solar radiation and cooling from a surface flux. The sidearms are part of Lake Audrey, NJ, USA and Lake Alexandrina, SA, Australia. The simulation domains are created using bathymetry data and the boundary is modelled with an Immersed Boundary Method. We investigate the cooling and heating phases with separate quasi-steady state simulations. Differential heating occurs in the cavity due to the changing depth. The resulting temperature gradients drive lateral flows. These flows are the dominant transport process in the absence of wind. Study in this area is important in water quality management as the lateral circulation can carry particles and various pollutants, transporting them to and mixing them with the main lake body. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Groundwater and surface water interaction in flow-through gravel pit lakes.

    NASA Astrophysics Data System (ADS)

    Nella Mollema, Pauline; Antonellini, Marco

    2015-04-01

    Gravel pits are excavated in aquifers to fulfill the need for construction materials. Flow-through lakes form when the gravel pits are below the water table and fill with groundwater. In certain areas there are more than 60 of these lakes close together and their presence changes the drainage patterns and water- and hydrochemical budgets of a watershed. In flow-through gravel pit lakes, groundwater mixes with surface water and interacts with the atmosphere; outflow occurs only via groundwater. The lifespan of gravel pit lakes may be up to thousands of years as their depth to surface ratio is typically large and sedimentation rates are low. We have studied two gravel pit lake systems, a fluvial freshwater system in the Netherlands and a coastal brackish lake system in Italy. One Dutch gravel pit lake studied in detail is in part artificially replenished with Meuse River water for drinking water production that occurs downstream of the lake by water pumps. The Italian gravel pit lakes are fed by brackish groundwater that is a mix of freshwater from precipitation, Apennine Rivers and brackish (Holocene) Adriatic Sea water. Here, the drainage system of the low lying land enhances groundwater flow into the lake. Surface water evaporation is larger in temperate and Mediterranean climates than the actual evapotranspiration of pre-existing grassland and forests. The lakes, therefore, cause a loss of freshwater. The creation of water surfaces allows algae and other flora and fauna to develop. In general, water becomes gradually enriched in certain chemical constituents on its way through the hydrological cycle, especially as groundwater due to water-rock interactions. When groundwater ex-filtrates into gravel pit lakes, the natural flow of solutes towards the sea is interrupted. Hydrochemical analysis of ground- and surface waters, as well as chemical analysis of lake bottom sediments and stable H and O isotope data, show that gravel pit lake water is characterized (among others) by a higher pH, O2 and alkalinity and lower dissolved metal and certain trace concentrations than natural lakes and groundwater. In both settings, groundwater rich in dissolved elements (e.g. Al, As, Fe, Mn, Ni and PO43) flows into the gravel pit lakes where the pH and DO are high, which enhances the (co)precipitation of Fe, Mn and Al oxides that include trace elements. Metal concentrations in the Dutch lake's bottom sediments have increased over a 10 year period. Redox reactions caused by water table lowering and farmland fertilization upstream from the lake explain the metals mobilization and subsequent transport with groundwater towards the lakes. The gravel pit lakes, especially if there are many close together, influence so the cycle of water metals, nutrients as well as other trace elements of a watershed by incorporating them into biomass and bottom sediments or creating an environment where they can remain in concentrated solution.

  3. Derivation and Validation of Supraglacial Lake Volumes on the Greenland Ice Sheet from High-Resolution Satellite Imagery

    NASA Technical Reports Server (NTRS)

    Moussavi, Mahsa S.; Abdalati, Waleed; Pope, Allen; Scambos, Ted; Tedesco, Marco; MacFerrin, Michael; Grigsby, Shane

    2016-01-01

    Supraglacial meltwater lakes on the western Greenland Ice Sheet (GrIS) are critical components of its surface hydrology and surface mass balance, and they also affect its ice dynamics. Estimates of lake volume, however, are limited by the availability of in situ measurements of water depth,which in turn also limits the assessment of remotely sensed lake depths. Given the logistical difficulty of collecting physical bathymetric measurements, methods relying upon in situ data are generally restricted to small areas and thus their application to largescale studies is difficult to validate. Here, we produce and validate spaceborne estimates of supraglacial lake volumes across a relatively large area (1250 km(exp 2) of west Greenland's ablation region using data acquired by the WorldView-2 (WV-2) sensor, making use of both its stereo-imaging capability and its meter-scale resolution. We employ spectrally-derived depth retrieval models, which are either based on absolute reflectance (single-channel model) or a ratio of spectral reflectances in two bands (dual-channel model). These models are calibrated by usingWV-2multispectral imagery acquired early in the melt season and depth measurements from a high resolutionWV-2 DEM over the same lake basins when devoid of water. The calibrated models are then validated with different lakes in the area, for which we determined depths. Lake depth estimates based on measurements recorded in WV-2's blue (450-510 nm), green (510-580 nm), and red (630-690 nm) bands and dual-channel modes (blue/green, blue/red, and green/red band combinations) had near-zero bias, an average root-mean-squared deviation of 0.4 m (relative to post-drainage DEMs), and an average volumetric error of b1%. The approach outlined in this study - image-based calibration of depth-retrieval models - significantly improves spaceborne supraglacial bathymetry retrievals, which are completely independent from in situ measurements.

  4. Spatial Evaluation of Heavy Metals Concentrations in the Surface Sediment of Taihu Lake.

    PubMed

    Niu, Yong; Jiao, Wei; Yu, Hui; Niu, Yuan; Pang, Yong; Xu, Xiangyang; Guo, Xiaochun

    2015-11-27

    With regard to the size of China's freshwater lakes, Taihu Lake ranks third and it plays an important role in the supply of drinking water, flood prevention, farming and navigation, as well as in the travelling industry. The problem of environmental pollution has attracted widespread attention in recent years. In order to understand the levels, distribution and sources of heavy metals in sediments of Taihu Lake, random selection was carried out to obtain 59 samples of surface sediment from the entire lake and study the concentrations of Pb, Cd, Cu, Zn, Cr and Ni. Toxic units were also calculated to normalize the toxicities caused by various heavy metals. As a result, Cd and Cu in sediment were considered lower than the effect range low (ERL) at all regions where samples were gathered, while Pb and Ni were categorized into ERL-effect range median (ERM) at over 22% of the regions where samples were obtained. Nevertheless, all average concentrations of the samples were below the level of potential effect. According to the findings of this research, significant spatial heterogeneity existed in the above heavy metals. In conclusion, the distribution areas of heavy metals with higher concentrations were mainly the north bays, namely Zhushan Bay, Meiliang Bay as well as Gonghu Bay. The distribution areas of Cu, Zn, Cr and Ni with higher concentration also included the lake's central region, whereas the uniform distribution areas of those with lower concentrations were the lake's southeast region. In addition, it was most probable that the spatial distribution of heavy metals was determined by river inputs, whereas atmospheric precipitation caused by urban and traffic contamination also exerted considerable effects on the higher concentrations of Pb and Cd. Through evaluating the total amount of toxic units (ΣTU), it was found that higher toxicity existed primarily in the north bays and central region of the lake. If the heavy metals were sorted by the reduction of mean heavy metal toxic units in Taihu Lake in descending order, it would be Pb, Cr, Ni, Cd, Zn and Cu. Generally speaking, these result of analyses are conducive to alleviating the contamination of heavy metals in Taihu Lake.

  5. Methane distribution and transportation in Lake Chaohu: a shallow eutrophic lake in Eastern China

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Shen, Q.

    2016-12-01

    Global warming and eutrophication are two world widely concerned environmental problems. Methane is the second important greenhouse gas, and lake has been proven as a quite important natural source of methane emission. More methane may emit from eutrophic lake due to the higher organic matter deposition in the lake sediment. Lake Chaohu is a large and shallow eutrophic lake in eastern China (N31°25' 31°43', E117°16' 117°05'), with an area of 770 km2 and a mean depth of 2.7 m. To examine methane distribution and transportation in this eutrophic lake, field study across different seasons was carried out with 20 study sites in the lake. Samples from the different water and sediment depth was collected using headspace bottle, and methane content was measured by gas chromatography using a flame ionization detector. The potential methane production in the sediment was examined by an indoor incubation experiment. Methane flux from sediment to the overlying water was calculated by Fick's law, and methane emission from surface to the air was calculated at the same time. The results indicates that more methane accumulated in the water of northwestern bay in this lake, and higher methane release rates was also found at this area. Methane increases gradually with depth in the top 10 cm in sediment cores, then it almost keeps at constant state in the deeper sediment. In the sediment from northwestern bay, more methane content and the higher potential methane production was found compared to the sediment from the east area of this lake.

  6. Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

    PubMed

    Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

    2016-06-01

    Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. A Composite Depth Scale for Sediments from Crevice Lake, Montana

    USGS Publications Warehouse

    Rosenbaum, J.G.; Skipp, G.; Honke, J.; Chapman, C.

    2010-01-01

    As part of a study to derive records of past environmental change from lake sediments in the western United States, a set of cores was collected from Crevice Lake, Montana, in late February and early March 2001. Crevice Lake (latitude 45.000N, longitude 110.578W, elevation 1,713 meters) lies adjacent to the Yellowstone River at the north edge of Yellowstone National Park. The lake is more than 31 meters deep and has a surface area of 7.76 hectares. The combination of small surface area and significant depth promote anoxic bottom-water conditions that preserve annual laminations (varves) in the sediment. Three types of cores were collected through the ice. The uppermost sediments were obtained in freeze cores that preserved the sediment water interface. Two sites were cored with a 5-centimeter diameter corer. Five cores were taken with a 2-meter-long percussion piston corer. The percussion core uses a plastic core liner with an inside diameter of 9 centimeters. Coring was done at two sites. Because of the relatively large diameter of the percussion cores, samples from these cores were used for a variety of analyses including pollen, charcoal, diatoms, stable isotopes, organic and inorganic carbon, elemental analyses, and magnetic properties.

  8. VERTICAL DIFFUSION IN SMALL STRATIFIED LAKES: DATA AND ERROR ANALYSIS

    EPA Science Inventory

    Water temperature profiles were measured at 2-min intervals in a stratified temperate lake with a surface area of 0.06 km2 and a aximum depth of 10 m from May 7 to August 9, 1989. he data were used to calculate the vertical eddy diffusion coefficient K2 in the hypolimnion. he dep...

  9. 77 FR 790 - Grant Lake Hydroelectric Project; Notice of Preliminary Permit Application Accepted for Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13212-002] Grant Lake.... The proposed project would consist of: (1) Either (a) a 2-foot-high by 120-foot-long, concrete gravity... project reservoir, with a total storage capacity of 15,900 acre-feet and a water surface area of 1,790...

  10. Recent evolution of glacial lakes in the Eastern Himalayas: the case-study of Mt. Everest (Nepal)

    NASA Astrophysics Data System (ADS)

    Salerno, Franco; D'Agata, Carlo; Diolaiuti, Guglielmina; Smiraglia, Claudio; Viviano, Gaetano; Tartari, Gianni

    2010-05-01

    In this contribution we analyze the glacier and lakes surface variations since the end of the 1950s until 2008 (around 50 years) through hystorical maps and remote sensing images. The Sagarmatha National Park (SNP), Eastern Hymalaian range (Nepal) covers an area of 1141km2, ranging from 2845 m to 8848 m (Mt Everest). Nearly all (28 out of a total of 29 in SNP) are ‘black glaciers', known also as D-type or debris-covered. Overall, SNP experienced a small net reduction in glacier cover of 19.6 km2 (4.9%) from 403.9 km2 at the end of the ‘50s to 384.6 km2 at the start of the ‘90s. As regards lakes surface variations, SNP experienced a very large net increasing in lake surface cover of 1.6 km2 (26%) from 6.0 km2 at the end of the ‘50s to 7.6 km2 in 2008. Moreover the number of lakes is enormously increased (by 36%, from 124 to 169). The new lakes have appeared at higher elevations (42 m higher than the lakes of 50's) probably following the glaciers retreat. As previously documented in bibliography, the Proglacial lakes (Moraine-dammed and in contact with the glacier front) is the typology of glacial lakes more effected by the climate change. These lakes are susceptible to Glacial Lake Outburst Floods (GLOFs) with the potential of releasing million cubic meters of water in a few hours causing catastrophic flooding up. We conclude this contribution pointing out the emerged scientific questions to address future research activities.

  11. Classifying and monitoring water quality by use of satellite imagery

    NASA Technical Reports Server (NTRS)

    Scherz, J. P.; Crane, D. R.; Rogers, R. H.

    1975-01-01

    A technique in which LANDSAT measurements from very clear lakes are subtracted from measurements from other lakes in order to remove atmospheric and surface noise effects to obtain a residual signal dependent only on the material suspended in the water is described. This residual signal is used by the Multispectral Data Analysis System as a basis for producing color categorized imagery showing lakes by type and concentration of suspended material. Several hundred lakes in the Madison and Spooner, Wisconsin area were categorized for tannin or non-tannin waters and for the degree of algae, silt, weeds, and bottom effects.

  12. Great Lakes

    USGS Publications Warehouse

    Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

    1998-01-01

    The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human population.The wild plants and animals and the natural systems that support them in the Great Lakes region are valuable resources of considerable local, regional, and national interest. They are also, in part, transboundary resources that we share with our Canadian neighbors to the north. The way these resources are changing over time is inadequately known and is a cause for concern for resource users and for those charged with managing and protecting these unique and valuable resources. This chapter describes the wild plants and animals and the systems that support them in the Great Lakes region; addresses their condition; and points out the gaps in our knowledge about them that, if filled, would aid in their conservation and appropriate use.

  13. Spatial and temporal distribution and sources of polycyclic aromatic hydrocarbons in sediments of Taihu Lake, eastern China.

    PubMed

    Tang, Zhi; Guo, Jianyang; Liao, Haiqing; Zhao, Xiaoli; Wu, Fengchang; Zhu, Yuanrong; Zhang, Liang; Giesy, John P

    2015-04-01

    Spatial and temporal distributions of concentrations of polycyclic aromatic hydrocarbons (PAHs) in surface sediments and dated sediment core from Taihu Lake in eastern China were determined. The sum of concentrations of PAHs (sum of total 16 USEPA priority PAH (∑PAHs)) of the entire Taihu Lake ranged from 2.9 × 10(2) to 8.4 × 10(2) ng/g dry mass (dm). Concentrations of ∑PAHs in surface sediments near more urbanized regions of the lake shore were greater than those in areas more remote from the urban centers. Temporal trends in concentrations of ∑PAHs ranged from 5.1 × 10(2) to 1.5 × 10(3) ng/g dm, increasing from deeper layers to surface sediments with some fluctuations, especially in the past three decades after the inception of China's Reform and Opening Up Policy, in which China's economy and urbanization underwent rapid development. Forensic analysis of surface sediments indicates that PAHs originated primarily from combustion of grass/wood/coal except for the special function water area, which was most likely influenced by petroleum products of traveling vessels. Vertical profiles of relative concentrations of PAHs suggested that the contribution of lesser-molecular-weight PAHs was gradually decreasing, while due to the heavier consumption of petroleum products, the proportion of greater-molecular-weight PAHs was increasing. When assessed by use of the rather conservative, apparent effect threshold method, concentrations of ∑PAHs in sediments from most locations in Taihu Lake are predicted to pose little risk of harm to benthic invertebrates.

  14. Water-quality and lake-stage data for Wisconsin lakes, water year 2005

    USGS Publications Warehouse

    Rose, W.J.; Garn, H.S.; Goddard, G.L.; Marsh, S.B.; Olson, D.L.; Robertson, Dale M.

    2006-01-01

    The U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. The purpose of this report is to provide information about the chemical and physical charac-teristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measure-ments of in-lake water quality and lake stage. Time series graphs of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive infor-mation for each lake includes: location of the lake, area of the lake's watershed, period for which data are available, revisions to previously published records, and pertinent remarks.

  15. Variation laws and release characteristics of phosphorus on surface sediment of Dongting Lake.

    PubMed

    Zhu, Guangrui; Yang, Ying

    2018-05-01

    The variation trend and growth rate of P were analyzed by the concentration of the phosphorus fraction on surface sediment of Dongting Lake from 2012 to 2016, to reveal the cumulative effect of P in the actual environment. Meanwhile, the adsorption kinetics and adsorption isotherm were employed to examine the P-release possibility of sediment, which predicts the yearly released sediment phosphorus in Dongting Lake. The actual growth rate of TP (Total Phosphorus) is 53 mg·(kg·year) -1 in East Dongting Lake, 39 mg·(kg·year) -1 in South Dongting Lake, and 29 mg·(kg·year) -1 in West Dongting Lake, while the sum of the phosphorus fraction growth rates has little difference from the rate of TP in sediments of the three areas of Dongting Lake. Furthermore, the Elovich model and the Langmuir crossover-type equations are established to present the adsorption characteristic of sediment in Dongting Lake; the result shows that the sediments play a source role for phosphorus in East and South Dongting Lake from zero equilibrium phosphorus concentration (EPC 0 ) in the present situation, but an adsorption effect on TP is shown in West Dongting Lake. When the conditions of environment change are ignored, the maximum P-sorption level in sediments of East Dongting Lake will reach in 2040 according to the actual growth rate of sediments, while that in West Dongting Lake and South Dongting Lake will be in 2046 and 2061, respectively.

  16. Recent and Late Holocene Alaskan Lake Changes Identified from Water Isotopes

    NASA Astrophysics Data System (ADS)

    Anderson, L.; Birks, S. J.; Rover, J.; Guldager, N.

    2014-12-01

    To identify the existence and cause of recent lake area changes in the Yukon Flats, a region of discontinuous permafrost in north central Alaska, we evaluate lake water isotope compositions with remotely sensed imagery and hydroclimatic parameters. Estimates of the ratio of water lost by evaporation to that gained by inflow (E/I) were derived from an isotope-based water balance model. The isotope labels are also used to identify the dominant sources for lakes such as rainfall and snowfall, groundwater, rivers, or thawed permafrost. These parameters are then used in conjunction with climatic data and remotely sensed imagery to identify the patterns and causes of recent lake area changes and for evaluation with lake sediment oxygen isotope records of late Holocene lake water isotope variations. Lake water isotope samples from 83 lakes were acquired in July, August or September between 2007 and 2010 by fixed wing aircraft. An additional set of smaller lakes (n = 33) was sampled by helicopter in September 2009. In July 2011 59 lakes were sampled on foot within five distinct 11.2-km2 areas. River water data used here are previously collected during the months of June through October between 2006 and 2008. Isotope compositions indicate that mixtures of precipitation, river water, and groundwater source ~95% of the studied lakes. The remaining minority are more dominantly sourced by snowmelt and/or permafrost thaw. Isotope-based water balance estimates indicate 58% of lakes lose more than half of inflow by evaporation. For 26% of the lakes studied, evaporative losses exceeded supply. Surface area trend analysis indicates that most lakes were near their maximum extent in the early 1980s during a relatively cool and wet period. Subsequent reductions can be explained by moisture deficits and greater evaporation. Comparison with late Holocene isotope values and trends indicates recent changes are within the range of late Holocene variability. The records indicate a drier and warmer than present climate prior to 4000 years ago, whereas it was wetter and cooler between 4000 and 2000 years ago. These findings indicate that attempts to project future high-latitude lake change will benefit from considering the effects of decade to multi-decadal scale hydroclimatic variations.

  17. Geology of Utah and Nevada by ERTS imagery

    NASA Technical Reports Server (NTRS)

    Jensen, M. L. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Two ancient watercourses have been observed on ERTS-1 imagery. These lie in the Waterpocket Fold area, north of the Marble Canyon section of the Colorado River, in Arizona and Utah. A third old watercourse of interest is an ancient canyon of the Colorado and is located on image no. 1156-17260. Image no. 1051-17414 contains some very useful information concerning the hydrology, sedimentology, and biology of Great Salt Lake and Bear Lake in Utah. In Great Salt Lake, there is a sharp line between the portion of the lake north of the railroad causeway and that south of the causeway. There is a marked difference in salinity across the causeway, and this is reflected in different algal species. On the same image, sediment plumes in Bear Lake clearly delineate the circulation pattern, and provide excellent indications of bottom contours over much of the area. Image no. 1051-17420 contains part of Great Salt Lake and all of Utah Lake. The latter displays a very interesting surface pattern which is probably due to an algal bloom which has been swirled into a spiral by the circulation of the lake.

  18. Lava lake activity at the summit of Kīlauea Volcano in 2016

    USGS Publications Warehouse

    Patrick, Matthew R.; Orr, Tim R.; Swanson, Donald A.; Elias, Tamar; Shiro, Brian

    2018-04-10

    The ongoing summit eruption at Kīlauea Volcano, Hawai‘i, began in March 2008 with the formation of the Overlook crater, within Halema‘uma‘u Crater. As of late 2016, the Overlook crater contained a large, persistently active lava lake (250 × 190 meters). The accessibility of the lake allows frequent direct observations, and a robust geophysical monitoring network closely tracks subtle changes at the summit. These conditions present one of the best opportunities worldwide for understanding persistent lava lake behavior and the geophysical signals associated with open-vent basaltic eruptions. In this report, we provide a descriptive and visual summary of lava lake activity during 2016, a year consisting of continuous lava lake activity. The lake surface was composed of large black crustal plates separated by narrow incandescent spreading zones. The dominant motion of the surface was normally from north to south, but spattering produced transient disruptions to this steady motion. Spattering in the lake was common, consisting of one or more sites on the lake margin. The Overlook crater was continuously modified by the deposition of spatter (often as a thin veneer) on the crater walls, with frequent collapses of this adhered lava into the lake. Larger collapses, involving lithic material from the crater walls, triggered several small explosive events that deposited bombs and lapilli around the Halema‘uma‘u Crater rim, but these did not threaten public areas. The lava lake level varied over several tens of meters, controlled primarily by changes in summit magma reservoir pressure (in part driven by magma supply rates) and secondarily by fluctuations in spattering and gas release from the lake (commonly involving gas pistoning). The lake emitted a persistent gas plume, normally averaging 1,000–8,000 metric tons per day (t/d) of sulfur dioxide (SO2), as well as a constant fallout of small juvenile and lithic particles, including Pele’s hair and tears. The gas emissions created volcanic air pollution (vog) that affected large areas of the Island of Hawai‘i. The summit eruption has been a major attraction for visitors in Hawai‘i Volcanoes National Park. During 2016, the rising lake levels allowed the lake and its spattering to be more consistently visible from public viewing areas, enhancing the visitor experience. The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) closely monitors the summit eruption and keeps emergency managers and the public informed of activity.

  19. The study of Lake Urmia desiccation: morphometry impress

    NASA Astrophysics Data System (ADS)

    Moradi, Ayoub; Rasouli, Ali Akbar; Roostaei, Shahram

    2017-04-01

    Located in northwestern Iran, the hypersaline Lake Urmia has started a serious uninterrupted desiccation since 1995. The lake has lost about eight meters of water level and about 75% of water surface area during past 20 years. In particular, the lake water volume decrement has been accelerated in recent years. The importance of the Lake Urmia for human life in northwestern Iran, and its destructive effects on a vast region if totally dry up, demands comprehensive studies of the lake level fluctuations mechanism. According to literature review, the water volume of the lake behaves sometimes differently from the water storage of the whole basin. Our time series analysis using Land Data Assimilation Systems also confirms those differences within last decades. In other hand, many studies addressed the lake desiccation to climatic changes and/or anthropogenic influences such as excessive dam constructions in the watershed during last decades. As water leaves the lake only through evaporation, the fluctuation of evaporation has a distinctive role in the lake level variations. Dramatic decreament in the lake extent indicates of a special morphometry. The lake's morphometry has made it vulnerable to temperature and salinity changes. It strongly controls the lake's water heat capacity and water density. And, it therefore controls the rate of evaporation from water surface. We study the role of lake's morphometry on the lake desiccation. Although, the global climatic change is known as the primary reason for current droughts in the Middle East generally, our preliminary results show that the lake's morphometry is the main cause for the accelerating of water volume lost in Lake Urmia. In particular, after 2007, lake's water temperature and density show significant variations. Water heat capacity and evaporation rate are consistent with information of lake's hypsometry.

  20. Resistivity profiling to locate an infiltration area and the possible recovery of the dried Andara lake (Picos de Europa National Park, Spain)

    NASA Astrophysics Data System (ADS)

    Gallastegui, Jorge; Olona, Javier; Farias, Pedro; González-Cortina, Juan Manuel; Fernández-Viejo, Gabriela; López, Carlos; Cadenas, Patricia

    2013-04-01

    The Ándara Lake constituted the third mass of water by extension (approximately 19000 m2) within the calcareous Picos de Europa Massif in NW Spain, but only a small pond remains today (about 1250 m2). The lake developed in a former glacial valley and its sudden draining occurred in the second decade of the 20th century, during the development of underground Pb-Zn mining, between 1889 and 1929, in the vicinity. Old mining maps show that there were shallow galleries active below the bottom of the ancient lake. The present study was requested by the Picos de Europa National Park Administration (Spanish Ministry of Environment) with the purpose of: i) localizing the areas of water infiltration and ii) establishing the cause of the draining, specially its possible relation with the mining activity in the surroundings. With this aim a geological study of the substrate of the lake was made, followed by a series of electrical resistivity profiles. Three resistivity parallel profiles were recorded along the axis of the dried lake on the 29th July. Each profile included 56 electrodes with 5 m spacing for a total profile length of 275 m. Data was recorded in both dipole-dipole and Schlumberger array configuration. The western profile had been recorded earlier in the summer (30th June) and was also repeated towards the end of the season (3rd September) in order to evaluate the evolution of the infiltrations. The results showed two areas of infiltration to the NE and SW of the present-day pond. Both of them cut across the underlying carboniferous limestone. However. the southwestern anomaly does not reach the surface and may be related with water flowing in karstic conduits in the limestone. The northeastern one reached the surface and the anomaly decreased as the pond dried during the summer allowing us to interpret it as the main area of infiltration. This area coincides with the intersection of two seams exploited both on the surface and by underground mining. This corroborates the relationship between the water disappearance and the mining activities, which is an indispensable condition for the National Park management to consider taking any future actions aimed to a possible recovery of the original water mass.

  1. Impact of a thermokarst lake on the soil hydrological properties in permafrost regions of the Qinghai-Tibet Plateau, China.

    PubMed

    Gao, Zeyong; Niu, Fujun; Wang, Yibo; Luo, Jing; Lin, Zhanju

    2017-01-01

    The formation of thermokarst lakes can degrade alpine meadow ecosystems through changes in soil water and heat properties, which might have an effect on the regional surface water and groundwater processes. In this study, a typical thermokarst lake was selected in the Qinghai-Tibet Plateau (QTP), and the ecological index (S L ) was used to divide the affected areas into extremely affected, severely affected, medium-affected, lightly affected, and non-affected areas, and soil hydrological properties, including saturated hydraulic conductivity and soil water-holding capacity, were investigated. The results showed that the formation of a thermokarst lake can lead to the degradation of alpine meadows, accompanied by a change in the soil physiochemical and hydrological properties. Specifically, the soil structure turned towards loose soil and the soil nutrients decreased from non-affected areas to severely affected areas, but the soil organic matter and available potassium increased slightly in the extremely affected areas. Soil saturated hydraulic conductivity showed a 1.7- to 4.1-fold increase in the lake-surrounding areas, and the highest value (401.9cmd -1 ) was detected in the severely affected area. Soil water-holding capacity decreased gradually during the transition from the non-affected areas to the severely affected areas, but it increased slightly in the extremely affected areas. The principal component analysis showed that the plant biomass was vital to the changes in soil hydrological properties. Thus, the vegetation might serve as a link between the thermokarst lake and soil hydrological properties. In this particular case, it was concluded that the thermokarst lake adversely affected the regional hydrological services in the alpine ecosystem. These results would be useful for describing appropriate hydraulic parameters with the purpose of modeling soil water transportation more accurately in the Qinghai-Tibet Plateau. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Integrating time-series and spatial surveys to assess annual, lake-wide emissions of carbon dioxide and methane from a eutrophic lake

    NASA Astrophysics Data System (ADS)

    Loken, L. C.; Crawford, J.; Schramm, P.; Stadler, P.; Stanley, E. H.

    2017-12-01

    Lakes are important regulators of global carbon cycling and conduits of greenhouse gases to the atmosphere; however, most efflux estimates for individual lakes are based on extrapolations from a limited number of locations. Within-lake variability in carbon dioxide (CO2) and methane (CH4) arises from differences in water sources, physical mixing, and biogeochemical transformations; all of which can vary at multiple temporal and spatial scales. We mapped surface water concentrations of CO2 and CH4 weekly across Lake Mendota (a 39.9 km2 eutrophic lake in Wisconsin, USA) spanning the majority of the 2016 ice-free season (249 days). Combining these maps with a spatially explicit gas transfer velocity (k) model, we estimated the diffusive exchange of both gases with the atmosphere taking into account both spatial and temporal heterogeneity. The cumulative efflux of CO2 (85.3 Mmol) and CH4 (9.47 Mmol) was positive, indicating that on the annual scale Lake Mendota was a net-source of both gases to the atmosphere. Although our model included variability in k, flux patterns reflected the patterns in gas concentrations. During the stratified period, CO2 was generally undersaturated throughout the pelagic zone due to high primary production and differed near river inlets and shorelines. The lake was routinely extremely supersaturated with CH4 with elevated concentrations in expansive littoral areas. During fall mixis, concentrations of both gases increased and became more variable across the lake surface, and their spatial arrangement changed reflecting hypolimentic mixing. In this system, samples collected from the lake center reasonably well-represented the lake-wide mean CO2 concentration, but they poorly represented CH4. While metabolic processes driving CO2 varied across the lake surface, pelagic phytoplankton contributed extensively to overall primary production, which acted at the lake-wide scale. Additionally Lake Mendota's high alkalinity may have masked the metabolic imprint on CO2 patterns. In contrast, heterogeneous CH4 transformations and transport lead to remarkable variation in CH4 across the lake surface that was dynamic through time. Thus, extrapolations from a limited number of locations or timepoints may not adequately describe lake-wide CH4 dynamics.

  3. 3D Thermal Stratification of Koycegiz Lake, Turkey.

    NASA Astrophysics Data System (ADS)

    Gurcan, Tugba; Kurtulus, Bedri; Avsar, Ozgur; Avsar, Ulas

    2017-04-01

    Water temperature in lakes, streams and coastal areas is an important indicator for several purposes (water quality, aquatic organism, land use, etc..). There are over a hundred lakes in Turkey. Most of them locates in the area known as the Lake District in southwestern Turkey. The Study area is located at the south and southwest part of Turkey in Muǧla region. The present study focuses on determining possible thermocline changes in Lake Koyceǧiz by in-situ measurements. The measurement were done by two snapshot campaign at July and August 2013. Using Mugla Sıtkı Kocman University geological engineering floating platform, temperature, specific conductance, salinity and depth values were measured with the YSI 6600 and Horiba U2 devices in surface and depth of Lake Köyceǧiz at specific grid. When the depth of the water and the coordinates were measured by GPS. Scattered data interpolation is used to perform interpolation on a scattered dataset that resides in 3D space. The 3D temperature color mesh grid were generated by using Delaunay triangulation and Natural neighbor interpolation methodology. At the end of the study a 3D conceptual lake temperature dynamics model was reconstructed using MATLAB functions. The results show that Koycegiz Lake is a meromictic lake and has a significance decrease of Temperature at 7m of depth.In this regard, we would like also to thank TUBITAK project (112Y137), French Embassy in Turkey and Sıtkı Kocman Foundation for their financial support.

  4. Microplastic Abundance and Composition in Western Lake Superior As Determined via Microscopy, Pyr-GC/MS, and FTIR.

    PubMed

    Hendrickson, Erik; Minor, Elizabeth C; Schreiner, Kathryn

    2018-02-20

    While plastic pollution in marine and freshwater systems is an active area of research, there is not yet an in-depth understanding of the distributions, chemical compositions, and fates of plastics in aquatic environments. In this study, the magnitude, distribution, and common polymers of microplastic pollution in surface waters in western Lake Superior are determined. Analytical methodology, including estimates of ambient contamination during sample collection and processing, are described and employed. Microscopy, pyrolysis-gas chromatography/mass spectrometry (Pyr-GC/MS), and Fourier transform infrared spectroscopy (FTIR) were used to quantify and identify microplastic particles. In surface waters, fibers were the most frequently observed morphology, and, based upon PyGC/MS analysis,  polyvinyl chloride was the most frequently observed polymer, followed by polypropylene and polyethylene. The most common polymer identified by FTIR was polyethylene. Despite the low human population in Lake Superior's watershed, microplastic particles (particularly fibers, fragments, and films) were identified in western-lake surface waters at levels comparable to average values reported in studies within Lake Michigan, the North Atlantic Ocean, and the South Pacific Ocean. This study provides insight into the magnitude of microplastic pollution in western Lake Superior, and describes in detail methodology to improve future microplastics studies in aquatic systems.

  5. Methane emission from high-latitude (>50N) lakes: Annual cycle of climatological emissions using satellite-derived lake-ice phenology and freeze-thaw dynamics

    NASA Astrophysics Data System (ADS)

    Matthews, E.; Romanski, J.; Du, J.; Watts, J. D.

    2017-12-01

    Lakes are increasingly recognized as potentially important contributors to global methane emissions despite occupying only a few percent of Earth's ice-free land surface. More than 40% of the global lake area lies in regions of amplified warming north of 50˚N. As with wetlands, lake emissions are sensitive to interannual fluctuations in, e.g., temperature and duration of thaw season. Several estimates of CH4emission from high-latitude lakes have been published but none relies on geospatial lake distributions and satellite-based duration and timing of thaw seasons. We report on a climatology of weekly, spatially-explicit methane emissions from high-latitude lakes. Lake break-up and freeze-up dates for lakes >50km^2 were determined from a lake-ice phenology data set derived from brightness temperature (Tb) observations of space-borne Advanced Microwave Scanning Radiometer (AMSR-E/2) sensors. The lake-ice conditions for smaller lakes were estimated using an Earth System Data Record for Land Surface Freeze-Thaw State derived from Tb observations of Scanning Multichannel Microwave Radiometer (SMMR), Special Sensor Microwave Imager (SSM/I), and SSM/I Sounder (SSMIS). Climatologies encompass 2002-2015 for lake ice phenology and 1979 to 2010 for the land surface freeze-thaw state. Climatologies encompass 2003-2014 for ice phenology and 1979 to 2010 for freeze-thaw dynamics. Length and timing of typical methane-emission periods, derived from the satellite data, were integrated with daily diffusive and ebulliative methane fluxes for lake types following the work of Wik et al. (Nature, 2016) to estimate a full annual cycle of emissions from lakes >50˚N. We explored several approaches to estimate the large bursts of emissions observed over short periods during lake-ice breakup immediately prior to full lake thaw since several studies suggest that a substantial fraction of total annual emissions may occur at this time. While highly uncertain, we plan to investigate whether the modest, short-lived but annual uptick in atmospheric methane concentrations in late winter/early spring may be associated with these bursts of methane from lakes.

  6. Three-dimensional simulation of gas and dust in Io's Pele plume

    NASA Astrophysics Data System (ADS)

    McDoniel, William J.; Goldstein, David B.; Varghese, Philip L.; Trafton, Laurence M.

    2015-09-01

    Io's giant Pele plume rises high above the moon's surface and produces a complex deposition pattern. We use the direct simulation Monte Carlo (DSMC) method to model the flow of SO2 gas and silicate ash from the surface of the lava lake, into the umbrella-shaped canopy of the plume, and eventually onto the surface where the flow leaves black "butterfly wings" surrounded by a large red ring. We show how the geometry of the lava lake, from which the gas is emitted, is responsible for significant asymmetry in the plume and for the shape of the red deposition ring by way of complicated gas-dynamic interactions between parts of the gas flow arising from different areas in the lava lake. We develop a model for gas flow in the immediate vicinity of the lava lake and use it to show that the behavior of ash particles of less than about 2 μm in diameter in the plume is insensitive to the details of how they are introduced into the flow because they are coupled to the gas at low altitudes. We simulate dust particles in the plume to show how particle size determines the distance from the lava lake at which particles deposit on the surface, and we use this dependence to find a size distribution of black dust particles in the plume that provides the best explanation for the observed black fans to the east and west of the lava lake. This best-fit particle size distribution suggests that there may be two distinct mechanisms of black dust creation at Pele, and when two log-normal distributions are fit to our results we obtain a mean particle diameter of 88 nm. We also propose a mechanism by which the condensible plume gas might overlay black dust in areas where black coloration is not observed and compare this to the observed overlaying of Pillanian dust by Pele's red ring.

  7. Bathymetric survey of Carroll Creek Tributary to Lake Tuscaloosa, Tuscaloosa County, Alabama, 2010

    USGS Publications Warehouse

    Lee, K.G.; Kimbrow, D.R.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the City of Tuscaloosa, conducted a bathymetric survey of Carroll Creek, on May 12-13, 2010. Carroll Creek is one of the major tributaries to Lake Tuscaloosa and contributes about 6 percent of the surface drainage area. A 3.5-mile reach of Carroll Creek was surveyed to prepare a current bathymetric map, determine storage capacities at specified water-surface elevations, and compare current conditions to historical cross sections. Bathymetric data were collected using a high-resolution interferometric mapping system consisting of a phase-differencing bathymetric sonar, navigation and motion-sensing system, and a data acquisition computer. To assess the accuracy of the interferometric mapping system and document depths in shallow areas of the study reach, an electronic total station was used to survey 22 cross sections spaced 50 feet apart. The data were combined and processed and a Triangulated Irregular Network (TIN) and contour map were generated. Cross sections were extracted from the TIN and compared with historical cross sections. Between 2004 and 2010, the area (cross section 1) at the confluence of Carroll Creek and the main run of LakeTuscaloosa showed little to no change in capacity area. Another area (cross section 2) showed a maximum change in elevation of 4 feet and an average change of 3 feet. At the water-surface elevation of 224 feet (National Geodetic Vertical Datum of 1929), the cross-sectional area has changed by 260 square feet for a total loss of 28 percent of cross-sectional storage area. The loss of area may be attributed to sedimentation in Carroll Creek and (or) the difference in accuracy between the two surveys.

  8. Evaluation of Water Quality Change of Brackish Lake in Snowy Cold Regions Accompanying Climate Change

    NASA Astrophysics Data System (ADS)

    Kudo, K.; Hasegawa, H.; Nakatsugawa, M.

    2017-12-01

    This study addresses evaluation of water quality change of brackish lake based on the estimation of hydrological quantities resulting from long-term hydrologic process accompanying climate change. For brackish lakes, such as Lake Abashiri in Eastern Hokkaido, there are concerns about water quality deterioration due to increases in water temperature and salinity. For estimating some hydrological quantities in the Abashiri River basin, including Lake Abashiri, we propose the following methods: 1) MRI-NHRCM20, a regional climate model based on the Representative Concentration Pathways adopted by IPCC AR5, 2) generalized extreme value distribution for correcting bias, 3) kriging adopted variogram for downscaling and 4) Long term Hydrologic Assessment model considering Snow process (LoHAS). In addition, we calculate the discharge from Abashiri River into Lake Abashiri by using estimated hydrological quantities and a tank model, and simulate impacts on water quality of Lake Abashiri due to climate change by setting necessary conditions, including the initial conditions of water temperature and water quality, the pollution load from the inflow rivers, the duration of ice cover and salt pale boundary. The result of the simulation of water quality indicates that climate change is expected to raise the water temperature of the lake surface by approximately 4°C and increase salinity of surface of the lake by approximately 4psu, also if salt pale boundary in the lake raises by approximately 2-m, the concentration of COD, T-N and T-P in the bottom of the lake might increase. The processes leading to these results are likely to be as follows: increased river water flows in along salt pale boundary in lake, causing dynamic flow of surface water; saline bottom water is entrained upward, where it mixes with surface water; and the shear force acting at salt pale boundary helps to increase the supply of salts from bottom saline water to the surface water. In the future, we will conduct similar simulations for a larger area that includes the mouth of Abashiri River. The accuracy of flow field simulation for Lake Abashiri will increase when calculations incorporate the effects of climate change on tide level, water temperature and salinity at the river mouth.

  9. Water Level Prediction of Lake Cascade Mahakam Using Adaptive Neural Network Backpropagation (ANNBP)

    NASA Astrophysics Data System (ADS)

    Mislan; Gaffar, A. F. O.; Haviluddin; Puspitasari, N.

    2018-04-01

    A natural hazard information and flood events are indispensable as a form of prevention and improvement. One of the causes is flooding in the areas around the lake. Therefore, forecasting the surface of Lake water level to anticipate flooding is required. The purpose of this paper is implemented computational intelligence method namely Adaptive Neural Network Backpropagation (ANNBP) to forecasting the Lake Cascade Mahakam. Based on experiment, performance of ANNBP indicated that Lake water level prediction have been accurate by using mean square error (MSE) and mean absolute percentage error (MAPE). In other words, computational intelligence method can produce good accuracy. A hybrid and optimization of computational intelligence are focus in the future work.

  10. Measurement of suspended solids in lakes and oceans using satellite remote sensing data

    NASA Technical Reports Server (NTRS)

    Sydor, M. (Principal Investigator)

    1980-01-01

    Using satellite remote sensing data to measure low concentrations of suspended solids in lakes and oceans requires careful evaluation of background signals from the atmosphere and the water surface. Typical background corrections for Lake Superior are presented and the spectral distribution of the residual radiance from three major categories of turbidity in the lake are determined. The results indicate that for large bodies of water, some general information on atmospheric scattering, water clarity, and the optical properties of suspended solids allows estimates of concentrations of suspended solids to within + or - 0.5 mg/L without using real time ground truth data. Under calibrated conditions the threshold detection level is 0.3 mg/L for the fine particulates dispersed throughout the lake and 1 mg/L for the highly light absorbing effluent from rivers. Comparisons of the minimum reflectance over the open lake areas with reflection from the highly absorbing tannin water from rivers provides a check on the clarity of the atmosphere and the excessive background scatter from the water surface.

  11. Geography of Alaska Lake Districts: Identification, Description, and Analysis of Lake-Rich Regions of a Diverse and Dynamic State

    USGS Publications Warehouse

    Arp, Christopher D.; Jones, Benjamin M.

    2009-01-01

    Lakes are abundant landforms and important ecosystems in Alaska, but are unevenly distributed on the landscape with expansive lake-poor regions and several lake-rich regions. Such lake-rich areas are termed lake districts and have landscape characteristics that can be considered distinctive in similar respects to mountain ranges. In this report, we explore the nature of lake-rich areas by quantitatively identifying Alaska's lake districts, describing and comparing their physical characteristics, and analyzing how Alaska lake districts are naturally organized and correspond to climatic and geophysical characteristics, as well as studied and managed by people. We use a digital dataset (National Hydrography Dataset) of lakes greater than 1 hectare, which includes 409,040 individual lakes and represents 3.3 percent of the land-surface area of Alaska. The selection criteria we used to identify lake districts were (1) a lake area (termed limnetic ratio, in percent) greater than the mean for the State, and (2) a lake density (number of lakes per unit area) greater than the mean for the State using a pixel size scaled to the area of interest and number of lakes in the census. Pixels meeting these criteria were grouped and delineated and all groups greater than 1,000 square kilometers were identified as Alaska's lake districts. These lake districts were described according to lake size-frequency metrics, elevation distributions, geology, climate, and ecoregions to better understand their similarities and differences. We also looked at where lake research and relevant ecological monitoring has occurred in Alaska relative to lake districts and how lake district lands and waters are currently managed. We identified and delineated 20 lake districts in Alaska representing 16 percent of the State, but including 65 percent of lakes and 75 percent of lake area. The largest lake districts identified are the Yukon-Kuskokwim Delta, Arctic Coastal Plain, and Iliamna lake districts with high limnetic ratios of 19, 17, and 21 percent, respectively. The three smallest districts we considered were Tetlin in the eastern interior, Menhiskof on the Alaska Peninsula, and Matanuska-Susitna at the head of Cook Inlet with limnetic ratios of 14, 9, and 9 percent, respectively. Lake density and limnetic ratio were poorly related among lake districts, such that some districts had a few large lakes like Iliamna with Lakes Iliamna and Becharof - the two largest in the State, compared to other districts with many very small lakes like Yukon-Kuskokwim Delta with 111,130 lakes and 63 percent of these less than 10 hectares. Most lake districts are in regions with relatively low precipitation, but temperature regimes varied widely among lake districts. Approximately one-half of lake districts were glaciated during the Pleistocene and similar numbers occur in regions classified as having continuous, discontinuous, and sporadic permafrost, or perennially unfrozen soils. Most districts are at low elevations (less than 250 meters) with two important exceptions being Tetlin with a mean elevation of 530 meters and Ahtna with a mean elevation of 760 meters. These higher elevation districts, particularly Ahtna, had distinct characteristics from other lake districts such as continuous permafrost and Pleistocene glaciation. Several lake districts share similar boundaries to defined ecoregions with lake districts occurring in less than one-half of these 32 ecoregions of Alaska. Most lake districts are lands fully or partly managed by the U.S. Fish and Wildlife Service and the National Park Service, with other land management by the Bureau of Land Management and State and borough government. Much of the U.S. Geological Survey's lake water-quality sampling efforts has been done in the Arctic Coastal Plain, Matanuska-Susitna, and Iliamna districts but no recorded collections in nine lake districts. Similarly, most lake limnological studies in Alaska were site-specific an

  12. Water-quality and lake-stage data for Wisconsin lakes, water year 1996

    USGS Publications Warehouse

    ,

    1997-01-01

    The purpose of this report is to provide information about the physical and chemical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected includes measurements of lake stage and in-lake water quality. Graphs of Secchi depths, surface totalphosphorus and chlorophyll-a concentrations versus time are included for lakes with two or more years of data. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, drainage area of the lake's watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published in another volume: "Water Resources Data-Wisconsin, 1996."

  13. A classification of freshwater Louisiana lakes based on water quality and user perception data.

    PubMed

    Burden, D G; Malone, R F

    1987-09-01

    An index system developed for Louisiana lakes was based on correlations between measurable water quality parameters and perceived lake quality. Support data was provided by an extensive monitoring program of 30 lakes coordinated with opinion surveys undertaken during summer 1984. Lakes included in the survey ranged from 4 to 735 km(2) in surface area with mean depths ranging from 0.5 to 8.0 m. Water quality data indicated most of these lakes are eutrophic, although many have productive fisheries and are considered recreational assets. Perception ratings of fishing quality and its associated water quality were obtained by distributing approximately 1200 surveys to Louisiana Bass Club Associaton members. The ability of Secchi disc transparency, total organic carbon, total Kjeldahl nitrogen, total phosphorus, and chlorophyll a to discriminate between perception classes was examined using probability distributions and multivariate analyses. Secchi disc and total organic carbon best reflected perceived lake conditions; however, these parameters did not provide the discrimination necessary for developing a quantitative risk assessment of lake trophic state. Consequently, an interim lakes index system was developed based on total organic carbon and perceived lake conditions. The developed index system will aid State officials in interpretating and evaluating regularly collected lake quality data, recognizing potential problem areas, and identifying proper management policies for protecting fisheries usage within the State.

  14. False-color composite image of Raco, Michigan

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This image is a false color composite of Raco, Michigan, centered at 46.39 north latitude and 84.88 east longitude. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on the 20th orbit of the Shuttle Endeavour. The area shown is approximately 20 kilometers by 50 kilometers. Raco is located at the eastern end of Michigan's upper peninsula, west of Sault Ste. Marie and south of Whitefish Bay on Lake Superior. In this color representation, darker areas in the image are smooth surfaces such as frozen lakes and other non-forested areas. The colors are related to the types of trees and the brightness is related to the amount of plant material covering the surface, called forest biomass. The Jet Propulsion Laboratory alternative photo number is P-43882.

  15. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tan, Zeli; Zhuang, Qianlai; Shurpali, Narasinha J.

    Recent studies indicated that Arctic lakes play an important role in receiving, processing, and storing organic carbon exported from terrestrial ecosystems. To quantify the contribution of Arctic lakes to the global carbon cycle, we developed a one-dimensional process-based Arctic Lake Biogeochemistry Model (ALBM) that explicitly simulates the dynamics of organic and inorganic carbon in Arctic lakes. By realistically modeling water mixing, carbon biogeochemistry, and permafrost carbon loading, the model can reproduce the seasonal variability of CO 2 fluxes from the study Arctic lakes. The simulated area-weighted CO 2 fluxes from yedoma thermokarst lakes, nonyedoma thermokarst lakes, and glacial lakes aremore » 29.5, 13.0, and 21.4 g C m -2 yr -1, respectively, close to the observed values (31.2, 17.2, and 16.5 ± 7.7 g C m -2 yr -1, respectively). The simulations show that the high CO 2 fluxes from yedoma thermokarst lakes are stimulated by the biomineralization of mobilized labile organic carbon from thawing yedoma permafrost. The simulations also imply that the relative contribution of glacial lakes to the global carbon cycle could be the largest because of their much larger surface area and high biomineralization and carbon loading. According to the model, sunlight-induced organic carbon degradation is more important for shallow nonyedoma thermokarst lakes but its overall contribution to the global carbon cycle could be limited. Overall, the ALBM can simulate the whole-lake carbon balance of Arctic lakes, a difficult task for field and laboratory experiments and other biogeochemistry models.« less

  16. Ground water resources of southeastern Oakland County, Michigan

    USGS Publications Warehouse

    Ferris, J.G.; Burt, E.M.; Stramel, G.J.; Crosthwaite, E.G.

    1954-01-01

    The area covered by this report comprises a square which measures three townships on a side and enclose 318 square miles in southeastern Oakland County. The investigation of the ground-water resources of this area was made by the U.S. Geological Survey in cooperation with the Detroit Metropolitan Area Regional Planning Commission, the Michigan Department of Conservation, and the Michigan Water Resources Commission.In 1950 the population of this nine-township area exceeded 341,000, or more than 86 percent of the total population of Oakland County. This county ranks third in the state in number of industrial establishments and workers and is fifteenth in agricultural importance. Its numerous lakes and rolling uplands contribute to its top rank in the state in the number of recreational enterprises in rural or suburban areas.The climate is moderately humid. The average annual precipitation is 30 inches and the mean air temperature is 47.2° F. Snowfall averages 38 inches in the November-April interval. The growing season averages 151 days.The regional land surface slopes from northwest to southeast and has a total relief of 360 feet. Pitted outwash plains and morainal hills that are more than 1,000 feet above sea level in the northwest corner of the area give way southeastward to a sequence of terminal moraines and intervening till plains in the middle part. These give way to the broad lake plains that cover the southeastern third of the area.The area lies on the southeast edge of the Michigan Basin and the bedrock is composed of northwest dipping strata of the Devonian and Mississippian systems. The Antrim shale, of Lake Devonian and early Mississippian age, is the oldest formation cropping out beneath the mantle of glacial Berea sandstone, and Sunbury shale overlie the Antrim and are overlain by the Coldwater shale, their areas of outcrop beneath the drift lying successively farther northwest. These formations are of early Mississippian age.Throughout the area the bedrock is covered by glacial drift which ranges in thickness from 25 to more than 350 feet. The drift increases in thickness from southeast to northwest, but considerable relief on the underlying bedrock surface greatly modifies this trend. Extensive moraines, till plains, lake plains, and gravel outwash plains cover the area. In the northwestern third of the area an extensive upland of gravel plains is dotted with lakes ranging from a few feet to more than 100 feet in depth.Precipitation is the perennial source of all water in this area, whether on the surface of underground. The average annual rainfall on the nine-townships is equivalent to a continuous supply of 450 m.g.d. or  9 times the combined annual withdrawal from all wells in the area.About 53 percent of the area is drained by the Clinton River, 44 percent by the River Rouge, and the remaining 3 percent by the Huron River. Less than one-third of the annual precipitation reappears as surface discharge from the watersheds of this area.About two-thirds of the annual precipitation on the area is lost by evaporation from water and land surfaces and by transpirations from vegetative cover. A substantial part of this large annual water loss is from the many lakes and other exposed water surfaces and from contiguous lands where the depth to the water table is slight. Average annual water losses by evapotranspiration are equivalent to about 280 m.g.d. or nearly 6 times the combined withdrawal from all ground-water supplies in the area.The principal aquifers are the alluvial deposits bordering streams and the buried outwash deposits which represent alluvial fills in preglacial or interglacial stream channels. Intensive well developments in the urban areas have greatly lowered ground-water levels in the buried outwash deposits, have brought localized problems of declining well yield, and have induced migration of mineralized waters from the underlying consolidated formations. During 1952, withdrawals of ground water in the nine township area averages about 50 m.g.d., most of this quantity being pumped from municipal wells. This annual pumpage was distributed as follows: 60 percent in Pontiac and environs; 20 percent in Birmingham, Royal Oak and Troy Township; and the remaining 20 percent throughout the suburban and rural areas.

  17. A lake-centric geospatial database to guide research and inform management decisions in an Arctic watershed in northern Alaska experiencing climate and land-use changes

    USGS Publications Warehouse

    Jones, Benjamin M.; Arp, Christopher D.; Whitman, Matthew S.; Nigro, Debora A.; Nitze, Ingmar; Beaver, John; Gadeke, Anne; Zuck, Callie; Liljedahl, Anna K.; Daanen, Ronald; Torvinen, Eric; Fritz, Stacey; Grosse, Guido

    2017-01-01

    Lakes are dominant and diverse landscape features in the Arctic, but conventional land cover classification schemes typically map them as a single uniform class. Here, we present a detailed lake-centric geospatial database for an Arctic watershed in northern Alaska. We developed a GIS dataset consisting of 4362 lakes that provides information on lake morphometry, hydrologic connectivity, surface area dynamics, surrounding terrestrial ecotypes, and other important conditions describing Arctic lakes. Analyzing the geospatial database relative to fish and bird survey data shows relations to lake depth and hydrologic connectivity, which are being used to guide research and aid in the management of aquatic resources in the National Petroleum Reserve in Alaska. Further development of similar geospatial databases is needed to better understand and plan for the impacts of ongoing climate and land-use changes occurring across lake-rich landscapes in the Arctic.

  18. Application of LANDSAT to the surveillance and control of lake eutrophication in the Great Lakes basin. [Madison and Spooner, Wisconsin

    NASA Technical Reports Server (NTRS)

    Rogers, R. H. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. By use of distilled water samples in the laboratory, and very clear lakes in the field, a technique was developed where the atmosphere and surface noise effects on LANDSAT signals from water bodies can be removed. The residual signal dependent only on the material in water was used as a basis for computer categorization of lakes by type and concentration of suspended material. Several hundred lakes in the Madison and Spooner, Wisconsin area were categorized by computer techniques for tannin or nontannin waters and for the degree of algae, silt, weeds, and bottom effects present. When the lakes are categorized as having living algae or weeds, their concentration is related to the enrichment or eutrophication of the lake.

  19. Spatial variations in geochemical characteristics of the modern Mackenzie Delta sedimentary system

    NASA Astrophysics Data System (ADS)

    Vonk, Jorien E.; Giosan, Liviu; Blusztajn, Jerzy; Montlucon, Daniel; Graf Pannatier, Elisabeth; McIntyre, Cameron; Wacker, Lukas; Macdonald, Robie W.; Yunker, Mark B.; Eglinton, Timothy I.

    2015-12-01

    The Mackenzie River in Canada is by far the largest riverine source of sediment and organic carbon (OC) to the Arctic Ocean. Therefore the transport, degradation and burial of OC along the land-to-ocean continuum for this riverine system is important to study both regionally and as a dominant representative of Arctic rivers. Here, we apply sedimentological (grain size, mineral surface area), and organic and inorganic geochemical techniques (%OC, δ13C-OC and Δ14C-OC, 143Nd/144Nd, δ2H and δ18O, major and trace elements) on particulate, bank, channel and lake surface sediments from the Mackenzie Delta, as well as on surface sediments from the Mackenzie shelf in the Beaufort Sea. Our data show a hydrodynamic sorting effect resulting in the accumulation of finer-grained sediments in lake and shelf deposits. A general decrease in organic carbon (OC) to mineral surface area ratios from river-to-sea furthermore suggests a loss of mineral-bound terrestrial OC during transport through the delta and deposition on the shelf. The net isotopic value of the terrestrial OC that is lost en route, derived from relationships between δ13C, OC and surface area, is -28.5‰ for δ13C and -417‰ for Δ14C. We calculated that OC burial efficiencies are around 55%, which are higher (∼20%) than other large river systems such as the Amazon. Old sedimentary OC ages, up to 12 14C-ky, suggest the delivery of both a petrogenic OC source (with an estimated contribution of 19 ± 9%) as well as a pre-aged terrestrial OC source. We calculated the 14C-age of this pre-aged, biogenic, component to be about 6100 yrs, or -501‰, which illustrates that terrestrial OC in the watershed can reside for millennia in soils before being released into the river. Surface sediments in lakes across the delta (n = 20) showed large variability in %OC (0.92-5.7%) and δ13C (-30.7‰ to -23.5‰). High-closure lakes, flooding only at exceptionally high water levels, hold high sedimentary OC contents (>2.5%) and young biogenic OC with a terrestrial or an autochthonous source whereas no-closure lakes, permanently connected to a river channel, hold sediments with pre-aged, terrestrial OC. The intermediate low-closure lakes, flooding every year during peak discharge, display the largest variability in OC content, age and source, likely reflecting variability in for example the length of river-lake connections, the distance to sediment source and the number of intermediate settling basins. Bank, channel and suspended sediment show variable 143Nd/144Nd values, yet there is a gradual but distinct spatial transition in 143Nd/144Nd (nearly three ε units; from -11.4 to -13.9) in the detrital fraction of lake surface sediments from the western to the eastern delta. This reflects the input of younger Peel River catchment material in the west and input of older geological source material in the east, and suggests that lake sediments can be used to assess variability in source watershed patterns across the delta.

  20. UNDERSTANDING THE IMPACT OF ENVIRONMENTAL VARIABLES ON THE LEACHING OF MERCURY-CONTAMINATED MINE WASTES FROM THE SULFUR BANK MERCURY MINE, CLEAR LAKE, CA

    EPA Science Inventory

    For nearly a century, Clear Lake in northern California has received inputs of mercury (Hg) mining wastes trom the Sulfur Bank Mercury Mine (SBMM). About 1.2 million tons of Hg-contaminated overburden and mine tailings were distributed over a 50-ha surface area due to mining oper...

  1. 76 FR 76704 - Western Technical College; Notice of Application Tendered for Filing With the Commission and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ... River, in Mahoning County, Ohio at an existing dam owned by the Ohio Department of Natural Resources... located at the existing Lake Milton Dam, currently owned by the Ohio Department of Natural Resources. Lake...-long reservoir has a surface area of 1,685 acres at a normal pool elevation of 948 feet above mean sea...

  2. Lake Vostok: An earthly analogue for the geomicrobiology on Europa

    NASA Astrophysics Data System (ADS)

    Priscu, J. C.; Christner, B. C.

    2007-12-01

    The recent discovery of more than 150 subglacial lakes beneath the Antarctic ice sheet has important implications in our search for liquid water and associated life on other icy worlds. The largest of these lakes is Lake Vostok, which has a surface area of 14000 square km and a depth of 1000 m, making it one of the largest lakes on Earth. Although we have yet to sample directly the liquid water from any of the Antarctic subglacial lakes, refrozen lakewater (accretion ice) has been sampled just above the surface of Lake Vostok. Genomic and geochemical analysis of this ice reveals that the surface lake water supports a microbial assemblage with a density approaching 1000 cells per milliliter. Sequencing and phylogenetic analysis of the 900 to 1000 base pair small subunit rRNA gene sequences obtained revealed a low diversity of clones that classify within the beta, gamma and delta subdivisions of the phylum Proteobacteria. Nearest phylogenetic neighbor analysis of these gene sequences imply that the lake contains an aerobic and anaerobic consortium of bacteria with metabolisms dedicated to iron and sulfur respiration or oxidation indicating that these metals play a role in the bioenergetics of microorganisms that occur in Lake Vostok. Sequence analysis further revealed that heterotrophic life in the lake can be sustained by chemolithotrophic production of new carbon supplemented by dissolved organic carbon released from the overlying ice sheet. Data obtained from orbiters have revealed that a deep ocean of liquid water lies under a thick chaotic ice cover on Europa where organic matter derived from comets and oxidants provided by radiation from Jupiter's magnetosphere may provide a habitat for life and a reservoir of endogenous and exogenous substances much like we observe in Lake Vostok. Future studies of Antarctic subglacial lake environments will play a crucial role in our understanding of life on Europa and other frozen worlds.

  3. 77 FR 14717 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-13

    ... preclude future actions under Superfund. This partial deletion pertains to the surface soil, unsaturated subsurface soil, surface water and sediments of Operable Unit (OU) 1, the Gateway Lake Ash Study Area, and.... Surface soil, unsaturated subsurface soil, surface water, and sediments at OU-2, OU-3, OU-4, OU-5, OU-6...

  4. The Relationship between the Distribution of Common Carp and Their Environmental DNA in a Small Lake

    PubMed Central

    Eichmiller, Jessica J.; Bajer, Przemyslaw G.; Sorensen, Peter W.

    2014-01-01

    Although environmental DNA (eDNA) has been used to infer the presence of rare aquatic species, many facets of this technique remain unresolved. In particular, the relationship between eDNA and fish distribution is not known. We examined the relationship between the distribution of fish and their eDNA (detection rate and concentration) in a lake. A quantitative PCR (qPCR) assay for a region within the cytochrome b gene of the common carp (Cyprinus carpio or ‘carp’), an ubiquitous invasive fish, was developed and used to measure eDNA in Lake Staring (MN, USA), in which both the density of carp and their distribution have been closely monitored for several years. Surface water, sub-surface water, and sediment were sampled from 22 locations in the lake, including areas frequently used by carp. In water, areas of high carp use had a higher rate of detection and concentration of eDNA, but there was no effect of fish use on sediment eDNA. The detection rate and concentration of eDNA in surface and sub-surface water were not significantly different (p≥0.5), indicating that eDNA did not accumulate in surface water. The detection rate followed the trend: high-use water > low-use water > sediment. The concentration of eDNA in sediment samples that were above the limit of detection were several orders of magnitude greater than water on a per mass basis, but a poor limit of detection led to low detection rates. The patchy distribution of eDNA in the water of our study lake suggests that the mechanisms that remove eDNA from the water column, such as decay and sedimentation, are rapid. Taken together, these results indicate that effective eDNA sampling methods should be informed by fish distribution, as eDNA concentration was shown to vary dramatically between samples taken less than 100 m apart. PMID:25383965

  5. The relationship between the distribution of common carp and their environmental DNA in a small lake.

    PubMed

    Eichmiller, Jessica J; Bajer, Przemyslaw G; Sorensen, Peter W

    2014-01-01

    Although environmental DNA (eDNA) has been used to infer the presence of rare aquatic species, many facets of this technique remain unresolved. In particular, the relationship between eDNA and fish distribution is not known. We examined the relationship between the distribution of fish and their eDNA (detection rate and concentration) in a lake. A quantitative PCR (qPCR) assay for a region within the cytochrome b gene of the common carp (Cyprinus carpio or 'carp'), an ubiquitous invasive fish, was developed and used to measure eDNA in Lake Staring (MN, USA), in which both the density of carp and their distribution have been closely monitored for several years. Surface water, sub-surface water, and sediment were sampled from 22 locations in the lake, including areas frequently used by carp. In water, areas of high carp use had a higher rate of detection and concentration of eDNA, but there was no effect of fish use on sediment eDNA. The detection rate and concentration of eDNA in surface and sub-surface water were not significantly different (p≥0.5), indicating that eDNA did not accumulate in surface water. The detection rate followed the trend: high-use water > low-use water > sediment. The concentration of eDNA in sediment samples that were above the limit of detection were several orders of magnitude greater than water on a per mass basis, but a poor limit of detection led to low detection rates. The patchy distribution of eDNA in the water of our study lake suggests that the mechanisms that remove eDNA from the water column, such as decay and sedimentation, are rapid. Taken together, these results indicate that effective eDNA sampling methods should be informed by fish distribution, as eDNA concentration was shown to vary dramatically between samples taken less than 100 m apart.

  6. Bathymetry of Bonnie Doone Lake, Kornbow Lake, Mintz Pond, and Glenville Lake, Cumberland County, North Carolina, 1996-98

    USGS Publications Warehouse

    Giorgino, M.J.; Strain, R.E.

    1999-01-01

    Bathymetric surveys were conducted at four water-supply impoundments of Little Cross Creek in Cumberland County, North Carolina. The surveys were conducted in April 1996 at Mintz Pond and Glenville Lake, and in January 1998 at Bonnie Doone Lake and Kornbow Lake. The resulting bathymetric maps are the first to cover the entire range in depth for these reservoirs and provide a framework for future evaluations of bathymetry and storage capacity. Bathymetric maps were constructed from depth and position data collected at each reservoir. A boat-mounted, research-grade fathometer was used to record water depths with a vertical accuracy of 0.1 foot. At Mintz Pond and Glenville Lake, position was measured by using a wide-band laser tracking system interfaced with a total station survey instrument. This positioning method required multiple land-based control points to be established and was hampered by line-of-sight restrictions between the control points and the boat. At Bonnie Doone Lake and Kornbow Lake, a global positioning system was used to collect differentially corrected location data. This positioning method enabled more rapid data collection, eliminated the need for land-based control points, and provided improved data coverage. Spillway elevations range from 172.8 feet above mean sea level at Bonnie Doone Lake to 113.1 feet at Glenville Lake. Surface area and storage volume were computed for each reservoir and were related to water-surface elevations at 1-foot intervals. The combined surface acreage of the four Little Cross Creek reservoirs at their full-pool elevations is 120.97 acres, consisting of 21.20 acres at Bonnie Doone Lake, 47.09 acres at Kornbow Lake, 15.56 acres at Mintz Pond, and 37.12 acres at Glenville Lake. The four reservoirs have a combined usable storage capacity of 674.91 acre-feet, which is the sum of 127.93 acre-feet in Bonnie Doone Lake, 320.62 acre-feet in Kornbow Lake, 53.25 acre-feet in Mintz Pond, and 173.11 acre-feet in Glenville Lake.

  7. Dead sea asphalts: historical aspects

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nissenbaum, A.

    1978-05-01

    Asphalts are present in the Dead Sea basin in three forms: (1) huge blocks, up to 100 tons in weight, composed of extremely pure (>99.99%) solid asphalt occasionally found floating on the lake, (2) veins, seepages, and cavity and fissure fillings in Lower Cretaceous to Holocene rocks, and (3) ozocerite veins on the eastern shore of the lake. Dead Sea asphalts probably have been documented over a longer period of time than any other hydrocarbon deposit--from antiquity to the 19th century. Major uses of asphalt from the Dead Sea have been as an ingredient in the embalming process, for medicinalmore » purposes, for fumigation, and for agriculture. The first known war for control of a hydrocarbon deposit was in the Dead Sea area in 312 B.C. between the Seleucid Syrians and the Nabatean Arabs who lived around the lake. Surface manifestations of asphalt are linked closely to tectonic activity. In the lake itself, the asphalt is associated with diapirs During certain historic periods, tectonic and diapiric activity caused frequent liberation to the Dead Sea surface of semiliquid asphalt associated with large amounts of hydrogen sulfide gas. When the tectonic activity was attenuated, as in the 19th and 20th centuries, the rate of asphalt seepage to the bottom sediments of the Dead Sea was much slower and the asphalt solidified on the lake bottom. The release of asphalt to the surface became much more sporadic, and may have resulted in part from earthquakes. Thus, future asphalt prospecting in the Dead Sea area should be conducted along the boundaries of diapirs or their associated faults.« less

  8. Abandoned Rayrock uranium mill tailings in the Northwest Territories: Environmental conditions and radiological impact

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Veska, E.; Eaton, R.S.

    Field and laboratory investigations were undertaken of the environment surrounding abandoned U mill tailings at Rayrock, Northwest Territories, Canada, to examine the extent of 226Ra and U contamination. Samples of ground water, surface water, and unconsolidated geological material from the Rayrock area were collected for chemical and radiochemical analyses. Results indicated that the surface waters contained levels of 226Ra as high as 20 Bq L-1, 210Pb as high as 1.1 Bq L-1, and ground water U as high as 2800 micrograms L-1. Lower levels of 226Ra, 210Pb, and U, 3.6 Bq L-1, 0.5 Bq L-1, and 4 micrograms L-1, respectively,more » were found in a small lake adjacent to the tailings area. Analysis of tailings and soil in the immediate vicinity indicates that the radionuclides and U are mobilized and can move within the tailings. Some of the mobilized radionuclides will be bound by the surrounding peat. The remainder may move to Lake Alpha in ground water. Surface water flow also transports some contaminants both in the water of Alpha Creek and by washing tailings into Lake Alpha. The potential annual external and internal dose equivalents to a hypothetical resident were calculated based on exposure from the abandoned U mill tailings, drinking water, and fish caught in the lakes in the vicinity of the tailings. While Alpha Creek and Lake Alpha water showed evidence of contamination, the rest of the water system and the fish were at natural background levels of radioactivity.« less

  9. Impacts of the land-lake breeze of the Volta reservoir on the diurnal cycle of cloudiness and precipitation

    NASA Astrophysics Data System (ADS)

    Buchholz, Marcel; Fink, Andreas H.; Knippertz, Peter; Yorke, Charles

    2017-04-01

    Lake Volta in Ghana is the artificial lake on Earth with the largest surface area (8502 km2). It has been constructed in the early 1960s, with the lake being filled around 1966. Land-lake breezes and their effects on the diurnal cycle of local wind systems, cloudiness, and precipitation have been studied for several tropical lakes, among which studies on the effects of Lake Victoria in East Africa are one of the most perceived ones. To date, no studies on the strengths and effects of the land-lake breeze of the Volta reservoir are known to the authors. Using surface station data, a variety of satellite data on clouds and precipitation, and a convection-resolving regional model, the land-lake breeze and its impacts were studied for Lake Volta between 1998 and 2015. The observational data sets confirm a significant land-lake circulation. The only manned weather station operated by the Ghana Meteorological Service that is situated at the lake is Kete Krachi. Hourly observations for 2006 and 2014 show on several days a clearing of skies in the afternoon associated with a shift in the surface winds from southwest to southeast, the latter potentially indicating a lake breeze effect. Cloud occurrence frequency derived from the CLARA-A2, MODIS, and CLAAS2 cloud masks and the cloud physical properties from CLAAS2 clearly show the development of clouds at the lake breeze front in the course of the morning and around mid-day. This effect is most pronounced in March when also the difference between the surface temperatures of the lake and the desiccated land surface is strongest. During the peak of the wet season in July, the lake breeze cloudiness is masked by a high background cloudiness and likely also weaker due to the strong southwesterly monsoon flow that tends to weaken the land-lake circulation. However, the precipitation signal was found to be strongest in July, most probably due to the fact that in boreal fall, winter and spring, the lake breeze cloudiness often fails to develop into afternoon showers or thunderstorms, or if, they are short-lived with substantial below-cloud evaporation. Two cases in 2007 and 2014 were synoptically analyzed with weather charts and modeled using the COSMO model, the current regional operational weather forecasting model of the German Weather Service (DWD). The COSMO experiments with and without the lake were integrated for 48 hours at convection-resolving resolution of 2.8 km. Initial and boundary conditions were taken from ECWMF operational analysis. Model results confirm the development of the daytime lake breeze and suggest that the existence of the lake has substantially changed the local circulation, cloudiness and precipitation regime. Our results imply a significant impact of the artificial lake on the local climate and ecosystems that warrants further study.

  10. Southeastern extension of the Lake Basin fault zone in south- central Montana: implications for coal and hydrocarbon exploration ( USA).

    USGS Publications Warehouse

    Robinson, L.N.; Barnum, B.E.

    1986-01-01

    The Lake Basin fault zone consists mainly of en echelon NE-striking normal faults that have been interpreted to be surface expressions of left-lateral movement along a basement wrench fault. Information gathered from recent field mapping of coal beds and from shallow, closely-spaced drill holes resulted in detailed coal bed correlations, which revealed another linear zone of en echelon faulting directly on the extended trend of the Lake Basin fault zone. This faulted area, referred to as the Sarpy Creek area, is located 48 km E of Hardin, Montana. It is about 16 km long, 13 km wide, and contains 21 en echelon normal faults that have an average strike of N 63oE. We therefore extend the Lake Basin fault zone 32 km farther SE than previously mapped to include the Sarpy Creek area. The Ash Creek oil field, Wyoming, 97 km due S of the Sarpy Creek area, produces from faulted anticlinal structues that have been interpreted to be genetically related to the primary wrench-fault system known as the Nye-Bowler fault zone. The structural similarities between the Sarpy Creek area and the Ash Creek area indicate that the Sarpy Creek area is a possible site for hydrocarbon accumulation.-from Authors

  11. Distribution and abundance of larval fish in the nearshore waters of western Lake Huron

    USGS Publications Warehouse

    O'Gorman, Robert

    1983-01-01

    Ichthyoplankton was collected at 17 nearshore (bottom depth ≥5 m but ≤10 m) sites in western Lake Huron during 1973–75 with a 0.5-m net of 351-micron mesh towed at 99 m/min. Larvae of rainbow smelt (Osmerus mordax) dominated late spring and early summer catches and larvae of alewives (Alosa pseudoharengus) the midsummer catches. Larval yellow perch (Perca flavescens) were caught in early summer but were rarely the dominant species. The time of spawning and hatching, and thus occurrence of larvae, differed between areas but was less variable for alewives than for yellow perch. The appearance of larvae in Saginaw Bay was followed successively by their appearance in southern, central, and northern Lake Huron. Rainbow smelt were most abundant in northern Lake Huron and yellow perch and alewives in inner Saginaw Bay. Densities of either rainbow smelt or alewives occasionally exceeded 1/m3, whereas those of yellow perch never exceeded 0.1/m3. Abundance of alewives was usually highest 1 to 3 m beneath the surface and that of rainbow smelt 2 to at least 6 m beneath the surface. Important nursery areas of rainbow smelt were in bays and off irregular coastlines and those of yellow perch were in bays. All nearshore waters seemed equally important as nursery areas of alewives.

  12. Sources and distribution of microplastics in China's largest inland lake - Qinghai Lake.

    PubMed

    Xiong, Xiong; Zhang, Kai; Chen, Xianchuan; Shi, Huahong; Luo, Ze; Wu, Chenxi

    2018-04-01

    Microplastic pollution was studied in China's largest inland lake - Qinghai Lake in this work. Microplastics were detected with abundance varies from 0.05 × 10 5 to 7.58 × 10 5 items km -2 in the lake surface water, 0.03 × 10 5 to 0.31 × 10 5 items km -2 in the inflowing rivers, 50 to 1292 items m -2 in the lakeshore sediment, and 2 to 15 items per individual in the fish samples, respectively. Small microplastics (0.1-0.5 mm) dominated in the lake surface water while large microplastics (1-5 mm) are more abundant in the river samples. Microplastics were predominantly in sheet and fiber shapes in the lake and river water samples but were more diverse in the lakeshore sediment samples. Polymer types of microplastics were mainly polyethylene (PE) and polypropylene (PP) as identified using Raman Spectroscopy. Spatially, microplastic abundance was the highest in the central part of the lake, likely due to the transport of lake current. Based on the higher abundance of microplastics near the tourist access points, plastic wastes from tourism are considered as an important source of microplastics in Qinghai Lake. As an important area for wildlife conservation, better waste management practice should be implemented, and waste disposal and recycling infrastructures should be improved for the protection of Qinghai Lake. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hoffman, Matthew J.; Perego, Mauro; Andrews, Lauren C.

    Moulins permit access of surface meltwater to the glacier bed, causing basal lubrication and ice speedup in the ablation zone of western Greenland during summer. In spite of the substantial impact of moulins on ice dynamics, the conditions under which they form are poorly understood. We assimilate a time series of ice surface velocity from a network of eleven Global Positioning System receivers into an ice sheet model to estimate ice sheet stresses during winter, spring, and summer in a ~30 × 10 km region. Surface-parallel von Mises stress increases slightly during spring speedup and early summer, sufficient to allowmore » formation of 16% of moulins mapped in the study area. Conversely, 63% of moulins experience stresses over the tensile strength of ice during a short (hours) supraglacial lake drainage event. Lake drainages appear to control moulin density, which is itself a control on subglacial drainage efficiency and summer ice velocities.« less

  14. Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland

    DOE PAGES

    Hoffman, Matthew J.; Perego, Mauro; Andrews, Lauren C.; ...

    2018-01-17

    Moulins permit access of surface meltwater to the glacier bed, causing basal lubrication and ice speedup in the ablation zone of western Greenland during summer. In spite of the substantial impact of moulins on ice dynamics, the conditions under which they form are poorly understood. We assimilate a time series of ice surface velocity from a network of eleven Global Positioning System receivers into an ice sheet model to estimate ice sheet stresses during winter, spring, and summer in a ~30 × 10 km region. Surface-parallel von Mises stress increases slightly during spring speedup and early summer, sufficient to allowmore » formation of 16% of moulins mapped in the study area. Conversely, 63% of moulins experience stresses over the tensile strength of ice during a short (hours) supraglacial lake drainage event. Lake drainages appear to control moulin density, which is itself a control on subglacial drainage efficiency and summer ice velocities.« less

  15. Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland

    NASA Astrophysics Data System (ADS)

    Hoffman, Matthew J.; Perego, Mauro; Andrews, Lauren C.; Price, Stephen F.; Neumann, Thomas A.; Johnson, Jesse V.; Catania, Ginny; Lüthi, Martin P.

    2018-01-01

    Moulins permit access of surface meltwater to the glacier bed, causing basal lubrication and ice speedup in the ablation zone of western Greenland during summer. Despite the substantial impact of moulins on ice dynamics, the conditions under which they form are poorly understood. We assimilate a time series of ice surface velocity from a network of eleven Global Positioning System receivers into an ice sheet model to estimate ice sheet stresses during winter, spring, and summer in a ˜30 × 10 km region. Surface-parallel von Mises stress increases slightly during spring speedup and early summer, sufficient to allow formation of 16% of moulins mapped in the study area. In contrast, 63% of moulins experience stresses over the tensile strength of ice during a short (hours) supraglacial lake drainage event. Lake drainages appear to control moulin density, which is itself a control on subglacial drainage efficiency and summer ice velocities.

  16. Bathymetric Survey and Storage Capacity of Upper Lake Mary near Flagstaff, Arizona

    USGS Publications Warehouse

    Hornewer, Nancy J.; Flynn, Marilyn E.

    2008-01-01

    Upper Lake Mary is a preferred drinking-water source for the City of Flagstaff, Arizona. Therefore, storage capacity and sedimentation issues in Upper Lake Mary are of interest to the City. The U.S. Geological Survey, in cooperation with the City of Flagstaff, collected bathymetric and land-survey data in Upper Lake Mary during late August through October 2006. Water-depth data were collected using a single-beam, high-definition fathometer. Position data were collected using real-time differential global position system receivers. Data were processed using commercial software and imported into geographic information system software to produce contour maps of lakebed elevations and for the computation of area and storage-capacity information. At full pool (spillway elevation of 6,828.5 feet above mean sea level), Upper Lake Mary has a storage capacity of 16,300 acre-feet, a surface area of 939 acres, a mean depth of 17.4 feet, and a depth near the dam of 39 feet. It is 5.6 miles long and varies in width from 308 feet near the central, narrow portion of the lake to 2,630 feet in the upper portion. Comparisons between this survey and a previous survey conducted in the 1950s indicate no apparent decrease in reservoir area or storage capacity between the two surveys.

  17. Hydrology of Lake Tohopekaliga, Osceola County, Florida

    USGS Publications Warehouse

    Phelps, G.G.

    1982-01-01

    Lake Tohopekaliga, one of the major lakes in central Florida, provides flood control in the upper Kissimmee River basin, recreation for fishermen and boaters, water for live-stock, esthetic surroundings for homesites, and serves as a receiving body for treated effluent from municipal sewage treatment plants. The purpose of this map report is to provide a general reconnaissance of the lake, based primarily on existing geologic , hydrologic and water-quality data. The lake has a surface area of about 30 square miles and a mean depth of about 5 feet. Maximum depth measured was about 13 feet. Inflow to the lake comes from Shingle Creek and St. Cloud canal and outflow is through the South-port canal. Regulation of lake levels for flood control began in the early 1960 's and has resulted in a decrease in the range of lake stage of about 3 feet. Concentrations of pesticide residues in lake bottom sediments do not appear to have increased from 1972 to 1980. The lake has abundant aquatic vegetation, the amount and extent of which varies with fluctuating water levels. Water-quality data collected between 1954-77 are summarized in the report and additional data collected in 1980 are also shown. The range of plant nutrient concentrations measured in May 1980 are: Total organic nitrogen 0.71-2.2 milligrams per liter. Most water-quality parameters vary from one area of the lake to another because of restricted areal circulation due to the shape of the lake. (USGS)

  18. A post-Calumet shoreline along southern Lake Michigan

    USGS Publications Warehouse

    Capps, D.K.; Thompson, T.A.; Booth, R.K.

    2007-01-01

    The southern shore of Lake Michigan is the type area for many of ancestral Lake Michigan's late Pleistocene lake phases, but coastal deposits and features of the Algonquin phase of northern Lake Michigan, Lake Huron, and Lake Superior are not recognized in the area. Isostatic rebound models suggest that Algonquin phase deposits should be 100 m or more below modern lake level. A relict shoreline, however, exists along the lakeward margin of the Calumet Beach that was erosional west of Deep River and depositional east of the river. For this post-Calumet shoreline, the elevation of basal foreshore deposits east of Deep River and the base of the scarp west of Deep River indicate a slightly westward dipping water plane that is centered at ???184 m above mean sea level. Basal foreshore elevations also indicate that lake level fell ???2 m during the development of the shoreline. The pooled mean of radiocarbon dates from the surface of the peat below post-Calumet shoreline foreshore deposits indicate that the lake transgressed over the peat at 10,560 ?? 70 years B.P. Pollen assemblages from the peat are consistent with this age. The elevation and age of the post-Calumet shoreline are similar to the Main Algonquin phase of Lake Huron. Recent isostatic rebound models do not adequately address a high-elevation Algonquin-age shoreline along the southern shore of Lake Michigan, but the Goldthwait (1908) hinge-line model does. ?? 2006 Springer Science+Business Media B.V.

  19. Pesticides in mountain yellow-legged frogs (Rana muscosa) from the Sierra Nevada Mountains of California, USA

    USGS Publications Warehouse

    Fellers, G.M.; McConnell, L.L.; Pratt, D.; Datta, S.

    2004-01-01

    In 1997, pesticide concentrations were measured in mountain yellow-legged frogs (Rana muscosa) from two areas in the Sierra Nevada Mountains of California, USA. One area (Sixty Lakes Basin, Kings Canyon National Park) had large, apparently healthy populations of frogs. A second area (Tablelands, Sequoia National Park) once had large populations, but the species had been extirpated from this area by the early 1980s. The Tablelands is exposed directly to prevailing winds from agricultural regions to the west. When an experimental reintroduction of R. muscosa in 1994 to 1995 was deemed unsuccessful in 1997, the last 20 (reintroduced) frogs that could be found were collected from the Tablelands, and pesticide concentrations in both frog tissue and the water were measured at both the Tablelands and at reference sites at Sixty Lakes. In frog tissues, dichlorodiphenyldichloroethylene (DDE) concentration was one to two orders of magnitude higher than the other organochlorines (46 ?? 20 ng/g wet wt at Tablelands and 17 ?? 8 Sixty Lakes). Both ??-chlordane and trans-nonachlor were found in significantly greater concentrations in Tablelands frog tissues compared with Sixty Lakes. Organophosphate insecticides, chlorpyrifos, and diazinon were observed primarily in surface water with higher concentrations at the Tablelands sites. No contaminants were significantly higher in our Sixty Lakes samples.

  20. Characterization of Titan surface scenarios combining Cassini SAR images and radiometric data

    NASA Astrophysics Data System (ADS)

    Ventura, B.; Notarnicola, C.; Casarano, D.; Janssen, M.; Posa, F.; Cassini RADAR Science Team

    2009-04-01

    A great amount of data and images was provided by the radar on Cassini probe, thus opening and suggesting new scenarios about Titan's formation and evolution. An important result was the detection, among the peculiar and heterogeneous Titan's surface features, of lakes most likely constituted by liquid hydrocarbons, thus supporting the hypothesis of a methane cycle similar to water cycle on Earth.These areas, which resemble terrestrial lakes, seem to be sprinkled all over the high latitudes surrounding Titan's pole. The abundant methane in Titan's atmosphere combined with the low temperature, 94 K, lead scientists to interpret them as lakes of liquid methane or ethane. In this work, scattering models and a Bayesian inversion algorithm are applied in order to characterize lake and land surfaces. The possibility of combining the SAR data with radiometric ones on both lakes and neighboring land areas is also presented. Radar backscattering from lakes is described in terms of a double layer model, consisting of Bragg or facets scattering for the upper liquid layer and the Integral Equation Model (IEM) model for the lower solid surface. Furthermore, by means of a gravity-capillary wave model (Donelan-Pierson), the wave spectra of liquid hydrocarbons surfaces are introduced as a function of wind speed and direction. Theoretical radar backscattering coefficient values are compared with the experimental ones collected by the radar in order to estimate physical and morphological surface parameters, and to evaluate their compatibility with the expected constituents for Titan surfaces. This electromagnetic analysis is the starting point for a statistical inversion algorithm which allows determining limits on the parameters values, especially on the optical thickness and wind speed of the lakes. The physical surface parameters inferred by using the inversion algorithm are used as input for a forward radiative transfer model calculation to obtain simulated brightness temperatures. The radiometric model has been introduced to further verify the values ranges for the different parameters. In fact the same parameters derived from the radar data analysis have been used as input for the radiometric model. The comparison between the observed and computed brightness temperatures has been performed in order to address the consistency of the observations from the two instruments and to determine the coarse characteristics of the surface parameters. For both radar and radiometric data the soil medium is horizontally stratified into 2 layers. Each layer can be characterized by different absorption coefficients depending on the optical thickness, dielectric constant and physical temperature. In this algorithm, the starting point is the map of optical thickness derived from the SAR images. The simulated brightness temperature is calculated by applying the forward radiative transfer model to the optical thickness map with the same hypotheses assumed to derive it. The simulation is also carried out on the neighboring land areas by considering a double layer model including a contribution of volume scattering. Each layer is described in terms of dielectric constant values, albedo and roughness parameters with the hypothesis of water ice ammonia on layers of solid hydrocarbons and organic compounds like tholins. The analysis is applied to the areas detected on flybys 25 and 30. One important result arises from the analysis of the inverted optical thickness on deep lakes. In this case, found values of optical thickness can be considered limit values because, beyond these values, a complete attenuation can be considered. This limit value is important as it is stable even if the other parameters vary. Starting from this point, posing the condition of a complete attenuation of the second layer, i.e. fixing the value of the optical thickness, the algorithm can be used to estimate the wind speed. The retrieved values vary between 0.2 to 0.5 m/s. The first results also show a good agreement between the simulated data and the measured brightness temperature for both the liquid surface and the surrounding areas. In the last case, a good agreement is obtained only if the contribution from volume scattering is included in the model

  1. A Digital 3D-Reconstruction of the Younger Dryas Baltic Ice Lake

    NASA Astrophysics Data System (ADS)

    Jakobsson, M.; Alm, G.; Bjorck, S.; Lindeberg, G.; Svensson, N.

    2005-12-01

    A digital 3D-reconstruction of the final stage of the ice dammed Baltic Ice Lake (BIL), dated to the very end of the Younger Dryas cold period (ca. 11 600 cal. yr BP) has been compiled using a combined bathymetric-topographic Digital Terrain Model (DTM), Scandinavian ice sheet limits, Baltic Sea Holocene bottom sediment thickness information, and a paleoshoreline database maintained at the Lund University. The combined bathymetric-topographic Digital Terrain Model (DTM) model used to reconstruct the ice dammed lake was compiled specifically for this study from publicly available data sets. The final DTM is in the form of a digital grid on Lamberts Equal Area projection with a resolution of 500 x 500 m, which permits a much more detailed reconstruction of the BIL than previously made. The lake was constructed through a series of experiments where mathematical algorithms were applied to fit the paleolake's surface through the shoreline database. The accumulated Holocene bottom sediments in the Baltic Sea were subsequently subtracted from the present bathymetry in our reconstruction. This allows us to estimate the Baltic Ice Lake's paleobathymetry, area, volume, and hypsometry, which will comprise key input data to lake/climate modeling exercises following this study. The Scandinavian ice sheet margin eventually retreated north of Mount Billingen, which was the high point in terrain of Southern central Sweden bordering to lower terrain further to the North. As a consequence, the BIL was catastrophically drained through this area, resulting in a 25 m drop of the lake level. With our digital BIL model we estimate that approximately 7, 800 km3 of water drained during this event and that the ice dammed lake area was reduced with ca 18 percent. The digital BIL reconstruction is analyzed using 3D-visualization techniques that provide new detailed information on the paleogeography in the area, both before and after the lake drainage, with implications for interpretations of geological records concerning the post-glacial environmental development of southern Scandinavia.

  2. In-situ erosion of cohesive sediment in a large shallow lake experiencing long-term decline in wind speed

    NASA Astrophysics Data System (ADS)

    Wu, Tingfeng; Timo, Huttula; Qin, Boqiang; Zhu, Guangwei; Janne, Ropponen; Yan, Wenming

    2016-08-01

    In order to address the major factors affecting cohesive sediment erosion using high-frequency in-situ observations in Lake Taihu, and the response of this erosion to long-term decline in wind speed, high-frequency meteorological, hydrological and turbidity sensors were deployed to record continuous field wind-induced wave, current and sediment erosion processes; Statistical analyses and mathematic modeling spanning 44 years were also conducted. The results revealed that the unconsolidated surficial cohesive sediment frequently experiences the processes of erosion, suspension and deposition. Wind waves, generated by the absorption of wind energy, are the principal force driving this cycle. When the wavelength-to-water depth ratio (L/D) is 2-3, wave propagation is affected by lakebed friction and surface erosion occurs. When L/D > 3, the interaction between wave and lakebed increases to induce massive erosion. However, influenced by rapid urbanization in the Lake Taihu basin, wind speed has significantly decreased, by an average rate of -0.022 m s-1 a-1, from 1970 to 2013. This has reduced the erodible area, represented by simulated L/D, at a rate of -16.9 km2 a-1 in the autumn and winter, and -8.1 km2 a-1 in the spring and summer. This significant decrease in surface erosion area, and the near disappearance of areas experiencing massive erosion, imply that Lake Taihu has become calmer, which can be expected to have adverse effects on the lake ecosystem by increasing eutrophication and nuisance cyanobacteria blooms.

  3. Quartz-molybdenite veins in the Priestly Lake granodiorite, north-central Maine

    USGS Publications Warehouse

    Ayuso, Robert A.; Shank, Stephen G.

    1983-01-01

    Quartz-molybdenite veins up to 15 cm in width occur in fine to medium-grained porphyritic biotite-hornblende granodiorite at Priestly Lake north-central Maine. An area of about 150 m x 150 m contains quartz-molybdenite veins; a larger area is characterized by barren quartz veins. Quartz-molybdenite veins are concentrated within the most felsic variants of the intrusion as suggested by lower mafic mineral contents. The pluton has a narrow range in SiO2 (67-70 wt.%), major oxides, and in trace-element compositions. Molybdenite occurs as coarse grained clusters in pockets within the quartz veins, and fills fractures in the quartz veins and host rocks. Disseminated molybdenite in the granodiorite is relatively rare and occurs only in the area characterized by a high density of quartz veins (up to 50 veins per square meter). Alteration envelopes along the quartz veins are very thin or absent, although in some areas the granodiorite appears to be selectively and pervasively altered. Sericite, chlorite, epidote, calcite, pyrite, and quartz are concentrated near the quartz-molybdenite veins. Many of the field and geochemical characteristics of the Priestly Lake pluton are unlike those of major molybdenum-producing areas (Climax, Henderson, Urad). For example, the area of alteration seems to be of limited extent, the host rock is not intensely altered hydrothermally at the surface, the density of fractures is rather low in the mineralized area, and the amount of disseminated molybdenite appears to be small. However, the Priestly Lake pluton may be a small fraction of a concealed batholith as suggested by geophysical data. It is conceivable that the type of mineralization at the surface might be the expression of more extensive molybdenite mineralization at depth. The quartz-molybdenite veins in the Priestly Lake pluton are significant because they indicate that potential molybdenum sources for producing mineralized granites were available at depth. Future studies should be aimed at delineating the area of quartz-molybdenite mineralization, documenting hydrothermal alteration and zonation, determining fracture density, and evaluating the sulfide assemblage.

  4. The Pine-Popple River basin--Hydrology of a wild river area, northeastern Wisconsin

    USGS Publications Warehouse

    Oakes, Edward L.; Field, Stephen J.; Seeger, Lawrence P.

    1973-01-01

    The Pine and Popple Rivers, virtually unaltered by man, flow through a semiprimitive area of forests, lakes, and glacial hills. White-water streams, natural lakes, fish and animal life, and abundant vegetation contribute to the unique recreational and aesthetic characteristics of the area. Resource planning or development should recognize the interrelationships within the hydrologic system and the possible effects of water and land-use changes upon the wild nature of the area. The basin covers about 563 square miles in northeastern Wisconsin. Swamps and wetlands cover nearly 110 square miles, and the 70 lakes cover about 11 square miles. The undulating topography is formed by glacial deposits overlying an irregular, resistant surface of bedrock. An annual average of 30 inches of precipitation, highest from late spring to early autumn, falls on the basin. Of this amount, evapotranspiration, highest in mid summer and late summer, averages 19 inches; the remaining 11 inches is runoff, which is highest in spring and early summer. Ground water from the glacial drift is the source of water for the minor withdrawal use in the basin. Ground-water movement is to streams and lakes and regionally follows the slope of topography and the bedrock surface, which is generally west to east. Ground water is of good quality, although locally high in iron. The major uses of water are for recreation and power generation. Domestic use is slight. No water is withdrawn from lakes or streams, and no sewage or industrial wastes are added to lakes or streams. Most of the flow of the Pine River is used for power generation. The main stems of the Pine and Popple Rivers contain 114 canoeable miles, of which 95 percent is without such major obstructions as falls or large rapids. In general streams support cold-water fish, and lakes support warm-water fish. Trout is the principal stream and game fish in the basin. The basin has no significant water problems. Future development between the Pine River power plant and the mouth of the Pine River should have little effect on the western two-thirds of the basin, already largely protected by public ownership or development planning agreements.

  5. Use of chemical and isotopic tracers to characterize the interactions between ground water and surface water in mantled karst

    USGS Publications Warehouse

    Katz, B.G.; Coplen, T.B.; Bullen, T.D.; Hal, Davis J.

    1997-01-01

    In the mantled karst terrane of northern Florida, the water quality of the Upper Floridan aquifer is influenced by the degree of connectivity between the aquifer and the surface. Chemical and isotopic analyses [18O/16O (??18O), 2H/1H (??D), 13C/12C (??13C), tritium(3H), and strontium-87/strontium-86(87Sr/86Sr)]along with geochemical mass-balance modeling were used to identify the dominant hydrochemical processes that control the composition of ground water as it evolves downgradient in two systems. In one system, surface water enters the Upper Floridan aquifer through a sinkhole located in the Northern Highlands physiographic unit. In the other system, surface water enters the aquifer through a sinkhole lake (Lake Bradford) in the Woodville Karst Plain. Differences in the composition of water isotopes (??18O and ??D) in rainfall, ground water, and surface water were used to develop mixing models of surface water (leakage of water to the Upper Floridan aquifer from a sinkhole lake and a sinkhole) and ground water. Using mass-balance calculations, based on differences in ??18O and ??D, the proportion of lake water that mixed with meteoric water ranged from 7 to 86% in water from wells located in close proximity to Lake Bradford. In deeper parts of the Upper Floridan aquifer, water enriched in 18O and D from five of 12 sampled municipal wells indicated that recharge from a sinkhole (1 to 24%) and surface water with an evaporated isotopic signature (2 to 32%) was mixing with ground water. The solute isotopes, ??13C and 87Sr/86Sr, were used to test the sensitivity of binary and ternary mixing models, and to estimate the amount of mass transfer of carbon and other dissolved species in geochemical reactions. In ground water downgradient from Lake Bradford, the dominant processes controlling carbon cycling in ground water were dissolution of carbonate minerals, aerobic degradation of organic matter, and hydrolysis of silicate minerals. In the deeper parts of the Upper Floridan aquifer, the major processes controlling the concentrations of major dissolved species included dissolution of calcite and dolomite, and degradation of organic matter under oxic conditions. The Upper Floridan aquifer is highly susceptible to contamination from activities at the land surface in the Tallahassee area. The presence of post-1950s concentrations of 3H in ground water from depths greater than 100 m below land surface indicates that water throughout much of the Upper Floridan aquifer has been recharged during the last 40 years. Even though mixing is likely between ground water and surface water in many parts of the study area, the Upper Floridan aquifer produces good quality water, which due to dilution effects shows little if any impact from trace elements or nutrients that are present in surface waters.The water quality of the Upper Floridan aquifer is influenced by the degree of connectivity between the aquifer and the surface water. Chemical and isotopic analyses, tritium, and strontium-87/strontium-86 along with geochemical mass-balance modeling were used to identify the dominant hydrochemical processes that control the composition of groundwater. Differences in the composition of water isotopes in rainfall, groundwater and surface water were used to develop mixing models of surface water and groundwater. Even though mixing is likely between groundwater and surface water in many parts of the study area, the Upper Floridan aquifer produces good quality water, showing little impact from trace elements present in surface waters.

  6. Modeling CO 2 emissions from Arctic lakes: Model development and site-level study

    DOE PAGES

    Tan, Zeli; Zhuang, Qianlai; Shurpali, Narasinha J.; ...

    2017-09-14

    Recent studies indicated that Arctic lakes play an important role in receiving, processing, and storing organic carbon exported from terrestrial ecosystems. To quantify the contribution of Arctic lakes to the global carbon cycle, we developed a one-dimensional process-based Arctic Lake Biogeochemistry Model (ALBM) that explicitly simulates the dynamics of organic and inorganic carbon in Arctic lakes. By realistically modeling water mixing, carbon biogeochemistry, and permafrost carbon loading, the model can reproduce the seasonal variability of CO 2 fluxes from the study Arctic lakes. The simulated area-weighted CO 2 fluxes from yedoma thermokarst lakes, nonyedoma thermokarst lakes, and glacial lakes aremore » 29.5, 13.0, and 21.4 g C m -2 yr -1, respectively, close to the observed values (31.2, 17.2, and 16.5 ± 7.7 g C m -2 yr -1, respectively). The simulations show that the high CO 2 fluxes from yedoma thermokarst lakes are stimulated by the biomineralization of mobilized labile organic carbon from thawing yedoma permafrost. The simulations also imply that the relative contribution of glacial lakes to the global carbon cycle could be the largest because of their much larger surface area and high biomineralization and carbon loading. According to the model, sunlight-induced organic carbon degradation is more important for shallow nonyedoma thermokarst lakes but its overall contribution to the global carbon cycle could be limited. Overall, the ALBM can simulate the whole-lake carbon balance of Arctic lakes, a difficult task for field and laboratory experiments and other biogeochemistry models.« less

  7. A synthesis of thermokarst lake water balance in high-latitude regions of North America from isotope tracers

    USGS Publications Warehouse

    MacDonald, Lauren A.; Wolfe, Brent B.; Turner, Kevin W.; Anderson, Lesleigh; Arp, Christopher D.; Birks, Jean; Bouchard, Frédéric; Edwards, Thomas W.D.; Farquharson, Nicole; Hall, Roland I.; McDonald, Ian; Narancic, Biljana; Ouimet, Chantal; Pienitz, Reinhard; Tondu, Jana; White, Hilary

    2017-01-01

    Numerous studies utilizing remote sensing imagery and other methods have documented that thermokarst lakes are undergoing varied hydrological transitions in response to recent climate changes, from surface area expansion to drainage and evaporative desiccation. Here, we provide a synthesis of hydrological conditions for 376 lakes of mainly thermokarst origin across high-latitude North America. We assemble surface water isotope compositions measured during the past decade at five lake-rich landscapes including Arctic Coastal Plain (Alaska), Yukon Flats (Alaska), Old Crow Flats (Yukon), northwestern Hudson Bay Lowlands (Manitoba), and Nunavik (Quebec). These landscapes represent the broad range of thermokarst environments by spanning gradients in meteorological, permafrost, and vegetation conditions. An isotope framework was established based on flux-weighted long-term averages of meteorological conditions for each lake to quantify water balance metrics. The isotope composition of source water and evaporation-to-inflow ratio for each lake were determined, and the results demonstrated a substantial array of regional and subregional diversity of lake hydrological conditions. Controls on lake water balance and how these vary among the five landscapes and with differing environmental drivers are assessed. Findings reveal that lakes in the Hudson Bay Lowlands are most vulnerable to evaporative desiccation, whereas those in Nunavik are most resilient. However, we also identify the complexity in predicting hydrological responses of these thermokarst landscapes to future climate change.

  8. Spectral feature measurements and analyses of the East Lake

    NASA Astrophysics Data System (ADS)

    Fang, Shenghui; Zhou, Yuan; Zhu, Wu

    2005-10-01

    It is one of basis of water color remote sensing to investigate the method to obtain and analyze the spectral features of the water bodies. This paper concerns the above-water method for the spectral measurements of inland water. A series of experiments were taken in areas of the East Lake with the EPP2000CCD radiometer, and the geometry attitude of the observation and the method of the elimination of the noise of the water Signals will be discussed. The method of the above-water spectral measurements was studied from the point of view of error source. On the basis of the experiments of the water depth and the observing direction form the sun and surface, it is suggested to remove the radiances of the whitecaps, surface-reflected sun glint and skylight which have not the spectral features of water from the lake surface by specialized observing attitude and data processing. At last, a suit of methods is concluded for the water body of the East Lake in measuring and analyzing the spectral features from above-water.

  9. The lacustrine carbon cycle as illuminated by the waters and sediments of two hydrologically distinct headwater lakes in North-Central Minnesota, U.S.A

    USGS Publications Warehouse

    Dean, W.E.; Schwalb, A.

    2002-01-01

    The accumulation rates of CaCO3 and organic carbon (OC) in lake sediments are delicately balanced between production in the epilimnion and destruction in the hypolimnion. The cycling of these two forms of carbon makes a "carbon pump" that greatly affects the biogeochemical cycles of other elements. To further understand these biogeochemical dynamics, the lakes, streams, and wetlands of the Shingobee River headwater area of north-central Minnesota have been subjected to intensive hydrologic and biogeochemical studies. Williams Lake, situated close to the highest point in the regional flow system, is hydrologically closed, with no surface inlet or outlet, and ground water and precipitation as the only sources of water. Shingobee Lake, situated at the lowest point in the regional flow system, has the Shingobee River as an inlet and outlet. The surface waters of both lakes are oversaturated, and the bottom waters undersaturated, with respect to CaCO3 during the summer. The small amount of CaCO3 that is precipitated in the epilimnion of Williams Lake during the summer is dissolved in the undersaturated hypolimnion and sediments with the result that no CaCO3 is incorporated into the profundal surface sediments. Because of the high phytoplankton productivity of Shingobee Lake, sufficient CaCO3 is produced in the epilimnion that large amounts survive the corrosive hypolimnion and sediments, and an average of 46 wt. % accumulates in surface sediments. Another consequence of higher phytoplankton productivity in Shingobee Lake is that the hypolimnion becomes oxygen deficient within a month after overturn in both the spring and fall. Because of reducing conditions that develop in the hypolimnion of Shingobee Lake, high concentrations of dissolved Fe and Mn accumulate there during summer stratification. Precipitation of Fe and Mn oxyhydroxides during periods of fall and spring overturn results in high concentrations of Fe and Mn in surface sediments. In Williams Lake, high concentrations of Fe and Mn do not build up in the hypolimnion. The concentration of CaCO3 is about 80 wt. % in lower Holocene sediments of both lakes. The lower Holocene sediments in both lakes also contain high concentrations of Fe and Mn, and the lower Holocene sediments of Shingobee are laminated. The waters of both lakes had identical values of ??13C and ??18O during the early Holocene, but the waters of Williams Lake "evolved" during the early Holocene, increasing about 10??? in both ??13C and ??18O. Deposits of lacustrine marl occur as much as seven meters above the present elevation of Williams Lake, the highest of the two lakes. Taken together, these observations suggest that the lakes were once connected to form a larger lake called Lake Willobee with a hypolimnion that was anoxic, at least seasonally.

  10. Eolian transport, saline lake basins, and groundwater solutes

    USGS Publications Warehouse

    Wood, Warren W.; Sanford, Ward E.

    1995-01-01

    Eolian processes associated with saline lakes are shown to be important in determining solute concentration in groundwater in arid and semiarid areas. Steady state mass balance analyses of chloride in the groundwater at Double Lakes, a saline lake basin in the southern High Plains of Texas, United States, suggest that approximately 4.5 × 105 kg of chloride is removed from the relatively small (4.7 km2) basin floor each year by deflation. This mass enters the groundwater down the wind gradient from the lake, degrading the water quality. The estimates of mass transport were independently determined by evaluation of solutes in the unsaturated zone and by solute mass balance calculations of groundwater flux. Transport of salts from the lake was confirmed over a short term (2 years) by strategically placed dust collectors. Results consistent with those at Double Lake were obtained from dune surfaces collected upwind and downwind from a sabkha near the city of Abu Dhabi in the United Arab Emirates. The eolian transport process provides an explanation of the degraded groundwater quality associated with the 30–40 saline lake basins on the southern half of the southern High Plains of Texas and New Mexico and in many other arid and semiarid areas.

  11. Lake Mackay, Australia

    NASA Image and Video Library

    2017-12-08

    Lake Mackay is the largest of hundreds of ephemeral lakes scattered throughout Western Australia and the Northern Territory, and is the second largest lake in Australia. The darker areas indicate some form of desert vegetation or algae, moisture within the soils, and lowest elevations where water pools. The image was acquired on September 19, 2010 and covers an area of 27 x 41 km. With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on Terra. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate, Washington, D.C. More information about ASTER is available at asterweb.jpl.nasa.gov/. Image Credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

  12. A GUIDE TO AERATION/CIRCULATION TECHNIQUES FOR ...

    EPA Pesticide Factsheets

    The application of aeration/circulation techniques to lakes are reviewed from a theoretical and practical viewpoint. The effect of destratification on algal production is related to the mixed depth with the use of a mathematical model. Procedures are given to determine air required to mix lakes of different sizes and shapes. It was found that approximately 30 scfm of air per 1,000,000 sq ft of lake surface area can be used. Hypolimnetic aeration systems that have been used are described in detail. Procedures for design are given.

  13. Ground-water hydrology of the Chad Basin in Bornu and Dikwa Emirates, northeastern Nigeria, with special emphasis on the flow life of the artesian system

    USGS Publications Warehouse

    Miller, Raymond E.; Johnston, R.H.; Olowu, J.A.I.; Uzoma, J.U.

    1968-01-01

    Bornu and Dikwa Emirates lie in the Nigerian sector of the Chad Basin, a vast region of interior drainage encompassing about 600,000 square miles of north-central Africa. The report area includes about 25,000 square miles of the basin that lie in Nigeria. Most of the area is a featureless plain that slopes gently northeast and east from the uplands of central Nigeria towards Lake Chad. On its eastern side the lake has one surface outlet which overflows only during exceptionally high stages of the lake. This outlet spills into the channel of Bahr al Ghazal, which in turn drains into the Bod616 depression. Because the lake is shallow, the shoreline fluctuates markedly with high and low stages corresponding to the wet and dry seasons. The semiarid climate of Bornu and Dikwa Emirates is characterized by a long dry season and a short wet season that correspond to seasonal winds. Annual rainfall ranges from 15 inches in the northern part of the area to 32 inches in the southern. The Chad Basin in Dikwa and Bornu Emirates is underlain by interbedded sand and clay, collectively termed the Chad Formation. These alluvial and lactustrine sediments were deposited in or near Lake Chad whet it occupied a much greater area during Pliocene and Pleistocene time. The Chad Formation has a very slight primary dip in the direction of Lake Chad and conforms to the gentle slope of land surface. The known thickness of the formation ranges from a few feet where it overlies bedrock on the periphery of the basin to at least 1,800 feet at Maiduguri; however, its total thickness probably exceeds 2,000 feet in the central part of the basin. Three water-bearing units termed upper, middle, and lower zones occur within the Chad Formation. The upper zone yields water to numerous dug wells throughout the rural areas and also is .the major source of the Maiduguri municipal water .supply. The middle zone yields water from flowing artesian boreholes that have heads ranging from a few feet to 70 feet above land surface throughout a 13,000 square-mile area of the basin in Nigeria. The lower zone also yields water from flowing boreholes ; however, its areal extent has not been proved beyond the environs of Maiduguri. The present investigation is concerned primarily with the middle zone, which is the source of water for some 190 flowing boreholes used as little-watering points in the Nigerian sector of the Chad Basin. The thickness of loads of waterbearing sand in the middle zone ranges from less than 1 foot to 200 feet, and the artesian head ranges from land surface at Maiduguri to 70 feet above land surface at Lake Chad. The depth to the top of the middle zone in the area of flowing boreholes ranges from 500 to 1,250 feet below land surface. The waterbearing properties of the middle zone differ greatly from place to place. Also, the yields of individual flowing boreholes generally range from 50 to 20,000 imperial gallons per hour (gph). On the basis of water availability, the middle zone can be divided as follows : Areas of high-, moderate-, and low-yield artesian aquifer ; areas of low- and moderate-yield subartesian aquifer ; and an area where the yields from boreholes are insignificant or the aquifer is missing. Recommended maximum rates of long-term withdrawal from individual boreholes for the three artesian areas range from 100 to 5,000 gph with boreholes spaced 5 to 10 miles apart. By limiting flows to the recommended maximum rates, the boreholes should continue to flow for at least 30 years. The present average use per borehole (265 gph in 1965) is considerably less than the recommended maximum rates. Recharge to the upper zone occurs in significant but as yet unmeasured quantities, mostly in the vicinity of the major streams. Apparently, however, no significant amount of recharge reaches the middle zone from the Upper zone. Although the middle zone is, in effect, being 'mined' by existing flowing wells, the present (1965) rate of withdrawal i

  14. Flexural-response of the McMurdo Ice Shelf to surface lake filling and drainage

    NASA Astrophysics Data System (ADS)

    Banwell, A. F.; MacAyeal, D. R.; Willis, I.; Macdonald, G. J.; Goodsell, B.

    2017-12-01

    Antarctic ice-shelf instability and break-up, as exhibited by the Larsen B ice shelf in 2002, remains one of the most difficult glaciological processes to observe directly. It is, however, vital to do so because ice-shelf breakup has the potential to influence the buttressing controls on inland ice discharge, and thus to affect sea level. Several mechanisms enabling Larsen B style breakup have previously been proposed, including the ability of surface lakes to introduce ice-shelf fractures when they fill and drain. During the austral summer of 2016/2017, we monitored the filling and draining of four surface lakes on the McMurdo Ice Shelf, Antarctica, and the effect of these processes on ice-shelf flexure. Water-depth data from pressure sensors reveal that two lakes filled to >2 m in depth and subsequently drained over multiple week timescales, which had a simultaneous effect on vertical ice deflection in the area. Differential GPS data from 12 receivers over three months show that vertical deflection varies as a function of distance from the maximum load change (i.e. at the lake centre). Using remote sensing techniques applied to both Landsat 8 and Worldview imagery, we also quantify the meltwater volume in these two lakes through the melt season, which, together with the vertical deflection data, are used to constrain key flexural parameter values in numerical models of ice-shelf flexure.

  15. Physical, chemical, and biological data for detailed study of the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge, west-central Montana, 1990-92, with selected data for 1987-89

    USGS Publications Warehouse

    Lambing, J.H.; Nimick, D.A.; Knapton, J.R.; Palawski, D.U.

    1994-01-01

    Physical chemical, and biological data were collected in the lower Sun River area of west-central Montana during 1990-92 as part of a U.S. Department of the Interior detailed study of the extent, magnitude, sources, and potential biological impacts of contaminants associated with irrigation drainage. Physical and chemical data were collected from areas within and near the Sun River Irrigation Project and from wetland areas receiving irrigation drainage. Biological data were collected from areas in and near Freezout Lake Wildlife Management Area and Benton Lake National Wildlife Refuge. Additional biological data were collected previously during 1987-89 as part of a U.S. Fish and Wildlife Service program. This report presents data for selenium and other potentially toxic constituents in solid-phase, water, and biological media. Data consist of concentrations of major and trace elements in soil and drill cores; concen- trations of major ions, nutrients, and trace elements in ground water and surface water; and trace-element concentrations in bottom sediment and biological tissue. Hydrogeologic data for domestic and test wells and daily streamflow data for selected sites also are included.

  16. Water quality in the vicinity of Mosquito Creek Lake, Trumbull County, Ohio, in relation of the chemistry of locally occurring oil, natural gas, and brine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barton, G.J.; Burruss, R.C.; Ryder, R.T.

    1998-12-31

    The purpose of this report is to describe current water quality and the chemistry of oil, natural gas, and brine in the Mosquito Creek Lake area. Additionally, these data are used to characterize water quality in the Mosquito Creek Lake area in relation to past oil and natural gas well drilling and production. To meet the overall objective, several goals for this investigation were established. These include (1) collect water-quality and subsurface-gas data from shallow sediments and rock that can be used for future evaluation of possible effects of oil and natural gas well drilling and production on water supplies,more » (2) characterize current surface-water and ground-water quality as it relates to the natural occurrence and (or) release of oil, gas, and brine (3) sample and chemically characterize the oil in the shallow Mecca Oil Pool, gas from the Berea and Cussewago Sandstone aquifers, and the oil, gas, and brine from the Clinton sandstone, and (4) identify areas where aquifers are vulnerable to contamination from surface spills at oil and natural gas drilling and production sites.« less

  17. PeRL: a circum-Arctic Permafrost Region Pond and Lake database

    DOE PAGES

    Muster, Sina; Roth, Kurt; Langer, Moritz; ...

    2017-06-06

    Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1.0 × 10 4 m 2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002–2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 withmore » a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1.4 × 10 6 km 2 across the Arctic, about 17 % of the Arctic lowland ( < 300 m a.s.l.) land surface area. PeRL waterbodies with sizes of 1.0 ×10 6 m 2 down to 1.0 ×10 2 m 2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1.0 ×10 to 9.4 × 10 1 km –2. Ponds are the dominant waterbody type by number in all landscapes representing 45–99 % of the total waterbody number. In conclusion, the implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands.« less

  18. PeRL: a circum-Arctic Permafrost Region Pond and Lake database

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Muster, Sina; Roth, Kurt; Langer, Moritz

    Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1.0 × 10 4 m 2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002–2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 withmore » a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1.4 × 10 6 km 2 across the Arctic, about 17 % of the Arctic lowland ( < 300 m a.s.l.) land surface area. PeRL waterbodies with sizes of 1.0 ×10 6 m 2 down to 1.0 ×10 2 m 2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1.0 ×10 to 9.4 × 10 1 km –2. Ponds are the dominant waterbody type by number in all landscapes representing 45–99 % of the total waterbody number. In conclusion, the implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands.« less

  19. Effects of acidic deposition on in-lake phosphorus availability: a lesson from lakes recovering from acidification.

    PubMed

    Kopáček, Jiří; Hejzlar, Josef; Kaňa, Jiří; Norton, Stephen A; Stuchlík, Evžen

    2015-03-03

    Lake water concentrations of phosphorus (P) recently increased in some mountain areas due to elevated atmospheric input of P rich dust. We show that increasing P concentrations also occur during stable atmospheric P inputs in central European alpine lakes recovering from atmospheric acidification. The elevated P availability in the lakes results from (1) increasing terrestrial export of P accompanying elevated leaching of dissolved organic carbon and decreasing phosphate-adsorption ability of soils due to their increasing pH, and (2) decreasing in-lake P immobilization by aluminum (Al) hydroxide due to decreasing leaching of ionic Al from the recovering soils. The P availability in the recovering lakes is modified by the extent of soil acidification, soil composition, and proportion of till and meadow soils in the catchment. These mechanisms explain several conflicting observations of the acid rain effects on surface water P concentrations.

  20. PeRL: A circum-Arctic Permafrost Region Pond and Lake database

    USGS Publications Warehouse

    Muster, Sina; Roth, Kurt; Langer, Moritz; Lange, Stephan; Cresto Aleina, Fabio; Bartsch, Annett; Morgenstern, Anne; Grosse, Guido; Jones, Benjamin M.; Sannel, A.B.K.; Sjoberg, Ylva; Gunther, Frank; Andresen, Christian; Veremeeva, Alexandra; Lindgren, Prajna R.; Bouchard, Frédéric; Lara, Mark J.; Fortier, Daniel; Charbonneau, Simon; Virtanen, Tarmo A.; Hugelius, Gustaf; Palmtag, J.; Siewert, Matthias B.; Riley, William J.; Koven, Charles; Boike, Julia

    2017-01-01

    Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002–2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( <  300 m a.s.l.) land surface area. PeRL waterbodies with sizes of 1. 0 × 106 m2 down to 1. 0 × 102 m2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1. 0 × 10 to 9. 4 × 101 km−2. Ponds are the dominant waterbody type by number in all landscapes representing 45–99 % of the total waterbody number. The implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands. Waterbody maps, study area boundaries, and maps of regional permafrost landscapes including detailed metadata are available at https://doi.pangaea.de/10.1594/PANGAEA.868349.

  1. A coupled lake-atmosphere model (CLAM) and its application to Lake Kinneret

    NASA Astrophysics Data System (ADS)

    Pan, Hai

    1999-08-01

    Kinneret is a 166-km2 lake located in Northern Israel, in the central part of the Jordan Valley, a corridor running from north to south, between the Galilee hills in the west and the Golan Heights in the east. Both the Galilee hills and the Golan Heights reach an elevation of about 400 m above mean sea level (MSL), and the lake is about -210 m (MSL). North of the lake is the mountainous area of the Hermon, culminating at about 2800 m (MSL). About 120 km south of it is the Dead Sea, which is about -410 m (MSL), and about 45 km west of it is the Mediterranean Sea. The complexity of the terrain, combined with relatively arid soil and various ground covers surrounding the lake, results in a very complicated system of atmospheric and lake processes. To understand this system, especially the processes affecting the atmosphere and lake dynamics and thermodynamics, and their effects on Lake Kinneret evaporation, a coupled lake-atmosphere model (CLAM) was developed and applied to the lake region. The CLAM is based on the Regional Atmospheric Modeling System (RAMS) and the oceanic S-coordinate Rutgers University Model (SCRUM). Energy, mass, and momentum are conserved at the interface between the atmosphere and the lake, and appropriate balance equations are applied there. In the atmospheric module, two nested grids are employed to simulate Northern Israel at a resolution of 4 x 4 km2, and the near-lake region at a resolution of 1 x 1 km 2. Synoptic conditions obtained from the National Meteorological Center (NMC) reanalysis are assimilated by the model. Soil moisture, which appears to have a significant impact on atmospheric circulation in this region, was transformed from the normalized difference vegetation index (NDVI). Observations collected during two summers above and inside the lake emphasize the good capability of CLAM to simulate surface fluxes and other microclimatic conditions, as well as lake temperature and currents. Although the lake is small (about 12-km wide and 22-km long), the micrometeorological conditions, lake currents and thermal structure, and the lake-surface heat fluxes vary spatially very significantly, even on a daily basis. It is found that the daily-mean wind curl, which is predominantly determined by the passage of the Mediterranean Sea breeze (MSB) over the lake, is mostly responsible for the gyres in the lake. The thermocline oscillation in the lake is mainly controlled by the surface elevation set up by the time-dependent winds. The intense MSB over the lake in the late afternoon pushes the heated surface water eastward, forces the deep, cooler water to be advected westward, and creates strong mixing in the lake, resulting in a higher temperature off the eastern shore and a lower temperature off the western shore. The variation of lake-surface temperature not only directly affects the atmospheric processes over the lake, but it also changes the wind field, which then influences hydrodynamic processes in the lake. An analytical model of the flow response to spatial variation of atmospheric cooling in coastal ocean was also developed in this study. This model is used to explain the contribution of the spatial variation of latent heat flux to the circulation in Lake Kinneret, and also the cyclonic flow, which is observed in many lakes and semi-enclosed coastal oceans.

  2. Eruptive behavior of the Marum/Mbwelesu lava lake, Vanuatu and comparisons with lava lakes on Earth and Io

    NASA Astrophysics Data System (ADS)

    Radebaugh, Jani; Lopes, Rosaly M.; Howell, Robert R.; Lorenz, Ralph D.; Turtle, Elizabeth P.

    2016-08-01

    Observations from field remote sensing of the morphology, kinematics and temperature of the Marum/Mbwelesu lava lake in the Vanuatu archipelago in 2014 reveal a highly active, vigorously erupting lava lake. Active degassing and fountaining observed at the 50 m lava lake led to large areas of fully exposed lavas and rapid ( 5 m/s) movement of lava from the centers of upwelling outwards to the lake margins. These rapid lava speeds precluded the formation of thick crust; there was never more than 30% non-translucent crust. The lava lake was observed with several portable, handheld, low-cost, near-infrared imagers, all of which measured temperatures near 1000 °C and one as high as 1022 °C, consistent with basaltic temperatures. Fine-scale structure in the lava fountains and cooled crust was visible in the near infrared at 5 cm/pixel from 300 m above the lake surface. The temperature distribution across the lake surface is much broader than at more quiescent lava lakes, peaking 850 °C, and is attributed to the highly exposed nature of the rapidly circulating lake. This lava lake has many characteristics in common with other active lava lakes, such as Erta Ale in Ethiopia, being confined, persistent and high-temperature; however it was much more active than is typical for Erta Ale, which often has > 90% crust. Furthermore, it is a good analogue for the persistent, high-temperature lava lakes contained within volcanic depressions on Jupiter's moon Io, such as Pele, also believed from spacecraft and ground-based observations to exhibit similar behavior of gas emission, rapid overturn and fountaining.

  3. Hydrology and simulation of ground-water flow, Lake Point, Tooele County, Utah

    USGS Publications Warehouse

    Brooks, Lynette E.

    2006-01-01

    Water for new residential development in Lake Point, Utah may be supplied by public-supply wells completed in consolidated rock on the east side of Lake Point. Ground-water flow models were developed to help understand the effect the proposed withdrawal will have on water levels, flowing-well discharge, spring discharge, and ground-water quality in the study area. This report documents the conceptual and numerical ground-water flow models for the Lake Point area.The ground-water system in the Lake Point area receives recharge from local precipitation and irrigation, and from ground-water inflow from southwest of the area. Ground water discharges mostly to springs. Discharge also occurs to evapotranspiration, wells, and Great Salt Lake. Even though ground water discharges to Great Salt Lake, dense salt water from the lake intrudes under the less-dense ground water and forms a salt-water wedge under the valley. This salt water is responsible for some of the high dissolved-solids concentrations measured in ground water in Lake Point.A steady-state MODFLOW-2000 ground-water model of Tooele Valley adequately simulates water levels, ground-water discharge, and ground-water flow direction observed in Lake Point in 1969 and 2002. Simulating an additional 1,650 acre-feet per year withdrawal from wells causes a maximum projected drawdown of about 550 feet in consolidated rock near the simulated wells and drawdown exceeding 80 feet in an area encompassing most of the Oquirrh Mountains east of Lake Point. Drawdown in most of Lake Point ranges from 2 to 10 ft, but increases to more than 40 feet in the areas proposed for residential development. Discharge to Factory Springs, flowing wells, evapotranspiration, and Great Salt Lake is decreased by about 1,100 acre-feet per year (23 percent).The U.S. Geological Survey SUTRA variable-density ground-water-flow model generates a reasonable approximation of 2002 dissolved-solids concentration when simulating 2002 withdrawals. At most locations with measured dissolved-solids concentration in excess of 1,000 milligrams per liter, the model simulates salt-water intrusion with similar concentrations.Simulating an additional 1,650 acre-feet per year withdrawal increased simulated dissolved-solids concentration by 200 to 1,000 milligrams per liter throughout much of Lake Point and near Fac­tory Springs at a depth of about 250 to 300 feet below land surface. The increase in dissolved-solids concentration with increased withdrawals is greater at a depth of about 700 to 800 feet and exceeds 1,000 milligrams per liter throughout most of Lake Point. At the north end of Lake Point, increases exceed 10,000 milligrams per liter.

  4. Geology and water resources of Winnebago County, Wisconsin

    USGS Publications Warehouse

    Olcott, Perry C.

    1966-01-01

    Sources or water in Winnebago County include surface water from the Fox and Wolf Rivers and their associated lakes, and ground water from sandstone, dolomite, and sand and gravel deposits. Surface water is hard and generally requires treatment, but is then suitable for municipal and most industrial uses. Pollution is only a local problem in the lakes and rivers, but algae are present in most of the lakes. Ground water in Winnebago County is hard to very hard, and dissolved iron is a problem in a large area of the county. A saline-water zone borders the eastern edge of the county and underlies the areas of concentrated pumpage at Neenah-Menasha and Oshkosh. A thick, southeastward-dipping sandstone aquifer, yielding as much as 1,000 gallons per minute to municipal and industrial wells, underlies Winnebago County. A dolomite aquifer in the eastern and southern part of the county yields as much as 50 gallons per minute to wells. Sand and gravel layers and lenses in preglacial bedrock channels, in northwestern Winnebago County and in the upper Fox River valley, yield as much as 50 gallons per minute to wells. Present water problems in the county include algae and local pollution in the Lake Winnebago Pool, iron in water from the sandstone aquifer, and saline ground Water in the eastern part of the county. Potential problems include rapid decline of water levels because of interference between closely spaced wells, migration of saline ground water toward areas of pumping, surface-water pollution from inadequate sewage and industrial-waste process plants, and ground-water pollution in dolomite formations. Development of the water resources of the county should follow a comprehensive plan which takes into consideration all aspects of water use. Dispersal of wells, especially extending toward the west from the heavily pumped Neenah-Menasha and Oshkosh areas, is recommended to reduce water-level declines and to avoid saline water. Supplemental use of ground water is recmmended for municipal expansion of water facilities and to reduce the algae treatment problem of water from the Lake Winnebago Pool.

  5. Assessment of the Distribution, Sources and Potential Ecological Risk of Heavy Metals in the Dry Surface Sediment of Aibi Lake in Northwest China

    PubMed Central

    Abuduwaili, Jilili; Zhang, Zhao yong; Jiang, Feng qing

    2015-01-01

    The distribution, sources and potential ecological risk of heavy metals in the sediment of lakes in eastern China and other areas of the world that have undergone rapid economic development have been widely researched by scholars. However, this is not true for heavy metals in the sediment of rump lakes in the arid regions of China and world-wide. Because of this, we chose Aibi Lake to serve as a typical rump lake in an oasis in an arid area in northwest China for our study. Sediment samples were collected from the lake and then the quantities of the heavy metals Pb, Ni, Cd, Cu, Zn, Hg and Cr were measured. Then using a variety of statistical methods, we analyzed the distribution, sources, pollution status and the potential ecological risk of these metals. The results show that: (1) The amounts of the seven heavy metals all fell within the Second Soil National Standard, but the average and maximum values were all higher than the background values of Xinjiang in northwest China. (2) Multivariate statistical analysis determined that the Cd, Pb, Hg and Zn in the sediment were mainly derived from man-sources, and Cu, Ni, and Cr were mainly from the natural geological background. (3) Enrichment factor analysis and the geo-accumulation index evaluation method show that Cd, Hg and Pb in the surface sediment of the Aibi Lake were at low and partial pollution levels, while Zn, Cr, Ni and Cu were at no and low pollution levels. (4) Calculation of the potential ecological hazards index found that, among the seven tested heavy metals, Cd, Hg and Pb were the main potential ecological risk factors, and the contribution of each was 42.6%, 28.6%, and 24.0%, respectively. Cd is the main potential ecological risk factor, followed by Hg and Pb. This work revealed that recent economic development of the Aibi Lake Basin has negatively influenced the accumulation of heavy metals in the sediments of the lake, and, therefore, we should pay increasing attention to this problem and take effective measures to protect the ecology of the Aibi Lake Basin. This work can provide a scientific basis for an early warning of heavy metal pollution and for protection of the environment. Furthermore, it can serve as a reference when creating policies for the economic development in Aibi Lake Basin and environmental protection of rump lakes in arid regions of northwest China and other areas of the world. PMID:25781032

  6. Foreseen hydrological changes drive efforts to formulate water balance improvement measures as part of the management options of adaptation at Lake Balaton, Hungary

    NASA Astrophysics Data System (ADS)

    Molnar, Gabor; Kutics, Karoly

    2013-04-01

    Located in Western Hungary, Lake Balaton (LB) is one of the shallowest large lakes of the world. The catchment area including the lake is 5775 km2, only 10 times more than the lake surface area of 593 km2. This relatively small catchment area and the relatively dry climate results in high vulnerability of the lake water budget to any hydro-meteorological changes. Due to the combined effects of planned water quality protection measures (refer to adjoining article on LB water quality) water quality was not as serious a concern over the last 15 years. However, a new and potentially more damaging threat, decreasing water level started to emerge in 2000. The natural water budget was negative half of the time, i.e. 6 years in the last 12 years. It hadn't occurred in the previous 80 years, since 1921, the year from which detailed meteorological data on the area are available. This new phenomenon raised and continues to raise serious sustainability concerns in the Lake Balaton area requiring better understanding of climatic changes and their foreseen impacts on hydrological and ecological processes that would lead decision makers to formulate the appropriate vulnerability and adaptation policies. Based on the common methodologies of the EULAKES project, present state of the hydrological conditions was analyzed as well as qualitative vulnerability assessment carried out to the area. Using the climate scenarios developed by the project partner Austrian Institute of Technology, calculations on water budget changes was possible. It is estimated that by the middle of the 21st century the lake will experience a drastic drop in the inflow and, accompanied by the increased evaporation, it is likely that years without outflow and serious drops in water-level would occur. The increased frequency of unfavorable water deficit will cause not only ecological, but also socio-economic conflicts in the multipurpose usage of the lake. Therefore, a qualitative vulnerability assessment was completed with a similar methodology applied in partner lakes of the EULAKES project. Based on the assessment through a participatory process involving a broad group of stakeholders the possible management options were gathered and tested as the alternatives to improve the water balance of the lake.

  7. Expansion rate and geometry of floating vegetation mats on the margins of thermokarst lakes, northern Seward Peninsula, Alaska, USA

    USGS Publications Warehouse

    Parsekian, A.D.; Jones, Benjamin M.; Jones, M.; Grosse, G.; Walter, Anthony K.M.; Slater, L.

    2011-01-01

    Investigations on the northern Seward Peninsula in Alaska identified zones of recent (<50years) permafrost collapse that led to the formation of floating vegetation mats along thermokarst lake margins. The occurrence of floating vegetation mat features indicates rapid degradation of near-surface permafrost and lake expansion. This paper reports on the recent expansion of these collapse features and their geometry is determined using geophysical and remote sensing measurements. The vegetation mats were observed to have an average thickness of 0.57m and petrophysical modeling indicated that gas content of 1.5-5% enabled floatation above the lake surface. Furthermore, geophysical investigation provides evidence that the mats form by thaw and subsidence of the underlying permafrost rather than terrestrialization. The temperature of the water below a vegetation mat was observed to remain above freezing late in the winter. Analysis of satellite and aerial imagery indicates that these features have expanded at maximum rates of 1-2myr-1 over a 56year period. Including the spatial coverage of floating 'thermokarst mats' increases estimates of lake area by as much as 4% in some lakes. ?? 2011 John Wiley & Sons, Ltd.

  8. ASTER measurement of supraglacial lakes in the Mount Everest region of the Himalaya

    USGS Publications Warehouse

    Wessels, R.L.; Kargel, J.S.; Kieffer, H.H.

    2002-01-01

    We demonstrate an application of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images to detect and monitor supraglacial lakes on glaciers in the Mount Everest region in Tibet (Xizang) and Nepal. ASTER offers powerful capabilities to monitor supraglacial lakes in terms of (1) surface area, growth and disappearance (spatial resolution = 15 m), (2) turbidity (15 m resolution), and (3) temperature (90 m resolution). Preliminary results show an overall similarity of supraglacial lakes on three glaciers. Lakes have widely varying turbidity as indicated by color in visible/near-infrared bands 1-3, the largest lakes being bright blue (highly turbid), cold (near 0??C) and hydrautically connected with other lakes and supraglacial streams, while small lakes are mostly dark blue (relatively clear water), warmer (>4??C), and appear hydrautically isolated. High levels of turbidity in supraglacial lakes indicate high rates of meltwater input from streams or erosion of ice cliffs, and thus are an indirect measure relating to the activity and hydraulic integration of the lake with respect to other lakes and streams in the glacier.

  9. Spatial and Temporal Variation of PATMOS-x AVHRR Lake Surface Temperatures in the Laurentian Great Lakes

    NASA Astrophysics Data System (ADS)

    White, C.; Heidinger, A. K.; Ackerman, S. A.; McIntyre, P. B.

    2017-12-01

    A thirty-four year lake surface water temperature (LSWT) time series over the North American Great Lakes was extracted from NOAA's Advanced Very High Resolution Radiometer (AVHRR) Global Area Coverage (GAC). The time series was cloud-cleared using the NOAA Pathfinder Atmospheres Extended (PATMOS-x) climate dataset and the Clouds from AVHRR Extended System (CLAVR-x) processing system, and was subsampled to a regular 0.05° grid. LSWT coefficients for each AVHRR platform were fit to NOAA National Data Buoy Center buoys with historical records spanning 1982 to 2016. Satellite to buoy matchups indicate an RMSE of 0.72 K for the entire time series across all five lakes. An empirically fit diurnal correction was applied to correct for orbital drift and varying observation times of NOAA-7,9,11,12,14-19, Metop-1 and Metop-2. Ordinary linear regression slopes on monthly mean LSWT show strong spatial heterogeneity in the long-term LSWT trends both within each lake and between lakes. Differences in long-term trends using nighttime only, daytime only, and both day and night are examined. Additionally, a coastal upwelling signal can be identified from the time series along with the indication of an earlier onset of spring stratification.

  10. Geochemical speciation and pollution assessment of heavy metals in surface sediments from Nansi Lake, China.

    PubMed

    Yang, Liyuan; Wang, Longfeng; Wang, Yunqian; Zhang, Wei

    2015-05-01

    Sixteen surface sediment samples were collected from Nansi Lake to analyze geochemical speciation of heavy metals including Cd, As, Pb, Cr, and Zn, assess their pollution level, and determine the spatial distribution of the non-residual fraction. Results showed that Cd had higher concentrations in water-soluble and exchangeable fractions. As and Pb were mainly observed as humic acid and reducible fractions among the non-residual fractions, while Cr and Zn were mostly locked up in a residual fraction. The mean pollution index (P i) values revealed that the lower lake generally had a higher enrichment degree than the upper lake. Cd (2.73) and As (2.05) were in moderate level of pollution, while the pollution of Pb (1.80), Cr (1.27), and Zn (1.02) appeared at low-level pollution. The calculated pollution load index (PLI) suggested the upper lake suffered from borderline moderate pollution, while the lower lake showed moderate to heavy pollution. Spatial principle component analysis showed that the first principal component (PC1) including Cd, As, and Pb could explain 56.18 % of the non-residual fraction. High values of PC1 were observed mostly in the southern part of Weishan Lake, which indicated greater bioavailability and toxicity of Cd, As, and Pb in this area.

  11. Characterizing the Frequency and Elevation of Rapid Drainage Events in West Greenland

    NASA Astrophysics Data System (ADS)

    Cooley, S.; Christoffersen, P.

    2016-12-01

    Rapid drainage of supraglacial lakes on the Greenland Ice Sheet is critical for the establishment of surface-to-bed hydrologic connections and the subsequent transfer of water from surface to bed. Yet, estimates of the number and spatial distribution of rapidly draining lakes vary widely due to limitations in the temporal frequency of image collection and obscureness by cloud. So far, no study has assessed the impact of these observation biases. In this study, we examine the frequency and elevation of rapidly draining lakes in central West Greenland, from 68°N to 72.6°N, and we make a robust statistical analysis to estimate more accurately the likelihood of lakes draining rapidly. Using MODIS imagery and a fully automated lake detection method, we map more than 500 supraglacial lakes per year over a 63000 km2 study area from 2000-2015. Through testing four different definitions of rapidly draining lakes from previously published studies, we find that the number of rapidly draining lakes varies from 3% to 38%. Logistic regression between rapid drainage events and image sampling frequency demonstrates that the number of rapid drainage events is strongly dependent on cloud-free observation percentage. We then develop three new drainage criteria and apply an observation bias correction that suggests a true rapid drainage probability between 36% and 45%, considerably higher than previous studies without bias assessment have reported. We find rapid-draining lakes are on average larger and disappear earlier than slow-draining lakes, and we also observe no elevation differences for the lakes detected as rapidly draining. We conclude a) that methodological problems in rapid drainage research caused by observation bias and varying detection methods have obscured large-scale rapid drainage characteristics and b) that the lack of evidence for an elevation limit on rapid drainage suggests surface-to-bed hydrologic connections may continue to propagate inland as climate warms.

  12. Distribution characteristics and ecological risk assessment of toxic heavy metals and metalloid in surface water of lakes in Daqing Heilongjiang Province, China.

    PubMed

    Wang, Xiaodi; Zang, Shuying

    2014-05-01

    It is necessary to estimate heavy metal concentrations and risk in surface water for understanding the heavy metal contaminations and for sustainable protection of ecosystems and human health. To investigate the anthropogenic contribution of heavy metal accumulation surrounding an industrial city in China, the concentrations of six heavy metals, including mercury (Hg), arsenic (As), chromium (Cr), lead (Pb), copper (Cu), and cadmium (Cd) were examined; from four different regions of Daqing in autumn 2011 and winter 2012. The results showed heavy metals distributed in the industrial area at concentrations relatively higher than those in other three areas, while concentrations in the farming area and the protected area were lower. The heavy metal concentrations of water bodies in all areas, except those for Hg and As, Cu, Pb and Cr were lower than the cutoff values for the Class I water quality that was set as the highest standard to protect the national nature reserves. While Hg and As of lakes in industry region had a higher level than those in the agriculture and landscape water, the lowest allowed. The concentrations of all the heavy metals in winter were higher than in the autumn. Cu had a higher ecological risks level to freshwater organisms. The discharge of urban sewage and industrial wastewater might be a major pollutant source, thus these sources should identified before remediation efforts. Efforts are needed to protect the lakes from pollution and also to reduce environmental health risks. This study and the valuable data will pave the way for future research on these Lakes in Daqing.

  13. Geological and geochemical investigations of uranium occurrences in the Arrastre Lake area of the Medicine Bow Mountains, Wyoming

    USGS Publications Warehouse

    Miller, W. Roger; Houston, R.S.; Karlstrom, K.E.; Hopkins, D.M.; Ficklin, W.H.

    1977-01-01

    Metasedimentary rocks of Precambrian X age in and near the Snowy Range wilderness study area of southeastern Wyoming are lithologically and chronologically similar to those on the north shore of Lake Huron in Canada. The rocks in Canada contain major deposits of uranium in quartz-pebble conglomerates near the base of the metasedimentary sequence. Similar conglomerates in the Deep Lake Formation in the Medicine Bow Mountains of southeastern Wyoming are slightly radioactive and may contain deposits of uranium and other valuable heavy metals. During the summer of 1976, a geological and geochemical pilot study was conducted in the vicinity of Arrastre Lake in the Medicine Bow Mountains to determine the most effective exploration methods for evaluating the uranium potential of the Snowy Range wilderness study area. The area around Arrastre Lake was selected because of the presence of a radioactive lens within a quartz-pebble conglomerate of the Deep Lake Formation. The results of the survey indicate possible uranium mineralization in the subsurface rocks of this formation. The radon content of the dilute waters of the area is much higher than can be accounted for by the uranium content of the surface rocks. Two sources for the high content of the radon are possible. In either case, the high values of radon obtained in this study are a positive indication of uranium mineralization in the subsurface rocks. The determination of the radon content of water samples is the recommended geochemical technique for uranium exploration in the area. The determination of uranium in water and in organic-rich bog material is also recommended.

  14. Classifying and monitoring water quality by use of satellite imagery

    NASA Technical Reports Server (NTRS)

    Scherz, J. P.; Crane, D. R.; Rogers, R. H.

    1976-01-01

    A technique is developed to eliminate the atmosphere and surface noise effects on Landsat signals of water bodies by manipulating the total signal from Landsat in such a way that only the volume reflectance is left as a residual. With the Landsat signal from a lake and the known volume reflectance for its clear water it is possible to eliminate the surface and atmospheric effects and have residual signals that are indicative only of the type and concentration of the material in other lakes. Laboratory values are more precise than field values because in the field one must contend with indirect skylight and wave action which can be removed in the laboratory. The volume reflectance of distilled water or a very clear lake approaching distilled water was determined in the laboratory by the use of the Bendix radiant power measuring instrument. The Bendix multispectral data analysis system provided a color categorized image of several hundred lakes in a Wisconsin area. These lakes were categorized for tannin and nontannin waters and for the degrees of algae, silt, weeds, and bottom effects present.

  15. Assimilating a decade of hydrometeorological ship measurements across the North American Great Lakes

    NASA Astrophysics Data System (ADS)

    Fries, K. J.; Kerkez, B.

    2015-12-01

    We use a decade of measurements made by the Volunteer Observing Ships (VOS) program on the North American Great Lakes to derive spatial estimates of over-lake air temperature, sea surface temperature, dewpoint, and wind speed. This Lagrangian data set, which annually comprises over 200,000 point observations from over 80,000 ship reports across a 244,000 square kilometer study area, is assimilated using a Gaussian Process machine learning algorithm. This algorithm classifies a model for each hydrometeorological variable using a combination of latitudes, longitudes, seasons of the year, as well as predictions made by the National Digital Forecast Database (NDFD) and Great Lakes Coastal Forecasting System (GLCFS) operational models. We show that our data-driven method significantly improves the spatial and temporal estimation of overlake hydrometeorological variables, while simultaneously providing uncertainty estimates that can be used to improve historical and future predictions on dense spatial and temporal scales. This method stands to improve the prediction of water levels on the Great Lakes, which comprise over 90% of America's surface fresh water, and impact the lives of millions of people living in the basin.

  16. Evolution and hazard analysis of high-mountain lakes in the Cordillera Vilcabamba (Southern Peru) from 1991 to 2014

    NASA Astrophysics Data System (ADS)

    Guardamino, Lucía; Drenkhan, Fabian

    2015-04-01

    In recent decades, glaciers in high-mountain regions have experienced unprecedented glacier retreat since the Little Ice Age (LIA). This development triggers the formation and growth of glacier lakes, which in combination with changes in glacier parameters might produce more frequent conditions for the occurrence of disasters, such as Glacier Lake Outburst Floods (GLOF). Facing such a scenario, the analysis of changing lake characteristics and identification of new glacier lakes are imperative in order to identify and reduce potential hazards and mitigate or prevent future disasters for adjacent human settlements. In this study, we present a multi-temporal analysis with Landsat TM 5 and OLI 8 images between 1991 and 2014 in the Cordillera Vilcabamba region (Southern Peru), a remote area with difficult access and climate and glaciological in-situ data scarcity. A semi-automatic model was developed using the band ratios Normalized Difference Snow Index (NDSI) and Normalized Difference Water Index (NDWI) in order to identify glacier and lake area changes. Results corroborate a strong glacier area reduction of about 51% from 1991 (200.3 km²) to 2014 (98.4 km²). At the same time, the number of lakes (total lake surface) has increased at an accelerated rate, from 0.77% (0.48%) in 1991 to 2.31% (2.49%) in 2014. In a multiple criteria analysis to identify potential hazards, 90 out of a total of 329 lakes in 2014 have been selected for further monitoring. Additionally, 29 population centers have been identified as highly exposed to lake related hazards from which 25 indicate a distance less than 1 km to an upstream lake and four are situated in a channel of potential debris flow. In these areas human risks are particularly high in view of a low HDI below Peru's average and hence pronounced vulnerability. We suggest more future research on measurements and monitoring of glacier and lake characteristics in these remote high-mountain regions, which include comprehensive risk studies linking climate-related hazards and human vulnerability and exposure.

  17. Characterizing anthropogenic impacts on two mid-altitude Himalayan lakes in the Western Himalaya: A look at shifts in water chemistry and phytoplankton communities

    NASA Astrophysics Data System (ADS)

    Marcus, T. S.; Tiwari, S.; Bhatt, J. P.; Pandit, M. K.; Varner, R. K.

    2017-12-01

    The Himalayan region is globally regarded for its natural mountain ecosystems but increased agricultural expansion and urbanization have resulted in greater nutrient loading in Himalayan water bodies causing widespread fish kills and shrinking lakes. Despite concerns for environmental degradation, lack of empirical investigations and quantitative data are major constraints in understanding these events. To determine the impact of human development on Himalayan lakes, we investigated Rewalsar, a spring-fed lake and Kareri a glacial-fed lake in the state of Himachal Pradesh. Rewalsar is surrounded by a rapidly growing town and agricultural fields while Kareri Lake is situated in a relatively remote area. Measurements were made in the spring periods of 2013 and 2016. Water samples were collected 1m below the lake surface and analyzed for major ions, nitrates, phosphates, DO, pH, temperature, turbidity, and TDS. Alagal samples were collected from each lake and species counted and identified using standard taxonomic literature. Statistical analysis was performed using PC-ORD. Results showed a significant change in water chemistry and phytoplankton communities with Rewalsar Lake showing an increase in pollutant tolerant algae over the sample period. Principle component analysis showed that the 2016 data from Kareri Lake had phytoplankton communities and chemical data resembling the urban lake of Rewalsar. Kareri Lake had the highest DO (10 mg/ml) while Rewalsar showed the lowest DO at 3 mg/ml in 2016, a decrease from 8 mg/ml in 2013. With a total oxygen demand (TOD) of 6.5 mg/ml in Rewalsar, the decreasing DO value is likely the cause of the increasing annual fish kills as reported by local governments. TDS measurements were highest in Rewalsar Lake compared to the TDS levels of Kareri, indicating a higher amount of surface runoff from the surrounding area in Rewalsar. Nitrate and phosphate levels also increased over this time period. Our multi-year investigation also shows that the abundance of Microcystis and other pollution indicating taxa is on the rise, suggesting progressive eutrophication of Rewalsar Lake emanating from anthropogenic impacts. Additionally, NMDS and partial least squares regression analysis provide support for potential acidification events in these fresh-water Himalayan water bodies.

  18. Hydrologic behaviour of the Lake of Monate (Italy): a parsimonious modelling strategy

    NASA Astrophysics Data System (ADS)

    Tomesani, Giulia; Soligno, Irene; Castellarin, Attilio; Baratti, Emanuele; Cervi, Federico; Montanari, Alberto

    2016-04-01

    The Lake of Monate (province of Varese, Northern Italy), is a unique example of ecosystem in equilibrium. The lake water quality is deemed excellent notwithstanding the intensive agricultural cultivation, industrial assets and mining activities characterising the surrounding areas. The lake has a true touristic vocation and is the only swimmable water body of the province of Varese, which counts several natural lakes. Lake of Monate has no tributary and its overall watershed area is equal to c.a. 6.6 km2 including the lake surface (i.e. 2.6 km2), of which 3.3 out of c.a. 4.0 km2 belong to the topographical watershed, while the remaining 0.7 km2 belong to the underground watershed. The latter is larger than the topographical watershed due to the presence of moraine formations on top of the limestone bedrock. The local administration recently promoted an intensive environmental monitoring campaign that aims to reach a better understanding of the hydrology of the lake and the subsurface water fluxes. The monitoring campaign started in October 2013 and, as a result, several meteoclimatic and hydrologic data have been collected up to now at daily and hourly timescales. Our study focuses on a preliminary representation of the hydrological behaviour of the lake through a modified version of HyMOD, a conceptual 5-parameter lumped rainfall-runoff model based on the probability-distributed soil storage capacity. The modified model is a semi-distributed application of HyMOD that uses the same five parameters of the original version and simulates the rainfall-runoff transformation for the whole lake watershed at daily time scale in terms of: direct precipitation on, and evaporation from, the lake surface; overall lake inflow, by separating the runoff component (topographic watershed) from the groundwater component (overall watershed); lake water-level oscillation; streamflow at the lake outlet. We used the first year of hydrometeorological observations as calibration data and the second year as validation data and we compared two calibration strategies which maximize two different objective functions: (1) Nash-Sutcliffe efficiency of simulated daily water-level fluctuations, NSE, and (2) linear correlation coefficient between daily series of simulated groundwater inflow and observed water table elevation multiplied by NSE. The validation exercise seems to point out the value of incorporating groundwater measurements for improving the reliability and robustness of the conceptual model.

  19. Using Snow Fences to Augument Fresh Water Supplies in Shallow Arctic Lakes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stuefer, Svetlana

    2013-03-31

    This project was funded by the U.S. Department of Energy, National Energy Technology Laboratory (NETL) to address environmental research questions specifically related to Alaska's oil and gas natural resources development. The focus of this project was on the environmental issues associated with allocation of water resources for construction of ice roads and ice pads. Earlier NETL projects showed that oil and gas exploration activities in the U.S. Arctic require large amounts of water for ice road and ice pad construction. Traditionally, lakes have been the source of freshwater for this purpose. The distinctive hydrological regime of northern lakes, caused bymore » the presence of ice cover and permafrost, exerts influence on lake water availability in winter. Lakes are covered with ice from October to June, and there is often no water recharge of lakes until snowmelt in early June. After snowmelt, water volumes in the lakes decrease throughout the summer, when water loss due to evaporation is considerably greater than water gained from rainfall. This balance switches in August, when air temperature drops, evaporation decreases, and rain (or snow) is more likely to occur. Some of the summer surface storage deficit in the active layer and surface water bodies (lakes, ponds, wetlands) is recharged during this time. However, if the surface storage deficit is not replenished (for example, precipitation in the fall is low and near‐surface soils are dry), lake recharge is directly affected, and water availability for the following winter is reduced. In this study, we used snow fences to augment fresh water supplies in shallow arctic lakes despite unfavorable natural conditions. We implemented snow‐control practices to enhance snowdrift accumulation (greater snow water equivalent), which led to increased meltwater production and an extended melting season that resulted in lake recharge despite low precipitation during the years of the experiment. For three years (2009, 2010, and 2011), we selected and monitored two lakes with similar hydrological regimes. Both lakes are located 30 miles south of Prudhoe Bay, Alaska, near Franklin Bluffs. One is an experimental lake, where we installed a snow fence; the other is a control lake, where the natural regime was preserved. The general approach was to compare the hydrologic response of the lake to the snowdrift during the summers of 2010 and 2011 against the baseline conditions in 2009. Highlights of the project included new data on snow transport rates on the Alaska North Slope, an evaluation of the experimental lake's hydrological response to snowdrift melt, and cost assessment of snowdrift‐generated water. High snow transport rates (0.49 kg/s/m) ensured that the snowdrift reached its equilibrium profile by winter's end. Generally, natural snowpack disappeared by the beginning of June in this area. In contrast, snow in the drift lasted through early July, supplying the experimental lake with snowmelt when water in other tundra lakes was decreasing. The experimental lake retained elevated water levels during the entire open‐water season. Comparison of lake water volumes during the experiment against the baseline year showed that, by the end of summer, the drift generated by the snow fence had increased lake water volume by at least 21-29%. We estimated water cost at 1.9 cents per gallon during the first year and 0.8 cents per gallon during the second year. This estimate depends on the cost of snow fence construction in remote arctic locations, which we assumed to be at $7.66 per square foot of snow fence frontal area. The snow fence technique was effective in augmenting the supply of lake water during summers 2010 and 2011 despite low rainfall during both summers. Snow fences are a simple, yet an effective, way to replenish tundra lakes with freshwater and increase water availability in winter. This research project was synergetic with the NETL project, "North Slope Decision Support System (NSDSS) for Water Resources Planning and Management." The results of these projects were implemented in the NSDSS model and added to the annual water budget. This implementation allows one to account for snowdrift contributions during ice road planning with the NSDSS and assists with mitigating those risks associated with potentially unfavorable climate and hydrological conditions (that is, surface storage deficit and/or low precipitation).« less

  20. Effects of exploitation, environmental changes, and new species on the fish habitats and resources of Lake Erie

    USGS Publications Warehouse

    Hartman, Wilbur L.

    1973-01-01

    No other lake as large as Lake Erie (surface area, 25,690 km2) has been subjected to such extensive changes in the drainage basin, the lake environment, and the fish populations over the last 150 years. Deforestation and prairie burning led to erosion of the watershed and siltation of valuable spawning grounds. Marsh spawning areas were drained. Lake-to-river spawning migrations of sturgeon, walleye, and other fishes were blocked by mill dams. Accelerated cultural nutrient loading increased total dissolved solids by nearly 50% (1920-70). Phosphate loading reached 469 metric tons per year by the 1950's and continued to increase. The biomass of phytoplankton increased 20-fold between 1919 and 1963. Oxygen demand for decomposition of these algae so degraded oxygen regimes in the western and central basins by the 1950's that the once abundant mayfly nymphs were destroyed and the central basin hypolimnion became anoxic. The sequence of disappearance or severe depletion of fish species was as follows: lake trout, sturgeon, lake herring, lake whitefish, sauger, blue pike, and walleye. Yellow perch are now declining. All resources were intensively exploited at one time or another. Lake trout suffered only this stress, but changes in the watershed significantly stressed sturgeon and lake whitefish. Degradation of the lake spawning grounds, benthos, and oxygen regimes culminated in severe stress by the 1950's on the remnants of the lake herring and lake whitefish, and on the sauger, blue pike, and walleye. Additional mortality may have been imposed on walleye and blue pike fry by predacious smelt that successfully colonized Lake Erie after first appearing in 1932. The cultural stresses, in the probable order of greatest to least net effects on the fish community of Lake Erie, appear to have been: (1) an intense, opportunistic, ineffectively controlled commercial fishery; (2) changes in the watershed, such as erosion and siltation of stream beds and inshore lake areas, and construction of dams in tributaries; (3) nutrient loading, destruction of biota, and reduction of dissolved oxygen; and (4) the competitive and predatory activities of invading species.

  1. The influence of changes in wind patterns on the areal extension of surface cyanobacterial blooms in a large shallow lake in China.

    PubMed

    Wu, Tingfeng; Qin, Boqiang; Brookes, Justin D; Shi, Kun; Zhu, Guangwei; Zhu, Mengyuan; Yan, Wenming; Wang, Zhen

    2015-06-15

    It has been hypothesized that climate change will induce the areal extension of cyanobacterial blooms. However, this hypothesis lacks field-based observation. In the present study both long-term historical data and short-term field measurement were used to identify the importance of changes in wind patterns on the cyanobacterial bloom in Lake Taihu (China), a large, shallow, eutrophic lake located in a subtropical zone. The cyanobacterial bloom mainly composed of Microcystis spp. recurred frequently throughout the year. The regression analysis of multi-year satellite image data extracted by the Floating Algae Index revealed that both the annual mean monthly maximum cyanobacterial bloom area (MMCBA) increased year by year from 2000 to 2011, while the contemporaneous cyanobacterial biomass showed no significant change. However, the correlation analysis shows that MMCBA was negatively correlated with wind speed. Our short-term field measurements indicated that the influence of wind on surface cyanobacterial blooms is that the Chlorophyll-a (Chla) concentration is fully mixing throughout the water column when the wind speed exceed 7 m s(-1). At lower wind speeds, there was vertical stratification of Chla with high surface concentrations and an increase in bloom area. The regression analysis of wind speed indicates that the climate has changed over the last decade. Lake Taihu has become increasingly calm, with the decrease of strong wind frequency between 2000 and 2011, corresponding to the increase in the MMCBA over time. Therefore, we conclude that changes in wind patterns related to climate change have favored the increase of cyanobacterial blooms in Lake Taihu. Copyright © 2015. Published by Elsevier B.V.

  2. Effects of surface-water and groundwater inflows and outflows on the hydrology of the Tsala Apopka Lake Basin in Citrus County, Florida

    USGS Publications Warehouse

    Sepúlveda, Nicasio; Fulkerson, Mark; Basso, Ron; Ryan, Patrick J.

    2018-05-21

    The U.S. Geological Survey, in cooperation with the Southwest Florida Water Management District, initiated a study to quantify the inflows and outflows in the Floral City, Inverness, and Hernando pools of the Tsala Apopka Lake Basin in Citrus County, Florida. This study assesses hydrologic changes in pool stages, groundwater levels, spring flows, and streamflows caused by the diversion of streamflow from the Withlacoochee River to the Tsala Apopka Lake Basin through water-control structures. A surface-water/groundwater flow model was developed using hydraulic parameters for lakes, streams, the unsaturated zone, and the underlying surficial and Upper Floridan aquifers estimated using an inverse modeling calibration technique. After calibration, the model was used to assess the relation between inflows and outflows in the Tsala Apopka Lake Basin and changes in pool stages.Simulation results using the calibrated surface-water/groundwater flow model showed that leakage rates from the pools to the Upper Floridan aquifer were largest at the deep lake cells and that these leakage rates to the Upper Floridan aquifer were the highest in the model area. Downward leakage to the Upper Floridan aquifer occurred beneath most of the extent of the Floral City, Inverness, and Hernando pools. These leakage rates depended on the lakebed leakance and the difference between lake stages and heads in the Upper Floridan aquifer. Leakage rates were higher for the Floral City pool than for the Inverness pool, and higher for the Inverness pool than for the Hernando pool. Lakebed leakance was higher for the Floral City pool than for the Hernando pool, and higher for the Hernando pool than for the Inverness pool.Simulation results showed that the average recharge rate to the surficial aquifer was 10.3 inches per year for the 2004 to 2012 simulation period. Areas that recharge the surficial aquifer covered about 86 percent of the model area. Simulations identified areas along segments of the Withlacoochee River and within land-surface depressions that receive water from the surficial aquifer. Recharge rates were largest in physiographic regions having a deep water table. Simulated heads in the Upper Floridan aquifer indicated the general flow directions in the active flow model area were from the northeast toward the southwest and then westward toward the coast, and from the southeast toward the northwest and then westward toward the coast, consistent with flow directions inferred from the estimated potentiometric surface map for May 2010. The largest inflow in the water budget of the Upper Floridan aquifer was downward leakage from the overlying hydrogeologic unit. The largest outflow in the water budget of the Upper Floridan aquifer was spring flow.The calibrated surface-water and groundwater flow model was used to simulate hydrologic scenarios that included changes in rainfall rates, projected increases in groundwater pumping rates for 2025 and 2035, no flow for the 2004–12 period through the eight water-control structures in the Tsala Apopka Lake Basin, and the removal of the Inglis Dam and the Inglis Bypass Spillway on Lake Rousseau. Scenario simulation results were compared to annual average calibrated water levels and flows from 2004 to 2012. Simulated declines in the Tsala Apopka Lake pool stages under the 10-percent lower rainfall scenario were about 0.8, 0.3, and 1.3 feet (ft) for the Floral City, Inverness, and Hernando pools, respectively. Simulated groundwater levels under the same scenario declined up to 5.4 ft in the surficial aquifer and up to 2.9 ft in the Upper Floridan aquifer. Under the projected increases in groundwater pumping rates for 2035 that represented an increase of 36 percent from average 2004 to 2012 pumping rates, the simulated declines in the Floral City, Inverness, and Hernando pool stages were, in downstream order, 0.02, 0.06, and 0.04 ft. The largest drawdown under the projected increases in groundwater pumping rates for 2035 was 2.1 ft in the surficial aquifer and about 1.8 ft in the Upper Floridan aquifer. A scenario of decreased rainfall by 10 percent caused greater declines in water levels and pool stages than projected increases in groundwater pumping rates. The simulation with no flow through the eight Tsala Apopka Lake water-control structures resulted in simulated declines in average pool stage of 1.8, 1.9, and 0.5 ft in the Floral City, Inverness, and Hernando pools, respectively. The simulated removal of the two water-control structures in Lake Rousseau caused flow to increase at Rainbow Springs by 28 cubic feet per second, an increase of 4.7 percent from the average calibrated flow for 2004 to 2012.

  3. Widespread occurrence and seasonal variation of pharmaceuticals in surface waters and municipal wastewater treatment plants in central Finland.

    PubMed

    Lindholm-Lehto, Petra C; Ahkola, Heidi S J; Knuutinen, Juha S; Herve, Sirpa H

    2016-04-01

    The presence of five selected pharmaceuticals, consisting of four anti-inflammatory drugs, diclofenac, ibuprofen, ketoprofen, naproxen, and an antiepileptic drug carbamazepine, was determined at four municipal wastewater treatment plants (WWTPs) and in the receiving waterway in central Finland. The samples were taken from influents and effluents of the WWTPs and from surface water of six locations along the water way, including northern Lake Päijänne. In addition, seasonal variation in the area was determined by comparing the concentrations in the winter and summer. The samples were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in the multiple reaction monitoring mode. The concentrations in the influents and effluents ranged from hundreds of nanogram per liter to microgram per liter while ranged from tens of nanogram per liter in northern parts of the waterway to hundreds of nanogram per liter in northern Lake Päijänne near the city area. In addition, the concentrations were higher in the winter compared to summer time in surface water due to decreased temperature and solar irradiation. On the other hand, higher concentrations of ibuprofen, ketoprofen, and naproxen were found in summer at the WWTPs, possibly due to seasonal variations in consumption. In conclusion, there are considerable amounts of pharmaceuticals not only in influents and effluents of the WWTPs but also in lake water along the waterway and in northern Lake Päijänne.

  4. Sublake geologic structure from high-resolution seismic-reflection data from four sinkhole lakes in the Lake Wales Ridge, Central Florida

    USGS Publications Warehouse

    Tihansky, A.B.; Arthur, J.D.; DeWitt, D.W.

    1996-01-01

    Seismic-reflection profiles from Lake Wales, Blue Lake, Lake Letta, and Lake Apthorp located along the Lake Wales Ridge in central Florida provide local detail within the regional hydrogeologic framework as described by litho- and hydrostratigraphic cross sections. Lakes located with the mantled karst region have long been considered to be sinkhole lakes, originating from subsidence activity. High-resolution seismic- reflection data confirm this origin for these four lakes. The geologic framework of the Lake Wales Ridge has proven to be a suitable geologic setting for continuous high-resolution seismic-reflection profiling in lakes; however, the nature of the lake-bottom sediments largely controls the quality of the seismic data. In lakes with significant organic-rich bottom deposits, interpretable record was limited to areas where organic deposits were minimal. In lakes with clean, sandy bottoms, the seismic-reflection methods were highly successful in obtaining data that can be correlated with sublake subsidence features. These techniques are useful in examining sublake geology and providing a better understanding of how confining units are affected by subsidence in a region where their continuity is of significant importance to local lake hydrology. Although local geologic control around each lake generally corresponds to the regional geologic framework, local deviations from regional geologic trends occur in sublake areas affected by subsidence activity. Each of the four lakes examined represents a unique set of geologic controls and provides some degree of structural evidence of subsidence activity. Sublake geologic structures identified include: (1) marginal lake sediments dipping into bathymetric lows, (2) lateral discontinuity of confining units including sags and breaches, (3) the disruption and reworking of overlying unconsolidated siliciclastic sediments as they subside into the underlying irregular limestone surface, and (4) sublake regions where confining units appear to remain intact and unaffected by nearby subsidence activity. Each lake likely is underlain by several piping features rather than one large subsidence feature.

  5. Historical and seasonal dynamics of phosphorus mobility in Sancha Lake of Southwest China's Sichuan Province.

    PubMed

    Jia, Binyang; Tang, Ya; Yang, Bo; Huang, Jen-How

    2017-01-01

    Phosphorus (P) fractionations in the surface sediment of Sancha Lake in China's southwestern Sichuan Province were examined to assess the potential P release at the water-sediment interface and to understand its seasonal (2009-2010) and historical dynamics (1989-2010) in the surface water. Elevated P concentrations were detected in the sediment at main reservoir inflow, south canal of the Dujiangyan irrigation network, and intensive cage fish farming area, accounting for 32 and 40% of current total P discharges. The highest total P concentration (11,200 μg P g -1 ) was observed in the upper sediment below intensive fish farming area with a specific enrichment of HCl-P (51% of total P) mainly from fish feeds and feces. These sediments had larger MgCl 2 -P pools with higher diffusive P fluxes (0.43-0.47 mg m -2  d -1 ) from surface sediment than those from other areas (0.25-0.42 mg m -2  d -1 ). The general small proportion of MgCl 2 -P (5.7-10%) and low diffusive P fluxes from surface sediment (<0.02% of sediment P storage (0-1 cm)) indicate low mobility and slow release of P from sediments. The sediment as an internal P source led to a 3-4-year lag for P concentration decrease in the surface water after restriction of anthropogenic P discharges since 2005. Thus, the peak P concentration in April and September could be explained as a combined effect of supplementing internal loading via reductive processes in sediments and seasonal water vertical circulation in the early spring and fall. Policy played a crucial role in reducing P inputs to the lake.

  6. On the influence of substrate morphology and surface area on phytofauna

    USGS Publications Warehouse

    Becerra-Munoz, S.; Schramm, H.L.

    2007-01-01

    The independent effects and interactions between substrate morphology and substrate surface area on invertebrate density or biomass colonizing artificial plant beds were assessed in a clear-water and a turbid playa lake in Castro County, Texas, USA. Total invertebrate density and biomass were consistently greater on filiform substrates than on laminar substrates with equivalent substrate surface areas. The relationship among treatments (substrates with different morphologies and surface areas) and response (invertebrate density or biomass) was assessed with equally spaced surface areas. Few statistically significant interactions between substrate morphology and surface area were detected, indicating that these factors were mostly independent from each other in their effect on colonizing invertebrates. Although infrequently, when substrate morphology and surface area were not independent, the effects of equally spaced changes in substrate surface area on the rate of change of phytofauna density or biomass per unit of substrate surface area were dependent upon substrate morphology. The absence of three-way interactions indicated that effects of substrate morphology and substrate area on phytofauna density or biomass were independent of environmental conditions outside and inside exclosures. ?? 2006 Springer Science+Business Media B.V.

  7. Lake-level stratigraphy and geochronology revisited at Lago (Lake) Cardiel, Argentina, and changes in the Southern Hemispheric Westerlies over the last 25 ka

    NASA Astrophysics Data System (ADS)

    Quade, J.; Kaplan, M. R.

    2017-12-01

    Paleoshorelines around Lago (Lake) Cardiel in southern Argentina (S48.9°, W71.3°; ∼275 m) record substantial changes in lake area over the past 25 ka. Our results combined with previous research show that during the last glacial maximum (or LGM, 23-21 ka), the lake stood at near modern levels, but had nearly dried up by ∼13 ka. Between 11.3 and 10.1 ka the lake reached its highest point (+54-58 m) and greatest extent in at least the last 40 ka. Lake levels dropped thereafter and experienced two lower-lake periods: 8.5-7.5 ka and 5-3.3 ka; and two higher-lake periods: 7.4-6 and ∼5.2 ka. In the last 3.5 ka, the lake has remained generally near or slightly above its present level. The depth and surface area of Lago Cardiel are controlled mainly by precipitation onto the lake and surrounding catchment, air and water temperature, and wind-speed related to local strength of the Southern Hemispheric Westerlies (SHW). Our lake-level reconstruction combined with evidence from other studies suggest that on average the core of the SHW was located well to the north (<45°S) of the Cardiel basin during the deep lake phase associated with the LGM, and was well to the south (>55°S?) during the hydrologic maximum of Cardiel in the early Holocene. The lower phases of the lake at 20.0-11.5, 8.5-7.5, and 5.0-3.3 ka generally correspond to cold conditions in other records, when we infer that the SHW were strongly focused around the latitudes of Cardiel at 49°S.

  8. Mitigation of Adverse Effects of Long Branch Lake Project upon the Archaeological Resources. Part 3.

    DTIC Science & Technology

    1986-01-01

    AREA & WORK UNIT NUMBERS Kirksville, Missouri 11. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE US Army Engineer District, Kansas City 1986 700...the clearing contract. Although most of the site lies above the level of the clearing, some material was collected from these areas . Material density...was very noor. The area was cleared under the clearing contract. The entire surface of the site was cleared, and surface 0 material was collected from

  9. Limnological characteristics of selected lakes in the Nebraska sandhills, U.S.A., and their relation to chemical characteristics of adjacent ground water

    USGS Publications Warehouse

    La Baugh, J.W.

    1986-01-01

    Limnological characteristics of Crane, Hackberry, Island and Roundup Lakes, and chemical characteristics of shallow ground water, within the Crescent Lake National Wildlife Refuge, western Nebraska, were determined during a preliminary investigation of the interaction between lakes and ground water in this study area between 1980 and 1984. When ice cover was absent, the lakes were well-mixed vertically, regardless of season. Depth to which 1% of surface illumination penetrated was commonly less than 1m. Variability in light penetration, as measured by Secchidisk transparency, appeared to be unrelated to changes in algal biomass, even though algal biomass, measured as chlorophyll a, varied seasonally within a two-order-of-magnitude range. Blue-green algae were the most abundant phytoplankton; this condition occurred most often when the ratio of total nitrogen to total phosphorus in the lakes' water was less than 29. Although rotifers and copepod naupli commonly were the most abundant zooplankton in the lakes, cladocerans were dominant occasionally. Either sodium or calcium was the most abundant cation, and bicarbonate was the most abundant anion, in water from water-table wells and lakes sampled during the study. The second most abundant cation in the ground water was related to the location of the sampled well within the ground-water system. The lakes were a source of dissolved organic carbon seeping to ground water. Chemical and hydrologic data indicate there is interaction between lakes and ground water in the study area. ?? 1986.

  10. Bathymetry and Geology of the Floor of Yellowstone Lake, Yellowstone National Park, Wyoming, Idaho, and Montana

    USGS Publications Warehouse

    Morgan, L.A.; Shanks, Wayne C.; Lee, G.K.; Webring, M.W.

    2007-01-01

    High-resolution, multi-beam sonar mapping of Yellowstone Lake was conducted by the U.S. Geological Survey in conjunction with the National Park Service from 1999 to 2002. Yellowstone Lake is the largest high-altitude lake in North America, at an altitude of 2,357 m with a surface area of 341 km2. More than 140 rivers and streams flow into Yellowstone Lake. The Yellowstone River, which enters at the southern end of the lake into the Southeast Arm, dominates the inflow of water and sediment (Shanks and others, 2005). The only outlet from the lake is at Fishing Bridge where the Yellowstone River flows northward discharging 375 to 4,600 cubic feet per second. The multi-beam sonar mapping occurred over a four-year period beginning in 1999 with mapping of the northern basin, continued in 2000 in West Thumb basin, in 2001 in the central basin, and in 2002 in the southern part of the lake including the Flat Mountain, South, and Southeast Arms.

  11. Subglacial Lake CECs: Discovery and in situ survey of a privileged research site in West Antarctica

    NASA Astrophysics Data System (ADS)

    Rivera, Andrés.; Uribe, José; Zamora, Rodrigo; Oberreuter, Jonathan

    2015-05-01

    We report the discovery and on-the-ground radar mapping of a subglacial lake in Antarctica, that we have named Lake CECs (Centro de Estudios Científicos) in honor of the institute we belong to. It is located in the central part of the West Antarctic Ice Sheet, right underneath the Institute Ice Stream and Minnesota Glacier ice divide, and has not experienced surface elevation changes during the last 10 years. The ratio between the area of the subglacial lake and that of its feeding basin is larger than those for either subglacial lakes Ellsworth or Whillans, and it has a depth comparable to that of Ellsworth and greater than that of Whillans. Its ice thickness is ˜600 m less than that over Ellsworth. The lake is very likely a system with long water residence time. The recent finding of microbial life in Lake Whillans emphasizes the potential of Subglacial Lake CECs for biological exploration.

  12. 77 FR 59394 - Wills Creek Hydro, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-27

    ..., Coshocton County, Ohio. The sole purpose of a preliminary permit, if issued, is to grant the permit holder... Lake which has a surface area of 11,450 acres at a normal lake elevation of 742 feet and a maximum storage capacity of 196,000 acre-feet; (2) a 1,950-foot-long, 87-foot-high earth fill dam; (3) a 100-foot...

  13. A sensor-based energy balance method for the distributed estimation of evaporation over the North American Great Lakes

    NASA Astrophysics Data System (ADS)

    Fries, K. J.; Kerkez, B.; Gronewold, A.; Lenters, J. D.

    2014-12-01

    We introduce a novel energy balance method to estimate evaporation across large lakes using real-time data from moored buoys and mobile, satellite-tracked drifters. Our work is motivated by the need to improve our understanding of the water balance of the Laurentian Great Lakes basin, a complex hydrologic system that comprises 90% of the United States' and 20% of the world's fresh surface water. Recently, the lakes experienced record-setting water level drops despite above-average precipitation, and given that lake surface area comprises nearly one third of the entire basin, evaporation is suspected to be the primary driver behind the decrease in water levels. There has historically been a need to measure evaporation over the Great Lakes, and recent hydrological phenomena (including not only record low levels, but also extreme changes in ice cover and surface water temperatures) underscore the urgency of addressing that need. Our method tracks the energy fluxes of the lake system - namely net radiation, heat storage and advection, and Bowen ratio. By measuring each of these energy budget terms and combining the results with mass-transfer based estimates, we can calculate real-time evaporation rates on sub-hourly timescales. To mitigate the cost prohibitive nature of large-scale, distributed energy flux measurements, we present a novel approach in which we leverage existing investments in seasonal buoys (which, while providing intensive, high quality data, are costly and sparsely distributed across the surface of the Great Lakes) and then integrate data from less costly satellite-tracked drifter data. The result is an unprecedented, hierarchical sensor and modeling architecture that can be used to derive estimates of evaporation in real-time through cloud-based computing. We discuss recent deployments of sensor-equipped buoys and drifters, which are beginning to provide us with some of the first in situ measurements of overlake evaporation from Earth's largest lake system, opening up the potential for improved and integrated monitoring and modeling of the Great Lakes water budget.

  14. InSAR detection of aquifer recovery: Case studies of Koehn Lake (central California) and Lone Tree Gold Mine (Basin and Range)

    NASA Astrophysics Data System (ADS)

    Wdowinski, S.; Greene, F.; Amelung, F.

    2013-12-01

    Anthropogenic intervention in groundwater flow and aquifer storage often results in vertical movements of Earth's surface, which are well detected by InSAR observations. Most anthropogenic intervention occurs due to groundwater extraction for both agriculture and human consumption and results in land subsidence. However in some cases, ending anthropogenic intervention can lead to aquifer recovery and, consequently, surface uplift. In this study we present two such cases of aquifer recovery. The first case is the aquifer beneath Koehn Lake in Central California, which was overused to meet agricultural demands until the 1990's. The second case is the Lone Tree Gold Mine in Nevada that during active mining in the 1991-2006 groundwater pumping disrupted the aquifer and cause subsidence. But after mining ceased, groundwater flow was recovered and resulted in uplift. In both cases we studied the surface uplift using InSAR time series observations. We conduct an ERS and Envisat InSAR survey over Koehn Lake in California and Lone Tree Gold Mine in Nevada between 1992 and 2010. We followed the SBAS algorithm to generate a time-series of ground displacements and average velocities of pixels, which remain coherent through time in the SAR dataset. A total of 100 and 80 combined ERS and Envisat SAR dates are inverted for Koehn Lake and Lone Tree Gold Mine respectively. Results for the Koehn Lake area indicate a rapid uplift of about 3.5 mm/yr between 1992-2000 and a slower uplift rate of 1.6 mm/yr between 2000-2004, suggesting a decrease in the recovery process. The observed uplift correlates well with groundwater level increase in the Koehn Lake area. Results for the Lone Tree Gold Mine show a constant subsidence (~ 1 cm/yr) due to groundwater extraction between 1992-2006, but uplift of ~1 cm/yr since the beginning of 2007. In both case studies, InSAR observations reveal that the aquifer recovery is accompanied by surface uplift. We plan to use the InSAR observations and the groundwater level records to model and better understand aquifer recovery processes.

  15. Satellite remote sensing for modeling and monitoring of water quality in the Great Lakes

    NASA Astrophysics Data System (ADS)

    Coffield, S. R.; Crosson, W. L.; Al-Hamdan, M. Z.; Barik, M. G.

    2017-12-01

    Consistent and accurate monitoring of the Great Lakes is critical for protecting the freshwater ecosystems, quantifying the impacts of climate change, understanding harmful algal blooms, and safeguarding public health for the millions who rely on the Lakes for drinking water. While ground-based monitoring is often hampered by limited sampling resolution, satellite data provide surface reflectance measurements at much more complete spatial and temporal scales. In this study, we implemented NASA data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to build robust water quality models. We developed and validated models for chlorophyll-a, nitrogen, phosphorus, and turbidity based on combinations of the six MODIS Ocean Color bands (412, 443, 488, 531, 547, and 667nm) for 2003-2016. Second, we applied these models to quantify trends in water quality through time and in relation to changing land cover, runoff, and climate for six selected coastal areas in Lakes Michigan and Erie. We found strongest models for chlorophyll-a in Lake Huron (R2 = 0.75), nitrogen in Lake Ontario (R2=0.66), phosphorus in Lake Erie (R2=0.60), and turbidity in Lake Erie (R2=0.86). These offer improvements over previous efforts to model chlorophyll-a while adding nitrogen, phosphorus, and turbidity. Mapped water quality parameters showed high spatial variability, with nitrogen concentrated largely in Superior and coastal Michigan and high turbidity, phosphorus, and chlorophyll near urban and agricultural areas of Erie. Temporal analysis also showed concurrence of high runoff or precipitation and nitrogen in Lake Michigan offshore of wetlands, suggesting that water quality in these areas is sensitive to changes in climate.

  16. Monitoring and Attributions of Recent Dynamics in East Asia's Largest Fluvial Lake System: Integration of Remote Sensing, Hydrological Modeling, and Gauging Measurements

    NASA Astrophysics Data System (ADS)

    Wang, J.; Sheng, Y.; Wada, Y.

    2017-12-01

    The fluvial lake system across China's Yangtze Plain (YP), a World Wildlife Fund (WWF) ecoregion, are critical freshwater storages for nearly half a billion people. Our mapping using daily MODIS imagery revealed an approximately 10% net loss in the YP lake area from 2000 to 2011. Causes of this decadal lake decline were highly contentious, as it coincided with several meteorological droughts, a rising human water consumption (HWC), and the initial and yearly intensified water regulation from the world's largest hydroelectric project, the Three Gorges Dam (TGD). Here we integrated optical remote sensing, hydrological modeling, and in situ measurements to decouple the impacts of climate variability and anthropogenic activities including (i) Yangtze flow and sediment alterations by the TGD and (ii) HWC in agricultural, industrial, and domestic sectors throughout the downstream Yangtze Basin. Results suggest that this decadal lake decline was predominantly driven by climate variability closely linked to the El Niño-Southern Oscillation. Studied human activities, despite varying seasonal impacts that peak in fall, contribute ˜10-20% or less to the inter-annual lake area decline. Given that the TGD impacts on the total YP lake area and its seasonal variation are both under ˜5%, we also dismiss the speculation that the TGD might be responsible for evident downstream climate change by altering lake surface extent and thus open water evaporation. Nevertheless, anthropogenic impacts exhibited a strengthening trend during the past decade. Although the TGD has reached its full-capacity water regulation, the negative impacts of HWC and TGD-induced net channel erosion, which are already comparable to that of TGD's flow regulation, may continue to grow as crucial anthropogenic factors to future YP lake conservation.

  17. Atmospheric corrections for satellite water quality studies

    NASA Technical Reports Server (NTRS)

    Piech, K. R.; Schott, J. R.

    1975-01-01

    Variations in the relative value of the blue and green reflectances of a lake can be correlated with important optical and biological parameters measured from surface vessels. Measurement of the relative reflectance values from color film imagery requires removal of atmospheric effects. Data processing is particularly crucial because: (1) lakes are the darkest objects in a scene; (2) minor reflectance changes can correspond to important physical changes; (3) lake systems extend over broad areas in which atmospheric conditions may fluctuate; (4) seasonal changes are of importance; and, (5) effects of weather are important, precluding flights under only ideal weather conditions. Data processing can be accomplished through microdensitometry of scene shadow areas. Measurements of reflectance ratios can be made to an accuracy of plus or minus 12%, sufficient to permit monitoring of important eutrophication indices.

  18. Long-term chloride concentrations in North American and European freshwater lakes

    PubMed Central

    Dugan, Hilary A.; Summers, Jamie C.; Skaff, Nicholas K.; Krivak-Tetley, Flora E.; Doubek, Jonathan P.; Burke, Samantha M.; Bartlett, Sarah L.; Arvola, Lauri; Jarjanazi, Hamdi; Korponai, János; Kleeberg, Andreas; Monet, Ghislaine; Monteith, Don; Moore, Karen; Rogora, Michela; Hanson, Paul C.; Weathers, Kathleen C.

    2017-01-01

    Anthropogenic sources of chloride in a lake catchment, including road salt, fertilizer, and wastewater, can elevate the chloride concentration in freshwater lakes above background levels. Rising chloride concentrations can impact lake ecology and ecosystem services such as fisheries and the use of lakes as drinking water sources. To analyze the spatial extent and magnitude of increasing chloride concentrations in freshwater lakes, we amassed a database of 529 lakes in Europe and North America that had greater than or equal to ten years of chloride data. For each lake, we calculated climate statistics of mean annual total precipitation and mean monthly air temperatures from gridded global datasets. We also quantified land cover metrics, including road density and impervious surface, in buffer zones of 100 to 1,500 m surrounding the perimeter of each lake. This database represents the largest global collection of lake chloride data. We hope that long-term water quality measurements in areas outside Europe and North America can be added to the database as they become available in the future. PMID:28786983

  19. Long-term chloride concentrations in North American and European freshwater lakes.

    PubMed

    Dugan, Hilary A; Summers, Jamie C; Skaff, Nicholas K; Krivak-Tetley, Flora E; Doubek, Jonathan P; Burke, Samantha M; Bartlett, Sarah L; Arvola, Lauri; Jarjanazi, Hamdi; Korponai, János; Kleeberg, Andreas; Monet, Ghislaine; Monteith, Don; Moore, Karen; Rogora, Michela; Hanson, Paul C; Weathers, Kathleen C

    2017-08-08

    Anthropogenic sources of chloride in a lake catchment, including road salt, fertilizer, and wastewater, can elevate the chloride concentration in freshwater lakes above background levels. Rising chloride concentrations can impact lake ecology and ecosystem services such as fisheries and the use of lakes as drinking water sources. To analyze the spatial extent and magnitude of increasing chloride concentrations in freshwater lakes, we amassed a database of 529 lakes in Europe and North America that had greater than or equal to ten years of chloride data. For each lake, we calculated climate statistics of mean annual total precipitation and mean monthly air temperatures from gridded global datasets. We also quantified land cover metrics, including road density and impervious surface, in buffer zones of 100 to 1,500 m surrounding the perimeter of each lake. This database represents the largest global collection of lake chloride data. We hope that long-term water quality measurements in areas outside Europe and North America can be added to the database as they become available in the future.

  20. Estimation of chlorophyll-a concentration on an inland lake by using satellite data.

    NASA Astrophysics Data System (ADS)

    Iwata, T.

    2017-12-01

    Chlorophyll concentration is common as an index of water quality and phytoplankton activity in coastal areas and lake water. In this research, we propose a method to estimate chlorophyll-a distribution of lake surface by using satellite data. The satellite data used is the sea surface reflectance of 3 channels of band-9, -10, and -12 by MODIS/Aqua MYDOCGA data provided by NASA/EOSDIS, and its data resolution is spatially 1 km and temporally 1 day. As index for estimating chlorophyll-a from reflection intensity, four indices of two types are proposed and comparatively analyzed. One of the two types is the ratio of the reflectance of the visible green light band (Gr) to the one of the visible blue light band (Bl), and the other index is obtained by normalizing difference of the reflectance between two bands. The two types of indices are expressed as follows. * Band ratio (BR) = Gr / Bl * Normalized difference (ND) = (Gr-Bl) / (Gr+Bl) As the visible blue light band, band-9 (438-448 nm) and band-10 (483-493 nm) were used. The four indices are represented as BR9, BR10, ND9, and ND10. The Lake Biwa in Japan is selected as the test area to be analyzed. At the Lake, temperature and the chlorophyll-a concentration around the lake center are periodically measured every month, and data is published. From April 2011 to December 2015, correlation analysis was done using 29 data on which the water measurement date and the valid satellite data acquisition date coincided ( Fig.1 and 2 ). Based on the analysis, the following two formulas were shown as models that can successfully express surface chlorophyll-a concentration. * Chl-a [μg/L] = 6.11×BR10 - 2.61 * Chl-a [μg/L] = 32.6×ND102 + 10.2×ND10 + 3.24

  1. Multisensor analysis of hydrologic features with emphasis on the Seasat SAR

    NASA Technical Reports Server (NTRS)

    Foster, J. L.; Hall, D. K.

    1981-01-01

    Synthetic aperture radar (SAR) imagery of the Wind River Range area in Wyoming is compared with visible and near-infrared imagery of the same area. Data from the Seasat L-Band SAR and an aircraft X-Band SAR are compared with Landsat Return Beam Vidicon (RBV) visible data and near-infrared aerial photography and topographic maps of the same area. It is noted that visible and near-infrared data provide more information than the SAR data when conditions are the most favorable. The SAR penetrates clouds and snow, however, and data can be acquired day or night. Drainage density detail is good on SAR imagery because individual streams show up well owing to riparian vegetation; this causes higher radar reflections which result from the 'rough' surface which vegetation creates. In the winter image, the X-Band radar data show high returns because of cracks on the lake ice surfaces. High returns can also be seen in the L-Band SAR imagery of the lakes due to ripples on the surface induced by wind. It is concluded that the use of multispectral data would optimize analysis of hydrologic features.

  2. Collaborative modelling and integrated decision support system analysis of a developed terminal lake basin

    USGS Publications Warehouse

    Niswonger, Richard G.; Allander, Kip K.; Jeton, Anne E.

    2014-01-01

    A terminal lake basin in west-central Nevada, Walker Lake, has undergone drastic change over the past 90 yrs due to upstream water use for agriculture. Decreased inflows to the lake have resulted in 100 km2 decrease in lake surface area and a total loss of fisheries due to salinization. The ecologic health of Walker Lake is of great concern as the lake is a stopover point on the Pacific route for migratory birds from within and outside the United States. Stakeholders, water institutions, and scientists have engaged in collaborative modeling and the development of a decision support system that is being used to develop and analyze management change options to restore the lake. Here we use an integrated management and hydrologic model that relies on state-of-the-art simulation capabilities to evaluate the benefits of using integrated hydrologic models as components of a decision support system. Nonlinear feedbacks among climate, surface-water and groundwater exchanges, and water use present challenges for simulating realistic outcomes associated with management change. Integrated management and hydrologic modeling provides a means of simulating benefits associated with management change in the Walker River basin where drastic changes in the hydrologic landscape have taken place over the last century. Through the collaborative modeling process, stakeholder support is increasing and possibly leading to management change options that result in reductions in Walker Lake salt concentrations, as simulated by the decision support system.

  3. Continued studies of acid rain and its effects on the Baton Rouge area

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Robinson, J.W.; Ghane, H.

    1983-01-01

    The acidity of rain water was measured in the Baton Rouge, Louisiana area from June 1981 to September 1982. Coordinated measurements were taken of the dissolved oxygen concentration in two local lakes before and after each rainfall. About 50% of the rainfall observed was quite acidic, with about 25% of the rain having a pH of 4 or less. Rain was more acidic during warm summers than in the winter weather. Rainfall during 1982 was, on a month to month comparison, more acidic than in 1981. Attempts were also made to discover any possible correlation of pH values with windmore » direction. The acidity of each of the two lakes increased over the time of the study. The dissolved oxygen content in each lake increased after periods of rain, probably due to a high concentration of oxygen in the rainwater. The buffering capacities of the lakes was measurable. However, it is noted that the larger lake was undergoing dredging at the time of the study and showed considerably less buffer capacity than the smaller lake. The smaller lake was far more affected by surface drainage and thus should have been more influenced by the acid rain. 7 references, 7 figures, 1 table.« less

  4. Study of Morphologic Change in Poyang Lake Basin Caused by Sand Dredging Using Multi-temporal Landsat Images and DEMs

    NASA Astrophysics Data System (ADS)

    Qi, S.; Zhang, X.; Wang, D.; Zhu, J.; Fang, C.

    2014-11-01

    Sand dredging has been practiced in rivers, lakes, harbours and coastal areas in recent years in China mostly because of demand from construction industry as building material. Sand dredging has disturbed aquatic ecosystems by affecting hydrological processes, increasing content of suspended sediments and reducing water clarity. Poyang Lake, connecting with Yangtze River in the lower reaches of the Yangtze River, is the largest fresh water lake in China. Sand dredging in Poyang Lake has been intensified since 2001 because such practice was banned in Yangtze River and profitable. In this study, the morphologic change caused by sand dredging in Poyang Lake basin was analysed by overlaying two DEMs acquired in 1952 and 2010 respectively. Since the reflectance of middle infrared band for sand dredging vessel is much higher than that of water surface, sand dredging vessels were showed as isolated grey points and can be counted in the middle infrared band in 12 Landsat images acquired in flooding season during 2000~2010. Another two Landsat images (with low water level before 2000 and after 2010) were used to evaluate the morphologic change by comparing inundation extent and shoreline shape. The following results was obtained: (1) vessels for sand dredging are mainly distributed in the north of Poyang Lake before 2007, but the dredging area was enlarged to the central region and even to Gan River; (2) sand dredging area reached to about 260.4 km2 and is mainly distributed in the north of Songmen Mountain and has been enlarged to central of Poyang Lake from the distribution of sand vessels since 2007. Sand dredged from Poyang Lake was about 1.99 × 109 m3 or 2448 Mt assuming sediment bulk density of 1.23 t m-3. It means that the magnitude of sand mining during 2001-2010 is almost ten times of sand depositions in Poyang Lake during 1955-2010; (3) Sand dredging in Poyang Lake has alternated the lake capacity and discharge section area, some of the watercourse in the northern channel was enlarged by more than 1 km when in low lake level. This study is useful to understand the change of hydrological system, especially the drying up trend in Poyang Lake in recent autumns and winters.

  5. NTS radiological assessment project: comparison of delta-surface interpolation with kriging for the Frenchman Lake region of area 5

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Foley, T.A. Jr.

    The primary objective of this report is to compare the results of delta surface interpolation with kriging on four large sets of radiological data sampled in the Frenchman Lake region at the Nevada Test Site. The results of kriging, described in Barnes, Giacomini, Reiman, and Elliott, are very similar to those using the delta surface interpolant. The other topic studied is in reducing the number of sample points and obtaining results similar to those using all of the data. The positive results here suggest that great savings of time and money can be made. Furthermore, the delta surface interpolant ismore » viewed as a contour map and as a three dimensional surface. These graphical representations help in the analysis of the large sets of radiological data.« less

  6. Dynamic interactions between glacier and glacial lake in the Bhutan Himalaya

    NASA Astrophysics Data System (ADS)

    Tsutaki, S.; Fujita, K.; Yamaguchi, S.; Sakai, A.; Nuimura, T.; Komori, J.; Takenaka, S.; Tshering, P.

    2012-04-01

    A number of supraglacial lakes formed on the termini of debris-covered glaciers in the Bhutan Himalaya as a result of glacier retreat due to climate change. The terminal part of the lake-terminating glaciers flow faster than that of the land-terminating glaciers because the basal ice motion is enhanced by high subglacial water pressure generated by lake water. Increased ice flux caused by the accelerated glacier flow could be dissipated through the calving process which reduced the glacier thickness. It is important to understand the interaction between lake formation and glacier dynamics. Although glacier flow velocity has been measured by remote-sensing analysis in several regions of the Himalayas, glacier thinning rates have not been observed by neither in-situ nor remote-sensing approaches. The lack of field data raises limitation to interpretations for glacier dynamics. We investigate the influence of the presence/absence of glacial lakes on glacier dynamics and changes in surface elevation. We study two debris-covered glaciers in the Lunana region, the Bhutan Himalaya. Thorthormi Glacier is a land-terminating glacier with some supraglacial lakes while Lugge Glacier is a lake-terminating glaciers. We surveyed the surface elevation of debris-covered areas of the two glaciers in 2004 and 2011 by a differential GPS. Change in surface elevation of the lake-terminating Lugge Glacier (-5.4--2.4 m yr-1) was much more negative than that of the land-terminating Thorthormi Glacier (-3.3-0.6 m yr-1). Surface flow speed of the Thorthormi Glacier measured during 2002-2004 was faster in the upper reaches (~90 m yr-1) and reduced toward the downstream (40 m yr-1). In contrast, the surface flow speed at the Lugge Glacier measured in the same periods was 40-55 m yr-1 and the greatest at the lower most part. Observed spatial distribution of surface flow velocity at both glaciers were evaluated by a two-dimensional numerical flow model. Calculated emergence velocities are 1.9-18.8 m yr-1 at the Thorthormi Glacier while -12.0-2.7 m yr-1 at the Lugge Glacier. This result suggests that decreasing in flow velocity towards the terminus in the Thorthormi Glacier causes compressive flow. It suggests that the compressive flow of the Thorthormi Glacier counterbalanced surface melting, resulting in inhibition of the surface lowering. In contrast, the extensional flow of the Lugge Glacier accelerated the surface lowering. Speed up of glacier terminus induced extensional flow regime causes the thinning of ice and increase in basal motion, which will lead to further flow acceleration. Such positive feedbacks have been found over the ice streams in the polar ice sheets. In this study we showed the observational evidences, in which the similar feedbacks make contrast the terminus behaviors of glaciers in the Bhutan Himalaya. If the supraglacial lake on Thorthormi Glacier expanded, the surface lowering may be accelerated in the future.

  7. Hydrology of the Floral City Pool of Tsala Apopka Lake, west-central Florida

    USGS Publications Warehouse

    Bradner, L.A.

    1988-01-01

    Tsala Apopka Lake, in west-central Florida, has an area of about 19,000 acres and is divided into three water-management pools, with the Floral City Pool, the most upgradient. The Floral City Pool, which has a surface area of approximately 4,750 acres, contains an extensive combination of lakes, wetlands, and connecting canals. The Pool receives inflow from the Withlacoochee River through two canals. Outflow is through one manmade canal and one natural slough. Canal flow is partially controlled by manmade structures. A cumulative deficit of 19.4 inches of rainfall from August 1984 through May 1985 reduced surface-water inflow to the Floral City Pool to about 0.5 cu ft/sec by May 1985. During May 1985, pool levels declined approximately 0.04 ft/day. By the end of May, there was no observable outflow. From June 1985 through September 1985, 39.8 inches of rainfall caused above-average inflow to the Floral City Pool and a pool-level increase of 6.2 ft. The inflow of 340 CFS nearly equaled the outflow of 338 CFS by the end of September. (USGS)

  8. Bathymetry of Lake Manatee, Manatee County, Florida, 2009

    USGS Publications Warehouse

    Bellino, Jason C.; Pfeiffer, William R.

    2010-01-01

    Lake Manatee, located in central Manatee County, Florida, is the principal drinking-water source for Manatee and Sarasota Counties. The drainage basin of Lake Manatee encompasses about 120 square miles, and the reservoir covers a surface area of about 1,450 acres at an elevation of 38.8 feet above NAVD 88 or 39.7 feet above NGVD 29. The full pool water-surface elevation is 39.1 feet above NAVD 88 (40.0 feet above NGVD 29), and the estimated minimum usable elevation is 25.1 feet above NAVD 88 (26.0 feet above NGVD 29). The minimum usable elevation is based on the elevation of water intake structures. Manatee County has used the stage/volume relation that was developed from the original survey in the 1960s to estimate the volume of water available for consumption. Concerns about potential changes in storage capacity of the Lake Manatee reservoir, coupled with a recent drought, led to this bathymetry mapping effort.

  9. Ground-water resources of the Alma area, Michigan

    USGS Publications Warehouse

    Vanlier, Kenneth E.

    1963-01-01

    The Alma area consists of 30 square miles in the northwestern part of Gratiot County, Mich. It is an area of slight relief gently rolling hills and level plains and is an important agricultural center in the State.The Saginaw formation, which forms the bedrock surface in part of the area, is of relatively low permeability and yields water containing objectionable amounts of chloride. Formations below the Saginaw are tapped for brine in and near the Alma area.The consolidated rocks of the Alma area are mantled by Pleistocene glacial deposits, which are as much as 550 feet thick where preglacial valleys were eroded into the bedrock. The glacial deposits consist of till, glacial-lake deposits, and outwash. Till deposits are at the surface along the south-trending moraines that cross the area, and they underlie other types of glacial deposits at depth throughout the area. The till deposits are of low permeability and are not a source of water to wells, though locally they include small lenses of permeable sand and gravel.In the western part of the area, including much of the city of Alma, the glacial-lake deposits consist primarily of sand and are a source of small supplies of water. In the northeastern part of the area the lake deposits are predominantly clayey and of low permeability.Sand and gravel outwash yields moderate and large supplies of water within the area. Outwash is present at the surface along the West Branch of the Pine River. A more extensive deposit of outwash buried by the lake deposits is the source of most of the ground water pumped at Alma. The presence of an additional deposit of buried outwash west and southwest of the city is inferred from the glacial history of the area. Additional water supplies that may be developed from these deposits are probably adequate for anticipated population and industrial growth.Water levels have declined generally in the vicinity of the city of Alma since 1920 in response to pumping for municipal and industrial supplies. The declines are not excessive, and during the late 1950's water levels in parts of Alma have risen slightly, because of dispersion of the pumping stations.The ground water in the Alma area generally is very hard and high in iron. Locally, the buried outwash that underlies the city of Alma is contaminated by phenolic substances. This limits the amount of ground water available for municipal supply within the city, although reclamation of the contaminated part of the aquifer is considered feasible.

  10. Lake Billy Shaw Operations and Maintenance, Final Annual Report 2000.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dodson, Guy; Pero, Vincent

    Lake Billy Shaw is a newly constructed earthen dam reservoir with a surface area of 430 acres. Construction on the dam and structures was complete in November of 1998. The fish screen structures were complete in December of 1998, with initial filling in May 1999. Upon initial filling, dam structures, monitoring wells, fish screen structures, and lake level were monitored daily, with recordings being taken three times/week. During June 1999 the water to the lake was turned off in order to complete additional construction work on the lake. This work included installation of culverts around the perimeter road, installation ofmore » boat launches, finish work on the spillway structure, pumphouse and well protection and planting 4 trees along the entrance to the boat launch area. The water was turned on again in late September 1999 with all structures having been checked, fish screens greased and maintained and well levels being monitored. In 2000 the Operations and Maintenance portion of the project began with monitoring of piezometers, water levels, biological monitoring, riparian plantings, protection of shorelines, and maintenance of structures and appurtances.« less

  11. Extremely acid Permian lakes and ground waters in North America

    USGS Publications Warehouse

    Benison, K.C.; Goldstein, R.H.; Wopenka, B.; Burruss, R.C.; Pasteris, J.D.

    1998-01-01

    Evaporites hosted by red beds (red shales and sandstones), some 275-265 million years old, extend over a large area of the North American mid- continent. They were deposited in non-marine saline lakes, pans and mud- flats, settings that are typically assumed to have been alkaline. Here we use laser Raman microprobe analyses of fluid inclusions trapped in halites from these Permian deposits to argue for the existence of highly acidic (pH < 1) lakes and ground waters. These extremely acidic systems may have extended over an area of 200,000 km2. Modern analogues of such systems may be natural acid lake and groundwater systems (pH ~2-4) in southern Australia. Both the ancient and modern acid systems are characterized by closed drainage, arid climate, low acid-neutralizing capacity, and the oxidation of minerals such as pyrite to generate acidity. The discovery of widespread ancient acid lake and groundwater systems demands a re-evaluation of reconstructions of surface conditions of the past, and further investigations of the geochemistry and ecology of acid systems in general.

  12. Monitoring ground-surface heating during expansion of the Casa Diablo production well field at Mammoth Lakes, California

    USGS Publications Warehouse

    Bergfeld, D.; Vaughan, R. Greg; Evans, William C.; Olsen, Eric

    2015-01-01

    The Long Valley hydrothermal system supports geothermal power production from 3 binary plants (Casa Diablo) near the town of Mammoth Lakes, California. Development and growth of thermal ground at sites west of Casa Diablo have created concerns over planned expansion of a new well field and the associated increases in geothermal fluid production. To ensure that all areas of ground heating are identified prior to new geothermal development, we obtained high-resolution aerial thermal infrared imagery across the region. The imagery covers the existing and proposed well fields and part of the town of Mammoth Lakes. Imagery results from a predawn flight on Oct. 9, 2014 readily identified the Shady Rest thermal area (SRST), one of two large areas of ground heating west of Casa Diablo, as well as other known thermal areas smaller in size. Maximum surface temperatures at 3 thermal areas were 26–28 °C. Numerous small areas with ground temperatures >16 °C were also identified and slated for field investigations in summer 2015. Some thermal anomalies in the town of Mammoth Lakes clearly reflect human activity.Previously established projects to monitor impacts from geothermal power production include yearly surveys of soil temperatures and diffuse CO2 emissions at SRST, and less regular surveys to collect samples from fumaroles and gas vents across the region. Soil temperatures at 20 cm depth at SRST are well correlated with diffuse CO2 flux, and both parameters show little variation during the 2011–14 field surveys. Maximum temperatures were between 55–67 °C and associated CO2 discharge was around 12–18 tonnes per day. The carbon isotope composition of CO2 is fairly uniform across the area ranging between –3.7 to –4.4 ‰. The gas composition of the Shady Rest fumarole however has varied with time, and H2S concentrations in the gas have been increasing since 2009.

  13. Water budget and water quality of Ward Lake, flow and water-quality characteristics of the Braden River estuary, and the effects of Ward Lake on the hydrologic system, west-central Florida

    USGS Publications Warehouse

    Trommer, J.T.; DelCharco, M.J.; Lewelling, B.R.

    1999-01-01

    The Braden River is the largest tributary to the Manatee River. The river was dammed in 1936 to provide the city of Bradenton a source of freshwater supply. The resulting impoundment was called Ward Lake and had a storage capacity of about 585 million gallons. Reconstruction in 1985 increased the size of the reservoir to about 1,400 million gallons. The lake has been renamed the Bill Evers Reservoir and drains about 59 square miles. The Braden River watershed can be subdivided into three hydrologic reaches. The upper reach consists of a naturally incised free-flowing channel. The middle reach consists of a meandering channel affected by backwater as a result of the dam. The lower reach is a tidal estuary. Water budgets were calculated for the 1993 through 1997 water years. Mean surface-water inflow to Ward Lake for the 5-year period was 1,645 inches per year (equivalent depth over the surface of the lake), or about 81.8 percent of total inflow. Mean ground-water inflow was 311 inches per year, or about 15.5 percent. A mean of 55 inches of rain fell directly on the lake and accounted for only 2.7 percent. Mean surface-water outflow was 1,736 inches, or about 86.4 percent of total water leaving the lake. There was no net ground-water outflow from the lake. Mean surface-water withdrawal for public supply was 229 inches per year, or about 11.4 percent. Mean evaporation was 45 inches and accounted for only 2.2 percent of the mean outflow. Change in lake storage on the budget was negligible. Most chemical constituents contained in water flowing to Ward Lake meet the standards specified by the Florida Department of Environmental Protection and the U.S. Environmental Protection Agency. Phosphorus is the exception, exceeding the U.S. Environmental Protection Agency limits of 0.10 milligram per liter in most samples. However, the source of the phosphorus is naturally occurring phosphate deposits underlying the watershed. Organic nitrogen and orthophosphate are the dominant species of nutrients in the streams and the lake. A major source of water to the streams is the surficial aquifer system. Mineralized water pumped from the intermediate aquifer system and the Upper Floridan aquifer for irrigation of agricultural areas or golf courses has influenced the chemical composition of the surficial aquifer and surface-water systems. The Braden River estuary receives freshwater inflow from Ward Lake and from three major streams discharging downstream from the dam. Salinity levels in the estuary are affected by freshwater flow from these sources and by antecedent conditions in the estuary prior to flow events. The lowest salinity levels are often measured at the confluence with Williams and Gap Creeks rather than at the outfall from the lake. The chemical composition of water flowing from the tributaries to the estuary is similar to the chemical composition of water in the tributaries flowing to Ward Lake and does not appear to be affected by brackish water from high tides. Nitrogen concentrations in water from Glen Creek were greater than in water from all other tributaries in the watershed. Fertilizer from orange groves and stormwater runoff from urban and industrial areas affect the water quality in Glen Creek. The effects of the reservoir on the hydrology of the watershed were to change the middle reach of the river from a brackish water estuary ecosystem to a freshwater lake ecosystem, raise water levels in the surficial aquifer system adjacent to the river, change water quality, and reduce freshwater flow to the estuary during periods of low flow. The lake acts as a sink for total organic carbon, dissolved solids, calcium, chloride, and sulfate, thereby decreasing loads of these constituents to the estuary.

  14. Earth Observation

    NASA Image and Video Library

    2013-09-03

    ISS036-E-039778 (3 Sept. 2013) --- Caldera lakes to the northwest of Rome, Italy are featured in this image photographed by an Expedition 36 crew member on the International Space Station. The Lazio region of central Italy has many landforms of volcanic origin, including several large lakes that mark the locations of ancient volcanoes. This photograph highlights two such lakes, Lago di Vico and Lago Bracciano, located to the northwest of the capital city of Rome. Both lakes are located within calderas, large depressions that form after violent explosive eruptions empty a volcano’s underlying magma chamber. Any remnants of the volcanic edifice can then collapse into the newly-formed void space, leading to the creation of large depressions. These depressions can then fill partially or completely with water, forming permanent lakes. Lago Bracciano (left) is the larger of the two lakes highlighted in the image; it is approximately eight kilometers wide at its widest point, and is located 32 kilometers northwest of Rome. According to scientists, the volcanic activity that led to the formation of Lago Bracciano began approximately 600,000 years ago and continued to approximately 40,000 years ago as part of the formation of the Sabatini volcanic complex. While part of the lake formation was due to caldera collapse of part of a large magma chamber, the current depression was also formed by movement along numerous faults in the area – a process known as volcano-tectonic collapse. Located approximately 24 kilometers to the north-northwest of Lago Bracciano, Lago di Vico (right) occupies part of a caldera associated with eruptive activity that began approximately 800,000 years ago and continued until approximately 90,000 years ago. The caldera formed largely by the catastrophic eruption of the ancestral Vico volcano approximately 200,000-150,000 years ago. The final phase of volcanic activity in the caldera led to the formation of a small lava cone in the northeast quadrant known as Mount Venus. The extent of the lakes of Bracciano and Vico are readily apparent in this image due to sunglint – light reflecting back towards the observer from the water surfaces. This reflection gives a mirror-like sheen to the water surfaces in the image. Dark green forested areas associated with parks are visible near both lakes, while light gray to white regions indicate built areas - such as the city of Viterbo at right - and tilled fields (bottom center).

  15. Dynamics of an introduced and unexploited Lake Whitefish population in Lake Pend Oreille, Idaho

    USGS Publications Warehouse

    Hosack, Michael A.; Hansen, Michael J.; Horner, Ned J.

    2014-01-01

    To evaluate biological potential of a commercial fishery for an unexploited Lake Whitefish Coregonus clupeaformis population in Lake Pend Oreille, Idaho, we estimated population parameters related to production and yield. The length frequency based on trap-netting in autumn 2005 was normal with a mean of 448 mm TL, whereas the length frequency based on gillnetting in spring 2006 was bimodal with a mean of 390 mm TL. Sex composition was skewed toward females (0.66) during autumn trap-netting. Shape parameters β of weight–length models for females (β = 3.38) and males (β = 3.45) were similar to those of other unexploited populations. Instantaneous growth rates K for females (K = 0.144 per year) and males (K = 0.153 per year) were among the lowest for unexploited populations across the species’ range. Age at 50% maturity (females: 6.5 years; males: 6.0 years) and length at 50% maturity (females: 390 mm TL; males: 378 mm TL) were high for unexploited populations. The natural mortality rate M (0.149 per year, ages 11–36) was among the lowest observed for unexploited populations. Adult population density was lower than that of other populations based on total surface area (mean = 1.35 fish/ha; 95% confidence interval [CI] = 1.11–1.78 fish/ha) but was average based on lake area shallower than 70 m (4.07 fish/ha; 95% CI = 3.35–5.35 fish/ha). Population density of juveniles and adults averaged 84 fish/ha (95% CI = 52–143 fish/ha) over the entire surface area and 278 fish/ha (95% CI = 173–474 fish/ha) over depths shallower than 70 m. The difference between the low M of the unexploited population in Lake Pend Oreille (M = 0.149 per year; annual mortality rate A = 14%) and the high sustainable total mortality Z of exploited stocks in the Laurentian Great Lakes (Z = 1.204; A = 70%) suggests a large scope for sustainable fishing mortality F (1.055 per year; exploitation rate u = 61%) that is equivalent to a sustainable Lake Whitefish harvest of 55,000 individuals (50,000–60,000 individuals) and 49,000 kg (45,000–54,000 kg) from Lake Pend Oreille.

  16. Changing climate in the Lake Superior region: a case study of the June 2012 flood and its effects on the western-lake water column

    NASA Astrophysics Data System (ADS)

    Minor, E. C.; Forsman, B.; Guildford, S. J.

    2013-12-01

    In Lake Superior, the world's largest freshwater lake by area, we are seeing annual surface-water temperature increases outpacing those of the overlying atmosphere. We are also seeing ever earlier onsets of water-column stratification (in data sets from the mid-1980s to the present). In Minnesota, including the Lake Superior watershed, precipitation patterns are also shifting toward fewer and more extreme storm events, such as the June 2012 solstice flood, which impacted the western Lake Superior basin. We are interested in how such climatological changes will affect nutrient and carbon biogeochemistry in Lake Superior. The lake is currently an oligotrophic system exhibiting light limitation of primary production in winter and spring, with summer primary production generally limited by phosphorus and sometimes co-limited by iron. Analyses in the western arm of Lake Superior showed that the June 2012 flood brought large amounts of sediment and colored dissolved organic matter (CDOM) from the watershed into the lake. There was initially a ~50-fold spike in the total phosphorus concentrations (and a 5 fold spike in soluble reactive phosphorus) in flood-impacted waters. This disappeared rapidly, in large part due to sediment settling and did not lead to an increase in chlorophyll concentrations at monitored sampling sites. Instead, lake phytoplankton appeared light limited by a surface lens of warm water enriched in CDOM that persisted for over a month after the flood event itself. Our observations highlight the need for continuing research on these complex in-lake processes in order to make accurate predictions about longer term impacts of these large episodic inputs in CDOM, sediment, and nutrient loading.

  17. Water quality in the vicinity of Mosquito Creek Lake, Trumbull County, Ohio, in relation to the chemistry of locally occurring oil, natural gas, and brine

    USGS Publications Warehouse

    Barton, G.J.; Burruss, R.C.; Ryder, R.T.

    1998-01-01

    Environmental samples collected in the Mosquito Creek Lake area were used to characterize water quality in relation to the chemistry of locally occurring oil, natural gas, and brine and to establish baseline water quality. Mosquito Creek Lake (a manmade reservoir) and the shallow bedrock aquifers near the lake are major sources of potable water in central Trumbull County. The city of Warren relies on the lake as a sole source of potable water. Some of the lake bottom may be in direct hydraulic connection with the underlying aquifers. The city of Cortland, along the southeastern shore of the lake, relies on the Cussewago Sandstone aquifer as a sole source of potable water. This aquifer subcrops beneath the glacio-fluvial sediments that underlie the lake. Nearly all residential homes around the lake, with the exception of homes in the city of Cortland, rely on domestic supply wells as a source of potable water.Oil and natural gas exploration and production have been ongoing in the Mosquito Creek Lakearea since the discovery of the historic Mecca Oil Pool in the Mississippian Berea and Cussewago Sandstones in 1860. Since the late 1970' s, the major drilling objective and zone of production is the Lower Silurian Clinton sandstone. The oil and natural gas resources of the Mosquito Creek Lake area, including reservoir pressure, production history, and engineering and abandonment practices are described in this report.The chemical and isotopic characteristics of the historic Mecca oil and natural gas are very different than those of the Clinton sandstone oil and natural gas. Gas chromatograms show that Mecca oil samples are extensively altered by biodegradation, whereas Clinton sandstone oils are not. Extensive alteration of Mecca oil is consistent with their occurrence at very shallow depths (less than 100 ft below land surface) where microbial activity can affect their composition. Also, the carbon-isotope composition of dissolved methane gas from Berea and Cussewago Sandstone water samples indicates that the gas is microbially generated, whereas the Clinton sandstone gases are thermogenically generated.Methane gas, in addition to crude oil, occurs naturally in the shallow Berea and Cussewago Sandstone aquifers in the Mosquito Creek Lake area and concentrations of dissolved methane are significant in the city of Cortland public-supply wells and in the domestic-supply wells near the southern shore of the lake. Water associated with oil and gas in the Clinton sandstone is a brine with high concentrations of chloride. Water from the Berea and Cussewago Sandstones, however, is fresh and potable. The contrasting geochemical characteristics are important for addressing water-quality issues that relate to oil and natural gas development in the Mosquito Creek area.A reexamination of the geologic framework and results of a subsurface-gas survey show that crude oil in the historic Mecca Oil Pool probably does not seep into Mosquito Creek Lake. Environmental samples show no evidence of any measurable release of oil, gas, or brine from the deeper Clinton sandstone oil and gas wells to the shallow aquifers, the lake, or lake tributaries. Brine is not associated with the hydrocarbons in the shallow Berea-Cussewago aquifer system and therefore cannot be a source of brine contamination. A mixing diagram constructed for dissolved bromide and chloride in surface water and water-supply wells shows no demonstrable mixing of these water resources with brine from the Clinton sandstone. There is some notable salinity in surface waters; however, the water is bromide poor, and a mixing diagram indicates that some local ground waters are influenced by halite solutions, presumably derived from leaching of road salt or from septic effluent.

  18. Characteristics of petroleum contaminants and their distribution in Lake Taihu, China.

    PubMed

    Guo, Jixiang; Fang, Jia; Cao, Jingjing

    2012-08-31

    Taihu Lake is a typical plain eutrophic shallow lake. With rapidly economic development of the lake area, the petroleum products and oil wastewater produced in various processes have been inevitably discharged into Taihu Lake. As the major fresh water resource in the economically developed region of Yangtze River Delta, the water quality and environmental condition of Taihu Lake have the direct bearing on the natural environment and sustainable development of economy in this region. For this reason we carried out the study to explore the composition, distribution characteristics and sources of petroleum contaminants in Taihu Lake. The aim of this study was to provide the basis for standard management and pollution control of the Taihu Lake environment. The result showed that water samples from near industrial locations were of relatively higher petroleum contaminants concentrations. The oil pollutants concentrations in different areas of Lake Taihu ranged from 0.106 mg/L to 1.168 mg/L, and the sequence of total contents distribution characteristics of petroleum pollutants from high to low in different regions of Taihu Lake was: "Dapu", "Xiaomeikou", "Zhushan Bay", "Lake center", "Qidu". The results showed that total concentrations of n-alkanes and PAHs ranged from 0.045 to 0.281 mg/L and from 0.011 to 0.034 mg/L respectively. In the same region, the concentrations of hydrocarbon pollutants in the surface and bottom of the lake were higher than that in the middle. This paper reached a conclusion that the petroleum contaminants in Taihu Lake mainly derived from petroleum pollution caused by human activities as indicated by OEP, bimodal distribution, CPI, Pr/Ph ratio, the LMW/HMW ratio and other evaluation indices for sources of n-alkanes and polycyclic aromatic hydrocarbons (PAHs).

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tan, Zeli; Zhuang, Qianlai; Shurpali, Narasinha J.

    Recent studies indicated that Arctic lakes play an important role in receiving, processing, and storing organic carbon exported from terrestrial ecosystems. To quantify the contribution of Arctic lakes to the global carbon cycle, we developed a one-dimensional process-based Arctic Lake Biogeochemistry Model (ALBM) that explicitly simulates the dynamics of organic and inorganic carbon in Arctic lakes. By realistically modeling water mixing, carbon biogeochemistry, and permafrost carbon loading, the model can reproduce the seasonal variability of CO2 fluxes from the study Arctic lakes. The simulated area-weighted CO2 fluxes from yedoma thermokarst lakes, non-yedoma thermokarst lakes and glacial lakes are 29.5 gmore » C m-2 yr-1, 13.0 g C m-2 yr-1 and 21.4 g C m-2 yr-1, respectively, close to the observed values (31.2 g C m-2 yr-1, 17.2 g C m-2 yr-1 and 16.5±7.7 g C m-2 yr-1, respectively). The simulations show that the high CO2 fluxes from yedoma thermokarst lakes are stimulated by the biomineralization of mobilized labile organic carbon from thawing yedoma permafrost. The simulations also imply that the relative contribution of glacial lakes to the global carbon cycle could be the largest because of their much larger surface area and high biomineralization and carbon loading. According to the model, sunlight-induced organic carbon degradation is more important for shallow non-yedoma thermokarst lakes but its overall contribution to the global carbon cycle could be limited. Overall, the ALBM model can simulate the whole-lake carbon balance of Arctic lakes, a difficult task for field and laboratory experiments and other biogeochemistry models.« less

  20. the observation, simulation and evaluation of lake-air interaction process over a high altitude small lake on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Wang, Binbin; Ma, Yaoming; Ma, Weiqiang; Su, Bob

    2017-04-01

    Lakes are an important part of the landscape on the Tibetan Plateau. The area that contains most of the plateau lakes has been expanding in recent years, but the impact of lakes on lake-atmosphere energy and water interactions is poorly understood because of a lack of observational data and adequate modeling systems. Furthermore, Precise measurements of evaporation and understanding of the physical controls on turbulent heat flux over lakes at different time scales have fundamental significance for catchment-scale water balance analysis and local-scale climate modeling. To test the performance of lake-air turbulent exchange models over high-altitude lakes and to understanding the driving forces for turbulent heat flux and obtain the actual evaporation over the small high-altitude lakes, an eddy covariance observational system was built above the water surface of the small Nam Co Lake (with an altitude of 4715 m and an area of approximately 1 km2) in April 2012. Firstly, we proposed the proper Charnock coefficient (0.031) and the roughness Reynolds number (0.54) for simulation using turbulent data in 2012, and validated the results using data in 2013 independently; secondly, wind speed shows significance at half-hourly time scales, whereas water vapor and temperature gradients have higher correlations over daily and monthly time scales in lake-air turbulent heat exchange; thirdly, the total evaporation in this small lake (812 mm) is approximately 200 mm larger than that from adjacent Nam Co (approximately 627 mm) during their ice-free seasons. Moreover, the energy stored during April to June is mainly released during September to November, suggesting an energy balance closure value of 0.97 over the entire ice-free season; lastly, 10 evaporation estimation methods are evaluated with the prepared datasets.

  1. Ground-penetrating radar--A tool for mapping reservoirs and lakes

    USGS Publications Warehouse

    Truman, C.C.; Asmussen, L.E.; Allison, H.D.

    1991-01-01

    Ground-penetrating radar was evaluated as a tool for mapping reservoir and lake bottoms and providing stage-storage information. An impulse radar was used on a 1.4-ha (3.5-acre) reservoir with 31 transects located 6.1 m (20 feet) apart. Depth of water and lateral extent of the lake bottom were accurately measured by ground-penetrating radar. A linear (positive) relationship existed between measured water depth and ground-penetrating radar-determined water depth (R2=0.989). Ground-penetrating radar data were used to create a contour map of the lake bottom. Relationships between water (contour) elevation and water surface area and volume were established. Ground-penetrating radar proved to be a useful tool for mapping lakes, detecting lake bottom variations, locating old stream channels, and determining water depths. The technology provides accurate, continuous profile data in a relatively short time compared to traditional surveying and depth-sounding techniques.

  2. Model Estimate of Pan-Arctic Lakes and Wetlands Methane Emissions and Their Future Climate Response

    NASA Astrophysics Data System (ADS)

    Chen, X.; Bohn, T. J.; Maksyutov, S. S.; Lettenmaier, D. P.

    2013-12-01

    Lakes and wetlands are important sources of the greenhouse gas CH4, whose emission rate is sensitive to climate. The northern high latitudes, which are especially susceptible to climate change, contain about 50% of the world's lakes and wetlands. Given predicted changes in the climate of this region over the next century (IPCC AR5 scenarios), there is concern about a possible positive feedback resulting from methane emissions from the region's wetlands and lakes. To study the climate response of emissions from northern high latitude lakes and wetlands, we employed a large-scale hydrology and carbon cycling model (Variable Infiltration Capacity model; VIC) over the Pan-Arctic domain, which was linked to an atmospheric model (Japan's National Institute of Environmental Studies transport model; NIES TM). In particular, the VIC model simulates the land surface hydrology and carbon cycling across a dynamic lake-wetland continuum, while NIES TM models the atmospheric mixing and 3-dimension transport of methane emitted. The VIC model includes a distributed wetland water table scheme, which accounts for microtopography around the lakes and simulates variations in inundated area that are calibrated to match a passive microwave based inundation product. Per-unit-area carbon uptake and methane emissions at the land surface have been calibrated using extensive in situ observations at West Siberia. Also, the atmospheric methane concentration from this linked model run was verified for the recent 5 years with satellite observations from Aqua's Atmospheric Infrared Sounder (AIRS) and Envisat's Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) instruments. Using RCP4.5 and RCP8.5 future climate scenarios, we examine CH4 emissions from high latitude lakes and wetlands, as well as their net greenhouse warming potential, over the next 3 centuries across the Pan-Arctic domain. We also assess relative uncertainties in emissions from each of the sources.

  3. Hydrologic data and groundwater flow simulations in the vicinity of Long Lake, Indiana Dunes National Lakeshore, near Gary, Indiana

    USGS Publications Warehouse

    Lampe, David C.; Bayless, E. Randall

    2013-01-01

    The U.S. Geological Survey (USGS) collected data and simulated groundwater flow to increase understanding of the hydrology and the effects of drainage alterations to the water table in the vicinity of Long Lake, near Gary, Indiana. East Long Lake and West Long Lake (collectively known as Long Lake) make up one of the largest interdunal lakes within the Indiana Dunes National Lakeshore. The National Park Service is tasked with preservation and restoration of wetlands in the Indiana Dunes National Lakeshore along the southern shoreline of Lake Michigan. Urban development and engineering have modified drainage and caused changes in the distribution of open water, streams and ditches, and groundwater abundance and flow paths. A better understanding of the effects these modifications have on the hydrologic system in the area will help the National Park Service, the Gary Sanitary District (GSD), and local stakeholders manage and protect the resources within the study area.This study used hydrologic data and steady-state groundwater simulations to estimate directions of groundwater flow and the effects of various engineering controls and climatic conditions on the hydrology near Long Lake. Periods of relatively high and low groundwater levels were examined and simulated by using MODFLOW and companion software. Simulated hydrologic modifications examined the effects of (1) removing the beaver dams in US-12 ditch, (2) discontinuing seepage of water from the filtration pond east of East Long Lake, (3) discontinuing discharge from US-12 ditch to the GSD sewer system, (4) decreasing discharge from US-12 ditch to the GSD sewer system, (5) connecting East Long Lake and West Long Lake, (6) deepening County Line Road ditch, and (7) raising and lowering the water level of Lake Michigan.Results from collected hydrologic data indicate that East Long Lake functioned as an area of groundwater recharge during October 2002 and a “flow-through” lake during March 2011, with the groundwater divide south of US-12. Wetlands to the south of West Long Lake act as points of recharge to the surficial aquifer in both dry- and wet-weather conditions.Among the noteworthy results from a dry-weather groundwater flow model simulation are (1) US-12 ditch does not receive water from East Long Lake or West Long Lake, (2) the filtration pond at the east end of East Long Lake, when active, contributed approximately 10 percent of the total water entering East Long Lake, and (3) County Line Road ditch has little effect on simulated water level.Among the noteworthy results from a wet-weather groundwater flow simulation are (1) US-12 ditch does not receive water from East Long Lake or West Long Lake, (2) when the seepage from the filtration pond to the surficial aquifer is not active, sources of inflow to East Long Lake are restricted to only precipitation (46 percent of total) and inflow from the surficial aquifer (54 percent of total), and (3) County Line Road ditch bisects the groundwater divide and creates two water-table mounds south of US-12.The results from a series of model scenarios simulating certain engineering controls and changes in Lake Michigan levels include the following: (1) The simulated removal of beaver dams in US-12 ditch during a wet-weather simulation increased discharge from the ditch to the Gary Sanitary system by 13 percent. (2) Discontinuation of seepage from the filtration pond east of East Long Lake decreased discharge from US-12 ditch to the Gary Sanitary system by 2.3 percent. (3) Simulated discontinuation of discharge from the US-12 ditch to the GSD sewer system increased the area where the water table was estimated to be above the land surface beyond the inundated area in the initial wet-weather simulation. (4) Simulated modifications to the control structure at the discharge point of US-12 ditch to the GSD sewer system can decrease discharge by as much as 61 percent while increasing the simulated inundated area during dry weather and decrease discharge as much as 6 percent while increasing the simulated inundated area during wet weather. (5) Deepening of County Line Road ditch can decrease the discharge from US-12 ditch by 26 percent during dry weather and 24 percent during wet weather, as well as decrease the extent of flooded areas south and east of the filtration pond near Ogden Dunes. (7) The increase of the Lake Michigan water level to match the historical maximum can increase the discharge from US-12 ditch by 14 percent during dry weather and by 9.6 percent during wet weather. (8) The decrease of the Lake Michigan water level to match the historical minimum can decrease the discharge from US-12 ditch by 7.4 percent during dry weather and by 3.1 percent during wet weather.The results of this study can be used by water-resource managers to understand how surrounding ditches affect water levels in East and West Long Lake and in the surrounding wetlands and residential areas. The groundwater model developed in this study can be applied in the future to answer questions about how alterations to the drainage system in the area will affect water levels in East and West Long Lake and surrounding areas. The modeling methods developed in this study provide a template for other studies of groundwater flow and groundwater/surface-water interactions within the shallow surficial aquifer in northern Indiana, and in similar hydrologic settings that include surficial sand aquifers in coastal settings.

  4. 30 CFR 783.25 - Cross sections, maps, and plans.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Elevations and locations of monitoring stations used to gather data on water quality and quantity, fish and... aquifers on cross-sections and contour maps; (7) Location of surface water bodies such as streams, lakes... permit area; (9) Location and dimensions of existing areas of spoil, waste, coal development waste, and...

  5. 30 CFR 783.25 - Cross sections, maps, and plans.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Elevations and locations of monitoring stations used to gather data on water quality and quantity, fish and... aquifers on cross-sections and contour maps; (7) Location of surface water bodies such as streams, lakes... permit area; (9) Location and dimensions of existing areas of spoil, waste, coal development waste, and...

  6. 30 CFR 783.25 - Cross sections, maps, and plans.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Elevations and locations of monitoring stations used to gather data on water quality and quantity, fish and... aquifers on cross-sections and contour maps; (7) Location of surface water bodies such as streams, lakes... permit area; (9) Location and dimensions of existing areas of spoil, waste, coal development waste, and...

  7. 30 CFR 783.25 - Cross sections, maps, and plans.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Elevations and locations of monitoring stations used to gather data on water quality and quantity, fish and... aquifers on cross-sections and contour maps; (7) Location of surface water bodies such as streams, lakes... permit area; (9) Location and dimensions of existing areas of spoil, waste, coal development waste, and...

  8. 30 CFR 783.25 - Cross sections, maps, and plans.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Elevations and locations of monitoring stations used to gather data on water quality and quantity, fish and... aquifers on cross-sections and contour maps; (7) Location of surface water bodies such as streams, lakes... permit area; (9) Location and dimensions of existing areas of spoil, waste, coal development waste, and...

  9. Microplastic pollution of lakeshore sediments from remote lakes in Tibet plateau, China.

    PubMed

    Zhang, Kai; Su, Jing; Xiong, Xiong; Wu, Xiang; Wu, Chenxi; Liu, Jiantong

    2016-12-01

    Tibetan Plateau is known as the world's third pole, which is characterized by a low population density with very limited human activities. Tibetan Plateau possesses the greatest numbers of high-altitude inland lakes in the world. However, no information is currently available on the characteristic of microplastic pollution in those lakes within this remote area. In this work, lakeshore sediments from four lakes within the Siling Co basin in northern Tibet were sampled and examined for microplastics (<5 mm). Microplastics were detected in six out of seven sampling sites with abundances ranging from 8 ± 14 to 563 ± 1219 items/m 2 . Riverine input might have contributed to the high abundance of microplastics observed in this remote area. Morphological features suggest that microplastics are derived from the breakdown of daily used plastic products. Polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyvinyl chloride were identified from the microplastic samples using laser Raman spectroscopy, and oxidative and mechanical weathering textures were observed on the surface of microplastics using scanning electron microscope. These results demonstrate the presence of microplastics even for inland lakes in remote areas under very low human impact, and microplastic pollution can be a global issue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Occurrence, compositional distribution, and toxicity assessment of pyrethroid insecticides in sediments from the fluvial systems of Chaohu Lake, Eastern China.

    PubMed

    Wang, Ji-Zhong; Bai, Ya-Shu; Wu, Yakton; Zhang, Shuo; Chen, Tian-Hu; Peng, Shu-Chuan; Xie, Yu-Wei; Zhang, Xiao-Wei

    2016-06-01

    Surface sediment-associated synthetic pyrethroid insecticides (SPs) are known to pose high risks to the benthic organisms in Chaohu Lake, a shallow lake of Eastern China. However, the pollution status of the lake's tributaries and estuaries is still unknown. The present study was conducted to investigate the occurrence, compositional distribution, and toxicity of 12 currently used SPs in the surface sediments from four important tributaries, as well as in the sediment cores at their estuaries, using GC-MS for quantification. All SPs selected were detectable, with cypermethrin, es/fenvalerate, and permethrin dominant in both surface and core sediments, suggesting that these compounds were extensively applied. Urban samples contained the highest summed concentrations of the 12 SPs analyzed (Σ12SP) in both surface and core sediments compared with rural samples, suggesting that urban areas near aquatic environments posed high risks for SPs. The mean concentration of Σ12SP in surface sediments of each river was generally higher than that found in core sediments from its corresponding estuary, perhaps implying recent increases in SP usage. Surface sediments were significantly dominated by cypermethrin and permethrin, whereas core sediments were dominated by permethrin and es/fenvalerate. The compositional distributions demonstrated a spatial variation for surface sediments because urban sediments generally contained greater percentages of permethrin and cypermethrin, but rural sediments had significant levels of es/fenvalerate and cypermethrin. In all sediment cores, the percentage of permethrin gradually increased, whereas es/fenvalerate tended to decrease, from the bottom sediments to the top, indicating that the former represented fresh input, whereas the latter represented historical residue. Most urban samples would be expected to be highly toxic to benthic organisms due to the residue of SPs based on a calculation of toxic units (TUs) using toxicity data of the amphipod Hyalella azteca. However, low TU values were found for the samples from rural areas. These results indicate that the bottom sediments were exposed to high risk largely by the residual SPs from urban areas. The summed TUs were mostly attributable to cypermethrin, followed by λ-cyhalothrin and es/fenvalerate. Despite permethrin contributing ∼28.7 % of the Σ12SP concentration, it only represented 6.34 % of the summed TUs. Therefore, our results suggest that high levels of urbanization can increase the accumulation of SPs in aquatic environments.

  11. Modeling the Sedimentary Infill of Lakes in the East African Rift: A Case Study of Multiple versus Single Rift Basin Segments

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Scholz, C. A.

    2016-12-01

    The sedimentary basins in the East African Rift are considered excellent modern examples for investigating sedimentary infilling and evolution of extensional systems. Some lakes in the western branch of the rift have formed within single-segment systems, and include Lake Albert and Lake Edward. The largest and oldest lakes developed within multi-segment systems, and these include Lake Tanganyika and Lake Malawi. This research aims to explore processes of erosion and sedimentary infilling of the catchment area in single-segment rift (SSR) and multi-segment rift (MSR) systems. We consider different conditions of regional precipitation and evaporation, and assess the resulting facies architecture through forward modeling, using state-of-the-art commercial basin modeling software. Dionisos is a three-dimensional numerical stratigraphic forward modeling software program, which simulates basin-scale sediment transport based on empirical water- and gravity-driven diffusion equations. It was classically used to quantify the sedimentary architecture and basin infilling of both marine siliciclastic and carbonate environments. However, we apply this approach to continental rift basin environments. In this research, two scenarios are developed, one for a MSR and the other for a SSR. The modeled systems simulate the ratio of drainage area and lake surface area observed in modern Lake Tanganyika and Lake Albert, which are examples of MSRs and SSRs, respectively. The main parameters, such as maximum subsidence rate, water- and gravity-driven diffusion coefficients, rainfall, and evaporation, are approximated using these real-world examples. The results of 5 million year model runs with 50,000 year time steps show that MSRs are characterized by a deep water lake with relatively modest sediment accumulation, while the SSRs are characterized by a nearly overfilled lake with shallow water depths and thick sediment accumulation. The preliminary modeling results conform to the features of sedimentary infills revealed by seismic reflection data acquired in Lake Tanganyika and Lake Albert. Future models will refine the parameters of rainfall and evaporation in these two scenarios to better evaluate detailed basin facies architecture.

  12. Impact of land use changes on hydrology of Mt. Kilimanjaro. The case of Lake Jipe catchment

    NASA Astrophysics Data System (ADS)

    Ngugi, Keziah; Ogindo, Harun; Ertsen, Maurits

    2015-04-01

    Mt. Kilimanjaro is an important water tower in Kenya and Tanzania. Land degradation and land use changes have contributed to dwindling surface water resources around Mt. Kilimanjaro. This study focuses on Lake Jipe catchment of about 451Km2 (Ndetei 2011) which is mainly drained by River Lumi, a tributary of river Pangani. River Lumi starts from Mt. Kilimanjaro and flows North east wards to cross the border from Tanzania to Kenya eventually flowing into Lake Jipe which is a trans-boundary lake. The main purpose of this study was to investigate historical land use changes and relate this to reduction in surface water resources. The study will propose measures that could restore the catchment thereby enhancing surface water resources feeding Lake Jipe. A survey was conducted to document community perspectives of historical land use changes. This information was corroborated using Landsat remote sensed images spanning the period 1985-2013 to determine changes in the land cover due to human activities on Lake Jipe Catchment. River Lumi flow data was obtained from Water Resources Management Authority and analyzed for flow trends. The dwindling extent of the Lake was obtained from the community's perspective survey and by Landsat images. Community survey and remote sensing indicated clearing of the forest on the mountain and conversion of the same to crop production fields; damming of river Lumi in Tanzania, conversion of bush land to crop production fields further downstream of river Lumi and irrigation. There is heavy infestation of the invasive species Prosopis juliflora which had aggressively colonized grazing land and blocked irrigation canals. Other land use changes include land fragmentation due to subdivision. Insecure land tenure was blamed for failure by farmers to develop soil and water conservation infrastructure. Available River gauging data showed a general decline in river flow. Heavy flooding occurred during rainy seasons. Towards Lake Jipe after the river gauging station, several springs discharge into river Lumi and the river becomes permanent. The community believes Lake Jipe is a dying lake and will be gone in the coming years unless interventions to save it are implemented. Most of river Lumi water was delivered directly into the lakes outlet, river Ruvu, thus by-passing Lake Jipe. This was due to siltation that blocked river Lumis mouth. Consequently, lake Jipes volume and surface area have reduced dramatically from over the years. Drying of Lake Jipe will affect a lot of people who depend on the lake and the ecosystem. Addressing the problems requires re-afforestation measures and soil and moisture conservation. The severe runoff need to be dammed especially on the Kenyan side to create artificial surface water resources. River Lumi should be trained to discharge into the lake. Land tenure security need to be improved as incentives for proper land utilization. New farming methods to increase land productivity will encourage farmers to practice soil and water conservation measure.

  13. CRT--Cascade Routing Tool to define and visualize flow paths for grid-based watershed models

    USGS Publications Warehouse

    Henson, Wesley R.; Medina, Rose L.; Mayers, C. Justin; Niswonger, Richard G.; Regan, R.S.

    2013-01-01

    The U.S. Geological Survey Cascade Routing Tool (CRT) is a computer application for watershed models that include the coupled Groundwater and Surface-water FLOW model, GSFLOW, and the Precipitation-Runoff Modeling System (PRMS). CRT generates output to define cascading surface and shallow subsurface flow paths for grid-based model domains. CRT requires a land-surface elevation for each hydrologic response unit (HRU) of the model grid; these elevations can be derived from a Digital Elevation Model raster data set of the area containing the model domain. Additionally, a list is required of the HRUs containing streams, swales, lakes, and other cascade termination features along with indices that uniquely define these features. Cascade flow paths are determined from the altitudes of each HRU. Cascade paths can cross any of the four faces of an HRU to a stream or to a lake within or adjacent to an HRU. Cascades can terminate at a stream, lake, or HRU that has been designated as a watershed outflow location.

  14. Soil occupation and atmospheric variations over Sobradinho Lake area. Part two: a regional modeling study

    NASA Astrophysics Data System (ADS)

    Correia, M. F.; da Silva Dias, M. A. F.; da Silva Aragão, M. R.

    2006-11-01

    The impact of the changes on soil cover and land use brought about by the construction of the Sobradinho Dam in the semi-arid region of the São Francisco River Hydrographic Basin is analyzed by means of a numerical model RAMS. Disregarding the influence of a large scale flow, a set of factors were responsible for the creation of a rather complex circulation system that includes mountain-valley winds, lake breeze (LB) and non-conventional circulation all induced by the surface non-homogeneous aspect. Results have demonstrated that the implementation of works of such magnitude brings about environmental changes in an area that stretches far beyond the surroundings of the reservoir. The soil cover alterations due to the ever increasing development of the area with the presence of irrigated crops in a sparsely vegetated region ( caatinga) does affect land surface characteristics, occasioning for that matter the splitting of the available energy into latent and sensible heat fluxes. LB behavior varies in accordance with atmospheric conditions and also in view of the type of vegetation found in the lake surrounding areas. Hydro availability in root zones, even under adverse atmospheric conditions (high temperature and low air humidity) brings up the high rates of evaporation and plant transpiration that contribute towards the increase of humidity and the fall of temperature in lower atmospheric layers.

  15. Measuring Surface Deformation in Glacier Retreated Areas Based on Ps-Insar - Geladandong Glacier as a Case Study

    NASA Astrophysics Data System (ADS)

    Mohamadi, B.; Balz, T.

    2018-04-01

    Glaciers are retreating in many parts of the world as a result of global warming. Many researchers consider Qinghai-Tibetan Plateau as a reference for climate change by measuring glaciers retreat on the plateau. This retreat resulted in some topographic changes in retreated areas, and in some cases can lead to geohazards as landslides, and rock avalanches, which is known in glacier retreated areas as paraglacial slope failure (PSF). In this study, Geladandong biggest and main glacier mass was selected to estimate surface deformation on its glacier retreated areas and define potential future PSF based on PS-InSAR technique. 56 ascending and 49 descending images were used to fulfill this aim. Geladandong glacier retreated areas were defined based on the maximum extent of the glacier in the little ice age. Results revealed a general uplift in the glacier retreated areas with velocity less than 5mm/year. Obvious surface motion was revealed in seven parts surround glacier retreated areas with high relative velocity reached ±60mm/year in some parts. Four parts were considered as PSF potential motion, and two of them showed potential damage for the main road in the study area in case of rock avalanche into recent glacier lakes that could result in glacier lake outburst flooding heading directly to the road. Finally, further analysis and field investigations are needed to define the main reasons for different types of deformation and estimate future risks of these types of surface motion in the Qinghai-Tibetan Plateau.

  16. Estimating ground-water inflow to lakes in central Florida using the isotope mass-balance approach

    USGS Publications Warehouse

    Sacks, Laura A.

    2002-01-01

    The isotope mass-balance approach was used to estimate ground-water inflow to 81 lakes in the central highlands and coastal lowlands of central Florida. The study area is characterized by a subtropical climate and numerous lakes in a mantled karst terrain. Ground-water inflow was computed using both steady-state and transient formulations of the isotope mass-balance equation. More detailed data were collected from two study lakes, including climatic, hydrologic, and isotopic (hydrogen and oxygen isotope ratio) data. For one of these lakes (Lake Starr), ground-water inflow was independently computed from a water-budget study. Climatic and isotopic data collected from the two lakes were similar even though they were in different physiographic settings about 60 miles apart. Isotopic data from all of the study lakes plotted on an evaporation trend line, which had a very similar slope to the theoretical slope computed for Lake Starr. These similarities suggest that data collected from the detailed study lakes can be extrapolated to the rest of the study area. Ground-water inflow computed using the isotope mass-balance approach ranged from 0 to more than 260 inches per year (or 0 to more than 80 percent of total inflows). Steady-state and transient estimates of ground-water inflow were very similar. Computed ground-water inflow was most sensitive to uncertainty in variables used to calculate the isotopic composition of lake evaporate (isotopic compositions of lake water and atmospheric moisture and climatic variables). Transient results were particularly sensitive to changes in the isotopic composition of lake water. Uncertainty in ground-water inflow results is considerably less for lakes with higher ground-water inflow than for lakes with lower ground-water inflow. Because of these uncertainties, the isotope mass-balance approach is better used to distinguish whether ground-water inflow quantities fall within certain ranges of values, rather than for precise quantification. The lakes fit into three categories based on their range of ground-water inflow: low (less than 25 percent of total inflows), medium (25-50 percent of inflows), and high (greater than 50 percent of inflows). The majority of lakes in the coastal lowlands had low ground-water inflow, whereas the majority of lakes in the central highlands had medium to high ground-water inflow. Multiple linear regression models were used to predict ground-water inflow to lakes. These models help identify basin characteristics that are important in controlling ground-water inflow to Florida lakes. Significant explanatory variables include: ratio of basin area to lake surface area, depth to the Upper Floridan aquifer, maximum lake depth, and fraction of wetlands in the basin. Models were improved when lake water-quality data (nitrate, sodium, and iron concentrations) were included, illustrating the link between ground-water geochemistry and lake chemistry. Regression models that considered lakes within specific geographic areas were generally poorer than models for the entire study area. Regression results illustrate how more simplified models based on basin and lake characteristics can be used to estimate ground-water inflow. Although the uncertainty in the amount of ground-water inflow to individual lakes is high, the isotope mass-balance approach was useful in comparing the range of ground-water inflow for numerous Florida lakes. Results were also helpful in understanding differences in the geographic distribution of ground-water inflow between the coastal lowlands and central highlands. In order to use the isotope mass-balance approach to estimate inflow for multiple lakes, it is essential that all the lakes are sampled during the same time period and that detailed isotopic, hydrologic, and climatic data are collected over this same period of time. Isotopic data for Florida lakes can change over time, both seasonally and interannually, primarily because of differ

  17. An evaluation of effects of groundwater exchange on nearshore habitats and water quality of western Lake Erie

    USGS Publications Warehouse

    Haack, Sheridan K.; Neff, Brian P.; Rosenberry, Donald O.; Savino, Jacqueline F.; Lundstrom, Scott C.

    2005-01-01

    Historically, the high potentiometric surface of groundwater in the Silurian/Devonian carbonate aquifer in Monroe County, MI resulted in discharge of highly mineralized, SO4-rich groundwater to the Lake Erie shoreline near both Erie State Game Area (ESGA) and Pointe Mouillee State Game Area (PMSGA). Recently, regional groundwater levels near PMSGA have been drawn down as much as 45 m below lake level in apparent response to quarry dewatering. From August to November of 2003, we conducted preliminary studies of groundwater flow dynamics and chemistry, shallow lake water chemistry, and fish and invertebrate communities at both sites. Consistent with regional observations, groundwater flow direction in the nearshore at ESGA was upward, or toward Lake Erie, and shallow nearshore groundwater chemistry was influenced by regional groundwater chemistry. In contrast, at PMSGA, the groundwater flow potential was downward and lake water, influenced by quarry discharge seeping downward into nearshore sediments, produced a different lake and shallow groundwater chemistry than at ESGA. Although the invertebrate and young fish community was similar at the two sites, taxonomic groups tolerant of degraded water quality were more prevalent at PMSGA. Sensitive taxa were more prevalent at ESGA. We propose a conceptual model, based on well-described models of groundwater/seawater interaction along coastal margins, to describe the interconnection among geologic, hydrologic, chemical, and biological processes in the different nearshore habitats of Lake Erie, and we identify processes that warrant further detailed study in the Great Lakes.

  18. A Multiscale Surface Water Temperature Data Acquisition Platform: Tests on Lake Geneva, Switzerland

    NASA Astrophysics Data System (ADS)

    Barry, D. A.; Irani Rahaghi, A.; Lemmin, U.; Riffler, M.; Wunderle, S.

    2015-12-01

    An improved understanding of surface transport processes is necessary to predict sediment, pollutant and phytoplankton patterns in large lakes. Lake surface water temperature (LSWT), which varies in space and time, reflects meteorological and climatological forcing more than any other physical lake parameter. There are different data sources for LSWT mapping, including remote sensing and in situ measurements. Satellite data can be suitable for detecting large-scale thermal patterns, but not meso- or small scale processes. Lake surface thermography, investigated in this study, has finer resolution compared to satellite images. Thermography at the meso-scale provides the ability to ground-truth satellite imagery over scales of one to several satellite image pixels. On the other hand, thermography data can be used as a control in schemes to upscale local measurements that account for surface energy fluxes and the vertical energy budget. Independently, since such data can be collected at high frequency, they can be also useful in capturing changes in the surface signatures of meso-scale eddies and thus to quantify mixing processes. In the present study, we report results from a Balloon Launched Imaging and Monitoring Platform (BLIMP), which was developed in order to measure the LSWT at meso-scale. The BLIMP consists of a small balloon that is tethered to a boat and equipped with thermal and RGB cameras, as well as other instrumentation for location and communication. Several deployments were carried out on Lake Geneva. In a typical deployment, the BLIMP is towed by a boat, and collects high frequency data from different heights (i.e., spatial resolutions) and locations. Simultaneous ground-truthing of the BLIMP data is achieved using an autonomous craft that collects a variety of data, including in situ surface/near surface temperatures, radiation and meteorological data in the area covered by the BLIMP images. With suitable scaling, our results show good consistency between in situ, BLIMP and concurrent satellite data. In addition, the BLIMP thermography reveals (hydrodynamically-driven) structures in the LSWT - an obvious example being mixing of river discharges.

  19. Comparison of MTI Satellite-Derived Surface Water Temperatures and In-Situ Measurements

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kurzeja, R.

    2001-07-26

    Temperatures of the water surface of a cold, mid-latitude lake and the tropical Pacific Ocean were determined from MTI images and from in situ concurrent measurements. In situ measurements were obtained at the time of the MTI image with a floating, anchored platform, which measured the surface and bulk water temperatures and relevant meteorological variables, and also from a boat moving across the target area. Atmospheric profiles were obtained from concurrent radiosonde soundings. Radiances at the satellite were calculated with the Modtran radiative transfer model. The MTI infrared radiances were within 1 percent of the calculated values at the Pacificmore » Ocean site but were 1-2 percent different over the mid-latitude lake.« less

  20. Characterizing the Fate and Mobility of Phosphorus in Utah Lake Sediments

    NASA Astrophysics Data System (ADS)

    Randall, M.; Carling, G. T.; Nelson, S.; Bickmore, B.; Miller, T.

    2016-12-01

    An increasing number of lakes worldwide are impacted by eutrophication and harmful algal blooms due to nutrient inputs. Utah Lake, located in northern Utah, is a eutrophic freshwater lake that is unique because it is naturally shallow, turbid, and alkaline with high dissolved oxygen levels. Recently, the Utah Division of Water Quality has proposed a new rule to limit phosphorus (P) loading to Utah Lake from wastewater treatment plants in an effort to mitigate eutrophication. However, reducing external P loads may not lead to immediate improvements in water quality due to the legacy pool of nutrients in lake sediments. The purpose of this study is to characterize the fate and mobility of P in Utah Lake to better understand P cycling in this unique system. We analyzed P speciation, mineralogy, and binding capacity in lake sediment samples collected from 9 locations across Utah Lake. P concentrations in sediment ranged from 1120 to 1610 ppm, with highest concentrations in Provo Bay near the major metropolitan area. Likewise, P concentrations in sediment pore water were highest in Provo Bay with concentrations up to 4 mg/L. Sequential leach tests indicate that 30-45% of P is bound to apatite and another 40-55% is adsorbed onto the surface of redox sensitive Fe/Mn hydroxides. This was confirmed by SEM images, which showed the highest P concentrations correlating with both Ca (apatite) and Fe (Fe hydroxides). The apatite-bound P fraction is likely immobile, but the P fraction sorbed to Fe/Mn hydroxides is potentially bioavailable under changing redox conditions. Batch sorption results indicate that lake sediments have a high capacity to absorb and remove P from the water column, with an average uptake of 70-96% of P from spiked surface water with concentrations ranging from 1-10 mg/L. Mineral precipitation and sorption to bottom sediments is an efficient removal mechanism of P in Utah Lake, but a significant portion of P may be available for resuspension and cycling in surface waters. Mitigating lake eutrophication is a complex problem that goes beyond reducing nutrient loads to the water body and requires a better understanding of internal P cycling.

  1. Supraglacial lakes on Himalayan debris-covered glacier (Invited)

    NASA Astrophysics Data System (ADS)

    Sakai, A.; Fujita, K.

    2013-12-01

    Debris-covered glaciers are common in many of the world's mountain ranges, including in the Himalayas. Himalayan debris-covered glacier also contain abundant glacial lakes, including both proglacial and supraglacial types. We have revealed that heat absorption through supraglacial lakes was about 7 times greater than that averaged over the whole debris-covered zone. The heat budget analysis elucidated that at least half of the heat absorbed through the water surface was released with water outflow from the lakes, indicating that the warm water enlarge englacial conduits and produce internal ablation. We observed some portions at debris-covered area has caved at the end of melting season, and ice cliff has exposed at the side of depression. Those depression has suggested that roof of expanded water channels has collapsed, leading to the formation of ice cliffs and new lakes, which would accelerate the ablation of debris-covered glaciers. Almost glacial lakes on the debris-covered glacier are partially surrounded by ice cliffs. We observed that relatively small lakes had non-calving, whereas, calving has occurred at supraglacial lakes with fetch larger than 80 m, and those lakes expand rapidly. In the Himalayas, thick sediments at the lake bottom insulates glacier ice and lake water, then the lake water tends to have higher temperature (2-4 degrees C). Therefore, thermal undercutting at ice cliff is important for calving processes in the glacial lake expansion. We estimated and subaqueous ice melt rates during the melt and freeze seasons under simple geomorphologic conditions. In particular, we focused on valley wind-driven water currents in various fetches during the melt season. Our results demonstrate that the subaqueous ice melt rate exceeds the ice-cliff melt rate above the water surface when the fetch is larger than 20 m with the water temperature of 2-4 degrees C. Calculations suggest that onset of calving due to thermal undercutting is controlled by water currents driven by winds at the lake surface with a positive feedback process. The risk of GLOFs (glacial lake outburst flood) are analysed for Himalayan glacial lakes. We proposed an objective index for GLOF probability, based on depression angle from the lakeshore, which allows the lakes to be assessed using remotely sensed digital elevation models (DEMs). The index was verified by pre-GLOF topography derived by spy satellite imageries. We screened 2800 Himalayan glacial lakes and identified 49 lakes with potential flood volumes over 10 million m3.

  2. Pronounced chemical response of Subarctic lakes to climate-driven losses in surface area

    USGS Publications Warehouse

    Lewis, Tyler L.; Lindberg, Mark S.; Schmutz, Joel A.; Heglund, Patricia J.; Rover, Jennifer R.; Koch, Joshua C.; Bertram, Mark R.

    2015-01-01

    Losses in lake area have been observed for several Arctic and Subarctic regions in recent decades, with unknown consequences for lake ecosystems. These reductions are primarily attributed to two climate-sensitive mechanisms, both of which may also cause changes in water chemistry: (i) increased imbalance of evaporation relative to inflow, whereby increased evaporation and decreased inflow act to concentrate solutes into smaller volumes; and (ii) accelerated permafrost degradation, which enhances sublacustrine drainage while simultaneously leaching previously frozen solutes into lakes. We documented changes in nutrients [total nitrogen (TN), total phosphorus (TP)] and ions (calcium, chloride, magnesium, sodium) over a 25 year interval in shrinking, stable, and expanding Subarctic lakes of the Yukon Flats, Alaska. Concentrations of all six solutes increased in shrinking lakes from 1985–1989 to 2010–2012, while simultaneously undergoing little change in stable or expanding lakes. This created a present-day pattern, much weaker or absent in the 1980s, in which shrinking lakes had higher solute concentrations than their stable or expanding counterparts. An imbalanced evaporation-to-inflow ratio (E/I) was the most likely mechanism behind such changes; all four ions, which behave semiconservatively and are prone to evapoconcentration, increased in shrinking lakes and, along with TN and TP, were positively related to isotopically derived E/I estimates. Moreover, the most conservative ion, chloride, increased >500% in shrinking lakes. Conversely, only TP concentration was related to probability of permafrost presence, being highest at intermediate probabilities. Overall, the substantial increases of nutrients (TN >200%, TP >100%) and ions (>100%) may shift shrinking lakes towards overly eutrophic or saline states, with potentially severe consequences for ecosystems of northern lakes.

  3. Chemical and biological status of lakes and streams in the upper midwest: assessment of acidic deposition effects

    USGS Publications Warehouse

    Wiener, J.G.; Eilers, J.M.

    1987-01-01

    Many lakes in three areas in the Upper Midwest - northeastern Minnesota, northern Wisconsin, and the Upper Peninsula of Michigan - have low acid neutralizing capacity (ANC) and may be susceptible to change by acidic deposition. Northcentral Wisconsin and the Upper Peninsula of Michigan together contain about 150-300 acidic lakes (ANC ≤ 0), whereas none have been found in Minnesota. These acidic lakes are precipitation-dominated, Clearwater seepage lakes having small surface area, shallow depth, and low concentrations of dissolved organic carbon. The spatial distribution of these acidic lakes parallels a west to east gradient of increasing sulfate and hydrogen ion deposition. Several of these acidic lakes exhibit chemical characteristics and biological changes consistent with those observed elsewhere in waters reported to be acidified by acidic deposition. However, an hypothesis of recent lake acidification is not supported by analyses of either historical chemical data or diatom remains in lake sediments, and natural sources of acidity and alternative ecological processes have not been conclusively eliminated as causative factors. Streams in this three-state region have high ANC and appear to be insensitive to acidic deposition. The species richness and composition of lacustrine fish communities in the region are partly related to pH and associated chemical factors. Sport fishes considered acid-sensitive and of primary concern with regard to acidification include walleye, smallmouth bass, and black crappie. The fishery in at least one lake, Morgan Lake in Wisconsin (pH 4.6), may have declined because of acidification. Given the general lack of quantitative fishery data for acidic Wisconsin and Michigan lakes, however, more general conclusions concerning impacts or the absence of impacts of acidification on the region's fishery resources are not possible.

  4. Water level monitoring using radar remote sensing data: Application to Lake Kivu, central Africa

    NASA Astrophysics Data System (ADS)

    Munyaneza, Omar; Wali, Umaru G.; Uhlenbrook, Stefan; Maskey, Shreedhar; Mlotha, McArd J.

    Satellite radar altimetry measures the time required for a pulse to travel from the satellite antenna to the earth’s surface and back to the satellite receiver. Altimetry on inland lakes generally shows some deviation from in situ level measurements. The deviation is attributed to the geographically varying corrections applied to account for atmospheric effects on radar waves. This study was focused on verification of altimetry data for Lake Kivu (2400 km 2), a large inland lake between Rwanda and the Democratic Republic of Congo (DRC) and estimating the lake water levels using bathymetric data combined with satellite images. Altimetry data obtained from ENVISAT and ERS-2 satellite missions were compared with water level data from gauging stations for Lake Kivu. Gauge data for Lake Kivu were collected from the stations ELECTROGAZ and Rusizi. ENVISAT and ERS-2 data sets for Lake Kivu are in good agreement with gauge data having R2 of 0.86 and 0.77, respectively. A combination of the two data sets improved the coefficient of determination to 95% due to the improved temporal resolution of the data sets. The calculated standard deviation for Lake Kivu water levels was 0.642 m and 0.701 m, for ENVISAT and ERS-2 measurements, respectively. The elevation-surface area characteristics derived from bathymetric data in combination with satellite images were used to estimate the lake level gauge. Consequently, the water level of Lake Kivu could be estimated with an RMSE of 0.294 m and an accuracy of ±0.58 m. In situations where gauges become malfunctioning or inaccessible due to damage or extreme meteorological events, the method can be used to ensure data continuity.

  5. Estimating future temperature maxima in lakes across the United States using a surrogate modeling approach

    PubMed Central

    Zi, Tan; Schmidt, Michelle; Johnson, Thomas E.; Nover, Daniel M.; Clark, Christopher M.

    2017-01-01

    A warming climate increases thermal inputs to lakes with potential implications for water quality and aquatic ecosystems. In a previous study, we used a dynamic water column temperature and mixing simulation model to simulate chronic (7-day average) maximum temperatures under a range of potential future climate projections at selected sites representative of different U.S. regions. Here, to extend results to lakes where dynamic models have not been developed, we apply a novel machine learning approach that uses Gaussian Process regression to describe the model response surface as a function of simplified lake characteristics (depth, surface area, water clarity) and climate forcing (winter and summer air temperatures and potential evapotranspiration). We use this approach to extrapolate predictions from the simulation model to the statistical sample of U.S. lakes in the National Lakes Assessment (NLA) database. Results provide a national-scale scoping assessment of the potential thermal risk to lake water quality and ecosystems across the U.S. We suggest a small fraction of lakes will experience less risk of summer thermal stress events due to changes in stratification and mixing dynamics, but most will experience increases. The percentage of lakes in the NLA with simulated 7-day average maximum water temperatures in excess of 30°C is projected to increase from less than 2% to approximately 22% by the end of the 21st century, which could significantly reduce the number of lakes that can support cold water fisheries. Site-specific analysis of the full range of factors that influence thermal profiles in individual lakes is needed to develop appropriate adaptation strategies. PMID:29121058

  6. Spatial Distribution and Fuzzy Health Risk Assessment of Trace Elements in Surface Water from Honghu Lake.

    PubMed

    Li, Fei; Qiu, Zhenzhen; Zhang, Jingdong; Liu, Chaoyang; Cai, Ying; Xiao, Minsi

    2017-09-04

    Previous studies revealed that Honghu Lake was polluted by trace elements due to anthropogenic activities. This study investigated the spatial distribution of trace elements in Honghu Lake, and identified the major pollutants and control areas based on the fuzzy health risk assessment at screening level. The mean total content of trace elements in surface water decreased in the order of Zn (18.04 μg/L) > Pb (3.42 μg/L) > Cu (3.09 μg/L) > Cr (1.63 μg/L) > As (0.99 μg/L) > Cd (0.14 μg/L), within limits of Drinking Water Guidelines. The results of fuzzy health risk assessment indicated that there was no obvious non-carcinogenic risk to human health, while carcinogenic risk was observed in descending order of As > Cr > Cd > Pb. As was regarded to have the highest carcinogenic risk among selected trace elements because it generally accounted for 64% of integrated carcinogenic risk. Potential carcinogenic risk of trace elements in each sampling site was approximately at medium risk level (10 -5 to 10 -4 ). The areas in the south (S4, S13, and S16) and northeast (S8, S18, and S19) of Honghu Lake were regarded as the risk priority control areas. However, the corresponding maximum memberships of integrated carcinogenic risk in S1, S3, S10-S13, S15, and S18 were of relatively low credibility (50-60%), and may mislead the decision-makers in identifying the risk priority areas. Results of fuzzy assessment presented the subordinate grade and corresponding reliability of risk, and provided more full-scale results for decision-makers, which made up for the deficiency of certainty assessment to a certain extent.

  7. Spatial Distribution and Fuzzy Health Risk Assessment of Trace Elements in Surface Water from Honghu Lake

    PubMed Central

    Qiu, Zhenzhen; Zhang, Jingdong; Liu, Chaoyang; Cai, Ying; Xiao, Minsi

    2017-01-01

    Previous studies revealed that Honghu Lake was polluted by trace elements due to anthropogenic activities. This study investigated the spatial distribution of trace elements in Honghu Lake, and identified the major pollutants and control areas based on the fuzzy health risk assessment at screening level. The mean total content of trace elements in surface water decreased in the order of Zn (18.04 μg/L) > Pb (3.42 μg/L) > Cu (3.09 μg/L) > Cr (1.63 μg/L) > As (0.99 μg/L) > Cd (0.14 μg/L), within limits of Drinking Water Guidelines. The results of fuzzy health risk assessment indicated that there was no obvious non-carcinogenic risk to human health, while carcinogenic risk was observed in descending order of As > Cr > Cd > Pb. As was regarded to have the highest carcinogenic risk among selected trace elements because it generally accounted for 64% of integrated carcinogenic risk. Potential carcinogenic risk of trace elements in each sampling site was approximately at medium risk level (10−5 to 10−4). The areas in the south (S4, S13, and S16) and northeast (S8, S18, and S19) of Honghu Lake were regarded as the risk priority control areas. However, the corresponding maximum memberships of integrated carcinogenic risk in S1, S3, S10–S13, S15, and S18 were of relatively low credibility (50–60%), and may mislead the decision-makers in identifying the risk priority areas. Results of fuzzy assessment presented the subordinate grade and corresponding reliability of risk, and provided more full-scale results for decision-makers, which made up for the deficiency of certainty assessment to a certain extent. PMID:28869576

  8. Trends in Surface Water Chemistry in Acidified Areas in Europe and North America from 1990 to 2008

    EPA Science Inventory

    Acidification of lakes and rivers is still an environmental concern despite reduced emissions of acidifying compounds. We analyzed trends in surface water chemistry of 173 acid-sensitive sites from 12 regions in Europe and North America. In 11 of 12 regions, non-marine sulphate (...

  9. Anthropogenic climate change has altered primary productivity in Lake Superior

    PubMed Central

    O'Beirne, M. D.; Werne, J. P.; Hecky, R. E.; Johnson, T. C.; Katsev, S.; Reavie, E. D.

    2017-01-01

    Anthropogenic climate change has the potential to alter many facets of Earth's freshwater resources, especially lacustrine ecosystems. The effects of anthropogenic changes in Lake Superior, which is Earth's largest freshwater lake by area, are not well documented (spatially or temporally) and predicted future states in response to climate change vary. Here we show that Lake Superior experienced a slow, steady increase in production throughout the Holocene using (paleo)productivity proxies in lacustrine sediments to reconstruct past changes in primary production. Furthermore, data from the last century indicate a rapid increase in primary production, which we attribute to increasing surface water temperatures and longer seasonal stratification related to longer ice-free periods in Lake Superior due to anthropogenic climate warming. These observations demonstrate that anthropogenic effects have become a prominent influence on one of Earth's largest, most pristine lacustrine ecosystems. PMID:28598413

  10. Anthropogenic climate change has altered primary productivity in Lake Superior.

    PubMed

    O'Beirne, M D; Werne, J P; Hecky, R E; Johnson, T C; Katsev, S; Reavie, E D

    2017-06-09

    Anthropogenic climate change has the potential to alter many facets of Earth's freshwater resources, especially lacustrine ecosystems. The effects of anthropogenic changes in Lake Superior, which is Earth's largest freshwater lake by area, are not well documented (spatially or temporally) and predicted future states in response to climate change vary. Here we show that Lake Superior experienced a slow, steady increase in production throughout the Holocene using (paleo)productivity proxies in lacustrine sediments to reconstruct past changes in primary production. Furthermore, data from the last century indicate a rapid increase in primary production, which we attribute to increasing surface water temperatures and longer seasonal stratification related to longer ice-free periods in Lake Superior due to anthropogenic climate warming. These observations demonstrate that anthropogenic effects have become a prominent influence on one of Earth's largest, most pristine lacustrine ecosystems.

  11. Fluorescent components and spatial patterns of chromophoric dissolved organic matters in Lake Taihu, a large shallow eutrophic lake in China.

    PubMed

    Yao, Bo; Hu, Chunming; Liu, Qingquan

    2016-11-01

    Water samples at both surface and bottom layers were taken from 102 sites in Lake Taihu to study the fluorescent components and spatial patterns of chromophoric dissolved organic matters (CDOM). Three-dimensional excitation-emission matrix data obtained from the samples were analyzed by parallel factor approach in which four humic-like and two protein-like fluorescent components (named C1-C6) were identified. The results showed that fluorescence intensities were higher in the northern and western lake regions, and notable declines of fluorescence maxima (F max ) were observed from the northwest to the center and then to the southeast of the lake. Calculated biological index (BIX) values ranged from 0.88 to 1.44 and humification index (HIX) values from 0.64 to 3.37 for all the samples. The spatial variations of BIX and HIX values suggested stronger allochthonous CDOM characteristics in Zhushan Bay and the western area and autochthonous characteristics in the southern and eastern areas. Vertically, the average F max value of the surface samples was about 6 % less than that of the bottom samples, but noticeable variations existed among different sampling sites and components. These distribution characteristics of CDOM were mainly attributed to the spatial heterogeneity of sources and wind-induced transportation process. Interestingly, the C6 component (Ex max /Em max  = 250/455 nm) seemed to be unique in samples from Zhushan Bay and probably resulted from the discharge of the Taige River. Therefore, it could be used as an indicator of point-source discharge and a tracer to study the fate of CDOM in the lake.

  12. Water Quality Investigations at Lake Merritt in Oakland, California

    NASA Astrophysics Data System (ADS)

    Carter, G.; Casino, C.; Johnson, K.; Huang, J.; Le, A.; Truisi, V. M.; Turner, D.; Yanez, F.; Yu, J. F.; Unigarro, M.; Vue, G.; Garduno, L.; Cuff, K.

    2005-12-01

    Lake Merritt is a saltwater tidal lagoon that forms a portion of a wildlife refuge in downtown Oakland, California. The general area was designated as the nation's first wildlife refuge in 1869, and is currently the home to over 90 species of migrating waterfowl, as well as a variety of aquatic wildlife. Situated within an area composed of compacted marine sediment located near the center of Oakland, Lake Merritt also serves as a major local catchment basin, receiving significant urban runoff from a 4,650 acre local watershed through 60 storm drains and four culverted creeks. Due to factors related to its geographical location, Lake Merritt has suffered from poor water quality at various times throughout its history. In fact, in May of 1999 the US Environmental Protection Agency designated Lake Merritt as a body of water whose beneficial uses are impaired, mainly due to high levels of trash and low levels of dissolved oxygen. As a contribution to continuing efforts to monitor and assess water quality of the Lake, we began a water quality investigation during the Summer of 2005, which included the measurement of dissolved oxygen concentrations of samples collected near its surface at over 85 different locations. These measurements were made using a sensor attached to a PASCO data- logger. The sensor measures the electric current produced by a chemical reaction in its probe, which is composed of a platinum cathode and a silver anode surrounded by an electrolyte solution. Results of these measurements were statistically analyzed, mapped, and then used in assessing the quality of Lake Merritt's water, particularly in relation to supporting aquatic biota. Preliminary analysis of results obtained so far indicates that the highest quality waters in Lake Merritt occur in areas that are closest to a source of San Francisco Bay water, as well as those areas nearby where water circulation is robust. Significantly high levels of dissolved oxygen were measured in an area that has the greatest number and diversity of organisms as indicated through visual observation, which is located where marine waters flow directly into the Lake. In addition, high levels of dissolved oxygen were measured at two sites along an approximately 500 meters stretch of the Lake's eastern shoreline, where swift moving currents were observed. Dissolved oxygen levels were lowest in areas where storm drain runoff waters flow into the Lake, as well as those that include trash-filled, stagnant sections. Overall, our work has generated information that may be used to better understand important factors that affect Lake Merritt's water quality. Such studies should be continued in the future and used to help maintain a healthy ecosystem in and around Lake Merritt.

  13. Microbial communities of Hyper saline Lake Salda and Acigol, SW Turkey and Their effects on Biogeochemical cycles

    NASA Astrophysics Data System (ADS)

    Balci, N.; Karaguler, N. G.; Ece, I.; Romanek, C.

    2009-12-01

    The modern lakes Acigol and Salda, located in the “Lake District” of SW of Turkey, are known for the precipitation of sodium, magnesium, and potassium salts, and Mg-rich carbonate, respectively. As an analogue to extraterrestrial environments, these lakes provide opportunities to study microbe-mineral interactions in extreme environments, and in turn to better understand biogeochemical conditions in such environments. Lake Salda is an evaporatic alkaline lake (pH: 9) that covers an area of about 45 km2 in a partially serpentinized ophiolitic rocks. Water samples collected from the surface contain c. 295 mg/L Mg and c. 190 mg/L Na at a pH of 9.1, while the stream entering the lake (pH range 7-9.5) had values of 55 mg/L and 3 mg/L, respectively, indicating significant Na enrichment relative to Mg in the lake. Microbiological analyses of sediment samples from the stream and the lake indicate a diverse microbial community. Lake Acigol is a perennial lake with a maximum salinity of about 200 g/L and covers an area of 55-60 km2 . Water samples were taken from the lake and ponds around the lake in addition to sediment samples. The water chemistry revealed relatively high Na and SO4 concentrations both in the lake (30 gr/L, 33.36 gr/L), and the ponds (100 mg/L, 123 mg/L). The mineralogical analyses of sediments showed gypsum, halite, carbonate (aragonite, huntite) precipitation in the lake and ponds. The geochemical and microbiological data from both lakes suggest that the metabolic activity of microorganisms (cyanobacteria, sulfate reducing bacteria) significantly affect the surrounding microenvironment, overcoming the common kinetic inhibitors to carbonate mineral precipitation by raising the pH and Mg- and HCO3-ion concentration, and by reducing sulfate ion concentration of the waters. We are currently undertaking laboratory experiments to elucidate biological influences on the precipitation of carbonate minerals under field conditions.

  14. Concentrations, Trends, and Air-Water Exchange of PAHs and PBDEs Derived from Passive Samplers in Lake Superior in 2011.

    PubMed

    Ruge, Zoe; Muir, Derek; Helm, Paul; Lohmann, Rainer

    2015-12-01

    Polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenylethers (PBDEs) are both currently released into the environment from anthropogenic activity. Both are hence primarily associated with populated or industrial areas, although wildfires can be an important source of PAHs, as well. Polyethylene passive samplers (PEs) were simultaneously deployed in surface water and near surface atmosphere to determine spatial trends and air-water gaseous exchange of 21 PAHs and 11 PBDEs at 19 sites across Lake Superior in 2011. Surface water and atmospheric PAH concentrations were greatest at urban sites (up to 65 ng L(-1) and 140 ng m(-3), respectively, averaged from June to October). Near populated regions, PAHs displayed net air-to-water deposition, but were near equilibrium off-shore. Retene, probably depositing following major wildfires in the region, dominated dissolved PAH concentrations at most Lake Superior sites. Atmospheric and dissolved PBDEs were greatest near urban and populated sites (up to 6.8 pg L(-1) and 15 pg m(-3), respectively, averaged from June to October), dominated by BDE-47. At most coastal sites, there was net gaseous deposition of BDE-47, with less brominated congeners contributing to Sault Ste. Marie and eastern open lake fluxes. Conversely, the central open lake and Eagle Harbor sites generally displayed volatilization of PBDEs into the atmosphere, mainly BDE-47.

  15. Surface-exposure ages of Front Range moraines that may have formed during the Younger Dryas, 8.2 cal ka, and Little Ice Age events

    USGS Publications Warehouse

    Benson, L.; Madole, R.; Kubik, P.; McDonald, R.

    2007-01-01

    Surface-exposure (10Be) ages have been obtained on boulders from three post-Pinedale end-moraine complexes in the Front Range, Colorado. Boulder rounding appears related to the cirque-to-moraine transport distance at each site with subrounded boulders being typical of the 2-km-long Chicago Lakes Glacier, subangular boulders being typical of the 1-km-long Butler Gulch Glacier, and angular boulders being typical of the few-hundred-m-long Isabelle Glacier. Surface-exposure ages of angular boulders from the Isabelle Glacier moraine, which formed during the Little Ice Age (LIA) according to previous lichenometric dating, indicate cosmogenic inheritance values ranging from 0 to ???3.0 10Be ka.11Surface-exposure ages in this paper are labeled 10Be; radiocarbon ages are labeled 14C ka, calendar and calibrated radiocarbon ages are labeled cal ka, and layer-based ice-core ages are labeled ka. 14C ages, calibrated 14C ages, and ice core ages are given relative to AD 1950, whereas 10Be ages are given relative to the sampling date. Radiocarbon ages were calibrated using CALIB 5.01 and the INTCAL04 data base Stuiver et al. (2005). Ages estimated using CALIB 5.01 are shown in terms of their 1-sigma range. Subangular boulders from the Butler Gulch end moraine yielded surface-exposure ages ranging from 5 to 10.2 10Be ka. We suggest that this moraine was deposited during the 8.2 cal ka event, which has been associated with outburst floods from Lake Agassiz and Lake Ojibway, and that the large age range associated with the Butler Gulch end moraine is caused by cosmogenic shielding of and(or) spalling from boulders that have ages in the younger part of the range and by cosmogenic inheritance in boulders that have ages in the older part of the range. The surface-exposure ages of eight of nine subrounded boulders from the Chicago Lakes area fall within the 13.0-11.7 10Be ka age range, and appear to have been deposited during the Younger Dryas interval. The general lack of inheritance in the eight samples probably stems from the fact that only a few thousand years intervened between the retreat of the Pinedale glacier and the advance of the Chicago Lakes glacier; in addition, bedrock in the Chicago Lakes cirque area may have remained covered with snow and ice during that interval, thus partially shielding the bedrock from cosmogenic radiation.

  16. Analysis of High Resolution Satellite imagery to acsees Glacier Mass Balance and Lake Hazards in Sikkim Himalayas

    NASA Astrophysics Data System (ADS)

    Bhushan, S.; Shean, D. E.; Haritashya, U. K.; Arendt, A. A.; Syed, T. H.; Setiawan, L.

    2017-12-01

    Glacial lake outburst floods can impact downstream communities due to the sudden outflux of huge quantities of stored water. In this study, we develop a hazard assessment of the moraine dammed glacial lakes in Sikkim Himalayas by analyzing the morphometry of proglacial features, and the surface velocity and mass balance of glaciers. We generated high-resolution digital elevation models (DEMs) using the open-source NASA Ames Stereo Pipeline (ASP) and use other open-source tools to calculate surface velocity and patterns of glacier downwasting over time. Geodetic glacier mass balance is obtained for three periods using high-resolution WorldView/GeoEye stereo DEMs (8 m posting, 2014-2016), Cartosat-1 stereo DEMs (10 m, 2006-2008) and SRTM (30 m, 2000). Initial results reveal a region-wide mass balance of -0.31±0.13 m w.eq.a-1 for the 2007-2015 period, with some debris covered glaciers showing a very low mass loss rate. Additionally, 12 annual glacier velocity fields spanning from 1991 to 2017.derived from Landsat imagery are used to explore the relationship between glacier dynamics and changes in proglacial lakes. Multi-temporal glacial lake mapping is conducted using Landsat and Cartosat imagery. Avalanche and rockfall modeling are combined with morphometric analysis of the proglacial lake area to assess the likelihood of glacial lake dam failure. The above parameters are integrated into a decision tree approach enabling categorization of moraine-dammed lakes according to their potential for outburst events.

  17. Microplastic pollution in the surface waters of Italian Subalpine Lakes.

    PubMed

    Sighicelli, Maria; Pietrelli, Loris; Lecce, Francesca; Iannilli, Valentina; Falconieri, Mauro; Coscia, Lucia; Di Vito, Stefania; Nuglio, Simone; Zampetti, Giorgio

    2018-05-01

    Plastic debris incidence in marine environment was already highlighted in the early 1970s. Over the last decade, microplastic pollution in the environment has received increasing attention and is now an emerging research area. Many studies have focused on quantifying microplastic abundance in the marine environment, while there are relatively few data on microplastic occurrence in freshwater environment. Recent studies have reported high concentrations of microplastics in lakes and rivers, although the understanding of several factors influencing source, transport and fate is still limited. This study compares different lakes and the common factors, which could influence the occurrence and distribution of microplastics. The three subalpine lakes monitored include Lake Maggiore, Iseo and Garda. The selected sampling transects reflect the hydrologic conditions, the morphometric characteristics of these lakes, and other factors influencing the release of plastics debris in lakes. Particles of microplastics (<5 mm) were found in all sampled surfaces. The particles collected were classified depending on their number, shape and composition. The shape distribution showed the dominating occurrence of fragments (73.7%). The chemical composition of all examined samples clearly shows dominating presence of polyethylene (45%), polystyrene (18%) and polypropylene (15%). The results provide significant relations among the different contribution of direct and diffuse sources to the quantity of microplastics, highlighting the importance of understanding the spatial distribution dynamics of microplastics within a lake system that acts as a sink and source of plastic particles. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Collection, processing, and interpretation of ground-penetrating radar data to determine sediment thickness at selected locations in Deep Creek Lake, Garrett County, Maryland, 2007

    USGS Publications Warehouse

    Banks, William S.L.; Johnson, Carole D.

    2011-01-01

    This investigation focused on selected regions of the study area, particularly in the coves where sediment accumulations were presumed to be thickest. GPR was the most useful tool for interpreting sediment thickness, especially in these shallow coves. The radar profiles were interpreted for two surfaces of interest-the water bottom, which was defined as the "2007 horizon," and the interface between Lake sediments and the original Lake bottom, which was defined as the "1925 horizon"-corresponding to the year the Lake was impounded. The ground-penetrating radar data were interpreted on the basis of characteristics of the reflectors. The sediments that had accumulated in the impounded Lake were characterized by laminated, parallel reflections, whereas the subsurface below the original Lake bottom was characterized by more discontinuous and chaotic reflections, often with diffractions indicating cobbles or boulders. The reflectors were picked manually along the water bottom and along the interface between the Lake sediments and the pre-Lake sediments. A simple graphic approach was used to convert traveltimes to depth through water and depth through saturated sediments using velocities of the soundwaves through the water and the saturated sediments. Nineteen cross sections were processed and interpreted in 9 coves around Deep Creek Lake, and the difference between the 2007 horizon and the 1925 horizon was examined. In most areas, GPR data indicate a layer of sediment between 1 and 7 feet thick. When multiple cross sections from a single cove were compared, the cross sections indicated that sediment thickness decreased toward the center of the Lake.

  19. Geology and hydrology between Lake McMillan and Carlsbad Springs, Eddy County, New Mexico

    USGS Publications Warehouse

    Cox, Edward Riley

    1967-01-01

    The hydrology of the Pecos River valley between Lake McMillan and Carlsbad Springs, Eddy County, N. Mex., is influenced by facies changes in rocks of Permian age. Water stored for irrigation leaks from Lake McMillan into evaporite rocks, principally gypsum, of the Seven Rivers Formation and from Lake Avalon into carbonate rocks of the Tansill Formation. This leakage returns to the Pecos River at Major Johnson Springs and Carlsbad Springs. The river has perennial flow between Major Johnson Springs and Lake Avalon, but it loses water into evaporite rocks of the Yates Formation in this reach. Ground-water movement is generally toward the Pecos River in aquifers in the Pecos River valley except in the Rustler Formation east of the river where it moves southeastward toward playas east of Lake Avalon. The chloride content of ground and surface waters indicates that surface water moves from some reaches of the Pecos River and from surface-storage reservoirs to aquifers and also indicates the degree of mixing of ground and surface waters. About 45,000 acre-feet of ground water is stored in highly permeable rocks in a 3-mile wide part of the Seven Rivers Formation between Lake McMillan and Major Johnson Springs. This water in storage comes from leakage from Lake McMillan and from alluvium north of the springs. The flow of Major Johnson Springs is derived from this aquifer. That part of the flow derived from the alluvium north of the springs averaged 13 cfs (cubic feet per second) from 1953 through 1959 ; about 8 cfs of this flow had not been previously measured at gaging stations on the Pecos River and its tributaries. The most favorable plans for increasing terminal storage of the Carlsbad Irrigation District are to construct a dam at the Brantley site (at the downstream end of Major Johnson Springs), or to use underground storage in the permeable Seven Rivers Formation between Lake McMillan and Major Johnson brings in conjunction with surface storage. To avoid excessive leakage from a reservoir at the Brantley site, the dam should be downstream from all sprints in the Major Johnson Springs area but upstream from a point where the river begin losing water to the Yates Formation.

  20. Exploring the water storage changes in the largest lake (Selin Co) over the Tibetan Plateau during 2003-2012 from a basin-wide hydrological modeling

    NASA Astrophysics Data System (ADS)

    Zhou, Jing; Wang, Lei; Zhang, Yinsheng; Guo, Yanhong

    2016-04-01

    Lake water storage change (DSw) is an important indicator of the hydrologic cycle and greatly influences lake expansion/shrinkage over the Tibetan Plateau (TP). Accurate estimation of DSw will contribute to improved understanding of lake variations in the TP. Based on a water balance, this study explored the variations of DSw for the Lake Selin Co (the largest closed lake on the TP) during 2003-2012 using the Water and Energy Budget-based Distributed Hydrological Model (WEB-DHM) together with two different evapotranspiration (ET) algorithms (the Penman-Monteith method and a simple sublimation estimation approach for water area in unfrozen and frozen period). The contributions of basin discharge and climate causes to the DSw are also quantitatively analyzed. The results showed that WEB-DHM could well reproduce daily discharge, the spatial pattern, and basin-averaged values of MODIS land surface temperature (LST) during nighttime and daytime. Compared with the ET reference values estimated from the basin-wide water balance, our ET estimates showed better performance than three global ET products in reproducing basin-averaged ET. The modeled ET at point scale matches well with short-term in situ daily measurements (RMSE=0.82 mm/d). Lake inflows and precipitation over the water area had stronger relationships with DSw in the warm season and monthly scale, whereas evaporation from the water area had remarkable effects on DSw in the cold season. The total contribution of the three factors to DSw was about 90%, and accounting for 49.5%, 22.1%, and 18.3%, respectively.

  1. Floodplain lakes and alluviation cycles of the lower Colorado River

    NASA Astrophysics Data System (ADS)

    Malmon, D.; Felger, T. J.; Howard, K. A.

    2007-05-01

    The broad valleys along the lower Colorado River contain numerous bodies of still water that provide critical habitat for bird, fish, and other species. This chain of floodplain lakes is an important part of the Pacific Flyway - the major north-south route of travel for migratory birds in the western Hemisphere - and is also used by many resident bird species. In addition, isolated floodplain lakes may provide the only viable habitat for endangered native fish such as the razorback sucker, vulnerable to predation by introduced species in the main stem of the Colorado River. Floodplain lakes typically occupy former channel courses of the river and formed as a result of river meandering or avulsion. Persistent fluvial sediment deposition (aggradation) creates conditions that favor rapid formation and destruction of floodplain lakes, while long term river downcutting (degradation) inhibits their formation and evolution. New radiocarbon dates from wood recovered from drill cores near Topock, AZ indicate that the river aggraded an average of 3 mm/yr in the middle and late Holocene. Aggradational conditions before Hoover Dam was built were associated with rapid channel shifting and frequent lake formation. Lakes had short life spans due to rapid infilling with fine-grained sediment during turbid floods on the unregulated Colorado River. The building of dams and of armored banks had a major impact on floodplain lakes, not only by drowning large portions of the valley beneath reservoirs, but by preventing new lake formation in some areas and accelerating it in others. GIS analyses of three sets of historical maps show that both the number and total area of isolated (i.e., not linked to the main channel by a surface water connection) lakes in the lower Colorado River valley increased between 1902 and the 1950s, and then decreased though the 1970s. River bed degradation below dams inhibits channel shifting and floodplain lake formation, and the capture of fines behind the dams has prevented sediment infilling of the lakes. Bed lowering below dams and in artificially confined reaches could potentially dewater floodplain lakes, a process occurring at Beal Lake, a natural lake used for native fish restoration in the Havasu National Wildlife Refuge. Sedimentation near the upstream ends of reservoirs has created large areas of still water. One of the largest, Topock Marsh, is connected to the main channel, restricting its usefulness as a native fish nursery; other backwater areas are confined by bars that isolate standing water at tributaries.

  2. Linkage between Three Gorges Dam impacts and the dramatic recessions in China’s largest freshwater lake, Poyang Lake

    PubMed Central

    Mei, Xuefei; Dai, Zhijun; Du, Jinzhou; Chen, Jiyu

    2015-01-01

    Despite comprising a small portion of the earth’s surface, lakes are vitally important for global ecosystem cycling. However, lake systems worldwide are extremely fragile, and many are shrinking due to changing climate and anthropogenic activities. Here, we show that Poyang Lake, the largest freshwater lake in China, has experienced a dramatic and prolonged recession, which began in late September of 2003. We further demonstrate that abnormally low levels appear during October, 28 days ahead of the normal initiation of the dry season, which greatly imperiled the lake’s wetland areas and function as an ecosystem for wintering waterbirds. An increase in the river-lake water level gradient induced by the Three Gorges Dam (TGD) altered the lake balance by inducing greater discharge into the Changjiang River, which is probably responsible for the current lake shrinkage. Occasional episodes of arid climate, as well as local sand mining, will aggravate the lake recession crisis. Although impacts of TGD on the Poyang Lake recession can be overruled by episodic extreme droughts, we argue that the average contributions of precipitation variation, human activities in the Poyang Lake catchment and TGD regulation to the Poyang Lake recession can be quantified as 39.1%, 4.6% and 56.3%, respectively. PMID:26657816

  3. Linkage between Three Gorges Dam impacts and the dramatic recessions in China’s largest freshwater lake, Poyang Lake

    NASA Astrophysics Data System (ADS)

    Mei, Xuefei; Dai, Zhijun; Du, Jinzhou; Chen, Jiyu

    2015-12-01

    Despite comprising a small portion of the earth’s surface, lakes are vitally important for global ecosystem cycling. However, lake systems worldwide are extremely fragile, and many are shrinking due to changing climate and anthropogenic activities. Here, we show that Poyang Lake, the largest freshwater lake in China, has experienced a dramatic and prolonged recession, which began in late September of 2003. We further demonstrate that abnormally low levels appear during October, 28 days ahead of the normal initiation of the dry season, which greatly imperiled the lake’s wetland areas and function as an ecosystem for wintering waterbirds. An increase in the river-lake water level gradient induced by the Three Gorges Dam (TGD) altered the lake balance by inducing greater discharge into the Changjiang River, which is probably responsible for the current lake shrinkage. Occasional episodes of arid climate, as well as local sand mining, will aggravate the lake recession crisis. Although impacts of TGD on the Poyang Lake recession can be overruled by episodic extreme droughts, we argue that the average contributions of precipitation variation, human activities in the Poyang Lake catchment and TGD regulation to the Poyang Lake recession can be quantified as 39.1%, 4.6% and 56.3%, respectively.

  4. Characteristics of environmental correlations between iron (oxyhydr)oxide nanoparticles and microbial activity

    NASA Astrophysics Data System (ADS)

    Tamura, T.; Kyono, A.; Muratani, M.

    2014-12-01

    Nanoparticulate iron oxides and oxyhydroxides with large surface area and high chemical reactivity cause the immobilization of heavy metals and the provision of essential nutrients to organisms. Environmental correlations between microbial activity and nanomorphology of iron (oxyhydr)oxides are significantly important for earth surface processes. In this study, we characterize iron (oxyhydr)oxide nanoparticles and microorganisms in natural lake sediments and describe their association observed between particle nanostructures and microbial species. About 40 cm depth of boring core sample was collected from Lake Kasumigaura, Lake Ushiku, Kokai River and Lake Tega, Japan. To distinguish both iron nanoparticles and growing bacterial colonies with depths, boring core samples were divided into three to five pieces. Particle morphologies, size, aggregation states, mineral species, and microorganisms were observed by transmission electron microscopy (TEM), X-ray diffraction (XRD), and rRNA gene sequences. Redox potential and pH of the lake sediments were also measured. The core sample from top is mainly composed of quartz of coarse-grained materials, while that from bottom is of ferrihydrite of fine grained materials. The authors will show the results of experiments and discuss the interrelation between iron nanoparticles and microorganisms.

  5. Clay deposits of the Connecticut River Valley, Connecticut: a special problem in land management

    USGS Publications Warehouse

    Langer, William H.

    1972-01-01

    When man first settled the United States, two natural features favored settlement; flat land that was easy to build on and to farm, and a nearby river that could act as a source of water, transportation, and power. The Connecticut River Valley from Middletown, Ct. north past the Connecticut-Massachusetts state line satisfied these two needs, and was favored by many early Americans in New England. This area remains an area of rapid urbanization, partly because of the broad flat lowlands. The subdued topography of this area is due in large part to deposition of fine-grained materials into glacial Lake Hitchcock. This lake was formed during the Wisconsinan age when southward drainage in the Triassic valley of Connecticut was dammed by glacial drift in the area of Rocky Hill, Connecticut. Lake Hitchcock grew to and beyond St. Johnsbury, Vt. with much of the lake being filled with cyclical lake-bottom deposits during the 2,290 to 2,350 years of its life. Aside from the relative flatness inherent in the deposition of fine-grained lake-bottom deposits, these deposits present very few characteristics that are favorable for urbanization. Favorable characteristics are possible sources of clay for manufacturing and possible sources for waste storage sites. Unfavorable characteristics include low water yields resulting in poor urban water-supply sources, and very low flows in streams during dry periods; low percolation rates resulting In drainage and septic problems; and low or uneven bearing strength which create problems in construction. Fine-grained lake-bottom deposits have been mapped for six quadrangles in the Connecticut Valley lowlands; the quadrangles of Windsor Locks, Broad Brook, Hartford North, Manchester, Hartford South, and Glastonbury (all located in Connecticut). All the maps were prepared from existing information including well and test hole data on file at the Water Resources Division in Hartford, surficial geologic quadrangle maps, and bedrock contour maps. The maps also reflect geologic interpretations of the history of glacial Lake Hitchcock. The Hartford North maps were prepared as test maps to determine if the project was feasible. They were prepared using the previously described information plus additional subsurface data obtained from engineering firms and the State Highway Department. During preparation of the maps, an arcuate-shaped, ice-contact deposit composed of coarse sand and gravel was delineated in the Broad Brook and Windsor Locks quadrangles. This feature marks the location of a zone of stagnant ice In front of and marginal to active ice to the north. Two types of maps were prepared for the area in study; Thickness of the Principal Clay Deposit, and Thickness of Material Overlying the Principal Clay Deposit. The term "principal clay deposit" refers to the fine-grained lake-bottom deposits of Glacial Lake Hitchcock. These maps define the distribution of the deposit, and show the thickness of the deposit in 50 foot intervals and the thickness of the material overlying the deposit In 20 foot intervals. The maps indicate that much of the area is underlain with substantial thicknesses of finegrained lake-bottom deposits (50 feet thick or greater), and that much of the deposit is within 20 feet of the surface. The maps included in this report can be used for land-use planning. Uses include location of favorable sites for specific uses such as landfills, utility corridors, heavy construction, etc; location of problem areas for specific land uses; identification of possible problems for specific areas; design and construction cost estimates; and prospecting for exploitable clay deposits. It Is suggested that, for effective planning, these maps be used together or in conjunction with other maps such as maps showing surface materials, depth to bedrock, depth to water table, and flood prone areas.

  6. Examining the utility of satellite-based wind sheltering estimates for lake hydrodynamic modeling

    USGS Publications Warehouse

    Van Den Hoek, Jamon; Read, Jordan S.; Winslow, Luke A.; Montesano, Paul; Markfort, Corey D.

    2015-01-01

    Satellite-based measurements of vegetation canopy structure have been in common use for the last decade but have never been used to estimate canopy's impact on wind sheltering of individual lakes. Wind sheltering is caused by slower winds in the wake of topography and shoreline obstacles (e.g. forest canopy) and influences heat loss and the flux of wind-driven mixing energy into lakes, which control lake temperatures and indirectly structure lake ecosystem processes, including carbon cycling and thermal habitat partitioning. Lakeshore wind sheltering has often been parameterized by lake surface area but such empirical relationships are only based on forested lakeshores and overlook the contributions of local land cover and terrain to wind sheltering. This study is the first to examine the utility of satellite imagery-derived broad-scale estimates of wind sheltering across a diversity of land covers. Using 30 m spatial resolution ASTER GDEM2 elevation data, the mean sheltering height, hs, being the combination of local topographic rise and canopy height above the lake surface, is calculated within 100 m-wide buffers surrounding 76,000 lakes in the U.S. state of Wisconsin. Uncertainty of GDEM2-derived hs was compared to SRTM-, high-resolution G-LiHT lidar-, and ICESat-derived estimates of hs, respective influences of land cover type and buffer width on hsare examined; and the effect of including satellite-based hs on the accuracy of a statewide lake hydrodynamic model was discussed. Though GDEM2 hs uncertainty was comparable to or better than other satellite-based measures of hs, its higher spatial resolution and broader spatial coverage allowed more lakes to be included in modeling efforts. GDEM2 was shown to offer superior utility for estimating hs compared to other satellite-derived data, but was limited by its consistent underestimation of hs, inability to detect within-buffer hs variability, and differing accuracy across land cover types. Nonetheless, considering a GDEM2 hs-derived wind sheltering potential improved the modeled lake temperature root mean square error for non-forested lakes by 0.72 °C compared to a commonly used wind sheltering model based on lake area alone. While results from this study show promise, the limitations of near-global GDEM2 data in timeliness, temporal and spatial resolution, and vertical accuracy were apparent. As hydrodynamic modeling and high-resolution topographic mapping efforts both expand, future remote sensing-derived vegetation structure data must be improved to meet wind sheltering accuracy requirements to expand our understanding of lake processes.

  7. Estimation of capture zones and drawdown at the Northwest and West Well Fields, Miami-Dade County, Florida, using an unconstrained Monte Carlo analysis: recent (2004) and proposed conditions

    USGS Publications Warehouse

    Brakefield, Linzy K.; Hughes, Joseph D.; Langevin, Christian D.; Chartier, Kevin

    2013-01-01

    Travel-time capture zones and drawdown for two production well fields, used for drinking-water supply in Miami-Dade County, southeastern Florida, were delineated by the U.S Geological Survey using an unconstrained Monte Carlo analysis. The well fields, designed to supply a combined total of approximately 250 million gallons of water per day, pump from the highly transmissive Biscayne aquifer in the urban corridor between the Everglades and Biscayne Bay. A transient groundwater flow model was developed and calibrated to field data to ensure an acceptable match between simulated and observed values for aquifer heads and net exchange of water between the aquifer and canals. Steady-state conditions were imposed on the transient model and a post-processing backward particle-tracking approach was implemented. Multiple stochastic realizations of horizontal hydraulic conductivity, conductance of canals, and effective porosity were simulated for steady-state conditions representative of dry, average and wet hydrologic conditions to calculate travel-time capture zones of potential source areas of the well fields. Quarry lakes, formed as a product of rock-mining activities, whose effects have previously not been considered in estimation of capture zones, were represented using high hydraulic-conductivity, high-porosity cells, with the bulk hydraulic conductivity of each cell calculated based on estimates of aquifer hydraulic conductivity, lake depths and aquifer thicknesses. A post-processing adjustment, based on calculated residence times using lake outflows and known lake volumes, was utilized to adjust particle endpoints to account for an estimate of residence-time-based mixing of lakes. Drawdown contours of 0.1 and 0.25 foot were delineated for the dry, average, and wet hydrologic conditions as well. In addition, 95-percent confidence intervals (CIs) were calculated for the capture zones and drawdown contours to delineate a zone of uncertainty about the median estimates. Results of the Monte Carlo simulations indicate particle travel distances at the Northwest Well Field (NWWF) and West Well Field (WWF) are greatest to the west, towards the Everglades. The man-made quarry lakes substantially affect particle travel distances. In general near the NWWF, the capture zones in areas with lakes were smaller in areal extent than capture zones in areas without lakes. It is possible that contamination could reach the well fields quickly, within 10 days in some cases, if it were introduced into lakes nearest to supply wells, with one of the lakes being only approximately 650 feet from the nearest supply well. In addition to estimating drawdown and travel-time capture zones of 10, 30, 100, and 210 days for the NWWF and the WWF under more recent conditions, two proposed scenarios were evaluated with Monte Carlo simulations: the potential hydrologic effects of proposed Everglades groundwater seepage mitigation and quarry-lake expansion. The seepage mitigation scenario included the addition of two proposed anthropogenic features to the model: (1) an impermeable horizontal flow barrier east of the L-31N canal along the western model boundary between the Everglades and the urban areas of Miami-Dade County, and (2) a recharge canal along the Dade-Broward Levee near the NWWF. Capture zones and drawdown for the WWF were substantially affected by the addition of the barrier, which eliminates flow from the western boundary into the active model domain, shifting the predominant capture zone source area from the west more to the north and south. The 95-percent CI for the 210-day capture zone moved slightly in the NWWF as a result of the recharge canal. The lake-expansion scenario incorporated a proposed increase in the number and surface area of lakes by an additional 25 square miles. This scenario represents a 150-percent increase from the 2004 lake surface area near both well fields, but with the majority of increase proposed near the NWWF. The lake-expansion scenario substantially decreased the extent of the 210-day capture zone of the NWWF, which is limited to the lakes nearest the well field under proposed conditions.

  8. Use of MODIS Terra Imagery to Estimate Surface Water Quality Standards, Using Lake Thonotosassa, Florida, as a Case Study

    NASA Technical Reports Server (NTRS)

    Moreno, Max J.; Al-Hamdan, Mohammad Z.; Estes, Maurice G., Jr.; Rickman, Douglas L.

    2010-01-01

    Lake Thonotosassa is a highly eutrophied lake located in an area with rapidly growing population in the Tampa Bay watershed, Florida. The Florida Administrative Code has designated its use for "recreation, propagation and maintenance of a healthy, well-balanced population of fish and wildlife." Although this lake has been the subject of efforts to improve water quality since 1970, overall water quality has remained below the acceptable state standards, and has a high concentration of nutrients. This condition is of great concern to public health since it has favored episodic blooms of Cyanobacteria. Some Cyanobacterial species release toxins that can reach humans through drinking water, fish consumption, and direct contact with contaminated water. The lake has been historically popular for fishing and water sports, and its overflow water drains into the Hillsborough River, the main supply of municipal water for the City of Tampa, this explains why it has being constantly monitored in situ for water quality by the Environmental Protection Commission of Hillsborough County (EPC). Advances in remote sensing technology, however, open the possibility of facilitating similar types of monitoring in this and similar lakes, further contributing to the implementation of surveillance systems that would benefit not just public health, but also tourism and ecosystems. Although traditional application of this technology to water quality has been focused on much larger coastal water bodies like bays and estuaries, this study evaluates the feasibility of its application on a 46.6 km2 freshwater lake. Using surface reflectance products from Moderate-Resolution Imaging Spectroradiometer (MODIS) Terra, this study evaluates associations between remotely sensed data and in situ data from the EPC. The parameters analyzed are the surface water quality standards used by the State of Florida and general indicators of trophic status.

  9. Inorganic mercury (Hg2+) accumulation in autotrophic and mixotrophic planktonic protists: Implications for Hg trophodynamics in ultraoligotrophic Andean Patagonian lakes.

    PubMed

    Soto Cárdenas, Carolina; Gerea, Marina; Queimaliños, Claudia; Ribeiro Guevara, Sergio; Diéguez, María C

    2018-05-01

    Microbial assemblages are typical of deep ultraoligotrophic Andean Patagonian lakes and comprise picoplankton and protists (phytoflagellates and mixotrophic ciliates), having a central role in the C cycle, primary production and in the incorporation of dissolved inorganic mercury (Hg 2+ ) into lake food webs. In this study we evaluated the mechanisms of Hg 2+ incorporation in hetero- and autotrophic bacteria, in the autotrophic dinoflagellate (Gymnodinium paradoxum) and in two mixotrophic ciliates (Stentor araucanus and Ophrydium naumanni) dominating the planktonic microbial assemblage. The radioisotope 197 Hg was used to trace the Hg 2+ incorporation in microbiota. Hg uptake was analyzed as a function of cell abundance (BCF: bioconcentration factor), cell surface (SCF: surface concentration factor) and cell volume (VCF: volume concentration factor). Overall, the results obtained showed that these organisms incorporate substantial amounts of dissolved Hg 2+ passively (adsorption) and actively (bacteria consumption or attachment), displaying different Hg internalization and therefore, varying potential for Hg transfer. Surface area and quality, and surface:volume ratio (S:V) control the passive uptake in all the organisms. Active incorporation depends on bacteria consumption in the mixotrophic ciliates, or on bacteria association to surface in the autotrophic dinoflagellate. Hg bioaccumulated by pelagic protists can be transferred to higher trophic levels through plankton and fish feeding, regenerated to the dissolved phase by excretion, and/or transferred to the sediments by particle sinking. In ultraoligotrophic Andean Patagonian lakes, picoplankton and planktonic protists are key components of lake food webs, linking the pelagic and benthic Hg pathways, and thereby playing a central role in Hg trophodynamics. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Earth observations taken by the Expedition 14 crew

    NASA Image and Video Library

    2006-11-18

    ISS014-E-08179 (18 Nov. 2006) --- New Orleans, Louisiana is featured in this image photographed by an Expedition 14 crewmember on the International Space Station. The location of New Orleans, in a shallow depression within unconsolidated deltaic sediments, makes it particularly vulnerable to subsidence and increased likelihood of flooding. The average elevation of metropolitan New Orleans is 1.8 meters below sea level, and a complicated system of levees, pumps, and upstream control structures on the Mississippi River is necessary to maintain dry conditions in the city. The ground subsidence occurs from groundwater withdrawal, reduction of sediment delivery by the Mississippi River, and land use changes (such as draining of wetlands) associated with continuing development. The low areas can be flooded by river floods, storm surges, or failure of levees holding back surrounding lake waters - as demonstrated catastrophically during Hurricane Katrina in 2005. Sunglint accentuates the wetland setting of New Orleans in this image by highlighting the numerous lakes, pond, and rivers (in various shades of silver-gray) surrounding the city. The view was acquired by a crewmember looking southwest from the station, which was located over north-central Alabama at the time this image was taken. Lake Pontchartrain borders New Orleans to the north, and the Lake Pontchartrain Causeway (36 kilometers in length) appears as a dark linear feature against the lake surface. Variations in surface water coloration to the east and west of the Causeway reflect the dynamics of the surface waters (including surface currents and wind-induced roughening). The patterns are made visible by the presence of surfactants on the water surface. Low cloud cover produces a blue-gray haze visible at lower left.

  11. Environmental engineering interventions to control the expansion of salty lakes and marshes in siwa oasis.

    PubMed

    El-Naggar, Hesham M

    2010-01-01

    The main activity in Siwa Oasis society is the agriculture, it depends on the groundwater. The agricultural drainage water and the unused saline water of naturally flowing springs are poured into four main salty lakes. This leads to an increase in the surface area of the saltwater lakes, marshes and rise in water table levels. to investigate some environmental engineering interventions to control the expansion of saltwater surface area in Siwa Oasis. Field visits, observation sheets and questionnaire survey with farmers were carried out to find out the main environmental problems in the Oasis. Environmental survey was carried out to collect different rocks and stones samples as natural construction materials from the desert that surrounds Siwa Oasis. Physical analyses, chemical composition and principal mechanical parameters were conducted on the collected samples. After the analysis, the safa rocks were the best natural construction materials in the Siwa Oasis. So, it could be used to build a construction wall around the salty lakes and marshes. Walls could convert the lakes into basins. The water will be evaporated at high rate during summer season by solar energy. After evaporation, the remaining salty rock named "karshef" can be easily collected from the lakes to be used as a low cost construction material for traditional building houses in Siwa Oasis. Therefore, the water level of lakes will be reduced to dryness and land could be reused as agricultural land. Among different rocks, safa rocks proved to be the best natural construction materials to construct a defense wall around the lakes and marshes. They will save about 80% of the concrete cost. The formed karshef rocks from the lakes will be used in the construction of the traditional building houses which will save about 90% of the concrete buildings. This intervention will save energy as it exchanges fuel consuming man-made material such as cement with naturally made material. This can reduce the green house gases generated from the cement industry. Economical feasibility study should be carried out to estimate the capital cost for the retaining wall.

  12. Detecting glacier-bed overdeepenings for glaciers in the Western Italian Alps using the GlabTop2 model: the test site of the Rutor Glacier, Aosta Valley

    NASA Astrophysics Data System (ADS)

    Viani, Cristina; Machguth, Horst; Huggel, Christian; Perotti, Luigi; Giardino, Marco

    2016-04-01

    It is expected that the rapid retreat of glaciers, observed in the European Alps and other mountain regions of the world, will continue in the future. One of the most evident and relevant consequences of this phenomenon is the formation of new glacier lakes in recently deglaciated areas. During glacier retreat overdeepened parts of the glacier bed become exposed and, in some cases, filled with water. It is important to understand where these new lakes can appear because of the associated potential risks (i.e. lake outburst and consequent flood) and opportunities (tourism, hydroelectricity, water reservoir, etc.) especially in densely populated areas such as the European Alps. GlabTop2 (Glacier Bed Topography model version 2) allows to model glacier bed topography over large glaciated areas combining digital terrain information and slope-related estimates of glacier thickness. The model requires a minimum set of input data: glaciers outlines and a surface digital elevation model (DEM). In this work we tested the model on the Rutor Glacier (8,1 km2) located in the Aosta Valley. The glacier has a well-known history of a series of glacier lake outburst floods between 1430 AD and 1864 AD due to front fluctuations. After the last advance occurred during the 70s of the previous century, glacier shrinkage has been continuous and new lakes have formed in newly exposed overdeepenings. We applied GlabTop2 to DEMs derived from historical data (topographic maps and aerial photos pair) representing conditions before the proglacial lake formation. The results obtained have been compared with the present situation and existing lakes. Successively we used the model also on present-day DEMs, which are of higher resolution than the historical derived ones, and compared the modeled bed topography with an existing bedrock map obtained by in-situ geophysical investigations (GPR surveys). Preliminary results, obtained with the 1991 surface model, confirm the robustness of GlabTop2 in detecting the overdeepenings (6 were identified) and their location. Regarding their size, it seems to be influenced by the resolution of input data: the total overdeepended area covers about 1,3 km2 in the case of 25m pixel size and about 0,6 km2 in the 75m one. Based on the results obtained with model application and verification at Rutor Glacier, GlapTop2 will be applied over larger areas of the Western Italian Alps (Piemonte and Aosta Valley) in order to assess locations of possible future lakes to facilitate identification of potentially hazardous conditions and dynamics.

  13. SWOT Hydrology in the classroom

    NASA Astrophysics Data System (ADS)

    Srinivasan, M. M.; Destaerke, D.; Butler, D. M.; Pavelsky, T.

    2014-12-01

    The Surface Water and Ocean Topography (SWOT) Mission Education Program will participate in the multinational, multiagency program, Global Learning and Observations to Benefit the Environment (GLOBE). GLOBE is a worldwide hands-on, primary and secondary school-based science and education community of over 24,000 schools in more than 100 countries. Over 1.5 million students have contributed more than 23 million measurements to the GLOBE database for use in inquiry-based science projects. The objectives of the program are to promote the teaching and learning of science; enhance environmental awareness, literacy and stewardship; and contribute to science research and environmental monitoring.SWOT will measure sea surface height and the heights, slopes, and inundated areas of rivers, lakes, and wetlands. This new SWOT-GLOBE partnership will focus on the limnology aspects of SWOT. These measurements will be useful in monitoring the hydrologic cycle, flooding, and climate impacts of a changing environment.GLOBE's cadre of teachers are trained in five core areas of Earth system science, including hydrology. The SWOT Education teams at NASA and CNES are working with the GLOBE Program implementers to develop and promote a new protocol under the Hydrology topic area for students to measure attributes of surface water bodies that will support mission science objectives. This protocol will outline and describe a methodology to measure width and height of rivers and lakes.This new GLOBE protocol will be included in training to provide teachers with expertise and confidence in engaging students in this new scientific investigation. Performing this additional measurement will enhance GLOBE students experience in scientific investigation, and will provide useful measurements to SWOT researchers that can support the SWOT mission research goals.SWOT public engagement will involve communicating the value of its river and lake height measurements, lake water storage, and river discharge. This is also important to the GLOBE Program as curriculum integration of its hydrology measurements can be enhanced by strengthened ties to the concepts of watersheds and the hydrologic cycle. Understanding can also be increased of the relation of lake and river levels to drought and water supply.

  14. Spatial Evaluation of Heavy Metals Concentrations in the Surface Sediment of Taihu Lake

    PubMed Central

    Niu, Yong; Jiao, Wei; Yu, Hui; Niu, Yuan; Pang, Yong; Xu, Xiangyang; Guo, Xiaochun

    2015-01-01

    With regard to the size of China’s freshwater lakes, Taihu Lake ranks third and it plays an important role in the supply of drinking water, flood prevention, farming and navigation, as well as in the travelling industry. The problem of environmental pollution has attracted widespread attention in recent years. In order to understand the levels, distribution and sources of heavy metals in sediments of Taihu Lake, random selection was carried out to obtain 59 samples of surface sediment from the entire lake and study the concentrations of Pb, Cd, Cu, Zn, Cr and Ni. Toxic units were also calculated to normalize the toxicities caused by various heavy metals. As a result, Cd and Cu in sediment were considered lower than the effect range low (ERL) at all regions where samples were gathered, while Pb and Ni were categorized into ERL-effect range median (ERM) at over 22% of the regions where samples were obtained. Nevertheless, all average concentrations of the samples were below the level of potential effect. According to the findings of this research, significant spatial heterogeneity existed in the above heavy metals. In conclusion, the distribution areas of heavy metals with higher concentrations were mainly the north bays, namely Zhushan Bay, Meiliang Bay as well as Gonghu Bay. The distribution areas of Cu, Zn, Cr and Ni with higher concentration also included the lake’s central region, whereas the uniform distribution areas of those with lower concentrations were the lake’s southeast region. In addition, it was most probable that the spatial distribution of heavy metals was determined by river inputs, whereas atmospheric precipitation caused by urban and traffic contamination also exerted considerable effects on the higher concentrations of Pb and Cd. Through evaluating the total amount of toxic units (ΣTU), it was found that higher toxicity existed primarily in the north bays and central region of the lake. If the heavy metals were sorted by the reduction of mean heavy metal toxic units in Taihu Lake in descending order, it would be Pb, Cr, Ni, Cd, Zn and Cu. Generally speaking, these result of analyses are conducive to alleviating the contamination of heavy metals in Taihu Lake. PMID:26633432

  15. Modeling of sediment transport in a saltwater lake with supplemental sandy freshwater.

    PubMed

    Liang, Li; Deng, Yun; Li, Ran; Li, Jia

    2018-06-22

    Considering the highly complex flow structure of saltwater lakes during freshwater supplementation, a three-dimensional numerical model was developed to simulate suspended sediment transport in saltwater lakes. The model was validated using measurements of the salinity and sediment concentration during a pumping test at Yamdrok Lake. The simulation results were in quantitative agreement with the measured data. The observed and simulated results also indicated that the wind stress and vertical salinity gradient have a significant influence on salinity and sediment transport in a saltwater lake. The validated model was then used to predict and analyze the contributions of wind, the supplement flow rate and salinity stratification to the sediment transport process in Yamdrok Lake during continuous river water supplementation. The simulation results showed that after the sandy river water was continuously discharged into the saltwater lake, the lateral diffusion trends of the sediment exhibited three stages: linear growth in the inflow direction, logarithmic growth in the wind direction, and stabilization. Furthermore, wind was the dominant factor in driving the lake flow pattern and sediment transport. Specifically, wind can effectively reduce the area of the sediment diffusion zone by increasing the lateral sediment carrying and dilution capacities. The effect of inflow on the lake current is negligible, but the extent of the sediment turbidity zone mainly depends on the inflow. Reducing the inflow discharge can decrease the area of the sediment turbidity zone to proportions that far exceed the proportions of inflow discharge reductions. In addition, the high-salinity lake water can support the supplemented freshwater via buoyancy forces, which weaken vertical mixing and sediment settlement and increase lake currents and sediment diffusion near the surface.

  16. Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes

    USGS Publications Warehouse

    Eagles-Smith, Collin A.; Herring, Garth; Johnson, Branden L.; Graw, Rick

    2016-01-01

    Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish.

  17. Assessing Resiliency in a Large Lake Receiving Mine Tailings Waste: Impacts of Major Environmental Disturbance.

    NASA Astrophysics Data System (ADS)

    Petticrew, Ellen; Owens, Philip; Albers, Sam

    2016-04-01

    On 4th August 2014, the tailings impoundment of the Mount Polley copper and gold mine in British Columbia failed. Material from the impoundment (surface area = 2.7 km2) flowed into nearby Polley Lake and Hazeltine Creek, before discharging into Quesnel Lake, a large (ca. 100 km long, >500 m deep), relatively pristine lake. Initial estimates suggest that approximately 25 Mm3 of tailings (water and solids) and eroded soils and surficial materials from Hazeltine Creek were delivered to Quesnel Lake, raising the lake by 7.7 cm. Much of this material was deposited at the bottom of Quesnel Lake but a plume of fine-grained sediment (D50 of ca. 1 μm) remained suspended in the water column. The impact of the distribution of this sediment was monitored over the next 15 months using water column profiling for temperature, conductivity, fluorescence and turbidity with depth. The plume movement was regulated by natural processes associated with the physical limnology of this large fjord lake, specifically, seiche events which transferred suspended particles both up-lake, against the flow regime, and down-lake into the Quesnel River. Samples of lake water and bottom sediment taken from the impacted area show elevated levels of total metals and other elements, which may have important ecosystem implications in this watershed. Indeed, the breach occurred at a time when a peak run of sockeye salmon were returning to their natal streams in the Quesnel basin. Zooplankton sampling for metals was initiated in fall 2014 to determine up take of metals into the food web. This poster describes the failure of the impoundment dam and presents results of sampling the aquatic environment over the first fifteen months of impact.

  18. Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes.

    PubMed

    Eagles-Smith, Collin A; Herring, Garth; Johnson, Branden; Graw, Rick

    2016-05-01

    Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish. Published by Elsevier Ltd.

  19. The Lake Urmia environmental disaster in Iran: A look at aerosol pollution.

    PubMed

    Hossein Mardi, Ali; Khaghani, Ali; MacDonald, Alexander B; Nguyen, Phu; Karimi, Neamat; Heidary, Parisa; Karimi, Nima; Saemian, Peyman; Sehatkashani, Saviz; Tajrishy, Massoud; Sorooshian, Armin

    2018-08-15

    Lake Urmia (LU) once was the second largest hypersaline lake in the world, covering up to 6000km 2 , but has undergone catastrophic desiccation in recent years resulting in loss of 90% of its area and extensive coverage by playas and marshlands that represent a source of salt and dust. This study examines daily Aerosol Optical Depth (AOD) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) between 2001 and 2015 over northwestern Iran, which encompasses LU. Intriguingly, salt emissions from the LU surface associated with ongoing desiccation do not drive the study region's AOD profile, whereas pollution transported from other regions and emissions around LU are more important. Signatures of increasing local crustal emissions are most evident outside of the peak dust season (January, February, and October) and on the periphery of LU. AOD has generally increased in the latter half of the study period with the onset of the AOD ramp-up starting a month earlier in the spring season when comparing 2009-2015 versus earlier years. Results indicate that suppression of emissions on the LU border is critical as the combined area of salt and salty soil bodies around LU have increased by two orders of magnitude in the past two decades, and disturbing these areas via activities such as grazing and salt harvesting on the lake surface can have more detrimental impacts on regional pollution as compared to benefits. These results have important implications for public health, climate, the hydrological cycle, and pollution control efforts. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Postimpoundment survey of water-quality characteristics of Raystown Lake, Huntingdon and Bedford Counties, Pennsylvania

    USGS Publications Warehouse

    Williams, Donald R.

    1978-01-01

    Water-quality data, collected from May 1974 to September 1976 at thirteen sites within Raystown Lake and in the inflow and outflow channels, define the water-quality characteristics of the lake water and the effects of impoundment on the quality of the lake outflow. Depth-profile measurements show Raystown Lake to be dimictic. Thermal stratification is well developed during the summer. Generally high concentrations of dissolved oxygen throughout the hypolimnion during thermal stratification, low phytoplankton concentrations, and small diel fluctuations of dissolved oxygen, pH, and specific conductance indicate that the lake is low in nutrients, or oligotrophic. Algal assays of surface samples indicate that orthophosphate was a growth-limiting nutrient. The diatoms (Chrysophyta) were the dominant phytoplankton group found through-out the study period. The lake waters contained very low populations of zooplankton. Fecal coliform and fecal streptococcus densities measured throughout the lake indicated no potentially dangerous areas of water-contact recreation. The most apparent effect that the impoundment had on water quality was the removal of nutrients, particularly orthophosphate, through phytoplankton uptake and sediment deposition.

  1. A Multi-Sensor Approach to Documenting a Large Collapse Sinkhole in West-Central Florida

    NASA Astrophysics Data System (ADS)

    Collins, L. D.; Kiflu, H. G.; Robinson, T.; Doering, T.; Eilers, D.; Rodgers, M.; Kruse, S.; Landry, S.; Braunmiller, J.; Speed, G.; Gonzalez, J.; McKenzie, R.

    2017-12-01

    The Saxon Lake sinkhole collapse of July 14, 2017 in Land O Lakes, Florida, caused the destruction of two homes and the evacuation of nine additional residences. The sinkhole is slightly oval with dimensions of approximately 51 meters east-west and 42 meters north-south, and it is reportedly 15 meters deep. This is presumably the largest sinkhole to form in Pasco County during the last 30 years. The surface collapse happened rapidly and continued over three days, with slumping and erosion increasing the size. The site is located near two natural lakes in a housing development from the late 1960s. This occurrence is within an area of well-developed karst, with a number of natural lakes. We present preliminary analysis of the sequence of deformation, sinkhole geometry, surrounding subsurface structures, and seismic activity. Data are assembled from terrestrial and aerial LiDAR, UAS survey and PhoDAR modeling, aerial imagery, ground penetrating radar, lake-bottom profiling, and seismic monitoring. Additionally, multi-sensor data were brought together in a Geographic Information Systems (GIS) and included an analysis of georeferenced historic imagery and maps. These spatial data indicate historic land use change and development alterations that included lake shore reconfiguration, canal construction, and connection of lake water systems in the area of impact. Three subsidence reports from the 1980s are also recorded within 500 meters of the collapse.

  2. Investigating the causality of changes in the landscape pattern of Lake Urmia basin, Iran using remote sensing and time series analysis.

    PubMed

    Mehrian, Majid Ramezani; Hernandez, Raul Ponce; Yavari, Ahmad Reza; Faryadi, Shahrzad; Salehi, Esmaeil

    2016-08-01

    Lake Urmia is the second largest hypersaline lake in the world in terms of surface area. In recent decades, the drop in water level of the lake has been one of the most important environmental issues in Iran. At present, the entire basin is threatened due to abrupt decline of the lake's water level and the consequent increase in salinity. Despite the numerous studies, there is still an ambiguity about the main cause of this environmental crisis. This paper is an attempt to detect the changes in the landscape structure of the main elements of the whole basin using remote sensing techniques and analyze the results against climate data with time series analysis for the purpose of achieving a more clarified illustration of processes and trends. Trend analysis of the different affecting factors indicates that the main cause of the drastic dry out of the lake is the huge expansion of irrigated agriculture in the basin between 1999 and 2014. The climatological parameters including precipitation and temperature cannot be the main reasons for reduced water level in the lake. The results show how the increase in irrigated agricultural area without considering the water resources limits can lead to a regional disaster. The approach used in this study can be a useful tool to monitor and assess the causality of environmental disaster.

  3. The Great Lakes' regional climate regimes

    NASA Astrophysics Data System (ADS)

    Sugiyama, Noriyuki

    For the last couple of decades, the Great Lakes have undergone rapid surface warming. In particular, the magnitude of the summer surface-warming trends of the Great Lakes have been much greater than those of surrounding land (Austin and Colman, 2007). Among the Great Lakes, the deepest Lake Superior exhibited the strongest warming trend in its annual, as well as summer surface water temperature. We find that many aspects of this behavior can be explained in terms of the tendency of deep lakes to exhibit multiple regimes characterized, under the same seasonally varying forcing, by the warmer and colder seasonal cycles exhibiting different amounts of wintertime lake-ice cover and corresponding changes in the summertime lake-surface temperatures. In this thesis, we address the problem of the Great Lakes' warming using one-dimensional lake modeling to interpret diverse observations of the recent lake behavior. (Abstract shortened by ProQuest.).

  4. Gavins Point Dam/Lewis and Clark Lake Master Plan. Missouri River, Nebraska and South Dakota: Update of Design Memorandum MG-123

    DTIC Science & Technology

    2004-12-01

    plover. These birds nest on barren sandbars close to the water surface downstream from the Gavins Point Dam on the Missouri National Recreational...nest on the barren sand and gravel beaches of the Great Gavins Point Dam/Lewis and Clark Lake Master Plan Update...Nebraska. The four Iowa counties (Pottawattamie, Plymouth , Sioux, Woodbury) within the primary market area had a population of 248,019, which contributed

  5. Occurrence, distribution and risk assessment of organophosphate esters in surface water and sediment from a shallow freshwater Lake, China.

    PubMed

    Xing, Liqun; Zhang, Qin; Sun, Xu; Zhu, Hongxia; Zhang, Shenghu; Xu, Huaizhou

    2018-04-30

    Organophosphate esters (OPEs) are ubiquitous in the environment and pose a potential threat to ecosystem and human health. This study investigated the concentrations, distributions and risk of 12 OPEs in surface water and sediment from Luoma Lake, Fangting River and Yi River. Solid-phase extraction (SPE) method were used to extract OPEs from water samples, ultrasonic process and SPE method were used to extract OPEs from sediment samples, and the extracts were finally analyzed using the HPLC-MS/MS. The results revealed that the median and maximum concentrations of ΣOPEs were 73.9 and 1066 ng/L in surface water, and were 28.7 and 35.9 ng/g in sediment, respectively. Tris(2-chloroethyl) phosphate (TCEP) and trimethyl phosphate (TMP) were the most abundant OPEs in the surface water with median concentrations of 24.3 and 16.4 ng/L in Luoma Lake, respectively. Triethyl phosphate (TEP) was the most abundant OPE in the sediment with a median concentrations of 28.9 ng/g. However, tricresyl phosphate (TCrP) and ethylhexyl diphenyl phosphate (EHDPP) predominantly contributed to the ecological risk with respective median risk quotients 0.07 and 0.01 for surface water in Luoma Lake. TEP and TCrP were the most significant contributors to the ecological risk with respective median risk quotients of 6.4 × 10 -4 and 5.6 × 10 -4 for sediment. It was also found that inflowing Fangting River could be the major pollution source to Luoma Lake. The no-cancer and carcinogenic risks of OPEs were lower than the theoretical threshold of risk. The study found that the ecological and human health risks due to the exposure to OPEs were currently acceptable. In other words, the Luoma Lake was relatively safer to use as a drinking water source in urban areas in the context of OPEs pollution. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Water-level altitudes 2015 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2014 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Kasmarek, Mark C.; Ramage, Jason K.; Houston, Natalie A.; Johnson, Michaela R.; Schmidt, Tiffany S.

    2015-01-01

    Compaction of subsurface sediments (mostly in the fine-grained silt and clay layers) composing the Chicot and Evangeline aquifers was recorded continuously by using analog technology at the 13 borehole extensometers at 11 sites that were either activated or installed between 1973 and 1980. For the period of record beginning in 1973 (or later depending on activation or installation date) and ending in December 2014, measured cumulative compaction at the 13 extensometers ranged from 0.101 ft at the Texas City-Moses Lake extensometer to 3.668 ft at the Addicks extensometer. During 2014, a total of 10 of the 13 extensometers recorded a slight net decrease of land-surface elevation; the extensometers at the Lake Houston and Clear Lake (shallow) sites recorded slight net increases of land-surface elevation, and the extensometer at the Texas City-Moses Lake site recorded no change in elevation. The rate of compaction varies from site to site because of differences in rates of groundwater withdrawal in the areas adjacent to each extensometer site and differences among sites in the ratios of sand, silt, and clay and compressibilities of the subsurface sediments. It is not appropriate, therefore, to extrapolate or infer a rate of compaction for an adjacent area on the basis of the rate of compaction measured at nearby extensometers.

  7. Combined use of frequency‐domain electromagnetic and electrical resistivity surveys to delineate the freshwater/saltwater interface near saline lakes in the Nebraska Sand Hills, Nebraska, USA

    USGS Publications Warehouse

    Ong, John T.; White, Eric A.; Lane, John W.; Halihan, Todd; Zlotnik, Vitaly A; Butler, Dwain K.

    2009-01-01

    We investigate the use of frequency‐domain electromagnetic (FDEM) and electrical resistivity (ER) surveys for rapid and detailed characterization of the direction of lake‐aquifer fluxes and the configuration of salt plumes generated from saline lakes. This methodology was developed and applied at several lakes in the Nebraska Sand Hills, Nebraska, in an area with both freshwater and saline lakes hydraulically connected to the freshwater surficial aquifer. The FDEM survey was conducted by mounting the instrument on a fiberglass cart towed by an all‐terrain vehicle. The towed FDEM surveys covered about 25 km per day and served as a reconnaissance method for choosing locations for the more quantitative and detailed ER surveys. Around the saline lakes, areas with high electrical conductivity are consistent with the regional direction of ground‐water flow. Lower electrical conductivity was measured around the freshwater lakes with anomalies correlating to a paleovalley axis inferred from previous studies. The efficacy of this geophysical approach is attributed to: (1) significant contrast in electrical conductivity between freshwater and saltwater, (2) near‐surface location of the freshwater/saltwater interface, (3) minimal cultural interference, and (4) relative homogeneity of the aquifer materials.

  8. Shallow and deep controls on lava lake surface motion at Kīlauea Volcano

    USGS Publications Warehouse

    Patrick, Matthew R.; Orr, Tim R.; Swanson, Don; Lev, Einat

    2016-01-01

    Lava lakes provide a rare window into magmatic behavior, and lake surface motion has been used to infer deeper properties of the magmatic system. At Halema'uma'u Crater, at the summit of Kīlauea Volcano, multidisciplinary observations for the past several years indicate that lava lake surface motion can be broadly divided into two regimes: 1) stable and 2) unstable. Stable behavior is driven by lava upwelling from deeper in the lake (presumably directly from the conduit) and is an intrinsic process that drives lava lake surface motion most of the time. This stable behavior can be interrupted by periods of unstable flow (often reversals) driven by spattering – a shallowly-rooted process often extrinsically triggered by small rockfalls from the crater wall. The bursting bubbles at spatter sources create void spaces and a localized surface depression which draws and consumes surrounding surface crust. Spattering is therefore a location of lava downwelling, not upwelling. Stable (i.e. deep, upwelling-driven) and unstable (i.e. shallow, spattering-driven) behavior often alternate through time, have characteristic surface velocities, flow directions and surface temperature regimes, and also correspond to changes in spattering intensity, outgassing rates, lava level and seismic tremor. These results highlight that several processes, originating at different depths, can control the motion of the lava lake surface, and long-term interdisciplinary monitoring is required to separate these influences. These observations indicate that lake surface motion is not always a reliable proxy for deeper lake or magmatic processes. From these observations, we suggest that shallow outgassing (spattering), not lake convection, drives the variations in lake motion reported at Erta 'Ale lava lake.

  9. Shallow and deep controls on lava lake surface motion at Kīlauea Volcano

    NASA Astrophysics Data System (ADS)

    Patrick, M. R.; Orr, T.; Swanson, D. A.; Lev, E.

    2016-12-01

    Lava lakes provide a rare window into magmatic behavior, and lake surface motion has been used to infer deeper properties of the magmatic system. At Halema'uma'u Crater, at the summit of Kīlauea Volcano, multidisciplinary observations for the past several years indicate that lava lake surface motion can be broadly divided into two regimes: 1) stable and 2) unstable. Stable behavior is driven by lava upwelling from deeper in the lake (presumably directly from the conduit) and is an intrinsic process that drives lava lake surface motion most of the time. This stable behavior can be interrupted by periods of unstable flow (often reversals) driven by spattering - a shallowly-rooted process often extrinsically triggered by small rockfalls from the crater wall. The bursting bubbles at spatter sources create void spaces and a localized surface depression which draws and consumes surrounding surface crust. Spattering is therefore a location of lava downwelling, not upwelling. Stable (i.e. deep, upwelling-driven) and unstable (i.e. shallow, spattering-driven) behavior often alternate through time, have characteristic surface velocities, flow directions and surface temperature regimes, and also correspond to changes in spattering intensity, outgassing rates, lava level and seismic tremor. These results highlight that several processes, originating at different depths, can control the motion of the lava lake surface, and long-term interdisciplinary monitoring is required to separate these influences. These observations indicate that lake surface motion is not always a reliable proxy for deeper lake or magmatic processes. From these observations, we suggest that shallow outgassing (spattering), not lake convection, drives the variations in lake motion reported at Erta 'Ale lava lake.

  10. Simulated response of the Sparta Aquifer to outcrop area recharge augmentation, southeastern Arkansas

    USGS Publications Warehouse

    Hays, Phillip D.

    2001-01-01

    Recharge augmentation by construction of infiltration impoundments is a potential means of increasing aquifer water levels and aquifer yield that is under consideration for the Sparta aquifer in southeastern Arkansas. The aquifer is a major water resource for municipal, industrial, and agricultural uses, and approximately 287 million gallons per day was pumped from the aquifer in Arkansas in 1995; this is double the amount pumped in 1975. Historically, the Sparta aquifer has provided abundant water of high quality. In recent years, however, the demand for water in some areas has resulted in withdrawals from the Sparta that significantly exceed recharge to the aquifer, and considerable declines have occurred in the potentiometric surface. To better manage the Sparta aquifer, water users in Arkansas are evaluating and implementing a variety of management practices and assessing alternative, surface-water sources to reduce stress upon the Sparta aquifer. One approach to managing and maximizing use of the Sparta aquifer is augmenting recharge to the aquifer by construction of infiltration lakes or canals within the recharge area. The basic concept of augmented recharge is simply to increase the amount of water being introduced into the aquifer so that more water will be available for use. Ground-water flow model simulations were conducted to assess the effectiveness of constructing lakes or canals to augment recharge. Results show that construction of five new lakes in the Sparta recharge area upgradient from major pumping centers or construction of a series of canals along the length of the recharge area yield notable benefit to aquifer conditions when compared with simulations entailing no augmentation of recharge. Augmentation of recharge in the Sparta aquifer with emplacement of lakes provides slight increase to aquifer water levels. The presence of the lakes increased simulated aquifer water levels 0.5 foot or more across a broad area comprising all or a substantial part of 19 counties after the 30-year simulation period. Substantial increases of 5 feet or greater are limited to a smaller area proximal to the lakes. Increases of 5 feet or more are seen in El Dorado, Pine Bluff, and Stuttgart. The positive effect of the lakes on aquifer water levels is rapidly realized after emplacement of the lakes. For example, in the El Dorado area more than 3 feet of a total of 8 feet of water-level increase is seen in the first 5 years of the simulation; in the Pine Bluff area 9 feet of a total of 16 feet of increase occurs within 5 years. Sustainable yield from the aquifer could be expected to be increased within the zone of influence of the lakes. Augmentation of recharge in the Sparta aquifer with emplacement of canals provides considerable increase of aquifer water levels. The zone of influence in the aquifer with canal-augmented recharge extends from the recharge area eastward to the Mississippi River. Aquifer water levels exhibit an increase of 5 feet or more across a broad area comprising all or a substantial part of 15 counties. Increases of 20 feet or more are seen in El Dorado, Pine Bluff, and Stuttgart. The amount of water moving into the aquifer is substantially increased under this scenario, and the amount of water removed from storage is decreased, thereby, increasing aquifer conditions considerably. Sustainable yield from the aquifer could be expected to be greater within the zone of influence of the canals as compared to either the scenario without recharge augmentation or recharge augmentation with lakes. The effect of the canal on aquifer water levels is rapidly realized after emplacement of the canals. For example, in the El Dorado area, 22 feet of a total of 30 feet of increase is seen in the first 5 years of the simulation; in the Pine Bluff area, 15 feet of a total of 24 feet of increase occurs within 5 years. As constructed, the model simulations imply that any lakes or canals constructed would maintain exce

  11. Sampling protocol for monitoring abiotic and biotic characteristics of mountain ponds and lakes

    USGS Publications Warehouse

    Hoffman, Robert L.; Tyler, Torrey J.; Larson, Gary L.; Adams, Michael J.; Wente, Wendy; Galvan, Stephanie

    2005-01-01

    This document describes field techniques and procedures used for sampling mountain ponds and lakes. These techniques and procedures will be used primarily to monitor, as part of long-term programs in National Parks and other protected areas, the abiotic and biotic characteristics of naturally occurring permanent montane lentic systems up to 75 ha in surface area. However, the techniques and procedures described herein also can be used to sample temporary or ephemeral montane lentic sites. Each Standard Operating Procedure (SOP) section addresses a specific component of the limnological investigation, and describes in detail field sampling methods pertaining to parameters to be measured for each component.

  12. Estimation of reservoir storage capacity using multibeam sonar and terrestrial lidar, Randy Poynter Lake, Rockdale County, Georgia, 2012

    USGS Publications Warehouse

    Lee, K.G.

    2013-01-01

    The U.S. Geological Survey, in cooperation with the Rockdale County Department of Water Resources, conducted a bathymetric and topographic survey of Randy Poynter Lake in northern Georgia in 2012. The Randy Poynter Lake watershed drains surface area from Rockdale, Gwinnett, and Walton Counties. The reservoir serves as the water supply for the Conyers-Rockdale Big Haynes Impoundment Authority. The Randy Poynter reservoir was surveyed to prepare a current bathymetric map and determine storage capacities at specified water-surface elevations. Topographic and bathymetric data were collected using a marine-based mobile mapping unit to estimate storage capacity. The marine-based mobile mapping unit operates with several components: multibeam echosounder, singlebeam echosounder, light detection and ranging system, navigation and motion-sensing system, and data acquisition computer. All data were processed and combined to develop a triangulated irregular network, a reservoir capacity table, and a bathymetric contour map.

  13. A comparison of charcoal measurements for reconstruction of Mediterranean paleo-fire frequency in the mountains of Corsica

    NASA Astrophysics Data System (ADS)

    Leys, Bérangère; Carcaillet, Christopher; Dezileau, Laurent; Ali, Adam A.; Bradshaw, Richard H. W.

    2013-05-01

    Fire-history reconstructions inferred from sedimentary charcoal records are based on measuring sieved charcoal fragment area, estimating fragment volume, or counting fragments. Similar fire histories are reconstructed from these three approaches for boreal lake sediment cores, using locally defined thresholds. Here, we test the same approach for a montane Mediterranean lake in which taphonomical processes might differ from boreal lakes through fragmentation of charcoal particles. The Mediterranean charcoal series are characterized by highly variable charcoal accumulation rates. Results there indicate that the three proxies do not provide comparable fire histories. The differences are attributable to charcoal fragmentation. This could be linked to fire type (crown or surface fires) or taphonomical processes, including charcoal transportation in the catchment area or in the sediment. The lack of correlation between the concentration of charcoal and of mineral matter suggests that fragmentation is not linked to erosion. Reconstructions based on charcoal area are more robust and stable than those based on fragment counts. Area-based reconstructions should therefore be used instead of the particle-counting method when fragmentation may influence the fragment abundance.

  14. Application of the Local Grid Refinement package to an inset model simulating the interactions of lakes, wells, and shallow groundwater, northwestern Waukesha County, Wisconsin

    USGS Publications Warehouse

    Feinstein, D.T.; Dunning, C.P.; Juckem, P.F.; Hunt, R.J.

    2010-01-01

    Groundwater use from shallow, high-capacity wells is expected to increase across southeastern Wisconsin in the next decade (2010-2020), owing to residential and business growth and the need for shallow water to be blended with deeper water of lesser quality, containing, for example, excessive levels of radium. However, this increased pumping has the potential to affect surface-water features. A previously developed regional groundwater-flow model for southeastern Wisconsin was used as the starting point for a new model to characterize the hydrology of part of northwestern Waukesha County, with a particular focus on the relation between the shallow aquifer and several area lakes. An inset MODFLOW model was embedded in an updated version of the original regional model. Modifications made within the inset model domain include finer grid resolution; representation of Beaver, Pine, and North Lakes by use of the LAK3 package in MODFLOW; and representation of selected stream reaches with the SFR package. Additionally, the inset model is actively linked to the regional model by use of the recently released Local Grid Refinement package for MODFLOW-2005, which allows changes at the regional scale to propagate to the local scale and vice versa. The calibrated inset model was used to simulate the hydrologic system in the Chenequa area under various weather and pumping conditions. The simulated model results for base conditions show that groundwater is the largest inflow component for Beaver Lake (equal to 59 percent of total inflow). For Pine and North Lakes, it is still an important component (equal, respectively, to 16 and 5 percent of total inflow), but for both lakes it is less than the contribution from precipitation and surface water. Severe drought conditions (simulated in a rough way by reducing both precipitation and recharge rates for 5 years to two-thirds of base values) cause correspondingly severe reductions in lake stage and flows. The addition of a test well south of Chenequa at a pumping rate of 47 gal/min from a horizon approximately 200 feet below land surface has little effect on lake stages or flows even after 5 years of pumping. In these scenarios, the stage and the surface-water outflow from Pine Lake are simulated to decrease by only 0.03 feet and 3 percent, respectively, relative to base conditions. Likely explanations for these limited effects are the modest pumping rate simulated, the depth of the test well, and the large transmissivity of the unconsolidated aquifer, which allows the well to draw water from upstream along the bedrock valley and to capture inflow from the Bark River. However, if the pumping rate of the test well is assumed to increase to 200 gal/min, the decrease in simulated Pine Lake outflow is appreciably larger, dropping by 14 percent relative to base-flow conditions.

  15. Occurrence of methylmercury in Lake Valencia, Venezuela

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jaffe, R.; Cai, Y.; West-Thomas, J.

    1997-12-31

    The presence of mercury in the environment has received renewed attention during recent years. This is in part due to the known human health and ecological effects of the highly toxic organomercury compounds, and to the fact that novel and improved analytical techniques such as atomic fluorescence spectroscopy (AFS) and capillary chromatography with AFS detection, have enhanced significantly the detection of trace amounts of mercury and organo mercurials in environmental samples. Such techniques have allowed for a better understanding of the biogeochemical cycle of mercury in the aquatic environment. This paper reports on the presence of methylmercury in the watermore » column and sediments of a hyper-eutrophic lake. Lake Valencia is a freshwater lake located in North-Central Venezuela`s Aragua Valley. The lake`s surface area covers approximately 350 km{sup 2}, with a mean depth of 19 m and a maximum depth of 41 m. Due to the discharge of waste waters from the cities of Maracay and Valencia, as well as from other smaller villages and agricultural areas in its watershed, Lake Valencia has become hyper-eutrophic. The population of phytoplankton, particularly of blue-green algae, has increased dramatically during the last two decades resulting in anoxic conditions in the lower part of the water column during most of the year. In addition, concentrations of anthropogenic chemicals, including heavy metals, have increased in the Lake during the last four decades. 15 refs., 2 figs.« less

  16. Hydrogeologic framework of the North Fork and surrounding areas, Long Island, New York

    USGS Publications Warehouse

    Schubert, Christopher E.; Bova, Richard G.; Misut, Paul E.

    2004-01-01

    Ground water on the North Fork of Long Island is the sole source of drinking water, but the supply is vulnerable to saltwater intrusion and upconing in response to heavy pumping. Information on the area's hydrogeologic framework is needed to analyze the effects of pumping and drought on ground-water levels and the position of the freshwater-saltwater interface. This will enable water-resource managers and water-supply purveyors to evaluate a wide range of water-supply scenarios to safely meet water-use demands. The extent and thickness of hydrogeologic units and position of the freshwater-saltwater interface were interpreted from previous work and from exploratory drilling during this study.The fresh ground-water reservoir on the North Fork consists of four principal freshwater flow systems (referred to as Long Island mainland, Cutchogue, Greenport, and Orient) within a sequence of unconsolidated Pleistocene and Late Cretaceous deposits. A thick glacial-lake-clay unit appears to truncate underlying deposits in three buried valleys beneath the northern shore of the North Fork. Similar glacial-lake deposits beneath eastern and east-central Long Island Sound previously were inferred to be younger than the surficial glacial deposits exposed along the northern shore of Long Island. Close similarities in thickness and upper-surface altitude between the glacial-lake-clay unit on the North Fork and the glacial-lake deposits in Long Island Sound indicate, however, that the two are correlated at least along the North Fork shore.The Matawan Group and Magothy Formation, undifferentiated, is the uppermost Cretaceous unit on the North Fork and constitutes the Magothy aquifer. The upper surface of this unit contains a series of prominent erosional features that can be traced beneath Long Island Sound and the North Fork. Northwest-trending buried ridges extend several miles offshore from areas southeast of Rocky Point and Horton Point. A promontory in the irregular, north-facing cuesta slope extends offshore from an area southwest of Mattituck Creek and James Creek. Buried valleys that trend generally southeastward beneath Long Island Sound extend onshore northeast of Hashamomuck Pond and east of Goldsmith Inlet.An undifferentiated Pleistocene confining layer, the lower confining unit, consists of apparently contiguous units of glacial-lake, marine, and nonmarine clay. This unit is more than 200 feet thick in buried valleys filled with glacial-lake clay along the northern shore, but elsewhere on the North Fork, it is generally less than 50 feet thick and presumably represents an erosional remnant of marine clay. Its upper surface is generally 75 feet or more below sea level where it overlies buried valleys, and is generally 100 feet or less below sea level in areas where marine clay has been identified.A younger unit of glacial-lake deposits, the upper confining unit, is a local confining layer and underlies a sequence of late Pleistocene moraine and outwash deposits. This unit is thickest (more than 45 feet thick) beneath two lowland areas--near Mattituck Creek and James Creek, and near Hashamomuck Pond--but pinches out close to the northern and southern shores and is locally absent in inland areas of the North Fork. Its upper-surface altitude generally rises to near sea level toward the southern shore.Freshwater in the Orient flow system is limited to the upper glacial aquifer above the top of the lower confining unit. The upper confining unit substantially impedes the downward flow of freshwater in inland parts of the Greenport flow system. Deep freshwater within the lower confining unit in the east-central part of the Cutchogue flow system probably is residual from an interval of lower sea level. The upper confining unit is absent or only a few feet thick in the west-central part of the Cutchogue flow system and does not substantially impede the downward flow of freshwater, but the lower confining unit probably impedes the downward flow of freshwater within a southeast-trending buried valley in this area.

  17. Evaporation estimation of rift valley lakes: comparison of models.

    PubMed

    Melesse, Assefa M; Abtew, Wossenu; Dessalegne, Tibebe

    2009-01-01

    Evapotranspiration (ET) accounts for a substantial amount of the water flux in the arid and semi-arid regions of the World. Accurate estimation of ET has been a challenge for hydrologists, mainly because of the spatiotemporal variability of the environmental and physical parameters governing the latent heat flux. In addition, most available ET models depend on intensive meteorological information for ET estimation. Such data are not available at the desired spatial and temporal scales in less developed and remote parts of the world. This limitation has necessitated the development of simple models that are less data intensive and provide ET estimates with acceptable level of accuracy. Remote sensing approach can also be applied to large areas where meteorological data are not available and field scale data collection is costly, time consuming and difficult. In areas like the Rift Valley regions of Ethiopia, the applicability of the Simple Method (Abtew Method) of lake evaporation estimation and surface energy balance approach using remote sensing was studied. The Simple Method and a remote sensing-based lake evaporation estimates were compared to the Penman, Energy balance, Pan, Radiation and Complementary Relationship Lake Evaporation (CRLE) methods applied in the region. Results indicate a good correspondence of the models outputs to that of the above methods. Comparison of the 1986 and 2000 monthly lake ET from the Landsat images to the Simple and Penman Methods show that the remote sensing and surface energy balance approach is promising for large scale applications to understand the spatial variation of the latent heat flux.

  18. Classification of freshwater ice conditions on the Alaskan Arctic Coastal Plain using ground penetrating radar and TerraSAR-X satellite data

    USGS Publications Warehouse

    Jones, Benjamin M.; Gusmeroli, Alessio; Arp, Christopher D.; Strozzi, Tazio; Grosse, Guido; Gaglioti, Benjamin V.; Whitman, Matthew S.

    2013-01-01

    Arctic freshwater ecosystems have responded rapidly to climatic changes over the last half century. Lakes and rivers are experiencing a thinning of the seasonal ice cover, which may increase potential over-wintering freshwater habitat, winter water supply for industrial withdrawal, and permafrost degradation. Here, we combined the use of ground penetrating radar (GPR) and high-resolution (HR) spotlight TerraSAR-X (TSX) satellite data (1.25 m resolution) to identify and characterize floating ice and grounded ice conditions in lakes, ponds, beaded stream pools, and an alluvial river channel. Classified ice conditions from the GPR and the TSX data showed excellent agreement: 90.6% for a predominantly floating ice lake, 99.7% for a grounded ice lake, 79.0% for a beaded stream course, and 92.1% for the alluvial river channel. A GIS-based analysis of 890 surface water features larger than 0.01 ha showed that 42% of the total surface water area potentially provided over-wintering habitat during the 2012/2013 winter. Lakes accounted for 89% of this area, whereas the alluvial river channel accounted for 10% and ponds and beaded stream pools each accounted for <1%. Identification of smaller landscape features such as beaded stream pools may be important because of their distribution and role in connecting other water bodies on the landscape. These findings advance techniques for detecting and knowledge associated with potential winter habitat distribution for fish and invertebrates at the local scale in a region of the Arctic with increasing stressors related to climate and land use change.

  19. 78 FR 27872 - Proposed Amendment of Class E Airspace; Salt Lake City, UT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-13

    ... System (GPS) and Instrument Landing System (ILS) or Localizer (LOC) standard instrument approach...: Paragraph 6005 Class E airspace areas extending upward from 700 feet or more above the surface of the earth...

  20. A Buoy for Continuous Monitoring of Suspended Sediment Dynamics

    PubMed Central

    Mueller, Philip; Thoss, Heiko; Kaempf, Lucas; Güntner, Andreas

    2013-01-01

    Knowledge of Suspended Sediments Dynamics (SSD) across spatial scales is relevant for several fields of hydrology, such as eco-hydrological processes, the operation of hydrotechnical facilities and research on varved lake sediments as geoarchives. Understanding the connectivity of sediment flux between source areas in a catchment and sink areas in lakes or reservoirs is of primary importance to these fields. Lacustrine sediments may serve as a valuable expansion of instrumental hydrological records for flood frequencies and magnitudes, but depositional processes and detrital layer formation in lakes are not yet fully understood. This study presents a novel buoy system designed to continuously measure suspended sediment concentration and relevant boundary conditions at a high spatial and temporal resolution in surface water bodies. The buoy sensors continuously record turbidity as an indirect measure of suspended sediment concentrations, water temperature and electrical conductivity at up to nine different water depths. Acoustic Doppler current meters and profilers measure current velocities along a vertical profile from the water surface to the lake bottom. Meteorological sensors capture the atmospheric boundary conditions as main drivers of lake dynamics. It is the high spatial resolution of multi-point turbidity measurements, the dual-sensor velocity measurements and the temporally synchronous recording of all sensors along the water column that sets the system apart from existing buoy systems. Buoy data collected during a 4-month field campaign in Lake Mondsee demonstrate the potential and effectiveness of the system in monitoring suspended sediment dynamics. Observations were related to stratification and mixing processes in the lake and increased turbidity close to a catchment outlet during flood events. The rugged buoy design assures continuous operation in terms of stability, energy management and sensor logging throughout the study period. We conclude that the buoy is a suitable tool for continuous monitoring of suspended sediment concentrations and general dynamics in fresh water bodies. PMID:24129017

  1. Bottom Characterization with High Resolution Sonar Data and Geochemical Analyses of an Uninvestigated Cone in Lagoa das Furnas on São Miguel Island, Azores Archipelago

    NASA Astrophysics Data System (ADS)

    Andersson, T.

    2015-12-01

    Lagoa das Furnas is a crater lake located in an area exposed to geohazards from earthquakes and volcanic activity on the island São Miguel in the Azores Archipelago. The Furnas volcanic center has a long history of earthquakes and volcanic activity. The area is relatively well studied except for the lake floor. Therefore, a high resolution geophysical and geological mapping survey was conducted at Lagoa das Furnas. Sidescan sonar was used to map the surface of the lake floor and single beam sonar was used to acquire sub-bottom profiles. In addition to the geophysical mapping, sediment surface sampling and core drilling were carried out followed by geochemical analyses of the retrieved material. The mapped data permitted a characterization of the floor of Lagoa das Furnas and revealed several volcanic features including fumarolic activity and a previously uninvestigated volcanic cone in the southern part of the lake. In order to unravel the origin of this cone several methods were applied, including analyses of tephra and minerals collected from the cone itself and from nearby deposits of two known eruptions, Furnas I and Furnas 1630. Sedimentological, petrological, geochemical and geochronological studies of pyroclastic deposits from the cone suggest a subaqueous eruption linked to the Furnas 1630 eruption. The chemistry of glass and crystal fragments sampled from the cone suggests that it is composed of more evolved magma than that of the main Furnas 1630, implying that the lake cone is likely a product of the last eruptional phase. According to historical records, two of three lakes were lost due the Furnas 1630 eruption. The results of this study show that the remaining lake is most likely Lagoa das Furnas, which consequently must have existed before the 1630 eruption.

  2. Analyzing landscape changes in the Bafa Lake Nature Park of Turkey using remote sensing and landscape structure metrics.

    PubMed

    Esbah, Hayriye; Deniz, Bulent; Kara, Baris; Kesgin, Birsen

    2010-06-01

    Bafa Lake Nature Park is one of Turkey's most important legally protected areas. This study aimed at analyzing spatial change in the park environment by using object-based classification technique and landscape structure metrics. SPOT 2X (1994) and ASTER (2005) images are the primary research materials. Results show that artificial surfaces, low maqui, garrigue, and moderately high maqui covers have increased and coniferous forests, arable lands, permanent crop, and high maqui covers have decreased; coniferous forest, high maqui, grassland, and saline areas are in a disappearance stage of the land transformation; and the landscape pattern is more fragmented outside the park boundaries. The management actions should support ongoing vegetation regeneration, mitigate transformation of vegetation structure to less dense and discontinuous cover, control the dynamics at the agricultural-natural landscape interface, and concentrate on relatively low but steady increase of artificial surfaces.

  3. Biological invasion by a benthivorous fish reduced the cover and species richness of aquatic plants in most lakes of a large North American ecoregion.

    PubMed

    Bajer, Przemyslaw G; Beck, Marcus W; Cross, Timothy K; Koch, Justine D; Bartodziej, William M; Sorensen, Peter W

    2016-12-01

    Biological invasions are projected to be the main driver of biodiversity and ecosystem function loss in lakes in the 21st century. However, the extent of these future losses is difficult to quantify because most invasions are recent and confounded by other stressors. In this study, we quantified the outcome of a century-old invasion, the introduction of common carp to North America, to illustrate potential consequences of introducing non-native ecosystem engineers to lakes worldwide. We used the decline in aquatic plant richness and cover as an index of ecological impact across three ecoregions: Great Plains, Eastern Temperate Forests and Northern Forests. Using whole-lake manipulations, we demonstrated that both submersed plant cover and richness declined exponentially as carp biomass increased such that plant cover was reduced to <10% and species richness was halved in lakes in which carp biomass exceeded 190 kg ha -1 . Using catch rates amassed from 2000+ lakes, we showed that carp exceeded this biomass level in 70.6% of Great Plains lakes and 23.3% of Eastern Temperate Forests lakes, but 0% of Northern Forests lakes. Using model selection analysis, we showed that carp was a key driver of plant species richness along with Secchi depth, lake area and human development of lake watersheds. Model parameters showed that carp reduced species richness to a similar degree across lakes of various Secchi depths and surface areas. In regions dominated by carp (e.g., Great Plains), carp had a stronger impact on plant richness than human watershed development. Overall, our analysis shows that the introduction of common carp played a key role in driving a severe reduction in plant cover and richness in a majority of Great Plains lakes and a large portion of Eastern Temperate Forests lakes in North America. © 2016 John Wiley & Sons Ltd.

  4. Earth Observations taken by the Expedition 21 Crew

    NASA Image and Video Library

    2009-11-14

    ISS021-E-026475 (14 Nov. 2009) --- Ounianga Lakes in the Sahara Desert, in the nation of Chad are featured in this image photographed by an Expedition 21 crew member on the International Space Station. This view features one of the largest of a series of ten, mostly fresh water lakes in the Ounianga basin in the heart of the Sahara Desert of northeastern Chad. According to scientists, the lakes are the remnant of a single large lake, probably tens of kilometers long that once occupied this remote area approximately 14,800 to 5,500 years ago. As the climate dried out during the subsequent millennia, the lake was reduced in size and large wind-driven sand dunes invaded the original depression dividing it into several smaller basins. The area shown in this image measures approximately 11 x 9 kilometers, with the dark water surfaces of the lake segregated almost completely by orange linear sand dunes that stream into the depression from the northeast. The almost year-round northeast winds and cloudless skies make for very high evaporation (an evaporation rate of greater than six meters per year has been measured in one of the nearby lakes). Despite this, only one of the ten lakes is saline. According to scientists, the reason for the apparent paradox of fresh water lakes in the heart of the desert lies in the fact that fresh water from a very large aquifer reaches the surface in the Ounianga depression in the form of the lakes. The aquifer is large enough to keep supplying the small lakes with water despite the high evaporation rate. Mats of floating reeds also reduce the evaporation in places. The lakes form a hydrological system that is unique in the Sahara Desert. Scientists believe the aquifer was charged with fresh water, and the large original lake evolved, during the so-called African Humid Period (approximately 14,800 to 5,500 years ago) when the West African summer monsoon was stronger than it is today. Associated southerly winds brought Atlantic moisture well north of modern limits, producing sufficient rainfall in the central Sahara to foster an almost complete savanna vegetation cover. Pollen data from lake sediments of the original 50-meters-deep Ounianga Lake suggests to scientists that a mild tropical climate with a wooded grassland savanna existed in the region. This vegetation association is now only encountered 300 kilometers further south. Ferns grew in the stream floodplains which must have been occasionally flooded. Even shrubs that now occur only on the very high, cool summits (greater than 2,900 meters, greater than 9,500 feet) of the Tibesti Mts. have been found in the Ounianga lake sediments.

  5. Earth Observations taken by the Expedition 13 crew

    NASA Image and Video Library

    2006-07-19

    ISS013-E-54243 (19 July 2006) --- Crater Lake, Oregon is featured in this image photographed by an Expedition 13 crewmember on the International Space Station. Crater Lake is formed from the caldera (collapsed magma chamber) of a former volcano known as Mount Mazama. Part of the Cascades volcanic chain, Mount Mazama is situated between the Three Sisters volcanoes to the north and Mount Shasta to the south. While considered a dormant volcano, Crater Lake is part of the United States Geological Survey Cascades Volcano Observatory seismic monitoring network. The dark blue water coloration is typical of the 592 meter (1943 feet) deep Crater Lake; light blue-green areas to the southeast of Wizard Island (along the southern crater rim) most probably correspond to particulates either on or just below the water surface. A light dusting of snow fills the summit cone of Wizard Island. Some of the older lava flows in the area are associated with Mount Scott to the east-southeast of the Lake. Water is lost only by evaporation and seepage, and is only replenished by rainwater and snowmelt from the surrounding crater walls. These processes help maintain minimal sediment input into the lake and exceptional water clarity. The Crater Lake ecosystem is of particular interest to ecologists because of its isolation from the regional landscape, and its overall pristine quality is important to recreational users of Crater Lake National Park (447,240 visitors in 2005). The United States National Park Service maintains programs to monitor changes (both natural and human impacts) to Crater Lake.

  6. The potential for catastrophic dam failure at Lake Nyos maar, Cameroon

    USGS Publications Warehouse

    Lockwood, J.P.; Costa, J.E.; Tuttle, M.L.; Nni, J.; Tebor, S.G.

    1988-01-01

    The upper 40 m of Lake Nyos is bounded on the north by a narrow dam of poorly consolidated pyroclastic rocks, emplaced during the eruptive formation of the Lake Nyos maar a few hundred years ago. This 50-m-wide natural dam is structurally weak and is being eroded at an uncertain, but geologically alarming, rate. The eventual failure of the dam could cause a major flood (estimated peak discharge, 17000 m3/s) that would have a tragic impact on downstream areas as far as Nigeria, 108 km away. This serious hazard could be eliminated by lowering the lake level, either by controlled removal of the dam or by construction of a 680-m-long drainage tunnel about 65 m below the present lake surface. Either strategy would also lessen the lethal effects of future massive CO2 gas releases, such as the one that occurred in August 1986. ?? 1988 Springer-Verlag.

  7. Late Quaternary sedimentary features of Bear Lake, Utah and Idaho

    USGS Publications Warehouse

    Smoot, J.P.

    2009-01-01

    Bear Lake sediments were predominantly aragonite for most of the Holocene, reflecting a hydrologically closed lake fed by groundwater and small streams. During the late Pleistocene, the Bear River flowed into Bear Lake and the lake waters spilled back into the Bear River drainage. At that time, sediment deposition was dominated by siliciclastic sediment and calcite. Lake-level fluctuation during the Holocene and late Pleistocene produced three types of aragonite deposits in the central lake area that are differentiated primarily by grain size, sorting, and diatom assemblage. Lake-margin deposits during this period consisted of sandy deposits including well-developed shoreface deposits on margins adjacent to relatively steep gradient lake floors and thin, graded shell gravel on margins adjacent to very low gradient lake-floor areas. Throughout the period of aragonite deposition, episodic drops in lake level resulted in erosion of shallow-water deposits, which were redeposited into the deeper lake. These sediment-focusing episodes are recognized by mixing of different mineralogies and crystal habits and mixing of a range of diatom fauna into poorly sorted mud layers. Lake-level drops are also indicated by erosional gaps in the shallow-water records and the occurrence of shoreline deposits in areas now covered by as much as 30 m of water. Calcite precipitation occurred for a short interval of time during the Holocene in response to an influx of Bear River water ca. 8 ka. The Pleistocene sedimentary record of Bear Lake until ca. 18 ka is dominated by siliciclastic glacial fl our derived from glaciers in the Uinta Mountains. The Bear Lake deep-water siliciclastic deposits are thoroughly bioturbated, whereas shallow-water deposits transitional to deltas in the northern part of the basin are upward-coarsening sequences of laminated mud, silt, and sand. A major drop in lake level occurred ca. 18 ka, resulting in subaerial exposure of the lake floor in areas now covered by over 40 m of water. The subaerial surfaces are indicated by root casts and gypsum-rich soil features. Bear Lake remained at this low state with a minor transgression until ca. 15 ka. A new influx of Bear River water produced a major lake transgression and deposited a thin calcite deposit. Bear Lake quickly dropped to a shallow-water state, accumulating a mixture of calcite and siliciclastic sediment that contains at least two intervals of root-disrupted horizons indicating lake-level drops to more than 40 m below the modern highstand. About 11,500 yr B.P., the lake level rose again through an influx of Bear River water producing another thin calcite layer. The Bear River ceased to flow into the basin and the lake salinity increased, resulting in the aragonite deposition that persisted until modern human activity. The climatic record of Bear Lake sediment is difficult to ascertain by using standard chemical and biological techniques because of variations in the inflow hydrology and the significant amount of erosion and redeposition of chemical and biological sediment components. Copyright ?? 2009 The Geological Society of America.

  8. Impact of lake breezes on ozone and nitrogen oxides in the Greater Toronto Area

    NASA Astrophysics Data System (ADS)

    Wentworth, G. R.; Murphy, J. G.; Sills, D. M. L.

    2015-05-01

    Meteorological and air quality datasets from summertime (May to September, 2010-2012) were analysed in order to assess the influence of lake-breeze circulations on pollutant levels in the Greater Toronto Area (GTA). While previous estimates of the frequency of summer days experiencing lake breezes range between 25 and 32 % for the GTA, a simple algorithm using surface meteorological observations suggested Lake Ontario breezes occurred on 56% of summer days, whereas a more reliable multiplatform approach yielded a frequency of 74%. Data from five air quality stations across the GTA were used to compare air quality on days during which a lake-breeze circulation formed ("lake breeze days") versus days when one did not ("non-lake breeze days"). Average daytime O3 maxima were 13.6-14.8 ppb higher on lake breeze days relative to non-lake breeze days. Furthermore, the Ontario Ambient Air Quality Criteria (AAQC) for 1-h average O3 (80 ppb) and 8-h average O3 (65 ppb) were exceeded only on lake breeze days and occurred on a total of 30 and 54 days throughout the study period, respectively. A causal link between lake-breeze circulations and enhanced O3 was identified by examining several days in which only some of the air quality sites were inside the lake-breeze circulation. O3 mixing ratios at sites located within the circulation were at least 30 ppb higher than sites outside the circulation, despite similar temperatures, cloud conditions and synoptic regimes across the region. Rapid O3 increases were concurrent with the arrival of the lake-breeze front, suggesting O3-rich air from over the lake is being advected inland throughout the day. Lake-breeze circulations were found to have less impact on nitrogen oxide (NOx) levels. Morning NOx was greater on lake breeze days, probably due to the stagnant conditions favourable for lake breeze formation. During the late afternoon, only inland sites experience increased NOx on lake breeze days, likely as a result of being downwind from near-shore city centres.

  9. Modeling lakes and reservoirs in the climate system

    USGS Publications Warehouse

    MacKay, M.D.; Neale, P.J.; Arp, C.D.; De Senerpont Domis, L. N.; Fang, X.; Gal, G.; Jo, K.D.; Kirillin, G.; Lenters, J.D.; Litchman, E.; MacIntyre, S.; Marsh, P.; Melack, J.; Mooij, W.M.; Peeters, F.; Quesada, A.; Schladow, S.G.; Schmid, M.; Spence, C.; Stokes, S.L.

    2009-01-01

    Modeling studies examining the effect of lakes on regional and global climate, as well as studies on the influence of climate variability and change on aquatic ecosystems, are surveyed. Fully coupled atmosphere-land surface-lake climate models that could be used for both of these types of study simultaneously do not presently exist, though there are many applications that would benefit from such models. It is argued here that current understanding of physical and biogeochemical processes in freshwater systems is sufficient to begin to construct such models, and a path forward is proposed. The largest impediment to fully representing lakes in the climate system lies in the handling of lakes that are too small to be explicitly resolved by the climate model, and that make up the majority of the lake-covered area at the resolutions currently used by global and regional climate models. Ongoing development within the hydrological sciences community and continual improvements in model resolution should help ameliorate this issue.

  10. Compounding Impacts of Climate Change and Increased Human Water Withdrawal on Urmia Lake Water Availability

    NASA Astrophysics Data System (ADS)

    Alborzi, A.; Moftakhari, H.; Azaranfar, A.; Mallakpour, I.; Ashraf, B.; AghaKouchak, A.

    2017-12-01

    In recent decades, climate change and increase in human water withdrawal, combined, have caused ecological degradation in several terminal lakes worldwide. Among them, the shallow and hyper-saline Urmia Lake in Iran has experienced about 6 meters drawdown in lake level and 80% reduction in surface area. Here, we assess the imposed stress on Urmia Basin's water availability and Lake's ecological condition in response to coupled climate change and human-induced water withdrawal. A generalized river basin decision support system model consisting network flow is developed to simulate the basin-lake interactions under a wide range of scenarios. This model explicitly includes water management infrastructure, reservoirs, and irrigation and municipal water use. Studied scenarios represent a wide range of historic climate and water use scenarios including a historical baseline, future increase in water demand, and also improved water efficiency. In this presentation, we show the lake's water level, as a measure of lake's ecological health, under the compounding effects of the climate condition (top-down) and water use (bottom-up) scenarios. This method illustrates what combinations lead to failure in meeting the lake's ecological level.

  11. High similarity between bacterioneuston and airborne bacterial community compositions in a high mountain lake area.

    PubMed

    Hervas, Anna; Casamayor, Emilio O

    2009-02-01

    The bacterioneuston (bacteria inhabiting the air-water interface) is poorly characterized and possibly forms a unique community in the aquatic environment. In high mountain lakes, the surface film is subjected to extreme conditions of life, suggesting the development of a specific and adapted bacterioneuston community. We have studied the surface film of a remote high mountain lake in the Pyrenees by cloning the PCR-amplified 16S rRNA gene and comparing with bacteria present in underlying waters (UW), and airborne bacteria from the dust deposited on the top of the snow pack. We did not detect unusual taxa in the neuston but rather very common and widespread bacterial groups. Betaproteobacteria and Actinobacteria accounted for >75% of the community composition. Other minor groups were Gammaproteobacteria (between 8% and 12%), Alphaproteobacteria (between 1% and 5%), and Firmicutes (1%). However, we observed segregated populations in neuston and UW for the different clades within each of the main phylogenetic groups. The soil bacterium Acinetobacter sp. was only detected in the snow-dust sample. Overall, higher similarities were found between bacterioneuston and airborne bacteria than between the former and bacterioplankton. The surface film in high mountain lakes appears as a direct interceptor of airborne bacteria useful for monitoring long-range bacterial dispersion.

  12. Geologic Map of Northeastern Seattle (Part of the Seattle North 7.5' x 15' Quadrangle), King County, Washington

    USGS Publications Warehouse

    Booth, Derek B.; Troost, Kathy Goetz; Shimel, Scott A.

    2009-01-01

    This geologic map, approximately coincident with the east half of the Seattle North 7.5 x 15' quadrangle (herein, informally called the 'Seattle NE map'), covers nearly half of the City of Seattle and reaches from Lake Washington across to the Puget Sound shoreline. Land uses are mainly residential, but extensive commercial districts are located in the Northgate neighborhood, adjacent to the University of Washington, and along the corridors of Aurora Avenue North and Lake City Way. Industrial activity is concentrated along the Lake Washington Ship Canal and around Lake Union. One small piece of land outside of the quadrangle boundaries, at the west edge of the Bellevue North quadrangle, is included on this map for geographic continuity. Conversely, a small area in the northeast corner of the Seattle North quadrangle, on the eastside of Lake Washington, is excluded from this map. Within the boundaries of the map area are two large urban lakes, including the most heavily visited park in the State of Washington (Green Lake Park); a stream (Thornton Creek) that still hosts anadromous salmon despite having its headwaters in a golfcourse and a shopping center; parts of three cities, with a combined residential population of about 300,000 people; and the region's premier research institution, the University of Washington. The north boundary of the map is roughly NE 168th Street in the cities of Shoreline and Lake Forest Park, and the south boundary corresponds to Mercer Street in Seattle. The west boundary is 15th Avenue W (and NW), and the east boundary is formed by Lake Washington. Elevations range from sea level to a maximum of 165 m (541 ft), the latter on a broad till-covered knob in the city of Shoreline near the northwest corner of the map. Previous geologic maps of this area include those of Waldron and others (1962), Galster and Laprade (1991), and Yount and others (1993). Seattle lies within the Puget Lowland, an elongate structural and topographic basin between the Cascade Range and Olympic Mountains. The Seattle area has been glaciated repeatedly during the past two million years by coalescing glaciers that advanced southward from British Columbia. The landscape we see today was molded by cyclic glacial scouring and deposition and later modified by landsliding and stream erosion. The last ice sheet reached the central Puget Sound region about 14,500 years ago, as measured by 14C dating, and it had retreated from this area by 13,650 14C yr B.P. (equivalent calendar years are about 17,600 and 16,600 years ago; Porter and Swanson, 1998). Seattle now sits atop a complex and incomplete succession of interleaved glacial and nonglacial deposits that overlie an irregular bedrock surface. These glacial and nonglacial deposits vary laterally in both texture and thickness, and they contain many local unconformities. In addition, they have been deformed by faults and folds, at least as recently as 1,100 years ago, and this deformation further complicates the geologic record. The landforms and near-surface deposits that cover much of the Seattle NE map area record a relatively brief, recent interval of the region's geologic history. The topography is dominated in the north by a broad, fluted, and south-sloping upland plateau, which gives way to a more complex set of elongated hills in the map's southern half. The valleys of Pipers Creek, Green Lake, and Thornton Creek mark the transition between these two topographic areas. Most of the uplands are mantled by a rolling surface of sand (unit Qva) and till (unit Qvt) deposited during the last occupation of the Puget Lowland by a continental ice sheet. Beneath these ice sheet deposits is a complex succession of older sediments that extends far below sea level across most of the map area. These older sediments are now locally exposed where modern erosion and landslides have sliced through the edge of the upland, and where subglacial processes apparently left these older sedimen

  13. Lake Afrera, a structural depression in the Northern Afar Rift (Red Sea).

    PubMed

    Bonatti, Enrico; Gasperini, Elia; Vigliotti, Luigi; Lupi, Luca; Vaselli, Orlando; Polonia, Alina; Gasperini, Luca

    2017-05-01

    The boundary between the African and Arabian plates in the Southern Red Sea region is displaced inland in the northern Afar rift, where it is marked by the Red Sea-parallel Erta Ale, Alaita, and Tat Ali volcanic ridges. The Erta Ale is offset by about 20 and 40 km from the two en echelon ridges to the south. The offset area is highly seismic and marked by a depression filled by lake Afrera, a saline body of water fed by hydrothermal springs. Acoustic bathymetric profiles show ≈80 m deep canyons parallel to the NNW shore of the lake, part of a system of extensional normal faults striking parallel to the Red Sea. This system is intersected by oblique structures, some with strike-slip earthquakes, in what might evolve into a transform boundary. Given that the lake's surface lies today about 112 m below sea level, the depressed (minus ≈190 m below sea level) lake's bottom area may be considered the equivalent of the "nodal deep" in slow-slip oceanic transforms. The chemistry of the lake is compatible with the water having originated from hydrothermal liquids that had reacted with evaporites and basalts, rather than residual from evaporation of sea water. Bottom sediments include calcitic grains, halite and gypsum, as well as ostracod and diatom tests. The lake's level appears to have dropped by over 10 m during the last ≈50 years, continuing a drying up trend of the last few thousand years, after a "wet" stage 9,800 and 7,800 years before present when according to Gasse (1973) Lake Afrera covered an area several times larger than at present. This "wet" stage corresponds to an early Holocene warm-humid climate that prevailed in Saharan and Sub Saharan Africa. Lake Abhé, located roughly 250 km south of Afrera, shows similar climate-driven oscillations of its level.

  14. Automated calculation of surface energy fluxes with high-frequency lake buoy data

    USGS Publications Warehouse

    Woolway, R. Iestyn; Jones, Ian D; Hamilton, David P.; Maberly, Stephen C; Muroaka, Kohji; Read, Jordan S.; Smyth, Robyn L; Winslow, Luke A.

    2015-01-01

    Lake Heat Flux Analyzer is a program used for calculating the surface energy fluxes in lakes according to established literature methodologies. The program was developed in MATLAB for the rapid analysis of high-frequency data from instrumented lake buoys in support of the emerging field of aquatic sensor network science. To calculate the surface energy fluxes, the program requires a number of input variables, such as air and water temperature, relative humidity, wind speed, and short-wave radiation. Available outputs for Lake Heat Flux Analyzer include the surface fluxes of momentum, sensible heat and latent heat and their corresponding transfer coefficients, incoming and outgoing long-wave radiation. Lake Heat Flux Analyzer is open source and can be used to process data from multiple lakes rapidly. It provides a means of calculating the surface fluxes using a consistent method, thereby facilitating global comparisons of high-frequency data from lake buoys.

  15. Operational tracking of lava lake surface motion at Kīlauea Volcano, Hawai‘i

    USGS Publications Warehouse

    Patrick, Matthew R.; Orr, Tim R.

    2018-03-08

    Surface motion is an important component of lava lake behavior, but previous studies of lake motion have been focused on short time intervals. In this study, we implement the first continuous, real-time operational routine for tracking lava lake surface motion, applying the technique to the persistent lava lake in Halema‘uma‘u Crater at the summit of Kīlauea Volcano, Hawai‘i. We measure lake motion by using images from a fixed thermal camera positioned on the crater rim, transmitting images to the Hawaiian Volcano Observatory (HVO) in real time. We use an existing optical flow toolbox in Matlab to calculate motion vectors, and we track the position of lava upwelling in the lake, as well as the intensity of spattering on the lake surface. Over the past 2 years, real-time tracking of lava lake surface motion at Halema‘uma‘u has been an important part of monitoring the lake’s activity, serving as another valuable tool in the volcano monitoring suite at HVO.

  16. Spatial variations in drainage efficiency in a boreal wetland environment as a function of lidar and radar-derived deviations from the regional hydraulic gradient

    NASA Astrophysics Data System (ADS)

    Hopkinson, C.; Brisco, B.; Chasmer, L.; Devito, K.; Montgomery, J. S.; Patterson, S.; Petrone, R. M.

    2017-12-01

    The dense forest cover of the Western Boreal Plains of northern Alberta is underlain by a mix of glacial moraines, sandy outwash sediments and clay plains possessing spatially variable hydraulic conductivities. The region is also characterised by a large number of post-glacial surface depression wetlands that have seasonally and topographically limited surface connectivity. Consequently, drainage along shallow regional hydraulic gradients may be dominated either by variations in surface geology or local variations in Et. Long-term government lake level monitoring is sparse in this region, but over a decade of hydrometeorological monitoring has taken place around the Utikuma Regional Study Area (URSA), a research site led by the University of Alberta. In situ lake and ground water level data are here combined with time series of airborne lidar and RadarSat II synthetic aperture radar (SAR) data to assess the spatial variability of water levels during late summer period characterised by flow recession. Long term Lidar data were collected or obtained by the authors in August of 2002, 2008, 2011 and 2016, while seasonal SAR data were captured approximately every 24 days during the summers of 2015, 2016 and 2017. Water levels for wetlands exceeding 100m2 in area across a north-trending 20km x 5km topographic gradient north of Utikuma Lake were extracted directly from the lidar and indirectly from the SAR. The recent seasonal variability in spatial water levels was extracted from SAR, while the lidar data illustrated more long term trends associated with land use and riparian vegetation succession. All water level data collected in August were combined and averaged at multiple scales using a raster focal statistics function to generate a long term spatial map of the regional hydraulic gradient and scale-dependent variations. Areas of indicated high and low drainage efficiency were overlain onto layers of landcover and surface geology to ascertain causal relationships. Areas associated with high spatial variability in water level illustrate reduced drainage connectivity, while areas of reduced variability indicate high surface connectivity and/or hydraulic conductivity. The hypothesis of surface geology controls on local wetland connectivity and landscape drainage efficiency is supported through this analysis.

  17. A review on anthropogenic impact to the Micro Prespa lake and its damages

    NASA Astrophysics Data System (ADS)

    Frasheri, N.; Pano, N.; Frasheri, A.; Beqiraj, G.; Bushati, S.; Taska, E.

    2012-04-01

    Paper presents the results of the integrated and multidisciplinary studies for investigation of the anthropogenic damages to Albanian part of the transborder Micro Prespa Lake. Remote sensing with Landsat images was used for identification of environmental changes in time for the period 1970 - 2010. Micro Prespa Lake is lake with international status, as Ramsar Convection, International Park and Special Protection Area-79/409/EEC. According to the studies, investigations and analyses, the following were concluded: Devolli River- Micro Prespa Lake irrigation system was not scientifically supported by environmental engineering, hydroeconomy and International Rights principles. It does work according to the projected parameters, and also, doesn't supply the agricultural needs. About of 10 % of the water volume, discharges by Devolli River in Micro Prespa Lake during the winter, is taken from this lake for the irrigation in summer. Great surface of Albanian part of Micro Prespa Lake is destroyed. The other part of the lake is atrophied and the habitat and biodiversity are damaged. Important and unique species of fish, birds and plants of national and international values are risked. The underground karstic connection ways for water circulation are blocked. There are ruining the historic values of the area, such the encient Treni cave from the Bronze Age. The Albanian part of the Micro Prespa Lake has been damaged by the human activities. A huge amount of 1,2 million cubic meters alluvium has been deposited on the lake bottom and lakeshore, which was transported by the Devolli River waters, since 1974. This river waters, rich in alluvium and organic coal material from outcropped geological formations, also absorbed free chemical toxic remains by the drainage of Devolli farm ground, which have changed the chemical features of the lake water and degrading it. Micro Prespa Lake communicates with Macro Prespa Lake, and together with Ohrid Lake. Blockage of underground karstic connection ways has diminished not only the components of the lake water balance, but also the decreasing yield of the underground springs, that supply the Ohrid lake and drinkable water springs. The Albanian part of the Micro Prespa Lake plays the role of a gigantic decanter. This is an unprecedented case, not only in Albanian but also in Balkan and World hydrography. Devolli river alluvium deposited in Micro Prespa Lake caused the otherwise of territory of Republic of Albania in this area. Albania will not have any part in this lake after some years. The social and public opinion in Albania, must be conscious for the otherwise of Albanian territory, which in the case of Micro Prespa Lake has a national and international negative effect on destructions of a transborder lake, defendey by Europian Convents.

  18. Diatoms in sediments of perennially ice-covered Lake Hoare, and implications for interpreting lake history in the McMurdo Dry Valleys of Antarctica

    USGS Publications Warehouse

    Spaulding, S.A.; McKnight, Diane M.; Stoermer, E.F.; Doran, P.T.

    1997-01-01

    Diatom assemblages in surficial sediments, sediment cores, sediment traps, and inflowing streams of perennially ice-covered Lake Hore, South Victorialand, Antarctica were examined to determine the distribution of diatom taxa, and to ascertain if diatom species composition has changed over time. Lake Hoare is a closed-basin lake with an area of 1.8 km2, maximum depth of 34 m, and mean depth of 14 m, although lake level has been rising at a rate of 0.09 m yr-1 in recent decades. The lake has an unusual regime of sediment deposition: coarse grained sediments accumulate on the ice surface and are deposited episodically on the lake bottom. Benthic microbial mats are covered in situ by the coarse episodic deposits, and the new surfaces are recolonized. Ice cover prevents wind-induced mixing, creating the unique depositional environment in which sediment cores record the history of a particular site, rather than a lake=wide integration. Shallow-water (<1 m) diatom assemblages (Stauroneis anceps, Navicula molesta, Diadesmis contenta var. parallela, Navicula peraustralis) were distinct from mid-depth (4-16 m) assemblages (Diadesmis contenta, Luticola muticopsis fo. reducta, Stauroneis anceps, Diadesmis contenta var. parallela, Luticola murrayi) and deep-water (2-31 m) assemblages (Luticola murrayi, Luticola muticopsis fo. reducta, Navicula molesta. Analysis of a sediment core (30 cm long, from 11 m water depth) from Lake Hoare revealed two abrupt changes in diatom assemblages. The upper section of the sediment core contained the greatest biomass of benthic microbial mat, as well as the greatest total abundance and diversity of diatoms. Relative abundances of diatoms in this section are similar to the surficial samples from mid-depths. An intermediate zone contained less organic material and lower densities of diatoms. The bottom section of core contained the least amount of microbial mat and organic material, and the lowest density of diatoms. The dominant process influencing species composition and abundance of diatom assemblages in the benthic microbial mats is episodic deposition of coarse sediment from the ice surface.

  19. Model Estimates of Pan-Arctic Lake and Wetland Methane Emissions

    NASA Astrophysics Data System (ADS)

    Chen, X.; Bohn, T. J.; Glagolev, M.; Maksyutov, S.; Lettenmaier, D. P.

    2012-12-01

    Lakes and wetlands are important sources of the greenhouse gases CO2 and CH4, whose emission rates are sensitive to climate. The northern high latitudes, which are especially susceptible to climate change, contain about 50% of the world's lakes and wetlands. With the predicted changes in the regional climate for this area within the next century, there is concern about a possible positive feedback resulting from greenhouse gas emissions (especially of methane) from the region's wetlands and lakes. To study the climate response to emissions from northern hemisphere lakes and wetlands, we have coupled a large-scale hydrology and carbon cycling model (University of Washington's Variable Infiltration Capacity model; VIC) with the atmospheric chemistry and transport model (CTM) of Japan's National Institute for Environmental Studies and have applied this modelling framework over the Pan-Arctic region. In particular, the VIC model simulates the land surface hydrology and carbon cycling across a dynamic lake-wetland continuum. The model includes a distributed wetland water table that accounts for microtopography and simulates variations in inundated area that are calibrated to match a passive microwave based inundation product. Per-unit-area carbon uptake and methane emissions have been calibrated using extensive in situ observations. In this paper, the atmospheric methane concentrations from a coupled run of VIC and CTM are calibrated and verified for the Pan-Arctic region with satellite observations from Aqua's Atmospheric Infrared Sounder (AIRS) and Envisat's Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) instruments. We examine relative emissions from lakes and wetlands, as well as their net greenhouse warming potential, over the last half-century across the Pan-Arctic domain. We also assess relative uncertainties in emissions from each of the sources.

  20. Validation of a model with climatic and flow scenario analysis: case of Lake Burrumbeet in southeastern Australia.

    PubMed

    Yihdego, Yohannes; Webb, John

    2016-05-01

    Forecast evaluation is an important topic that addresses the development of reliable hydrological probabilistic forecasts, mainly through the use of climate uncertainties. Often, validation has no place in hydrology for most of the times, despite the parameters of a model are uncertain. Similarly, the structure of the model can be incorrectly chosen. A calibrated and verified dynamic hydrologic water balance spreadsheet model has been used to assess the effect of climate variability on Lake Burrumbeet, southeastern Australia. The lake level has been verified to lake level, lake volume, lake surface area, surface outflow and lake salinity. The current study aims to increase lake level confidence model prediction through historical validation for the year 2008-2013, under different climatic scenario. Based on the observed climatic condition (2008-2013), it fairly matches with a hybridization of scenarios, being the period interval (2008-2013), corresponds to both dry and wet climatic condition. Besides to the hydrologic stresses uncertainty, uncertainty in the calibrated model is among the major drawbacks involved in making scenario simulations. In line with this, the uncertainty in the calibrated model was tested using sensitivity analysis and showed that errors in the model can largely be attributed to erroneous estimates of evaporation and rainfall, and surface inflow to a lesser. The study demonstrates that several climatic scenarios should be analysed, with a combination of extreme climate, stream flow and climate change instead of one assumed climatic sequence, to improve climate variability prediction in the future. Performing such scenario analysis is a valid exercise to comprehend the uncertainty with the model structure and hydrology, in a meaningful way, without missing those, even considered as less probable, ultimately turned to be crucial for decision making and will definitely increase the confidence of model prediction for management of the water resources.

Top