Floods in the English River basin, Iowa

USGS Publications Warehouse

Heinitz, A.J.; Riddle, D.E.

1981-01-01

Information describing floods is essential for proper planning, design, and operation of bridges and other structures on or over streams and their flood plains. This report provides information on flood stages and discharges, flood magnitude and frequency, bench mark data, and flood profiles for the English River and some of its tributaries. It covers the English River, the North English River to near Guernsey, the south Eaglish River to Barnes City and the lower reaches of the Biddle English and Deep Rivers

Modulation of cosmic rays on geomagnetically most quiet days

NASA Astrophysics Data System (ADS)

Agarwal Mishra, Rekha; Agarwal Mishra, Rekha; Mishra, Rajesh Kumar

The aim of this work is to study the first three harmonics of cosmic ray intensity on geomagnetically quiet days over the period 1980-1990 for Deep River and Tokyo neutron monitoring stations. The amplitude of first harmonic remains high for Deep River having low cutoff rigidity as compared to Tokyo neutron monitor having high cutoff rigidity on quiet days.. The diurnal time of maximum significantly shifts to an earlier time as compared to the corotational/1800 Hr direction at both the stations having different cutoff rigidities. The time of maximum for first harmonic significantly shifts towards later hours and for second harmonic it shifts towards earlier hours at low cutoff rigidity station i.e. Deep River as compared to the high cut off rigidity station i.e. Tokyo on quiet days. The amplitude of semi/tri-diurnal anisotropy have a good positive correlation with solar wind velocity, while the others (i.e. amplitude and phase) have no significant correlation on quiet days for Deep River and Tokyo having different cutoff rigidity during 1980-1990. The solar wind velocity significantly remains in the range 350 to 425 km/s i.e. being nearly average on quiet days. The amplitude and direction of the anisotropy on quiet days are weakly dependent on high-speed solar wind streams for two neutron monitoring station of low and high cutoff rigidity threshold. The semi-diurnal amplitude has a significant anti-correlation, whereas the amplitude of third harmonic and direction of first harmonic has a good anti-correlation with IMF Bz and the product V x Bz on quiet days at Deep River station. However, the direction of first harmonic has a significant anti-correlation and the direction of second harmonic has a good anti-correlation with IMF Bz and the product V x Bz on quiet days at Tokyo station.

Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 5.

DTIC Science & Technology

1973-11-01

Prior to the 1930’s the river bottoms were primarily wooded islands separated by deep sloughs. Hundreds of lakes and ponds were scattered through the... wooded bottoms. Bay meadows and small farming areas occupied some areas on larger islands. Marshes were limited to the shores of lakes and guts...the old condition of deep sloughs and wooded islands is found. In the middle of each pool, water backs up over the islands and old hay meadows

Source to sink: Evolution of lignin composition in the Madre de Dios River system with connection to the Amazon basin and offshore

NASA Astrophysics Data System (ADS)

Feng, Xiaojuan; Feakins, Sarah J.; Liu, Zongguang; Ponton, Camilo; Wang, Renée. Z.; Karkabi, Elias; Galy, Valier; Berelson, William M.; Nottingham, Andrew T.; Meir, Patrick; West, A. Joshua

2016-05-01

While lignin geochemistry has been extensively investigated in the Amazon River, little is known about lignin distribution and dynamics within deep, stratified river channels or its transformations within soils prior to delivery to rivers. We characterized lignin phenols in soils, river particulate organic matter (POM), and dissolved organic matter (DOM) across a 4 km elevation gradient in the Madre de Dios River system, Peru, as well as in marine sediments to investigate the source-to-sink evolution of lignin. In soils, we found more oxidized lignin in organic horizons relative to mineral horizons. The oxidized lignin signature was maintained during transfer into rivers, and lignin was a relatively constant fraction of bulk organic carbon in soils and riverine POM. Lignin in DOM became increasingly oxidized downstream, indicating active transformation of dissolved lignin during transport, especially in the dry season. In contrast, POM accumulated undegraded lignin downstream during the wet season, suggesting that terrestrial input exceeded in-river degradation. We discovered high concentrations of relatively undegraded lignin in POM at depth in the lower Madre de Dios River in both seasons, revealing a woody undercurrent for its transfer within these deep rivers. Our study of lignin evolution in the soil-river-ocean continuum highlights important seasonal and depth variations of river carbon components and their connection to soil carbon pools, providing new insights into fluvial carbon dynamics associated with the transfer of lignin biomarkers from source to sink.

10. VIEW OF WEST ELEVATION OF POWERHOUSE, CANAL, AND RETAINING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. VIEW OF WEST ELEVATION OF POWERHOUSE, CANAL, AND RETAINING WALLS FROM NORTH BANK OF CANAL - Lockville Hydroelectric Plant, Deep River, 3.5 miles upstream from Haw River, Moncure, Chatham County, NC

Quantification and Characterization of Chloride Sources in the Rio Grande, Southwestern United States

NASA Astrophysics Data System (ADS)

Lacey, H. F.; Phillips, F. M.; Tidwell, V.; Hogan, J.; Bastien, E.; Oelsner, G.

2005-12-01

Salinization of rivers is a problem in the southwestern United States as well as in other semiarid and arid regions of the world. Arid and semiarid rivers including the Rio Grande often exhibit increasing salinity with distance downstream, which is commonly attributed to irrigated agriculture. Increased river salinity causes economic losses by reducing crop productivity, rendering the water unsuitable for many municipal and industrial uses, and corroding or plugging pipes. Although most salinization of the Rio Grande takes place in the United States, many of the effects are felt in Mexico. Recent studies have found that salinization of the Rio Grande is geologically controlled by the addition of deep saline brines at several distinct locations. However, these additions of deep brine have not been well quantified. We have designed a model using a system dynamics software program to analyze Rio Grande chloride data. The model uses historical chloride and gaging station data and high-resolution synoptic chloride samples collected between 2000 and 2005 to characterize and quantify additions of deep brine to the river. The model has also been used to evaluate the effect of the construction of Elephant Butte Reservoir on the chloride balance of the river using chloride concentration data from 1905-1907. The model can also be used to evaluate future climatic and management scenarios in order to plan for the future water needs of the basin.

Sediment Transportation Induced by Deep-Seated Landslides in a Debris Flow Basin in Taiwan

NASA Astrophysics Data System (ADS)

Lin, Meei Ling; Chen, Te Wei; Chen, Yong Sheng; Sin Jhuang, Han

2016-04-01

Typhoon Morakot brought huge amount of rainfall to the southern Taiwan in 2009 and caused severe landslides and debris flow hazard. After Typhoon Morakot, it was found that the volume of sediment transported by the debris flow and its effects on the affected area were much more significant compared to previous case history, which may due to the huge amount of rainfall causing significant deep-seated landslides in the basin. In this study, the effects and tendency of the sediment transportation in a river basin following deep-seated landslides caused by typhoon Morakot were evaluated. We used LiDAR, DEM, and aerial photo to identify characteristics of deep-seated landslides in a debris flow river basin, KSDF079 in Liuoguey District, Kaohsiung City, Taiwan. Eight deep-seated landslides were identified in the basin. To estimate the potential landslide volume associated with the deep-seated landslides, the stability analysis was conducted to locate the critical sliding surface, and the potential landside volume was estimated based on the estimation equation proposed by the International Geotechnical Societies' UNESCO Working Party on World Landslide Inventory (WP/WLI, 1990). The total potential landslide volume of the eight deep-seated landslides in KSDF079 basin was about 28,906,856 m3. Topographic analysis was performed by using DEM before and LiDAR derived DEM after typhoon Morakot to calculate the landslide volume transported. The result of erosion volume and deposition volume lead to a run out volume of 5,832,433 m3. The results appeared to consist well with the field condition and aerial photo. Comparing the potential landslide volume and run out volume of eight deep-seated landslides, it was found that the remaining potential landslide volume was about 80%. Field investigation and topographic analysis of the KSDF079 debris flow revealed that a significant amount of sediment deposition remained in the river channel ranging from the middle to the downstream section of the channel, and the channel has been widen. Such large proportion of landslide volume remained in the basin on deep-seated landslide scars and debris flow river channel would likely to cause further debris transportation in the future events. The stability analysis used in this study provided a feasible method and satisfactory results for estimating sediment volume transportation associated with the deep-seated landslides in the study area. Combination of the stability analysis results and the topographic analysis provided estimation of sediment transportation caused by the deep-seated landslides, and trend variation of further sediment transport of the basin, which could provide vital information for hazard mitigation. Keyword: deep-seated landslide, sediment transport, DEM, LiDAR, stability analysis

Four Major South Korea's Rivers Using Deep Learning Models.

PubMed

Lee, Sangmok; Lee, Donghyun

2018-06-24

Harmful algal blooms are an annual phenomenon that cause environmental damage, economic losses, and disease outbreaks. A fundamental solution to this problem is still lacking, thus, the best option for counteracting the effects of algal blooms is to improve advance warnings (predictions). However, existing physical prediction models have difficulties setting a clear coefficient indicating the relationship between each factor when predicting algal blooms, and many variable data sources are required for the analysis. These limitations are accompanied by high time and economic costs. Meanwhile, artificial intelligence and deep learning methods have become increasingly common in scientific research; attempts to apply the long short-term memory (LSTM) model to environmental research problems are increasing because the LSTM model exhibits good performance for time-series data prediction. However, few studies have applied deep learning models or LSTM to algal bloom prediction, especially in South Korea, where algal blooms occur annually. Therefore, we employed the LSTM model for algal bloom prediction in four major rivers of South Korea. We conducted short-term (one week) predictions by employing regression analysis and deep learning techniques on a newly constructed water quality and quantity dataset drawn from 16 dammed pools on the rivers. Three deep learning models (multilayer perceptron, MLP; recurrent neural network, RNN; and long short-term memory, LSTM) were used to predict chlorophyll-a, a recognized proxy for algal activity. The results were compared to those from OLS (ordinary least square) regression analysis and actual data based on the root mean square error (RSME). The LSTM model showed the highest prediction rate for harmful algal blooms and all deep learning models out-performed the OLS regression analysis. Our results reveal the potential for predicting algal blooms using LSTM and deep learning.

Nitrate removal in deep sediments of a nitrogen-rich river network: A test of a conceptual model

USGS Publications Warehouse

Stelzer, Robert S.; Bartsch, Lynn

2012-01-01

Many estimates of nitrogen removal in streams and watersheds do not include or account for nitrate removal in deep sediments, particularly in gaining streams. We developed and tested a conceptual model for nitrate removal in deep sediments in a nitrogen-rich river network. The model predicts that oxic, nitrate-rich groundwater will become depleted in nitrate as groundwater upwelling through sediments encounters a zone that contains buried particulate organic carbon, which promotes redox conditions favorable for nitrate removal. We tested the model at eight sites in upwelling reaches of lotic ecosystems in the Waupaca River Watershed that varied by three orders of magnitude in groundwater nitrate concentration. We measured denitrification potential in sediment core sections to 30 cm and developed vertical nitrate profiles to a depth of about 1 m with peepers and piezometer nests. Denitrification potential was higher, on average, in shallower core sections. However, core sections deeper than 5 cm accounted for 70%, on average, of the depth-integrated denitrification potential. Denitrification potential increased linearly with groundwater nitrate concentration up to 2 mg NO3-N/L but the relationship broke down at higher concentrations (> 5 mg NO3-N/L), a pattern that suggests nitrate saturation. At most sites groundwater nitrate declined from high concentrations at depth to much lower concentrations prior to discharge into the surface water. The profiles suggested that nitrate removal occurred at sediment depths between 20 and 40 cm. Dissolved oxygen concentrations were much higher in deep sediments than in pore water at 5 cm sediment depth at most locations. The substantial denitrification potential in deep sediments coupled with the declines in nitrate and dissolved oxygen concentrations in upwelling groundwater suggest that our conceptual model for nitrate removal in deep sediments is applicable to this river network. Our results suggest that nitrate removal rates can be high in deep sediments of upwelling stream reaches, which may have implications for efforts to understand and quantify nitrogen transport and removal at larger scales.

Monitoring of Deep Foundation Pit Support and Construction Process in Soft Soil Area of Pearl River Delta

NASA Astrophysics Data System (ADS)

Weiyi, Xie; Pengcheng

2018-03-01

The deep foundation pit supporting technology in the soft soil area of the Pearl River Delta is more complicated, and many factors influence and restrict it. In this project as an example, according to the geological conditions and the surrounding circumstances, the main foundation using bored piles and pre-stressed anchor cable supporting structure + five axis cement mixing pile curtain supporting form; partial use of double row piles supporting structure + five axis cement mixing pile curtain support type. Through the monitoring results of construction show that the foundation pit, the indicators of environmental changes are in the design range, the supporting scheme of deep foundation pit technology is feasible and reliable.

Publications - GMC 64 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

sample from the AMOCO Production Company Cathedral River Unit #1 well Authors: Henning, Mitchel, and determination for a 10,650' deep cutting sample from the AMOCO Production Company Cathedral River Unit #1 well

Influence of the Amazon River on the Nd isotope composition of deep water in the western equatorial Atlantic during the Oligocene-Miocene transition

NASA Astrophysics Data System (ADS)

Stewart, Joseph A.; Gutjahr, Marcus; James, Rachael H.; Anand, Pallavi; Wilson, Paul A.

2016-11-01

Dissolved and particulate neodymium (Nd) are mainly supplied to the oceans via rivers, dust, and release from marine sediments along continental margins. This process, together with the short oceanic residence time of Nd, gives rise to pronounced spatial gradients in oceanic 143Nd/144Nd ratios (εNd). However, we do not yet have a good understanding of the extent to which the influence of riverine point-source Nd supply can be distinguished from changes in mixing between different water masses in the marine geological record. This gap in knowledge is important to fill because there is growing awareness that major global climate transitions may be associated not only with changes in large-scale ocean water mass mixing, but also with important changes in continental hydroclimate and weathering. Here we present εNd data for fossilised fish teeth, planktonic foraminifera, and the Fe-Mn oxyhydroxide and detrital fractions of sediments recovered from Ocean Drilling Project (ODP) Site 926 on Ceara Rise, situated approximately 800 km from the mouth of the River Amazon. Our records span the Mi-1 glaciation event during the Oligocene-Miocene transition (OMT; ∼23 Ma). We compare our εNd records with data for ambient deep Atlantic northern and southern component waters to assess the influence of particulate input from the Amazon River on Nd in ancient deep waters at this site. εNd values for all of our fish teeth, foraminifera, and Fe-Mn oxyhydroxide samples are extremely unradiogenic (εNd ≈ - 15); much lower than the εNd for deep waters of modern or Oligocene-Miocene age from the North Atlantic (εNd ≈ - 10) and South Atlantic (εNd ≈ - 8). This finding suggests that partial dissolution of detrital particulate material from the Amazon (εNd ≈ - 18) strongly influences the εNd values of deep waters at Ceara Rise across the OMT. We conclude that terrestrially derived inputs of Nd can affect εNd values of deep water many hundreds of kilometres from source. Our results both underscore the need for care in reconstructing changes in large-scale oceanic water-mass mixing using sites proximal to major rivers, and highlight the potential of these marine archives for tracing changes in continental hydroclimate and weathering.

The source and distribution of thermogenic dissolved organic matter in the ocean

NASA Astrophysics Data System (ADS)

Dittmar, T.; Suryaputra, I. G. N. A.; Paeng, J.

2009-04-01

Thermogenic organic matter (ThOM) is abundant in the environment. ThOM is produced at elevated temperature and pressure in deep sediments and earth's crust, and it is also a residue of fossil fuel and biomass burning ("black carbon"). Because of its refractory character, it accumulates in soils and sediments and, therefore, may sequester carbon from active cycles. It was hypothesized that a significant component of marine dissolved organic matter (DOM) might be thermogenic. Here we present a detailed data set on the distribution of thermogenic DOM in major water masses of the deep and surface ocean. In addition, several potential sources of thermogenic DOM to the ocean were investigated: active seeps of brine fluids in the deep Gulf of Mexico, rivers, estuaries and submarine groundwaters. Studies on deep-sea hydrothermal vents and aerosol deposition are ongoing. All DOM samples were isolated from seawater via solid phase extraction (SPE-DOM). ThOM was quantified in the extracts as benzene-polycarboxylic acids (BPCAs) after nitric acid oxidation via high-performance liquid chromatography and diode array detection (HPLC-DAD). BPCAs are produced exclusively from fused ring systems and are therefore unambiguous molecular tracers for ThOM. In addition to BPCA determination, the molecular composition and structure of ThOM was characterized in detail via ultrahigh resolution mass spectrometry (FT-ICR-MS). All marine and river DOM samples yielded significant amounts of BPCAs. The cold seep system in the deep Gulf of Mexico, but also black water rivers (like the Suwannee River) were particularly rich in ThOM. Up to 10% of total dissolved organic carbon was thermogenic in both systems. The most abundant BPCA was benzene-pentacarboxylic acid (B5CA). The molecular composition of BPCAs and the FT-ICR-MS data indicate a relatively small number (5-8) of fused aromatic rings per molecule. Overall, the molecular BPCA patterns were very similar independent of the source of ThOM. Petroleum-derived ThOM in the deep Gulf of Mexico had very similar structures than fused ring systems in asphaltenes, but also ThOM in the rivers and groundwaters was similar. First data on aerosols, on the other had, show a clear difference between particulate and dissolved samples. ThOM from aerosols and most soils was characterized by an abundance of benzene-hexacarboxylic acid (B6CA), different from thermogenic DOM. Dissolution processes may cause partial breakdown of larger fused ring systems and thus cause similar structural units in all DOM samples. In the deep ocean, the distribution of thermogenic DOM was relatively homogeneous throughout the water column. The concentration of carbon that resides in thermogenic polycyclic aromatic hydrocarbon varied between 610 and 800 nM (1.5-2% of total dissolved organic carbon). The total amount of thermogenic DOM in the deep ocean is approx. one Peta mole carbon globally. The relatively homogenous distribution of thermogenic DOM in the abyssal ocean indicates that thermogenic DOM behaves virtually inert in the abyssal environment. One of the most striking features is that the oldest water masses, which are not enriched in industrial products (such as the Freon CFC-12) showed highest concentrations of thermogenic DOM. The younger water masses such as Antarctic bottom and intermediate waters are not particularly enriched in thermogenic DOM. This distribution suggests a preindustrial origin of ThOM in the deep ocean. Rivers and deep-sea seep systems were both identified as potential sources of ThOM to the deep ocean. Radiocarbon dating on BPCAs will provide further evidence for the origin of BC in the deep ocean.

Water quality in the lower Puyallup River valley and adjacent uplands, Pierce County, Washington

USGS Publications Warehouse

Ebbert, J.C.; Bortleson, Gilbert C.; Fuste, L.A.; Prych, E.A.

1987-01-01

The quality of most ground and surface water within and adjacent to the lower Puyallup River valley is suitable for most typical uses; however, some degradation of shallow groundwater quality has occurred. High concentrations of iron and manganese were found in groundwater, sampled at depths of < 40 ft, from wells tapping alluvial aquifers and in a few wells tapping deeper aquifers. Volatile and acid- and base/neutral-extractable organic compounds were not detected in either shallow or deep groundwater samples. The quality of shallow groundwater was generally poorer than that of deep water. Deep ground water (wells set below 100 ft) appears suitable as a supplementary water supply for fish-hatchery needs. Some degradation of water quality, was observed downstream from river mile 1.7 where a municipal wastewater-treatment plant discharges into the river. In the Puyallup River, the highest concentrations of most trace elements were found in bed sediments collected downstream from river mile 1.7. Median concentrations of arsenic, lead, and zinc were higher in bed sediments from small streams compared with those from the Puyallup River, possibly because the small stream drainages, which are almost entirely within developed areas, receive more urban runoff as a percentage of total flow. Total-recoverable trace-element concentrations exceeded water-quality criteria for acute toxicity in the Puyallup River and in some of the small streams. In most cases, high concentrations of total-recoverable trace elements occurred when suspended-sediment concentrations were high. Temperatures in all streams except Wapato Creek and Fife Dutch were within limits (18 C) for Washington State class A water. Minimum dissolved oxygen concentrations were relatively low at 5.6 and 2.0 mg/L, respectively, for Wapato Creek and Fife Dutch. The poorest surface-water quality, which can be characterized as generally unsuitable for fish, was in Fife Dutch, a manmade channel and therefore uncharacteristic of other small streams. (Author 's abstract)

Allogenic and Autogenic Signals in the Stratigraphic Record of the Deep-Sea Bengal Fan.

PubMed

Blum, Mike; Rogers, Kimberly; Gleason, James; Najman, Yani; Cruz, Jarrett; Fox, Lyndsey

2018-05-22

The Himalayan-sourced Ganges-Brahmaputra river system and the deep-sea Bengal Fan represent Earth's largest sediment-dispersal system. Here we present detrital zircon U-Pb provenance data from Miocene to middle Pleistocene Bengal Fan turbidites, and evaluate the influence of allogenic forcing vs. autogenic processes on signal propagation from the Himalaya to the deep sea. Our data record the strong tectonic and climatic forcing characteristic of the Himalayan system: after up to 2500 km of river transport, and >1400 km of transport by turbidity currents, the U-Pb record faithfully represents Himalayan sources. Moreover, specific U-Pb populations record Miocene integration of the Brahmaputra drainage with the Asian plate, as well as the rapid Plio-Pleistocene incision through, and exhumation of, the eastern Himalayan syntaxis. The record is, however, biased towards glacial periods when rivers were extended across the shelf in response to climate-forced sea-level fall, and discharged directly to slope canyons. Finally, only part of the record represents a Ganges or Brahmaputra provenance end-member, and most samples represent mixing from the two systems. Mixing or the lack thereof likely represents the fingerprint of autogenic delta-plain avulsions, which result in the two rivers delivering sediment separately to a shelf-margin canyon or merging together as they do today.

Water Carcinogenicity and Prevalence of HPV Infection in Esophageal Cancer Patients in Huaihe River Basin, China

PubMed Central

Li, Jintao; Khodahemmati, Sara; Wang, Minglian; Wang, Yangjunqi; Zhao, Lijiao; Jia, Runqing; Chen, Su

2018-01-01

Objective The incidence of the upper gastrointestinal tumor has increased rapidly during recent decades. The relationship between local water pollution and the tumor is still not much clear, so this study was conducted to further investigate the local water pollution and its influence on the malignant cell transformation. Prevalence of human papillomavirus (HPV) in local esophageal cancer (EC) patients was also analyzed in Shenqiu County for the first time. Methods Two-step cell transformation was used to study different sources of water in the malignant cell transformation, and the existence of 3-methylcholanthrene (3-MC) in water was analyzed from the river and shallow and deep wells. HPV DNA in tissue samples of EC patients was detected by polymerase chain reaction (PCR) and HPV diagnostic kit. Results The river water has higher cytotoxicity than the shallow well water and induced significant cell malignant transformation, while deep well water has not shown the malignant cell transformation. In Huaihe River water, the 3-MC concentration was found higher than shallow and deep wells. An HPV infection rate was found high in patients with esophageal cancer. Conclusion Long-term consumption of polluted water can induce malignant cell transformation, and the presence of HPV may be an important cause of cancer. PMID:29853858

Landscape evolution in south-central Minnesota and the role of geomorphic history on modern erosional processes

USGS Publications Warehouse

Gran, K.B.; Belmont, P.; Day, S.S.; Finnegan, N.; Jennings, C.; Lauer, J.W.; Wilcock, P.R.

2011-01-01

The Minnesota River Valley was carved during catastrophic drainage of glacial Lake Agassiz at the end of the late Pleistocene. The ensuing base-level drop on tributaries created knickpoints that excavated deep valleys as they migrated upstream. A sediment budget compiled in one of these tributaries, the Le Sueur River, shows that these deep valleys are now the primary source of sediment to the Minnesota River. To compare modern sediment loads with pre-European settlement erosion rates, we analyzed incision history using fluvial terrace ages to constrain a valley incision model. Results indicate that even thoughthe dominant sediment sources are derived from natural sources (bluffs, ravines, and streambanks), erosion rates have increased substantially, due in part to pervasive changes in watershed hydrology.

Groundwater Discharges to Rivers in the Western Canadian Oil Sands Region

NASA Astrophysics Data System (ADS)

Ellis, J.; Jasechko, S.

2016-12-01

Groundwater discharges into rivers impacts the movement and fate of nutrients and contaminants in the environment. Understanding groundwater-surface water interactions is especially important in the western Canadian oil sands, where groundwater contamination risks are elevated and baseline water chemistry data is lacking, leading to substantial uncertainties about anthropogenic influences on local river quality. High salinity groundwater springs sourced from deep aquifers, comprised of Pleistocene-aged glacial meltwater, are known to discharge into many rivers in the oil sands. Understanding connections between deep aquifers and surficial waterways is important in order to determine natural inputs into these rivers and to assess the potential for injected wastewater or oil extraction fluids to enter surface waters. While these springs have been identified, their spatial distribution along rivers has not been fully characterized. Here we present river chemistry data collected along a number of major river corridors in the Canadian oil sands region. We show that saline groundwater springs vary spatially along the course of these rivers and tend to be concentrated where the rivers incise Devonian- or Cretaceous-aged aquifers along an evaporite dissolution front. Our results suggest that water sourced from Devonian aquifers may travel through bitumen-bearing Cretaceous units and discharge into local rivers, implying a strong groundwater-surface water connection in specialized locations. These findings indicate that oil sands process-affected waters that are injected at depth have the potential to move through these aquifers and reach the rivers at the surface at some time in the future. Groundwater-surface water interactions remain key to understanding the risks oil sands activities pose to aquatic ecosystems and downstream communities.

Detection of Flooding Responses at the River Basin Scale Enhanced by Land use Change

NASA Technical Reports Server (NTRS)

McCormick, Brian C.; Eshleman, Keith N.; Griffith, Jeff L.; Townsend, Philip A.

2009-01-01

The Georges Creek watershed (area 187.5 sq km) in western Maryland (United States) has experienced land use changes (>17% of area) associated with surface mining of coal. The adjacent Savage River watershed (area 127.2 sq km) is unmined. Moments of flood frequency distributions indicated that climatic variability affected both watersheds similarly. Normalizing annual maximum flows by antecedent streamflow and causative precipitation helped identify trends in flooding response. Analysis of contemporary storm events using Next Generation Weather Radar (NEXRAD) stage III precipitation data showed that Georges Creek floods are characterized by higher peak runoff and a shorter centroid lag than Savage River floods, likely attributable to differences in current land use. Interestingly, Georges Creek produces only two thirds of the storm-flow volume as Savage River, apparently because of infiltration into abandoned deep mine workings and an associated transbasin diversion constructed circa 1900. Empirical trend analysis is thus complicated by both hydroclimatic variability and the legacy of deep mining in the basin.

Adaption of egg and larvae sampling techniques for lake sturgeon and broadcast spawning fishes in a deep river

USGS Publications Warehouse

Roseman, Edward F.; Kennedy, Gregory W.; Craig, Jaquelyn; Boase, James; Soper, Karen

2011-01-01

In this report we describe how we adapted two techniques for sampling lake sturgeon (Acipenser fulvescens) and other fish early life history stages to meet our research needs in the Detroit River, a deep, flowing Great Lakes connecting channel. First, we developed a buoy-less method for sampling fish eggs and spawning activity using egg mats deployed on the river bottom. The buoy-less method allowed us to fish gear in areas frequented by boaters and recreational anglers, thus eliminating surface obstructions that interfered with recreational and boating activities. The buoy-less method also reduced gear loss due to drift when masses of floating aquatic vegetation would accumulate on buoys and lines, increasing the drag on the gear and pulling it downstream. Second, we adapted a D-frame drift net system formerly employed in shallow streams to assess larval lake sturgeon dispersal for use in the deeper (>8 m) Detroit River using an anchor and buoy system.

Adaption of egg and larvae sampling techniques for lake sturgeon and broadcast spawning fishes in a deep river

USGS Publications Warehouse

Roseman, E.F.; Boase, J.; Kennedy, G.; Craig, J.; Soper, K.

2011-01-01

In this report we describe how we adapted two techniques for sampling lake sturgeon (Acipenser fulvescens) and other fish early life history stages to meet our research needs in the Detroit River, a deep, flowing Great Lakes connecting channel. First, we developed a buoy-less method for sampling fish eggs and spawning activity using egg mats deployed on the river bottom. The buoy-less method allowed us to fish gear in areas frequented by boaters and recreational anglers, thus eliminating surface obstructions that interfered with recreational and boating activities. The buoy-less method also reduced gear loss due to drift when masses of floating aquatic vegetation would accumulate on buoys and lines, increasing the drag on the gear and pulling it downstream. Second, we adapted a D-frame drift net system formerly employed in shallow streams to assess larval lake sturgeon dispersal for use in the deeper (>8m) Detroit River using an anchor and buoy system. ?? 2011 Blackwell Verlag, Berlin.

A promising tool for subsurface permafrost mapping-An application of airborne geophysics from the Yukon River Basin, Alaska

USGS Publications Warehouse

Abraham, Jared E.

2011-01-01

In the area of Fort Yukon, the AEM survey shows elevated resistivities extending to depth, likely indicative of thick permafrost. This depth corresponds well to observations from a borehole drilled in the area in the late 1990s, which detected permafrost to a depth of about 100 meters (Clark and others, 2009). In contrast to the area of Fort Yukon, the Yukon River and its floodplain are not associated with deep resistive sediments, suggesting a lack of deep permafrost, at least within the depth range of the AEM mapping (fig. 3).

Occurrence, habitat, and movements of the endangered northern madtom (Noturus stigmosus) in the Detroit River, 2003-2011

USGS Publications Warehouse

Manny, Bruce A.; Daley, Bryon A.; Boase, James C.; Horne, Ashlee N.; Chiotti, Justin A.

2014-01-01

The northern madtom (Noturus stigmosus or NOM) is a small catfish, native to North America. It is globally vulnerable and endangered in Canada, Ontario, and Michigan. In 1994 and 1996, it was found in the St. Clair River and in Lake St. Clair, respectively. However, it had not been found downstream in the Detroit River since 1978. We report catches of 304 NOM from 2003 to 2011 and describe their mud and sand habitats in the deep (10 m), dark, Detroit River. We found adult NOM, including 3 ripe males (90–107 mm SL) in head waters of the river near Belle Isle in Michigan waters, and both adult and 4 juvenile NOM (21–30 mm SL) near Peche Island in Ontario waters. From 2009 to 2011, in the river's middle reach, we caught 7 adult NOM for the first time near Fighting Island in Ontario waters, but no NOM in the river's lower reach. Our mark–recapture results showed that within 6 weeks, 2 adult NOM moved east 2.0 km from Michigan waters near Belle Isle across the deep (10 m) Fleming Channel of the Detroit River to Canadian waters near Peche Island. Analysis of annuli from pectoral spines of 7 dead NOM revealed that they live to at least 6 years of age in the Detroit River. This is the first age data that we could find for a NOM population. Our findings extended our knowledge of habitat, reproductive ecology, age, and distribution of NOM in the Detroit River corridor.

Permafrost Mobilization from the Watershed to the Colville River Delta: Evidence from Biomarkers and 14C Ramped Pyrolysis

NASA Astrophysics Data System (ADS)

Zhang, X.; Bianchi, T. S.; Cui, X.; Rosenheim, B. E.; Ping, C. L.; Kanevskiy, M. Z.; Hanna, A. M.; Allison, M. A.

2016-12-01

As temperatures in the Arctic rise abnormally fast, permafrost in the region is vulnerable to extensive thawing. This could release previously frozen organic carbon (OC) into the contemporary carbon cycle, giving a positive feedback on global warming. Recent research has found the presence of particulate permafrost in rivers, deltas, and continental shelves in the Arctic, but little direct evidence exists on the mechanism of transportation of previously frozen soils from watershed to the coast. The Colville River in northern Alaska is the largest North American Arctic River with a continuous permafrost within its watershed. Previous work has found evidence for the deposition of previously frozen soils in the Colville River delta (Schreiner et al., 2014). Here, we compared the bulk organic carbon thermal properties, ages of soils and river and delta sediments from the Colville River drainage system using 14C Ramped Pyrolysis and chemical biomarkers. Our data show that deep permafrost soils as well as river and delta sediments had similar pyrograms and biomarker signatures, reflecting transport of soils from watershed to the delta. Surface soil had pyrograms indicative of less stable (more biodegradable) OC than deeper soil horizons. Similarity in pyrograms of deep soils and river sediment indicated the limited contribution of surface soils to riverine particulate OC inputs. Sediments in the delta showed inputs of yedoma (ice-rich syngenetic permafrost with large ice wedges) from the watershed sources (e.g., river bank erosion) in addition to peat inputs, that were largely from coastal erosion.

Crustal structure revealed by a deep seismic sounding profile of Baijing-Gaoming-Jinwan in the Pearl River Delta

NASA Astrophysics Data System (ADS)

Zhang, Xiang; Ye, Xiuwei; Lv, Jinshui; Sun, Jinlong; Wang, Xiaona

2018-02-01

The Pearl River Estuary area, located in the middle part of the southern China coastal seismic belt, has long been considered a potential source of strong earthquakes above magnitude 7.0. To scientifically assess the potential strong earthquake risk in this area, a three-dimensional artificial seismic sounding experiment, consisting of a receiving array and seabed seismograph, was performed to reveal the deep crustal structure in this region. We used artificial ship-borne air-gun excitation shots as sources, and fixed and mobile stations as receivers to record seismic data from May to August 2015. This paper presents results along a line from the western side of the Pearl River Estuary to the western side of the Baijing-Gaoming-Jinwan profile. A two-dimensional velocity structure was constructed using seismic travel-time tomography. The inversion results show that the Moho depth is 27 km in the coastal area and 30 km in the northwest of the Pearl River Estuary area, indicating that the crust thins from land to sea. Two structural discontinuities and multiple low-velocity anomalies appear in the crustal section. Inside both discontinuity zones, a low-velocity layer, with a minimum velocity of 6.05 km s-1, exists at a depth of about 15 km, and another, with a minimum velocity of 6.37 km s-1, exists at a depth of about 21.5 km between the middle and lower crust. These low velocities suggest that the discontinuities may consist of partly molten material. Earthquakes with magnitudes higher than 5.0 occurred in the low-velocity layer along the profile. The deep Kaiping-Enping fault, rooted in the crust, may be one of the most important channels for deep material upwelling and is related to tectonic movement since the Cretaceous in the Pearl River Delta tectonic rift basin.

Molecular signatures of biogeochemical transformations in dissolved organic matter from ten World Rivers

NASA Astrophysics Data System (ADS)

Riedel, Thomas; Zark, Maren; Vähätalo, Anssi; Niggemann, Jutta; Spencer, Robert; Hernes, Peter; Dittmar, Thorsten

2016-09-01

Rivers carry large amounts of dissolved organic matter (DOM) to the oceans thereby connecting terrestrial and marine element cycles. Photo-degradation in conjunction with microbial turnover is considered a major pathway by which terrigenous DOM is decomposed. To reveal globally relevant patterns behind this process, we performed photo-degradation experiments and year-long bio-assays on DOM from ten of the largest world rivers that collectively account for more than one-third of the fresh water discharge to the global ocean. We furthermore tested the hypothesis that the terrigenous component in deep ocean DOM may be far higher than biomarker studies suggest, because of the selective photochemical destruction of characteristic biomolecules from vascular plants. DOM was molecularly characterized by a combination of non-targeted ultrahigh-resolution mass spectrometry and quantitative molecular tracer analyses. We show that the reactivity of DOM is globally related to broad catchment properties. Basins that are dominated by forest and grassland export more photo-degradable DOM than other rivers. Chromophoric compounds are mainly vascular plant-derived polyphenols, and partially carry a pyrogenic signature from vegetation fires. These forest and grassland dominated rivers lost up to 50% of dissolved organic carbon (DOC) during irradiation, and up to 85% of DOC was lost in total if subsequently bio-incubated for one year. Basins covered by cropland, on the other hand, export DOM with a higher proportion of photo-resistant and bio-available DOM which is enriched in nitrogen. In these rivers, 30% or less of DOC was photodegraded. Consistent with previous studies, we found that riverine DOM resembled marine DOM in its broad molecular composition after extensive degradation, mainly due to almost complete removal of aromatics. More detailed molecular fingerprinting analysis (based on the relative abundance of >4000 DOM molecular formulae), however, revealed clear differences between degraded riverine and deep-sea DOM (molecular Bray-Curtis dissimilarity of 50%). None of our experimental treatments enhanced the molecular similarity between the rivers and the deep ocean. We conclude that terrigenous DOM retains a specific molecular signature during photo-degradation on much longer time scales than previously assumed and that substantial, thus far unknown, molecular transformations occur prior to downward convection into the deep oceanic basins.

Habitat use and movement patterns by adult saugers from fall to summer in an unimpounded small-river system

USGS Publications Warehouse

Kuhn, K.M.; Hubert, W.A.; Johnson, K.; Oberlie, D.; Dufek, D.

2008-01-01

The Little Wind River drainage in Wyoming is a relatively small unimpounded river system inhabited by native saugers Sander canadensis. Radio telemetry was used to assess habitat use and movement patterns by adult saugers in the river system from fall through early summer. Fifty-four adult saugers were captured during fall 2004, surgically implanted with radio transmitters, and tracked through mid-July 2005. Tagged saugers selected large and deep pools. Such pools were abundant throughout the Little Wind River system and led to saugers being widely dispersed from fall to early spring. During fall, winter, and early spring, tagged saugers remained sedentary and moved short distances among pools in close proximity to each other. Longer movements by tagged saugers occurred from mid-spring to early summer, and were associated with both upstream and downstream movements to and from two river segments believed to be used for spawning. During early summer, most saugers returned to locations where they had been tagged the previous fall and had spent the winter. Our results provide evidence that preservation of the sauger fishery in the Wind River system will depend on maintaining fish passage throughout the portion of the watershed inhabited by saugers and preserving natural fluvial processes that maintain large and deep pools. ?? Copyright by the American Fisheries Society 2008.

Deep-sea coral record of human impact on watershed quality in the Mississippi River Basin

USGS Publications Warehouse

Prouty, Nancy G.; Roark, E. Brendan; Koenig, Alan E.; Demopoulos, Amanda W. J.; Batista, Fabian C.; Kocar, Benjamin D.; Selby, David; McCarthy, Matthew D.; Mienis, Furu

2014-01-01

One of the greatest drivers of historical nutrient and sediment transport into the Gulf of Mexico is the unprecedented scale and intensity of land use change in the Mississippi River Basin. These landscape changes are linked to enhanced fluxes of carbon and nitrogen pollution from the Mississippi River, and persistent eutrophication and hypoxia in the northern Gulf of Mexico. Increased terrestrial runoff is one hypothesis for recent enrichment in bulk nitrogen isotope (δ15N) values, a tracer for nutrient source, observed in a Gulf of Mexico deep-sea coral record. However, unambiguously linking anthropogenic land use change to whole scale shifts in downstream Gulf of Mexico biogeochemical cycles is difficult. Here we present a novel approach, coupling a new tracer of agro-industrialization to a multiproxy record of nutrient loading in long-lived deep-sea corals collected in the Gulf of Mexico. We found that coral bulk δ15N values are enriched over the last 150–200 years relative to the last millennia, and compound-specific amino acid δ15N data indicate a strong increase in baseline δ15N of nitrate as the primary cause. Coral rhenium (Re) values are also strongly elevated during this period, suggesting that 34% of Re is of anthropogenic origin, consistent with Re enrichment in major world rivers. However, there are no pre-anthropogenic measurements of Re to confirm this observation. For the first time, an unprecedented record of natural and anthropogenic Re variability is documented through coral Re records. Taken together, these novel proxies link upstream changes in water quality to impacts on the deep-sea coral ecosystem.

Deep-sea coral record of human impact on watershed quality in the Mississippi River Basin

NASA Astrophysics Data System (ADS)

Prouty, N.; Roark, B.; Koenig, A.; Batista, F. C.; Kocar, B. D.; Selby, D. S.; Mccarthy, M. D.; Mienis, F.; Ross, S. W.; Demopoulos, A. W.

2015-12-01

One of the greatest drivers of historical nutrient and sediment transport into the Gulf of Mexico is the unprecedented scale and intensity of land use change in the Mississippi River Basin. These landscape changes are linked to enhanced fluxes of carbon and nitrogen pollution from the Mississippi River, and persistent eutrophication and hypoxia in the northern Gulf of Mexico. Increased terrestrial runoff is one hypothesis for recent enrichment in bulk nitrogen isotope (δ15N) values, a tracer for nutrient source, observed in a Gulf of Mexico deep-sea coral record. However, unambiguously linking anthropogenic land use change to whole scale shifts in downstream Gulf of Mexico biogeochemical cycles is difficult. Here we present a novel approach, coupling a new tracer of agro-industrialization to a multiproxy record of nutrient loading in long-lived deep-sea corals collected in the Gulf of Mexico. We found that coral bulk δ15N values are enriched over the last 150-200 years relative to the last millennia, and compound-specific amino acid δ15N data indicate a strong increase in baseline δ15N of nitrate as the primary cause. Coral rhenium (Re) values are also strongly elevated during this period, suggesting that 34% of Re is of anthropogenic origin, consistent with Re enrichment in major world rivers. However, there are no pre-anthropogenic measurements of Re to confirm this observation. For the first time, an unprecedented record of natural and anthropogenic Re variability is documented through coral Re records. Taken together, these novel proxies link upstream changes in water quality to impacts on the deep-sea coral ecosystem.

Deep-sea coral record of human impact on watershed quality in the Mississippi River Basin

NASA Astrophysics Data System (ADS)

Prouty, Nancy G.; Roark, E. Brendan; Koenig, Alan E.; Demopoulos, Amanda W. J.; Batista, Fabian C.; Kocar, Benjamin D.; Selby, David; McCarthy, Matthew D.; Mienis, Furu

2014-01-01

One of the greatest drivers of historical nutrient and sediment transport into the Gulf of Mexico is the unprecedented scale and intensity of land use change in the Mississippi River Basin. These landscape changes are linked to enhanced fluxes of carbon and nitrogen pollution from the Mississippi River, and persistent eutrophication and hypoxia in the northern Gulf of Mexico. Increased terrestrial runoff is one hypothesis for recent enrichment in bulk nitrogen isotope (δ15N) values, a tracer for nutrient source, observed in a Gulf of Mexico deep-sea coral record. However, unambiguously linking anthropogenic land use change to whole scale shifts in downstream Gulf of Mexico biogeochemical cycles is difficult. Here we present a novel approach, coupling a new tracer of agro-industrialization to a multiproxy record of nutrient loading in long-lived deep-sea corals collected in the Gulf of Mexico. We found that coral bulk δ15N values are enriched over the last 150-200 years relative to the last millennia, and compound-specific amino acid δ15N data indicate a strong increase in baseline δ15N of nitrate as the primary cause. Coral rhenium (Re) values are also strongly elevated during this period, suggesting that 34% of Re is of anthropogenic origin, consistent with Re enrichment in major world rivers. However, there are no pre-anthropogenic measurements of Re to confirm this observation. For the first time, an unprecedented record of natural and anthropogenic Re variability is documented through coral Re records. Taken together, these novel proxies link upstream changes in water quality to impacts on the deep-sea coral ecosystem.

INDICATOR OF EUTROPHICATION AND SEDIMENT LOAD: HYPERSPECTRAL TECHNIQUE FOR CONTINUOUS COVERAGE OF DEEP RIVERS

EPA Science Inventory

Remote sensing techniques were used to characterize and quantify spatial and temporal variation in water quality of the Great Miami River in Ohio. An initial feasibility study was conducted in the summer of 1999 using a non-imaging hand-held spectroradiometer to ascertain the pr...

Incorporating Lower Mississippi River port assets into emergency preparedness and response initiatives.

DOT National Transportation Integrated Search

2012-01-01

The Lower Mississippi River (LMR) and its 5 deep water ports represent a significant national asset as well as a critical portion of a major transportation corridor from the heartland of the country to the Gulf of Mexico. The lower portion of the Mis...

HYPERSPECTRAL TECHNIQUE AS AN INDICATOR OF EUTROPHICATION AND SEDIMENT LOAD FOR DEEP RIVERS

EPA Science Inventory

Remote sensing techniques were used to characterize and quantify spatial and temporal variation in water quality of the Great Miami River in Ohio. An initial feasibility study was conducted in the summer of 1999 using a non-imaging hand-held spectroradiometer to ascertain the pre...

Radon in the fluvial aquifers of the White River Basin, Indiana, 1995

USGS Publications Warehouse

Fenelon, Joseph M.; Moore, Rhett C.

1996-01-01

Water samples collected in 1995 from 57 monitoring wells (48 shallow and 9 deep) in the fluvial aquifers of the White River Basin were analyzed for radon. Radon concentrations in the shallow wells ranged from 140 to 1,600 pCi/L (picocuries per liter); the median concentration was 420 pCi/L. In comparison, analyses of the samples from the nine deep wells indicate that radon concentrations decrease with depth within the fluvial aquifers; the median concentration was 210 pCi/L. No areal trends in radon concentrations are evident in the water of the shallow fluvial aquifers of the basin

Aquatic Habitat Studies on the Lower Mississippi River, River Mile 480 to 530. Report 1. Introduction.

DTIC Science & Technology

1981-03-01

allidlllIiml-llaatl Ila 1,I1 1 It s Kud kes (I like f II s , iiit cvet I el htitksI i ri tte l(ir HlI,i ss 5I pp IP ki I ;IwIti it ob)c t ti ves...vegetated with mixed lowland trees, shrubs, and grasses. At its deepest point Lake Port was 17 ft deep; the upper one- third consisted of a shallow mud flat...Arkansas, and Washington County, Mississippi. Lake Lee was about 6 miles long, shallow at both ends, and up to 40 ft deep in the center two- thirds

Big River Reservoir Project. Pawcatuck River and Narragansett Bay Drainage Basins. Water and Related Land Resources Study. Volume I. Main Report.

DTIC Science & Technology

1981-07-01

blueberry , beech, laurel, wintergreen and scrub oak. Wetland types found in the study area include wooded and shrub swamps, deep and shallow marshes, and...temporary I Impacts io reservoir area, c) Les disruption in reservoir vicinity due to more negative Impacts in areas of pipeline river m02"t...19.7 miles of stream habitat (54.5% of the 36.2 nfiles in the big River Basin) Lnd at least IO small ponds totalling about 45 acres would be inundated

MODEL FROM COLLECTION OF DR. TIMOTHY L. FLINN, OF HOWE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MODEL FROM COLLECTION OF DR. TIMOTHY L. FLINN, OF HOWE PIPE TRUSS BRIDGE (NO LONGER EXTANT) SPANNING DEEP CREEK, SHACKELFORD COUNTY, TEXAS, CONSTRUCTED BY FLINN-MOYER COMPANY IN 1896. 3/4 VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

MODEL FROM COLLECTION OF DR. TIMOTHY L. FLINN, OF HOWE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MODEL FROM COLLECTION OF DR. TIMOTHY L. FLINN, OF HOWE PIPE TRUSS BRIDGE (NO LONGER EXTANT) SPANNING DEEP CREEK, SHACKELFORD COUNTY, TEXAS, CONSTRUCTED BY FLINN-MOYER COMPANY IN 1896. BARREL VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

MODEL FROM COLLECTION OF DR. TIMOTHY L. FLINN, OF HOWE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MODEL FROM COLLECTION OF DR. TIMOTHY L. FLINN, OF HOWE PIPE TRUSS BRIDGE (NO LONGER EXTANT) SPANNING DEEP CREEK, SHACKELFORD COUNTY, TEXAS, CONSTRUCTED BY FLINN-MOYER COMPANY IN 1896. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

78 FR 73186 - Wallowa-Whitman National Forests, Oregon; Lower Imnaha Rangeland Analysis

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-05

... Creek, Cow Creek, and a portion of the Snake River watersheds of the Hells Canyon National Recreation... associated watersheds downstream of the Imnaha River Bridge ``Cow Creek Bridge'', and watersheds from Deep... allotments: Cow Creek, Lone Pine, Rhodes Creek, and Toomey, all of which are in Wallowa County, Oregon. This...

Geothermal constraints on enrichment of boron and lithium in salt lakes: An example from a river-salt lake system on the northern slope of the eastern Kunlun Mountains, China

NASA Astrophysics Data System (ADS)

Tan, Hongbing; Chen, Jun; Rao, Wenbo; Zhang, Wenjie; Zhou, Huifang

2012-06-01

Some rivers on the northern slope of the eastern Kunlun Mountains in the Qaidam Basin, China, show very high concentrations of boron and lithium. Correspondingly, the salt lakes fed by these rivers show an unusual enrichment of boron and lithium, and become an important economic resource. The origin of boron and lithium has long been debated. The aim of this study is to analyze the water chemistry and hydrogen and oxygen isotopic composition of river water to understand the unusual enrichment of boron and lithium in the salt lakes of the Qaidam Basin. Oxygen and hydrogen isotope data show that the source of river water in the winter and summer originates from the Kunlun Mountain ice and snow melt water, respectively. The water chemistry shows that boron and lithium contents are high but little variable with seasons in the Nalenggele River and Wutumeiren River waters. By contrast, other rivers have much lower lithium and boron contents. Moreover, the contents of B3+ and Li+ in the river loads or bed sands show little difference amongst the rivers. This indicates that removal by adsorption or input by surface rock weathering is not the main controlling factor of the B3+ and Li+ variation in the rivers. Rivers with high B3+ and Li+ content are chemically similar to geothermal waters in the Tibetan Plateau. In addition, the source area of the Nalenggele River is located in a collision zone of the Kunlun Mountains and Altun Mountains. Large and deep faults can serve as conduits for geothermal fluids. Thus, deep geothermal waters in the source area can easily migrate to the surface and discharge as springs feeding the rivers. They are an important source of B3+ and Li+ to the rivers. The abnormally high contents of B3+ and Li+ in the Nalenggele and Wutumeiren Rivers also suggest that the geothermal source area may be a future target for boron and lithium resources.

Seasonal movement and habitat use by sub-adult bull trout in the upper Flathead River system, Montana

USGS Publications Warehouse

Muhlfeld, Clint C.; Marotz, Brian

2005-01-01

Despite the importance of large-scale habitat connectivity to the threatened bull trout Salvelinus confluentus, little is known about the life history characteristics and processes influencing natural dispersal of migratory populations. We used radiotelemetry to investigate the seasonal movements and habitat use by subadult bull trout (i.e., fish that emigrated from natal streams to the river system) tracked for varying durations from 1999 to 2002 in the upper Flathead River system in northwestern Montana. Telemetry data revealed migratory (N = 32 fish) and nonmigratory (N = 35 fish) behavior, indicating variable movement patterns in the subadult phase of bull trout life history. Most migrating subadults (84%) made rapid or incremental downriver movements (mean distance, 33 km; range, 6–129 km) to lower portions of the river system and to Flathead Lake during high spring flows and as temperatures declined in the fall and winter. Bull trout subadults used complex daytime habitat throughout the upper river system, including deep runs that contained unembedded boulder and cobble substrates, pools with large woody debris, and deep lake-influenced areas of the lower river system. Our results elucidate the importance of maintaining natural connections and a diversity of complex habitats over a large spatial scale to conserve the full expression of life history traits and processes influencing the natural dispersal of bull trout populations. Managers should seek to restore and enhance critical river corridor habitat and remove migration barriers, where possible, for recovery and management programs.

Impact of reclaimed water in the watercourse of Huai River on groundwater from Chaobai River basin, Northern China

NASA Astrophysics Data System (ADS)

Yu, Yilei; Song, Xianfang; Zhang, Yinghua; Zheng, Fandong; Liu, Licai

2017-12-01

Reclaimed water is efficient for replenishing the dry rivers in northern China, but regional groundwater may be at risk from pollution. Therefore, samples of reclaimed water, river water, and groundwater were collected at the Huai River in the Chaobai River basin in 2010. The water chemistry and isotopic compositions of the samples were analyzed in the laboratory. The reclaimed water had stable compositions of water chemistry and isotopes, and the Na·Ca-HCO3·Cl water type. The water chemistry of the river water was consistent with that of the reclaimed water. A June peak of total nitrogen was the prominent characteristic in the shallow groundwater, which also had the Na·Ca-HCO3·Cl water type. However, the water chemistry and isotopes in most of the deep groundwater remained stable, and the water type was Ca·Mg-HCO3. The amount of reclaimed water recharging the groundwater was about 2.5 × 107 m3/yr. All of the shallow groundwater was impacted by the reclaimed water, with the mixing proportion of reclaimed water ranging from 42% to 80 % in the dry season and from 20% to 86% in the wet season. Only one deep well, with proportions of 67% (dry season) and 28% (wet season), was impacted. TDS, EC, and major ions (Na, K, Cl, NH4-N, NO2-N, and NO3-N) were increased in the impacted wells.

Hydrological and pollution processes in mining area of Fenhe River Basin in China.

PubMed

Yang, Yonggang; Meng, Zhilong; Jiao, Wentao

2018-03-01

The hydrological and pollution processes are an important science problem for aquatic ecosystem. In this study, the samples of river water, reservoir water, shallow groundwater, deep groundwater, and precipitation in mining area are collected and analyzed. δD and δ 18 O are used to identify hydrological process. δ 15 N-NO 3 - and δ 18 O-NO 3 - are used to identify the sources and pollution process of NO 3 - . The results show that the various water bodies in Fenhe River Basin are slightly alkaline water. The ions in the water mainly come from rock weathering. The concentration of SO 4 2- is high due to the impact of coal mining activity. Deep groundwater is significantly less affected by evaporation and human activity, which is recharged by archaic groundwater. There are recharge and discharge between reservoir water, river water, soil water, and shallow groundwater. NO 3 - is the main N species in the study area, and forty-six percent of NO 3 - -N concentrations exceed the drinking water standard of China (NO 3 - -N ≤ 10 mg/L content). Nitrification is the main forming process of NO 3 - . Denitrification is also found in river water of some river branches. The sources of NO 3 - are mainly controlled by land use type along the riverbank. NO 3 - of river water in the upper reaches are come from nitrogen in precipitation and soil organic N. River water in the lower reaches is polluted by a mixture of soil organic N and fertilizers. Copyright © 2017 Elsevier Ltd. All rights reserved.

A post-Calumet shoreline along southern Lake Michigan

USGS Publications Warehouse

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

2007-01-01

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

The Geomorphology, Hydrology and Evolution of a Chain of Ponds River System: A Poorly Recognised and Unique River Planform Type.

NASA Astrophysics Data System (ADS)

Williams, R.; Fryirs, K.

2016-12-01

Chain-of-ponds river types are alluvial, discontinuous watercourses that contain irregularly spaced, deep, steep-sided ponds separated by an ephemeral flow path. Despite being widespread, chains of ponds are now rare in Australia, having experienced extensive channelisation since European settlement and landuse intensification. The Mulwaree system is one of the largest remaining chain of ponds systems in the country. Little is known about its geomorphic structure, Quaternary evolution or hydrological function. The valley fill of the Mulwaree River contains layers of gravel and cobble clast-supported sediments at a depth of 20 m. Atop, silt and fine sand sediments are 1-3 m deep. The ponds, which sit in this valley-fill, are large (1000-4000 m2 and up to 8 m deep), and are relic form from a much larger and more energetic gravel-bed river that occurred in this valley in the past. Optically-stimulated luminescence ages date the change from high-energy gravel bed to the very low energy system seen today at approximately 20-25 ka. The oldest dates for the gravel bed system at 5-7 m deep are 60-90 ka. The coarser substrate beneath the fine-grained floodplain is mostly saturated, forming a near-surface aquifer in the valley fill/floodplain. The water levels in the floodplain are similar to the level of the adjacent ponds (within 0.2 m) and this water level adjusts readily (within 0.5-2 days) to rain/flow. There is significant hydrological connectivity between the ponds and adjacent floodplain. During high flow conditions, stable isotope (δ18O and δ2H) results from the ponds show no deviation through the profile as the water column is being mixed. However, during low-flow conditions, water in the ponds is enriched near the surface due to evaporation, and has a similar signal to the adjacent near-surface, floodplain aquifer below a weak thermocline. This shows that these systems have a dual function, behaving more as groundwater dependent systems during low flow conditions, and surface water dependent systems during high flow. Understanding the unique hydro-geomorphic structure and evolution of this discontinuous watercourse is important as it provides a framework for its ecological function and increases our knowledge of river geodiversity.

The influence of seasonal climate on the morphology of the mouth-bar in the Yangtze Estuary, China

NASA Astrophysics Data System (ADS)

Zhang, Min; Townend, Ian; Cai, Huayang; He, Jiawei; Mei, Xuefei

2018-02-01

The geomorphology of the Yangtze Estuary in the Changjiang River Delta in Eastern China has been the subject of extensive research. This study extends previous work to examine the influence of wind-waves on the mouth-bar, where about half of the river-borne material settles to the bed. The site is located just outside of Changjiang River mouth, which is meso-tidal and subject to seasonally varying river flows and wind-wave conditions. Modeling was performed with a coupled wave-current hydrodynamic model using TELEMAC and TOMAWAC and validated against observed data. Bottom Shear Stress (BSS) from river, tide and waves based on the numerical model output was used to infer the respective contribution to the evolution of the subaqueous delta. Our examination did not however extend to modeling the sediment transport or the morphological bed changes. The results suggest that (i) the dominance of river discharge is limited to an area inside the mouth, while outside, the mouth-bar is tide-wave dominant; (ii) considering just the tide, the currents on the shallow shoals are flood dominant and deep channels are ebb dominant, which induces continued accretion over the shallows and erodes the deeper parts of the mouth-bar until the tidal currents become too weak to transport sediment; (iii) whereas waves are very efficient at reshaping the shallow shoals, with the effect being subtly dependent on the depth distribution over the mouth-bar; (iv) the stability of shallow shoal morphology is highly dependent on the presence of seasonal wind-waves and characterized as "summer storing and winter erosion", while deep channels perform like corridors of water and sediment, exporting sediment all year round. The nature of the mouth-bar response has important implications for coastal management, such as the ongoing deep water channel maintenance, reclamations and coastal defense measures.

A generalised model of secondary circulation for a wide range of geophysical flows from direct observations of natural turbidity currents

NASA Astrophysics Data System (ADS)

Azpiroz, M.; Cartigny, M.; Sumner, E. J.; Talling, P.; Parsons, D. R.; Clare, M. A.; Cooper, C.

2017-12-01

Turbidity currents transport sediment through submarine channel systems for hundreds of kilometres to form vast deposits of sediment in the deep sea called submarine fans. The largest submarine fans are fed by meandering channels suggesting that bends may enhance sediment transport distances. The interaction between meander bends and turbidity currents has been a topic of intense debate. Due to the absence of observations of deep-sea turbidity currents flowing through meander bends, our understanding has been based on experimental and numerical models. Measurements of geophysical flows demonstrate a common helical flow structure around meanders. Previous work has demonstrated that helical circulation in rivers is dominated by a single helix that rotates towards the inner bend at near-bed depths. In contrast, initial numerical and experimental models for turbidity currents found both river-like and river-reversed circulations. Saline flows in well-mixed estuaries show a river-like basal helical circulation, while stratified estuaries and saline flows are river-reversed. The existence of lateral stratification in stratified flows is thought to be the key factor in the change of direction of rotation. Stratification causes lateral pressure gradients that can govern the rotation of the flow helix. Turbidity currents are stratified due to their upwards-decreasing sediment load. It has therefore been proposed that stratified turbidity currents behave like stratified saline flow, but this hypothesis remains so far untested. Here we present the first observations of the helical flow in turbidity currents, which occurred within the deep-sea Congo Canyon. The measurements show a consistent river-reversed pattern downstream of the bend apex. Those results lead us to develop a new generalised model for a wide range of flows around meanders. Our conclusions have implications for understanding the flow erosional and depositional patterns, the evolution of channel systems and the architecture of the depositional record.

Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 2003-2004 Annual Report.

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

Walters, Jody P.

2005-08-01

Rainbow trout Oncorhynchus mykiss provide the most important sport fishery in the Kootenai River, Idaho, but densities and catch rates are low. Low recruitment is one possible factor limiting the rainbow trout population. Bull trout Salvelinus confluentus also exist in the Kootenai River, but little is known about this population. Research reported here addresses the following objectives for the Kootenai River, Idaho: identify sources of rainbow and bull trout recruitment, monitor the rainbow trout population size structure to evaluate regulation changes initiated in 2002, and identify factors potentially limiting rainbow trout recruitment. A screw trap was used to estimate juvenilemore » redband and bull trout out-migration from the Callahan Creek drainage, and electrofishing was conducted to estimate summer densities of bull trout rearing in the Idaho portion of the drainage. An estimated 1,132 juvenile redband trout and 68 juvenile bull trout out-migrated from Callahan Creek to the Kootenai River from April 7 through July 15, 2003. Densities of bull trout {ge} age-1 in North and South Callahan creeks ranged from 1.6 to 7.7 fish/100m{sup 2} in August. Bull trout redd surveys were conducted in North and South Callahan creeks, Boulder Creek, and Myrtle Creek. Thirty-two bull trout redds were located in North Callahan Creek, while 10 redds were found in South Callahan Creek. No redds were found in the other two streams. Modeling of culverts in the Deep Creek drainage identified two as upstream migration barriers, preventing rainbow trout from reaching spawning and rearing habitat. Water temperature monitoring in Deep Creek identified two sites where maximum temperatures exceeded those suitable for rainbow trout. Boulder Creek produces the most rainbow trout recruits to the Kootenai River in Idaho upstream of Deep Creek, but may be below carrying capacity for rearing rainbow trout due to nutrient limitations. Monthly water samples indicate Boulder Creek is nutrient limited as soluble reactive and total dissolved phosphorus were typically at or below detection limits, and dissolved inorganic nitrogen concentrations were <30 {micro}/L. A fall 2003 electrofishing survey of the Kootenai River rainbow trout population showed that the proportional stock density (55) and quality stock density (6) increased for the second year in a row following implementation of more conservative harvest regulations. North and South Callahan creeks support the largest spawning population of bull trout in the Kootenai River drainage, Idaho, so management of the watershed should consider bull trout as high priority. Monitoring of the Kootenai River rainbow trout population size structure should continue for at least two to three years to help evaluate the conservative harvest regulations. Finally, options to improve or increase access to rainbow trout spawning and rearing habitat in the Deep Creek drainage should be investigated.« less

MODEL FROM COLLECTION OF DR. TIMOTHY L. FLINN, OF HOWE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MODEL FROM COLLECTION OF DR. TIMOTHY L. FLINN, OF HOWE PIPE TRUSS BRIDGE (NO LONGER EXTANT) SPANNING DEEP CREEK, SHACKELFORD COUNTY, TEXAS, CONSTRUCTED BY FLINN-MOYER COMPANY IN 1896. 3/4 VIEW FROM ABOVE. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

Origin and distribution of the organic matter in the distal lobe of the Congo deep-sea fan - A Rock-Eval survey

NASA Astrophysics Data System (ADS)

Baudin, François; Stetten, Elsa; Schnyder, Johann; Charlier, Karine; Martinez, Philippe; Dennielou, Bernard; Droz, Laurence

2017-08-01

The Congo River, the second largest river in the world, is a major source of organic matter for the deep Atlantic Ocean because of the connection of its estuary to the deep offshore area by a submarine canyon which feeds a vast deep-sea fan. The lobe zone of this deep-sea fan is the final receptacle of the sedimentary inputs presently channelled by the canyon and covers an area of 2500 km². The quantity and the source of organic matter preserved in recent turbiditic sediments from the distal lobe of the Congo deep-sea fan were assessed using Rock-Eval pyrolysis analyses. Six sites, located at approximately 5000 m water-depth, were investigated. The mud-rich sediments of the distal lobe contain high amounts of organic matter ( 3.5 to 4% Corg), the origin of which is a mixture of terrestrial higher-plant debris, soil organic matter and deeply oxidized phytoplanktonic material. Although the respective contribution of terrestrial and marine sources of organic matter cannot be precisely quantified using Rock-Eval analyses, the terrestrial fraction is dominant according to similar hydrogen and oxygen indices of both suspended and bedload sediments from the Congo River and that deposited in the lobe complex. The Rock-Eval signature supports the 70% to 80% of the terrestrial fraction previously estimated using C/N and δ13Corg data. In the background sediment, the organic matter distribution is homogeneous at different scales, from a single turbiditic event to the entire lobe, and changes in accumulation rates only have a limited effect on the quantity and quality of the preserved organic matter. Peculiar areas with chemosynthetic bivalves and/or bacterial mats, explored using ROV Victor 6000, show a Rock-Eval signature similar to background sediment. This high organic carbon content associated to high sedimentation rates (> 2 to 20 mm.yr-1) in the Congo distal lobe complex implies a high burial rate for organic carbon. Consequently, the Congo deep-sea fan represents an enormous sink of terrestrial organic matter when compared to other turbiditic systems over the world.

Deep River Velocity and Sediment Profiles and the Suspended Sand Load,

DTIC Science & Technology

1963-02-01

sippi / ( I D DC 11 Prepared for Federal Interagency Sedimentation Conference of the Subcommittee on Sedimentation, ICWR Jackson, Mississippi 28 January-i...in the Atchaf- a]. aya River at Simmesport and in the Mississippi River at Vicksburg to de- fine the vertical velocity distribution. Examination of...l.l5~~(~~) (1) in which y is distance above the bed, d is the depth of a mean-depth A 14 -- - - section, i~ is the average velocity of flow in the

Seismic evidence of glacial-age river incision into the Tahaa barrier reef, French Polynesia

USGS Publications Warehouse

Toomey, Michael; Woodruff, Jonathan D.; Ashton, Andrew D.; Perron, J. Taylor

2016-01-01

Rivers have long been recognized for their ability to shape reef-bound volcanic islands. On the time-scale of glacial–interglacial sea-level cycles, fluvial incision of exposed barrier reef lagoons may compete with constructional coral growth to shape the coastal geomorphology of ocean islands. However, overprinting of Pleistocene landscapes by Holocene erosion or sedimentation has largely obscured the role lowstand river incision may have played in developing the deep lagoons typical of modern barrier reefs. Here we use high-resolution seismic imagery and core stratigraphy to examine how erosion and/or deposition by upland drainage networks has shaped coastal morphology on Tahaa, a barrier reef-bound island located along the Society Islands hotspot chain in French Polynesia. At Tahaa, we find that many channels, incised into the lagoon floor during Pleistocene sea-level lowstands, are located near the mouths of upstream terrestrial drainages. Steeper antecedent topography appears to have enhanced lowstand fluvial erosion along Tahaa's southwestern coast and maintained a deep pass. During highstands, upland drainages appear to contribute little sediment to refilling accommodation space in the lagoon. Rather, the flushing of fine carbonate sediment out of incised fluvial channels by storms and currents appears to have limited lagoonal infilling and further reinforced development of deep barrier reef lagoons during periods of highstand submersion.

Blubber morphology in wild bottlenose dolphins (Tursiops truncatus) from the Southeastern United States: influence of geographic location, age class, and reproductive state.

PubMed

Montie, Eric W; Garvin, Scott R; Fair, Patricia A; Bossart, Gregory D; Mitchum, Greg B; McFee, Wayne E; Speakman, Todd; Starczak, Victoria R; Hahn, Mark E

2008-04-01

This study investigated blubber morphology and correlations of histological measurements with ontogeny, geography, and reproductive state in live, wild bottlenose dolphins (Tursiops truncatus) from the southeastern United States. Surgical skin-blubber biopsies (N=74) were collected from dolphins during capture-release studies conducted in two geographic locations: Charleston, SC (N=38) and Indian River Lagoon, FL (N=36). Histological analysis of blubber revealed stratification into superficial, middle, and deep layers. Adipocytes of the middle blubber were 1.6x larger in Charleston subadults than in Indian River Lagoon subadults (4,590+/-340 compared to 2,833+/-335 microm2 per cell). Charleston subadult dolphins contained higher levels of total blubber lipids than Charleston adult animals (49.3%+/-1.9% compared to 34.2%+/-1.7%), and this difference was manifested in more adipocytes in the middle blubber layer (19.2+/-0.9 compared to 14.9+/-0.5 cells per field). However, dolphins from Indian River Lagoon did not exhibit this pattern, and the adipocyte cell counts of subadults were approximately equal to those of the adults (16.0+/-1.4 compared to 13.4+/-0.8 cells per field). The colder year-round water temperatures in Charleston compared to Indian River Lagoon may explain these differences. Adipocytes in the deep blubber layer were significantly smaller in lactating and simultaneously pregnant and lactating animals compared to pregnant dolphins (840+/-179, 627+/-333, and 2,776+/-586 microm2 per cell, respectively). Total blubber lipid content and adipocyte size in the deep blubber of mothers with calves decreased linearly with calf length. Lactating females may utilize lipids from the deep blubber during periods of increased energetic demands associated with offspring care. This study demonstrates that ontogeny, geography, and reproductive state may influence morphological parameters such as structural fiber densities and adipocyte numbers and sizes, measured in bottlenose dolphin blubber. Copyright (c) 2007 Wiley-Liss, Inc.

Assessment of metal and nutrient concentrations in river water and sediment collected from the cities in the Pearl River Delta, South China.

PubMed

Cheung, K C; Poon, B H T; Lan, C Y; Wong, M H

2003-09-01

The effects of anthropogenic activities, industrialization and urbanization on the accumulation of heavy metals and nutrients in sediments and water of rivers in the Pearl River Delta region were examined. Most sediments were seriously contaminated with Cd, Pb, and Zn in accordance with the classification by Hong Kong Environmental Protection Department. Total phosphorus (P) and nitrogen (N) concentrations in sediments ranged from 0.02% to 0.12% and 0.06% to 0.64%, respectively. High carbon (C), N, P and sulphur (S) levels at Yuen Long Creek were related to the discharge of industrial effluents along the river. The enrichment of P and ammoniacal-nitrogen (NH4+-N) in water were obvious. For most sites, the P concentration exceeded 0.1 mg/l, which is the recommended concentration in flowing water to encourage excessive growth of aquatic plants. Nine out of the 16 sites studied had NH4+-N concentration over 2 mg/l. The rivers in the south of Deep Bay (Hong Kong) had high nutrient exports compared with the rivers in the east region and western oceanic water. The concentrations of nitrate-nitrogen NO3--N in surface water were under the maximum contaminant level in public drinking water supplies (10 mg/l) except for one site. Although the concentrations of heavy metals in overlying water were low, their accumulations were significant. High contents of nickel (Ni) and zinc (Zn) in water were found at certain locations, suggesting the occurrence of some local contamination. These preliminary results indicated that river and sediment transported pollutants is likely one of the factors for the water quality degradation of Deep Bay water.

Temporal Differences in Flow Depth and Velocity Distributions and Hydraulic Microhabitats Near Bridges of the Lower Platte River, Nebraska, 1934-2006

USGS Publications Warehouse

Ginting, Daniel; Zelt, Ronald B.

2008-01-01

As part of a collaborative study of the cumulative impacts on stream and riparian ecology of water and channel management practices in the lower Platte River, Nebraska, this report describes a study by the U.S. Geological Survey in cooperation with the Lower Platte South Natural Resources District that summarizes: (1) temporal differences in distribution of streamflow depth, velocity, and microhabitats among five discrete 11-water-year periods 1934-44, 1951-61, 1966-76, 1985-95, and 1996-2006, and (2) the effects of bridge proximity on distribution of streamflow depth, velocity, and microhabitat of the Platte River when cross sections were measured at a similar discharge. The scope of the study included the four presently (2008) active streamflow-gaging stations located near bridges over the lower Platte River at North Bend, near Leshara, near Ashland, and at Louisville, Nebraska, and the most downstream streamflow-gaging station within the central Platte River segment near Duncan, Nebraska. Generally, in cases where temporal differences in streamflow depth and velocity were evident, at least one of the water-year periods from 1934 through 1995 had deeper streamflow than the recent water-year period (1996-2006). Temporal differences in distributions of streamflow depth were not strongly associated with differences in either climatic conditions or the maximum peak flow that occurred prior to the latest discharge measurement during each period. The relative cross-sectional area of most hydraulic niches did not differ among the water-year periods. Part of this apparent uniformity likely was an artifact of the broad microhabitat classification used for this study. In cases where temporal differences in relative cross-sectional area of hydraulic niches were evidenced, the differences occurred during high- and low-flow conditions, not during median flow conditions. The temporal differences in relative cross-sectional area were found more frequently for hydraulic niches defined by moderate and fast velocities than for hydraulic niches defined by slow velocities. Generally, any significant increase or decrease in the relative cross-sectional areas of hydraulic niches during the water-year periods from 1934 through 1995 had disappeared during the most recent water-year period, 1996-2006. Deep-Swift niche was the predominant hydraulic niche for all near-bridge sites on the lower Platte River for high- and median-flow conditions. The Deep-Swift niche also was the predominant niche for the near-bridge sites near Ashland and at Louisville for low-flow conditions; for the near-bridge sites at North Bend and near Leshara, streamflow cross-sectional areas during low-flow conditions were shared among the Shallow-Moderate, Intermediate-Moderate, Intermediate-Swift, and Deep-Swift hydraulic niches. For the near-bridge site near Duncan, the site farthest downstream in the central Platte River system, the Deep-Swift hydraulic niche was predominant only during high-flow conditions; during median- and low-flow conditions the relative cross-sectional area was shared among the Shallow-Slow, Shallow-Moderate, Intermediate-Moderate, and Intermediate-Swift hydraulic niches. Significant temporal differences in the relative cross-sectional area of the Deep-Swift hydraulic niche were found for sites near the two farthest downstream bridges near Ashland and at Louisville, but only for low-flow conditions. The Deep-Swift microhabitat was of special interest because it is the preferred hydraulic habitat during the adult life of the endangered pallid sturgeon (Scaphirhynchus albus). Temporal differences in relative cross-sectional areas of the Glide low-flow geomorphic microhabitat that contained the Deep-Swift hydraulic niche also indicated that relative cross-sectional areas of the Glide during the 1951-61 and 1996-2006 water-year periods were lower than during the 1966-76 period. The temporal differences indicated that any significant temporal chang

A Precise 6 Ma Start Date for Fluvial Incision of the Northeastern Colorado Plateau Canyonlands

NASA Astrophysics Data System (ADS)

Thomson, S. N.; Soreghan, G. S.; Reiners, P. W.; Peyton, S. L.; Murray, K. E.

2015-12-01

Outstanding questions regarding late Cenozoic Colorado Plateau landscape evolution include: (1) the relative roles of isostatic rebound as result Colorado River incision versus longer-term geodynamic processes in driving overall rock uplift of the plateau; and (2) whether incision was triggered by river integration or by a change in deep-seated mantle lithosphere dynamics. A key to answering these questions is to date more precisely the onset of incision to refine previous estimates of between 6 and 10 Ma. We present new low-temperature thermochronologic results from bedrock and deep borehole samples in the northeastern Colorado Plateau to show that rapid river incision began here at 6 Ma (5.93±0.66 Ma) with incision rates increasing from 15-50 m/Myr to 160-200 m/Myr. The onset time is constrained independently by both inverse time-temperature modeling and by the break-in-slope in fission track age-elevation relationships. This new time constraint has several important implications. First, the coincidence in time with 5.97-5.3 Ma integration of the lower Colorado River through the Grand Canyon to the Gulf of California strongly favors downstream river integration triggering carving of the canyonlands of the upper Colorado River system. Second, it implies integration of the entire Colorado River system in less than 2 million years. Third, rock uplift of the plateau driven by the flexural isostatic response to river incision is restricted to just the last 6 Ma, as is associated increased sediment budget. Fourth, incision starting at 6 Ma means that previous estimates of upper Colorado River incision rates based on 10-12 Ma basalt datum levels are too low. This also changes the dependency of measured time interval on incision rate from a non-steady-state negative power-law dependence (exponent of -0.24) to a near steady-state dependence (exponent of 0.07) meaning that long-term upper Colorado river incision rates can provide a reliable proxy for rock uplift rates.

Basin characterization and determination of hydraulic connectivity of mega basins using integrated methods: (The case of Baro-Akobo and mega watershed beyond)

NASA Astrophysics Data System (ADS)

Alemayehu, Taye; Kebede, Tesfaye; Liu, Lanbo

2018-01-01

Despite being the longest river and the fourth in drainage area, Nile River has the lowest discharge per unit areas among the top ten rivers of the world. Understanding the hydrologic significance of the regional litho-stratigraphy and structures help to better understand the hydrodynamics. This work is aimed at characterizing the Baro-Akobo-Sobbat sub-basin of Nile and determine trans-basin flows. Integrated method is used to characterize the basin and determine the Baro-Akobo-Sobbat sub-basin's relationship with African Mesozoic Rifts. Oil and water well drilling logs; aeromagnetic, gravity and vertical electrical sounding data; and various study reports are used to establish regional lithostratigraphic correlations and determine trans-regional hydrogeological connectivity. A total of 633 samples collected from wells, springs, rivers, lakes, swamps and rain water are analysed for their chemical, stable isotopes, tritium and radon properties. The Baro-Akobo river basin is commonly presumed to have good groundwater potential, particularly in its lowland plain. However, it has poor exploitable groundwater potential and recharge rate due to the extensive clay cover, limited retention capacity and the loss of the bulk of the groundwaters through regional geological structures to the deep seated continental sediments; presumably reaching the hydraulically connected African Mesozoic Rifts; mainly Melut and Muglad. The deep underground northward flows, along Nile River is, presumably, retarded by Central African Shear Zone in the Sudan.

Timing and process of river and lake terrace formation in the Kyrgyz Tien Shan

NASA Astrophysics Data System (ADS)

Burgette, Reed J.; Weldon, Ray J.; Abdrakhmatov, Kanatbek Ye.; Ormukov, Cholponbek; Owen, Lewis A.; Thompson, Stephen C.

2017-03-01

Well-preserved flights of river and lake terraces traverse an actively deforming rangefront, and form a link between glaciated mountains and a large intermontane lake in the Issyk-Kul basin of the Kyrgyz Tien Shan. We investigated the history and geometry of these lake and river terraces using geologic mapping, surveying, and radiocarbon and terrestrial cosmogenic nuclide dating. A prominent late Pleistocene highstand of the lake occurred over at least the period of 43-25 ka, followed by a period of deep regression and subsequent rise of the lake to the modern sill level in the late Holocene. Major aggradation of the most prominent latest Quaternary river terrace along the Ak-Terek and Barskaun rivers likely started at ∼70-60 ka, coincident to the local last glacial maximum in this region. In contrast to some models of aggradation and incision, the rivers appear to have stayed near the top of the fill for >20 ka, incising subtly below the top of this fill by ∼37 ka, locally. Deep incision likely did not occur until the peak deglaciation in the latest Pleistocene. Older dated terrace surfaces are consistent with one major terrace-forming event per glacial, constant deformation and incision rates, and typical fluvial gradients lower than the modern incising streams. The dating confirms regional terrace correlations for the most prominent late Quaternary terraces, but correlating higher terraces is complicated by spatially varying uplift rates and preferential terrace preservation between basins in the Tien Shan.

Selective Phylogenetic Analysis Targeted at 16S rRNA Genes of Thermophiles and Hyperthermophiles in Deep-Subsurface Geothermal Environments

PubMed Central

Kimura, Hiroyuki; Sugihara, Maki; Kato, Kenji; Hanada, Satoshi

2006-01-01

Deep-subsurface samples obtained by deep drilling are likely to be contaminated with mesophilic microorganisms in the drilling fluid, and this could affect determination of the community structure of the geothermal microflora using 16S rRNA gene clone library analysis. To eliminate possible contamination by PCR-amplified 16S rRNA genes from mesophiles, a combined thermal denaturation and enzyme digestion method, based on a strong correlation between the G+C content of the 16S rRNA gene and the optimum growth temperatures of most known prokaryotic cultures, was used prior to clone library construction. To validate this technique, hot spring fluid (76°C) and river water (14°C) were used to mimic a deep-subsurface sample contaminated with drilling fluid. After DNA extraction and PCR amplification of the 16S rRNA genes from individual samples separately, the amplified products from river water were observed to be denatured at 82°C and completely digested by exonuclease I (Exo I), while the amplified products from hot spring fluid remained intact after denaturation at 84°C and enzyme digestion with Exo I. DNAs extracted from the two samples were mixed and used as a template for amplification of the 16S rRNA genes. The amplified rRNA genes were denatured at 84°C and digested with Exo I before clone library construction. The results indicated that the 16S rRNA gene sequences from the river water were almost completely eliminated, whereas those from the hot spring fluid remained. PMID:16391020

Heated Discharge Control and Management Alternatives: Small Water Bodies and Rivers.

ERIC Educational Resources Information Center

MacLaren, James F.

Basic concepts of waste heat management on shallow and deep small water bodies and rivers are reviewed and examples are given. This study defines a small water body as a body in which the far field hydrothermal effects of a heated discharge can be detected in a major portion or practically all of the water body. Environmental effects due to…

The Impact of the Aerosol Direct Radiative Forcing on Deep Convection and Air Quality in the Pearl River Delta Region

NASA Astrophysics Data System (ADS)

Liu, Z.; Yim, Steve H. L.; Wang, C.; Lau, N. C.

2018-05-01

Literature has reported the remarkable aerosol impact on low-level cloud by direct radiative forcing (DRF). Impacts on middle-upper troposphere cloud are not yet fully understood, even though this knowledge is important for regions with a large spatial heterogeneity of emissions and aerosol concentration. We assess the aerosol DRF and its cloud response in June (with strong convection) in Pearl River Delta region for 2008-2012 at cloud-resolving scale using an air quality-climate coupled model. Aerosols suppress deep convection by increasing atmospheric stability leading to less evaporation from the ground. The relative humidity is reduced in middle-upper troposphere due to induced reduction in both evaporation from the ground and upward motion. The cloud reduction offsets 20% of the aerosol DRF. The weaker vertical mixing further increases surface aerosol concentration by up to 2.90 μg/m3. These findings indicate the aerosol DRF impact on deep convection and in turn regional air quality.

A Novel Selective Deep Eutectic Solvent Extraction Method for Versatile Determination of Copper in Sediment Samples by ICP-OES.

PubMed

Bağda, Esra; Altundağ, Huseyin; Tüzen, Mustafa; Soylak, Mustafa

2017-08-01

In the present study, a simple, mono step deep eutectic solvent (DES) extraction was developed for selective extraction of copper from sediment samples. The optimization of all experimental parameters, e.g. DES type, sample/DES ratio, contact time and temperature were performed with using BCR-280 R (lake sediment certified reference material). The limit of detection (LOD) and the limit of quantification (LOQ) were found as 1.2 and 3.97 µg L -1 , respectively. The RSD of the procedure was 7.5%. The proposed extraction method was applied to river and lake sediments sampled from Serpincik, Çeltek, Kızılırmak (Fadl and Tecer region of the river), Sivas-Turkey.

POPO AGIE PRIMITIVE AREA, WYOMING.

USGS Publications Warehouse

Pearson, Robert C.; Patten, L.L.

1984-01-01

A mineral-resource appraisal was made of the Popo Agie Primitive Area and some adjoining lands. This scenic mountainous region of the Wind River Range in west-central Wyoming is composed largely of ancient granitic rocks in which virtually no evidence of mineral deposits was found. Deep crustal seismic-reflection profiles obtained across the southern Wind River Range suggest the possibility that young sedimentary rocks, similar to those at the surface along the northeast flank of the range, are present at depth beneath the granite in the Popo Agie primitive Area. If present, such buried sedimentary rocks could be petroleum bearing. Additional seismic and gravity studies would probably add valuable information, but ultimately very expensive, very deep drilling will be necessary to test this possibility.

Importance of Oceanian small mountainous rivers (SMRs) in global land-to-ocean output of lignin and modern biospheric carbon

PubMed Central

Bao, Hongyan; Lee, Tsung-Yu; Huang, Jr-Chuan; Feng, Xiaojuan; Dai, Minhan; Kao, Shuh-Ji

2015-01-01

The land-to-ocean export of particulate organic carbon (POC) connects carbon flow from the atmosphere through land to the ocean, of which the contemporary fraction that reaches the deep sea for burial may effectively affect atmospheric CO2. In this regard, small mountainous rivers (SMRs) in Oceania, a global erosion hotspot driven by torrential typhoon rain and active earthquakes are potentially important. Here we measured typhoon lignin discharges for Taiwan SMRs. We found that the particulate lignin export in 96 hours by a single SMR amounting to ~20% of the annual export by Mississippi River. The yearly particulate lignin discharge from Taiwan Island (35,980 km2) is governed by the frequency and magnitude of typhoon; thus, the historical lignin export ranged widely from 1.5 to 99.7 Gg yr−1, which resulted in a 10–100 times higher areal yield relative to non-Oceanian rivers. The lignin-derived modern POC output from Oceania region is 37 ± 21 Tg C yr−1, account for approximately 20% of the annual modern POC export from global rivers. Coupled with the hyperpycnal pathway, the forested watersheds of SMRs in Oceania may serve as a giant factory to rapidly produce and efficiently convey modern POC into deep sea for sequestration. PMID:26584586

Geologic map of the Cape Disappointment-Naselle River area, Pacific and Wahkiakum counties, Washington

USGS Publications Warehouse

Wells, R.E.

1989-01-01

The Cape Disappointment-Naselle River area is in southwestern Washington at the mouth of the Columbia River.  The area encompasses several major estuaries and their adjacent highlands, which reach elevations of about 2,000 feet.  Rainfall is abundant and produces heavy vegetation and deep weathering of the bedrock.  Natural bedrock exposures are restricted to stream courses along larger drainages, although a network of logging roads provides excellent access to most of the area and widespread, but somewhat ephemeral, exposures of bedrock.

Hydrocarbon Source Rocks in the Deep River and Dan River Triassic Basins, North Carolina

USGS Publications Warehouse

Reid, Jeffrey C.; Milici, Robert C.

2008-01-01

This report presents an interpretation of the hydrocarbon source rock potential of the Triassic sedimentary rocks of the Deep River and Dan River basins, North Carolina, based on previously unpublished organic geochemistry data. The organic geochemical data, 87 samples from 28 drill holes, are from the Sanford sub-basin (Cumnock Formation) of the Deep River basin, and from the Dan River basin (Cow Branch Formation). The available organic geochemical data are biased, however, because many of the samples collected for analyses by industry were from drill holes that contained intrusive diabase dikes, sills, and sheets of early Mesozoic age. These intrusive rocks heated and metamorphosed the surrounding sediments and organic matter in the black shale and coal bed source rocks and, thus, masked the source rock potential that they would have had in an unaltered state. In places, heat from the intrusives generated over-mature vitrinite reflectance (%Ro) profiles and metamorphosed the coals to semi-anthracite, anthracite, and coke. The maximum burial depth of these coal beds is unknown, and depth of burial may also have contributed to elevated thermal maturation profiles. The organic geochemistry data show that potential source rocks exist in the Sanford sub-basin and Dan River basin and that the sediments are gas prone rather than oil prone, although both types of hydrocarbons were generated. Total organic carbon (TOC) data for 56 of the samples are greater than the conservative 1.4% TOC threshold necessary for hydrocarbon expulsion. Both the Cow Branch Formation (Dan River basin) and the Cumnock Formation (Deep River basin, Sanford sub-basin) contain potential source rocks for oil, but they are more likely to have yielded natural gas. The organic material in these formations was derived primarily from terrestrial Type III woody (coaly) material and secondarily from lacustrine Type I (algal) material. Both the thermal alteration index (TAI) and vitrinite reflectance data (%Ro) indicate levels of thermal maturity suitable for generation of hydrocarbons. The genetic potential of the source rocks in these Triassic basins is moderate to high and many source rock sections have at least some potential for hydrocarbon generation. Some data for the Cumnock Formation indicate a considerably higher source rock potential than the basin average, with S1 + S2 data in the mid-20 mg HC/g sample range, and some hydrocarbons have been generated. This implies that the genetic potential for all of these strata may have been higher prior to the igneous activity. However, the intergranular porosity and permeability of the Triassic strata are low, which makes fractured reservoirs more attractive as drilling targets. In some places, gravity and magnetic surveys that are used to locate buried intrusive rock may identify local thermal sources that have facilitated gas generation. Alternatively, awareness of the distribution of large intrusive igneous bodies at depth may direct exploration into other areas, where thermal maturation is less than the limits of hydrocarbon destruction. Areas prospective for natural gas also contain large surficial clay resources and any gas discovered could be used as fuel for local industries that produce clay products (principally brick), as well as fuel for other local industries.

Quantifying shallow and deep groundwater inputs to rivers with groundwater dating in hydrological observatories.

NASA Astrophysics Data System (ADS)

Aquilina, Luc; Marçais, Jean; Gauvain, Alexandre; Kolbe, Tamara; de Dreuzy, Jean-Raynald; Labasque, Thierry; Abbott, Benjamin W.; Vergnaud, Virginie; Chatton, Eliot; Thomas, Zahra; Ruiz, Laurent; Bour, Olivier; Pinay, Gilles

2017-04-01

River water derives in part from groundwater—water that has spent some time in the subsurface (e.g. soil, unsaturated zone, saturated zone). However, because groundwater residence times vary from months to millennia, determining the proportion of shallow and deep groundwater contribution can be challenging. Groundwater dating with anthropogenic gases and natural geochemical tracers can decipher the origin of groundwater contribution to rivers, particularly when repeat samplings are carried out in different hydrological conditions. Here, we present two different applications of this approach from three hydrological observatories (H+ hydrogeological network; Aghrys and Armorique observatories) in western France, all these observatories belonging to the OZCAR national network. We carried out a regional investigation of mean groundwater ages in hard rock aquifers in Brittany, using long-term chronicles from hydrological observatories and regional monitoring sites. We determined the mean residence-time (RT) and annual renewal rate (RR) of four compartments of these aquifers: the direct contribution of a very young water component (i.e. RT less than 1-2 yr), the upper variably saturated zone (RR 27-33%), the weathered layer (RR 1.8-2.1%) and the fractured zone (RR 0.1%). From these values and a nitrate chronicle, we were able to determine the respective contributions of each compartment to the largest river in Brittany, the Vilaine, which drains 30% of the region. We found that the deep fractured compartment with very slow renewal times contributed to 25-45% of river water in winter and 30-60% in summer. The very young water which includes direct precipitation and soil fluxes constituted 40-65% of the winter river water (Aquilina et al., 2012). To complement these estimates, we investigated the relationship between dissolved silica and groundwater age in the Armorique hydrological observatory in northern Brittany. We computed the silica concentration expected along the river from the groundwater age deduced from a deterministic model of the aquifer (Kolbe et al., 2016). The relationship between silica concentration determined with anthropogenic gases and observed silica concentration was strong (R2= 0.54-0.92), indicating that silica was a reliable geochemical chronometer, though it systematically underestimated anthropogenic gas age estimates. The difference could be accounted for by the very young water contribution : approximately 20 - 40% of overall discharge. Both approaches indicated that very young water is particularly important during winter and that deep groundwater contributes at least a third of the river discharge throughout the year. This last result has implications for river nitrate dynamics and understanding the potential limits of catchment management interventions which only reduce nitrate dynamics in shallow groundwater on decadal timescales. Aquilina L. et al., 2012 - Nitrate dynamics in agricultural catchments deduced from groundwater dating and long-term nitrate monitoring in surface- and groundwaters. Sci of the total Environment 435, 167-178. Kolbe et al., 2016 - Coupling 3D groundwater modeling with CFC-based age dating to classify local groundwater circulation in an unconfined crystalline aquifer. J. of Hydrology DOI: 10.1016/j.jhydrol.2016.05.020

Geochemical effects of deep-well injection of the Paradox Valley brine into Paleozoic carbonate rocks, Colorado, U.S.A.

USGS Publications Warehouse

Rosenbauer, R.J.; Bischoff, J.L.; Kharaka, Y.K.

1992-01-01

Brine seepage into the Dolores River from ground water in Paradox Valley, Colorado constitutes a major source of salt to the Colorado River. Plants are enderway to remove this source of salt by drawing down the Paradox Valley brine (PVB) and forcibly injecting it into a deep disposal well (4.8 km). Experiments were conducted to determine the effects of deep-well injection of PVB. The results show that PVB is near saturation with anhydrite at 25??C, and that heating results in anhydrite precipitation. The amount and the rate at which anhydrite forms is temperature, pressure, and substrate dependent. Paradox Valley brine heated in the presence of Precambrian rocks from the drill core produces the same amount of anhydrite as PVB heated alone, but at a greatly accelerated rate. A 30% dilution of PVB with Dolores River water completely eliminates anhydrite precipitation when the fluid is heated with the Precambrian rocks. Interaction of PVB and Leadville Limestone is characterized by dolomitization of calcite by brine Mg which releases Ca to solution. This added Ca reacts with SO4 to form increased amounts of anhydrite. A 20% dilution of PVB by Dolores River water has no effect on dolomitization and reduces the amount of anhydrite only slightly. A 65% dilution of PVB by Dolores River water still does not prevent dolomitization but does suppress anhydrite formation. Computer modeling of PVB by programs utilizing the Pitzer ion-interaction parameters is in general agreement with the experimental results. Ion-activity products calculated by both SOLMINEQ and PHRQPITZ are close to equilibrium with both anhydrite and dolomite whenever these phases are present experimentally, although the calculations over-estimate by a factor of 2 the degree of saturation. Some discrepancies in the calculated results between the two programs are due largely to differences in mineral solubility data. ?? 1992.

Pollutants' Release, Redistribution and Remediation of Black Smelly River Sediment Based on Re-Suspension and Deep Aeration of Sediment.

PubMed

Zhu, Lin; Li, Xun; Zhang, Chen; Duan, Zengqiang

2017-04-01

Heavily polluted sediment is becoming an important part of water pollution, and this situation is particularly acute in developing countries. Sediment has gradually changed from being the pollution adsorbent to the release source and has influenced the water environment and public health. In this study, we evaluated the pollutant distribution in sediment in a heavily polluted river and agitated the sediment in a heavily polluted river to re-suspend it and re-release pollutants. We found that the levels of chemical oxygen demand (COD), NH₄⁺-N, total nitrogen (TN), and total phosphorus (TP) in overlying water were significantly increased 60 min after agitation. The distribution of the pollutants in the sediment present high concentrations of pollutants congregated on top of the sediment after re-settling, and their distribution decreased with depth. Before agitation, the pollutants were randomly distributed throughout the sediment. Secondly, deep sediment aeration equipment (a micro-porous air diffuser) was installed during the process of sedimentation to study the remediation of the sediment by continuous aeration. The results revealed that deep sediment aeration after re-suspension significantly promoted the degradation of the pollutants both in overlying water and sediment, which also reduced the thickness of the sediment from 0.9 m to 0.6 m. Therefore, sediment aeration after suspension was efficient, and is a promising method for sediment remediation applications.

Changes in the channel-bed level of the western Carpathian rivers over the last 40years

NASA Astrophysics Data System (ADS)

Kijowska-Strugała, Małgorzata; Bucała-Hrabia, Anna

2017-04-01

Channel-bed level is constantly changing in time and space, and the process is dependent on both natural and anthropogenic factors. In mountain areas this is one of the more visible morphological processes. The main aim of the research was to analyze the dynamics of the position of river channel beds. Three rivers located within the western part of Polish Carpathians were chosen for the analysis: the Ropa river, the Kamienica Nawojowska river and the Ochotnica river. They are typical rivers for the Beskidy Mountains, medium Flysch mountains. To assess changes in the position of channel bed long-term series of data of minimum water stages in the river were used. The Ropa river is the biggest left tributary of the Wisłoka river (basin a of the upper Vistula River). The total length of the river amounts to 80 km, its gradient equals 58.9‰ and the water basin area amounts to 974 km2. The Kamienica Nawojowska river, with a length of 32.2 km is a right tributary of Dunajec river. The average decrease for the entire watercourse is 18.1‰. The catchment area is 238 km2. The Ochotnica river is 22.7 km long and it is a left tributary of the Dunajec river. The average slope for the entire watercourse is 36.1‰. The Ochotnica river characterized by deep valleys (catchment area 107.6 km2). Analysis of trends in minimum annual water stages in the alluvial Ropa river channel throughout the multi-year period of 1995-2014 shows an increasing trend amounting to 0.8 cm/year. In the Kamienica Nawojowska river the tendency of incision was observed starting from the 1960 to 2014. Average annual rate of increase of the minimum stages was between 0.4 to 1.2 cm/year. On the basis of the analysis of the minimum water levels in the years 1972-2011 two periods can be seen with different tendencies to change the position of the Ochotnica channel bottom. The first covers the years 1972-1996, where aggradation (3.9 cm/year) was the predominant process while in the period 1997-2011 incision (3.2 cm/year) was dominated. Two main factors determine changes in the position of the rivers channel beds: natural (floods, tributaries, type of the channel bed substrate) and anthropogenic (control works in the channel, extraction gravels, reservoir backwater. The deep erosion observed in the Carpathians rivers in the last decade is also associated with changes in land use that have increased due to the economic transformation of the country, and in recent years, the Polish accession to the EU.

Cool Water Formation and Trout Habitat Use in a Deep Pool in the Sierra Nevada, California

Treesearch

KATHLEEN R. MATTHEWS; NEIL H. BERG; AZUMA DAVID L.

1994-01-01

We documented temperature stratification in a deep bedrock pool in the North Fork of the American River, described the diel movement of rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta. and determined whether these trout used cooler portions of the pool.From July 30 to October 10, 1992, the main study pool and an adjacent pool were stratified(temperature...

Rapid climatic signal propagation from source to sink in a southern California sediment-routing system

USGS Publications Warehouse

Covault, J.A.; Romans, B.W.; Fildani, A.; McGann, M.; Graham, S.A.

2010-01-01

Terrestrial source areas are linked to deep-sea basins by sediment-routing systems, which only recently have been studied with a holistic approach focused on terrestrial and submarine components and their interactions. Here we compare an extensive piston-core and radiocarbon-age data set from offshore southern California to contemporaneous Holocene climate proxies in order to test the hypothesis that climatic signals are rapidly propagated from source to sink in a spatially restricted sediment-routing system that includes the Santa Ana River drainage basin and the Newport deep-sea depositional system. Sediment cores demonstrate that variability in rates of Holocene deep-sea turbidite deposition is related to complex ocean-atmosphere interactions, including enhanced magnitude and frequency of the North American monsoon and El Ni??o-Southern Oscillation cycles, which increased precipitation and fluvial discharge in southern California. This relationship is evident because, unlike many sediment-routing systems, the Newport submarine canyon-and-channel system was consistently linked tothe Santa Ana River,which maintained sediment delivery even during Holocene marine transgression and highstand. Results of this study demonstrate the efficiency of sediment transport and delivery through a spatially restricted, consistently linked routing system and the potential utility of deep-sea turbidite depositional trends as paleoclimate proxies in such settings. ?? 2010 by The University of Chicago.

Hugli River Delta, India

NASA Image and Video Library

2001-10-22

The western-most part of the Ganges Delta is seen in this 54.5 by 60 km ASTER sub-scene acquired on January 6, 2005. The Hugli River branches off from the Ganges River 300 km to the north, and flows by the city of Calcutta before emptying into the Bay of Bengal. High sediment load is evident by the light tan colors in the water, particularly downstream from off-shore islands. The deep green colors of some of these islands are mangrove swamps. The image is centered at 21.9 degrees north latitude, 88 degrees east longitude. http://photojournal.jpl.nasa.gov/catalog/PIA11158

40 CFR 81.183 - Eastern Connecticut Intrastate Air Quality Control Region.

Code of Federal Regulations, 2010 CFR

2010-07-01

... within the outermost boundaries of the area so delimited): In the State of Connecticut: Towns—Ashford, Bozrah, Brooklyn, Canterbury, Chaplin, Chester, Clinton, Colchester, Columbia, Coventry, Deep River...

Characterization of the 3-Dimensional Mississippi River Plume Using a High Resolution Circulation Model Coupled with Ocean Color Imagery and Field Data

NASA Astrophysics Data System (ADS)

Soto Ramos, I. M.; Arnone, R.; Cambazoglu, M. K.; Jacobs, G. A.; Vandermeulen, R. A.; Howden, S. D.

2016-02-01

The Mississippi River Plume (MRP) is responsible for creating a highly dynamic environment in the northern Gulf of Mexico (nGoM). It is also responsible for the transport of rich-nutrient waters, physical and biological connectivity between the nGoM coastal waters to the deep ocean and other regions within the Gulf, and in cases of unfortunate events such as the Deep Horizon Oil Spill it may contribute to the transport and fate of hydrocarbons. The main objective of this work is to characterize the 3-Dimensional MRP using modeled salinity data from the 1 km resolution Navy Coastal Ocean Model (NCOM) and ocean color data (e.g., Chlorophyll-a) from the Visible Infrared Imaging Radiometer Suite (VIIRS). Field data from ships and gliders were used to validate the model and satellite data. An initial step for this study was to determine how to define a "river plume". We selected several study cases of 7 to 10 days in which the river plume was visible in the satellite imagery and examined the vertical salinity distribution at selected cross sections along the river plume. Different salinity thresholds were used to define a river plume and characterize the 3-D dilution and dispersion of the MRP during the study cases. The surface response as means of chlorophyll and light availability in relationship to the depth of the river plume was investigated. Our results improved understanding of the formation of the mixed layer depth in the MRP and how we can integrate model and satellite data to delineate the 3D structure of the river plume and better understand the biological surface response observed in the satellite imagery. The output of this study highlights how circulation models and satellite data can be integrated to better understand the connectivity, transport and fate of sediments, nutrients, and pollutants in the Gulf of Mexico.

Determination of ten perfluorinated compounds in bluegill sunfish (Lepomis macrochirus) fillets

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

Delinsky, Amy D.; Strynar, Mark J.; Nakayama, Shoji F.

2009-11-15

A rigorous solid phase extraction/liquid chromatography/tandem mass spectrometry method for the measurement of 10 perfluorinated compounds (PFCs) in fish fillets is described and applied to fillets of bluegill sunfish (Lepomis macrochirus) collected from selected areas of Minnesota and North Carolina. The 4 PFC analytes routinely detected in bluegill fillets were perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (C10), perfluoroundecanoic acid (C11), and perflurododecanoic acid (C12). Measures of method accuracy and precision for these compounds showed that calculated concentrations of PFCs in spiked samples differed by less than 20% from their theoretical values and that the %RSD for repeated measurements was less thanmore » 20%. Minnesota samples were collected from areas of the Mississippi River near historical PFC sources, from the St. Croix River as a background site, and from Lake Calhoun, which has no documented PFC sources. PFOS was the most prevalent PFC found in the Minnesota samples, with median concentrations of 47.0-102 ng/g at locations along the Mississippi River, 2.08 ng/g in the St. Croix River, and 275 ng/g in Lake Calhoun. North Carolina samples were collected from two rivers with no known historical PFC sources. PFOS was the predominant analyte in fish taken from the Haw and Deep Rivers, with median concentrations of 30.3 and 62.2 ng/g, respectively. Concentrations of C10, C11, and C12 in NC samples were among the highest reported in the literature, with respective median values of 9.08, 23.9, and 6.60 ng/g in fish from the Haw River and 2.90, 9.15, and 3.46 ng/g in fish from the Deep River. These results suggest that PFC contamination in freshwater fish may not be limited to areas with known historical PFC inputs.« less

Determination of flow losses in the Cape Fear River between B. Everett Jordan Lake and Lillington, North Carolina, 2008-2010

USGS Publications Warehouse

Weaver, J. Curtis; McSwain, Kristen Bukowski

2013-01-01

During 2008-2010, the U.S. Geological Survey conducted a hydrologic investigation in cooperation with the Triangle J Council of Governments Cape Fear River Flow Study Committee and the North Carolina Division of Water Resources to collect hydrologic data in the Cape Fear River between B. Everett Jordan Lake and Lillington in central North Carolina to help determine if suspected flow losses occur in the reach. Flow loss analyses were completed by summing the daily flow releases at Jordan Lake Dam with the daily discharges at Deep River at Moncure and Buckhorn Creek near Corinth, then subtracting these values from the daily discharges at Cape Fear River at Lillington. Examination of long-term records revealed that during 10,227 days of the 1983-2010 water years, 408 days (4.0 percent) had flow loss when conditions were relatively steady with respect to the previous day's records. The flow loss that occurred on these 40 days ranged from 0.49 to 2,150 cubic feet per second with a median flow loss of 37.2 cubic feet per second. The months with the highest number of days with flow losses were June (16. percent), September (16.9 percent), and October (19.4 percent). A series of synoptic discharge measurements made on six separate days in 2009 provided "snapshots" of overall flow conditions along the study reach. The largest water diversion is just downstream from the confluence of the Haw and Deep Rivers, and discharges substantially decrease in the main stem downstream from the intake point. Downstream from Buckhorn Dam, minimal gain or loss between the dam and Raven Rock State Park was noted. Analyses of discharge measurements and ratings for two streamgages-one at Deep River at Moncure and the other at Cape Fear River at Lillington-were completed to address the accuracy of the relation between stage and discharge at these sites. The ratings analyses did not indicate a particular time during the 1982-2011 water years in which a consistent bias occurred in the computations of discharge records that would indicate false flow losses. A total of 34 measured discharges at a streamgage on the Haw River below B. Everett Jordan Lake near Moncure were compared with the reported hourly flow releases from Jordan Lake Dam. Because 28 of 34 measurements were within plus or minus 10 percent of the hourly flow releases reported by the U.S Army Corps of Engineers, use of the current discharge computation tables for reporting Jordan Lake Dam flow releases is generally supported. A stage gage was operated on the Cape Fear River at Buckhorn Dam near Corinth to collect continuous stage-only records. Throughout the study period, flow over the dam was observed along its length, and flow loss within the study reach is not attributed to river-level fluctuations at the dam. Water-use information and (or) data were obtained for five industrial facilities, a regional power utility, two municipalities, one small hydropower facility on the Deep River, and one quarry operation also adjacent to the Deep River. The largest water users are the regional power producer, a small hydropower operation, and the two municipalities. The total water-use diversions for these facilities range from almost 25.5 to 38.5 cubic feet per second (39.5 to 59.5 million gallons per day) during the winter and summer periods, respectively. This range is equivalent to 69 to 104 percent of the 37 cubic feet per second median flow loss. The Lockville hydropower station is on the Deep River about 1 mile downstream from the streamgage near Moncure. Run-of-river operations at the facility do not appear to affect flow losses in the study reach. The largest water user in the study area is a regional power producer at a coal-fired power-generation plant located immediately adjacent to the Cape Fear River just downstream from the confluence of the Haw an Deep Rivers. Comparisons of daily water withdrawals, sup-plied by the regional power producer, and discharge records at a streamgage on the diversion canal indicated many days when consumption exceeded the producer's estimates for the cooling towers. Uncertainty surrounding reasonable estimates of consumption remained in effect at the end of the study. Data concerning evaporative losses were compiled using two approaches-an analysis of available pan-evaporation data from a National Weather Service cooperative observer station in Chapel Hill, North Carolina; and a compilation of reference open-water evaporation computed by the State Climate Office of North Carolina. The potential flow loss by evaporation from the main stem and the Deep River was estimated to be in the range of 4 to 14 cubic feet per second during May through October, equivalent to 10 to 38 percent of the 37 cubic feet per second median flow loss. Daily water-use diversions and evaporation losses were compared to flow-loss occurrences during the period April 2008 through September 2010. In comparing the surface-water, water-use, and evaporation data compiled for 2008-2010, it is evident that documented water diversions combined with flow losses by open-water evaporation can exceed the net flow gain in the study area and result in flow losses from the reach. Analysis of data from a streamgage downstream from the regional power plant on the diversion canal adjacent to the Cape Fear River provided insight into the occurrence of an apparent flow loss at the streamgage at Lillington. Assessment of the daily discharges and subsequent hydrographs for the canal streamgage indicated at least 24 instances during the study when the flows suddenly changed by magnitudes of 100 to more that 200 cubic feet per second, resulting in a noted time-lag effect on the downstream discharges at the Lillington streamgage, beginning 8 to 16 hours after the sudden flow change. A fiber-optic distributed temperature-sensing survey was conducted on the Cape Fear River at the Raven Rock State Park reach August 12-14, 2009, to determine if the presence of diabase dikes were preferentially directing groundwater discharge. No temperature anomalies of colder water were measured during the survey, which indicated that at the time of the survey that particular reach of the Cape Fear River was a "no-flow" or losing stream. An aerial thermal-infrared survey was conducted on the Haw and Cape Fear Rivers on February 27, 2010, from Jordan Lake Dam to Lillington to qualitatively delineate areas of groundwater discharge on the basis of the contrast between warm groundwater discharge and cold surface-water temperatures. Dis-charge generally was noted as diffuse seepage, but in a few cases springs were detected as inflow at a discrete point of discharge. Two reaches of the Cape Fear River (regional power plant and Bradley Road reaches) were selected for groundwater monitoring with a transect of piezometers installed within the flood plain. Groundwater-level altitudes at these reaches were analyzed for 1 water year (October 1, 2009, to September 30, 2010). Data collected as part of this study represent only a brief period of time and may not represent all conditions and all years; however, the data indicate that, during the dry summer months, the Cape Fear River within the study area is losing an undetermined quantity of water through seepage. Analyses completed during this investigation indicate a study reach with complex flow patterns affected by numerous concurrent factors resulting in flow losses. The causes of flow loss could not be solely attributed to any one factor. Among the factors considered, the occurrences of water diversions and evaporative losses were determined to be sufficient on some days (particularly during the base-flow period) to exceed the net gain in flows between the upstream and downstream ends of the study area. Losses by diversions and evaporation can exceed the median flow loss of 3 cubic feet per second, which indicates that flow loss from the study reach is real. Groundwater data collected during 2009-2010 indicate the possibility of localized flow loss during the summer, particularly in the impounded reach above Buckhorn Dam. However, no indication of unusual patterns was noted that would cause substantial flow loss by groundwater and surface-water interaction at the river bottom.

Arsenic pollution of groundwater in Vietnam exacerbated by deep aquifer exploitation for more than a century

PubMed Central

Winkel, Lenny H. E.; Trang, Pham Thi Kim; Lan, Vi Mai; Stengel, Caroline; Amini, Manouchehr; Ha, Nguyen Thi; Viet, Pham Hung; Berg, Michael

2011-01-01

Arsenic contamination of shallow groundwater is among the biggest health threats in the developing world. Targeting uncontaminated deep aquifers is a popular mitigation option although its long-term impact remains unknown. Here we present the alarming results of a large-scale groundwater survey covering the entire Red River Delta and a unique probability model based on three-dimensional Quaternary geology. Our unprecedented dataset reveals that ∼7 million delta inhabitants use groundwater contaminated with toxic elements, including manganese, selenium, and barium. Depth-resolved probabilities and arsenic concentrations indicate drawdown of arsenic-enriched waters from Holocene aquifers to naturally uncontaminated Pleistocene aquifers as a result of > 100 years of groundwater abstraction. Vertical arsenic migration induced by large-scale pumping from deep aquifers has been discussed to occur elsewhere, but has never been shown to occur at the scale seen here. The present situation in the Red River Delta is a warning for other As-affected regions where groundwater is extensively pumped from uncontaminated aquifers underlying high arsenic aquifers or zones. PMID:21245347

Alaska Glaciers and Rivers

NASA Technical Reports Server (NTRS)

2007-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image on October 7, 2007, showing the Alaska Mountains of south-central Alaska already coated with snow. Purple shadows hang in the lee of the peaks, giving the snow-clad land a crumpled appearance. White gives way to brown on the right side of the image where the mountains yield to the lower-elevation Susitna River Valley. The river itself cuts a silver, winding path through deep green forests and brown wetlands and tundra. Extending from the river valley, are smaller rivers that originated in the Alaska Mountains. The source of these rivers is evident in the image. Smooth white tongues of ice extend into the river valleys, the remnants of the glaciers that carved the valleys into the land. Most of the water flowing into the Gulf of Alaska from the Susitna River comes from these mountain glaciers. Glacier melt also feeds glacier lakes, only one of which is large enough to be visible in this image. Immediately left of the Kahiltna River, the aquamarine waters of Chelatna Lake stand out starkly against the brown and white landscape.

Mechanical-mathematical modeling for landslide process

NASA Astrophysics Data System (ADS)

Svalova, V.

2009-04-01

Landslides process is one of the most widespread and dangerous processes in the urbanized territories. In Moscow the landslips occupy about 3 % of the most valuable territory of city. There are near 20 places of deep landslides and some hundreds of shallow landslides in Moscow. In Russia many towns are located near rivers on high coastal sides. There are many churches and historical buildings on high costs of Volga River and Moscow River. The organization of monitoring is necessary for maintenance of normal functioning of city infrastructure in a coastal zone and duly realization of effective protective actions. Last years the landslide process activization took place in Moscow. The right coast of river Moscow on its significant extent within the limits of city Moscow is struck by deep block landslides with depth up to 90 - 100 m which formation occurred in preglacial time with basis of sliding in Callovian-Oxford clays of Jurassic system on 25 - 30 m below modern level of the river . One of landslide sites is on Vorob'evy mountains, on a high slope of the right coast of the river Moscow with height of 65 m. There is a historical monument - «Andreevsky monastery», based in 1648. Also there are the complex of buildings of Presidium of the Russian Academy of Sciences, constructed in 70 - 80th years of 20-th century, bridge with station of underground "Vorob'evy mountain", constructions of sport complexes. Landslide slope is in active condition, and there are many attributes of activization of deep block landslide. In June 2007 a rather big landslide took place there near ski-jump. Another landslide site is in a southeast part of Moscow, occupying the right coast of river Moscow near museum - reserve "Kolomenskoye". The slope in this place has height of 38 - 40 m. Motions of deep landslips have begun from 1960 in connection with construction of collectors. In 70th years of XX century there was a strong activization of a slope with formation of cracks by extent up to 500 m and displacement of a landslide in the plan over 1 m. Last serious activization of a landslide has taken place in 2002 with a motion on 53 cm. Catastrophic activization of the deep blockglide landslide in the area of Khoroshevo in Moscow took place in 2006-2007. A crack of 330 m long appeared in the old sliding circus, along which a new 220 m long creeping block was separated from the plateau and began sinking with a displaced surface of the plateau reaching to 12 m. Such activization of the landslide process was not observed in Moscow since mid XIX century. The sliding area of Khoroshevo was stable during long time without manifestations of activity. Revealing of the reasons of deformation and development of ways of protection from deep landslide motions is extremely actual and difficult problem which decision is necessary for preservation of valuable historical monuments and modern city constructions. The reasons of activization and protective measures are discussed. Structure of monitoring system for urban territories is elaborated. Mechanical-mathematical model of high viscous fluid was used for modeling of matter behavior on landslide slopes. Equation of continuity and an approximated equation of the Navier-Stockes for slow motions in a thin layer were used. The results of modelling give possibility to define the place of highest velocity on landslide surface, which could be the best place for monitoring post position. Model can be used for calibration of monitoring equipment and gives possibility to investigate some fundamental aspects of matter movement on landslide slope.

Upper Cretaceous Shannon Sandstone reservoirs, Powder River Basin, Wyoming: evidence for organic acid diagenesis?

USGS Publications Warehouse

Hansley, P.L.; Nuccio, V.F.

1992-01-01

Comparison of the petrology of shallow and deep oil reservoirs in the Upper Cretaceous Shannon Sandstone Beds of the Steele Member of the Cody Shale strongly suggests that organic acids have had a more significant impact on the diagenetic alteration of aluminosilicate grains and carbonate cements in the deep reservoirs than in the shallow reservoirs. Vitrinite reflectance and Rock-Eval measurements, as well as the time-temperature index and kinetic modeling, indicate that deep reservoirs have been subjected to maximum temperatures of approximately 110-120??C, whereas shallow reservoirs have reached only 75??C. -from Authors

Enhanced Geothermal System Potential for Sites on the Eastern Snake River Plain, Idaho

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

Robert K Podgorney; Thomas R. Wood; Travis L McLing

2013-09-01

The Snake River volcanic province overlies a thermal anomaly that extends deep into the mantle and represents one of the highest heat flow provinces in North America (Blackwell and Richards, 2004). This makes the Snake River Plain (SRP) one of the most under-developed and potentially highest producing geothermal districts in the United States. Elevated heat flow is typically highest along the margins of the topographic SRP and lowest along the axis of the plain, where thermal gradients are suppressed by the Snake River aquifer. Beneath this aquifer, however, thermal gradients rise again and may tap even higher heat flows associatedmore » with the intrusion of mafic magmas into the mid-crustal sill complex (e.g., Blackwell, 1989).« less

Geology of deep-water sandstones in the Mississippi Stanley Shale at Cossatot Falls, Arkansas

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

Coleman, J.L. Jr.

1993-09-01

The Mississippian Stanley Shale crops out along the Cossatot River in the Ouachita Mountains of western Arkansas. Here, exposures of deep-water sandstones and shales, on recently established public lands, present a rare, three-dimensional look at sandstones of the usually obscured Stanley. Cossatot Falls, within the Cossatot River State Park Natural Area, is a series of class IV and V rapids developed on massive- to medium-bedded quartz sandstones on the northern flank of an asymmetric, thrust-faulted anticline. In western Arkansas, the Stanley Shale is a 10,000-ft (3200-m) succession of deep-water sandstone and shale. At Cossatot Falls, approximately 50 ft (155 m)more » of submarine-fan-channel sedimentary rocks are exposed during low-river stages. This section is composed primarily of sets of thinning-upward sandstone beds. With rare exceptions, the sandstones are turbidites, grading from massive, homogeneous, basal beds upward through festoon-cross-bedded thick beds, into rippled medium and thin beds. Sandstone sets are capped by thin shales and siltstones. Regional, north-northwestward paleocurrent indicators are substantiated by abundant, generally east-west ripple crests asymmetric to the north-northwest. Flute casts at the top of the sandstone sequence indicate an additional east-ward flow component. Based on regional, lithologic characteristics, the sandstones at Cossatot Falls appear to be within the Moyers Formation. The Moyers is the upper sandstone unit of the Stanley and is an oil and gas reservoir in the eastern Oklahoma Ouachita Mountains.« less

River-corridor habitat dynamics, Lower Missouri River

USGS Publications Warehouse

Jacobson, Robert B.

2010-01-01

Intensive management of the Missouri River for navigation, flood control, and power generation has resulted in substantial physical changes to the river corridor. Historically, the Missouri River was characterized by a shifting, multithread channel and abundant unvegetated sandbars. The shifting channel provided a wide variety of hydraulic environments and large areas of connected and unconnected off-channel water bodies.Beginning in the early 1800s and continuing to the present, the channel of the Lower Missouri River (downstream from Sioux City, Iowa) has been trained into a fast, deep, single-thread channel to stabilize banks and maintain commercial navigation. Wing dikes now concentrate the flow, and revetments and levees keep the channel in place and disconnect it from the flood plain. In addition, reservoir regulation of the Missouri River upstream of Yankton, South Dakota, has substantially changed the annual hydrograph, sediment loads, temperature regime, and nutrient budgets.While changes to the Missouri River have resulted in broad social and economic benefits, they have also been associated with loss of river-corridor habitats and diminished populations of native fish and wildlife species. Today, Missouri River stakeholders are seeking ways to restore some natural ecosystem benefits of the Lower Missouri River without compromising traditional economic uses of the river and flood plain.

National Dam Inspection Program. Ingham Creek (Aquetong Lake) Dam (NDI ID PA 00224, PA DER 9-49) Delaware River Basin, Ingham Creek, Pennsylvania. Phase I Inspection Report,

DTIC Science & Technology

1981-04-01

Delaware River Basing Ingham Justif icaticn--- L Creek, Pennsylvania. Phase I Inspection Do DEL-AWARE RIVER BASIN Availabilit T Co~es Avail and/or D...about 1.5H:IV and an unknown upstream slope below the water surface. The dam impounds a reservoir with a normal pool surface area of 12.4 acres and a...deep. It was once used to direct water to a mill downstream of the dam and is now in poor condition. The spillway Design Flood (SDF) chosen for this

The Northern end of the Dead Sea Basin: Geometry from reflection seismic evidence

USGS Publications Warehouse

Al-Zoubi, A. S.; Heinrichs, T.; Qabbani, I.; ten Brink, Uri S.

2007-01-01

Recently released reflection seismic lines from the Eastern side of the Jordan River north of the Dead Sea were interpreted by using borehole data and incorporated with the previously published seismic lines of the eastern side of the Jordan River. For the first time, the lines from the eastern side of the Jordan River were combined with the published reflection seismic lines from the western side of the Jordan River. In the complete cross sections, the inner deep basin is strongly asymmetric toward the Jericho Fault supporting the interpretation of this segment of the fault as the long-lived and presently active part of the Dead Sea Transform. There is no indication for a shift of the depocenter toward a hypothetical eastern major fault with time, as recently suggested. Rather, the north-eastern margin of the deep basin takes the form of a large flexure, modestly faulted. In the N-S-section along its depocenter, the floor of the basin at its northern end appears to deepen continuously by roughly 0.5??km over 10??km distance, without evidence of a transverse fault. The asymmetric and gently-dipping shape of the basin can be explained by models in which the basin is located outside the area of overlap between en-echelon strike-slip faults. ?? 2007 Elsevier B.V. All rights reserved.

Quality of ground water in the Payette River basin, Idaho

USGS Publications Warehouse

Parliman, D.J.

1986-01-01

As part of a study to obtain groundwater quality data in areas of Idaho were land- and water-resource development is expected to increase, water quality, geologic, and hydrologic data were collected for 74 wells in the Payette River basin, west-central Idaho, from July to October 1982. Historical (pre-1982) data from 13 wells were compiled with more recent (1982) data to define, on a reconnaissance level, water quality conditions in major aquifers and to identify factors that may have affected groundwater quality. Water from the major aquifers generally contains predominantly calcium, magnesium, and bicarbonate plus carbonate ions. Sodium and bicarbonate or sulfate are the predominant ions in groundwater from 25% of the 1982 samples. Areally, groundwater from the upper Payette River basin has proportionately lower ion concentrations than water from the lower Payette River basin. Water samples from wells < 100 ft deep generally have lower ion concentrations than samples from wells > 100 ft deep. Variations in groundwater quality probably are most affected by differences in aquifer composition and proximity to source(s) of recharge. Groundwater in the study area is generally suitable for most uses. In localized areas, pH and concentrations of hardness, alkalinity, dissolved solids, or dissolved nitrite plus nitrate as nitrogen, sulfate, fluoride, iron, or manganese exceed Federal drinking water limits and may restrict some uses of the water.

Natural and Human Impacts on Recent Development of Asian Large Rivers and Deltas

NASA Astrophysics Data System (ADS)

Liu, P.; Lu, C.

2014-12-01

Most recent data analysis indicates sediment loads in most of Asian large rivers (like, Yellow, Yangtze, Pearl, Chao Phraya, Indus, Krishna, Godavari, etc) have decreased up to 80-90% in the past 60 years. Correspondingly, most of Asian large river deltas are facing severe sediment starving; delta shoreline comparisons indicate that some are under strong coastal erosion. For examples, the Yellow River Delta has been retreating since 1990s when its annual sediment load has kept below 300 million tons. The Yangtze River delta kept growing before Three Gorges Dams was operating, and began to be eroded from the year 2003 to 2009, and then prograded locally due to the Deep Water Navigation Project. The Mekong Delta shoreline has also been dynamically changing with the sediment flux variation, eroding from 1989 to 1996 and prograding from 1996 to 2002. More information is available at http://www.meas.ncsu.edu/sealevel

Reproductive success of the interior least tern (Sterna antillarum) in relation to hydrology on the Lower Mississippi River

USGS Publications Warehouse

Dugger, Katie M.; Ryan, Mark R.; Galat, David L.; Renken, Rochelle B.; Smith, John W

2002-01-01

The annual hydrograph of large rivers, including flood pulses and low-flow periods, is believed to play a primary role in the productivity of biota associated with these ecosystems. We investigated the relationship between river hydrology and Interior least tern (Sterna antillarum) reproductive success on the Lower Mississippi River from April to July 1986-1993. The number of fledglings produced per adult pair was negatively correlated with July mean (r= -0.95, p = 0.0004) and July maximum river elevation (r= -0.97, p = 0.0001), but no other aspect of river hydrology were related to tern reproduction. Low-water elevations in July may benefit least tern reproductive success by increasing sand island area or the area of shallow-water habitat that surrounds islands. Loss of deep-water habitats in conjunction with an increase in shallow habitat during stage decreases may concentrate fish prey in shallow-water habitats and backwater areas, thereby increasing food availability during chick-rearing. Copyright ?? 2002 John Wiley & Sons, Ltd.

Estimating the Effects of Conversion of Agricultural Land to Urban Land on Deep Percolation of Irrigation Water in the Grand Valley, Western Colorado

USGS Publications Warehouse

Mayo, John W.

2008-01-01

The conversion of agricultural land to urban residential land is associated with rapid population growth in the Grand Valley of western Colorado. Information regarding the effects of this land-use conversion on deep percolation, irrigation-water application, and associated salt loading to the Colorado River is needed to support water-resource planning and conservation efforts. The Natural Resources Conservation Service (NRCS) assessed deep percolation and estimated salt loading derived from irrigated agricultural lands in the Grand Valley in a 1985 to 2002 monitoring and evaluation study (NRCS M&E). The U.S. Geological Survey (USGS), in cooperation with the Colorado River Salinity Control Forum and the Mesa Conservation District, quantified the current (2005-2006) deep percolation and irrigation-water application characteristics of 1/4-acre residential lots and 5-acre estates, urban parks, and urban orchard grass fields in the Grand Valley, and compared the results to NRCS M&E results from alfalfa-crop sites. In addition, pond seepage from three irrigation-water holding ponds was estimated. Salt loading was estimated for the urban study results and the NRCS M&E results by using standard salt-loading factors. A daily soil-moisture balance calculation technique was used at all urban study irrigated sites. Deep percolation was defined as any water infiltrating below the top 12 inches of soil. Deep percolation occurred when the soil-moisture balance in the first 12 inches of soil exceeded the field capacity for the soil type at each site. Results were reported separately for urban study bluegrass-only sites and for all-vegetation type (bluegrass, native plants, and orchard grass) sites. Deep percolation and irrigation-water application also were estimated for a complete irrigation season at three subdivisions by using mean site data from each subdivision. It was estimated that for the three subdivisions, 37 percent of the developed acreage was irrigated (the balance being impermeable surfaces).

Palynofacies reveal fresh terrestrial organic matter inputs in the terminal lobes of the Congo deep-sea fan

NASA Astrophysics Data System (ADS)

Schnyder, Johann; Stetten, Elsa; Baudin, François; Pruski, Audrey M.; Martinez, Philippe

2017-08-01

The Congo deep-sea fan is directly connected to the Congo River by a unique submarine canyon. The Congo River delivers up to 2×1012gPOC/yr, a part of which is funnelled by the submarine canyon and feeds the deep-sea environments. The more distal part of the Congo deep-sea fan, the terminal lobe area, has a surface of 2500 km2 and is situated up to 800 km offshore at depths of 4750-5000 m. It is a remarkable place to study the fate and distribution of the organic matter transferred from the continent to the deep ocean via turbidity currents. Forty-two samples were analyzed from the terminal lobes, including sites from the active channel, one of its levees and an abandoned distal channel. Samples were collected using multitube cores and push-cores using a Victor 6000 ROV, which surveyed the dense chemosynthetic habitats that locally characterize the terminal lobes. Palynofacies reveal a remarkably well-preserved, dominantly terrestrial particulate organic matter assemblage, that has been transferred from the continent into the deep-sea by turbidity currents. Delicate plant structures, cuticle fragments and plant cellular material is often preserved, highlighting the efficiency of turbidity currents to transfer terrestrial organic matter to the sea-floor, where it is preserved. Moreover, the palynofacies data reveal a general sorting by density or buoyancy of the organic particles, as the turbulent currents escaped the active channel, feeding the levees and the more distal, abandoned channel area. Finally, in addition to aforementioned hydrodynamic factors controlling the organic matter accumulation, a secondary influence of chemosynthetic habitats on organic matter preservation is also apparent. Palynofacies is therefore a useful tool to record the distribution of organic matter in recent and ancient deep-sea fan environments, an important topic for both academic and petroleum studies.

35. FUEL HANDLING BUILDING, INTERIOR LOOKING SOUTHEAST SHOWING TRANSFER CANAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. FUEL HANDLING BUILDING, INTERIOR LOOKING SOUTHEAST SHOWING TRANSFER CANAL AREA, DEEP STORAGE AREA, FUEL STORAGE PIT (LOCATION BB) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

Study on Reventment-Protected and Non-Bottom-Protected Plunge Pool of High Arch Dam

NASA Astrophysics Data System (ADS)

Yingkui, Wang; Quxiu, Cao; Fanhui, Kong

2018-05-01

Lots of high arch dam have the characteristics of “High head, Large discharge and Narrow river valley”, therefore, the security researches of energy dissipation were always the focus in these hydro-projects. Statistically, the trajectory type energy dissipation is the most widely used in the built high arch dams, and the water plunge poor were always set downstream the dam body. However, the widely used protected plunge poor need large investment with the disadvantage of complicated operation and maintenance. Along with the construction of concrete high arch dam in the Southwest China, the river overburden and water cushion were deep in dam site, which is becoming a new characteristic of these hydro-projects. Accordingly, the deep water cushion can be used for the energy dissipation design, such as the “Reventment-Protected and Non-Bottom-Protected Plunge Pool”, which has the advantage of more simplified project design and more economy investment.

Alluvium-Buttressed Landslides: Conceptual Model and Examples from California

NASA Astrophysics Data System (ADS)

Johnson, P. L.; Cotton, W. R., Sr.; Shires, P. O.

2016-12-01

Large, deep-seated landslides typically occur in hillside settings without any natural buttressing, and many of these landslides have relatively low factors of safety (FS), the ratio of driving to resisting forces. However, where deep-seated landslides failed millennia ago into valleys that subsequently experienced alluvial aggradation, a natural buttress of alluvium may be deposited over the landslide toe, increasing the FS of these landslides. The eustatic model for alluvial buttressing of Quaternary landslides involves failure of slopes during sea level low stand at or near the late Pleistocene last glacial maximum (LGM, approximately 20 ka). Following LGM, mean sea level rose by over 120m to its present elevation. This rise in base level resulted in deposition of alluvial sediment in coastal valleys that had been v-shaped and downcutting prior to and during LGM. These valleys now have broad, low gradient floors formed by alluvial sediment, and the thick alluvial strata filling these valleys cover the toes of late Pleistocene landslides. In this study, three examples of large, deep-seated Pleistocene landslides that are buttressed by alluvium are presented. The McCracken Hill Landslide in Orange County and the Potrero Canyon Landslide Complex in Monterey County are located approximately 1.5 and 6 km, respectively, from the modern Pacific shore and closely fit the eustatic model of alluvial buttressing. At Knights Valley, in the upper Russian River watershed of eastern Sonoma County, a deep-seated alluvium-buttressed landslide is located approximately 65 km from the modern shore (measured along the Russian River and its tributary stream). The alluvium in Knights Valley may have ponded due to late Quaternary tectonic uplift of hills west of the valley. Streams that cross these hills are incised into bedrock downstream from Knights Valley and approaching the Russian River. Thus, the Knights Valley example (of an alluvium-buttressed landslide) demonstrates a rare exception to the broadly applicable eustatic model.

GREAT II (Upper Mississippi River. Guttenberg, Iowa to Saverton, Missouri). Side Channel Work Group Appendix

DTIC Science & Technology

1980-12-01

is current during normal river stage. The graduations in this category are wide- spread, ranging frcm fast flowing watercourses with high banks to...channel category on the other. They may be former side channels that have been cut off, or that have only intermittent flows in them. They may be...navigation project certainly is a contributor by providing a deep channel and an abundance of beaches. Karaki and Van Hoften noted that small, fast

Character and distribution of borehole breakouts and their relationship to in situ stresses in deep Columbia River Basalts ( Washington State, USA).

USGS Publications Warehouse

Paillet, Frederick L.; Kim, K.

1987-01-01

The character and distribution of borehole breakouts in deeply buried basalts at the Hanford Site in S central Washington State are examined in light of stress indicator data and hydraulic- fracturing stress data by means of acoustic televiewer and acoustic waveform logging systems. A series of boreholes penetrating the Grande Ronde Basalt of the Columbia River Basalt Group were logged to examine the extent of breakouts at depths near 1000 m. -from Authors

Nile River, Lake Nasser, Aswan High Dam, Egypt

NASA Technical Reports Server (NTRS)

1992-01-01

The Aswan High Dam, 2.5 miles across and 364 feet high, (24.0N, 33.0E) completed in 1971, was constructed to supply cheap hydroelectric power to both Egypt and Sudan by impounding, controling and regulating the flood waters of the Nile River in Lake Nasser, the world's second largest artifical lake. The lake extends over 500 miles in length, covers an area of some 2,000 square miles and is as much as 350 feet deep at the face of the dam.

Bed load transport by submerged jets

PubMed Central

Francis, J. R. D.; McCreath, P. S.

1979-01-01

Some similarities are presented between the bed load transport of noncohesive grains in long rivers and at a local, jet-induced scour. Experiments are described in which a submerged two-dimensional slot nozzle, inclined downward, eroded a deep sand bed. The rate of erosion at the very beginning of a scour was evaluated and compared with river data by use of the idea of “stream-power.” Empirical relationships for the two cases are similar, although the geometry of the boundaries is quite different. PMID:16592696

A National Strategy is Needed to Prevent the Coming Water War: The Mississippi River Watershed Shows Us Why

DTIC Science & Technology

2014-03-01

200 words ) The Mississippi River watershed is currently managed as six separate basins including the Missouri, Illinois, Ohio, Arkansas, and...that Congress set in 1896 when they gave the USACE authorization to maintain a 9 foot deep by 250 foot wide channel from Cairo to the mouth of the...Sea-level rise will impact the watershed. As the sea-level rises over time, it puts pressure on the outflow of the watershed at the mouth of the

An Archaeological Survey of Selected Portions of the Lower and Middle Sheyenne River Basin in North Dakota

DTIC Science & Technology

1979-01-01

along the .beaches of glacial Lake Agassiz in Manitoba (Saylor 1975). The Plano Culture followed and was partially contemporaneous 4 with the Folsom...Culture in parts of the northern Plains. However, no Plano -like artifacts have been recovered in the Sheyenne River basin, and they are not abundant in...vertical incisions on the neck. The boss protrudes from the exterior *" surface and is 5.7 mm deep and 5.7 mm in diameter. The vertical incisions , made

Presence of faecal indicator bacteria in groundwaters in Kathmandu Valley, Nepal

NASA Astrophysics Data System (ADS)

Nishida, K.; Shrestha, S.; Tanaka, Y.; Haramoto, E.; Nakamura, T.; Osaka, K.; Chapagain, S.

2010-12-01

Groundwater quality is a critical problem in Kathmandu Valley, Nepal. The population of the city increased 6 times in the last six decades and more than half of water demand depends on groundwater resource. Nevertheless, few data of microorganism presence have been reported qualitatively in the central area of the valley. We investigated distribution of faecal indicator bacteria (Total coliforms and Escherichia coli) detected in wells and analyzed the variations of the concentrations. Groundwater samples were collected from 12 deep tube wells (170-300m depths) and 36 shallow tube wells and dug wells (3-20m depths) in Aug 2008, Jan 2009, Aug 2009 and Aug 2010. River waters were also collected for analyzing effect on groundwater quality. E. coli was detected from most of all wells; the concentrations were within 1 log cfu/100mL in deep tube wells and shallow tube wells while those in dug wells ranged from 1 to 3 log cfu/100mL. E. coli was detected at extremely high level in river water, from 5 to 7 log cfu/100mL, however, no clear relation was observed between E. coli concentrations in any types of groundwaters and distance of wells from adjacent rivers. These results indicate that both types of tube wells were rather protected and dug wells were most vulnerable for faecal contamination at very local scale. Genetic analysis of bacterial communities for deep well samples showed the existence of Enterobacter, Acinetobacter as well as Methane-metabolizing groups which provide information of possible indicators other than total coliforms or E. coli for groundwater management in the valley.

Source water controls on the character and origin of dissolved organic matter in streams of the Yukon River basin, Alaska

USGS Publications Warehouse

O'Donnell, Jonathan A.; Aiken, George R.; Kane, Evan S.; Jones, Jeremy B.

2010-01-01

Climate warming and permafrost degradation at high latitudes will likely impact watershed hydrology, and consequently, alter the concentration and character of dissolved organic carbon (DOC) in northern rivers. We examined seasonal variation of DOC chemistry in 16 streams of the Yukon River basin, Alaska. Our primary objective was to evaluate the relationship between source water (shallow versus deep groundwater flow paths) and DOC chemical composition. Using base cation chemistry and principal component analysis, we observed high contributions of deep groundwater to glacial and clearwater streams, whereas blackwater streams received larger contributions from shallow groundwater sources. DOC concentration and specific ultraviolet absorbance peaked during spring snowmelt in all streams, and were consistently higher in blackwater streams than in glacial and clearwater streams. The hydrophobic acid fraction of DOC dominated across all streams and seasons, comprising between 35% and 56% of total DOC. The hydrophilic acid fraction of DOC was more prominent in glacial (23% ± 3%) and clearwater streams (19% ± 1%) than in blackwater streams (16% ± 1%), and was enriched during winter base flow (29% ± 1%) relative to snowmelt and summer base flow. We observed that an increase in the contribution of deep groundwater to streamflow resulted in decreased DOC concentration, aromaticity, and DOC-to-dissolved organic nitrogen ratio, and an increase in the proportion of hydrophilic acids relative to hydrophobic acids. Our findings suggest that future permafrost degradation and higher contributions of groundwater to streamflow may result in a higher fraction of labile DOM in streams of the Yukon basin.

Assessment of chevron dikes for the enhancement of physical-aquatic habitat within the Middle Mississippi River, USA

NASA Astrophysics Data System (ADS)

Remo, J. W.; Pinter, N.

2012-12-01

Along the Middle Mississippi River (MMR), rehabilitation of aquatic habitat is being undertaken using river-training structures such as the blunt-nose chevron dike. Chevron dikes were initially designed to concentrate flow and thus facilitate river navigation, but this new river-training structure is now justified, in part, as a tool for creating aquatic habitat and promoting habitat heterogeneity. The ability of chevrons to create and diversify physical-aquatic habitat has not been verified. In this study, we used 2-D hydrodynamic modeling and reach-scale habitat metrics to assess changes in physical habitat and habitat heterogeneity for pre-chevron and post-chevron along a 2- km reach of the Mississippi River at St. Louis, MO. A historic reference condition (circa 1890) was also modeled to compare physical habitat in a less engineered river channel versus the new physical-habitat patches created by chevron-dike enhancement. This modeling approach quantified changes in habitat availability and diversity among selected reference conditions for a wide range of in-channel flows. Depth-velocity habitat classes were used for assessment of change in physical-habitat patches, and spatial statistical tools were employed to evaluate the reach-scale habitat patch diversity. Modeling of post-chevron channel conditions revealed increases in deep to very deep (>3.0 m) areas of slow moving (<0.6 m/s) water downstream of these structures under emergent flow conditions (≤ 1.5 x mean annual flow[MAF]) relative to pre-construction conditions. Chevron construction increased potential over-wintering habitat (deep [>3.0 m], low velocity [<0.6 m/s]) by up to 7.6 ha. The addition of the chevrons to the river channel also created some (0.8-3.8 ha) shallow-water habitat (0-1.5 m depth with a 0-0.6 m/s velocity) for flows ≤2.0 x MAF and contributed to an 8-35% increase in physical-habitat diversity compared to pre-chevron channel conditions. Comparison of the historic reference condition (less engineered channel, circa 1890) with the post-chevron channel condition, however, revealed historical conditions consisted of a physical-habitat mosaic comprised of a wider and shallower historic river channel with: very little over-wintering habitat (<0.4 ha), 45-390% more shallow-water habitat (2.4 - 11.0 ha), and 22-83% more physical-habitat diversity. Thus, while chevrons construction within the study reaches increased over-wintering habitat, shallow-water habitat, and physical-habitat diversity relative to the pre-chevron channel condition, the type of physical habitat(s) are different from what was historically found along this reach. Constructing chevrons dikes, or other dike-like structures in the river channel, can change the physical-habitat patch mosaic and likely contribute to small increases in physical-habitat heterogeneity. However, differences in the types, quantity, and diversity of physical-habitat patches created by chevron dikes in comparison to the physical-habitat patch mosaic of historic channel underscore the need for additional research to determine which physical-habitat patches are critical for the recovery of endangered or threatened aquatic organisms.

Uranium isotopes (U-234/U-238) in rivers of the Yukon Basin (Alaska and Canada) as an aid in identifying water sources, with implications for monitoring hydrologic change in arctic regions

USGS Publications Warehouse

Kraemer, Thomas F.; Brabets, Timothy P.

2012-01-01

The ability to detect hydrologic variation in large arctic river systems is of major importance in understanding and predicting effects of climate change in high-latitude environments. Monitoring uranium isotopes (234U and 238U) in river water of the Yukon River Basin of Alaska and northwestern Canada (2001–2005) has enhanced the ability to identify water sources to rivers, as well as detect flow changes that have occurred over the 5-year study. Uranium isotopic data for the Yukon River and major tributaries (the Porcupine and Tanana rivers) identify several sources that contribute to river flow, including: deep groundwater, seasonally frozen river-valley alluvium groundwater, and high-elevation glacial melt water. The main-stem Yukon River exhibits patterns of uranium isotopic variation at several locations that reflect input from ice melt and shallow groundwater in the spring, as well as a multi-year pattern of increased variability in timing and relative amount of water supplied from higher elevations within the basin. Results of this study demonstrate both the utility of uranium isotopes in revealing sources of water in large river systems and of incorporating uranium isotope analysis in long-term monitoring of arctic river systems that attempt to assess the effects of climate change.

The Congolobe project, a multidisciplinary study of Congo deep-sea fan lobe complex: Overview of methods, strategies, observations and sampling

NASA Astrophysics Data System (ADS)

Rabouille, C.; Olu, K.; Baudin, F.; Khripounoff, A.; Dennielou, B.; Arnaud-Haond, S.; Babonneau, N.; Bayle, C.; Beckler, J.; Bessette, S.; Bombled, B.; Bourgeois, S.; Brandily, C.; Caprais, J. C.; Cathalot, C.; Charlier, K.; Corvaisier, R.; Croguennec, C.; Cruaud, P.; Decker, C.; Droz, L.; Gayet, N.; Godfroy, A.; Hourdez, S.; Le Bruchec, J.; Saout, J.; Le Saout, M.; Lesongeur, F.; Martinez, P.; Mejanelle, L.; Michalopoulos, P.; Mouchel, O.; Noel, P.; Pastor, L.; Picot, M.; Pignet, P.; Pozzato, L.; Pruski, A. M.; Rabiller, M.; Raimonet, M.; Ragueneau, O.; Reyss, J. L.; Rodier, P.; Ruesch, B.; Ruffine, L.; Savignac, F.; Senyarich, C.; Schnyder, J.; Sen, A.; Stetten, E.; Sun, Ming Yi; Taillefert, M.; Teixeira, S.; Tisnerat-Laborde, N.; Toffin, L.; Tourolle, J.; Toussaint, F.; Vétion, G.; Jouanneau, J. M.; Bez, M.; Congolobe Group:

2017-08-01

The presently active region of the Congo deep-sea fan (around 330,000 km2), called the terminal lobes or lobe complex, covers an area of 2500 km2 at 4700-5100 m water depth and 750-800 km offshore. It is a unique sedimentary area in the world ocean fed by a submarine canyon and a channel-levee system which presently deliver large amounts of organic carbon originating from the Congo River by turbidity currents. This particularity is due to the deep incision of the shelf by the Congo canyon, up to 30 km into the estuary, which funnels the Congo River sediments into the deep-sea. The connection between the river and the canyon is unique for major world rivers. In 2011, two cruises (WACS leg 2 and Congolobe) were conducted to simultaneously investigate the geology, organic and inorganic geochemistry, and micro- and macro-biology of the terminal lobes of the Congo deep-sea fan. Using this multidisciplinary approach, the morpho-sedimentary features of the lobes were characterized along with the origin and reactivity of organic matter, the recycling and burial of biogenic compounds, the diversity and function of bacterial and archaeal communities within the sediment, and the biodiversity and functioning of the faunal assemblages on the seafloor. Six different sites were selected for this study: Four distributed along the active channel from the lobe complex entrance to the outer rim of the sediment deposition zone, and two positioned cross-axis and at increasing distance from the active channel, thus providing a gradient in turbidite particle delivery and sediment age. This paper aims to provide the general context of this multidisciplinary study. It describes the general features of the site and the overall sampling strategy and provides the initial habitat observations to guide the other in-depth investigations presented in this special issue. Detailed bathymetry of each sampling site using 0.1-1 m resolution multibeam obtained with a remotely operated vehicle (ROV) shows progressive widening and smoothing of the channel-levees with increasing depth and reveals a complex morphology with channel bifurcations, erosional features and massive deposits. Dense ecosystems surveyed in the study area gather high density clusters of two large-sized species of symbiotic Vesicomyidae bivalves and microbial mats. These assemblages, which are rarely observed in sedimentary zones, resemble those based on chemosynthesis at cold-seep sites, such as the active pockmarks encountered along the Congo margin, and share with these sites the dominant vesicomyid species Christineconcha regab. Sedimentation rates estimated in the lobe complex range between 0.5 and 10 cm yr-1, which is 2-3 orders of magnitude higher than values generally encountered at abyssal depths. The bathymetry, faunal assemblages and sedimentation rates make the Congo lobe complex a highly peculiar deep-sea habitat driven by high inputs of terrigenous material delivered by the Congo channel-levee system.

Programmable Off-The-Shelf cell-enabled GPS loggers optimized for retrieving after being used as a float in large river experiments.

NASA Astrophysics Data System (ADS)

Hut, Rolf; Bogaard, Thom

2017-04-01

Throwing something in a river and seeing how fast it floats downstream is the first thing that every hydrologists does when encountering a new river. Using a collection of floats allows estimation of gauge surface water velocity and dispersion characteristics. To use floats over long (hundreds of kilometers) stretches of river requires either a crew that keeps an eye on the floats (labor intensive) or having high-tech floats that upload their location on regular intervals, such that they can be retrieved at the end of the experiment. GPS floats with communication units have been custom build by scientists before. Connecting GPS units to GSM modems used to require deep knowledge on micro-electronics and network protocols. In this work we present a version that is build using only off-the-shelf electronics that require no deep knowledge of either micro electronics nor network protocols. The new cellular enabled Particle Electron development board made it possible to connect a Sparkfun OpenLog (SD-card based logger) to a GPS tracker with no soldering and little programming. Because scientist can program the device themselves, settings like sample time can be adapted to the needs of specific experiments and additional sensors can be easily added. When writing GPS location every minute to SD and reporting every fifteen minutes online, our logger can run for three days on a single 2200 mAh LiPo battery (provided with the Particle Electron). Cost of components for our logger is less than 150. The durability of our GPS loggers will be tested during a field campaign at the end of January 2017 where 15 floats will float down the Irrawaddy river over a length of more than 200 km, during two days.

Holocene history of deep-seated landsliding in the North Fork Stillaguamish River valley from surface roughness analysis, radiocarbon dating, and numerical landscape evolution modeling

NASA Astrophysics Data System (ADS)

Booth, Adam M.; LaHusen, Sean R.; Duvall, Alison R.; Montgomery, David R.

2017-02-01

Documenting spatial and temporal patterns of past landsliding is a challenging step in quantifying the effect of landslides on landscape evolution. While landslide inventories can map spatial distributions, lack of dateable material, landslide reactivations, or time, access, and cost constraints generally limit dating large numbers of landslides to analyze temporal patterns. Here we quantify the record of the Holocene history of deep-seated landsliding along a 25 km stretch of the North Fork Stillaguamish River valley, Washington State, USA, including the 2014 Oso landslide, which killed 43 people. We estimate the ages of more than 200 deep-seated landslides in glacial sediment by defining an empirical relationship between landslide deposit age from radiocarbon dating and landslide deposit surface roughness. We show that roughness systematically decreases with age as a function of topographic wavelength, consistent with models of disturbance-driven soil transport. The age-roughness model predicts a peak in landslide frequency at 1000 calibrated (cal) years B.P., with very few landslide deposits older than 7000 cal years B.P. or younger than 100 cal years B.P., likely reflecting a combination of preservation bias and a complex history of changing climate, base level, and seismic shaking in the study area. Most recent landslides have occurred where channels actively interact with the toes of hillslopes composed of glacial sediments, suggesting that lateral channel migration is a primary control on the location of large deep-seated landslides in the valley.

Morphometry and mixing regime of a tropical lake: Lake Nova (Southeastern Brazil).

PubMed

Gonçalves, Monica A; Garcia, Fábio C; Barroso, Gilberto F

2016-09-01

Lake Nova (15.5 km2) is the second largest lake in the Lower Doce River Valley (Southeastern Brazil). A better understanding of ecosystem structure and functioning requires knowledge about lake morphometry, given that lake basin form influences water column stratification. The present study aims to contribute to the understanding of relationship between morphometry and mixing patterns of deep tropical lakes in Brazil. Water column profiles of temperature and dissolved oxygen were taken on four sampling sites along the lake major axis during 2011, 2012 and 2013. The bathymetric survey was carried out in July 2011, along 131.7 km of hydrographic tracks yield 51,692 depth points. Morphometric features of lake size and form factors describe the relative deep subrectangular elongated basin with maximum length of 15.7 km, shoreline development index 5.0, volume of 0.23 km3, volume development of 1.3, and maximum, mean and relative depths of 33.9 m, 14.7 m and 0.7 %, respectively. The deep basin induces a monomictic pattern, with thermal stratification during the wet/warm season associated with anoxic bottom waters (1/3 of lake volume), and mixing during dry and cool season. Based on in situ measurements of tributary river discharges, theoretical retention time (RT) has been estimated in 13.4 years. The morphometry of Lake Nova promote long water RT and the warm monomictic mixing pattern, which is in accordance to the deep tropical lakes in Brazil.

Late 20th Century Deep-seated Vertical Motions in New Orleans and implications for Gulf Coast Subsidence

NASA Astrophysics Data System (ADS)

Dokka, R. K.

2010-12-01

Subsidence of the Mississippi River delta and adjoining coastal areas is widely thought to be dominated by compaction of Holocene sediments. Current public policies regarding hurricane protection and ecosystems restoration are founded on this interpretation. To test this hypothesis, monuments that penetrate the entire Holocene section were measured using geodetic leveling and water gauges attached to bridge foundations. Results show that the entire sampling area subsided between 1955 and 1995 in amounts unanticipated by previous models. Subsidence due to processes originating below the Holocene section locally exceeded 0.9 m between 1955 and 1995. The maxima of deep subsidence occurred in the urbanized and industrialized sections of eastern New Orleans. Subsidence decreased away from urbanized areas and north of the belt of active basin margin normal faults; this decrease in subsidence continued to the north and east along the Mississippi coast. These independent measurements provide insights into the complexity and causes of modern landscape change in the region. Modern subsidence is clearly not dominated solely by shallow processes such as natural compaction, Deep subsidence occurring east and north of the basin margin faults can be explained by regional tectonic loading of the lithosphere by the modern Mississippi River delta and local groundwater withdrawal. Sharp, local changes in subsidence coincide with strands of the basin margin normal fault system. Deep subsidence of the New Orleans area can be explained by a combination of groundwater withdrawal from shallow upper Pleistocene aquifers, the aforementioned lithospheric loading, and non-groundwater-related faulting. Subsidence due to groundwater extraction from aquifers ~160 to 200 m deep dominated the urbanized areas from ~1960 to the early 1990s and is likely responsible for lowering flood protection structures and bridges in the area by as much as ~0.8 m.

Early diagenesis in the sediments of the Congo deep-sea fan dominated by massive terrigenous deposits: Part II - Iron-sulfur coupling

NASA Astrophysics Data System (ADS)

Taillefert, Martial; Beckler, Jordon S.; Cathalot, Cécile; Michalopoulos, Panagiotis; Corvaisier, Rudolph; Kiriazis, Nicole; Caprais, Jean-Claude; Pastor, Lucie; Rabouille, Christophe

2017-08-01

Deep-sea fans are well known depot centers for organic carbon that should promote sulfate reduction. At the same time, the high rates of deposition of unconsolidated metal oxides from terrigenous origin may also promote metal-reducing microbial activity. To investigate the eventual coupling between the iron and sulfur cycles in these environments, shallow sediment cores (< 50 cm) across various channels and levees in the Congo River deep-sea fan ( 5000 m) were profiled using a combination of geochemical methods. Interestingly, metal reduction dominated suboxic carbon remineralization processes in most of these sediments, while dissolved sulfide was absent. In some 'hotspot' patches, however, sulfate reduction produced large sulfide concentrations which supported chemosynthetic-based benthic megafauna. These environments were characterized by sharp geochemical boundaries compared to the iron-rich background environment, suggesting that FeS precipitation efficiently titrated iron and sulfide from the pore waters. A companion study demonstrated that methanogenesis was active in the deep sediment layers of these patchy ecosystems, suggesting that sulfate reduction was promoted by alternative anaerobic processes. These highly reduced habitats could be fueled by discrete, excess inputs of highly labile natural organic matter from Congo River turbidites or by exhumation of buried sulfide during channel flank erosion and slumping. Sulfidic conditions may be maintained by the mineralization of decomposition products from local benthic macrofauna or bacterial symbionts or by the production of more crystalline Fe(III) oxide phases that are less thermodynamically favorable than sulfate reduction in these bioturbated sediments. Overall, the iron and sulfur biogeochemical cycling in this environment is unique and much more similar to a coastal ecosystem than a deep-sea environment.

HYBRIDIZATION AND GEOGRAPHIC VARIATION IN TWO MEADOW KATYDID CONTACT ZONES.

PubMed

Shapiro, Leo H

1998-06-01

In this study, previously unrecognized hybridization was documented between two meadow katydids in each of two disjunct contact zones, in the southeastern United States and along the Potomac River near Washington, DC. These two zones have very different histories and dynamics of interaction between the two taxa. Orchelimum nigripes and O. pulchellum (Tettigoniidae: Conocephalinae) are distributed west and east, respectively, of the Appalachian Mountains, from the Great Lakes to the Gulf Coast and along the Atlantic Coastal Plain from New York to the Florida Keys, but are not found in the Appalachians themselves. In addition, during this century O. nigripes has become established in a small area east of the Appalachians, in the Potomac River basin, where it has completely replaced O. pulchellum along the river corridor above Washington, DC. I sampled katydids from 40 sites across both hybrid zones and mapped geographic patterns of genetic variation (allele frequencies at two diagnostic loci) and variation in a morphometric index for males. Although the two taxa are quite distinct over most of their extensive distributions, there is clear evidence of introgression in both contact zones. In the Deep South, samples from a transect along the Gulf Coast define a broad hybrid zone of about 50-100 km, while samples from a transect 200 km to the north define a zone of about 150-250 km in width. Only one Deep South population shows a deviation from Hardy-Weinberg equilibrium at either locus, and there is no evidence of linkage disequilibrium in any Deep South population. In the Potomac region, there is a narrow upstream-downstream hybrid zone along the river. Within the Potomac River floodplains downriver from Washington, DC, as well as outside the floodplains throughout the region, O. pulchellum is present in abundance, but O. nigripes markers are virtually absent. Within the floodplains upriver from Washington, DC, O. nigripes is abundant, but O. pulch***ellum markers are virtually absent. All four mixed ancestry Potomac populations sampled show strong and highly significant linkage disequilibrium, although only one clearly deviates from single-locus Hardy-Weinberg equilibrium. The position of the Deep South hybrid zone is generally consistent with interspecific and intraspecific phylogeographic patterns previously reported for numerous taxa from the southeastern United States. The observed genetic and morphometric clines appear to be the result of neutral introgression over thousands of years. In the much younger Potomac hybrid zone, O. nigripes appears to be spreading downriver, interbreeding with O. pulchellum, and replacing it. The mechanism for this replacement remains uncertain, but may be clarified by ongoing behavioral, genetic, and breeding studies. © 1998 The Society for the Study of Evolution.

Detection of microcystins, a blue-green algal hepatotoxin, in drinking water sampled in Haimen and Fusui, endemic areas of primary liver cancer in China, by highly sensitive immunoassay.

PubMed

Ueno, Y; Nagata, S; Tsutsumi, T; Hasegawa, A; Watanabe, M F; Park, H D; Chen, G C; Chen, G; Yu, S Z

1996-06-01

An epidemiological survey for the causes of a high incidence of primary liver cancer (PLC) in Haimen city, Jian-Su province and Fusui county, Guangxi province in China, found a close correlation between the incidence of PLC and the drinking of pond and ditch water. With an aim to clarify whether microcystins (MC), a hepatotoxic peptide produced by water bloom algae, contaminate the drinking water in the endemic areas of PLC in China, a highly sensitive enzyme-linked immunosorbent assay with a detection limit of 50 pg/ml, was introduced to monitor the MC. Three trials to survey the drinking water were carried out in 1993-1994. Samples, 1135 in total, were collected from different sources such as: ponds, ditches, rivers, shallow wells and deep wells in Haimen city. The first survey in September 1993 found that three out of 14 ditch water specimens were positive for MC, with a range of 90-460 pg/ml. Several toxic algae such as Oscillatoria agardhii were present in some of the ditches. In the second trial, samples were collected from five ponds/ditches, two rivers, two shallow wells and two deep wells monthly for the whole year of 1994. These data showed that MC was highest in June to September, with a range of 62-296 pg/ml. A third trial on the 989 different water samples collected from the different types of water sources in July 1994 revealed that 17% of the pond/ditch water, 32% of the river water, and 4% of the shallow-well water were positive for MC, with averages of 101, 160 and 68 pg/ml respectively. No MC was detected in deep well water. A similar survey on 26 drinking water samples in Fusui, Guangxi province, demonstrated a high contamination frequency of MC in the water of ponds/ditches and rivers but no MC in shallow and deep wells. These data support a hypothesis that the blue-green algal toxin MC in the drinking water of ponds/ditches and rivers, or both, is one of the risk factors for the high incidence of PLC in China. Based on previous findings on the epidemiology of PLC and the present results from the mass screening of MC in the drinking water, an advisory level of MC in drinking water was proposed to below 0.01 microg/l. The combined effect of a potent hepatocarcinogen AFB1 and an intermittent intake of MC in drinking water in the summer season was discussed as an etiology of PLC.

A hybrid deep neural network and physically based distributed model for river stage prediction

NASA Astrophysics Data System (ADS)

hitokoto, Masayuki; sakuraba, Masaaki

2016-04-01

We developed the real-time river stage prediction model, using the hybrid deep neural network and physically based distributed model. As the basic model, 4 layer feed-forward artificial neural network (ANN) was used. As a network training method, the deep learning technique was applied. To optimize the network weight, the stochastic gradient descent method based on the back propagation method was used. As a pre-training method, the denoising autoencoder was used. Input of the ANN model is hourly change of water level and hourly rainfall, output data is water level of downstream station. In general, the desirable input of the ANN has strong correlation with the output. In conceptual hydrological model such as tank model and storage-function model, river discharge is governed by the catchment storage. Therefore, the change of the catchment storage, downstream discharge subtracted from rainfall, can be the potent input candidate of the ANN model instead of rainfall. From this point of view, the hybrid deep neural network and physically based distributed model was developed. The prediction procedure of the hybrid model is as follows; first, downstream discharge was calculated by the distributed model, and then estimates the hourly change of catchment storage form rainfall and calculated discharge as the input of the ANN model, and finally the ANN model was calculated. In the training phase, hourly change of catchment storage can be calculated by the observed rainfall and discharge data. The developed model was applied to the one catchment of the OOYODO River, one of the first-grade river in Japan. The modeled catchment is 695 square km. For the training data, 5 water level gauging station and 14 rain-gauge station in the catchment was used. The training floods, superior 24 events, were selected during the period of 2005-2014. Prediction was made up to 6 hours, and 6 models were developed for each prediction time. To set the proper learning parameters and network architecture of the ANN model, sensitivity analysis was done by the case study approach. The prediction result was evaluated by the superior 4 flood events by the leave-one-out cross validation. The prediction result of the basic 4 layer ANN was better than the conventional 3 layer ANN model. However, the result did not reproduce well the biggest flood event, supposedly because the lack of the sufficient high-water level flood event in the training data. The result of the hybrid model outperforms the basic ANN model and distributed model, especially improved the performance of the basic ANN model in the biggest flood event.

Distal deltaic deposits document hydrological variability during the past 30 kyrBP in Lake Towuti, Indonesia

NASA Astrophysics Data System (ADS)

Vogel, Hendrik; Russell, James M.; Yudawati Cahyarini, Sri; Bijaksana, Satria; Wattrus, Nigel; Rethemeyer, Janet; Melles, Martin

2014-05-01

Lake Towuti (2.75°S, 121.5°E; 318 m a.s.l.) is a, 560 km2, 200-m deep tectonic lake at the downstream end of the Malili lake system, a set of five, ancient (1-2 MYr) tectonic lakes in central Sulawesi, Indonesia. The Mahalona River constitutes the largest tributary and connects Lake Towuti with the two upstream lakes Matano and Mahalona. The Mahalona River Delta is prograding into the >200m deep northern basin of Lake Towuti. Tracing past variability of Mahalona River discharge is therefore an important puzzle piece for the understanding of depositional dynamics in Lake Towuti as well as catchment hydrology and hydrological connectivity between the Malili Lakes. Distal deltaic deposits can help identifying past variability in river discharge and delta dynamics. Using highly resolved seismic reflection data collected between 2007-2013 we identified a stack of acoustically laminated reflections in Towuti's extensive and morphologically flat deep northern basin. For detailed characterization of these acoustic features we collected a c. 20m long piston core from the basin centre at 200 m water depth reaching back to c. 30 kyrBP. Sediments in this piston core consist to 75% of mass wasting deposits (MWD) of variable thickness that are intercalated with pelagic muds (25%). MWD appear mostly homogenous (silt- to finesand-sized siliciclastics with high amounts of terrestrial plant macrofossils) with only thin (1-3 cm) basal sand layers and clay caps (<1 cm). Pelagic muds appear as thin to medium bedded slightly silty clays that are clearly distinguishable from MWD. The position of MWD identified in our piston core nicely correlates with acoustically laminated reflections identified in seismic profiles crossing the coring site. Based on these combined sedimentological and acoustic datasets we interpret MWD in Towuti's northern basin as distal deltaic deposits originating from the Mahalona River Delta. Frequencies and percentages (in terms of lithofacies contribution) of distal deltaic deposits differ substantially between the Holocene (56%) and last glacial (88%) sediment succession. In combination with data from hydrological proxies and seismic reflection data indicating dry climate conditions and lake level lowstands, respectively, we interpret the higher frequency of distal deltaic deposits during the last glacial as a result of subaerial exposure and erosion of Mahalona River Delta sediments. These findings imply that frequencies and percentages of distal deltaic deposits in Lake Towuti may be an additional indicator for hydrological variability in this particular system.

Detection of Hydrologic Response at the River Basin Scale Caused by Land Use Change

NASA Astrophysics Data System (ADS)

McCormick, B. C.; Eshleman, K. N.; Griffith, J. L.; Townsend, P. A.

2008-05-01

The 187.5 km2 Georges Creek watershed, located on the Appalachian Plateau in western Maryland (USA), has experienced significant land use change due to surface mining of bituminous coal. We estimate that over 17% of the Georges Creek watershed is being actively surface-mined or was mined and reclaimed previously. The adjacent Savage River watershed (127.2 km2) is completely unaffected by surface mining. Both watersheds have long (>60 year) streamflow records maintained by USGS that were analyzed as part of this project, using Savage River as a control. Temporal analysis of the moments of the flood frequency distributions using a moving-window technique indicated that climatic variability affected both watersheds equally. Normalizing annual maximum flows by antecedent streamflow and causative precipitation allowed trends in the Georges Creek watershed flooding response to become more evident. An analysis of sixteen contemporary warm season storm events based on hourly streamflow and NEXRAD Stage III derived precipitation data provided clear evidence of differences in watershed response to rainfall. Georges Creek events (normalized by basin area and precipitation) are, on average, characterized by slightly greater (7%) peak runoff and shorter (3 hr) centroid lags than Savage River, even though the opposite was expected considering relative basin areas. These differences in stormflow response are most likely attributable to differences in current land use in the basins, particularly the large area of reclaimed minelands in Georges Creek. Interestingly, we found that Georges Creek events produce, on average, only 2/3 of the stormflow volume as Savage River, apparently due to infiltration of water into abandoned deep mine workings and an associated trans-basin drainage system that dates to the early 20th century. Long-term trend analysis at the river basin scale using empirical hydrologic methods is thus complicated by climatic variability and the legacy of deep mining in this system.

Long Valley Caldera Lake and reincision of Owens River Gorge

USGS Publications Warehouse

Hildreth, Wes; Fierstein, Judy

2016-12-16

Owens River Gorge, today rimmed exclusively in 767-ka Bishop Tuff, was first cut during the Neogene through a ridge of Triassic granodiorite to a depth as great as its present-day floor and was then filled to its rim by a small basaltic shield at 3.3 Ma. The gorge-filling basalt, 200 m thick, blocked a 5-km-long reach of the upper gorge, diverting the Owens River southward around the shield into Rock Creek where another 200-m-deep gorge was cut through the same basement ridge. Much later, during Marine Isotope Stage (MIS) 22 (~900–866 ka), a piedmont glacier buried the diversion and deposited a thick sheet of Sherwin Till atop the basalt on both sides of the original gorge, showing that the basalt-filled reach had not, by then, been reexcavated. At 767 ka, eruption of the Bishop Tuff blanketed the landscape with welded ignimbrite, deeply covering the till, basalt, and granodiorite and completely filling all additional reaches of both Rock Creek canyon and Owens River Gorge. The ignimbrite rests directly on the basalt and till along the walls of Owens Gorge, but nowhere was it inset against either, showing that the basalt-blocked reach had still not been reexcavated. Subsidence of Long Valley Caldera at 767 ka produced a steep-walled depression at least 700 m deeper than the precaldera floor of Owens Gorge, which was beheaded at the caldera’s southeast rim. Caldera collapse reoriented proximal drainages that had formerly joined east-flowing Owens River, abruptly reversing flow westward into the caldera. It took 600,000 years of sedimentation in the 26-km-long, usually shallow, caldera lake to fill the deep basin and raise lake level to its threshold for overflow. Not until then did reestablishment of Owens River Gorge begin, by incision of the gorge-filling ignimbrite.

Spectrally-Based Bathymetric Mapping of a Dynamic, Sand-Bedded Channel: Niobrara River, Nebraska, USA

NASA Astrophysics Data System (ADS)

Dilbone, Elizabeth K.

Methods for spectrally-based bathymetric mapping of rivers mainly have been developed and tested on clear-flowing, gravel bedded channels, with limited application to turbid, sand-bedded rivers. Using hyperspectral images of the Niobrara River, Nebraska, and field-surveyed depth data, this study evaluated three methods of retrieving depth from remotely sensed data in a dynamic, sand-bedded channel. The first regression-based approach paired in situ depth measurements and image pixel values to predict depth via Optimal Band Ratio Analysis (OBRA). The second approach used ground-based reflectance measurements to calibrate an OBRA relationship. For this approach, CASI images were atmospherically corrected to units of apparent surface reflectance using an empirical line calibration. For the final technique, we used Image-to-Depth Quantile Transformation (IDQT) to predict depth by linking the cumulative distribution function (CDF) of depth to the CDF of an image derived variable. OBRA yielded the lowest overall depth retrieval error (0.0047 m) and highest observed versus predicted R2 (0.81). Although misalignment between field and image data were not problematic to OBRA's performance in this study, such issues present potential limitations to standard regression-based approaches like OBRA in dynamic, sand-bedded rivers. Field spectroscopy-based maps exhibited a slight shallow bias (0.0652 m) but provided reliable depth estimates for most of the study reach. IDQT had a strong deep bias, but still provided informative relative depth maps that portrayed general patterns of shallow and deep areas of the channel. The over-prediction of depth by IDQT highlights the need for an unbiased sampling strategy to define the CDF of depth. While each of the techniques tested in this study demonstrated the potential to provide accurate depth estimates in sand-bedded rivers, each method also was subject to certain constraints and limitations.

Geotechnical Engineering in US Elementary Schools

ERIC Educational Resources Information Center

Suescun-Florez, Eduardo; Iskander, Magued; Kapila, Vikram; Cain, Ryan

2013-01-01

This paper reports on the results of several geotechnical engineering-related science activities conducted with elementary-school students. Activities presented include soil permeability, contact stress, soil stratigraphy, shallow and deep foundations, and erosion in rivers. The permeability activity employed the LEGO NXT platform for data…

C&S Enterprise, L.L.C.

EPA Pesticide Factsheets

The EPA is providing notice of a proposed Administrative Penalty Assessment against C & S Enterprise, L.L.C. (“Respondent”), a business located at 2454 480th Ave, Deep River, IA 52222, for alleged violations of the Clean Water Act at property owned by Resp

Summer microhabitat use by adult and young-of-year snail darters (Percina tanasi) in two rivers

USGS Publications Warehouse

Ashton, M.J.; Layzer, James B.

2010-01-01

We characterised microhabitat availability and use by adult and young-of-year (YOY) snail darters (Percina tanasi Etnier 1976) while snorkelling in the French Broad and Hiwassee rivers, TN, USA. Both age groups of snail darters disproportionately used most microhabitat variables compared to their availability. Snail darters primarily occupied moderately deep, swift water over gravel substrates with little macrophyte coverage and no silt. Univariate comparisons indicated that adult and YOY darters occupied different habitat, but there was no marked differences between principal components analysis plots of multivariate microhabitat use within a river. Although the availability of microhabitat variables differed between the French Broad and Hiwassee rivers, univariate means and multivariate plots illustrated that the habitats used were generally similar by age groups of snail darters between rivers. Because our observations of habitat availability and use were constrained to low flow periods and depths <1 m, the transferability of our results to higher flow periods may be limited. However, the similarity in habitat use between rivers suggests that our results can be applied to low-normal flow conditions in other streams.

The Ohio River Valley CO2 Storage Project AEP Mountaineer Plan, West Virginia

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

Neeraj Gupta

2009-01-07

This report includes an evaluation of deep rock formations with the objective of providing practical maps, data, and some of the issues considered for carbon dioxide (CO{sub 2}) storage projects in the Ohio River Valley. Injection and storage of CO{sub 2} into deep rock formations represents a feasible option for reducing greenhouse gas emissions from coal-burning power plants concentrated along the Ohio River Valley area. This study is sponsored by the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL), American Electric Power (AEP), BP, Ohio Coal Development Office, Schlumberger, and Battelle along with its Pacific Northwest Division. Anmore » extensive program of drilling, sampling, and testing of a deep well combined with a seismic survey was used to characterize the local and regional geologic features at AEP's 1300-megawatt (MW) Mountaineer Power Plant. Site characterization information has been used as part of a systematic design feasibility assessment for a first-of-a-kind integrated capture and storage facility at an existing coal-fired power plant in the Ohio River Valley region--an area with a large concentration of power plants and other emission sources. Subsurface characterization data have been used for reservoir simulations and to support the review of the issues relating to injection, monitoring, strategy, risk assessment, and regulatory permitting. The high-sulfur coal samples from the region have been tested in a capture test facility to evaluate and optimize basic design for a small-scale capture system and eventually to prepare a detailed design for a capture, local transport, and injection facility. The Ohio River Valley CO{sub 2} Storage Project was conducted in phases with the ultimate objectives of demonstrating both the technical aspects of CO{sub 2} storage and the testing, logistical, regulatory, and outreach issues related to conducting such a project at a large point source under realistic constraints. The site characterization phase was completed, laying the groundwork for moving the project towards a potential injection phase. Feasibility and design assessment activities included an assessment of the CO{sub 2} source options (a slip-stream capture system or transported CO{sub 2}); development of the injection and monitoring system design; preparation of regulatory permits; and continued stakeholder outreach.« less

Typhoon impacts on chemical weathering source provenance of a High Standing Island watershed, Taiwan

NASA Astrophysics Data System (ADS)

Meyer, Kevin J.; Carey, Anne E.; You, Chen-Feng

2017-10-01

Chemical weathering source provenance changes associated with Typhoon Mindulle (2004) were identified for the Choshui River Watershed in west-central Taiwan using radiogenic Sr isotope (87Sr/86Sr) and major ion chemistry analysis of water samples collected before, during, and following the storm event. Storm water sampling over 72 h was conducted in 3 h intervals, allowing for novel insight into weathering regime changes in response to intense rainfall events. Chemical weathering sources were determined to be bulk silicate and disseminated carbonate minerals at the surface and silicate contributions from deep thermal waters. Loss on ignition analysis of collected rock samples indicate disseminated carbonate can compose over 25% by weight of surface mineralogy, but typically makes up ∼2-3% of watershed rock. 87Sr/86Sr and major element molar ratios indicate that Typhoon Mindulle caused a weathering regime switch from normal flow incorporating a deep thermal signature to that of a system dominated by surface weathering. The data suggest release of silicate solute rich soil pore waters during storm events, creating a greater relative contribution of silicate weathering to the solute load during periods of increased precipitation and runoff. Partial depletion of this soil solute reservoir and possible erosion enhanced carbonate weathering lead to increased importance of carbonates to the weathering regime as the storm continues. Major ion data indicate that complex mica weathering (muscovite, biotite, illite, chlorite) may represent an important silicate weathering pathway in the watershed. Deep thermal waters represent an important contribution to river solutes during normal non-storm flow conditions. Sulfuric acid sourced from pyrite weathering is likely a major weathering agent in the Choshui River watershed.

Geochemistry Sampling for Traditional and Multicomponent Equilibrium Geothermometry in Southeast Idaho

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

Cannon, Cody; Wood, Thomas; Neupane, Ghanashyam

2014-10-01

The Eastern Snake River Plain (ESRP) is an area of high regional heat flux due the movement of the North American Plate over the Yellowstone Hotspot beginning ca.16 Ma. Temperature gradients between 45-60 °C/km (up to double the global average) have been calculated from deep wells that penetrate the upper aquifer system (Blackwell 1989). Despite the high geothermal potential, thermal signatures from hot springs and wells are effectively masked by the rapid flow of cold groundwater through the highly permeable basalts of the Eastern Snake River Plain aquifer (ESRPA) (up to 500+ m thick). This preliminary study is part ofmore » an effort to more accurately predict temperatures of the ESRP deep thermal reservoir while accounting for the effects of the prolific cold water aquifer system above. This study combines the use of traditional geothermometry, mixing models, and a multicomponent equilibrium geothermometry (MEG) tool to investigate the geothermal potential of the ESRP. In March, 2014, a collaborative team including members of the University of Idaho, the Idaho National Laboratory, and the Lawrence Berkeley National Laboratory collected 14 thermal water samples from and adjacent to the Eastern Snake River Plain. The preliminary results of chemical analyses and geothermometry applied to these samples are presented herein.« less

Application of carbon isotope stratigraphy to late miocene shallow marine sediments, new zealand.

PubMed

Loutit, T S; Kennett, J P

1979-06-15

A distinct (0.5 per mil) carbon-13/carbon-12 isotopic shift in the light direction has been identified in a shallow marine sedimentary sequence of Late Miocene age at Blind River, New Zealand, and correlated with a similar shift in Late Miocene Deep Sea Drilling Project sequences throughout the Indo-Pacific. A dated piston core provides an age for the shift of 6.2 +/- 0.1 million years. Correlations based on the carbon isotopic change require a revision of the previously established magnetostratigraphy at Blind River. The carbon shift at Blind River occurs between 6.2 and 6.3 +/- 0.1 million years before present. A new chronology provides an age for the evolutionary first appearance datum of Globorotalia conomiozea at 6.1 +/- 0.1 million years, the beginning of a distinct latest Miocene cooling event associated with the Kapitean stage at 6.2 +/- 0.1 million years, and the beginning of a distinct shallowing of water depths at 6.1 +/- 0.1 million years. The Miocene-Pliocene boundary as recognized in New Zealand is now dated at 5.3 +/- 0.1 million years. Extension of carbon isotope stratigraphy to other shallow Late Miocene sequences should provide an important datum for international correlation of Late Miocene shallow and deep marine sequences.

Design for Flood Control, Wave Protection, and Prevention of Shoaling, Rogue River, Oregon. Hydraulic Model Investigation.

DTIC Science & Technology

1982-08-01

Gold Beach docks; a turning basin 10 ft deep, 150 ft wide, and 600 ft long adjacent to the decks; and revetment on the north bank extending approximately...jetty. A ga was left in thetbroan or to ft lde sctaW to arbor fatt.itie. 4. bsrye pPbla oaists beftten the logu River Ij4ties; slag 1 ide 4 f 0 south... revetments are also rubble-mound structures. Experience and experimental research have shown that considerable wave energy passes through the

Field-trip guide to the vents, dikes, stratigraphy, and structure of the Columbia River Basalt Group, eastern Oregon and southeastern Washington

USGS Publications Warehouse

Camp, Victor E; Reidel, Stephen P.; Ross, Martin E.; Brown, Richard J.; Self, Stephen

2017-06-22

The Columbia River Basalt Group covers an area of more than 210,000 km2 with an estimated volume of 210,000 km3. As the youngest continental flood-basalt province on Earth (16.7–5.5 Ma), it is well preserved, with a coherent and detailed stratigraphy exposed in the deep canyonlands of eastern Oregon and southeastern Washington. The Columbia River flood-basalt province is often cited as a model for the study of similar provinces worldwide.This field-trip guide explores the main source region of the Columbia River Basalt Group and is written for trip participants attending the 2017 International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Scientific Assembly in Portland, Oregon, USA. The first part of the guide provides an overview of the geologic features common in the Columbia River flood-basalt province and the stratigraphic terminology used in the Columbia River Basalt Group. The accompanying road log examines the stratigraphic evolution, eruption history, and structure of the province through a field examination of the lavas, dikes, and pyroclastic rocks of the Columbia River Basalt Group.

ELLICOTT ROCK WILDERNESS AND ADDITIONS, SOUTH CAROLINA, NORTH CAROLINA, AND GEORGIA.

USGS Publications Warehouse

Bell, Henry; Gazdik, Gertrude C.

1984-01-01

A mineral survey was made of the Ellicott Rock Wilderness and additions located in the common corner of South Carolina, North Carolina, and Georgia. Surveys along the rivers, streams, and ridges indicated that there is little promise for the occurrence of metallic mineral or energy resources. Deeply buried sedimentary rocks have an unknown potential for hydrocarbons, probably gas. Until some deep drilling is done to test these deep sedimentary rocks no reasonable estimate of gas potential can be made, but it cannot be totally discounted.

3. View of the mouth of George Washington's 'Potowmack' Canal ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. View of the mouth of George Washington's 'Potowmack' Canal at the Great Falls of the Potomac River. The view is taken from a rock in the Potomac River looking up into the Canal. Trees and dense growth now fill the old aperture which once permitted barges to come down the Ohio Valley onto the broad expanse of the Potomac River. This view, taken September 1, 1943, evidences the very low water then existing on the Potomac River, as is clearly shown by the water marks on the rocks on the left hand side of the photograph. That portion where the individual is standing, up to the height of his hat, is normally underwater. Deep in the sand at this spot was found a part of one of the old hand brought lock hinges which formerly swung the first lock gates ... - Potowmack Company: Great Falls Canal, Locks No. 3, 4, 5, Great Falls, Fairfax County, VA

Aquatic habitat change in the Arkansas river after the development of a lock-and-dam commercial navigation system

USGS Publications Warehouse

Schramm, H.L.; Minnis, R.B.; Spencer, A.B.; Theel, R.T.

2008-01-01

The McClellan-Kerr Arkansas River Navigation System (MKARNS), completed in 1971, required the construction of 17 locks and dams and associated navigation works to make the Arkansas and Verdigris Rivers navigable for barge traffic from the Mississippi River to Catoosa, Oklahoma. We used a Geographic Information System to assess habitat changes in the 477-km portion of this system within Arkansas from 1973 to 1999. Total aquatic area declined by 9% from 42 404 to 38 655 ha. Aquatic habitat losses were 1-17% among pools. Greatest habitat losses occurred in diked secondary channels (former secondary channels with flow reduced by rock dikes) and backwaters adjacent to the main channel. Most of the area of dike pools (aquatic habitat downstream of rock dikes), diked secondary channels and adjacent backwaters were <0.9 m deep. Copyright ?? 2008 John Wiley & Sons, Ltd.

Timing and patterns of basin infilling as documented in Lake Powell during a drought

USGS Publications Warehouse

Pratson, Lincoln F.; Hughes-Clarke, John; Anderson, Mark; Gerber, Thomas; Twitchell, David C.; Ferrari, Ronald; Nittrouer, Charles A.; Beaudoin, Jonathan D.; Granet, Jesse; Crockett, John

2008-01-01

Between 1999 and 2005, drought in the western United States led to a >44 m fall in the level of Lake Powell (Arizona-Utah), the nation's second-largest reservoir. River discharges to the reservoir were halved, yet the rivers still incised the tops of deltas left exposed along the rim of the reservoir by the lake-level fall. Erosion of the deltas enriched the rivers in sediment such that upon entering the reservoir they discharged plunging subaqueous gravity flows, one of which was imaged acoustically. Repeat bathymetric surveys of the reservoir show that the gravity flows overtopped rockfalls and formed small subaqueous fans, locally raising sediment accumulation rates 10–100-fold. The timing of deep-basin deposition differed regionally across the reservoir with respect to lake-level change. Total mass of sediment transferred from the lake perimeter to its bottom equates to ~22 yr of river input.

Sub-decadal turbidite frequency during the early Holocene: Eel Fan, offshore northern California

USGS Publications Warehouse

Paull, Charles K.; McGann, Mary L.; Sumner, Esther J; Barnes, Philip M; Lundsten, Eve M.; Anderson, Krystle; Gwiazda, Roberto; Edwards, Brian D.; Caress, David W

2014-01-01

Remotely operated and autonomous underwater vehicle technologies were used to image and sample exceptional deep sea outcrops where an ∼100-m-thick section of turbidite beds is exposed on the headwalls of two giant submarine scours on Eel submarine fan, offshore northern California (USA). These outcrops provide a rare opportunity to connect young deep-sea turbidites with their feeder system. 14C measurements reveal that from 12.8 ka to 7.9 ka, one turbidite was being emplaced on average every 7 yr. This emplacement rate is two to three orders of magnitude higher than observed for turbidites elsewhere along the Pacific margin of North America. The turbidites contain abundant wood and shallow-dwelling foraminifera, demonstrating an efficient connection between the Eel River source and the Eel Fan sink. Turbidite recurrence intervals diminish fivefold to ∼36 yr from 7.9 ka onward, reflecting sea-level rise and re-routing of Eel River sediments.

Sediment-deposition rates and organic compounds in bottom sediment at four sites in Lake Mead, Nevada, May 1998

USGS Publications Warehouse

Covay, K.J.; Beck, D.A.

2001-01-01

In May 1998 the U.S. Geological Survey, in cooperation with the University of Nevada, Las Vegas, investigated rates of sediment deposition and concentrations of selected synthetic organic compounds at four sites in Lake Mead. Sediment cores were extracted from two sites (one shallow and one deep) in Las Vegas Bay, from one site in the Overton Arm, and from one site near the historic confluence of the Colorado and Virgin Rivers. The sediment cores were age-dated using cesium-137 and were analyzed for the presence of organochlorine compounds (pesticides and degradation products, polychlorinated biphenyls, dioxins, and furans) and for semivolatile organic compounds (polycyclic aromatic hydrocarbons and phenols). Sediment-deposition rates after impoundment of the Colorado River by Hoover Dam were determined by measuring the accumulation of mass during three different periods: (1) from the approximate impoundment date for each site (1935-37) to the initial occurrence of cesium-137 in the atmosphere (1952); (2) from 1952 to the maximum concentration of cesium-137 in the atmosphere (1964); and (3) from 1964 to the collection date of the sample (1998). Sediment-deposition rates for the entire post-impoundment period (1935-98) averaged 1.45 (g/cm2)/yr (grams per square centimeter per year) at the Las Vegas Bay shallow site, 1.25 (g/cm2)/yr at the Las Vegas Bay deep site, 0.80 (g/cm2)/yr at the Overton Arm site, and 0.65 (g/cm2)/yr at the Colorado and Virgin Rivers confluence site. Sediment-deposition rates after impoundment of the Colorado River by Hoover Dam were determined by measuring the accumulation of mass during three different periods: (1) from the approximate impoundment date for each site (1935-37) to the initial occurrence of cesium-137 in the atmosphere (1952); (2) from 1952 to the maximum concentration of cesium-137 in the atmosphere (1964); and (3) from 1964 to the collection date of the sample (1998). Sediment-deposition rates for the entire post-impoundment period (1935-98) averaged 1.45 (g/cm2)/yr (grams per square centimeter per year) at the Las Vegas Bay shallow site, 1.25 (g/cm2)/yr at the Las Vegas Bay deep site, 0.80 (g/cm2)/yr at the Overton Arm site, and 0.65 (g/cm2)/yr at the Colorado and Virgin Rivers confluence site. Total numbers of synthetic organic compounds detected in sediment samples were 48 at the Las Vegas Bay shallow site, 57 at the Las Vegas Bay deep site, 26 at the Overton Arm site, and 31 at the Colorado and Virgin Rivers confluence site. The most commonly detected organochlorine pesticide and polychlorinated biphenyl compounds were dichlorodiphenyldichloroethane and dichlorodiphenyldichloroethylene. The most commonly detected dioxin compounds were tetrachlorodibenzo-p-dioxin and octochlorodibenzo-p-dioxin. The most commonly detected furan compounds were tetrachlorodibenzofuran and octochlorodibenzofuran. The most commonly detected polycyclic aromatic hydrocarbons included perylene, benzo[g,h,i]perylene, 2,6-dimethylnaphthalene, and indeno[1,2,3-c,d]pyrene. The most commonly detected phenol compound was phenol.

Hydrologic data for the Obed River watershed, Tennessee

USGS Publications Warehouse

Knight, Rodney R.; Wolfe, William J.; Law, George S.

2014-01-01

The Obed River watershed drains a 520-square-mile area of the Cumberland Plateau physiographic region in the Tennessee River basin. The watershed is underlain by conglomerate, sandstone, and shale of Pennsylvanian age, which overlie Mississippian-age limestone. The larger creeks and rivers of the Obed River system have eroded gorges through the conglomerate and sandstone into the deeper shale. The largest gorges are up to 400 feet deep and are protected by the Wild and Scenic Rivers Act as part of the Obed Wild and Scenic River, which is managed by the National Park Service. The growing communities of Crossville and Crab Orchard, Tennessee, are located upstream of the gorge areas of the Obed River watershed. The cities used about 5.8 million gallons of water per day for drinking water in 2010 from Lake Holiday and Stone Lake in the Obed River watershed and Meadow Park Lake in the Caney Fork River watershed. The city of Crossville operates a wastewater treatment plant that releases an annual average of about 2.2 million gallons per day of treated effluent to the Obed River, representing as much as 10 to 40 percent of the monthly average streamflow of the Obed River near Lancing about 35 miles downstream, during summer and fall. During the past 50 years (1960–2010), several dozen tributary impoundments and more than 2,000 small farm ponds have been constructed in the Obed River watershed. Synoptic streamflow measurements indicate a tendency towards dampened high flows and slightly increased low flows as the percentage of basin area controlled by impoundments increases.

Uplifted Yellow river terraces across the Haiyuan fault, China and their implications to geometrical complexity of strike-slip fault system

NASA Astrophysics Data System (ADS)

Liu, J.; van der Woerd, J.; Li, Z.; Klinger, Y.; Matrau, R.; Shao, Y.; Zhang, J.; Wang, P.

2016-12-01

Geometrical complexities and discontinues, such as fault bends, splays and step-overs, are common along large strike-slip faults. Numerical and observational studies show that geometrical complexities above some threshold degree may inhibit thoroughgoing rupture, limiting rupture length and the size of the resulting earthquake. Studying the fine structure and long-term evolution of fault step-overs would help us better understand their effect on earthquake ruptures. In this study, we focus on a prominent geometrical "knot" on the left-lateral Haiyuan fault, where the fault curves with multi-strand splays bounding the Mijia Shan-Hasi Shan ranges. Incidentally, the Yellow river flows between the Mijia Shan and Hasi Shan and cuts a deep gorge when crossing the fault. On the western bank of the river, a series of at least twelve levels of fluvial strath terraces perch above river bed, and are capped with no more than 5 meters of alluvial deposits. We measured the terrace heights above river bed, using RTK and UAV surveys. We collected quartz-rich pebbles of yellow river gravel for cosmogenic radio nuclide (CRN), and silt layers within gravel and the overlying loess cap for optimally stimulated luminescence (OSL) dating to constrain the terrace formation ages. Quartz-rich pebbles were sampled both in hand-dug pit for depth-profile method and surface samples on terrace surfaces. The CRN age results were corrected in terms of inheritance and shielding by loess. The dates and heights of serial terraces yielded an average uplift rate of 2±0.34 mm/yr, which represents the late Quaternary uplifting rate of the Mijia Shan. The uplift of the Mijia Shan-Hasi Shan may result from the oblique shear of positive flower in the deep crust of the left-lateral Haiyuan fault. We further speculate that with progressively uplifted mountain ranges, the active fault trace shifts with time among the multi-strands of the fault system. In addition, the coincidence of prominent uplifted mountains at the position where the Yellow river cut across the left-lateral strike-slip fault suggests that Yellow river may play a role in enhancing the uplifting rate, though efficient mass unloading.

Sources and transport of algae and nutrients in a Californian river in a semi-arid climate

USGS Publications Warehouse

Ohte, N.; Dahlgren, R.A.; Silva, S.R.; Kendall, C.; Kratzer, C.R.; Doctor, D.H.

2007-01-01

1. To elucidate factors contributing to dissolved oxygen (DO) depletion in the Stockton Deep Water Ship Channel in the lower San Joaquin River, spatial and temporal changes in algae and nutrient concentrations were investigated in relation to flow regime under the semiarid climate conditions. 2. Chlorophyll-a (chl-a) concentration and loads indicated that most algal biomass was generated by in-stream growth in the main stem of the river. The addition of algae from tributaries and drains was small (c.15% of total chl-a load), even though high concentrations of chl-a were measured in some source waters. 3. Nitrate and soluble-reactive phosphorus (SRP) were available in excess as a nutrient source for algae. Although nitrate and SRP from upstream tributaries contributed (16.9% of total nitrate load and 10.8% of total SRP load), nutrients derived from agriculture and other sources in the middle and lower river reaches were mostly responsible (20.2% for nitrate and 48.0% for SRP) for maintaining high nitrate and SRP concentrations in the main stem. 4. A reduction in nutrient discharge would attenuate the algal blooms that accelerate DO depletion in the Stockton Deep Water Ship Channel. The N : P ratio, in the main stem suggests that SRP reduction would be a more viable option for algae reduction than nitrogen reduction. 5. Very high algal growth rates in the main stem suggest that reducing the algal seed source in upstream areas would also be an effective strategy. ?? 2007 Blackwell Publishing Ltd.

ATMOSPHERIC TRACER EXPERIMENTS IN A DEEP NARROW VALLEY

EPA Science Inventory

A set of three atmospheric tracer experiments was conducted in the Brush Creek Valley of western Colorado in the summer of 1982 as part of the U.S. Environmental Protection Agency Green River Ambient Model Assessment (GRAMA) program in conjunction with the U.S. Department of Ener...

Constancy in the vegetation of the Amazon Basin during the late Pleistocene: Evidence from the organic matter composition of Amazon deep sea fan sediments

NASA Astrophysics Data System (ADS)

Kastner, Thomas P.; Goñi, Miguel A.

2003-04-01

Analyses of more than 60 sediment samples from the Amazon deep sea fan show remarkably constant terrigenous biomarkers (lignin phenols and cutin acids) and stable carbon isotopic compositions of organic matter (δ13COM) deposited from 10 to 70 ka. Sediments from the nine Amazon deep sea fan channel-levee systems investigated in this study yielded relatively narrow ranges for diagnostic parameters such as organic carbon (OC) normalized total lignin yields (Λ = 3.1 ± 1.1 mg/100 mg OC), syringyl:vanillyl phenol ratios (S/V = 0.84 ± 0.06), cinnamyl:vanillyl phenol ratios (C/V = 0.08 ± 0.02), isomeric abundances of cutin-derived dihydroxyhexadecanoic acid (f10,16-OH = 0.65 ± 0.02), and δ13COM (-27.6% ± 0.6 ‰). Our measurements support the hypothesis that the vegetation of the Amazon Basin did not change significantly during the late Pleistocene, even during the Last Glacial Maximum. Moreover, the compositions obtained from the Amazon deep sea fan are similar to those of modern Amazon River suspended sediments. Such results strongly indicate that the current tropical rainforest vegetation has been a permanent and dominant feature of the Amazon River watershed over the past 70 k.y. Specifically, we found no evidence for the development of large savannas that had been previously postulated as indicators of increased glacial aridity in Amazonia. Climate models need to be modified to account for the uninterrupted input of moisture to the tropical Amazon region over the late Pleistocene Holocene period.

Trends in nitrogen concentration and nitrogen loads entering the South Shore Estuary Reserve from streams and ground-water discharge in Nassau and Suffolk counties, Long Island, New York, 1952–97

USGS Publications Warehouse

Monti, Jack; Scorca, Michael P.

2003-01-01

The 13 major south-shore streams in Nassau and Suffolk Counties, Long Island, New York with adequate long-term (1971-97) water-quality records, and 192 south-shore wells with sufficient water-quality data, were selected for analysis of geographic, seasonal, and long-term trends in nitrogen concentration. Annual total nitrogen loads transported to the South Shore Estuary Reserve (SSER) from 11 of these streams were calculated using long-term discharge records. Nitrogen loads from shallow and deep ground water also were calculated using simulated ground-water discharge of 1968-83 hydrologic conditions.Long-term declines in stream discharge occurred in East Meadow Brook, Bellmore Creek and Massapequa Creek in response to extensive sewering in Nassau County. The smallest longterm annual discharge to the SSER was from the westernmost stream, Pines Brook, which is in an area in which the water table has been lowered by sewers since 1952. The three largest average annual discharges to the SSER were from the Connetquot River, Carlls River, and Carmans River in Suffolk County; the discharges from each of these streams were at least twice those of the other streams considered in this study.Total nitrogen concentrations in streams show a geographic trend with a general eastward increase in median total nitrogen concentration in Nassau County and a decreasing trend from Massapequa Creek eastward into Suffolk County. Total nitrogen concentrations in streams generally are lowest during summer and highest in winter as a result of seasonal fluctuations in chemical reactions and biological activity. The greatest seasonal difference in median total nitrogen concentration was at Carlls River with values of 3.4 and 4.2 mg/L (milligrams per liter) as N during summer (April through September) and winter (October through March), respectively. Streams affected by the completion of sewer districts show long-term (1971-97) trends of decreasing total nitrogen concentration and streams showing an increase in total nitrogen concentration are in unsewered areas with increased urbanization.Discharges from shallow ground water (upper glacial aquifer) and deep ground water (upper part of Magothy aquifer) were simulated from a ground-water-flow model calibrated to steadystate (1968-83) conditions. Simulated discharges from shallow-ground-water system in Nassau County were 10,700 Mgal/yr (million gallons per year) or 40,500,000 m3/yr (cubic meters per year), and those from Suffolk County were 52,300 Mgal/yr or 198,000,000 m3/yr. Discharges from deep-ground-water system in Nassau County were 4,900 Mgal/yr or 18,500,000 m3/yr, and those in Suffolk County were 12,700 Mgal/yr or 48,200,000 m3/yr.Ground-water concentrations of nitrogen decrease with depth and from west to east. The shallow ground water median nitrogen concentration for each county was determined using 1,155 samples collected at 167 shallow wells (125 feet deep or less) within 1 mile of the shore. The deep ground water median nitrate concentration (nitrate represented almost all of the total nitrogen) for each county was determined using 112 samples collected at 25 deep wells (greater than 125 feet deep) within 1 mile of the shore. The median nitrogen concentration for the shallow and median nitrate concentration for the deep ground water in Nassau County were 3.85 and 0.15 mg/L as N, during 1952–97; the corresponding concentrations for Suffolk County were 1.74 and <0.10 (less than 0.10) mg/L as N, during 1952–97.Nitrogen loads discharged from streams to the SSER for each year during 1972–97 were calculated as the annual total nitrogen concentration multiplied by the annual discharge. These values were calculated only for the seven streams for which sufficient data were available. The largest long-term (1972–97) average annual nitrogen load from Carlls River was 104 ton/yr or 94,300 kg/yr—about twice that of Connetquot River (54 ton/yr or 48,900 kg/yr) and over three times that of Carmans River (33 ton/yr or 29,900 kg/yr). The smallest annual mean nitrogen load was from Pines Brook, which has the lowest annual mean discharge of all streams analyzed.The nitrogen load carried to the SSER by ground-water discharge in shallow-ground-water system in Nassau and Suffolk Counties was calculated as the simulated discharge for each county multiplied by the respective median nitrogen concentration, and loads from deep-ground-water system were calculated as the simulated discharge for each county multiplied by the respective median nitrate concentration. All discharges were obtained from the U.S. Geological Survey's Long Island ground-water-flow model. The resultant nitrogen loads discharged to the SSER from shallow ground water were 172 ton/yr (156,000 kg/yr) from Nassau County and 380 ton/yr (345,000 kg/yr) from Suffolk County; equaling 552 ton/yr entering the SSER. Those from deep ground water were 3 ton/yr (2,700 kg/yr) from Nassau County and <0.5 ton/yr (480 kg/yr) from Suffolk County; equaling about 3.5 ton/yr entering the SSER.The sum of both stream loads and groundwater loads results in the total load to the SSER. The largest calculated total nitrogen load entering the SSER from both streams and ground water occurred in 1979 with a total load of 1,260 ton/yr (1,140,000 kg/yr). The smallest calculated nitrogen load entering the SSER occurred in 1995 with a total load of 725 ton/yr (658,000 kg/yr).

Deep Rivers of Learning

ERIC Educational Resources Information Center

Claxton, Guy

2018-01-01

It's all too easy for teachers to focus on building students' knowledge and skills without paying attention to the mental habits that students need to be effective learners. Guy Claxton discusses the need for teachers to design their instruction in a way that promotes resilience, curiosity, independence, and a positive disposition toward learning.

Comparison of Mount Saint Helens Volcanic Eruption to a Nuclear Explosion.

DTIC Science & Technology

1981-01-01

River to deep-draft ships. The volcano ejected materials for a relatively long period of time--the only tiltmeter that survived the eruption showed...shown because they are not standard microbarograph re- cordings. The sensor includes a high-pass electronic filter so that the output must be

ACCESS America's great outdoors: public lands are for everyone!

Treesearch

Joe Meade; Gregory J. Lais

1995-01-01

With nearly 200 million acres of majestic mountains, deep rugged canyons, pristine high lakes, wild rivers, immense forests, and open meadows, the National Forest System provides the largest variety of outdoor recreation opportunities in the United States. Federal lands encompass a combined total of nearly one-third of this country.

C&S Enterprise, L.L.C. - Clean Water Act Public Notice

EPA Pesticide Factsheets

The EPA is providing notice of a proposed Administrative Penalty Assessment against C & S Enterprise, L.L.C. (“Respondent”), a business located at 2454 480th Ave, Deep River, IA 52222, for alleged violations of the Clean Water Act at property owned by Resp

Comparison. US P-61 and Delft sediment samplers

USGS Publications Warehouse

Beverage, Joseph P.; Williams, David T.

1990-01-01

The Delft Bottle (DB) is a flow-through device designed by the Delft Hydraulic Laboratory (DHL), The Netherlands, to sample sand-sized sediment suspended in streams. The US P-61 sampler was designed by the Federal Interagency Sedimentation Project (FISP) at the St. Anthony Falls Hydraulic Laboratory, Minneapolis, Minnesota, to collect suspended sediment from deep, swift rivers. The results of two point-sampling tests in the United States, the Mississippi River near Vicksburg, Mississippi, in 1983 and the Colorado River near Blythe, California, in 1984, are provided in this report. These studies compare sand-transport rates, rather than total sediment-transport rates, because fine material washes through the DB sampler. In the United States, the commonly used limits for sand-sized material are 0.062 mm to 2.00 mm (Vanoni 1975).

Water-quality and algal conditions in the Clackamas River basin, Oregon, and their relations to land and water management

USGS Publications Warehouse

Carpenter, Kurt D.

2003-01-01

In 1998, the U.S. Geological Survey sampled the Clackamas River, its major tributaries, and reservoirs to characterize basic water quality (nutrients, dissolved oxygen, pH, temperature, and conductance), water quantity (water sources within the basin), and algal conditions (biomass and species composition). Sampling locations reflected the dominant land uses in the basin (forest management, agriculture, and urban development) as well as the influence of hydroelectric projects, to examine how these human influences might be affecting water quality and algal conditions. Nuisance algal growths, with accompanying negative effects on water quality, were observed at several locations in the basin during this study. Algal biomass in the lower Clackamas River reached a maximum of 300 mg/m2 chlorophyll a, producing nuisance algal conditions, including fouled stream channels and daily fluctuations in pH and dissolved oxygen concentrations to levels that did not meet water-quality standards. Algal biomass was highest at sites immediately downstream from the hydroelectric project's reservoirs and/or powerhouses. Nuisance algal conditions also were observed in some of the tributaries, including the North Fork of the Clackamas River, Clear Creek, Rock Creek, and Sieben Creek. High amounts of drifting algae increased turbidity levels in the Clackamas River during June, which coincided with a general increase in the concentration of disinfection by-products found in treated Clackamas River water used for drinking, presumably due to the greater amounts of organic matter in the river. The highest nutrient concentrations were found in the four lowermost tributaries (Deep, Richardson, Rock, and Sieben Creeks), where most of the agriculture and urban development is concentrated. Of these, the greatest load of nutrients came from Deep Creek, which had both high nutrient concentrations and relatively high streamflow. Streams draining forestland in the upper basin (upper Clackamas River and Oak Grove Fork) had the highest concentrations of phosphorus (and lowest concentrations of nitrogen), and streams draining forestland in the middle basin (Clear Creek, Eagle Creek, and the North Fork of the Clackamas River) had relatively high concentrations of nitrogen (and low concentrations of phosphorus). In contrast, relatively low concentrations of both nitrogen and phosphorus were found at the two reference streams, reflecting their pristine condition. Relatively high phosphorus levels in the upper basin are probably due to the erosion of naturally occurring phosphorus deposits in this area. Likely sources of nitrogen (mostly nitrate) in the forested watersheds include nitrogen-fixing plants, atmospheric deposition, timber harvesting, and applications of urea fertilizers.

Summer microhabitat use by adult and young-of-year snail darters (Percina tanasi) in two rivers

USGS Publications Warehouse

Ashton, M.J.; Layzer, J.B.

2010-01-01

We characterised microhabitat availability and use by adult and young-of-year (YOY) snail darters (Percina tanasiEtnier 1976) while snorkelling in the French Broad and Hiwassee rivers, TN, USA. Both age groups of snail darters disproportionately used most microhabitat variables compared to their availability. Snail darters primarily occupied moderately deep, swift water over gravel substrates with little macrophyte coverage and no silt. Univariate comparisons indicated that adult and YOY darters occupied different habitat, but there was no marked differences between principal components analysis plots of multivariate microhabitat use within a river. Although the availability of microhabitat variables differed between the French Broad and Hiwassee rivers, univariate means and multivariate plots illustrated that the habitats used were generally similar by age groups of snail darters between rivers. Because our observations of habitat availability and use were constrained to low flow periods and depths <1 m, the transferability of our results to higher flow periods may be limited. However, the similarity in habitat use between rivers suggests that our results can be applied to low-normal flow conditions in other streams. ?? Published 2010. This article is a US Government work and is in the public domain in the USA.

Movement and habitat use of green sturgeon Acipenser medirostris in the Rogue River, Oregon, USA

USGS Publications Warehouse

Erickson, D.L.; North, J.A.; Hightower, J.E.; Weber, J.; Lauck, L.

2002-01-01

Green sturgeon (Acipenser medirostris) movement patterns and habitat use within the Rogue River, Oregon were evaluated using radio telemetry. Nineteen specimens ranging from 154 to 225 cm total length were caught by gill netting and tagged with radio transmitters during May-July 2000. One tagged green sturgeon was verified as a female near spawning condition. Individual green sturgeons spent more than 6 months in fresh water and traveled as far as river kilometer (rkm) 39.5. Green sturgeon preferred specific holding sites within the Rogue River during summer and autumn months. These sites were typically deep (> 5 m) low-gradient reaches or off-channel coves. Home ranges within holding sites were restricted. All tagged individuals emigrated from the system to the sea during the autumn and winter, when water temperatures dropped below 10??C and flows increased. This species is extremely vulnerable to habitat alterations and overfishing because it spawns in only a few North American rivers and individuals reside within extremely small areas for extended periods of time.

Nutrient removal by up-scaling a hybrid floating treatment bed (HFTB) using plant and periphyton: From laboratory tank to polluted river.

PubMed

Liu, Junzhuo; Wang, Fengwu; Liu, Wei; Tang, Cilai; Wu, Chenxi; Wu, Yonghong

2016-05-01

Planted floating treatment bed (FTB) is an innovative technique of removing nutrients from polluted water but limited in deep water and cold seasons. Periphyton was integrated into FTB for a hybrid floating treatment bed (HFTB) to improve its nutrient removal capacity. To assess its potential for treating nutrient-polluted rivers, HFTB was up-scaled from 5L laboratory tanks to 350L outdoor tanks and then to a commercial-scale 900m section of polluted river. Plants and periphyton interacted in HFTB with periphyton limiting plant root growth and plants having shading effects on periphyton. Non-overlapping distribution of plants and periphyton can minimize the negative interactions in HFTB. HFTB successfully kept TN and TP of the river at less than 2.0 and 0.02mgL(-1), respectively. This study indicates that HFTB can be easily up-scaled for nutrients removal from polluted rivers in different seasons providing a long-term, environmentally-friendly method to remediate polluted ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

The non-monotypic status of the neotropical fish genus Hemiodontichthys (Siluriformes, Loricariidae) evidenced by genetic approaches.

PubMed

Carvalho, Margarida Lima; Costa Silva, Guilherme José da; Melo, Silvana; Ashikaga, Fernando Yuldi; Shimabukuro-Dias, Cristiane Kioko; Scacchetti, Priscilla Cardim; Devidé, Renato; Foresti, Fausto; Oliveira, Claudio

2018-01-31

The combination of cytogenetic and molecular data with those traditionally obtained in areas like systematics and taxonomy created interesting perspectives for the analysis of natural populations under different aspects. In this context, this study aimed to evaluate the genetic differentiation among populations of the genus Hemiodontichthys Bleeker, 1862, through combined genetic techniques and included the analysis of populations sampled in the Araguaia River, Guamá River, Madeira River and two populations from the Purus River. Hemiodontichthys samples from the two localities in Purus River were also karyotyped in order to address the degree of chromosomal variation between populations. Through GMYC analysis of the COI tree, the patterns of genetic variation among local populations revealed to be higher than the ones found among distinct species from other genera of the subfamily Loricariinae, suggesting the existence of probable four cryptic species in this genus. The possible existence of a species complex in the genus is corroborated by the different cytogenetic patterns between Hemiodontichthys sp. 1 and sp. 2, revealing the necessity of a deep taxonomic review of the group.

Are deep-sea ecosystems surrounding Madagascar threatened by land-use or climate change?

NASA Astrophysics Data System (ADS)

Fontanier, Christophe; Mamo, Briony; Toucanne, Samuel; Bayon, Germain; Schmidt, Sabine; Deflandre, Bruno; Dennielou, Bernard; Jouet, Gwenael; Garnier, Eline; Sakai, Saburo; Lamas, Ruth Martinez; Duros, Pauline; Toyofuku, Takashi; Salé, Aurélien; Belleney, Déborah; Bichon, Sabrina; Boissier, Audrey; Chéron, Sandrine; Pitel, Mathilde; Roubi, Angélique; Rovere, Mickaël; Grémare, Antoine; Dupré, Stéphanie; Jorry, Stéphan J.

2018-01-01

In this short communication, we present a multidisciplinary study of sedimentary records collected from a deep-sea interfluve proximal to the mouths of major northwestern Madagascan rivers. For the last 60 years, the seafloor has been repeatedly disturbed by the deposition of organic rich, tropical, terrestrial sediments causing marked reductions in benthic biodiversity. Increased soil erosion due to local land-use, deforestation and intensifying tropical cyclones are potential causes for this sedimentary budget and biodiversity shift. Our marine sedimentary records indicate that until now, these conditions have not occurred within the region for at least 20,000 years.

Revision of the biostratigraphy of the Chatham Group (Upper Triassic), Deep River basin, North Carolina, USA

USGS Publications Warehouse

Litwin, R.J.; Ash, S.R.

1993-01-01

Paleontological evidence from the Upper Triassic Chatham Group in the three subbasins of the Deep River basin (North Carolina, USA) supports a significant revision of the ages assigned to most of this non-marine continental sedimentary sequence. This study confirms an early(?) or mid-Carnian age in the Sanford subbasin for the base of the Pekin Formation, the lowest unit of the Chatham Group. However, diagnostic late Carnian palynomorphs have been recovered from coals in the lower part of the Cumnock Formation in the Sanford subbasin, and from a sample of the Cumnock Formation equivalent in the Wadesboro subbasin. Plant megafossils and fossil verebrates from rocks in the Sanford subbasin also support a late Carnian age for the Cumnock Formation and its equivalents. The overlying Sanford Formation, which has not yet been dated paleontologically, probably includes beds of Norian age, as over 1000 m of strata may be present between the Cumnock Formation coals (dated here as late Carnian) and the top of the Sanford Formation. This chronostratigraphic interval appears similar to, but slightly longer than, that preserved in the Dan River-Danville and Davie County basins 100 km to the northwest. Our evidence, therefore, indicates that the Chatham Group was deposited over a much longer time interval [early(?) to mid-Carnian through early Norian] than previously was believed. ?? 1993.

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

S. J. Payne; J. M. Hodges; R. G. Berg

During 2011, the Idaho National Laboratory Seismic Monitoring Program evaluated 21,928 independent triggers that included earthquakes from around the world, the western United States, and local region of the Snake River Plain. Seismologists located 2,063 earthquakes and man-made blasts within and near the 161-km (or 100-mile) radius of the Idaho National Laboratory. Of these events, 16 were small-to-moderate size earthquakes ranging in magnitude (M) from 3.0 to 4.4. Within the 161-km radius, the majority of 941 earthquakes (M < 4.4) occurred in the active regions of the Basin and Range Province with only six microearthquakes occurring in the Snake Rivermore » Plain. In the northern and southeastern Basin and Range, eight earthquake swarms occurred and included over 325 events. Five of the Snake River Plain earthquakes were located within and near the northern and southern ends of the Great Rift volcanic rift zone. All have anomalously deep focal depths (16 to 38 km) and waveforms indicative of fluid movement at mid- and lower-crustal levels and are a continuation of activity observed at Craters of the Moon National Monument since 2007. Since 1972, the Idaho National Laboratory has recorded 55 small-magnitude microearthquakes (M = 2.2) within the eastern Snake River Plain and 25 deep microearthquakes (M = 2.3) in the vicinity of Craters of the Moon National Monument.« less

Importance of lateral flux and its percolation depth on organic carbon export in Arctic tundra soil: Implications from a soil leaching experiment

NASA Astrophysics Data System (ADS)

Zhang, Xiaowen; Hutchings, Jack A.; Bianchi, Thomas S.; Liu, Yina; Arellano, Ana R.; Schuur, Edward A. G.

2017-04-01

Temperature rise in the Arctic is causing deepening of active layers and resulting in the mobilization of deep permafrost dissolved organic matter (DOM). However, the mechanisms of DOM mobilization from Arctic soils, especially upper soil horizons which are drained most frequently through a year, are poorly understood. Here we conducted a short-term leaching experiment on surface and deep organic active layer soils, from the Yukon River basin, to examine the effects of DOM transport on bulk and molecular characteristics. Our data showed a net release of DOM from surface soils equal to an average of 5% of soil carbon. Conversely, deep soils percolated with surface leachates retained up to 27% of bulk DOM while releasing fluorescent components (up to 107%), indicating selective release of aromatic components (e.g., lignin and tannin), while retaining nonchromophoric components, as supported by spectrofluorometric and ultrahigh-resolution mass spectroscopic techniques. Our findings highlight the importance of the lateral flux of DOM on ecosystem carbon balance as well as processing of DOM transport through organic active layer soils en route to rivers and streams. This work also suggests the potential role of leachate export as an important mechanism of C losses from Arctic soils, in comparison with the more traditional pathway from soil to atmosphere in a warming Arctic.

Spatiotemporal distribution and fluctuation of radiocesium in Tokyo Bay in the five years following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident

PubMed Central

Yamazaki, Hideo; Hinokio, Ryoichi; Yamashiki, Yosuke Alexandre; Azuma, Ryokei

2018-01-01

A monitoring survey was conducted from August 2011 to July 2016 of the spatiotemporal distribution in the 400 km2 area of the northern part of Tokyo Bay and in rivers flowing into it of radiocesium released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. The average inventory in the river mouth (10 km2) was 131 kBq⋅m-2 and 0.73 kBq⋅m-2 in the central bay (330 km2) as the decay corrected value on March 16, 2011. Most of the radiocesium that flowed into Tokyo Bay originated in the northeastern section of the Tokyo metropolitan area, where the highest precipitation zone of 137Cs in soil was almost the same level as that in Fukushima City, then flowed into and was deposited in the Old-Edogawa River estuary, deep in Tokyo Bay. The highest precipitation of radiocesium measured in the high contaminated zone was 460 kBq⋅m-2. The inventory in sediment off the estuary of Old-Edogawa was 20.1 kBq⋅m-2 in August 2011 immediately after the accident, but it increased to 104 kBq⋅m-2 in July 2016. However, the radiocesium diffused minimally in sediments in the central area of Tokyo Bay in the five years following the FDNPP accident. The flux of radiocesium off the estuary decreased slightly immediately after the accident and conformed almost exactly to the values predicted based on its radioactive decay. Contrarily, the inventory of radiocesium in the sediment has increased. It was estimated that of the 8.33 TBq precipitated from the atmosphere in the catchment regions of the rivers Edogawa and Old-Edogawa, 1.31 TBq migrated through rivers and was deposited in the sediments of the Old-Edogawa estuary by July 2016. Currently, 0.25 TBq⋅yr-1 of radiocesium continues to flow into the deep parts of Tokyo Bay. PMID:29494667

The sedimentary record of Carboniferous rivers: Continuing influence of land plant evolution on alluvial processes and Palaeozoic ecosystems

NASA Astrophysics Data System (ADS)

Davies, Neil S.; Gibling, Martin R.

2013-05-01

Evidence from modern rivers and the deep-time geological record attests to the fundamental importance of plant life for the construction of physical habitats within fluvial environments. Data from an extensive literature review and original fieldwork demonstrates that many landforms and geomorphic features of modern river systems appear in the Palaeozoic stratigraphic record once terrestrial vegetation had adopted certain evolutionary advances. For example, stable point bars are associated with the onset of rooted plants in the Siluro-Devonian and avulsive and anabranching fluvial systems become common at the same time as extensive arborescent vegetation in the Carboniferous. In this paper, we demonstrate a correlation between the diversification of physical fluvial environments and the expansion of terrestrial fauna and flora, with an emphasis on the culmination of these trends within Carboniferous alluvial systems. Many extrinsic factors have been considered as possible controls on the evolutionary timelines of terrestrialization for organisms. However, a fundamental prerequisite for achieving terrestrial biodiversity was the variety of physical habitats, especially riparian systems, available for newly evolved organisms. In association with abundant lowland meandering systems, the widespread appearance across Carboniferous alluvial plains of fixed-channel and anabranching reaches created further physical landforms for colonization and would have promoted increasingly complex hyporheic flow regimes. Furthermore the associated increase in arborescent vegetation and supply of large woody debris to inland and coastal rivers would have created a wealth of microhabitats for continental organisms. We argue that the expanding extent and diversity of physical alluvial niches during the Palaeozoic is an underappreciated driver of the terrestrialization of early continental life. The study of the deep-time fossil and stratigraphic record also illustrates that vegetation is a fundamental prerequisite for the creation of biogeomorphic alluvial landforms and physical habitats and microhabitats.

Accumulation of artificial radionuclides in deep sediments of the Mediterranean Sea

NASA Astrophysics Data System (ADS)

Garcia-Orellana, J.; Sanchez-Cabeza, J. A.; Masque, P.; Costa, E.; Bruach, J. M.; Morist, A.; Luna, J. A.

2003-04-01

Concentrations and inventories of artificial radionuclides (90Sr, 137Cs and 239,40Pu) were determined in deep sediment cores (3.000 m) collected in the western and eastern basins of the Mediterranean Sea in the frame of the ADIOS project. Artificial radionuclides enter the Mediterranean Sea mainly though atmospheric deposition after nuclear weapons tests and the Chernobyl accident, but also through the river discharge of effluents of nuclear facilities (e.g. Rhone and Ebro rivers). The aim of this work is to investigate the degree by which pollutants are transferred to the deep environment of the Mediterranean Sea as a basis to elucidate their effects on benthic organisms. The mean inventories of 239+240Pu, 137Cs and 90Sr in the Western basin are 2.77 ± 0.26, 68 ± 12 and < 7 Bq\\cdotm-2 respectively and 3.29 ± 0.60, 115 ± 33 and 249±154 Bq\\cdotm-2 in the Eastern basin. The activity - depth profiles of 210Pb, together with 14C dating, indicate that sediment mixing redistributes the artificial radionuclides within the first 2 cm of the sedimentary column. Artificial radionuclides inventories in the deep-sea sediments were used to calculate the fraction of the total inventory of artificial radionuclides that is accumulated in the deep sea sediments after scavenging from the water column. Indeed, a balance of the radionuclide distributions in the water column allows evaluating the importance of lateral transport of particulate matter from the continental margins on the accumulation of artificial radionuclides in the deep, open Mediterranean Sea. This is achieved in i) comparison with reported data from coastal areas at different locations in the Mediterranean Sea, and ii) balance of the distribution of the natural radionuclide 210Pb in studied areas (vertical profiles of dissolved and particulate activities, fluxes determined by using sediment trap deployed at different depths and inventories in the bottom sediments). The results, taking into account radioactive decay and exchange fluxes through the Gibraltar Strait, permit to estimate the residence times of pollutants in the water column and predict future evolution of their distributions.

Relations Among River Stage, Rainfall, Ground-Water Levels, and Stage at Two Missouri River Flood-Plain Wetlands

USGS Publications Warehouse

Kelly, Brian P.

2001-01-01

The source of water is important to the ecological function of Missouri River flood-plain wetlands. There are four potential sources of water to flood-plain wetlands: direct flow from the river channel during high river stage, ground-water movement into the wetlands in response to river-stage changes and aquifer recharge, direct precipitation, and runoff from surrounding uplands. Concurrent measurements of river stage, rainfall, ground-water level, and wetland stage were compared for two Missouri River flood-plain wetlands located near Rocheport, Missouri, to characterize the spatial and temporal relations between river stage, rainfall, ground-water levels and wetland stage, determine the source of water to each wetland, and compare measured and estimated stage and ground-water levels at each site. The two sites chosen for this study were wetland NC-5, a non-connected, 50 feet deep scour constantly filled with water, formed during the flood of 1993, and wetland TC-1, a shallow, temporary wetland intermittently filled with water. Because these two wetlands bracket a range of wetland types of the Missouri River flood plain, the responses of other Missouri River wetlands to changes in river stage, rainfall, and runoff should be similar to the responses exhibited by wetlands NC-5 and TC-1. For wetlands deep enough to intersect the ground-water table in the alluvial aquifer, such as wetland NC-5, the ground-water response factor can estimate flood-plain wetland stage changes in response to known river-stage changes. Measured maximum stage and ground-water-level changes at NC-5 fall within the range of estimated changes using the ground-water response factor. Measured maximum ground-water-level changes at TC-1 are similar to, but consistently greater than the estimated values, and are most likely the result of alluvial deposits with higher than average hydraulic conductivity located between wetland TC-1 and the Missouri River. Similarity between ground-water level and stage hydrography at wetland NC-5 indicate that ground-water-level fluctuations caused by river-stage changes control the stage of wetland NC-5. A 2-day lag time exists between river-stage changes and ground water and stage changes at wetland NC-5. The lack of a measurable response of wetland NC-5 stage to rainfall indicate that rainfall is not a large source of water to wetland NC-5. Stage in wetland TC-1 only increased at high river stage in June and July 1999, and from runoff caused by local rainfall during the winter. The 2-day lag time between peak stages at wetland TC-1 and peak Missouri River stages compared to the 1-day lag time between Missouri River stage and ground-water peaks at wetland TC-1 indicates ground-water flow does not directly affect wetland stage at TC-1, but surface-water flow does affect wetland stage at TC-1 during high river stage. Comparing wetland TC-1 stage to potential water sources indicates the most likely explanation for the rise in stage at wetland TC-1 is surface runoff supplied via seepage through the levees and upward flow of ground water through alluvial deposits of higher hydraulic conductivity during high river stage. The rate of decrease in wetland TC-1 stage was limited by the rate at which ground-water level decreased. Stage response to rainfall at wetland TC-1 during the winter months and no response to greater rainfall amounts during spring and summer months indicate that evapotranspiration may limit the affect of rainfall on stage at wetland TC-1 during the growing season.

Biogeographic, cultural, and historical setting [Chapter 2

Treesearch

Hanna K. Olson; Don W. Fallon

2018-01-01

The Intermountain Adaptation Partnership (IAP) encompasses unique landscapes within the Intermountain Region of the U.S. Forest Service (USFS), from rugged mountains to deep canyons, from alpine snowfields to wild and scenic rivers (fig. 1.1). The area defined by the boundaries of the Intermountain Region contains both private and Federally owned lands, including 12...

Performance of gypsy moth larvae on hosts from the Deep South: survival, development and host preferences

Treesearch

C. Wayne Berisford; Todd J. Lanigan; Michael E. Montgomery

1991-01-01

Survival, development time and pupal weights of gypsy moth, Lymantria dispar L., which had fed on southern tree hosts were determined. Five species of oaks, Quercus spp.; sweetgum, Liquidambar styracflua L.; and river birch, Betula nigra L., were found to be acceptable hosts. Survival and...

Ethiopians. Refugee Fact Sheet Series #1.

ERIC Educational Resources Information Center

Center for Applied Linguistics, Washington, DC. Language and Orientation Resource Center.

Hundreds of thousands of Ethiopians have been forced to flee their country by a repressive regime, a civil war, and an international conflict. These people inhabited a highland plateau cut by deep river valleys and bordered by seas, deserts, and jungles. Ethiopians have diverse backgrounds and speak many languages. Through their long history they…

Geochemical and statistical evidence of recharge, mixing, and controls on spring discharge in an eogenetic karst aquifer

NASA Astrophysics Data System (ADS)

Moore, Paul J.; Martin, Jonathan B.; Screaton, Elizabeth J.

2009-10-01

SummaryInformation about sources of recharge, distributions of flow paths, and the extent of water-rock reactions in karst aquifers commonly result from monitoring spring chemistry and discharge. To investigate the relationship between spring characteristics and the complexities of karst aquifers, we couple variations in surface- and groundwater chemistry to physical conditions including river stage, precipitation, and evapotranspiration (ET) within a sink-rise system through a 6-km portion of the Upper Floridan aquifer (UFA) in north-central Florida. Principal component analysis (PCA) of time series major-element compositions suggests that at least three sources of water affect spring discharge, including allogenic recharge into a swallet, diffuse recharge through a thin vadose zone, and water upwelling from deep within the aquifer. The deep-water source exerts the strongest influence on water chemistry by providing a majority of Na +, Mg 2+, K +, Cl -, and SO42- to the system. Anomalously high temperature at one of several monitoring wells reflects vertical flow of about 1 m/year. Mass-balance calculations suggest diffuse recharge and deep-water upwelling can provide up to 50% of the spring discharge; however, their contributions depend on head gradients between the conduit and surrounding aquifer matrix, which are influenced by variations in precipitation, ET, and river stage. Our results indicate that upwelling from deep flow paths may provide significant contributions of water to spring discharge, and that monitoring only springs limits interpretations of karst systems by masking critical components of the aquifer, such as water sources and flow paths. These results also suggest the matrix in eogenetic aquifers is a major pathway for flow even in a system dominated by conduits.

Recent paleoseismicity record in Prince William Sound, Alaska, USA

NASA Astrophysics Data System (ADS)

Kuehl, Steven A.; Miller, Eric J.; Marshall, Nicole R.; Dellapenna, Timothy M.

2017-12-01

Sedimentological and geochemical investigation of sediment cores collected in the deep (>400 m) central basin of Prince William Sound, along with geochemical fingerprinting of sediment source areas, are used to identify earthquake-generated sediment gravity flows. Prince William Sound receives sediment from two distinct sources: from offshore (primarily Copper River) through Hinchinbrook Inlet, and from sources within the Sound (primarily Columbia Glacier). These sources are found to have diagnostic elemental ratios indicative of provenance; Copper River Basin sediments were significantly higher in Sr/Pb and Cu/Pb, whereas Prince William Sound sediments were significantly higher in K/Ca and Rb/Sr. Within the past century, sediment gravity flows deposited within the deep central channel of Prince William Sound have robust geochemical (provenance) signatures that can be correlated with known moderate to large earthquakes in the region. Given the thick Holocene sequence in the Sound ( 200 m) and correspondingly high sedimentation rates (>1 cm year-1), this relationship suggests that sediments within the central basin of Prince William Sound may contain an extraordinary high-resolution record of paleoseismicity in the region.

Delineation of spatial-temporal patterns of groundwater/surface-water interaction along a river reach (Aa River, Belgium) with transient thermal modeling

NASA Astrophysics Data System (ADS)

Anibas, Christian; Tolche, Abebe Debele; Ghysels, Gert; Nossent, Jiri; Schneidewind, Uwe; Huysmans, Marijke; Batelaan, Okke

2018-05-01

Among the advances made in analytical and numerical analysis methods to quantify groundwater/surface-water interaction, one methodology that stands out is the use of heat as an environmental tracer. A large data set of river and riverbed temperature profiles from the Aa River in Belgium has been used to examine the spatial-temporal variations of groundwater/surface-water interaction. Exchange fluxes were calculated with the numerical heat-transport code STRIVE. The code was applied in transient mode to overcome previous limitations of steady-state analysis, and allowed for the calculation of model quality. In autumn and winter the mean exchange fluxes reached -90 mm d-1, while in spring and early summer fluxes were -42 mm d-1. Predominantly gaining conditions occurred along the river reach; however, in a few areas the direction of flow changed in time. The river banks showed elevated fluxes up to a factor of 3 compared to the center of the river. Higher fluxes were detected in the upstream section of the reach. Due to the influence of exchange fluxes along the river banks, larger temporal variations were found in the downstream section. The exchange fluxes at the river banks seemed more driven by variable local exchange flows, while the center of the river was dominated by deep and steady regional groundwater flows. These spatial and temporal differences in groundwater/surface-water exchange show the importance of long-term investigations on the driving forces of hyporheic processes across different scales.

BLAM (Benthic Light Availability Model): A Proposed Model of Hydrogeomorphic Controls on Light in Rivers

NASA Astrophysics Data System (ADS)

Julian, J. P.; Doyle, M. W.; Stanley, E. H.

2006-12-01

Light is vital to the dynamics of aquatic ecosystems. It drives photosynthesis and photochemical reactions, affects thermal structure, and influences behavior of aquatic biota. Despite the fundamental role of light to riverine ecosystems, light studies in rivers have been mostly neglected because i) boundary conditions (e.g., banks, riparian vegetation) make ambient light measurements difficult, and ii) the optical water quality of rivers is highly variable and difficult to characterize. We propose a benthic light availability model (BLAM) that predicts the percent of incoming photosynthetically active radiation (PAR) available at the river bed. BLAM was developed by quantifying light attenuation of the five hydrogeomorphic controls that dictate riverine light availability: topography, riparian vegetation, channel geometry, optical water quality, and water depth. BLAM was calibrated using hydrogeomorphic data and light measurements from two rivers: Deep River - a 5th-order, turbid river in central North Carolina, and Big Spring Creek - a 2nd-order, optically clear stream in central Wisconsin. We used a series of four PAR sensors to measure i) above-canopy PAR, ii) PAR above water surface, iii) PAR below water surface, and iv) PAR on stream bed. These measurements were used to develop empirical light attenuation coefficients, which were then used in combination with optical water quality measurements, shading analyses, channel surveys, and flow records to quantify the spatial and temporal variability in riverine light availability. Finally, we apply BLAM to the Baraboo River - a 6th-order, 120-mile, unimpounded river in central Wisconsin - in order to characterize light availability along the river continuum (from headwaters to mouth).

Potentiometric surface map of the Floridan Aquifer in the St Johns River Water Management District and vicinity, Florida, September, 1977

USGS Publications Warehouse

Watkins, F.A.; Laughlin, C.P.; Hayes, E.C.

1977-01-01

This map presents the potentiometric surface of the Floridan aquifer in the St. Johns River Water Management District and vicinity for September 1977. The Floridan aquifer is the principal source of potable water in the area. Water-level measurements were made on approximately 900 wells and springs. The potentiometric surface is shown by 5-foot contours except in the Fernandina Beach area where 10- and 20-foot contours are used to show the deep cone of depression. This is the first map covering the entire St. Johns River Water Management District and vicinity for September, a high water-level period. The potentiometric surface ranged from 130 feet above mean sea level in Polk County to 131 feet below sea level in Nassau County. (Woodard-USGS)

Tackling the Challenge of Deep Vadose Zone Remediation at the Hanford Site

NASA Astrophysics Data System (ADS)

Morse, J. G.; Wellman, D. M.; Gephart, R.

2010-12-01

The Central Plateau of the Hanford Site in Washington State contains some 800 waste disposal sites where 1.7 trillion liters of contaminated water was once discharged into the subsurface. Most of these sites received liquids from the chemical reprocessing of spent uranium fuel to recover plutonium. In addition, 67 single shell tanks have leaked or are suspected to have leaked 3.8 million liters of high alkali and aluminate rich cesium-contaminated liquids into the sediment. Today, this inventory of subsurface contamination contains an estimated 550,000 curies of radioactivity and 150 million kg (165,000 tons) of metals and hazardous chemicals. Radionuclides range from mobile 99Tc to more immobilized 137Cs, 241Am, uranium, and plutonium. A significant fraction of these contaminants likely remain within the deep vadose zone. Plumes of groundwater containing tritium, nitrate, 129I and other contaminants have migrated through the vadose zone and now extend outward from the Central Plateau to the Columbia River. During most of Hanford Site history, subsurface studies focused on groundwater monitoring and characterization to support waste management decisions. Deep vadose zone studies were not a priority because waste practices relied upon that zone to buffer contaminant releases into the underlying aquifer. Remediation of the deep vadose zone is now central to Hanford Site cleanup because these sediments can provide an ongoing source of contamination to the aquifer and therefore to the Columbia River. However, characterization and remediation of the deep vadose zone pose some unique challenges. These include sediment thickness; contaminant depth; coupled geohydrologic, geochemical, and microbial processes controlling contaminant spread; limited availability and effectiveness of traditional characterization tools and cleanup remedies; and predicting contaminant behavior and remediation performance over long time periods and across molecular to field scales. The U.S Department of Energy recognizes these challenges and is committed to a sustained, focused effort of continuing to apply existing technologies where feasible while investing and developing in new innovative, field-demonstrated capabilities supporting longer-term basic and applied research to establish the technical underpinning for solving intractable deep vadose zone problems and implementing final remedies. This approach will rely upon Multi-Project Teams focusing on coordinated projects across multiple DOE offices, programs, and site contractors plus the facilitation of basic and applied research investments through implementing a Deep Vadose Zone Applied Field Research Center and other scientific studies.

Geologic map of the Weldona 7.5' quadrangle, Morgan County, Colorado

USGS Publications Warehouse

Berry, Margaret E.; Taylor, Emily M.; Slate, Janet L.; Paces, James B.; Hanson, Paul R.; Brandt, Theodore R.

2018-03-21

The Weldona 7.5′ quadrangle is located on the semiarid plains of northeastern Colorado, along the South Platte River corridor where the river has incised into Upper Cretaceous Pierre Shale. The Pierre Shale is largely covered by surficial deposits that formed from alluvial, eolian, and hillslope processes operating in concert with environmental changes from the Pleistocene to the present. The South Platte River, originating high in the Colorado Rocky Mountains, has played a major role in shaping surficial geology in the map area, which is several tens of kilometers downstream from where headwater tributaries join the river. Recurrent glaciation (and deglaciation) of basin headwaters has affected river discharge and sediment supply far downstream, influencing deposition of alluvium and river incision in the Weldona quadrangle. During the Pleistocene the course of the river within the map area shifted progressively southward as it incised, and by late middle Pleistocene the river was south of its present position, cutting and filling deep paleochannels now covered by younger alluvium. The river shifted back to the north during the late Pleistocene. Kiowa and Bijou Creeks are unglaciated tributaries originating in the Colorado Piedmont east of the Front Range that also have played a major role in shaping surficial geology of the map area. Periodically during the late Pleistocene, major flood events on these tributaries deposited large volumes of sediment at their confluences, forming a broad, low-gradient fan of sidestream alluvium that could have occasionally dammed the river for short periods of time. Eolian sand deposits of the Sterling (north of river) and Fort Morgan (south of river) dune fields cover much of the quadrangle and record past episodes of sand mobilization during times of prolonged drought. With the onset of irrigation and damming during historical times, the South Platte River has changed from a broad, shallow, and sandy braided river with highly variable seasonal discharge to a much narrower, deeper river with braided-meandering transition morphology and more uniform discharge.

Catchment controls on water temperature and the development of simple metrics to inform riparian zone management

NASA Astrophysics Data System (ADS)

Johnson, Matthew; Wilby, Robert

2015-04-01

Water temperature is a key water quality parameter and is critical to aquatic life Therefore, rising temperatures due to climate and environmental change will have major consequences for river biota. As such, it is important to understand the environmental controls of the thermal regime of rivers. The Loughborough University TEmperature Network (LUTEN) consists of a distributed network of 25 sites along 40 km of two rivers in the English Peak District, from their source to confluence. As a result, the network covers a range of hydrological, sedimentary, geomorphic and land-use conditions. At each site, air and water temperature have been recorded at a 15-minute resolution for over 4 years. Water temperature is spatially patchy and temporally variable in the monitored rivers. For example, the annual temperature range at Beresford Dale is over 18° C, whereas 8 km downstream it is less than 8° C. This heterogeneity leads to some sites being more vulnerable to future warming than others. The sensitivity of sites to climate was quantified by comparing the parameters of logistic regression models, constructed at each site, that relate water temperature to air temperature. These analyses, coupled with catchment modelling suggest that reaches that are surface-water dominated with minimal shade and relatively low water volumes are most susceptible to warming. Such reaches tended to occur at intermediate distances from rivers source in the monitored catchments. Reaches that were groundwater dominated had relatively stable thermal regimes, which were relatively unaffected by inter-annual changes in climatic conditions. Such areas could provide important thermal refuge to many organisms, which is supported by monitoring of the invertebrate community in the catchment. The phenology (i.e. timing of life events) of some species remained consistent between years in a river reach with a stable thermal regime, but changed markedly in other areas of the river. Consequently, areas of thermal refuge could be important in the context of future climate change, potentially maintaining populations of animals excluded from other parts of the river during hot summer months. International management strategies to mitigate rising temperatures tend to focus on the protection, enhancement or creation of riparian shade. Simple metrics derived from catchment landscape models, the heat capacity of water, and modelled solar radiation receipt, suggest that approximately 1 km of deep riparian shading is necessary to offset a 1° C rise in temperature in the monitored catchments. A similar value is likely to be obtained for similar sized rivers at similar latitudes. Trees would take 20 years to attain sufficient height to shade the necessary solar angles. However, 1 km of deep riparian shade will have substantial impacts on the hydrological and geomorphological functioning of the river, beyond simply altering the thermal regime. Consequently, successful management of rising water temperature in rivers will require catchment scale consideration, as part of an integrated management plan.

Contrasting genomic properties of free-living and particle-attached microbial assemblages within a coastal ecosystem

PubMed Central

Smith, Maria W.; Zeigler Allen, Lisa; Allen, Andrew E.; Herfort, Lydie; Simon, Holly M.

2013-01-01

The Columbia River (CR) is a powerful economic and environmental driver in the US Pacific Northwest. Microbial communities in the water column were analyzed from four diverse habitats: (1) an estuarine turbidity maximum (ETM), (2) a chlorophyll maximum of the river plume, (3) an upwelling-associated hypoxic zone, and (4) the deep ocean bottom. Three size fractions, 0.1–0.8, 0.8–3, and 3–200 μm were collected for each habitat in August 2007, and used for DNA isolation and 454 sequencing, resulting in 12 metagenomes of >5 million reads (>1.6 Gbp). To characterize the dominant microorganisms and metabolisms contributing to coastal biogeochemistry, we used predicted peptide and rRNA data. The 3- and 0.8-μm metagenomes, representing particulate fractions, were taxonomically diverse across habitats. The 3-μm size fractions contained a high abundance of eukaryota with diatoms dominating the hypoxic water and plume, while cryptophytes were more abundant in the ETM. The 0.1-μm metagenomes represented mainly free-living bacteria and archaea. The most abundant archaeal hits were observed in the deep ocean and hypoxic water (19% of prokaryotic peptides in the 0.1-μm metagenomes), and were homologous to Nitrosopumilus maritimus (ammonia-oxidizing Thaumarchaeota). Bacteria dominated metagenomes of all samples. In the euphotic zone (estuary, plume and hypoxic ocean), the most abundant bacterial taxa (≥40% of prokaryotic peptides) represented aerobic photoheterotrophs. In contrast, the low-oxygen, deep water metagenome was enriched with sequences for strict and facultative anaerobes. Interestingly, many of the same anaerobic bacterial families were enriched in the 3-μm size fraction of the ETM (2–10X more abundant relative to the 0.1-μm metagenome), indicating possible formation of anoxic microniches within particles. Results from this study provide a metagenome perspective on ecosystem-scale metabolism in an upwelling-influenced river-dominated coastal margin. PMID:23750156

Geology and ground-water hydrology of the Mokelumne area, California

USGS Publications Warehouse

Piper, A.M.; Gale, H.S.; Thomas, H.E.; Robinson, T.W.

1939-01-01

29), and there have been as many as 2,500 wells equipped with irrigation pumping plants (1931). Commonly the wells are pumped only in daylight and are idle over week-ends and holidays, also during and after protracted rainstorms in the early part of the season. In a small district near Victor pumping in recent years has begun in January or February, has reached its height in March, and largely has passed by April. In outlying districts general pumping has begun as late as May, reached its height in June or July, and waned by September. Since 1907 the water table appears to have declined steadily in most of the Mokelumne area except along the river. The decline was least in the Woodbridge Irrigation District, where in four typical wells. the average decline from 1907 to 1937 was 3 feet, or 0.15 foot a year. Among 18 shallow wells in the district of most intensive pumping the average recession of the water table from 1907 to 1927 was 11 feet, or 0.55 foot a year; the greatest measured recession was 15 feet, or 0.75 foot a year. From 1927 to 1933 the water table declined 5 feet or more over most of the central pumping district except within 2 miles of the Mokelumne River, and the greatest measured decline was 9 feet. The area of material recession ,extends 4 to 7 miles eastward beyond the central pumping district, whence it is inferred that pumping has drawn gradually on remote ground-water storage. It is inferred that the Mokelumne River ordinarily has been a losing stream between the Mehrten dam site, near Clements, and the Woodbridge Dam, the area that received the percolate having been triangular with its upstream and having included about 5,200 acres of the flood plain and 36,500 acres in outlying districts to the north and to the south. Mean fluctuations of the water table within the area receiving percolate from ihe river are believed to indicate that relatively little water is drawn from outside the area. Accordingly, simple storage methods are competent for a ground-water inventory. It is inferred that the rate of seepage loss from the river depends jointly upon river discharge, stage in the Woodbridge Reservoir, and groundwater pumpage. The foregoing inferences lead to the following conclusions with respect to ground-water replenishment by seepage loss from the river in the intensively cultivated district about Lodi: (1) The annual replenishment has tended to increase for at least two decades, owing to the gradual increase in head between surface water and ground water as ground-water levels have been lowered progressively by pumping; (2) annual replenishment has tended to increase, especially in recent years, owing to gradually prolonged use of the Woodbridge Reservoir, for thereby a relatively large wetted area and great differential head have been maintained for an increasing term; (3) the rate of replenishment tends to be greater under regulation than under the so-called natural regimen, to the extent that regulation has maintained a moderately large wetted area and stage in the river through the later part ·of each pumping season, whi1e the ground-water levels have been lowest. Moreover, for any particular yearly run-off below the Mehrten dam site, the replenishment by seepage would tend to be greater under the regulated regimen to the extent that fluctuations in discharge were suppressed, for the greatest yearly mean stage and mean wetted area would be afforded by constant discharge. -Thus, diverting water out of the Mokelumne River Basin at the Pardee Dam does not necessari1y-entail a diminution in ground-water replenishment by seepage loss along the lower reach of the stream, at least in the replenishment beneath the Victor plain above the gaging station at Woodbridge. Rather. the Pardee Dam affords a means for so regulating the discharge as to effect a maximum ground-water replenishment with-a given run-off in the natural channel. Bodies of ground water perched above the regional water table are common in the Laguna formation, especially in its lower part. Conspicuous bodies occur about 3 miles south of Clay, in a district between 1 mile and 5 miles south of Clements, and along Dry Creek in T. 5 N., Rs. 7 and 8 E. From the relation between the water table and the piezometric surface for water confined in deep aquifers, the area receiving percolate from the Mokelumne River may be divided roughly into (1) a central area, extending not :p1ore than half a mi1e beyond the flood plain, in which the piezometric surface is inferred to have stood below the water table throughout the term of the investigation and hence in which the difference in head has favored the percolation of water from shallow beds into deep beds in all seasons, and (2) an outlying area in which the difference in head likewise favors downward percolation into deep beds during the pumping season but favors upward percolation during the nonpumping season. This outlying area includes about 75 percent of the segment of the Victor plain that receives percolate from the river. From 1927 to 1933 the subartesian head that existed during the nonpumping season in the area remote from the river tended to increase; it is therefore inferred that the relative opportunity for seasonal recharge of the shallow water-bearing beds by underfeeding has likewise tended to increase. On the other hand, the negative differential head in wells near the river also has tended to increase; thus in this central area the opportunity for discharge of water from shallow beds by downward percolation has probably tended to increase. It is believed that ground-water storage within the area near the river is not decreased materially by" discharge westward through deep pervious beds, also that the yearly addition to ground-water storage in the outlying area by deep percolation from a remote easterly source is scant and for all practical purposes is offset by downward percolation along the river.

Survival of cyanobacteria in rivers following their release in water from large headwater reservoirs.

PubMed

Williamson, Nicholas; Kobayashi, Tsuyoshi; Outhet, David; Bowling, Lee C

2018-05-01

Cyanobacterial survival following their release in water from major headwaters reservoirs was compared in five New South Wales rivers. Under low flow conditions, cyanobacterial presence disappeared rapidly with distance downstream in the Cudgegong and Hunter Rivers, whereas the other three rivers were contaminated for at least 300 km. Cyanobacterial survival is likely to be impacted by the geomorphology of each river, especially the extent of gravel riffle reaches (cells striking rocks can destroy them) and by the different turbulent flow conditions it produces within each. Flow conditions at gauging stations were used to estimate the turbulent strain rate experienced by suspended cyanobacteria. These indicate average turbulent strain rates in the Cudgegong and Hunter Rivers can be above 33 and 83 s -1 while for the Murray, Edward and Macquarie Rivers average strain rate was estimated to be less than 30 s -1 . These turbulent strain rate estimates are substantially above published thresholds of approximately 2 s -1 for impacts indicated from laboratory tests. Estimates of strain rate were correlated with changes in cyanobacterial biovolume at stations along the rivers. These measurements indicate a weak but significant negative linear relationship between average strain rate and change in cyanobacterial biomass. River management often involves releasing cold deep water with low cyanobacterial presence from these reservoirs, leading to ecological impacts from cold water pollution downstream. The pollution may be avoided if cyanobacteria die off rapidly downstream of the reservoir, allowing surface water to be released instead. However high concentrations of soluble cyanotoxins may remain even after the cyanobacterial cells have been destroyed. The geomorphology of the river (length of riffle reaches) is an important consideration for river management during cyanobacterial blooms in headwater reservoirs. Copyright © 2018 Elsevier B.V. All rights reserved.

Uele River, Cleared Pasture Lands, Zaire, Africa

NASA Image and Video Library

1992-05-16

STS049-91-079 (7 - 16 May 1992) --- This 70mm frame, photographed from the Earth-orbiting Space Shuttle Endeavour, features a dendritic drainage pattern in Zaire. Cleared pasture land shows light green in this color photograph, in contrast to the dark, closed-canopy forest of Zaire. Remnant woodland along minor streams indicates the intricate drainage network of this hilly region. Scattered vegetation-free spots show the deep red, tropical soil of the region. The sediment-laden stream is the Vele River just west of the village of Niangara. A crew member used a 70mm handheld Hasselblad camera with a 250mm lens to record the image.

Channel morphology and its impact on flood passage, the Tianjiazhen reach of the middle Yangtze River

NASA Astrophysics Data System (ADS)

Shi, Yafeng; Zhang, Qiang; Chen, Zhongyuan; Jiang, Tong; Wu, Jinglu

2007-03-01

The Tianjiazhen reach of the middle Yangtze is about 8 km long, and characterized by a narrow river width of 650 m and local water depth of > 90 m in deep inner troughs, of which about 60 m is below the mean sea level. The troughs in the channel of such a large river are associated with regional tectonics and local lithology. The channel configuration plays a critical role in modifying the height and duration of river floods and erosion of the riverbed. The formation of the troughs in the bed of the Yangtze is considered to be controlled by sets of NW-SE-oriented neotectonic fault zones, in which some segments consist of highly folded thick Triassic limestone crossed by the Yangtze River. Several limestone hills, currently located next to the river channel, serve as nodes that create large vortices in the river, thereby accelerating downcutting on the riverbed composed of limestone highly susceptible to physical corrosion and chemical dissolution. Hydrological records indicate that the nodal hills and channel configuration at Tianjiazhen do not impact on normal flow discharges but discharges > 50,000 m 3s - 1 are slowed down for 2-3 days. Catastrophic floods are held up for even longer periods. These inevitably result in elevated flood stages upstream of prolonged duration, affecting large cities such as Wuhan and a very large number of people.

Pesticide Occurrence and Distribution in the Lower Clackamas River Basin, Oregon, 2000-2005

USGS Publications Warehouse

Carpenter, Kurt D.; Sobieszczyk, Steven; Arnsberg, Andrew J.; Rinella, Frank A.

2008-01-01

Pesticide occurrence and distribution in the lower Clackamas River basin was evaluated in 2000?2005, when 119 water samples were analyzed for a suite of 86?198 dissolved pesticides. Sampling included the lower-basin tributaries and the Clackamas River mainstem, along with paired samples of pre- and post-treatment drinking water (source and finished water) from one of four drinking water-treatment plants that draw water from the lower river. Most of the sampling in the tributaries occurred during storms, whereas most of the source and finished water samples from the study drinking-water treatment plant were obtained at regular intervals, and targeted one storm event in 2005. In all, 63 pesticide compounds were detected, including 33 herbicides, 15 insecticides, 6 fungicides, and 9 pesticide degradation products. Atrazine and simazine were detected in about half of samples, and atrazine and one of its degradates (deethylatrazine) were detected together in 30 percent of samples. Other high-use herbicides such as glyphosate, triclopyr, 2,4-D, and metolachlor also were frequently detected, particularly in the lower-basin tributaries. Pesticides were detected in all eight of the lower-basin tributaries sampled, and were also frequently detected in the lower Clackamas River. Although pesticides were detected in all of the lower basin tributaries, the highest pesticide loads (amounts) were found in Deep and Rock Creeks. These medium-sized streams drain a mix of agricultural land (row crops and nurseries), pastureland, and rural residential areas. The highest pesticide loads were found in Rock Creek at 172nd Avenue and in two Deep Creek tributaries, North Fork Deep and Noyer Creeks, where 15?18 pesticides were detected. Pesticide yields (loads per unit area) were highest in Cow and Carli Creeks, two small streams that drain the highly urban and industrial northwestern part of the lower basin. Other sites having relatively high pesticide yields included middle Rock Creek and upper Noyer Creek, which drain basins having nurseries, pasture, and rural residential land. Some concentrations of insecticides (diazinon, chlorpyrifos, azinphos-methyl, and p,p?-DDE) exceeded U.S. Environmental Protection Agency (USEPA) aquatic-life benchmarks in Carli, Sieben, Rock, Noyer, Doane, and North Fork Deep Creeks. One azinphos-methyl concentration in Doane Creek (0.21 micrograms per liter [?g/L]) exceeded Federal and State of Oregon benchmarks for the protection of fish and benthic invertebrates. Concentrations of several other pesticide compounds exceeded non-USEPA benchmarks. Twenty-six pesticides or degradates were detected in the Clackamas River mainstem, typically at much lower concentrations than those detected in the lower-basin tributaries. At least 1 pesticide was detected in 65 percent of 34 samples collected from the Clackamas River, with an average of 2?3 pesticides per sample. Pesticides were detected in 9 (or 60 percent) of the 15 finished water samples collected from the study water-treatment plant during 2003?2005. These included 10 herbicides, 1 insecticide, 1 fungicide, 1 insect repellent, and 2 pesticide degradates. The herbicides diuron and simazine were the most frequently detected (four times each during the study), at concentrations far below human-health benchmarks?USEPA Maximum Contaminant Levels or U.S. Geological Survey human Health-Based Screening Levels (HBSLs). The highest pesticide concentration in finished drinking water was 0.18 ?g/L of diuron, which was 11 times lower than its low HBSL benchmark. Although 0?2 pesticides were detected in most finished water samples, 9 and 6 pesticides were detected in 2 storm-associated samples from May and September 2005, respectively. Three of the unregulated compounds detected in finished drinking water (diazinon-oxon, deethylatrazine [CIAT], and N, N-diethyl-m-toluamide [DEET]) do not have human-health benchmarks available for comparison. Although most of the 51 curren

Phenomena and characteristics of barrier river reaches in the middle and lower Yangtze River, China

NASA Astrophysics Data System (ADS)

You, Xingying; Tang, Jinwu

2017-06-01

Alluvial river self-adjustment describes the mechanism whereby a river that was originally in an equilibrium state of sediment transport encounters some disturbance that destroys the balance and results in responses such as riverbed deformation. A systematic study of historical and recent aerial photographs and topographic maps in the Middle and Lower Reaches of the Yangtze River (MLYR) shows that river self-adjustment has the distinguishing feature of transferring from upstream to downstream, which may affect flood safety, waterway morphology, bank stability, and aquatic environmental safety over relatively long reaches downstream. As a result, it is necessary to take measures to control or block this transfer. Using the relationship of the occurrence time of channel adjustments between the upstream and downstream, 34 single-thread river reaches in the MLYR were classified into four types: corresponding, basically corresponding, basically not corresponding, not corresponding. The latter two types, because of their ability to prevent upstream channel adjustment from transferring downstream, are called barrier river reaches in this study. Statistics indicate that barrier river reaches are generally single thread and slightly curved, with a narrow and deep cross-sectional morphology, and without flow deflecting nodes in the upper and middle parts of reaches. Moreover, in the MLYR, barrier river reaches have a hydrogeometric coefficient of {<}{4}, a gradient {>}1.2‱, a silty clay content of the concave bank {>}{9.5}%, and a median diameter of the bed sediment {>}{0.158} mm. The barrier river reach mechanism lies in that can effectively centralise the planimetric position of the main stream from different upstream directions, meaning that no matter how the upper channel adjusts, the main stream shows little change, providing relatively stable inflow conditions for the lower reaches. Regarding river regulation, it is necessary to optimise the benefits of barrier river reaches; long river reaches without barrier properties should be systematically planned and regulated; drastic bank collapse and sandbar shrinking should be urgently controlled to prevent the loss of barrier effects.

Impact of organic matter source and quality on living benthic foraminiferal distribution on a river-dominated continental margin: A study of the Portuguese margin

NASA Astrophysics Data System (ADS)

Dessandier, Pierre-Antoine; Bonnin, Jérôme; Kim, Jung-Hyun; Bichon, Sabrina; Deflandre, Bruno; Grémare, Antoine; Sinninghe Damsté, Jaap S.

2016-06-01

Living (rose Bengal stained) benthic foraminifera were investigated on surface sediments from 23 stations from the river-dominated northwestern Portuguese margin. Samples were collected in March 2011, following the period of the maximum rainfall over the Iberian Peninsula, between 20 and 2000 m water depth along five cross-margin transects. Four of them are located off the Douro, Mondego, Tagus, and Sado Rivers and one off the Estremadura coast. The major objectives of this study are (1) to assess the impact of organic matter of various origin and quality on the benthic foraminifera and (2) to investigate the spatial differences of faunal distribution from coastal waters to the deep sea under river influences. To do this, sedimentological and biogeochemical characteristics of the sediments were identified by measuring grain size, oxygen penetration depth, total organic carbon (TOC) content, stable carbon isotopic composition of TOC (δ13CTOC) and concentration of pigments and amino acids. Based on the principal component and cluster analyses of the environmental data, three major geographical groups are identified: (1) deep stations, (2) coastal and middle slope stations, and (3) shelf stations under river influence. At the deepest stations, species are associated with high organic matter (OM) quantity but low OM quality, where Uvigerina mediterranea, Hoeglundina elegans, and agglutinated species such as Reophax scorpiurus or Bigenerina nodosaria are dominant. All stations off the Sado River, which is the most affected area by the anthropogenic influence, are also characterized by high quantity but low quality of OM with the minimum faunal density and diversity within the study area. Middle slope stations are associated with low OM content and coarse sediments (Q50) with the predominance of N. scaphum. Shallow shelf stations close to the Douro and Tagus River mouths show a dominance of taxa (e.g., Ammonia beccarii, Bulimina aculeata, Eggerelloides scaber, Nonion scaphum, Cancris auriculus, and Quinqueloculina seminula) adapted to environments characterized by high OM quality (high fresh chlorophyll (Chl a/Phaeo)) and available amino acids (enzymatically hydrolyzable amino acid (EHAA)/total enzymatically hydrolyzable amino acid (THAA)). The Biotic and Environmental linking analysis suggests that the benthic foraminiferal distribution is mostly controlled by three environmental parameters, i.e., TOC (quantity), EHAA/THAA (quality), and δ13CTOC (source). Hence, this study clearly highlights that the quantitative and qualitative inputs of OM and its source are the most important factors controlling the living benthic foraminiferal distribution with clear influences between the different rivers. This study also suggests a good tolerance of several species for river discharges where the OM quality is high.

Deglacial 'ping-pong' between East Asian Monsoon, North Pacific Meridional Overturning Circulation, and sediment dynamics along the deep northern South China Sea margin

NASA Astrophysics Data System (ADS)

Sarnthein, M.

2011-12-01

On the basis of marine and speleothem paleoclimate records it is widely accepted that the East Asian summer monsoon was strongly reduced during Heinrich stadial 1 (HS-1) such as during preceding stadials. Accordingly, Eastern Asia suffered from severe aridity from 17.4 - 14.7 ka, when all great Asian rivers from the Mekong in the south up to the Amur in the north almost ceased flowing into the Western Pacific. Today, the modern freshwater input of these rivers sums up to approx. 0.165 Sverdrups (in addition to the river discharge from Canada and Alaska), a flow possibly similar to the meltwater outbreaks that induced Atlantic Heinrich stadials. The East Asian freshwater feeds the Kuroshio/Oyashio Currents which act as "rain gutter" and finally discharge the freshwater up to the subarctic North Pacific (sensu Emile-Geay, et al., 2003). Indeed, the great reduction in both the fluvial freshwater discharge and the direct monsoon precipitation over the N.W. Pacific during HS-1 matched a significant rise in sea surface salinity in the subarctic North Pacific. Most important, it was precisely coeval with a thousand-year long pulse of North Pacific deep-water convection down to >3600 m water depth. This event obviously reflects a direct response to the great reduction in East Asian monsoon precipitation and is inferred from a major reduction of planktic reservoir ages from 1150 to 300 yr in the northwest Pacific and in particular, from an abrupt reduction of benthic ventilation ages by 1500 yr and a prominent minimum in bottom water alkalinity inferred from minimum delta11B, that suggests intensive vertical downmixing. The ventilated North Pacific deep waters, in turn, probably formed a western boundary current per analogy to that along the modern West Atlantic margin and finally entered the South China Sea with a lag of centuries. Today the track of the Pacific inflow can be traced along the northern margin of the South China Sea near 2000 m water depth by means of erosional furrows that reflect winnowing and/or erosion. The great deglacial incursion of North Pacific deep waters is reflected by a prominent reduction in deep-water ventilation ages and a maximum in CaCO3 preservation that leads to an aragonite spike. Near the end of previous glacial terminations II, III, and V (i.e., in the context of Heinrich stadials associated) the deglacial incursion pulses of North Pacific Deep Water probably resulted in major erosional hiatuses found at ODP Site 1144 to the south of HongKong, which each may finally be traced back to a short-term dramatic reduction in East Asian monsoon moisture during deglacial Heinrich events as ultimate driver of short-term convection events in the N.W. Pacific. Ref.: Emile-Geay, J., et al., 2003, Warren revisited: Atmospheric freshwater fluxes and 'Why is no deep water formed in the North Pacific.' - JGR 108, C6, 3178, doi:10.1029/2001JC001058.

Tracking groundwater discharge to a large river using tracers and geophysics.

PubMed

Harrington, Glenn A; Gardner, W Payton; Munday, Tim J

2014-01-01

Few studies have investigated large reaches of rivers in which multiple sources of groundwater are responsible for maintaining baseflow. This paper builds upon previous work undertaken along the Fitzroy River, one of the largest perennial river systems in north-western Australia. Synoptic regional-scale sampling of both river water and groundwater for a suite of environmental tracers ((4) He, (87) Sr/(86) Sr, (222) Rn and major ions), and subsequent modeling of tracer behavior in the river, has enabled definition and quantification of groundwater input from at least three different sources. We show unambiguous evidence of both shallow "local" groundwater, possibly recharged to alluvial aquifers beneath the adjacent floodplain during recent high-flow events, and old "regional" groundwater introduced via artesian flow from deep confined aquifers. We also invoke hyporheic exchange and either bank return flow or parafluvial flow to account for background (222) Rn activities and anomalous chloride trends along river reaches where there is no evidence of the local or regional groundwater inputs. Vertical conductivity sections acquired through an airborne electromagnetic (AEM) survey provide insights to the architecture of the aquifers associated with these sources and general groundwater quality characteristics. These data indicate fresh groundwater from about 300 m below ground preferentially discharging to the river, at locations consistent with those inferred from tracer data. The results demonstrate how sampling rivers for multiple environmental tracers of different types-including stable and radioactive isotopes, dissolved gases and major ions-can significantly improve conceptualization of groundwater-surface water interaction processes, particularly when coupled with geophysical techniques in complex hydrogeological settings. © 2013, National Ground Water Association.

Heat tracing to determine spatial patterns of hyporheic exchange across a river transect

NASA Astrophysics Data System (ADS)

Lu, Chengpeng; Chen, Shuai; Zhang, Ying; Su, Xiaoru; Chen, Guohao

2017-09-01

Significant spatial variability of water fluxes may exist at the water-sediment interface in river channels and has great influence on a variety of water issues. Understanding the complicated flow systems controlling the flux exchanges along an entire river is often limited due to averaging of parameters or the small number of discrete point measurements usually used. This study investigated the spatial pattern of the hyporheic flux exchange across a river transect in China, using the heat tracing approach. This was done with measurements of temperature at high spatial resolution during a 64-h monitoring period and using the data to identify the spatial pattern of the hyporheic exchange flux with the aid of a one-dimensional conduction-advection-dispersion model (VFLUX). The threshold of neutral exchange was considered as 126 L m-2 d-1 in this study and the heat tracing results showed that the change patterns of vertical hyporheic flux varied with buried depth along the river transect; however, the hyporheic flux was not simply controlled by the streambed hydraulic conductivity and water depth in the river transect. Also, lateral flow dominated the hyporheic process within the shallow high-permeability streambed, while the vertical flow was dominant in the deep low-permeability streambed. The spatial pattern of hyporheic exchange across the river transect was naturally controlled by the heterogeneity of the streambed and the bedform of the stream cross-section. Consequently, a two-dimensional conceptual illustration of the hyporheic process across the river transect is proposed, which could be applicable to river transects of similar conditions.

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

USGS Publications Warehouse

Williams, John R.

1970-01-01

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

Modelling the Spread of Farming in the Bantu-Speaking Regions of Africa: An Archaeology-Based Phylogeography

PubMed Central

Russell, Thembi; Silva, Fabio; Steele, James

2014-01-01

We use archaeological data and spatial methods to reconstruct the dispersal of farming into areas of sub-Saharan Africa now occupied by Bantu language speakers, and introduce a new large-scale radiocarbon database and a new suite of spatial modelling techniques. We also introduce a method of estimating phylogeographic relationships from archaeologically-modelled dispersal maps, with results produced in a format that enables comparison with linguistic and genetic phylogenies. Several hypotheses are explored. The ‘deep split’ hypothesis suggests that an early-branching eastern Bantu stream spread around the northern boundary of the equatorial rainforest, but recent linguistic and genetic work tends not to support this. An alternative riverine/littoral hypothesis suggests that rivers and coastlines facilitated the migration of the first farmers/horticulturalists, with some extending this to include rivers through the rainforest as conduits to East Africa. More recently, research has shown that a grassland corridor opened through the rainforest at around 3000–2500 BP, and the possible effect of this on migrating populations is also explored. Our results indicate that rivers and coasts were important dispersal corridors, but do not resolve the debate about a ‘Deep Split’. Future work should focus on improving the size, quality and geographical coverage of the archaeological 14C database; on augmenting the information base to establish descent relationships between archaeological sites and regions based on shared material cultural traits; and on refining the associated physical geographical reconstructions of changing land cover. PMID:24498213

Influence of Wastewater Discharge on the Metabolic Potential of the Microbial Community in River Sediments.

PubMed

Li, Dong; Sharp, Jonathan O; Drewes, Jörg E

2016-01-01

To reveal the variation of microbial community functions during water filtration process in river sediments, which has been utilized widely in natural water treatment systems, this study investigates the influence of municipal wastewater discharge to streams on the phylotype and metabolic potential of the microbiome in upstream and particularly various depths of downstream river sediments. Cluster analyses based on both microbial phylogenetic and functional data collectively revealed that shallow upstream sediments grouped with those from deeper subsurface downstream regions. These sediment samples were distinct from those found in shallow downstream sediments. Functional genes associated with carbohydrate, xenobiotic, and certain amino acid metabolisms were overrepresented in upstream and deep downstream samples. In contrast, the more immediate contact with wastewater discharge in shallow downstream samples resulted in an increase in the relative abundance of genes associated with nitrogen, sulfur, purine and pyrimidine metabolisms, as well as restriction-modification systems. More diverse bacterial phyla were associated with upstream and deep downstream sediments, mainly including Actinobacteria, Planctomycetes, and Firmicutes. In contrast, in shallow downstream sediments, genera affiliated with Betaproteobacteria and Gammaproteobacteria were enriched with putative functions that included ammonia and sulfur oxidation, polyphosphate accumulation, and methylotrophic bacteria. Collectively, these results highlight the enhanced capabilities of microbial communities residing in deeper stream sediments for the transformation of water contaminants and thus provide a foundation for better design of natural water treatment systems to further improve the removal of contaminants.

Riverine transport of terrestrial organic matter to the North Catalan margin, NW Mediterranean Sea

NASA Astrophysics Data System (ADS)

Sanchez-Vidal, Anna; Higueras, Marina; Martí, Eugènia; Liquete, Camino; Calafat, Antoni; Kerhervé, Philippe; Canals, Miquel

2013-11-01

Rivers are the primary pathway for organic matter transport from the terrestrial to the marine environment and, thus, river fluxes are critical in regulating the quantity of terrestrial organic matter that reaches the coastal ecosystems. Hydrodynamic processes typical of the coastal zone can lead to the transport of terrestrial organic matter across the continental shelf and beyond. Such organic matter can eventually reach the deep margin and basin ecosystems. Riverine inputs of organic matter to the sea can be a significant food source to marine ecosystems contributing to carbon cycling in these ecosystems. In order to assess the marine carbon cycle it is essential to know the biogeochemical characteristics and temporal dynamics of the fluvial organic matter input discharged by rivers to the coastal zone. In this study we present a one and a half year long (November 2008 to May 2010) assessment on organic carbon (OC) and nitrogen (N) inputs from the three main rivers discharging into the North Catalan margin (Tordera, Ter and Fluvià, from south to north). Furthermore, we investigate the characteristics of the particulate organic matter discharged by these rivers by means of stable isotopic (δ13C and δ15N) and grain size analyses. We found that the hydrological regime of the rivers is a relevant factor in regulating the quantity and mediating the quality of organic matter inputs to the North Catalan margin. Overall, the three main rivers discharging into the study area deliver 1266 and 159 tonnes of terrestrial OC and N per year, respectively, to the coastal zone. Most of the OC and N load is transported during floods, which indicates that the Mediterranean climate of the area, with a strong seasonal contrast in precipitation, determines the timing of the main inputs of OC and N to the sea. Therefore, the annual OC and N load experiences a high temporal variability associated to the number and magnitude of floods with in each hydrological year. In addition, we found that water reservoirs along the rivers act as traps for terrestrial organic matter, reducing its delivery and ultimate burial into marine sediments. River hydrology also affects the quality of organic matter that reaches the coastal zone (both in terms of C and N) by shifting the relative weight of the various sources of terrestrial organic matter. During low river discharge (i.e., in summer and early autumn) the main contributor to the organic matter pool is mostly associated with freshwater primary producers, whereas with relatively high water flows (i.e., in winter and spring) the main contributor is associated with erosion and release of soil organic matter. Furthermore, the impact of waste water treatment plants into the studied rivers results in the alteration of the isotopic signal of suspended N. The three studied rivers play a major role in transporting terrestrial organic matter to the North Catalan margin, but the fraction that is exported to the deep margin by high-energy episodic hydrodynamic events, such as large coastal storms, has a minor importance.

Deep Rivers; A Portfolio: 20 Contemporary Black American Poets; Teachers' Guide.

ERIC Educational Resources Information Center

Madgett, Naomi L., Ed.

This publication offers 20 bulletin-board-oriented posters of varying colors and sizes (from 8" X 13" to 10" X 15"), each of which features a poem by a contemporary black American poet. Poems have been selected for their literary excellence, diversity, appropriateness, and student appeal, and are intended to familiarize students with the work of…

Dredging: An Annotated Bibliography on Operations, Equipment, and Processes. Revision.

DTIC Science & Technology

1982-03-01

establishing producing centers, enterprises, financial planning, and technical specifications for plant and equipment. Drilling and laboratory results are...summarised, and resource, market, technological and environmental bases described. Prospect drilling of calcareous sandstone (kurkar and calcarenite...Automation; Pumps and impellers; Cavitation; Cost and econ- omy of dredging; Drilling and blasting; Spoil disposal; Deep sea dredg- ing; River dredging

Estimates of Deep Percolation Beneath Native Vegetation, Irrigated Fields, and The Amargosa-River Channel, Amargosa Desert, Nye County, Nevada

DTIC Science & Technology

2003-01-01

based primarily on measurements of spring discharge (Walker and Eakin, 1963; Winograd and Thordarson , 1975; Dudley and Larson, 1976). The other...vadose-zone profiles from the northern Mojave Desert: Water Resources Research, v. 38, no. 12, p. 27-1 to 27-12. Winograd, I.J., and Thordarson , W

Importance of lateral flux and its percolation depth on organic carbon export in Arctic tundra soil: Implications from a soil leaching experiment: Changes of OC in Arctic Soil Leachate

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

Zhang, Xiaowen; Hutchings, Jack A.; Bianchi, Thomas S.

Temperature rise in the Arctic is causing deepening of active layers and resulting in the mobilization of deep permafrost dissolved organic matter (DOM). However, the mechanisms of DOM mobilization from Arctic soils, especially upper soil horizons which are drained most frequently through a year, are poorly understood. Here, we conducted a short-term leaching experiment on surface and deep organic active layer soils, from the Yukon River basin, to examine the effects of DOM transport on bulk and molecular characteristics. Our data showed a net release of DOM from surface soils equal to an average of 5% of soil carbon. Conversely,more » deep soils percolated with surface leachates retained up to 27% of bulk DOM-while releasing fluorescent components (up to 107%), indicating selective release of aromatic components (e.g. lignin, tannin), while retaining non-chromophoric components, as supported by spectrofluorometric and ultra high resolution mass spectroscopic techniques. Our findings highlight the importance of the lateral flux of DOM on ecosystem carbon balance as well as processing of DOM transport through organic active layer soils en route to rivers and streams. This work also suggests the potential role of leachate export as an important mechanism of C losses from Arctic soils, in comparison with the more traditional pathway from soil to atmosphere in a warming Arctic.« less

Movement and habitat use by radio-tagged paddlefish in the upper Mississippi River and tributaries

USGS Publications Warehouse

Zigler, S.J.; Dewey, M.R.; Knights, B.C.; Runstrom, A.L.; Steingraeber, M.T.

2003-01-01

We used radio telemetry to evaluate the movement and habitat use of paddlefish Polyodon spathula in the upper Mississippi River and two tributary rivers. Radio transmitters were surgically implanted into 71 paddlefish in Navigation Pools 5A and 8 of the upper Mississippi River, the Chippewa River, and the Wisconsin River during fall 1994 through fall 1996. Radiotagged paddlefish were located through summer 1997. The range of paddlefish movement was typically low during all seasons except spring, but some paddlefish moved throughout the 420-km extent of the study area. Paddlefish tagged in the Chippewa River were closely linked with the upper Mississippi River, as substantial portions of the population inhabited the adjacent Navigation Pool 4 each spring; paddlefish in the Wisconsin River, however, rarely ventured out of that tributary. The use of aquatic area types by paddlefish varied among the study reaches. A cartographic model of paddlefish habitat suitability was developed for Navigation Pool 8 based on geographic information systems (GIS) coverages of bathymetry and current velocity. The value of paddlefish habitat in the cartographic model increased with depth and decreased with current velocity. For example, areas modeled as excellent corresponded to regions classified as having both deep water (greater than or equal to6.0 m) and negligible (<5 cm/s) current velocities. Our study suggests that aquatic area types are an inadequate basis for making sound management decisions regarding the critical habitats of paddlefish in complex riverine systems because such strata rely on gross geomorpological features rather than on the physicochemical variables that fish use to choose habitats. The development of systemic GIS coverages of such variables could improve the understanding of fish habitat selection and management in the upper Mississippi River.

Quantifying hyporheic exchange dynamics in a highly regulated large river reach

NASA Astrophysics Data System (ADS)

Zhou, T.; Bao, J.; Huang, M.; Hou, Z.; Arntzen, E.; Mackley, R.; Harding, S.; Crump, A.; Xu, Y.; Song, X.; Chen, X.; Stegen, J.; Hammond, G. E.; Thorne, P. D.; Zachara, J. M.

2016-12-01

Hyporheic exchange is an important mechanism taking place in riverbanks and riverbed sediments, where the river water and shallow groundwater mix and interact with each other. The direction and magnitude of hyporheic flux that penetrates the river bed and residence time of river water in the hyporheic zone are critical for biogeochemical processes such as carbon and nitrogen cycling, and biodegradation of organic contaminants. Hyporheic flux can be quantified using many direct and indirect measurements as well as analytical and numerical modeling tools. However, in a relatively large river, these methods can be limited by the accessibility, spatial constraints, complexity of geomorphologic features and subsurface properties, and computational power. In rivers regulated by hydroelectric dams, quantifying hyporheic fluxes becomes more challenging due to frequent hydropeaking events created by dam operations. In this study, we developed and validated methods that combined field measurements and numerical modeling for estimating hyporheic fluxes across the river bed in a 7-km long reach of the highly regulated Columbia River. The reach has a minimum width of about 800 meters and variations in river stage within a day could be up to two meters due to the upstream dam operations. In shallow water along the shoreline, vertical thermal profiles measured by self-recording thermistors were combined with time series of hydraulic gradient derived from river stage and water level at in-land wells to estimate the hyporheic flux rate. For the deep section, a high resolution computational fluid dynamics (CFD) modeling framework was developed to characterize the spatial distribution of flux rates at the river bed and the residence time of hyporheic flow at different river flow conditions. Our modeling results show that the rates of hyporheic exchange and residence time are controlled by (1) hydrostatic pressure induced by river stage fluctuations, and (2) hydrodynamic drivers associated with flow velocity variations, which also to certain extent dependent on flow conditions.

Morphometric convergence between Proterozoic and post-vegetation rivers

PubMed Central

Ielpi, Alessandro; Rainbird, Robert H.; Ventra, Dario; Ghinassi, Massimiliano

2017-01-01

Proterozoic rivers flowed through barren landscapes, and lacked interactions with macroscopic organisms. It is widely held that, in the absence of vegetation, fluvial systems featured barely entrenched channels that promptly widened over floodplains during floods. This hypothesis has never been tested because of an enduring lack of Precambrian fluvial-channel morphometric data. Here we show, through remote sensing and outcrop sedimentology, that deep rivers were developed in the Proterozoic, and that morphometric parameters for large fluvial channels might have remained within a narrow range over almost 2 billion years. Our data set comprises fluvial-channel forms deposited a few tens to thousands of kilometres from their headwaters, likely the record of basin- to craton-scale systems. Large Proterozoic channel forms present width:thickness ranges matching those of Phanerozoic counterparts, suggesting closer parallels between their fluvial dynamics. This outcome may better inform analyses of extraterrestrial planetary surfaces and related comparisons with pre-vegetation Earth landscapes. PMID:28548109

Morphometric convergence between Proterozoic and post-vegetation rivers.

PubMed

Ielpi, Alessandro; Rainbird, Robert H; Ventra, Dario; Ghinassi, Massimiliano

2017-05-26

Proterozoic rivers flowed through barren landscapes, and lacked interactions with macroscopic organisms. It is widely held that, in the absence of vegetation, fluvial systems featured barely entrenched channels that promptly widened over floodplains during floods. This hypothesis has never been tested because of an enduring lack of Precambrian fluvial-channel morphometric data. Here we show, through remote sensing and outcrop sedimentology, that deep rivers were developed in the Proterozoic, and that morphometric parameters for large fluvial channels might have remained within a narrow range over almost 2 billion years. Our data set comprises fluvial-channel forms deposited a few tens to thousands of kilometres from their headwaters, likely the record of basin- to craton-scale systems. Large Proterozoic channel forms present width:thickness ranges matching those of Phanerozoic counterparts, suggesting closer parallels between their fluvial dynamics. This outcome may better inform analyses of extraterrestrial planetary surfaces and related comparisons with pre-vegetation Earth landscapes.

Simulating the Pineapple Express in the half degree Community Climate System Model, CCSM4

NASA Astrophysics Data System (ADS)

Shields, Christine A.; Kiehl, Jeffrey T.

2016-07-01

Atmospheric rivers are recognized as major contributors to the poleward transport of water vapor. Upon reaching land, these phenomena also play a critical role in extreme precipitation and flooding events. The Pineapple Express (PE) is defined as an atmospheric river extending out of the deep tropics and reaching the west coast of North America. Community Climate System Model (CCSM4) high-resolution ensemble simulations for the twentieth and 21st centuries are diagnosed to identify the PE. Analysis of the twentieth century simulations indicated that the CCSM4 accurately captures the spatial and temporal climatology of the PE. Analysis of the end 21st century simulations indicates a significant increase in storm duration and intensity of precipitation associated with landfall of the PE. Only a modest increase in the number of atmospheric rivers of a few percent is projected for the end of 21st century.

The application of hydrometeorological data obtained by remote sensing techniques for multipurpose reservoir operations. [Arizona

NASA Technical Reports Server (NTRS)

Warskow, W. L.; Wilson, T. T., Jr.; Kirdar, K.

1975-01-01

Watershed snowpack and streamflow data obtained and transmitted by (ERTS) satellite were used in the operational and water management decisions in the Salt River Project. Located in central Arizona, the Project provides water and electric power for the more than 1.1 million residents of the Salt River Valley. The water supply source is a 33,670 square kilometer (13,000 square mile) watershed and 250 deep well pumps. Six storage reservoirs, four of which have hydroelectric capability, located on two river systems have a storage capacity of over 246,600 hectare-meters (2,000,000 AF.). Information from the watershed during the normal runoff period of December to May and more especially during critical periods of high runoff and minimum reservoir storage capacity is necessary for the reservoir operation regimen. Extent of the snowpack, depth of snow, and the condition of the pack were observed in aerial flights over the watershed.

Earthquakes drive large-scale submarine canyon development and sediment supply to deep-ocean basins.

PubMed

Mountjoy, Joshu J; Howarth, Jamie D; Orpin, Alan R; Barnes, Philip M; Bowden, David A; Rowden, Ashley A; Schimel, Alexandre C G; Holden, Caroline; Horgan, Huw J; Nodder, Scott D; Patton, Jason R; Lamarche, Geoffroy; Gerstenberger, Matthew; Micallef, Aaron; Pallentin, Arne; Kane, Tim

2018-03-01

Although the global flux of sediment and carbon from land to the coastal ocean is well known, the volume of material that reaches the deep ocean-the ultimate sink-and the mechanisms by which it is transferred are poorly documented. Using a globally unique data set of repeat seafloor measurements and samples, we show that the moment magnitude ( M w ) 7.8 November 2016 Kaikōura earthquake (New Zealand) triggered widespread landslides in a submarine canyon, causing a powerful "canyon flushing" event and turbidity current that traveled >680 km along one of the world's longest deep-sea channels. These observations provide the first quantification of seafloor landscape change and large-scale sediment transport associated with an earthquake-triggered full canyon flushing event. The calculated interevent time of ~140 years indicates a canyon incision rate of 40 mm year -1 , substantially higher than that of most terrestrial rivers, while synchronously transferring large volumes of sediment [850 metric megatons (Mt)] and organic carbon (7 Mt) to the deep ocean. These observations demonstrate that earthquake-triggered canyon flushing is a primary driver of submarine canyon development and material transfer from active continental margins to the deep ocean.

Earthquakes drive large-scale submarine canyon development and sediment supply to deep-ocean basins

PubMed Central

Mountjoy, Joshu J.; Howarth, Jamie D.; Orpin, Alan R.; Barnes, Philip M.; Bowden, David A.; Rowden, Ashley A.; Schimel, Alexandre C. G.; Holden, Caroline; Horgan, Huw J.; Nodder, Scott D.; Patton, Jason R.; Lamarche, Geoffroy; Gerstenberger, Matthew; Micallef, Aaron; Pallentin, Arne; Kane, Tim

2018-01-01

Although the global flux of sediment and carbon from land to the coastal ocean is well known, the volume of material that reaches the deep ocean—the ultimate sink—and the mechanisms by which it is transferred are poorly documented. Using a globally unique data set of repeat seafloor measurements and samples, we show that the moment magnitude (Mw) 7.8 November 2016 Kaikōura earthquake (New Zealand) triggered widespread landslides in a submarine canyon, causing a powerful “canyon flushing” event and turbidity current that traveled >680 km along one of the world’s longest deep-sea channels. These observations provide the first quantification of seafloor landscape change and large-scale sediment transport associated with an earthquake-triggered full canyon flushing event. The calculated interevent time of ~140 years indicates a canyon incision rate of 40 mm year−1, substantially higher than that of most terrestrial rivers, while synchronously transferring large volumes of sediment [850 metric megatons (Mt)] and organic carbon (7 Mt) to the deep ocean. These observations demonstrate that earthquake-triggered canyon flushing is a primary driver of submarine canyon development and material transfer from active continental margins to the deep ocean. PMID:29546245

Water Quality Assessment for Deep-water Channel area of Guangzhou Port based on the Comprehensive Water Quality Identification Index Method

NASA Astrophysics Data System (ADS)

Chen, Yi

2018-03-01

The comprehensive water quality identification index method is able to assess the general water quality situation comprehensively and represent the water quality classification; water environment functional zone achieves pollution level and standard objectively and systematically. This paper selects 3 representative zones along deep-water channel of Guangzhou port and applies comprehensive water quality identification index method to calculate sea water quality monitoring data for different selected zones from year 2006 to 2014, in order to investigate the temporal variation of water quality along deep-water channel of Guangzhou port. The comprehensive water quality level from north to south presents an increased trend, and the water quality of the three zones in 2014 is much better than in 2006. This paper puts forward environmental protection measurements and suggestions for Pearl River Estuary, provides data support and theoretical basis for studied sea area pollution prevention and control.

Sudden deep gas eruption nearby Rome's airport of Fiumicino

NASA Astrophysics Data System (ADS)

Ciotoli, Giancarlo; Etiope, Giuseppe; Florindo, Fabio; Marra, Fabrizio; Ruggiero, Livio; Sauer, Peter E.

2013-11-01

24 August 2013 a sudden gas eruption from the ground occurred in the Tiber river delta, nearby Rome's international airport of Fiumicino. We assessed that this gas, analogous to other minor vents in the area, is dominantly composed of deep, partially mantle-derived CO2, as in the geothermal gas of the surrounding Roman Comagmatic Province. Increased amounts of thermogenic CH4 are likely sourced from Meso-Cenozoic petroleum systems, overlying the deep magmatic fluids. We hypothesize that the intersection of NE-SW and N-S fault systems, which at regional scale controls the location of the Roman volcanic edifices, favors gas uprising through the impermeable Pliocene and deltaic Holocene covers. Pressurized gas may temporarily be stored below these covers or within shallower sandy, permeable layers. The eruption, regardless the triggering cause—natural or man-made, reveals the potential hazard of gas-charged sediments in the delta, even at distances far from the volcanic edifices.

Geochemistry of water in the Fort Union Formation of the northern Powder River basin, southeastern Montana

USGS Publications Warehouse

Lee, Roger W.

1980-01-01

Shallow water in the coal-bearing Fort Union Formation of southeastern Montana was investigated to provide a better understanding of the geochemistry. Springs, wells less than 200 feet deep, and wells greater then 200 feet deep were observed to have different water qualities. Overall, the ground water exists as two systems: a mosaic of shallow, chemically dynamic, and localized recharge-discharge cells superimposed on a deeper, chemically static regional system. Water chemistry is highly variable in the shallow system, whereas sodium and bicarbonate waters characterize the deeper system. Within the shallow system , springs, and wells less than 200 feet deep show predominantly sodium and sulfate enrichment processes from recharge to discharge. These processes are consistent with the observed aquifer mineralogy and aqueous chemistry. However, intermittent mixing with downward moving recharge waters or upward moving deeper waters, and bacterially catalyzed sulfate reduction, may cause apparent reversals in these processes. (USGS)

Geochemistry of water in the Fort Union formation of the northern Powder River basin, southeastern Montana

USGS Publications Warehouse

Lee, Roger W.

1981-01-01

Shallow water in the coal-bearing Paleocene Fort Union Formation of southeastern Montana was investigated to provide a better understanding of its geochemistry. Springs, wells less than 200 feet deep, and wells greater than 200 feet deep were observed to have different water qualities. Overall, the ground water exists as two systems: a mosaic of shallow, chemically dynamic, and localized recharge-discharge cells superimposed on a deeper, chemically static regional system. Water chemistry is highly variable in the shallow system; whereas, waters containing sodium and bicarbonate characterize the deeper system. Within the shallow system, springs and wells less than 200 feet deep show predominantly sodium and sulfate enrichment processes from recharge to discharge. These processes are consistent with the observed aquifer mineralogy and aqueous chemistry. However, intermittent mixing with downward moving recharge waters or upward moving deeper waters, and bacterially catalyzed sulfate reduction, may cause apparent reversals in these processes.

Geologic map of the Chelan 30-minute by 60-minute quadrangle, Washington

USGS Publications Warehouse

Tabor, R.W.; Frizzell, V.A.; Whetten, J.T.; Waitt, R.B.; Swanson, D.A.; Byerly, G.R.; Booth, D.B.; Hetherington, M.J.; Zartman, R.E.

1987-01-01

Summary -- The Chelan quadrangle hosts a wide variety of rocks and deposits and display a long geologic history ranging from possible Precambrian to Recent. Two major structures, the Leavenworth and Entiat faults divide cross the quadrangle from southeast to northwest and bound the Chiwaukum 'graben', a structural low preserving Tertiary sedimentary rocks between blocks of older, metamorphic and igneous rocks. Pre-Tertiary metamorphic rocks in the quadrangle are subdivided into five major tectonostratigraphic terranes: (1) the Ingalls terrane, equivalent to the Jurassic Ingalls Tectonic Complex of probable mantle and deep oceanic rocks origin, (2) the Nason terrane, composed of the Chiwaukum Schist and related gneiss, (3) the Swakane terrane, made up entirely of the Swakane Biotite Gneiss, a metamorphosed, possibly Precambrian, sedimentary and/or volcanic rock, (4) the Mad River terrane composed mostly of the rocks of the Napeequa River area (Napeequa Schist), a unit of oceanic protolith now considered part of the Chelan Mountains terrane (the Mad River terrane has been abandoned, 2001), and (5) the Chelan Mountains terrane, dominated by the Chelan Complex of Hopson and Mattinson (1971) which is composed of migmatite and gneissic to tonalite of deep-seated igneous and metamorphic origin.During an episode of Late Cretaceous regional metamorphism, all the terranes were intruded by deepseated tonalite to granodiorite plutons, including the Mount Stuart batholith, Ten Peak and Dirty Face plutons, and the Entiat pluton and massive granitoid rocks of the Chelan Complex. The Duncan Hill pluton intruded rocks of the Chelan Mountains terrane in the Middle Eocene. At about the same time fluvial arkosic sediment of the Chumstick Formation was deposited in a depression. The outpouring of basalt lavas to the southeast of the quadrangle during the Miocene built up the Columbia River Basalt Group. These now slightly warped lavas lapped onto the uplifted older rocks. Deformation, uplift, and erosion recorded in the rocks and deposits of the quadrangle continued into post-Miocene time. Quaternary deposits reflect advances of glaciers down the major valleys, a complicated history of catastrophic glacial floods down the Columbia River, the formation of lakes in the Columbia and Wenatchee river valleys by landslides and flood backwaters, and hillslope erosion by large and small landslides and debris flows.

Geomorphic responses of lower Bega River to catchment disturbance, 1851?1926

NASA Astrophysics Data System (ADS)

Brooks, Andrew P.; Brierley, Gary J.

1997-03-01

Prior to significant European settlement of the area in the 1850s, lower Bega River on the South Coast of NSW had a narrow, relatively deep channel lined by river oaks. The river had a suspended or mixed load, with platypus habitat available in pools. Banks were fine-grained and relatively cohesive (silts and clays), as was the floodplain, which graded to a series of valley-marginal swamps and lakes. Extensive evidence from maps and portion plans, archival photographs, bridge surveys, and anecdotal sources, complemented by field analysis of floodplain sedimentology (including radiocarbon-dated samples) and vegetation remnants are used to document the dramatic metamorphosis in the character and behaviour of lower Bega River in the latter half of the nineteenth century. By 1926 the channel had widened extensively (up to 340%) and shallowed in association with bed aggradation by coarse sandy bedload. Floodplain accretion was dominated by fine to medium sands, with some coarse sand splays. In contrast with most other studies of channel metamorphosis in Australia, which have emphasised river responses to climatically-induced flood histories, relegating human impacts to a secondary role, the profound changes to the geomorphic condition and behaviour of Bega River reflect indirect human disturbance of Bega catchment, and direct but non point source disturbance to the channel. Extensive clearance of catchment, floodplain, and channel-marginal vegetation occurred within a few decades of European settlement, altering the hydrologic and sediment regime of the river, and transforming the geomorphic effectiveness of floods. Although this study is situated in a relatively sensitive, granitic catchment, catchment clearance is likely to have induced equally significant responses in many other river systems in eastern Australia. In some instances the diffuse aspects of human disturbance on landscapes induce impacts on river character that are just as profound as major direct disturbances of river channels. This may have profound implications in understanding, and hence managing, the geomorphic consequences of river behaviour in Australia and elsewhere.

Evolution of Metallic Trace Elements in Contaminated River Sediments: Geochemical Variation Along River Linear and Vertical Profile

NASA Astrophysics Data System (ADS)

Kanbar, Hussein; Montarges-Pelletier, Emmanuelle; Mansuy-Huault, Laurence; Losson, Benoit; Manceau, Luc; Bauer, Allan; Bihannic, Isabelle; Gley, Renaud; El Samrani, Antoine; Kobaissi, Ahmad; Kazpard, Veronique; Villieras, Frédéric

2015-04-01

Metal pollution in riverine systems poses a serious threat that jeopardizes water and sediment quality, and hence river dwelling biota. Since those metallic pollutants can be transported for long distances via river flow, river management has become a great necessity, especially in times where industrial activities and global climate change are causing metal release and spreading (by flooding events). These changes are able to modify river hydrodynamics, and as a consequence natural physico-chemical status of different aquatic system compartments, which in turn alter metal mobility, availability and speciation. Vertical profiles of sediments hold the archive of what has been deposited for several tenths of years, thus they are used as a tool to study what had been deposited in rivers beds. The studied area lies in the Orne river, northeastern France. This river had been strongly modified physically and affected by steelmaking industrial activities that had boosted in the middle of the last century. This study focuses on several sites along the linear of the Orne river, as well as vertical profiles of sediments. Sediment cores were collected at sites where sedimentation is favoured, and in particular upstream two dams, built in the second half of the XXth century for industrial purposes. Sediment cores were sliced into 2-5cm layers, according to suitability, and analysed for physical and physico-chemical properties, elemental content and mineralogy. Data of the vertical profile in a sediment core is important to show the evolution of sediments as a function of depth, and hence age, in terms of nature, size and constituents. The physical properties include particle size distribution (PSD) and water content. In addition, the physico-chemical properties, such as pH and oxido-reduction potential (ORP) of interstitial water from undisturbed cores were also detected. Total elemental content of sediment and available ones of extracted interstitial waters was detected using ICP-MS and ICP-OES for trace and major elements respectively. Well crystallized minerals were detected by X-Ray Diffraction (XRD), while amorphous and poorly crystallized phases were identified with scanning and transmission electron microscope (SEM and TEM respectively), combined with Energy Dispersive X-Ray Spectroscopy (EDXS). Such microscopic techniques also provided information about metal carriers. To have an insight about the metal speciation at molecular level, X-Ray Absorption spectroscopy (XAS) was performed at Zn K-edge. The first analyses of Orne sediment cores evidenced different particle size distribution and sediment consolidation levels. Yet the cores showed that below a layer of apparently recent sediments (about 10-20 cm), lie highly contaminated ones. Zn and Pb content in deep sediment layers reach several thousands ppm, where they appeared mainly as Zn and Pb sulphides. Also, the high content of iron in deep sediments resulted in the presence of different iron phases: hematite, wuestite, magnetite, goethite, sulphides (pyrite), as well as undefined iron-silicate. In addition, interstitial waters contained high values of available metals (Zn: 500-35000 ppm, Pb: 150-5700 ppm, Cd: 1-10ppm), which might cause a greater concern than solid-bound metals, especially when river bed sediments are disturbed.

Geochemistry of the Onyx River (Wright Valley, Antarctica) and its role in the chemical evolution of Lake Vanda

NASA Astrophysics Data System (ADS)

Green, William J.; Canfield, Donald E.

1984-12-01

The Onyx River (Wright Valley, Antarctica) is a dilute meltwater stream originating in the vicinity of the Wright Lower Glacier. It acquires a significant fraction of its salt content when glacial meltwaters contact Wright Valley soils at Lake Brownworth and the concentrations of all ions increase with distance along the 28-km channel down to Lake Vanda. Average millimolar concentrations of major ions at the Vanda weir during the 1980-1981 flow season were: Ca = 0.119; Mg = 0.061; Na = 0.212; K = 0.033; Q = 0.212; SO4 = 0.045; HCO3 = 0.295; and SiO2 = 0.049. Based on the flow measurements of Chinn (1982), this amounts to an annual flux (in moles) to Lake Vanda of: Ca = 0.238 × 10 6; Mg = 0.122 × 10 6; Na = 0.424 × 10 6; K = 0.066 × 10 6; Cl = 0.424 × 10 6; SO4 = 0.09 × 10 6; HCO3 = 0.59 × 10 6; SiO2 = 0.098 × 10 6. In spite of the large salt input from this source, equilibrium evaporation of Onyx River water would have resulted in early calcite deposition and in the formation of a Na-Mg-Cl-HCO 3 brine rather than in the Ca-Na-Mg-Cl waters observed in Lake Vanda. The river alone could not have produced a brine having the qualitative geochemical features of the lower saline waters of Lake Vanda. It is proposed that the Vanda brine is instead the result of past ( > 1200 yrs BP) mixing events between Onyx River inflows and calcium chloride-rich deep groundwaters derived from the Don Juan Basin. The mixing model presented here shows that the Onyx River is the major contributor of K, HCO 3, SO 4, and (possibly) Mg found in the lake and a significant contributor (approximately one half) of the observed Na. Calcium and Cl, on the other hand, came largely from deep groundwater sources in the Don Juan Basin. All concentrations except Mg are well predicted by this model. The chemical composition of the geologically recent upper lake is explained in terms of ionic diffusion from the pre-formed brine, coupled with Onyx River inflow. Ionic ratios calculated from this latter model are in very good agreement with those observed in the lake at 35 meters.

Fish depth distributions in the Lower Mississippi River

USGS Publications Warehouse

Killgore, K. J.; Miranda, Leandro E.

2014-01-01

A substantial body of literature exists about depth distribution of fish in oceans, lakes and reservoirs, but less is known about fish depth distribution in large rivers. Most of the emphasis on fish distributions in rivers has focused on longitudinal and latitudinal spatial distributions. Knowledge on depth distribution is necessary to understand species and community habitat needs. Considering this void, our goal was to identify patterns in fish benthic distribution along depth gradients in the Lower Mississippi River. Fish were collected over 14 years in depths down to 27 m. Fish exhibited non-random depth distributions that varied seasonally and according to species. Species richness was highest in shallow water, with about 50% of the 62 species detected no longer collected in water deeper than 8 m and about 75% no longer collected in water deeper than 12 m. Although richness was highest in shallow water, most species were not restricted to shallow water. Rather, most species used a wide range of depths. A weak depth zonation occurred, not as strong as that reported for deep oceans and lakes. Larger fish tended to occur in deeper water during the high-water period of an annual cycle, but no correlation was evident during the low-water period. The advent of landscape ecology has guided river research to search for spatial patterns along the length of the river and associated floodplains. Our results suggest that fish assemblages in large rivers are also structured vertically. 

Factors affecting the occurrence of saugers in small, high-elevation rivers near the western edge of the species' natural distribution

USGS Publications Warehouse

Amadio, C.J.; Hubert, W.A.; Johnson, Kevin; Oberlie, D.; Dufek, D.

2005-01-01

Factors affecting the occurrence of saugers Sander canadensis were studied throughout the Wind River basin, a high-elevation watershed (> 1,440 m above mean sea level) on the western periphery of the species' natural distribution in central Wyoming. Adult saugers appeared to have a contiguous distribution over 170 km of streams among four rivers in the watershed. The upstream boundaries of sauger distribution were influenced by summer water temperatures and channel slopes in two rivers and by water diversion dams that created barriers to upstream movement in the other two rivers. Models that included summer water temperature, maximum water depth, habitat type (pool or run), dominant substrate, and alkalinity accounted for the variation in sauger occurrence across the watershed within the areas of sauger distribution. Water temperature was the most important basin-scale habitat feature associated with sauger occurrence, and maximum depth was the most important site-specific habitat feature. Saugers were found in a larger proportion of pools than runs in all segments of the watershed and occurred almost exclusively in pools in upstream segments of the watershed. Suitable summer water temperatures and deep, low-velocity habitat were available to support saugers over a large portion of the Wind River watershed. Future management of saugers in the Wind River watershed, as well as in other small river systems within the species' native range, should involve (1) preserving natural fluvial processes to maintain the summer water temperatures and physical habitat features needed by saugers and (2) assuring that barriers to movement do not reduce upstream boundaries of populations.

Factors affecting stranding of juvenile salmonids by wakes from ship passage in the Lower Columbia River

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

Pearson, Walter H.; Skalski, John R.

2011-09-01

The effects of deep-draft vessel traffic in confined riverine channels on shorelines and fish are of widespread concern. In the Pacific Northwest of the United States, wakes and subsequent beach run-up from ships transiting the Lower Columbia River have been observed to strand juvenile salmon and other fish. As part of a before-and-after study to assess stranding effects that may be associated with channel deepening, we measured 19 co-variables from observations of 126 vessel passages at three low-slope beaches and used multiple logistic regression to discern the significant factors influencing the frequency of stranding. Subyearling Chinook salmon were 82% ofmore » the fish stranded over all sites and seasons. Given a low-slope beach, stranding frequencies for juvenile salmon were significantly related to river location, salmon density in the shallows, a proxy for ship kinetic energy, tidal height, and two interactions. The beach types selected for our study do not include all the beach types along the Lower Columbia River so that the stranding probabilities described here cannot be extrapolated river-wide. A more sophisticated modeling effort, informed by additional field data, is needed to assess salmon losses by stranding for the entire lower river. Such modeling needs to include river-scale factors such as beach type, berms, proximity to navigation channel, and perhaps, proximity to tributaries that act as sources of out-migrating juvenile salmon. At both river and beach scales, no one factor produces stranding; rather interactions among several conditions produce a stranding event and give stranding its episodic nature.« less

Stratigraphic evidence for the role of lake spillover in the inception of the lower Colorado River in southern Nevada and western Arizona

USGS Publications Warehouse

House, P.K.; Pearthree, P.A.; Perkins, M.E.

2008-01-01

Late Miocene and early Pliocene sediments exposed along the lower Colorado River near Laughlin, Nevada, contain evidence that establishment of this reach of the river after 5.6 Ma involved flooding from lake spillover through a bedrock divide between Cottonwood Valley to the north and Mohave Valley to the south. Lacustrine marls interfingered with and conformably overlying a sequence of post-5.6 Ma finegrained valley-fill deposits record an early phase of intermittent lacustrine inundation restricted to Cottonwood Valley. Limestone, mud, sand, and minor gravel of the Bouse Formation were subsequently deposited above an unconformity. At the north end of Mohave Valley, a coarse-grained, lithologically distinct fluvial conglomerate separates subaerial, locally derived fan deposits from subaqueous deposits of the Bouse Formation. We interpret this key unit as evidence for overtopping and catastrophic breaching of the paleodivide immediately before deep lacustrine inundation of both valleys. Exposures in both valleys reveal a substantial erosional unconformity that records drainage of the lake and predates the arrival of sediment of the through-going Colorado River. Subsequent river aggradation culminated in the Pliocene between 4.1 and 3.3 Ma. The stratigraphic associations and timing of this drainage transition are consistent with geochemical evidence linking lacustrine conditions to the early Colorado River, the timings of drainage integration and canyon incision on the Colorado Plateau, the arrival of Colorado River sand at its terminus in the Salton Trough, and a downstream-directed mode of river integration common in areas of crustal extension. ?? 2008 The Geological Society of America.

[Study on the present status of the areas with high iodine concentration in drinking water and edible salt at household levels in Ohio of Yellow River].

PubMed

Guo, Xiao-wei; Zhai, Li-ping; Liu, Yuan; Wang, Xin

2005-11-01

To understand the present condition of iodine excess areas and edible salt at household levels in Ohio of Yellow River,which will provide the evidence to control it. A cross section in one time was adopted for the epidemiological survey based on the east, west, south, north and central in all of townships from 8 counties. 2 samples of drinking water from each village were tested their water iodine content as well as the data regarding to their recourses and the depth of wells. 5 samples of edible salt were collected from each village for quantitative analysis. We investigated 451 villages in 92 townships of 8 counties. 800 samples of drinking water were tested which values of iodine content were (110.93 +/- 152.26) microg/L in main, 55.83 microg/L (0.84 - 997.82 microg/L) in medium. 102.39 thousand population are at risk for iodine excess and living in 24 townships of 7 counties where iodine concentration is over 150 microg/L in drinking water, with (327.72 +/- 192.19) microg/L in mean value or 253.87 microg/L (150.78 - 997.82 microg/L) in medium. The rate of iodized salt is 97.2%. All the iodine excess areas are located in alluvial plain of Yellow River. The etiology of high iodine in shallow well water may be supposed to be iodine aggregation formed by Yellow River in terms of thousands of flood in thousands of years. But iodine excess in deep well water may be related to rotten, deposit marine living beings rich in iodine millions upon millions years ago. There were distinctive features of iodine excess in drinking water from both shallow well and deep well, 24 iodine excess areas in Ohio of Yellow River. It has suggested that iodized salt intervention should be stopped in the areas and starting the health education project, survey of iodized salt in the region.

Some new cave diving exploration results from Croatian karst area

NASA Astrophysics Data System (ADS)

Garasic, Davor; Garasic, Mladen

2017-04-01

In the recent years, several international cave diving expeditions took place in the Dinaric karst of Croatia. The objectives were conducting a new research of previously known karstic springs and also exploring new ones. The deepest karst cave in Croatia filled with water is Crveno jezero (lake) near Imotski town, with water depth of 281 meters and total cave depth of 528 meters. Volume of water in this cave is about 16 millions m3. Diving expeditions were held in 1997 and 1998.The deepest karst spring in the Dinaric karst of Croatia is Vrelo of Una River (with max discharge about 100 m3/s), where divers measured depth of -248 meters. Explorations were made in 2007 and 2016. Sinac spring in Pla\\vsko Polje has been dived to the depth of -203 meters. Cave diving was done in 1984, 1999, 2003, 2007 - 2016. Furthermore, very popular springs of the river Kupa (-155 m) in Gorski Kotar (explored since1995 till 2015), river Gacka (-105 in depth, 1150m in length) in Lika, explored from 1992 to 2016, river Cetina (-110 m in depth, 1300 m in length), cave diving explored from 2000 to 2016 in the Dalmatinska Zagora, Rumin Veliki spring (- 150 m in depth) in the Sinjska Krajina (explored and dived in 2006 and 2010), than rivers Krnjeza and Krupa in Ravni kotari with diving depths of over 100 meters (in 2004 and 2005) and so on. Along the Adriatic coast in Croatia there are many deep and long submarine springs (vrulje), ie. caves under seawater springs. called - vruljas for example Vrulja Zecica with over 900 meters ine length and Vrulja Modrič with completely flooded cave channels that extend over 2300 meters in length. Cave diving was conducted from 2010 to 2016. Vrulja Dubci is also worth mentioning (dived and explored in 2000), 161 meters deep and so on. Tectonic activity plays a dominant role in the creation and function of these caves. Geological, hydrogeological and lithostratigraphic conditions are also very important in speleogenesis of these caves in Croatian karst system.

Aerial gamma ray and magnetic survey, Powder River II Project: the Newcastle and Gillette Quadrangles of Wyoming and South Dakota; the Ekalaka Quadrangle of Montana, South and North Dakota. Volume I. Final report

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

Not Available

1979-04-01

During the months of August through September 1978, geoMetrics, Inc. flew approximately 9000 line miles of high sensitivity airborne radiometric and magnetic data in eastern Wyoming and southern Montana over three 1/sup 0/ x 2/sup 0/ NTMS quadrangle (Newcastle, Gillette, and Ekalaka) as part of the Department of Energy's National Uranium Resource Evaluation program. All radiometric and magnetic data were fully reduced and interpreted by geoMetrics, and are presented as four volumes (one Volume I and three Volume II's) in this report. The survey area lies entirely within the northern Great Plains Physiographic Province. The deep Powder River Basin andmore » the Black Hills Uplift are the two dominant structures in the area. Both structures strike NNW approximately parallel to each other with the Powder River Basin to the west of the Uplift. The Basin is one of the largest and deepest in the northern Great Plains and contains over 17,000 feet of Phanerozoic sediments at its deepest point. Economic deposits of oil, coal, bentonite and uranium are found in the Tertiary and/or Cretaceous rocks of the Basin. Gold, silver, lead, copper, manganese, rare-earth elements and uranium have been mined in the Uplift. Epigenetic uranium deposits lie primarily in the Monument Hills - Box Creek and Pumpkin Buttes - Turnercrest districts within arkosic sandstones of the Paleocene Fort Union Formation. A total of 368 groups of statistical values in the uranium window meet the criteria for valid anomalies and are discussed in the interpretation sections (83 in Newcastle, 109 in Gillette, and 126 in Ekalaka). Most anomalies lie in the Tertiary sediments of the Powder River Basin, but only a few are clearly related to known uranium mines or prospects. Magnetic data generally delineate the deep Powder River Basin relative to the Black Hills Uplift. Higher frequency anomalies appear related to producing oil fields and mapped sedimentary structures.« less

Using Deep Learning to Assess Future Flood Magnitude and Frequency in the Semi-arid and Snowmelt-dominated Missouri River Headwater Catchments

NASA Astrophysics Data System (ADS)

Francois, B.; Wi, S.; Brown, C.

2017-12-01

There has been growing interest for hydrologists and water resources managers about the emergence of non-stationarities associated with the hydro-meteorological processes driving floods. Among the potential causes of non-stationarity, climate change is deemed a major one. Understanding the effects of climate change on hydrological regimes of the Missouri River is challenging. In this region, floods are mainly triggered by snow melting, either when temperatures get mild in spring/summer, or when rain falls over snow in early spring and fall. The sparsely gauged and topographically complex area degrades the value of hydrological modeling that otherwise might foreshadow the evolution of hydro-meteorological interactions between precipitation, temperature and snow. In this work, we explore the utility of Deep Learning (DL) for assessing flood magnitude change under climate change. By using multiple hidden layers within artificial neural networks (ANNs), DL allows modeling complex interactions between inputs (i.e. precipitation, temperature and snow water equivalent) and outputs (i.e. water discharge). The objective is to develop a parsimonious model of the flood processes that maintain the contribution of nonstationary factors and their potential evolution under climate change, while reducing extraneous factors not central to flood generation. By comparing ANN's performance with outputs from two hydrological models of differing complexity (i.e. VIC, SAC-SMA), we evaluate the modeling capability of ANNs for three snow-dominated catchments that represent different flood regimes (Yellowstone River at Billings (MT; USGS 06214500), Powder River near Locate (MT; USGS 06326500) and James River near Scotland (SD; USGS 06478500)). Nonstationary inputs for each flood process model are derived from dynamically downscaled climate projections (from the NARCCAP experiment) to project floods in the three selected catchments. The uncertainty of future snow projections as well as its impact on spring flooding are explored. Future flood frequency obtained with ANNs is compared with the one obtained thanks to hydrological models and with the traditional approach as described in Bulletin 17C. Keywords: Flood, Climate-change, Snow, Neural Networks

Water Quality in the Equus Beds Aquifer and the Little Arkansas River Before Implementation of Large-Scale Artificial Recharge, South-Central Kansas, 1995-2005

USGS Publications Warehouse

Ziegler, Andrew C.; Hansen, Cristi V.; Finn, Daniel A.

2010-01-01

Artificial recharge of the Equus Beds aquifer using runoff from the Little Arkansas River in south-central Kansas was first proposed in 1956 and was one of many options considered by the city of Wichita to preserve its water supply. Declining aquifer water levels of as much as 50 feet exacerbated concerns about future water availability and enhanced migration of saltwater into the aquifer from past oil and gas activities near Burrton and from the Arkansas River. Because Wichita changed water-management strategies and decreased pumping from the Equus Beds aquifer in 1992, water storage in the aquifer recovered by about 50 percent. This recovery is the result of increased reliance on Cheney Reservoir for Wichita water supply, decreased aquifer pumping, and larger than normal precipitation. Accompanying the water-level recovery, the average water-level gradient in the aquifer decreased from about 12 feet per mile in 1992 to about 8 feet per mile in January 2006. An important component of artificial recharge is the water quality of the receiving aquifer and the water being recharged (source water). Water quality within the Little Arkansas River was defined using data from two real-time surface-water-quality sites and discrete samples. Water quality in the Equus Beds aquifer was defined using sample analyses collected at 38 index sites, each with a well completed in the shallow and deep parts of the Equus Beds aquifer. In addition, data were collected at diversion well sites, recharge sites, background wells, and prototype wells for the aquifer storage and recovery project. Samples were analyzed for major ions, nutrients, trace metals, radionuclides, organic compounds, and bacterial and viral indicators. Water-quality constituents of concern for artificial recharge are those constituents that frequently (more than 5 percent of samples) may exceed Federal [U.S. Environmental Protection Agency (USEPA)] and State drinking-water criteria in water samples from the receiving aquifer or in samples from the source water. Constituents of concern include major ions (sulfate and chloride), nutrients (nitrite plus nitrate), trace elements (arsenic, iron, and manganese), organic compounds (atrazine), and fecal bacterial indicators. This report describes the water quality in the Equus Beds aquifer and the Little Arkansas River from 1995 through 2005 before implementation of large-scale recharge activities. Sulfate concentrations in water samples from the Little Arkansas River rarely exceeded Federal secondary drinking water regulation (SDWR) of 250 milligrams per liter (mg/L). Sulfate concentrations in groundwater were exceeded in about 18 percent of the wells in the shallow (less than or equal to 80 feet deep) parts of the aquifer and in about 13 percent of the wells in the deep parts the aquifer. Larger sulfate concentrations were associated with parts of the aquifer with the largest water-level declines. Water-quality changes in the Equus Beds aquifer likely were caused by dewatering and oxidation of aquifer material that subsequently resulted in increased sulfate concentrations as water levels recovered. The primary sources of chloride to the Equus Beds aquifer are from past oil and gas activities near Burrton and from the Arkansas River. Computed chloride concentrations in the Little Arkansas River near Halstead exceeded the Federal SDWR of 250 mg/L about 27 percent of the time (primarily during low-flow conditions). Chloride concentrations in groundwater exceeded 250 mg/L in about 8 percent or less of the study area, primarily near Burrton and along the Arkansas River. Chloride in groundwater near Burrton has migrated downgradient about 3 miles during the past 40 to 45 years. The downward and horizontal migration of the chloride is controlled by the hydraulic gradient in the aquifer, dispersion of chloride, and discontinuous clay layers that can inhibit further downward migration. Chloride in the shallow parts of the Equus Beds

In-situ and Land-Based Remote Sensing of River Inlets and Their Interaction with Coastal Waters

DTIC Science & Technology

2013-09-30

CDIP buoy 190 was reporting the impending waves having a 1 meter significant wave height, 7.7s peak period, from 129 degrees. Using the X-Band...spectral energy along a shifted dispersion relationship curve. In deep water, the waves reported by CDIP buoy 190 would have a wavenumber of 0.068 rad/m

33 CFR 165.122 - Regulated Navigation Area: Navigable waters within Narragansett Bay and the Providence River...

Code of Federal Regulations, 2010 CFR

2010-07-01

... navigation area (RNA). The Regulated Navigation Area (RNA) encompasses all of the navigable waters of...) Regulations. (1) All commercial vessels must: (i) Maintain a minimum 10% of the vessel's draft as an under... commercial vessel traffic in all locations within this RNA shall keep out of the way of the oncoming deep...

33 CFR 165.122 - Regulated Navigation Area: Navigable waters within Narragansett Bay and the Providence River...

Code of Federal Regulations, 2013 CFR

2013-07-01

... navigation area (RNA). The Regulated Navigation Area (RNA) encompasses all of the navigable waters of...) Regulations. (1) All commercial vessels must: (i) Maintain a minimum 10% of the vessel's draft as an under... commercial vessel traffic in all locations within this RNA shall keep out of the way of the oncoming deep...

33 CFR 165.122 - Regulated Navigation Area: Navigable waters within Narragansett Bay and the Providence River...

Code of Federal Regulations, 2014 CFR

2014-07-01

... navigation area (RNA). The Regulated Navigation Area (RNA) encompasses all of the navigable waters of...) Regulations. (1) All commercial vessels must: (i) Maintain a minimum 10% of the vessel's draft as an under... commercial vessel traffic in all locations within this RNA shall keep out of the way of the oncoming deep...

33 CFR 165.122 - Regulated Navigation Area: Navigable waters within Narragansett Bay and the Providence River...

Code of Federal Regulations, 2011 CFR

2011-07-01

... navigation area (RNA). The Regulated Navigation Area (RNA) encompasses all of the navigable waters of...) Regulations. (1) All commercial vessels must: (i) Maintain a minimum 10% of the vessel's draft as an under... commercial vessel traffic in all locations within this RNA shall keep out of the way of the oncoming deep...

33 CFR 165.122 - Regulated Navigation Area: Navigable waters within Narragansett Bay and the Providence River...

Code of Federal Regulations, 2012 CFR

2012-07-01

... navigation area (RNA). The Regulated Navigation Area (RNA) encompasses all of the navigable waters of...) Regulations. (1) All commercial vessels must: (i) Maintain a minimum 10% of the vessel's draft as an under... commercial vessel traffic in all locations within this RNA shall keep out of the way of the oncoming deep...

Delineation of potential deep seated landslides in a watershed using environmental index

NASA Astrophysics Data System (ADS)

Lai, Siao Ying; Lin, Chao Yuan; Lin, Cheng Yu

2016-04-01

The extreme rainfall induced deep seated landslides cause more attentions recently. Extreme rainfall can accelerate soil moisture content and surface runoff in slopeland which usually results in severe headward erosion and slope failures in an upstream watershed. It's a crucial issue for disaster prevention to extract the sites of potential deep seated landslide dynamically. Landslide risk and scale in a watershed were well discussed in this study. Risk of landslide occurrence in a watershed can be calculated from the multiplication of hazard and vulnerability for a certain event. A synthesis indicator derived from the indices of inverted extreme rainfall, road development and inverted normalized difference vegetation index can be effectively used as vulnerability for a watershed before the event. Landslide scale estimated from the indices of soil depth, headward erosion, river concave and dip slope could be applied to locate the hotspots of deep seated landslide in a watershed. The events of Typhoon Morakot in 2009 and Soudelor in 2015 were also selected in this study to verify the delineation accuracy of the model for the references of related authorities.

Geomorphology of the Burnt River, eastern Oregon, USA: Topographic adjustments to tectonic and dynamic deformation

NASA Astrophysics Data System (ADS)

Morriss, Matthew Connor; Wegmann, Karl W.

2017-02-01

Eastern Oregon contains the deepest gorge in North America, where the Snake River cuts vertically down 2300 m. This deep gorge is known as Hells Canyon. A landscape containing such a topographic feature is likely undergoing relatively recent deformation. Study of the Burnt River, a tributary to the Snake River at the upstream end of Hells Canyon, yields data on active river incision in eastern Oregon, indicating that Quaternary faults are a first order control on regional landscape development. Through 1:24,000-scale geologic mapping, a 500,000-year record of fluvial incision along the Burnt River was constructed and is chronologically anchored by optically stimulated luminescence dating and tephrochronology analyses. A conceptual model of fluvial terrace formation was developed using these ages and likely applies to other non-glaciated catchments in eastern Oregon. Mapped terraces, inferred to have formed during glacial-interglacial cycles, provide constraints on rates of incision of the Burnt River. Incision through these terraces indicates that the Burnt River is down-cutting at 0.15 to 0.57 m kyr- 1. This incision appears to reflect a combination of local base-level adjustments tied to movement along the newly mapped Durkee fault and regional base-level control imposed by the downcutting of the Snake River. Deformation of terraces as young as 38.7 ± 5.1 ka indicates Quaternary activity along the Durkee fault, and when combined with topographic metrics (slope, relief, hypsometry, and stream-steepness), reveals a landscape in disequilibrium. Longer wavelength lithospheric dynamics (delamination and crustal foundering) that initiated in the Miocene may also be responsible for continued regional deformation of the Earth's surface.

Diazotrophy in the Deep: An analysis of the distribution, magnitude, geochemical controls, and biological mediators of deep-sea benthic nitrogen fixation

NASA Astrophysics Data System (ADS)

Dekas, Anne Elizabeth

Biological nitrogen fixation (the conversion of N2 to NH3) is a critical process in the oceans, counteracting the production of N2 gas by dissimilatory bacterial metabolisms and providing a source of bioavailable nitrogen to many nitrogen-limited ecosystems. One currently poorly studied and potentially underappreciated habitat for diazotrophic organisms is the sediments of the deep-sea. Although nitrogen fixation was once thought to be negligible in non-photosynthetically driven benthic ecosystems, the present study demonstrates the occurrence and expression of a diversity of nifH genes (those necessary for nitrogen fixation), as well as a widespread ability to fix nitrogen at high rates in these locations. The following research explores the distribution, magnitude, geochemical controls, and biological mediators of nitrogen fixation at several deep-sea sediment habitats, including active methane seeps (Mound 12, Costa Rica; Eel River Basin, CA, USA; Hydrate Ridge, OR, USA; and Monterey Canyon, CA, USA), whale-fall sites (Monterey Canyon, CA), and background deep-sea sediment (off-site Mound 12 Costa Rica, off-site Hydrate Ridge, OR, USA; and Monterey Canyon, CA, USA). The first of the five chapters describes the FISH-NanoSIMS method, which we optimized for the analysis of closely associated microbial symbionts in marine sediments. The second describes an investigation of methane seep sediment from the Eel River Basin, where we recovered nifH sequences from extracted DNA, and used FISH-NanoSIMS to identify methanotrophic archaea (ANME-2) as diazotrophs, when associated with functional sulfate-reducing bacterial symbionts. The third and fourth chapters focus on the distribution and diversity of active diazotrophs (respectively) in methane seep sediment from Mound 12, Costa Rica, using a combination of 15N-labeling experiments, FISH-NanoSIMS, and RNA and DNA analysis. The fifth chapter expands the scope of the investigation by targeting diverse samples from methane seep, whale-fall, and background sediment collected along the Eastern Pacific Margin, and comparing the rates of nitrogen fixation observed to geochemical measurements collected in parallel. Together, these analyses represent the most extensive investigation of deep-sea nitrogen fixation to date, and work towards understanding the contribution of benthic nitrogen fixation to global marine nitrogen cycling.

Video-Based Electroshocking Platform to Identify Lamprey Ammocoete Habitats: Field Validation and New Discoveries in the Columbia River Basin

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

Arntzen, Evan V.; Mueller, Robert P.

A deep water electroshocking platform (DEP), developed to characterize larval lampreys (ammocoetes) and associated habitat in depths up to 15 m, was recently tested in the field. The DEP samples 0.55 m2∙min-1 without requiring ammocoete transport to the surface. Searches were conducted at a known rearing location (mouth of the Wind River, WA) and at locations on the Cowlitz River, WA, where ammocoetes had not previously been found. At the mouth of the Wind River, video imaged ammocoetes ranged from 50 to 150 mm in water depths between 1.5 m and 4.5 m and were more common in sediments containingmore » organic silt. Ammocoetes (n=137) were detected at 61% of locations sampled (summer) and 50% of the locations sampled (winter). Following the field verification, the DEP was used on the lower 11.7 km of the Cowlitz River, WA. Ammocoetes (n=41) were found with a detection rate of 26% at specific search locations. Cowlitz River sediment containing ammocoetes was also dominated by silt with organic material, often downstream of alluvial bars in water depths from 0.8 to 1.7 m. Test results indicated a high sampling efficiency, favorable detection rates, and little or no impact to ammocoetes and their surrounding benthic environments.« less

Evaluating lake stratification and temporal trends by using near-continuous water-quality data from automated profiling systems for water years 2005-09, Lake Mead, Arizona and Nevada

USGS Publications Warehouse

Veley, Ronald J.; Moran, Michael J.

2012-01-01

The U.S. Geological Survey, in cooperation with the National Park Service and Southern Nevada Water Authority, collected near-continuous depth-dependent water-quality data at Lake Mead, Arizona and Nevada, as part of a multi-agency monitoring network maintained to provide resource managers with basic data and to gain a better understanding of the hydrodynamics of the lake. Water-quality data-collection stations on Lake Mead were located in shallow water (less than 20 meters) at Las Vegas Bay (Site 3) and Overton Arm, and in deep water (greater than 20 meters) near Sentinel Island and at Virgin and Temple Basins. At each station, near-continual depth-dependent water-quality data were collected from October 2004 through September 2009. The data were collected by using automatic profiling systems equipped with multiparameter water-quality sondes. The sondes had sensors for temperature, specific conductance, dissolved oxygen, pH, turbidity, and depth. Data were collected every 6 hours at 2-meter depth intervals (for shallow-water stations) or 5-meter depth intervals (for deep-water stations) beginning at 1 meter below water surface. Data were analyzed to determine water-quality conditions related to stratification of the lake and temporal trends in water-quality parameters. Three water-quality parameters were the main focus of these analyses: temperature, specific conductance, and dissolved oxygen. Statistical temporal-trend analyses were performed for a single depth at shallow-water stations [Las Vegas Bay (Site 3) and Overton Arm] and for thermally-stratified lake layers at deep-water stations (Sentinel Island and Virgin Basin). The limited period of data collection at the Temple Basin station prevented the application of statistical trend analysis. During the summer months, thermal stratification was not observed at shallow-water stations, nor were major maxima or minima observed for specific-conductance or dissolved-oxygen profiles. A clearly-defined thermocline and well-defined maxima and minima in specific-conductance and dissolved-oxygen profiles were observed at deep-water stations during the summer months. Specific-conductance maxima were likely the result of inflow of water from either the Las Vegas Wash or Muddy/Virgin Rivers or both, while the minima were likely the result of inflow of water from the Colorado River. Maxima and minima for dissolved oxygen were likely the result of primary productivity blooms and their subsequent decay. Temporal-trend analyses indicated that specific conductance decreased at all stations over the period of record, except for Las Vegas Bay (Site 3), where specific conductance increased. Temperature also decreased over the period of record at deep-water stations for certain lake layers. Decreasing temperature and specific conductance at deep-water stations is the result of decreasing values in these parameters in water coming from the Colorado River. Quagga mussels (Dreissena rostriformis bugensis), however, could play a role in trends of decreasing specific conductance through incorporation of calcite in their shells. Trends of decreasing turbidity and pH at deep-water stations support the hypothesis that quagga mussels could be having an effect on the physical properties and water chemistry of Lake Mead. Unlike other stations, Las Vegas Bay (Site 3) had increasing specific conductance and is interpreted as the result of lowering lake levels decreasing the volume of lake water available for mixing and dilution of the high-conductance water coming from Las Vegas Wash. Dissolved oxygen increased over the period of record in some lake layers at the deep-water stations. Increasing dissolved oxygen at deep-water stations is believed to result, in part, from a reduction of phosphorus entering Lake Mead and the concomitant reduction of biological oxygen demand.

History of Snake River Canyon Indicated by Revised Stratigraphy of Snake River Group Near Hagerman and King Hill, Idaho: With a Section on Paleomagnetism

USGS Publications Warehouse

Malde, Harold E.; Cox, Allan

1971-01-01

A discovery that debris left by the Bonneville Flood (Melon Gravel) overlies McKinney Basalt about 200 feet above the Snake River near King Hill requires that the stratigraphy of the Snake River Group be revised. In former usage, the McKinney Basalt and its immediately older companion, the Wendell Grade Basalt, were considered on the basis of equivocal field relations to be younger than the Melon Gravel and were assigned to the Recent. These lava flows are here reclassified as Pleistocene. The Bancroft Springs Basalt, which consists of both subaerial lava and pillow lava in a former Snake River canyon, was previously separated from the McKinney but is now combined with the McKinney. Accordingly, the name Bancroft Springs Basalt is here abandoned. This revised stratigraphy is first described from geomorphic relations of the McKinney Basalt near King Hill and is then discussed in the light of drainage changes caused by local lava flows during entrenchment of the Snake River. Near King Hill, a former Snake River canyon was completely filled by McKinney Basalt at the place called Bancroft Springs, hut the depth of this lava in the next several miles of the canyon downstream (along a route that approximately coincides with the present canyon) steadily decreased. This ancestral geomorphology is inferred from the former canyon route and, also, from the continuity in gradient of the McKinney lava surface downstream from Bancroft Springs. The drainage history recorded by various lava flows and river deposits of the Snake River Group indicates that the McKinney and Wendell Grade Basalts erupted after the Snake River canyon had reached its present depth of about 500 feet. The Snake River of that time, as far downstream as Bliss, flowed approximately along its present route. The Wood River of that time, however, skirted the north flank of Gooding Butte and joined the ancestral Snake at a junction, now concealed by lava, north of the present canyon about 3 miles west of Bliss. From that place the former Snake River canyon, also now concealed by lava, continued west to Bancroft Springs and thence along a route close to the present canyon to King Hill. To become entrenched in a canyon 500 feet deep, the Snake River downstream from Hagerman became progressively more incised while its upstream route was pushed south in several earlier canyons by intermittent lava flows. Distinctive gravel deposits help to establish the episodes of progressive canyon cutting and to determine the routes of ancestral drainage, including the former position of the Wood River. As canyon cutting continued, springs began to emerge where lavas had filled the earlier canyons. When the Snake River canyon eventually attained its approximate present depth, the Wendell Grade Basalt erupted near Shoshone and, as several tongues, spread west to the canyon rim opposite Hagerman. One tongue crossed the future route of the Wood River, and another covered an upland area of Sand Springs Basalt that had previously reached the canyon floor at Hagerman. The McKinney Basalt then erupted from McKinney Butte northeast of Bliss and spread southward as a subaerial flow, covering part of the Wendell Grade Basalt. It filled the ancestral Wood River canyon and the Snake River canyon of that time west of Bliss as far downstream as King Hill. The resulting dam of lava impounded a deep lake, which extended upstream in the canyon beyond Hagerman. Copious amounts of the McKinney spilled into this temporary lake and produced pillow lava. About 2 miles west of Bliss, pillow lava 500 feet thick completely fills the former canyon and is protected by rimrock of the subaerial McKinney Basalt. From Bliss, the pillow facies extends upstream as far as the McKinney rimrock - about 5 miles. Eruption of the McKinney Basalt diverted the Wood River to a course along the southeast edge of this lava flow. The temporary lake that was dammed by McKinney Basalt west of Bliss spilled along the sou

Persistent pollution of Warta river catchment with chromium: case study from central Poland

NASA Astrophysics Data System (ADS)

Hermanski, S.; Lukaczynski, I.; Nikiel, G.; Mizera, J.; Dulinski, M.; Kania, J.; Rozanski, K.; Szklarczyk, T.; Wachniew, P.; Witczak, S.; Zurek, A.

2012-04-01

Upper reaches of the Warta river, the third largest river in Poland, are located in a densely populated and industrialized area, with presence of heavy industry going back to the second half of the XIX century. Industrial activities include iron smelters in towns of Częstochowa and Zawiercie, large chemical plants (Rudniki and Aniolow) producing predominantly chromium compounds, paper and textile industry, as well as large number of small enterprises specialized in metal coatings (nickel and chromium). Until the 1960s all the industrial and municipal effluents in the region were discharged into the Warta river and its tributaries. Solid wastes were dumped on the surface, mostly without appropriate cover and isolation. This resulted in progressive contamination of surface waters and groundwater with heavy metals, mostly chromium. The upper reaches of the Warta river are located on top of upper Jurassic Major Groundwater Basin (MGWB 326 which is one of four most important groundwater reservoirs in Poland. Almost all potable water demands in the area (ca. 340,000 inhabitants, 800 factories and enterprises) are covered by MGWB 326 (50 deep wells with the average extraction rate of 57,000 m3/d). As the MGWB 326 is mostly phreatic, it has been recognized since long time that persistent pollution of the upper catchment of the Warta river with heavy metals may pose serious thread to quality of this important groundwater resource. In this presentation we summarize the work carried out to date, focused on characterization of the extent and understanding of the mechanisms of pollution of surface water, sediments and groundwater in MGWB 326 with chromium. Historical monitoring data of the levels of chromium in the Warta river and its tributaries are presented, supplemented by the results of measurements of Cr loads in Warta over-bank deposits and Cr levels in groundwater production wells in the area. Three conceptual models of spreading of chromium in the catchment of Warta river are considered: (i) leaching of Cr from waste dumps and its migration in local circulation systems with typical spatial scales of several hundred meters to single kilometers, (ii) migration of Cr on large distances (tens of kilometers) through regional, deep circulation systems, and (iii) hyporeic transport of Cr deposited in the past in over-bank sediments of the Warta river and its subsequent leaching to groundwater (spatial scales of several hundred meters to single kilometers). These conceptual models are evaluated on the basis of 3D regional flow and transport model, supplemented by environmental tracers data. Acknowledgements. The work was carried out as part of the GENESIS project on groundwater systems (http:/www.thegenesisproject.eu) financed by the European Commission 7FP contract 226536 and the statutory funds of the AGH University of Science and Technology (project No.11.11.140.026 and 11.11.220.01).

Groundwater infiltration from alluvial aquifer into karstic aquifer - case study of recharge from river I\\vska to Ižica karstic springs

NASA Astrophysics Data System (ADS)

Meglič, P.; Brenčič, M.

2012-04-01

River I\\vska and Ižica karstic springs are situated in the central part of Slovenia (approximately 20 km south from city Ljubljana) on southern edge of Barje, a tectonic depression field with mostly Holocene and Pleistocene lacustrine and rivers' sediments. Barje is surrounded with hills, which on the southern part consists mostly of Triassic dolomite and Jurassic limestone as well as the basement of Barje in this area. Recharge area of I\\vska River and Ižica karstic springs is covering around 102 km2 of the southern hilly edge of Barje. I\\vska River is a torrent with springs on Blo\\vska planota and flows towards Barje to the north. River formed deep narrow valley that slightly opens at the beginning of I\\vski Vintgar, where flows on a shallow gravel river bed deposited on karstic aquifer. The valley opens on Ljubljansko Barje at village I\\vska vas. Ižica karstic springs are situated on the contact of karst aquifer and Barje intergranular aquifer east of I\\vska valley. After a big flood event on 18th of September 2010 I\\vska River disappeared in the karstic fissures on the river bottom, near bridge in I\\vska village. One day later infiltration point moved 1070 meters upstream. This extreme event caused around 40% higher base flow discharge of Ižica River and total disappearance of I\\vska River for a few days. The analyzed discharge data in the year 2010 of the I\\vska and Ižica River, gave a new understanding of the discharge of I\\vska River and groundwater flow in the area. Before this extreme event discharge of the I\\vska River was measured at different profiles in the channel and reduction of discharge was observed along the course indicating that I\\vska recharges Ižica springs. Analyses presented were performed in the frame of INCOME project and are aimed to improve understanding of hydrogeological conditions in the catchment area of Barje aquifer which is exploited for the public water supply of Ljubljana.

U.S. Geological Survey common-depth-point seismic-reflection survey between Mississippi River miles 195 to 210 (R/V NEECHO, cruise NE-80-3)

USGS Publications Warehouse

Winget, E.A.; Tirey, G.B.

1984-01-01

In December 1980, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (COE), conducted a seismic survey of the Mississippi River in the vicinity of Alton, Illinois, near St. Louis, Missouri (fig. 1). Seismic lines were run from the mouth of the Missouri River up the Mississippi River to a point approximately seven miles upriver from Lock and Dam No. 26 at Alton, Illinois (fig. 2a,b). Additional lines were run upriver from Lock and Dam No. 25 between the dam and River Mile 244, but these data are not reported because of mechanical problems with the larger sound-source equipment and inexact navigational control. The objective of the cooperative study was to utilize marine common-depth-point (CDP), digital, and multichannel techniques to locate a monoclinal flexure of the Cap au Gres Fault that earlier had been interpreted from land seismic data to be in the vicinity of Lock and Dam No 26 (Shannon and Wilson, 1980). A second objective was to demonstrate that the marine seismic system could be used for making relatively deep penetration seismic-reflection surveys on shallow (less than 10-m water depth) inland waterways that have organic sediment floors.

Trace elements in seep waters along Whitewood Creek, South Dakota, and their toxicity to fathead minnows

USGS Publications Warehouse

Hamilton, S.J.; Buhl, K.J.

2000-01-01

Whitewood Creek, located in the Black Hills of southwestern South Dakota, has a long history of contamination from mining activity. Gold exploration began in the 1870s, and has continued since that time. Whitewood Creek received direct releases of tailings from 1870 to 1977 from Gold Run Creek in Lead, SD. It has been estimated that approximately 100 million to 1 billion tons of mining, milling, and ore processing wastes have been released by mining activity in the last century in to Whitewood Creek, the Belle Fourche river, and the Cheyenne River (Fox Consultants, Inc. 1984). Tailings deposition has altered the geomorphology of Whitewood Creek, and deposits up to 4.6 m. deep, have become stabilized by vegetation. Several other streams in the Black Hills also have been adversely affected by mining operations (Rahn 1996).As water leaches through rock strata that are disturbed by surface and subsurface mining, it dissolves inorganic elements and carries them to the groundwater.  Groundwater movement through the extensive tailings deposits in the Whitewood Creek valley enter the creek at various seeps along its downstream course to the Belle Fourche river, and the Belle Fourche River itself, which empties into the Cheyenne River and eventually into Lake Oahe.

Diet of juvenile burbot and insight on gape limitation

USGS Publications Warehouse

Klein, Zachary B.; Hardy, Ryan S.; Quist, Michael C.

2016-01-01

Throughout much of their distribution, Burbot (Lota lota ) populations are declining or have been extirpated. Burbot in the Kootenai River, Idaho represent one such imperiled population. In an effort to restore Burbot in the Kootenai River, managers have turned to conservation aquaculture. However, no appreciable increase in natural recruitment has been observed in the system. The lack of natural recruitment is believed to be partly due to a deficiency of high-quality prey. As a result, we sought to i) describe the diet of juvenile Burbot, ii) evaluate the influence of Burbot mouth gape on diet and iii) estimate prey availability at release locations. Burbot were stocked into two earthen ponds at the Boundary Creek Wildlife Management Area (BCWMA) and sampled weekly to evaluate diet. Zooplankton were sampled weekly from each pond and from release locations of hatchery-reared Burbot (i.e., Kootenai River, Goat River, Boundary Creek, Deep Creek) to quantify prey availability. Over the course of the study (~3 months), Burbot primarily fed on Cyclopoida. Burbot never appeared to be gape limited and exhibited little variability in the size of zooplankton ingested. Zooplankton densities at stocking locations were relatively low in comparison to BCWMA ponds. Low zooplankton densities at release sites indicate that alternative management actions may need to be considered to enhance Burbot recruitment in the Kootenai River drainage.

Crustal Structure of the Yakutat Microplate: Constraints from STEEP Wide-angle Seismic Data

NASA Astrophysics Data System (ADS)

Christeson, G. L.; van Avendonk, H.; Gulick, S. P.; Worthington, L.; Pavlis, T.

2008-12-01

In Fall 2008 we will conduct a seismic program focusing on the Yakutat microplate. As part of this study we plan to acquire two wide-angle profiles: an onshore-offshore northwest-southeast oriented profile extending from the Bering glacier onto the continental shelf and across the Dangerous River Zone, and an offshore northeast-southwest oriented profile extending from the ocean basin across the Transition fault and into Yakutat Bay. The sound source will be the R/V Langseth's tuned 6600 cu. in., 36 air gun array. Ocean bottom seismometers will be positioned at ~15 km spacing, and Texan seismometers at 1-4 km spacing across the Bering Glacier. Coincident deep-penetrating seismic reflection data will be acquired on the marine portion of both profiles using a 8-km, 640-channel solid hydrophone streamer. Existing models for the Yakutat microplate disagree as to whether it is a continental fragment attached to normal oceanic crust or an oceanic plateau, and if the deep structure changes from west to east across the Dangerous River Zone. In the continental fragment model uplift is concentrated along crustal-scale thrust faulting at the ocean crust boundary (Dangerous River Zone?) resulting in focused and rapid erosion. In the oceanic plateau model more distributed, regional uplift is expected which will produce widespread exhumation with net erosion potentially coupled with glacial cycles. Thus distinguishing between these models, which we expect to accomplish with our planned seismic program, is vital for linking tectonics to erosion on both spatial and temporal scales.

Turbidites as proxy for past flood events: Testing this approach in a large clastic system (Lake Geneva, France/Switzerland)

NASA Astrophysics Data System (ADS)

Kremer, Katrina; Girardclos, Stéphanie

2017-04-01

Turbidites recorded in lake sediments are often used to reconstruct the frequency of past flood and also seismological events. However, for such a reconstruction, the origin and causes of the recorded turbidites need to be clearly identified. In this study, we test if turbidites can be used as paleohydrological archive based on the the sedimentary record of Lake Geneva resulting from inputs by the Rhone and Dranse clastic river systems. Our approach is based on several methods combining high-resolution seismic reflection data with geophysical (magnetic susceptibility, grain size) and high-resolution XRF/XRD data measured on ca. 10-m-long sediment cores (dated by radiocarbon ages and 137Cs activity). This dataset allows distinguishing between the different sources (rivers or hemipelagic sediment) of the turbidites deposited in the deep basin of Lake Geneva. However, no clear distinction between the various trigger processes (mass failures or floods) could be made, thus flood deposits could not be clearly identified. From our results, we also conclude that the lack of turbidite deposits in the deep basin between the 15th and 18th century seems to be linked to a change in turbidite depocentre due to the Rhone River mouth shifting possibly triggered by human activity and not by any direct climate effect. This study demonstrates that a least two conditions are needed to perform an adequate paleohydrological interpretation based on turbidite records: (1) the holistic understanding of the basin sedimentary system and (2) the distinction of flood-induced turbidites from other types of turbidites (mass failures etc.).

Are big basins just the sum of small catchments?

USGS Publications Warehouse

Shaman, J.; Stieglitz, M.; Burns, D.

2004-01-01

Many challenges remain in extending our understanding of how hydrologic processes within small catchments scale to larger river basins. In this study we examine how low-flow runoff varies as a function of basin scale at 11 catchments, many of which are nested, in the 176 km2 Neversink River watershed in the Catskill Mountains of New York. Topography, vegetation, soil and bedrock structure are similar across this river basin, and previous research has demonstrated the importance of deep groundwater springs for maintaining low-flow stream discharge at small scales in the basin. Therefore, we hypothesized that deep groundwater would contribute an increasing amount to low-flow discharge as basin scale increased, resulting in increased runoff. Instead, we find that, above a critical basin size of 8 to 21 km2, low-flow runoff is similar within the Neversink watershed. These findings are broadly consistent with those of a previous study that examined stream chemistry as a function of basin scale for this watershed. However, we find physical evidence of self-similarity among basins greater than 8 km2, whereas the previous study found gradual changes in stream chemistry among basins greater than 3 km 2. We believe that a better understanding of self-similarity and the subsurface flow processes that affect stream runoff will be attained through simultaneous consideration of both chemical and physical evidence. We also suggest that similar analyses of stream runoff in other basins that represent a range of spatial scales, geomorphologies and climate conditions will further elucidate the issue of scaling of hydrologic processes. Copyright ?? 2004 John Wiley & Sons, Ltd.

Estimating nitrate emissions to surface water at regional and national scale: comparison of models using detailed regional and national-wide databases (France)

NASA Astrophysics Data System (ADS)

Dupas, R.; Gascuel-Odoux, C.; Durand, P.; Parnaudeau, V.

2012-04-01

The European Union (EU) Water Framework Directive (WFD) requires River Basin District managers to carry out an analysis of nutrient pressures and impacts, in order to evaluate the risk of water bodies failing to reach "good ecological status" and to identify those catchments where prioritized nonpoint-source control measures should be implemented. A model has been developed to estimate nitrate nonpoint-source emissions to surface water, using readily available data in France. It was inspired from US model SPARROW (Smith al., 1997) and European model GREEN (Grizzetti et al., 2008), i.e. statistical approaches consisting of linking nitrogen sources and catchments' land and rivers characteristics. The N-nitrate load (L) at the outlet of a catchment is expressed as: L= R*(B*Lsgw+Ldgw+PS)-denitlake Where denitlake is a denitrification factor for lakes and reservoirs, Lsgw is the shallow groundwater discharge to streams (derived from the base flow index and N surplus in kgN.ha-1.yr-1), Ldgw is the deep groundwater discharge to streams (derived from total runoff, the base flow index and deep groundwater N concentration), PS is point sources from domestic and industrial origin (kgN.ha-1.yr-1) and R and B are the river system and basin reduction factor, respectively. Besides calibrating and evaluating the model at a national scale, its predictive quality was compared with those of regionalized models in Brittany (Western France) and in the Seine river basin (Paris basin), where detailed regional databases are available. The national-scale model proved to provide robust predictions in most conditions encountered in France, as it fitted observed N-nitrate load with an efficiency of 0.69. Regionalization of the model reduced the standard error in the prediction of N-nitrate loads by about 19 Hence, the development of regionalized models should be advocated only after the trade-off between improvement of fit and degradation of parameters' estimation has come under scrutiny.

Subsurface geology and porosity distribution, Madison Limestone and underlying formations, Powder River basin, northeastern Wyoming and southeastern Montana and adjacent areas

USGS Publications Warehouse

Peterson, James A.

1978-01-01

To evaluate the Madison Limestone and associated rocks as potential sources for water supplies in the Powder River Basin and adjacent areas, an understanding of the geologic framework of these units, their lithologic facies patterns, the distribution of porosity zones, and the relation between porosity development and stratigraphic facies is necessary. Regionally the Madison is mainly a fossiliferous limestone. However, in broad areas of the eastern Rocky Mountains and western Great Plains, dolomite is a dominant constituent and in places the Madison is almost entirely dolomite. Within these areas maximum porosity development is found and it seems to be related to the coarser crystalline dolomite facies. The porosity development is associated with tabular and fairly continuous crystalline dolomite beds separated by non-porous limestones. The maximum porosity development in the Bighorn Dolomite, as in the Madison, is directly associated with the occurrence of a more coarsely crystalline sucrosic dolomite facies. Well data indicate, however, that where the Bighorn is present in the deeper parts of the Powder River Basin, it may be dominated by a finer crystalline dolomite facies of low porosity. The 'Winnipeg Sandstone' is a clean, generally well-sorted, medium-grained sandstone. It shows good porosity development in parts of the northern Powder River Basin and northwestern South Dakota. Because the sandstone is silica-cemented and quartzitic in areas of deep burial, good porosity is expected only where it is no deeper than a few thousand feet. The Flathead Sandstone is a predominantly quartzose, slightly feldspathic sandstone, commonly cemented with iron oxide. Like the 'Winnipeg Sandstone,' it too is silica-cemented and quartzitic in many places so that its porosity is poor in areas of deep burial. Illustrations in this report show the thickness, percent dolomite, and porosity-feet for the Bighorn Dolomite and the Madison Limestone and its subdivisions. The porosity-feet for the 'Winnipeg' and Flathead Sandstones and four regional geologic sections are also shown.

Variations in fluvial style in the Westwater Canyon Member, Morrison formation (Jurassic), San Juan basin, Colorado plateau

USGS Publications Warehouse

Miall, A.D.; Turner-Peterson, C. E.

1989-01-01

Techniques of architectural element analysis and lateral profiling have been applied to the fluvial Westwater Canyon Member of the Morrison Formation (Jurassic) in southern San Juan Basin. On a large scale, the sandstone-body architecture consists mainly of a series of tabular sandstone sheets 5-15 m thick and hundreds of meters wide, separated by thin fine-grained units. Internally these sheets contain lateral accretion surfaces and are cut by channels 10-20 m deep and at least 250 m wide. On a more detailed scale, interpretations made from large-scale photomosaics show a complex of architectural elements and bounding surfaces. Typical indicators of moderate- to high-sinuosity channels (lateral accretion deposits) coexist in the same outcrop with downstream-accreted macroform deposits that are typical of sand flats of low-sinuosity, multiple-channel rivers. Broad, deep channels with gently to steeply dipping margins were mapped in several of the outcrops by carefully tracing major bounding surfaces. Locally thick accumulations of plane-laminated and low-angle cross-laminated sandstone lithofacies suggest rapid flow, probably transitional to upper flow regime conditions. Such a depositional style is most typical of ephemeral rivers or those periodically undergoing major seasonal (or more erratic) stage fluctuations, an interpretation consistent with independent mineralogical evidence of aridity. Fining-upward sequences are rare in the project area, contrary to the descriptions of Campbell (1976). The humid alluvial fan model of Galloway (1978) cannot be substantiated and, similarly, the architectural model of Campbell (1976) requires major revision. Comparisons with the depositional architecture of the large Indian rivers, such as the Ganges and Brahmaputra, still seem reasonable, as originally proposed by Campbell (1976), although there is now convincing evidence for aridity and for major stage fluctuations, which differs both from those modern rivers and Campbell's interpretation. ?? 1989.

Hydrogeology and physical characteristics of water samples at the Red River aluminum site, Stamps, Arkansas, April 2001

USGS Publications Warehouse

Czarnecki, John B.; Stanton, Gregory P.; Freiwald, David A.

2001-01-01

The Red River Aluminum site near Stamps, Arkansas, contains waste piles of salt cake and metal byproducts from the smelting of aluminum. The waste piles are subjected to about 50 inches of rainfall a year, resulting in the dissolution of the salts and metal. To assess the potential threat to underlying ground-water resources at the site, its hydrogeology was characterized by measuring water levels and field parameters of water quality in 23 wells and at 2 surface-water sites. Seventeen of these monitor wells were constructed at various depths for this study to allow for the separate characterization of the shallow and deep ground-water systems, the calculation of vertical gradients, and the collection of water samples at different depths within the flow system. Lithologic descriptions from drill-hole cuttings and geophysical logs indicate the presence of interbedded sands, gravels, silts, and clays to depths of 65 feet. The regionally important Sparta aquifer underlies the site. Water levels in shallow wells indicate radial flow away from the salt-cake pile located near the center of the site. Flow in the deep system is to the west and southwest toward Bodcau Creek. Water-level data from eight piezometer nests indicate a downward hydraulic gradient from the shallow to deep systems across the site. Values of specific conductance (an indicator of dissolved salts) ranged from 215 to 196,200 microsiemens per centimeter and indicate that saline waters are being transported horizontally and vertically downward away from the site

Deep-water lithofacies and conodont faunas of the Lisburne Group, western Brooks Range, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1992

USGS Publications Warehouse

Dumoulin, Julie A.; Harris, Anita G.; Schmidt, Jeanine M.

1993-01-01

Deep-water lithofacies of the Lisburne Group occur in thrust sheets in the western part of the foreland fold and thrust belt of the Brooks Range and represent at least three discrete units. The Kuna Formation (Brooks Range allochthon) consists mostly of spiculitic mudstone and lesser shale; subordinate carbonate layers are chiefly diagenetic dolomite. Predominantly shale sections of the Kuna that contain few sponge spicules occur in the western part of the study area. The Akmalik Chert (Picnic Creek allochthon) is mostly radiolarian-spiculitic chert; rare limy beds are calcitized radiolarite. The Rim Butte unit (Ipnavik River allochthon) consists chiefly of calcareous turbidites, derived from both shallow- and deep-water sources, interbedded with spiculitic mudstone. Much of the material in the turbidites came from a contemporaneous carbonate platform and margin, but some fossils and lithic clasts were eroded from older, already lithified carbonate-platform rocks. All three units appear to be roughly coeval and are chiefly Osagean (late Early Mississippian) in age in the study area.Shallow-water lithofacies of the Lisburne Group exposed in the Howard Pass area (Brooks Range allochthon) are mostly of Meramecian (early Late Mississippian) age. Thus, these carbonate-platform rocks were not the source of the calcareous turbidites in the Rim Butte unit. Rim Butte turbidites could have been derived from older platform carbonate rocks such as those of the Utukok Formation (Kelly River allochthon) exposed mainly to the west of the Howard Pass quadrangle.

The Influence of Topography on Subaqueous Sediment Gravity Flows and the Resultant Deposits: Examples from Deep-water Systems in Offshore Morocco and Offshore Trinidad

NASA Astrophysics Data System (ADS)

Deng, H.; Wood, L.; Overeem, I.; Hutton, E.

2016-12-01

Submarine topography has a fundamental control on the movement of sediment gravity flows as well as the distribution, morphology, and internal heterogeneity of resultant overlying, healing-phase, deep-water reservoirs. Some of the most complex deep-water topography is generated through both destructive and constructive mass transport processes. A series of numerical models using Sedflux software have been constructed over high resolution mass transport complexes (MTCs) top paleobathymetric surfaces mapped from 3D seismic data in offshore Morocco and offshore eastern Trinidad. Morocco's margin is characterized by large, extant rafted blocks and a flow perpendicular fabric. Trinidad's margin is characterized by muddier, plastic flows and isolated extrusive diapiric buttresses. In addition, Morocco's margin is a dry, northern latitude margin that lacks major river inputs, while Trinidad's margin is an equatorial, wet climate that is fed by the Orinoco River and delta. These models quantitatively delineate the interaction of healing-phase gravity flows on the tops of two very different topographies and provide insights into healing-phase reservoir distribution and stratigraphic trap development. Slopes roughness, curvatures, and surface shapes are measured and quantified relative to input points to quantify depositional surface character. A variety of sediment gravity flow types have been input and the resultant interval assessed for thickness and distribution relative to key topography parameters. Mathematical relationships are to be analyzed and compared with seismic data interpretation of healing-phase interval character, toward an improved model of gravity sedimentation and topography interactions.

Gulf of Mexico Monitoring Via The Remotely Controlled CMR SailBuoy

NASA Astrophysics Data System (ADS)

Wienders, N.; Hole, L. R.; Peddie, D.

2013-12-01

The CMR SailBuoy is an unmanned ocean vessel capable of traveling the oceans for extended periods of time. It navigates the oceans autonomously - transmitting data at regular intervals using the Iridium network for two way communication. The SailBuoy can be used for a wide variety of ocean applications from measuring ocean and atmospheric parameters to tracking oil spills or acting as a communication relay station for subsea instrumentation. As part of the Deep-C project(Deep Sea to Coast Connectivity in the Eastern Gulf of Mexico), a two month campaign was carried out from March to May 2013 with the purpose of collecting sea surface data (temperature, salinity and oxygen) during the spring bloom. The campaign was unique in that the SailBouy was remotely controlled from Norway after being deployed from the RV Apalachee. The SailBuoy was deployed approximately 11 nautical miles (nm) south of Cape San Blas. During its mission she sailed approximately 840nm on a cruise track across the Gulf coast, from the Florida Panhandle to Louisiana. The SailBuoy project is part of Deep-C's physical oceanography research which seeks to, among other things, understand how particles and dissolved substances (such as oil) travel from the deep sea to the Louisiana, Mississippi, Alabama and Florida shorelines. This involves cross-shelf transport and upwelling mechanisms, which the SailBuoy is capable of measuring. An other focus was the sampling of the Mississippi river plume, which has been shown to influence the distribution of particles, oil, dissolved substances in the water, at least at the surface level. Sea surface salinity measurement via satellite do not provide, at the moment, sufficient resolution and accuracy and instead, the SailBuoy seems to be a very convenient instrument to track river plumes. In this presentation we describe the collected data and include comparisons with high resolution ocean model outputs. We also present further plans for SailBuoy campaigns.

Regional ground-water discharge to large streams in the upper coastal plain of South Carolina and parts of North Carolina and Georgia

USGS Publications Warehouse

Aucott, W.R.; Meadows, R.S.; Patterson, G.G.

1987-01-01

Base flow was computed to estimate discharge from regional aquifers for six large streams in the upper Coastal Plain of South Carolina and parts of North Carolina and Georgia. Aquifers that sustain the base flow of both large and small streams are stratified into shallow and deep flow systems. Base-flow during dry conditions on main stems of large streams was assumed to be the discharge from the deep groundwater flow system. Six streams were analyzed: the Savannah, South and North Fork Edisto, Lynches, Pee Dee, and the Luber Rivers. Stream reaches in the Upper Coastal Plain were studied because of the relatively large aquifer discharge in these areas in comparison to the lower Coastal Plain. Estimates of discharge from the deep groundwater flow system to the six large streams averaged 1.8 cu ft/sec/mi of stream and 0.11 cu ft/sec/sq mi of surface drainage area. The estimates were made by subtracting all tributary inflows from the discharge gain between two gaging stations on a large stream during an extreme low-flow period. These estimates pertain only to flow in the deep groundwater flow system. Shallow flow systems and total base flow are > flow in the deep system. (USGS)

National Program for Inspection of Non-Federal Dams. Berry Brook Dam, (NH 00313), State Number 83.06, Piscataqua River Basin, Farmington, New Hampshire. Phase I Inspection Report.

DTIC Science & Technology

1979-12-01

at embedded steel items 7 Spalling Minor spalling of surface ’+ deep exposi gcoarse aggregate of weir and dcwnstream f ce. Any Visible Reinforcing...1937, the above dam was inspected by me on _L LEO acomprie _ NOTES ON PHYSICAL CONDITI IT Ab ut mcnt s

Crossing the Water: Spiritual Growth in "Bridge to Terabithia" and "Lizzie Bright and the Buckminster Boy"

ERIC Educational Resources Information Center

Thomas, Trudelle

2011-01-01

The author analyses two award-winning juvenile novels, "Bridge to Terabithia" by Katherine Paterson and "Lizzie Bright and the Buckminster Boy" by Gary Schmidt. Each novel portrays a deep friendship between a boy and girl who cross a stream (or river) into a world that includes fantasy, play, closeness to nature and animals, and a sense of the…

75 FR 66080 - White River Hydro, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-27

... structure; (9) a 12-foot-diameter, 2,842- foot-long concrete tunnel; (10) a 73-foot-deep forebay; (11) three... do not need to refile. See 18 CFR 385.2001(a)(1)(iii) and the instructions on the Commission's Web...Library'' link of Commission's Web site at http://www.ferc.gov/docs-filing/elibrary.asp . Enter the docket...

75 FR 3217 - J&T Hydro Company; H. Dean Brooks and W. Bruce Cox; Notice of Application for Transfer of License...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-20

... Ramseur Project No. 11392 located on the Deep River in Randolph County, North Carolina. The transferor and...)(iii)(2009) and the instructions on the Commission's Web site under the ``e-Filing'' link. If unable to... the Commission's Web site located at http://www.ferc.gov/filing-comments.asp . More information about...

An Update of Hydrologic Conditions and Distribution of Selected Constituents in Water, Snake River Plain Aquifer and Perched-Water Zones, Idaho National Laboratory, Idaho, Emphasis 2002-05

USGS Publications Warehouse

Davis, Linda C.

2008-01-01

Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds, evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the Snake River Plain aquifer and perched-water zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched-water zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched-water wells in the USGS ground-water monitoring networks during 2002-05. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged primarily from infiltration of irrigation water, infiltration of streamflow, ground-water inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2001 to March-May 2005, water levels in wells declined throughout the INL area. The declines ranged from about 3 to 8 feet in the southwestern part of the INL, about 10 to 15 feet in the west central part of the INL, and about 6 to 11 feet in the northern part of the INL. Water levels in perched water wells declined also, with the water level dropping below the bottom of the pump in many wells during 2002-05. For radionuclides, concentrations that equal 3s, wheres s is the sample standard deviation, represent a measurement at the minimum detectable concentration, or 'reporting level'. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2002-05. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In October 2005, reportable concentrations of tritium in ground water ranged from 0.51+or-0.12 to 11.5+or-0.6 picocuries per milliliter and the tritium plume extended south-southwestward in the general direction of ground-water flow. Tritium concentrations in water from several wells southwest of the Idaho Nuclear Technology and Engineering Center (INTEC) decreased or remained constant as they had during 1998-2001, with the exception of well USGS 47, which increased a few picocuries per milliliter. Most wells completed in shallow perched water at the Reactor Technology Complex (RTC) were dry during 2002---05. Tritium concentrations in deep perched water exceeded the reporting level in nine wells at the RTC. The tritium concentration in water from one deep perched water well exceeded the reporting level at the INTEC. Concentrations of strontium-90 in water from 14 of 34 wells sampled during October 2005 exceeded the reporting level. Concentrations ranged from 2.2+or-0.7 to 33.1+or-1.2 picocuries per liter. However, concentrations from most wells remained relatively constant or decreased since 1989. Strontium-90 has not been detected within the eastern Snake River Plain aquifer beneath the RTC partly because of the exclusive use of waste-disposal ponds and lined evaporation ponds rather than the disposal well for radioactive-wastewater disposal at RTC. At the RTC, strontium-90 concentrations in water from six wells completed in deep perched ground water exceeded the reporting level during 2002-05. At the INTEC, the reporting level was exceeded in water from three wells completed in deep perched ground water. During 2002-05, concentrations of plutonium-238, and plutonium-239, -240 (undivided), and americium-241 were less than the reporting level in water samples from all wells sampled at the INL. During 2002-05, concentrations of cesium-137 in water from all wells sa

Seasonal Variation of Phytoplankton and Primary Production in the Thames River, Southeastern Connecticut

NASA Astrophysics Data System (ADS)

Wainright, S. C.

2016-02-01

A year-long study was performed to investigate seasonal changes in the phytoplankton biomass and primary production in the Thames River, a salt wedge estuary that empties into Long Island Sound in southeastern CT. Chlorophyll measurements were made on discrete filtered samples collected above and below the 1-3 m deep pycnocline at a 5-meter deep station. Surface chlorophyll concentrations, primarily from diatoms, averaged approx. 2 mg m-3, with maxima (up to 10 mg m-3) during summer months (Jun to Aug) and minima during October through March (as low as 0.3 mg m-3). The lower water layer had nearly the same annual average but a smaller range (0.7-3.3 mg m-3) and a winter/spring bloom (Jan-Apr) that was not seen in surface water. During most of the winter, chlorophyll concentrations were higher in the lower layer. Primary production, as measured by 13C uptake in bottle incubations, averaged 67 mgC m-3 h-1 in surface water [range 0.1 (Jan 2012) to 800 mgC m-3 h-1 (Aug 2011)], and 3 mgC m-3 h-1 [range 0.04 (Jan 2012) to 17 mgC m-3 h-1 (Aug 2011)] in the lower layer. On most occasions, deep water incubated near the surface had a higher primary production rate than surface water incubated at the surface; apparently the light-limited phytoplankton in the lower layer were released from light-limitation during these incubations. During the study period there were over a dozen heavy wind or heavy rain events, including Hurricane Irene in August and a freak Nor'easter snow storm in October 2011. Hurricane Irene was associated with a large decline in phytoplankton biomass and primary production. With significant storms as frequent as the rate of sampling, it is difficult to separate a "storm effect" from a background seasonal pattern. The study reveals that phytoplankton, especially those in the lower layer, are light-limited in the Thames River estuary, and that the effects of significant storm events are superimposed on significant seasonal variation.

Fall Chinook Salmon Spawning Ground Surveys in the Snake River Basin Upriver of Lower Granite Dam, 2005 Annual Report.

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

Garcia, A.P.; Bradbury, S.; Arnsberg, B.D.

2006-10-01

Redd counts are routinely used to document the spawning distribution of fall Chinook salmon (Oncorhynchus tshawytscha) in the Snake River basin upriver of Lower Granite Dam. The first reported redd counts were from aerial searches conducted intermittently between 1959 and 1978 (Irving and Bjornn 1981, Witty 1988; Groves and Chandler 1996)(Appendix 1). In 1986, the Washington Department of Fish and Wildlife began an annual monitoring program that, in addition to the Snake River, included aerial searches of the Grande Ronde River the first year (Seidel and Bugert 1987), and the Imnaha River in subsequent years (Seidel et al. 1988; Bugertmore » et al. 1989-1991; Mendel et al. 1992). The U. S. Fish and Wildlife Service and Idaho Power Company began contributing to this effort in 1991 by increasing the number of aerial searches conducted each year and adding underwater searches in areas of the Snake River that were too deep to be searched from the air (Connor et al. 1993; Garcia et al. 1994a, 1994b, 1996-2005; Groves 1993; Groves and Chandler 1996). The Nez Perce Tribe added aerial searches in the Clearwater River basin beginning in 1988 (Arnsberg et. al 1992), and the Salmon River beginning in 1992. Currently searches are conducted cooperatively by the Nez Perce Tribe, Idaho Power Company, and U.S. Fish and Wildlife Service. Our objective for this report was to consolidate the findings from annual redd searches into a single document, containing detailed information about the searches from the most recent spawning season, and summary information from previous years. The work conducted in 2005 was funded by the Bonneville Power Administration and Idaho Power Company.« less

Fall Chinook Salmon Spawning Ground Surveys in the Snake River Basin Upriver of Lower Granite Dam, Annual Report 2002.

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

Garcia, Aaron P.; Bradbury, S.M.; Arnsberg, Billy D.

2003-09-01

Redd counts were used to document the spawning distribution of fall chinook salmon (Oncorhynchus tshawytscha) in the Snake River basin upriver of Lower Granite Dam. The first reported redd counts were from aerial searches conducted intermittently between 1959 and 1978 (Irving and Bjornn 1981, Witty 1988; Groves and Chandler 1996)(Appendix 1). In 1986, the Washington Department of Fish and Wildlife began an annual monitoring program that, in addition to the Snake River, included aerial searches of the Grande Ronde River the first year (Seidel and Bugert 1987), and the Imnaha River in subsequent years (Seidel et al. 1988; Bugert etmore » al. 1989-1991; Mendel et al. 1992). The U. S. Fish and Wildlife Service and Idaho Power Company began contributing to this effort in 1991 by increasing the number of aerial searches conducted each year and adding underwater searches in areas of the Snake River that were too deep to be searched from the air (Connor et al. 1993; Garcia et al. 1994a, 1994b, 1996-2001; Groves 1993; Groves and Chandler 1996). The Nez Perce Tribe added aerial searches in the Clearwater River basin beginning in 1988 (Arnsberg et. al 1992) and the Salmon River beginning in 1992. Currently searches are conducted cooperatively by the Nez Perce Tribe, Idaho Power Company, and U. S. Fish and Wildlife Service. Our objective for this report was to consolidate the findings from annual redd searches into a single document containing detailed information about the searches from the most recent spawning season, and summary information from previous years. The work conducted in 2002 was funded by the Bonneville Power Administration (Projects 1998-01-003 and 1994-03-400) and the Idaho Power Company.« less

Fall Chinook Salmon Spawning Ground Surveys in the Snake River Basin Upriver of Lower Granite Dam, 2007 Annual Report.

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

Garcia, A.P.; Bradbury, S.; Arnsberg, B.D.

2008-11-25

Redd counts are routinely used to document the spawning distribution of fall Chinook salmon (Oncorhynchus tshawytscha) in the Snake River basin upriver of Lower Granite Dam. The first reported redd counts were from aerial searches conducted intermittently between 1959 and 1978 (Irving and Bjornn 1981, Witty 1988; Groves and Chandler 1996)(Appendix 1). In 1986, the Washington Department of Fish and Wildlife began an annual monitoring program that, in addition to the Snake River, included aerial searches of the Grande Ronde River the first year (Seidel and Bugert 1987), and the Imnaha River in subsequent years (Seidel et al. 1988; Bugertmore » et al. 1989-1991; Mendel et al. 1992). The U. S. Fish and Wildlife Service and Idaho Power Company began contributing to this effort in 1991 by increasing the number of aerial searches conducted each year and adding underwater searches in areas of the Snake River that were too deep to be searched from the air (Connor et al. 1993; Garcia et al. 1994a, 1994b, 1996-2007; Groves 1993; Groves and Chandler 1996). The Nez Perce Tribe added aerial searches in the Clearwater River basin beginning in 1988 (Arnsberg et. al 1992), and the Salmon River beginning in 1992. Currently searches are conducted cooperatively by the Nez Perce Tribe, Idaho Power Company, and U. S. Fish and Wildlife Service. Our objective for this report was to consolidate the findings from annual redd searches counted upstream of Lower Granite Dam into a single document, containing detailed information about the searches from the most recent spawning season, and summary information from previous years. The work conducted in 2007 was funded by the Bonneville Power Administration and Idaho Power Company.« less

Fall Chinook Salmon Spawning Ground Surveys in the Snake River Basin Upriver of Lower Granite Dam, Annual Report 2003.

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

Garcia, A.P.; Bradbury, S.M.; Arnsberg, B.D.

2004-08-01

Redd counts were used to document the spawning distribution of fall chinook salmon (Oncorhynchus tshawytscha) in the Snake River basin upriver of Lower Granite Dam. The first reported redd counts were from aerial searches conducted intermittently between 1959 and 1978 (Irving and Bjornn 1981, Witty 1988; Groves and Chandler 1996)(Appendix 1). In 1986, the Washington Department of Fish and Wildlife began an annual monitoring program that, in addition to the Snake River, included aerial searches of the Grande Ronde River the first year (Seidel and Bugert 1987), and the Imnaha River in subsequent years (Seidel et al. 1988; Bugert etmore » al. 1989-1991; Mendel et al. 1992). The U. S. Fish and Wildlife Service and Idaho Power Company began contributing to this effort in 1991 by increasing the number of aerial searches conducted each year and adding underwater searches in areas of the Snake River that were too deep to be searched from the air (Connor et al. 1993; Garcia et al. 1994a, 1994b, 1996-2003; Groves 1993; Groves and Chandler 1996). The Nez Perce Tribe added aerial searches in the Clearwater River basin beginning in 1988 (Arnsberg et. al 1992) and the Salmon River beginning in 1992. Currently searches are conducted cooperatively by the Nez Perce Tribe, Idaho Power Company, and U. S. Fish and Wildlife Service. Our objective for this report was to consolidate the findings from annual redd searches into a single document containing detailed information about the searches from the most recent spawning season, and summary information from previous years. The work conducted in 2003 was funded by the Bonneville Power Administration (Projects 199801003, 199801004, 199403400, 198335003), Idaho Power Company, and Bureau of Land Management.« less

Fall Chinook Salmon Spawning Ground Surveys in the Snake River Basin Upriver of Lower Granite Dam, 2004 Annual Report.

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

Garcia, A.P.; Bradbury, S.; Arnsberg, B.D.

2005-10-01

Redd counts were used to document the spawning distribution of fall Chinook salmon (Oncorhynchus tshawytscha) in the Snake River basin upriver of Lower Granite Dam. The first reported redd counts were from aerial searches conducted intermittently between 1959 and 1978 (Irving and Bjornn 1981, Witty 1988; Groves and Chandler 1996)(Appendix 1). In 1986, the Washington Department of Fish and Wildlife began an annual monitoring program that, in addition to the Snake River, included aerial searches of the Grande Ronde River the first year (Seidel and Bugert 1987), and the Imnaha River in subsequent years (Seidel et al. 1988; Bugert etmore » al. 1989-1991; Mendel et al. 1992). The U.S. Fish and Wildlife Service and Idaho Power Company began contributing to this effort in 1991 by increasing the number of aerial searches conducted each year and adding underwater searches in areas of the Snake River that were too deep to be searched from the air (Connor et al. 1993; Garcia et al. 1994a, 1994b, 1996-2004; Groves 1993; Groves and Chandler 1996). The Nez Perce Tribe added aerial searches in the Clearwater River basin beginning in 1988 (Arnsberg et. al 1992), and the Salmon River beginning in 1992. Currently searches are conducted cooperatively by the Nez Perce Tribe, Idaho Power Company, and U. S. Fish and Wildlife Service. Our objective for this report was to consolidate the findings from annual redd searches into a single document, containing detailed information about the searches from the most recent spawning season, and summary information from previous years. The work conducted in 2004 was funded by the Bonneville Power Administration, Idaho Power Company, and Bureau of Land Management.« less

Earth Observations taken by the Expedition 17 Crew

NASA Image and Video Library

2008-10-16

ISS017-E-019616 (16 Oct. 2008) --- A dust storm in Turkmenistan, Central Asia is featured in this image photographed by an Expedition 17 crewmember on the International Space Station. This west-looking view, taken with a short focal length lens from the station, shows a wide swath of central Asia--from Afghanistan, along the length of Turkmenistan to the Caspian Sea. Winds blowing down the largest river valley in the region, the Amudarya, were strong enough to raise a large dust storm. Dust appears as a light brown mass extending into the center of the image from the lower right. Diffuse dust from prior windy weather appears over much of the area making a regional haze that clouds much of the landscape detail. The haze partly obscures the irrigated agriculture in Turkmenistan and entirely obscures the Caspian Sea. Numerous rivers rise in the Hindu Kush mountain complex (lower left). The Band-i Amir River is a major tributary of the main regional river, the Amudarya, which it reaches via a deep canyon. The Amudarya River was the major historical contributor of water to the Aral Sea, but today extensive diversion of river water for agricultural purposes has lead to extensive exposure and desiccation of the sea bed. The exposed sea bed is a major source of saline dusts contaminated with agricultural chemicals that pose a significant environmental hazard to central Asia. To a lesser extent, dusts are also mobilized from sediments along the Amudarya river channel. The Paropamisus Range and the Amudarya (also known as the Oxus River) are mentioned in histories of Alexander the Great's famous military expedition from Greece to India. His horsemen made a fast side excursion from near the Caspian Sea (top right) as far as the Amudarya (lower right).

Summer habitat use by Columbia River redband trout in the Kootenai River drainage, Montana

USGS Publications Warehouse

Muhlfeld, Clint C.; Bennett, David H.

2001-01-01

The reported decline in the abundance, distribution, and genetic diversity of Columbia River redband trout Oncorhynchus mykiss gairdneri (a rainbow trout subspecies) has prompted fisheries managers to investigate their habitat requirements, identify critical habitat, and develop effective conservation and recovery programs. We analyzed the microhabitat, mesohabitat, and macrohabitat use and distribution of Columbia River redband trout by means of snorkel surveys in two watersheds in the Kootenai River drainage, Montana and Idaho, during the summers of 1997 and 1998. Juvenile (36–125 mm total length, TL) and adult (>=126 mm TL) fish preferred deep microhabitats (>=0.4 m) with low to moderate velocities (<=0.5 m/s) adjacent to the thalweg. Conversely, age-0 (<=35 mm) fish selected slow water (<=0.1 m/s) and shallow depths (<=0.2 m) located in lateral areas of the channel. Age-0, juvenile, and adult fish strongly selected pool mesohabitats and avoided riffles; juveniles and adults generally used runs in proportion to their availability. At the macrohabitat scale, density of Columbia River redband trout (35 mm) was positively related to the abundance of pools and negatively related to stream gradient. The pool: riffle ratio, gradient, and stream size combined accounted for 80% of the variation in density among 23 stream reaches in five streams. Our results demonstrate that low-gradient, medium-elevation reaches with an abundance of complex pools are critical areas for the production of Columbia River redband trout. These data will be useful in assessing the impacts of land-use practices on the remaining populations and may assist with habitat restoration or enhancement efforts.

Transport and fluxes of terrestrial polycyclic aromatic hydrocarbons in a small mountain river and submarine canyon system.

PubMed

Lin, Bing-Sian; Lee, Chon-Lin; Brimblecombe, Peter; Liu, James T

2016-08-01

Polycyclic aromatic hydrocarbon (PAH) concentrations in the Gaoping River were investigated in the wet and dry seasons. PAH characteristics allowed us to trace the particulate matter transported in a river-sea system containing a small mountain river, continental shelf, and submarine canyon. PAH signatures of the Gaoping River showed that particles were rapidly transported from the high mountain to the Gaoping coastal areas in the wet season, even arriving at the deep ocean via the Gaoping Submarine Canyon. By contrast, in the dry season, the particles were delivered quite slowly and included mostly pyrogenic contaminants. The annual riverine flux estimates for PAHs were 2241 kg in the Gaoping river-sea system. Only 18.0 kg were associated with the dissolved phase; the rest was bound onto particles. The fluxes caused by typhoons and their effects accounted for 20.2% of the dissolved and 68.4% of the particulate PAH fluxes from the river. Normalized partition coefficients for organic carbon suggested that PAHs were rigid on the particles. Distinct source characteristics were evident for PAHs on riverine suspended particles and coastal surface sediments: the particles in the wet season (as background signals) were similar to petrogenic sources, whereas the particles in the dry season had characteristics of coal burning and vehicular emissions. The sediments in the northwestern shelf were similar to pyrogenic sources (including vehicular emissions and coal and biomass burning), whereas the sediments in the canyon and southeastern shelf arose from mixed sources, although some diesel signature was also evident. Copyright © 2016 Elsevier Ltd. All rights reserved.

Andes Altiplano, South America

NASA Image and Video Library

1991-08-11

STS043-151-159 (2-11 August 1991) --- This photograph looks westward over the high plateau of the southern Peruvian Andes west and north of Lake Titicaca (not in field of view). Lima, Peru lies under the clouds just north of the clear coastal area. Because the high Andes have been uplifted 10,000 to 13,000 feet during the past 20 million years, the rivers which cut down to the Pacific Ocean have gorges almost that deep, such as the Rio Ocona at the bottom of the photograph. The eastern slopes of the Andes are heavily forested, forming the headwaters of the Amazon system. Smoke from burning in the Amazon basin fills river valleys on the right side of the photograph. A Linhof camera was used to take this view.

Geologic map of the Fort Morgan 7.5' quadrangle, Morgan County, Colorado

USGS Publications Warehouse

Berry, Margaret E.; Taylor, Emily M.; Slate, Janet L.; Paces, James B.; Hanson, Paul R.; Brandt, Theodore R.

2018-06-08

The Fort Morgan 7.5′ quadrangle is located on the semiarid plains of northeastern Colorado, along the South Platte River corridor where the river has incised into Upper Cretaceous Pierre Shale. The Pierre Shale is largely covered by surficial deposits that formed from alluvial, eolian, and hillslope processes operating in concert with environmental changes from the late Pliocene to the present. The South Platte River, originating high in the Colorado Rocky Mountains, has played a major role in shaping surficial geology in the map area, which is several tens of kilometers downstream from where headwater tributaries join the river. Recurrent glaciation (and deglaciation) of basin headwaters has affected river discharge and sediment supply far downstream, influencing deposition of alluvium and river incision in the Fort Morgan quadrangle. Distribution and characteristics of the alluvial deposits indicate that during the Pleistocene the course of the river within the map area shifted progressively southward as it incised, and by late middle Pleistocene the river was south of its present position, cutting and filling a deep paleochannel near the south edge of the quadrangle. The river shifted back to the north during the late Pleistocene. Kiowa and Bijou Creeks are unglaciated tributaries originating in the Colorado Piedmont east of the Front Range that also have played a major role in shaping surficial geology of the map area. Periodically during the late Pleistocene, major flood events on these tributaries deposited large volumes of sediment at and near their confluences, forming a broad, low-gradient fan composed of sidestream alluvium that could have occasionally dammed the river for short periods of time. Wildcat Creek, also originating on the Colorado Piedmont, and the small drainage of Cris Lee Draw dissect the map area north of the river. Eolian sand deposits of the Sterling (north of river) and Fort Morgan (south of river) dune fields cover much of the quadrangle and record past episodes of sand mobilization during times of prolonged drought. With the onset of irrigation and damming during historical times, the South Platte River has changed from a broad, shallow, and sandy braided river with highly variable seasonal discharge to a much narrower, deeper river with braided-meandering transition morphology and more uniform discharge.

Science to Manage a Very Rare Fish in a Very Large River - Pallid Sturgeon in the Missouri River, U.S.A.

NASA Astrophysics Data System (ADS)

Jacobson, R. B.; Colvin, M. E.; Marmorek, D.; Randall, M.

2017-12-01

The Missouri River Recovery Program (MRRP) seeks to revise river-management strategies to avoid jeopardizing the existence of three species: pallid sturgeon (Scaphirhynchus albus), interior least tern (Sterna antillarum)), and piping plover (Charadrius melodus). Managing the river to maintain populations of the two birds (terns and plovers) is relatively straightforward: reproductive success can be modeled with some certainty as a direct, increasing function of exposed sandbar area. In contrast, the pallid sturgeon inhabits the benthic zone of a deep, turbid river and many parts of its complex life history are not directly observable. Hence, pervasive uncertainties exist about what factors are limiting population growth and what management actions may reverse population declines. These uncertainties are being addressed by the MRRP through a multi-step process. The first step was an Effects Analysis (EA), which: documented what is known and unknown about the river and the species; documented quality and quantity of existing information; used an expert-driven process to develop conceptual ecological models and to prioritize management hypotheses; and developed quantitative models linking management actions (flows, channel reconfigurations, and stocking) to population responses. The EA led to development of a science and adaptive-management plan with prioritized allocation of investment among 4 levels of effort ranging from fundamental research to full implementation. The plan includes learning from robust, hypothesis-driven effectiveness monitoring for all actions, with statistically sound experimental designs, multiple metrics, and explicit decision criteria to guide management. Finally, the science plan has been fully integrated with a new adaptive-management structure that links science to decision makers. The reinvigorated investment in science stems from the understanding that costly river-management decisions are not socially or politically supportable without better understanding of how this endangered fish will respond. While some hypotheses can be evaluated without actually implementing management actions in the river, assessing the effectiveness of other forms of habitat restoration requires in-river implementation within a rigorous experimental design.

Long river profiles, tectonism, and eustasy: A guide to interpreting fluvial terraces

NASA Technical Reports Server (NTRS)

Merritts, Dorothy J.; Vincent, Kirk R.; Wohl, Ellen E.

1994-01-01

Along three rivers at the Mendocino triple junction, northern California, strath, cut, and fill terraces have formed in response to tectonic and eustatic processes. Detailed surveying and radiometric dating at multiple sites indicate that lower reaches of the rivers are dominated by the effects of oscillating sea level, primarily aggradation and formation of fill terraces during sea level high stands, alternating with deep incision during low stands. A eustasy-driven depositional wedge extends tens of kilometers upstream on all rivers (tapering to zero thickness). This distance is greater than expected from studies of the effects of check dams on much smaller streams elsewhere, due in part to the large size of these rivers. However, the change in gradient is nearly identical to other base level rise studies: the depositional gradient is about half that of the original channel. Middle to upper reaches of each river are dominated by the effects of long-term uplift, primarily lateral and vertical erosion and formation of steep, unpaired strath terraces exposed only upstream of the depositional wedge. Vertical incision at a rate similar to that of uplift has occurred even during the present sea level high stand along rivers with highest uplift rates. Strath terraces have steeper gradients than the modern channel bed and do not merge with marine terraces at the river mouth; consequently, they cannot be used to determine altitudes of sea level high stands. Strath formation is a continuous process of response to long-term uplift, and its occurrence varies spatially along a river depending on stream power, and hence position, upstream. Strath terraces are found only along certain parts of a coastal stream: upstream of the aggradational effects of oscillating sea level, and far enough downstream that stream power is in excess of that needed to transport the prevailing sediment load. For a given size river, the greater the uplift rate, the greater the rate of vertical incision and, consequently, the less the likelihood of strath terrace formation and preservation.

THE ABSOLUTE AGE OF THE UPPER PALEOLITHIC PERIOD (SOLUTREAN, GRAVETTIAN TYPE) IN THE REGION ADJOINING THE DNESTER RIVER, DETERMINED BY RADIOCARBON DATING (in Russian)

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

Ivanova, I.K.; Chernysh, A.P.

1963-01-11

Determination of the age of the dwellings of primitive man is of interest both from the point of view of the stratigraphy of quaternary deposits and for solving anthropogenetic problems. For this reason, radiocarbon dating techniques were used for layers containing paleolithic residue of Molodova V, located in a 200-m deep canyon at the right bank of the Dnester River in the Chernowith region. The measurements were carried out at a depth of 3.1 to 3.25 m from the surface. The age of layer VI was calculated at 23,000 plus or minus 800 years which is close to the agemore » reported for the Czechoslovak gravette and from samples from the French Abri plateau. Thus, radiocarbon dating results confirmed earlier findings obtained by topological means concerning the age of the region near the Dnester River. (TTT)« less

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

Payne, S. J.; Bruhn, D. F.; Hodges, J. M.

During 2012, the Idaho National Laboratory Seismic Monitoring Program evaluated 17,329 independent triggers that included earthquakes from around the world, the western United States, and local region of the Snake River Plain. Seismologists located 1,460 earthquakes and man-made blasts within and near the 161-km (or 100-mile) radius of the Idaho National Laboratory. Of these earthquakes, 16 had small-to-moderate size magnitudes (M) from 3.0 to 3.6. Within the 161-km radius, the majority of 695 earthquakes (M < 3.6) occurred in the active regions of the Basin and Range Provinces adjacent to the eastern Snake River Plain. Only 11 microearthquakes occurred withinmore » the Snake River Plain, four of which occurred in Craters of the Moon National Monument. The earthquakes had magnitudes from 1.0 to 1.7 and occurred at deep depths (11-24 km). Two events with magnitudes less than 1.0 occurred within the Idaho National Laboratory boundaries and had depths less than 10 km.« less

Deep Learning for Extreme Weather Detection

NASA Astrophysics Data System (ADS)

Prabhat, M.; Racah, E.; Biard, J.; Liu, Y.; Mudigonda, M.; Kashinath, K.; Beckham, C.; Maharaj, T.; Kahou, S.; Pal, C.; O'Brien, T. A.; Wehner, M. F.; Kunkel, K.; Collins, W. D.

2017-12-01

We will present our latest results from the application of Deep Learning methods for detecting, localizing and segmenting extreme weather patterns in climate data. We have successfully applied supervised convolutional architectures for the binary classification tasks of detecting tropical cyclones and atmospheric rivers in centered, cropped patches. We have subsequently extended our architecture to a semi-supervised formulation, which is capable of learning a unified representation of multiple weather patterns, predicting bounding boxes and object categories, and has the capability to detect novel patterns (w/ few, or no labels). We will briefly present our efforts in scaling the semi-supervised architecture to 9600 nodes of the Cori supercomputer, obtaining 15PF performance. Time permitting, we will highlight our efforts in pixel-level segmentation of weather patterns.

Migration of the Pee Dee River system inferred from ancestral paleochannels underlying the South Carolina Grand Strand and Long Bay inner shelf

USGS Publications Warehouse

Baldwin, W.E.; Morton, R.A.; Putney, T.R.; Katuna, M.P.; Harris, M.S.; Gayes, P.T.; Driscoll, N.W.; Denny, J.F.; Schwab, W.C.

2006-01-01

Several generations of the ancestral Pee Dee River system have been mapped beneath the South Carolina Grand Strand coastline and adjacent Long Bay inner shelf. Deep boreholes onshore and high-resolution seismic-reflection data offshore allow for reconstruction of these paleochannels, which formed during glacial lowstands, when the Pee Dee River system incised subaerially exposed coastal-plain and continental-shelf strata. Paleochannel groups, representing different generations of the system, decrease in age to the southwest, where the modern Pee Dee River merges with several coastal-plain tributaries at Winyah Bay, the southern terminus of Long Bay. Positions of the successive generational groups record a regional, southwestward migration of the river system that may have initiated during the late Pliocene. The migration was primarily driven by barrier-island deposition, resulting from the interaction of fluvial and shoreline processes during eustatic highstands. Structurally driven, subsurface paleotopography associated with the Mid-Carolina Platform High has also indirectly assisted in forcing this migration. These results provide a better understanding of the evolution of the region and help explain the lack of mobile sediment on the Long Bay inner shelf. Migration of the river system caused a profound change in sediment supply during the late Pleistocene. The abundant fluvial source that once fed sand-rich barrier islands was cut off and replaced with a limited source, supplied by erosion and reworking of former coastal deposits exposed at the shore and on the inner shelf.

A large-scale environmental flow experiment for riparian restoration in the Colorado River delta

USGS Publications Warehouse

Shafroth, Patrick B.; Schlatter, Karen; Gomez-Sapiens, Martha; Lundgren, Erick; Grabau, Matthew R.; Ramirez-Hernandez, Jorge; Rodriguez-Burgeueno, J. Eliana; Flessa, Karl W.

2017-01-01

Managing streamflow is a widely-advocated approach to provide conditions necessary for seed germination and seedling establishment of trees in the willow family (Salicaceae). Experimental flow releases to the Colorado River delta in 2014 had a primary objective of promoting seedling establishment of Fremont cottonwood (Populus fremontii) and Goodding's willow (Salix gooddingii). We assessed seed germination and seedling establishment of these taxa as well as the non-native tamarisk (Tamarix spp.) and native seepwillow shrubs (Baccharis spp.) in the context of seedling requirements and active land management (land grading, vegetation removal) at 23 study sites along 87 river km. In the absence of associated active land management, experimental flows to the Colorado River delta were minimally successful at promoting establishment of new woody riparian seedlings, except for non-native Tamarix. Our results suggest that the primary factors contributing to low seedling establishment varied across space, but included low or no seed availability in some locations for some taxa, insufficient soil moisture availability during the growing season indicated by deep groundwater tables, and competition from adjacent vegetation (and, conversely, availability of bare ground). Active land management to create bare ground and favorable land grades contributed to significantly higher rates of Salicaceae seedling establishment in a river reach with high groundwater tables. Our results provide insights that can inform future environmental flow deliveries to the Colorado River delta and its ecosystems and other similar efforts to restore Salicaceae taxa around the world.

Identification of the Spawning, Rearing, and Migratory Requirements of Fall Chinook Salmon in the Columbia River Basin, Annual Report 1994.

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

Rondorf, Dennis W.; Tiffan, Kenneth F.

1996-08-01

Spawning ground surveys were conducted in 1994 as part of a five year study of Snake River chinook salmon Oncorhynchus tshawyacha begun in 1991. Observations of fall chinook salmon spawning in the Snake River were limited to infrequent aerial red counts in the years prior to 1987. From 1987-1990, red counts were made on a limited basis by an interagency team and reported by the Washington Department of Fisheries. Starting in 1991, the U.S. Fish and Wildlife Service (USFWS), and other cooperating agencies and organizations, expanded the scope of spawning ground surveys to include: (1) additional aerial surveys to improvemore » red counts and provide data on the timing of spawning; (2) the validation (ground truthing) of red counts from aerial surveys to improve count accuracy; (3) underwater searches to locate reds in water too deep to allow detection from the air; and (4) bathymetric mapping of spawning sites for characterizing spawning habitat. This document is the 1994 annual progress report for selected studies of fall chinook salmon. The studies were undertaken because of the growing concern about the declining salmon population in the Snake River basin.« less

Use of map analysis to elucidate flooding in an Australian Riparian River Red Gum Forest

NASA Astrophysics Data System (ADS)

Bren, L. J.; O'Neill, I. C.; Gibbs, N. L.

1988-07-01

Red gum (Eucalyptus camaldulensis) forests occur on extensive floodplains along the river Murray in Australia. This type of forest is unusual because of its high quality in a semiarid area, the absence of woody species other than red gum, and its survival on a deep, intractable, swelling clay soil of depths exceeding 20 m. This soil probably acts as an aquiclude. The forests require flooding to thrive and regenerate. For many years there has been speculation that irrigation regulation of the river was reducing forest flooding. A grid cell analysis of flood maps of areas flooded over a period of 22 years showed that vegetation communities and forest site quality were statistically related to the flood frequencies of sites. The percentage of forest inundated was dependent on the peak daily flow during the period of inundation. A historical analysis of the estimated percentage of forest inundated showed a substantial influence of river regulation on both timing and extent of inundation. Estimates of historical floodings showed that the environment is one that changes rapidly from wetland to dry land. Although not without limitations, the analysis produced information not available from other sources.

Mercury and arsenic in the gold mining regions of the Ankobra River basin in Ghana

NASA Astrophysics Data System (ADS)

Bannerman, W.; Potin-Gautier, M.; Amoureux, D.; Tellier, S.; Rambaud, A.; Babut, M.; Adimado, A.; Beinhoff, C.

2003-05-01

The river Ankobra flows through the principal gold mining centres in Western Ghana, draining a total area of 8272 km^2 to join the Atlantic ocean. Mercury is used by thousands of small-scale miners in the region to amalgamate gold. Ores mined in some deep shafts and surface mines are arsenopyrites and the region is marked by the presence of heaps of arsenic - rich mine tailings from both past and recent activities. This study was conducted to assess the impact of mining activities on the distribution and speciation of arsenic and mercury in the aquatic environment of the Ankobra River. In all, water (filtered and non-filtered) and bed sediments were collected from various locations within the watershed. Principal parameters investigated include total mercury, arsenic (III), arsenic (V), monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA). Seasonal and spatial variations of these parameters were investigated. Quality control systems were adopted at both the environmental and analytical stages of the study. ln general, areas close to the mining centres are the most pollilited. As (V)/As (III) ratios in water are reversed after the first 100-km of the river length with the onset of industrial influence downstream.

River Gardens Intermediate-Care Facility water-to-air heating and air-conditioning demonstration project. Final report

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

Brown, R.C.

An integrated system of heat pumps is used to reject heat into or extract heat from circulating water from a shallow well adjacent to the river to demonstrate the efficiency and fuel cost savings of water-to-air heat pumps, without the expense of drilling a deep well. Water is returned unpolluted to the Guadalupe River and is circulated through a five-building complex at River Gardens Intermediate Care Facility for the Mentally Retarded in New Braunfels, Texas. The water is used as a heat source or sink for 122 heat pumps providing space heating and cooling, and for refrigeration and freezer units.more » The system was not installed as designed, which resulted in water pumping loads being higher than the original design. Electrical consumption for pumping water represented 36 to 37% of system electrical consumption. Without the water pumping load, the water-to-air system was an average of 25% more efficient in heating than a comparable air-to-air unit with resistance heating. With water pumping load included, the installed system averaged 17% less efficient in cooling and 19% more efficient in heating than the comparable unit.« less

Repeated trans-watershed hybridization among haplochromine cichlids (Cichlidae) was triggered by Neogene landscape evolution.

PubMed

Schwarzer, Julia; Swartz, Ernst Roelof; Vreven, Emmanuel; Snoeks, Jos; Cotterill, Fenton Peter David; Misof, Bernhard; Schliewen, Ulrich Kurt

2012-11-07

The megadiverse haplochromine cichlid radiations of the East African lakes, famous examples of explosive speciation and adaptive radiation, are according to recent studies, introgressed by different riverine lineages. This study is based on the first comprehensive mitochondrial and nuclear DNA dataset from extensive sampling of riverine haplochromine cichlids. It includes species from the lower River Congo and Angolan (River Kwanza) drainages. Reconstruction of phylogenetic hypotheses revealed the paradox of clearly discordant phylogenetic signals. Closely related mtDNA haplotypes are distributed thousands of kilometres apart and across major African watersheds, whereas some neighbouring species carry drastically divergent mtDNA haplotypes. At shallow and deep phylogenetic layers, strong signals of hybridization are attributed to the complex Late Miocene/Early Pliocene palaeohistory of African rivers. Hybridization of multiple lineages across changing watersheds shaped each of the major haplochromine radiations in lakes Tanganyika, Victoria, Malawi and the Kalahari Palaeolakes, as well as a miniature species flock in the Congo basin (River Fwa). On the basis of our results, introgression occurred not only on a spatially restricted scale, but massively over almost the whole range of the haplochromine distribution. This provides an alternative view on the origin and exceptional high diversity of this enigmatic vertebrate group.

The Black Canyon of the Gunnison: Today and Yesterday

USGS Publications Warehouse

Hansen, Wallace R.

1965-01-01

Since the early visit of Captain John William Gunnison in the middle of the last century, the Black Canyon of the Gunnison has stirred mixed apprehension and wonder in the hearts of its viewers. It ranks high among the more awesome gorges of North America. Many great western canyons are as well remembered for their brightly colored walls as for their airy depths. Not so the Black Canyon. Though it is assuredly not black, the dark-gray tones of its walls and the hazy shadows of its gloomy depths join together to make its name well deserved. Its name conveys an impression, not a picture. After the first emotional impact of the canyon, the same questions come to the minds of most reflective viewers and in about the following order: How deep is the Black Canyon, how wide, how does it compare with other canyons, what are the rocks, how did it form, and how long did it take? Several western canyons exceed the Black Canyon in overall size. Some are longer; some are deeper; some are narrower; and a few have walls as steep. But no other canyon in North American combines the depth, narrowness, sheerness, and somber countenance of the Black Canyon. In many places the Black Canyon is as deep as it is wide. Between The Narrows and Chasm View in the Black Canyon of the Gunnison National Monument (fig. 15) it is much deeper than wide. Average depth in the monument is about 2,000 feet, ranging from a maximum of about 2,700 feet, north of Warner Point (which also is the greatest depth anywhere in the canyon), to a minimum of about 1,750 feet at The Narrows. The stretch of canyon between Pulpit Rock and Chasm View, including The Narrows, though the shallowest in the monument, is also the narrowest, has some of the steepest walls, and is, therefore, among the most impressive segments of the canyon (fig. 3). Profiles of several well-known western canyons are shown in figure 1. Deepest of these by far is Hells Canyon of the Snake, on the Idaho-Oregon border. Clearly, it dwarfs the Black Canyon in the immensity of its void, though its flaring walls lack the alarming verticality of the Black Canyon. Arizona's Grand Canyon of the Colorado is acknowledged as the greatest of them all; it is not as deep as Hells Canyon, but it is wider, longer, more rugged, and far more colorful. Its depth is two to three times that of the Black Canyon. Zion Canyon, Utah, combines depth, sheerness, serenity, and color in a chasm that ranges from capacious to extremely narrow. Its Narrows have a depth-to-width ratio unmatched by any other major American canyon. California's Yosemite Valley, in a setting of sylvan verdure, is unique among the gorges shown in profile in figure 1 in being the only glacial trough; its monolithic walls bear witness to the abrasive power of moving ice. Few cliffs in the world match the splendor of its El Capitan. Lodore Canyon, on the Green River in Dinosaur National Monument, Colorado, is best known, perhaps, for its noisy splashy rapids, first made famous by John Wesley Powell. Lodore Canyon also features towering cliffs of deep-red quartzite. Grand Canyon of the Yellowstone River, Wyoming, is noted for its great waterfalls, dashing river, and bright coloration. The Royal Gorge of the Arkansas River, Colorado, features the 'world's highest suspension bridge'. The profiles shown in figure 1 afford some basis for comparing one canyon with another. They cannot abstract in two dimensions the overall impression that each canyon makes. Color, vegetation, outcrop habit, vantage point, season of year, length of visit - even the roar of the river or lack thereof - all contribute to this highly personal effect. For a river of its size, the Gunnison has an unusually steep gradient through the Black Canyon. The river falls about 2,150 feet from the head of the canyon at Sapinero to the mouth at its junction with North Fork - a distance of about 50 miles and an average rate of fall of about 43 feet per mile. By comparison, the Green

Detailed measured sections, cross sections, and paleogeographic reconstructions of the upper cretaceous and lower tertiary nonmarine interval, Wind River Basin, Wyoming: Chapter 10 in Petroleum systems and geologic assessment of oil and gas resources in the Wind River Basin Province, Wyoming

USGS Publications Warehouse

Johnson, Ronald C.

2007-01-01

Detailed measured sections and regional stratigraphic cross sections are used to reconstruct facies maps and interpret paleogeographic settings for the interval from the base of Upper Cretaceous Mesaverde Formation to top of lower member of the Paleocene Fort Union Formation in the Wind River Basin, Wyoming. The Mesaverde Formation spans the time during which the Upper Cretaceous seaway retreated eastward out of central Wyoming in Campanian time and the initial stages of the Lewis transgression in earliest Maastrichtian time. This retreat stalled for a considerable period of time during deposition of the lower part of the Mesaverde, creating a thick buildup of marginal marine sandstones and coaly coastal plain deposits across the western part of the basin. The Lewis sea transgressed into the northeast part of Wind River Basin, beginning in early Maastrichtian time during deposition of the Teapot Sandstone Member of the Mesaverde Formation. The Meeteetse Formation, which overlies the Teapot, was deposited in a poorly-drained coastal plain setting southwest of the Lewis seaway. The Lewis seaway, at maximum transgression, covered much of the northeast half of the Wind River Basin area but was clearly deflected around the present site of the Wind River Range, southwest of the basin, providing the first direct evidence of Laramide uplift on that range. Uplift of the Wind River Range continued during deposition of the overlying Maastrichtian Lance Formation. The Granite Mountains south of the basin also became a positive feature during this time. A rapidly subsiding trough during the Maastrichtian time formed near the presentday trough of the Wind River Basin in which more than 6,000 feet of Lance was deposited. The development of this trough appears to have begun before the adjacent Owl Creek Mountains to the north started to rise; however, a muddy facies in the upper part of Lance in the deep subsurface, just to the south, might be interpreted to indicate that the Cretaceous Cody Shale was being eroded off a rising Owl Creek Mountains in latest Cretaceous time. The Paleocene Fort Union Formation unconformably overlies older units but with only slight angular discordance around much of the margins of the Wind River Basin. Pre-Fort Union erosion was most pronounced toward the Wind River Range to the southwest, where the Fort Union ultimately overlies strata as old as the upper part of the Cretaceous Cody Shale. The unconformity appears to die out toward the basin center. Coal-forming mires developed throughout the western part of the basin near the beginning of the Paleocene. River systems entering the basin from the Wind River Range to the southwest and the Granite Mountains to the south produced areas of sandy fluvial deposition along mountain fronts. A major river system appears to have entered the basin from about the same spot along the Wind River Range throughout much of the Paleocene, probably because it became incised and could not migrate laterally. The muddy floodplain facies that developed along the deep basin trough during latest Cretaceous time, expanded during the early part of the Paleocene. Coal-forming mires that characterize part of the lower Fort Union Formation reached maximum extent near the beginning of the late Paleocene and just prior to the initial transgression of Lake Waltman. From the time of initial flooding, Lake Waltman expanded rapidly, drowning the coal-forming mires in the central part of the basin and spreading to near basin margins. Outcrop studies along the south margin of the basin document that once maximum transgression was reached, the lake was rapidly pushed basinward and replaced by fluvial environments.

Seasonal use of shallow water habitat in the Lower Snake River reservoirs by juvenile fall Chinook salmon

USGS Publications Warehouse

Tiffan, Kenneth F.; Connor, William P.

2012-01-01

The U.S. Army Corps of Engineers (COE) is preparing a long term management plan for sediments that affect the authorized project purposes of the Lower Granite, Little Goose, Lower Monumental, and Ice Harbor reservoirs (hereafter, the lower Snake River reservoirs), and the area from the mouth of the Snake River to Ice Harbor Dam. We conducted a study from spring 2010 through winter 2011 to describe the habitat use by juvenile Chinook salmon within a selected group of shallow water habitat complexes (< 6 m deep) in the lower Snake River reservoirs to help inform the long-term plan. Natural fry and parr were present within all four shallow water habitat complexes that we studied from early spring through early summer, and parr ( = 40,345 ± 18,800 [error bound]) were more abundant than fry ( = 24,615 ± 5,701). Water < 2 m deep was highly used for rearing by natural fall Chinook salmon subyearlings (fry and parr combined; hereafter natural subyearlings) based on duration of use and relative group abundances during spring and summer, whereas the 2–6 m depth interval was more highly used by migratory hatchery fall Chinook salmon subyearlings and spring, summer, and fall Chinook salmon yearlings. Overall mean spring-summer apparent density of natural subyearlings was 15.5 times higher within the < 2 m depth interval than within the 2–6 m depth interval. Density of natural subyearlings also decreased as the distance a given shallow water habitat complex was located from the riverine spawning areas increased. Reservoir-type juveniles (or fish likely destined to become reservoir-type juveniles) were present in the lower Snake River reservoirs from fall 2010 through winter 2011; however, use of shallow water habitat by reservoir-type juveniles was limited during our study. We only collected 38 reservoir-type juveniles in shallow water habitat sites in beach and lampara seines during the fall. Radiotelemetry data revealed that though many tagged fish passed shallow water habitat sites, relatively few fish entered them and the median time fish spent within a given site was less than 1.4 h. Fish located by mobile tracking away from study sites were pelagically oriented, and generally not found over shallow water or close to shore. The findings in this report: (1) support the selection of natural fall Chinook subyearlings as the indicator group for determining the potential benefits of using dredge spoils to create shallow water habitat, (2) provide evidence for shallow water habitat use by natural subyearlings, (3) provide evidence against large-scale use of shallow water habitat by reservoir-type juveniles, (4) suggest that the depth criterion for defining shallow water habitat (i.e., < 6 m deep) warrants reconsideration, and (5) provide guidance for when to dredge and create shallow water habitat. Future research on habitat preference, feeding ecology, the food web, and intra-specific competition would help to better inform the long-term management plan.

Border Protection and National Security of Mongolia

DTIC Science & Technology

2006-09-01

Annals of the Association of American Geographers 49:3 (1959): 241–55. 11 These boundaries often correspond to the natural steppe versus cultivated... natural resources (oil, fertile land, or water) within the territory, physical characteristics (a deep-water port or a defensible ridge line), or a... natural boundaries and artificial boundaries. Lines marked by nature , such as mountain crests, rivers, and the shore lines of lakes and seas, have long

75 FR 52520 - White River Hydro, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-26

...) a 12-foot-diameter, 2,842-foot-long concrete tunnel; (10) a 73-foot-deep forebay; (11) three 5.4- to... Internet. See 18 CFR 385.2001(a)(1)(iii) and the instructions on the Commission's Web site http://www.ferc... Commission's Web site at http://www.ferc.gov/docs-filing/elibrary.asp . Enter the docket number (P-13804) in...

Mudpuppy (Necturus maculosus maculosus ) spatial distribution, breeding water depth, and use of artificial spawning habitat in the Detroit River

USGS Publications Warehouse

Craig, Jaquelyn M.; Mifsud, David A.; Briggs, Andrew S.; Boase, James C.; Kennedy, Gregory W.

2015-01-01

Mudpuppy (Necturus maculosus maculosus) populations have been declining in the Great Lakes region of North America. However, during fisheries assessments in the Detroit River, we documented Mudpuppy reproduction when we collected all life stages from egg through adult as by-catch in fisheries assessments. Ten years of fisheries sampling resulted in two occurrences of Mudpuppy egg collection and 411 Mudpuppies ranging in size from 37–392 mm Total Length, collected from water 3.5–15.1 m deep. Different types of fisheries gear collected specific life stages; spawning females used cement structures for egg deposition, larval Mudpuppies found refuge in eggmats, and we caught adults with baited setlines and minnow traps. Based on logistic regression models for setlines and minnow traps, there was a higher probability of catching adult Mudpuppies at lower temperatures and in shallower water with reduced clarity. In addition to documenting the presence of all life stages of this sensitive species in a deep and fast-flowing connecting channel, we were also able to show that standard fisheries research equipment can be used for Mudpuppy research in areas not typically sampled in herpetological studies. Our observations show that typical fisheries assessments and gear can play an important role in data collection for Mudpuppy population and spawning assessments.

Deep Geothermal Reservoir Temperatures in the Eastern Snake River Plain, Idaho using Multicomponent Geothermometry

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

Ghanashyam Neupane; Earl D. Mattson; Travis L. McLing

2014-02-01

The U.S. Geological survey has estimated that there are up to 4,900 MWe of undiscovered geothermal resources and 92,000 MWe of enhanced geothermal potential within the state of Idaho. Of particular interest are the resources of the Eastern Snake River Plain (ESRP) which was formed by volcanic activity associated with the relative movement of the Yellowstone Hot Spot across the state of Idaho. This region is characterized by a high geothermal gradient and thermal springs occurring along the margins of the ESRP. Masking much of the deep thermal potential of the ESRP is a regionally extensive and productive cold-water aquifer.more » We have undertaken a study to infer the temperature of the geothermal system hidden beneath the cold-water aquifer of the ESRP. Our approach is to estimate reservoir temperatures from measured water compositions using an inverse modeling technique (RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. In the initial stages of this study, we apply the RTEst model to water compositions measured from a limited number of wells and thermal springs to estimate the regionally extensive geothermal system in the ESRP.« less

Mercury on a landscape scale—Balancing regional export with wildlife health

USGS Publications Warehouse

Marvin-DiPasquale, Mark C.; Windham-Myers, Lisamarie; Fleck, Jacob A.; Ackerman, Joshua T.; Eagles-Smith, Collin A.; McQuillen, Harry

2018-06-26

The Cosumnes River watershed requires a 57–64 percent reduction in loads to meet the new Delta methylmercury (MeHg) total maximum daily load allocation, established by the Central Valley Regional Water Quality Control Board. Because there are no large point sources of MeHg in the watershed, the focus of MeHg load reductions will fall upon non-point sources, particularly the expansive wetlands considered to be a primary source of MeHg in the region. Few management practices have been implemented and tested in order to meet load reductions in managed wetlands, but recent efforts have shown promise. This project examines a treatment approach to reduce MeHg loads to the Sacramento-San Joaquin River Delta by creating open-water deep cells with a small footprint at the downstream end of wetlands to promote net demethylation of MeHg and to minimize MeHg and Hg loads exiting wetlands at the Cosumnes River Preserve. Specifically, the deep cells were were located immediately up gradient of the wetland’s outflow weir and were deep enough (75–91 centimeter depth) to be vegetation-free. The topographic and hydrologic structure of each treatment wetland was modified to include open-water deep cells so that the removal of aqueous MeHg might be enhanced through (1) particle settling, (2) photo-degradation, and (3) benthic microbial demethylation. These deep cells were, therefore, expected to clean MeHg from surface water prior to its discharge to the Cosumnes River and the downstream Delta.Our goal was to test whether the implementation of the deep cells within wetlands would minimize MeHg and total Hg export. Further, we sought to test whether continuous flow-through hydrology, would lower MeHg concentrations in resident biota, compared to traditional wetland management operations. The dominant practice in seasonal wetlands management is the “fill-and-maintain” approach, in which wetlands are filled with water and the water levels maintained without substantial draining until drawdown. Our approach was to create and characterize replicate treatment wetland complexes, in conjunction with monitoring of hydrologic, biologic, and chemical indicators of MeHg exposure for two full annual cycles within winter-spring flooded seasonal wetlands. In addition to the creation of deep cells within treatment wetlands, hydrology was manipulated so that there was a constant flow-through of water, while the control wetlands utilized the fill-and-maintain approach. Specifically, the treatment wetlands were maintained in a flow-through manner, while the control wetlands were maintained in a fill-and-maintain manner from September through May, to test the hypothesis that the flow of water through the seasonal wetland can lower fish bioaccumulation through dilution of MeHg-concentrated water within the wetland by constant inflows of water into the wetland.The major tasks of this study included: (1) field design and implementation, (2) water and wetland management, (3) hydrologic monitoring and water quality sampling, (4) MeHg export and load estimates, (5) caged fish experiments for examining MeHg bioaccumulation, (6) site and process characterization to improve understanding and transferability of results, (7) adaptive management, transferability, and outreach, and (8) reporting of results and conclusions. This report summarizes the key findings of this study, which focuses on MeHg load estimates from control and treatment wetlands, quantification of three MeHg removal mechanisms (particulate settling, benthic demethylation, and photo-demethylation) in the deep cells within the treatment wetlands, and MeHg bioaccumulation in wetland fishes.Key findings include:Over two years of study, mean whole-water MeHg load decreased 37 percent in deep cells, when comparing inlet of check weir flows to outlet.Of the 37 percent MeHg load removed within the deep cell, photodegradation accounted for 7 percent and particle flux to the benthos accounted for 24 percent of the mass removed, with the remaining 6 percent apparent MeHg loss unexplained.Benthic MeHg degradation did not appear to be a major MeHg removal process in the deep cells, as changes in the ambient MeHg pool over 7-day bottle incubations showed that the surface sediment exhibited net MeHg production in the majority (87 percent) of incubation experiments. In only 13 percent of the incubations (3 out of 24) was net MeHg degradation observed.Estimates of benthic diffusive flux of MeHg across the sediment/water interface were small relative to particulate flux and variable (positive or negative), suggesting this is likely a minor term in the overall MeHg budget within the deep cells.Although the deep cells served as net MeHg sink overall, MeHg export from the flow-through treatment wetlands (shallow and deep combined) exceeded export from the fill-and-maintain managed control wetlands, because of the differences in hydrologic management between the two wetland types.Shallow wetlands under flow-through conditions generated a net export of MeHg.Most of the annual MeHg export from the treatment wetlands occurred within the first 3 months of flood up (September to November), shortly after hydrologic management began.Despite the effectiveness of the deep cell in lowering MeHg export concentrations, total mercury (THg) concentration did not decrease in biosentinel fish (Gambusia affinis, Mosquitofish) between the deep cell inlet and outlet.Mosquitofish THg concentrations were higher in treatment wetlands than in control wetlands during the first year of study, likely because of an associated increase in MeHg availability immediately following wetland construction activities. Mosquitofish THg concentrations declined in the treatment wetlands during the second year of study, and fish THg concentrations in treatment wetlands were no different from those in the control.Similarly, the increased hydrologic flow rates in the treatment wetlands did not lower fish THg concentrations nor aqueous MeHg concentrations in the shallow cells, suggesting that MeHg flux from the sediment to water column exceeded the flow-through flushing rate in the shallow portion of the treatment wetlands.Reductions in MeHg concentrations of surface water and fish may require higher flow rates than used in the study to achieve the region’s regulatory goals. However, the flow rates necessary may not be feasible for these managed wetlands because of limited water supply and the associated costs for water and pumping.The use of deep cells in seasonal wetlands were effective in lowering MeHg exports under continuous water flow-through hydrology. However, fill-and-maintain hydrology had lower exports overall, because of a single major drainage event at the end of the flood season.Future studies focused on limiting MeHg export should consider combining deep cells with the fill-and-maintain or fill-and-trickle hydrologic management approach.

Landslides triggered by the October 8, 2005, Pakistan earthquake and associated landslide-dammed reservoirs

USGS Publications Warehouse

Harp, Edwin L.; Crone, Anthony J.

2006-01-01

The October 8, 2005, Kashmir earthquake (M 7.6) triggered several thousand landslides, mainly rock falls and rock slides, in the epicentral area near the cities of Muzafarrabad and Balakot, Pakistan. Most of these were shallow, coalescing rock slides emanating from highly sheared and deformed limestone and dolomite of the Precambrian Muzafarrabad Formation. The largest landslide triggered by the earthquake is located approximately 32 kilometers southeast of Muzafarrabad in a tributary valley of the Jhelum River. This landslide is a debris avalanche of approximately 80 million cubic meters volume within the Miocene Murree Formation consisting of mixed sandstone, mudstone, shale, and limestone. The avalanche buried the village of Dandbeh and resulted in approximately 1,000 fatalities, according to local residents. The avalanche deposit traveled approximately 1.5 kilometers downslope and 300 meters or more up the opposite slope in the adjacent Karli stream drainage and also extended into the Tang stream drainage where the Tang stream joins the Karli drainage. The landslide mass has impounded two lakes within the blocked drainages. The lake in the Karli drainage was approximately 800 meters long and 20 meters deep as of December 19, 2005. The lake in the Tang drainage was approximately 400 meters long and 10 meters deep as of this same date. Downstream populations are at risk from possible flash flooding when these debris dams are overtopped by the reservoir water. The closest village, Hattian, is 2.8 kilometers downstream at the junction of the Jhelum River and the landslide-dammed Karli tributary. Other populations along the Jhelum River may also be at risk. Pakistan military engineers are preparing to construct a spillway within the landslide deposits to lessen the severity of the flood if the lake in the Karli stream drainage breaches the landslide dam catastrophically.

Effects of cooking on radiocesium in fish from the Savannah River: exposure differences for the public.

PubMed

Burger, Joanna; Gaines, Karen F; Boring, C Shane; Snodgrass, J; Stephens, W L; Gochfeld, M

2004-02-01

Understanding the factors that contribute to the risk from fish consumption is an important public health concern because of potential adverse effects of radionuclides, organochlorines, other pesticides, and mercury. Risk from consumption is normally computed on the basis of contaminant levels in fish, meal frequency, and meal size, yet cooking practices may also affect risk. This study examines the effect of deep-frying on radiocesium (137Cs) levels and risk to people fishing along the Savannah River. South Carolina and Georgia have issued consumption advisories for the Savannah River, based partly on 137Cs. 137Cs levels were significantly higher in the cooked fish compared to the raw fish on a wet weight basis. Mean 137Cs levels were 0.61 pCi/g (wet weight basis) in raw fish, 0.81 pCi/g in cooked-breaded, and 0.99 pCi/g in cooked-unbreaded fish. Deep-frying with and without breading resulted in a weight loss of 25 and 39%, while 137Cs levels increased by 32 and 62%, respectively. Therefore, the differences were due mainly to weight loss during cooking. However, the data suggest that risk assessments should be based on cooked portion size for contaminant analysis, or the risk from 137Cs in fish will be underestimated. People are likely to estimate the amounts of fish they eat based on a meal size of the cooked portion, while risk assessors determine 137Cs levels in raw fish. A conversion factor of at least two for 137Cs increase during cooking is reasonable and conservative, given the variability in 137Cs levels. The data also suggest that surveys determining consumption should specifically ask about portion size before or after cooking and state which was used in their methods.

Genesis of Miocene litho-stratigraphic trap and hydrocarbon accumulation in the Qiongdongnan Basin, northern South China Sea

NASA Astrophysics Data System (ADS)

Fan, Caiwei; Jiang, Tao; Liu, Kun; Tan, Jiancai; Li, Hu; Li, Anqi

2018-12-01

In recent years, several large gas fields have been discovered in western Qiongdongnan Basin. It is important and necessary to illustrate their sedimentary characteristics and hydrocarbon migration so that more gas fields could be discovered in the future. Previous regional tectonic-sedimentary researchers show that large-scale source rock of the Yacheng Formation developed in the Ledong and Lingshui sags due to the Red River Fault pull-apart strike slip in early Oligocene. The main targets for hydrocarbon exploration in this area are the Miocene deep water reservoirs. In late Miocene, the Huangliu Formation reservoirs are composed of the early channels which were sourced by river systems in Hainan uplift and the consequent channels were sourced by Qiupen River in Kunsong uplift. Both axial channels exhibit unique spatial distribution patterns and geometries. The other kind of reservoir developed in the middle Miocene Meishan Formation, which compose of slope break-controlled submarine fan. They can be further classified into three types—slope channelized fan, basin floor fan, and bottom current reworked fan. The various fans have different reservoir quality. These two kinds of reservoirs contribute to four types of litho-stratigraphic traps under the actions of sedimentation and subsidence. The overpressure caused by hydrocarbon generation can fracture deeper strata and result in regional fractured network for hydrocarbon migration. Therefore, free gas driven by overpressure and buoyancy force can be migrated into Miocene litho-stratigraphic traps to accumulate. The revealed genesis of Miocene lithologic trap and hydrocarbon accumulation in the Qiongdongnan Basin would greatly contribute to the further hydrocarbon exploration in northern South China Sea and can be helpful for other deep water areas around the world.

Evaluating LSM-Based Water Budgets Over a West African Basin Assisted with a River Routing Scheme

NASA Technical Reports Server (NTRS)

Getirana, Augusto C. V.; Boone, Aaron; Peugeot, Christophe

2014-01-01

Within the framework of the African Monsoon Multidisciplinary Analysis (AMMA) Land Surface Model Intercomparison Project phase 2 (ALMIP-2), this study evaluates the water balance simulated by the Interactions between Soil, Biosphere, and Atmosphere (ISBA) over the upper Oum River basin, in Benin, using a mesoscale river routing scheme (RRS). The RRS is based on the nonlinear Muskingum Cunge method coupled with two linear reservoirs that simulate the time delay of both surface runoff and base flow that are produced by land surface models. On the basis of the evidence of a deep water-table recharge in that region,a reservoir representing the deep-water infiltration (DWI) is introduced. The hydrological processes of the basin are simulated for the 2005-08 AMMA field campaign period during which rainfall and stream flow data were intensively collected over the study area. Optimal RRS parameter sets were determined for three optimization experiments that were performed using daily stream flow at five gauges within the basin. Results demonstrate that the RRS simulates stream flow at all gauges with relative errors varying from -22% to 3% and Nash-Sutcliffe coefficients varying from 0.62 to 0.90. DWI varies from 24% to 67% of the base flow as a function of the sub-basin. The relatively simple reservoir DWI approach is quite robust, and further improvements would likely necessitate more complex solutions (e.g., considering seasonality and soil type in ISBA); thus, such modifications are recommended for future studies. Although the evaluation shows that the simulated stream flows are generally satisfactory, further field investigations are necessary to confirm some of the model assumptions.

Seasonal Dynamics of Dissolved Organic Carbon Under Complex Circulation Schemes on a Large Continental Shelf: The Northern South China Sea

NASA Astrophysics Data System (ADS)

Meng, Feifei; Dai, Minhan; Cao, Zhimian; Wu, Kai; Zhao, Xiaozheng; Li, Xiaolin; Chen, Junhui; Gan, Jianping

2017-12-01

We examined the distribution and seasonality of dissolved organic carbon (DOC) based on a large data set collected from the northern South China Sea (NSCS) shelf under complex circulation schemes influenced by river plume, coastal upwelling, and downwelling. The highest surface values of ˜117 μmol L-1 were observed nearshore in summer suggesting high DOC supplies from the river inputs, whereas the lowest surface values of ˜62 μmol L-1 were on the outer shelf in winter due to entrainment of DOC-poor subsurface water under strengthened vertical mixing. While the summer coastal upwelling brought lower DOC from offshore depth to the nearshore surface, the winter coastal downwelling delivered higher surface DOC to the midshelf deep waters from the inner shelf fueled by the China Coastal Current (CCC) transporting relatively high DOC from the East China Sea to the NSCS. The intensified winter downwelling generated a cross-shelf DOC transport of 3.1 × 1012 g C over a large shelf area, which induced a significant depression of the NSCS DOC inventory in winter relative to in autumn. In addition to the variable physical controls, net biological production of DOC was semiquantified in both the river plume (2.8 ± 3.0 μmol L-1) and coastal upwelling (3.1 ± 1.3 μmol L-1) in summer. We demonstrated that the NSCS shelf had various origins of DOC including riverine inputs, inter-shelf transport and in situ production. Via cross-shelf transport, the accumulated DOC would be exported to and stored in the deep ocean, suggesting that continental shelves are a potentially effective carbon sink.

Multiyear Downstream Response to Dam Removal on the White Salmon River, WA

NASA Astrophysics Data System (ADS)

Wilcox, A. C.; O'Connor, J. E.; Major, J. J.

2017-12-01

The 2011 removal of the 38 m tall Condit Dam on the White Salmon River, Washington was one of the largest dam removals to date, in terms of both dam height and sediment release. We examined the multiyear geomorphic response to this event, through 2015, including in a bedrock-confined canyon and in a less-confined, backwater-influenced pool reach near the river's mouth, to the large, rapid influx of fine reservoir sediment produced by the breach and to subsequent sediment transfer in the free-flowing White Salmon River. In the canyon reach, aggraded sediments were rapidly eroded from riffles, returning them toward pre-breach bed elevations within weeks, but pool aggradation persisted for longer. The downstream, less-confined reach transformed from a deep pool to a narrower pool-riffle channel with alternate bars; multiyear observations showed persistence of bars and of this new and distinct morphology. This downstream reach marks a rare case in post-dam removal channel response; in most dam removals, channels have rapidly reverted toward pre-removal morphology, as in the canyon reach here. Comparison of the multiyear geomorphic evolution of the White Salmon River to other recent large dam removals in the U.S. allows evaluation of the relative influences of antecedent channel morphology, post-breach hydrology, and dam removal style, as well as providing a basis for predicting responses to future dam removals.

Pore-fluid chemistry along the main axis of an active lobe at the Congo deep-sea fan

NASA Astrophysics Data System (ADS)

Croguennec, C.; Ruffine, L.; Guyader, V.; Le Bruchec, J.; Ruesch, B.; Caprais, J.; Cathalot, C.; de Prunelé, A.; Germain, Y.; Bollinger, C.; Dennielou, B.; Olu, K.; Rabouille, C.

2013-12-01

The distal lobes of the Congo deep-sea fan constitute a unique in situ laboratory to study early diagenesis of marine sediments. They are located at water depth of about 5000 m and result from the deposition of sediment transported by turbidity currents along the channel-levee systems and submarine canyon connected to the Congo River. Thus, a huge amount of organic matter, transported from the river to the lobes, undergoes decomposition processes involving different oxidants present within the sedimentary column. This drastically changes the chemistry of the pore fluids, allowing the occurence of a succession of biogeochemical processes. The present study is part of an ongoing project which aims at better understanding the role and the fate of organic matter transported to the lobe systems, as well as its implication in the distribution of the living communities encountered there. Thus, pore fluids have been sampled from 8 Calypso cores in order to determine the concentration of dissolved elements. Five sites have been investigated: four of them are located along the main axis of a currently active lobe, the last one being located on a lobe disconnected from the chenals. The analyses of methane, major (Cl, SO4, Mg, Ca, K, Na) and minor (Sr, Ba, B, Li, Mn) elements have been carried out along with total alkalinity determination. The resulting profiles show a highly heterogeneous pore-fluid chemistry. Sulphate concentration near the seawater/sediment interface varies from 3 to 29 mM, indicating intense sulphate reduction. Surprisingly the lowest values are found at the site which is disconnected from the active lobe. The manganese cycle is well defined for all cores. The core recovered at the more distal lobe exhibits very peculiar pore-fluid profiles which are likely related to a geological event, most likely sediment slide and remobilization. References: Babonneau, N., Savoye, B., Cremer, M. & Klein, B., 2002. Morphology and architecture of the present canyon and channel system of the Zaire deep-sea fan, Mar. Pet. Geol., 19, 445-467. Savoye, B., Babonneau, N., Dennielou, B. & Bez, M., 2009. Geological overview of the Angola-Congo margin, the Congo deep-sea fan and its submarine valleys, Deep-Sea Res. Part II-Top. Stud. Oceanogr., 56, 2169-2182. Vangriesheim, A., Khripounoff, A. & Crassous, P., 2009. Turbidity events observed in situ along the Congo submarine channel, Deep-Sea Res. Part II-Top. Stud. Oceanogr., 56, 2208-2222. Zabel, M. & Schulz, H.D., 2001. Importance of submarine landslides for non-steady state conditions in pore water systems - lower Zaire (Congo) deep-sea fan, Mar. Geol., 176, 87-99.

Evaluation of a Prototype Surface Flow Bypass for Juvenile Salmon and Steelhead at the Powerhouse of Lower Granite Dam, Snake River, Washington, 1996-2000

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

Johnson, Gary E.; Anglea, Steven M.; Adams, Noah S.

2005-02-28

A surface flow bypass provides a route in the upper water column for naturally, surface-oriented juvenile salmonids to safely migrate through a hydroelectric dam. Surface flow bypasses were recommended in several regional salmon recovery plans as a means to increase passage survival of juvenile salmonids at Columbia and Snake River dams. A prototype surface flow bypass, called the SBC, was retrofit on Lower Granite Dam and evaluated from 1996 to 2000 using biotelemetry and hydroacoustic techniques. In terms of passage efficiency, the best SBC configurations were a surface skimmer (99 m3/s [3,500 cfs], three entrances 5 m wide, 5 mmore » deep and one entrance 5 m wide, 15 m deep) and a single chute (99 m3/s, one entrance 5 m wide, 8.5 m deep). They each passed 62 ? 3% (95% confidence interval) of the total juvenile fish population that entered the section of the dam with the SBC entrances (Turbine Units 4-5). Smooth entrance shape and concentrated surface flow characteristics of these configurations are worth pursuing in designs for future surface flow bypasses. In addition, a guidance wall in the Lower Granite Dam forebay diverted the following percentages of juvenile salmonids away from Turbine Units 1-3 toward other passage routes, including the SBC: run-at-large 79 ? 18%; hatchery steelhead 86%; wild steelhead 65%; and yearling chinook salmon 66%. When used in combination with spill or turbine intake screens, a surface flow bypass with a guidance wall can produce a high level (> 90% of total project passage) of non-turbine passage and provide operational flexibility to fisheries managers and dam operators responsible for enhancing juvenile salmonid survival.« less

Patterns of fish use and piscivore abundance within a reconnected saltmarsh impoundment in the northern Indian River Lagoon, Florida

USGS Publications Warehouse

Stevens, Philip W.; Montague, C.L.; Sulak, K.J.

2006-01-01

Nearly all saltmarshes in east-central, Florida were impounded for mosquito control during the 1960s. The majority of these marshes have since been reconnected to the estuary by culverts, providing an opportunity to effectively measure exchange of aquatic organisms. A multi-gear approach was used monthly to simultaneously estimate fish standing stock (cast net), fish exchange with the estuary (culvert traps), and piscivore abundance (gill nets and bird counts) to document patterns of fish use in a reconnected saltmarsh impoundment. Changes in saltmarsh fish abundance, and exchange of fish with the estuary reflected the seasonal pattern of marsh flooding in the northern Indian River Lagoon system. During a 6-month period of marsh flooding, resident fish had continuous access to the marsh surface. Large piscivorous fish regularly entered the impoundment via creeks and ditches to prey upon small resident fish, and piscivorous birds aggregated following major fish movements to the marsh surface or to deep habitats. As water levels receded in winter, saltmarsh fish concentrated into deep habitats and emigration to the estuary ensued (200% greater biomass left the impoundment than entered). Fish abundance and community structure along the estuary shoreline (although fringed with marsh vegetation) were not analogous to marsh creeks and ditches. Perimeter ditches provided deep-water habitat for large estuarine predators, and shallow creeks served as an alternative habitat for resident fish when the marsh surface was dry. Use of the impoundment as nursery by transients was limited to Mugil cephalus Linnaeus, but large juvenile and adult piscivorous fish used the impoundment for feeding. In conclusion, the saltmarsh impoundment was a feeding site for piscivorous fish and birds, and functioned as a net exporter of forage fish to adjacent estuarine waters. ?? Springer 2006.

Organic and inorganic carbon dynamics in a karst aquifer: Santa Fe River Sink-Rise system, north Florida, USA

NASA Astrophysics Data System (ADS)

Jin, Jin; Zimmerman, Andrew R.; Moore, Paul J.; Martin, Jonathan B.

2014-03-01

Spatiotemporal variations in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), major ions concentrations and other geochemical parameters including stable carbon isotopes of DIC (δ13CDIC), were measured in surface water and deep and shallow well water samples of the Santa Fe River Sink-Rise eogenetic karst system, north Florida, USA. Three end-member water sources were identified: one DOC-rich/DIC-poor/δ13CDIC-depleted, one DOC-poor/DIC-rich/δ13CDIC-enriched, and one enriched in major ions. Given their spatiotemporal distributions, they were presumed to represent soil water, upper aquifer groundwater, and deep aquifer water sources, respectively. Using assumed ratios of Na+, Cl, and SO42- for each end-member, a mixing model calculated the contribution of each water source to each sample. Then, chemical effects of biogeochemical reactions were calculated as the difference between those predicted by the mixing model and measured species concentrations. In general, carbonate mineral dissolution occurred throughout the Sink-Rise system, surface waters were net autotrophic and the subsurface was in metabolic balance, i.e., no net DOC or DIC production or consumption. However, there was evidence for chemolithoautotrophy, perhaps by hydrogen oxidizing microbes, at some deep aquifer sites. Mineralization of this autochthonous natural dissolved organic matter (NDOM) led to localized carbonate dissolution as did surface water-derived NDOM supplied to shallow well sites during the highest flow periods. This study demonstrates linkages between hydrology, abiotic and microbial processes and carbon dynamics and has important implications for groundwater quality, karst morphologic evolution, and hydrogeologic projects such as aquifer storage and recovery in karst systems.

Spatial Variability of the Background Diurnal Cycle of Deep Convection around the GoAmazon2014/5 Field Campaign Sites

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

Burleyson, Casey D.; Feng, Zhe; Hagos, Samson M.

The Amazon rainforest is one of a few regions of the world where continental tropical deep convection occurs. The Amazon’s isolation makes it challenging to observe, but also creates a unique natural laboratory to study anthropogenic impacts on clouds and precipitation in an otherwise pristine environment. Extensive measurements were made upwind and downwind of the large city of Manaus, Brazil during the Observations and Modeling of the Green Ocean Amazon 2014-2015 (GoAmazon2014/5) field campaign. In this study, 15 years of high-resolution satellite data are analyzed to examine the spatial and diurnal variability of convection occurring around the GoAmazon2014/5 sites. Interpretationmore » of anthropogenic differences between the upwind (T0) and downwind (T1-T3) sites is complicated by naturally-occurring spatial variability between the sites. During the rainy season, the inland propagation of the previous day’s sea-breeze front happens to be in phase with the background diurnal cycle near Manaus, but is out of phase elsewhere. Enhanced convergence between the river-breezes and the easterly trade winds generates up to 10% more frequent deep convection at the GoAmazon2014/5 sites east of the river (T0a, T0t/k, and T1) compared to the T3 site which was located near the western bank. In general, the annual and diurnal cycles during 2014 were representative of the 2000-2013 distributions. The only exceptions were in March when the monthly mean rainrate was above the 95th percentile and September when both rain frequency and intensity were suppressed. The natural spatial variability must be accounted for before interpreting anthropogenically-induced differences among the GoAmazon2014/5 sites.« less

Hydrogeologic Framework and Occurrence and Movement of Ground Water in the Upper Humboldt River Basin, Northeastern Nevada

USGS Publications Warehouse

Plume, Russell W.

2009-01-01

The upper Humboldt River basin encompasses 4,364 square miles in northeastern Nevada, and it comprises the headwaters area of the Humboldt River. Nearly all flow of the river originates in this area. The upper Humboldt River basin consists of several structural basins, in places greater than 5,000 feet deep, in which basin-fill deposits of Tertiary and Quaternary age and volcanic rocks of Tertiary age have accumulated. The bedrock of each structural basin and adjacent mountains is composed of carbonate and clastic sedimentary rocks of Paleozoic age and crystalline rocks of Paleozoic, Mesozoic and Cenozoic age. The permeability of bedrock generally is very low except for carbonate rocks, which can be very permeable where circulating ground water has widened fractures through geologic time. The principal aquifers in the upper Humboldt River basin occur within the water-bearing strata of the extensive older basin-fill deposits and the thinner, younger basin-fill deposits that underlie stream flood plains. Ground water in these aquifers moves from recharge areas along mountain fronts to discharge areas along stream flood plains, the largest of which is the Humboldt River flood plain. The river gains flow from ground-water seepage to its channel from a few miles west of Wells, Nevada, to the west boundary of the study area. Water levels in the upper Humboldt River basin fluctuate annually in response to the spring snowmelt and to the distribution of streamflow diverted for irrigation of crops and meadows. Water levels also have responded to extended periods (several years) of above or below average precipitation. As a result of infiltration from the South Fork Reservoir during the past 20 years, ground-water levels in basin-fill deposits have risen over an area as much as one mile beyond the reservoir and possibly even farther away in Paleozoic bedrock.

Hypoaigic influences on groundwater flux to a seasonally saline river

NASA Astrophysics Data System (ADS)

Trefry, M. G.; Svensson, T. J. A.; Davis, G. B.

2007-03-01

SummaryHypoaigic zones are aquifer volumes close to and beneath the shores of saline surface water bodies, and are characterized by the presence of time-dependent natural convection and chemical stratification. When transient and cyclic processes are involved there is significant potential for complex flow and reaction in the near-shore aquifer, presenting a unique challenge to pollutant risk assessment methodologies. This work considers the nature of some hypoaigic processes generated by the seasonally saline Canning River of Western Australia near a site contaminated by petroleum hydrocarbons. A dissolved hydrocarbon plume migrates within the shallow superficial aquifer to the nearby bank of the Canning River. Beneath the river bank a zone of complex fluid mixing is established by seasonal and tidal influences. Understanding this complexity and the subsequent ramifications for local biogeochemical conditions is critical to inferring the potential for degradation of advecting contaminants. A range of modelling approaches throws light on the overall topographic controls of discharge to the river, on the saline convection processes operating under the river bank, on the potential for fluid mixing, and on the various important time scales in the system. Saline distributions simulated within the aquifer hypoaigic zone are in at least qualitative agreement with previous field measurements at the site and are strongly affected by seasonal influences. Groundwater seepage velocities at the shoreline are found to be positively correlated with river salinity. Calculations of fluid age distributions throughout the system show sensitivity to dispersivity values; however, maximum fluid ages under the river appear to be diffusion limited to a few decades. The saline convection cell in the aquifer defines a zone of strong dispersive dilution of aged (many decades) deep aquifer fluids with relatively young (several months) riverine fluids. Seasonal recharge and river salinity cycles induce regular perturbations to the convection cell, yielding intra-annual variations of 50% in seepage velocity and almost 30% in wedge penetration distance at the plume location.

Early life history stages of Gulf sturgeon in the Suwannee River, Florida

USGS Publications Warehouse

Sulak, K.J.; Clugston, James P.

1998-01-01

Egg sampling confirmed that Suwannee River Gulf sturgeon Acipenser oxyrinchus desotoi, a subspecies of Atlantic sturgeon A. o. oxyrinchus use the same spawning site at river kilometer (rkm) 215 from the month of the river each year. Forty-nine eggs were recorded in 1995, and 368 were recorded in 1996. Spawning began 4-7 d after the March new moon in both years and lasted 10-11 d; in 1996, a second 10-d spawning round began on the April new moon. Developmental synchrony among eggs recovered suggested several discrete spawning events in both years. Total eggs deposited for three 1996 sampling days was estimated as 405,600-711,000/d, approximating the fecundity range of a large female Gulf sturgeon. Eggs were found only in the southern half of the river, an area with surface currents of 0.5-1.5 m/s and numerous eddies producing reverse bottom currents of 0.1-0.5 m/s. Egg substrate consisted of bedrock limestone thinly overlain by fine sand and densely distributed elliptical gravel 2-10 cm in diameter. Eggs were found predominantly in depths of 2-4 m at water temperatures of 17-21??C, conductivities of 50-100 ??S, and dissolved oxygen levels exceeding 5.0 mg/L. The Cody Scarp, 15 rkm above the spawning ground, may mark the upstream limit of spawning areas in the river. Three 2-4-month-old riverine juveniles (82-115 mm total length, TL) collected are the smallest yet captured from any river. Data for 18 riverine age-0 juveniles (to 350 mm TL) suggest that this stage lasts 6-10 months, terminating with migration of fish to the river mouth in January-February. Less than 2% of 461 juveniles captured at the estuarine river mouth (1990-1993) were under 350 mm TL. Riverine age-0 fish were collected over long shallow stretches (typically <4 m deep) of relatively barren sand (rkm 12-238).

Effects of groundwater abstraction on two keystone tree species in an arid savanna national park.

PubMed

Shadwell, Eleanor; February, Edmund

2017-01-01

In arid systems with no surface water, deep boreholes in ephemeral river beds provide for humans and animals. With continually increasing infrastructure development for tourism in arid wildlife parks such as the Kgalagadi Transfrontier Park in southern Africa, we ask what effects increased abstraction may have on large trees. Large trees in arid savannas perform essential ecosystem services by providing food, shade, nesting sites and increased nutrients for many other plant and animal species and for this are regarded as keystone species. We determine seasonal fluctuations in the water table while also determining the water source for the dominant large tree species in the Auob and Nossob rivers in the Park. We also determine the extent to which these trees are physiologically stressed using leaf δ 13 C, xylem pressure potentials, specific leaf area and an estimate of canopy death. We do this both upstream and downstream of a low water use borehole in the Auob River and a high water use borehole in the Nossob River. Our results show that the trees are indeed using deep groundwater in the wet season and that this is the same water used by people. In the dry season, trees in the Auob downstream of the active borehole become detached from the aquifer and use more isotopically enriched soil water. In the Nossob in the dry season, all trees use isotopically enriched soil water, and downstream of the active borehole use stomatal regulation to maintain leaf water potentials. These results suggest that trees in the more heavily utilised Nossob are under more water stress than those trees in the Auob but that trees in both rivers demonstrate physiological adaptation to the changes in available water with smaller heavier leaves, no significant canopy dieback and in the dry season in the Nossob stomatal regulation of leaf water potentials. An increase in abstraction of groundwater particularly at the Nossob borehole may cause an additional draw down of the water table adding to the physiological stress demonstrated in our study. The managers of the Kgalagadi Transfrontier Park have a mandate that includes biodiversity conservation. To fulfil this mandate, upper and lower thresholds for groundwater abstraction that allow for an adequate ecological reserve have to be determined.

Effects of groundwater abstraction on two keystone tree species in an arid savanna national park

PubMed Central

2017-01-01

Background In arid systems with no surface water, deep boreholes in ephemeral river beds provide for humans and animals. With continually increasing infrastructure development for tourism in arid wildlife parks such as the Kgalagadi Transfrontier Park in southern Africa, we ask what effects increased abstraction may have on large trees. Large trees in arid savannas perform essential ecosystem services by providing food, shade, nesting sites and increased nutrients for many other plant and animal species and for this are regarded as keystone species. Methods We determine seasonal fluctuations in the water table while also determining the water source for the dominant large tree species in the Auob and Nossob rivers in the Park. We also determine the extent to which these trees are physiologically stressed using leaf δ13C, xylem pressure potentials, specific leaf area and an estimate of canopy death. We do this both upstream and downstream of a low water use borehole in the Auob River and a high water use borehole in the Nossob River. Results Our results show that the trees are indeed using deep groundwater in the wet season and that this is the same water used by people. In the dry season, trees in the Auob downstream of the active borehole become detached from the aquifer and use more isotopically enriched soil water. In the Nossob in the dry season, all trees use isotopically enriched soil water, and downstream of the active borehole use stomatal regulation to maintain leaf water potentials. These results suggest that trees in the more heavily utilised Nossob are under more water stress than those trees in the Auob but that trees in both rivers demonstrate physiological adaptation to the changes in available water with smaller heavier leaves, no significant canopy dieback and in the dry season in the Nossob stomatal regulation of leaf water potentials. Discussion An increase in abstraction of groundwater particularly at the Nossob borehole may cause an additional draw down of the water table adding to the physiological stress demonstrated in our study. The managers of the Kgalagadi Transfrontier Park have a mandate that includes biodiversity conservation. To fulfil this mandate, upper and lower thresholds for groundwater abstraction that allow for an adequate ecological reserve have to be determined. PMID:28149693

Effect of Interactive River Routing on North Atlantic Overturning in a Simulation of the last Deglaciation

NASA Astrophysics Data System (ADS)

Mikolajewicz, Uwe; Ziemen, Florian; Kapsch, Marie; Meccia, Virna

2017-04-01

One of the major challenges in climate modeling is the simulation of glacial-interglacial transitions. A few models of intermediate complexity have been successful in simulating the last termination. Complex atmosphere-ocean general circulation models (AOGCMs) with prescribed ice sheets are able to yield realistic climate changes. Here we present results from our first attempt to simulate a substantial part of the last glacial cycle with an AOGCM coupled interactively with a state-of-the-art ice sheet model. The ECHAM5/MPIOM AOGCM is interactively coupled to the dynamical ice sheet model PISM and the dynamical vegetation model LPJ. The model is integrated from the late Glacial into the Holocene using insolation and greenhouse gas concentrations as transient forcing. To make the long simulations feasible, the atmosphere is accelerated by a factor of 10 relative to the other components using a periodical-synchronous coupling technique. The land sea mask remains fixed at the LGM state. River routing and surface elevation are calculated interactively. A mini-ensemble with different initial conditions is performed. Additionally, one fully synchronously simulation, without acceleration in the atmosphere, is run. In all simulations the northern hemisphere deglaciation starts between 18 and 17 kyr BP, consistent with the onset of global warming. The model produces Heinrich event like variability. These rapid ice discharge events have a strong impact on the North Atlantic meridional overturning circulation (NAMOC). The interactive river routing has a strong impact on the simulated NAMOC during the deglaciation. The retreat of the Laurentide Ice Sheet together with the depressed topography due to the former ice load leads to a redirection of the river routes.. In particular, the discharge route for runoff from the melting southwestern Laurentide shifts from the Gulf of Mexico to the Arctic. The consequence is a rapid reduction/suppression of the North Atlantic deep water (NADW) formation. When the Laurentide Ice Sheet retreats from the Hudson Strait, this becomes the new drainage route. Hence, fresh water is released into the Labrador Sea and is less effective in suppressing the deep water formation in the North Atlantic. As a consequence, the NADW formation recovers within a few decades. Our results show the potential importance of interactive river routing for rapid changes in NAMOC strength during the deglaciation.

Preliminary Assessment of Landslides Along the Florida River Downstream from Lemon Reservoir, La Plata County, Colorado

USGS Publications Warehouse

Schulz, William H.; Coe, Jeffrey A.; Ellis, William L.; Kibler, John D.

2006-01-01

Nearly two-dozen shallow landslides were active during spring 2005 on a hillside located along the east side of the Florida River about one kilometer downstream from Lemon Reservoir in La Plata County, southwestern Colorado. Landslides on the hillside directly threaten human safety, residential structures, a county roadway, utilities, and the Florida River, and indirectly threaten downstream areas and Lemon Dam. Most of the area where the landslides occurred was burned during the 2002 Missionary Ridge wildfire. We performed geologic mapping, subsurface exploration and sampling, radiocarbon dating, and shallow ground-water and ground-displacement monitoring to assess landslide activity. Active landslides during spring 2005 were as large as 35,000 m3 and confined to colluvium. Debris flows were mobilized from most of the landslides, were as large as 1,500 m3, and traveled as far as 250 m. Landslide activity was triggered by elevated ground-water pressures within the colluvium caused by infiltration of snowmelt. Landslide activity ceased as ground-water pressures dropped during the summer. Shallow landslides on the hillside appear to be much more likely following the Missionary Ridge fire because of the loss of tree root strength and evapotranspiration. We used monitoring data and observations to develop preliminary, approximate rainfall/snowmelt thresholds above which shallow landslide activity can be expected. Landslides triggered during spring 2005 occurred within a 1.97 x 107 m3 older landslide that extends, on average, about 40 m into bedrock. The south end of this older landslide appears to have experienced deep secondary landsliding. Radiocarbon dating of sediments at the head of the older landslide suggests that the landslide was active about 1,424-1,696 years ago. A relatively widespread wildfire may have preceded the older landslide, and the landslide may have occurred during a wetter time. The wetter climate and effects of the wildfire would likely have resulted in increased ground-water pressures, which may have triggered the older landslide. This landslide appears to have crossed the valley floor and been subsequently eroded from this area. We found no evidence that landslide debris across the valley floor formed an impoundment of the Florida River, although it is very likely. Erosion of buttressing landslide debris from the valley floor and the lower strength of the landslide basal shear zone relative to pre-slide strength created less stable conditions than were present prior to occurrence of the landslide. However, deep ground-water conditions largely control the stability of the slope and are unknown here; hence, the potential for future deep landsliding is unknown. Additional investigation could be undertaken to further characterize landslide hazards in the area. This investigation could include episodic surveying of monuments we installed across the older landslide, obtaining detailed topographic data and aerial photography, mapping landslide debris and lacustrine deposits related to the potential former landslide dam, mapping secondary landslides, obtaining additional ages of landslide activity, constructing deep boreholes and ground-water monitoring wells, laboratory testing of soil and rock strength and hydraulic properties, and ground-water and slope-stability modeling.

Global Analysis of River Planform Change using the Google Earth Engine

NASA Astrophysics Data System (ADS)

Bryk, A.; Dietrich, W. E.; Gorelick, N.; Sargent, R.; Braudrick, C. A.

2014-12-01

Geomorphologists have historically tracked river dynamics using a combination of maps, aerial photographs, and the stratigraphic record. Although stratigraphic records can extend into deep time, maps and aerial photographs often confine our record of change to sparse measurements over the last ~80 years and in some cases much less time. For the first time Google's Earth Engine (GEE) cloud based platform allows researchers the means to analyze quantitatively the pattern and pace of river channel change over the last 30 years with high temporal resolution across the entire planet. The GEE provides an application programing interface (API) that enables quantitative analysis of various data sets including the entire Landsat L1T archive. This allows change detection for channels wider than about 150 m over 30 years of successive, georeferenced imagery. Qualitatively, it becomes immediately evident that the pace of channel morphodynamics for similar planforms varies by orders of magnitude across the planet and downstream along individual rivers. To quantify these rates of change and to explore their controls we have developed methods for differentiating channels from floodplain along large alluvial rivers. We introduce a new metric of morphodynamics: the ratio of eroded area to channel area per unit time, referred to as "M". We also keep track of depositional areas resulting from channel shifting. To date our quantitative analysis has focused on rivers in the Andean foreland. Our analysis shows channel bank erosion rates, M, varies by orders of magnitude for these rivers, from 0 to ~0.25 yr-1, yet these rivers have essentially identical curvature and sinuosity and are visually indistinguishable. By tracking both bank paths in time, we find that, for some meandering rivers, a significant fraction of new floodplain is produced through outer-bank accretion rather than point bar deposition. This process is perhaps more important in generating floodplain stratigraphy than previously recognized. These initial findings indicate a new set of quantitative observations will emerge to further test and advance morphodynamic theory. The Google Earth Engine offers the opportunity to explore river morphodynamics on an unprecedented scale and provides a powerful tool for addressing fundamental questions in river morphodynamics.

Sedimentology and Palynostratigraphy of a Pliocene-Pleistocene (Piacenzian to Gelasian) deposit in the lower Negro River: Implications for the establishment of large rivers in Central Amazonia

NASA Astrophysics Data System (ADS)

Soares, Emílio Alberto Amaral; D'Apolito, Carlos; Jaramillo, Carlos; Harrington, Guy; Caputo, Mario Vicente; Barbosa, Rogério Oliveira; Bonora dos Santos, Eneas; Dino, Rodolfo; Gonçalves, Alexandra Dias

2017-11-01

The Amazonas fluvial system originates in the Andes and runs ca. 6700 km to the Atlantic Ocean, having as the main affluent the Negro River (second largest in water volume). The Amazonas transcontinental system has been dated to the late Miocene, but the timing of origin and evolutionary processes of its tributaries are still poorly understood. Negro River alluvial deposits have been dated to the middle to late Pleistocene. Recently, we studied a number of boreholes drilled for the building of a bridge at the lower course of the Negro River. A thin (centimetric) sedimentary deposit was found, laterally continuous for about 1800 m, unconformably overlaying middle Miocene strata and unconformably overlain by younger Quaternary deposits. This deposit consists predominantly of brownish-gray sandstones cemented by siderite and with subordinate mudstone and conglomerate beds. Palynological, granulometric, textural and mineralogical data suggest that the initial Negro River aggradation took place in the deep incised valley under anoxic conditions and subsequently along the floodplain, with efficient transport of mixed origin particles (Andean and Amazonic). Angiosperm leaves, wood and pollen are indicative of a tropical continental palaeoenvironment. A well preserved palynoflora that includes Alnipollenites verus, Grimsdalea magnaclavata and Paleosantalaceaepites cingulatus suggests a late Pliocene to early Pleistocene (Piacenzian to Gelasian) age for this unit, which was an age yet unrecorded in the Amazon Basin. These results indicate that by the late Pliocene-early Pleistocene, large scale river activity was occurring in Central Amazonia linking this region with the Andean headwaters, and therefore incompatible with Central Amazonia barriers like the Purus arch.

High-precision U-Pb geochronology in the Minnesota River Valley subprovince and its bearing on the Neoarchean to Paleoproterozoic evolution of the southern Superior Province

USGS Publications Warehouse

Schmitz, M.D.; Bowring, S.A.; Southwick, D.L.; Boerboom, Terrence; Wirth, K.R.

2006-01-01

High-precision U-Pb ages have been obtained for high-grade gneisses, late-kinematic to postkinematic granitic plutons, and a crosscutting mafic dike of the Archean Minnesota River Valley tectonic subprovince, at the southern ramparts of the Superior craton of North America. The antiquity of the Minnesota River Valley terranes is confirmed by a high-precision U-Pb zircon age of 3422 ?? 2 Ma for a tonalitic phase of the Morton Gneiss. Voluminous, late-kinematic monzogranites of the Benson (Ortonville granite) and Morton (Sacred Heart granite) blocks yield identical crystallization ages of 2603 ?? 1 Ma, illustrating the synchrony and rapidity of deep crustal melting and plutonism throughout the Minnesota River Valley terranes. Postkinematic, 2591 ?? 2 Ma syenogranites and aplitic dikes in both blocks effectively constrain the final penetrative deformation of the Minnesota River Valley subprovince. Monazite growth from 2609 to 2595 Ma in granulitic paragneisses of the Benson and Montevideo blocks is interpreted to record prograde to peak granulite facies metamorphic conditions associated with crustal thickening and magmatism. Neoarchean metamorphism and plutonism are interpreted to record the timing of collisional accretion and terminal suturing of the Mesoarchean continental Minnesota River Valley terranes to the southern margin of the Superior Province, along the western Great Lakes tectonic zone. Subsequent Paleoproterozoic rifting of this margin is recorded by voluminous basaltic dike intrusion, expressed in the Minnesota River Valley by major WNW-trending tholeiitic diabase dikes dated at 2067 ?? 1 Ma, only slightly younger than the structurally and geochemically similar 2077 ?? 4 Ma Fort Frances (Kenora-Kabetogama) dike swarm of northern Minnesota and adjoining Canada. ?? 2006 Geological Society of America.

Surveying Cross Sections of the Kootenai River Between Libby Dam, Montana, and Kootenay Lake, British Columbia, Canada

USGS Publications Warehouse

Barton, Gary J.; Moran, Edward H.; Berenbrock, Charles

2004-01-01

The declining population of Kootenai River white sturgeon, which was listed as an Endangered Species in 1994, has prompted a recovery team to assess the feasibility of various habitat enhancement scenarios to reestablish white sturgeon populations. As the first phase in this assessment, the U.S. Geological Survey collected stream channel cross-section and longitudinal data during 2002—03 at about 400 locations along the Kootenai River from Libby Dam near Libby, Montana, to where the river empties into Kootenay Lake near Creston, British Columbia, Canada. Survey control stations with a horizontal and vertical accuracy of less than 0.1 foot were established using a global positioning system (GPS) prior to collection of stream channel cross-section data along the Kootenai River. A total of 245 cross sections were surveyed. Six cross sections upstream from Kootenai Falls were surveyed using a total station where the river was too shallow or dangerous to navigate by vessel. The remaining 239 cross sections were surveyed by interfacing real-time GPS equipment with an echo sounder to obtain bathymetric data and with a laser range- finder to obtain streambank data. These data were merged, straightened, ordered, and reduced in size to be useful. Spacing between these cross sections ranged from about 600 feet in the valley flat near Deep Creek and Shorty Island and near bridges to as much as several miles in other areas. These stream channel cross sections will provide information that can be used to develop hydraulic flow models of the Kootenai River from Libby Dam, Montana, to Queens Bay on Kootenay Lake in British Columbia, Canada.

Analysis of the Tanana River Basin using LANDSAT data

NASA Technical Reports Server (NTRS)

Morrissey, L. A.; Ambrosia, V. G.; Carson-Henry, C.

1981-01-01

Digital image classification techniques were used to classify land cover/resource information in the Tanana River Basin of Alaska. Portions of four scenes of LANDSAT digital data were analyzed using computer systems at Ames Research Center in an unsupervised approach to derive cluster statistics. The spectral classes were identified using the IDIMS display and color infrared photography. Classification errors were corrected using stratification procedures. The classification scheme resulted in the following eleven categories; sedimented/shallow water, clear/deep water, coniferous forest, mixed forest, deciduous forest, shrub and grass, bog, alpine tundra, barrens, snow and ice, and cultural features. Color coded maps and acreage summaries of the major land cover categories were generated for selected USGS quadrangles (1:250,000) which lie within the drainage basin. The project was completed within six months.

Potential for Natural Gas Storage in Deep Basalt Formations at Canoe Ridge, Washington State: A Hydrogeologic Assessment

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

Reidel, Steve P.; Spane, Frank A.; Johnson, Vernon G.

2005-09-24

Between 1999 and 2002, Pacific Gas Transmission Company (PGT) (now TransCanada Pipeline Company) and AVISTA Corporation, together with technical support provided by the Pacific Northwest National Laboratory and the U.S. Department of Energy (DOE) examined the feasibility of developing a subsurface, natural gas-storage facility in deep, underlying Columbia River basalt in south-central Washington state. As part of this project, the 100 Circles #1 well was drilled and characterized in addition to surface studies. This report provides data and interpretations of the geology and hydrology collected specific to the Canoe Ridge site as part of the U.S. DOE funding to themore » Pacific Northwest National Laboratory in support of this project.« less

The role of extreme floods in estuary-coastal behaviour: contrasts between river- and tide-dominated microtidal estuaries

NASA Astrophysics Data System (ADS)

Cooper, J. A. G.

2002-06-01

Contrasting modes of sedimentation and facies arrangement in tide- and river-dominated microtidal estuaries arise from the degree to which river or tidal discharge and sediment supply influences an estuary. A distinct facies gradation exists in tide-dominated systems from sandy, barrier/tidal delta-associated environments at the coast through deep mud-dominated middle reaches to fluvial sediment in the upper reaches. In river-dominated systems, fluvial sediment extends to the barrier and flood-tidal deltas are poorly developed or absent from the estuary. A number of independent observations during extreme floods on the South African coast indicate that these types of estuary respond differently to extreme river floods and that the mode of response corresponds to estuary type. Tide-dominated systems exhibit preferential erosion of noncohesive barrier and tidal delta sediments during river floods while the middle reaches remain little modified. River-dominated systems experience consistent erosion throughout their channel length during extreme floods. The increased cohesion of riverine sediments and stabilisation of bars by vegetation in river-dominated channels means that higher magnitude floods are necessary to effect significant morphological change. Barrier erosion, including the tidal delta, results in deposition of an ephemeral delta composed almost entirely of sands from these deposits in tide-dominated estuaries. In river-dominated systems, eroded channel sediments and material from the river catchment may augment barrier sediments in the ephemeral delta deposit. Post-flood, wave-reworking of ephemeral delta sediments acts to restore barriers to pre-flood morphology within a few years; however, in river-dominated systems, the additional sediment volume may produce significant coastal progradation that requires several years or decades to redistribute. These different modes of flood response mediated by the nature of the estuary have implications for coastal behaviour at the time scale of months to several decades. Estuary-coastal behaviour at river-dominated estuaries may be influenced for several decades by post-flood morphological adjustment. Tide-dominated estuaries, however, respond more rapidly in reworking flood-eroded sediment and are typically fully adjusted to modal wave and tidal conditions within a few months to a few years. In addition, the facies arrangement within the two estuary types renders tide-dominated estuaries more responsive to minor floods, while river-dominated estuaries, by virtue of more cohesive channel sediments, require greater discharges to effect significant morphological change.

Analysis of water use strategies of the desert riparian forest plant community in inland rivers of two arid regions in northwestern China

NASA Astrophysics Data System (ADS)

Chen, Y. N.; Li, W. H.; Zhou, H. H.; Chen, Y. P.; Hao, X. M.; Fu, A. H.; Ma, J. X.

2014-10-01

Studies of the water use of the desert riparian forest plant community in arid regions and analyses of the response and adaptive strategies of plants to environmental stress are of great significance to the formulation of effective ecological conservation and restoration strategies. Taking two inland rivers in the arid regions of northwestern China, downstream of the Tarim River and Heihe River Basin as the research target regions, this paper explored the stem water potential, sap flow, root hydraulic lift, and characteristics of plant water sources of the major constructive species in the desert riparian forest, Populus euphratica and Tamarix ramosissima. Specifically, this was accomplished by combining the monitoring of field physiological and ecological indicators, and the analysis of laboratory tests. Then, the water use differences of species in different ecological environments and their ecological significance were analyzed. This study indicated that: (1) in terms of water sources, Populus euphratica and Tamarix ramosissima mainly used deep subsoil water and underground water, but the plant root system in the downstream of the Tarim River was more diversified than that in the downstream of the Heihe River in water absorption, (2) in terms of water distribution, Populus euphratica root possessed hydraulic lift capacity, but Populus euphratica root in the downstream of the Tarim River presented stronger hydraulic lift capacity and more significant ecological effect of water redistribution, (3) in terms of water transport, the plants in the downstream of the Heihe River can adapt to the environment through the current limiting of branch xylem, while plants in the downstream of the Tarim River substantially increased the survival probability of the whole plant by sacrificing weak branches and improving the water acquisition capacity of dominant branches; and (4) in terms of water dissipation, the water use and consumption of Populus euphratica at night exhibited no significant difference, but the water use and consumption of Populus euphratica in the downstream of the Tarim River in the day was significantly higher than that in the downstream of the Heihe River, and the essential reason for this is the groundwater depth. The ecology in the downstream of the Heihe River has been in balance in the maintenance and development stage, while desert riparian forest plants in the downstream of the Tarim River are still in severe arid stress.

Detect groundwater flowing from riverbed using a drone

NASA Astrophysics Data System (ADS)

Kato, Kenji; Takemon, Yasuhiro

2017-04-01

Estimate the direct flow of groundwater to river is an important step in understanding of hydrodynamics in river system. Function of groundwater in river system does not limit to the mass of water. Continuous supply with thermally stable water from riverbed produces a space with unique condition, which provides various functions for organisms inhabiting in river as a shelter avoiding large shift of temperature, or to maintain productivity for small scale ecosystem by supplying nutrient rich groundwater if it gushes out from the riverbed in a deep pool of river. This may contribute to biodiversity of river system. Such function of groundwater is more significant for rivers run in island and in mountain zone. To evaluate the function of groundwater flowing from riverbed we first try to find such site by using a drone equipped with a sensitive thermo-camera to detect water surface temperature. In the examined area temperature of the groundwater doesn't change much throughout a year at around 15 to 16 °C, while surface temperature of the examined river fluctuates from below 10 °C to over 25 °C throughout seasons. By using this difference in temperature between groundwater and river water we tried to find site where groundwater comes out from the riverbed. Obviously winter when surface temperature becomes below 10 °C is an appropriate season to find groundwater as it comes up to the surface of river with depth ranging from 1 to 3 m. Trial flight surveys of drone were conducted in Kano-river in Izu Peninsula located at southern foot of Mt. Fuji in central Japan. Employed drone was Inspire1 (DJI, China) equipped with a Thermal camera (Zenmuse XT ZXTA 19 FP, FLIR, USA) and operated by Kazuhide Juta (KELEK Co. Ltd., Japan) and Mitsuhiro Komiya (TAM.Co.,LTD). In contrast to the former cases with employing airplane for taking aerial photograph, drone takes photo while flying at a low-altitude. When it flies at 40m above the water surface of river, resolution is at an order of "cm". We show how we found the possible sites where groundwater flowing from the riverbed by the photo and video. Surveys were conducted through the assistance with Numazu Office of River and National Highway Chubu Regional Development Bureau, Ministry of Land, Infrastructure, Transport and Tourism Japan, Japan Riverfront Research Center and Shizuoka University.

Spectrally based bathymetric mapping of a dynamic, sand‐bedded channel: Niobrara River, Nebraska, USA

USGS Publications Warehouse

Dilbone, Elizabeth; Legleiter, Carl; Alexander, Jason S.; McElroy, Brandon

2018-01-01

Methods for spectrally based mapping of river bathymetry have been developed and tested in clear‐flowing, gravel‐bed channels, with limited application to turbid, sand‐bed rivers. This study used hyperspectral images and field surveys from the dynamic, sandy Niobrara River to evaluate three depth retrieval methods. The first regression‐based approach, optimal band ratio analysis (OBRA), paired in situ depth measurements with image pixel values to estimate depth. The second approach used ground‐based field spectra to calibrate an OBRA relationship. The third technique, image‐to‐depth quantile transformation (IDQT), estimated depth by linking the cumulative distribution function (CDF) of depth to the CDF of an image‐derived variable. OBRA yielded the lowest depth retrieval mean error (0.005 m) and highest observed versus predicted R2 (0.817). Although misalignment between field and image data did not compromise the performance of OBRA in this study, poor georeferencing could limit regression‐based approaches such as OBRA in dynamic, sand‐bedded rivers. Field spectroscopy‐based depth maps exhibited a mean error with a slight shallow bias (0.068 m) but provided reliable estimates for most of the study reach. IDQT had a strong deep bias but provided informative relative depth maps. Overprediction of depth by IDQT highlights the need for an unbiased sampling strategy to define the depth CDF. Although each of the techniques we tested demonstrated potential to provide accurate depth estimates in sand‐bed rivers, each method also was subject to certain constraints and limitations.

Tritium in the western Mediterranean Sea during 1981 Phycemed cruise

NASA Astrophysics Data System (ADS)

Andrie, Chantal; Merlivat, Liliane

1988-02-01

We report on simultaneous hydrological and tritium data taken in the western Mediterranean Sea during April 1981 and which implement our knowledge of the spatial and temporal variability of the convection process occurring in the Northern Basin (Gulf of Lion, Ligurian Sea). The renewal time of the deep waters in the Medoc area is calculated to be 11 ± 2 years using a box-model assymption. An important local phenomenon of "cascading" off the Ebro River near the Spanish coast is, noticeable by the use of tritium data. In the Sardinia Straits area tritium data indicate very active mixing between 100 and 500 m depth. The tritium subsurface maxima in Sardinia Straits suggests the influence of not only the Levantine Intermediate Water (LIW) but also an important shallower component. In waters deeper than 500m, an active mixing occurs between the deep water and the LIW via an intermediate water mass from the Tyrrhenian Sea by "salt-fingering". Assuming a two end-member mixing. We determine the deep tritium content in the Sardinia Channel to be 1.8 TU. For comparison, the deep tritium content of the Northern Basin is equal to 1.3 TU. Tritium data relative to the Alboran Sea show that a layer of high tritium content persists all along its path from Sardifia to Gibraltar on a density surface shallower than the intermediate water. The homogeneity of the deep tritium concentrations between 1200 m depth and the bottom corroborate the upward "pumping" and westward circulation of deep waters along the continental slope of the North African Shelf. From the data measured in the Sardinia Straits and in the Alboran Sea, and upper limit of the deep advection rate of the order of 0.5 cm s-1 is estimated.

Allogenic and Autogenic Signals in the Detrital Zircon U-Pb Record of the Deep-Sea Bengal Fan

NASA Astrophysics Data System (ADS)

Blum, M. D.; Rogers, K. G.; Gleason, J. D.; Najman, Y.

2017-12-01

The Himalayan-sourced Ganges-Brahmaputra river system and the deep-sea Bengal Fan represent Earth's largest sediment-dispersal system. This presentation summarizes a new detrital zircon U-Pb (DZ) provenance record from the Bengal Fan from cores collected during IODP Expedition 354, with coring sites located 1350 km downdip from the shelf margin. Each of our 15 samples were collected from medium- to fine-grained turbidite sand and, based on shipboard biostratigraphic analyses, our samples are late Miocene to late Pleistocene in age. Each sample was analyzed by LA-ICPMS at the Arizona Laserchron facility, with an average of n=270 concordant U-Pb ages per sample. Our goals are to use these data to evaluate the influence of allogenic controls vs. autogenic processes on signal propagation from source-to-sink. At the first order, large-scale sediment transfer to the Bengal Fan clearly records the strong tectonic and climatic forcing associated with the Himalayas and Ganges-Brahmaputra system: after up to 2500 km of river transport, and 1350 km of transport in turbidity currents, the DZ record faithfully represents Himalayan source terrains. The sand-rich turbidite part of the record is nevertheless biased towards glacial periods when rivers extended across the shelf in response to climate-forced sea-level fall, and discharged directly to slope canyons. However, only part of the Bengal Fan DZ record represents either the Ganges or the Brahmaputra, with most samples representing varying degrees of mixing of sediments from the two systems: this mixing, or the lack thereof, represents the signal of autogenic avulsions on the delta plain that result in the two river systems delivering sediment separately to the shelf margin, or together as they do today. Within the allogenic framework established by tectonic processes, the climatic system, and global climate-forced sea-level change, the DZ U-Pb record of sediment mixing or the lack thereof provides a fingerprint of autogenic avulsions on signal transfer from source-to-sink in the world's largest sediment-dispersal system.

Management decision of optimal recharge water in groundwater artificial recharge conditions- A case study in an artificial recharge test site

NASA Astrophysics Data System (ADS)

He, H. Y.; Shi, X. F.; Zhu, W.; Wang, C. Q.; Ma, H. W.; Zhang, W. J.

2017-11-01

The city conducted groundwater artificial recharge test which was taken a typical site as an example, and the purpose is to prevent and control land subsidence, increase the amount of groundwater resources. To protect groundwater environmental quality and safety, the city chose tap water as recharge water, however, the high cost makes it not conducive to the optimal allocation of water resources and not suitable to popularize widely. To solve this, the city selects two major surface water of River A and B as the proposed recharge water, to explore its feasibility. According to a comprehensive analysis of the cost of recharge, the distance of the water transport, the quality of recharge water and others. Entropy weight Fuzzy Comprehensive Evaluation Method is used to prefer tap water and water of River A and B. Evaluation results show that water of River B is the optimal recharge water, if used; recharge cost will be from 0.4724/m3 to 0.3696/m3. Using Entropy weight Fuzzy Comprehensive Evaluation Method to confirm water of River B as optimal water is scientific and reasonable. The optimal water management decisions can provide technical support for the city to carry out overall groundwater artificial recharge engineering in deep aquifer.

The Miocene Roof Mapping Using Microtremor Recording and Electrical Survey Method in Blida City, Algeria

NASA Astrophysics Data System (ADS)

Bouchelouh, Assia; Bensalem, Rabah; Zaourar, Naima; Machane, Djamel; Moulouel, Hakim; Oubaiche, El Hadi

2018-01-01

Bedrock depths in the Mitidja basin in general and in the Blida region in particular are still poorly known despite, the existence of some relatively deep hydraulic boreholes that intersect only superficial alluvial formations. To assess the seismic risk of Blida town, knowledge of soil amplification requires the thickness and properties of sedimentary formations that cover the substratum. For the purposes of our study, the thicknesses obtained by the vertical electric soundings, carried out in the hydrogeological study of the basin, were combined with horizontal-to-vertical spectral ratio (HVSR) microtremor recordings. This combination made it possible to determine an empirical relationship between frequency and thickness specific to the Blida site area, which enabled the roof of the Miocene to be mapped and shows slight undulations with directions compatible with the tectonic constraints of the region. The boundaries between the low and high frequencies obtained by HVSR are well materialized, at south by Sidi El Kebir river, at west by Chiffa river and in the central part by a line of direction SE-NW corresponding to the old passage of Sidi El Kebir river. The presence of low frequencies attributed to the old alluvial deposits with significant thicknesses that originate just after Sidi El Kebir river confirms that the South Mitidjian contact is subvertical.

River Export of Dissolved and Particulate Organic Carbon from Permafrost and Peat Deposits across the Siberian Arctic

NASA Astrophysics Data System (ADS)

Wild, B.; Andersson, A.; Bröder, L.; Vonk, J.; Hugelius, G.; McClelland, J. W.; Raymond, P. A.; Gustafsson, O.

2017-12-01

Permafrost and peat deposits of northern high latitudes store more than 1300 Pg of organic carbon. This carbon has been preserved for thousands of years by cold and moist conditions, but is now increasingly mobilized as temperatures rise. While part will be degraded to CO2 and CH4 and amplify global warming, part will be exported by rivers to the Arctic Ocean where it can be degraded or re-buried by sedimentation. We here use the four large Siberian rivers Ob, Yenisey, Lena, and Kolyma as natural integrators of carbon mobilization in their catchments. We apply isotope based source apportionments and Markov Chain Monte Carlo Simulations to quantify contributions of organic carbon from permafrost and peat deposits to organic carbon exported by these rivers. More specifically, we compare the 14C signatures of dissolved and particulate organic carbon (DOC, POC) sampled close to the river mouths with those of five potential carbon sources; (1) recent aquatic and (2) terrestrial primary production, (3) the active layer of permafrost soils, (4) deep Holocene deposits (including thermokarst and peat deposits) and (5) Ice Complex Deposits. 14C signatures of these endmembers were constrained based on extensive literature review. We estimate that the four rivers together exported 2.4-4.5 Tg organic carbon from permafrost and peat deposits per year. While total organic carbon export was dominated by DOC (90%), the export of organic carbon from permafrost and peat deposits was more equally distributed between DOC (56%) and POC (44%). Recent models predict that ca. 200 Pg carbon will be lost as CO2 or CH4 by 2100 (RCP8.5) from the circumarctic permafrost area, of which roughly a quarter is drained by the Ob, Yenisey, Lena, and Kolyma rivers. Our comparatively low estimates of river carbon export thus suggest limited transfer of organic carbon from permafrost and peat deposits to high latitude rivers, or its rapid degradation within rivers. Our findings highlight the importance of both DOC and POC, and its degradation, for the fate of carbon mobilized from high latitude deposits under global warming, and indicate a low potential for its stabilization in the Arctic Ocean.

Intermittent ephemeral river-breaching

NASA Astrophysics Data System (ADS)

Reniers, A. J.; MacMahan, J. H.; Gallagher, E. L.; Shanks, A.; Morgan, S.; Jarvis, M.; Thornton, E. B.; Brown, J.; Fujimura, A.

2012-12-01

In the summer of 2011 we performed a field experiment in Carmel River State Beach, CA, at a time when the intermittent natural breaching of the ephemeral Carmel River occurred due to an unusually rainy period prior to the experiment associated with El Nino. At this time the river would fill the lagoon over the period of a number of days after which a breach would occur. This allowed us to document a number of breaches with unique pre- and post-breach topographic surveys, accompanying ocean and lagoon water elevations as well as extremely high flow (4m/s) velocities in the river mouth during the breaching event. The topographic surveys were obtained with a GPS-equipped backpack mounted on a walking human and show the evolution of the river breaching with a gradually widening and deepening river channel that cuts through the pre-existing beach and berm. The beach face is qualified as a steep with an average beach slope of 1:10 with significant reflection of the incident waves (MacMahan et al., 2012). The wave directions are generally shore normal as the waves refract over the deep canyon that is located offshore of the beach. The tide is mixed semi-diurnal with a range on the order of one meter. Breaching typically occurred during the low-low tide. Grain size is highly variable along the beach with layers of alternating fine and coarse material that could clearly be observed as the river exit channel was cutting through the beach. Large rocky outcroppings buried under the beach sand are also present along certain stretches of the beach controlling the depth of the breaching channel. The changes in the water level measured within the lagoon and the ocean side allows for an estimate of the volume flux associated with the breach as function of morphology, tidal elevation and wave conditions as well as an assessment of the conditions and mechanisms of breach closure, which occurred on the time scale of O(0.5 days). Exploratory model simulations will be presented at the conference examining the processes responsible for the development of the river breaching from the initial stages to a wide-open river flow and subsequent closure.

Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 2002-2003 Annual Report.

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

Walters, Jody P.

Rainbow trout Oncorhynchus mykiss provide the most important sport fishery in the Kootenai River, Idaho, but densities and catch rates are low. Low recruitment is one possible factor limiting the rainbow trout population. Bull trout Salvelinus confluentus also exist in the Kootenai River, but little is known about this population. Research reported here addresses the following objectives for the Kootenai River, Idaho: increase rainbow trout recruitment, identify rainbow and bull trout spawning tributaries and migration timing, establish baseline data on bull trout redd numbers in tributaries, and improve the rainbow trout population size structure. Six adult rainbow trout were movedmore » to spawning habitat upstream of a potential migration barrier on Caboose Creek, but numbers of redds and age-0 out-migrants did not appear to increase relative to a reference stream. Measurements taken on the Moyie River indicated the gradient is inadequate to deliver suitable flows to a proposed rainbow trout spawning channel. Summer water temperatures measured in the Deep Creek drainage sometimes exceeded 24 C, higher than those reported as suitable for rainbow trout. Radio-tagged rainbow trout were located in Boulder Creek during the spring spawning season, and bull trout were located in the Moyie River and O'Brien Creek, Montana in the fall. Bull trout spawning migration timing was related to increases in Kootenai River flows. Bull trout redd surveys documented 19 redds on Boulder Creek and North and South Callahan creeks. Fall 2002 electrofishing showed that the Kootenai River rainbow trout proportional stock density was 54, higher than prior years when more liberal fishing regulations were in effect. Boulder Creek produces the highest number of age-0 rainbow trout out-migrants upstream of Bonners Ferry, but the survival rate of these out-migrants upon reaching the Kootenai River is unknown. Determining juvenile survival rates and sources of mortality could aid management efforts to increase rainbow trout recruitment. North and South Callahan creeks support the largest spawning population of bull trout in the Kootenai River drainage, Idaho, so management of the watershed should consider bull trout as high priority.« less

Sources and distributions of branched and isoprenoid tetraether lipids on the Amazon shelf and fan: Implications for the use of GDGT-based proxies in marine sediments

NASA Astrophysics Data System (ADS)

Zell, Claudia; Kim, Jung-Hyun; Hollander, David; Lorenzoni, Laura; Baker, Paul; Silva, Cleverson Guizan; Nittrouer, Charles; Sinninghe Damsté, Jaap S.

2014-08-01

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) in river fan sediments have been used successfully to reconstruct mean annual air temperature (MAAT) and soil pH of the Congo River drainage basin. However, in a previous study of Amazon deep-sea fan sediments the reconstructed MAATs were ca. 10 °C colder than the actual MAAT of the Amazon basin. In this study we investigated this apparent offset, by comparing the concentrations and distributions of brGDGTs in Amazon River suspended particulate matter (SPM) and sediments to those in marine SPM and surface sediments. The riverine brGDGT input was evident from the elevated brGDGT concentrations in marine SPM and surface sediments close to the river mouth. The distributions of brGDGTs in marine SPM and sediments varied widely, but generally showed a higher relative abundance of methylated and cyclic brGDGTs than those in the river. Since this difference in brGDGT distribution was also found in intact polar lipid (IPL)-derived brGDGTs, which were more recently produced, the change in the marine brGDGT distribution was most likely due to marine in situ production. Consequently, the MAATs calculated based on the methylation of branched tetraethers (MBT) and the cyclisation of branched tetraethers (CBT) were lower and the CBT-derived pH values were higher than those of the Amazon basin. However, SPM and sediments from stations close to the river mouth still showed MBT/CBT values that were similar to those of the river. Therefore, we recommend caution when applying the MBT/CBT proxy, it should only be used in sediment cores that were under high river influence. The influence of riverine derived isoprenoid GDGT (isoGDGT) on the isoGDGT-based TEX86 temperature proxy was also examined in marine SPM and sediments. An input of riverine isoGDGTs from the Amazon River was apparent, but its influence on the marine TEX86 was minor since the TEX86 of SPM in the Amazon River was similar to that in the marine SPM and sediments.

The Bonneville Flood—A veritable débâcle: Chapter 6

USGS Publications Warehouse

O'Connor, Jim E.

2016-01-01

The Bonneville Flood was one of the largest floods on Earth. First discovered by G.K. Gilbert in the 1870s during his inspection of the outlet at Red Rock Pass, it was rediscovered in the 1950s by Harold Malde and coworkers, leading to mapping and assessment of spectacular flood features along Marsh Creek, Portneuf River, and Snake River for over 1100 km between the outlet and Lewiston, Idaho. The cataclysmic flood—from the rapid ~ 115 m drop of Lake Bonneville from the Bonneville level to the Provo level—was nearly 200 m deep in places and flowed at a maximum rate of about 1 million m3 s− 1; about 100 times greater than any historical Snake River flood. Along its route the Bonneville Flood carved canyons and cataract complexes and built massive boulder bars. These flood features have been a rich source for understanding megaflood processes. Yet it still offers much more with new and developing techniques for hydrodynamic modeling and landscape analysis.

Winter diel habitat use and movement by subadult bull trout in the upper Flathead River, Montana

USGS Publications Warehouse

Muhlfeld, Clint C.; Glutting, Steve; Hunt, Rick; Daniels, Durae; Marotz, Brian

2003-01-01

We evaluated the diel habitat use and movement of subadult bull trout Salvelinus confluentus by use of radiotelemetry during winter in the upper Flathead River, Montana. Of the 13 monitored bull trout, 12 (92%) made at least one diel movement to other habitat locations during their respective day–night tracking surveys and moved an average of 73% of the time. The median distance moved from day to night locations by the mobile fish was 86 m (range, 27–594 m). Diel shifts in habitat use by nine of the tagged fish were related to light intensity; nocturnal emergence generally commenced immediately after the onset of night, and daytime concealment occurred at daybreak. When diel shifts in microhabitat use occurred, subadult bull trout moved from deep, midchannel areas during the day to shallow, low-velocity areas along the channel margins without overhead cover at night. Resource managers who wish to protect the overwintering habitat features preferred by subadult bull trout in the upper Flathead River should use natural flow management strategies that maximize and stabilize channel margin habitats at night.

Fluvial architecture of dinosaur bonebeds in the Cretaceous Judith River Formation, south-central Montana

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

Wilson, K.M.; Dodson, P.; Fiorillo, A.R.

1991-03-01

Fluvial architecture of dinosaur bonebeds in the Cretaceous Judith River Formation, south-central Montana, has been the subject of intensive paleontological study for many years. However, little has been published on the sedimentology of the formation in this area. The authors have completed a preliminary field study of fluvial facies, with a view towards correcting this omission. Initial results include detailed facies descriptions and maps for five quarries along a line of transect stretching some 40 km parallel to depositional dip. Facies identified are predominantly overbank splays and levees, with common point bar/alluvial channel units and occasional small, possibly estuarine sandmore » bodies in parts of the section. Shell beds (mainly oysters) and bedded, 1 m thick coals are also significant in some sections. Preliminary attempts at paleohydrology suggest river channels in some parts of the section were about 100 m wide and 2 m deep; however, other parts of the section exhibit much larger channel widths. Channel stacking is common. Preliminary results suggest a strong correlation between the occurrence of reddish brown carbonaceous silty shales, and dinosaur bone deposits.« less

Tracking small mountainous river derived terrestrial organic carbon across the active margin marine environment

NASA Astrophysics Data System (ADS)

Childress, L. B.; Blair, N. E.; Orpin, A. R.

2015-12-01

Active margins are particularly efficient in the burial of organic carbon due to the close proximity of highland sources to marine sediment sinks and high sediment transport rates. Compared with passive margins, active margins are dominated by small mountainous river systems, and play a unique role in marine and global carbon cycles. Small mountainous rivers drain only approximately 20% of land, but deliver approximately 40% of the fluvial sediment to the global ocean. Unlike large passive margin systems where riverine organic carbon is efficiently incinerated on continental shelves, small mountainous river dominated systems are highly effective in the burial and preservation of organic carbon due to the rapid and episodic delivery of organic carbon sourced from vegetation, soil, and rock. To investigate the erosion, transport, and burial of organic carbon in active margin small mountainous river systems we use the Waipaoa River, New Zealand. The Waipaoa River, and adjacent marine depositional environment, is a system of interest due to a large sediment yield (6800 tons km-2 yr-1) and extensive characterization. Previous studies have considered the biogeochemistry of the watershed and tracked the transport of terrestrially derived sediment and organics to the continental shelf and slope by biogeochemical proxies including stable carbon isotopes, lignin phenols, n-alkanes, and n-fatty acids. In this work we expand the spatial extent of investigation to include deep sea sediments of the Hikurangi Trough. Located in approximately 3000 m water depth 120 km from the mouth of the Waipaoa River, the Hikurangi Trough is the southern extension of the Tonga-Kermadec-Hikurangi subduction system. Piston core sediments collected by the National Institute of Water and Atmospheric Research (NIWA, NZ) in the Hikurangi Trough indicate the presence of terrestrially derived material (lignin phenols), and suggest a continuum of deposition, resuspension, and transport across the margin. Based on tephra beds identified within the sediments, this material was likely transported by a series of turbidite events, delivered to the Hikurangi Trough through Poverty Canyon.

Computational modeling of river flow using bathymetry collected with an experimental, water-penetrating, green LiDAR

NASA Astrophysics Data System (ADS)

Kinzel, P. J.; Legleiter, C. J.; Nelson, J. M.

2009-12-01

Airborne bathymetric Light Detection and Ranging (LiDAR) systems designed for coastal and marine surveys are increasingly being deployed in fluvial environments. While the adaptation of this technology to rivers and streams would appear to be straightforward, currently technical challenges remain with regard to achieving high levels of vertical accuracy and precision when mapping bathymetry in shallow fluvial settings. Collectively these mapping errors have a direct bearing on hydraulic model predictions made using these data. We compared channel surveys conducted along the Platte River, Nebraska, and the Trinity River, California, using conventional ground-based methods with those made with the hybrid topographic/bathymetric Experimental Advanced Airborne Research LiDAR (EAARL). In the turbid and braided Platte River, a bathymetric-waveform processing algorithm was shown to enhance the definition of thalweg channels over a more simplified, first-surface waveform processing algorithm. Consequently flow simulations using data processed with the shallow bathymetric algorithm resulted in improved prediction of wetted area relative to the first-surface algorithm, when compared to the wetted area in concurrent aerial imagery. However, when compared to using conventionally collected data for flow modeling, the inundation extent was over predicted with the EAARL topography due to higher bed elevations measured by the LiDAR. In the relatively clear, meandering Trinity River, bathymetric processing algorithms were capable of defining a 3 meter deep pool. However, a similar bias in depth measurement was observed, with the LiDAR measuring the elevation of the river bottom above its actual position, resulting in a predicted water surface higher than that measured by field data. This contribution addresses the challenge of making bathymetric measurements with the EAARL in different environmental conditions encountered in fluvial settings, explores technical issues related to reliably detecting the water surface and river bottom, and illustrates the impact of using LiDAR data and current processing techniques to produce above and below water topographic surfaces for hydraulic modeling and habitat applications.

Regional groundwater characteristics and hydraulic conductivity based on geological units in Korean peninsula

NASA Astrophysics Data System (ADS)

Kim, Y.; Suk, H.

2011-12-01

In this study, about 2,000 deep observation wells, stream and/or river distribution, and river's density were analyzed to identify regional groundwater flow trend, based on the regional groundwater survey of four major river watersheds including Geum river, Han river, Youngsan-Seomjin river, and Nakdong river in Korea. Hydrogeologial data were collected to analyze regional groundwater flow characteristics according to geological units. Additionally, hydrological soil type data were collected to estimate direct runoff through SCS-CN method. Temperature and precipitation data were used to quantify infiltration rate. The temperature and precipitation data were also used to quantify evaporation by Thornthwaite method and to evaluate groundwater recharge, respectively. Understanding the regional groundwater characteristics requires the database of groundwater flow parameters, but most hydrogeological data include limited information such as groundwater level and well configuration. In this study, therefore, groundwater flow parameters such as hydraulic conductivities or transmissivities were estimated using observed groundwater level by inverse model, namely PEST (Non-linear Parameter ESTimation). Since groundwater modeling studies have some uncertainties in data collection, conceptualization, and model results, model calibration should be performed. The calibration may be manually performed by changing parameters step by step, or various parameters are simultaneously changed by automatic procedure using PEST program. In this study, both manual and automatic procedures were employed to calibrate and estimate hydraulic parameter distributions. In summary, regional groundwater survey data obtained from four major river watersheds and various data of hydrology, meteorology, geology, soil, and topography in Korea were used to estimate hydraulic conductivities using PEST program. Especially, in order to estimate hydraulic conductivity effectively, it is important to perform in such a way that areas of same or similar hydrogeological characteristics should be grouped into zones. Keywords: regional groundwater, database, hydraulic conductivity, PEST, Korean peninsular Acknowledgements: This work was supported by the Radioactive Waste Management of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (2011T100200152)

An assessment on CO2 geosequestration in deep saline formations in the Taihsi Basin, central Taiwan

NASA Astrophysics Data System (ADS)

Cai, Mo-Si; Lin, Andrew T.; Fan, Jhen-Huei

2015-04-01

Geological storage of carbon dioxide (CO2) is to inject and store a large amount of anthropogenic CO2 in deep and sealed porous rocks in order to mitigate the aggravated threat of global climate changes. Borehole and reflection seismic data are used to understand the spatial distribution of suitable CO2 reservoirs and cap rocks in the Taihsi Basin, central Taiwan, where the level of seismicity is low. The Taihsi Basin was a rift basin during the Paleocene to Eocene, followed by a phase of post-rift subsidence during late Oligocene to late Miocene. The loading of the Taiwan mountain belt since late Miocene has turned the Taihsi Basin into a peripheral foreland basin, with strata gently dipping toward the mountain belts in the east. The coastal plain in central Taiwan (Changhua and Yunlin Counties) and its adjacent offshore areas are close to major CO2 emission sources and no active geological structures are found in these areas, making the study area a favorable CO2 storage site. Spatial distribution of formation thickness and depth for CO2 reservoirs and cap rocks indicates three CO2 storage systems existed in the study area. They are: (1) late Miocene to Pliocene Nanchuang Formation and Kueichulin Formation (reservoirs)-Chinshui Shale (seals) system (hereafter abbreviated as NK-C system), (2) early to middle Miocene Shihti Formation and Peiliao Formation (reservoirs)-Talu Shale (seals) system (SP-T system), (3) early Miocene Mushan Formation (reservoirs)-Piling Shale (seals) system (M-P system). The NK-C system contains multiple layers of porous sandstones from Nanchuang and Kueichulin formations, with total thickness around 210-280 m. In the vicinity of the northern bank of the Jhuoshuei River, reservoir top reaches a depth around 1850 m, with 60 m thick seal formation, the Chinshui Shale. However, the Chinshui Shale becomes sand-prone in the Changhua coastal and nearshore areas due to facies changes. The SP-T system consists of two porous sandstone layers from the Peiliao Formation and the underlying Shihti Formation, with thickness spanning in the range of 30-60 m and 40-60 m, respectively. Reservoir top reaches a depth around 2200 m, with average 150 m thick seal formation, the Talu Shale, in the vicinity of the northern bank of the Jhuoshuei River. The M-P system contains multiple layers of porous sandstones from Mushan Formation, with total thickness around 150-300 m. In the vicinity of the northern bank of the Jhuoshuei River and the southern bank of the Wu River, reservoir top reaches a depth around 2700 m and over 3000 m respectively, with 80-150 m thick seal formation, the Piling Shale. However, Mushan Formation thins southwardly toward the Peikang High and is locally absent in the vicinity of the southern bank of the Jhuoshuei River. For the NK-C system, although it contains thick reservoirs the seal formation (i.e. the Chinshui Shale) becomes sand-prone due to facies changes, leading to a higher risk of sealing capability. For the SP-T and M-P systems, both reservoirs and seals are all thick enough to contain injected CO2, excluding a local area in the vicinity of southern bank of the Jhuoshuei River, where reservoir is absent for the M-P system. In addition, north of the study area and close to the Wu River, reservoirs for the M-P system reach a depth more than 3000 m, a depth too deep for storing CO2 economically. Our results indicate that the SP-T system is the most prominent option for CO2 geosequestration in terms of depths and formation thicknesses, with M-P and NK-C systems as alternative ones, respectively.

Forecasting changes in water quality in rivers associated with growing biofuels in the Arkansas-White-Red river drainage, USA

DOE PAGES

Jager, Henriette I.; Baskaran, Latha M.; Schweizer, Peter E.; ...

2014-05-15

We study that the mid-section of the Arkansas-White-Red (AWR) river basin near the 100 th parallel is particularly promising for sustainable biomass production using cellulosic perennial crops and residues. Along this longitudinal band, precipitation becomes limiting to competing crops that require irrigation from an increasingly depleted groundwater aquifer. In addition, the deep-rooted perennial, switchgrass, produces modest-to-high yields in this region with minimal inputs and could compete against alternative crops and land uses at relatively low cost. Previous studies have also suggested that switchgrass and other perennial feedstocks offer environmentally benign alternatives to corn and corn stover. However, water quality implicationsmore » remain a significant concern for conversion of marginal lands to bioenergy production because excess nutrients produced by agriculture for food or for energy contribute to eutrophication in the dead-zone in the Gulf of Mexico. This study addresses water quality implications for the AWR river basin. We used the SWAT model to compare water quality in rivers draining a baseline, pre-cellulosic-bioenergy and post-cellulosic-bioenergy landscapes for 2022 and 2030. Simulated water quality responses varied across the region, but with a net tendency toward decreased amounts of nutrient and sediment, particularly in subbasins with large areas of bioenergy crops in 2030 future scenarios. We conclude that water quality is one aspect of sustainability for which cellulosic bioenergy production in this region holds promise.« less

Identifying the hydrochemical characteristics of rivers and groundwater by multivariate statistical analysis in the Sanjiang Plain, China

NASA Astrophysics Data System (ADS)

Cao, Yingjie; Tang, Changyuan; Song, Xianfang; Liu, Changming; Zhang, Yinghua

2016-06-01

Two multivariate statistical technologies, factor analysis (FA) and discriminant analysis (DA), are applied to study the river and groundwater hydrochemistry and its controlling processes in the Sanjiang Plain of the northeast China. Factor analysis identifies five factors which account for 79.65 % of the total variance in the dataset. Four factors bearing specific meanings as the river and groundwater hydrochemistry controlling processes are divided into two groups, the "natural hydrochemistry evolution" group and the "pollution" group. The "natural hydrochemistry evolution" group includes the salinity factor (factor 1) caused by rock weathering and the residence time factor (factor 2) reflecting the groundwater traveling time. The "pollution" group represents the groundwater quality deterioration due to geogenic pollution caused by elevated Fe and Mn (factor 3) and elevated nitrate (NO3 -) introduced by human activities such as agriculture exploitations (factor 5). The hydrochemical difference and hydraulic connection among rivers (surface water, SW), shallow groundwater (SG) and deep groundwater (DG) group are evaluated by the factor scores obtained from FA and DA (Fisher's method). It is showed that the river water is characterized as low salinity and slight pollution, and the shallow groundwater has the highest salinity and severe pollution. The SW is well separated from SG and DG by Fisher's discriminant function, but the SG and DG can not be well separated showing their hydrochemical similarities, and emphasize hydraulic connections between SG and DG.

The impact of sewage-contaminated river water on groundwater ammonium and arsenic concentrations at a riverbank filtration site in central Delhi, India

NASA Astrophysics Data System (ADS)

Groeschke, Maike; Frommen, Theresa; Taute, Thomas; Schneider, Michael

2017-11-01

The groundwater abstracted at a well field near the Yamuna River in Central Delhi, India, has elevated ammonium (NH4 +) concentrations up to 35 mg/L and arsenic (As) concentrations up to 0.146 mg/L, constituting a problem with the provision of safe drinking and irrigation water. Infiltrating sewage-contaminated river water is the primary source of the NH4 + contamination in the aquifer, leading to reducing conditions which probably trigger the release of geogenic As. These conclusions are based on the evaluation of six 8-27-m deep drillings, and 13 surface-water and 69 groundwater samples collected during seven field campaigns (2012-2013). Results indicate that losing stream conditions prevail and the river water infiltrates into the shallow floodplain aquifer (up to 16 m thickness), which consists of a 1-2-m thick layer of calcareous nodules (locally known as kankar) overlain by medium sand. Because of its higher hydraulic conductivity (3.7 × 10-3 m/s, as opposed to 3.5 × 10-4 m/s in the sand), the kankar layer serves as the main pathway for the infiltrating water. However, the NH4 + plume front advances more rapidly in the sand layer because of its significantly lower cation exchange capacity. Elevated As concentrations were only observed within the NH4 + plume indicating a causal connection with the infiltrating reducing river water.

Deep Time Ecosystem Engineers: The Correlation between Palaeozoic Vegetation, Evolution of Physical Riverine Habitats, and Plant and Animal Terrestrialization

NASA Astrophysics Data System (ADS)

Davies, N. S.; Gibling, M. R.

2012-04-01

Evidence from the deep time geological record attests to the fundamental importance of plant life to the construction of physical habitats within fluvial environments. Data from an extensive literature review and original fieldwork has demonstrated that many landforms and geomorphic features present in modern river systems do not appear in the deep time stratigraphic record until terrestrial vegetation had adopted certain evolutionary advances that enabled them: for example, stable point bars are associated with the development of deep rooting in the Siluro-Devonian and avulsive anabranching fluvial systems appear at the same time as extensive arborescent vegetation in the Carboniferous. In this presentation, we demonstrate a correlation between the diversification of physical fluvial sedimentary environments and the expansion of terrestrial fauna and flora throughout the Cambrian to Carboniferous, and offer an explanation for this observation that considers plants as ecosystem engineers on an evolutionary timescale. Many extrinsic factors have been considered when attempting to identify controls on the evolutionary timelines of terrestrialization for various different organisms. Factors such as O2 and CO2 levels in the atmosphere, climatic events, global tectonic organisation, sea-level changes, extinction events, weathering rates and nutrient supply are all known to have played a role. However, another factor is likely to have been a fundamental prerequisite for achieving terrestrial biodiversity: the variety of physical habitats available for newly evolved organisms. In fluvial environments, this is a function of the diversity of hydrodynamic regimes (both temporal and spatial) within the world's river systems. In a world where only sheet-like ephemeral braided rivers existed, such as appears to be the case in pre-vegetation settings, both the geographic extent of riparian margins and the diversity of hydrodynamic regimes would be minimal. However, as fluvial corridors narrowed throughout the Ordovician and Silurian, the potential importance of riparian zones as a global biome would have increased as they became more extensive in continental environments. Furthermore, the move towards climatic controls on the ephemeral or perennial nature of streams would have boosted the diversity of temporally diverse hydrodynamic regimes. As single-thread meandering channels and extensive muddy floodplains, stabilised by vegetation, became significant components of the global suite of alluvial geomorphic components throughout the Siluro-Devonian, further diversification of the extent and diversity of physical habitats within the global riparian biome occurred. Into the Carboniferous, the evolution of the anabranching habit within alluvial systems created further new physical landforms for colonization and would have promoted increasingly complex hyporheic flow regimes. Furthermore the associated advent of arborescent vegetation and, specifically, the large woody debris supplied by this, would have created a wealth of new microhabitats for continental organisms. The expanding extent and diversity of physical alluvial niches during the Palaeozoic can be argued to be an underappreciated driver of the terrestrialization of early continental life. The study of the deep time fossil and stratigraphic record also illustrates that vegetation is a fundamental prerequisite for the creation of biogeomorphic alluvial landforms and physical habitats and microhabitats.

Characteristics of streams and aquifers and processes affecting the salinity of water in the upper Colorado River basin, Texas

USGS Publications Warehouse

Slade, R.M.; Buszka, P.M.

1994-01-01

The chemical characteristics of the saline water in streams and shallow aquifers in the study area were compared to characteristics of water that would result from the probable processes affecting the salinity of water, such as evapotranspiration, mineral dissolution, and mixing of water from streams and shallow-aquifer water with brines from deep aquifers. Dissolution of halite or mixing with deep-aquifer water was the most common cause of increased salinity in 48.0 percent of 77 water samples from shallow aquifers, as classified using salt-norm analysis; the second most common cause was the weathering and dissolution of sulfur-bearing minerals. Mixing with water from soil-mineral dissolution was classified as the principal source of chloride in 28.4 percent of 67 water samples from shallow aquifers with nitrate determinations. Trace-species/chloride ratios indicated that mixing with water from deep aquifers in rocks of the Pennsylvanian System was the principal source of chloride in 24.4 percent of 45 shallow-aquifer samples lacking nitrate determinations.

Thermal-history reconstruction of the Baiyun Sag in the deep-water area of the Pearl River Mouth Basin, northern South China Sea

NASA Astrophysics Data System (ADS)

Tang, Xiaoyin; Yang, Shuchun; Hu, Shengbiao

2017-11-01

The Baiyun Sag, located in the deep-water area of the northern South China Sea, is the largest and deepest subbasin in the Pearl River Mouth Basin and one of the most important hydrocarbon-accumulation depression areas in China. Thermal history is widely thought to be of great importance in oil and gas potential assessment of a basin as it controls the timing of hydrocarbon generation and expulsion from the source rock. In order to unravel the paleo-heat flow of the Baiyun Sag, we first analyzed tectonic subsidence of 55 pseudo-wells constructed based on newly interpreted seismic profiles, along with three drilled wells. We then carried out thermal modeling using the multi-stage finite stretching method and calibrated the results using collected present-day vitrinite reflectance data and temperature data. Results indicate that the first and second heating of the Baiyun Sag after 49 Ma ceased at 33.9 Ma and 23 Ma. Reconstructed average basal paleoheat flow values at the end of the rifting periods are 57.7-86.2 mW/m2 and 66.7-97.3 mW/m2, respectively. Following the last heating period at 23 Ma, the study area has undergone a persistent thermal attenuation phase, and basal heat flow has cooled down to 64.0-79.2 mW/m2 at present.

Detection and quantification of hydrocarbons in sediments

USGS Publications Warehouse

Wynn, Jeff; Williamson, Mike; Frank, Jeff

2016-01-01

A new technology developed by the US Geological Survey now allows for fast, direct detection of hydrocarbon plumes both in rivers and drifting in the deep ocean. Recent experiments show that the method can also detect and quantify hydrocarbons buried in river sediments and estuaries. This approach uses a variant of induced polarization, a surface-sensitive physical property of certain polarizable materials immersed in an electrolyte that can accept and adsorb charge under an inducing voltage. Known polarizable materials include most sulfides, ilmenite (FeTiO3), metallic objects such as buried wrecks and pipelines, and now hydrocarbons. The hydrocarbon-in-water response to induced polarization is in fact nearly two orders of magnitude greater than the IP response of any of the hard minerals. The oil:water detection limit for hydrocarbons so far is down to 0.0002% in the laboratory.

Oxynoemacheilus zarzianus, a new loach from the Lesser Zab River drainage in Iraqi Kurdistan (Teleostei: Nemacheilidae).

PubMed

Freyhof, Jörg; Geiger, Matthias

2017-06-02

Oxynoemacheilus zarzianus, new species, is described from the Lesser Zab River drainage, a tributary of the lower Tigris. It is distinguished from other Oxynoemacheilus species in the Tigris drainage by having a slightly emarginate caudal fin, no suborbital groove in males, a complete lateral line, the posterior process of the bony air-bladder capsule directed posteriorly, the flank and posterior part of back covered by scales, short barbels and a deep caudal peduncle. It is the fourth Oxynoemacheilus species known from the Lesser Zab drainage, where such loaches seem to be highly isolated in headwaters. Oxynoemacheilus species diversity in the Euphrates and Tigris drainage is exceptional high. Today 22 species are known from the entire Euphrates and Tigris drainage and 15 from the Tigris drainage alone.

Defining interactions of in-stream hydrokinetic devices in the Tanana River, Alaska

NASA Astrophysics Data System (ADS)

Johnson, J.; Toniolo, H.; Seitz, A. C.; Schmid, J.; Duvoy, P.

2012-12-01

The acceptance, performance, and sustainability of operating in-stream hydrokinetic power generating devices in rivers depends on the impact of the river environment on hydrokinetic infrastructure as well as its impact on the river environment. The Alaska Hydrokinetic Energy Research Center (AHERC) conducts hydrokinetic "impact" and technology studies needed to support a sustainable hydrokinetic industry in Alaska. These include completed and ongoing baseline studies of river hydrodynamic conditions (river stage, discharge, current velocity, power, and turbulence; suspended and bed load sediment transport), ice, fish populations and behavior, surface and subsurface debris flows, and riverbed conditions. Technology and methods studies to minimize the effect of debris flows on deployed turbine system are in-progress to determine their effectiveness at reducing the probability of debris impact, diverting debris and their affect on available river power for conversion to electricity. An anchor point has been placed in the main flow just upstream of Main (Figure 1) to support projects and in preparation for future projects that are being planned to examine hydrokinetic turbine performance including power conversion efficiency, turbine drag and anchor chain loads, wake generation and effects on fish. Baseline fish studies indicate that hydrokinetic devices at the test site will have the most potential interactions with Pacific salmon smolts during their down-migration to the ocean in May and June. At the AHERC test site, the maximum turbulent kinetic energy (TKE) occurs just down stream from the major river bends (e.g., 000 and near the railroad bridge [upper center of the figure]) and over a deep hole at 440 (Figure 1), Minimum TKE occurs between main and 800. River current velocity measurements and simulations of river flow from 000 downstream past the railroad bridge indicate that the most stable current in the river reach is between Main and 800. The stable current and low TKE between Main and 800 indicate that this section of river may be the best site for deploying hydrokinetic devices. Woody debris exists as individual pieces or as large tangled masses on the surface, as full depth vertically oriented debris moving down river and as submerged debris posing a potential hazard to surface or subsurface deployed hydrokinetic devices. Submerged debris consists of logs, root balls, and small (mulch-like) debris. A surface debris diversion device has been tested and shown to be effective at diverting isolated debris and may reduce hazards for surface mounted devices.Figure 1. AHERC Tanana River test site at Nenana, AK.

Geologic features of the Connecticut Valley, Massachusetts, as related to recent floods

USGS Publications Warehouse

Jahns, Richard Henry

1947-01-01

This report gives the results of a geologic study of certain features that bear upon the recent flood behavior of rivers flowing in the Massachusetts part of the Connecticut Valley. It is in part an outline of the physiographic history of the Connecticut River, a 'history that is treated in progressively greater detail as it concerns events occurring from Mesozoic time to the present, and in part a discussion of erosional and depositional processes associated with the extraordinary floods of March 1936 and September 1938. The Connecticut River flows southward through Massachusetts in a broad lowland area of more than 400 square miles and is joined in this area by four large tributaries, the Deerfield and Westfield Rivers from the west and the Millers and Chicopee Rivers from the east. The lowland area, or :Connecticut Valley province, is flanked on the west by the Berkshire Hills, a, deeply incised uplifted plateau, and on the east by the central upland, or Worcester .County plateau, a lower upland marked by rolling topography. Most of the broad, relatively flat valley floor is underlain by Triassic sedimentary rocks. Rising above it, however, are the prominent Holyoke-Mount Tom and Deerfield Ranges, which consist in large part of dark-colored igneous rocks, also of Triassic age. There is evidence of several cycles of erosion in central western Massachusetts, the last two of which are of Tertiary age and appear to have reached nature and very youthful stages of topographic development, respectively. Immediately prior to the glacial epoch, therefore, the Connecticut River flowed in a fairly narrow, deep gorge, which it had incised in the rather flat 5ottom of the valley that it had formed at an earlier stage. A Pleistocene crustal subsidence probably of several hundred feet, for which there has been only partial compensation in postglacial time, was responsible for the present position of much of this gorge below sea level. That an estuary does not now occupy the gorge is due to a filling by glacial debris, notably by sediments deposited in late glacial lakes. Following disappearance of the last ice sheet and draining of the associated, lakes, the Connecticut River resumed existence and began a new chapter in its history. In those areas where the river regained its preglacial course, it now flows on sediments considerably above the rock floor of the old gorge. Where the gorge was narrow and deep, the upper parts of its walls have confined the postglacial river within rather narrow limits, as in the northern part of the state. Where it was sufficiently wide to be filled by glacial sediments over large areas, the postglacial river has meandered broadly, as in the area north of the Holyoke-Mount Tom Range. In two areas in Massachusetts and in one immediately south in Connecticut, however, the river was forced from its preglacial gorge, and its new channel has been superimposed on bedrock, with development of rapids and falls. Each of these postglacial rock channels acts as a spillway whose level controls the local base level of the river as far upstream as the next spillway. These spillways are not to be confused with other, more spectacular gorges, which are of preglacial origin and in which the present river does not flow on bedrock. The Recent Connecticut has formed extensive flood plains and terraces through repeated sequences of erosion by lateral corrosion and downward scour, followed by deposition of .silt and sand veneers. These features, although irregular in detail, appear to be assignable to five general levels, whose means are approximately 49, 37, 30, 18, and 10 feet above present mean river level. In addition, an 80-foot terrace in the northern part of the valley was left perched, in its present position when the Connecticut abandoned its course over. a rock barrier near Turners Falls in favor of an adjacent much lower gap. The normal terraces and flood plains, slope very gently away from their riverw

Geophysical Investigation Along the Great Miami River From New Miami to Charles M. Bolton Well Field, Cincinnati, Ohio

USGS Publications Warehouse

Sheets, R.A.; Dumouchelle, D.H.

2009-01-01

Three geophysical profiling methods were tested to help characterize subsurface materials at selected transects along the Great Miami River, in southwestern Ohio. The profiling methods used were continuous seismic profiling (CSP), continuous resistivity profiling (CRP), and continuous electromagnetic profiling (CEP). Data were collected with global positioning systems to spatially locate the data along the river. The depth and flow conditions of the Great Miami River limited the amount and quality of data that could be collected with the CSP and CRP methods. Data from the CSP were generally poor because shallow reflections (less than 5 meters) were mostly obscured by strong multiple reflections and deep reflections (greater than 5 meters) were sparse. However, modeling of CRP data indicated broad changes in subbottom geology, primarily below about 3 to 5 meters. Details for shallow electrical conductivity (resistivity) (less than 3 meters) were limited because of the 5-meter electrode spacing used for the surveys. For future studies of this type, a cable with 3-meter electrode spacing (or perhaps even 1-meter spacing) might best be used in similar environments to determine shallow electrical properties of the stream-bottom materials. CEP data were collected along the entire reach of the Great Miami River. The CRP and CEP data did not correlate well, but the CRP electrode spacing probably limited the correlation. Middle-frequency (3,510 hertz) and high-frequency (15,030 hertz) CEP data were correlated to water depth. Low-frequency (750 hertz) CEP data indicate shallow (less than 5-meter) changes in electrical conductivity. Given the variability in depth and flow conditions on a river such as the Great Miami, the CEP method worked better than either the CSP or CRP methods.

Hydraulic and hydrogeochemical characteristics of a riverbank filtration site in rural India.

PubMed

Boving, T B; Choudri, B S; Cady, P; Cording, A; Patil, K; Reddy, Veerabaswant

2014-07-01

A riverbank filtration (RBF) system was tested along the Kali River in rural part of the state of Karnataka in India. The polluted river and water from open wells served the local population as their principal irrigation water resource and some used it for drinking. Four RBF wells (up to 25 m deep) were installed. The mean hydraulic conductivity of the well field is 6.3 x 10(-3) cm/s and, based on Darcy's law, the water travel time from the river to the principal RBF well (MW3) is 45.2 days. A mixing model based on dissolved silica concentrations indicated that, depending on the distance from the river and closeness to irrigated rice fields, approximately 27 to 73% of the well water originated from groundwater. Stable isotopic data indicates that a fraction of the water was drawn in from the nearby rice fields that were irrigated with river water. Relative to preexisting drinking water sources (Kali River and an open well), RBF well water showed lower concentration of dissolved metals (60.1% zinc, 27.8% cadmium, 83.9% lead, 75.5% copper, 100% chromium). This study demonstrates that RBF technology can produce high-quality water from low-quality surface water sources in a rural, tropical setting typical for many emerging economies. Further, in parts of the world where flood irrigation is common, RBF well water may draw in infiltrated irrigation water, which possibly alters its geochemical composition. A combination of more than one mixing model, silica together with stable isotopes, was shown to be useful explaining the origin of the RBF water at this study site.

Paleogeomorphology of the early Colorado River inferred from relationships in Mohave and Cottonwood Valleys, Arizona, California and Nevada

USGS Publications Warehouse

Pearthree, Philip; House, P. Kyle

2014-01-01

Geologic investigations of late Miocene–early Pliocene deposits in Mohave and Cottonwood valleys provide important insights into the early evolution of the lower Colorado River system. In the latest Miocene these valleys were separate depocenters; the floor of Cottonwood Valley was ∼200 m higher than the floor of Mohave Valley. When Colorado River water arrived from the north after 5.6 Ma, a shallow lake in Cottonwood Valley spilled into Mohave Valley, and the river then filled both valleys to ∼560 m above sea level (asl) and overtopped the bedrock divide at the southern end of Mohave Valley. Sediment-starved water spilling to the south gradually eroded the outlet as siliciclastic Bouse deposits filled the lake upstream. When sediment accumulation reached the elevation of the lowering outlet, continued erosion of the outlet resulted in recycling of stored lacustrine sediment into downstream basins; depth of erosion of the outlet and upstream basins was limited by the water levels in downstream basins. The water level in the southern Bouse basin was ∼300 m asl (modern elevation) at 4.8 Ma. It must have drained and been eroded to a level <150 m asl soon after that to allow for deep erosion of bedrock divides and basins upstream, leading to removal of large volumes of Bouse sediment prior to massive early Pliocene Colorado River aggradation. Abrupt lowering of regional base level due to spilling of a southern Bouse lake to the Gulf of California could have driven observed upstream river incision without uplift. Rapid uplift of the entire region immediately after 4.8 Ma would have been required to drive upstream incision if the southern Bouse was an estuary.

Reconstructing ancient river dynamics from the stratigraphic record: can lessons from the past inform our future?

NASA Astrophysics Data System (ADS)

Hajek, E. A.; Chamberlin, E.; Baisden, T.

2014-12-01

The richness of the deep-time record and its potential for revealing important characteristics of ancient fluvial landscapes has been demonstrated time and again, including compelling examples of rivers altering their behavior in response to changes in vegetation patterns or abrupt shifts in water and sediment discharge. At present, reconstructions of ancient river and floodplain dynamics are commonly qualitative, and when quantitative metrics are used, it is often for comparison among ancient deposits. Without being able to reconstruct, more comprehensively, important aspects of ancient river and floodplains dynamics, this information has only anecdotal relevance for evaluating and managing present-day landscapes. While methods for reconstructing hydrodynamic and morphodynamic aspects of ancient rivers and floodplains are useful, uncertainties associated with these snapshots complicate the ability to translate observations from geologic to engineering scales, thereby limiting the utility of insight from Earth's past in decision-making and development of sustainable landscape-management practices for modern fluvial landscapes. Here, we explore the degree to which paleomorphodynamic reconstructions from ancient channel and floodplain deposits can be used to make specific, quantitative inferences about ancient river dynamics. We compare a suite of paleoenvironmental measurements from a variety of ancient fluvial deposits (including reconstructions of paleoflow depth, paleoslope, paleo-channel mobility, the caliber of paleo-sediment load, and paleo-floodplain heterogeneity) in an effort to evaluate sampling and empirical uncertainties associated with these methods and identify promising avenues for developing more detailed landscape reconstructions. This work is aimed at helping to develop strategies for extracting practicable information from the stratigraphic record that is relevant for sustainably managing and predicting changes in today's environments.

Sources and Transport of Nutrients, Organic Carbon, and Chlorophyll-a in the San Joaquin River Upstream of Vernalis, California, during Summer and Fall, 2000 and 2001

USGS Publications Warehouse

Kratzer, Charles R.; Dileanis, Peter D.; Zamora, Celia; Silva, Steven R.; Kendall, Carol; Bergamaschi, Brian A.; Dahlgren, Randy A.

2004-01-01

Oxidizable materials from the San Joaquin River upstream of Vernalis can contribute to low dissolved oxygen episodes in the Stockton Deep Water Ship Channel that can inhibit salmon migration in the fall. The U.S. Geological Survey collected and analyzed samples at four San Joaquin River sites in July through October 2000 and June through November 2001, and at eight tributary sites in 2001. The data from these sites were supplemented with data from samples collected and analyzed by the University of California at Davis at three San Joaquin River sites and eight tributary sites as part of a separate study. Streamflows in the San Joaquin River were slightly above the long-term average in 2000 and slightly below average in 2001. Nitrate loads at Vernalis in 2000 were above the long-term average, whereas loads in 2001 were close to average. Total nitrogen loads in 2000 were slightly above average, whereas loads in 2001 were slightly below average. Total phosphorus loads in 2000 and 2001 were well below average. These nutrient loads correspond with the flow-adjusted concentration trends--nitrate concentrations significantly increased since 1972 (p 0.05). Loading rates of nutrients and dissolved organic carbon increased in the San Joaquin River in the fall with the release of wetland drainage into Mud Slough and with increased reservoir releases on the Merced River. During August 2000 and September 2001, the chlorophyll-a loading rates and concentrations in the San Joaquin River declined and remained low during the rest of the sampling period. The most significant tributary sources of nutrients were the Tuolumne River, Harding Drain, and Mud Slough. The most significant tributary sources of dissolved organic carbon were Salt Slough, Mud Slough, and the Tuolumne and Stanislaus Rivers. Compared with nutrients and dissolved organic carbon, the tributaries were minor sources of chlorophyll-a, suggesting that most of the chlorophyll-a was produced in the San Joaquin River rather than its tributaries. On the basis of the carbon-to-nitrogen ratios and the d13C of particulate organic matter in the San Joaquin River and tributaries, the particulate organic matter in the river was mostly phytoplankton. On the basis of the d15N values of the particulate organic matter, and of total dissolved nitrogen and nitrate, the nitrate in the San Joaquin River probably was a significant nutrient source for the phytoplankton. The range of d15N and d18O values of nitrate in the San Joaquin River and tributaries suggest that animal waste or sewage was a significant source of nitrate in the river at the time the samples were collected.

Salinization Sources Along the Lower Jordan River Under Draught Conditions

NASA Astrophysics Data System (ADS)

Holtzman, R.; Shavit, U.; Segal, M.; Vengosh, A.; Farber, E.; Gavrieli, I.

2003-12-01

The Lower Jordan River, once a flowing freshwater river, is suffering from an ongoing reduction of discharge and water quality. The river flows between the Sea of Galilee and the Dead Sea, an aerial distance of about 105 Km. The severe reduction is caused by an excessive exploitation of its sources and diversion of sewage and agricultural drainage into the river. The extreme low flows and low water quality threaten the natural existence of the river and its potential use for agriculture. In spite of its importance, little research has been done in the river. The objectives of the study were to measure the discharge and water composition along the river and to evaluate the main sources that control its flow and chemical characteristics. The hypothesis of the study was that interaction with subsurface flows significantly affects the river flow and chemical composition. The research is based on a detailed field study, which included flow rate measurements in the river and its tributaries, water sampling and analysis and mass balance calculations of water and solutes. A portable Acoustic Doppler Velocimeter (ADV) was used to measure velocities and bathymetry at different locations across the river sections. Due to accessibility constraints, a floating traverse construction, which enables the ADV's deployment from one bank of the river, was developed. It was found that flow rate ranges between 500-1,100 L/s in northern (upstream) sections and 300-1,650 L/s in the south. This low discharge represents a significant reduction from historical values and is lower than recent published estimations. This research represents base flows only, as the measurements were done during a period of two consecutive draught years. Calculated mass balance of water flows in the northern sections shows that the subsurface source contributes to the river around 200-670 L/s (30-80% of the river flow). Calculations of solute balance show that the subsurface flows add 20-50% of the mass of solutes (e.g. Sulfate) that flows in the river. The assumption of a hydraulic gradient that points at inflows from subsurface flows is encouraged by high water levels measured in nearby piezometers. Possible natural subsurface sources include shallow groundwater or rising of water from deep formations. The existence of adjacent thermal wells strengthens the reasonability of such water rise. Possible anthropogenic sources include return flows and effluents. The results are consistent and agree with the geochemical and isotopic analyses. It is concluded that the impact of the subsurface component on the Jordan River is significant and must be taken into consideration, for future water management schemes and implementation of the Peace Treaty between Israel and Jordan.

Modern Sedimentation off the Kaoping River, SW Taiwan: A Comparison with Eel River's S2S System

NASA Astrophysics Data System (ADS)

Huh, C.; Lin, H.; Lin, S.

2006-12-01

The Kaoping (KP) River in SW Taiwan has a watershed area of 3257 km2 and an annual sediment discharge of 49 MT. Although the sediment yield of the KP River basin (1.5×104 ton km-2 yr^{- 1}) is the 4th highest among Taiwan's catchment basins, it is nearly one order of magnitude higher than that of the Eel River's basin (~1.8×103 ton km-2 yr-1; the highest in the U.S.). The KP canyon extends almost immediately seaward from the river's mouth and terminates in the northwestern corner of the South China Sea. The head of the canyon is characterized by high and steep walls exceeding 600 m. The KP river's source-to-sink system offers a dramatic case of mountainous rivers at active margins for S2S study. Here we report some results about modern sedimentation in KP river's dispersal system. Seventy-six sediment cores collected from an area of ~3000 km2 were analyzed for fallout nuclides 7Be, 137Cs and 210Pb by gamma spectrometry. From profiles of excess 210Pb and 137Cs sediment accumulation rates in the coring sites were estimated, which vary from 0.06 to 1.6 cm/yr, with the highest rates (>1 cm/yr) distributed in the upper slope (<600 m) on both sides of the KP canyon. The area with high sedimentation rates on Pb-210 time scale coincides with the area covered by a flood layer resulting from Typhoon Haitang during July 18-20, 2005. This suggests that the open margin on the upper slope is a depocenter for sediment dispersed via a surface component of the river's plume on various timescales (from events to centennial). With a total of 76 sampling points laid out, a framework consisting of 105 triangular grids is configured to calculate the budget of sediment in the study area. The calculated budget, at 7.2 MT/yr, accounts for only ~15% of KP river's sediment discharge. We speculate that most of the remainder is exported out of the study area via the KP canyon to the deep sea by gravity-driven turbidity or hyperpycnal flows.

Radiocarbon Depression in Aquatic Foodwebs of the Colorado River, USA: Coupling Between Carbonate Weathering and the Biosphere

NASA Astrophysics Data System (ADS)

Sickman, J. O.; Huang, W.; Lucero, D.; Anderson, M.

2012-12-01

The 14C isotopic composition of living organisms is generally considered to be in isotopic equilibrium with atmosphere CO2. During the course of investigations of aquatic foodwebs of the Colorado River, we measured substantial radiocarbon depression of organisms within planktonic and benthic foodwebs of Copper Basin Reservoir, a short residence-time water body at the intake to the Colorado River Aqueduct. All trophic levels had depressed radiocarbon content with inferred "age" of ca. 1,200 radiocarbon years (range: 0.85 to 0.87 fraction modern carbon (fmc)). Additional measurements of the radiocarbon content of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) were made in other major rivers in California (New (near Salton Sea), Santa Ana (near Riverside), San Joaquin (near Fresno) and Salinas (near San Luis Obispo)). In the New River (which is composed primarily of irrigation tailwater derived from the Colorado River), the radiocarbon values for DIC closely matched those found in biota of the Copper Basin Reservoir (0.85 to 0.87 fmc), but radiocarbon values for DOC were slightly higher (0.91 to 0.95 fmc). In the other California rivers, radiocarbon concentrations in DIC were generally below modern and lower than corresponding levels in DOC; in the case of the Santa Ana River, DOC was older than DIC as a result of wastewater inputs from upstream treatment plants. Together these data suggest that the carbonate equilibrium of California rivers is influenced by weathering of carbonate minerals which produces HCO3- with no 14C. We hypothesize that this dead carbon can move into aquatic foodwebs via algae and phytoplankton uptake during photosynthesis, depressing the 14C content of aquatic foodwebs below that of the atmosphere. Based on a simple two-component mixing model incorporating carbonate weathering and atmospheric CO2, we estimate that 15-17% of the carbon in the aquatic foodweb of Copper Basin is derived directly from mineral weathering of carbonate minerals in the Colorado River basin. Worldwide, only a few cases of radiocarbon depression have been reported for aquatic ecosystems. The extent of 14C depression in the Colorado River is much larger than that observed in the Arctic or deep ocean environments.

Linkages between the circulation and distribution of dissolved organic matter in the White Sea, Arctic Ocean

NASA Astrophysics Data System (ADS)

Pavlov, Alexey K.; Stedmon, Colin A.; Semushin, Andrey V.; Martma, Tõnu; Ivanov, Boris V.; Kowalczuk, Piotr; Granskog, Mats A.

2016-05-01

The White Sea is a semi-enclosed Arctic marginal sea receiving a significant loading of freshwater (225-231 km3 yr-1 equaling an annual runoff yield of 2.5 m) and dissolved organic matter (DOM) from river run-off. We report discharge weighed values of stable oxygen isotope ratios (δ18O) of -14.0‰ in Northern Dvina river for the period 10 May-12 October 2012. We found a significant linear relationship between salinity (S) and δ18O (δ18O=-17.66±0.58+0.52±0.02×S; R2=0.96, N=162), which indicates a dominant contribution of river water to the freshwater budget and little influence of sea ice formation or melt. No apparent brine additions from sea-ice formation is evident in the White Sea deep waters as seen from a joint analysis of temperature (T), S, δ18O and aCDOM(350) data, confirming previous suggestions about strong tidal induced vertical mixing in winter being the likely source of the deep waters. We investigated properties and distribution of colored dissolved organic matter (CDOM) and dissolved organic carbon (DOC) in the White Sea basin and coastal areas in summer. We found contrasting DOM properties in the inflowing Barents Sea waters and White Sea waters influenced by terrestrial runoff. Values of absorption by CDOM at 350 nm (aCDOM(350)) and DOC (exceeding 10 m-1 and 550 μmol l-1, respectively) in surface waters of the White Sea basin are higher compared to other river-influenced coastal Arctic domains. Linear relationship between S and CDOM absorption, and S and DOC (DOC=959.21±52.99-25.80±1.79×S; R2=0.85; N=154) concentrations suggests conservative mixing of DOM in the White Sea. The strongest linear correlation between CDOM absorption and DOC was found in the ultraviolet (DOC=56.31±2.76+9.13±0.15×aCDOM(254); R2=0.99; N=155), which provides an easy and robust tool to trace DOC using CDOM absorption measurements as well as remote sensing algorithms. Deviations from this linear relationship in surface waters likely indicate contribution from different rivers along the coast of the White Sea. Characteristics of CDOM further indicate that there is limited removal or change in the DOM pool before it exits to the Barents Sea.

Paleocene Wilcox cross-shelf channel-belt history and shelf-margin growth: Key to Gulf of Mexico sediment delivery

NASA Astrophysics Data System (ADS)

Zhang, Jinyu; Steel, Ronald; Ambrose, William

2017-12-01

Shelf margins prograde and aggrade by the incremental addition of deltaic sediments supplied from river channel belts and by stored shoreline sediment. This paper documents the shelf-edge trajectory and coeval channel belts for a segment of Paleocene Lower Wilcox Group in the northern Gulf of Mexico based on 400 wireline logs and 300 m of whole cores. By quantitatively analyzing these data and comparing them with global databases, we demonstrate how varying sediment supply impacted the Wilcox shelf-margin growth and deep-water sediment dispersal under greenhouse eustatic conditions. The coastal plain to marine topset and uppermost continental slope succession of the Lower Wilcox shelf-margin sediment prism is divided into eighteen high-frequency ( 300 ky duration) stratigraphic sequences, and further grouped into 5 sequence sets (labeled as A-E from bottom to top). Sequence Set A is dominantly muddy slope deposits. The shelf edge of Sequence Sets B and C prograded rapidly (> 10 km/Ma) and aggraded modestly (< 80 m/Ma). The coeval channel belts are relatively large (individually averaging 11-13 m thick) and amalgamated. The water discharge of Sequence Sets B and C rivers, estimated by channel-belt thickness, bedform type, and grain size, is 7000-29,000 m3/s, considered as large rivers when compared with modern river databases. In contrast, slow progradation (< 10 km/Ma) and rapid aggradation (> 80 m/Ma) characterizes Sequence Sets D and E, which is associated with smaller (9-10 m thick on average) and isolated channel belts. This stratigraphic trend is likely due to an upward decreasing sediment supply indicated by the shelf-edge progradation rate and channel size, as well as an upward increasing shelf accommodation indicated by the shelf-edge aggradation rate. The rapid shelf-edge progradation and large rivers in Sequence Sets B and C confirm earlier suggestions that it was the early phase of Lower Wilcox dispersal that brought the largest deep-water sediment volumes into the Gulf of Mexico. Key factors in this Lower Wilcox stratigraphic trend are likely to have been a very high initial sediment flux to the Gulf because of the high initial release of sediment from Laramide catchments to the north and northwest, possibly aided by modest eustatic sea-level fall on the Texas shelf, which is suggested by the early, flat shelf-edge trajectory, high amalgamation of channel belts, and the low overall aggradation rate of the Sequence Sets B and C.

Vegetation Structure and Function along Ephemeral Streams in the Sonoran Desert

NASA Astrophysics Data System (ADS)

Stromberg, J. C.; Katz, G.

2011-12-01

Despite being the most prevalent stream type in the American Southwest, far less is known about riparian ecosystems associated with ephemeral streams than with perennial streams. Patterns of plant composition and structure reflect complex environmental gradients, including water availability and flood intensity, which in turn are related to position in the stream network. A survey of washes in the Sonoran Desert near Tucson, Arizona showed species composition of small ephemeral washes to be comprised largely of upland species, including large seeded shrubs such as Acacia spp. and Larrea tridentata. Small seeded disturbance adapted xerophytic shrubs, such as Baccharis sarothroides, Hymenoclea monogyra and Isocoma tenuisecta, were common lower in the stream network on the larger streams that have greater scouring forces. Because ephemeral streams have multiple water sources, including deep (sometimes perched) water tables and seasonally variable rain and flood pulses, multiple plant functional types co-exist within a stream segment. Deep-rooted phreatophytes, including Tamarix and nitrogen-fixing Prosopis, are common on many washes. Such plants are able to access not only water, but also pools of nutrients, several meters below ground thereby affecting nutrient levels and soil moisture content in various soil strata. In addition to the perennial plants, many opportunistic and shallow-rooted annual species establish during the bimodal wet seasons. Collectively, wash vegetation serves to stabilize channel substrates and promote accumulation of fine sediments and organic matter. In addition to the many streams that are ephemeral over their length, ephemeral reaches also occupy extensive sections of interrupted perennial rivers. The differences in hydrologic conditions that occur over the length of interrupted perennial rivers influence plant species diversity and variability through time. In one study of three interrupted perennial rivers, patterns of herbaceous species richness varied with temporal scale of analysis, with richness being greater at perennial sites over the short-term but greater at non-perennial sites over the long-term (multiple seasons and years). This latter pattern arose owing to the abundance of light, space, and bare ground at the drier sites, combined with a diverse soil seed bank and periodic supply of seasonal soil moisture sufficient to stimulate establishment of cool-season as well as warm-season annuals. The reduced availability of perennial water sources limits the richness, cover, and competitive dominance of herbaceous perennial species, enabling pronounced diversity response to episodic water pulses in the drier river segments. Thus, non-perennial streams and reaches contribute importantly to river-wide and landscape scale desert riparian diversity, supporting high cumulative richness and distinct composition compared to perennial flow reaches.

The Rough Road to Antwerp: The First Canadian Army’s Operations Along the Channel Coast

DTIC Science & Technology

2014-05-22

Dunkirk and the inland deep-water port at Antwerp were required to shorten distances considerably and to provide the added benefit of greatly... Dunkirk became largely irrelevant when the Allies secured Antwerp, which was both more capable, and far closer to the frontlines of the Allied forces...the assault. The German garrison in Dunkirk was bypassed in order to free the First Canadian Army to clear the German forces from the Scheldt River

Naval Ocean Research and Development Activity Journal Index for 1976 thru 1984,

DTIC Science & Technology

1985-03-01

and Antibiotics. Venezuela Basin. Deep-Sea Research, v. 31, Botanica Marina, v. XXIV, p. 399-404. p. 403-414. Thompson, J. Dana (1978). Ocean Deserts...v. 29, n. 102, p. 286-295. Phytoplankton Extracellular Products. Botanica marina, v~. XXXVI, p. 375-381. Radl, C.J. and J.P. Welsh (1983). Inventory...Experiments tion and Antibiotics. Botanica Marina, v. XXIV, in the Indian River Estuary, Florida. Journal of p. 399-404. ?. Marine Research, v. 36, p, 569-593

Seasonal cycles of zooplankton from San Francisco Bay

USGS Publications Warehouse

Ambler, Julie W.; Cloern, James E.; Hutchinson, Anne

1985-01-01

Seasonal cycles of zooplankton abundance appear to be constant among years (1978–1981) and are similar in the deep (>10 m) channels and lateral shoals (<3 m). The seasonal zooplankton community dynamics are discussed in relation to: (1) river discharge which alters salinity distribution and residence time of plankton; (2) temperature which induces production and hatching of dormant copepod eggs; (3) coastal hydrography which brings neritic copepods of different zoogeographic affinities into the bay; and (4) seasonal cycles of phytoplankton.

GREAT I Study of the Upper Mississippi River. Technical Appendixes. Volume 5. Fish and Wildlife. Part II.

DTIC Science & Technology

1980-09-01

Waterlily .1! Kuphar variegatum x X x * : White Waterlily Numphaea tuberosa X X X X X Greater Duckweed Spirodela polrhiz x x Lesser Duckweed Lemna minor ...expected that this would be a minor portion of the project. A channel 6 feet deep and 30 feet wide is desired. 9. Johnson Slough (Clayton County, Iowa...76,276.74. The actual budget may be substantially less, however. MINORITY REPORT Unanimous vote. No minority opinion. ,p Michael Vanderfoy6 Chairman Side

16. Hayden Ditch (Lateral 5), looking west across McClintock Drive ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. Hayden Ditch (Lateral 5), looking west across McClintock Drive toward downtown Tempe. The deep, concrete lined ditch is typical of Rehabilitation and Betterment work. The fenced enclosure in the foreground is an SRP well which supplements the water supply of the ditch. In the background are visible an Arizona State University dormitory and Hayden's Butte. Photographer: Mark Durben, June 1989. Source: SRPA - Tempe Canal, South Side Salt River in Tempe, Mesa & Phoenix, Tempe, Maricopa County, AZ

Water temperatures in select nearshore environments of the Colorado River in Grand Canyon, Arizona, during the Low Steady Summer Flow experiment of 2000

USGS Publications Warehouse

Vernieu, William S.; Anderson, Craig R.

2013-01-01

Water releases from Glen Canyon Dam, Arizona, are the primary determinant of streamflow, sediment transport, water quality, and aquatic and riparian habitat availability in the Colorado River downstream of the dam in Grand Canyon. The presence and operation of the dam have transformed the seasonally warm Colorado River into a consistently cold river because of hypolimnetic, or deep-water, releases from the penstock withdrawal structures on the dam. These releases have substantially altered the thermal regime of the downstream riverine environment. This, in turn, has affected the biota of the river corridor, particularly native and nonnative fish communities and the aquatic food web. In the spring and summer of 2000, a Low Steady Summer Flow experiment was conducted by the U.S. Geological Survey and the Bureau of Reclamation to evaluate the effects of the experimental flow on physical and biological resources of the Colorado River ecosystem downstream from Glen Canyon Dam to Lake Mead on the Arizona-Nevada border. This report describes the water temperatures collected during the experimental flow from 14 nearshore sites in the river corridor in Grand Canyon to assess the effects of steady releases on the thermal dynamics of nearshore environments. These nearshore areas are characterized by low-velocity flows with some degree of isolation from the higher velocity flows in the main channel and are hypothesized to be important rearing environments for young native fish. Water-temperature measurements were made at 14 sites, ranging from backwater to open-channel environments. Warming during daylight hours, relative to main-channel temperatures, was measured at all sites in relation to the amount of isolation from the main-channel current. Boat traffic, amount of direct solar radiation, and degree of isolation from the main-channel current appear to be the primary factors affecting the differential warming of the nearshore environment.

The Physical, Geochemical and Microbial Conditions and Processes in the Hyporheic Zone of a Large Tidally Influenced River: The Fraser River, British Columbia, Canada

NASA Astrophysics Data System (ADS)

Bianchin, M.; Roschinski, T.; Ross, K.; Leslie, S.; William, M.; Beckie, R.

2006-12-01

The objective of this research is to investigate the physical, chemical and biological conditions and processes that occur in the hyporheic zone of the lower Fraser River, British Columbia. The large flows of between 2000 and 10000 cubic meters per second, the 10 15 m deep, 250 m wide channel, the 1 m tidal fluctuations, the localized scour and redeposition of sediments during freshet and the strong geochemical contrast between groundwater and surface water distinguish this investigation from studies on smaller channels and streams and required the development of novel characterization tools and strategies. The geochemistry of water samples collected with a push-in profiler, bulk electrical conductivity (EC) measurements collected with a push-in tool and hydraulic head measurements indicate that groundwater principally discharges into the river approximately 100 m offshore in a 10 m wide band. River water and groundwater mix to a maximum depth of between 0.75 and 1.5 m. While hydraulic heads show strong tidal reversals, bulk EC profiles show only moderate changes during the tidal cycle. It was hypothesized that high iron (10's mg/L of Fe(II)) in reduced groundwater would precipitate from solution as secondary iron-oxide phases in the zone where groundwater mixes with aerobic river water. Sediments were collected with a freeze-shoe corer and depth profiles through the hyporheic zone and into the underlying aquifer were analyzed by selective extractions. The 15-30 mg/g of total extractable iron in both the aquifer and hyporheic zone is relatively high. The lack of noticeable iron accumulation in the hyporheic zone may indicate that iron precipitates on shallow sediments that are subsequently scoured from the river bed during freshet. Microbial DNA from sediments was analyzed using denaturing gradient gel electrophoresis and showed a relatively diverse community structure but an overall low biomass.

Ontogenesis of endangered humpback chub (Gila cypha) in the Little Colorado River, Arizona

USGS Publications Warehouse

Stone, Dennis M.; Gorman, Owen T.

2006-01-01

The largest population of endangered humpback chub Gila cypha inhabits the Colorado River below Glen Canyon Dam and the lower 14 km of the Little Colorado River (LCR), Arizona. Currently, adults from both rivers spawn and their progenies grow and recruit to adulthood primarily within the LCR, where we studied G. cypha's life history using hoop net capture data. Humpback chub undergo an ontogenesis from diurnally active, vulnerable, nearshore-reliant young-of-the-year (YOY; 30-90 mm total length) into nocturnally active, large-bodied adults (a?Y180 mm TL). During the day, adults primarily resided in deep midchannel pools; however, at night they dispersed inshore amongst the higher densities of YOY conspecifics. Many YOY G. cypha shifted to nocturnal habitats that provided greater cover, possibly, to avoid inshore invading adults. These findings mirror predator-prey scenarios described in other freshwater assemblages, but do not refute other plausible hypotheses. Gila cypha piscivorous activity may escalate in hoop nets, which can confine fish of disparate sizes together; adults were significantly associated with YOY conspecifics and small dead fish in hoop nets at night and eight G. cypha (156-372 mm TL) regurgitated and/or defecated other fish body parts during handling following capture. Gila cypha can definitely be piscivorous given the opportunity, but the magnitude of their piscivorous activity in the wild is debatable.

[Limnetic zooplankton run-off a high-head dam and their fate in a river with high current velocity (case of the Krasnoiarsk hydroelectric power station on the Yenisei river].

PubMed

Dubovskaia, O P; Gladyshev, M I; Makhutova, O N

2004-01-01

The vertical distribution of net zooplankton in head-water of Krasnoyarsk hydroelectric power station and its horizontal distribution in the tail-water were studied during two years in winter and summer seasons. In order to distinguish living and dead individuals the special staining was used. It was revealed that on average 77% of living plankton pass through high-head dam with deep water scoop to the tailwater. While passing through dam aggregates some individuals of the reservoir plankton are traumatized and die, that results in some increase of portion of dead individuals in the tail water near dam (from 3 to 6%). Alive zooplankton passed through the dam aggregates is eliminated under the Upper Yenisei highly turbulent conditions. There is approximately 10% of it in 32 km from the dam if compare with biomass in 20-40 m layer of reservoir, the portion of dead increases to 11%. The biomass of zooplankton suspended in the water column of the tail-water sometimes increases (till > 1 g/m3) due to large Copepoda Heteroscope borealis, which inhabits near-bottom and near-shore river zones and can be found in the central part of the river during reproductive period. Limnetic zooplankton from the reservoir cannot be considered as important food for planktivores in the tail-water.

Morphology and mechanism of the very large dunes in the tidal reach of the Yangtze River, China

NASA Astrophysics Data System (ADS)

Shuwei, Zheng; Heqin, Cheng; Shuaihu, Wu; Shengyu, Shi; Wei, Xu; Quanping, Zhou; Yuehua, Jiang

2017-05-01

High-resolution multibeam data was used to interpret the surface morphology of very large dunes (VLDs) in the tidal reach of the Yangtze River, China. These VLDs can be divided into three categories according to their surface morphological characteristics. (1) VLDs-I: those with a smooth surface and cross-section; (2) VLDs-II: those accompanied by secondary dunes; (3) VLDs-III: those accompanied by secondary dunes and numerous elliptical pits. Parameters and spatial distribution of VLDs, and bed surface sediment were analyzed in the laboratory. Overall, channel morphology is an important factor affecting the development of VLDs, and channels with narrow and straight and certain water surface slope are facilitating the development of VLDs by constraining stream power. Meanwhile, distribution density of VLDs depicts a decreasing trend from Chizhou towards the estuary, are probably influenced by channel morphology and width. Associated pits in VLDs-III change the 3D dune morphology by distributing in secondary dunes as beads. The Three Gorges Dam project (TGP) leads to the bed surface sediment activity frequently and leads to the riverbed surface sediment coarsens, which promotes the further development of dunes. Moreover, other human activities, such as river regulation project, sand mining and Deep Water Channel Regulation Project have changed the regional river boundary conditions and hydrodynamic conditions are influential on the development of VLDs.

Seismic stratigraphy and depositional history of late Quaternary deposits at the eastern Yellow Sea shelf

NASA Astrophysics Data System (ADS)

Yoo, Dong-Geun; Lee, Gwang-Soo; Kim, Gil-Young; Chang, Se-Won; Kim, Kyoung-Jin

2017-04-01

The late Quaternary stratigraphy and sedimentation at the eastern Yellow Sea shelf was studied using a dense network of high-resolution, single-channel seismic reflection profiles and sediment data. The shelf sequence in this area consists of six seismic units formed since the LGM. During the LGM, the study area was completely exposed, resulting in subaerial erosion associated with paleo-channel incision by the Huanghe and Korean Rivers. As the shelf was flooded, the incised channels were backfilled fluvial or coastal sediments, forming incised channel-fill deposits (SU1). The paleo-river may have supplied abundant terrigenous sediments to the study area around the paleo-river mouth and adjacent area. These sediments were trapped within the paleo-estuary and formed SU2, regarded as an estuarine deposit. Two types of serial sand ridges (SU3 and SU5) which correspond to transgressive deposits developed. SU3 on the southern part, west of Jeju Island (80 110 m deep) is regarded as a moribund-type mainly formed during the early to middle stage of transgression. These are thought to have ceased growing and remobilizing. In contrast, SU5 (occurring 30 50 m deep off the Korean Peninsula) is generally regarded as active sand ridges deposited during the late stage of transgression and is partly modified by modern tidal currents. As the transgression continued, the near-surface sediments were reworked and redistributed by shelf erosion, resulting in a thin veneer of transgressive sands (SU4). The uppermost unit (SU6) formed the Heuksan Mud Belt (HMB), which is one of the most prominent mud deposits in the Yellow Sea. The lower part of the HMD corresponds to shelf-mud deposited during the late stage of transgression, whereas the upper part consists of a recent shelf-delta developed after the highstand sea level at about 7 ka BP.

Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior

NASA Astrophysics Data System (ADS)

Bröder, Lisa; Tesi, Tommaso; Salvadó, Joan A.; Semiletov, Igor P.; Dudarev, Oleg V.; Gustafsson, Örjan

2016-09-01

Ongoing global warming in high latitudes may cause an increasing supply of permafrost-derived organic carbon through both river discharge and coastal erosion to the Arctic shelves. Mobilized permafrost carbon can be either buried in sediments, transported to the deep sea or degraded to CO2 and outgassed, potentially constituting a positive feedback to climate change. This study aims to assess the fate of terrigenous organic carbon (TerrOC) in the Arctic marine environment by exploring how it changes in concentration, composition and degradation status across the wide Laptev Sea shelf. We analyzed a suite of terrestrial biomarkers as well as source-diagnostic bulk carbon isotopes (δ13C, Δ14C) in surface sediments from a Laptev Sea transect spanning more than 800 km from the Lena River mouth (< 10 m water depth) across the shelf to the slope and rise (2000-3000 m water depth). These data provide a broad view on different TerrOC pools and their behavior during cross-shelf transport. The concentrations of lignin phenols, cutin acids and high-molecular-weight (HMW) wax lipids (tracers of vascular plants) decrease by 89-99 % along the transect. Molecular-based degradation proxies for TerrOC (e.g., the carbon preference index of HMW lipids, the HMW acids / alkanes ratio and the acid / aldehyde ratio of lignin phenols) display a trend to more degraded TerrOC with increasing distance from the coast. We infer that the degree of degradation of permafrost-derived TerrOC is a function of the time spent under oxic conditions during protracted cross-shelf transport. Future work should therefore seek to constrain cross-shelf transport times in order to compute a TerrOC degradation rate and thereby help to quantify potential carbon-climate feedbacks.

Spatial variability of surface-sediment porewater pH and related water-column characteristics in deep waters of the northern South China Sea

NASA Astrophysics Data System (ADS)

Shao, Changgao; Sui, Yi; Tang, Danling; Legendre, Louis

2016-12-01

This study analyzes the pH of surface-sediment porewater (i.e. 2-3 cm below the water-sediment interface), and concentrations of CaCO3 and organic carbon (OC) in 1192 sediment cores from the northern South China Sea, in water depths ranging from 137 to 3702 m. This is the first study in the literature to analyze the large-scale spatial variability of deep-water surface-sediment pH over a large ocean basin. The data showed strong spatial variations in pH. The lowest pH values (<7.3) were observed south of Hainan Island, an area that is affected by summer upwelling and freshwater runoff from the Pearl and Red Rivers. Moderately low pH values (generally 7.3-7.5) occurred in two other areas: a submarine canyon, where sediments originated partly from the Pearl River and correspond to a paleo-delta front during the last glacial period; and southwest of Taiwan Island, where waters are affected by the northern branch of the Kuroshio intrusion current (KIC) and runoff from Taiwan rivers. The surface sediments with the highest pH (⩾7.5, and up to 8.3) were located in a fourth area, which corresponded to the western branch of the KIC where sediments have been intensively eroded by bottom currents. The pH of surface-sediment porewater was significantly linearly related to water depth, bottom-water temperature, and CaCO3 concentration (p < 0.05 for the whole sampling area). This study shows that the pH of surface-sediment porewater can be sensitive to characteristics of the overlying water column, and suggests that it will respond to global warming as changes in surface-ocean temperature and pH progressively reach deeper waters.

Go big or die out: Bifurcation and bimodality in submarine sediment flow behaviour

NASA Astrophysics Data System (ADS)

Talling, P.; Paull, C. K.; Lintern, G.; Gwiazda, R.; Cartigny, M.; Hughes Clarke, J. E.; Xu, J.; Clare, M. A.; Parsons, D. R.; Simmons, S.; Maier, K. L.; Gales, J. A.; Hage, S.; McGann, M.; Pope, E.; Rosenberger, K. J.; Stacey, C.; Barry, J.; Lundsten, E. M.; Anderson, K.; O'Reilly, T. C.; Chapplow, N.; Vendettuoli, D.

2017-12-01

Submarine flows of sediment (turbidity currents) flush globally significant volumes of sediment and organic carbon into deep-sea basins. These flows create the largest sediment accumulations on Earth, which hold valuable oil and gas reserves. These flows affect global carbon burial, how deep-sea ecosystems function, and pose a hazard to offshore infrastructure. Only river systems transport such large amounts of sediment across such long distances. However, there are remarkably few direct measurements from active submarine flows, which is a stark contrast to >1 million direct observations from rivers. Here we present unusually detailed information on frequency, power and runout distance of multiple submarine flows at two contrasting locations. The first data set comes from Monterey Canyon, offshore California, which is fed by littoral cells. The second site is a river-fed delta in Bute Inlet, British Columbia. In both cases, the timing and runout distance of submarine flows was documented using instruments on multiple moorings placed along the 50-km long flow pathway. A striking observation is that flow behaviour and runout is strongly bimodal in both locations. Flows tend to either dissipate rapidly, or runout through the entire mooring arrays. We thus test whether i) the character of short or long runout flows can be distinguished at the first mooring and ii) whether long and short runout flows have different triggers. It has been proposed that submarine flows have two modes of behaviour; either eroding and accelerating, or depositing and dissipating. These field data support such a view of bifurcation and bimodality in flow behaviour. However, some short runout flows resemble their longer runout cousins at the first mooring, and there is no clear relationship between flow trigger and runout. Thus, some flows reach a point where their character is no longer dependent on their initial trigger or initial structure, but on factors acting along the flow pathway.

KSC-06pd0473

NASA Image and Video Library

2006-03-11

KENNEDY SPACE CENTER, FLA. - A pair of mating bald eagles are spotted in their pine-tree nest near S.R. 3 on Kennedy Space Center. The nest, decades old, measures about 12 feet deep. The nest is one of a dozen active nests throughout the Merritt Island National Wildlife Refuge, which shares a boundary with the Center. Eagles' habitats are near lakes, rivers, marshes and seacoasts. Nests are masses of sticks, usually in the top of a tall tree. Even though they are fish eaters, bald eagles will take whatever prey is available and easiest to obtain. Bald eagles which live along the coast and on major lakes and rivers feed mainly on fish. Bald eagles fish in both fresh and salt water. Because of the energy expended during hunting, an eagle has to spend a lot of time resting quietly. It's estimated that only one out of eighteen attacks are successful. Photo credit: NASA/Jim Grossmann

Hyperpycnal plume-derived fans in the Santa Barbara Channel, California

USGS Publications Warehouse

Warrick, Jonathan A.; Simms, Alexander R.; Ritchie, Andy; Steel, Elisabeth; Dartnell, Pete; Conrad, James E.; Finlayson, David P.

2013-01-01

Hyperpycnal gravity currents rapidly transport sediment across shore from rivers to the continental shelf and deep sea. Although these geophysical processes are important sediment dispersal mechanisms, few distinct geomorphic features on the continental shelf can be attributed to hyperpycnal flows. Here we provide evidence of large depositional features derived from hyperpycnal plumes on the continental shelf of the northern Santa Barbara Channel, California, from the combination of new sonar, lidar, and seismic reflection data. These data reveal lobate fans directly offshore of the mouths of several watersheds known to produce hyperpycnal concentrations of suspended sediment. The fans occur on an upwardly concave section of the shelf where slopes decrease from 0.04 to 0.01, and the location of these fans is consistent with wave- and auto-suspending sediment gravity current theories. Thus, we provide the first documentation that the morphology of sediment deposits on the continental shelf can be dictated by river-generated hyperpycnal flows.

Comparison of different methods for estimating snowcover in forested, mountainous basins using LANDSAT (ERTS) images. [Washington and Santiam River, Oregon

NASA Technical Reports Server (NTRS)

Meier, M. J.; Evans, W. E.

1975-01-01

Snow-covered areas on LANDSAT (ERTS) images of the Santiam River basin, Oregon, and other basins in Washington were measured using several operators and methods. Seven methods were used: (1) Snowline tracing followed by measurement with planimeter, (2) mean snowline altitudes determined from many locations, (3) estimates in 2.5 x 2.5 km boxes of snow-covered area with reference to snow-free images, (4) single radiance-threshold level for entire basin, (5) radiance-threshold setting locally edited by reference to altitude contours and other images, (6) two-band color-sensitive extraction locally edited as in (5), and (7) digital (spectral) pattern recognition techniques. The seven methods are compared in regard to speed of measurement, precision, the ability to recognize snow in deep shadow or in trees, relative cost, and whether useful supplemental data are produced.

Observations of gas hydrates in marine sediments, offshore northern California

USGS Publications Warehouse

Brooks, J.M.; Field, M.E.; Kennicutt, M.C.

1991-01-01

Biogenic gas hydrates were recovered in shallow cores (< 6 m deep) from the Eel River basin in offshore northern California between 40??38??? and 40??56???N. The gas hydrates contained primarily methane (??13C = -57.6 to -69.1???) and occurred as dispersed crystals, small (2-20 mm) nodules, and layered bands within the sediment. These hydrates, recovered in sediment at water depths between 510 and 642 m, coincide nearly, but not exactly, with areas showing bottom-simulating reflectors (BSRs) on seismic-reflection records. This study confirms indirect geophysical and geologic observations that gas hydrates are present north of the Mendocino Fracture Zone in sediment of the Eel River basin but probably are absent to the south in the Point Arena basin. This discovery extends the confirmed sites of gas hydrates in the eastern Pacific region beyond the Peruvian and Central American margins to the northern California margin. ?? 1991.

Heavy metals in red crabs, Chaceon quinquedens, from the Gulf of Mexico.

PubMed

Perry, Harriet; Isphording, Wayne; Trigg, Christine; Riedel, Ralf

2015-12-30

The red crab, Chaceon quinquedens, is distributed in deep waters of the Gulf of Mexico (GOM) and is most abundant in an area associated with sediment deposition from the Mississippi River. Sediment geochemistry and biological and ecological traits of red crabs favor accumulation of contaminants. Red crabs, sediment, and bottom water samples were taken from three distinct geographic locations representing areas with differing exposure to contaminant laden effluents from the Mississippi River. Inductively coupled plasma spectrophotometry and atomic absorption spectrophotometry were employed to determine levels of heavy metals in red crab muscle tissue. Ion site partitioning was used to determine metal speciation in sediments. Red crabs showed evidence of heavy metal bioaccumulation in all sample areas with high variability in contaminant levels in individual crabs for some metals. Bioavailability of metals in sediment did not always result in accumulation in muscle tissue. Copyright © 2015 Elsevier Ltd. All rights reserved.

Potentiometric surface of the Floridan Aquifer, St. Johns River Water Management District and vicinity, Florida, May 1981

USGS Publications Warehouse

Schiner, George R.; Hayes, Eugene C.

1981-01-01

This map presents the potentiometric surface of the Floridan aquifer in the St. Johns River Water Management District and vicinity for May 1981. The Floridan aquifer is the principal source of potable water in the area. Water-level measurements were made in approximately 1,000 wells and at several springs. The potentiometric surface is shown mostly by 5-foot contour intervals. In the Fernandina Beach area 20 and 40-foot intervals are used to show a deep cone of depression. The potentiometric surface ranged from 122 feet above NGVD (National Geodetic Vertical Datum of 1929) in Polk County to 125 feet below NGVD in Nassau County. Water levels were at record lows in many counties due to lack of rainfall. Declines were as much as 10 feet and commonly 5 feet from the May 1980 levels. (USGS)

Fine-grained sediment storage conditioned by Large Woody Debris in a gravel-bed river

NASA Astrophysics Data System (ADS)

Skalak, K. J.; Narinesingh, P.; Pizzuto, J. E.

2006-05-01

The purposes of this study are 1) to determine the quantity of mud and sand stored in the channel margins and near-bank regions of South River, a steep gravel-bedded stream in western Virginia, and 2) to understand the geomorphic and hydrologic processes that control the erosion and deposition of these fine-grained deposits. The volume of storage in these deposits is equivalent to about 5-10 percent of the river's annual suspended sediment load. Sediment storage in the near-bank regions is a result of reduced velocity caused by the bank obstructions. Storage occurs in four different geomorphic settings: 1) long pooled sections caused by bedrock or old mill dams, 2) regions downstream of riffles in channel margins with LWD accumulations, 3) bank obstructions usually caused by trees, 4) side channel backwaters where flow separates around islands. Most storage occurs in regions downstream of riffles (approximately 44 percent of the total). Long pooled sections account for roughly 37 percent of the total storage, bank obstructions account for 13 percent, and backwaters account for roughly 6 percent. In approximately 17 km of river, there are 38 separate fine-grained deposits (total volume more than 1600 m3). On average, these deposits are about 35 cm deep, 20 m long, and 4 m wide. They average 30 percent mud, 68 percent sand, and 2 percent gravel. These deposits have been cored and analyzed for Hg, grain size, loss-on-ignition, and bomb radiocarbon. High Hg concentrations in fish tissue are an ongoing problem along South River, further motivating detailed study of these deposits.

Uplift history of the Sila Massif, southern Italy, deciphered from cosmogenic 10Be erosion rates and river longitudinal profile analysis

USGS Publications Warehouse

Olivetti, Valerio; Cyr, Andrew J.; Molin, Paola; Faccenna, Claudio; Granger, Darryl E.

2012-01-01

The Sila Massif in the Calabrian Arc (southern Italy) is a key site to study the response of a landscape to rock uplift. Here an uplift rate of ∼1 mm/yr has imparted a deep imprint on the Sila landscape recorded by a high-standing low-relief surface on top of the massif, deeply incised fluvial valleys along its flanks, and flights of marine terraces in the coastal belt. In this framework, we combined river longitudinal profile analysis with hillslope erosion rates calculated by 10Be content in modern fluvial sediments to reconstruct the long-term uplift history of the massif. Cosmogenic data show a large variation in erosion rates, marking two main domains. The samples collected in the high-standing low-relief surface atop Sila provide low erosion rates (from 0.09 ± 0.01 to 0.13 ± 0.01 mm/yr). Conversely, high values of erosion rate (up to 0.92 ± 0.08 mm/yr) characterize the incised fluvial valleys on the massif flanks. The analyzed river profiles exhibit a wide range of shapes diverging from the commonly accepted equilibrium concave-up form. Generally, the studied river profiles show two or, more frequently, three concave-up segments bounded by knickpoints and characterized by different values of concavity and steepness indices. The wide variation in cosmogenic erosion rates and the non-equilibrated river profiles indicate that the Sila landscape is in a transient state of disequilibrium in response to a strong and unsteady uplift not yet counterbalanced by erosion.

Bathymetrically controlled velocity-shear front at a tidal river confluence

NASA Astrophysics Data System (ADS)

Blain, Cheryl Ann; Mied, Richard P.; McKay, Paul; Chen, Wei; Rhea, W. Joseph

2015-08-01

Nonbuoyant front formation at the confluence of Nanjemoy Creek and the main Potomac River (MD) channel is examined. Terra satellite ASTER imagery reveals a sediment color front emerging from Nanjemoy Creek when the Potomac is near maximum ebb. Nearly contemporaneous ASTER and Landsat ETM+ imagery are used to extract surface velocities, which suggest a velocity shear front is collocated with the color front. In situ velocities (measured by RiverRay traverses near the Nanjemoy Creek mouth) confirm the shear front's presence. A finite-element simulation (using ADCIRC) replicates the observed velocity-shear front and is applied to decipher its physics. Three results emerge: (1) the velocity-shear front forms, confined to a shoal downstream of the creek-river confluence for most of the tidal cycle, (2) a simulation with a flat bottom in Nanjemoy Creek and Potomac River (i.e., no bathymetry variation) indicates the velocity-shear front never forms, hence the front cannot exist without the bathymetry, and (3) an additional simulation with a blocked-off Creek entrance demonstrates that while the magnitude of the velocity shear is largely unchanged without the creek, shear front formation is delayed in time. Without the Creek, there is no advection of the M6 tidal constituent (generated by nonlinear interaction of the flow with bottom friction) onto the shoals, only a locally generated contribution. A tidal phase difference between Nanjemoy and Potomac causes the ebbing Nanjemoy Creek waters to intrude into the Potomac as far south as its deep channel, and draw from a similar location in the Potomac during Nanjemoy flood.

Arctic Oases? - River Aufeis Maintain Perennial Groundwater Habitat in the Arctic

NASA Astrophysics Data System (ADS)

Huryn, A. D.; Gooseff, M. N.; Briggs, M. A.; Terry, N.; Kendrick, M.; Hendrickson, P. J.; Grunewald, E. D.

2017-12-01

Aufeis are massive accumulations of ice found along many arctic rivers, with aufeis on some Alaskan rivers covering 20+ km2 and attaining thicknesses of 5+ m. Although aufeis are prominent landscape features, understanding of their ecology is poor. We propose that aufeis function as summer oases by providing meltwater and nutrients to downstream habitats and winter oases due to insulating layers of ice that maintain below-ground freshwater habitat that would otherwise be frozen in regions of continuous permafrost. To gain information about the ecological roles of aufeis, we installed 50 1-m deep wells in a 1.5 km2aufeis field along the Kuparuk River, an arctic tundra river in Alaska. We assessed the predictions that aufeis provide perennially-unfrozen, below-ground habitat for a specialized invertebrate community while functioning as hot spots for nutrient regeneration. Surface geophysical measurements made during the time of maximum ice thickness in 2017 indicated most of the Kuparuk feature was underlain by several meters of shallow frozen cobbles that were further underlain by a 10 m thick+ zone of thawed material. Ground penetrating radar and surface nuclear magnetic resonance data indicated several spatially-discrete thawed preferential flow zones through the shallow frozen sediment layer that may result from groundwater upwelling observed flowing through fractures in the icepack. Freshwater invertebrates sampled from the wells represent a rich community consisting of flatworms, annelids, copepods, ostracods, chironomids (Krenosmittia, Trichotanypus) and stoneflies. Although the potential for below-ground NH4+ and NO3-regeneration was indicated, analyses were complicated bya surprisingly strong and dynamic coupling of surface and below-ground water.

Late Cenozoic fluvial successions in northern and western India: an overview and synthesis

NASA Astrophysics Data System (ADS)

Sinha, R.; Kumar, R.; Sinha, S.; Tandon, S. K.; Gibling, M. R.

2007-11-01

Late Cenozoic fluvial successions are widespread in India. They include the deposits of the Siwalik basin which represent the accumulations of the ancient river systems of the Himalayan foreland basin. Palaeomagnetic studies reveal that fluvial architecture and styles of deposition were controlled by Himalayan tectonics as well as by major climatic fluctuations during the long (∼13 Ma) span of formation. The Indo-Gangetic plains form the world's most extensive Quaternary alluvial plains, and display spatially variable controls on sedimentation: Himalayan tectonics in the frontal parts, climate in the middle reaches, and eustasy in the lower reaches close to the Ganga-Brahmaputra delta. Climatic effects were mediated by strong fluctuations in the SW Indian Monsoon, and Himalayan rivers occupy deep valleys in the western Ganga plains where stream power is high, cut in part during early Holocene monsoon intensification; the broad interfluves record the simultaneous aggradation of plains-fed rivers since ∼100 ka. The eastward increase in precipitation across the Ganga Plains results in rivers with low stream power and a very high sediment flux, resulting in an aggradational mode and little incision. The river deposits of semi-arid to arid western India form important archives of Quaternary climate change through their intercalation with the eolian deposits of the Thar Desert. Although the synthesis documents strong variability-both spatial and temporal-in fluvial stratigraphy, climatic events such as the decline in precipitation during the Last Glacial Maximum and monsoon intensification in the early Holocene have influenced fluvial dynamics throughout the region.

Spatial and Temporal Distributions of Carbonate Saturation State on the Mississippi River Dominated Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Huang, W. J.; Cai, W. J.; Wang, Y.; Hu, X.

2016-02-01

Carbonate saturation state (ΩAr) serves as an index of ocean acidification; however, its variation on river-dominated continental shelves remains unclear. Samples of total alkalinity (TA), dissolved inorganic carbon (DIC), and nutrients were taken from nine cruises on the Mississippi and Atchafalaya River dominated continental shelf during 2006 to 2010. The distributions of TA and DIC on sea surface generally follow salinity distributions, i.e. low on the inner shelf and high on the outer shelf. The riverine calcium concentration was considered to calculate ΩAr and the result showed high ΩAr (4 to 6) along the axis of the river plume trajectory, moderate ( 4) on the surface open gulf, and low (< 3) in the deep gulf. Strong seasonal variation of ΩAr was observed in the river endmembers, high in spring and low in winter. The ΩAr variation was dominated by mixing when salinities < 18. In waters of higher salinities, deficits of DIC from the conservative mixing lines were positively correlated to deficits of NO3 and the slope of regression line was close to the Redfield ratio after removing data affected by unbalanced Si and N. The fact that ΩAr was highly correlated to ΔDIC suggests that ΩAr was dominated by biological activity. Finally, model simulations suggest that the effect of increasing riverine TA (increasing ΩAr in low salinities zone) and the effect of decreasing riverine nitrate flux (decreasing ΩAr in middle-to-high salinities zone) on ΩAr might compensate each other in this study area.

Stream water quality in coal mined areas of the lower Cheat River Basin, West Virginia and Pennsylvania, during low-flow conditions, July 1997

USGS Publications Warehouse

Williams, Donald R.; Clark, Mary E.; Brown, Juliane B.

1999-01-01

IntroductionThe Cheat River Basin is in the Allegheny Plateau and Allegheny Mountain Sections of the Appalachian Plateau Physiographic Province (Fenneman, 1946) and is almost entirely within the state of West Virginia. The Cheat River drains an area of 1,422 square miles in Randolph, Tucker, Preston, and Monongalia Counties in West Virginia and Fayette County in Pennsylvania. From its headwaters in Randolph County, W.Va., the Cheat River flows 157 miles north to the Pennsylvania state line, where it enters the Monongahela River. The Cheat River drainage comprises approximately 19 percent of the total Monongahela River Basin. The Cheat River and streams within the Cheat River Basin are characterized by steep gradients, rock channels, and high flow velocities that have created a thriving white-water rafting industry for the area. The headwaters of the Cheat River contain some of the most pristine and aesthetic streams in West Virginia. The attraction to the area, particularly the lower part of the Cheat River Basin (the lower 412 square miles of the basin), has been suppressed because of poor water quality. The economy of the Lower Cheat River Basin has been dominated by coal mining over many decades. As a result, many abandoned deep and surface mines discharge untreated acid mine drainage (AMD), which degrades water quality, into the Cheat River and many of its tributary streams. Approximately 60 regulated mine-related discharges (West Virginia Department of Environmental Protection, 1996) and 185 abandoned mine sites (U.S. Office of Surface Mining, 1998) discharge treated and untreated AMD into the Cheat River and its tributaries.The West Virginia Department of Environmental Protection (WVDEP) Office of Abandoned Mine Lands and Reclamation (AML&R) has recently completed several AMD reclamation projects throughout the Cheat River Basin that have collectively improved the mainstem water quality. The AML&R office is currently involved in acquiring grant funds and designing treatment facilities for several additional AMD sites that adversely affect the Cheat River and its tributaries. To obtain the baseline water-quality information necessary to evaluate instream treatment and alternative methods for remediating AMD and its effects, the U.S. Geological Survey (USGS), in cooperation with the WVDEP, collected stream water samples at 111 sites throughout the Lower Cheat River Basin during low-flow conditions from July 16-18, 1997. The data also will provide information on stream water quality in areas affected by AMD and thus would point to priority areas of focus, such as the sources of the AMD. This report presents the results of analyses of the samples collected in July 1997 and describes a process for ranking of stream water-quality degradation as a guide to water-resource managers considering AMD remediation activities.

The Morphometry of Lake Palmas, a Deep Natural Lake in Brazil

PubMed Central

Barroso, Gilberto F.; Gonçalves, Monica A.; Garcia, Fábio da C.

2014-01-01

Lake Palmas (A = 10.3km2) is located in the Lower Doce River Valley (LDRV), on the southeastern coast of Brazil. The Lake District of the LDRV includes 90 lakes, whose basic geomorphology is associated with the alluvial valleys of the Barreiras Formation (Cenozoic, Neogene) and with the Holocene coastal plain. This study aimed to investigate the relationship of morphometry and thermal pattern of a LDRV deep lake, Lake Palmas. A bathymetric survey carried out in 2011 and the analysis of hydrographic and wind data with a geographic information system allowed the calculation of several metrics of lake morphometry. The vertical profiling of physical and chemical variables in the water column during the wet/warm and dry/mild cold seasons of 2011 to 2013 has furnished a better understanding of the influence of the lake morphometry on its structure and function. The overdeepened basin has a subrectangular elongated shape and is aligned in a NW-SE direction in an alluvial valley with a maximum depth (Zmax) of 50.7m, a volume of 2.2×108 m3 (0.22km3) and a mean depth (Zmv) of 21.4m. These metrics suggest Lake Palmas as the deepest natural lake in Brazil. Water column profiling has indicated strong physical and chemical stratification during the wet/warm season, with a hypoxic/anoxic layer occupying one-half of the lake volume. The warm monomictic pattern of Lake Palmas, which is in an accordance to deep tropical lakes, is determined by water column mixing during the dry and mild cold season, especially under the influence of a high effective fetch associated with the incidence of cold fronts. Lake Palmas has a very long theoretical retention time, with a mean of 19.4 years. The changes observed in the hydrological flows of the tributary rivers may disturb the ecological resilience of Lake Palmas. PMID:25406062

The Baltic Sea natural long-term variability of salinity

NASA Astrophysics Data System (ADS)

Schimanke, Semjon; Markus Meier, H. E.

2015-04-01

The Baltic Sea is one of the largest brackish sea areas of the world. The sensitive state of the Baltic Sea is sustained by a fresh-water surplus by river discharge and precipitation on one hand as well as inflows of highly saline and oxygen-rich water masses from the North Sea on the other. Major inflows which are crucial for the renewal of the deep water occur very intermittent with a mean frequency of approximately one per year. Stagnation periods (periods without major inflows) lead for instance to a reduction of oxygen concentration in the deep Baltic Sea spreading hypoxic conditions. Depending on the amount of salt water inflow and fresh-water supply the deep water salinity of the Baltic Sea varies between 11 to 14 PSU on the decadal scale. The goal of this study is to understand the contribution of different driving factors for the decadal to multi-decadal variability of salinity in the Baltic Sea. Continuous measurement series of salinity exist from the 1950 but are not sufficiently long for the investigation of long-term fluctuations. Therefore, a climate simulation of more than 800 years has been carried out with the Rossby Center Ocean model (RCO). RCO is a biogeochemical regional climate model which covers the entire Baltic Sea. It is driven with atmospheric data dynamical downscaled from a GCM mimicking natural climate variability. The analysis focus on the role of variations in river discharge and precipitation, changes in wind speed and direction, fluctuations in temperature and shifts in large scale pressure patterns (e.g. NAO). Hereby, the length of the simulation will allow to identify mechanisms working on decadal to multi-decadal time scales. Moreover, it will be discussed how likely long stagnation periods are under natural climate variability and if the observed exceptional long stagnation period between 1983-1993 might be related to beginning climate change.

Riverbank Collapse on the lower Murray River: recent phenomenon or long-term geomorphic process?

NASA Astrophysics Data System (ADS)

De Carli, E.; Hubble, T.; Jaksa, M.; Clarke, S. L.; Airey, D.; O'Toole, J.; Carpenter, G.

2013-12-01

The lower Murray River connects the Murray-Darling River Basin to the Southern Ocean and drains 14% of Australia's landmass. During the Millennium Drought (1997-2011) record low inflows for the Basin were recorded and the lower Murray River received only 19% of its long-term average inflow for 2008-2009, causing the pool-level in the lowermost reaches near Goolwa to fall 1 m below sea level. This event triggered widespread mass failure in the alluvial river banks and ground subsidence in some river-adjacent floodplain deposits between Blanchetown and Lake Alexandrina. Multi-beam bathymetry, sediment core and geotechnical data are presented for a number of sites investigated between Mannum and White Sands. Interpretation of this data indicates three different bank-failure slide morphologies present in the banks and adjacent channel. Type 1, ';recent' (2009-2011) deep-seated rotational slumps characterised by distinct, sharply-defined failure scars and associated debris fields of angular blocks shed from the failure site. Type 2, ';relatively-recent' shallow planar-failures, with less well-defined smoother failure scars and associated debris fields of smoothed or rounded blocks and pinnacles. Type 3, ';relatively-old' shallow planar-failures characterised by subdued relief slump scars that do not present an associated debris field. It is suspected that successive floods or high-flow events progressively erode and redistribute material, smoothing the landslide scars and redistributing the slide-debris deposits. Bank-failure and the delivery of material from the slides into the channel is interpreted as an ongoing and long-term geomorphic characteristic of the lower Murray River, rather than a new phenomenon that occurred as a response to unusually low river levels during the Millennium Drought. The larger size and rotational style of the recent Type 1 failures is most likely to be a consequence of the drought and anthropogenic modifications of the river channel and banks, e.g. construction of the barrages preventing seawater ingress into the channel and small levee and embankment construction. Figure 1) Location of the lower Murray River (red outline) within the Murray-Darling Basin, Australia. Figure 2) Multibeam bathymetry of Woodlane Reserve, Mypolonga, South Australia. Note the different bank-failure slide morphologies, Types 1, 2 & 3.

Mississippi River Delta, Louisiana as seen from STS-62

NASA Image and Video Library

1994-03-05

STS062-85-021 (4-18 March 1994) --- The Mississippi River is the largest river system in North America. Its delta is a typical example of the bird's foot class of river deltas. It drains nearly 3 1/2 million square kilometers of real estate and is estimated to carry 2.4 billion kilograms (more than 500 million tons) of sand, silt, and clay to the Gulf of Mexico annually. Most of this sediment is deposited as a delta at the mouth of the river where the velocity of the river water is slowed and its ability to transport sediment is accordingly diminished. Continued deposition at such a site progrades the delta or extends it seaward into the Gulf as much as 150 meters each year until such time as a flooding episode finds a shorter more efficient channel to deliver sediment-laden river waters to the Gulf. At that time the old delta is abandoned and the river begins to build a new delta. In time, compaction of the sediment in the old delta causes it to subside forming first marshes, then bays. This and the modifying effects of coastal waves eventually allow the sea to reclaim much of the temporary land area of the delta. This sequence has repeated itself over and over again at the Mississippi Delta. In this photograph, the present day active Balize delta is shown. According to NASA scientists it is the youngest of the recent delta lobes having begun its seaward pro-gradation only some 600 - 800 years ago. The main channel of the river is 2 kilometers wide and 30 - 40 meters deep. Natural levees here are almost 1 kilometer wide and 3 to 4 meters above sea level. Along the active distributaries of the lower delta, natural levees are less than 100 meters wide and generally less than 0.5 meters above sea level. The bird's foot appearance of deltas such as this is characteristic of low coastal energy conditions - that is, low levels of tidal fluctuation and generally low wave energy. The interdistributary bays are extremely shallow, usually less than a few meters, and contain brackish to normal marine waters except during times of flooding, when fresh water fills the bays. Sedimentation within the bays is very slow, occurring only during flood periods. Along the west side of the river, a highway has been built southeastward to Venice.

[Crossing borders. The motivation of extreme sportsmen].

PubMed

Opaschowski, H W

2005-08-01

In his article "Crossing borders -- the motivation of extreme sportsmen" the author gets systematically to the bottom of the question of why extreme sportsmen voluntarily take risks and endanger themselves. Within the scope of a representative sampling 217 extreme sportsmen -- from the fields of mountain biking, trekking and free climbing, canoyning, river rafting and deep sea diving, paragliding, parachuting, bungee jumping and survival training -- give information about their personal motives. What fascinates them? The attraction of risk? The search for sensation? Or the drop out of everyday life? And what comes afterwards? Does in the end the whole life become an extreme sport? Fact is: they live extremely, because they want to move beyond well-trodden paths. To escape the boredom of everyday life they are searching for the kick, the thrill, the no-limit experience. It's about calculated risk between altitude flight and deep sea adventure.

DEPOSITIONAL RELATIONS OF UMPQUA AND TYEE FORMATIONS (EOCENE), SOUTHWESTERN OREGON.

USGS Publications Warehouse

Molenaar, C.M.

1985-01-01

The Umpqua Formation (as herein restricted) consists of as much as 10,000 ft of mudstone, sandstone, and conglomerate of nonmarine to deep marine origin. A basaltic basement that underlies the sedimentary rocks in most of the area and was formerly included in the Umpqua is herein considered a separate unit and assigned to the Siletz River Volcanics. A proposal to subdivide the Umpqua into three unconformity-bounded formations in the area west of Roseburg, Oregon, is not recognized in this report because of questionable correlations and limited extent of some units. The Tyee Formation, which conformably overlies the Umpqua, is a predominantly sandstone unit about 6,000 ft thick, deposited in environments ranging from shallow marine and nonmarine deltaic on the south, to slope and deep marine basinal to the north. Deposition across the Umpqua-Tyee boundary contact represents a change in tectonic setting. Refs.

Isotopic Responses to Processes Related to Oxygen Cycling During Diel Studies in the San Joaquin River, California

NASA Astrophysics Data System (ADS)

Silva, S. R.; Young, M. B.; Kendall, C.; Dahlgren, R. A.; Stringfellow, W. T.

2008-12-01

Episodic conditions of low dissolved oxygen (DO) occurring in the San Joaquin River deep water shipping channel (DWSC) at Stockton, California inhibit salmon migration during late summer and early fall. As part of a CALFED study to determine the sources of organic matter and nutrients related to the low DO problem, four diel studies were undertaken: two at the DWSC in 2006 and 2007 and two about 40 miles upstream at Crows Landing in 2005 and 2007. The purpose of the diel studies was to gain a better understanding of the transient processes controlling oxygen concentrations and to compare the range of diel variations of various isotopic measurements with those collected on a less frequent basis. The DWSC is dredged to about 40 feet deep and is tidally influenced. The river at Crows Landing is about 5 feet deep and well above tidal influence. Crows Landing was therefore used for comparison with the DWSC as a hydrologically less complicated portion of the river that has not been dredged. Samples were collected at two hour intervals from a one meter depth at Crows Landing. Values of d18O-DO, DO concentrations and pH showed a strong diel response linked to photosynthesis and the effects of bacterial respiration. The d13C of POM (composed mostly of algae) increased at night as expected while the C:N ratio of POM unexpectedly decreases, possibly due to an increased presence of zooplankton at night. Opposing trends of d15N and d18O of nitrate unrelated to a diurnal cycle suggest that source mixing was largely responsible for nitrate composition and concentration through much of the study. Samples were collected at two hour intervals from 1, 5, and 8 meter depths at Rough and Ready Island in the DWSC. Isotope and concentration data showed a distinct diurnal photosynthetic response at the 1 meter depth only. The 2007 DIC and POM isotopic data suggested that nitrification was significantly responsible for oxygen consumption through the duration of the study. The particularly low flow conditions in 2007 increased residence time and allowed water temperatures to rise accentuating the conditions for low DO concentrations. Compared to Crows Landing, where DO concentrations were near and above air saturation, DO concentrations at the DWSC were almost all below saturation reflecting the greater role of respiration and nitrification in the deeper, slower moving water where photosynthesis is restricted by light penetration and organic debris can accumulate. The diel studies illustrate that isotopes of DO, DIC, nitrate and POM provide unique information about the complex behavior of the DWSC. Furthermore, these data illustrate that sampling at a single depth or at a single time of day may not capture an accurate picture of conditions related to oxygen cycling.

Assessment of chevron dikes for the enhancement of physical-aquatic habitat within the Middle Mississippi River, USA

NASA Astrophysics Data System (ADS)

Remo, Jonathan W. F.; Khanal, Anish; Pinter, Nicholas

2013-09-01

Blunt-nosed chevron dikes, a new invention now being widely constructed on the Middle Mississippi River (MMR), have been justified as a tool for enhancing physical-aquatic habitat. Chevron dikes were initially designed to concentrate flow, induce channel scour, and thus facilitate river navigation. More recently, these structures have been justified, in part, for promoting habitat heterogeneity. The ability of chevrons to create and diversify physical-aquatic habitat, however, has not been empirically evaluated. To assess the ability of chevrons to create and diversify physical-aquatic habitat, we compiled hydrologic and geospatial data for three channel reference conditions along a 2.0 km (∼140 ha) reach of the MMR where three chevrons were constructed in late 2007. We used the hydrologic and hydraulic data to construct detailed 2-D hydrodynamic models for three reference condition: historic (circa 1890), pre-chevron, and post-chevron channel conditions. These models documented changes in depths and flow dynamics for a wide range of in-channel discharges. Depth-velocity habitat classes were used to assess change in physical-aquatic habitat patches and spatial statistical tools in order to evaluate the reach-scale habitat patch diversity. Comparisons of pre- and post-chevron conditions revealed increases in deep to very deep (>3.0 m) areas of slow moving (<0.6 m/s) water downstream of these structures under emergent flow conditions (⩽1.5 × mean annual flow [MAF]). Chevron construction added up to 7.6 ha of potential over-wintering habitat (deep [>3.0 m], low velocity [<0.6 m/s]). Chevron construction also created some (0.8-3.8 ha) shallow-water habitat (0-1.5 m depth with a 0-0.6 m/s velocity) for flows ⩽2.0 × MAF and contributed to an 8-35% increase in physical-aquatic-habitat diversity compared to pre-chevron channel conditions. However, modeling of the historic reference condition (less engineered channel, circa 1890) revealed that the historical physical-aquatic-habitat mosaic consisted of a wider and shallower channel with: 45-390% more shallow-water habitat (2.4-11.0 ha) and 22-83% more physical-aquatic-habitat diversity, but little over-wintering habitat (<0.4 ha). Thus, while chevron construction increased over-wintering habitat, shallow-water habitat, and physical-aquatic-habitat diversity relative to the pre-chevron channel condition, these types of physical-aquatic habitat are different from what was historically found along this reach. Constructing chevrons dikes, or other dike-like structures in the river channel, can change the physical-aquatic habitat patch mosaic and likely contribute to small increases in physical-aquatic-habitat heterogeneity. However, differences in the types, quantity, and diversity of physical-aquatic-habitat patches created by chevron dikes in comparison to the physical-aquatic-habitat patch mosaic of historic channel underscore the need for additional research to determine which physical-aquatic-habitat patches are critical for the recovery of endangered or threatened aquatic organisms.

Upper Cretaceous Shannon Sandstone Reservoirs, Powder River Basin, Wyoming: Evidence for organic acid diagenesis

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

Hansley, P.L.; Nuccio, V.F.

Comparison of the petrology of shallow and deep oil reservoirs in the Upper Cretaceous Shannon Sandstone Beds of the Steele Member of the Cody Shale strongly suggests that organic acids have had a more significant impact on the diagenetic alteration of aluminosilicate grains and carbonate cements in the deep reservoirs than in the shallow reservoirs. In shallow reservoirs, detrital grains exhibit minor dissolution, sparse and small overgrowths, and secondary porosity created by dissolution of early calcite cement. However, deeper sandstones are characterized by extensive dissolution of detrital K-feldspar and detrital glauconite grains, and precipitation of abundant, large quartz and feldsparmore » overgrowths. Throughout the Shannon and Steele, dissolution of glauconite and degradation of kerogen were probably aided by clay mineral/organic catalysis, which caused simultaneous reduction of iron and oxidation of kerogen. This process resulted in release of ferrous iron and organic acids and was promoted in the deep reservoirs by higher formation temperatures accounting for more extensive dissolution of aluminosilicate grains. Carbonic acid produced from the dissolution of early calcite cement, decarboxylation of organic matter, and influx of meteoric water after Laramide uplift produced additional dissolution of cements and grains. Dissolution by organic acids and complexing by organic acid anions, however, best explain the intensity of diagenesis and absence of dissolution products in secondary pores and on etched surfaces of framework grains in deep reservoirs.« less

Chlorine-36 tracing of salinity sources in the Dry Valleys of Victoria Land, Antarctica

NASA Astrophysics Data System (ADS)

Carlson, Catherine A.; Phillips, Fred M.; Elmore, David; Bentley, Harold W.

1990-02-01

Chlorine-36 was used to trace the origins of salts in six saline lakes in the Dry Valleys of Southern Victoria Land, Antarctica. Characteristic 36Cl signatures were estimated for the various potential chloride sources, which include atmospheric deposition, rock weathering, seawater, and deep ground water. 36Cl /Cl ratios were measured in natural waters and salts from the Dry Valleys. Dilute lake waters (Cl - < 100 mg/l) were found to have 36Cl /Cl ratios in the range 100 × 10 -15 to 1,700 × 10 -15, whereas saline waters (Cl - > 1000 mg/l) had ratios in the range 9 × 10 -15 to 40 × 10 -15. Simple mixing models were employed to quantify the relative contributions of the various chloride sources to Lake Vanda and Don Juan Pond. These results show that Lake Vanda has received its chloride from both deep ground water and the Onyx River. Don Juan Pond has received nearly all its chloride from deep ground water, probably ultimately from rock-water interaction. Deep ground water is the principal source of chloride to the lakes of Wright Valley. However, preliminary data suggest that marine-derived salts or relict sea water may be a significant source of chloride to the lakes of Taylor Valley, implying a possible recent marine invasion that did not affect Wright Valley.

Hydrogeologic Characteristics of the St. Croix River Basin, Minnesota and Wisconsin: Implications for the Susceptibility of Ground Water to Potential Contamination

USGS Publications Warehouse

Juckem, Paul F.

2007-01-01

Population growth in the St. Croix River Basin in Minnesota and Wisconsin has intensified concerns of county resource managers and the National Park Service, which is charged with protecting the St. Croix National Scenic Riverway, about the potential for ground-water contamination in the basin. This report describes a previously developed method that was adapted to illustrate potential ground-water-contamination susceptibility in the St. Croix River Basin. The report also gives an estimate of ground-water-residence time and surface-water/ground-water interaction as related to natural attenuation and movement of contaminants in five tributary basins. A ground-water-contamination-susceptibility map was adapted from a state-wide map of Wisconsin to the St. Croix River Basin by use of well-driller construction records and regional maps of aquifer properties in Minnesota and Wisconsin. Measures of various subsurface properties were combined to generate a spatial index of susceptibility. The subjective index method developed for the State of Wisconsin by Schmidt (1987) was not derived from analyses of water-quality data or physical processes. Nonetheless, it was adapted for this report to furnish a seamless map across state boundaries that would be familiar to many resource managers. Following this method, areas most susceptible to contamination appear to have coarse-grained sediments (sands or gravels) and shallow water tables or are underlain by carbonate-bedrock aquifers. The least susceptible areas appear to have fine-grained sediments and deep water tables. If an aquifer becomes contaminated, the ground-water-residence time can affect potential natural attenuation along the ground-water-flow path. Mean basin ground-water-residence times were computed for the Apple, Kettle, Kinnickinnic, Snake and Sunrise River Basins, which are tributary basins to the St. Croix Basin, by use of average aquifer properties of saturated thickness, porosity, and recharge rates. The Apple River Basin had the shortest mean ground-water-residence times (20-120 years), owing largely to the moderate saturated thickness and high recharge rate in the basin. The Kinnickinnic and Sunrise River Basins had the longest mean residence times (60-350 and 70-390 years, respectively) chiefly because of the relatively large saturated thickness of the basins. Owing to limitations of the residence-time calculations, actual ground-water-residence times will vary around the mean values within each basin and may range from days or weeks in karst carbonate aquifers to millennia in deep confined sandstone aquifers. Areas of relatively short residence time (less than the median residence time in each basin) were identified by use of ground-water-flow models for each of the five tributary basins. Results of simulations show that these areas, in which contaminants may have relatively less time for natural attenuation along the short flow paths, generally occur near streams and rivers where ground water discharges to the surface. Finally, the ground-water-flow models were used to simulate ground-water/surface-water interaction in the five tributary basins. Results of simulations show that some lakes and reservoirs leak surface water into the ground-water-flow system on their downgradient side, where the surface-water outflow has been restricted by a dam or a naturally constricted outlet. These locations are noteworthy because contaminated surface waters could potentially enter the ground-water-flow system at these locations.

Magnetic Properties of a Fluvial Chronosequence From the Eastern Wind River Range, Wyoming

NASA Astrophysics Data System (ADS)

Quinton, E. E.; Dahms, D. E.; Geiss, C. E.

2010-12-01

In order to constrain the rate of magnetic enhancement in glacial fluvial sediments, we sampled modern soils from eight fluvial terraces in the East Wind River Range in Wyoming. Soil profiles up to 1.2 meters deep were described in the field and sampled in five cm intervals from a series of hand-dug pits or natural river-bank exposure. The age of the studied profiles are estimated to range from >600 ka to modern. They include Sacagawea Ridge, Bull Lake and Pinedale-age fluvial terraces as well as one Holocene profile. To characterize changes in magnetic properties we measured low-field magnetic susceptibility, anhysteretic remanent magnetization, isothermal remanent magnetization and S-ratios for all, and hysteresis loops for a selected sub-set of samples. Our measurements show no clear trend in magnetic enhancement with estimated soil age. The observed lack of magnetic enhancement in the older soils may be due to long-term deflation, which continuously strips off the magnetically enhanced topsoil. It is also possible that the main pedogenic processes, such as the development of well-expressed calcic horizons destroy or mask the effects of long-term magnetic enhancement.

The rapids and the pools - Grand Canyon: Chapter D in The Colorado River region and John Wesley Powell (Professional Paper 669)

USGS Publications Warehouse

Leopold, Luna Bergere

1969-01-01

Through the Grand Canyon the Colorado drops in elevation about 2,200 feet in 280 miles; most of this drop occurs in rapids that account for only 10 percent of the distance. Despite the importance of rapids, there are no waterfalls. Depth measurements made at 1/10-mile intervals show that the bed profile is highly irregular, but the apparent randomness masks an organized alternation of deeps and shallows. Measurement of the age of a lava flow that once blocked the canyon near Toroweap shows that no appreciable deepening of the canyon has taken place during the last million years. It is reasoned that the river has had both the time and the ability to eliminate the rapids. The long-continued existence and the relative straightness of the longitudinal profile indicate that the river maintains a state of quasi-equilibrium which provides the hydraulic requirements for carrying the debris load brought in from upstream without continued erosion of the canyon bed. The maintenance of the alternating pools and rapids seems to be a necessary part of this poised or equilibrium condition.

A modeling assessment of the thermal regime for an urban sport fishery

USGS Publications Warehouse

Bartholow, John M.

1991-01-01

Water temperature is almost certainly a limiting factor in the maintenance of a self-sustaining rainbow trout (Oncorhynchus mykiss, formerly Salmo gairdneri) and brown trout (Salmo trutta) fishery in the lower reaches of the Cache la Poudre River near Fort Collins, Colorado, USA. Irrigation diversions dewater portions of the river, but cold reservoir releases moderate water temperatures during some periods. The US Fish and Wildlife Service’s Stream Network Temperature Model (SNTEMP) was applied to a 31-km segment of the river using readily available stream geometry and hydrological and meteorological data. The calibrated model produced satisfactory water temperature predictions (R2=0.88,P3/sec would be needed to maintain suitable summer temperatures throughout most of the study area. Such flows would be especially beneficial during weekends when current irrigation patterns reduce flows. The model indicated that increasing the riparian shade would result in little improvement in water temperatures but that decreasing the stream width would result in significant temperature reductions. Introduction of a more thermally tolerant redband trout (Oncorhynchus sp.), or smallmouth bass (Micropterus dolomieui) might prove beneficial to the fishery. Construction of deep pools for thermal refugia might also be helpful.

River of Sand

NASA Image and Video Library

2016-09-21

A dominant driver of surface processes on Mars today is aeolian (wind) activity. In many cases, sediment from this activity is trapped in low-lying areas, such as craters. Aeolian features in the form of dunes and ripples can occur in many places on Mars depending upon regional wind regimes. The Cerberus Fossae are a series of discontinuous fissures along dusty plains in the southeastern region of Elysium Planitia. This rift zone is thought to be the result of combined volcano-tectonic processes. Dark sediment has accumulated in areas along the floor of these fissures as well as inactive ripple-like aeolian bedforms known as "transverse aeolian ridges" (TAR). Viewed through HiRISE infrared color, the basaltic sand lining the fissures' floor stands out as deep blue against the light-toned dust covering the region. This, along with the linearity of the fissures and the wave-like appearance of the TAR, give the viewer an impression of a river cutting through the Martian plains. However, this river of sand does not appear to be flowing. Analyses of annual monitoring images of this region have not detected aeolian activity in the form of ripple migration thus far. http://photojournal.jpl.nasa.gov/catalog/PIA21063

Ionic composition and greenhouse gases evaluation in Tietê River sediment and mud landfill

NASA Astrophysics Data System (ADS)

La-Scalea, M. A.; Fornaro, A.; Abreu, E. L.; Mendonça, C. A.

2012-04-01

There are 39 cities composing the Metropolitan Area of São Paulo (MASP) which has grown seven times during the last sixty years, reaching, in 2011, 19.3 million inhabitants. This fact associated with a strong industrial development provoked, among other consequences, a disordered urbanization along the most important river of the region: Tietê. About 100 Km of its 1,150 Km full extension crosses MASP and, during the 60's, Marginal Tietê roadway was constructed, occupying the river banks as access routes. Tietê River was straightened and several landfills were created with its deposit (sediment and mud). EACH-USP (46.50 W, 23.48 S) lies nowadays in one of these areas, where this work has been developed. Therefore, the goal is to evaluate the chemical composition (ionic and gases) and its variability in function of the depth levels using three wells, from 0.60 to 9.0 m of depth. The wells were perforated in September 2011, end of the dry weather. Each well owns a homemade multiport sampling device (HMSD), being possible to push gas and/or water up from 15 available ports. The gases measurements were carried out using a GEM-2000 plus (Landtec) portable analyzer. Aqueous samples containing solid material were taken at each level depth from ports of the HMSD. However, no water was found in some levels. All samples were kept cooled until analysis procedures. After decantation of the solid material, the supernatant liquid was divided in two portions, being its conductivity (Micronal conductimeter) and pH (pH-meter Metrohm 654 with combined glass electrode) measured with the former and ionic analysis with the latter, in which all samples were filtered (Millex 0.22 micrometer pores) before each ionic chromatographic analysis, using Metrohm 850 System, for the ions: sodium, ammonium, potassium, calcium, magnesium, chloride, nitrate and sulfate. The first sampling stage was carried out during November and December 2011 in the beginning of rainy season in the mid Spring. From all the analysis performed, a large variability of the results may be observed for both gases and ionic composition not only among the wells, but also among the different depth levels. Vertically, one of the wells (W2) showed the same percentage of gases, methane 55% and carbon dioxide 45%, at all depth levels, while the other two wells (W1 and W3) presented these gases percentages only under 5.0 m deep. Concerning oxygen, 25% of this gas was detected at 1.0 m under the surface in W1 and W3. In relation to aqueous samples, the most acidity was observed near the surface (0.60 m deep, W1), pH 4.65, while pH 7.88 was obtained under 5.0 m deep (W3). For ionic concentrations a large range was observed considering all wells, being the lowest values for sulfate, from 0.60 to 20 mg/l, and the highest values for ammonium, between 14 and 53 mg/l. These results variability can be associated to the different soil composition layers, as well as to the biodegradation process and the time confinement of the river material deposit.

Identification of new deep sea sinuous channels in the eastern Arabian Sea.

PubMed

Mishra, Ravi; Pandey, D K; Ramesh, Prerna; Clift, Peter D

2016-01-01

Deep sea channel systems are recognized in most submarine fans worldwide as well as in the geological record. The Indus Fan is the second largest modern submarine fan, having a well-developed active canyon and deep sea channel system. Previous studies from the upper Indus Fan have reported several active channel systems. In the present study, deep sea channel systems were identified within the middle Indus Fan using high resolution multibeam bathymetric data. Prominent morphological features within the survey block include the Raman Seamount and Laxmi Ridge. The origin of the newly discovered channels in the middle fan has been inferred using medium resolution satellite bathymetry data. Interpretation of new data shows that the highly sinuous deep sea channel systems also extend to the east of Laxmi Ridge, as well as to the west of Laxmi Ridge, as previously reported. A decrease in sinuosity southward can be attributed to the morphological constraints imposed by the elevated features. These findings have significance in determining the pathways for active sediment transport systems, as well as their source characterization. The geometry suggests a series of punctuated avulsion events leading to the present array of disconnected channels. Such channels have affected the Laxmi Basin since the Pliocene and are responsible for reworking older fan sediments, resulting in loss of the original erosional signature supplied from the river mouth. This implies that distal fan sediments have experienced significant signal shredding and may not represent the erosion and weathering conditions within the onshore basin at the time of sedimentation.

Lake Sarez, Tajikistan

NASA Technical Reports Server (NTRS)

2002-01-01

Lake Sarez (top), deep in the Pamir mountains of Tajikistan, was created 90 years ago when a strong earthquake triggered a massive landslide that, in turn, became a huge dam along the Murghob River, now called the Usoi Dam. The resulting lake is perched above surrounding drainages at an elevation greater than 3000m, and is part of the watershed that drains the towering Akademi Nauk Range (see the regional image, lower). The lake is 61 km long and as deep as 500 m, and holds an estimated 17 cubic km of water. The area experiences considerable seismic activity, and scientists fear that part of the right bank may slump into the lake, creating a huge wave that will top over and possibly breach the natural dam. Such a wave would create a catastrophic flood downstream along the Bartang, Panj and Amu Darya Rivers, perhaps reaching all the way to the Aral Sea. Currently, central Asian governments, as well as the World Bank and the UN are monitoring the dam closely, and have proposed gradually lowering the lake level as a preventive measure. More information about the lake is available at the following web sites: Lake Sarez Study group, UN Report, Reliefweb Digital photograph numbers ISS002-E-7771 and ISS002-E-7479 were taken in the spring of 2001 from Space Station Alpha and are provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

High-resolution modeling of local air-sea interaction within the Marine Continent using COAMPS

NASA Astrophysics Data System (ADS)

Jensen, T. G.; Chen, S.; Flatau, M. K.; Smith, T.; Rydbeck, A.

2016-12-01

The Maritime Continent (MC) is a region of intense deep atmospheric convection that serves as an important source of forcing for the Hadley and Walker circulations. The convective activity in the MC region spans multiple scales from local mesoscales to regional scales, and impacts equatorial wave propagation, coupled air-sea interaction and intra seasonal oscillations. The complex distribution of islands, shallow seas with fairly small heat storage and deep seas with large heat capacity is challenging to model. Diurnal convection over land-sea is part of a land-sea breeze system on a small scale, and is highly influenced by large variations in orography over land and marginal seas. Daytime solar insolation, run-off from the Archipelago and nighttime rainfall tends to stabilize the water column, while mixing by tidal currents and locally forced winds promote vertical mixing. The runoff from land and rivers and high net precipitation result in fresh water lenses that enhance vertical stability in the water column and help maintain high SST. We use the fully coupled atmosphere-ocean-wave version of the Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS) developed at NRL with resolution of a few kilometers to investigate the air-sea interaction associated with the land-sea breeze system in the MC under active and inactive phases of the Madden-Julian Oscillation. The high resolution enables simulation of strong SST gradients associated with local upwelling in deeper waters and strong salinity gradients near rivers and from heavy precipitation.

Does improved access to water supply by rural households enhance the concept of safe water at the point of use? A case study from deep rural South Africa.

PubMed

Jagals, P

2006-01-01

The concept of safe water is defined by three principles: the health-related quality must be suitable, the supply/source must be accessible and the water must constantly be available in quantities sufficient for the intended use. If any one (or more) of these three elements is missing from a water services improvement programme, providing safe water is not successfully achieved. A study in a deep rural area in South Africa showed that providing small communities, using untreated river water as their only water source, with good quality water through a piped distribution system and accessible at communal taps did not fall within our parameters of safe water. The parameters for measuring the three principles were: absence of Escherichia coli in drinking water samples; accessibility by improving tap distances to within 200 m from each household; availability by assessing whether households have at least 25 L per person per day. Results show that although E. coli levels were reduced significantly, households were still consuming water with E. coli numbers at non-compliant levels. Access (distance) was improved from an average of 750 m from households to river source to an average of 120 m to new on-tap source points. This did not result in significant increases in household quantities, which on average remained around 18 L per person per day.

Geology and structure of the Pine River, Florida River, Carbon Junction, and Basin Creek gas seeps, La Plata County, Colorado

USGS Publications Warehouse

Fassett, James E.; Condon, Steven M.; Huffman, A. Curtis; Taylor, David J.

1997-01-01

Introduction: This study was commissioned by a consortium consisting of the Bureau of Land Management, Durango Office; the Colorado Oil and Gas Conservation Commission; La Plata County; and all of the major gas-producing companies operating in La Plata County, Colorado. The gas-seep study project consisted of four parts; 1) detailed surface mapping of Fruitland Formation coal outcrops in the above listed seep areas, 2) detailed measurement of joint and fracture patterns in the seep areas, 3) detailed coal-bed correlation of Fruitland coals in the subsurface adjacent to the seep areas, and 4) studies of deep-seated seismic patterns in those seep areas where seismic data was available. This report is divided into three chapters labeled 1, 2, and 3. Chapter 1 contains the results of the subsurface coal-bed correla-tion study, chapter 2 contains the results of the surface geologic mapping and joint measurement study, and chapter 3, contains the results of the deep-seismic study. A preliminary draft of this report was submitted to the La Plata County Group in September 1996. All of the members of the La Plata Group were given an opportunity to critically review the draft report and their comments were the basis for revising the first draft to create this final version of a geologic report on the major La Plata County gas seeps located north of the Southern Ute Indian Reservation.

Winter habitat use by cutthroat trout in the Snake River near Jackson, Wyoming

USGS Publications Warehouse

Harper, D.D.; Farag, A.M.

2004-01-01

Winter habitat use by Yellowstone cutthroat trout Oncorhynchus clarki bouvieri was monitored with radiotelemetry during November-March 1998-2001 in channelized and unaltered sections of the Snake River near Jackson, Wyoming. The use of run and off-channel pool habitat was significantly correlated to water temperature; run use was most frequent when mean water temperature exceeded 1.0°C, and off-channel pool use was greatest when mean water temperature was below 1.0°C. Available habitat was surveyed during winter 1999-2000 and was compared with actual habitat use. This comparison indicated that cutthroat trout avoided riffle habitat, selected deep runs, and strongly selected off-channel pool habitat. Large, deep, off-channel pools with groundwater influence were uncommon in the study area but were frequently selected as over-wintering habitat in the channelized section during all three study years. During 2000-2001, mainstem water temperatures were significantly colder than in 1998-1999 or 1999-2000, and anchor ice was observed more frequently in 2000-2001 than in 1998-1999 or 1999-2000 (on 18 d versus 5 d and 3 d, respectively). Mean water temperatures in off-channel pools were not significantly different among years. Depth and shelf ice were most frequently identified as cover elements in the channelized section. Run habitat was more common and used more frequently upstream of the channelized section. Large woody debris was more common and selected more frequently as cover in the unaltered section than in the channelized section.

Sr-Nd isotopes constrain on the deposit history of the basins in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Li, Y.; Jiang, S.

2015-12-01

The Brazos-Trinity Basin IV and Ursa Basin are situated on the northern slope of the Gulf of Mexico. The Ursa basin lies in the center of late Pleistocene Mississippi River deposition, received the sediment deposition during Marine Isotope Stage (MIS) 2- 4. The Brazos-Trinity Basin IV belongs to a part of the Brazos-Trinity fan, it recorded the turbidite deposition and hemiplegic deposition during MIS1- 5. The Sr and Nd isotopic composition of the detrital composition of the sediment in both basins indicates the change of the sediment provenance during the basin-filled process. In the Ursa basin, The difference of 87Sr/86Sr ratio and ɛNd of the detrital component between MIS1,2 (87Sr/86Sr ~ 0.7219 - 0.7321, ɛNd ~ -12 - -13.4) and MIS3,4(87Sr/86Sr ~ 0.7310 - 0.7354, ɛNd ~ -16 - -17.9) is suggested to be related with the provenance change of the detrital particles since LGM. The addition of detrital particle from Appalachians with less radiogenic 87Sr/86Sr and positive ɛNd altered the character of the sediment of the Mississippi River during the last glaciation and deglaciation. In the Brazos-Trinity Basin IV, the narrow range of 87Sr/86Sr and ɛNd indicate that the sediment source of Brazos-Trinity Basin IV had not changed obviously during MIS5e to MIS2, mostly from coastal rivers such as Brazos River, Trinity River and Sabine River. The pre-fan with 87Sr/86Sr ~0.735 and ɛNd ~ -14.5 to -16.9, which is very similar to the deep sediment in the Ursa Basin with 87Sr/86Sr ~0.733 to 0.735 and ɛNd ~ -16 to -18. It is suggested that sediments of the pre-fan of the Brazos-Trinity Basin IV were supplied from the ancestral Mississippi River Delta during the low sea level (MIS 6). During the MIS5, the discharge of Mississippi River is thought switched to its present course, ~300 km to the east.

Regional implications of heat flow of the Snake River Plain, Northwestern United States

NASA Astrophysics Data System (ADS)

Blackwell, D. D.

1989-08-01

The Snake River Plain is a major topographic feature of the Northwestern United States. It marks the track of an upper mantle and crustal melting event that propagated across the area from southwest to northeast at a velocity of about 3.5 cm/yr. The melting event has the same energetics as a large oceanic hotspot or plume and so the area is the continental analog of an oceanic hotspot track such as the Hawaiian Island-Emperor Seamount chain. Thus, the unique features of the area reflect the response of a continental lithosphere to a very energetic hotspot. The crust is extensively modified by basalt magma emplacement into the crust and by the resulting massive rhyolite volcanism from melted crustal material, presently occurring at Yellowstone National Park. The volcanism is associated with little crustal extension. Heat flow values are high along the margins of the Eastern and Western Snake River Plains and there is abundant evidence for low-grade geothermal resources associated with regional groundwater systems. The regional heat flow pattern in the Western Snake River Plains reflects the influence of crustal-scale thermal refraction associated with the large sedimentary basin that has formed there. Heat flow values in shallow holes in the Eastern Snake River Plains are low due to the Snake River Plains aquifer, an extensive basalt aquifer where water flow rates approach 1 km/yr. Below the aquifer, conductive heat flow values are about 100 mW m -2. Deep holes in the region suggest a systematic eastward increase in heat flow in the Snake River Plains from about 75-90 mW m -2 to 90-110 mW m -2. Temperatures in the upper crust do not behave similarly because the thermal conductivity of the Plio-Pleistocene sedimentary rocks in the west is lower than that in the volcanic rocks characteristic of the Eastern Snake River Plains. Extremely high heat loss values (averaging 2500 mW m -2) and upper crustal temperatures are characteristic of the Yellowstone caldera.

3D granulometry: grain-scale shape and size distribution from point cloud dataset of river environments

NASA Astrophysics Data System (ADS)

Steer, Philippe; Lague, Dimitri; Gourdon, Aurélie; Croissant, Thomas; Crave, Alain

2016-04-01

The grain-scale morphology of river sediments and their size distribution are important factors controlling the efficiency of fluvial erosion and transport. In turn, constraining the spatial evolution of these two metrics offer deep insights on the dynamics of river erosion and sediment transport from hillslopes to the sea. However, the size distribution of river sediments is generally assessed using statistically-biased field measurements and determining the grain-scale shape of river sediments remains a real challenge in geomorphology. Here we determine, with new methodological approaches based on the segmentation and geomorphological fitting of 3D point cloud dataset, the size distribution and grain-scale shape of sediments located in river environments. Point cloud segmentation is performed using either machine-learning algorithms or geometrical criterion, such as local plan fitting or curvature analysis. Once the grains are individualized into several sub-clouds, each grain-scale morphology is determined using a 3D geometrical fitting algorithm applied on the sub-cloud. If different geometrical models can be conceived and tested, only ellipsoidal models were used in this study. A phase of results checking is then performed to remove grains showing a best-fitting model with a low level of confidence. The main benefits of this automatic method are that it provides 1) an un-biased estimate of grain-size distribution on a large range of scales, from centimeter to tens of meters; 2) access to a very large number of data, only limited by the number of grains in the point-cloud dataset; 3) access to the 3D morphology of grains, in turn allowing to develop new metrics characterizing the size and shape of grains. The main limit of this method is that it is only able to detect grains with a characteristic size greater than the resolution of the point cloud. This new 3D granulometric method is then applied to river terraces both in the Poerua catchment in New-Zealand and along the Laonong river in Taiwan, which point clouds were obtained using both terrestrial lidar scanning and structure from motion photogrammetry.

Recognition of strong seasonality and climatic cyclicity in an ancient, fluvially dominated, tidally influenced point bar: Middle McMurray Formation, Lower Steepbank River, north-eastern Alberta, Canada

NASA Astrophysics Data System (ADS)

Jablonski, Bryce V. J.; Dalrymple, Robert W.

2016-04-01

Inclined heterolithic stratification in the Lower Cretaceous McMurray Formation, exposed along the Steepbank River in north-eastern Alberta, Canada, accumulated on point bars of a 30 to 40 m deep continental-scale river in the fluvial-marine transition. This inclined heterolithic stratification consists of two alternating lithologies, sand and fine-grained beds. Sand beds were deposited rapidly by unidirectional currents and contain little or no bioturbation. Fine-grained beds contain rare tidal structures, and are intensely bioturbated by low-diversity ichnofossil assemblages. The alternations between the sand and fine-grained beds are probably caused by strong variations in fluvial discharge; that are believed to be seasonal (probably annual) in duration. The sand beds accumulated during river floods, under fluvially dominated conditions when the water was fresh, whereas the fine-grained beds accumulated during the late stages of the river flood and deposition continued under tidally influenced brackish-water conditions during times of low-river flow (i.e. the interflood periods). These changes reflect the annual migration in the positions of the tidal and salinity limits within the fluvial-marine transition that result from changes in river discharge. Sand and fine-grained beds are cyclically organized in the studied outcrops forming metre-scale cycles. A single metre-scale cycle is defined by a sharp base, an upward decrease in sand-bed thickness and upward increases in the preservation of fine-grained beds and the intensity of bioturbation. Metre-scale cycles are interpreted to be the product of a longer term (decadal) cyclicity in fluvial discharge, probably caused by fluctuations in ocean or solar dynamics. The volumetric dominance of river-flood deposits within the succession suggests that accumulation occurred in a relatively landward position within the fluvial-marine transition. This study shows that careful observation can reveal much about the interplay of processes within the fluvial-marine transition, which in turn provides a powerful tool for determining the palaeo-environmental location of a deposit within the fluvial-marine transition.

Understanding the Complexities of Communicating Management Decisions on the Subsistence Use of Yukon River Salmon

NASA Astrophysics Data System (ADS)

Brooks, J. F.; Trainor, S.

2017-12-01

Over 20,000 residents in Alaska and Yukon Territory rely upon the Yukon River to provide them harvests of Pacific salmon each year. Salmon are a highly valued food resource and the practice of salmon fishing along the Yukon is deep rooted in local cultures and traditions. Potential future impacts of climate change on the health of Yukon River salmon stocks could be significant. Collaborative managerial processes which incorporate the viewpoints of subsistence stakeholders will be crucial in enabling communities and managerial institutions to adapt and manage these impacts. However, the massive extent of the Yukon River makes it difficult for communities rich with highly localized knowledge to situate themselves within a drainage-wide context of resource availability, and to fully understand the implications that management decisions may have for their harvest. Differences in salmon availability and abundance between the upper and lower Yukon, commercial vs. subsistence fishery interests, and enforcement of the international Pacific Salmon Treaty further complicate understanding and makes the topic of salmon as a subsistence resource a highly contentious issue. A map which synthesizes the presence and absence of Pacific salmon throughout the entire Yukon River drainage was requested by both subsistence fishers and natural resource managers in Alaska in order to help facilitate productive conversations about salmon management decisions. Interviews with Alaskan stakeholders with managerial, biological, and subsistence harvest backgrounds were carried out and a literature review was conducted in order to understand what such a map should and could accomplish. During the research process, numerous data gaps concerning the distribution of salmon along the Yukon River were discovered, and insights about the complexities involved in translating science when it is situated within a charged political, economic, and cultural context were revealed. Preliminary maps depicting the timing of salmon pulses, the data gaps present, and the political landscape of the Yukon River were created. A future step of developing an interactive online mapping tool has been identified as a way to most clearly communicate the complexity of the interwoven systems involved in the status of Yukon River salmon and their management.

Deep soil dynamics of floodplain carbon in the Central Valley of California

NASA Astrophysics Data System (ADS)

Steger, Kristin; Kim, Amy T.; Viers, Joshua H.; Fiener, Peter; Smart, David R.

2017-04-01

Active floodplains can putatively store large amounts of organic carbon (SOC) in subsoils originating from catchment erosion processes with subsequent floodplain deposition. Changes in catchment land use patterns and river management to optimize agricultural use of the floodplain or to restore the floodplain back to natural systems may alter SOC stocks in these soils. Our study focussed on the assessment of SOC pools associated with alluvial floodplain soils converting from conventional arable use to restored flooding and floodplain vegetation. We evaluated depth-dependent SOC contents using 21 drillings down to 3m and 10 drillings down to 7m along a transect through a floodplain area of the lower Cosumnes River, a non-constrained tributary to the Sacramento - San Joaquin Delta in California. In general, our data underline the importance of carbon stocks in subsoils >1m, which represent up to 19 and 6% of SOC stocks at the different sampling locations accounting for drillings down to 3 and 7m, respectively. All of our sampling sites revealed a SOC-rich buried A horizon between 70 and 130cm with SOC concentrations between 11 and 17g/kg, representative of the functioning floodplain system pre-disturbance. Radiocarbon dating showed that the 14C age in the buried horizon was younger than in the overlaying soils, indicating a substantial sedimentation phase with sediments of low SOC concentrations and higher carbon age. This sedimentation phase was probably associated with the huge upstream sediment production resulting from the hydraulic gold mining at the Cosumnes River starting around 1860. Apart from larger SOC contents in the buried horizon compared to the recent topsoil, its 13C and 15N isotopic signature also differed suggesting a change in long-term input of plant organic matter as well as different fertilization regimes during the agricultural use of the area from approx. 1890 onwards. In summary, deep alluvial soils in floodplains store large amounts of SOC not yet accounted for in global models. Intensive agricultural use of these floodplains often combined with river regulation and embanking of floodplain areas may lead to a slow but continuous release of the buried SOC to the atmosphere. However, restoration of floodplains may promote the stabilization of alluvial SOC in floodplains and hence contribute to more sustainable soils.

Biogeochemical characteristics of suspended particulate matter in deep chlorophyll maximum layers in the southern East China Sea

NASA Astrophysics Data System (ADS)

Liu, Qianqian; Kandasamy, Selvaraj; Lin, Baozhi; Wang, Huawei; Chen, Chen-Tung Arthur

2018-04-01

Continental shelves and marginal seas are key sites of particulate organic matter (POM) production, remineralization and sequestration, playing an important role in the global carbon cycle. Elemental and stable isotopic compositions of organic carbon and nitrogen are thus frequently used to characterize and distinguish POM and its sources in suspended particles and surface sediments in the marginal seas. Here we investigated suspended particulate matter (SPM) collected around deep chlorophyll maximum (DCM) layers in the southern East China Sea for particulate organic carbon and nitrogen (POC and PN) contents and their isotopic compositions (δ13CPOC and δ15NPN) to understand provenance and dynamics of POM. Hydrographic parameters (temperature, salinity and turbidity) indicated that the study area was weakly influenced by freshwater derived from the Yangtze River during summer 2013. Elemental and isotopic results showed a large variation in δ13CPOC (-25.8 to -18.2 ‰) and δ15NPN (3.8 to 8.0 ‰), but a narrow molar C / N ratio (4.1-6.3) and low POC / Chl a ratio ( < 200 g g-1) in POM, and indicated that the POM in DCM layers was newly produced by phytoplankton. In addition to temperature effects, the range and distribution of δ13CPOC were controlled by variations in primary productivity and phytoplankton species composition; the former explained ˜ 70 % of the variability in δ13CPOC. However, the variation in δ15NPN was controlled by the nutrient status and δ15NNO3- in seawater, as indicated by similar spatial distribution between δ15NPN and the current pattern and water masses in the East China Sea; although interpretations of δ15NPN data should be verified with the nutrient data in future studies. Furthermore, the POM investigated was weakly influenced by the terrestrial OM supplied by the Yangtze River during summer 2013 due to the reduced sediment supply by the Yangtze River and north-eastward transport of riverine particles to the northern East China Sea. We demonstrated that the composition of POM around DCM layers in the southern East China Sea is highly dynamic and largely driven by phytoplankton abundance. Nonetheless, additional radiocarbon and biomarker data are needed to re-evaluate whether or not the POM around the DCM water depths is influenced by terrestrial OM in the river-dominated East China Sea.

Deepwater Spawning of Fall Chinook Salmon (Oncorhynchus tshawtscha) Near Ives and Pierce Island of the Columbia River, 2003-2004 Annual Report.

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

Mueller, Robert

2004-10-01

Pacific Northwest National Laboratory conducted video-based boat surveys in fall 2003 to identify spawning areas for fall Chinook salmon (Oncorhynchus tshawytscha) in deep water (>1 m) downstream of Bonneville Dam. This report documents the number and extent of Chinook salmon spawning near Ives and Pierce islands of the Columbia River, and is the fifth in a series of reports prepared since 1999. The primary objective of this study was to find deepwater spawning locations of fall Chinook salmon in the main Columbia River channel, collect additional data on physical habitat parameters at spawning sites, and provide estimates of adult spawnersmore » in the surveyed area. The secondary objective was to document the occurrence of any chum salmon (O. keta) redds in the deeper sections near below Hamilton Creek. Results from the 2003 study show a continuing trend upward in the number of fall Chinook salmon redds found within the survey zones. The number of fall Chinook redds found in the Ives Pierce Island complex (river km 228.5) has increased by a factor of five since the surveys began in 1999. The total number of redds found during 2003 was 336, which compares to 192 in 2002, 43 in 2001, 76 in 2000, and 64 in 1999. The redds encompassed an area of 13.7 ha occurring adjacent to the lower part of Ives Island and Pierce Island. Peak spawning activity, based on redd counts and live fish seen near redds, was on or near November 24, 2003. An expanded redd count based on percentage of video coverage in the primary and secondary search zones was 3,218 fall Chinook salmon redds in water exceeding 1 m deep and flowing at about 125 kcfs. Fall Chinook salmon redds were found at water depths from 1.07 to 7.6 m and were constructed predominantly of medium cobbles ranging from 7.6 to 15.2 cm in diameter. Two chum salmon redds were found in a small location downstream from Hamilton Creek in water depths of approximately 1 m. No salmon redds were found in other areas searched, including near Woodward, Tanner, and McCord creeks.« less

Global dust sources detection using MODIS Deep Blue Collection 6 aerosol products

NASA Astrophysics Data System (ADS)

Pérez García-Pando, C.; Ginoux, P. A.

2015-12-01

Our understanding of the global dust cycle is limited by a dearth of information about dust sources, especially small-scale features which could account for a large fraction of global emissions. Remote sensing sensors are the most useful tool to locate dust sources. These sensors include microwaves, visible channels, and lidar. On the global scale, major dust source regions have been identified using polar orbiting satellite instruments. The MODIS Deep Blue algorithm has been particularly useful to detect small-scale sources such as floodplains, alluvial fans, rivers, and wadis , as well as to identify anthropogenic sources from agriculture. The recent release of Collection 6 MODIS aerosol products allows to extend dust source detection to the entire land surfaces, which is quite useful to identify mid to high latitude dust sources and detect not only dust from agriculture but fugitive dust from transport and industrial activities. This presentation will overview the advantages and drawbacks of using MODIS Deep Blue for dust detection, compare to other instruments (polar orbiting and geostationary). The results of Collection 6 with a new dust screening will be compared against AERONET. Applications to long range transport of anthropogenic dust will be presented.

3D numerical simulation of flow field with incompletely flaring gate pier in large unit discharge and deep tail water project

NASA Astrophysics Data System (ADS)

Zhao, Zhou; Junxing, Wang

2018-06-01

Limited by large unit discharge above the overflow weir and deep tail water inside the stilling basin, the incoming flow inside stilling basin is seriously short of enough energy dissipation and outgoing flow still carries much energy with large velocity, bound to result in secondary hydraulic jump outside stilling basin and scour downstream river bed. Based on the RNG k-ɛ turbulence model and the VOF method, this paper comparatively studies flow field between the conventional flat gate pier program and the incompletely flaring gate pier program to reveal energy dissipation mechanism of incomplete flaring gate pier. Results show that incompletely flaring gate pier can greatly promote the longitudinally stretched water jet to laterally diffuse and collide in the upstream region of stilling basin due to velocity gradients between adjacent inflow from each chamber through shrinking partial overflow flow chamber weir chamber, which would lead to large scale vertical axis vortex from the bottom to the surface and enhance mutual shear turbulence dissipation. This would significantly increase energy dissipation inside stilling basin to reduce outgoing velocity and totally solve the common hydraulic problems in large unit discharge and deep tail water projects.

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

Wellman, Dawn M.; Triplett, Mark B.; Freshley, Mark D.

DOE-EM, Office of Groundwater and Soil Remediation and DOE Richland, in collaboration with the Hanford site and Pacific Northwest National Laboratory, have established the Deep Vadose Zone Applied Field Research Center (DVZ-AFRC). The DVZ-AFRC leverages DOE investments in basic science from the Office of Science, applied research from DOE EM Office of Technology Innovation and Development, and site operation (e.g., site contractors [CH2M HILL Plateau Remediation Contractor and Washington River Protection Solutions], DOE-EM RL and ORP) in a collaborative effort to address the complex region of the deep vadose zone. Although the aim, goal, motivation, and contractual obligation of eachmore » organization is different, the integration of these activities into the framework of the DVZ-AFRC brings the resources and creativity of many to provide sites with viable alternative remedial strategies to current baseline approaches for persistent contaminants and deep vadose zone contamination. This cooperative strategy removes stove pipes, prevents duplication of efforts, maximizes resources, and facilitates development of the scientific foundation needed to make sound and defensible remedial decisions that will successfully meet the target cleanup goals for one of DOE EM's most intractable problems, in a manner that is acceptable by regulators.« less

Ground-water resources of Riverton irrigation project area, Wyoming

USGS Publications Warehouse

Morris, Donald Arthur; Hackett, O.M.; Vanlier, K.E.; Moulder, E.A.; Durum, W.H.

1959-01-01

The Riverton irrigation project area is in the northwestern part of the Wind River basin in west-central Wyoming. Because the annual precipitation is only about 9 inches, agriculture, which is the principal occupation in the area, is dependent upon irrigation. Irrigation by surface-water diversion was begum is 1906; water is now supplied to 77,716 acres and irrigation has been proposed for an additional 31,344 acres. This study of the geology and ground-water resources of the Riverton irrigation project, of adjacent irrigated land, and of nearby land proposed for irrigation was begun during the summer of 1948 and was completed in 1951. The purpose of the investigation was to evaluate the ground-water resources of the area and to study the factors that should be considered in the solution of drainage and erosional problems within the area. The Riverton irrigation project area is characterized by flat to gently sloping stream terraces, which are flanked by a combination of badlands, pediment slopes, and broad valleys. These features were formed by long-continued erosion in an arid climate of the essentially horizontal, poorly consolidated beds of the Wind River formation. The principal streams of the area flow south-eastward. Wind River and Fivemile Creek are perennial streams and the others are intermittent. Ground-water discharge and irrigation return flow have created a major problem in erosion control along Fivemile Creek. Similar conditions might develop along Muddy and lower Cottonwood Creeks when land in their drainage basins is irrigated. The bedrock exposed in the area ranges in age from Late Cretaceous to early Tertiary (middle Eocene). The Wind River formation of early and middle Eocene age forms the uppermost bedrock formation in the greater part of the area. Unconsolidated deposits of Quaternary age, which consist of terrace gravel, colluvium, eolian sand and silt. and alluvium, mantle the Wind River formation in much of the area. In the irrigated parts of the project, water from domestic use is obtained chiefly from the sandstone beds of the Wind River formation although some is obtained from the alluvium underlying the bottom land and from the unconsolidated deposits underlying the lower terraces along the Wind River. Although adequate quantities if water for domestic use are available from the Wind River formation, there quantities are not considered to be large enough to warrant pumping of ground water for irrigation. Only a few wells are in the nonirrigated part of the area. When this new land is irrigated, a body of ground water will gradually form in the terrace deposits and the alluvial and colluvial-alluvial deposits. Eventually, the terrace deposits may yield adequate quantities of water for domestic and stock use, but only locally are the alluvial and colluvial-alluvial deposits likely to become suitable aquifers. In the Riverton irrigation project area, ground water occurs under water-table conditions near the surface and under artesian conditions in certain strata at both shallow and greater depths. Irrigation is the principal source of recharge to the shallow aquifers; the water level in wells that tap these aquifers fluctuates with irrigation. The depth to water in the shallow wells ranges from less than 1 foot to about 30 feet below the land surface, depending on the season of the year and on the length of time the land has been irrigated. The water level in the wells that tap the deep confined aquifers , which receive recharge indirectly from surface sources, fluctuates only slightly because the recharge and discharge are more constant. In most places the depth to water in wells penetrating the deep confined aquifers is mush greater than that in shallow wells. but in certain low areas water from the deep aquifers flows at the surface from wells. Ground water moves from the area of recharge in the direction of the hydraulic gradient and is discharges either by evapotranspiration; by inflow into streams, drains, or lakes; by pumping or flow of wells; or by flow of springs. Waterlogging and the associated development of saline soils are common in parts of the Riverton irrigation project and adjacent irrigated land. The waterlogging is in part the result of the infiltration of irrigation water in excess of the capacity of the aquifers to store and transmit this added recharge. The solution of the drainage problems involves the consideration of a number of factors, some of which are inadequately known in some parts of the area and require further investigation before fully effective drainage measures can be designed. The results of an aquifer test to determine the hydrologic characteristics of the Wind River formation at Riverton indicate a transmissibility of 10,000 gallons per day per foot (10,000 gpd per ft) and a storage coefficient of 2 x 10-4. The results of the test provide a part of the necessary foundation for the solution of present and future water-supply problems at Riverton and throughout the project area. Water from shallow aquifers in irrigated tracts in the Riverton irrigation project area generally contains large amounts of dissolved solids that were leached from the soil and rocks by infiltrating irrigation water. However, wells tapping beds that receive considerable recharge from influent canal and drain seepage yield water of relatively low mineralizatoin. Dilute water is obtained also from some shallow wells in the alluvial bottom lands and on low stream terraces that border the Wind Rover. Water from deep aquifers generally is more dilute than that from shallow aquifers. However, ground water from the deep aquifers, unmixed with irrigation water, generally has a percent sodium greater than 80. Analyses of salt crusts on the ground surface in low areas that are affected by effluent seepage and a high water table show predominance of sodium sulfate salinity, and from determinations of the water-soluble and acid-soluble substances in several samples of soil and shale it is apparent that harmful concentrations of salts are being deposited in poorly drained area. Although most of the soul in the Midvale irrigation district is of the normal arid type, analyses of soil samples show that saline, nonsaline alkaline, and saline alkaline types also are present.

Recent trends and variations in Baltic Sea temperature, salinity, stratification and circulation

NASA Astrophysics Data System (ADS)

Elken, Jüri; Lehmann, Andreas; Myrberg, Kai

2015-04-01

The presentation highlights the results of physical oceanography from BACC II (Second BALTEX Assessment of Climate Change for the Baltic Sea basin) book based on the review of recent literature published until 2013. We include also information from some more recent publications. A recent warming trend in sea surface waters has been clearly demonstrated by all available methods: in-situ measurements, remote sensing data and modelling tools. In particular, remote sensing data for the period 1990-2008 indicate that the annual mean SST has increased even by 1°C per decade, with the greatest increase in the northern Bothnian Bay and also with large increases in the Gulf of Finland, the Gulf of Riga, and the northern Baltic Proper. Although the increase in the northern areas is affected by the recent decline in the extent and duration of sea ice, and corresponding changes in surface albedo, warming is still evident during all seasons and with the greatest increase occurring in summer. The least warming of surface waters (0.3-0.5°C per decade) occurred northeast of Bornholm Island up to and along the Swedish coast, probably owing to an increase in the frequency of coastal upwelling forced by the westerly wind events. Comparing observations with the results of centennial-scale modelling, recent changes in sea water temperature appear to be within the range of the variability observed during the past 500 years. Overall salinity pattern and stratification conditions are controlled by river runoff, wind conditions, and salt water inflows through the Danish straits. The mean top-layer salinity is mainly influenced by the accumulated river runoff, with higher salinity during dry periods and lower salinity during wet periods. Observations reveal a low-salinity period above the halocline starting in the 1980s. The strength of stratification and deep salinity are reduced when the mean zonal wind stress increases, as it occurred since 1987. Major Baltic Inflows of highly saline water of North Sea origin occur sporadically and transport high-saline water into the deep layers of the Baltic Sea. These inflow events occur when high pressure over the Baltic region with easterly winds is followed by several weeks of strong westerly winds; changes in the inflow activity are related to the frequency of deep cyclones and their pathways over the Baltic area. Major inflows are often followed by a period of stagnation during which saline stratification decreases and oxygen deficiency develops in the deep basins of the central Baltic. Major inflows are usually of barotropic character. They normally occur during winter and spring and transport relatively cold, salty and oxygen-rich waters to the deep basins. Since 1996, another type of inflows have been observed during summer or early autumn. These inflows are of baroclinic character and transport high-saline, but warm and low-oxygen water into the deep layers of the Baltic Sea. Event-like water exchange and mixing anomalies, driven by specific atmospheric forcing patterns like sequences of deep cyclones, occur also in other parts of the Baltic Sea.

Miocene oceanographic changes of the western equatorial Atlantic (Ceara Rise) based on calcareous dinoflagellate cysts

NASA Astrophysics Data System (ADS)

Heinrich, S.; Zonneveld, K. A. F.; Willems, H.

2010-09-01

The middle- and upper Miocene represent a time-interval of major changes in palaeoceanography that favoured the cooling of the climate and culminated in the Northern Hemisphere Glaciation (NHG). The basis for the development of the modern deepwater circulation pattern, e.g. thermohaline circulation, was hereby established. Tectonic events played a key role in the progressing Miocene oceanography, such as the narrowing of the Panama gateway (e.g. Duque-Caro 1990) and the possible linked changes in North Atlantic Deep Water formation (Lear et al. 2003). However, the complex interaction between the closing of the Panama Gateway, the development of NADW, and thus the oceanographic progression towards our present day circulation is far from being fully understood. We want to improve the understanding of these processes by establishing a detailed palaeoceanographic reconstruction of the western equatorial Atlantic Ocean on the basis of calcareous dinoflagellate cyst (dinocyst) associations. Within this study, we investigated sediment samples from ODP Site 926A by defining the calcareous dinocyst assemblage. Site 926A is located at the southwestern flank of the Ceara Rise, an area of highest sensitivity to global deep water circulation changes. At about 12 Ma, when NADW production increased (e.g. Wright et al. 1992), we see a distinct increase in the absolute abundances of the calcareous dinocysts. This might be related to enhanced productivity or to better carbonate preservation. At 11.3 Ma, Leonella granifera, a species known to be strongly related to terrestrial input occurs. This could be a signal for the initiation of the Amazon River as a transcontinental river with the development of the Amazon fan (11.8 - 11.3 Ma; Figueiredo et al. 2009) in relation to Andean tectonism. References: Duque-Caro, H. (1990): Neogene stratigraphy, paleoceanography and palebiology in Northwest South America and the evolution of the Panama Seaway. Palaeogeography, Palaeoclimatology, Palaeoecology 77, 203-234. Figueiredo, J., Hoorn, C., van der Veen, P., Soares, E. (2009): Late Miocene onset of the Amazon River and the Amazon deep-sea fan: Evidence from the Foz do Amazonas Basin. Geology; v. 37, no. 7; p. 619-622. Lear, C.H., Rosenthal, Y., Wright, J.D. (2003): The closing of a seaway: ocean water masses and global climate change. Earth and Planetary Science Letters 210, 425-436. Wright, J.D., Miller, K.G., Fairbanks, R.G. (1992): Early and middle Miocene stable isotopes: implications for deepwater circulation and climate. Paloceanography 7(3): 357-398.

Spatial variations in fluvial incision across the eastern margin of Tibet reveal locus of deformation in the deep crust

NASA Astrophysics Data System (ADS)

Kirby, Eric

2017-04-01

The manifestation of coupling among climate, erosion and tectonics along steep topographic margins of orogenic plateaus is strongly dependent on the processes driving crustal thickening. Along the eastern margin of the Tibetan Plateau, a long-standing and vigorous debate persists over whether mountain building occurred largely along upper-crustal faults or was the consequence of distributed thickening in the lower crust. Here I revisit this debate and show how surface deformation recorded by geomorphology over millennial timescales (10^4-105 yr) can yield insight into the role the deep crust along plateau margins. In contrast to the intensively studied Longmen Shan, the topographic margin of the Tibetan Plateau north of the Sichuan Basin follows the north-south Min Shan and cuts orthogonally across the structural grain of the Mesozoic West Qinling orogen. The lack of a direct association of topography with upper crustal faults affords an opportunity to evaluate the patterns of differential rock uplift from geomorphology. First, I employ an empirical calibration of river profile steepness (channel gradient normalized for drainage basin area) and erosion rate from cosmogenic 10Be concentrations in modern sediment. Application to the channels draining the plateau margin reveals a locus of high (300-500 m/Myr) erosion rate coincident with the Min Shan. Second, I present new results of surveying and dating of fluvial terraces developed along the Bailong Jiang, one of the major rivers draining across the plateau margin. A preliminary chronology of terrace formation and abandonment based on radiocarbon and OSL dating of fluvial deposits reveals systematic spatial gradients in fluvial incision, with highest incision rates (1000-2000 m/Myr) localized along the axis of the Min Shan and decreasing toward both the foreland and the plateau. This locus of incision has apparently been sustained through multiple generations of terrace formation and abandonment since at least 80 ka and thus is interpreted to reflect sustained differential rock uplift along this axis. The wavelength of the region of highest incision rates is 80 km and requires either 1) a deeply buried tip of a blind fault, or 2) thickening in the deep crust. We argue that terrace deformation and associated rock uplift likely reflects flow and thickening of deep Tibetan crust against the foreland of the West Qinling.

Spatial variations in fluvial incision across the eastern margin of Tibet reveal locus of thickening in the deep crust

NASA Astrophysics Data System (ADS)

Kirby, Eric; Zhang, Huiping; Chen, Jie

2016-04-01

The manifestation of coupling among climate, erosion and tectonics along steep topographic margins of orogenic plateaus is strongly dependent on the processes driving crustal thickening. Along the eastern margin of the Tibetan Plateau, a long-standing an vigorous debate persists over whether mountain building occurred largely along upper-crustal faults or was the consequence of distributed thickening in the lower crust. Here we revisit this debate and show how surface deformation recorded by geomorphology over millennial timescales (104-105 yr) can yield insight into the role the deep crust along plateau margins. In contrast to the intensively studied Longmen Shan, the topographic margin of the Tibetan Plateau north of the Sichuan Basin follows the north-south Min Shan and cuts orthogonally across the structural grain of the Mesozoic West Qinling orogen. The lack of a direct association of topography with upper crustal faults affords an opportunity to evaluate the patterns of differential rock uplift from geomorphology. First, we employ an empirical calibration of river profile steepness (channel gradient normalized for drainage basin area) and erosion rate from cosmogenic 10Be concentrations in modern sediment. Application to the channels draining the plateau margin reveals a locus of high (300-500 m/Myr) erosion rate coincident with the Min Shan. Second, we present new results of surveying and dating of fluvial terraces developed along the Bailong Jiang, one of the major rivers draining across the plateau margin. A preliminary chronology of terrace tread deposits based on radiocarbon and OSL samples reveals systematic spatial gradients in fluvial incision, with highest incision rates (1000-2000 m/Myr) localized along the axis of the Min Shan and decreasing toward both the foreland and the plateau. This locus of incision has apparently been sustained through multiple generations of terrace formation and abandonment since ca. 80ka and thus is interpreted to reflect sustained differential rock uplift along this axis. The wavelength of the region of highest incision rates is ˜80 km and requires either 1) a deeply buried tip of a blind fault, or 2) thickening in the deep crust. We argue that terrace deformation and associated rock uplift likely reflects flow and thickening of deep Tibetan crust against the foreland of the West Qinling.

Using Heat as a Tracer to Estimate Saline Groundwater Fluxes from the Deep Aquifer System to the Shallow Aquifers and the Rio Grande in the Mesilla Basin, New Mexico, USA

NASA Astrophysics Data System (ADS)

Pepin, J. D.; Robertson, A.; Ferguson, C.; Burns, E. R.

2017-12-01

Heat is used as a tracer to estimate vertical groundwater flow and associated saline fluxes from deep (greater than 1 km) parts of the Mesilla Basin regional aquifer to the Rio Grande. Profiles of temperature with depth below ground surface are used to locate groundwater upflow zones and to estimate associated salinity fluxes. The results of this study will inform understanding of the impact of deep saline groundwater on regional water supplies. The Mesilla Basin in southern New Mexico, Texas, and Chihuahua, Mexico was designated by the U.S. as a priority transboundary aquifer in part because of the presence of the Rio Grande within the basin. Declining water levels, deteriorating water quality in both the aquifer and the river, and increasing use of water resources on both sides of the international border raise concerns about the sustainability of regional water supplies. The Rio Grande chloride concentration increases by about 130% (120 ppm to 280 ppm) as the river traverses the Mesilla Basin. Previous research attributed this reduction in water quality to the upwelling of deep sedimentary brines and geothermal waters within the basin. However, the spatial distribution of these upflow zones and their groundwater flow rates are poorly understood. Temperature profiles from 374 existing boreholes within the Mesilla Basin indicate that temperature-profile shape is affected by heat advection in the basin. Three distinct geothermal upflow zones were identified along regional fault zones in the study area based on the temperature profiles. Groundwater in these zones is considered thermal, having temperatures greater than 50°C at depths of less than 200 m. Identification of upflow-zone profiles combines analysis of temperature profiles, lithologic records, well-completion data, and profile derivatives. The Bredehoeft and Papadopulos (1965) one-dimensional heat-transport analytical solution will be applied to upflow-zone profiles to estimate the corresponding vertical groundwater flow rates. Temperature, heat flow, and salinity maps will be constructed to approximate the areal extents of identified upflow zones. These areal estimates will then be combined with the 1D vertical groundwater flow calculations and salinity data to quantify volumetric salinity fluxes to the shallow aquifer system and Rio Grande.

Numerically Simulating Carbonate Mineralization of Basalt with Injection of Carbon Dioxide into Deep Saline Formations

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

White, Mark D.; McGrail, B. Peter; Schaef, Herbert T.

2006-07-08

The principal mechanisms for the geologic sequestration of carbon dioxide in deep saline formations include geological structural trapping, hydrological entrapment of nonwetting fluids, aqueous phase dissolution and ionization, and geochemical sorption and mineralization. In sedimentary saline formations the dominant mechanisms are structural and dissolution trapping, with moderate to weak contributions from hydrological and geochemical trapping; where, hydrological trapping occurs during the imbibition of aqueous solution into pore spaces occupied by gaseous carbon dioxide, and geochemical trapping is controlled by generally slow reaction kinetics. In addition to being globally abundant and vast, deep basaltic lava formations offer mineralization kinetics that makemore » geochemical trapping a dominate mechanism for trapping carbon dioxide in these formations. For several decades the United States Department of Energy has been investigating Columbia River basalt in the Pacific Northwest as part of its environmental programs and options for natural gas storage. Recently this nonpotable and extensively characterized basalt formation is being reconsidered as a potential reservoir for geologic sequestration of carbon dioxide. The reservoir has an estimated storage capacity of 100 giga tonnes of carbon dioxide and comprises layered basalt flows with sublayering that generally alternates between low permeability massive and high permeability breccia. Chemical analysis of the formation shows 10 wt% Fe, primarily in the +2 valence. The mineralization reaction that makes basalt formations attractive for carbon dioxide sequestration is that of calcium, magnesium, and iron silicates reacting with dissolved carbon dioxide, producing carbonate minerals and amorphous quartz. Preliminary estimates of the kinetics of the silicate-to-carbonate reactions have been determined experimentally and this research is continuing to determine effects of temperature, pressure, rock composition and mineral assemblages on the reaction rates. This study numerically investigates the injection, migration and sequestration of supercritical carbon dioxide in deep Columbia River basalt formations using the multifluid subsurface flow and reactive transport simulator STOMP-CO2 with its ECKEChem module. Simulations are executed on high resolution multiple stochastic realizations of the layered basalt systems and demonstrate the migration behavior through layered basalt formations and the mineralization of dissolved carbon dioxide. Reported results include images of the migration behavior, distribution of carbonate formation, quantities of injected and sequestered carbon dioxide, and percentages of the carbon dioxide sequestered by different mechanisms over time.« less

An update of hydrologic conditions and distribution of selected constituents in water, Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2006-08

USGS Publications Warehouse

Davis, Linda C.

2010-01-01

Since 1952, radiochemical and chemical wastewater discharged to infiltration ponds (also called percolation ponds), evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched groundwater wells in the USGS groundwater monitoring networks during 2006-08. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2005 to March-May 2008, water levels in wells generally remained constant or rose slightly in the southwestern corner of the INL. Water levels declined in the central and northern parts of the INL. The declines ranged from about 1 to 3 feet in the central part of the INL, to as much as 9 feet in the northern part of the INL. Water levels in perched groundwater wells around the Advanced Test Reactor Complex (ATRC) also declined. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2006-08. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In April or October 2008, reportable concentrations of tritium in groundwater ranged from 810 ? 70 to 8,570 ? 190 picocuries per liter (pCi/L), and the tritium plume extended south-southwestward in the general direction of groundwater flow. Tritium concentrations in water from wells completed in shallow perched groundwater at the ATRC were less than the reporting levels. Tritium concentrations in deep perched groundwater exceeded the reporting level in 11 wells during at least one sampling event during 2006-08 at the ATRC. Tritium concentrations from one or more zones in each well were reportable in water samples collected at various depths in six wells equipped with multi-level WestbayTM packer sampling systems. Concentrations of strontium-90 in water from 24 of 52 aquifer wells sampled during April or October 2008 exceeded the reporting level. Concentrations ranged from 2.2 ? 0.7 to 32.7 ? 1.2 pCi/L. Strontium-90 has not been detected within the eastern Snake River Plain aquifer beneath the ATRC partly because of the exclusive use of waste-disposal ponds and lined evaporation ponds rather than using the disposal well for radioactive-wastewater disposal at ATRC. At the ATRC, the strontium-90 concentration in water from one well completed in shallow perched groundwater was less than the reporting level. During at least one sampling event during 2006-08, concentrations of strontium-90 in water from nine wells completed in deep perched groundwater at the ATRC were greater than reporting levels. Concentrations ranged from 2.1?0.7 to 70.5?1.8 pCi/L. At the Idaho Nuclear Technology and Engineering Center (INTEC), the reporting level was exceeded in water from two wells completed in deep perched groundwater. During 2006-08, concentrations of cesium-137, plutonium-238, and plutonium-239, -240 (undivided), and americium-241 were less than the reporting level in water samples from all wells and all zones in wells equipped with multi-level WestbayTM packer sampling systems

Dynamics of the transfer of terrestrial organic matter in the late Quaternary turbiditic system of the Ogooué River (Gabon)

NASA Astrophysics Data System (ADS)

Mignard, Salomé; Mulder, Thierry; Martinez, Philippe; Garlan, Thierry

2016-04-01

In many cases (Hedges et al., 1995, Xing et al., 2011) the supply of terrestrial organic matter (OM) in the oceanic environment is confined to the continental and upper slope of continental margins. However, some recent studies (Huc et al., 2001, Baudin et al., 2010, Biscara et al., 2011, Stetten et al., 2015) demonstrated that significant amounts of continental OM can be transported and deposited in deep sea sediments. This transfer is more efficient in turbiditic systems which are linked to important river deltas. In such systems, the terrigenous influx are important and the downslope sediment-laden currents can indeed transport and rapidly bury important quantities of TOM transferred from the river mouth and the shelf to the abyssal plain. The turbiditic system associated with the Ogooué River offshore Gabon has been selected to study more precisely the modalities of transfer of continental OM from the shelf to the deep offshore. The works focuses on the concentration of OM in both hemipelagites and turbidites as well as the different parameters influencing the spatial distribution and concentration. For this study 10 cores located along the system from the continental shelf to the distal lobes have been selected. The quantity of OM in the sediments as well as its origin (continental vs marine) have been measured using bulk geochemical analyses (% OC, δ13Corg). The stratigraphy of the cores was determined using a combination of planktonic foraminiferal assemblages, δ18O on benthic foraminifers and 14C dates on planktonic foraminifers, and calcium carbonate content calibrated with XRF measurements. The studied cores contain various amounts of organic carbon ranging from 0.7wt% to more than 9wt%. The highest contents are found in turbidite beds where woody detritus and well preserved fragmentary leaf debris are concentrated. In the hemipelagic facies, organic matter is composed of a mixture of marine and land derived organic matter associated with clay-size sediments. This organic sedimentation is highly sensitive to the variations of the sea level due to the alternation between glacial and interglacial times. Glacial periods are characterized by higher amounts of organic matter in hemipelagic deposits, with a higher contribution of continental material, and by the presence of frequent organic rich turbiditic beds. On the contrary, during interglacial periods very few turbiditic events are recorded and the OM in hemipelagic sediments is mainly of marine origin and in lesser quantity. When the sea-level is high, the Ogooué delta is disconnected from the canyon heads and the sediments delivered by the river are deposited on the shelf and mobilized by the strong South-North coastal drift currents. During low sea-level periods, the river discharges its sediments rich in terrestrial OM directly in the canyons heads bypassing the shelf. The low sea level also generates increased erosion of the shelf sediments containing globally high rate of reworked continental OM.

Isotopic Evidence of Nitrate Sources and its Relationship to Algae in the San Joaquin River, California

NASA Astrophysics Data System (ADS)

Silva, S. R.; Kendall, C.; Young, M. B.; Stringfellow, W. T.; Borglin, S. E.; Kratzer, C. R.; Dahlgren, R. A.; Schmidt, C.; Rollog, M. E.

2007-12-01

Many competing demands have been placed on the San Joaquin River including deep water shipping, use as agricultural and drinking water, transport of agricultural and urban runoff, and recreation. These long-established demands limit the management options and increase the importance of understanding the river dynamics. The relationships among sources of water, nitrate, and algae in the San Joaquin River must be understood before management decisions can be made to optimize aquatic health. Isotopic analyses of water samples collected along the San Joaquin River in 2005-2007 have proven useful in assessing these relationships: sources of nitrate, the productivity of the San Joaquin River, and the relationship between nitrate and algae in the river. The San Joaquin River receives water locally from wetlands and agricultural return flow, and from three relatively large tributaries whose headwaters are in the Sierra Nevada. The lowest nitrate concentrations occur during periods of high flow when the proportion of water from the Sierra Nevada is relatively large, reflecting the effect of dilution from the big tributaries and indicating that a large fraction of the nitrate is of local origin. Nitrogen isotopes of nitrate in the San Joaquin River are relatively high (averaging about 12 per mil), suggesting a significant source from animal waste or sewage and/or the effects of denitrification. The d15N of nitrate varies inversely with concentration, indicating that these high isotopic values are also a local product. The d15N values of nitrate from most of the local tributaries is lower than that in the San Joaquin suggesting that nitrate from these tributaries does not account for a significant fraction of nitrate in the river. The source of the non-tributary nitrate must be either small unmeasured surface inputs or groundwater. To investigate whether groundwater might be a significant source of nitrate to the San Joaquin River, groundwater samples are being collected monthly from over 20 bank and in-stream wells. Preliminary data suggest that much of the groundwater nitrate has been variably denitrified thereby increasing its d15N values, but not by enough to account for the high d15N values in the river nitrate. The d15N of algae in the San Joaquin reflects the high values of the nitrate in the river indicating (1) that the San Joaquin is productive despite its relatively high opacity, (2) that the algae use the nitrate as a primary nutrient source, and (3) that the concentrations of algae in the San Joaquin are not principally dependent on algae from the tributaries being flushed into the river as has been suggested. The sources of nitrate to the San Joaquin River must be identified if algae production is to be controlled and hypoxic conditions in the downstream reaches eliminated.

Distribution and condition of larval and juvenile Lost River and shortnose suckers in the Williamson River Delta restoration project and Upper Klamath Lake, Oregon

USGS Publications Warehouse

Burdick, Summer M.

2012-01-01

Federally endangered Lost River sucker (Deltistes luxatus) and shortnose sucker (Chasmistes brevirostris) were once abundant throughout their range but populations have declined. They were extirpated from several lakes in the 1920s and may no longer reproduce in other lakes. Poor recruitment to the adult spawning populations is one of several reasons cited for the decline and lack of recovery of these species and may be the consequence of high mortality during juvenile life stages. High larval and juvenile sucker mortality may be exacerbated by an insufficient quantity of suitable or high-quality rearing habitat. In addition, larval suckers may be swept downstream from suitable rearing areas in Upper Klamath Lake into Keno Reservoir, where they are assumed lost to Upper Klamath Lake populations. The Nature Conservancy flooded about 3,600 acres (1,456 hectares) to the north of the Williamson River mouth (Tulana) in October 2007, and about 1,400 acres (567 hectares) to the south and east of the Williamson River mouth (Goose Bay Farms) in October 2008, in order to retain larval suckers in Upper Klamath Lake, create nursery habitat, and improve water quality. The U.S. Geological Survey joined a long-term research and monitoring program in collaboration with The Nature Conservancy, the Bureau of Reclamation, and Oregon State University in 2008 to assess the effects of the Williamson River Delta restoration on the early life-history stages of Lost River and shortnose suckers. The primary objectives of the research were to describe habitat colonization and use by larval and juvenile suckers and non-sucker fishes and to evaluate the effects of the restored habitat on the health and condition of juvenile suckers. This report summarizes data collected in 2010 by the U.S. Geological Survey as a part of this monitoring effort and follows two annual reports on data collected in 2008 and 2009. Restoration modifications made to the Williamson River Delta appeared to provide additional suitable rearing habitat for endangered Lost River and shortnose suckers from 2008 to 2010 based on sucker catches. Mean larval sample density was greater for both species in the Williamson River Delta than adjacent lake habitats in all 3 years. In addition to larval suckers, at least three age classes of juvenile suckers were captured in the delta. The shallow Goose Bay Farms and Tulana Emergent were among the most used habitats by age-0 suckers in 2009. Both of these environments became inaccessible due to low water in 2010, however, and were not sampled after July 19, 2010. In contrast, age-1 sucker catches shifted from the shallow water (about 0.5-1.5 m deep) on the eastern side of the Williamson River Delta in May, to deeper water environments (greater than 2 m) by the end of June or early July in all 3 years. Differential distribution among sucker species within the Williamson River Delta and between the delta and adjacent lakes indicated that shortnose suckers likely benefited more from the restored Williamson River Delta than Lost River or Klamath largescale suckers (Catostomus snyderi). Catch rates in shallow-water habitats within the delta were higher for shortnose and Klamath largescale sucker larvae than for larval Lost River suckers in 2008, 2009, and 2010. Shortnose suckers also comprised the greatest portion of age-0 suckers captured in the Williamson River Delta in all 3 years of the study. The relative abundance of age-1 shortnose suckers was high in our catches compared to age-1 Lost River suckers in 2009 and 2010. The restored delta also created habitat for several piscivorous fishes, but only two appeared to pose a meaningful threat of predation to suckers - fathead minnows (Pimephales promelas) and yellow perch (Perca flavescens). Fathead minnows that prey on larval but not juvenile suckers dominated catches in all sampling areas. Yellow perch also were abundant throughout the study area, but based on their gape size and co-occurrence with suckers, most were only capable of preying on larvae. Low May lake-surface elevation, below average snow pack, and anticipated irrigation demands indicated late summer water levels in Upper Klamath Lake would be unusually low in 2010. In response to concerns by the Fish and Wildlife Service and The Nature Conservancy that low-water conditions might strand fish on the delta, low water seine surveys were implemented. Eleven fishes, including both endangered suckers, were captured in seine surveys, including both species of suckers, which continued to use shallow water less than 0.4 m deep through September 21. Lake elevation declined to 1,261.54 m (4,138.9 feet) in mid-September 2010, but did not appear to strand fish or cause large-scale fish mortality.

Mississippi River channel response to the Bonnet Carré Spillway opening in the 2011 flood and its implications for the design and operation of river diversions

NASA Astrophysics Data System (ADS)

Allison, Mead A.; Vosburg, Brian M.; Ramirez, Michael T.; Meselhe, Ehab A.

2013-01-01

SummaryThe large Mississippi River flood in 2011 was notable in the lowermost Louisiana, USA reach for requiring operation of several flood control structures to reduce stress on artificial levees: the largest diversion went through the gated Bonnet Carré Spillway, which was opened for 42 days in May and June. The removal of approximately 20% of the total flood discharge from the river provided an opportunity to examine the impact of large water diversion on the sediment transport capacity of large rivers. Boat-based, acoustic and water and bed sampling surveys were conducted in the Mississippi River channel adjacent to the Spillway immediately prior to the opening of the structure, at full capacity, and immediately following (June 2011) and 1 year after (June 2012) closure. The surveys were designed to examine (1) elevation change of the channel bed due to scour or aggradation of sediment, and (2) suspended and bedload transport variability upriver and downriver of the Spillway. The results indicate that approximately 9.1 million tons of sand were deposited on the channel bed immediately downriver of the water exit pathway and extending at least 13 km downriver at a rapidly and progressively reducing magnitude per river kilometer. The surficial deposit was of finer grain size than the lateral sand bars in the channel upriver of the structure. We argue the deposit was largely delivered from suspension derived from the observed deflation of lateral bars upstream of the diversion point, rather than from sand arriving from the drainage basin. Approximately 69% of the 2011 flood deposit was removed from the 13 km downstream reach between June 2011 and June 2012. We conclude that the source of the channel deposit was the reduction in stream power, and, thus, in the sediment transport capacity of the Mississippi, associated with the water withdrawal. The re-entrainment of this material in the following flood year indicates the system rapidly re-establishes an equilibrium to pre-opening conditions. Future diversions in the river for coastal restoration will have to address this issue to maintain a deep draft navigation channel in the Mississippi River.

Snake River Plain Geothermal Play Fairway Analysis - Phase 1 KMZ files

DOE Data Explorer

John Shervais

2015-10-10

This dataset contain raw data files in kmz files (Google Earth georeference format). These files include volcanic vent locations and age, the distribution of fine-grained lacustrine sediments (which act as both a seal and an insulating layer for hydrothermal fluids), and post-Miocene faults compiled from the Idaho Geological Survey, the USGS Quaternary Fault database, and unpublished mapping. It also contains the Composite Common Risk Segment Map created during Phase 1 studies, as well as a file with locations of select deep wells used to interrogate the subsurface.

Rare Earth Element and Trace Element Data Associated with Hydrothermal Spring Reservoir Rock, Idaho

DOE Data Explorer

Quillinan, Scott; Bagdonas, Davin

2017-06-22

These data represent rock samples collected in Idaho that correspond with naturally occurring hydrothermal samples that were collected and analyzed by INL (Idaho Falls, ID). Representative samples of type rocks were selected to best represent the various regions of Idaho in which naturally occurring hydrothermal waters occur. This includes the Snake River Plain (SRP), Basin and Range type structures east of the SRP, and large scale/deep seated orogenic uplift of the Sawtooth Mountains, ID. Analysis includes ICP-OES and ICP-MS methods for Major, Trace, and REE concentrations.

Chemistry Data for Geothermometry Mapping of Deep Hydrothermal Reservoirs in Southeastern Idaho

DOE Data Explorer

Earl Mattson

2016-01-18

This dataset includes chemistry of geothermal water samples of the Eastern Snake River Plain and surrounding area. The samples included in this dataset were collected during the springs and summers of 2014 and 2015. All chemical analysis of the samples were conducted in the Analytical Laboratory at the Center of Advanced Energy Studies in Idaho Falls, Idaho. This data set supersedes #425 submission and is the final submission for AOP 3.1.2.1 for INL. Isotopic data collected by Mark Conrad will be submitted in a separate file.

Chemical constituents in groundwater from multiple zones in the eastern Snake River Plain aquifer, Idaho National Laboratory, Idaho, 2009-13

USGS Publications Warehouse

Bartholomay, Roy C.; Hopkins, Candice B.; Maimer, Neil V.

2015-01-01

Tritium concentrations in relation to basaltic flow units indicate the presence of wastewater influence in multiple basalt flow groups; however, tritium is most abundant in the South Late Matuyama flow group in the southern boundary wells. The concentrations of wastewater constituents in deep zones in wells Middle 2051, USGS 132, USGS 105, and USGS 103 support the concept of groundwater flow deepening in the southwestern corner of the INL, as indicated by the INL groundwater-flow model.

Bug Hill: Excavation of a Multicomponent Midden Mound in the Jackfork Valley, Pushmataha County, Southeast Oklahoma.

DTIC Science & Technology

1983-11-25

program of survey and excavation on at least 24 sites, 18 of which were black midden mounds, along the Poteau River and Fourche Maline Creek in the area of...evidence, from the Fourche Maline Creek sites. These are deep sites with four feet or more of midden... Evidently, it was not possible to separate this... Maline Creek 15 to 20 mi west of present Wister Lake. At this site, Powell and Rodgers (1980:5-9) carefully examined the stratigraphic context of each

Passive acoustic monitoring to detect spawning in large-bodied catostomids

USGS Publications Warehouse

Straight, Carrie A.; Freeman, Byron J.; Freeman, Mary C.

2014-01-01

Documenting timing, locations, and intensity of spawning can provide valuable information for conservation and management of imperiled fishes. However, deep, turbid or turbulent water, or occurrence of spawning at night, can severely limit direct observations. We have developed and tested the use of passive acoustics to detect distinctive acoustic signatures associated with spawning events of two large-bodied catostomid species (River Redhorse Moxostoma carinatum and Robust Redhorse Moxostoma robustum) in river systems in north Georgia. We deployed a hydrophone with a recording unit at four different locations on four different dates when we could both record and observe spawning activity. Recordings captured 494 spawning events that we acoustically characterized using dominant frequency, 95% frequency, relative power, and duration. We similarly characterized 46 randomly selected ambient river noises. Dominant frequency did not differ between redhorse species and ranged from 172.3 to 14,987.1 Hz. Duration of spawning events ranged from 0.65 to 11.07 s, River Redhorse having longer durations than Robust Redhorse. Observed spawning events had significantly higher dominant and 95% frequencies than ambient river noises. We additionally tested software designed to automate acoustic detection. The automated detection configurations correctly identified 80–82% of known spawning events, and falsely indentified spawns 6–7% of the time when none occurred. These rates were combined over all recordings; rates were more variable among individual recordings. Longer spawning events were more likely to be detected. Combined with sufficient visual observations to ascertain species identities and to estimate detection error rates, passive acoustic recording provides a useful tool to study spawning frequency of large-bodied fishes that displace gravel during egg deposition, including several species of imperiled catostomids.

Fine-grained channel margin (FGCM) deposits conditioned by Large Woody Debris (LWD) in a gravel-bed river

NASA Astrophysics Data System (ADS)

Skalak, K. J.; Pizzuto, J. E.

2006-12-01

The purpose of this research is to examine the origin, occurrence, persistence, residence time and general significance of fine-grained channel margin storage in South River, a steep gravel-bedded stream in western Virginia. Fine-grained channel margin (FGCM) deposits in this study refers to specific in-channel deposits of mud and sand. These deposits occur primarily in the margins and near-banks regions of the channel. Fine- grained sediment storage in the near-bank regions is a result of reduced velocity caused by the bank obstructions. Nearly all of these obstructions consist of LWD accumulations in the channel. Storage occurs in four different geomorphic settings: 1) long pooled sections caused by bedrock or old mill dams, 2) the upstream ends of pools in channel margins with LWD accumulations, 3) bank obstructions usually caused by trees, 4) side channel backwaters where flow separates around islands. In approximately 38 km of river, there is 3000 m3 of fine-grained sediment stored in these features. The channel stores approximately 15 percent its total annual suspended load as fine-grained channel margin deposits. Consequently, these features represent a significant component of an annual sediment budget for this river. On average, the FGCM deposits are about 35 cm deep, 20 m long, and 4 m wide. They average 30 percent mud, 68 percent sand, and 2 percent gravel. These deposits have been cored and analyzed for Hg, grain size, loss-on-ignition, and bomb radiocarbon. Results from bomb radiocarbon analysis indicate that these features have an average age of 13 years. High Hg concentrations in fish tissue are an ongoing problem along South River, further motivating detailed study of these deposits.

Assessing the contribution of wetlands and subsided islands to dissolved organic matter and disinfection byproduct precursors in the Sacramento-San Joaquin River Delta: A geochemical approach

USGS Publications Warehouse

Kraus, T.E.C.; Bergamaschi, B.A.; Hernes, P.J.; Spencer, R.G.M.; Stepanauskas, R.; Kendall, C.; Losee, R.F.; Fujii, R.

2008-01-01

This study assesses how rivers, wetlands, island drains and open water habitats within the Sacramento-San Joaquin River Delta affect dissolved organic matter (DOM) content and composition, and disinfection byproduct (DBP) formation. Eleven sites representative of these habitats were sampled on six dates to encompass seasonal variability. Using a suite of qualitative analyses, including specific DBP formation potential, absorbance, fluorescence, lignin content and composition, C and N stable isotopic compositions, and structural groupings determined using CPMAS (cross polarization, magic angle spinning) 13C NMR, we applied a geochemical fingerprinting approach to characterize the DOM from different Delta habitats, and infer DOM and DBP precursor sources and estimate the relative contribution from different sources. Although river input was the predominant source of dissolved organic carbon (DOC), we observed that 13-49% of the DOC exported from the Delta originated from sources within the Delta, depending on season. Interaction with shallow wetlands and subsided islands significantly increased DOC and DBP precursor concentrations and affected DOM composition, while deep open water habitats had little discernable effect. Shallow wetlands contributed the greatest amounts of DOM and DBP precursors in the spring and summer, in contrast to island drains which appeared to be an important source during winter months. The DOM derived from wetlands and island drains had greater haloacetic acid precursor content relative to incoming river water, while two wetlands contributed DOM with greater propensity to form trihalomethanes. These results are pertinent to restoration of the Delta. Large scale introduction of shallow wetlands, a proposed restoration strategy, could alter existing DOC and DBP precursor concentrations, depending on their hydrologic connection to Delta channels. ?? 2008 Elsevier Ltd.

Diet and habitat use by age-0 deepwater sculpins in northern Lake Huron, Michigan and the Detroit River

USGS Publications Warehouse

Roseman, Edward F.

2014-01-01

Deepwater sculpins (Myoxocephalus thompsonii) are an important link in deepwater benthic foodwebs of the Great Lakes. Little information exists about deepwater sculpin spawning habits and early life history ecology due to difficulty in sampling deep offshore habitats. Larval and age-0 deepwater sculpins collected in northern Lake Huron and the Detroit River during 2007 were used to improve our understanding of their habitat use, diet, age, and growth. Peak larval density reached 8.4/1000 m3 in the Detroit River during April and was higher than that in Lake Huron. Offshore bottom trawls at DeTour and Hammond Bay first collected benthic age-0 deepwater sculpins in early September when fish were ≥ 25 mm TL. Otolith analysis revealed that hatch dates for pelagic larvae occurred during late March and larvae remained pelagic for 40 to 60 days. Diet of pelagic larvae (10–21 mm TL) was dominated by calanoid copepods at all sample locations. Diets of benthic age-0 fish varied by location and depth: Mysis and chironomids were prevalent in fish from Hammond Bay and the 91 m site at DeTour, but only chironomids were found in fish from the 37 m DeTour site. This work showed that nearshore epilimnetic sites were important for pelagic larvae and an ontogenetic shift from pelagic planktivore to benthivore occurred at about 25 mm TL in late summer. Age analysis showed that larvae remained pelagic long enough to be transported through the St. Clair–Detroit River system, Lake Erie, and the Niagara River, potentially contributing to populations in Lake Ontario.

Using 87Sr/86Sr ratios to investigate changes in stream chemistry during snowmelt in the Provo River, Utah, USA

NASA Astrophysics Data System (ADS)

Hale, C. A.; Carling, G. T.; Fernandez, D. P.; Nelson, S.; Aanderud, Z.; Tingey, D. G.; Dastrup, D.

2017-12-01

Water chemistry in mountain streams is variable during spring snowmelt as shallow groundwater flow paths are activated in the watershed, introducing solutes derived from soil water. Sr isotopes and other tracers can be used to differentiate waters that have interacted with soils and dust (shallow groundwater) and bedrock (deep groundwater). To investigate processes controlling water chemistry during snowmelt, we analyzed 87Sr/86Sr ratios, Sr and other trace element concentrations in bulk snowpack, dust, soil, soil water, ephemeral channels, and river water during snowmelt runoff in the upper Provo River watershed in northern Utah, USA, over four years (2014-2017). Strontium concentrations in the river averaged 20 ppb during base flow and decreased to 10 ppb during snowmelt runoff. 87Sr/86Sr ratios were around 0.717 during base flow and decreased to 0.715 in 2014 and 0.713 in 2015 and 2016 during snowmelt, trending towards less radiogenic values of mineral dust inputs in the Uinta Mountain soils. Ephemeral channels, representing shallow flow paths with soil water inputs, had Sr concentrations between 7-20 ppb and 87Sr/86Sr ratios between 0.713-0.716. Snowpack Sr concentrations were generally <2 ppb with 87Sr/86Sr ratios between 0.710-711, similar to atmospheric dust inputs. The less radiogenic 87Sr/86Sr ratios and lower Sr concentrations in the river during snowmelt are likely a result of activating shallow groundwater flow paths, which allows melt water to interact with shallow soils that contain accumulated dust deposits with a less radiogenic 87Sr/86Sr ratio. These results suggest that flow paths and atmospheric dust are important to consider when investigating variable solute loads in mountain streams.

Criteria for reducing predation by northern squawfish near juvenile salmonid bypass outfalls at Columbia River dams

USGS Publications Warehouse

Shively, Rip S.; Poe, Thomas P.; Sheer, Mindi B.; Peters, Rock

1996-01-01

Predation by northern squawfish (Ptychocheilus oregonensis) has been documented to be significant on emigrating juvenile salmonids near juvenile bypass outfalls at hydroelectric dams on the Columbia River. Criteria for siting juvenile fish bypass outfalls to reduce predation were developed using locational data from radio-tagged northern squawfish in The Dalles Dam trailrace, Columbia River. Radio transmitters were surgically implanted in 164 northern squawfish in 1993 and 1994, and their movements and distribution were monitored. Position estimates of northern squawfish were compared with data from a physical hydraulic model of the dam to estimate water velocities where northern squawfish were located. Eighty-two percent of northern squawfish position estimates were in water velocities ≤110 cm/s in 1993 and ≤90 cm/s in 1994. Fish locations were usually associated with water depths ≤10 m (84% in 1993 and 82% in 1994); 90% were within 110 m of the shore or dam structure in 1993, and 86% were within 80 m in 1994. In a related study at John Day Dam, Columbia River, where the juvenile bypass outfall is located 40 m from shore, water depth is 10 m and water velocities typically exceed 75 cm/s, only 13 of 1443 (0.9%) contacts on radio-tagged northern squawfish were located within 200 m of the bypass outfall. We recommend that new or modified juvenile bypass outfalls on the Columbia River be located in water velocities of ≥100 cm/s, ≥75 m from the shore or dam structure, and in water ≥10 m deep.

Constraints on mantle melt geometries from body wave attenuation in the Salton Trough and Snake River Plain

NASA Astrophysics Data System (ADS)

Byrnes, J. S.; Bezada, M.

2017-12-01

Melt can be retained in the mantle at triple junctions between grain boundaries, be spread in thin films along two-grain boundaries, or be organized by shear into elongate melt-rich bands. Which of these geometries is most prevalent is unknown. This ambiguity makes the interpretation of anomalous seismic velocities and quality factors difficult, since different geometries would result in different mechanical effects. Here, we compare observations of seismic attenuation beneath the Salton Trough and the Snake River Plain; two regions where the presence of melt has been inferred. The results suggest that seismic attenuation is diagnostic of melt geometry. We measure the relative attenuation of P waves from deep focus earthquakes using a time-domain method. Even though the two regions are underlain by comparably strong low-velocity anomalies, their attenuation signature is very different. The upper mantle beneath the Salton Trough is sufficiently attenuating that the presence of melt must lower Qp, while attenuation beneath the Snake River Plain is not anomalous with respect to surrounding regions. These seemingly contradictory results can be reconciled if different melt geometries characterize each region. SKS splitting from the Salton Trough suggests that melt is organized into melt-rich bands, while this is not the case for the Snake River Plain. We infer that beneath the Snake River Plain melt is retained at triple junctions between grain boundaries, a geometry that is not predicted to cause seismic attenuation. More elongate geometries beneath the Salton Trough may cause seismic attenuation via the melt-squirt mechanism. In light of these results, we conclude that prior observations of low seismic velocities with somewhat high quality factors beneath the East Pacific Rise and Southern California suggest that melt does not organize into elongate bands across much of the asthenosphere.

The Geomorphometrics of the Rio Grande Rift: The role of tectonics, climate, and erosional processes in forming the Rio Grande river

NASA Astrophysics Data System (ADS)

Berry, M. A.; van Wijk, J.; Emry, E.; Axen, G. J.; Coblentz, D. D.

2016-12-01

Geomorphometrics provides a powerful tool for quantifying the topographic fabric of a landscape and can help with correlating surface features with underlying dynamic processes. Here we use a suite of geomorphometric metrics (including the topographic power spectra, fabric orientation/organization) to compare and contrast the geomorphology of two of the world's major rifts, the Rio Grande Rift (RGR) in western US and the East Africa Rift (EAR). The motivation for this study is the observation of fundamental differences between the characteristics of the intra-rift river drainage for the two rifts. The RGR consists of a series of NS trending rift basins, connected by accommodation or transfer zones. The Rio Grande river developed in the late Neogene, and follows these rift segments from the San Luis basin in Colorado to the Gulf of Mexico. Before the river system formed, basins are thought to have formed internally draining systems, characterized by shallow playa lakes. This is in contrast with lakes in the Tanganyika and Malawi rifts of the East African Rift that are deep and have existed for >5 My. We investigate the role of climate, tectonics and erosional processes in the formation of the through-going Rio Grande river. This occurred around the time of a slowing down of rift opening ( 10 Ma), but also climatic changes in the southwestern U.S. have been described for the late Neogene. To model our hypothesis, a tectonics and surface transport code TISC (Transport, Isostasy, Surface Transport, Climate) was used to evaluate the dynamics of a series of proto-rift basins and their connecting accommodation zones. Basin infill and drainage system development are studied as a result of varying sediment budgets, climate variables, and rift opening rate.

Geophysical constraints on the Virgin River Depression, Nevada, Utah, and Arizona

USGS Publications Warehouse

Langenheim, V.E.; Glen, J.M.; Jachens, R.C.; Dixon, G.L.; Katzer, T.C.; Morin, R.L.

2000-01-01

Gravity and aeromagnetic data provide insights into the subsurface lithology and structure of the Virgin River Depression (VRD) of Nevada, Utah, and Arizona. The gravity data indicate that the Quaternary and Tertiary sedimentary deposits hide a complex pre-Cenozoic surface. A north-northwest-trending basement ridge separates the Mesquite and Mormon basins, as evidenced by seismic-reflection, gravity, and aeromagnetic data. The Mesquite basin is very deep, reaching depths of 8?10 km. The Mormon basin reaches thicknesses of 5 km. Its northern margin is very steep and may be characterized by right steps, although this interpretation could change with additional gravity stations. Most of the young (Quaternary), small-displacement faults trend within 10? of due north and occur within the deeper parts of the Mesquite basin north of the Virgin River. South of the Virgin River, only a few, young, small-displacement faults are mapped; the trend of these faults is more northeasterly and parallels the basement topography and is distinct from that of the faults to the north. The Virgin River appears to follow the margin of the basin as it emerges from the plateau. The high-resolution aeromagnetic data outline the extent of shallow volcanic rocks in the Mesquite basin. The north-northwest alignment of volcanic rocks east of Toquop Wash appear to be structurally controlled because of faults imaged on seismic-reflection profiles and because the alignment is nearly perpendicular to the direction of Cenozoic extension. More buried volcanics likely exist to the north and east of the high-resolution aeromagnetic survey. Broader aeromagnetic anomalies beneath pre-Cenozoic basement in the Mormon Mountains and Tule Springs Hills reflect either Precambrian basement or Tertiary intrusions. These rocks are probably barriers to groundwater flow, except where fractured.

Velocity mapping in the Lower Congo River: a first look at the unique bathymetry and hydrodynamics of Bulu Reach

USGS Publications Warehouse

Jackson, P. Ryan; Oberg, Kevin A.; Gardiner, Ned; Shelton, John

2009-01-01

The lower Congo River is one of the deepest, most powerful, and most biologically diverse stretches of river on Earth. The river’s 270 m decent from Malebo Pool though the gorges of the Crystal Mountains to the Atlantic Ocean (498 km downstream) is riddled with rapids, cataracts, and deep pools. Much of the lower Congo is a mystery from a hydraulics perspective. However, this stretch of the river is a hotbed for biologists who are documenting evolution in action within the diverse, but isolated, fish populations. Biologists theorize that isolation of fish populations within the lower Congo is due to barriers presented by flow structure and bathymetry. To investigate this theory, scientists from the U.S. Geological Survey and American Museum of Natural History teamed up with an expedition crew from National Geographic in 2008 to map flow velocity and bathymetry within target reaches in the lower Congo River using acoustic Doppler current profilers (ADCPs) and echo sounders. Simultaneous biological and water quality sampling was also completed. This paper presents some preliminary results from this expedition, specifically with regard to the velocity structure andbathymetry. Results show that the flow in the bedrock controlled Bulu reach of the lower Congo is highly energetic. Turbulent and secondary flow structures can span the full depth of flow (up to 165 m), while coherent bank-to-bank cross-channel flow structures are absent. Regions of flow separation near the banks are isolated from one another and from the opposite bank by high shear, high velocity zones with depth-averaged flow velocities that can exceed 4 m/s.

Riverine Response of Sulfate to Declining Atmospheric Sulfur Deposition in Agricultural Watersheds.

PubMed

David, Mark B; Gentry, Lowell E; Mitchell, Corey A

2016-07-01

Sulfur received extensive study as an input to terrestrial ecosystems from acidic deposition during the 1980s. With declining S deposition inputs across the eastern United States, there have been many studies evaluating ecosystem response, with the exception of agricultural watersheds. We used long-term (22 and 18 yr) sulfate concentration data from two rivers and recent (6 yr) data from a third river to better understand cycling and transport of S in agricultural, tile-drained watersheds. Sulfate concentrations and yields steadily declined in the Embarras (from ∼10 to 6 mg S L) and Kaskaskia rivers (from 7 to 3.5 mg S L) during the sampling period, with an overall -23.1 and -12.8 kg S ha yr balance for the two watersheds. There was evidence of deep groundwater inputs of sulfate in the Salt Fork watershed, with a much smaller input to the Embarras and none to the Kaskaskia. Tiles in the watersheds had low sulfate concentrations (<10 mg S L), similar to the Kaskaskia River, unless the field had received some form of S fertilizer. A multiple regression model of runoff (cm) and S deposition explained much of the variation in Embarras River sulfate ( = 0.86 and 0.80 for concentrations and yields; = 46). Although atmospheric deposition was much less than outputs (grain harvest + stream export of sulfate), riverine transport of sulfate reflected the decline in inputs. Watershed S balances suggest a small annual depletion of soil organic S pools, and S fertilization will likely be needed at some future date to maintain crop yields. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Coupled SWAT-MODFLOW Model Development for Large Basins

NASA Astrophysics Data System (ADS)

Aliyari, F.; Bailey, R. T.; Tasdighi, A.

2017-12-01

Water management in semi-arid river basins requires allocating water resources between urban, industrial, energy, and agricultural sectors, with the latter competing for necessary irrigation water to sustain crop yield. Competition between these sectors will intensify due to changes in climate and population growth. In this study, the recently developed SWAT-MODFLOW coupled hydrologic model is modified for application in a large managed river basin that provides both surface water and groundwater resources for urban and agricultural areas. Specific modifications include the linkage of groundwater pumping and irrigation practices and code changes to allow for the large number of SWAT hydrologic response units (HRU) required for a large river basin. The model is applied to the South Platte River Basin (SPRB), a 56,980 km2 basin in northeastern Colorado dominated by large urban areas along the front range of the Rocky Mountains and agriculture regions to the east. Irregular seasonal and annual precipitation and 150 years of urban and agricultural water management history in the basin provide an ideal test case for the SWAT-MODFLOW model. SWAT handles land surface and soil zone processes whereas MODFLOW handles groundwater flow and all sources and sinks (pumping, injection, bedrock inflow, canal seepage, recharge areas, groundwater/surface water interaction), with recharge and stream stage provided by SWAT. The model is tested against groundwater levels, deep percolation estimates, and stream discharge. The model will be used to quantify spatial groundwater vulnerability in the basin under scenarios of climate change and population growth.

Influence of Introgression and Geological Processes on Phylogenetic Relationships of Western North American Mountain Suckers (Pantosteus, Catostomidae)

PubMed Central

Unmack, Peter J.; Dowling, Thomas E.; Laitinen, Nina J.; Secor, Carol L.; Mayden, Richard L.; Shiozawa, Dennis K.; Smith, Gerald R.

2014-01-01

Intense geological activity caused major topographic changes in Western North America over the past 15 million years. Major rivers here are composites of different ancient rivers, resulting in isolation and mixing episodes between river basins over time. This history influenced the diversification of most of the aquatic fauna. The genus Pantosteus is one of several clades centered in this tectonically active region. The eight recognized Pantosteus species are widespread and common across southwestern Canada, western USA and into northern Mexico. They are typically found in medium gradient, middle-elevation reaches of rivers over rocky substrates. This study (1) compares molecular data with morphological and paleontological data for proposed species of Pantosteus, (2) tests hypotheses of their monophyly, (3) uses these data for phylogenetic inferences of sister-group relationships, and (4) estimates timing of divergence events of identified lineages. Using 8055 base pairs from mitochondrial DNA protein coding genes, Pantosteus and Catostomus are reciprocally monophyletic, in contrast with morphological data. The only exception to a monophyletic Pantosteus is P. columbianus whose mtDNA is closely aligned with C. tahoensis because of introgression. Within Pantosteus, several species have deep genetic divergences among allopatric sister lineages, several of which are diagnosed and elevated to species, bringing the total diversity in the group to 11 species. Conflicting molecular and morphological data may be resolved when patterns of divergence are shown to be correlated with sympatry and evidence of introgression. PMID:24619087

Mitigating flood exposure: Reducing disaster risk and trauma signature.

PubMed

Shultz, James M; McLean, Andrew; Herberman Mash, Holly B; Rosen, Alexa; Kelly, Fiona; Solo-Gabriele, Helena M; Youngs, Georgia A; Jensen, Jessica; Bernal, Oscar; Neria, Yuval

2013-01-01

Introduction. In 2011, following heavy winter snowfall, two cities bordering two rivers in North Dakota, USA faced major flood threats. Flooding was foreseeable and predictable although the extent of risk was uncertain. One community, Fargo, situated in a shallow river basin, successfully mitigated and prevented flooding. For the other community, Minot, located in a deep river valley, prevention was not possible and downtown businesses and one-quarter of the homes were inundated, in the city's worst flood on record. We aimed at contrasting the respective hazards, vulnerabilities, stressors, psychological risk factors, psychosocial consequences, and disaster risk reduction strategies under conditions where flood prevention was, and was not, possible. Methods . We applied the "trauma signature analysis" (TSIG) approach to compare the hazard profiles, identify salient disaster stressors, document the key components of disaster risk reduction response, and examine indicators of community resilience. Results . Two demographically-comparable communities, Fargo and Minot, faced challenging river flood threats and exhibited effective coordination across community sectors. We examined the implementation of disaster risk reduction strategies in situations where coordinated citizen action was able to prevent disaster impact (hazard avoidance) compared to the more common scenario when unpreventable disaster strikes, causing destruction, harm, and distress. Across a range of indicators, it is clear that successful mitigation diminishes both physical and psychological impact, thereby reducing the trauma signature of the event. Conclusion . In contrast to experience of historic flooding in Minot, the city of Fargo succeeded in reducing the trauma signature by way of reducing risk through mitigation.

Mitigating flood exposure

PubMed Central

Shultz, James M; McLean, Andrew; Herberman Mash, Holly B; Rosen, Alexa; Kelly, Fiona; Solo-Gabriele, Helena M; Youngs Jr, Georgia A; Jensen, Jessica; Bernal, Oscar; Neria, Yuval

2013-01-01

Introduction. In 2011, following heavy winter snowfall, two cities bordering two rivers in North Dakota, USA faced major flood threats. Flooding was foreseeable and predictable although the extent of risk was uncertain. One community, Fargo, situated in a shallow river basin, successfully mitigated and prevented flooding. For the other community, Minot, located in a deep river valley, prevention was not possible and downtown businesses and one-quarter of the homes were inundated, in the city’s worst flood on record. We aimed at contrasting the respective hazards, vulnerabilities, stressors, psychological risk factors, psychosocial consequences, and disaster risk reduction strategies under conditions where flood prevention was, and was not, possible. Methods. We applied the “trauma signature analysis” (TSIG) approach to compare the hazard profiles, identify salient disaster stressors, document the key components of disaster risk reduction response, and examine indicators of community resilience. Results. Two demographically-comparable communities, Fargo and Minot, faced challenging river flood threats and exhibited effective coordination across community sectors. We examined the implementation of disaster risk reduction strategies in situations where coordinated citizen action was able to prevent disaster impact (hazard avoidance) compared to the more common scenario when unpreventable disaster strikes, causing destruction, harm, and distress. Across a range of indicators, it is clear that successful mitigation diminishes both physical and psychological impact, thereby reducing the trauma signature of the event. Conclusion. In contrast to experience of historic flooding in Minot, the city of Fargo succeeded in reducing the trauma signature by way of reducing risk through mitigation. PMID:28228985

Distribution of dissolved and labile particulate trace metals in the overlying bottom water in the Vistula River plume (southern Baltic Sea).

PubMed

Sokolowski, A; Wolowicz, M; Hummel, H

2001-10-01

Overlying bottom water samples were collected in the Vistula River plume, southern Baltic Sea, (Poland) and analysed for dissolved and labile particulate (1 M HCl extractable) Cu, Pb, Zn, Mn, Fe and Ni, hydrological parameters being measured simultaneously. Particulate organic matter (POM), chlorophyll a and dissolved oxygen are key factors governing the chemical behaviour of the measured metal fractions. For the dissolved Cu, Pb, Zn, Fe and Ni two maxima, in the shallow and in the deeper part of the river plume, were found. In the shallow zone desorption from seaward fluxing metal-rich riverine particles account for markedly increased metal concentrations, as confirmed also by high particulate metal contents. For Pb, atmospheric inputs were also considered to have contributed to the elevated concentrations of dissolved Pb adjacent to the river mouth. In the deep zone desorption from detrital and/or resuspended particles by aerobic decomposition of organic material may be the main mechanism responsible for enrichment of particle-reactive metals (Cu, Pb, Zn) in the overyling bottom waters. The increased concentrations of dissolved Fe may have been due to reductive dissolution of Fe oxyhydroxides within the deep sediments by which dissolved Ni was released to the water. The distribution of Mn was related to dissolved oxygen concentrations, indicating that Mn is released to the water column under oxygen reduced conditions. However, Mn transfer to the dissolved phase from anoxic sediments in deeper part of the Vistula plume was hardly evidenced suggesting that benthic flux of Mn occurs under more severe reductive regime than is consistent with mobilization of Fe. Behaviour of Mn in a shallower part has been presumably affected by release from porewaters and by oxidization into less soluble species resulting in seasonal removal of this metal (e.g. in April) from the dissolved phase. The particulate fractions represented from about 6% (Ni) and 33% (Mn, Zn, Cu) to 80% (Fe) and 89% (Pb) of the total (labile particulate plus dissolved) concentrations. The affinity of the metals for particulate matter decreased in the following order: Pb > Fe > Zn > or = > Cu > Mn > Ni. Significant relationships between particulate Pb-Zn-Cu reflected the affinity of these metals for organic matter, and the significant relationship between Ni-Fe reflected the adsorption of Ni onto Fe-Mn oxyhydroxides. A comparison of metal concentrations with data from other similar areas revealed that the river plume is somewhat contaminated with Cu, Pb and Zn which is in agreement with previous findings on anthropogenic origin of these metals in the Polish zone of southern Baltic Sea.

To the restoration of the washed-out sea coast of the city Poti

NASA Astrophysics Data System (ADS)

Gagoshidze, Shalva; Kodua, Manoni

2017-04-01

Large-scale geomorphological changes in the coast area of the Poti city (the main port city on the Georgian Black Sea coast) started to occur after 1939 when the course of the Rioni river (with a maximum discharge up to 4000 m3 /s) was completely diverted northwards from the city. Though this diversion protected the city from frequent floods, it at the same time created an irreversible deficit of beach-forming alluvia and, as a result, the sea coast of Poti was irreparably washed out by sea waves and its area diminished by hundreds of meters. To restore the washed-out sea coast of Poti, in 1959, the dam with a regulator (sluice) was built across the Rioni river, at the 7th kilometer to the north-east of Poti. Its purpose was to divide the river flow so that a part (400 m3/s) of the river discharge would flow back to the former river bed (the so-called city channel) in order to compensate for a sediment deficit (600 m3 per year). However, for a variety of reasons, this measure did not lead to the desired result and the coast continued to be washed out. As shown by our theoretical studies based on the asymptotic solution of the problem of long wave invasion in river estuaries, one of the principal reasons for persistent washouts of the coast of Poti is the absence of the operation modes of spillway gates of the city channel: they should not be opened during sea storms, that is higher than 3(H), since in that case the alluvia transported by the city channel are completely lost in the deep sea canyon located far from the coast and do not serve for the coast restoration. Therefore, in stormy weather it is necessary to close the spillway gates of the city channel. Besides, it is necessary to clean the channel bed in order to increase its transportation capacity.

Assessing the utility of passive microwave data for Snow Water Equivalent (SWE) estimation in the Sutlej River Basin of the northwestern Himalaya

NASA Astrophysics Data System (ADS)

Brandt, T.; Bookhagen, B.; Dozier, J.

2014-12-01

Since 1978, space based passive microwave (PM) radiometers have been used to comprehensively measure Snow Water Equivalent (SWE) on a global basis. The ability of PM radiometers to directly measure SWE at high temporal frequencies offers some distinct advantages over optical remote sensors. Nevertheless, in mountainous terrain PM radiometers often struggle to accurately measure SWE because of wet snow, saturation in deep snow, forests, depth hoar and stratigraphy, variable relief, and subpixel heterogeneity inherent in large pixel sizes. The Himalaya, because of their high elevation and high relief—much above tree line—offer an opportunity to examine PM products in the mountains without the added complication of trees. The upper Sutlej River basin— the third largest Himalayan catchment—lies in the western Himalaya. The river is a tributary of the Indus River and seasonal snow constitutes a substantial part of the basin's hydrologic budget. The basin has a few surface stations and river gauges, which is unique for the region. As such, the Sutlej River basin is a good location to analyze the accuracy and effectiveness of the current National Snow and Ice Data Center's (NSIDC) standard AMSR-E/Aqua Daily SWE product in mountainous terrain. So far, we have observed that individual pixels can "flicker", i.e. fluctuate from day to day, over large parts of the basin. We consider whether this is an artifact of the algorithm or whether this is embedded in the raw brightness temperatures themselves. In addition, we examine how well the standard product registers winter storms, and how it varies over heavily glaciated pixels. Finally, we use a few common measures of algorithm performance (precision, recall and accuracy) to test how well the standard product detects the presence of snow, using optical imagery for validation. An improved understanding of the effectiveness of PM imagery in the mountains will help to clarify the technology's limits.

Salmonids, stream temperatures, and solar loading--modeling the shade provided to the Klamath River by vegetation and geomorphology

USGS Publications Warehouse

Forney, William M.; Soulard, Christopher E.; Chickadel, C. Christopher

2013-01-01

The U.S. Geological Survey is studying approaches to characterize the thermal regulation of water and the dynamics of cold water refugia. High temperatures have physiological impacts on anadromous fish species. Factors affecting the presence, variability, and quality of thermal refugia are known, such as riverine and watershed processes, hyporheic flows, deep pools and bathymetric factors, thermal stratification of reservoirs, and other broader climatic considerations. This research develops a conceptual model and methodological techniques to quantify the change in solar insolation load to the Klamath River caused by riparian and floodplain vegetation, the morphology of the river, and the orientation and topographic characteristics of its watersheds. Using multiple scales of input data from digital elevation models and airborne light detection and ranging (LiDAR) derivatives, different analysis methods yielded three different model results. These models are correlated with thermal infrared imagery for ground-truth information at the focal confluence with the Scott River. Results from nonparametric correlation tests, geostatistical cross-covariograms, and cross-correlograms indicate that statistical relationships between the insolation models and the thermal infrared imagery exist and are significant. Furthermore, the use of geostatistics provides insights to the spatial structure of the relationships that would not be apparent otherwise. To incorporate a more complete representation of the temperature dynamics in the river system, other variables including the factors mentioned above, and their influence on solar loading, are discussed. With similar datasets, these methods could be applied to any river in the United States—especially those listed as temperature impaired under Section 303(d) of the Clean Water Act—or international riverine systems. Considering the importance of thermal refugia for aquatic species, these methods can help investigate opportunities for riparian restoration, identify problematic reaches unlikely to provide good habitat, and simulate changes to solar loading estimates from alternative landscape configurations.

Using chemical, hydrologic, and age dating analysis to delineate redox processes and flow paths in the riparian zone of a glacial outwash aquifer‐stream system

USGS Publications Warehouse

Puckett, Larry J.; Cowdery, Timothy K.; McMahon, Peter B.; Tornes, Lan H.; Stoner, Jeffrey D.

2002-01-01

A combination of chemical and dissolved gas analyses, chlorofluorocarbon age dating, and hydrologic measurements were used to determine the degree to which biogeochemical processes in a riparian wetland were responsible for removing NO3−from groundwaters discharging to the Otter Tail River in west central Minnesota. An analysis of river chemistry and flow data revealed that NO3− concentrations in the river increased in the lower half of the 8.3 km study reach as the result of groundwater discharge to the river. Groundwater head measurements along a study transect through the riparian wetland revealed a zone of groundwater discharge extending out under the river. On the basis of combined chemical, dissolved gas, age date, and hydrologic results, it was determined that water chemistry under the riparian wetland was controlled largely by upgradient groundwaters that followed flow paths up to 16 m deep and discharged under the wetland, creating a pattern of progressively older, more chemically reduced, low NO3− water the farther one progressed from the edge of the wetland toward the river. These findings pose challenges for researchers investigating biogeochemical processes in riparian buffer zones because the progressively older groundwaters entered the aquifer in earlier years when less NO3− fertilizer was being used. NO3− concentrations originally present in the groundwater had also decreased in the upgradient aquifer as a result of denitrification and progressively stronger reducing conditions there. The resulting pattern of decreasing NO3− concentrations across the riparian zone may be incorrectly interpreted as evidence of denitrification losses there instead of in the upgradient aquifer. Consequently, it is important to understand the hydrogeologic setting and age structure of the groundwaters being sampled in order to avoid misinterpreting biogeochemical processes in riparian zones.

Mass balance of emerging contaminants in the water cycle of a highly urbanized and industrialized area of Italy.

PubMed

Castiglioni, Sara; Davoli, Enrico; Riva, Francesco; Palmiotto, Marinella; Camporini, Paolo; Manenti, Angela; Zuccato, Ettore

2017-12-22

The occurrence of several classes of emerging contaminants (ECs) was assessed in the River Lambro basin, one of the most urbanized and industrialized areas of Italy. The study aims were to identify the main sources of ECs, quantify their amounts circulating in the water cycle, and study their fate in the aquatic environment. More than 80 ECs were selected among pharmaceuticals (PHARM), personal care products (PCPs), disinfectants (DIS), illicit drugs (IDs), perfluorinated compounds (PERF), alkylphenols and bisphenol A (Alk-BPA), and anthropogenic markers (AM). Specific analytical methods were developed for quantitative analysis based on solid phase extraction and liquid chromatography tandem mass spectrometry. ECs were measured in rivers upstream and downstream of the main city (Milan), and in untreated and treated wastewater from Milan to assess the contribution to river contamination, and in superficial and deep groundwater in the city area to study the relationship between river and groundwater contamination. Samples were collected in a two-year monitoring campaign. Almost all ECs were ubiquitous in untreated wastewater, at concentrations up to the μg/L range, and the most abundant classes were PHARM and AM. Removals during different wastewater treatment processes were studied and the most stable substances were PHARM, PCPs and PERF. The mass loads increased for all the classes of ECs along the River Lambro basin. A mass balance was done in the river basin and allowed to identify the main sources of contamination, which were domestic, from treated or untreated wastewater, for PHARM, PCPs and IDs, mainly industrial for PERF, and both industrial and domestic for Alk-BPA. The study of AM helped to identify direct discharges of untreated wastewater. A substantial contribution of surface water to groundwater contamination was observed. This study improves the knowledge on occurrence, sources and fate of multiple classes of ECs in a highly urbanized area providing useful information to help the establishment of EU regulations for ECs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sedimentation in Goose Pasture Tarn, 1965-2005, Breckenridge, Colorado

USGS Publications Warehouse

Elliott, John G.; Char, Stephen J.; Linhart, Samuel M.; Stephens, V. Cory; O'Neill, Gregory B.

2006-01-01

Goose Pasture Tarn, a 771-acre-foot reservoir in Summit County, Colorado, is the principal domestic water-storage facility for the Town of Breckenridge and collects runoff from approximately 42 square miles of the upper Blue River watershed. In the 40 years since the reservoir was constructed, deltaic deposits have accumulated at the mouths of two perennial streams that provide most of the inflow and sediment to the reservoir. The Blue River is a low-gradient braided channel and transports gravel- to silt-size sediment. Indiana Creek is a steep-gradient channel that transports boulder- to silt-size sediment. Both deltas are composed predominantly of gravel, sand, and silt, but silt has been deposited throughout the reservoir. In 2004, the U.S. Geological Survey, in cooperation with the Town of Breckenridge, began a study to determine the volume of accumulated sediment in Goose Pasture Tarn, the long-term sedimentation rate for the reservoir, and the particle-size and chemical characteristics of the sediment. Exposed delta deposits occupied 0.91 acre and had an estimated volume of 0.6 acre-foot in 2005. Aerial photographic analysis indicated both the Blue River and Indiana Creek deltas grew rapidly during time intervals that included larger-than-average annual flood peaks on the Blue River. Sediment-transport relations could not be developed for the Blue River or Indiana Creek because of minimal streamflow and infrequently observed sediment transport during the study; however, suspended-sediment loads ranged from 0.02 to 1.60 tons per day in the Blue River and from 0.06 to 1.55 tons per day in Indiana Creek. Bedload as a percentage of total load ranged from 9 to 27 percent. New reservoir stage-area and stage-capacity relations were developed from bathymetric and topographic surveys of the reservoir bed. The original 1965 reservoir bed topography and the accumulated sediment thickness were estimated from a seismic survey and manual probing. The surface area of Goose Pasture Tarn in 2005 was 66.4 acres, and the reservoir capacity was 771.1 acre-feet at a full-pool elevation of 9,886.4 feet. The 1965 surface area was 67.1 acres, and the reservoir capacity was 818.0 acre-feet, indicating that the reservoir surface area has decreased by 0.7 acre, or about 1.1 percent, and the reservoir capacity has decreased by 46.9 acre-feet, or about 5.7 percent over a 40-year period. Sediment thickness determined with seismic profiling ranged from 0 to 4.0 feet and averaged 0.7 foot, with lesser thicknesses in the deeper parts of the reservoir and greater thicknesses near the deltas. Probe-determined sediment thickness ranged from 1.0 to 4.4 feet and averaged 2.8 feet near the Blue River delta and ranged from 0.3 to 6.0 feet and averaged 3.6 feet near the Indiana Creek delta. Approximately 47.5 acre-feet of sediment has accumulated in Goose Pasture Tarn and in the Blue River and Indiana Creek deltas, or an average of 1.19 acre-feet per year. Sediment cores from several locations in the reservoir showed stratification, which is indicative of different depositional dates or mechanisms. Metal and trace-constituent levels from the cores were compared with three standards. Silver, cadmium, europium, lead, and zinc were present in greater concentrations than Southern Rocky Mountain background levels in four sediment cores, and cadmium, lead, and zinc levels also were equal to or exceeded the Threshold Effect Concentration standards. Lead exceeded the Probable Effect Concentration standard in silt from the Blue River delta and deep water near the north shore. Tin was present in greater concentrations than Southern Rocky Mountain background levels in deep water near the east shore, and chromium and copper levels were equal to or exceeded the Threshold Effect Concentration standards in these cores.

An examination of photoacclimatory responses of Zostera marina transplants along a depth gradient for transplant-site selection in a disturbed estuary

NASA Astrophysics Data System (ADS)

Li, Wen-Tao; Kim, Seung Hyeon; Kim, Jae Woo; Kim, Jong-Hyeob; Lee, Kun-Seop

2013-02-01

Growth and photosynthetic responses of Zostera marina transplants along a depth gradient were examined to determine appropriate transplanting areas for seagrass restoration. Seagrass Z. marina was once widely distributed in the Taehwa River estuary in southeastern Korea, but has disappeared since the 1960s due to port construction and large scale pollutant inputs from upstream industrial areas. Recently, water quality has been considerably improved as a result of effective sewage treatment, and the local government is attempting to restore Z. marina to the estuary. For seagrass restoration in this estuary, a pilot transplantation trial of Z. marina at three water depths (shallow: 0.5 m; intermediate: 1.5 m; deep: 2.5 m relative to MLLW) was conducted in November 2008. The transplant shoot density increased gradually at the intermediate and deep sites, whereas the transplants at the shallow site disappeared after 3 months. To find the optimal transplantation locations in this estuary, the growth and photosynthetic responses of the transplants along a depth gradient were examined for approximately 4 months following transplantation in March 2009. In the 2009 experimental transplantation trial, shoot density of transplants at the shallow site was significantly higher than those at the intermediate and deep sites during the first 3 months following transplantation, but rapidly decreased approximately 4 months after transplantation. The chlorophyll content, photosynthetic efficiency (α), and maximum quantum yield (Fv/Fm) of the transplants were significantly higher at the deep site than at the shallow site. Shoot size, biomass and leaf productivity were also significantly higher at the deep site than at the shallow site. Although underwater irradiance was significantly lower at the deep site than at the shallow site, transplants at the deep site were morphologically and physiologically acclimated to the low light. Transplants at the shallow site exhibited high mortality during the early period of transplantation perhaps due to high physical disturbances at the site, but transplants at the intermediate and deep sites showed higher growth through more efficient photosynthesis and morphological adaptation. Thus, the intermediate and deep sites (1.5-2.5 m relative to MLLW) appeared to be more appropriate seagrass transplantation sites in this estuary.

Nile damming as plausible cause of extinction and drop in abundance of deep-sea shrimp in the western Mediterranean over broad spatial scales

NASA Astrophysics Data System (ADS)

Cartes, J. E.; Maynou, F.; Fanelli, E.

2011-11-01

Greatly increased retention of flow in Nile River reservoirs was initiated in 1964, after completion of the Aswan High Dam, which induced important oceanographic changes in the Mediterranean Sea, including deep waters (below a depth of 150 m). Based on an analysis of data series starting in the 1940s/1950s, the giant red shrimp Aristaeomorpha foliacea has become locally extinct off of the Catalonian coasts (and elsewhere in the northwestern Mediterranean) at depths of 400-900 m, with a simultaneous and significant drop in the catches of red shrimp, Aristeus antennatus, in the second half of the 1960s. The extinction and sharp decline of deep-shrimp populations off Catalonian coast (at ca. 3200 km westwards from Nile Delta) followed the 1964 drop in Nile discharge with a delay of ca. 3-5 yrs (breakpoint analysis applied to data series). The breakpoints detected in the second half of 1960s both in Nile runoff and shrimps’ abundance were independent of climatic events in the study area (e.g. changes in NAO) and occurred before the increase in fishing effort off Catalonian coasts (breakpoint in 1973-1974). The Levantine Intermediate Water (LIW), inhabited by A. foliacea in the western Basin, had significant temperature (T) and salinity (S) increases in the 1950-1970 period, and Nile damming has contributed about 45% of the total S increase of Western Mediterranean deep-water masses from the 1960s to the late 1990s (Skliris and Lascaratos, 2004). This had to increase, for instance, LIW salinity at its formation site in the eastern Mediterranean. Nile damming was probably a triggering factor for the extinction/drop in abundance of deep-sea shrimp off Catalonian coasts.

Origin of the lethal gas burst from Lake Monoun, Cameroun

NASA Astrophysics Data System (ADS)

Sigurdsson, H.; Devine, J. D.; Tchua, F. M.; Presser, F. M.; Pringle, M. K. W.; Evans, W. C.

1987-03-01

On 15 August, 1984, a lethal gas burst issued from a submerged 96-m-deep crater in Lake Monoun in Cameroun, western Africa, killing 37 people. The event was associated with a landslide from the eastern crater rim, which slumped into deep water. Waters below 50 m are anoxic, dominated by high Fe 2+ (˜600 mg/l) and HCO 3- (≥ 1900 mg/l), anoxic and supersaturated with siderite, which is a major component of the crater floor sediments. The unusually high Fe 2+ levels are attributed to reduction of laterite-derived ferric iron gradually brought into the lake as loess and in river input. Sulfur compounds are below detection limits in both water and gas. Gases effervescing from depressurized deep waters are dominantly CO 2 with minor CH 4, having δ 13C of -7.18 and -54.8 per mil, respectively. Bacterial decomposition of organic matter may account for the methane, but 14C of lake water indicates that only 10% of the carbon is modern, giving an apparent age of 18,000 years. The dominant source of carbon is therefore attributed to long-term emission of CO 2 as volcanic exhalation from vents within the crater, which led to gradual build-up of HCO 3- in the lake. The density stratification of the lake may have been upset by an earthquake and underwater landslide on 15 August, which triggered overturn of the lake and caused nucleation of CO 2 in the deep water. The resultant ebullition of CO 2 from deep lake waters led to a gas burst at the surface and locally generated a water wave up to 5 m high. People travelling through the gas cloud were asphyxiated, presumably from CO 2, and suffered skin discoloration from unidentified components.

Origin of the lethal gas burst from Lake Monoun, Cameroun

USGS Publications Warehouse

Sigurdsson, Haraldur; Devine, J.D.; Tchua, F.M.; Presser, F.M.; Pringle, M.K.W.; Evans, William C.

1987-01-01

On 15 August, 1984, a lethal gas burst issued from a submerged 96-m-deep crater in Lake Monoun in Cameroun, western Africa, killing 37 people. The event was associated with a landslide from the eastern crater rim, which slumped into deep water. Waters below 50 m are anoxic, dominated by high Fe2+ (???600 mg/l) and HCO3- (??? 1900 mg/l), anoxic and supersaturated with siderite, which is a major component of the crater floor sediments. The unusually high Fe2+ levels are attributed to reduction of laterite-derived ferric iron gradually brought into the lake as loess and in river input. Sulfur compounds are below detection limits in both water and gas. Gases effervescing from depressurized deep waters are dominantly CO2 with minor CH4, having ??13C of -7.18 and -54.8 per mil, respectively. Bacterial decomposition of organic matter may account for the methane, but 14C of lake water indicates that only 10% of the carbon is modern, giving an apparent age of 18,000 years. The dominant source of carbon is therefore attributed to long-term emission of CO2 as volcanic exhalation from vents within the crater, which led to gradual build-up of HCO3- in the lake. The density stratification of the lake may have been upset by an earthquake and underwater landslide on 15 August, which triggered overturn of the lake and caused nucleation of CO2 in the deep water. The resultant ebullition of CO2 from deep lake waters led to a gas burst at the surface and locally generated a water wave up to 5 m high. People travelling through the gas cloud were asphyxiated, presumably from CO2, and suffered skin discoloration from unidentified components. ?? 1987.

Chlorine-36 tracing of salinity sources in the dry valleys of Victoria land, Antarctica

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

Carlson, C.A.; Phillips, F.M.; Elmore, D.

1990-02-01

Chlorine-36 was used to trace the origins of salts in six saline lakes in the Dry Valleys of Southern Victoria Land, Antarctica. Characteristic {sup 36}Cl signatures were estimated for the various potential chloride sources, which include atmospheric deposition, rock weathering, seawater, and deep ground water. {sup 36}Cl/Cl ratios were measured in natural waters and salts from the Dry Valleys. Dilute lake waters (Cl{sup {minus}} < 100 mg/l) were found to have {sup 36}Cl/Cl ratios in the range 100 {times} 10{sup {minus}15} to 1,700 {times} 10{sup {minus}15}, whereas saline waters (Cl{sup {minus}} > 1000 mg/l) had ratios in the range 9more » {times} 10{sup {minus}15} to 40 {times} 10{sup {minus}15}. Simple mixing models were employed to quantify the relative contributions of the various chloride sources to Lake Vanda and Don Juan Pond. These results show that Lake Vanda has received its chloride from both deep ground water and the Onyx River. Don Juan Pond has received nearly all its chloride from deep ground water, probably ultimately from rock-water interaction. Deep ground water is the principal sources of chloride to the lakes of Wright Valley. However, preliminary data suggest that marine-derived salts or relict sea water may be a significant sources of chloride to the lakes of Taylor Valley, implying a possible recent marine invasion that did not affect Wright Valley.« less

Conjunction of 2D and 3D modified flow solvers for simulating spatio-temporal wind induced hydrodynamics in the Caspian Sea

NASA Astrophysics Data System (ADS)

Zounemat-Kermani, Mohammad; Sabbagh-Yazdi, Saeed-Reza

2010-06-01

The main objective of this study is the simulation of flow dynamics in the deep parts of the Caspian Sea, in which the southern and middle deep regions are surrounded by considerable areas of shallow zones. To simulate spatio-temporal wind induced hydrodynamics in deep waters, a conjunctive numerical model consisting of a 2D depth average model and a 3D pseudo compressible model is proposed. The 2D model is applied to determine time dependent free surface oscillations as well as the surface velocity patterns and is conjunct to the 3D flow solver for computing three-dimensional velocity and pressure fields which coverage to steady state for the top boundary condition. The modified 2D and 3D sets of equations are conjunct considering interface shear stresses. Both sets of 2D and 3D equations are solved on unstructured triangular and tetrahedral meshes using the Galerkin Finite Volume Method. The conjunctive model is utilized to investigate the deep currents affected by wind, Coriolis forces and the river inflow conditions of the Caspian Sea. In this study, the simulation of flow field due to major winds as well as transient winds in the Caspian Sea during a period of 6 hours in the winter season has been conducted and the numerical results for water surface level are then compared to the 2D numerical results.

Source to sink evaluation of sediment routing in the Gulf of Alaska and Southeast Alaska: A thermochronometric perspective

NASA Astrophysics Data System (ADS)

Dunn, Catherine A.; Enkelmann, Eva; Ridgway, Kenneth D.; Allen, Wai K.

2017-03-01

In this study, we present a source to sink evaluation of sediment routing at the glaciated convergent margin in Southeast Alaska. We investigate the efficacy of thermochronology to record spatial and temporal exhumation patterns in synorogenic sediment using Neogene strata drilled by Integrated Ocean Drilling Program Expedition 341 in the Gulf of Alaska. We present 1641 and 529 new detrital zircon and apatite fission track ages, respectively, from strata deposited on the continental shelf, slope, and deep-sea fans. These data are compared to results from the proposed source terrains, including the St. Elias Mountains and new data from the Alsek River. We find that the offshore Bagley-Bering sediment contains grains recording cooling ages much older (80-35 Ma) than those reported from the St. Elias syntaxis (3-2 Ma), indicating that extreme rapid exhumation does not extend west of the Seward-Bagley divide. Data from the sediment on the continental shelf, slope, and proximal deep sea all yield similar results, suggesting the same general source region since 1.2 Ma and limited sediment mixing along this glaciated margin. Data from sediment in the distal deep sea show that extreme, rapid, and deep-seated exhumation was ongoing at 11-8 Ma. Overall, this study demonstrates the strengths and limitations of using detrital fission track thermochronology to understand sediment routing on a glaciated convergent margin and to record changes in exhumation rates over geologic time scales.

Polycyclic aromatic hydrocarbons (PAHs) in the water column and sediment core of Deep Bay, South China

NASA Astrophysics Data System (ADS)

Qiu, Yao-Wen; Zhang, Gan; Liu, Guo-Qing; Guo, Ling-Li; Li, Xiang-Dong; Wai, Onyx

2009-06-01

The levels of 15 polycyclic aromatic hydrocarbons (PAHs) were determined in seawater, suspended particulate matter (SPM), surface sediment and core sediment samples of Deep Bay, South China. The average concentrations Σ 15PAHs were 69.4 ± 24.7 ng l -1 in seawater, 429.1 ± 231.8 ng g -1 in SPM, and 353.8 ± 128.1 ng g -1 dry weight in surface sediment, respectively. Higher PAH concentrations were observed in SPM than in surface sediment. Temporal trend of PAH concentrations in core sediment generally increased from 1948 to 2004, with higher concentrations in top than in sub-surface, implying a stronger recent input of PAHs owing to the rapid economic development in Shenzhen. Compared with historical data, the PAH levels in surface sediment has increased, and this was further confirmed by the increasing trend of PAHs in the core sediment. Phenanthrene, fluoranthene and pyrene dominated in the PAH composition pattern profiles in the Bay. Compositional pattern analysis suggested that PAHs in the Deep Bay were derived from both pyrogenic and petrogenic sources, and diesel oil leakage, river runoff and air deposition may serve as important pathways for PAHs input to the Bay. Significant positive correlations between partition coefficient in surface sediment to that in water ( KOC) of PAH and their octanol/water partition coefficients ( KOW) were observed, suggesting that KOC of PAHs in sediment/water of Deep Bay may be predicted by the corresponding KOW.

Middle Pleistocene (Saalian) lake outburst floods in the Münsterland Embayment (NW Germany): impacts and magnitudes

NASA Astrophysics Data System (ADS)

Meinsen, Janine; Winsemann, Jutta; Weitkamp, Axel; Landmeyer, Nils; Lenz, Andreas; Dölling, Manfred

2011-09-01

During the late Saalian Drenthe glaciation ice-damming of the Upper Weser Valley led to the formation of glacial Lake Weser. The lake drained catastrophically into the Münsterland Embayment as the western ice dam failed, releasing up to 110 km 3 of water with a calculated peak discharge of 2.5 × 10 5 m 3/s to 1.3 × 10 6 m 3/s. Geographic information systems (GIS) and high-resolution digital elevation models (DEM) were used to map streamlined landforms and channel systems in front of lake overspills. Geological maps, 2450 boreholes and the DEM were integrated into the 3D modeling program GOCAD to reconstruct the distribution of flood-related deposits, palaeotopographic surfaces and the internal facies architecture of streamlined hills. The drainage pathways are characterized by the occurrence of deep plunge pools, channels, streamlined hills and 4 km long and 12 m deep V-shaped megaflutes. Plunge pools are deeply incised into Mesozoic basement rocks and occur in front of three major overspill channels. The plunge pools are up to 780 m long, 400 m wide and 35 m deep. Approximately 1-10.5 km downslope of the overspill channels fan shaped arrays of streamlined hills are developed, each covering an area of 60-130 km 2, indicating rapid flow expansion. The hills commonly have quadrilateral to elongated shapes and formed under submerged to partly submerged flow conditions, when the outburst flood entered a shallow lake in the Münsterland Embayment. Hills are up to 4300 m long, 1200 m wide, 11 m high and have characteristic average aspect ratios of 1:3.3. They are separated by shallow, anabranching channels in the outer zones and up to 30 m deep channels in the central zones. Hills partly display V-shaped chevron-like bedforms that have apices facing upslope, are 1.6-2.5 km long, 3-10 m high, 0.8-1.2 m from limb to limb, with limb separation angels of 20-35°. These bedforms are interpreted as mixed erosional depositional features. It is hypothesized that the post-Saalian landscape evolution of the Münsterland Embayment has considerably been influenced by catastrophic floods of glacial Lake Weser, creating large and deep valleys, which subsequently became the new site of river systems. The outburst floods probably followed the east-west-trending Saalian Rhine-Meuse river system eventually flowing into the North Sea, the Strait of Dover and the Bay of Biscay. It is speculated that the Hondsrug ice stream may have been enhanced or even triggered by the formation and outburst of glacial lakes in the study area.

Sedimentary processes and depositional environments of the Horn River Shale in British Columbia, Canada

NASA Astrophysics Data System (ADS)

Yoon, Seok-Hoon; Koh, Chang-Seong; Joe, Young-Jin; Woo, Ju-Hwan; Lee, Hyun-Suk

2017-04-01

The Horn River Basin in the northeastern British Columbia, Canada, is one of the largest unconventional gas accumulations in North America. It consists mainly of Devonian shales (Horn River Formation) and is stratigraphically divided into three members, the Muskwa, Otterpark and Evie in descending order. This study focuses on sedimentary processes and depositional environments of the Horn River shale based on sedimentary facies analysis aided by well-log mineralogy (ECS) and total organic carbon (TOC) data. The shale formation consists dominantly of siliceous minerals (quartz, feldspar and mica) and subordinate clay mineral and carbonate materials, and TOC ranging from 1.0 to 7.6%. Based on sedimentary structures and micro texture, three sedimentary facies were classified: homogeneous mudstone (HM), indistinctly laminated mudstone (ILM), and planar laminated mudstone (PLM). Integrated interpretation of the sedimentary facies, lithology and TOC suggests that depositional environment of the Horn River shale was an anoxic quiescent basin plain and base-of-slope off carbonate platform or reef. In this deeper marine setting, organic-rich facies HM and ILM, dominant in the Muskwa (the upper part of the Horn River Formation) and Evie (the lower part of the Horn River Formation) members, may have been emplaced by pelagic to hemipelagic sedimentation on the anoxic sea floor with infrequent effects of low-density gravity flows (turbidity currents or nepheloid flows). In the other hand, facies PLM typifying the Otterpark Member (the middle part of the Horn River Formation) suggests more frequent inflow of bottom-hugging turbidity currents punctuating the hemipelagic settling of the background sedimentation process. The stratigraphic change of sedimentary facies and TOC content in the Horn River Formation is most appropriately interpreted to have been caused by the relative sea-level change, that is, lower TOC and frequent signal of turbidity current during the sea-level lowstand and vice versa. Therefore, the Horn River Formation represents an earlier upward shallowing environmental change from a deep basin (Evie) to shallower marginal slope (middle Otterpark), then turning back to the deeper marine environment (Muskwa) in association with overall regression-lowstand-transgression of the sea level. (This study is supported by "Research on Exploration Technologies and an Onsite Verification to Enhance the Fracturing Efficiency of a Shale Gas Formation" of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea.)

Geology and hydrology of the Fort Belknap Indian Reservation, Montana

USGS Publications Warehouse

Alverson, Douglas C.

1965-01-01

The Fort Belknap Indian Reservation includes an area of 970 square miles in north-central Montana. At its north edge is the Milk River valley, which is underlain by Recent alluvium of the Milk River, glacial deposits, and alluvial deposits of the preglacial Missouri River, which carved and occupied this valley before the Pleistocene Epoch. Rising gently to the south is an undulating glaciated plain broken only by three small syenite porphyry intrusions. Underlying the glacial till of the plain are Upper Cretaceous shale and sandstone of the Bearpaw and Judith River Formations. At the south end of the reservation, 40 miles from the Milk River, an intrusion of syenite porphyry in Tertiary time uplifted, tilted, and exposed the succession of sedimentary rocks overlying the Precambrian metamorphic basement. The sedimentary rocks include 1,000 feet of sandstone and shale of Cambrian age; 2,000 feet of limestone and dolomite of Ordovician, Devonian, and Mississippian age; 400 feet of shale and limestone of Jurassic age; and 3,500 feet of sandstone, siltstone, and shale of Cretaceous age. Extensive gravel terraces of Tertiary and Quaternary age bevel the upturned bedrock formations exposed around the Little Rocky Mountains. Ground water under water-table conditions is obtained at present from alluvium, glaciofluvial deposits, and the Judith River Formation. The water table ranges in depth from a few feet beneath the surface in the Milk River valley alluvium to more than 100 feet deep in the Judith River Formation. Yields to wells are generally low but adequate for domestic and stock-watering use. Quality of the water ranges from highly mineralized and unusable to excellent; many wells in the Milk River valley have been abandoned because of the alkalinity of their water. Potential sources of additional ground-water supplies are the alluvial gravel of creeks issuing from the Little Rocky Mountains and some extensive areas of terrace gravel. The uplift and tilting of the sedimentary sequence around the Little Rocky Mountains and the minor intrusions in the central plain have created artesian conditions within aquifers. Wells obtain artesian water from sandstone aquifers in the Judith River, Eagle, and Kootenai Formations. Other potential aquifers, near their outcrop areas, are the Ellis Group and the Mission Canyon Limestone. Most wells that flow at the surface have small yields, but discharges of as much as 150 gallons per minute have been noted. Quality of artesian water ranges from poor to good. Well depths range from less than 50 to more than 300 feet.

Hazardous geology zoning and influence factorsin the near-shore shallow strata and seabed surfaceof the modern Yellow River Delta, China

NASA Astrophysics Data System (ADS)

Li, P.

2016-12-01

In this study, on the basis of 3,200 km shallow stratigraphic section and sidescan sonar data of the coastal area of the Yellow River Delta, we delineated and interpreted a total of seven types of typical hazardous geologies, including the hazardous geology in the shallow strata (buried ancient channel and strata disturbance) and hazardous geology in the seabed surface strata (pit, erosive residual body, sand patch, sand wave and scour channel). We selected eight parameters representing the development scale of the hazardous geology as the zoning indexes, including the number of hazardous geology types, pit depth, height of erosive residual body, length of scour channel, area of sand patch, length of sand wave, width of the buried ancient channel and depth of strata disturbance, and implemented the grid processing of the research area to calculate the arithmetic sum of the zoning indexes of each unit grid one by one. We then adopted the clustering analysis method to divide the near-shore waters of the Yellow River Delta into five hazardous geology areas, namely the serious erosion disaster area controlled by Diaokou lobe waves, hazardous geology area of multi-disasters under the combined action of the Shenxiangou lobe river wave flow, accumulation type hazardous geology area controlled by the current estuary river, hazardous geology area of single disaster in the deep water area and potential hazardous geology area of the Chengdao Oilfield. All four of the main factors affecting the development of hazardous geology, namely the diffusion and movement of sediment flux of the Yellow River water entering the sea, seabed stability, bottom sediment type and distribution, as well as the marine hydrodynamic characteristics, show significant regional differentiation characteristics and laws. These characteristics and laws are consistent with the above-mentioned zoning results, in which the distribution, scale and genetic mechanism of hazardous geology are considered comprehensively. This indicates that the hazardous geology zoning based on the cluster analysis is a new attempt in research regarding the hazardous geology zoning of the near-shore waters of the modern Yellow River Delta and that this type of zoning has a high level of reasonability.

Monitoring and Mapping Off-Channel Water Quality in the Willamette River, Oregon

NASA Astrophysics Data System (ADS)

Buccola, N. L.; Rounds, S. A.; Smith, C.; Anderson, C.; Jones, K.; Mangano, J.; Wallick, R.

2016-12-01

The floodplain of the Willamette River in northwestern Oregon includes remnant slower-moving sloughs, side-channels, and alcoves that provide rearing habitat and potential cool-water sources for native cold-water fish species, such as the federally threatened Chinook salmon. The mapping and characterization of the hydraulics and water sources of these off-channel areas is the first step toward protecting and restoring these resources for future generations. A primary focus of this study is to determine how flow management can increase the habitat value of these off-channel areas, especially during summer low-flow periods when water temperatures in the main channel regularly exceed lethal temperatures for salmonids. The U.S. Geological Survey, in cooperation with U.S. Army Corps of Engineers and Oregon State University, has been measuring the characteristics of off-channel water quality in the Willamette River under a variety of water levels in summer 2015-16. About 30 diverse off-channel sites within the Willamette floodplain are being monitored and compared with conditions in the main channel. Hourly water temperature, conductivity, and dissolved oxygen (DO) data are being collected at a subset of these sites. Some deep off-channel pools have substantial, consistent cool-water inflows that can dominate locally, allowing them to function as cold-water refuges for salmonids at varying mainstem Willamette flows. Other sloughs have varying characteristics due to intermittent connections to the main channel, depending on river levels. A vibrant community of algae and aquatic macrophytes often coincide with thick layers of fine sediment or organic detritus near the bed, producing low DO zones (<5 mg/L) in many slower-moving off-channel areas. We propose some preliminary hydro-geomorphic categories to better explain cool inflows as sourced from regional groundwater aquifers or localized subsurface river features. A better understanding of the processes governing the presence, location, and type of cold-water refuge areas in a large gravel bed river such as the Willamette River will help inform and guide habitat management and restoration strategies.

The spatial distribution and temporal variation of desert riparian forests and their influencing factors in the downstream Heihe River basin, China

NASA Astrophysics Data System (ADS)

Ding, Jingyi; Zhao, Wenwu; Daryanto, Stefani; Wang, Lixin; Fan, Hao; Feng, Qiang; Wang, Yaping

2017-05-01

Desert riparian forests are the main restored vegetation community in Heihe River basin. They provide critical habitats and a variety of ecosystem services in this arid environment. Since desert riparian forests are also sensitive to disturbance, examining the spatial distribution and temporal variation of these forests and their influencing factors is important to determine the limiting factors of vegetation recovery after long-term restoration. In this study, field experiment and remote sensing data were used to determine the spatial distribution and temporal variation of desert riparian forests and their relationship with the environmental factors. We classified five types of vegetation communities at different distances from the river channel. Community coverage and diversity formed a bimodal pattern, peaking at the distances of 1000 and 3000 m from the river channel. In general, the temporal normalized difference vegetation index (NDVI) trend from 2000 to 2014 was positive at different distances from the river channel, except for the region closest to the river bank (i.e. within 500 m from the river channel), which had been undergoing degradation since 2011. The spatial distribution of desert riparian forests was mainly influenced by the spatial heterogeneity of soil properties (e.g. soil moisture, bulk density and soil particle composition). Meanwhile, while the temporal variation of vegetation was affected by both the spatial heterogeneity of soil properties (e.g. soil moisture and soil particle composition) and to a lesser extent, the temporal variation of water availability (e.g. annual average and variability of groundwater, soil moisture and runoff). Since surface (0-30 cm) and deep (100-200 cm) soil moisture, bulk density and the annual average of soil moisture at 100 cm obtained from the remote sensing data were regarded as major determining factors of community distribution and temporal variation, conservation measures that protect the soil structure and prevent soil moisture depletion (e.g. artificial soil cover and water conveyance channels) were suggested to better protect desert riparian forests under climate change and intensive human disturbance.

Detailed north-south cross section showing environments of deposition, organic richness, and thermal maturities of lower Tertiary rocks in the Uinta Basin, Utah

USGS Publications Warehouse

Johnson, Ronald C.

2014-01-01

The Uinta Basin of northeast Utah has produced large amounts of hydrocarbons from lower Tertiary strata since the 1960s. Recent advances in drilling technologies, in particular the development of efficient methods to drill and hydraulically fracture horizontal wells, has spurred renewed interest in producing hydrocarbons from unconventional low-permeability dolomite and shale reservoirs in the lacustrine, Eocene Green River Formation. The Eocene Green River Formation was deposited in Lake Uinta, a long-lived saline lake that occupied the Uinta Basin, the Piceance Basin to the east, and the intervening Douglas Creek arch. The focus of recent drilling activity has been the informal Uteland Butte member of the Green River Formation and to a much lesser extent the overlying R-0 oil shale zone of the Green River Formation. Initial production rates ranging from 500 to 1,500 barrels of oil equivalent per day have been reported from the Uteland Butte member from horizontal well logs that are as long as 4,000 feet (ft);. The cross section presented here extends northward from outcrop on the southern margin of the basin into the basin’s deep trough, located just south of the Uinta Mountains, and transects the area where this unconventional oil play is developing. The Monument Butte field, which is one of the fields located along this line of section, has produced hydrocarbons from conventional sandstone reservoirs in the lower part of the Green River Formation and underlying Wasatch Formation since 1981. A major fluvial-deltaic system entered Lake Uinta from the south, and this new line of section is ideal for studying the effect of the sediments delivered by this drainage on hydrocarbon reservoirs in the Green River Formation. The cross section also transects the Greater Altamont-Bluebell field in the deepest part of the basin, where hydrocarbons have been produced from fractured, highly overpressured marginal lacustrine and fluvial reservoirs in the Green River, Wasatch, and North Horn Formations since 1970. Datum for the cross section is sea level so that hydrocarbon source rocks and reservoir rocks could be integrated into the structural framework of the basin.

Pesticides in the Lower Clackamas River Basin, Oregon, 2000-01

USGS Publications Warehouse

Carpenter, Kurt D.

2004-01-01

In 2000-01, the U. S. Geological Survey sampled the Clackamas River and its major lower-basin tributaries during storm runoff conditions for 86 dissolved pesticides and selected breakdown products. Twenty-seven compounds, including 18 herbicides, 7 insecticides, and 2 pesticide breakdown products, were detected in 18 stream samples. The most commonly detected pesticides, in decreasing frequency, included atrazine, simazine, diazinon, metolachlor, and diuron, which variously occurred in 46-92% of samples collected from the tributaries. Of these, atrazine, simazine, and metolachlor, plus six other compounds, also were detected in the main-stem Clackamas River. Pesticides were detected more frequently and at higher concentrations in the four lowermost tributaries (Deep, Richardson, Rock, and Sieben Creeks). In these streams, 12 to 18 pesticides were detected per stream in samples collected during spring and fall. Pesticides always occurred with at least one other pesticide, and about half of the samples, including one sample from the Clackamas River in October 2000, contained six or more pesticides. Nine pesticides, including the insecticide diazinon and the herbicides 2,4-D, atrazine, dichlobenil, diuron, imazaquin, metolachlor, simazine, and trifluralin, were detected in five water samples of Clackamas River water. No pesticides were detected in three samples of treated Clackamas River water used for drinking-water supply. Concentrations of six compounds--carbaryl, chlorpyrifos, diazinon, dieldrin, malathion, and the breakdown product of DDT (p,p'-DDE)--exceeded established or recommended criteria for the protection of aquatic life in some of the tributaries, sometimes for multiple pesticides in one sample. Identifying the sources of pesticides detected in the Clackamas River Basin is difficult because of the diverse land use in the basin and the multiple-use nature of many of the pesticides detected. Of the 25 parent compounds detected, 22 have agricultural uses, 23 have urban uses, 16 are applied to golf courses, 11 are applied along roads and other right-of-ways, and 5 have or had forestry applications. Because only a small fraction of the thousands of pesticide products registered for use in Oregon were tested for in this study, future monitoring could benefit from knowledge of what pesticides are applied so that potential problems can be identified and managed.

Deep Crustal Structure beneath Large Igneous Provinces and the Petrologic Evolution of Flood Basalts

NASA Astrophysics Data System (ADS)

Richards, Mark; Ridley, Victoria

2010-05-01

We present a review of seismological constraints on deep crustal structures underlying large igneous provinces (LIPs), largely from wide-angle seismic refraction surveys. The main purpose of this review is to ascertain whether this seismic evidence is consistent with, or contrary to, petrological models for the genesis of flood basalt lavas. Where high-quality data are available beneath continental flood basalt (CFB) provinces (Emeishan, Columbia River, Deccan, Siberia), high-velocity structures (Vp ~6.9-7.5 km/sec) are typically found immediately overlying the Moho in layers of order ~5-15 km thick. Oceanic plateau (OP) LIPs exhibit similar layers, with a conspicuous layer of very high crustal velocity (Vp~7.7 km/sec) beneath the enormous Ontong-Java plateau. These structures are similar to inferred ultramafic underplating structures seen beneath active hotspots such as Hawaii, the Marqueses, and La Reunion. Petrogenetic models for flood basalt volcanism based on hot plume melting beneath mature lithosphere suggest that these deep seismic structures may consist in large part of cumulate bodies of olivine and clinopyroxene which result from ponding and deep-crustal fractionation of ultramafic primary melts. Such fractionation is necessary to produce basalts with typical MgO contents of ~6-8%, as observed for the vast bulk of observed flood basalts, from primary melts with MgO contents of order ~15-18% (or greater) such as result from hot, deep melting beneath the lithosphere. The volumes of cumulate bodies and ultramafic intrusions in the lowermost crust, often described in the literature as "underplating," are comparable to those of the overlying basaltic formations, also consistent with petrological models. Further definition of the deep seismic structure beneath such prominent LIPs as the Ontong-Java Plateau could place better constraints on flood basalt petrogenesis by determining the relative volumes of ultramafic bodies and basaltic lavas, thereby better constraining the overall process of LIP emplacement.

Deep crustal structure beneath large igneous provinces and the petrologic evolution of flood basalts

NASA Astrophysics Data System (ADS)

Ridley, Victoria A.; Richards, Mark A.

2010-09-01

We present a review of seismological constraints on deep crustal structures underlying large igneous provinces (LIPs), largely from wide-angle seismic refraction surveys. The main purpose of this review is to ascertain whether this seismic evidence is consistent with, or contrary to, petrological models for the genesis of flood basalt lavas. Where high-quality data are available beneath continental flood basalt (CFB) provinces (Emeishan, Columbia River, Deccan, Siberia), high-velocity structures (Vp ˜ 6.9-7.5 km/sec) are typically found immediately overlying the Moho in layers of order ˜5-15 km thick. Oceanic plateau (OP) LIPs exhibit similar layers, with a conspicuous layer of very high crustal velocity (Vp ˜ 7.7 km/sec) beneath the enormous Ontong-Java plateau. These structures are similar to inferred ultramafic underplating structures seen beneath active hot spots such as Hawaii, the Marquesas, and La Reunion. Petrogenetic models for flood basalt volcanism based on hot plume melting beneath mature lithosphere suggest that these deep seismic structures may consist in large part of cumulate bodies of olivine and clinopyroxene which result from ponding and deep-crustal fractionation of ultramafic primary melts. Such fractionation is necessary to produce basalts with typical MgO contents of ˜6-8%, as observed for the vast bulk of observed flood basalts, from primary melts with MgO contents of order ˜15-18% (or greater) such as result from hot, deep melting beneath the lithosphere. The volumes of cumulate bodies and ultramafic intrusions in the lowermost crust, often described in the literature as "underplating," are comparable to those of the overlying basaltic formations, also consistent with petrological models. Further definition of the deep seismic structure beneath such prominent LIPs as the Ontong-Java Plateau could place better constraints on flood basalt petrogenesis by determining the relative volumes of ultramafic bodies and basaltic lavas, thereby better constraining the overall process of LIP emplacement.

Deep Crustal Structure beneath Large Igneous Provinces and the Petrologic Evolution of Flood Basalts

NASA Astrophysics Data System (ADS)

Richards, M. A.; Ridley, V. A.

2010-12-01

We present a review of seismological constraints on deep crustal structures underlying large igneous provinces (LIPs), largely from wide-angle seismic refraction surveys. The main purpose of this review is to ascertain whether this seismic evidence is consistent with, or contrary to, petrological models for the genesis of flood basalt lavas. Where high-quality data are available beneath continental flood basalt (CFB) provinces (Emeishan, Columbia River, Deccan, Siberia), high-velocity structures (Vp ~6.9-7.5 km/sec) are typically found immediately overlying the Moho in layers of order ~5-15 km thick. Oceanic plateau (OP) LIPs exhibit similar layers, with a conspicuous layer of very high crustal velocity (Vp~7.7 km/sec) beneath the enormous Ontong-Java plateau. These structures are similar to inferred ultramafic underplating structures seen beneath active hotspots such as Hawaii, the Marquesas, and La Reunion. Petrogenetic models for flood basalt volcanism based on hot plume melting beneath mature lithosphere suggest that these deep seismic structures may consist in large part of cumulate bodies of olivine and clinopyroxene which result from ponding and deep-crustal fractionation of ultramafic primary melts. Such fractionation is necessary to produce basalts with typical MgO contents of ~6-8%, as observed for the vast bulk of observed flood basalts, from primary melts with MgO contents of order ~15-18% (or greater) such as result from hot, deep melting beneath the lithosphere. The volumes of cumulate bodies and ultramafic intrusions in the lowermost crust, often described in the literature as “underplating,” are comparable to those of the overlying basaltic formations, also consistent with petrological models. Further definition of the deep seismic structure beneath such prominent LIPs as the Ontong-Java Plateau could place better constraints on flood basalt petrogenesis by determining the relative volumes of ultramafic bodies and basaltic lavas, thereby better constraining the overall process of LIP emplacement.

Quaternary climate modulation of Pb isotopes in the deep Indian Ocean linked to the Himalayan chemical weathering

NASA Astrophysics Data System (ADS)

Wilson, David J.; Galy, Albert; Piotrowski, Alexander M.; Banakar, Virupaxa K.

2015-08-01

We use reductive sediment leaching to extract lead (Pb) from the authigenic fraction of marine sediments and reconstruct the Pb isotope evolution of the deep central Indian Ocean over the past 250 thousand years at ∼3 kyr resolution. Temporal variations define a binary mixing line that is consistent with data from ferromanganese nodules and which records mixing between two well-defined endmembers through time. The unradiogenic endmember appears to represent a widely-distributed Pb source, from mid-ocean ridges or possibly volcanic aerosols, while the radiogenic endmember coincides with the composition of Ganges-Brahmaputra river sediments that are indicative of the Himalayan weathering inputs. Glacial-interglacial Pb isotope variations are striking and can be explained by an enhancement of Himalayan contributions by two to three times during interglacial periods, indicating that climate modulates the supply of dissolved elements to the ocean. While these changes could accurately record variations in the continental chemical weathering flux in response to warmer and wetter conditions during interglacials, the relative proportions of Pb derived from the Ganges and Brahmaputra appear to have been constant through time. This observation may point towards particulate-dissolved interactions in the estuary or pro-delta as a buffer of short timescale variability in the composition (and potentially flux) of the fluvial inputs. In addition, the changes are recorded at 3800 m water depth, and with the lack of deep water formation in the Bay of Bengal, a mechanism to transfer such a signature into the deep ocean could either be reversible scavenging of dissolved Pb inputs and/or boundary exchange on the deep sea fan. Unless the mechanism transferring the Pb isotope signature into the deep ocean was itself highly sensitive to global climate cycles, and with the absence of a precessional signal in our Pb isotope data, we suggest that the Indian climate and its influence on basin-scale chemical weathering were strongly modulated by glacial versus interglacial boundary conditions.

Effects of Enhanced Thaw Depth on the Composition of Arctic Soil Organic Matter Leachate

NASA Astrophysics Data System (ADS)

Hutchings, J.; Zhang, X.; Bianchi, T. S.; Schuur, E.; Arellano, A. R.; Liu, Y.

2016-12-01

Pan-Arctic permafrost is increasingly susceptible to thaw due to the disproportionally high rate of temperature change in high latitudes. These soils contain a globally significant quantity of organic carbon that, when thawed, interacts with the modern carbon cycle. Current research has focused on atmospheric carbon fluxes and transport by rivers and streams to continental shelves, but has overlooked the lateral flux of carbon within watershed soils, which is the primary link between terrestrial and riverine ecosystems. Understanding the effects of water movement through permafrost soils on dissolved organic carbon is critical to better modelling of lateral carbon fluxes and interpreting the resulting observed riverine carbon fluxes with applications to investigations of the past, present, and future of the pan-Arctic. We conducted a laboratory leaching experiment using active layer soils from the Eight Mile Lake region of interior Alaska. Cores were sampled into surface and deep sections. Surface sections were subjected to a three-stage leaching process using artificial rain, with cores stored frozen overnight between stages (which crudely simulated freeze-thaw mechanisms). Surface leachates were sampled for analysis and the remainder percolated through deep soils using the same three-staged approach. Measurements of surface and deep leachates were selected to characterize transport-related changes to dissolved organic matter and included dissolved organic carbon, fluorescent dissolved organic matter via excitation emission matrices, and molecular composition via Fourier transform ion cyclotron resonance mass spectrometry. Primary findings from the experiment include a net retention of 2.4 to 27% of dissolved organic carbon from surface leachates in deep soils, a net release of fluorescent dissolved organic matter from deep soils that was 43 to 106% greater than surface leachates, increased hydrophobicity during stage three of leaching, and the preferential leaching of lignin- and tannin-like formulas from deep soils, consistent with fluorescence measurements.

Ground-water flow and quality beneath sewage-sludge lagoons, and a comparison with the ground-water quality beneath a sludge-amended landfill, Marion County, Indiana

USGS Publications Warehouse

Bobay, K.E.

1988-01-01

The groundwater beneath eight sewage sludge lagoons, was studied to characterize the flow regime and to determine whether leachate had infiltrated into the glacio-fluvial sediments. Groundwater quality beneath the lagoons was compared with the groundwater quality beneath a landfill where sludge had been applied. The lagoons and landfills overlie outwash sand and gravel deposits separated by discontinuous clay layers. Shallow groundwater flows away from the lagoons and discharges into the White River. Deep groundwater discharges to the White River and flows southwest beneath Eagle Creek. After an accumulation of at least 2 inches of precipitation during 1 week, groundwater flow is temporarily reversed in the shallow aquifer, and all deep flow is along a relatively steep hydraulic gradient to the southwest. The groundwater is predominantly a calcium bicarbonate type, although ammonium accounts for more than 30% of the total cations in water from three wells. Concentrations of sodium, chloride, sulfate, iron, arsenic, boron, chemical oxygen demand, total dissolved solids, and methylene-blue-active substances indicate the presence of leachate in the groundwater. Concentrations of cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc were less than detection limits. The concentrations of 16 of 19 constituents or properties of groundwater beneath the lagoons are statistically different than groundwater beneath the landfill at the 0.05 level of significance. Only pH and concentrations of dissolved oxygen and bromide are higher in groundwater beneath the landfill than beneath the lagoons. 

Storm-induced transfer of particulate trace metals to the deep-sea in the Gulf of Lion (NW Mediterranean Sea).

PubMed

Dumas, C; Aubert, D; Durrieu de Madron, X; Ludwig, W; Heussner, S; Delsaut, N; Menniti, C; Sotin, C; Buscail, R

2014-10-01

In order to calculate budgets of particulate matter and sediment-bound contaminants leaving the continental shelf of the Gulf of Lion (GoL), settling particles were collected in March 2011 during a major storm, using sediment traps. The collecting devices were deployed in the Cap de Creus submarine canyon, which represents the main export route. Particulate matter samples were analyzed to obtain mass fluxes and contents in organic carbon, Al, Cr, Co, Ni, Cu, Zn, Cd, Pb and La, Nd and Sm. The natural or anthropogenic origin of trace metals was assessed using enrichment factors (EFs). Results are that Zn, Cu and Pb appeared to be of anthropogenic origin, whereas Ni, Co and Cr appeared to be strictly natural. The anthropogenic contribution of all elements (except Cd) was refined by acid-leaching (HCl 1 N) techniques, confirming that Zn, Cu and Pb are the elements that are the most enriched. However, although those elements are highly labile (59-77%), they do not reflect severe enrichment (EFs <4). Most particles originate from the Rhone River. This has been confirmed by two different tracing procedures using rare earth elements ratios and concentrations of acid-leaching residual trace metals. Our results hence indicate that even in this western extremity of the GoL, storm events mainly export Rhone-derived particles via the Cap de Creus submarine canyons to the deep-sea environments. This export of material is significant as it represents about a third of the annual PTM input from the Rhone River.

[Transfer characteristic and source identification of soil heavy metals from water-level-fluctuating zone along Xiangxi River, three-Gorges Reservoir area].

PubMed

Xu, Tao; Wang, Fei; Guo, Qiang; Nie, Xiao-Qian; Huang, Ying-Ping; Chen, Jun

2014-04-01

Transfer characteristics of heavy metals and their evaluation of potential risk were studied based on determining concentration of heavy metal in soils from water-level-fluctuating zone (altitude:145-175 m) and bank (altitude: 175-185 m) along Xiangxi River, Three Gorges Reservoir area. Factor analysis-multiple linear regression (FA-MLR) was employed for heavy metal source identification and source apportionment. Results demonstrate that, during exposing season, the concentration of soil heavy metals in water-level-fluctuation zone and bank showed the variation, and the concentration of soil heavy metals reduced in shallow soil, but increased in deep soil at water-level-fluctuation zone. However, the concentration of soil heavy metals reduced in both shallow and deep soil at bank during the same period. According to the geoaccumulation index,the pollution extent of heavy metals followed the order: Cd > Pb > Cu > Cr, Cd is the primary pollutant. FA and FA-MLR reveal that in soils from water-level-fluctuation zone, 75.60% of Pb originates from traffic, 62.03% of Cd is from agriculture, 64.71% of Cu and 75.36% of Cr are from natural rock. In soils from bank, 82.26% of Pb originates from traffic, 68.63% of Cd is from agriculture, 65.72% of Cu and 69.33% of Cr are from natural rock. In conclusion, FA-MLR can successfully identify source of heavy metal and compute source apportionment of heavy metals, meanwhile the transfer characteristic is revealed. All these information can be a reference for heavy metal pollution control.

Sources and sinks of nitrogen and phosphorus to a deep, oligotrophic lake, Lake Crescent, Olympic National Park, Washington

USGS Publications Warehouse

Moran, P.W.; Cox, S.E.; Embrey, S.S.; Huffman, R.L.; Olsen, T.D.; Fradkin, S.C.

2012-01-01

Lake Crescent, in Olympic National Park in the northwest corner of Washington State is a deep-water lake renowned for its pristine water quality and oligotrophic nature. To examine the major sources and sinks of nutrients (as total nitrogen, total phosphorus, and dissolved nitrate), a study was conducted in the Lake Crescent watershed. The study involved measuring five major inflow streams, the Lyre River as the major outflow, recording weather and climatic data, coring lake bed sediment, and analyzing nutrient chemistry in several relevant media over 14 months. Water samples for total nitrogen, total phosphorous, and dissolved nitrate from the five inflow streams, the outlet Lyre River, and two stations in the lake were collected monthly from May 2006 through May 2007. Periodic samples of shallow water from temporary sampling wells were collected at numerous locations around the lake. Concentrations of nutrients detected in Lake Crescent and tributaries were then applied to the water budget estimates to arrive at monthly and annual loads from various environmental components within the watershed. Other sources, such as leaf litter, pollen, or automobile exhaust were estimated from annual values obtained from various literature sources. This information then was used to construct a nutrient budget for total nitrogen and total phosphorus. The nitrogen budget generally highlights vehicle traffic-diesel trucks in particular-along U.S. Highway 101 as a potential major anthropogenic source of nitrogen compounds in the lake. In contrast, contribution of nitrogen compounds from onsite septic systems appears to be relatively minor related to the other sources identified.

Lithofacies control of lignite distribution and ground-water quality, Wilcox group (Eocene), east-central Texas

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

Ayers, W.B. Jr.; Lewis, A.H.

1984-04-01

Deep lignite resources (200-2000 ft; 61-610 m) were evaluated regionally using 1470 geophysical well logs to interpret lithofacies, lignite occurrence, and resistivity (water quality). The regional distribution of lithofacies indicates that in the region, the Wilcox Group is a fluvial-deltaic system. The primary fluvial system entered the Wilcox coastal plain west of Waco, Texas, trended southeast, and supplied a 75-mi (120-km) wide fluvial-deltaic system comparable in size to the Mississippi system. Lignites are most abundant in the Calvert Bluff Formation (upper Wilcox). Lower Calvert Bluff lignites are thickest and most extensive southwest of the Navasota River, whereas those of themore » upper Calvert Bluff are thickest northeast of the Brazos River. In the shallow subsurface, Calvert Bluff lignites are found in dip-elongate low-sand areas (flood plains) between channel-sand belts. Basinward, laterally continuous lignites coincide with high net sand areas comprise of distributary channel sands indicative of a delta-plain setting. The wilcox Group is a major aquifer. Maps of resistivity values show that Wilcox channel sands are conduits for ground-water flow. High values of formation resistivity (low total dissolved solids) exist in recharge areas at outcrop and around salt domes. Elongate trends of high resistivity values extend tens of miles basinward and coincide with axes of major sands. Resistivity values decrease basinward and the 20 ohm-m contour delineates the downdip limit of fresh water. Lithofacies and lignite occurrence maps are guides to exploration for deep lignite. Resistivity maps can be used to explore for ground-water resources.« less

Remote sensing estimation of colored dissolved organic matter (CDOM) in optically shallow waters

NASA Astrophysics Data System (ADS)

Li, Jiwei; Yu, Qian; Tian, Yong Q.; Becker, Brian L.

2017-06-01

It is not well understood how bottom reflectance of optically shallow waters affects the algorithm performance of colored dissolved organic matters (CDOM) retrieval. This study proposes a new algorithm that considers bottom reflectance in estimating CDOM absorption from optically shallow inland or coastal waters. The field sampling was conducted during four research cruises within the Saginaw River, Kawkawlin River and Saginaw Bay of Lake Huron. A stratified field sampling campaign collected water samples, determined the depth at each sampling location and measured optical properties. The sampled CDOM absorption at 440 nm broadly ranged from 0.12 to 8.46 m-1. Field sample analysis revealed that bottom reflectance does significantly change water apparent optical properties. We developed a CDOM retrieval algorithm (Shallow water Bio-Optical Properties algorithm, SBOP) that effectively reduces uncertainty by considering bottom reflectance in shallow waters. By incorporating the bottom contribution in upwelling radiances, the SBOP algorithm was able to explain 74% of the variance of CDOM values (RMSE = 0.22 and R2 = 0.74). The bottom effect index (BEI) was introduced to efficiently separate optically shallow and optically deep waters. Based on the BEI, an adaptive approach was proposed that references the amount of bottom effect in order to identify the most suitable algorithm (optically shallow water algorithm [SBOP] or optically deep water algorithm [QAA-CDOM]) to improve CDOM estimation (RMSE = 0.22 and R2 = 0.81). Our results potentially help to advance the capability of remote sensing in monitoring carbon pools at the land-water interface.

3D stratigraphic modeling of the Congo turbidite system since 210 ka: an investigation of factors controlling sedimentation

NASA Astrophysics Data System (ADS)

Laurent, Dimitri; Picot, Marie; Marsset, Tania; Droz, Laurence; Rabineau, Marina; Granjeon, Didier; Molliex, Stéphane

2017-04-01

The geometry and internal functioning of turbidite systems are relatively well-constrained today. However, the respective role of autogenic (topographic compensation, dynamics of turbidity currents…) and allogenic factors (tectonics, sea-level, climate) governing their architectural evolution is still under debate. The geometry of the Quaternary Congo Fan is characterized by successive sedimentary prograding/retrograding cycles bounded by upfan avulsions, reflecting a periodic control of sedimentation (Picot et al., 2016). Multi-proxy studies revealed a strong interplay between autogenic control and climate forcing as evidenced by changes in fluvial sediment supplies consistent with arid and humid periods in the Congo River Basin. In the light of these results, the aim of this study is to investigate the relative impact of internal and external forcing factors controlling, both in time and space, the formation and evolution of depocenters of the Congo Deep-Sea Fan since 210 ka. This work represents the first attempt to model in 3D the stratigraphic architecture of the Congo turbidite system using DionisosFlow (IFP-EN), a diffusion process-based software. It allows the simulation of sediment transport and the 3D geometry reproduction of sedimentary units based on physical processes such as sea level changes, tectonics, sediment supply and transport. According to the modeling results, the role of topographic compensation in the deep-sea fan geometry is secondary compared to climate changes in the drainage basin. It appears that a periodic variation of sediment discharge and water flow is necessary to simulate the timing and volume of prograding/retrograding sedimentary cycles and more particularly the upfan avulsion events. The best-fit simulations show that the overriding factor for such changes corresponds to the expansion of the vegetation cover in the catchment basin associated to the Milankovitch cycle of precession which controlled the West African Monsoon intensity. These external forcing factors are responsible for the evolution of the capacity of turbidity currents by directly acting on the river runoff magnitude and the sediment budget according to the balance between mechanical and chemical erosion. If the sediment supply is the key parameter for the large scale sedimentary cycles, a steep increase of the sand/mud ratio leads to the development of sub-cycles characterized by middle fan avulsions. We identified these events as related to abrupt destabilizations of river mouth bars linked to periodic Congo River floods. Finally, the local slope gradient only plays a role in the maximal length of the turbidity currents and deposition in the most distal part of the basin. To conclude, the stratigraphic modeling allows us to propose an evolutionary "source to sink" model of the Quaternary Congo Fan, emphasizing the interconnection through time between drainage basin responses to climate change and sedimentary transfers in the deep-water environment. Picot, M. et al., 2016. Controls on turbidite sedimentation: Insights from a quantitative approach of submarine channel and lobe architecture (Late Quaternary Congo Fan). Marine and Petroleum Geology, 72, 423-446. Keywords: Congo, sedimentary basin, Quaternary, turbidite system, sedimentary cycles, geophysical data, stratigraphic modeling, DionisosFlow

Differential mobilization of terrestrial carbon pools in Eurasian Arctic river basins.

PubMed

Feng, Xiaojuan; Vonk, Jorien E; van Dongen, Bart E; Gustafsson, Örjan; Semiletov, Igor P; Dudarev, Oleg V; Wang, Zhiheng; Montluçon, Daniel B; Wacker, Lukas; Eglinton, Timothy I

2013-08-27

Mobilization of Arctic permafrost carbon is expected to increase with warming-induced thawing. However, this effect is challenging to assess due to the diverse processes controlling the release of various organic carbon (OC) pools from heterogeneous Arctic landscapes. Here, by radiocarbon dating various terrestrial OC components in fluvially and coastally integrated estuarine sediments, we present a unique framework for deconvoluting the contrasting mobilization mechanisms of surface vs. deep (permafrost) carbon pools across the climosequence of the Eurasian Arctic. Vascular plant-derived lignin phenol (14)C contents reveal significant inputs of young carbon from surface sources whose delivery is dominantly controlled by river runoff. In contrast, plant wax lipids predominantly trace ancient (permafrost) OC that is preferentially mobilized from discontinuous permafrost regions, where hydrological conduits penetrate deeper into soils and thermokarst erosion occurs more frequently. Because river runoff has significantly increased across the Eurasian Arctic in recent decades, we estimate from an isotopic mixing model that, in tandem with an increased transfer of young surface carbon, the proportion of mobilized terrestrial OC accounted for by ancient carbon has increased by 3-6% between 1985 and 2004. These findings suggest that although partly masked by surface carbon export, climate change-induced mobilization of old permafrost carbon is well underway in the Arctic.

Stratigraphic record of the Yellowstone hotspot track, Neogene Sixmile Creek Formation grabens, southwest Montana

NASA Astrophysics Data System (ADS)

Sears, James W.; Hendrix, Marc S.; Thomas, Robert C.; Fritz, William J.

2009-11-01

The Sixmile Creek Formation fills deep grabens in southwest Montana and preserves a stratigraphic record of the evolution of the Yellowstone hotspot track from ~ 17 Ma to ~ 2 Ma. The Ruby, Beaverhead, Big Hole, Deer Lodge, Medicine Lodge-Grasshopper, Three Forks, Canyon Ferry, Jefferson, Melrose, Wise River, and Paradise grabens were active during outbreak of the hotspot. They appear to be parts of a radial system of extensional structures that may have formed on a broad dome that was centered on the hotspot outbreak area in southwest Idaho and southeast Oregon. Early in the evolution of the grabens, massive debris flows surged down Paleogene paleovalleys from uplifted and tilted horst blocks and accumulated in the grabens. The grabens captured runoff from the hotspot dome with thick deposits of river gravel that appear to have been derived, in part, from east-central Idaho. As the hotspot track propagated along the eastern Snake River Plain, silicic ash fell into the graben drainage basins and was reworked into thick fluvial beds along graben axes. The grabens were cross-cut by northwest-trending late Neogene grabens that propagated on the flanks of silicic volcanic centers along the hotspot track. The late Neogene grabens diverted the Middle Miocene drainage patterns in southwest Montana.

Evaluating the use of side-scan sonar for detecting freshwater mussel beds in turbid river environments

USGS Publications Warehouse

Powers, Jarrod; Brewer, Shannon K.; Long, James M.; Campbell, Thomas

2015-01-01

Side-scan sonar is a valuable tool for mapping habitat features in many aquatic systems suggesting it may also be useful for locating sedentary biota. The objective of this study was to determine if side-scan sonar could be used to identify freshwater mussel (unionid) beds and the required environmental conditions. We used side-scan sonar to develop a series of mussel-bed reference images by placing mussel shells within homogenous areas of fine and coarse substrates. We then used side-scan sonar to map a 32-km river reach during spring and summer. Using our mussel-bed reference images, several river locations were identified where mussel beds appeared to exist in the scanned images and we chose a subset of sites (n = 17) for field validation. The validation confirmed that ~60% of the sites had mussel beds and ~80% had some mussels or shells present. Water depth was significantly related to our ability to predict mussel-bed locations: predictive ability was greatest at depths of 1–2 m, but decreased in water >2-m deep. We determined side-scan sonar is an effective tool for preliminary assessments of mussel presence during times when they are located at or above the substrate surface and in relatively fine substrates excluding fine silt.

Landslide inventory for the Little North Santiam River Basin, Oregon

USGS Publications Warehouse

Sobieszczyk, Steven

2010-01-01

This geodatabase is an inventory of existing landslides in the Little North Santiam River Basin, Oregon (2009). Each landslide feature shown has been classified according to a number of specific characteristics identified at the time recorded in the GIS database. The classification scheme was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009). Several significant landslide characteristics recorded in the database are portrayed with symbology on this map. The specific characteristics shown for each landslide are the activity of landsliding, landslide features, deep or shallow failure, type of landslide movement, and confidence of landslide interpretation. These landslide characteristics are determined primarily on the basis of geomorphic features, or landforms, observed for each landslide. This work was completed as part of the Master's thesis "Turbidity Monitoring and LiDAR Imagery Indicate Landslides are Primary Source of Suspended-Sediment Load in the Little North Santiam River Basin, Oregon, Winter 2009-2010" by Steven Sobieszczyk, Portland State University and U.S. Geological Survey. Data layers in this geodatabase include: landslide deposit boundaries (Deposits); field-verfied location imagery (Photos); head scarp or scarp flanks (Scarp_Flanks); and secondary scarp features (Scarps).The geodatabase template was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009).

Landslide deposit boundaries for the Little North Santiam River Basin, Oregon

USGS Publications Warehouse

Sobieszczyk, Steven

2010-01-01

This layer is an inventory of existing landslides deposits in the Little North Santiam River Basin, Oregon (2009). Each landslide deposit shown on this map has been classified according to a number of specific characteristics identified at the time recorded in the GIS database. The classification scheme was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009). Several significant landslide characteristics recorded in the database are portrayed with symbology on this map. The specific characteristics shown for each landslide are the activity of landsliding, landslide features, deep or shallow failure, type of landslide movement, and confidence of landslide interpretation. These landslide characteristics are determined primarily on the basis of geomorphic features, or landforms, observed for each landslide. This work was completed as part of the Master's thesis "Turbidity Monitoring and LiDAR Imagery Indicate Landslides are Primary Source of Suspended-Sediment Load in the Little North Santiam River Basin, Oregon, Winter 2009-2010" by Steven Sobieszczyk, Portland State University and U.S. Geological Survey.Data layers in this geodatabase include: landslide deposit boundaries (Deposits); field-verfied location imagery (Photos); head scarp or scarp flanks (Scarp_Flanks); and secondary scarp features (Scarps).The geodatabase template was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009).

Land clearance and river salinisation in the western Murray Basin, Australia

NASA Astrophysics Data System (ADS)

Allison, G. B.; Cook, P. G.; Barnett, S. R.; Walker, G. R.; Jolly, I. D.; Hughes, M. W.

1990-11-01

The clearing of native vegetation in a semi-arid region of southern Australia has led to increases in groundwater recharge of about two orders of magnitude. Although most of the clearing took place early this century, the generally deep water table along with the low rates of recharge means that there is a considerable delay in the response of the aquifer to the increased recharge. The rates of pre- and post-clearing recharge, and the time delay in aquifer response have been estimated using unsaturated zone chloride and matric suction profiles. Predictions of the time lag in aquifer response have been verified using bore hydrographs. The results of these analyses suggest that where the soils are light textured, and the water table is less than 40 m below the soil surface, it is now rising. Where the soils are heavier textured, it is estimated that the water table is rising only where it is less than 10 m below the soil surface. The effect of the increased recharge rates on the salinity of the River Murray, a major water resource, have been predicted using a groundwater model of the region. The predictions suggest that the salinity of the river will increase at about 1 μS cm -1 year -1 over the next 50 years and beyond.

The fish diversity in the upper reaches of the Salween River, Nujiang River, revealed by DNA barcoding.

PubMed

Chen, Weitao; Ma, Xiuhui; Shen, Yanjun; Mao, Yuntao; He, Shunping

2015-11-30

Nujiang River (NR), an essential component of the biodiversity hotspot of the Mountains of Southwest China, possesses a characteristic fish fauna and contains endemic species. Although previous studies on fish diversity in the NR have primarily consisted of listings of the fish species observed during field collections, in our study, we DNA-barcoded 1139 specimens belonging to 46 morphologically distinct fish species distributed throughout the NR basin by employing multiple analytical approaches. According to our analyses, DNA barcoding is an efficient method for the identification of fish by the presence of barcode gaps. However, three invasive species are characterized by deep conspecific divergences, generating multiple lineages and Operational Taxonomic Units (OTUs), implying the possibility of cryptic species. At the other end of the spectrum, ten species (from three genera) that are characterized by an overlap between their intra- and interspecific genetic distances form a single genetic cluster and share haplotypes. The neighbor-joining phenogram, Barcode Index Numbers (BINs) and Automatic Barcode Gap Discovery (ABGD) identified 43 putative species, while the General Mixed Yule-coalescence (GMYC) identified five more OTUs. Thus, our study established a reliable DNA barcode reference library for the fish in the NR and sheds new light on the local fish diversity.

Regional and Household Adaptation Strategies to Climate Extremes: the Case Study of the Beava River Basin, the Czech Republic

NASA Astrophysics Data System (ADS)

Duží, Barbora; Stojanov, Robert; Vikhrov, Dmytro

2013-04-01

We investigate regional and household adaptation strategies in the region affected by climate extremes, focusing on floods occurrence during past 15 years period. The main research question is: What is the overall state of adaptation measurements to climate extremes on the Bečva river basin? Target area is located along upper and middle part of the Bečva river basin in the east of the Czech Republic. The main theoretical concepts draw from differentiations between coping/adaptation strategies to climate extremes and theory of focusing event as a starter of changes in attention and agenda of problem solution. We apply mixed empirical research and case study approach. First we use qualitative research to serve as an initial entrance to the issue, to find out the perception of adaptation progress and preparedness to climate extremes on regional level. We conducted deep interviews (N=20) with relevant stakeholders. We proceed with quantitative research through the conducting face-to face questionnaires with household residents (N=305) in no, low and no risk area in relation to flood occurrence. We designed set of questions to find out relation among experiences with flood, the level of damages and applied emergency and adaptation measurements.

High-altitude diving in river otters: coping with combined hypoxic stresses.

PubMed

Crait, Jamie R; Prange, Henry D; Marshall, Noah A; Harlow, Henry J; Cotton, Clark J; Ben-David, Merav

2012-01-15

River otters (Lontra canadensis) are highly active, semi-aquatic mammals indigenous to a range of elevations and represent an appropriate model for assessing the physiological responses to diving at altitude. In this study, we performed blood gas analyses and compared blood chemistry of river otters from a high-elevation (2357 m) population at Yellowstone Lake with a sea-level population along the Pacific coast. Comparisons of oxygen dissociation curves (ODC) revealed no significant difference in hemoglobin-oxygen (Hb-O(2)) binding affinity between the two populations - potentially because of demands for tissue oxygenation. Instead, high-elevation otters had greater Hb concentrations (18.7 g dl(-1)) than sea-level otters (15.6 g dl(-1)). Yellowstone otters displayed higher levels of the vasodilator nitric oxide (NO), and half the concentration of the serum protein albumin, possibly to compensate for increased blood viscosity. Despite compensation in several hematological and serological parameters, theoretical aerobic dive limits (ADL) were similar between high-elevation and sea-level otters because of the lower availability of O(2) at altitude. Our results suggest that recent disruptions to the Yellowstone Lake food web could be detrimental to otters because at this high elevation, constraints on diving may limit their ability to switch to prey in a deep-water environment.

The fish diversity in the upper reaches of the Salween River, Nujiang River, revealed by DNA barcoding

PubMed Central

Chen, Weitao; Ma, Xiuhui; Shen, Yanjun; Mao, Yuntao; He, Shunping

2015-01-01

Nujiang River (NR), an essential component of the biodiversity hotspot of the Mountains of Southwest China, possesses a characteristic fish fauna and contains endemic species. Although previous studies on fish diversity in the NR have primarily consisted of listings of the fish species observed during field collections, in our study, we DNA-barcoded 1139 specimens belonging to 46 morphologically distinct fish species distributed throughout the NR basin by employing multiple analytical approaches. According to our analyses, DNA barcoding is an efficient method for the identification of fish by the presence of barcode gaps. However, three invasive species are characterized by deep conspecific divergences, generating multiple lineages and Operational Taxonomic Units (OTUs), implying the possibility of cryptic species. At the other end of the spectrum, ten species (from three genera) that are characterized by an overlap between their intra- and interspecific genetic distances form a single genetic cluster and share haplotypes. The neighbor-joining phenogram, Barcode Index Numbers (BINs) and Automatic Barcode Gap Discovery (ABGD) identified 43 putative species, while the General Mixed Yule-coalescence (GMYC) identified five more OTUs. Thus, our study established a reliable DNA barcode reference library for the fish in the NR and sheds new light on the local fish diversity. PMID:26616046

Groundwater flood of a river terrace in southwest Wisconsin, USA

NASA Astrophysics Data System (ADS)

Gotkowitz, Madeline B.; Attig, John W.; McDermott, Thomas

2014-09-01

Intense rainstorms in 2008 resulted in wide-spread flooding across the Midwestern United States. In Wisconsin, floodwater inundated a 17.7-km2 area on an outwash terrace, 7.5 m above the mapped floodplain of the Wisconsin River. Surface-water runoff initiated the flooding, but results of field investigation and modeling indicate that rapid water-table rise and groundwater inundation caused the long-lasting flood far from the riparian floodplain. Local geologic and geomorphic features of the landscape lead to spatial variability in runoff and recharge to the unconfined sand and gravel aquifer, and regional hydrogeologic conditions increased groundwater discharge from the deep bedrock aquifer to the river valley. Although reports of extreme cases of groundwater flooding are uncommon, this occurrence had significant economic and social costs. Local, state and federal officials required hydrologic analysis to support emergency management and long-term flood mitigation strategies. Rapid, sustained water-table rise and the resultant flooding of this high-permeability aquifer illustrate a significant aspect of groundwater system response to an extreme precipitation event. Comprehensive land-use planning should encompass the potential for water-table rise and groundwater flooding in a variety of hydrogeologic settings, as future changes in climate may impact recharge and the water-table elevation.

Geology and geophysics of the southern Raft River Valley geothermal area, Idaho, USA

USGS Publications Warehouse

Williams, Paul L.; Mabey, Don R.; Zohdy, Adel A.R.; Ackermann, Hans D.; Hoover, Donald B.; Pierce, Kenneth L.; Oriel, Steven S.

1976-01-01

The Raft River valley, near the boundary of the Snake River plain with the Basin and Range province, is a north-trending late Cenozoic downwarp bounded by faults on the west, south, and east. Pleistocene alluvium and Miocene-Pliocene tuffaceous sediments, conglomerate, and felsic volcanic rocks aggregate 2 km in thickness. Large gravity, magnetic, and total field resistivity highs probably indicate a buried igneous mass that is too old to serve as a heat source. Differing seismic velocities relate to known or inferred structures and to a suspected shallow zone of warm water. Resistivity anomalies reflect differences of both composition and degree of alteration of Cenozoic rocks. Resistivity soundings show a 2 to 5 ohm·m unit with a thickness of 1 km beneath a large part of the valley, and the unit may indicate partly hot water and partly clayey sediments. Observed self-potential anomalies are believed to indicate zones where warm water rises toward the surface. Boiling wells at Bridge, Idaho are near the intersection of north-northeast normal faults which have moved as recently as the late (?) Pleistocene, and an east-northeast structure, probably a right-lateral fault. Deep circulation of ground water in this region of relatively high heat flow and upwelling along faults is the probable cause of the thermal anomaly.

Laboratory-Measured and Property-Transfer Modeled Saturated Hydraulic Conductivity of Snake River Plain Aquifer Sediments at the Idaho National Laboratory, Idaho

USGS Publications Warehouse

Perkins, Kim S.

2008-01-01

Sediments are believed to comprise as much as 50 percent of the Snake River Plain aquifer thickness in some locations within the Idaho National Laboratory. However, the hydraulic properties of these deep sediments have not been well characterized and they are not represented explicitly in the current conceptual model of subregional scale ground-water flow. The purpose of this study is to evaluate the nature of the sedimentary material within the aquifer and to test the applicability of a site-specific property-transfer model developed for the sedimentary interbeds of the unsaturated zone. Saturated hydraulic conductivity (Ksat) was measured for 10 core samples from sedimentary interbeds within the Snake River Plain aquifer and also estimated using the property-transfer model. The property-transfer model for predicting Ksat was previously developed using a multiple linear-regression technique with bulk physical-property measurements (bulk density [pbulk], the median particle diameter, and the uniformity coefficient) as the explanatory variables. The model systematically underestimates Ksat,typically by about a factor of 10, which likely is due to higher bulk-density values for the aquifer samples compared to the samples from the unsaturated zone upon which the model was developed. Linear relations between the logarithm of Ksat and pbulk also were explored for comparison.