Inundation of a barrier island (Chandeleur Islands, Louisiana, USA) during a hurricane: Observed water-level gradients and modeled seaward sand transport

NASA Astrophysics Data System (ADS)

Sherwood, Christopher R.; Long, Joseph W.; Dickhudt, Patrick J.; Dalyander, P. Soupy; Thompson, David M.; Plant, Nathaniel G.

2014-07-01

Large geomorphic changes to barrier islands may occur during inundation, when storm surge exceeds island elevation. Inundation occurs episodically and under energetic conditions that make quantitative observations difficult. We measured water levels on both sides of a barrier island in the northern Chandeleur Islands during inundation by Hurricane Isaac. Wind patterns caused the water levels to slope from the bay side to the ocean side for much of the storm. Modeled geomorphic changes during the storm were very sensitive to the cross-island slopes imposed by water-level boundary conditions. Simulations with equal or landward sloping water levels produced the characteristic barrier island storm response of overwash deposits or displaced berms with smoother final topography. Simulations using the observed seaward sloping water levels produced cross-barrier channels and deposits of sand on the ocean side, consistent with poststorm observations. This sensitivity indicates that accurate water-level boundary conditions must be applied on both sides of a barrier to correctly represent the geomorphic response to inundation events. More broadly, the consequence of seaward transport is that it alters the relationship between storm intensity and volume of landward transport. Sand transported to the ocean side may move downdrift, or aid poststorm recovery by moving onto the beach face or closing recent breaches, but it does not contribute to island transgression or appear as an overwash deposit in the back-barrier stratigraphic record. The high vulnerability of the Chandeleur Islands allowed us to observe processes that are infrequent but may be important at other barrier islands.

Observational evidence for volcanic impact on sea level and the global water cycle

PubMed Central

Grinsted, A.; Moore, J. C.; Jevrejeva, S.

2007-01-01

It has previously been noted that there are drops in global sea level (GSL) after some major volcanic eruptions. However, observational evidence has not been convincing because there is substantial variability in the global sea level record over periods similar to those at which we expect volcanoes to have an impact. To quantify the impact of volcanic eruptions we average monthly GSL data from 830 tide gauge records around five major volcanic eruptions. Surprisingly, we find that the initial response to a volcanic eruption is a significant rise in sea level of 9 ± 3 mm in the first year after the eruption. This rise is followed by a drop of 7 ± 3 mm in the period 2–3 years after the eruption relative to preeruption sea level. These results are statistically robust and no particular volcanic eruption or ocean region dominates the signature we find. Neither the drop nor especially the rise in GSL can be explained by models of lower oceanic heat content. We suggest that the mechanism is a transient disturbance of the water cycle with a delayed response of land river runoff relative to ocean evaporation and global precipitation that affects global sea level. The volcanic impact on the water cycle and sea levels is comparable in magnitude to that of a large El Niño–La Niña cycle, amounting to ≈5% of global land precipitation. PMID:18056644

Observational evidence for volcanic impact on sea level and the global water cycle.

PubMed

Grinsted, A; Moore, J C; Jevrejeva, S

2007-12-11

It has previously been noted that there are drops in global sea level (GSL) after some major volcanic eruptions. However, observational evidence has not been convincing because there is substantial variability in the global sea level record over periods similar to those at which we expect volcanoes to have an impact. To quantify the impact of volcanic eruptions we average monthly GSL data from 830 tide gauge records around five major volcanic eruptions. Surprisingly, we find that the initial response to a volcanic eruption is a significant rise in sea level of 9 +/- 3 mm in the first year after the eruption. This rise is followed by a drop of 7 +/- 3 mm in the period 2-3 years after the eruption relative to preeruption sea level. These results are statistically robust and no particular volcanic eruption or ocean region dominates the signature we find. Neither the drop nor especially the rise in GSL can be explained by models of lower oceanic heat content. We suggest that the mechanism is a transient disturbance of the water cycle with a delayed response of land river runoff relative to ocean evaporation and global precipitation that affects global sea level. The volcanic impact on the water cycle and sea levels is comparable in magnitude to that of a large El Niño-La Niña cycle, amounting to approximately 5% of global land precipitation.

CrowdWater - Can people observe what models need?

NASA Astrophysics Data System (ADS)

van Meerveld, I. H. J.; Seibert, J.; Vis, M.; Etter, S.; Strobl, B.

2017-12-01

CrowdWater (www.crowdwater.ch) is a citizen science project that explores the usefulness of crowd-sourced data for hydrological model calibration and prediction. Hydrological models are usually calibrated based on observed streamflow data but it is likely easier for people to estimate relative stream water levels, such as the water level above or below a rock, than streamflow. Relative stream water levels may, therefore, be a more suitable variable for citizen science projects than streamflow. In order to test this assumption, we held surveys near seven different sized rivers in Switzerland and asked more than 450 volunteers to estimate the water level class based on a picture with a virtual staff gauge. The results show that people can generally estimate the relative water level well, although there were also a few outliers. We also asked the volunteers to estimate streamflow based on the stick method. The median estimated streamflow was close to the observed streamflow but the spread in the streamflow estimates was large and there were very large outliers, suggesting that crowd-based streamflow data is highly uncertain. In order to determine the potential value of water level class data for model calibration, we converted streamflow time series for 100 catchments in the US to stream level class time series and used these to calibrate the HBV model. The model was then validated using the streamflow data. The results of this modeling exercise show that stream level class data are useful for constraining a simple runoff model. Time series of only two stream level classes, e.g. above or below a rock in the stream, were already informative, especially when the class boundary was chosen towards the highest stream levels. There was hardly any improvement in model performance when more than five water level classes were used. This suggests that if crowd-sourced stream level observations are available for otherwise ungauged catchments, these data can be used to constrain

Water resources data Virginia water year 2005 Volume 2. Ground-water level and ground-water quality records

USGS Publications Warehouse

Wicklein, Shaun M.; Powell, Eugene D.; Guyer, Joel R.; Owens, Joseph A.

2006-01-01

Water-resources data for the 2005 water year for Virginia consist of records of water levels and water quality of ground-water wells. This report (Volume 2. Ground-Water-Level and Ground-Water-Quality Records) contains water levels at 349 observation wells and water quality at 29 wells. Locations of these wells are shown on figures 3 through 8. The data in this report represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Virginia.

Are fluoride levels in drinking water associated with hypothyroidism prevalence in England? A large observational study of GP practice data and fluoride levels in drinking water.

PubMed

Peckham, S; Lowery, D; Spencer, S

2015-07-01

While previous research has suggested that there is an association between fluoride ingestion and the incidence of hypothyroidism, few population level studies have been undertaken. In England, approximately 10% of the population live in areas with community fluoridation schemes and hypothyroidism prevalence can be assessed from general practice data. This observational study examines the association between levels of fluoride in water supplies with practice level hypothyroidism prevalence. We used a cross-sectional study design using secondary data to develop binary logistic regression models of predictive factors for hypothyroidism prevalence at practice level using 2012 data on fluoride levels in drinking water, 2012/2013 Quality and Outcomes Framework (QOF) diagnosed hypothyroidism prevalence data, 2013 General Practitioner registered patient numbers and 2012 practice level Index of Multiple Deprivation scores. We found that higher levels of fluoride in drinking water provide a useful contribution for predicting prevalence of hypothyroidism. We found that practices located in the West Midlands (a wholly fluoridated area) are nearly twice as likely to report high hypothyroidism prevalence in comparison to Greater Manchester (non-fluoridated area). In many areas of the world, hypothyroidism is a major health concern and in addition to other factors-such as iodine deficiency-fluoride exposure should be considered as a contributing factor. The findings of the study raise particular concerns about the validity of community fluoridation as a safe public health measure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Ground-water levels in Wyoming, January 1986 through September 1995

USGS Publications Warehouse

Mason, J.P.; Green, S.L.

1996-01-01

Water levels were measured in a network of 81 observation wells in Wyoming as of September 1995. The wells are located mainly in areas where ground water is used in large quantities for irrigation or municipal purposes. Water-level data were collected at 74 of the 81 observation wells by Wyoming State Engineer personnel; data at theremaining 7 wells were collected by the U.S. Geological Survey. This report contains hydrographs for 81 observation wells showing water-level fluctuations from January 1986 through September 1995. Included in the report are maps showing location of the observation wells and tableslisting observation-well depths, use of water, principal geologic source, records available, and highest and lowest water levels for the period ofrecord.

C-band radar observes water level change in swamp forests

USGS Publications Warehouse

Lu, Zhong; Crane, Mike; Kwoun, Oh-Ig; Wells, Christopher J.; Rykhus, Russ

2005-01-01

Wetlands cover more than 4% of the Earth's land surface and interact with hydrologic, biogeochemical, and sediment transport processes that are fundamental in understanding ecological and climatic changes [Alsdorf et al, 2003; Prigent et al., 2001 ; Melack and Forsberg, 2000;Dunne et al., 1998]. Measurement of water level changes in wetlands, and consequently of changes in water storage capacity, provides a required input for hydrologic models, and is required to comprehensively assess flood hazards [e.g., Coe, 1998].

Ground-water levels in Wyoming, 1976 through 1985

USGS Publications Warehouse

Kennedy, H.I.; Oberender, C.B.

1987-01-01

Groundwater levels are measured periodically in a network of 84 observation wells in Wyoming, mostly in areas where groundwater is used in large quantities for irrigation or municipal purposes. The program is conducted by the U.S. Geological Survey in cooperation with the Wyoming State Engineer and the Wyoming Economic Development and Stabilization Board. This report contains hydrographs for 84 observation wells showing water-level fluctuations from 1976 through 1985. Also included in the report are maps showing locations of observation wells and tables listing well depths, use of water, geologic source, records available, and highest and lowest water levels for the period of record. (USGS)

Ground-water levels in observation wells in Oklahoma, 1982-83 climatic years

USGS Publications Warehouse

Goemaat, R.L.; Mize, L.D.; Spiser, D.E.

1984-01-01

In the 1982-83 climatic years, the U.S. Geological Survey, in cooperation with the Oklahoma Water Resources, collected ground-water level data in Oklahoma from 1,087 sites in 77 counties. This report presents those data points.

Water levels shape fishing participation in flood-control reservoirs

USGS Publications Warehouse

Miranda, Leandro E.; Meals, K. O.

2013-01-01

We examined the relationship between fishing effort (hours fished) and average March–May water level in 3 flood control reservoirs in Mississippi. Fishing effort increased as water level rose, peaked at intermediate water levels, and decreased at high water levels. We suggest that the observed arched-shaped relationship is driven by the shifting influence of fishability (adequacy of the fishing circumstances from an angler's perspective) and catch rate along a water level continuum. Fishability reduces fishing effort during low water, despite the potential for higher catch rates. Conversely, reduced catch rates and fishability at high water also curtail effort. Thus, both high and low water levels seem to discourage fishing effort, whereas anglers seem to favor intermediate water levels. Our results have implications for water level management in reservoirs with large water level fluctuations.

Can we use Earth Observations to improve monthly water level forecasts?

NASA Astrophysics Data System (ADS)

Slater, L. J.; Villarini, G.

2017-12-01

Dynamical-statistical hydrologic forecasting approaches benefit from different strengths in comparison with traditional hydrologic forecasting systems: they are computationally efficient, can integrate and `learn' from a broad selection of input data (e.g., General Circulation Model (GCM) forecasts, Earth Observation time series, teleconnection patterns), and can take advantage of recent progress in machine learning (e.g. multi-model blending, post-processing and ensembling techniques). Recent efforts to develop a dynamical-statistical ensemble approach for forecasting seasonal streamflow using both GCM forecasts and changing land cover have shown promising results over the U.S. Midwest. Here, we use climate forecasts from several GCMs of the North American Multi Model Ensemble (NMME) alongside 15-minute stage time series from the National River Flow Archive (NRFA) and land cover classes extracted from the European Space Agency's Climate Change Initiative 300 m annual Global Land Cover time series. With these data, we conduct systematic long-range probabilistic forecasting of monthly water levels in UK catchments over timescales ranging from one to twelve months ahead. We evaluate the improvement in model fit and model forecasting skill that comes from using land cover classes as predictors in the models. This work opens up new possibilities for combining Earth Observation time series with GCM forecasts to predict a variety of hazards from space using data science techniques.

WaterML: an XML Language for Communicating Water Observations Data

NASA Astrophysics Data System (ADS)

Maidment, D. R.; Zaslavsky, I.; Valentine, D.

2007-12-01

One of the great impediments to the synthesis of water information is the plethora of formats used to publish such data. Each water agency uses its own approach. XML (eXtended Markup Languages) are generalizations of Hypertext Markup Language to communicate specific kinds of information via the internet. WaterML is an XML language for water observations data - streamflow, water quality, groundwater levels, climate, precipitation and aquatic biology data, recorded at fixed, point locations as a function of time. The Hydrologic Information System project of the Consortium of Universities for the Advancement of Hydrologic Science, Inc (CUAHSI) has defined WaterML and prepared a set of web service functions called WaterOneFLow that use WaterML to provide information about observation sites, the variables measured there and the values of those measurments. WaterML has been submitted to the Open GIS Consortium for harmonization with its standards for XML languages. Academic investigators at a number of testbed locations in the WATERS network are providing data in WaterML format using WaterOneFlow web services. The USGS and other federal agencies are also working with CUAHSI to similarly provide access to their data in WaterML through WaterOneFlow services.

Ground-water levels in Wyoming, 1978 through September 1987

USGS Publications Warehouse

Kennedy, H.I.; Green, S.L.

1988-01-01

Groundwater levels are measured periodically in a network of 95 observation wells in Wyoming, mostly in areas where groundwater is used in large quantities for irrigation or municipal purposes. The program is conducted by the U.S. Geological Survey in cooperation with the Wyoming State Engineer and the Wyoming Economic Development and Stabilization Board. This report contains hydrographs for 95 observation wells showing water level fluctuations from 1978 through September 1987. Also included in the report are maps showing locations of observation wells and tables listing well depths, use of water, geologic source, records available, and highest and lowest water levels for the period of record. (USGS)

Fluctuations of ground-water levels in Lee County, Florida, in 1975 water year

USGS Publications Warehouse

O'Donnell, T. H.

1977-01-01

During the 1975 water year, rainfall was about average at Page Field, Florida, and from 20-25 percent below average at Lehigh Acres and Sanibel Island. Water levels were monitored in 57 observation wells in Lee County, Florida. Of the 23 wells that tap the water-table aquifer, one record high and 5 record low water levels were established. Record low water levels were established in 5 of 20 wells that tap the sandstone aquifer and in 1 of 10 wells that tap the upper Hawthorn aquifer. A record high water level was established in 1 of 3 wells that tap the lower Hawthorn aquifer. (Woodard-USGS)

Rising ground-water level in downtown Louisville, Kentucky, 1972-1977

USGS Publications Warehouse

Kernodle, J.M.; Whitesides, D.V.

1977-01-01

Ground-water levels in the alluvial aquifer in Louisville, Jefferson County, Kentucky, are rising at a rate which could cause wet basements and possible structural damage tc buildings in the downtown area by 1982. The predicted water level for 1982 is based on the nearly linear increase which has been observed from 1972 to 1977, during which period a rise of as much as 32 feet was recorded in water-level observation wells. Foremost among the possible causes of the rise is a decrease in withdrawal of ground water.

Ground displacements caused by aquifer-system water-level variations observed using interferometric synthetic aperture radar near Albuquerque, New Mexico

USGS Publications Warehouse

Heywood, Charles E.; Galloway, Devin L.; Stork, Sylvia V.

2002-01-01

Six synthetic aperture radar (SAR) images were processed to form five unwrapped interferometric (InSAR) images of the greater metropolitan area in the Albuquerque Basin. Most interference patterns in the images were caused by range displacements resulting from changes in land-surface elevation. Loci of land- surface elevation changes correlate with changes in aquifer-system water levels and largely result from the elastic response of the aquifer-system skeletal material to changes in pore-fluid pressure. The magnitude of the observed land-surface subsidence and rebound suggests that aquifer-system deformation resulting from ground-water withdrawals in the Albuquerque area has probably remained in the elastic (recoverable) range from July 1993 through September 1999. Evidence of inelastic (permanent) land subsidence in the Rio Rancho area exists, but its relation to compaction of the aquifer system is inconclusive because of insufficient water-level data. Patterns of elastic deformation in both Albuquerque and Rio Rancho suggest that intrabasin faults impede ground- water-pressure diffusion at seasonal time scales and that these faults are probably important in controlling patterns of regional ground-water flow.

Lessons: Science: "Sinkholes." Students Observe What Happens When Ice-Cold Water Mingles with Warm Water.

ERIC Educational Resources Information Center

VanCleave, Janice

2000-01-01

This intermediate-level science activity has students observe the effect of ice-cold water mingling with warm water. Water's behavior and movement alters with shifts in temperature. Students must try to determine how temperature affects the movement of water. Necessary materials include a pencil, cup, glass jar, masking tape, warm water, ice…

Ground-water levels and quality data for Georgia

USGS Publications Warehouse

,

1979-01-01

This report begins a publication format that will present annually both water-level and water-quality data in Georgia. In this format the information is presented in two-page units: the left page includes text which summarizes the information for an area or subject and the right page consists of one or more illustrations. Daily mean water-level fluctuations and trends are shown in hydrographs for the previous year and fluctuations for the monthly mean water level the previous 10 years for selected observation wells. The well data best illustrate the effects of changes in recharge and discharge in the various ground-water reservoirs in the State. A short narrative explains fluctuations and trends in each hydrograph. (Woodard-USGS)

Summary of the Ground-Water-Level Hydrologic Conditions in New Jersey 2006

USGS Publications Warehouse

Jones, Walter; Pope, Daryll

2007-01-01

Ground water is one of the Nation's most important natural resources. It provides about 40 percent of our Nation's public water supply. Currently, nearly one-half of New Jersey's drinking-water is supplied by over 300,000 wells that serve more than 4.3 million people (John P. Nawyn, U.S. Geological Survey, written commun., 2007). New Jersey's population is projected to grow by more than a million people by 2030 (U.S. Census Bureau, accessed March 2, 2006, at http://www.census.gov). As demand for water increases, managing the development and use of the ground-water resource so that the supply can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences is of paramount importance. This report describes the U.S. Geological Survey (USGS) New Jersey Water Science Center Observation Well Networks. Record low ground-water levels during water year 2006 (October 1, 2005 to September 30, 2006) are listed, and water levels in six selected water-table observation wells and three selected confined wells are shown in hydrographs. The report describes the trends in water levels in various confined aquifers in southern New Jersey and in water-table and fracture rock aquifers throughout the State. Web site addresses to access the data also are included. The USGS has operated a network of observation wells in New Jersey since 1923 for the purpose of monitoring ground-water-level changes throughout the State. Long-term systematic measurement of water levels in observation wells provides the data needed to evaluate changes in the ground-water resource over time. Records of ground-water levels are used to evaluate the effects of climate changes and water-supply development, to develop ground-water models, and to forecast trends.

Groundwater-level change and evaluation of simulated water levels for irrigated areas in Lahontan Valley, Churchill County, west-central Nevada, 1992 to 2012

USGS Publications Warehouse

Smith, David W.; Buto, Susan G.; Welborn, Toby L.

2016-09-14

The acquisition and transfer of water rights to wetland areas of Lahontan Valley, Nevada, has caused concern over the potential effects on shallow aquifer water levels. In 1992, water levels in Lahontan Valley were measured to construct a water-table map of the shallow aquifer prior to the effects of water-right transfers mandated by the Fallon Paiute-Shoshone Tribal Settlement Act of 1990 (Public Law 101-618, 104 Stat. 3289). From 1992 to 2012, approximately 11,810 water-righted acres, or 34,356 acre-feet of water, were acquired and transferred to wetland areas of Lahontan Valley. This report documents changes in water levels measured during the period of water-right transfers and presents an evaluation of five groundwater-flow model scenarios that simulated water-level changes in Lahontan Valley in response to water-right transfers and a reduction in irrigation season length by 50 percent.Water levels measured in 98 wells from 2012 to 2013 were used to construct a water-table map. Water levels in 73 of the 98 wells were compared with water levels measured in 1992 and used to construct a water-level change map. Water-level changes in the 73 wells ranged from -16.2 to 4.1 feet over the 20-year period. Rises in water levels in Lahontan Valley may correspond to annual changes in available irrigation water, increased canal flows after the exceptionally dry and shortened irrigation season of 1992, and the increased conveyance of water rights transferred to Stillwater National Wildlife Refuge. Water-level declines generally occurred near the boundary of irrigated areas and may be associated with groundwater pumping, water-right transfers, and inactive surface-water storage reservoirs. The largest water-level declines were in the area near Carson Lake.Groundwater-level response to water-right transfers was evaluated by comparing simulated and observed water-level changes for periods representing water-right transfers and a shortened irrigation season in areas near Fallon

Terrestrial Waters and Sea Level Variations on Interannual Time Scale

NASA Technical Reports Server (NTRS)

Llovel, W.; Becker, M.; Cazenave, A.; Jevrejeva, S.; Alkama, R.; Decharme, B.; Douville, H.; Ablain, M.; Beckley, B.

2011-01-01

On decadal to multi-decadal time scales, thermal expansion of sea waters and land ice loss are the main contributors to sea level variations. However, modification of the terrestrial water cycle due to climate variability and direct anthropogenic forcing may also affect sea level. For the past decades, variations in land water storage and corresponding effects on sea level cannot be directly estimated from observations because these are almost non-existent at global continental scale. However, global hydrological models developed for atmospheric and climatic studies can be used for estimating total water storage. For the recent years (since mid-2002), terrestrial water storage change can be directly estimated from observations of the GRACE space gravimetry mission. In this study, we analyse the interannual variability of total land water storage, and investigate its contribution to mean sea level variability at interannual time scale. We consider three different periods that, each, depend on data availability: (1) GRACE era (2003-2009), (2) 1993-2003 and (3) 1955-1995. For the GRACE era (period 1), change in land water storage is estimated using different GRACE products over the 33 largest river basins worldwide. For periods 2 and 3, we use outputs from the ISBA-TRIP (Interactions between Soil, Biosphere, and Atmosphere-Total Runoff Integrating Pathways) global hydrological model. For each time span, we compare change in land water storage (expressed in sea level equivalent) to observed mean sea level, either from satellite altimetry (periods 1 and 2) or tide gauge records (period 3). For each data set and each time span, a trend has been removed as we focus on the interannual variability. We show that whatever the period considered, interannual variability of the mean sea level is essentially explained by interannual fluctuations in land water storage, with the largest contributions arising from tropical river basins.

Validation of a Ground-Water Flow Model of the Mississippi River Valley Alluvial Aquifer Using Water-Level and Water-Use Data for 1998-2005 and Evaluation of Water-Use Scenarios

USGS Publications Warehouse

Gillip, Jonathan A.; Czarnecki, John B.

2009-01-01

A ground-water flow model of the Mississippi River Valley alluvial aquifer in eastern Arkansas, developed in 2003 to simulate the period of 1918-98, was validated with the addition of water-level and water-use data that extended the observation period to 2005. The original model (2003) was calibrated using water-level observations from 1972, 1982, 1992, and 1998, and water-use data through 1997. The original model subsequently was used to simulate water levels from 1999 to 2049 and showed that simulation of continued pumping at the 1997 water-use rate could not be sustained indefinitely without causing dry cells in the model. After publication of the original ground-water flow model, a total of 3,616 water-level observations from 698 locations measured during the period of 1998 to 2005 became available. Additionally, water-use data were compiled and used for the same period, totaling 290,005 discrete water-use values from 43,440 wells with as many as 39,169 wells pumping in any one year. Total pumping (which is primarily agricultural) for this 8-year period was about 2.3 trillion cubic feet of water and was distributed over approximately 10,340 square miles within the model area. An updated version of the original ground-water flow model was used to simulate the period of 1998-2005 with the additional water-level and water-use data. Water-level observations for 1998-2005 ranged from 74 to 293 feet above National Geodetic Vertical Datum of 1929 across the model area. The maximum water-level residual (observed minus simulated water-level values) for the 3,616 water-level observations was 52 feet, the minimum water-level residual was 60 feet, the average annual root mean squared error was 8.2 feet, and the annual average absolute residual was 6.0 feet. A correlation coefficient value of 0.96 was calculated for the line of best fit for observed to simulated water levels for the combined 1998-2005 dataset, indicating a good fit to the data and an acceptable validation

Monitoring Lake and Reservoir Level: Satellite Observations, Modeling and Prediction

NASA Astrophysics Data System (ADS)

Ricko, M.; Birkett, C. M.; Adler, R. F.; Carton, J.

2013-12-01

Satellite measurements of lake and reservoir water levels complement in situ observations by providing stage information for un-gauged basins and by filling data gaps in gauge records. However, different satellite radar altimeter-derived continental water level products may differ significantly owing to choice of satellites and data processing methods. To explore the impacts of these differences, a direct comparison between three different altimeter-based surface water level estimates (USDA/NASA GRLM, LEGOS and ESA-DMU) will be presented and products validated with lake level gauge time series for lakes and reservoirs of a variety of sizes and conditions. The availability of satellite-based rainfall (i.e., TRMM and GPCP) and satellite-based lake/reservoir levels offers exciting opportunities to estimate and monitor the hydrologic properties of the lake systems. Here, a simple water balance model is utilized to relate net freshwater flux on a catchment basin to lake/reservoir level. Focused on tropical lakes and reservoirs it allows a comparison of the flux to altimetric lake level estimates. The combined use of model, satellite-based rainfall, evaporation information and reanalysis products, can be used to output water-level hindcasts and seasonal future forecasts. Such a tool is fundamental for understanding present-day and future variations in lake/reservoir levels and enabling a better understand of climatic variations on inter-annual to inter-decadal time-scales. New model-derived water level estimates of lakes and reservoirs, on regional to global scales, would assist communities with interests in climate studies focusing on extreme events, such as floods and droughts, and be important for water resources management.

Effects of Irrigation, Drought, and Ground-Water Withdrawals on Ground-Water Levels in the Southern Lihue Basin, Kauai, Hawaii

USGS Publications Warehouse

Izuka, Scot K.

2006-01-01

A numerical ground-water-flow model was used to investigate the effects of irrigation on ground-water levels in the southern Lihue Basin, Kauai, Hawaii, and the relation between declining ground-water levels observed in the basin in the 1990s and early 2000s and concurrent drought, irrigation reduction, and changes in ground-water withdrawal. Results of steady-state model simulations indicate that changing from pre-development to 1981 irrigation and ground-water-withdrawal conditions could, given enough time for steady state to be achieved, raise ground-water levels in some areas of the southern Lihue Basin by as much as 200 feet, and that changing from 1981 to 1998 irrigation and ground-water-withdrawal conditions could lower ground-water levels in some areas by as much as 100 feet. Transient simulations combining drought, irrigation reduction, and changes in ground-water withdrawal show trends that correspond with those observed in measured water levels. Results of this study indicate that irrigation reduction was the primary cause of the observed decline in ground-water-levels. In contrast, ground-water withdrawal had a long-duration but small-magnitude effect, and drought had a widespread, high-magnitude but short-duration effect. Inasmuch as irrigation in the future is unlikely to return to the same levels as during the period of peak sugarcane agriculture, the decline in ground-water levels resulting from the reduction and ultimate end of sugarcane irrigation can be considered permanent. Assuming that irrigation does not return to the southern Lihue Basin and that, on average, normal rainfall persists and ground-water withdrawal remains at 1998 rates, model projections indicate that average ground-water levels in the Kilohana-Puhi area will continue to recover from the drought of 1998-2002 and eventually rise to within about 4 feet of the pre-drought conditions. Long-term climate trends, increases in ground-water withdrawal, or other factors not simulated in

Ground-Water Occurrence and Movement, 2006, and Water-Level Changes in the Detrital, Hualapai, and Sacramento Valley Basins, Mohave County, Arizona

USGS Publications Warehouse

Anning, David W.; Truini, Margot; Flynn, Marilyn E.; Remick, William H.

2007-01-01

Ground-water levels for water year 2006 and their change over time in Detrital, Hualapai, and Sacramento Valley Basins of northwestern Arizona were investigated to improve the understanding of current and past ground-water conditions in these basins. The potentiometric surface for ground water in the Basin-Fill aquifer of each basin is generally parallel to topography. Consequently, ground-water movement is generally from the mountain front toward the basin center and then along the basin axis toward the Colorado River or Lake Mead. Observed water levels in Detrital, Hualapai, and Sacramento Valley Basins have fluctuated during the period of historic water-level records (1943 through 2006). In Detrital Valley Basin, water levels in monitored areas have either remained the same, or have steadily increased as much as 3.5 feet since the 1980s. Similar steady conditions or water-level rises were observed for much of the northern and central parts of Hualapai Valley Basin. During the period of historic record, steady water-level declines as large as 60 feet were found in wells penetrating the Basin-Fill aquifer in areas near Kingman, northwest of Hackberry, and northeast of Dolan Springs within the Hualapai Valley Basin. Within the Sacramento Valley Basin, during the period of historic record, water-level declines as large as 55 feet were observed in wells penetrating the Basin-Fill aquifer in the Kingman and Golden Valley areas; whereas small, steady rises were observed in Yucca and in the Dutch Flat area.

Effect of citizen engagement levels in flood forecasting by assimilating crowdsourced observations in hydrological models

NASA Astrophysics Data System (ADS)

Mazzoleni, Maurizio; Cortes Arevalo, Juliette; Alfonso, Leonardo; Wehn, Uta; Norbiato, Daniele; Monego, Martina; Ferri, Michele; Solomatine, Dimitri

2017-04-01

In the past years, a number of methods have been proposed to reduce uncertainty in flood prediction by means of model updating techniques. Traditional physical observations are usually integrated into hydrological and hydraulic models to improve model performances and consequent flood predictions. Nowadays, low-cost sensors can be used for crowdsourced observations. Different type of social sensors can measure, in a more distributed way, physical variables such as precipitation and water level. However, these crowdsourced observations are not integrated into a real-time fashion into water-system models due to their varying accuracy and random spatial-temporal coverage. We assess the effect in model performance due to the assimilation of crowdsourced observations of water level. Our method consists in (1) implementing a Kalman filter into a cascade of hydrological and hydraulic models. (2) defining observation errors depending on the type of sensor either physical or social. Randomly distributed errors are based on accuracy ranges that slightly improve according to the citizens' expertise level. (3) Using a simplified social model to realistically represent citizen engagement levels based on population density and citizens' motivation scenarios. To test our method, we synthetically derive crowdsourced observations for different citizen engagement levels from a distributed network of physical and social sensors. The observations are assimilated during a particular flood event occurred in the Bacchiglione catchment, Italy. The results of this study demonstrate that sharing crowdsourced water level observations (often motivated by a feeling of belonging to a community of friends) can help in improving flood prediction. On the other hand, a growing participation of individual citizens or weather enthusiasts sharing hydrological observations in cities can help to improve model performance. This study is a first step to assess the effects of crowdsourced observations in

Analysis of water levels in the Frenchman Flat area, Nevada Test Site

USGS Publications Warehouse

Bright, D.J.; Watkins, S.A.; Lisle, B.A.

2001-01-01

Analysis of water levels in 21 wells in the Frenchman Flat area, Nevada Test Site, provides information on the accuracy of hydraulic-head calculations, temporal water-level trends, and potential causes of water-level fluctuations. Accurate hydraulic heads are particularly important in Frenchman Flat where the hydraulic gradients are relatively flat (less than 1 foot per mile) in the alluvial aquifer. Temporal water-level trends with magnitudes near or exceeding the regional hydraulic gradient may have a substantial effect on ground-water flow directions. Water-level measurements can be adjusted for the effects of barometric pressure, formation water density (from water-temperature measurements), borehole deviation, and land-surface altitude in selected wells in the Frenchman Flat area. Water levels in one well were adjusted for the effect of density; this adjustment was significantly greater (about 17 feet) than the adjustment of water levels for barometric pressure, borehole deviation, or land-surface altitude (less than about 4 feet). Water-level measurements from five wells exhibited trends that were statistically and hydrologically significant. Statistically significant water-level trends were observed for three wells completed in the alluvial aquifer (WW-5a, UE-5n, and PW-3), for one well completed in the carbonate aquifer (SM-23), and for one well completed in the quartzite confining unit (Army-6a). Potential causes of water-level fluctuations in wells in the Frenchman Flat area include changes in atmospheric conditions (precipitation and barometric pressure), Earth tides, seismic activity, past underground nuclear testing, and nearby pumping. Periodic water-level measurements in some wells completed in the carbonate aquifer indicate cyclic-type water-level fluctuations that generally correlate with longer term changes (more than 5 years) in precipitation. Ground-water pumping fromthe alluvial aquifer at well WW-5c and pumping and discharge from well RNM-2s

Louisiana wetland water level monitoring using retracked TOPEX/POSEIDON altimetry

USGS Publications Warehouse

Lee, H.; Shum, C.K.; Yi, Y.; Ibaraki, M.; Kim, J.-W.; Braun, Andreas; Kuo, C.-Y.; Lu, Z.

2009-01-01

Previous studies using satellite radar altimetry to observe inland river and wetland water level changes usually spatially average high-rate (10-Hz for TOPEX, 18-Hz for Envisat) measurements. Here we develop a technique to apply retracking of TOPEX waveforms by optimizing the estimated retracked gate positions using the Offset Center of Gravity retracker. This study, for the first time, utilizes stacking of retracked TOPEX data over Louisiana wetland and concludes that the water level observed by each of 10-Hz data with along-track sampling of ∼660 m exhibit variations, indicating detection of wetland dynamics. After further validations using nearby river gauges, we conclude that TOPEX is capable of measuring accurate water level changes beneath heavy-vegetation canopy region (swamp forest), and that it revealed wetland dynamic flow characteristics along track with spatial scale of 660 m or longer.

Water resources data, Montana, water year 2005: Volume 2. Yellowstone and upper Columbia River basins and ground-water levels

USGS Publications Warehouse

Berkas, Wayne R.; White, Melvin K.; Ladd, Patricia B.; Bailey, Fred A.; Dodge, Kent A.

2006-01-01

Water resources data for Montana for the 2005 water year, volumes 1 and 2, consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels in wells. This volume contains discharge records for 120 streamflow-gaging stations; stage or content records for 22 lakes and reservoirs; water-quality records for 86 streamflow stations (32 ungaged), and 25 ground-water wells; water-level records for 25 observation wells; and precipitation records for 2 atmospheric-deposition stations. Additional water year 2005 data collected at crest-stage gage and miscellaneous-measurement sites were collected but are not published in this report. These data are stored within the District office files in Helena and are available on request. These data represent part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Montana.

Earth Observations for Global Water Security

NASA Technical Reports Server (NTRS)

Lawford, Richard; Strauch, Adrian; Toll, David; Fekete, Balazs; Cripe, Douglas

2013-01-01

The combined effects of population growth, increasing demands for water to support agriculture, energy security, and industrial expansion, and the challenges of climate change give rise to an urgent need to carefully monitor and assess trends and variations in water resources. Doing so will ensure that sustainable access to adequate quantities of safe and useable water will serve as a foundation for water security. Both satellite and in situ observations combined with data assimilation and models are needed for effective, integrated monitoring of the water cycle's trends and variability in terms of both quantity and quality. On the basis of a review of existing observational systems, we argue that a new integrated monitoring capability for water security purposes is urgently needed. Furthermore, the components for this capability exist and could be integrated through the cooperation of national observational programmes. The Group on Earth Observations should play a central role in the design, implementation, management and analysis of this system and its products.

A Services-Oriented Architecture for Water Observations Data

NASA Astrophysics Data System (ADS)

Maidment, D. R.; Zaslavsky, I.; Valentine, D.; Tarboton, D. G.; Whitenack, T.; Whiteaker, T.; Hooper, R.; Kirschtel, D.

2009-04-01

Water observations data are time series of measurements made at point locations of water level, flow, and quality and corresponding data for climatic observations at point locations such as gaged precipitation and weather variables. A services-oriented architecture has been built for such information for the United States that has three components: hydrologic information servers, hydrologic information clients, and a centralized metadata cataloging system. These are connected using web services for observations data and metadata defined by an XML-based language called WaterML. A Hydrologic Information Server can be built by storing observations data in a relational database schema in the CUAHSI Observations Data Model, in which case, web services access to the data and metadata is automatically provided by query functions for WaterML that are wrapped around the relational database within a web server. A Hydrologic Information Server can also be constructed by custom-programming an interface to an existing water agency web site so that responds to the same queries by producing data in WaterML as do the CUAHSI Observations Data Model based servers. A Hydrologic Information Client is one which can interpret and ingest WaterML metadata and data. We have two client applications for Excel and ArcGIS and have shown how WaterML web services can be ingested into programming environments such as Matlab and Visual Basic. HIS Central, maintained at the San Diego Supercomputer Center is a repository of observational metadata for WaterML web services which presently indexes 342 million data measured at 1.75 million locations. This is the largest catalog water observational data for the United States presently in existence. As more observation networks join what we term "CUAHSI Water Data Federation", and the system accommodates a growing number of sites, measured parameters, applications, and users, rapid and reliable access to large heterogeneous hydrologic data repositories

Observing the Global Water Cycle from Space

NASA Technical Reports Server (NTRS)

Hildebrand, Peter H.; Houser, Paul; Schlosser, C. Adam

2003-01-01

This paper presents an approach to measuring all major components of the water cycle from space. The goal of the paper is to explore the concept of using a sensor-web of satellites to observe the global water cycle. The details of the required measurements and observation systems are therefore only an initial approach and will undergo future refinement, as their details will be highly important. Key elements include observation and evaluation of all components of the water cycle in terms of the storage of water-in the ocean, air, cloud and precipitation, in soil, ground water, snow and ice, and in lakes and rivers-and in terms of the global fluxes of water between these reservoirs. For each component of the water cycle that must be observed, the appropriate temporal and spatial scales of measurement are estimated, along with the some of the frequencies that have been used for active and passive microwave observations of the quantities. The suggested types of microwave observations are based on the heritage for such measurements, and some aspects of the recent heritage of these measurement algorithms are listed. The observational requirements are based on present observational systems, as modified by expectations for future needs. Approaches to the development of space systems for measuring the global water cycle can be based on these observational requirements.

Relative Sea Level, Tidal Range, and Extreme Water Levels in Boston Harbor from 1825 to 2016

NASA Astrophysics Data System (ADS)

Talke, S. A.; Kemp, A.; Woodruff, J. D.

2017-12-01

Long time series of water-level measurements made by tide gauges provide a rich and valuable observational history of relative sea-level change, the frequency and height of extreme water levels and evolving tidal regimes. However, relatively few locations have available tide-gauge records longer than 100 years and most of these places are in northern Europe. This spatio-temporal distribution hinders efforts to understand global-, regional- and local-scale trends. Using newly-discovered archival measurements, we constructed a 200 year, instrumental record of water levels, tides, and storm surges in Boston Harbor. We detail the recovery, datum reconstruction, digitization, quality assurance, and analysis of this extended observational record. Local, decadally-averaged relative sea-level rose by 0.28 ± 0.05 m since the 1820s, with an acceleration of 0.023 ±0.009 mm/yr2. Approximately 0.13 ± 0.02 m of the observed RSL rise occurred due to ongoing glacial isostatic adjustment, and the remainder occurred due to changes in ocean mass and volume associated with the onset of modern mean sea-level rise. Change-point analysis of the new relative sea level record confirms that anthropogenic rise began in 1924-1932, which is in agreement with global mean sea level estimates from the global tide gauge network. Tide range decreased by 5.5% between 1830 and 1910, likely due in large part to anthropogenic development. Storm tides in Boston Harbor are produced primarily by extratropical storms during the November-April time frame. The three largest storm tides occurred in 1851, 1909, and 1978. Because 90% of the top 20 storm tides since 1825 occurred during a spring tide, the secular change in tide range contributes to a slight reduction in storm tide magnitudes. However, non-stationarity in storm hazard was historically driven primarily by local relative sea-level rise; a modest 0.2 m increase in relative sea level reduces the 100 year high water mark to a once-in-10 year event.

Water resources data, Montana, water year 2005: Volume 2. Yellowstone and upper Columbia River basins and ground-water levels

USGS Publications Warehouse

Berkas, Wayne R.; White, Melvin K.; Ladd, Patricia B.; Bailey, Fred A.; Dodge, Kent A.

2005-01-01

Water resources data for Montana for the 2004 water year, volumes 1 and 2, consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels in wells. This volume contains discharge records for 119 streamflow-gaging stations; stage or content records for 21 lakes and reservoirs; and water-quality records for 69 streamflow stations (17 ungaged), and 3 lake sites; water-level records for 51 observation wells; and precipitation and water-quality records for 2 atmospheric-deposition stations. Additional water year 2004 data collected at crest-stage gage and miscellaneous-measurement sites were collected but are not published in this report. These data are stored within the District office files in Helena and are available on request. These data represent part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Montana.

Interpretation of changes in water level accompanying fault creep and implications for earthquake prediction.

USGS Publications Warehouse

Wesson, R.L.

1981-01-01

Quantitative calculations for the effect of a fault creep event on observations of changes in water level in wells provide an approach to the tectonic interpretation of these phenomena. For the pore pressure field associated with an idealized creep event having an exponential displacement versus time curve, an analytic expression has been obtained in terms of exponential-integral functions. The pore pressure versus time curves for observation points near the fault are pulselike; a sharp pressure increase (or decrease, depending on the direction of propagation) is followed by more gradual decay to the normal level after the creep event. The time function of the water level change may be obtained by applying the filter - derived by A.G.Johnson and others to determine the influence of atmospheric pressure on water level - to the analytic pore pressure versus time curves. The resulting water level curves show a fairly rapid increase (or decrease) and then a very gradual return to normal. The results of this analytic model do not reproduce the steplike changes in water level observed by Johnson and others. If the procedure used to obtain the water level from the pore pressure is correct, these results suggest that steplike changes in water level are not produced by smoothly propagating creep events but by creep events that propagate discontinuously, by changes in the bulk properties of the region around the well, or by some other mechanism.-Author

Separating decadal global water cycle variability from sea level rise.

PubMed

Hamlington, B D; Reager, J T; Lo, M-H; Karnauskas, K B; Leben, R R

2017-04-20

Under a warming climate, amplification of the water cycle and changes in precipitation patterns over land are expected to occur, subsequently impacting the terrestrial water balance. On global scales, such changes in terrestrial water storage (TWS) will be reflected in the water contained in the ocean and can manifest as global sea level variations. Naturally occurring climate-driven TWS variability can temporarily obscure the long-term trend in sea level rise, in addition to modulating the impacts of sea level rise through natural periodic undulation in regional and global sea level. The internal variability of the global water cycle, therefore, confounds both the detection and attribution of sea level rise. Here, we use a suite of observations to quantify and map the contribution of TWS variability to sea level variability on decadal timescales. In particular, we find that decadal sea level variability centered in the Pacific Ocean is closely tied to low frequency variability of TWS in key areas across the globe. The unambiguous identification and clean separation of this component of variability is the missing step in uncovering the anthropogenic trend in sea level and understanding the potential for low-frequency modulation of future TWS impacts including flooding and drought.

Water Cycle Extremes: from Observations to Decisions

NASA Astrophysics Data System (ADS)

Lawford, R. G.; Unninayar, S.; Berod, D.

2015-12-01

Extremes in the water cycle (droughts and floods) pose major challenges for water resource managers and emergency services. These challenges arise from observational and prediction systems, advisory services, impact reduction strategies, and cleanup and recovery operations. The Group on Earth Observations (GEO) through its Water Strategy ("GEOSS Water Strategy: from observations to decisions") is seeking to provide systems that will enable its members to more effectively meet their information needs prior to and during an extreme event. This presentation reviews the wide range of impacts that arise from extremes in the water cycle and the types of data and information needed to plan for and respond to these extreme events. It identifies the capabilities and limitations of current observational and analysis systems in defining the scale, timing, intensity and impacts of water cycle extremes and in directing society's response to them. This summary represents an early preliminary assessment of the global and regional information needs of water resource managers and begins to outline a strategy within GEO for using Earth Observations and ancillary information to address these needs.

Diffuse radiation increases global ecosystem-level water-use efficiency

NASA Astrophysics Data System (ADS)

Moffat, A. M.; Reichstein, M.; Cescatti, A.; Knohl, A.; Zaehle, S.

2012-12-01

Current environmental changes lead not only to rising atmospheric CO2 levels and air temperature but also to changes in air pollution and thus the light quality of the solar radiation reaching the land-surface. While rising CO2 levels are thought to enhance photosynthesis and closure of stomata, thus leading to relative water savings, the effect of diffuse radiation on transpiration by plants is less clear. It has been speculated that the stimulation of photosynthesis by increased levels of diffuse light may be counteracted by higher transpiration and consequently water depletion and drought stress. Ultimately, in water co-limited systems, the overall effect of diffuse radiation will depend on the sensitivity of canopy transpiration versus photosynthesis to diffuse light, i.e. whether water-use efficiency changes with relative levels of diffuse light. Our study shows that water-use efficiency increases significantly with higher fractions of diffuse light. It uses the ecosystem-atmosphere gas-exchange observations obtained with the eddy covariance method at 29 flux tower sites. In contrast to previous global studies, the analysis is based directly on measurements of diffuse radiation. Its effect on water-use efficiency was derived by analyzing the multivariate response of carbon and water fluxes to radiation and air humidity using a purely empirical approach based on artificial neural networks. We infer that per unit change of diffuse fraction the water-use efficiency increases up to 40% depending on diffuse fraction levels and ecosystem type. Hence, in regions with increasing diffuse radiation positive effects on primary production are expected even under conditions where water is co-limiting productivity.

Influence of Reservoir Water Level Fluctuations on Sediment ...

EPA Pesticide Factsheets

Mercury (Hg) is a pollutant of global concern due to its ability to accumulate as methylmercury (MeHg) in biota. Mercury is methylated by anaerobic microorganisms such as sulfate reducing bacteria (SRB) in water and sediment. Throughout North America, reservoirs tend to have elevated methylmercury (MeHg) concentrations compared to natural lakes and rivers. This impact is most pronounced in newly created reservoirs where methylation is fueled by the decomposition of flooded organic material, which can release Hg and enhance microbial activity. Much less is known about the longer-term water-level management impacts on Hg cycling in older reservoirs. The objective of our study was to understand the role of on-going water-level fluctuations on sediment MeHg concentrations and sulfur speciation within a reservoir 75 years after initial impoundment. The study was performed at the Cottage Grove Reservoir located 15 km downstream of the historical Black Butte Hg mine. For 8 months each year, the water level is lowered resulting in roughly half of the reservoir’s sediment being exposed to the atmosphere. Water samples from the inflow, water-column, outflow, and sediment were collected seasonally over a year for total-Hg, MeHg, and several ancillary parameters. The results showed that conditions in the reservoir were favorable to methylation with a much higher %MeHg observed in the outflowing water (34%) compared to the inflow (7%) during the late-summer. An

Precursory changes in well water level prior to the March, 2000 eruption of Usu Volcano, Japan

NASA Astrophysics Data System (ADS)

Shibata, Tomo; Akita, Fujio

The height of water levels in two wells located near Usu volcano, Japan, changed in a systematic fashion for several months prior to the eruption of Usu volcano on 31 March 2000. In one well, water-level decrease relative to normal levels was first observed at the beginning of October 1999. The decreasing water-level is postulated to result from groundwater flow into cracks widened by intruding magma during dike formation. From the beginning of January 2000, the rate of decrease became higher. During this time, the water level of the second well increased by 0.05 m and then gradually decreased. The water-level changes are consistent with volumetric expansion of magma inside the magma chamber, followed by intrusion of magma into the fracture system associated with widening of cracks. We conclude that water-level observations can provide information that may potentially be used to predict further volcanic eruptions.

Observing the Global Water Cycle from Space

NASA Technical Reports Server (NTRS)

Hildebrand, P. H.

2004-01-01

This paper presents an approach to measuring all major components of the water cycle from space. Key elements of the global water cycle are discussed in terms of the storage of water-in the ocean, air, cloud and precipitation, in soil, ground water, snow and ice, and in lakes and rivers, and in terms of the global fluxes of water between these reservoirs. Approaches to measuring or otherwise evaluating the global water cycle are presented, and the limitations on known accuracy for many components of the water cycle are discussed, as are the characteristic spatial and temporal scales of the different water cycle components. Using these observational requirements for a global water cycle observing system, an approach to measuring the global water cycle from space is developed. The capabilities of various active and passive microwave instruments are discussed, as is the potential of supporting measurements from other sources. Examples of space observational systems, including TRMM/GPM precipitation measurement, cloud radars, soil moisture, sea surface salinity, temperature and humidity profiling, other measurement approaches and assimilation of the microwave and other data into interpretative computer models are discussed to develop the observational possibilities. The selection of orbits is then addressed, for orbit selection and antenna size/beamwidth considerations determine the sampling characteristics for satellite measurement systems. These considerations dictate a particular set of measurement possibilities, which are then matched to the observational sampling requirements based on the science. The results define a network of satellite instrumentation systems, many in low Earth orbit, a few in geostationary orbit, and all tied together through a sampling network that feeds the observations into a data-assimilative computer model.

Records of water-level measurements in wells in the Oklahoma panhandle, 1971-72

USGS Publications Warehouse

Hart, Donald L.; Hoffman, George L.; Goemaat, Robert L.

1972-01-01

Investigations of the ground-water resources of the Oklahoma panhandle by the U.S. Geological Survey in cooperation with the Oklahoma Water Resources Board includes collection of water-level records; the systematic collection of these records began in 1937. Records of many shallow wells were compiled in 1937 and periodic measurements were made in a few wells until 1966. Owing to the heavy development of irrigation during the 1960's (fig. 1) an expanded network of observation wells established in Texas County in 1966 and in Beaver and Cimarron Counties in 1967; measurement of water levels have been made on an annual basis since those times.This report contains water-level records for the period 1971-72 and the water-level change for the period 1966-72 in Texas County, and for the period 1967-72 in Beaver and Cimarron Counties. At the present time (1972) the annual observation-well network includes 521 wells, of which 97 are in Beaver County, 203 are in Cimarron County, and 221 are in Texas County. These data provide an index to available ground-water supplies; they will be useful in planning and studying water resources development; and they will serve as a framework of data for the detailed hydrologic investigation now in progress in the panhandle.

Lidar observations of low-level wind reversals over the Gulf of Lion and characterization of their impact on the water vapour variability

NASA Astrophysics Data System (ADS)

Di Girolamo, Paolo; Flamant, Cyrille; Cacciani, Marco; Summa, Donato; Stelitano, Dario; Richard, Evelyne; Ducrocq, Véronique; Fourrie, Nadia; Said, Frédérique

2017-02-01

Water vapour measurements from a ground-based Raman lidar and an airborne differential absorption lidar, complemented by high resolution numerical simulations from two mesoscale models (Arome-WMED and MESO-NH), are considered to investigate transition events from Mistral/Tramontane to southerly marine flow taking place over the Gulf of Lion in Southern France in the time frame September-October 2012, during the Hydrological Cycle in the Mediterranean Experiment (HyMeX) Special Observation Period 1 (SOP1). Low-level wind reversals associated with these transitions are found to have a strong impact on water vapour transport, leading to a large variability of the water vapour vertical and horizontal distribution. The high spatial and temporal resolution of the lidar data allow to monitor the time evolution of the three-dimensional water vapour field during these transitions from predominantly northerly Mistral/Tramontane flow to a predominantly southerly flow, allowing to identify the quite sharp separation between these flows, which is also quite well captured by the mesoscale models.

An Alternative Approach of Coastal Sea-Level Observation from Remote Sensing Imageries

NASA Astrophysics Data System (ADS)

Peng, H. Y.; Tseng, K. H.; Chung-Yen, K.; Lin, T. H.; Liao, W. H.; Chen, C. F.

2017-12-01

Coastal sea level can be observed as waterline changes along a coastal digital elevation model (DEM). However, most global DEMs, such as the Shuttle Radar Topography Mission (SRTM) DEM with 30 m resolution, provide limited coverage over coastal area due to the impermeability of radar signal over water and the lack of low-tide coincidence. Therefore, we aim to extend to coverage of SRTM DEM for the determination of intertidal zone and to monitor sea-level changes along the entire coastline of Taiwan (>1200km). We firstly collect historical cloud-free images since the 1980s, including Landsat series, SPOT series and Sentinel-2, and then calculate the Modified Normalized Difference Water Index (MNDWI) to identify water pixels. After computing water appearance probability of each pixel, it is converted into actual elevation by introducing the DTU10 tide model for high tide and low tide boundaries. A coastal DEM of intertidal zone is reconstructed and the accuracy is at 50 cm level as compared with in situ DEM built by an unmanned aerial vehicle (UAV). Finally, we use this product to define the up-to-date intertidal zone and estimate sea-level changes by using remote sensing snapshots.

Montana Water Resources Data - 2003, Volume 2. Yellowstone and Upper Columbia River Basins and Ground-Water Levels

USGS Publications Warehouse

Berkas, Wayne R.; White, Melvin K.; Ladd, Patricia B.; Bailey, Fred A.; Dodge, Kent A.

2004-01-01

Water resources data for Montana for the 2003 water year, volumes 1 and 2, consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels in wells. This volume contains discharge records for 114 streamflow-gaging stations; stage or content records for 4 lakes and large reservoirs and content for 26 smaller reservoirs; water-quality records for 76 streamflow stations (11 ungaged), and 3 lakes; water-level records for 53 observation wells; and precipitation and water-quality records for 2 atmospheric-deposition stations. Additional water year 2003 data collected at crest-stage gage and miscellaneous-measurement sites were collected but are not published in this report. These data are stored within the District office files in Helena and are available on request. These data represent part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Montana.

Transient response of Salix cuttings to changing water level regimes

NASA Astrophysics Data System (ADS)

Gorla, L.; Signarbieux, C.; Turberg, P.; Buttler, A.; Perona, P.

2015-03-01

Sustainable water management requires an understanding of the effects of flow regulation on riparian ecomorphological processes. We investigated the transient response of Salix viminalis by examining the effect of water-level regimes on its above-ground and below-ground biomass. Four sets of Salix cuttings, three juveniles (in the first growing season) and one mature (1 year old), were planted and initially grown under the same water-level regime for 1 month. We imposed three different water-level regime treatments representing natural variability, a seasonal trend with no peaks, and minimal flow (characteristic of hydropower) consisting of a constant water level and natural flood peaks. We measured sap flux, stem water potential, photosynthesis, growth parameters, and final root architecture. The mature cuttings were not affected by water table dynamics, but the juveniles displayed causal relationships between the changing water regime, plant growth, and root distribution during a 2 month transient period. For example, a 50% drop in mean sap flux corresponded with a -1.5 Mpa decrease in leaf water potential during the first day after the water regime was changed. In agreement with published field observations, the cuttings concentrated their roots close to the mean water table of the corresponding treatment, allowing survival under altered conditions and resilience to successive stress events. Juvenile development was strongly impacted by the minimum flow regime, leading to more than 60% reduction of both above-ground and below-ground biomass, with respect to the other treatments. Hence, we suggest avoiding minimum flow regimes where Salix restoration is prioritized.

Detecting drawdowns masked by environmental stresses with water-level models

USGS Publications Warehouse

Garcia, C.A.; Halford, K.J.; Fenelon, J.M.

2013-01-01

Detecting and quantifying small drawdown at observation wells distant from the pumping well greatly expands the characterized aquifer volume. However, this detection is often obscured by water level fluctuations such as barometric and tidal effects. A reliable analytical approach for distinguishing drawdown from nonpumping water-level fluctuations is presented and tested here. Drawdown is distinguished by analytically simulating all pumping and nonpumping water-level stresses simultaneously during the period of record. Pumping signals are generated with Theis models, where the pumping schedule is translated into water-level change with the Theis solution. This approach closely matched drawdowns simulated with a complex three-dimensional, hypothetical model and reasonably estimated drawdowns from an aquifer test conducted in a complex hydrogeologic system. Pumping-induced changes generated with a numerical model and analytical Theis model agreed (RMS as low as 0.007 m) in cases where pumping signals traveled more than 1 km across confining units and fault structures. Maximum drawdowns of about 0.05 m were analytically estimated from field investigations where environmental fluctuations approached 0.2 m during the analysis period.

Water-level monitoring in the area of the Palmdale Uplift, Southern California

USGS Publications Warehouse

Lamar, D.L.; Merifield, P.M.

1978-01-01

Abnormal behavior of water levels in wells has been observed prior to a number of earthquakes. For instance, water-level minima have been noted in the Cienega Winery well before earthquakes on the San Andreas fault. Abnormal water-level fluctuations were used in conjunctions with other precursors to predict the February 4, 1975, Haicheng earthquake in northeastern China. That such changes should occur prior to earthquakes is not surprising. Ground water that occupies the void spaces in porous rocks or alluvium can be expected to rise in wells when an aquifer is squeezed and fall when it is distended. COnfined aquifers, in particualr, have been found to be highly sensitive to Earth strain changes. 

Coseismic Deformations Associated with the M=7.2, April 04, 2010, El Mayor-Cucapah Earthquake, Observed from Leveling Survey, Geotechnical Instruments and Water Level Changes in the Mexicali Valley

NASA Astrophysics Data System (ADS)

Glowacka, E.; Robles, B.; Vázquez, R.; Sarychikhina, O.; Suárez-Vidal, F.; Ramirez, J.; Nava Pichardo, F. A.; Farfan, F.; Diaz de Cossio, G.

2010-12-01

A first order, second class leveling survey in the Mexicali Valley had been just finished in February 2010, for a project carried out by CICESE (Center for Scientific Research and Higher Education of Ensenada), IMTA (Mexican Institute of Water Technology) and CONAGUA (National Water Comission). Immediately after the M=7.2 earthquake the survey was repeated along 240 km of the profiles in the area of the Cerro Prieto pull-apart basin. The leveling started at the LN00 GPS monument in La Puerta. Overall, an uplift of about 30 cm towards the NE, along the 38 km line, in direction SW-NE is observed with larger gradient to the South of the area. Three subsidence bowls differ from this general pattern. One, south from Ejido Saltillo, with the relative subsidence of 19 cm (considering the displacement at LN00 as zero subsidence), probably reflects subsidence of the Saltillo-Guerrero graben; the second, with a subsidence of 23 cm, is situated south from Ejido Nuevo Leon and can be related to the subsidence triggered by the earthquake in the production area of Cerro Prieto IV. For the third one, with relative depth of 36 cm, situated close to Zacamoto, the southeastern limit cannot be determined, so only a comparison with other methods can explain the origin of this anomaly. All the subsidence bowls are associated with liquefaction observed in the area, with more liquefaction observed close to Zacamoto. Since 1996, CICESE has been operating a network of geotechnical instruments (REDECVAM) for continuous recording of deformation related to tectonic (seismic and interseismic) phenomena, as well as anthropogenic deformation caused by the deep fluid extraction at the Cerro Prieto Geothermal Field. The instruments are installed along the faults which limit the Cerro Prieto pull-apart basin at a distance from 8 to 15 km from the epicenter. Coseismic step-like groundwater level changes ranging from 0.4 to 5.0 meters were recorded at 4 wells in the Cerro Prieto Pull apart

How Historical Information Can Improve Extreme Value Analysis of Coastal Water Levels

NASA Astrophysics Data System (ADS)

Le Cozannet, G.; Bulteau, T.; Idier, D.; Lambert, J.; Garcin, M.

2016-12-01

The knowledge of extreme coastal water levels is useful for coastal flooding studies or the design of coastal defences. While deriving such extremes with standard analyses using tide gauge measurements, one often needs to deal with limited effective duration of observation which can result in large statistical uncertainties. This is even truer when one faces outliers, those particularly extreme values distant from the others. In a recent work (Bulteau et al., 2015), we investigated how historical information of past events reported in archives can reduce statistical uncertainties and relativize such outlying observations. We adapted a Bayesian Markov Chain Monte Carlo method, initially developed in the hydrology field (Reis and Stedinger, 2005), to the specific case of coastal water levels. We applied this method to the site of La Rochelle (France), where the storm Xynthia in 2010 generated a water level considered so far as an outlier. Based on 30 years of tide gauge measurements and 8 historical events since 1890, the results showed a significant decrease in statistical uncertainties on return levels when historical information is used. Also, Xynthia's water level no longer appeared as an outlier and we could have reasonably predicted the annual exceedance probability of that level beforehand (predictive probability for 2010 based on data until the end of 2009 of the same order of magnitude as the standard estimative probability using data until the end of 2010). Such results illustrate the usefulness of historical information in extreme value analyses of coastal water levels, as well as the relevance of the proposed method to integrate heterogeneous data in such analyses.

Laboratory meter-scale seismic monitoring of varying water levels in granular media

NASA Astrophysics Data System (ADS)

Pasquet, S.; Bodet, L.; Bergamo, P.; Guérin, R.; Martin, R.; Mourgues, R.; Tournat, V.

2016-12-01

Laboratory physical modelling and non-contacting ultrasonic techniques are frequently proposed to tackle theoretical and methodological issues related to geophysical prospecting. Following recent developments illustrating the ability of seismic methods to image spatial and/or temporal variations of water content in the vadose zone, we developed laboratory experiments aimed at testing the sensitivity of seismic measurements (i.e., pressure-wave travel times and surface-wave phase velocities) to water saturation variations. Ultrasonic techniques were used to simulate typical seismic acquisitions on small-scale controlled granular media presenting different water levels. Travel times and phase velocity measurements obtained at the dry state were validated with both theoretical models and numerical simulations and serve as reference datasets. The increasing water level clearly affects the recorded wave field in both its phase and amplitude, but the collected data cannot yet be inverted in the absence of a comprehensive theoretical model for such partially saturated and unconsolidated granular media. The differences in travel time and phase velocity observed between the dry and wet models show patterns that are interestingly coincident with the observed water level and depth of the capillary fringe, thus offering attractive perspectives for studying soil water content variations in the field.

Observation of Mountain Lee Waves with MODIS NIR Column Water Vapor

NASA Technical Reports Server (NTRS)

Lyapustin, A.; Alexander, M. J.; Ott, L.; Molod, A.; Holben, B.; Susskind, J.; Wang, Y.

2014-01-01

Mountain lee waves have been previously observed in data from the Moderate Resolution Imaging Spectroradiometer (MODIS) "water vapor" 6.7 micrometers channel which has a typical peak sensitivity at 550 hPa in the free troposphere. This paper reports the first observation of mountain waves generated by the Appalachian Mountains in the MODIS total column water vapor (CWV) product derived from near-infrared (NIR) (0.94 micrometers) measurements, which indicate perturbations very close to the surface. The CWV waves are usually observed during spring and late fall or some summer days with low to moderate CWV (below is approx. 2 cm). The observed lee waves display wavelengths from3-4 to 15kmwith an amplitude of variation often comparable to is approx. 50-70% of the total CWV. Since the bulk of atmospheric water vapor is confined to the boundary layer, this indicates that the impact of thesewaves extends deep into the boundary layer, and these may be the lowest level signatures of mountain lee waves presently detected by remote sensing over the land.

A comparison of observed extreme water levels at the German Bight elaborated through an extreme value analysis (EVA) with extremes derived from a regionally coupled ocean-atmospheric climate model (MPI-OM)

NASA Astrophysics Data System (ADS)

Möller, Jens; Heinrich, Hartmut

2017-04-01

As a consequence of climate change atmospheric and oceanographic extremes and their potential impacts on coastal regions are of growing concern for governmental authorities responsible for the transportation infrastructure. Highest risks for shipping as well as for rail and road traffic originate from combined effects of extremes of storm surges and heavy rainfall which sometimes lead to insufficient dewatering of inland waterways. The German Ministry of Transport and digital Infrastructure therefore has tasked its Network of Experts to investigate the possible evolutions of extreme threats for low lands and especially for Kiel Canal, which is an important shortcut for shipping between the North and Baltic Seas. In this study we present results of a comparison of an Extreme Value Analysis (EVA) carried out on gauge observations and values derived from a coupled Regional Ocean-Atmosphere Climate Model (MPI-OM). High water levels at the coasts of the North and Baltic Seas are one of the most important hazards which increase the risk of flooding of the low-lying land and prevents such areas from an adequate dewatering. In this study changes in the intensity (magnitude of the extremes) and duration of extreme water levels (above a selected threshold) are investigated for several gauge stations with data partly reaching back to 1843. Different methods are used for the extreme value statistics, (1) a stationary general Pareto distribution (GPD) model as well as (2) an instationary statistical model for better reproduction of the impact of climate change. Most gauge stations show an increase of the mean water level of about 1-2 mm/year, with a stronger increase of the highest water levels and a decrease (or lower increase) of the lowest water levels. Also, the duration of possible dewatering time intervals for the Kiel-Canal was analysed. The results for the historical gauge station observations are compared to the statistics of modelled water levels from the coupled

Water level response in back-barrier bays unchanged following Hurricane Sandy

USGS Publications Warehouse

Aretxabaleta, Alfredo L.; Butman, Bradford; Ganju, Neil K.

2014-01-01

On 28–30 October 2012, Hurricane Sandy caused severe flooding along portions of the northeast coast of the United States and cut new inlets across barrier islands in New Jersey and New York. About 30% of the 20 highest daily maximum water levels observed between 2007 and 2013 in Barnegat and Great South Bay occurred in 5 months following Hurricane Sandy. Hurricane Sandy provided a rare opportunity to determine whether extreme events alter systems protected by barrier islands, leaving the mainland more vulnerable to flooding. Comparisons between water levels before and after Hurricane Sandy at bay stations and an offshore station show no significant differences in the transfer of sea level fluctuations from offshore to either bay following Sandy. The post-Hurricane Sandy bay high water levels reflected offshore sea levels caused by winter storms, not by barrier island breaching or geomorphic changes within the bays.

Vertical Gravimeter Array Observations and Their Performance in Groundwater-Level Monitoring

NASA Astrophysics Data System (ADS)

Tanaka, T.; Honda, R.

2018-03-01

The gravitational effects of the atmosphere and subsurface water are significant obstacles to observing gravity variations on the sub-μGal (1 μGal = 10 nm/s2) scale. The goal of this study is to detect changes in gravity that are caused by mass redistributions deep underground related to seismological phenomena by reducing environmental gravity effects using multiple gravimeters belowground and aboveground, which we term a "vertical gravimeter array." Based on an evaluation of the responses to atmospheric effects and rainfall events identified in observations made with individual relative gravimeters, the vertical gravimeter array succeeds in stacking the target signals from deep underground and in reducing errors due to rainfall or free groundwater and atmospheric effects. To enable accurate interpretation, we introduce a physical approach that is based on attraction and loading deformation effects for atmospheric reduction using state-of-the-art gridded weather data products. Changes in the water levels of confined groundwater can be regarded as a signal from deep underground, and a response coefficient of approximately -15 μGal/m was obtained. In addition, the response coefficient of the free groundwater level was determined to be approximately 5 μGal/m. Such array observations are expected to contribute to monitoring crustal activity and hydrological studies.

Simulated effects of water-level changes in the Mississippi River and Pokegama Reservoir on ground-water levels, Grand Rapids area, Minnesota

USGS Publications Warehouse

Jones, Perry M.

2005-01-01

The extent of aquifer water-level changes resulting from these river, wetland, and lake water-level changes varied because of the complex hydrogeology of the study area. A 1.00-foot decline in reservoir/river water levels caused a maximum simulated ground-water-level decline in the middle aquifer near Jay Gould and Little Jay Gould Lakes of 1.09 feet and a maximum simulated ground-water-level decline of 1.00 foot in the lower aquifer near Cut-off and Blackwater Lakes. The amount and extent of ground-water-level changes in the middle and lower aquifers can be explained by the thickness, extent, and connectivity of the aquifers. Surface-water/ground-water interactions near wetlands and lakes with water levels unchanged from the calibrated model resulted in small water-table altitude differences among the simulations. Results of the ground-water modeling indicate that lowering of the reservoir and river water levels by 1.00 foot likely will not substantially affect water levels in the middle and lower aquifers.

Ensemble-based evaluation of extreme water levels for the eastern Baltic Sea

NASA Astrophysics Data System (ADS)

Eelsalu, Maris; Soomere, Tarmo

2016-04-01

extreme water levels and their return periods with similar estimates derived from local observations reveals an interesting pattern of match and mismatch. The match is almost perfect in measurement sites where local effects (e.g., wave-induced set-up or local surge in very shallow areas that are not resolved by circulation models) do not contribute to the observed values of water level. There is, however, substantial mismatch between projected and observed extreme values for most of the Estonian coast. The mismatch is largest for sections that are open to high waves and for several bays that are deeply cut into mainland but open for predominant strong wind directions. Detailed quantification of this mismatch eventually makes it possible to develop substantially improved estimates of extreme water levels in sections where local effects considerably contribute into the total water level.

Miniaturized Water Flow and Level Monitoring System for Flood Disaster Early Warning

NASA Astrophysics Data System (ADS)

Ifedapo Abdullahi, Salami; Hadi Habaebi, Mohamed; Surya Gunawan, Teddy; Rafiqul Islam, MD

2017-11-01

This study presents the performance of a prototype miniaturised water flow and water level monitoring sensor designed towards supporting flood disaster early warning systems. The design involved selection of sensors, coding to control the system mechanism, and automatic data logging and storage. During the design phase, the apparatus was constructed where all the components were assembled using locally sourced items. Subsequently, under controlled laboratory environment, the system was tested by running water through the inlet during which the flow rate and rising water levels are automatically recorded and stored in a database via Microsoft Excel using Coolterm software. The system is simulated such that the water level readings measured in centimeters is output in meters using a multiplicative of 10. A total number of 80 readings were analyzed to evaluate the performance of the system. The result shows that the system is sensitive to water level rise and yielded accurate measurement of water level. But, the flow rate fluctuates due to the manual water supply that produced inconsistent flow. It was also observed that the flow sensor has a duty cycle of 50% of operating time under normal condition which implies that the performance of the flow sensor is optimal.

Records of water-level measurements in wells in the Oklahoma panhandle, 1966-70

USGS Publications Warehouse

Hart, Donald L.

1972-01-01

Investigations of the ground-water resources of the Oklahoma panhandle by the U.S. Geological Survey in cooperation with the Oklahoma Water Resources Board includes collection of water-level records; the systematic collection of these records began in 1937. Records of many shallow wells were compiled in 1937 and periodic measurements were made in a few wells until 1966. Owing to the heavy development of irrigation during the 1960's (fig. 1) an expanded network of observation wells established in Texas County in 1966 and in Beaver and Cimarron Counties in 1967; measurement of water levels have been made on an annual basis since those times. This report contains water-level records for the period 1966-70 in Texas County, and for the period 1967-70 in Beaver and Cimarron Counties. At the present time (1971) the annual observation-well network includes 528 wells, of which 98 are in Beaver County, 211 are in Cimarron County, and 219 are in Texas County. These data provide an index to available ground-water supplies; they will be useful in planning and studying water resources development; and they will serve as a framework of data for the detailed hydrologic investigation now in progress in the panhandle. (available as photostat copy only)

Negotiating water across levels: A peace and conflict "Toolbox" for water diplomacy

NASA Astrophysics Data System (ADS)

Grech-Madin, Charlotte; Döring, Stefan; Kim, Kyungmee; Swain, Ashok

2018-04-01

As a key policy tool, water diplomacy offers greater political engagement in the cooperative management of shared water. A range of initiatives has been dedicated to this end, almost invariably oriented around the interactions of nation states. Crucially, however, practitioners of water diplomacy also need to address water governance at sub-state levels. As a political, multi-level, and normative field, peace and conflict research offers a pluralism of approaches designed to bring actors together at all levels. Drawing upon this research, this paper offers new focal points for water diplomacy that can enhance its policy effectiveness and enrich its underlying academic current. More specifically, it presents three hitherto undervalued tools for water diplomacy: at the interstate level, to uncover the rich body of political norms that bind states to shared understandings of acceptable practice around water. At the intrastate level, to incorporate ethnography of water users and civil society groups' responses to state-led waterworks projects, and at the communal level to employ disaggregated georeferenced data on water resources in conflict-prone areas. Taken together, these analytical tools provide a multi-faceted political gauge of the dynamics of water diplomacy, and add vital impetus to develop water diplomacy across multiple levels of policy engagement.

Projections of extreme water level events for atolls in the western Tropical Pacific

NASA Astrophysics Data System (ADS)

Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

2014-12-01

Conditions that lead to extreme water levels and coastal flooding are examined for atolls in the Republic of the Marshall Islands based on a recent field study of wave transformations over fringing reefs, tide gauge observations, and wave model hindcasts. Wave-driven water level extremes pose the largest threat to atoll shorelines, with coastal levels scaling as approximately one-third of the incident breaking wave height. The wave-driven coastal water level is partitioned into a mean setup, low frequency oscillations associated with cross-reef quasi-standing modes, and wind waves that reach the shore after undergoing high dissipation due to breaking and bottom friction. All three components depend on the water level over the reef; however, the sum of the components is independent of water level due to cancelling effects. Wave hindcasts suggest that wave-driven water level extremes capable of coastal flooding are infrequent events that require a peak wave event to coincide with mid- to high-tide conditions. Interannual and decadal variations in sea level do not change the frequency of these events appreciably. Future sea-level rise scenarios significantly increase the flooding threat associated with wave events, with a nearly exponential increase in flooding days per year as sea level exceeds 0.3 to 1.0 m above current levels.

Effects of Withdrawals on Ground-Water Levels in Southern Maryland and the Adjacent Eastern Shore, 1980-2005

USGS Publications Warehouse

Soeder, Daniel J.; Raffensperger, Jeff P.; Nardi, Mark R.

2007-01-01

Ground water is the primary source of water supply in most areas of Maryland?s Atlantic Coastal Plain, including Southern Maryland. The counties in this area are experiencing some of the most rapid growth and development in the State, resulting in an increased demand for ground-water production. The cooperative, basic water-data program of the U.S. Geological Survey and the Maryland Geological Survey has collected long-term observations of ground-water levels in Southern Maryland and parts of the Eastern Shore for many decades. Additional water-level observations were made by both agencies beginning in the 1970s, under the Power Plant Research Program of the Maryland Department of Natural Resources. These long-term water levels commonly show significant declines over several decades, which are attributed to ground-water withdrawals. Ground-water-level trends since 1980 in major Coastal Plain aquifers such as the Piney Point-Nanjemoy, Aquia, Magothy, upper Patapsco, lower Patapsco, and Patuxent were compared to water use and withdrawal data. Potentiometric surface maps show that most of the declines in ground-water levels can be directly related to effects from major pumping centers. There is also evidence that deep drawdowns in some pumped aquifers may be causing declines in adjacent, unpumped aquifers. Water-level hydrographs of many wells in Southern Maryland show linear declines in levels year after year, instead of the gradual leveling-off that would be expected as the aquifers equilibrate with pumping. A continual increase in the volumes of water being withdrawn from the aquifers is one explanation for why they are not reaching equilibrium. Although reported ground-water production in Southern Maryland has increased somewhat over the past several decades, the reported increases are often not large enough to account for the observed water-level declines. Numerical modeling simulations indicate that a steady, annual increase in the number of small wells could

Water Levels In Major Artesian Aquifers Of The New Jersey Coastal Plain, 1988

USGS Publications Warehouse

Rosman, Robert; Lacombe, Pierre J.; Storck, Donald A.

1995-01-01

Water levels in 1,251 wells in the New Jersey Coastal Plain, Philadelphia County, Pennsylvania, and Kent and New Castle Counties, Delaware, were measured from October 1988 to February 1989 and compared with 1,071 water levels measured from September 1983 to May 1984. Water levels in 916 of the wells measured in the 1983 study were remeasured in the 1988 study. Alternate wells were selected to replace wells used in 1983 that were inaccessible at the time of the water-level measurements in 1988 or had been destroyed. New well sites were added in strategic locations to increase coverage where possible. Large cones of depression have formed or expanded in the nine major artesian aquifers that underlie the New Jersey Coastal Plain. Water levels are shown on nine potentiometric-surface maps. Hydrographs for observation wells typically show water-level declines for 1983, through 1989. In the confined Cohansey aquifer, the lowest water level, 20 feet below sea level, was measured in a well located at Cape May City Water Department, Cape May County. Water levels in the Atlantic City 800-foot sand declined as much as 21 feet at Ventnor, Atlantic County, over the 6-year period from the 1983 study to this study for 1988. Water levels in the Piney Point aquifer were as low as 56 feet below sea level at Seaside Park, Ocean County; 45 feet below sea level in southern Cumberland County; and 28 feet below sea level at Margate, Atlantic County. Water levels in the Vincentown aquifer did not change over the 6-year period. The lowest water levels in the Wenonah-Mount Laurel aquifer and the Englishtown aquifer system were 218 feet and 256 feet below sea level, respectively. Large cones of depression in the Potomac- Raritan-Magothy aquifer system are centered in the Camden County area and the Middlesex and Monmouth County area. Water levels declined as much as 46 feet in these areas over the 6-year period.

The identification of sustainable yield for hot spring regarding water level and temperature

NASA Astrophysics Data System (ADS)

Ke, Kai-Yuan; Tan, Yih-Chi

2017-04-01

In order to sustainably manage and utilize the limited hot spring resource, the cool-hot water exchange model is established by combination of Soil and Water Assessment Tool(SWAT) and SHEMAT. Hot spring in Ziaoxi, Taiwan, is chosen as study area. With data of geography, weather, land use and soil texture, SWAT can simulate precipitation induced infiltration and recharge for SHEMAT. Then SHEMAT is calibrated and verified with in-situ observation data of hot spring temperature and water level. The relation among precipitation, pumping, change of water temperature and water level is thus investigated. The effect of point well pumping, which dramatically lower the water level and temperature, due to prosperous development of hot spring building and industry is also considered for better model calibration. In addition, by employing a modified Hill's method, the sustainable yield is identified. Unlike traditional Hill's method, the modified Hill's method could account for not only the change of water level but also the temperature. As a result, the estimated sustainable yield provide a reasonable availability of hot spring resources without further decline of the water level and temperature.

Monitoring Everglades freshwater marsh water level using L-band synthetic aperture radar backscatter

USGS Publications Warehouse

Kim, Jin-Woo; Lu, Zhong; Jones, John W.; Shum, C.K.; Lee, Hyongki; Jia, Yuanyuan

2014-01-01

The Florida Everglades plays a significant role in controlling floods, improving water quality, supporting ecosystems, and maintaining biodiversity in south Florida. Adaptive restoration and management of the Everglades requires the best information possible regarding wetland hydrology. We developed a new and innovative approach to quantify spatial and temporal variations in wetland water levels within the Everglades, Florida. We observed high correlations between water level measured at in situ gages and L-band SAR backscatter coefficients in the freshwater marsh, though C-band SAR backscatter has no close relationship with water level. Here we illustrate the complementarity of SAR backscatter coefficient differencing and interferometry (InSAR) for improved estimation of high spatial resolution water level variations in the Everglades. This technique has a certain limitation in applying to swamp forests with dense vegetation cover, but we conclude that this new method is promising in future applications to wetland hydrology research.

Consistent estimate of ocean warming, land ice melt and sea level rise from Observations

NASA Astrophysics Data System (ADS)

Blazquez, Alejandro; Meyssignac, Benoît; Lemoine, Jean Michel

2016-04-01

Based on the sea level budget closure approach, this study investigates the consistency of observed Global Mean Sea Level (GMSL) estimates from satellite altimetry, observed Ocean Thermal Expansion (OTE) estimates from in-situ hydrographic data (based on Argo for depth above 2000m and oceanic cruises below) and GRACE observations of land water storage and land ice melt for the period January 2004 to December 2014. The consistency between these datasets is a key issue if we want to constrain missing contributions to sea level rise such as the deep ocean contribution. Numerous previous studies have addressed this question by summing up the different contributions to sea level rise and comparing it to satellite altimetry observations (see for example Llovel et al. 2015, Dieng et al. 2015). Here we propose a novel approach which consists in correcting GRACE solutions over the ocean (essentially corrections of stripes and leakage from ice caps) with mass observations deduced from the difference between satellite altimetry GMSL and in-situ hydrographic data OTE estimates. We check that the resulting GRACE corrected solutions are consistent with original GRACE estimates of the geoid spherical harmonic coefficients within error bars and we compare the resulting GRACE estimates of land water storage and land ice melt with independent results from the literature. This method provides a new mass redistribution from GRACE consistent with observations from Altimetry and OTE. We test the sensibility of this method to the deep ocean contribution and the GIA models and propose best estimates.

CRISM Limb Observations of Aerosols and Water Vapor

NASA Technical Reports Server (NTRS)

Smith, Michael D.; Wolff, M.J.; Clancy, R.T.; Seelos, F.; Murchie, S.L.

2009-01-01

Near-infrared spectra taken in a limb-viewing geometry by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on-board the Mars Reconnaissance Orbiter (MRO) provide a useful tool for probing atmospheric structure. Here we describe preliminary work on the retrieval of vertical profiles of aerosols and water vapor from the CRISM limb observations. The first full set of CRISM limb observations was taken in July 2009, with subsequent limb observations planned once every two months. Each set of limb observations contains about four dozen scans across the limb giving pole-to-pole coverage for two orbits at roughly 100 and 290 W longitude. Radiative transfer modeling taking account of aerosol scattering in the limb-viewing geometry is used to model the observations. The retrievals show the height to which dust and water vapor extend and the location and height of water ice clouds. Results from the First set of CRISM limb observations (July 2009, Ls=300) show dust aerosol well-mixed to about three scale heights above the surface with thin water ice clouds above the dust near the equator and at mid-northern latitudes. Water vapor is concentrated at high southern latitudes.

Lake water levels across the U.S.: What are the spatial patterns and drivers of water level change?

EPA Science Inventory

Background Lake water-level changes affect the physical, chemical, and biological condition of lakes; and we expect that disturbances such as land use conversion, water withdrawal, and climate change may alter water-level regimes and impact lake integrity. However, we have a poor...

Understanding spatial variability in extreme estuarine water levels to inform better coastal management practise.

NASA Astrophysics Data System (ADS)

Lyddon, Charlotte; Plater, Andy, ,, Prof.; Brown, Jenny, ,, Dr.; Leonardi, Nicoletta, ,, Dr.

2017-04-01

Coastal zones worldwide are subject to short term, local variations in sea-level, particularly communities and industries developed on estuaries. Astronomical high tides, meteorological storm surges and increased river flow present a combined flood hazard. This can elevate water level at the coast above predicted levels, generating extreme water levels. These contributions can also interact to alter the phase and amplitude of tides and surges, and thus cause significant mismatches between the predicted and observed water level. The combined effect of tide, surge, river flow and their interactions are the key to understanding and assessing flood risk in estuarine environments for design purposes. Delft3D-FLOW, a hydrodynamic model which solves the unsteady shallow-water equation, is used to access spatial variability in extreme water levels for a range of historical events of different severity within the Severn Estuary, southwest England. Long-term tide gauge records from Ilfracombe and Mumbles and river level data from Sandhurst are analysed to generate a series of extreme water level events, representing the 90th, 95th and 99th percentile conditions, to force the model boundaries. To separate out the time-varying contributions of tidal, fluvial, meteorological processes and their interactions the model is run with different physical forcing. A low pass filter is applied to "de-tide" the residual water elevation, to separate out the time-varying meteorological residual and the tide-surge interactions within the surge. The filtered surge is recombined with the predicted tide so the peak occurs at different times relative to high water. The resulting time series are used to force the model boundary to identify how the interactive processes influence the timing of extreme water level across the estuarine domain. This methodology is first validated using the most extreme event on record to ensure that modelled extreme water levels can be predicted with confidence

Water-level conditions in the confined aquifers of the New Jersey Coastal Plain, 2008

USGS Publications Warehouse

Depaul, Vincent T.; Rosman, Robert

2015-01-01

From 1998 to 2008, downward water-level trends were observed at 22 wells (29 percent), upward trends were observed at 21 wells (27 percent), and insubstantial trends at 34 wells (44 percent). Downward trends were detected most often at wells open to the Piney Point aquifer and the Atlantic City 800-foot sand. Upward water-level trends were most frequent in wells open to the Englishtown aquifer system in Critical Area 1 and in wells within the Potomac-Raritan-Magothy aquifer system in southern New Jersey.

Estimation of the discharges of the multiple water level stations by multi-objective optimization

NASA Astrophysics Data System (ADS)

Matsumoto, Kazuhiro; Miyamoto, Mamoru; Yamakage, Yuzuru; Tsuda, Morimasa; Yanami, Hitoshi; Anai, Hirokazu; Iwami, Yoichi

2016-04-01

This presentation shows two aspects of the parameter identification to estimate the discharges of the multiple water level stations by multi-objective optimization. One is how to adjust the parameters to estimate the discharges accurately. The other is which optimization algorithms are suitable for the parameter identification. Regarding the previous studies, there is a study that minimizes the weighted error of the discharges of the multiple water level stations by single-objective optimization. On the other hand, there are some studies that minimize the multiple error assessment functions of the discharge of a single water level station by multi-objective optimization. This presentation features to simultaneously minimize the errors of the discharges of the multiple water level stations by multi-objective optimization. Abe River basin in Japan is targeted. The basin area is 567.0km2. There are thirteen rainfall stations and three water level stations. Nine flood events are investigated. They occurred from 2005 to 2012 and the maximum discharges exceed 1,000m3/s. The discharges are calculated with PWRI distributed hydrological model. The basin is partitioned into the meshes of 500m x 500m. Two-layer tanks are placed on each mesh. Fourteen parameters are adjusted to estimate the discharges accurately. Twelve of them are the hydrological parameters and two of them are the parameters of the initial water levels of the tanks. Three objective functions are the mean squared errors between the observed and calculated discharges at the water level stations. Latin Hypercube sampling is one of the uniformly sampling algorithms. The discharges are calculated with respect to the parameter values sampled by a simplified version of Latin Hypercube sampling. The observed discharge is surrounded by the calculated discharges. It suggests that it might be possible to estimate the discharge accurately by adjusting the parameters. In a sense, it is true that the discharge of a water

On the derivation of specific yield and soil water retention characteristics in peatlands from rainfall, microrelief and water level data - Theory and Practice

NASA Astrophysics Data System (ADS)

Dettmann, Ullrich; Bechtold, Michel

2016-04-01

Water level depth is one of the crucial state variables controlling the biogeochemical processes in peatlands. For flat soil surfaces, water level depth dynamics as response to boundary fluxes are primarily controlled by the water retention characteristics of the soil in and above the range of the water level fluctuations. For changing water levels, the difference of the integrals of two soil moisture profiles (ΔAsoil), of a lower and a upper water level, is equal to the amount of water received or released by the soil. Dividing ΔAsoil by the water level change, results into a variable that is known as specific yield (Sy). For water level changes approaching the soil surface, changes in soil water storage are small due to the thin unsaturated zone that remains. Consequentially, Sy values approach zero with an abrupt transition to 1 in case of inundation. However, on contrary, observed water level rises due to precipitation events at various locations showed increasing Sy values for water level changes at shallow depths (Sy = precipitation/water level change; Logsdon et al., 2010). The increase of Sy values can be attributed in large parts to the influence of the microrelief on water level changes in these wet landscapes that are characterized by a mosaic of inundated and non-inundated areas. Consequentially, water level changes are dampened by partial inundation. In this situation, total Sy is composed of a spatially-integrated below ground and above ground contribution. We provide a general one-dimensional expression that correctly represents the effect of a microrelief on the total Sy. The one-dimensional expression can be applied for any soil hydraulic parameterizations and soil surface elevation frequency distributions. We demonstrate that Sy is influenced by the microrelief not only when surface storage directly contributes to Sy by (partial) inundation but also when water levels are lower than the minimum surface elevation. With the derived one

Integrating space geodesy and coastal sea level observations

NASA Astrophysics Data System (ADS)

Löfgren, J. S.; Haas, R.; Larson, K.; Scherneck, H.-G.

2012-04-01

The goal of the Global Geodetic Observing System (GGOS) is to monitor the Earth system, in particular with observations of the three fundamental geodetic observables: the Earth's shape, the Earth's gravity field and the Earth's rotational motion. A central part of GGOS is the network of globally distributed fundamental geodetic stations that allow the combination and integration of the different space geodetic techniques. One of these stations is the Onsala Space Observatory (OSO), on the west coast of Sweden, which operates equipment for geodetic Very Long Baseline Interferometry, Global Navigation Satellite System (GNSS), and superconducting gravimetry measurements, and additionally water vapour radiometers. The newest addition to the OSO fundamental geodetic station is a GNSS-based tide gauge (GNSS-TG). This installation integrates space geodesy with remote sensing of the local sea level. The GNSS-TG uses both direct GNSS-signals and GNSS-signals that are reflected off the sea surface. This is done using a zenith-looking Right Hand Circular Polarized (RHCP) and a nadir-looking Left Hand Circular Polarized (LHCP) antenna, respectively. Each of the two antennas is connected to a standard geodetic-type GNSS-receiver. The analysis of the data received with the RHCP-antenna allows one to determine land motion, while the analysis of the data received with the LHCP-antenna allows one to determine the sea surface height. Analysing both data sets together results in local sea level that is automatically corrected for land motion, meaning that the GNSS-TG can provide reliable sea-level estimates even in tectonically active regions. Previous results from the GNSS-TG, using carrier phase data, show a Root-Mean-Square (RMS) agreement of less than 5.9 cm with stilling well gauges located 18 km and 33 km away from OSO (Löfgren et al., 2011). This is lower than the RMS agreement between the two stilling well gauges (6.1 cm). Furthermore, significant ocean tidal signals have

Subseasonal to Seasonal Predictions of U.S. West Coast High Water Levels

NASA Astrophysics Data System (ADS)

Khouakhi, A.; Villarini, G.; Zhang, W.; Slater, L. J.

2017-12-01

Extreme sea levels pose a significant threat to coastal communities, ecosystems, and assets, as they are conducive to coastal flooding, coastal erosion and inland salt-water intrusion. As sea levels continue to rise, these sea level extremes - including occasional minor coastal flooding experienced during high tide (nuisance floods) - are of concern. Extreme sea levels are increasing at many locations around the globe and have been attributed largely to rising mean sea levels associated with intra-seasonal to interannual climate processes such as the El Niño-Southern Oscillation (ENSO). Here, intra-seasonal to seasonal probabilistic forecasts of high water levels are computed at the Toke Point tide gage station on the US west coast. We first identify the main climate drivers that are responsible for high water levels and examine their predictability using General Circulation Models (GCMs) from the North American Multi-Model Ensemble (NMME). These drivers are then used to develop a probabilistic framework for the seasonal forecasting of high water levels. We focus on the climate controls on the frequency of high water levels using the number of exceedances above the 99.5th percentile and above the nuisance flood level established by the National Weather Service. Our findings indicate good forecast skill at the shortest lead time, with the skill that decreases as we increase the lead time. In general, these models aptly capture the year-to-year variability in the observational records.

Hydrogeology and simulation of regional ground-water-level declines in Monroe County, Michigan

USGS Publications Warehouse

Reeves, Howard W.; Wright, Kirsten V.; Nicholas, J.R.

2004-01-01

Observed ground-water-level declines from 1991 to 2003 in northern Monroe County, Michigan, are consistent with increased ground-water demands in the region. In 1991, the estimated ground-water use in the county was 20 million gallons per day, and 80 percent of this total was from quarry dewatering. In 2001, the estimated ground-water use in the county was 30 million gallons per day, and 75 percent of this total was from quarry dewatering. Prior to approximately 1990, the ground-water demands were met by capturing natural discharge from the area and by inducing leakage through glacial deposits that cover the bedrock aquifer. Increased ground-water demand after 1990 led to declines in ground-water level as the system moves toward a new steady-state. Much of the available natural discharge from the bedrock aquifer had been captured by the 1991 conditions, and the response to additional withdrawals resulted in the observed widespread decline in water levels. The causes of the observed declines were explored through the use of a regional ground-water-flow model. The model area includes portions of Lenawee, Monroe, Washtenaw, and Wayne Counties in Michigan, and portions of Fulton, Henry, and Lucas Counties in Ohio. Factors, including lowered water-table elevations because of below average precipitation during the time period (1991 - 2001) and reduction in water supply to the bedrock aquifer because of land-use changes, were found to affect the regional system, but these factors did not explain the regional decline. Potential ground-water capture for the bedrock aquifer in Monroe County is limited by the low hydraulic conductivity of the overlying glacial deposits and shales and the presence of dense saline water within the bedrock as it dips into the Michigan Basin to the west and north of the county. Hydrogeologic features of the bedrock and the overlying glacial deposits were included in the model design. An important step of characterizing the bedrock aquifer was the

Water levels in major artesian aquifers of the New Jersey Coastal Plain, 1983

USGS Publications Warehouse

Eckel, J.A.; Walker, R.L.

1986-01-01

Water levels and changes in water levels in the major aquifers of the New Jersey Coastal Plain are documented. Water levels in 1,071 wells were measured in 1983, and are compared with 827 water level measurements made in the same wells in 1978. Increased groundwater withdrawals from the major artesian aquifers that underlie the New Jersey Coastal Plain have caused large cones of depression in the artesian heads. These cones are delineated on detailed potentiometric surface maps based on water level data collected in the fall of 1983. Hydrographs from observation wells show trends of water levels for the 6-year period of 1978 through 1983. The Potomac-Raritan-Magothy aquifer system is divided into the lower, middle, and upper aquifers. The potentiometric surfaces in these aquifers form large cones of depression centered in the Camden and Middlesex-Monmouth County areas. Measured water levels declined as much as 23 ft in these areas for the period of study. The lowest levels are 96 ft below sea level in Camden County and 91 ft below sea level in the Middlesex-Monmouth County area. Deep cones of depression in coastal Monmouth and Ocean counties in both the Englishtown aquifer system and Wenonah-Mount Laurel aquifer are similar in location and shape. This is because of an effective hydraulic connection between these aquifers. Measured water levels declined as much as 29 ft in the Englishtown aquifer system and 21 ft in the Wenonah-Mount Laurel aquifer during the period of study. The lowest levels are 249 ft below sea level in the Englishtown aquifer system and 196 ft below sea level in the Wenonah-Mount Laurel aquifer. Water levels in the Piney Point aquifer are as low as 75 ft below sea level at Seaside Park, Ocean County and 35 ft below sea level in southern Cumberland County. Water levels in Cumberland County are affected by large withdrawals of groundwater in Kent County, Delaware. Water levels in the Atlantic City 800 ft sand of the Kirkwood Formation define an

Drinking-water quality and variations in water levels in the fractured crystalline-rock aquifer, west-central Jefferson County, Colorado

USGS Publications Warehouse

Hall, Dennis C.; Johnson, Carl J.

1979-01-01

In parts of Jefferson County, CO, water for domestic use from the fractured crystalline-rock aquifer contained excessive concentrations of major ions, coliform bacteria, trace elements, or radiochemicals. Based on results of analyses from 26 wells, water from 21 of the wells contained excessive concentrations of one or more constituents. Drinking water standards were exceeded for fluoride in water from 2 wells, nitrate plus nitrite in 2 wells, dissolved solids in 1 well, iron in 6 wells, manganese in 8 wells, zinc in 2 wells, coliform bacteria in 4 wells, gross alpha radiation in 11 wells and possibly 4 more, and gross beta radiation possibly in 1 well. Local variations in concentrations of 15 chemical constituents, specific conductance, and water temperature were statistically significant. Specific conductance increased significantly during 1973-75 only in the vicinity of Indian Hills. Annual range in depths to water in 11 observation wells varied from 1 to 15 feet. The shallowest water levels were recorded in late winter, usually in February. The deepest water levels occurred during summer or fall, depending on the well and the year. Three-year trends in water level changes in 6 of the 11 wells indicated decreasing water storage in the aquifer. (USGS).

Ground-water levels in alluvium on the South coast of Puerto Rico, February 1978

USGS Publications Warehouse

Diaz, Jose R.

1979-01-01

Ground-water levels in the alluvial aquifer of the south coast of Puerto Rico in February 1978 were similar to or slightly higher than those of February 1977. Water levels rose about 2 to 3 meters in the northern section near the foothills in the coastal plain area from Salinas to Patillas and in the Guanica-Penuelas area. Pumpage remained unchanged in most of the areas under study. Pumping-water levels were above mean sea level in all industrial well fields. Pumping and static water levels were below mean sea level (1 to 3 meters), in public supply and irrigation wells in the areas of Playa de Ponce, Descalabrado-Punta Petrona, and in the vicinity of the town of Salinas. These levels are considered to be normal for the dry season in these highly irrigated areas. Sixty-four water samples collected from irrigation, industrial and salinity observation wells exhibited similar or lower chloride concentration than in previous years. The average chloride concentration for 1978 was 57 milligrams per liter. (USGS)

Drinking Water Maximum Contaminant Levels (MCLs)

EPA Pesticide Factsheets

National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards protect public health by limiting the levels of contaminants in drinking water.

A Uniform Fault Zone Diffusivity Structure in the Simi Valley Based on Water Level Tidal and Barometric Response

NASA Astrophysics Data System (ADS)

Xue, L.; Brodsky, E. E.; Allègre, V.; Parker, B. L.; Cherry, J. A.

2016-12-01

Water levels inside conventional water wells can tap an artesian aquifer response to pressure head disturbances caused by the Earth tides and surface atmospheric loading. The fluctuation of water levels can measure the hydrogeologic properties of the formation surrounding these wells. Specifically, the amplitude of water level oscillation is determined by formation specific storage, and the phase shift between the water level oscillation and the pressure head disturbance is determined by formation permeability. We utilized 36 wells completed in fractured, interbedded sandstone of turbidite origin in an upland area of southern California to measure the in-situ hydrogeologic properties by combining the water level tidal and barometric responses. This site experiences north-south shortening and it has groups of NE-SW and east-west conjugate faults. The site has been intensively characterized and monitored hydrologically since the 1980's because of the groundwater contamination. Hence, this study provides a good opportunity to measure the in-situ hydrogeologic properties for comparison to other test types and scales. Most of the observed water level tidal responses have a lead phase response, which cannot be interpreted either by the water level response in a confined aquifer or the water level response in an unconfined aquifer. To interpret these observations, we utilized the water level response in a partially confined aquifer, resulting in both positive and negative phase information when fully considering all the observations. Due to the different mechanisms for tidal versus barometric water level responses, the combination can give better constraints on the inverted hydrologic properties. The range of the measured permeability is 10-15-10-13 m2 and the range of the specific storage is 10-7-10-5 1/m. The resulting diffusivity is within 10-2-10-1 m2/s which is relatively uniform. This indicates the fault damages in the site are relatively homogeneous at the scale of

Association between water fluoride and the level of children's intelligence: a dose-response meta-analysis.

PubMed

Duan, Q; Jiao, J; Chen, X; Wang, X

2018-01-01

Higher fluoride concentrations in water have inconsistently been associated with the levels of intelligence in children. The following study summarizes the available evidence regarding the strength of association between fluoridated water and children's intelligence. Meta-analysis. PubMed, Embase, and Cochrane Library databases were systematically analyzed from November 2016. Observational studies that have reported on intelligence levels in relation to high and low water fluoride contents, with 95% confidence intervals (CIs) were included. Further, the results were pooled using inverse variance methods. The correlation between water fluoride concentration and intelligence level was assessed by a dose-response meta-analysis. Twenty-six studies reporting data on 7258 children were included. The summary results indicated that high water fluoride exposure was associated with lower intelligence levels (standardized mean difference : -0.52; 95% CI: -0.62 to -0.42; P < 0.001). The findings from subgroup analyses were consistent with those from overall analysis. The dose-response meta-analysis suggested a significant association between water fluoride dosage and intelligence (P < 0.001), while increased water fluoride exposure was associated with reduced intelligence levels. Greater exposure to high levels of fluoride in water was significantly associated with reduced levels of intelligence in children. Therefore, water quality and exposure to fluoride in water should be controlled in areas with high fluoride levels in water. Copyright © 2017. Published by Elsevier Ltd.

Water-level fluctuations influence sediment porewater ...

EPA Pesticide Factsheets

Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluctuations impact Hg cycling, particularly the formation of the more toxic and bioaccumulative methylmercury (MeHg). Total-Hg (THg), MeHg, stable isotope methylation rates and several ancillary parameters were measured in reservoir sediments (including some in porewater and overlying water) that are seasonally and permanently inundated. The results showed that sediment and porewater MeHg concentrations were over 3-times higher in areas experiencing water-level fluctuations compared to permanently inundated sediments. Analysis of the data suggest that the enhanced breakdown of organic matter in sediments experiencing water-level fluctuations has a two-fold effect on stimulating Hg methylation: 1) it increases the partitioning of inorganic Hg from the solid phase into the porewater phase (lower log Kd values) where it is more bioavailable for methylation; and 2) it increases dissolved organic carbon (DOC) in the porewater which can stimulate the microbial community that can methylate Hg. Sulfate concentrations and cycling were enhanced in the seasonally inundated sediments and may have also contributed to increased MeHg production. Overall, our results suggest that reservoir management a

Surface Water Connectivity, Flow Pathways and Water Level Fluctuation in a Cold Region Deltaic Ecosystem

NASA Astrophysics Data System (ADS)

Peters, D. L.; Niemann, O.; Skelly, R.; Monk, W. A.; Baird, D. J.

2017-12-01

The Peace-Athabasca Delta (PAD) is a 6000 km2 deltaic floodplain ecosystem of international importance (Wood Buffalo National Park, Ramsar Convention, UNESCO World Heritage, and SWOT satellite water level calibration/validation site). The low-relief floodplain formed at the confluence of the Peace, Athabasca and Birch rivers with Lake Athabasca. More than 1000 wetland and lake basins have varying degrees of connectivity to the main flow system. Hydroperiod and water storage is influenced by ice-jam and open-water inundations and prevailing semi-arid climate that control water drawdown. Prior studies have identified pathways of river-to-wetland floodwater connection and historical water level fluctuation/trends as a key knowledge gaps, limiting our knowledge of deltaic ecosystem status and potential hydroecological responses to climate change and upstream water alterations to flow contributions. To address this knowledge gap, surface elevation mapping of the PAD has been conducted since 2012 using aerial remote sensing Light Detection and Ranging (LiDAR), plus thousands of ground based surface and bathymetric survey points tied to Global Positioning System (GPS) were obtained. The elevation information was used to develop a high resolution digital terrain model to simulate and investigate surface water connectivity. Importantly, the surveyed areas contain a set of wetland monitoring sites where ground-based surface water connectivity, water level/depth, water quality, and aquatic ecology (eg, vegetation, macroinvertebrate and muskrat) have been examined. The goal of this presentation is to present an assessment of: i) surface water fluctuation and connectivity for PAD wetland sites; ii) 40+ year inter-annual hydroperiod reconstruction for a perched basin using a combination of field measurements, remote sensing estimates, and historical documents; and iii) outline an approach to integrate newly available hydro-bio-geophysical information into a novel, multi

[The dose-effect relationship of water fluoride levels and renal damage in children].

PubMed

Liu, Jun-Ling; Xia, Tao; Yu, Yao-Yong; Sun, Xian-Zhong; Zhu, Qilong; He, Weihong; Zhang, Ming; Wang, Aiguo

2005-05-01

To explore the dose-effect relationship of water fluoride levels and renal damage in children and observe the difference of renal function between high-loaded fluoride people and dental fluorosis people in the same water fluoride level region. 210 children were divided into seven groups in term of drinking water fluoride levels and whether they suffered from dental fluorosis. Fluoride concentrations in urine and serum and activities of urine NAG and gamma-GT were determined. The urine and serum fluoride of high-loaded fluoride people and dental fluorosis people increased compared with control, moreover fluoride contents in urine and serum increased gradually with the increase of fluoride level in drinking water. Urine NAG and gamma-GT activities significantly increased in dental fluorosis people from area of 2.58 mg/L fluoride in drinking water and in those two groups from area of 4.51 mg/L fluoride in drinking water. Moreover, there existed an obvious dose-effect relationship between the drinking water fluoride concentration and NAG and gamma-GT activity. Over 2.0 mg/L fluoride in drinking water can cause renal damage in children, and the damage degree increases with the drinking water fluoride content. Renal damage degree is not related to whether the children suffered from dental fluorosis and mainly due to water fluoride concentration.

Incorporating water table dynamics in climate modeling: 1. Water table observations and equilibrium water table simulations

NASA Astrophysics Data System (ADS)

Fan, Ying; Miguez-Macho, Gonzalo; Weaver, Christopher P.; Walko, Robert; Robock, Alan

2007-05-01

Soil moisture is a key participant in land-atmosphere interactions and an important determinant of terrestrial climate. In regions where the water table is shallow, soil moisture is coupled to the water table. This paper is the first of a two-part study to quantify this coupling and explore its implications in the context of climate modeling. We examine the observed water table depth in the lower 48 states of the United States in search of salient spatial and temporal features that are relevant to climate dynamics. As a means to interpolate and synthesize the scattered observations, we use a simple two-dimensional groundwater flow model to construct an equilibrium water table as a result of long-term climatic and geologic forcing. Model simulations suggest that the water table depth exhibits spatial organization at watershed, regional, and continental scales, which may have implications for the spatial organization of soil moisture at similar scales. The observations suggest that water table depth varies at diurnal, event, seasonal, and interannual scales, which may have implications for soil moisture memory at these scales.

The Potential Benefits of Earth Observations for the Water-Energy-Food Nexus and Beyond

NASA Astrophysics Data System (ADS)

Lawford, R. G.

2016-12-01

Earth Observations have been shown to have the potential to play an important role in the management of the Water-Energy-Food (W-E-F) Nexus. To date, their primary application has come through support to decisions related to the better use of water in the production of food and in the extraction of energy. However, to be fully effective, the uses of Earth observations should be coordinated across the sectors and appropriately applied at multiple levels of the governance process. This observation argues for a new approach to governance and management of the W-E-F Nexus that implements collaborative planning based on broader usage of Earth observations. The Future Earth W-E-F Nexus Cluster project has documented a number of ways in which Earth observations can support decision-making that benefits the management of these sectors and has identified gaps in the data and information systems needed for this purpose. This presentation will summarize those findings and discuss how the role of Earth observations could be strengthened and expanded to the Sustainable Development Goals and Integrated Water Resources Management.

Carboxyhaemoglobin levels in water-pipe and cigarette smokers.

PubMed

Theron, Ansa; Schultz, Cedric; Ker, James A; Falzone, Nadia

2010-01-29

Water-pipe smoking is growing in popularity, especially among young people, because of the social nature of the smoking session and the assumption that the effects are less harmful than those of cigarette smoking. It has however been shown that a single water-pipe smoking session produces a 24-hour urinary cotinine level equivalent to smoking 10 cigarettes per day. We aimed to measure carboxyhaemoglogin (COHb) blood levels before and after water-pipe and cigarette smoking sessions. Self-confessed smokers older than 18 years (N=30) volunteered to smoke a water-pipe or a cigarette and have their blood COHb levels measured under controlled conditions. Mean baseline COHb levels were 2.9% for the 15 cigarette smokers and 1.0% for the 15 water-pipe smokers. Levels increased by a mean of 481.7% in water-pipe smokers as opposed to 39.9% in cigarette smokers. The study demonstrated that water-pipe smokers had significantly higher increases in blood COHb levels than cigarette smokers during a single smoking session.

Water-level database update for the Death Valley regional groundwater flow system, Nevada and California, 1907-2007

USGS Publications Warehouse

Pavelko, Michael T.

2010-01-01

The water-level database for the Death Valley regional groundwater flow system in Nevada and California was updated. The database includes more than 54,000 water levels collected from 1907 to 2007, from more than 1,800 wells. Water levels were assigned a primary flag and multiple secondary flags that describe hydrologic conditions and trends at the time of the measurement and identify pertinent information about the well or water-level measurement. The flags provide a subjective measure of the relative accuracy of the measurements and are used to identify which water levels are appropriate for calculating head observations in a regional transient groundwater flow model. Included in the report appendix are all water-level data and their flags, selected well data, and an interactive spreadsheet for viewing hydrographs and well locations.

Comparison of self-reported and observed water contact in an S. mansoni endemic village in Brazil.

PubMed

Friedman, J F; Kurtis, J D; McGarvey, S T; Fraga, A L; Silveira, A; Pizziolo, V; Gazzinelli, G; LoVerde, P; Corrêa-Oliveira, R

2001-03-30

Estimates of exposure are critical for immuno-epidemiologic and intervention studies in human schistosomiasis. Direct observation of human water contact patterns is both costly and time consuming. To address these issues, we determined whether individuals residing in a Schistosoma mansoni endemic village in Brazil could accurately self-report their water contact patterns. We compared the results of a water contact questionnaire to the present gold standard, direct observation of water contact in 86 volunteers, aged 8--29. We administered a survey to estimate volunteers' frequency and type of water contact and directly measured each volunteers' water contact patterns during 5 weeks of detailed water contact observations. We found a poor correlation between self reported frequency of contact and directly observed exposure (rho=0.119, P=NS). The questionnaire data was supplemented by information about average body surface area of exposure and duration of contact for specific activities derived from observations of this cohort. This 'supplemented questionnaire' data was significantly correlated with their exposure index (rho=0.227, P=0.05). It provides a starting point from which questionnaires may develop to provide a more cost-effective and less labor intensive method of assessing water contact exposure at the level of the individual.

Observation of Water-Protein Interaction Dynamics with Broadband Two-Dimensional Infrared Spectroscopy

NASA Astrophysics Data System (ADS)

De Marco, Luigi; Haky, Andrew; Tokmakoff, Andrei

Two-dimensional infrared (2D IR) spectroscopy has proven itself an indispensable tool for studying molecular dynamics and intermolecular interactions on ultrafast timescales. Using a novel source of broadband mid-IR pulses, we have collected 2D IR spectra of protein films at varying levels of hydration. With 2D IR, we can directly observe coupling between water's motions and the protein's. Protein films provide us with the ability to discriminate hydration waters from bulk water and thus give us access to studying water dynamics along the protein backbone, fluctuations in the protein structure, and the interplay between the molecular dynamics of the two. We present two representative protein films: poly-L-proline (PLP) and hen egg-white lysozyme (HEWL). Having no N-H groups, PLP allows us to look at water dynamics without interference from resonant energy transfer between the protein N-H stretch and the water O-H stretch. We conclude that at low hydration levels water-protein interactions dominate, and the water's dynamics are tied to those of the protein. In HEWL films, we take advantage of the robust secondary structure to partially deuterate the film, allowing us to spectrally distinguish the protein core from the exterior. From this, we show that resonant energy transfer to water provides an effective means of dissipating excess energy within the protein, while maintaining the structure. These methods are general and can easily be extended to studying specific protein-water interactions.

Selected water-level records for Oklahoma, 1976-1978

USGS Publications Warehouse

Goemaat, Robert L.; Spiser, Dannie E.

1979-01-01

A systematic program to collect water-level records in Oklahoma began in 1937. The objectives of this program are (1) to provide long-term records of water-level fluctuations in representative wells, (2) to facilitate the prediction of water-level trends and indicate future availability of ground-water supplies, and (3) to provide information for use in basic research.Water-level data in table 1 are from wells that are measured annually, prior to the irrigation season, to achieve the most natural representation of the static water level. Water-level measurements listed in the column under 1976 may have been made during December 1975 or January, February, March, April, or May, 1976. Measurements listed in the column 1977 may have been made during December 1976 or January, February, March, or April 1977. Figure 1 shows the counties and number of wells therein, where data were obtained for this report.Records of water levels in Oklahoma are collected through a cooperative program by the U.S. Geological Survey and the Oklahoma Water Resources Board. The records are tabulated and published by the U.S. Geological Survey on an annual basis.The stratigraphic nomenclature and age determinations used in this report are those accepted by the Oklahoma Geological Survey and do not necessarily agree with those of the U.S. Geological Survey except for the Cheyenne Sandstone which is considered to be Purgatoire Sandstone by the Oklahoma Geological Survey (Robert 0. Fay, Personal Communication, August 9, 1979).

Ground-water level data for North Carolina, 1987

USGS Publications Warehouse

Coble, Ronald W.; Strickland, A.G.; Bailey, M. Carl

1989-01-01

Continuous and periodic measurements in 54 key wells and water-level measurements emplaced in Coastal Plain aquifers across North Carolina in 193 supplemental wells are presented in this report. Hydrographs of selected wells show changes in ground-water storage in the State. The water table in the shallow aquifers was higher throughout most of the State in 1987 than in 1986, indicating that rain had recharged these aquifers sufficiently to replenish the deficit in ground water storage that accumulated in the western and central parts of the State during 1986. Water levels in the heavily pumped Coastal Plain aquifers show a general downward trend for the year, indicating ground water is being withdrawn from aquifer storage. Record low water levels were measured in 4 of 13 wells in the Castle Hayne aquifer; the greatest decline measured during 1987 was 0.3 ft. Water levels in wells in the Peedee, Black Creek, upper Cape Fear, and lower Cape Fear aquifers generally show downward trends. Record low water levels were measured in 4 of 8 wells in the Peedee aquifer; the maximum decline measured during 1987 was 1.5 ft. All wells in the Black Creek, upper Cape Fear, and lower Cape Fear aquifers had record low water levels for 1987, with maximum measured declines in 1987 of 8.6, 3.1, and 3.1 ft., respectively. Record high water levels were measured in two wells, one each in the Castle Hayne and Peedee aquifers. Potentiometric surface maps show the effects of major centers of pumping for the Castle Hayne, Black Creek, and lower Cape Fear aquifers of the Coastal Plain.

Non-renewable water use on the globe and its implication to sea level change

NASA Astrophysics Data System (ADS)

Oki, T.; Pokhrel, Y. N.; Hanasaki, N.; Koirala, S.; Kanae, S.

2012-12-01

The real hydrological cycles on the Earth are not natural anymore. Global hydrological model simulations of the water cycle and available water resources should have an ability to consider the effects of human interventions on hydrological cycles. Anthropogenic activity modules, such as reservoir operation, crop growth and water demand in croplands, and environmental flows, were incorporated into a land surface model to form a new model, MAT-HI. Total terrestrial water storages (TWS) in large river basins were estimated using the new model by off-line simulation, and compared with the TWS observed by GRACE for 2002-2007. MAT-HI was further coupled with a module representing the ground water level fluctuations, and consists a new land surface scheme HiGW-MAT (Human Intervention and Ground Water coupled MATSIRO). HiGW-MAT is also associated with a scheme tracing the origin and flow path with the consideration on the sources of water withdrawal from stream flow, medium-size reservoirs and nonrenewable groundwater in addition to precipitation to croplands which enabled the assessment of the origin of water producing major crops. Areas highly dependent on nonrenewable groundwater are detected in the Pakistan, Bangladesh, Western part of India, north and western parts of China, some regions in the Arabian Peninsula, and the western part of the United States through Mexico. Cumulative nonrenewable groundwater withdrawals estimated by the model are corresponding fairly well with the country statistics of total groundwater withdrawals. Ground water table depletions in large aquifers in US estimated by HiGW-MAT were compared with in-situ observational data, and the correspondences are very good. Mean global exploitation of ground water for 2000 estimated by HiGW-MAT is 360 km3/y as an excess of ground water withdrawal over natural recharge into aquifer. This unsustainable groundwater use, together with artificial reservoir water impoundment, climate-driven changes in

Vibrational spectroscopy of water in hydrated lipid multi-bilayers. II. Two-dimensional infrared and peak shift observables within different theoretical approximations.

PubMed

Gruenbaum, Scott M; Pieniazek, Piotr A; Skinner, J L

2011-10-28

In a previous report, we calculated the infrared absorption spectrum and both the isotropic and anisotropic pump-probe signals for the OD stretch of isotopically dilute water in dilauroylphosphatidylcholine (DLPC) multi-bilayers as a function of the lipid hydration level. These results were then compared to recent experimental measurements and are in generally good agreement. In this paper, we will further investigate the structure and dynamics of hydration water using molecular dynamics simulations and calculations of the two-dimensional infrared and vibrational echo peak shift observables for hydration water in DLPC membranes. These observables have not yet been measured experimentally, but future comparisons may provide insight into spectral diffusion processes and hydration water heterogeneity. We find that at low hydration levels the motion of water molecules inside the lipid membrane is significantly arrested, resulting in very slow spectral diffusion. At higher hydration levels, spectral diffusion is more rapid, but still slower than in bulk water. We also investigate the effects of several common approximations on the calculation of spectroscopic observables by computing these observables within multiple levels of theory. The impact of these approximations on the resulting spectra affects our interpretation of these measurements and reveals that, for example, the cumulant approximation, which may be valid for certain systems, is not a good approximation for a highly heterogeneous environment such as hydration water in lipid multi-bilayers.

Description of trihalomethane levels in three UK water suppliers.

PubMed

Whitaker, Heather; Nieuwenhuijsen, Mark J; Best, Nicola; Fawell, John; Gowers, Alison; Elliot, Paul

2003-01-01

Samples of drinking water are routinely analysed for four trihalomethanes (THMs), which are indicators of by-products of disinfection with chlorine, by UK water suppliers to demonstrate compliance with regulations. The THM data for 1992-1993 to 1997-1998 for three water suppliers in the north and midlands of England were made available for a UK epidemiological study of the association between disinfection by-products and adverse birth outcomes. This paper describes the THM levels in these three supply regions and discusses possible sources of variation. THM levels varied between different suppliers' water, and average THM levels were within the regulatory limits. Chloroform was the predominant THM in all water types apart from the ground water of one supplier. The supplier that distributed more ground and lowland surface water had higher dibromochloromethane (DBCM) and bromoform levels and lower chloroform levels than the other two suppliers. In the water of two suppliers, seasonal fluctuations in bromodichloromethane (BDCM) and DBCM levels were found with levels peaking in the summer and autumn. In the other water supplier, chloroform levels followed a similar seasonal trend whereas BDCM and DBCM levels did not. For all three water suppliers, chloroform levels declined throughout 1995 when there was a drought period. There was a moderate positive correlation between the THMs most similar in their structure (chloroform and BDCM, BDCM and DBCM, and DBCM and bromoform) and a slight negative correlation between chloroform and bromoform levels.

Evaluating Water Budget Closure Across Spatial Scales: An Observational Approach through Texas Water Observatory

NASA Astrophysics Data System (ADS)

Gaur, N.; Jaimes, A.; Vaughan, S.; Morgan, C.; Moore, G. W.; Miller, G. R.; Everett, M. E.; Lawing, M.; Mohanty, B.

2017-12-01

Applications varying from improving water conservation practices at the field scale to predicting global hydrology under a changing climate depend upon our ability to achieve water budget closure. 1) Prevalent heterogeneity in soils, geology and land-cover, 2) uncertainties in observations and 3) space-time scales of our control volume and available data are the main factors affecting the percentage of water budget closure that we can achieve. The Texas Water Observatory presents a unique opportunity to observe the major components of the water cycle (namely precipitation, evapotranspiration, root zone soil moisture, streamflow and groundwater) in varying eco-hydrological regions representative of the lower Brazos River basin at multiple scales. The soils in these regions comprise of heavy clays that swell and shrink to create complex preferential pathways in the sub-surface, thus, making the hydrology in this region difficult to quantify. This work evaluates the water budget of the region by varying the control volume in terms of 3 temporal (weekly, monthly and seasonal) and 3 different spatial scales. The spatial scales are 1) Point scale - that is typical for process understanding of water dynamics, 2) Eddy Covariance footprint scale - that is typical of most eco-hydrological applications at the field scale and, 3) Satellite footprint scale- that is typically used in regional and global hydrological analysis. We employed a simple water balance model to evaluate the water budget at all scales. The point scale water budget was assessed using direct observations from hydro-geo-thematically located observation locations within different eddy covariance footprints. At the eddy covariance footprint scale, the sub-surface of each eddy covariance footprint was intensively characterized using electromagnetic induction (EM 38) and the resultant data was used to calculate the inter-point variability to upscale the sub-surface storage while the satellite scale water budget

Recent and late quaternary changes in water level

NASA Technical Reports Server (NTRS)

Walcott, R. I.

1975-01-01

Water level changes of both the Great Lakes and the sea are described along with methods of analyzing water level data. The influence of elastic deformation of the earth and viscosity is discussed. Causes of water level changes reviewed include: earth movements, geoid changes, storm surges or meteorological phenomena, and melting ice in Antarctica, Greenland, and the mountain glaciers.

Evaluation of water levels in major aquifers of the New Jersey coastal plain, 1978

USGS Publications Warehouse

Walker, R.L.

1983-01-01

Increased withdrawals from the major artesian aquifers that underlie the New Jersey Coastal Plain have caused water-level declines and large regional cones of depression. These cones of depression are delineated on detailed potentiometric surface maps produced from water-level data collected in the field in 1978. Water levels for 1978 are compared with those from 1970 or 1973, and water-level changes are evaluated and compared with hydrographs from observation wells. The Potomac-Raritan-Magothy aquifer system is divided into regionally extensive lower and upper aquifers. These aquifers have large cones of depression centered in Camden, Middlesex, and Monmouth Counties. Water levels declined 5 to 20 feet in these areas between 1973 and 1978. Deep cones of depression in coastal Monmouth and Ocean Counties in the Englishtown and Wenonah-Mount Laurel aquifers are similar in location and shape, due to a good hydraulic connection between these aquifers. Water levels declined 2 to 31 feet in the Englishtown aquifer and 12 to 26 feet in the Wenonah-Mount Laurel aquifer between 1973 and 1978. Water levels in the Atlantic City 800-foot sand of the Kirkwood Formation define an extensive elongated cone of depression centered near Margate, Atlantic County. Head changes ranged from a decline of 4 feet to a recovery of 9 feet during 1970-78. The lowest heads in the Cohansey Sand were about 26 feet below sea level at Cape May, Cape May County, and less than 0.5 miles from salty ground water. (USGS)

Development and Test of an Infrastructure Free Real-Time Water Level Measurement System

NASA Astrophysics Data System (ADS)

Breuer, E. R.; Heitsenrether, R.; Hensley, W., III; Krug, W.; Wolcott, D.

2016-02-01

NOAA's Center for Operational Oceanographic Products and Services (CO-OPS) is responsible for developing and maintaining the National Water Level Observation Network (NWLON). NWLON consists of over 200 long term observatories that provide near real-time, 6 minute average, water level observations from locations throughout all U.S. coasts. CO-OPS continually analyzes state-of-the-art and emerging technologies to identify potential improvements in data quality and operating efficiency. NOAA, recognizing the changing conditions, anticipates a critical need for real time oceanographic and meteorological observations where traditional approaches are less feasible. CO-OPS is working on the design, development and testing of a real-time tidal measurement system, "The Hermit," for use in coastal regions. The latest prototype has recently completed a successful 3 month field test deployment in the St Andrews Sound region of Georgia, a location where relatively few long term water level records have been collected to date. The test location provided unique challenges such as having a very limited coastal infrastructure and experiencing a 7-8 foot tidal range. The Hermit consists of a bottom mounted pressure/conductivity/temperature sensor (Seabird SBE 26+) and a surface communications buoy which are linked via acoustic modems (Link Quest). The surface buoy relays data back to the CO-OPS database in near-real time using an Iridium satellite based communication system. Additionally, the buoy includes an AirMar all-in-one meteorological sensor. In addition to The Hermit deployment, three test GPS bench marks and a tide staff were installed on a nearby coastline to vertically reference water level measurements. During this deployment, The Hermit successfully provided near real-time measurements of bottom pressure, water conductivity and temperature, wind speed and direction, air temperature, and barometric pressure over the 3 month deployment. During the test period, several

Estimation of water level and steam temperature using ensemble Kalman filter square root (EnKF-SR)

NASA Astrophysics Data System (ADS)

Herlambang, T.; Mufarrikoh, Z.; Karya, D. F.; Rahmalia, D.

2018-04-01

The equipment unit which has the most vital role in the steam-powered electric power plant is boiler. Steam drum boiler is a tank functioning to separate fluida into has phase and liquid phase. The existence in boiler system has a vital role. The controlled variables in the steam drum boiler are water level and the steam temperature. If the water level is higher than the determined level, then the gas phase resulted will contain steam endangering the following process and making the resulted steam going to turbine get less, and the by causing damages to pipes in the boiler. On the contrary, if less than the height of determined water level, the resulted height will result in dry steam likely to endanger steam drum. Thus an error was observed between the determined. This paper studied the implementation of the Ensemble Kalman Filter Square Root (EnKF-SR) method in nonlinear model of the steam drum boiler equation. The computation to estimate the height of water level and the temperature of steam was by simulation using Matlab software. Thus an error was observed between the determined water level and the steam temperature, and that of estimated water level and steam temperature. The result of simulation by Ensemble Kalman Filter Square Root (EnKF-SR) on the nonlinear model of steam drum boiler showed that the error was less than 2%. The implementation of EnKF-SR on the steam drum boiler r model comprises of three simulations, each of which generates 200, 300 and 400 ensembles. The best simulation exhibited the error between the real condition and the estimated result, by generating 400 ensemble. The simulation in water level in order of 0.00002145 m, whereas in the steam temperature was some 0.00002121 kelvin.

Determining return water levels at ungauged coastal sites: a case study for northern Germany

NASA Astrophysics Data System (ADS)

Arns, Arne; Wahl, Thomas; Haigh, Ivan D.; Jensen, Jürgen

2015-04-01

We estimate return periods and levels of extreme still water levels for the highly vulnerable and historically and culturally important small marsh islands known as the Halligen, located in the Wadden Sea offshore of the coast of northern Germany. This is a challenging task as only few water level records are available for this region, and they are currently too short to apply traditional extreme value analysis methods. Therefore, we use the Regional Frequency Analysis (RFA) approach. This originates from hydrology but has been used before in several coastal studies and is also currently applied by the local federal administration responsible for coastal protection in the study area. The RFA enables us to indirectly estimate return levels by transferring hydrological information from gauged to related ungauged sites. Our analyses highlight that this methodology has some drawbacks and may over- or underestimate return levels compared to direct analyses using station data. To overcome these issues, we present an alternative approach, combining numerical and statistical models. First, we produced a numerical multidecadal model hindcast of water levels for the entire North Sea. Predicted water levels from the hindcast are bias corrected using the information from the available tide gauge records. Hence, the simulated water levels agree well with the measured water levels at gauged sites. The bias correction is then interpolated spatially to obtain correction functions for the simulated water levels at each coastal and island model grid point in the study area. Using a recommended procedure to conduct extreme value analyses from a companion study, return water levels suitable for coastal infrastructure design are estimated continuously along the entire coastline of the study area, including the offshore islands. A similar methodology can be applied in other regions of the world where tide gauge observations are sparse.

Hydrogeology, ground-water use, and ground-water levels in the Mill Creek Valley near Evendale, Ohio

USGS Publications Warehouse

Schalk, Charles; Schumann, Thomas

2002-01-01

Withdrawals of ground water in the central Mill Creek Valley near Evendale, Ohio, caused water-level declines of more than 100 feet by the 1950s. Since the 1950s, management practices have changed to reduce the withdrawals of ground water, and recovery of water levels in long-term monitoring wells in the valley has been documented. Changing conditions such as these prompted a survey of water use, streamflow conditions, and water levels in several aquifers in the central Mill Creek Valley, Hamilton and Butler Counties, Ohio. Geohydrologic information, water use, and water levels were compiled from historical records and collected during the regional survey. Data collected during the survey are presented in terms of updated geohydrologic information, water use in the study area, water levels in the aquifers, and interactions between ground water and surface water. Some of the data are concentrated at former Air Force Plant 36 (AFP36), which is collocated with the General Electric Aircraft Engines (GEAE) plant, and these data are used to describe geohydrology and water levels on a more local scale at and near the plant. A comparison of past and current ground-water use and levels indicates that the demand for ground water is decreasing and water levels are rising. Before 1955, most of the major industrial ground-water users had their own wells, ground water was mined from a confined surficial (lower) aquifer, and water levels were more than 100 feet below their predevelopment level. Since 1955, however, these users have been purchasing their water from the city of Cincinnati or a private water purveyor. The cities of Reading and Lockland, both producers of municipal ground-water supplies in the area, shut down their well fields within their city limits. Because the demand for ground-water supplies in the valley has lessened greatly since the 1950s, withdrawals have decreased, and, consequently, water levels in the lower aquifer are 65 to 105 feet higher than they were

Water levels prior to January 1, 1954 in observation wells, in Nebraska: part 1. Adams through Howard Counties

USGS Publications Warehouse

Keech, C.F.; Case, R.L.

1954-01-01

During the fall of 1945, as part of the program for the development of the resources of the Missouri River basin, the United States Geological Survey began a new series of groundwater investigation in Nebraska.  Those studies were coordinated with the already existing program of ground-water studies that was begun in 1930 by the U.S. Geological Survey in cooperation with the Conservation and Survey Division of the University of Nebraska. Most of the water-level measurements in this report were obtained and compiled as part of the Missouri Basin Development Program.

Model-Aided Altimeter-Based Water Level Forecasting System in Mekong River

NASA Astrophysics Data System (ADS)

Chang, C. H.; Lee, H.; Hossain, F.; Okeowo, M. A.; Basnayake, S. B.; Jayasinghe, S.; Saah, D. S.; Anderson, E.; Hwang, E.

2017-12-01

Mekong River, one of the massive river systems in the world, has drainage area of about 795,000 km2 covering six countries. People living in its drainage area highly rely on resources given by the river in terms of agriculture, fishery, and hydropower. Monitoring and forecasting the water level in a timely manner, is urgently needed over the Mekong River. Recently, using TOPEX/Poseidon (T/P) altimetry water level measurements in India, Biancamaria et al. [2011] has demonstrated the capability of an altimeter-based flood forecasting system in Bangladesh, with RMSE from 0.6 - 0.8 m for lead times up to 5 days on 10-day basis due to T/P's repeat period. Hossain et al. [2013] further established a daily water level forecasting system in Bangladesh using observations from Jason-2 in India and HEC-RAS hydraulic model, with RMSE from 0.5 - 1.5 m and an underestimating mean bias of 0.25 - 1.25 m. However, such daily forecasting system relies on a collection of Jason-2 virtual stations (VSs) to ensure frequent sampling and data availability. Since the Mekong River is a meridional river with few number of VSs, the direct application of this system to the Mekong River becomes challenging. To address this problem, we propose a model-aided altimeter-based forecasting system. The discharge output by Variable Infiltration Capacity hydrologic model is used to reconstruct a daily water level product at upstream Jason-2 VSs based on the discharge-to-level rating curve. The reconstructed daily water level is then used to perform regression analysis with downstream in-situ water level to build regression models, which are used to forecast a daily water level. In the middle reach of the Mekong River from Nakhon Phanom to Kratie, a 3-day lead time forecasting can reach RMSE about 0.7 - 1.3 m with correlation coefficient around 0.95. For the lower reach of the Mekong River, the water flow becomes more complicated due to the reversal flow between the Tonle Sap Lake and the Mekong River

Transforming Water Management: an Emerging Promise of Integrated Earth Observations

NASA Astrophysics Data System (ADS)

Lawford, R. G.

2011-12-01

Throughout its history, civilization has relied on technology to facilitate many of its advances. New innovations and technologies have often provided strategic advantages that have led to transformations in institutions, economies and ultimately societies. Observational and information technologies are leading to significant developments in the water sector. After a brief introduction tracing the role of observational technologies in the areas of hydrology and water cycle science, this talk explores the existing and potential contributions of remote sensing data in water resource management around the world. In particular, it outlines the steps being undertaken by the Group on Earth Observations (GEO) and its Water Task to facilitate capacity building efforts in water management using Earth Observations in Asia, Africa and Latin and Caribbean America. Success stories on the benefits of using Earth Observations and applying GEO principles are provided. While GEO and its capacity building efforts are contributing to the transformation of water management through interoperability, data sharing, and capacity building, the full potential of these contributions has not been fully realized because impediments and challenges still remain.

Improving the Predictability of Severe Water Levels along the Coasts of Marginal Seas

NASA Astrophysics Data System (ADS)

Ridder, N. N.; de Vries, H.; van den Brink, H.; De Vries, H.

2016-12-01

Extreme water levels can lead to catastrophic consequences with severe societal and economic repercussions. Particularly vulnerable are countries that are largely situated below sea level. To support and optimize forecast models, as well as future adaptation efforts, this study assesses the modeled contribution of storm surges and astronomical tides to total water levels under different air-sea momentum transfer parameterizations in a numerical surge model (WAQUA/DCSMv5) of the North Sea. It particularly focuses on the implications for the representation of extreme and rapidly recurring severe water levels over the past decades based on the example of the Netherlands. For this, WAQUA/DCSMv5, which is currently used to forecast coastal water levels in the Netherlands, is forced with ERA Interim reanalysis data. Model results are obtained from two different methodologies to parameterize air-sea momentum transfer. The first calculates the governing wind stress forcing using a drag coefficient derived from the conventional approach of wind speed dependent Charnock constants. The other uses instantaneous wind stress from the parameterization of the quasi-linear theory applied within the ECMWF wave model which is expected to deliver a more realistic forcing. The performance of both methods is tested by validating the model output with observations, paying particular attention to their ability to reproduce rapidly succeeding high water levels and extreme events. In a second step, the common features of and connections between these events are analyzed. The results of this study will allow recommendations for the improvement of water level forecasts within marginal seas and support decisions by policy makers. Furthermore, they will strengthen the general understanding of severe and extreme water levels as a whole and help to extend the currently limited knowledge about clustering events.

Evaluating Observation Influence on Regional Water Budgets in Reanalyses

NASA Technical Reports Server (NTRS)

Bosilovich, Michael G.; Chern, Jiun-Dar; Mocko, David; Robertson, Franklin R.; daSilva, Arlindo M.

2014-01-01

The assimilation of observations in reanalyses incurs the potential for the physical terms of budgets to be balanced by a term relating the fit of the observations relative to a forecast first guess analysis. This may indicate a limitation in the physical processes of the background model, or perhaps inconsistencies in the observing system and its assimilation. In the MERRA reanalysis, an area of long term moisture flux divergence over land has been identified over the Central United States. Here, we evaluate the water vapor budget in this region, taking advantage of two unique features of the MERRA diagnostic output; 1) a closed water budget that includes the analysis increment and 2) a gridded diagnostic output data set of the assimilated observations and their innovations (e.g. forecast departures). In the Central United States, an anomaly occurs where the analysis adds water to the region, while precipitation decreases and moisture flux divergence increases. This is related more to a change in the observing system than to a deficiency in the model physical processes. MERRAs Gridded Innovations and Observations (GIO) data narrow the observations that influence this feature to the ATOVS and Aqua satellites during the 06Z and 18Z analysis cycles. Observing system experiments further narrow the instruments that affect the anomalous feature to AMSUA (mainly window channels) and AIRS. This effort also shows the complexities of the observing system, and the reactions of the regional water budgets in reanalyses to the assimilated observations.

Changes in Breath Trihalomethane Levels Resulting from Household Water-Use Activities

PubMed Central

Gordon, Sydney M.; Brinkman, Marielle C.; Ashley, David L.; Blount, Benjamin C.; Lyu, Christopher; Masters, John; Singer, Philip C.

2006-01-01

Common household water-use activities such as showering, bathing, drinking, and washing clothes or dishes are potentially important contributors to individual exposure to trihalomethanes (THMs), the major class of disinfection by-products of water treated with chlorine. Previous studies have focused on showering or bathing activities. In this study, we selected 12 common water-use activities and determined which may lead to the greatest THM exposures and result in the greatest increase in the internal dose. Seven subjects performed the various water-use activities in two residences served by water utilities with relatively high and moderate total THM levels. To maintain a consistent exposure environment, the activities, exposure times, air exchange rates, water flows, water temperatures, and extraneous THM emissions to the indoor air were carefully controlled. Water, indoor air, blood, and exhaled-breath samples were collected during each exposure session for each activity, in accordance with a strict, well-defined protocol. Although showering (for 10 min) and bathing (for 14 min), as well as machine washing of clothes and opening mechanical dishwashers at the end of the cycle, resulted in substantial increases in indoor air chloroform concentrations, only showering and bathing caused significant increases in the breath chloroform levels. In the case of bromodichloromethane (BDCM), only bathing yielded a significantly higher air level in relation to the preexposure concentration. For chloroform from showering, strong correlations were observed for indoor air and exhaled breath, blood and exhaled breath, indoor air and blood, and tap water and blood. Only water and breath, and blood and breath were significantly associated for chloroform from bathing. For BDCM, significant correlations were obtained for blood and air, and blood and water from showering. Neither dibromochloromethane nor bromoform gave measurable breath concentrations for any of the activities

Reservoir water level forecasting using group method of data handling

NASA Astrophysics Data System (ADS)

Zaji, Amir Hossein; Bonakdari, Hossein; Gharabaghi, Bahram

2018-06-01

Accurately forecasted reservoir water level is among the most vital data for efficient reservoir structure design and management. In this study, the group method of data handling is combined with the minimum description length method to develop a very practical and functional model for predicting reservoir water levels. The models' performance is evaluated using two groups of input combinations based on recent days and recent weeks. Four different input combinations are considered in total. The data collected from Chahnimeh#1 Reservoir in eastern Iran are used for model training and validation. To assess the models' applicability in practical situations, the models are made to predict a non-observed dataset for the nearby Chahnimeh#4 Reservoir. According to the results, input combinations (L, L -1) and (L, L -1, L -12) for recent days with root-mean-squared error (RMSE) of 0.3478 and 0.3767, respectively, outperform input combinations (L, L -7) and (L, L -7, L -14) for recent weeks with RMSE of 0.3866 and 0.4378, respectively, with the dataset from https://www.typingclub.com/st. Accordingly, (L, L -1) is selected as the best input combination for making 7-day ahead predictions of reservoir water levels.

NOAA tsunami water level archive - scientific perspectives and discoveries

NASA Astrophysics Data System (ADS)

Mungov, G.; Eble, M. C.; McLean, S. J.

2013-12-01

The National Oceanic and Atmospheric Administration (NOAA) National Geophysical Data Center (NGDC) and co-located World Data Service for Geophysics (WDS) provides long-term archive, data management, and access to national and global tsunami data. Currently, NGDC archives and processes high-resolution data recorded by the Deep-ocean Assessment and Reporting of Tsunami (DART) network, the coastal-tide-gauge network from the National Ocean Service (NOS) as well as tide-gauge data recorded by all gauges in the two National Weather Service (NWS) Tsunami Warning Centers' (TWCs) regional networks. The challenge in processing these data is that the observations from the deep-ocean, Pacific Islands, Alaska region, and United States West and East Coasts display commonalities, but, at the same time, differ significantly, especially when extreme events are considered. The focus of this work is on how time integration of raw observations (10-seconds to 1-minute) could mask extreme water levels. Analysis of the statistical and spectral characteristics obtained from records with different time step of integration will be presented. Results show the need to precisely calibrate the despiking procedure against raw data due to the significant differences in the variability of deep-ocean and coastal tide-gauge observations. It is shown that special attention should be drawn to the very strong water level declines associated with the passage of the North Atlantic cyclones. Strong changes for the deep ocean and for the West Coast have implications for data quality but these same features are typical for the East Coast regime.

Water level and strain changes preceding and following the August 4, 1985 Kettleman Hills, California, earthquake

USGS Publications Warehouse

Roeloffs, E.; Quilty, E.

1997-01-01

Two of the four wells monitored near Parkfield, California, during 1985 showed water level rises beginning three days before the M4 6.1 Kettleman Hills earthquake. In one of these wells, the 3.0 cm rise was nearly unique in five years of water level data. However, in the other well, which showed a 3.8 cm rise, many other changes of comparable size have been observed. Both wells that did not display pre-earthquake rises tap partially confined aquifers that cannot sustain pressure changes due to tectonic strain having periods longer than several days. We evaluate the effect of partial aquifer confinement on the ability of these four wells to display water level changes in response to aquifer strain. Although the vertical hydraulic diffusivities cannot be determined uniquely, we can find a value of diffusivity for each site that is consistent with the site's tidal and barometric responses as well as with the rate of partial recovery of the coseismic water level drops. Furthermore, the diffusivity for one well is high enough to explain why the preseismic rise could not have been detected there. For the fourth well, the diffusivity is high enough to have reduced the size of the preseismic signal as much as 50%, although it should still have been detectable. Imperfect confinement cannot explain the persistent water level changes in the two partially confined aquifers, but it does show that they were not due to volume strain. The pre-earthquake water level rises may have been precursors to the Kettleman Hills earthquake. If so, they probably were not caused by accelerating slip over the part of the fault plane that ruptured in that earthquake because they are of opposite sign to the observed coseismic water level drops.

Selected water-level records for Oklahoma, 1979-80

USGS Publications Warehouse

Mills, Willard B.; Spiser, Dannie E.

1980-01-01

Water-level data in table 1 are from wells that are measured annually, prior to the irrigation season to achieve the most natural representation of the static water level. Water level measurements listed in the column under 1979 may have been made during December 1978 or January, February, March, April, or May 1979. Measurements listed in the column 1980 may have been made during December 1979 or January, February, March, or April 1980. Figure 1 shows the counties and number of wells therein, where data were obtained for this report. Records of water levels in Oklahoma are obtained through a cooperative program by the Oklahoma Water Resources Board and the U.S. Geological Survey. The Oklahoma Water Resources Board collects water level data for all counties in the State and the records are tabulated and published by the U.S. Geological Survey on an annual basis. The stratigraphic nomenclature and age determinations used in this report are those accepted by the Oklahoma Geological Survey and do not necessarily agree with those at the U.S. Geological Survey except for the Cheyenne Sandstone which is considered to be Purgatoire Sandstone by the Oklahoma Geological Survey (Robert O. Fay, Personal Communication, August 9, 1979).

County Level Assessment of Impaired Waters and Gastrointestinal Infections

EPA Science Inventory

Water quality data are measured at a watershed level and health data are organized at different levels of aggregation therefore, assessing the population-level impact of water quality on health can be difficult. To address this discrepancy and enable the consideration of water ...

Challenges and Alternatives in Tsunami Water Levels Processing in NOAA/NCEI-CO Global Water-Level Data Repository

NASA Astrophysics Data System (ADS)

Mungov, G.; Dunbar, P. K.; Stroker, K. J.; Sweeney, A.

2016-12-01

The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information is data repository for high-resolution, integrated water-level data to support tsunami research, risk assessment and mitigation to protect life and property damages along the coasts. NCEI responsibilities include, but are not limited to process, archiv and distribut and coastal water level data from different sourcesg tsunami and storm-surge inundation, sea-level change, climate variability, etc. High-resolution data for global historical tsunami events are collected by the Deep-ocean Assessment and Reporting of Tsunami (DART®) tsunameter network maintained by NOAA's National Data Buoy Center NDBC, coastal tide-gauges maintained by NOAA's Center for Operational Oceanographic Products and Services (CO-OPS) and Tsunami Warning Centers, historic marigrams and images, bathymetric data, and from other national and international sources. NCEI-CO water level database is developed in close collaboration with all data providers along with NOAA's Pacific Marine Environmental Laboratory. We outline here the present state in water-level data processing regarding the increasing needs for high-precision, homogeneous and "clean" tsunami records from data different sources and different sampling interval. Two tidal models are compared: the Mike Foreman's improved oceanographic model (2009) and the Akaike Bayesian Information Criterion approach applied by Tamura et al. (1991). The effects of filtering and the limits of its application are also discussed along with the used method for de-spiking the raw time series.

Development of a nuclear technique for monitoring water levels in pressurized vehicles

NASA Technical Reports Server (NTRS)

Singh, J. J.; Davis, W. T.; Mall, G. H.

1983-01-01

A new technique for monitoring water levels in pressurized stainless steel cylinders was developed. It is based on differences in attenuation coefficients of water and air for Cs137 (662 keV) gamma rays. Experimentally observed gamma ray counting rates with and without water in model reservoir cylinder were compared with corresponding calculated values for two different gamma ray detection theshold energies. Calculated values include the effects of multiple scattering and attendant gamma ray energy reductions. The agreement between the measured and calculated values is reasonably good. Computer programs for calculating angular and spectral distributions of scattered radition in various media are included.

Effects of Full-Scale Beach Renovation on Fecal Indicator Levels in Shoreline Sand and Water

PubMed Central

Hernandez, Rafael J.; Hernandez, Yasiel; Jimenez, Nasly H.; Piggot, Alan M.; Klaus, James S.; Feng, Zhixuan; Reniers, Ad; Solo-Gabriele, Helena M.

2013-01-01

Recolonization of enterococci, at a non-point source beach known to contain high background levels of bacteria, was studied after a full-scale beach renovation project. The renovation involved importation of new exogenous sand, in addition to infrastructure improvements. The study's objectives were to document changes in sand and water quality and to evaluate the relative contribution of different renovation activities towards these changes. These objectives were addressed: by measuring enterococci levels in the sand and fecal indicator bacteria levels (enterococci and fecal coliform) in the water, by documenting sediment characteristics (mineralogy and biofilm levels), and by estimating changes in observable enterococci loads. Analysis of enterococci levels on surface sand and within sediment depth cores were significantly higher prior to beach renovation (6.3 to 72 CFU/g for each sampling day) when compared to levels during and after beach renovation (0.8 CFU/g to 12 CFU/g) (p<0.01). During the renovation process, sand enterococci levels were frequently below detection limits (<0.1 CFU/g). For water, exceedances in the regulatory thresholds that would trigger a beach advisory decreased by 40% for enterococci and by 90% for fecal coliform. Factors that did not change significantly between pre- and post- renovation included the enterococci loads from animals (approx. 3 × 1011 CFU per month). Factors that were observed to change between pre- and post- renovation activities included: the composition of the beach sand (64% versus 98% quartz, and a significant decrease in biofilm levels) and loads from direct stormwater inputs (reduction of 3 × 1011 CFU per month). Overall, this study supports that beach renovation activities contributed to improved sand and water quality resulting in a 50% decrease of observable enterococci loads due to upgrades to the stormwater infrastructure. Of interest was that the change in the sand mineralogy also coincided with changes in

Effects of full-scale beach renovation on fecal indicator levels in shoreline sand and water.

PubMed

Hernandez, Rafael J; Hernandez, Yasiel; Jimenez, Nasly H; Piggot, Alan M; Klaus, James S; Feng, Zhixuan; Reniers, Ad; Solo-Gabriele, Helena M

2014-01-01

Recolonization of enterococci, at a non-point source beach known to contain high background levels of bacteria, was studied after a full-scale beach renovation project. The renovation involved importation of new exogenous sand, in addition to infrastructure improvements. The study's objectives were to document changes in sand and water quality and to evaluate the relative contribution of different renovation activities towards these changes. These objectives were addressed: by measuring enterococci levels in the sand and fecal indicator bacteria levels (enterococci and fecal coliform) in the water, by documenting sediment characteristics (mineralogy and biofilm levels), and by estimating changes in observable enterococci loads. Analysis of enterococci levels on surface sand and within sediment depth cores were significantly higher prior to beach renovation (6.3-72 CFU/g for each sampling day) when compared to levels during and after beach renovation (0.8-12 CFU/g) (P < 0.01). During the renovation process, sand enterococci levels were frequently below detection limits (<0.1 CFU/g). For water, exceedances in the regulatory thresholds that would trigger a beach advisory decreased by 40% for enterococci and by 90% for fecal coliform. Factors that did not change significantly between pre- and post- renovation included the enterococci loads from animals (approx. 3 × 10(11) CFU per month). Factors that were observed to change between pre- and post- renovation activities included: the composition of the beach sand (64% versus 98% quartz, and a significant decrease in biofilm levels) and loads from direct stormwater inputs (reduction of 3 × 10(11) CFU per month). Overall, this study supports that beach renovation activities contributed to improved sand and water quality resulting in a 50% decrease of observable enterococci loads due to upgrades to the stormwater infrastructure. Of interest was that the change in the sand mineralogy also coincided with changes in biofilm

Important observations and parameters for a salt water intrusion model

USGS Publications Warehouse

Shoemaker, W.B.

2004-01-01

Sensitivity analysis with a density-dependent ground water flow simulator can provide insight and understanding of salt water intrusion calibration problems far beyond what is possible through intuitive analysis alone. Five simple experimental simulations presented here demonstrate this point. Results show that dispersivity is a very important parameter for reproducing a steady-state distribution of hydraulic head, salinity, and flow in the transition zone between fresh water and salt water in a coastal aquifer system. When estimating dispersivity, the following conclusions can be drawn about the data types and locations considered. (1) The "toe" of the transition zone is the most effective location for hydraulic head and salinity observations. (2) Areas near the coastline where submarine ground water discharge occurs are the most effective locations for flow observations. (3) Salinity observations are more effective than hydraulic head observations. (4) The importance of flow observations aligned perpendicular to the shoreline varies dramatically depending on distance seaward from the shoreline. Extreme parameter correlation can prohibit unique estimation of permeability parameters such as hydraulic conductivity and flow parameters such as recharge in a density-dependent ground water flow model when using hydraulic head and salinity observations. Adding flow observations perpendicular to the shoreline in areas where ground water is exchanged with the ocean body can reduce the correlation, potentially resulting in unique estimates of these parameter values. Results are expected to be directly applicable to many complex situations, and have implications for model development whether or not formal optimization methods are used in model calibration.

Important observations and parameters for a salt water intrusion model.

PubMed

Shoemaker, W Barclay

2004-01-01

Sensitivity analysis with a density-dependent ground water flow simulator can provide insight and understanding of salt water intrusion calibration problems far beyond what is possible through intuitive analysis alone. Five simple experimental simulations presented here demonstrate this point. Results show that dispersivity is a very important parameter for reproducing a steady-state distribution of hydraulic head, salinity, and flow in the transition zone between fresh water and salt water in a coastal aquifer system. When estimating dispersivity, the following conclusions can be drawn about the data types and locations considered. (1) The "toe" of the transition zone is the most effective location for hydraulic head and salinity observations. (2) Areas near the coastline where submarine ground water discharge occurs are the most effective locations for flow observations. (3) Salinity observations are more effective than hydraulic head observations. (4) The importance of flow observations aligned perpendicular to the shoreline varies dramatically depending on distance seaward from the shoreline. Extreme parameter correlation can prohibit unique estimation of permeability parameters such as hydraulic conductivity and flow parameters such as recharge in a density-dependent ground water flow model when using hydraulic head and salinity observations. Adding flow observations perpendicular to the shoreline in areas where ground water is exchanged with the ocean body can reduce the correlation, potentially resulting in unique estimates of these parameter values. Results are expected to be directly applicable to many complex situations, and have implications for model development whether or not formal optimization methods are used in model calibration.

Dynamically balanced absolute sea level of the global ocean derived from near-surface velocity observations

NASA Astrophysics Data System (ADS)

Niiler, Pearn P.; Maximenko, Nikolai A.; McWilliams, James C.

2003-11-01

The 1992-2002 time-mean absolute sea level distribution of the global ocean is computed for the first time from observations of near-surface velocity. For this computation, we use the near-surface horizontal momentum balance. The velocity observed by drifters is used to compute the Coriolis force and the force due to acceleration of water parcels. The anomaly of horizontal pressure gradient is derived from satellite altimetry and corrects the temporal bias in drifter data distribution. NCEP reanalysis winds are used to compute the force due to Ekman currents. The mean sea level gradient force, which closes the momentum balance, is integrated for mean sea level. We find that our computation agrees, within uncertainties, with the sea level computed from the geostrophic, hydrostatic momentum balance using historical mean density, except in the Antarctic Circumpolar Current. A consistent horizontally and vertically dynamically balanced, near-surface, global pressure field has now been derived from observations.

A statistical model for water quality predictions from a river discharge using coastal observations

NASA Astrophysics Data System (ADS)

Kim, S.; Terrill, E. J.

2007-12-01

Understanding and predicting coastal ocean water quality has benefits for reducing human health risks, protecting the environment, and improving local economies which depend on clean beaches. Continuous observations of coastal physical oceanography increase the understanding of the processes which control the fate and transport of a riverine plume which potentially contains high levels of contaminants from the upstream watershed. A data-driven model of the fate and transport of river plume water from the Tijuana River has been developed using surface current observations provided by a network of HF radar operated as part of a local coastal observatory that has been in place since 2002. The model outputs are compared with water quality sampling of shoreline indicator bacteria, and the skill of an alarm for low water quality is evaluated using the receiver operating characteristic (ROC) curve. In addition, statistical analysis of beach closures in comparison with environmental variables is also discussed.

Regional Water Table (2002) and Water-Level Changes in the Mojave River and Morongo Ground-Water Basins, Southwestern Mojave Desert, California

USGS Publications Warehouse

Smith, Gregory A.; Stamos, Christina L.; Predmore, Steven K.

2004-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During 2002, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 600 wells, providing coverage for most of the basins. Twenty-eight hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 9 short-term (1997 to 2002) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 2000 and 2002 water levels throughout the basins. In the Mojave River ground-water basin, about 66 percent of the wells had water-level declines of 0.5 ft or more since 2000 and about 27 percent of the wells had water-level declines greater than 5 ft. The only area that had water-level increases greater than 5 ft that were not attributed to fluctuations in nearby pumpage was in the Harper Lake (dry) area where there has been a significant reduction in pumpage during the last decade. In the Morongo ground-water basin, about 36 percent of the wells had water-level declines of 0.5 ft or more and about 10 percent of the wells had water-level declines greater than 5 ft. Water-level increases greater than 5 ft were measured only in the Warren subbasin, where artificial

Observed reflectivities and liquid water content for marine stratocumulus

NASA Technical Reports Server (NTRS)

Coakley, J. A., Jr.; Snider, J. B.

1989-01-01

Simultaneous observations of cloud liquid water content and cloud reflectivity are used to verify their parametric relationship in a manner consistent with simple parameterizations often used in general-circulation climate models. The column amount of cloud liquid water was measured with a microwave radiometer on San Nicolas Island as described by Hogg et al., (1983). Cloud reflectivity was obtained through spatial coherence analysis of AVHRR imagery data as per Coakley and Baldwin (1984) and Coakley and Beckner (1988). The dependence of the observed reflectivity on the observed liquid water is discussed, and this empirical relationship is compared with the parameterization proposed by Stephens (1978).

Sensitivity of the High Altitude Water Cherenkov Experiment to observe Gamma-Ray Bursts

NASA Astrophysics Data System (ADS)

González, M. M.

Ground based telescopes have marginally observed very high energy emission (>100GeV) from gamma-ray bursts(GRB). For instance, Milagrito observed GRB970417a with a significance of 3.7 sigmas over the background. Milagro have not yet observed TeV emission from a GRB with its triggered and untriggered searches or GeV emission with a triggered search using its scalers. These results suggest the need of new observatories with higher sensitivity to transient sources. The HAWC (High Altitute Water Cherenkov) observatory is proposed as a combination of the Milagro tecnology with a very high altitude (>4000m over see level) site. The expected HAWC sensitivity for GRBs is at least >10 times the Milagro sensitivity. In this work HAWC sensitivity for GRBs is discussed for different detector configurations such as altitude, distance between PMTs, depth under water of PMTs, number of PMTs required for a trigger, etc.

Design of capacitive sensor for water level measurement

NASA Astrophysics Data System (ADS)

Qurthobi, A.; Iskandar, R. F.; Krisnatal, A.; Weldzikarvina

2016-11-01

Capacitive sensor for water level detection has been fabricated. It has, typically, high-impedance sensor, particularly at low frequencies, as clear from the impedance (reactance) expression for a capacitor. Also, capacitive sensor is a noncontacting device in the common usage. In this research, water level sensor based on capacitive principal created using two copper plates with height (h), width (b), and distance (l) between two plates, respectively, 0.040 m, 0.015 m, and 0.010 m. 5 V pp 3 kHz AC signal is used as input signal for the system. Dielectric constant between two plates is proportional to water level. Hence, it can be used to determine water level from electrical characteristic as it inversely proportional to sensor impedance. Linearization, inverting amplifier, and rectifier circuits are used as signal conditioning for the system. Based on conducted experiment, the relationship between water level (x), capacitance (C), and output voltage (Vdc ) can be expressed as C(x) = 2.756x + 0.333 nF and Vdc (x) = 15.755 + 0.316 V.

Water-Level Changes in Aquifers of the Atlantic Coastal Plain, Predevelopment to 2000

USGS Publications Warehouse

dePaul, Vincent T.; Rice, Donald E.; Zapecza, Otto S.

2008-01-01

The Atlantic Coastal Plain aquifer system, which underlies a large part of the east coast of the United States, is an important source of water for more than 20 million people. As the population of the region increases, further demand is being placed on those ground-water resources. To define areas of past and current declines in ground-water levels, as well as to document changes in those levels, historical water-level data from more than 4,000 wells completed in 13 regional aquifers in the Atlantic Coastal Plain were examined. From predevelopment to 1980, substantial water-level declines occurred in many areas of the Atlantic Coastal Plain. Regional variability in water-level change in the confined aquifers of the Atlantic Coastal Plain resulted from regional differences in aquifer properties and patterns of ground-water withdrawals. Within the Northern Atlantic Coastal Plain, declines of more than 100 ft were observed in New Jersey, Delaware, Maryland, Virginia, and North Carolina. Regional declines in water levels were most widespread in the deeper aquifers that were most effectively confined?the Upper, Middle, and Lower Potomac aquifers. Within these aquifers, water levels had declined up to 200 ft in southern Virginia and to more than 100 ft in New Jersey, Delaware, Maryland, and North Carolina. Substantial water-level declines were also evident in the regional Lower Chesapeake aquifer in southeastern New Jersey; in the Castle Hayne-Piney Point aquifer in Delaware, Maryland, southern Virginia and east-central North Carolina; in the Peedee-Severn aquifer in east-central New Jersey and southeastern North Carolina; and in the Black Creek-Matawan aquifer in east-central New Jersey and east-central North Carolina. Conversely, declines were least severe in the regional Upper Chesapeake aquifer during this period. In the Southeastern Coastal Plain, declines of more than 100 ft in the Chattahoochee River aquifer occurred in eastern South Carolina and in southwestern

A Simple, Inexpensive Water-Leveling Device for Ultramicrotomy.

ERIC Educational Resources Information Center

Brooks, Austin E.

1978-01-01

Describes a device for maintaining the proper water level in knife boats during ultramicrotomy. Water levels in troughs are adjusted rapidly and precisely during the cutting process. Illustrations are included. (Author/MA)

Observed cloud reflectivities and liquid water paths: An update

NASA Technical Reports Server (NTRS)

Coakley, James A., Jr.; Snider, Jack B.

1990-01-01

The FIRE microwave radiometer observations of liquid water path from San Nicolas Island and simultaneous NOAA AVHRR observations of cloud reflectivity were used to test a relationship between cloud liquid water path and cloud reflectivity that is often used in general circulation climate models (Stephens, 1978). The results of attempts to improve the data analysis which was described at the previous FIRE Science Team Workshop and elsewhere (Coakley and Snider, 1989) are reported. The improvements included the analysis of additional satellite passes over San Nicolas and sensitivity studies to estimate the effects on the observed reflectivities due to: (1) nonzero surface reflectivities beneath the clouds; (2) the anisotropy of the reflected radiances observed by the AVHRR; (3) small scale spatial structure in the liquid water path; and (4) adjustments to the calibration of AVHRR.

Ground observations and remote sensing data for integrated modelisation of water budget in the Merguellil catchment, Tunisia

NASA Astrophysics Data System (ADS)

Mougenot, Bernard

2016-04-01

The Mediterranean region is affected by water scarcity. Some countries as Tunisia reached the limit of 550 m3/year/capita due overexploitation of low water resources for irrigation, domestic uses and industry. A lot of programs aim to evaluate strategies to improve water consumption at regional level. In central Tunisia, on the Merguellil catchment, we develop integrated water resources modelisations based on social investigations, ground observations and remote sensing data. The main objective is to close the water budget at regional level and to estimate irrigation and water pumping to test scenarios with endusers. Our works benefit from French, bilateral and European projects (ANR, MISTRALS/SICMed, FP6, FP7…), GMES/GEOLAND-ESA) and also network projects as JECAM and AERONET, where the Merguellil site is a reference. This site has specific characteristics associating irrigated and rainfed crops mixing cereals, market gardening and orchards and will be proposed as a new environmental observing system connected to the OMERE, TENSIFT and OSR systems respectively in Tunisia, Morocco and France. We show here an original and large set of ground and remote sensing data mainly acquired from 2008 to present to be used for calibration/validation of water budget processes and integrated models for present and scenarios: - Ground data: meteorological stations, water budget at local scale: fluxes tower, soil fluxes, soil and surface temperature, soil moisture, drainage, flow, water level in lakes, aquifer, vegetation parameters on selected fieds/month (LAI, height, biomass, yield), land cover: 3 times/year, bare soil roughness, irrigation and pumping estimations, soil texture. - Remote sensing data: remote sensing products from multi-platform (MODIS, SPOT, LANDSAT, ASTER, PLEIADES, ASAR, COSMO-SkyMed, TerraSAR X…), multi-wavelength (solar, micro-wave and thermal) and multi-resolution (0.5 meters to 1 km). Ground observations are used (1) to calibrate soil

Geographical distribution of drinking-water with high iodine level and association between high iodine level in drinking-water and goitre: a Chinese national investigation.

PubMed

Shen, Hongmei; Liu, Shoujun; Sun, Dianjun; Zhang, Shubin; Su, Xiaohui; Shen, Yanfeng; Han, Hepeng

2011-07-01

Excessive iodine intake can cause thyroid function disorders as can be caused by iodine deficiency. There are many people residing in areas with high iodine levels in drinking-water in China. The main aim of the present study was to map the geographical distribution of drinking-water with high iodine level in China and to determine the relationship between high iodine level in drinking-water and goitre prevalence. Iodine in drinking-water was measured in 1978 towns of eleven provinces in China, with a total of 28,857 water samples. We randomly selected children of 8-10 years old, examined the presence of goitre and measured their urinary iodine in 299 towns of nine provinces. Of the 1978 towns studied, 488 had iodine levels between 150 and 300 μg/l in drinking-water, and in 246 towns, the iodine level was >300 μg/l. These towns are mainly distributed along the original Yellow River flood areas, the second largest river in China. Of the 56 751 children examined, goitre prevalence was 6.3 % in the areas with drinking-water iodine levels of 150-300 μg/l and 11.0 % in the areas with drinking-water iodine >300 μg/l. Goitre prevalence increased with water and urinary iodine levels. For children with urinary iodine >1500 μg/l, goitre prevalence was 3.69 times higher than that for those with urinary iodine levels of 100-199 μg/l. The present study suggests that drinking-water with high iodine levels is distributed in eleven provinces of China. Goitre becomes more prevalent with the increase in iodine level in drinking-water. Therefore, it becomes important to prevent goitre through stopping the provision of iodised salt and providing normal drinking-water iodine through pipelines in these areas in China.

Examining global extreme sea level variations on the coast from in-situ and remote observations

NASA Astrophysics Data System (ADS)

Menendez, Melisa; Benkler, Anna S.

2017-04-01

The estimation of extreme water level values on the coast is a requirement for a wide range of engineering and coastal management applications. In addition, climate variations of extreme sea levels on the coastal area result from a complex interacting of oceanic, atmospheric and terrestrial processes across a wide range of spatial and temporal scales. In this study, variations of extreme sea level return values are investigated from two available sources of information: in-situ tide-gauge records and satellite altimetry data. Long time series of sea level from tide-gauge records are the most valuable observations since they directly measure water level in a specific coastal location. They have however a number of sources of in-homogeneities that may affect the climate description of extremes when this data source is used. Among others, the presence of gaps, historical time in-homogeneities and jumps in the mean sea level signal are factors that can provide uncertainty in the characterization of the extreme sea level behaviour. Moreover, long records from tide-gauges are sparse and there are many coastal areas worldwide without in-situ available information. On the other hand, with the accumulating altimeter records of several satellite missions from the 1990s, approaching 25 recorded years at the time of writing, it is becoming possible the analysis of extreme sea level events from this data source. Aside the well-known issue of altimeter measurements very close to the coast (mainly due to corruption by land, wet troposphere path delay errors and local tide effects on the coastal area), there are other aspects that have to be considered when sea surface height values estimated from satellite are going to be used in a statistical extreme model, such as the use of a multi-mission product to get long observed periods and the selection of the maxima sample, since altimeter observations do not provide values uniform in time and space. Here, we have compared the extreme

Measuring water level in rivers and lakes from lightweight Unmanned Aerial Vehicles

NASA Astrophysics Data System (ADS)

Bandini, Filippo; Jakobsen, Jakob; Olesen, Daniel; Reyna-Gutierrez, Jose Antonio; Bauer-Gottwein, Peter

2017-05-01

The assessment of hydrologic dynamics in rivers, lakes, reservoirs and wetlands requires measurements of water level, its temporal and spatial derivatives, and the extent and dynamics of open water surfaces. Motivated by the declining number of ground-based measurement stations, research efforts have been devoted to the retrieval of these hydraulic properties from spaceborne platforms in the past few decades. However, due to coarse spatial and temporal resolutions, spaceborne missions have several limitations when assessing the water level of terrestrial surface water bodies and determining complex water dynamics. Unmanned Aerial Vehicles (UAVs) can fill the gap between spaceborne and ground-based observations, and provide high spatial resolution and dense temporal coverage data, in quick turn-around time, using flexible payload design. This study focused on categorizing and testing sensors, which comply with the weight constraint of small UAVs (around 1.5 kg), capable of measuring the range to water surface. Subtracting the measured range from the vertical position retrieved by the onboard Global Navigation Satellite System (GNSS) receiver, we can determine the water level (orthometric height). Three different ranging payloads, which consisted of a radar, a sonar and an in-house developed camera-based laser distance sensor (CLDS), have been evaluated in terms of accuracy, precision, maximum ranging distance and beam divergence. After numerous flights, the relative accuracy of the overall system was estimated. A ranging accuracy better than 0.5% of the range and a maximum ranging distance of 60 m were achieved with the radar. The CLDS showed the lowest beam divergence, which is required to avoid contamination of the signal from interfering surroundings for narrow fields of view. With the GNSS system delivering a relative vertical accuracy better than 3-5 cm, water level can be retrieved with an overall accuracy better than 5-7 cm.

Future extreme water levels and floodplains in Gironde Estuary considering climate change

NASA Astrophysics Data System (ADS)

Laborie, V.; Hissel, F.; Sergent, P.

2012-04-01

Within THESEUS European project, an overflowing model of Gironde Estuary has been used to evaluate future surge levels at Le Verdon and future water levels at 6 specific sites of the estuary : le Verdon, Richard, Laména, Pauillac, Le Marquis and Bordeaux. It was then used to study the evolution of floodplains' location and areas towards 2100 in the entire Estuary. In this study, no breaching and no modification in the elevation of the dike was considered. The model was fed by several data sources : wind fields at Royan and Mérignac interpolated from the grid of the European Climatolologic Model CLM/SGA, a tide signal at Le Verdon, the discharges of Garonne (at La Réole), the Dordogne (at Pessac) and Isle (at Libourne). A simplified mathematical model of surge levels has been adjusted at Le Verdon with 10 surge storms and by using wind and pressure fields given by CLM/SGA. This adjustment was led so that the statistical analysis of the global signal at Le Verdon gives the same quantiles as the same analysis driven on maregraphic observations for the period [1960 ; 2000]. The assumption used for sea level rise was the pessimistic one of the French national institute for climate change: 60 cm in 2100. The model was then used to study the evolution of extreme water levels towards 2100. The analysis of surge levels at Le Verdon shows a decrease in quantiles which is coherent with the analysis of climatologic fields. The analysis of water levels shows that the increase in mean water levels quantiles represents only a part of sea level rise in Gironde Estuary. Moreover this effect seems to decrease from the maritime limit of the model towards upstream. Concerning floodplains, those corresponding to return periods from 2 to 100 years for present conditions and 3 slices [2010; 2039], [2040; 2069] and [2070; 2099] have been mapped for 3 areas in Gironde Estuary : around Le Verdon, at the confluence between Garonne and Dordogne, and near Bordeaux. Concerning the evolution

Regional water table (2004) and water-level changes in the Mojave River and Morongo ground-water basins, Southwestern Mojave Desert, California

USGS Publications Warehouse

Stamos, Christina L.; Huff, Julia A.; Predmore, Steven K.; Clark, Dennis A.

2004-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During March and April 2004, the U.S. Geological Survey and other agencies made almost 900 water-level measurements in about 740 wells in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with historical data, changes in ground-water levels. A water-level contour map was drawn using data from 500 wells, providing coverage for most of the basins. In addition, 26 long-term (as much as 74 years) hydrographs were constructed which show water-level conditions throughout the basins, 9 short-term (1992 to 2004) hydrographs were constructed which show the effects of recharge and discharge along the Mojave River, and a water-level-change map was compiled to compare 2002 and 2004 water levels throughout the basins. The water-level change data show that in the Mojave River ground-water basin, more than one half (102) of the wells had water-level declines of 0.5 ft or more and almost one fifth (32) of the wells had declines greater than 5 ft. between 2002 and 2004. The water-level change data also show that about one tenth (17) of the wells compared in the Mojave River ground-water basin had water level increases of 0.5 ft or more. Most of the water-level increases were the result of stormflow in the Mojave River during March 2004, which resulted in recharge to wells in the floodplain aquifer mainly along the river in the Alto subarea and the Transition zone, and along the

Water-level changes induced by local and distant earthquakes at Long Valley caldera, California

USGS Publications Warehouse

Roeloffs, Evelyn A.; Sneed, Michelle; Galloway, Devin L.; Sorey, Michael L.; Farrar, Christopher D.; Howle, James F.; Hughes, J.

2003-01-01

small to be detected by the two-color electronic distance-measuring network. Opening-mode displacement in the south moat, inferred to have followed a M4.9 earthquake on November 22, 1997, could also create extensional strain on the dome and lead to water-level changes similar to those following dome inflation. Contractional strain that could account for earthquake-induced water-level rises at the CW-3 well is inconsistent with geodetic observations. We instead attribute these water-level rises to diffusion of elevated fluid pressure localized in the south moat thermal aquifer. For hydraulic diffusivities appropriate to the upper few hundred meters at Long Valley, an influx of material at temperatures of 300°C can thermally generate pressure of 6 m of water or more, an order of magnitude larger than needed to account for the CW-3 water-level rises. If magma or hot aqueous fluid rises to within 1 km of the surface in the eastern part of the south moat, then hydraulic diffusivities are high enough to allow fluid pressure to propagate to CW-3 on the time scale observed. The data indicate that seismic waves from large distant earthquakes can stimulate upward movement of fluid in the hydrothermal system at Long Valley.

Ground reaction forces in shallow water running are affected by immersion level, running speed and gender.

PubMed

Haupenthal, Alessandro; Fontana, Heiliane de Brito; Ruschel, Caroline; dos Santos, Daniela Pacheco; Roesler, Helio

2013-07-01

To analyze the effect of depth of immersion, running speed and gender on ground reaction forces during water running. Controlled laboratory study. Twenty adults (ten male and ten female) participated by running at two levels of immersion (hip and chest) and two speed conditions (slow and fast). Data were collected using an underwater force platform. The following variables were analyzed: vertical force peak (Fy), loading rate (LR) and anterior force peak (Fx anterior). Three-factor mixed ANOVA was used to analyze data. Significant effects of immersion level, speed and gender on Fy were observed, without interaction between factors. Fy was greater when females ran fast at the hip level. There was a significant increase in LR with a reduction in the level of immersion regardless of the speed and gender. No effect of speed or gender on LR was observed. Regarding Fx anterior, significant interaction between speed and immersion level was found: in the slow condition, participants presented greater values at chest immersion, whereas, during the fast running condition, greater values were observed at hip level. The effect of gender was only significant during fast water running, with Fx anterior being greater in the men group. Increasing speed raised Fx anterior significantly irrespective of the level of immersion and gender. The magnitude of ground reaction forces during shallow water running are affected by immersion level, running speed and gender and, for this reason, these factors should be taken into account during exercise prescription. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Observations of wave transformation over a fringing coral reef and the importance of low-frequency waves and offshore water levels to runup, overwash, and coastal flooding

NASA Astrophysics Data System (ADS)

Cheriton, Olivia M.; Storlazzi, Curt D.; Rosenberger, Kurt J.

2016-05-01

Many low-lying tropical islands are susceptible to sea level rise and often subjected to overwash and flooding during large wave events. To quantify wave dynamics and wave-driven water levels on fringing coral reefs, a 5 month deployment of wave gauges and a current meter was conducted across two shore-normal transects on Roi-Namur Island in the Republic of the Marshall Islands. These observations captured two large wave events that had waves with maximum heights greater than 6 m with peak periods of 16 s over the fore reef. The larger event coincided with a peak spring tide, leading to energetic, highly skewed infragravity (0.04-0.004 Hz) and very low frequency (0.004-0.001 Hz) waves at the shoreline, which reached heights of 1.0 and 0.7 m, respectively. Water surface elevations, combined with wave runup, reached 3.7 m above the reef bed at the innermost reef flat adjacent to the toe of the beach, resulting in flooding of inland areas. This overwash occurred during a 3 h time window that coincided with high tide and maximum low-frequency reef flat wave heights. The relatively low-relief characteristics of this narrow reef flat may further drive shoreline amplification of low-frequency waves due to resonance modes. These results (1) demonstrate how the coupling of high offshore water levels with low-frequency reef flat wave energetics can lead to large impacts along fringing reef-lined shorelines, such as island overwash, and (2) lend support to the hypothesis that predicted higher sea levels will lead to more frequent occurrences of these extreme events, negatively impacting coastal resources and infrastructure.

Observations of wave transformation over a fringing coral reef and the importance of low-frequency waves and offshore water levels to runup, overwash, and coastal flooding

USGS Publications Warehouse

Cheriton, Olivia; Storlazzi, Curt; Rosenberger, Kurt

2016-01-01

Many low-lying tropical islands are susceptible to sea level rise and often subjected to overwash and flooding during large wave events. To quantify wave dynamics and wave-driven water levels on fringing coral reefs, a 5 month deployment of wave gauges and a current meter was conducted across two shore-normal transects on Roi-Namur Island in the Republic of the Marshall Islands. These observations captured two large wave events that had waves with maximum heights greater than 6 m with peak periods of 16 s over the fore reef. The larger event coincided with a peak spring tide, leading to energetic, highly skewed infragravity (0.04–0.004 Hz) and very low frequency (0.004–0.001 Hz) waves at the shoreline, which reached heights of 1.0 and 0.7 m, respectively. Water surface elevations, combined with wave runup, reached 3.7 m above the reef bed at the innermost reef flat adjacent to the toe of the beach, resulting in flooding of inland areas. This overwash occurred during a 3 h time window that coincided with high tide and maximum low-frequency reef flat wave heights. The relatively low-relief characteristics of this narrow reef flat may further drive shoreline amplification of low-frequency waves due to resonance modes. These results (1) demonstrate how the coupling of high offshore water levels with low-frequency reef flat wave energetics can lead to large impacts along fringing reef-lined shorelines, such as island overwash, and (2) lend support to the hypothesis that predicted higher sea levels will lead to more frequent occurrences of these extreme events, negatively impacting coastal resources and infrastructure.

Water-quality and ground-water-level data, Bernalillo County, central New Mexico, 1995

USGS Publications Warehouse

Rankin, D.R.

1996-01-01

Water-quality and ground-water-level data were collected in two areas of eastern Bernalillo County in central New Mexico between March and July of 1995. Fifty-one wells, two springs, and the Ojo Grande Acequia in the east mountain area of Bernalillo County and nine wells in the northeast area of the city of Albuquerque were sampled. The water samples were analyzed for selected nutrient species; total organic carbon; major dissolved constituents; dissolved arsenic, boron, iron, and manganese; and methylene blue active substances. Analytical results were used to compute hardness, sodium adsorption ratio, and dissolved solids. Specific conductance, pH, temperature, and alkalinity were measured in the field at the time of sample collection. Ground- water-level and well-depth measurements were made at the time of sample collection when possible. Water-quality data, ground- water-level data, and well-depth data are presented in tabular form.

Sustained water-level changes caused by damage and compaction induced by teleseismic earthquakes

NASA Astrophysics Data System (ADS)

Shalev, Eyal; Kurzon, Ittai; Doan, Mai-Linh; Lyakhovsky, Vladimir

2016-07-01

Sustained water-level increase and decrease induced by distant earthquakes were observed in two wells, Gomè 1 and Meizar 1 in Israel. The Gomè 1 well is located within a damage zone of a major fault zone, and Meizar 1 is relatively far from a fault. The monitored pressure change in both wells shows significant water-level oscillations and sustained water-level changes in response to the passage of the seismic waves. The sustained water-level changes include short-term (minutes) undrained behavior and longer-period (hours and days) drained behavior associated with groundwater flow. We model the short-term undrained response of water pressure oscillations and sustained change to the distant 2013 Mw 7.7 Balochistan earthquake by nonlinear elastic behavior of damaged rocks, accounting for small wave-induced compaction and damage accumulation. We suggest that the rocks are close to failure in both locations and strain oscillations produced by the passing seismic waves periodically push the rock above the yield cap, creating compaction when volumetric strain increases and damage when shear strain increases. Compaction increases pore pressure, whereas damage accumulation decreases pore pressure by fracture dilation. The dominant process depends on the properties of the rock. For highly damaged rocks, dilatancy is dominant and a sustained pressure decrease is expected. For low-damage rocks, compaction is the dominant process creating sustained water-level increase. We calculate damage and porosity changes associated to the Balochistan earthquake in both wells and quantify damage accumulation and compaction during the passage of the seismic waves.

Ground-water levels in Huron County, Michigan, 2002-03

USGS Publications Warehouse

Weaver, T.L.; Blumer, S.P.; Crowley, S.L.

2008-01-01

In 1990, the U.S. Geological Survey (USGS) completed a study of the hydrogeology of Huron County, Michigan (Sweat, 1991). In 1993, Huron County and the USGS entered into a continuing agreement to collect water-level altitudes (hereafter referred to as water levels) at selected wells throughout Huron County. As part of the agreement, USGS has operated four continuous water-level recorders, installed from 1988 to 1991 on wells in Bingham, Fairhaven, Grant, and Lake Townships (fig. 1) and summarized the data collected in an annual or bi-annual report. The agreement was altered in 2003, and beginning January 1, 2004, only the wells in Fairhaven and Lake Townships will have continuous water-level recorders, while the wells in Grant and Bingham Townships will revert to quarterly measurement status. USGS has also provided training for County or Huron Conservation District personnel to measure the water level, on a quarterly basis, in 23 wells. USGS personnel regularly accompany County or Huron Conservation District personnel to provide a quality assurance/quality control check of all measurements being made. Water-level data collected from the 23 quarterly-measured wells is also summarized in the annual or bi-annual report. In 1998, the USGS also completed a temporal and spatial analysis of the monitoring well network in Huron County (Holtschlag and Sweat, 1998).The altitude of Lake Huron and precipitation are good indicators of general climatic conditions and, therefore, provide an environmental context for groundwater levels in Huron County. Figure 2 shows the mean-monthly water-level altitude of Lake Huron, averaged from measurements made by the U.S. Army Corps of Engineers at sites near Essexville and Harbor Beach, and monthly precipitation measured in Bad Axe (National Oceanic and Atmospheric Administration [NOAA], 2002-04; Danny Costello, NOAA hydrologist, written commun., 2003-04). In March 2003, a new low-water level for the period of this study was measured in

Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

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

Susko, Michele L.; Bloom, Michael S., E-mail: mbloom@albany.edu; Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnairemore » and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. �

Development and evaluation of a water level proportional water sampler

NASA Astrophysics Data System (ADS)

Schneider, P.; Lange, A.; Doppler, T.

2013-12-01

We developed and adapted a new type of sampler for time-integrated, water level proportional water quality sampling (e.g. nutrients, contaminants and stable isotopes). Our samplers are designed for sampling small to mid-size streams based on the law of Hagen-Poiseuille, where a capillary (or a valve) limits the sampling aliquot by reducing the air flux out of a submersed plastic (HDPE) sampling container. They are good alternatives to battery-operated automated water samplers when working in remote areas, or at streams that are characterized by pronounced daily discharge variations such as glacier streams. We evaluated our samplers against standard automated water samplers (ISCO 2900 and ISCO 6712) during the snowmelt in the Black Forest and the Alps and tested them in remote glacial catchments in Iceland, Switzerland and Kyrgyzstan. The results clearly showed that our samplers are an adequate tool for time-integrated, water level proportional water sampling at remote test sites, as they do not need batteries, are relatively inexpensive, lightweight, and compact. They are well suited for headwater streams - especially when sampling for stable isotopes - as the sampled water is perfectly protected against evaporation. Moreover, our samplers have a reduced risk of icing in cold environments, as they are installed submersed in water, whereas automated samplers (typically installed outside the stream) may get clogged due to icing of hoses. Based on this study, we find these samplers to be an adequate replacement for automated samplers when time-integrated sampling or solute load estimates are the main monitoring tasks.

Using Sealed Wells to Measure Water Levels Beneath Streams and Floodplains.

PubMed

Noorduijn, Saskia L; Cook, Peter G; Wood, Cameron; White, Nick

2015-01-01

The design of wells beneath streams and floodplains has often employed with tall standpipes to prevent incursion of surface water into the well during flood events. Here, an approach has been presented to minimise the infrastructure demands in these environments by sealing the well top (e.g., prevent water entering the well) and monitor the total pressure in the water column using an absolute (non-vented) pressure transducer. The sealed well design was tested using a laboratory experiment where the total pressure responses were monitored in both an unsealed and sealed well, while the water level was varied. It is observed that, whether the well is sealed or not, the total pressure at a given depth in the aquifer will be equal to that within the well. This indicates that the sealed well design is a viable alternative to tall standpipes and also facilitates installation of wells beneath streams and floodplains. © 2015, National Ground Water Association.

Status of Water Levels and Selected Water-Quality Conditions in the Sparta-Memphis Aquifer in Arkansas and the Status of Water Levels in the Sparta Aquifer in Louisiana, Spring 2005

USGS Publications Warehouse

Schrader, T.P.; Jones, J.S.

2007-01-01

The U.S. Geological Survey in cooperation with the Arkansas Natural Resources Commission, the Arkansas Geological Commission, and the Louisiana Department of Transportation and Development has monitored water levels in the Sparta Sand of Claiborne Group and Memphis Sand of Claiborne Group since the 1920's. Ground-water withdrawals have increased while water levels have declined since monitoring was initiated. This report has been produced to describe ground-water levels in the aquifers in the Sparta Sand and Memphis Sand and provide information for the management of this valuable resource. The 2005 potentiometric-surface map of the aquifers in the Sparta Sand and Memphis Sand was constructed using water-level data collected in 333 wells in Arkansas and 120 wells in Louisiana during the spring of 2005. The highest water-level altitude measured in Arkansas was 327 feet above National Geodetic Vertical Datum of 1929 located in Grant County in the outcrop at the western boundary of the study area; the lowest water-level altitude was 189 feet below National Geodetic Vertical Datum of 1929 in Union County. The highest water-level altitude measured in Louisiana was 246 feet above National Geodetic Vertical Datum of 1929 located in Bossier Parish in the outcrop area near the western boundary of the study area; the lowest water-level altitude was 226 feet below National Geodetic Vertical Datum of 1929 in central Ouachita Parish. Three large depressions centered in Columbia, Jefferson, and Union Counties in Arkansas are the result of large withdrawals for industrial and public supplies. In Louisiana, three major pumping centers are in Ouachita, Jackson, and Lincoln Parishes. Water withdrawals from these major pumping centers primarily is used for industrial and public-supply purposes. Withdrawals from Ouachita and Lincoln Parishes and Union County, Arkansas, primarily for industrial purposes, have caused the resulting cones of depression to coalesce so that the -40 foot

MIRO Observation of Comet C/2002 T7 (LINEAR) Water Line Spectrum

NASA Technical Reports Server (NTRS)

Lee, Seungwon; Frerking, Margaret; Hofstadter, Mark; Gulkis, Samuel; von Allmen, Paul; Crovisier, Jaques; Biver, Nicholas; Bockelee-Morvan, Dominique

2011-01-01

Comet C/2002 T7 (LINEAR) was observed with the Microwave Instrument for Rosetta Orbiter (MIRO) on April 30, 2004, between 5 hr and 16 hr UT. The comet was 0.63AU distance from the Sun and 0.68AU distance from the MIRO telescope at the time of the observations. The water line involving the two lowest rotational levels at 556.936 GHz is observed at 557.070 GHz due to a large Doppler frequency shift. The detected water line spectrum is interpreted using a non local thermal equilibrium (Non-LTE) molecular excitation and radiative transfer model. Several synthetic spectra are calculated with various coma profiles that are plausible for the comet at the time of observations. The coma profile is modeled with three characteristic parameters: outgassing rate, a constant expansion velocity, and a constant gas temperature. The model calculation result shows that for the distant line observation where contributions from a large coma space is averaged, the combination of the outgassing rate and the gas expansion velocity determines the line shape while the gas temperature has a negligible effect. The comparison between the calculated spectra and the MIRO measured spectrum suggests that the outgassing rate of the comet is about 2.0x1029 molecules/second and its gas expansion velocity about 1.2 km/s at the time of the observations.

Long-Term Ground-Water Levels and Transmissivity in the Blackstone River Basin, Northern Rhode Island

USGS Publications Warehouse

Eggleston, Jack R.; Church, Peter E.; Barbaro, Jeffrey R.

2007-01-01

Ground water provides about 7.7 million gallons per day, or 28 percent of total water use in the Rhode Island part of the Blackstone River Basin. Primary aquifers in the basin are stratified glacial deposits, composed mostly of sand and gravel along valley bottoms. The ground-water and surface-water system in the Blackstone River Basin is under stress due to population growth, out-of-basin water transfers, industrialization, and changing land-use patterns. Streamflow periodically drops below the Aquatic Base Flow standard, and ground-water withdrawals add to stress on aquatic habitat during low-flow periods. Existing hydrogeologic data were reviewed to examine historical water-level trends and to generate contour maps of water-table altitudes and transmissivity of the sand and gravel aquifer in the Blackstone River Basin in Rhode Island. On the basis of data from four long-term observation wells, water levels appear to have risen slightly in the study area during the past 55 years. Analysis of available data indicates that increased rainfall during the same period is a likely contributor to the water-level rise. Spatial patterns of transmissivity are shown over larger areas and have been refined on the basis of more detailed data coverage as compared to previous mapping studies.

Toward a Global Water Quality Observing and Forecasting System

EPA Science Inventory

The Group on Earth Observations (GEO) Coastal and Inland Water Quality Working Group held a Water Quality Summit at the World Meteorological Organization (WMO) in Geneva, Switzerland April 20 to 22, 2015. The goal was to define specific water quality component requirements and de...

Ground-water levels in Huron County, Michigan, 2006-07

USGS Publications Warehouse

Weaver, T.L.; Blumer, S.P.; Fuller, L.M.

2008-01-01

In 1990, the U.S. Geological Survey (USGS) completed a study of the hydrogeology of Huron County, Michigan (Sweat, 1991). In 1993, Huron County and the USGS entered into a continuing agreement to measure water levels at selected wells throughout Huron County. As part of the agreement, USGS initially operated four continuous water-level recorders, installed from 1988 to 1991 on wells in Bingham (H5r), Fairhaven (H9r), Grant (H2r), and Lake Townships (H25Ar) and summarized the data collected in an annual or bi-annual report (fig. 1). The agreement was altered in 2003, and beginning January 1, 2004, only wells H9r and H25Ar retained continuous water-level recorders, while wells H2r and H5r reverted to quarterly or periodic measurement status due to budget constraints. The decision of which two wells to discontinue was based on an analysis of the intrinsic value to Huron County of data from each well. Well H2r was selected for periodic measurement at that time because it is completed in the glacial aquifer, which is absent in much of Huron County and well H5r, which is completed in the Marshall aquifer, was selected because the water level in the well is often perturbed as a result of pumpage from nearby production wells and does not always reflect baseline conditions within the aquifer. USGS also has provided training for County or Huron Conservation District personnel to measure the water level in 24 of the wells on a quarterly basis. USGS personnel accompany County or Huron Conservation District personnel on a semi-annual basis to provide a quality assurance/quality control check of all measurements being made. Water-level data collected from the wells is summarized in an annual or bi-annual report. The altitude of Lake Huron and precipitation are good indicators of general climatic conditions and, therefore, provide an environmental context for groundwater levels in Huron County. Figure 2 shows the meanmonthly water-level altitude of Lake Huron, averaged from

Valence holes observed in nanodiamonds dispersed in water

NASA Astrophysics Data System (ADS)

Petit, Tristan; Pflüger, Mika; Tolksdorf, Daniel; Xiao, Jie; Aziz, Emad F.

2015-02-01

Colloidal dispersion is essential for most nanodiamond applications, but its influence on nanodiamond electronic properties remains unknown. Here we have probed the electronic structure of oxidized detonation nanodiamonds dispersed in water by using soft X-ray absorption and emission spectroscopies at the carbon and oxygen K edges. Upon dispersion in water, the π* transitions from sp2-hybridized carbon disappear, and holes in the valence band are observed.Colloidal dispersion is essential for most nanodiamond applications, but its influence on nanodiamond electronic properties remains unknown. Here we have probed the electronic structure of oxidized detonation nanodiamonds dispersed in water by using soft X-ray absorption and emission spectroscopies at the carbon and oxygen K edges. Upon dispersion in water, the π* transitions from sp2-hybridized carbon disappear, and holes in the valence band are observed. Electronic supplementary information (ESI) available: Experimental methods, details on XAS/XES normalization and background correction procedures. See DOI: 10.1039/c4nr06639a

NASA Remote Sensing Observations for Water Resource and Infrastructure Management

NASA Astrophysics Data System (ADS)

Granger, S. L.; Armstrong, L.; Farr, T.; Geller, G.; Heath, E.; Hyon, J.; Lavoie, S.; McDonald, K.; Realmuto, V.; Stough, T.; Szana, K.

2008-12-01

Decision support tools employed by water resource and infrastructure managers often utilize data products obtained from local sources or national/regional databases of historic surveys and observations. Incorporation of data from these sources can be laborious and time consuming as new products must be identified, cleaned and archived for each new study site. Adding remote sensing observations to the list of sources holds promise for a timely, consistent, global product to aid decision support at regional and global scales by providing global observations of geophysical parameters including soil moisture, precipitation, atmospheric temperature, derived evapotranspiration, and snow extent needed for hydrologic models and decision support tools. However, issues such as spatial and temporal resolution arise when attempting to integrate remote sensing observations into existing decision support tools. We are working to overcome these and other challenges through partnerships with water resource managers, tool developers and other stakeholders. We are developing a new data processing framework, enabled by a core GIS server, to seamlessly pull together observations from disparate sources for synthesis into information products and visualizations useful to the water resources community. A case study approach is being taken to develop the system by working closely with water infrastructure and resource managers to integrate remote observations into infrastructure, hydrologic and water resource decision tools. We present the results of a case study utilizing observations from the PALS aircraft instrument as a proxy for NASA's upcoming Soil Moisture Active Passive (SMAP) mission and an existing commercial decision support tool.

Ground-water level data for North Carolina, 1988-90

USGS Publications Warehouse

Strickland, A.G.; Coble, R.W.; Edwards, L.A.; Pope, B.F.

1992-01-01

Continuous and periodic water-level measurements were made in 59 key wells throughout North Carolina. Additional measurements were made in 112 supplementary wells completed in Coastal Plain aquifers of the State. Changes in groundwater storage are shown in 3-year and 10-year hydrographs of selected wells in the State. The water table in the shallow aquifers was higher throughout most of 1989 and early 1990 than in 1988, indicating that these aquifers were sufficiently recharged by precipitation to replenish the late 1987-88 deficit in groundwater storage. Water levels in the heavily pumped Coastal Plain aquifers declined as a result of water being withdrawn from aquifer storage. Record low water levels were measured in 8 to 13 wells completed in the Castle Hayne aquifer and in 6 of 8 wells in the Peedee aquifer; the maximum annual declines during 1988-90 averaged 3.3 and 1.6 ft/yr, respectively, for these two aquifers. All wells in the Black Creek, upper Cape Fear, and lower Cape Fear aquifers had record low water levels during 1988-90, with maximum annual declines averaging 9.0, 2.2, and 2.6 ft/yr, respectively. Water levels in two of three wells in the Yorktown aquifer did not show a general downward trend during 1988-90, although water levels declined in the third well, reaching a record low in 1990. The effects of water withdrawals from major pumping centers in the North Carolina Coastal Plain are shown in potentiometric-surface maps of the Black Creek and lower Cape Fear aquifers.

Evaluation of water-level recovery, 1996-97 to 1999-2000, and comparison of 1999-2000 and 1972-73 water levels in Goleta Central Subbasin, Santa Barbara County, California

USGS Publications Warehouse

Densmore, Jill N.; Scrudato, Matthew C.; Houston, Ernest R.

2001-01-01

Ground-water levels were measured during January 1999-June 2000 to evaluate the rate of water-level recovery in the Goleta Central ground-water subbasin that has resulted from injection of about 2,225 acre-feet of surplus water for storage in the ground-water basin. Injection of surplus water was tabulated and compared with water-level rises since 1996 to evaluate the effectiveness of the recharge effort. Water levels have risen about 4 to 37 feet since 1996-97. A preliminary water budget was compiled to assess recharge and discharge in the basin, and it is estimated that total inflow exceeded total outflow during 1998-99 by about 2,844 to 7,518 acre-feet. In addition, water levels for 1999-2000 were compared with water levels for 1972-73 to determine if a 'drought buffer' exists. Water levels measured in two wells during January 1999-June 2000 exceeded January 1972-June 1973 levels. Water levels in the remaining wells measured during January 1999-June 2000 ranged from less than 1 foot to about 32 feet below 1972-73 water levels. In general, the largest water-level rise between 1996-97 and 1999-2000 was about 37 feet in the southeastern end of the basin; the rise was less than 4 feet in the western end of the basin and about 10 feet north of the Goleta Fault. Long-term hydrographs indicate that water levels have been recovering throughout the basin since the early 1990's.

Simulation of the effects of rainfall and groundwater use on historical lake water levels, groundwater levels, and spring flows in central Florida

USGS Publications Warehouse

O'Reilly, Andrew M.; Roehl, Edwin A.; Conrads, Paul; Daamen, Ruby C.; Petkewich, Matthew D.

2014-01-01

Mgal/d in 2000. The change in groundwater-use trend in the early 1980s and the following period of relatively slight trend is attributable to the concomitant effects of increasing public-supply withdrawals and decreasing use of water by the phosphate industry and agriculture. On the basis of available historical data and exploratory analyses, empirical lake water-level, groundwater-level, and spring-flow models were developed for 22 lakes, 23 wells, and 6 springs. Input time series consisting of various frequencies and frequency-band components of daily rainfall (1942 to 2008) and monthly total groundwater use (1957 to 2008) resulted in hybrid signal-decomposition artificial neural network models. The final models explained much of the variability in observed hydrologic data, with 43 of the 51 sites having coefficients of determination exceeding 0.6, and the models matched the magnitude of the observed data reasonably well, such that models for 32 of the 51 sites had root-mean-square errors less than 10 percent of the measured range of the data. The Central Florida Artificial Neural Network Decision Support System was developed to integrate historical databases and the 102 site-specific artificial neural network models, model controls, and model output into a spreadsheet application with a graphical user interface that allows the user to simulate scenarios of interest. Overall, the data-mining analyses indicate that the Floridan aquifer system in central Florida is a highly conductive, dynamic, open system that is strongly influenced by external forcing. The most important external forcing appears to be rainfall, which explains much of the multiyear cyclic variability and long-term downward trends observed in lake water levels, groundwater levels, and spring flows. For most sites, groundwater use explains less of the observed variability in water levels and flows than rainfall. Relative groundwater-use impacts are greater during droughts, however, and long-term trends

Quantification of umu genotoxicity level of urban river water.

PubMed

Kameya, T; Nagato, T; Nakagawa, K; Yamashita, D; Kobayashi, T; Fujie, K

2011-01-01

In recent years, the request of environmental safety management for carcinogenic substances, mutagenic substances and/or reproductive toxicity substances (CMR) has increased. This study focused on clarifying the genotoxicity level of environmental water and its release source by using the umu test provided in ISO13829. Although a genotoxicity index "induction ratio (IR)" is used in ISO13829, we normalised it to make it possible to compare various environmental water quantitatively to each other as a new index "genotoxic activity (GA=(IR-1)/Dose)". Sample water was collected and concentrated to 100 times or 1,000 times by a solid phase extraction method. As the test results, it was found that GA level in actual river water varied widely from less than the determination limit of 23 [1/L] to 1,100 [1/L] by quantitative comparison, and the value was also equivalent to more than 50 times the level of tap water. The GA level of household wastewater was not so high, but the levels of treated water from wastewater treatment plant (WTP) were from 220 [1/L] to 3,200 [1/L]. Raw sewage of some WTP shows high level genotoxicity. A part of genotoxicity substances, for example 50%, could be removed by conventional wastewater treatment, but it was not enough to reduce the water environmental load of genotoxicity.

Generalized water-level contours, September-October 2000 and March-April 2001, and long-term water-level changes, at the U.S. Air Force Plant 42 and vicinity, Palmdale, California

USGS Publications Warehouse

Christensen, Allen H.

2005-01-01

Historically, the U.S. Air Force Plant 42 has relied on ground water as the primary source of water owing, in large part, to the scarcity of surface water in the region. Groundwater withdrawal for municipal, industrial, and agricultural use has affected ground-water levels at U.S. Air Force Plant 42, and vicinity. A study to document changes in groundwater gradients and to present historical water-level data was completed by the U.S. Geological Survey in cooperation with the U.S. Air Force. This report presents historical water-level data, hydrographs, and generalized seasonal water-level and water-level contours for September?October 2000 and March?April 2001. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently water availability. During September?October 2000 and March?April 2001 the U.S. Geological Survey and other agencies made a total of 102 water-level measurements, 46 during September?October 2000 and 56 during March?April 2001. These data document recent conditions and, when compared with historical data, document changes in ground-water levels. Two water-level contour maps were drawn: the first depicts water-level conditions for September?October 2000 map and the second depicts water-level conditions for March?April 2001 map. In general, the water-level contour maps show water-level depressions formed as result of ground-water withdrawal. One hundred sixteen long-term hydrographs, using water-level data from 1915 through 2000, were constructed to show water-level trends in the area. The hydrographs indicate that water-level decline occurred throughout the study area, with the greatest declines south of U.S. Air Force Plant 42.

Arsenic levels in drinking water and mortality of liver cancer in Taiwan.

PubMed

Lin, Hung-Jung; Sung, Tzu-I; Chen, Chi-Yi; Guo, How-Ran

2013-11-15

The carcinogenic effect of arsenic is well documented, but epidemiologic data on liver cancer were limited. To evaluate the dose-response relationship between arsenic in drinking water and mortality of liver cancer, we conducted a study in 138 villages in the southwest coast area of Taiwan. We assessed arsenic levels in drinking water using data from a survey conducted by the government and reviewed death certificates from 1971 to 1990 to identify liver cancer cases. Using village as the unit, we conducted multi-variate regression analyses and then performed post hoc analyses to validate the findings. During the 20-year period, 802 male and 301 female mortality cases of liver cancer were identified. After adjusting for age, arsenic levels above 0.64 mg/L were associated with an increase in the liver cancer mortality in both genders, but no significant effect was observed for lower exposure categories. Post hoc analyses and a review of literature supported these findings. We concluded that exposures to high arsenic levels in drinking water are associated with the occurrence of liver cancer, but such an effect is not prominent at exposure levels lower than 0.64 mg/L. Copyright © 2013 Elsevier B.V. All rights reserved.

Subsidence at the Fairport Harbor Water Level Gauge

NASA Astrophysics Data System (ADS)

Conner, D. A.

2014-12-01

SUBSIDENCE AT THE FAIRPORT HARBOR WATER LEVEL GAUGE I will provide information on methods being used to monitor Lake Erie water levels and earth movement at Fairport Harbor, Ohio. Glacial Isostatic Adjustment (GIA) is responsible for vertical movement throughout the Great Lakes region. Fairport Harbor is also experiencing vertical movement due to salt mining, so the nearby water level gauge operated by the National Oceanic and Atmospheric Administration (NOAA) is affected by both GIA and mining. NOAA's National Geodetic Survey (NGS) defines and maintains the National Spatial Reference System (NSRS). The NSRS includes a network of permanently marked points; a consistent, accurate, and up-to-date national shoreline; a network of Continuously Operating Reference Stations (CORS) which supports three-dimensional positioning activities; and a set of accurate models describing dynamic, geophysical processes that affect spatial measurements. The NSRS provides the spatial reference foundation for transportation, mapping, charting and a multitude of scientific and engineering applications. Fundamental elements of geodetic infrastructure include GPS CORS (3-D), water level and tide gauges (height) and a system of vertical bench marks (height). When two or more of these elements converge they may provide an independent determination of position and vertical stability as is the case here at the Fairport Harbor water level gauge. Analysis of GPS, leveling and water level data reveal that this gauge is subsiding at about 2-3 mm/year, independent of the effects of GIA. Analysis of data from the nearby OHLA GPS CORS shows it subsiding at about 4 mm/yr, four times faster than expected due to GIA alone. A long history of salt mine activity in the area is known to geologists but it came as a surprise to other scientists.

Ground-Water Levels in Huron County, Michigan, 2004-05

USGS Publications Warehouse

Weaver, T.L.; Crowley, S.L.; Blumer, S.P.

2006-01-01

In 1990, the U.S. Geological Survey (USGS) completed a study of the hydrogeology of Huron County, Michigan (Sweat, 1991). In 1993, Huron County and the USGS entered into a continuing agreement to measure water levels at selected wells throughout Huron County. As part of the agreement, USGS has operated four continuous water-level recorders, installed from 1988 to 1991 on wells in Bingham, Fairhaven, Grant, and Lake Townships (fig. 1) and summarized the data collected in an annual or bi-annual report. The agreement was altered in 2003, and beginning January 1, 2004, only the wells in Fairhaven and Lake Townships retained continuous waterlevel recorders, while the wells in Grant and Bingham Townships reverted primarily to periodic or quarterly measurement status. USGS also has provided training for County or Huron Conservation District personnel to measure the water level, on a quarterly basis, in 25 wells. USGS personnel regularly accompany County or Huron Conservation District personnel to provide a quality assurance/quality control check of all measurements being made. Water-level data collected from the 25 periodically or quarterly-measured wells is summarized in an annual or bi-annual report. In 1998, the USGS also completed a temporal and spatial analysis of the monitoring well network in Huron County (Holtschlag and Sweat, 1998).The altitude of Lake Huron and precipitation are good indicators of general climatic conditions and, therefore, provide an environmental context for ground-water levels in Huron County. Figure 2 shows the mean-monthly water-level altitude of Lake Huron, averaged from measurements made by the U.S. Army Corps of Engineers at sites near Essexville or Harbor Beach, or both (National Oceanic and Atmospheric Administration, 2003-05), and monthly precipitation measured in Bad Axe (National Oceanic and Atmospheric Administration, 2003-05). In March 2003, a new low-water level for the period from 1991 through 2005 was measured in Lake Huron

Water Resources Data for California, Water Year 1987. Volume 5. Ground-water Data for California

USGS Publications Warehouse

Lamb, C.E.; Fogelman, R.P.; Grillo, D.A.

1989-01-01

Water resources data for the 1987 water year for California consist of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 5 contains water levels for 786 observation wells and water-quality data for 168 observation wells. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

Water Resources Data for California, Water Year 1986. Volume 5. Ground-Water Data for California

USGS Publications Warehouse

Lamb, C.E.; Keeter, G.L.; Grillo, D.A.

1988-01-01

Water resources data for the 1986 water year for California consist of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 5 contains water levels for 765 observation wells and water-quality data for 174 observation wells. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

Climatic Implications of the Observed Temperature Dependence of the Liquid Water Path of Low Clouds in the Southern Great Plains

NASA Technical Reports Server (NTRS)

DelGenio, Anthony

1999-01-01

Satellite observations of low-level clouds have challenged the assumption that adiabatic liquid water content combined with constant physical thickness will lead to a negative cloud optics feedback in a decadal climate change. We explore the reasons for the satellite results using four years of surface remote sensing data from the Atmospheric Radiation Measurement Program Cloud and Radiation Testbed site in the Southern Great Plains of the United States. We find that low cloud liquid water path is approximately invariant with temperature in winter but decreases strongly with temperature in summer, consistent with the satellite inferences at this latitude. This behavior occurs because liquid water content shows no detectable temperature dependence while cloud physical thickness decreases with warming. Thinning of clouds with warming is observed on seasonal, synoptic, and diurnal time scales; it is most obvious in the warm sectors of baroclinic waves. Although cloud top is observed to slightly descend with warming, the primary cause of thinning, is the ascent of cloud base due to the reduction in surface relative humidity and the concomitant increase in the lifting condensation level of surface air. Low cloud liquid water path is not observed to be a continuous function of temperature. Rather, the behavior we observe is best explained as a transition in the frequency of occurrence of different boundary layer types. At cold temperatures, a mixture of stratified and convective boundary layers is observed, leading to a broad distribution of liquid water path values, while at warm temperatures, only convective boundary layers with small liquid water paths, some of them decoupled, are observed. Our results, combined with the earlier satellite inferences, imply that the commonly quoted 1.5C lower limit for the equilibrium global climate sensitivity to a doubling of CO2 which is based on models with near-adiabatic liquid water behavior and constant physical thickness

Climatic Implications of the Observed Temperature Dependence of the Liquid Water Path of Low Clouds in the Southern Great Plains

NASA Technical Reports Server (NTRS)

DelGenio, Anthony D.; Wolf, Audrey B.

1999-01-01

Satellite observations of low-level clouds have challenged the assumption that adiabatic liquid water content combined with constant physical thickness will lead to a negative cloud optics feedback in a decadal climate change. We explore the reasons for the satellite results using four years of surface remote sensing data from the Atmospheric Radiation Measurement Program Cloud and Radiation Testbed site in the Southern Great Plains of the United States. We find that low cloud liquid water path is approximately invariant with temperature in winter but decreases strongly with temperature in summer, consistent with the satellite inferences at this latitude. This behavior occurs because liquid water content shows no detectable temperature dependence while cloud physical thickness decreases with warming. Thinning of clouds with warming is observed on seasonal, synoptic, and diurnal time scales; it is most obvious in the warm sectors of baroclinic waves. Although cloud top is observed to slightly descend with warming, the primary cause of thinning is the ascent of cloud base due to the reduction in surface relative humidity and the concomitant increase in the lifting condensation level of surface air. Low cloud liquid water path is not observed to be a continuous function of temperature. Rather, the behavior we observe is best explained as a transition in the frequency of occurrence of different boundary layer types: At cold temperatures, a mixture of stratified and convective boundary layers is observed, leading to a broad distribution of liquid water path values, while at warm temperatures, only convective boundary layers with small liquid water paths, some of them decoupled, are observed. Our results, combined with the earlier satellite inferences, imply that the commonly quoted 1.50 C lower limit for the equilibrium global climate sensitivity to a doubling of CO2, which is based on models with near-adiabatic liquid water behavior and constant physical thickness

Experimental Observation of Dark Solitons on Water Surface

DTIC Science & Technology

2016-06-13

Experimental observation of dark solitons on water surface A. Chabchoub1,∗, O. Kimmoun2, H. Branger3, N. Hoffmann1, D. Proment4, M. Onorato4,5, and N...The shape and width of the soliton depend on the water depth, carrier frequency and the amplitude of the background wave. The experimental data...partic- ular, the governing equation describing the dynamics of weakly nonlinear and quasi -monochromatic waves prop- agating on the surface of water with

Optimization of water-level monitoring networks in the eastern Snake River Plain aquifer using a kriging-based genetic algorithm method

USGS Publications Warehouse

Fisher, Jason C.

2013-01-01

Long-term groundwater monitoring networks can provide essential information for the planning and management of water resources. Budget constraints in water resource management agencies often mean a reduction in the number of observation wells included in a monitoring network. A network design tool, distributed as an R package, was developed to determine which wells to exclude from a monitoring network because they add little or no beneficial information. A kriging-based genetic algorithm method was used to optimize the monitoring network. The algorithm was used to find the set of wells whose removal leads to the smallest increase in the weighted sum of the (1) mean standard error at all nodes in the kriging grid where the water table is estimated, (2) root-mean-squared-error between the measured and estimated water-level elevation at the removed sites, (3) mean standard deviation of measurements across time at the removed sites, and (4) mean measurement error of wells in the reduced network. The solution to the optimization problem (the best wells to retain in the monitoring network) depends on the total number of wells removed; this number is a management decision. The network design tool was applied to optimize two observation well networks monitoring the water table of the eastern Snake River Plain aquifer, Idaho; these networks include the 2008 Federal-State Cooperative water-level monitoring network (Co-op network) with 166 observation wells, and the 2008 U.S. Geological Survey-Idaho National Laboratory water-level monitoring network (USGS-INL network) with 171 wells. Each water-level monitoring network was optimized five times: by removing (1) 10, (2) 20, (3) 40, (4) 60, and (5) 80 observation wells from the original network. An examination of the trade-offs associated with changes in the number of wells to remove indicates that 20 wells can be removed from the Co-op network with a relatively small degradation of the estimated water table map, and 40 wells

Estimating Water Supply Arsenic Levels in the New England Bladder Cancer Study

PubMed Central

Freeman, Laura E. Beane; Lubin, Jay H.; Airola, Matthew S.; Baris, Dalsu; Ayotte, Joseph D.; Taylor, Anne; Paulu, Chris; Karagas, Margaret R.; Colt, Joanne; Ward, Mary H.; Huang, An-Tsun; Bress, William; Cherala, Sai; Silverman, Debra T.; Cantor, Kenneth P.

2011-01-01

Background: Ingestion of inorganic arsenic in drinking water is recognized as a cause of bladder cancer when levels are relatively high (≥ 150 µg/L). The epidemiologic evidence is less clear at the low-to-moderate concentrations typically observed in the United States. Accurate retrospective exposure assessment over a long time period is a major challenge in conducting epidemiologic studies of environmental factors and diseases with long latency, such as cancer. Objective: We estimated arsenic concentrations in the water supplies of 2,611 participants in a population-based case–control study in northern New England. Methods: Estimates covered the lifetimes of most study participants and were based on a combination of arsenic measurements at the homes of the participants and statistical modeling of arsenic concentrations in the water supply of both past and current homes. We assigned a residential water supply arsenic concentration for 165,138 (95%) of the total 173,361 lifetime exposure years (EYs) and a workplace water supply arsenic level for 85,195 EYs (86% of reported occupational years). Results: Three methods accounted for 93% of the residential estimates of arsenic concentration: direct measurement of water samples (27%; median, 0.3 µg/L; range, 0.1–11.5), statistical models of water utility measurement data (49%; median, 0.4 µg/L; range, 0.3–3.3), and statistical models of arsenic concentrations in wells using aquifers in New England (17%; median, 1.6 µg/L; range, 0.6–22.4). Conclusions: We used a different validation procedure for each of the three methods, and found our estimated levels to be comparable with available measured concentrations. This methodology allowed us to calculate potential drinking water exposure over long periods. PMID:21421449

Estimating water supply arsenic levels in the New England bladder cancer study

USGS Publications Warehouse

Nuckols, J.R.; Beane, Freeman L.E.; Lubin, J.H.; Airola, M.S.; Baris, D.; Ayotte, J.D.; Taylor, A.; Paulu, C.; Karagas, M.R.; Colt, J.; Ward, M.H.; Huang, A.-T.; Bress, W.; Cherala, S.; Silverman, D.T.; Cantor, K.P.

2011-01-01

Background: Ingestion of inorganic arsenic in drinking water is recognized as a cause of bladder cancer when levels are relatively high (??? 150 ??g/L). The epidemiologic evidence is less clear at the low-to-moderate concentrations typically observed in the United States. Accurate retrospective exposure assessment over a long time period is a major challenge in conducting epidemiologic studies of environmental factors and diseases with long latency, such as cancer. Objective: We estimated arsenic concentrations in the water supplies of 2,611 participants in a population-based case-control study in northern New England. Methods: Estimates covered the lifetimes of most study participants and were based on a combination of arsenic measurements at the homes of the participants and statistical modeling of arsenic concentrations in the water supply of both past and current homes. We assigned a residential water supply arsenic concentration for 165,138 (95%) of the total 173,361 lifetime exposure years (EYs) and a workplace water supply arsenic level for 85,195 EYs (86% of reported occupational years). Results: Three methods accounted for 93% of the residential estimates of arsenic concentration: direct measurement of water samples (27%; median, 0.3 ??g/L; range, 0.1-11.5), statistical models of water utility measurement data (49%; median, 0.4 ??g/L; range, 0.3-3.3), and statistical models of arsenic concentrations in wells using aquifers in New England (17%; median, 1.6 ??g/L; range, 0.6-22.4). Conclusions: We used a different validation procedure for each of the three methods, and found our estimated levels to be comparable with available measured concentrations. This methodology allowed us to calculate potential drinking water exposure over long periods.

Groundwater levels and water quality during a 96-hour aquifer test in Pickaway County, Ohio, 2012

USGS Publications Warehouse

Haefner, Ralph J.; Runkle, Donna L.; Mailot, Brian E.

2014-01-01

During October–November 2012, a 96-hour aquifer test was performed at a proposed well field in northern Pickaway County, Ohio, to investigate groundwater with elevated nitrate concentrations. Earlier sampling done by the City of Columbus revealed that some wells had concentrations of nitrate that approached 10 milligrams per liter (mg/L), whereas other wells and the nearby Scioto River had concentrations from 2 to 6 mg/L. The purpose of the current test was to examine potential changes in water quality that may be expected if the site was developed into a public water-supply source; therefore, water-transmitting properties determined during a previous test were not determined a second time. Before and during the test, water-level data and water-quality samples were obtained from observation wells while a test production well was pumped at 1,300 gallons per minute. Before the test, local groundwater levels indicated that groundwater was being discharged to the nearby Scioto River, but during the test, the stream was losing streamflow owing to infiltration. Water levels declined in the pumping well, in adjacent observation wells, and in a nearby streambed piezometer as pumping commenced. The maximum drawdown in the pumping well was 29.75 feet, measured about 95 hours after pumping began. Water-quality data, including analyses for field parameters, major and trace elements, nutrients, and stable isotopes of oxygen and nitrogen in nitrate, demonstrated only small variations before and during the test. Concentrations of nitrate in five samples from the pumping well ranged from about 5.10 to 5.42 mg/L before and during the test, whereas concentrations of nitrate in five samples on or about the same sampling dates and times at a monitoring site on the Scioto River adjacent to the pumping well ranged from 3.46 to 4.97 mg/L. Water from two nearby observation wells had nitrate concentrations approaching 10 mg/L, which is the U.S. Environmental Protection Agency’s Maximum

Sea Level Data Archaeology for the Global Sea Level Observing System (GLOSS)

NASA Astrophysics Data System (ADS)

Bradshaw, Elizabeth; Matthews, Andy; Rickards, Lesley; Jevrejeva, Svetlana

2015-04-01

The Global Sea Level Observing System (GLOSS) was set up in 1985 to collect long term tide gauge observations and has carried out a number of data archaeology activities over the past decade, including sending member organisations questionnaires to report on their repositories. The GLOSS Group of Experts (GLOSS GE) is looking to future developments in sea level data archaeology and will provide its user community with guidance on finding, digitising, quality controlling and distributing historic records. Many records may not be held in organisational archives and may instead by in national libraries, archives and other collections. GLOSS will promote a Citizen Science approach to discovering long term records by providing tools for volunteers to report data. Tide gauge data come in two different formats, charts and hand-written ledgers. Charts are paper analogue records generated by the mechanical instrument driving a pen trace. Several GLOSS members have developed software to automatically digitise these charts and the various methods were reported in a paper on automated techniques for the digitization of archived mareograms, delivered to the GLOSS GE 13th meeting. GLOSS is creating a repository of software for scanning analogue charts. NUNIEAU is the only publically available software for digitising tide gauge charts but other organisations have developed their own tide gauge digitising software that is available internally. There are several other freely available software packages that convert image data to numerical values. GLOSS could coordinate a comparison study of the various different digitising software programs by: Sending the same charts to each organisation and asking everyone to digitise them using their own procedures Comparing the digitised data Providing recommendations to the GLOSS community The other major form of analogue sea level data is handwritten ledgers, which are usually observations of high and low waters, but sometimes contain higher

Regional water table (2000) and ground-water-level changes in the Mojave River and the Morongo ground-water basins, southwestern Mojave Desert, California

USGS Publications Warehouse

Smith, Gregory A.

2003-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water systems, and consequently, water availability. During 2000, the U. S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and the Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 500 wells, providing coverage for most of the basins. Twenty-nine hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 13 short-term (1996 to 2000) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 1998 and 2000 water-levels throughout the basins. In the Mojave River ground-water basins, water-level data showed little change from 1998 to 2000, with the exception of areas along the Mojave River. Water levels along the Mojave River were typically in decline or unchanged, with exceptions near the Hodge and the Lenwood outlet, where water levels rose in response to artificial recharge. The Morongo ground-water basin had virtually no change in water levels from 1998 to 2000, with the exception of Yucca Valley, where artificial recharge and ground-water withdrawal continues.

Integrated analysis of PALSAR/Radarsat-1 InSAR and ENVISAT altimeter data for mapping of absolute water level changes in Louisiana wetlands

USGS Publications Warehouse

Kim, J.-W.; Lu, Z.; Lee, H.; Shum, C.K.; Swarzenski, C.M.; Doyle, T.W.; Baek, S.-H.

2009-01-01

Interferometric Synthetic Aperture Radar (InSAR) has been used to detect relative water level changes in wetlands. We developed an innovative method to integrate InSAR and satellite radar altimetry for measuring absolute or geocentric water level changes and applied the methodology to remote areas of swamp forest in coastal Louisiana. Coherence analysis of InSAR pairs suggested that the HH polarization is preferred for this type of observation, and polarimetric analysis can help to identify double-bounce backscattering areas in the wetland. ENVISAT radar altimeter-measured 18-Hz (along-track sampling of 417 m) water level data processed with regional stackfile method have been used to provide vertical references for water bodies separated by levees. The high-resolution (~ 40 m) relative water changes measured from ALOS PALSAR L-band and Radarsat-1 C-band InSAR are then integrated with ENVISAT radar altimetry to obtain absolute water level. The resulting water level time series were validated with in situ gauge observations within the swamp forest. We anticipate that this new technique will allow retrospective reconstruction and concurrent monitoring of water conditions and flow dynamics in wetlands, especially those lacking gauge networks.

Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation.

PubMed

Susko, Michele L; Bloom, Michael S; Neamtiu, Iulia A; Appleton, Allison A; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F; Anastasiu, Doru; Gurzau, Eugen S

2017-04-01

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiṣ County, Romania. Women (n=94) with planned pregnancies of 5-20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. Copyright © 2016 Elsevier Inc. All rights reserved.

Low-level arsenic exposure via drinking water consumption and female fecundity - a preliminary investigation

PubMed Central

Susko, Michele L.; Bloom, Michael S.; Neamtiu, Iulia A.; Appleton, Allison A.; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F.; Anastasiu, Doru; Gurzau, Eugen S.

2017-01-01

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiş County, Romania. Women (n = 94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women For example, 1 μg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P = 0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. PMID:28061371

Space-based detection of wetlands' surface water level changes from L-band SAR interferometry

USGS Publications Warehouse

Wdowinski, S.; Kim, S.-W.; Amelung, F.; Dixon, T.H.; Miralles-Wilhelm, F.; Sonenshein, R.

2008-01-01

Interferometric processing of JERS-1 L-band Synthetic Aperture Radar (SAR) data acquired over south Florida during 1993-1996 reveals detectable surface changes in the Everglades wetlands. Although our study is limited to south Florida it has implication for other large-scale wetlands, because south Florida wetlands have diverse vegetation types and both managed and natural flow environments. Our analysis reveals that interferometric coherence level is sensitive to wetland vegetation type and to the interferogram time span. Interferograms with time spans less than six months maintain phase observations for all wetland types, allowing characterization of water level changes in different wetland environments. The most noticeable changes occur between the managed and the natural flow wetlands. In the managed wetlands, fringes are organized, follow patterns related to some of the managed water control structures and have high fringe-rate. In the natural flow areas, fringes are irregular and have a low fringe-rate. The high fringe rate in managed areas reflects dynamic water topography caused by high flow rate due to gate operation. Although this organized fringe pattern is not characteristic of most large-scale wetlands, the high level of water level change enables accurate estimation of the wetland InSAR technique, which lies in the range of 5-10??cm. The irregular and low rate fringe pattern in the natural flow area reflects uninterrupted flow that diffuses water efficiently and evenly. Most of the interferograms in the natural flow area show an elongated fringe located along the transitional zone between salt- and fresh-water wetlands, reflecting water level changes due to ocean tides. ?? 2007 Elsevier Inc. All rights reserved.

Water Resources Data for California, Water Year 1988. Volume 5. Ground-Water Data for California

USGS Publications Warehouse

Lamb, C.E.; Fogelman, R.P.; Grillo, D.A.

1989-01-01

Water resources data for the 1988 water year for California consist of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water-quality in wells. Volume 5 contains water levels for 980 observation wells and water-quality data for 239 observation monitoring wells. These data represent that part of the National water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

Accounting for water levels and black carbon-inclusive sediment-water partitioning of organochlorines in Lesser Himalaya, Pakistan using two-carbon model.

PubMed

Ali, Usman; Sweetman, Andrew James; Jones, Kevin C; Malik, Riffat Naseem

2018-06-18

This study was designed to monitor organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in riverine water of Lesser Himalaya along the altitude. Further, the sediment-water partitioning employing organic carbon and black carbon models were assessed. Results revealed higher water levels of organochlorine pesticides (0.07-41.4 ng L -1 ) and polychlorinated biphenyls (0.671-84.5 ng L -1 ) in Lesser Himalayan Region (LHR) of Pakistan. Spatially, elevated levels were observed in the altitudinal zone (737-975 masl) which is influenced by anthropogenic and industrial activities. Sediment-water partitioning of OCPs and PCBs were deduced using field data by employing one-carbon (f OC K OC ) and two-carbon Freundlich models (f OC K OC + f BC K BC C W nF-1 ). Results suggested improved measured vs predicted model concentrations when black carbon was induced in the model and suggested adsorption to be the dominant mechanism in phase partitioning of organochlorines in LHR.

Urinary excretion levels of water-soluble vitamins in pregnant and lactating women in Japan.

PubMed

Shibata, Katsumi; Fukuwatari, Tsutomu; Sasaki, Satoshi; Sano, Mitsue; Suzuki, Kahoru; Hiratsuka, Chiaki; Aoki, Asami; Nagai, Chiharu

2013-01-01

Recent studies have shown that the urinary excretion levels of water-soluble vitamins can be used as biomarkers for the nutritional status of these vitamins. To determine changes in the urinary excretion levels of water-soluble vitamins during pregnant and lactating stages, we surveyed and compared levels of nine water-soluble vitamins in control (non-pregnant and non-lactating women), pregnant and lactating women. Control women (n=37), women in the 2nd (16-27 wk, n=24) and 3rd trimester of pregnancy (over 28 wk, n=32), and early- (0-5 mo, n=54) and late-stage lactating (6-11 mo, n=49) women took part in the survey. The mean age of subjects was ~30 y, and mean height was ~160 cm. A single 24-h urine sample was collected 1 d after the completion of a validated, self-administered comprehensive diet history questionnaire to measure water-soluble vitamins or metabolites. The average intake of each water-soluble vitamin was ≍ the estimated average requirement value and adequate intake for the Japanese Dietary Reference Intakes in all life stages, except for vitamin B6 and folate intakes during pregnancy. No change was observed in the urinary excretion levels of vitamin B2, vitamin B6, vitamin B12, biotin or vitamin C among stages. Urine nicotinamide and folate levels were higher in pregnant women than in control women. Urine excretion level of vitamin B1 decreased during lactation and that of pantothenic acid decreased during pregnancy and lactation. These results provide valuable information for setting the Dietary Reference Intakes of water-soluble vitamins for pregnant and lactating women.

Evaluating changes to reservoir rule curves using historical water-level data

USGS Publications Warehouse

Mower, Ethan; Miranda, Leandro E.

2013-01-01

Flood control reservoirs are typically managed through rule curves (i.e. target water levels) which control the storage and release timing of flood waters. Changes to rule curves are often contemplated and requested by various user groups and management agencies with no information available about the actual flood risk of such requests. Methods of estimating flood risk in reservoirs are not easily available to those unfamiliar with hydrological models that track water movement through a river basin. We developed a quantile regression model that uses readily available daily water-level data to estimate risk of spilling. Our model provided a relatively simple process for estimating the maximum applicable water level under a specific flood risk for any day of the year. This water level represents an upper-limit umbrella under which water levels can be operated in a variety of ways. Our model allows the visualization of water-level management under a user-specified flood risk and provides a framework for incorporating the effect of a changing environment on water-level management in reservoirs, but is not designed to replace existing hydrological models. The model can improve communication and collaboration among agencies responsible for managing natural resources dependent on reservoir water levels.

Reading Ground Water Levels with a Smartphone

NASA Astrophysics Data System (ADS)

van Overloop, Peter-Jules

2015-04-01

Most ground water levels in the world are measured manually. It requires employees of water management organizations to visit sites in the field and execute a measurement procedure that requires special tools and training. Once the measurement is done, the value is jotted down in a notebook and later, at the office, entered in a computer system. This procedure is slow and prone to human errors. A new development is the introduction of modern Information and Communication Technology to support this task and make it more efficient. Two innovations are introduced to measure and immediately store ground water levels. The first method is a measuring tape that gives a sound and light when it just touches the water in combination with an app on a smartphone with which a picture needs to be taken from the measuring tape. Using dedicated pattern recognition algorithms, the depth is read on the tape and it is verified if the light is on. The second method estimates the depth using a sound from the smartphone that is sent into the borehole and records the reflecting waves in the pipe. Both methods use gps-localization of the smartphone to store the depths in the right location in the central database, making the monitoring of ground water levels a real-time process that eliminates human errors.

Secchi disk observation with spectral-selective glasses in blue and green waters.

PubMed

Lee, Zhongping; Shang, Shaoling; Lin, Gong; Liu, Tongtong; Liu, Yangyang; Du, Keping; Luis, Kelly

2017-08-21

Radiative transfer modeling of Secchi disk observations has historically been based on conjugated signals of eye response and radiance, where water's attenuation in the entire visible band is included in the attenuation when deciding the Secchi disk depth in water. Aas et al. [Ocean Sci.10(2), 177 (2014)Remote Sens. Environ.169, 139 (2015)] hypothesized that it is actually the attenuation in water's transparent window that matters to the observation of a Secchi disk in water. To test this hypothesis, observations of Secchi disks in blue and green waters were conducted via naked eyes, blue-pass glasses, and green-pass glasses. Measurement results indicate that for blue waters, the observed Secchi depths via naked eyes match the depths obtained with blue-pass glasses and much deeper than the depths with green-pass glasses, although the green-pass glasses match the highest response of human eyes. These observations experimentally support the hypothesis that our eye-brain system uses the contrast information in the transparent window to make a judgement decision regarding sighting a Secchi disk in water.

A level change in mutagenicity of Japanese tap water over the past 12 yr.

PubMed

Takanashi, Hirokazu; Kishida, Misako; Nakajima, Tsunenori; Ohki, Akira; Akiba, Michihiro

2011-05-01

A relative comparison study of mutagenicity in Japanese tap water was conducted for 1993 and 2005 surveys. It intended to assess the effects of advanced water treatment installations to water works, improvement of raw water quality and improvement of residual HOCl concentration controlling. Sampling points (taps) were the same in both surveys. The results of 245 samples obtained by the Ames Salmonella mutagenicity test (Ames test) were analyzed. The Ames tests were conducted by using Salmonella typhimurium TA98 and TA100 strains with and without exogenous activation (S9). With the exception of TA100-S9, the other conditions needed no discussion as a factor in the mutagenicity level change. The average mutagenicity in 1993 and 2005 under the conditions of TA100-S9 were 2600 and 1100 net revertantL(-1), respectively. This indicated that the mutagenicity level of Japanese tap water decreased during the 12-yr period. Particularly a remarkable decrease in mutagenicity was observed in the water works where the advanced water treatments were installed during the 12-yr period. The advanced water treatments were effective in decreasing the mutagenicity of tap water. Mutagenicity also decreased in the water works with conventional water treatments; the improvement of residual HOCl concentration controlling was also considered to be effective in decreasing the mutagenicity of tap water. Copyright © 2011 Elsevier Ltd. All rights reserved.

Long-term (1930-2010) trends in groundwater levels in Texas: influences of soils, landcover and water use.

PubMed

Chaudhuri, Sriroop; Ale, Srinivasulu

2014-08-15

Rapid groundwater depletion has raised grave concerns about sustainable development in many parts of Texas, as well as in other parts of the world. Previous hydrologic investigations on groundwater levels in Texas were conducted mostly on aquifer-specific basis, and hence lacked state-wide panoramic view. The aim of this study was to present a qualitative overview of long-term (1930-2010) trends in groundwater levels in Texas and identify spatial patterns by applying different statistical (boxplots, correlation-regression, hierarchical cluster analysis) and geospatial techniques (Moran's I, Local Indicators of Spatial Association) on 136,930 groundwater level observations from Texas Water Development Board's database. State-wide decadal median water-levels declined from about 14 m from land surface in the 1930s to about 36 m in the 2000s. Number of counties with deeper median water-levels (water-level depth>100 m) increased from 2 to 13 between 1930s and 2000s, accompanied by a decrease in number of counties having shallower median water-levels (water-level depth<25 m) from 134 to 113. Water-level declines across Texas, however, mostly followed logarithmic trends marked by leveling-off phenomena in recent times. Assessment of water-levels by Groundwater Management Areas (GMA), management units created to address groundwater depletion issues, indicated hotspots of deep water-levels in Texas Panhandle and GMA 8 since the 1960s. Contrasting patterns in water use, landcover, geology and soil properties distinguished Texas Panhandle from GMA 8. Irrigated agriculture is the major cause of depletion in the Texas Panhandle as compared to increasing urbanization in GMA 8. Overall our study indicated that use of robust spatial and statistical methods can reveal important details about the trends in water-level changes and shed lights on the associated factors. Due to very generic nature, techniques used in this study can also be applied to other areas with similar eco

Voyageurs National Park: Water-level regulation and effects on water quality and aquatic biology

USGS Publications Warehouse

Christensen, Victoria G.; Maki, Ryan P.; LeDuc, Jaime F.

2018-01-01

Following dam installations in the remote Rainy Lake Basin during the early 1900s, water-level fluctuations were considered extreme (1914–1949) compared to more natural conditions. In 1949, the International Joint Commission (IJC), which sets rules governing dam operation on waters shared by the United States and Canada, established the first rule curves to regulate water levels on these waterbodies. However, rule curves established prior to 2000 were determined to be detrimental to the ecosystem. Therefore, the IJC implemented an order in 2000 to change rule curves and to restore a more natural water regime. After 2000, measured chlorophyll-a concentrations in the two most eutrophic water bodies decreased whereas concentrations in oligotrophic lakes did not show significant water-quality differences. Fish mercury data were inconclusive, due to the variation in water levels and fish mercury concentrations, but can be used by the IJC as part of a long term data set.

Regional Water Table (1998) and Ground-Water-Level Changes in the Mojave River, and the Morongo Ground-Water Basins, San Bernardino County, California

USGS Publications Warehouse

Smith, Gregory A.; Pimentel, M. Isabel

2000-01-01

The Mojave River and the Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The rapid and continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The continuing collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water systems and, consequently, water availability. During 1998 the U.S. Geological Survey and other agencies made approximately 2,370 water-level measurements in the Mojave River and the Morongo ground-water basins. These data document recent conditions and changes in ground-water levels. A water-level contour map was drawn using data from 450 wells, providing coverage for most of both basins. Twenty-three hydrographs show long-term (as much as 70 years) water-level trends throughout the basins. To help show effects of late seasonal recharge along the Mojave River, 14 short-term (13 years) hydrographs were created. A water-level change map was compiled to enable comparison of 1996 and 1998 water levels. The Mojave River and the Morongo ground-water basins had little change in water levels between 1996 and 1998 - with the exception of the areas of the Yucca Valley affected by artificial recharge. Other water-level changes were localized and reflected pumping or measurements made before seasonal recharge. Three areas of perched ground water were identified: El Mirage Lake (dry), Adelanto, and Lucerne Valley.

Airborne Observations of Water Vapor Deuterium Excess in the Mid-Latitude Lower Troposphere

NASA Astrophysics Data System (ADS)

Salmon, O. E.; Welp, L.; Shepson, P. B.; Stirm, B. H.

2017-12-01

Water vapor is responsible for over half of the natural atmospheric greenhouse effect. As global temperatures increase due to fossil fuel combustion, atmospheric water vapor concentrations are also expected to increase in positive feedback. Additionally, studies have shown that urban areas can influence humidity levels, and the frequency and intensity of precipitation events. It is thus important to understand anthropogenic modification of the hydrological cycle, particularly around urban areas, where over half of the world's population resides. Airborne measurements of water vapor isotopologues containing 2H and 18O were conducted to better understand processes influencing atmospheric moisture levels around urban areas. Airborne measurements were conducted around the Indianapolis and Washington, D.C.-Baltimore areas during afternoon hours in February and March 2016, using a Los Gatos Research Water Vapor Isotope Analyzer installed in Purdue University's experimental aircraft, the Airborne Laboratory for Atmospheric Research. The measurements of 2H and 18O allow for the calculation of deuterium excess (= δ2H - 8*δ18O), which provides information about non-equilibrium processes, such as kinetic effects, air parcel mixing, and transpiration. There are few studies that have reported observations of deuterium excess above the surface level ( 100 m). During the measurement campaign, vertical profiles were frequently conducted from 300 m above the ground to an altitude of approximately 1.5 km, effectively characterizing water vapor isotope profiles spanning the boundary layer and lower free troposphere. Measurements probed the transition from planetary boundary layer air to free troposphere air to provide high resolution deuterium excess information across this interface. Processes such as Rayleigh distillation, atmospheric mixing, and surface fluxes potentially impacting water vapor deuterium excess through the boundary layer and free troposphere with be discussed.

Exponential Boundary Observers for Pressurized Water Pipe

NASA Astrophysics Data System (ADS)

Hermine Som, Idellette Judith; Cocquempot, Vincent; Aitouche, Abdel

2015-11-01

This paper deals with state estimation on a pressurized water pipe modeled by nonlinear coupled distributed hyperbolic equations for non-conservative laws with three known boundary measures. Our objective is to estimate the fourth boundary variable, which will be useful for leakage detection. Two approaches are studied. Firstly, the distributed hyperbolic equations are discretized through a finite-difference scheme. By using the Lipschitz property of the nonlinear term and a Lyapunov function, the exponential stability of the estimation error is proven by solving Linear Matrix Inequalities (LMIs). Secondly, the distributed hyperbolic system is preserved for state estimation. After state transformations, a Luenberger-like PDE boundary observer based on backstepping mathematical tools is proposed. An exponential Lyapunov function is used to prove the stability of the resulted estimation error. The performance of the two observers are shown on a water pipe prototype simulated example.

A note on sea level variability at Clipperton Island from GEOSAT and in-situ observations

NASA Astrophysics Data System (ADS)

Maul, George A.; Hansen, Donald V.; Bravo, Nicolas J.

During the 1986-1989 Exact Repeat Mission (ERM) of GEOSAT, in-situ observations of sea level at Clipperton Island (10°N/109°W) and satellite-tracked free-drifting drogued buoys in the eastern tropical Pacific Ocean are concurrently available. A map of the standard deviations of GEOSAT sea surface heights (2.9 years) shows a variance maximum along ˜12°N from Central America, past Clipperton to ˜160°W. Sea floor pressure gauge observations from a shallow (10m depth) site on Clipperton Island and an ERM crossover point in deep water nearby show a correlation of r = 0.76 with a residual of ±6.7 cm RMS. Approximately 17% of the difference (GEOSAT minus sea level) is characterized by a 4 cm amplitude 0° phase annual harmonic, which is probably caused by unaccounted-for tropospheric water vapor affecting the altimeter and/or ERM orbit error removal. Wintertime anticyclonic mesoscale eddies advecting past Clipperton Island each year have GEOSAT sea surface height and in-situ sea level signals of more than 30 cm, some of which are documented by the satellite-tracked drifters. Meridional profiles of the annual harmonic of zonal geostrophic current from GEOSAT and from the drifters both show synchronous maxima in the North Equatorial Countercurrent and the North Equatorial Current. Other Clipperton sea level maxima seen during late spring of each year may involve anticyclonic vortices formed along Central America the previous winter.

Water level, specific conductance, and water temperature data, San Francisco Bay, California, for Water Year 2000

USGS Publications Warehouse

Buchanan, P.A.

2002-01-01

Time series of water-level, specific-conductance, and watertemperature data were collected at seven sites in San Francisco Bay during water year 2000 (October 1, 1999 through September 30, 2000). Water-level data were recorded only at Point San Pablo. Specific-conductance and water-temperature data were recorded at 15-minute intervals at the following locations (Figure 1): • Carquinez Strait at Carquinez Bridge • Napa River at Mare Island Causeway near Vallejo • San Pablo Bay at Petaluma River Channel Marker 9 • San Pablo Strait at Point San Pablo • Central San Francisco Bay at Presidio Military Reservation • Central San Francisco Bay at Pier 24 • South San Francisco Bay at San Mateo Bridge near Foster City.

Estimation of distributional parameters for censored trace-level water-quality data

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

Gilliom, R.J.; Helsel, D.R.

1984-01-01

A recurring difficulty encountered in investigations of many metals and organic contaminants in ambient waters is that a substantial portion of water-sample concentrations are below limits of detection established by analytical laboratories. Several methods were evaluated for estimating distributional parameters for such censored data sets using only uncensored observations. Their reliabilities were evaluated by a Monte Carlo experiment in which small samples were generated from a wide range of parent distributions and censored at varying levels. Eight methods were used to estimate the mean, standard deviation, median, and interquartile range. Criteria were developed, based on the distribution of uncensored observations,more » for determining the best-performing parameter estimation method for any particular data set. The most robust method for minimizing error in censored-sample estimates of the four distributional parameters over all simulation conditions was the log-probability regression method. With this method, censored observations are assumed to follow the zero-to-censoring level portion of a lognormal distribution obtained by a least-squares regression between logarithms of uncensored concentration observations and their z scores. When method performance was separately evaluated for each distributional parameter over all simulation conditions, the log-probability regression method still had the smallest errors for the mean and standard deviation, but the lognormal maximum likelihood method had the smallest errors for the median and interquartile range. When data sets were classified prior to parameter estimation into groups reflecting their probable parent distributions, the ranking of estimation methods was similar, but the accuracy of error estimates was markedly improved over those without classification. 6 figs., 6 tabs.« less

Levels of exposure from drinking water.

PubMed

van Dijk-Looijaard, A M; van Genderen, J

2000-01-01

The relative exposure from drinking water is generally small, although there is a lack of information on total daily intake of individual organic micropollutants. There are, however, a few exceptions. Materials used in domestic distribution systems (lead, copper and plastics) may cause a deterioration of the water quality, especially in stagnant water. The relative exposure to the related compounds may increase considerably. Monitoring data from the tap (with defined sampling techniques) are needed. Also, disinfection/oxidation by-products (bromate, trihalomethanes) can be present in drinking water in considerable amounts and the relative exposure from drinking water may even approach 100%. Especially for volatile organic micropollutants, exposure routes from drinking water other than ingestion must be taken into account (inhalation, percutaneous uptake). When there is a need for detection of substances at very low levels it is important that the measurements are reliable. International interlaboratory comparisons for organic micropollutants are lacking at the moment.

Response in the trophic state of stratified lakes to changes in hydrology and water level: potential effects of climate change

USGS Publications Warehouse

Robertson, Dale M.; Rose, William J.

2011-01-01

To determine how climate-induced changes in hydrology and water level may affect the trophic state (productivity) of stratified lakes, two relatively pristine dimictic temperate lakes in Wisconsin, USA, were examined. Both are closed-basin lakes that experience changes in water level and degradation in water quality during periods of high water. One, a seepage lake with no inlets or outlets, has a small drainage basin and hydrology dominated by precipitation and groundwater exchange causing small changes in water and phosphorus (P) loading, which resulted in small changes in water level, P concentrations, and productivity. The other, a terminal lake with inlets but no outlets, has a large drainage basin and hydrology dominated by runoff causing large changes in water and P loading, which resulted in large changes in water level, P concentrations, and productivity. Eutrophication models accurately predicted the effects of changes in hydrology, P loading, and water level on their trophic state. If climate changes, larger changes in hydrology and water levels than previously observed could occur. If this causes increased water and P loading, stratified (dimictic and monomictic) lakes are expected to experience higher water levels and become more eutrophic, especially those with large developed drainage basins.

Water level effects on breaking wave setup for Pacific Island fringing reefs

NASA Astrophysics Data System (ADS)

Becker, J. M.; Merrifield, M. A.; Ford, M.

2014-02-01

The effects of water level variations on breaking wave setup over fringing reefs are assessed using field measurements obtained at three study sites in the Republic of the Marshall Islands and the Mariana Islands in the western tropical Pacific Ocean. At each site, reef flat setup varies over the tidal range with weaker setup at high tide and stronger setup at low tide for a given incident wave height. The observed water level dependence is interpreted in the context of radiation stress gradients specified by an idealized point break model generalized for nonnormally incident waves. The tidally varying setup is due in part to depth-limited wave heights on the reef flat, as anticipated from previous reef studies, but also to tidally dependent breaking on the reef face. The tidal dependence of the breaking is interpreted in the context of the point break model in terms of a tidally varying wave height to water depth ratio at breaking. Implications for predictions of wave-driven setup at reef-fringed island shorelines are discussed.

Statistical analysis of water-level, springflow, and streamflow data for the Edwards Aquifer in south-central Texas

USGS Publications Warehouse

Puente, Celso

1976-01-01

Water-level, springflow, and streamflow data were used to develop simple and multiple linear-regression equations for use in estimating water levels in wells and the flow of three major springs in the Edwards aquifer in the eastern San Antonio area. The equations provide daily, monthly, and annual estimates that compare very favorably with observed data. Analyses of geologic and hydrologic data indicate that the water discharged by the major springs is supplied primarily by regional underflow from the west and southwest and by local recharge in the infiltration area in northern Bexar, Comal, and Hays Counties.

Ground-water levels in the alluvial aquifer in Eastern Arkansas, 1989

USGS Publications Warehouse

Westerfield, P.W.; Baxter, C.R.

1990-01-01

This report, prepared by the U.S. Geological Survey in cooperation with the Arkansas Soil and Water Conservation Commission, the U.S. Soil Conservation Service and local Conservation Districts, contains groundwater level measurements of 504 wells that tap the alluvial aquifer in the Quaternary deposits of the Mississippi Alluvial Plain. The measurements were made by district Soil Conservation Service personnel during 1989. The shallowest prepumping season water levels occurred in Clay, Greene, Independence, Mississippi, Phillips, and Randolph Counties where water levels averaged less than 20 ft below the land surface. The deepest water levels occurred in Arkansas, Lonoke, Poinsett, and Prairie Counties where water levels of more than 100 ft were measured. Water levels in the postpumping season averaged about 2.5 ft lower than during the prepumping season. (USGS)

Ground-water levels in the alluvial aquifer in eastern Arkansas, 1988

USGS Publications Warehouse

Westerfield, P.W.; Baxter, C.R.

1990-01-01

This report, prepared by the U.S. Geological Survey in cooperation with the Arkansas Soil and Water Conservation Commission, the U.S. Soil Conservation Service, and local Conservation Districts, contains groundwater level measurements of 509 wells that tap the alluvial aquifer in the Quaternary deposits of the Mississippi Alluvial Plain. The measurements were made by district Soil Conservation Service personnel during 1988. The shallowest prepumping season water levels occurred in Ashley, Clay, Greene, Mississippi, Phillips, and Randolph Counties where water levels averaged less than 20 ft below the land surface. The deepest water levels occurred in Arkansas, Lonoke, Poinsett, and Prairie Counties where water levels of more than 100 ft below land surface were measured. Water levels in the postpumping season averaged about 4.1 ft lower than during the prepumping season. (USGS)

Persistent water level changes in a well near Parkfield, California, due to local and distant earthquakes

NASA Astrophysics Data System (ADS)

Roeloffs, Evelyn A.

1998-01-01

of the year. The first 2.5 days of a typical coseismic water level rise could be caused by a small coseismic discharge decrease at a point several tens of meters from the well. Alternatively, the entire coseismic water level signal could represent diffusion of an abrupt coseismic pore pressure increase within several meters of the well, produced by a mechanism akin to that of liquefaction. The coseismic water level changes in the BV well resemble, and may share a mechanism with, coseismic water level, stream discharge, and groundwater temperature changes at other locations where preearthquake changes have also been reported. No preearthquake changes have been observed at the BV well site, however.

Persistent water level changes in a well near Parkfield, California, due to local and distant earthquakes

USGS Publications Warehouse

Roeloffs, E.A.

1998-01-01

of the year. The first 2.5 days of a typical coseismic water level rise could be caused by a small coseismic discharge decrease at a point several tens of meters from the well. Alternatively, the entire coseismic water level signal could represent diffusion of an abrupt coseismic pore pressure increase within several meters of the well, produced by a mechanism akin to that of liquefaction. The coseismic water level changes in the BV well resemble, and may share a mechanism with, coseismic water level, stream discharge, and groundwater temperature changes at other locations where preearthquake changes have also been reported. No preearthquake changes have been observed at the BV well site, however.

The influence of sea-level rise on fringing reef sediment dynamics: field observations and numerical modeling

USGS Publications Warehouse

Storlazzi, Curt D.; Field, Michael E.; Elias, Edwin; Presto, M. Katherine

2011-01-01

While most climate projections suggest that sea level may rise on the order of 0.5-1.0 m by 2100, it is not clear how fluid flow and sediment transport on fringing reefs might change in response to this rapid sea-level rise. Field observations and numerical modeling suggest that an increase in water depth on the order of 0.5-1.0 m on a fringing reef flat would result in larger significant wave heights and wave-driven shear stresses, which, in turn, would result in an increase in both the size and quantity of sediment that can be resuspended from the seabed or eroded from coastal plain deposits. Greater wave- and wind-driven currents would develop on the reef flat with increasing water depth, increasing the offshore flux of water and sediment from the inner reef flat to the outer reef flat and fore reef where coral growth is typically greatest.

Effects of decreased ground-water withdrawal on ground-water levels and chloride concentrations in Camden County, Georgia, and ground-water levels in Nassau County, Florida, from September 2001 to May 2003

USGS Publications Warehouse

Peck, Michael F.; McFadden, Keith W.; Leeth, David C.

2005-01-01

During October 2002, the Durango Paper Company formerly Gillman Paper Company) in St. Marys, Georgia, shut down paper-mill operations; the shutdown resulted in decreased ground-water withdrawal in Camden County by 35.6 million gallons per day. The decrease in withdrawal resulted in water-level rise in wells completed in the Floridan aquifer system and the overlying surficial and Brunswick aquifer systems; many wells in the St. Marys area flowed for the first time since the mill began operations during 1941. Pumping at the mill resulted in the development of a cone of depression that coalesced with a larger adjacent cone of depression at Fernandina Beach, Florida. Since closure of the mill, the cone at St. Marys is no longer present, although the cone still exists at Fernandina Beach, Florida. Historical water-level data from the production wells at the mill indicate that the pumping water level ranged from 68 to 235 feet (ft) below North American Vertical Datum of 1988 (NAVD 88) and averaged about 114 ft when the mill was operating. Since the shutdown, it is estimated that water levels at the mill have risen about 140 ft and are now at about 30 ft above NAVD 88. The water-level rise in wells in outlying areas in Camden County was less pronounced and ranged from about 5 to 10 ft above NAVD 88. Because of the regional upward water-level trend in the Upper Floridan aquifer that started during 19992000 in most of the coastal area, combined with a steeper upward trend beginning during October 2002, it was not possible to determine if the 510 ft rise in water levels in wells away from St. Marys was due to the mill closure. In addition to water-level rise of 2226 ft in the Floridan aquifer system, water-level rises in the overlying surficial and Brunswick aquifer systems at St. Marys after the shutdown indicate upward leakage of water. Water levels had stabilized in the confined surficial and Upper and Lower Floridan aquifers by AprilMay 2003; however, the water level in

Statistical summaries of ground-water level data collected in the Suwannee River Water Management District, 1948 to 1994

USGS Publications Warehouse

Collins, J.J.; Freeman, L.D.

1996-01-01

Since 1948, ground-water level data have beensystematically collected from selected wells in theSuwannee River Water Management District (SRWMD) by the U.S. Geological Survey (USGS),the SRWMD, and other agencies. Records of waterlevels in the SRWMD (fig. 1), collected by the USGS and SRWMD through 1990, and by the SRWMD from 1990 to 1994, have been published for many years in the USGS annual report series "Water Resources Data for Florida." However, no systematic statistical summaries of water levels in the SRWMD have been previously published. The need for such statistical summary data forevaluations of drought severity, ground-water supplyavailability, and minimum water levels for regulatory purposes increases daily as demands for ground-water usage increase. Also, much of the base flow of the Suwannee River is dependent upon ground water. As the population and demand for ground water for drinking water and irrigation purposes increase, the ability to quickly and easily predict trends in ground-water availability will become paramount. In response to this need, the USGS, in cooperation with the SRWMD, compiled this report. Ground-water sta tistics for 136 sites are presented as well as figures showing water levels that were measured in wells from 1948 through September 1994. In 1994, the SRWMD and the USGS began a long- term program of cooperative studies designed tobetter understand minimum and maximum streamflows and ground-water levels in the SRWMD. Minimum and maximum flows and levels are needed by the district to manage the surface- and ground-water resources of the SRWMD and to maintain or improve the various ecosystems. Data evaluation was a necessary first step in the long- term SRWMD ground-water investigations program, because basic statistics for ground-water levels are not included in the USGS annual data reports such as "Water Resources Data for Florida, Water Year 1994" (Fran klin and others, 1995). Statistics included in this report were generated

Changes in water manganese levels and longitudinal assessment of intellectual function in children exposed through drinking water.

PubMed

Dion, Laurie-Anne; Saint-Amour, Dave; Sauvé, Sébastien; Barbeau, Benoit; Mergler, Donna; Bouchard, Maryse F

2018-01-01

Manganese is commonly found in water but potential neurotoxic effects from exposure through drinking water are poorly understood. We previously reported a cross-sectional study showing that drinking water Mn concentration was associated with lower IQ in children aged 6 to 13 years. For this follow-up study, we aimed to re-assess the relation between exposure to Mn from drinking water and IQ at adolescence. In addition, we aimed to examine whether changes in drinking water Mn concentration was associated with changes in IQ scores. From the 380 children enrolled in the baseline study, 287 participated to this follow-up study conducted in average 4.4 years after. Mn concentration was measured in home tap water and children's hair. The relationships between these Mn exposure indicators and IQ scores (Weschsler Abbreviated Scale of Intelligence) at follow-up were assessed with linear regression analysis, adjusting for potential confounders. Intra-individual differences in IQ scores between the two examinations were compared for children whose Mn concentration in water remained stable between examinations, increased or decreased. The mean age at follow-up was 13.7 years (range, 10.5 to 18.0 years). Geometric mean of Mn concentration in water at follow-up was 14.5μg/L. Higher Mn concentration in water measured at follow-up was associated with lower Performance IQ in girls (β for a 10-fold increase=-2.8, 95% confidence intervals [CI] -4.8 to -0.8) and higher Performance IQ in boys (β=3.9, 95% CI 1.4 to 6.4). IQ scores were not significantly associated with Mn concentration in hair, although similar trends as for concentration in water were observed. For children whose Mn concentration in water increased between baseline and follow-up, Performance IQ scores decreased significantly (intra-individual difference, -2.4 points). Higher levels of Mn in drinking water were associated with lower Performance IQ in girls, whereas the opposite was observed in boys. These findings

Regression models of monthly water-level change in and near the Closed Basin Division of the San Luis Valley, south-central Colorado

USGS Publications Warehouse

Watts, Kenneth R.

1995-01-01

The Bureau of Reclamation is developing a water-resource project, the Closed Basin Division, in the San Luis Valley of south-central Colorado that is designed to salvage unconfined ground water that currently is discharged as evapotranspiration. The water table in and near the 130,000-acre Closed Basin Division area will be lowered by an annual withdrawal of as much as 100,000 acre-feet of ground water from the unconfined aquifer. The legislation authorizing the project limits resulting drawdown of the water table in preexisting irrigation and domestic wells outside the Closed Basin Division to a maximum of 2 feet. Water levels in the closed basin in the northern part of the San Luis Valley historically have fluctuated more than 2 feet in response to water-use practices and variation of climatically controlled recharge and discharge. Declines of water levels in nearby wells that are caused by withdrawals in the Closed Basin Division can be quantified if water-level fluctuations that result from other water-use practices and climatic variations can be estimated. This study was done to evaluate water-level change at selected observation wells in and near the Closed Basin Division. Regression models of monthly water-level change were developed to predict monthly water-level change in 46 selected observation wells. Predictions of monthly water-level change are based on one or more of the following: elapsed time, cosine and sine functions with an annual period, streamflow depletion of the Rio Grande, electrical use for agricultural purposes, runoff into the closed basin, precipitation, and mean air temperature. Regression models for five of the wells include only an intercept term and either an elapsed-time term or terms determined by the cosine and sine functions. Regression models for the other 41 wells include 1 to 4 of the 5 other variables, which can vary from month to month and from year to year. Serial correlation of the residuals was detected in 24 of the

A study of water uptake by selected superdisintegrants from the sub-molecular to the particulate level.

PubMed

Barmpalexis, P; Syllignaki, P; Kachrimanis, K

2018-06-01

Water diffusion through the matrix of three superdisintegrants, namely sodium starch glycolate (SSG), croscarmellose sodium (cCMC-Na) and crospovidone (cPVP), was studied at the sub-molecular level using Attenuated Total Reflectance (ATR)-FTIR spectroscopy and molecular dynamics simulations, and the results were correlated to water uptake studies conducted at the particulate level using Parallel Exponential Kinetics (PEK) modeling in dynamic moisture sorption studies and optical microscopy. ATR-FTIR studies indicated that water diffuses inside cPVP by a single fast acting process, while in SSG and cCMC-Na, a slow and a fast process acting simultaneously, were identified. The same pattern regarding the rate of water uptake for all superdisintegrants was found also at the particulate level by PEK modeling. Moreover, molecular dynamics simulation helped elucidate the hydrogen bonding patterns formed between water-SSG and water-cCMC-Na, mainly via their carboxylic oxygen atoms and secondarily via their hydroxyl groups, while cPVP formed hydrogen bonds only through carbonyl oxygen. Finally, cPVP chains showed significant flexibility during hydration, while cCMC-Na and SSG chains retain their conformation to some extent, explaining the extensive swelling observed also at the particulate level by optical microscopy hydration studies.

Observation of water mass characteristics in the southwestern Mariana Trench

NASA Astrophysics Data System (ADS)

Xu, H.; Xie, Q.; Hong, B.

2016-12-01

The identification of large water mass characteristic can help oceanographer to better understand the oceanic circulation structures and other physical processes in open oceans. In current stage, the water mass characteristics were recognized well by extensive observation in the upper ocean, however, it was rarely studied in deep oceans, especially for deep trench with > 6000 m depth. In this study, we use observed data collected by CTDs during several surveys to investigate the water mass physical characteristic and transport in the world deepest trench, `Challenger Deep', in the southwestern Mariana Trench. The preliminary results show complex vertical structures of water mass in this trench. From surface to 4500 m, the water masses are occupied by typical tropical surface water, NPTUW, NPMW, NPIW and NPDW. Under 4500m, the water mass shows mixing characteristics of NPDW and AABW, which indicate AABW can be transported by form the deep ocean of the South Ocean to Northwestern Pacific and it can affect local water mass characteristics. The baroclinic geostrophic current calculated from the CTDs data shows the westerly transport of water mass can reach about 1.0 SV in the trench which is close to previous results.

Observations of Water Vapor Outflow from NML Cygnus

NASA Astrophysics Data System (ADS)

Zubko, Viktor; Li, Di; Lim, Tanya; Feuchtgruber, Helmut; Harwit, Martin

2004-07-01

We report new observations of the far-infrared and submillimeter water vapor emission of NML Cygnus based on data gathered with the Infrared Space Observatory and the Submillimeter Wave Astronomy Satellite. We compare the emission from NML Cyg to that previously published for VY CMa and W Hya in an attempt to establish the validity of recently proposed models for the outflow from evolved stars. The data obtained support the contention by Ivezić & Elitzur that the atmospheres of evolved stars obey a set of scaling laws in which the optical depth of the outflow is the single most significant scaling parameter, affecting both the radiative transfer and the dynamics of the outflow. Specifically, we provide observations comparing the water vapor emission from NML Cyg, VY CMa, and W Hya and find, to the extent permitted by the quality of our data, that the results are in reasonable agreement with a model developed by Zubko & Elitzur. Using this model we derive a mass loss based on the dust opacities, spectral line fluxes, and outflow velocities of water vapor observed in the atmospheres of these oxygen-rich giants. For VY CMa and NML Cyg, we also obtain an estimate of the stellar mass.

Predicting Near-Term Water Quality from Satellite Observations of Watershed Conditions

NASA Astrophysics Data System (ADS)

Weiss, W. J.; Wang, L.; Hoffman, K.; West, D.; Mehta, A. V.; Lee, C.

2017-12-01

Despite the strong influence of watershed conditions on source water quality, most water utilities and water resource agencies do not currently have the capability to monitor watershed sources of contamination with great temporal or spatial detail. Typically, knowledge of source water quality is limited to periodic grab sampling; automated monitoring of a limited number of parameters at a few select locations; and/or monitoring relevant constituents at a treatment plant intake. While important, such observations are not sufficient to inform proactive watershed or source water management at a monthly or seasonal scale. Satellite remote sensing data on the other hand can provide a snapshot of an entire watershed at regular, sub-monthly intervals, helping analysts characterize watershed conditions and identify trends that could signal changes in source water quality. Accordingly, the authors are investigating correlations between satellite remote sensing observations of watersheds and source water quality, at a variety of spatial and temporal scales and lags. While correlations between remote sensing observations and direct in situ measurements of water quality have been well described in the literature, there are few studies that link remote sensing observations across a watershed with near-term predictions of water quality. In this presentation, the authors will describe results of statistical analyses and discuss how these results are being used to inform development of a desktop decision support tool to support predictive application of remote sensing data. Predictor variables under evaluation include parameters that describe vegetative conditions; parameters that describe climate/weather conditions; and non-remote sensing, in situ measurements. Water quality parameters under investigation include nitrogen, phosphorus, organic carbon, chlorophyll-a, and turbidity.

A nested observation and model approach to non linear groundwater surface water interactions.

NASA Astrophysics Data System (ADS)

van der Velde, Y.; Rozemeijer, J. C.; de Rooij, G. H.

2009-04-01

of nested-scale, high frequency observations. The distributed hydrological model results will be used to show transient catchment scale relations between groundwater levels and discharges. These analyses lead to a simple expression that can describe catchment scale groundwater surface water interactions.

Bi-Level Decision Making for Supporting Energy and Water Nexus

NASA Astrophysics Data System (ADS)

Zhang, X.; Vesselinov, V. V.

2016-12-01

The inseparable relationship between energy production and water resources has led to the emerging energy-water nexus concept, which provides a means for integrated management and decision making of these two critical resources. However, the energy-water nexus frequently involves decision makers with different and competing management objectives. Furthermore, there is a challenge that decision makers and stakeholders might be making decisions sequentially from a higher level to a lower level, instead of at the same decision level, whereby the objective of a decision maker at a higher level should be satisfied first. In this study, a bi-level decision model is advanced to handle such decision-making situations for managing the energy-water nexus. The work represents a unique contribution to developing an integrated decision-support framework/tool to quantify and analyze the tradeoffs between the two-level energy-water nexus decision makers. Here, plans for electricity generation, fuel supply, water supply, capacity expansion of the power plants and environmental impacts are optimized to provide effective decision support. The developed decision-support framework is implemented in Julia (a high-level, high-performance dynamic programming language for technical computing) and is a part of the MADS (Model Analyses & Decision Support) framework (http://mads.lanl.gov). To demonstrate the capabilities of the developed methodology, a series of analyses are performed for synthetic problems consistent with actual real-world energy-water nexus management problems.

Analysis of water level variation of lakes and reservoirs in Xinjiang, China using ICESat laser altimetry data (2003–2009)

PubMed Central

Liu, Hongxing; Chen, Yaning; Shu, Song; Wu, Qiusheng; Wang, Shujie

2017-01-01

This study utilizes ICESat Release 33 GLA14 data to analyse water level variation of Xinjiang’s lakes and reservoirs from 2003 to 2009. By using Landsat images, lakes and reservoirs with area larger than 1 km2 are numerically delineated with a software tool. Based on ICESat observations, we analyse the characteristics of water level variation in different geographic environments, as well as investigate the reasons for the variation. Results indicate that climatic warming contributes to rising water levels in lakes in mountainous areas, especially for lakes that are recharged by snow and glacial melting. For lakes in oases, the water levels are affected jointly by human activity and climate change, while the water levels of reservoirs are mainly affected by human activity. Comparing the annual average rates of water levels, those of lakes are higher than those of reservoirs in oasis areas. The main reasons for the decreasing water levels in desert regions are the reduction of recharged runoff and high evaporation. By analysing the variation of water levels and water volume in different geologic environments, it is found that water level and volume increased in mountainous regions, and decreased in oasis regions and desert regions. Finding also demonstrate that decreasing volume is greater than increasing volume, which results in decreasing total volume of Xinjiang lakes and reservoirs. PMID:28873094

Galactic water vapor emission: further observations of variability.

PubMed

Knowles, S H; Mayer, C H; Sullivan, W T; Cheung, A C

1969-10-10

Recent observations of the 1.35-centimeter line emission of water vapor from galactic sources show short-term variability in the spectra of several sources. Two additional sources, Cygnus 1 and NGC 6334N, have been observed, and the spectra of W49 and VY Canis Majoris were measured over a wider range of radial velocity.

Aquatic treadmill water level influence on pelvic limb kinematics in cranial cruciate ligament-deficient dogs with surgically stabilised stifles.

PubMed

Bertocci, G; Smalley, C; Brown, N; Bialczak, K; Carroll, D

2018-02-01

To compare pelvic limb joint kinematics and temporal gait characteristics during land-based and aquatic-based treadmill walking in dogs that have undergone surgical stabilisation for cranial cruciate ligament deficiency. Client-owned dogs with surgically stabilised stifles following cranial cruciate ligament deficiency performed three walking trials consisting of three consecutive gait cycles on an aquatic treadmill under four water levels. Hip, stifle and hock range of motion; peak extension; and peak flexion were assessed for the affected limb at each water level. Gait cycle time and stance phase percentage were also determined. Ten client-owned dogs of varying breeds were evaluated at a mean of 55·2 days postoperatively. Aquatic treadmill water level influenced pelvic limb kinematics and temporal gait outcomes. Increased stifle joint flexion was observed as treadmill water level increased, peaking when the water level was at the hip. Similarly, hip flexion increased at the hip water level. Stifle range of motion was greatest at stifle and hip water levels. Stance phase percentage was significantly decreased when water level was at the hip. Aquatic treadmill walking has become a common rehabilitation modality following surgical stabilisation of cranial cruciate ligament deficiency. However, evidence-based best practice guidelines to enhance stifle kinematics do not exist. Our findings suggest that rehabilitation utilising a water level at or above the stifle will achieve the best stifle kinematics following surgical stifle stabilisation. © 2017 British Small Animal Veterinary Association.

Recording of fluid, beverage and water intakes at the population level in Europe.

PubMed

Gandy, Joan; Le Bellego, Laurent; König, Jürgen; Piekarz, Ana; Tavoularis, Gabriel; Tennant, David R

2016-08-01

The European Food Safety Authority's 2010 scientific opinion on dietary reference values for total water intakes was partly based on observed intakes in population groups. Large variability was observed, and it is unlikely that these differences can be explained by differences in climate, activity level and/or culture. This suggests that there are uncertainties in the methodologies used to assess water intake from food and fluids, including all types of beverages. To determine current methods for recording and reporting total water, beverages and fluid intakes, twenty-one European countries were surveyed using an electronic questionnaire. In total, twelve countries responded and ten completed surveys were summarised. Countries reported that their survey was representative of the population in terms of age and socio-economic status. However, a variety of methods were used - that is, repeated 24-h recalls, estimated food diaries and FFQ. None of the methods were validated to assess water and fluid intakes. The methods used to record liquid foods - for example, soup and diluted drinks - were inconsistent. Clarity and consistency on definitions of categories of beverages to facilitate comparisons between countries are needed. Recommendations for a unified approach to surveying and quantifying intake of water from fluids and foods are proposed.

Relationship of drinking water disinfectants to plasma cholesterol and thyroid hormone levels in experimental studies.

PubMed Central

Revis, N W; McCauley, P; Bull, R; Holdsworth, G

1986-01-01

The effects of drinking water containing 2 or 15 ppm chlorine (pH 6.5 and 8.5), chlorine dioxide, and monochloramine on thyroid function and plasma cholesterol were studied because previous investigators have reported cardiovascular abnormalities in experimental animals exposed to chlorinated water. Plasma thyroxine (T4) levels, as compared to controls, were significantly decreased in pigeons fed a normal or high-cholesterol diet and drinking water containing these drinking water disinfectants at a concentration of 15 ppm (the exception was chlorine at pH 6.5) for 3 months. In most of the treatment groups, T4 levels were significantly lower following the exposure to drinking water containing the 2 ppm dose. Increases in plasma cholesterol were frequently observed in the groups with lower T4 levels. This association was most evident in pigeons fed the high-cholesterol diet and exposed to these disinfectants at a dose of 15 ppm. For example, after 3 months of exposure to deionized water or water containing 15 ppm monochloramine, plasma cholesterol was 1266 +/- 172 and 2049 +/- 212 mg/dl, respectively, a difference of 783 mg/dl. The factor(s) associated with the effect of these disinfectants on plasma T4 and cholesterol is not known. We suggest however that these effects are probably mediated by products formed when these disinfectants react with organic matter in the upper gastrointestinal tract. PMID:3456597

The impact of dietary protein levels on nutrient digestibility and water and nitrogen balances in eventing horses.

PubMed

Oliveira, C A A; Azevedo, J F; Martins, J A; Barreto, M P; Silva, V P; Julliand, V; Almeida, F Q

2015-01-01

This study was performed to evaluate the impact of dietary protein levels on nutrient digestibility and water and nitrogen balances in conditioning eventing horses. Twenty-four Brazilian Sport Horses, male and female (8.0 to 15.0 yr; 488 ± 32 kg BW), were used in a randomized design with 4 levels of CP diets: 7.5%, 9.0%, 11.0%, and 13.0%. A digestion assay was performed with partial feces collection over 4 d, followed by 1 d of total urine collection. Data were submitted to regression analysis and adjusted to linear and quadratic models (P < 0.05). No differences were observed in the intake of DM, OM, EE, ADF, and NDF as a function of dietary protein levels. Dry matter intake average was 1.7% of BW. CP and N intake showed a linear increase as a function of increasing protein level in diets. A quadratic response (P < 0.05) was observed on the CP and NDF digestibility coefficients, with the maximum estimated level of digestibility at 11.6% and 11.4% CP in the diet, respectively. There was a linear effect on ADF digestibility coefficients, digestible DM and protein intake, and CP/DE ratio according to dietary protein levels. There was no impact of dietary protein levels on daily water intake, total water intake, or fecal water excretion. Urinary excretion values showed a linear increase in response to increased dietary protein levels, but no impact was observed on water balance, with an average of 8.4 L/d. Nitrogen intake (NI), N absorption (NA), and urinary N increased linearly as a function of increasing dietary protein levels. There was no impact of dietary protein levels on N retention (NR), with an average of 7.5 g N/d. Nitrogen retention as a percentage of NI or NA showed no significant changes in the function of dietary protein levels. There was an impact of dietary protein levels on the digestibility coefficient of CP, NDF, ADF, and digestible protein intake on conditioning eventing horses. The 11.6% CP level in the diet provided an intake of 2.25 g CP/kg BW

Lake Storage Measurements For Water Resources Management: Combining Remotely Sensed Water Levels and Surface Areas

NASA Astrophysics Data System (ADS)

Brakenridge, G. R.; Birkett, C. M.

2013-12-01

Presently operating satellite-based radar altimeters have the ability to monitor variations in surface water height for large lakes and reservoirs, and future sensors will expand observational capabilities to many smaller water bodies. Such remote sensing provides objective, independent information where in situ data are lacking or access is restricted. A USDA/NASA (http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir/) program is performing operational altimetric monitoring of the largest lakes and reservoirs around the world using data from the NASA/CNES, NRL, and ESA missions. Public lake-level products from the Global Reservoir and Lake Monitor (GRLM) are a combination of archived and near real time information. The USDA/FAS utilizes the products for assessing international irrigation potential and for crop production estimates; other end-users study climate trends, observe anthropogenic effects, and/or are are involved in other water resources management and regional water security issues. At the same time, the Dartmouth Flood Observatory (http://floodobservatory.colorado.edu/), its NASA GSFC partners (http://oas.gsfc.nasa.gov/floodmap/home.html), and associated MODIS data and automated processing algorithms are providing public access to a growing GIS record of the Earth's changing surface water extent, including changes related to floods and droughts. The Observatory's web site also provide both archival and near real time information, and is based mainly on the highest spatial resolution (250 m) MODIS bands. Therefore, it is now possible to provide on an international basis reservoir and lake storage change measurements entirely from remote sensing, on a frequently updating basis. The volume change values are based on standard numerical procedures used for many decades for analysis of coeval lake area and height data. We provide first results of this combination, including prototype displays for public access and data retrieval of water storage

Geographical mapping of fluoride levels in drinking water sources in Nigeria.

PubMed

Akpata, Enosakhare S; Danfillo, I S; Otoh, E C; Mafeni, J O

2009-12-01

Knowledge of fluoride levels in drinking water is of importance in dental public health, yet this information is lacking, at national level, in Nigeria. To map out fluoride levels in drinking water sources in Nigeria. Fluoride levels in drinking water sources from 109 randomly selected Local Government Areas (LGAs) in the 6 Nigerian geopolitical zones were determined. From the results, maps showing LGAs with fluoride concentrations exceeding 0.3 ppm, were drawn. ANOVA and t-test were used to determine the significance of the differences between the fluoride levels in the drinking water sources. Fluoride levels were low in most parts of the country, being 0.3 ppm or less in 62% of the LGAs. Fluoride concentrations were generally higher in North Central geopolitical zone, than the other zones in the country (p<0.05). In a few drinking water sources, fluoride concentrations exceeded 1.5 ppm, but was as high as 6.7 ppm in one well. Only 9% of the water sources were from waterworks. Most of the water sources in Nigeria contained low fluoride levels; but few had excessive concentrations and need to be partially defluoridated, or else alternative sources of drinking water provided for the community.

Deteriorating water clarity in shallow waters: Evidence from long term MODIS and in-situ observations

NASA Astrophysics Data System (ADS)

Shi, Kun; Zhang, Yunlin; Zhu, Guangwei; Qin, Boqiang; Pan, Delu

2018-06-01

Water clarity (Secchi disk depth: SDD), as a proxy of water transparency, provides important information on the light availability to the water or lake ecosystem. Shallow lakes have been experienced dramatic environmental and climatic change. This study demonstrated using combination of long-term MODIS and in-situ measurements to track the dynamics of SDD with these environmental and climate changes in shallow water environments. We selected a typical turbid shallow Lake Taihu as our case study. Based on MODIS-Aqua data, an empirical model for estimating SDD was developed and validated. Subsequently, we employed the proposed model to derive the spatial and temporal SDD distribution patterns of Lake Taihu from 2003 to 2015. Combining MODIS-derived SDD time series of 2003-2015 and long-term in-situ SDD observations dated back to 1993, we elucidated SDD long-term variation trends and driving mechanism. Deteriorating water clarity from the long-term SDD observations indicated that Lake Taihu became more and more turbid and water quality was decreasing. Increasing in cyanobacterial bloom area, as a result of decreasing in wind speed and eutrophication, may partially be responsible for the decreasing trend. A predicted future decrease in the wind speed in Lake Taihu region could enhance the formation of cyanobacterial blooms and consequently lead to a further decrease in water clarity. This study suggested that coupling remote sensing monitoring and long-term in-situ observations could provide robust evidence and new insights to elucidate long-term dynamics in aquatic ecosystem evolution.

Estimating Impaired Waters on a County Level for Public Health Analysis

EPA Science Inventory

Assessing the population-level impact of water quality on health can be difficult. Water quality data are measured at a watershed level and health data are organized at different levels of aggregation. To address this discrepancy and enable the consideration of water quality for ...

Water-level altitudes 2004 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2003 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

USGS Publications Warehouse

Kasmarek, Mark C.; Lanning-Rush, Jennifer

2004-01-01

This report is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District. For the Chicot and Evangeline aquifers, maps show approximate water-level altitudes in 2004, water-level changes from 2003 to 2004, approximate water-level changes from 1977 to 2004, and approximate water-level changes from 1990 to 2004 (figs. 1, 2, 3, 4, 5, 6, 7, 8). For the Jasper aquifer, maps show approximate water-level altitudes in 2004 and water-level changes from 2003 to 2004 and 2000 to 2004 (figs. 9, 10, 11). The report also contains a map showing borehole extensometer (well equipped with compaction monitor) site locations (fig. 12) and graphs showing measured compaction of subsurface material at these sites from 1973 or later to 2003 (fig. 13). The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979; and annual reports of same for the Fort Bend subregion (Fort Bend County and adjacent areas) since 1990. The USGS published its first water-level-altitude map for the Jasper aquifer in the greater Houston area (primarily Montgomery County) in 2001. The 2004 water-level-altitude and water-level-change maps for the three aquifers are included in this report.

Ground-water-quality and ground-water-level data, Bernalillo County, central New Mexico, 1990-1993

USGS Publications Warehouse

Kues, G.E.; Garcia, B.M.

1995-01-01

Ground-water-quality and ground-water-level data were collected in four unincorporated areas of Bernalillo County during 1990-93. Twenty wells in the east mountain area of Bernalillo County were sampled approximately monthly between January 1990 and June 1993. The water samples were analyzed for concentrations of chloride and selected nutrient species; many of the samples also were analyzed for concentrations of total organic carbon and dissolved boron and iron. Eleven wells northeast of the city of Albuquerque, 20 wells in the Rio Grande Valley immediately north of Albuquerque, and 30 wells in the Rio Grande Valley immediately south of Albuquerque were sampled once each between December 1992 and September 1993; all water samples were analyzed for chloride and selected nutrient species, and selected samples from wells in the north and south valley areas were also analyzed for major dissolved constituents, iron, manganese, and methylene blue active substances. Samples from 10 of the wells in the north and south valley areas were analyzed for 47 selected pesticides. Field measurements of specific conductance, pH, temperature, and alkalinity were made on most samples at the time of sample collection. Water levels also were measured at the time of sample collection when possible. Results of the monthly water-quality and water-level monitoring in the east mountain area of Bernalillo County are presented in graphical form. Water-quality and water-level data collected from the other areas are presented in tabular form.

Wave Height and Water Level Variability on Lakes Michigan and St Clair

DTIC Science & Technology

2012-10-01

Observations: http://www.ssec.wisc.edu/sose/glwx_activity.html 4. NASA Atlas of Extratropical Storm Tracks: http://data.giss.nasa.gov/stormtracks...term meteorological, ice, wave, and water level measurements. 15. SUBJECT TERMS Base flood elevation Coastal flood Extratropical storms Great...Box 1027 Detroit, MI 48231-1027 ERDC/CHL TR-12-23 ii Abstract The Great Lakes are subject to coastal flooding as a result of severe storms

Copper and zinc levels in soil, water, wheat, and hair of inhabitants of three areas of the Orenburg region, Russia.

PubMed

Salnikova, Elena V; Burtseva, Tatiana I; Skalnaya, Margarita G; Skalny, Anatoly V; Tinkov, Alexey A

2018-06-07

The objective of the present study was to assess the level of zinc and copper in soil, water, wheat and hair of inhabitants of the western, central, and eastern areas of the Orenburg region. A total of 525 water, soil, and wheat samples, as well as 420 hair samples were assessed using atomic absorption spectrometry (water, soil, wheat) and inductively-coupled plasma mass spectrometry (hair). The highest levels of Zn and Cu in water (4.9(4.2-5.1) and 1.0(0.9-1.1) mg/l), soil (23.8(20.7-27.0) and 2.6(1.9-3.1) mg/kg), and wheat (24.7(20.5-31.0) and 4.8(4.2-5.5) mg/kg) were observed in the eastern area (p < 0.001). Hair zinc levels in inhabitants of the western (184(165-198) µg/g) and eastern (224(211-253) µg/g) areas of the region exceeded the respective values from the central area by 32% and 61% (p < 0.001). In turn, hair Cu levels in the central (16.4(14.3-17.8) µg/g) and eastern (17.9(16.4-19.0) µg/g) areas exceeded the values from the western area by 10% and 20%, respectively. Correlation analysis demonstrated that hair Zn levels were positively correlated with water and soil content, whereas wheat Zn levels were associated with soil and water content. For copper significant direct correlation was observed only between soil and water Cu content. In multiple regression models, only water zinc level was significantly associated with hair Zn content, although the general model accounted for 55% of variability of hair Zn content. Higher zinc and copper exposure in the eastern area is presumably associated with higher activity of metal-processing industry. Copyright © 2018 Elsevier Inc. All rights reserved.

Water-level altitudes 2001, water-level changes 1977-2001 and 2000-2001, and compaction 1973-2000 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

USGS Publications Warehouse

Coplin, L.S.; Houston, Natalie A.; Brown, Dexter W.

2001-01-01

This report is one in an annual series of reports that depicts water-level altitudes and water-level changes since 1977 and compaction since 1973 in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report, prepared in cooperation with the City of Houston and the Harris-Galveston Coastal Subsidence District, presents maps for the Chicot and Evangeline aquifers showing the approximate water-level altitudes in wells in 2001 (figs 1,4) and approximate water-level changes in wells from 1977 to 2001 and from 2000 to 2001 (figs 2,3,5,6), a map showing extensometer site locations (fig. 7), and graphs showing measured compaction of subserface material at selected sites from 1973 to 2000 (fig. 8). The most recent previously published water-level-altitude maps and water-level-change maps for the two aquifers in the region are by Coplin and Santos. (2000). The Houston-Galveston region comprises Harris and Galveston Counties and adjacent parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties.

Enrichment of free-living amoebae in biofilms developed at upper water levels in drinking water storage towers: An inter- and intra-seasonal study.

PubMed

Taravaud, Alexandre; Ali, Myriam; Lafosse, Bernard; Nicolas, Valérie; Féliers, Cédric; Thibert, Sylvie; Lévi, Yves; Loiseau, Philippe M; Pomel, Sébastien

2018-08-15

Free-living amoebae (FLA) are ubiquitous organisms present in various natural and artificial environments, such as drinking water storage towers (DWST). Some FLA, such as Acanthamoeba sp., Naegleria fowleri, and Balamuthia mandrillaris, can cause severe infections at ocular or cerebral level in addition to being potential reservoirs of other pathogens. In this work, the abundance and diversity of FLA was evaluated in two sampling campaigns: one performed over five seasons in three DWST at three different levels (surface, middle and bottom) in water and biofilm using microscopy and PCR, and one based on the kinetics analysis in phase contrast and confocal microscopy of biofilm samples collected every two weeks during a 3-month period at the surface and at the bottom of a DWST. In the seasonal study, the FLA were detected in each DWST water in densities of ~20 to 25amoebaeL -1 . A seasonal variation of amoeba distribution was observed in water samples, with maximal densities in summer at ~30amoebaeL -1 and minimal densities in winter at ~16amoebaeL -1 . The FLA belonging to the genus Acanthamoeba were detected in two spring sampling campaigns, suggesting a possible seasonal appearance of this potentially pathogenic amoeba. Interestingly, a 1 log increase of amoebae density was observed in biofilm samples collected at the surface of all DWST compared to the middle and the bottom where FLA were at 0.1-0.2amoebae/cm 2 . In the kinetics study, an increase of amoebae density, total cell density, and biofilm thickness was observed as a function of time at the surface of the DWST, but not at the bottom. To our knowledge, this study describes for the first time a marked higher FLA density in biofilms collected at upper water levels in DWST, constituting a potential source of pathogenic micro-organisms. Copyright © 2018 Elsevier B.V. All rights reserved.

Rural water supply in Kerala, India: How to emerge from a low-level equilibrium trap

NASA Astrophysics Data System (ADS)

Singh, Bhanwar; Ramasubban, Radhika; Bhatia, Ramesh; Briscoe, John; Griffin, Charles C.; Kim, Chongchun

1993-07-01

Large quantities of financial and human resources have been devoted to improving rural water supplies in developing countries over the past two decades. Many projects have been successful, but many have failed to meet the needs of the intended beneficiaries. Evidence of the failures lies in the unused and poorly maintained systems that are scattered throughout rural areas of the developing world. The current situation in water supply in rural Kerala, India, reflects this general observation and can be described as a "low-level equilibrium trap." Water systems provide a low level of service with few yard taps. The monthly tariff for water from household connections is low. With few connectors and low tariffs, little revenue is generated beyond subsidies provided by the government. The water authority can afford to maintain the system up to a level at which the reliability of service is low, forcing consumers to supplement piped water from traditional sources. This study analyzes contingent valuation data collected in three areas of Kerala to evaluate the possibility of lifting the system out of this trap. The analysis shows that by making a few critical policy changes, encouraging private connections and financing those connections through higher tariffs, the system can ratchet up to a "high-level equilibrium" in which there are many connectors, monthly revenues are greatly increased, and consumer welfare improves. Such a system would be better financed, making it possible to improve the reliability and quality of the service.

Estimating a Global Hydrological Carrying Capacity Using GRACE Observed Water Stress

NASA Astrophysics Data System (ADS)

An, K.; Reager, J. T.; Famiglietti, J. S.

2013-12-01

Global population is expected to reach 9 billion people by the year 2050, causing increased demands for water and potential threats to human security. This study attempts to frame the overpopulation problem through a hydrological resources lens by hypothesizing that observed groundwater trends should be directly attributed to human water consumption. This study analyzes the relationships between available blue water, population, and cropland area on a global scale. Using satellite data from NASA's Gravity Recovery and Climate Experiment (GRACE) along with land surface model data from the Global Land Data Assimilation System (GLDAS), a global groundwater depletion trend is isolated, the validity of which has been verified in many regional studies. By using the inherent distributions of these relationships, we estimate the regional populations that have exceeded their local hydrological carrying capacity. Globally, these populations sum to ~3.5 billion people that are living in presently water-stressed or potentially water-scarce regions, and we estimate total cropland is exceeding a sustainable threshold by about 80 million km^2. Key study areas such as the North China Plain, northwest India, and Mexico City were qualitatively chosen for further analysis of regional water resources and policies, based on our distributions of water stress. These case studies are used to verify the groundwater level changes seen in the GRACE trend . Tfor the many populous, arid regions of the world that have already begun to experience the strains of high water demand.he many populous, arid regions of the world have already begun to experience the strains of high water demand. It will take a global cooperative effort of improving domestic and agricultural use efficiency, and summoning a political will to prioritize environmental issues to adapt to a thirstier planet. Global Groundwater Depletion Trend (Mar 2003-Dec 2011)

Water vapor in Titan's atmosphere observed by Cassini/CIRS data

NASA Astrophysics Data System (ADS)

Cottini, V.; Nixon, C. A.; Jennings, D. E.; Teanby, N. A.; Anderson, C. M.; Irwin, P. G.; Flasar, F. M.

2011-12-01

Water vapor in Titan's atmosphere has only been detected by whole-disk observations from the Infrared Space Observatory [1]. In fact an earlier attempt to measure water vapor with NASA's Cassini Composite Infrared Spectrometer (CIRS, [2]) was unsuccessful, due to poor signal-to-noise in early versions of the calibration pipeline. In this paper we show the detection of the water vapor in Titan's atmosphere through the analysis of the emission lines present in the spectral range (60 - 300 cm-1) observed by the far-IR Focal Plane 1 (FP1) detector. We model high spectral resolution (0.5 cm-1) disk versus limb data to determine the water mixing ratio as a function of latitude and time (using data acquired from December 2004 to late 2011), also exploring differences between the leading and trailing side of Saturn's moon. The opacity sources in the atmospheric model include thermal emission from the moon, collision-induced absorption (CIA) from pairs of Titan's main atmospheric molecules, the stratospheric aerosol and emission lines from atmospheric gases across the FP1 spectral range (see Cottini et al., 2011 [3] for description of the model). The radiative transfer model and retrieval code (NEMESIS) is based on the method of optimal estimation to perform a correlated-k computation of synthetic spectra.Our determination of the atmospheric abundance of water vapor yields a value of ~0.14 ppb assuming a constant vertical profile, which corresponds to a column abundance of 4.3x1014 molecules/cm2. Preliminary results suggest a change in the atmospheric water vapour abundance during northern winter into early northern spring. We also detected water in CIRS high resolution limb spectra. Modeling these limb observations, mainly centered on two tangent heights, 125 and 225 km, allows us to constrain the water vapor abundance vertical profile; utilizing the limb data allows us to retrieve the water vapor from disk observations using a water vapor mixing ratio that varies in

Reservoir water level drawdown as a novel, substantial, and manageable control on methane release to the atmosphere

NASA Astrophysics Data System (ADS)

Harrison, J.; Deemer, B. R.; Birchfield, M. K.

2014-12-01

Reservoirs constitute a globally important source of atmospheric methane (CH4). Although it is reasonably well-established that hydrostatic and barometric pressure can influence rates of CH4 release from lake and tidal sediments, the relationship between water-level manipulation and CH4 release from man-made impoundments has not been quantified or characterized. Furthermore, cross-system controls on CH4 production and release to the atmosphere have not been established. We collected CH4 emission (diffusion and ebullition) data for 8 reservoirs in the U.S. Pacific Northwest that are subject to a range of trophic conditions and water level management regimes. Our aim was to: (1) characterize CH4 emissions from these systems, and (2) quantify effects of water level management and eutrophication on CH4 fluxes. Results indicate very high fluxes, in some cases the highest reported reservoir emission rates, and a strong correspondence between lake level reduction and CH4 emissions, including quantitatively important bursts of CH4 bubbling. In one reservoir, drawdown-associated CH4 fluxes accounted for over 25% of annual CH4 emissions in a period of just 16 days (4% of the year). Average CH4 ebullition rates in a reservoir managed for hydropower peaking were nearly three-fold higher than in a paired upstream reservoir managed to maintain a constant water level (528 mg CH4 m-2 d-1 and 187 mg CH4 m-2 d-1 respectively). Highest gas fluxes were observed during the water level drawdown component of the hydropower peaking cycle (14.3 g CH4 m-2 d-1). In addition we observe a strong, positive relationship between eutrophication (as indicated by surface Chl a concentrations) and CH4 production (r2 = 0.88; P<0.001) and between eutrophication and the sensitivity of CH4 emissions to drawdown (r2 = 0.84; P<0.001). This work suggests that manipulation of water levels can significantly affect CH4 emissions from reservoirs to the atmosphere, and that sampling programs that miss drawdown

Ground-water levels in Huron County, Michigan, January 1996 through December 1996

USGS Publications Warehouse

Sweat, M.J.

1997-01-01

In 1990, the U.S. Geological Survey (USGS) completed a study of the hydrogeology of Huron County, Michigan (Sweat, 1991). In 1993, Huron County and the USGS entered into an agreement to continue collecting water levels at selected wells throughout Huron County. As part of the agreement, the USGS has provided training and instrumentation for County personnel to measure, on a quarterly basis, the depth to water below the land surface in selected wells. The agreement includes the operation of continuous water-level recorders installed on four wells in Bingham, Fairhaven, Grant and Lake Townships (fig. 1). County personnel make quarterly water-level measurements of 22 other wells. Once each year, County personnel are accompanied by USGS personnel who provide a quality assurance/quality control check of all measurements being made.Precipitation and the altitude of Lake Huron are good indicators of general climatic conditions and, therefore, provide an environmental context for ground-water levels in Huron County. Figure 2 shows the mean monthly water-level altitude of Lake Huron, averaged from measurements made by U.S. Army Corps of Engineers at two sites, and mean monthly precipitation as recorded in Huron County, for the period October 1988 through December 1996. In general, Lake Huron water levels in 1996 were about the same as they were from 1992-94 (NOAA, 1988-96). Precipitation was generally within the normal range, but was lower than 1993 or 1994. Rainfall during May, June, and July was, cumulatively, about 8.5 inches less in 1995 than in 1994.Hydrographs are presented for each of four wells with water-level recorders. Quarterly water-level measurements and range of water levels during 1996 for the other 22 wells are shown graphically and tabulated.In general, water levels in the glaciofluvial aquifer reflect seasonal variations, with maximum depths to water occurring in late summer and early fall and minimum depths to water occurring in late winter and early

Monitoring of Low-Level Virus in Natural Waters

PubMed Central

Sorber, Charles A.; Sagik, Bernard P.; Malina, Joseph F.

1971-01-01

The insoluble polyelectrolyte technique for concentrating virus is extended to extremely low virus levels. The effectiveness of this method employing a coliphage T2 model is a constant 20% over a range of virus levels from 103 to 10−4 plaque-forming units/ml. The efficiency of the method is dependent upon pH control during the concentration phase. Although the study was initiated to develop a method for quantitating the effectiveness of water and wastewater treatment methods for the removal of viruses from waters at low concentrations, the potential of the technique for efficient monitoring of natural waters is apparent. PMID:4940873

Wetland Resiliency: How does multi-year water table level decline and recovery influence carbon dioxide and methane fluxes?

NASA Astrophysics Data System (ADS)

Pugh, C.; Reed, D. E.; Desai, A. R.; Sulman, B. N.

2016-12-01

Wetlands play a disproportionately large role in the global carbon budget, and individual wetlands can fluctuate between carbon sinks and sources depending on factors such as hydrology, biogeochemistry, and land use. Although much research has been done on wetland biogeochemical cycles, there is a lack of experimental evidence concerning how changes in wetland hydrology influence these cycles over interannual timescales. Over a seven-year period, Sulman et al. (2009) found that a drought-induced declining water table at a shrub wetland in northern Wisconsin coincided with increased ecosystem respiration (ER) and gross ecosystem productivity (GEP) (Sulman et al. 2009). Since then, however, the average water table level at this site has begun to increase, thus allowing a unique opportunity to explore how wetland carbon storage is impacted by water table recovery. With the addition of three more years of eddy covariance observations post recovery and new methane flux observations, we found that water table level no longer had a significant correlation with GEP, ER, or methane flux. Air temperature, however, had a strong correlation with all three. Average methane flux stayed relatively constant under 14 °C, before increasing an order of magnitude from 3.7 nmol m-2 s-1 in April to 36 nmol m-2 s-1 in July. These results suggest that, over decadal timescales, temperature, rather than water level, is a stronger limiting factor for both aerobic and anaerobic respiration in shrub fen wetlands. Wetlands play a disproportionately large role in the global carbon budget, and individual wetlands can fluctuate between carbon sinks and sources depending on factors such as hydrology, biogeochemistry, and land use. Although much research has been done on wetland biogeochemical cycles, there is a lack of experimental evidence concerning how changes in wetland hydrology influence these cycles over interannual timescales. Over a seven-year period, Sulman et al. (2009) found that a

Illinois ground-water observation network; a preliminary planning document for network design

USGS Publications Warehouse

Frost, L.R.; O'Hearn, Michael; Gibb, J.P.; Sherrill, M.G.

1984-01-01

Water-level and water-quality networks in Illinois were evaluated to determine the adequacy and completeness of available data bases. Ground-water data in present data bases are inadequate to provide information on ground-water quality and water levels in large areas of Illinois and in the major geohydrologic units underlying Illinois and surrounding areas. Data-management needs indicate that a new data base is desirable and could be developed by use of carefully selected available data and new data. Types of data needed to define ground-water quality and water levels in selected geohydrologic units were tentatively identified. They include data on concentrations of organic chemicals related to activities of man, and concentrations of inorganic chemicals which relate either to man 's activities or to the chemical composition of the source aquifer. Water-level data are needed which can be used to describe short- and long-term stresses on the ground-water resources of Illinois. Establishment of priorities for data collection has been deferred until existing hydrologic data files can be stored for usable data and until input from other local, State, and Federal agencies can be solicited and compiled. (USGS)

Energy-Water Nexus: Balancing the Tradeoffs between Two-Level Decision Makers

DOE PAGES

Zhang, Xiaodong; Vesselinov, Velimir Valentinov

2016-09-03

Energy-water nexus has substantially increased importance in the recent years. Synergistic approaches based on systems-analysis and mathematical models are critical for helping decision makers better understand the interrelationships and tradeoffs between energy and water. In energywater nexus management, various decision makers with different goals and preferences, which are often conflicting, are involved. These decision makers may have different controlling power over the management objectives and the decisions. They make decisions sequentially from the upper level to the lower level, challenging decision making in energy-water nexus. In order to address such planning issues, a bi-level decision model is developed, which improvesmore » upon the existing studies by integration of bi-level programming into energy-water nexus management. The developed model represents a methodological contribution to the challenge of sequential decisionmaking in energy-water nexus through provision of an integrated modeling framework/tool. An interactive fuzzy optimization methodology is introduced to seek a satisfactory solution to meet the overall satisfaction of the two-level decision makers. The tradeoffs between the two-level decision makers in energy-water nexus management are effectively addressed and quantified. Application of the proposed model to a synthetic example problem has demonstrated its applicability in practical energy-water nexus management. Optimal solutions for electricity generation, fuel supply, water supply including groundwater, surface water and recycled water, capacity expansion of the power plants, and GHG emission control are generated. In conclusion, these analyses are capable of helping decision makers or stakeholders adjust their tolerances to make informed decisions to achieve the overall satisfaction of energy-water nexus management where bi-level sequential decision making process is involved.« less

Energy-Water Nexus: Balancing the Tradeoffs between Two-Level Decision Makers

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

Zhang, Xiaodong; Vesselinov, Velimir Valentinov

Energy-water nexus has substantially increased importance in the recent years. Synergistic approaches based on systems-analysis and mathematical models are critical for helping decision makers better understand the interrelationships and tradeoffs between energy and water. In energywater nexus management, various decision makers with different goals and preferences, which are often conflicting, are involved. These decision makers may have different controlling power over the management objectives and the decisions. They make decisions sequentially from the upper level to the lower level, challenging decision making in energy-water nexus. In order to address such planning issues, a bi-level decision model is developed, which improvesmore » upon the existing studies by integration of bi-level programming into energy-water nexus management. The developed model represents a methodological contribution to the challenge of sequential decisionmaking in energy-water nexus through provision of an integrated modeling framework/tool. An interactive fuzzy optimization methodology is introduced to seek a satisfactory solution to meet the overall satisfaction of the two-level decision makers. The tradeoffs between the two-level decision makers in energy-water nexus management are effectively addressed and quantified. Application of the proposed model to a synthetic example problem has demonstrated its applicability in practical energy-water nexus management. Optimal solutions for electricity generation, fuel supply, water supply including groundwater, surface water and recycled water, capacity expansion of the power plants, and GHG emission control are generated. In conclusion, these analyses are capable of helping decision makers or stakeholders adjust their tolerances to make informed decisions to achieve the overall satisfaction of energy-water nexus management where bi-level sequential decision making process is involved.« less

Lake-level variability and water availability in the Great Lakes

USGS Publications Warehouse

Wilcox, Douglas A.; Thompson, Todd A.; Booth, Robert K.; Nicholas, J.R.

2007-01-01

In this report, we present recorded and reconstructed (pre-historical) changes in water levels in the Great Lakes, relate them to climate changes of the past, and highlight major water-availability implications for storage, coastal ecosystems, and human activities. 'Water availability,' as conceptualized herein, includes a recognition that water must be available for human and natural uses, but the balancing of how much should be set aside for which use is not discussed. The Great Lakes Basin covers a large area of North America. The lakes capture and store great volumes of water that are critical in maintaining human activities and natural ecosystems. Water enters the lakes mostly in the form of precipitation and streamflow. Although flow through the connecting channels is a primary output from the lakes, evaporation is also a major output. Water levels in the lakes vary naturally on timescales that range from hours to millennia; storage of water in the lakes changes at the seasonal to millennial scales in response to lake-level changes. Short-term changes result from storm surges and seiches and do not affect storage. Seasonal changes are driven by differences in net basin supply during the year related to snowmelt, precipitation, and evaporation. Annual to millennial changes are driven by subtle to major climatic changes affecting both precipitation (and resulting streamflow) and evaporation. Rebounding of the Earth's surface in response to loss of the weight of melted glaciers has differentially affected water levels. Rebound rates have not been uniform across the basin, causing the hydrologic outlet of each lake to rise in elevation more rapidly than some parts of the coastlines. The result is a long-term change in lake level with respect to shoreline features that differs from site to site. The reconstructed water-level history of Lake Michigan-Huron over the past 4,700 years shows three major high phases from 2,300 to 3,300, 1,100 to 2,000, and 0 to 800

Comparison of 1972 and 1996 water levels in the Goleta central ground-water subbasin, Santa Barbara County, California

USGS Publications Warehouse

Kaehler, Charles A.; Pratt, David A.; Paybins, Katherine S.

1997-01-01

Ground-water levels for 1996 were compared with 1972 water levels to determine if a "drought buffer" currently exists. The drought buffer was defined previously, in a litigated settlement involving the Goleta Water District, as the 1972 water level in the Central ground-water subbasin. To make this deter mination, a network of 15 well sites was selected, water levels were measured monthly from April through December 1996, and the 1996 water-level data were compared with1972 data. The study was done in cooperation with the Goleta Water District. The 1972-1996 water-level-altitude changes for corresponding months of the comparison years were averaged for each network well. These averaged changes ranged from a rise of 9.4 ft for well 2N2 to a decline of 45.0 ft for well 8K8. The results of the comparison indicate a rise in water level at 1 site (well 2N2) and a decline at 14 sites. The mean of the 14 negative average values was a decline of 24.0 ft. The altitude of the bottom of well 2N2 was higher than the bottom altitudes at the other network sites, and this well is located a few feet from a fault that acts as a hydrologic barrier. The results of the water-level comparison for the Central subbasin were influenced to some unknown degree by the areal distribution of the set of wells selected for the network and the vertical dis tribution of the perforated intervals of the wells. For this reason, the mean water-level change--a decline of 21.8 ft--calculated from the averages of the month-to-month changes for the 15 network sites, should be used with caution. In addition, the number of usable individual monthly comparison measurements available for an individual site ranged from one to nine, and averaged six. Therefore, a weighted mean of the monthly averages was calculated on the basis of the number of comparison measurements available for each site. The weighted mean is a decline of 20.9 ft. All Central subbasin wells that were idle (that is, were not being pumped

Water-level altitudes 2005 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2004 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

USGS Publications Warehouse

Kasmarek, Mark C.; Houston, Natalie A.

2005-01-01

This report is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District. For the Chicot and Evangeline aquifers, maps show approximate water-level altitudes in 2005, water-level changes from 2004 to 2005, and approximate water-level changes from 2000 to 2005, from 1990 to 2005, and from 1977 to 2005 (figs. 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10). For the Jasper aquifer, maps show approximate water-level altitudes in 2005 and water-level changes from 2004 to 2005 and 2000 to 2005 (figs. 11, 12, and 13). The report also contains a map showing borehole extensometer (well equipped with compaction monitor) site locations (fig. 14) and graphs showing measured compaction of subsurface material at these sites from 1973 or later to 2004 (fig. 15).The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979; and annual reports of same for the Fort Bend subregion (Fort Bend County and adjacent areas) since 1990. The USGS published its first water-level-altitude map for the Jasper aquifer in the greater Houston area (primarily Montgomery County) in 2001. The 2005 water-level-altitude and water-level-change maps for the three aquifers are included in this report.

Water-level altitudes 2006 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2005 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

USGS Publications Warehouse

Kasmarek, Mark C.; Houston, Natalie A.; Brown, Dexter W.

2006-01-01

This report is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District. For the Chicot and Evangeline aquifers, maps show approximate water-level altitudes in 2006, water-level changes from 2005 to 2006, and approximate water-level changes from 2001 to 2006, from 1990 to 2006, and from 1977 to 2006 (figs. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10). For the Jasper aquifer, maps show approximate water-level altitudes in 2006 and water-level changes from 2005 to 2006 and 2000 to 2006 (figs. 11, 12, 13). The report also contains a map showing borehole extensometer (well equipped with compaction monitor) site locations (fig. 14) and graphs showing measured compaction of subsurface material at these sites from 1973 or later to 2005 (fig. 15).The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979; and annual reports of same for the Fort Bend subregion (Fort Bend County and adjacent areas) since 1990. The USGS published its first water-level-altitude map for the Jasper aquifer in the greater Houston area (primarily Montgomery County) in 2001. The 2006 water-level-altitude and water-level-change maps for the three aquifers are included in this report.

Water resources data for Texas, water year 1993. Volume 4. Ground-water data. Water-data report (Annual), 1 October 1992-30 September 1993

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

Gandara, S.C.; Jones, R.E.

1993-11-01

Water-resources data for the 1993 water year for Texas consists of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 4 contains water levels for 771 observation wells and water-quality data for 226 monitoring wells.

Water resources data for Texas, water year 1996. Volume 4. Ground-water data. Water-data report (Annual), 1 October 1995-30 September 1996

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

Gandara, S.C.; Jones, R.E.; Barbie, D.L.

1996-11-22

Water-resources data for the 1996 water year for Texas consists of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 4 contains water levels for 845 observation wells and 187 water-quality data for monitoring wells.

Water resources data for Texas, water year 1994. Volume 4. Ground-water data. Water-data report (Annual), 1 October 1993-30 September 1994

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

Gandara, S.C.; Jones, R.E.

1994-12-12

Water-resources data for the 1994 water year for Texas consists of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 4 contains water levels for 698 observation wells and water-quality data for 97 monitoring wells.

Water resources data for Texas, water year 1997. Volume 4. Ground-water data. Water-data report (Annual), 1 October 1996-30 September 1997

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

Gandara, S.C.; Jones, R.E.; Barbie, D.L.

1997-12-03

Water-resources data for the 1997 water year for Texas consists of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 4 contains water levels for 790 observation wells and 245 water-quality data for monitoring wells.

Water resources data for Texas, water year 1995. Volume 4. Ground-water data. Water-data report (Annual), 1 October 1994-30 September 1995

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

Gandara, S.C.; Jones, R.E.

1995-12-18

Water-resources data for the 1995 water year for Texas consists of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 4 contains water levels for 919 observation wells and 226 water-quality data for monitoring wells.

An integrated investigation of lake storage and water level changes in the Paiku Co basin, central Himalayas

NASA Astrophysics Data System (ADS)

Lei, Yanbin; Yao, Tandong; Yang, Kun; Bird, Broxton W.; Tian, Lide; Zhang, Xiaowen; Wang, Weicai; Xiang, Yang; Dai, Yufeng; Lazhu; Zhou, Jing; Wang, Lei

2018-07-01

Since the late 1990s, lakes in the southern Tibetan Plateau (TP) have shrunk considerably, which contrasts with the rapid expansion of lakes in the interior TP. Although these spatial trends have been well documented, the underlying hydroclimatic mechanisms are not well understood. Since 2013, we have carried out comprehensive water budget observations at Paiku Co, an alpine lake in the central Himalayas. In this study, we investigate water storage and lake level changes on seasonal to decadal time scales based on extensive in-situ measurements and satellite observations. Bathymetric surveys show that Paiku Co has a mean and maximum water depth of 41.1 m and 72.8 m, respectively, and its water storage was estimated to be 109.3 × 108 m3 in June 2016. On seasonal scale between 2013 and 2017, Paiku Co's lake level decreased slowly between January and May, increased considerably between June and September, and then decreased rapidly between October and January. On decadal time scale, Paiku Co's lake level decreased by 3.7 ± 0.3 m and water storage reduced by (10.2 ± 0.8) × 108 m3 between 1972 and 2015, accounting for 8.5% of the total water storage in 1972. This change is consistent with a trend towards drier conditions in the Himalaya region during the recent decades. In contrast, glacial lakes within Paiku Co's basin expanded rapidly, indicating that, unlike Paiku Co, glacial meltwater was sufficient to compensate the effect of the reduced precipitation.

Water-Level Conditions in Selected Confined Aquifers of the New Jersey and Delaware Coastal Plain, 2003

USGS Publications Warehouse

dePaul, Vincent T.; Rosman, Robert; Lacombe, Pierre J.

2009-01-01

underlying the southern part of the peninsula remained about the same as in 1998. To the south, recoveries up to 8 feet were observed in southern Lower Township as withdrawals had decreased since 1998. In the northern part of Cape May County, water levels had not changed substantially from historic conditions. In the Rio Grande water-bearing zone, water levels rose by as much as 13 ft at the Rio Grande well field; elsewhere across the aquifer, little change had occurred. In the Atlantic City 800-foot sand, water-level changes were greatest in southern Cape May County; at the Cape May desalination wells, water levels were as much as 32 ft lower in 2003 than in 1998. In contrast, water levels at the center of a regional cone of depression near Atlantic City rose by as much as 10 ft. Within the Piney Point aquifer water levels rose by 46 ft near Seaside Park. Similarly, water levels increased by more than 30 ft in and around the major cone of depression underlying Dover, Delaware. In the Vincentown aquifer, water levels stabilized or recovered by 2 ft to 6 ft from 1998 to 2003 in most of the wells measured; the exception is near Adelphia in Monmouth County, where water levels rose by as much as 18 ft. From 1998 to 2003, water levels near the center of a large cone of depression that extends from Monmouth to Ocean County recovered by as much as 20 ft in the Wenonah-Mount Laurel aquifer. Concurrently, ground-water levels within the Englishtown aquifer system declined by as much as 13 ft in the same area. Water levels across much of the Upper Potomac-Raritan-Magothy aquifer in the northern Coastal Plain remained about the same as 5 years previous, except in northern Ocean County where ground-water levels declined 10 ft to 33 ft. Water levels in the Middle Potomac-Raritan-Magothy aquifer declined from 5 to 9 ft along the border between Monmouth and Middlesex County. Elsewhere, across the northern part of the Coastal Plain, water levels stabilized within the Cretaceous-a

Observation and analysis of water inherent optical properties

NASA Astrophysics Data System (ADS)

Sun, Deyong; Li, Yunmei; Le, Chengfeng; Huang, Changchun

2008-03-01

Inherent optical property is an important part of water optical properties, and is the foundation of water color analytical model establishment. Through quantity filter technology (QFT) and backscattering meter BB9 (WETlabs Inc), absorption coefficients of CDOM, total suspended minerals and backscattering coefficients of total suspended minerals had been observed in Meiliang Bay of Taihu lake at summer and winter respectively. After analyzing the spectral characteristics of absorption and backscattering coefficients, the differences between two seasons had been illustrated adequately, and the reasons for the phenomena, which are related to the changes of water quality coefficient, had also been explained. So water environment states can be reflected by inherent optical properties. In addition, the relationship models between backscattering coefficients and suspended particle concentrations had been established, which can support coefficients for analytical models.

Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study.

PubMed

Manassaram, Deana M; Backer, Lorraine C; Messing, Rita; Fleming, Lora E; Luke, Barbara; Monteilh, Carolyn P

2010-10-14

Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affected methemoglobin levels during pregnancy. We also examined whether differences in water use practices existed among pregnant women based on household drinking water source of private vs. public supply. A longitudinal study of 357 pregnant women was conducted. Longitudinal regression models were used to examine changes and predictors of the change in methemoglobin levels over the period of gestation. Pregnant women showed a decrease in methemoglobin levels with increasing gestation although <1% had levels above the physiologic normal of 2% methemoglobin, regardless of the source of their drinking water. The multivariable analyses did not show a statistically significant association between methemoglobin levels and the estimated nitrate intake from tap water among pregnant women around 36 weeks gestation (β = 0.046, p = 0.986). Four women had tap water nitrate levels above the MCL of 10 mg/L. At enrollment, a greater proportion of women who reported using water treatment devices were private wells users (66%) compared to public system users (46%) (p < 0.0001). Also, a greater proportion of private well users (27%) compared to public system users (13%) were using devices capable of removing nitrate from water (p < 0.0001). Pregnant women potentially exposed to nitrate levels primarily below the MCL for drinking water were unlikely to show methemoglobin levels above the physiologic normal. Water use practices such as the use of treatment devices to remove nitrates varied according to water source and

Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study

PubMed Central

2010-01-01

Background Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affected methemoglobin levels during pregnancy. We also examined whether differences in water use practices existed among pregnant women based on household drinking water source of private vs. public supply. Methods A longitudinal study of 357 pregnant women was conducted. Longitudinal regression models were used to examine changes and predictors of the change in methemoglobin levels over the period of gestation. Results Pregnant women showed a decrease in methemoglobin levels with increasing gestation although <1% had levels above the physiologic normal of 2% methemoglobin, regardless of the source of their drinking water. The multivariable analyses did not show a statistically significant association between methemoglobin levels and the estimated nitrate intake from tap water among pregnant women around 36 weeks gestation (β = 0.046, p = 0.986). Four women had tap water nitrate levels above the MCL of 10 mg/L. At enrollment, a greater proportion of women who reported using water treatment devices were private wells users (66%) compared to public system users (46%) (p < 0.0001). Also, a greater proportion of private well users (27%) compared to public system users (13%) were using devices capable of removing nitrate from water (p < 0.0001). Conclusion Pregnant women potentially exposed to nitrate levels primarily below the MCL for drinking water were unlikely to show methemoglobin levels above the physiologic normal. Water use practices such as the use of treatment devices to remove

Use of inexpensive pressure transducers for measuring water levels in wells

USGS Publications Warehouse

Keeland, B.D.; Dowd, J.F.; Hardegree, W.S.

1997-01-01

Frequent measurement of below ground water levels at multiple locations is an important component of many wetland ecosystem studies. These measurements, however, are usually time consuming, labor intensive, and expensive. This paper describes a water-level sensor that is inexpensive and easy to construct. The sensor is placed below the expected low water level in a shallow well and, when connected to a datalogger, uses a pressure transducer to detect groundwater or surface water elevations. Details of pressure transducer theory, sensor construction, calibration, and examples of field installations are presented. Although the transducers must be individually calibrated, the sensors have a linear response to changing water levels (r2 ??? .999). Measurement errors resulting from temperature fluctuations are shown to be about 4 cm over a 35??C temperature range, but are minimal when the sensors are installed in groundwater wells where temperatures are less variable. Greater accuracy may be obtained by incorporating water temperature data into the initial calibration (0.14 cm error over a 35??C temperature range). Examples of the utility of these sensors in studies of groundwater/surface water interactions and the effects of water level fluctuations on tree growth are provided. ?? 1997 Kluwer Academic Publishers.

Levels and profiles of polychlorinated dibenzo-p-dioxin and dibenzofurans in raw and treated water from water treatment plants in Shenzhen, China.

PubMed

Lu, Feina; Jiang, Yousheng; Wu, Dongting; Zhou, Jian; Li, Shengnong; Zhang, Jianqing

2016-04-01

Levels and profiles of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) were analyzed for the first time in raw and treated water from five water treatment plants in Shenzhen, South China. The average PCDD/Fs concentrations were 32.93 pg/L (0.057 pg international toxic equivalent quantity (I-TEQ)/L) and 0.64 pg/L (0.021 pg I-TEQ/L) in raw and treated water, respectively. The removal rate of PCDD/Fs in terms of mass concentration varied from 93.4% to 98.8%, whereas a negative removal rate was observed in one plant in terms of TEQ concentration. The PCDD/Fs concentration in raw water was lower than most of the published data from other countries and regions, and the PCDD/Fs concentration in treated water was below the Maximum Contaminants Level (MCL) of 30 pg/L for dioxin in drinking water set by the US EPA. Historical pentachlorophenol usage, local waste incineration and industrial emissions, as well as surface runoff or even soil erosion, might be the main sources for PCDD/F pollution in water. The daily intake of PCDD/Fs for local residents from drinking water was estimated to be 0.69 fg I-TEQ/kg/day, which is negligible compared with that from food consumption (1.23 pg WHO-TEQ/kg/day) in the local area. Copyright © 2016 Elsevier Ltd. All rights reserved.

Observation of EAS using a large water tank

NASA Technical Reports Server (NTRS)

Inoue, K.; Sakuyama, H.; Suzuki, N.; Suzuki, T.

1985-01-01

Using a large water tank (30 m in diameter, 4.5 m in depth) transition of extensive air showers (EAS) was investigated at Taro (200 m above sea level). There are set 150,0.4 sq m proportional counters on the bottom of the water tank. A conventional EAS array of 25 plastic scintillation detectors was arranged within several tens meter from the water tank. A proportional counter (10x10x200 cc x2) is made of a square shaped pipe of iron. Tungsten wire (100 mu m phi) is stretched tight in the center of the counter. A gas mixture of 90% argon and 10% methane is used at 760 mmHg. About 3000 EAS were obtained through 1 m of water since 1984.

Ground-water levels in Huron County, Michigan, 2004-05

USGS Publications Warehouse

Weaver, T.L.; Crowley, S.L.; Blumer, S.P.

2006-01-01

In 1990, the U.S. Geological Survey (USGS) completed a study of the hydrogeology of Huron County, Michigan (Sweat, 1991). In 1993, Huron County and the USGS entered into a continuing agreement to measure water levels at selected wells throughout Huron County. As part of the agreement, USGS has operated four continuous water-level recorders, installed from 1988 to 1991 on wells in Bingham, Fairhaven, Grant, and Lake Townships (fig. 1) and summarized the data collected in an annual or bi-annual report. The agreement was altered in 2003, and beginning January 1, 2004, only the wells in Fairhaven and Lake Townships retained continuous waterlevel recorders, while the wells in Grant and Bingham Townships reverted primarily to periodic or quarterly measurement status. USGS also has provided training for County or Huron Conservation District personnel to measure the water level, on a quarterly basis, in 25 wells. USGS personnel regularly accompany County or Huron Conservation District personnel to provide a quality assurance/quality control check of all measurements being made. Water-level data collected from the 25 periodically or quarterly-measured wells is summarized in an annual or bi-annual report. In 1998, the USGS also completed a temporal and spatial analysis of the monitoring well network in Huron County (Holtschlag and Sweat, 1998). The altitude of Lake Huron and precipitation are good indicators of general climatic conditions and, therefore, provide an environmental context for ground-water levels in Huron County. Figure 2 shows the mean-monthly water-level altitude of Lake Huron, averaged from measurements made by the U.S. Army Corps of Engineers at sites near Essexville or Harbor Beach, or both (National Oceanic and Atmospheric Administration, 2003-05), and monthly precipitation measured in Bad Axe (National Oceanic and Atmospheric Administration, 2003-05). In March 2003, a new low-water level for the period from 1991 through 2005 was measured in Lake Huron

Semantic Data Integration and Ontology Use within the Global Earth Observation System of Systems (GEOSS) Global Water Cycle Data Integration System

NASA Astrophysics Data System (ADS)

Pozzi, W.; Fekete, B.; Piasecki, M.; McGuinness, D.; Fox, P.; Lawford, R.; Vorosmarty, C.; Houser, P.; Imam, B.

2008-12-01

The inadequacies of water cycle observations for monitoring long-term changes in the global water system, as well as their feedback into the climate system, poses a major constraint on sustainable development of water resources and improvement of water management practices. Hence, The Group on Earth Observations (GEO) has established Task WA-08-01, "Integration of in situ and satellite data for water cycle monitoring," an integrative initiative combining different types of satellite and in situ observations related to key variables of the water cycle with model outputs for improved accuracy and global coverage. This presentation proposes development of the Rapid, Integrated Monitoring System for the Water Cycle (Global-RIMS)--already employed by the GEO Global Terrestrial Network for Hydrology (GTN-H)--as either one of the main components or linked with the Asian system to constitute the modeling system of GEOSS for water cycle monitoring. We further propose expanded, augmented capability to run multiple grids to embrace some of the heterogeneous methods and formats of the Earth Science, Hydrology, and Hydraulic Engineering communities. Different methodologies are employed by the Earth Science (land surface modeling), the Hydrological (GIS), and the Hydraulic Engineering Communities; with each community employing models that require different input data. Data will be routed as input variables to the models through web services, allowing satellite and in situ data to be integrated together within the modeling framework. Semantic data integration will provide the automation to enable this system to operate in near-real-time. Multiple data collections for ground water, precipitation, soil moisture satellite data, such as SMAP, and lake data will require multiple low level ontologies, and an upper level ontology will permit user-friendly water management knowledge to be synthesized. These ontologies will have to have overlapping terms mapped and linked together. so

Spatial Heterodyne Observation of Water (SHOW) from a high altitude aircraft

NASA Astrophysics Data System (ADS)

Bourassa, A. E.; Langille, J.; Solheim, B.; Degenstein, D. A.; Letros, D.; Lloyd, N. D.; Loewen, P.

2017-12-01

The Spatial Heterodyne Observations of Water instrument (SHOW) is limb-sounding satellite prototype that is being developed in collaboration between the University of Saskatchewan, York University, the Canadian Space Agency and ABB. The SHOW instrument combines a field-widened SHS with an imaging system to observe limb-scattered sunlight in a vibrational band of water (1363 nm - 1366 nm). Currently, the instrument has been optimized for deployment on NASA's ER-2 aircraft. Flying at an altitude of 70, 000 ft the ER-2 configuration and SHOW viewing geometry provides high spatial resolution (< 500 m) limb-measurements of water vapor in the Upper troposphere and lower stratosphere region. During an observation campaign from July 15 - July 22, the SHOW instrument performed 10 hours of observations from the ER-2. This paper describes the SHOW measurement technique and presents the preliminary analysis and results from these flights. These observations are used to validate the SHOW measurement technique and demonstrate the sampling capabilities of the instrument.

Water Resources Data, California, Water Year 1989. Volume 5. Ground-Water Data

USGS Publications Warehouse

Lamb, C.E.; Johnson, J.A.; Fogelman, R.P.; Grillo, D.A.

1990-01-01

Water resources data for the 1989 water year for California consist of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in weils. Volume 5 contains water levels for 1,037 observation wells and water-quality data for 254 monitoring wells. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperatine State and Federal agencies in California.

Drinking cholera: salinity levels and palatability of drinking water in coastal Bangladesh.

PubMed

Grant, Stephen Lawrence; Tamason, Charlotte Crim; Hoque, Bilqis Amin; Jensen, Peter Kjaer Mackie

2015-04-01

To measure the salinity levels of common water sources in coastal Bangladesh and explore perceptions of water palatability among the local population to investigate the plausibility of linking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water. Hundred participants took part in a taste-testing experiment of water with varying levels of salinity. Salinity measurements were taken of both drinking and non-drinking water sources. Informal group discussions were conducted to gain an in-depth understanding of water sources and water uses. Salinity levels of non-drinking water sources suggest that the conditions for Vibrio cholerae survival exist 7-8 days within the local aquatic environment. However, 96% of participants in the taste-testing experiment reported that they would never drink water with salinity levels that would be conducive to V. cholerae survival. Furthermore, salinity levels of participant's drinking water sources were all well below the levels required for optimal survival of V. cholerae. Respondents explained that they preferred less salty and more aesthetically pleasing drinking water. Theoretically, V. cholerae can survive in the river systems in Bangladesh; however, water sources which have been contaminated with river water are avoided as potential drinking water sources. Furthermore, there are no physical connecting points between the river system and drinking water sources among the study population, indicating that the primary driver for cholera cases in Bangladesh is likely not through the contamination of saline-rich river water into drinking water sources. © 2015 John Wiley & Sons Ltd.

Selenium Speciation in the Fountain Creek Watershed (Colorado, USA) Correlates with Water Hardness, Ca and Mg Levels.

PubMed

Carsella, James S; Sánchez-Lombardo, Irma; Bonetti, Sandra J; Crans, Debbie C

2017-04-30

The environmental levels of selenium (Se) are regulated and strictly enforced by the Environmental Protection Agency (EPA) because of the toxicity that Se can exert at high levels. However, speciation plays an important role in the overall toxicity of Se, and only when speciation analysis has been conducted will a detailed understanding of the system be possible. In the following, we carried out the speciation analysis of the creek waters in three of the main tributaries-Upper Fountain Creek, Monument Creek and Lower Fountain Creek-located in the Fountain Creek Watershed (Colorado, USA). There are statistically significant differences between the Se, Ca and Mg, levels in each of the tributaries and seasonal swings in Se, Ca and Mg levels have been observed. There are also statistically significant differences between the Se levels when grouped by Pierre Shale type. These factors are considered when determining the forms of Se present and analyzing their chemistry using the reported thermodynamic relationships considering Ca 2+ , Mg 2+ , SeO₄ 2- , SeO₃ 2- and carbonates. This analysis demonstrated that the correlation between Se and water hardness can be explained in terms of formation of soluble CaSeO₄. The speciation analysis demonstrated that for the Fountain Creek waters, the Ca 2+ ion may be mainly responsible for the observed correlation with the Se level. Considering that the Mg 2+ level is also correlating linearly with the Se levels it is important to recognize that without Mg 2+ the Ca 2+ would be significantly reduced. The major role of Mg 2+ is thus to raise the Ca 2+ levels despite the equilibria with carbonate and other anions that would otherwise decrease Ca 2+ levels.

The Water Level Fall of Lake Megali Prespa (N Greece): an Indicator of Regional Water Stress Driven by Climate Change and Amplified by Water Extraction?

NASA Astrophysics Data System (ADS)

van der Schriek, Tim; Giannakopoulos, Christos

2014-05-01

Mediterranean wet-dry events during this period. There are robust indications for a link between lake level and the North Atlantic Oscillation, which is known to strongly influence Mediterranean winter precipitation. Hydro-climatic records show a complicated picture, but tentatively support the conclusion that the unprecedented lake level fall is principally related to climate change. The available fluvial discharge record and most existing snowfall records show statistically significant decreases in annual averages. Annual rainfall only shows a statistically significant decrease of the 25th percentile; 7-month rainfall (Oct-Apr) additionally shows a statistically significant but non-robust decrease of the mean. The modest amount of water extraction (annually: ~14*103m3, ~0.004% of total lake volume) exerts a progressive and significant impact on lake level over the longer term, accounting for ~25% of the observed fall. Lake level lowering ends when lake-surface area shrinkage has led to a decrease in lake-surface evaporation that is equivalent to the amount of water extracted. The adjustment of lake level to stable extraction rates requires two to three decades. This work aims to steer adaptation and mitigation strategies by informing on lake response under different climate change and extraction scenarios. Lake protection is a cost effective solution for supporting global biodiversity and for providing sustainable water resources.

Water-level and recoverable water in storage changes, High Plains aquifer, predevelopment to 2015 and 2013–15

USGS Publications Warehouse

McGuire, Virginia L.

2017-06-01

The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial irrigation with groundwater in the aquifer area (about 1950). This report presents water-level changes and change in recoverable water in storage in the High Plains aquifer from predevelopment (about 1950) to 2015 and from 2013 to 2015.The methods to calculate area-weighted, average water-level changes; change in recoverable water in storage; and total recoverable water in storage used geospatial data layers organized as rasters with a cell size of 500 meters by 500 meters, which is an area of about 62 acres. Raster datasets of water-level changes are provided for other uses.Water-level changes from predevelopment to 2015, by well, ranged from a rise of 84 feet to a decline of 234 feet. Water-level changes from 2013 to 2015, by well, ranged from a rise of 24 feet to a decline of 33 feet. The area-weighted, average water-level changes in the aquifer were an overall decline of 15.8 feet from predevelopment to 2015 and a decline of 0.6 feet from 2013 to 2015. Total recoverable water in storage in the aquifer in 2015 was about 2.91 billion acre-feet, which was a decline of about 273.2 million acre-feet since predevelopment and a decline of 10.7 million acre-feet from 2013 to 2015.

Towards risk-based drought management in the Netherlands: making water supply levels transparent to water users

NASA Astrophysics Data System (ADS)

Maat Judith, Ter; Marjolein, Mens; Vuren Saskia, Van; der Vat Marnix, Van

2016-04-01

To prepare the Dutch Delta for future droughts and water scarcity, a nation-wide 4-year project, called Delta Programme, assessed the impact of climate change and socio-economic development, and explored strategies to deal with these impacts. The Programme initiated a joint approach to water supply management with stakeholders and developed a national adaptation plan that is able to adapt to future uncertain conditions. The adaptation plan consists of a set of preferred policy pathways - sequences of possible actions and measures through time - to achieve targets while responding in a flexible manner to uncertain developments over time, allowing room to respond to new opportunities and insights. With regard to fresh water allocation, the Delta Programme stated that supplying water of sufficient quality is a shared responsibility that requires cohesive efforts among users in the main and regional water system. The national and local authorities and water users involved agreed that the water availability and, where relevant, the water quality should be as transparent and predictable as possible under normal, dry and extremely dry conditions. They therefore introduced the concept of "water supply service levels", which should describe water availability and quality that can be delivered with a certain return period, for all regions and all relevant water users in the Netherlands. The service levels form an addition to the present policy and should be decided on by 2021. At present water allocation during periods of (expected) water shortage occurs according to a prearranged ranking system (a water hierarchy scheme based on a list of priorities), if water availability drops below a critical low level. The aim is to have supply levels available that are based on the probability of occurrence and economic impact of water shortage, and that are transparent for all water users in the regional water systems and the main water system. As part of the European project

Use of finite-difference arrays of observation wells to estimate evapotranspiration from ground water in the Arkansas River Valley, Colorado

USGS Publications Warehouse

Weeks, Edwin P.; Sorey, M.L.

1973-01-01

A method to determine evapotranspiration from ground water was tested at four sites in the flood plain of the Arkansas River in Colorado. Approximate ground-water budgets were obtained by analyzing water-level data from observation wells installed in five-point arrays. The analyses were based on finite difference approximations of the differential equation describing ground-water flow. Data from the sites were divided into two groups by season. It was assumed that water levels during the dormant season were unaffected by evapotranspiration of ground water or by recharge, collectively termed 'accretion.' Regression analyses of these data were made to provide an equation for separating the effects of changes in aquifer storage and of aquifer heterogeneity from those due to accretion during the growing season. The data collected during the growing season were thus analyzed to determine accretion.

Climate change and prairie pothole wetlands: mitigating water-level and hydroperiod effects through upland management

USGS Publications Warehouse

Renton, David A.; Mushet, David M.; DeKeyser, Edward S.

2015-01-01

Prairie pothole wetlands offer crucial habitat for North America’s waterfowl populations. The wetlands also support an abundance of other species and provide ecological services valued by society. The hydrology of prairie pothole wetlands is dependent on atmospheric interactions. Therefore, changes to the region’s climate can have profound effects on wetland hydrology. The relevant literature related to climate change and upland management effects on prairie pothole wetland water levels and hydroperiods was reviewed. Climate change is widely expected to affect water levels and hydroperiods of prairie pothole wetlands, as well as the biota and ecological services that the wetlands support. In general, hydrologic model projections that incorporate future climate change scenarios forecast lower water levels in prairie pothole wetlands and longer periods spent in a dry condition, despite potential increases in precipitation. However, the extreme natural variability in climate and hydrology of prairie pothole wetlands necessitates caution when interpreting model results. Recent changes in weather patterns throughout much of the Prairie Pothole Region have been in increased precipitation that results in increased water inputs to wetlands above losses associated with warmer temperatures. However, observed precipitation increases are within the range of natural climate variability and therefore, may not persist. Identifying management techniques with the potential to affect water inputs to prairie pothole wetlands would provide increased options for managers when dealing with the uncertainties associated with a changing climate. Several grassland management techniques (for example, grazing and burning) have the potential to affect water levels and hydroperiods of prairie pothole by affecting infiltration, evapotranspiration, and snow deposition.

Politics of innovation in multi-level water governance systems

NASA Astrophysics Data System (ADS)

Daniell, Katherine A.; Coombes, Peter J.; White, Ian

2014-11-01

Innovations are being proposed in many countries in order to support change towards more sustainable and water secure futures. However, the extent to which they can be implemented is subject to complex politics and powerful coalitions across multi-level governance systems and scales of interest. Exactly how innovation uptake can be best facilitated or blocked in these complex systems is thus a matter of important practical and research interest in water cycle management. From intervention research studies in Australia, China and Bulgaria, this paper seeks to describe and analyse the behind-the-scenes struggles and coalition-building that occurs between water utility providers, private companies, experts, communities and all levels of government in an effort to support or block specific innovations. The research findings suggest that in order to ensure successful passage of the proposed innovations, champions for it are required from at least two administrative levels, including one with innovation implementation capacity, as part of a larger supportive coalition. Higher governance levels can play an important enabling role in facilitating the passage of certain types of innovations that may be in competition with currently entrenched systems of water management. Due to a range of natural biases, experts on certain innovations and disciplines may form part of supporting or blocking coalitions but their evaluations of worth for water system sustainability and security are likely to be subject to competing claims based on different values and expertise, so may not necessarily be of use in resolving questions of "best courses of action". This remains a political values-based decision to be negotiated through the receiving multi-level water governance system.

Cassini/CIRS Observations of Water Vapor in Saturn's Stratosphere

NASA Technical Reports Server (NTRS)

Bjoraker, G. L.; Achterberg, R. K.; Simon-Miller, A. A.; Carlson, R. C.; Jennings, D. E.

2008-01-01

The Composite Infrared Spectrometer (CIRS) on the Cassini spacecraft has obtained numerous spectra of Saturn at varying spectral and spatial resolutions since Saturn Orbit Insertion in 2004. Emission lines due to water vapor in Saturn's stratosphere were first detected using whole-disk observations from the Infrared Space Observatory (Feuchtgruber et al 1997) and subsequently confirmed by the Submillimeter Wave Astronomy Satellite (Rergin et al 2000). CIRS has detected water and the data permit the retrieval of the latitudinal variation of water on Saturn. Emission lines of H2O on Saturn are very weak in the CIRS data. Thus. large spectral averages as well as improvements in calibration are necessary to detect water vapor. Zonally averaged nadir spectra were produced every 10 degrees of latitude. Stratospheric temperatures in the 0.5 - 5.0 mbar range were obtained by inverting spectra of CH4 in the v4 band centered at 1304 cm(exp -1). The origin of water vapor is believed to be from the ablation of micrometeorites containing water ice, followed by photochemistry. This external source of oxygen originates either from the Saturn system (from the rings or perhaps from Enceladus) or from the interplanetary medium. Connerney (1986) proposed a mechanism to transport water from the inner edge of the B-ring along magnetic field lines to specific latitudes (50N and 44S) on Saturn. Prange et al (2006) interpreted a minimum in the abundance of acetylene from ultraviolet spectra near 41S on Saturn as possibly due to an enhanced influx of water. Existing CIRS far-IR spectra are at relatively low spatial resolution, but observations at closer range planned for the extended mission will be able to test the "ring rain" mechanism by searching for localized water vapor enhancement at midlatitudes.

Variability of Radiosonde-Observed Precipitable Water in the Baltic Region

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

Jakobson, Erko; Ohvril, H.; Okulov, O.

The total mass of columnar water vapor (precipitable water, W) is an important parameter of atmospheric thermodynamic and radiative models. In this work radiosonde observations from 17 aerological stations in the Baltic region during 14 years, 1989?2002, were used to examine the variability of precipitable water. A table of monthly and annual means of W for the stations is given. Seasonal and annual means of W are expressed as linear functions of geographical latitude. Linear formulas are also derived for parameterization of precipitable water as function of surface water vapor pressure at each station.

Winter Thaws Can Raise Ground Water Levels in Driftless Area

Treesearch

Richard S. Sartz

1967-01-01

Springflow and ground water levels both rose with winter thaws, even when the ground was frozen. A high soil water content suggests that water moved to the water table through a continuous column of soil water rather than as a wetting front

High level tritiated water monitoring by Bremsstrahlung counting using a silicon drift detector

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

Niemes, S.; Sturm, M.; Michling, R.

2015-03-15

The β-ray induced X-ray spectrometry (BIXS) is a promising technique to monitor the tritium concentration in a fuel cycle of a fusion reactor. For in-situ measurements of high level tritiated water by Bremsstrahlung counting, the characteristics of a low-noise silicon drift detector (SDD) have been examined at the Tritium Laboratory Karlsruhe (TLK). In static measurements with constant sample volume and tritium concentration, the Bremsstrahlung spectra of tritiated water samples in a concentration range of 0.02 to 15 MBq/ml have been obtained. The volume has been kept constant at 5 cm{sup 3}. The observed spectra are well above the noise threshold.more » In addition to X-rays induced by β-rays, the spectra feature X-ray fluorescence peaks of the surrounding materials. No indications of memory effects have been observed. A linear relation between the X-ray intensity and the tritium concentration was obtained and the lower detection limit of the setup has been determined to 1 MBq ml{sup -1}, assessed by the Curie criterion. In addition, the spectra obtained experimentally could be reproduced with high agreement by Monte-Carlo simulations using the GEANT4-tool-kit. It was found that the present detection system is applicable to non-invasive measurements of high-level tritiated water and the SDD is a convenient tool to detect the low energy Bremsstrahlung X-rays. (authors)« less

Variation of levels and distribution of N-nitrosamines in different seasons in drinking waters of East China.

PubMed

Li, Ting; Yu, Dian; Xian, Qiming; Li, Aimin; Sun, Cheng

2015-08-01

We surveyed the occurrence of nine N-nitrosamine species in ten bottled drinking waters from supermarket and other water samples including raw waters, finished waters, and distribution system waters from nine municipal drinking water treatment plants in eight cities of Jiangsu Province, East China. N-nitrosodimethylamine (NDMA) was detected in one of ten bottled drinking water samples at concentration of 4.8 ng/L and N-nitrosomorpholine (NMor) was detected in four of the ten bottles with an average concentration and a standard deviation of 16 ± 15 ng/L. The levels of nitrosamines in the distribution system water samples collected during summer season ranged from below detection limit (BDL) to 5.4 ng/L for NDMA, BDL to 9.5 ng/L for N-nitrosomethylethylamine (NMEA), BDL to 2.7 ng/L for N-nitrosodiethylamine (NDEA) and BDL to 8.5 ng/L for N-nitrosopyrrolidine (NPyr). Samples of distribution system waters collected in winter season had levels of nitrosamines ranged from BDL to 45 ng/L for NDMA, BDL to 5.2 ng/L for NPyr, and BDL to 309 ng/L for N-nitrosopiperidine (NPip). A positive correlation of the concentration of NDMA as well as the total nine N-nitrosamines between finished waters and distribution system waters was observed. Both dissolved organic carbon and nitrite were found to correlate linearly with N-nitrosamine levels in raw waters.

Tides and lake-level variations in the great Patagonian lakes: Observations, modelling and geophysical implications.

NASA Astrophysics Data System (ADS)

Marderwald, Eric; Richter, Andreas; Horwath, Martin; Hormaechea, Jose Luis; Groh, Andreas

2016-04-01

In Patagonia, the glacial-isostatic adjustment (GIA) to past ice-mass changes (Ivins & James 2004; Klemann et al. 2007) is of particular interest in the context of the determination of the complex regional rheology related to plate subduction in a triple-junction constellation. To further complicate the situation, GIA is overlaid with load deformation not only due to present ice mass changes but also due to water-level changes in the lakes surrounding the icefields and the ocean surrounding Patagonia. These elastic deformations affect the determination of glacial-isostatic uplift rates from GPS observations (Dietrich et al. 2010; Lange et al. 2014). Observations of lake tides and their comparison with the theoretical tidal signal have been used previously to validate predictions of ocean tidal loading and have revealed regional deviations from conventional global elastic earth models (Richter et al. 2009). In this work we investigate the tides and lake-level variations in Lago Argentino, Lago Viedma, Lago San Martín/O'Higgins and Lago Buenos Aires/General Carrera. This allows us to test, among other things, the validity of tidal loading models. We present pressure tide-gauge records from two sites in Lago Argentino extending over 2.5 years (Richter et al. 2015). These observations are complemented by lake-level records provided by the Argentine National Hydrometeorological Network. Based on these lake-level time series the principal processes affecting the lake level are identified and quantified. Lake-level changes reflecting variations in lake volume are dominated by a seasonal cycle exceeding 1 m in amplitude. Lake-volume changes occur in addition with a daily period in response to melt water influx from surrounding glaciers. In Lago Argentino sporadic lake-volume jumps are caused by bursting of the ice dam of Perito Moreno glacier. Water movements in these lakes are dominated by surface seiches reaching 20 cm in amplitude. A harmonic tidal analysis of the lake-level

Prevalence of arsenic exposure in population of Ballia district from drinking water and its correlation with blood arsenic level.

PubMed

Katiyar, Shashwat; Singh, Dharam

2014-05-01

An investigation was carried out to ascertain the effect of arsenic in the blocks of Ballia district in Uttar Pradesh in the upper and middle Ganga plain, India. Analysis of 100 drinking water samples revealed that arsenic concentration was below 10 μg l⁻¹ in 60% samples, 10-50 μg l⁻¹ in 6%, 100 μg l⁻¹ in 24% and 200 μg l⁻¹ in 10% samples, respectively. The arsenic concentration in drinking water ranged from 12.8 to 132.2 μg l⁻¹. The depth of source of drinking water (10-60 m) was also found with a mean of 36.12 ± 13.61 μg l⁻¹ arsenic concentration. Observations revealed that at depth ranging from 10 to 20 m, the mean level of arsenic concentration was 17.398 ± 21.796 μg l⁻¹, while at 21 to 40 m depth As level was 39.685 ± 40.832 μg l⁻¹ and at 41 to 60 m As level was 46.89 ± 52.80 μg l⁻¹, respectively. These observations revealed a significant positive correlation (r = 0.716, t = 4.215, P < 0.05) between depth and arsenic concentration in drinking water. The age of water sources were ranged from zero to 30 years. The study indicates that the older sources of drinking water showed higher chance of contamination. Results showed that group 21-30 years having maximum arsenic concentration with mean value of 52.57 ± 53.79 μg l⁻¹. Correlation analysis also showed a significant positive correlation (r = 0.801, t = 5.66, P < 0.05) between age of drinking water sources and their respective arsenic concentration (μg l⁻¹). Arsenic concentration in blood with mean value 0.226 ± 0.177 μg dl⁻¹ significantly increased as compared to control. The blood arsenic content correlated significantly (r = 0.6823, t = 3.93, P < 0.05) with drinking water arsenic level and exposure time (r = 0.545, t = 3.101 & *P < 0.05) for populations residing in Ballia districts. Observations and correlation analysis revealed that individuals having depth of drinking water sources 20-30 m were less affected with arsenic exposure.

Water levels and artesian pressures in the Chad Basin of northeastern Nigeria, 1963-68

USGS Publications Warehouse

Carmalt, S.W.; Tibbitts, G.C.

1969-01-01

This report presents records of water levels and artesian pressures collected during 1963-68 on an observational network of 116 dug wells and boreholes (drilled wells) in the Chad Basin of northeastern Nigeria. The Chad Basin is underlain by the Chad Formation, a series of fluvio-lacustrine sediments which attain a thickness of 1,500 feet or more in Nigeria. Three water-bearing zones, designated Upper, Middle and Lower, have been identified in the Chad Formation of Nigeria. The Upper Zone aquifer, which contains water under both unconfined and confined conditions, provides the principal source of water to dug wells for domestic and village water supply. The Middle Zone aquifer is tapped by numerous deep boreholes (drilled wells) which provide water by artesian flow in more than 13,000 square miles of Nigeria north and east of Maiduguri. The Lower Zone, which is also confined has only been identified thus far (1969) in the vicinity of Maiduguri.

Tritiated Water on Molecular Sieve: Water Dynamics and Pressure Observations

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

Walters, R.T.

1999-04-23

The production of fusion energy in a Tokamak using deuterium and tritium requires the safe handling and processing of exhaust gases that contain various amounts of tritium. Initial operation of the Tokamak Fusion Test Reactor (TFTR), Princeton Plasma Physics Laboratory, oxidized exhaust gases for tritium recovery or long-term storage. One of the most efficient and safest ways to contain tritiated water is to sorb it onto a pelletized 4A molecular sieve. A Disposable Molecular Sieve Bed (DMSB) was designed as a pressure vessel because of the possibility of pressure generation from the radiolysis of tritiated water on molecular sieve. Hydrogenmore » production contributes to the complexity of the containers used to transport and store tritiated water, and increases the fabrication costs. Two months after removing a DMSB from the process at TFTR, a pressure in excess of that predicted from self-radiolysis was observed. Interestingly, pressure measurements at longer times (up to 2.5 years) showed less pressure than expected. Pressure was not being generated in the DMSBs at the predicted rate. This was unexpected and prompted an investigation into the mechanism responsible for the anomalous pressure measurements.« less

Investigating Storm-Induced Total Water Levels on Complex Barred Beaches

NASA Astrophysics Data System (ADS)

Cohn, N.; Ruggiero, P.; Walstra, D.

2013-12-01

Water levels in coastal environments are not static, but rather vary from a range of factors including mean sea level, tides, storm surge, and wave runup. Cumulatively these superimposed factors determine the total water level (TWL), the extent of which has major implications for coastal erosion and inundation during periods of high energy. Storm-induced, super-elevated water levels pose a threat to low lying coastal regions, as clearly demonstrated by recent events such as Hurricanes Sandy and Katrina. For this reason, the ability to accurately predict the TWL is crucial for both emergency managers and coastal planners. While some components of TWL are well understood (e.g., tides) there is still significant uncertainty in predicting runup, a process that can be a major contributor to instantaneous TWLs. Traditionally, empirical relationships derived from observational field data have been used to estimate runup, including wave setup and both incident and infragravity swash (Stockdon et al., 2006). While these formulations have shown skill in predicting the runup extent on natural beaches, these equations consider only the most basic contributing factors - namely the mean foreshore beach slope, the offshore wave height, and offshore wave period. Not included in these empirical estimates is the role of nearshore morphology on TWLs. However, it has long been recognized that nearshore sandbars act as natural barriers to coastal erosion during storm events by dissipating wave energy far from the beach face. Nonetheless, the influence of nearshore morphology on inner surf zone processes, including wave runup, is poorly understood. Recent pioneering studies (eg., Soldini et al., 2013 and Stephens et al., 2011) have explored the role of simple nearshore features (single Gaussian bars) on swash processes. Many locations in the world, however, are characterized by more complex morphologies such as multiple barred systems. Further, in many such places, including Columbia

Response of groundwater level and surface-water/groundwater interaction to climate variability: Clarence-Moreton Basin, Australia

NASA Astrophysics Data System (ADS)

Cui, Tao; Raiber, Matthias; Pagendam, Dan; Gilfedder, Mat; Rassam, David

2018-03-01

Understanding the response of groundwater levels in alluvial and sedimentary basin aquifers to climatic variability and human water-resource developments is a key step in many hydrogeological investigations. This study presents an analysis of groundwater response to climate variability from 2000 to 2012 in the Queensland part of the sedimentary Clarence-Moreton Basin, Australia. It contributes to the baseline hydrogeological understanding by identifying the primary groundwater flow pattern, water-level response to climate extremes, and the resulting dynamics of surface-water/groundwater interaction. Groundwater-level measurements from thousands of bores over several decades were analysed using Kriging and nonparametric trend analysis, together with a newly developed three-dimensional geological model. Groundwater-level contours suggest that groundwater flow in the shallow aquifers shows local variations in the close vicinity of streams, notwithstanding general conformance with topographic relief. The trend analysis reveals that climate variability can be quickly reflected in the shallow aquifers of the Clarence-Moreton Basin although the alluvial aquifers have a quicker rainfall response than the sedimentary bedrock formations. The Lockyer Valley alluvium represents the most sensitively responding alluvium in the area, with the highest declining (-0.7 m/year) and ascending (2.1 m/year) Sen's slope rates during and after the drought period, respectively. Different surface-water/groundwater interaction characteristics were observed in different catchments by studying groundwater-level fluctuations along hydrogeologic cross-sections. The findings of this study lay a foundation for future water-resource management in the study area.

Ground-water levels, water quality, and potential effects of toxic-substance spills or cessation of quarry dewatering near a municipal ground-water supply, southeastern Franklin County, Ohio

USGS Publications Warehouse

Sedam, A.C.; Eberts, S.M.; Bair, E.S.

1989-01-01

A newly completed municipal ground-water supply that produces from a sand and gravel aquifer in southern Franklin County, Ohio, may be susceptible to potential sources of pollution. Among these are spills of toxic substances that could enter recharge areas of the aquifer or be carried by surface drainage and subsequently enter the aquifer by induced infiltration. Ground water of degraded quality also is present in the vicinity of several landfills located upstream from the municipal supply. Local dewatering by quarrying operations has created a ground-water divide which, at present, prevents direct movement of the degraded ground water to the municipal supply. In addition, the dewatering has held water levels at the largest landfills below the base of the landfill. Should the dewatering cease, concern would be raised regarding the rise of water levels at this landfills and transport of contaminants through the aquifer to the Scioto River and subsequently by the river to the well field. From June 1984 through July 1986, the U.S. Geological Survey, in cooperation with the City of Columbus, Ohio, investigated the relations among the ground-water supply and potential sources of contamination by means of an observation-well network and a program of measuring water levels and sampling for water quality. Sample collections included those made to determine the baseline levels of organic chemicals and metals, as well as periodic sampling and analysis for common constituents to evaluate any changes taking place in the system. Finally, a steady-state, three-dimensional numerical model was used to determine ground-water flow directions and average ground-water velocities to asses potential effects of toxic-substance spills. The model also was used to simulate changes in the ground-water flow system that could result if part or all of the quarry dewatering ceased. Few of the organic-chemical and metal constituents analyzed for were present at detectable levels. With respect to

Continental-scale water fluxes from continuous GPS observations of Earth surface loading

NASA Astrophysics Data System (ADS)

Borsa, A. A.; Agnew, D. C.; Cayan, D. R.

2015-12-01

After more than a decade of observing annual oscillations of Earth's surface from seasonal snow and water loading, continuous GPS is now being used to model time-varying terrestrial water fluxes on the local and regional scale. Although the largest signal is typically due to the seasonal hydrological cycle, GPS can also measure subtle surface deformation caused by sustained wet and dry periods, and to estimate the spatial distribution of the underlying terrestrial water storage changes. The next frontier is expanding this analysis to the continental scale and paving the way for incorporating GPS models into the National Climate Assessment and into the observational infrastructure for national water resource management. This will require reconciling GPS observations with predictions from hydrological models and with remote sensing observations from a suite of satellite instruments (e.g. GRACE, SMAP, SWOT). The elastic Earth response which transforms surface loads into vertical and horizontal displacements is also responsible for the contamination of loading observations by tectonic and anthropogenic transients, and we discuss these and other challenges to this new application of GPS.

Water levels of the Ozark aquifer in northern Arkansas, 2013

USGS Publications Warehouse

Schrader, Tony P.

2015-07-13

Nine hydrographs were selected as representative of the water-level conditions in their respective counties. Wells in Fulton, Izard, and Newton Counties (station names 20N08W27ABD1, 18N09W15BCB1, and 16N21W34ABC1, respectively) have water levels that are within the usual range of values for their respective counties. Wells in Boone, Marion, and Washington Counties (station names 18N19W19BCC1, 19N15W20ACC1, and 16N32W09ABD1, respectively) have water levels that have recently declined or are declining for the period of record. Wells in Benton, Carroll, and Sharp Counties (station names 19N29W07DAA1, 21N26W17BCC1, and 15N05W06DDD1, respectively) have water levels that have been rising recently.

Water-Column Stratification Observed along an AUV-Tracked Isotherm

NASA Astrophysics Data System (ADS)

Zhang, Y.; Messié, M.; Ryan, J. P.; Kieft, B.; Stanway, M. J.; Hobson, B.; O'Reilly, T. C.; Raanan, B. Y.; Smith, J. M.; Chavez, F.

2016-02-01

Studies of marine physical, chemical and microbiological processes benefit from observing in a Lagrangian frame of reference, i.e. drifting with ambient water. Because these processes can be organized relative to specific density or temperature ranges, maintaining observing platforms within targeted environmental ranges is an important observing strategy. We have developed a novel method to enable a Tethys-class long-range autonomous underwater vehicle (AUV) (which has a propeller and a buoyancy engine) to track a target isotherm in buoyancy-controlled drift mode. In this mode, the vehicle shuts off its propeller and autonomously detects the isotherm and stays with it by actively controlling the vehicle's buoyancy. In the June 2015 CANON (Controlled, Agile, and Novel Observing Network) Experiment in Monterey Bay, California, AUV Makai tracked a target isotherm for 13 hours to study the coastal upwelling system. The tracked isotherm started from 33 m depth, shoaled to 10 m, and then deepened to 29 m. The thickness of the tracked isotherm layer (within 0.3°C error from the target temperature) increased over this duration, reflecting weakened stratification around the isotherm. During Makai's isotherm tracking, another long-range AUV, Daphne, acoustically tracked Makai on a circular yo-yo trajectory, measuring water-column profiles in Makai's vicinity. A wave glider also acoustically tracked Makai, providing sea surface measurements on the track. The presented method is a new approach for studying water-column stratification, but requires careful analysis of the temporal and spatial variations mingled in the vehicles' measurements. We will present a synthesis of the water column's stratification in relation to the upwelling conditions, based on the in situ measurements by the mobile platforms, as well as remote sensing and mooring data.

A Poor Relationship Between Sea Level and Deep-Water Sand Delivery

NASA Astrophysics Data System (ADS)

Harris, Ashley D.; Baumgardner, Sarah E.; Sun, Tao; Granjeon, Didier

2018-08-01

The most commonly cited control on delivery of sand to deep water is the rate of relative sea-level fall. The rapid rate of accommodation loss on the shelf causes sedimentation to shift basinward. Field and experimental numerical modeling studies have shown that deep-water sand delivery can occur during any stage of relative sea level position and across a large range of values of rate of relative sea-level change. However, these studies did not investigate the impact of sediment transport efficiency on the relationship between rate of relative sea-level change and deep-water sand delivery rate. We explore this relationship using a deterministic nonlinear diffusion-based numerical stratigraphic forward model. We vary across three orders of magnitude the diffusion coefficient value for marine settings, which controls sediment transport efficiency. We find that the rate of relative sea-level change can explain no more than 1% of the variability in deep-water sand delivery rates, regardless of sediment transport efficiency. Model results show a better correlation with relative sea level, with up to 55% of the variability in deep water sand delivery rates explained. The results presented here are consistent with studies of natural settings which suggest stochastic processes such as avulsion and slope failure, and interactions among such processes, may explain the remaining variance. Relative sea level is a better predictor of deep-water sand delivery than rate of relative sea-level change because it is the sea-level fall itself which promotes sand delivery, not the rate of the fall. We conclude that the poor relationship between sea level and sand delivery is not an artifact of the modeling parameters but is instead due to the inadequacy of relative sea level and the rate of relative sea-level change to fully describe the dimensional space in which depositional systems reside. Subsequently, sea level itself is unable to account for the interaction of multiple processes

Water quality observations of ice-covered, stagnant, eutrophic water bodies and analysis of influence of ice-covered period on water quality

NASA Astrophysics Data System (ADS)

sugihara, K.; Nakatsugawa, M.

2013-12-01

The water quality characteristics of ice-covered, stagnant, eutrophic water bodies have not been clarified because of insufficient observations. It has been pointed out that climate change has been shortening the duration of ice-cover; however, the influence of climate change on water quality has not been clarified. This study clarifies the water quality characteristics of stagnant, eutrophic water bodies that freeze in winter, based on our surveys and simulations, and examines how climate change may influence those characteristics. We made fixed-point observation using self-registering equipment and vertical water sampling. Self-registering equipment measured water temperature and dissolved oxygen(DO).vertical water sampling analyzed biological oxygen demand(BOD), total nitrogen(T-N), nitrate nitrogen(NO3-N), nitrite nitrogen(NO2-N), ammonium nitrogen(NH4-N), total phosphorus(TP), orthophosphoric phosphorus(PO4-P) and chlorophyll-a(Chl-a). The survey found that climate-change-related increases in water temperature were suppressed by ice covering the water area, which also blocked oxygen supply. It was also clarified that the bottom sediment consumed oxygen and turned the water layers anaerobic beginning from the bottom layer, and that nutrient salts eluted from the bottom sediment. The eluted nutrient salts were stored in the water body until the ice melted. The ice-covered period of water bodies has been shortening, a finding based on the analysis of weather and water quality data from 1998 to 2008. Climate change was surveyed as having caused decreases in nutrient salts concentration because of the shortened ice-covered period. However, BOD in spring showed a tendency to increase because of the proliferation of phytoplankton that was promoted by the climate-change-related increase in water temperature. To forecast the water quality by using these findings, particularly the influence of climate change, we constructed a water quality simulation model that

Dependency of high coastal water level and river discharge at the global scale

NASA Astrophysics Data System (ADS)

Ward, P.; Couasnon, A.; Haigh, I. D.; Muis, S.; Veldkamp, T.; Winsemius, H.; Wahl, T.

2017-12-01

It is widely recognized that floods cause huge socioeconomic impacts. From 1980-2013, global flood losses exceeded $1 trillion, with 220,000 fatalities. These impacts are particularly hard felt in low-lying densely populated deltas and estuaries, whose location at the coast-land interface makes them naturally prone to flooding. When river and coastal floods coincide, their impacts in these deltas and estuaries are often worse than when they occur in isolation. Such floods are examples of so-called `compound events'. In this contribution, we present the first global scale analysis of the statistical dependency of high coastal water levels (and the storm surge component alone) and river discharge. We show that there is statistical dependency between these components at more than half of the stations examined. We also show time-lags in the highest correlation between peak discharges and coastal water levels. Finally, we assess the probability of the simultaneous occurrence of design discharge and design coastal water levels, assuming both independence and statistical dependence. For those stations where we identified statistical dependency, the probability is between 1 and 5 times greater, when the dependence structure is accounted for. This information is essential for understanding the likelihood of compound flood events occurring at locations around the world as well as for accurate flood risk assessments and effective flood risk management. The research was carried out by analysing the statistical dependency between observed coastal water levels (and the storm surge component) from GESLA-2 and river discharge using gauged data from GRDC stations all around the world. The dependence structure was examined using copula functions.

WaterML, an Information Standard for the Exchange of in-situ hydrological observations

NASA Astrophysics Data System (ADS)

Valentine, D.; Taylor, P.; Zaslavsky, I.

2012-04-01