Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

NASA Astrophysics Data System (ADS)

Liu, C.; Liu, J.; Hu, Y.; Zheng, C.

2015-05-01

Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

Spatial distribution and output characteristics of nonpoint source pollution in the Dongjiang River basin in south China

NASA Astrophysics Data System (ADS)

Rong, Q. Q.; Su, M. R.; Yang, Z. F.; Cai, Y. P.; Yue, W. C.; Dang, Z.

2018-02-01

In this research, the Dongjiang River basin was taken as the study area to analyze the spatial distribution and output characteristics of nonpoint source pollution, based on the export coefficient model. The results showed that the annual total nitrogen and phosphorus (i.e. TN and TP) loads from the Dongjiang River basin were 67916114.6 and 7215279.707 kg, respectively. Residents, forestland and pig were the main contributors for the TN load in the Dongjiang River basin, while residents, forestland and rainfed croplands were the three largest contributors for the TP load. The NPS pollution had a significant spatial variation in this area. The pollution loads overall decreased from the northeast to the southwest part of the basin. Also, the pollution loads from the gentle slope area were larger than those from steep slope areas. Among the ten tributary watersheds in the Dongjiang River basin, the TN and TP loads from the Hanxi River watershed were the largest. On the contrary, the Gongzhuang River watershed contributed least to the total pollution loads of the Dongjiang River basin. For the average pollution load intensities, Hanxi River watershed was still the largest. However, the smallest average TN and TP load intensities were in the Xinfeng River watershed.

A Water Resources Management Model to Evaluate Climate Change Impacts in North-Patagonia, Argentina

NASA Astrophysics Data System (ADS)

Bucciarelli, L. F.; Losano, F. T.; Marizza, M.; Cello, P.; Forni, L.; Young, C. A.; Girardin, L. O.; Nadal, G.; Lallana, F.; Godoy, S.; Vallejos, R.

2014-12-01

Most recently developed climate scenarios indicate a potential future increase in water stress in the region of Comahue, located in the North-Patagonia, Argentina. This region covers about 140,000 km2 where the Limay River and the Neuquén River converge into the Negro River, constituting the largest integrated basins in Argentina providing various uses of water resources: a) hydropower generation, contributing 15% of the national electricity market; b) fruit-horticultural products for local markets and export; c) human and industrial water supply; d) mining and oil exploitation, including Vaca Muerta, second world largest reserves of shale gas and fourth world largest reserves of shale-oil. The span of multiple jurisdictions and the convergence of various uses of water resources are a challenge for integrated understanding of economically and politically driven resource use activities on the natural system. The impacts of climate change on the system could lead to water resource conflicts between the different political actors and stakeholders. This paper presents the results of a hydrological simulation of the Limay river and Neuquén river basins using WEAP (Water Evaluation and Planning) considering the operation of artificial reservoirs located downstream at a monthly time step. This study aims to support policy makers via integrated tools for water-energy planning under climate uncertainties, and to facilitate the formulation of water policy-related actions for future water stress adaptation. The value of the integrated resource use model is that it can support local policy makers understand the implications of resource use trade-offs under a changing climate: 1) water availability to meet future growing demand for irrigated areas; 2) water supply for hydropower production; 3) increasing demand of water for mining and extraction of unconventional oil; 4) potential resource use conflicts and impacts on vulnerable populations.

Pollution of the River Niger and its main tributaries

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

Nwokedi, G.I.C.; Obodo, G.A.

1993-08-01

The River Niger system, with a length of about 4200 kilometers, and a discharge volume of 190 cubic kilometers, per year is the third largest river in Africa, and the largest in West Africa. It serves as an important waterway for the transportation of goods and provides rich agricultural flood basins for the cultivation of food and vegetables. Also it is a major source of animal proteins in form of fishes, snails and other aquatics. Above all the River and its tributaries represent the main source of domestic water supply for the rural communities, and water for irrigation. Therefore theremore » is a need to establish the nature and present levels of pollutants in the river, and the contribution made by the tributaries to the gross pollution level. A number of studies have been reported. Martins reported on the geochemistry of the River Niger while Nriagu; Livingstone; and Imevbore provided some chemical data on the upper reaches around and above its confluence with River Benue at Lokoja. Ajayi and Osibanjo reported on the chemical properties of some tributaries above the confluence of the Niger and the Benue. So far no work has been reported on the lower reaches of the Niger where contributions of the Benue and other major tributaries are significant, and where there are large settlements on its banks and the banks of the tributaries. This work aims at establishing base-line levels of the various pollutants and their sources. 12 refs., 1 fig., 2 tabs.« less

Martian deltas: Morphology and distribution

NASA Technical Reports Server (NTRS)

Rice, J. W., Jr.; Scott, D. H.

1993-01-01

Recent detailed mapping has revealed numerous examples of Martian deltas. The location and morphology of these deltas are described. Factors that contribute to delta morphology are river regime, coastal processes, structural stability, and climate. The largest delta systems on Mars are located near the mouths of Maja, Maumee, Vedra, Ma'adim, Kasei, and Brazos Valles. There are also several smaller-scale deltas emplaced near channel mouths situated in Ismenius Lacus, Memnonia, and Arabia. Delta morphology was used to reconstruct type, quantity, and sediment load size transported by the debouching channel systems. Methods initially developed for terrestrial systems were used to gain information on the relationships between Martian delta morphology, river regime, and coastal processes.

Location and timing of river-aquifer exchanges in six tributaries to the Columbia River in the Pacific Northwest of the United States

USGS Publications Warehouse

Konrad, C.P.

2006-01-01

The flow of water between rivers and contiguous aquifers influences the quantity and quality of water resources, particularly in regions where precipitation and runoff are unevenly distributed through the year, such as the Columbia Basin (CB) in northwestern United States. Investigations of basin hydrogeology and gains and losses of streamflow for six rivers in the CB were reviewed to characterize general patterns in the timing and location of river-aquifer exchanges at a reach-scale (0.5-150 km) and to identify geologic and geomorphic features associated with the largest exchanges. Ground-water discharge to each river, or the gain in streamflow, was concentrated spatially: more than one-half of the total gains along each river segment were contributed from reaches that represented no more than 30% of the total segment length with the largest and most concentrated gains in rivers in volcanic terrains. Fluvial recharge of aquifers, or losses of streamflow, was largest in rivers in sedimentary basins where unconsolidated sediments form shallow aquifers. Three types of geologic or geomorphic features were associated with the largest exchanges: (1) changes in the thickness of unconsolidated aquifers; (2) contacts between lithologic units that represent contrasts in permeability; and (3) channel forms that increase the hydraulic gradient or cross-sectional area of flow paths between a river and shallow ground-water. The down-valley component of ground-water flow and its vertical convergence on or divergence from a riverbed account for large streamflow gains in some reaches and contrast with the common assumption of lateral ground-water discharge to a river that penetrates completely through the aquifer. Increased ground-water discharge was observed during high-flow periods in reaches of four rivers indicating that changes in ground-water levels can be more important than stage fluctuations in regulating the direction and magnitude of river-aquifer exchanges and that assumptions about ground-water discharge during high flow periods used for base-flow separation must be verified. Given the variety of geologic terrains in the CB, the spatial and temporal patterns of river-aquifer exchanges provide a framework for investigations in other regions that includes a focus on reaches where the largest exchanges are likely to occur, integration of ground-water and surface-water data, and verification of assumptions regarding ground-water flow direction and temporal variation of exchanges. ?? 2006 Elsevier B.V. All rights reserved.

A River Model Intercomparison Project in Preparation for SWOT

NASA Astrophysics Data System (ADS)

David, C. H.; Andreadis, K.; Famiglietti, J. S.; Beighley, E.; Boone, A. A.; Yamazaki, D.; Paiva, R. C. D.; Fleischmann, A. S.; Collischonn, W.; Fisher, C. K.; Kim, H.; Biancamaria, S.

2017-12-01

The Surface Water and Ocean Topography (SWOT) mission is currently scheduled to launch at the beginning of next decade. SWOT is expected to retrieve unprecedented measurements of water extent, elevation, and slope in the largest terrestrial water bodies. Such potential transformative information motivates the investigation of our ability to ingest the associated data into continental-scale models of terrestrial hydrology. In preparation for the expected SWOT observations, an inter-comparison of continental-scale river models is being performed. This comparison experiment focuses on four of the world's largest river basins: the Amazon, the Mississippi, the Niger, and the Saint-Lawrence. This ongoing project focuses on two main research questions: 1) How can we best prepare for the expected SWOT continental to global measurements before SWOT even flies?, and 2) What is the added value of including SWOT terrestrial measurements into global hydro models for enhancing our understanding of the terrestrial water cycle and the climate system? We present here the results of the second year of this project which now includes simulations from six numerical models of rivers over the Mississippi and sheds light on the implications of various modeling choices on simulation quality as well as on the potential impact of SWOT observations.

[Genetic Differentiation of Sockeye Salmon Oncorhynchus nerka from Kamchatka River Basin and the Lake-River Systems of the West Coast of the Bering Sea as Inferred from Data on Single Nucleotide Polymorphism].

PubMed

Khrustaleva, A M; Klovach, N V; Vedischeva, E V; Seeb, J E

2015-10-01

The variability of 45 single nucleotide polymorphism loci (SNP) was studied in sockeye salmon from the Kamchatka River basin and four lake-river systems of the west coast of the Bering Sea. Based on the genetic differentiation estimates for the largest sockeye salmon populations of Eastern Kamchatka and Chukotka, the examined samples were combined into two regional groups represented by the population of the Kamchatka River drainage, which included numerous local subpopulations and seasonal races, and the northern population grouping from the rivers of Olutorsko-Navarinsky raion, wherein the sockeye salmon from Maynypilginskaya Lake-River system was relatively isolated. Considerable divergence was observed between the island (Sarannoe Lake, Bering Island) and continental populations. Genetic heterogeneity was revealed and groups of early- and late-maturing individuals were isolated in the sample of late-run sockeye salmon from Kamchatka River. In Apuka River, subdivision of the spawning run into two genetically distinct spatial and temporal groupings was also observed. The results suggest that the differentiation of sockeye salmon samples by single nucleotide substitution frequencies was largely due to differences in the direction and strength of local selection at some loci in the population complexes and intrapopulation groupings from the examined river basins of Eastern Kamchatka, Chukotka, and Commander Islands.

Backwater effects in the Amazon River basin of Brazil

USGS Publications Warehouse

Meade, R.H.; Rayol, J.M.; Da Conceicao, S.C.; Natividade, J.R.G.

1991-01-01

The Amazon River mainstem of Brazil is so regulated by differences in the timing of tributary inputs and by seasonal storage of water on floodplains that maximum discharges exceed minimum discharges by a factor of only 3. Large tributaries that drain the southern Amazon River basin reach their peak discharges two months earlier than does the mainstem. The resulting backwater in the lowermost 800 km of two large southern tributaries, the Madeira and Puru??s rivers, causes falling river stages to be as much as 2-3 m higher than rising stages at any given discharge. Large tributaries that drain the northernmost Amazon River basin reach their annual minimum discharges three to four months later than does the mainstem. In the lowermost 300-400 km of the Negro River, the largest northern tributary and the fifth largest river in the world, the lowest stages of the year correspond to those of the Amazon River mainstem rather than to those in the upstream reaches of the Negro River. ?? 1991 Springer-Verlag New York Inc.

Inorganic and organic carbon spatial variability in the Congo River during high waters (December 2013)

NASA Astrophysics Data System (ADS)

Borges, Alberto V.; Bouillon, Steven; Teodoru, Cristian; Leporcq, Bruno; Descy, Jean-Pïerre; Darchambeau, François

2014-05-01

Rivers are important components of the global carbon cycle, as they transport terrestrial organic matter from the land to the sea, and emit CO2 to the atmosphere. In particular, tropical systems that account for 60% of global freshwater discharge to the oceans. In contrast with south American rivers, very little information is available for African rivers on their carbon flows and stocks, in particular the Congo river, the second largest river in the World in terms of freshwater discharge (1457 km3 yr-1) and in terms of drainage basin (3.75 106 km2) located the second largest tropical forest in the World. Here, we report a data-set of continuous (every minute) records of the partial pressure of CO2 (pCO2) (total of 10,000 records), and discrete samples of particulate (POC) and dissolved (DOC) organic carbon (total of 75 samples) in the mainstem and major tributaries of the Congo river, along the 1700 km stretch from Kisangani to Kinshasa (total river length = 4374 km), during the high water period (December 2013). The pCO2 dynamic range was high ranging from minimum values of 2000 ppm in white waters tributaries (higher turbidity, conductivity and O2, lower DOC), up to maximal values of 18,000 ppm in blackwaters tributaries (lower turbidity, conductivity and O2, higher DOC). In the mainstem, very strong horizontal (cross-section) gradients were imposed by the presence of blackwaters close to the riverbanks and the presence of whitewaters in the middle of the river. In the mainstem, a distinct horizontal (longitudinal) pattern was observed with pCO2 increasing, and conductivity and turbidity decreasing downstream.

Emerging and Conventional Contaminants in River Waters Discharging into the Black Sea along the Ukrainian Coast

EPA Science Inventory

The major rivers of Ukraine, including the Dnieper, Dniester, Southern Bug and Danube, discharge approximately 8500 m3/s of freshwater into the northern and western portions of the Black Sea. As one of the largest countries in Europe, Ukraine also has one of the largest human po...

Suspended-sediment loads from major tributaries to the Missouri River between Garrison Dam and Lake Oahe, North Dakota, 1954-98

USGS Publications Warehouse

Macek-Rowland, Kathleen M.

2000-01-01

Annual suspended-sediment loads for water years 1954 through 1998 were estimated for the major tributaries in the Missouri River Basin between Garrison Dam and Lake Oahe in North Dakota and for the Missouri River at Garrison Dam and the Missouri River at Bismarck, N. Dak.  The major tributaries are the Knife River, Turtle Creek, Painted Woods Creek, Square Butte Creek, Burnt Creek, Heart River, and Apple Creek.  Sediment and streamflow data used to estimate the suspended-sediment loads were from selected U.S. Geological Survey streamflow-gaging stations located within each basin.  Some of the stations had no sediment data available and limited continuous streamflow data for water years 1954 through 1998.  Therefore, data from nearby streamflow-gaging stations were assumed for the calculations. The Heart River contributed the largest amount of suspended sediment to the Missouri River for 1954-98.  Annual suspended-sediment loads in the Heart River near Mandan ranged from less than 1 to 40 percent of the annual suspended-sediment load in the Missouri River. The Knife River contributed the second largest amount of suspended sediment to the Missouri River.  Annual suspended-sediment loads in the Knife River at Hazen ranged from less than 1 to 19 percent of the annual suspended-sediment load in the Missouri River.  Apple Creek, Turtle Creek, Painted Woods Creek, Square Butte Creek, and Burnt Creek all contributed 2 percent or less of the annual suspended-sediment load in the Missouri River.  The Knife River and the Heart River also had the largest average suspended-sediment yields for the seven tributaries.  The yield for the Knife River was 91.1 tons per square mile, and the yield for the Heart River was 133 tons per square mile.  The remaining five tributaries had yields of less than 24 tons per square mile based on total drainage area. 

Chesapeake Bay as seen from STS-58

NASA Image and Video Library

1993-10-30

STS058-81-049 (18 Oct-1 Nov 1993) --- This view encompasses most of the large estuarine system of the Chesapeake Bay. The farmland and marshes of eastern shores of the Chesapeake (eastern Maryland and Virginia) are the foreground. The largest tributary flowing into the Bay is the Potomac River; Washington, D.C. is visible where the river bends to the northwest. The urban-suburban corridor between Washington, D.C. and Baltimore to the north (toward the right on this view) shows well as the gray zone which extends from left (D.C. on the Potomac) to right (Baltimore on the Patapsco River embayment on the Chesapeake, near the upper right).

Tracking the deployment of the integrated metropolitan ITS infrastructure in Providence, Pawtucket, Fall River : FY99 results

DOT National Transportation Integrated Search

1999-01-01

In January 1996, Secretary Pea set a goal of deploying the integrated metropolitan Intelligent Transportation System (ITS) infrastructure in 75 of the nations largest metropolitan areas by 2006. In 1997, the U.S. Department of Transportation ini...

Floods of May 30 to June 15, 2008, in the Iowa and Cedar River basins, eastern Iowa

USGS Publications Warehouse

Linhart, Mike S.; Eash, David A.

2010-01-01

As a result of prolonged and intense periods of rainfall in late May and early June, 2008, along with heavier than normal snowpack the previous winter, record flooding occurred in Iowa in the Iowa River and Cedar River Basins. The storms were part of an exceptionally wet period from May 29 through June 12, when an Iowa statewide average of 9.03 inches of rain fell; the normal statewide average for the same period is 2.45 inches. From May 29 to June 13, the 16-day rainfall totals recorded at rain gages in Iowa Falls and Clutier were 14.00 and 13.83 inches, respectively. Within the Iowa River Basin, peak discharges of 51,000 cubic feet per second (flood-probability estimate of 0.2 to 1 percent) at the 05453100 Iowa River at Marengo, Iowa streamflow-gaging station (streamgage) on June 12, and of 39,900 cubic feet per second (flood-probability estimate of 0.2 to 1 percent) at the 05453520 Iowa River below Coralville Dam near Coralville, Iowa streamgage on June 15 are the largest floods on record for those sites. A peak discharge of 41,100 cubic feet per second (flood-probability estimate of 0.2 to 1 percent) on June 15 at the 05454500 Iowa River at Iowa City, Iowa streamgage is the fourth highest on record, but is the largest flood since regulation by the Coralville Dam began in 1958. Within the Cedar River Basin, the May 30 to June 15, 2008, flood is the largest on record at all six streamgages in Iowa located on the mainstem of the Cedar River and at five streamgages located on the major tributaries. Flood-probability estimates for 10 of these 11 streamgages are less than 1 percent. Peak discharges of 112,000 cubic feet per second (flood-probability estimate of 0.2 to 1 percent) at the 05464000 Cedar River at Waterloo, Iowa streamgage on June 11 and of 140,000 cubic feet per second (flood-probability estimate of less than 0.2 percent) at the 05464500 Cedar River at Cedar Rapids, Iowa streamgage on June 13 are the largest floods on record for those sites. Downstream from the confluence of the Iowa and Cedar Rivers, the peak discharge of 188,000 cubic feet per second (flood-probability estimate of less than 0.2 percent) at the 05465500 Iowa River at Wapello, Iowa streamgage on June 14, 2008, is the largest flood on record in the Iowa River and Cedar River Basins since 1903. High-water marks were measured at 88 locations along the Iowa River between State Highway 99 near Oakville and U.S. Highway 69 in Belmond, a distance of 319 river miles. High-water marks were measured at 127 locations along the Cedar River between Fredonia near the mouth (confluence with the Iowa River) and Riverview Drive north of Charles City, a distance of 236 river miles. The high-water marks were used to develop flood profiles for the Iowa and Cedar River.

The effects of Missouri River mainstem reservoir system operations on 2011 flooding using a Precipitation-Runoff Modeling System model: Chapter K in 2011 Floods of the Central United States

USGS Publications Warehouse

Haj, Adel E.; Christiansen, Daniel E.; Viger, Roland J.

2014-01-01

In 2011 the Missouri River Mainstem Reservoir System (Reservoir System) experienced the largest volume of flood waters since the initiation of record-keeping in the nineteenth century. The high levels of runoff from both snowpack and rainfall stressed the Reservoir System’s capacity to control flood waters and caused massive damage and disruption along the river. The flooding and resulting damage along the Missouri River brought increased public attention to the U.S. Army Corps of Engineers (USACE) operation of the Reservoir System. To help understand the effects of Reservoir System operation on the 2011 Missouri River flood flows, the U.S. Geological Survey Precipitation-Runoff Modeling System was used to construct a model of the Missouri River Basin to simulate flows at streamgages and dam locations with the effects of Reservoir System operation (regulation) on flow removed. Statistical tests indicate that the Missouri River Precipitation-Runoff Modeling System model is a good fit for high-flow monthly and annual stream flow estimation. A comparison of simulated unregulated flows and measured regulated flows show that regulation greatly reduced spring peak flow events, consolidated two summer peak flow events to one with a markedly decreased magnitude, and maintained higher than normal base flow beyond the end of water year 2011. Further comparison of results indicate that without regulation, flows greater than those measured would have occurred and been sustained for much longer, frequently in excess of 30 days, and flooding associated with high-flow events would have been more severe.

Connecticut permanent long-term bridge monitoring network, volume 5 : wireless monitoring of the hung span in a large truss bridge - I-95 NB over the Thames River in New London (bridge #3819).

DOT National Transportation Integrated Search

2014-08-01

This report describes the instrumentation and data acquisition for the center hung segment in the largest : truss bridge in Connecticut, located on the interstate system. The monitoring system was developed as a : joint effort between researchers at ...

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.

The Pleistocene rivers of the English Channel region

NASA Astrophysics Data System (ADS)

Antoine, Pierre; Coutard, Jean-Pierre; Gibbard, Philip; Hallegouet, Bernard; Lautridou, Jean-Pierre; Ozouf, Jean-Claude

2003-02-01

The Pleistocene history of river systems that enter the English Channel from northern France and southern England is reviewed. During periods of low sea-level (cold stages) these streams were tributaries of the Channel River. In southern England the largest, the River Solent, is an axial stream that has drained the Hampshire Basin from the Early Pleistocene or late Pliocene. Other streams of southern England may be of similar antiquity but their records are generally short and their sedimentary history have been destroyed, as in northern Brittany, by coastal erosion and valley deepening as a consequence of tectonic uplift. In northern France, the Seine and Somme rivers have very well developed terrace systems recording incision that began at around 1 Ma. The uplift rate, deduced from the study of these terrace systems, is of 55 to 60 m myr-1 since the end of the Early Pleistocene. Generally the facies and sedimentary structures indicate that the bulk of the deposits in these rivers accumulated in braided river environments under periglacial climates in all the area around the Channel. Evolution of the rivers reflects their responses to climatic change, local geological structure and long-term tectonic activity. In this context the Middle Somme valley is characterised by a regular pattern in which incision occurs at the beginning of each glacial period within a general background of uplift. Nevertheless the response of the different rivers to climatic variations, uplift and sea-level changes is complex and variable according to the different parts of the river courses.

Hydrologic conditions and hazards in the Kennicott River basin, Wrangell-St. Elias National Park Preserve, Alaska

USGS Publications Warehouse

Rickman, R.L.; Rosenkrans, D.S.

1997-01-01

McCarthy, Alaska, is on the Kennicott River, about 1 mile from the terminus of Kennicott Glacier in the Wrangell-St. Elias National Park and Preserve. Most visitors to McCarthy and the park cross the West Fork Kennicott River using a hand-pulled tram and cross the East Fork Kennicott River on a temporary footbridge. Outburst floods from glacier-dammed lakes result in channel erosion, aggradation, and migration of the Kennicott River, which disrupt transportation links, destroy property, and threaten life. Hidden Creek Lake, the largest of six glacier-dammed lakes in the Kennicott River Basin, has annual outbursts that cause the largest floods on the Kennicott River. Outbursts from Hidden Creek Lake occur from early fall to mid-summer, and lake levels at the onset of the outbursts have declined between 1909 and 1995. Criteria for impending outbursts for Hidden Creek Lake include lake stage near or above 3,000 to 3,020 feet, stationary or declining lake stage, evidence of recent calving of large ice blocks from the ice margin, slush ice and small icebergs stranded on the lakeshore, and fresh fractures in the ice-margin region. The lower Kennicott Glacier has thinned and retreated since about 1860. The East and West Fork Kennicott River channels migrated in response to changes in the lower Kennicott Glacier. The largest channel changes occur during outburst floods from Hidden Creek Lake, whereas channel changes from the other glacier-dammed lake outbursts are small. Each year, the West Fork Kennicott River conveys a larger percentage of the Kennicott Glacier drainage than it did the previous year. Outburst floods on the Kennicott River cause the river stage to rise over a period of several hours. Smaller spike peaks have a very rapid stage rise. Potential flood magnitude was estimated by combining known maximum discharges from Hidden Creek Lake and Lake Erie outburst floods with a theoretical large regional flood. Flood hazard areas at the transportation corridor were delineated, and possible future geomorphological changes were hypothesized. McCarthy, Alaska, is on the Kennicott River, about 1 mile from the terminus of Kennicott Glacier in the Wrangell-St. Elias National Park and Preserve. Most visitors to McCarthy and the park cross the West Fork Kennicott River using a hand-pulled tram and cross the East Fork Kennicott River on a temporary footbridge. Outburst floods from glacier-dammed lakes result in channel erosion, aggradation, and migration of the Kennicott River, which disrupt transportation links, destroy property, and threaten life. Hidden Creek Lake, the largest of six glacier-dammed lakes in the Kennicott River Basin, has annual outbursts that cause the largest floods on the Kennicott River. Outbursts from Hidden Creek Lake occur from early fall to mid-summer, and lake levels at the onset of the outbursts have declined between 1909 and 1995. Criteria for impending outbursts for Hidden Creek Lake include lake stage near or above 3,000 to 3,020 feet, stationary or declining lake stage, evidence of recent calving of large ice blocks from the ice margin, slush ice and small icebergs stranded on the lakeshore, and fresh fractures in the ice-margin region. The lower Kennicott Glacier has thinned and retreated since about 1860. The East and West Fork Kennicott River channels migrated in response to changes in the lower Kennicott Glacier. The largest channel changes occur during outburst floods from Hidden Creek Lake, whereas channel changes from the other glacier-dammed lake outbursts are small. Each year, the West Fork Kennicott River conveys a larger percentage of the Kennicott Glacier drainage than it did the previous year. Outburst floods on the Kennicott River cause the river stage to rise over a period of several hours. Smaller spike peaks have a very rapid stage rise. Potential flood magnitude was estimated by combining known maximum discharges from Hidden Creek Lake and Lake Erie outburst floods with

Modelling impacts of climate change and socio-economic change on the Ganga, Brahmaputra, Meghna, Hooghly and Mahanadi river systems in India and Bangladesh.

PubMed

Whitehead, Paul G; Jin, Li; Macadam, Ian; Janes, Tamara; Sarkar, Sananda; Rodda, Harvey J E; Sinha, Rajiv; Nicholls, Robert J

2018-09-15

The Ganga-Brahmaputra-Meghna (GBM) River System, the associated Hooghly River and the Mahanadi River System represent the largest river basins in the world serving a population of over 780 million. The rivers are of vital concern to India and Bangladesh as they provide fresh water for people, agriculture, industry, conservation and support the Delta System in the Bay of Bengal. Future changes in both climate and socio-economics have been investigated to assess whether these will alter river flows and water quality. Climate datasets downscaled from three different Global Climate Models have been used to drive a daily process based flow and water quality model. The results suggest that due to climate change the flows will increase in the monsoon period and also be enhanced in the dry season. However, once socio-economic changes are also considered, increased population, irrigation, water use and industrial development reduce water availability in drought conditions, threatening water supplies and posing a threat to river and coastal ecosystems. This study, as part of the DECCMA (Deltas, vulnerability and Climate Change: Migration and Adaptation) project, also addresses water quality issues, particularly nutrients (N and P) and their transport along the rivers and discharge into the Delta System. Climate will alter flows, increasing flood flows and changing pollution dilution factors in the rivers, as well as other key processes controlling water quality. Socio-economic change will affect water quality, as water diversion strategies, increased population and industrial development alter the water balance and enhance fluxes of nutrients from agriculture, urban centers and atmospheric deposition. Copyright © 2018 Elsevier B.V. All rights reserved.

Carbon fate in a large temperate human-impacted river system: Focus on benthic dynamics

NASA Astrophysics Data System (ADS)

Vilmin, Lauriane; Flipo, Nicolas; Escoffier, Nicolas; Rocher, Vincent; Groleau, Alexis

2016-07-01

Fluvial networks play an important role in regional and global carbon (C) budgets. The Seine River, from the Paris urban area to the entrance of its estuary (220 km), is studied here as an example of a large human-impacted river system subject to temperate climatic conditions. We assess organic C (OC) budgets upstream and downstream from one of the world's largest wastewater treatment plants and for different hydrological conditions using a hydrobiogeochemical model. The fine representation of sediment accumulation on the river bed allows for the quantification of pelagic and benthic effects on OC export toward the estuary and on river metabolism (i.e., net CO2 production). OC export is significantly affected by benthic dynamics during the driest periods, when 25% of the inputs to the system is transformed or stored in the sediment layer. Benthic processes also substantially affect river metabolism under any hydrological condition. On average, benthic respiration accounts for one third of the total river respiration along the studied stretch (0.27 out of 0.86 g C m-2 d-1). Even though the importance of benthic processes was already acknowledged by the scientific community for headwater streams, these results stress the major influence of benthic dynamics, and thus of physical processes such as sedimentation and resuspension, on C cycling in downstream river systems. It opens the door to new developments in the quantification of C emissions by global models, whereby biogeochemical processing and benthic dynamics should be taken into account.

Water-quality conditions of the lower Boise River, Ada and Canyon Counties, Idaho, May 1994 through February 1997

USGS Publications Warehouse

Mullins, William H.

1998-01-01

Agricultural land and water use, wastewater treatment facility discharges, land development, road construction, urban runoff, confined-animal feeding operations, reservoir operations, and river channelization affect the water quality and biotic integrity of the lower Boise River between Lucky Peak Dam and the river's mouth at Parma, Idaho. During May 1994 through February 1997, 4 sites on the Boise River, 12 tributary/drain sites, and 3 wastewater treatment facilities were sampled at various intervals during the irrigation (high-flow) and post-irrigation (low-flow) seasons to determine sources, concentrations, and relative loads of nutrients and suspended sediment. Discharge entering the Boise River from the 12 tributary/drain sites and 3 wastewater treatment facilities was measured to determine the nutrient loads being contributed from each source. Total nitrogen, total phosphorus, and suspended sediment concentrations and loads tended to increase in a downstream direction along the Boise River. Among the 15 sources of discharge to the Boise River, 3 southside tributary/drains and the West Boise wastewater treatment facility contributed the largest loads of total nitrogen; the median daily load was more than 2,000 pounds per day. The West Boise wastewater treatment facility contributed the largest median daily load of total phosphorus (810 pounds per day); Dixie Drain contributed the largest median daily load of suspended sediment (26.4 tons per day). Nitrogen-to-phosphorus ratios at the four Boise River sites indicated that phosphorus could be limiting algal growth at the Diversion Dam site, whereas nitrogen could be limiting algal growth at the Glenwood and Middleton sites during some parts of the year. Algal growth in the Boise River near Parma did not appear to be nutrient limited. Because of the complexity of the plumbing system in the lower Boise River (numerous diversions and inflow points), accurate comparisons between discharge and nutrient loads entering the river at measured sites during high-flow sampling periods were difficult. During low-flow sampling periods, southside tributary/drains contributed most of the discharge and total nitrogen load, and wastewater treatment facilities contributed most of the total phosphorus load to the Boise River. During the 50-day period July 18 through September 5, 1996, the Idaho State standard for maximum daily average temperature for coldwater biota was exceeded by 34 percent at Middleton, 48 percent at Caldwell, and 80 percent near Parma. Violations of State standards for primary and secondary contact recreation were observed at all tributary/ drains and in the Boise River near Parma. Median instantaneous concentrations of fecal coliform bacteria exceeded State standards for primary contact recreation at five tributary/drains and exceeded standards for secondary contact recreation at one tributary/drain (Dixie Drain).

Predation by fallfish (Semotilus corporalis) on Pacific salmon eggs in the Salmon River, New York

USGS Publications Warehouse

Johnson, J. H.; Nack, C.C.; Chalupnicki, M.A.

2009-01-01

Fallfish (Semotilus corporalis) are the largest native cyprinid in the northeastern United States and are the most abundant native species in the Salmon River, New York. The Salmon River is a high-quality spawning and nursery river for Pacific salmon (Oncorhynchus spp.) migrating from Lake Ontario. Because of the large number of Pacific salmon spawning in the river in the fall extensive redd superimposition occurs resulting in salmonid eggs being available on the substrate. We examined the fall diet of 647 fallfish in 2007 and 2008 to determine the extent of predation on Pacific salmon eggs. The contribution of eggs in the diet significantly increased once fallfish attained a size of 100 mm total length. The largest size category of fallfish examined (≥150 mm) had the highest proportion (86.1%) of salmon eggs in their diet. The contribution of Zooplankton and chironomids in the diet of fallfish decreased with fish size. Except for the two largest groups of fallfish examined (i.e., 100–149 mm and ≥150 mm) diet overlap among size groups was low. The high contribution in the diet during the fall and high caloric value of Pacific salmon eggs could increase growth and survival of this species in the Salmon River.

Geochemical evidence for an Eolian sand dam across the North and South Platte rivers in Nebraska

USGS Publications Warehouse

Muhs, Daniel R.; Swinehart, James B.; Loope, David B.; Been, Josh; Mahan, Shannon; Bush, Charles A.

2000-01-01

Geochemical and geomorphic data from dune fields in southwestern Nebraska provide new evidence that the Nebraska Sand Hills once migrated across the North and South Platte rivers and dammed the largest tributary system to the Missouri River. The Lincoln County and Imperial dune fields, which lie downwind of the South Platte River, have compositions intermediate between the Nebraska Sand Hills (quartz-rich) and northeastern Colorado dunes (K-feldspar-rich). The most likely explanation for the intermediate composition is that the Lincoln County and Imperial dunes are derived in part from the Nebraska Sand Hills and in part from the South Platte River. The only mechanism by which the Nebraska Sand Hills could have migrated this far south is by complete infilling of what were probably perennially dry North Platte and South Platte river valleys. Such a series of events would have required an extended drought, both for activation of eolian sand and decreased discharges in the Platte River system. A nearby major tributary of the North Platte River is postulated to have been blocked by eolian sand about 12,000 14C yr B.P. We propose that an eolian sand dam across the Plattes was constructed at about this same time.

RIVERINE RESTORATION STRATEGIES: PATTERN AND PROCESS IN A LARGE ALLUVIAL RIVER

EPA Science Inventory

The Willamette River in western Oregon is the tenth largest river in the conterminous U. S. Plans being developed to restore ecological function to the main corridor of the river. Our riverine research has developed a basic understanding of some of the ecological functions and ...

Weak Effects of Urbanization on Macroinvertebrate Assemblages in Mid-continent, USA, Great Rivers

EPA Science Inventory

Effects of urbanization on rivers are not well studied in the US, especially for our largest rivers. We compared the macroinvertebrate assemblages on snags and in the littoral benthos between urban and non-urban reaches of the Upper Mississippi and Lower Missouri Rivers. We used ...

Zooplankton Linkages between Rivers and Great Lakes: Case Study from the St. Louis River

EPA Science Inventory

In this case study, we characterized the spatial and seasonal distribution and abundance of zooplankton within the hydrologically complex drowned river mouth of the St. Louis River, the second largest tributary to Lake Superior and an important fish nursery. We hypothesize that z...

Evidence of natural reproduction by Muskellunge in middle Tennessee rivers

USGS Publications Warehouse

Warren, Lila H.; Bettoli, Phillip William

2014-01-01

Native Esox masquinongy (Muskellunge) in the Cumberland River drainage, TN, were nearly extirpated in the 1970s due to decades of over-fishing and habitat degradation from coal mining, logging, and other land-use practices. In an effort to preserve the species in that drainage, a stocking program began in 1976 in the upper Caney Fork River system in middle Tennessee where Muskellunge were not native. A trophy Muskellunge fishery eventually developed, but it was unknown whether Muskellunge were reproducing in the upper Caney Fork River system or whether the fishery was wholly dependent on the stocking program. To establish evidence of natural reproduction, we used seines, backpack electrofishing, and boat electrofishing gear in 2012 to find age-0 Muskellunge in the upper Caney Fork River system. Natural reproduction of Muskellunge was documented in the mainstem Caney Fork River above Great Falls Dam and in 3 of its 4 major tributaries. Seventeen age-0 Muskellunge were collected and one other was observed, but not handled. Age-0 Muskellunge grew rapidly (1.80–2.34 mm/day), and the largest fish collected during the study reached a total length of 399 mm by 9 October 2012. A cessation of stocking for several years coupled with routine monitoring could reveal whether natural recruitment is sufficient to sustain the fishery.

Estimated withdrawals and use of freshwater in Vermont, 1990

USGS Publications Warehouse

Horn, M.A.; Medalie, Laura

1996-01-01

Estimated freshwater withdrawals during 1990 in Vermont totaled about 632 million gallons per day. The largest withdrawals were for thermoelectric- power generation (82 percent), industrial use (7 percent), and public supply (6 percent). Most withdrawals, 587 million gallons per day, were made from surface-water sources as compared to 44.9 million gallons per day from ground-water sources. The largest withdrawals were in the Upper Connecticut-Mascomo River Basin (525 million gallons per day). About 17,700 million gallons per day were used instream for hydroelectric-poser generation, the largest of which were in the Upper Connecticut-Mascoma and Otter River Basins. Other information describing water-use patters is shown in tables, bar graphs, pie charts, maps, and accompanying text. The data are aggregated by river basin (hydrologic cataloging unit), and all amounts are reports in million gallons per day.

Carbon isotope composition of dissolved humic and fulvic acids in the Tokachi River system.

PubMed

Nagao, Seiya; Kodama, Hiroki; Aramaki, Takafumi; Fujitake, Nobuhide; Uchida, Masao; Shibata, Yasuyuki

2011-07-01

This study reports carbon isotopic ratios (Δ(14)C and δ(13)C) of dissolved humic and fulvic acids in the Tokachi River system, northern Japan. These acids have a refractory feature and they represent the largest fraction of dissolved organic matter in aquatic environments. The acids were isolated using the XAD extraction method from river water samples collected at three sites (on the upper and lower Tokachi River, and from one of its tributaries) in June 2004 and 2005. δ(13)C values were -27.8 to -26.9 ‰ for humic and fulvic acids. On the other hand, the Δ(14)C values ranged from -247 to +26 ‰ and the average values were -170 ± 79 ‰ for humic acid and -44 ± 73 ‰ for fulvic acid. The difference was attributed to the residence time of fulvic acid in the watershed being shorter than that of humic acid. The large variation suggested that humic substances have a different pathway in each watershed environment.

Temporal and Spatial Variation of Water Yield Modulus in the Yangtze River Basin in Recent 60 Years

NASA Astrophysics Data System (ADS)

Shi, Xiaoqing; Weng, Baisha; Qin, Tianling

2018-01-01

The Yangtze River Basin is the largest river basin of Asia and the third largest river basin of the world, the gross water resources amount ranks first in the river basins of the country, and it occupies an important position in the national water resources strategic layout. Under the influence of climate change and human activities, the water cycle has changed. The temporal and spatial distribution of precipitation in the basin is more uneven and the floods are frequent. In order to explore the water yield condition in the Yangtze River Basin, we selected the Water Yield Modulus (WYM) as the evaluation index, then analyzed the temporal and spatial evolution characteristics of the WYM in the Yangtze River Basin by using the climate tendency method and the M-K trend test method. The results showed that the average WYM of the Yangtze River Basin in 1956-2015 are between 103,600 and 1,262,900 m3/km2, with an average value of 562,300 m3/km2, which is greater than the national average value of 295,000 m3/km2. The minimum value appeared in the northwestern part of the Tongtian River district, the maximum value appeared in the northeastern of Dongting Lake district. The rate of change in 1956-2015 is between -0.68/a and 0.79/a, it showed a downward trend in the western part but not significantly, an upward trend in the eastern part reached a significance level of α=0.01. The minimum value appeared in the Tongtian River district, the largest value appeared in the Hangjia Lake district, and the average tendency rate is 0.04/a in the whole basin.

Elwha River dam removal-Rebirth of a river

USGS Publications Warehouse

Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

2011-01-01

After years of planning for the largest project of its kind, the Department of the Interior will begin removal of two dams on the Elwha River, Washington, in September 2011. For nearly 100 years, the Elwha and Glines Canyon Dams have disrupted natural processes, trapping sediment in the reservoirs and blocking fish migrations, which changed the ecology of the river downstream of the dams. All five Pacific salmon species and steelhead-historically present in large numbers-are locally extirpated or persist in critically low numbers. Upstream of the dams, more than 145 kilometers of pristine habitat, protected inside Olympic National Park, awaits the return of salmon populations. As the dams are removed during a 2-3 year project, some of the 19 million cubic meters of entrapped sediment will be carried downstream by the river in the largest controlled release of sediment into a river and marine waters in history. Understanding the changes to the river and coastal habitats, the fate of sediments, and the salmon recolonization of the Elwha River wilderness will provide useful information for society as future dam removals are considered.

Evaluation of social vulnerability to floods in Huaihe River basin: a methodology based on catastrophe theory

NASA Astrophysics Data System (ADS)

You, W. J.; Zhang, Y. L.

2015-08-01

Huaihe River is one of the seven largest rivers in China, in which floods occurred frequently. Disasters cause huge casualties and property losses to the basin, and also make it famous for high social vulnerability to floods. Based on the latest social-economic data, the index system of social vulnerability to floods was constructed, and Catastrophe theory method was used in the assessment process. The conclusion shows that social vulnerability as a basic attribute attached to urban environment, with significant changes from city to city across the Huaihe River basin. Different distribution characteristics are present in population, economy, flood prevention vulnerability. It is important to make further development of social vulnerability, which will play a positive role in disaster prevention, improvement of comprehensive ability to respond to disasters.

Geochemical loading of suspended sediment carried by large monsoonal rivers in Burma

NASA Astrophysics Data System (ADS)

Robinson, R. A.; Tipper, E.; Bird, M. I.; Oo, N.

2013-12-01

The Irrawaddy and Salween rivers of Burma drain the most rapidly exhuming region in the Himalayas, the eastern syntaxis zone. These monsoonal rivers have catchment areas of 0.413 x 106 km2 and 0.272 x 106 km2, respectively, and approximately 95% of the Irrawaddy catchment lies within Burma, while the catchment of the Salween flows through China, Thailand and Burma. They are long rivers (~2000 and ~2800 km) which have steep and narrow bedrock gorges along much of their length, and different amounts of floodplain in their lower reaches. These rivers have been less studied than other large Asian systems because of political instability in Burma and restricted access. Based on available historical data, and field work in 2005-2008, Robinson et al. (2007) estimated that the Irrawaddy is likely to be the 3rd largest river globally in terms of sediment load and when the Irrawaddy and Salween estimated fluxes are combined, they together contribute 4.6 Mt/yr of particulate organic carbon (POC) and an additional 1.1Mt/yr of dissolved organic carbon (DOC) to the ocean. When estimated yields of total organic carbon are calculated, the Irrawaddy-Salween system ranks alongside the Amazon as one of the largest yields of organic carbon, and is higher than the yield for the Ganges-Brahmaptura (Bird et al., 2008). Here we present preliminary geochemical data for water and sediment from the Irrawaddy and Salween rivers, and demonstrate the variability in elemental concentrations of water between the rivers and the summer and winter monsoon seasons, and differences in suspended sediment geochemistry as a function of water depth. The variability and magnitude of weathering products carried by such significant systems need to be quantified in order to understand their contribution to global element cycling (Tipper et al., 2006) and sedimentary depocentres. Our data highlight that further study of the geochemistry of such large rivers will significantly improve our understanding of the processes controlling the transport of elements (including carbon) within the fluvial system and their export from land to the ocean, the degree of chemical weathering that occurs during transport, and how the sedimentary geochemistry of depocentres might be better interrogated to understand their record of chemical weathering and relationship to source and transport history. References Bird M.I., Robinson R.A.J., et al. (2008) A preliminary estimate of organic carbon transport by the Ayerawady (Irrawaddy) and Thanlwin (Salween) Rivers of Myanmar. Quaternary International, 186, 113-22. Robinson, R.A.J., Bird, M.I. et al. (2007) The Ayeyarwady River sediment budget to the Indian Ocean: the original 19th Century data revisited. Journal of Geology, 115, doi:10.1086/521607. Tipper E.T. et al. (2006) The short term climatic sensitivity of carbonate and silicate weathering fluxes: Insight from seasonal variations in river chemistry. Geochim. Cosmochim. Act. doi:10.1016/j.gca.2006.03.005.

Water withdrawals in Florida, 2012

USGS Publications Warehouse

Marella, Richard L.

2015-09-01

The largest percentage of freshwater withdrawals was from the South Florida Water Management District (46 percent), followed by the St. Johns River Water Management District (20 percent), Southwest Florida Water Management District (19 percent), Northwest Florida Water Management District (9 percent), and Suwannee River Water Management District (6 percent). The South Florida Water Management District accounted for the largest percentage of freshwater withdrawals for public-supply use (46 percent), commercial-industrial-mining self-supplied use (24 percent), agricultural self-supplied use (59 percent), and recreational-landscape irrigation use (63 percent). The Northwest Florida Water Management District accounted for the largest percentage of freshwater withdrawals for power-generation use (44 percent), and the Southwest Florida Water Management District accounted for the largest percentage of saline-water withdrawals for power-generation use (58 percent).

Concentrations, loads, and yields of total phosphorus, total nitrogen, and suspended sediment and bacteria concentrations in the Wister Lake Basin, Oklahoma and Arkansas, 2011-13

USGS Publications Warehouse

Buck, Stephanie D.

2014-01-01

The Poteau Valley Improvement Authority uses Wister Lake in southeastern Oklahoma as a public water supply. Total phosphorus, total nitrogen, and suspended sediments from agricultural runoff and discharges from wastewater treatment plants and other sources have degraded water quality in the lake. As lake-water quality has degraded, water-treatment cost, chemical usage, and sludge production have increased for the Poteau Valley Improvement Authority. The U.S. Geological Survey (USGS), in cooperation with the Poteau Valley Improvement Authority, investigated and summarized concentrations of total phosphorus, total nitrogen, suspended sediment, and bacteria (Escherichia coli and Enterococcus sp.) in surface water flowing to Wister Lake. Estimates of total phosphorus, total nitrogen, and suspended sediment loads, yields, and flow-weighted mean concentrations of total phosphorus and total nitrogen concentrations were made for the Wister Lake Basin for a 3-year period from October 2010 through September 2013. Data from water samples collected at fixed time increments during base-flow conditions and during runoff conditions at the Poteau River at Loving, Okla. (USGS station 07247015), the Poteau River near Heavener, Okla. (USGS station 07247350), and the Fourche Maline near Leflore, Okla. (USGS station 07247650), water-quality stations were used to evaluate water quality over the range of streamflows in the basin. These data also were collected to estimate annual constituent loads and yields by using regression models. At the Poteau River stations, total phosphorus, total nitrogen, and suspended sediment concentrations in surface-water samples were significantly larger in samples collected during runoff conditions than in samples collected during base-flow conditions. At the Fourche Maline station, in contrast, concentrations of these constituents in water samples collected during runoff conditions were not significantly larger than concentrations during base-flow conditions. Flow-weighted mean total phosphorus concentrations at all three stations from 2011 to 2013 were several times larger than the Oklahoma State Standard for Scenic Rivers (0.037 milligrams per liter [mg/L]), with the largest flow-weighted phosphorus concentrations typically being measured at the Poteau River at Loving, Okla., station. Flow-weighted mean total nitrogen concentrations did not vary substantially between the Poteau River stations and the Fourche Maline near Leflore, Okla., station. At all of the sampled water-quality stations, bacteria (Escherichia coli and Enterococcus sp.) concentrations were substantially larger in water samples collected during runoff conditions than in water samples collected during base-flow conditions from 2011 to 2013. Estimated annual loads of total phosphorus, total nitrogen, and suspended sediment in the Poteau River stations during runoff conditions ranged from 82 to 98 percent of the total annual loads of those constituents. Estimated annual loads of total phosphorus, total nitrogen, and suspended sediment in the Fourche Maline during runoff conditions ranged from 86 to nearly 100 percent of the total annual loads. Estimated seasonal total phosphorus loads generally were smallest during base-flow and runoff conditions in autumn. Estimated seasonal total phosphorus loads during base-flow conditions tended to be largest in winter and during runoff conditions tended to be largest in the spring. Estimated seasonal total nitrogen loads tended to be smallest in autumn during base-flow and runoff conditions and largest in winter during runoff conditions. Estimated seasonal suspended sediment loads tended to be smallest during base-flow conditions in the summer and smallest during runoff conditions in the autumn. The largest estimated seasonal suspended sediment loads during runoff conditions typically were in the spring. The estimated mean annual total phosphorus yield was largest at the Poteau River at Loving, Okla., water-quality station. The estimated mean annual total phosphorus yield was largest during base flow at the Poteau River at Loving, Okla., water-quality station and at both of the Poteau River water-quality stations during runoff conditions. The estimated mean annual total nitrogen yields were largest at the Poteau River water-quality stations. Estimated mean annual total nitrogen yields were largest during base-flow and runoff conditions at the Poteau River at Loving, Okla., water-quality station. The estimated mean annual suspended sediment yield was largest at the Poteau River near Heavener, Okla., water-quality station during base-flow and runoff conditions. Flow-weighted mean concentrations indicated that total phosphorus inputs from the Poteau River Basin in the Wister Lake Basin were larger than from the Fourche Maline Basin. Flow-weighted mean concentrations of total nitrogen did not vary spatially in a consistent manner. The Poteau River and the Fourche Maline contributed estimated annual total phosphorus loads of 137 to 278 tons per year (tons/yr) to Wister Lake. Between 89 and 95 percent of the annual total phosphorus loads were transported to Wister Lake during runoff conditions. The Poteau River and the Fourche Maline contributed estimated annual total nitrogen loads of 657 to 1,294 tons/yr, with 86 to 94 percent of the annual total nitrogen loads being transported to Wister Lake during runoff conditions. The Poteau River and the Fourche Maline contributed estimated annual total suspended sediment loads of 110,919 to 234,637 tons/yr, with 94 to 99 percent of the annual suspended sediment loads being transported to Wister Lake during runoff conditions. Most of the total phosphorus and suspended sediment were delivered to Wister Lake during runoff conditions in the spring. The majority of the total nitrogen was delivered to Wister Lake during runoff conditions in winter.

Can the global carbon budget be balanced?

USGS Publications Warehouse

Markewich, Helaine W.; Bliss, Norman B.; Stallard, Robert F.; Sundquist, Eric T.

1997-01-01

The Mississippi Basin Carbon Project of the U.S. Geological Survey (USGS) is an effort to examine interactions between the global carbon cycle and human-induced changes to the land surface, such as farming and urbanization. Investigations in the Mississippi River basin will provide the data needed for calculating the global significance of land-use changes on land-based carbon cycling. These data are essential for predicting and mitigating the effects of global environmental change.The Mississippi Basin Carbon Project is focused on the third largest river system in the world. The Mississippi River and its tributaries drain more than 40% of the conterminous United States. The basin includes areas that typify vast regions of the Earth's surface that have undergone human development.

Quantification of Shallow Groundwater Nutrient Dynamics in Septic Areas

Treesearch

Ying Ouyang; Jia-En Zhang

2012-01-01

Of all groundwater pollution sources, septic systems are the second largest source of groundwater nitrate contamination in USA. This study investigated shallow groundwater (SGW) nutrient dynamics in septic areas at the northern part of the Lower St. Johns River Basin, Florida, USA. Thirty-five SGW-monitoring wells, located at nine different urban areas served by septic...

Simulation of dissolved nutrient export from the Dongjiang river basin with a grid-based NEWS model

NASA Astrophysics Data System (ADS)

Rong, Qiangqiang; Su, Meirong; Yang, Zhifeng; Cai, Yanpeng; Yue, Wencong; Dang, Zhi

2018-06-01

In this research, a grid-based NEWS model was proposed through coupling the geographic information system (GIS) with the Global NEWS model framework. The model was then applied to the Dongjiang River basin to simulate the dissolved nutrient export from this area. The model results showed that the total amounts of the dissolved nitrogen and phosphorus exported from the Dongjiang River basin were approximately 27154.87 and 1389.33 t, respectively. 90 % of the two loads were inorganic forms (i.e. dissolved inorganic nitrogen and phosphorus, DIN and DIP). Also, the nutrient export loads did not evenly distributed in the basin. The main stream watershed of the Dongjiang River basin has the largest DIN and DIP export loads, while the largest dissolved organic nitrogen and phosphorus (DON and DOP) loads were observed in the middle and upper stream watersheds of the basin, respectively. As for the nutrient exported from each subbasin, different sources had different influences on the output of each nutrient form. For the DIN load in each subbasin, fertilization application, atmospheric deposition and biological fixation were the three main contributors, while eluviation was the most important source for DON. In terms of DIP load, fertilizer application and breeding wastewater were the main contributors, while eluviation and fertilizer application were the two main sources for DOP.

Canoeing the Murray River (Australia) as Environmental Education: A Tale of Two Rivers

ERIC Educational Resources Information Center

Stewart, Alistair

2004-01-01

The Murray River, lying at the heart of Australia's largest catchment, is used extensively in outdoor education programs in south-eastern Australia. Since European settlement the river's ecological health has declined considerably due to activities such as damming for irrigation and clearing of native vegetation. Colonial notions of how the river…

ASUD2- decision support system on Dnieper reservoirs operations taking into account environmental priorities

NASA Astrophysics Data System (ADS)

Iritz, L.; Zheleznyak, M.; Dvorzhak, A.; Nesterov, A.; Zaslavsky, A.

2003-04-01

On the European continent the Dnieper is the third largest river basin (509000 sq.km). The Ukrainian part of the drainage basin is 291 400 sq.km. The cascade of 6 reservoirs, that have capacity from 2.5 to 18 cub.km comprises the entire reach of Dnieper River in Ukraine, redistributes the water regime in time. As a result, 17-18 cub. km water can be used, 50% for hydropower production, 30% for agriculture and up to 18% for municipal water supply. The water stress, the pollution load, the insufficient technical conditions require a lot of effort in the water management development. In order to achieve optimal use of water recourses in the Dnieper River basin, it is essential to develop strategies both for the long-term perspective (planning) as well as for the short-term perspective (operation). The Dnieper River basin must be seen as complex of the natural water resources, as well as the human system (water use, social and economic intercourse). In the frame of the project, supported by the Swedish International Development Cooperation Agency (SIDA) the software tool ASUD2 is developed to support reservoir operations provided by the State Committee of Ukraine on Water Management and by the Joint River Commission. ASUD2 includes multicriteria optimization engine that drives the reservoir water balamce models and box models of water quality. A system of supplementary (off-line) tools support more detailed analyses of the water quality parameters of largest reservoirs (Kachovka and Kremechug). The models AQUATOX and WASP ( in the developed 3-D version) are used for these purposes. The Integrated Database IDB-ASUD2 supplies the information such as state of the all reservoirs, hydrological observations and predictions, water demands, measured water quality parameters. ASUD2 is able to give the following information on an operational basis. : - recommended dynamics of the water elevation during the water allocation planning period in all reservoirs calculated on the basis of the different optimisation criteria minimum of the distance to the trajectory of the water level given by decision of the Joint River Commission, minimum value of the water contamination parameters (DO, nutrients, phosphorus), maximum energy production, taking into account limitations from fishery, water intakes of irrigation and transport channels etc; -water releases from the reservoirs to maintain the recommended dynamics in the whole Dnieper Cascade; -integrated water quality parameters for all reservoirs and distributed water quality parameters for the two largest reservoirs (Kremenchug and Kachovka). The analyses based on economical criteria provides the cost-benefit evaluation for different reservoir management alternatives. The assessment takes into account energy production, industry, agriculture as well as the costs associated with ecological damages.

Embryotoxicity and genotoxicity evaluation of sediments from Yangtze River estuary using zebrafish (Danio rerio) embryos.

PubMed

Li, Qian; Chen, Ling; Liu, Li; Wu, Lingling

2016-03-01

Sediments function both as a sink and a source of pollutants in aquatic ecosystems and may impose serious effects on benthic organisms and human health. As one of the largest estuaries in the world, the Yangtze River estuary suffers from abundant wastewater from the coastal cities. In this study, the zebrafish (Danio rerio) embryos were employed in the fish embryo test and a comet assay to evaluate the embryotoxicity and genotoxicity of the sediments from the Yangtze River estuary, respectively. Results showed that the sediments from the Yangtze River estuary significantly increased mortality, induced development abnormalities, and reduced hatching rate and heart rate of zebrafish embryos after 96 h of exposure. Significant genotoxicity was observed in the samples relative to the controls. Relatively low-level embryotoxicity and genotoxicity of sediments were found in the Yangtze River compared with other river systems. Toxic responses were also discussed in relation to the analyzed organic contaminants in sediments. More attention should be paid to non-priority pollutant monitoring in the Yangtze River estuary.

Dissolved Organic Carbon in the Yukon, Tanana and Porcupine Rivers, Alaska

NASA Astrophysics Data System (ADS)

Aiken, G. R.; Striegl, R. G.; Wickland, K. P.; Dornblaser, M. M.; Raymond, P. A.

2006-12-01

The spatial and temporal variability of dissolved organic carbon (DOC) in the Yukon River (YR) and two major tributaries, the Porcupine River (PR), a black water river draining a watershed almost entirely underlain by permafrost, and the Tanana River (TR), a glacial dominated river, are being studied to better define processes controlling DOC in these systems. Five-year seasonal averages indicate DOC concentrations follow the discharge hydrograph, with highest daily and seasonal flux occurring during spring in YR and PR and during summer-autumn in TR. Largest DOC concentrations and specific UV absorption (SUVA) values, a measure of aromatic carbon content of the DOC and an indicator of DOC source, occurred at all locations during spring snowmelt. Lowest DOC concentration and SUVA occurred during low-flow in winter due to greatly reduced contributions of soil organic matter and to relatively greater influences of ground water. While all sites had comparable DOC concentration during winter, DOC concentration was greatest at PR during spring and summer-autumn, whereas TR had the lowest average DOC and SUVA values. Within the YR, average DOC concentration and SUVA values in spring and summer-autumn increase downriver due to contributions from organic carbon rich tributaries, such as PR, that increase in number and significance as the river flows through Alaska. Most the DOC in each system was comprised of hydrophobic organic acids (HPOA) derived from terrestrial vegetation. During winter, the hydrophilic fraction, determined to be the most biodegradable, was a larger percentage of the DOC than during spring-autumn. During spring, HPOA concentration and SUVA increased significantly at all sites, suggesting that most DOC in spring is derived from terrestrial organic matter that was frozen on the land surface over winter. During spring-autumn, PR had the largest concentration of HPOA and TR had the least. Like DOC concentration, HPOA concentration and SUVA increased down river. 14C-DOC values correspond to radiocarbon ages of modern (PR), 282 (TR), and 328 (YR) yrs B.P, indicating the presence of some aged DOC in YR and TR. Comparison of the chemical character of DOC from sites along the YR suggests that most DOC is transported from its source to the Bering Sea with little within river chemical or biological alteration, a result supported by laboratory biodegradation experiments.

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.

Sedimentary Facies and Stratigraphy of the Changjiang (Yangtze River) Delta

NASA Astrophysics Data System (ADS)

Dalrymple, R. W.; Zhang, X.; Lin, C. M.

2017-12-01

A disproportionate number of the world's largest deltas are tide-dominated or strongly tide-influenced, in part because the low gradient of these rivers allows the tide to penetrate far inland, generating strong tidal currents at the river mouth. These deltas also tend to be mud-dominated because a significant fraction of the bedload is trapped farther inland. Despite their great importance as sediment depo-centers, as analogues for ancient sedimentary successions, and as areas of intense human occupation, they are the most poorly understood coastal system. The Changjiang (Yangtze River), the 4th largest river in the world in terms of sediment discharge, is one such tide-dominated system, with a mean tidal range of 2.7 m and tidal-current speeds of 1 m/s at its mouth. It shows a fairly typical series of low-relief channels and bars in the mouth-bar area and passes seaward and down-drift into a coastal mud belt that extends 800 km to the south of the river mouth. The deposits from both the transgressive-phase and modern delta are all dominated by mud, except for the fluvial-channel deposits that are clean sand. Channel-floor deposits in areas with appreciable tidal influence contain abundant fluid-mud layers (1-3 cm thick), intercalated with relatively coarse sand; such mud layers show evidence of tidal cyclicity. The overlying tidal-bar deposits commonly become sandier upward because of the upward loss of fluid-mud layers. The tidal channels and bars that characterize the mouth-bar and delta-front area are dominated by randomly organized structureless mud layers, 5-30 cm thick, that are interpreted to be storm-generated fluid-mud deposits. These mud layers become less abundant upward, generating upward-sanding successions. These facies are very similar to those seen in the Amazon and Fly River deltas, suggesting that this is a common motif, and indicating the importance of fluid mud in the dynamics of such systems. Facies proximality can be determined by careful comparison of sand-size trends, tidal mud-layer thicknesses (relative to the turbidity maximum) and the abundance of wave-generated fluid-mud layers. Application of these concepts shows that the transgressive phase of the delta consists of three retrogradationally stacked parasequences, each 7-15 m thick, overlain by the 40 m-thick highstand delta.

Preparing for uncertainty: toward managing fluvial geomorphic assessment of Massachusetts rivers

NASA Astrophysics Data System (ADS)

Hatch, C. E.; Mabee, S. B.; Slovin, N. B.; Vogel, E.

2014-12-01

Climate scientists predict (and have already observed) that in the Northeastern U.S., individual storms may be more intense, and that there will be more precipitation on an annual basis. In steep post-glacial terrain, erosion caused by floodwaters is the largest destructive force during high-intensity storm events, and the force most likely to drive major morphological changes to riverbanks and channels. What remains uncertain is which watersheds or river reaches may be subjected to increased damage from more intense storms. This presents a challenge for scientific outreach and management. Many New England states have developed systems for delineating the potentially geomorphically active zones adjacent to rivers, and Vermont has an excellent assessment and land use management system informed by process-based fluvial geomorphologic science. To date, however, Massachusetts has neither. In this project we survey existing protocols for accurately predicting locations of fluvial erosion hazard, including using LiDAR and DEM models to extract basic morphologic metrics. Particularly in states or landscapes with high river density, and during a time of tight fiscal constraints, managers need automated methods that require a minimum of expert input. We test these methods in the Deerfield river watershed in Massachusetts and Vermont, and integrate our knowledge with that of the basin's agricultural and floodplain stakeholders. The results will inform development of a comprehensive river assessment and land use management system for the state of Massachusetts.

Use of Iqqm For Management of A Regulated River System

NASA Astrophysics Data System (ADS)

Hameed, T.; Podger, G.; Harrold, T. I.

The Integrated Quantity-Quality Model (IQQM) is a modelling tool for the planning and management of water-sharing issues within regulated and unregulated river sys- tems. IQQM represents the major river system processes, including inflows, rainfall and evaporation, infiltration, and flow routing down river channels and floodplains. It is a water balance model that operates on a daily timestep and can represent reser- voirs, wetlands, surface water/groundwater interaction, and soil moisture deficit for irrigation areas, along with many other features of both natural and regulated systems. IQQM can be customised for any river valley, and has proven to be a useful tool for the development, evaluation, and selection of operational rules for complex river systems. The Lachlan catchment lies within Australia's largest river system, the Murray- Darling Basin. Extensive development in the Murray-Darling Basin within the last 100 years has resulted in land degradation, increased salinity, poor water quality, damage to wetlands, and decline in native fish species. In response to these issues, in 1995 the Murray-Darling Basin Commission (MDBC) imposed restrictions on growth in diver- sions (the "MDBC Cap"), and the New South Wales government has more recently applied its own restrictions (the "River Flow Objectives"). To implement the MDBC Cap and the River Flow Objectives, new operational rules were required. This presen- tation describes how IQQM was used to develop and evaluate these rules for the Lach- lan system. In particular, rules for release of environmental flows were developed and evaluated. The model helped identify the flow window that would be most beneficial to the riverine environment, the critical time of year when environmental releases should be made, and resource constraint conditions when environmental releases should not be made. This process also involved intensive consultations with stakeholders. The role of IQQM within this process was to help the stakeholders understand the inter- action of various users within the valley, and the impacts of the operational rules on them.

Spatiotemporal characteristics of organic contaminant concentrations and ecological risk assessment in the Songhua River, China

EPA Science Inventory

To control source pollution and improve water quality, an understanding of the spatiotemporal characteristics of organic contaminant concentrations in affected receiving waters is necessary. The Songhua River in northeast China is the country's third-largest domestic river and lo...

Interior Least Tern (Sternula antillarum) breeding distribution and ecology: implications for population-level studies and the evaluation of alternative management strategies on large, regulated rivers

PubMed Central

Lott, Casey A; Wiley, Robert L; Fischer, Richard A; Hartfield, Paul D; Scott, J Michael

2013-01-01

Interior Least Terns (Sternula antillarum) (ILT) are colonial, fish-eating birds that breed within active channels of large sand bed rivers of the Great Plains and in the Lower Mississippi Valley. Multipurpose dams, irrigation structures, and engineered navigation systems have been present on these rivers for many decades. Despite severe alteration of channels and flow regimes, regulation era floods have remained effective at maintaining bare sandbar nesting habitat on many river segments and ILT populations have been stable or expanding since they were listed as endangered in 1985. We used ILT breeding colony locations from 2002 to 2012 and dispersal information to identify 16 populations and 48 subpopulations. More than 90% of ILT and >83% of river km with suitable nesting habitat occur within the two largest populations. However, replicate populations remain throughout the entire historical, geophysical, and ecological range of ILT. Rapid colonization of anthropogenic habitats in areas that were not historically occupied suggests metapopulation dynamics. The highest likelihood of demographic connectivity among ILT populations occurs across the Southern Plains and the Lower Mississippi River, which may be demographically connected with Least Tern populations on the Gulf Coast. Paired ecological and bird population models are needed to test whether previously articulated threats limit ILT population growth and to determine if management intervention is necessary and where. Given current knowledge, the largest sources of model uncertainty will be: (1) uncertainty in relationships between high flow events and subsequent sandbar characteristics and (2) uncertainty regarding the frequency of dispersal among population subunits. We recommend research strategies to reduce these uncertainties. PMID:24223295

Water Quality in the Blue River Basin, Kansas City Metropolitan Area, Missouri and Kansas, July 1998 to October 2004

USGS Publications Warehouse

Wilkison, Donald H.; Armstrong, Daniel J.; Norman, Richard D.; Polton, Barry C.; Furlong, Edward T.; Zaugg, Steven D.

2006-01-01

Water-quality data were collected from sites in the Blue River Basin from July 1998 to October. Sites upstream from wastewater-treatment plants or the combined sewer system area had lower concentrations of total nitrogen, phosphorus, organic wastewater compounds, and pharmaceuticals, and more diverse aquatic communities. Sites downstream from wastewater-treatment plants had the largest concentrations and loads of nutrients, organic wastewater compounds, and pharmaceuticals. Approximately 60 percent of the total nitrogen and phosphorus in Blue River originated from the Indian Creek, smaller amounts from the upper Blue River (from 28 to 16 percent), and less than 5 percent from Brush Creek. Nutrient yields from the Indian Creek and the middle Blue River were significantly greater than yields from the upper Blue River, lower Brush Creek, the outside control site, and other U.S. urban sites. Large concentrations of nutrients led to eutrophication of impounded Brush Creek reaches. Bottom sediment samples collected from impoundments generally had concentrations of organic wastewater and pharmaceutical compounds equivalent to or greater than, concentrations observed in streambed sediments downstream from wastewater-treatment plants. Bacteria in streams largely was the result of nonpoint-source contributions during storms. Based on genetic source-tracking, average contributions of in-stream Esherichia coli bacteria in the basin from dogs ranged from 26-32 percent of the total concentration, and human sources ranged from 28-42 percent. Macro invertebrate diversity was highest at sites with the largest percentage of upstream land use devoted to forests and grasslands. Declines in macro invertebrate community metrics were correlated strongly with increases in several, inter-related urbanization factors.

Water quality in the Blue River basin, Kansas City metropolitan area, Missouri and Kansas, July 1998 to October 2004

USGS Publications Warehouse

Wilkison, Donald H.; Armstrong, Daniel J.; Norman, Richard D.; Poulton, Barry C.; Furlong, Edward T.; Zaugg, Steven D.

2006-01-01

Water-quality data were collected from sites in the Blue River Basin from July 1998 to October. Sites upstream from wastewater-treatment plants or the combined sewer system area had lower concentrations of total nitrogen, phosphorus, organic wastewater compounds, and pharmaceuticals, and more diverse aquatic communities. Sites downstream from wastewater-treatment plants had the largest concentrations and loads of nutrients, organic wastewater compounds, and pharmaceuticals. Approximately 60 percent of the total nitrogen and phosphorus in Blue River originated from the Indian Creek, smaller amounts from the upper Blue River (from 28 to 16 percent), and less than 5 percent from Brush Creek. Nutrient yields from the Indian Creek and the middle Blue River were significantly greater than yields from the upper Blue River, lower Brush Creek, the outside control site, and other U.S. urban sites. Large concentrations of nutrients led to eutrophication of impounded Brush Creek reaches. Bottom sediment samples collected from impoundments generally had concentrations of organic wastewater and pharmaceutical compounds equivalent to or greater than, concentrations observed in streambed sediments downstream from wastewater-treatment plants. Bacteria in streams largely was the result of nonpoint-source contributions during storms. Based on genetic source-tracking, average contributions of in-stream Esherichia coli bacteria in the basin from dogs ranged from 26-32 percent of the total concentration, and human sources ranged from 28-42 percent. Macro invertebrate diversity was highest at sites with the largest percentage of upstream land use devoted to forests and grasslands. Declines in macro invertebrate community metrics were correlated strongly with increases in several, inter-related urbanization factors.

WRF model for precipitation simulation and its application in real-time flood forecasting in the Jinshajiang River Basin, China

NASA Astrophysics Data System (ADS)

Zhou, Jianzhong; Zhang, Hairong; Zhang, Jianyun; Zeng, Xiaofan; Ye, Lei; Liu, Yi; Tayyab, Muhammad; Chen, Yufan

2017-07-01

An accurate flood forecasting with long lead time can be of great value for flood prevention and utilization. This paper develops a one-way coupled hydro-meteorological modeling system consisting of the mesoscale numerical weather model Weather Research and Forecasting (WRF) model and the Chinese Xinanjiang hydrological model to extend flood forecasting lead time in the Jinshajiang River Basin, which is the largest hydropower base in China. Focusing on four typical precipitation events includes: first, the combinations and mode structures of parameterization schemes of WRF suitable for simulating precipitation in the Jinshajiang River Basin were investigated. Then, the Xinanjiang model was established after calibration and validation to make up the hydro-meteorological system. It was found that the selection of the cloud microphysics scheme and boundary layer scheme has a great impact on precipitation simulation, and only a proper combination of the two schemes could yield accurate simulation effects in the Jinshajiang River Basin and the hydro-meteorological system can provide instructive flood forecasts with long lead time. On the whole, the one-way coupled hydro-meteorological model could be used for precipitation simulation and flood prediction in the Jinshajiang River Basin because of its relatively high precision and long lead time.

The silicon isotopic composition of fine-grained river sediments and its relation to climate and lithology

NASA Astrophysics Data System (ADS)

Bayon, G.; Delvigne, C.; Ponzevera, E.; Borges, A. V.; Darchambeau, F.; De Deckker, P.; Lambert, T.; Monin, L.; Toucanne, S.; André, L.

2018-05-01

The δ30Si stable isotopic composition of silicon in soils and fine-grained sediments can provide insights into weathering processes on continents, with important implications on the Si budget of modern and past oceans. To further constrain the factors controlling the distribution of Si isotopes in sediments, we have analysed a large number (n = 50) of separate size-fractions of sediments and suspended particulate materials collected near the mouth of rivers worldwide. This includes some of the world's largest rivers (e.g. Amazon, Congo, Mackenzie, Mississippi, Murray-Darling, Nile, Yangtze) and rivers from the case study areas of the Congo River Basin and Northern Ireland. Silt-size fractions exhibit a mean Si isotopic composition (δ30Si = -0.21 ± 0.19‰; 2 s.d.) similar to that previously inferred for the upper continental crust. In contrast, clay-size fractions display a much larger range of δ30Si values from -0.11‰ to -2.16‰, which yield a global δ30Siclay of -0.57 ± 0.60‰ (2 s.d.) representative of the mean composition of the average weathered continental crust. Overall, these new data show that the Si isotopic signature transported by river clays is controlled by the degree of chemical weathering, as inferred from strong relationships with Al/Si ratios. At a global scale, the clay-bound Si isotopic composition of the world's largest river systems demonstrates a link with climate, defining a general correlation with mean annual temperature (MAT) in corresponding drainage basins. While the distribution of Si isotopes in river sediments also appears to be influenced by the tectonic setting, lithological effects and sediment recycling from former sedimentary cycles, our results pave the way for their use as paleo-weathering and paleo-climate proxies in the sedimentary record.

LONGITUDINAL AND LATERAL PATTERNS IN PHYSICAL AND CHEMICAL ATTRIBUTES OF WILLAMETTE RIVERINE HABITAT

EPA Science Inventory

The Willamette River in western Oregon is the tenth largest river in the conterminous U. S. Plans are being developed to restore ecological function to the main corridor of the river. Our riverine research has developed a basic understanding of some of the ecological functions ...

Mississippi River delta plain, Louisiana coast, and inner shelf Holocene geologic framework, processes, and resources

USGS Publications Warehouse

Williams, S. Jeffress; Kulp, Mark; Penland, Shea; Kindinger, Jack L.; Flocks, James G.; Buster, Noreen A.; Holmes, Charles W.

2009-01-01

Extending nearly 400 km from Sabine Pass on the Texas-Louisiana border east to the Chandeleur Islands, the Louisiana coastal zone (Fig. 11.1) along the north-central Gulf of Mexico is the southern terminus of the largest drainage basin in North America (>3.3 million km2), which includes the Mississippi River delta plain where approximately 6.2 million kilograms per year of sediment is delivered to the Gulf of Mexico (Coleman 1988). The Mississippi River, active since at least Late Jurassic time (Mann and Thomas 1968), is the main distributary channel of this drainage system and during the Holocene has constructed one of the largest delta plains in the world, larger than 30,000 km2 (Coleman and Prior 1980; Coleman 1981; Coleman et al. 1998). The subsurface geology and geomorphology of the Louisiana coastal zone reffects a complex history of regional tectonic events and fluvial, deltaic, and marine sedimentary processes affected by large sea-level fluctuations. Despite the complex geology of the north-central Gulf basin, a long history of engineering studies and Scientific research investigations (see table 11.1) has led to substantial knowledge of the geologic framework and evolution of the delta plain region (see also Bird et al., chapter 1 in this volume). Mississippi River delta plain, Louisiana coast, and inner shelf Holocene geologic framework, processes, and resources. Available from: https://www.researchgate.net/publication/262802561_Mississippi_River_delta_plain_Louisiana_coast_and_inner_shelf_Holocene_geologic_framework_processes_and_resources [accessed Sep 13, 2017].

Hydromorphological assessment and catchment characterisation in the headwaters of the Volga River

NASA Astrophysics Data System (ADS)

Marquez, Fabian; Kuzovlev, Vyacheslav. V.; Schletterer, Martin

2017-04-01

Keywords: hydromorphological assessment, lowland river, reference conditions. The Volga River and its watershed represent the largest river system in Europe. The river is considered as the Russian lifeline, and various anthropogenic activities influenced the river. Nevertheless, its headwaters remained in least disturbed conditions. We present an assessment as well as an evaluation of hydromorphological conditions in the headwaters of the Volga River regarding (1) channel, (2) banks/riparian zone and (3) floodplain. The assessment follows European standards (CEN 2004) and also includes the Habitat Quality Survey (HQA). Historical flows from five gauging stations along the studied reach were analysed to determine the hydrological characteristics. The highest flows are observed during March and April, followed by summer low flows, higher flows during October and November and low flows again during winter. A decreasing tendency of the mean annual discharge is noted throughout the observation time as it accentuates in the downstream direction when comparing the stations. Based on the specific discharge (volume of water per unit time per unit area) from these gauging stations , a flow reconstruction for the Tudovka River was carried out. These analyses contribute to the REFCOND_VOLGA project, a long-term ecological monitoring programme in the headwaters of the Volga River. The research area is characterised by large forests and low population densities, thus the results provide data about reference or least impacted sites. Due to the hydromorphological characteristics the headwaters of the Volga River, i.e. the free-flowing section between the Upper Volga Lakes and Tver represents an intact lowland river and comprises a refugial system for potamalic flora and fauna.

Resilience scales of a dammed tropical river

NASA Astrophysics Data System (ADS)

Calamita, Elisa; Schmid, Martin; Wehrli, Bernhard

2017-04-01

Artificial river impoundments disrupt the seasonality and dynamics of thermal, chemical, morphological and ecological regimes in river systems. These alterations affect the aquatic ecosystems in space and time and specifically modify the seasonality and the longitudinal gradients of important biogeochemical processes. Resilience of river systems to anthropogenic stressors enables their recovery along the flow path; however little is known about the longitudinal distance that rivers need to partially restore their physical, chemical and biological integrity. In this study, the concept of a "resilience scale" will be explored for different water quality parameters downstream of Kariba dam, the largest artificial lake in the Zambezi basin (South-East Africa). The goal of this project is to develop a modelling framework to investigate and quantify the impact of large dams on downstream water quality in tropical context. In particular, we aim to assess the degree of reversibility of the main downstream alterations (temperature, oxygen, nutrients) and consequently the quantification of their longitudinal extent. Coupling in-situ measurements with hydraulic and hydrological parameters such as travel times, will allow us to define a physically-based parametrization of the different resilience scales for tropical rivers. The results will be used for improving future dam management at the local scale and assessing the ecological impact of planned dams at the catchment scale.

Extent and Depth to Top of Basalt and Interbed Hydrogeologic Units, Yakima River Basin Aquifer System, Washington

USGS Publications Warehouse

Jones, M.A.; Vaccaro, J.J.

2008-01-01

The hydrogeologic framework was delineated for the ground-water flow system of the three basalt formations and two interbeds in the Yakima River Basin, Washington. The basalt units are nearly equivalent to the Saddle Mountains, Wanapum, and Grande Ronde. The two major interbed units between the basalt formations generally are referred to as the Mabton and Vantage. The basalt formations are a productive source of ground-water for the Yakima River Basin. The Grande Ronde unit comprises the largest area in the Yakima River Basin aquifer system. This unit encompasses an area of about 5,390 mi2 and ranges in altitude from 6,900 ft, where it is exposed at land surface, to a depth of 2,800 ft below land surface. The Wanapum unit encompasses an area of 3,450 mi2 and ranges in altitude from 5,680 ft, where exposed at land surface, to a depth of 2,050 ft below land surface. The Saddle Mountains unit, the least extensive, encompasses an area of 2,290 mi2 and ranges from 4,290 ft, where exposed at the surface, to a depth of 1,840 ft below land surface.

Reconsidering residency: Characterization and conservation implications of complex migratory patterns of shortnose sturgeon (Acispenser brevirostrum)

USGS Publications Warehouse

Dionne, Phillip E.; Zydlewski, Gayle B.; Kinnison, Michael T.; Zydlewski, Joseph D.; Wippelhauser, Gail S.

2013-01-01

Efforts to conserve endangered species usually involve attempts to define and manage threats at the appropriate scale of population processes. In some species that scale is localized; in others, dispersal and migration link demic units within larger metapopulations. Current conservation strategies for endangered shortnose sturgeon (Acipenser brevirostrum) assume the species is river resident, with little to no movement between rivers. However we have found that shortnose sturgeon travel more than 130 km through coastal waters between the largest rivers in Maine. Indeed, acoustic telemetry shows that shortnose sturgeon enter six out of the seven acoustically monitored rivers we have monitored, with over 70% of tagged individuals undertaking coastal migrations between river systems. Four migration patterns were identified for shortnose sturgeon inhabiting the Penobscot River, Maine: river resident (28%), spring coastal emigrant (24%), fall coastal emigrant (33%), and summer coastal emigrant (15%). No shortnose sturgeon classified as maturing female exhibited a resident pattern, indicating differential migration. Traditional river-specific assessment and management of shortnose sturgeon could be better characterized using a broader metapopulation scale, at least in the Gulf of Maine, that accounts for diverse migratory strategies and the importance of migratory corridors as critical habitat.

Assessment of metallic mineral resources in the Humboldt River Basin, Northern Nevada, with a section on Platinum-Group-Element (PGE) Potential of the Humboldt Mafic Complex

USGS Publications Warehouse

Wallace, Alan R.; Ludington, Steve; Mihalasky, Mark J.; Peters, Stephen G.; Theodore, Ted G.; Ponce, David A.; John, David A.; and Berger, Byron R.; Zientek, Michael L.; Sidder, Gary B.; Zierenberg, Robert A.

2004-01-01

The Humboldt River Basin is an arid to semiarid, internally drained basin that covers approximately 43,000 km2 in northern Nevada. The basin contains a wide variety of metallic and nonmetallic mineral deposits and occurrences, and, at various times, the area has been one of the Nation's leading or important producers of gold, silver, copper, mercury, and tungsten. Nevada currently (2003) is the third largest producer of gold in the world and the largest producer of silver in the United States. Current exploration for additional mineral deposits focuses on many areas in northern Nevada, including the Humboldt River Basin.

Hydrologic Conditions that Influence Streamflow Losses in a Karst Region of the Upper Peace River, Polk County, Florida

USGS Publications Warehouse

Metz, P.A.; Lewelling, B.R.

2009-01-01

The upper Peace River from Bartow to Fort Meade, Florida, is described as a groundwater recharge area, reflecting a reversal from historical groundwater discharge patterns that existed prior to the 1950s. The upper Peace River channel and floodplain are characterized by extensive karst development, with numerous fractures, crevasses, and sinks that have been eroded in the near-surface and underlying carbonate bedrock. With the reversal in groundwater head gradients, river water is lost to the underlying groundwater system through these karst features. An investigation was conducted to evaluate the hydrologic conditions that influence streamflow losses in the karst region of the upper Peace River. The upper Peace River is located in a basin that has been altered substantially by phosphate mining and increases in groundwater use. These alterations have changed groundwater flow patterns and caused streamflow declines through time. Hydrologic factors that have had the greatest influence on streamflow declines in the upper Peace River include the lowering of the potentiometric surfaces of the intermediate aquifer system and Upper Floridan aquifer beneath the riverbed elevation due to below-average rainfall (droughts), increases in groundwater use, and the presence of numerous karst features in the low-water channel and floodplain that enhance the loss of streamflow. Seepage runs conducted along the upper Peace River, from Bartow to Fort Meade, indicate that the greatest streamflow losses occurred along an approximate 2-mile section of the river beginning about 1 mile south of the Peace River at Bartow gaging station. Along the low-water and floodplain channel of this 2-mile section, there are about 10 prominent karst features that influence streamflow losses. Losses from the individual karst features ranged from 0.22 to 16 cubic feet per second based on measurements made between 2002 and 2007. The largest measured flow loss for all the karst features was about 50 cubic feet per second, or about 32 million gallons per day, on June 28, 2002. Streamflow losses varied throughout the year, and were related to seasonal fluctuations in groundwater levels. When groundwater levels were at their lowest level at the end of the dry season (May and June), there was an increased potential for streamflow losses. During this study, the largest streamflow losses occurred at the beginning of the summer rainy season when discharge in the river increased and large volumes of water were needed to replenish unfilled cavities and void spaces in the underlying aquifers. The underlying geology along the upper Peace River and floodplain is highly karstified, and aids in the movement and amount of streamflow that is lost to the groundwater system in this region. Numerous karst features and fractured carbonates and cavernous zones observed in geologic cores and geophysical logs indicate an active, well-connected, groundwater flow system. Aquifer and dye tests conducted along the upper Peace River indicate the presence of cavernous and highly transmissive layers within the floodplain area that can store and transport large volumes of water in underground cavities. A discharge measurement made during this study indicates that the cavernous system associated with Dover Sink can accept over 10 million gallons per day (16 cubic feet per second) of streamflow before the localized aquifer storage volume is replenished and the level of the sink is stabilized.

Quaternary Morphodynamics of Fluvial Dispersal Systems Revealed: The Fly River, PNG, and the Sunda Shelf, SE Asia, simulated with the Massively Parallel GPU-based Model 'GULLEM'

NASA Astrophysics Data System (ADS)

Aalto, R. E.; Lauer, J. W.; Darby, S. E.; Best, J.; Dietrich, W. E.

2015-12-01

During glacial-marine transgressions vast volumes of sediment are deposited due to the infilling of lowland fluvial systems and shallow shelves, material that is removed during ensuing regressions. Modelling these processes would illuminate system morphodynamics, fluxes, and 'complexity' in response to base level change, yet such problems are computationally formidable. Environmental systems are characterized by strong interconnectivity, yet traditional supercomputers have slow inter-node communication -- whereas rapidly advancing Graphics Processing Unit (GPU) technology offers vastly higher (>100x) bandwidths. GULLEM (GpU-accelerated Lowland Landscape Evolution Model) employs massively parallel code to simulate coupled fluvial-landscape evolution for complex lowland river systems over large temporal and spatial scales. GULLEM models the accommodation space carved/infilled by representing a range of geomorphic processes, including: river & tributary incision within a multi-directional flow regime, non-linear diffusion, glacial-isostatic flexure, hydraulic geometry, tectonic deformation, sediment production, transport & deposition, and full 3D tracking of all resulting stratigraphy. Model results concur with the Holocene dynamics of the Fly River, PNG -- as documented with dated cores, sonar imaging of floodbasin stratigraphy, and the observations of topographic remnants from LGM conditions. Other supporting research was conducted along the Mekong River, the largest fluvial system of the Sunda Shelf. These and other field data provide tantalizing empirical glimpses into the lowland landscapes of large rivers during glacial-interglacial transitions, observations that can be explored with this powerful numerical model. GULLEM affords estimates for the timing and flux budgets within the Fly and Sunda Systems, illustrating complex internal system responses to the external forcing of sea level and climate. Furthermore, GULLEM can be applied to most ANY fluvial system to explore processes across a wide range of temporal and spatial scales. The presentation will provide insights (& many animations) illustrating river morphodynamics & resulting landscapes formed as a result of sea level oscillations. [Image: The incised 3.2e6 km^2 Sundaland domain @ 431ka

Flood of May 23, 2004, in the Turkey and Maquoketa River basins, northeast Iowa

USGS Publications Warehouse

Eash, David A.

2006-01-01

Severe flooding occurred on May 23, 2004, in the Turkey River Basin in Clayton County and in the Maquoketa River Basin in Delaware County following intense thunderstorms over northeast Iowa. Rain gages at Postville and Waucoma, Iowa, recorded 72-hour rainfall of 6.32 and 6.55 inches, respectively, on May 23. Unofficial rainfall totals of 8 to 10 inches were reported in the Turkey River Basin. The peak discharge on May 23 at the Turkey River at Garber streamflow-gaging station was 66,700 cubic feet per second (recurrence interval greater than 500 years) and is the largest flood on record in the Turkey River Basin. The timing of flood crests on the Turkey and Volga Rivers, and local tributaries, coincided to produce a record flood on the lower part of the Turkey River. Three large floods have occurred at the Turkey River at Garber gaging station in a 13-year period. Peak discharges of the floods of June 1991 and May 1999 were 49,900 cubic feet per second (recurrence interval about 150 years) and 53,900 cubic feet per second (recurrence interval about 220 years), respectively. The peak discharge on May 23 at the Maquoketa River at Manchester gaging station was 26,000 cubic feet per second (recurrence interval about 100 years) and is the largest known flood in the upper part of the Maquoketa River Basin.

Simulations of hydrologic response in the Apalachicola-Chattahoochee-Flint River Basin, Southeastern United States

USGS Publications Warehouse

LaFontaine, Jacob H.; Jones, L. Elliott; Painter, Jaime A.

2017-12-29

A suite of hydrologic models has been developed for the Apalachicola-Chattahoochee-Flint River Basin (ACFB) as part of the National Water Census, a U.S. Geological Survey research program that focuses on developing new water accounting tools and assessing water availability and use at the regional and national scales. Seven hydrologic models were developed using the Precipitation-Runoff Modeling System (PRMS), a deterministic, distributed-parameter, process-based system that simulates the effects of precipitation, temperature, land cover, and water use on basin hydrology. A coarse-resolution PRMS model was developed for the entire ACFB, and six fine-resolution PRMS models were developed for six subbasins of the ACFB. The coarse-resolution model was loosely coupled with a groundwater model to better assess the effects of water use on streamflow in the lower ACFB, a complex geologic setting with karst features. The PRMS coarse-resolution model was used to provide inputs of recharge to the groundwater model, which in turn provide simulations of groundwater flow that were aggregated with PRMS-based simulations of surface runoff and shallow-subsurface flow. Simulations without the effects of water use were developed for each model for at least the calendar years 1982–2012 with longer periods for the Potato Creek subbasin (1942–2012) and the Spring Creek subbasin (1952–2012). Water-use-affected flows were simulated for 2008–12. Water budget simulations showed heterogeneous distributions of precipitation, actual evapotranspiration, recharge, runoff, and storage change across the ACFB. Streamflow volume differences between no-water-use and water-use simulations were largest along the main stem of the Apalachicola and Chattahoochee River Basins, with streamflow percentage differences largest in the upper Chattahoochee and Flint River Basins and Spring Creek in the lower Flint River Basin. Water-use information at a shorter time step and a fully coupled simulation in the lower ACFB may further improve water availability estimates and hydrologic simulations in the basin.

Decreasing flood risk perception in Porto Alegre - Brazil and its influence on water resource management decisions

NASA Astrophysics Data System (ADS)

Allasia, D. G.; Tassi, R.; Bemfica, D.; Goldenfum, J. A.

2015-06-01

Porto Alegre is the capital and largest city in the Brazilian state of Rio Grande do Sul in Southern Brazil with approximately 1.5 million inhabitants. The city lies on the eastern bank of the Guaiba Lake, formed by the convergence of five rivers and leading to the Lagoa dos Patos, a giant freshwater lagoon navigable by even the largest of ships. This river junction has become an important alluvial port as well as a chief industrial and commercial centre. However, this strategic location resulted in severe damage because of its exposure to flooding from the river system, affecting the city in the years 1873, 1928, 1936, 1941 and 1967. In order to reduce flood risk, a complex system of levees and pump stations was implemented during 1960s and 1970s. Since its construction, not a single large flood event occurred. However, in recent years, the levees in the downtown region of Porto Alegre were severally criticized by city planners and population. Several projects have been proposed to demolish the Mauá Wall due to the false perception of lack of flood risk. Similar opinions and reactions against flood infrastructure have been observed in other cities in Brazil, such as Itajaí and Blumenau, with disastrous consequences. This paper illustrates how the perception of flood risk in Porto Alegre has changed over recent years as a result of flood infrastructure, and how such changes in perceptions can influence water management decisions.

A snapshot on prokaryotic diversity of the Solimões River basin (Amazon, Brazil).

PubMed

Toyama, D; Santos-Júnior, C D; Kishi, L T; Oliveira, T C S; Garcia, J W; Sarmento, H; Miranda, F P; Henrique-Silva, F

2017-05-18

The Amazon region has the largest hydrographic basin on the planet and 
is well known for its huge biodiversity of plants and animals. However, 
there is a lack of studies on aquatic microbial biodiversity in the 
Solimões River, one of its main water courses. To investigate the 
microbial biodiversity of this region, we performed 16S rRNA gene clone 
libraries from Solimões River and adjacent rivers and lakes. Our question was which microorganisms inhabit the different types of aquatic 
environments in this part of the basin, and how diversity varies among 
these environments (rivers and lakes). The microbial 
diversity generating 13 clone libraries of the bacterial 16S rRNA gene 
and 5 libraries of the archaeal 16S rRNA gene was assessed. Diversity measured by several alpha diversity indices (ACE, Chao, Shannon and Simpson) revealed significant differences in diversity indices between lake and river samples. The site with higher microbial diversity was in the Solimões River (4S), downstream the confluence with Purus River. The most common bacterial taxon was the cosmopolitan Polynucleobacter genus, widely observed in all samples. The phylum Thaumarchaeota was the prevailing archaeal taxon. Our results provide the first insight into the microbial diversity of the world's largest river basin.

Characteristics of movement and factors affecting the choice of mode of transport of community on the bank of Musi River of Palembang City of South Sumatra

NASA Astrophysics Data System (ADS)

Arliansyah, Joni; Hartono, Yusuf; Hastuti, Yulia; Astuti, Rinna

2017-11-01

Palembang City is one of the cities having the largest river in Indonesia and it should be able to take advantage of river transportation as an alternative choice. Inadequate availability of river transport facilities and infrastructures makes the people prefer other modes of land transportation rather than using river transportation. In addition, the development planning of river transportation such as the development of river taxi is less successful because it is not yet based on the movement pattern of the origin of the community travel destination. Based on the above matter, this study was conducted. The aim of the study was to find out the characteristics and factors affecting the mode choice of the community living along the bank of Musi River of Palembang City to be the basis of the development of river transportation system in Palembang City. The selected modes were motorcycles, cars, city transports, and ketek (motorized boats). Survey of home interviews was conducted to determine the origin of the destination and characteristics of travel was conducted in 30 villages located on the banks of Musi River. Field survey was conducted to determine the conditions and types of existing river transportation facilities and services. The results show that only 5.3 % of the occurrence movement used river transportation, the rest used motorcycles (69.1%), urban transport (15.9 %) and cars (9.7%), with the travel range less than10 minutes and 10 - 20 minutes as much as 43.2 % and 29 % of the total trips. From the socioeconomic profile of the community, it is found that most of the people living along the Musi River have low and middle incomes with the largest types of jobs as workers, students, shop owner, and housewives. The peak movement time for the movement of river transport occurs at 7:00 - 8:00, 10:00 - 11:00 and 16:00 - 17:00 with the movement of origin of the destination of river transportation is known to be 50% at the traditional market center of Dermaga of 16 Ilir. Types of river transportation used for short trips are large, medium and small motorized boats. While for longer trips there are large and medium size speedboats. The statistical analysis results showed that the parameters affecting the mode choice of the community living along the bank of Musi River were age, occupation, monthly income, house types, and travel time.

Nonnative Fishes in the Upper Mississippi River System

USGS Publications Warehouse

Irons, Kevin S.; DeLain, Steven A.; Gittinger, Eric; Ickes, Brian S.; Kolar, Cindy S.; Ostendort, David; Ratcliff, Eric N.; Benson, Amy J.; Irons, Kevin S.

2009-01-01

The introduction, spread, and establishment of nonnative species is widely regarded as a leading threat to aquatic biodiversity and consequently is ranked among the most serious environmental problems facing the United States today. This report presents information on nonnative fish species observed by the Long Term Resource Monitoring Program on the Upper Mississippi River System a nexus of North American freshwater fish diversity for the Nation. The Long Term Resource Monitoring Program, as part of the U.S. Army Corps of Engineers' Environmental Management Plan, is the Nation's largest river monitoring program and stands as the primary source of standardized ecological information on the Upper Mississippi River System. The Long Term Resource Monitoring Program has been monitoring fish communities in six study areas on the Upper Mississippi River System since 1989. During this period, more than 3.5 million individual fish, consisting of 139 species, have been collected. Although fish monitoring activities of the Long Term Resource Monitoring Program focus principally on entire fish communities, data collected by the Program are useful for detecting and monitoring the establishment and spread of nonnative fish species within the Upper Mississippi River System Basin. Sixteen taxa of nonnative fishes, or hybrids thereof, have been observed by the Long Term Resource Monitoring Program since 1989, and several species are presently expanding their distribution and increasing in abundance. For example, in one of the six study areas monitored by the Long Term Resource Monitoring Program, the number of established nonnative species has increased from two to eight species in less than 10 years. Furthermore, contributions of those eight species can account for up to 60 percent of the total annual catch and greater than 80 percent of the observed biomass. These observations are critical because the Upper Mississippi River System stands as a nationally significant pathway for nonnative species expansion between the Mississippi River and the Great Lakes Basin. This report presents a synthesis of data on nonnative fish species observed during Long Term Resource Monitoring Program monitoring activities.

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.

A tree-ring based reconstruction of Logan River streamflow, northern Utah

Treesearch

Eric B. Allen; Tammy M. Rittenour; R. Justin DeRose; Matthew F. Bekker; Roger Kjelgren; Brendan M. Buckley

2013-01-01

We created six new tree-ring chronologies in northern Utah, which were used with preexisting chronologies from Utah and western Wyoming to reconstruct mean annual flow for the Logan River, the largest tributary of the regionally important Bear River. Two reconstruction models were developed, a ''Local'' model that incorporated two Rocky Mountain...

Sinkhole formation and hydrogeological situation at the salt mining area of Solotvyno, Ukraine

NASA Astrophysics Data System (ADS)

Stoeckl, L.; Banks, V.

2017-12-01

In Solotvyno, Ukraine, several salt mines were unexpectedly flooded in the recent past. As a result, dozens of sinkholes formed and are still forming with diameters up to 250 m. A one month advisory mission by the European Commission was launched in fall 2016 to conduct a risk assessment. The former mining area is situated in close vicinity to the river Theiss, which is the largest contributory of the largest river in Europe: the Danube. As river contamination by the release of large quantities of saltwater would lead to an international disaster, hydrogeological measurements were taken on-site to study the system. Saturated (hyper-saline) water as well as fresh surface and groundwater were encountered in different locations of the former mining area. Water samples were analyzed for chemistry and stable isotopes at BGR revealing insight into groundwater flow dynamics. Satellite imaging and interferometric synthetic aperture radar (SAR) were applied to study ground movements and evaluate the risk of further collapses. A resulting conceptual model explains the processes of sinkhole formation as well as the natural restoration of the salt dome prior to mining operations. This study shows the advantage of an interdisciplinary approach to conduct a risk assessment in the case of large mine collapses.

Hotspots within the Transboundary Selenga River Basin

NASA Astrophysics Data System (ADS)

Kasimov, Nikolay; Lychagin, Mikhail; Chalov, Sergey

2013-04-01

Gathering the efficient information on water pollution of transboundary river systems remains the crucial task in international water management, environmental pollution control and prevention health problems. Countries, located in the low parts of the river basins, depend on the water strategy and water use in the adjacent countries, located upstream. Surface water pollution is considered to be the most serious problem, facing the above-mentioned countries. Large efforts in terms of field measurement campaigns and (numerical) transport modeling are then typically needed for relevant pollution prediction and prevention. Russian rivers take inflow from 8 neighboring countries. Among them there are 2 developing economies - People Republic of China and Mongolia, which are located in water-scarce areas and thus solve their water-related problems through the consumption of international water. Negative change of water runoff and water quality in the foreign part of transboundary river is appeared inside Russian territory with more or less delay. The transboundary river system of Selenga is particularly challenging, being the biggest tributary of Lake Baikal which is the largest freshwater reservoir in the world. Selenga River contributes about 50 % of the total inflow into Baikal. It originates in the mountainous part of Mongolia and then drains into Russia. There are numerous industries and agricultural activities within the Selenga drainage basin that affect the water quality of the river system. Absence of the single monitoring system and predictive tools for pollutants transport in river system requires large efforts in understanding sources of water pollution and implemented data on the relevant numerical systems for the pollution prediction and prevention. Special investigations in the Selenga river basin (Mongolia and Russia) were done to assess hot spots and understand state-of-the art in sediment load, water chemistry and hydrobiology of transboundary systems. Hot spot assessment included 100 gauge stations in the river basin with discharge measurement by ADCP, turbidity (T) and suspended sediment concentration (SSC), bed load by bed load traps, composition of salt, biochemical oxidation, nitrogen and phosphorous content in water, pH, redox and conductivity values, and also content of heavy metals in water, suspended matter and sediments. The study revealed rather high levels of dissolved Fe, Al, Mn, Zn, Cu, and Mo in the Selenga River water which often are higher than MPC for water fishery. Most contrast distribution is characteristic for W and Mo, which is caused by mineral deposits in the Selenga basin. The most severe pollution of aquatic systems in the basin caused by mining activities is characteristic for a small river Modonkul, which flows into Dzhida River (left tributary of Selenga).

Sources and loads of nutrients in the South Platte River, Colorado and Nebraska, 1994-95

USGS Publications Warehouse

Litke, D.W.

1996-01-01

The South Platte River Basin was one of 20 river basins selected in 1991 for investigation as part of the U.S. Geological Survey's National Water- Quality Assessment (NAWQA) Program. Nationwide, nutrients have been identified as one of the primary nationwide water-quality concerns and are of particular interest in the South Platte River Basin where nutrient concentrations are large compared to concentrations in other NAWQA river basins. This report presents estimates of the magnitude of nutrient-source inputs to the South Platte River Basin, describes nutrient concen- trations and loads in the South Platte River during different seasons, and presents comparisons of nutrient inputs to instream nutrient loads. Annual nutrient inputs to the basin were estimated to be 306,000 tons of nitrogen and 41,000 tons of phosphorus. The principal nutrient sources were wastewater-treatment plants, fertilizer and manure applications, and atmospheric deposition. To characterize nutrient concentrations and loads in the South Platte River during different seasons, five nutrient synoptic samplings were conducted during 1994 and 1995. Upstream from Denver, Colorado, during April 1994 and January 1995, total nitrogen concentrations were less than 2 milligrams per liter (mg/L), and total phosphorus concentrations were less than 0.2 mg/L. The water in the river at this point was derived mostly from forested land in the mountains west of Denver. Total nutrient concentrations increased through the Denver metropolitan area, and concentration peaks occurred just downstream from each of Denver's largest wastewater-treatment plants with maximum concentrations of 13.6 mg/L total nitrogen and 2.4 mg/L total phosphorus. Nutrient concen- concentrations generally decreased downstream from Denver. Upstream from Denver during April 1994 and January 1995, total nitrogen loads were less than 1,000 pounds per day (lb/d), and total phosphorus loads were less than 125 lb/d. Total nutrient loads increased through the Denver metropolitan area, and load peaks occurred just downstream from each of Denver's largest wastewater-treatment plants, with a maximum load of 14,000 lb/d total nitrogen and 2,300 lb/d total phosphorus. In April 1994, nutrient loads generally decreased from Henderson, Colorado, to North Platte, Nebraska. In January 1995, however, nutrient loads increased from Henderson to Kersey, Colorado (maximum loads of 31,000 lb/d total nitrogen and 3,000 lb/d total phosphorus), and then decreased from Kersey to North Platte. Seasonal nutrient loads primarily were dependent on streamflow. Total nitrogen loads were largest in June 1994 and January 1995 when streamflows also were largest. During June, streamflow was large, but nitrogen concentrations were small, which indicated that snowmelt runoff diluted the available supply of nitrogen. Total phosphorus loads were largest in June, when streamflow and phosphorus concentrations were large, which indicated an additional source of phosphorus during snowmelt runoff. Streamflow along the South Platte River was smallest in April and August 1994, and nutrient loads also were smallest during these months. The downstream pattern for nutrient loads did not vary much by season. Loads were large at Henderson, decreased between Henderson and Kersey, and usually were largest at Kersey. The magnitude of the decrease in loads between Henderson and Kersey varied between synoptics and was dependent on the amount of water removed by irrigation ditches. Nutrient loads leaving the basin were very small compared to the estimated total nutrient inputs to the basin. Streamflow balances indicated that the South Platte River is a gaining river throughout much of its length; streamflow-balance residuals were as large as 15 cubic feet per second per mile. Nutrient-load balances indicated that increases in river nitrate loads were, in some places, due to nitrification and, elsewhere, were due to the influx of nitrate-enriched ground water to

The effect of the 2011 flood on agricultural chemical and sediment movement in the lower Mississippi River Basin

NASA Astrophysics Data System (ADS)

Welch, H.; Coupe, R.; Aulenbach, B.

2012-04-01

Extreme hydrologic events, such as floods, can overwhelm a surface water system's ability to process chemicals and can move large amounts of material downstream to larger surface water bodies. The Mississippi River is the 3rd largest River in the world behind the Amazon in South America and the Congo in Africa. The Mississippi-Atchafalaya River basin grows much of the country's corn, soybean, rice, cotton, pigs, and chickens. This is large-scale modern day agriculture with large inputs of nutrients to increase yields and large applied amounts of crop protection chemicals, such as pesticides. The basin drains approximately 41% of the conterminous United States and is the largest contributor of nutrients to the Gulf of Mexico each spring. The amount of water and nutrients discharged from the Mississippi River has been related to the size of the low dissolved oxygen area that forms off of the coast of Louisiana and Texas each summer. From March through April 2011, the upper Mississippi River basin received more than five times more precipitation than normal, which combined with snow melt from the Missouri River basin, created a historic flood event that lasted from April through July. The U.S. Geological Survey, as part of the National Stream Quality Accounting Network (NASQAN), collected samples from six sites located in the lower Mississippi-Atchafalaya River basin, as well as, samples from the three flow-diversion structures or floodways: the Birds Point-New Madrid in Missouri and the Morganza and Bonnet Carré in Louisiana, from April through July. Samples were analyzed for nutrients, pesticides, suspended sediments, and particle size; results were used to determine the water quality of the river during the 2011 flood. Monthly loads for nitrate, phosphorus, pesticides (atrazine, glyphosate, fluometuron, and metolachlor), and sediment were calculated to quantify the movement of agricultural chemicals and sediment into the Gulf of Mexico. Nutrient loads were compared to historic loads to assess the effect of the flood on the zone of hypoxia that formed in the Gulf of Mexico during the spring of 2011.

Assessment of contaminant levels and trophic relations at a World Heritage Site by measurements in a characteristic shorebird species

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

Schwemmer, Philipp, E-mail: schwemmer@ftz-west.uni-kiel.de; Covaci, Adrian, E-mail: adrian.covaci@uantwerpen.be; Das, Krishna, E-mail: krishna.das@ulg.ac.be

2015-01-15

The River Elbe is responsible for influxes of contaminants into the Wadden Sea World Heritage Site. We investigated levels of polychlorinated biphenyls (PCBs), oxychlordane (OxC), hexachlorobenzene (HCB), hexachlorocyclohexanes (α-, β-, γ-HCHs), dichlorodiphenyltrichloroethane (DDT) and its metabolites, and polybrominated diphenyl ethers (PBDEs) in blood and feathers from Eurasian oystercatchers (Haematopus ostralegus; n=28) at the Elbe and compared it with a non-riverine site about 90 km further north. (1) Mean levels of all contaminants in feathers and serum were significantly higher at the river (∑PCBs: 27.6 ng/g feather, 37.0 ng/ml serum; ∑DDTs: 5.3 ng/g feather, 4.4 ng/ml serum) compared with the non-riverinemore » site (∑PCBs: 6.5 ng/g feather, 1.2 ng/ml serum; ∑DDTs: 1.4 ng/g feather, 0.5 ng/ml serum). Mean ∑HCH and HCB levels were <1.8 ng/g in feather and <1.8 ng/ml in serum at both sites. (2) Levels of most detectable compounds in serum and feathers were significantly related, but levels were not consistently higher in either tissue. (3) There was no significant relationship between trophic level in individual oystercatchers (expressed as δ15N) or the degree of terrestrial feeding (expressed as δ13C) and contaminant loads. (4) PBDEs were not detected in significant amounts at either site. The results of this study indicate that the outflow from one of Europe′s largest river systems is associated with significant historical contamination, reflected by the accumulation of contaminants in body tissues in a coastal benthivore predator. - Highlights: • Contaminants in Oystercatchers from the Elbe river and a non-riverine site were measured. • Mean levels of contaminants were higher at the river than at the non-riverine site. • Levels of most contaminants in serum and feathers were significantly related. • No relationship between trophic level (δ15N) and contaminant level was found. • One of Europe′s largest river systems is associated with major historical contamination.« less

Mississippi River

Atmospheric Science Data Center

2014-05-15

... is approximately 2348 miles long. Over the course of it's history, the mighty river has flooded many times. The largest flood recorded in ... Wisconsin has receded. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission ...

Impacts of reforestation upon sediment load and water outflow in the Lower Yazoo River Watershed, Mississippi

Treesearch

Ying Ouyang; Theodor D. Leininger; Matt Moran

2013-01-01

Among the world’s largest coastal and river basins, the Lower Mississippi River Alluvial Valley (LMRAV)is one of the most disturbed by human activities. This study ascertained the impacts of reforestation on water outflow attenuation (i.e., water flow out of the watershed outlet) and sediment load reduction in the Lower Yazoo River Watershed (LYRW) within the LMRAV...

Channel-conveyance capacity, channel change, and sediment transport in the lower Puyallup, White, and Carbon Rivers, western Washington

USGS Publications Warehouse

Czuba, Jonathan A.; Czuba, Christiana R.; Magirl, Chistopher S.; Voss, Frank D.

2010-01-01

Draining the volcanic, glaciated terrain of Mount Rainier, Washington, the Puyallup, White, and Carbon Rivers convey copious volumes of water and sediment down to Commencement Bay in Puget Sound. Recent flooding in the lowland river system has renewed interest in understanding sediment transport and its effects on flow conveyance throughout the lower drainage basin. Bathymetric and topographic data for 156 cross sections were surveyed in the lower Puyallup River system by the U.S. Geological Survey (USGS) and were compared with similar datasets collected in 1984. Regions of significant aggradation were measured along the Puyallup and White Rivers. Between 1984 and 2009, aggradation totals as measured by changes in average channel elevation were as much as 7.5, 6.5, and 2 feet on the Puyallup, White, and Carbon Rivers, respectively. These aggrading river sections correlated with decreasing slopes in riverbeds where the rivers exit relatively confined sections in the upper drainage and enter the relatively unconstricted valleys of the low-gradient Puget Lowland. Measured grain-size distributions from each riverbed showed a progressive fining downstream. Analysis of stage-discharge relations at streamflow-gaging stations along rivers draining Mount Rainier demonstrated the dynamic nature of channel morphology on river courses influenced by glaciated, volcanic terrain. The greatest rates of aggradation since the 1980s were in the Nisqually River near National (5.0 inches per year) and the White River near Auburn (1.8 inches per year). Less pronounced aggradation was measured on the Puyallup River and the White River just downstream of Mud Mountain Dam. The largest measured rate of incision was measured in the Cowlitz River at Packwood (5.0 inches per year). Channel-conveyance capacity estimated using a one-dimensional hydraulic model decreased in some river reaches since 1984. The reach exhibiting the largest decrease (about 20-50 percent) in channel-conveyance capacity was the White River between R Street Bridge and the Lake Tapps return, a reach affected by recent flooding. Conveyance capacity also decreased in sections of the Puyallup River. Conveyance capacity was mostly unchanged along other study reaches. Bedload transport was simulated throughout the entire river network and consistent with other observations and analyses, the hydraulic model showed that the upper Puyallup and White Rivers tended to accumulate sediment. Accuracy of the bedload-transport modeling, however, was limited due to a scarcity of sediment-transport data sets from the Puyallup system, mantling of sand over cobbles in the lower Puyallup and White Rivers, and overall uncertainty in modeling sediment transport in gravel-bedded rivers. Consequently, the output results from the model were treated as more qualitative in value, useful in comparing geomorphic trends within different river reaches, but not accurate in producing precise predictions of mass of sediment moved or deposited. The hydraulic model and the bedload-transport component were useful for analyzing proposed river-management options, if surveyed cross sections adequately represented the river-management site and proposed management options. The hydraulic model showed that setback levees would provide greater flood protection than gravel-bar scalping after the initial project construction and for some time thereafter, although the model was not accurate enough to quantify the length of time of the flood protection. The greatest hydraulic benefit from setback levees would be a substantial increase in the effective channel-conveyance area. By widening the distance between levees, the new floodplain would accommodate larger increases in discharge with relatively small incremental increases in stage. Model simulation results indicate that the hydraulic benefit from a setback levee also would be long-lived and would effectively compensate for increased deposition within the setback reach

The quality of our Nation's waters: water quality in the Mississippi embayment-Texas coastal uplands aquifer system and Mississippi River Valley alluvial aquifer, south-central United States, 1994-2008

USGS Publications Warehouse

Kingsbury, James A.; Barlow, Jeannie R.; Katz, Brian G.; Welch, Heather L.; Tollett, Roland W.; Fahlquist, Lynne S.

2015-01-01

About 8 million people rely on groundwater from the Mississippi embayment—Texas coastal uplands aquifer system for drinking water. The Mississippi River Valley alluvial aquifer also provides drinking water for domestic use in rural areas but is of primary importance to the region as a source of water for irrigation. Irrigation withdrawals from this aquifer are among the largest in the Nation and play a key role in the economy of the area, where annual crop sales total more than $7 billion. The reliance of the region on both aquifers for drinking water and irrigation highlights the importance of long-term management to sustain the availability and quality of these resources.

Changes in fish assemblage structure in the main-stem Willamette River, Oregon

EPA Science Inventory

The Willamette River if Oregon’s largest river, with a basin area of 29,800 km² and a mean annual discharge of 680 m³/3. Beginning in the 1890s, the channel was greatly simplified for navigation. By the 1940s, it was polluted by organic wastes, which resulted in low dissolved o...

Threatened fishes of the world: Alosa alabamae (Jordan and Evermann, 1896) (Clupeidae)

Treesearch

Dwayne W. Meadows; Susan B. Adams; Jacob F. Schaefer

2007-01-01

River drainage to the Suwannee River, Florida (Mettee and O'Neil 2003); extirpated from at least 8 of the 14 native states (Mettee and O'Neil 2003). Abundance: Once commercially harvested, now rare (Mettee and O'Neil 2003); largest remaining population occurs in the Apalachicola River, Florida (Barku-100 et a!. 1993). Habitat...

Fluvial geomorphic elements in modern sedimentary basins and their potential preservation in the rock record: A review

NASA Astrophysics Data System (ADS)

Weissmann, G. S.; Hartley, A. J.; Scuderi, L. A.; Nichols, G. J.; Owen, A.; Wright, S.; Felicia, A. L.; Holland, F.; Anaya, F. M. L.

2015-12-01

Since tectonic subsidence in sedimentary basins provides the potential for long-term facies preservation into the sedimentary record, analysis of geomorphic elements in modern continental sedimentary basins is required to understand facies relationships in sedimentary rocks. We use a database of over 700 modern sedimentary basins to characterize the fluvial geomorphology of sedimentary basins. Geomorphic elements were delineated in 10 representative sedimentary basins, focusing primarily on fluvial environments. Elements identified include distributive fluvial systems (DFS), tributive fluvial systems that occur between large DFS or in an axial position in the basin, lacustrine/playa, and eolian environments. The DFS elements include large DFS (> 30 km in length), small DFS (< 30 km in length), coalesced DFS in bajada or piedmont plains, and incised DFS. Our results indicate that over 88% of fluvial deposits in the evaluated sedimentary basins are present as DFS, with tributary systems covering a small portion (1-12%) of the basin. These geomorphic elements are commonly arranged hierarchically, with the largest transverse rivers forming large DFS and smaller transverse streams depositing smaller DFS in the areas between the larger DFS. These smaller streams commonly converge between the large DFS, forming a tributary system. Ultimately, most transverse rivers become tributary to the axial system in the sedimentary basin, with the axial system being confined between transverse DFS entering the basin from opposite sides of the basin, or a transverse DFS and the edge of the sedimentary basin. If axial systems are not confined by transverse DFS, they will form a DFS. Many of the world's largest rivers are located in the axial position of some sedimentary basins. Assuming uniformitarianism, sedimentary basins from the past most likely had a similar configuration of geomorphic elements. Facies distributions in tributary positions and those on DFS appear to display specific morphologic patterns. Tributary rivers tend to increase in size in the downstream direction. Because axial tributary rivers are present in confined settings in the sedimentary basin, they migrate back and forth within a relatively narrow belt (relative to the overall size of the sedimentary basin). Thus, axial tributary rivers tend to display amalgamated channel belt form with minimal preservation potential of floodplain deposits. Chute and neck cutoff avulsions are also common on meandering rivers in these settings. Where rivers on DFS exit their confining valley on the basin margin, sediment transport capacity is reduced and sediment deposition occurs resulting in development of a 'valley exit' nodal avulsion point that defines the DFS apex. Rivers may incise downstream of the basin margin valley because of changes in sediment supply and discharge through climatic variability or tectonic processes. We demonstrate that rivers on DFS commonly decrease in width down-DFS caused by infiltration, bifurcation, and evaporation. In proximal areas, channel sands are amalgamated through repeated avulsion, reoccupation of previous channel belts, and limited accumulation space. When rivers flood on the medial to distal portions of a DFS, the floodwaters spread across a large area on the DFS surface and typically do not re-enter the main channel. In these distal areas, rivers on DFS commonly avulse, leaving a discrete sand body and providing high preservation potential for floodplain deposits. Additional work is needed to evaluate the geomorphic character of modern sedimentary basins in order to construct improved facies models for the continental sedimentary rock record. Specifically, models for avulsion, bifurcation, infiltration, and geomorphic form on DFS are required to better define and subsequently predict facies geometries. Studies of fluvial systems in sedimentary basins are also important for evaluating flood patterns and groundwater distributions for populations in these regions.

Human-induced stream channel abandonment/capture and filling of floodplain channels within the Atchafalaya River Basin, Louisiana

USGS Publications Warehouse

Kroes, Daniel E.; Kraemer, Thomas F.

2013-01-01

The Atchafalaya River Basin is a distributary system of the Mississippi River containing the largest riparian area in the lower Mississippi River Valley and the largest remaining forested bottomland in North America. Reductions in the area of open water in the Atchafalaya have been occurring over the last 100 years, and many historical waterways are increasingly filled by sediment. This study examines two cases of swamp channels (3/s) that are filling and becoming unnavigable as a result of high sediment loads and slow water velocities. The water velocities in natural bayous are further reduced because of flow capture by channels constructed for access. Bathymetry, flow, suspended sediment, deposited bottom-material, isotopes, and photointerpretation were used to characterize the channel fill. On average, water flowing through these two channels lost 23% of the suspended sediment load in the studied reaches. Along one of the studied reaches, two constructed access channels diverted significant flow out of the primary channel and into the adjacent swamp. Immediately downstream of each of the two access channels, the cross-sectional area of the studied channel was reduced. Isotopic analyses of bottom-material cores indicate that bed filling has been rapid and occurred after detectable levels of Cesium-137 were no longer being deposited. Interpretation of aerial photography indicates that water is bypassing the primary channels in favor of the more hydraulically efficient access channels, resulting in low or no-velocity flow conditions in the primary channel. These swamp channel conditions are typical in the Atchafalaya River Basin where relict large channel dimensions result in flow velocities that are normally too low to carry fine-grained sediment. Constructed channels increase the rate of natural channel avulsion and abandonment as a result of flow capture.

Debris flows from tributaries of the Colorado River, Grand Canyon National Park, Arizona

USGS Publications Warehouse

Webb, R.H.; Pringle, P.T.; Rink, G.R.

1987-01-01

A reconnaissance of 36 tributaries of the Colorado River indicates that debris flows are a major process by which sediment is transported to the Colorado River in Grand Canyon National Park. Debris flows are slurries of sediment and water that have a water content < 40% by volume. Debris flows occur frequently in arid and semiarid regions. Slope failures commonly trigger debris flows, which can originate from any rock formation in the Grand Canyon. The largest and most frequent flows originate from the Permian Hermit Shale, the underlying Esplanade Sandstone of the Supai Group, and other formations of the Permian and Pennsylvanian Supai Group. Debris flows have reached the Colorado River on an average of once every 20 to 30 yr in the Lava-Chuar Creek drainage since about 1916. Two debris flows have reached the Colorado River in the last 25 yr in Monument Creek. The Crystal Creek drainage has had an average of one debris flow reaching the Colorado River every 50 yr, although the debris flow of 1966 has been the only flow that reached the Colorado River since 1900. Debris flows may actually reach the Colorado River more frequently in these drainages because evidence for all debris flows may not have been preserved in the channel-margin stratigraphy. Discharges were estimated for the peak flow of three debris flows that reached the Colorado River. The debris flow of 1966 in the Lava-Chuar Creek drainage had an estimated discharge of 4,000 cu ft/sec. The debris flow of 1984 in the Monument Creek drainage had a discharge estimated between 3,600 and 4,200 cu ft/sec. The debris flow of 1966 in the Crystal Creek drainage had a discharge estimated between 9,200 and 14,000 cu ft/sec. Debris flows in the Grand Canyon generally are composed of 10 to 40% sand by weight and may represent a significant source of beach-building sand along the Colorado River. The particle size distributions are very poorly sorted and the largest transported boulders were in the Crystal Creek drainage. Reworking of debris fans by the Colorado River creates debris bars that constrain the size of eddy systems and forms secondary rapids and riffles below tributary mouths. (See also W89-09239) (Lantz-PTT)

Subsidence Monitoring in Seville (S Spain) Using Multi-Temporal InSAR

NASA Astrophysics Data System (ADS)

Ruiz-Armenteros, Antonio M.; Ruiz-Constan, Ana; Lamas-Fernandez, Francisco; Galindo-Zaldivar, Jesus; Sousa, Joaquim J.; Sanz de Galdeano, Carlos; Delgado, Manuel J.; Pedrera-Parias, Antonio; Martos-Rosillo, Sergio; Gil, Antonio J.; Caro-Cuenca, Miguel; Hanssen, Ramon F.

2016-08-01

Seville, with a metropolitan population of about 1.5 million, is the capital and largest city of Andalusia (S Spain). It is the 30th most populous municipality in the European Union and contains three UNESCO World Heritage Sites. The Seville harbour, located about 80 km from the Atlantic Ocean, is the only river port in Spain. The city is located on the plain of the Guadalquivir River. Using Multi-Temporal InSAR with ERS-1/2 and Envisat data a subsidence behavior is detected in the period 1992-2010. The geometry of the subsiding areas suggests that it should be conditioned by the fluvial dynamics of the Guadalquivir River and its tributaries. Facies distribution along the fluvial system (paleochannels, flood plains...), with different grain size and matrix proportion, may explain the relative subsidence between the different sectors.

How have the river discharges and sediment loads changed in the Changjiang River basin downstream of the Three Gorges Dam?

NASA Astrophysics Data System (ADS)

Guo, Leicheng; Su, Ni; Zhu, Chunyan; He, Qing

2018-05-01

Streamflow and sediment loads undergo remarkable changes in worldwide rivers in response to climatic changes and human interferences. Understanding their variability and the causes is of vital importance regarding river management. With respect to the Changjiang River (CJR), one of the largest river systems on earth, we provide a comprehensive overview of its hydrological regime changes by analyzing long time series of river discharges and sediment loads data at multiple gauge stations in the basin downstream of Three Gorges Dam (TGD). We find profound river discharge reduction during flood peaks and in the wet-to-dry transition period, and slightly increased discharges in the dry season. Sediment loads have reduced progressively since 1980s owing to sediment yield reduction and dams in the upper basin, with notably accelerated reduction since the start of TGD operation in 2003. Channel degradation occurs in downstream river, leading to considerable river stage drop. Lowered river stages have caused a 'draining effect' on lakes by fostering lake outflows following TGD impoundments. The altered river-lake interplay hastens low water occurrence inside the lakes which can worsen the drought given shrinking lake sizes in long-term. Moreover, lake sedimentation has decreased since 2002 with less sediment trapped in and more sediment flushed out of the lakes. These hydrological changes have broad impacts on river flood and drought occurrences, water security, fluvial ecosystem, and delta safety.

Measuring Paleolandscape Relief in Alluvial River Systems from the Stratigraphic Record

NASA Astrophysics Data System (ADS)

Hajek, E. A.; Trampush, S. M.; Chamberlin, E.; Greenberg, E.

2017-12-01

Aggradational alluvial river systems sometimes generate relief in the vicinity of their channel belts (i.e. alluvial ridges) and it has been proposed that this process may define important thresholds in river avulsion. The compensation scale can be used to estimate the maximum relief across a landscape and can be connected to the maximum scale of autogenic organization in experimental and numerical systems. Here we use the compensation scale - measured from outcrops of Upper Cretaceous and Paleogene fluvial deposits - to estimate the maximum relief that characterized ancient fluvial landscapes. In some cases, the compensation scale significantly exceeds the maximum channel depth observed in a deposit, suggesting that aggradational alluvial systems organize to sustain more relief than might be expected by looking only in the immediate vicinity of the active channel belt. Instead, these results indicate that in some systems, positive topographic relief generated by multiple alluvial ridge complexes and/or large-scale fan features may be associated with landscape-scale autogenic organization of channel networks that spans multiple cycles of channel avulsion. We compare channel and floodplain sedimentation patterns among the studied ancient fluvial systems in an effort to determine whether avulsion style, channel migration, or floodplain conditions influenced the maximum autogenic relief of ancient landscapes. Our results emphasize that alluvial channel networks may be organized at much larger spatial and temporal scales than previously realized and provide an avenue for understanding which types of river systems are likely to exhibit the largest range of autogenic dynamics.

Source, transport and fluxes of Amazon River particulate organic carbon: Insights from river sediment depth-profiles

NASA Astrophysics Data System (ADS)

Bouchez, Julien; Galy, Valier; Hilton, Robert G.; Gaillardet, Jérôme; Moreira-Turcq, Patricia; Pérez, Marcela Andrea; France-Lanord, Christian; Maurice, Laurence

2014-05-01

In order to reveal particulate organic carbon (POC) source and mode of transport in the largest river basin on Earth, we sampled the main sediment-laden tributaries of the Amazon system (Solimões, Madeira and Amazon) during two sampling campaigns, following vertical depth-profiles. This sampling technique takes advantage of hydrodynamic sorting to access the full range of solid erosion products transported by the river. Using the Al/Si ratio of the river sediments as a proxy for grain size, we find a general increase in POC content with Al/Si, as sediments become finer. However, the sample set shows marked variability in the POC content for a given Al/Si ratio, with the Madeira River having lower POC content across the measured range in Al/Si. The POC content is not strongly related to the specific surface area (SSA) of the suspended load, and bed sediments have a much lower POC/SSA ratio. These data suggest that SSA exerts a significant, yet partial, control on POC transport in Amazon River suspended sediment. We suggest that the role of clay mineralogy, discrete POC particles and rock-derived POC warrant further attention in order to fully understand POC transport in large rivers.

Summary statistics and trend analysis of water-quality data at sites in the Gila River basin, New Mexico and Arizona

USGS Publications Warehouse

Baldys, Stanley; Ham, L.K.; Fossum, K.D.

1995-01-01

Summary statistics and temporal trends for 19 water-chemistry constituents and for turbidity were computed for 13 study sites in the Gila River basin, Arizona and New Mexico. A nonparametric technique, the seasonal Kendall tau test for flow-adjusted data, was used to analyze temporal changes in water-chemistry data. For the 19 selected constituents and turbidity, decreasing trends in concentrations outnumbered increasing trends by more than two to one. Decreasing trends in concentrations of constituents were found for 49 data sets at the 13 study sites. Gila River at Calva and Gila River above diversions, at Gillespie Dam (eight each) had the most decreasing trends for individual sites. The largest number of decreasing trends measured for a constituent was six for dissolved lead. The next largest number of decreasing trends for a constituent was for dissolved solids and total manganese (five each). Hardness, dissolved sodium, and dissolved chloride had decreasing trends at four of the study sites. Increasing trends in concen- trations of constituents were found for 24 data sets at the 13 study sites. The largest number of increasing trends measured for a single constituent was for pH (four), dissolved sulfate (three), dissolved chromium (three) and total manganese (three). Increased concentrations of constituents generally were found in three areas in the basin-at Pinal Creek above Inspiration Dam, at sites above reservoirs, and at sites on the main stem of the Gila River from Gillespie Dam to the mouth.

Nutrient sources and transport in the Missouri River Basin, with emphasis on the effects of irrigation and reservoirs

USGS Publications Warehouse

Brown, J.B.; Sprague, L.A.; Dupree, J.A.

2011-01-01

SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were used to relate instream nutrient loads to sources and factors influencing the transport of nutrients in the Missouri River Basin. Agricultural inputs from fertilizer and manure were the largest nutrient sources throughout a large part of the basin, although atmospheric and urban inputs were important sources in some areas. Sediment mobilized from stream channels was a source of phosphorus in medium and larger streams. Irrigation on agricultural land was estimated to decrease the nitrogen load reaching the Mississippi River by as much as 17%, likely as a result of increased anoxia and denitrification in the soil zone. Approximately 16% of the nitrogen load and 33% of the phosphorus load that would have otherwise reached the Mississippi River was retained in reservoirs and lakes throughout the basin. Nearly half of the total attenuation occurred in the eight largest water bodies. Unlike the other major tributary basins, nearly the entire instream nutrient load leaving the outlet of the Platte and Kansas River subbasins reached the Mississippi River. Most of the larger reservoirs and lakes in the Platte River subbasin are upstream of the major sources, whereas in the Kansas River subbasin, most of the source inputs are in the southeast part of the subbasin where characteristics of the area and proximity to the Missouri River facilitate delivery of nutrients to the Mississippi River.

Global change impacts on river ecosystems: A high-resolution watershed study of Ebro river metabolism.

PubMed

Val, Jonatan; Chinarro, David; Pino, María Rosa; Navarro, Enrique

2016-11-01

Global change is transforming freshwater ecosystems, mainly through changes in basin flow dynamics. This study assessed how the combination of climate change and human management of river flow impacts metabolism of the Ebro River (the largest river basin in Spain, 86,100km(2)), assessed as gross primary production-GPP-and ecosystem respiration-ER. In order to investigate the influence of global change on freshwater ecosystems, an analysis of trends and frequencies from 25 sampling sites of the Ebro river basin was conducted. For this purpose, we examined the effect of anthropogenic flow control on river metabolism with a Granger causality study; simultaneously, took into account the effects of climate change, a period of extraordinary drought (largest in past 140years). We identified periods of sudden flow changes resulting from both human management and global climate effects. From 1998 to 2012, the Ebro River basin was trending toward a more autotrophic condition indicated by P/R ratio. Particularly, the results show that floods that occurred after long periods of low flows had a dramatic impact on the respiration (i.e., mineralization) capacity of the river. This approach allowed for a detailed characterization of the relationships between river metabolism and drought impacts at the watershed level. These findings may allow for a better understanding of the ecological impacts provoked by flow management, thus contributing to maintain the health of freshwater communities and ecosystem services that rely on their integrity. Copyright © 2016 Elsevier B.V. All rights reserved.

Nutrient Sources and Transport in the Missouri River Basin, with Emphasis on the Effects of Irrigation and Reservoirs1

PubMed Central

Brown, Juliane B; Sprague, Lori A; Dupree, Jean A

2011-01-01

Abstract SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were used to relate instream nutrient loads to sources and factors influencing the transport of nutrients in the Missouri River Basin. Agricultural inputs from fertilizer and manure were the largest nutrient sources throughout a large part of the basin, although atmospheric and urban inputs were important sources in some areas. Sediment mobilized from stream channels was a source of phosphorus in medium and larger streams. Irrigation on agricultural land was estimated to decrease the nitrogen load reaching the Mississippi River by as much as 17%, likely as a result of increased anoxia and denitrification in the soil zone. Approximately 16% of the nitrogen load and 33% of the phosphorus load that would have otherwise reached the Mississippi River was retained in reservoirs and lakes throughout the basin. Nearly half of the total attenuation occurred in the eight largest water bodies. Unlike the other major tributary basins, nearly the entire instream nutrient load leaving the outlet of the Platte and Kansas River subbasins reached the Mississippi River. Most of the larger reservoirs and lakes in the Platte River subbasin are upstream of the major sources, whereas in the Kansas River subbasin, most of the source inputs are in the southeast part of the subbasin where characteristics of the area and proximity to the Missouri River facilitate delivery of nutrients to the Mississippi River. PMID:22457581

Large rivers of the United States

USGS Publications Warehouse

Iseri, Kathleen T.; Langbein, Walter Basil

1974-01-01

Information on the flow of the 28 largest rivers in the United States is presented for the base periods 1931-60 and 1941-70. Drainage area, stream length, source, and mouth are included. Table 1 shows the average discharge at downstream gaging stations. Table 2 lists large rivers in order of average discharge at the mouth, based on the period 1941-70.

Assessment of Heavy Metal Pollution in Sediments of Inflow Rivers to Lake Taihu, China.

PubMed

Niu, Yong; Niu, Yuan; Pang, Yong; Yu, Hui

2015-11-01

Lake Taihu, the third-largest freshwater body in China, has many functions, including drinking water supply, flood control, cultivation, navigation, and tourism. In this study, sediment samples were collected at 31 sites from 11 inflow rivers in 2012, to investigate the distribution and concentration of heavy metals copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), and chromium (Cr), and to assess their potential ecological risk. The highest mean concentration was found for Zn, followed by Cu, Cr, Pb, and Ni. Generally, heavy metal pollution was more serious in Wu Jingang River and Caoqiao River, probably because they receive large amounts of wastewater from various local industrial enterprises. The potential ecological risk values of the heavy metals were larger than 120 in more than 25.8% of the sediment samples, indicating a very high risk. The largest ecological risk was due to copper. Furthermore, the results of a principal component analysis and subsequent analysis of variance showed that heavy metal concentrations in the sediment of inflow rivers were higher than those of the lake, which created a large hazard for the aquatic ecosystems of Lake Taihu.

Hydraulic characterization of the middle reach of the Congo River

NASA Astrophysics Data System (ADS)

O'Loughlin, F.; Trigg, M.; Schumann, G.; Bates, P. D.

2012-12-01

Little is known about the hydraulics of the Congo River compared to other large rivers, such as the Amazon, Nile and Mississippi, despite it draining an area greater than 3.7 million square kilometers and being the seconded largest river in terms of discharge. While there has been some study of the Congo Basin, most of these concentrate on ecology or the human aspects, but few look at the either the hydrology or hydraulic characteristics of the river. Of the published hydrology/hydraulic research, most concentrates on the hydrology of the Congo Basin aiming to alleviate some of the issues relating to a sparse river gauging network that currently exists. Even fewer studies have looked at hydraulics of the Congo, and usually over a relatively small area of the basin. To undertake a larger study area requires more details on the characteristics of the Congo River. The Congo River can be divided into three distinct reaches; the upper, middle and lower reaches. We concentrate on the middle reach which starts upstream at Boyoma falls, just south of Kisangani, and ends downstream at Livingstone Falls, at Kinshasa (DRC), Brazzaville (Congo) and the Pool Malebo. From Kisangani to Kinshasa, the middle Congo crosses the equator twice and is join by two large tributaries (Ubangi, Kasai) and is highly braided. The middle reach of the Congo is especially important as its still largely undisturbed wetlands are the seconded largest tropical wetlands globally. It is also the main transportation link between Kisangani and Kinshasa, the two largest cities in the DRC. By utilizing remotely sensed Landsat and Icesat datasets, we present the first detailed study on the hydraulic characterization of the middle reach of the Congo River. With these datasets we identify the main control points of flow in the middle reach, investigate how the water surface slope, channel width, islands and braids vary between high and low flows and spatially along the reach. We compare the middle reach of the Congo to other large braided rivers to highlight how the Congo is unique. This detailed analysis will yield key hydraulic characteristics for large reaches of the main channel and tributaries that will be essential for correct hydraulic modeling of the river in due course, and will also provide new insights into the behavior and hydrodynamics of this mysterious river.

Turbulent forces within river plumes affect spread

NASA Astrophysics Data System (ADS)

Bhattacharya, Atreyee

2012-08-01

When rivers drain into oceans through narrow mouths, hydraulic forces squeeze the river water into buoyant plumes that are clearly visible in satellite images. Worldwide, river plumes not only disperse freshwater, sediments, and nutrients but also spread pollutants and organisms from estuaries into the open ocean. In the United States, the Columbia River—the largest river by volume draining into the Pacific Ocean from North America—generates a plume at its mouth that transports juvenile salmon and other fish into the ocean. Clearly, the behavior and spread of river plumes, such as the Columbia River plume, affect the nation's fishing industry as well as the global economy.

River salinity on a mega-delta, an unstructured grid model approach.

NASA Astrophysics Data System (ADS)

Bricheno, Lucy; Saiful Islam, Akm; Wolf, Judith

2014-05-01

With an average freshwater discharge of around 40,000 m3/s the BGM (Brahmaputra Ganges and Meghna) river system has the third largest discharge worldwide. The BGM river delta is a low-lying fertile area covering over 100,000 km2 mainly in India and Bangladesh. Approximately two-thirds of the Bangladesh people work in agriculture and these local livelihoods depend on freshwater sources directly linked to river salinity. The finite volume coastal ocean model (FVCOM) has been applied to the BGM delta in order to simulate river salinity under present and future climate conditions. Forced by a combination of regional climate model predictions, and a basin-wide river catchment model, the 3D baroclinic delta model can determine river salinity under the current climate, and make predictions for future wet and dry years. The river salinity demonstrates a strong seasonal and tidal cycle, making it important for the model to be able to capture a wide range of timescales. The unstructured mesh approach used in FVCOM is required to properly represent the delta's structure; a complex network of interconnected river channels. The model extends 250 km inland in order to capture the full extent of the tidal influence and grid resolutions of 10s of metres are required to represent narrow inland river channels. The use of FVCOM to simulate flows so far inland is a novel challenge, which also requires knowledge of the shape and cross-section of the river channels.

Ganges River Delta, Bangladesh, India

NASA Image and Video Library

1994-11-14

The Ganges River Delta is the largest inter-tidal delta in the world. With its extensive mangrove mud flats, swamp vegetation and sand dunes, it is characteristic of many tropical and subtropical coasts. As seen in this photograph, the tributaries and distributaries of the Ganges and Brahmaputra Rivers deposit huge amounts of silt and clay that create a shifting maze of waterways and islands in the Bay of Bengal.

Functional Process Zones Characterizing Aquatic Insect Communities in Streams of the Brazilian Cerrado.

PubMed

Godoy, B S; Simião-Ferreira, J; Lodi, S; Oliveira, L G

2016-04-01

Stream ecology studies see to understand ecological dynamics in lotic systems. The characterization of streams into Functional Process Zones (FPZ) has been currently debated in stream ecology because aquatic communities respond to functional processes of river segments. Therefore, we tested if different functional process zones have different number of genera and trophic structure using the aquatic insect community of Neotropical streams. We also assessed whether using physical and chemical variables may complement the approach of using FPZ to model communities of aquatic insects in Cerrado streams. This study was conducted in 101 streams or rivers from the central region of the state of Goiás, Brazil. We grouped the streams into six FPZ associated to size of the river system, presence of riparian forest, and riverbed heterogeneity. We used Bayesian models to compare number of genera and relative frequency of the feeding groups between FPZs. Streams classified in different FPZs had a different number of genera, and the largest and best preserved rivers had an average of four additional genera. Trophic structure exhibited low variability among FPZs, with little difference both in the number of genera and in abundance. Using functional process zones in Cerrado streams yielded good results for Ephemeroptera, Plecoptera, and Trichoptera communities. Thus, species distribution and community structure in the river basin account for functional processes and not necessarily for the position of the community along a longitudinal dimension of the lotic system.

Implications of river morphology response to Dien Bien Phu fault in NW Vietnam

NASA Astrophysics Data System (ADS)

Lai, K.; Chen, Y.; Lam, D.

2007-12-01

In northern Vietnam, most rivers are flowing southeastward sub- or parallel to the valley of Red River and characterized by long but narrow catchments. The Dien Bien Phu fault is associated with the most seismically active zone in Vietnam and situated in the potential eastern boundary of the rotating southeastern Tibetan block. It cuts the Da River, the largest tributary of Red River in northwest Vietnam and has distorted the drainage basin resulting in complex river patterns. To assess the river morphology response to active Dien Bien Phu fault, we use 1/50,000 topographic data and ASTER images to map the precise river courses and digital elevation model data of SRTM to retrieve and analyze the river profiles. From the mapping results, the N-S striking fault results in three conspicuous north-trending river valleys coincided with the different fault segments to facilitate the measurement and reconstruction of the offsets along the fault. Further combining the longitudinal profile analysis we obtain ca. 10 km offsets by deflected river as the largest left-lateral displacement recorded along the active fault. The restored results show the downstream paleochannel of the Da River had been abandoned and becomes two small tributaries in opposite flow directions at present due to differential crustal uplift. Also the present crisscross valley at the junction of the Da River and the fault is resulted from the capture by another river which has been also deflected by the neotectonics. Based on our observations on river response, the Dien Bien Phu fault is a sinistral dominant fault with an uplift occurring in its eastern block. Furthermore the active Dien Bien Phu fault does not cut through the Red River northward indicating the western block of the fault can not be regarded as a single rigid block. There should be possible to find NW-SE trending faults paralleling to Red River to accommodate the deformation of the western block of the fault.

Implications of river morphology response to Dien Bien Phu fault in NW Vietnam

NASA Astrophysics Data System (ADS)

Lai, K.; Chen, Y.; Lam, D.

2004-12-01

In northern Vietnam, most rivers are flowing southeastward sub- or parallel to the valley of Red River and characterized by long but narrow catchments. The Dien Bien Phu fault is associated with the most seismically active zone in Vietnam and situated in the potential eastern boundary of the rotating southeastern Tibetan block. It cuts the Da River, the largest tributary of Red River in northwest Vietnam and has distorted the drainage basin resulting in complex river patterns. To assess the river morphology response to active Dien Bien Phu fault, we use 1/50,000 topographic data and ASTER images to map the precise river courses and digital elevation model data of SRTM to retrieve and analyze the river profiles. From the mapping results, the N-S striking fault results in three conspicuous north-trending river valleys coincided with the different fault segments to facilitate the measurement and reconstruction of the offsets along the fault. Further combining the longitudinal profile analysis we obtain ca. 10 km offsets by deflected river as the largest left-lateral displacement recorded along the active fault. The restored results show the downstream paleochannel of the Da River had been abandoned and becomes two small tributaries in opposite flow directions at present due to differential crustal uplift. Also the present crisscross valley at the junction of the Da River and the fault is resulted from the capture by another river which has been also deflected by the neotectonics. Based on our observations on river response, the Dien Bien Phu fault is a sinistral dominant fault with an uplift occurring in its eastern block. Furthermore the active Dien Bien Phu fault does not cut through the Red River northward indicating the western block of the fault can not be regarded as a single rigid block. There should be possible to find NW-SE trending faults paralleling to Red River to accommodate the deformation of the western block of the fault.

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.

River turbidity and sediment loads during dam removal

USGS Publications Warehouse

Warrick, Jonathan A.; Duda, Jeffrey J.; Magirl, Christopher S.; Curran, Chris A.

2012-01-01

Dam decommissioning has become an important means for removing unsafe or obsolete dams and for restoring natural fluvial processes, including discharge regimes, sediment transport, and ecosystem connectivity [Doyle et al., 2003]. The largest dam-removal project in history began in September 2011 on the Elwha River of Washington State (Figure 1a). The project, which aims to restore the river ecosystem and increase imperiled salmon populations that once thrived there, provides a unique opportunity to better understand the implications of large-scale river restoration.

Modern Environmental Changes on Amapa Coastal Plain under Amazon River Influence

NASA Astrophysics Data System (ADS)

Santos, V. F.; Figueiredo, A. G.; Silveira, O. M.; Polidori, L.

2007-05-01

The Amazonian coastal environment is very dynamic compared to other coasts. It is situated at the edge of the Earth's largest forest, and is segmented by fluvial systems, with the biggest being the Amazon River. The rivers are particularly influenced by the Intertropical Convergence Zone (ITCZ), which controls the water and particle discharge, and the flooding regime. Moderate and strong El Nino conditions correlate with low-precipitation periods, and La Nina events cause precipitation to increase. These variables and others related to the Amazon dispersal system create an interesting area for the study of global and regional environmental changes. The Araguari River floodplain on the Amapa coast is influenced by natural processes of global scale such as ENSO events and ITCZ, and by local processes such as Amazon River discharge, tides and tidal bore (pororoca). Anthropogenic processes such as extensive water-buffalo farming also promote environmental changes. Time- series analyses of remote sensing images and suspended sediment have shown that the maximum turbidity zone inside Araguari River is related to the pororoca phenomenon. The pororoca remobilizes sediment from the river bottom and margins, developing sediment suspension >15 g/l as it passes - creating fluid muds. The pororoca also introduces Amazon- and shelf-derived sediment into the Araguari estuary. Measurements during eight spring-tide cycles indicate erosion of 3 cm of consolidated mud and deposition of 1 cm. The pororoca also influences the remobilization and cycling of nutrients and consequently affects the distribution of benthic organisms, including benthonic foraminifera and thecamoebians. For more than a century, the coastal plain has had water-buffalo farming (>42,000 animals today), which modifies the drainage system and affects sedimentary processes. Areas with more buffalo trails have higher suspended-sediment concentration (SSC) during the dry season and lower SSC during the rainy season. This relationship is reversed in drainages without the influence of the herd. The development of small channels, one meter deep by one meter wide, induced by the buffalos can evolve into a large drainage network in a short period of time. The Santana Creek started as a buffalo trail and in three decades it evolved into a network with a main channel 200 m wide and 6 km long. Despite the Amazon River having the largest influence in the region, the Araguari River also has a considerable water discharge of 2.4x103 m3/s and particulate discharge of 7x105 tons/y, and is able to impose changes to the Amapa coastal environments and inner shelf. The natural closure of the Araguari north arm during middle of the 19th century has induced the development of a wide coastal plain in the Cape Norte region, and decreased fresh water to the Carapaporis channel. On the other hand, deforestation for farm development and buffalo farming has influenced the hydrologic regime, sediment and nutrient balance.

Lithium isotopes in large rivers reveal the cannibalistic nature of modern continental weathering and erosion

NASA Astrophysics Data System (ADS)

Dellinger, Mathieu; Gaillardet, Jérôme; Bouchez, Julien; Calmels, Damien; Galy, Valier; Hilton, Robert G.; Louvat, Pascale; France-Lanord, Christian

2014-09-01

The erosion of major mountain ranges is thought to be largely cannibalistic, recycling sediments that were deposited in the ocean or on the continents prior to mountain uplift. Despite this recognition, it has not yet been possible to quantify the amount of recycled material that is presently transported by rivers to the ocean. Here, we have analyzed the Li content and isotope composition (δLi7) of suspended sediments sampled along river depth profiles and bed sands in three of the largest Earth's river systems (Amazon, Mackenzie and Ganga-Brahmaputra rivers). The δLi7 values of river-sediments transported by these rivers range from +5.3 to -3.6‰ and decrease with sediment grain size. We interpret these variations as reflecting a mixture of unweathered rock fragments (preferentially transported at depth in the coarse fraction) and present-day weathering products (preferentially transported at the surface in the finest fraction). Only the finest surface sediments contain the complementary reservoir of Li solubilized by water-rock interactions within the watersheds. Li isotopes also show that river bed sands can be interpreted as a mixture between unweathered fragments of igneous and sedimentary rocks. A mass budget approach, based on Li isotopes, Li/Al and Na/Al ratios, solved by an inverse method allows us to estimate that, for the large rivers analyzed here, the part of solid weathering products formed by present-day weathering reactions and transported to the ocean do not exceed 35%. Li isotopes also show that the sediments transported by the Amazon, Mackenzie and Ganga-Brahmaputra river systems are mostly sourced from sedimentary rocks (>60%) rather than igneous rocks. This study shows that Li isotopes in the river particulate load are a good proxy for quantifying both the erosional rock sources and the fingerprint of present-day weathering processes. Overall, Li isotopes in river sediments confirm the cannibalistic nature of erosion and weathering.

Mobility and natural attenuation of metals and arsenic in acidic waters of the drainage system of Timok River from Bor copper mines (Serbia) to Danube River.

PubMed

Đorđievski, Stefan; Ishiyama, Daizo; Ogawa, Yasumasa; Stevanović, Zoran

2018-06-22

Bor, Krivelj, and Bela Rivers belong to the watershed of Timok River, which is a tributary of transboundary Danube River. These rivers receive metal-rich acidic wastewater from metallurgical facilities and acid mine drainage (AMD) from mine wastes around Bor copper mines. The aim of this study was to determine the mobility and natural attenuation of metals and arsenic in rivers from Bor copper mines to Danube River during the year 2015. The results showed that metallurgical facilities had the largest impact on Bor River by discharging about 400 t of Cu per year through highly acidic wastewater (pH = 2.6). The highest measured concentrations of Cu in river water and sediments were 40 mg L -1 and 1.6%, respectively. Dissolution of calcite from limestone bedrock and a high concentration of bicarbonate ions in natural river water (about 250 mg L -1 ) enhanced the neutralization of acidic river water and subsequent chemical precipitation of metals and arsenic. Decreases in the concentrations of Al, Fe, Cu, As, and Pb in river water were mainly due to precipitation on the river bed. On the other hand, dilution played an important role in the decreases in concentrations of Mn, Ni, Zn, and Cd. Chemically precipitated materials and flotation tailings containing Fe-rich minerals (fayalite, magnetite, and pyrite) were transported toward Danube River during the periods of high discharge. This study showed that processes of natural attenuation in catchments with limestone bedrock play an important role in reducing concentrations of metals and arsenic in AMD-bearing river water.

A Real Options Method for Estimating the Adoption Potential of Forestry and Agroforestry Systems on Private Lands in the Lower Mississippi Alluvial Valley, USA

Treesearch

Gregory E. Frey; D. Evan Mercer; Frederick W. Cubbage; Robert C. Abt

2010-01-01

The Lower Mississippi River Alluvial Valley (LMAV), once was the largest forested bottom-land area in the continental United States, but has undergone widespread loss of forest through conversion to farmland. Restoration of forest functions and values has been a key conservation goal in the LMAV since the 1970s. This study utilizes a partial differential real options...

Water and Streambed-Sediment Quality in the Upper Elk River Basin, Missouri and Arkansas, 2004-06

USGS Publications Warehouse

Smith, Brenda J.; Richards, Joseph M.; Schumacher, John G.

2007-01-01

The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, collected water and streambedsediment samples in the Upper Elk River Basin in southwestern Missouri and northwestern Arkansas from October 2004 through December 2006. The samples were collected to determine the stream-water quality and streambed-sediment quality. In 1998, the Missouri Department of Natural Resources included a 21.5-mile river reach of the Elk River on the 303(d) list of impaired waters in Missouri as required by Section 303(d) of the Federal Clean Water Act. The Elk River is on the 303(d) list for excess nutrient loading. The total phosphorus distribution by decade indicates that the concentrations since 2000 have increased significantly from those in the 1960s, 1980s, and 1990s. The nitrate as nitrogen (nitrate) concentrations also have increased significantly in post-1985 from pre-1985 samples collected at the Elk River near Tiff City. Concentrations have increased significantly since the 1960s. Concentrations in the 1970s and 1980s, though similar, have increased from those in the 1960s, and the concentrations from the 1990s and 2000s increased still more. Nitrate concentrations significantly increased in samples that were collected during large discharges (greater than 355 cubic feet per second) from the Elk River near Tiff City. Nitrate concentrations were largest in Indian Creek. Several sources of nitrate are present in the basin, including poultry facilities in the upper part of the basin, effluent inflow from communities of Anderson and Lanagan, land-applied animal waste, chemical fertilizer, and possible leaking septic systems. Total phosphorus concentrations were largest in Little Sugar Creek. The median concentration of total phosphorus from samples from Little Sugar Creek near Pineville was almost four times the median concentration in samples from the Elk River near Tiff City. Median concentrations of nutrient species were greater in the stormwater samples than the median concentrations in the ambient samples. Nitrate concentrations in stormwater samples ranged from 133 to 179 percent of the concentration in the ambient samples. The total phosphorus concentrations in the stormwater samples ranged from about 200 to more than 600 percent of the concentration in the ambient samples. Base-flow conditions as reflected by the seepage run of the summer of 2006 indicate that 52 percent of the discharge at the Elk River near Tiff City is contributed by Indian Creek. Little Sugar Creek contributes 32 percent and Big Sugar Creek 9 percent of the discharge in the Elk River near Tiff City. Only about 7 percent of the discharge at Tiff City comes from the mainstem of the Elk River. Concentrations of dissolved ammonia plus organic nitrogen as nitrogen, dissolved ammonia as nitrogen, dissolved phosphorus, and dissolved orthophosphorus were detected in all streambed-sediment leachate samples. Concentrations of leachable nutrients in streambed-sediment samples generally tended to be slightly larger along the major forks of the Elk River as compared to tributary sites, with sites in the upper reaches of the major forks having among the largest concentrations. Concentrations of leachable nutrients in the major forks generally decreased with increasing distance downstream.

Water Quality Assessment of the Comal Springs Riverine System, New Braunfels, Texas, 1993-94

USGS Publications Warehouse

Fahlquist, Lynne; Slattery, R.N.

1997-01-01

Comal Springs of Central Texas are the largest springs in the southwestern United States. The long-term average flow of the Comal River, which essentially is the flow from Comal Springs, is 284 cubic feet per second (ft3/s). The artesian springs emerge at the base of an escarpment formed by the Comal Springs fault. The Comal River (fig. 1) is approximately 2 miles (mi) long and is a tributary of the Guadalupe River. Most of the Comal River follows the path of an old mill race, here referred to as New Channel, then flows through a channel carved by a tributary stream (Dry Comal Creek), eventually rejoining its original watercourse. The original watercourse, here referred to as Old Channel, has been reduced to a small stream, the source of which is water diverted from Landa Lake and several springs in the channel. In addition to being an important economic resource of the region, the springs and associated river system are home to unique aquatic species such as the endangered fountain darter (Etheostoma fonticola). The Comal Springs riffle beetle (Heterelmis comalensis), which exists in the springflow channel upstream of Landa Lake, has been proposed for listing as endangered. The Comal Springs dryopid beetle (Stygoparmus comalensis) and the Peck’s cave amphipod (Stygobromus pecki) are two subterranean species associated with Comal Springs also proposed for endangered listing.

Red River of the North Reconnaissance Report: Ottertail River Subbasin.

DTIC Science & Technology

1980-12-01

Excessive drainage in the future could diminish the ecological and recreational diversity of the subbasin. Water Quality Problems Some quality...manufacturing establishments are involved with agricultural or wood products. The two largest employers (between 750 and 1,250) are plants that process...RIVER SUBBASIN Estimated SIC Description Employment 20 Food and Kindred Products 1,850 23 Apparel made from fabrics 200 24 Lumber and Wood Products 600 25

Significant human impact on the flux and δ(34)S of sulfate from the largest river in North America.

PubMed

Killingsworth, Bryan A; Bao, Huiming

2015-04-21

Riverine dissolved sulfate (SO4(2-)) flux and sulfur stable isotope composition (δ(34)S) yield information on the sources and processes affecting sulfur cycling on different spatial and temporal scales. However, because pristine preindustrial natural baselines of riverine SO4(2-) flux and δ(34)S cannot be directly measured, anthropogenic impact remains largely unconstrained. Here we quantify natural and anthropogenic SO4(2-) flux and δ(34)S for North America's largest river, the Mississippi, by means of an exhaustive source compilation and multiyear monitoring. Our data and analysis show that, since before industrialization to the present, Mississippi River SO4(2-) has increased in flux from 7.0 to 27.8 Tg SO4(2-) yr(-1), and in mean δ(34)S from -5.0‰, within 95% confidence limits of -14.8‰ to 4.1‰ (assuming normal distribution for mixing model input parameters), to -2.7 ± 1.6‰, reflecting an impressive footprint of bedrocks particular to this river basin and human activities. Our first-order modern Mississippi River sulfate partition is 25 ± 6% natural and 75% ± 6% anthropogenic sources. Furthermore, anthropogenic coal usage is implicated as the dominant source of modern Mississippi River sulfate, with an estimated 47 ± 5% and 13% of total Mississippi River sulfate due to coal mining and burning, respectively.

[Variation characteristics of runoff coefficient of Taizi River basin in 1967-2006].

PubMed

Deng, Jun-Li; Zhang, Yong-Fang; Wang, An-Zhi; Guan, De-Xin; Jin, Chang-Jie; Wu, Jia-Bing

2011-06-01

Based on the daily precipitation and runoff data of six main embranchments (Haicheng River, Nansha River, Beisha River, Lanhe River, Xihe River, and Taizi River south embranchment) of Taizi River basin in 1967-2006, this paper analyzed the variation trend of runoff coefficient of the embranchments as well as the relationship between this variation trend and precipitation. In 1967-2006, the Taizi River south embranchment located in alpine hilly area had the largest mean annual runoff coefficient, while the Haicheng River located in plain area had the relatively small one. The annual runoff coefficient of the embranchments except Nansha River showed a decreasing trend, being more apparent for Taizi River south embranchment and Lanhe River. All the embranchments except Xihe River had an obvious abrupt change in the annual runoff coefficient, and the beginning year of the abrupt change differed with embranchment. Annual precipitation had significant effects on the annual runoff coefficient.

Study of the Qinghai-Tibetan Plateau Permafrost Active Layer Thickening Rate Using ALOS-1/-2 Interferometric SAR Data

NASA Astrophysics Data System (ADS)

Jia, Y.; Shum, C. K.; Kim, J.; Lu, Z.; Kuo, C. Y.; Zhang, L.; Ding, X.

2016-12-01

The Qinghai-Tibetan Plateau(QTP) is the world's largest and the highest plateau with distinct and competing surface and subsurface processes. It is the Third Pole and the World Water Tower, owing to its vast ice reservoir with the largest number of glaciers in the world. The QTP is covered by a large (1.3 to 1.6 million km2) layer of discontinuous and sporadic alpine permafrost, and is the origin of the largest rivers across Asia, feeding water to billions of people downstream. One such origin is the Three-River Headwater System, comprising of the mighty Yangtze, Yellow, and Lancang/Mekong Rivers, a subject of this study. The thawing over QTP permafrost regions is thought to be more severe compared with other high latitude permafrost regions by the fact that most of the permafrost is warm. During the past few decades, 10% permafrost has degraded. The overall mean active layer (AL) thickening rates over the QTP from model studies were 1.4 cm yr-1 during 1980-2001 and approximately 6.3 cm yr-1 during 2006-2010, based on soil temperature profiles for 27 monitoring sites along Qinghai-Tibetan railway (QTR). Here we report on a study on quantifying AL thickening rate in the northern QTP along the QTR, using ALOS-1/-2 InSAR observed land subsidence and AL thickness modeling. We have characterized high spatial resolution (30 m) and spatially varying ALT thickening rates, 2007-2010, along the QTR's large permafrost areas (> 10,000 km2). InSAR measured subsidence rates over various thermokarst surfaces in the study region are then converted to AL thickening rates using models with estimates ranging from 2.0 cm yr-1 to 10.7 cm yr-1. Comparisons with five borehole in situ sites showed excellent agreements with r2 >0.9. Using the ALOS-1/-2 InSAR data, we have further studied the plausible contribution of permafrost in NE QTP to the Yangtze headwater runoff near the Tuotuo river.

Simulating Multi-Scale Mercury Fate and Transport in a Coastal Plain Watershed

EPA Science Inventory

Mercury is the toxicant responsible for the largest number of fish advisories across the United States, with 1.1 million river miles under advisory. The processes governing fate, transport, and transformation of mercury in streams and rivers are not well understood, in large part...

Where Can You Buy a River?

ERIC Educational Resources Information Center

Coon-Come, Matthew

1991-01-01

Since 1975, Quebec hydroelectric projects have had negative impacts on the Cree hunting way of life and sacred sites, caused mercury contamination, and disrupted natural cycles of water and wildlife. Supported by contracts with New York State, new massive projects will destroy the six largest rivers in northwestern Quebec. (SV)

Impacts of large dams on the complexity of suspended sediment dynamics in the Yangtze River

NASA Astrophysics Data System (ADS)

Wang, Yuankun; Rhoads, Bruce L.; Wang, Dong; Wu, Jichun; Zhang, Xiao

2018-03-01

The Yangtze River is one of the largest and most important rivers in the world. Over the past several decades, the natural sediment regime of the Yangtze River has been altered by the construction of dams. This paper uses multi-scale entropy analysis to ascertain the impacts of large dams on the complexity of high-frequency suspended sediment dynamics in the Yangtze River system, especially after impoundment of the Three Gorges Dam (TGD). In this study, the complexity of sediment dynamics is quantified by framing it within the context of entropy analysis of time series. Data on daily sediment loads for four stations located in the mainstem are analyzed for the past 60 years. The results indicate that dam construction has reduced the complexity of short-term (1-30 days) variation in sediment dynamics near the structures, but that complexity has actually increased farther downstream. This spatial pattern seems to reflect a filtering effect of the dams on the on the temporal pattern of sediment loads as well as decreased longitudinal connectivity of sediment transfer through the river system, resulting in downstream enhancement of the influence of local sediment inputs by tributaries on sediment dynamics. The TGD has had a substantial impact on the complexity of sediment series in the mainstem of the Yangtze River, especially after it became fully operational. This enhanced impact is attributed to the high trapping efficiency of this dam and its associated large reservoir. The sediment dynamics "signal" becomes more spatially variable after dam construction. This study demonstrates the spatial influence of dams on the high-frequency temporal complexity of sediment regimes and provides valuable information that can be used to guide environmental conservation of the Yangtze River.

Improving the Representation of Estuarine Processes in Earth System Models

NASA Astrophysics Data System (ADS)

Sun, Q.; Whitney, M. M.; Bryan, F.; Tseng, Y. H.

2016-12-01

The exchange of freshwater between the rivers and estuaries and the open ocean represents a unique form of scale-interaction in the climate system. The local variability in the terrestrial hydrologic cycle is integrated by rivers over potentially large drainage basins (up to semi-continental scales), and is then imposed on the coastal ocean at the scale of a river mouth. Appropriately treating riverine freshwater discharge into the oceans in Earth system models is a challenging problem. Commonly, the river runoff is discharged into the ocean models with zero salinity and arbitrarily distributed either horizontally or vertically over several grid cells. Those approaches entirely neglect estuarine physical processes that modify river inputs before they reach the open ocean. A physically based Estuary Box Model (EBM) is developed to parameterize the mixing processes in estuaries. The EBM has a two-layer structure representing the mixing processes driven by tides and shear flow within the estuaries. It predicts the magnitude of the mixing driven exchange flow, bringing saltier lower-layer shelf water into the estuary to mix with river water prior to discharge to the upper-layer open ocean. The EBM has been tested against observations and high-resolution three-dimensional simulations of the Columbia River estuary, showing excellent agreement in the predictions of the strength of the exchange flow and the salinity of the discharged water, including modulation with the spring-neap tidal cycle. The EBM is implemented globally at every river discharge point of the Community Earth System Model (CESM). In coupled ocean-sea ice experiments driven by CORE surface forcing, the sea surface salinity (SSS) in the coastal ocean is increased globally compared to the standard model, contributing to a decrease in coastal stratification. The SSS near the mouths of some of the largest rivers is decreased due to the reduction in the area over which riverine fresh water is discharged. The results from experiments with the fully coupled CESM are broadly consistent, supporting the inclusion of the parameterization in CESM version 2 to be released in late 2016.

Interior River Lowland Ecoregion Summary Report

USGS Publications Warehouse

Karstensen, Krista A.

2008-01-01

ECOREGION DESCRIPTION The Interior River Lowlands ecoregion encompasses 93,200 square kilometers (km2) across southern and western Illinois, southwest Indiana, east-central Missouri, and fractions of northwest Kentucky and southeast Iowa. The ecoregion includes the confluence areas of the Mississippi, Missouri, Ohio, Illinois, and Wabash Rivers, and their tributaries. This ecoregion was formed in non-resident, non-calcareous sedimentary rock (U.S. Environmental Protection Agency, 2006). The unstratified soil deposits present north of the White River in Indiana are evidence that pre-Wisconsinan ice once covered much of the Interior River Lowlands. The geomorphic characteristics of this area also include terraced valleys filled with alluvium as well as outwash, acolian, and lacustrine deposits. Historically, agricultural land use has been a vital economic resource for this region. The drained alluvial soils are farmed for feed grains and soybeans, whereas the valley uplands also are used for forage crops, pasture, woodlots, mixed farming, and livestock (USEPA, 2006). This ecoregion provides a key component of national energy resources as it contains the second largest coal reserve in the United States, and the largest reserve of bituminous coal (Varanka and Shaver, 2007). One of the primary reasons for change in the ecoregion is urbanization.

Stream seepage and groundwater levels, Wood River Valley, south-central Idaho, 2012-13

USGS Publications Warehouse

Bartolino, James R.

2014-01-01

Stream discharge and water levels in wells were measured at multiple sites in the Wood River Valley, south-central Idaho, in August 2012, October 2012, and March 2013, as a component of data collection for a groundwater-flow model of the Wood River Valley aquifer system. This model is a cooperative and collaborative effort between the U.S. Geological Survey and the Idaho Department of Water Resources. Stream-discharge measurements for determination of seepage were made during several days on three occasions: August 27–28, 2012, October 22–24, 2012, and March 27–28, 2013. Discharge measurements were made at 49 sites in August and October, and 51 sites in March, on the Big Wood River, Silver Creek, their tributaries, and nearby canals. The Big Wood River generally gains flow between the Big Wood River near Ketchum streamgage (13135500) and the Big Wood River at Hailey streamgage (13139510), and loses flow between the Hailey streamgage and the Big Wood River at Stanton Crossing near Bellevue streamgage (13140800). Shorter reaches within these segments may differ in the direction or magnitude of seepage or may be indeterminate because of measurement uncertainty. Additional reaches were measured on Silver Creek, the North Fork Big Wood River, Warm Springs Creek, Trail Creek, and the East Fork Big Wood River. Discharge measurements also were made on the Hiawatha, Cove, District 45, Glendale, and Bypass Canals, and smaller tributaries to the Big Wood River and Silver Creek. Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established by the U.S. Geological Survey in 2006. Maps of the October 2012 water-table altitude in the unconfined aquifer and the potentiometric-surface altitude of the confined aquifer have similar topology to those on maps of October 2006 conditions. Between October 2006 and October 2012, water-table altitude in the unconfined aquifer rose by as much as 1.86 feet in 6 wells and declined by as much as 14.28 feet in 77 wells; average decline was 2.9 feet. A map of changes in the water‑table altitude of the unconfined aquifer shows that the largest declines were in tributary canyons and in an area roughly between Baseline and Glendale Roads. From October 2006 to October 2012, the potentiometric-surface altitude in 10 wells completed in the confined aquifer declined between 0.12 and 20.50 feet; average decline was 6.8 feet. A map of changes in the potentiometric-surface altitude of the confined aquifer shows that the largest declines were in the southwestern part of the Bellevue fan. Reduced precipitation prior to the October 2012 water-level measurements likely is partially responsible for 2006–12 water-table declines in the unconfined aquifer; the relative contribution of precipitation deficit and groundwater withdrawals to the declines is not known. Although the confined aquifer may not receive direct recharge from precipitation or streams, groundwater withdrawal from the confined aquifer induces flow from the unconfined aquifer. Declines in the confined aquifer are likely due to groundwater withdrawals and declines in the water table of the unconfined aquifer. A statistical analysis of five long-term monitoring wells (three completed in the unconfined aquifer, one in the confined aquifer, and one outside the aquifer system boundary) showed statistically significant declining trends in four wells.

40Ar/39Ar mica dating of late Cenozoic sediments in the upper Yangtze: Implications for sediment provenance and drainage evolution

NASA Astrophysics Data System (ADS)

Sun, Xilin; Li, Chang'an; Kuiper, Kuiper; Zhang, Zengjie; Wijbrans, Jan

2017-04-01

The development of the river systems in East Asia is closely linked to the uplift of the Tibetan plateau caused by collision of the India-Eurasia. The Yangtze River is the largest river in Asia and the timing and exact causes of its formation are still a matter of debate. Controversy exists for example on the start of the connection of the eastern Tibetan rivers to the eastward flowing Yangtze instead of the southward flowing Red River. Here we use the 40Ar/39Ar dating of detrital micas (muscovite and biotite) and muscovite geochemistry to constrain the sediment provenance in the eastern Tibetan Plateau. The remarkable spatial and temporal variation in sediment provenance allow us to extract information about the evolution of the upper Yangtze River. The combined data suggest that the upper Jinsha River upstream from Shigu town lost its connection with the southward flowing Red River at least earlier than the Pliocene. To the east of Shigu, the Yalong and Jinsha rivers flowed across the Yuanmou Basin into the Red River before 3.1 Ma, but abandoned this connection and turned east somewhere between 3.1 and 2.1 Ma. Our results rule out the possibility of a west-flowing Jinsha River since 1.58 Ma. The current stream directions between Shigu and Panzhihua go north, south and east and must have been formed at that time. Our data also shed new light on the evolution of the Dadu River. The Dadu River did not flow southward into Yuanmou Basin at least since 4.8 Ma but flowed into the Jinsha River along the Anninghe Fault. These capture events are closely linked to the tectonism of the eastern Tibetan Plateau and intensification of the East Asia monsoon.

Geohydrologic Investigations and Landscape Characteristics of Areas Contributing Water to Springs, the Current River, and Jacks Fork, Ozark National Scenic Riverways, Missouri

USGS Publications Warehouse

Mugel, Douglas N.; Richards, Joseph M.; Schumacher, John G.

2009-01-01

The Ozark National Scenic Riverways (ONSR) is a narrow corridor that stretches for approximately 134 miles along the Current River and Jacks Fork in southern Missouri. Most of the water flowing in the Current River and Jacks Fork is discharged to the rivers from springs within the ONSR, and most of the recharge area of these springs is outside the ONSR. This report describes geohydrologic investigations and landscape characteristics of areas contributing water to springs and the Current River and Jacks Fork in the ONSR. The potentiometric-surface map of the study area for 2000-07 shows that the groundwater divide extends beyond the surface-water divide in some places, notably along Logan Creek and the northeastern part of the study area, indicating interbasin transfer of groundwater between surface-water basins. A low hydraulic gradient occurs in much of the upland area west of the Current River associated with areas of high sinkhole density, which indicates the presence of a network of subsurface karst conduits. The results of a low base-flow seepage run indicate that most of the discharge in the Current River and Jacks Fork was from identified springs, and a smaller amount was from tributaries whose discharge probably originated as spring discharge, or from springs or diffuse groundwater discharge in the streambed. Results of a temperature profile conducted on an 85-mile reach of the Current River indicate that the lowest average temperatures were within or downstream from inflows of springs. A mass-balance on heat calculation of the discharge of Bass Rock Spring, a previously undescribed spring, resulted in an estimated discharge of 34.1 cubic feet per second (ft3/s), making it the sixth largest spring in the Current River Basin. The 13 springs in the study area for which recharge areas have been estimated accounted for 82 percent (867 ft3/s of 1,060 ft3/s) of the discharge of the Current River at Big Spring during the 2006 seepage run. Including discharge from other springs, the cumulative discharge from springs was over 90 percent of the river discharge at most of the spring locations, and was 92 percent at Big Spring and at the lower end of the ONSR. The discharge from the 1.9-mile long Pulltite Springs Complex measured in the 2006 seepage run was 88 ft3/s. Most of this (77 ft3/s) was from the first approximately 0.25 mi of the Pulltite Springs Complex. It has been estimated that the annual mean discharge from the Current River Springs Complex is 125 ft3/s, based on an apparent discharge of 50 ft3/s during a 1966 U.S. Geological Survey seepage run. However, a reinterpretation of the 1966 seepage run data shows that the discharge from the Current River Springs Complex instead was about 12.6 ft3/s, and the annual mean discharge was estimated to be 32 ft3/s, substantially less than 125 ft3/s. The 2006 seepage run showed a gain of only 12 ft3/s from the combined Round Spring and Current River Springs Complex from the mouth of Sinking Creek to 0.7 mi upstream from Root Hollow. The 2006 temperature profile measurements did not indicate any influx of spring discharge throughout the length of the Current River Springs Complex. The spring recharge areas with the largest number of identified sinkholes are Big Spring, Alley Spring, and Welch Spring. The spring recharge areas with the largest number of sinkholes per square mile of recharge area are Alley Spring, Blue Spring (Jacks Fork), Welch Spring, and Round Spring and the Current River Springs Complex. Using the currently known locations of losing streams, the Big Spring recharge area has the largest number of miles of losing stream, and the Bass Rock Spring recharge area has the largest number of miles of losing stream per unit recharge area. The spring recharge areas with the most open land and the least forested land per unit recharge area are Blue Spring (Jacks Fork), Welch Spring, Montauk Springs, and Alley Spring. The spring recharge areas with the least amount

Hydrologic indicators of hot spots and hot moments of mercury methylation potential along river corridors

USGS Publications Warehouse

Singer, Michael B.; Harrison, Lee R.; Donovan, Patrick M.; Blum, Joel D.; Marvin-DiPasquale, Mark C.

2016-01-01

The biogeochemical cycling of metals and other contaminants in river-floodplain corridors is controlled by microbial activity responding to dynamic redox conditions. Riverine flooding thus has the potential to affect speciation of redox-sensitive metals such as mercury (Hg). Therefore, inundation history over a period of decades potentially holds information on past production of bioavailable Hg. We investigate this within a Northern California river system with a legacy of landscape-scale 19th century hydraulic gold mining. We combine hydraulic modeling, Hg measurements in sediment and biota, and first-order calculations of mercury transformation to assess the potential role of river floodplains in producing monomethylmercury (MMHg), a neurotoxin which accumulates in local and migratory food webs. We identify frequently inundated floodplain areas, as well as floodplain areas inundated for long periods. We quantify the probability of MMHg production potential (MPP) associated with hydrology in each sector of the river system as a function of the spatial patterns of overbank inundation and drainage, which affect long-term redox history of contaminated sediments. Our findings identify river floodplains as periodic, temporary, yet potentially important, loci of biogeochemical transformation in which contaminants may undergo change during limited periods of the hydrologic record. We suggest that inundation is an important driver of MPP in river corridors and that the entire flow history must be analyzed retrospectively in terms of inundation magnitude and frequency in order to accurately assess biogeochemical risks, rather than merely highlighting the largest floods or low-flow periods. MMHg bioaccumulation within the aquatic food web in this system may pose a major risk to humans and waterfowl that eat migratory salmonids, which are being encouraged to come up these rivers to spawn. There is a long-term pattern of MPP under the current flow regime that is likely to be accentuated by increasingly common large floods with extended duration.

Hydrologic indicators of hot spots and hot moments of mercury methylation potential along river corridors.

PubMed

Singer, Michael Bliss; Harrison, Lee R; Donovan, Patrick M; Blum, Joel D; Marvin-DiPasquale, Mark

2016-10-15

The biogeochemical cycling of metals and other contaminants in river-floodplain corridors is controlled by microbial activity responding to dynamic redox conditions. Riverine flooding thus has the potential to affect speciation of redox-sensitive metals such as mercury (Hg). Therefore, inundation history over a period of decades potentially holds information on past production of bioavailable Hg. We investigate this within a Northern California river system with a legacy of landscape-scale 19th century hydraulic gold mining. We combine hydraulic modeling, Hg measurements in sediment and biota, and first-order calculations of mercury transformation to assess the potential role of river floodplains in producing monomethylmercury (MMHg), a neurotoxin which accumulates in local and migratory food webs. We identify frequently inundated floodplain areas, as well as floodplain areas inundated for long periods. We quantify the probability of MMHg production potential (MPP) associated with hydrology in each sector of the river system as a function of the spatial patterns of overbank inundation and drainage, which affect long-term redox history of contaminated sediments. Our findings identify river floodplains as periodic, temporary, yet potentially important, loci of biogeochemical transformation in which contaminants may undergo change during limited periods of the hydrologic record. We suggest that inundation is an important driver of MPP in river corridors and that the entire flow history must be analyzed retrospectively in terms of inundation magnitude and frequency in order to accurately assess biogeochemical risks, rather than merely highlighting the largest floods or low-flow periods. MMHg bioaccumulation within the aquatic food web in this system may pose a major risk to humans and waterfowl that eat migratory salmonids, which are being encouraged to come up these rivers to spawn. There is a long-term pattern of MPP under the current flow regime that is likely to be accentuated by increasingly common large floods with extended duration. Copyright © 2016 Elsevier B.V. All rights reserved.

Mount St. Helens 30 years later: a landscape reconfigured.

Treesearch

Rhonda Mazza

2010-01-01

On May 18, 1980, after two months of tremors, Mount St. Helens erupted spectacularly and profoundly changed a vast area surrounding the volcano. The north slope of the mountain catastrophically failed, forming the largest landslide witnessed in modern times. The largest lobe of this debris avalanche raced 14 miles down the Toutle River...

Connecting large-scale atmospheric circulation, river flow and groundwater levels in a chalk catchment in southern England

NASA Astrophysics Data System (ADS)

Lavers, David A.; Hannah, David M.; Bradley, Chris

2015-04-01

Groundwater is an important water resource and globally it represents the largest distributed store of freshwater. In southern England, groundwater is a major source for public water supply, and many aquifers have recently experienced both extreme low and high groundwater levels. In this paper, we use observations of precipitation, river discharge and groundwater levels (1964-2010) and an atmospheric reanalysis to explore the large-scale climate patterns preceding the nine highest and lowest March river discharge and groundwater levels in the chalk catchment of the River Lambourn (Berkshire Downs, southern England). Peak monthly precipitation is shown to occur from October to January, while the highest river discharge and groundwater levels are found from February to April. For high discharge/groundwater levels, composite anomaly patterns of the mean sea level pressure show a stronger than average pressure gradient across the North Atlantic Ocean, with enhanced water vapour transport across southern England. For the lowest discharge/groundwater levels, a blocking high pressure system is found across the British Isles deflecting storms and precipitation to the north. Significantly, the intra-composite variability suggests that different sequences of atmospheric states may lead to high and low discharge/groundwater events.

Characterization of hydrodynamic and sediment conditions in the lower Yampa River at Deerlodge Park, east entrance to Dinosaur National Monument, northwest Colorado, 2011

USGS Publications Warehouse

Williams, Cory A.

2013-01-01

The Yampa River in northwestern Colorado is the largest, relatively unregulated river system in the upper Colorado River Basin. Water from the Yampa River Basin continues to be sought for a number of municipal, industrial, and energy uses. It is anticipated that future water development within the Yampa River Basin above the amount of water development identified under the Upper Colorado River Endangered Fish Recovery Implementation Program and the Programmatic Biological Opinion may require additional analysis in order to understand the effects on habitat and river function. Water development in the Yampa River Basin could alter the streamflow regime and, consequently, could lead to changes in the transport and storage of sediment in the Yampa River at Deerlodge Park. These changes could affect the physical form of the reach and may impact aquatic and riparian habitat in and downstream from Deerlodge Park. The U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, began a study in 2011 to characterize the current hydrodynamic and sediment-transport conditions for a 2-kilometer reach of the Yampa River in Deerlodge Park. Characterization of channel conditions in the Deerlodge Park reach was completed through topographic surveying, grain-size analysis of streambed sediment, and characterization of streamflow properties. This characterization provides (1) a basis for comparisons of current stream functions (channel geometry, sediment transport, and stream hydraulics) to future conditions and (2) a dataset that can be used to assess channel response to streamflow alteration scenarios indicated from computer modeling of streamflow and sediment-transport conditions.

Estimated withdrawals and use of freshwater in New Hampshire, 1990

USGS Publications Warehouse

Medalie, Laura; Horn, M.A.

1994-01-01

Estimated freshwater withdrawals during 1990 in New Hampshire totaled about 422 million gallons per day from ground-water and surface-water sources. The largest withdrawals were for thermoelectric-power generation (60 percent), public supply (23 percent), and industrial use (9 percent). Most withdrawals, 358 million gallons per day, were made from surface- water sources, as compared to 63.7 million gallons per day from ground-water sources. The largest with- drawals were in the Merrimack river basin (322 million gallons per day). An additional 46,000 million gallons per day was used instream for hydroelectric-power generation, primarily in the Upper Androscoggin and Upper Connecticut River subbasins. Other information describing water-use patterns is shown in tables, bar graphs, pie charts, maps, and accompanying text. The data are aggregated by river basin (hydrologic cataloging unit), and all values are reported in million gallons per day.

Rapid water quality change in the Elwha River estuary complex during dam removal

USGS Publications Warehouse

Foley, Melissa M.; Duda, Jeffrey J.; Beirne, Matthew M.; Paradis, Rebecca; Ritchie, Andrew; Warrick, Jonathan A.

2015-01-01

Dam removal in the United States is increasing as a result of structural concerns, sedimentation of reservoirs, and declining riverine ecosystem conditions. The removal of the 32 m Elwha and 64 m Glines Canyon dams from the Elwha River in Washington, U.S.A., was the largest dam removal project in North American history. During the 3 yr of dam removal—from September 2011 to August 2014—more than ten million cubic meters of sediment was eroded from the former reservoirs, transported downstream, and deposited throughout the lower river, river delta, and nearshore waters of the Strait of Juan de Fuca. Water quality data collected in the estuary complex at the mouth of the Elwha River document how conditions in the estuary changed as a result of sediment deposition over the 3 yr the dams were removed. Rapid and large-scale changes in estuary conditions—including salinity, depth, and turbidity—occurred 1 yr into the dam removal process. Tidal propagation into the estuary ceased following a large sediment deposition event that began in October 2013, resulting in decreased salinity, and increased depth and turbidity in the estuary complex. These changes have persisted in the system through dam removal, significantly altering the structure and functioning of the Elwha River estuary ecosystem.

Evaluation of an operational water cycle prediction system for the Laurentian Great Lakes and St. Lawrence River

NASA Astrophysics Data System (ADS)

Fortin, Vincent; Durnford, Dorothy; Smith, Gregory; Dyck, Sarah; Martinez, Yosvany; Mackay, Murray; Winter, Barbara

2017-04-01

Environment and Climate Change Canada (ECCC) is implementing new numerical guidance products based on fully coupled numerical models to better inform the public as well as specialized users on the current and future state of various components of the water cycle, including stream flow and water levels. Outputs from this new system, named the Water Cycle Prediction System (WCPS), have been available for the Great Lakes and St. Lawrence River watershed since June 2016. WCPS links together ECCC's weather forecasting model, GEM, the 2-D ice model C-ICE, the 3-D lake and ocean model NEMO, and a 2-D hydrological model, WATROUTE. Information concerning the water cycle is passed between the models at intervals varying from a few minutes to one hour. It currently produces two forecasts per day for the next three days of the complete water cycle in the Great Lakes region, the largest freshwater lake system in the world. Products include spatially-varying precipitation, evaporation, river discharge, water level anomalies, surface water temperatures, ice coverage, and surface currents. These new products are of interest to water resources and management authority, flood forecasters, hydroelectricity producers, navigation, environmental disaster managers, search and rescue teams, agriculture, and the general public. This presentation focuses on the evaluation of various elements forecasted by the system, and weighs the advantages and disadvantages of running the system fully coupled.

Low Freshwater Inflow Study. Chesapeake Bay Hydraulic Model Investigation.

DTIC Science & Technology

1982-01-01

Bay with its tributary estuaries forms the largest estuarine system in North America. Between its mouth at the Virginia Capes and its head at Turkey...stratification. Sta PO-02-02 (at the mouth of the river), however, shows this seasonal response to a lesser degree. The distance from the freshwater...boundary and the closeness to the local saltwater boundary at the mouth of the Potomac are thought to be responsible for this phenomenon. 64. Another

The Fall River Long-Term Site Productivity study in coastal Washington: site characteristics, methods, and biomass and carbon and nitrogen stores before and after harvest.

Treesearch

Adrian Ares; Thomas A. Terry; Kathryn B. Piatek; Robert B. Harrison; Richard E. Miller; Barry L. Flaming; ChristopherW Licata; Brian D. Strahm; Constance A. Harrington; Rodney Meade; Harry W. Anderson; Leslie C. Brodie; Joseph M. Kraft

2007-01-01

The Fall River research site in coastal Washington is an affiliate installation of the North American Long-Term Soil Productivity (LTSP) network, which constitutes one of the world’s largest coordinated research programs addressing forest management impacts on sustained productivity. Overall goals of the Fall River study are to assess effects of biomass removals, soil...

Mighty Microbes Where Rivers Run

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

Stegen, James

2016-04-07

Microbes and their influential role in Earth’s climate take center stage in the area where river water and groundwater mix – an area known as the hyporheic zone. PNNL ecologist James Stegen discusses his team’s research in his “laboratory” – the zone along the Columbia, one of the nation’s largest rivers. It’s a squishy, porous lab, better known for soaking feet than serving as the “river’s liver.”

Water Demand Management Strategies and Challenges in the Upper Colorado River Basin

NASA Astrophysics Data System (ADS)

Kuhn, R. E.

2016-12-01

Under the 1922 Colorado River Compact, the Upper Basin (Colorado, New Mexico, Utah, and Wyoming) has flow obligations at Lee Ferry to downstream states and Mexico. The Colorado River Storage Project Act (CRSPA) of 1956 led to the construction of four large storage reservoirs. These provide river regulation to allow the Upper Basin to meet its obligations. Lake Powell, the largest and most important, and Lake Mead are now operated in a coordinated manner under the 2007 Interim Guidelines. Studies show that at current demand levels and if the hydrologic conditions the Basin has experienced since the mid-1980s continue or get drier, reservoir operations, alone, may not provide the necessary water to meet the Upper Basin's obligations. Therefore, the Upper Basin states are now studying demand management strategies that will reduce consumptive uses when total system reservoir storage reaches critically low levels. Demand management has its own economic, political and technical challenges and limitations and will provide new opportunities for applied research. This presentation will discuss some of those strategies, their challenges, and the kinds of information that research could provide to inform demand management.

Glacial history and runoff components of the Tlikakila River Basin, Lake Clark National Park and Preserve, Alaska

USGS Publications Warehouse

Brabets, Timothy P.; March, Rod S.; Trabant, Dennis C.

2004-01-01

The Tlikakila River is located in Lake Clark National Park and Preserve and drains an area of 1,610 square kilometers (622 square miles). Runoff from the Tlikakila River Basin accounts for about one half of the total inflow to Lake Clark. Glaciers occupy about one third of the basin and affect the runoff characteristics of the Tlikakila River. As part of a cooperative study with the National Park Service, glacier changes and runoff characteristics in the Tlikakila River Basin were studied in water years 2001 and 2002. Based on analyses of remote sensing data and on airborne laser profiling, most glaciers in the Tlikakila River Basin have retreated and thinned from 1957 to the present. Volume loss from 1957-2001 from the Tanaina Glacier, the largest glacier in the Tlikakila River Basin, was estimated to be 6.1 x 109 cubic meters or 1.4 x 108 cubic meters per year. For the 2001 water year, mass balance measurements made on the three largest glaciers in the Tlikakila River BasinTanaina, Glacier Fork, and North Forkall indicate a negative mass balance. Runoff measured near the mouth of the Tlikakila River for water year 2001 was 1.70 meters. Of this total, 0.18 meters (11 percent) was from glacier ice melt, 1.27 meters (75 percent) was from snowmelt, 0.24 meters (14 percent) was from rainfall runoff, and 0.01 meters (1 percent) was from ground water. Although ground water is a small component of runoff, it provides a critical source of warm water for fish survival in the lower reaches of the Tlikakila River.

A review of crust and upper mantle structure studies of the Snake River Plain-Yellowstone volcanic system: A major lithospheric anomaly in the western U.S.A.

USGS Publications Warehouse

Iyer, H.M.

1984-01-01

The Snake River Plain-Yellowstone volcanic system is one of the largest, basaltic, volcanic field in the world. Here, there is clear evidence for northeasterly progression of rhyolitic volcanism with its present position in Yellowstone. Many theories have been advanced for the origin of the Snake River Plain-Yellowstone system. Yellowstone and Eastern Snake River Plain have been studied intensively using various geophysical techniques. Some sparse geophysical data are available for the Western Snake River Plain as well. Teleseismic data show the presence of a large anomalous body with low P- and S-wave velocities in the crust and upper mantle under the Yellowstone caldera. A similar body in which compressional wave velocity is lower than in the surrounding rock is present under the Eastern Snake River Plain. No data on upper mantle anomalies are available for the Western Snake River Plain. Detailed seismic refraction data for the Eastern Snake River Plain show strong lateral heterogeneities and suggest thinning of the granitic crust from below by mafic intrusion. Available data for the Western Snake River Plain also show similar thinning of the upper crust and its replacement by mafic material. The seismic refraction results in Yellowstone show no evidence of the low-velocity anomalies in the lower crust suggested by teleseismic P-delay data and interpreted as due to extensive partial melting. However, the seismic refraction models indicate lower-than-normal velocities and strong lateral inhomogeneities in the upper crust. Particularly obvious in the refraction data are two regions of very low seismic velocities near the Mallard Eake and Sour Creek resurgent domes in the Yellowstone caldera. The low-velocity body near the Sour Creek resurgent dome is intepreted as partially molten rock. Together with other geophysical and thermal data, the seismic results indicate that a sub-lithospheric thermal anomaly is responsible for the time-progressive volcanism along the Eastern Snake River Plain. However, the exact mechanism responsible for the volcanism and details of magma storage and migration are not yet fully understood. ?? 1984.

Sensitivity of the Freshwater Plume to Winds in the Bay of Bengal

NASA Astrophysics Data System (ADS)

Sandeep, K. K.; Pant, V.; Rao, A. D.

2016-12-01

The role of winds in determining the dispersal pattern of freshwater plume in the Bay of Bengal (BoB) is investigated by using a high resolution three dimensional Regional Ocean Modelling System (ROMS) with realistic coastline and bathymetry. In the Indian Ocean, the Bay of Bengal (BoB) receives substantial freshwater by excess precipitation over evaporation and river runoff. Major rivers like Ganges, Brahmaputra, Mahanadi, Godavari, Krishna, Irrawaddy discharge freshwater volume in range between 1.5 x 1012 m3 and 1.83 x 1013 m3. About three-fourths of all riverine influx into the BoB occurs during the summer monsoon period from May until September. Multiple experiments are carried out with idealized winds replicating the seasonal wind patterns in the study region. Idealized winds of 8ms-1 with directions as southwesterly, southeasterly, northeasterly, and northerly used to force the model. Monthly climatology of river discharge from the seven major rivers in the domain are included by identifying their geographic locations. Model simulations show distinct behavioural patterns of the dispersal of riverine freshwater plumes in response to the direction of idealized winds. Comparison of different idealized experiments show the largest variability of the transport pathways in the northern BoB, where the largest freshwater volume is discharged through the rivers Ganges and Brahmaputra. Freshwater pool remains bounded to the northern-northeastern boundary of the BoB when forced with southwesterly winds, whereas the northeasterly winds produce a remarkable southward transport of freshwater along the east coast of India. These signatures of low salinity waters along the east coast of India have also been observed in observations during October-November. Further, the southeasterly winds produce strong mixing of low saline waters in the northern BoB. The northerly wind stress, however, limits the channelized flow of riverine freshwater either through the eastern or western boundary of the BoB.

Global Anthropogenic Phosphorus Loads to Fresh Water, Grey Water Footprint and Water Pollution Levels: A High-Resolution Global Study

NASA Astrophysics Data System (ADS)

Mekonnen, M. M.; Hoekstra, A. Y. Y.

2014-12-01

We estimated anthropogenic phosphorus (P) loads to freshwater, globally at a spatial resolution level of 5 by 5 arc minute. The global anthropogenic P load to freshwater systems from both diffuse and point sources in the period 2002-2010 was 1.5 million tonnes per year. China contributed about 30% to this global anthropogenic P load. India was the second largest contributor (8%), followed by the USA (7%), Spain and Brazil each contributing 6% to the total. The domestic sector contributed the largest share (54%) to this total followed by agriculture (38%) and industry (8%). Among the crops, production of cereals had the largest contribution to the P loads (32%), followed by fruits, vegetables, and oil crops, each contributing about 15% to the total. We also calculated the resultant grey water footprints, and relate the grey water footprints per river basin to runoff to calculate the P-related water pollution level (WPL) per catchment.

Public health aspects of the world's largest mass gathering: The 2013 Kumbh Mela in Allahabad, India.

PubMed

Balsari, Satchit; Greenough, P Gregg; Kazi, Dhruv; Heerboth, Aaron; Dwivedi, Shraddha; Leaning, Jennifer

2016-12-01

India's Kumbh Mela remains the world's largest and longest mass gathering. The 2013 event, where participants undertook a ritual bath, hosted over 70 million Hindu pilgrims during 55 days on a 1936 hectare flood plain at the confluence of the Yamuna and Ganga Rivers. On the holiest bathing days, the population surged. Unlike other religious, cultural, and sports mass gatherings, the Kumbh Mela's administration cannot estimate or limit the participant number. The event created serious and uncommon public health challenges: initiating crowd safety measures where population density and mobility directly contact flowing bodies of water; providing water, sanitation, and hygiene to a population that frequently defecates in the open; and establishing disease surveillance and resource use measures within a temporary health delivery system. We review the world's largest gathering by observing first-hand the public health challenges, plus the preparations for and responses to them. We recommend ways to improve preparedness.

Climate-driven changes in riverine inputs affecting the stoichiometry of Earth's largest lake

NASA Astrophysics Data System (ADS)

Sterner, R.; Small, G. E.

2014-12-01

Lake Superior, Earth's largest lake by area, has seen a steady increase in nitrate levels over the past century, while phosphorus remains exceedingly low, resulting in an increasingly imbalanced stoichiometry. Although its ratio of watershed area:lake area is relatively small, rivers emptying into Lake Superior could be important drivers of long-term changes in lake stoichiometry. To better assess how the Lake Superior watershed affects its stoichiometry, we examined the chemistry of two of its largest tributaries, the Saint Louis River and the Nipigon River, at their confluences with Lake Superior. Both of these rivers have high dissolved organic carbon (DOC) but low nitrate (NO3) concentrations relative to the lake. Using simple mixing models, we found these nearshore confluences to create sinks of lake NO3 as a result of relatively high rates of denitrification. Climate change is altering the amounts and patterns of delivery of materials from land to lakes and we also examined the plume from a June, 2012 100-year flood in the Saint Louis River. Three days after this historic rain event, we found elevated chlorophyll levels throughout the plume, up to 5-fold higher than in the open lake. Combining our samples with satellite imagery, we conservatively estimate that this plume contained 598,000 kg of phosphorus in dissolved and particulate form, or 40% of the average annual P input to the lake. If storm events such as this occur with increasing frequency as predicted in climate change scenarios, the lake's productivity may increase and stoichiometry could become more balanced, through greater P input and increased N retention due to sedimentation and denitrification.

Modeling Mercury Exposure at Different Scales in the McTier Creek Watershed and Edisto River Basin, SC USA

EPA Science Inventory

Mercury is the toxicant responsible for the largest number of fish advisories across the United States, with 1.25 million miles of rivers under advisory. The processes governing fate, transport, and transformation of mercury in lotic ecosystems are not well-understood, in large p...

A Murray Cod Assemblage: Re/Considering Riverscape Pedagogy

ERIC Educational Resources Information Center

Stewart, Alistair James

2018-01-01

This article enacts Deleuze and Guattari's (1987) concept "assemblage" to craft a riverScape pedagogy that is informed by, and responsive to, the Murray Cod, the river, and its circumstances. The Murray Cod, the largest fish species in Australia's Murray-Darling Basin, has diverse cultural meanings. Cod are at once a creation being of…

Management needs assessment for the Copper River Delta, Alaska.

Treesearch

L.E. Kruger; C.B. Tyler

1995-01-01

This report assesses needs, problems, and perceptions relevant to management for the Copper River Delta (Alaska)—the largest coastal wetland on the Pacific coast of North America. The assessment provides a basis for planning and decisionmaking and a framework for ongoing research, development, and application. It also underscores concerns about human impacts...

Modeling Mercury Exposure at Different Scales in the McTier Creek Watershed and Edisto River Basin SC USA

EPA Science Inventory

Mercury (Hg) is the toxicant responsible for the largest number of fish advisories across the United States, with 1.25 million river miles under advisory. The processes governing fate, transport, and transformation of Hg in lotic ecosystems are not well-understood, in large part...

Observational evidence for turbulent effects on total suspended matter within the Pearl River plume

NASA Astrophysics Data System (ADS)

Chunhua, Qiu; Danyi, Su; Huabin, Mao; Jiaxue, Wu; Yongsheng, Cui; Dongxiao, Wang

2017-12-01

We observed the structure of the Pearl River plume and its turbulent characteristics, and investigated the turbulent effect on total suspended matter (TSM) within its ;far-field; region, based on in situ and satellite data collected in June 2015. A significant northeastward plume was created under southern monsoonal conditions. The in situ data provided the width, depth, and velocity of the plume, as inferred by salinity. Weaker turbulence occurred at the front surface position than in the plume zone. Stronger turbulence induced greater turbidity in the bottom boundary layer; however, the surface mixed layer differed. By estimating the turbidity budget, we found the lateral fluxes term was the largest term in the plume, turbulent fluxes comprised the second largest term, and the settling terms comprised the smallest term. We quantified the turbulent mechanisms and found that stronger river discharge induced greater TSM turbidity. Tidal and buoyancy fluxes had minor regulatory effects on TSM. Our observations suggest that TSM in the ;far field; region originated from the Pearl River and the coastal region.

Suspended-sediment concentrations, loads, total suspended solids, turbidity, and particle-size fractions for selected rivers in Minnesota, 2007 through 2011

USGS Publications Warehouse

Ellison, Christopher A.; Savage, Brett E.; Johnson, Gregory D.

2014-01-01

Sediment-laden rivers and streams pose substantial environmental and economic challenges. Excessive sediment transport in rivers causes problems for flood control, soil conservation, irrigation, aquatic health, and navigation, and transports harmful contaminants like organic chemicals and eutrophication-causing nutrients. In Minnesota, more than 5,800 miles of streams are identified as impaired by the Minnesota Pollution Control Agency (MPCA) due to elevated levels of suspended sediment. The U.S. Geological Survey, in cooperation with the MPCA, established a sediment monitoring network in 2007 and began systematic sampling of suspended-sediment concentrations (SSC), total suspended solids (TSS), and turbidity in rivers across Minnesota to improve the understanding of fluvial sediment transport relations. Suspended-sediment samples collected from 14 sites from 2007 through 2011 indicated that the Zumbro River at Kellogg in the driftless region of southeast Minnesota had the highest mean SSC of 226 milligrams per liter (mg/L) followed by the Minnesota River at Mankato with a mean SSC of 193 mg/L. During the 2011 spring runoff, the single highest SSC of 1,250 mg/L was measured at the Zumbro River. The lowest mean SSC of 21 mg/L was measured at Rice Creek in the northern Minneapolis- St. Paul metropolitan area. Total suspended solids (TSS) have been used as a measure of fluvial sediment by the MPCA since the early 1970s; however, TSS concentrations have been determined to underrepresent the amount of suspended sediment. Because of this, the MPCA was interested in quantifying the differences between SSC and TSS in different parts of the State. Comparisons between concurrently sampled SSC and TSS indicated significant differences at every site, with SSC on average two times larger than TSS concentrations. The largest percent difference between SSC and TSS was measured at the South Branch Buffalo River at Sabin, and the smallest difference was observed at the Des Moines River at Jackson. Regression analysis indicated that 7 out of 14 sites had poor or no relation between SSC and streamflow. Only two sites, the Knife River and the Wild Rice River at Twin Valley, had strong correlations between SSC and streamflow, with coefficient of determination (R2) values of 0.82 and 0.80, respectively. In contrast, turbidity had moderate to strong relations with SSC at 10 of 14 sites and was superior to streamflow for estimating SSC at all sites. These results indicate that turbidity may be beneficial as a surrogate for SSC in many of Minnesota’s rivers. Suspended-sediment loads and annual basin yields indicated that the Minnesota River had the largest average annual sediment load of 1.8 million tons per year and the largest mean annual sediment basin yield of 120 tons of sediment per year per square mile. Annual TSS loads were considerably lower than suspended-sediment loads. Overall, the largest suspended-sediment and TSS loads were transported during spring snowmelt runoff, although loads during the fall and summer seasons occasionally exceeded spring runoff at some sites. This study provided data from which to characterize suspended sediment across Minnesota’s diverse geographical settings. The data analysis improves understanding of sediment transport relations, provides information for improving sediment budgets, and documents baseline data to aid in understanding the effects of future land use/land cover on water quality. Additionally, the data provides insight from which to evaluate the effectiveness and efficiency of best management practices at the watershed scale.

Water-quality characteristics, including sodium-adsorption ratios, for four sites in the Powder River drainage basin, Wyoming and Montana, water years 2001-2004

USGS Publications Warehouse

Clark, Melanie L.; Mason, Jon P.

2006-01-01

The U.S. Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, monitors streams throughout the Powder River structural basin in Wyoming and parts of Montana for potential effects of coalbed natural gas development. Specific conductance and sodium-adsorption ratios may be larger in coalbed waters than in stream waters that may receive the discharge waters. Therefore, continuous water-quality instruments for specific conductance were installed and discrete water-quality samples were collected to characterize water quality during water years 2001-2004 at four sites in the Powder River drainage basin: Powder River at Sussex, Wyoming; Crazy Woman Creek near Arvada, Wyoming; Clear Creek near Arvada, Wyoming; and Powder River at Moorhead, Montana. During water years 2001-2004, the median specific conductance of 2,270 microsiemens per centimeter at 25 degrees Celsius (?S/cm) in discrete samples from the Powder River at Sussex, Wyoming, was larger than the median specific conductance of 1,930 ?S/cm in discrete samples collected downstream from the Powder River at Moorhead, Montana. The median specific conductance was smallest in discrete samples from Clear Creek (1,180 ?S/cm), which has a dilution effect on the specific conductance for the Powder River at Moorhead, Montana. The daily mean specific conductance from continuous water-quality instruments during the irrigation season showed the same spatial pattern as specific conductance values for the discrete samples. Dissolved sodium, sodium-adsorption ratios, and dissolved solids generally showed the same spatial pattern as specific conductance. The largest median sodium concentration (274 milligrams per liter) and the largest range of sodium-adsorption ratios (3.7 to 21) were measured in discrete samples from the Powder River at Sussex, Wyoming. Median concentrations of sodium and sodium-adsorption ratios were substantially smaller in Crazy Woman Creek and Clear Creek, which tend to decrease sodium concentrations and sodium-adsorption ratios at the Powder River at Moorhead, Montana. Dissolved-solids concentrations in discrete samples were closely correlated with specific conductance values; Pearson's correlation coefficients were 0.98 or greater for all four sites. Regression equations for discrete values of specific conductance and sodium-adsorption ratios were statistically significant (p-values <0.001) at all four sites. The strongest relation (R2=0.92) was at the Powder River at Sussex, Wyoming. Relations on Crazy Woman Creek (R2=0.91) and Clear Creek (R2=0.83) also were strong. The relation between specific conductance and sodium-adsorption ratios was weakest (R2=0.65) at the Powder River at Moorhead, Montana; however, the relation was still significant. These data indicate that values of specific conductance are useful for estimating sodium-adsorption ratios. A regression model called LOADEST was used to estimate dissolved-solids loads for the four sites. The average daily mean dissolved-solids loads varied among the sites during water year 2004. The largest average daily mean dissolved-solids load was calculated for the Powder River at Moorhead, Montana. Although the smallest concentrations of dissolved solids were in samples from Clear Creek, the smallest average daily mean dissolved-solids load was calculated for Crazy Woman Creek. The largest loads occurred during spring runoff, and the smallest loads occurred in late summer, when streamflows typically were smallest. Dissolved-solids loads may be smaller than average during water years 2001-2004 because of smaller than average streamflow as a result of drought conditions.

Groundwater quality in the Santa Clara River Valley, California

USGS Publications Warehouse

Burton, Carmen A.; Landon, Matthew K.; Belitz, Kenneth

2011-01-01

The Santa Clara River Valley (SCRV) study unit is located in Los Angeles and Ventura Counties, California, and is bounded by the Santa Monica, San Gabriel, Topatopa, and Santa Ynez Mountains, and the Pacific Ocean. The 460-square-mile study unit includes eight groundwater basins: Ojai Valley, Upper Ojai Valley, Ventura River Valley, Santa Clara River Valley, Pleasant Valley, Arroyo Santa Rosa Valley, Las Posas Valley, and Simi Valley (California Department of Water Resources, 2003; Montrella and Belitz, 2009). The SCRV study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 12 to 28 inches. The study unit is drained by the Ventura and Santa Clara Rivers, and Calleguas Creek. The primary aquifer system in the Ventura River Valley, Ojai Valley, Upper Ojai Valley, and Simi Valley basins is largely unconfined alluvium. The primary aquifer system in the remaining groundwater basins mainly consists of unconfined sands and gravels in the upper portion and partially confined marine and nonmarine deposits in the lower portion. The primary aquifer system in the SCRV study unit is defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. Public-supply wells typically are completed in the primary aquifer system to depths of 200 to 1,100 feet below land surface (bls). The wells contain solid casing reaching from the land surface to a depth of about 60-700 feet, and are perforated below the solid casing to allow water into the well. Water quality in the primary aquifer system may differ from the water in the shallower and deeper parts of the aquifer. Land use in the study unit is approximately 40 percent (%) natural (primarily shrubs, grassland, and wetlands), 37% agricultural, and 23% urban. The primary crops are citrus, avocados, alfalfa, pasture, strawberries, and dry beans. The largest urban areas in the study unit are the cities of Ventura, Oxnard, Camarillo, Simi Valley, Newhall, and Santa Clarita. Currently, groundwater pumping for agricultural use accounts for the greatest amount of discharge from the aquifer system in the SCRV study unit, followed by municipal use. Recharge to the groundwater system is through stream-channel infiltration from the three main river systems and by direct infiltration of precipitation and irrigation. Recharge facilities in the Oxnard forebay play an important role in recharging the local aquifer systems.

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.

Integrated System of Structural Health Monitoring and Intelligent Management for a Cable-Stayed Bridge

PubMed Central

Chen, Bin; Wang, Xu; Sun, Dezhang; Xie, Xu

2014-01-01

It is essential to construct structural health monitoring systems for large important bridges. Zhijiang Bridge is a cable-stayed bridge that was built recently over the Hangzhou Qiantang River (the largest river in Zhejiang Province). The length of Zhijiang Bridge is 478 m, which comprises an arched twin-tower space and a twin-cable plane structure. As an example, the present study describes the integrated system of structural health monitoring and intelligent management for Zhijiang Bridge, which comprises an information acquisition system, data management system, evaluation and decision-making system, and application service system. The monitoring components include the working environment of the bridge and various factors that affect bridge safety, such as the stress and strain of the main bridge structure, vibration, cable force, temperature, and wind speed. In addition, the integrated system includes a forecasting and decision-making module for real-time online evaluation, which provides warnings and makes decisions based on the monitoring information. From this, the monitoring information, evaluation results, maintenance decisions, and warning information can be input simultaneously into the bridge monitoring center and traffic emergency center to share the monitoring data, thereby facilitating evaluations and decision making using the system. PMID:25140342

Integrated system of structural health monitoring and intelligent management for a cable-stayed bridge.

PubMed

Chen, Bin; Wang, Xu; Sun, Dezhang; Xie, Xu

2014-01-01

It is essential to construct structural health monitoring systems for large important bridges. Zhijiang Bridge is a cable-stayed bridge that was built recently over the Hangzhou Qiantang River (the largest river in Zhejiang Province). The length of Zhijiang Bridge is 478 m, which comprises an arched twin-tower space and a twin-cable plane structure. As an example, the present study describes the integrated system of structural health monitoring and intelligent management for Zhijiang Bridge, which comprises an information acquisition system, data management system, evaluation and decision-making system, and application service system. The monitoring components include the working environment of the bridge and various factors that affect bridge safety, such as the stress and strain of the main bridge structure, vibration, cable force, temperature, and wind speed. In addition, the integrated system includes a forecasting and decision-making module for real-time online evaluation, which provides warnings and makes decisions based on the monitoring information. From this, the monitoring information, evaluation results, maintenance decisions, and warning information can be input simultaneously into the bridge monitoring center and traffic emergency center to share the monitoring data, thereby facilitating evaluations and decision making using the system.

Export of microplastics from land to sea. A modelling approach.

PubMed

Siegfried, Max; Koelmans, Albert A; Besseling, Ellen; Kroeze, Carolien

2017-12-15

Quantifying the transport of plastic debris from river to sea is crucial for assessing the risks of plastic debris to human health and the environment. We present a global modelling approach to analyse the composition and quantity of point-source microplastic fluxes from European rivers to the sea. The model accounts for different types and sources of microplastics entering river systems via point sources. We combine information on these sources with information on sewage management and plastic retention during river transport for the largest European rivers. Sources of microplastics include personal care products, laundry, household dust and tyre and road wear particles (TRWP). Most of the modelled microplastics exported by rivers to seas are synthetic polymers from TRWP (42%) and plastic-based textiles abraded during laundry (29%). Smaller sources are synthetic polymers and plastic fibres in household dust (19%) and microbeads in personal care products (10%). Microplastic export differs largely among European rivers, as a result of differences in socio-economic development and technological status of sewage treatment facilities. About two-thirds of the microplastics modelled in this study flow into the Mediterranean and Black Sea. This can be explained by the relatively low microplastic removal efficiency of sewage treatment plants in the river basins draining into these two seas. Sewage treatment is generally more efficient in river basins draining into the North Sea, the Baltic Sea and the Atlantic Ocean. We use our model to explore future trends up to the year 2050. Our scenarios indicate that in the future river export of microplastics may increase in some river basins, but decrease in others. Remarkably, for many basins we calculate a reduction in river export of microplastics from point-sources, mainly due to an anticipated improvement in sewage treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Water resources of the Snake River watershed, east-central Minnesota

USGS Publications Warehouse

Lindholm, Gerald F.; Helgesen, J.O.; Broussard, W.L.; Ericson, D.W.

1974-01-01

The Snake River, which drains an area of about 1,030 square miles, originates in an extensive area of peat bogs in the northern part of the watershed. It flows southward across gently rolling glacial terrain in which the major relief is near the river. Near the southern boundary of the watershed, the Snake River turns eastward to its confluence with the St. Croix River. The northwest half of the watershed is heavily forested, whereas much of the southeast half has been cleared. The largest communities in the watershed, Mora and Pine City, had 1970 populations of 2,582 and 2,143, respectively.

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.

Thermal and hydrologic suitability of Lake Erie and its major tributaries for spawning of Asian carps

USGS Publications Warehouse

Kocovsky, Patrick M.; Chapman, Duane C.; McKenna, James E.

2012-01-01

Bighead carp Hypophthalmichthys nobilis, silver carp H. molitrix, and grass carp Ctenopharyngodon idella (hereafter Asian carps) have expanded throughout the Mississippi River basin and threaten to invade Lakes Michigan and Erie. Adult bighead carp and grass carp have been captured in Lake Erie, but self-sustaining populations probably do not exist. We examined thermal conditions within Lake Erie to determine if Asian carps would mature, and to estimate time of year when fish would reach spawning condition. We also examined whether thermal and hydrologic conditions in the largest tributaries to western and central Lake Erie were suitable for spawning of Asian carps. We used length of undammed river, predicted summer temperatures, and predicted water velocity during flood events to determine whether sufficient lengths of river are available for spawning of Asian carps. Most rivers we examined have at least 100 km of passable river and summer temperatures suitable (> 21 C) for rapid incubation of eggs of Asian carps. Predicted water velocity and temperature were sufficient to ensure that incubating eggs, which drift in the water column, would hatch before reaching Lake Erie for most flood events in most rivers if spawned far enough upstream. The Maumee, Sandusky, and Grand Rivers were predicted to be the most likely to support spawning of Asian carps. The Black, Huron, Portage, and Vermilion Rivers were predicted to be less suitable. The weight of the evidence suggests that the largest western and central Lake Erie tributaries are thermally and hydrologically suitable to support spawning of Asian carps.

Influence of Groundwater Hydraulic Gradient on Bank Storage Metrics.

PubMed

Welch, Chani; Harrington, Glenn A; Cook, Peter G

2015-01-01

The hydraulic gradient between aquifers and rivers is one of the most variable properties in a river/aquifer system. Detailed process understanding of bank storage under hydraulic gradients is obtained from a two-dimensional numerical model of a variably saturated aquifer slice perpendicular to a river. Exchange between the river and the aquifer occurs first at the interface with the unsaturated zone. The proportion of total water exchanged through the river bank compared to the river bed is a function of aquifer hydraulic conductivity, partial penetration, and hydraulic gradient. Total exchange may be estimated to within 50% using existing analytical solutions provided that unsaturated zone processes do not strongly influence exchange. Model-calculated bank storage is at a maximum when no hydraulic gradient is present and increases as the hydraulic conductivity increases. However, in the presence of a hydraulic gradient, the largest exchange flux or distance of penetration does not necessarily correspond to the highest hydraulic conductivity, as high hydraulic conductivity increases the components of exchange both into and out of an aquifer. Flood wave characteristics do not influence ambient groundwater discharge, and so in large floods, hydraulic gradients must be high to reduce the volume of bank storage. Practical measurement of bank storage metrics is problematic due to the limitations of available measurement technologies and the nested processes of exchange that occur at the river-aquifer interface. Proxies, such as time series concentration data in rivers and groundwater, require further development to be representative and quantitative. © 2014, National GroundWater Association.

Source apportionment of trace metals in river sediments: A comparison of three methods.

PubMed

Chen, Haiyang; Teng, Yanguo; Li, Jiao; Wu, Jin; Wang, Jinsheng

2016-04-01

Increasing trace metal pollution in river sediment poses a significant threat to watershed ecosystem health. Identifying potential sources of sediment metals and apportioning their contributions are of key importance for proposing prevention and control strategies of river pollution. In this study, three advanced multivariate receptor models, factor analysis with nonnegative constraints (FA-NNC), positive matrix factorization (PMF), and multivariate curve resolution weighted-alternating least-squares (MCR-WALS), were comparatively employed for source apportionment of trace metals in river sediments and applied to the Le'an River, a main tributary of Poyang Lake which is the largest freshwater lake in China. The pollution assessment with contamination factor and geoaccumulation index suggested that the river sediments in Le'an River were contaminated severely by trace metals due to human activities. With the three apportionment tools, similar source profiles of trace metals in sediments were extracted. Especially, the MCR-WALS and PMF models produced essentially the same results. Comparatively speaking, the weighted schemes might give better solutions than the unweighted FA-NNC because the uncertainty information of environmental data was considered by PMF and MCR-WALS. Anthropogenic sources were apportioned as the most important pollution sources influencing the sediment metals in Le'an River with contributions of about 90%. Among them, copper tailings occupied the largest contribution (38.4-42.2%), followed by mining wastewater (29.0-33.5%), and agricultural activities (18.2-18.7%). To protect the ecosystem of Le'an River and Poyang Lake, special attention should be paid to the discharges of mining wastewater and the leachates of copper tailing ponds in that region. Copyright © 2015 Elsevier Ltd. All rights reserved.

Response of small glaciers to climate change: runoff from glaciers of the Wind River range, Wyoming

NASA Astrophysics Data System (ADS)

Bliss, A. K.; Stamper, B.

2017-12-01

Runoff from glaciers affects downstream ecosystems by influencing the quantity, seasonality, and chemistry of the water. We describe the present state of glaciers in the Wind River range, Wyoming and consider how these glaciers will change in the future. Wind River glaciers have been losing mass in recent decades, as seen with geodetic techniques and by examining glacier morphology. Interestingly, the 2016/7 winter featured one of the largest snowfalls on record. Our primary focus is the Dinwoody Glacier ( 3 km^2, 3300-4000 m above sea level). We present data collected in mid-August 2017 including glacier ablation rates, snow line elevations, and streamflow. We compare measured glacier mass loss to streamflow at the glacier terminus and at a USGS stream gauge farther downstream. Using a hydrological model, we explore the fate of glacial runoff as it moves into downstream ecosystems and through ranchlands important to local people. The techniques used here can be applied to similar small-glacier systems in other parts of the world.

The Chemehuevi Indians of Southern California. Malki Museum Brochure No. 3.

ERIC Educational Resources Information Center

Miller, Ronald Dean; Miller, Peggy Jeanne

The only local tribe to migrate into California during recorded history, the Chemehuevi Indians had one of the largest tribal areas in California, though their population probably never exceeded 800. Today most live on the Colorado River Reservation, where they share membership with the Colorado River tribes. First mentioned in a priest's report…

More frequent flooding? Changes in flood frequency in the Pearl River basin, China, since 1951 and over the past 1000 years

NASA Astrophysics Data System (ADS)

Zhang, Qiang; Gu, Xihui; Singh, Vijay P.; Shi, Peijun; Sun, Peng

2018-05-01

Flood risks across the Pearl River basin, China, were evaluated using a peak flood flow dataset covering a period of 1951-2014 from 78 stations and historical flood records of the past 1000 years. The generalized extreme value (GEV) model and the kernel estimation method were used to evaluate frequencies and risks of hazardous flood events. Results indicated that (1) no abrupt changes or significant trends could be detected in peak flood flow series at most of the stations, and only 16 out of 78 stations exhibited significant peak flood flow changes with change points around 1990. Peak flood flow in the West River basin increased and significant increasing trends were identified during 1981-2010; decreasing peak flood flow was found in coastal regions and significant trends were observed during 1951-2014 and 1966-2014. (2) The largest three flood events were found to cluster in both space and time. Generally, basin-scale flood hazards can be expected in the West and North River basins. (3) The occurrence rate of floods increased in the middle Pearl River basin but decreased in the lower Pearl River basin. However, hazardous flood events were observed in the middle and lower Pearl River basin, and this is particularly true for the past 100 years. However, precipitation extremes were subject to moderate variations and human activities, such as building of levees, channelization of river systems, and rapid urbanization; these were the factors behind the amplification of floods in the middle and lower Pearl River basin, posing serious challenges for developing measures of mitigation of flood hazards in the lower Pearl River basin, particularly the Pearl River Delta (PRD) region.

Managing Floodplain Expectations on the Lower Missouri River, USA.

NASA Astrophysics Data System (ADS)

Bulliner, E. A., IV; Jacobson, R. B.; Lindner, G. A.; Paukert, C.; Bouska, K.

2017-12-01

The Missouri River is an archetype of the challenges of managing large rivers and their floodplains for multiple objectives. At 1.3 million km2 drainage area, the Missouri boasts the largest reservoir system in North America with 91 km3 of total storage; in an average year the system generates 10 billion kilowatt hours of electricity. The Lower Missouri River floodplain extends 1,300 km downstream from the reservoir system and encompasses approximately 9,200 km2. For the past 150 years, the floodplain has been predominantly used for agriculture much of which is protected from flooding by private and Federal levees. Reservoir system operating policies prioritize flood-hazard reduction but in recent years, large, damaging floods have demonstrated system limitations. These large floods and changing societal values have created new expectations about how conversion of floodplain agricultural lands to conservation lands might increase ecosystem services, in particular decreasing flood risk and mitigating fluxes of nutrients to the Gulf of Mexico. Our research addresses these expectations at multiple spatial scales by starting with hydrologic and hydraulic models to understand controls on floodplain hydrodynamics. The results document the substantial regional spatial variability in floodplain connectivity that exists because of multi-decadal channel adjustments to channelization and sediment budgets. Exploration of levee setback scenarios with 1- and 2-dimensional hydrodynamic models indicates modest and spatially variable gains in flood-hazard reduction are possible if substantial land areas (50% or more) are converted from agricultural production. Estimates of potential denitrification benefits of connecting floodplains indicate that the floodplain has the capacity to remove 100's to 1,000's of metric tons of N each year, but amounts to a maximum of about 5% the existing load of 200,000 ton*y-1. The results indicate that in this river-floodplain system, the ecosystem services associated with floodplain conversion can be substantial, but the sum of benefits needed to justify land conversion over broad areas remains uncertain.

Improving regional climate and hydrological forecasting following the record setting flooding across the Lake Ontario - St. Lawrence River system

NASA Astrophysics Data System (ADS)

Gronewold, A.; Seglenieks, F.; Bruxer, J.; Fortin, V.; Noel, J.

2017-12-01

In the spring of 2017, water levels across Lake Ontario and the upper St. Lawrence River exceeded record high levels, leading to widespread flooding, damage to property, and controversy over regional dam operating protocols. Only a few years earlier, water levels on Lakes Superior, Michigan, and Huron (upstream of Lake Ontario) had dropped to record low levels leading to speculation that either anthropogenic controls or climate change were leading to chronic water loss from the Great Lakes. The contrast between low water level conditions across Earth's largest lake system from the late 1990s through 2013, and the rapid rise prior to the flooding in early 2017, underscores the challenges of quantifying and forecasting hydrologic impacts of rising regional air and water temperatures (and associated changes in lake evaporation) and persistent increases in long-term precipitation. Here, we assess the hydrologic conditions leading to the recent record flooding across the Lake Ontario - St. Lawrence River system, with a particular emphasis on understanding the extent to which those conditions were consistent with observed and anticipated changes in historical and future climate, and the extent to which those conditions could have been anticipated through improvements in seasonal climate outlooks and hydrological forecasts.

River Mixing in the Amazon as a Driver of Concentration-Discharge Relationships

NASA Astrophysics Data System (ADS)

Bouchez, Julien; Moquet, Jean-Sébastien; Espinoza, Jhan Carlo; Martinez, Jean-Michel; Guyot, Jean-Loup; Lagane, Christelle; Filizola, Naziano; Noriega, Luis; Hidalgo Sanchez, Liz; Pombosa, Rodrigo

2017-11-01

Large hydrological systems aggregate compositionally different waters derived from a variety of pathways. In the case of continental-scale rivers, such aggregation occurs noticeably at confluences between tributaries. Here we explore how such aggregation can affect solute concentration-discharge (C-Q) relationships and thus obscure the message carried by these relationships in terms of weathering properties of the Critical Zone. We build up a simple model for tributary mixing to predict the behavior of C-Q relationships during aggregation. We test a set of predictions made in the context of the largest world's river, the Amazon. In particular, we predict that the C-Q relationships of the rivers draining heterogeneous catchments should be the most "dilutional" and should display the widest hysteresis loops. To check these predictions, we compute 10 day-periodicity time series of Q and major solute (Si, Ca2+, Mg2+, K+, Na+, Cl-, SO42-) C and fluxes (F) for 13 gauging stations located throughout the Amazon basin. In agreement with the model predictions, C-Q relationships of most solutes shift from a fairly "chemostatic" behavior (nearly constant C) at the Andean mountain front and in pure lowland areas, to more "dilutional" patterns (negative C-Q relationship) toward the system mouth. More prominent C-Q hysteresis loops are also observed at the most downstream stations. Altogether, this study suggests that mixing of water and solutes between different flowpaths exerts a strong control on C-Q relationships of large-scale hydrological systems.

The Columbia River--on the Leading Edge

NASA Astrophysics Data System (ADS)

O'Connor, J. E.

2005-05-01

On the leading edge of the North American plate, the Columbia River is the largest of the world's 40 or so rivers with drainage areas greater than 500,000 square kilometers to drain toward a convergent plate boundary. This unique setting results in a unique continental river basin; marked by episodic and cataclysmic geologic disturbance, but also famously fecund with perhaps 10 to 16 million salmon historically spawning in its waters each year. Now transformed by dams, transportation infrastructure, dikes and diversions, the Columbia River presents an expensive conundrum for management of its many values. Inclusion of river ecology and geomorphology in discussions of river management is generally limited to observations of the last 200 years-a time period of little natural disturbance and low sediment transport. However, consideration of longer timescales provides additional perspective of historical ecologic and geomorphic conditions. Only 230 km from its mouth, the Columbia River bisects the volcanic arc of the Cascade Range, forming the Columbia River Gorge. Cenozoic lava flows have blocked the river, forcing diversions and new canyon cutting. Holocene eruptions of Mount Mazama (Crater Lake), Mount Hood, Mount St. Helens, and Mount Rainier have shed immense quantities of sediment into the lower Columbia River, forming a large percentage of the Holocene sediment transported through the lower river. Quaternary landslides, perhaps triggered by great earthquakes, have descended from the 1000-m-high gorge walls, also blocking and diverting the river, one as recently as 550 years ago. These geologic disturbances, mostly outside the realm of historical observation and operating at timescales of 100s to 1000s of years in the gorge and elsewhere, have clearly affected basin geomorphology, riverine ecology, and past and present cultural utilization of river resources. The historic productivity of the river, however, hints at extraordinary resilience (and perhaps dependence) of the Columbia River system to such disturbances, many of which are similar to engineered disturbances of the last 200 years.

Mighty Microbes Where Rivers Run

ScienceCinema

Stegen, James

2018-01-16

Microbes and their influential role in Earth’s climate take center stage in the area where river water and groundwater mix – an area known as the hyporheic zone. PNNL ecologist James Stegen discusses his team’s research in his “laboratory” – the zone along the Columbia, one of the nation’s largest rivers. It’s a squishy, porous lab, better known for soaking feet than serving as the “river’s liver.”

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.

Contamination characteristics of organochlorine pesticides in multimatrix sampling of the Hanjiang River Basin, southeast China.

PubMed

Liu, Jia; Qi, Shihua; Yao, Jun; Yang, Dan; Xing, Xinli; Liu, Hongxia; Qu, Chengkai

2016-11-01

Hanjiang River, the second largest river in Guangdong Province, Southern China, is the primary source of drinking water for the cities of Chaozhou and Shantou. Our previous studies indicated that soils from an upstream catchment area of the Hanjiang River are moderately contaminated with organochlorine pesticides (OCPs), which can easily enter the river system via soil runoff. Therefore, OCPs, especially downstream drinking water sources, may pose harmful health and environmental risks. On the basis of this hypothesis, we measured the OCP concentrations in dissolved phase (DP), suspended particle matter (SPM), and surface sediment (SS) samples collected along the Hanjiang River Basin in Fujian and Guangdong provinces. OCP residue levels were quantified through electron capture detector gas chromatography to identify the OCP sources and deposits. The concentration ranges of OCPs in DP, SPM, and SS, respectively, were 2.11-12.04 (ng/L), 6.60-64.77 (ng/g), and 0.60-4.71 (ng/g) for hexachlorocyclohexanes (HCHs), and 2.49-4.77 (ng/L), 6.75-80.19 (ng/g), and 0.89-252.27 (ng/g) for dichloro-diphenyl-trichloroethanes (DDTs). Results revealed that DDTs represent an ecotoxicological risk to the Hanjiang River Basin, as indicated by international sediment guidelines. This study serves as a basis for the future management of OCP concentrations in the Hanjiang River Basin, and exemplifies a pattern of OCP movement (like OCP partition among multimedia) from upstream to downstream. This pattern may be observed in similar rivers in China. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sediment load from major rivers into Puget Sound and its adjacent waters

USGS Publications Warehouse

Czuba, Jonathan A.; Magirl, Christopher S.; Czuba, Christiana R.; Grossman, Eric E.; Curran, Christopher A.; Gendaszek, Andrew S.; Dinicola, Richard S.

2011-01-01

Each year, an estimated load of 6.5 million tons of sediment is transported by rivers to Puget Sound and its adjacent waters—enough to cover a football field to the height of six Space Needles. This estimated load is highly uncertain because sediment studies and available sediment-load data are sparse and historically limited to specific rivers, short time frames, and a narrow range of hydrologic conditions. The largest sediment loads are carried by rivers with glaciated volcanoes in their headwaters. Research suggests 70 percent of the sediment load delivered to Puget Sound is from rivers and 30 percent is from shoreline erosion, but the magnitude of specific contributions is highly uncertain. Most of a river's sediment load occurs during floods.

Estimating SGD flux in the Pingtung Plain coastal area by using Radon and Radium isotopes

NASA Astrophysics Data System (ADS)

Li Chang, Yao; Chieh Su, Chih

2015-04-01

In the past two decades, submarine groundwater discharge (SGD) has been recognized as an important pathway to transport material into coastal area. Our study area is located at Pingtung Plain which is the second largest plain in Taiwan with three major rivers, including Gaoping, Donggang and Linbian Rivers, flow through the plain. The Gaoping River, which has the largest drainage area, flows throughout the central part of the plain. The Pingtung Plain composed by four aquifers in different depths (0, 50, 100, and 200 m) and each layer extends to coastal area. Groundwater is an important water resource for local agriculture and aquaculture. However, the long-term over-pumping induced subsidence problem makes salinization at some coastal area. Some previous studies pointed out the SGD accounts for 80% or more of the mass of freshwater in Fangshan coast, depends on salinity and stable isotopes research. In this study, the radioactive tracers, Radon (222Rn, T1/2=3.8 d) and short-lived Ra isotopes (223Ra, T1/2=11.4 d & 224Ra, T1/2=3.6 d) are used in tracing SGD off the Pingtung Plain. During 2013 to 2014, the terrestrial water samples were collected from Gaoping, Donggang, Linbian Rivers and springs in different seasons. We also conducted two coastal waters cruises by using R/V Ocean Researcher 3 (OR3-1768 and 1799 cruises in May and September 2014). Continuous 222Rn was measured by RAD7 equipped with RAD-AQUA system and large volume (20 L) seawater samples were collected by CTD/Rosette water sampler with Niskin sterile bottles. Water samples were flow through Mn-fiber (flow rate < 1 LPM) to concentrate the Ra isotopes, and counted via RaDeCC system. In spatial variation, our result shows the excess 224Ra in the downstream of Gaoping River (2.39 dpm 100L-1) is higher than upstream (1.09 dpm 100L-1). It indicates the groundwater input may play an important role at the downstream of Gaoping River. For temporal variation, excess 224Ra in the Gaoping River are higher in wet season (May-August) than dry season (Nov-Feb). Furthermore, in some drainage area which groundwater recharged by shallow aquifer, the 222Rn and excess 224Ra will diluted by large rainfall in August. The analysis results from coastal waters shows the activities of radium isotopes in surface water are higher than bottom water. Compare with the data collected from Pingtung Plain, the radon and radium isotopes activities are also higher in wet season (OR3-1799 in Sep 2014). The highest excess 224Ra value (2.90 dpm 100L-1) is located at the offshore of Linbian River and it is much higher than the value in the Linbian River (0.54 dpm 100L-1, salinity 0.2) which collected in August 2014.

Transport and fate of river waters under flood conditions and rim current influence: the Mississippi River test case

NASA Astrophysics Data System (ADS)

Kourafalou, Villy; Androulidakis, Yannis

2013-04-01

Large river plumes are a major supplier of freshwater, sediments and nutrients in coastal and shelf seas. Novel processes controlling the transport and fate of riverine waters (and associated materials) will be presented, under flood conditions and in the presence of complex topography, ambient shelf circulation and slope processes, controlled by the interaction with rim currents. The Mississippi River (MR) freshwater outflow is chosen as a test case, as a major circulation forcing mechanism for the Northern Gulf of Mexico and a unique river plume for the intense interactions with a large scale ocean current, namely the Loop Current branch of the Gulf Stream, and associated eddy field. The largest MR outflow in history (45,000 m3/sec in 2011) is compared with the second largest outflow in the last 8 years (41,000 m3/sec in 2008). Realistically forced simulations, based on the Hybrid Coordinate Ocean Model (HYCOM) with careful treatment of river plume dynamics and nested to a data assimilated, basin-wide model, reveal the synergistic effect of enhanced discharge, winds, stratification of ambient shelf waters and offshore circulation over the transport of plume waters. The investigation targets a broader understanding of the dynamics of large scale river plumes in general, and of the MR plume in particular. In addition, in situ observations from ship surveys and satellite chl-a data showed that the mathematical simulations with high temporal resolution river outflow input may reproduce adequately the buoyant waters spreading over the Northern Gulf of Mexico shelf and offshore areas. The fate of the river plume is strongly determined and affected by deep basin processes. The strong impacts of the Loop Current system (and its frontal eddies) on river plume evolution are of particular importance under conditions of increased offshore spreading, which is presumed under large discharge rates and can cause loss of riverine materials to the basin interior. Flood conditions can increase both downstream (westward) and upstream (eastward) spreading. The high outflow rates enhance the anticyclonic bulge, strengthen the downstream coastal current toward the western Louisiana-Texas shelf. The substantial eastward spreading over the eastern Mississippi-Alabama-Florida shelf was highly correlated with the Loop Current northward extension. On the contrary, cyclonic eddies east of the Delta effectively block the offshore eastward spreading of the plume and may keep the river waters away from the eastern shelf. We show that the proximity of eddies to the shelf break is a sufficient condition for shelf-to-offshore interaction, which is facilitated by the steep bottom topography near the Delta.

Nile River, Lake Nasser, Aswan High Dam, Egypt, Africa

NASA Technical Reports Server (NTRS)

1992-01-01

Lake Nasser, (24.0N, 33.0E) at the Aswan High Dam on the Nile River, in Egypt is the world's second largest artificial lake, extending 500 km, in length and about 5000 sq. km. in area. The lake has a storage capacity sufficient to irrigate farms in Egypt and Sudan year round allowing up to three harvests per year. Other benefits include year round river navagation, hydroelectric power, more fish harvests, reduced flooding and more industrial employment. opportunites.

Body size drives allochthony in food webs of tropical rivers.

PubMed

Jardine, Timothy D; Rayner, Thomas S; Pettit, Neil E; Valdez, Dominic; Ward, Douglas P; Lindner, Garry; Douglas, Michael M; Bunn, Stuart E

2017-02-01

Food web subsidies from external sources ("allochthony") can support rich biological diversity and high secondary and tertiary production in aquatic systems, even those with low rates of primary production. However, animals vary in their degree of dependence on these subsidies. We examined dietary sources for aquatic animals restricted to refugial habitats (waterholes) during the dry season in Australia's wet-dry tropics, and show that allochthony is strongly size dependent. While small-bodied fishes and invertebrates derived a large proportion of their diet from autochthonous sources within the waterhole (phytoplankton, periphyton, or macrophytes), larger animals, including predatory fishes and crocodiles, demonstrated allochthony from seasonally inundated floodplains, coastal zones or the surrounding savanna. Autochthony declined roughly 10% for each order of magnitude increase in body size. The largest animals in the food web, estuarine crocodiles (Crocodylus porosus), derived ~80% of their diet from allochthonous sources. Allochthony enables crocodiles and large predatory fish to achieve high biomass, countering empirically derived expectations for negative density vs. body size relationships. These results highlight the strong degree of connectivity that exists between rivers and their floodplains in systems largely unaffected by river regulation or dams and levees, and how large iconic predators could be disproportionately affected by these human activities.

iss047e137096

NASA Image and Video Library

2016-05-31

ISS047e137096 (06/03/2016) --- This stunning Earth image taken from the International Space Station looks from Northwestern China on the bottom into eastern Kazakhstan. The large lake in Kazakhstan with golden sun glint is named Lake Balkhash. It is one of the largest lakes in Asia and is the 15th largest lake in the world. The lake is fed by 7 rivers.

Water-Quality Characteristics for Sites in the Tongue, Powder, Cheyenne, and Belle Fourche River Drainage Basins, Wyoming and Montana, Water Years 2001-05, with Temporal Patterns of Selected Long-Term Water-Quality Data

USGS Publications Warehouse

Clark, Melanie L.; Mason, Jon P.

2007-01-01

Water-quality sampling was conducted regularly at stream sites within or near the Powder River structural basin in northeastern Wyoming and southeastern Montana during water years 2001-05 (October 1, 2000, to September 30, 2005) to characterize water quality in an area of coalbed natural gas development. The U.S. Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, characterized the water quality at 22 sampling sites in the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins. Data for general hydrology, field measurements, major-ion chemistry, and selected trace elements were summarized, and specific conductance and sodium-adsorption ratios were evaluated for relations with streamflow and seasonal variability. Trend analysis for water years 1991-2005 was conducted for selected sites and constituents to assess change through time. Average annual runoff was highly variable among the stream sites. Generally, streams that have headwaters in the Bighorn Mountains had more runoff as a result of higher average annual precipitation than streams that have headwaters in the plains. The Powder River at Moorhead, Mont., had the largest average annual runoff (319,000 acre-feet) of all the sites; however, streams in the Tongue River drainage basin had the highest runoff per unit area of the four major drainage basins. Annual runoff in all major drainage basins was less than average during 2001-05 because of drought conditions. Consequently, water-quality samples collected during the study period may not represent long-term water-quality con-ditions for all sites. Water-quality characteristics were highly variable generally because of streamflow variability, geologic controls, and potential land-use effects. The range of median specific-conductance values among sites was smallest in the Tongue River drainage basin. Median values in that basin ranged from 643 microsiemens per centimeter at 25 degrees Celsius (?S/cm at 25?C) on the Tongue River to 1,460 ?S/cm at 25?C on Prairie Dog Creek. The Tongue River drainage basin has the largest percentage of area underlain by Mesozoic-age and older rocks and by more resistant rocks. In addition, the higher annual precipitation and a steeper gradient in this basin compared to basins in the plains produce relatively fast stream velocities, which result in a short contact time between stream waters and basin materials. The Powder River drainage basin, which has the largest drainage area and most diverse site conditions, had the largest range of median specific-conductance values among the four major drainage basins. Median values in that basin ranged from 680 ?S/cm at 25?C on Clear Creek to 5,950 ?S/cm at 25?C on Salt Creek. Median specific-conductance values among sites in the Cheyenne River drainage basin ranged from 1,850 ?S/cm at 25?C on Black Thunder Creek to 4,680 ?S/cm at 25?C on the Cheyenne River. The entire Cheyenne River drainage basin is in the plains, which have low precipitation, soluble geologic materials, and relatively low gradients that produce slow stream velocities and long contact times. Median specific-conductance values among sites in the Belle Fourche River drainage basin ranged from 1,740 ?S/cm at 25?C on Caballo Creek to 2,800 ?S/cm at 25?C on Donkey Creek. Water in the study area ranged from a magnesium-calcium-bicarbonate type for some sites in the Tongue River drainage basin to a sodium-sulfate type at many sites in the Powder, Cheyenne, and Belle Fourche River drainage basins. Little Goose Creek, Goose Creek, and the Tongue River in the Tongue River drainage basin, and Clear Creek in the Powder River drainage basin, which have headwaters in the Bighorn Mountains, consistently had the smallest median dissolved-sodium concentrations, sodium-adsorption ratios, dissolved-sulfate concentrations, and dissolved-solids concentrations. Salt Creek, Wild Horse Creek, Little Powder River, and the Cheyenne River, which have headwat

Improving Simulations of Extreme Flows by Coupling a Physically-based Hydrologic Model with a Machine Learning Model

NASA Astrophysics Data System (ADS)

Mohammed, K.; Islam, A. S.; Khan, M. J. U.; Das, M. K.

2017-12-01

With the large number of hydrologic models presently available along with the global weather and geographic datasets, streamflows of almost any river in the world can be easily modeled. And if a reasonable amount of observed data from that river is available, then simulations of high accuracy can sometimes be performed after calibrating the model parameters against those observed data through inverse modeling. Although such calibrated models can succeed in simulating the general trend or mean of the observed flows very well, more often than not they fail to adequately simulate the extreme flows. This causes difficulty in tasks such as generating reliable projections of future changes in extreme flows due to climate change, which is obviously an important task due to floods and droughts being closely connected to people's lives and livelihoods. We propose an approach where the outputs of a physically-based hydrologic model are used as an input to a machine learning model to try and better simulate the extreme flows. To demonstrate this offline-coupling approach, the Soil and Water Assessment Tool (SWAT) was selected as the physically-based hydrologic model, the Artificial Neural Network (ANN) as the machine learning model and the Ganges-Brahmaputra-Meghna (GBM) river system as the study area. The GBM river system, located in South Asia, is the third largest in the world in terms of freshwater generated and forms the largest delta in the world. The flows of the GBM rivers were simulated separately in order to test the performance of this proposed approach in accurately simulating the extreme flows generated by different basins that vary in size, climate, hydrology and anthropogenic intervention on stream networks. Results show that by post-processing the simulated flows of the SWAT models with ANN models, simulations of extreme flows can be significantly improved. The mean absolute errors in simulating annual maximum/minimum daily flows were minimized from 4967 cusecs to 1294 cusecs for Ganges, from 5695 cusecs to 2115 cusecs for Brahmaputra and from 689 cusecs to 321 cusecs for Meghna. Using this approach, simulations of hydrologic variables other than streamflow can also be improved given that a decent amount of observed data for that variable is available.

Sediment Transport Capacity and Channel Processes in a Humid Tropical Montane River - Rio Pacuare, Costa Rica

NASA Astrophysics Data System (ADS)

Lind, P.; McDowell, P. F.

2017-12-01

Investigating sediment transport capacity as well as the spatial and temporal variations of sediment flux are critical component of river research, especially for applications in resource management and conservation, hazards assessment and planning, and riverine ecology. The bedload fraction of sediment transported through montane rivers often defines channel and bed form processes. It is understood that humid tropical montane rivers are capable of producing some of the largest quantities of sediment per unit drainage area. Bedload flux reported on a few Southeast Asian humid tropical montane rivers show that bedload constituted 16-75% of the total sediment load - this is notably higher than the generally accepted 10% of a channel's sediment load. However, to date almost all of the research done on sediment transport in humid tropical systems has focused on suspended load. This study presents annual bedload transport rate estimates for six field sites distributed within 45 river kilometers (Rkm) of the montane portion of the Rio Pacuare, located in the Talamanca Mountains of Costa Rica. This research reveals that flows capable of mobilizing the D84 occur on average at least once but often multiple times a year in this river system. The Rio Pacuare has a sufficient supply of sediment to meet its high transport capacity needs. As a result, large active bars composed of imbricated boulders define channel form at moderate and low flows throughout the study area. Differences in the magnitude, as well as the spatial and temporal variations of sediment flux at each field site are discussed in relation to stream power, and annual/inter-annual precipitation patterns. A unique mix of field and remote sensing techniques were applied to address these questions and to overcome some of the challenges of tropical river research. For example, due to the large grain size and high stream energy, grain mobilization and validation of modeled shear stress requirements for transport were made through high-resolution repeat photogrammetric surveys (Structure From Motion). As some of the first research of this type on a steep tropical montane system, this study expands our knowledge of tropical rivers and sediment transport by providing a broad view of bedload sediment flux in a hydrologically dynamic humid tropical montane system.

Concentrations, and estimated loads and yields of nutrients and suspended sediment in the Little River basin, Kentucky, 2003-04

USGS Publications Warehouse

Crain, Angela S.

2006-01-01

Nutrients, primarily nitrogen and phosphorus compounds, naturally occur but also are applied to land in the form of commercial fertilizers and livestock waste to enhance plant growth. Concentrations, estimated loads and yields, and sources of nitrite plus nitrate, total phosphorus, and orthophosphate were evaluated in streams of the Little River Basin to assist the Commonwealth of Kentucky in developing 'total maximum daily loads' (TMDLs) for streams in the basin. The Little River Basin encompasses about 600 square miles in Christian and Trigg Counties, and a portion of Caldwell County in western Kentucky. Water samples were collected in streams in the Little River Basin during 2003-04 as part of a study conducted in cooperation with the Kentucky Department of Agriculture. A total of 92 water samples were collected at four fixed-network sites from March through November 2003 and from February through November 2004. An additional 20 samples were collected at five synoptic-network sites during the same period. Median concentrations of nitrogen, phosphorus, and suspended sediment varied spatially and seasonally. Concentrations of nitrogen were higher in the spring (March-May) after fertilizer application and runoff. The highest concentration of nitrite plus nitrate-5.7 milligrams per liter (mg/L)-was detected at the South Fork Little River site. The Sinking Fork near Cadiz site had the highest median concentration of nitrite plus nitrate (4.6 mg/L). The North Fork Little River site and the Little River near Cadiz site had higher concentrations of orthophosphate in the fall and lower concentrations in the spring. Concentrations of orthophosphate remained high during the summer (June-August) at the North Fork Little River site possibly because of the contribution of wastewater effluent to streamflow. Fifty-eight percent of the concentrations of total phosphorus at the nine sites exceeded the U.S. Environmental Protection Agency recommended maximum concentration limit of 0.1 mg/L. Concentrations of suspended sediment were highest in the spring during runoff and lowest in the fall. The highest concentration of suspended sediment (1,020 mg/L) was observed at the Sinking Fork near Cadiz site. The median concentration of suspended sediment for all sites sampled was 12 mg/L. A nonparameteric statistical test (Wilcoxson rank-sum) showed that the median concentrations of suspended sediment were not different among any of the fixed-network sites. The Little River near Cadiz site contributed larger estimated mean annual loads of nitrite plus nitrate (2,500,000 pounds per year (lb/yr)) and total phosphorus (160,000 lb/yr) than the other three fixed-network sites. Of the two main upstream tributaries from the Little River near Cadiz site, the North Fork Little River was the greatest contributor of total phosphorus to the study area with an estimated mean annual load of 107,000 lb/yr or about 64 percent of the total estimated mean annual load at the Little River near Cadiz site. The other main upstream tributary, South Fork Little River, had an estimated mean annual load of total phosphorus that was about 20 percent of the mean annual load at the Little River near Cadiz site. Estimated loads of suspended sediment were largest at the Little River near Cadiz site, where the estimated mean annual load for 2003-04 was about 84,000,000 lb/yr. The North Fork Little River contributed an estimated 36 percent of the mean annual load of suspended sediment at the Little River near Cadiz site, while the South Fork Little River contributed an estimated 18 percent of the mean annual load at the Little River near Cadiz site. The North Fork Little River site had the largest estimated mean annual yield of total phosphorus (1,600 pounds per year per square mile (lb/yr/mi2)) and orthophosphate (1,100 lb/yr/mi2). A principal source of phosphorus for the North Fork Little River is discharge from wastewater-treatment facilities. The largest estimated mean annual yield of nitrite plus nitrate was observed at the South Fork Little River site. The North Fork Little River site had the largest estimated mean annual yield of suspended sediment (450,000 lb/yr/mi2). Inputs of nitrogen and phosphorus to streams from point and nonpoint sources were estimated for the Little River Basin. Commercial fertilizer and livestock-waste applications on row crops are a principal source of nutrients for most of the Little River Basin. Sources of nutrients in the urban areas of the basin mainly are from effluent discharge from wastewater-treatment facilities and fertilizer applications to lawns and golf courses.

Earth Observations by the Expedition 19 crew

NASA Image and Video Library

2009-04-15

ISS019-E-007720 (15 April 2009) --- Three Gorges Dam in China is featured in this image photographed by an Expedition 19 crew member on the International Space Station. A new reservoir is filling in central China. The Three Gorges Dam on the Yangtze River - the world?s largest dam ? was completed in 2006, and the river is filling up its valley behind the dam to form a narrow reservoir extending more than 600 kilometers. This image is one of the first images documenting the flooding behind the dam. The main objective for the dam is to supply water for the largest hydroelectric plant in the world and help control the devastating floods that plague the lowlands downstream from the dam.

Floods of July 23-26, 2010, in the Little Maquoketa River and Maquoketa River Basins, Northeast Iowa

USGS Publications Warehouse

Eash, David A.

2012-01-01

Minor flooding occurred July 23, 2010, in the Little Maquoketa River Basin and major flooding occurred July 23–26, 2010, in the Maquoketa River Basin in northeast Iowa following severe thunderstorm activity over the region during July 22–24. A breach of the Lake Delhi Dam on July 24 aggravated flooding on the Maquoketa River. Rain gages at Manchester and Strawberry Point, Iowa, recorded 72-hour-rainfall amounts of 7.33 and 12.23 inches, respectively, on July 24. The majority of the rainfall occurred during a 48-hour period. Within the Little Maquoketa River Basin, a peak-discharge estimate of 19,000 cubic feet per second (annual flood-probability estimate of 4 to 10 percent) at the discontinued 05414500 Little Maquoketa River near Durango, Iowa streamgage on July 23 is the sixth largest flood on record. Within the Maquoketa River Basin, peak discharges of 26,600 cubic feet per second (annual flood-probability estimate of 0.2 to 1 percent) at the 05416900 Maquoketa River at Manchester, Iowa streamgage on July 24, and of 25,000 cubic feet per second (annual flood-probability estimate of 1 to 2 percent) at the 05418400 North Fork Maquoketa River near Fulton, Iowa streamgage on July 24 are the largest floods on record for these sites. A peak discharge affected by the Lake Delhi Dam breach on July 24 at the 05418500 Maquoketa River near Maquoketa, Iowa streamgage, located downstream of Lake Delhi, of 46,000 cubic feet per second on July 26 is the third highest on record. High-water marks were measured at five locations along the Little Maquoketa and North Fork Little Maquoketa Rivers between U.S. Highway 52 near Dubuque and County Road Y21 near Rickardsville, a distance of 19 river miles. Highwater marks were measured at 28 locations along the Maquoketa River between U.S. Highway 52 near Green Island and State Highway 187 near Arlington, a distance of 142 river miles. High-water marks were measured at 13 locations along the North Fork Maquoketa River between Rockdale Road near Maquoketa and U.S. Highway 52 near Luxemburg, a distance of 90 river miles. The high-water marks were used to develop flood profiles for the Little Maquoketa, North Fork Little Maquoketa, Maquoketa, and North Fork Maquoketa Rivers.

Transport of dissolved carbon and CO2 degassing from a river system in a mixed silicate and carbonate catchment

NASA Astrophysics Data System (ADS)

Khadka, Mitra B.; Martin, Jonathan B.; Jin, Jin

2014-05-01

Assessing the origin, transformation and transport of terrestrially derived carbon in river systems is critical to regional and global carbon cycles, particularly in carbonate terrains, which represent the largest carbon reservoir on the earth’s surface. For this reason, we evaluated sources, cycling, and fluxes of dissolved organic and inorganic carbon (DOC and DIC) and riverine CO2 degassing to the atmosphere in the Santa Fe River in north-central Florida, a sub-tropical river that flows across two distinct hydrogeological settings of a region dominated by carbonate karst. One setting occurs in the upper river catchment, where the carbonate Floridan aquifer is confined by the siliciclastic Hawthorn Group, while the other setting occurs in the lower catchment where the river flows across the unconfined Floridan aquifer. The upper catchment is characterized by DOC-rich and DIC-poor water and the DIC has more variable and lower δ13C values compared to the lower catchment. The river in the upper catchment degasses more CO2 to the atmosphere (1156 g C m-2 yr-1) than in the lower catchment (402 g C m-2 yr-1) because soil respired carbon and organic matter decomposition increase dissolved CO2 concentration, much of which is consumed during carbonate dissolution reactions in the lower catchment. The CO2 flux from the water surface to the atmosphere during a flood event is three times greater than during base flow, suggesting that excess precipitation flushes soil organic carbon to the river through interflow and enhances the loss of terrestrial carbon via river water to the atmosphere. Our values of CO2 fluxes to the atmosphere lie within the range of fluxes from the world’s rivers, but fluxes from the carbonate dominated region are at the low end, while fluxes from the siliciclastic region are at the high end. These results indicate that catchment lithologies, particularly whether carbonate or siliciclastic, as well as flow, are critical to carbon budgets in rivers and thus are linked to the global carbon cycle.

Diet composition and fish consumption of double-crested cormorants from three St. Lawrence River Colonies in 2013

USGS Publications Warehouse

Johnson, James H.; Farquhar, James F.; Mazzocchi, Irene M.; Bendig, Anne

2014-01-01

Double-crested Cormorants (Phalacrocorax auritus) were first observed nesting in the upper St. Lawrence River at Strachan Island in 1992. Cormorants now nest at a number of islands in the Thousand Islands section of the river. Griswold, McNair, and Strachan islands are among the largest colonies in the upper river. Until 2011, nest counts had remained relatively stable, ranging from 200 to 603 nests per colony. However, since 2011 the number of nests at McNair Island have exceeded 700 each year. Although the size of cormorant colonies in the upper St. Lawrence River is smaller than those in the eastern basin of Lake Ontario, the close proximity of islands in the upper river that have colonies may cause a cumulative fish consumption effect similar to a larger colony. Because of increasing numbers of Double-crested Cormorants in the upper St. Lawrence River and the possible effects on fish populations, studies were initiated in 1999 to quantify cormorant diet and fish consumption at the three largest colonies. From 1999 to 2012, these studies have shown that cormorants consumed about 128.6 million fish including 37.5 million yellow perch (Perca flavescens), 17.4 million rock bass (Ambloplites rupestris) and 1.0 million smallmouth bass (Micropterus dolemieu) (Johnson et al. 2012). During this same time period fish assessment studies near some of these islands have shown a major decrease in yellow perch populations (Klindt 2007). This occurrence is known as the halo effect and happens when piscivorous birds deplete local fish populations in areas immediately surrounding the colony (Ashmole 1963). This paper describes the diet and fish consumption of cormorants in the upper St. Lawrence River in 2013.

Tectonic controls on the morphodynamics of the Brahmaputra River system in the upper Assam valley, India

NASA Astrophysics Data System (ADS)

Lahiri, Siddhartha K.; Sinha, Rajiv

2012-10-01

The Brahmaputra is one of the largest tropical rivers of the world and is located in an area of high structural instability as evidenced from the presence of a large number of earthquakes in the Himalayan catchment through which it flows. Syntectonic evidence of changes in the morphodynamics is difficult to identify for the large rivers. Nevertheless, we note that the Brahmaputra River has become astonishingly large in planform in a historical timescale. Reconstruction of planform changes over a period of 90 years in the upper reaches of the Assam valley shows that the 240-km-long channel belt is widening all along its course in the region. From the average width of 9.74 km in 1915, the channel belt has widened to the average width of 14.03 km in 2005 (44% widening), and in certain reaches the average widening is as high as 250%. However, the bank line shift is not symmetric along both banks. Further, the planform characteristics of the Brahmaputra River reveal significant spatial and temporal variability from upstream to downstream reaches, and we attribute this variability to tectonogeomorphic zonation of the river based on subsurface configuration and channel slope. Further, the tributaries joining the northern and southern banks of the Brahmaputra differ remarkably in terms of river dynamics, and this is attributed to the differences in tectonic regimes of the Himalaya in the north and the Naga Patkai hills in the south.

Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA

USGS Publications Warehouse

Fenton, C.R.; Webb, R.H.; Cerling, T.E.

2006-01-01

The failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366 m high, and geochemical evidence linked this structure to outburst-flood deposits that occurred for 32 km downstream. Using the Hyaloclastite outburst-flood deposits as paleostage indicators, we used dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. Failure of the Hyaloclastite Dam released a maximum 11 ?? 109 m3 of water in 31 h. Peak discharges, estimated from uncertainty in channel geometry, dam height, and hydraulic characteristics, ranged from 2.3 to 5.3 ?? 105 m3 s-1 for the Hyaloclastite outburst flood. This discharge is an order of magnitude greater than the largest known discharge on the Colorado River (1.4 ?? 104 m3 s-1) and the largest peak discharge resulting from failure of a constructed dam in the USA (6.5 ?? 104 m3 s-1). Moreover, the Hyaloclastite outburst flood is the oldest documented Quaternary flood and one of the largest to have occurred in the continental USA. The peak discharge for this flood ranks in the top 30 floods (>105 m3 s-1) known worldwide and in the top ten largest floods in North America. ?? 2005 University of Washington. All rights reserved.

Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA

NASA Astrophysics Data System (ADS)

Fenton, Cassandra R.; Webb, Robert H.; Cerling, Thure E.

2006-03-01

The failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366 m high, and geochemical evidence linked this structure to outburst-flood deposits that occurred for 32 km downstream. Using the Hyaloclastite outburst-flood deposits as paleostage indicators, we used dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. Failure of the Hyaloclastite Dam released a maximum 11 × 10 9 m 3 of water in 31 h. Peak discharges, estimated from uncertainty in channel geometry, dam height, and hydraulic characteristics, ranged from 2.3 to 5.3 × 10 5 m 3 s -1 for the Hyaloclastite outburst flood. This discharge is an order of magnitude greater than the largest known discharge on the Colorado River (1.4 × 10 4 m 3 s -1) and the largest peak discharge resulting from failure of a constructed dam in the USA (6.5 × 10 4 m 3 s -1). Moreover, the Hyaloclastite outburst flood is the oldest documented Quaternary flood and one of the largest to have occurred in the continental USA. The peak discharge for this flood ranks in the top 30 floods (>10 5 m 3 s -1) known worldwide and in the top ten largest floods in North America.

Soil properties of mangroves in contrasting geomorphic settings within the Zambezi River Delta, Mozambique

Treesearch

Christina E. Stringer; Carl C. Trettin; Stan Zarnoch

2016-01-01

Mangroves are well-known for their numerous ecosystem services, including sequestering a significant carbon stock, with soils accounting for the largest pool. The soil carbon pool is dependent on the carbon content and bulk density. Our objective was to assess the spatial variability of mangrove soil physical and chemical properties within the Zambezi River Delta and...

CNA Maritime Asia Project. Workshop One: The Yellow and East China Seas

DTIC Science & Technology

2012-05-01

TEU) were all in the world’s top 25 ports.2 Shanghai, positioned at the crossroads of the Yellow Sea, East China Sea, and Yangtze River, is the...Sea, and Yangtze River, is the largest port in the world, shipping over 29 million TEU in 2011.4 Nearly 57% of China’s total trade volume emanates

Biological and associated water-quality data for lower Olmos Creek and upper San Antonio River, San Antonio, Texas, April - September 1989

USGS Publications Warehouse

Taylor, R. Lynn; Ferreira, Rodger F.

1995-01-01

Biological and associated water-quality data were collected from lower Olmos Creek and upper San Antonio River in San Antonio, Texas, during April-September 1989. Benthic macroinvertebrate, periphyton, and phytoplankton communities were sampled at three sites along the Olmos Creek/San Antonio River system. Total mean densities of benthic macroinvertebrates for the three sites ranged from 670 to 10,000 organisms per square meter. The most abundant macroinvertebrates were the class Insecta (insects). Total densities of periphyton ranged from 2,900 to 110,000 cells per square millimeter. Cyanophyta (blue-green algae) and Bacillariophyta (diatoms) were the predominant periphyton organisms. Total densities of phyto- plankton ranged from 5,000 to 47,000 cells per square milliliter. Blue-green algae accounted for more than one- half of the phytoplankton in each sample. Hardness ranged from 160 to 250 milligrams per liter as calcium carbonate, and alkalinity ranged from 130 to 220 milligrams per liter as calcium carbonate. The largest dissolved nitrite concentration was 0.038 milligram per liter. The largest total phosphorus concentration was 0.150 milligram per liter, over one-half of which was dissolved orthophosphate. Total aluminum and total iron were the only trace elements in water to exceed the reporting threshold by large concen- trations. Total aluminum concentrations ranged from 70 to 280 micrograms per liter, and total iron concentrations ranged from 70 to 340 micrograms per liter. Lead was the most prominent trace element in bottom-material samples, with concentrations ranging from 30 to 230 micrograms per gram.

Suggestions on water sources protection for the Gan River of Jiangxi, People's Republic of China

NASA Astrophysics Data System (ADS)

Fu, C.; Jiang, Z.

2007-05-01

The Gan River is the largest river in Jiangxi Province, which is located in the southeast of China and is the second branch of the Yangtze River. The Gan River flows through Jiangxi Province from the South to the North and plays an important role in the economic development for 14 counties or cities with a population of 22 million. Currently, there are 5 drinking water sources, such as the capital city, Nanchang, with a daily capacity of 0.72 million cubic meters. With the rapid economic development and increasing population in the Gan River basin, water pollution has become more serious. The water quality of the river has serious pollution on both side reaches and slight pollution on the middle reach. In the upstream, the main pollution problems come from the industrial wastewater and soil erosion, with industrial and sewage wastewater affecitng the downstream region. Based on the Provincial Environmental Quality Report of 2005, of 39 monitoring sections, the ones which reach a favorable rating of a National Standard are 71.8 per cent. The water quality in the upstream region had a good situation with 80 percent of locations meeting standards, but the water quality downstream of the capital city deteriorates and only 45.4 percent of this region can meet the standard. Standards are frequently exceeded for BOD5, TP, TN, fecal coliform, and petrolueum oil in the downstream portion. The industrial wastewater drained into the river was 139 million tons in 2005, of which Nanchang city is the largest contributor with 214 million tons of wastewater composed of 75 million tons of industrial wastewater and 139 million tons of domestic sewage. The largest COD contributor was from Ganzhou in the upstream of the river with a total of 83,800 tons in 2005. Currently, there are only two wastewater treatment facilities with daily treatment capacity of 402,000 tons along the river, which are located in the capital city. Some parameters in the treated water stil exceed the drainage standard. Based on the characteristic of soil erosion in the mountain areas in the upstream portion of the Gan River, Jiangxi Province has carried out a strategy of comprehensive treatment of small river basins since 1983. A total of 374 small basins in Ganzhou city have been treated and 0.5 million hectare of soil erosion area have been treated which is 78.2 percent of the whole soil erosion in this region. Some suggestions on protection of water sources have been proposed as: to continue the comprehensive treatment of soil erosion, to enhance the treatment capacity of domestic sewage, to optimize the treatment technology and control sewage in the cities along the river, to formulate a plan for the basin water resources utilization, and to enhance the performance capacity of environmental protection laws and regulations.

Linkage between Three Gorges Dam impacts and the dramatic recessions in China’s largest freshwater lake, Poyang Lake

PubMed Central

Mei, Xuefei; Dai, Zhijun; Du, Jinzhou; Chen, Jiyu

2015-01-01

Despite comprising a small portion of the earth’s surface, lakes are vitally important for global ecosystem cycling. However, lake systems worldwide are extremely fragile, and many are shrinking due to changing climate and anthropogenic activities. Here, we show that Poyang Lake, the largest freshwater lake in China, has experienced a dramatic and prolonged recession, which began in late September of 2003. We further demonstrate that abnormally low levels appear during October, 28 days ahead of the normal initiation of the dry season, which greatly imperiled the lake’s wetland areas and function as an ecosystem for wintering waterbirds. An increase in the river-lake water level gradient induced by the Three Gorges Dam (TGD) altered the lake balance by inducing greater discharge into the Changjiang River, which is probably responsible for the current lake shrinkage. Occasional episodes of arid climate, as well as local sand mining, will aggravate the lake recession crisis. Although impacts of TGD on the Poyang Lake recession can be overruled by episodic extreme droughts, we argue that the average contributions of precipitation variation, human activities in the Poyang Lake catchment and TGD regulation to the Poyang Lake recession can be quantified as 39.1%, 4.6% and 56.3%, respectively. PMID:26657816

Linkage between Three Gorges Dam impacts and the dramatic recessions in China’s largest freshwater lake, Poyang Lake

NASA Astrophysics Data System (ADS)

Mei, Xuefei; Dai, Zhijun; Du, Jinzhou; Chen, Jiyu

2015-12-01

Despite comprising a small portion of the earth’s surface, lakes are vitally important for global ecosystem cycling. However, lake systems worldwide are extremely fragile, and many are shrinking due to changing climate and anthropogenic activities. Here, we show that Poyang Lake, the largest freshwater lake in China, has experienced a dramatic and prolonged recession, which began in late September of 2003. We further demonstrate that abnormally low levels appear during October, 28 days ahead of the normal initiation of the dry season, which greatly imperiled the lake’s wetland areas and function as an ecosystem for wintering waterbirds. An increase in the river-lake water level gradient induced by the Three Gorges Dam (TGD) altered the lake balance by inducing greater discharge into the Changjiang River, which is probably responsible for the current lake shrinkage. Occasional episodes of arid climate, as well as local sand mining, will aggravate the lake recession crisis. Although impacts of TGD on the Poyang Lake recession can be overruled by episodic extreme droughts, we argue that the average contributions of precipitation variation, human activities in the Poyang Lake catchment and TGD regulation to the Poyang Lake recession can be quantified as 39.1%, 4.6% and 56.3%, respectively.

Geomorphic and hydraulic controls on large-scale riverbank failure on a mixed bedrock-alluvial river system, the River Murray, South Australia: a bathymetric analysis.

NASA Astrophysics Data System (ADS)

De Carli, E.; Hubble, T.

2014-12-01

During the peak of the Millennium Drought (1997-2010) pool-levels in the lower River Murray in South Australia dropped 1.5 metres below sea level, resulting in large-scale mass failure of the alluvial banks. The largest of these failures occurred without signs of prior instability at Long Island Marina whereby a 270 metre length of populated and vegetated riverbank collapsed in a series of rotational failures. Analysis of long-reach bathymetric surveys of the river channel revealed a strong relationship between geomorphic and hydraulic controls on channel width and downstream alluvial failure. As the entrenched channel planform meanders within and encroaches upon its bedrock valley confines the channel width is 'pinched' and decreases by up to half, resulting in a deepening thalweg and channel bed incision. The authors posit that flow and shear velocities increase at these geomorphically controlled 'pinch-points' resulting in complex and variable hydraulic patterns such as erosional scour eddies, which act to scour the toe of the slope over-steepening and destabilising the alluvial margins. Analysis of bathymetric datasets between 2009 and 2014 revealed signs of active incision and erosional scour of the channel bed. This is counter to conceptual models which deem the backwater zone of a river to be one of decelerating flow and thus sediment deposition. Complex and variable flow patterns have been observed in other mixed alluvial-bedrock river systems, and signs of active incision observed in the backwater zone of the Mississippi River, United States. The incision and widening of the lower Murray River suggests the channel is in an erosional phase of channel readjustment which has implications for riverbank collapse on the alluvial margins. The prevention of seawater ingress due to barrage construction at the Murray mouth and Southern Ocean confluence, allowed pool-levels to drop significantly during the Millennium Drought reducing lateral confining support to the over-steepened channel margins triggering large-scale riverbank failure.

Hydrologic indicators of hot spots and hot moments of mercury methylation along river corridors

NASA Astrophysics Data System (ADS)

Singer, Michael; Harrison, Lee; Donovan, Patrick; Blum, Joel; Marvin-DiPasquale, Mark

2016-04-01

The biogeochemical cycling of metals and other contaminants river-floodplain corridors is controlled by microbial activity is often affected by dynamic redox conditions. Riverine flooding thus has the potential to affect speciation of redox-sensitive metals such as mercury (Hg). Therefore, flow history over a period of decades potentially holds information on past production of bioavailable Hg. We investigate this process within a Northern California river system that has a legacy of industrial-scale 19th century hydraulic gold mining. In the first known application of this methodology, we combine hydraulic modeling, measurements of Hg species in sediment and biota, and first-order calculations to assess the role of river floodplains in producing monomethylmercury (MMHg), which accumulates in local and migratory biota. We identify areas that represent 'hot spots' (frequently inundated areas of floodplains) and 'hot moments' (floodplain areas inundated for consecutive long periods). We show that the probability of MMHg production in each sector of the river system is dependent on the spatial patterns of overbank flow and drainage, which affect its long-term redox history. MMHg bioaccumulation within the aquatic food web may pose a major risk to humans and waterfowl that eat migratory salmonids, which are being encouraged to come up these rivers to spawn, and there appears to be no end to MMHg production under a regime of increasingly common large floods with extended duration. These findings identify river floodplains as periodic, temporary, yet important, loci of biogeochemical transformation in which contaminants may undergo change during limited periods of the historical hydrologic record. We suggest that inundation is the primary driver of MMHg production in river corridors and that the entire flow history must be analyzed in terms of magnitude and frequency of inundation in order to accurately assess biogeochemical risks, rather than merely highlighting the largest floods.

Oceanic loading of wildfire-derived organic compounds from a small mountainous river

USGS Publications Warehouse

Hunsinger, G.B.; Mitra, Siddhartha; Warrick, J.A.; Alexander, C.R.

2008-01-01

Small mountainous rivers (SMRs) export substantial amounts of sediment into the world's oceans. The concomitant yield of organic carbon (OC) associated with this class of rivers has also been shown to be significant and compositionally unique. We report here excessively high loadings of polycyclic aromatic hydrocarbons (PAHs), lignin, and levoglucosan, discharged from the Santa Clara River into the Santa Barbara Channel. The abundance of PAHs, levoglucosan, and lignin in Santa Barbara Channel sediments ranged from 201.7 to 1232.3 ng gdw-1, 1.3 to 6.9 ??g gdw-1, and 0.3 to 2.2 mg per 100 mg of the sedimentary OC, respectively. Assuming a constant rate of sediment accumulation, the annual fluxes of PAHs, levoglucosan, and lignin, to the Santa Barbara Channel were respectively, 885.5 ?? 170.2 ng cm-2 a-1, 3.5 ?? 1.9 ??g cm-2 a-1 and 1.4 ?? 0.3 mg per 100 mg OC cm-2 a-1, over ???30 years. The close agreement between PAHs, levoglucosan, and lignin abundance suggests that the depositional flux of these compounds is largely biomass combustion-derived. To that end, use of the Santa Clara River as a model for SMRs suggests this class of rivers may be one of the largest contributors of pyrolyzed carbon to coastal systems and the open ocean. Wildfire associated carbon discharged from other high yield fluvial systems, when considered collectively, may be a significant source of lignin, pyrolytic PAHs, and other pyrogenic compounds to the ocean. Extrapolating these methods over geologic time may offer useful historical information about carbon sequestration and burial in coastal sediments and affect coastal carbon budgets. Copyright 2008 by the American Geophysical Union.

DEM Simulated Results And Seismic Interpretation of the Red River Fault Displacements in Vietnam

NASA Astrophysics Data System (ADS)

Bui, H. T.; Yamada, Y.; Matsuoka, T.

2005-12-01

The Song Hong basin is the largest Tertiary sedimentary basin in Viet Nam. Its onset is approximately 32 Ma ago since the left-lateral displacement of the Red River Fault commenced. Many researches on structures, formation and tectonic evolution of the Song Hong basin have been carried out for a long time but there are still remained some problems that needed to put into continuous discussion such as: magnitude of the displacements, magnitude of movement along the faults, the time of tectonic inversion and right lateral displacement. Especially the mechanism of the Song Hong basin formation is still in controversy with many different hypotheses due to the activation of the Red River fault. In this paper PFC2D based on the Distinct Element Method (DEM) was used to simulate the development of the Red River fault system that controlled the development of the Song Hong basin from the onshore to the elongated portion offshore area. The numerical results show the different parts of the stress field such as compress field, non-stress field, pull-apart field of the dynamic mechanism along the Red River fault in the onshore area. This propagation to the offshore area is partitioned into two main branch faults that are corresponding to the Song Chay and Song Lo fault systems and said to restrain the east and west flanks of the Song Hong basin. The simulation of the Red River motion also showed well the left lateral displacement since its onset. Though it is the first time the DEM method was applied to study the deformation and geodynamic evolution of the Song Hong basin, the results showed reliably applied into the structural configuration evaluation of the Song Hong basin.

Mercury biogeochemistry in the Idrija River, Slovenia, from above the mine into the Gulf of Trieste

USGS Publications Warehouse

Hines, M.E.; Horvat, M.; Faganeli, J.; Bonzongo, J.-C.J.; Barkay, T.; Major, E.B.; Scott, K.J.; Bailey, E.A.; Warwick, J.J.; Lyons, W.B.

2000-01-01

The Idrija Mine is the second largest Hg mine in the world which operated for 500 years. Mercury (Hg)-laden tailings still line the banks, and the system is a threat to the Idrija River and water bodies downstream including the Soca/Isonzo River and the Gulf of Trieste in the northern Adriatic Sea. A multidisciplinary study was conducted in June 1998 on water samples collected throughout the Idrija and Soca River systems and waters and sediments in the Gulf. Total Hg in the Idrija River increased >20-fold downstream of the mine from 60 ng liter-1 with methyl mercury (MeHg) accounting for ~0.5%. Concentrations increased again downstream and into the estuary with MeHg accounting for nearly 1.5% of the total. While bacteria upstream of the mine did not contain mercury detoxification genes (mer), such genes were detected in bacteria collected downstream. Benthic macroinvertebrate diversity decreased downstream of the mine. Gulf waters near the river mouth contained up to 65 ng liter-1 total Hg with ~0.05 ng liter-1 MeHg. Gulf sediments near the river mouth contained 40 ??g g-1 total Hg with MeHg concentrations of about 3 ng g-1. Hg in sediment pore waters varied between 1 and 8 ng liter-1, with MeHg accounting for up to 85%. Hg methylation and MeHg demethylation were active in Gulf sediments with highest activities near the surface. MeHg was degraded by an oxidative pathway with >97% C released from MeHg as CO2. Hg methylation depth profiles resembled profiles of dissolved MeHg. Hg-laden waters still strongly impact the riverine, estuarine, and marine systems. Macroinvertebrates and bacteria in the Idrija River responded to Hg stress, and high Hg levels persist into the Gulf. Increases in total Hg and MeHg in the estuary demonstrate the remobilization of Hg, presumably as HgS dissolution and recycling. Gulf sediments actively produce MeHg, which enters bottom waters and presumably the marine food chain. (C) 2000 Academic Press.

Characterizing seston in the Penobscot River Estuary.

PubMed

Meseck, Shannon L; Li, Yaqin; Sunila, Inke; Dixon, Mark; Clark, Paul; Lipsky, Christine; Stevens, Justin R; Music, Paul; Wikfors, Gary H

2017-10-01

The Penobscot River Estuary is an important system for diadromous fish in the Northeast United States of American (USA), in part because it is home to the largest remnant population of Atlantic salmon, Salmo salar, in the country. Little is known about the chemical and biological characteristics of seston in the Penobscot River Estuary. This study used estuarine transects to characterize the seston during the spring when river discharge is high and diadromous fish migration peaks in the Penobscot River Estuary. To characterize the seston, samples were taken in spring 2015 for phytoplankton identification, total suspended matter (TSM), percent organic TSM, chlorophyll a, particle size (2 μm-180 μm), particulate carbon and nitrogen concentrations, and stable carbon and nitrogen isotopes. The estuarine profiles indicate that TSM behaved non-conservatively with a net gain in the estuary. As phytoplankton constituted only 1/1000 of the particles, the non-conservative behavior of TSM observed in the estuary was most likely not attributable to phytoplankton. Particulate carbon and nitrogen ratios and stable isotope signals indicate a strong terrestrial, allochthonous signal. The seston in the Penobscot River Estuary was dominated by non-detrital particles. During a short, two-week time period, Heterosigma akashiwo, a phytoplankton species toxic to finfish, also was detected in the estuary. A limited number of fish samples, taken after the 2015 Penobscot River Estuary bloom of H. akashiwo, indicated frequent pathological gill damage. The composition of seston, along with ichthyotoxic algae, suggest the need for further research into possible effects upon resident and migratory fish in the Penobscot River Estuary. Published by Elsevier Ltd.

Water quality and the composition of fish and macroinvertebrate communities in the Devils and Pecos Rivers within and upstream from the Amistad National Recreation Area, Texas, 2005-7

USGS Publications Warehouse

Moring, J. Bruce

2012-01-01

The total number of fish species collected was the same in the Devils River and Pecos River, but the species found in the two rivers varied slightly. The number of fish species generally increased from the site farthest upstream to the site farthest downstream in the Devils River, and decreased between the site farthest upstream and site farthest downstream in the Pecos River. The redbreast sunfish was the most abundant species collected in the Devils River, and the blacktail shiner was the most abundant species collected in the Pecos River. Comparing the species from each river, the percentage of omnivorous fish species was larger at the more downstream sites closer to Amistad Reservoir, and the percentage of species tolerant of environmental stressors was larger in the Pecos River. The fish community, assessed on the basis of the number of shared species among the sites sampled, was more similar to the fish community at the other sites on the same river than it was to the fish community from any other site in the other river. More macroinvertebrate taxa were collected in the Devils River than in the Pecos River. The largest number of macroinvertebrate taxa were from the site second farthest downstream on the Devils River, and the smallest numbers of macroinvertebrate taxa were from the farthest downstream site on the Pecos River. Mayflies were more common in the Devils River, and caddisflies were less common than mayflies at most sites. Net-spinning caddisflies were more common at the Devils River sites. The combined percent of mayfly, caddisfly, and stonefly taxa was generally larger at the Pecos River sites. Riffle beetles were the most commonly collected beetle taxon among all sites, and water-penny beetles were only collected at the Pecos River sites. A greater number of true midge taxa were collected more than any other taxa at the genus and species taxonomic level. Non-insect macroinvertebrate taxa were more common at the Devils River sites. Corbicula sp. (presumably the introduced Asian clam) was found at sites in both rivers, and amphipods were more abundant in the Devils River. The Margalef species richness index, based on aquatic insect taxa only, was larger at the Devils River sites than at the Pecos River sites. The Hilsenhoff's biotic index was largest at the site farthest downstream in the Devils River and smallest at the site second farthest downstream in the Pecos River. Overall similarity among sites based on the number of shared macroinvertebrate taxa indicated that each site is more similar to other sites on the same river than to sites on the other river.

Surface-water-quality assessment of the lower Kansas River basin, Kansas and Nebraska; results of investigations, 1987-90

USGS Publications Warehouse

Helgesen, J.O.

1995-01-01

Surface-water-quality conditions and trends were assessed in the lower Kansas River Basin, which drains about 15,300 square miles of mainly agricultural land in southeast Nebraska and northeast Kansas. On the basis of established water-quality criteria, most streams in the basin were suitable for uses such as public-water supply, irrigation, and maintenance of aquatic life. However, most concerns identified from a previous analysis of available data through 1986 are substantiated by analysis of data for May 1987 through April 1990. Less-than-normal precipitation and runoff during 1987-90 affected surface-water quality and are important factors in the interpretation of results.Dissolved-solids concentrations in the main stem Kansas River during May 1987 through April 1990 commonly exceeded 500 milligrams per liter, which may be of concern for public-water supplies and for the irrigation of sensitive crops. Large concentrations of chloride in the Kansas River are derived from ground water discharging in the Smoky Hill River Basin west of the study unit. Trends of increasing concentrations of some dissolved major ions were statistically significant in the northwestern part of the study unit, which could reflect substantial increases in irrigated acreage.The largest concentrations of suspended sediment in streams during May 1987 through April 1990 were associated with high-density cropland in areas of little local relief and medium-density irrigated cropland in more dissected areas. The smallest concentrations were measured downstream from large reservoirs and in streams draining areas having little or no row-crop cultivation. Mean annual suspended-sediment transport rates in the main stem Kansas River increased substantially in the downstream direction. No conclusions could be reached concerning the relations of suspended-sediment transport, yields, or trends to natural and human factors.The largest sources of nitrogen and phosphorus in the study unit were fertilizer and livestock. Nitrate-nitrogen concentrations in stream-water samples did not exceed 10 milligams per liter; relatively large concentrations in the northwestern part of the study unit were associated with fertilizer application. Concentrations of total phosphorus generally were largest in the northwestern part of the study unit, which probably relates to the prevalence of cultivated land, fertilizer application, and livestock wastes.Deficiencies in dissolved-oxygen concentrations in streams occurred locally, as a result of discharges from wastewater-treatment plants, algal respiration, and inadequate reaeration associated with small streamflow. Large densities of a fecal-indicator bacterium, Escherichia coli, were associated with discharges from municipal wastewater-treatment plants and, especially in the northwestern part of the study unit, with transport of fecaThe largest concentrations of the herbicide atrazine generally were measured where the largest quantities of atrazine were applied to the land. Large atrazine concentrations, 10 to 20 micrograms per liter, were measured most frequently in unregulated principal streams during May and June. Downstream of reservoirs, the seasonal variability of atrazine concentrations was decreased compared to that of inflowing streams.

Hydrology of area 25, Eastern Region, Interior Coal Province, Illinois

USGS Publications Warehouse

Zuehls, E.E.; Ryan, G.L.; Peart, D.B.; Fitzgerald, K.K.

1981-01-01

The eastern region of the Interior Coal Province has been divided into 11 hydrologic study areas. Area 25, located in west-central Illinois, includes the Spoon River and small tributaries to the Illinois River. Pennsylvanian age rocks underlie most of the study area. Illinois, with the largest reserves of bituminous coal, is second only to Montana in total coal reserves. Loess soils cover most of the study area. Agriculture is the dominant land use. Surface water provides 97% of all the water used. Precipitation averages 34 to 35 inches. Water-quality data has been collected at over 31 sites. Analysis for specific conductance, pH, alkalinity, iron, manganese, sulfate and many trace elements and other water-quality constituents have been completed. These data are available from computer storage through the National Water Data Storage and Retrieval System (WATSTORE). (USGS)

Trace metals in estuaries in the Russian Far East and China: case studies from the Amur River and the Changjiang.

PubMed

Shulkin, Vladimir; Zhang, Jing

2014-11-15

This paper compares the distributions of dissolved and particulate forms of Mn, Fe, Ni, Cu, Zn, Cd, and Pb in the estuaries of the largest rivers in East Asia: the Amur River and the Changjiang (Yangtze River). High suspended solid concentrations, elevated pH, and relatively low dissolved trace metal concentrations are characteristics of the Changjiang. Elevated dissolved Fe and Mn concentrations, neutral pH, and relatively low suspended solid concentrations are characteristics of the Amur River. The transfer of dissolved Fe to suspended forms is typical in the Amur River estuary, though Cd and Mn tend to mobilize to solution, and Cu and Ni are diluted in the estuarine system. Metal concentrations in suspended matter in the Amur River estuary are controlled by the ratio of terrigenous riverine material, enriched in Al and Fe, and marine biogenic particles, enriched in Cu, Mn, Cd, and in some cases Ni. The increase in dissolved forms of Mn, Fe, Ni, Cu, Cd, and Pb compared with river end-member is unique to the Changjiang estuary. Particle-solution interactions are not reflected in bulk suspended-solid metal concentrations in the Changjiang estuary due to the dominance of particulate forms of these metals. Cd is an exception in the Changjiang estuary, where the increase in dissolved Cd is of comparable magnitude to the decrease in particulate Cd. Despite runoff in the Amur River being lower than that in the Changjiang, the fluxes of dissolved Mn, Zn and Fe in the Amur River exceed those in the Changjiang. Dissolved Ni, and Cd fluxes are near equal in both estuaries, but dissolved Cu is lower in the Amur River estuary. The hydrological and physico-chemical river characteristics are dominated at the assessment of river influence on the adjoining coastal sea areas despite differences in estuarine processes. Copyright © 2014 Elsevier B.V. All rights reserved.

Novel Control Strategy for Multiple Run-of-the-River Hydro Power Plants to Provide Grid Ancillary Services

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

Mohanpurkar, Manish; Luo, Yusheng; Hovsapian, Rob

Hydropower plant (HPP) generation comprises a considerable portion of bulk electricity generation and is delivered with a low-carbon footprint. In fact, HPP electricity generation provides the largest share from renewable energy resources, which include wind and solar. Increasing penetration levels of wind and solar lead to a lower inertia on the electric grid, which poses stability challenges. In recent years, breakthroughs in energy storage technologies have demonstrated the economic and technical feasibility of extensive deployments of renewable energy resources on electric grids. If integrated with scalable, multi-time-step energy storage so that the total output can be controlled, multiple run-of-the-river (ROR)more » HPPs can be deployed. Although the size of a single energy storage system is much smaller than that of a typical reservoir, the ratings of storages and multiple ROR HPPs approximately equal the rating of a large, conventional HPP. This paper proposes cohesively managing multiple sets of energy storage systems distributed in different locations. This paper also describes the challenges associated with ROR HPP system architecture and operation.« less

Using Flow-Ecology Relationships to Evaluate Ecosystem Service Trade-Offs and Complementarities in the Nation's Largest River Swamp.

PubMed

Kozak, Justin P; Bennett, Micah G; Hayden-Lesmeister, Anne; Fritz, Kelley A; Nickolotsky, Aaron

2015-06-01

Large river systems are inextricably linked with social systems; consequently, management decisions must be made within a given ecological, social, and political framework that often defies objective, technical resolution. Understanding flow-ecology relationships in rivers is necessary to assess potential impacts of management decisions, but translating complex flow-ecology relationships into stakeholder-relevant information remains a struggle. The concept of ecosystem services provides a bridge between flow-ecology relationships and stakeholder-relevant data. Flow-ecology relationships were used to explore complementary and trade-off relationships among 12 ecosystem services and related variables in the Atchafalaya River Basin, Louisiana. Results from Indicators of Hydrologic Alteration were reduced to four management-relevant hydrologic variables using principal components analysis. Multiple regression was used to determine flow-ecology relationships and Pearson correlation coefficients, along with regression results, were used to determine complementary and trade-off relationships among ecosystem services and related variables that were induced by flow. Seven ecosystem service variables had significant flow-ecology relationships for at least one hydrologic variable (R (2) = 0.19-0.64). River transportation and blue crab (Callinectes sapidus) landings exhibited a complementary relationship mediated by flow; whereas transportation and crawfish landings, crawfish landings and crappie (Pomoxis spp.) abundance, and blue crab landings and blue catfish (Ictalurus furcatus) abundance exhibited trade-off relationships. Other trade-off and complementary relationships among ecosystem services and related variables, however, were not related to flow. These results give insight into potential conflicts among stakeholders, can reduce the dimensions of management decisions, and provide initial hypotheses for experimental flow modifications.

Using Flow-Ecology Relationships to Evaluate Ecosystem Service Trade-Offs and Complementarities in the Nation's Largest River Swamp

NASA Astrophysics Data System (ADS)

Kozak, Justin P.; Bennett, Micah G.; Hayden-Lesmeister, Anne; Fritz, Kelley A.; Nickolotsky, Aaron

2015-06-01

Large river systems are inextricably linked with social systems; consequently, management decisions must be made within a given ecological, social, and political framework that often defies objective, technical resolution. Understanding flow-ecology relationships in rivers is necessary to assess potential impacts of management decisions, but translating complex flow-ecology relationships into stakeholder-relevant information remains a struggle. The concept of ecosystem services provides a bridge between flow-ecology relationships and stakeholder-relevant data. Flow-ecology relationships were used to explore complementary and trade-off relationships among 12 ecosystem services and related variables in the Atchafalaya River Basin, Louisiana. Results from Indicators of Hydrologic Alteration were reduced to four management-relevant hydrologic variables using principal components analysis. Multiple regression was used to determine flow-ecology relationships and Pearson correlation coefficients, along with regression results, were used to determine complementary and trade-off relationships among ecosystem services and related variables that were induced by flow. Seven ecosystem service variables had significant flow-ecology relationships for at least one hydrologic variable ( R 2 = 0.19-0.64). River transportation and blue crab ( Callinectes sapidus) landings exhibited a complementary relationship mediated by flow; whereas transportation and crawfish landings, crawfish landings and crappie ( Pomoxis spp.) abundance, and blue crab landings and blue catfish ( Ictalurus furcatus) abundance exhibited trade-off relationships. Other trade-off and complementary relationships among ecosystem services and related variables, however, were not related to flow. These results give insight into potential conflicts among stakeholders, can reduce the dimensions of management decisions, and provide initial hypotheses for experimental flow modifications.

Evaluating Investment in Missouri River Restoration: The Missouri River Effects Analysis

NASA Astrophysics Data System (ADS)

Jacobson, R. B.; Fischenich, C. J.; Buenau, K. E.

2014-12-01

In excess of $700 million has been spent over the last 10 years on restoration of the Missouri River. During this time, restoration efforts have focused progressively on avoidance of jeopardy for three threatened or endangered species: interior least tern (Sternula antillarum), piping plover (Charadrius melodus), and the pallid sturgeon (Scaphirhynchus albus). In 2013, the US Army Corps of Engineers, the US Fish and Wildlife Service, and Missouri River stakeholders (through the Missouri River Recovery Implementation Committee) commissioned an Effects Analysis (EA; Murphy and Weiland, 2011) to evaluate the effects of this effort on the three species' populations and to project effects of future restoration. The EA includes synthesis of existing abiotic and biotic scientific information relating to species population processes, distributions, and habitat needs, as well as development of conceptual and quantitative models linking river context to its management and to species' responses. The EA also includes design of the next generation of hypothesis-driven science to support adaptive management of the species and the river. The Missouri River EA faces the challenge of evaluating how management of North America's largest reservoir storage system, 600 km of non-channelized mainstem, and nearly 1,200 km of channelized mainstem contribute to species' population dynamics. To support EA needs, the US Army Corps of Engineers is developing a new generation of reservoir simulation and routing models for the Missouri River basin, coupled with components to evaluate ecological and socio-economic metrics. The EA teams are developing coordinated models relating management to functional habitats and species' responses. A particular challenge faced by the EA is communicating the very different uncertainties in population dynamics between well-documented birds and the enigmatic fish, and the implications of this disparity in decision making, implementation, and adaptive management strategies.

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.

Contribution from the Yenisei River to the total radioactive contamination of the Kara Sea

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

Kuznetsov, Yu.V.; Revenko, Yu.A.; Legin, V.K.

1995-07-01

An attempt is made to estimate the contribution from the Yenisei River and, therefore, the Krasnoyarsk Mining and Chemical Plant (MCP), which discharged wastewaters to the Yenisei, to the total contamination of the Kara Sea using results from a study of the radioactive contamination of the Yenisei River, Yenisei Bay, Yenisei Gulf, and the Kara Sea itself. Radionuclides generated from using river water in cooling circuits of production reactors make the largest contribution to the total activity. The radioactive contamination of the river decreased by more than 20 times after two of the three operating reactors were shut down. Onlymore » several wetlands are actually affected by MCP hundreds of kilometers from the discharge point.« less

Restoration of bottomland hardwood forests in Lower Mississippi Aluvial Valey, U.S.A

Treesearch

Emile S. Gardiner; James M. Oliver

2005-01-01

The world's third largest river, the Mississippi, extends more than 3700 km through the central U.S. where it drains 41% of the conterminous U.S. before reaching the Gulf of Mexico. The river historically served as a primary travel corridor and trade route for Native American Indians, provided access for exploration and colonization to early European settlers, and...

Students as Water Monitoring Experts--New Forms of Environmental Learning in the 'Schools for a Living River Elbe' Project.

ERIC Educational Resources Information Center

Bosler, Ulrich; Lehmann, Jurgen

2001-01-01

Describes the cross-national educational network, Schools for a Living River Elbe. The project is thought to be the largest educational water-quality project in the world. The establishment of the project and the results of an initial survey show that the project is in a position to develop instructional and ecologically stimulating activities.…

Environmental setting and water-quality issues of the Mobile River Basin, Alabama, Georgia, Mississippi, and Tennessee

USGS Publications Warehouse

Johnson, Gregory C.; Kidd, Robert E.; Journey, Celeste A.; Zappia, Humbert; Atkins, J. Brian

2002-01-01

The Mobile River Basin is one of over 50 river basins and aquifer systems being investigated as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program. This basin is the sixth largest river basin in the United States, and fourth largest in terms of streamflow, encompassing parts of Alabama, Georgia, Mississippi, and Tennessee. Almost two-thirds of the 44,000-square-mile basin is located in Alabama. Extensive water resources of the Mobile River Basin are influenced by an array of natural and cultural factors. These factors impart unique and variable qualities to the streams, rivers, and aquifers providing abundant habitat to sustain the diverse aquatic life in the basin. Data from Federal, State, and local agencies provide a description of the environmental setting of the Mobile River Basin. Environmental data include natural factors such as physiography, geology, soils, climate, hydrology, ecoregions, and aquatic ecology, and human factors such as reservoirs, land use and population change, water use, and water-quality issues. Characterization of the environmental setting is useful for understanding the physical, chemical, and biological characteristics of surface and ground water in the Mobile River Basin and the possible implications of that environmental setting for water quality. The Mobile River Basin encompasses parts of five physiographic provinces. Fifty-six percent of the basin lies within the East Gulf section of the Coastal Plain Physiographic Province. The remaining northeastern part of the basin lies, from west to east, within the Cumberland Plateau section of the Appalachian Plateaus Physiographic Province, the Valley and Ridge Physiographic Province, the Piedmont Physiographic Province, and the Blue Ridge Physiographic Province. Based on the 1991 land-use data, about 70 percent of the basin is forested, while agriculture, including livestock (poultry, cattle, and swine), row crops (cotton, corn, soybeans, sorghum, and wheat), and pasture land accounts for about 26 percent of the study unit. Agricultural land use is concentrated along the Black Prairie Belt district of the Coastal Plain. Urban areas account for only 3 percent of the total land use; however, the areal extent of the metropolitan statistical areas (MSA) may indicate more urban influences. The MSAs include urban areas outside of the city boundaries and can include adjacent counties. Seven MSAs are delineated in the Mobile River Basin, including Montgomery, Mobile, Tuscaloosa, Birmingham, Gadsden, Anniston, and Atlanta. The total population for the Mobile River Basin was about 3,673,100 in 1990. State water-quality agencies have identified numerous causes and sources of water-body impairment in the Mobile River Basin. In 1996, organic enrichment, dissolved oxygen depletion, elevated nutrient concentrations, and siltation were the most frequently cited causes of impairment, affecting the greatest number of river miles. Bacteria, acidic pH, and elevated metal concentrations also were identified as causes of impairment. The sources for impairment varied among river basins, were largely a function of land use, and were attributed primarily to municipal and industrial sources, mining, and agricultural activities.

Debris flows from tributaries of the Colorado River, Grand Canyon National Park, Arizona

USGS Publications Warehouse

Webb, Robert H.; Pringle, Patrick T.; Rink, Glenn R.

1989-01-01

A reconnaissance of 36 tributaries of the Colorado River indicates that debris flows are a major process by which sediment is transported to the Colorado River in Grand Canyon National Park. Debris flows are slurries of sediment and water that have a water content of less than about 40 percent by volume. Debris flows occur frequently in arid and semiarid regions. Slope failures commonly trigger debris flows, which can originate from any rock formation in the Grand Canyon. The largest and most frequent flows originate from the Permian Hermit Shale, the underlying Esplanade Sandstone of the Supai Group, and other formations of the Permian and Pennsylvanian Supai Group. Debris flows also occur in the Cambrian Muav Limestone and underlying Bright Angel Shale and the Quaternary basalts in the western Grand Canyon. Debris-flow frequency and magnitude were studied in detail in the Lava-Chuar Creek drainage at Colorado River mile 65.5; in the Monument Creek drainage at mile 93.5; and in the Crystal Creek drainage at mile 98.2. Debris flows have reached the Colorado River on an average of once every 20 to 30 years in the Lava-Chuar Creek drainage since about 1916. Two debris flows have reached the Colorado River in the last 25 years in Monument Creek. The Crystal Creek drainage has had an average of one debris flow reaching the Colorado River every 50 years, although the debris flow of 1966 has been the only flow that reached the Colorado River since 1900. Debris flows may actually reach the Colorado River more frequently in these drainages because evidence for all debris flows may not have been preserved in the channel-margin stratigraphy. Discharges were estimated for the peak flow of three debris flows that reached the Colorado River. The debris flow of 1966 in the Lava-Chuar Creek drainage had an estimated discharge of 4,000 cubic feet per second. The debris flow of 1984 in the Monument Creek drainage had a discharge estimated between 3,600 and 4,200 cubic feet per second. The debris flow of 1966 in the Crystal Creek drainage had a discharge estimated between 9,200 and 14,000 cubic feet per second. Determination of the effective cross-sectional area was a problem in all calculations involving superelevations on bends because areas near superelevation marks were 1.5 to 3.5 times larger than areas of upstream or downstream cross sections. Debris flows in the Grand Canyon generally are composed of 10 to 40 percent sand by weight and may represent a significant source of beach-building sand along the Colorado River. The particle-size distributions are very poorly sorted and the largest transported boulders were in the Crystal Creek drainage. The large boulders transported into the Colorado River by debris flows create or change hydraulic controls (rapids); these controls appear to be governed by the magnitude and frequency of tributary-flow events and the history of discharges on the Colorado River. Reworking of debris fans by the Colorado River creates debris bars that constrain the size of eddy systems and forms secondary rapids and riffles below tributary mouths.

Source-To-Sink Perspectives On The Mississippi River System, Miocene To Present, Mountain To Abyss

NASA Astrophysics Data System (ADS)

Bentley, S. J.; Blum, M. D.

2013-12-01

. The objective of this study is to present a synthesis of the Mississippi River source-to-sink system, from montane source to abyssal sink, to elucidate specific geomorphic components and boundaries in the system, controls on mass transfer, and resultant geomorphic and statigraphic development. The Mississippi River source-to-sink system constitutes one of the largest sources, conduits, and depocenters of sediment on Earth, extending from elevations of 3.7 km in the Rocky Mountains to the Gulf of Mexico abyssal plain. Despite being one of the most intensely studied fluvial-marine systems in the world, comprehensive understanding and management of the system's resources remain a challenge. The system is valuable in many ways: it provides navigation and water to the heart of North America, and sustains extensive marine fisheries. The river has built a delta that is home to millions of people and yet is subsiding rapidly. Ancestral Mississippi fluvial-marine deposits continue to yield high-value petroleum resources to exploration. To address the range of temporal and spatial scales over which the system has developed and continues to evolve, we will focus on three geological time spans that display contrasting geologic forcing and response: Miocene, Pleistocene, and late Holocene. The present configuration of source, conduit, and sink were established during the Miocene epoch, when tectonics (via the uplifting southern Rockies, and later the rejuvenated Appalachians) and climate (wet in the east and dry in the west) provided abundant water and sediment to prograde the shelf margin and initiate deep-sea fan growth. Pleistocene continental glaciation, eustasy, and catastrophic drainage events further sculpted the alluvial valley, and extended the shelf margin, and fan. Studies of Modern processes and Holocene delta development have provided keys to both the delta's past and future evolution, in terms of cyclic autogenic lobe-switching, mass-transport events, storm-driven sediment delivery to canyon heads, and allogenic/anthropogenic controls on sediment supply and subsidence.

Spatial and temporal variance in fatty acid and stable isotope signatures across trophic levels in large river systems

USGS Publications Warehouse

Fritts, Andrea; Knights, Brent C.; Lafrancois, Toben D.; Bartsch, Lynn; Vallazza, Jon; Bartsch, Michelle; Richardson, William B.; Karns, Byron N.; Bailey, Sean; Kreiling, Rebecca

2018-01-01

Fatty acid and stable isotope signatures allow researchers to better understand food webs, food sources, and trophic relationships. Research in marine and lentic systems has indicated that the variance of these biomarkers can exhibit substantial differences across spatial and temporal scales, but this type of analysis has not been completed for large river systems. Our objectives were to evaluate variance structures for fatty acids and stable isotopes (i.e. δ13C and δ15N) of seston, threeridge mussels, hydropsychid caddisflies, gizzard shad, and bluegill across spatial scales (10s-100s km) in large rivers of the Upper Mississippi River Basin, USA that were sampled annually for two years, and to evaluate the implications of this variance on the design and interpretation of trophic studies. The highest variance for both isotopes was present at the largest spatial scale for all taxa (except seston δ15N) indicating that these isotopic signatures are responding to factors at a larger geographic level rather than being influenced by local-scale alterations. Conversely, the highest variance for fatty acids was present at the smallest spatial scale (i.e. among individuals) for all taxa except caddisflies, indicating that the physiological and metabolic processes that influence fatty acid profiles can differ substantially between individuals at a given site. Our results highlight the need to consider the spatial partitioning of variance during sample design and analysis, as some taxa may not be suitable to assess ecological questions at larger spatial scales.

Sand deposition in shoreline eddies along five Wild and Scenic Rivers, Idaho

USGS Publications Warehouse

Andrews, E.D.; Vincent, K.R.

2007-01-01

Sand bars deposited along the lateral margin of a river channel are frequently a focus of recreational activities. Sand bars are appealing sites on which to camp, picnic, fish and relax because they are relatively flat, soft, non-cohesive sand, free of vegetation and near the water's edge. The lack of vegetation and cohesion make sand bars easily erodible. Without appreciable deposition of new material, number and size of bars through a given reach of river will decline substantially over a period of years. We studied 63 beaches and their associated eddies located throughout 10 selected reaches within the designated Wild and Scenic River sections of the Lochsa, Selway, Middle Fork Clearwater, Middle Fork Salmon and Salmon Rivers in Idaho to determine the relation of beaches to the frequency and magnitude of streamflows that deposit appreciable quantities of sand. At present, these rivers have been altered little, if at all, by flow regulation, and only the Salmon River has substantial diversion upstream of a study reach. The river reaches studied have an abundance of sand bar beaches of appreciable size, in spite of suspended sand concentrations that rarely exceeded a few hundred milligrams per litre even during the largest floods. Calculated mean annual rates of deposition in an eddy vary from 5.8 to more than 100 cm depending primarily on: (1) the duration of streamflows that inundate the eddy sand bar depositions; (2) the rate of the flow exchange between the channel and an eddy and (3) the concentrations of suspended sand in the primary channel. The annual thickness of sand deposition in an eddy varies greatly from year to year depending on the duration of relatively large streamflows. Maximum annual sand depositions in an eddy are three to nine times the estimated long-term mean values. Relatively large, sustained floods deposit an appreciable portion of total deposition over a period of years. For the period of record, 1930-2002, the seven largest annual depositions, which represent more than 40% of all material deposited over the Lochsa River 21.9 km eddy, occurred in the years with the seven largest instantaneous annual peak floods. Beach area and volume for most beaches, however, are less variable year-to-year than the variation in annual deposition would indicate. Accumulative 10-year weighed deposition rate was computed to estimate the effective variability of beach deposition. Although less variable than the annual deposition, the cumulative 10-year deposition calculated for the longest hydrologic records, 71 years, existing on the Idaho Wild and Scenic Rivers varied by more than an order of magnitude from less than 20 cm to more than 220 cm.

Integrated water system simulation by considering hydrological and biogeochemical processes: model development, with parameter sensitivity and autocalibration

NASA Astrophysics Data System (ADS)

Zhang, Y. Y.; Shao, Q. X.; Ye, A. Z.; Xing, H. T.; Xia, J.

2016-02-01

Integrated water system modeling is a feasible approach to understanding severe water crises in the world and promoting the implementation of integrated river basin management. In this study, a classic hydrological model (the time variant gain model: TVGM) was extended to an integrated water system model by coupling multiple water-related processes in hydrology, biogeochemistry, water quality, and ecology, and considering the interference of human activities. A parameter analysis tool, which included sensitivity analysis, autocalibration and model performance evaluation, was developed to improve modeling efficiency. To demonstrate the model performances, the Shaying River catchment, which is the largest highly regulated and heavily polluted tributary of the Huai River basin in China, was selected as the case study area. The model performances were evaluated on the key water-related components including runoff, water quality, diffuse pollution load (or nonpoint sources) and crop yield. Results showed that our proposed model simulated most components reasonably well. The simulated daily runoff at most regulated and less-regulated stations matched well with the observations. The average correlation coefficient and Nash-Sutcliffe efficiency were 0.85 and 0.70, respectively. Both the simulated low and high flows at most stations were improved when the dam regulation was considered. The daily ammonium-nitrogen (NH4-N) concentration was also well captured with the average correlation coefficient of 0.67. Furthermore, the diffuse source load of NH4-N and the corn yield were reasonably simulated at the administrative region scale. This integrated water system model is expected to improve the simulation performances with extension to more model functionalities, and to provide a scientific basis for the implementation in integrated river basin managements.

Understanding the hydrodynamics of the Congo River

NASA Astrophysics Data System (ADS)

O'Loughlin, Fiachra; Bates, Paul

2014-05-01

We present the results of the first hydrodynamic model of the middle reach of the Congo Basin, which helps our understanding of the behaviour of the second largest river in the world. In data sparse area, hydrodynamic models, utilizing a mixture of limited in-situ measurements and remotely sensed datasets, can be used to understand and identify key features that control large river systems. Unlike previous hydrodynamic models for the Congo Basin, which concentrated on only a small area, we look at the entire length of the Congo's middle reach and its six main tributaries (Kasai, Ubangai, Sangha, Ruki, Lulonga and Lomami). This corresponds to: a drainage area of approximately two and a half million kilometres squared; over 5000 kilometres of river channels; and incorporates some of the largest and most important global wetlands. The hydrodynamic model is driven by a mixture of in-situ and modelled discharges. In situ measurements are available at five locations. Two were obtained from the Global River Discharge Centre (GRDC) at Kinshasa and Bangui, and data for Kisangani, Ouesso and Lediba were obtained from local agencies in the Democratic Republic of the Congo and the Republic of Congo. Using the gauging station at Kinshasa as the downstream boundary, the remaining in-situ measurements account for 61 percent of the discharge and represent 72 percent of the total drainage area. Modelled discharges are used to account for the missing discharge and corresponding area. Calibration and validation of the model was undertaken using a mixture of in-situ measurements, discharge and water level at Kinshasa, and water surface heights along the main reach obtained from both laser and radar altimeters. Through the hydrodynamic model we will investigate: how important constraints, identified by a previous study, are to the behaviour of the Congo; what impacts the wetlands have on the Congo Basin; how the wetlands and main channel interact with each other. Our results will provide new insight into the behaviour of the middle reach of the Congo Basin which otherwise would not be possible without extensive field work.

Shortnose sturgeon use small coastal rivers: The importance of habitat connectivity

USGS Publications Warehouse

Zydlewski, Gayle B.; Kinnison, M.T.; Dionne, P.E.; Zydlewski, Joseph D.; Wippelhauser, Gail S.

2011-01-01

Contrary to conventional wisdom for shortnose sturgeon (Acipenser brevirostrum), we document shortnose sturgeon use of habitats beyond large rivers. Telemetry data from 2008 to 2010 in the Gulf of Maine demonstrates that adult shortnose sturgeon (up to 70%) frequently move between Maine’s two largest rivers, the Kennebec and Penobscot Rivers. Even more interesting, small rivers located between these watersheds were used by 52% of the coastal migrants. Small river use was not trivial, 80% of observed movements extended more than 10 km upstream. However, visits were short in duration. This pattern indicates one of several possibilities: directed use of resources, searching behaviors related to reproduction (i.e. straying) or undirected wandering. Data suggest a relationship between residence time in small rivers and distance to the lowermost barrier. Restoring connectivity to upstream habitats in these rivers could allow opportunities for metapopulation expansion. Regional management of shortnose sturgeon in the Gulf of Maine should incorporate a habitat framework that considers small coastal rivers.

Ongoing River Capture in the Amazon via Secondary Channel Flow

NASA Astrophysics Data System (ADS)

Goldberg, S. L.; Stokes, M.; Perron, J. T.

2017-12-01

The Rio Casiquiare in South America is a secondary channel that originates as a distributary of the Rio Orinoco and flows into the Rio Negro as a tributary to form a perennial connection between the Amazon and Orinoco basins, the largest and fourth-largest rivers on Earth by discharge. This unusual configuration is the result of an incomplete and ongoing river capture in which the Rio Negro is actively capturing the upper Rio Orinoco. This rarely observed intermediate stage of capture illuminates important mechanisms that drive river capture in lowland settings, both in the Amazon basin and elsewhere. In particular, we show that the capture of the Rio Orinoco by the Rio Casiquiare is driven by a combination of headward incision of a rapidly eroding tributary of the Rio Negro, sedimentation in the Rio Orinoco downstream of the bifurcation, and seasonal inundation of a low-relief divide. The initiation of the bifurcation by headward erosion caused an increase in discharge to the Rio Casiquiare while the corresponding loss of discharge to the downstream Rio Orinoco has led to observable sedimentation within the main channel. Unlike most ephemeral secondary channels, the Rio Casiquiare appears to be growing, suggesting that the present bifurcation is an unstable feature that will eventually lead to the complete capture of the upper Rio Orinoco by the Rio Casiquiare. This capture is the latest major event in the late Cenozoic drainage evolution of South America in response to Andean tectonism, and is an example of the lateral expansion of the Amazon basin through river capture following integration and entrenchment of the transcontinental Amazon River. The Rio Casiquiare provides a snapshot of an intermediate, transient state of bifurcation and inter-basin flow via a secondary channel during lowland river capture.

Morphosedimentary dynamics of the Madeira River in Brazil

NASA Astrophysics Data System (ADS)

Bonthius, C.; Latrubesse, E. M.; Abad, J. D.

2012-12-01

The Madeira River, the largest tributary of the Amazon River in terms of water discharge, offers an opportunity to investigate extrinsic and intrinsic controls on channel morphology and pattern. With an average annual discharge of approximately 32,000 m3/s, the Madeira River is a mega-river with a unique anabranching channel pattern, a specific stream power of approximately 20 W/m2, and a width-depth ratio that ranges between 30 and 64 (Latrubesse 2008). Not only of interest for its size and discharge, the Madeira River is also a critical ecological component of the overall Amazon Basin. As the greatest contributor of sediment to the Amazon fluvial system, the Madeira River transports approximately 330 tons/km2 annually, which is about half of the Amazon River's total sediment output (Latrubesse et al 2005). This poster presents analyses of the morphology of the Madeira River and of data collected from a field campaign carried out in summer 2011 on a stretch between Porto Velho and Humaitá in Brazil. Using historical radar and satellite imagery of consistent spatial and temporal resolution, the stability and morphology of in-channel landforms are assessed and quantified. Stretches characterized by vegetated islands demonstrated overall stability; these features were temporally persistent and showed little, if any, change in area over a period of forty years. Sand bars, or un-vegetated sediment, are highly mutable features with numbers that vary between nine and twenty-seven in a same single stretch over time. The main channel also demonstrated stability in its morphology, while the presence and activation of secondary channels varied. Velocity maps and an analysis of secondary currents are presented from data collected from bathymetric surveys and an Acoustic Doppler Current Profiler (ADCP) from Porto Velho and Humaitá. Hydraulic factors in two complex and geologically controlled river reaches, a mainly meandering reach with a tendency to anabranch and a purely anabranching reach, are compared, offering insight into the roles of these intrinsic variables in the fluvial system. Sediment samples collected during the field campaign were analyzed for grain size composition. Connections between median grain size (d50), hydraulic variables, and channel morphology are discussed in context of the resulting channel pattern. These analyses also shed light on differences that exist between the Madeira River and other large fluvial systems. Currently endangered by impoundment with hydroelectric projects expected to be fully operational by January of 2013, the Madeira River is a mega-river that faces irreversible change due to human impact. As a result, the collection and analysis of data of current baseline conditions is of timely and necessary importance to assess geomorphologic and hydrologic changes in the fluvial system, model the river's behavior under a variety of natural and anthropogenic conditions, and inform management plans for the Madeira River and Amazon River basins. References Latrubesse, E.M. 2008. Patterns of anabranching channels: the ultimate end-member adjustment of mega-rivers. Geomorphology, 101, pp. 130-145. Latrubesse, E.M., Stevaux, J.C. and Sinha, R. 2005. Tropical Rivers. Geomorphology, 70, pp. 187-206.

A comparison of drainage basin nutrient inputs with instream nutrient loads for seven rivers in Georgia and Florida, 1986-90

USGS Publications Warehouse

Asbury, C.E.; Oaksford, E.T.

1997-01-01

Instream nutrient loads of the Altamaha, Suwannee, St. Johns, Satilla, Ogeechee, Withlacoochee, and Ochlockonee River Basins were computed and compared with nutrient inputs for each basin for the period 1986-90. Nutrient constituents that were considered included nitrate, ammonia, organic nitrogen, and total phosphorus. Sources of nutrients considered for this analysis included atmospheric deposition, fertilizer, animal waste, wastewater-treatment plant discharge, and septic discharge. The mean nitrogen input ranged from 2,400 kilograms per year per square kilometer (kg/yr)km2 in the Withlacoochee River Basin to 5,470 (kg/yr)km2 in the Altamaha River Basin. The Satilla and Ochlockonee River Basins also had large amounts of nitrogen input per unit area, totaling 5,430 and 4,920 (kg/yr)km2, respectively.Fertilizer or animal waste, as sources of nitrogen, predominated in all basins. Atmospheric deposition contributed less than one-fourth of the mean total nitrogen input to all basins and was consistently the third largest input in all but the Ogeechee River Basin, where it was the second largest.The mean total phosphorus input ranged from 331 (kg/yr)km2 in the Withlacoochee River Basin to 1,380 (kg/yr)km2 in both the Altamaha and Satilla River Basins. The Ochlockonee River Basin had a phosphorus input of 1,140 (kg/yr)km2.Per unit area, the Suwannee River discharged the highest instream mean total nitrogen and phosphorus loads and also discharged higher instream nitrate loads per unit area than the other six rivers. Phosphorus loads in stream discharge were highest in the Suwannee and Ochlockonee Rivers.The ratio of nutrient outputs to inputs for the seven studied rivers ranged from 4.2 to 14.9 percent, with the St. Johns (14.9 percent) and Suwannee (12.1 percent) Rivers having significantly higher percentages than those from the other basins. The output/input percentages for mean total phosphorus ranged from 1.0 to 7.0 percent, with the St. Johns (6.2 percent) and Suwannee (7.0 percent) Rivers exporting the highest percentage of phosphorus.Although instream nutrient loads constitute only one of the various pathways nutrients may take in leaving a river basin, only a relatively small part of nutrient input to the basin leaves the basin in stream discharge for the major coastal rivers examined in this study. The actual amount of nutrient transported in a river basin depends on the ways in which nutrients are physically handled, geographically distributed, and chemically assimilated within a river basin.

Abiotic characteristics and microalgal dynamics in South Africa's largest estuarine lake during a wet to dry transitional phase

NASA Astrophysics Data System (ADS)

Nunes, Monique; Adams, Janine B.; Bate, Guy C.; Bornman, Thomas G.

2017-11-01

The summer of 2012/2013 signified the end of the dry phase in the St Lucia estuarine system that lasted for over a decade. The increased rainfall coupled with the partial re-connection of the Mfolozi River to the estuarine system shifted St Lucia to a new limnetic state. With the increased availability of habitat due to the higher water level, it was expected that microalgal biomass and abundance would rapidly increase through recruitment from refuge areas i.e. South Lake and new introductions. Microalgal and physico-chemical data were collected at three sites within the Mfolozi/Msunduzi River and at 23 sites within the St Lucia estuarine system between June 2014 and February 2015. Results from this study indicated low biomass for both phytoplankton (<5 μg l-1) and microphytobenthos (<60 mg m-2) because of local and external drivers. These included limited nutrient and light availability, variable water residence times, biomass dilution and heterogeneity of the sediment. The high spatio-temporal variability limits the effectiveness of using the microalgal communities to detect change in the estuarine lake. In addition, significant intrasystem differences were observed between the three main lake basins and Narrows, due to the influence of the freshwater input from the Mfolozi River. This study provides insight into the spatio-temporal variability of physico-chemical conditions and microalgal communities during the 2014-2015 limnetic state.

Emissions from ships in the northwestern United States.

PubMed

Corbett, James J

2002-03-15

Recent inventory efforts have focused on developing nonroad inventories for emissions modeling and policy insights. Characterizing these inventories geographically and explicitly treating the uncertaintiesthat result from limited emissions testing, incomplete activity and usage data, and other important input parameters currently pose the largest methodological challenges. This paper presents a commercial marine vessel (CMV) emissions inventory for Washington and Oregon using detailed statistics regarding fuel consumption, vessel movements, and cargo volumes for the Columbia and Snake River systems. The inventory estimates emissions for oxides of nitrogen (NOx), particulate matter (PM), and oxides of sulfur (SOx). This analysis estimates that annual NOx emissions from marine transportation in the Columbia and Snake River systems in Washington and Oregon equal 6900 t of NOx (as NO2) per year, 2.6 times greater than previous NO, inventories for this region. Statewide CMV NO, emissions are estimated to be 9,800 t of NOx per year. By relying on a "bottom-up" fuel consumption model that includes vessel characteristics and transit information, the river system inventory may be more accurate than previous estimates. This inventory provides modelers with bounded parametric inputs for sensitivity analysis in pollution modeling. The ability to parametrically model the uncertainty in commercial marine vessel inventories also will help policy-makers determine whether better policy decisions can be enabled through further vessel testing and improved inventory resolution.

An integrated water system model considering hydrological and biogeochemical processes at basin scale: model construction and application

NASA Astrophysics Data System (ADS)

Zhang, Y. Y.; Shao, Q. X.; Ye, A. Z.; Xing, H. T.

2014-08-01

Integrated water system modeling is a reasonable approach to provide scientific understanding and possible solutions to tackle the severe water crisis faced over the world and to promote the implementation of integrated river basin management. Such a modeling practice becomes more feasible nowadays due to better computing facilities and available data sources. In this study, the process-oriented water system model (HEXM) is developed by integrating multiple water related processes including hydrology, biogeochemistry, environment and ecology, as well as the interference of human activities. The model was tested in the Shaying River Catchment, the largest, highly regulated and heavily polluted tributary of Huai River Basin in China. The results show that: HEXM is well integrated with good performance on the key water related components in the complex catchments. The simulated daily runoff series at all the regulated and less-regulated stations matches observations, especially for the high and low flow events. The average values of correlation coefficient and coefficient of efficiency are 0.81 and 0.63, respectively. The dynamics of observed daily ammonia-nitrogen (NH4N) concentration, as an important index to assess water environmental quality in China, are well captured with average correlation coefficient of 0.66. Furthermore, the spatial patterns of nonpoint source pollutant load and grain yield are also simulated properly, and the outputs have good agreements with the statistics at city scale. Our model shows clear superior performance in both calibration and validation in comparison with the widely used SWAT model. This model is expected to give a strong reference for water system modeling in complex basins, and provide the scientific foundation for the implementation of integrated river basin management all over the world as well as the technical guide for the reasonable regulation of dams and sluices and environmental improvement in river basins.

Geology of the Knife River area, North Dakota

USGS Publications Warehouse

Benson, William Edward

1953-01-01

The Knife River area, consisting of six 15-minute quadrangles, includes the lower half of the Knife River valley in west-central North Dakota. The area, in the center of the Williston Basin, is underlain by the Tongue River member of the Fort Union formation (Paleocene) and the Golden Valley formation (Eocene). The Tongue River includes beds equivalent to the Sentinel Butte shale; the Golden Valley formation, which receives its first detailed description in this report, consists of two members, a lower member of gray to white sandy kaolin clay and an upper member of cross-bedded micaceous sandstone. Pro-Tongue River rocks that crop out in southwestern North Dakota include the Ludlow member of the Fort Union formation, the Cannonball marine formation (Paleocene) and the Hell Creek, Fox Hills, and Pierre formations, all upper Cretaceous. Post-Golden Valley rocks include the White River formation (Oligocene) and gravels on an old planation surface that may be Miocene or Pliocent. Surficial deposits include glacial and fluvial deposits of Pleistocene age and alluvium, dune sand, residual silica, and landslide blocks of Recent age. Three ages of glacial deposits can be differentiated, largely on the basis of three fills, separated by unconformities, in the Knife River valley. All three are of Wisconsin age and probably represent the Iowan, Tazewell, and Mankato substages. Deposits of the Cary substage have not been identified either in the Knife River area or elsewhere in southern North Dakota. Iowan glacial deposits form the outermost drift border in North Dakota. Southwest of this border are a few scattered granite boulders that are residual from the erosion of either the White River formation or a pre-Wisconsin till. The Tazewell drift border cannot be followed in southern North Dakota. The Mankato drift border can be traced in a general way from the South Dakota State line northwest across the Missouri River and through the middle of the Knife River area. The major land forms of southwestern North Dakota are: (1) high buttes that stand above (2) a gravel-capped planation surface and (3) a gently-rolling upland; below the upland surface are (4) remnants of a broad valley stage of erosion into which (5) modern valleys have been cut. The broad valley profiles of many streams continue east across the Missouri River trench and are part of a former drainage system that flowed into Hudson Bay. Crossing the divides are (6) large trenches, formed when the former northeast-flowing streams were dammed by the glacier and diverted to the southeast. The largest diversion valley is occupied by the Missouri River; another diversion system, now largely abandoned, extends from the Killdeer Mountains southwest to the mouth of Porcupine Creek in Sioux County. By analogy with South Dakota, most of the large diversion valleys are thought to have been cut in Illinoian time. Numerous diversion valleys of Illinoian to late Wisconsin age cut across the divides. Other Pleistocene land forms include ground and moraines, kames, and terraces. Land forms of Recent age include dunes, alluvial terraces, floodplains, and several types of landslide blocks. One type of landslide, called rockslide slump, has not previously been described. Drainage is well adjusted to the structure, most of the streams flowing down the axes of small synclines. The bedrock formations have been gently folded into small domes and synclines that interrupt a gentle northward regional dip into the Williston Basin. Three episodes of deformation affected southwestern North Dakota in Tertiary time: (1) intra-Paleocene, involving warping and minor faulting; (2) post-Eocene, involving uplift and tilting; (2) Oligocene, involving uplift and gentle folding. Mineral resources include ceramic clay, sand and gravel and lignite coal. The Knife River area is the largest lignite-producing district in the United States.

Assessing and managing the risks of hypoxia in transitional waters: a case study in the tidal Garonne River (South-West France).

PubMed

Schmidt, Sabine; Bernard, Clément; Escalier, Jean-Michel; Etcheber, Henri; Lamouroux, Mélina

2017-02-01

The Gironde estuary (S-W France) is one of the largest European macrotidal estuaries. In the tidal Garonne River, its main tributary, episodes of low (<5 mg L -1 ) to hypoxic (<2 mg L -1 ) dissolved oxygen (DO) concentrations have been occasionally recorded close to Bordeaux, about 100 km from the mouth. Projected long-term environmental changes (increase in temperature and population, decrease in river discharge) suggest the establishment of summer chronic oxygen deficiency in the tidal Garonne River in the next decades. Assessing and managing the risk of hypoxia on such a large, hyper-turbid fluvio-estuarine system is complex, due to the different forcing factors (temperature, river discharge, turbidity, urban wastes) acting over a wide range of temporal and spatial scales. In this context, we show the interest of a real-time, high-frequency monitoring of the water quality, the MAGEST network, which continuously records since 2005 temperature, salinity, turbidity, and dissolved oxygen in surface waters in Bordeaux. Through the analysis of the 10-year DO records, we demonstrate the interest of a high-frequency, long-term database to better document DO variability and to define the controlling factors of DO concentrations. This real-time monitoring is also of great interest for the development of manager's oriented tools and the follow-up of DO objectives in the tidal Garonne River.

Climate impacts on connectivity of snowmelt to flow in the ...

EPA Pesticide Factsheets

Much of the water that people in Western Oregon rely on comes from snowpack in the Cascade Range, and this snowpack is expected to decrease in coming years with climate change. In fact, the past 6 years have shown dramatic variation in snowpack, from a high of 174% of normal in 2010-11 to a low of 11% for 2014-15, one of the lowest on record. During this timeframe, we have monitored the stable isotopes of water within the Willamette River twice monthly, and mapped the spatial variation of water isotopes across the basin. Within the Willamette Basin, stable isotopes of water in precipitation vary strongly with elevation and provide a marker for determining the mean elevation from which water in the Willamette River is derived. In winter, when snow accumulates in the mountains, low elevation precipitation (primarily rain) contributes the largest proportion of water to the Willamette River. During summer, when rainfall is scarce and demand for water is the greatest, water in the Willamette River is mainly derived from high elevation snowmelt. Our data indicate that the proportion of water from high elevation decreased with decreasing snowpack. We combine this information with river flow data to estimate the volume reduction related to snowpack reduction during the dry summer. Observed reductions in the contribution of high elevation water to the Willamette River after just 2 years of diminished snowpack indicate that the hydrologic system responds relatively

Integrated assessment of wastewater treatment plant effluent estrogenicity in the Upper Murray River, Australia, using the native Murray rainbowfish (Melanotaenia fluviatilis)

USGS Publications Warehouse

Vajda, Alan M.; Kumar, Anupama; Woods, Marianne; Williams, Mike; Doan, Hai; Tolsher, Peter; Kookana, Rai S.; Barber, Larry B.

2016-01-01

The contamination of major continental river systems by endocrine-active chemicals (EACs) derived from the discharge of wastewater treatment plant (WWTP) effluents can affect human and ecosystem health. As part of a long-term effort to develop a native fish model organism for assessment of endocrine disruption in Australia's largest watershed, the Murray-Darling River Basin, the present study evaluated endocrine disruption in adult males of the native Australian Murray rainbowfish (Melanotaenia fluviatilis) exposed to effluent from an activated sludge WWTP and water from the Murray River during a 28-d, continuous-flow, on-site experiment. Analysis of the WWTP effluent and river water detected estrone and 17β-estradiol at concentrations up to approximately 25 ng L−1. Anti-estrogenicity of effluent samples was detected in vitro using yeast-based bioassays (yeast estrogen screen) throughout the experiment, but estrogenicity was limited to the first week of the experiment. Histological evaluation of the testes indicated significant suppression of spermatogenesis by WWTP effluent after 28 d of exposure. Plasma vitellogenin concentrations and expression of vitellogenin messenger RNA in liver were not significantly affected by exposure to WWTP effluent. The combination of low contaminant concentrations in the WWTP effluent, limited endocrine disrupting effects in the Murray rainbowfish, and high in-stream dilution factors (>99%) suggest minimal endocrine disruption impacts on native Australian fish in the Murray River downstream from the WWTP outfall. 

Size selection from fishways and potential evolutionary responses in a threatened Atlantic salmon population

USGS Publications Warehouse

Maynard, George A.; Kinnison, M.T.; Zydlewski, Joseph D.

2017-01-01

The evolutionary effects of harvest on wild fish populations have been documented around the world; however, sublethal selective pressures can also cause evolutionary changes in phenotypes. For migratory fishes, passage facilities may represent instances of nonlethal selective pressure. Our analysis of 6 years of passage data suggests that certain fish passage facilities on the Penobscot River have been exerting selective pressure against large-bodied, anadromous Atlantic salmon (Salmo salar). At the second and third dams in the river, a 91-cm salmon was 21%–27% and 12%–16% less likely to pass than a 45-cm salmon, respectively. Fish size positively influences egg survival and number and is a heritable trait. Therefore, in a wild-reproducing population, exclusion of large fish from spawning areas may have population-level impacts. In the Penobscot River, most returning adults derive from a hatchery program that collects its broodstock after passing the first dam in the river. Analysis of fork lengths of salmon returning to the Penobscot River from 1978 to 2012 provided mixed support for evolution of size at maturity in different age classes in a pattern that may be expected from interactions with conservation hatchery operations. Additionally, slow-maturing and iteroparous individuals that represent the largest salmon size classes were essentially lost from the population during that time, and Penobscot River fish have shorter fork lengths at maturity than Atlantic salmon in undammed systems.

Ground-Water Budgets for the Wood River Valley Aquifer System, South-Central Idaho, 1995-2004

USGS Publications Warehouse

Bartolino, James R.

2009-01-01

The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Haley, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system which consists of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on ground water for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the ground-water resource. To help address these concerns this report describes a ground-water budget developed for the Wood River Valley aquifer system for three selected time periods: average conditions for the 10-year period 1995-2004, and the single years of 1995 and 2001. The 10-year period 1995-2004 represents a range of conditions in the recent past for which measured data exist. Water years 1995 and 2001 represent the wettest and driest years, respectively, within the 10-year period based on precipitation at the Ketchum Ranger Station. Recharge or inflow to the Wood River Valley aquifer system occurs through seven main sources (from largest to smallest): infiltration from tributary canyons, streamflow loss from the Big Wood River, areal recharge from precipitation and applied irrigation water, seepage from canals and recharge pits, leakage from municipal pipes, percolation from septic systems, and subsurface inflow beneath the Big Wood River in the northern end of the valley. Total estimated mean annual inflow or recharge to the aquifer system for 1995-2004 is 270,000 acre-ft/yr (370 ft3/s). Total recharge for the wet year 1995 and the dry year 2001 is estimated to be 270,000 acre-ft/yr (370 ft3/s) and 220,000 acre-ft/yr (300 ft3/s), respectively. Discharge or outflow from the Wood River Valley aquifer system occurs through five main sources (from largest to smallest): Silver Creek streamflow gain, ground-water pumpage, Big Wood River streamflow gain, direct evapotranspiration from riparian vegetation, and subsurface outflow (treated separately). Total estimated mean 1995-2004 annual outflow or discharge from the aquifer system is 250,000 acre-ft/yr (350 ft3/s). Estimated total discharge is 240,000 acre-ft/yr (330 ft3/s) for both the wet year 1995 and the dry year 2001. The budget residual is the difference between estimated ground-water inflow and outflow and encompasses subsurface outflow, ground-water storage change, and budget error. For 1995-2004, mean annual inflow exceeded outflow by 20,000 acre-ft/yr (28 ft3/s); for the wet year 1995, mean annual inflow exceeded outflow by 30,000 acre-ft/yr (41 ft3/s); for the dry year 2001, mean annual outflow exceeded inflow by 20,000 acre-ft/yr (28 ft3/s). These values represent 8, 13, and 8 percent, respectively, of total outflows for the same periods. It is difficult to differentiate the relative contributions of the three residual components, although the estimated fluctuations between the wet and dry year budgets likely are primarily caused by changes in ground-water storage. The individual components in the wet and dry year ground-water budgets responded in a consistent manner to changes in precipitation and temperature. Although the ground-water budgets for the three periods indicated that ground-water storage is replenished in wet years, statistical analyses by Skinner and others (2007) suggest that such replenishment is not complete and over the long term more water is removed from storage than is replaced. In other words, despite restoration of water to ground-water storage in wet years, changes have occurred in either recharge and (or) discharge to cause ground-water storage to decline over time. Such changes may include, but are not limited to: lining or abandoning canals and ditches, conversion of surface-water irriga

Towards Optimal Operation of the Reservoir System in Upper Yellow River: Incorporating Long- and Short-term Operations and Using Rolling Updated Hydrologic Forecast Information

NASA Astrophysics Data System (ADS)

Si, Y.; Li, X.; Li, T.; Huang, Y.; Yin, D.

2016-12-01

The cascade reservoirs in Upper Yellow River (UYR), one of the largest hydropower bases in China, play a vital role in peak load and frequency regulation for Northwest China Power Grid. The joint operation of this system has been put forward for years whereas has not come into effect due to management difficulties and inflow uncertainties, and thus there is still considerable improvement room for hydropower production. This study presents a decision support framework incorporating long- and short-term operation of the reservoir system. For long-term operation, we maximize hydropower production of the reservoir system using historical hydrological data of multiple years, and derive operating rule curves for storage reservoirs. For short-term operation, we develop a program consisting of three modules, namely hydrologic forecast module, reservoir operation module and coordination module. The coordination module is responsible for calling the hydrologic forecast module to acquire predicted inflow within a short-term horizon, and transferring the information to the reservoir operation module to generate optimal release decision. With the hydrologic forecast information updated, the rolling short-term optimization is iterated until the end of operation period, where the long-term operating curves serve as the ending storage target. As an application, the Digital Yellow River Integrated Model (referred to as "DYRIM", which is specially designed for runoff-sediment simulation in the Yellow River basin by Tsinghua University) is used in the hydrologic forecast module, and the successive linear programming (SLP) in the reservoir operation module. The application in the reservoir system of UYR demonstrates that the framework can effectively support real-time decision making, and ensure both computational accuracy and speed. Furthermore, it is worth noting that the general framework can be extended to any other reservoir system with any or combination of hydrological model(s) to forecast and any solver to optimize the operation of reservoir system.

Rewriting the Landform History of One of Africa's Three Largest Basins

NASA Technical Reports Server (NTRS)

Wilkinson, Justin

2014-01-01

The Kalahari Basin in southern Africa - one of the largest basins in Africa, along with the Congo and Chad basins - has attracted attention since David Livingstone traveled through the area in the 1840s. It is a semiarid desert with a large freshwater swampland known as the Okavango Swamp (150 km radius). This prominent megafan (a fan with radii >100 km), with its fingers of dark green forests projecting into the dun colors of the dunes of the Kalahari semi-desert, has been well photographed by astronauts over the years. The study area in the northern Kalahari basin is centered on the Okavango megafan of northwest Botswana, whose swampland has become well known as an African wildlife preserve of importance to biology and tourism alike. The Okavango River is unusual because it has deposited not one but two megafans along its course: the Okavango megafan and the Cubango megafan. The Okavango megafan is one of only three well-known megafans in Africa. Megafans on Earth were once thought to be rare, but recent research has documented 68 in Africa alone. Eleven megafans, plus three more candidates, have been documented in the area immediately surrounding the Okavango feature. These 11 megafans occupy the flattest and smoothest terrains adjacent to the neighboring upland and stand out as the darkest areas in the roughness map of the area. Megafan terrains occupy at least 200,000 sq km of the study area. The roughness map shown is based on an algorithm used first on Mars to quantify topographic roughness. Research of Earth's flattest terrains is just beginning with the aid of such maps, and it appears that these terrains are analogous to the flattest regions of Mars. Implications: 1. The variability in depositional style in each subbasin may apply Africa-wide: rift megafan length is dominated by rift width, whereas Owambo subbasin megafans are probably controlled by upland basin size; Zambezi subbasin megafans appear more like foreland basin types, with the position of the trunk river controlling size. 2. These perspectives were successfully applied to identify the largest megafan in the group (Cubango), a fan that was sufficiently overprinted by dunes and dry lakelets not to be detectable remotely. Such undertsanding can probably be applied on Mars, where Earth experience suggests megafans ought to exist. 3. Sweep angles of rivers on megafans drastically change the hydrology in some subbasins: when the Cubango and Kunene rivers were oriented to the Etosha Pan, it was probably a permanent water body. Now that the rivers are oriented away from the basin, 93 percent of the discharge area from the pan's northerly (main) source area is gone. 4. Biotic contact between major river systems was probably controlled by megafans situated on divides: various fish species that originated in the Congo basin are now found in the Upper Zambezi R., and vice versa, apparently because of river switching behavior on the Cassai megafan that has mediated migrations both to the south and the north.

Geochemical processes in the Onyx River, Wright Valley, Antarctica: Major ions, nutrients, trace metals

NASA Astrophysics Data System (ADS)

Green, William J.; Stage, Brian R.; Preston, Adam; Wagers, Shannon; Shacat, Joseph; Newell, Silvia

2005-02-01

We present data on major ions, nutrients and trace metals in an Antarctic stream. The Onyx River is located in Wright Valley (77-32 S; 161-34 E), one of a group of ancient river and glacier-carved landforms that comprise the McMurdo Dry Valleys of Antarctica. The river is more than 30 km long and is the largest of the glacial meltwater streams that characterize this relatively ice-free region near the Ross Sea. The complete absence of rainfall in the region and the usually small contributions of glacially derived tributaries to the main channel make this a comparatively simple system for geochemical investigation. Moreover, the lack of human impacts, past or present, provides an increasingly rare window onto a pristine aquatic system. For all major ions and silica, we observe increasing concentrations with distance from Lake Brownworth down to the recording weir near Lake Vanda. Chemical weathering rates are unexpectedly high and may be related to the rapid dissolution of ancient carbonate deposits and to the severe physical weathering associated with the harsh Antarctic winter. Of the nutrients, nitrate and dissolved reactive phosphate appear to have quite different sources. Nitrate is enriched in waters near the Lower Wright Glacier and may ultimately be derived from stratospheric sources; while phosphate is likely to be the product of chemical weathering of valley rocks and soils. We confirm the work of earlier investigations regarding the importance of the Boulder Pavement as a nutrient sink. Dissolved Mn, Fe, Ni, Cu, and Cd are present at nanomolar levels and, in all cases, the concentrations of these metals are lower than in average world river water. We hypothesize that metal uptake and exchange with particulate phases along the course of the river may serve as a buffer for the dissolved load. Concurrent study of these three solute classes points out significant differences in the mechanisms and sites of their removal from the Onyx River.

Suwannee River flow variability 1550-2005 CE reconstructed from a multispecies tree-ring network

NASA Astrophysics Data System (ADS)

Harley, Grant L.; Maxwell, Justin T.; Larson, Evan; Grissino-Mayer, Henri D.; Henderson, Joseph; Huffman, Jean

2017-01-01

Understanding the long-term natural flow regime of rivers enables resource managers to more accurately model water level variability. Models for managing water resources are important in Florida where population increase is escalating demand on water resources and infrastructure. The Suwannee River is the second largest river system in Florida and the least impacted by anthropogenic disturbance. We used new and existing tree-ring chronologies from multiple species to reconstruct mean March-October discharge for the Suwannee River during the period 1550-2005 CE and place the short period of instrumental flows (since 1927 CE) into historical context. We used a nested principal components regression method to maximize the use of chronologies with varying time coverage in the network. Modeled streamflow estimates indicated that instrumental period flow conditions do not adequately capture the full range of Suwannee River flow variability beyond the observational period. Although extreme dry and wet events occurred in the gage record, pluvials and droughts that eclipse the intensity and duration of instrumental events occurred during the 16-19th centuries. The most prolonged and severe dry conditions during the past 450 years occurred during the 1560s CE. In this prolonged drought period mean flow was estimated at 17% of the mean instrumental period flow. Significant peaks in spectral density at 2-7, 10, 45, and 85-year periodicities indicated the important influence of coupled oceanic-atmospheric processes on Suwannee River streamflow over the past four centuries, though the strength of these periodicities varied over time. Future water planning based on current flow expectations could prove devastating to natural and human systems if a prolonged and severe drought mirroring the 16th and 18th century events occurred. Future work in the region will focus on updating existing tree-ring chronologies and developing new collections from moisture-sensitive sites to improve understandings of past hydroclimate in the region.

Trends and comparison of water quality and bottom material of northeastern Arkansas streams, 1974-85, and effects of planned diversions

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

Petersen, J.C.

1990-01-01

Water quality of several rivers in Arkansas was compared using median values at individual water quality stations. Differences were detected in several properties, including common dissolved constituents, alkalinity, nutrients, fecal coliform bacteria, trace metals, pesticides, and sediment. In bottom material, organochlorine pesticides were detected much more frequently than organophosphorus pesticides and were higher in rivers with beds of fine-gradient particles. Time trends were examined using the Seasonal Kendall test. Trends in conductance, sodium adsorption ratio, chloride, phosphorus, and ammonia were usually not detectable. Sulfate concentrations were increasing at approximately one-half of the stations studied while fecal-coliform bacteria concentrations decreased atmore » approximately one-half of the stations. The most potentially detrimental effects upon water quality resulting from surface water diversions were related to increases of common dissolved constituents. From available data, the largest of these increases would be caused by diversion from the Arkansas River. Potential effects not specifically examined include resuspension of bottom materials resulting from construction and operation of the diversion system. Use of some surface waters for artificial recharge of the alluvial aquifer may adversely affect the recharge systems or the aquifer. Possible effects include plugging of the injection well and the aquifer.« less

[Research on the sensitivity of geochemical of underground river in Chongqing Xueyu Cave].

PubMed

Xu, Shang-Quan; Yang, Ping-Heng; Yin, Jian-Jun; Mao, Hai-Hong; Wang, Peng; Zhou, Xiao-Ping

2013-01-01

Quoted geochemical susceptivity index and isosensitive line on geochemical susceptivity, analyzed the data of underground rivers of Xueyu Cave in Chongqing from September 2010 to August 2011, we found that the chemical composition of the underground river was controlled by the bedrock, due to the composition of high concentration of Ca2+ and low concentration of Mg2+. Owing to the effects of the monsoon, water chemistry was different between drought season and rainy season: the value of [Mg2+]/[Ca2+] was 0.018-0.051 in the rainy season, but in dry season the value was 0.038-0.064. The value of [HCO3(-)]/[SO4(2-)] was 4.86-36.62 in the rainy season, and 6.23-46.67 in the dry season. The seasonal change of Karstification made Ca2+ and HCO3(-) become the most sensitive ion. As a result of the special hydrogeological structure in Karat area, rain, surface water and groundwater transformed rapidly, which caused the underground river was sensitive to agricultural activities, especially for Cl- and NO3(-), and their sensitive indices were 0.286 and 0.022 respectively. The influence of tourism activities on the underground river was less than the management. The management work of ecological system should be strengthen in the recharge area, thus the largest economic and environmental benefits in the Karst area could be achieved.

SCIMAP: Modelling Diffuse Pollution in Large River Basins

NASA Astrophysics Data System (ADS)

Milledge, D.; Heathwaite, L.; Lane, S. N.; Reaney, S. M.

2009-12-01

Polluted rivers are a problem for the plants and animals that require clean water to survive. Watershed scale processes can influence instream aquatic ecosystems by delivering fine sediment, solutes and organic matter from diffuse sources. To improve our rivers we need to identify the pollution sources. Models can help us to do this but these rarely address the extent to which risky land uses are hydrologically-connected, and hence able to deliver, to the drainage network. Those that do tend to apply a full hydrological scheme, which is unfeasible for large watersheds. Here we develop a risk-based modelling framework, SCIMAP, for diffuse pollution from agriculture (Nitrate, Phosphate and Fine Sediment). In each case the basis of the analysis is the joint consideration of the probability of a unit of land (25 m2 cell) producing a particular environmental risk and then of that risk reaching the river. The components share a common treatment of hydrological connectivity but differ in their treatment of each pollution type. We test and apply SCIMAP using spatially-distributed instream water quality data for some of the UK’s largest catchments to infer the processes and the associated process parameters that matter in defining their concentrations. We use these to identify a series of risky field locations, where this land use is readily connected to the river system by overland flow.

Nitrogen trends in rivers of the conterminous U.S. in the context of land use and sources

NASA Astrophysics Data System (ADS)

Stets, E.; Sprague, L. A.

2017-12-01

Tremendous efforts have been undertaken to improve the quality of water throughout the United States over the past several decades. The goal of decreasing nitrogen concentrations and fluxes from U.S. rivers has had mixed success and the results are often difficult to quantify. The U.S. Geological Survey has undertaken a study to describe trends in water quality at hundreds of river and stream locations in the conterminous U.S. using a broad data set from national, state, local, and tribal entities. This study represents the largest and most comprehensive analysis of trends in water quality in the U.S. to date. During the period 1992-2012, nitrate (NO3) decreased at 132 sites and increased at 88 sites. Total nitrogen (TN) decreased at 91 sites and increased at 55 sites. The median trend for both NO3 and TN was slightly downward, at -0.04 and -0.11 mg N L-1, respectively. For both NO3 and TN, downward trends were more common in agricultural and urban sites while upward trends were more common at undeveloped sites. Decreases in TN were largest in rivers for which NO3 was a large proportion of TN, which is indicative of significant anthropogenic nitrogen inputs. Across all sites and land use types, trends in TN were highly correlated with trends in NO3, suggesting that changes in NO3 have been a large contributor to TN trends. While overall the largest decreases in NO3 and TN primarily occurred in heavily agricultural areas, decreases were also common in watersheds with higher percentage urban development. Likewise, the largest decreases in NO3 deposition were found in more developed watersheds, suggesting that decreasing atmospheric deposition may be related to NO3 trends at the more developed locations. Despite these improvements, fluxes of nitrogen to the coastal ocean have been largely static over the past several decades, underscoring the continuing need for nutrient management in many parts of the conterminous U.S.

Initial fluvial response to the removal of Oregon's Marmot Dam

Treesearch

Jon J. Major; Jim E. O' Connor; Gordon E. Grant; Kurt R. Spicer; Heather M. Bragg; Abagail Rhode; Dwight Q. Tanner; Chauncey W. Anderson; J. Rose Wallick

2008-01-01

A temporary, 14-meter-high earthen cofferdam standing in place of Marmot Dam was breached on 19 October 2007, allowing the 80-kilometer-long Sandy River to flow freely from Mount Hood, Oregon, to the Columbia River for the first time in nearly 100 years. Marmot Dam is one of the largest dams in the Western United States (in terms of height and volume of stored sediment...

Simulating Multi-Scale Fate and Transport of Mercury from Atmospheric Deposition to Receiving Surface Waters Across and Through the Terrestrial Landscape in a Coastal Plain Watershed (McTier Creek, SC)

EPA Science Inventory

Mercury (Hg) is the toxicant responsible for the largest number of fish advisories across the United States, with 1.1 million river miles under advisory. The processes governing fate and transport of Hg in streams and rivers are not well understood, in large part, because these s...

Fire behavior, weather, and burn severity of the 2007 Anaktuvuk River tundra fire, North Slope, Alaska

Treesearch

Benjamin M. Jones; Crystal A. Kolden; Randi Jandt; John T. Abatzoglu; Frank Urban; Christopher D. Arp

2009-01-01

In 2007, the Anaktuvuk River Fire (ARF) became the largest recorded tundra fire on the North Slope of Alaska. The ARF burned for nearly three months, consuming more than 100,000 ha. At its peak in early September, the ARF burned at a rate of 7000 ha d-1. The conditions potentially responsible for this large tundra fire include modeled record high...

Predicting the aquatic risk of realistic pesticide mixtures to species assemblages in Portuguese river basins.

PubMed

Silva, Emília; Daam, Michiel A; Cerejeira, Maria José

2015-05-01

Although pesticide regulatory tools are mainly based on individual substances, aquatic ecosystems are usually exposed to multiple pesticides from their use on the variety of crops within the catchment of a river. This study estimated the impact of measured pesticide mixtures in surface waters from 2002 and 2008 within three important Portuguese river basins ('Mondego', 'Sado' and 'Tejo') on primary producers, arthropods and fish by toxic pressure calculation. Species sensitivity distributions (SSDs), in combination with mixture toxicity models, were applied. Considering the differences in the responses of the taxonomic groups as well as in the pesticide exposures that these organisms experience, variable acute multi-substance potentially affected fractions (msPAFs) were obtained. The median msPAF for primary producers and arthropods in surface waters of all river basins exceeded 5%, the cut-off value used in the prospective SSD approach for deriving individual environmental quality standards. A ranking procedure identified various photosystem II inhibiting herbicides, with oxadiazon having the relatively largest toxic effects on primary producers, while the organophosphorus insecticides, chlorfenvinphos and chlorpyrifos, and the organochloride endosulfan had the largest effects on arthropods and fish, respectively. These results ensure compliance with European legislation with regard to ecological risk assessment and management of pesticides in surface waters. Copyright © 2015. Published by Elsevier B.V.

Perspective: Towards environmentally acceptable criteria for downstream fish passage through mini hydro and irrigation infrastructure in the Lower Mekong River Basin

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

Baumgartner, Lee J.; Daniel Deng, Z.; Thorncraft, Garry

2014-01-01

Tropical rivers have high annual discharges optimal for hydropower and irrigation development. The Mekong River is one of the largest tropical river systems, supporting a unique mega-diverse fish community. Fish are an important commodity in the Mekong, contributing a large proportion of calcium, protein, and essential nutrients to the diet of the local people and providing a critical source of income for rural households. Many of these fish migrate not only upstream and downstream within main-channel habitats but also laterally into highly productive floodplain habitat to both feed and spawn. Most work to date has focused on providing for upstreammore » fish passage, but downstream movement is an equally important process to protect. Expansion of hydropower and irrigation weirs can disrupt downstream migrations and it is important to ensure that passage through regulators or mini hydro systems is not harmful or fatal. Many new infrastructure projects (<6 m head) are proposed for the thousands of tributary streams throughout the Lower Mekong Basin and it is important that designs incorporate the best available science to protect downstream migrants. Recent advances in technology have provided new techniques which could be applied to Mekong fish species to obtain design criteria that can facilitate safe downstream passage. Obtaining and applying this knowledge to new infrastructure projects is essential in order to produce outcomes that are more favorable to local ecosystems and fisheries.« less

Inventory and Comparison of Floodplain Embankment along Large Rivers

NASA Astrophysics Data System (ADS)

Hudson, Paul

2016-04-01

Flood control is a fundamental human response to flood risk, and floodplain embankment by dike (levee) construction is among the oldest forms of societal impacts to natural systems. Large lowland alluvial valleys are some of Earth's most distinctive environments and represent high levels of geodiversity and biodiversity. Embankment of large lowland alluvial river valleys alters fundamental processes related to floodplain hydrology, sedimentation, and ecology and eventually results in a transformation of the embanked floodplain environment. Since embankment, many large lowland floodplains have been heaviliy modified for floodplain agriculture and include high population densities, increasing flood risk. While there is much discussion about the pros and cons of dike construction and the impact to floodplain environments there is no systematic inventory which documents the magnitude and intensity of floodplain embankment to lowland rivers. In this study we characterize and inventory floodplain embankment along large lowland alluvial valleys. The review includes some of Earth's largest embanked fluvial systems, and primarilly focuses on northern hemisphere rivers in the United States, Europe and Asia. Data sources includes the U.S. National Levee Database, SRTM DEM, recently obtained high resolution satellite imagery, various national topographic map series, and hydrologic data from the published literature. These data are integrated into a GIS framework to facilitate the measurement and characterisation of floodplain embankment. Spatial indices of floodplain embankment are constructed, including the intensity of embankment and how it relates to the natural floodplain and constriction of flooding.

Late Quaternary Stratigraphic Architecture of the Santee River Delta, South Carolina, U.S.A.

NASA Astrophysics Data System (ADS)

Long, J. H.; Hanebuth, T. J. J.

2017-12-01

The Santee River of South Carolina is the second largest river in terms of drainage area and discharge in the eastern United States and forms the only river-fed delta on the country's Atlantic coast. Significant anthropogenic modifications to this system date back to the early 18th century with the extensive clearing of coastal wetland forest for rice cultivation. In the 1940's the construction of large upstream dams permanently altered the discharge of the Santee River. These modifications are likely documented within the sedimentary record of the Santee Delta as episodes of major environmental changes. The Piedmont-sourced Santee River system incised its valley to an estimated depth of 20 m during lower glacial sea level. Sedimentation during the subsequent Holocene transgression and highstand has filled much of this accommodation. The Santee system remains largely under-investigated with only a handful of studies completed in the 1970's and 1980's based on sediment cores and cuttings. Through the use of high frequency seismic profiles (0.5 - 24 kHz), sediment cores, and other field data, we differentiate depositional units, architectural elements, and bounding surfaces with temporal and spatial distributions reflecting the changing morphodynamics of this complex system at multiple scales. These lithosomes are preserved within both modern inshore and offshore settings and were deposited within a range of paralic environments by processes active on fluvial/estuarine bars, floodplains, marshes, tidal flats, spits, beach ridges, and in backbarrier settings. They are bound by surfaces ranging from diastems to regional, polygenetic, low-angle and channel-form erosional surfaces. Detailed descriptions of cores taken from within the upper 6 m of the modern lower delta plain document heterolithic, mixed-energy, organic-rich, largely aggradational sedimentation dating back to at least 5 ka cal BP. Offshore, stacked, sand-rich, progradational packages sit atop heterolithic paleochannel-fill successions contained within a framework of regionally extensive, erosional bounding surfaces. Ongoing work focuses on continued data acquisition and integration of inshore and offshore data sets into a coherent model for the Holocene evolution of the Santee Delta.

Last 900 ka river longprofile changes controlled by Yoro fault activity and glacial sea-level changes, Nobi plain, central Japan

NASA Astrophysics Data System (ADS)

Sugai, T.; Sato, T.

2015-12-01

This paper compared grain size, thickness, and lithological character of ten fluvial gravel layers formed during the glacial sea-level lowstands intervening inner bay mud layers deposited during the interglacial marine transgressional periods since the last 900 ka by integrated analyses of sediment cores including 600 m deep onein the Nobi plain, central Japan. Linkages between river long profile changes and sea-level and climate changes will be discussed. The Nobi basin is one of the representative delta type alluvial lowlands in Japan dominated by longitudinal drainage system named Kiso river system flowing southward from central Japan Alps with abundant water and sediment discharges. The basin bounded by the Yoro fault on the west has been tilted westward by the repetitive faulting activity. The basin stratigraphy and its stacking patterns suggest uniform and rapid subsidence and tilting rates of the basin with the maximum value of 1 mm yr-1 and 10-4 kyr-1 respectively produced by the Yoro fault activity under the W-E compressional regional stress field during the middle and late Quaternary periods. Tephrochronological, paleomagnetic, geochemical, and diatom analyses enabled to identify ten times repeated marine transgression-regression sequences correlated with full glacial-interglacial sea-level changes during the last 900 ka. All of the ten sequence boundaries were characterized by fluvial gravel layers were formed by the Kiso river system. The mean maximum gravel size is proportional to the magnitude of sea level lowering inferred from MIS curve, i.e. gravels deposited in MIS 12 and 16 are the largest, and those in MIS 14 and 8 are the smallest since MIS 16. This suggests that the longitudinal profile of the Kiso river system has been adjusting to the sea level changes and that the steeper longitudinal profile formed in the lower sea level periods can transport larger gravels to the drilling sites. In fact the present river bed gravel size is in proportion with the tractive force and mainly controlled by slope of the rive long-profile.

Water transparency distribution under varied currents in the largest river-connected lake of China.

PubMed

Wang, Hua; Zhao, Yijun; Zhang, Zhizhang; Pang, Yong; Liang, Dongfang

2017-01-01

Water transparency is an important ecological indicator for shallow lakes. The largest shallow lake, Poyang Lake, as well as the most typical river-connected lake in China was selected as the research area. In view of the complicated water-sediment conditions induced by its frequent water exchange with external rivers, the dominant factors driving water transparency were determined against the field investigated data from 2003 to 2013 and a specific driving function was established. A numerical model coupling suspended sediment, Chl-a and chemical oxygen demand was developed and validated, and the spatial water transparency distributions under three typical current structures in Poyang Lake, Gravity-style, Jacking-style and Backflow-style, were quantitatively estimated. The following results stood out: water transparency in the lake varied distinctly with the current status; Backflow-style current was basically characterized by the lowest water transparency, while that under Jacking-style was the highest due to the lower sediment carrying capacity. In some outlying regions in the lake, where the water current is hardly influenced by the mainstream, the water transparency was always kept at a stable level.

Impacts of Water Levels on Breeding Canada Geese and the Methodology for Mitigation and Enhancement in the Flathead Drainage, 1984 Annual Report.

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

Mackey, Dennis L.

1985-01-01

The lower Flathead System Canada Goose Study was initiated to determine population trends and the effects of water level fluctuations on nest and brood habitat on the southern half of Flathead Lake and the lower Flathead River as a result of the operations of Kerr Dam. This report presents data collected during the 1984 field season as part of an ongoing project. Geese used Pablo, Kicking Horse, Ninepipe Reservoirs heavily during late summer and fall. Use of the river by geese was high during the winter, when the reservoirs were frozen, and during the breeding period. Most breeding geese leftmore » the river after broods fledged. Thirteen percent of the artificial tree nest structures on the river were used by nesting geese. Goose nest initiation on the river peaked the last week in March through the first week in April, and hatching peaked the first week in May. Predation was the most significant cause of nest loss on the river, and nest loss by flooding was not observed. Avian predation was the single largest factor contributing to nest loss on the lake. Habitat use was studied in 4 brood areas on the river and 8 brood areas on the lake, and available habitat was assessed for 2 portions of both the lake and the river. Brood habitat use was significantly different from the available habitat in all areas studied. On the lower river, broods used wheat fields, gravel bars, and shrub habitats. On the upper river, coniferous forest and shrub habitats were preferred. On the West Bay of the lake, brood areas consisted primarily of lawns and tall herbaceous habitat, while on the South Bay, marshes dominated the brood areas studied. Water levels on the river and lake affect both accessibility of these areas to brooding geese, and the ecology of the habitats preferred by geese. 43 refs., 24 figs., 31 tabs.« less

Sediment regime constraints on river restoration - An example from the lower Missouri river

USGS Publications Warehouse

Jacobson, R.B.; Blevins, D.W.; Bitner, C.J.

2009-01-01

Dammed rivers are subject to changes in their flow, water-quality, and sediment regimes. Each of these changes may contribute to diminished aquatic habitat quality and quantity. Of the three factors, an altered sediment regime is a particularly unyielding challenge on many dammed rivers. The magnitude of the challenge is illustrated on the Lower Missouri River, where the largest water storage system in North America has decreased the downriver suspended-sediment load to 0.2%–17% of pre-dam loads. In response to the altered sediment regime, the Lower Missouri River channel has incised as much as 3.5 m just downstream of Gavins Point Dam, although the bed has been stable to slightly aggrading at other locations farther downstream. Effects of channel engineering and commercial dredging are superimposed on the broad-scale adjustments to the altered sediment regime.The altered sediment regime and geomorphic adjustments constrain restoration and management opportunities. Incision and aggradation limit some objectives of flow-regime management: In incising river segments, ecologically desirable reconnection of the floodplain requires discharges that are beyond operational limits, whereas in aggrading river segments, small spring pulses may inundate or saturate low-lying farmlands. Lack of sediment in the incising river segment downstream of Gavins Point Dam also limits sustainable restoration of sand-bar habitat for bird species listed under the Endangered Species Act. Creation of new shallow-water habitat for native fishes involves taking sediment out of floodplain storage and reintroducing most or all of it to the river, raising concerns about increased sediment, nutrient, and contaminant loads. Calculations indicate that effects of individual restoration projects are small relative to background loads, but cumulative effects may depend on sequence and locations of projects. An understanding of current and historical sediment fluxes, and how they vary along the river, provides a quantitative basis for defining management constraints and identifying opportunities.

Hydroacoustic mapping to define sedimentation rates and characterize lentic habitats in DeSoto Lake, DeSoto National Wildlife Refuge

USGS Publications Warehouse

Elliott, Caroline M.; Jacobson, Robert B.; Chojnacki, Kimberly A.

2006-01-01

Hydroacoustic tools were used to map depth, elevation, and substrate on DeSoto Lake in March 2006. DeSoto Lake, located on the DeSoto National Wildlife Refuge in Iowa and Nebraska, is one of the largest oxbow lakes of the Missouri River system. It is used by over 500,000 migratory birds each fall and spring and is also an important aquatic resource for anglers. Management concerns at the lake include the effects of erosion and sedimentation, aquatic vegetation establishment, shorebird habitat availability at different lake levels, and fish habitat structure. DeSoto Lake was cut off from the Missouri River in 1960, and the current mapping updates previous lower-resolution bathymetric maps created from lake surveys in 1967 and 1979. The new maps provide managers tools to assess aquatic habitats and provide a baseline for future monitoring of lake sedimentation and erosion.

Napa Earthquake impact on water systems

NASA Astrophysics Data System (ADS)

Wang, J.

2014-12-01

South Napa earthquake occurred in Napa, California on August 24 at 3am, local time, and the magnitude is 6.0. The earthquake was the largest in SF Bay Area since the 1989 Loma Prieta earthquake. Economic loss topped $ 1 billion. Wine makers cleaning up and estimated the damage on tourism. Around 15,000 cases of lovely cabernet were pouring into the garden at the Hess Collection. Earthquake potentially raise water pollution risks, could cause water crisis. CA suffered water shortage recent years, and it could be helpful on how to prevent underground/surface water pollution from earthquake. This research gives a clear view on drinking water system in CA, pollution on river systems, as well as estimation on earthquake impact on water supply. The Sacramento-San Joaquin River delta (close to Napa), is the center of the state's water distribution system, delivering fresh water to more than 25 million residents and 3 million acres of farmland. Delta water conveyed through a network of levees is crucial to Southern California. The drought has significantly curtailed water export, and salt water intrusion reduced fresh water outflows. Strong shaking from a nearby earthquake can cause saturated, loose, sandy soils liquefaction, and could potentially damage major delta levee systems near Napa. Napa earthquake is a wake-up call for Southern California. It could potentially damage freshwater supply system.

Urban sewage lipids in the suspended particulate matter of a coral reef under river influence in the South West Gulf of Mexico.

PubMed

Carreón-Palau, Laura; Parrish, Christopher C; Pérez-España, Horacio

2017-10-15

Nutritional quality of suspended particulate matter (SPM) and the degree of human fecal pollution in the largest coral reef system in the southwest Gulf of Mexico were evaluated using lipid classes, fatty acids (FA) and sterols in the dry and rainy seasons. High proportions of triacylglycerols and saturated and monounsaturated FA were detected in the SPM however it was considered poor quality because it had low proportions of highly unsaturated FA which can be used to determine production of marine biogenic material of dietary value to pelagic and benthic organisms. Urban sewage organic carbon was traced with coprostanol. The reference value of coprostanol from the point source of pollution was set using two samples from a sewage treatment plant processing waste from >140,000 people near the coral reef system, and it was contrasted with one river station and nine marine stations including six coral reefs. The concentration of coprostanol in the SPM was 3621 ± 98 ng L -1 comprising 26% of total sterols. During the dry season, the river was contaminated upstream with human feces as evidenced by coprostanol at 1823 ng L -1 , the 5β-coprostanol: cholesterol ratio at 0.5, and 5β-coprostanol: [5α-cholestanol+5β-coprostanol] at 0.7. In contrast, marine stations had concentrations of coprostanol lower than a suggested regulation limit for tropical marine coastal waters (30 ng L -1 ), ranging between 6 and 28 ng L -1 . During the rainy season a dilution effect was detected in the river, however significantly higher concentrations of coprostanol in the marine stations were detected ranging between 15 and 215 ng L -1 , higher than the tentative tropical regulation range (30-100 ng L -1 ). Among the reefs, the nearshore one, 14.3 km from the treatment plant, was more exposed to human-fecal pollution, and offshore reefs, >17.3 km from the plant, had a lower degree of contamination. Finally, only three stations were clearly uncontaminated during both seasons including two reefs in the south located 21.8 and 35.6 km from the plant, with no presence of coprostanol. Contamination in the rainy season likely comes from a village with untreated sewage located 9.3-32 km from the reefs, and from the second largest Mexican river flowing into the Gulf of Mexico which has a watershed covering three states with lower than average sewage treatment. Inclusion of coprostanol monitoring could be a key factor in the management of this coral reef system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydraulic characterization of the middle reach of the Congo River

NASA Astrophysics Data System (ADS)

O'Loughlin, F.; Trigg, M. A.; Schumann, G. J.-P.; Bates, P. D.

2013-08-01

The middle reach of the Congo remains one of the most difficult places to access, with ongoing conflicts and a lack of infrastructure. This has resulted in the Congo being perhaps the least understood large river hydraulically, particularly compared to the Amazon, Nile, or Mississippi. Globally the Congo River is important; it is the largest river in Africa and the basin contains some of the largest areas of tropical forests and wetlands in the world, which are important to both the global carbon and methane cycles. This study produced the first detailed hydraulic characterization of the middle reach, utilizing mostly remotely sensed data sets. Using Landsat imagery, a 30 m resolution water-mask was created for the middle reach, from which effective river widths and the number of channels and islands were determined. Water surface slopes were determined using ICESat observations for three different periods during the annual flood pulse, and while the overall slope calculated was similar to previous estimates, greater spatial variability was identified. We find that the water surface slope varies markedly in space but relatively little in time and that this appears to contrast with the Amazon where previous studies indicate that time and spatial variations are of equal magnitude. Five key hydraulic constraints were also identified, which play an important role in the overall dynamics of the Congo. Finally, backwater lengths were approximated for four of these constraints, with the results showing that at high water, over a third of the middle reach is affected by backwater effects.

U isotopes distribution in the Lower Rhone River and its implication on radionuclides disequilibrium within the decay series.

PubMed

Zebracki, Mathilde; Cagnat, Xavier; Gairoard, Stéphanie; Cariou, Nicolas; Eyrolle-Boyer, Frédérique; Boulet, Béatrice; Antonelli, Christelle

2017-11-01

The large rivers are main pathways for the delivery of suspended sediments into coastal environments, affecting the biogeochemical fluxes and the ecosystem functioning. The radionuclides from 238 U and 232 Th-series can be used to understand the dynamic processes affecting both catchment soil erosion and sediment delivery to oceans. Based on annual water discharge the Rhone River represents the largest river of the Mediterranean Sea. The Rhone valley also represents the largest concentration in nuclear power plants in Europe. A radioactive disequilibrium between particulate 226 Ra (p) and 238 U (p) was observed in the suspended sediment discharged by the Lower Rhone River (Eyrolle et al. 2012), and a fraction of particulate 234 Th was shown to derive from dissolved 238 U (d) (Zebracki et al. 2013). This extensive study has investigated the dissolved U isotopes distribution in the Lower Rhone River and its implication on particulate radionuclides disequilibrium within the decay series. The suspended sediment and filtered river waters were collected at low and high water discharges. During the 4-months of the study, two flood events generated by the Rhone southern tributaries were monitored. In river waters, the total U (d) concentration and U isotopes distribution were obtained through Q-ICP-MS measurements. The Lower Rhone River has displayed non-conservative U-behavior, and the variations in U (d) concentration between southern tributaries were related to the differences in bedrock lithology. The artificially occurring 236 U was detected in the Rhone River at low water discharges, and was attributed to the liquid releases from nuclear industries located along the river. The ( 235 U/ 238 U) (d) activity ratio (=AR) in river waters was representative of the 235 U natural abundance on Earth. The ( 226 Ra/ 238 U) (p) AR in suspended sediment has indicated a radioactive disequilibrium (average 1.3 ± 0.1). The excess of 234 Th in suspended sediment =( 234 Th xs(p) ) was apparent solely at low water discharges. The activity of 234 Th xs(p) was calculated through gamma measurements and ranged from unquantifiable to 56 ± 14 Bq kg -1 . The possibility of using 234 Th as a tracer for the suspended sediment dynamics in large Mediterranean river was then discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Earth observations taken during the STS-59 mission

NASA Image and Video Library

1994-04-16

STS059-90-098 (9-20 April 1994) --- Ice-covered Lake Baikal, in Siberia, is about 400 miles long within a major rift valley. The water surface is 455 meters above sea level, but the bottom is 1,295 meters below sea level; the lake represents the largest body of fresh water in the world, except for the Antarctic and Greenland ice sheets. A tributary, the Senusi River, has built a delta on the east side. The Angara River exits the lake to the northwest; the city of Irkutsk is under the small, rippled cloud bank that crosses the river. Hasselblad camera.

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

NASA Astrophysics Data System (ADS)

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

2015-12-01

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

The economic value of Trinity River water

USGS Publications Warehouse

Douglas, A.J.; Taylor, J.G.

1999-01-01

The Trinity River, largest tributary of the Klamath River, has its head-waters in the Trinity Alps of north-central California. After the construction of Trinity Dam in 1963, 90% of the Trinity River flow at Lewiston was moved to the Sacramento River via the Clear Creek Tunnel, a manmade conduit. Hydropower is produced at four installations along the route of Trinity River water that is diverted to the Sacramento River, and power production at three of these installations would diminish if no Trinity River water were diverted to the Sacramento River. After Trinity River water reaches the Sacramento River, it flows toward the Sacramento-San Joaquin Delta and San Francisco Bay. Trinity River water is pumped via Bureau of Reclamation canals and pumps to the northern San Joaquin Valley, where it is used for irrigated agriculture. The social cost of putting more water down the Trinity River is the sum of the value of the foregone consumer surplus from hydropower production as well as the value of the foregone irrigation water. Sharply diminished instream flows have also severely affected the size and robustness of Trinity River salmon, steelhead, shad and sturgeon runs. Survey data were used to estimate the non-market benefits of augmenting Trinity River instream flows by letting more water flow down the Trinity and moving less water to the Sacramento River. Preservation benefits for Trinity River instream flows and fish runs are $803 million per annum for the scenario that returns the most water down the Trinity River, a value that greatly exceeds the social cost estimate.The Trinity River, largest tributary of the Klamath River, has its headwaters in the Trinity Alps of north-central California. After the construction of Trinity Dam in 1963, 90% of the Trinity River flow at Lewiston was moved to the Sacramento River via the Clear Creek Tunnel, a manmade conduit. Hydropower is produced at four installations along the route of Trinity River water that is diverted to the Sacramento River, and power production at three of these installations would diminish if no Trinity River water were diverted to the Sacramento River. After Trinity River water reaches the Sacramento River, it flows toward the Sacramento-San Joaquin Delta and San Francisco Bay. Trinity River water is pumped via Bureau of Reclamation canals and pumps to the northern San Joaquin Valley, where it is used for irrigated agriculture. The social cost of putting more water down the Trinity River is the sum of the value of the foregone consumer surplus from hydropower production as well as the value of the foregone irrigation water. Sharply diminished instream flows have also severely affected the size and robustness of Trinity River salmon, steelhead, shad and sturgeon runs. Survey data were used to estimate the non-market benefits of augmenting Trinity River instream flows by letting more water flow down the Trinity and moving less water to the Sacramento River. Preservation benefits for Trinity River instream flows and fish runs are $803 million per annum for the scenario that returns the most water down the Trinity River, a value that greatly exceeds the social cost estimate.

Delhi, India

NASA Image and Video Library

2008-01-17

Delhi is the second largest metropolis in India, with a population of 16 million and is located in northern India along the banks of the Yamuna River. This image was acquired by NASA Terra satellite on September 22, 2003.

Hydrology and ecology of the Apalachicola River, Florida : a summary of the river quality assessment

USGS Publications Warehouse

Elder, John F.; Flagg, Sherron D.; Mattraw, Harold C.

1988-01-01

During 1979-81, the U.S. Geological Survey conducted a large-scale study of the Apalachicola River in northwest Florida, the largest and one of the most economically important rivers in the State. Termed the Apalachicola River Quality Assessment, the study emphasized interrelations among hydrodynamics, the flood-plain forest, and the nutrient-detritus flow through the river system to the estuary. This report summarizes major findings of the study. Data on accumulation of toxic substances in sediments and benthic organisms in the river were also collected. Because of the multiple uses of the Apalachicola River system, there are many difficult management decisions. The river is a waterway for shipping; hence there is an economic incentive for modification to facilitate movement of barge traffic. Such modifications include the proposed construction of dams, levees, bend easings, and training dikes; ditching and draining in the flood plain; and dredging and snagging in the river channel. The river is also recognized as an important supplier of detritus, nutrients, and freshwater to the Apalachicola Bay, which maintains an economically important shellfish industry. The importance of this input to the bay creates an incentive to keep the river basin in a natural state. Other values, such as timber harvesting, recreation, sport hunting, nature appreciation, and wildlife habitat, add even more to the difficulty of selecting management strategies. Water and nutrient budgets based on data collected during the river assessment study indicate the relative importance of various inputs and outflows in the system. Waterflow is controlled primarily by rainfall in upstream watersheds and is not greatly affected by local precipitation, ground-water exchanges, or evapotranspiration in the basin. On an annual basis, the total nutrient inflow to the system is nearly equal in quantity to total outflow, but there is a difference between inflow and outflow in the chemical and physical forms in which the nutrients are carried. The flood plain tends to be a net importer of soluble inorganic nutrients and a net exporter of particulate organic material. Analysis of long-term records shows that dam construction in the upstream watersheds and at the Apalachicola headwaters has had little effect on the total annual waterflow but has probably suppressed low-flow extremes. Other effects include riverbed degradation and channelization which have to do with alteration of the habitat for aquatic biota and changes in flood-plain vegetation. Whatever management decisions are made should take into account the impact on the natural flooding cycle. Flooding is crucial to the present flood-plain plant community and to the production, decomposition, and transport of organic material from that community. Permanent, substantial changes in the natural flooding cycle would be likely to induce concomitant changes in the flood-plain environment and in the nutrient and detritus yield to the estuary.

Braided river flow and invasive vegetation dynamics in the Southern Alps, New Zealand.

PubMed

Caruso, Brian S; Edmondson, Laura; Pithie, Callum

2013-07-01

In mountain braided rivers, extreme flow variability, floods and high flow pulses are fundamental elements of natural flow regimes and drivers of floodplain processes, understanding of which is essential for management and restoration. This study evaluated flow dynamics and invasive vegetation characteristics and changes in the Ahuriri River, a free-flowing braided, gravel-bed river in the Southern Alps of New Zealand's South Island. Sixty-seven flow metrics based on indicators of hydrologic alteration and environmental flow components (extreme low flows, low flows, high flow pulses, small floods and large floods) were analyzed using a 48-year flow record. Changes in the areal cover of floodplain and invasive vegetation classes and patch characteristics over 20 years (1991-2011) were quantified using five sets of aerial photographs, and the correlation between flow metrics and cover changes were evaluated. The river exhibits considerable hydrologic variability characteristic of mountain braided rivers, with large variation in floods and other flow regime metrics. The flow regime, including flood and high flow pulses, has variable effects on floodplain invasive vegetation, and creates dynamic patch mosaics that demonstrate the concepts of a shifting mosaic steady state and biogeomorphic succession. As much as 25 % of the vegetation cover was removed by the largest flood on record (570 m(3)/s, ~50-year return period), with preferential removal of lupin and less removal of willow. However, most of the vegetation regenerated and spread relatively quickly after floods. Some flow metrics analyzed were highly correlated with vegetation cover, and key metrics included the peak magnitude of the largest flood, flood frequency, and time since the last flood in the interval between photos. These metrics provided a simple multiple regression model of invasive vegetation cover in the aerial photos evaluated. Our analysis of relationships among flow regimes and invasive vegetation cover has implications for braided rivers impacted by hydroelectric power production, where increases in invasive vegetation cover are typically greater than in unimpacted rivers.

Canada's Fraser River Basin transitioning from a nival to a hybrid system in the late 20th century

NASA Astrophysics Data System (ADS)

Kang, D. H.; Gao, H.; Shi, X.; Dery, S. J.

2014-12-01

The Fraser River Basin (FRB) is the largest river draining to the Pacific Ocean in British Columbia (BC), Canada, and it provides the world's most abundant salmon populations. With recent climate change, the shifting hydrologic regime of the FRB is evaluated using hydrological modeling results over the period 1949 to 2006. To quantify the contribution of snowmelt to runoff generation, the ratio RSR, defined as the division of the sum of the snowmelt across the watershed by the integrated runoff over the water year, is employed. Modeled results for RSR at Hope, BC — the furthest downstream hydrometric station of the FRB — show a significant decrease (from 0.80 to 0.65) in the latter part of the 20th century. RSR is found to be mainly suppressed by a decrease of the snowmelt across the FRB with a decline with 107 mm by 26 % along the simulation period. There is also a prominent shift in the timing of streamflow, with the spring freshet at Hope, BC advancing 30 days followed by reduced summer flows for over two months. The timing of the peak spring freshet becomes even earlier when moving upstream of the FRB owing to short periods of time after melting from the snow source to the rivers.

Hydrological studies of the historical and palaeoflood events on the middle Yihe River, China

NASA Astrophysics Data System (ADS)

Hu, Guiming; Huang, Chun Chang; Zhou, Yali; Pang, Jiangli; Zha, Xiaochun; Guo, Yongqiang; Zhang, Yuzhu; Zhao, Xueru

2016-12-01

Palaeo-hydrological and sedimentary investigations were carried out in the Longmenxia Gorge of the middle Yihe River. Five bedsets of flood slackwater deposits (SWD) were found interbedded into Holocene aeolian loess-soil profiles in the river bank at the Longmenxia site. They were identified as the deposits of the suspended sediment load during the extreme flood events of the Holocene. The minimum flood peak discharges were estimated to be 12, 300-15, 300 m3/s using the slope-area method. These are about twice the largest gauged record (7180 m3/s) that has occurred since 1937. These flood events occurred at 3100-3000 a B.P., 1800-1700 a B.P., 700-550 a B.P. and 350-250 a B.P., as dated by optically stimulated luminescence (OSL) in combination with stratigraphic correlation, to which may be added the recorded events of the 223 and 1761 CE floods. These were associated with Holocene monsoonal shifts and abrupt climatic events. This research not only provides palaeoflood discharge estimates on the middle Yihe River, but also provides important data for understanding interactions between regional hydro-climatic systems and global climate change in humid and semi-humid monsoonal regions, such as China.

Remote sensing of cloud distributions over the Bayanhar Mountains - Watershed of the Yangtze and Yellow rivers

NASA Technical Reports Server (NTRS)

Hung, R. J.; Liu, J. M.; Dodge, J. C.; Smith, R. E.

1986-01-01

Although the two largest rivers in China originate in the same region separated only by the Bayanhar Mountains as a watershed, the Yangtze and Yellow rivers behave in quite different ways. Most of the warm and humid air currents from the Arabian sea and the Bay of Bengal are blocked by the Bayanhar Mountains. As a result the amount of water in the Yellow River is only 5 percent of that in the Yangtze river. Based on the cloud coverage area and the cloud volumetric distributions, and also the thickness above 9.4 km of the cumulus clouds located north and south of the Bayanhar Mountains from the geosynchronous satellite infrared imagery, the results suggest that a more detailed investigation is warranted in the hope that the proper modification of cumuli north of the Bayanhar Mountains would enhance the rainfall over the fountainhead of the Yellow River.

Suspended-sediment and fresh-water discharges in the Ob and Yenisey rivers, 1960-1988

USGS Publications Warehouse

Meade, R.H.; Bobrovitskaya, N.N.; Babkin, V.I.

2000-01-01

Of the world's great rivers, the Ob and Yenisey rank among the largest suppliers of fresh water and among the smallest suppliers of suspended sediment to the coastal ocean. Sediment in the middle reaches of the rivers is mobilized from bordering terraces and exchanged between channels and flood plains. Sediment in the lower reaches of these great rivers is deposited and stored (permanently, on a millennial time scale) in flood plains. Sediment discharges, already small under natural conditions, are diminished further by large manmade reservoirs that trap significant proportions of the moving solids. The long winter freeze and sudden spring breakup impose a peakedness in seasonal water runoff and sediment discharge that contrasts markedly with that in rivers of the tropics and more temperate climates. Very little sediment from the Ob and Yenisey rivers is being transported to the open waters of the Arctic Ocean under present conditions.

Satellite remote sensing of water resources in the Yangtze and Yellow Rivers of China based on infrared imagery of cloud distributions

NASA Technical Reports Server (NTRS)

Hung, R. J.; Dodge, James C.

1990-01-01

Although the two largest rivers in China originate in the same region, separated only by the Bayanhar Mountains as a watershed, the Yangtze and Yellow Rivers behave in quite different ways. Most of the warm and humid air currents from the Arabian Sea and Bay of Bengal are blocked by the Bayanhar Mountains. As a result, the amount of water in the Yellow River is only 5 percent of that in the Yangtze River. Based on the cloud coverage area and the cloud volumetric distributions, and also the thickness above 9.4 kms of the cumulus clouds located north and south of the Bayanhar Mountains, from GEO satellite IR imagery, the results suggest that a more detailed investigation is warranted in the hope that the proper modification of cumuli north of the Bayanhar Mountains would enhance the rainfall over the fountainhead of the Yellow River.

Utilization of protein expression profiles as indicators of environmental impairment of smallmouth bass (Micropterus dolomieu) from the Shenandoah River, Virginia, USA.

PubMed

Ripley, Jennifer; Iwanowicz, Luke; Blazer, Vicki; Foran, Christy

2008-08-01

The Shenandoah River (VA, USA), the largest tributary of the Potomac River (MD, USA) and an important source of drinking water, has been the site of extensive fish kills since 2004. Previous investigations indicate environmental stressors may be adversely modulating the immune system of smallmouth bass (Micropterus dolomieu) and other species. Anterior kidney (AK) tissue, the major site of blood cell production in fish, was collected from smallmouth bass at three sites along the Shenandoah River. The tissue was divided for immune function and proteomics analyses. Bactericidal activity and respiratory burst were significantly different between North Fork and mainstem Shenandoah River smallmouth bass, whereas South Fork AK tissue did not significantly differ in either of these measures compared with the other sites. Cytotoxic cell activity was highest among South Fork and lowest among North Fork AK leukocytes. The composite two-dimension gels of the North Fork and mainstem smallmouth bass AK tissues contained 584 and 591 spots, respectively. South Fork smallmouth bass AK expressed only 335 proteins. Nineteen of 50 proteins analyzed by matrix-assisted laser desorption ionization-time of flight were successfully identified. Three of the four identified proteins with increased expression in South Fork AK tissue were involved in metabolism. Seven proteins exclusive to mainstem and North Fork smallmouth bass AK and expressed at comparable abundances serve immune and stress response functions. The proteomics data indicate these fish differ in metabolic capacity of AK tissue and in the ability to produce functional leukocytes. The variable responses of the immune function assays further indicate disruption to the immune system. Our results allow us to hypothesize underlying physiological changes that may relate to fish kills and suggest relevant contaminants known to produce similar physiological disruption.

Utilization of protein expression profiles as indicators of environmental impairment of smallmouth bass (Micropterus dolomieu) from the Shenandoah River, Virginia, USA

USGS Publications Warehouse

Ripley, J.; Iwanowicz, L.; Blazer, V.; Foran, C.

2008-01-01

The Shenandoah River (VA, USA), the largest tributary of the Potomac River (MD, USA) and an important source of drinking water, has been the site of extensive fish kills since 2004. Previous investigations indicate environmental stressors may be adversely modulating the immune system of smallmouth bass (Micropterus dolomieu) and other species. Anterior kidney (AK) tissue, the major site of blood cell production in fish, was collected from smallmouth bass at three sites along the Shenandoah River. The tissue was divided for immune function and proteomics analyses. Bactericidal activity and respiratory burst were significantly different between North Fork and mainstem Shenandoah River smallmouth bass, whereas South Fork AK tissue did not significantly differ in either of these measures compared with the other sites. Cytotoxic cell activity was highest among South Fork and lowest among North Fork AK leukocytes. The composite two-dimension gels of the North Fork and mainstem smallmouth bass AK tissues contained 584 and 591 spots, respectively. South Fork smallmouth bass AK expressed only 335 proteins. Nineteen of 50 proteins analyzed by matrix-assisted laser desorption ionization-time of flight were successfully identified. Three of the four identified proteins with increased expression in South Fork AK tissue were involved in metabolism. Seven proteins exclusive to mainstem and North Fork smallmouth bass AK and expressed at comparable abundances serve immune and stress response functions. The proteomics data indicate these fish differ in metabolic capacity of AK tissue and in the ability to produce functional leukocytes. The variable responses of the immune function assays further indicate disruption to the immune system. Our results allow us to hypothesize underlying physiological changes that may relate to fish kills and suggest relevant contaminants known to produce similar physiological disruption. ?? 2008 SETAC.

NOx reduction through combustion optimization at PEPCO`s Potomac River Station

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

Cramer, D.S.; Williams, S.E.; Watkins, J.T.

1995-06-01

This paper describes the work done under EPRI Project RP 3383 at Potomac River Station to reduce NOx emissions by adjusting boiler controls. it details the method followed by PEPCO and Lehigh engineers to achieve a 35% reduction in average NOx emissions over a one-month extended test. Parameters that had the largest effect on NOx are discussed. A description of instruments installed to better monitor and control combustion is included.

Development of Predictive Relationships for Flood Hazard Assessments in Ungaged Basins

DTIC Science & Technology

2016-02-01

Hydrological Analysis (GSSHA) model (Downer and Ogden 2004) was deployed in megascale for ungaged basins of the Philippine Islands . The GSSHA...et al. [1988]). STUDY AREA: Two megascale catchments in the Philippine Islands were considered in this study. No stream gage data exists for either...imagery. The Cagayan River Basin on Luzon Island (Figure 1[a]) is the largest river in the Philippines with a drainage area of 27,280 km2

Preliminary Characterization of Organic Geochemistry in the Fly-Strickland River System, Papua New Guinea

NASA Astrophysics Data System (ADS)

Alin, S. R.; Aalto, R.; Remington, S. M.; Richey, J. E.

2003-12-01

The Fly-Strickland fluvial dispersal system comprises one of the largest river basins in tropical Oceania, ranking among the top 20 rivers in the world for water and sediment discharge. From the New Guinea highlands, these rivers flow >1000 km across lowland tropical floodplains to the Gulf of Papua, with an average annual depth of runoff 100 times that of the Amazon. Within the system, the Strickland has greater sediment discharge and a steeper gradient than the Fly, providing an opportunity to investigate biogeochemical differences associated with particulate flux. For eight lowland sites across the Fly-Strickland river system, we analyzed water and suspended sediment (SS) samples for an initial survey of various carbon cycle parameters. Both the Fly and Strickland Rivers were strongly supersaturated with carbon dioxide (2008-10,479 uatm CO2) and undersaturated with oxygen (1.10-5.48 mg/l O2), with the Fly having higher CO2 and lower O2 concentrations than the Strickland River. These pCO2 and O2 concentrations are comparable to and lower than (respectively) typical values in the Amazon. Measured Fly-Strickland alkalinity values fell in the range of 0.893-1.888 meq, and pH measurements were neutral to slightly alkaline (6.916-7.852). In a sample from a sediment-impoverished tributary from Lake Murray to the Strickland (Herbert R.), pH was neutral (7.060), and alkalinity and pCO2 had their lowest observed values at 0.234 meq and 1407 uatm, respectively. Nutrient concentrations were generally higher in the Strickland ([NO3]=3.36+/-0.69 uM, [PO4]=0.09+/-0.10 uM, and [Si(OH)4]=176.6+/-41.7 uM) than in the Fly River ([NO3]=1.09+/-0.04 uM, [PO4]=0.01+/-0.01 uM, and [Si(OH)4]=110.6+/-4.8 uM). NO3 and PO4 concentrations in the Fly-Strickland river system were lower than in the Amazon, and silicate was comparable. SS concentrations were higher in the Strickland than in the Fly (49.4-231.1 mg/l vs. 19.5-59.6 mg/l). Coarse particulates were organic-poor in the Fly and Strickland rivers, with <1% organic carbon (OC). Fine particulates contained more OC in the Fly (2.32-9.03%) than in the Strickland (0.99-3.08%). In aggregate, the average OC concentration of Fly-Strickland river SS samples is 3.75+/-3.07%, which is substantially higher than %OC values measured in fine particulates in the Amazon. C/N ratios for fine particulate organic matter (FPOM) are higher in the Fly (13.0-24.1) than in the Strickland (9.5-14.4), suggesting a greater contribution of N-poor, terrestrial organics to the Fly River. FPOM δ 13C values in the Fly are more depleted (-31.1--30.3‰ ) than in the Strickland River (-29.6--28.4‰ ). We intend to estimate the total biogeochemical fluxes associated with these reported concentrations. Collectively, these preliminary data on carbon cycling in the Fly and Strickland rivers suggest that this fluvial dispersal system outgases a substantial volume of CO2 each year relative to its area, much like the Amazon River. However, in contrast to the Amazon, where the majority of the sediment from the Andes is trapped in sub-aerial, intra-cratonal basins, most fluviatile sediment is advected beyond the Fly River mouth. Therefore, due to the higher organic content of the fine suspended sediment in this river system, it seems probable that a relatively greater export and burial flux of organic carbon may occur within the delta and shelf deposits of the Gulf of Papua.

Terrestrial Contributions to the Aquatic Food Web in the Middle Yangtze River

PubMed Central

Wang, Jianzhu; Gu, Binhe; Huang, Jianhui; Han, Xingguo; Lin, Guanghui; Zheng, Fawen; Li, Yuncong

2014-01-01

Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD) in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish) at an upstream constricted-channel site (Luoqi), a midstream estuarine site (Huanghua) and a near dam limnetic site (Maoping) of the TGD were collected for stable isotope (δ13C and δ15N) and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping), particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies. PMID:25047656

Derivation and Application of Idealized Flow Conditions in River Network Simulation

NASA Astrophysics Data System (ADS)

Afshari Tork, S.; Fekete, B. M.

2015-12-01

Stream flow information is essential for many applications across broad range of scales, e.g. global water balances, engineering design, flood forecasting, environmental management, etc. Quantitative assessment of flow dynamics of natural streams, requires detailed knowledge of all the geometrical and geophysical variables (e.g. bed-slope, bed roughness, etc.) along river reaches. Simplifying the river bed geometries could reduce both the computational burden implementing flow simulations and challenges in assembling the required data, especially for large domains. Average flow conditions expressed as empirical "at-a-station" hydraulic geometry relationships between key channel components, (i.e. water depth, top-width, flow velocity, flow area against discharge) have been studied since 60's. Recent works demonstrated that power-function as idealized riverbed geometry whose parameters are correlated to those of exponential relationship between mean water depth and top-width, are consistent with empirical "at-a-station" relations.US Geological Surveys' National Water Information System web-interface provides huge amount of river discharge and corresponding stage height data from several thousands of streamflow monitoring stations over United States accompanied by river survey summaries providing additional flow informations (width, mean velocity, cross-sectional area). We conducted a series of analyses to indentify consistent data daily monitoring and corresponding survey records that are suitable to refine our current understanding of how the "at-a-station" properties of river channels relate to channel forming characteristics (e.g. riverbed slope, flow regime, geology, etc.). The resulting ~1,200 actively operating USGS stations with over ~225,000 corresponding survery records (almost 200 survey per gauge on average) is the largest river survey database ever studied in the past.Our presentation will show our process assembling our river monitoring and survey data base and we will present our first results translating "at-a-station" relations into he hydraulic geometry of river channels based on idealized power-law riverbed geometries. We also will also present a series of application (e.g. improved flow rounting, simplyfied river surveying).

Terrestrial contributions to the aquatic food web in the middle Yangtze River.

PubMed

Wang, Jianzhu; Gu, Binhe; Huang, Jianhui; Han, Xingguo; Lin, Guanghui; Zheng, Fawen; Li, Yuncong

2014-01-01

Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD) in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish) at an upstream constricted-channel site (Luoqi), a midstream estuarine site (Huanghua) and a near dam limnetic site (Maoping) of the TGD were collected for stable isotope (δ13C and δ15N) and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping), particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies.

Life-history and habitat features influence the within-river genetic structure of Atlantic salmon.

PubMed

Vähä, Juha-Pekka; Erkinaro, Jaakko; Niemelä, Eero; Primmer, Craig R

2007-07-01

Defining populations and identifying ecological and life-history characteristics affecting genetic structure is important for understanding species biology and hence, for managing threatened or endangered species or populations. In this study, populations of the world's largest indigenous Atlantic salmon (Salmo salar) stock were first inferred using model-based clustering methods, following which life-history and habitat variables best predicting the genetic diversity of populations were identified. This study revealed that natal homing of Atlantic salmon within the Teno River system is accurate at least to the tributary level. Generally, defining populations by main tributaries was observed to be a reasonable approach in this large river system, whereas in the mainstem of the river, the number of inferred populations was fewer than the number of distinct sampling sites. Mainstem and headwater populations were genetically more diverse and less diverged, while each tributary fostered a distinct population with high genetic differentiation and lower genetic diversity. Population structure and variation in genetic diversity among populations were poorly explained by geographical distance. In contrast, age-structure, as estimated by the proportion of multisea-winter spawners, was the most predictive variable in explaining the variation in the genetic diversity of the populations. This observation, being in agreement with theoretical predictions, emphasizes the essence of large multisea-winter females in maintaining the genetic diversity of populations. In addition, the unique genetic diversity of populations, as estimated by private allele richness, was affected by the ease of accessibility of a site, with more difficult to access sites having lower unique genetic diversity. Our results show that despite this species' high capacity for migration, tributaries foster relatively closed populations with little gene flow which will be important to consider when developing management strategies for the system.

Analysis of trends of water quality and streamflow in the Blackstone, Branch, Pawtuxet, and Pawcatuck Rivers, Massachusetts and Rhode Island, 1979 to 2015

USGS Publications Warehouse

Savoie, Jennifer G.; Mullaney, John R.; Bent, Gardner C.

2017-02-21

Trends in long-term water-quality and streamflow data from six water-quality-monitoring stations within three major river basins in Massachusetts and Rhode Island that flow into Narragansett Bay and Little Narragansett Bay were evaluated for water years 1979–2015. In this study, conducted by the U.S. Geological Survey in cooperation with the Rhode Island Department of Environmental Management, the Rhode Island Water Resources Board, and the U.S. Environmental Protection Agency, water-quality and streamflow data were evaluated with a Weighted Regressions on Time, Discharge, and Season smoothing method, which removes the effects of year-to-year variation in water-quality conditions due to variations in streamflow (discharge). Trends in annual mean, annual median, annual maximum, and annual 7-day minimum flows at four continuous streamgages were evaluated by using a time-series smoothing method for water years 1979–2015.Water quality at all monitoring stations changed over the study period. Decreasing trends in flow-normalized nutrient concentrations and loads were observed during the period at most monitoring stations for total nitrogen, nitrite plus nitrate, and total phosphorus. Average flow-normalized loads for water years 1979–2015 decreased in the Blackstone River by up to 46 percent in total nitrogen, 17 percent in nitrite plus nitrate, and 69 percent in total phosphorus. The other rivers also had decreasing flow-normalized trends in nutrient concentrations and loads, except for the Pawtuxet River, which had an increasing trend in nitrite plus nitrate. Increasing trends in flow-normalized chloride concentrations and loads were observed during the study period at all of the rivers, with increases of more than 200 percent in the Blackstone River.Small increasing trends in annual mean daily streamflow were observed in 3 of the 4 rivers, with increases of 1.2 to 11 percent; however, the trends were not significant. All 4 rivers had decreases in streamflow for the annual 7-day minimums, but only 3 of the 4 rivers had decreases that were significant (34 to 54 percent). The Branch River had decreasing annual mean daily streamflow (7.5 percent) and the largest decrease in the annual 7-day minimum streamflow. The Blackstone and Pawtuxet Rivers had the largest increases in annual maximum daily flows but had decreases in the annual 7-day minimum flows.

Declining groundwater level caused by irrigation to row crops in the Lower Mississippi River Basin, Current Situation and Trends

NASA Astrophysics Data System (ADS)

Feng, G.; Gao, F.; Ouyang, Y.

2017-12-01

The Mississippi River is North America's largest river and the second largest watershed in the world. It flows over 3,700 km through America's heartland to the Gulf of Mexico. Over 3 million hectares in the Lower Mississippi River Basin represent irrigated cropland and 90 percent of those lands currently rely on the groundwater supply. The primary crops grown in this region are soybean, corn, cotton, and rice. Increased water withdrawals for irrigating those crops and stagnant recharging jeopardize the long-term availability of the aquifer and place irrigation agriculture in the region on an unsustainable path. The objectives of this study were to: 1) analyze the current groundwater level in the Lower Mississippi River Basin based on the water table depth observed by Yazoo Mississippi Delta Joint Water Management District from 2000 and 2016; 2) determine trends of change in groundwater level under conventional and groundwater saving irrigation management practices (ET or soil moisture based full irrigation scheduling using all groundwater or different percentages of ground and surface water). The coupled SWAT and MODFLOW model was applied to investigate the trends. Observed results showed that the groundwater level has declined from 33 to 26 m at an annual decrease rate of 0.4 m in the past 17 years. Simulated results revealed that the groundwater storage was decreased by 26 cm/month due to irrigation in crop season. It is promising that the groundwater storage was increased by 23 cm/month, sometimes even 60 cm/month in crop off-growing season because of recharge from rainfall. Our results suggest that alternative ET or soil moisture based groundwater saving irrigation scheduling with conjunctive use of surface water is a sustainable practice for irrigated agriculture in in the Lower Mississippi River Basin.

Crew Earth Observations (CEO) taken during Expedition 9 over Brazil

NASA Image and Video Library

2004-07-20

ISS009-E-15488 (7 July 2004) --- Solimoes-Negro River confluence at Manaus, Amazonia is featured in this image photographed by an Expedition 9 crewmember on the International Space Station (ISS). The largest river on the planet, the Amazon, forms from the confluence of the Solimoes (the upper Amazon River) and the Negro at the Brazilian city of Manaus in central Amazonas. At the river conjunction, the muddy, tan colored waters of the Solimoes meet the “black” water of the Negro River. The unique mixing zone where the waters meet extends downstream through the rainforest for hundreds of kilometers, and is a famous attraction for tourists all over the world. It is the vast quantity of sediment eroded from the Andes Mountains that gives the Solimoes its tan color. By comparison, water in the Negro derives from the low jungles where reduced physical erosion of rock precludes mud entering the river. In place of sediment, organic matter from the forest floor stains the river the color of black tea.

Influence of multiple dam passage on survival of juvenile Chinook salmon in the Columbia River estuary and coastal ocean

PubMed Central

Rechisky, Erin L.; Welch, David W.; Porter, Aswea D.; Jacobs-Scott, Melinda C.; Winchell, Paul M.

2013-01-01

Multiple dam passage during seaward migration is thought to reduce the subsequent survival of Snake River Chinook salmon. This hypothesis developed because juvenile Chinook salmon from the Snake River, the Columbia River’s largest tributary, migrate >700 km through eight hydropower dams and have lower adult return rates than downstream populations that migrate through only 3 or 4 dams. Using a large-scale telemetry array, we tested whether survival of hatchery-reared juvenile Snake River spring Chinook salmon is reduced in the estuary and coastal ocean relative to a downstream, hatchery-reared population from the Yakima River. During the initial 750-km, 1-mo-long migration through the estuary and coastal ocean, we found no evidence of differential survival; therefore, poorer adult returns of Snake River Chinook may develop far from the Columbia River. Thus, hydrosystem mitigation efforts may be ineffective if differential mortality rates develop in the North Pacific Ocean for reasons unrelated to dam passage. PMID:23576733

Hydrological applications of Landsat imagery used in the study of the 1973 Indus River flood, Pakistan

USGS Publications Warehouse

Deutsch, Morris; Ruggles, F.H.

1978-01-01

During August and September 1973, the Indus River Valley of Pakistan experienced one of the largest floods on record, resulting in damages to homes, businesses, public works, and crops amounting to millions of rupees. Tremendous areas of lowlands were inundated along the Indus River and major tributaries. Landsat data made it possible to easily measure the extent of flooding, totaling about 20,000 km2 within an area of about 400,000 km2 south from the Punjab to the Arabian Sea.The Indus River data were used to continue experimentation in the development of rapid, accurate, and inexpensive optical techniques of flood mapping by satellite begun in 1973 for the Mississipi River floods. The research work on the Indus River not resulted in the development of more effective procedures for optical processing of flood data and synoptically depicting flooding, but also provided potentially valuable ancillary information concerning the hydrology of much of the Indus River Basin.

Feedbacks Between Bioclogging and Infiltration in Losing River Systems

NASA Astrophysics Data System (ADS)

Newcomer, M. E.; Hubbard, S. S.; Fleckenstein, J. H.; Schmidt, C.; Maier, U.; Thullner, M.; Ulrich, C.; Rubin, Y.

2014-12-01

Reduction in riverbed permeability due to biomass growth is a well-recognized yet poorly understood process associated with losing connected and disconnected rivers. Although several studies have focused on riverbed bioclogging processes at the pore-scale, few studies have quantified bioclogging feedback cycles at the scale relevant for water resources management, or at the meander-scale. At this scale, often competing hydrological-biological processes influence biomass dynamics and infiltration. Disconnection begins when declines in the water table form an unsaturated zone beneath the river maximizing seepage. Simultaneously, bioclogging reduces the point-scale infiltration flux and can either limit the nutrient flux and reduce bioclogging, or preferentially focus infiltration elsewhere and enhance bioclogging. These feedbacks are highly dependent on geomorphology and seasonal patterns of discharge and water temperature. To assess the mutual influences of disconnection, biomass growth, and temperature changes on infiltration in a geomorphologically complex river system, we built a 3D numerical model, conditioned on field data, using the reactive-transport simulator MIN3P. Results show that in disconnected regions of the river, biomass growth reduced vertical seepage downward and extended the unsaturated zone length; however these changes were contingent upon disconnection. Mid-way through the seasonal cycle, biomass declined in these same regions due to limited nutrient flux. Seepage and biomass continued to oscillate with a lag correlation of 1 month. Connected regions, however, showed the largest infiltration rates, nutrient fluxes, and concentrations of biomass. Despite the reduction in conductivity from biomass, flow remains high in connected regions because the feedback between bioclogging and infiltration is not as pronounced due to the sharpening hydraulic gradient. Bioclogging ultimately shapes the pattern of flow, however geomorphology dominates the strength of connection. Recognition of the feedbacks between geomorphological patterns and heterogeneous biomass on meander scale hydrological processes can lead to better estimates of local water volumes and capacities, especially when these systems are used as municipal and public water supply sources.

Organic Carbon and Trace Element Cycling in a River-Dominated Tidal Coastal Wetland System (Tampa Bay, FL, USA)

NASA Astrophysics Data System (ADS)

Moyer, R. P.; Smoak, J. M.; Engelhart, S. E.; Powell, C. E.; Chappel, A. R.; Gerlach, M. J.; Kemp, A.; Breithaupt, J. L.

2016-02-01

Tampa Bay is the largest open water, river-fed estuary in Florida (USA), and is characterized by the presence of both mangrove and salt marsh ecosystems. Both coastal wetland systems, and small rivers such as the ones draining into Tampa Bay have historically been underestimated in terms of their role in the global carbon and elemental cycles. Climate change and sea-level rise (SLR) are major threats in Tampa Bay and stand to disrupt hydrologic cycles, compromising sediment accumulation and the rate of organic carbon (OC) burial. This study evaluates organic carbon content, sediment accumulation, and carbon burial rates in salt marsh and mangrove ecosystems, along with measurements of fluxes of dissolved OC (DOC) and trace elements in the water column of the Little Manatee River (LMR) in Tampa Bay. The characterization of OC and trace elements in tidal rivers and estuaries is critical for quantitatively constraining these systems in local-to-regional scale biogeochemical budgets, and provide insight into biogeochemical processes occurring with the estuary and adjacent tidal wetlands. Material fluxes of DOC and trace elements were tied to discharge irrespective of season, and the estuarine habitats removed 15-65% of DOC prior to export to Tampa Bay and the Gulf of Mexico. Thus, material is available for cycling and burial within marsh and mangrove peats, however, LMR mangrove peats have higher OC content and burial rates than adjacent salt marsh peats. Sedimentary accretion rates in LMR marshes are not currently keeping pace with SLR, thus furthering the rapid marsh-to-mangrove conversions that have been seen in Tampa Bay over the past half-century. Additionally, wetlands in Tampa Bay tend to have a lower rate of carbon burial than other Florida tidal wetlands, demonstrating their high sensitivity to climate change and SLR.

Developing hydrological model for water quality in Iraq marshes zone using Landsat-TM

NASA Astrophysics Data System (ADS)

Marghany, Maged; Hasab, Hashim Ali; Mansor, Shattri; Shariff, Abdul Rashid Bin Mohamed

2016-06-01

The Mesopotamia marshlands constitute the largest wetland ecosystem in the Middle East and Western Eurasia. These wetlands are located at the confluence of the Tigris and Euphrates Rivers in southern Iraq. However, there are series reductions in the wetland zones because of neighbor countries, i.e. Turkey, Syria built dams upstream of Tigris and Euphrates Rivers. In addition, the first Gulf war of the 1980s had damaged majority of the marches resources. In fact,the marshes had been reduced in size to less than 7% since 1973 and had deteriorated in water quality parameters. The study integrates Hydrological Model of RMA-2 with Geographic Information System, and remote sensing techniques to map the water quality in the marshlands south of Iraq. This study shows that RMA-2 shows the two dimensional water flow pattern and water quality quantities in the marshlands. It can be said that the integration between Hydrological Model of RMA-2, Geographic Information System, and remote sensing techniques can be used to monitor water quality in the marshlands south of Iraq.

Catchment-wide survival of wild- and hatchery-reared Atlantic salmon smolts in a changing system

USGS Publications Warehouse

Stich, Daniel S.; Bailey, Michael M.; Holbrook, Christopher M.; Kinnison, Michael T.; Zydlewski, Joseph D.

2015-01-01

We developed a hierarchical multistate model to estimate survival of Atlantic salmon (Salmo salar) smolts in the Penobscot River, USA, over a decade during which two mainstem dams were removed from the catchment. We investigated effects of (i) environmental factors, (ii) rearing history, and (iii) management actions, including dam removal, turbine shutdown, and installation of new powerhouses. Mean ± SD smolt survival per kilometre was higher through free-flowing reaches of the catchment (0.995 ± 0.004·km−1) than through reaches containing dams that remain in the system (0.970 ± 0.019·km−1). We observed maximum survival between 12 and 17 °C and at intermediate discharges (1200 m3·s−1). Smolt survival increased concurrent with dam removal and decreased following increases in hydropower generation. The greatest increase in smolt survival followed seasonal turbine shutdowns at a dam located on the largest tributary to the Penobscot River, while other shutdowns had little influence. Our model provides a useful tool for assessing changes to survival of migratory species and will be useful for informing stocking plans to maximize numbers of smolts leaving coastal systems.

Sedimentary and hydrological studies of the Holocene palaeofloods in the Shanxi-Shaanxi Gorge of the middle Yellow River, China

NASA Astrophysics Data System (ADS)

Li, Xiaogang; Huang, Chun Chang; Pang, Jiangli; Zha, Xiaochun; Ma, Yugai

2015-01-01

Holocene slackwater deposits along the river channels were used to study the magnitude and frequency of the palaeofloods that occurred prior to gauged and historical data sets all over the world. Palaeohydrological investigations along the Shanxi-Shaanxi Gorge of the middle Yellow River, China, identified palaeoflood slackwater deposits (SWDs) at several sites along the cliffs bordering the river channel. The SWDs are intercalated within Holocene eolian loess-soil profiles and clastic slope deposits. The palaeoflood SWDs were differentiated from eolian loess and soil by the sedimentary criteria and analytical results including magnetic susceptibility and particle-size distribution, similar to the flood SWDs in 2012, which indicated that these well-sorted palaeoflood SWD beds were deposited from the suspended sediment load in floodwaters. They have recorded the extraordinary palaeoflood events which occurred between 3200 and 3000 a BP as dated by the optically stimulated luminescence method in combination with pedostratigraphic correlations with the previously studied Holocene pedo-stratigraphy in the Yellow River drainage basin. Manning slope-area calculations estimate the peak discharged for these palaeoflood events to range from 43,290 to 49,830 m3/s. The drainage area of the study site is 489,900 km2. It is 2.0-2.5 times the largest gauged flood (21,000 m3/s) that has ever occurred since 1934. These events also occurred on Yellow River tributaries, including the Weihe, Jinghe and Qishuihe Rivers. These flood events are therefore considered to be a regional expression of known climatic events in the northern hemisphere and demonstrate Holocene climatic instability. This study provides important data in understanding the interactions between regional hydro-climatic systems and global change in semiarid and subhumid regions.

Hydroecological monitoring in the headwaters of the Volga River

NASA Astrophysics Data System (ADS)

Kuzovlev, Viacheslav V.; Zhenikov, Yuri N.; Zhenikov, Kyrill Y.; Shaporenko, Sergey I.; Haun, Stefan; Füreder, Leopold; Schletterer, Martin

2016-04-01

Europe's largest river, the Volga (3551 km), has experienced multiple stressors from human activities (i.e. the Volga Basin comprises about 40 % of the Russian population, 45 % of the country's industry and more than 50 % of its agriculture). During the research expedition "Upper Volga 2005" an assessment of hydrological, limnochemical and biological parameters was carried out by scientists from the Russian Federation and from Austria. The extensive sampling in 2005 showed that the free-flowing section of the Volga River, located upstream of Tver, represents conditions which are either reference or least disturbed - thus it can be considered as a refugial system for freshwater biota of the European lowlands. Subsequently three stretches in the headwaters of the Volga River (Rzhev, Staritsa, Tver) were selected for the monitoring programme "REFCOND_VOLGA", which is in operation since 2006. These locations correspond also with the sampling sites of ROSHYDROMET, i.e. at Tver physic-chemical samples are taken monthly and at Rzhev samples are taken in the main hydrological periods. The laboratory ship "ROSHYDROMET 11" conducted monthly cruises between Tver and Kalyazin (Ivankovskoye and Uglichskoye reservoirs on Volga) in the headwaters during the navigation period (May - October). This also includes measurements with ADCP, which further allow the analyses of the spatial distribution of the suspended solids within cross sections. In addition sediment fluxes were derived by using the acoustic backscatter signal strength from the acoustic current Doppler profiler (ADCP). We exemplify at the monitoring sites the spatial distribution of different sediments, i.e. choriotope types, according the longitudinal profile of the river. We show that it is highly influenced by morphodynamics in the different river sections and this corresponds with the zoobenthos fauna accordingly. This interdisciplinary approach, including sediment conditions, limnochemistry, hydrology and hydrobiology, leads to a hydro-ecological reference for European lowland rivers.

The impact of snowpack decline on high elevation surface-water flow in the Willamette River: a stable isotope perspective

NASA Astrophysics Data System (ADS)

Brooks, J. R.; Johnson, H.; Cline, S. P.; Rugh, W.

2015-12-01

Much of the water that people in Western Oregon rely on comes from the snowpack in the Cascade Range, and this snowpack is expected to decrease in coming years with climate change. In fact, the past five years have shown dramatic variation in snowpack from a high of 174% of normal in 2010-11 to a low of 11% for 2014-15, one of the lowest on record. During this timeframe, we have monitored the stable isotopes of water within the Willamette River twice monthly, and mapped the spatial variation of water isotopes across the basin. Within the Willamette Basin, stable isotopes of water in precipitation vary strongly with elevation and provide a marker for determining the mean elevation from which water in the Willamette River is derived. In the winter when snow accumulates in the mountains, low elevation precipitation (primarily rain) contributes the largest proportion of water to the Willamette River. During summer when rainfall is scarce and demand for water is the greatest, water in the Willamette River is mainly derived from high elevation snowmelt. Our data indicate that the proportion of water from high elevation decreased with decreasing snowpack. We combine this information with the river flow data to estimate the volume reduction related to snow pack reduction during the dry summer. Observed reductions in the contribution of high elevation water to the Willamette River after just two years of diminished snowpack indicate that the hydrologic system responds relatively rapidly to changing snowpack volume. Reconciling the demands between human use and biological instream requirements during summer will be challenging under climatic conditions in which winter snowpack is reduced compared to historical amounts.

Relationship between urbanisation and pollutant emissions in transboundary river basins under the strategy of the Belt and Road Initiative.

PubMed

Yu, Sen; Lu, Hongwei

2018-07-01

Urbanisation has increased the discharge of pollutants, altered water flow regimes, and modified the morphology of transboundary river basins. All these actions have resulted in multiple pressures on aquatic ecosystems of transboundary river basins, undermining the healthy development of their aquatic ecosystems as well as impairing the sustainable economic and social development associated therewith. Quantifying the relationship between socio-economic factors, and water environment systems, and understanding the multiple pressures in their combined impact on environmental fairness of transboundary river basins is challenging, and it is crucial to the strategic planning of the Belt and Road strategy. Here, the Songhua River basin, which is the largest branch of the China-Russia boundary river is taken as the study area. The Environmental Kuznets Curve (EKC) model, which is coupled with the integrated model (pollutant emissions intensity, pollutant discharge efficiency, and pollutant emissions per capita), are used to reveal the spatio-temporal variations in regional pollutant emissions in the SRB. The results show that the features of the EKC are present in the pollutant emissions during economic development of the SRB. It also demonstrates that the turning point value of the EKC appeared when the GDP per capita is around ¥40,000 (CNY) in the SRB, which means that the pollutant emissions show an increasing trend, when the GDP per capita is less than ¥40,000. Our findings could contribute to a better understanding of the coupling relationship between pollutant emissions in transboundary river basins and urbanisation process in water stress to help address water allocation problems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Patterns of Bacterial and Archaeal Gene Expression through the Lower Amazon River

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

Satinsky, Brandon M.; Smith, Christa B.; Sharma, Shalabh

Analysis of metatranscriptomic and metagenomic datasets from the lower reaches of the Amazon River between Obidos and the river mouth revealed microbial transcript and gene pools dominated by Actinobacteria, Thaumarchaeota, Bacteroidetes, Acidobacteria, Betaproteobacteria, and Planctomycetes. Three mainstem stations spanning a 625 km reach had similar gene expression patterns (transcripts gene copy-1) across a diverse suite of element cycling genes, but two tributary-influenced stations at the mouth of the Tapajos River and near the Tocantins River at Belem had distinct transcriptome composition and expression ratios, particularly for genes encoding light-related energy capture (higher) and iron acquisition and ammonia oxidation (lower). Environmentalmore » parameters that were useful predictors of gene expression ratios included concentrations of lignin phenols, suspended sediments, nitrate, phosphate, and particulate organic carbon and nitrogen. Similar to the gene expression data, these chemical properties reflected highly homogeneous mainstem stations punctuated by distinct tributary- influenced stations at Tapajos and Belem. Although heterotrophic processes were expected to dominate in the lower Amazon, transcripts from photosynthetic bacteria were abundant in tributary-influenced regions, and transcripts from Thaumarcheota taxa genetically capable of chemosynthetic ammonia oxidation accounted for up to 21% of the transcriptome at others. Based on regressions of transcript numbers against gene numbers, expression ratios of Thaumarchaeota populations were largely unchanged within the mainstem, suggesting a relatively minor role for gene regulation. These quantitative gene and transcript inventories detail a diverse array of energy acquisition strategies and metabolic capabilities for bacteria and archaea populations of the world’s largest river system.« less

Assessment of macrophyte, heavy metal, and nutrient concentrations in the water of the Nairobi River, Kenya.

PubMed

Njuguna, Samwel Maina; Yan, Xue; Gituru, Robert Wahiti; Wang, Qingfeng; Wang, Jun

2017-08-16

Nairobi River tributaries are the main source of the Athi River. The Athi River basin is the fourth largest and important drainage system in Kenya covering 650 km and with a drainage area of 70,000 km 2 . Its water is used downstream by about four million people not only for irrigation but also for domestic purposes. However, its industrial, raw sewer, and agricultural pollution is alarming. In order to understand distribution and concentration of heavy metals and nutrients in the water of Nairobi River, 28 water samples were collected in the rainy season (October) of 2015 and dry season (June) of 2016. Cd, Cu, Cr, Zn, As, Pb, Fe, Ni, Mn, NO 3 - , and TP were analyzed. Only Cr, Pb, Fe, and Mn had concentrations exceeding the WHO permissible limit for drinking water. Out of the 28 sites examined in the study, one site had Pb exceeding the WHO recommended level. Similarly, three sites exceeded the same level for Cr. Only three sites were within the WHO permissible limits for drinking water for Mn while just four sites were within USEPA limit for Fe. Industrial effluent, domestic sewerage, agricultural activities, and solid waste were the main sources of pollution. Significant spatial variation of both heavy metals and nutrients concentration was observed and emanated from point source pollution. Eleven out of 31 macrophytes species that were identified along the river and its tributaries are effective heavy metal and nutrient bioaccumulators and may be used in phytoremediation.

Water quality, sediment, and soil characteristics near Fargo-Moorhead urban areas as affected by major flooding of the Red River of the north

Treesearch

A.C. Guy; T.M. DeSutter; F.X.M. Casey; R. Kolka; H. Hakk

2012-01-01

Spring flooding of the Red River of the North (RR) is common, but little information exits on how these flood events affect water and overbank sediment quality within an urban area. With the threat of the spring 2009 flood in the RR predicted to be the largest in recorded history and the concerns about the flooding of farmsteads, outbuildings, garages, and basements,...

A 2,000-mile partnership with the USGS, Kayaks down the Yukon

USGS Publications Warehouse

Schuster, P.; Reddy, M.

2003-01-01

Early in 2001, Bill Barber and Jay Klinck, avid kayakers and scientists, began planning a northern expedition that would take them across more than 2,000 miles of mostly untamed wilderness along the Yukon River. At the same time, USGS scientists were making plans to study the last, unregulated great river in North America, spanning one of the largest and most diverse ecosystems in the world. Soon, the paths of kayakers and scientists would cross.

Early onset of a microcystin-producing cyanobacterial bloom in an agriculturally-influenced Great Lakes tributary

NASA Astrophysics Data System (ADS)

McKay, Robert Michael L.; Tuttle, Taylor; Reitz, Laura A.; Bullerjahn, George S.; Cody, William R.; McDowell, Adam J.; Davis, Timothy W.

2018-05-01

In late May 2016, a cyanobacterial harmful algal bloom (cHAB) was detected in the Maumee River, the largest tributary to Lake Erie, the southernmost lake of the Laurentian Great Lakes system. Testing on 31 May identified Planktothrix agardhii as the dominant cyanobacterium with cell abundance exceeding 1.7×10 9 cells/L and total microcystins (MC) reaching 19 μg/L MC-LR equivalents, a level over 10-fold higher than the 2015 revised U.S. Environmental Protection Agency (EPA) national health advisory levels for drinking water exposure to adults. Low river discharge coincident with negligible precipitation through the latter half of May coincided with an 80% decline in river turbidity that likely favored bloom formation by a low-light adapted P. agardhii population. Also contributing to the cHAB were high initial nutrient loads and an increase of the river temperature from 13°C to 26°C over this same period. The bloom persisted through 5 June with microcystins exceeding 22 μg/L MC-LR equivalents at the bloom peak. By 6 June, the river had returned to its muddy character following a rain event and sampling on 7 June detected only low levels of toxin (<0.6 μg/L) at public water systems located near the bloom origin. The elevated toxin production associated with this early onset bloom was without precedent for the Maumee River and an unique attribute of the cHAB was the high proportion of potentially-toxic genotypes. Whereas Planktothrix spp. is common in lotic environments, and has been previously detected in the Maumee, blooms are not commonly reported. This early onset, microcystin-producing cHAB provided a rare opportunity to glean insights into environmental factors that promote bloom development and dominance by Planktothrix in lotic environments.

Modelling nitrogen transformation and removal in mara river basin wetlands upstream of lake Victoria

NASA Astrophysics Data System (ADS)

Mayo, Aloyce W.; Muraza, Marwa; Norbert, Joel

2018-06-01

Lake Victoria, the largest lake in Africa, is a resource of social-economic potential in East Africa. This lake receives water from numerous tributaries including Mara River, which contributes about 4.8% of the total Lake water inflow. Unfortunately, Mara River basin faces environmental problems because of intensive settlement, agriculture, overgrazing in the basin and mining activities, which has lead to water pollution in the river, soil erosion and degradation, decreased soil fertility, loss of vegetation cover, decreased water infiltration capacity and increased sedimentation. One of the pollutants carried by the river includes nitrogen, which has contributed to ecological degradation of the Lake Victoria. Therefore this research work was intended to determine the effectiveness of Mara River wetland for removal of nitrogen and to establish nitrogen removal mechanisms in the wetland. To predict nitrogen removal in the wetland, the dynamics of nitrogen transformation was studied using a conceptual numerical model that takes into account of various processes in the system using STELLA II version 9.0®2006 software. Samples of model input from water, plants and sediments were taken for 45 days and were analyzed for pH, temperature, and DO in situ and chemical parameters such as NH3-N, Org-N, NO2-N, and NO3-N were analyzed in the laboratory in accordance with Standard methods. For plants, the density, dominance, biomass productivity and TN were determined and for sediments TN was analyzed. Inflow into the wetland was determined using stage-discharge relationship and was found to be 734,400 m3/day and the average wetland volume was 1,113,500 m3. Data collected by this study were used for model calibration of nitrogen transformation in this wetland while data from another wetland were used for model validation. It was found that about 37.8% of total nitrogen was removed by the wetland system largely through sedimentation (26.6%), plant uptake (6.6%) and denitrification (4.6%).

Ecotoxicologic impacts of agricultural drain water in the Salinas River, California, USA.

PubMed

Anderson, Brian S; Hunt, John W; Phillips, Bryn M; Nicely, Patricia A; Gilbert, Kristine D; de Vlaming, Victor; Connor, Valerie; Richard, Nancy; Tjeerdema, Ronald S

2003-10-01

The Salinas River is the largest of the three rivers that drain into the Monterey Bay National Marine Sanctuary in central California (USA). Large areas of this watershed are cultivated year-round in row crops, and previous laboratory studies have demonstrated that acute toxicity of agricultural drain water to Ceriodaphnia dubia is caused by the organophosphate (OP) pesticides chlorpyrifos and diazinon. We investigated chemical contamination and toxicity in waters and sediments in the river downstream of an agricultural drain water input. Ecological impacts of drain water were investigated by using bioassessments of macroinvertebrate community structure. Toxicity identification evaluations were used to characterize chemicals responsible for toxicity. Salinas River water downstream of the agricultural drain was acutely toxic to the cladoceran Ceriodaphnia dubia, and toxicity to C. dubia was highly correlated with combined toxic units (TUs) of chlorpyrifos and diazinon. Laboratory tests were used to demonstrate that sediments in this system were acutely toxic to the amphipod Hyalella azteca, a resident invertebrate. Toxicity identification evaluations (TIEs) conducted on sediment pore water suggested that toxicity to amphipods was due in part to OP pesticides; concentrations of chlorpyrifos in pore water sometimes exceeded the 10-d mean lethal concentration (LC50) for H. azteca. Potentiation of toxicity with addition of the metabolic inhibitor piperonyl butoxide suggested that sediment toxicity also was due to other non-metabolically activated compounds. Macroinvertebrate community structure was highly impacted downstream of the agricultural drain input, and a number of macroinvertebrate community metrics were negatively correlated with combined TUs of chlorpyrifos and diazinon, as well as turbidity associated with the drain water. Some macroinvertebrate metrics were also correlated with bank vegetation cover. This study suggests that pesticide pollution is the likely cause of ecological damage in the Salinas River, and this factor may interact with other stressors associated with agricultural drain water to impact the macroinvertebrate community in the system.

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.

Montreal, Quebec, Canada as seen from STS-60

NASA Technical Reports Server (NTRS)

1994-01-01

The city of Montreal is located on the island of Montreal at the confluence of the St. Lawrence and Ottawa Rivers. Despite its distance from the sea (1,000 miles) Montreal is a large inland port. It is also Canada's largest city and the second largest French speaking city in the world. This particular snow covered scene highlights the major highways and street patterns throughout the metropolitan Montreal area. The runways of the two large international airports of Mirabel (located 25 miles northwest of downtown Montreal) and Dorval (located approximately 8 miles west of the downtown area) are clearly visible on this photograph. Even the outline of Mount Royal Park, near downtown central business district, can be seen. Patches of open, ice-free water (very dark areas) are detectable as the St. Lawrence River (Seaway) makes its way along the south and southeastern side of Montreal.

Montreal, Quebec, Canada as seen from STS-60

NASA Image and Video Library

1994-02-09

STS060-94-072 (3-11 Feb 1994) --- The city of Montreal is located on the island of Montreal at the confluence of the St. Lawrence and Ottawa Rivers. Despite its distance from the sea (1,000 miles) Montreal is a large inland port. It is also Canada's largest city and the second largest French speaking city in the world. This particular snow covered scene highlights the major highways and street patterns throughout the metropolitan Montreal area. The runways of the two large international airports of Mirabel (located 25 miles northwest of downtown Montreal) and Dorval (located approximately 8 miles west of the downtown area) are clearly visible on this photograph. Even the outline of Mount Royal Park, an imposing hilly feature near the downtown central business district, can be seen. Patches of open, ice-free (very dark areas) are detectable as the St. Lawrence River (Seaway) makes its way along the south and southeastern side of Montreal.

Towards a climate impact assessment of the Tarim River, NW China: integrated hydrological modelling using SWIM

NASA Astrophysics Data System (ADS)

Wortmann, Michel

2014-05-01

The Tarim River is the principle water source of the Xinjiang Uyghur Autonomous Region, NW China and the country's largest endorheic river, terminating in the Taklamakan desert. The vast majority of discharge is generated in the glaciated mountain ranges to the north (Tian Shan), south (Kunlun Shan/Tibetan Plateau) and west (Pamir Mountains) of the Taklamakan desert. The main water user is the intensive irrigation agriculture for mostly cotton and fruit production in linear river oases of the middle and lower reaches as well as a population of 10 Mil. people. Over the past 40 years, an increase in river discharge was reported, assumed to be caused by enhanced glacier melt due to a warming climate. Rapid population growth and economic development have led to a significant expansion of area under irrigation, resulting in water shortages for downstream users and the floodplain vegetation. Water resource planning and management of the Tarim require integrated assessment tools to examine changes under future climate change, land use and irrigation scenarios. The development of such tools, however, is challenged by sparse climate and discharge data as well as available data on water abstractions and diversions. The semi-distributed, process-based hydrological model SWIM (Soil and Water Integrated Model) was implemented for the headwater and middle reaches that generate over 90% of discharge, including the Aksu, Hotan and Yarkant rivers. It includes the representation of snow and glacier melt as well as irrigation abstractions. Once calibrated and validated to river discharge, the model is used to analyse future climate scenarios provided by one physically-based and one statistical regional climate model (RCM). Preliminary results of the model calibration and validation indicate that SWIM is able simulate river discharge adequately, despite poor data conditions. Snow and glacier melt account for the largest share in river discharge. The modelling results will devise sustainable management options for given climate change scenarios with the aim to balance water availability and water use for the basin as a whole and specifically for the riparian ecology.

Assessing cadmium and vanadium accumulation using diffusive gradient in thin-films (DGT) and phytoplankton in the Churchill River estuary, Manitoba.

PubMed

Mangal, V; Zhu, Y; Shi, Y X; Guéguen, C

2016-11-01

Diffusive gradient in thin films (DGT) and phytoplankton communities were evaluated for the measurement of Cd and V at environmentally relevant concentrations in laboratory settings and in the Churchill River estuary (Manitoba, Canada) during an annual spring melt. Despite rapid changes in hydrology and water quality, DGT samplers and intracellular Cd and V concentrations were positively correlated (0.79 < r(2) < 0.99), suggesting comparable accumulation trends between both DGT-labile and intracellular monitoring techniques. The largest accumulated concentrations of both Cd and V by DGT and phytoplankton accumulation methods were found later into the river discharge period. In controlled settings, accumulated Cd and V concentrations by the diatom Attheya septentrionalis displayed a strong correlation with metals accumulated by DGTs (r(2) > 0.99). Principal component analysis (PCA) reinforced similarities between both metal monitoring techniques and assessed how changing environmental variables during the river discharge period influenced each monitoring technique. Cd accumulation was influenced by DOC concentrations and protein-like DOM whereas ionic strength (i.e. conductivity) and humic-like DOM influenced V accumulation. The present findings suggest that (1) DGT is a versatile tool for monitoring bioaccumulation of Cd and V in highly dynamic environmental systems and (2) DOC concentration, DOM composition, conductivity, pH, and river discharge influence the bioavailability of Cd and V in estuarine and riverine waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Health risk assessment of heavy metals in fish and accumulation patterns in food web in the upper Yangtze River, China.

PubMed

Yi, Yujun; Tang, Caihong; Yi, Tieci; Yang, Zhifeng; Zhang, Shanghong

2017-11-01

This study aims to concern the distribution of As, Cr, Cd, Hg, Cu, Zn, Pb and Fe in surface sediment, zoobenthos and fishes, and quantify the accumulative ecological risk and human health risk of metals in river ecological system based on the field investigation in the upper Yangtze River. The results revealed high ecological risk of As, Cd, Cu, Hg, Zn and Pb in sediment. As and Cd in fish presented potential human health risk of metals by assessing integrated target hazard quotient results based on average and maximum concentrations, respectively. No detrimental health effects of heavy metals on humans were found by daily fish consumption. While, the total target hazard quotient (1.659) exceeding 1, it meant that the exposed population might experience noncarcinogenic health risks from the accumulative effect of metals. Ecological network analysis model was established to identify the transfer routes and quantify accumulative effects of metals on river ecosystem. Control analysis between compartments showed large predator fish firstly depended on the omnivorous fish. Accumulative ecological risk of metals indicated that zoobenthos had the largest metal propagation risk and compartments located at higher trophic levels were not easier affected by the external environment pollution. A potential accumulative ecological risk of heavy metal in the food web was quantified, and the noncarcinogenic health risk of fish consumption was revealed for the upper reach of the Yangtze River. Copyright © 2017 Elsevier Inc. All rights reserved.

How to allocate water resources under climate change in the arid endorheic river basin, Northwest China

NASA Astrophysics Data System (ADS)

Zhang, A.; Feng, D.; Tian, Y.; Zheng, Y.

2017-12-01

Water resource is of fundamental importance to the society and ecosystem in arid endorheic river basins, and water-use conflicts between upstream and downstream are usually significant. Heihe river basin (HRB) is the second largest endorheic river basin in china, which is featured with dry climate, intensively irrigated farmlands in oases and significant surface water-groundwater interaction. The irrigation districts in the middle HRB consume a large portion of the river flow, and the low HRB, mainly Gobi Desert, has an extremely vulnerable ecological environment. The water resources management has significantly altered the hydrological processes in HRB, and is now facing multiple challenges, including decline of groundwater table in the middle HRB, insufficient environmental flow for the lower HRB. Furthermore, future climate change adds substantial uncertainty to the water system. Thus, it is imperative to have a sustainable water resources management in HRB in order to tackle the existing challenges and future uncertainty. Climate projection form a dynamical downscaled climate change scenario shows precipitation will increase at a rate of approximately 3 millimeter per ten years and temperature will increase at a rate of approximately 0.2 centigrade degree per ten years in the following 50 years in the HRB. Based on an integrated ecohydrological model, we evaluated how the climate change and agricultural development would collaboratively impact the water resources and ecological health in the middle and lower HRB, and investigated how the water management should cope with the complex impact.

Sampling little fish in big rivers: Larval fish detection probabilities in two Lake Erie tributaries and implications for sampling effort and abundance indices

USGS Publications Warehouse

Pritt, Jeremy J.; DuFour, Mark R.; Mayer, Christine M.; Roseman, Edward F.; DeBruyne, Robin L.

2014-01-01

Larval fish are frequently sampled in coastal tributaries to determine factors affecting recruitment, evaluate spawning success, and estimate production from spawning habitats. Imperfect detection of larvae is common, because larval fish are small and unevenly distributed in space and time, and coastal tributaries are often large and heterogeneous. We estimated detection probabilities of larval fish from several taxa in the Maumee and Detroit rivers, the two largest tributaries of Lake Erie. We then demonstrated how accounting for imperfect detection influenced (1) the probability of observing taxa as present relative to sampling effort and (2) abundance indices for larval fish of two Detroit River species. We found that detection probabilities ranged from 0.09 to 0.91 but were always less than 1.0, indicating that imperfect detection is common among taxa and between systems. In general, taxa with high fecundities, small larval length at hatching, and no nesting behaviors had the highest detection probabilities. Also, detection probabilities were higher in the Maumee River than in the Detroit River. Accounting for imperfect detection produced up to fourfold increases in abundance indices for Lake Whitefish Coregonus clupeaformis and Gizzard Shad Dorosoma cepedianum. The effect of accounting for imperfect detection in abundance indices was greatest during periods of low abundance for both species. Detection information can be used to determine the appropriate level of sampling effort for larval fishes and may improve management and conservation decisions based on larval fish data.

Data mining of external and internal forcing of fluvial systems for catchment management: A case study on the Red River (Song Hong), Vietnam

NASA Astrophysics Data System (ADS)

Schmitt, Rafael; Bizzi, Simone; Castelletti, Andrea

2013-04-01

The understanding of river hydromorphological processes has been recognized in the last decades as a priority of modern catchment management, since interactions of natural and anthropogenic forces within the catchment drives fluvial geomorphic processes, which shape physical habitat, affect river infrastructures and influence freshwater ecological processes. The characterization of river hydromorphological features is commonly location and time specific and highly resource demanding. Therefore, its routine application at regional or national scales and the assessment of spatio-temporal changes as reaction to internal and external disturbances is rarely feasible at present. Information ranging from recently available high-resolution remote-sensing data (such as DEM), historic data such as land use maps or aerial photographs and monitoring networks of flow and rainfall, open up novel and promising capacity for basin-wide understanding of dominant hydromorphological drivers. Analysing the resulting multiparametric data sets in their temporal and spatial dimensions requires sophisticated data mining tools to exploit the potential of this information. We propose a novel framework that allows for the quantitative assessment of multiparametric data sets to identify classes of channel reaches characterized by similar geomorphic drivers using remote-sensing data and monitoring networks available in the catchment. This generic framework was applied to the Red River (Song Hong) basin, the second largest basin (87,800 sq.km) in Vietnam. Besides its economic importance, the river is experiencing severe river bed incisions due to recent construction of new dams in the upstream part of the catchment and sand mining in the surrounding of the capital city Hanoi. In this context, characterized by an high development rate, current efforts to increase water productivity and minimize impacts on the fluvial systems by means of focused infrastructure and management measures require a thorough understanding of the fluvial system and, in particular, basin-wide assessment of resilience to human-induced change. . The framework proposed has allowed producing high-dimensional samples of spatially distributed geomorphic drivers at catchment scale while integrating recent and historic point records for the Red River basin. This novel dataset has been then analysed using self-organizing maps (SOM) an artificial neural network model in combination with fuzzy clustering. The above framework is able to identify non-trivial correlations in driving forces and to derive a fuzzy classification at reach scale which represents continuities and discontinuities in the river systems. The use of the above framework allowed analyzing the spatial distribution of geomorphic features at catchment scale, revealing patterns of similarities and dissimilarities within the catchment and allowing a classification of river reaches characterized by similar geomorphic drivers, fluvial processes and response to external forcing. The paper proposes an innovative and promising technique to produce hydromorphological classifications at catchment scale integrating historical and recent available high resolution data. The framework aims at opening the way to a more structured organization and analyses of recently available information on river geomorphic features, so far often missing or rarely exploited. This approach poses the basis to produce efficient databases of river geomorphic features and processes related to natural and anthropogenic drivers. That is a necessity in order to enhance our understanding of the internal and external forces which drive fluvial systems, to assess the resilience and dynamic of river landscapes and to develop the more efficient river management strategies of the future.

Multiscale spatial and small-scale temporal variation in the composition of Riverine fish communities.

PubMed

Growns, Ivor; Astles, Karen; Gehrke, Peter

2006-03-01

We studied the multiscale (sites, river reaches and rivers) and short-term temporal (monthly) variability in a freshwater fish assemblage. We found that small-scale spatial variation and short-term temporal variability significantly influenced fish community structure in the Macquarie and Namoi Rivers. However, larger scale spatial differences between rivers were the largest source of variation in the data. The interaction between temporal change and spatial variation in fish community structure, whilst statistically significant, was smaller than the variation between rivers. This suggests that although the fish communities within each river changed between sampling occasions, the underlying differences between rivers were maintained. In contrast, the strongest interaction between temporal and spatial effects occurred at the smallest spatial scale, at the level of individual sites. This means whilst the composition of the fish assemblage at a given site may fluctuate, the magnitude of these changes is unlikely to affect larger scale differences between reaches within rivers or between rivers. These results suggest that sampling at any time within a single season will be sufficient to show spatial differences that occur over large spatial scales, such as comparisons between rivers or between biogeographical regions.

The influence of tides on biogeochemical dynamics at the mouth of the Amazon River

NASA Astrophysics Data System (ADS)

Ward, N. D.; Sawakuchi, H. O.; Neu, V.; de Matos Valerio, A.; Less, D.; Guedes, V.; Wood, J.; Brito, D. C.; Cunha, A. C.; Kampel, M.; Richey, J. E.

2017-12-01

A major barrier to computing the flux of constituents from the world's largest rivers to the ocean is understanding the dynamic processes that occur along tidally-influenced river reaches. Here, we examine the response of a suite of biogeochemical parameters to tide-induced flow reversals at the mouth of the Amazon River. Continuous measurements of pCO2, pCH4, dissolved O2, pH, turbidity, and fluorescent dissolved organic matter (FDOM) were made throughout tidal cycles while held stationary in the center of the river and during hourly transects for ADCP discharge measurements. Samples were collected hourly from the surface and 50% depth during stationary samplings and from the surface during ADCP transects for analysis of suspended sediment concentrations along with other parameters such as nutrient and mercury concentrations. Suspended sediment and specific components of the suspended phase, such as particulate mercury, concentrations were positively correlated to mean river velocity during both high and low water periods with a more pronounced response at 50% depth than the surface. Tidal variations also influenced the concentration of O2 and CO2 by altering the dynamic balance between photosynthesis, respiration, and gas transfer. CO2 was positively correlated and O2 and pH were negatively correlated with river velocity. The concentration of methane generally increased during low tide (i.e. when river water level was lowest) both in the mainstem and in small side channels. In side channels concentrations increased by several orders of magnitude during low tide with visible bubbling from the sediment, presumably due to a release of hydrostatic pressure. These results suggest that biogeochemical processes are highly dynamic in tidal rivers, and these dynamic variations need to be quantified to better constrain global and regional scale budgets. Understanding these rapid processes may also provide insight into the long-term response of aquatic systems to change.

Distribution and characterization of in-channel large wood in relation to geomorphic patterns on a low-gradient river

USGS Publications Warehouse

Moulin, Bertrand; Schenk, Edward R.; Hupp, Cliff R.

2011-01-01

A 177 river km georeferenced aerial survey of in-channel large wood (LW) on the lower Roanoke River, NC was conducted to determine LW dynamics and distributions on an eastern USA low-gradient large river. Results indicate a system with approximately 75% of the LW available for transport either as detached individual LW or as LW in log jams. There were approximately 55 individual LW per river km and another 59 pieces in log jams per river km. Individual LW is a product of bank erosion (73% is produced through erosion) and is isolated on the mid and upper banks at low flow. This LW does not appear to be important for either aquatic habitat or as a human risk. Log jams rest near or at water level making them a factor in bank complexity in an otherwise homogenous fine-grained channel. A segmentation test was performed using LW frequency by river km to detect breaks in longitudinal distribution and to define homogeneous reaches of LWfrequency. Homogeneous reaches were then analyzed to determine their relationship to bank height, channel width/depth, sinuosity, and gradient. Results show that log jams are a product of LW transport and occur more frequently in areas with high snag concentrations, low to intermediate bank heights, high sinuosity, high local LW recruitment rates, and narrow channel widths. The largest concentration of log jams (21.5 log jams/km) occurs in an actively eroding reach. Log jam concentrations downstream of this reach are lower due to a loss of river competency as the channel reaches sea level and the concurrent development of unvegetated mudflats separating the active channel from the floodplain forest. Substantial LW transport occurs on this low-gradient, dam-regulated large river; this study, paired with future research on transport mechanisms should provide resource managers and policymakers with options to better manage aquatic habitat while mitigating possible negative impacts to human interests.

Estimation of River Bathymetry from ATI-SAR Data

NASA Astrophysics Data System (ADS)

Almeida, T. G.; Walker, D. T.; Farquharson, G.

2013-12-01

A framework for estimation of river bathymetry from surface velocity observation data is presented using variational inverse modeling applied to the 2D depth-averaged, shallow-water equations (SWEs) including bottom friction. We start with with a cost function defined by the error between observed and estimated surface velocities, and introduce the SWEs as a constraint on the velocity field. The constrained minimization problem is converted to an unconstrained minimization through the use of Lagrange multipliers, and an adjoint SWE model is developed. The adjoint model solution is used to calculate the gradient of the cost function with respect to river bathymetry. The gradient is used in a descent algorithm to determine the bathymetry that yields a surface velocity field that is a best-fit to the observational data. In applying the algorithm, the 2D depth-averaged flow is computed assuming a known, constant discharge rate and a known, uniform bottom-friction coefficient; a correlation relating surface velocity and depth-averaged velocity is also used. Observation data was collected using a dual beam squinted along-track-interferometric, synthetic-aperture radar (ATI-SAR) system, which provides two independent components of the surface velocity, oriented roughly 30 degrees fore and aft of broadside, offering high-resolution bank-to-bank velocity vector coverage of the river. Data and bathymetry estimation results are presented for two rivers, the Snohomish River near Everett, WA and the upper Sacramento River, north of Colusa, CA. The algorithm results are compared to available measured bathymetry data, with favorable results. General trends show that the water-depth estimates are most accurate in shallow regions, and performance is sensitive to the accuracy of the specified discharge rate and bottom friction coefficient. The results also indicate that, for a given reach, the estimated water depth reaches a maximum that is smaller than the true depth; this apparent maximum depth scales with the true river depth and discharge rate, so that the deepest parts of the river show the largest bathymetry errors.

Earth observations taken by the Expedition 12 crew

NASA Image and Video Library

2005-11-15

ISS012-E-11779 (8 Dec. 2005) --- Ciudad Guayana, Venezuela is featured in this image photographed by an Expedition 12 crew member on the International Space Station. Ciudad Guayana lies on the south bank of the Orinoco River, the second largest in South America, at its confluence with the Caroní (lower left) River. Islands have developed in the Orinoco at a wide sector opposite the city. Guayana is one of the newest cities in Venezuela, having been constructed in 1961 as a new economic growth center for the interior of Venezuela, especially for major industries such as iron, steel, and aluminum. The city stretches 40 kilometers along the south bank of the Orinoco with a population of approximately 800,000 people, one of Venezuela’s largest urban populations. A low barrage (lower left) dams the Caroní as a water supply for the city. The Orinoco River carries brown muddy sediment produced by erosion of the young Andes Mountains far to the southwest. By contrast, the Caroní drains the ancient landscapes of the Guyana Highlands where erosion is so slow that the river water is clear (appearing dark blue) due to a significantly lower sediment load. As at the famous confluence of the brown Amazon and clear Negro rivers in Amazonia, a mixing zone can be seen in the middle of the view, the clear Caroní water producing a less muddy zone for tens of kilometers downstream of the confluence (this part of the Orinoco flows almost due east, left to right).

Three decadal inputs of total organic carbon from four major coastal river basins to the summer hypoxic zone of the Northern Gulf of Mexico.

PubMed

He, Songjie; Xu, Y Jun

2015-01-15

This study investigated long-term (1980-2009) yields and variability of total organic carbon (TOC) from four major coastal rivers in Louisiana entering the Northern Gulf of Mexico where a large-area summer hypoxic zone has been occurring since the middle 1980s. Two of these rivers drain agriculture-intensive (>40%) watersheds, while the other two rivers drain forest-pasture dominated (>50%) watersheds. The study found that these rivers discharged a total of 13.0×10(4)t TOC annually, fluctuating from 5.9×10(4) to 22.8×10(4)t. Seasonally, the rivers showed high TOC yield during the winter and early spring months, corresponding to the seasonal trend of river discharge. While river hydrology controlled TOC yields, land use has played an important role in fluxes, seasonal variations, and characteristics of TOC. The findings fill in a critical information gap of quantity and quality of organic carbon transport from coastal watersheds to one of the world's largest summer hypoxic zones. Copyright © 2014 Elsevier Ltd. All rights reserved.

Flood of June 8-9, 2008, Upper Iowa River, Northeast Iowa

USGS Publications Warehouse

Fischer, Edward E.; Eash, David A.

2010-01-01

Major flooding occurred June 8-9, 2008, in the Upper Iowa River Basin in northeast Iowa following severe thunderstorm activity over the region. About 7 inches of rain were recorded for the 48-hour period ending 4 p.m., June 8, at Decorah, Iowa; more than 7 inches of rain were recorded for the 48-hour period ending 7 a.m., June 8, at Dorchester, Iowa, about 17 miles northeast of Decorah. The maximum peak discharge measured in the Upper Iowa River was 34,100 cubic feet per second at streamgage 05387500 Upper Iowa River at Decorah, Iowa. This discharge is the largest discharge recorded in the Upper Iowa River Basin since streamgaging operations began in the basin in 1914. The flood-probability range of the peak discharge is 0.2 to 1 percent. High-water marks were measured at 15 locations along the Upper Iowa River between State Highway 26 near the mouth at the Mississippi River and U.S. Highway 63 at Chester, Iowa, a distance of 124 river miles. The high-water marks were used to develop a flood profile.

Scaling up watershed model parameters--Flow and load simulations of the Edisto River Basin

USGS Publications Warehouse

Feaster, Toby D.; Benedict, Stephen T.; Clark, Jimmy M.; Bradley, Paul M.; Conrads, Paul

2014-01-01

The Edisto River is the longest and largest river system completely contained in South Carolina and is one of the longest free flowing blackwater rivers in the United States. The Edisto River basin also has fish-tissue mercury concentrations that are some of the highest recorded in the United States. As part of an effort by the U.S. Geological Survey to expand the understanding of relations among hydrologic, geochemical, and ecological processes that affect fish-tissue mercury concentrations within the Edisto River basin, analyses and simulations of the hydrology of the Edisto River basin were made with the topography-based hydrological model (TOPMODEL). The potential for scaling up a previous application of TOPMODEL for the McTier Creek watershed, which is a small headwater catchment to the Edisto River basin, was assessed. Scaling up was done in a step-wise process beginning with applying the calibration parameters, meteorological data, and topographic wetness index data from the McTier Creek TOPMODEL to the Edisto River TOPMODEL. Additional changes were made with subsequent simulations culminating in the best simulation, which included meteorological and topographic wetness index data from the Edisto River basin and updated calibration parameters for some of the TOPMODEL calibration parameters. Comparison of goodness-of-fit statistics between measured and simulated daily mean streamflow for the two models showed that with calibration, the Edisto River TOPMODEL produced slightly better results than the McTier Creek model, despite the significant difference in the drainage-area size at the outlet locations for the two models (30.7 and 2,725 square miles, respectively). Along with the TOPMODEL hydrologic simulations, a visualization tool (the Edisto River Data Viewer) was developed to help assess trends and influencing variables in the stream ecosystem. Incorporated into the visualization tool were the water-quality load models TOPLOAD, TOPLOAD-H, and LOADEST. Because the focus of this investigation was on scaling up the models from McTier Creek, water-quality concentrations that were previously collected in the McTier Creek basin were used in the water-quality load models.

Crustal controls on magmatic-hydrothermal systems: A geophysical comparison of White River, Washington, with Goldfield, Nevada

USGS Publications Warehouse

Blakely, R.J.; John, D.A.; Box, S.E.; Berger, B.R.; Fleck, R.J.; Ashley, R.P.; Newport, G.R.; Heinemeyer, G.R.

2007-01-01

The White River altered area, Washington, and the Goldfield mining district, Nevada, are nearly contemporaneous Tertiary (ca.20 Ma) calc-alkaline igneous centers with large exposures of shallow (<1 km depth) magmatic-hydrothermal, acid-sulfate alteration. Goldfield is the largest known high-sulfidation gold deposit in North America. At White River, silica is the only commodity exploited to date, but, based on its similarities with Goldfield, White River may have potential for concealed precious and/or base metal deposits at shallow depth. Both areas are products of the ancestral Cascade arc Goldfield lies within the Great Basin physiographic province in an area of middle Miocene and younger Basin and Range and Walker Lane faulting, whereas White River is largely unaffected by young faults. However, west-northwest-striking magnetic anomalies at White River do correspond with mapped faults synchronous with magmatism, and other linear anomalies may reflect contemporaneous concealed faults. The White River altered area lies immediately south of the west-northwest-striking White River fault zone and north of a postulated fault with similar orientation. Structural data from the White River altered area indicate that alteration developed synchronously with an anomalous stress field conducive to left-lateral, strike-slip displacement on west-north-west-striking faults. Thus, the White River alteration may have developed in a transient transtensional region between the two strike-slip faults, analogous to models proposed for Goldfield and other mineral deposits in transverse deformational zones. Gravity and magnetic anomalies provide evidence for a pluton beneath the White River altered area that may have provided heat and fluids to overlying volcanic rocks. East- to east- northeast-striking extensional faults and/or fracture zones in the step-over region, also expressed in magnetic anomalies, may have tapped this intrusion and provided vertical and lateral transport of fluids to now silicified areas. By analogy to Goldfield, geophysical anomalies at the White River altered area may serve as proxies for geologic mapping in identifying faults, fractures, and intrusions relevant to hydrothermal alteration and ore formation in areas of poor exposure. ?? 2006 Geological Society of America.

Post-project geomorphic assessment of a large process-based river restoration project

USGS Publications Warehouse

Erwin, Susannah O.; Schmidt, John C.; Allred, Tyler M.

2016-01-01

This study describes channel changes following completion of the Provo River Restoration Project (PRRP), the largest stream restoration project in Utah and one of the largest projects in the United States in which a gravel-bed river was fully reconstructed. We summarize project objectives and the design process, and we analyze monitoring data collected during the first 7 years after project completion. Post-project channel adjustment during the study period included two phases: (i) an initial phase of rapid, but small-scale, adjustment during the first years after stream flow was introduced to the newly constructed channel and (ii) a subsequent period of more gradual topographic adjustment and channel migration. Analysis of aerial imagery and ground-survey data demonstrate that the channel has been more dynamic in the downstream 4 km where a local source contributes a significant annual supply of bed material. Here, the channel migrates and exhibits channel adjustments that are more consistent with project objectives. The upstream 12 km of the PRRP are sediment starved, the channel has been laterally stable, and this condition may not be consistent with large-scale project objectives.

Earth observation taken by the Expedition 29 crew

NASA Image and Video Library

2011-09-17

ISS029-E-008032 (17 Sept. 2011) --- Fires along the Rio Xingu, Brazil are featured in this image photographed by an Expedition 29 crew member on the International Space Station. The rain forest of South America, also known as ?Amazonia??the largest such forest on Earth?has been undergoing a continual and accelerated land use conversion process into farmlands (including pasture for livestock) since the early 1960s. This process has typically been achieved by clearing of the forest using fire ? ?slash and burn? ? followed by planting of crops. The generally infertile soils of the region make sustainable farming difficult; this drives more forest conversion into new farmland. The area of clearing can be considerable, and as the deforested regions are easily identifiable and measurable from space the rate of deforestation is likewise easy to track. This detailed photograph illustrates slash-and-burn forest clearing along the Xingu River (Rio) in the northeast of the state of Matto Grasso, Brazil. The perspective of this image allows for a striking visualization of both the horizontal position and extent of the fire lines next to the river, as well as providing a sense of the vertical structure of the smoke plumes due to the viewing angle and shadowing. Light colored areas within the river channel are sand bars, which show that the river is in its annual low-flow/ low water stage. For a sense of scale, the Xingu River channel within the view is approximately 63 kilometers long. Rivers in Amazonia are its natural highways, which may explain why the burning is occurring right next to the Xingu River, one of Amazonia?s largest. In recent years, preservation has gained traction in the region as a result of such considerations as new valuation of the ecosystem services provided by the forest, concerns about the impact of widespread burning on global climate change, and greater sensitivity to the ethnic and biological heritage of Amazonia.

River mixing in the Amazon as a driver of concentration-discharge relationships

NASA Astrophysics Data System (ADS)

Moquet, Jean-Sébastien; Bouchez, Julien; Carlo Espinoza, Jhan; Martinez, Jean-Michel; Guyot, Jean-Loup; Lagane, Christelle; Filizola, Naziano; Aniceto, Keila; Noriega, Luis; Hidalgo Sanchez, Liz; Pombosa, Rodrigo; Fraizy, Pascal; Santini, William; Timouk, Franck; Vauchel, Philippe

2017-04-01

Large hydrological systems such as continental-scale river basins aggregate water from compositionally different tributaries. Here we explore how such aggregation can affect solute concentration-discharge (C-Q) relationships and thus obscure the message carried by these relationships in terms of weathering properties of the Critical Zone. We compute 10 day-frequency time series of Q and major solute (Si, Ca2+, Mg2+, K+, Na+, Cl-, SO42-) C and fluxes (F) for 13 gauging stations of the SNO-HYBAM Monitoring Program (Geodynamical, hydrological and Biogeochemical control of erosion/weathering and material transport in the Amazon, Orinoco and Congo basins) located throughout the Amazon basin, the largest river basin in the world. Concentration-discharge relationships vary in a systematic manner, shifting for most solutes from a nearly "chemostatic" behavior (constant C) at the Andean mountain front to a more "dilutional" pattern (negative C-Q relationship) towards the system mouth. Associated to this shift in trend is a shift in shape: C-Q hysteresis becomes more prominent at the most downstream stations. A simple model of tributary mixing allows us to identify the important parameters controlling C-Q trends and shapes in the mixture, and we show that for the Amazon case, the model results are in qualitative agreement with the observations. Altogether, this study suggests that mixing of water and solutes between different flowpaths leads to altered C-Q relationships.

Recovery of the Three-Gorges Reservoir Impoundment Signal from ICESat altimetry and GRACE

NASA Astrophysics Data System (ADS)

Carabajal, C. C.; Boy, J.; Luthcke, S. B.; Harding, D. J.; Rowlands, D. D.; Lemoine, F. G.

2006-12-01

The Three Gorges Dam along the Yangtze River in China is one of the largest dams in the world. The water impoundment of the Three-Gorges Reservoir started in June 2003, and the volume of water will continuously increase up to about 40 km3 in 2009, over a length of about 600 km. Although water-level changes along the Yangtze River and the Three Gorges Reservoir are measured by in situ water gauges, access to these data can be quite difficult. Estimates of inland water height and extent can also be recovered from altimetry measurements performed from satellite platforms, such as those acquired by the Geoscience laser Altimetry System (GLAS) on board the Ice, Cloud and Land Elevation Satellite (ICESat). ICESat has produced a comprehensive, highly precise, set of along-track elevation measurements, every three months since its launch in 2003, which intersect the Yangtze River along its East-West extent. In addition, the water impoundment of major artificial reservoirs induces variations of global geodetic quantities, such as the gravity field and Earth rotation (Chao, 1995, Boy & Chao, 2002). Water level changes within the reservoir are compared to GRACE (Gravity Recovery And Climate Experiment) recovered water mass changes. In addition, we compare the GRACE observations of mass change in the Yangtze region to hydrological changes computed from different global soil-moisture and snow models, such as GLDAS (Global Land Data Assimilation System).

Origin of Atlantic Sturgeon collected off the Delaware coast during spring months

USGS Publications Warehouse

Wirgin, Isaac; Breece, Matthew W.; Fox, Dewayne A.; Maceda, Lorraine; Wark, Kevin W.; King, Timothy L.

2015-01-01

Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus was federally listed under the U.S. Endangered Species Act as five distinct population segments (DPS). Currently, at least 18 estuaries coastwide host spawning populations and the viability of these vary, requiring differing levels of protection. Subadults emigrate from their natal estuaries to marine waters where they are vulnerable to bycatch; one of the major threats to the rebuilding of populations. As a result, identifying the population origin of Atlantic Sturgeon in coastal waters is critical to development of management plans intended to minimize interactions of the most imperiled populations with damaging fisheries. We used mitochondrial DNA control region sequencing and microsatellite DNA analyses to determine the origin of 261 Atlantic Sturgeon collected off the Delaware coast during the spring months. Using individual-based assignment (IBA) testing and mixed stock analysis, we found that specimens originated from all nine of our reference populations and the five DPSs used in the listing determination. Using IBA, we found that the Hudson River population was the largest contributor (38.3%) to our coastal collection. The James (19.9%) and Delaware (13.8%) river populations, at one time thought to be extirpated or nearly so, were the next largest contributors. The three populations combined in the South Atlantic DPS contributed 21% of specimens; the Altamaha River, the largest population in the South Atlantic DPS, only contributed a single specimen to the collection. While the origin of specimens collected on the Delaware coast was most likely within rivers of the New York Bight DPS (52.1%), specimens that originated elsewhere were also well represented. Genetic analyses provide a robust tool to identify the population origin of individual sturgeon outside of their natal estuaries and to determine the quantitative contributions of individual populations to coastal aggregations that are vulnerable to bycatch and other anthropogenic threats.

Assessing the combined effects of urbanisation and climate change on the river water quality in an integrated urban wastewater system in the UK.

PubMed

Astaraie-Imani, Maryam; Kapelan, Zoran; Fu, Guangtao; Butler, David

2012-12-15

Climate change and urbanisation are key factors affecting the future of water quality and quantity in urbanised catchments and are associated with significant uncertainty. The work reported in this paper is an evaluation of the combined and relative impacts of climate change and urbanisation on the receiving water quality in the context of an Integrated Urban Wastewater System (IUWS) in the UK. The impacts of intervening system operational control parameters are also investigated. Impact is determined by a detailed modelling study using both local and global sensitivity analysis methods together with correlation analysis. The results obtained from the case-study analysed clearly demonstrate that climate change combined with increasing urbanisation is likely to lead to worsening river water quality in terms of both frequency and magnitude of breaching threshold dissolved oxygen and ammonium concentrations. The results obtained also reveal the key climate change and urbanisation parameters that have the largest negative impact as well as the most responsive IUWS operational control parameters including major dependencies between all these parameters. This information can be further utilised to adapt future IUWS operation and/or design which, in turn, should make these systems more resilient to future climate and urbanisation changes. Copyright © 2012 Elsevier Ltd. All rights reserved.

A high-resolution global-scale groundwater model

NASA Astrophysics Data System (ADS)

de Graaf, I. E. M.; Sutanudjaja, E. H.; van Beek, L. P. H.; Bierkens, M. F. P.

2015-02-01

Groundwater is the world's largest accessible source of fresh water. It plays a vital role in satisfying basic needs for drinking water, agriculture and industrial activities. During times of drought groundwater sustains baseflow to rivers and wetlands, thereby supporting ecosystems. Most global-scale hydrological models (GHMs) do not include a groundwater flow component, mainly due to lack of geohydrological data at the global scale. For the simulation of lateral flow and groundwater head dynamics, a realistic physical representation of the groundwater system is needed, especially for GHMs that run at finer resolutions. In this study we present a global-scale groundwater model (run at 6' resolution) using MODFLOW to construct an equilibrium water table at its natural state as the result of long-term climatic forcing. The used aquifer schematization and properties are based on available global data sets of lithology and transmissivities combined with the estimated thickness of an upper, unconfined aquifer. This model is forced with outputs from the land-surface PCRaster Global Water Balance (PCR-GLOBWB) model, specifically net recharge and surface water levels. A sensitivity analysis, in which the model was run with various parameter settings, showed that variation in saturated conductivity has the largest impact on the groundwater levels simulated. Validation with observed groundwater heads showed that groundwater heads are reasonably well simulated for many regions of the world, especially for sediment basins (R2 = 0.95). The simulated regional-scale groundwater patterns and flow paths demonstrate the relevance of lateral groundwater flow in GHMs. Inter-basin groundwater flows can be a significant part of a basin's water budget and help to sustain river baseflows, especially during droughts. Also, water availability of larger aquifer systems can be positively affected by additional recharge from inter-basin groundwater flows.

Using Eco-hydrologic modeling in the Penobscot River Watershed to explore the role of climate and land use change on DOC concentration and flux

NASA Astrophysics Data System (ADS)

Rouhani, S. F. B. B.; Schaaf, C.; Douglas, E. M.; Huntington, T. G.; Kim, J.

2017-12-01

Dissolved Organic Carbon leaches from the terrestrial watersheds to serve as one of the largest sources of marine DOC. Runoff, slope, soil organic matter and land cover characteristics are the primary spatial factors controlling the variability of fluvial Dissolved Organic Carbon fluxes through the catchment. In large, more heterogeneous catchments, streamflow dissolved organic carbon dynamics are regulated by the combined effect of hydrological mechanisms and the proportion of major landscape elements, such as wetland and forested areas. A number of studies have demonstrated that the amount of wetlands, especially peatlands, controls the watershed level transport of DOC in streams.The Penobscot River Watershed is located in north-central Maine and drains into the Gulf of Maine. It is the second largest watershed in New England. The Penobscot River Watershed is primarily forested but also contains extensive bogs, marshes, and wooded swamps.Studying the spatial and temporal changes in DOC export in the Penobscot River Watershed allows us to better understand and detect carbon sinks to carbon source shifts (or vice versa) in northern forested ecosystems.The Regional Hydro-Ecological Simulation System, is a physical process based terrestrial model that has the ability to simulate both the source and transportation of DOC by combining both hydrological and ecological processes. The study is focused on simulating the DOC concentration and flux with RHESSys in the Penobscot River Watershed. The simulated results are compared with field measurements of DOC from the watershed and the model results from the LOADEST and the temporal DOC export patterns are explored. Future changes in the amount of streamflow DOC will also be investigated by using projected land cover and climate change scenarios. Incremental increases in the loss of wetland areas have been implemented to explore the sensitivity of this watershed to wetland loss and progressive changes in forested land cover have been implemented to understand the role of vegetation types to the DOC flux.The simulated daily streamflow for the period of 2004-2013 corresponded well with observed daily streamflowat USGS gauge station. in addition, the simulated DOC flux and concentration values matched well with observed data and LODEST model results.

American River Hydrologic Observatory

NASA Astrophysics Data System (ADS)

Glaser, S. D.; Bales, R. C.; Conklin, M. H.

2016-12-01

We have set up fourteen large wireless sensor networks to measure hydrologic parameters over physiographical representative regions of the snow-dominated portion of the river basin. This is perhaps the largest wireless sensor network in the world. Each network covers about a 1 km2 area and consists of about 45 elements. We measure snow depth, temperature humidity soil moisture and temperature, and solar radiation in real time at ten locations per site, as opposed to the traditional once-a-month snow course. As part of the multi-PI SSCZO, we have installed a 62-node wireless sensor network to measure snow depth, temperature humidity soil moisture and temperature, and solar radiation in real time. This network has been operating for approximately six years. We are now installing four large wireless sensor networks to measure snow depth, temperature humidity soil moisture and temperature, and solar radiation in East Branch of the North Fork of the Feather River, CA. The presentation will discuss the planning and operation of the networks as well as some unique results. It will also present information about the networking hardware designed for these installations, which has resulted in a start-up, Metronome Systems.

Management to Insulate Ecosystem Services from the Effects of Catchment Development

NASA Astrophysics Data System (ADS)

Gell, Peter

2018-02-01

Natural ecosystems provide amenity to human populations in the form of ecosystem services. These services are grouped into four broad categories: provisioning - food and water production; regulating - control of climate and disease; supporting - crop pollination; and cultural - spiritual and recreational benefits. Aquatic systems provide considerable service through the provision of potable water, fisheries and aquaculture production, nutrient mitigation and the psychological benefits that accrue from the aesthetic amenity provided from lakes, rivers and other wetlands. Further, littoral and riparian ecosystems, and aquifers, protect human communities from sea level encroachment, and tidal and river flooding. Catchment and water development provides critical resources for human consumption. Where these provisioning services are prioritized over others, the level and quality of production may be impacted. Further, the benefits from these provisioning services comes with the opportunity cost of diminishing regulating, supporting and cultural services. This imbalance flags concerns for humanity as it exceeds recognised safe operating spaces. These concepts are explored by reference to long term records of change in some of the world's largest river catchments and lessons are drawn that may enable other communities to consider the balance of ecosystems services in natural resource management.

John Day River Sub-Basin Fish Habitat Enhancement Project; 2008 Annual Report

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

Powell, Russ M.; Alley, Pamela D.; Goin Jr, Lonnie

Work undertaken in 2008 included: (1) Seven new fence projects were completed thereby protecting approximately 10.97 miles of streams with 16.34 miles of riparian fence; (2) Renewal of one expired lease was completed thereby continuing to protect 0.75 miles of stream with 1.0 mile of riparian fence. (3) Maintenance of all active project fences (106.54 miles), watergaps (78), spring developments (33) were checked and repairs performed; (3) Planted 1000 willow/red osier on Fox Creek/Henslee property; (4) Planted 2000 willows/red osier on Middle Fork John Day River/Coleman property; (5) Planted 1000 willow/red osier cuttings on Fox Creek/Johns property; (6) Since themore » initiation of the Fish Habitat Project in 1984 we have 126.86 miles of stream protected using 211.72 miles of fence protecting 5658 acres. The purpose of the John Day Fish Habitat Enhancement Program is to enhance production of indigenous wild stocks of spring Chinook and summer steelhead within the sub basin through habitat protection, enhancement and fish passage improvement. The John Day River system supports the largest remaining wild runs of spring chinook salmon and summer steelhead in Northeast Oregon.« less

View of Argentina-Paraguay border area of South America

NASA Image and Video Library

1973-08-30

SL3-33-167 (July-September 1973) --- A vertical view of the Argentina-Paraguay border area of South America as photographed from Earth orbit by one of the six lenses of the Itek-furnished S190-A Multispectral Photographic Facility Experiment aboard the Skylab space station. This picture was taken with type 2443 infrared color film. The Parana River flows from east to west across the picture. This part of the Rio Parana is located between the towns of Posadas, Argentina, and Resistencia, Argentina. The major body of water in the large swamp area is Laguna Ibera. Note the several fires burning in this area. The largest land mass (Argentina) is south of the river. Paraguay is north of the river. Isla Apipe Grande is near the center of the photograph. The S190-A experiment is part of the Skylab Earth Resources Experiments Package. Federal agencies participating with NASA on the EREP project are the Departments of Agriculture, Commerce, Interior, the Environmental Protection Agency and the Corps of Engineers. All EREP photography is available to the public through the Department of Interior?s Earth Resources Observations Systems Data Center, Sioux Falls, South Dakota, 57198. Photo credit: NASA

Water quality evaluation of Al-Gharraf river by two water quality indices

NASA Astrophysics Data System (ADS)

Ewaid, Salam Hussein

2017-11-01

Water quality of Al-Gharraf river, the largest branch of Tigris River south of Iraq, was evaluated by the National Sanitation Foundation Water Quality Index (NFS WQI) and the Heavy Metal Pollution Index (HPI) depending on 13 physical, chemical, and biological parameters of water quality measured monthly at ten stations on the river during 2015. The NSF-WQI range obtained for the sampling sites was 61-70 indicating a medium water quality. The HPI value was 98.6 slightly below the critical value for drinking water of 100, and the water quality in the upstream stations is better than downstream due to decrease in water and the accumulation of contaminants along the river. This study explains the significance of applying the water quality indices that show the aggregate impact of ecological factors in charge of water pollution of surface water and which permits translation of the monitoring data to assist the decision makers.

Spatial and temporal patterns of precipitation and stream flow variations in Tigris-Euphrates river basin.

PubMed

Daggupati, Prasad; Srinivasan, Raghavan; Ahmadi, Mehdi; Verma, Deepa

2017-01-01

Tigris and Euphrates river basin (TERB) is one of the largest river basins in the Middle East, and the precipitation (in the form of snowfall) is a major source of streamflow. This study investigates the spatial and temporal variability of precipitation and streamflow in TERB to better understand the hydroclimatic variables and how they varied over time. The precipitation shows a decreasing trend with 1980s being wetter and 2000s being drier. A total of 55 and 40% reduction in high flows in Tigris and Euphrates rivers at T20 and E3 was seen in post-reservoir period. A lag time of 3 to 4 and 5 to 6 months was estimated between peak snowfall and runoff time periods. Decreasing precipitation and streamflow along with several planned dams could hamper the sustainability of several Mesopotamian marshlands that completely depend on the water from the Tigris and Euphrates rivers.

Application of the satellite system of the earth's gravity field measurement (GRACE) for the evaluation of water balance in large Russian river catchments

NASA Astrophysics Data System (ADS)

Frolova, Natalia; Zotov, Leonid; Grigoriev, Vadim; Sazonov, Alexey; Kireeva, Maria; Krylenko, Inna

2017-04-01

Space-based Earth observing systems provided a substantially large amount of information to the scientific community in recent decades. Cumulative effects of redistribution of masses in the Earth system can be seen in the changes of the gravity field of the Earth. Gravity Recovery and Climate Experiment (GRACE) satellites, launched 17.03.2002 from Plesetsk, provide a set of monthly Earth's gravity field observations. GRACE data is very useful for hydrological and climatological studies, especially over large territory, not completely covered by the meteorological and hydrological networks, like Russia. Possible application of the satellite gravity survey data obtained under the GRACE for solving various hydrological problems is discussed. The GRACE-based monthly gravity field data are transformed into the maps of water level equivalent and averaged for the catchments of the largest rivers of Russia. The temporal variability of the parameter is analyzed. Possible application of the GRACE data for the evaluation of particular components of water balance within the largest river basins of the European part of Russia is discussed. After averaging over 15 large Russian rivers basins annual component shows amplitude increase since 2009. Trend component grows until 2009 and then reaches a plateau. It is mostly dominated by Siberian rivers. Map for the trend show gravity field increase in Siberia, at Back Sea and decrease over Caspian Sea since 2003. GRACE satellite gravimetry data can be used for estimating terrestrial water storage (TWS) in a river basin scale. Terrestrial water storage (TWS) is the integrated sum of all basin storages (surface water bodies, soil and ground aquifer, snowpack and glaciers) and the ability to estimate TWS dynamics is useful for understanding the basin's water cycle, its interconnection with the local climate, physics of predictability of extreme hydrological events. Despite the importance of the TWS estimates, reliable ground-based monitoring data of all TWS components are scarce or absent at all. Since observations are not sufficient to monitor TWS, hydrological models are considered as a comprehensive tool to simulate TWS components at a basin scale. However accuracy of the model-derived TWS is influenced by the uncertainty of the model structure and parameters, reliability of input data, etc. To improve the TWS-estimates, it is reasonable to combine the simulated TWS with independent observations provided by the GRACE gravity data. Ninety-seven monthly TWS retrieval from GRACE data (from April 2002 to December 2009) was examined and compared with TWS-estimates obtained by the ECOMAG hydrological model simulations. The case study was carried out for the Northern Dvina River basin. Quantitative analyze between the hydrological model and GRACE-based TWS showed that latter is in good consistency with the simulation results on both seasonal and inter-annual time scales. Overall, the results highlight the benefit of assimilating GRACE data for hydrological applications, particularly in data-sparse regions, while also providing insight on future refinements of the methodology of GRACE-data application in watershed hydrology. The study is financially supported by the Russian Foundation for Basic Research (Proj.№ 16-35-60080; 16-05-00753) and the Russian Science Foundation (Grant No. 14-17-00155).

Sustainable management of river oases along the Tarim River in North-Western China under conditions of climate change

NASA Astrophysics Data System (ADS)

Rumbaur, C.; Thevs, N.; Disse, M.; Ahlheim, M.; Brieden, A.; Cyffka, B.; Doluschitz, R.; Duethmann, D.; Feike, T.; Frör, O.; Gärtner, P.; Halik, Ü.; Hill, J.; Hinnenthal, M.; Keilholz, P.; Kleinschmit, B.; Krysanova, V.; Kuba, M.; Mader, S.; Menz, C.; Othmanli, H.; Pelz, S.; Schroeder, M.; Siew, T. F.; Stender, V.; Stahr, K.; Thomas, F. M.; Welp, M.; Wortmann, M.; Zhao, X.; Chen, X.; Jiang, T.; Zhao, C.; Zhang, X.; Luo, J.; Yimit, H.; Yu, R.

2014-10-01

The Tarim River Basin, located in Xinjiang, NW China, is the largest endorheic river basin of China and one of the largest in whole Central Asia. Due to the extremely arid climate with an annual precipitation of less than 100 mm, the water supply along the Aksu and Tarim River solely depends on river water. This applies for anthropogenic activities (e.g. agriculture) as well as for the natural ecosystems so that both compete for water. The on-going increase of water consumption by agriculture and other human activities in this region has been enhancing the competition for water between human needs and nature. Against this background, 11 German and 6 Chinese universities and research institutes formed the consortium SuMaRiO (www.sumario.de), which aims at gaining a holistic picture of the availability of water resources in the Tarim River Basin and the impacts on anthropogenic activities and natural ecosystems caused by the water distribution within the Tarim River Basin. The discharge of the Aksu River, which is the major tributary to the Tarim, has been increasing over the past 6 decades due to enhanced glacier melt. Alone from 1989 to 2011, the area under agriculture more than doubled. Thereby, cotton became the major crop and there was a shift from small-scale farming to large-scale intensive farming. The major natural ecosystems along the Aksu and Tarim River are riparian ecosystems: Riparian (Tugai) forests, shrub vegetation, reed beds, and other grassland. Within the SuMaRiO Cluster the focus was laid on the Tugai forests, with Populus euphratica as dominant tree, because the most productive and species-rich natural ecosystems can be found among those forests. On sites with groundwater distance of less than 7.5 m the annual increments correlated with river runoffs of the previous year. But, the further downstream along the Tarim River, the more the natural river dynamics ceased, which impacts on the recruitment of Populus euphratica. Household surveys revealed that there is a considerable willingness to pay for conservation of those riparian forests with the mitigation of dust and sandstorms considered as the most important ecosystem service. This interdisciplinary project will result in a decision support tool (DST), build on the participation of regional stakeholders and models based on results and field experiments. This DST finally shall assist stakeholders in balancing the water competition acknowledging the major external effects of any water allocation.

Occurrence and toxicity of Microcystis aeruginosa (Cyanobacteria) in the Paraná River, downstream of the Yacyretá dam (Argentina).

PubMed

Forastier, Marina Elizabet; Zalocar, Yolanda; Andrinolo, Dario; Domitrovic, Hugo Alberto

2016-03-01

Cyanobacteria constitute the main toxin producers in inland water ecosystems and have extensive global distribution. The presence of hepatotoxins in aquatic environments is hazardous to human and animal health; even though the presence and identification of hepatotoxic microcystins in rivers and reservoirs of the world have been confirmed by several studies in the last few years. Herein, we studied the abundance and toxicity of Microcystis aeruginosa in the Argentine section of the Paraná River at the beginning of the Middle Paraná (Corrientes Hydrometer), near Corrientes city (27º28´ S - 58º51´ W) and approximately 220 km downstream of the Yacyretá dam (High Paraná). The Paraná River basin, with a drainage area of 3.1 x 10(6) km(2) and 3 965 km in length, is the second largest catchment of South America, after that of the Amazon. The Paraná River is the main source of drinking water supply for the Northeastern Argentine region. Phytoplankton samples were collected and environmental variables were measured in a monthly basis (exceptionally fortnightly), from March 2004 to June 2008. Fifty-eight samples were analyzed for phytoplankton density and biomass. Five samples were used for toxicity testing; the latter were obtained during the cyanobacteria blooms from 2005 to 2008. Phytoplankton counts were performed with an inverted microscope, and biomass was expressed as biovolume. Bioassays with mice and high-performance liquid chromatography (HPLC) analysis were performed to evaluate the presence of cyanotoxins. Phytoplankton mainly consisted of Cryptophyta, Chlorophyta and Bacillariophyta. Microcystis aeruginosa was identified during the warmer months each year (November to March). Density varied between 189 and 25 027 cells/mL (1-10 colonies/mL) and biomass from 0.34 to 44 mm(3)/L. Taking into account the number of cells, the highest abundance occurred in April 2004 (25 027 cells/mL), coinciding with the largest biovolume (44 mm(3)/L). All mice subjected to intraperitoneal injections with samples obtained during bloom episodes showed positive results for the presence of hepatotoxins. Three microcystins variants: LR, RR and [D-Leu(1)] Mcyst-LR were detected by analysis with semi-preparative high-performance liquid chromatography with diode array detector system (HPLC-PDA). This constitutes the first report of microcystins recorded during M. aeruginosa blooms in the Argentine stretch of the Paraná River at the beginning of the Middle Paraná (Corrientes Hydrometer), approximately 220 km downstream of the Yacyretá dam (High Paraná).

Temperature Effects of Point Sources, Riparian Shading, and Dam Operations on the Willamette River, Oregon

USGS Publications Warehouse

Rounds, Stewart A.

2007-01-01

Water temperature is an important factor influencing the migration, rearing, and spawning of several important fish species in rivers of the Pacific Northwest. To protect these fish populations and to fulfill its responsibilities under the Federal Clean Water Act, the Oregon Department of Environmental Quality set a water temperature Total Maximum Daily Load (TMDL) in 2006 for the Willamette River and the lower reaches of its largest tributaries in northwestern Oregon. As a result, the thermal discharges of the largest point sources of heat to the Willamette River now are limited at certain times of the year, riparian vegetation has been targeted for restoration, and upstream dams are recognized as important influences on downstream temperatures. Many of the prescribed point-source heat-load allocations are sufficiently restrictive that management agencies may need to expend considerable resources to meet those allocations. Trading heat allocations among point-source dischargers may be a more economical and efficient means of meeting the cumulative point-source temperature limits set by the TMDL. The cumulative nature of these limits, however, precludes simple one-to-one trades of heat from one point source to another; a more detailed spatial analysis is needed. In this investigation, the flow and temperature models that formed the basis of the Willamette temperature TMDL were used to determine a spatially indexed 'heating signature' for each of the modeled point sources, and those signatures then were combined into a user-friendly, spreadsheet-based screening tool. The Willamette River Point-Source Heat-Trading Tool allows the user to increase or decrease the heating signature of each source and thereby evaluate the effects of a wide range of potential point-source heat trades. The predictions of the Trading Tool were verified by running the Willamette flow and temperature models under four different trading scenarios, and the predictions typically were accurate to within about 0.005 degrees Celsius (?C). In addition to assessing the effects of point-source heat trades, the models were used to evaluate the temperature effects of several shade-restoration scenarios. Restoration of riparian shade along the entire Long Tom River, from its mouth to Fern Ridge Dam, was calculated to have a small but significant effect on daily maximum temperatures in the main-stem Willamette River, on the order of 0.03?C where the Long Tom River enters the Willamette River, and diminishing downstream. Model scenarios also were run to assess the effects of restoring selected 5-mile reaches of riparian vegetation along the main-stem Willamette River from river mile (RM) 176.80, just upstream of the point where the McKenzie River joins the Willamette River, to RM 116.87 near Albany, which is one location where cumulative point-source heating effects are at a maximum. Restoration of riparian vegetation along the main-stem Willamette River was shown by model runs to have a significant local effect on daily maximum river temperatures (0.046 to 0.194?C) at the site of restoration. The magnitude of the cooling depends on many factors including river width, flow, time of year, and the difference in vegetation characteristics between current and restored conditions. Downstream of the restored reach, the cooling effects are complex and have a nodal nature: at one-half day of travel time downstream, shade restoration has little effect on daily maximum temperature because water passes the restoration site at night; at 1 full day of travel time downstream, cooling effects increase to a second, diminished maximum. Such spatial complexities may complicate the trading of heat allocations between point and nonpoint sources. Upstream dams have an important effect on water temperature in the Willamette River system as a result of augmented flows as well as modified temperature releases over the course of the summer and autumn. The TMDL was formulated prior t

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.

Back-barrier and seabed sediment dynamics in the Albemarle-Pamlico estuarine system, North Carolina

NASA Astrophysics Data System (ADS)

Walsh, J. P.; Corbett, D. R.

2016-02-01

Estuaries are critical habitats as well as places where people live, recreate, and make their livelihood. Additionally, they are sites where land and sea interact, and sediments, and associated pollutants and carbon, are deposited, remobilized and accumulated. Many processes, such as river discharge, waves, tides, and sea-level rise, are operating in estuaries to cause sediment dynamics, impacting humans and organisms as a result. Recent research we have been engaged in across the Albemarle-Pamlico Estuarine System (APES) has investigated the sediments dynamics of this important estuary. The APES is the second largest estuary in the continental United States, consisting of the Albemarle and Pamlico sounds and the Pamlico River and Neuse River sub-estuaries. Although expansive in size, the system is shallow with minimal tidal range. Water and sediment discharge into the APES is modest, and the existence of few inlets along the Outer Banks limits mixing with the Atlantic Ocean. Human impact on the drainage basin and estuarine system is moderate and increasing over time. Over the last five years, a considerable volume of sedimentary process data has been collected over various timescales and locations in the APES. More specifically, work has included: deployments of instrumented tripods to examine seabed dynamics; collection and analysis of shallow cores and GIS investigation of aerial photographs and other data. This wealth of data highlights several insights: 1) shorelines are generally eroding ( 0.25 m/y and rapidly >3 m/y in places), but rates are temporally and spatially variable; 2) seabed resuspension is frequent, yet net accumulation of 2-4 mm/y is widespread in deeper locations; and 3) storms cause episodic, localized impacts (e.g., barrier breaches) on this large, shallow estuarine system.

Variation in stable isotopes of freshwater mussel shells in a Kentucky river system

NASA Astrophysics Data System (ADS)

Erhardt, A. M.; Haag, W.; Price, S.; Weisrock, D.

2017-12-01

Isotopic signatures in freshwater mussel shells can reflect environmental differences among streams and human impacts on river systems. In the southeastern United States, mussels exhibit extraordinary biodiversity, serve an important role as filter feeders, and are sensitive to environmental change. Additionally, their long life-span (up to 50 years) and seasonal shell deposition can permit high-resolution environmental reconstructions. We examined variation in shell stable isotope values among mussel species and locations throughout the Licking River system in Kentucky. We sampled 8 species at 11 locations. These species represented a range of life-history traits, and locations were distributed among tributaries and the main stem of the Licking River. Samples of the outer organic periostracum layer were analysed for organic δ13C and δ15N, while organic δ15N and inorganic δ13C and δ18O were measured in the inner carbonate portion of the shell. At the same location, preliminary results show variations 2‰ in δ13C and 1‰ in δ15N between different species. We suspect these relationships are due to variations in diet and/or body size. Some, though not all, specimens show variation along the growth axis. For the same species at different locations, preliminary results showed a range of 4‰ in δ13C and 10‰ in δ15N values. Isotope ratios of specimens from the main stem were distinct from those of specimens from the river's largest tributary. Overall, δ13C shows distinct values for each tributary, while δ15N shows a general decline downstream. These variations are likely the result of environmental factors such as the degree of karstification and the ratio of forest to pasture within the catchment. We hope to use this study to identify if any isotopically distinct sources, such as fertilizers or animal manure, contribute to the high nutrient load in these systems. These results represent an exploratory effort to describe watershed-scale and mussel community patterns of isotope variation, allowing us to attempt to unravel the anthropogenic influence on this highly biodiverse and environmentally sensitive organism.

Integrated and Sustainable Water Management of Red-Thai Binh Rivers System Under Change

NASA Astrophysics Data System (ADS)

Giuliani, M.; Anghileri, D.; Castelletti, A.; Mason, E.; Micotti, M.; Soncini-Sessa, R.; Weber, E.

2014-12-01

Vietnam is currently undergoing a rapid economic and demographic development, characterized by internal migrations from the rural areas to the main cities with increasing water demands to guarantee adequate energy and food productions. Hydropower is the primary renewable energy resource in the country, accounting for 33% of the total electric power production, while agriculture contributes for 18% of the national GDP and employs 70% of the population. To cope with this heterogeneous and fast-evolving context, water resources development and management have to be reconsidered by enlarging their scope across sectors and by adopting effective tools to analyze the potential of current and projected infrastructure along with their operating strategies. This work contributes a novel decision-analytic framework based on Multi-Objective Evolutionary Direct Policy Search (MOE-DPS) to support the design of integrated and sustainable water resources management strategies in the Red-Thai Binh River system. The Red River Basin is the second largest basin of Vietnam, with a total area of about 169,000 km2, and comprises three main tributaries and several reservoirs, namely SonLa and HoaBinh on the Da River, ThacBa and TuyenQuang on the Lo River. These reservoirs are regulated for maximizing hydropower production, mitigating flood primarily in Hanoi, and guaranteeing irrigation water supply to the agricultural districts in the delta. The dimensionality of the system and the number of objectives involved increase the complexity of the problem. We address these challenges by combining the MOE-DPS framework with Gaussian radial basis functions policy approximation and the Borg MOEA, which have been demonstrated to guarantee good solutions quality in such many objective policy design problems. Results show that the proposed framework successfully identified alternative management strategies for the system, which explore different tradeoffs among the multi-sector services involved. These solutions are then evaluated under various scenarios of climate change and projected socio-economic conditions to identify their vulnerabilities and, possibly, to design improved operating policies, which are more robust to the future uncertainties.

Vertical Subsurface Flow Mixing and Horizontal Anisotropy in Coarse Fluvial Aquifers: Structural Aspects

NASA Astrophysics Data System (ADS)

Huggenberger, P.; Huber, E.

2014-12-01

Detailed descriptions of the subsurface heterogeneities in coarse fluvial aquifer gravel often lack in concepts to distinguish between the essence and the noise of a permeability structure and the ability to extrapolate site specific hydraulic information at the tens to several hundred meters scale. At this scale the heterogeneity strongly influences the anisotropies of the flow field and the mixing processes in groundwater. However, in many hydrogeological models the complexity of natural systems is oversimplified. Understanding the link between the dynamics of the surface processes of braided-river systems and the resulting subsurface sedimentary structures is the key to characterizing the complexity of horizontal and vertical mixing processes in groundwater. From the different depositional elements of coarse braided-river systems, the largest permeability contrasts can be observed in the scour-fills. Other elements (e.g. different types of gravel sheets) show much smaller variabilities and could be considered as a kind of matrix. Field experiments on the river Tagliamento (Northeast Italy) based on morphological observation and ground-penetrating radar (GPR) surveys, as well as outcrop analyses of gravel pit exposures (Switzerland) allowed us to define the shape, sizes, spatial distribution and preservation potential of scour-fills. In vertical sections (e.g. 2D GPR data, vertical outcrop), the spatial density of remnant erosional bounding surfaces of scours is an indicator for the dynamics of the braided-river system (lateral mobility of the active floodplain, rate of sediment net deposition and spatial distribution of the confluence scours). In case of combined low aggradation rate and low lateral mobility the deposits may be dominated by a complex overprinting of scour-fills. The delineation of the erosional bounding surfaces, that are coherent over the survey area, is based on the identification of angular discontinuities of the reflectors. Fence diagrams and horizontal time-slices from GPR data are used to construct simplified 3D hydraulic properties distribution models and to derive anisotropy patterns. On the basis of this work, conceptual models could be designed and implemented into numerical models to simulate the flow field and mixing in heterogeneous braided-river deposits.

Palaeoflood evidence on the River Nore, South East Ireland

NASA Astrophysics Data System (ADS)

Fleming, Ciara; Turner, Jonathan; Bourke, Mary

2017-04-01

Past geomorphic changes can be detected in sediment sinks, through the investigation of natural sediment archives. Since the advent of palaeoflood hydrology in the 1980s, numerous authors have demonstrated that such sediment deposits record valuable evidence of past flooding events. Many of these studies have focussed on fluvial systems in arid environments, with bedrock channels proving to be particularly successful field sites. In some districts, the collected datasets are now routinely employed to augment analyses of flood frequency and magnitude, which have traditionally relied on extrapolation of short hydrometric datasets. This study targets river reaches in a temperate humid environment, with a predominantly alluvial channel. The River Nore is one of the largest catchments draining South East Ireland. It is situated in a valley with an inherited glacial legacy and is principally a lowland river catchment. Specific morphological zones have been targeted which are optimal for flood deposit preservation, including palaeochannels, tributary junctions and floodplain overbank settings.There are a variety of anthropogenic pressures evident in this landscape. Among them are channelisation of select tributaries, a legacy of coal mining in the upland Carboniferous limestones, and the installation of man-made obstacles or modifications along the length of the river channel such as sluices and weirs. Regarding land-use, the majority of the catchment is dominated by agriculture, mainly pasture with some tillage. This study investigates palaeoflood evidence in the River Nore catchment and examines the development of the river floodplain using a variety of complementary field and desk-based methods. The sub-surface and micro-topography of river reaches are investigated using Ground Penetrating Radar (GPR) and Unmanned Aerial Vehicle (UAV) technology. Flood deposits have been characterised by examination of bank exposures and sediment cores. Installation of sediment traps at discrete locations will enable quantification of sedimentation rates of individual flood events over the winter period 2016/17. Historical Ordnance Survey maps, aerial and satellite imagery have been digitised in a GIS (Geographic Information System) to document channel change over time. Previous authors have noted a paucity of research in fluvial geomorphology in Ireland, particularly in lowland catchments, and this study endeavours to start addressing that gap. Furthermore, in terms of developments in palaeoflood hydrology, this is the first study of its kind in Ireland, attempting to understand and utilise geomorphic evidence of previous flood events in an Irish river catchment.

Is the water level during dry season in Poyang Lake really lower than before?

NASA Astrophysics Data System (ADS)

Liu, Xiaolong; Yu, Meixiu; Shi, Yong; Luan, Zhenyu; Fu, Dafang

2017-04-01

The Poyang Lake, the largest freshwater lake in China, has attracted world widely attentions in recent years due to it being dammed or not at the Lake's outlet. It was reported that the Poyang Lake water levels have been declining significantly in dry seasons, which resulted in severe water supply, irrigation and ecological flow requirement problems. The purpose of the study was to answer the question that the water level of the Poyang Lake during dry season is really lower than before or not. Based on topographical data, and long-term hydrological and meteorological data from 1950 to 2016, the relationship between the Poyang Lake and the Yangtze River before and after the completion of the Three Gorges Dam, the relationship between the Poyang Lake and its Five major tributaries (Ganjiang River, Fuhe River, Xinjiang River, Raohe River and Xiushui River), and as well as sand mining contributions to the water level in dry seasons of the Poyang Lake were investigated respectively.

Paleo-environment in the upper amazon basin during early to middle Miocene times

NASA Astrophysics Data System (ADS)

van Soelen, Els; Hoorn, Carina; Santos, Roberto V.; Dantas, Elton L.; Sinninghe Damsté, Jaap S.; Kim, Jung-Hyun

2014-05-01

The Amazon River has the largest catchment in the world and is responsible for the largest water discharge from land to the ocean. The river system that flows from the Andes to the Atlantic Equatorial Margin exists since the late Miocene, and results from Andean uplift which strongly affected erosion/deposition and major flow patterns in northern South-America. Two outcrop sites from the Solimões basin, Mariñame (17.7-16.1 Ma) and Los Chorros (14.2-12.7 Ma), may shed light on the inland paleo-environmental conditions during a period of active Andean uplift in the early to middle Miocene. Earlier works revealed the Mariñame outcrops to represent a river born in Amazonia. Instead the Los Chorros outcrops are relics of the Amazon River system, characterized by extensive wetlands consisting of swamps, shallow lakes, crevasse splays channels and crevasse-delta lakes (e.g. Hoorn et al., 2010). The freshwater ecosystems alternate with some intervals that are rich in marine palynomorphs (such as dinocysts), mangrove pollen, brackish tolerant molluscs and ostracods, which indicate brackish conditions and a marine influence. It is thought that these marine incursion are related to phases of global sea-level rise and rapid subsidence in the Andean foreland (Marshall & Lundberg, 1996). Still, much remains unknown about the Miocene river systems, like the extent and diversity of the wetland system and the nature of the marine incursions. To get a better understanding of the sources of the (in)organic material, geochemical methods were used. Strontium (Sr) and Neodymium (Nd) isotopes were analyzed on bulk sediments, and used for a paleo-provenance study. The Sr and Nd isotopic signature in the older section (Mariñame) is in general more radiogenic compared to the Los Chorros section. The most radiogenic values are comparable to those found nowadays in the the Precambrian Guyana shield. A Guyana sediment source would suggest a distinctly different flow direction of the major rivers during early-middle Miocene. The younger Los Chorros sediments show Sr and Nd values comparable to those nowadays found in the Solimões region, indicating an Andean source existed already during early-middle Miocene times. Lipid biomarkers were identified and quantified and carbon isotopic compositions of organic matter for whole samples were determined to identify the sources of organic matter. Ratio's between typically terrestrial and aquatic GDGTs indicate shifts between more terrestrial settings and more aquatic settings. Intervals which suggest a more aquatic setting often contain marine palynomorphs and thus could result from a marine incursion at the time. Changes in the overall composition of biomarker lipids at each site reflects the diversity and dynamic features of the wetland. Differences in both provenance and biomarker composition between the two sites demonstrate the diversity within the basin. This diversity could either be geographical diversity since the two sites are located about 380 km from each other. Or, considering the differences in age between the two sites of 2-5 Myrs, it could also reflect the fast changing environmental conditions as a result of Andean uplift. Hoorn, C. et al (2010). The Development of the Amazonian Mega-Wetland (Miocene; Brazil, Colombia, Peru, Bolivia). In: C. Hoorn and F. Wesselingh (eds) Amazonia: Landscape and Species Evolution: A look into the past. Wiley-Blackwell Publishing Ltd., pp. 123- 142. Marshall, L.G., Lundberg, J.G. (1996) Miocene deposits in the Amazonian Foreland Basin. Science 273, 123-124.

The Rivers of the Mississippi Watershed

NASA Image and Video Library

2017-12-08

The Mississippi Watershed is the largest drainage basin in North America at 3.2 million square kilometers in area. The USGS has created a database of this area which indicates the direction of waterflow at each point. By assembling these directions into streamflows, it is possible to trace the path of water from every point of the area to the mouth of the Mississippi in the Gulf of Mexico. This animation starts with the points furthest from the Gulf and reveals the streams and rivers as a steady progression towards the mouth of the Mississippi until all the major rivers are revealed. The speed of the reveal of the rivers is not dependent on the actual speed of the water flow. The reveal proceeds at a constant velocity along each river path, timed so that all reveals reach the mouth of the Mississippi at the same time. This animation does not show actual flow rates of the rivers. All rivers are shown with identical rates. The river colors and widths correspond to the relative lengths of river segments. Credit: NASA's Scientific Visualization Studio/Horace Mitchell Go here to download this video: svs.gsfc.nasa.gov/4493

Predictive Blood Chemistry Parameters for Pansteatitis-Affected Mozambique Tilapia (Oreochromis mossambicus)

PubMed Central

Chapman, Robert W.; Somerville, Stephen E.; Guillette, Matthew P.; Botha, Hannes; Hoffman, Andre; Luus-Powell, Wilmien J.; Smit, Willem J.; Lebepe, Jeffrey; Myburgh, Jan; Govender, Danny; Tucker, Jonathan; Boggs, Ashley S. P.

2016-01-01

One of the largest river systems in South Africa, the Olifants River, has experienced significant changes in water quality due to anthropogenic activities. Since 2005, there have been various “outbreaks” of the inflammatory disease pansteatitis in several vertebrate species. Large-scale pansteatitis-related mortality events have decimated the crocodile population at Lake Loskop and decreased the population at Kruger National Park. Most pansteatitis-related diagnoses within the region are conducted post-mortem by either gross pathology or histology. The application of a non-lethal approach to assess the prevalence and pervasiveness of pansteatitis in the Olifants River region would be of great importance for the development of a management plan for this disease. In this study, several plasma-based biomarkers accurately classified pansteatitis in Mozambique tilapia (Oreochromis mossambicus) collected from Lake Loskop using a commercially available benchtop blood chemistry analyzer combined with data interpretation via artificial neural network analysis. According to the model, four blood chemistry parameters (calcium, sodium, total protein and albumin), in combination with total length, diagnose pansteatitis to a predictive accuracy of 92 percent. In addition, several morphometric traits (total length, age, weight) were also associated with pansteatitis. On-going research will focus on further evaluating the use of blood chemistry to classify pansteatitis across different species, trophic levels, and within different sites along the Olifants River. PMID:27115488

Suspended sediment load in northwestern South America (Colombia): A new view on variability and fluxes into the Caribbean Sea

NASA Astrophysics Data System (ADS)

Restrepo López, Juan Camilo; Orejarena R, Andrés F.; Torregroza, Ana Carolina

2017-12-01

Monthly averaged suspended sediment load data from seven rivers in northern Colombia (Caribbean alluvial plain) draining into the Caribbean Sea were analyzed to quantify magnitudes, estimate long-term trends, and evaluate variability patterns of suspended sediment load. Collectively these rivers deliver an average of around 146.3 × 106 t yr-1 of suspended sediments to the Colombian Caribbean coast. The largest sediment supply is provided by the Magdalena River, with a mean suspended sediment load of 142.6 × 106 t yr-1, or 38% of the total fluvial discharge estimated for the whole Caribbean littoral zone. Between 2000 and 2010, the annual suspended sediment load of these rivers increased by as much as 36%. Wavelet spectral analyses identified periods of intense variability between 1987-1990 and 1994-2002, where major oscillation processes appeared simultaneously. The semi-annual, annual and quasi-decadal bands are the main factors controlling suspended sediment load variability in fluvial systems, whereas the quasi-biennial and interannual bands constitute second-order sources of variability. The climatic and oceanographic drivers of the oscillations identified through wavelet spectral analyses define a signal of medium-long-term variability for the suspended sediment load, while the physiographic and environmental characteristics of the basins determine their ability to magnify, attenuate or modify this signal.

Seasonal variability of faecal indicator bacteria numbers and die-off rates in the Red River basin, North Viet Nam

NASA Astrophysics Data System (ADS)

Nguyen, Huong Thi Mai; Le, Quynh Thi Phuong; Garnier, J.; Janeau, J.-L.; Rochelle-Newall, E.

2016-02-01

The Red River is the second largest river in Viet Nam and constitutes the main water source for a large percentage of the population of North Viet Nam. Here we present the results of an annual survey of Escherichia coli (EC) and Total Coliforms (TC) in the Red River basin, North Viet Nam. The objective of this work was to obtain information on faecal indicator bacteria (FIB) numbers over an annual cycle and, secondly, to determine the die-off rates of these bacterial indicators. Monthly observations at 10 stations from July 2013-June 2014 showed that TC and EC reached as high as 39100 cfu (colony forming units) 100 ml-1 and 15300 colonies 100 ml-1, respectively. We observed a significant seasonal difference for TC (p < 0.05) with numbers being higher during the wet season. In contrast, no significant seasonal difference was found for EC. The FIB die-off rates ranged from 0.01 d-1 to a maximum of 1.13 d-1 for EC and from 0.17 d-1 to 1.33 d-1 for TC. Die-off rates were significantly higher for free bacteria than for total (free + particle attached) bacteria, suggesting that particle attachment provided a certain level of protection to FIB in this system.

HYDROGRAV - Hydrological model calibration and terrestrial water storage monitoring from GRACE gravimetry and satellite altimetry - First results

NASA Astrophysics Data System (ADS)

Andersen, O. B.; Krogh, P. E.; Michailovsky, C.; Bauer-Gottwein, P.; Christiansen, L.; Berry, P.; Garlick, J.

2008-12-01

Space-borne and ground-based time-lapse gravity observations provide new data for water balance monitoring and hydrological model calibration in the future. The HYDROGRAV project (www.hydrograv.dk) will explore the utility of time-lapse gravity surveys for hydrological model calibration and terrestrial water storage monitoring. Merging remote sensing data from GRACE with other remote sensing data like satellite altimetry and also ground based observations are important to hydrological model calibration and water balance monitoring of large regions and can serve as either supplement or as vital information in un-gauged regions. A system of GRACE custom designed Mass Concentration blocks (Mascons) have been designed to model time-variable gravity changes for the largest basins in Southern Africa (Zambezi, Okavango, Limpopo and Orange) covering an area of 9 mill km2 with a resolution of 1 by 1.25 degree. Satellite altimetry have been used to derive high resolution point-wise river height in some of the un-gauged rivers in the region by using dedicated retracking to recovers nearly un-interrupted time series over these rivers. First result from the HYDROGRAV project analyzing GRACE derived mass change from 2002 to 2008 along with in-situ gravity time-lapse observations and radar altimetry monitoring of surface water for the southern Africa river basins will be presented.

Investigating the sources and sinks of water of Congo's wetlands

NASA Astrophysics Data System (ADS)

Paiva, R. C. D.; O'Loughlin, F.; Alsdorf, D. E.; Durand, M. T.; Beighley, E., II; Calmant, S.; Lee, H.; Santos Da Silva, J.

2014-12-01

The Congo is the second largest river basin in the world and indeed there is still a lot to be investigated about the hydrology of this system. This region presents extensive wetlands that may play an important role on the hydrology, carbon and ecological dynamics of the Congo. However, previous studies indicate that these wetlands behave differently from the Amazon, other major rainforest basin, and how water enters and leaves the Cuvette Centrale wetland is still to be quantified. We investigate the sources and sinks of water to the Congo's wetlands. Our analyses range from simple examinations of precipitation and evaporation historical data to remote sensing datasets and 2 D hydrodynamic modelling of Congo wetlands. Early results show that water levels at wetlands are usually higher than adjacent Congo River water levels and amplitude of variation is considerably smaller. Also, floodplain channels are not observed in this region indicating that surface flows are diffusive. Mean annual precipitation range from 1600 to 2000 mm/year, evapotranspiration estimates are approximately 1100 mm/year while some estimates of groundwater recharge indicate values larger than 300 mm/year. These assessments suggest that volumes coming from local water balance could flood the wetlands to depths of only a few centimeters. Preliminary 2D hydrodynamic simulations show that water coming from main rivers produces at upstream areas can flood only a small part of wetland, mainly alongside these rivers.

Simulated Water-Management Alternatives Using the Modular Modeling System for the Methow River Basin, Washington

USGS Publications Warehouse

Konrad, Christopher P.

2004-01-01

A precipitation-runoff model for the Methow River Basin was used to simulate six alternatives: (1) baseline of current flow, (2) line irrigation canals to limit seepage losses, (3) increase surface-water diversions through unlined canals for aquifer recharge, (4) convert from surface-water to ground-water resources to supply water for irrigation, and (5) reduce tree density in forested headwater catchments, and (6) natural flow. Daily streamflow from October 1, 1959, to September 30, 2001 (water years 1960?2001) was simulated. Lining irrigation canals (alternative 2) increased flows in the Chewuch, Twisp, and the Methow (upstream and at Twisp) Rivers during September because of lower diversion rates, but not in the Methow River near Pateros. Increasing diversions for aquifer recharge (alternative 3) increased streamflow from September into January, but reduced streamflow earlier in the summer. Conversion of surface-water diversions to ground-water wells (alternative 4) resulted in the largest increase in September streamflow of any alternative, but also marginally lower January flows (at most -8 percent in the 90-percent exceedence value). Forest-cover reduction (alternative 5) produced large increases in streamflow during high-flow periods in May and June and earlier onset of high flows and small increases in January streamflows. September streamflows were largely unaffected by alternative 5. Natural streamflow (alternative 6) was higher in September and lower in January than the baseline alternative.

Seasonal variability of faecal indicator bacteria numbers and die-off rates in the Red River basin, North Viet Nam.

PubMed

Nguyen, Huong Thi Mai; Le, Quynh Thi Phuong; Garnier, J; Janeau, J-L; Rochelle-Newall, E

2016-02-12

The Red River is the second largest river in Viet Nam and constitutes the main water source for a large percentage of the population of North Viet Nam. Here we present the results of an annual survey of Escherichia coli (EC) and Total Coliforms (TC) in the Red River basin, North Viet Nam. The objective of this work was to obtain information on faecal indicator bacteria (FIB) numbers over an annual cycle and, secondly, to determine the die-off rates of these bacterial indicators. Monthly observations at 10 stations from July 2013-June 2014 showed that TC and EC reached as high as 39100 cfu (colony forming units) 100 ml(-1) and 15300 colonies 100 ml(-1), respectively. We observed a significant seasonal difference for TC (p < 0.05) with numbers being higher during the wet season. In contrast, no significant seasonal difference was found for EC. The FIB die-off rates ranged from 0.01 d(-1) to a maximum of 1.13 d(-1) for EC and from 0.17 d(-1) to 1.33 d(-1) for TC. Die-off rates were significantly higher for free bacteria than for total (free + particle attached) bacteria, suggesting that particle attachment provided a certain level of protection to FIB in this system.

Channel Width Change as a Potential Sediment Source, Minnesota River Basin

NASA Astrophysics Data System (ADS)

Lauer, J. W.; Echterling, C.; Lenhart, C. F.; Rausch, R.; Belmont, P.

2017-12-01

Turbidity and suspended sediment are important management considerations along the Minnesota River. The system has experience large and relatively consistent increases in both discharge and channel width over the past century. Here we consider the potential role of channel cross section enlargement as a sediment source. Reach-average channel width was digitized from aerial images dated between 1937 and 2015 along multiple sub-reaches of the Minnesota River and its major tributaries. Many of the sub-reaches include several actively migrating bends. The analysis shows relatively consistent increases in width over time, with average increase rates of 0.4 percent per year. Extrapolation to the river network using a regional relationship for cross-sectional area vs. drainage area indicates that large tributaries and main-stem reaches account for most of the bankfull cross-sectional volume in the basin. Larger tributaries and the main stem thus appear more important for widening related sediment production than small tributaries. On a basin-wide basis, widening could be responsible for a gross supply of more sediment than has been gaged at several main-stem sites, indicating that there may be important sinks for both sand and silt/clay size material distributed throughout the system. Sediment storage is probably largest along the lowest-slope reaches of the main stem. While channel width appears to have adjusted relatively quickly in response to discharge and other hydraulic modifications, net storage of sediment in floodplains probably occurs sufficiently slowly that depth adjustment will lag width adjustment significantly. Detailed analysis of the lower Minnesota River using a river segmenting approach allows for a more detailed assessment of reach-scale processes. Away from channel cutoffs, elongation of the channel at eroding bends is consistent with rates observed on other actively migrating rivers. However, the sinuosity increase has been more than compensated by several natural and engineered cutoffs. The sinuosity change away from cutoffs probably plays a relatively modest role in the reach's sediment budget. However, point bars and abandoned oxbow lakes are important zones of sediment storage that may be large enough to account for much of the widening-related production of sand in the reach.

Amsterdam, Netherlands

NASA Image and Video Library

2012-11-26

Amsterdam is the largest city and the capital of the Netherlands. Its name derives from a dam in the river Amstel. Founded in the 12th century as a fishing village, Amsterdam was one of the most important ports in the world in the 17th century.

Water-Quality Assessment of the Yellowstone River Basin, Montana and Wyoming-Water Quality of Fixed Sites, 1999-2001

USGS Publications Warehouse

Miller, Kirk A.; Clark, Melanie L.; Wright, Peter R.

2005-01-01

The National Water-Quality Assessment Program of the U.S. Geological Survey initiated an assessment in 1997 of the quality of water resources in the Yellowstone River Basin. Water-quality samples regularly were collected during 1999-2001 at 10 fixed sites on streams representing the major environmental settings of the basin. Integrator sites, which are heterogeneous in land use and geology, were established on the mainstem of the Yellowstone River (4 sites) and on three major tributaries?Clarks Fork Yellowstone River (1 site), the Bighorn River (1 site), and the Powder River (1 site). Indicator sites, which are more homogeneous in land use and geology than the integrator sites, were located on minor tributaries with important environmental settings?Soda Butte Creek in a mineral resource area (1 site), the Tongue River in a forested area (1 site), and the Little Powder River in a rangeland area (1 site). Water-quality sampling frequency generally was at least monthly and included field measurements and laboratory analyses of fecal-indicator bacteria, major ions, dissolved solids, nutrients, trace elements, pesticides, and suspended sediment. Median concentrations of fecal coliform and Escherichia coli were largest for basins that were predominantly rangeland and smallest for basins that were predominantly forested. Concentrations of fecal coliform and Escherichia coli significantly varied by season (p-value <0.001); the smallest median concentrations were during January?March and the largest median concentrations were during April?June. Fecal-coliform concentrations exceeded the U.S. Environmental Protection Agency recommended limit for a single sample of 400 colonies per 100 milliliters in 2.6 percent of all samples. Escherichia coli concentrations exceeded the U.S. Environmental Protection Agency recommended limit for a single sample of 298 colonies per 100 milliliters for moderate use, full-body contact recreation in 7.6 percent of all samples. Variations in water type in the basin are reflective of the diverse geologic terrain in the Yellowstone River Basin. The water type of Soda Butte Creek and the Tongue River was calcium bicarbonate. These two sites are in forested and mountainous areas where igneous rocks and Paleozoic-era and Mesozoic-era sedimentary rocks are the dominant geologic groups. The water type of the Little Powder River was sodium sulfate. The Little Powder River originates in the plains, and geology of the basin is nearly homogenous with Tertiary-period sedimentary rocks. Water type of the Yellowstone River changed from a mixed-cation bicarbonate type upstream to a mixed-cation sulfate type downstream. Dissolved-solids concentrations ranged from fairly dilute in Soda Butte Creek, which had a median concentration of 118 milligrams per liter, to concentrated in the Little Powder River, which had a median concentration of 2,840 milligrams per liter. Nutrient concentrations generally were small and reflect the relatively undeveloped conditions in the basin; however, some correlations were made with anthropogenic factors. Median dissolved-nitrate concentrations in all samples from the fixed sites ranged from 0.04 milligram per liter to 0.54 milligram per liter. Flow-weighted mean dissolved-nitrate concentrations were positively correlated with increasing agricultural land use and rangeland on alluvial deposits upstream from the sites and negatively correlated with increasing forested land. Ammonia concentrations generally were largest in samples collected from the Yellowstone River at Corwin Springs, Montana, which is downstream from Yellowstone National Park and receives discharge from geothermal waters that are high in ammonia. Median total-phosphorus concentrations ranged from 0.007 to 0.18 milligram per liter. Median total-phosphorus concentrations exceeded the U.S. Environmental Protection Agency's recommended goal of 0.10 milligram per liter for preventing nuisance plant growth for samples collec

Occurrence of polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls pollution in sediments from the Haihe River and Dagu Drainage River in Tianjin City, China.

PubMed

Liu, Hanxia; Zhang, Qinghua; Wang, Yawei; Cai, Zongwei; Jiang, Guibin

2007-08-01

The pollution status of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in the sediments of Haihe River, which is the most polluted among the seven largest basins in China, Dagu Drainage River flowing through a chemical industry zone, and two other rivers flowing into Bohai Sea in Tianjin City, China were investigated. The concentrations of PCDD/Fs and PCBs in the sediments from the mainstream of Haihe River were 1.3-26pgI-TEQg(-1) dry weight (dw) and 0.07-0.54pgTEQg(-1)dw, respectively. Heavy PCDD/Fs and PCBs pollution, with 1264pgI-TEQg(-1)dw and 21pgTEQg(-1)dw, was found in sediment from Dagu Drainage River. The congener profiles of PCDD/Fs indicated that the principal contamination source was the production of pentachlorophenol (PCP) or PCP-Na in this area. The correlation between PCDD/Fs or PCBs and total organic matter (TOM) showed that PCDD/Fs or PCBs were independent on TOM.

Lateral carbon export in the Mississippi River Basin, integrating fluxes from the headwaters to the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Stackpoole, S. M.; Crawford, J.; Santi, L. M.; Stets, E.; Sebestyen, S. D.; Wilson, S.; Striegl, R. G.

2017-12-01

Large-scale river studies have documented that lateral fluxes are an important component of the global carbon cycle. This study focuses on river lateral C fluxes for the Mississippi River Basin (MRB), the largest river in North America. Our lateral river C fluxes are based on data from 23 nested watersheds within the Upper MRB, for water years 2015 and 2016. The study area covers 170,000 km2 and is comprised of both catchment <10 km2 and intermediate-scale watersheds (20,000 to 40,000 km2) in Wisconsin and Minnesota, USA. Total alkalinity yields (flux derived by drainage area) ranged from 0 to 16 g C m2 yr-1 and dissolved organic C (DOC) yields ranged from 1 to 13 g C m2 yr-1. In comparison, published estimates for Mississippi River export to the Gulf of Mexico, estimated at St. Francisville, LA, were 16 g C m-2 yr-1 for alkalinity and 0.6 g m2 yr-1 for DOC. In the Upper MRB, alkalinity yields had a significant negative relationship with DOC yields (R2 = 0.53, p-value<0.0001), and alkalinity yields were significantly higher in basins where the lithology was dominated by carbonates and the land-use was >50% agriculture. There was significant inter-annual variability in the total C fluxes, and the increase in discharge in 2016 relative to 2015 increased the proportion of DOC:alkalinity for watersheds with higher forest and wetland coverage. The integration of these recent C flux estimates for the Upper MRB integrated with the fluxes estimated from the USGS long-term monitoring program dataset provide a comprehensive analysis of alkalinity and DOC fluxes for the entire basin. These results, which represent C fluxes across a gradient of lithology, soil type, and land use, will be used to address questions related to our understanding of carbon sources, transport, and loss that can be applied to other river systems.

What Controls the Hydrodynamics of the Central Congo River?

NASA Astrophysics Data System (ADS)

O'Loughlin, F.; Bates, P. D.

2014-12-01

Despite being the second largest river basin in the world, with a drainage area greater than 3.7 million square kilometres, little is known about the hydraulics of the Congo River. This lack of knowledge is mainly due to a mixture of conflicts and the difficulty of accessing existing data. We present results of studies which have focused primarily on the middle reach of the Congo River, located between Kisangani and Kinshasa, and its six main tributaries (Kasai, Ubangai, Sangha, Ruki, Lulonga and Lomami rivers). Through a combination of remotely sensed datasets and a hydrodynamic model we investigated what factors control the hydrodynamics of the middle reach. From the analysis of the remotely sensed datasets, we discover that variability in river width of the middle reach of the Congo is large and cannot be represented by empirical equations which relate channel geometry to basin area and discharge. Water surface slopes vary from 3.5 cm/km to 9 cm/km, which is far more than previous studies suggest. The remote datasets indicate that there exist 5 large constrictions in the river width which may result in backwater affecting between 11 and 33 percent of middle reach at low and high water respectively. These results were corroborated by the hydrodynamic model. In fact, when all constrictions caused by a narrowing in width of 1 km or more are considered, water levels along 43 percent of the middle reach change by at least 0.5 m. Using the hydrodynamic model we also investigated the importance of the wetlands to the attenuation of the flood wave through the system. Initial results suggest that for the Congo River, floodplains have far more impact on the peak magnitude than the timing of the flood wave. When the model was run with no floodplain interactions an increase in the magnitude of flood peak was observed, with the timing of the waves being consistent with observed measurements.

Morpho-dynamics of the Brahmaputra-Jamuna River, Bangladesh

NASA Astrophysics Data System (ADS)

Sarker, Maminul H.; Thorne, Colin R.; Aktar, M. Nazneen; Ferdous, Md. Ruknul

2014-06-01

The Jamuna River is the downstream continuation of the Brahmaputra in Bangladesh. It is one of the largest sand-bed braided rivers in the world and every year it erodes thousand hectares of mainland floodplain, rendering tens of thousands of people landless and/or homeless. Understanding the morpho-dynamics of this river and its responses to the various drivers of morphological change that act on it is essential to improving the livelihoods of millions of floodplain dwellers in Bangladesh, especially given the threats posed by climate change. Reliable data, information and knowledge of river process are sparse and so progress in linking the impacts of multiple drivers (including neo-tectonics, earthquakes, large-scale avulsions and engineering interventions) to complex morphological responses depends on making best use of historical maps, time-series satellite images, hydro-morphological data, expert judgment and local knowledge. This paper draws on all these sources to chronicle the morphological evolution of the Jamuna River since the avulsion that created it about 200 years ago, and to establish temporal trends and spatial patterns in the changes that have characterized process-response mechanisms in this fluvial system since then. The understanding gained from these investigations then supports deeper analyses to: explain how historical migration of the river westward has produced significant contrasts between left and right (west) bank material properties; elucidate the relationships between discharge, fluvial processes, anabranch instability and floodplain erosion rates, and; identify causal links between drivers and morphological responses at a variety of time and space scales. Finally, the new knowledge generated by the analyses developed herein are combined with existing, conceptual and empirical process-response models for the Jamuna to predict possible future morphological adjustments in ways helpful in identifying appropriate strategies for climate change adaptation in Bangladesh. The enhanced knowledge gained from these historical and contemporary investigations may also be useful in assessing the impacts of natural and anthropogenic drivers on other large, braided rivers.

The Paradox of Restoring Native River Landscapes and Restoring Native Ecosystems in the Colorado River System

NASA Astrophysics Data System (ADS)

Schmidt, J. C.

2014-12-01

Throughout the Colorado River basin (CRb), scientists and river managers collaborate to improve native ecosystems. Native ecosystems have deteriorated due to construction of dams and diversions that alter natural flow, sediment supply, and temperature regimes, trans-basin diversions that extract large amounts of water from some segments of the channel network, and invasion of non-native animals and plants. These scientist/manager collaborations occur in large, multi-stakeholder, adaptive management programs that include the Lower Colorado River Multi-Species Conservation Program, the Glen Canyon Dam Adaptive Management Program, and the Upper Colorado River Endangered Species Recovery Program. Although a fundamental premise of native species recovery is that restoration of predam flow regimes inevitably leads to native species recovery, such is not the case in many parts of the CRb. For example, populations of the endangered humpback chub (Gila cypha) are largest in the sediment deficit, thermally altered conditions of the Colorado River downstream from Glen Canyon Dam, but these species occur in much smaller numbers in the upper CRb even though the flow regime, sediment supply, and sediment mass balance are less perturbed. Similar contrasts in the physical and biological response of restoration of predam flow regimes occurs in floodplains dominated by nonnative tamarisk (Tamarix spp.) where reestablishment of floods has the potential to exacerbate vertical accretion processes that disconnect the floodplain from the modern flow regime. A significant challenge in restoring segments of the CRb is to describe this paradox of physical and biological response to reestablishment of pre-dam flow regimes, and to clearly identify objectives of environmentally oriented river management. In many cases, understanding the nature of the perturbation to sediment mass balance caused by dams and diversions and understanding the constraints imposed by societal commitments to provide assured water supplies and hydroelectricity constrains the opportunities for rehabilitation and limits the management objectives to focus either on restoring predam physical processes or recovering native fish fauna and/or recovering native plant communities.

A century of hydrological variability and trends in the Fraser River Basin

NASA Astrophysics Data System (ADS)

Déry, Stephen J.; Hernández-Henríquez, Marco A.; Owens, Philip N.; Parkes, Margot W.; Petticrew, Ellen L.

2012-06-01

This study examines the 1911-2010 variability and trends in annual streamflow at 139 sites across the Fraser River Basin (FRB) of British Columbia (BC), Canada. The Fraser River is the largest Canadian waterway flowing to the Pacific Ocean and is one of the world’s greatest salmon rivers. Our analyses reveal high runoff rates and low interannual variability in alpine and coastal rivers, and low runoff rates and high interannual variability in most streams in BC’s interior. The interannual variability in streamflow is also low in rivers such as the Adams, Chilko, Quesnel and Stuart where the principal salmon runs of the Fraser River occur. A trend analysis shows a spatially coherent signal with increasing interannual variability in streamflow across the FRB in recent decades, most notably in spring and summer. The upward trend in the coefficient of variation in annual runoff coincides with a period of near-normal annual runoff for the Fraser River at Hope. The interannual variability in streamflow is greater in regulated rather than natural systems; however, it is unclear whether it is predominantly flow regulation that leads to these observed differences. Environmental changes such as rising air temperatures, more frequent polarity changes in large-scale climate teleconnections such as El Niño-Southern Oscillation and Pacific Decadal Oscillation, and retreating glaciers may be contributing to the greater range in annual runoff fluctuations across the FRB. This has implications for ecological processes throughout the basin, for example affecting migrating and spawning salmon, a keystone species vital to First Nations communities as well as to commercial and recreational fisheries. To exemplify this linkage between variable flows and biological responses, the unusual FRB runoff anomalies observed in 2010 are discussed in the context of that year’s sockeye salmon run. As the climate continues to warm, greater variability in annual streamflow, and hence in hydrological extremes, may influence ecological processes and human usage throughout the FRB in the 21st century.

Variations of Connecticut River Water Pathways and Its Water Age: A Coupled Modeling Study

NASA Astrophysics Data System (ADS)

Jia, Y.; Whitney, M. M.

2016-02-01

As the largest freshwater source to the east-west oriented Long Island Sound (LIS), the Connecticut River (CR) delivers water on the north shore near the sound's mouth. The pathways the river water follows through LIS are impacted by river discharge, tides, winds, and complex topography. Using the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System, with passive dyes and age tracers, the main routes of CR water through the estuary and onto the shelf are determined with their corresponding time scales. During a high discharge period, the CR plume occupies the northern half of eastern LIS and extends farther west than during average discharge conditions. Most of the river water inside the central LIS is transported through this surface plume. After being mixed to deeper depths and farther offshore, the river water that is still within LIS is transported westward. During periods of low discharge, freshwater is initially more prevalent between the CR and the LIS mouth. Later, CR water mixed to depths still moves westward, reaching the estuary's head in approximately 3 weeks. Neap tide allows more CR water to quickly escape to the open shelf through Block Island Sound (BIS) while spring tide allows more CR water back into the central LIS at depth. BIS has a uniform water age ranging from 40 to 50 days throughout the water column. Lower discharge leads to older age in BIS. In western LIS, CR water age at depth increases from 50 to 75 days as discharge decreases and is several days younger than water closer to the surface. These results suggest a bottom-in/surface-out transport pattern exists for CR water in LIS for at least part of the year.

The Central Role of the Mississippi River and its Delta in the Oceanography, Ecology and Economy of the Gulf of Mexico: A Synthesis

NASA Astrophysics Data System (ADS)

Kolker, A.; Chu, P. Y.; Taylor, C.; Roberts, B. J.; Renfro, A. A.; Peyronnin, N.; Fitzpatrick, C.

2017-12-01

While it has long been recognized that the Mississippi River is the largest source of freshwater, nutrients and sediments to the Gulf of Mexico, many questions remain unanswered about the impacts of the material on oceanography of the system. Here we report on the results of a regional synthesis study that examined how the Mississippi River and its delta influence the oceanography, ecology and the economy of the Gulf of Mexico. By employing a series of expert-opinion working groups, and using multi-dimensional numerical physical oceanographic models coupled to in-situ environmental data, this project is working to quantify how variability in discharge, meteorological forcings, and seasonal conditions influence the spatial distribution of the Mississippi River plume and its influence. Results collected to date indicate that the dimensions of the river plume are closely coupled to discharge, but in a non-linear fashion, that incorporates fluxes, flow distributions, offshore and meteorological forcings in the context of the local bathymetry. Ongoing research is using these human and numerical tools to help further elucidate the impacts of this river on the biogeochemistry of the region, and the distribution of key macrofauna. Further work by this team is examining how the delta's impacts on the ecology of the region, and the role that the delta plays as both a source of material for key offshore fauna, and a barrier to dispersal. This information is being used to help further the development of a research agenda for the northern Gulf of Mexico that will be useful through the mid-21st century.

Geospatial Investigation into Groundwater Pollution and Water Quality Supported by Satellite Data: A Case Study from the Evros River (Eastern Mediterranean)

NASA Astrophysics Data System (ADS)

Elias, Dimitriou; Angeliki, Mentzafou; Vasiliki, Markogianni; Maria, Tzortziou; Christina, Zeri

2014-06-01

Managing water resources, in terms of both quality and quantity, in transboundary rivers is a difficult and challenging task that requires efficient cross-border cooperation and transparency. Groundwater pollution risk assessment and mapping techniques over the full catchment area are important tools that could be used as part of these water resource management efforts, to estimate pollution pressures and optimize land planning processes. The Evros river catchment is the second largest river in Eastern Europe and sustains a population of 3.6 million people in three different countries (Bulgaria, Turkey and Greece). This study provides detailed information on the main pollution sources and pressures in the Evros catchment and, for the first time, applies, assesses and evaluates a groundwater pollution risk mapping technique using satellite observations (Landsat NDVI) and an extensive dataset of field measurements covering different seasons and multiple years. We found that approximately 40 % of the Greek part of the Evros catchment is characterized as of high and very high pollution risk, while 14 % of the study area is classified as of moderate risk. Both the modeled and measured water quality status of the river showed large spatiotemporal variations consistent with the strong anthropogenic pressures in this system, especially on the northern and central segments of the catchment. The pollutants identified illustrate inputs of agrochemicals and urban wastes in the river. High correlation coefficients ( R between 0.79 and 0.85) were found between estimated pollution risks and measured concentrations of those chemical parameters that are mainly attributed to anthropogenic activities rather than in situ biogeochemical processes. The pollution risk method described here could be used elsewhere as a decision support tool for mitigating the impact of hazardous human activities and improving management of groundwater resources.

Nature of distribution of mercury in the sediments of the river Yamuna (tributary of the Ganges), India.

PubMed

Subramanian, V; Madhavan, N; Saxena, Rajinder; Lundin, Lars-Christer

2003-06-01

Suspended Particulate Matter (SPM), surface (bed sediments) and short length cores of sediments collected from the largest tributary of the river Ganges, namely the river Yamuna, were analysed for total mercury as well as its fractionation in various size and chemical sites in the sediments following standard procedures. Also, attempts were made to determine the vertical distribution in sediments in relation to the recent timescale of a few decades. Our observations indicate that the SPM in general showed higher levels of total mercury compared to the surface sediments while at places the enhancement could be by a factor of 10, say around 25 microg g(-1) in the downstream region that integrates the industrial midstream and agricultural downstream terrain near its confluence with the Ganges. Surface sediments in the upstream direction near the Himalayan foothills and SPM in the lower reaches showed significant high Index of Geoaccumulation (Igeo) as defined by Müller. Size fractionation studies indicate that the finer fraction preferentially showed higher levels of mercury while in the lower reaches of the river, the total mercury is equitably distributed among all size fractions. The proportion of the residual fraction of mercury in relation to mobile fractions, in general decreases downstream towards its confluence with the Ganges river. In sediment cores, the vertical distribution show systematic peaks of mercury indicating that addition of this toxic metal to the aquatic system is in direct proportion to the increase in various types of human activities such as thermal power plants, land use changes (urbanisation) in the midstream region and intensive fertiliser application in lower reaches of this vast river basin.

Nutrients discharged to the Mississippi River from eastern Iowa watersheds, 1996-1997

USGS Publications Warehouse

Becher, Kent D.; Schnoebelen, Douglas J.; Akers, Kimberlee K.

2000-01-01

The introduction of nutrients from chemical fertilizer, animal manure, wastewater, and atmospheric deposition to the eastern Iowa environment creates a large potential for nutrient transport in watersheds. Agriculture constitutes 93 percent of all land use in eastern Iowa. As part of the U.S. Geological Survey National Water Quality Assessment Program, water samples were collected (typically monthly) from six small and six large watersheds in eastern Iowa between March 1996 and September 1997. A Geographic Information System (GIS) was used to determine land use and quantify inputs of nitrogen and phosphorus within the study area. Streamliow from the watersheds is to the Mississippi River. Chemical fertilizer and animal manure account for 92 percent of the estimated total nitrogen and 99.9 percent of the estimated total phosphorus input in the study area. Total nitrogen and total phosphorus loads for 1996 were estimated for nine of the 12 rivers and creeks using a minimum variance unbiased estimator model. A seasonal pattern of concentrations and loads was observed. The greatest concentrations and loads occur in the late spring to early summer in conjunction with row-crop fertilizer applications and spring nmoff and again in the late fall to early winter as vegetation goes into dormancy and additional fertilizer is applied to row-crop fields. The three largest rivers in eastern Iowa transported an estimated total of 79,000 metric tons of total nitrogen and 6,800 metric tons of total phosphorus to the Mississippi River in 1996. The estimated mass of total nitrogen and total phosphorus transported to the Mississippi River represents about 19 percent of all estimated nitrogen and 9 percent of all estimated phosphorus input to the study area.

The July 11, 1995 Myanmar-China earthquake: A representative event in the bookshelf faulting system of southeastern Asia observed from JERS-1 SAR images

NASA Astrophysics Data System (ADS)

Ji, Lingyun; Wang, Qingliang; Xu, Jing; Ji, Cunwei

2017-03-01

On July 11, 1995, an Mw 6.8 earthquake struck eastern Myanmar near the Chinese border; hereafter referred to as the 1995 Myanmar-China earthquake. Coseismic surface displacements associated with this event are identified from JERS-1 (Japanese Earth Resources Satellite-1) SAR (Synthetic Aperture Radar) images. The largest relative displacement reached 60 cm in the line-of-sight direction. We speculate that a previously unrecognized dextral strike-slip subvertical fault striking NW-SE was responsible for this event. The coseismic slip distribution on the fault planes is inverted based on the InSAR-derived deformation. The results indicate that the fault slip was confined to two lobes. The maximum slip reached approximately 2.5 m at a depth of 5 km in the northwestern part of the focal region. The inverted geodetic moment was approximately Mw = 6.69, which is consistent with seismological results. The 1995 Myanmar-China earthquake is one of the largest recorded earthquakes that has occurred around the "bookshelf faulting" system between the Sagaing fault in Myanmar and the Red River fault in southwestern China.

A field study of the confluence between Negro and Solimões Rivers. Part 1: Hydrodynamics and sediment transport

NASA Astrophysics Data System (ADS)

Gualtieri, Carlo; Filizola, Naziano; de Oliveira, Marco; Santos, Andrè Martinelli; Ianniruberto, Marco

2018-01-01

Confluences are a common feature of riverine systems, where are located converging flow streamlines and potential mixing of separate flows. The confluence of the Negro and Solimões Rivers ranks among the largest on Earth and its study may provide some general insights into large confluence dynamics and processes. An investigation was recently conducted about that confluence in both low and high-flow conditions using acoustic Doppler velocity profiling (ADCP), water quality sampling and high-resolution seismic data. First, the study gained insights into the characterization of the basic hydrodynamics parameters about the confluence as well as of those affecting sediments transport. Second, the analysis of the results showed that common hydrodynamic features noted in previous confluence studies were herein observed. Finally, some differences between low-flow and relatively high-flow conditions about the transfer of momentum from the Solimões to the Negro side of the Amazon Channel were identified.

Status and distribution of the West Indian manatee, Trichechus manatus manatus, in Colombia

USGS Publications Warehouse

Montoya-Ospina, R. A.; Caicedo-Herrera, D.; Millan-Sanchez, S. L.; Mignucci-Giannoni, A. A.; Lefebvre, L.W.

2001-01-01

Historical and recent information on the status and distribution of West Indian manatee, Trichechus manatus manatus, in Colombia was reviewed. Opportunistic and systematic interviews were also conducted. Historical information suggested that the distribution of manatees had been reduced in the Caribbean basin. Manatees can be found in the Atrato, Sinu??, San Jorge, Cauca, Cesar and Magdalena rivers and the Cie??naga Grande de Santa Marta marsh in the Caribbean basin, and in the Meta River in the Orinoco basin. The Magdalena riparian system provides the largest area of suitable habitat, which also has the highest frequency of captures. Most animals (81.20%) were killed for sale or to share meat in a subsistence base. Hunting is apparently increasing but capture with nets still represents the species' major direct threat. Habitat destruction occurs in all areas. International and national laws protect the species, however, funding is inadequate for effective enforcement of present laws. ?? 2001 Published by Elsevier Science Ltd. All rights reserved.

Earth Observations taken by the Expedition 10 crew

NASA Image and Video Library

2004-10-25

ISS010-E-05070 (25 October 2004) --- Corrientes, Argentina, and the Parana River are featured in this image photographed by an Expedition 10 crewmember on the International Space Station (ISS). Corrientes, Argentina sits on the east bank of the Parana River, South America’s third largest river (after the Negro and Amazon Rivers). From its headwaters in southeastern Brazil, the river flows southwestward around southern Paraguay, and then into Argentina. Corrientes is located just inside Argentina, across the river from the southwestern tip of Paraguay. The bridge over the Parana, built in the 1970s, connects Corrientes to its sister city, Resistencia, (beyond the left edge of image) on the western bank of the river. Sun glint on the river gives it a silvery glow and emphasizes channel islands in the river, side channels, and meander scars on the floodplain opposite the city, and even reveals the pattern of disturbed flow downstream of the bridge pylons. The old part of the city appears as a zone of smaller, more densely clustered city blocks along the river to the north of a major highway, which runs through Corrientes from the General Belgrano Bridge to the northeast (upper right of image). Larger blocks of the younger cityscape, with more green space, surround these core neighborhoods.

Status of White Sturgeon (Acipenser transmontanus Richardson, 1863) throughout the species range, threats to survival, and prognosis for the future

USGS Publications Warehouse

Hildebrand, L. R.; Drauch Schreier, Andrea; Lepla, K.; McAdam, S. O.; McLellan, J; Parsley, Michael J.; Paragamian, V L; Young, S P

2016-01-01

White Sturgeon, Acipenser transmontanus (WS), are distributed throughout three major river basins on the West Coast of North America: the Sacramento-San Joaquin, Columbia, and Fraser River drainages. Considered the largest North American freshwater fish, some WS use estuarine habitat and make limited marine movements between river basins. Some populations are listed by the United States or Canada as threatened or endangered (upper Columbia River above Grand Coulee Dam; Kootenai River; lower, middle and, upper Fraser River and Nechako River), while others do not warrant federal listing at this time (Sacramento-San Joaquin Rivers; Columbia River below Grand Coulee Dam; Snake River). Threats that impact WS throughout the species’ range include fishing effects and habitat alteration and degradation. Several populations suffer from recruitment limitations or collapse due to high early life mortality associated with these threats. Efforts to preserve WS populations include annual monitoring, harvest restrictions, habitat restoration, and conservation aquaculture. This paper provides a review of current knowledge on WS life history, ecology, physiology, behavior, and genetics and presents the status of WS in each drainage. Ongoing management and conservation efforts and additional research needs are identified to address present and future risks to the species.

A mass-wasting dominated Quaternary mountain range, the Coastal Range in eastern Taiwan

NASA Astrophysics Data System (ADS)

Hsieh, Meng-Long; Hogg, Alan; Song, Sheng-Rong; Kang, Su-Chen; Chou, Chun-Yen

2017-12-01

Fluvial bedrock incision, which creates topographic relief and controls hillslope development, has been considered the key medium linking denudation and tectonic uplift of unglaciated mountains. This article, however, shows a different scenario from the Coastal Range in eastern Taiwan. This range, with the steepness inherited from pre-orogenic volcanoes, has been subject to mass wasting even before its emergence above sea level no earlier than Middle Pleistocene. Numerous terraced alluvial fans/fan deltas record the ancient mass movements of the range, including rock avalanches. Multiple radiocarbon dates <16 ka cal BP reveal the recurrence intervals of these movements of over several thousand years. The largest event is dated ∼15 ka cal BP, and the two second largest, 9-8 ka cal BP. These mass movements were sourced from ridges with minimum heights of 350-400 m, have sequences not clearly related to the known climate-change events, and are believed to have been triggered mainly by severe rainfall events, large earthquakes, or their combinations. The resulting fluctuation of sediment yield has episodically changed river behavior, forming river terraces in catchments >1 km2. Alluvial terraces are typically exhibited close to the source ridges of mass movements, and strath terraces along the downstream parts of rivers. Both were created when enormous sediment supply had exceeded or matched the prevailing river transport capacity. This process, along with the protection by giant boulders from mass movement, disturbed the long-term incision trend of rivers in response to tectonic uplift. As a result, the observed Holocene bedrock incision at most sites has not kept pace with the tectonic uplift. The spatial contrast in mass-wasting histories further accounts for the great diversity of the terrace sequences, even in areas with similar tectonic and base-level conditions.

Quantity and quality of phosphorus losses from an artificially drained lowland catchment

NASA Astrophysics Data System (ADS)

Nausch, Monika; Woelk, Jana; Kahle, Petra; Nausch, Günther; Leipe, Thomas; Lennartz, Bernd

2017-04-01

Currently, agricultural diffuse sources constitute the major portion of phosphorus (P) fluxes to the Baltic Sea and have to reach the good ecological status aimed by the Baltic Sea Action Plan and the Marine Strategy Framework Directive. The objective of this study was to uncover the change in phosphorus loading as well as in P fractions along the flow path of a mid-size river basin in order to derive risk assessment and management strategies for a sustainable P reduction. P-fractions and the mineral composition of particulate P were investigated in a sub-basin of the river Warnow, the second largest German catchment discharging to the Baltic Sea. Samples were collected from the sources (tile drain, ditch) and along the subsequent brook up to the river Warnow representing spatial scales of a few hectars up to 3300 km2. The investigations were performed during the discharge season from November 1th 2013 until April 30th 2014 covering a relative dry and mild winter period. We observed an increase of total phosphorus (TP) concentrations from 15.5 ± 3.9 µg L-1 in the drain outlet to 72.0 ± 7.2 µg L-1 in the river Warnow emphasizing the importance of sediment-bound P mobilization along the flow path. Particulate phosphorus (PP) of 36.6 - 61.2% accounted for the largest share of TP in the streams. Clay minerals and Fe(hydr)oxides were the main carrier of particle bound P followed by apatite. A transformation of dissolved inorganic phosphorus (DIP) into particulate organic P was observed in the river Warnow with the beginning of the growth season in February. Our investigations indicate that the overall P load could be reduced by half when PP is removed.

Top-down and bottom-up interactions influence fledging success at North America’s largest colony of Caspian terns (Hydroprogne caspia)

USGS Publications Warehouse

Collar, Stefanie; Roby, Daniel D.; Lyons, Donald E.

2017-01-01

Our study investigated the influence of bottom-up and top-down drivers on the declining fledging success at a once thriving breeding colony of Caspian terns (Hydroprogne caspia). Situated at the mouth of the Columbia River, OR, East Sand Island (ESI) is home to the largest Caspian tern breeding colony in North America. Since 2001, the decline in fledging success of Caspian terns at ESI has been associated with a significant increase in average river discharge during May and June. During the years 2001–2011, the abundance of forage fish available to terns in the estuary was inversely related to river discharge. This relationship also apparently affected the reliance of nest predators on the tern colony as a food source, resulting in increased disturbance and decreased fledging success at the tern colony in years of higher river discharge. There was a significant longitudinal increase in disturbance rates by bald eagles (Haliaeetus leucocephalus) during June for terns nesting at the ESI colony, and eagle disturbance rates were positively associated with May river discharge. We also found a significant increase in kleptoparasitism rates of terns by hybrid glaucous-winged/western gulls (Larus glaucescens x Larus occidentalis) since 2001, and Caspian tern fledging success at ESI decreased with increasing average annual rates of gull kleptoparasitism. Our results support the hypothesis that the decline in Caspian tern fledging success at this large estuarine colony was primarily driven by the interaction of bottom-up and top-down factors, influencing tern fledging success through the food supply and triggering potential predators to identify the tern breeding colony as an alternative source of prey.

Character and Significance of Surface Rupture Near the Intersection of the Denali and Totschunda Faults, M7.9 Denali Fault Earthquake, Alaska, November 3, 2002

NASA Astrophysics Data System (ADS)

Wallace, W. K.; Sherrod, B. L.; Dawson, T. E.

2002-12-01

Preliminary observations suggest that right-lateral strike-slip on the Denali fault is transferred to the Totschunda fault via an extensional bend in the Little Tok River valley. Most of the surface rupture during the Denali fault earthquake was along an east- to east-southeast striking, gently curved segment of the Denali fault. However, in the Little Tok River valley, rupture transferred to the southeast-striking Totschunda fault and continued to the southeast for another 75 km. West of the Little Tok River valley, 5-7 m of right-lateral slip and up to 2 m of vertical offset occurred on the main strand of the Denali fault, but no apparent displacement occurred on the Denali fault east of the valley. Rupture west of the intersection also occurred on multiple discontinuous strands parallel to and south of the main strand of the Denali fault. In the Little Tok River valley, the northern part of the Totschunda fault system consists of multiple discontinuous southeast-striking strands that are connected locally by south-striking stepover faults. Faults of the northern Totschunda system display 0-2.5 m of right-lateral slip and 0-2.75 m of vertical offset, with the largest vertical offset on a dominantly extensional stepover fault. The strands of the Totschunda system converge southeastward to a single strand that had up to 2 m of slip. Complex and discontinuous faulting may reflect in part the immaturity of the northern Totschunda system, which is known to be younger and have much less total slip than the Denali. The Totschunda fault forms an extensional bend relative to the dominantly right-lateral Denali fault to the west. The fault geometry and displacements at the intersection suggest that slip on the Denali fault during the earthquake was accommodated largely by extension in the northern Totschunda fault system, allowing a significant decrease in strike-slip relative to the Denali fault. Strands to the southwest in the area of the bend may represent shortcut faults that have reduced the curvature at the intersection of the two fault systems.

Geochemical Controls on the Partitioning and Hydrological Transport of Metals in a Human Impacted, Non-Acidic, River System

NASA Astrophysics Data System (ADS)

Thorslund, J.; Jarsjo, J.; Wällstedt, T.; Morth, C. M.; Lychagin, M.; Chalov, S.

2014-12-01

The knowledge of coupled processes controlling the spreading and fate of metals in non-acidic river systems is currently much more limited than the knowledge of metal behavior under acidic conditions (e.g., in acid mine drainage systems). Critical geochemical controls governing metal speciation may thus differ substantially between acidic and non-acidic hydrological systems. We here aim at expanding the knowledge of metals in non-acidic river systems, by considering a high pH river, influenced by mining by the largest gold mining area in the Mongolian part of the transboundary Lake Baikal drainage basin. The combined impact of geochemical and hydrological processes is investigated, to be able to understand the solubility of various heavy metals, their partitioning between particulate and dissolved phase and its impact on overall transport. We show, through site specific measurements and a geochemical modelling approach, that the combined effects of precipitation of ferrihydrite and gibbsite and associated sorption complexes of several metals can explain the high impact of suspended transport relative to total transport often seen under non-acidic conditions. Our results also identifies the phosphate mineral Hydroxyapatite as a potential key sorption site for many metals, which has both site specific and general relevance for metal partitioning under non-acidic conditions. However, an adsorption database, which is currently unavailable for hydroxyapatite, needs to be developed for appropriate sorption quantification. Furthermore, Cd, Fe, Pb and Zn were particularly sensitive to increasing DOC concentrations, which increased the solubility of these metals due to metal-organic complexation. Modeling the sensitivity to changes in geochemical parameters showed that decreasing pH and increasing DOC concentrations in downstream regions would increase the dissolution and hence the toxicity and bioavailability of many pollutants of concern in the downstream ecosystem. In general, this study suggests that in non-acidic hydrological systems, both seasonality of DOC concentrations (which could vary by several 100%), changing DOC concentrations (resulting from climate and land use changes) and potential phosphate solids can majorly influence on the spreading and toxicity of several metals.

Denitrification across landscapes and waterscapes: A synthesis

USGS Publications Warehouse

Seitzinger, S.; Harrison, J.A.; Böhlke, J.K.; Bouwman, A.F.; Lowrance, R.; Peterson, B.; Tobias, C.; Van Drecht, G.

2006-01-01

Denitrification is a critical process regulating the removal of bioavailable nitrogen (N) from natural and human-altered systems. While it has been extensively studied in terrestrial, freshwater, and marine systems, there has been limited communication among denitrification scientists working in these individual systems. Here, we compare rates of denitrification and controlling factors across a range of ecosystem types. We suggest that terrestrial, freshwater, and marine systems in which denitrification occurs can be organized along a continuum ranging from (1) those in which nitrification and denitrification are tightly coupled in space and time to (2) those in which nitrate production and denitrification are relatively decoupled.In aquatic ecosystems, N inputs influence denitrification rates whereas hydrology and geomorphology influence the proportion of N inputs that are denitrified. Relationships between denitrification and water residence time and N load are remarkably similar across lakes, river reaches, estuaries, and continental shelves.Spatially distributed global models of denitrification suggest that continental shelf sediments account for the largest portion (44%) of total global denitrification, followed by terrestrial soils (22%) and oceanic oxygen minimum zones (OMZs; 14%). Freshwater systems (groundwater, lakes, rivers) account for about 20% and estuaries 1% of total global denitrification. Denitrification of land-based N sources is distributed somewhat differently. Within watersheds, the amount of land-based N denitrified is generally highest in terrestrial soils, with progressively smaller amounts denitrified in groundwater, rivers, lakes and reservoirs, and estuaries. A number of regional exceptions to this general trend of decreasing denitrification in a downstream direction exist, including significant denitrification in continental shelves of N from terrestrial sources. Though terrestrial soils and groundwater are responsible for much denitrification at the watershed scale, per-area denitrification rates in soils and groundwater (kg N·km−2·yr−1) are, on average, approximately one-tenth the per-area rates of denitrification in lakes, rivers, estuaries, continental shelves, or OMZs. A number of potential approaches to increase denitrification on the landscape, and thus decrease N export to sensitive coastal systems exist. However, these have not generally been widely tested for their effectiveness at scales required to significantly reduce N export at the whole watershed scale.

One carp, two carp: are there more carp in the Wailoa River?

USGS Publications Warehouse

Mundy, Bruce C; Nico, Leo; Tagawa, Annette

2015-01-01

The February, 2015 issue of Hawaii Fishing News included the annual list of Hawai`i records for the largest fish of various species caught in the state. Among the new records was one for a 15-pound grass carp (Ctenopharyngodon idella) caught by Avery Berido in the Wailoa River at Hilo on September 13, 2013. A photograph taken by Mr. Berido of the record grass carp garnered our attention because pictured fish looked quite similar to another Asian carp species, the black carp (Mylopharyngodon piceus). Mr. Berido informed us that he also captured a 10-pound grass carp from the same river in June, 2013. After close examination of all of the photographs provided by Mr. Berido, we concluded that both fish from the Wailoa River were unusually dark grass carp, not black carp.

Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake

PubMed Central

Fan, Niannian; Nie, Ruihua; Wang, Qiang; Liu, Xingnian

2016-01-01

Changes in river channel erosion or deposition affect the geomorphic evolution, aquatic ecosystems, and river regulation strategies. Fluvial processes are determined by the flow, sediment and boundary conditions, and it has long been expected that increasing sediment supply will induce aggradation. Here, based on thorough field surveys, we show the unexpected undercutting of the piedmont rivers influenced by the 2008 Wenchuan (Ms 8.0) Earthquake. The rivers flow from the Longmen Mountain with significant topographic relief to the flat Chengdu plain. In the upstreams, sediment supply increased because of the landslides triggered by the earthquake, causing deposition in the upstream mountain reaches. However, the downstream plain reaches suffered undercutting instead of deposition, and among those rivers, Shiting River was the most seriously affected, with the largest undercutting depth exceeding 20 m. The reasons for this unexpected undercutting are proposed herein and relate to both natural and anthropogenic causes. In addition, we also demonstrate, at least for certain conditions, such as rivers flowing from large-gradient mountain regions to low-gradient plain regions, that upstream sediment pulses may induce aggradation in upstream and degradation in downstream, causing the longitudinal profile to steepen to accommodate the increasing sediment flux. PMID:27857220

A novel approach to flow estimation in tidal rivers

NASA Astrophysics Data System (ADS)

Moftakhari, H. R.; Jay, D. A.; Talke, S. A.; Kukulka, T.; Bromirski, P. D.

2013-08-01

Reliable estimation of river discharge to the ocean from large tidal rivers is vital for water resources management and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, flow records are often limited in length and/or quality and tidal records often predate discharge records. Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave as discharge increases. We use this phenomenon to develop a method of estimating river discharge for time periods with tidal data but no flow record. Employing sequential 32 day harmonic analyses of tidal properties, we calibrate San Francisco (SF), CA tide data to the Sacramento River delta outflow index from 1930 to 1990, and use the resulting relationship to hindcast river flow from 1858 to 1929. The M2 admittance (a ratio of the observed M2 tidal constituent to its astronomical forcing) best reproduces high flows, while low-flow periods are better represented by amplitude ratios based on higher harmonics (e.g.,M4/M22). Results show that the annual inflow to SF Bay is now 30% less than before 1900 and confirm that the flood of January 1862 was the largest since 1858.

Application of the SPARROW model to assess surface-water nutrient conditions and sources in the United States Pacific Northwest

USGS Publications Warehouse

Wise, Daniel R.; Johnson, Henry M.

2013-01-01

The watershed model SPARROW (Spatially Referenced Regressions on Watershed attributes) was used to estimate mean annual surface-water nutrient conditions (total nitrogen and total phosphorus) and to identify important nutrient sources in catchments of the Pacific Northwest region of the United States for 2002. Model-estimated nutrient yields were generally higher in catchments on the wetter, western side of the Cascade Range than in catchments on the drier, eastern side. The largest source of locally generated total nitrogen stream load in most catchments was runoff from forestland, whereas the largest source of locally generated total phosphorus stream load in most catchments was either geologic material or livestock manure (primarily from grazing livestock). However, the highest total nitrogen and total phosphorus yields were predicted in the relatively small number of catchments where urban sources were the largest contributor to local stream load. Two examples are presented that show how SPARROW results can be applied to large rivers—the relative contribution of different nutrient sources to the total nitrogen load in the Willamette River and the total phosphorus load in the Snake River. The results from this study provided an understanding of the regional patterns in surface-water nutrient conditions and should be useful to researchers and water-quality managers performing local nutrient assessments.

Source apportionment of ambient volatile organic compounds in the Pearl River Delta, China: Part II

NASA Astrophysics Data System (ADS)

Liu, Ying; Shao, Min; Lu, Sihua; Chang, Chih-Chung; Wang, Jia-Lin; Fu, Linlin

The chemical mass balance receptor model was applied to the source apportionment of 58 hydrocarbons measured at seven sites in a field campaign that examined regional air quality in the Pearl River Delta (PRD) region in the fall of 2004. A total of 12 volatile organic compound (VOC) emission sources were considered, including gasoline- and diesel-powered vehicle exhausts, headspace vapors of gasoline and diesel fuel, vehicle evaporative emissions, liquid petroleum gas (LPG) leakage, paint vapors, asphalt emissions from paved roads, biomass combustion, coal combustion, the chemical industry, and petroleum refineries. Vehicle exhaust was the largest source of VOCs, contributing to >50% of ambient VOCs at the three urban sites (Guangzhou, Foshan, and Zhongshan). LPG leakage played an important role, representing 8-16% of emissions at most sites in the PRD. Solvent usage was the biggest emitter of VOCs at Dongguan, an industrial site, contributing 33% of ambient VOCs. Similarly, at Xinken, a non-urban site, the evaporation of solvents and coatings was the largest emission source, accounting for 31% of emissions, probably because it was downwind of Dongguan. Local biomass combustion was a noticeable source of VOCs at Xinken; although its contribution was estimated at 14.3%, biomass combustion was the third largest VOC source at this site.

Nitrogen dynamics in the tidal freshwater Potomac River, Maryland and Virginia, water years 1979-81: A water-quality study of the tidal Potomac River and estuary

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

Shutz, D.J.

1989-01-01

On an annual basis, river supplied nitrate is the predominant form of N supplied to the tidal Potomac River from external sources. Much of the nitrate is associated with high flows that have rapid transit times through the tidal river. After the fall of 1980, initiation of advanced wastewater treatment at the Blue Plains Sewage Treatment Plant (STPP) reduced ammonia loading to the river by 90% and increased nitrate loading by a similar percentage. As a result, concentrations of ammonia during the 1981 low flow period were < 0.20 mg/L as N at alexandria, while nitrate concentrations were > 1.50more » mg/L as N. Despite the reduced availability of ammonia, 15-N uptake studies showed that phytoplankton preferred ammonia to nitrate unless ammonia concentrations were < 0.10 mg/L as N. Nitrification studies during 1981 using a 14-C uptake technique indicate that rates did not vary with sample location, except for one sample from the head of the tidal river, where the rates were much higher. Process models were used in conjunction with mass-balance determinations and individual process studies to estimate rates of processes that were not directly measured. It is estimated that denitrification removed 10 times as much nitrate from the water column during the summer of 1981 as during the summer of 1980. Sedimentation of particulate N is estimated to be the largest sink for N from the water column and was approximately equal to the external annual loading of all N constituents on a daily basis. In summer, when river flows usually are low, the tidal Potomac River appears to be a partially closed system rather than one dominated by transport. Nitrogen constituents, primarily from point sources, are taken up by phytoplankton converted to organic matter, and sedimented from the water column. Some of this N eventually becomes available again by means of benthic exchange. Removal, by transport, out of the tidal river is significant only during winter. 70 refs., 20 figs., 10 tabs.« less

Biogeochemistry of the Penobscot River watershed, Maine, USA: nutrient export patterns for carbon, nitrogen, and phosphorus.

PubMed

Cronan, Christopher S

2012-07-01

Watershed exports of carbon, nitrogen, phosphorus, major solutes, and suspended sediments were examined during five water years in the Penobscot River basin, which forms part of the Gulf of Maine watershed. Mean annual exports of dissolved organic carbon (DOC) in the Penobscot River were 58 kg C ha(-1) year(-1), whereas cumulative yearly watershed flux of DOC during the study period ranged from 8.6 to 16.1 × 10(10) g C year(-1) and averaged 11.7 × 10(10) g C year(-1). Watershed exports of total soluble N (TN) and total soluble P in the Penobscot River averaged 1.9 and 0.02 kg ha(-1) year(-1), respectively. Companion studies in two other major Maine rivers indicated that mean annual exports of DOC and TN in the Androscoggin River were 40 kg C ha(-1) year(-1) and 2.0 kg N ha(-1) year(-1), whereas exports in the Kennebec River were 43 kg C ha(-1) year(-1) and 2.2 kg N ha(-1) year(-1). Extrapolation of results from this investigation and a previous complementary study indicates that estuaries and coastal waters in the Gulf of Maine receive at least 1.0 × 10(10) g N year(-1) and 2.5 × 10(11) g C year(-1) in combined runoff from the four largest Maine river basins. Soluble exports of Ca + Mg + Na minus wet deposition inputs of cations in the Penobscot system were approximately 1,840 mol(c) ha(-1) year(-1), which represents a minimum estimate of cation denudation from the watershed. Based on its low N and P export rates, the Penobscot River watershed represents an example of reference conditions for use as a benchmark in ecological assessments of river water quality restoration or impairment. In addition, the biogeochemical metrics from this study provide an historical baseline for analysis of future trends in nutrient exports from the Penobscot watershed as a function of changing climatic and land use patterns.

Geomorphic response to large-dam removal: Impacts of a massive sediment release to the Elwha River, Washington

NASA Astrophysics Data System (ADS)

Magirl, C. S.; Ritchie, A.; Bountry, J.; Randle, T. J.; East, A. E.; Hilldale, R. C.; Curran, C. A.; Pess, G. R.

2015-12-01

The 2011-2014 staged removals of two nearly century-old dams on the Elwha River in northwest Washington State, the largest dam-removal project in the United States, exposed 21 million m3 of reservoir-trapped sand and gravel to potential fluvial transport. The river downstream from the dams is gravel bedded with a pool-riffle morphology. The river flows 20 km to the marine environment through a riparian corridor lined with large wood and having relatively few anthropogenic alterations. This moderately natural pre-dam-removal condition afforded an unprecedented opportunity to study river response to an anticipated massive sediment release. Four years into the project, 12 million m3 of sediment eroded from the former reservoirs with about 90% of the total load transported to the marine environment. Annualized sediment discharge was as great as 20 times the background natural load. Initial river response to the arrival of the first large sediment pulse was the nearly complete filling of the river's previously sediment-starved pools, widespread filling of side channels, and increased braiding index. In year 2, during maximum aggradation, the river graded to a plane-bedded system, efficiently conveying sediment to the marine environment. Modest peak flows (<2-yr return period) in year 2 promoted sediment transport but caused little large-scale geomorphic disturbance by channel migration or avulsions. As the river processed the sediment pulse, pools returned and the braiding index decreased in years 3-4. Higher peak flows in year 4 caused localized channel widening and migration but no major avulsions. Gauging indicated sand dominated the first stages of sediment release, but fluvial loads coarsened through time with progressive arrival of larger material. The literature suggests the Elwha River sediment wave should have evolved through dispersion with little translation. However, morphologic measurements and data from a stage-gauge network indicated patterns of deposition, sediment transport, and sediment-wave evolution were heterogeneously complex, challenging our efforts to classify the sediment wave in terms of simple dispersion or translation.

Contamination characteristics, ecological risk and source identification of trace metals in sediments of the Le'an River (China).

PubMed

Chen, Haiyang; Chen, Ruihui; Teng, Yanguo; Wu, Jin

2016-03-01

Recognizing the pollution characteristics of trace metals in river sediments and targeting their potential sources are of key importance for proposing effective strategies to protect watershed ecosystem health. In this study, a comprehensive investigation was conducted to identify the contamination and risk characteristics of trace metals in sediments of Le'an River which is a main tributary of the largest freshwater lake in China, Poyang Lake. To attain this objective, several tools and models were considered. Geoaccumulation index and enrichment factor were used to understand the general pollution characteristic of trace metals in sediments. Discriminant analysis was applied to identify the spatial variability of sediment metals. Sediment quality guidelines and potential ecological risk index were employed for ecological risk evaluation. Multivariate curve resolution-alternating least square was proposed to extract potential pollution sources, as well as the application of Monte-Carlo simulation for uncertainty analysis of source identification. Results suggested that the sediments in Le'an River were considerably polluted by the investigated trace metals (Cd, Cr, As, Hg, Pb, Cu, Zn and Ni). Sediment concentrations of these metals showed significant spatial variations. The potential ecological risk lay in high level. Comparatively speaking, the metals of Cd, Cu and Hg were likely to result in more harmful effects. Mining activities and the application of fertilizers and agrochemicals were identified as the main anthropogenic sources. To protect the ecological system of Le'an River and Poyang Lake watershed, industrial mining and agricultural activities in this area should to be strictly regulated. Copyright © 2015 Elsevier Inc. All rights reserved.

Hydrologic description of the Braden River watershed, west-central Florida

USGS Publications Warehouse

DelCharco, M.J.; Lewelling, B.R.

1997-01-01

The Braden River watershed drains an 83-square mile area in west-central Florida and is the largest tributary to the Manatee River. The hydrology of the Braden River was altered in 1936 when the city of Bradenton created Ward Lake, a reservoir with an 838-foot broad-crested weir 6 miles upstream from the mouth. In 1985 the reservoir, which is the sole source of drinking water for the city of Bradenton, was expanded and supplies an annual average of 5.7 million gallons of water per day. The Braden River can be hydrologically divided into three distinct sections that include an 8.6-mile reach of naturally incised, free-flowing channel; a 6.4-mile reach of impounded river created by the Ward Lake reservoir and weir; and a 6-mile reach of tidal estuary. Ten first-order and two second-order tributaries that flow into the Braden River were examined in this report. The Braden River watershed is dominated by low topographic relief. The two physiographic zones that contain the Braden River watershed, the Gulf Coast Lowlands and De Soto Plain, are both poorly drained and have numerous depressional features. The climate is subtropical with an annual average rainfall of 56 inches, annual average temperatures of 72 degrees Fahrenheit, and estimated annual lake evaporation of 52 inches. The soil series in the watershed are predominantly Myakka-Cassia and the EauGallie-Floridana; these series are characterized as nearly level and poorly drained soils. Land use within the watershed is the fastest changing characteristic that affects the hydrology of the system. The western half of the watershed is typically urban and includes parts of the city of Bradenton. Land use in the eastern half of the watershed is predominantly agricultural, but the explosive population growth of the area is driving the development of medium to high-density residential communities. The three major aquifers underlying the Braden River watershed are the surficial, intermediate, and Floridan aquifer systems. The surficial aquifer generally is underlain in places by a clay layer that enhances the ground-water flow of the surficial aquifer to surface-water bodies. The intermediate aquifer system has discontinuous water-bearing units, but retards ground-water movement between the surficial and Floridan aquifer system. The Floridan aquifer system consists of the Upper and Lower Floridan aquifers separated by a middle confining unit. The Upper Floridan aquifer is the primary source for ground-water withdrawals in the watershed and has, at times, heads 20 feet higher than land-surface elevation. Discharge over the Ward Lake weir into the tidal estuary was measured using volumetric and standard discharge measurement techniques. Annual mean flow for water years 1993 and 1994 were 59.7 and 57.3 cubic feet per second, respectively. Weir coefficients, calculated from discharge measurements, ranged from 0.023 to 2.99, depending on the head of water over the weir, and the method of determining length of flow on the weir. Weir coefficients calculated from the theoretical rating ranged from 0.032 to 3.11. No significant seepage was found around the ends of the weir, and no leakage was detected through the weir.

The cost of noncooperation in international river basins

NASA Astrophysics Data System (ADS)

Tilmant, A.; Kinzelbach, W.

2012-01-01

In recent years there has been a renewed interest for water supply enhancement strategies in order to deal with the exploding demand for water in some regions, particularly in Asia and Africa. Within such strategies, reservoirs, especially multipurpose ones, are expected to play a key role in enhancing water security. This renewed impetus for the traditional supply-side approach to water management may indeed contribute to socioeconomic development and poverty reduction if the planning process considers the lessons learned from the past, which led to the recommendations by the World Commission on Dams and other relevant policy initiatives. More specifically, the issues dealing with benefit sharing within an efficient and equitable utilization of water resources are key elements toward the successful development of those river basins. Hence, there is a need for improved coordination and cooperation among water users, sectors, and riparian countries. However, few studies have explicitly tried to quantify, in monetary terms, the economic costs of noncooperation, which we believe to be important information for water managers and policy makers, especially at a time when major developments are planned. In this paper we propose a methodology to assess the economic costs of noncooperation when managing large-scale water resources systems involving multiple reservoirs, and where the dominant uses are hydropower generation and irrigated agriculture. An analysis of the Zambezi River basin, one of the largest river basins in Africa that is likely to see major developments in the coming decades, is carried out. This valuation exercise reveals that the yearly average cost of noncooperation would reach 350 million US$/a, which is 10% of the annual benefits derived from the system.

Wave climate, sediment supply and the depth of the sand-mud transition: A global survey

USGS Publications Warehouse

George, D.A.; Hill, P.S.

2008-01-01

The influences of wave climate and sediment supply on the depths of sand-mud transitions (hSMT) are investigated. Depths of sand-mud transitions (SMT) are based on published granulometric data from surface samples gathered from 14 sites in different wave-dominated coastal environments with fluvial input, including high energy (Columbia, Eel, Russian, San Lorenzo, Copper, and Nepean rivers), moderate energy (Ebro, Nile, Santa Clara, Tseng-wen and Kao-ping rivers), and low energy (Po, Pescara and Tronto rivers) regimes. Geometric mean diameter (GMD) and mud percent are compiled from samples along shore-normal transects, and significant correlation is found between these two textural descriptors. Nominally, the SMT is defined as the transition from GMD > 63????m to 25% mud. This dual definition is applied to the 14 systems, and hSMT is tabulated for each system. Correlation is found between hSMT and the depth at which wave-induced bottom shear stress equals the critical erosion shear stress of the largest mud particles and also between hSMT and significant wave height. Lack of correlation between hSMT and sediment load of nearby rivers indicates either that the influence of sediment supply on depth of the sand-mud transition is small or is not adequately represented in this study. Shelf width and slope do not correlate with residuals from a formalized linear relationship between hSMT and significant wave height. The relationship between hSMT and wave climate is useful for calibration of numerical models of erosion and deposition in wave-dominated coastal environments, for prediction of seabed properties in remote or inaccessible areas, and for reconstruction of paleodepth based on facies changes from sand to mud in ancient rocks. ?? 2008.

Scale-dependent effects of land cover on water physico-chemistry and diatom-based metrics in a major river system, the Adour-Garonne basin (South Western France).

PubMed

Tudesque, Loïc; Tisseuil, Clément; Lek, Sovan

2014-01-01

The scale dependence of ecological phenomena remains a central issue in ecology. Particularly in aquatic ecology, the consideration of the accurate spatial scale in assessing the effects of landscape factors on stream condition is critical. In this context, our study aimed at assessing the relationships between multi-spatial scale land cover patterns and a variety of water quality and diatom metrics measured at the stream reach level. This investigation was conducted in a major European river system, the Adour-Garonne river basin, characterized by a wide range of ecological conditions. Redundancy analysis (RDA) and variance partitioning techniques were used to disentangle the different relationships between land cover, water-chemistry and diatom metrics. Our results revealed a top-down "cascade effect" indirectly linking diatom metrics to land cover patterns through water physico-chemistry, which occurred at the largest spatial scales. In general, the strength of the relationships between land cover, physico-chemistry, and diatoms was shown to increase with the spatial scale, from the local to the basin scale, emphasizing the importance of continuous processes of accumulation throughout the river gradient. Unexpectedly, we established that the influence of land cover on the diatom metric was of primary importance both at the basin and local scale, as a result of discontinuous but not necessarily antagonist processes. The most detailed spatial grain of the Corine land cover classification appeared as the most relevant spatial grain to relate land cover to water chemistry and diatoms. Our findings provide suitable information to improve the implementation of effective diatom-based monitoring programs, especially within the scope of the European Water Framework Directive. © 2013 Elsevier B.V. All rights reserved.

Working with Decision Makers to Improve Energy-Water System Resiliency in the Lower Hudson River Basin

NASA Astrophysics Data System (ADS)

Fellows, J. D.; Schoonen, M. A.; Pullen, J.; González, J. E.; Saleh, F.; Bhatt, V.

2017-12-01

Nearly half of the 180 million people living in the eastern U.S. reside in coastal watershed or shoreline counties. The population density of these areas continues to increase, driving an increase in energy-water (EW) system demand and expansion of critical infrastructure. Along with population, these areas are also being stressed by environmental and technology stresses, including climate change. We have been working with decision makers in the Lower Hudson River Basin (LHRB) to develop the tools and data needed to better understand and improve the resiliency of LHRB EW systems facing these kinds of stresses. The LHRB represents: 1) a coastal environment subject to sea level rise that is among the fastest in the East; 2) one of the steepest gradients in population density in the US, with Manhattan the most densely populated coastal county in the nation; 3) a EWN infrastructure serving the largest metropolitan area in the US and the financial center of the world; 4) a history of environmental impacts, ranging from heatwaves, hurricanes to localized storms, that can be used to hindcast; and 5) a wealth of historic and real-time data, extensive monitoring facilities and existing specific sector models that can be leveraged. This presentation will focus on the lessons learned working with the LHRB decision makers.

Scaling from instantaneous remote-sensing-based latent heat flux to daytime integrated value with the help of SiB2

NASA Astrophysics Data System (ADS)

Song, Yi; Ma, Mingguo; Li, Xin; Wang, Xufeng

2011-11-01

This research dealt with a daytime integration method with the help of Simple Biosphere Model, Version 2 (SiB2). The field observations employed in this study were obtained at the Yingke (YK) oasis super-station, which includes an Automatic Meteorological Station (AMS), an eddy covariance (EC) system and a Soil Moisture and Temperature Measuring System (SMTMS). This station is located in the Heihe River Basin, the second largest inland river basin in China. The remotely sensed data and field observations employed in this study were derived from Watershed Allied Telemetry Experimental Research (WATER). Daily variations of EF in temporal and spatial scale would be detected by using SiB2. An instantaneous midday EF was calculated based on a remote-sensing-based estimation of surface energy budget. The invariance of daytime EF was examined using the instantaneous midday EF calculated from a remote-sensing-based estimation. The integration was carried out using the constant EF method in the intervals with a steady EF. Intervals with an inconsistent EF were picked up and ET in these intervals was integrated separately. The truth validation of land Surface ET at satellite pixel scale was carried out using the measurement of eddy covariance (EC) system.

Hydrologic and Geomorphic Impacts of Glacial Lake Outburst Floods From Low-Order Tributaries

NASA Astrophysics Data System (ADS)

McCoy, S. W.; Jacquet, J.; McGrath, D.; George, D. L.; Koschitzki, R.; Nimick, D.; Fahey, M. J.; Okuinghttons, J.

2017-12-01

Lakes dammed by glacial ice or moraines are common features in the headwaters of both glaciated and recently deglaciated catchments. These dams can fail releasing water in a glacial lake outburst flood (GLOF), which raises the question: do GLOFs from low-order tributaries significantly alter the hydrology and sediment transport regimes of the large mainstem rivers to which they drain? Here we use repeat satellite imagery, in situ measurements, and 2D hydrodynamic modeling to quantify the hydrologic and geomorphic changes that resulted from 22 GLOFs that occurred between 2008 and 2016 from Lago Cachet Dos, Patagonia, Chile. We find that the complicated flood path that includes two lakes and a broad floodplain can dampen peak discharges from over 15,000 m³/s at the source lake to generally less than 2,000 m³/s where the floods enter the mainstem Rio Baker, 40 km downstream. Despite this dampening of GLOF peak discharge, peak discharges still exceeded the peak annual discharge of the Rio Baker, the largest river in Chile by volume, by 1 to 2 times, which in turn increased the frequency and magnitude of flood events. We also document the sediment dynamics in the source lake, where we find that over 25,000,000 m³ of stored sediment was removed during the GLOF cycle that began in 2008. Further downstream, repeat satellite imagery reveals that the large discharges associated with GLOFs produced a nonsteady channel configuration in which old stable channels were abandoned, many new channels were formed, and conveyance capacity changed, best illustrated by the 200 m of delta progradation from the GLOF-affected tributary into the Rio Baker that locally narrowed the Rio Baker channel width from 300 m to 60 m. In total, this analysis demonstrates that GLOFs from distant source lakes can have an outsized impact, both in terms of changing flood characteristics as well as sediment transport, even on the largest river systems.

Reaction and relaxation in a coarse-grained fluvial system following catchment-wide disturbance

NASA Astrophysics Data System (ADS)

Tunnicliffe, Jon; Brierley, Gary; Fuller, Ian C.; Leenman, Anya; Marden, Mike; Peacock, Dave

2018-04-01

The Waiapu River catchment (drainage area of 1734-km2) is one of the most prolific conveyors of sediment in the world, annually delivering roughly 35 Mt of fine material to the ocean from eroding gullies, hillslopes, and reworked sediment on valley floors. Tectonic and geologic influences, in combination with a dynamic climate influenced by tropical cyclones and clearance of vegetation from steep hillslopes, predisposes this region to high rates of erosion. The bedload sediment regime of the river is strongly influenced by several exceptionally large gullies and gully complexes that produce a coarse-grained, poorly sorted sediment mixture. Rapid abrasion and breakdown leads to high rates of suspended sediment yield. A wave of bedload material, manifesting as elevated bed levels and significant widening of active alluvial fills, has been triggered by large inputs of hillslope material from a few key tributary catchments following Cyclone Bola in 1988. We review the evidence for the relaxation process of the sedimentary system in the subsequent 29 years, appraising some of the legacy effects that may endure, as associated with reworking of the considerable alluvial stores within the Waiapu system. We use Structure-from-Motion (SfM) techniques and archival aerial photos to quantify changes in sediment storage at the base of two major gully systems in recent decades. A record of over 850 cross section surveys at 62 sites on 10 rivers throughout the catchment (1958-2017) indicates recent transition from a trend of continuous accumulation to downcutting and remobilisation of valley-bottom deposits. The channel cross sections provide a minimum estimate of sediment flux from source areas to the lower reaches of the river, giving a rudimentary but spatially extensive picture of the wave of material cascading through the drainage network. The largest impacts occur in the upper steepland rivers, closest to the landslide-derived sediment supply. Transport rates here, as inferred from cross section change, are at a maximum during an aggradational phase following Cyclone Bola then taper off, despite the large sediment accumulations remaining in the system. As of 2017, the river is in the process of incising the upper extents of this deposit on a trajectory of recovery toward pre-Bola conditions. The compilation of cross section data provides us with new insights into the sensitivity of particular sites in the landscape, as well as the changing relationship between reach sediment storage and transport rates during the response and relaxation phase of a major disturbance in a large catchment.

Embryonic and larval development and early behavior in grass carp, Ctenopharyngodon idella: implications for recruitment in rivers

USGS Publications Warehouse

George, Amy E.; Chapman, Duane C.

2015-01-01

With recent findings of grass carp Ctenopharyngodon idella in tributaries of the Great Lakes, information on developmental rate and larval behavior is critical to efforts to assess the potential for establishment within the tributaries of that region. In laboratory experiments, grass carp were spawned and eggs and larvae reared at two temperature treatments, one "cold" and one "warm", and tracked for developmental rate, egg size, and behavior. Developmental rate was quantified using Yi's (1988) developmental stages and the cumulative thermal units method. Grass carp had a thermal minimum of 13.5°C for embryonic stages and 13.3°C for larval stages. Egg size was related to temperature and maternal size, with the largest eggs coming from the largest females, and eggs were generally larger in warmer treatments. Young grass carp larvae exhibited upward and downward swimming interspersed with long periods of lying on the bottom. Swimming capacity increased with ontogeny, and larvae were capable of horizontal swimming and position holding with gas bladder emergence. Developmental rates, behavior, and egg attributes can be used in combination with physical parameters of a river to assess the risk that grass carp are capable of reproduction and recruitment in rivers.

A New Data Acquisition Portal for the Sacramento River Settlement Contractors

NASA Astrophysics Data System (ADS)

Narlesky, P. E., C. A.; Williams, P. E., A. M.

2017-12-01

In 1964, the United States Bureau of Reclamation (Reclamation) executed settlement contracts with the Sacramento River Settlement Contractors (SRSC), entities which hold water rights along the Sacramento River with area of origin protection or that are senior to Reclamation's water rights for Shasta Reservoir. Shasta is the cornerstone of the federal Central Valley Project (CVP), one of the nation's largest multi-purpose water conservation programs. In order to optimize CVP operations for multiple beneficial uses including water supply, fisheries, water quality, and waterfowl habitat, the SRSC voluntarily agreed to adaptively manage diversions throughout the year in close coordination with Reclamation. MBK Engineers assists the SRSC throughout this process by collecting, organizing, compiling, and distributing diversion data to Reclamation and others involved in operational decisions related to Shasta Reservoir and the CVP. To improve and expand participation in diversions reporting, we have developed the SRSC Web Portal, which launches a data-entry dashboard for members of the SRSC to facilitate recording and transmittal of both predicted and observed monthly and daily flow diversion data. This cloud-hosted system leverages a combination of Javascript interactive visualization libraries with a database-backed Python web framework to present streamlined data-entry forms and valuable SRSC program summary illustrations. SRSC program totals, which can now be aggregated through queries to the web-app's database backend, are used by Reclamation, SRSC, fish agencies, and others to inform operational decisions. By submitting diversion schedules and tracking actual diversions through the portal, contractors will also be directly contributing to the development of a richer and more consistently-formatted historical record for demand hydrology in the Sacramento River Watershed; this may be useful in future water supply studies. Adoption of this technology will foster an increased appreciation for the historical record of individual and combined Sacramento River diversions relative to the overall system.

Wisconsin Indians.

ERIC Educational Resources Information Center

Lurie, Nancy Oestreich

Wisconsin encompasses an astonishingly representative illustration of the total historical development of federal Indian policy and Indian reactions to it. Wisconsin's Indian population (at least 25,000 people) is the third largest east of the Mississippi River and offers great diversity (3 major linguistic stocks, 6 broad tribal affiliations, and…

Regional-scale controls on dissolved nitrous oxide in the Upper Mississippi River

USGS Publications Warehouse

Turner, P.A.; Griffis, T.J.; Baker, J.M.; Lee, X.; Crawford, John T.; Loken, Luke C.; Venterea, R.T.

2016-01-01

The U.S. Corn Belt is one of the most intensive agricultural regions of the world and is drained by the Upper Mississippi River (UMR), which forms one of the largest drainage basins in the U.S. While the effects of agricultural nitrate (NO3-) on water quality in the UMR have been well documented, its impact on the production of nitrous oxide (N2O) has not been reported. Using a novel equilibration technique, we present the largest data set of freshwater dissolved N2O concentrations (0.7 to 6 times saturation) and examine the controls on its variability over a 350 km reach of the UMR. Driven by a supersaturated water column, the UMR was an important atmospheric N2O source (+68 mg N2ONm-2 yr-1) that varies nonlinearly with the NO3-concentration. Our analyses indicated that a projected doubling of the NO3-concentration by 2050 would cause dissolved N2O concentrations and emissions to increase by about 40%.

[Anthropogenic ammonia emission inventory and characteristics in the Pearl River Delta Region].

PubMed

Yin, Sha-sha; Zheng, Jun-yu; Zhang, Li-jun; Zhong, Liu-ju

2010-05-01

Based on the collected activity data and emission factors of anthropogenic ammonia sources, a 2006-based anthropogenic ammonia emission inventory was developed for the Pearl River Delta (PRD) region by source categories and cities with the use of appropriate estimation methods. The results show: (1) the total NH3 emission from anthropogenic sources in the PRD region was 194. 8 kt; (2) the agriculture sources were major contributors of anthropogenic ammonia sources, in which livestock sources shared 62.1% of total NH3 emission and the contribution of application of nitrogen fertilizers was 21.7%; (3) the broiler was the largest contributor among the livestock sources, accounting for 43.4% of the livestock emissions, followed by the hog with a contribution of 32.1%; (4) Guangzhou was the largest ammonia emission city in the PRD region, and then Jiangmen, accounting for 23.4% and 19.1% of total NH3 emission in the PRD region respectively, with major sources as livestock sources and application of nitrogen fertilizers.

Sediment Equilibrium and Diffusive Fluxes in Relation to Phosphorus Dynamics in the Turbid Minnesota River

DTIC Science & Technology

2009-01-01

extractable P and K in a sandy clay loam soil under continuous corn ( Zea mays L .). Can J Soil Sci 75:361-367. Zhang, T. Q., A. F. MacKenzie, B. C...diffusive P flux from deposited sediment stored in river channels may also play a role in soluble P control. Ranges in equilibrium partitioning between...largest plants in the State of Minnesota, discharge (average discharge = 1.8 m3 s-1) at effluent P concentrations of 1.5 mg L -1 or less. A 538-megawatt

Earth observations taken from shuttle orbiter Atlantis during STS-84 mission

NASA Image and Video Library

1997-05-21

STS084-701-026 (15-24 May 1997) --- The Volga River enters the Caspian, the world's largest inland sea, from the north in this high oblique view. The Volga, the principle waterway of western Russian, is considered the historic cradle of Russia. The Ural River, east of the Volga, also enters the northern part of the Caspian. The dimensions of the Caspian are 1,200 kilometers (750 miles) from north to south, but averages 320 kilometers (200 miles) in width. Oil and natural gas are this regions most important resources.

Temporal and Spatial Variability in the Partitioning and Flux of Riverine Iron Delivered to the Gulf of Alaska

NASA Astrophysics Data System (ADS)

Schroth, A. W.; Crusius, J.; Kroeger, K. D.; Hoyer, I. R.; Osburn, C. L.

2010-12-01

Iron (Fe) is a micronutrient that is thought to limit phytoplankton productivity in offshore waters of the Gulf of Alaska (GoA). However, it has been proposed that in coastal regions where offshore, Fe-limited, nitrate-rich waters mix with relatively Fe-rich river plumes, productive ecosystems and fisheries result. Indeed, an observed northward increase in phytoplankton biomass along the pacific coast of North America has been attributed to higher input of riverine Fe to coastal waters, suggesting that many of the coastal ecosystems of the North Pacific rely heavily on this input of Fe as a nutrient source. Based on our studies of the Copper River (the largest point source of freshwater to the GoA) and its tributaries, it is clear that riverine Fe delivered to the GoA is primarily derived from fine glacial flour generated by glacial weathering, which imparts a unique partitioning of Fe species and Fe size fractionation in coastal river plumes. Furthermore, the distribution of Fe species and size fractionation exhibits significant seasonal and spatial variability based on the source of iron within the watershed, which varies from glacial mechanical weathering of bedrock to internal chemical processing in portions of watersheds with forest and wetland land covers. These findings are relevant to our understanding of the GoA biogeochemical system as it exists today and can help to predict how the system may evolve as glaciers within the GoA watershed continue to recede.

Rural plastic emissions into the largest mountain lake of the Eastern Carpathians.

PubMed

Mihai, Florin-Constantin

2018-05-01

The lack of proper waste collection systems leads to plastic pollution in rivers in proximity to rural communities. This environmental threat is more widespread among mountain communities which are prone to frequent flash floods during the warm season. This paper estimates the amounts of plastic bottles dumped into the Izvoru Muntelui lake by upstream rural communities. The plastic pollution dimension between seasonal floods which affected the Bistrita catchment area during 2005-2012 is examined. The floods dumped over 290 tonnes of plastic bottles into the lake. Various scenarios are tested in order to explain each amount of plastic waste collected by local authorities during sanitation activities. The results show that rural municipalities are responsible for 85.51% of total plastic bottles collected during 2005-2010. The source of plastic pollution is mainly local. The major floods of July 2008 and June 2010 collected most of the plastic bottles scattered across the Bistrita river catchment (56 villages) and dumped them into the lake. These comparisons validate the proposed method as a reliable tool in the assessment process of river plastic pollution, which may also be applied in other geographical areas. Tourism and leisure activities are also found to be responsible for plastic pollution in the study area. A new regional integrated waste management system should improve the waste collection services across rural municipalities at the county level when it is fully operational. This paper demonstrates that rural communities are significant contributors of plastics into water bodies.

Rural plastic emissions into the largest mountain lake of the Eastern Carpathians

PubMed Central

2018-01-01

The lack of proper waste collection systems leads to plastic pollution in rivers in proximity to rural communities. This environmental threat is more widespread among mountain communities which are prone to frequent flash floods during the warm season. This paper estimates the amounts of plastic bottles dumped into the Izvoru Muntelui lake by upstream rural communities. The plastic pollution dimension between seasonal floods which affected the Bistrita catchment area during 2005–2012 is examined. The floods dumped over 290 tonnes of plastic bottles into the lake. Various scenarios are tested in order to explain each amount of plastic waste collected by local authorities during sanitation activities. The results show that rural municipalities are responsible for 85.51% of total plastic bottles collected during 2005–2010. The source of plastic pollution is mainly local. The major floods of July 2008 and June 2010 collected most of the plastic bottles scattered across the Bistrita river catchment (56 villages) and dumped them into the lake. These comparisons validate the proposed method as a reliable tool in the assessment process of river plastic pollution, which may also be applied in other geographical areas. Tourism and leisure activities are also found to be responsible for plastic pollution in the study area. A new regional integrated waste management system should improve the waste collection services across rural municipalities at the county level when it is fully operational. This paper demonstrates that rural communities are significant contributors of plastics into water bodies. PMID:29892426

Hydrology of the middle San Pedro area, southeastern Arizona

USGS Publications Warehouse

Cordova, Jeffrey T.; Dickinson, Jesse; Beisner, Kimberly R.; Hopkins, Candice B.; Kennedy, Jeffrey R.; Pool, Donald R.; Glenn, Edward P.; Nagler, Pamela L.; Thomas, Blakemore E.

2015-05-05

In the middle San Pedro Watershed in southeastern Arizona, groundwater is the primary source of water supply for municipal, domestic, industrial, and agricultural use. The watershed comprises two smaller subareas, the Benson subarea and the Narrows-Redington subarea. Early 21st century projections for heavy population growth in the watershed have not yet become a reality, but increased groundwater withdrawals could have undesired consequences - such as decreased base flow to the San Pedro River, and groundwater-level declines - that would lead to the need to deepen existing wells. This report describes the hydrology, hydrochemistry, water quality, and development of a groundwater budget for the middle San Pedro Watershed, focusing primarily on the elements of groundwater movement that could be most useful for the development of a groundwater modelPrecipitation data from Tombstone, Arizona, and base flow at the stream-gaging station on the San Pedro River at Charleston both show relatively dry periods during the 1960s through the mid-1980s and in the mid-1990s to 2009, and wetter periods from the mid-1980s through the mid-1990s. Water levels in four out of five wells near the mountain fronts show cyclical patterns of recharge, with rates of recharge greatest in the early 1980s through the mid-1990s. Three wells near the San Pedro River recorded their lowest levels during the 1950s to the mid-1960s. The water-level record from one well, completed in the confined part of the coarse-grained lower basin fill, showed a decline of approximately 21 meters.Annual flow of the San Pedro River, measured at the Charleston and Redington gages, has decreased since the 1940s. The median annual streamflow and base flow at the gaging station on the river near Tombstone has decreased by 50 percent between the periods 1968–1986 and 1997–2009. Estimates of streamflow infiltration along the San Pedro River during 1914–2009 have decreased 44 percent, with the largest decreases in the months June–October in the Benson subarea. In the Narrows-Redington subarea, streamflow infiltration has decreased about 65 percent during 1914–2009.The average annual outflow (27.6 hm3/year [cubic hectometers per year]) from the Benson subarea aquifer for water years 2001 through 2009 exceeded the inflows (20.0 hm3/ yr) by 7.60 hm3/yr. In the Narrows-Redington subarea for the same period, the average annual outflow (15.7 hm3/yr) from the aquifer system exceeded the inflows (13.8 hm3/yr) by nearly 2 hm3/yr. The largest withdrawals of groundwater in both subareas are for irrigation; these withdrawals peaked in 1973 and have been steadily decreasing since then. Recharge from streamflow infiltration exceeded recharge from the mountain-front and from ephemeral channels in the Benson subarea. In the Narrows-Redington subarea, however, recharge from mountain-front and ephemeral channel recharge exceeded recharge from streamflow infiltration. Evapotranspiration by phreatophytes accounts for the largest outflow of groundwater for both subareas—78 percent of the outflow in the Narrows-Redington subarea and 62 percent of the outflow in the Benson subarea.Precipitation, surface-water, and groundwater chemistry and isotope data indicated the relative age and residence time of groundwater, the amount of interaction between geologic sources and groundwater, and how recharge elevation and season were related to the presence of modern water. The bedrock aquifer receives modern recharge (

Concentrations and transport of suspended sediment, nutrients, and pesticides in the lower Mississippi-Atchafalaya River subbasin during the 2011 Mississippi River flood, April through July

USGS Publications Warehouse

Welch, Heather L.; Coupe, Richard H.; Aulenbach, Brent T.

2014-01-01

High streamflow associated with the April–July 2011 Mississippi River flood forced the simultaneous opening of the three major flood-control structures in the lower Mississippi-Atchafalaya River subbasin for the first time in history in order to manage the amount of water moving through the system. The U.S. Geological Survey (USGS) collected samples for analysis of field properties, suspended-sediment concentration, particle-size, total nitrogen, nitrate plus nitrite, total phosphorus, orthophosphate, and up to 136 pesticides at 11 water-quality stations and 2 flood-control structures in the lower Mississippi-Atchafalaya River subbasin from just above the confluence of the upper Mississippi and Ohio Rivers downstream from April through July 2011. Monthly fluxes of suspended sediment, suspended sand, total nitrogen, nitrate plus nitrite, total phosphorus, orthophosphate, atrazine, simazine, metolachlor, and acetochlor were estimated at 9 stations and 2 flood-control structures during the flood period. Although concentrations during the 2011 flood were within the range of what has been observed historically, concentrations decreased during peak streamflow on the lower Mississippi River. Prior to the 2011 flood, high concentrations of suspended sediment and nitrate were observed in March 2011 at stations downstream of the confluence of the upper Mississippi and Ohio Rivers, which probably resulted in a loss of available material for movement during the flood. In addition, the major contributor of streamflow to the lower Mississippi-Atchafalaya River subbasin during April and May was the Ohio River, whose water contained lower concentrations of suspended sediment, pesticides, and nutrients than water from the upper Mississippi River. Estimated fluxes for the 4-month flood period were still quite high and contributed approximately 50 percent of the estimated annual suspended sediment, nitrate, and total phosphorus fluxes in 2011; the largest fluxes were estimated at the water-quality station located at Vicksburg, Mississippi. The majority of the suspended-sediment flux introduce into the lower Mississippi-Atchafalaya River subbasin during the 2011 flood was in the form of fine-grained particles from the upper Mississippi River—77 percent of the suspended-sediment flux compared to 23 percent from the Ohio River. As water moved downstream along the lower Mississippi River, there were losses in suspended-sediment flux because of deposition and backwater areas. Fluxes showed a greater response to increased streamflow in the Atchafalaya River than in the lower Mississippi River. The result was a gain in suspended-sediment flux with distance downstream in the Atchafalaya River because of resuspension of previously deposited materials—particularly sand particles. Overall, 13 percent less suspended sediment left the lower Mississippi-Atchafalaya River subbasin than entered it from the confluence of the upper Mississippi and Ohio Rivers during the flood. The loss in suspended-sediment flux during the flood accounted for 14 percent of the 2011 annual suspended-sediment flux loss within the lower Mississippi-Atchafalaya River subbasin. Nitrate composed approximately 70 percent of the total nitrogen flux at all of the sampled water-quality stations, excluding the Arkansas River. Almost 2.4 times more nitrate flux entered the lower Mississippi-Atchafalaya River subbasin from the upper Mississippi River than from the Ohio River. As nitrate moved down the lower Mississippi River and the Atchafalaya River, there were no substantial losses or gains in flux, indicating that nitrate moved conservatively within the subbasin during the 2011 flood. Although streamflow was the largest on record, nitrate flux during the flood period resulted in a zone of hypoxia in the Gulf of Mexico that was only the tenth largest on record. The flux of total phosphorus in the lower Mississippi-Atchafalaya River subbasin during the 2011 flood was strongly related to suspended-sediment flux at most of the stations. There were significant gains in total phosphorus flux in the Atchafalaya River during the flood period and losses between the stations along the lower Mississippi River. Overall, however, the amount of total phosphorus flux that left the lower Mississippi-Atchafalaya River subbasin was only 1.7 percent less than the flux that entered it from the upper Mississippi River and the Ohio River, indicating that total phosphorus flux within the subbasin during the flood was conservative. As streamflow was decreasing within the lower Mississippi-Atchafalaya River subbasin, orthophosphate composed an increasing percentage of the total phosphorus concentration, probably because of the return of waters low in oxygen concentration from areas such as inundated lands, backwater streams, and floodways. Poorly oxygenated waters promote the release of sediment-bound phosphorus into the more-readily available dissolved form (measured as orthophosphate in this study). Because of processing within the subbasin during the flood period, there was a 25-percent gain in orthophosphate flux between the confluence of the upper Mississippi and Ohio Rivers and the outlet of the subbasin. Of the 136 pesticide compounds and degradates that were analyzed, only 18 were detected above the method reporting level. The 18 compounds that were detected fell into three categories: (1) compounds that were frequently detected and showed a response in concentration to the flood; (2) compounds that were detected in almost every sample at every station but at low concentrations; and (3) compounds that were infrequently detected. Fluxes for the most frequently detected pesticides having the highest concentrations (atrazine, metolachlor, acetochlor, and simazine) were within the low-to-middle range of historic fluxes. An average of 66,450 cubic feet per second of streamflow was diverted from the lower Mississippi River through the Morganza Floodway into the Atchafalaya River from May 14 through July 7, 2011. Dissolved oxygen concentrations in the floodway decreased with the amount of time that the flood control structure was open, which affected nitrate and orthophosphate concentrations. As dissolved oxygen concentrations decreased in the floodway, nitrate concentrations decreased and orthophosphate concentrations increased. Oil and gas samples were also collected at 1 station upstream and 1 station downstream from the outlet of the Morganza Floodway into the Atchafalaya River. There were no detections of petroleum hydrocarbons in the upstream or downstream samples. All concentrations of oil and grease were relatively low, and the effect of water from the floodway on water quality in the Atchafalaya River could not be determined because oil and grease samples were not collected from the floodway.

Resistivity imaging of strata and faults in Bangladesh

NASA Astrophysics Data System (ADS)

Hosain, A.; Steckler, M. S.; Akhter, S. H.

2015-12-01

The Ganges-Brahmaputra-Meghna Delta, the largest in the world, is subject to deformation by active tectonics and dynamic river systems. It lies near the juncture of the Indian, Eurasian and Burmese plates and is being overthrust by both the Shillong Massif and the Indo-Burman Ranges. There are multiple major and minor active faults in Bangladesh, many of which are buried by the sedimentation. For example, the Madhupur tract is a Pleistocene upland in the middle part of Bengal Basin. Whether it is a passive interfluve of the river system or a tilted and tectonically uplifted block has been debated for decades. The Tippera Surface, in Comilla at the eastern part of the basin, is composed of uplifted and oxidized Holocene strata and overlies buried anticlines of the Indo-Burman fold belt. Furthermore, the rivers are subject to migrations, avulsions and other changes in course. The last major avulsion of the Brahmaputra River was only ~200 years ago. During the sea level fall in the last glaciation the major rivers created large incised valleys. In much of the exposed uplands there was the development of a weathered clay surface. This now forms a clay layer separating the Pleistocene and Holocene strata in large parts of Bangladesh. We use electrical resistivity surveying and hand-drilled borehole lithological data to better understand the subsurface discontinuities and structures. The resistivity system consists of an 84 electrode array powered by 2 car batteries and is capable of imaging lithologies to ~100m depth, similar to the depths of the boreholes used to calibrate the data. We extend our previous work on the western margin of the Madhupur Tract with additional lines on the eastern flank of Madhupur. Resistivity lines along the exposed Lalmai anticline in Comilla image the now tilted Holocene-Pleistocene clay layer. Additional lines along the subsurface continuation of the anticline provide additional information on the subsurface lithologies associated with the complex interplay of fluvial dynamics and active tectonics. We will present the latest images and interpretations.

Occurrence and distribution of nutrients, suspended sediment, and pesticides in the Mobile River Basin, Alabama, Georgia, Mississippi, and Tennessee, 1999-2001

USGS Publications Warehouse

McPherson, Ann K.; Moreland, Richard S.; Atkins, J. Brian

2003-01-01

The Mobile River Basin is one of more than 50 river basins and aquifer systems being investigated as part of the U.S. Geological Survey's National Water- Quality Assessment (NAWQA) Program. This basin is the sixth largest river basin in the United States and the fourth largest in terms of streamflow. The Mobile River Basin encompasses parts of Alabama, Georgia, Mississippi, and Tennessee, and almost two-thirds of the 44,0000-square-mile basin is located in Alabama. The extensive water resources of the Mobile River Basin are influenced by an array of natural and cultural factors, which impart unique and variable qualities to the streams, rivers, and aquifers and provide abundant habitat to sustain the diverse aquatic life in the basin. From January 1999 to December 2001, a study was conducted of the occurrence and distribution of nutrients, suspended sediment, and pesticides in surface water of the Mobile River Basin. Nine sampling sites were selected on the basis of land use. The nine sites included two streams draining agricultural areas, two urban streams, and five large rivers with mixed land use. Surface-water samples were collected from one to four times each month to characterize the spatial and temporal variation in nutrient and pesticide concentrations. Nutrient and suspended-sediment concentrations were highest in watersheds dominated by urban or agricultural land uses. Forty-two percent of the total phosphorus concentrations at all nine sites exceeded the U.S. Environmental Protection Agency's recommended maximum concentration of 0.1 milligram per liter. Flow-weighted mean concentrations at the Mobile River Basin sites generally were in the lower to middle percentile ranges compared with data from other NAWQA studies across the Nation. However, flow-weighted mean concentrations of ammonia, total nitrogen, orthophosphate, and total phosphorus at Bogue Chitto Creek, an agricultural watershed, ranked in the upper 20th percentile of agricultural sites sampled across the Nation as part of the NAWQA Program. Nutrient loads in the Tombigbee River were nearly twice as high compared with nutrient loads in the Alabama River. Nutrient yields were highest in Bogue Chitto Creek, Cahaba Valley Creek, and Threemile Branch because of agricultural and urban land uses in these watersheds. Of the 104 pesticides and degradation products analyzed in the stream samples, 69 were detected in one or more samples. Of the 69 detected pesticides, 51 were herbicides, 15 were insecticides, and 3 were fungicides. A relatively small number of heavily used herbicides accounted for most of the detections, including atrazine and its metabolites (deethylatrazine, 2-hydroxyatrazine, deisopropylatrazine, and deethyldeisopropylatrazine), simazine, metolachlor, tebuthiuron, prometon, diuron, and 2,4-D. Diazinon, chlorpyrifos, and carbaryl were the most frequently detected insecticides; metalaxyl was the most frequently detected fungicide in the Mobile River Basin. Concentrations of pesticides detected in surface water of the Mobile River Basin were among the highest concentrations recorded nationally by the NAWQA Program during 1991 to 2001. The three highest concentrations of atrazine detected at sites across the country were recorded at Bogue Chitto Creek; the highest concentrations of 2,4-D, imazaquin, and malathion recorded nationally were detected at Threemile Branch. Aquatic-life criteria were exceeded by concentrations of five herbicides (2,4-D, atrazine, cyanazine, diuron, and metolachlor), six insecticides (carbaryl, chlorpyrifos, diazinon, dieldrin, malathion, and p,p'-DDE), and one fungicide (chlorothalonil). Drinking-water standards were exceeded by concentrations of four herbicides (2,4-D, atrazine, cyanazine, and simazine), three insecticides (alpha- HCH, diazinon, and dieldrin), and one fungicide (chlorothalonil). The types and concentrations of pesticides found in surface water are linked to land use and to the types of pesti

Efficient gas exchange between a boreal river and the atmosphere

NASA Astrophysics Data System (ADS)

Huotari, Jussi; Haapanala, Sami; Pumpanen, Jukka; Vesala, Timo; Ojala, Anne

2013-11-01

largest uncertainties in accurately resolving the role of rivers and streams in carbon cycling stem from difficulties in determining gas exchange between water and the atmosphere. So far, estimates for river-atmosphere gas exchange have lacked direct ecosystem-scale flux measurements not disturbing gas exchange across the air-water interface. We conducted the first direct riverine gas exchange measurements with eddy covariance in tandem with continuous surface water CO2 measurements in a large boreal river for 30 days. Our measured gas transfer velocity was, on average, 20.8 cm h-1, which is clearly higher than the model estimates based on river channel morphology and water velocity, whereas our floating chambers gave comparable values at 17.3 cm h-1. These results demonstrate that present estimates for riverine CO2 emissions are very likely too low. This result is also relevant to any other gases emitted, as their diffusive exchange rates are similarly proportional to gas transfer velocity.

Turbidity and Total Suspended Solids on the Lower Cache River Watershed, AR.

PubMed

Rosado-Berrios, Carlos A; Bouldin, Jennifer L

2016-06-01

The Cache River Watershed (CRW) in Arkansas is part of one of the largest remaining bottomland hardwood forests in the US. Although wetlands are known to improve water quality, the Cache River is listed as impaired due to sedimentation and turbidity. This study measured turbidity and total suspended solids (TSS) in seven sites of the lower CRW; six sites were located on the Bayou DeView tributary of the Cache River. Turbidity and TSS levels ranged from 1.21 to 896 NTU, and 0.17 to 386.33 mg/L respectively and had an increasing trend over the 3-year study. However, a decreasing trend from upstream to downstream in the Bayou DeView tributary was noted. Sediment loading calculated from high precipitation events and mean TSS values indicate that contributions from the Cache River main channel was approximately 6.6 times greater than contributions from Bayou DeView. Land use surrounding this river channel affects water quality as wetlands provide a filter for sediments in the Bayou DeView channel.

Recent floods in the Middle Ebro River, Spain: hydrometeorological aspects and floodplain management

NASA Astrophysics Data System (ADS)

Domenech, S.; Espejo, F.; Ollero, A.; Sánchez-Fabre, M.

2009-09-01

The Ebro River has the largest Mediterranean basin in the Iberian Peninsula and the third one by surface among those of the Mediterranean Sea. The middle stretch of this river is especially interesting because it constitutes a very economically important axis of population in a semi-arid environment context. Flooding processes are common in the Middle Ebro River, but the combination among decrease of discharges, dam construction and expansion and reinforcement of defences created an unusually quiet period as regards flooding events during the last quarter of the previous century. Nevertheless, with the turn of the century it seems that the Middle Ebro River has entered into new dynamics, with bigger and more frequent floods, the appearance of which has changed its seasonal nature. The most relevant examples are those of February 2003 and March-April 2007. The present paper examines these recent trends and discusses their possible causes from the points of view of hydro-meteorology, flood management through the use of reservoirs, and floodplain management. The consequences of recent floods in the Middle Ebro River have reopened the debate about possible risk management measures.

Geologic map of the Bernalillo NW quadrangle, Sandoval County, New Mexico

USGS Publications Warehouse

Koning, Daniel J.; Personius, Stephen F.

2002-01-01

The Bernalillo NW quadrangle is located in the northern part of the Albuquerque basin, which is the largest basin or graben within the Rio Grande rift. The quadrangle is underlain by poorly consolidated sedimentary rocks of the Santa Fe Group. These rocks are best exposed in the southwestern part of the quadrangle in the Rincones de Zia, a badland topography cut by northward-flowing tributary arroyos of the Jemez River. The Jemez River flows through the northern half of the quadrangle; extensive fluvial and eolian deposits cover bedrock units along the river. The structural fabric of the quadrangle is dominated by dozens of generally north striking, east and west-dipping normal faults and minor folds associated with the Neogene Rio Grande rift.

A stacking ensemble learning framework for annual river ice breakup dates

NASA Astrophysics Data System (ADS)

Sun, Wei; Trevor, Bernard

2018-06-01

River ice breakup dates (BDs) are not merely a proxy indicator of climate variability and change, but a direct concern in the management of local ice-caused flooding. A framework of stacking ensemble learning for annual river ice BDs was developed, which included two-level components: member and combining models. The member models described the relations between BD and their affecting indicators; the combining models linked the predicted BD by each member models with the observed BD. Especially, Bayesian regularization back-propagation artificial neural network (BRANN), and adaptive neuro fuzzy inference systems (ANFIS) were employed as both member and combining models. The candidate combining models also included the simple average methods (SAM). The input variables for member models were selected by a hybrid filter and wrapper method. The performances of these models were examined using the leave-one-out cross validation. As the largest unregulated river in Alberta, Canada with ice jams frequently occurring in the vicinity of Fort McMurray, the Athabasca River at Fort McMurray was selected as the study area. The breakup dates and candidate affecting indicators in 1980-2015 were collected. The results showed that, the BRANN member models generally outperformed the ANFIS member models in terms of better performances and simpler structures. The difference between the R and MI rankings of inputs in the optimal member models may imply that the linear correlation based filter method would be feasible to generate a range of candidate inputs for further screening through other wrapper or embedded IVS methods. The SAM and BRANN combining models generally outperformed all member models. The optimal SAM combining model combined two BRANN member models and improved upon them in terms of average squared errors by 14.6% and 18.1% respectively. In this study, for the first time, the stacking ensemble learning was applied to forecasting of river ice breakup dates, which appeared promising for other river ice forecasting problems.

Anthropogenic modifications to drainage conditions on streamflow variability in the Wabash River basin, Indiana

NASA Astrophysics Data System (ADS)

Chiu, C.; Bowling, L. C.

2011-12-01

The Wabash River watershed is the largest watershed in Indiana and includes the longest undammed river reach east of the Mississippi River. The land use of the Wabash River basin began to significantly change from mixed woodland dominated by small lakes and wetlands to agriculture in the mid-1800s and agriculture is now the predominant land use. Over 80% of natural wetland areas were drained to facilitate better crop production through both surface and subsurface drainage applications. Quantifying the change in hydrologic response in this intensively managed landscape requires a hydrologic model that can represent wetlands, crop growth, and impervious area as well as subsurface and surface drainage enhancements, coupled with high resolution soil and topographic inputs. The Variable Infiltration Capacity (VIC) model wetland algorithm has been previously modified to incorporate spatially-varying estimates of water table distribution using a topographic index approach, as well as a simple urban representation. Now, the soil water characteristics curve and a derived drained to equilibrium moisture profile are used to improve the model's estimation of the water table. In order to represent subsurface (tile) drainage, the tile drainage component of subsurface flow is calculated when the simulated water table rises above a specified drain depth. A map of the current estimated extent of subsurface tile drainage for the Wabash River based on a decision tree classifier of soil drainage class, soil slope and agricultural land use is used to activate the new tile drainage feature in the VIC model, while wetland depressional storage capacity is extracted from digital elevation and soil information. This modified VIC model is used to evaluate the performance of model physical variations in the intensively managed hydrologic regime of the Wabash River system and to understand the role of surface and subsurface storage, and land use and land cover change on hydrologic change.

Sedimentation problems in a lateral dock on the Paraná River

NASA Astrophysics Data System (ADS)

Latessa, Gaston; Sabarots Gerbec, Martin; Arecco, Pablo

2017-04-01

The Paraná River is one of the largest water courses in the world and along its reach in the Argentine territory, it receives a large load of sediments from the Pilcomayo and Bermejo Rivers, through the Paraguay River, in the upper basin at the North of Argentina and South of Bolivia. The suspended sediment load is estimated in 100 Million ton/year. This unique characteristic drives the Paraná River morphology downstream, as well as the Paraná delta morphodynamics. On top of its natural behaviour, the Paraná-Paraguay river system is an important inland waterway transport corridor, with a significant amount of sea going vessels and inland barges navigating throughout stretches of more than 3000 Km. Consequently, there are numerous port complexes and terminals along the river banks. The typical wet infrastructure of these terminals is usually composed by jetties and quay walls, and occasionally with side or lateral docks. Whereas, the case included within this study presents all these components. This study presents a hydrodynamic and sedimentology 3D model to predict the velocity fields and the associated shear stresses that will drive morphological processes in the lateral dock. The terminal layout, side dock configuration, and sedimentation issues will be analyzed from multidisciplinary point of view, under different hydrological events and considering the correlated sediment loads. Recent bathymetry studies had been carried out and this set of data will be implemented to build the domain geometry. The flow series is as well extended with the up to date gauged flows and levels, to carry out statistical analysis and identify the design flows for different probabilities. The main objective of this analysis will be to understand and identify the scour and deposition processes and the possible problems to the structures safety and the operation of the docks, and introduce variations to the baseline design, if necessary. Results will be contrasted and validated with empirical formulae and criteria.

Three Gorges Dam alters the Changjiang (Yangtze) river water cycle in the dry seasons: Evidence from H-O isotopes.

PubMed

Deng, Kai; Yang, Shouye; Lian, Ergang; Li, Chao; Yang, Chengfan; Wei, Hailun

2016-08-15

As the largest hydropower project in the world, the Three Gorges Dam (TGD) has attracted great concerns in terms of its impact on the Changjiang (Yangtze) River and coastal marine environments. In this study, we measured or collected the H-O isotopic data of river water, groundwater and precipitation in the mid-lower Changjiang catchment during the dry seasons of recent years. The aim was to investigate the changes of river water cycle in response to the impoundment of the TGD. Isotopic evidences suggested that the mid-lower Changjiang river water was ultimately derived from precipitation, but dominated by the mixing of different water masses with variable sources and isotopic signals as well. The isotopic parameter "deuterium excess" (d-excess) yielded large fluctuations along the mid-lower mainstream during the initial stage of the TGD impoundment, which was inherited from the upstream water with inhomogeneous isotopic signals. However, as the reservoir water level rising to the present stage, small variability of d-excess was observed along the mid-lower mainstream. This discrepancy could be explained that the TGD impoundment had significantly altered the water cycle downstream the dam, with the rising water level increasing the residence time and enhancing the mixing of reservoir water derived from upstream. This eventually resulted in the homogenization of reservoir water, and thus small fluctuations of d-excess downstream the dam after the quasi-normal stage (2008 to present). We infer that the retention effect of large reservoirs has greatly buffered the d-excess natural variability of water cycle in large river systems. Nevertheless, more research attention has to be paid to the damming effect on the water cycle in the river, estuarine and coastal areas, especially during the dry seasons. Copyright © 2016 Elsevier B.V. All rights reserved.

Recent changes of sediment flux to the western Pacific Ocean from major rivers in East and Southeast Asia

NASA Astrophysics Data System (ADS)

Wang, Houjie; Saito, Yoshiki; Zhang, Yong; Bi, Naishuang; Sun, Xiaoxiao; Yang, Zuosheng

2011-09-01

The five largest rivers in East and Southeast Asia (Yellow, Yangtze, Pearl, Red and Mekong) are important contributors of terrigenous sediment to the western Pacific Ocean. Although they have annually delivered ~ 2000 × 10 9 kg of sediment to the ocean since 1000 yr BP, they presently contribute only ~ 600 × 10 9 kg/yr, which is reverting to a level typical of the relatively undisturbed watersheds before the rise in human activities in East and Southeast Asia at 2000 yr BP. During the most recent decades flow regulation by dams and sediment entrapment by reservoirs, as well as human-influenced soil erosion in the river basins, have sharply reduced the sediment delivered from the large river basins to the ocean. We constructed a time series of data on annual water discharges and sediment fluxes from these large rivers to the western Pacific Ocean covering the period 1950-2008. These data indicate that the short-term (interannual scale) variation of sediment flux is dominated by natural climatic oscillations such as the El Niño/La Niña cycle and that anthropogenic causes involving dams and land use control the long-term (decadal scale) decrease in sediment flux to the ocean. In contrast to the relatively slow historical increase in sediment flux during the period 2000-1000 yr BP, the recent sediment flux has been decreased at an accelerating rate over centennial scales. The alterations of these large river systems by both natural and anthropogenic forcing present severe environmental challenges in the coastal ocean, including the sinking of deltas and declines in coastal wetland areas due to the decreasing sediment supply. Our work thus provides a regional perspective on the large river-derived sediment flux to the ocean over millennial and decadal scales, which will be important for understanding and managing the present and future trends of delivery of terrigenous sediment to the ocean in the context of global change.

[Changes of wetland landscape pattern in Dayang River Estuary based on high-resolution remote sensing image].

PubMed

Wu, Tao; Zhao, Dong-zhi; Zhang, Feng-shou; Wei, Bao-quan

2011-07-01

Based on the comprehensive consideration of the high resolution characteristics of remote sensing data and the current situation of land cover and land use in Dayang River Estuary wetland, a classification system with different resolutions of wetland landscape in the Estuary was established. The landscape pattern indices and landscape transition matrix were calculated by using the high resolution remote sensing data, and the dynamic changes of the landscape pattern from 1984 to 2008 were analyzed. In the study period, the wetland landscape components changed drastically. Wetland landscape transferred from natural wetland into artificial wetland, and wetland core regional area decreased. Natural wetland's largest patch area index descended, and the fragmentation degree ascended; while artificial wetland area expanded, its patch number decreased, polymerization degree increased, and the maximum patch area index had an obvious increasing trend. Increasing human activities, embankment construction, and reclamation for aquaculture were the main causes for the decrease of wetland area and the degradation of the ecological functions of Dayang River Estuary. To constitute long-term scientific and reasonable development plan, establish wetland nature reserves, protect riverway, draft strict inspective regimes for aquaculture reclamation, and energetically develop resource-based tourism industry would be the main strategies for the protection of the estuarine wetland.

National Smart Water Grid

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

Beaulieu, R A

The United States repeatedly experiences floods along the Midwest's large rivers and droughts in the arid Western States that cause traumatic environmental conditions with huge economic impact. With an integrated approach and solution these problems can be alleviated. Tapping into the Mississippi River and its tributaries, the world's third largest fresh water river system, during flood events will mitigate the damage of flooding and provide a new source of fresh water to the Western States. The trend of increased flooding on the Midwest's large rivers is supported by a growing body of scientific literature. The Colorado River Basin and themore » western states are experiencing a protracted multi-year drought. Fresh water can be pumped via pipelines from areas of overabundance/flood to areas of drought or high demand. Calculations document 10 to 60 million acre-feet (maf) of fresh water per flood event can be captured from the Midwest's Rivers and pumped via pipelines to the Colorado River and introduced upstream of Lake Powell, Utah, to destinations near Denver, Colorado, and used in areas along the pipelines. Water users of the Colorado River include the cities in southern Nevada, southern California, northern Arizona, Colorado, Utah, Indian Tribes, and Mexico. The proposed start and end points, and routes of the pipelines are documented, including information on right-of-ways necessary for state and federal permits. A National Smart Water Grid{trademark} (NSWG) Project will create thousands of new jobs for construction, operation, and maintenance and save billions in drought and flood damage reparations tax dollars. The socio-economic benefits of NWSG include decreased flooding in the Midwest; increased agriculture, and recreation and tourism; improved national security, transportation, and fishery and wildlife habitats; mitigated regional climate change and global warming such as increased carbon capture; decreased salinity in Colorado River water crossing the US-Mexico border; and decreased eutrophication (excessive plant growth and decay) in the Gulf of Mexico to name a few. The National Smart Water Grid{trademark} will pay for itself in a single major flood event.« less

Groundwater quality in the Colorado River basins, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Four groundwater basins along the Colorado River make up one of the study areas being evaluated. The Colorado River study area is approximately 884 square miles (2,290 square kilometers) and includes the Needles, Palo Verde Mesa, Palo Verde Valley, and Yuma groundwater basins (California Department of Water Resources, 2003). The Colorado River study area has an arid climate and is part of the Sonoran Desert. Average annual rainfall is about 3 inches (8 centimeters). Land use in the study area is approximately 47 percent (%) natural (mostly shrubland), 47% agricultural, and 6% urban. The primary crops are pasture and hay. The largest urban area is the city of Blythe (2010 population of 21,000). Groundwater in these basins is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay deposited by the Colorado River or derived from surrounding mountains. The primary aquifers in the Colorado River study area are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in the Colorado River basins are completed to depths between 230 and 460 feet (70 to 140 meters), consist of solid casing from the land surface to a depth of 130 of 390 feet (39 to 119 meters), and are screened or perforated below the solid casing. The main source of recharge to the groundwater systems in the Needles, Palo Verde Mesa, and Palo Verde Valley basins is the Colorado River; in the Yuma basin, the main source of recharge is from subsurface flow from the groundwater basins to the west. Groundwater discharge is primarily to pumping wells, evapotranspiration, and, locally, to the Colorado River.

High Resolution Modelling of the Congo River's Multi-Threaded Main Stem Hydraulics

NASA Astrophysics Data System (ADS)

Carr, A. B.; Trigg, M.; Tshimanga, R.; Neal, J. C.; Borman, D.; Smith, M. W.; Bola, G.; Kabuya, P.; Mushie, C. A.; Tschumbu, C. L.

2017-12-01

We present the results of a summer 2017 field campaign by members of the Congo River users Hydraulics and Morphology (CRuHM) project, and a subsequent reach-scale hydraulic modelling study on the Congo's main stem. Sonar bathymetry, ADCP transects, and water surface elevation data have been collected along the Congo's heavily multi-threaded middle reach, which exhibits complex in-channel hydraulic processes that are not well understood. To model the entire basin's hydrodynamics, these in-channel hydraulic processes must be parameterised since it is not computationally feasible to represent them explicitly. Furthermore, recent research suggests that relative to other large global rivers, in-channel flows on the Congo represent a relatively large proportion of total flow through the river-floodplain system. We therefore regard sufficient representation of in-channel hydraulic processes as a Congo River hydrodynamic research priority. To enable explicit representation of in-channel hydraulics, we develop a reach-scale (70 km), high resolution hydraulic model. Simulation of flow through individual channel threads provides new information on flow depths and velocities, and will be used to inform the parameterisation of a broader basin-scale hydrodynamic model. The basin-scale model will ultimately be used to investigate floodplain fluxes, flood wave attenuation, and the impact of future hydrological change scenarios on basin hydrodynamics. This presentation will focus on the methodology we use to develop a reach-scale bathymetric DEM. The bathymetry of only a small proportion of channel threads can realistically be captured, necessitating some estimation of the bathymetry of channels not surveyed. We explore different approaches to this bathymetry estimation, and the extent to which it influences hydraulic model predictions. The CRuHM project is a consortium comprising the Universities of Kinshasa, Rhodes, Dar es Salaam, Bristol, and Leeds, and is funded by Royal Society-DFID Africa Capacity Building Initiative. The project aims to strengthen institutional research capacity and advance our understanding of the hydrology, hydrodynamics and sediment dynamics of the world's second largest river system through fieldwork and development of numerical models.

Klamath River Basin water-quality data

USGS Publications Warehouse

Smith, Cassandra D.; Rounds, Stewart A.; Orzol, Leonard L.; Sobieszczyk, Steven

2018-05-29

The Klamath River Basin stretches from the mountains and inland basins of south-central Oregon and northern California to the Pacific Ocean, spanning multiple climatic regions and encompassing a variety of ecosystems. Water quantity and water quality are important topics in the basin, because water is a critical resource for farming and municipal use, power generation, and for the support of wildlife, aquatic ecosystems, and endangered species. Upper Klamath Lake is the largest freshwater lake in Oregon (112 square miles) and is known for its seasonal algal blooms. The Klamath River has dams for hydropower and the upper basin requires irrigation water to support agriculture and grazing. Multiple species of endangered fish inhabit the rivers and lakes, and the marshes are key stops on the Pacific flyway for migrating birds. For these and other reasons, the water resources in this basin have been studied and monitored to support their management distribution.

A field study of the confluence between Negro and Solimões Rivers. Part 2: Bed morphology and stratigraphy

NASA Astrophysics Data System (ADS)

Ianniruberto, Marco; Trevethan, Mark; Pinheiro, Arthur; Andrade, Joao Fernando; Dantas, Elton; Filizola, Naziano; Santos, André; Gualtieri, Carlo

2018-01-01

The confluence of the Negro and Solimões Rivers is an interesting study area under several points of view: it represents the second largest river confluence of the Amazon Basin; the rivers are characterized by very distinct hydrologic behaviour; and it is situated in a peculiar tectonic setting. A field investigation was undertaken to study the characteristics of this confluence, aiming to better understand the bed morphology and stratigraphy resulting from the complex interaction of geological setting, hydrodynamics, and sediment load. Two field campaigns were carried out, during low- and high-flow conditions, using high-resolution seismic, echosounding, and acoustic Doppler current profiling. A third campaign was carried out just in a limited area of the confluence, with a multi-beam echosounder. The results of these surveys provided a more detailed view of the geology, morphology and sediment distribution about the confluence.

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.

Baseline studies in the Elwha River ecosystem prior to dam removal: Introduction to the special issue

USGS Publications Warehouse

Duda, Jeffrey J.; Freilich, Jerry; Schreiner, Edward G.

2008-01-01

The planned removal of two dams that have been in place for over 95 years on the Elwha River provides a unique opportunity to study dam removal effects. Among the largest dams ever considered for removal, this project is compelling because 83% of the watershed lies undisturbed in Olympic National Park. Eighteen million cubic meters of sediment have accumulated in and will be released from the reservoirs, and there is potential for rehabilitating depressed Pacific salmon runs. Researchers from academia, non-profit organizations, federal and state governments, and the Lower Elwha Klallam Tribe are currently assessing baseline ecological conditions of the Elwha River as part of dam removal studies. We introduce dam removal topics, provide a brief history of the dams, and summarize the ecology of the Elwha River basin as an introduction to a special issue devoted to research in the watershed.

Oil shale and nahcolite resources of the Piceance Basin, Colorado

USGS Publications Warehouse

,

2010-01-01

This report presents an in-place assessment of the oil shale and nahcolite resources of the Green River Formation in the Piceance Basin of western Colorado. The Piceance Basin is one of three large structural and sedimentary basins that contain vast amounts of oil shale resources in the Green River Formation of Eocene age. The other two basins, the Uinta Basin of eastern Utah and westernmost Colorado, and the Greater Green River Basin of southwest Wyoming, northwestern Colorado, and northeastern Utah also contain large resources of oil shale in the Green River Formation, and these two basins will be assessed separately. Estimated in-place oil is about 1.5 trillion barrels, based on Fischer a ssay results from boreholes drilled to evaluate oil shale, making it the largest oil shale deposit in the world. The estimated in-place nahcolite resource is about 43.3 billion short tons.

Basic cytogenetics and physical mapping of 5S and 18S ribosomal genes in Hoplias malabaricus (Osteichthyes, Characiformes, Erythrinidae) from isolated natural lagoons: a conserved karyomorph along the Iguaçu river basin.

PubMed

Gemi, Gisele; Lui, Roberto Laridondo; Treco, Fernando Rodrigo; Paiz, Leonardo Marcel; Moresco, Rafaela Maria; Margarido, Vladimir Pavan

2014-01-01

Erythrinidae include Neotropical teleost fish that are widely distributed in South America. Hoplias Gill, 1903 include two large groups: H. malabaricus Bloch, 1794 and H. lacerdae Miranda Ribeiro, 1908. Hoplias malabaricus is characterized by remarkable karyotype diversity, with some karyomorphs widely distributed geographically while others are more restricted to certain river basins. Cytogenetic analyzes were performed in a population of Hoplias malabaricus from the Wildlife Refuge of Campos de Palmas, the Iguaçu River basin. The specimens showed diploid number of 42 chromosomes (24m+18sm) without differentiated sex chromosomes system. The impregnation by silver nitrate showed multiple AgNORs. Seven pairs (4, 7, 10, 13, 16, 20 and 21) carrying 18S rDNA were detected by FISH. Heterochromatin was verified in the centromeric and pericentromeric region of most chromosomes and the terminal region of some pairs. FISH with 5S rDNA probes showed two chromosome pairs carrying these sites in the interstitial region (8 and 14). The data obtained in this study are similar to those found for two other populations of H. malabaricus already studied in the basin of the Iguaçu River, confirming the hypothesis that this species is natural, not having been introduced, as well as having an intrinsic characteristic, such as the largest number of sites of 18S rDNA.

Automated Mapping of Flood Events in the Mississippi River Basin Utilizing NASA Earth Observations

NASA Technical Reports Server (NTRS)

Bartkovich, Mercedes; Baldwin-Zook, Helen Blue; Cruz, Dashiell; McVey, Nicholas; Ploetz, Chris; Callaway, Olivia

2017-01-01

The Mississippi River Basin is the fourth largest drainage basin in the world, and is susceptible to multi-level flood events caused by heavy precipitation, snow melt, and changes in water table levels. Conducting flood analysis during periods of disaster is a challenging endeavor for NASA's Short-term Prediction Research and Transition Center (SPoRT), Federal Emergency Management Agency (FEMA), and the U.S. Geological Survey's Hazards Data Distribution Systems (USGS HDDS) due to heavily-involved research and lack of manpower. During this project, an automated script was generated that performs high-level flood analysis to relieve the workload for end-users. The script incorporated Landsat 8 Operational Land Imager (OLI) tiles and utilized computer-learning techniques to generate accurate water extent maps. The script referenced the Moderate Resolution Imaging Spectroradiometer (MODIS) land-water mask to isolate areas of flood induced waters. These areas were overlaid onto the National Land Cover Database's (NLCD) land cover data, the Oak Ridge National Laboratory's LandScan data, and Homeland Infrastructure Foundation-Level Data (HIFLD) to determine the classification of areas impacted and the population density affected by flooding. The automated algorithm was initially tested on the September 2016 flood event that occurred in Upper Mississippi River Basin, and was then further tested on multiple flood events within the Mississippi River Basin. This script allows end users to create their own flood probability and impact maps for disaster mitigation and recovery efforts.

Examining Reservoir Influences on Fluvial Sediment Supply to Estuaries and Coastal Oceans with Sediment Geochronologies: Example from Conowingo Reservoir (Upper Chesapeake Bay, USA)

NASA Astrophysics Data System (ADS)

Palinkas, C. M.; Russ, E.

2016-12-01

The flux of fluvial sediment to estuaries and coastal oceans is often interrupted by natural and anthropogenic influences. Here, we focus on river dams, which alter the connection between rivers and their receiving basins via sediment sequestration in their reservoirs. Sediments are effectively trapped until river discharge is high enough to create flow velocities capable of resuspending sediment. Sediment resuspension often varies within the reservoir, driven by morphological features such as channels and islands. Thus, sediment residence times in the reservoir are often highly variable in space and time. This study focuses on reading the sedimentary record in one such system - the reservoir upstream of Conowingo Dam, built in the late 1920s and the last and largest dam on the Susquehanna River (Maryland, USA) before it enters Chesapeake Bay. This study establishes geochronologies of reservoir sedimentation on seasonal to decadal time scales with a variety of techniques (e.g., natural and anthropogenic radioisotopes (7Be, 210Pb, 137Cs), coal from mining in the watershed) to interpret observed down-core sedimentary structures and characteristics (grain size, organic content). These observations reveal spatial and temporal patterns of sediment deposition and/or erosion. Placed within the broader context of reservoir geomorphology, these results can improve predictions of sediment supply to downstream environments, in this case Chesapeake Bay, where it can impact water quality and/or benthic organisms.

Surface-water salinity in the Gunnison River Basin, Colorado, water years 1989 through 2007

USGS Publications Warehouse

Schaffrath, Keelin R.

2012-01-01

Elevated levels of dissolved solids in water (salinity) can result in numerous and costly issues for agricultural, industrial, and municipal water users. The Colorado River Basin Salinity Control Act of 1974 (Public Law 93-320) authorized planning and construction of salinity-control projects in the Colorado River Basin. One of the first projects was the Lower Gunnison Unit, a project to mitigate salinity in the Lower Gunnison and Uncompahgre River Basins. In cooperation with the Bureau of Reclamation (USBR), the U.S. Geological Survey conducted a study to quantify changes in salinity in the Gunnison River Basin. Trends in salinity concentration and load during the period water years (WY) 1989 through 2004 (1989-2004) were determined for 15 selected streamflow-gaging stations in the Gunnison River Basin. Additionally, trends in salinity concentration and load during the period WY1989 through 2007 (1989-2007) were determined for 5 of the 15 sites for which sufficient data were available. Trend results also were used to identify regions in the Lower Gunnison River Basin (downstream from the Gunnison Tunnel) where the largest changes in salinity loads occur. Additional sources of salinity, including residential development (urbanization), changes in land cover, and natural sources, were estimated within the context of the trend results. The trend results and salinity loads estimated from trends testing also were compared to USBR and Natural Resources Conservation Service (NRCS) estimates of off-farm and on-farm salinity reduction from salinity-control projects in the basin. Finally, salinity from six additional sites in basins that are not affected by irrigated agriculture or urbanization was monitored from WY 2008 to 2010 to quantify what portion of salinity may be from nonagricultural or natural sources. In the Upper Gunnison area, which refers to Gunnison River Basin above the site located on the Gunnison River below the Gunnison Tunnel, estimated mean annual salinity load was 110,000 tons during WY 1989-2004. Analysis of both study periods (WY 1989-2004 and WY 1989-2007) showed an initial decrease in salinity load with a minimum in 1997. The net change over either study period was only significant during WY 1989-2007. Salinity load significantly decreased at the Gunnison River near Delta by 179,000 tons during WY 1989-2004. Just downstream, the Uncompahgre River enters the Gunnison River where there also was a highly significant decrease in salinity load of 55,500 tons. The site that is located at the mouth of the study area is the Gunnison River near Grand Junction where the decrease was the largest. Salinity loads decreased by 247,000 tons during WY 1989-2004 at this site though the decrease attenuated by 2007 and the net change was a decrease of 207,000 tons. The trend results presented in this study indicate that the effect of urbanization on salinity loads is difficult to discern from the effects of irrigated agriculture and that natural sources contribute a fraction of the total salinity load for the entire basin. Based on the calculated yields and geology, 23-63 percent of the estimated annual salinity load was from natural sources at the Gunnison River near Grand Junction during WY 1989-2007. The largest changes in salinity load occurred at the Gunnison River near Grand Junction as well as the two sites located in Delta: the Gunnison River at Delta and the Uncompahgre River at Delta. Those three sites, especially the two sites at Delta, were the most affected by irrigated agriculture, which was observed in the estimated mean annual loads. Irrigated acreage, especially acreage underlain by Mancos Shale, is the target of salinity-control projects intended to decrease salinity loads. The NRCS and the USBR have done the majority of salinity control work in the Lower Gunnison area of the Gunnison River Basin, and the focus has been in the Uncompahgre River Basin and in portions of the Lower Gunnison River Basin (downstream from the Gunnison Tunnel). According to the estimates from the USBR and NRCS, salinity-control projects may be responsible for a reduction of 117,300 tons of salinity as of 2004 and 142,000 tons as of 2007 at the Gunnison River near Grand Junction, Colo. (streamflow-gaging station 09152500). USBR and NRCS estimates account for all but 130,000 tons in 2004 and 65,000 tons in 2007 of salinity load reduction. The additional reduction could be a reduction in natural salt loading to the streams because of land-cover changes during the study period. It is possible also that the USBR and NRCS have underestimated changes in salinity loads as a result of the implementation of salinity-control projects.

Modeling suspended sediment sources and transport in the Ishikari River basin, Japan, using SPARROW

NASA Astrophysics Data System (ADS)

Duan, W. L.; He, B.; Takara, K.; Luo, P. P.; Nover, D.; Hu, M. C.

2015-03-01

It is important to understand the mechanisms that control the fate and transport of suspended sediment (SS) in rivers, because high suspended sediment loads have significant impacts on riverine hydroecology. In this study, the SPARROW (SPAtially Referenced Regression on Watershed Attributes) watershed model was applied to estimate the sources and transport of SS in surface waters of the Ishikari River basin (14 330 km2), the largest watershed in Hokkaido, Japan. The final developed SPARROW model has four source variables (developing lands, forest lands, agricultural lands, and stream channels), three landscape delivery variables (slope, soil permeability, and precipitation), two in-stream loss coefficients, including small streams (streams with drainage area < 200 km2) and large streams, and reservoir attenuation. The model was calibrated using measurements of SS from 31 monitoring sites of mixed spatial data on topography, soils and stream hydrography. Calibration results explain approximately 96% (R2) of the spatial variability in the natural logarithm mean annual SS flux (kg yr-1) and display relatively small prediction errors at the 31 monitoring stations. Results show that developing land is associated with the largest sediment yield at around 1006 kg km-2 yr-1, followed by agricultural land (234 kg km-2 yr-1). Estimation of incremental yields shows that 35% comes from agricultural lands, 23% from forested lands, 23% from developing lands, and 19% from stream channels. The results of this study improve our understanding of sediment production and transportation in the Ishikari River basin in general, which will benefit both the scientific and management communities in safeguarding water resources.

A 25-Year Retrospective Analysis of River Nitrogen Fluxes in the Atchafalaya

NASA Astrophysics Data System (ADS)

Xu, Y.

2005-05-01

Nitrogen enrichment from the upper Mississippi River Basin has been attributed to be the major cause for the hypoxia in the Northern Gulf of Mexico. The hypoxia threatens not only the aquatic ecosystem health but Louisiana's fishery industry directly among other problems. Although fresh water diversion from the lower Mississippi River into the region's wetlands has been considered an alternative means for reducing nitrogen loading, it is largely uncertain how much nitrogen can actually be retained from the overflowing waters in these natural wetlands. Generally, there is a knowledge gap in what tools are available for accurate assessment of nitrogen inflow, outflow and removal potential for the complex and diverse coastal floodplain systems. This study is to seek answers to three critical questions: (1) Does the Atchafalaya River Swamp remove a significant amount of nitrogen from the overflowing water or release more nitrogen into the Gulf than removing it? (2) How seasonally and annually do the nitrogen removal or release rates fluctuate? (3) What are the relationships between the nitrogen removal capacity and the basin's hydrologic conditions such as river stage and discharge? By utilizing river's long-term discharge and water quality data (1978-2002), monthly and annual nitrogen fluxes were quantified, and their relationships with the basin's hydrologic conditions were investigated. A total Kjeldahl nitrogen (TKN) mass input-output balance between the upstream (Simmesport) and downstream (Morgan City and Wax Lake Outlet) locations was established to examine the organic nitrogen removal potential for this largest freshwater swamp basin in North America. The results showed that on average, TKN input into the Atchafalaya was 200,323 Mg yr-1 and TKN output leaving the basin was 145,917 Mg yr-1, resulting in a 27% removal rate of nitrogen. Monthly nitrogen input and output in the basin were highest from March to June (input vs. output: 25,000 vs. 18,000 Mg mon-1) and lowest from August to November (8,000 vs. 6,000 Mg mon-1). There was a large variation in both annual and inter-annual nitrogen removals, and the variability was positively correlated with the amount of inflow water at Simmesport. However, no close relationship between the river inflow and percentage nitrogen removal rate was found. The results gained from this study suggest that regulating the river's inflow will help reduce nitrogen loading of the Mississippi River to the Gulf of Mexico. The in-stream loss of nitrogen indicates that previous studies may have overestimated nitrogen discharge from the Mississippi-Atchafalaya River system. Furthermore, the study found that knowledge on spatial hydrological conditions in the basin is needed to understand nitrogen dynamics in the Atchafalaya River Swamp.

Non-agricultural ammonia emissions in urban China

NASA Astrophysics Data System (ADS)

Chang, Y. H.

2014-03-01

The non-agricultural ammonia (NH3) emissions in cities have received little attention but could rival agricultural sources in term of the efficiency in PM formation. The starting point for finding credible solutions is to comprehensively establish a city-specific Non-agricultural Ammonia Emission Inventory (NAEI) and identify the largest sources where efforts can be directed to deliver the largest impact. In this paper, I present a NAEI of 113 national key cities targeted on environmental protection in China in 2010, which for the first time covers NH3 emissions from pets, infants, smokers, green land, and household products. Results show that totally 210 478 Mg, the NH3 emissions from traffic, fuel combustion, waste disposal, pets, green land, human, and household products are 67 671 Mg, 56 275 Mg, 44 289 Mg, 23 355 Mg, 7509 Mg, 7312 Mg, and 4069 Mg, respectively. The NH3 emission intensity from the municipal districts ranges from 0.08 to 3.13 Mg km-2 yr-1, with a average of 0.84 Mg km-2 yr-1. The high NH3 emission intensities in Beijing-Tianjin-Hebei region, Yangtze River Delta region and Pearl River Delta region support the view that non-agricultural NH3 sources play a key role in city-scale NH3 emissions and thus have potentially important implications for secondary PM formation (ammonium-sulfate-nitrate system) in urban agglomeration of China. Therefore, in addition to current SO2 and NOx controls, China also needs to allocate more scientific, technical, and legal resources on controlling non-agricultural NH3 emissions in the future.

The Morphology and Sedimentology of Fluvial Megascours

NASA Astrophysics Data System (ADS)

Bull, J. M.; Vardy, M. E.; Sambrook Smith, G.; Best, J.; Dixon, S. J.; Goodbred, S. L., Jr.

2015-12-01

Scour zones in the World's largest rivers, or so-called "megascours", are extensive and dynamic features that are currently poorly understood in terms of their morphology and kinematics. Such scours can erode c. 50-60 metres below the water surface, extend laterally for 100s metres to kilometres, and may migrate kilometres in a single year. Understanding the evolution of such scour zones has important implications for improved flood and bank erosion prediction, better infrastructure planning (e.g. bridges, embankments), and differentiating between autocyclic and allocyclic erosion in the geological record (e.g. sequence stratigraphic applications). Here, we present results from two field seasons using geophysical techniques (high-resolution multibeam bathymetry and seismic reflection data using Chirp and Boomer sources) to study six scour zones in the Ganges-Jamuna-Padma-Meghna river system of Bangladesh. These scours include some of the World's largest confluences, as well as smaller distributaries, and those with varying levels of tidal influence. Seismic data from repeat surveys permit an accurate characterization of short-term scour evolution and associated deposits across two monsoonal flood peaks. Meanwhile, the bathymetric data reveals widespread deep scours (30-40 m) even in small, downstream distributary tidal channels, illustrating that megascours are present all the way to the subaerial delta fringe. Bathymetric analysis also shows a complex relationship between these scours and bedform distribution and orientation. This suggests the need for a new scaling for sand dune dimensions at such sites, and the need for substantial revisions to current ideas on the use of dune-scale cross-stratification to infer palaeoflow depths in the ancient sedimentary record.

Riverine based eco-tourism: Trinity River non-market benefits estimates

USGS Publications Warehouse

Douglas, A.J.; Taylor, J.G.

1998-01-01

California's Central Valley Project (CVP) was approved by voters in a statewide referendum in 1933. CVP referendum approval initiated funding for construction of important water development projects that had far reaching effects on regional water supplies. The construction of Trinity Dam in 1963 and the subsequent transbasin diversion of Trinity River flow was one of several CVP projects that had noteworthy adverse environmental and regional economic impacts. The Trinity River is the largest tributary of the Klamath River, and has its headwaters in the Trinity Alps of north-central California. After the construction of Trinity Dam in 1963, 90% of the Trinity River flow at Lewiston was moved to the Sacramento River via the Clear Creek Tunnel. Before 1963, the Trinity River was a major recreation resource of Northern California. The loss of streamflow has had a marked adverse impact on Trinity River-related recreation activities and the size and robustness of Trinity River salmon, steelhead, shad, and sturgeon runs. Trinity River water produces hydropower during its transit via Bureau of Reclamation canals and pumps to the northern San Joaquin Valley, where it is used for irrigated agriculture. The benefits provided by Trinity River instream flow-related environmental amenities were estimated with the travel cost method (TCM). Trinity River non-market benefits are about $406 million per annum, while the social cost of sending water down the Trinity River ranges from $17 to $42 million per annum, depending on the exact flow. We also discuss the relative magnitude of Trinity River survey data contingent value method (CVM) benefits estimates.

2013 Gulf of Mexico Hypoxia Forecast

USGS Publications Warehouse

Scavia, Donald; Evans, Mary Anne; Obenour, Dan

2013-01-01

The Gulf of Mexico annual summer hypoxia forecasts are based on average May total nitrogen loads from the Mississippi River basin for that year. The load estimate, recently released by USGS, is 7,316 metric tons per day. Based on that estimate, we predict the area of this summer’s hypoxic zone to be 18,900 square kilometers (95% credible interval, 13,400 to 24,200), the 7th largest reported and about the size of New Jersey. Our forecast hypoxic volume is 74.5 km3 (95% credible interval, 51.5 to 97.0), also the 7th largest on record.

Reviews and syntheses: Anthropogenic perturbations to carbon fluxes in Asian river systems - concepts, emerging trends, and research challenges

NASA Astrophysics Data System (ADS)

Park, Ji-Hyung; Nayna, Omme K.; Begum, Most S.; Chea, Eliyan; Hartmann, Jens; Keil, Richard G.; Kumar, Sanjeev; Lu, Xixi; Ran, Lishan; Richey, Jeffrey E.; Sarma, Vedula V. S. S.; Tareq, Shafi M.; Xuan, Do Thi; Yu, Ruihong

2018-05-01

Human activities are drastically altering water and material flows in river systems across Asia. These anthropogenic perturbations have rarely been linked to the carbon (C) fluxes of Asian rivers that may account for up to 40-50 % of the global fluxes. This review aims to provide a conceptual framework for assessing the human impacts on Asian river C fluxes, along with an update on anthropogenic alterations of riverine C fluxes. Drawing on case studies conducted in three selected rivers (the Ganges, Mekong, and Yellow River) and other major Asian rivers, the review focuses on the impacts of river impoundment and pollution on CO2 outgassing from the rivers draining South, Southeast, and East Asian regions that account for the largest fraction of river discharge and C exports from Asia and Oceania. A critical examination of major conceptual models of riverine processes against observed trends suggests that to better understand altered metabolisms and C fluxes in anthropogenic land-water-scapes, or riverine landscapes modified by human activities, the traditional view of the river continuum should be complemented with concepts addressing spatial and temporal discontinuities created by human activities, such as river impoundment and pollution. Recent booms in dam construction on many large Asian rivers pose a host of environmental problems, including increased retention of sediment and associated C. A small number of studies that measured greenhouse gas (GHG) emissions in dammed Asian rivers have reported contrasting impoundment effects: decreased GHG emissions from eutrophic reservoirs with enhanced primary production vs. increased emissions from the flooded vegetation and soils in the early years following dam construction or from the impounded reaches and downstream estuaries during the monsoon period. These contrasting results suggest that the rates of metabolic processes in the impounded and downstream reaches can vary greatly longitudinally over time as a combined result of diel shifts in the balance between autotrophy and heterotrophy, seasonal fluctuations between dry and monsoon periods, and a long-term change from a leaky post-construction phase to a gradual C sink. The rapid pace of urbanization across southern and eastern Asian regions has dramatically increased municipal water withdrawal, generating annually 120 km3 of wastewater in 24 countries, which comprises 39 % of the global municipal wastewater production. Although municipal wastewater constitutes only 1 % of the renewable surface water, it can disproportionately affect the receiving river water, particularly downstream of rapidly expanding metropolitan areas, resulting in eutrophication, increases in the amount and lability of organic C, and pulse emissions of CO2 and other GHGs. In rivers draining highly populated metropolitan areas, lower reaches and tributaries, which are often plagued by frequent algal blooms and pulsatile CO2 emissions from urban tributaries delivering high loads of wastewater, tended to exhibit higher levels of organic C and the partial pressure of CO2 (pCO2) than less impacted upstream reaches and eutrophic impounded reaches. More field measurements of pCO2, together with accurate flux calculations based on river-specific model parameters, are required to provide more accurate estimates of GHG emissions from the Asian rivers that are now underrepresented in the global C budgets. The new conceptual framework incorporating discontinuities created by impoundment and pollution into the river continuum needs to be tested with more field measurements of riverine metabolisms and CO2 dynamics across variously affected reaches to better constrain altered fluxes of organic C and CO2 resulting from changes in the balance between autotrophy and heterotrophy in increasingly human-modified river systems across Asia and other continents.

Nitrogen dynamics in the tidal freshwater Potomac River, Maryland and Virginia, water years 1979-81

USGS Publications Warehouse

Shultz, David J.

1989-01-01

On an annual basis, river-supplied nitrate is the predominant form of nitrogen supplied to the tidal Potomac River from external sources. Much of the nitrate is associated with high flows that have rapid transit times through the tidal river. The Blue Plains Sewage-Treatment Plant (STP) at Washington, D.C., is the greatest source of all nitrogen species during low-flow periods. Prior to the fall of 1980, ammonia concentrations in depth-integrated, composited water samples were greatest (more than 1.00 mg/L (milligram per liter) as nitrogen) during summer periods near Alexandria, Va., because of loading from the nearby Blue Plains STP and reduced river discharge. After the fall of 1980, initiation of advanced wastewater treatment at the Blue Plains STP reduced ammonia loading to the river by 90 percent and increased nitrate loading by a similar percentage. As a result, concentrations of ammonia during the 1981 low-flow period were less than 0.20 mg/L as nitrogen at Alexandria, while nitrate concentrations were greater than 1.50 mg/L as nitrogen. Concentrations of ammonia and nitrate at Alexandria were shown to be reasonably predictable by use of a simple dilution model that considers only loading from Chain Bridge and the Blue Plains STP. This apparently is the result of the short residence time through the Chain Bridge-to-Alexandria section of the tidal Potomac River, which precludes significant biological alterations. In marked contrast, the residence times of water parcels in the tidal Potomac River from Alexandria to Quantico, Va., are much greater because of the geometry of the reach. Biological nitrogen-cycle transformation processes affect nitrogen-species concentrations to a greater extent in this reach, especially during summer low-flow periods. Mass-balance calculations that separate changes in transport mass from biological transformations indicatethat the tidal Potomac River was a net sink for all the nitrogen constituents during the 1980 and 1981 summer low-flow periods. However, during the 1980-81 winter period, some ammonia and nitrate was transported out of the tidal Potomac River into the transition zone. Despite the reduced availability of ammonia, nitrogen-15 uptake studies showed that phytoplankton preferred ammonia to nitrate unless ammonia concentrations were less than 0.10 mg/L as nitrogen. Nitrification-rate studies during 1981 using a carbon-14 uptake technique indicate that rates did not vary with sample location, except for one sample from the head of the tidal river, where the rates were much higher. The numbers of Nitrobacter bacteria were highest in samples from near the Blue Plains STP and were greater than the numbers of Nitrosomonas bacteria. The predominance of Nitrobacter bacteria seemed to be associated with advanced wastewater treatment at the Blue Plains STP. Before advanced wastewater treatment, Nitrosomonas were numerically predominant and had the largest numbers near the Blue Plains STP. These results could be due to (1) loading of nitrifying bacteria in the Blue Plains sewage effluent that had been inhibited from further growth by an inhibitory substance or (2) the method used to measure nitrification rates, which measured only the ammonia oxidation stage; it is not possible to reject either mechanism on the basis of the data available. Process models were used in conjunction with mass-balance determinations and individual process studies to estimate rates of processes that were not directly measured. It is estimated that denitrification removed 10 times as much nitrate from the water column during the summer of 1981 as during the summer of 1980. Sedimentation of particulate nitrogen is estimated to be the largest sink for nitrogen from the water column and was approximately equal to the external annual loading of all nitrogen constituents on a daily basis. In summer, when river flows usually are low, the tidal Potomac River appears to be a partially closed system rather tha

Effects of produced water on soil characteristics, plant biomass, and secondary metabolites

USDA-ARS?s Scientific Manuscript database

The Powder River Basin in Wyoming and Montana contains the United States’ largest coal reserve. The area produces large amounts of natural gas through extraction from water-saturated coalbeds. Determining the impacts of coalbed natural gas-produced efflux water on crops is important when considering...

Summary of studies supporting cumulative effects analysis of upper Yellowstone River channel modifications

USGS Publications Warehouse

Auble, Gregor T.; Bowen, Zachary H.; Bovee, Ken D.; Farmer, Adrian H.; Sexton, Natalie R.; Waddle, Terry J.

2004-01-01

The largest portion of the document is an Appendix that summarizes each of the individual scientific studies in terms of scope and methods, findings, principal variables, and metrics used in the study or suggested by the study results, and important needs for further study.

SAN FRANCISCO ESTUARY PROJECT COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

EPA Science Inventory

The Estuary, a significant natural resource, San Francisco Bay and the Delta combine to form the West Coast's largest estuary. The Estuary conveys the waters of the Sacramento and San Joaquin Rivers to the Pacific Ocean. It encompasses roughly 1,600 square miles, drains over 40 p...

Flux of Total Mercury and Methylmercury to the Northern Gulf of Mexico from U.S. Estuaries.

PubMed

Buck, Clifton S; Hammerschmidt, Chad R; Bowman, Katlin L; Gill, Gary A; Landing, William M

2015-12-15

To better understand the source of elevated methylmercury (MeHg) concentrations in Gulf of Mexico (GOM) fish, we quantified fluxes of total Hg and MeHg from 11 rivers in the southeastern United States, including the 10 largest rivers discharging to the GOM. Filtered water and suspended particles were collected across estuarine salinity gradients in Spring and Fall 2012 to estimate fluxes from rivers to estuaries and from estuaries to coastal waters. Fluxes of total Hg and MeHg from rivers to estuaries varied as much as 100-fold among rivers. The Mississippi River accounted for 59% of the total Hg flux and 49% of the fluvial MeHg flux into GOM estuaries. While some estuaries were sources of Hg, the combined estimated fluxes of total Hg (~5200 mol y(-1)) and MeHg (~120 mol y(-1)) from the estuaries to the GOM were less than those from rivers to estuaries, suggesting an overall estuarine sink. Fluxes of total Hg from the estuaries to coastal waters of the northern GOM are approximately an order of magnitude less than from atmospheric deposition. However, fluxes from rivers are significant sources of MeHg to estuaries and coastal regions of the northern GOM.

Impacts of climate change and socio-economic scenarios on flow and water quality of the Ganges, Brahmaputra and Meghna (GBM) river systems: low flow and flood statistics.

PubMed

Whitehead, P G; Barbour, E; Futter, M N; Sarkar, S; Rodda, H; Caesar, J; Butterfield, D; Jin, L; Sinha, R; Nicholls, R; Salehin, M

2015-06-01

The potential impacts of climate change and socio-economic change on flow and water quality in rivers worldwide is a key area of interest. The Ganges-Brahmaputra-Meghna (GBM) is one of the largest river basins in the world serving a population of over 650 million, and is of vital concern to India and Bangladesh as it provides fresh water for people, agriculture, industry, conservation and for the delta system downstream. This paper seeks to assess future changes in flow and water quality utilising a modelling approach as a means of assessment in a very complex system. The INCA-N model has been applied to the Ganges, Brahmaputra and Meghna river systems to simulate flow and water quality along the rivers under a range of future climate conditions. Three model realisations of the Met Office Hadley Centre global and regional climate models were selected from 17 perturbed model runs to evaluate a range of potential futures in climate. In addition, the models have also been evaluated using socio-economic scenarios, comprising (1) a business as usual future, (2) a more sustainable future, and (3) a less sustainable future. Model results for the 2050s and the 2090s indicate a significant increase in monsoon flows under the future climates, with enhanced flood potential. Low flows are predicted to fall with extended drought periods, which could have impacts on water and sediment supply, irrigated agriculture and saline intrusion. In contrast, the socio-economic changes had relatively little impact on flows, except under the low flow regimes where increased irrigation could further reduce water availability. However, should large scale water transfers upstream of Bangladesh be constructed, these have the potential to reduce flows and divert water away from the delta region depending on the volume and timing of the transfers. This could have significant implications for the delta in terms of saline intrusion, water supply, agriculture and maintaining crucial ecosystems such as the mangrove forests, with serious implications for people's livelihoods in the area. The socio-economic scenarios have a significant impact on water quality, altering nutrient fluxes being transported into the delta region.

SE Asian freshwater fish population and networks: the impacts of climatic and environmental change on a vital resource

NASA Astrophysics Data System (ADS)

Santos, Rita; Parsons, Daniel; Cowx, Ian

2016-04-01

The Mekong River is the 10th largest freshwater river in the world, with the second highest biodiversity wealth, behind the much larger Amazon basin. The fisheries activity in the Lower Mekong countries counts for 2.7 million tons of fish per year, with an estimated value worth up to US 7 billion. For the 60 million people living in the basin, fish represent their primary source of economic income and protein intake, with an average per capita consumption estimated at 45.4 Kg. The proposed hydropower development in the basin is threatening its sustainability and resilience. Such developments affect fish migration patterns, hydrograph flood duration and magnitudes and sediment flux. Climate change is also likely to impact the basin, exacerbating the issues created by development. As a monsoonal system, the Mekong River's pronounced annual flood pulse cycle is important in creating variable habitat for fish productivity. Moreover, the annual flood also triggers fish migration and provides vital nutrients carried by the sediment flux. This paper examines the interactions between both dam development and climate change scenarios on fish habitat and habitat connectivity, with the aim of predicting how these will affect fish species composition and fisheries catch. The project will also employ Environmental DNA (eDNA) to quantify and understand the species composition of this complex and large freshwater system. By applying molecular analysis, it is possible to trace species abundance and migration patterns of fish and evaluate the ecological networks establish between an inland system. The aim of this work is to estimate, using process-informed models, the impacts of the proposed dam development and climate change scenarios on the hydrological and hydraulic conditions of habitat availability for fish. Furthermore, it will evaluate the connectivity along the Mekong and its tributaries, and the importance of maintaining these migration pathways, used by a great diversity of fish species. It will also present the preliminary findings on eDNA analysis for species composition and the ecological networks established along the river and particularly on the fish hotspot place for biodiversity, the Tonle Sap system in Cambodia. Keywords: Mekong River, climate change, fish production, dams, eDNA analysis, numerical modelling.

How Do Morphodynamic Signatures Vary Along the Ucayali, a Large Transitional River?

NASA Astrophysics Data System (ADS)

Dauer, K.; Frias, C. E.; Abad, J. D.; Paredes, J.; Vizcarra, J.; Holguin, C.

2013-12-01

The Ucayali River, with an average discharge of 11, 260 m3 ● s-1 at the Requena station, is one of the largest rivers in Peru, and at its confluence with the Maranon River, the Amazon River is born. The Ucayali River transitions from purely meandering to quasi-anabranching planform near the confluence with the Marañon River. In addition, it carries large amounts of suspended sediment and has been shown to display high rates of migration. Prompted by evidence of changing trends in rainfall and discharge in the Amazon basin, where the Ucayali is located, we have performed a baseline characterization of the planform metrics, thus to determine if effects of climatic change on the morphodynamics are happening in this transitional river, which is a vital transportation route for cities in the jungle such as Iquitos, Peru. Herein, the morphodynamics of the Ucayali River are characterized from its upstream end in Atalaya, Peru to its confluence with the Marañon near Nauta City. First, the migration rates along the Ucayali River are calculated from temporal Landsat images. Then migration rates and planform characteristics, such as wavelength and sinuosity, along the river are compared with the slope along the river to distinguish spatial dominant scales. In addition, bathymetry and velocity measurements taken in 2013 along the Ucayali River help us to understand the complex morphodynamics of the river. Specific case studies have been done at Pucallpa and Jenaro-Herrera, Peru using hydrodynamic and bathymetric measurements complemented with high-resolution shallow water modeling to understand the process of cutoff formation in different locations along the river. This study discusses the frequency at which meanders along the Ucayali River shift from low sinuosity to complete maturity in order to produce cutoffs.

Environmental and hydrologic overview of the Yukon River basin, Alaska and Canada

USGS Publications Warehouse

Brabets, Timothy P.; Wang, Bronwen; Meade, Robert H.

2000-01-01

The Yukon River, located in northwestern Canada and central Alaska, drains an area of more than 330,000 square miles, making it the fourth largest drainage basin in North America. Approximately 126,000 people live in this basin and 10 percent of these people maintain a subsistence lifestyle, depending on the basin's fish and game resources. Twenty ecoregions compose the Yukon River Basin, which indicates the large diversity of natural features of the watershed, such as climate, soils, permafrost, and geology. Although the annual mean discharge of the Yukon River near its mouth is more than 200,000 cubic feet per second, most of the flow occurs in the summer months from snowmelt, rainfall, and glacial melt. Eight major rivers flow into the Yukon River. Two of these rivers, the Tanana River and the White River, are glacier-fed rivers and together account for 29 percent of the total water flow of the Yukon. Two others, the Porcupine River and the Koyukuk River, are underlain by continuous permafrost and drain larger areas than the Tanana and the White, but together contribute only 22 percent of the total water flow in the Yukon. At its mouth, the Yukon River transports about 60 million tons of suspended sediment annually into the Bering Sea. However, an estimated 20 million tons annually is deposited on flood plains and in braided reaches of the river. The waters of the main stem of the Yukon River and its tributaries are predominantly calcium magnesium bicarbonate waters with specific conductances generally less than 400 microsiemens per centimeter. Water quality of the Yukon River Basin varies temporally between summer and winter. Water quality also varies spatially among ecoregions

A fate model for nitrogen dynamics in the Scheldt basin

NASA Astrophysics Data System (ADS)

Haest, Pieter Jan; van der Kwast, Johannes; Broekx, Steven; Seuntjens, Piet

2010-05-01

The European Union (EU) adopted the Water Framework Directive (WFD) in 2000 ensuring that all aquatic ecosystems meet ‘good ecological status' by 2015. However, the large population density in combination with agricultural and industrial activities in some European river basins pose challenges for river basin managers in meeting this status. The EU financed AQUAREHAB project (FP7) specifically examines the ecological and economic impact of innovative rehabilitation technologies for multi-pressured degraded waters. For this purpose, a numerical spatio-temporal model is developed to evaluate innovative technologies versus conventional measures at the river basin scale. The numerical model describes the nitrogen dynamics in the Scheldt river basin. Nitrogen is examined since nitrate is of specific concern in Belgium, the country comprising the largest area of the Scheldt basin. The Scheldt basin encompasses 20000 km2 and houses over 10 million people. The governing factors describing nitrogen fluxes at this large scale differ from the field scale with a larger uncertainty on input data. As such, the environmental modeling language PCRaster was selected since it was found to provide a balance between process descriptions and necessary input data. The resulting GIS-based model simulates the nitrogen dynamics in the Scheldt basin with a yearly time step and a spatial resolution of 1 square kilometer. A smaller time step is being evaluated depending on the description of the hydrology. The model discerns 4 compartments in the Scheldt basin: the soil, shallow groundwater, deep groundwater and the river network. Runoff and water flow occurs along the steepest slope in all model compartments. Diffuse emissions and direct inputs are calculated from administrative and statistical data. These emissions are geographically defined or are distributed over the domain according to land use and connectivity to the sewer system. The reactive mass transport is described using literature data. Process-knowledge on the innovative rehabilitation technologies, i.e. wetlands and riparian zones, will be derived from lab and field scale experiments. Datasets provided at the EU level are used to calibrate the model when available. The fate model will be used to create a database driven Decision Support System (DSS) in which costs of measures and ecotoxicological effects are considered. The DSS can then be used to compare alternative combinations of rehabilitation technologies versus conventional measures in the Scheldt river basin taking into account the ecological status of the river basin.

Response of Polish rivers (Vistula, Oder) to reduced pressure from point sources and agriculture during the transition period (1988-2008)

NASA Astrophysics Data System (ADS)

Pastuszak, Marianna; Stålnacke, Per; Pawlikowski, Krzysztof; Witek, Zbigniew

2012-06-01

The Vistula and Oder Rivers, two out of the seven largest rivers in the Baltic drainage basin, were responsible for 25% of total riverine nitrogen (TN) and 37% of total riverine phosphorus (TP) input to the Baltic Sea in 2000. The aim of this paper is to evaluate the response of these two rivers to changes that took place in Polish economy during the transition period (1988-2008). The economic changes encompassed: construction of nearly 900 waste water treatment plants in 1999-2008, modernization or closure of obsolete factories, economizing in water consumption, closure or change of ownership of State-owned farms, a drop in fertilizer application, and a decline in livestock stocking. More intensive agriculture and higher point source emissions in the Oder than in the Vistula basin resulted in higher concentrations of TN, nitrate (NO3-N), and TP in the Oder waters in the entire period of our studies. In both rivers, nutrient concentrations and loads showed significant declining trends in the period 1988-2008. TN loads decreased by ca. 20% and 25% in the Vistula and Oder; TP loads dropped by ca. 15% and 65% in the Vistula and Oder. The reduction in phosphorus loads was particularly pronounced in the Oder basin, which was characterized by efficient management systems aiming at mitigation of nutrient emission from the point sources and greater extent of structural changes in agricultural sector during the transition period. The trends in riverine loads are discussed in the paper in relation to socio-economical changes during the transition period, and with respect to physiographic features.

Concentrations and patterns of perfluoroalkyl acids in Georgia, USA surface waters near and distant to a major use source.

PubMed

Konwick, Brad J; Tomy, Gregg T; Ismail, Nargis; Peterson, James T; Fauver, Rebecca J; Higginbotham, David; Fisk, Aaron T

2008-10-01

Perfluoroalkyl acids (PFAAs) are widespread contaminants emanating from, among other sources, the production/degradation of fluorinated chemicals used in surface repellant applications, such as carpet manufacturing. The goal of the present study was to assess the concentrations of PFAAs, including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUA), and perfluorooctane sulfonamide (PFOSA), in surface waters both near a wastewater land application system (LAS) in Dalton (GA, USA), home to North America's largest carpet manufacturing site, and distant to this location (Altamaha River, GA, USA) to understand the fate of PFAAs in freshwater. Levels of PFAAs were high in the Conasauga River (GA, USA) downstream of the LAS (PFOA, 253-1,150 ng/L; PFOS, 192-318 ng/L; PFNA, 202-369 ng/L; PFDA, 30.1-113 ng/L; PFUA, 58.0-99.2 ng/L; PFOSA, 162-283 ng/L) and in streams and ponds in Dalton (PFOA, 49.9-299 ng/L; PFOS, 15.8-120 ng/L), and were among the highest measured at a nonspill or direct-release location. Perfluoroalkyl acids in the Altamaha River were much lower (PFOA, 3.0-3.1 ng/L; PFOS, 2.6-2.7 ng/L), but were a source of PFAAs to Georgia's estuaries. A preliminary hazard assessment indicated that concentrations of PFOS at two sites in the Conasauga River exceeded the threshold effect predicted for birds consuming aquatic organisms that are exposed continuously to the PFOS levels at these sites. Assuming that toxicity for all PFAAs quantified is equal to that of PFOS, the sum total PFAAs at two sites within the Conasauga River exceeded PFOS thresholds for aquatic and avian species, warranting additional research.

Modeling effects of climate change on Yakima River salmonid habitats

USGS Publications Warehouse

Hatten, James R.; Batt, Thomas R.; Connolly, Patrick J.; Maule, Alec G.

2014-01-01

We evaluated the potential effects of two climate change scenarios on salmonid habitats in the Yakima River by linking the outputs from a watershed model, a river operations model, a two-dimensional (2D) hydrodynamic model, and a geographic information system (GIS). The watershed model produced a discharge time series (hydrograph) in two study reaches under three climate scenarios: a baseline (1981–2005), a 1-°C increase in mean air temperature (plus one scenario), and a 2-°C increase (plus two scenario). A river operations model modified the discharge time series with Yakima River operational rules, a 2D model provided spatially explicit depth and velocity grids for two floodplain reaches, while an expert panel provided habitat criteria for four life stages of coho and fall Chinook salmon. We generated discharge-habitat functions for each salmonid life stage (e.g., spawning, rearing) in main stem and side channels, and habitat time series for baseline, plus one (P1) and plus two (P2) scenarios. The spatial and temporal patterns in salmonid habitats differed by reach, life stage, and climate scenario. Seventy-five percent of the 28 discharge-habitat responses exhibited a decrease in habitat quantity, with the P2 scenario producing the largest changes, followed by P1. Fry and spring/summer rearing habitats were the most sensitive to warming and flow modification for both species. Side channels generally produced more habitat than main stem and were more responsive to flow changes, demonstrating the importance of lateral connectivity in the floodplain. A discharge-habitat sensitivity analysis revealed that proactive management of regulated surface waters (i.e., increasing or decreasing flows) might lessen the impacts of climate change on salmonid habitats.

Impact of the Fraser River Geometry on Tides and the River Plumes in a Model of the Fraser River Plume

NASA Astrophysics Data System (ADS)

Liu, J.; Allen, S. E.; Soontiens, N. K.

2016-02-01

Fraser River is the largest river on the west coast of Canada. It empties into the Strait of Georgia, which is a large, semi-enclosed body of water between Vancouver Island and the mainland of British Columbia. We have developed a three-dimensional model of the Strait of Georgia, including the Fraser River plume, using the NEMO model in its regional configuration. This operational model produces daily nowcasts and forecasts for salinity, temperature, currents and sea surface heights. Observational data available for evaluation of the model includes daily British Columbia ferry salinity data, profile data and surface drifter data. The salinity of the modelled Fraser River plume agrees well with ferry based measurements of salinity. However, large discrepencies exist between the modelled and observed position of the plume. Modelled surface currents compared to drifter observations show that the model has too strong along-strait velocities and too weak cross-strait velocities. We investigated the impact of river geometry. A sensitivity experiment was performed comparing the original, short, shallow river channel to an extended and deepened river channel. With the latter bathymetry, tidal amplitudes within Fraser River correspond well with observations. Comparisons to drifter tracks show that the surface currents have been improved with the new bathymetry. However, substantial discrepencies remain. We will discuss how reducing vertical eddy viscosity and other changes further improve the modelled position of the plume.

Spatio-temporal variation in the hydrochemistry of Tawa River, Central India: effect of natural and anthropogenic factors.

PubMed

Mehto, Ashwini; Chakrapani, G J

2013-12-01

Tawa River is the biggest left bank tributary of the Narmada, the largest west-flowing river of the Indian peninsula. Central India enjoys a tropical climate, is highly urbanized, and the river flow is mostly controlled by monsoon; a large part of the population depend on rivers for their livelihood. Spatial and temporal variations in the hydrochemistry of the Tawa River were studied based on seasonal sampling along the course of the river and its tributaries. The study is important because not much data exist on small size rivers and the river processes spell out correctly in smaller basins. The monsoon season accounts for more than 70% of river water flow. The basin is characterized by silicate lithology; however, water chemistry is controlled by carbonate-rich soils and other weathering products of the silicate rocks, as indicated by the high (Ca + Mg)/(Na + K) ratios (>3.8). The values of the Na-normalized ratios of Ca(2+), Mg(2+), and HCO₃(-) suggest that both the carbonate and silicate lithology contribute to the hydrochemistry. On average, 42% of HCO₃(-) in the Tawa River water is contributed by silicate weathering and 58% from carbonate lithology. The water remains undersaturated with respect to calcite during the monsoon and post-monsoon seasons and supersaturated during the pre-monsoon season. A significant influence of mining in the basin and other industrial units is observed in water chemical composition.

Water Withdrawals, Use, and Wastewater Return Flows in the Concord River Basin, Eastern Massachusetts, 1996-2000

USGS Publications Warehouse

Barlow, Lora K.; Hutchins, Linda M.; Desimone, Leslie A.

2009-01-01

Water withdrawals, use, and wastewater return flows for the Concord River Basin were estimated for the period 1996-2000. The study area in eastern Massachusetts is 400 square miles in area and includes the basins of two major tributaries, the Assabet and Sudbury Rivers, along with the Concord River, which starts at the confluence of the two tributaries. About 400,000 people lived in the basin during the study period, on the basis of an analysis of census data, land use, and population density. Public water systems served an estimated 87 percent of the people in the basin, and public wastewater systems served an estimated 65 percent of the basin population. The estimates of water withdrawals, use, wastewater return flows, and imports and exports for the Concord River Basin and 25 subbasins provide information that can be used in hydrologic analyses such as water budgets and can guide water-resources allocations for human and environmental needs. Withdrawals in the basin were estimated at 12,700 million gallons per year (Mgal/yr) during the study period, of which 10,100 Mgal/yr (about 80 percent) were withdrawn by public water-supply systems and 2,650 Mgal/yr were self-supplied by individual users. Water use in the basin and subbasins was estimated by using water withdrawals, average per capita use rates (about 72 gallons per day per person), land-use data, estimated population densities, and other information. Total water use in the basin, which included imports, was 19,200 Mgal/yr and was provided mostly (86.2 percent) by public supply. Domestic use (11,300 Mgal/yr) was the largest component, accounting for about 60 percent of total water use in the basin. Commercial use (3,770 Mgal/yr), industrial use (1,330 Mgal/yr), and agricultural use (including golf-course irrigation; 562 Mgal/yr) accounted for 19.6, 6.9, and 2.9 percent, respectively, of total use. Water that was unaccounted for in public-supply systems was estimated at 2,260 Mgal/yr, or 11.8 percent of total water use in the basin. Wastewater return flows discharged in the basin were estimated at 11,800 Mgal/yr, of which 6,620 Mgal/yr were discharged from municipal wastewater-treatment facilities to surface waters and 5,190 Mgal/yr were self-disposed through septic systems to ground water; wastewater disposed through septic systems was generated by both public- and self-supply use. Water use and management in the Concord River Basin resulted in an estimated import of 6,460 Mgal/yr of potable water for public supply and an estimated export of 6,590 Mgal/yr of wastewater. Water was imported into the Assabet, Sudbury, and Lower Concord (the area draining directly to the Concord River) River Basins for public supply. Wastewater was imported into the Assabet River Basin, but exported from the Sudbury and Lower Concord River Basins. Of the 25 subbasins in the Concord River Basin for which water use was analyzed, 20 subbasins imported potable water, 4 subbasins exported potable water (Fort Meadow Brook, Indian Brook, Lower Sudbury River, and Whitehall Brook), and potable water was neither imported nor exported in one subbasin (Elizabeth Brook). Wastewater was imported into the Assabet Headwaters, Assabet Main Stem, and Hop Brook subbasins; wastewater was neither imported to nor exported from the Elizabeth Brook, Nashoba Brook, and Pine Brook subbasins; and wastewater was exported from all other subbasins. Water use and management in the basin also resulted in a net transfer of water from ground water to surface water, discharged as wastewater, of about 4,000 Mgal/yr.

Zambezi River Delta

NASA Image and Video Library

2013-08-29

It drains a watershed that spans eight countries and nearly 1.6 million square kilometers 600,000 square miles. The Zambezi also Zambeze is the fourth largest river in Africa, and the largest east-flowing waterway. The Operational Land Imager on the Landsat 8 satellite acquired this natural-color image of the Zambezi Delta on August 29, 2013. Sandbars and barrier spits stretch across the mouths of the delta, and suspended sediment extends tens of kilometers out into the sea. The sandy outflow turns the coastal waters to a milky blue-green compared to the deep blue of open water in the Indian Ocean. The Zambezi Delta includes 230 kilometers of coastline fronting 18,000 square kilometers (7,00 square miles) of swamps, floodplains, and even savannahs (inland). The area has long been prized by subsistence fishermen and farmers, who find fertile ground for crops like sugar and fertile waters for prawns and fish. Two species of endangered cranes and one of the largest concentration of buffalo in Africa -- among many other species of wildlife -- have found a haven in this internationally recognized wetland. However, the past six decades have brought great changes to the Zambezi Delta, which used to pour more water and sediment off of the continent. Hydropower dams upstream-most prominently, the Kariba and the Cahora Bassa-greatly reduce river flows during the wet season; they also trap sediments that would otherwise flow downstream. The result has been less water reaching the delta and the floodplains, which rely on pulses of nutrients and sediments from annual (and mostly benign) natural flooding. The change in the flow of the river affects freshwater availability and quality in the delta. Strong flows push fresh water further out into the sea and naturally keep most of a delta full of fresh (or mostly fresh) water. When that fresh flow eases, the wetlands become drier and more prone to fire. Salt water from the Indian Ocean also can penetrate further into the marsh, upsetting the ecological balance for aquatic plant and animal species. Researchers have found that the freshwater table in the delta has dropped as much as five meters in the 50 years since dams were placed on the river. Less river flow also affects the shape and extent of the delta. Today there is less sediment replenishing the marshes and beaches as they are scoured by ocean waves and tides. "What strikes me in this image is the suspended sediment offshore," said Liviu Giosan, a delta geologist at the Woods Hole Oceanographic Institution. "Sediment appears to be transferred from the delta offshore in plumes that not only originate in active river mouths but also from deactivated former mouths, now tidal channels. This shows the power of tidal scouring contributing to the slow but relentless erosion of the delta." http://photojournal.jpl.nasa.gov/catalog/PIA18155

Dissolved carbon biogeochemistry and export in mangrove-dominated rivers of the Florida Everglades

NASA Astrophysics Data System (ADS)

Ho, David T.; Ferrón, Sara; Engel, Victor C.; Anderson, William T.; Swart, Peter K.; Price, René M.; Barbero, Leticia

2017-05-01

The Shark and Harney rivers, located on the southwest coast of Florida, USA, originate in the freshwater, karstic marshes of the Everglades and flow through the largest contiguous mangrove forest in North America. In November 2010 and 2011, dissolved carbon source-sink dynamics was examined in these rivers during SF6 tracer release experiments. Approximately 80 % of the total dissolved carbon flux out of the Shark and Harney rivers during these experiments was in the form of inorganic carbon, either via air-water CO2 exchange or longitudinal flux of dissolved inorganic carbon (DIC) to the coastal ocean. Between 42 and 48 % of the total mangrove-derived DIC flux into the rivers was emitted to the atmosphere, with the remaining being discharged to the coastal ocean. Dissolved organic carbon (DOC) represented ca. 10 % of the total mangrove-derived dissolved carbon flux from the forests to the rivers. The sum of mangrove-derived DIC and DOC export from the forest to these rivers was estimated to be at least 18.9 to 24.5 mmol m-2 d-1, a rate lower than other independent estimates from Shark River and from other mangrove forests. Results from these experiments also suggest that in Shark and Harney rivers, mangrove contribution to the estuarine flux of dissolved carbon to the ocean is less than 10 %.

Seasonal and spatial patterns in diurnal cycles in streamflow in the western United States

USGS Publications Warehouse

Lundquist, J.D.; Cayan, D.R.

2002-01-01

The diurnal cycle in streamflow constitutes a significant part of the variability in many rivers in the western United States and can be used to understand some of the dominant processes affecting the water balance of a given river basin. Rivers in which water is added diurnally, as in snowmelt, and rivers in which water is removed diurnally, as in evapotranspiration and infiltration, exhibit substantial differences in the timing, relative magnitude, and shape of their diurnal flow variations. Snowmelt-dominated rivers achieve their highest sustained flow and largest diurnal fluctuations during the spring melt season. These fluctuations are characterized by sharp rises and gradual declines in discharge each day. In large snowmelt-dominated basins, at the end of the melt season, the hour of maximum discharge shifts to later in the day as the snow line retreats to higher elevations. Many evapotranspiration/infiltration-dominated rivers in the western states achieve their highest sustained flows during the winter rainy season but exhibit their strongest diurnal cycles during summer months, when discharge is low, and the diurnal fluctuations compose a large percentage of the total flow. In contrast to snowmelt-dominated rivers, the maximum discharge in evapotranspiration/infiltration-dominated rivers occurs consistently in the morning throughout the summer. In these rivers, diurnal changes are characterized by a gradual rise and sharp decline each day.

Water quality assessment of the Sinos River, Southern Brazil.

PubMed

Blume, K K; Macedo, J C; Meneguzzi, A; Silva, L B; Quevedo, D M; Rodrigues, M A S

2010-12-01

The Sinos River basin is located Northeast of the state of Rio Grande do Sul (29º 20' to 30º 10' S and 50º 15' to 51º20'W), Southern Brazil, covering two geomorphologic provinces: the Southern plateau and central depression. It is part of the Guaíba basin and has an area of approximately 800 km², encompassing 32 municipalities. The objective of this study was to monitor water quality in the Sinos River, the largest river in this basin. Water samples were collected at four selected sites in the Sinos River, and the following parameters were analysed: pH, dissolved oxygen, biochemical oxygen demand (BOD₅), turbidity, fecal coliforms, total dissolved solids, temperature, nitrate, nitrite, phosphorous, chromium, lead, aluminum, zinc, iron, and copper. The results were analysed based on Resolution No. 357/2005 of the Brazilian National Environmental Council (CONAMA) regarding regulatory limits for residues in water. A second analysis was performed based on a water quality index (WQI) used by the Sinos River Basin Management Committee (COMITESINOS). Poor water quality in the Sinos River presents a worrying scenario for the region, since this river is the main source of water supply for the urban core. Health conditions found in the Sinos River, mainly in its lower reaches, are worrying and a strong indicator of human activities on the basin.

The case of the Upper Rhine: unravelling the past, wrapping up the future

NASA Astrophysics Data System (ADS)

Ergenzinger, P.; Bölscher, J.; de Jong, C.

2003-04-01

The southern Upper Rhine was once the most prominent braided river system in Germany. However it lost its character during the last 200 years and is now a trained river used for electricity and carrying ships to Basel(CH). The river sector between Basel and Strasburg(F) was always different to the Hochrhein (Lake Constance Basel) and to the lower Upper Rhine (Strasburg Bingen(D)). This ancient braided river system changed downstream according to the transition of grain sizes from cobbles to gravel and sand. Between Strasburg and Lauterburg(F) the braids were replaced by meanders and this geomorphological change induced many other changes. At thesed times the ecology, including the use of water and land, riparian forests, the development of flood defence and navigation were different. In addition there was a further problem for people living in the time of enlightment: how should the boundary of a state be defined within a braided river? In the German language braided rivers were and are still called “verwildert” and this means the river is going wild. As such, somebody who was able to improve this situation would gain merits. This happened to Johann Gottfried Tulla. He became the responsible engineer for river construction in the Great Duchy Baden. In 1812 he created a memorandum with recommodations for the future development of the river Rhine. Only 5 years later he succeeded with the first cutoff of a meander next to Karlsruhe. After his death a treaty between France and Baden regulated the elimination of the braided system between Basel and Lauterburg. The construction took place between 1840 and 1875. This development was opposed locally and by the Prussian and Dutch authorities who claimed - after the huge flood of 1824 - that the abnormal flood peak was a result of the meander cutoffs created in Baden. Nevertheless the results of training the braided system were technically convincing: a deeper river channel, less floods, a well defined border and finally the first bigger steamboats entering the new harbor of Basel. The new situation was settled by the peace treaty of Versailles with its entrustment of the Rhine to France. This resulted in the construction of the Canal d’Alsace between the wars and after the last World War. Wrapping up the future of the Upper Rhine cannot be a turn back to the past, but should be an attempt to reduce the deficits and to amplify the ecological benefits. As already stated in 1824 the new river system causes more peaky floods and induces a deficit of bedload. The last problem was overcome by a bedload management scheme proposed by Felkel in 1970. For flood protection a German-French agreement defined the ’integrated Rhine programm’ in 1982 to create more flood storage capacity using the following approaches: - special operation of the power scheme, - construction of more weire and more flood polders. The largest retention measure so far is planned along the Restrhein between the weir at the entrance of the Canal d’Alsace and Breisach(D). A strip of approx. 95 m width the ancient floodplain on the German side will be excavated down to the groundwater level in order to develop a new artificial floodplain capable of storing approx. 25 million m3 of floodwater. This project will not only create a new river but will be encountered by 50 million m3 of sediments which have to be removed and sold. The development of the Upper Rhine is an extreme example for river genesis during the last 200 years. There is no way back to the future but only the possibility to create an improved and more sustainable riversystem for the next century.

Concentrations of metals associated with mining waste in sediments, biofilm, benthic macroinvertebrates, and fish from the Coeur d'Alene River Basin, Idaho

USGS Publications Warehouse

Farag, A.M.; Woodward, D.F.; Goldstein, J.N.; Brumbaugh, W.; Meyer, J.S.

1998-01-01

Arsenic, Cd, Cu, Pb, Hg, and Zn were measured in sediments, biofilm, benthic macroinvertebrates, and fish from the Coeur d'Alene (CDA) River to characterize the pathway of metals transfer between these components. Metals enter the CDA Basin via tributaries where mining activities have occurred. In general, the ranking of food-web components from the greatest to smallest concentrations of metals was as follows: biofilm (the layer of abiotic and biotic material on rock surfaces) and sediments > invertebrates > whole fish. Elevated Pb was documented in invertebrates, and elevated Cd and Zn were documented in sediment and biofilm approximately 80 km downstream to the Spokane River. The accumulation of metals in invertebrates was dependent on functional feeding group and shredders-scrapers that feed on biofilm accumulated the largest concentrations of metals. Although the absolute concentrations of metals were the largest in biofilm and sediments, the metals have accumulated in fish approximately 50 km downstream from Kellogg, near the town of Harrison. While metals do not biomagnify between trophic levels, the metals in the CDA Basin are bioavailable and do biotransfer. Trout less than 100 mm long feed exclusively on small invertebrates, and small invertebrates accumulate greater concentrations of metals than large invertebrates. Therefore, early-lifestage fish may be exposed to a larger dose of metals than adults.

Modulation of Extreme Flood Levels by Impoundment Significantly Offset by Floodplain Loss Downstream of the Three Gorges Dam

NASA Astrophysics Data System (ADS)

Mei, Xuefei; Dai, Zhijun; Darby, Stephen E.; Gao, Shu; Wang, Jie; Jiang, Weiguo

2018-04-01

River flooding—the world's most significant natural hazard—is likely to increase under anthropogenic climate change. Most large rivers have been regulated by damming, but the extent to which these impoundments can mitigate extreme flooding remains uncertain. Here the catastrophic 2016 flood on the Changjiang River is first analyzed to assess the effects of both the Changjiang's reservoir cascade and the Three Gorges Dam (TGD), the world's largest hydraulic engineering project on downstream flood discharge and water levels. We show that the Changjiang's reservoir cascade impounded over 30.0 × 103 m3/s of flow at the peak of the flood on 25 July 2016, preventing the occurrence of what would otherwise have been the second largest flood ever recorded in the reach downstream of the TGD. Half of this flood water storage was retained by the TGD alone, meaning that impoundment by the TGD reduced peak water levels at the Datong hydrometric station (on 25 July) by 1.47 m, compared to pre-TGD conditions. However, downstream morphological changes, in particular, extensive erosion of the natural floodplain, offset this reduction in water level by 0.22 m, so that the full beneficial impact of floodwater retention by the TGD was not fully realized. Our results highlight how morphological adjustments downstream of large dams may inhibit their full potential to mitigate extreme flood risk.

The Quaternary and Pliocene Yellowstone Plateau volcanic field of Wyoming, Idaho, and Montana

USGS Publications Warehouse

Christiansen, Robert L.

2001-01-01

This region of Yellowstone National Park has been the active focus of one of the Earth's largest magmatic systems for more than 2 million years. The resulting volcanism has been characterized by the eruption of voluminous rhyolites and subordinate basalts but virtually no lavas of intermediate composition. The magmatic system at depth remains active and drives the massive hydrothermal circulation for which the park is widely known. Studies of the volcanic field using geologic mapping and petrology have defined three major cycles of rhyolitic volcanism, each climaxed by the eruption of a rhyolitic ash-flow sheet having a volume of hundreds of thousands of cubic kilometers. The field also has been analyzed in terms of its magmatic and tectonic evolution, including its regional relation to the Snake River plain and to basin-range tectonic extension.

Flood of February 1980 along the Agua Fria River, Maricopa County, Arizona

USGS Publications Warehouse

Thomsen, B.W.

1980-01-01

The flood of February 20, 1980, along the Agua Fria River below Waddell Dam, Maricopa County, Ariz., was caused by heavy rains during February 13-20. The runoff filled Lake Pleasant and resulted in the largest release--66,600 cubic feet per second--from the reservoir since it was built in 1927; the maximum inflow to the reservoir was about 73,300 cubic feet per second. The area inundated by the releases includes about 28 miles along the channel from the mouth of the Agua Fria River to the Beardsley Canal flume crossing 5 miles downstream from Waddell Dam. The flood of 1980 into Lake Pleasant has a recurrence interval of about 47 years, whereas the flood of record (1919) has a recurrence interval of about 100 years. (USGS)

Experiences and recommendations in deploying a real-time, water quality monitoring system

NASA Astrophysics Data System (ADS)

O'Flynn, B.; Regan, F.; Lawlor, A.; Wallace, J.; Torres, J.; O'Mathuna, C.

2010-12-01

Monitoring of water quality at a river basin level to meet the requirements of the Water Framework Directive (WFD) using conventional sampling and laboratory-based techniques poses a significant financial burden. Wireless sensing systems offer the potential to reduce these costs considerably, as well as provide more useful, continuous monitoring capabilities by giving an accurate idea of the changing environmental and water quality in real time. It is unlikely that the traditional spot/grab sampling will provide a reasonable estimate of the true maximum and/or mean concentration for a particular physicochemical variable in a water body with marked temporal variability. When persistent fluctuations occur, it is likely only to be detected through continuous measurements, which have the capability of detecting sporadic peaks of concentration. Thus, in situ sensors capable of continuous sampling of parameters required under the WFD would therefore provide more up-to-date information, cut monitoring costs and provide better coverage representing long-term trends in fluctuations of pollutant concentrations. DEPLOY is a technology demonstration project, which began planning and station selection and design in August 2008 aiming to show how state-of-the-art technology could be implemented for cost-effective, continuous and real-time monitoring of a river catchment. The DEPLOY project is seen as an important building block in the realization of a wide area autonomous network of sensors capable of monitoring the spatial and temporal distribution of important water quality and environmental target parameters. The demonstration sites chosen are based in the River Lee, which flows through Ireland's second largest city, Cork, and were designed to include monitoring stations in five zones considered typical of significant river systems--these monitor water quality parameters such as pH, temperature, depth, conductivity, turbidity and dissolved oxygen. Over one million data points have been collected since the multi-sensor system was deployed in May 2009. Extreme meteorological events have occurred during the period of deployment and the collection of real-time water quality data as well as the knowledge, experience and recommendations for future deployments are discussed.

Africa's Megafans and Their Tectonic Setting

NASA Technical Reports Server (NTRS)

Wilkinson, M. J.; Burke, K.

2016-01-01

Megafans are a really extensive continental sediment bodies, fluvially derived, and fan-shaped in planform. Only those >80 km long were included in this study. Africa's megafans were mapped for purposes of both comprehensive geomorphic description and as a method of mapping by remote sensing large probable fluvial sediment bodies (we exclude sediment bodies deposited in well defined, modern floodplains and coastal deltas). Our criteria included a length dimension of >80 km and maximum width >40 km, partial cone morphology, and a radial drainage pattern. Visible and especially IR imagery were used to identify the features, combined with topographic SRTM data. We identified 99 megafans most of which are unstudied thus far. Their feeder rivers responsible for depositing megafan sediments rise on, and are consequent drainages oriented down the slopes of the swells that have dominated African landscapes since approximately 34 Ma (the high points in Africa's so-called basin-and-swell topography [1]). Most megafans (66%) have developed along these consequent rivers relatively near the swell cores, oriented radially away from the swells. The vast basins between the swells provide accommodation for megafan sediment wedges. Although clearly visible remotely, most megafans are inactive as a result of incision by the feeder river (which then no longer operates on the fan surface). Two tectonic settings control the location of Africa's megafans, 66% on swell flanks, and 33% related to rifts. (i) Swell flanks Most megafans are apexed relatively near the core of the parent swell, and are often clustered in groups: e.g., six on the west and north flanks of the Hoggar Swell (Algeria), seven on the north and south flanks of the Tibesti Swell (Libya-Chad borderlands), twelve on the west flank of the Ethiopian Swell, four on the east flank of the East African Swell (Kenya), Africa's largest, and eight around Angola's Bié Swell (western Zambia, northern Namibia). A cluster of possible fans lies on the western margin of the Congo Basin (Mayombe Swell), and on the coastal slopes of the Namibia Swell. Sheer size may have militated aginst the recognition of many megafans: the largest in the Sahara are the Teghahart (378 km, Hoggar Swell, Algeria), and the Wadi Albalata (340 km, Uweinat Swell, Egypt). In southern Africa the largest are the Cubango (320 km, Bié Swell, Angola/ Namibia), and the Limpopo (230 km, Mozambique). (ii) Rift zones (a) Steer's horns basins-wide depressions centered on rifts. The largest contiguous group (n=14) developed in a steer's-horns basin occupies the wide Muglad depression (200-350 km, South Sudan). Four rift-related megafans lie SE of Lake Chad (Chad). Nine megafans occupy the complex Anza Rift in Kenya/South Somalia. The Salamat megafan (Chad), is unusual because it oriented parallel with the linked Salamat, Doseo and Doba rift axes, and is consequently one of the longest in Africa (465 km). (b) Rift depressions sensu stricto. Most rifts are too narrow to provide a transverse dimension large enough to accommodate megafans. Although well-known, the Okavango Rift (NW Botswana, NE Namibia) is unique in Africa in hosting three megafans within identifiable faulted margins. The Nile megafan is Africa's largest (476 km) and comprises the vast Sudd wetland (South Sudan). An explanation for its remarkable size may be its location in a depression at the junction of two conducive tectonic zones, the East African Swell margin and the Muglad steer's-horns depression. Discharge of the River Nile, the largest in the region, has allowed the Nile megafan to outcompete neighboring megafans for space.

The Brahmaputra River: a stratigraphic analysis of Holocene avulsion and fluvial valley reoccupation history

NASA Astrophysics Data System (ADS)

Hartzog, T. R.; Goodbred, S. L.

2011-12-01

The Brahmaputra River, one of the world's largest braided streams, is a major component of commerce, agriculture, and transportation in India and Bangladesh. Hence any significant change in course, morphology, or behavior would be likely to influence the regional culture and economy that relies on this major river system. The history of such changes is recorded in the stratigraphy deposited by the Brahmaputra River during the Holocene. Here we present stratigraphic analysis of sediment samples from the boring of 41 tube wells over a 120 km transect in the upper Bengal Basin of northern Bangladesh. The transect crosses both the modern fluvial valley and an abandoned fluvial valley about 60 km downstream of a major avulsion node. Although the modern Brahmaputra does not transport gravel, gravel strata are common below 20 m with fluvial sand deposits dominating most of the stratigraphy. Furthermore, the stratigraphy preserves very few floodplain mud strata below the modern floodplain mud cap. These preliminary findings will be assessed to determine their importance in defining past channel migration, avulsion frequency, and the reoccupation of abandoned fluvial valleys. Understanding the avulsion and valley reoccupation history of the Brahmaputra River is important to assess the risk involved with developing agriculture, business, and infrastructure on the banks of modern and abandoned channels. Based on the correlation of stratigraphy and digital surface elevation data, we hypothesize that the towns of Jamalpur and Sherpur in northern Bangladesh were once major ports on the Brahmaputra River even though they now lie on the banks of small underfit stream channels. If Jamalpur and Sherpur represent the outer extent of the Brahmaputra River braid-belt before the last major avulsion, these cities and any communities developed in the abandoned braid-belt assume a high risk of devastation if the next major avulsion reoccupies this fluvial valley. It is important to scrutinize the entire Holocene stratigraphic record of Brahmaputra River avulsion and valley reoccupation to provide evidence for the assessment of risk involved with future occurrences. Thomas R. Hartzog, Steven L. Goodbred, Jr., Jennifer L. Pickering, Haley E. Briel, Dhiman R. Mondal, Zobayer Mahmud, Saddam Hossain

Feedback of Erosional-Depositional Processes Generating Anabranching Patterns in a Mega-River the Case of the PARANÁ River, Argentina

NASA Astrophysics Data System (ADS)

Latrubesse, E. M.; Pereira, M.; Ramonell, C. G.; Szupiany, R. N.

2011-12-01

A new category of "very large" rivers was recently proposed and defined as mega-rivers, which are those rivers with a Qmean of more than ~17,000m3/s. This category includes the nine largest rivers on Earth and the Parana River is one of the selected members of that peculiar group. The planform adjustment of mega-rivers is a variety of anabranching patterns characterized by the existence of alluvial islands. The processes and mechanisms involved in the generation of the different anabranching styles, however, are not well understood. The Paraná channel pattern has been classified as a low to moderate anabranching, low sinuosity with tendency to braided and having a meandering thalweg. We analyzed a reach of the middle Paraná in Argentina applying a combined multitemporal, hydraulic, sedimentologic and geomorphologic approach. Multitemporal geomorphologic maps, sedimentary descriptions of bars, islands and banks, volumetric calculations using multitemporal bathymetric charts, measurements with ADCP and bathymetric surveys with echosound, sediment transport estimations and the hydrological analysis of available data from gauge stations were some of the tools used in our research. The evolution of the reach was studied from 1908 to present. The reach is subdivided in two sub-reaches (named Chapeton and Curtiembre) which are comprised between nodal points. Chapeton has been in a more mature quasi-equilibrium state through the XX Century but the main channel in Curtiembre evolved from a single pattern to anabranching pattern since 1950s. We conclude that the generation of the anabranching pattern in the studied reach depends of a combination of factors such as the architecture of the floodplain and islands, the main role played by the morphodynamics and shifting of the thalweg, the availability and path of sandy sediments bedforms architecture and the temporal variability of the effective discharge among other secondary factors. A feedback system coupling erosional/depositional processes at the decadal scale seems to be the main responsible for the generation of the complex anabranching pattern in such subreaches.

Renewable and Sustainable Study of Groundwater Flow System based on Numerical Simulation in Qaidam Basin, China

NASA Astrophysics Data System (ADS)

Cui, Y.

2015-12-01

In order to study surface water and groundwater exchange and renewal capacity of groundwater system of Qaidam Basin, inland northwest China, TOUGH2 (Transport of Unsaturated Groundwater and Heat 2) simulation software was used to establish a two-dimensional variable saturated numerical model of a typical cross-section from the Nuomuhong river to the Amunike mountain. According to previous results, evaporation is a function of soil saturation given as an upper boundary to characterize water transport near surface through iterative calculation. Parameters were calibrated with 52 groundwater observation data by trial-and-error method. Particle tracking and isotopic dating results were combined to simulate groundwater age and calibrate models. The results showed that the typical profile of Qaidam basin can be divided into three lumped groundwater flow systems: (1) The circulation depth (CD) of local groundwater flow system is about 200m, where discharge in this lumped system accounts for 74.4% of the total amount of discharge (TAD), of which spring overflow constitutes large fraction. Groundwater age is generally less than 500 years and renewal rate is 1.13% a-1; (2) The CD of middle flow system can reach 800m, where it takes up 18.5% of TAD, evaporation and river overflows is the main outlet of discharge. Groundwater age is generally less than 10ka and renewal rate is 0.094% a-1; (3) The CD of regional flow system is from 1000 to 1500m. It accounts for 7.1% of TAD, of which evaporation is the largest component. Groundwater age is from 10ka to 50ka and renewal rate of which is 0.0074% a-1. Sulingguole river is the discharge area of regional groundwater system, the age of which is greater than 30ka. The method used here can obtain the renewal capacity of groundwater system and better reflect regional circulation characteristics, which have certain significance for the urgent study of regional groundwater circulation and flow systems in areas with limited available data.

Predicting S2S in Deep Time Sedimentary Systems and Implications for Petroleum Systems

NASA Astrophysics Data System (ADS)

Bhattacharya, J.

2013-12-01

The source to sink concept is focused on quantification of the various components of siliciclastic sedimentary systems from initial source areas, through the dispersal system, and deposition within a number of potential ultimate sedimentary sinks. Sequence stratigraphy shows that depositional system are linked through time and show distinctively predictable 3D stratigraphic organization, which can be related to cycles of relative changes in accommodation and sediment supply. For example, erosion and formation of incised fluvial valleys generally occur during periods of falling base level with lowstand reservoir deposits favored in more basin distal settings (e.g. deepwater fans), whereas during highstands of sea level, significantly more sediment may be sequestered in the non-marine realm and more distal environments may favor deposition of slowly-deposited condensed sections, which may make excellent hydrocarbon source rocks. Only more recently have attempts been made to quantify the size and scaling relationships of the ultimate source areas on the basis of analysis of ancient depositional systems, and the use of these scaling relationships to predict the sixe of linked depositional systems along the S2S tract. The maximum size of depositional systems, such as rivers, deltas, and submarine fans, is significantly controlled by the area, relief, and climate regime of the source area, which in turn may linked to the plate tectonic and paleogeographic setting. Classic provenance studies, and more recent use of detrital zircons, provide critical information about source-areas, and may help place limits on the size and relief of a drainage basin. Provenance studies may also provide key information about rates of exhumation of source areas and the link to the tectonic setting, Examination of ancient river systems in the rock record, and especially the largest trunk rivers, which are typically within incised valleys, can also be used to estimate paleodischarge, which in turn can be linked to the drainage basin to make estimates about the size and sale of the source area. The best estimates can be made in basins with well-constrained data that allow details of cross-sectional or plan-view channel-architecture to be determined, such as extensive outcrops, or abundant subsurface data, and especially where higher resolution 3D seismic data are available. Paleodischarge estimates of lowstand Quaternary-age continental-scale ancient rivers from passive continental margins, using seismic data, are orders-of-magnitude higher (1000's of cumecs) than smaller-scale Cretaceous lowstand systems that drained into the Western-Interior Seaway of North America (100s of cumecs). Paleodischarge of rivers can also be estimated independently by integrating estimates of drainage basin area and paleoclimate. These can be compared with paleodischarge estimates based on the river deposits themselves. The integration of paleodischarge estimates with more sophisticated provenance analysis should enable improved use of the sedimentary record to make estimates about the entire S2S system, as opposed to primarily the depositional component. A more quantitative approach to estimating the scale of sedimentary systems, and especially in the context of source areas, also puts constraints on the size and scale of potential hydrocarbon reservoirs and thus has economic value.

The River Corridor Closure Contract How Washington Closure Hanford is Closing A Unique Department of Energy Project - 12425

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

Feist, E.T.

2012-07-01

Cleanup of the Hanford River Corridor has been one of Hanford Site's top priorities since the early 1990's. This urgency is due to the proximity of hundreds of waste sites to the Columbia River and the groundwater that continues to threaten the Columbia River. In April 2005, the U.S. Department of Energy, Richland Operations Office (DOE-RL) awarded the Hanford River Corridor Closure Contract (RCCC), a cost-plus incentive-fee closure contract with a 2015 end date and first of its kind at Hanford Site, to Washington Closure Hanford (WCH), a limited-liability company owned by URS, Bechtel National, and CH2M HILL. WCH ismore » a single-purpose company whose goal is to safely, compliantly, and efficiently accelerate cleanup in the Hanford River Corridor and reduce or eliminate future obligations to DOE-RL for maintaining long-term stewardship over the site. Accelerated performance of the work-scope while keeping a perspective on contract completion presents challenges that require proactive strategies to support the remaining work-scope through the end of the RCCC. This paper outlines the processes to address the challenges of completing work-scope while planning for contract termination. WCH is responsible for cleanup of the River Corridor 569.8 km{sup 2} (220 mi{sup 2}) of the 1,517.7 km{sup 2} (586 mi{sup 2}) Hanford Site's footprint reduction. At the end of calendar year 2011, WCH's closure implementation is well underway. Fieldwork is complete in three of the largest areas within the RCCC scope (Segments 1, 2, and 3), approximately 44.5% of the River Corridor (Figure 3). Working together, DOE-RL and WCH are in the process of completing the 'paper work' that will document the completion of the work-scope and allow DOE-RL to relieve WCH of contractual responsibilities and transition the completed areas to the Long-Term Stewardship Program, pending final action RODs. Within the next 4 years, WCH will continue to complete cleanup of the River Corridor following the completion goals. As field work-scope is completed, progressive reductions of business processes, physical facilities, and staff will occur. Organizations will collapse and flatten commensurate with workload. WCH employees will move on to new endeavors, proud of their accomplishments and the legacy they are leaving behind as being the first and largest environmental cleanup closure contract at Hanford. (authors)« less

Asia High Mountain Glacier Mass Balance

NASA Astrophysics Data System (ADS)

Shum, C. K.; Su, X.; Shang, K.; Cogley, J. G.; Zhang, G.; Howat, I. M.; Braun, A.; Kuo, C. Y.

2015-12-01

The Asian High Mountain encompassing the Qinghai-Tibetan Plateau has the largest glaciated regions in the world outside of Greenland and Antarctica. The Tibetan Plateau is the source or headwater of many major river systems, which provide water resources to more than a billion people downstream. The impact of climate change on the Tibetan Plateau physical processes, including mountain glacier wastage, permafrost active layer thickening, the timing and the quantity of the perennial snowpack melt affecting upstream catchments, river runoffs, land-use, have significant effects on downstream water resources. Exact quantification of the Asian High Mountain glacier wastage or its mass balance on how much of the melt water contributes to early 21st century global sea-level rise, remain illusive or the published results are arguably controversial. The recent observed significant increase of freshwater storage within the Tibetan Plateaus remains a limitation to exactly quantify mountain glacier wastage. Here, we provide an updated estimate of Asia high mountain glacier mass balance using satellite geodetic observations during the last decade, accounting for the hydrologic and other processes, and validated against available in situ mass balance data.

Role of sectoral and multi-pollutant emission control strategies in improving atmospheric visibility in the Yangtze River Delta, China.

PubMed

Huang, Kan; Fu, Joshua S; Gao, Yang; Dong, Xinyi; Zhuang, Guoshun; Lin, Yanfen

2014-01-01

The Community Multi-scale Air Quality modeling system is used to investigate the response of atmospheric visibility to the emission reduction from different sectors (i.e. industries, traffic and power plants) in the Yangtze River Delta, China. Visibility improvement from exclusive reduction of NOx or VOC emission was most inefficient. Sulfate and organic aerosol would rebound if NOx emission was exclusively reduced from any emission sector. The most efficient way to improve the atmospheric visibility was proven to be the multi-pollutant control strategies. Simultaneous emission reductions (20-50%) on NOx, VOC and PM from the industrial and mobile sectors could result in 0.3-1.0 km visibility improvement. And the emission controls on both NOx (85%) and SO2 (90%) from power plants gained the largest visibility improvement of up to 4.0 km among all the scenarios. The seasonal visibility improvement subject to emission controls was higher in summer while lower in the other seasons. Copyright © 2013 Elsevier Ltd. All rights reserved.

Suspended sediment load below open-cast mines for ungauged river basin

NASA Astrophysics Data System (ADS)

Kuksina, L.

2011-12-01

Placer mines are located in river valleys along river benches or river ancient channels. Frequently the existing mining sites are characterized by low contribution of the environmental technologies. Therefore open-pit mining alters stream hydrology and sediment processes and enhances sediment transport. The most serious environmental consequences of the sediment yield increase occur in the rivers populated by salmon fish community because salmon species prefer clean water with low turbidity. For instance, placer mining located in Kamchatka peninsula (Far East of Russia) which is regarded to be the last global gene pool of wild salmon Oncorhynchus threatens rivers ecosystems significantly. Impact assessment is limited by the hydrological observations scarcity. Gauging network is rare and in many cases whole basins up to 200 km length miss any hydrological data. The main purpose of the work is elaboration of methods for sediment yield estimation in rivers under mining impact and implementation of corresponding calculations. Subjects of the study are rivers of the Vivenka river basin where open-cast platinum mine is situated. It's one of the largest platinum mines in Russian Federation and in the world. This mine is the most well-studied in Kamchatka (research covers a period from 2003 to 2011). Empirical - analytical model of suspended sediment yield estimation was elaborated for rivers draining mine's territories. Sediment delivery at the open-cast mine happens due to the following sediment processes: - erosion in the channel diversions; - soil erosion on the exposed hillsides; - effluent from settling ponds; - mine waste water inflow; - accident mine waste water escape into rivers. Sediment washout caused by erosion was estimated by repeated measurements of the channel profiles in 2003, 2006 and 2008. Estimation of horizontal deformation rates was carried out on the basis of erosion dependence on water discharge rates, slopes and composition of sediments. Soil erosion on the exposed hillsides was estimated taking into account precipitation of various intensity and solid material washout during this period. Effluent from settling ponds was calculated on the basis of minimum anthropogenic turbidity. Its value is difference in background turbidity and minimal turbidity caused by effluent and waste water overflow. Mine waste water inflow was estimated due to actual data on water balance of purification system. Accident mine waste water escape into rivers was estimated by duration and material washout during accidents data measured during observation period. Total suspended sediment yield of rivers draining mine's territory is the sum of its components. Total sediment supply from mining site is 24.7 % from the Vivenka sediment yield. Polluted placer-mined rivers contribute about 35.4 % of the whole sediment yield of the Vivenka river. At the same time the catchment area of these rivers is less than 0.2 % from the whole Vivenka catchment area.

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.

Spatio-temporal variations in age structures of a partially re-established population of northern river otters (Lontra canadensis)

USGS Publications Warehouse

Barrett, Dominic A.; Leslie, David M.

2012-01-01

Examination of age structures and sex ratios is useful in the management of northern river otters (Lontra canadensis) and other furbearers. Reintroductions and subsequent recolonizations of river otters have been well documented, but changes in demographics between expanding and established populations have not been observed. As a result of reintroduction efforts, immigration from Arkansas and northeastern Texas, and other efforts, river otters have become partially reestablished throughout eastern and central Oklahoma. Our objective was to examine age structures of river otters in Oklahoma and identify trends that relate to space (watersheds, county) and time (USDA Animal and Plant Health Inspection Service county trapping records). We predicted that river otters in western areas of the state were younger than river otters occurring farther east. From 2005–2007, we obtained salvaged river otter carcasses from federal and state agencies, and we live-captured other river otters using leg hold traps. Seventy-two river otters were sampled. Overall, sex ratios were skewed toward females (1F∶0.8M), but they did not differ among spatiotemporal scales examined. Teeth were removed from salvaged and live-captured river otters (n  =  63) for aging. One-year old river otters represented the largest age class (30.2%). Proportion of juveniles (<1 y old) in Oklahoma (19.0%) was less than other states. Mean age of river otters decreased from east-to-west in the Arkansas River and its tributaries. Mean age of river otters differed between the Canadian River Watershed (0.8 y) and the Arkansas River Watershed (2.9 y) and the Canadian River Watershed and the Red River Watershed (2.4 y). Proportion of juveniles did not differ among spatiotemporal scales examined. Similar to age structure variations in other mammalian carnivores, colonizing or growing western populations of river otters in Oklahoma contained younger ages than more established eastern populations.

River Export of Plastic from Land to Sea: A Global Modeling Approach

NASA Astrophysics Data System (ADS)

Siegfried, Max; Gabbert, Silke; Koelmans, Albert A.; Kroeze, Carolien; Löhr, Ansje; Verburg, Charlotte

2016-04-01

Plastic is increasingly considered a serious cause of water pollution. It is a threat to aquatic ecosystems, including rivers, coastal waters and oceans. Rivers transport considerable amounts of plastic from land to sea. The quantity and its main sources, however, are not well known. Assessing the amount of macro- and microplastic transport from river to sea is, therefore, important for understanding the dimension and the patterns of plastic pollution of aquatic ecosystems. In addition, it is crucial for assessing short- and long-term impacts caused by plastic pollution. Here we present a global modelling approach to quantify river export of plastic from land to sea. Our approach accounts for different types of plastic, including both macro- and micro-plastics. Moreover, we distinguish point sources and diffuse sources of plastic in rivers. Our modelling approach is inspired by global nutrient models, which include more than 6000 river basins. In this paper, we will present our modelling approach, as well as first model results for micro-plastic pollution in European rivers. Important sources of micro-plastics include personal care products, laundry, household dust and car tyre wear. We combine information on these sources with information on sewage management, and plastic retention during river transport for the largest European rivers. Our modelling approach may help to better understand and prevent water pollution by plastic , and at the same time serves as 'proof of concept' for future application on global scale.

Transport of diazinon in the San Joaquin River Basin, California

USGS Publications Warehouse

Kratzer, C.R.

1999-01-01

Most of the application of the organophosphate insecticide diazinon in the San Joaquin River Basin occurs in winter to control wood-boring insects in dormant almond orchards. A federal-state collaborative study found that diazinon accounted for most of the observed toxicity of San Joaquin River water in February 1993. Previous studies focused mainly on west-side inputs to the San Joaquin River. In this 1994 study, the three major east-side tributaries to the San Joaquin River - the Merced, Tuolumne, and Stanislaus rivers - and a downstream site on the San Joaquin River were sampled throughout the hydrographs of a late January and an early February storm. In both storms, the Tuolumne River had the highest concentrations of diazinon and transported the largest load of the three tributaries. The Stanislaus River was a small source in both storms. On the basis of previous storm sampling and estimated travel times, ephemeral west-side creeks probably were the main diazinon source early in the storms, whereas the Tuolumne and Merced rivers and east-side drainages directly to the San Joaquin River were the main sources later. Although 74 percent of diazinon transport in the San Joaquin River during 1991-1993 occurred in January and February, transport during each of the two 1994 storms was only 0.05 percent of the amount applied during preceding dry periods. Nevertheless, some of the diazinon concentrations in the San Joaquin River during the January storm exceeded 0.35 ??g/L, a concentration shown to be acutely toxic to water fleas. On the basis of this study and previous studies, diazinon concentrations and streamflow are highly variable during January and February storms, and frequent sampling is required to evaluate transport in the San Joaquin River Basin.

Vanishing river ice cover in the lower part of the Danube basin - signs of a changing climate.

PubMed

Ionita, M; Badaluta, C -A; Scholz, P; Chelcea, S

2018-05-21

Many of the world's largest rivers in the extra tropics are covered with ice during the cold season, and in the Northern Hemisphere approximately 60% of the rivers experience significant seasonal effects of river ice. Here we present an observational data set of the ice cover regime for the lower part of the Danube River which spans over the period 1837-2016, and its the longest one on record over this area. The results in this study emphasize the strong impact of climate change on the occurrence of ice regime especially in the second part of the 20 th century. The number of ice cover days has decreased considerably (~28days/century) mainly due to an increase in the winter mean temperature. In a long-term context, based on documentary evidences, we show that the ice cover occurrence rate was relatively small throughout the Medieval Warm Period (MWP), while the highest occurrence rates were found during the Maunder Minimum and Dalton Minimum periods. We conclude that the river ice regime can be used as a proxy for the winter temperature over the analyzed region and as an indicator of climate-change related impacts.

Tidal controls on river delta morphology

NASA Astrophysics Data System (ADS)

Hoitink, A. J. F.; Wang, Z. B.; Vermeulen, B.; Huismans, Y.; Kästner, K.

2017-09-01

River delta degradation has been caused by extraction of natural resources, sediment retention by reservoirs, and sea-level rise. Despite global concerns about these issues, human activity in the world’s largest deltas intensifies. Harbour development, construction of flood defences, sand mining and land reclamation emerge as key contemporary factors that exert an impact on delta morphology. Tides interacting with river discharge can play a crucial role in the morphodynamic development of deltas under pressure. Emerging insights into tidal controls on river delta morphology suggest that--despite the active morphodynamics in tidal channels and mouth bar regions--tidal motion acts to stabilize delta morphology at the landscape scale under the condition that sediment import during low flows largely balances sediment export during high flows. Distributary channels subject to tides show lower migration rates and are less easily flooded by the river because of opposing non-linear interactions between river discharge and the tide. These interactions lead to flow changes within channels, and a more uniform distribution of discharge across channels. Sediment depletion and rigorous human interventions in deltas, including storm surge defence works, disrupt the dynamic morphological equilibrium and can lead to erosion and severe scour at the channel bed, even decades after an intervention.

Climate of the Frank Church-River of No Return Wilderness, central Idaho

Treesearch

Arnold I. Finklin

1988-01-01

Describes the climate of the largest designated wilderness in the conterminous United States. Contains numerous maps, graphs, and tables. Shows annual patterns and 10-day details during the fire season. Includes both average values and frequency distributions. Examines relationship of climatic averages to topography, persistence of weather, and climatic trends.

Pollutant fate and spatio-temporal variability in the choptank river estuary: factors influencing water quality

USDA-ARS?s Scientific Manuscript database

Restoration of the Chesapeake Bay, a national treasure and the largest estuary in the United States, is a national priority, and documentation of progress of this restoration effort is needed. A study was conducted to examine water quality conditions in a tributary of the Chesapeake, the Choptank R...

City of Boise, Idaho Municipal Forest Resource Analysis

Treesearch

P.J. Peper; E.G. McPherson; J.R. Simpson; S.L. Gardner; K.E. Vargas; Q. Xiao

2007-01-01

Boise, the capital and largest city in the state of Idaho, maintains parks and street trees as an integral component of the urban infrastructure (Figure 1). Located along the Boise River and nestled against foothills of the Rocky Mountains, Boise is renowned for its unique blend of natural beauty and urban comforts.

Impacts of stormwater runoff in the Southern California Bight: Relationships among plume constituents

USGS Publications Warehouse

Reifel, K.M.; Johnson, S.C.; DiGiacomo, P.M.; Mengel, M.J.; Nezlin, N.P.; Warrick, J.A.; Jones, B.H.

2009-01-01

The effects from two winter rain storms on the coastal ocean of the Southern California Bight were examined as part of the Bight '03 program during February 2004 and February-March 2005. The impacts of stormwater from fecal indicator bacteria, water column toxicity, and nutrients were evaluated for five major river discharges: the Santa Clara River, Ballona Creek, the San Pedro Shelf (including the Los Angeles, San Gabriel, and Santa Ana Rivers), the San Diego River, and the Tijuana River. Exceedances of bacterial standards were observed in most of the systems. However, the areas of impact were generally spatially limited, and contaminant concentrations decreased below California Ocean Plan standards typically within 2-3 days. The largest bacterial concentrations occurred in the Tijuana River system where exceedances of fecal indicator bacteria were noted well away from the river mouth. Maximum nitrate concentrations (~40 ??M) occurred in the San Pedro Shelf region near the mouth of the Los Angeles River. Based on the results of general linear models, individual sources of stormwater differ in both nutrient concentrations and the concentration and composition of fecal indicator bacteria. While nutrients appeared to decrease in plume waters due to simple mixing and dilution, the concentration of fecal indicator bacteria in plumes depends on more than loading and dilution rates. The relationships between contaminants (nutrients and fecal indicator bacteria) and plume indicators (salinity and total suspended solids) were not strong indicating the presence of other potentially important sources and/or sinks of both nutrients and fecal indicator bacteria. California Ocean Plan standards were often exceeded in waters containing greater than 10% stormwater (<28-30 salinity range). The median concentration dropped below the standard in the 32-33 salinity range (1-4% stormwater) for total coliforms and Enterococcus spp. and in the 28-30 salinity range (10-16% stormwater) for fecal coliforms. Nutrients showed a similar pattern with the highest median concentrations in water with greater than 10% stormwater. Relationships between colored dissolved organic matter (CDOM) and salinity and between total suspended solids and beam attenuation indicate that readily measurable, optically active variables can be used as proxies to provide at least a qualitative, if not quantitative, evaluation of the distribution of the dissolved, as well as the particulate, components of stormwater plumes. In this context, both CDOM absorption and the beam attenuation coefficient can be derived from satellite ocean color measurements of inherent optical properties suggesting that remote sensing of ocean color should be useful in mapping the spatial areas and durations of impacts from these contaminants. ?? 2009 Elsevier Ltd.

Impacts of stormwater runoff in the Southern California Bight: Relationships among plume constituents

NASA Astrophysics Data System (ADS)

Reifel, Kristen M.; Johnson, Scott C.; DiGiacomo, Paul M.; Mengel, Michael J.; Nezlin, Nikolay P.; Warrick, Jonathan A.; Jones, Burton H.

2009-08-01

The effects from two winter rain storms on the coastal ocean of the Southern California Bight were examined as part of the Bight '03 program during February 2004 and February-March 2005. The impacts of stormwater from fecal indicator bacteria, water column toxicity, and nutrients were evaluated for five major river discharges: the Santa Clara River, Ballona Creek, the San Pedro Shelf (including the Los Angeles, San Gabriel, and Santa Ana Rivers), the San Diego River, and the Tijuana River. Exceedances of bacterial standards were observed in most of the systems. However, the areas of impact were generally spatially limited, and contaminant concentrations decreased below California Ocean Plan standards typically within 2-3 days. The largest bacterial concentrations occurred in the Tijuana River system where exceedances of fecal indicator bacteria were noted well away from the river mouth. Maximum nitrate concentrations (~40 μM) occurred in the San Pedro Shelf region near the mouth of the Los Angeles River. Based on the results of general linear models, individual sources of stormwater differ in both nutrient concentrations and the concentration and composition of fecal indicator bacteria. While nutrients appeared to decrease in plume waters due to simple mixing and dilution, the concentration of fecal indicator bacteria in plumes depends on more than loading and dilution rates. The relationships between contaminants (nutrients and fecal indicator bacteria) and plume indicators (salinity and total suspended solids) were not strong indicating the presence of other potentially important sources and/or sinks of both nutrients and fecal indicator bacteria. California Ocean Plan standards were often exceeded in waters containing greater than 10% stormwater (<28-30 salinity range). The median concentration dropped below the standard in the 32-33 salinity range (1-4% stormwater) for total coliforms and Enterococcus spp. and in the 28-30 salinity range (10-16% stormwater) for fecal coliforms. Nutrients showed a similar pattern with the highest median concentrations in water with greater than 10% stormwater. Relationships between colored dissolved organic matter (CDOM) and salinity and between total suspended solids and beam attenuation indicate that readily measurable, optically active variables can be used as proxies to provide at least a qualitative, if not quantitative, evaluation of the distribution of the dissolved, as well as the particulate, components of stormwater plumes. In this context, both CDOM absorption and the beam attenuation coefficient can be derived from satellite ocean color measurements of inherent optical properties suggesting that remote sensing of ocean color should be useful in mapping the spatial areas and durations of impacts from these contaminants.

[Variation characteristics and influencing factors of actual evapotranspiration under various vegetation types: A case study in the Huaihe River Basin, China.

PubMed

Wu, Rong Jun; Xing, Xiao Yong

2016-06-01

The actual evapotranspiration was modelled utilizing the boreal ecosystem productivity simulator (BEPS) in Huaihe River Basin from 2001 to 2012. In the meantime, the quantitative analyses of the spatial-temporal variations of actual evapotranspiration characteristics and its influencing factors under different vegetation types were conducted. The results showed that annual evapotranspiration gradually decreased from southeast to northwest, tended to increase annually, and the monthly change for the average annual evapotranspiration was double-peak curve. The differences of evapotranspiration among vegetation types showed that the farmland was the largest contributor for the evapotranspiration of Huaihe Basin. The annual actual evapotranspiration of the mixed forest per unit area was the largest, and that of the bare ground per unit area was the smallest. The changed average annual evapotranspiration per unit area for various vegetation types indicated an increased tendency other than the bare ground, with a most significant increase trend for the evergreen broadleaf forest. The thermodynamic factors (such as average temperature) were the dominant factors affecting the actual evapotranspiration in the Huaihe Basin, followed by radiation and moisture factors.

Divergent biophysical controls of aquatic CO2 and CH4 in the World's two largest rivers.

PubMed

Borges, Alberto V; Abril, Gwenaël; Darchambeau, François; Teodoru, Cristian R; Deborde, Jonathan; Vidal, Luciana O; Lambert, Thibault; Bouillon, Steven

2015-10-23

Carbon emissions to the atmosphere from inland waters are globally significant and mainly occur at tropical latitudes. However, processes controlling the intensity of CO2 and CH4 emissions from tropical inland waters remain poorly understood. Here, we report a data-set of concurrent measurements of the partial pressure of CO2 (pCO2) and dissolved CH4 concentrations in the Amazon (n = 136) and the Congo (n = 280) Rivers. The pCO2 values in the Amazon mainstem were significantly higher than in the Congo, contrasting with CH4 concentrations that were higher in the Congo than in the Amazon. Large-scale patterns in pCO2 across different lowland tropical basins can be apprehended with a relatively simple statistical model related to the extent of wetlands within the basin, showing that, in addition to non-flooded vegetation, wetlands also contribute to CO2 in river channels. On the other hand, dynamics of dissolved CH4 in river channels are less straightforward to predict, and are related to the way hydrology modulates the connectivity between wetlands and river channels.

Detection and Quantification of Inorganic and Organic Anions in Natural, Potable, and Wastewaters in Northern New York Using Capillary Zone Electrophoresis and Indirect UV Detection

PubMed Central

Varden, Lara; Smith, Britannia; Bou-Abdallah, Fadi

2017-01-01

Capillary zone electrophoresis (CZE) is a sensitive and rapid technique used for determining traces of inorganic and organic anions in potable, natural, and wastewaters. Here, CZE with indirect UV-diode array detection (CZE-DAD) was employed with a background electrolyte system comprising of an Agilent Technologies proprietary basic anion buffer at pH 12.0 and a forensic anion detection method. The limits of detection (LOD) for this method ranged between 3 and 5 ppm and involved hydrodynamic injection of 50 mbar for 6 s with a negative polarity separation voltage of −30 kV at 30°C, a detection wavelength of 350 nm and indirect reference of 275 nm. Fourteen different anions were checked for in the water samples that were examined and included bromide, chloride, thiosulfate, nitrate, nitrite, sulfate, azide, carbonate, fluoride, arsenate, phosphate, acetate, lactate, and silicate. The water samples were collected from Northern New York towns and the Raquette River water system, the third longest river in New York State and the largest watershed of the central and western Adirondacks. The concentrations detected for these anions ranged from <5.0 ppm to 260 ppm. PMID:29057145

First record of epizootic ulcerative syndrome from the Upper Congo catchment: An outbreak in the Bangweulu swamps, Zambia.

PubMed

Huchzermeyer, C F; Huchzermeyer, K D A; Christison, K W; Macey, B M; Colly, P A; Hang'ombe, B M; Songe, M M

2018-01-01

We report on the first outbreak of epizootic ulcerative syndrome (EUS) amongst wild fish populations in the Bangweulu swamps, an inland delta, in the north of Zambia during 2014. The area supports a large and diverse fish fauna related to, but distinct from, that of the Zambezi River system where EUS outbreaks have occurred since 2006. A sizeable artisanal fishery, based on extensive fish weirs, is sustained by the annual flooding of the swamps, and observations of the disease outbreak by fishermen were recorded. Signs typical of infection with Aphanomyces invadans were observed in a number of species. Clinical observations, histology and molecular diagnostic methods were used to confirm infection with A. invadans in two of the most commonly and severely affected species. Several features of the wetland may have contributed to the outbreak and the annual recurrence of the disease. Modes by which the disease may have been introduced into the swamps are discussed. The outbreak is of great significance as the Bangweulu swamps drain into the Congo River in neighbouring Democratic Republic of Congo, Africa's largest drainage system with an extensive and diverse fish fauna previously unaffected by EUS. © 2017 John Wiley & Sons Ltd.

A legacy of change: The lower Colorado River, Arizona-California-Nevada, USA, and Sonora-Baja California Norte, Mexico

USGS Publications Warehouse

Mueller, G.A.; Marsh, P.C.; Minckley, W.L.

2005-01-01

The lower Colorado is among the most regulated rivers in the world. It ranks as the fifth largest river in volume in the coterminous United States, but its flow is fully allocated and no longer reaches the sea. Lower basin reservoirs flood nearly one third of the river channel and store 2 years of annual flow. Diverted water irrigates 1.5 million ha of cropland and provides water for industry and domestic use by 22 million people in the southwestern United States and northern Mexico. The native fish community of the lower Colorado River was among the most unique in the world, and the main stem was home to nine freshwater species, all of which were endemic to the basin. Today, five are extirpated, seven are federally endangered, and three are being reintroduced through stocking. Decline of the native fauna is attributed to predation by nonnative fishes and physical habitat degradation. Nearly 80 alien species have been introduced, and more than 20 now are common. These nonnative species thrived in modified habitats, where they largely eliminated the native kinds. As a result, the lower Colorado River has the dubious distinction of being among the few major rivers of the world with an entirely introduced fish fauna. ?? 2005 by the American Fisheries Society.