Aquatic habitat measurement and valuation: imputing social benefits to instream flow levels

USGS Publications Warehouse

Douglas, Aaron J.; Johnson, Richard L.

1991-01-01

Instream flow conflicts have been analysed from the perspectives offered by policy oriented applied (physical) science, theories of conflict resolution and negotiation strategy, and psychological analyses of the behavior patterns of the bargaining parties. Economics also offers some useful insights in analysing conflict resolution within the context of these water allocation problems. We attempt to analyse the economics of the bargaining process in conjunction with a discussion of the water allocation process. In particular, we examine in detail the relation between certain habitat estimation techniques, and the socially optimal allocation of non-market resources. The results developed here describe the welfare implications implicit in the contemporary general equilibrium analysis of a competitive market economy. We also review certain currently available techniques for assigning dollar values to the social benefits of instream flow. The limitations of non-market valuation techniques with respect to estimating the benefits provided by instream flows and the aquatic habitat contingent on these flows should not deter resource managers from using economic analysis as a basic tool for settling instream flow conflicts.

Simulation of groundwater flow and streamflow depletion in the Branch Brook, Merriland River, and parts of the Mousam River watersheds in southern Maine

USGS Publications Warehouse

Nielsen, Martha G.; Locke, Daniel B.

2015-01-01

The study evaluated two different methods of calculating in-stream flow requirements for Branch Brook and the Merriland River—a set of statewide equations used to calculate monthly median flows and the MOVE.1 record-extension technique used on site-specific streamflow measurements. The August median in-stream flow requirement in the Merriland River was calculated as 7.18 ft3/s using the statewide equations but was 3.07 ft3/s using the MOVE.1 analysis. In Branch Brook, the August median in-stream flow requirements were calculated as 20.3 ft3/s using the statewide equations and 11.8 ft3/s using the MOVE.1 analysis. In each case, using site-specific data yields an estimate of in-stream flow that is much lower than an estimate the statewide equations provide.

A method of estimating in-stream residence time of water in rivers

NASA Astrophysics Data System (ADS)

Worrall, F.; Howden, N. J. K.; Burt, T. P.

2014-05-01

This study develops a method for estimating the average in-stream residence time of water in a river channel and across large catchments, i.e. the time between water entering a river and reaching a downstream monitoring point. The methodology uses river flow gauging data to integrate Manning's equation along a length of channel for different percentile flows. The method was developed and tested for the River Tees in northern England and then applied across the United Kingdom (UK). The study developed methods to predict channel width and main channel length from catchment area. For an 818 km2 catchment with a channel length of 79 km, the in-stream residence time at the 50% exceedence flow was 13.8 h. The method was applied to nine UK river basins and the results showed that in-stream residence time was related to the average slope of a basin and its average annual rainfall. For the UK as a whole, the discharge-weighted in-stream residence time was 26.7 h for the median flow. At median flow, 50% of the discharge-weighted in-stream residence time was due to only 6 out of the 323 catchments considered. Since only a few large rivers dominate the in-stream residence time, these rivers will dominate key biogeochemical processes controlling export at the national scale. The implications of the results for biogeochemistry, especially the turnover of carbon in rivers, are discussed.

Opportunities to protect instream flows in Colorado and Wyoming

USGS Publications Warehouse

Trembly, Terrence L.

1987-01-01

This document combines the efforts of several individuals, agencies, and organizations toward a common objective: the identification, description, and preliminary evaluation of promising opportunities for protecting instream uses of water under existing laws in Colorado and Wyoming. This report is intended for the use of State and Federal planning and management personnel who need an overview of potential opportunities for preserving instream flows. It is not intended to replace or challenge the advice of agency counsel, nor it is written to provide legal advice. Instead, it is designed as a guide for the person trying to find his or her way among sometimes bewildering State statues and administrative practices. This report is not, and should not be taken as, official policy or prediction of future actions by any agency. It is simply a summary of some potential opportunities for protecting instream uses. Toward these objectives, the U.S. Fish and Wildlife Service, through its Water Resources Analysis Project, contracted in 1977 with Richard Dewsnup and Dallin Jensen to identify available strategies under State and Federal laws, interstate compacts, and water quality laws. A second firm, Enviro Control, Inc., was contracted to evaluate the most promising strategies. Two of the resulting documents were Instream Flow Strategies for Colorado and Instream Flow Strategies for Wyoming, which have been revised, updated, and combined in this report. Discussion of instream flow programs ad opportunities for each State--Colorado and Wyoming-- are written so that each report can be read independently, with minimal cross referencing from one State report to another.

Quantifying Channel Maintenance Instream Flows: An Approach for Gravel-Bed Streams in the Western United States

Treesearch

Larry J. Schmidt; John P. Potyondy

2004-01-01

This paper discusses one approach for quantifying channel maintenance instream flow necessary to achieve the Forest Service Organic Act purpose of securing favorable conditions of water flows. The approach is appropriate for quantifying channel maintenance flows on perennial, unregulated, snowmelt-dominated, gravel-bed streams with alluvial reaches. The approach...

A demonstration of the instream flow incremental methodology, Shenandoah River

USGS Publications Warehouse

Zappia, Humbert; Hayes, Donald C.

1998-01-01

Current and projected demands on the water resources of the Shenandoah River have increased concerns for the potential effect of these demands on the natural integrity of the Shenandoah River system. The Instream Flow Incremental Method (IFIM) process attempts to integrate concepts of water-supply planning, analytical hydraulic engineering models, and empirically derived habitat versus flow functions to address water-use and instream-flow issues and questions concerning life-stage specific effects on selected species and the general well being of aquatic biological populations.The demonstration project also sets the stage for the identification and compilation of the major instream-flow issues in the Shenandoah River Basin, development of the required multidisciplinary technical team to conduct more detailed studies, and development of basin specific habitat and flow requirements for fish species, species assemblages, and various water uses in the Shenandoah River Basin. This report presents the results of an IFIM demonstration project, conducted on the main stem Shenandoah River in Virginia, during 1996 and 1997, using the Physical Habitat Simulation System (PHABSIM) model.Output from PHABSIM is used to address the general flow requirements for water supply and recreation and habitat for selected life stages of several fish species. The model output is only a small part of the information necessary for effective decision making and management of river resources. The information by itself is usually insufficient for formulation of recommendations regarding instream-flow requirements. Additional information, for example, can be obtained by analysis of habitat time-series data, habitat duration data, and habitat bottlenecks. Alternative-flow analysis and habitat-duration curves are presented.

Native fishes in the Truckee River: Are in-stream structures and patterns of population genetic structure related?

PubMed

Peacock, Mary M; Gustin, Mae S; Kirchoff, Veronica S; Robinson, Morgan L; Hekkala, Evon; Pizzarro-Barraza, Claudia; Loux, Tim

2016-09-01

In-stream structures are recognized as significant impediments to movement for freshwater fishes. Apex predators such as salmonids have been the focus of much research on the impacts of such barriers to population dynamics and population viability however much less research has focused on native fishes, where in-stream structures may have a greater impact on long term population viability of these smaller, less mobile species. Patterns of genetic structure on a riverscape can provide information on which structures represent real barriers to movement for fish species and under what specific flow conditions. Here we characterize the impact of 41 dam and diversion structures on movement dynamics under varying flow conditions for a suite of six native fishes found in the Truckee River of California and Nevada. Microsatellite loci were used to estimate total allelic diversity, effective population size and assess genetic population structure. Although there is spatial overlap among species within the river there are clear differences in species distributions within the watershed. Observed population genetic structure was associated with in-stream structures, but only under low flow conditions. High total discharge in 2006 allowed fish to move over potential barriers resulting in no observed population genetic structure for any species in 2007. The efficacy of in-stream structures to impede movement and isolate fish emerged only after multiple years of low flow conditions. Our results suggest that restricted movement of fish species, as a result of in-stream barriers, can be mitigated by flow management. However, as flow dynamics are likely to be altered under global climate change, fragmentation due to barriers could isolate stream fishes into small subpopulations susceptible to both demographic losses and losses of genetic variation. Copyright © 2016 Elsevier B.V. All rights reserved.

Use of the instream flow incremental methodology: a tool for negotiation

USGS Publications Warehouse

Cavendish, Mary G.; Duncan, Margaret I.

1986-01-01

The resolution of conflicts arising from differing values and water uses requires technical information and negotiating skills. This article outlines the Instream Flow Incremental Methodology (IFIM), developed by the US Fish and Wildlife Service, and demonstrates that its use to quantify flows necessary to protect desired instream values aids negotiation by illustrating areas of agreement and possible compromises between conflicting water interests. Pursuant to a Section 404 permit application to the US Army Corps of Engineers made by City Utilities of Springfield, Missouri, in 1978, IFIM provided the means by which City Utilities, concerned with a secure water supply for a growing population, and those advocating instream values were satisfied that their requirements were met. In tracing the 15-month process, the authors conclude that the application of IFIM, as well as the cooperative stance adopted by the parties involved, were the key ingredients of the successful permit application.

Characterizing and contrasting instream and riparian coarse wood in western Montana basins

Treesearch

Michael K. Young; Ethan A. Mace; Eric T. Ziegler; Elaine K. Sutherland

2006-01-01

The importance of coarse wood to aquatic biota and stream channel structure is widely recognized, yet characterizations of large-scale patterns in coarse wood dimensions and loads are rare. To address these issues, we censused instream coarse wood ( 2 m long and 10 cm minimum diameter) and sampled riparian coarse wood and channel characteristics in and along 13 streams...

Instream flow assessment and economic valuation: a survey of nonmarket benefits research

USGS Publications Warehouse

Douglas, Aaron J.; Johnson, Richard L.

1993-01-01

Instream flow benefits for United States streams and rivers have recently been investigated by a number of resource economists. These valuation efforts differ in scope, method, and quantitative results. An assessment and review of these valuation efforts is presented. The various sources of differences in non‐market values produced by these studies are explored in some detail. The considerable difficulty of producing estimates of instream flow benefits values that consider all of the pertinent policy and technical issues is delineated in various policy contexts. Evidence is presented that indicates that the considerable policy impact of recent research on this topic is justified despite considerable variation in the magnitude of the estimates.

InSTREAM: the individual-based stream trout research and environmental assessment model

Treesearch

Steven F. Railsback; Bret C. Harvey; Stephen K. Jackson; Roland H. Lamberson

2009-01-01

This report documents Version 4.2 of InSTREAM, including its formulation, software, and application to research and management problems. InSTREAM is a simulation model designed to understand how stream and river salmonid populations respond to habitat alteration, including altered flow, temperature, and turbidity regimes and changes in channel morphology. The model...

Opportunities to protect instream flows and wetland uses of water in Florida

USGS Publications Warehouse

Burkardt, Nina

1990-01-01

This document combines the efforts of several individuals, agencies, and organizations toward a common objective: the identification, description, and preliminary evaluation of promising opportunities for protecting instream uses of water under existing laws in Florida. this report is intended for the use of State and Federal planning and management personnel who need an overview of potential opportunities for preserving instream flows. It is not intended to replace or challenge the advice of agency counsel, nor is it written to provide legal advice. Instead, it is designed as a guide for the person trying to find his way among sometimes bewildering State statutes and administrative practices. This report is not, and should not be taken as, official policy or prediction of future actions by any agency. It is simply a summary of some potential opportunities for protecting instream uses. Toward these objectives, the U.S. Fish and Wildlife Service, through its Water Resource Analysis Project, contracted in 1977 with R. Dewsnup and D. Jensen to identify available strategies under State and Federal laws, interstate compacts, and water quality laws. A second firm, Enviro Control, Inc., was contracted to evaluate the most promising strategies. The resulting documents reported instream flow strategies for 11 States. These reports have been revised, updated, and combined in a number of new monographs, and the Service has added more States to this service over the years. The discussion of instream flow programs and opportunities for each State is written so that each report can be read independently, with minimal cross-referencing from one State report to another. The opportunities for Florida are summarized in the table.

Instream water use in the United States: water laws and methods for determining flow requirements

USGS Publications Warehouse

Lamb, Berton L.; Doerksen, Harvey R.

1987-01-01

Water use generally is divided into two primary classes - offstream use and instream use. In offstream use, sometimes called out-of-stream or diversionary use, water is withdrawn (diverted) from a stream or aquifer and transported to the place of use. Examples are irrigated agriculture, municipal water supply, and industrial use. Each of these offstream uses, which decreases the volume of water available downstream from the point of diversion, is discussed in previous articles in this volume. Instream use, which generally does not diminish the flow downstream from its point of use, and its importance are described in this article. One of the earliest instream uses of water in the United States was to turn the water wheels that powered much of the Nation's industry in the 18th and 19th centuries. Although a small volume of water might have been diverted to a mill near streamside, that water usually was returned to the stream near the point of diversion and, thus, the flow was not diminished downstream from the mill. Over time, the generation of hydroelectric power replaced mill wheels as a means of converting water flow into energy. Since the 1920's, the generation of hydroelectric power increasingly has become a major instream use of water. By 1985, more than 3 billion acre-feet of water (3,050,000 million gallons per day) was used annually for hydropower generation (Solley and others, 1988, p. 45)-enough water to cover the State of Colorado to a depth of 51 feet. Navigation is another instream use with a long history. The Lewis and Clark expedition journals and many of Mark Twain's novels illustrate the extent to which the Nation originally depended on adequate streamfiows for basic transportation. Navigation in the 1980's is still considered to be an instream use; however, it often is based upon a stream system that has been modified greatly through channelization, diking, and construction of dams and locks. The present (1987) inland water navigation system in the conterminous United States consists of about 12,000 miles of maintained waterways, over which about 500 million tons of cargo is carried each year (U.S. Army Corps of Engineers, 1988, p. 16). Although not so widely practiced in recent years, streams have been used to dispose of raw waste products from homes, communities, and factories. This use has been discouraged by law and public policy because of public health concerns and the damage it causes to the environment. Beginning in the mid-1960's, other instream uses gained new prominence in the water-resources arena-the assertion of a legal right to a free-flowing stream for biological, recreational, and esthetic purposes. These uses themselves, however, are not new. Riverine habitat always has produced fish, and the beauty of flowing water always has evoked a strong sense of esthetic appreciation. What is new is the emerging legitimacy and awareness of these noneconomic uses under State and Federal laws and regulations. In the past, environmental uses of flowing water were ignored, for the most part, under a long-standing legal tradition that favored offstream uses and certain instream uses that had a strong economic basis. The history of instream-flow policy debate really concerns those recently recognized types of interim uses. Although the more transitional water uses have been protected by law, the recognition of other in stream uses has resulted in substantial changes in State water laws. Although methods for determining the volume of water needed for most traditional water uses are relatively straight-forward and well-established, methods for determining water requirements for the in stream uses have been developed only recently and are continuing to evolve. Water laws that have favored the more traditional water uses, the inherent nature of conflict between instream and offstream water uses, and the special kinds of technological and philosophical problems posed by the "newer" types of instream uses are described below. Water laws that have been passed to accommodate the more recently recognized instream uses are summarized.

Valuing instream-related services of wastewater

EPA Science Inventory

In the southwestern US water resources are increasingly scarce, leaving perennial habitats and associated environmental amenities vulnerable to off-channel water demands. To provide management insight, the value of two instream flow related ecosystem services are estimated for tw...

Field testing and adaptation of a methodology to measure "in-stream" values in the Tongue River, northern Great Plains (NGP) region

USGS Publications Warehouse

Bovee, Ken D.; Gore, James A.; Silverman, Arnold J.

1978-01-01

A comprehensive, multi-component in-stream flow methodology was developed and field tested in the Tongue River in southeastern Montana. The methodology incorporates a sensitivity for the flow requirements of a wide variety of in-stream uses, and the flexibility to adjust flows to accommodate seasonal and sub-seasonal changes in the flow requirements for different areas. In addition, the methodology provides the means to accurately determine the magnitude of the water requirement for each in-stream use. The methodology can be a powerful water management tool in that it provides the flexibility and accuracy necessary in water use negotiations and evaluation of trade-offs. In contrast to most traditional methodologies, in-stream flow requirements were determined by additive independent methodologies developed for: 1) fisheries, including spawning, rearing, and food production; 2) sediment transport; 3) the mitigation of adverse impacts of ice; and 4) evapotranspiration losses. Since each flow requirement varied in important throughout the year, the consideration of a single in-stream use as a basis for a flow recommendation is inadequate. The study shows that the base flow requirement for spawning shovelnose sturgeon was 13.0 m3/sec. During the same period of the year, the flow required to initiate the scour of sediment from pools is 18.0 m3/sec, with increased scour efficiency occurring at flows between 20.0 and 25.0 m3/sec. An over-winter flow of 2.83 m3/sec. would result in the loss of approximately 80% of the riffle areas to encroachment by surface ice. At the base flow for insect production, approximately 60% of the riffle area is lost to ice. Serious damage to the channel could be incurred from ice jams during the spring break-up period. A flow of 12.0 m3/sec. is recommended to alleviate this problem. Extensive ice jams would be expected at the base rearing and food production levels. The base rearing flow may be profoundly influenced by the loss of streamflow to transpiration. Transpiration losses to riparian vegetation ranged from 0.78 m3/sec. in April, to 1.54 m3/sec. in July, under drought conditions. Requirement for irrigation were estimated to range from 5.56 m3/sec. in May to 7.97 m3/sec. in July, under drought conditions. It was concluded that flow requirements to satisfy monthly water losses to transpiration must be added to the base fishery flows to provide adequate protection to the resources in the lower reaches of the river. Integration of the in-stream requirements for various use components shows that a base flow of at least 23.6 m3/sec. must be reserved during the month of June to initiate scour of sediment from pools, provide spawning habitat to shovelnose sturgeon, and to accommodate water losses from the system. In comparison, a base flow of 3.85 m3/sec. would be required during early February to provide fish rearing habitat and insect productivity, and to prevent excessive loss of food production areas to surface ice formation. During mid to late February, a flow of 12 m3/sec. would be needed to facilitate ice break-up and prevent ice jams from forming. Following break-up, the base flow would again be 3.85 m3/sec. until the start of spawning season.

Economic Value of Instream Flow for Non-Commercial Whitewater Boating Using Recreation Demand and Contingent Valuation Methods

NASA Astrophysics Data System (ADS)

Loomis, John; McTernan, James

2014-03-01

Whitewater river kayaking and river rafting require adequate instream flows that are often adversely affected by upstream water diversions. However, there are very few studies in the USA of the economic value of instream flow to inform environmental managers. This study estimates the economic value of instream flow to non-commercial kayakers derived using a Travel Cost Method recreation demand model and Contingent Valuation Method (CVM), a type of Contingent Behavior Method (CBM). Data were obtained from a visitor survey administered along the Poudre River in Colorado. In the dichotomous choice CVM willingness to pay (WTP) question, visitors were asked if they would still visit the river if the cost of their trip was Y higher, and the level of Y was varied across the sample. The CVM yielded an estimate of WTP that was sensitive to flows ranging from 55 per person per day at 300 Cubic Feet per Second (CFS) to a maximum 97 per person per day at flows of 1900 CFS. The recreation demand model estimated a boater's number of trips per season. We found the number of trips taken was also sensitive to flow, ranging from as little as 1.63 trips at 300 CFS to a maximum number of 14 trips over the season at 1900 CFS. Thus, there is consistency between peak benefits per trip and number of trips, respectively. With an average of about 100 non-commercial boaters per day, the maximum marginal values per acre foot averages about 220. This value exceeds irrigation water values in this area of Colorado.

3D Numerical simulation of bed morphological responses to complex in-streamstructures

NASA Astrophysics Data System (ADS)

Xu, Y.; Liu, X.

2017-12-01

In-stream structures are widely used in stream restoration for both hydraulic and ecologicalpurposes. The geometries of the structures are usually designed to be extremely complex andirregular, so as to provide nature-like physical habitat. The aim of this study is to develop anumerical model to accurately predict the bed-load transport and the morphological changescaused by the complex in-stream structures. This model is developed in the platform ofOpenFOAM. In the hydrodynamics part, it utilizes different turbulence models to capture thedetailed turbulence information near the in-stream structures. The technique of immersedboundary method (IBM) is efficiently implemented in the model to describe the movable bendand the rigid solid body of in-stream structures. With IBM, the difficulty of mesh generation onthe complex geometry is greatly alleviated, and the bed surface deformation is able to becoupled in to flow system. This morphodynamics model is firstly validated by simple structures,such as the morphology of the scour in log-vane structure. Then it is applied in a more complexstructure, engineered log jams (ELJ), which consists of multiple logs piled together. Thenumerical results including turbulence flow information and bed morphological responses areevaluated against the experimental measurement within the exact same flow condition.

The design of water markets when instream flows have value.

PubMed

Murphy, James J; Dinar, Ariel; Howitt, Richard E; Rassenti, Stephen J; Smith, Vernon L; Weinberg, Marca

2009-02-01

The main objective of this paper is to design and test a decentralized exchange mechanism that generates the location-specific pricing necessary to achieve efficient allocations in the presence of instream flow values. Although a market-oriented approach has the potential to improve upon traditional command and control regulations, questions remain about how these rights-based institutions can be implemented such that the potential gains from liberalized trade can be realized. This article uses laboratory experiments to test three different water market institutions designed to incorporate instream flow values into the allocation mechanism through active participation of an environmental trader. The smart, computer-coordinated market described herein offers the potential to significantly reduce coordination problems and transaction costs associated with finding mutually beneficial trades that satisfy environmental constraints. We find that direct environmental participation in the market can achieve highly efficient and stable outcomes, although the potential does exist for the environmental agent to influence outcomes.

Evaluation of ecological instream flow considering hydrological alterations in the Yellow River basin, China

NASA Astrophysics Data System (ADS)

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

2018-01-01

The Yellow River is the second largest river in China and is the important source for water supply in the northwestern and northern China. It is often regarded as the mother river of China. Owing to climatic change and intensifying human activities, such as increasing withdrawal of water for meeting growing agricultural irrigation needs since 1986, the flow of Yellow River has decreased, with serious impacts on the ecological environment. Using multiple hydrological indicators and Flow Duration Curve (DFC)-based ecodeficit and ecosurplus, this study investigates the impact of hydrological alterations, such as the impact of water reservoirs or dams, on downstream ecological instream flow. Results indicate that: (1) due to the impoundment and hydrological regulations of water reservoirs, occurrence rates and magnitudes of high flow regimes have decreased and the decrease is also found in the magnitudes of low flow events. These changes tend to be more evident from the upper to the lower Yellow River basin; (2) human activities tend to enhance the instream flow variability, particularly after the 1980s;(3) the ecological environment in different parts of the Yellow River basin is under different degrees of ecological risk. In general, lower to higher ecological risk can be detected due to hydrological alterations from the upper to the lower Yellow River basin. This shows that conservation of ecological environment and river health is facing a serious challenge in the lower Yellow River basin; (4) ecological instream flow indices, such as ecodeficit and ecosurplus, and IHA32 hydrological indicators are in strong relationships, suggesting that ecodeficit and ecosurplus can be regarded as appropriate ecological indicators for developing measures for mitigating the adverse impact of human activities on the conservation of ecological environment in the Yellow River basin.

A computer program for estimating instream travel times and concentrations of a potential contaminant in the Yellowstone River, Montana

USGS Publications Warehouse

McCarthy, Peter M.

2006-01-01

The Yellowstone River is very important in a variety of ways to the residents of southeastern Montana; however, it is especially vulnerable to spilled contaminants. In 2004, the U.S. Geological Survey, in cooperation with Montana Department of Environmental Quality, initiated a study to develop a computer program to rapidly estimate instream travel times and concentrations of a potential contaminant in the Yellowstone River using regression equations developed in 1999 by the U.S. Geological Survey. The purpose of this report is to describe these equations and their limitations, describe the development of a computer program to apply the equations to the Yellowstone River, and provide detailed instructions on how to use the program. This program is available online at [http://pubs.water.usgs.gov/sir2006-5057/includes/ytot.xls]. The regression equations provide estimates of instream travel times and concentrations in rivers where little or no contaminant-transport data are available. Equations were developed and presented for the most probable flow velocity and the maximum probable flow velocity. These velocity estimates can then be used to calculate instream travel times and concentrations of a potential contaminant. The computer program was developed so estimation equations for instream travel times and concentrations can be solved quickly for sites along the Yellowstone River between Corwin Springs and Sidney, Montana. The basic types of data needed to run the program are spill data, streamflow data, and data for locations of interest along the Yellowstone River. Data output from the program includes spill location, river mileage at specified locations, instantaneous discharge, mean-annual discharge, drainage area, and channel slope. Travel times and concentrations are provided for estimates of the most probable velocity of the peak concentration and the maximum probable velocity of the peak concentration. Verification of estimates of instream travel times and concentrations for the Yellowstone River requires information about the flow velocity throughout the 520 mi of river in the study area. Dye-tracer studies would provide the best data about flow velocities and would provide the best verification of instream travel times and concentrations estimated from this computer program; however, data from such studies does not currently (2006) exist and new studies would be expensive and time-consuming. An alternative approach used in this study for verification of instream travel times is based on the use of flood-wave velocities determined from recorded streamflow hydrographs at selected mainstem streamflow-gaging stations along the Yellowstone River. The ratios of flood-wave velocity to the most probable velocity for the base flow estimated from the computer program are within the accepted range of 2.5 to 4.0 and indicate that flow velocities estimated from the computer program are reasonable for the Yellowstone River. The ratios of flood-wave velocity to the maximum probable velocity are within a range of 1.9 to 2.8 and indicate that the maximum probable flow velocities estimated from the computer program, which corresponds to the shortest travel times and maximum probable concentrations, are conservative and reasonable for the Yellowstone River.

Instream wood loads in montane forest streams of the Colorado Front Range, USA

NASA Astrophysics Data System (ADS)

Jackson, Karen J.; Wohl, Ellen

2015-04-01

Although several studies examine instream wood loads and associated geomorphic effects in streams of subalpine forests in the U.S. Southern Rocky Mountains, little is known of instream wood loads in lower elevation, montane forests of the region. We compare instream wood loads and geomorphic effects between streams draining montane forest stands of differing age (old growth versus younger) and disturbance history (healthy versus infested by mountain pine beetles). We examined forest stand characteristics, instream wood load, channel geometry, pool volume, and sediment storage in 33 pool-riffle or plane-bed stream reaches with objectives of determining whether (i) instream wood and geomorphic effects differed significantly among old-growth, younger, healthy, and beetle-infested forest stands and (ii) wood loads correlated with valley and channel characteristics. Wood loads were standardized to drainage area, stream gradient, reach length, bankfull width, and floodplain area. Streams flowing through old-growth forests had significantly larger wood loads and logjam volumes (pairwise t-tests), as well as logjam frequencies (Kruskal-Wallis test), residual pool volume, and fine sediment storage around wood than streams flowing through younger forests. Wood loads in streams draining beetle-infested forest did not differ significantly from those in healthy forest stands, but best subset regression models indicated that elevation, stand age, and beetle infestation were the best predictors of wood loads in channels and on floodplains, suggesting that beetle infestation is affecting instream wood characteristics. Wood loads are larger than values from subalpine streams in the same region and jams are larger and more closely spaced. We interpret these differences to reflect greater wood piece mobility in subalpine zone streams. Stand age appears to exert the dominant influence on instream wood characteristics within pool-riffle streams in the study area rather than beetle infestation, although this may reflect the relatively recent nature (< 10 years) of the infestation.

Strategic planning for instream flow restoration: a case study of potential climate change impacts in the central Columbia River basin.

PubMed

Donley, Erin E; Naiman, Robert J; Marineau, Mathieu D

2012-10-01

We provide a case study prioritizing instream flow restoration activities by sub-basin according to the habitat needs of Endangered Species Act (ESA)-listed salmonids relative to climate change in the central Columbia River basin in Washington State (USA). The objective is to employ scenario analysis to inform and improve existing instream flow restoration projects. We assess the sensitivity of late summer (July, August, and September) flows to the following scenario simulations - singly or in combination: climate change, changes in the quantity of water used for irrigation and possible changes to existing water resource policy. Flows for four sub-basins were modeled using the Water Evaluation and Planning system (WEAP) under historical and projected conditions of 2020 and 2040 for each scenario. Results indicate that Yakima will be the most flow-limited sub-basin with average reductions in streamflow of 41% under climate conditions of 2020 and 56% under 2040 conditions; 1.3-2.5 times greater than those of other sub-basins. In addition, irrigation plays a key role in the hydrology of the Yakima sub-basin - with flow reductions ranging from 78% to 90% under severe to extreme (i.e., 20-40%) increases in agricultural water use (2.0-4.4 times the reductions in the other sub-basins). The Yakima and Okanogan sub-basins are the most responsive to simulations of flow-bolstering policy change (providing salmon with first priority water allocation and at biologically relevant flows), as demonstrated by 91-100% target flows attained. The Wenatchee and Methow sub-basins do not exhibit similar responsiveness to simulated policy changes. Considering climate change only, we conclude that flow restoration should be prioritized first in the Yakima and Wenatchee sub-basins, and second in the Okanogan and Methow. Considering both climate change and possible policy changes, we recommend that the Yakima sub-basin receive the highest priority for flow restoration activities to sustain critical instream habitat for ESA-listed salmonids. © 2012 Blackwell Publishing Ltd.

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.

Environmental flow studies of the Fort Collins Science Center, U.S. Geological Survey-Cherry Creek, Arizona

USGS Publications Warehouse

Waddle, Terry J.; Bovee, Ken D.

2010-01-01

At the request of the U.S. Forest Service, an instream flow assessment was conducted at Cherry Creek, Ariz., to investigate habitat for native and introduced fish species and to describe the beneficial use of a possible instream flow water right. The U.S. Geological Survey (USGS) Fort Collins Science Center performed an intensive field study of two sections of Cherry Creek in September 2008 to provide base data for hydrodynamic simulation of the flow conditions in the stream. The USGS Arizona Cooperative Fish and Wildlife Research Unit, at the University of Arizona School of Natural Resources, conducted a survey of the habitat requirements of the resident fish species in Cherry Creek and provided the habitat suitability criteria used in this study. The habitat suitability criteria were combined with hydrodynamic simulation results to quantify fish habitat for the full range of daily flow experienced in the creek and to produce maps of habitat occurrence for those flows. The flow record at the Cherry Creek stream gage was used to generate habitat response values over time. The long-term habitat response was incorporated into an Excel (Registered) spreadsheet to allow evaluation of habitat occurrence with and without an instream water right under different hypothetical water withdrawal scenarios. The spreadsheet displays information about the time sequence of habitat events, the duration of critical events, and habitat retention.

Using a Content Management System for Integrated Water Quantity, Quality and Instream Flows Modeling

NASA Astrophysics Data System (ADS)

Burgholzer, R.; Brogan, C. O.; Scott, D.; Keys, T.

2017-12-01

With increased population and water demand, in-stream flows can become depleted by consumptive uses and dilution of permitted discharges may be compromised. Reduced flows downstream of water withdrawals may increase the violation rate of bacterial concentrations from direct deposition by livestock and wildlife. Water storage reservoirs are constructed and operated to insure more stable supplies for consumptive demands and dilution flows, however their use comes at the cost of increased evaporative losses, potential for thermal pollution, interrupted fish migration, and reduced flooding events that are critical to maintain habitat and water quality. Due to this complex interrelationship between water quantity, quality and instream habitat comprehensive multi-disciplinary models must be developed to insure long-term sustainability of water resources and to avoid conflicts between drinking water, food and energy production, and aquatic biota. The Commonwealth of Virginia funded the expansion of the Chesapeake Bay Program Phase 5 model to cover the entire state, and has been using this model to evaluate water supply permit and planning since 2009. This integrated modeling system combines a content management system (Drupal and PHP) for model input data and leverages the modularity of HSPF with the custom segmentation and parameterization routines programmed by modelers working with the Chesapeake Bay Program. The model has been applied to over 30 Virginia Water Permits, instream flows and aquatic habitat models and a Virginias 30 year water supply demand projections. Future versions will leverage the Bay Model auto-calibration routines for adding small-scale water supply and TMDL models, utilize climate change scenarios, and integrate Virginia's reservoir management modules into the Chesapeake Bay watershed model, feeding projected demand and operational changes back up to EPA models to improve the realism of future Bay-wide simulations.

Development of stream-subsurface flow module in sub-daily simulation of Escherichia coli using SWAT

NASA Astrophysics Data System (ADS)

Kim, Minjeong; Boithias, Laurie; Cho, Kyung Hwa; Silvera, Norbert; Thammahacksa, Chanthamousone; Latsachack, Keooudone; Rochelle-Newall, Emma; Sengtaheuanghoung, Oloth; Pierret, Alain; Pachepsky, Yakov A.; Ribolzi, Olivier

2017-04-01

Water contaminated with pathogenic bacteria poses a large threat to public health, especially in the rural areas in the tropics where sanitation and drinking water facilities are often lacking. Several studies have used the Soil and Water Assessment Tool (SWAT) to predict the export of in-stream bacteria at a watershed-scale. However, SWAT is limited to in-stream processes, such as die-off, resuspension and, deposition; and it is usually implemented on a daily time step using the SCS Curve Number method, making it difficult to explore the dynamic fate and transport of bacteria during short but intense events such as flash floods in tropical humid montane headwaters. To address these issues, this study implemented SWAT on an hourly time step using the Green-Ampt infiltration method, and tested the effects of subsurface flow (LATQ+GWQ in SWAT) on bacterial dynamics. We applied the modified SWAT model to the 60-ha Houay Pano catchment in Northern Laos, using sub-daily rainfall and discharge measurements, electric conductivity-derived fractions of overland and subsurface flows, suspended sediments concentrations, and the number of fecal indicator organism Escherichia coli monitored at the catchment outlet from 2011 to 2013. We also took into account land use change by delineating the watershed with the 3-year composite land use map. The results show that low subsurface flow of less than 1 mm recovered the underestimation of E. coli numbers during the dry season, while high subsurface flow caused an overestimation during the wet season. We also found that it is more reasonable to apply the stream-subsurface flow interaction to simulate low in-stream bacteria counts. Using fecal bacteria to identify and understand the possible interactions between overland and subsurface flows may well also provide some insight into the fate of other bacteria, such as those involved in biogeochemical fluxes both in-stream and in the adjacent soils and hyporheic zones.

In-stream hydrokinetic power: Review and appraisal

DOE PAGES

Van Zwieten, J.; McAnally, William; Ahmad, Jameel; ...

2015-09-01

The objective of this paper is to provide a review of in-stream hydrokinetic power, which is defined as electric power generated by devices capturing the energy of naturally flowing water-stream, tidal, or open ocean flows-without impounding the water. North America has significant in-stream energy resources, and hydrokinetic electric power technologies to harness those resources have the potential to make a significant contribution to U.S. electricity needs by adding as much as 120 TWh/year from rivers alone to the present hydroelectric power generation capacity. Additionally, tidal and ocean current resources in the U.S. respectively contain 438 TWh/year and 163 TWh/year ofmore » extractable power. Among their attractive features, in-stream hydrokinetic operations do not contribute to greenhouse gas emissions or other air pollution and have less visual impact than wind turbines. Since these systems do no utilize dams the way traditional hydropower systems typically do, their impact on the environment will differ, and a small but growing number of studies support conclusions regarding those impacts. Furthermore, potential environmental impacts include altered water quality, altered sediment deposition, altered habitats, direct impact on biota, and navigability of waterways.« less

Supplement Analysis for the Watershed Management Program EIS (DOE/EIS-0265/SA-106) - Water Entity (Trout Unlimited Montana Water Project 2003)

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

Yarde, Richard

2003-06-13

BPA proposes to fund several water rights acquisition projects proposed by Trout Unlimited Montana Water Project (TU). The funding will be administered by the National Fish and Wildlife Foundation, the entity administering the Columbia Basin Water Transactions Program, initiated under RPA 151 of the National Marine Fisheries Service’s 2000 Biological Opinion on the Operation of the Federal Columbia River Power System. The water rights acquired by TU will be left instream to increase flow and improve water quality. Increasing instream flow of water-limited streams benefits fish listed under the Endangered Species Act. The three projects proposed by TU include: amore » Diversion Reduction Agreement, where the landowner agrees to leave up to 4 cubic feet per second (cfs) of water in Rock Creek for the 2003 irrigation season; another Diversion Reduction Agreement for the latter part of the 2003 irrigation season, under which the landowner would agree to cease diverting 1.65 cfs on Rock Creek and between 3 to 6 cfs from the North Fork Blackfoot River; the final proposal is one piece of a larger project in conjunction with other local, federal and state entities, to install a pipeline and sprinkler system to replace a ditch and flood irrigation system, which will result in the conversion of 15.11 cfs of water rights to instream flow. TU's contribution to the proposal (and BPA’s funding) is limited to working with the landowner to convert the water rights to instream flow; all other components of the project, including the irrigation efficiency work, is being done in conjunction with other federal agencies with independent NEPA and other environmental review and consultation obligations.« less

40 CFR 131.12 - Antidegradation policy.

Code of Federal Regulations, 2011 CFR

2011-07-01

... minimum, be consistent with the following: (1) Existing instream water uses and the level of water quality... waters exceed levels necessary to support propagation of fish, shellfish, and wildlife and recreation in... continuing planning process, that allowing lower water quality is necessary to accommodate important economic...

Mixing zone and drinking water intake dilution factor and wastewater generation distributions to enable probabilistic assessment of down-the-drain consumer product chemicals in the U.S.

PubMed

Kapo, Katherine E; McDonough, Kathleen; Federle, Thomas; Dyer, Scott; Vamshi, Raghu

2015-06-15

Environmental exposure and associated ecological risk related to down-the-drain chemicals discharged by municipal wastewater treatment plants (WWTPs) are strongly influenced by in-stream dilution of receiving waters which varies by geography, flow conditions and upstream wastewater inputs. The iSTREEM® model (American Cleaning Institute, Washington D.C.) was utilized to determine probabilistic distributions for no decay and decay-based dilution factors in mean annual and low (7Q10) flow conditions. The dilution factors derived in this study are "combined" dilution factors which account for both hydrologic dilution and cumulative upstream effluent contributions that will differ depending on the rate of in-stream decay due to biodegradation, volatilization, sorption, etc. for the chemical being evaluated. The median dilution factors estimated in this study (based on various in-stream decay rates from zero decay to a 1h half-life) for WWTP mixing zones dominated by domestic wastewater flow ranged from 132 to 609 at mean flow and 5 to 25 at low flow, while median dilution factors at drinking water intakes (mean flow) ranged from 146 to 2×10(7) depending on the in-stream decay rate. WWTPs within the iSTREEM® model were used to generate a distribution of per capita wastewater generated in the U.S. The dilution factor and per capita wastewater generation distributions developed by this work can be used to conduct probabilistic exposure assessments for down-the-drain chemicals in influent wastewater, wastewater treatment plant mixing zones and at drinking water intakes in the conterminous U.S. In addition, evaluation of types and abundance of U.S. wastewater treatment processes provided insight into treatment trends and the flow volume treated by each type of process. Moreover, removal efficiencies of chemicals can differ by treatment type. Hence, the availability of distributions for per capita wastewater production, treatment type, and dilution factors at a national level provides a series of practical and powerful tools for building probabilistic exposure models. Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 131.12 - Antidegradation policy.

Code of Federal Regulations, 2010 CFR

2010-07-01

... QUALITY STANDARDS Establishment of Water Quality Standards § 131.12 Antidegradation policy. (a) The State... minimum, be consistent with the following: (1) Existing instream water uses and the level of water quality... and on the water, that quality shall be maintained and protected unless the State finds, after full...

Advancing towards functional environmental flows for temperate floodplain rivers.

PubMed

Hayes, Daniel S; Brändle, Julia M; Seliger, Carina; Zeiringer, Bernhard; Ferreira, Teresa; Schmutz, Stefan

2018-08-15

Abstraction, diversion, and storage of flow alter rivers worldwide. In this context, minimum flow regulations are applied to mitigate adverse impacts and to protect affected river reaches from environmental deterioration. Mostly, however, only selected instream criteria are considered, neglecting the floodplain as an indispensable part of the fluvial ecosystem. Based on essential functions and processes of unimpaired temperate floodplain rivers, we identify fundamental principles to which we must adhere to determine truly ecologically-relevant environmental flows. Literature reveals that the natural flow regime and its seasonal components are primary drivers for functions and processes of abiotic and biotic elements such as morphology, water quality, floodplain, groundwater, riparian vegetation, fish, macroinvertebrates, and amphibians, thus preserving the integrity of floodplain river ecosystems. Based on the relationship between key flow regime elements and associated environmental components within as well as adjacent to the river, we formulate a process-oriented functional floodplain flow (ff-flow) approach which offers a holistic conceptual framework for environmental flow assessment in temperate floodplain river systems. The ff-flow approach underlines the importance of emulating the natural flow regime with its seasonal variability, flow magnitude, frequency, event duration, and rise and fall of the hydrograph. We conclude that the ecological principles presented in the ff-flow approach ensure the protection of floodplain rivers impacted by flow regulation by establishing ecologically relevant environmental flows and guiding flow restoration measures. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Effects of land use and sample location on nitrate-stream flow hysteresis descriptors during storm events

USGS Publications Warehouse

Feinson, Lawrence S.; Gibs, Jacob; Imbrigiotta, Thomas E.; Garrett, Jessica D.

2016-01-01

The U.S. Geological Survey's New Jersey and Iowa Water Science Centers deployed ultraviolet-visible spectrophotometric sensors at water-quality monitoring sites on the Passaic and Pompton Rivers at Two Bridges, New Jersey, on Toms River at Toms River, New Jersey, and on the North Raccoon River near Jefferson, Iowa to continuously measure in-stream nitrate plus nitrite as nitrogen (NO3 + NO2) concentrations in conjunction with continuous stream flow measurements. Statistical analysis of NO3 + NO2 vs. stream discharge during storm events found statistically significant links between land use types and sampling site with the normalized area and rotational direction of NO3 + NO2-stream discharge (N-Q) hysteresis patterns. Statistically significant relations were also found between the normalized area of a hysteresis pattern and several flow parameters as well as the normalized area adjusted for rotational direction and minimum NO3 + NO2 concentrations. The mean normalized hysteresis area for forested land use was smaller than that of urban and agricultural land uses. The hysteresis rotational direction of the agricultural land use was opposite of that of the urban and undeveloped land uses. An r2 of 0.81 for the relation between the minimum normalized NO3 + NO2 concentration during a storm vs. the normalized NO3 + NO2 concentration at peak flow suggested that dilution was the dominant process controlling NO3 + NO2 concentrations over the course of most storm events.

Relation of physical and chemical characteristics of streams to fish communities in the Red River of the North basin, Minnesota and North Dakota, 1993-95

USGS Publications Warehouse

Goldstein, R.M.; Stauffer, J.C.; Larson, P.R.; Lorenz, D.L.

1996-01-01

Within the instream habitat data set, measures of habitat volume (channel width and depth) and habitat diversity were most significant in explaining the variability of the fish communities. The amount of nonagricultural land and riparian zone integrity from the terrestrial habitat data set were also useful in explaining fish community composition. Variability of mean monthly discharge and the frequency of high and low discharge events during the three years prior to fish sampling were the most influential of the hydrologic variables.The first two axes of the canonical correspondence analysis accounted for 43.3 percent of the variation in the fish community and 52.5 percent of the variation in the environmental-species relation. Water-quality indicators such as the percent of fine material in suspended sediment, minimum dissolved oxygen concentrations, minimum concentrations of dissolved organic carbon, and the range of concentrations of major ions and nutrients were the variables that were most important in the canonical correspondence analysis of water-quality data with fish. No single environmental variable or data set appeared to be more important than another in explaining variation in the fish community. The environmental factors affecting the fish communities of the Red River of the North are interrelated. For the most part, instream environmental conditions (instream habitat, hydrology, and water chemistry) appear to be more important in explaining variability in fish community composition than factors related to the agricultural nature of the basin.

Using high-frequency nitrogen and carbon measurements to decouple temporal dynamics of catchment and in-stream transport and reaction processes in a headwater stream

NASA Astrophysics Data System (ADS)

Blaen, P.; Riml, J.; Khamis, K.; Krause, S.

2017-12-01

Within river catchments across the world, headwater streams represent important sites of nutrient transformation and uptake due to their high rates of microbial community processing and relative abundance in the landscape. However, separating the combined influence of in-stream transport and reaction processes from the overall catchment response can be difficult due to spatio-temporal variability in nutrient and organic matter inputs, flow regimes, and reaction rates. Recent developments in optical sensor technologies enable high-frequency, in situ nutrient measurements, and thus provide opportunities for greater insights into in-stream processes. Here, we use in-stream observations of hourly nitrate (NO3-N), dissolved organic carbon (DOC) and dissolved oxygen (DO) measurements from paired in situ sensors that bound a 1 km headwater stream reach in a mixed-use catchment in central England. We employ a spectral approach to decompose (1) variances in solute loading from the surrounding landscape, and (2) variances in reach-scale in-stream nutrient transport and reaction processes. In addition, we estimate continuous rates of reach-scale NO3-N and DOC assimilation/dissimilation, ecosystem respiration and primary production. Comparison of these results over a range of hydrological conditions (baseflow, variable storm events) and timescales (event-based, diel, seasonal) facilitates new insights into the physical and biogeochemical processes that drive in-stream nutrient dynamics in headwater streams.

Quantifying in-stream nitrate reaction rates using continuously-collected water quality data

Treesearch

Matthew Miller; Anthony Tesoriero; Paul Capel

2016-01-01

High frequency in situ nitrate data from three streams of varying hydrologic condition, land use, and watershed size were used to quantify the mass loading of nitrate to streams from two sources – groundwater discharge and event flow – at a daily time step for one year. These estimated loadings were used to quantify temporally-variable in-stream nitrate processing ...

Optimal flow for brown trout: Habitat - prey optimization.

PubMed

Fornaroli, Riccardo; Cabrini, Riccardo; Sartori, Laura; Marazzi, Francesca; Canobbio, Sergio; Mezzanotte, Valeria

2016-10-01

The correct definition of ecosystem needs is essential in order to guide policy and management strategies to optimize the increasing use of freshwater by human activities. Commonly, the assessment of the optimal or minimum flow rates needed to preserve ecosystem functionality has been done by habitat-based models that define a relationship between in-stream flow and habitat availability for various species of fish. We propose a new approach for the identification of optimal flows using the limiting factor approach and the evaluation of basic ecological relationships, considering the appropriate spatial scale for different organisms. We developed density-environment relationships for three different life stages of brown trout that show the limiting effects of hydromorphological variables at habitat scale. In our analyses, we found that the factors limiting the densities of trout were water velocity, substrate characteristics and refugia availability. For all the life stages, the selected models considered simultaneously two variables and implied that higher velocities provided a less suitable habitat, regardless of other physical characteristics and with different patterns. We used these relationships within habitat based models in order to select a range of flows that preserve most of the physical habitat for all the life stages. We also estimated the effect of varying discharge flows on macroinvertebrate biomass and used the obtained results to identify an optimal flow maximizing habitat and prey availability. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessing the Effects of Water Right Purchases on Stream Temperatures and Fish Habitat

NASA Astrophysics Data System (ADS)

Elmore, L.; Null, S. E.

2012-12-01

Warm stream temperature and low flow conditions are limiting factors for native trout species in Nevada's Walker River. Water rights purchases are being considered to increase instream flow and improve habitat conditions. However, the effect of water rights purchases on stream temperatures and fish habitat have yet to be assessed. Manipulating flow conditions affect stream temperatures by altering water depth, velocity, and thermal mass. This study uses the River Modeling System (RMSv4), an hourly, physically-based hydrodynamic and water quality model, to estimate flows and stream temperatures in the Walker River. The model is developed for two wet years (2010-2011). Study results highlight reaches with cold-water habitat that is suitable for native trout species. Previous research on the Walker River has evaluated instream flow changes with water rights purchases. This study incorporates stream temperatures as a proxy for trout habitat, and thus explicitly incorporates water quality and fish habitat into decision-making regarding water rights purchases. Walker River

Understanding the diurnal cycle in fluvial dissolved organic carbon - The interplay of in-stream residence time, day length and organic matter turnover

NASA Astrophysics Data System (ADS)

Worrall, F.; Howden, N. J. K.; Burt, T. P.

2015-04-01

There is increasing interest in characterising the diurnal fluctuation of stream solute concentrations because observed data series derived from spot samples may be highly subjective if such diurnal fluctuations are large. This can therefore lead to large uncertainties, bias or systematic errors in calculation of fluvial solute fluxes, depending upon the particular sampling regime. A simplistic approach would be to assume diurnal fluctuations are constant throughout the water year, but this study proposes diurnal cycles in stream water quality can only be interpreted in the context of stream residence time and changing day length. Three years of hourly dissolved organic carbon (DOC) concentration and flow data from the River Dee catchment (1674 km2) were analysed, and statistical analysis of the entire record shows there is no consistent diurnal cycle in the record. From the 3-year record (1095 days) there were only 96 diurnal cycles could be analysed. Cycles were quantified in terms of their: relative and absolute amplitude; duration; time to maximum concentration; asymmetry; percentile flow and in-stream residence time. The median diurnal cycle showed an amplitude that was 9.2% of the starting concentration; it was not significantly asymmetric; and occurred at the 19th percentile flow. The median DOC removal rate was 0.07 mg C/l/hr with an inter-quartile range of 0.052-0.100 mg C/l/hr. Results were interpreted as controlled by two, separate, zero-order kinetic rate laws, one for the day and one for the night. There was no single diurnal cycle present across the record, rather a number of different cycles controlled by the combination of in-stream residence time and exposure to contrasting light conditions. Over the 3-year period the average in-stream loss of DOC was 32%. The diurnal cycles evident in high resolution DOC data are interpretable, but require contextual information for their influence on in-stream processes to be understood or for them to be utilised.

Preliminary assessment of Eflows on Lucanian Rivers through IHA implementation

NASA Astrophysics Data System (ADS)

Greco, Michele; Martino, Giovanni

2016-04-01

According to the WFD, the ecological flow (Eflow) is assumed to be the hydrological regime consistent with the achievement of the environmental objectives of "good quality status" in natural surface water bodies. As well known, the hydrological regime of natural flow plays a primary and crucial role influencing the physical conditions of habitats, which in turn determines the biotic composition and sustainability of aquatic ecosystems. Furthermore, the simple assumption to supply a minimum instream during dry periods is not enough anymore in order to protect the river environment. The recent hydro-ecological knowledge provides that all flow components must be included as operational targets for water quantitative management from base flows (including low flows) to high and flood regimes in terms of magnitude, frequency, duration, timing and rate of change. Several conceptual and numerical codes have been developed and applied on different case studies in order to define common tools to be implemented for the Eflow assessment. In such a frame, the work deals with the application of the Indicators of Hydrologic Alteration methodology (IHA by TNC) to main Lucanian rivers to assess the ecological flow to be assumed in each monitoring cross section. The analyses have been carried on monthly discharge data derived through a simple rainfall-runoff applied at the basin scale and based on the precipitation measurements obtained by the regional rainfall gauge stations.

Modeling the Dynamic Water Resource Needs of California's Coastal Watersheds

NASA Astrophysics Data System (ADS)

Alford, C.

2009-12-01

Many watersheds face formidable water supply challenges when it comes to managing water availability to meet diverse water supply and ecosystem management objectives. California’s central coast watersheds are no exception, and both the scarcity of water resources during drier water years and mandates to establish minimum instream flows for salmon habitat have prompted interests in reassessing water management strategies for several of these watersheds. Conventional supply-oriented hydrologic models, however, are not adequate to fully investigate and describe the reciprocal implications of surface water demands for human use and the maintenance of instream flows for salmon habitat that vary both temporally and spatially within a watershed. In an effort to address this issue I developed a coastal watershed management model based on the San Gregorio watershed utilizing the Water Evaluation and Planning (WEAP) system, which permits demand-side prioritization at a time step interval and spatial resolution that captures functional supply and demand relationships. Physiographic input data such as soil type, land cover, elevation, habitat, and water demand sites were extrapolated at a sub-basin level in a GIS. Time-series climate data were collected and processed utilizing the Berkeley Water Center Data Cube at daily time steps for the period 1952 through September 2009. Recent synoptic flow measurements taken at seven tributary sites during the 2009 water year, water depth measured by pressure transducers at six sites within the watershed from September 2005 through September 2009, and daily gauge records from temporary gauges installed in 1981 were used to assess the hydrologic patterns of sub-basins and supplement historic USGS gauge flow records. Empirical functions were used to describe evapotranspiration, surface runoff, sub-surface runoff, and deep percolation. Initial model simulations carried out under both dry and wet water year scenarios were able to capture representative hydrological conditions in both the sample watershed case and an initial test case that utilized base data from a watershed with minimal land disturbance. Results from this study provide valuable insight into the effects of water use through a variety of climactic conditions and provide potential strategies for policy makers, regulators, and stakeholders to strengthen adaptive capacity to achieve sustainable water use within coastal watersheds.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for West Fork Blue River, Washington County, Indiana

USGS Publications Warehouse

Peters, James G.; Wilber, W.G.; Crawford, Charles G.; Girardi, F.P.

1979-01-01

A digital computer model calibrated to observe stream conditions was used to evaluate water quality in West Fork Blue River, Washington County, IN. Instream dissolved-oxygen concentration averaged 96.5% of saturation at selected sites on West Fork Blue River during two 24-hour summer surveys. This high dissolved-oxygen concentration reflects small carbonaceous and nitrogenous waste loads; adequate dilution of waste by the stream; and natural reaeration. Nonpoint source waste loads accounted for an average of 53.2% of the total carbonaceous biochemical-oxygen demand and 90.2% of the nitrogenous biochemical-oxygen demand. Waste-load assimilation was studiedfor critical summer and winter low flows. Natural streamflow for these conditions was zero, so no benefit from dilution was provided. The projected stream reaeration capacity was not sufficient to maintain the minimum daily dissolved-oxygen concentration (5 milligrams per liter) in the stream with current waste-discharge restrictions. During winter low flow, ammonia toxicity, rather than dissolved-oxygen concentration, was the limiting water-quality criterion downstream from the Salem wastewater-treatment facility. (USGS)

Seasonal changes in the diurnal in-stream nitrate concentration oscillations

NASA Astrophysics Data System (ADS)

Rusjan, S.; Mikoš, M.

2009-04-01

A variability of seasonal changes in the diurnal in-stream NO3-N concentration oscillations was studied through high-frequency measurements of the stream-water's physical, chemical parameters (in-stream NO3-N concentration, water temperature, dissolved oxygen, pH) and hydrometeorological variables (stream discharge, solar radiation) under hydrologically stable conditions. The study was carried out in 2006, within the 42 km2 forested Padež stream watershed in the southwestern part of Slovenia, which is characterized by distinctive hydrogeological settings (flysch) and climate conditions (transitional area between the Mediterranean and continental climate). Fine temporal resolution of the data measured at 15 minute intervals enabled the identification of the main driving factors responsible for the seasonal variability in the diurnal pattern of the streamwater NO3-N concentrations vs. seasonal and diurnal behavior of meteorological and other water chemistry constituents. Seasonal variability of the shifts in daily maximum (up to 6 hours) and minimum NO3-N concentrations (between 1 and 3 hours) and changes in the amplitude of the daily NO3-N concentration oscillations (in order of 0.1-0.3 mg/l-N) offer supplementary evidence of the in-stream NO3-N processing by photoautotrophs. A wavelet analysis was further used to acquire clear, de-noised NO3-N concentration signals on which models in the form of Fourier series were build, reaching R2 values between 0.73 and 0.94. The models can be used to simulate the in-stream NO3-N oscillating signal in order to obtain more accurate assessment of the NO3-N exports from the forested watershed in different seasonal settings, undisturbed by the changing hydrological conditions.

Seasonal Changes in diurnal in-Stream Nitrate Concentration Oscillations

NASA Astrophysics Data System (ADS)

Rusjan, Simon; Mikoš, Matjaž; Mitja, Brilly; Vidmar, Andrej

2010-05-01

A variability of seasonal changes in the diurnal in-stream NO3-N concentration oscillations was studied through high-frequency measurements of the stream-water's physical, chemical parameters (in-stream NO3-N concentration, water temperature, dissolved oxygen, pH) and hydrometeorological variables (stream discharge, solar radiation) under hydrologically stable conditions. The study was carried out in 2006, within the 42 km2 forested Padež stream watershed in the southwestern part of Slovenia, which is characterized by distinctive hydrogeological settings (flysch) and climate conditions (transitional area between the Mediterranean and continental climate). Fine temporal resolution of the data measured at 15 minute intervals enabled the identification of the main driving factors responsible for the seasonal variability in the diurnal pattern of the streamwater NO3-N concentrations vs. seasonal and diurnal behavior of meteorological and other water chemistry constituents. Seasonal variability of the shifts in daily maximum (up to 6 hours) and minimum NO3-N concentrations (between 1 and 3 hours) and changes in the amplitude of the daily NO3-N concentration oscillations (in order of 0.1-0.3 mg/l-N) offer supplementary evidence of the in-stream NO3-N processing by photoautotrophs. A wavelet analysis was further used to acquire clear, de-noised NO3-N concentration signals on which models in the form of Fourier series were build, reaching R2 values between 0.73 and 0.94. The models can be used to simulate the in-stream NO3-N oscillating signal in order to obtain more accurate assessment of the NO3-N exports from the forested watershed in different seasonal settings, undisturbed by the changing hydrological conditions.

Interaction of fine sediment with alluvial streambeds

USGS Publications Warehouse

Jobson, Harvey E.; Carey, William P.

1989-01-01

More knowledge is needed about the physical processes that control the transport of fine sediment moving over an alluvial bed. The knowledge is needed to design rational sampling and monitoring programs that assess the transport and fate of toxic substances in surface waters because the toxics are often associated with silt- and clay-sized particles. This technical note reviews some of the past research in areas that may contribute to an increased understanding of the processes involved. An alluvial streambed can have a large capacity to store fine sediments that are extracted from the flow when instream concentrations are high and it can gradually release fine sediment to the flow when the instream concentrations are low. Several types of storage mechanisms are available depending on the relative size distribution of the suspended load and bed material, as well as the flow hydraulics. Alluvial flow tends to segregate the deposited material according to size and density. Some of the storage locations are temporary, but some can store the fine sediment for very long periods of time.

Diel cycles in dissolved metal concentrations in streams: Occurrence and possible causes

USGS Publications Warehouse

Nimick, David A.; Gammons, Christopher H.; Cleasby, Thomas E.; Madison, James P.; Skaar, Don; Brick, Christine M.

2003-01-01

Substantial diel (24‐hour) cycles in dissolved (0.1‐μm filtration) metal concentrations were observed during low flow for 18 sampling episodes at 14 sites on 12 neutral and alkaline streams draining historical mining areas in Montana and Idaho. At some sites, concentrations of Cd, Mn, Ni, and Zn increased as much as 119, 306, 167, and 500%, respectively, from afternoon minimum values to maximum values shortly after sunrise. Arsenic concentrations exhibited the inverse temporal pattern with increases of up to 54%. Variations in Cu concentrations were small and inconsistent. Diel metal cycles are widespread and persistent, occur over a wide range of metal concentrations, and likely are caused primarily by instream geochemical processes. Adsorption is the only process that can explain the inverse temporal patterns of As and the divalent metals. Diel metal cycles have important implications for many types of water‐quality studies and for understanding trace‐metal mobility.

Explaining and modeling the concentration and loading of Escherichia coli in a stream-A case study.

PubMed

Wang, Chaozi; Schneider, Rebecca L; Parlange, Jean-Yves; Dahlke, Helen E; Walter, M Todd

2018-09-01

Escherichia coli (E. coli) level in streams is a public health indicator. Therefore, being able to explain why E. coli levels are sometimes high and sometimes low is important. Using citizen science data from Fall Creek in central NY we found that complementarily using principal component analysis (PCA) and partial least squares (PLS) regression provided insights into the drivers of E. coli and a mechanism for predicting E. coli levels, respectively. We found that stormwater, temperature/season and shallow subsurface flow are the three dominant processes driving the fate and transport of E. coli. PLS regression modeling provided very good predictions under stormwater conditions (R 2  = 0.85 for log (E. coli concentration) and R 2  = 0.90 for log (E. coli loading)); predictions under baseflow conditions were less robust. But, in our case, both E. coli concentration and E. coli loading were significantly higher under stormwater condition, so it is probably more important to predict high-flow E. coli hazards than low-flow conditions. Besides previously reported good indicators of in-stream E. coli level, nitrate-/nitrite-nitrogen and soluble reactive phosphorus were also found to be good indicators of in-stream E. coli levels. These findings suggest management practices to reduce E. coli concentrations and loads in-streams and, eventually, reduce the risk of waterborne disease outbreak. Copyright © 2018. Published by Elsevier B.V.

Model based hydropower gate operation for mitigation of CSO impacts by means of river base flow increase.

PubMed

Achleitner, S; De Toffol, S; Engelhard, C; Rauch, W

2005-01-01

In river stretches being subjected to flow regulation, usually for the purpose of energy production (e.g. Hydropower) or flood protection (river barrage), a special measure can be taken against the effect of combined sewer overflows (CSOs). The basic idea is the temporal increase of the river base flow (during storm weather) as an in-stream measure for mitigation of CSO spilling. The focus is the mitigation of the negative effect of acute pollution of substances. The measure developed can be seen as an application of the classic real time control (RTC) concept onto the river system. Upstream gate operation is to be based on real time monitoring and forecasting of precipitation. The main objective is the development of a model based predictive control system for the gate operation, by modelling of the overall wastewater system (incl. the receiving water). The main emphasis is put on the operational strategy and the appropriate short-term forecast of spilling events. The potential of the measure is tested for the application of the operational strategy and its ecological and economic feasibility. The implementation of such an in-stream measure into the hydropower's operational scheme is unique. Advantages are (a) the additional in-stream dilution of acute pollutants entering the receiving water and (b) the resulting minimization of the required CSO storage volume.

Valuing instream flows using the hedonic price method

NASA Astrophysics Data System (ADS)

Netusil, Noelwah R.; Summers, Matthew T.

2009-11-01

The Oregon Water Trust (OWT) uses a market-based approach to protect and enhance instream flows in Oregon. We use the hedonic price method to estimate the effect of numerous variables on the annualized price OWT pays for water rights: the amount of water protected by the transaction, transaction type (state approved or contractual agreement), presence of anadromous and/or resident fish, and if a fish is listed under the Endangered Species Act (ESA). We find evidence of a premium for state-approved transactions and for transactions that protect water in streams with listed species. Adjusting the amount of water protected by each transaction to include only rights that will be delivered with a high degree of certainty produces coefficient estimates that are similar, but more accurate, than using unadjusted water rights amounts.

Nature of flow and turbulence structure around an in-stream vertical plate in a shallow channel and the implications for sediment erosion

NASA Astrophysics Data System (ADS)

Kirkil, Gokhan; Constantinescu, George

2009-06-01

Detailed knowledge of the dynamics of large-scale turbulence structures is needed to understand the geomorphodynamic processes around in-stream obstacles present in rivers. Detached Eddy Simulation is used to study the flow past a high-aspect-ratio rectangular cylinder (plate) mounted on a flat-bed relatively shallow channel at a channel Reynolds number of 2.4 × 105. Similar to other flows past surface-mounted bluff bodies, the large amplification of the turbulence inside the horseshoe vortex system is because the core of the main necklace vortex is subject to large-scale bimodal oscillations. The presence of a sharp edge at the flanks of the obstruction fixes the position of the flow separation at all depths and induces the formation and shedding of very strong wake rollers over the whole channel depth. Compared with the case of a circular cylinder where the intensity of the rollers decays significantly in the near-bed region because the incoming flow velocity is not sufficient to force the wake to transition from subcritical to supercritical regime, in the case of a high-aspect-ratio rectangular cylinder the passage of the rollers was found to induce high bed-shear stresses at large distances (6-8 D) behind the obstruction. Also, the nondimensional values of the pressure root-mean-square fluctuations at the bed were found to be about 1 order of magnitude higher than the ones predicted for circular cylinders. Overall, this shows that the shape of the in-stream obstruction can greatly modify the dynamics of the large-scale coherent structures, the nature of their interactions, and ultimately, their capability to entrain and transport sediment particles and the speed at which the scour process evolves during its initial stages.

Instream Flows Incremental Methodology :Kootenai River, Montana : Final Report 1990-2000.

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

Hoffman, Greg; Skaar, Don; Dalbey, Steve

2002-11-01

Regulated rivers such as the Kootenai River below Libby Dam often exhibit hydrographs and water fluctuation levels that are atypical when compared to non-regulated rivers. These flow regimes are often different conditions than those which native fish species evolved with, and can be important limiting factors in some systems. Fluctuating discharge levels can change the quantity and quality of aquatic habitat for fish. The instream flow incremental methodology (IFIM) is a tool that can help water managers evaluate different discharges in terms of their effects on available habitat for a particular fish species. The U.S. Fish and Wildlife Service developedmore » the IFIM (Bovee 1982) to quantify changes in aquatic habitat with changes in instream flow (Waite and Barnhart 1992; Baldridge and Amos 1981; Gore and Judy 1981; Irvine et al. 1987). IFIM modeling uses hydraulic computer models to relate changes in discharge to changes in the physical parameters such as water depth, current velocity and substrate particle size, within the aquatic environment. Habitat utilization curves are developed to describe the physical habitat most needed, preferred or tolerated for a selected species at various life stages (Bovee and Cochnauer 1977; Raleigh et al. 1984). Through the use of physical habitat simulation computer models, hydraulic and physical variables are simulated for differing flows, and the amount of usable habitat is predicted for the selected species and life stages. The Kootenai River IFIM project was first initiated in 1990, with the collection of habitat utilization and physical hydraulic data through 1996. The physical habitat simulation computer modeling was completed from 1996 through 2000 with the assistance from Thomas Payne and Associates. This report summarizes the results of these efforts.« less

Estimating shallow groundwater availability in small catchments using streamflow recession and instream flow requirements of rivers in South Africa

NASA Astrophysics Data System (ADS)

Ebrahim, Girma Y.; Villholth, Karen G.

2016-10-01

Groundwater is an important resource for multiple uses in South Africa. Hence, setting limits to its sustainable abstraction while assuring basic human needs is required. Due to prevalent data scarcity related to groundwater replenishment, which is the traditional basis for estimating groundwater availability, the present article presents a novel method for determining allocatable groundwater in quaternary (fourth-order) catchments through information on streamflow. Using established methodologies for assessing baseflow, recession flow, and instream ecological flow requirement, the methodology develops a combined stepwise methodology to determine annual available groundwater storage volume using linear reservoir theory, essentially linking low flows proportionally to upstream groundwater storages. The approach was trialled for twenty-one perennial and relatively undisturbed catchments with long-term and reliable streamflow records. Using the Desktop Reserve Model, instream flow requirements necessary to meet the present ecological state of the streams were determined, and baseflows in excess of these flows were converted into a conservative estimates of allocatable groundwater storages on an annual basis. Results show that groundwater development potential exists in fourteen of the catchments, with upper limits to allocatable groundwater volumes (including present uses) ranging from 0.02 to 3.54 × 106 m3 a-1 (0.10-11.83 mm a-1) per catchment. With a secured availability of these volume 75% of the years, variability between years is assumed to be manageable. A significant (R2 = 0.88) correlation between baseflow index and the drainage time scale for the catchments underscores the physical basis of the methodology and also enables the reduction of the procedure by one step, omitting recession flow analysis. The method serves as an important complementary tool for the assessment of the groundwater part of the Reserve and the Groundwater Resource Directed Measures in South Africa and could be adapted and applied elsewhere.

Selecting quantitative water management measures at the river basin scale in a global change context

NASA Astrophysics Data System (ADS)

Girard, Corentin; Rinaudo, Jean-Daniel; Caballero, Yvan; Pulido-Velazquez, Manuel

2013-04-01

One of the main challenges in the implementation of the Water Framework Directive (WFD) in the European Union is the definition of programme of measures to reach the good status of the European water bodies. In areas where water scarcity is an issue, one of these challenges is the selection of water conservation and capacity expansion measures to ensure minimum environmental in-stream flow requirements. At the same time, the WFD calls for the use of economic analysis to identify the most cost-effective combination of measures at the river basin scale to achieve its objective. With this respect, hydro-economic river basin models, by integrating economics, environmental and hydrological aspects at the river basin scale in a consistent framework, represent a promising approach. This article presents a least-cost river basin optimization model (LCRBOM) that selects the combination of quantitative water management measures to meet environmental flows for future scenarios of agricultural and urban demand taken into account the impact of the climate change. The model has been implemented in a case study on a Mediterranean basin in the south of France, the Orb River basin. The water basin has been identified as in need for quantitative water management measures in order to reach the good status of its water bodies. The LCRBOM has been developed using GAMS, applying Mixed Integer Linear Programming. It is run to select the set of measures that minimizes the total annualized cost of the applied measures, while meeting the demands and minimum in-stream flow constraints. For the economic analysis, the programme of measures is composed of water conservation measures on agricultural and urban water demands. It compares them with measures mobilizing new water resources coming from groundwater, inter-basin transfers and improvement in reservoir operating rules. The total annual cost of each measure is calculated for each demand unit considering operation, maintenance and investment costs. The results show that by combining quantitative water management measures, the flow regime can be improved to better mimic the natural flow regime. However, the acceptability of the higher cost of the program of measures is not yet assessed. Other stages such as stakeholder participation and negotiation processes are as well required to design an acceptable programme of measures. For this purpose, this type of model opens the path to investigate the problems of equity issues, and measures and costs allocation among the stakeholders of the basin. Acknowledgments: The study has been partially supported by the Hérault General Council, the Languedoc-Rousillon Regional Council, the Rhône Mediterranean Corsica Water Agency and the BRGM, as well as the European Community 7th Framework Project GENESIS (n. 226536) on groundwater systems, and the Plan Nacional I+D+I 2008-2011 of the Spanish Ministry of Science and Innovation (subprojects CGL2009-13238-C02-01 and CGL2009-13238-C02-02).

Microbial enzyme activity, nutrient uptake and nutrient limitation in forested streams

Treesearch

Brian H. Hill; Frank H. McCormick; Bret C. Harvey; Sherri L. Johnson; Melvin L. Warren; Colleen M. Elonen

2010-01-01

The flow of organic matter and nutrients from catchments into the streams draining them and the biogeochemical transformations of organic matter and nutrients along flow paths are fundamental processes instreams (Hynes,1975; Fisher, Sponseller & Heffernan, 2004). Microbial biofilms are often the primary interface for organic matter and nutrient uptake and...

Computational and Experimental Characterization of the Mach 6 Facility Nozzle Flow for the Enhanced Injection and Mixing Project at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Drozda, Tomasz G.; Cabell, Karen F.; Passe, Bradley J.; Baurle, Robert A.

2017-01-01

Computational fluid dynamics analyses and experimental data are presented for the Mach 6 facility nozzle used in the Arc-Heated Scramjet Test Facility for the Enhanced Injection and Mixing Project (EIMP). This project, conducted at the NASA Langley Research Center, aims to investigate supersonic combustion ramjet (scramjet) fuel injection and mixing physics relevant to flight Mach numbers greater than 8. The EIMP experiments use a two-dimensional Mach 6 facility nozzle to provide the high-speed air simulating the combustor entrance flow of a scramjet engine. Of interest are the physical extent and the thermodynamic properties of the core flow at the nozzle exit plane. The detailed characterization of this flow is obtained from three-dimensional, viscous, Reynolds-averaged simulations. Thermodynamic nonequilibrium effects are also investigated. The simulations are compared with the available experimental data, which includes wall static pressures as well as in-stream static pressure, pitot pressure and total temperature obtained via in-stream probes positioned just downstream of the nozzle exit plane.

Upland and in-stream controls on baseflow nutrient dynamics in tile-drained agroecosystem watersheds

NASA Astrophysics Data System (ADS)

Ford, William I.; King, Kevin; Williams, Mark R.

2018-01-01

In landscapes with low residence times (e.g., rivers and reservoirs), baseflow nutrient concentration dynamics during sensitive timeframes can contribute to deleterious environmental conditions downstream. This study assessed upland and in-stream controls on baseflow nutrient concentrations in a low-gradient, tile-drained agroecosystem watershed. We conducted time-series analysis using Empirical mode decomposition of seven decade-long nutrient concentration time-series in the agricultural Upper Big Walnut Creek watershed (Ohio, USA). Four tributaries of varying drainage areas and three main-stem sites were monitored, and nutrient grab samples were collected weekly from 2006 to 2016 and analyzed for dissolved reactive phosphorus (DRP), nitrate-nitrogen (NO3-N), total nitrogen (TN), and total phosphorus (TP). Statistically significant seasonal fluctuations were compared with seasonality of baseflow, watershed characteristics (e.g., tile-drain density), and in-stream water quality parameters (pH, DO, temperature). Findings point to statistically significant seasonality of all parameters with peak P concentrations in summer and peak N in late winter-early spring. Results suggest that upland processes exert strong control on DRP concentrations in the winter and spring months, while coupled upland and in-stream conditions control watershed baseflow DRP concentrations during summer and early fall. Conversely, upland flow sources driving streamflow exert strong control on baseflow NO3-N, and in-stream attenuation through transient and permanent pathways impacts the magnitude of removal. Regarding TN and TP, we found that TN was governed by NO3-N, while TP was governed by DRP in summer and fluvial erosion of P-rich benthic sediments during higher baseflow conditions. Findings of the study highlight the importance of coupled in-stream and upland management for mitigating eutrophic conditions during environmentally sensitive timeframes.

Evaluation of the instream flow incremental methodology by U.S. Fish and Wildlife Service field users

USGS Publications Warehouse

Armour, Carl L.; Taylor, Jonathan G.

1991-01-01

This paper summarizes results of a survey conducted in 1988 of 57 U.S. Fish and Wildlife Service field offices. The purpose was to document opinions of biologists experienced in applying the Instream Flow Incremental Methodology (IFIM). Responses were received from 35 offices where 616 IFIM applications were reported. The existence of six monitoring studies designed to evaluate the adequacy of flows provided at sites was confirmed. The two principal categories reported as stumbling blocks to the successful application of IFIM were beliefs that the methodology is technically too simplistic or that it is too complex to apply. Recommendations receiving the highest scores for future initiatives to enhance IFIM use were (1) training and workshops for field biologists; and (2) improving suitability index (SI) curves and computer models, and evaluating the relationship of weighted useable area (WUA) to fish responses. The authors concur that emphasis for research should be on addressing technical concerns about SI curves and WUA.

Trends in Streamflow Characteristics in Hawaii, 1913-2002

USGS Publications Warehouse

Oki, Delwyn S.

2004-01-01

The surface-water resources of Hawaii have significant cultural, aesthetic, ecologic, and economic importance. In Hawaii, surface-water resources are developed for both offstream uses (for example, drinking water, agriculture, and industrial uses) and instream uses (for example, maintenance of habitat and ecosystems, recreational activities, aesthetic values, maintenance of water quality, conveyance of irrigation and domestic water supplies, and protection of traditional and customary Hawaiian rights). Possible long-term trends in streamflow characteristics have important implications for water users, water suppliers, resource managers, and citizens in the State. Proper management of Hawaii's streams requires an understanding of long-term trends in streamflow characteristics and their potential implications. Effects of long-term downward trends in low flows in streams include potential loss of habitat for native stream fauna and reduced water availability for offstream and instream water uses. Effects of long-term upward trends in high flows in streams include construction of bridges and water-conveyance structures that are potentially unsafe if they are not designed with proper consideration of trends in high flows.

Management of adverse effects of a public water supply well field on the aquatic habitat of a stratified drift stream in eastern Connecticut.

PubMed

Nadim, Farhad; Bagtzoglou, Amvrossios C; Baun, Sandrine A; Warner, Glenn S; Ogden, Fred; Jacobson, Richard A; Parasiewicz, Piotr

2007-01-01

A study was conducted to determine the effect of water withdrawals from the University of Connecticut's (Storrs) water supply wells on the fisheries habitat of the Fenton River adjacent to the well field. The study was designed to investigate the relationships between in-stream flow and selected fish habitat in the section of the Fenton River situated in the main zone of influence of the pumping field. With the aid of historical data, new data collection, and mathematical simulation modeling, the relation between the magnitude and timing of groundwater withdrawals on the stage and flow of water in the stream was derived. Fish sampling and habitat modeling were used to assess the effects of human influence on certain reaches of the Fenton River. Among the various water management scenarios studied, several are presented that would optimize water withdrawals, while minimizing adverse effects on the stream flow and in-stream habitat.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for East Fork White River, Bartholomew County, Indiana

USGS Publications Warehouse

Wilber, William G.; Peters, James G.; Crawford, Charles G.

1979-01-01

A digital model calibrated to conditions in East Fork White River, Bartholomew County, IN, was used to develop alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. The model indicates that benthic-oxygen demand and the headwater concentrations of carbonaceous biochemical-oxygen demand, nitrogenous biochemical-oxygen demand, and dissolved oxygen are the most significant factors affecting the dissolved-oxygen concentration of East Fork White River downstream from the Columbus wastewater-treatment facility. The effect of effluent from the facility on the water quality of East Fork White River was minimal. The model also indicates that, with a benthic-oxygen demand of approximately 0.65 gram per square meter per day, the stream has no additional waste-load assimilative capacity during summer low flows. Regardless of the quality of the Columbus wastewater effluent, the minimum 24-hour average dissolved-oxygen concentration of at least 5 milligrams per liter, the State 's water-quality standard for streams, would not be met. Ammonia toxicity is not a limiting water-quality criterion during summer and winter low flows. During winter low flows, the current carbonaceous biochemical-oxygen demand limits for the Columbus wastewater-treatment facility will not result in violations of the in-stream dissolved-oxygen standard. (USGS)

Multi-decadal Decline of Southeast United States Streamflow

NASA Astrophysics Data System (ADS)

Tootle, G. A.; Lakshmi, V.; Therrell, M.; Huffaker, R.; Elliott, E. A.

2017-12-01

Unprecedented population growth combined with environmental and energy demands have led to water conflict in the Southeastern United States. The states of Florida, Georgia and Alabama have recently engaged in litigation on minimum in-stream flows to maintain ecosystems, fisheries and energy demands while satisfying a growing thirst in metropolitan Atlanta. A study of Southeastern United States (Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee) streamflow identified a declining pattern of flow over the past 25 years with increased dry periods being observed in the last decade. When evaluating calendar year streamflow for (56) unimpaired streamflow stations, a robust period of streamflow in the 1970's was followed by a consistent decline in streamflow from 1990 to present. In evaluating 20-year, 10-year and 5-year time periods of annual streamflow volume, the past decade reveals historic lows for each of these periods. When evaluating the influence of high frequency (e.g., El Nino-Southern Oscillation - ENSO) and low frequency (e.g., Atlantic Multi-decadal Oscillation - AMO) climatic phenomenon, the shift of the AMO from a cold phase to a warm phase in the 1990's combined with multiple La Nina events may be associated with the streamflow decline.

Operational Constraints on Hydropeaking and its Effects on the Hydrologic and Thermal Regime of a River in Central Chile

NASA Astrophysics Data System (ADS)

Olivares, M. A.; Guzman, C.; Rossel, V.; De La Fuente, A.

2013-12-01

Hydropower accounts for about 44% of installed capacity in Chile's Central Interconnected System, which serves most of the Chilean population. Hydropower reservoir projects can affect ecosystems by changing the hydrologic regime and water quality. Given its volumen regulation capacity, low operation costs and fast response to demand fluctuations, reservoir hydropower plants commonly operate on a load-following or hydropeaking scheme. This short-term operational pattern produces alterations in the hydrologic regime downstream the reservoir. In the case of thermally stratified reservoirs, peaking operations can affect the thermal structure of the reservoir, as well as the thermal regime downstream. In this study, we assessed the subdaily hydrologic and thermal alteration donwstream of Rapel reservoir in Central Chile for alternative operational scenarios, including a base case and several scenarios involving minimum instream flow (Qmin) and maximum hourly ramping rates (ΔQmax). Scenarios were simulated for the stratification season of summer 2009-2012 in a grid-wide short-term economic dispatch model which prescribes hourly power production by every power plant on a weekly horizon. Power time series are then translated into time series of turbined flows at each hydropower plants. Indicators of subdaily hydrologic alteration (SDHA) were computed for every scenario. Additionally, turbined flows were used as input data for a three-dimensional hydrodynamic model (CWR-ELCOM) of the reservoir which simulated the vertical temperature profile in the reservoir and the outflow temperature. For the time series of outflow temperatures we computed several indicators of subdaily thermal alteration (SDTA). Operational constraints reduce the values of both SDHA and SDTA indicators with respect to the base case. When constraints are applied separately, the indicators of SDHA decrease as each type of constraint (Qmin or ΔQmax) becomes more stringent. However, ramping rate constraints proved more effective than minimun instream flows. Combined constraints produced even better results. Results for the indicators of SDTA follow a similar trend than that of SDHA. More restrictive operations result in lower values for the indicators. However, the impact of the different constraint scenarios is smaller, as results look alike for all scenarios. Moreover, due to the mixing conditions associated to the operational schemes, mean temperatures increased with respect to the unconstrained case.

Characterizing coarse bedload transport during floods with RFID and accelerometer tracers, in-stream RFID antennas and HEC-RAS modeling

NASA Astrophysics Data System (ADS)

Olinde, L.; Johnson, J. P.

2013-12-01

By monitoring the transport timing and distances of tracer grains in a steep mountains stream, we collected data that can constrain numerical bedload transport models considered for these systems. We captured bedload activity during a weeks-spanning snowmelt period in Reynolds Creek, Idaho by deploying Radio Frequency Identification (RFID) and accelerometer embedded tracers with in-stream stationary RFID antennas. During transport events, RFID dataloggers recorded the times when tracers passed over stationary antennas. The accelerometer tracers also logged x, y, z-axis accelerations every 10 minutes to identify times of motion and rest. After snowmelt flows receded, we found tracers with mobile antennas and surveyed their positions. We know the timing and tracer locations when accelerometer tracers were initially entrained, passed stationary antennas, and were finally deposited at the surveyed locations. The fraction of moving accelerometers over time correlates well with discharge. Comparisons of the transported tracer fraction between rising and falling limbs over multiple flood peaks suggest that some degree of clockwise hysteresis persisted during the snowmelt period. Additionally, we apply accelerometer transport durations and displacement distances to calculate virtual velocities over full tracer path lengths and over lengths between initial locations to stationary antennas as well as between stationary antennas to final positions. The accelerometer-based virtual velocities are significantly faster than those estimated from traditional tracer methods that estimate bedload transport durations by assuming threshold flow conditions. We also subsample the motion data to calculate how virtual velocities change over the measurement intervals. Regressions of these relations are in turn used to extrapolate virtual velocities at smaller sampling timescales. Minimum hop lengths are also evaluated for each accelerometer tracer. Finally, flow conditions during the snowmelt hydrograph are modeled over the 11 kilometers of surveyed stream by utilizing 1m airborne LiDAR and HEC-GeoRAS. Cross-sectional HEC-RAS results are used to estimate the spatial distribution of longitudinal shear velocities over the observed discharges. At final accelerometer tracer positions, we analyze the HEC-RAS generated flow conditions for each disentrainment discharge magnitude. The techniques developed here have the potential to link individual grain characteristics during floods to a range of time and length scales.

75 FR 30388 - Natural Currents Energy Services, LLC; Notice of Preliminary Permit Application Accepted for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-01

... and marinas within the site. Natural Currents Red Hawk \\TM\\ Tidal In-Stream Energy Conversion (TISEC) modules would generate electricity in the free flow of the tides. The initial installations will consist...

Response of a Brook Trout Population and Instream Habitat to a Catastrophic Flood and Debris Flow

Treesearch

Criag N. Roghair; C. Andrew Dolloff; Martin K. Underwood

2002-01-01

In June 1995, a massive flood and debris flow impacted fish and habitat along the lower 1.9 km of the Staunton River, a headwater stream located in Shenandoah National Park, Virginia. In the area affected by debris flow, the stream bed was scoured and new substrate materials were deposited, trees were removed from a 30-m-wide band in the riparian area, and all fish...

The importance of base flow in sustaining surface water flow in the Upper Colorado River Basin

USGS Publications Warehouse

Miller, Matthew P.; Buto, Susan G.; Susong, David D.; Rumsey, Christine

2016-01-01

The Colorado River has been identified as the most overallocated river in the world. Considering predicted future imbalances between water supply and demand and the growing recognition that base flow (a proxy for groundwater discharge to streams) is critical for sustaining flow in streams and rivers, there is a need to develop methods to better quantify present-day base flow across large regions. We adapted and applied the spatially referenced regression on watershed attributes (SPARROW) water quality model to assess the spatial distribution of base flow, the fraction of streamflow supported by base flow, and estimates of and potential processes contributing to the amount of base flow that is lost during in-stream transport in the Upper Colorado River Basin (UCRB). On average, 56% of the streamflow in the UCRB originated as base flow, and precipitation was identified as the dominant driver of spatial variability in base flow at the scale of the UCRB, with the majority of base flow discharge to streams occurring in upper elevation watersheds. The model estimates an average of 1.8 × 1010 m3/yr of base flow in the UCRB; greater than 80% of which is lost during in-stream transport to the Lower Colorado River Basin via processes including evapotranspiration and water diversion for irrigation. Our results indicate that surface waters in the Colorado River Basin are dependent on base flow, and that management approaches that consider groundwater and surface water as a joint resource will be needed to effectively manage current and future water resources in the Basin.

The importance of base flow in sustaining surface water flow in the Upper Colorado River Basin

NASA Astrophysics Data System (ADS)

Miller, Matthew P.; Buto, Susan G.; Susong, David D.; Rumsey, Christine A.

2016-05-01

The Colorado River has been identified as the most overallocated river in the world. Considering predicted future imbalances between water supply and demand and the growing recognition that base flow (a proxy for groundwater discharge to streams) is critical for sustaining flow in streams and rivers, there is a need to develop methods to better quantify present-day base flow across large regions. We adapted and applied the spatially referenced regression on watershed attributes (SPARROW) water quality model to assess the spatial distribution of base flow, the fraction of streamflow supported by base flow, and estimates of and potential processes contributing to the amount of base flow that is lost during in-stream transport in the Upper Colorado River Basin (UCRB). On average, 56% of the streamflow in the UCRB originated as base flow, and precipitation was identified as the dominant driver of spatial variability in base flow at the scale of the UCRB, with the majority of base flow discharge to streams occurring in upper elevation watersheds. The model estimates an average of 1.8 × 1010 m3/yr of base flow in the UCRB; greater than 80% of which is lost during in-stream transport to the Lower Colorado River Basin via processes including evapotranspiration and water diversion for irrigation. Our results indicate that surface waters in the Colorado River Basin are dependent on base flow, and that management approaches that consider groundwater and surface water as a joint resource will be needed to effectively manage current and future water resources in the Basin.

Estimating Discharge and Nonpoint Source Nitrate Loading to Streams From Three End-Member Pathways Using High-Frequency Water Quality Data

NASA Astrophysics Data System (ADS)

Miller, Matthew P.; Tesoriero, Anthony J.; Hood, Krista; Terziotti, Silvia; Wolock, David M.

2017-12-01

The myriad hydrologic and biogeochemical processes taking place in watersheds occurring across space and time are integrated and reflected in the quantity and quality of water in streams and rivers. Collection of high-frequency water quality data with sensors in surface waters provides new opportunities to disentangle these processes and quantify sources and transport of water and solutes in the coupled groundwater-surface water system. A new approach for separating the streamflow hydrograph into three components was developed and coupled with high-frequency nitrate data to estimate time-variable nitrate loads from chemically dilute quick flow, chemically concentrated quick flow, and slowflow groundwater end-member pathways for periods of up to 2 years in a groundwater-dominated and a quick-flow-dominated stream in central Wisconsin, using only streamflow and in-stream water quality data. The dilute and concentrated quick flow end-members were distinguished using high-frequency specific conductance data. Results indicate that dilute quick flow contributed less than 5% of the nitrate load at both sites, whereas 89 ± 8% of the nitrate load at the groundwater-dominated stream was from slowflow groundwater, and 84 ± 25% of the nitrate load at the quick-flow-dominated stream was from concentrated quick flow. Concentrated quick flow nitrate concentrations varied seasonally at both sites, with peak concentrations in the winter that were 2-3 times greater than minimum concentrations during the growing season. Application of this approach provides an opportunity to assess stream vulnerability to nonpoint source nitrate loading and expected stream responses to current or changing conditions and practices in watersheds.

Balancing power production and instream flow regime for small scale hydropower

NASA Astrophysics Data System (ADS)

Perona, P.; Gorla, L.; Characklis, G. W.

2013-12-01

Flow diversion from river and torrent main stems is a common practice to feed water uses such run-of-river and mini-hydropower, irrigation, etc. Considering the worldwide increasing water demand, it becomes mandatory to take the importance of riparian ecosystems and related biodiversity into account before starting such practices. In this paper, we use a simple hydro-economic model (Perona et al., 2013, Gorla and Perona, 2013) to show that redistribution policies at diversion nodes allow for a clear bio-economic interpretation of residual flows. This model uses the Principle of Equal Marginal Utility (PEMU) as optimal water allocation rule for generating natural-like flow releases while maximizing the aggregated economic benefits of both the riparian environment and the traditional use (e.g., hydropower). We show that both static and dynamic release polices such Minimal Flow, and Proportional/Non-proportional Repartitions, respectively, can all be represented in terms of PEMU, making explicit the value of the ecosystem health underlying each policy. The related ecological and economical performances are evaluated by means of hydrological/ecological indicators. We recommend taking this method into account as a helpful tool guiding political, economical and ecological decisions when replacing the inadequate concept of Minimum Flow Requirement (MFR) with dynamic ones. References Perona, P., D. Dürrenmatt and G. Characklis (2013) Obtaining natural-like flow releases in diverted river reaches from simple riparian benefit economic models. Journal of Environmental Management, 118: 161-169, http://dx.doi.org/10.1016/j.jenvman.2013.01.010 Gorla, L. and P. Perona (2013) On quantifying ecologically sustainable flow releases in a diverted river reach. Journal of Hydrology, 489: 98- 107, http://dx.doi.org/10.1016/j.jhydrol.2013.02.043

Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition

EPA Science Inventory

Boosted regression tree (BRT) models were developed to quantify the nonlinear relationships between landscape variables and nutrient concentrations in a mesoscale mixed land cover watershed during base-flow conditions. Factors that affect instream biological components, based on ...

EPA ’s ECOLOGICAL MODELS FOR INTEGRATED WATERSHED MANAGEMENT

EPA Science Inventory

Aquatic ecological populations and communities are affected by the nature and quality of the water in which they live. Specific factors that affect instream biota include chemical variables, biotic interactions, energy source, flow regime, and habitat structure. As watershed mana...

The role of interior watershed processes in improving parameter estimation and performance of watershed models.

PubMed

Yen, Haw; Bailey, Ryan T; Arabi, Mazdak; Ahmadi, Mehdi; White, Michael J; Arnold, Jeffrey G

2014-09-01

Watershed models typically are evaluated solely through comparison of in-stream water and nutrient fluxes with measured data using established performance criteria, whereas processes and responses within the interior of the watershed that govern these global fluxes often are neglected. Due to the large number of parameters at the disposal of these models, circumstances may arise in which excellent global results are achieved using inaccurate magnitudes of these "intra-watershed" responses. When used for scenario analysis, a given model hence may inaccurately predict the global, in-stream effect of implementing land-use practices at the interior of the watershed. In this study, data regarding internal watershed behavior are used to constrain parameter estimation to maintain realistic intra-watershed responses while also matching available in-stream monitoring data. The methodology is demonstrated for the Eagle Creek Watershed in central Indiana. Streamflow and nitrate (NO) loading are used as global in-stream comparisons, with two process responses, the annual mass of denitrification and the ratio of NO losses from subsurface and surface flow, used to constrain parameter estimation. Results show that imposing these constraints not only yields realistic internal watershed behavior but also provides good in-stream comparisons. Results further demonstrate that in the absence of incorporating intra-watershed constraints, evaluation of nutrient abatement strategies could be misleading, even though typical performance criteria are satisfied. Incorporating intra-watershed responses yields a watershed model that more accurately represents the observed behavior of the system and hence a tool that can be used with confidence in scenario evaluation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effects of turbulent hyporheic mixing on reach-scale solute transport

NASA Astrophysics Data System (ADS)

Roche, K. R.; Li, A.; Packman, A. I.

2017-12-01

Turbulence rapidly mixes solutes and fine particles into coarse-grained streambeds. Both hyporheic exchange rates and spatial variability of hyporheic mixing are known to be controlled by turbulence, but it is unclear how turbulent mixing influences mass transport at the scale of stream reaches. We used a process-based particle-tracking model to simulate local- and reach-scale solute transport for a coarse-bed stream. Two vertical mixing profiles, one with a smooth transition from in-stream to hyporheic transport conditions and a second with enhanced turbulent transport at the sediment-water interface, were fit to steady-state subsurface concentration profiles observed in laboratory experiments. The mixing profile with enhanced interfacial transport better matched the observed concentration profiles and overall mass retention in the streambed. The best-fit mixing profiles were then used to simulate upscaled solute transport in a stream. Enhanced mixing coupled in-stream and hyporheic solute transport, causing solutes exchanged into the shallow subsurface to have travel times similar to the water column. This extended the exponential region of the in-stream solute breakthrough curve, and delayed the onset of the heavy power-law tailing induced by deeper and slower hyporheic porewater velocities. Slopes of observed power-law tails were greater than those predicted from stochastic transport theory, and also changed in time. In addition, rapid hyporheic transport velocities truncated the hyporheic residence time distribution by causing mass to exit the stream reach via subsurface advection, yielding strong exponential tempering in the in-stream breakthrough curves at the timescale of advective hyporheic transport through the reach. These results show that strong turbulent mixing across the sediment-water interface violates the conventional separation of surface and subsurface flows used in current models for solute transport in rivers. Instead, the full distribution of flow and mixing over the surface-subsurface continuum must be explicitly considered to properly interpret solute transport in coarse-bed streams.

Instream wood recruitment, channel complexity, and their relationship to stream ecology in forested headwater streams under alternative stable states

NASA Astrophysics Data System (ADS)

Livers, B.; Wohl, E.

2015-12-01

Human alteration to forests has had lasting effects on stream channels worldwide. Such land use changes affect how wood enters and is stored in streams as individual pieces and as logjams. Changes in wood recruitment affect the complexity and benefits wood can provide to the stream environment, such as zones of flow separation that store fine sediment and organic matter, increased nutrient processing, and greater habitat potential, which can enhance biota and cascade through stream-riparian ecosystems. Previous research in our study area shows that modern headwater streams flowing through old-growth, unmanaged forests have more wood than streams in young, managed forests, but does not explicitly evaluate how wood affects channel complexity or local ecology. 'Managed' refers to forests previously or currently exposed to human alteration. Alteration has long since ceased in some areas, but reduced wood loads in managed streams persist. Our primary objective was to quantify stream complexity metrics, with instream wood as a mediator, on streams across a gradient of management and disturbance histories in order to examine legacy effects of human alteration to forests. Data collected in the Southern Rocky Mountains include 24 2nd to 3rd order subalpine streams categorized into: old-growth unmanaged; younger, naturally disturbed unmanaged; and younger managed. We assessed instream wood loads and logjams and evaluated how they relate to channel complexity using a number of metrics, such as standard deviation of bed and banks, volume of pools, ratios of stream to valley lengths and stream to valley area, and diversity of substrate, gradient, and morphology. Preliminary results show that channel complexity is directly related to instream wood loads and is greatest in streams in old-growth. Related research in the field area indicates that streams with greater wood loads also have increased nutrient processing and greater abundance and diversity of aquatic insect predators.

Stream habitat analysis using the instream flow incremental methodology

USGS Publications Warehouse

Bovee, Ken D.; Lamb, Berton L.; Bartholow, John M.; Stalnaker, Clair B.; Taylor, Jonathan; Henriksen, Jim

1998-01-01

This document describes the Instream Flow Methodology in its entirety. This also is to serve as a comprehensive introductory textbook on IFIM for training courses as it contains the most complete and comprehensive description of IFIM in existence today. This should also serve as an official guide to IFIM in publication to counteract the misconceptions about the methodology that have pervaded the professional literature since the mid-1980's as this describes IFIM as it is envisioned by its developers. The document is aimed at the decisionmakers of management and allocation of natural resources in providing them an overview; and to those who design and implement studies to inform the decisionmakers. There should be enough background on model concepts, data requirements, calibration techniques, and quality assurance to help the technical user design and implement a cost-effective application of IFIM that will provide policy-relevant information. Some of the chapters deal with basic organization of IFIM, procedural sequence of applying IFIM starting with problem identification, study planning and implementation, and problem resolution.

Comparison and Validation of Hydrological E-Flow Methods through Hydrodynamic Modelling

NASA Astrophysics Data System (ADS)

Kuriqi, Alban; Rivaes, Rui; Sordo-Ward, Alvaro; Pinheiro, António N.; Garrote, Luis

2017-04-01

Flow regime determines physical habitat conditions and local biotic configuration. The development of environmental flow guidelines to support the river integrity is becoming a major concern in water resources management. In this study, we analysed two sites located in southern part of Portugal, respectively at Odelouca and Ocreza Rivers, characterised by the Mediterranean climate. Both rivers are almost in pristine condition, not regulated by dams or other diversion construction. This study presents an analysis of the effect on fish habitat suitability by the implementation of different hydrological e-flow methods. To conduct this study we employed certain hydrological e-flow methods recommended by the European Small Hydropower Association (ESHA). River hydrology assessment was based on approximately 30 years of mean daily flow data, provided by the Portuguese Water Information System (SNIRH). The biological data, bathymetry, physical and hydraulic features, and the Habitat Suitability Index for fish species were collected from extensive field works. We followed the Instream Flow Incremental Methodology (IFIM) to assess the flow-habitat relationship taking into account the habitat suitability of different instream flow releases. Initially, we analysed fish habitat suitability based on natural conditions, and we used it as reference condition for other scenarios considering the chosen hydrological e-flow methods. We accomplished the habitat modelling through hydrodynamic analysis by using River-2D model. The same methodology was applied to each scenario by considering as input the e-flows obtained from each of the hydrological method employed in this study. This contribution shows the significance of ecohydrological studies in establishing a foundation for water resources management actions. Keywords: ecohydrology, e-flow, Mediterranean rivers, river conservation, fish habitat, River-2D, Hydropower.

A Conceptual Model For Effluent-Dependent Riverine Environments

NASA Astrophysics Data System (ADS)

Murphy, M. T.; Meyerhoff, R. D.; Osterkamp, W. R.; Smith, E. L.; Hawkins, R. H.

2001-12-01

The Arid West Water Quality Research Project (WQRP) is a multi-year, EPA-funded scientific endeavor directed by the Pima County, Wastewater Management Department in southern Arizona and focussed upon several interconnected ecological questions. These questions are crucial to water quality management in the arid and semi arid western US. A key component has been the ecological, hydrological and geomorphological investigation of habitat created by the discharge of treated effluent into ephemeral streams. Such environments are fundamentally different from the dry streams or rivers they displace; however, they are clearly not the perennial streams they superficially resemble. Under Arizona State regulations, such streams can bear the use designation of "Effluent Dependent Waters," or EDWs. Before this investigation, a hydrological/ecological conceptual model for these unique ecosystems had not been published. We have constructed one for general review that is designed to direct future work in the WQRP. The project investigated ten representative, yet contrasting EDW sites distributed throughout arid areas of the western US, to gather both historical and reconnaissance level field data, including in-stream and riparian, habitat and morphometric fluvial data. In most cases, the cross sectional area of the prior channel is oversized relative to the discharge of the introduced effluent. Where bed control is absent, the channels are incised downstream of the discharge point, further suggesting a disequilibrium between the channel and the regulated effluent flow. Several of the studied stream systems primarily convey storm water and are aggradational, exhibiting braided or anastomizing channels, high energy bedforms, and spatially dynamic interfluves. Active channels are formed in response to individual storm events and can be highly dynamic in both location and cross-sectional morphology. This poses a geomorphological challenge in the selection of a discharge point. We structured the conceptual model around accepted riverine ecological models but with important departures signaling the unique characteristics of EDW communities. In many cases, in-stream habitat values were naturally limited by substrate, flow regimes, or other pre-discharge conditions. Our model is designed to give terrestrial habitat equal footing with in-stream resources in ecological assessment techniques. In the arid West, where in-stream water resources are becoming increasingly limited, EDWs offer important refugia and corridors for neotropical migratory birds and other habitat-limited wildlife species. These beneficial uses require different hydrological tools than in-stream systems for assessing habitat health.

Short-term Hydropower Reservoir Operations in Chile's Central Interconnected System: Tradeoffs between Hydrologic Alteration and Economic Performance

NASA Astrophysics Data System (ADS)

Olivares, M. A.

2011-12-01

Hydropower accounts for about 50% of the installed capacity in Chile's Central Interconnected System (CIS) and new developments are envisioned in the near future. Large projects involving reservoirs are perceived negatively by the general public. In terms of operations, hydropower scheduling takes place at monthly, weekly, daily and hourly intervals, and operations at each level affect different environmental processes. Due to its ability to quickly and inexpensively respond to short-term changes in demand, hydropower reservoirs often are operated to provide power during periods of peak demand. This operational scheme, known as hydropeaking, changes the hydrologic regime by altering the rate and frequency of changes in flow magnitude on short time scales. To mitigate impacts on downstream ecosystems, operational constraints -typically minimum instream flows and maximum ramping rates- are imposed on hydropower plants. These operational restrictions limit reduce operational flexibility and can reduce the economic value of energy generation by imposing additional costs on the operation of interconnected power systems. Methods to predict the degree of hydrologic alteration rely on statistical analyses of instream flow time series. Typically, studies on hydrologic alteration use historical operational records for comparison between pre- and post-dam conditions. Efforts to assess hydrologic alteration based on future operational schemes of reservoirs are scarce. This study couples two existing models: a mid-term operations planning and a short-term economic dispatch to simulate short-term hydropower reservoir operations under different future scenarios. Scenarios of possible future configurations of the Chilean CIS are defined with emphasis on the introduction of non-conventional renewables (particularly wind energy) and large hydropower projects in Patagonia. Both models try to reproduce the actual decision making process in the Chilean Central Interconnected System (CIS). Chile's CIS is structured as a mandatory pool with audited costs and therefore the economic dispatch can be formulated as a cost minimization problem. Consequently, hydropower reservoir operations are controlled by the ISO. Reservoirs with the most potential to cause short-term hydrologic alteration were identified from existing operational records. These records have also been used to validate our simulated operations. Results in terms of daily and subdaily hydrologic alteration as well as the economic performance of the CIS are presented for alternative energy matrix scenarios. Tradeoff curves representing the compromise between indicators of hydrologic alteration and economic indicators of the CIS operation are developed.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for Little Laughery Creek, Ripley and Franklin counties, Indiana

USGS Publications Warehouse

Crawford, Charles G.; Wilber, William G.; Peters, James G.

1980-01-01

A digital model calibrated to conditions in Little Laughery Creek triutary and Little Laughery Creek, Ripley and Franklin Counties, Ind., was used to predict alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. Natural streamflow during the summer and annual 7-day, 10-year low flow is zero. Headwater flow upstream from the wastewater-treatment facilities consists solely of process cooling water from an industrial discharger. This flow is usually less than 0.5 cubic foot per second. Consequently, benefits from dilution are minimal. As a result, current and projected ammonia-nitrogen concentrations from the municipal discharges will result in in-stream ammonia-nitrogen concentrations that exceed the Indiana ammonia-nitrogen toxicity standards (maximum stream ammonia-nitrogen concentrations of 2.5 and 4.0 milligrams per liter during summer and winter low flows, respectively). Benthic-oxygen demand is probably the most significant factor affecting Little Laughery Creek and is probably responsible for the in-stream dissolved-oxygen concentration being less than the Indiana stream dissolved-oxygen standard (5.0 milligrams per liter) during two water-quality surveys. After municipal dischargers complete advanced waste-treatment facilities, benthic-oxygen demand should be less significant in the stream dissolved-oxygen dynamics. (USGS)

Fish passage and abundance around grade control structures on incised streams

USGS Publications Warehouse

Thomas, J.T.; Papanicolaou, A.N.; Pierce, C.L.; Dermisis, D.C.; Litvan, M.E.; Larson, C.J.

2009-01-01

This paper summarizes research from separate studies of fish passage over weirs (Larson et al., 2004; Litvan, 2006; Litvan, et al., 2008a-c) and weir hydraulics (Papanicolaou and Dermisis, 2006; Papanicolaou and Dermisis, in press). Channel incision in the deep loess region of western Iowa has caused decreased biodiversity because streams have high sediment loads, altered flow regimes, lost habitat, and lost lateral connectivity with their former floodplains. In-stream grade control structures (GCS) are built to prevent further erosion, protect infrastructure, and reduce sediment loads. However, GCS can have a detrimental impact on fisheries abundance and migration, biodiversity, and longitudinal connectivity. Fish mark-recapture studies were performed on stretches of streams with and without GCS. GCS with vertical or 1:4 (rise/run) downstream slopes did not allow fish migration, but GCS with slopes ??? 1:15 did. GCS sites were characterized by greater proportions of pool habitat, maximum depths, fish biomass, slightly higher index of biotic integrity (IBI) scores, and greater macroinvertebrate abundance and diversity than non-GCS sites. After modification of three GCS, IBI scores increased and fish species exhibiting truncated distributions before were found throughout the study area. Another study examined the hydraulic performance of GCS to facilitate unimpeded fish passage by determining the mean and turbulent flow characteristics in the vicinity of the GCS via detailed, non-intrusive field tests. Mean flow depth (Y) and velocity (V) atop the GCS were critical for evaluating GCS performance. Turbulent flow measurements illustrated that certain GCS designs cause sudden constrictions which form eddies large enough to disorient fish. GCS with slopes ??? 1:15 best met the minimum requirements to allow catfish passage of a flow depth of ??? 0.31 m and a mean flow velocity of ??? 1.22 m/s. ?? 2009 ASCE.

HYDROLOGICALLY-BASED CLASSIFICATION AS A TOOL TO REDUCE BACKGROUND VARIATION IN LAND USE - OR NUTRIENT - RESPONSE RELATIONSHIPS IN LAKE MICHIGAN COASTAL RIVERINE WETLANDS

EPA Science Inventory

Flow-based watershed classes provide useful strata for sampling and assessment schemes both for instream condition and condition of downstream receiving waters, and may provide useful strata for development of nutrient criteria.

Assessment of freshwater ecosystem services in the Beas River Basin, Himalayas region, India

NASA Astrophysics Data System (ADS)

Ncube, Sikhululekile; Beevers, Lindsay; Adeloye, Adebayo J.; Visser, Annie

2018-06-01

River systems provide a diverse range of ecosystem services, examples include: flood regulation (regulating), fish (provisioning), nutrient cycling (supporting) and recreation (cultural). Developing water resources through the construction of dams (hydropower or irrigation) can enhance the delivery of provisioning ecosystem services. However, these hydrologic alterations result in reductions in less tangible regulating, cultural and supporting ecosystem services. This study seeks to understand how multiple impoundments, abstractions and transfers within the upper Beas River Basin, Western Himalayas, India, are affecting the delivery of supporting ecosystem services. Whilst approaches for assessing supporting ecosystem services are under development, the immediate aim of this paper is to set out a framework for their quantification, using the macroinvertebrate index Lotic-Invertebrate Index for Flow Evaluation (LIFE). LIFE is a weighted measure of the flow velocity preferences of the macroinvertebrate community. Flow records from multiple gauging stations within the basin were used to investigate flow variability at seasonal, inter-annual and decadal time scales. The findings show that both mean monthly and seasonal cumulative flows have decreased over time in the Beas River Basin. A positive hydroecological relationship between LIFE and flow was also identified, indicative of macroinvertebrate response to seasonal changes in the flow regime. For example, high LIFE scores (7.7-9.3) in the winter and summer seasons indicate an abundance of macroinvertebrates with a preference for high flows; this represents a high potential for instream supporting ecosystem services delivery. However, further analysis is required to understand these hydroecological interactions in the study basin and the impact on instream supporting ecosystem services delivery.

Wenatchee River, Washington, Water Temperature Modeling and Assessment Using Remotely Sensed Thermal Infrared and Instream Recorded Data

NASA Astrophysics Data System (ADS)

Cristea, N. C.; Burges, S. J.

2004-12-01

The stream water spatial and temporal temperature patterns of the Wenatchee River, WA are assessed based on temperature data recorded by instream data loggers in the dry season of 2002 and thermal infrared imagery from August 16th 2002. To gain insights into the possible thermal behavior of the river, the stream temperature model Qual2K (Chapra and Pelletier, 2003) is extended beyond its calibration (10-16 August 2002) and confirmation (9-11 September 2002) periods for use with different meteorological, shade and flow conditions. The temperature longitudinal profile of the Wenatchee River is influenced by the temperature regime in Lake Wenatchee, the source of the Wenatchee River. Model simulations performed at 7-day average with 2-year return period flow conditions show that the potential (maximum average across all reaches) temperature (the temperature that would occur under natural conditions) is about 19.8 deg. C. For the 7-day average with 10-year return period flow conditions the potential temperature increases to about 21.2 deg. C. The simulation results show that under normal flow and meteorological conditions the water temperature exceeds the current water quality standards. Model simulations performed under the 7-day average with 10-year return period flow conditions and a climate change scenario show that the average potential temperature across all reaches can increase by as much as 1.3 deg. C compared to the case where climate change impact is not taken into account. Thermal infrared (TIR) derived stream temperature data were useful for describing spatial distribution patterns of the Wenatchee River water temperature. The TIR and visible band images are effective tools to map cold water refugia for fish and to detect regions that can be improved for fish survival. The images collected during the TIR survey and the TIR derived stream temperature longitudinal profile helps pinpoint additional instream monitoring locations that avoid regions of backwater, cool or warm pockets or regions affected by tributary influence, that are inappropriate for stream temperature monitoring. Groundwater input is difficult to detect from the TIR images in the case of a relatively large river such the Wenatchee River.

Defining interactions of in-stream hydrokinetic devices in the Tanana River, Alaska

NASA Astrophysics Data System (ADS)

Johnson, J.; Toniolo, H.; Seitz, A. C.; Schmid, J.; Duvoy, P.

2012-12-01

The acceptance, performance, and sustainability of operating in-stream hydrokinetic power generating devices in rivers depends on the impact of the river environment on hydrokinetic infrastructure as well as its impact on the river environment. The Alaska Hydrokinetic Energy Research Center (AHERC) conducts hydrokinetic "impact" and technology studies needed to support a sustainable hydrokinetic industry in Alaska. These include completed and ongoing baseline studies of river hydrodynamic conditions (river stage, discharge, current velocity, power, and turbulence; suspended and bed load sediment transport), ice, fish populations and behavior, surface and subsurface debris flows, and riverbed conditions. Technology and methods studies to minimize the effect of debris flows on deployed turbine system are in-progress to determine their effectiveness at reducing the probability of debris impact, diverting debris and their affect on available river power for conversion to electricity. An anchor point has been placed in the main flow just upstream of Main (Figure 1) to support projects and in preparation for future projects that are being planned to examine hydrokinetic turbine performance including power conversion efficiency, turbine drag and anchor chain loads, wake generation and effects on fish. Baseline fish studies indicate that hydrokinetic devices at the test site will have the most potential interactions with Pacific salmon smolts during their down-migration to the ocean in May and June. At the AHERC test site, the maximum turbulent kinetic energy (TKE) occurs just down stream from the major river bends (e.g., 000 and near the railroad bridge [upper center of the figure]) and over a deep hole at 440 (Figure 1), Minimum TKE occurs between main and 800. River current velocity measurements and simulations of river flow from 000 downstream past the railroad bridge indicate that the most stable current in the river reach is between Main and 800. The stable current and low TKE between Main and 800 indicate that this section of river may be the best site for deploying hydrokinetic devices. Woody debris exists as individual pieces or as large tangled masses on the surface, as full depth vertically oriented debris moving down river and as submerged debris posing a potential hazard to surface or subsurface deployed hydrokinetic devices. Submerged debris consists of logs, root balls, and small (mulch-like) debris. A surface debris diversion device has been tested and shown to be effective at diverting isolated debris and may reduce hazards for surface mounted devices.Figure 1. AHERC Tanana River test site at Nenana, AK.

Influence of Drought and Total Phosphorus on Diel pH in Wadeable Streams: Implications for Ecological Risk Assessment of Ionizable Contaminants

EPA Science Inventory

Climatological influences on site-specific ecohydrology are particularly germane in semiarid regions where instream flows are strongly influenced by effluent discharges. Because many traditional and emerging aquatic contaminants, such as pharmaceuticals, are ionizable, we examin...

ESTIMATION OF TOTAL DISSOLVED NITRATE LOAD IN NATURAL STREAM FLOWS USING AN IN-STREAM MONITOR

EPA Science Inventory

Estuaries respond rapidly to rain events and the nutrients carried by inflowing rivers such that discrete samples at weekly or monthly intervals are inadequate to catch the maxima and minima in nutrient variability. To acquire data with sufficient sampling frequency to realistica...

New methods for modeling stream temperature using high resolution LiDAR, solar radiation analysis and flow accumulated values

EPA Science Inventory

In-stream temperature directly effects a variety of biotic organisms, communities and processes. Changes in stream temperature can render formally suitable habitat unsuitable for aquatic organisms, particularly native cold water species that are not able to adjust. In order to an...

Geochemical responses of forested catchments to bark beetle infestation: Evidence from high frequency in-stream electrical conductivity monitoring

NASA Astrophysics Data System (ADS)

Su, Ye; Langhammer, Jakub; Jarsjö, Jerker

2017-07-01

Under the present conditions of climate warming, there has been an increased frequency of bark beetle-induced tree mortality in Asia, Europe, and North America. This study analyzed seven years of high frequency monitoring of in-stream electrical conductivity (EC), hydro-climatic conditions, and vegetation dynamics in four experimental catchments located in headwaters of the Sumava Mountains, Central Europe. The aim was to determine the effects of insect-induced forest disturbance on in-stream EC at multiple timescales, including annual and seasonal average conditions, daily variability, and responses to individual rainfall events. Results showed increased annual average in-stream EC values in the bark beetle-infected catchments, with particularly elevated EC values during baseflow conditions. This is likely caused by the cumulative loading of soil water and groundwater that discharge excess amounts of substances such as nitrogen and carbon, which are released via the decomposition of the needles, branches, and trunks of dead trees, into streams. Furthermore, we concluded that infestation-induced changes in event-scale dynamics may be largely responsible for the observed shifts in annual average conditions. For example, systematic EC differences between baseflow conditions and event flow conditions in relatively undisturbed catchments were essentially eliminated in catchments that were highly disturbed by bark beetles. These changes developed relatively rapidly after infestation and have long-lasting (decadal-scale) effects, implying that cumulative impacts of increasingly frequent bark beetle outbreaks may contribute to alterations of the hydrogeochemical conditions in more vulnerable mountain regions.

Large wood and in-stream habitat for juvenile coho salmon and larval lampreys in a Pacific Northwest stream

USGS Publications Warehouse

Gonzalez, Rosalinda; Dunham, Jason B.; Lightcap, Scott W.; McEnroe, Jeffery R.

2017-01-01

The influences of large wood on Pacific salmon are well-studied, but studies of nonsalmonid species such as lampreys are uncommon. To address this need, we evaluated the potential effects of large wood on larval lampreys (Pacific Lamprey, Entosphenus tridentatus; and potentially Western Brook Lamprey Lampetra richardsoni), as well as juvenile Coho Salmon Oncorhynchus kisutch, in a small coastal Oregon stream. Our objectives were to 1) identify in-stream habitat characteristics associated with the presence of larval lampreys and abundance of juvenile Coho Salmon; and 2) evaluate how these characteristics were associated with in-stream wood. To address habitat use, we quantified presence of larval lampreys in 92 pools and abundance of juvenile Coho Salmon in 44 pools during summer low flows. We focused on a study reach where large wood was introduced into the stream between 2008 and 2009. Results indicated that presence of larval lampreys was significantly associated with availability of fine sediment and deeper substrate. The abundance of juvenile Coho Salmon (fish/pool) was strongly associated with pool surface area and to a weaker extent with the proportion of cobble and boulder substrates in pools. Pools with wood, regardless of whether they were formed by wood, had significantly greater coverage of fine sediment, deeper substrate, and greater pool surface area. Taken together, these results suggest that in-stream wood can provide habitat associated with presence of larval lampreys and greater abundance of juvenile Coho Salmon.

Modeling studies of water consumption for transportation fuel options: Hawaii, US-48

NASA Astrophysics Data System (ADS)

King, C. W.; Webber, M. E.

2011-12-01

There are now major drivers to move from petroleum transportation: moving to low-carbon transport life cycles for climate change mitigation, fuel diversity to reduce reliance on imported oil, and economic concerns regarding the relatively high price of oil ( $100/barrel) and the resulting impact on discretionary income. Unfortunately many transportation fuel alternatives also have some environmental impacts, particularly with regard to water consumption and biodiversity. In this presentation we will discuss the water and energy sustainability struggle ongoing in Hawai'i on the island of Maui with a brief history and discussion of energy and water modeling scenarios. The vast majority of surface water on Maui is diverted via man-made ditches for irrigation on sugar cane plantations. Maui currently allocates between 250 and 300 million gallons per day (Mgal/d) of irrigation water for sugarcane cultivation each day, and it is likely that the island could support a biofuel-focused sugarcane plantation by shifting production focus from raw sugar to ethanol. However, future water availability is likely to be less than existing water availability because Maui is growing, more water is being reserved for environmental purposes, and precipitation levels are on decline for the past two decades and some expect this trend to continue. While Maui residents cannot control precipitation patterns, they can control the levels of increased requirements for instream flow in Maui's streams. The Hawaii State Commission on Water Resource Management (CWRM) sets instream flow standards, and choosing not to restore instream flow could have what many locals consider negative environmental and cultural impacts that must be weighed against the effects of reducing surface water availability for agriculture. Instream flow standards that reduce legal withdrawals for streams that supply irrigation water would reduce the amount of surface water available for biofuel crop irrigation. Environmental flow restoration that has already been ordered requires that an additional 18.5 Mgal/d from East Maui streams and 12.5 Mgal/d from West Maui streams not be diverted for irrigation or other uses. Further environmental flow requirements based on a habitat-protective standard enumerated by the Department of Aquatic Resources could be an additional 45 Mgal/d. Thus, it is conceivable that over the next several years a total of 76 Mgal/d, which is 20%-30% of the irrigation water at existing sugarcane farms, could be appropriated away from agriculture on Maui. Many locals have never viewed the large-scale diversion of stream flow for agriculture as legitimate. Now that much of the plantation agriculture in Hawai'i has shut down due to lack of competitive economics, the discussion of the priority for use of 'old' agricultural water is prompting more water to be left in streams. At the same time, Hawai'i has goals for energy sustainability that include producing biofuels. Thus, Maui is a microcosm of the struggle for energy and water sustainability. Brief discussions of other studies on the water needs for transportation fuel options for the continental 48 U.S. states will also be presented.

Changes in phosphorus concentrations and loads in the Assabet River, Massachusetts, October 2008 through April 2014

USGS Publications Warehouse

Savoie, Jennifer G.; DeSimone, Leslie A.; Mullaney, John R.; Zimmerman, Marc J.; Waldron, Marcus C.

2016-10-24

Treated effluent discharged from municipal wastewater-treatment plants to the Assabet River in central Massachusetts includes phosphorus, which leads to increased growth of nuisance aquatic plants that decrease the river’s water quality and aesthetics in impounded reaches during the growing season. To improve the river’s water quality and aesthetics, the U.S. Environmental Protection Agency approved a total maximum daily load for phosphorus in 2004 that directed the wastewater-treatment plants to reduce the amount of total phosphorus discharged to the river by 2012. The permitted total phosphorus monthly average of 0.75 milligrams per liter during the aquatic plant growing season (April 1 through October 31) was reduced by the total maximum daily load to a target of 0.1 milligrams per liter by 2012, and the nongrowing-season limit was unchanged at 1.0 milligrams per liter.From October 2008 through April 2014, the U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, measured streamflow and collected weekly flow-proportional, composite samples of water from the Assabet River for analysis of concentrations of total phosphorus and orthophosphate. Streamflow and concentration data were used to estimate total phosphorus and orthophosphate loads in the river. The purpose of this monitoring effort was to evaluate phosphorus concentrations and loads in the river before, during, and after the wastewater-treatment-plant upgrades and to assess the effects of seasonal differences in permitted discharges. The locations of water-quality-monitoring stations, with respect to the Hudson and Ben Smith impoundments, enabled examination of effects of phosphorus entering and leaving the impoundments.Annual median concentrations of total phosphorus in wastewater-treatment plants were reduced by more than 80 percent with the plant upgrades. Measured instream annual median concentrations of total phosphorus in the Assabet River decreased by about 38 to 50 percent at three of the four monitoring stations following the wastewater-treatment-plant upgrades. At the station farthest upstream, the median total phosphorus concentration remained unchanged throughout the study; this may be attributed to the site location and potential resuspension of particulate organic matter during periods of increased streamflow. Annual median loads from the wastewater-treatment plants were reduced by up to 91 percent following the upgrades, instream annual median total phosphorus loads at the three downstream stations decreased by 71 to 76 percent, and instream orthophosphate loads at the three downstream stations decreased by 79 to 87 percent.Seasonal fluctuations (growing versus nongrowing) of total phosphorus and orthophosphate were observed instream before the upgrades. However, after the upgrades, fluctuations in phosphorus released from the treatment plants were slight and seasonal changes were typically not observed instream.Annual loads entering and leaving the two impoundments were inconclusive in determining whether the impoundments were sources or sinks of total phosphorus during the study. Total phosphorus loads entering the Hudson impoundment were consistently greater than those leaving; however, there was uncertainty about the loads at the monitoring station upstream from this impoundment. At the Ben Smith impoundment, total phosphorus and orthophosphate loads downstream were slightly greater than those upstream from the impoundment, but the differences may reflect additions from tributaries and overland runoff.Estimated instream total phosphorus concentrations and loads indicated that the decreases in total phosphorus in wastewater-treatment-plant discharges were accompanied by reductions measured in the Assabet River. A statistical analysis which incorporates the effect of varying flow conditions demonstrated significant reductions in total phosphorus concentrations after the wastewater-treatment-plant upgrades at three of the four instream monitoring stations. No significant change was observed at the most upstream location, the Assabet River at Port Street at Hudson, Massachusetts (station number 01096835), which may have been affected by flow-related resuspension of particulate phosphorus.

Instream cover and shade mediate avian predation on trout in semi-natural streams

USGS Publications Warehouse

Penaluna, Brooke E.; Dunham, Jason B.; Noakes, David L. G.

2015-01-01

Piscivory by birds can be significant, particularly on fish in small streams and during seasonal low flow when available cover from predators can be limited. Yet, how varying amounts of cover may change the extent of predation mortality from avian predators on fish is not clear. We evaluated size-selective survival of coastal cutthroat trout (Oncorhynchus clarkii clarkii) in replicated semi-natural stream sections. These sections provided high (0.01 m2 of cover per m2 of stream) or low (0.002 m2 of cover per m2 of stream) levels of instream cover available to trout and were closed to emigration. Each fish was individually tagged, allowing us to track retention of individuals during the course of the 36-day experiment, which we attributed to survival from predators, because fish had no other way to leave the streams. Although other avian predators may have been active in our system and not detected, the only predator observed was the belted kingfisher Megaceryle alcyon, which is known to prey heavily on fish. In both treatments, trout >20.4 cm were not preyed upon indicating an increased ability to prey upon on smaller individuals. Increased availability of cover improved survival of trout by 12% in high relative to low cover stream sections. Trout also survived better in stream sections with greater shade, a factor we could not control in our system. Collectively, these findings indicate that instream cover and shade from avian predators can play an important role in driving survival of fish in small streams or during periods of low flow.

An unexpected truth: increasing nitrate loading can decrease nitrate export from watersheds

NASA Astrophysics Data System (ADS)

Askarizadeh Bardsiri, A.; Grant, S. B.; Rippy, M.

2015-12-01

The discharge of anthropogenic nitrate (e.g., from partially treated sewage, return flows from agricultural irrigation, and runoff from animal feeding operations) to streams can negatively impact both human and ecosystem health. Managing these many point and non-point sources to achieve some specific end-point—for example, reducing the annual mass of nitrate exported from a watershed—can be a challenge, particularly in rapidly growing urban areas. Adding to this complexity is the fact that streams are not inert: they too can add or remove nitrate through assimilation (e.g., by stream-associated plants and animals) and microbially-mediated biogeochemical reactions that occur in streambed sediments (e.g., respiration, ammonification, nitrification, denitrification). By coupling a previously published correlation for in-stream processing of nitrate [Mulholland et al., Nature, 2008, 452, 202-205] with a stream network model of the Jacksons Creek watershed (Victoria, Australia) I demonstrate that managing anthropogenic sources of stream nitrate without consideration of in-stream processing can result in a number of non-intuitive "surprises"; for example, wastewater effluent discharges that increase nitrate loading but decrease in-stream nitrate concentrations can reduce the mass of nitrate exported from a watershed.

Assessment of arrays of in-stream tidal turbines in the Bay of Fundy.

PubMed

Karsten, Richard; Swan, Amanda; Culina, Joel

2013-02-28

Theories of in-stream turbines are adapted to analyse the potential electricity generation and impact of turbine arrays deployed in Minas Passage, Bay of Fundy. Linear momentum actuator disc theory (LMADT) is combined with a theory that calculates the flux through the passage to determine both the turbine power and the impact of rows of turbine fences. For realistically small blockage ratios, the theory predicts that extracting 2000-2500 MW of turbine power will result in a reduction in the flow of less than 5 per cent. The theory also suggests that there is little reason to tune the turbines if the blockage ratio remains small. A turbine array model is derived that extends LMADT by using the velocity field from a numerical simulation of the flow through Minas Passage and modelling the turbine wakes. The model calculates the resulting speed of the flow through and around a turbine array, allowing for the sequential positioning of turbines in regions of strongest flow. The model estimates that over 2000 MW of power is possible with only a 2.5 per cent reduction in the flow. If turbines are restricted to depths less than 50 m, the potential power generation is reduced substantially, down to 300 MW. For large turbine arrays, the blockage ratios remain small and the turbines can produce maximum power with a drag coefficient equal to the Betz-limit value.

Detecting biological responses to flow management: Missed opportunities; future directions

USGS Publications Warehouse

Souchon, Y.; Sabaton, C.; Deibel, R.; Reiser, D.; Kershner, J.; Gard, M.; Katopodis, C.; Leonard, P.; Poff, N.L.; Miller, W.J.; Lamb, B.L.

2008-01-01

The conclusions of numerous stream restoration assessments all around the world are extremely clear and convergent: there has been insufficient appropriate monitoring to improve general knowledge and expertise. In the specialized field of instream flow alterations, we consider that there are several opportunities comparable to full-size experiments. Hundreds of water management decisions related to instream flow releases have been made by government agencies, native peoples, and non-governmental organizations around the world. These decisions are based on different methods and assumptions and many flow regimes have been adopted by formal or informal rules and regulations. Although, there have been significant advances in analytical capabilities, there has been very little validation monitoring of actual outcomes or research related to the response of aquatic dependent species to new flow regimes. In order to be able to detect these kinds of responses and to better guide decision, a general design template is proposed. The main steps of this template are described and discussed, in terms of objectives, hypotheses, variables, time scale, data management, and information, in the spirit of adaptive management. The adoption of such a framework is not always easy, due to differing interests of actors for the results, regarding the duration of monitoring, nature of funding and differential timetables between facilities managers and technicians. Nevertheless, implementation of such a framework could help researchers and practitioners to coordinate and federate their efforts to improve the general knowledge of the links between the habitat dynamics and biological aquatic responses. Copyright ?? 2008 John Wiley & Sons, Ltd.

New methods for modeling stream temperature using high resolution LiDAR, solar radiation analysis and flow accumulated values to predict stream temperature

EPA Science Inventory

In-stream temperature directly effects a variety of biotic organisms, communities and processes. Changes in stream temperature can render formally suitable habitat unsuitable for aquatic organisms, particularly native cold water species that are not able to adjust. In order to...

Quantifying the production of dissolved organic nitrogen in headwater streams using 15N tracer additions

Treesearch

Laura T. Johnson; Jennifer L. Tank; Robert O. Hall; Patrick J. Mullholland; Stephen K. Hamilton; H. Maurice Valett; Jackson R. Webster; Melody J. Bernot; William H. McDowell; Bruce J. Peterson; Suzanne M. Thomas

2013-01-01

Most nitrogen (N) assimilation in lake and marine ecosystems is often subsequently released via autochthonous dissolved organic nitrogen (DON) production, but autochthonous DON production has yet to be quantified in flowing waters. We measured in-stream DON production following 24 h 15N-nitrate (NO3-...

Effects of in-stream concrete structures on the pH level of water.

DOT National Transportation Integrated Search

1976-01-01

The pH values above and below concrete structures in streams on nine active construction projects throughout the state were determined. It was concluded that for streams with flow rates of 0.3 to 111.25 cfs (0.01 to 3.2 cubic meter/see) the variation...

Field testing existence values for riparian ecosystems

Treesearch

John W. Duffield; Chris J. Neher; David A. Patterson; Patricia A. Champ

2007-01-01

This paper presents preliminary findings on a cash and contingent valuation (cv) experiment. The study replicates major elements of an earlier (1990) experiment, which solicited hypothetical and actual donations to benefit instream flows for Montana fisheries. Extensions of the earlier work include: repeat contacts to increase response rate, follow-up of the contingent...

Modeling E. Coli release and transport in a creek during artificial high-flow events

USDA-ARS?s Scientific Manuscript database

In-stream fate and transport of E. Coli, is a leading indicator of microbial contamination of natural waters, and so needs to be understood to eventually minimize surface water contamination by microbial organisms. The objective of this work was to simulate E. Coli release and transport from soil se...

78 FR 46365 - Quarterly Status Report of Water Service, Repayment, and Other Water-Related Contract Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

... Stream Commission O&M Operation and Maintenance P-SMBP Pick-Sloan Missouri Basin Program PPR Present... stored water from Applegate Reservoir (a USACE project) for irrigation use in exchange for the transfer... of Oregon for instream flow use. Completed contract action: 11. Prineville Reservoir Water Users...

Photographic guidance for selecting flow resistance coefficients in high-gradient channels

Treesearch

Steven E. Yochum; Francesco Comiti; Ellen Wohl; Gabrielle C. L. David; Luca Mao

2014-01-01

Photographic guidance is presented to assist with the estimation of Manning’s n and Darcy-Weisbach f in high-gradient plane-bed, step-pool, and cascade channels. Reaches both with and without instream wood are included. These coefficients are necessary for the estimation of reachaverage velocity, energy loss, and...

Supplement Analysis for the Watershed Management Program EIS (DOE/EIS-0265/SA-105) - Water Entity (Washington Water Trust 2003)

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

Yarde, Richard

2003-06-13

BPA proposes to fund several water rights acquisition projects proposed by the Washington Water Trust (WWT). The funding will be administered by the National Fish and Wildlife Foundation, the entity administering the Columbia Basin Water Transactions Program, initiated under RPA 151 of the National Marine Fisheries Service’s 2000 Biological Opinion on the Operation of the Federal Columbia River Power System. The water rights acquired by the WWT will be left instream to increase flow and improve water quality. Increasing instream flow of water-limited streams benefits fish listed under the Endangered Species Act. The three projects proposed by the WWT include:more » renewing a lease for 0.43 cubic feet per second (cfs) in the Methow River for three years; renewing a lease of 1.29 cfs to be protected in a 0.75 mile stretch of Gold Creek, a tributary to the Methow River, for one year; and renewing a lease of 0.17 cfs in a 0.2 mi stretch of Frazer Creek, a tributary of the Methow River, for two years.« less

Assessing the Effects of Water Rights Purchases on Dissolved Oxygen, Stream Temperatures, and Fish Habitat

NASA Astrophysics Data System (ADS)

Mouzon, N. R.; Null, S. E.

2014-12-01

Human impacts from land and water development have degraded water quality and altered the physical, chemical, and biological integrity of Nevada's Walker River. Reduced instream flows and increased nutrient concentrations affect native fish populations through warm daily stream temperatures and low nightly dissolved oxygen concentrations. Water rights purchases are being considered to maintain instream flows, improve water quality, and enhance habitat for native fish species, such as Lahontan cutthroat trout. This study uses the River Modeling System (RMSv4), an hourly, physically-based hydrodynamic and water quality model, to estimate streamflows, temperatures, and dissolved oxygen concentrations in the Walker River. We simulate thermal and dissolved oxygen changes from increased streamflow to prioritize the time periods and locations that water purchases most enhance native trout habitat. Stream temperatures and dissolved oxygen concentrations are proxies for trout habitat. Monitoring results indicate stream temperature and dissolved oxygen limitations generally exist in the 115 kilometers upstream of Walker Lake (about 37% of the study area) from approximately May through September, and this reach currently acts as a water quality barrier for fish passage.

Hydrological Controls on Dissolved Organic Matter Quality and Export in a Coastal River System in Southeastern USA

NASA Astrophysics Data System (ADS)

Bhattacharya, R.; Osburn, C. L.

2017-12-01

Dissolved organic matter (DOM) exported from river catchments can influence the biogeochemical processes in coastal environments with implications for water quality and carbon budget. High flow conditions are responsible for most DOM export ("pulses") from watersheds, and these events reduce DOM transformation and production by "shunting" DOM from river networks into coastal waters: the Pulse-Shunt Concept (PSC). Subsequently, the source and quality of DOM is also expected to change as a function of river flow. Here, we used stream dissolved organic carbon concentrations ([DOC]) along with DOM optical properties, such as absorbance at 350 nm (a350) and fluorescence excitation and emission matrices modeled by parallel factor analysis (PARAFAC), to characterize DOM source, quality and fluxes under variable flow conditions for the Neuse River, a coastal river system in the southeastern US. Observations were made at a flow gauged station above head of tide periodically between Aug 2011 and Feb 2013, which captured low flow periods in summer and several high flow events including Hurricane Irene. [DOC] and a350 were correlated and varied positively with river flow, implying that a large portion of the DOM was colored, humic and flow-mobilized. During high flow conditions, PARAFAC results demonstrated the higher influx of terrestrial humic DOM, and lower in-stream phytoplankton production or microbial degradation. However, during low flow, DOM transformation and production increased in response to higher residence times and elevated productivity. Further, 70% of the DOC was exported by above average flows, where 3-4 fold increases in DOC fluxes were observed during episodic events, consistent with PSC. These results imply that storms dramatically affects DOM export to coastal waters, whereby high river flow caused by episodic events primarily shunt terrestrial DOM to coastal waters, whereas low flow promotes in-stream DOM transformation and amendment with microbial DOM.

Conceptual model for quantifying pre-smolt production from flow-dependent physical habitat and water temperature

USGS Publications Warehouse

Williamson, S. C.; Bartholow, J. M.; Stalnaker, C. B.

1993-01-01

A conceptual model has been developed to test river regulation concepts by linking physical habitat and water temperature with salmonid population and production in cold water streams. Work is in progress to examine numerous questions as part of flow evaluation and habitat restoration programmes in the Trinity River of California and elsewhere. For instance, how much change in pre-smolt chinook salmon (Oncorhynchus tshawytscha) production in the Trinity River would result from a different annual instream allocation (i.e. up or down from 271 × 106 m3released in the late 1980s) and how much change in pre-smolt production would result from a different release pattern (i.e. different from the 8.5 m3 s−1 year-round release). The conceptual model is being used to: design, integrate and improve young-of-year population data collection efforts; test hypotheses that physical habitat significantly influences movement, growth and mortality of salmonid fishes; and analyse the relative severity of limiting factors during each life stage. The conceptual model, in conjunction with previously developed tools in the Instream Flow Incremental Methodology, should provide the means to more effectively manage a fishery resource below a regulated reservoir and to provide positive feedback to planning of annual reservoir operations.

Designing stream restoration structures using 3D hydro-morphodynamic numerical modeling

NASA Astrophysics Data System (ADS)

Khosronejad, A.; Kozarek, J. L.; Hill, C.; Kang, S.; Plott, R.; Diplas, P.; Sotiropoulos, F.

2012-12-01

Efforts to stabilize and restore streams and rivers across the nation have grown dramatically in the last fifteen years, with over $1 billion spent every year since 1990. The development of effective and long-lasting strategies, however, is far from trivial and despite large investments it is estimated that at least 50% of stream restoration projects fail. This is because stream restoration is today more of an art than a science. The lack of physics-based engineering standards for stream restoration techniques is best underscored in the design and installation of shallow, in-stream, low-flow structures, which direct flow away from the banks, protect stream banks from erosion and scour, and increase habitat diversity. Present-day design guidelines for such in-stream structures are typically vague and rely heavily on empirical knowledge and intuition rather than physical understanding of the interactions of the structures the flow and sediment transport processes in the waterway. We have developed a novel computer-simulation based paradigm for designing in stream structures that is based on state-of-the-art 3D hydro-morphodynamic modeling validated with laboratory and field-scale experiments. The numerical model is based on the Curvilinear Immersed Boundary (CURVIB) approach of Kang et al. and Khosronejad et al. (Adv. in Water Res. 2010, 2011), which can simulate flow and sediment transport processes in arbitrarily complex waterways with embedded rock structures. URANS or large-eddy simulation (LES) models are used to simulate turbulence. Transport of bed materials is simulated using the non-equilibrium Exner equation for the bed surface elevation coupled with a transport equation for suspended load. Extensive laboratory and field-scale experiments have been carried out and employed to validate extensively the computational model. The numerical model is used to develop a virtual testing environment within which one or multiple in-stream structures can be embedded in representative live-bed meandering waterways and simulated numerically to systematically investigate the sensitivity of various design and installation parameters on structure performance and reliability. Waterway geometries are selected by a statistical classification of rivers and streams to represent typical sand-bed and gravel-bed systems found in nature. Results will be presented for rock vanes, J-hook vanes and bendway weirs. Our findings provide novel physical insights into the effects of various in-stream structures on turbulent flow and sediment transport processes in meandering rivers, underscore these effects for different stream-bed materials, and demonstrate how such physics-based analysis can yield design guidelines that often challenge what is commonly done in practice today. To our knowledge, our work is the first systematic attempt to employ advanced numerical modeling coupled with massively parallel supercomputers to design hydraulic structures for stream restoration. This work was supported by NSF Grants EAR-0120914 and EAR-0738726, National Cooperative Highway Research Program Grant NCHRP-HR 24-33.

Rapid oxidation of geothermal arsenic(III) in streamwaters of the eastern Sierra Nevada

USGS Publications Warehouse

Wilkie, J.A.; Hering, J.G.

1998-01-01

Arsenic redox cycling was examined in source waters of the Los Angeles Aqueduct, specifically at Hot Creek, a tributary of the Owens River. Elevated arsenic concentrations in Hot Creek result from geothermal inputs. Total arsenic and As(III) concentrations were determined in the creek and in hot spring pools along its banks. Samples were processed in the field using anion-exchange columns to separate inorganic As(III) and As(V) species. Downstream of the geothermal inputs, decreasing contributions of As(III) to total arsenic concentrations indicated rapid in-stream oxidation of As(III) to As(V) with almost complete oxidation occurring within 1200 m. Based on assumed plug flow transport and a flow velocity of about 0.4 m/s, the pseudo- first-order half-life calculated for this reaction was approximately 0.3 h. Conservative transport of total dissolved arsenic was observed over the reach. Pseudo-first-order reaction rates determined for As(III) oxidation in batch studies conducted in the field with aquatic macrophytes and/or macrophyte surface matter were comparable to the in-stream oxidation rate observed along Hot Creek. In batch kinetic studies, oxidation was not observed after sterile filtration or after the addition of antibiotics, which indicates that bacteria attached to submerged macrophytes are mediating the rapid As(III) oxidation reaction.Arsenic redox cycling was examined in source waters of the Los Angeles Aqueduct, specifically at Hot Creek, a tributary of the Owens River. Elevated arsenic concentrations in Hot Creek result from geothermal inputs. Total arsenic and As(III) concentrations were determined in the creek and in hot spring pools along its banks. Samples were processed in the field using anion-exchange columns to separate inorganic As(III) and As(V) species. Downstream of the geothermal inputs, decreasing contributions of As(III) to total arsenic concentrations indicated rapid in-stream oxidation of As(III) to As(V) with almost complete oxidation occurring within 1200 m. Based on assumed plug flow transport and a flow velocity of about 0.4 m/s, the pseudo-first-order half-life calculated for this reaction was approximately 0.3 h. Conservative transport of total dissolved arsenic was observed over the reach. Pseudo-first-order reaction rates determined for As(III) oxidation in batch studies conducted in the field with aquatic macrophytes and/or macrophyte surface matter were comparable to the in-stream oxidation rate observed along Hot Creek. In batch kinetic studies, oxidation was not observed after sterile filtration or after the addition of antibiotics, which indicates that bacteria attached to submerged macrophytes are mediating the rapid As(III) oxidation reaction.

A Regional Guidebook for Conducting Functional Assessments of Wetland and Riparian Forests in the Ouachita Mountains and Crowley’s Ridge Regions of Arkansas

DTIC Science & Technology

2006-12-01

92–101. Bovee, K . D . 1982. A guide to stream habitat analysis using the in stream flow incremental methodology. Instream Flow Information Paper No...Thames. 1991. Hydrology and the management of watersheds . Iowa State University Press, Ames, IA. Brown, J. K . 1974. Handbook for inventorying downed...woody material. General Technical Report INT-16, U.S. Department of Agriculture, Forest Service. Brown, J. K ., R. D . Oberheu, and C. M. Johnston

Instream cover and shade mediate avian predation on trout in semi-natural streams

Treesearch

Brooke E. Penaluna; David L. G. Noakes

2015-01-01

Piscivory by birds can be important, particularly on fish in small streams and during seasonal low flows when available cover from predators can be limited. We conducted an experiment at the Oregon Hatchery Research Center to evaluate size-selective survival of Coastal Cutthroat Trout (Figure 8; Oncorhynchus clarkii clarkii) in replicated semi-...

Evaluation of Streamflow, Water Quality, and Permitted and Nonpermitted Loads and Yields in the Raritan River Basin, New Jersey, Water Years 1991-98

USGS Publications Warehouse

Reiser, Robert G.

2003-01-01

Seventeen water-quality constituents were analyzed in samples collected from 21 surface-water sampling sites in the Raritan River Basin during water years 1991-97. Loads were computed for seven constituents. Thirteen constituents have associated instream water-quality standards that are used as reference levels when evaluating the data. Nine of the 13 constituents did not meet water-quality reference levels in all samples at all sites. The constituents that most commonly failed to meet the water-quality reference levels in the 801 samples analyzed were total phosphorus (greater than 0.1 mg/L (milligrams per liter) in 32 percent of samples), fecal coliform bacteria (greater than 400 counts/100 milliliters in 29 percent), hardness (less than 50 mg/L in 21 percent), pH (greater than 8.5 or less than 6.5 in 17 percent), and water temperature in designated trout waters (greater than 20 degrees Celsius in 12 percent of samples). Concentrations of chloride, total dissolved solids, nitrate plus nitrite, and sulfate did not exceed water-quality reference levels in any sample. Results from previous studies on pesticides and volatile organic compounds in streamwater during 1996-98, and organic compounds and trace elements in sediments during 1976-93, were summarized for this study. Concentrations of pesticides in some samples exceeded the relevant standards. Water-quality data varied significantly as season and streamflow changed. Concentrations or values of 12 constituents were significantly higher in the growing season than in the nongrowing season at 1 to 21 sites, and concentrations of 6 constituents were significantly higher in the nongrowing season at 1 to 21 sites. Concentrations or values of seven constituents decreased significantly with increased streamflow, indicating a more significant contribution from base flow or permitted sources than from runoff. Concentrations or values of four constituents increased with increased flow, indicating a more significant contribution from runoff than from base flow or permitted sources. Phosphorus concentrations increased with flow at two sites with no point sources and decreased with flow at five sites with four or more permitted point sources. Concentrations of five constituents did not vary significantly with changes in streamflow at any of the sites. Concentrations of constituents differed significantly between sites. The sites with the most desirable values for the most constituents were Mulhockaway Creek, Spruce Run, Millstone River at Manalapan, Manalapan Brook, and Lamington River at Pottersville. The sites with the least desirable values for the most constituents were Millstone River at Blackwells Mills, Matchaponix Brook, Raritan River at Bound Brook, Neshanic River, and Millstone River at Grovers Mill. The total instream loads of seven constituents - total ammonia plus organic nitrogen (TKN), biochemical oxygen demand (BOD), total dissolved solids (TDS), nitrate plus nitrite (NO3+NO2), total organic carbon (TOC), total phosphorus, and total suspended solids (TSS) - were analyzed at low, median, and high flows. The quantities of total instream load that originated from facilities with permits issued by the New Jersey Department of Environmental Protection to discharge effluent to streams (permitted sources) and from other sources (nonpermitted sources) were estimated for each sampling site. TOC and TSS loads primarily were contributed by nonpermitted sources at all flows. BOD and TDS loads primarily were contributed by nonpermitted sources at median and high flows. At low flow, permitted sources contributed more than one-third of the TDS load at 10 sites and more than one-third of the BOD load at 3 sites. Permitted sources contributed more than one-third of the total phosphorus load at 15 and 14 sites at low and median flows, respectively. Permitted sources accounted for more than one-third of total instream load of NO3+NO2 at low- and median-flow conditions at nearly

Estimated water use in Montana in 2000

USGS Publications Warehouse

Cannon, M.R.; Johnson, Dave R.

2004-01-01

The future health and economic welfare of Montana's population is dependent on a continuing supply of fresh water. Montana's finite water resources are being stressed by increasing water withdrawals and instream-flow requirements. Various water managers in Montana need comprehensive, current, and detailed water-use data to quantify current stresses and estimate and plan for future water needs. This report summarizes selected water-use data for all of Montana's counties and stream basins to help meet those needs. In 2000, the citizens of Montana withdrew and used about 10,749 million gallons per day (Mgal/d) of water from Montana's streams and aquifers. Withdrawals from surface water were about 10,477 Mgal/d and withdrawals from ground water were about 272 Mgal/d. Agricultural irrigation accounted for about 10,378 Mgal/d or about 96.5 percent of total withdrawals for all uses. Withdrawals for public supply were about 136 Mgal/d, self-supplied domestic withdrawals were about 23 Mgal/d, self-supplied industrial withdrawals were about 61 Mgal/d, withdrawals for thermoelectric power generation were about 110 Mgal/d, and withdrawals for livestock were about 41 Mgal/d. Total consumptive use of water in 2000 was about 2,370 Mgal/d, of which about 2,220 Mgal/d (93.6 percent) was for agricultural irrigation. Instream uses of water included hydroelectric power generation and maintenance of instream flows for conservation of wildlife and aquatic life, and for public recreational purposes. In 2000, about 74,486 Mgal/d was used at hydroelectric plants for generation of about 11,591 gigawatt-hours of electricity. Evaporation from large water bodies, although not a classified water use, accounts for a large loss of water in some parts of the State. Net evaporation from Montana's 60 largest reservoirs and regulated lakes averaged about 891 Mgal/d.

The influence of distinct types of aquatic vegetation on the flow field

NASA Astrophysics Data System (ADS)

Valyrakis, Manousos; Barcroft, Stephen; Yagci, Oral

2014-05-01

The Sustainable management of fluvial systems dealing with flood prevention, erosion protection and restoration of rivers and estuaries requires implementation of soft/green-engineering methods. In-stream aquatic vegetation can be regarded as one of these as it plays an important role for both river ecology (function) and geomorphology (form). The goal of this research is to offer insight gained from pilot experimental studies on the effects of a number of different elements modeling instream, aquatic vegetation on the local flow field. It is hypothesized that elements of the same effective "blockage" area but of distinct characteristics (structure, porosity and flexibility), will affect both the mean and fluctuating levels of the turbulent flow to a different degree. The above hypothesis is investigated through a set of rigorous set of experimental runs which are appropriately designed to assess the variability between the interaction of aquatic elements and flow, both quantitatively and qualitatively. In this investigation three elements are employed to model aquatic vegetation, namely a rigid cylinder, a porous but rigid structure and a flexible live plant (Cupressus Macrocarpa). Firstly, the flow field downstream each of the mentioned elements was measured under steady uniform flow conditions employing acoustic Doppler velocimetry. Three-dimensional flow velocities downstream the vegetation element are acquired along a measurement grid extending about five-fold the element's diameter. These measurements are analyzed to develop mean velocity and turbulent intensity profiles for all velocity components. A detailed comparison between the obtained results is demonstrative of the validity of the above hypothesis as each of the employed elements affects in a different manner and degree the flow field. Then a flow visualization technique, during which fluorescent dye is injected upstream of the element and images are captured for further analysis and comparison, was employed to visualize the flow structures shed downstream the aquatic elements. This method allows to further observe qualitatively and visually identify the different characteristics of the eddies advected downstream, conclusively confirming the results of the aforementioned experimental campaign.

Estimated water use in Puerto Rico, 2000

USGS Publications Warehouse

Molina-Rivera, Wanda L.

2005-01-01

Water-use data were compiled for the 78 municipios of the Commonwealth of Puerto Rico for 2000. Five offstream categories were considered: public-supply water withdrawals, domestic self-supplied water use, industrial self-supplied withdrawals, crop irrigation water use, and thermoelectric power fresh water use. Two additional categories also were considered: power generation instream use and public wastewater treatment return-flows. Fresh water withdrawals for offstream use from surface- and ground-water sources in Puerto Rico were estimated at 617 million gallons per day. The largest amount of fresh water withdrawn was by public-supply water facilities and was estimated at 540 million gallons per day. Fresh surface- and ground-water withdrawals by domestic self-supplied users was estimated at 2 million gallons per day and the industrial self-supplied withdrawals were estimated at 9.5 million gallons per day. Withdrawals for crop irrigation purposes were estimated at 64 million gallons per day, or approximately 10 percent of all offstream fresh water withdrawals. Saline instream surface-water withdrawals for cooling purposes by thermoelectric power facilities was estimated at 2,191 million gallons per day, and instream fresh water withdrawals by hydroelectric facilities at 171 million gallons per day. Total discharge from public wastewater treatment facilities was estimated at 211 million gallons per day.

In-stream biogeochemical processes of a temporary river.

PubMed

Tzoraki, Ourania; Nikolaidis, Nikolaos P; Amaxidis, Yorgos; Skoulikidis, Nikolaos Th

2007-02-15

A reach at the estuary of Krathis River in Greece was used to assess how in-stream processes alter its hydrologic and biogeochemical regime. Krathis River exhibited high annual flow variability and its transmission losses become significant, especially during the dry months. These transmission losses are enhanced in chemistry due to release of nutrients from river sediments. These fluxes are significant because they correspond to 11% of the dissolved inorganic nitrogen flux of the river. Release of nitrogen species was influenced by temperature, while release of phosphate was not because phosphate levels were below the equilibrium concentration. There is a significant amount of sediments with fine composition that create "hot spot" areas in the river reach. These sediments are mobilized during the first flush events in the fall carrying with them a significant load of nutrient and suspended matter to the coastal zone. The nutrient organic content of sediments was also significant and it was studied in terms of its mineralization capacity. The capacity for mineralization was influenced by soil moisture, exhibiting significant capacity even at moisture levels of 40%. Temporary rivers are sensitive ecosystems, vulnerable to climate changes. In-stream processes play a significant role in altering the hydrology and biogeochemistry of the water and its impacts to the coastal zone.

Surface water-ground water interactions along the lower Dungeness River and vertical hydraulic conductivity of streambed sediments, Clallam County, Washington, September 1999-July 2001

USGS Publications Warehouse

Simonds, F. William; Sinclair, Kirk A.

2002-01-01

The Dungeness River emerges from the Olympic Mountains and flows generally north toward the Strait of Juan De Fuca, crossing the broad, fertile alluvial fan of the Sequim-Dungeness peninsula in northeastern Clallam County, Washington. Increasing competition for the peninsula's ground-water resources, changing water-use patterns, and recent requirements to maintain minimum in-stream flows to enhance endangered salmon and trout populations have severely strained the peninsula's water resources and necessitated a better understanding of the interaction between surface water and groundwater. Three methods were used to characterize the interchange between surface water and groundwater along the lower 11.8 miles of the Dungeness River corridor between September 1999 and July 2001. In-stream mini-piezometers were used to measure vertical hydraulic gradients between the river and the water-table aquifer at 27 points along the river and helped to define the distribution of gaining and losing stream reaches. Seepage runs were used to quantify the net volume of water exchanged between the river and ground water within each of five river reaches, termed 'seepage reaches.' Continuous water-level and water-temperature monitoring at two off-stream well transects provided data on near-river horizontal hydraulic gradients and temporal patterns of water exchange for a representative gaining stream reach and a representative losing stream reach. Vertical hydraulic gradients in the mini-piezometers generally were negative between river miles 11.8 and 3.6, indicating loss of water from the river to ground water. Gradients decreased in the downstream direction from an average of -0.86 at river mile 10.3 to -0.23 at river mile 3.7. Small positive gradients (+0.01 to +0.02) indicating ground-water discharge occurred in three localized reaches below river mile 3.7. Data from the seepage runs and off-stream transect wells supported and were generally consistent with the mini-piezometer findings. An exception occurred between river miles 8.1 and 5.5 where seepage results showed a small gain and the mini-piezometers showed negative gradients. Vertical hydraulic conductivity of riverbed sediments was estimated using hydraulic gradients measured with the mini-piezometers and estimated seepage fluxes. The resulting conductivity values ranged from an average of 1 to 29 feet per day and are similar to values reported for similar river environments elsewhere. The results of this study will be used to calibrate a transient, three-dimensional ground-water flow model of the Sequim-Dungeness peninsula. The model will be used to assess the potential effects on ground-water levels and river flows that result from future water use and land-use changes on the peninsula.

Modeling the Effects of Land Use and Climate Change on Streamflow in the Delaware River Basin

NASA Astrophysics Data System (ADS)

Kwon, P. Y. S.; Endreny, T. A.; Kroll, C. N.; Williamson, T. N.

2014-12-01

Forest-cover loss and drinking-water reservoirs in the upper Delaware River Basin of New York may alter summer low streamflows, which could degrade the in-stream habitat for the endangered dwarf wedgemussel. Our project analyzes how flow statistics change with land-cover change for 30-year increments of model-simulated streamflow hydrographs for three watersheds of concern to the National Park Service: the East Branch, West Branch, and main stem of the Delaware River. We use four treatments for land cover ranging from historical high to low forest cover. We subject each land cover to adjusted GCM climate scenarios for 1600, 1900, 1940, and 2040 to isolate land cover from potential climate-change effects. Hydrographs are simulated using the Water Availability Tool for Environmental Resources (WATER), a TOPMODEL-based United States Geological Survey hydrologic decision-support tool, which uses the variable-source-area concept and water budgets to generate streamflow. Model parameters for each watershed change with land-use, and capture differences in soil-physical properties that control how rainfall infiltrates, evaporates, transpires, is stored in the soil, and moves to the stream. Our results analyze flow statistics used as indicators of hydrologic alteration, and access streamflow events below the critical flow needed to provide sustainable habitat for dwarf wedgemussels. These metrics will demonstrate how changes in climate and land use might affect flow statistics. Initial results show that the 1940 WATER simulation outputs generally match observed unregulated low flows from that time period, while performance for regulated flow from the same time period and from 1600, 1900, and 2040 require model input adjustments. Our study will illustrate how increased forest cover could potentially restore in-stream habitat for the endangered dwarf wedgemussel for current and future climate conditions.

Detailed predictions of climate induced changes in the thermal and flow regimes in mountain streams of the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Santiago, José M.; Muñoz-Mas, Rafael; García de Jalón, Diego; Solana, Joaquín; Alonso, Carlos; Martínez-Capel, Francisco; Ribalaygua, Jaime; Pórtoles, Javier; Monjo, Robert

2016-04-01

Streamflow and temperature regimes are well-known to influence on the availability of suitable physical habitat for instream biological communities. General Circulation Models (GCMs) have predicted significant changes in timing and geographic distribution of precipitation and atmospheric temperature for the ongoing century. However, differences in these predictions may arise when focusing on different spatial and temporal scales. Therefore, to perform substantiated mitigation and management actions detailed scales are necessary to adequately forecast the consequent thermal and flow regimes. Regional predictions are relatively abundant but detailed ones, both spatially and temporally, are still scarce. The present study aimed at predicting the effects of climate change on the thermal and flow regime in the Iberian Peninsula, refining the resolution of previous studies. For this purpose, the study encompassed 28 sites at eight different mountain rivers and streams in the central part of the Iberian Peninsula (Spain). The daily flow was modelled using different daily, monthly and quarterly lags of the historical precipitation and temperature time series. These precipitation-runoff models were developed by means of M5 model trees. On the other hand water temperature was modelled at similar time scale by means of nonlinear regression from dedicated site-specific data. The developed models were used to simulate the temperature and flow regime under two Representative Concentration Pathway (RCPs) climate change scenarios (RCP 4.5 and RCP 8.5) until the end of the present century by considering nine different GCMs, which were pertinently downscaled. The precipitation-runoff models achieved high accuracy (NSE>0.7), especially in regards of the low flows of the historical series. Results concomitantly forecasted flow reductions between 7 and 17 % (RCP4.5) and between 8 and 49% (RCP8.5) of the annual average in the most cases, being variable the magnitude and timing at each site. The largest predicted changes will occur in summer and the complete depletion of some river segments was forecasted. Winter was the only season predicted flows to remain mostly unaffected by climate change. Mean annual stream temperature was predicted to experience heavy increases, especially during the second half of the century, varying from 0.3 to 1.6°C (RCP4.5), and 0.8 to 4.0°C (RCP8.5). Annual maximum and minimum average temperature increases were predicted to be between 0.1 and 1.5°C (RCP4.5) and between 0.2 and 3.0°C (RCP8.5), and between 0.4 and 1.8°C (RCP4.5) and between 1.1 and 4.5°C (RCP8.5), respectively. The most important increases were predicted to occur in summer while winter will experience the lesser ones. Geology attributable differences on thermal regime were observed between rivers. These results suggested the exacerbation of the principal characteristics of the Mediterranean climate-induced flow regimes with increased summer water temperatures and reduced low flows. Consequently, the synergistic effects of these climate induced changes may significantly impacts instream communities. Predictions of this study will be useful for designing habitat managing strategies for climate change adaptation at the local level. The revealed particularities reinforce the convenience of refining local predictions to design effective management policies.

A multi-scale GIS and hydrodynamic modelling approach to fish passage assessment: Clarence and Shoalhaven Rivers, NSW Australia

NASA Astrophysics Data System (ADS)

Bonetti, Rita M.; Reinfelds, Ivars V.; Butler, Gavin L.; Walsh, Chris T.; Broderick, Tony J.; Chisholm, Laurie A.

2016-05-01

Natural barriers such as waterfalls, cascades, rapids and riffles limit the dispersal and in-stream range of migratory fish, yet little is known of the interplay between these gradient dependent landforms, their hydraulic characteristics and flow rates that facilitate fish passage. The resurgence of dam construction in numerous river basins world-wide provides impetus to the development of robust techniques for assessment of the effects of downstream flow regime changes on natural fish passage barriers and associated consequences as to the length of rivers available to migratory species. This paper outlines a multi-scale technique for quantifying the relative magnitude of natural fish passage barriers in river systems and flow rates that facilitate passage by fish. First, a GIS-based approach is used to quantify channel gradients for the length of river or reach under investigation from a high resolution DEM, setting the magnitude of identified passage barriers in a longer context (tens to hundreds of km). Second, LiDAR, topographic and bathymetric survey-based hydrodynamic modelling is used to assess flow rates that can be regarded as facilitating passage across specific barriers identified by the river to reach scale gradient analysis. Examples of multi-scale approaches to fish passage assessment for flood-flow and low-flow passage issues are provided from the Clarence and Shoalhaven Rivers, NSW, Australia. In these river systems, passive acoustic telemetry data on actual movements and migrations by Australian bass (Macquaria novemaculeata) provide a means of validating modelled assessments of flow rates associated with successful fish passage across natural barriers. Analysis of actual fish movements across passage barriers in these river systems indicates that two dimensional hydraulic modelling can usefully quantify flow rates associated with the facilitation of fish passage across natural barriers by a majority of individual fishes for use in management decisions regarding environmental or instream flows.

Hydraulic complexity metrics for evaluating in-stream brook trout habitat

Treesearch

J. Kozarek; W. Hession; M. ASCE; C. Dolloff; P. Diplas

2010-01-01

A two-dimensional hydraulic model (River2D) was used to investigate the significance of flow complexity on habitat preferences of brook trout (Salvelinus fontinalis) in the high-gradient Staunton River in Shenandoah National Park, Virginia. Two 100-m reaches were modeled where detailed brook trout surveys (10–30-m resolution) have been conducted annually since 1997....

Instream cover and shade mediate avian predation on trout in semi-natural streams

Treesearch

Brooke E. Penaluna; Jason B. Dunham; David L. G. Noakes

2015-01-01

Piscivory by birds can be significant, particularly on fish in small streams and during seasonal low flow when available cover from predators can be limited. Yet, how varying amounts of cover may change the extent of predation mortality from avian predators on fish is not clear. We evaluated size-selective survival of coastal cutthroat trout (Oncorhynchus...

The effect of chamber mixing velocity on bias in measurement of sediment oxygen demand rates in the Tualatin River basin, Oregon

USGS Publications Warehouse

Doyle, Micelis C.; Rounds, Stewart

2003-01-01

The same resuspension effect probably exists in the Tualatin River during storm-runoff events following prolonged periods of low flow, when increased stream velocity may result in the resuspension of bottom sediments. The resuspension causes increased turbidity and increased oxygen demand, resulting in lower instream dissolved oxygen concentrations.

Summary of technical testimony in the Colorado Water Division 1 Trial

Treesearch

Nancy (Tech. Coord.) Gordon

1995-01-01

The Colorado Water Division 1 Water Rights Trial was one of the most significant federal reserved instream flow water rights cases to occur since the Supreme Court of the United States ruled in the case of United States v. New Mexico in 1978. This document summarize the large amount of technical data and information pertaining to the disciplines of geomorphology,...

Soil Microbial Community Contribution to Small Headwater Stream Metabolism.

NASA Astrophysics Data System (ADS)

Clapcott, J. E.; Gooderham, J. P.; Barmuta, L. A.; Davies, P. E.

2005-05-01

The temporal dynamics of sediment respiration were examined in seven small headwater streams in forested catchments in 2004. A strong seasonal response was observed with higher respiration rates in depositional zones than in gravel runs. The data were also examined in the context of proportional habitat distributions that highlighted the importance of high flow events in shaping whole stream metabolic budgets. This study specifically examines the question of terrestrial soil respiration contribution to whole stream metabolism by the controlled inundation of terrestrial soils. The experiment included six experimentally inundated terrestrial zones, six terrestrial controls, and six in-stream depositional zones. Sediment bacterial respiration was measured using 14C leucine incorporation and cotton strip bioassays were also employed to provide an indicative measure of sediment microbial activity. Despite high variability and exhibiting significantly lower bacterial activity than in-stream sediments, modelling using flow data and habitat mapping illustrated the important contribution of terrestrial soil respiration to the whole stream metabolic budgets of small headwater streams. In addition, microbial community composition examined using phospholipid fatty acid analysis clearly differentiated between terrestrial and aquatic communities. Freshly inundated terrestrial communities remained similar to un-inundated controls after 28 days.

Estimated use of water in the New England States, 1990

USGS Publications Warehouse

Korzendorfer, B.A.; Horn, M.A.

1995-01-01

Data on freshwater withdrawals in 1990 were compiled for the New England States. An estimated 4,160 Mgal/d (million gallons per day) of freshwater was withdrawn in 1990 in the six States. Of this total, 1,430 Mgal/d was withdrawn by public suppliers and delivered to users, and 2,720 Mgal/d was withdrawn by domestic, commercial, industrial, agricultural, mining, and thermoelectric power-generation users. More than 83 percent of the freshwater was from surface-water sources. Massachusetts, with the largest population, had the largest withdrawals of water. Data on saline water withdraw, and instream flow at hydroelectric plants were also compiled. An estimated 9, 170 Mgal/d of saline water was used for thermoelectric-power generation and industrial use in Connecticut, Maine, Massachusetts, New Hampshire, and Rhode Island. Return flow fro public wastewater-treatment plants totaled 1,750 Mgal/d; more than half (55 percent) of this return flow was in Massachusetts. In addition, about 178,000 Mgal/d was used for instream hydroelectric power generation; the largest users were Maine (about 83,000 Mgal/d) and New Hampshire (46,000 Mgal/d). These data, some of which were based on site-specific water-use information and some based on estimation techniques, were compiled through joint efforts by the U.S. Geological Survey and State cooperators for the 1990 national water-use compilation.

Proceedings of a workshop on the development and evaluation of habitat suitability criteria: A compilation of papers and discussions presented at Colorado State University, Fort Collins, Colorado, December 8-12, 1986

USGS Publications Warehouse

Bovee, Ken; Zuboy, J.R.

1988-01-01

The development of reliable habitat suitability criteria is critical to the successful implementation of the Instream Flow Incremental Methodology (IFIM), or any other habitat based evaluation technology. It is also a fascinating topic of research, for several reasons. First, the “science” of habitat quantification is relatively young. Descriptions of habitat use and partitioning can be traced back to Darwin, if not further. Attempts to actually quantify habitat use can be found predominantly during the last two decades, with most of the activity occurring in about the last five years. Second, this work is challenging because we are usually working with fish or some other organism that lives out of sight in an environment that is foreign to humans. Most of the data collection techniques that have been developed for standard fisheries work are unsuited, without modification, for criteria development. These factors make anyone involved in this type of research a pioneer, of sorts. Pioneers often make new and wonderful discoveries, but they also sometimes get lost. In our opinion, however, there is an even more rewarding aspect to criteria development research. It seems that the field of biology has tended to become increasingly clinical over the years. Criteria development demands the unobtrusive observation of organisms in their natural environment, a fact that allows the biological to be a naturalist and still get paid for it. The relative youth and importance of habitat quantification have resulted in rapid advancements in the state of the art. The expansion of methods is vividly demonstrated simply by comparing the two Instream Flow Information Papers written on the subject in 1978 and in 1986. One of the missions of the Aquatic Systems Branch (formerly the Instream Flow Group) is to serve as a clearinghouse for new techniques and methods. In keeping with this role, a workshop was conducted during December 1986 to discuss current and newly evolving methods for developing and evaluating habitat suitability criteria. Participation in this workshop was largely by invitation only. The objective was to obtain insights into problems and possible solutions to criteria development, from the perspective of professionals closely involved with the subject. These proceedings of that workshop are intended to supplement the information contained in Instream Flow Information Paper 21, "Development and Evaluation of Habitat Suitability Criteria for Use in the Instream Flow Incremental Methodology." The workshop was closely arranged in five sessions, roughly following the outline of Information Paper 21. The first session dealt with various aspects of study design and how they can influence the outcome of a study. Session two investigated techniques for developing criteria from professional judgment, and some of the problems encountered when personal or agency prejudice enters the picture. Session three concentrated on field data collection procedures, whereas session four examined methods of converting field data into curves. Field verification studies were discussed in session five. Each presentation in the workshop was followed by a question and answer period of 15 to 30 minutes. These discussions were recorded, transcribed, and appended to the end of each paper in these proceedings. We have attempted to capture the essence of these discussions as accurately as possible, but hope that the reader can appreciate the difficulty in translating a free-ranging discussion (from a barely audible tape) to something that makes sense in print. These question and answer sessions constitute the peer review for each of the papers. This provides the reader with the unique opportunity to review the interactions between authors and reviewers.

Hydrodynamic effects of kinetic power extraction by in-stream tidal turbines

NASA Astrophysics Data System (ADS)

Polagye, Brian L.

The hydrodynamic effects of extracting kinetic power from tidal streams presents unique challenges to the development of in-stream tidal power. In-stream tidal turbines superficially resemble wind turbines and extract kinetic power from the ebb and flood of strong tidal currents. Extraction increases the resistance to flow, leading to changes in tidal range, transport, mixing, and the kinetic resource itself. These far-field changes have environmental, social, and economic implications that must be understood to develop the in-stream resource. This dissertation describes the development of a one-dimensional numerical channel model and its application to the study of these effects. The model is applied to determine the roles played by site geometry, network topology, tidal regime, and device dynamics. A comparison is also made between theoretical and modeled predictions for the maximum amount of power which could be extracted from a tidal energy site. The model is extended to a simulation of kinetic power extraction from Puget Sound, Washington. In general, extracting tidal energy will have a number of far-field effects, in proportion to the level of power extraction. At the theoretical limit, these effects can be very significant (e.g., 50% reduction in transport), but are predicted to be immeasurably small for pilot-scale projects. Depending on the specifics of the site, far-field effects may either augment or reduce the existing tidal regime. Changes to the tide, in particular, have significant spatial variability. Since tidal streams are generally subcritical, effects are felt throughout the estuary, not just at the site of extraction. The one dimensional numerical modeling is supported by a robust theory for predicting the performance characteristics of in-stream devices. The far-field effects of tidal power depend on the total power dissipated by turbines, rather than the power extracted. When the low-speed wake downstream of a turbine mixes with the free-stream, power is lost, such that the total power dissipated by the turbine is significantly greater than the power extracted. This dissertation concludes with a framework for three-dimensional numerical modeling of near-field extraction effects.

Impact of transient stream flow on water exchange and reactions in the hyporheic zone of an in-stream gravel bar

NASA Astrophysics Data System (ADS)

Trauth, Nico; Schmidt, Christian; Fleckenstein, Jan H.

2015-04-01

Groundwater-surface water exchange is an important process that can facilitate the degradation of critical substances like nitrogen-species and contaminants, supporting a healthy status of the aquatic ecosystem. In our study, we simulate water exchange, solute transport and reactions within a natural in-stream gravel bar using a coupled surface and subsurface numerical model. Stream water flow is simulated by computational fluid dynamics software that provides hydraulic head distributions at the streambed, which are used as an upper boundary condition for a groundwater model. In the groundwater model water exchange, solute transport, aerobic respiration and denitrification in the subsurface are simulated. Ambient groundwater flow is introduced by lateral upstream and downstream hydraulic head boundaries that generate neutral, losing or gaining stream conditions. Stream water transports dissolved oxygen, organic carbon (as the dominant electron donor) and nitrate into the subsurface, whereas an additional nitrate source exists in the ambient groundwater. Scenarios of stream flow events varying in duration and stream stage are simulated and compared with steady state scenarios with respect to water fluxes, residence times and the solute turn-over rates. Results show, that water exchange and solute turn-over rates highly depend on the interplay between event characteristics and ambient groundwater levels. For scenarios, where the stream flow event shifts the hydraulic system to a net-neutral hydraulic gradient between the average stream stage and the ambient groundwater level (minimal exchange between ground- and surface water), solute consumption is higher, compared to the steady losing or gaining case. In contrast, events that induce strong losing conditions lead to a lower potential of solute consumption.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for Sand Creek, Decatur County, Indiana

USGS Publications Warehouse

Wilber, William G.; Crawford, Charles G.; Peters, James G.

1979-01-01

A digital model calibrated to conditions in Sand Creek near Greensburg, Ind., was used to develop alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. The only point-source waste load affecting Sand Creek in the vicinity of Greensburg is the Greensburg wastewater-treatment facility. Non-point, unrecorded waste loads seemed to be significant during three water-quality surveys done by the Indiana State Board of Health. Natural streamflow in Sand Creek during the summer and annual 7-day, 10-year low flow is zero so no benefit from dilution is provided. Effluent ammonia-nitrogen concentrations from the Greensburg wastewater-treatment facility will not meet Indiana water-quality standards during summer and winter low flows. To meet the water-quality standard the wastewater-effluent would be limited to a maximum total ammonia-nitrogen concentration of 2.5 mg/l for summer months (June through August) and 4.0 mg/l for winter months (November through March). Model simulations indicate that benthic-oxygen demand, nitrification, and the dissolved-oxygen concentration of the wastewater effluent are the most significant factors affecting the in-stream dissolved-oxygen concentration during summer low flows. The model predicts that with a benthic-oxygen demand of 1.5 grams per square meter per day at 20C the stream has no additional waste-load assimilative capacity. Present carbonaceous biochemical-oxygen demand loads from the Greensburg wastewater-treatment facility will not result in violations of the in-stream dissolved-oxygen standard (5 mg/l) during winter low flows. (Kosco-USGS)

Nitrogen attenuation in the Connecticut River, northeastern USA; a comparison of mass balance and N2 production modeling approaches

USGS Publications Warehouse

Smith, T.E.; Laursen, A.E.; Deacon, J.R.

2008-01-01

Two methods were used to measure in-stream nitrogen loss in the Connecticut River during studies conducted in April and August 2005. A mass balance on nitrogen inputs and output for two study reaches (55 and 66 km), at spring high flow and at summer low flow, was computed on the basis of total nitrogen concentrations and measured river discharges in the Connecticut River and its tributaries. In a 10.3 km subreach of the northern 66 km reach, concentrations of dissolved N2 were also measured during summer low flow and compared to modeled N2 concentrations (based on temperature and atmospheric gas exchange rates) to determine the measured "excess" N2 that indicates denitrification. Mass balance results showed no in-stream nitrogen loss in either reach during April 2005, and no nitrogen loss in the southern 55 km study reach during August 2005. In the northern 66 km reach during August 2005, however, nitrogen output was 18% less than the total nitrogen inputs to the reach. N2 sampling results gave an estimated rate of N2 production that would remove 3.3% of the nitrogen load in the river over the 10.3 km northern sub-reach. The nitrogen losses measured in the northern reach in August 2005 may represent an approximate upper limit for nitrogen attenuation in the Connecticut River because denitrification processes are most active during warm summer temperatures and because the study was performed during the annual low-flow period when total nitrogen loads are small. ?? 2008 Springer Science+Business Media B.V.

Hydrologic classification of rivers based on cluster analysis of dimensionless hydrologic signatures: Applications for environmental instream flows

NASA Astrophysics Data System (ADS)

Praskievicz, S. J.; Luo, C.

2017-12-01

Classification of rivers is useful for a variety of purposes, such as generating and testing hypotheses about watershed controls on hydrology, predicting hydrologic variables for ungaged rivers, and setting goals for river management. In this research, we present a bottom-up (based on machine learning) river classification designed to investigate the underlying physical processes governing rivers' hydrologic regimes. The classification was developed for the entire state of Alabama, based on 248 United States Geological Survey (USGS) stream gages that met criteria for length and completeness of records. Five dimensionless hydrologic signatures were derived for each gage: slope of the flow duration curve (indicator of flow variability), baseflow index (ratio of baseflow to average streamflow), rising limb density (number of rising limbs per unit time), runoff ratio (ratio of long-term average streamflow to long-term average precipitation), and streamflow elasticity (sensitivity of streamflow to precipitation). We used a Bayesian clustering algorithm to classify the gages, based on the five hydrologic signatures, into distinct hydrologic regimes. We then used classification and regression trees (CART) to predict each gaged river's membership in different hydrologic regimes based on climatic and watershed variables. Using existing geospatial data, we applied the CART analysis to classify ungaged streams in Alabama, with the National Hydrography Dataset Plus (NHDPlus) catchment (average area 3 km2) as the unit of classification. The results of the classification can be used for meeting management and conservation objectives in Alabama, such as developing statewide standards for environmental instream flows. Such hydrologic classification approaches are promising for contributing to process-based understanding of river systems.

Supplement Analysis for the Watershed Management Program EIS, (DOE/EIS-0265/SA-69) - Improvement of Anadromous Fish Habitat and Passage in Omak Creek

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

Spiering, Colleen

2001-11-15

BPA proposes to fund a project with the Colville Confederated Tribes that will improve spawning and rearing specifically for summer steelhead in the Omak Creek Watershed. Efforts to achieve this objective include improved livestock and forestry management and barrier removal. These techniques include exclusionary fencing, spring developments, hardened-rock crossings, road decommissioning, culvert removal and placement, riparian vegetation planting and installation of instream structures. The result of implementing these techniques will reduce fine sediment delivered to the stream channel which will result in increased hatching success of summer steelhead. Also, reestablishing riparian vegetation will provide canopy and enclose the stream channelmore » resulting in reduced stream temperatures. Two “on-the-ground” projects are proposed for this year. One project consists of installing three instream structures and planting riparian vegetation to provide bank stability along approximately 200’ of privately owned stream bank of Omak Creek. Also a fence will be constructed to exclude the landowner’s horses. The second project consists of removal of an inadequate sized culvert (5’ diameter) and replacement with a larger bottomless arch (6’ x 12’). This project will also include seven instream structures to stabilize the stream bank both upstream and downstream of the culvert and direct flows through the center of the bottomless arch.« less

Differences in instream wood characteristics between channelized and unchannelized agricultural headwater streams in central Ohio

USDA-ARS?s Scientific Manuscript database

Instream wood is an important resource for stream biota because it provides cover for fishes, substrate for macroinvertebrates, and increases habitat diversity. However, current management of instream wood within channelized agricultural headwater streams (drainage ditches) involves removing instrea...

Measuring real-time streamflow using emerging technologies: Radar, hydroacoustics, and the probability concept

NASA Astrophysics Data System (ADS)

Fulton, John; Ostrowski, Joseph

2008-07-01

SummaryForecasting streamflow during extreme hydrologic events such as floods can be problematic. This is particularly true when flow is unsteady, and river forecasts rely on models that require uniform-flow rating curves to route water from one forecast point to another. As a result, alternative methods for measuring streamflow are needed to properly route flood waves and account for inertial and pressure forces in natural channels dominated by nonuniform-flow conditions such as mild water surface slopes, backwater, tributary inflows, and reservoir operations. The objective of the demonstration was to use emerging technologies to measure instantaneous streamflow in open channels at two existing US Geological Survey streamflow-gaging stations in Pennsylvania. Surface-water and instream-point velocities were measured using hand-held radar and hydroacoustics. Streamflow was computed using the probability concept, which requires velocity data from a single vertical containing the maximum instream velocity. The percent difference in streamflow at the Susquehanna River at Bloomsburg, PA ranged from 0% to 8% with an average difference of 4% and standard deviation of 8.81 m 3/s. The percent difference in streamflow at Chartiers Creek at Carnegie, PA ranged from 0% to 11% with an average difference of 5% and standard deviation of 0.28 m 3/s. New generation equipment is being tested and developed to advance the use of radar-derived surface-water velocity and instantaneous streamflow to facilitate the collection and transmission of real-time streamflow that can be used to parameterize hydraulic routing models.

Measuring real-time streamflow using emerging technologies: Radar, hydroacoustics, and the probability concept

USGS Publications Warehouse

Fulton, J.; Ostrowski, J.

2008-01-01

Forecasting streamflow during extreme hydrologic events such as floods can be problematic. This is particularly true when flow is unsteady, and river forecasts rely on models that require uniform-flow rating curves to route water from one forecast point to another. As a result, alternative methods for measuring streamflow are needed to properly route flood waves and account for inertial and pressure forces in natural channels dominated by nonuniform-flow conditions such as mild water surface slopes, backwater, tributary inflows, and reservoir operations. The objective of the demonstration was to use emerging technologies to measure instantaneous streamflow in open channels at two existing US Geological Survey streamflow-gaging stations in Pennsylvania. Surface-water and instream-point velocities were measured using hand-held radar and hydroacoustics. Streamflow was computed using the probability concept, which requires velocity data from a single vertical containing the maximum instream velocity. The percent difference in streamflow at the Susquehanna River at Bloomsburg, PA ranged from 0% to 8% with an average difference of 4% and standard deviation of 8.81 m3/s. The percent difference in streamflow at Chartiers Creek at Carnegie, PA ranged from 0% to 11% with an average difference of 5% and standard deviation of 0.28 m3/s. New generation equipment is being tested and developed to advance the use of radar-derived surface-water velocity and instantaneous streamflow to facilitate the collection and transmission of real-time streamflow that can be used to parameterize hydraulic routing models.

Monitoring And Modeling Environmental Water Quality To Support Environmental Water Purchase Decision-making

NASA Astrophysics Data System (ADS)

Null, S. E.; Elmore, L.; Mouzon, N. R.; Wood, J. R.

2016-12-01

More than 25 million cubic meters (20,000 acre feet) of water has been purchased from willing agricultural sellers for environmental flows in Nevada's Walker River to improve riverine habitat and connectivity with downstream Walker Lake. Reduced instream flows limit native fish populations, like Lahontan cutthroat trout, through warm daily stream temperatures and low dissolved oxygen concentrations. Environmental water purchases maintain instream flows, although effects on water quality are more varied. We use multi-year water quality monitoring and physically-based hydrodynamic and water quality modeling to estimate streamflow, water temperature, and dissolved oxygen concentrations with alternative environmental water purchases. We simulate water temperature and dissolved oxygen changes from increased streamflow to prioritize the time periods and locations that environmental water purchases most enhance trout habitat as a function of water quality. Monitoring results indicate stream temperature and dissolved oxygen limitations generally exist in the 115 kilometers upstream of Walker Lake (about 37% of the study area) from approximately May through September, and this reach acts as a water quality barrier for fish passage. Model results indicate that low streamflows generally coincide with critically warm stream temperatures, water quality refugia exist on a tributary of the Walker River, and environmental water purchases may improve stream temperature and dissolved oxygen conditions for some reaches and seasons, especially in dry years and prolonged droughts. This research supports environmental water purchase decision-making and allows water purchase decisions to be prioritized with other river restoration alternatives.

Effectiveness of timber harvesting BMPs: monitoring spatial and temporal dynamics of dissolved oxygen, nitrogen, and phosphorus in a low-gradient watershed, Louisiana

Treesearch

Abram DaSilva; Y. Jun Xu; George Ice; John Beebe; Richard Stich

2012-01-01

To test effectiveness of Louisiana’s voluntary best management practices (BMPs) at preventing water quality degradation from timber harvesting activities, a study with BACI design was conducted from 2006 through 2010 in the Flat Creek Watershed, north-central Louisiana. Water samples for nutrient analyses and measurements of stream flow and of in-stream dissolved...

Alluvial Mountain Meadow Source-Sink Dynamics: Land-Cover Effects on Water and Fluvial Carbon Export

NASA Astrophysics Data System (ADS)

Weiss, T.; Covino, T. P.; Wohl, E.; Rhoades, C.; Fegel, T.; Clow, D. W.

2017-12-01

Fluvial networks of historically glaciated mountain landscapes alternate between confined and unconfined valley segments. In low-gradient unconfined reaches, river-connected wet meadows commonly establish, and have been recognized as important locations of long-term water, carbon, and nutrient storage. Among connected meadow floodplains, sink-source behavior shifts as a function of flow state; storing water at high flows (snowmelt) and contributing toward higher late-season baseflows. Despite these benefits, historical and contemporary land-use practices often result in the simplification of wet meadow systems, leading to reduced river-floodplain connectivity, lower water-tables and reductions in hydrologic buffering capacity. In this study, we are exploring hydrologic-carbon relationships across a gradient of valley confinement and river-floodplain connectivity (connected, n=3; disconnected, n=4) within the Colorado Rockies. Our approach includes hydrologic analysis, fluorometric assays, water chemistry, instream metabolic measures, and land-cover assessment to examine patterns between land-form, carbon quantity and quality, and stream ecosystem productivity. Between different meadow types, preliminary results suggest differences between instream productivity, carbon qualities, and hydrologic-carbon sink-source dynamics across the season. These data and analyses will provide insight into water, carbon and nutrient flux dynamics as a function of land-cover in mountain headwaters.

Ecological drought: Accounting for the non-human impacts of water shortage in the Upper Missouri Headwaters Basin, Montana, USA

USGS Publications Warehouse

McEvoy, Jamie; Bathke, Deborah J.; Burkardt, Nina; Cravens, Amanda; Haigh, Tonya; Hall, Kimberly R.; Hayes, Michael J.; Jedd, Theresa; Podebradska, Marketa; Wickham, Elliot

2018-01-01

Water laws and drought plans are used to prioritize and allocate scarce water resources. Both have historically been human-centric, failing to account for non-human water needs. In this paper, we examine the development of instream flow legislation and the evolution of drought planning to highlight the growing concern for the non-human impacts of water scarcity. Utilizing a new framework for ecological drought, we analyzed five watershed-scale drought plans in southwestern Montana, USA to understand if, and how, the ecological impacts of drought are currently being assessed. We found that while these plans do account for some ecological impacts, it is primarily through the narrow lens of impacts to fish as measured by water temperature and streamflow. The latter is typically based on the same ecological principles used to determine instream flow requirements. We also found that other resource plans in the same watersheds (e.g., Watershed Restoration Plans, Bureau of Land Management (BLM) Watershed Assessments or United States Forest Service (USFS) Forest Plans) identify a broader range of ecological drought risks. Given limited resources and the potential for mutual benefits and synergies, we suggest greater integration between various planning processes could result in a more holistic consideration of water needs and uses across the landscape.

Instream large wood: Denitrification hotspots with low N2O production

EPA Science Inventory

We examined the effect of instream large wood on denitrification capacity in two contrasting, lower order streams — one that drains an agricultural watershed with no riparian forest and minimal stores of instream large wood and another that drains a forested watershed with an ext...

Variation in flow and suspended sediment transport in a montane river affected by hydropeaking and instream mining

NASA Astrophysics Data System (ADS)

Béjar, M.; Vericat, D.; Batalla, R. J.; Gibbins, C. N.

2018-06-01

The temporal and spatial variability of water and sediment loads of rivers is controlled by a suite of factors whose individual effects are often difficult to disentangle. While land use changes and localised human activities such as instream mining and hydropeaking alter water and sediment transfer, tributaries naturally contribute to discharge and sediment load of mainstem rivers, and so may help compensate upstream anthropogenic factors. The work presented here aimed to assess water and the sediment transfer in a river reach affected by gravel extraction and hydropeaking, set against a backdrop of changes to the supply of water and sediment from tributaries. Discharge and suspended sediment transport were monitored during two average hydrological years at three cross-sections along a 10-km reach of the upper River Cinca, in the Southern Pyrenees. Water and sediment loads differed substantially between the reaches. The upper reach showed a largely torrential discharge regime, controlled mainly by floods, and had high but variable water and sediment loads. The middle reach was influenced markedly by hydropeaking and tributary inflows, which increased its annual water yield four-fold. Suspended sediment load in this reach increased by only 25% compared to upstream, indicating that dilution predominated. In the lowermost section, while discharge remained largely unaltered, sediment load increased appreciably as a result of changes to sediment availability from instream mining and inputs from tributaries. At the reach scale, snowmelt and summer and autumn thunderstorms were responsible for most of the water yield, while flood flows determined the magnitude and transport of the sediment load. The study highlights that a combination of natural and human factors control the spatial and temporal transfer of water and sediment in river channels and that, depending on their geographic location and effect-size, can result in marked variability even over short downstream distances.

Data to support statistical modeling of instream nutrient load based on watershed attributes, southeastern United States, 2002

USGS Publications Warehouse

Hoos, Anne B.; Terziotti, Silvia; McMahon, Gerard; Savvas, Katerina; Tighe, Kirsten C.; Alkons-Wolinsky, Ruth

2008-01-01

This report presents and describes the digital datasets that characterize nutrient source inputs, environmental characteristics, and instream nutrient loads for the purpose of calibrating and applying a nutrient water-quality model for the southeastern United States for 2002. The model area includes all of the river basins draining to the south Atlantic and the eastern Gulf of Mexico, as well as the Tennessee River basin (referred to collectively as the SAGT area). The water-quality model SPARROW (SPAtially-Referenced Regression On Watershed attributes), developed by the U.S. Geological Survey, uses a regression equation to describe the relation between watershed attributes (predictors) and measured instream loads (response). Watershed attributes that are considered to describe nutrient input conditions and are tested in the SPARROW model for the SAGT area as source variables include atmospheric deposition, fertilizer application to farmland, manure from livestock production, permitted wastewater discharge, and land cover. Watershed and channel attributes that are considered to affect rates of nutrient transport from land to water and are tested in the SAGT SPARROW model as nutrient-transport variables include characteristics of soil, landform, climate, reach time of travel, and reservoir hydraulic loading. Datasets with estimates of each of these attributes for each individual reach or catchment in the reach-catchment network are presented in this report, along with descriptions of methods used to produce them. Measurements of nutrient water quality at stream monitoring sites from a combination of monitoring programs were used to develop observations of the response variable - mean annual nitrogen or phosphorus load - in the SPARROW regression equation. Instream load of nitrogen and phosphorus was estimated using bias-corrected log-linear regression models using the program Fluxmaster, which provides temporally detrended estimates of long-term mean load well-suited for spatial comparisons. The detrended, or normalized, estimates of load are useful for regional-scale assessments but should be used with caution for local-scale interpretations, for which use of loads estimated for actual time periods and employing more detailed regression analysis is suggested. The mean value of the nitrogen yield estimates, normalized to 2002, for 637 stations in the SAGT area is 4.7 kilograms per hectare; the mean value of nitrogen flow-weighted mean concentration is 1.2 milligrams per liter. The mean value of the phosphorus yield estimates, normalized to 2002, for the 747 stations in the SAGT area is 0.66 kilogram per hectare; the mean value of phosphorus flow-weighted mean concentration is 0.17 milligram per liter. Nutrient conditions measured in streams affected by substantial influx or outflux of water and nutrient mass across surface-water basin divides do not reflect nutrient source and transport conditions in the topographic watershed; therefore, inclusion of such streams in the SPARROW modeling approach is considered inappropriate. River basins identified with this concern include south Florida (where surface-water flow paths have been extensively altered) and the Oklawaha, Crystal, Lower Sante Fe, Lower Suwanee, St. Marks, and Chipola River basins in central and northern Florida (where flow exchange with the underlying regional aquifer may represent substantial nitrogen influx to and outflux from the surface-water basins).

Catchment-wide impacts on water quality: the use of 'snapshot' sampling during stable flow

NASA Astrophysics Data System (ADS)

Grayson, R. B.; Gippel, C. J.; Finlayson, B. L.; Hart, B. T.

1997-12-01

Water quality is usually monitored on a regular basis at only a small number of locations in a catchment, generally focused at the catchment outlet. This integrates the effect of all the point and non-point source processes occurring throughout the catchment. However, effective catchment management requires data which identify major sources and processes. As part of a wider study aimed at providing technical information for the development of integrated catchment management plans for a 5000 km 2 catchment in south eastern Australia, a 'snapshot' of water quality was undertaken during stable summer flow conditions. These low flow conditions exist for long periods so water quality at these flow levels is an important constraint on the health of in-stream biological communities. Over a 4 day period, a study of the low flow water quality characteristics throughout the Latrobe River catchment was undertaken. Sixty-four sites were chosen to enable a longitudinal profile of water quality to be established. All tributary junctions and sites along major tributaries, as well as all major industrial inputs were included. Samples were analysed for a range of parameters including total suspended solids concentration, pH, dissolved oxygen, electrical conductivity, turbidity, flow rate and water temperature. Filtered and unfiltered samples were taken from 27 sites along the main stream and tributary confluences for analysis of total N, NH 4, oxidised N, total P and dissolved reactive P concentrations. The data are used to illustrate the utility of this sampling methodology for establishing specific sources and estimating non-point source loads of phosphorous, total suspended solids and total dissolved solids. The methodology enabled several new insights into system behaviour including quantification of unknown point discharges, identification of key in-stream sources of suspended material and the extent to which biological activity (phytoplankton growth) affects water quality. The costs and benefits of the sampling exercise are reviewed.

Modeling Applications to Inform Hydromodification Management Design Decisions

NASA Astrophysics Data System (ADS)

Goodman, J.

2013-12-01

Hydromodification is defined as changes in runoff characteristics and in-stream processes caused by altered land use. The impact of hydromodification can manifest itself through adjustment of stream morphology via channel incision, widening, planform alteration, or coarsening of the bed material. The state of the practice for hydromodification management in California and Western Washington for new and re-development has been to mimic pre-development site hydrology. The theory is that if the pre-development distribution of in-stream flows is maintained, then the baseline capacity to transport sediment, a proxy for the geomorphic condition, will be maintained as well. A popular method of mimicking the pre-development flow regime is by maintaining the pre-development frequency distribution of runoff, known as flow duration control. This can be done by routing post-development runoff through structural stormwater facilities (BMPs) such that runoff is stored and slowly released to match pre-development flow duration characteristics. As it turns out, storage requirements for hydromodification control tend to be much larger than that for surface water treatment requirements (see nomograph). As regulatory requirements for hydromodification evolve and begin to spread to other parts of the country, it is necessary that scientists, water resources professionals, and policy makers understand the practical challenges of implementing hydromodification controls, including the sizing and cost constraints, and know about innovations which could make hydromodification controls more feasible to implement. In an effort to provide the audience with this better understanding, this presentation will share a step-by-step approach for predicting long-term hydromodification impacts; demonstrate options for mitigating these impacts within the context of the modeling approach; and discuss sizing sensitivities of LID-type hydromodification control structural BMPs as a function of performance standard (Flow Duration Control vs. Erosion Potential), receiving stream susceptibility (critical low flow discharges for incipient motion of 5%Q2, 10%Q2, vs. 20%Q2), and outlet design (passive vs. active smart controls). nomograph

Modeling E. coli Release And Transport In A Creek During Artificial High-Flow Events

NASA Astrophysics Data System (ADS)

Yakirevich, A.; Pachepsky, Y. A.; Gish, T. J.; Cho, K.; Shelton, D. R.; Kuznetsov, M. Y.

2012-12-01

In-stream fate and transport of E. coli, is a leading indicator of microbial contamination of natural waters, and so needs to be understood to eventually minimize surface water contamination by microbial organisms. The objective of this work was to simulate E. coli release and transport from soil sediment in a creek bed both during and after high water flow events. The artificial high-water flow events were created by releasing 60-80 m3 of city water on a tarp-covered stream bank at a rate of 60 L/s in four equal allotments in July of 2008, 2009 and 2010. The small first-order creek used in this study is part of the Beaver Dam Creek Tributary and is located at the USDA Optimizing Production inputs for Economic and Environmental Enhancement (OPE3) research site, in Beltsville, Maryland. In 2009 and 2010 a conservative tracer difluorobenzoic acid (DFBA) was added to the released water. Specifically, water flow rates, E. coli and DFBA concentrations as well as water turbidity were monitored with automated samplers at the ends of the three in-stream weirs reaching a total length of 630 m. Sediment particle size distributions and the streambed E. coli concentrations were measured along a creek before and after experiment. The observed DFBA breakthrough curves (BTCs) exhibited long tails after the water pulse and tracer peaks indicating that transient storage might be an important element of the in-stream transport process. Turbidity and E. coli BTCs also exhibited long tails indicative of transient storage and low rates of settling caused by re-entrainment. Typically, turbidity peaked prior to E. coli and returned to lower base-line levels more rapidly. A one-dimensional model was applied to simulate water flow, E. coli and DFBA transport during these experiments. The Saint-Venant equations were used to calculate water depth and discharge while a stream solute transport model accounted for advection-dispersion, lateral inflow/outflow, exchange with the transient storage, and resuspension of bacteria by shear stress from stream bottom sediments. Reach-specific model parameters were estimated by using observed time series of flow rates and concentrations at three weir stations. Transient storage and dispersion parameters were obtained with DFBA BTCs, then critical shear stress and resuspension rate were assessed by fitting computed E. coli BTCs to observations. To obtain a good model fit for E. coli, we generally had to make the transient storage for E. coli larger than for DFBA. Comparison of simulated and measured E. coli concentrations indicated that significant resuspension of E. coli continued when water flow returned to the base level after the water pulse passed and bottom shear stress was small. The hypothetical mechanism of this extended release could be the enhanced boundary layer (water-streambed) exchange due to changes in biofilm properties by erosion and sloughing detachment.

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Northwest) Pink Salmon

DTIC Science & Technology

1989-01-01

methodology weight in the sockeye salmon for determining instream flow re- ( Oncorhynchus nerka ) and the pink quirements for fish. Pages 72-86 in salmon (0...Scientific name ........... Oncorhynchus jor pink salmon runs. Migration gorbuscha (Walbaum) (Figure a patterns of fish entering British Preferred...A dominant male guards the considered the most specialized of the female during the digging process, salmon in the genus Oncorhynchus be- attacking

Groundwater and surface-water interaction, water quality, and processes affecting loads of dissolved solids, selenium, and uranium in Fountain Creek near Pueblo, Colorado, 2012–2014

USGS Publications Warehouse

Arnold, L. Rick; Ortiz, Roderick F.; Brown, Christopher R.; Watts, Kenneth R.

2016-11-28

In 2012, the U.S. Geological Survey, in cooperation with the Arkansas River Basin Regional Resource Planning Group, initiated a study of groundwater and surface-water interaction, water quality, and loading of dissolved solids, selenium, and uranium to Fountain Creek near Pueblo, Colorado, to improve understanding of sources and processes affecting loading of these constituents to streams in the Arkansas River Basin. Fourteen monitoring wells were installed in a series of three transects across Fountain Creek near Pueblo, and temporary streamgages were established at each transect to facilitate data collection for the study. Groundwater and surface-water interaction was characterized by using hydrogeologic mapping, groundwater and stream-surface levels, groundwater and stream temperatures, vertical hydraulic-head gradients and ratios of oxygen and hydrogen isotopes in the hyporheic zone, and streamflow mass-balance measurements. Water quality was characterized by collecting periodic samples from groundwater, surface water, and the hyporheic zone for analysis of dissolved solids, selenium, uranium, and other selected constituents and by evaluating the oxidation-reduction condition for each groundwater sample under different hydrologic conditions throughout the study period. Groundwater loads to Fountain Creek and in-stream loads were computed for the study area, and processes affecting loads of dissolved solids, selenium, and uranium were evaluated on the basis of geology, geochemical conditions, land and water use, and evapoconcentration.During the study period, the groundwater-flow system generally contributed flow to Fountain Creek and its hyporheic zone (as a single system) except for the reach between the north and middle transects. However, the direction of flow between the stream, the hyporheic zone, and the near-stream aquifer was variable in response to streamflow and stage. During periods of low streamflow, Fountain Creek generally gained flow from groundwater. However, during periods of high streamflow, the hydraulic gradient between groundwater and the stream temporarily reversed, causing the stream to lose flow to groundwater.Concentrations of dissolved solids, selenium, and uranium in groundwater generally had greater spatial variability than surface water or hyporheic-zone samples, and constituent concentrations in groundwater generally were greater than in surface water. Constituent concentrations in the hyporheic zone typically were similar to or intermediate between concentrations in groundwater and surface water. Concentrations of dissolved solids, selenium, uranium, and other constituents in groundwater samples collected from wells located on the east side of the north monitoring well transect were substantially greater than for other groundwater, surface-water, and hyporheic-zone samples. With one exception, groundwater samples collected from wells on the east side of the north transect exhibited oxic to mixed (oxic-anoxic) conditions, whereas most other groundwater samples exhibited anoxic to suboxic conditions. Concentrations of dissolved solids, selenium, and uranium in surface water generally increased in a downstream direction along Fountain Creek from the north transect to the south transect and exhibited an inverse relation to streamflow with highest concentration occurring during periods of low streamflow and lowest concentrations occurring during periods of high streamflow.Groundwater loads of dissolved solids, selenium, and uranium to Fountain Creek were small because of the small amount of groundwater flowing to the stream under typical low-streamflow conditions. In-stream loads of dissolved solids, selenium, and uranium in Fountain Creek varied by date, primarily in relation to streamflow at each transect and were much larger than computed constituent loads from groundwater. In-stream loads generally decreased with decreases in streamflow and increased as streamflow increased. In-stream loads of dissolved solids and selenium increased between the north and middle transects but generally decreased between the middle and south transects. By contrast, uranium loads generally decreased between the north and middle transects but increased between the middle and south transects. In-stream load differences between transects appear primarily to be related to differences in streamflow. However, because groundwater typically flows to Fountain Creek under low-flow conditions, and groundwater has greater concentrations of dissolved solids, selenium, and uranium than surface water in Fountain Creek, increases in loads between transects likely are affected by inflow of groundwater to the stream, which can account for a substantial proportion of the in-stream load difference between transects. When loads decreased between transects, the primary cause likely was decreased streamflow as a result of losses to groundwater and flow through the hyporheic zone. However, localized groundwater inflow likely attenuated the magnitude by which the in-stream loads decreased.The combination of localized soluble geologic sources and oxic conditions likely is the primary reason for the occurrence of high concentrations of dissolved solids, selenium, and uranium in groundwater on the east side of the north monitoring well transect. To evaluate conditions potentially responsible for differences in water quality and redox conditions, physical characteristics such as depth to water, saturated thickness, screen depth below the water table, screen height above bedrock, and aquifer hydraulic conductivity were compared by using Wilcoxon rank-sum tests. Results indicated no significant difference between depth to water, screen height above bedrock, and hydraulic conductivity for groundwater samples collected from wells on the east side of the north transect and groundwater samples from all other wells. However, saturated thickness and screen depth below the water table both were significantly smaller for groundwater samples collected from wells on the east side of the north transect than for groundwater samples from other wells, indicating that these characteristics might be related to the elevated constituent concentrations found at that location. Similarly, saturated thickness and screen depth below the water table were significantly smaller for groundwater samples under oxic or mixed (oxic-anoxic) conditions than for those under anoxic to suboxic conditions.The greater constituent concentrations at wells on the east side of the north transect also could, in part, be related to groundwater discharge from an unnamed alluvial drainage located directly upgradient from that location. Although the quantity and quality of water discharging from the drainage is not known, the drainage appears to collect water from a residential area located upgradient to the east of the wells, and groundwater could become concentrated in nitrate and other dissolved constituents before flowing through the drainage. High levels of nitrate, whether from anthropogenic or natural geologic sources, could promote more soluble forms of selenium and other constituents by affecting the redox condition of groundwater. Whether oxic conditions at wells on the east side of the north transect are the result of physical characteristics or of groundwater inflow from the alluvial drainage, the oxic conditions appear to cause increased dissolution of minerals from the shallow shale bedrock at that location. Because ratios of hydrogen and oxygen isotopes indicate evaporation likely has not had a substantial effect on groundwater, constituent concentrations at that location likely are not the result of evapoconcentration. 

Modeling the effects of climate and land use change on instream temperature in the Upper Tar River, North Carolina

NASA Astrophysics Data System (ADS)

Daraio, J. A.; Bales, J. D.

2011-12-01

Freshwater mussels are among the most imperiled groups of organisms in the world. Declines in abundance and diversity in North America have been attributed to a wide range of human activities, and many species occur in habitats close to their upper thermal tolerance. We are modeling instream temperature (T) as part of an effort to understand the response of imperiled freshwater mussels to anthropogenically induced changes in water T, habitat, and flow. We used the Precipitation-Runoff Modeling System (PRMS) to model projected changes in stream discharge, and the Stream Network Temperature Model (SNTEMP) to model changes in instream T due to climate and land-use change in the Upper Tar River, North Carolina, which has a drainage area of 2200 mi^2. Down-scaled gridded 12km Global Circulation Models were used for precipitation and T inputs to PRMS simulations from the present through 2060. Land-use change through 2060 in the Upper Tar basin was estimated from SLEUTH, a model that estimates land-use change using the probability of urbanization, (results available from NC State University) and incorporated into PRMS for long term simulations. Stream segment discharge and lateral and groundwater flow into each stream segment from PRMS were used as input for SNTEMP. Groundwater T was assumed equal to the average annual air T for the basin. Lateral inflow T was estimated from physical characteristics of the basin (e.g. impervious area, cover density, cover type, solar radiation, air T) when possible, or from a regression with air T based on empirical field data at 20 sites throughout the basin. In addition to T, data on mussel and fish populations (e.g., density and species composition?) and microhabitat have been collected at these sites. The SNTEMP model was calibrated using the mean daily T at each site. Nash-Sutcliffe efficiency values ranged from 0.86 to 0.94 for mean daily T, and from 0.80 to 0.93 for maximum daily T. Ensemble simulations were run for a range of climate change and land use scenarios to estimate the potential for increased instream T at each of the 20 sites. The results of these simulations will be used in conjunction with field and laboratory data on the thermal tolerances of mussels to assess the potential for elevated temperatures to adversely affect rare and common mussel populations.

Hydrologic considerations for estimation of storage-capacity requirements of impounding and side-channel reservoirs for water supply in Ohio

USGS Publications Warehouse

Koltun, G.F.

2001-01-01

This report provides data and methods to aid in the hydrologic design or evaluation of impounding reservoirs and side-channel reservoirs used for water supply in Ohio. Data from 117 streamflow-gaging stations throughout Ohio were analyzed by means of nonsequential-mass-curve-analysis techniques to develop relations between storage requirements, water demand, duration, and frequency. Information also is provided on minimum runoff for selected durations and frequencies. Systematic record lengths for the streamflow-gaging stations ranged from about 10 to 75 years; however, in many cases, additional streamflow record was synthesized. For impounding reservoirs, families of curves are provided to facilitate the estimation of storage requirements as a function of demand and the ratio of the 7-day, 2-year low flow to the mean annual flow. Information is provided with which to evaluate separately the effects of evaporation on storage requirements. Comparisons of storage requirements for impounding reservoirs determined by nonsequential-mass-curve-analysis techniques with storage requirements determined by annual-mass-curve techniques that employ probability routing to account for carryover-storage requirements indicate that large differences in computed required storages can result from the two methods, particularly for conditions where demand cannot be met from within-year storage. For side-channel reservoirs, tables of demand-storage-frequency information are provided for a primary pump relation consisting of one variable-speed pump with a pumping capacity that ranges from 0.1 to 20 times demand. Tables of adjustment ratios are provided to facilitate determination of storage requirements for 19 other pump sets consisting of assorted combinations of fixed-speed pumps or variable-speed pumps with aggregate pumping capacities smaller than or equal to the primary pump relation. The effects of evaporation on side-channel reservoir storage requirements are incorporated into the storage-requirement estimates. The effects of an instream-flow requirement equal to the 80-percent-duration flow are also incorporated into the storage-requirement estimates.

Natural and Diverted Low-Flow Duration Discharges for Streams Affected by the Waiahole Ditch System, Windward O`ahu, Hawai`i

USGS Publications Warehouse

Yeung, Chiu W.; Fontaine, Richard A.

2007-01-01

For nearly a century, the Waiahole Ditch System has diverted an average of approximately 27 million gallons per day of water from the wet, northeastern part of windward O`ahu, Hawai`i, to the dry, central part of the island to meet irrigation needs. The system intercepts large amounts of dike-impounded ground water at high altitudes (above approximately 700 to 800 ft) that previously discharged to Waiahole (and its tributaries Waianu and Uwao), Waikane, and Kahana Streams through seeps and springs. Diversion of this ground water has significantly diminished low flows in these streams. Estimates of natural and diverted flows are needed by water managers for (1) setting permanent instream flow standards to protect, enhance, and reestablish beneficial instream uses of water in the diverted streams and (2) allocating the diverted water for instream and offstream uses. Data collected before construction of the Waiahole Ditch System reflect natural (undiverted) flow conditions. Natural low-flow duration discharges for percentiles ranging from 50 to 99 percent were estimated for four sites at altitudes of 75 to 320 feet in Waiahole Stream (and its tributaries Waianu and Uwao Streams), for six sites at altitudes of 10 to 220 feet in Waikane Stream, and for three sites at altitudes of 30 to 80 feet in Kahana Stream. Among the available low-flow estimates along each affected stream, the highest natural Q50 (median) flows on Waiahole (altitude 250 ft), Waianu (altitude 75 ft), Waikane (altitude 75 ft), and Kahana Streams (altitude 30 ft) are 13, 7.0, 5.5, and 22 million gallons per day, respectively. Q50 (median) is just one of five duration percentiles presented in this report to quantify low-flow discharges. All flow-duration estimates were adjusted to a common period of 1960-2004 (called the base period). Natural flow-duration estimates compared favorably with limited pre-ditch streamflow data available for Waiahole and Kahana Streams. Data collected since construction of the ditch system reflect diverted flow conditions, which can be further divided into pre-release and post-release periods - several flow releases to Waiahole, Waianu, and Waikane Streams were initiated between December 1994 and October 2002. Comparison of pre-release to natural flows indicate that the effects of the Waiahole Ditch System diversion are consistently greater at lower low-flow conditions (Q99 to Q90) than at higher low-flow conditions (Q75 to Q50). Results also indicate that the effects of the diversion become less significant as the streams gain additional ground water at lower altitudes. For Waiahole Stream, pre-release flows range from 25 to 28 percent of natural flows at an altitude of 250 feet and from 19 to 20 percent at an altitude of 320 feet. For Waikane Stream, pre-release flows range from 30 to 46 percent of natural flows at an altitude of 10 feet and from 7 to 19 percent at an altitude of 220 feet. For Kahana Stream, pre-release flows range from 65 to 72 percent of natural flows at an altitude of 30 feet and from 58 to 71 percent at an altitude of 80 feet. Estimates of post-release flows were compared with estimates of natural flows to assess how closely current streamflows are to natural conditions. For Waianu Stream, post-release flows at an altitude of 75 feet are 41 to 46 percent lower than corresponding natural flows. For Waikane Stream, post-release flows at an altitude of 75 feet are within 12 percent of the corresponding natural flows. Comparisons of pre-release and post-release flows for Waikane Stream at altitudes of 10 to 220 feet were used to assess downstream changes in flow along the stream reach where flow releases were made. For a particular stream altitude, proportions of pre-release to post-release flows associated with median flows are consistently greater than proportions associated with lower low flows because the relative effect of the flow release is smaller at higher low flows. Similarly, for a particular f

Relations of surface-water quality to streamflow in the Atlantic Coastal, lower Delaware River, and Delaware Bay basins, New Jersey, water years 1976-93

USGS Publications Warehouse

Hunchak-Kariouk, Kathryn; Buxton, Debra E.; Hickman, R. Edward

1999-01-01

Relations of water quality to streamflow were determined for 18 water-quality constituents at 28 surface-water-quality stations within the drainage area of the Atlantic Coastal, lower Delaware River, and Delaware Bay Basins for water years 1976-93. Surface-water-quality and streamflow data were evaluated for trends (through time) in constituent concentrations during high and low flows, and relations between constituent concentration and streamflow, and between constituent load and streamflow, were determined. Median concentrations were calculated for the entire period of study (water years 1976-93) and for the last 5 years of the period of study (water years 1989-93) to determine whether any large variation in concentration exists between the two periods. Medians also were used to determine the seasonal Kendall\\'s tau statistic, which was then used to evaluate trends in concentrations during high and low flows. Trends in constituent concentrations during high and low flows were evaluated to determine whether the distribution of the observations changes through time for intermittent (nonpoint storm runoff) and constant (point sources and ground water) sources, respectively. High- and low-flow trends in concentrations were determined for some constituents at 26 of the 28 water-quality stations. Seasonal effects on the relations of concentration to streamflow are evident for 10 constituents at 14 or more stations. Dissolved oxygen shows seasonal dependency at all stations. Negative slopes of relations of concentration to streamflow, which indicate a decrease in concentration at high flows, predominate over positive slopes because of dilution of instream concentrations from storm runoff. The slopes of the regression lines of load to streamflow were determined in order to show the relative contributions to the instream load from constant (point sources and ground water) and intermittent sources (storm runoff). Greater slope values indicate larger contributions from storm runoff to instream load, which most likely indicate an increased relative importance of nonpoint sources. Load-to-streamflow relations along a stream reach that tend to increase in a downstream direction indicate the increased relative importance of contributions from storm runoff. Likewise, load-to-streamflow relations along a stream reach that tend to decrease in a downstream direction indicate the increased relative importance of point sources and ground-water discharge. The magnitudes of the load slopes for five constituents increase in the downstream direction along the Great Egg Harbor River, indicating an increased relative importance of storm runoff for these constituents along the river. The magnitudes of the load slopes for 11 constituents decrease in the downstream direction along the Assunpink Creek and for 5 constituents along the Maurice River, indicating a decreased relative importance of storm runoff for these constituents along the rivers.

Relations of surface-water quality to streamflow in the Hackensack, Passaic, Elizabeth, and Rahway River basins, New Jersey, water years 1976-93

USGS Publications Warehouse

Buxton, Debra E.; Hunchak-Kariouk, Kathryn; Hickman, R. Edward

1998-01-01

Relations of water quality to streamflow were determined for 18 water-quality constituents at 19 surface-water-quality stations within the drainage basins of the Hackensack, Passaic, Elizabeth, and Rahway Rivers in New Jersey for water years 1976-93. Surface-waterquality and streamflow data were evaluated for trends (through time) in constituent concentrations during high and low flows, and relations between constituent concentration and streamflow, and constituent load and streamflow, were determined. Median concentrations were calculated for the entire period of study (water years 1976-93) and for the last 5 years of the period of study (water years 1989-93) to determine whether any large variation in concentration exists between the two periods. Medians also were used to determine the seasonal Kendall’s tau statistic, which was then used to evaluate trends in concentrations during high and low flows.Trends in constituent concentrations during high and low flows were evaluated to determine whether the distribution of the observations changes over time for intermittent (nonpoint storm runoff) or constant (point sources and ground water) sources, respectively. Highand low-flow concentration trends were determined for some constituents at 11 of the 19 waterquality stations; 8 stations have insufficient data to determine trends. Seasonal effects on the relations of concentration to streamflow are evident for 16 of the 18 constituents. Negative slopes of relations of concentration to streamflow, which indicate a decrease in concentration at high flows, predominate over positive slopes because of dilution of instream concentrations from storm runoff.The slopes of the regression lines of load to streamflow were determined in order to show the relative contributions to the instream load from constant (point sources and ground water) and intermittent sources (storm runoff). Greater slope values suggest larger contributions from storm runoff to instream load, which most likely indicate an increased relative importance of nonpoint sources. Load-to-streamflow relations along a stream reach that tend to increase in a downstream direction indicate the increased relative importance of contributions from storm runoff. Likewise, load-to-streamflow relations along a stream reach that tend to decrease in a downstream direction indicate the increased relative importance of point sources and ground-water discharge. For most of the 18 constituents, load-to-streamflow relations at stations along a river reach remain constant or decrease in a downstream direction. The slopes increase in the downstream direction for some or all of the nutrient species at the Ramapo, lower Passaic, and Rahway Rivers; for dissolved solids, dissolved sodium, and dissolved chloride at the lower Passaic River; and for alkalinity and hardness at the Rahway River.

Macroinvertebrate instream flow studies after 20 years: A role in stream management and restoration

USGS Publications Warehouse

Gore, James A.; Layzer, James B.; Mead, Jim

2001-01-01

Over the past two decades of refinement and application of instream flow evaluations, we have examined the hydraulic habitat of aquatic macroinvertebrates in a variety of conditions, along with the role of these macroinvertebrates in sustaining ecosystem integrity. Instream flow analyses assume that predictable changes in channel flow characteristics can, in turn, be used to predict the change in the density or distribution of lotic species or, more appropriately, the availability of useable habitat for those species. Five major hydraulic conditions most affect the distribution and ecological success of lotic biota: suspended load, bedload movement, and water column effects, such as turbulence, velocity profile, and substratum interactions (near-bed hydraulics). The interactions of these hydraulic conditions upon the morphology and behavior of the individual organisms govern the distribution of aquatic biota. Historically, management decisions employing the Physical Habitat Simulation (PHABSIM) have focused upon prediction of available habitat for life stages of target fish species. Regulatory agencies have rarely included evaluation of benthos for flow reservations. Although ‘taxonomic discomfort’ may be cited for the reluctant use or creation of benthic criteria, we suggest that a basic misunderstanding of the links between benthic macroinvertebrate and the fish communities is still a problem. This is derived from the lack of a perceived ‘value’ that can be assigned to macroinvertebrate species. With the exception of endangered mussel species (for which PHABSIM analysis is probably inappropriate), this is understandable. However, it appears that there is a greater ability to predict macroinvertebrate distribution (that is, a response to the change in habitat quality or location) and diversity without complex population models. Also, habitat suitability criteria for water quality indicator taxa (Ephemeroptera, Plecoptera, and Trichoptera; the so-called ‘EPTs’) may also provide additional management options to stream regulators. The greatest application for macroinvertebrate criteria will be in low-order streams where a more immediate link to fish communities can be established. We present an example from Queens Creek, in North Carolina, USA, in which monthly allocations required to preserve the integrity of the benthic macroinvertebrate community were significantly higher than for the target benthic fish species, Cottus bairdi. In the months when both Cottus and community diversity of macroinvertebrates were the ‘bottleneck’ life stages, preservation of only fish species could result in an additional 5–25% loss in macroinvertebrate habitat. We suggest that, as there becomes an increased emphasis on maintaining macroinvertebrates as monitors of stream health, there will be a concurrent emphasis on incorporating hydraulic habitat conditions as a part of bioassessment.

Flow controls on lowland river macrophytes: a review.

PubMed

Franklin, Paul; Dunbar, Michael; Whitehead, Paul

2008-08-01

We review the current status of knowledge regarding the role that flow parameters play in controlling the macrophyte communities of temperate lowland rivers. We consider both direct and indirect effects and the interaction with other factors known to control macrophyte communities. Knowledge gaps are identified and implications for the management of river systems considered. The main factors and processes controlling the status of macrophytes in lowland rivers are velocity (hence also discharge), light, substrate, competition, nutrient status and river management practices. We suggest that whilst the characteristics of any particular macrophyte community reflect the integral effects of a combination of the factors, fundamental importance can be attributed to the role of discharge and velocity in controlling instream macrophyte colonisation, establishment and persistence. Velocity and discharge also appear to control the relative influence of some of the other controlling factors. Despite the apparent importance of velocity in determining the status of macrophyte communities in lowland rivers, relatively little is understood about the nature of the processes controlling this relationship. Quantitative knowledge is particularly lacking. Consequently, the ability to predict macrophyte abundance and distribution in rivers is still limited. This is further complicated by the likely existence of feedback effects between the growth of macrophytes and velocity. Demand for water resources increases the pressure on lowland aquatic ecosystems. Despite growing recognition of the need to allocate water for the needs of instream biota, the inability to assess the flow requirements of macrophyte communities limits the scope to achieve this. This increases the likelihood of overexploitation of the water resource as other users, whose demands are quantifiable, are prioritised.

Inferring Groundwater Age in an Alluvial Aquifer from Tracer Concentrations in the Stream - Little Wind River, Wyoming

NASA Astrophysics Data System (ADS)

Goble, D.; Gardner, W. P.; Naftz, D. L.; Solder, J. E.

2017-12-01

We use environmental tracers: CFC's, SF6, and 222Rn measured in stream water to determine volume and mean age of groundwater discharging to the Little Wind River, near Riverton, Wyoming. Samples of 222Rn were collected every 200 m along a 2 km reach, surrounding a known groundwater discharge zone. Nearby groundwater wells, in-stream piezometers and seepage meters were sampled for 222Rn, CFC's and SF6. Tracer concentrations measured in groundwater and in-stream piezometers were used to estimate the mean age of the subsurface system. High resolution 222Rn samples were used to determine the location and volume of groundwater inflow using a model of instream transport that includes radioactive decay and gas exchange with the atmosphere. The age of groundwater entering the stream was then estimated from in-stream measured CFC and SF6 concentrations using a new coupled stream transport and lumped-parameter groundwater age model. Ages derived from in-stream measurements were then compared to the age of subsurface water measured in piezometers, seepage meters, and groundwater wells. We then asses the ability of groundwater age inferred from in-stream samples to provide constraint on the age of the subsurface discharge to the stream. The ability to asses groundwater age from in-stream samples can provide a convenient method to constrain the regional distribution of groundwater circulation rates when groundwater sampling is challenging or wells are not in place.

Multistressor predictive models of invertebrate condition in the Corn Belt, USA

USGS Publications Warehouse

Waite, Ian R.; Van Metre, Peter C.

2017-01-01

Understanding the complex relations between multiple environmental stressors and ecological conditions in streams can help guide resource-management decisions. During 14 weeks in spring/summer 2013, personnel from the US Geological Survey and the US Environmental Protection Agency sampled 98 wadeable streams across the Midwest Corn Belt region of the USA for water and sediment quality, physical and habitat characteristics, and ecological communities. We used these data to develop independent predictive disturbance models for 3 macroinvertebrate metrics and a multimetric index. We developed the models based on boosted regression trees (BRT) for 3 stressor categories, land use/land cover (geographic information system [GIS]), all in-stream stressors combined (nutrients, habitat, and contaminants), and for GIS plus in-stream stressors. The GIS plus in-stream stressor models had the best overall performance with an average cross-validation R2 across all models of 0.41. The models were generally consistent in the explanatory variables selected within each stressor group across the 4 invertebrate metrics modeled. Variables related to riparian condition, substrate size or embeddedness, velocity and channel shape, nutrients (primarily NH3), and contaminants (pyrethroid degradates) were important descriptors of the invertebrate metrics. Models based on all measured in-stream stressors performed comparably to models based on GIS landscape variables, suggesting that the in-stream stressor characterization reasonably represents the dominant factors affecting invertebrate communities and that GIS variables are acting as surrogates for in-stream stressors that directly affect in-stream biota.

Testing the effects of in-stream sediment sources and sinks on simulated watershed sediment yield using the coupled U.S. Army Corps of Engineers GSSHA Model and SEDLIB Sediment Transport Library

NASA Astrophysics Data System (ADS)

Floyd, I. E.; Downer, C. W.; Brown, G.; Pradhan, N. R.

2017-12-01

The Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model is the US Army Corps of Engineers' (USACE)'s only fully coupled overland/in-stream sediment transport model. While the overland sediment transport formulation in GSSHA is considered state of the art, the existing in-stream sediment transport formulation is less robust. A major omission in the formulation of the existing GSSHA in-stream model is the lack of in-stream sources of fine materials. In this effort, we enhanced the in-stream sediment transport capacity of GSSHA by linking GSSHA to the SEDLIB sediment transport library. SEDLIB was developed at the Coastal and Hydraulics Laboratory (CHL) under the System Wide Water Resources Program (SWWRP) and Flood and Coastal (F&C) research program. It is designed to provide a library of sediment flux formulations for hydraulic and hydrologic models, such as GSSHA. This new version of GSSHA, with the updated in-stream sediment transport simulation capability afforded by the linkage to SEDLIB, was tested in against observations in an experimental watershed that had previously been used as a test bed for GSSHA. The results show a significant improvement in the ability to model in-stream sources of fine sediment. This improved capability will broaden the applicability of GSSHA to larger watersheds and watersheds with complex sediment dynamics, such as those subjected to fire hydrology.

Hg isotopes reveal in-stream processing and legacy inputs in East Fork Poplar Creek, Oak Ridge, Tennessee, USA

DOE PAGES

Demers, Jason D.; Blum, Joel D.; Brooks, Scott C.; ...

2018-03-01

In this paper, natural abundance stable Hg isotope measurements were used to place new constraints on sources, transport, and transformations of Hg along the flow path of East Fork Poplar Creek (EFPC), a point-source contaminated headwater stream in Oak Ridge, Tennessee. Particulate-bound Hg in the water column of EFPC within the Y-12 National Security Complex, was isotopically similar to average metallic Hg(0) used in industry, having a mean δ 202Hg value of -0.42 ± 0.09‰ (1SD) and near-zero Δ 199Hg. On average, particulate fraction δ 202Hg values increased downstream by 0.53‰, while Δ 199Hg decreased by -0.10‰, converging with themore » Hg isotopic composition of the fine fraction of streambed sediment along the 26 km flow path. The dissolved fraction behaved differently. Although initial Δ 199Hg values of the dissolved fraction were also near-zero, these values increased transiently along the flow path. Initial δ 202Hg values of the dissolved fraction were more variable than in the particulate fraction, ranging from -0.44 to 0.18‰ among three seasonal sampling campaigns, but converged to an average δ 202Hg value of 0.01 ± 0.10‰ (1SD) downstream. Dissolved Hg in the hyporheic and riparian pore water had higher and lower δ 202Hg values, respectively, compared to dissolved Hg in stream water. Finally, variations in Hg isotopic composition of the dissolved and suspended fractions along the flow path suggest that: (1) physical processes such as dilution and sedimentation do not fully explain decreases in total mercury concentrations along the flow path; (2) in-stream processes include photochemical reduction, but microbial reduction is likely more dominant; and (3) additional sources of dissolved mercury inputs to EFPC at baseflow during this study predominantly arise from the hyporheic zone.« less

Hg isotopes reveal in-stream processing and legacy inputs in East Fork Poplar Creek, Oak Ridge, Tennessee, USA

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

Demers, Jason D.; Blum, Joel D.; Brooks, Scott C.

In this paper, natural abundance stable Hg isotope measurements were used to place new constraints on sources, transport, and transformations of Hg along the flow path of East Fork Poplar Creek (EFPC), a point-source contaminated headwater stream in Oak Ridge, Tennessee. Particulate-bound Hg in the water column of EFPC within the Y-12 National Security Complex, was isotopically similar to average metallic Hg(0) used in industry, having a mean δ 202Hg value of -0.42 ± 0.09‰ (1SD) and near-zero Δ 199Hg. On average, particulate fraction δ 202Hg values increased downstream by 0.53‰, while Δ 199Hg decreased by -0.10‰, converging with themore » Hg isotopic composition of the fine fraction of streambed sediment along the 26 km flow path. The dissolved fraction behaved differently. Although initial Δ 199Hg values of the dissolved fraction were also near-zero, these values increased transiently along the flow path. Initial δ 202Hg values of the dissolved fraction were more variable than in the particulate fraction, ranging from -0.44 to 0.18‰ among three seasonal sampling campaigns, but converged to an average δ 202Hg value of 0.01 ± 0.10‰ (1SD) downstream. Dissolved Hg in the hyporheic and riparian pore water had higher and lower δ 202Hg values, respectively, compared to dissolved Hg in stream water. Finally, variations in Hg isotopic composition of the dissolved and suspended fractions along the flow path suggest that: (1) physical processes such as dilution and sedimentation do not fully explain decreases in total mercury concentrations along the flow path; (2) in-stream processes include photochemical reduction, but microbial reduction is likely more dominant; and (3) additional sources of dissolved mercury inputs to EFPC at baseflow during this study predominantly arise from the hyporheic zone.« less

Effects of flood control and other reservoir operations on the water quality of the lower Roanoke River, North Carolina

USGS Publications Warehouse

Garcia, Ana Maria

2012-01-01

The Roanoke River is an important natural resource for North Carolina, Virginia, and the Nation. Flood plains of the lower Roanoke River, which extend from Roanoke Rapids Dam to Batchelor Bay near Albemarle Sound, support a large and diverse population of nesting birds, waterfowl, freshwater and anadromous fish, and other wildlife, including threatened and endangered species. The flow regime of the lower Roanoke River is affected by a number of factors, including flood-management operations at the upstream John H. Kerr Dam and Reservoir. A three-dimensional, numerical water-quality model was developed to explore links between upstream flows and downstream water quality, specifically in-stream dissolved-oxygen dynamics. Calibration of the hydrodynamics and dissolved-oxygen concentrations emphasized the effect that flood-plain drainage has on water and oxygen levels, especially at locations more than 40 kilometers away from the Roanoke Rapids Dam. Model hydrodynamics were calibrated at three locations on the lower Roanoke River, yielding coefficients of determination between 0.5 and 0.9. Dissolved-oxygen concentrations were calibrated at the same sites, and coefficients of determination ranged between 0.6 and 0.8. The model has been used to quantify relations among river flow, flood-plain water level, and in-stream dissolved-oxygen concentrations in support of management of operations of the John H. Kerr Dam, which affects overall flows in the lower Roanoke River. Scenarios have been developed to mitigate the negative effects that timing, duration, and extent of flood-plain inundation may have on vegetation, wildlife, and fisheries in the lower Roanoke River corridor. Under specific scenarios, the model predicted that mean dissolved-oxygen concentrations could be increased by 15 percent by flow-release schedules that minimize the drainage of anoxic flood-plain waters. The model provides a tool for water-quality managers that can help identify options that improve water quality and protect the aquatic habitat of the Roanoke River.

Measuring the economic benefit of maintaining the ecological integrity of the Río Mameyes in Puerto Rico.

Treesearch

Armando González-Cabán; John Loomis

1999-01-01

A contingent valuation in-person survey of Puerto Rican households was performed from April to August 1995 to estimate their willingness-to-pay for preserving instream flows in the Río Mameyes and avoiding a dam on the Río Fajardo. Annual willingness-to-pay was $21 for each river. When expanded to the 1 million households in Puerto Rico for the 5-year period households...

Habitat Suitability Index Models and Instream Flow Suitability Curves: Warmouth

USGS Publications Warehouse

McMahon, Thomas E.; Gebhart, Glen; Maughan, O. Eugene; Nelson, Patrick C.

1984-01-01

The wa rmouth (Lepomi s gul osus) occurs naturally throughout the central and southeastern United States. It is distributed throughout Kansas, Iowa, and Missouri, north to southern Wisconsin, lower Michigan, Lake Erie, and western Pennsylvania, and south to Florida and west through the Gulf States to the Rio Grande (Hubbs and Lagler 1947; Larimore 1957). It has been introduced into California (Hubble 1966; Moyle 1976), Arizona (Minckley 1973), and other western states (Smith 1896).

Supplement Analysis for the Watershed Management Program EIS (DOE/EIS-0265/SA-66)

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

N /A

2001-10-04

BPA proposes to fund four projects that will enhance instream flow in several subbasins throughout Oregon. The Oregon Water Trust acquires existing water rights on a voluntary basis through purchase, gift and water conservation projects, and converts the rights to instream flow under Oregon state water law. The proposed projects are all related to an on-going program of water rights acquisition in the Columbia Plateau Basin (Deschutes, John Day, Umatilla and Walla Walla subbasins) and the Columbia Gorge Basin (Fifteenmile subbasin) by the Oregon Water Trust (OWT). The current funding cycle extends through fiscal year 2001. Additional funding is currentlymore » being sought for fiscal years 2002-2004. Specific acquisition transactions are evaluated throughout the duration of the project, so on-the-ground impacts may only be estimated. The proposed project is an extension of previous water rights acquisition projects within the subject subbasins, dating back to 1994. The objective of the proposed projects in the next cycle, 2002 through 2004, is to acquire a total of approximately 12.6 cfs on tributary streams within the subbasins. The target level of water rights acquired, by subbasin, are as follows: Deschutes subbasin--2.0 cfs; Fifteenmile subbasin--1.4 cfs; John Day subbasin--2.0 cfs; Umatilla subbasin--1.0 cfs; Walla Walla subbasin--4.2 cfs; and newly prioritized streams within the region--2.0 cfs.« less

14 CFR 25.1443 - Minimum mass flow of supplemental oxygen.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Minimum mass flow of supplemental oxygen... § 25.1443 Minimum mass flow of supplemental oxygen. (a) If continuous flow equipment is installed for use by flight crewmembers, the minimum mass flow of supplemental oxygen required for each crewmember...

14 CFR 25.1443 - Minimum mass flow of supplemental oxygen.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Minimum mass flow of supplemental oxygen... § 25.1443 Minimum mass flow of supplemental oxygen. (a) If continuous flow equipment is installed for use by flight crewmembers, the minimum mass flow of supplemental oxygen required for each crewmember...

14 CFR 25.1443 - Minimum mass flow of supplemental oxygen.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Minimum mass flow of supplemental oxygen... § 25.1443 Minimum mass flow of supplemental oxygen. (a) If continuous flow equipment is installed for use by flight crewmembers, the minimum mass flow of supplemental oxygen required for each crewmember...

14 CFR 25.1443 - Minimum mass flow of supplemental oxygen.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Minimum mass flow of supplemental oxygen... § 25.1443 Minimum mass flow of supplemental oxygen. (a) If continuous flow equipment is installed for use by flight crewmembers, the minimum mass flow of supplemental oxygen required for each crewmember...

Consideration of exposure and species sensitivity of triclosan in the freshwater environment.

PubMed

Capdevielle, Marie; Van Egmond, Roger; Whelan, Mick; Versteeg, Donald; Hofmann-Kamensky, Matthias; Inauen, Josef; Cunningham, Virginia; Woltering, Daniel

2008-01-01

Triclosan (TCS) is a broad-spectrum antimicrobial used in consumer products including toothpaste and hand soap. After being used, TCS is washed or rinsed off and residuals that are not biodegraded or otherwise removed during wastewater treatment can enter the aquatic environment in wastewater effluents and sludges. The environmental exposure and toxicity of TCS has been the subject of various scientific and regulatory discussions in recent years. There have been a number of publications in the past 5 y reporting toxicity, fate and transport, and in-stream monitoring data as well as predictions from aquatic risk assessments. State-of-the-science probabilistic exposure models, including Geography-referenced Regional Exposure Assessment Tool for European Rivers (GREAT-ER) for European surface waters and Pharmaceutical Assessment and Transport Evalutation (PhATE) for US surface waters, have been used to predict in-stream concentrations (PECs). These models take into account spatial and temporal variability in river flows and wastewater emissions based on empirically derived estimates of chemical removal in wastewater treatment and in receiving waters. These model simulations (based on realistic use levels of TCS) have been validated with river monitoring data in areas known to be receiving high wastewater loads. The results suggest that 90th percentile (low flow) TCS concentrations are less than 200 ng/L for the Aire-Calder catchment in the United Kingdom and between 250 ng/L (with in-stream removal) and 850 ng/L (without in-stream removal) for a range of US surface waters. To better identify the aquatic risk of TCS, a species sensitivity distribution (SSD) was constructed based on chronic toxicity values, either no observed effect concentrations (NOECs) or various percentile adverse effect concentrations (EC10-25 values) for 14 aquatic species including fish, invertebrates, macrophytes, and algae. The SSD approach is believed to represent a more realistic threshold of effect than a predicted no effect concentration (PNEC) based on the data from the single most sensitive species tested. The log-logistic SSD was used to estimate a PNEC, based on an HC5,50 (the concentration estimated to affect the survival, reproduction and/or growth of 5% of species with a 50% confidence interval). The PNEC for TCS was 1,550 ng/L. Comparing the SSD-based PNEC with the PECs derived from GREATER and PhATE modeling to simulate in-river conditions in Europe and the United States, the PEC to PNEC ratios are less than unity suggesting risks to pelagic species are low even under the highest likely exposures which would occur immediately downstream of wastewater treatment plant (WWTP) discharge points. In-stream sorption, biodegradation, and photodegradation will further reduce pelagic exposures of TCS. Monitoring data in Europe and the United States corroborate the modeled PEC estimates and reductions in TCS concentrations with distance downstream of WWTP discharges. Environmental metabolites, bioaccumulation, biochemical responses including endocrine-related effects, and community level effects are far less well studied for this chemical but are addressed in the discussion. The aquatic risk assessment for TCS should be refined as additional information becomes available.

Temporal dynamics of instream wood in headwater streams draining mixed Carpathian forests

NASA Astrophysics Data System (ADS)

Galia, Tomáš; Šilhán, Karel; Ruiz-Villanueva, Virginia; Tichavský, Radek; Stoffel, Markus

2017-09-01

Instream wood can reside in fluvial systems over varying periods depending on its geographical context, instream position, tree species, piece size, and fluvial environment. In this paper, we investigate the residence time of two typical species representing a majority of instream wood in steep headwaters of the Carpathians and located under mixed forest canopy. Residence times of individual logs were then confronted with other wood parameters (i.e., wood dimensions, mean annual increment rate, tree age, class of wood stabilisation and decay, geomorphic function of wood pieces, and the proportion of the log length within the active channel). Norway spruce (Picea abies (L.) Karst.) samples indicated more than two times longer mean and maximal residence times as compared to European beech (Fagus sylvatica L.) based on the successful cross-dating of 127 logs. Maximum residence time in the headwaters was 128 years for P. abies and 59 years for F. sylvatica. We demonstrate that log age and log diameter played an important role in the preservation of wood in the fluvial system, especially in the case of F. sylvatica instream wood. By contrast, we did not observe any significant trends between wood residence time and total wood length. Instream wood with geomorphic functions (i.e., formation of steps and jams) did not show any differences in residence time as compared to nonfunctional wood. Nevertheless, we found shorter residence times for hillslope-stabilised pieces when compared to pieces located entirely in the channel (either unattached or stabilised by other wood or bed sediments). We also observed changes of instream wood orientation with respect to wood residence time. This suggests some movement of instream wood (i.e., its turning or short-distance transport), including pieces longer than channel width in the steep headwaters studied here (1.5 ≤ W ≤ 3.5 m), over the past few decades.

Quantifying hyporheic exchange at high spatial resolution using natural temperature variations along a first-order stream

NASA Astrophysics Data System (ADS)

Westhoff, M. C.; Gooseff, M. N.; Bogaard, T. A.; Savenije, H. H. G.

2011-10-01

Hyporheic exchange is an important process that underpins stream ecosystem function, and there have been numerous ways to characterize and quantify exchange flow rates and hyporheic zone size. The most common approach, using conservative stream tracer experiments and 1-D solute transport modeling, results in oversimplified representations of the system. Here we present a new approach to quantify hyporheic exchange and the size of the hyporheic zone (HZ) using high-resolution temperature measurements and a coupled 1-D transient storage and energy balance model to simulate in-stream water temperatures. Distributed temperature sensing was used to observe in-stream water temperatures with a spatial and temporal resolution of 2 and 3 min, respectively. The hyporheic exchange coefficient (which describes the rate of exchange) and the volume of the HZ were determined to range between 0 and 2.7 × 10-3 s-1 and 0 and 0.032 m3 m-1, respectively, at a spatial resolution of 1-10 m, by simulating a time series of in-stream water temperatures along a 565 m long stretch of a small first-order stream in central Luxembourg. As opposed to conventional stream tracer tests, two advantages of this approach are that exchange parameters can be determined for any stream segment over which data have been collected and that the depth of the HZ can be estimated as well. Although the presented method was tested on a small stream, it has potential for any stream where rapid (in regard to time) temperature change of a few degrees can be obtained.

Comparison of Instream and Laboratory Methods of Measuring Sediment Oxygen Demand

USGS Publications Warehouse

Hall, Dennis C.; Berkas, Wayne R.

1988-01-01

Sediment oxygen demand (SOD) was determined at three sites in a gravel-bottomed central Missouri stream by: (1) two variations of an instream method, and (2) a laboratory method. SOD generally was greatest by the instream methods, which are considered more accurate, and least by the laboratory method. Disturbing stream sediment did not significantly decrease SOD by the instream method. Temperature ranges of up to 12 degree Celsius had no significant effect on the SOD. In the gravel-bottomed stream, the placement of chambers was critical to obtain reliable measurements. SOD rates were dependent on the method; therefore, care should be taken in comparing SOD data obtained by different methods. There is a need for a carefully researched standardized method for SOD determinations.

Optical Measurements at the Combustor Exit of the HIFiRE 2 Ground Test Engine

NASA Technical Reports Server (NTRS)

Brown, Michael S.; Herring, Gregory C.; Cabell, Karen; Hass, Neal; Barhorst, Todd F.; Gruber, Mark

2012-01-01

The development of optical techniques capable of measuring in-stream flow properties of air breathing hypersonic engines is a goal of the Aerospace Propulsion Division at AFRL. Of particular interest are techniques such as tunable diode laser absorption spectroscopy that can be implemented in both ground and flight test efforts. We recently executed a measurement campaign at the exit of the combustor of the HIFiRE 2 ground test engine during Phase II operation of the engine. Data was collected in anticipation of similar data sets to be collected during the flight experiment. The ground test optical data provides a means to evaluate signal processing algorithms particularly those associated with limited line of sight tomography. Equally important, this in-stream data was collected to compliment data acquired with surface-mounted instrumentation and the accompanying flowpath modeling efforts-both CFD and lower order modeling. Here we discuss the specifics of hardware and data collection along with a coarse-grained look at the acquired data and our approach to processing and analyzing it.

"HIP" new software: The Hydroecological Integrity Assessment Process

USGS Publications Warehouse

Henriksen, Jim; Wilson, Juliette T.

2006-01-01

Center (FORT) have developed the Hydroecological Integrity Assessment Process (HIP) and a suite of software tools for conducting a hydrologic classification of streams, addressing instream flow needs, and assessing past and proposed hydrologic alterations on streamflow and other ecosystem components. The HIP recognizes that streamflow is strongly related to many critical physiochemical components of rivers, such as dissolved oxygen, channel geomorphology, and habitats. Streamflow is considered a “master variable” that limits the distribution, abundance, and diversity of many aquatic plant and animal species.

sedFlow - an efficient tool for simulating bedload transport, bed roughness, and longitudinal profile evolution in mountain streams

NASA Astrophysics Data System (ADS)

Heimann, F. U. M.; Rickenmann, D.; Turowski, J. M.; Kirchner, J. W.

2014-07-01

Especially in mountainuous environments, the prediction of sediment dynamics is important for managing natural hazards, assessing in-stream habitats, and understanding geomorphic evolution. We present the new modelling tool sedFlow for simulating fractional bedload transport dynamics in mountain streams. The model can deal with the effects of adverse slopes and uses state of the art approaches for quantifying macro-roughness effects in steep channels. Local grain size distributions are dynamically adjusted according to the transport dynamics of each grain size fraction. The tool sedFlow features fast calculations and straightforward pre- and postprocessing of simulation data. The model is provided together with its complete source code free of charge under the terms of the GNU General Public License (www.wsl.ch/sedFlow). Examples of the application of sedFlow are given in a companion article by Heimann et al. (2014).

Workshop report - A validation study of Navier-Stokes codes for transverse injection into a Mach 2 flow

NASA Technical Reports Server (NTRS)

Eklund, Dean R.; Northam, G. B.; Mcdaniel, J. C.; Smith, Cliff

1992-01-01

A CFD (Computational Fluid Dynamics) competition was held at the Third Scramjet Combustor Modeling Workshop to assess the current state-of-the-art in CFD codes for the analysis of scramjet combustors. Solutions from six three-dimensional Navier-Stokes codes were compared for the case of staged injection of air behind a step into a Mach 2 flow. This case was investigated experimentally at the University of Virginia and extensive in-stream data was obtained. Code-to-code comparisons have been made with regard to both accuracy and efficiency. The turbulence models employed in the solutions are believed to be a major source of discrepancy between the six solutions.

Reservoir Control Center: Activities and Accomplishments of the Southwestern Division of the Army Corps of Engineers Related to Reservoir Regulation and Water Management. Part 3. Instream Flow Study. Appendix A.

DTIC Science & Technology

1981-01-01

Inoduction I.. WHITE RIVER BASIN Bover Whilte LRD AR 66 1120,0 1130,0 1652 300 5 Table Rock White LRD AR/MO 58 915.0 931.0 2702 760 526 Bull Shoals...Benbrook Trinity 391 Big Hill Arkansas 120 Birch Arkansas 151 Blue Mountain Arkansas 266 Broken Bow Red 331 Bull Shoals White 15 Canton Arkansas 234 Canyon...RELAT IONS fPqnC FRCcn :324-M24) AT DAM SITE OCTOBER~ FLOWS (PER~ TIpO C REVZR CC?45-1T7NS U.. MY ENGINEER DISTRICT. FORT WORTH TO RCCCMDR4Y tNSTR~qr

Calibration of HYPULSE for hypervelocity air flows corresponding to flight Mach numbers 13.5, 15, and 17

NASA Technical Reports Server (NTRS)

Calleja, John; Tamagno, Jose

1993-01-01

A series of air calibration tests were performed in GASL's HYPULSE facility in order to more accurately determine test section flow conditions for flows simulating total enthalpies in the Mach 13 to 17 range. Present calibration data supplements previous data and includes direct measurement of test section pitot and static pressure, acceleration tube wall pressure and heat transfer, and primary and secondary incident shock velocities. Useful test core diameters along with the corresponding free-stream conditions and usable testing times were determined. For the M13.5 condition, in-stream static pressure surveys showed the temporal and spacial uniformity of this quantity across the useful test core. In addition, finite fringe interferograms taken of the free-stream flow at the test section did not indicate the presence of any 'strong' wave system for any of the conditions investigated.

Integrating the pulse of the riverscape and landscape: modelling stream metabolism using continuous dissolved oxygen measurements

NASA Astrophysics Data System (ADS)

Soulsby, C.; Birkel, C.; Malcolm, I.; Tetzlaff, D.

2013-12-01

Stream metabolism is a fundamental pulse of the watershed which reflects both the in-stream environment and its connectivity with the wider landscape. We used high quality, continuous (15 minute), long-term (>3 years) measurement of stream dissolved oxygen (DO) concentrations to estimate photosynthetic productivity (P) and system respiration (R) in forest and moorland reaches of an upland stream with peaty soils. We calibrated a simple five parameter numerical oxygen mass balance model driven by radiation, stream and air temperature, stream depth and re-aeration capacity. This used continuous 24-hour periods for the whole time series to identify behavioural simulations where DO simulations were re-produced sufficiently well to be considered reasonable representations of ecosystem functioning. Results were evaluated using a seasonal Regional Sensitivity Analysis and a co-linearity index for parameter sensitivity. This showed that >95 % of the behavioural models for the moorland and forest sites were identifiable and able to infer in-stream processes from the DO time series for almost half of all measured days at both sites. Days when the model failed to simulate DO levels successfully provided invaluable insight into time periods when other factors are likely to disrupt in-stream metabolic processes; these include (a) flood events when scour reduces the biomass of benthic primary producers, (b) periods of high water colour in higher summer/autumn flows and (c) low flow periods when hyporheic respiration is evident. Monthly P/R ratios <1 indicate a heterotrophic system with both sites exhibiting similar temporal patterns; with a maximum in February and a second peak during summer months. However, the estimated net ecosystem productivity (NPP) suggests that the moorland reach without riparian tree cover is likely to be a much larger source of carbon to the atmosphere (122 mmol C m-2 d-1) compared to the forested reach (64 mmol C m-2 d-1). The study indicates the value of integrating field and modelling studies of stream metabolism as a means of understanding the dynamic interactions of the riverscape and its surrounding landscape.

Relations between habitat variability and population dynamics of bass in the Huron River, Michigan

USGS Publications Warehouse

Bovee, Ken D.; Newcomb, Tammy J.; Coon, Thomas G.

1994-01-01

One of the assumption of the Instream Flow Incremental Methodology (IFIM) is that the dynamics of fish populations are directly or indirectly related to habitat availability. Because this assumption has not been successfully tested in coolwater streams, questions arise regarding the validity of the methodology in such streams. The purpose of our study was to determine whether relations existed between habitat availability and population dynamics of smallmouth bass (Micropterus dolomieu) and rock bass (Ambloplites rupestris) in a 16-km reach of the Huron River in southeastern Michigan. Both species exhibited strong to moderate carryover of year classes from age 0 through age 2, indicating that adult populations were related to factors affecting recruitment. Year-class strength and subsequent numbers of yearling bass were related to the availability of young-of-year habitat during the first growing season for a cohort. Number of age-0, age-1, and adult smallmouth bass were related to the average length at age 0 for the cohort. Length at age 0 was associated with young-of-year habitat and thermal regime during the first growing season. Rock bass populations exhibited similar associations among age classes and habitat variables. Compared to smallmouth bass, the number of age-2 rock bass was associated more closely with their length at age 0 than with year-class strength. Length at age 0 and year-class strength of rock bass were associated with the same habitat variables as those related to age-0 smallmouth bass. We hypothesize that an energetic mechanism linked thermal regime to length at age 0 and that increased growth resulted in higher survival rates from age 0 to age 1. We also postulate that young-of-year habitat provided protection from predators, higher production of food resources, and increased foraging efficiency. We conclude that the IFIM is a valid methodology for instream flow investigations of coolwater streams. The results for our study support the contention that the dynamics of bass populations are directly or indirectly related to habitat availability in coolwater streams. Our study also revealed several implications related to the operational application of the IFIM in coolwater streams: 1. Greater emphasis should be placed on the alleviation of habitat impacts to early life history phases of bass. 2. Effects of the thermal regime are important in some coolwater streams even if temperatures remain within nonlethal limits. Degree-day analyses should be routinely included in study plans for applications of the IFIM in coolwater streams. 3. The smallest amount of habitat occurring within or across years is not necessarily the most significant event affecting population dynamics. The timing of extreme events can be as important as their magnitude. 4. Population-related habitat limitations were associated with high flows more often than with low flows (although both occurred). Negotiations that focus only on minimum flows may preclude viable water management options and ignore significant biological events. This finding is particularly relevant to negotiations involving hydrospeaking operations. 5. IFIM users are advised to consider the use of binary criteria in place of conventional suitability index curves in microhabitat simulations. Criteria defining the optimal ranges of variables are preferable to broader rangers, and criteria that simply define suitable conditions should be avoided entirely.

Reference manual for generation and analysis of Habitat Time Series: version II

USGS Publications Warehouse

Milhous, Robert T.; Bartholow, John M.; Updike, Marlys A.; Moos, Alan R.

1990-01-01

The selection of an instream flow requirement for water resource management often requires the review of how the physical habitat changes through time. This review is referred to as 'Time Series Analysis." The Tune Series Library (fSLIB) is a group of programs to enter, transform, analyze, and display time series data for use in stream habitat assessment. A time series may be defined as a sequence of data recorded or calculated over time. Examples might be historical monthly flow, predicted monthly weighted usable area, daily electrical power generation, annual irrigation diversion, and so forth. The time series can be analyzed, both descriptively and analytically, to understand the importance of the variation in the events over time. This is especially useful in the development of instream flow needs based on habitat availability. The TSLIB group of programs assumes that you have an adequate study plan to guide you in your analysis. You need to already have knowledge about such things as time period and time step, species and life stages to consider, and appropriate comparisons or statistics to be produced and displayed or tabulated. Knowing your destination, you must first evaluate whether TSLIB can get you there. Remember, data are not answers. This publication is a reference manual to TSLIB and is intended to be a guide to the process of using the various programs in TSLIB. This manual is essentially limited to the hands-on use of the various programs. a TSLIB use interface program (called RTSM) has been developed to provide an integrated working environment where the use has a brief on-line description of each TSLIB program with the capability to run the TSLIB program while in the user interface. For information on the RTSM program, refer to Appendix F. Before applying the computer models described herein, it is recommended that the user enroll in the short course "Problem Solving with the Instream Flow Incremental Methodology (IFIM)." This course is offered by the Aquatic Systems Branch of the National Ecology Research Center. For more information about the TSLIB software, refer to the Memorandum of Understanding. Chapter 1 provides a brief introduction to the Instream Flow Incremental Methodology and TSLIB. Other chapters in this manual provide information on the different aspects of using the models. The information contained in the other chapters includes (2) acquisition, entry, manipulation, and listing of streamflow data; (3) entry, manipulation, and listing of the habitat-versus-streamflow function; (4) transferring streamflow data; (5) water resources systems analysis; (6) generation and analysis of daily streamflow and habitat values; (7) generation of the time series of monthly habitats; (8) manipulation, analysis, and display of month time series data; and (9) generation, analysis, and display of annual time series data. Each section includes documentation for the programs therein with at least one page of information for each program, including a program description, instructions for running the program, and sample output. The Appendixes contain the following: (A) sample file formats; (B) descriptions of default filenames; (C) alphabetical summary of batch-procedure files; (D) installing and running TSLIB on a microcomputer; (E) running TSLIB on a CDC Cyber computer; (F) using the TSLIB user interface program (RTSM); and (G) running WATSTORE on the USGS Amdahl mainframe computer. The number for this version of TSLIB--Version II-- is somewhat arbitrary, as the TSLIB programs were collected into a library some time ago; but operators tended to use and manage them as individual programs. Therefore, we will consider the group of programs from the past that were only on the CDC Cyber computer as Version 0; the programs from the past that were on both the Cyber and the IBM-compatible microcomputer as Version I; and the programs contained in this reference manual as Version II.

Stream vulnerability to widespread and emergent stressors: a focus on unconventional oil and gas

USGS Publications Warehouse

Entrekin, Sally; Maloney, Kelly O.; Katherine E. Kapo,; Walters, Annika W.; Evans-White, Michelle A.; Klemow, Kenneth M.

2015-01-01

Multiple stressors threaten stream physical and biological quality, including elevated nutrients and other contaminants, riparian and in-stream habitat degradation and altered natural flow regime. Unconventional oil and gas (UOG) development is one emerging stressor that spans the U.S. UOG development could alter stream sedimentation, riparian extent and composition, in-stream flow, and water quality. We developed indices to describe the watershed sensitivity and exposure to natural and anthropogenic disturbances and computed a vulnerability index from these two scores across stream catchments in six productive shale plays. We predicted that catchment vulnerability scores would vary across plays due to climatic, geologic and anthropogenic differences. Across-shale averages supported this prediction revealing differences in catchment sensitivity, exposure, and vulnerability scores that resulted from different natural and anthropogenic environmental conditions. For example, semi-arid Western shale play catchments (Mowry, Hilliard, and Bakken) tended to be more sensitive to stressors due to low annual average precipitation and extensive grassland. Catchments in the Barnett and Marcellus-Utica were naturally sensitive from more erosive soils and steeper catchment slopes, but these catchments also experienced areas with greater UOG densities and urbanization. Our analysis suggested Fayetteville and Barnett catchments were vulnerable due to existing anthropogenic exposure. However, all shale plays had catchments that spanned a wide vulnerability gradient. Our results identify vulnerable catchments that can help prioritize stream protection and monitoring efforts. Resource managers can also use these findings to guide local development activities to help reduce possible environmental effects.

Stream Vulnerability to Widespread and Emergent Stressors: A Focus on Unconventional Oil and Gas

PubMed Central

Entrekin, Sally A.; Maloney, Kelly O.; Kapo, Katherine E.; Walters, Annika W.; Evans-White, Michelle A.; Klemow, Kenneth M.

2015-01-01

Multiple stressors threaten stream physical and biological quality, including elevated nutrients and other contaminants, riparian and in-stream habitat degradation and altered natural flow regime. Unconventional oil and gas (UOG) development is one emerging stressor that spans the U.S. UOG development could alter stream sedimentation, riparian extent and composition, in-stream flow, and water quality. We developed indices to describe the watershed sensitivity and exposure to natural and anthropogenic disturbances and computed a vulnerability index from these two scores across stream catchments in six productive shale plays. We predicted that catchment vulnerability scores would vary across plays due to climatic, geologic and anthropogenic differences. Across-shale averages supported this prediction revealing differences in catchment sensitivity, exposure, and vulnerability scores that resulted from different natural and anthropogenic environmental conditions. For example, semi-arid Western shale play catchments (Mowry, Hilliard, and Bakken) tended to be more sensitive to stressors due to low annual average precipitation and extensive grassland. Catchments in the Barnett and Marcellus-Utica were naturally sensitive from more erosive soils and steeper catchment slopes, but these catchments also experienced areas with greater UOG densities and urbanization. Our analysis suggested Fayetteville and Barnett catchments were vulnerable due to existing anthropogenic exposure. However, all shale plays had catchments that spanned a wide vulnerability gradient. Our results identify vulnerable catchments that can help prioritize stream protection and monitoring efforts. Resource managers can also use these findings to guide local development activities to help reduce possible environmental effects. PMID:26397727

Impacts of climate change on in-stream nitrogen in a lowland chalk stream: an appraisal of adaptation strategies.

PubMed

Whitehead, P G; Wilby, R L; Butterfield, D; Wade, A J

2006-07-15

The impacts of climate change on nitrogen (N) in a lowland chalk stream are investigated using a dynamic modelling approach. The INCA-N model is used to simulate transient daily hydrology and water quality in the River Kennet using temperature and precipitation scenarios downscaled from the General Circulation Model (GCM) output for the period 1961-2100. The three GCMs (CGCM2, CSIRO and HadCM3) yield very different river flow regimes with the latter projecting significant periods of drought in the second half of the 21st century. Stream-water N concentrations increase over time as higher temperatures enhance N release from the soil, and lower river flows reduce the dilution capacity of the river. Particular problems are shown to occur following severe droughts when N mineralization is high and the subsequent breaking of the drought releases high nitrate loads into the river system. Possible strategies for reducing climate-driven N loads are explored using INCA-N. The measures include land use change or fertiliser reduction, reduction in atmospheric nitrate and ammonium deposition, and the introduction of water meadows or connected wetlands adjacent to the river. The most effective strategy is to change land use or reduce fertiliser use, followed by water meadow creation, and atmospheric pollution controls. Finally, a combined approach involving all three strategies is investigated and shown to reduce in-stream nitrate concentrations to those pre-1950s even under climate change.

Engineered channel controls limiting spawning habitat rehabilitation success on regulated gravel-bed rivers

NASA Astrophysics Data System (ADS)

Brown, Rocko A.; Pasternack, Gregory B.

2008-05-01

In efforts to rehabilitate regulated rivers for ecological benefits, the flow regime has been one of the primary focal points of management strategies. However, channel engineering can impact channel geometry such that hydraulic and geomorphic responses to flow reregulation do not yield the sought for benefits. To illustrate and assess the impacts of structural channel controls and flow reregulation on channel processes and fish habitat quality in multiple life stages, a highly detailed digital elevation model was collected and analyzed for a river reach right below a dam using a suite of hydrologic, hydraulic, geomorphic, and ecological methods. Results showed that, despite flow reregulation to produce a scaled-down natural hydrograph, anthropogenic boundary controls have severely altered geomorphic processes associated with geomorphic self-sustainability and instream habitat availability in the case study. Given the similarity of this stream to many others, we concluded that the potential utility of natural flow regime reinstatement in regulated gravel-bed rivers is conditional on concomitant channel rehabilitation.

Preliminary effects of streambank fencing of pasture land on the quality of surface water in a small watershed in Lancaster County, Pennsylvania

USGS Publications Warehouse

Galeone, Daniel G.

2000-01-01

The use of fencing to exclude pastured animals from streams has been recognized as an agricultural best-management practice. Streambank fencing was installed in a small basin within the Mill Creek Watershed of Lancaster County, Pa., during summer 1997 to evaluate the effectiveness of fencing on surface-water quality. A preliminary review of data collected during a pre-treatment, or calibration period (October 1993 through June 1997), and part of the post-treatment period (July 1997 through November 1998) has identified a varied instream nutrient response to streambank fencing.Concentrations of total nitrogen (N) during low-flow periods were significantly reduced by 20 to 31 percent at treated relative to untreated sites, but the yield of total N during low-flow conditions did not change significantly. Low-flow concentrations and yields of total phosphorus (P) did not change significantly at the outlet of the treatment basin, but data from a tributary site (T-2) in the treatment basin showed a 19- to 79-percent increase in the concentration and yield of total P relative to those at untreated sites. The total-P increase was due to increased concentrations of dissolved P. The processes causing the decrease in the concentration of total N and an increase in the concentration of total P were related to stream discharge, which declined after fencing to about one-third lower than the period-of-record mean. Declines in stream discharge after fence installation were caused by lower than normal precipitation. As concentrations of dissolved oxygen decreased in the stream channel as flows decreased, there was increased potential for instream denitrification and solubilization of P from sediments in the stream channel. Vegetative uptake of nitrate could also have contributed to decreased N concentrations. There were few significant changes in concentrations and yields of nutrients during stormflow except for significant reductions of 16 percent for total-N concentrations and 26 percent for total-P concentrations at site T-2 relative to the site at the outlet of the control basin.Suspended-sediment concentrations in the stream were significantly reduced by fencing. These reductions were partially caused by reduced cow access to the stream and hence reduced potential for the cows to destabilize streambanks through trampling. Development of a vegetative buffer along the stream channel after fence installation also helped to retain soil eroding from upgradient land. Reductions in suspended sediment during low flow ranged from 17 to 26 percent; stormflow reductions in suspended sediment ranged from 21 to 54 percent at treated relative to untreated sites. Suspended-sediment yields, however, were significantly reduced only at site T-2, where low-flow and stormflow yields were reduced by about 25 and 10 percent, respectively, relative to untreated sites.Benthic-macroinvertebrate sampling has identified increased number of taxa in the treatment basin after fence installation. Relative to the control basin, there was about a 30-percent increase in the total number of taxa. This increase was most likely related to improved instream habitat as a result of channel revegetation.

The behaviour of 39 pesticides in surface waters as a function of scale

USGS Publications Warehouse

Capel, P.D.; Larson, S.J.; Winterstein, T.A.

2001-01-01

A portion of applied pesticides runs off agricultural fields and is transported through surface waters. In this study, the behaviour of 39 pesticides is examined as a function of scale across 14 orders of magnitude from the field to the ocean. Data on pesticide loads in streams from two US Geological Survey programs were combined with literature data from field and watershed studies. The annual load as percent of use (LAPU) was quantified for each of the fields and watersheds and was used as the normalization factor across watersheds and compounds. The in-stream losses of each pesticide were estimated for a model stream with a 15 day travel time (similar in characteristics to the upper Mississippi River). These estimated in-stream losses agreed well with the observed changes in apparent LAPU values as a function of watershed area. In general, herbicides applied to the soil surface had the greatest LAPU values and minimal in-stream losses. Soil-incorporated herbicides had smaller LAPU values and substantial in-stream losses. Insecticides generally had LAPU values similar to the incorporated herbicides, but had more variation in their in-stream losses. On the basis of the LAPU values of the 39 pesticides as a function of watershed area, a generalized conceptual model of the movement of pesticides from the field to the ocean is suggested. The importance of considering both field runoff and in-stream losses is discussed in relation to interpreting monitoring data and making regulatory decisions.

Simulation of hydrodynamics, temperature, and dissolved oxygen in Beaver Lake, Arkansas, 1994-1995

USGS Publications Warehouse

Haggard, Brian; Green, W. Reed

2002-01-01

The tailwaters of Beaver Lake and other White River reservoirs support a cold-water trout fishery of significant economic yield in northwestern Arkansas. The Arkansas Game and Fish Commission has requested an increase in existing minimum flows through the Beaver Lake dam to increase the amount of fishable waters downstream. Information is needed to assess the impact of additional minimum flows on temperature and dissolved-oxygen qualities of reservoir water above the dam and the release water. A two-dimensional, laterally averaged hydrodynamic, thermal and dissolved-oxygen model was developed and calibrated for Beaver Lake, Arkansas. The model simulates surface-water elevation, currents, heat transport and dissolved-oxygen dynamics. The model was developed to assess the impacts of proposed increases in minimum flows from 1.76 cubic meters per second (the existing minimum flow) to 3.85 cubic meters per second (the additional minimum flow). Simulations included assessing (1) the impact of additional minimum flows on tailwater temperature and dissolved-oxygen quality and (2) increasing initial water-surface elevation 0.5 meter and assessing the impact of additional minimum flow on tailwater temperatures and dissolved-oxygen concentrations. The additional minimum flow simulation (without increasing initial pool elevation) appeared to increase the water temperature (<0.9 degrees Celsius) and decrease dissolved oxygen concentration (<2.2 milligrams per liter) in the outflow discharge. Conversely, the additional minimum flow plus initial increase in pool elevation (0.5 meter) simulation appeared to decrease outflow water temperature (0.5 degrees Celsius) and increase dissolved oxygen concentration (<1.2 milligrams per liter) through time. However, results from both minimum flow scenarios for both water temperature and dissolved oxygen concentration were within the boundaries or similar to the error between measured and simulated water column profile values.

Occurrence of benzotriazoles in the rivers Main, Hengstbach, and Hegbach (Germany).

PubMed

Kiss, Aliz; Fries, Elke

2009-09-01

Benzotriazoles (BT) as 1H-benzotriazole (1H-BT), 5-methyl-1H-benzotriazole (5Me-BT), and 4-methyl-1H-benzotriazole (4Me-BT) are frequently used as corrosion inhibitors in dish washer detergents, aircraft de-icing/anti-icing fluids (ADAF), automotive antifreeze formulations, brake fluids, fluids for industrial cooling systems, metal-cutting fluids, and in solid cooling lubricants. Discharge of treated municipal waste water and controlled over-runs of combined waste water sewers are potential point sources for BT in rivers. The aim of this monitoring study was to yield an overview on exposure concentrations and loads of BT in the German rivers Main, Hengstbach, and Hegbach. Concentrations of 1H-BT, 5Me-BT, and 4Me-BT were determined in grab samples collected from different sampling points in the rivers Main, Hengstbach, and Hegbach at four different sampling times. Main and Hengstbach rivers were sampled close to Frankfurt International Airport. Both rivers receive domestic waste water effluents. BT were extracted from 2.5 L of river water by solid phase extraction using Bond Elut ppl cartridges (200 mg/3 mL). The extracts were analyzed by gas chromatography/mass spectrometry in full scan mode. Mass flows of BT were calculated by concentrations multiplied by mean daily river flow rates. Median concentrations and mass flows were compared for different rivers. Mass flows were also compared for selected sampling points at different sampling times. 1H-BT, 5Me-BT, and 4Me-BT were detected in Main and Hengstbach rivers. 1H-BT and 5Me-BT were also detected in Hegbach River. Concentrations ranged from 38 to 1,474 ng/L for 1H-BT, from 25 to 281 ng/L for 5Me-BT, and from 25 to 952 ng/L for 4Me-BT. Median concentrations of 1H-BT, 5Me-BT, and 4Me-BT were lower in Main than in Hengstbach River. Much higher median mass flows of all BT were calculated for Main than for Hengstbach River. At sampling points P9 (Main) and P5 (Hengstbach) concentrations of 4Me-BT and 5Me-BT increased from March 29, 2008 to May 1, 2008 to June 22, 2008 whereas daily mean river flow rate decreased simultaneously. However, concentration of 1H-BT in Main and Hengstbach River increased from March 29, 2008 to May 1, 2008 and decreased again on June 22, 2008. In the Main River, lowest and highest mass flows for all BT were calculated on June 22, 2008 and May 1, 2008, respectively. In the Hengstbach River lowest and highest mass flows for 1H-BT and 4Me-BT were also calculated on June 22, 2008 and May 1, 2008, respectively. However, mass flows of 5Me-BT in Hengstbach River were rather similar at all three sampling times. In all grab samples, 1H-BT was more abundant than 5Me-BT and 4Me-BT in Main and Hengstbach River, except on June 22, 2008. Ratios of 1H-BT/(5Me-BT + 4Me-BT) determined on March 15, 2008, March 29, 2008, and May 1, 2008 varied between 1.6 and 9.0 with a median value of 1.9 (n = 9) whereas on June 22, 2008 the ratios varied between 0.4 and 0.7 with a median value of 0.6 (n = 5). Due to the absence of waste water effluents in the Hegbach River, other input sources as controlled over-runs of combined waste water sewers and/or atmospheric deposition of BT must be regarded as possible input sources. Exfiltration of ground water containing BT to Hegbach River must be also regarded, especially when considering the high polarity of BT. Median concentrations of BT in Main River were much lower than in Hengstbach River due to dilution. However, median mass flows were higher in the Main River than in the Hengstbach River. Higher mass flows could be attributed to higher source strengths and/or numerous emissions sources in the Main River. Mass flows determined on June 22, 2008 in Main and Hengstbach rivers probably reflect emissions of BT only from dishwasher detergents since de-icing operations were unlikely at that time. Emissions of BT from dish washer detergents are rather constant without any seasonal variations. Assuming the absence of additional input sources and constant in-stream removal processes, mass flows calculated for all other sampling times must be nearly similar to mass flows for June 22, 2009 as it was only observed for 5Me-BT in Hengstbach River. The higher mass flows for 1H-BT and 4Me-BT in March and May in both rivers could be an indication for temporal variations of emission pattern and/or of in-stream removal processes. 1H-BT/(4Me-BT + 5Me-BT) ratios above one in March and May and below one in June could be also an indication for temporal variations of input and/or removal processes. 1H-BT, 5Me-BT, and 4Me-BT used as corrosion inhibitors in many applications were detected in the rivers Main, Hengstbach, and Hegbach with relative high temporal and spatial concentration variations. Dilution is a dominant factor that influences exposure concentrations of BT in the studied rivers. We conclude that, especially in smaller rivers (as Hengstbach River), the hydrological situation has to be regarded when predicting exposure concentrations of BT. Characteristic emission strength and in-stream removal processes must be known to relate loads of BT in river water to different sources. The ratio of 1H-BT/(4Me-BT + 5Me-BT) could be possibly used for source apportionment. Time series analyses of BT in composite river water samples collected at two river sites of the Hengstbach/Schwarzbach catchment area, without any waste water effluents in between, are recommended to study in-stream removal of BT. In addition, exposure modeling is recommended of BT, regarding all input sources and in-stream removal processes to predict exposure concentrations of BT in rivers. In order to calibrate and validate the model, additional monitoring data are required.

Assessing the potential of reservoir outflow management to reduce sedimentation using continuous turbidity monitoring and reservoir modelling

USGS Publications Warehouse

Lee, Casey; Foster, Guy

2013-01-01

In-stream sensors are increasingly deployed as part of ambient water quality-monitoring networks. Temporally dense data from these networks can be used to better understand the transport of constituents through streams, lakes or reservoirs. Data from existing, continuously recording in-stream flow and water quality monitoring stations were coupled with the two-dimensional hydrodynamic CE-QUAL-W2 model to assess the potential of altered reservoir outflow management to reduce sediment trapping in John Redmond Reservoir, located in east-central Kansas. Monitoring stations upstream and downstream from the reservoir were used to estimate 5.6 million metric tons of sediment transported to John Redmond Reservoir from 2007 through 2010, 88% of which was trapped within the reservoir. The two-dimensional model was used to estimate the residence time of 55 equal-volume releases from the reservoir; sediment trapping for these releases varied from 48% to 97%. Smaller trapping efficiencies were observed when the reservoir was maintained near the normal operating capacity (relative to higher flood pool levels) and when average residence times were relatively short. An idealized, alternative outflow management scenario was constructed, which minimized reservoir elevations and the length of time water was in the reservoir, while continuing to meet downstream flood control end points identified in the reservoir water control manual. The alternative scenario is projected to reduce sediment trapping in the reservoir by approximately 3%, preventing approximately 45 000 metric tons of sediment from being deposited within the reservoir annually. This article presents an approach to quantify the potential of reservoir management using existing in-stream data; actual management decisions need to consider the effects on other reservoir benefits, such as downstream flood control and aquatic life.

Climate Change Impacts on Sediment Transport In a Lowland Watershed System: Controlling Processes and Projection

NASA Astrophysics Data System (ADS)

al Aamery, N. M. H.; Mahoney, D. T.; Fox, J.

2017-12-01

Future climate change projections suggest extreme impacts on watershed hydrologic systems for some regions of the world including pronounced increases in surface runoff and instream flows. Yet, there remains a lack of research focused on how future changes in hydrologic extremes, as well as relative hydrologic mean changes, impact sediment redistribution within a watershed and sediment flux from a watershed. The authors hypothesized that variations in mean and extreme changes in turn may impact sediments in depositional and erosional dominance in a manner that may not be obvious to the watershed manager. Therefore, the objectives of this study were to investigate the inner processes connecting the combined effect of extreme climate change projections on the vegetation, upland erosion, and instream processes to produce changes in sediment redistribution within watersheds. To do so, research methods were carried out by the authors including simulating sediment processes in forecast and hindcast periods for a lowland watershed system. Publically available climate realizations from several climate factors and the Soil Water Assessment Tool (SWAT) were used to predict hydrologic conditions for the South Elkhorn Watershed in central Kentucky, USA to 2050. The results of the simulated extreme and mean hydrological components were used in simulating upland erosion with the connectivity processes consideration and thereafter used in building and simulating the instream erosion and deposition of sediment processes with the consideration of surface fine grain lamina (SFGL) layer controlling the benthic ecosystem. Results are used to suggest the dominance of erosional and depositional redistribution of sediments under different scenarios associated with extreme and mean hydrologic forecasting. The results are discussed in reference to the benthic ecology of the stream system providing insight on how water managers might consider sediment redistribution in a changing climate.

Conducting a FERC environmental assessment: a case study and recommendations from the Terror Lake Project

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

Olive, S.W.; Lamb, B.L.

This paper is an account of the process that evolved during acquisition of the license to operate the Terror Lake hydroelectric power project under the auspices of the Federal Energy Regulatory Commission (FERC). The Commission is responsible for granting these licenses under the Federal Power Act (16 U.S.C. 792 et seq.). This act provides, in part, that FERC may condition a license to protect the public interest. The public interest in these cases has come to include both instream and terrestrial values. The Terror River is located on Kodiak Island in Alaska. The river is within the Kodiak National Wildlifemore » Refuge; it supports excellent runs of several species of Pacific Salmon which are both commercially important and a prime source of nutrition for the Kodiak brown bear. The river is also a prime resource for generating electric power. One major concern in the negotiations was the impact of land disturbance and management practices on brown bear habitat - i.e., protection of the brown bear. Maintenance of the bears' habitat is the main purpose of the Kodiak National Wildlife Refuge. But, like many other projects, resolving the instream flow issue was of major importance in the issuance of the FERC license. This paper discusses the fish and wildlife questions, but concentrates on instream uses and how protection of these uses was decided. With this as a focus, the paper explains the FERC process, gives a history of the Terror Lake Project, and, ultimately, makes recommendations for improved management of controversies within the context of the FERC licensing procedures. 65 references.« less

Occurrence and in-stream attenuation of wastewater-derived pharmaceuticals in Iberian rivers.

PubMed

Acuña, Vicenç; von Schiller, Daniel; García-Galán, Maria Jesús; Rodríguez-Mozaz, Sara; Corominas, Lluís; Petrovic, Mira; Poch, Manel; Barceló, Damià; Sabater, Sergi

2015-01-15

A multitude of pharmaceuticals enter surface waters via discharges of wastewater treatment plants (WWTPs), and many raise environmental and health concerns. Chemical fate models predict their concentrations using estimates of mass loading, dilution and in-stream attenuation. However, current comprehension of the attenuation rates remains a limiting factor for predictive models. We assessed in-stream attenuation of 75 pharmaceuticals in 4 river segments, aiming to characterize in-stream attenuation variability among different pharmaceutical compounds, as well as among river segments differing in environmental conditions. Our study revealed that in-stream attenuation was highly variable among pharmaceuticals and river segments and that none of the considered pharmaceutical physicochemical and molecular properties proved to be relevant in determining the mean attenuation rates. Instead, the octanol-water partition coefficient (Kow) influenced the variability of rates among river segments, likely due to its effect on sorption to sediments and suspended particles, and therefore influencing the balance between the different attenuation mechanisms (biotransformation, photolysis, sorption, and volatilization). The magnitude of the measured attenuation rates urges scientists to consider them as important as dilution when aiming to predict concentrations in freshwater ecosystems. Copyright © 2014 Elsevier B.V. All rights reserved.

Routing Algorithm based on Minimum Spanning Tree and Minimum Cost Flow for Hybrid Wireless-optical Broadband Access Network

NASA Astrophysics Data System (ADS)

Le, Zichun; Suo, Kaihua; Fu, Minglei; Jiang, Ling; Dong, Wen

2012-03-01

In order to minimize the average end to end delay for data transporting in hybrid wireless optical broadband access network, a novel routing algorithm named MSTMCF (minimum spanning tree and minimum cost flow) is devised. The routing problem is described as a minimum spanning tree and minimum cost flow model and corresponding algorithm procedures are given. To verify the effectiveness of MSTMCF algorithm, extensively simulations based on OWNS have been done under different types of traffic source.

Analytical and experimental validation of the Oblique Detonation Wave Engine concept

NASA Technical Reports Server (NTRS)

Adelman, Henry G.; Cambier, Jean-Luc; Menees, Gene P.; Balboni, John A.

1988-01-01

The Oblique Detonation Wave Engine (ODWE) for hypersonic flight has been analytically studied by NASA using the CFD codes which fully couple finite rate chemistry with fluid dynamics. Fuel injector designs investigated included wall and strut injectors, and the in-stream strut injectors were chosen to provide good mixing with minimal stagnation pressure losses. Plans for experimentally validating the ODWE concept in an arc-jet hypersonic wind tunnel are discussed. Measurements of the flow field properties behind the oblique wave will be compared to analytical predictions.

The minimum or natural rate of flow and droplet size ejected by Taylor cone-jets: physical symmetries and scaling laws

NASA Astrophysics Data System (ADS)

Gañán-Calvo, A. M.; Rebollo-Muñoz, N.; Montanero, J. M.

2013-03-01

We aim to establish the scaling laws for both the minimum rate of flow attainable in the steady cone-jet mode of electrospray, and the size of the resulting droplets in that limit. Use is made of a small body of literature on Taylor cone-jets reporting precise measurements of the transported electric current and droplet size as a function of the liquid properties and flow rate. The projection of the data onto an appropriate non-dimensional parameter space maps a region bounded by the minimum rate of flow attainable in the steady state. To explain these experimental results, we propose a theoretical model based on the generalized concept of physical symmetry, stemming from the system time invariance (steadiness). A group of symmetries rising at the cone-to-jet geometrical transition determines the scaling for the minimum flow rate and related variables. If the flow rate is decreased below that minimum value, those symmetries break down, which leads to dripping. We find that the system exhibits two instability mechanisms depending on the nature of the forces arising against the flow: one dominated by viscosity and the other by the liquid polarity. In the former case, full charge relaxation is guaranteed down to the minimum flow rate, while in the latter the instability condition becomes equivalent to the symmetry breakdown by charge relaxation or separation. When cone-jets are formed without artificially imposing a flow rate, a microjet is issued quasi-steadily. The flow rate naturally ejected this way coincides with the minimum flow rate studied here. This natural flow rate determines the minimum droplet size that can be steadily produced by any electrohydrodynamic means for a given set of liquid properties.

Normal injection of helium from swept struts into ducted supersonic flow

NASA Technical Reports Server (NTRS)

Mcclinton, C. R.; Torrence, M. G.

1975-01-01

Recent design studies have shown that airframe-integrated scramjets should include instream mounted, swept-back strut fuel injectors to obtain short combustors. Because there was no data in the literature on mixing characteristics of swept strut fuel injectors, the present investigation was undertaken to provide such data. This investigation was made with two swept struts in a closed duct at Mach number of 4.4 and nominal jet-to-air mass flow ratio of 0.029 with helium used to simulate hydrogen fuel. The data is compared with flat plate mounted normal injector data to obtain the effect of swept struts on mixing. Three injector patterns were evaluated representing the range of hole spacing and jet-to-freestream dynamic pressure ratio of interest. Measured helium concentration, pitot pressure, and static pressure in the downstream mixing region are used to generate contour plots necessary to define the mixing region flow field and the mixing parameters.

Simulations of a hypothetical temperature control structure at Detroit Dam on the North Santiam River, northwestern Oregon

USGS Publications Warehouse

Buccola, Norman L.; Stonewall, Adam J.; Rounds, Stewart A.

2015-01-01

Estimated egg-emergence days for endangered Upper Willamette River Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River winter steelhead (Oncorhynchus mykiss) were assessed for all scenarios. Estimated spring Chinook fry emergence under SlidingWeir scenarios was 9 days later immediately downstream of Big Cliff Dam, and 4 days later at Greens Bridge compared with existing structural scenarios at Detroit Dam. Despite the inclusion of a hypothetical sliding weir at Detroit Dam, temperatures exceeded without-dams temperatures during November and December. These late-autumn exceedances likely represent the residual thermal effect of Detroit Lake operated to meet minimum dry-season release rates (supporting instream habitat and irrigation requirements) and lake levels specified by the current (2014) operating rules (supporting recreation and flood mitigation).

Population Viability Analysis of Riverine Fishes

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

Bates, P.; Chandler, J.; Jager, H.I.

Many utilities face conflkts between two goals: cost-efficient hydropower generation and protecting riverine fishes. Research to develop ecological simulation tools that can evaluate alternative mitigation strategies in terms of their benefits to fish populations is vital to informed decision-making. In this paper, we describe our approach to population viability analysis of riverine fishes in general and Snake River white sturgeon in particular. We are finding that the individual-based modeling approach used in previous in-stream flow applications is well suited to addressing questions about the viability of species of concern for several reasons. Chief among these are: (1) the abiIity tomore » represent the effects of individual variation in life history characteristics on predicted population viabili~, (2) the flexibili~ needed to quanti~ the ecological benefits of alternative flow management options by representing spatial and temporal variation in flow and temperaturty and (3) the flexibility needed to quantifi the ecological benefits of non-flow related manipulations (i.e., passage, screening and hatchery supplementation).« less

Simulation of hydrodynamics, temperature, and dissolved oxygen in Table Rock Lake, Missouri, 1996-1997

USGS Publications Warehouse

Green, W. Reed; Galloway, Joel M.; Richards, Joseph M.; Wesolowski, Edwin A.

2003-01-01

Outflow from Table Rock Lake and other White River reservoirs support a cold-water trout fishery of substantial economic yield in south-central Missouri and north-central Arkansas. The Missouri Department of Conservation has requested an increase in existing minimum flows through the Table Rock Lake Dam from the U.S. Army Corps of Engineers to increase the quality of fishable waters downstream in Lake Taneycomo. Information is needed to assess the effect of increased minimum flows on temperature and dissolved- oxygen concentrations of reservoir water and the outflow. A two-dimensional, laterally averaged, hydrodynamic, temperature, and dissolved-oxygen model, CE-QUAL-W2, was developed and calibrated for Table Rock Lake, located in Missouri, north of the Arkansas-Missouri State line. The model simulates water-surface elevation, heat transport, and dissolved-oxygen dynamics. The model was developed to assess the effects of proposed increases in minimum flow from about 4.4 cubic meters per second (the existing minimum flow) to 11.3 cubic meters per second (the increased minimum flow). Simulations included assessing the effect of (1) increased minimum flows and (2) increased minimum flows with increased water-surface elevations in Table Rock Lake, on outflow temperatures and dissolved-oxygen concentrations. In both minimum flow scenarios, water temperature appeared to stay the same or increase slightly (less than 0.37 ?C) and dissolved oxygen appeared to decrease slightly (less than 0.78 mg/L) in the outflow during the thermal stratification season. However, differences between the minimum flow scenarios for water temperature and dissolved- oxygen concentration and the calibrated model were similar to the differences between measured and simulated water-column profile values.

A framework for modeling anthropogenic impacts on waterbird habitats: addressing future uncertainty in conservation planning

USGS Publications Warehouse

Matchett, Elliott L.; Fleskes, Joseph P.; Young, Charles A.; Purkey, David R.

2015-01-01

The amount and quality of natural resources available for terrestrial and aquatic wildlife habitats are expected to decrease throughout the world in areas that are intensively managed for urban and agricultural uses. Changes in climate and management of increasingly limited water supplies may further impact water resources essential for sustaining habitats. In this report, we document adapting a Water Evaluation and Planning (WEAP) system model for the Central Valley of California. We demonstrate using this adapted model (WEAP-CVwh) to evaluate impacts produced from plausible future scenarios on agricultural and wetland habitats used by waterbirds and other wildlife. Processed output from WEAP-CVwh indicated varying levels of impact caused by projected climate, urbanization, and water supply management in scenarios used to exemplify this approach. Among scenarios, the NCAR-CCSM3 A2 climate projection had a greater impact than the CNRM-CM3 B1 climate projection, whereas expansive urbanization had a greater impact than strategic urbanization, on annual availability of waterbird habitat. Scenarios including extensive rice-idling or substantial instream flow requirements on important water supply sources produced large impacts on annual availability of waterbird habitat. In the year corresponding with the greatest habitat reduction for each scenario, the scenario including instream flow requirements resulted in the greatest decrease in habitats throughout all months of the wintering period relative to other scenarios. This approach provides a new and useful tool for habitat conservation planning in the Central Valley and a model to guide similar research investigations aiming to inform conservation, management, and restoration of important wildlife habitats.

In-Stream Sediment Dynamics for predicted environmental concentration calculations of plant protection products in the FOCUSSW Scenarios

NASA Astrophysics Data System (ADS)

Strehmel, Alexander; Erzgräber, Beate; Gottesbüren, Bernhard

2016-04-01

The exposure assessment for the EU registration procedure of plant protection products (PPP), which is based on the 'Forum for the co-ordination of pesticide fate models and their use' (FOCUS), currently considers only periods of 12-16 months for the exposure assessment in surface water bodies. However, in a recent scientific opinion of the European Food Safety Authority (EFSA) it is argued that in a multi-year exposure assessment, the accumulation of PPP substances in river sediment may be a relevant process. Therefore, the EFSA proposed to introduce a sediment accumulation factor in order to account for enrichment of PPP substances over several years in the sediment. The calculation of this accumulation factor, however, would consider degradation in sediment as the only dissipation path, and does not take into account riverine sediment dynamics. In order to assess the influence of deposition and the possible extent of substance accumulation in the sediment phase, the hydraulic model HEC-RAS was employed for an assessment of in-stream sediment dynamics of the FOCUS stream scenarios. The model was parameterized according to the stream characteristics of the FOCUS scenarios and was run over a period of 20 years. The results show that with the distribution of grain sizes and the ranges of flow velocity in the FOCUS streams the main sediment process in the streams is transport. First modeling results suggest that about 80% of the eroded sediment mass from the adjacent field are transported to the downstream end of the stream and out of the system, while only about 20% are deposited in the river bed. At the same time, only about 30% of in-stream sediment mass stems from the adjacent field and is associated with PPP substance, while the remaining sediment consists of the substance-free base sediment concentration regarded in the scenarios. With this, the hydraulic modelling approach is able to support the development of a meaningful sediment accumulation factor by considering in-stream sediment dynamics and estimating long-term sediment deposition and substance burial in the river bed. At last, the study shows that the development of a scientifically sound and justifiable sediment accumulation factor for a long-term exposure assessment is only possible by considering the relevant riverine sediment processes.

75 FR 30388 - Natural Currents Energy Services, LLC; Notice of Preliminary Permit Application Accepted for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-01

... operate in-stream tidal turbines to power the office building and marina on site. Natural Currents Red... of the tides. The initial installations would consist of ten in-stream 20-kilowatt (kW) turbines with...

Modeling Multi-Reservoir Hydropower Systems in the Sierra Nevada with Environmental Requirements and Climate Warming

NASA Astrophysics Data System (ADS)

Rheinheimer, David Emmanuel

Hydropower systems and other river regulation often harm instream ecosystems, partly by altering the natural flow and temperature regimes that ecosystems have historically depended on. These effects are compounded at regional scales. As hydropower and ecosystems are increasingly valued globally due to growing values for clean energy and native species as well as and new threats from climate warming, it is important to understand how climate warming might affect these systems, to identify tradeoffs between different water uses for different climate conditions, and to identify promising water management solutions. This research uses traditional simulation and optimization to explore these issues in California's upper west slope Sierra Nevada mountains. The Sierra Nevada provides most of the water for California's vast water supply system, supporting high-elevation hydropower generation, ecosystems, recreation, and some local municipal and agricultural water supply along the way. However, regional climate warming is expected to reduce snowmelt and shift runoff to earlier in the year, affecting all water uses. This dissertation begins by reviewing important literature related to the broader motivations of this study, including river regulation, freshwater conservation, and climate change. It then describes three substantial studies. First, a weekly time step water resources management model spanning the Feather River watershed in the north to the Kern River watershed in the south is developed. The model, which uses the Water Evaluation And Planning System (WEAP), includes reservoirs, run-of-river hydropower, variable head hydropower, water supply demand, and instream flow requirements. The model is applied with a runoff dataset that considers regional air temperature increases of 0, 2, 4 and 6 °C to represent historical, near-term, mid-term and far-term (end-of-century) warming. Most major hydropower turbine flows are simulated well. Reservoir storage is also generally well simulated, mostly limited by the accuracy of inflow hydrology. System-wide hydropower generation is reduced by 9% with 6 °C warming. Most reductions in hydropower generation occur in the highly productive watersheds in the northern Sierra Nevada. The central Sierra Nevada sees less reduction in annual runoff and can adapt better to changes in runoff timing. Generation in southern watersheds is expected to decrease. System-wide, reservoirs adapt to capture earlier runoff, but mostly decrease in mean reservoir storage with warming due to decreasing annual runoff. Second, a multi-reservoir optimization model is developed using linear programming that considers the minimum instream flows (MIFs) and weekly down ramp rates (DRRs) in the Upper Yuba River in the northern Sierra Nevada. Weekly DRR constraints are used to mimic spring snowmelt flows, which are particularly important for downstream ecosystems in the Sierra Nevada but are currently missing due to the influence of dams. Trade-offs between MIFs, DRRs and hydropower are explored with air temperature warming (+0, 2, 4 and 6 °C). Under base case operations, mean annual hydropower generation increases slightly with 2 °C warming and decreases slightly with 6 °C warming. With 6 °C warming, the most ecologically beneficial MIF and DRR reduce hydropower generation 5.5% compared to base case operations and a historical climate, which has important implications for re-licensing the hydropower project. Finally, reservoir management for downstream temperatures is explored using a linear programming model to optimally release water from a reservoir using selective withdrawal. The objective function is to minimize deviations from desired downstream temperatures, which are specified to mimic the natural temperature regime in the river. One objective of this study was to develop a method that can be readily integrated into a basin-scale multi-reservoir optimization model using a network representation of system features. The second objective was to explore the potential use of reservoirs to maintain an ideal stream temperature regime to ameliorate the temperature effects of climate warming of air temperature. For proof-of-concept, the model is applied to Lake Spaulding in the Upper Yuba River. With selective withdrawal, the model hedges the release of cold water to decrease summer stream temperatures, but at a cost of warmer stream temperatures in the winter. Results also show that selective withdrawal can reduce, but not eliminate, the temperature effects of climate warming. The model can be extended to include other nearby reservoirs to optimally manage releases from multiple reservoirs for multiple downstream temperature targets in a highly interconnected system. While the outcomes of these studies contribute to our understanding of reservoir management and hydropower at the intersection of energy, water management, ecosystems, and climate warming, there are many opportunities to improve this work. Promising options for improving and building on the collective utility of these studies are presented.

In-stream wetlands and their significance for channel filling and the catchment sediment budget, Jugiong Creek, New South Wales

NASA Astrophysics Data System (ADS)

Zierholz, C.; Prosser, I. P.; Fogarty, P. J.; Rustomji, P.

2001-06-01

Evidence is presented here of recent and extensive infilling of the incised channel network of the Jugiong Creek catchment, SE Australia. The present channel network resulted from widespread stream and gully incision in the period between 1880 and 1920. Our survey shows that gully floors have been colonised extensively by emergent macrophyte vegetation since before 1944, forming continuous, dense, in-stream wetlands, which now cover 25% of the channel network in the 2175 km 2 catchment and have so far trapped almost 2,000,000 t of nutrient-enriched, fine sediments. This mass of sediments represents the equivalent of 4.7 years of annual sediment production across the catchment and in some tributaries, more than 20 years of annual yield is stored within in-stream wetlands. Previous work on the late Quaternary stratigraphy of the region has shown that there were repeated phases of channel incision in the past following which the channels quickly stabilised by natural means and then filled with fine-grained sediment to the point of channel extinction, creating unchannelled swampy valley floors. The current formation and spread of in-stream wetlands is interpreted to be the onset of the next infill phase but it is not known whether present conditions will allow complete channel filling and reformation of the pre-existing swampy valley floors. Nevertheless, further spread of in-stream wetlands is likely to increase the sediment trapping capacity and further reduce the discharge of sediments and nutrients into the Murrumbidgee River. The in-stream wetlands may provide a significant capacity to buffer erosion from gullied catchments of considerable size (up to 300 km 2) as an adjunct to current riparian management options. They may also assist the recovery of sediment-impacted channels downstream.

Integrated modeling approach using SELECT and SWAT models to simulate source loading and in-stream conditions of fecal indicator bacteria.

NASA Astrophysics Data System (ADS)

Ranatunga, T.

2016-12-01

Modeling of fate and transport of fecal bacteria in a watershed is generally a processed based approach that considers releases from manure, point sources, and septic systems. Overland transport with water and sediments, infiltration into soils, transport in the vadose zone and groundwater, die-off and growth processes, and in-stream transport are considered as the other major processes in bacteria simulation. This presentation will discuss a simulation of fecal indicator bacteria (E.coli) source loading and in-stream conditions of a non-tidal watershed (Cedar Bayou Watershed) in South Central Texas using two models; Spatially Explicit Load Enrichment Calculation Tool (SELECT) and Soil and Water Assessment Tool (SWAT). Furthermore, it will discuss a probable approach of bacteria source load reduction in order to meet the water quality standards in the streams. The selected watershed is listed as having levels of fecal indicator bacteria that posed a risk for contact recreation and wading by the Texas Commission of Environmental Quality (TCEQ). The SELECT modeling approach was used in estimating the bacteria source loading from land categories. Major bacteria sources considered were, failing septic systems, discharges from wastewater treatment facilities, excreta from livestock (Cattle, Horses, Sheep and Goat), excreta from Wildlife (Feral Hogs, and Deer), Pet waste (mainly from Dogs), and runoff from urban surfaces. The estimated source loads were input to the SWAT model in order to simulate the transport through the land and in-stream conditions. The calibrated SWAT model was then used to estimate the indicator bacteria in-stream concentrations for future years based on H-GAC's regional land use, population and household projections (up to 2040). Based on the in-stream reductions required to meet the water quality standards, the corresponding required source load reductions were estimated.

Exploring the impact of agriculture on nitrogen and phosphorus biogeochemistry in global rivers during the twentieth century (Invited)

NASA Astrophysics Data System (ADS)

Bouwman, L.; Beusen, A.; Van Beek, L. P.

2013-12-01

Nutrients are transported from land to sea through the continuum formed by soils, groundwater, riparian zones, floodplains, streams, rivers, lakes, and reservoirs. The hydrology, ecology and biogeochemical processing in each of these components are strongly coupled and result in retention of a significant fraction of the nutrients transported. This paper analyzes the global changes in nutrient biogeochemical processes and retention in rivers during the past century (1900-2000); this period encompasses dramatic increases in human population and economic human activities including agriculture that have resulted in major changes in land use, nutrient use in agriculture, wastewater flows and human interventions in the hydrology (1). We use the hydrological PCR-GLOBWB model (2) for the period 1900-2000, including climate variability and the history of dam construction and land use conversion. Global agricultural and natural N and P soil budgets for the period 1900-2000 are the starting point to simulate nutrient flows from the soil via surface runoff and leaching through the groundwater system and riparian zones. In-stream processes are described with the nutrient spiraling concept. In the period 1900-2000, the global soil N budget surplus (inputs minus withdrawal in harvested crops) for agricultural and natural ecosystems increased from 118 to 202 Tg yr-1, and the global P budget increased from < 0.5 to 11 Tg P yr-1. As a result of this massive increase, nutrient delivery to streams and river nutrient export has increased rapidly in the 20th century. Model results are sensitive to factors determining the N and P delivery, as well as in-stream processes. The most uncertain factors are N delivery to streams by groundwater (denitrification as a function of thickness and reactivity of aquifers), and in-stream N and P retention parameters (net uptake velocity, retention as function of concentration). References 1. Bouwman AF, Beusen AHW, Griffioen J, Van Groenigen JW, Hefting MM, Oenema O, et al. Global trends and uncertainties in terrestrial denitrification and N2O emissions. Philosophical Transactions of the Royal Society B: Biological Sciences. 2013;368(20130112). 2. Van Beek LPH, Wada Y, Bierkens MFP. Global monthly water stress: 1. Water balance and water availability. Water Resour Res. 2011;47(7):W07517.

EVALUATION OF STREAMBANK RESTORATION ON IN-STREAM WATER QUALITY IN AN URBAN WATERSHED

EPA Science Inventory

The objectives of this on-going project are to: investigate the effectiveness of streambank restoration techniques on increasing available biological habitat and improving in-stream water quality in an impaired stream; and, demonstrate the utility of continuous water-quality moni...

Evaluation of water quality, suspended sediment, and stream morphology with an emphasis on effects of stormwater on Fountain and Monument Creek basins, Colorado Springs and vicinity, Colorado, 1981-2001

USGS Publications Warehouse

Edelmann, Patrick; Ferguson, Sheryl A.; Stogner, Sr., Robert W.; August, Marianne; Payne, William F.; Bruce, James F.

2002-01-01

This report documents water quality and suspended sediment with an emphasis on evaluating the effects of stormflow on Fountain Creek Basin in the vicinity of Colorado Springs, Colorado. Water-quality data collected at 11 sites between 1981 and 2001 were used to evaluate the effects of stormflow on water quality. Suspended-sediment data collected at seven sites from 1998 through 2001 were used to evaluate effects of stormflow on suspended-sediment concentrations, discharges, and yields. Data were separated into three flow regimes: base flow, normal flow, and stormflow. A comparison of stormwater-quality concentrations measured between 1981 and 2001 to Colorado acute instream standards indicated that, except for isolated occurrences, stormwater quality met acute instream standards. At several sites, 5-day biochemical oxygen demand, fecal coliform, and selected nutrient concentrations tended to be highest during stormflow and lowest during base flow. Dissimilar to the other nutrients, dissolved nitrite plus nitrate concentrations generally were highest during base flow and lowest during stormflow. Most dissolved trace-element concentrations associated with stormflow decreased or showed little change compared to base flow. However, median concentrations of total copper, iron, lead, nickel, manganese, and zinc for stormflow samples generally were much larger than nonstorm samples. The substantially larger concentrations of total copper, iron, lead, nickel, manganese, and zinc measured at site 5800 during stormflow as compared to other sites indicates a relatively large source of these metals in the reach between sites 5530 and 5800. Semi-volatile organic compounds in samples collected during stormflow were detected relatively infrequently at the four sites monitored; however, analysis of pesticide data collected during stormflow showed a relatively frequent detection of pesticides at low levels. Nitrogen, phosphorus, and particulate trace-element loads substantially increased during stormflow. Suspended-sediment concentrations, discharges, and yields associated with stormflow were significantly greater than during normal flow. Depending on the site and year, suspended-sediment concentrations associated with storm-flow generally were 3 to10 times greater than concentrations measured during normal flow, and suspended-sediment discharges were usually more than 10 times greater during stormflow. The April through October cumulative suspended-sediment discharges and streamflows were largest in 1999 at all sites. Although large spatial variations in suspended-sediment yields occurred during normal flows, the suspended-sediment yields associated with stormflow generally were more than 10 times greater than the suspended-sediment yields that occurred during normal flow. The smallest suspended-sediment yields generally were less than 1 ton per day per square mile during stormflow. The largest suspended-sediment yields occurred at sites located in the Cottonwood Creek Basin and were greater than 10 tons per day per square mile.

Projected increases in the annual flood pulse of the Western Amazon

NASA Astrophysics Data System (ADS)

Zulkafli, Zed; Buytaert, Wouter; Manz, Bastian; Véliz Rosas, Claudia; Willems, Patrick; Lavado-Casimiro, Waldo; Guyot, Jean-Loup; Santini, William

2016-01-01

The impact of a changing climate on the Amazon basin is a subject of intensive research because of its rich biodiversity and the significant role of rainforests in carbon cycling. Climate change has also a direct hydrological impact, and increasing efforts have focused on understanding the hydrological dynamics at continental and subregional scales, such as the Western Amazon. New projections from the Coupled Model Inter-comparison Project Phase 5 ensemble indicate consistent climatic warming and increasing seasonality of precipitation in the Peruvian Amazon basin. Here we use a distributed land surface model to quantify the potential impact of this change in the climate on the hydrological regime of the upper Amazon river. Using extreme value analysis, historical and future projections of the annual minimum, mean, and maximum river flows are produced for a range of return periods between 1 and 100 yr. We show that the RCP 4.5 and 8.5 scenarios of climate change project an increased severity of the wet season flood pulse (7.5% and 12% increases respectively for the 100 yr return floods). These findings agree with previously projected increases in high extremes under the Special Report on Emissions Scenarios climate projections, and are important to highlight due to the potential consequences on reproductive processes of in-stream species, swamp forest ecology, and socio-economy in the floodplain, amidst a growing literature that more strongly emphasises future droughts and their impact on the viability of the rainforest system over greater Amazonia.

Determination of the effects of fine-grained sediment and other limiting variables on trout habitat for selected streams in Wisconsin

USGS Publications Warehouse

Scudder, Barbara C.; Selbig, J.W.; Waschbusch, R.J.

2000-01-01

Two Habitat Suitability Index (HSI) models, developed by the U.S. Fish and Wildlife Service, were used to evaluate the effects of fine-grained (less than 2 millimeters) sediment on brook trout (Salvelinusfontinalis, Mitchill) and brown trout (Salmo trutta, Linnaeus) in 11 streams in west-central and southwestern Wisconsin. Our results indicated that fine-grained sediment limited brook trout habitat in 8 of 11 streams and brown trout habitat in only one stream. Lack of winter and escape cover for fry was the primary limiting variable for brown trout at 61 percent of the sites, and this factor also limited brook trout at several stations. Pool area or quality, in stream cover, streambank vegetation for erosion control, minimum flow, thalweg depth maximum, water temperature, spawning substrate, riffle dominant substrate, and dissolved oxygen also were limiting to trout in the study streams. Brook trout appeared to be more sensitive to the effects of fine-grained sediment than brown trout. The models for brook trout and brown trout appeared to be useful and objective screening tools for identifying variables limiting trout habitat in these streams. The models predicted that reduction in the amount of fine-grained sediment would improve brook trout habitat. These models may be valuable for establishing instream sediment-reduction goals; however, the decrease in sediment delivery needed to meet these goals cannot be estimated without quantitative data on land use practices and their effects on sediment delivery and retention by streams.

Instream Large Wood: Dentrification Hotspots With Low N2O Production

EPA Science Inventory

The maintenance and restoration of forested riparian cover is important for watershed nitrogen (N) cycling. Forested riparian zones provide woody debris to streams that may stimulate in-stream denitrification and nitrous oxide (N2O) production. We examined the effects of woody an...

EFFECTS OF STREAM RESTORATION ON IN-STREAM WATER QUALITY IN AN URBAN WATERSHED

EPA Science Inventory

The purpose of this on-going project is to provide information to Municipal Separate Storm Sewer System (MS4s) operators and states on the performance of selected best management practices (BMPs), specifically, stream restoration techniques, on improving biological and in-stream ...

Streamflow and water quality of the Grand Calumet River, Lake County, Indiana, and Cook County, Illinois, October 1984

USGS Publications Warehouse

Crawford, Charles G.; Wangsness, David J.

1987-01-01

A diel (24-hour) water-quality survey was done to investigate the sources of dry-weather waste inputs attributable to other than permitted point-source effluent and to evaluate the waste-load assimilative capacity of the Grand Calumet River, Lake County, Indiana, and Cook County, Illinois, in October 1984. Flow in the Grand Calumet River consists almost entirely of municipal and industrial effluents which comprised more than 90% of the 500 cu ft/sec flow observed at the confluence of the East Branch Grand Calumet River and the Indiana Harbor Ship Canal during the study. At the time of the study, virtually all of the flow in the West Branch Grand Calumet River was municipal effluent. Diel variations in streamflow of as much as 300 cu ft/sec were observed in the East Branch near the ship canal. The diel variation diminished at the upstream sampling sites in the East Branch. In the West Branch, the diel variation in flow was quite drastic; complete reversals of flow were observed at sampling stations near the ship canal. Average dissolved-oxygen concentrations at stations in the East Branch ranged from 5.7 to 8.2 mg/L and at stations in the West Branch from 0.8 to 6.6 mg/L. Concentrations of dissolved solids, suspended solids, biochemical-oxygen demand, ammonia, nitrite, nitrate, and phosphorus were substantially higher in the West Branch than in the East Branch. In the East Branch, only the Indiana Stream Pollution Control Board water-quality standards for total phosphorus and phenol were exceeded. In the West Branch, water-quality standards for total ammonia, chloride, cyanide, dissolved solids, fluoride, total phosphorus, mercury, and phenol were exceeded and dissolved oxygen was less than the minimum allowable. Three areas of significant differences between cumulative effluent and instream chemical-mass discharges were identified in the East Branch and one in the West Branch. The presence of unidentified waste inputs in the East Branch were indicated by differences in the chemical-mass discharges at three sites. Elevated suspended solids, biochemical-oxygen demand, and ammonia chemical-mass discharges at Columbia Avenue indicated the presence of a source of what may have been untreated sewage to the West Branch during the survey. (Author 's abstract)

Fuel control for gas turbine with continuous pilot flame

DOEpatents

Swick, Robert M.

1983-01-01

An improved fuel control for a gas turbine engine having a continuous pilot flame and a fuel distribution system including a pump drawing fuel from a source and supplying a line to the main fuel nozzle of the engine, the improvement being a control loop between the pump outlet and the pump inlet to bypass fuel, an electronically controlled throttle valve to restrict flow in the control loop when main nozzle demand exists and to permit substantially unrestricted flow without main nozzle demand, a minimum flow valve in the control loop downstream of the throttle valve to maintain a minimum pressure in the loop ahead of the flow valve, a branch tube from the pilot flame nozzle to the control loop between the throttle valve and the minimum flow valve, an orifice in the branch tube, and a feedback tube from the branch tube downstream of the orifice to the minimum flow valve, the minimum flow valve being operative to maintain a substantially constant pressure differential across the orifice to maintain constant fuel flow to the pilot flame nozzle.

Habitat Suitability Index Models: Yellow perch

USGS Publications Warehouse

Krieger, Douglas A.; Terrell, James W.; Nelson, Patrick C.

1983-01-01

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for yellow perch (Perca flavescens). The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for riverine, lacustrine, and palustrine habitat in the 48 contiguous United States. Habitat Suitability Indexes (HSI's) are designed for use with the Habitat Evaluation Procedures developed by the U.S. Fish and Wildlife Service. Also included are discussions of Suitability Index (SI) curves as used in the Instream Flow Incremental Methodology (IFIM) and SI curves available for an IFIM analysis of yellow perch habitat.

SETTING EXPECTATIONS FOR THE OHIO RIVER FISH INDEX BASED ON IN-STREAM HABITAT

EPA Science Inventory

The use of habitat criteria for setting fish community assessment expectations is common for streams, but a standard approach for great rivers remains largely undeveloped. We developed assessment expectations for the Ohio River Fish Index (ORFIN) based on measures of in-stream h...

Influence of instream habitat and water quality on aggressive behavior in crayfish of channelized headwater streams

USDA-ARS?s Scientific Manuscript database

Many agricultural drainage ditches that border farm fields of the Midwestern United States are degraded headwater streams that possess communities of crayfish. We hypothesized that crayfish communities at sites with low instream habitat diversity and poor water quality would show greater evidence of...

75 FR 40797 - Upper Peninsula Power Company; Notice of Application for Temporary Amendment of License and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-14

... for drought-based temporary variance of the reservoir elevations and minimum flow releases at the Dead... temporary variance to the reservoir elevation and minimum flow requirements at the Hoist Development. The...: (1) Releasing a minimum flow of 75 cubic feet per second (cfs) from the Hoist Reservoir, instead of...

Water quality in the Mahoning River and selected tributaries in Youngstown, Ohio

USGS Publications Warehouse

Stoeckel, Donald M.; Covert, S. Alex

2002-01-01

The lower reaches of the Mahoning River in Youngstown, Ohio, have been characterized by the Ohio Environmental Protection Agency (OEPA) as historically having poor water quality. Most wastewater-treatment plants (WWTPs) in the watershed did not provide secondary sewage treatment until the late 1980s. By the late 1990s, the Mahoning River still received sewer-overflow discharges from 101 locations within the city of Youngstown, Ohio. The Mahoning River in Youngstown and Mill Creek, a principal tributary to the Mahoning River in Youngstown, have not met biotic index criteria since the earliest published assessment by OEPA in 1980. Youngstown and the OEPA are working together toward the goal of meeting water-quality standards in the Mahoning River. The U.S. Geological Survey collected information to help both parties assess water quality in the area of Youngstown and to estimate bacteria and inorganic nitrogen contributions from sewer-overflow discharges to the Mahoning River. Two monitoring networks were established in the lower Mahoning River: the first to evaluate hydrology and microbiological and chemical water quality and the second to assess indices of fish and aquatic-macroinvertebrate-community health. Water samples and water-quality data were collected from May through October 1999 and 2000 to evaluate where, when, and for how long water quality was affected by sewer-overflow discharges. Water samples were collected during dry- and wet-weather flow, and biotic indices were assessed during the first year (1999). The second year of sample collection (2000) was directed toward evaluating changes in water quality during wet-weather flow, and specifically toward assessing the effect of sewer-overflow discharges on water quality in the monitoring network. Water-quality standards for Escherichia coli (E. coli) concentration and draft criteria for nitrate plus nitrite and total phosphorus were the regulations most commonly exceeded in the Mahoning River and Mill Creek sampling networks. E. coli concentrations increased during wet-weather flow and remained higher than dry-weather concentrations for 48 hours after peak flow. E. coli concentration criteria were more commonly exceeded during wet-weather flow than during dry-weather flow. Exceedances of nutrient-concentration criteria were not substantially more common during wet-weather flow. The fish and aquatic macroinvertebrate network included Mill Creek and its tributaries but did not include the main stem of the Mahoning River. Persistent exceedances of chemical water-quality standards in Mill Creek and the presence of nutrient concentrations in excess of draft criteria may have contributed to biotic index scores that on only one occasion met State criteria throughout the fish and aquatic macroinvertebrate sampling network. Monitored tributary streams did not contribute concentrations of E. coli, nitrate plus nitrite, or total phosphorus to the Mahoning River and Mill Creek that were higher than main-stem concentrations, but monitored WWTP and sewer-overflow discharges did contribute. Twenty-four hour load estimates of sewer-overflow discharge contributions during wet-weather flow indicated that sewer-overflow discharges contributed large loads of bacteria and inorganic nitrogen to the Mahoning River relative to the instream load. The sewer-overflow loads appeared to move as a slug of highly enriched water that passed through Youngstown on the rising limb of the storm hydrograph. The median estimated sewer-overflow load contribution of bacteria was greater than the estimated instream load by a factor of five or more; however, the median estimated sewer-overflow load of inorganic nitrogen was less than half of the estimated instream load. Sewer-overflow discharges contributed loads of E. coli and nutrients to the Mahoning River and Mill Creek at a point where the streams already did not meet State water-quality regulations. Improvement of water quality of

Flow variations and macroinvertebrate community responses in a small groundwater-dominated stream in south east England

USGS Publications Warehouse

Bendix, J.; Hupp, C.R.

2000-01-01

Changes in the macroinvertebrate community in response to flow variations in the Little Stour River, Kent, UK, were examined over a 6 year period (1992-1997). This period included the final year of the 1988-1992 drought, followed by some of the wettest conditions recorded this century and a second period of drought between 1996 and 1997. Each year, samples were collected from 15 sites during late-summer base-flow conditions. Correspondence analysis identified clear differences between samples from upstream and downstream sites, and between drought and non-drought years. Step-wise multiple regression was used to identify hydrological indicators of community variation. Several different indices were used to describe the macroinvertebrate community, including macroinvertebrate community abundance, number of families and species, and individual species. Site characteristics were fundamental in accounting for variation in the unstandardized macroinvertebrate community. However, when differences between sites were controlled, hydrological conditions were found to play a dominant role in explaining ecological variation. Indices of high discharge (or their absence), 4-7 months prior to sampling (i.e. winter-spring), were found to be the most important variables for describing the late-summer community The results are discussed in relation to the role of flow variability in shaping instream communities and management implications. Copyright ?? 2000 John Wiley & Sons, Ltd.Changes in the macroinvertebrate community in response to flow variations in the Little Stour River, Kent, UK, were examined over a 6 year period (1992-1997). This period included the final year of the 1988-1992 drought, followed by some of the wettest conditions recorded this century and a second period of drought between 1996 and 1997. Each year, samples were collected from 15 sites during late-summer base-flow conditions. Correspondence analysis identified clear differences between samples from upstream and downstream sites, and between drought and non-drought years. Step-wise multiple regression was used to identify hydrological indicators of community variation. Several different indices were used to describe the macroinvertebrate community, including macroinvertebrate community abundance, number of families and species, and individual species. Site characteristics were fundamental in accounting for variation in the unstandardized macroinvertebrate community. However, when differences between sites were controlled, hydrological conditions were found to play a dominant role in explaining ecological variation. Indices of high discharge (or their absence), 4-7 months prior to sampling (i.e. winter-spring), were found to be the most important variables for describing the late-summer community. The results are discussed in relation to the role of flow variability in shaping instream communities and management implications.

Coupled hydrological and biogeochemical processes controlling variability of nitrogen species in streamflow during autumn in an upland forest

USGS Publications Warehouse

Sebestyen, Stephen D.; Shanley, James B.; Boyer, Elizabeth W.; Kendall, Carol; Doctor, Daniel H.

2014-01-01

Autumn is a season of dynamic change in forest streams of the northeastern United States due to effects of leaf fall on both hydrology and biogeochemistry. Few studies have explored how interactions of biogeochemical transformations, various nitrogen sources, and catchment flow paths affect stream nitrogen variation during autumn. To provide more information on this critical period, we studied (1) the timing, duration, and magnitude of changes to stream nitrate, dissolved organic nitrogen (DON), and ammonium concentrations; (2) changes in nitrate sources and cycling; and (3) source areas of the landscape that most influence stream nitrogen. We collected samples at higher temporal resolution for a longer duration than typical studies of stream nitrogen during autumn. This sampling scheme encompassed the patterns and extremes that occurred during base flow and stormflow events of autumn. Base flow nitrate concentrations decreased by an order of magnitude from 5.4 to 0.7 µmol L−1 during the week when most leaves fell from deciduous trees. Changes to rates of biogeochemical transformations during autumn base flow explained the low nitrate concentrations; in-stream transformations retained up to 72% of the nitrate that entered a stream reach. A decrease of in-stream nitrification coupled with heterotrophic nitrate cycling were primary factors in the seasonal nitrate decline. The period of low nitrate concentrations ended with a storm event in which stream nitrate concentrations increased by 25-fold. In the ensuing weeks, peak stormflow nitrate concentrations progressively decreased over closely spaced, yet similarly sized events. Most stormflow nitrate originated from nitrification in near-stream areas with occasional, large inputs of unprocessed atmospheric nitrate, which has rarely been reported for nonsnowmelt events. A maximum input of 33% unprocessed atmospheric nitrate to the stream occurred during one event. Large inputs of unprocessed atmospheric nitrate show direct and rapid effects on forest streams that may be widespread, although undocumented, throughout nitrogen-polluted temperate forests. In contrast to a week-long nitrate decline during peak autumn litterfall, base flow DON concentrations increased after leaf fall and remained high for 2 months. Dissolved organic nitrogen was hydrologically flushed to the stream from riparian soils during stormflow. In contrast to distinct seasonal changes in base flow nitrate and DON concentrations, ammonium concentrations were typically at or below the detection limit, similar to the rest of the year. Our findings reveal couplings among catchment flow paths, nutrient sources, and transformations that control seasonal extremes of stream nitrogen in forested landscapes.

Flows for floodplain forests: a successful riparian restoration

USGS Publications Warehouse

Rood, Stewart B.; Gourley, Chad R.; Ammon, Elisabeth M.; Heki, Lisa G.; Klotz, Jonathan R.; Morrison, Michael L.; Mosley, Dan; Scoppettone, Gayton G.; Swanson, Sherman; Wagner, Paul L.

2003-01-01

Throughout the 20th century, the Truckee River that flows from Lake Tahoe into the Nevada desert was progressively dammed and dewatered, which led to the collapse of its aquatic and riparian ecosystems. The federal designation of the endemic cui-ui sucker (Chasmistes cujus) as endangered prompted a restoration program in the 1980s aimed at increasing spring flows to permit fish spawning. These flows did promote cui-ui reproduction, as well as an unanticipated benefit, the extensive seedling recruitment of Fremont cottonwood (Populus fremontii) and sandbar willow (Salix exigua). Recruitment was scattered in 1983 but extensive in 1987, when the hydrograph satisfied the riparian recruitment box model that had been developed for other rivers. That model was subsequently applied to develop flow prescriptions that were implemented from 1995 through 2000 and enabled further seedling establishment. The woodland recovery produced broad ecosystem benefits, as evidenced by the return by 1998 of 10 of 19 riparian bird species whose populations had been locally extirpated or had declined severely between 1868 and 1980. The dramatic partial recovery along this severely degraded desert river offers promise that the use of instream flow regulation can promote ecosystem restoration along other dammed rivers worldwide.

Assessing the Vulnerability of Streams to Increased Frequency and Severity of Low Flows in the Southeastern United States

NASA Astrophysics Data System (ADS)

Konrad, C. P.

2014-12-01

A changing climate poses risks to the availability and quality of water resources. Among the risks, increased frequency and severity of low flow periods in streams would be significant for many in-stream and out-of-stream uses of water. While down-scaled climate projections serve as the basis for understanding impacts of climate change on hydrologic systems, a robust framework for risk assessment incorporates multiple dimensions of risks including the vulnerability of hydrologic systems to climate change impacts. Streamflow records from the southeastern US were examined to assess the vulnerability of streams to increased frequency and severity of low flows. Long-term (>50 years) records provide evidence of more frequent and severe low flows in more streams than would be expected from random chance. Trends in low flows appear to be a result of changes in the temporal distribution rather than the annual amount of preciptation and/or in evaporation. Base flow recession provides an indicator of a stream's vulnerability to such changes. Linkages between streamflow patterns across temporal scales can be used for understanding and asessing stream responses to the various possible expressions of a changing climate.

Biotic Drivers of Spatial Heterogeneity and Implications for River Ecosystems

NASA Astrophysics Data System (ADS)

Wohl, Ellen

2017-04-01

Rivers throughout the northern hemisphere have been simplified and homogenized by the removal of beavers and instream wood, along with numerous forms of channel engineering and flow regulation. Loss of spatial heterogeneity in river corridors - channels and floodplains - affects downstream fluxes of water, sediment, organic matter, and nutrients, as well as stream metabolism, biomass, and biodiversity. Recent work in streams of the Colorado Rocky Mountains illustrates how the presence of beavers and instream wood can facilitate spatial heterogeneity by creating stable, persistent, multithread channel planform and high channel-floodplain and channel-hyporheic zone connectivity. This spatial heterogeneity facilitates retention of water in pools, floodplain wetlands, and hyporheic storage. Suspended sediment, particulate organic matter (POM), and solutes are also more likely to be retained in these stream segments than in more uniform stream segments with greater downstream conveyance. Retention of POM and solutes equates to greater volumes of organic carbon storage per unit valley length and greater rates of nitrogen uptake. Spatially heterogeneous stream segments also exhibit greater biomass and biodiversity of aquatic macroinvertebrates, salmonid fish, and riparian spiders than do more uniform stream segments. These significant differences in stream form and function are unlikely to be unique to this field area and can provide a conceptual model for understanding and restoring ecosystem functions in other rivers.

Sea lamprey orient toward a source of a synthesized pheromone using odor-conditioned rheotaxis

USGS Publications Warehouse

Johnson, Nicholas S.; Muhammad, Azizah; Thompson, Henry; Choi, Jongeun; Li, Weiming

2012-01-01

Characterization of vertebrate chemo-orientation strategies over long distances is difficult because it is often not feasible to conduct highly controlled hypothesis-based experiments in natural environments. To overcome the challenge, we couple in-stream behavioral observations of female sea lampreys (Petromyzon marinus) orienting to plumes of a synthesized mating pheromone, 7a,12a,24-trihydroxy-5a-cholan-3-one-24-sulfate (3kPZS), and engineering algorithms to systematically test chemo-orientation hypotheses. In-stream field observations and simulated movements of female sea lampreys according to control algorithms support that odor-conditioned rheotaxis is a component of the mechanism used to track plumes of 3kPZS over hundreds of meters in flowing water. Simulated movements of female sea lampreys do not support that rheotaxis or klinotaxis alone is sufficient to enable the movement patterns displayed by females in locating 3kPZS sources in the experimental stream. Odor-conditioned rheotaxis may not only be effective at small spatial scales as previous described in crustaceans, but may also be effectively used by fishes over hundreds of meters. These results may prove useful for developing management strategies for the control of invasive species that exploit the odor-conditioned tracking behavior and for developing biologically inspired navigation strategies for robotic fish.

Microbial Source Module (MSM): Documenting the Science ...

EPA Pesticide Factsheets

The Microbial Source Module (MSM) estimates microbial loading rates to land surfaces from non-point sources, and to streams from point sources for each subwatershed within a watershed. A subwatershed, the smallest modeling unit, represents the common basis for information consumed and produced by the MSM which is based on the HSPF (Bicknell et al., 1997) Bacterial Indicator Tool (EPA, 2013b, 2013c). Non-point sources include numbers, locations, and shedding rates of domestic agricultural animals (dairy and beef cows, swine, poultry, etc.) and wildlife (deer, duck, raccoon, etc.). Monthly maximum microbial storage and accumulation rates on the land surface, adjusted for die-off, are computed over an entire season for four land-use types (cropland, pasture, forest, and urbanized/mixed-use) for each subwatershed. Monthly point source microbial loadings to instream locations (i.e., stream segments that drain individual sub-watersheds) are combined and determined for septic systems, direct instream shedding by cattle, and POTWs/WWTPs (Publicly Owned Treatment Works/Wastewater Treatment Plants). The MSM functions within a larger modeling system that characterizes human-health risk resulting from ingestion of water contaminated with pathogens. The loading estimates produced by the MSM are input to the HSPF model that simulates flow and microbial fate/transport within a watershed. Microbial counts within recreational waters are then input to the MRA-IT model (Soller et

Temporal and spatial variability in North Carolina piedmont stream temperature

Treesearch

J.L. Boggs; G. Sun; S.G. McNulty; W. Swartley; Treasure E.; W. Summer

2009-01-01

Understanding temporal and spatial patterns of in-stream temperature can provide useful information to managing future impacts of climate change on these systems. This study will compare temporal patterns and spatial variability of headwater in-stream temperature in six catchments in the piedmont of North Carolina in two different geological regions, Carolina slate...

Large in-stream wood studies: A call for common metrics

Treesearch

Ellen Wohl; Daniel A. Cenderelli; Kathleen A. Dwire; Sandra E. Ryan-Burkett; Michael K. Young; Kurt D. Fausch

2010-01-01

During the past decade, research on large in-stream wood has expanded beyond North America's Pacific Northwest to diverse environments and has shifted toward increasingly holistic perspectives that incorporate processes of wood recruitment, retention, and loss at scales from channel segments to entire watersheds. Syntheses of this rapidly expanding literature can...

Stream temperature response to three riparian vegetation scenarios by use of a distributed temperature validated model.

PubMed

Roth, T R; Westhoff, M C; Huwald, H; Huff, J A; Rubin, J F; Barrenetxea, G; Vetterli, M; Parriaux, A; Selkeer, J S; Parlange, M B

2010-03-15

Elevated in-stream temperature has led to a surge in the occurrence of parasitic intrusion proliferative kidney disease and has resulted in fish kills throughout Switzerland's waterways. Data from distributed temperature sensing (DTS) in-stream measurements for three cloud-free days in August 2007 over a 1260 m stretch of the Boiron de Merges River in southwest Switzerland were used to calibrate and validate a physically based one-dimensional stream temperature model. Stream temperature response to three distinct riparian conditions were then modeled: open, in-stream reeds, and forest cover. Simulation predicted a mean peak stream temperature increase of 0.7 °C if current vegetation was removed, an increase of 0.1 °C if dense reeds covered the entire stream reach, and a decrease of 1.2 °C if a mature riparian forest covered the entire reach. Understanding that full vegetation canopy cover is the optimal riparian management option for limiting stream temperature, in-stream reeds, which require no riparian set-aside and grow very quickly, appear to provide substantial thermal control, potentially useful for land-use management.

High levels of endocrine pollutants in US streams during low flow due to insufficient wastewater dilution

NASA Astrophysics Data System (ADS)

Rice, Jacelyn; Westerhoff, Paul

2017-08-01

Wastewater discharges from publicly owned treatment works are a significant source of endocrine disruptors and other contaminants to the aquatic environment in the US. Although remaining pollutants in wastewater pose environmental risks, treated wastewater is also a primary source of stream flow, which in turn is critical in maintaining many aquatic and riparian wildlife habitats. Here we calculate the dilution factor--the ratio of flow in the stream receiving discharge to the flow of wastewater discharge--for over 14,000 receiving streams in the continental US using streamflow observations and a spatially explicit watershed-scale hydraulic model. We found that wastewater discharges make up more than 50% of in-stream flow for over 900 streams. However, in 1,049 streams that experienced exceptional low-flow conditions, the dilution factors in 635 of those streams fell so low during those conditions that the safety threshold for concentrations of one endocrine disrupting compound was exceeded, and in roughly a third of those streams, the threshold was exceeded for two compounds. We suggest that streams are vulnerable to public wastewater discharge of contaminants under low-flow conditions, at a time when wastewater discharges are likely to be most important for maintaining stream flow for smaller sized river systems.

Determination of habitat requirements for Apache Trout

USGS Publications Warehouse

Petre, Sally J.; Bonar, Scott A.

2017-01-01

The Apache Trout Oncorhynchus apache, a salmonid endemic to east-central Arizona, is currently listed as threatened under the U.S. Endangered Species Act. Establishing and maintaining recovery streams for Apache Trout and other endemic species requires determination of their specific habitat requirements. We built upon previous studies of Apache Trout habitat by defining both stream-specific and generalized optimal and suitable ranges of habitat criteria in three streams located in the White Mountains of Arizona. Habitat criteria were measured at the time thought to be most limiting to juvenile and adult life stages, the summer base flow period. Based on the combined results from three streams, we found that Apache Trout use relatively deep (optimal range = 0.15–0.32 m; suitable range = 0.032–0.470 m) pools with slow stream velocities (suitable range = 0.00–0.22 m/s), gravel or smaller substrate (suitable range = 0.13–2.0 [Wentworth scale]), overhead cover (suitable range = 26–88%), and instream cover (large woody debris and undercut banks were occupied at higher rates than other instream cover types). Fish were captured at cool to moderate temperatures (suitable range = 10.4–21.1°C) in streams with relatively low maximum seasonal temperatures (optimal range = 20.1–22.9°C; suitable range = 17.1–25.9°C). Multiple logistic regression generally confirmed the importance of these variables for predicting the presence of Apache Trout. All measured variables except mean velocity were significant predictors in our model. Understanding habitat needs is necessary in managing for persistence, recolonization, and recruitment of Apache Trout. Management strategies such as fencing areas to restrict ungulate use and grazing and planting native riparian vegetation might favor Apache Trout persistence and recolonization by providing overhead cover and large woody debris to form pools and instream cover, shading streams and lowering temperatures.

Compliance of the Savannah River Site D-Area cooling system with environmental regulations

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

Specht, W.L.; Mackey, H.E.; Paller, M.H.

1990-08-01

This document presents information relating to a demonstration under Section 316(a) of the Clean Water Act for the 400-D Area cooling system at the Savannah River Site (SRS) near Aiken, South Carolina. The demonstration was mandated because the National Pollution Discharge Elimination System (NPDES) permit for SRS (SC0000175), granted on January 1, 1984, specified in-stream temperature limits in SRS streams of 32.2{degree}C and a {Delta}T limit of 2.8{degree}C above ambient. To achieve compliance with in-stream temperature limits, the Department of Energy (DOE) and the South Carolina Department of Health and Environmental Control (SCDHEC) entered into a Consent Order (84-4-W) whichmore » temporarily superseded the temperature requirements and identified a process for attaining compliance. The preferred option for achieving thermal compliance in Beaver Dam Creek consisted of increased flow, with mixing of the raw water basin overflow with the cooling water discharge during the summer months. Although this action can achieve instream temperatures of less than 32.2{degree}C, {Delta}T's still exceed 2.8{degree}C. Therefore, a 316 (a) Demonstration was initiated to determine whether a balanced indigenous biological community can be supported in the receiving stream with {Delta}T's in excess of 2.8{degree}C. A Biological Monitoring Program for Beaver Dam Creek was approved by SCDHEC in June 1988 and implemented in September 1988. The program monitored the water quality, habitat formers, zooplankton, macroinvertebrates, fish, other vertebrate wildlife and threatened and endangered species in Beaver Dam Creek for an 18-month period (September 1988-February 1990). This document summarizes information collected during the monitoring program and evaluates the data to determine whether Beaver Dam Creek presently supports a balanced indigenous biological community. 97 refs., 32 figs., 51 tabs.« less

The importance of the riparian zone and in-stream processes in nitrate attenuation in undisturbed and agricultural watersheds – a review of the scientific literature

USGS Publications Warehouse

Ranalli, Anthony J.; Macalady, Donald L.

2010-01-01

We reviewed published studies from primarily glaciated regions in the United States, Canada, and Europe of the (1) transport of nitrate from terrestrial ecosystems to aquatic ecosystems, (2) attenuation of nitrate in the riparian zone of undisturbed and agricultural watersheds, (3) processes contributing to nitrate attenuation in riparian zones, (4) variation in the attenuation of nitrate in the riparian zone, and (5) importance of in-stream and hyporheic processes for nitrate attenuation in the stream channel. Our objectives were to synthesize the results of these studies and suggest methodologies to (1) monitor regional trends in nitrate concentration in undisturbed 1st order watersheds and (2) reduce nitrate loads in streams draining agricultural watersheds. Our review reveals that undisturbed headwater watersheds have been shown to be very retentive of nitrogen, but the importance of biogeochemical and hydrological riparian zone processes in retaining nitrogen in these watersheds has not been demonstrated as it has for agricultural watersheds. An understanding of the role of the riparian zone in nitrate attenuation in undisturbed watersheds is crucial because these watersheds are increasingly subject to stressors, such as changes in land use and climate, wildfire, and increases in atmospheric nitrogen deposition. In general, understanding processes controlling the concentration and flux of nitrate is critical to identifying and mapping the vulnerability of watersheds to water quality changes due to a variety of stressors. In undisturbed and agricultural watersheds we propose that understanding the importance of riparian zone processes in 2nd order and larger watersheds is critical. Research is needed that addresses the relative importance of how the following sources of nitrate along any given stream reach might change as watersheds increase in size and with flow: (1) inputs upstream from the reach, (2) tributary inflow, (3) water derived from the riparian zone, (4) groundwater from outside the riparian zone (intermediate or regional sources), and (5) in-stream (hyporheic) processes.

The effect of in-stream activities on the Njoro River, Kenya. Part II: Microbial water quality

NASA Astrophysics Data System (ADS)

Yillia, Paul T.; Kreuzinger, Norbert; Mathooko, Jude M.

The influence of periodic in-stream activities of people and livestock on the microbial water quality of the Njoro River in Kenya was monitored at two disturbed pools (Turkana Flats and Njoro Bridge) at the middle reaches. A total of 96 sets of samples were obtained from the two pools in six weeks during dry weather (January-April) in 2006. On each sampling day, two trips were made before and during in-stream activities and on each trip, two sets of samples were collected upstream and downstream of activities. This schedule was repeated four times each for Wednesday, Saturday and Sunday. Samples were processed for heterotrophic plate count bacteria (HPC), total coliform (TC), presumptive Escherichia coli and presumptive Enterococci. Additional samples were analysed for total suspended solids (TSS), turbidity, BOD 5 and ammonium-N. The microbial water quality deteriorated significant ( p < 0.05) downstream during activities at both pools. A similar trend was observed with the chemical indicators (TSS, turbidity, BOD 5 and ammonium-N). The two groups of indicators demonstrated high capacity for site segregation based on pollution levels. Pollution levels for specific days were not significantly different ( p > 0.05). This was incompatible with the variability of in-stream activities with specific days. The pooled data was explained largely by three significant principal components - recent pollution (PC1), metabolic activity (PC2) and residual pollution (PC3). It was concluded that the empirical site parity/disparity in the levels of microbial and non-microbial indicators reflected the diurnal periodicity of in-stream activities and the concomitant pollution they caused. However, microbial source tracking studies are required to distinguish faecal sources. In the meantime, measures should be undertaken to regulate in-stream activities along the stream and minimize the movement of livestock in the catchment.

Vortex generation and mixing in three-dimensional supersonic combustors

NASA Technical Reports Server (NTRS)

Riggins, D. W.; Vitt, P. H.

1993-01-01

The generation and evolution of the flow vorticity established by instream injector ramps in a high Mach number/high enthalpy scramjet combustor flow-field are described in detail for a number of computational cases. Classical fluid dynamic circulation is presented for these cases in order to clarify the spatial distribution and convection of the vorticity. The ability of the simulations to accurately represent Stokes Law of circulation is discussed and shown. In addition, the conservation of swirl (effectively the moment-of-momentum theorem) is presented for these flows. The impact of both turbulent diffusion and the vortex/ramp non-uniformity on the downstream mixing rate is clearly illustrated. A correlation over the length of the combustor between fuel-air mixing and a parameter called the vortex stirring length is demonstrated. Finally, computational results for a representative ramp injector are compared with experimental data. Influence of the stream vorticity on the effective turbulent Prandtl number used in the simulation is discussed.

The NASA Langley Isolator Dynamics Research Lab

NASA Technical Reports Server (NTRS)

Middleton, Troy F.; Balla, Robert J.; Baurle, Robert A.; Humphreys, William M.; Wilson, Lloyd G.

2010-01-01

The Isolator Dynamics Research Lab (IDRL) is under construction at the NASA Langley Research Center in Hampton, Virginia. A unique test apparatus is being fabricated to support both wall and in-stream measurements for investigating the internal flow of a dual-mode scramjet isolator model. The test section is 24 inches long with a 1-inch by 2-inch cross sectional area and is supplied with unheated, dry air through a Mach 2.5 converging-diverging nozzle. The test section is being fabricated with two sets (glass and metallic) of interchangeable sidewalls to support flow visualization and laser-based measurement techniques as well as static pressure, wall temperature, and high frequency pressure measurements. During 2010, a CFD code validation experiment will be conducted in the lab in support of NASA s Fundamental Aerodynamics Program. This paper describes the mechanical design of the Isolator Dynamics Research Lab test apparatus and presents a summary of the measurement techniques planned for investigating the internal flow field of a scramjet isolator model.

Minimum flow unit installation at the South Edwards Hydro Plant

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

Bernhardt, P.; Bates, D.

1995-12-31

Niagara Mohawk Power Corp. owns and operates the 3.3 MW South Edwards Hydro Plant in Northern New York. The FERC license for this plant requires a minimum flow release in the bypass region of the river. NMPC submitted a license amendment to the FERC to permit the addition of a minimum flow unit to take advantage of this flow. The amendment was accepted, permitting the installation of the 236 kw, 60 cfs unit to proceed. The unit was installed and commissioned in 1994.

Relations of surface-water quality to streamflow in the Raritan River basin, New Jersey, water years 1976-93

USGS Publications Warehouse

Buxton, Debra E.; Hunchak-Kariouk, Kathryn; Hickman, R. Edward

1999-01-01

Relations of water quality to streamflow were determined for 18 water-quality constituents at 21 surface-water stations within the drainage area of the Raritan River Basin for water years 1976-93. Surface-water-quality and streamflow data were evaluated for trends (through time) in constituent concentrations during high and low flows, and relations between constituent concentration and streamflow, and between constituent load and streamflow, were determined. Median concentrations were calculated for the entire period of study (water years 1976-93) and for the last 5 years of the period of study (water years 1989-93) to determine whether any large variation in concentration exists between the two periods. Medians also were used to determine the seasonal Kendall’s tau statistic, which was then used to evaluate trends in concentrations during high and low flows. Trends in constituent concentrations during high and low flows were evaluated to determine whether the distribution of the observations changes through time for intermittent (nonpoint storm runoff) or constant (point sources and ground water) sources, respectively. Highand low-flow trends in concentrations were determined for some constituents at 13 of the 21 water-quality stations; 8 stations have insufficient data to determine trends. Seasonal effects on the relations of concentration to streamflow are evident for 16 of the 18 constituents. Negative slopes of relations of concentration to streamflow, which indicate a decrease in concentration at high flows, predominate over positive slopes because of the dilution of instream concentrations by storm runoff. The slopes of the regression lines of load to streamflow were determined in order to show the relative contributions to the instream load from constant (point sources and ground water) and intermittent sources (storm runoff). Greater slope values indicate larger contributions from storm runoff to instream load, which most likely indicate an increased relative importance of nonpoint sources. The slopes of load-to-streamflow relations along a stream reach that tend to increase in a downstream direction indicate the increased relative importance of contributions from storm runoff. The slopes of load-to-streamflow relations increase in the downstream direction for alkalinity at North Branch Raritan and Millstone Rivers, for some or all of the nutrient species at South Branch and North Branch Raritan Rivers, for hardness at South Branch Raritan River, for dissolved solids at North Branch Raritan River, for dissolved sodium at Lamington River, and for suspended sediment and dissolved oxygen at Millstone River. Likewise, the slopes of load-tostreamflow relations along a stream reach that tend to decrease in a downstream direction indicate the increased relative importance of point sources and ground-water discharge. The slopes of load-to-streamflow relations decrease in the downstream direction for dissolved solids at Raritan and Millstone Rivers; for dissolved sodium, dissolved chloride, total ammonia plus organic nitrogen, and total ammonia at South Branch Raritan, Raritan, and Millstone Rivers; for dissolved oxygen at North Branch Raritan and Lamington Rivers; for total nitrite at Lamington, Raritan, and Millstone Rivers; for total boron at South Branch Raritan and Millstone Rivers; for total organic carbon at North Branch Raritan River; for suspended sediment and total nitrogen at Raritan River; and for hardness, total phosphorus, and total lead at Millstone River.

Explaining spatial variability in stream habitats using both natural and management-influenced landscape predictors

Treesearch

K.J. Anlauf; D.W. Jensen; K.M. Burnett; E.A. Steel; K. Christiansen; J.C. Firman; B.E. Feist; D.P. Larsen

2011-01-01

1. The distribution and composition of in-stream habitats are reflections of landscape scale geomorphic and climatic controls. Correspondingly, Pacific salmon (Oncorhynchus spp.) are largely adapted to and constrained by the quality and complexity of those in-stream habitat conditions. The degree to which lands have been fragmented and managed can...

Estimated water withdrawals and use in Pennsylvania, 1995

USGS Publications Warehouse

Ludlow, Russell A.; Gast, William A.

2000-01-01

In practical terms, water use is divided into two basic types: instream use and offstream use. Instream use is water used in its natural channel, basin, or behind a dam and includes activities such as fishing, boating, and other recreational activities. Instream use also includes hydroelectric power generation. Off-stream use is water pumped or diverted from its natural channel, basin, or aquifer. Off-stream uses are divided into the following categories: public supply, domestic, commercial, industrial, thermoelectric power, mining, livestock, and irrigation. This fact sheet provides an overview of offstream and hydroelectric power water use in Pennsylvania. It describes water withdrawals by source, water withdrawals and deliveries by category, changes in water use over time, and water-management responsibilities in the State.

Anomalies in Trace Metal and Rare-Earth Loads below a Waste-Water Treatment Plant

NASA Astrophysics Data System (ADS)

Antweiler, R.; Writer, J. H.; Murphy, S.

2013-12-01

The changes in chemical loads were examined for 54 inorganic elements and compounds in a 5.4-km reach of Boulder Creek, Colorado downstream of a waste water treatment plant (WWTP) outfall. Elements were partitioned into three categories: those showing a decrease in loading downstream, those showing an increase, and those which were conservative, at least over the length of the study reach. Dissolved loads which declined - generally indicative of in-stream loss via precipitation or sorption - were typically rapid (occurring largely before the first sampling site, 2.3 km downstream); elements showing this behavior were Bi, Cr, Cs, Ga, Ge, Hg, Se and Sn. These results were as expected before the experiment was performed. However, a large group (28 elements, including all the rare-earth elements, REE, except Gd) exhibited dissolved load increases indicating in-stream gains. These gains may be due to particulate matter dissolving or disaggregating, or that desorption is occurring below the WWTP. As with the in-stream loss group, the processes tended to be rapid, typically occurring before the first sampling site. Whole-water samples collected concurrently also had a large group of elements which showed an increase in load downstream of the WWTP. Among these were most of the group which had increases in the dissolved load, including all the REE (except Gd). Because whole-water samples include both dissolved and suspended particulates within them, increases in loads cannot be accounted for by invoking desorption or disaggregation mechanisms; thus, the only source for these increases is from the bed load of the stream. Further, the difference between the whole-water and dissolved loads is a measure of the particulate load, and calculations show that not only did the dissolved and whole-water loads increase, but so did the particulate loads. This implies that at the time of sampling the bed sediment was supplying a significant contribution to the suspended load. In general, it seems untenable as a hypothesis to suppose that the stream bed material can permanently supply the source of the in-stream load increases of a large group of inorganic elements. We propose that the anomalous increase in loads was more a function of the time of sampling (both diurnally and seasonally) and that sampling at different times of day or different seasons during the year would give contradictory results to those seen here. If this is so, inorganic loading studies must include multiple sampling both over the course of a day and during different seasons and flow regimes.

Low-flow characteristics of streams in Ohio through water year 1997

USGS Publications Warehouse

Straub, David E.

2001-01-01

This report presents selected low-flow and flow-duration characteristics for 386 sites throughout Ohio. These sites include 195 long-term continuous-record stations with streamflow data through water year 1997 (October 1 to September 30) and for 191 low-flow partial-record stations with measurements into water year 1999. The characteristics presented for the long-term continuous-record stations are minimum daily streamflow; average daily streamflow; harmonic mean flow; 1-, 7-, 30-, and 90-day minimum average low flow with 2-, 5-, 10-, 20-, and 50-year recurrence intervals; and 98-, 95-, 90-, 85-, 80-, 75-, 70-, 60-, 50-, 40-, 30-, 20-, and 10-percent daily duration flows. The characteristics presented for the low-flow partial-record stations are minimum observed streamflow; estimated 1-, 7-, 30-, and 90-day minimum average low flow with 2-, 10-, and 20-year recurrence intervals; and estimated 98-, 95-, 90-, 85- and 80-percent daily duration flows. The low-flow frequency and duration analyses were done for three seasonal periods (warm weather, May 1 to November 30; winter, December 1 to February 28/29; and autumn, September 1 to November 30), plus the annual period based on the climatic year (April 1 to March 31).

Negotiation techniques to resolve western water disputes

USGS Publications Warehouse

Lamb, Berton L.; Taylor, Jonathan G.

1990-01-01

There is a growing literature on the resolution of natural resources conflicts. Much of it is practical, focusing on guidelines for hands-on negotiation. This literature can be a guide in water conflicts. This is especially true for negotiations over new environmental values such as instream flow. The concepts of competitive, cooperative, and integrative styles of conflict resolution are applied to three cases of water resource bargaining. Lessons for the effective use of these ideas include: break a large number of parties into small working groups, approach value differences in small steps, be cautious in the presence of an attentive public, keeps decisions at the local level, and understand the opponent's interests.

Modeling hydrology and in-stream transport on drained forested lands in coastal Carolinas, U.S.A.

Treesearch

Devendra Amatya

2005-01-01

This study summarizes the successional development and testing of forest hydrologic models based on DRAINMOD that predicts the hydrology of low-gradient poorly drained watersheds as affected by land management and climatic variation. The field scale (DRAINLOB) and watershed-scale in-stream routing (DRAINWAT) models were successfully tested with water table and outflow...

78 FR 20911 - Archon Energy 1, Inc.; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-08

... a short diversion method. The in-stream option would consist of the following: (1) A gated water intake canal; (2) a 70-foot by 55-foot by 35-foot turbine structure enclosing two in-stream VLH turbine... consist of the following: (1) a gated water intake canal; (2) a concrete trough diversion channel...

Estimated water use in Puerto Rico, 2010

USGS Publications Warehouse

Molina-Rivera, Wanda L.

2014-01-01

Water-use data were aggregated for the 78 municipios of the Commonwealth of Puerto Rico for 2010. Five major offstream categories were considered: public-supply water withdrawals and deliveries, domestic and industrial self-supplied water use, crop-irrigation water use, and thermoelectric-power freshwater use. One instream water-use category also was compiled: power-generation instream water use (thermoelectric saline withdrawals and hydroelectric power). Freshwater withdrawals for offstream use from surface-water [606 million gallons per day (Mgal/d)] and groundwater (118 Mgal/d) sources in Puerto Rico were estimated at 724 million gallons per day. The largest amount of freshwater withdrawn was by public-supply water facilities estimated at 677 Mgal/d. Public-supply domestic water use was estimated at 206 Mgal/d. Fresh groundwater withdrawals by domestic self-supplied users were estimated at 2.41 Mgal/d. Industrial self-supplied withdrawals were estimated at 4.30 Mgal/d. Withdrawals for crop irrigation purposes were estimated at 38.2 Mgal/d, or approximately 5 percent of all offstream freshwater withdrawals. Instream freshwater withdrawals by hydroelectric facilities were estimated at 556 Mgal/d and saline instream surface-water withdrawals for cooling purposes by thermoelectric-power facilities was estimated at 2,262 Mgal/d.

40 CFR Table 3 to Subpart Ec of... - Operating Parameters To Be Monitored and Minimum Measurement and Recording Frequencies

Code of Federal Regulations, 2011 CFR

2011-07-01

... scrubber followed by fabric filter Wet scrubber Dry scrubber followed by fabric filter and wet scrubber... flow rate Hourly 1×hour ✔ ✔ Minimum pressure drop across the wet scrubber or minimum horsepower or amperage to wet scrubber Continuous 1×minute ✔ ✔ Minimum scrubber liquor flow rate Continuous 1×minute...

14 CFR 23.1443 - Minimum mass flow of supplemental oxygen.

Code of Federal Regulations, 2010 CFR

2010-01-01

... discretion. (c) If first-aid oxygen equipment is installed, the minimum mass flow of oxygen to each user may... upon an average flow rate of 3 liters per minute per person for whom first-aid oxygen is required. (d...

Characterization of instream hydraulic and riparian habitat conditions and stream temperatures of the Upper White River Basin, Washington, using multispectral imaging systems

USGS Publications Warehouse

Black, Robert W.; Haggland, Alan; Crosby, Greg

2003-01-01

Instream hydraulic and riparian habitat conditions and stream temperatures were characterized for selected stream segments in the Upper White River Basin, Washington. An aerial multispectral imaging system used digital cameras to photograph the stream segments across multiple wavelengths to characterize fish habitat and temperature conditions. All imageries were georeferenced. Fish habitat features were photographed at a resolution of 0.5 meter and temperature imageries were photographed at a 1.0-meter resolution. The digital multispectral imageries were classified using commercially available software. Aerial photographs were taken on September 21, 1999. Field habitat data were collected from August 23 to October 12, 1999, to evaluate the measurement accuracy and effectiveness of the multispectral imaging in determining the extent of the instream habitat variables. Fish habitat types assessed by this method were the abundance of instream hydraulic features such as pool and riffle habitats, turbulent and non-turbulent habitats, riparian composition, the abundance of large woody debris in the stream and riparian zone, and stream temperatures. Factors such as the abundance of instream woody debris, the location and frequency of pools, and stream temperatures generally are known to have a significant impact on salmon. Instream woody debris creates the habitat complexity necessary to maintain a diverse and healthy salmon population. The abundance of pools is indicative of a stream's ability to support fish and other aquatic organisms. Changes in water temperature can affect aquatic organisms by altering metabolic rates and oxygen requirements, altering their sensitivity to toxic materials and affecting their ability to avoid predators. The specific objectives of this project were to evaluate the use of an aerial multispectral imaging system to accurately identify instream hydraulic features and surface-water temperatures in the Upper White River Basin, to use the multispectral system to help establish baseline instream/riparian habitat conditions in the study area, and to qualitatively assess the imaging system for possible use in other Puget Sound rivers. For the most part, all multispectral imagery-based estimates of total instream riffle and pool area were less than field measurements. The imagery-based estimates for riffle habitat area ranged from 35.5 to 83.3 percent less than field measurements. Pool habitat estimates ranged from 139.3 percent greater than field measurements to 94.0 percent less than field measurements. Multispectral imagery-based estimates of turbulent habitat conditions ranged from 9.3 percent greater than field measurements to 81.6 percent less than field measurements. Multispectral imagery-based estimates of non-turbulent habitat conditions ranged from 27.7 to 74.1 percent less than field measurements. The absolute average percentage of difference between field and imagery-based habitat type areas was less for the turbulent and non-turbulent habitat type categories than for pools and riffles. The estimate of woody debris by multispectral imaging was substantially different than field measurements; percentage of differences ranged from +373.1 to -100 percent. Although the total area of riffles, pools, and turbulent and non-turbulent habitat types measured in the field were all substantially higher than those estimated from the multispectral imagery, the percentage of composition of each habitat type was not substantially different between the imagery-based estimates and field measurements.

Projected increases in the annual flood pulse of the western Amazon

NASA Astrophysics Data System (ADS)

Zulkafli, Zed; Buytaert, Wouter; Manz, Bastian; Veliz Rosas, Claudia; Willems, Patrick; Lavado-Casimiro, Waldo; Guyot, Jean-Loup; Santini, William

2016-04-01

The impact of a changing climate on the Amazon basin is a subject of intensive research due to its rich biodiversity and the significant role of rain forest in carbon cycling. Climate change has also direct hydrological impact, and there have been increasing efforts to understand such dynamics at continental and subregional scales such as the scale of the western Amazon. New projections from the Coupled Model Inter- comparison Project Phase 5 (CMIP5) ensemble indicate consistent climatic warming and increasing seasonality of precipitation in the Peruvian Amazon basin. Here we use a distributed land surface model to quantify the potential impact of this change in the climate on the hydrological regime of the river. Using extremes value analysis, historical and future projections of the annual minimum, mean, and maximum river flows are produced for a range of return periods between 1 and 100 years. We show that the RCP 4.5 and 8.5 scenarios of climate change project an increased severity of the wet season flood pulse (7.5% and 12% increases respectively for the 100- year return floods). These findings are in agreement with previously projected increases in high extremes under the Special Report on Emissions Scenarios (SRES) climate projections, and are important to highlight due to the potential consequences on reproductive processes of in-stream species, swamp forest ecology, and socio-economy in the floodplain, amid a growing literature that more strongly emphasises future droughts and their impact on the viability of the rain forest system over the greater Amazonia.

Walla Walla River Fish Passage Operations Project : Annual Progress Report October 2007 - September 2008.

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

Bronson, James P.; Duke, Bill; Loffink, Ken

2008-12-30

In the late 1990s, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate fish migration conditions in the basin. Migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow requirements, and providing trap and haul efforts when needed. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survival ofmore » migrating adult and juvenile salmonids in the Walla Walla River basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage and trapping facility design, operation, and criteria. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. Beginning in March of 2007, two work elements from the Walla Walla Fish Passage Operations Project were transferred to other projects. The work element Enumeration of Adult Migration at Nursery Bridge Dam is now conducted under the Walla Walla Basin Natural Production Monitoring and Evaluation Project and the work element Provide Transportation Assistance is conducted under the Umatilla Satellite Facilities Operation and Maintenance Project. Details of these activities can be found in those project's respective annual reports.« less

Algal Biomass as an Indicator for Biochemical Oxygen Demand in the San Joaquin River, California.

NASA Astrophysics Data System (ADS)

Volkmar, E. C.; Dalhgren, R. A.

2005-12-01

Episodes of hypoxia (DO < 2 mg/L) occur in the lower San Joaquin River (SJR), California, and are typically most acute in the late summer and fall. The oxygen deficit can stress and kill aquatic organisms, and often inhibits the upstream migration of fall-run Chinook salmon. Hypoxia is most pronounced downstream from the Stockton Deep Water Ship Channel, which has been dredged from a depth of 2-3 m to about 11 m to allow ocean-going ships to reach the Port of Stockton. To protect aquatic organisms and facilitate the upstream migration of fall-run Chinook salmon, the minimum water quality standard for DO is 6 mg/L during September through November, and 5 mg/L for the remainder of the year. A five year study examined components contributing to biochemical oxygen demand (BOD): ammonia, algal biomass, non-algal particulate organic matter, and dissolved organic carbon. BOD shows a significant increase in loading rates as the SJR flows downstream, which parallels the load of algal biomass due to instream growth. BOD loading rates from tributaries accounts for 28% in a wet year and 39% in a dry year. Regression analysis revealed that chlorophyll-a + pheophyton-a was the only significant (p<0.05) predictor for BOD (r2 = 0.71). Less than 20% of the BOD was found in the dissolved fraction (<0.45 μm). The average BOD decomposition rate of the SJR and tributaries is 0.0841 d-1. We conclude that algal biomass is the primary contributor to BOD loads in the San Joaquin River.

Channel change and bed-material transport in the Umpqua River basin, Oregon

USGS Publications Warehouse

Wallick, J. Rose; O'Connor, Jim E.; Anderson, Scott; Keith, Mackenzie K.; Cannon, Charles; Risley, John C.

2011-01-01

The Umpqua River drains 12,103 square kilometers of western Oregon; with headwaters in the Cascade Range, the river flows through portions of the Klamath Mountains and Oregon Coast Range before entering the Pacific Ocean. Above the head of tide, the Umpqua River, along with its major tributaries, the North and South Umpqua Rivers, flows on a mixed bedrock and alluvium bed, alternating between bedrock rapids and intermittent, shallow gravel bars composed of gravel to cobble-sized clasts. These bars have been a source of commercial aggregate since the mid-twentieth century. Below the head of tide, the Umpqua River contains large bars composed of mud and sand. Motivated by ongoing permitting and aquatic habitat concerns related to in-stream gravel mining on the fluvial reaches, this study evaluated spatial and temporal trends in channel change and bed-material transport for 350 kilometers of river channel along the Umpqua, North Umpqua, and South Umpqua Rivers. The assessment produced (1) detailed mapping of the active channel, using aerial photographs and repeat surveys, and (2) a quantitative estimation of bed-material flux that drew upon detailed measurements of particle size and lithology, equations of transport capacity, and a sediment yield analysis. Bed-material transport capacity estimates at 45 sites throughout the South Umpqua and main stem Umpqua Rivers for the period 1951-2008 result in wide-ranging transport capacity estimates, reflecting the difficulty of applying equations of bed-material transport to a supply-limited river. Median transport capacity values calculated from surface-based equations of bedload transport for each of the study reaches provide indications of maximum possible transport rates and range from 8,000 to 27,000 metric tons per year (tons/yr) for the South Umpqua River and 20,000 to 82,000 metric tons/yr for the main stem Umpqua River upstream of the head of tide; the North Umpqua River probably contributes little bed material. A plausible range of average annual transport rates for the South and main stem Umpqua Rivers, based on bedload transport capacity estimates for bars with reasonable values for reference shear stress, is between 500 and 20,000 metric tons/yr. An empirical bed-material yield analysis predicts 20,000-50,000 metric tons/yr on the South Umpqua River and main stem Umpqua River through the Oregon Coast Range, decreasing to approximately 30,000 metric tons/yr at the head of tide. Surveys of individual mining sites in the South Umpqua River indicate minimum local bed-material flux rates that are typically less than 10,000 metric tons/yr but range up to 30,600 metric tons/yr in high-flow years. On the basis of all of these analyses, actual bedload flux in most years is probably less than 25,000 metric tons/yr in the South Umpqua and main stem Umpqua Rivers, with the North Umpqua River probably contributing negligible amounts. For comparison, the estimated annual volume of commercial gravel extraction from the South Umpqua River between 2001 and 2004 ranged from 610 to 36,570 metric tons, indicating that historical in-stream gravel extraction may have been a substantial fraction of the overall bedload flux.

Hydro-economic optimization model for selecting least cost programs of measures at the river basin scale. Application to the implementation of the EU Water Framework Directive on the Orb river basin (France).

NASA Astrophysics Data System (ADS)

Girard, C.; Rinaudo, J. D.; Caballero, Y.; Pulido-Velazquez, M.

2012-04-01

This article presents a case study which illustrates how an integrated hydro-economic model can be applied to optimize a program of measures (PoM) at the river basin level. By allowing the integration of hydrological, environmental and economic aspects at a local scale, this model is indeed useful to assist water policy decision making processes. The model identifies the least cost PoM to satisfy the predicted 2030 urban and agricultural water demands while meeting the in-stream flow constraints. The PoM mainly consists of water saving and conservation measures at the different demands. It includes as well some measures mobilizing additional water resources coming from groundwater, inter-basin transfers and improvement in reservoir operating rules. The flow constraints are defined to ensure a good status of the surface water bodies, as defined by the EU Water Framework Directive (WFD). The case study is conducted in the Orb river basin, a coastal basin in Southern France. It faces a significant population growth, changes in agricultural patterns and limited water resources. It is classified at risk of not meeting the good status by 2015. Urban demand is calculated by type of water users at municipality level in 2006 and projected to 2030 with user specific scenarios. Agricultural water demand is estimated at irrigation district (canton) level in 2000 and projected to 2030 under three agricultural development scenarios. The total annual cost of each measure has been calculated taken into account operation and maintenance costs as well as investment cost. A first optimization model was developed using GAMS, General Algebraic Modeling System, applying Mixed Integer Linear Programming. The optimization is run to select the set of measures that minimizes the objective function, defined as the total cost of the applied measures, while meeting the demands and environmental constraints (minimum in-stream flows) for the 2030 time horizon. The first result is an optimized PoM on a drought year with a return period of five years, taken as a baseline scenario. A second step takes into account the impact of climate change on water demands and available resources. This allows decision makers to assess how the cost of the PoM evolves when the level of environmental constraints is increased or loosed, and so provides them a valuable input to understand the opportunity costs and trade-offs when defining environmental objectives for the long term, including also climate as a major factor of change. Finally, the model will be used on an extended hydrological time series to study costs and impacts of the PoM on the allocation of water resources. This will also allow the investigation of the uncertainties and the effect of risk aversion of decision makers and users on the system management, as well as the influence of the perfect foresight of deterministic optimization. ACKNOWLEDGEMENTS The study has been partially supported by the BRGM project Ouest-Hérault, the European Community 7th Framework Project GENESIS (n. 226536) on groundwater systems, and the Plan Nacional I+D+I 2008-2011 of the Spanish Ministry of Science and Innovation (sub-projects CGL2009-13238-C02-01 and CGL2009-13238-C02-02).

Multicriteria decision analysis applied to Glen Canyon Dam

USGS Publications Warehouse

Flug, M.; Seitz, H.L.H.; Scott, J.F.

2000-01-01

Conflicts in water resources exist because river-reservoir systems are managed to optimize traditional benefits (e.g., hydropower and flood control), which are historically quantified in economic terms, whereas natural and environmental resources, including in-stream and riparian resources, are more difficult or impossible to quantify in economic terms. Multicriteria decision analysis provides a quantitative approach to evaluate resources subject to river basin management alternatives. This objective quantification method includes inputs from special interest groups, the general public, and concerned individuals, as well as professionals for each resource considered in a trade-off analysis. Multicriteria decision analysis is applied to resources and flow alternatives presented in the environmental impact statement for Glen Canyon Dam on the Colorado River. A numeric rating and priority-weighting scheme is used to evaluate 29 specific natural resource attributes, grouped into seven main resource objectives, for nine flow alternatives enumerated in the environmental impact statement.

Elkhorn ruling boosts state authority

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

Beecher, H.A.

1995-03-01

On 31 May 1994, a landmark U.S. Supreme Court decision expanded state authority to establish conditions to protect water quality and included stream flows, aesthetics, and, potentially, other elements in a broad definition of water quality. Called the {open_quotes}Elkhorn case{close_quotes} the Supreme Court ruled that the state of Washington Department of Ecology has authority to set instream flows for fish (primarily steelhead, chinook, and coho salmon) as a condition of a Water Quality Certification (WQC) issued by the state under Section 401 of the federal Clean Water Act (CWA). The case surrounded the petitioners (applicants) proposed building of the Elkhornmore » Hydroelectric Project on the Dosewallips River, Washington. The project would have consisted of a dam near the boundary of Olympic National Park and a pipeline to carry diverted water around a 1.2-mile bypass reach to a powerhouse at Olympic National Forest`s Elkhorn Campground.« less

Distribution of subtidal sedimentary bedforms in a macrotidal setting: The Bay of Fundy, Atlantic Canada

NASA Astrophysics Data System (ADS)

Todd, Brian J.; Shaw, John; Li, Michael Z.; Kostylev, Vladimir E.; Wu, Yongsheng

2014-07-01

The Bay of Fundy, Canada, a large macrotidal embayment with the World's highest recorded tides, was mapped using multibeam sonar systems. High-resolution imagery of seafloor terrain and backscatter strength, combined with geophysical and sampling data, reveal for the first time the morphology, architecture, and spatial relationships of a spectrum of bedforms: (1) flow-transverse bedforms occur as both discrete large two-dimensional dunes and as three-dimensional dunes in sand sheets; (2) flow-parallel bedforms are numerous straight ridges described by others as horse mussel bioherms; (3) sets of banner banks that flank prominent headlands and major shoals. The suite of bedforms developed during the Holocene, as tidal energy increased due to the bay approaching resonance. We consider the evolution of these bedforms, their migration potential and how they may place limitations on future in-stream tidal power development in the Bay of Fundy.

American Recovery and Reinvestment Act: North Fork Skokomish Powerhouse at Cushman No. 2 Dam

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

Fischer, Steve; McCarty, Patrick

2013-09-30

The objective of this project was to add generating capacity on an in-stream flow release at Tacoma Power's Cushman hydroelectric project, Cushman No. 2 Dam, FERC Project P-460. The flow that is being used to generate additional electricity was being discharged from a valve at the base of the dam without recovery of the energy. A second objective to the project was to incorporate upstream fish passage by use of a fish collection structure attached to the draft tubes of the hydroelectric units. This will enable reintroduction of native anadromous fish above the dams which have blocked fish passage sincemore » the late 1920's. The project was funded in part by the American Recovery and Reinvestment Act through the Department of Energy, Office of Energy, Efficiency and Renewable Energy, Wind and Water Power Program.« less

Framework for developing hybrid process-driven, artificial neural network and regression models for salinity prediction in river systems

NASA Astrophysics Data System (ADS)

Hunter, Jason M.; Maier, Holger R.; Gibbs, Matthew S.; Foale, Eloise R.; Grosvenor, Naomi A.; Harders, Nathan P.; Kikuchi-Miller, Tahali C.

2018-05-01

Salinity modelling in river systems is complicated by a number of processes, including in-stream salt transport and various mechanisms of saline accession that vary dynamically as a function of water level and flow, often at different temporal scales. Traditionally, salinity models in rivers have either been process- or data-driven. The primary problem with process-based models is that in many instances, not all of the underlying processes are fully understood or able to be represented mathematically. There are also often insufficient historical data to support model development. The major limitation of data-driven models, such as artificial neural networks (ANNs) in comparison, is that they provide limited system understanding and are generally not able to be used to inform management decisions targeting specific processes, as different processes are generally modelled implicitly. In order to overcome these limitations, a generic framework for developing hybrid process and data-driven models of salinity in river systems is introduced and applied in this paper. As part of the approach, the most suitable sub-models are developed for each sub-process affecting salinity at the location of interest based on consideration of model purpose, the degree of process understanding and data availability, which are then combined to form the hybrid model. The approach is applied to a 46 km reach of the Murray River in South Australia, which is affected by high levels of salinity. In this reach, the major processes affecting salinity include in-stream salt transport, accession of saline groundwater along the length of the reach and the flushing of three waterbodies in the floodplain during overbank flows of various magnitudes. Based on trade-offs between the degree of process understanding and data availability, a process-driven model is developed for in-stream salt transport, an ANN model is used to model saline groundwater accession and three linear regression models are used to account for the flushing of the different floodplain storages. The resulting hybrid model performs very well on approximately 3 years of daily validation data, with a Nash-Sutcliffe efficiency (NSE) of 0.89 and a root mean squared error (RMSE) of 12.62 mg L-1 (over a range from approximately 50 to 250 mg L-1). Each component of the hybrid model results in noticeable improvements in model performance corresponding to the range of flows for which they are developed. The predictive performance of the hybrid model is significantly better than that of a benchmark process-driven model (NSE = -0.14, RMSE = 41.10 mg L-1, Gbench index = 0.90) and slightly better than that of a benchmark data-driven (ANN) model (NSE = 0.83, RMSE = 15.93 mg L-1, Gbench index = 0.36). Apart from improved predictive performance, the hybrid model also has advantages over the ANN benchmark model in terms of increased capacity for improving system understanding and greater ability to support management decisions.

Effects of watershed and in-stream liming on macroinvertebrate communities in acidified tributaries to an Adirondack lake

USGS Publications Warehouse

George, Scott D.; Baldigo, Barry P.; Lawrence, Gregory B.; Fuller, Randall L.

2018-01-01

Liming techniques are being explored as a means to accelerate the recovery of aquatic biota from decades of acid deposition in many regions. The preservation or restoration of native sportfish populations has typically been the impetus for liming programs, and as such, less attention has been given to its effects on other biological assemblages such as macroinvertebrates. Furthermore, the differing effects of various lime application strategies such as in-stream and watershed applications are not well understood. In 2012, a program was initiated using in-stream and aerial (whole-watershed) liming to improve water quality and Brook Trout (Salvelinus fontinalis) recruitment in three acidified tributaries of a high-elevation Adirondack lake in New York State. Concurrently, macroinvertebrates were sampled annually between 2013 and 2016 at 3 treated sites and 3 untreated reference sites to assess the effects of each liming technique on this community. Despite improvements in water chemistry in all three limed streams, our results generally suggest that neither liming technique succeeded in improving the condition of macroinvertebrate communities. The watershed application caused an immediate and unsustained decrease in the density of macroinvertebrates and increase in the proportion of sensitive taxa. These changes were driven primarily by a one-year 71 percent reduction of the acid-tolerant Leuctra stoneflies and likely represent an initial chemistry shock from the lime application rather than a recovery response. The in-stream applications appeared to reduce the density of macroinvertebrates, particularly in one stream where undissolved lime covered the natural substrate. The close proximity of our study sites to the in-stream application points (50 and 1230 m) may partly explain these negative effects. Our results are consistent with prior studies of in-stream liming which indicate that this technique often fails to restore macroinvertebrate communities to a pre-acidification condition, especially at distances <1.5 km downstream of the lime application point. The inability of either liming technique to improve the condition of macroinvertebrate communities may be partly explained by the persistence of acidic episodes in all three streams. This suggests that in order to be effective, liming programs should attempt to eliminate even temporary episodes of unsuitable water chemistry rather than just meeting minimal criteria the majority of the time. Because watershed liming produced a more stable water chemistry regime than in-stream liming, this technique may have greater future potential to eliminate toxic episodes and accelerate the recovery of acid-impacted macroinvertebrate communities.

Low-flow analysis and selected flow statistics representative of 1930-2002 for streamflow-gaging stations in or near West Virginia

USGS Publications Warehouse

Wiley, Jeffrey B.

2006-01-01

Five time periods between 1930 and 2002 are identified as having distinct patterns of annual minimum daily mean flows (minimum flows). Average minimum flows increased around 1970 at many streamflow-gaging stations in West Virginia. Before 1930, however, there might have been a period of minimum flows greater than any period identified between 1930 and 2002. The effects of climate variability are probably the principal causes of the differences among the five time periods. Comparisons of selected streamflow statistics are made between values computed for the five identified time periods and values computed for the 1930-2002 interval for 15 streamflow-gaging stations. The average difference between statistics computed for the five time periods and the 1930-2002 interval decreases with increasing magnitude of the low-flow statistic. The greatest individual-station absolute difference was 582.5 percent greater for the 7-day 10-year low flow computed for 1970-1979 compared to the value computed for 1930-2002. The hydrologically based low flows indicate approximately equal or smaller absolute differences than biologically based low flows. The average 1-day 3-year biologically based low flow (1B3) and 4-day 3-year biologically based low flow (4B3) are less than the average 1-day 10-year hydrologically based low flow (1Q10) and 7-day 10-year hydrologic-based low flow (7Q10) respectively, and range between 28.5 percent less and 13.6 percent greater. Seasonally, the average difference between low-flow statistics computed for the five time periods and 1930-2002 is not consistent between magnitudes of low-flow statistics, and the greatest difference is for the summer (July 1-September 30) and fall (October 1-December 31) for the same time period as the greatest difference determined in the annual analysis. The greatest average difference between 1B3 and 4B3 compared to 1Q10 and 7Q10, respectively, is in the spring (April 1-June 30), ranging between 11.6 and 102.3 percent greater. Statistics computed for the individual station's record period may not represent the statistics computed for the period 1930 to 2002 because (1) station records are available predominantly after about 1970 when minimum flows were greater than the average between 1930 and 2002 and (2) some short-term station records are mostly during dry periods, whereas others are mostly during wet periods. A criterion-based sampling of the individual station's record periods at stations was taken to reduce the effects of statistics computed for the entire record periods not representing the statistics computed for 1930-2002. The criterion used to sample the entire record periods is based on a comparison between the regional minimum flows and the minimum flows at the stations. Criterion-based sampling of the available record periods was superior to record-extension techniques for this study because more stations were selected and areal distribution of stations was more widespread. Principal component and correlation analyses of the minimum flows at 20 stations in or near West Virginia identify three regions of the State encompassing stations with similar patterns of minimum flows: the Lower Appalachian Plateaus, the Upper Appalachian Plateaus, and the Eastern Panhandle. All record periods of 10 years or greater between 1930 and 2002 where the average of the regional minimum flows are nearly equal to the average for 1930-2002 are determined as representative of 1930-2002. Selected statistics are presented for the longest representative record period that matches the record period for 77 stations in West Virginia and 40 stations near West Virginia. These statistics can be used to develop equations for estimating flow in ungaged stream locations.

Riparian forest and instream large wood characteristics, West Branch Sheepscot River, Maine, USA

Treesearch

Melissa Laser; James Jordan; Keith Nislow

2009-01-01

This study examined riparian forest and instream large wood characteristics in a 2.7 km reach of the West Branch of the Sheepscot River in Maine in order to increase our basic knowledge of these components in a system that is known to have undergone multiple land conversion. The West Branch is approximately 40 km long, drains a 132 km2...

Effects of Land Use and Land Cover, Stream Discharge, and Interannual Climate on the Magnitude and Timing of Nitrogen, Phosphorus, and Organic Carbon Concentrations in Three Coastal Plain Watersheds

EPA Science Inventory

In-stream nitrogen, phosphorus, organic carbon, and suspended sediment concentrations were measured in 18 sub-basins over two annual cycles to assess how land-use/land-cover (LULC) and stream discharge regulate water quality variables. LULC was a primary driver of in-stream const...

A two end-member model of wood dynamics in headwater neotropical rivers

Treesearch

Ellen Wohl; Susan Bolton; Daniel Cadol; Francesco Comiti; Jaime R. Goode; Luca Mao

2012-01-01

Geomorphic and ecological effects of instream wood have been documented primarily along rivers in the temperate zones. Instream wood loads in tropical rivers might be expected to differ from those in analogous temperate rivers because of the higher transport capacity and higher rates of wood decay in the tropics. We use data from four field sites in Costa Rica and...

Guidelines and Procedures for Computing Time-Series Suspended-Sediment Concentrations and Loads from In-Stream Turbidity-Sensor and Streamflow Data

USGS Publications Warehouse

Rasmussen, Patrick P.; Gray, John R.; Glysson, G. Douglas; Ziegler, Andrew C.

2009-01-01

In-stream continuous turbidity and streamflow data, calibrated with measured suspended-sediment concentration data, can be used to compute a time series of suspended-sediment concentration and load at a stream site. Development of a simple linear (ordinary least squares) regression model for computing suspended-sediment concentrations from instantaneous turbidity data is the first step in the computation process. If the model standard percentage error (MSPE) of the simple linear regression model meets a minimum criterion, this model should be used to compute a time series of suspended-sediment concentrations. Otherwise, a multiple linear regression model using paired instantaneous turbidity and streamflow data is developed and compared to the simple regression model. If the inclusion of the streamflow variable proves to be statistically significant and the uncertainty associated with the multiple regression model results in an improvement over that for the simple linear model, the turbidity-streamflow multiple linear regression model should be used to compute a suspended-sediment concentration time series. The computed concentration time series is subsequently used with its paired streamflow time series to compute suspended-sediment loads by standard U.S. Geological Survey techniques. Once an acceptable regression model is developed, it can be used to compute suspended-sediment concentration beyond the period of record used in model development with proper ongoing collection and analysis of calibration samples. Regression models to compute suspended-sediment concentrations are generally site specific and should never be considered static, but they represent a set period in a continually dynamic system in which additional data will help verify any change in sediment load, type, and source.

Mature and old-growth riparian forests: structure, dynamics, and effects on Adirondack stream habitats.

PubMed

Keeton, William S; Kraft, Clifford E; Warren, Dana R

2007-04-01

Riparian forests regulate linkages between terrestrial and aquatic ecosystems, yet relationships among riparian forest development, stand structure, and stream habitats are poorly understood in many temperate deciduous forest systems. Our research has (1) described structural attributes associated with old-growth riparian forests and (2) assessed linkages between these characteristics and in-stream habitat structure. The 19 study sites were located along predominantly first- and second-order streams in northern hardwood-conifer forests in the Adirondack Mountains of New York (U.S.A.). Sites were classified as mature forest (6 sites), mature with remnant old-growth trees (3 sites), and old-growth (10 sites). Forest-structure attributes were measured over stream channels and at varying distances from each bank. In-stream habitat features such as large woody debris (LWD), pools, and boulders were measured in each stream reach. Forest structure was examined in relation to stand age using multivariate techniques, ANOVA, and linear regression. We investigated linkages between forest structure and stream characteristics using similar methods, preceded by information-theoretic modeling (AIC). Old-growth riparian forest structure is more complex than that found in mature forests and exhibits significantly greater accumulations of aboveground tree biomass, both living and dead. In-stream LWD volumes were significantly (alpha = 0.05) greater at old-growth sites (200 m3/ha) compared to mature sites (34 m3/ha) and were strongly related to the basal area of adjacent forests. In-stream large-log densities correlated strongly with debris-dam densities. AIC models that included large-log density, debris-dam density, boulder density, and bankfull width had the most support for predicting pool density. There were higher proportions of LWD-formed pools relative to boulder-formed pools at old-growth sites as compared to mature sites. Old-growth riparian forests provide in-stream habitat features that have not been widely recognized in eastern North America, representing a potential benefit from late-successional riparian forest management and conservation. Riparian management practices (including buffer delineation and restorative silvicultural approaches) that emphasize development and maintenance of late-successional characteristics are recommended where the associated in-stream effects are desired.

The impact of run-off change on physical instream habitats and its response to river morphology

NASA Astrophysics Data System (ADS)

Hauer, Christoph; Habersack, Helmut

2010-05-01

Rivers have already been substantially altered by human activity. Channelization, flow regulation, or changes in land use, especially urbanization, significantly alter the water discharge, sediment transport, and morphology of rivers. The impacts of these anthropogenic measures (disturbances) on river morphology and instream habitats were frequently investigated by the scientific community over the last decades. However, there are forms of disturbances (often induced by climate change) which cause at the beginning only a slight but (over the years) a continuous degradation of aquatic habitats (and river morphology). In the presented study the impact of such disturbances caused by climate change on summer run-off was investigated within the Gr. Mühl River catchment, Austria. So far, various studies have documented the impact of run-off change on river morphology and/or sediment load. Further the impact of run-off change on aquatic ecology (target fish species) have been documented throughout various scientific papers. However, there is a lack of knowledge how (climate induced) run-off changes affect instream aquatic habitats concerning various morphological patterns (e.g. riffle-pool morphology vs. plane bed river). Thus, the aim of the presented study was to link the impacts of climate change (e.g. reduced summer run-off) to various morphological types (riffle-pool, plane bed) using habitat modelling (2-dimensional) as integrative evaluation method. As target fish species sub-adult/adult grayling was selected due to the fact, that Thymallus thymallus features especially high sensitivity in water depth (microhabitat use). Further grayling was one the historically dominant fish species for the hyporhithral catchment of the Gr. Mühl River. Within the catchment 80% of the total river length are determined as plane bed river and 20 % as riffle-pool reaches (situated in former fine material deposits). Six reaches (3 plane-bed, 3 riffle-pool) were selected and surveyed by total station (Leica805) to derive high quality DTM-models for modelling. Monitoring data of temperature (period: 1948 - 2006) and gauging data of three stations (Vorderanger, period: 1966 - 2008; Furthmühle, period: 1951 - 2008; Teufelmühle, period: 1951 - 2008) along the investigated reach were additionally provided by the local government agencies. The results of the statistical testing (for significant breakpoints in temperature trends) exhibited significant changes (p>95%) for the seasons spring (year 1989) and summer (year 1990) (increase in regional temperature). Simultaneously, the periods of run-off below statistically determined low-flow thresholds increased significantly especially for summer periods (e.g. gauging station Furthmühle: period 1951 - 1990: n = 684 days / 1990 - 2008: n = 760 days). The impact of those intensified low flow conditions on subadult / adult grayling were (and are) limiting available physical habitats especially within the plane-bed sections (n=3). Only riffle-pool reaches exhibited suitable habitats (evaluated by habitatmodelling) for these dry-periods. However, those riffle-pool reaches are rare and randomly distributed over the 45 km river length (investigated reach). In the presented study it could be figured out, that climate change affects instream fish habitats not only by an increase in water temperatures, but also by limiting physical habitats (in relation to various morphological types). Thus, the response of fish (e.g. grayling) could be on the one hand an upstream migration due to the warmer water temperatures (frequently documented) but on the other hand a downstream migration caused by unsuitable habitats. This second finding should be seen as one crucial point especially for the restoration of regulated rivers with respect to climate change and to fulfil the aims of the European Water Framework Directive.

Determination of hyporheic travel time distributions and other parameters from concurrent conservative and reactive tracer tests by local-in-global optimization

NASA Astrophysics Data System (ADS)

Knapp, Julia L. A.; Cirpka, Olaf A.

2017-06-01

The complexity of hyporheic flow paths requires reach-scale models of solute transport in streams that are flexible in their representation of the hyporheic passage. We use a model that couples advective-dispersive in-stream transport to hyporheic exchange with a shape-free distribution of hyporheic travel times. The model also accounts for two-site sorption and transformation of reactive solutes. The coefficients of the model are determined by fitting concurrent stream-tracer tests of conservative (fluorescein) and reactive (resazurin/resorufin) compounds. The flexibility of the shape-free models give rise to multiple local minima of the objective function in parameter estimation, thus requiring global-search algorithms, which is hindered by the large number of parameter values to be estimated. We present a local-in-global optimization approach, in which we use a Markov-Chain Monte Carlo method as global-search method to estimate a set of in-stream and hyporheic parameters. Nested therein, we infer the shape-free distribution of hyporheic travel times by a local Gauss-Newton method. The overall approach is independent of the initial guess and provides the joint posterior distribution of all parameters. We apply the described local-in-global optimization method to recorded tracer breakthrough curves of three consecutive stream sections, and infer section-wise hydraulic parameter distributions to analyze how hyporheic exchange processes differ between the stream sections.

Rehabilitating agricultural streams in Australia with wood: a review.

PubMed

Lester, Rebecca E; Boulton, Andrew J

2008-08-01

Worldwide, the ecological condition of streams and rivers has been impaired by agricultural practices such as broadscale modification of catchments, high nutrient and sediment inputs, loss of riparian vegetation, and altered hydrology. Typical responses include channel incision, excessive sedimentation, declining water quality, and loss of in-stream habitat complexity and biodiversity. We review these impacts, focusing on the potential benefits and limitations of wood reintroduction as a transitional rehabilitation technique in these agricultural landscapes using Australian examples. In streams, wood plays key roles in shaping velocity and sedimentation profiles, forming pools, and strengthening banks. In the simplified channels typical of many agricultural streams, wood provides habitat for fauna, substrate for biofilms, and refuge from predators and flow extremes, and enhances in-stream diversity of fish and macroinvertebrates.Most previous restoration studies involving wood reintroduction have been in forested landscapes, but some results might be extrapolated to agricultural streams. In these studies, wood enhanced diversity of fish and macroinvertebrates, increased storage of organic material and sediment, and improved bed and bank stability. Failure to meet restoration objectives appeared most likely where channel incision was severe and in highly degraded environments. Methods for wood reintroduction have logistical advantages over many other restoration techniques, being relatively low cost and low maintenance. Wood reintroduction is a viable transitional restoration technique for agricultural landscapes likely to rapidly improve stream condition if sources of colonists are viable and water quality is suitable.

A gas-tracer injection for evaluating the fate of methane in a coastal plain stream: Degassing versus in-stream oxidation

USGS Publications Warehouse

Heilweil, Victor M.; Solomon, D. Kip; Darrah, Thomas H.; Gilmore, Troy E.; Genereux, David P.

2016-01-01

Methane emissions from streams and rivers have recently been recognized as an important component of global greenhouse budgets. Stream methane is lost as evasion to the atmosphere or in-stream methane oxidation. Previous studies have quantified evasion and oxidation with point-scale measurements. In this study, dissolved gases (methane, krypton) were injected into a coastal plain stream in North Carolina to quantify stream CH4 losses at the watershed scale. Stream-reach modeling yielded gas transfer and oxidation rate constants of 3.2 ± 0.5 and 0.5 ± 1.5 d–1, respectively, indicating a ratio of about 6:1. The resulting evasion and oxidation rates of 2.9 mmol m–2 d–1 and 1,140 nmol L–1 d–1, respectively, lie within ranges of published values. Similarly, the gas transfer velocity (K600) of 2.1 m d–1 is consistent with other gas tracer studies. This study illustrates the utility of dissolved-gas tracers for evaluating stream methane fluxes. In contrast to point measurements, this approach provides a larger watershed-scale perspective. Further work is needed to quantify the magnitude of these fluxes under varying conditions (e.g., stream temperature, nutrient load, gradient, flow rate) at regional and global scales before reliable bottom-up estimates of methane evasion can be determined at global scales.

Water quality, physical habitat, and fish community composition in streams in the Twin Cities metropolitan area, Minnesota, 1997-98

USGS Publications Warehouse

Talmage, Philip J.; Lee, Kathy E.; Goldstein, Robert M.; Anderson, Jesse P.; Fallon, James D.

1999-01-01

Water quality, physical habitat, and fish-community composition were characterized at 13 Twin Cities metropolitan area streams during low-flow conditions, September 1997. Fish communities were resampled during September 1998. Sites were selected based on a range of human population density. Nutrient concentrations were generally low, rarely exceeding concentrations found in agricultural streams or water-quality criteria. Seventeen pesticides and five pesticide metabolites were detected, with atrazine being the only pesticide detected at all 13 streams. Colony counts of fecal coliform bacteria ranged from 54 to greater than 11,000 colonies per 100 mL. Instream fish habitat was sparse with little woody debris and few boulders, cobble, or other suitable fish habitat. Thirty-eight species and one hybrid from 10 families were collected. Fish communities were characterized by high percentages of omnivores and tolerant species with few intolerant species. Index of Biotic Integrity scores were low, with most streams rating fair to very poor. Percent impervious surface was positively correlated with sodium and chloride concentrations and human population density, but was negatively correlated with fish species richness and diversity. Urban land use and human population density influence fish communities and water quality in Twin Cities metropolitan area streams. Other factors that may influence fish community composition include percent impervious cover, water chemistry, water temperature, geomorphology, substrate, instream habitat, and migration barriers.

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.

Historic evidence for a link between riparian vegetation and bank erosion in the context of instream habitat restoration

NASA Astrophysics Data System (ADS)

Salant, N.; Baillie, M. B.; Schmidt, J. C.; Intermountain CenterRiver Rehabilitation; Restoration

2010-12-01

An analysis of historic aerial photographs of the upper Strawberry River, Utah, demonstrates that rates of lateral bank erosion peaked with the loss of riparian cover during periods of willow removal for livestock grazing. Erosion rates have declined over the past two decades, concurrent with the removal of livestock grazing, modest increases in riparian cover, and the return of natural flows. Contrary to perception, present-day erosion rates are actually lower than pre-disturbance rates. Recent restoration activities to stabilize stream banks were based on the assumption that high erosion rates were contributing excess sediment to the streambed and degrading spawning gravels. However, our results show that while the historic loss of riparian vegetation contributed to an increase in bank erosion rates, bank erosion rates were not high prior to restoration. Furthermore, streambed samples show that the percentage of fine sediment in the substrate is insufficient to have a significant biological impact, supporting the finding that present-day bank erosion rates are not excessive relative to pre-disturbance rates. Current bank stabilization efforts were therefore motivated by a limited understanding of system conditions and history, suggesting that these restoration activities are unnecessary and misconceived. Our results demonstrate the large influence of riparian vegetation on bank erosion and instream habitat, as well as the importance of incorporating system history into restoration design.

Application of SELECT and SWAT models to simulate source load, fate, and transport of fecal bacteria in watersheds.

NASA Astrophysics Data System (ADS)

Ranatunga, T.

2017-12-01

Modeling of fate and transport of fecal bacteria in a watershed is a processed based approach that considers releases from manure, point sources, and septic systems. Overland transport with water and sediments, infiltration into soils, transport in the vadose zone and groundwater, die-off and growth processes, and in-stream transport are considered as the other major processes in bacteria simulation. This presentation will discuss a simulation of fecal indicator bacteria source loading and in-stream conditions of a non-tidal watershed (Cedar Bayou Watershed) in South Central Texas using two models; Spatially Explicit Load Enrichment Calculation Tool (SELECT) and Soil and Water Assessment Tool (SWAT). Furthermore, it will discuss a probable approach of bacteria source load reduction in order to meet the water quality standards in the streams. The selected watershed is listed as having levels of fecal indicator bacteria that posed a risk for contact recreation and wading by the Texas Commission of Environmental Quality (TCEQ). The SELECT modeling approach was used in estimating the bacteria source loading from land categories. Major bacteria sources considered were, failing septic systems, discharges from wastewater treatment facilities, excreta from livestock (Cattle, Horses, Sheep and Goat), excreta from Wildlife (Feral Hogs, and Deer), Pet waste (mainly from Dogs), and runoff from urban surfaces. The estimated source loads from SELECT model were input to the SWAT model, and simulate the bacteria transport through the land and in-stream. The calibrated SWAT model was then used to estimate the indicator bacteria in-stream concentrations for future years based on regional land use, population and household forecast (up to 2040). Based on the reductions required to meet the water quality standards in-stream, the corresponding required source load reductions were estimated.

Forecast Informed Reservoir Operations - An Opportunity to Improve Water Supply Reliability Lake Mendocino Demonstration Project

NASA Astrophysics Data System (ADS)

Jasperse, J.; Ralph, F. M.

2016-12-01

Forecast Informed Reservoir Operations (FIRO) is a management strategy that is gaining interest in the western United States as a means to improve the performance of reservoirs to provide more reliable water supply for municipal, agricultural, and environmental water needs as well as enhancing the flood protection capacity of reservoirs. Many surface water reservoirs were built decades ago and are operated in accordance with rules that were developed based on the best information at the time of construction. Over time there have been increasing stressors that impact effective reservoir operations including: increasing water demand; providing in-stream flows for habitat of aquatic species; and climate change. Few new reservoirs are being constructed, therefore there is motivation by water managers to more effectively operate existing reservoirs by optimizing operational rules under a decision framework that considers forecasting. The viability of FIRO is being investigated at Lake Mendocino in northern California. This facility is managed for flood protection by the U.S. Army Corps of Engineers (USACE) while the Sonoma County Water Agency (SCWA) is responsible for the management of the water supply pool. Reductions of reservoir inflow due to recent operational license conditions of an upstream hydroelectric facility coupled with highly variable precipitation (due to the significance of atmospheric rivers in the region) has led to difficulties in maintaining reservoir storage to meet stream flows for agricultural and municipal water users and to meet in-stream flow requirements for three salmonid species listed under the Endangered Species Act. The reduced water supply reliability of the reservoir has motivated water managers and scientists from local, state, and federal agencies to investigate whether FIRO could help address this challenge. This effort is led by a Steering Committee comprised of members from SCWA, Scripps-UC San Diego, USACE, NOAA, California Department of Water Resources, USGS, and Bureau of Reclamation. The partnership is involved with: conducting a preliminary viability assessment; evaluating operational strategies and decision support tools should FIRO be found to be viable; and coordinating research to support advances in new technology and improved forecasting skill.

Water Quality and Streamflow of the Indian River, Sitka, Alaska, 2001-02

USGS Publications Warehouse

Neal, Edward J.; Brabets, Timothy P.; Frenzel, Steven A.

2004-01-01

The Indian River Basin, located near Sitka Alaska, drains an area of 12.3 square miles. This watershed is an important natural resource of Sitka National Historic Park. At the present time, the watershed faces possible development on large tracts of private land upstream of the park that could affect the water quality of Indian River. Due to this concern, a study was conducted cooperatively with the National Park Service. The approach was to examine the water quality of the Indian River in the upper part of the watershed where no development has occurred and in the lower part of the basin where development has taken place. Measurements of pH, water temperature, and dissolved oxygen concentrations of the Indian River were within acceptable ranges for fish survival. The Indian River is calcium bicarbonate type water with a low buffering capacity. Concentrations of dissolved ions and nutrients generally were low and exhibited little variation between the two study sites. Analysis of bed sediment trace element concentrations at both sampling sites indicates the threshold effect concentration was exceeded for arsenic, chromium, copper, nickel, and zinc; while the probable effect concentration was exceeded by arsenic, chromium and nickel. However, due to relatively large amounts of organic carbon present in the bed sediments, the potential toxicity from trace elements is low. Discharge in the Indian River is typical of coastal southeast Alaska streams where low flows generally are in late winter and early spring and greater flows are during the wetter fall months. Alaska Department of Fish and Game has established instream flow reservations on the lower 2.5 miles of the Indian River. Discharge data indicate minimum flow requirements were not achieved during 236 days of the study period. Natural low flows are frequently below the flow reservations, but diversions resulted in flow reservations not being met a total of 140 days. Thirty-five algae species were identified from the sample collected at Indian River near Sitka while 24 species were identified from the sample collected at Indian River at Sitka. Most species of algae identified in the Indian River samples were diatoms and the majority were pinnate diatoms; however, green algae and (or) blue-green algae accounted for much of the algal biomass at the two sites. The trophic condition of the Indian River is oligotrophic, and algal productivity likely is limited by low concentrations of dissolved nitrogen. Few invertebrate taxa were collected relative to many high-quality streams in the contiguous United States, but the number of taxa in Indian River appears to be typical of Alaska streams. Ephemeroptera was the most abundant order sampled followed by Diptera.

Assessing changes to in-stream turbidity following construction of a forest road in West Virginia

Treesearch

Jingxin Wang; Pamela J. Edwards; William A. Goff

2011-01-01

Two forested headwater watersheds were monitored to examine changes to in-stream turbidity following the construction of a forest haul road. One watershed was used as an undisturbed reference, while the other had a 0.92-km (0.57-mi) haul road constructed in it. The channels in both are intermittent tributaries of the Left Fork of Clover Run in the Cheat River watershed...

Links between riparian landcover, instream environment and fish assemblages in headwater streams of south-eastern Brazil

USGS Publications Warehouse

Cruz, Bruna B.; Miranda, Leandro E.; Cetra, Mauricio

2013-01-01

We hypothesised and tested a hierarchical organisation model where riparian landcover would influence bank composition and light availability, which in turn would influence instream environments and control fish assemblages. The study was conducted during the dry season in 11 headwater tributaries of the Sorocaba River in the upper Paraná River Basin, south-eastern Brazil. We focused on seven environmental factors each represented by one or multiple environmental variables and seven fish functional traits each represented by two or more classes. Multivariate direct gradient analyses suggested that riparian zone landcover can be considered a higher level causal factor in a network of relations that control instream characteristics and fish assemblages. Our results provide a framework for a hierarchical conceptual model that identifies singular and collective influences of variables from different scales on each other and ultimately on different aspects related to stream fish functional composition. This conceptual model is focused on the relationships between riparian landcover and instream variables as causal factors on the organisation of stream fish assemblages. Our results can also be viewed as a model for headwater stream management in that landcover can be manipulated to influence factors such as bank composition, substrates and water quality, whereas fish assemblage composition can be used as indicators to monitor the success of such efforts.

Prediction of stream fish assemblages from land use characteristics: implications for cost-effective design of monitoring programmes.

PubMed

Kristensen, Esben Astrup; Baattrup-Pedersen, Annette; Andersen, Hans Estrup

2012-03-01

Increasing human impact on stream ecosystems has resulted in a growing need for tools helping managers to develop conservations strategies, and environmental monitoring is crucial for this development. This paper describes the development of models predicting the presence of fish assemblages in lowland streams using solely cost-effective GIS-derived land use variables. Three hundred thirty-five stream sites were separated into two groups based on size. Within each group, fish abundance data and cluster analysis were used to determine the composition of fish assemblages. The occurrence of assemblages was predicted using a dataset containing land use variables at three spatial scales (50 m riparian corridor, 500 m riparian corridor and the entire catchment) supplemented by a dataset on in-stream variables. The overall classification success varied between 66.1-81.1% and was only marginally better when using in-stream variables than when applying only GIS variables. Also, the prediction power of a model combining GIS and in-stream variables was only slightly better than prediction based solely on GIS variables. The possibility of obtaining precise predictions without using costly in-stream variables offers great potential in the design of monitoring programmes as the distribution of monitoring sites along a gradient in ecological quality can be done at a low cost.

Instream sand and gravel mining: Environmental issues and regulatory process in the United States

USGS Publications Warehouse

Meador, M.R.; Layher, A.O.

1998-01-01

Sand and gravel are widely used throughout the U.S. construction industry, but their extraction can significantly affect the physical, chemical, and biological characteristics of mined streams. Fisheries biologists often find themselves involved in the complex environmental and regulatory issues related to instream sand and gravel mining. This paper provides an overview of information presented in a symposium held at the 1997 midyear meeting of the Southern Division of the American Fisheries Society in San Antonio, Texas, to discuss environmental issues and regulatory procedures related to instream mining. Conclusions from the symposium suggest that complex physicochemical and biotic responses to disturbance such as channel incision and alteration of riparian vegetation ultimately determine the effects of instream mining. An understanding of geomorphic processes can provide insight into the effects of mining operations on stream function, and multidisciplinary empirical studies are needed to determine the relative effects of mining versus other natural and human-induced stream alterations. Mining regulations often result in a confusing regulatory process complicated, for example, by the role of the U.S. Army Corps of Engineers, which has undergone numerous changes and remains unclear. Dialogue among scientists, miners, and regulators can provide an important first step toward developing a plan that integrates biology and politics to protect aquatic resources.

How climate change will affect sessile stages of brown trout (Salmo trutta) in mountain streams of the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Santiago, José M.; Alonso, Carlos; García de Jalón, Diego; Solana, Joaquín

2017-04-01

Streamflow and temperature regimes are determinant for the availability of suitable physical habitat for instream biological communities. Iberian brown trout (Salmo trutta) populations live in a climatic border in which summer water scarcity and raising temperatures will compromise their viability throughout the current century. Due to their impaired mobility, sessile stages of trout life cycle (i.e. eggs and larvae) are among the most sensitive organisms to environmental changing conditions. At a given spawning redd, thermal habitat is limited by the length of the period at which suitable temperatures occur. At the same time, suitable physical habitat is limited by the instream flow regime during spawning and incubation of eggs and larvae. Temperature and flow do also interact, thus producing synergistic effects on both physical and thermal habitats. This study is aimed at quantitatively predicting thermal and physical habitat loss for the sessile stages of brown trout life cycle due to clime change, in mountain streams at the rear edge of the species natural distribution using high-resolution spatial-temporal simulations of the thermal and physical habitat. Two streams of Central Spain have been studied (Cega and Lozoya streams). Daily temperature and flow data from ad hoc downscaled IPCC (RCP4.5 and RCP8.5) predictions were used as input variables. Physical habitat changes were simulated from previously predicted stream flow data by means of hydraulic simulation tools (River2D). By taking into account the thermal tolerance limits and the proportion of lost physical habitat, limiting factors for the reproduction of brown trout in the study area were determined. The general increase of mean temperatures shortens the duration of the early developmental stages. This reduction of the sessile period is rather similar in both RCP4.5 and RCP8.5 scenarios by 2050. Differences between both scenarios become greater by 2099. The duration of sessile developmental is reduced in 12 days (-10%) according to scenario RCP4.5 and as much as 30 days (-25%) according to RCP8.5 in the Cega stream. Reduction of this sessile period in the Lozoya stream ranges between 14 days (-12%) in RCP4.5 and 35 (-29%) in RCP8.5. However, this acceleration of the development is not sufficient to compensate the much greater reduction of the thermal window in which mean water temperature remain below 10°C (considered a critical threshold). In the Cega stream, suitable thermal window reduction will range between 21% (RCP4.5) and 49% (RCP8.5) by 2099. In contrast, the Lozoya stream will lose much less time of suitable temperatures by 2099: 3% and 21%, according to RCP4.5 and RCP8.5, respectively. Although habitat reductions will be significant during the spawning season, the most important problems for trout population viability seem to be related to the reduction of the available time window for embryos and larvae to complete their development. Besides, due to the differential sensitivity of instream thermal habitat to a general increase in air temperature, it is highly recommendable to address locally adapted mitigation programs to avoid a general retraction of the current native range of this species.

A Potential Approach for Low Flow Selection in Water Resource Supply and Management

Treesearch

Ying Ouyang

2012-01-01

Low flow selections are essential to water resource management, water supply planning, and watershed ecosystem restoration. In this study, a new approach, namely the frequent-low (FL) approach (or frequent-low index), was developed based on the minimum frequent-low flow or level used in minimum flows and/or levels program in northeast Florida, USA. This FL approach was...

Developing user-friendly habitat suitability tools from regional stream fish survey data

USGS Publications Warehouse

Zorn, T.G.; Seelbach, P.; Wiley, M.J.

2011-01-01

We developed user-friendly fish habitat suitability tools (plots) for fishery managers in Michigan; these tools are based on driving habitat variables and fish population estimates for several hundred stream sites throughout the state. We generated contour plots to show patterns in fish biomass for over 60 common species (and for 120 species grouped at the family level) in relation to axes of catchment area and low-flow yield (90% exceedance flow divided by catchment area) and also in relation to axes of mean and weekly range of July temperatures. The plots showed distinct patterns in fish habitat suitability at each level of biological organization studied and were useful for quantitatively comparing river sites. We demonstrate how these plots can be used to support stream management, and we provide examples pertaining to resource assessment, trout stocking, angling regulations, chemical reclamation of marginal trout streams, indicator species, instream flow protection, and habitat restoration. These straightforward and effective tools are electronically available so that managers can easily access and incorporate them into decision protocols and presentations.

Evaluation of persistent hydrophobic organic compounds in the Columbia River Basin using semipermeable-membrane devices

USGS Publications Warehouse

McCarthy, K.A.; Gale, R.W.

2001-01-01

Persistent hydrophobic organic compounds are of concern in the Columbia River because they have been correlated with adverse effects on wildlife. We analysed samples from nine main-stem and six tributary sites throughout the Columbia River Basin (Washington and Oregon) for polychlorinated dibenzo-p-dioxins, dibenzofurans, polychlorinated biphenyls, organochlorine pesticides, and priority-pollutant polycyclic aromatic hydrocarbons. Because these compounds may have important biological consequences at aqueous concentrations well below the detection limits associated with conventional sampling methods, we used semipermeable-membrane devices to sample water and achieved parts-per-quintillion detection limits. All of these compound classes were prevalent within the basin, but concentrations of many analytes were highest in the vicinity of Portland-Vancouver, indicating that the Willamette subbasin-and perhaps the urban area in particular-is an important source of these compounds. Data collected during basin low-flow conditions in 1997 and again during basin high-flow conditions in 1998 indicate that in-stream processes such as dilution by relatively clean inflow, and flow through island hyporheic zones may be important mechanisms for attenuating dissolved concentrations of hydrophobic compounds.

Characterization of water quality in selected tributaries of the Alamosa River, southwestern Colorado, including comparisons to instream water-quality standards and toxicological reference values, 1995-97

USGS Publications Warehouse

Ortiz, Roderick F.; Ferguson, Sheryl A.

2001-01-01

A comprehensive water-quality sampling network was implemented by the U.S. Geological Survey from 1995 through 1997 at 12 tributary sites to the Alamosa River. The network was designed to address data gaps identified in the initial ecological risk assessment of the Summitville Superfund site. Tributaries draining hydrothermally altered areas had higher median values for nearly all measured properties and constituents than tributaries draining unaltered areas. Colorado instream standards for pH, copper, iron, and zinc were in attainment at most tributary sites. Instream standards for pH and chronic aquatic-life standards for iron were not attained in Jasper Creek. Toxicological reference values were most often exceeded at Iron Creek, Alum Creek, Bitter Creek, Wightman Fork, and Burnt Creek. These tributaries all drain hydrothermally altered areas.

In-stream production of methylmercury in a northern California river during summer baseflow

NASA Astrophysics Data System (ADS)

Tsui, M. T.; Finlay, J. C.; Nollet, Y. H.; Balogh, S. J.

2009-12-01

In stream ecosystems, it is well established that terrestrial landscape features such as wetlands are important in determining the aqueous concentration and flux of methylmercury. In contrast, our understanding of in-stream production of methylmercury is inadequate, especially on an ecosystem scale. In this study, we examined the relationship between the net production of dissolved methylmercury and algal metabolism in an 8-km reach of a third order stream (South Fork Eel River) in northern California. The stream has a forested watershed with no wetlands and has a long period of baseflow that typically extends from late May to early October. There was an intense rainfall in early May, 2009, but no major precipitation was recorded afterward, as is typical of Mediterranean climate of the study site. We collected surface water samples along the main channel and four major tributaries to the study stream reach. Temporal patterns of algal metabolism were inferred from net changes in total dissolved phosphorus and silica uptake and algal abundance. There was essentially no net production of methylmercury within the study reach (~ 0 µg Hg/km/d) in mid-May but net production of methylmercury occurred afterward when discharge declined exponentially, water temperature increased and algal metabolism increased (i.e. phosphorus and silica were taken up biologically). Net production of dissolved methylmercury peaked in mid-June (100 µg Hg/km/d) and then declined in mid-July (58 µg Hg/km/d) and mid-August (45 µg Hg/km/d) within the 8-km reach. The absence of surface runoff during the summer (e.g. June through September) indicates that the observed net production of methylmercury occurred within the channel and algal metabolism is coupled to the mercury methylation process. In summary, our study suggests that, in addition to watershed features, in-stream production of methylmercury should be considered as an important factor mediating mercury bioavailability in flowing waters especially during baseflow periods and in systems with high rates of algal productivity. Temporal changes of physicochemical properties of the study stream reach.

Confederated Tribes Umatilla Indian Reservation (CTUIR) Umatilla Anadromous Fisheries Habitat Project : A Columbia River Basin Fish Habitat Project : Annual Report Fiscal Year 2007.

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

Hoverson, Eric D.; Amonette, Alexandra

2008-12-02

The Umatilla Anadromous Fisheries Habitat Project (UAFHP) is an ongoing effort to protect, enhance, and restore riparian and instream habitat for the natural production of anadromous salmonids in the Umatilla River Basin, Northeast Oregon. Flow quantity, water temperature, passage, and lack of in-stream channel complexity have been identified as the key limiting factors in the basin. During the 2007 Fiscal Year (FY) reporting period (February 1, 2007-January 31, 2008) primary project activities focused on improving instream and riparian habitat complexity, migrational passage, and restoring natural channel morphology and floodplain function. Eight fisheries habitat enhancement projects were implemented on Meacham Creek,more » Camp Creek, Greasewood Creek, Birch Creek, West Birch Creek, and the Umatilla River. Specific restoration actions included: (1) rectifying five fish passage barriers on four creeks, (2) planting 1,275 saplings and seeding 130 pounds of native grasses, (3) constructing two miles of riparian fencing for livestock exclusion, (4) coordinating activities related to the installation of two off-channel, solar-powered watering areas for livestock, and (5) developing eight water gap access sites to reduce impacts from livestock. Baseline and ongoing monitoring and evaluation activities were also completed on major project areas such as conducting photo point monitoring strategies activities at the Meacham Creek Large Wood Implementation Project site (FY2006) and at all existing easements and planned project sites. Fish surveys and aquatic habitat inventories were conducted at project sites prior to implementation. Monitoring plans will continue throughout the life of each project to oversee progression and inspire timely managerial actions. Twenty-seven conservation easements were maintained with 23 landowners. Permitting applications for planned project activities and biological opinions were written and approved. Project activities were based on a variety of fisheries monitoring techniques and habitat assessments used to determine existing conditions and identify factors limiting anadromous salmonid abundance. Proper selection and implementation of the most effective site-specific habitat restoration plan, taking into consideration the unique characteristics of each project site, and conducted in cooperation with landowners and project partners, was of paramount importance to ensure each project's success.« less

Low volume flow meter

DOEpatents

Meixler, Lewis D.

1993-01-01

The low flow monitor provides a means for determining if a fluid flow meets a minimum threshold level of flow. The low flow monitor operates with a minimum of intrusion by the flow detection device into the flow. The electrical portion of the monitor is externally located with respect to the fluid stream which allows for repairs to the monitor without disrupting the flow. The electronics provide for the adjustment of the threshold level to meet the required conditions. The apparatus can be modified to provide an upper limit to the flow monitor by providing for a parallel electronic circuit which provides for a bracketing of the desired flow rate.

Optimization of memory use of fragment extension-based protein-ligand docking with an original fast minimum cost flow algorithm.

PubMed

Yanagisawa, Keisuke; Komine, Shunta; Kubota, Rikuto; Ohue, Masahito; Akiyama, Yutaka

2018-06-01

The need to accelerate large-scale protein-ligand docking in virtual screening against a huge compound database led researchers to propose a strategy that entails memorizing the evaluation result of the partial structure of a compound and reusing it to evaluate other compounds. However, the previous method required frequent disk accesses, resulting in insufficient acceleration. Thus, more efficient memory usage can be expected to lead to further acceleration, and optimal memory usage could be achieved by solving the minimum cost flow problem. In this research, we propose a fast algorithm for the minimum cost flow problem utilizing the characteristics of the graph generated for this problem as constraints. The proposed algorithm, which optimized memory usage, was approximately seven times faster compared to existing minimum cost flow algorithms. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Modeled intermittency risk for small streams in the Upper Colorado River Basin under climate change

USGS Publications Warehouse

Reynolds, Lindsay V.; Shafroth, Patrick B.; Poff, N. LeRoy

2015-01-01

Longer, drier summers projected for arid and semi-arid regions of western North America under climate change are likely to have enormous consequences for water resources and river-dependent ecosystems. Many climate change scenarios for this region involve decreases in mean annual streamflow, late summer precipitation and late-summer streamflow in the coming decades. Intermittent streams are already common in this region, and it is likely that minimum flows will decrease and some perennial streams will shift to intermittent flow under climate-driven changes in timing and magnitude of precipitation and runoff, combined with increases in temperature. To understand current intermittency among streams and analyze the potential for streams to shift from perennial to intermittent under a warmer climate, we analyzed historic flow records from streams in the Upper Colorado River Basin (UCRB). Approximately two-thirds of 115 gaged stream reaches included in our analysis are currently perennial and the rest have some degree of intermittency. Dry years with combinations of high temperatures and low precipitation were associated with more zero-flow days. Mean annual flow was positively related to minimum flows, suggesting that potential future declines in mean annual flows will correspond with declines in minimum flows. The most important landscape variables for predicting low flow metrics were precipitation, percent snow, potential evapotranspiration, soils, and drainage area. Perennial streams in the UCRB that have high minimum-flow variability and low mean flows are likely to be most susceptible to increasing streamflow intermittency in the future.

Science for Managing Riverine Ecosystems: Actions for the USGS Identified in the Workshop "Analysis of Flow and Habitat for Instream Aquatic Communities"

USGS Publications Warehouse

Bencala, Kenneth E.; Hamilton, David B.; Petersen, James H.

2006-01-01

Federal and state agencies need improved scientific analysis to support riverine ecosystem management. The ability of the USGS to integrate geologic, hydrologic, chemical, geographic, and biological data into new tools and models provides unparalleled opportunities to translate the best riverine science into useful approaches and usable information to address issues faced by river managers. In addition to this capability to provide integrated science, the USGS has a long history of providing long-term and nationwide information about natural resources. The USGS is now in a position to advance its ability to provide the scientific support for the management of riverine ecosystems. To address this need, the USGS held a listening session in Fort Collins, Colorado in April 2006. Goals of the workshop were to: 1) learn about the key resource issues facing DOI, other Federal, and state resource management agencies; 2) discuss new approaches and information needs for addressing these issues; and 3) outline a strategy for the USGS role in supporting riverine ecosystem management. Workshop discussions focused on key components of a USGS strategy: Communications, Synthesis, and Research. The workshop identified 3 priority actions the USGS can initiate now to advance its capabilities to support integrated science for resource managers in partner government agencies and non-governmental organizations: 1) Synthesize the existing science of riverine ecosystem processes to produce broadly applicable conceptual models, 2) Enhance selected ongoing instream flow projects with complementary interdisciplinary studies, and 3) Design a long-term, watershed-scale research program that will substantively reinvent riverine ecosystem science. In addition, topical discussion groups on hydrology, geomorphology, aquatic habitat and populations, and socio-economic analysis and negotiation identified eleven important complementary actions required to advance the state of the science and to develop the tools for supporting decisions on riverine ecosystem management. These eleven actions lie within the continuum of Communications, Synthesis, and Research.

Evaluating the accotink creek restoration project for improving water quality, in-stream habitat, and bank stability

USGS Publications Warehouse

Struck, S.D.; Selvakumar, A.; Hyer, K.; O'Connor, T.

2007-01-01

Increased urbanization results in a larger percentage of connected impervious areas and can contribute large quantities of stormwater runoff and significant quantities of debris and pollutants (e.g., litter, oils, microorganisms, sediments, nutrients, organic matter, and heavy metals) to receiving waters. To improve water quality in urban and suburban areas, watershed managers often incorporate best management practices (BMPs) to reduce the quantity of runoff as well as to minimize pollutants and other stressors contained in stormwater runoff. It is well known that land-use practices directly impact urban streams. Stream flows in urbanized watersheds increase in magnitude as a function of impervious area and can result in degradation of the natural stream channel morphology affecting the physical, chemical, and biological integrity of the stream. Stream bank erosion, which also increases with increased stream flows, can lead to bank instability, property loss, infrastructure damage, and increased sediment loading to the stream. Increased sediment loads may lead to water quality degradation downstream and have negative impacts on fish, benthic invertebrates, and other aquatic life. Accotink Creek is in the greater Chesapeake Bay and Potomac watersheds, which have strict sediment criteria. The USEPA (United States Environmental Protection Agency) and USGS (United States Geological Survey) are investigating the effectiveness of stream restoration techniques as a BMP to decrease sediment load and improve bank stability, biological integrity, and in-stream water quality in an impaired urban watershed in Fairfax, Virginia. This multi-year project continuously monitors turbidity, specific conductance, pH, and water temperature, as well as biological and chemical water quality parameters. In addition, physical parameters (e.g., pebble counts, longitudinal and cross sectional stream surveys) were measured to assess geomorphic changes associated with the restoration. Data from the pre-construction and initial post-construction phases are presented in this report. ?? 2007 ASCE.

Development and application of the microbial fate and transport module for the Agricultural Policy/Environmental eXtender (APEX) model

NASA Astrophysics Data System (ADS)

Hong, E.; Park, Y.; Muirhead, R.; Jeong, J.; Pachepsky, Y. A.

2017-12-01

Pathogenic microorganisms in recreational and irrigation waters remain the subject of concern. Water quality models are used to estimate microbial quality of water sources, to evaluate microbial contamination-related risks, to guide the microbial water quality monitoring, and to evaluate the effect of agricultural management on the microbial water quality. The Agricultural Policy/Environmental eXtender (APEX) is the watershed-scale water quality model that includes highly detailed representation of agricultural management. The APEX currently does not have microbial fate and transport simulation capabilities. The objective of this work was to develop the first APEX microbial fate and transport module that could use the APEX conceptual model of manure removal together with recently introduced conceptualizations of the in-stream microbial fate and transport. The module utilizes manure erosion rates found in the APEX. Bacteria survival in soil-manure mixing layer was simulated with the two-stage survival model. Individual survival patterns were simulated for each manure application date. Simulated in-stream microbial fate and transport processes included the reach-scale passive release of bacteria with resuspended bottom sediment during high flow events, the transport of bacteria from bottom sediment due to the hyporheic exchange during low flow periods, the deposition with settling sediment, and the two-stage survival. Default parameter values were available from recently published databases. The APEX model with the newly developed microbial fate and transport module was applied to simulate seven years of monitoring data for the Toenepi watershed in New Zealand. Based on calibration and testing results, the APEX with the microbe module reproduced well the monitored pattern of E. coli concentrations at the watershed outlet. The APEX with the microbial fate and transport module will be utilized for predicting microbial quality of water under various agricultural practices, evaluating monitoring protocols, and supporting the selection of management practices based on regulations that rely on fecal indicator bacteria concentrations.

Instream biological assessment of NPDES point source discharges at the Savannah River Site, 1997-1998

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

Specht, W.L.

2000-02-28

The Savannah River Site currently has 33 permitted NPDES outfalls that have been permitted by the South Carolina Department of Health an Environmental Control to discharge to SRS streams and the Savannah River. In order to determine the cumulative impacts of these discharges to the receiving streams, a study plan was developed to perform in-stream assessments of the fish assemblages, macroinvertebrate assemblages, and habitats of the receiving streams.

Establishing Minimum Flow Requirements Based on Benthic Vegetation: What are Some Issues Related to Identifying Quantity of Inflow and Tools Used to Quantify Ecosystem Response?

NASA Astrophysics Data System (ADS)

Hunt, M. J.; Nuttle, W. K.; Cosby, B. J.; Marshall, F. E.

2005-05-01

Establishing minimum flow requirements in aquatic ecosystems is one way to stipulate controls on water withdrawals in a watershed. The basis of the determination is to identify the amount of flow needed to sustain a threshold ecological function. To develop minimum flow criteria an understanding of ecological response in relation to flow is essential. Several steps are needed including: (1) identification of important resources and ecological functions, (2) compilation of available information, (3) determination of historical conditions, (4) establishment of technical relationships between inflow and resources, and (5) identification of numeric criteria that reflect the threshold at which resources are harmed. The process is interdisciplinary requiring the integration of hydrologic and ecologic principles with quantitative assessments. The tools used quantify the ecological response and key questions related to how the quantity of flow influences the ecosystem are examined by comparing minimum flow determination in two different aquatic systems in South Florida. Each system is characterized by substantial hydrologic alteration. The first, the Caloosahatchee River is a riverine system, located on the southwest coast of Florida. The second, the Everglades- Florida Bay ecotone, is a wetland mangrove ecosystem, located on the southern tip of the Florida peninsula. In both cases freshwater submerged aquatic vegetation (Vallisneria americana or Ruppia maritima), located in areas of the saltwater- freshwater interface has been identified as a basis for minimum flow criteria. The integration of field studies, laboratory studies, and literature review was required. From this information we developed ecological modeling tools to quantify and predict plant growth in response to varying environmental variables. Coupled with hydrologic modeling tools questions relating to the quantity and timing of flow and ecological consequences in relation to normal variability are addressed.

Mechanical Analyses for coupled Vegetation-Flow System

NASA Astrophysics Data System (ADS)

Chen, L.; Acharya, K.; Stone, M.

2010-12-01

Vegetation in riparian areas plays important roles in hydrology, geomorphology and ecology in local environment. Mechanical response of the aquatic vegetation to hydraulic forces and its impact on flow hydraulics have received considerable attention due to implications for flood control, habitat restoration, and water resources management. This study aims to advance understanding of the mechanical properties of in-stream vegetation including drag force, moment and stress. Dynamic changes of these properties under various flow conditions largely determine vegetation affected flow field and dynamic resistance with progressive bending, and hydraulic conditions for vegetation failure (rupture or wash-out) thus are critical for understanding the coupled vegetation-flow system. A new approach combining fluid and material mechanics is developed in this study to examine the behavior of both rigid and flexible vegetation. The major advantage of this approach is its capability to treat large deflection (bending) of plants and associated changes of mechanical properties in both vegetation and flow. Starting from simple emergent vegetation, both static and dynamic formulations of the problem are presented and the solutions are compared. Results show the dynamic behavior of a simplified system mimicking complex and real systems, implying the approach is able to disclose the physical essence of the coupled system. The approach is extended to complex vegetation under both submerged and emergent conditions using more realistic representation of biomechanical properties for vegetation.

Instream Attenuation of Nitrogen and Phosphorus in Non-Point Source Dominated Streams: Hydrologic and Biogeochemical Controls

NASA Astrophysics Data System (ADS)

Bray, E. N.; Chen, X.; Keller, A. A.

2010-12-01

Non-point source inputs of total nitrogen (TN) and total phosphorus (TP) in rivers are the leading causes of water quality degradation in the United States (Turner and Rabalais, 2003; Broussard and Turner, 2009). Yet it remains a challenge to adequately quantify the relative role and influence of physical hydrological processes versus biogeochemical processes on the attenuation of TN and TP for individual river reaches. A watershed-scale study of instream dynamics and attenuation of TN and TP in northeastern U.S. headwater streams demonstrates that physical and hydrological processes exert greater control over nutrient removal than biogeochemical processes. To explore these interactions under various attenuation scenarios, we developed the watershed-scale model (WARMF) for 97 catchments to simulate watershed processes, hydrology, and diffuse source loads of nutrients. We simulated a hypothetical nutrient release at a rate of 1 kg/d of TN (50% as ammonium and 50% as nitrate) and TP (100% as phosphate) to predict response lengths of downstream catchments. Resulting attenuation factors are presented as the change in mean load at a given location, normalized to the change in the catchment in which the load is applied. Results indicate that for most catchments, the TN and TP load increase is attenuated from the stream within a few tens of kilometers. Fifty percent attenuation occurs across length scales ranging from a few hundreds of meters to kilometers if the load is introduced in the headwaters, indicating the most rapid nutrient removal occurs in the smallest headwater streams but generally decreases with distance downstream. There are some differences in the attenuation factors for TN and TP, although the pattern of attenuation is the same. Sensitivity analyses highlight five hydrological parameters of paramount importance to concentrations of N and P, namely precipitation, evaporation coefficients (magnitude and skewness), soil layer thickness, soil saturated moisture and soil hydraulic conductivity. These model parameters have a significant effect on the concentrations of nutrients, with TN exhibiting greater sensitivity. Further, attenuation results suggest that stream depth, flow regime, and density of agriculture in small headwater streams are potentially important controls to nutrient uptake and removal; i.e. during periods of low flow, dilution is reduced, attenuation length increases, and removal processes may be dominated by settling as opposed to biogeochemistry. Instream attenuation and model results can be used to assess 1) the scale and nature of best management practices which must be adopted to result in nutrient reductions, 2) the downstream distance at which load reductions will be effective, and 3) the hydrological characteristics of the river network which exert considerable influence on attenuation lengths and nutrient removal.

Instream wood in a steep headwater channel: geomorphic significance of large and small wood

NASA Astrophysics Data System (ADS)

Galia, Tomáš; Šilhán, Karel; Ruiz-Villanueva, Virginia; Tichavský, Radek

2016-04-01

Besides the well-known significance of large wood (LW), also small woody pieces (SW; here defined as pieces with dimensions at least 0.5 m length and 0.05 m diameter), can play an important role in steep narrow headwaters. We inventoried instream wood in the 0.4 km long Mazák headwater channel, Moravskoslezské Beskydy Mts, Czech Republic (2

Walla Walla River Fish Passage Operations Program, 2000-2001 Annual Report.

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

Zimmerman, Brian C.; Duke, Bill B.

2004-02-01

In the late 1990's, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate migration conditions in the basin. The migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow measures, and initiating trap and haul efforts. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survival of migrating adultmore » and juvenile salmonids in the basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage criteria and passage and trapping facility design and operation. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. During the 2000-2001 project year, there were 624 summer steelhead (Oncorhynchus mykiss), 24 bull trout (Salvelinus confluentus), and 47 spring chinook (O. tshawytscha) counted at the Nursery Bridge Dam adult trap between December 27, 2000 and June 7, 2001. The Little Walla Walla River juvenile trap was not operated this year. The project transported 1600 adult spring chinook from Ringold Springs Hatchery to the South Fork Walla Walla Brood Holding Facility and outplanted 1156 for natural spawning in the basin. The project also provided equipment for transportation of juveniles captured during the construction fish salvage at Nursery Bridge Dam.« less

On-Site Incineration of Contaminated Soil: A Study into U.S. Navy Applications

DTIC Science & Technology

1991-08-01

venturi scrubber Minimum water flow rate and p1l to absorber Minimum water/alkaline reagent flow to dry scrubber Minimum particulate scrubber blowdown...remove hydrochloric acid and sulfur dioxide from flue gases using, for example, wet scrubbers and limestone adsorption towers, respectively. Modified...Reagent preparation 8) Bllending 26) Fugitive emission control 9) Pretreatment 27) Scrubber liquid cooling 10) Blended and pretreated solid waste

From Drought to Flood: Biological Responses of Large River Salmonids and Emergent Management Challenges Under California's Extreme Hydroclimatic Variability

NASA Astrophysics Data System (ADS)

Anderson, C.

2017-12-01

California's hydroclimatic regime is characterized by extreme interannual variability including periodic, multi-year droughts and winter flooding sequences. Statewide, water years 2012-2016 were characterized by extreme drought followed by likely one of the wettest years on record in water year 2017. Similar drought-flood patterns have occurred multiple times both in the contemporary empirical record and reconstructed climate records. Both the extreme magnitude and rapid succession of these hydroclimatic periods pose difficult challenges for water managers and regulatory agencies responsible for providing instream flows to protect and recover threatened and endangered fish species. Principal among these riverine fish species are federally listed winter-run and spring-run Chinook salmon (Oncorhynchus tshawytscha), Central Valley steelhead (Oncorhynchus mykiss), and the pelagic species Delta smelt (Hypomesus transpacificus). Poor instream conditions from 2012-2016 resulted in extremely low abundance estimates and poor overall fish health, and while fish monitoring results from water year 2017 are too preliminary to draw substantive conclusions, early indicators show continued downward population trends despite the historically wet conditions. This poster evaluates California's hydroclimatic conditions over the past decade and quantifies resultant impacts of the 2012-2016 drought and the extremely wet 2017 water year to both adult escapement and juvenile production estimates in California's major inland salmon rivers over that same time span. We will also examine local, state, and federal regulatory actions both in response to the extreme hydroclimatic variability and in preparation for future drought-flood sequences.

Exploring spatiotemporal changes of the Yangtze River (Changjiang) nitrogen and phosphorus sources, retention and export to the East China Sea and Yellow Sea.

PubMed

Liu, Xiaochen; Beusen, Arthur H W; Van Beek, Ludovicus P H; Mogollón, José M; Ran, Xiangbin; Bouwman, Alexander F

2018-06-04

Nitrogen (N) and phosphorus (P) flows from land to sea in the Yangtze River basin were simulated for the period 1900-2010, by combining models for hydrology, nutrient input to surface water, and an in-stream retention. This study reveals that the basin-wide nutrient budget, delivery to surface water, and in-stream retention increased during this period. Since 2004, the Three Gorges Reservoir has contributed 5% and 7% of N and P basin-wide retention, respectively. With the dramatic rise in nutrient delivery, even this additional retention was insufficient to prevent an increase of riverine export from 337 Gg N yr -1 and 58 Gg P yr -1 (N:P molar ratio = 13) to 5896 Gg N yr -1 and 381 Gg P yr -1 (N:P molar ratio = 35) to the East China Sea and Yellow Sea (ECSYS). The midstream and upstream subbasins dominate the N and P exports to the ECSYS, respectively, due to various human activities along the river. Our spatially explicit nutrient source allocation can aid in the strategic targeting of nutrient reduction policies. We posit that these should focus on improving the agricultural fertilizer and manure use efficiency in the upstream and midstream and better urban wastewater management in the downstream subbasin. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Aeroacoustic and aerodynamic applications of the theory of nonequilibrium thermodynamics

NASA Technical Reports Server (NTRS)

Horne, W. Clifton; Smith, Charles A.; Karamcheti, Krishnamurty

1991-01-01

Recent developments in the field of nonequilibrium thermodynamics associated with viscous flows are examined and related to developments to the understanding of specific phenomena in aerodynamics and aeroacoustics. A key element of the nonequilibrium theory is the principle of minimum entropy production rate for steady dissipative processes near equilibrium, and variational calculus is used to apply this principle to several examples of viscous flow. A review of nonequilibrium thermodynamics and its role in fluid motion are presented. Several formulations are presented of the local entropy production rate and the local energy dissipation rate, two quantities that are of central importance to the theory. These expressions and the principle of minimum entropy production rate for steady viscous flows are used to identify parallel-wall channel flow and irrotational flow as having minimally dissipative velocity distributions. Features of irrotational, steady, viscous flow near an airfoil, such as the effect of trailing-edge radius on circulation, are also found to be compatible with the minimum principle. Finally, the minimum principle is used to interpret the stability of infinitesimal and finite amplitude disturbances in an initially laminar, parallel shear flow, with results that are consistent with experiment and linearized hydrodynamic stability theory. These results suggest that a thermodynamic approach may be useful in unifying the understanding of many diverse phenomena in aerodynamics and aeroacoustics.

Research on configuration of railway self-equipped tanker based on minimum cost maximum flow model

NASA Astrophysics Data System (ADS)

Yang, Yuefang; Gan, Chunhui; Shen, Tingting

2017-05-01

In the study of the configuration of the tanker of chemical logistics park, the minimum cost maximum flow model is adopted. Firstly, the transport capacity of the park loading and unloading area and the transportation demand of the dangerous goods are taken as the constraint condition of the model; then the transport arc capacity, the transport arc flow and the transport arc edge weight are determined in the transportation network diagram; finally, the software calculations. The calculation results show that the configuration issue of the tankers can be effectively solved by the minimum cost maximum flow model, which has theoretical and practical application value for tanker management of railway transportation of dangerous goods in the chemical logistics park.

1992 Columbia River Salmon Flow Measures Options Analysis/EIS.

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

Not Available

1992-01-01

This Options Analysis/Environmental Impact Statement (OA/EIS) identifies, presents effects of, and evaluates the potential options for changing instream flow levels in efforts to increase salmon populations in the lower Columbia and Snake rivers. The potential actions would be implemented during 1992 to benefit juvenile and adult salmon during migration through eight run-of-river reservoirs. The Corps of Engineers (Corps) prepared this document in cooperation with the Bonneville Power Administration and the Bureau of Reclamation. The US Fish and Wildlife Service (FSWS) is a participating agency. The text and appendices of the document describe the characteristics of 10 Federal projects and onemore » private water development project in the Columbia River drainage basin. Present and potential operation of these projects and their effects on the salmon that spawn and rear in the Columbia and Snake River System are presented. The life history, status, and response of Pacific salmon to current environmental conditions are described.« less

Modeling water quality, temperature, and flow in Link River, south-central Oregon

USGS Publications Warehouse

Sullivan, Annett B.; Rounds, Stewart A.

2016-09-09

The 2.1-km (1.3-mi) Link River connects Upper Klamath Lake to the Klamath River in south-central Oregon. A CE-QUAL-W2 flow and water-quality model of Link River was developed to provide a connection between an existing model of the upper Klamath River and any existing or future models of Upper Klamath Lake. Water-quality sampling at six locations in Link River was done during 2013–15 to support model development and to provide a better understanding of instream biogeochemical processes. The short reach and high velocities in Link River resulted in fast travel times and limited water-quality transformations, except for dissolved oxygen. Reaeration through the reach, especially at the falls in Link River, was particularly important in moderating dissolved oxygen concentrations that at times entered the reach at Link River Dam with marked supersaturation or subsaturation. This reaeration resulted in concentrations closer to saturation downstream at the mouth of Link River.

White sturgeon spawning and rearing habitat in the lower Columbia River

USGS Publications Warehouse

Parsley, Michael J.; Beckman, Lance G.

1994-01-01

Estimates of spawning habitat for white sturgeons Acipenser transmontanus in the tailraces of the four dams on the lower 470 km of the Columbia River were obtained by using the Physical Habitat Simulation System of the U.S. Fish and Wildlife Service's Instream Flow Incremental Methodology to identify areas with suitable water depths, water velocities, and substrates. Rearing habitat throughout the lower Columbia River was assessed by using a geographic information system to identify areas with suitable water depths and substrates. The lowering of spring and summer river discharges from hydropower system operation reduces the availability of spawning habitat for white sturgeons. The four dam tailraces in the study area differ in the amount and quality of spawning habitat available at various discharges; the differences are due to channel morphology. The three impoundments and the free-flowing Columbia River downstream from Bonneville Dam provide extensive areas that are physically suitable for rearing young-of-the-year and juvenile white sturgeons.

Contributions of Phosphorus from Groundwater to Streams in the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces, Eastern United States

USGS Publications Warehouse

Denver, Judith M.; Cravotta,, Charles A.; Ator, Scott W.; Lindsey, Bruce D.

2011-01-01

Phosphorus from natural and human sources is likely to be discharged from groundwater to streams in certain geochemical environments. Water-quality data collected from 1991 through 2007 in paired networks of groundwater and streams in different hydrogeologic and land-use settings of the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces in the eastern United States were compiled and analyzed to evaluate the sources, fate, and transport of phosphorus. The median concentrations of phosphate in groundwater from the crystalline and siliciclastic bedrock settings (0.017 and 0.020 milligrams per liter, respectively) generally were greater than the median for the carbonate setting (less than 0.01 milligrams per liter). In contrast, the median concentrations of dissolved phosphate in stream base flow from the crystalline and siliciclastic bedrock settings (0.010 and 0.014 milligrams per liter, respectively) were less than the median concentration for base-flow samples from the carbonate setting (0.020 milligrams per liter). Concentrations of phosphorus in many of the stream base-flow and groundwater samples exceeded ecological criteria for streams in the region. Mineral dissolution was identified as the dominant source of phosphorus in the groundwater and stream base flow draining crystalline or siliciclastic bedrock in the study area. Low concentrations of dissolved phosphorus in groundwater from carbonate bedrock result from the precipitation of minerals and (or) from sorption to mineral surfaces along groundwater flow paths. Phosphorus concentrations are commonly elevated in stream base flow in areas underlain by carbonate bedrock, however, presumably derived from in-stream sources or from upland anthropogenic sources and transported along short, shallow groundwater flow paths. Dissolved phosphate concentrations in groundwater were correlated positively with concentrations of silica and sodium, and negatively with alkalinity and concentrations of calcium, magnesium, chloride, nitrate, sulfate, iron, and aluminum. These associations can result from the dissolution of alkali feldspars containing phosphorus; the precipitation of apatite; the precipitation of calcite, iron hydroxide, and aluminum hydroxide with associated sorption of phosphate ions; and the potential for release of phosphate from iron-hydroxide and other iron minerals under reducing conditions. Anthropogenic sources of phosphate such as fertilizer and manure and processes such as biological uptake, evapotranspiration, and dilution also affect phosphorus concentrations. The phosphate concentrations in surface water were not correlated with the silica concentration, but were positively correlated with concentrations of major cations and anions, including chloride and nitrate, which could indicate anthropogenic sources and effects of evapotranspiration on surface-water quality. Mixing of older, mineralized groundwater with younger, less mineralized, but contaminated groundwater was identified as a critical factor affecting the quality of stream base flow. In-stream processing of nutrients by biological processes also likely increases the phosphorus concentration in surface waters. Potential geologic contributions of phosphorus to groundwater and streams may be an important watershed-management consideration in certain hydrogeologic and geochemical environments. Geochemical controls effectively limit phosphorus transport through groundwater to streams in areas underlain by carbonate rocks; however, in crystalline and siliciclastic settings, phosphorus from mineral or human sources may be effectively transported by groundwater and contribute a substantial fraction to base-flow stream loads.

Physical habitat classification and instream flow modeling to determine habitat availability during low-flow periods, North Fork Shenandoah River, Virginia

USGS Publications Warehouse

Krstolic, Jennifer L.; Hayes, Donald C.; Ruhl, Peter M.

2006-01-01

Increasing development and increasing water withdrawals for public, industrial, and agricultural water supply threaten to reduce streamflows in the Shenandoah River basin in Virginia. Water managers need more information to balance human water-supply needs with the daily streamflows necessary for maintaining the aquatic ecosystems. To meet the need for comprehensive information on hydrology, water supply, and instream-flow requirements of the Shenandoah River basin, the U.S. Geological Survey and the Northern Shenandoah Valley Regional Commission conducted a cooperative investigation of habitat availability during low-flow periods on the North Fork Shenandoah River. Historic streamflow data and empirical data on physical habitat, river hydraulics, fish community structure, and recreation were used to develop a physical habitat simulation model. Hydraulic measurements were made during low, medium, and high flows in six reaches at a total of 36 transects that included riffles, runs, and pools, and that had a variety of substrates and cover types. Habitat suitability criteria for fish were developed from detailed fish-community sampling and microhabitat observations. Fish were grouped into four guilds of species and life stages with similar habitat requirements. Simulated habitat was considered in the context of seasonal flow regimes to show the availability of flows that sustain suitable habitat during months when precipitation and streamflow are scarce. The North Fork Shenandoah River basin was divided into three management sections for analysis purposes: the upper section, middle section, and lower section. The months of July, August, and September were chosen to represent a low-flow period in the basin with low mean monthly flows, low precipitation, high temperatures, and high water withdrawals. Exceedance flows calculated from the combined data from these three months describe low-flow periods on the North Fork Shenandoah River. Long-term records from three streamflow-gaging stations were used to characterize the flow regime: North Fork Shenandoah River at Cootes Store, Va. (1925-2002), North Fork Shenandoah River at Mount Jackson, Va. (1943-2002), and North Fork Shenandoah River near Strasburg, Va. (1925-2002). The predominant mesohabitat types (14 percent riffle, 67.3 percent run, and 18.7 percent pool) were classified along the entire river (100 miles) to assist in the selection of reaches for hydraulic and fish community data collection. The upper section has predominantly particle substrate, ranging in size from sand to boulders, and the shortest habitat units. The middle section is a transitional section with increased bedrock substrate and habitat unit length. The lower section has predominantly bedrock substrate and the longest habitat units in the river. The model simulations show that weighted usable-habitat area in the upper management section is highest at flows higher than the 25-percent exceedance flow for July, August, and September. During these three months, total weighted usable-habitat area in this section is often less than the simulated maximum weighted usable-habitat area. Habitat area in the middle management section is highest at flows between the 25- and 75-percent exceedance flows for July, August, and September. In the middle section during these months, both the actual weighted usable-habitat area and the simulated maximum weighted usable-habitat area are associated with this flow range. Weighted usable-habitat area in the lower management section is highest at flows lower than the 75-percent exceedance flow for July, August, and September. In the lower section during these three months, some weighted usable-habitat area is available, but the normal range of flows does not include the simulated maximum weighted usable-habitat area. A time-series habitat analysis associated with the historic streamflow, zero water withdrawals, and doubled water withdrawals was completed. During s

Effective Discharge and Annual Sediment Yield on Brazos River

NASA Astrophysics Data System (ADS)

Rouhnia, M.; Salehi, M.; Keyvani, A.; Ma, F.; Strom, K. B.; Raphelt, N.

2012-12-01

Geometry of an alluvial river alters dynamically over the time due to the sediment mobilization on the banks and bottom of the river channel in various flow rates. Many researchers tried to define a single representative discharge for these morphological processes such as "bank-full discharge", "effective discharge" and "channel forming discharge". Effective discharge is the flow rate in which, the most sediment load is being carried by water, in a long term period. This project is aimed to develop effective discharge estimates for six gaging stations along the Brazos River from Waco, TX to Rosharon, TX. The project was performed with cooperation of the In-stream Flow Team of the Texas Water Development Board (TWDB). Project objectives are listed as: 1) developing "Flow Duration Curves" for six stations based on mean-daily discharge by downloading the required, additional data from U.S Geological Survey website, 2) developing "Rating Curves" for six gaging stations after sampling and field measurements in three different flow conditions, 3) developing a smooth shaped "Sediment Yield Histogram" with a well distinguished peak as effective discharge. The effective discharge was calculated using two methods of manually and automatic bin selection. The automatic method is based on kernel density approximation. Cross-sectional geometry measurements, particle size distributions and water field samples were processed in the laboratory to obtain the suspended sediment concentration associated with flow rate. Rating curves showed acceptable trends, as the greater flow rate we experienced, the more sediment were carried by water.

The constructal law of design and evolution in nature

PubMed Central

Bejan, Adrian; Lorente, Sylvie

2010-01-01

Constructal theory is the view that (i) the generation of images of design (pattern, rhythm) in nature is a phenomenon of physics and (ii) this phenomenon is covered by a principle (the constructal law): ‘for a finite-size flow system to persist in time (to live) it must evolve such that it provides greater and greater access to the currents that flow through it’. This law is about the necessity of design to occur, and about the time direction of the phenomenon: the tape of the design evolution ‘movie’ runs such that existing configurations are replaced by globally easier flowing configurations. The constructal law has two useful sides: the prediction of natural phenomena and the strategic engineering of novel architectures, based on the constructal law, i.e. not by mimicking nature. We show that the emergence of scaling laws in inanimate (geophysical) flow systems is the same phenomenon as the emergence of allometric laws in animate (biological) flow systems. Examples are lung design, animal locomotion, vegetation, river basins, turbulent flow structure, self-lubrication and natural multi-scale porous media. This article outlines the place of the constructal law as a self-standing law in physics, which covers all the ad hoc (and contradictory) statements of optimality such as minimum entropy generation, maximum entropy generation, minimum flow resistance, maximum flow resistance, minimum time, minimum weight, uniform maximum stresses and characteristic organ sizes. Nature is configured to flow and move as a conglomerate of ‘engine and brake’ designs. PMID:20368252

The constructal law of design and evolution in nature.

PubMed

Bejan, Adrian; Lorente, Sylvie

2010-05-12

Constructal theory is the view that (i) the generation of images of design (pattern, rhythm) in nature is a phenomenon of physics and (ii) this phenomenon is covered by a principle (the constructal law): 'for a finite-size flow system to persist in time (to live) it must evolve such that it provides greater and greater access to the currents that flow through it'. This law is about the necessity of design to occur, and about the time direction of the phenomenon: the tape of the design evolution 'movie' runs such that existing configurations are replaced by globally easier flowing configurations. The constructal law has two useful sides: the prediction of natural phenomena and the strategic engineering of novel architectures, based on the constructal law, i.e. not by mimicking nature. We show that the emergence of scaling laws in inanimate (geophysical) flow systems is the same phenomenon as the emergence of allometric laws in animate (biological) flow systems. Examples are lung design, animal locomotion, vegetation, river basins, turbulent flow structure, self-lubrication and natural multi-scale porous media. This article outlines the place of the constructal law as a self-standing law in physics, which covers all the ad hoc (and contradictory) statements of optimality such as minimum entropy generation, maximum entropy generation, minimum flow resistance, maximum flow resistance, minimum time, minimum weight, uniform maximum stresses and characteristic organ sizes. Nature is configured to flow and move as a conglomerate of 'engine and brake' designs.

Estimated water use, by county, in North Carolina, 1990

USGS Publications Warehouse

Terziotti, Silvia; Schrader, Tony P.; Treece, M.W.

1994-01-01

Data on water use in North Carolina were compiled for 1990 as part of a cooperative agreement between the U.S. Geological Survey and the Division of Water Resources of the North Carolina Department of Environment, Health, and Natural Resources. Data were compiled from a number of Federal, State, and private sources for the offstream water-use categories of public supply, domestic, commercial, industrial, mining, livestock, irrigation, and thermoelectric-power generation. Data also were collected for instream use from hydroelectric facilities. Total estimated offstream water use in the State for 1990 was about 8,940 million gallons per day. About 95 percent of the water withdrawn was from surface-water sources. Thermoelectric-power generation accounted for about 81 percent of all withdrawals. Data for instream water use for hydroelectric-power generation also were compiled. This instream water use totaled about 66,900 million gallons per day. eAch water-use category is summarized in this report by county and source of water supply.

Source Apportionment of Suspended Sediment Sources using 137Cs and 210Pbxs

NASA Astrophysics Data System (ADS)

Lamba, J.; Karthikeyan, K.; Thompson, A.

2017-12-01

A study was conducted in the Pleasant Valley Watershed (50 km 2) in South Central Wisconsin to better understand sediment transport processes using sediment fingerprinting technique. Previous studies conducted in this watershed showed that resuspension of fine sediment deposited on the stream bed is an important source of suspended sediment. To better understand the role of fine sediment deposited on the stream bed, fallout radionuclides,137Cs and 210Pbxs were used to determine relative contribution to suspended sediment from in-stream (stream bank and stream bed) and upland sediment sources. Suspended sediment samples were collected during the crop growing season. Potential sources of suspended sediment considered in this study included cropland, pasture and in-stream (stream bed and stream bank). Suspended sediment sources were determined at a subwatershed level. Results of this study showed that in-stream sediment sources are important sources of suspended sediment. Future research should be conducted to better understand the role of legacy sediment in watershed-level sediment transport processes.

Low-flow characteristics of streams in South Carolina

USGS Publications Warehouse

Feaster, Toby D.; Guimaraes, Wladmir B.

2017-09-22

An ongoing understanding of streamflow characteristics of the rivers and streams in South Carolina is important for the protection and preservation of the State’s water resources. Information concerning the low-flow characteristics of streams is especially important during critical flow periods, such as during the historic droughts that South Carolina has experienced in the past few decades.Between 2008 and 2016, the U.S. Geological Survey, in cooperation with the South Carolina Department of Health and Environmental Control, updated low-flow statistics at 106 continuous-record streamgages operated by the U.S. Geological Survey for the eight major river basins in South Carolina. The low-flow frequency statistics included the annual minimum 1-, 3-, 7-, 14-, 30-, 60-, and 90-day mean flows with recurrence intervals of 2, 5, 10, 20, 30, and 50 years, depending on the length of record available at the streamflow-gaging station. Computations of daily mean flow durations for the 5-, 10-, 25-, 50-, 75-, 90-, and 95-percent probability of exceedance also were included.This report summarizes the findings from publications generated during the 2008 to 2016 investigations. Trend analyses for the annual minimum 7-day average flows are provided as well as trend assessments of long-term annual precipitation data. Statewide variability in the annual minimum 7-day average flow is assessed at eight long-term (record lengths from 55 to 78 years) streamgages. If previous low-flow statistics were available, comparisons with the updated annual minimum 7-day average flow, having a 10-year recurrence interval, were made. In addition, methods for estimating low-flow statistics at ungaged locations near a gaged location are described.

A neighborhood statistics model for predicting stream pathogen indicator levels.

PubMed

Pandey, Pramod K; Pasternack, Gregory B; Majumder, Mahbubul; Soupir, Michelle L; Kaiser, Mark S

2015-03-01

Because elevated levels of water-borne Escherichia coli in streams are a leading cause of water quality impairments in the U.S., water-quality managers need tools for predicting aqueous E. coli levels. Presently, E. coli levels may be predicted using complex mechanistic models that have a high degree of unchecked uncertainty or simpler statistical models. To assess spatio-temporal patterns of instream E. coli levels, herein we measured E. coli, a pathogen indicator, at 16 sites (at four different times) within the Squaw Creek watershed, Iowa, and subsequently, the Markov Random Field model was exploited to develop a neighborhood statistics model for predicting instream E. coli levels. Two observed covariates, local water temperature (degrees Celsius) and mean cross-sectional depth (meters), were used as inputs to the model. Predictions of E. coli levels in the water column were compared with independent observational data collected from 16 in-stream locations. The results revealed that spatio-temporal averages of predicted and observed E. coli levels were extremely close. Approximately 66 % of individual predicted E. coli concentrations were within a factor of 2 of the observed values. In only one event, the difference between prediction and observation was beyond one order of magnitude. The mean of all predicted values at 16 locations was approximately 1 % higher than the mean of the observed values. The approach presented here will be useful while assessing instream contaminations such as pathogen/pathogen indicator levels at the watershed scale.

Definition of hydraulic stability of KVGM-100 hot-water boiler and minimum water flow rate

NASA Astrophysics Data System (ADS)

Belov, A. A.; Ozerov, A. N.; Usikov, N. V.; Shkondin, I. A.

2016-08-01

In domestic power engineering, the methods of quantitative and qualitative-quantitative adjusting the load of the heat supply systems are widely distributed; furthermore, during the greater part of the heating period, the actual discharge of network water is less than estimated values when changing to quantitative adjustment. Hence, the hydraulic circuits of hot-water boilers should ensure the water velocities, minimizing the scale formation and excluding the formation of stagnant zones. The results of the calculations of hot-water KVGM-100 boiler and minimum water flow rate for the basic and peak modes at the fulfillment of condition of the lack of surface boil are presented in the article. The minimal flow rates of water at its underheating to the saturation state and the thermal flows in the furnace chamber were defined. The boiler hydraulic calculation was performed using the "Hydraulic" program, and the analysis of permissible and actual velocities of the water movement in the pipes of the heating surfaces was carried out. Based on the thermal calculations of furnace chamber and thermal- hydraulic calculations of heating surfaces, the following conclusions were drawn: the minimum velocity of water movement (by condition of boiling surface) at lifting movement of environment increases from 0.64 to 0.79 m/s; it increases from 1.14 to 1.38 m/s at down movement of environmental; the minimum water flow rate by the boiler in the basic mode (by condition of the surface boiling) increased from 887 t/h at the load of 20% up to 1074 t/h at the load of 100%. The minimum flow rate is 1074 t/h at nominal load and is achieved at the pressure at the boiler outlet equal to 1.1 MPa; the minimum water flow rate by the boiler in the peak mode by condition of surface boiling increases from 1669 t/h at the load of 20% up to 2021 t/h at the load of 100%.

14 CFR 121.335 - Equipment standards.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Equipment standards. (a) Reciprocating engine powered airplanes. The oxygen apparatus, the minimum rates of oxygen flow, and the supply of oxygen necessary to comply with § 121.327 must meet the standards...) Turbine engine powered airplanes. The oxygen apparatus, the minimum rate of oxygen flow, and the supply of...

14 CFR 121.335 - Equipment standards.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Equipment standards. (a) Reciprocating engine powered airplanes. The oxygen apparatus, the minimum rates of oxygen flow, and the supply of oxygen necessary to comply with § 121.327 must meet the standards...) Turbine engine powered airplanes. The oxygen apparatus, the minimum rate of oxygen flow, and the supply of...

14 CFR 121.335 - Equipment standards.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Equipment standards. (a) Reciprocating engine powered airplanes. The oxygen apparatus, the minimum rates of oxygen flow, and the supply of oxygen necessary to comply with § 121.327 must meet the standards...) Turbine engine powered airplanes. The oxygen apparatus, the minimum rate of oxygen flow, and the supply of...

14 CFR 121.335 - Equipment standards.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Equipment standards. (a) Reciprocating engine powered airplanes. The oxygen apparatus, the minimum rates of oxygen flow, and the supply of oxygen necessary to comply with § 121.327 must meet the standards...) Turbine engine powered airplanes. The oxygen apparatus, the minimum rate of oxygen flow, and the supply of...

14 CFR 121.335 - Equipment standards.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Equipment standards. (a) Reciprocating engine powered airplanes. The oxygen apparatus, the minimum rates of oxygen flow, and the supply of oxygen necessary to comply with § 121.327 must meet the standards...) Turbine engine powered airplanes. The oxygen apparatus, the minimum rate of oxygen flow, and the supply of...

Modeling complex flow structures and drag around a submerged plant of varied posture

NASA Astrophysics Data System (ADS)

Boothroyd, Richard J.; Hardy, Richard J.; Warburton, Jeff; Marjoribanks, Timothy I.

2017-04-01

Although vegetation is present in many rivers, the bulk of past work concerned with modeling the influence of vegetation on flow has considered vegetation to be morphologically simple and has generally neglected the complexity of natural plants. Here we report on a combined flume and numerical model experiment which incorporates time-averaged plant posture, collected through terrestrial laser scanning, into a computational fluid dynamics model to predict flow around a submerged riparian plant. For three depth-limited flow conditions (Reynolds number = 65,000-110,000), plant dynamics were recorded through high-definition video imagery, and the numerical model was validated against flow velocities collected with an acoustic Doppler velocimeter. The plant morphology shows an 18% reduction in plant height and a 14% increase in plant length, compressing and reducing the volumetric canopy morphology as the Reynolds number increases. Plant shear layer turbulence is dominated by Kelvin-Helmholtz type vortices generated through shear instability, the frequency of which is estimated to be between 0.20 and 0.30 Hz, increasing with Reynolds number. These results demonstrate the significant effect that the complex morphology of natural plants has on in-stream drag, and allow a physically determined, species-dependent drag coefficient to be calculated. Given the importance of vegetation in river corridor management, the approach developed here demonstrates the necessity to account for plant motion when calculating vegetative resistance.

Avian community responses to variability in river hydrology.

PubMed

Royan, Alexander; Hannah, David M; Reynolds, S James; Noble, David G; Sadler, Jonathan P

2013-01-01

River flow is a major driver of morphological structure and community dynamics in riverine-floodplain ecosystems. Flow influences in-stream communities through changes in water velocity, depth, temperature, turbidity and nutrient fluxes, and perturbations in the organisation of lower trophic levels are cascaded through the food web, resulting in shifts in food availability for consumer species. River birds are sensitive to spatial and phenological mismatches with aquatic prey following flow disturbances; however, the role of flow as a determinant of riparian ecological structure remains poorly known. This knowledge is crucial to help to predict if, and how, riparian communities will be influenced by climate-induced changes in river flow characterised by more extreme high (i.e. flood) and/or low (i.e. drought) flow events. Here, we combine national-scale datasets of river bird surveys and river flow archives to understand how hydrological disturbance has affected the distribution of riparian species at higher trophic levels. Data were analysed for 71 river locations using a Generalized Additive Model framework and a model averaging procedure. Species had complex but biologically interpretable associations with hydrological indices, with species' responses consistent with their ecology, indicating that hydrological-disturbance has implications for higher trophic levels in riparian food webs. Our quantitative analysis of river flow-bird relationships demonstrates the potential vulnerability of riparian species to the impacts of changing flow variability and represents an important contribution in helping to understand how bird communities might respond to a climate change-induced increase in the intensity of floods and droughts. Moreover, the success in relating parameters of river flow variability to species' distributions highlights the need to include river flow data in climate change impact models of species' distributions.

USING RESPONSES OF OYSTERS IN ESTABLISHING MINIMUM FLOWS AND LEVELS IN THE CALOOSAHATCHEE ESTUARY, FLORIDA

EPA Science Inventory

Volety, Aswani K., S. Gregory Tolley and James T. Winstead. 2002. Using Responses of Oysters in Establishing Minimum Flows and Levels in the Caloosahatchee Estuary, Florida (Abstract). Presented at the 6th International Conference on Shellfish Restoration, 20-24 November 2002, Ch...

40 CFR 1065.546 - Validation of minimum dilution ratio for PM batch sampling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... flows and/or tracer gas concentrations for transient and ramped modal cycles to validate the minimum... mode-average values instead of continuous measurements for discrete mode steady-state duty cycles... molar flow data. This involves determination of at least two of the following three quantities: Raw...

Selected Physical, Chemical, and Biological Data Used to Study Urbanizing Streams in Nine Metropolitan Areas of the United States, 1999-2004

USGS Publications Warehouse

Giddings, Elise M.P.; Bell, Amanda H.; Beaulieu, Karen M.; Cuffney, Thomas F.; Coles, James F.; Brown, Larry R.; Fitzpatrick, Faith A.; Falcone, James A.; Sprague, Lori A.; Bryant, Wade L.; Peppler, Marie C.; Stephens, Cory; McMahon, Gerard

2009-01-01

This report documents and summarizes physical, chemical, and biological data collected during 1999-2004 in a study titled Effects of Urbanization on Stream Ecosystems, undertaken as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Data-collection methods and data processing are described in this report for streamflow; stream temperature; instream chemistry; instream aquatic habitat; and algal, macroinvertebrate, and fish communities. Data summaries prepared for analytical use are presented in downloadable data tables.

Estimated use of water in the United States in 1995

USGS Publications Warehouse

Solley, Wayne B.; Pierce, Robert R.; Perlman, Howard A.

1998-01-01

The purpose of this report is to present consistent and current water-use estimates by state and water-resources region for the United States, Puerto Rico, the U.S. Virgin Islands, and the District of Columbia. Estimates of water withdrawn from surface- and ground-water sources, estimates of consumptive use, and estimates of instream use and wastewater releases during 1995 are presented in this report. This report discusses eight categories of offstream water use--public supply, domestic, commercial, irrigation, livestock, industrial, mining, and thermoelectric power--and one category of instream use: hydroelectric power.

Continuity vs. the Crowd-Tradeoffs Between Continuous and Intermittent Citizen Hydrology Streamflow Observations.

PubMed

Davids, Jeffrey C; van de Giesen, Nick; Rutten, Martine

2017-07-01

Hydrologic data has traditionally been collected with permanent installations of sophisticated and accurate but expensive monitoring equipment at limited numbers of sites. Consequently, observation frequency and costs are high, but spatial coverage of the data is limited. Citizen Hydrology can possibly overcome these challenges by leveraging easily scaled mobile technology and local residents to collect hydrologic data at many sites. However, understanding of how decreased observational frequency impacts the accuracy of key streamflow statistics such as minimum flow, maximum flow, and runoff is limited. To evaluate this impact, we randomly selected 50 active United States Geological Survey streamflow gauges in California. We used 7 years of historical 15-min flow data from 2008 to 2014 to develop minimum flow, maximum flow, and runoff values for each gauge. To mimic lower frequency Citizen Hydrology observations, we developed a bootstrap randomized subsampling with replacement procedure. We calculated the same statistics, and their respective distributions, from 50 subsample iterations with four different subsampling frequencies ranging from daily to monthly. Minimum flows were estimated within 10% for half of the subsample iterations at 39 (daily) and 23 (monthly) of the 50 sites. However, maximum flows were estimated within 10% at only 7 (daily) and 0 (monthly) sites. Runoff volumes were estimated within 10% for half of the iterations at 44 (daily) and 12 (monthly) sites. Watershed flashiness most strongly impacted accuracy of minimum flow, maximum flow, and runoff estimates from subsampled data. Depending on the questions being asked, lower frequency Citizen Hydrology observations can provide useful hydrologic information.

Advancements in dynamic kill calculations for blowout wells

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

Kouba, G.E.; MacDougall, G.R.; Schumacher, B.W.

1993-09-01

This paper addresses the development, interpretation, and use of dynamic kill equations. To this end, three simple calculation techniques are developed for determining the minimum dynamic kill rate. Two techniques contain only single-phase calculations and are independent of reservoir inflow performance. Despite these limitations, these two methods are useful for bracketing the minimum flow rates necessary to kill a blowing well. For the third technique, a simplified mechanistic multiphase-flow model is used to determine a most-probable minimum kill rate.

Tracing Nitrogen Sources in Forested Catchments Under Varying Flow Conditions: Seasonal and Event Scale Patterns

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Kendall, C.

2004-12-01

Our ability to assess how stream nutrient concentrations respond to biogeochemical transformations and stream flow dynamics is often limited by datasets that do not include all flow conditions that occur over event, monthly, seasonal, and yearly time scales. At the Sleepers River Research Watershed in northeastern Vermont, USA, nitrate, DOC (dissolved organic carbon), and major ion concentrations were measured on samples collected over a wide range of flow conditions from summer 2002 through summer 2004. Nutrient flushing occurred at the W-9 catchment and high-frequency sampling revealed critical insights into seasonal and event-scale controls on nutrient concentrations. In this seasonally snow-covered catchment, the earliest stage of snowmelt introduced nitrogen directly to the stream from the snowpack. As snowmelt progressed, the source of stream nitrate shifted to flushing of soil nitrate along shallow subsurface flow paths. In the growing season, nitrogen flushing to streams varied with antecedent moisture conditions. More nitrogen was available to flush to streams when antecedent moisture was lowest, and mobile nitrogen stores in the landscape regenerated under baseflow conditions on times scales as short as 7 days. Leaf fall was another critical time when coupled hydrological and biogeochemical processes controlled nutrient fluxes. With the input of labile organic carbon from freshly decomposing leaves, nitrate concentrations declined sharply in response to in-stream immobilization or denitrification. These high-resolution hydrochemical data from multiple flow regimes are identifying "hot spots" and "hot moments" of biogeochemical and hydrological processes that control nutrient fluxes in streams.

Beyond Rating Curves: Time Series Models for in-Stream Turbidity Prediction

NASA Astrophysics Data System (ADS)

Wang, L.; Mukundan, R.; Zion, M.; Pierson, D. C.

2012-12-01

The New York City Department of Environmental Protection (DEP) manages New York City's water supply, which is comprised of over 20 reservoirs and supplies over 1 billion gallons of water per day to more than 9 million customers. DEP's "West of Hudson" reservoirs located in the Catskill Mountains are unfiltered per a renewable filtration avoidance determination granted by the EPA. While water quality is usually pristine, high volume storm events occasionally cause the reservoirs to become highly turbid. A logical strategy for turbidity control is to temporarily remove the turbid reservoirs from service. While effective in limiting delivery of turbid water and reducing the need for in-reservoir alum flocculation, this strategy runs the risk of negatively impacting water supply reliability. Thus, it is advantageous for DEP to understand how long a particular turbidity event will affect their system. In order to understand the duration, intensity and total load of a turbidity event, predictions of future in-stream turbidity values are important. Traditionally, turbidity predictions have been carried out by applying streamflow observations/forecasts to a flow-turbidity rating curve. However, predictions from rating curves are often inaccurate due to inter- and intra-event variability in flow-turbidity relationships. Predictions can be improved by applying an autoregressive moving average (ARMA) time series model in combination with a traditional rating curve. Since 2003, DEP and the Upstate Freshwater Institute have compiled a relatively consistent set of 15-minute turbidity observations at various locations on Esopus Creek above Ashokan Reservoir. Using daily averages of this data and streamflow observations at nearby USGS gauges, flow-turbidity rating curves were developed via linear regression. Time series analysis revealed that the linear regression residuals may be represented using an ARMA(1,2) process. Based on this information, flow-turbidity regressions with ARMA(1,2) errors were fit to the observations. Preliminary model validation exercises at a 30-day forecast horizon show that the ARMA error models generally improve the predictive skill of the linear regression rating curves. Skill seems to vary based on the ambient hydrologic conditions at the onset of the forecast. For example, ARMA error model forecasts issued before a high flow/turbidity event do not show significant improvements over the rating curve approach. However, ARMA error model forecasts issued during the "falling limb" of the hydrograph are significantly more accurate than rating curves for both single day and accumulated event predictions. In order to assist in reservoir operations decisions associated with turbidity events and general water supply reliability, DEP has initiated design of an Operations Support Tool (OST). OST integrates a reservoir operations model with 2D hydrodynamic water quality models and a database compiling near-real-time data sources and hydrologic forecasts. Currently, OST uses conventional flow-turbidity rating curves and hydrologic forecasts for predictive turbidity inputs. Given the improvements in predictive skill over traditional rating curves, the ARMA error models are currently being evaluated as an addition to DEP's Operations Support Tool.

Instream flow assessment of streams draining the Arbuckle-Simpson Aquifer

USGS Publications Warehouse

Seilheimer, Titus S.; Fisher, William L.

2008-01-01

The availability of high quality water is critical to both humans and ecosystems. A recent proposal was made by rapidly expanding municipalities in central Oklahoma to begin transferring groundwater from the Arbuckle-Simpson aquifer, a sensitive sole-source aquifer in south-central Oklahoma. Concerned citizens and municipalities living on and getting their drinking water from the Arbuckle-Simpson lobbied the legislature to pass a temporary moratorium on groundwater transfer to allow for a comprehensive study of the aquifer and its ecosystems. We conducted an instream flow assessment using Physical Habitat Simulation (PHABSIM) on springs and streams with four spring-dependent species: two minnows, southern redbelly dace (Phoxinus erthyrogaster) and redspot chub (Nocomis asper); and two darters, least darter (Etheostoma microperca) and orangethroat darter (Etheostoma spectabile). Spring habitats are unique compared to other river habitats because they have constant flow and temperature, small and isolated habitat patches, and a general lack of predators. Our study sites included two spring-fed streams, one larger stream with high groundwater inputs, and a river with both groundwater and surface water inputs that is adjacent to the small spring-fed streams. These habitats meet the criteria for groundwater dependent ecosystems because they would not exist without the surface expression of groundwater. A total of 99 transects in all four sites were surveyed for channel elevation, and three sets of water surface elevation and water velocity were measured. Habitat suitability criteria were derived for the species at each site using nonparametric confidence limits based on underwater observations made by snorkelers. Simulations of flow were focused on declines in discharge, which is the expected effect of the proposed groundwater diversion. Our results show that only a small proportion of the total available area in each habitat is considered to be preferred habitat (Weighted Usable Area [WUA]) by the four target species. In the spring habitats, a maximum of 10% of the total area is preferred habitat and that dropped to as little as 3% with decreased flows. The quantity of WUA decreased when lower discharges were simulated for all the target species. Declines in the small amount of habitat that is already available would likely degrade these populations of fishes. In the larger river habitat, the highest WUA occurred at the lowest discharge, which leads us to conclude that in the event of dewatering of the spring habitats, the river should provide some refuge habitat for spring dependent species. Based on the findings of this study, groundwater removal from the aquifer near springs may have adverse impacts on fish habitat availability for spring dependent fish populations if seasonal trends in spring discharge are not maintained (higher in winter and lower in late summer). Quantifying the relationship of streamflow between gaged and ungaged springs in the Arbuckle-Simpson is a possible method to monitor and maintain flows in springs.

Water-quality assessment of the Ozark Plateaus study unit, Arkansas, Kansas, Missouri, and Oklahoma- habitat data and characteristics at selected sites, 1993-95

USGS Publications Warehouse

Femmer, Suzanne R.

1997-01-01

The characterization of instream and riparian habitat is part of the multiple lines of evidence used by the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program to assess the water quality of streams. In the NAWQA Program, integrated physical, chemical, and biological assessments are used to describe water-quality conditions. The instream and riparian habitat data are collected at sites selected for surface-water chemistry analyses and biological assessment. Instream and riparian habitat data are structured in a nested scheme?at sampling reach, segment, and basin scales. The habitat data were collected in the Ozark Plateaus study unit at 41 sites during 1993-95. Thirteen of these sites, representative of selected combinations of physiography, land use, and basin size, have longitudinal, transverse, and quarter point vegetation plot surveys in addition to the Level I survey measurements (reach length, depth, velocity, dominant substrate, embeddedness, and vegetation quarter points, for example) recommended by the NAWQA Program protocols. These habitat data were from onsite measurements, U.S. Geological Survey topographic maps, and a geographic information system. The analyses of the habitat data indicates substantial differences between sites of differing physiography and basin-scale land-use activities. The basins range from 46.4 to 4,318 square kilometers and have stream orders from 2 to 6. All streams studied are a riffle/pool type, and most have cobble that is less than 50 percent embedded as the dominant streambed substrate. Of the three physiographic sections studied, the Boston Mountains have the largest mean segment and sideslope gradients, basin relief, woody species diversity, and stream depths when compared with sites of similar size. Channel sinuosities, mean velocities, and canopy angles are largest at sites in the Springfield Plateau physiographic section. The sites in the Salem Plateau physiographic section have the largest woody vegetation densities and mean channel widths. Sites in basins with predominantly agricultural land use tend to have more open canopies, steeper segment gradients, and more sinuous stream channels than the forested sites. Sites in predominantly forested basins tend to have deeper and swifter flow, smaller channel widths, and more dense woody riparian vegetation (at small basins) than the agricultural sites.

Effects of regulated river flows on habitat suitability for the robust redhorse

USGS Publications Warehouse

Fisk, J. M.; Kwak, Thomas J.; Heise, R. J.

2015-01-01

The Robust Redhorse Moxostoma robustum is a rare and imperiled fish, with wild populations occurring in three drainages from North Carolina to Georgia. Hydroelectric dams have altered the species’ habitat and restricted its range. An augmented minimum-flow regime that will affect Robust Redhorse habitat was recently prescribed for Blewett Falls Dam, a hydroelectric facility on the Pee Dee River, North Carolina. Our objective was to quantify suitable spawning and nonspawning habitat under current and proposed minimum-flow regimes. We implanted radio transmitters into 27 adult Robust Redhorses and relocated the fish from spring 2008 to summer 2009, and we described habitat at 15 spawning capture locations. Nonspawning habitat consisted of deep, slow-moving pools (mean depth D 2.3 m; mean velocity D 0.23 m/s), bedrock and sand substrates, and boulders or coarse woody debris as cover. Spawning habitat was characterized as shallower, faster-moving water (mean depth D 0.84 m; mean velocity D 0.61 m/s) with gravel and cobble as substrates and boulders as cover associated with shoals. Telemetry relocations revealed two behavioral subgroups: a resident subgroup (linear range [mean § SE] D 7.9 § 3.7 river kilometers [rkm]) that remained near spawning areas in the Piedmont region throughout the year; and a migratory subgroup (linear range D 64.3 § 8.4 rkm) that migrated extensively downstream into the Coastal Plain region. Spawning and nonspawning habitat suitability indices were developed based on field microhabitat measurements and were applied to model suitable available habitat (weighted usable area) for current and proposed augmented minimum flows. Suitable habitat (both spawning and nonspawning) increased for each proposed seasonal minimum flow relative to former minimum flows, with substantial increases for spawning sites. Our results contribute to an understanding of how regulated flows affect available habitats for imperiled species. Flow managers can use these findings to regulate discharge more effectively and to create and maintain important habitats during critical periods for priority species.

Reservoir Sedimentation and Upstream Sediment Sources: Perspectives and Future Research Needs on Streambank and Gully Erosion.

PubMed

Fox, G A; Sheshukov, A; Cruse, R; Kolar, R L; Guertault, L; Gesch, K R; Dutnell, R C

2016-05-01

The future reliance on water supply and flood control reservoirs across the globe will continue to expand, especially under a variable climate. As the inventory of new potential dam sites is shrinking, construction of additional reservoirs is less likely compared to simultaneous flow and sediment management in existing reservoirs. One aspect of this sediment management is related to the control of upstream sediment sources. However, key research questions remain regarding upstream sediment loading rates. Highlighted in this article are research needs relative to measuring and predicting sediment transport rates and loading due to streambank and gully erosion within a watershed. For example, additional instream sediment transport and reservoir sedimentation rate measurements are needed across a range of watershed conditions, reservoir sizes, and geographical locations. More research is needed to understand the intricate linkage between upland practices and instream response. A need still exists to clarify the benefit of restoration or stabilization of a small reach within a channel system or maturing gully on total watershed sediment load. We need to better understand the intricate interactions between hydrological and erosion processes to improve prediction, location, and timing of streambank erosion and failure and gully formation. Also, improved process-based measurement and prediction techniques are needed that balance data requirements regarding cohesive soil erodibility and stability as compared to simpler topographic indices for gullies or stream classification systems. Such techniques will allow the research community to address the benefit of various conservation and/or stabilization practices at targeted locations within watersheds.

Reservoir Sedimentation and Upstream Sediment Sources: Perspectives and Future Research Needs on Streambank and Gully Erosion

NASA Astrophysics Data System (ADS)

Fox, G. A.; Sheshukov, A.; Cruse, R.; Kolar, R. L.; Guertault, L.; Gesch, K. R.; Dutnell, R. C.

2016-05-01

The future reliance on water supply and flood control reservoirs across the globe will continue to expand, especially under a variable climate. As the inventory of new potential dam sites is shrinking, construction of additional reservoirs is less likely compared to simultaneous flow and sediment management in existing reservoirs. One aspect of this sediment management is related to the control of upstream sediment sources. However, key research questions remain regarding upstream sediment loading rates. Highlighted in this article are research needs relative to measuring and predicting sediment transport rates and loading due to streambank and gully erosion within a watershed. For example, additional instream sediment transport and reservoir sedimentation rate measurements are needed across a range of watershed conditions, reservoir sizes, and geographical locations. More research is needed to understand the intricate linkage between upland practices and instream response. A need still exists to clarify the benefit of restoration or stabilization of a small reach within a channel system or maturing gully on total watershed sediment load. We need to better understand the intricate interactions between hydrological and erosion processes to improve prediction, location, and timing of streambank erosion and failure and gully formation. Also, improved process-based measurement and prediction techniques are needed that balance data requirements regarding cohesive soil erodibility and stability as compared to simpler topographic indices for gullies or stream classification systems. Such techniques will allow the research community to address the benefit of various conservation and/or stabilization practices at targeted locations within watersheds.

Climate change and watershed mercury export: a multiple projection and model analysis

USGS Publications Warehouse

Golden, Heather E.; Knightes, Christopher D.; Conrads, Paul; Feaster, Toby D.; Davis, Gary M.; Benedict, Stephen T.; Bradley, Paul M.

2013-01-01

Future shifts in climatic conditions may impact watershed mercury (Hg) dynamics and transport. An ensemble of watershed models was applied in the present study to simulate and evaluate the responses of hydrological and total Hg (THg) fluxes from the landscape to the watershed outlet and in-stream THg concentrations to contrasting climate change projections for a watershed in the southeastern coastal plain of the United States. Simulations were conducted under stationary atmospheric deposition and land cover conditions to explicitly evaluate the effect of projected precipitation and temperature on watershed Hg export (i.e., the flux of Hg at the watershed outlet). Based on downscaled inputs from 2 global circulation models that capture extremes of projected wet (Community Climate System Model, Ver 3 [CCSM3]) and dry (ECHAM4/HOPE-G [ECHO]) conditions for this region, watershed model simulation results suggest a decrease of approximately 19% in ensemble-averaged mean annual watershed THg fluxes using the ECHO climate-change model and an increase of approximately 5% in THg fluxes with the CCSM3 model. Ensemble-averaged mean annual ECHO in-stream THg concentrations increased 20%, while those of CCSM3 decreased by 9% between the baseline and projected simulation periods. Watershed model simulation results using both climate change models suggest that monthly watershed THg fluxes increase during the summer, when projected flow is higher than baseline conditions. The present study's multiple watershed model approach underscores the uncertainty associated with climate change response projections and their use in climate change management decisions. Thus, single-model predictions can be misleading, particularly in developmental stages of watershed Hg modeling.

Large wood transport and jam formation in a series of flume experiments

NASA Astrophysics Data System (ADS)

Davidson, S. L.; MacKenzie, L. G.; Eaton, B. C.

2015-12-01

Large wood has historically been removed from streams, resulting in the depletion of in-stream wood in waterways worldwide. As wood increases morphological and hydraulic complexity, the addition of large wood is commonly employed as a means to rehabilitate in-stream habitat. At present, however, the scientific understanding of wood mobilization and transport is incomplete. This paper presents results from a series of four flume experiments in which wood was added to a reach to investigate the piece and reach characteristics that determine wood stability and transport, as well as the time scale required for newly recruited wood to self-organize into stable jams. Our results show that wood transitions from a randomly distributed newly recruited state to a self-organized, or jam-stabilized state, over the course of a single bankfull flow event. Statistical analyses of piece mobility during this transitional period indicate that piece irregularities, especially rootwads, dictate the stability of individual wood pieces; rootwad presence or absence accounts for up to 80% of the variance explained by linear regression models for transport distance. Furthermore, small pieces containing rootwads are especially stable. Large ramped pieces provide nuclei for the formation of persistent wood jams, and the frequency of these pieces in the reach impacts the travel distance of mobile wood. This research shows that the simulation of realistic wood dynamics is possible using a simplified physical model, and also has management implications, as it suggests that randomly added wood may organize into persistent, stable jams, and characterizes the time scale for this transition.

Forest clearfelling effects on dissolved oxygen and metabolism in peatland streams.

PubMed

O'Driscoll, Connie; O'Connor, Mark; Asam, Zaki-Ul-Zaman; de Eyto, Elvira; Brown, Lee E; Xiao, Liwen

2016-01-15

Peatlands cover ∼3% of the world's landmass and large expanses have been altered significantly as a consequence of land use change. Forestry activities are a key pressure on these catchments increasing suspended sediment and nutrient export to receiving waters. The aim of this study was to investigate stream dissolved oxygen (DO) and metabolic activity response following clearfelling of a 39-year-old lodgepole pine and Sitka spruce forestry in an upland peat catchment. Significant effects of clearfelling on water temperature, flows, DO and stream metabolic (photosynthesis, respiration) rates were revealed. Stream temperature and discharge significantly increased in the study stream following clearfelling. Instream ecosystem respiration increased significantly following clearfelling, indicating an increase in the net consumption of organic carbon. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of spray-irrigated municipal wastewater on a small watershed in Chester County, Pennsylvania

USGS Publications Warehouse

Schreffler, Curtis L.; Galeone, Daniel G.

2005-01-01

Spray irrigation is a method for disposing of secondary treated municipal wastewater by spraying it on the land surface (fig. 1). The sprayed wastewater either evaporates into the air, soaks into the soil, or percolates through the soil and recharges the ground water. Land application of wastewater has advantages over conventional means of disposal by direct discharge to streams because the wastewater recharges the ground-water system and increases base flow in streams. Additional benefits are derived from the "natural" treatment of the wastewater that takes place in the soil when plants and other biota remove some nutrients (nitrogen and phosphorus) from the wastewater (Pennsylvania Department of Environmental Protection, 2003). The removal of nutrients is one advantage spray irrigation has to conventional disposal methods like instream discharge.

Habitat Suitability Index Models and Instream Flow Suitability Curves: American shad

USGS Publications Warehouse

Stier, David J.; Crance, Johnie H.

1985-01-01

INTRODUCTION The American shad, an anadromous species, is the largest member of the herring family (Clupeidae) and is native to North America (Talbot and Sykes 1958; Hildebrand 1963; Walburg and Nichols 1967). Historically, the commercial fishery for American shad on the Atlantic coast was widespread and intense; in 1896 the estimated catch was 22.7 million kg (50 million lb). By 1960, however, the estimated catch had dropped to slightly more than 3.6 million kg (8 million lb), according to Walburg and Nichols (1967). Pollution, overfishing, and dams constructed across streams that prevent shad from reaching their spawning grounds have caused partial or total depletion of stocks (Hildebrand 1963). Several programs aimed at restoring American shad to their former range have been initiated by Federal and State agencies.

Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2007-2008

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

Achord, Stephen; Sandford, Benjamin P.; Hockersmith, Eric E.

2009-07-09

This report provides results from an ongoing project to monitor the migration behavior and survival of wild juvenile spring/summer Chinook salmon in the Snake River Basin. Data reported is from detections of PIT tagged fish during late summer 2007 through mid-2008. Fish were tagged in summer 2007 by the National Marine Fisheries Service (NMFS) in Idaho and by the Oregon Department of Fish and Wildlife (ODFW) in Oregon. Our analyses include migration behavior and estimated survival of fish at instream PIT-tag monitors and arrival timing and estimated survival to Lower Granite Dam. Principal results from tagging and interrogation during 2007-2008more » are: (1) In July and August 2007, we PIT tagged and released 7,390 wild Chinook salmon parr in 12 Idaho streams or sample areas. (2) Overall observed mortality from collection, handling, tagging, and after a 24-hour holding period was 1.4%. (3) Of the 2,524 Chinook salmon parr PIT tagged and released in Valley Creek in summer 2007, 218 (8.6%) were detected at two instream PIT-tag monitoring systems in lower Valley Creek from late summer 2007 to the following spring 2008. Of these, 71.6% were detected in late summer/fall, 11.9% in winter, and 16.5% in spring. Estimated parr-to-smolt survival to Lower Granite Dam was 15.5% for the late summer/fall group, 48.0% for the winter group, and 58.5% for the spring group. Based on detections at downstream dams, the overall efficiency of VC1 (upper) or VC2 (lower) Valley Creek monitors for detecting these fish was 21.1%. Using this VC1 or VC2 efficiency, an estimated 40.8% of all summer-tagged parr survived to move out of Valley Creek, and their estimated survival from that point to Lower Granite Dam was 26.5%. Overall estimated parr-to-smolt survival for all summer-tagged parr from this stream at the dam was 12.1%. Development and improvement of instream PIT-tag monitoring systems continued throughout 2007 and 2008. (4) Testing of PIT-tag antennas in lower Big Creek during 2007-2008 showed these antennas (and anchoring method) are not adequate to withstand high spring flows in this drainage. Future plans involve removing these antennas before high spring flows. (5) At Little Goose Dam in 2008, length and/or weight were taken on 505 recaptured fish from 12 Idaho stream populations. Fish had grown an average of 40.1 mm in length and 10.6 g in weight over an average of 288 d. Their mean condition factor declined from 1.25 at release (parr) to 1.05 at recapture (smolt). (6) Mean release lengths for detected fish were significantly larger than for fish not detected the following spring and summer (P < 0.0001). (7) Fish that migrated through Lower Granite Dam in April and May were significantly larger at release than fish that migrated after May (P < 0.0001) (only 12 fish migrated after May). (8) In 2008, peak detections at Lower Granite Dam of parr tagged during summer 2007 (from the 12 stream populations in Idaho and 4 streams in Oregon) occurred during moderate flows of 87.5 kcfs on 7 May and high flows of 197.3 kcfs on 20 May. The 10th, 50th, and 90th percentile passage occurred on 30 April, 11 May, and 23 May, respectively. (9) In 2007-2008, estimated parr-to-smolt survival to Lower Granite Dam for Idaho and Oregon streams (combined) averaged 19.4% (range 6.2-38.4% depending on stream of origin). In Idaho streams the estimated parr-to-smolt survival averaged 21.0%. This survival was the second highest since 1993 for Idaho streams. Relative parr densities were lower in 2007 (2.4 parr/100 m2) than in all previous years since 2000. In 2008, we observed low-to-moderate flows prior to mid-May and relatively cold weather conditions throughout the spring migration season. These conditions moved half of the fish through Lower Granite Dam prior to mid-May; then high flows moved 50 to 90% of the fish through the dam in only 12 days. Clearly, complex interrelationships of several factors drive the annual migrational timing of the stocks.« less

Arsenic loads in Spearfish Creek, western South Dakota, water years 1989-91

USGS Publications Warehouse

Driscoll, Daniel G.; Hayes, Timothy S.

1995-01-01

Numerous small tributaries on the eastern flank of Spearfish Creek originate within a mineralized area with a long history of gold-mining activity. Some streams draining this area are known to have elevated concentrations of arsenic. One such tributary is Annie Creek, where arsenic concentrations regularly approach the Maximum Contaminant Level of 50 mg/L (micrograms per liter) established by the U.S. Environmental Protection Agency. A site on Annie Creek was proposed for inclusion on the National Priorities List by the Environmental Protection Agency in 1991. This report presents information about arsenic loads and concentrations in Spearfish Creek and its tributaries, including Annie Creek. Stream types were classified according to geologic characteris- tics and in-stream arsenic concentrations. The first type includes streams that lack significant arsenic sources and have low in-stream arsenic concentra- tions. The second type has abundant arsenic sources and high in-stream concentrations. The third type has abundant arsenic sources but only moderate in-stream concentrations. The fourth type is a mixture of the first three types. Annual loads of dissolved arsenic were calculated for two reaches of Spearfish Creek to quantify arsenic loads at selected gaging stations during water years 1989-91. Mass-balance calculations also were performed to estimate arsenic concentrations for ungaged inflows to Spearfish Creek. The drainage area of the upstream reach includes significant mineralized areas, whereas the drainage area of the downstream reach generally is without known arsenic sources. The average load of dissolved arsenic transported from the upstream reach of Spearfish Creek, which is representative of a type 4 stream, was 158 kilograms per year, calculated for station 06430900, Spearfish Creek above Spearfish. Gaged headwater tributaries draining unmineralized areas (type 1) contributed only 16 percent of the arsenic load in 63 percent of the discharge. Annie Creek (type 2), which has the highest measured arsenic concentra- tions in the Spearfish Creek drainage, contributed about 15 percent of the arsenic load in about 2 percent of the discharge of the upstream reach. Squaw Creek, which drains another mineralized area, but has only moderate in-stream concentrations (type 3), contributed 4 percent of the arsenic load in 5 percent of the discharge. Ungaged inflows to the reach contributed the remaining 65 percent of the arsenic load in 30 percent of the discharge. The calculated loads from ungaged inflows include all arsenic contributed by surface- and ground-water sources, as well as any additions of arsenic from dissolution of arsenic-bearing solid phases, or from desorption of arsenic from solid surfaces, within the streambed of the upstream reach. Mass-balance calculations indicate that dissolved arsenic concentrations of the ungaged inflows in the upstream reach averaged about 9 mg/L. In-stream arsenic concentrations of ungaged inflows from the unmineralized western flank of Spearfish Creek probably are generally low (type 1). Thus, in-stream arsenic concentrations for ungaged inflows draining the mineralized eastern flank of Spearfish probably average almost twice that level, or about 18 mg/L. Some ungaged, eastern-flank inflows probably are derived from type 3 drainages, with only moderate arsenic concentrations. If so, other ungaged, eastern-flank inflows could have in-stream arsenic concentrations similar to those of Annie Creek. No significant arsenic sources were apparent in the downstream reach of Spearfish Creek. Over the course of the downstream reach, arsenic concentrations decreased somewhat, probably resulting from dilution, as well as from possible chemical adsorption to sediment surfaces or arsenic-phase precipitation. A decrease in arsenic loads resulted from various diversions from the creek and from the potential chemical removal processes. Because of a large margin of error associated with calculation o

Minimum average 7-day, 10-year flows in the Hudson River basin, New York, with release-flow data on Rondout and Ashokan reservoirs

USGS Publications Warehouse

Archer, Roger J.

1978-01-01

Minimum average 7-day, 10-year flow at 67 gaging stations and 173 partial-record stations in the Hudson River basin are given in tabular form. Variation of the 7-day, 10-year low flow from point to point in selected reaches, and the corresponding times of travel, are shown graphically for Wawayanda Creek, Wallkill River, Woodbury-Moodna Creek, and the Fishkill Creek basins. The 7-day, 10-year low flow for the Saw Kill basin, and estimates of the 7-day, 10-year low flow of the Roeliff Jansen Kill at Ancram and of Birch Creek at Pine Hill, are given. Summaries of discharge from Rondout and Ashokan Reservoirs, in Ulster County, are also included. Minimum average 7-day, 10-year flow for gaging stations with 10 years or more of record were determined by log-Pearson Type III computation; those for partial-record stations were developed by correlation of discharge measurements made at the partial-record stations with discharge data from appropriate long-term gaging stations. The variation in low flows from point to point within the selected subbasins were estimated from available data and regional regression formula. Time of travel at these flows in the four subbasins was estimated from available data and Boning's equations.

Effects of meridional flow variations on solar cycles 23 and 24

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

Upton, Lisa; Hathaway, David H., E-mail: lisa.a.upton@vanderbilt.edu, E-mail: lar0009@uah.edu, E-mail: david.hathaway@nasa.gov

2014-09-10

The faster meridional flow that preceded the solar cycle 23/24 minimum is thought to have led to weaker polar field strengths, producing the extended solar minimum and the unusually weak cycle 24. To determine the impact of meridional flow variations on the sunspot cycle, we have simulated the Sun's surface magnetic field evolution with our newly developed surface flux transport model. We investigate three different cases: a constant average meridional flow, the observed time-varying meridional flow, and a time-varying meridional flow in which the observed variations from the average have been doubled. Comparison of these simulations shows that the variationsmore » in the meridional flow over cycle 23 have a significant impact (∼20%) on the polar fields. However, the variations produced polar fields that were stronger than they would have been otherwise. We propose that the primary cause of the extended cycle 23/24 minimum and weak cycle 24 was the weakness of cycle 23 itself—with fewer sunspots, there was insufficient flux to build a big cycle. We also find that any polar counter-cells in the meridional flow (equatorward flow at high latitudes) produce flux concentrations at mid-to-high latitudes that are not consistent with observations.« less

Minimum viewing angle for visually guided ground speed control in bumblebees.

PubMed

Baird, Emily; Kornfeldt, Torill; Dacke, Marie

2010-05-01

To control flight, flying insects extract information from the pattern of visual motion generated during flight, known as optic flow. To regulate their ground speed, insects such as honeybees and Drosophila hold the rate of optic flow in the axial direction (front-to-back) constant. A consequence of this strategy is that its performance varies with the minimum viewing angle (the deviation from the frontal direction of the longitudinal axis of the insect) at which changes in axial optic flow are detected. The greater this angle, the later changes in the rate of optic flow, caused by changes in the density of the environment, will be detected. The aim of the present study is to examine the mechanisms of ground speed control in bumblebees and to identify the extent of the visual range over which optic flow for ground speed control is measured. Bumblebees were trained to fly through an experimental tunnel consisting of parallel vertical walls. Flights were recorded when (1) the distance between the tunnel walls was either 15 or 30 cm, (2) the visual texture on the tunnel walls provided either strong or weak optic flow cues and (3) the distance between the walls changed abruptly halfway along the tunnel's length. The results reveal that bumblebees regulate ground speed using optic flow cues and that changes in the rate of optic flow are detected at a minimum viewing angle of 23-30 deg., with a visual field that extends to approximately 155 deg. By measuring optic flow over a visual field that has a low minimum viewing angle, bumblebees are able to detect and respond to changes in the proximity of the environment well before they are encountered.

The effects of drainage basin geomorphometry on minimum low flow discharge: the study of small watershed in Kelang River Valley in Peninsular Malaysia.

PubMed

Yunus, Ahmad Jailani Muhamed; Nakagoshi, Nobukazu; Salleh, Khairulmaini Osman

2003-03-01

This study investigate the relationships between geomorphometric properties and the minimum low flow discharge of undisturbed drainage basins in the Taman Bukit Cahaya Seri Alam Forest Reserve, Peninsular Malaysia. The drainage basins selected were third-order basins so as to facilitate a common base for sampling and performing an unbiased statistical analyses. Three levels of relationships were observed in the study. Significant relationships existed between the geomorphometric properties as shown by the correlation network analysis; secondly, individual geomorphometric properties were observed to influence minimum flow discharge; and finally, the multiple regression model set up showed that minimum flow discharge (Q min) was dependent of basin area (AU), stream length (LS), maximum relief (Hmax), average relief (HAV) and stream frequency (SF). These findings further enforced other studies of this nature that drainage basins were dynamic and functional entities whose operations were governed by complex interrelationships occurring within the basins. Changes to any of the geomorphometric properties would influence their role as basin regulators thus influencing a change in basin response. In the case of the basin's minimum low flow, a change in any of the properties considered in the regression model influenced the "time to peak" of flow. A shorter time period would mean higher discharge, which is generally considered the prerequisite to flooding. This research also conclude that the role of geomorphometric properties to control the water supply within the stream through out the year even though during the drought and less precipitations months. Drainage basins are sensitive entities and any deteriorations involve will generate reciprocals and response to the water supply as well as the habitat within the areas.

Flow Boiling Critical Heat Flux in Reduced Gravity

NASA Technical Reports Server (NTRS)

Mudawar, Issam; Zhang, Hui; Hasan, Mohammad M.

2004-01-01

This study provides systematic method for reducing power consumption in reduced gravity systems by adopting minimum velocity required to provide adequate CHF and preclude detrimental effects of reduced gravity . This study proves it is possible to use existing 1 ge flow boiling and CHF correlations and models to design reduced gravity systems provided minimum velocity criteria are met

Simulated Effects of Seasonal Ground-Water Pumpage for Irrigation on Hydrologic Conditions in the Lower Apalachicola-Chattahoochee-Flint River Basin, Southwestern Georgia and Parts of Alabama and Florida, 1999-2002

USGS Publications Warehouse

Jones, L. Elliott; Torak, Lynn J.

2006-01-01

To determine the effects of seasonal ground-water pumpage for irrigation, a finite-element ground-water flow model was developed for the Upper Floridan aquifer in the lower Flint River Basin area, including adjacent parts of the Chattahoochee and Apalachicola River Basins. The model simulates withdrawal from the aquifer at 3,280 irrigation, municipal, and industrial wells; stream-aquifer flow between the aquifer and 36 area streams; leakage to and from the overlying upper semiconfining unit; regional ground-water flow at the lateral boundaries of the model; and water-table recharge in areas where the aquifer is at or near land surface. Steady-state calibration to drought conditions of October 1999 indicated that the model could adequately simulate measured groundwater levels at 275 well locations and streamflow gains and losses along 53 reaches of area streams. A transient simulation having 12 monthly stress periods from March 2001 to February 2002 incorporated time-varying stress from irrigation pumpage, stream and lake stage, head in the overlying upper semiconfining unit, and infiltration rates. Analysis of simulated water budgets of the Upper Floridan aquifer provides estimates of the source of water pumped for irrigation. During October 1999, an estimated 127 million gallons per day (Mgal/d) of irrigation pumpage from the Upper Floridan aquifer in the model area were simulated to be derived from changes in: stream-aquifer flux (about 56 Mgal/d, or 44 percent); leakage to or from the upper semiconfining unit (about 49 Mgal/d, or 39 percent); regional flow (about 18 Mgal/d, or 14 percent); leakage to or from Lakes Seminole and Blackshear (about 2.7 Mgal/d, or 2 percent); and flux at the Upper Floridan aquifer updip boundary (about 1.8 Mgal/d, or 1 percent). During the 2001 growing season (May-August), estimated irrigation pumpage ranged from about 310 to 830 Mgal/ d, about 79 percent of the 12-month total. During the growing season, irrigation pumpage was derived from decreased discharge or increased recharge of stream-aquifer flux (from about 23 to 39 percent), leakage to or from the upper semiconfining unit (from about 30 to 36 percent), regional flow (from about 8 to 11 percent), Lakes Seminole and Blackshear (about 2 percent), and flux at the Upper Floridan aquifer updip boundary (about 1 percent). Storage effects (decreased storage gain or increased storage loss) contributed from about 11 to 36 percent of irrigation pumpage during the growing season. Water managers can use the model to determine where and how much additional ground-water pumpage for irrigation should be permitted based on a variety of hydrologic constraints. For example, the model results may indicate that in some critical locations, additional ground-water pumpage during a prolonged drought might reduce stream-aquifer flux enough to cause noncompliance of established minimum instream flow conditions.

Glottal volume velocity waveform characteristics in subjects with and without vocal training, related to gender, sound intensity, fundamental frequency, and age.

PubMed

Sulter, A M; Wit, H P

1996-11-01

Glottal volume velocity waveform characteristics of 224 subjects, categorized in four groups according to gender and vocal training, were determined, and their relations to sound-pressure level, fundamental frequency, intra-oral pressure, and age were analyzed. Subjects phonated at three intensity conditions. The glottal volume velocity waveforms were obtained by inverse filtering the oral flow. Glottal volume velocity waveforms were parameterized with flow-based (minimum flow, ac flow, average flow, maximum flow declination rate) and time-based parameters (closed quotient, closing quotient, speed quotient), as well as with derived parameters (vocal efficiency and glottal resistance). Higher sound-pressure levels, intra-oral pressures, and flow-parameter values (ac flow, maximum flow declination rate) were observed, when compared with previous investigations. These higher values might be the result of the specific phonation tasks (stressed /ae/ vowel in a word and a sentence) or filtering processes. Few statistically significant (p < 0.01) differences in parameters were found between untrained and trained subjects [the maximum flow declination rate and the closing quotient were higher in trained women (p < 0.001), and the speed quotient was higher in trained men (p < 0.005)]. Several statistically significant parameter differences were found between men and women [minimum flow, ac flow, average flow, maximum flow declination rate, closing quotient, glottal resistance (p < 0.001), and closed quotient (p < 0.005)]. Significant effects of intensity condition were observed on ac flow, maximum flow declination rate, closing quotient, and vocal efficiency in women (p < 0.005), and on minimum flow, ac flow, average flow, maximum flow declination rate, closed quotient, and vocal efficiency in men (p < 0.01).

Calculating e-flow using UAV and ground monitoring

NASA Astrophysics Data System (ADS)

Zhao, C. S.; Zhang, C. B.; Yang, S. T.; Liu, C. M.; Xiang, H.; Sun, Y.; Yang, Z. Y.; Zhang, Y.; Yu, X. Y.; Shao, N. F.; Yu, Q.

2017-09-01

Intense human activity has led to serious degradation of basin water ecosystems and severe reduction in the river flow available for aquatic biota. As an important water ecosystem index, environmental flows (e-flows) are crucial for maintaining sustainability. However, most e-flow measurement methods involve long cycles, low efficiency, and transdisciplinary expertise. This makes it impossible to rapidly assess river e-flows at basin or larger scales. This study presents a new method to rapidly assessing e-flows coupling UAV and ground monitorings. UAV was firstly used to calculate river-course cross-sections with high-resolution stereoscopic images. A dominance index was then used to identify key fish species. Afterwards a habitat suitability index, along with biodiversity and integrity indices, was used to determine an appropriate flow velocity with full consideration of the fish spawning period. The cross-sections and flow velocity values were then combined into AEHRA, an e-flow assessment method for studying e-flows and supplying-rate. To verify the results from this new method, the widely used Tennant method was employed. The root-mean-square errors of river cross-sections determined by UAV are less than 0.25 m, which constitutes 3-5% water-depth of the river cross-sections. In the study area of Jinan city, the ecological flow velocity (VE) is equal to or greater than 0.11 m/s, and the ecological water depth (HE) is greater than 0.8 m. The river ecosystem is healthy with the minimum e-flow requirements being always met when it is close to large rivers, which is beneficial for the sustainable development of the water ecosystem. In the south river channel of Jinan, the upstream flow mostly meets the minimum e-flow requirements, and the downstream flow always meets the minimum e-flow requirements. The north of Jinan consists predominantly of artificial river channels used for irrigation. Rainfall rarely meets the minimum e-flow and irrigation water requirements. We suggest that the water shortage problem can be partly solved by diversion of the Yellow River. These results can provide useful information for ecological operations and restoration. The method used in this study for calculating e-flow based on a combination of UAV and ground monitoring can effectively promote research progress into basin e-flow, and provide an important reference for e-flow monitoring around the world.

Floodplain restoration enhances denitrification and reach-scale nitrogen removal in an agricultural stream.

PubMed

Roley, Sarah S; Tank, Jennifer L; Stephen, Mia L; Johnson, Laura T; Beaulieu, Jake J; Witter, Jonathan D

2012-01-01

Streams of the agricultural Midwest, USA, export large quantities of nitrogen, which impairs downstream water quality, most notably in the Gulf of Mexico. The two-stage ditch is a novel restoration practice, in which floodplains are constructed alongside channelized ditches. During high flows, water flows across the floodplains, increasing benthic surface area and stream water residence time, as well as the potential for nitrogen removal via denitrification. To determine two-stage ditch nitrogen removal efficacy, we measured denitrification rates in the channel and on the floodplains of a two-stage ditch in north-central Indiana for one year before and two years after restoration. We found that instream rates were similar before and after the restoration, and they were influenced by surface water NO3- concentration and sediment organic matter content. Denitrification rates were lower on the constructed floodplains and were predicted by soil exchangeable NO3- concentration. Using storm flow simulations, we found that two-stage ditch restoration contributed significantly to NO3- removal during storm events, but because of the high NO3- loads at our study site, < 10% of the NO3- load was removed under all storm flow scenarios. The highest percentage of NO3- removal occurred at the lowest loads; therefore, the two-stage ditch's effectiveness at reducing downstream N loading will be maximized when the practice is coupled with efforts to reduce N inputs from adjacent fields.

Development of a spatially-distributed hydroecological model to simulate cottonwood seedling recruitment along rivers.

PubMed

Benjankar, Rohan; Burke, Michael; Yager, Elowyn; Tonina, Daniele; Egger, Gregory; Rood, Stewart B; Merz, Norm

2014-12-01

Dam operations have altered flood and flow patterns and prevented successful cottonwood seedling recruitment along many rivers. To guide reservoir flow releases to meet cottonwood recruitment needs, we developed a spatially-distributed, GIS-based model that analyzes the hydrophysical requirements for cottonwood recruitment. These requirements are indicated by five physical parameters: (1) annual peak flow timing relative to the interval of seed dispersal, (2) shear stress, which characterizes disturbance, (3) local stage recession after seedling recruitment, (4) recruitment elevation above base flow stage, and (5) duration of winter flooding, which may contribute to seedling mortality. The model categorizes the potential for cottonwood recruitment in four classes and attributes a suitability value at each individual spatial location. The model accuracy was estimated with an error matrix analysis by comparing simulated and field-observed recruitment success. The overall accuracies of this Spatially-Distributed Cottonwood Recruitment model were 47% for a braided reach and 68% for a meander reach along the Kootenai River in Idaho, USA. Model accuracies increased to 64% and 72%, respectively, when fewer favorability classes were considered. The model predicted areas of similarly favorable recruitment potential for 1997 and 2006, two recent years with successful cottonwood recruitment. This model should provide a useful tool to quantify impacts of human activities and climatic variability on cottonwood recruitment, and to prescribe instream flow regimes for the conservation and restoration of riparian woodlands. Copyright © 2014 Elsevier Ltd. All rights reserved.

Urban Stormwater Runoff: A New Class of Environmental Flow Problem

PubMed Central

Walsh, Christopher J.; Fletcher, Tim D.; Burns, Matthew J.

2012-01-01

Environmental flow assessment frameworks have begun to consider changes to flow regimes resulting from land-use change. Urban stormwater runoff, which degrades streams through altered volume, pattern and quality of flow, presents a problem that challenges dominant approaches to stormwater and water resource management, and to environmental flow assessment. We used evidence of ecological response to different stormwater drainage systems to develop methods for input to environmental flow assessment. We identified the nature of hydrologic change resulting from conventional urban stormwater runoff, and the mechanisms by which such hydrologic change is prevented in streams where ecological condition has been protected. We also quantified the increase in total volume resulting from urban stormwater runoff, by comparing annual streamflow volumes from undeveloped catchments with the volumes that would run off impervious surfaces under the same rainfall regimes. In catchments with as little as 5–10% total imperviousness, conventional stormwater drainage, associated with poor in-stream ecological condition, reduces contributions to baseflows and increases the frequency and magnitude of storm flows, but in similarly impervious catchments in which streams retain good ecological condition, informal drainage to forested hillslopes, without a direct piped discharge to the stream, results in little such hydrologic change. In urbanized catchments, dispersed urban stormwater retention measures can potentially protect urban stream ecosystems by mimicking the hydrologic effects of informal drainage, if sufficient water is harvested and kept out of the stream, and if discharged water is treated to a suitable quality. Urban stormwater is a new class of environmental flow problem: one that requires reduction of a large excess volume of water to maintain riverine ecological integrity. It is the best type of problem, because solving it provides an opportunity to solve other problems such as the provision of water for human use. PMID:23029257

A Bayesian changepoint-threshold model to examine the effect of TMDL implementation on the flow-nitrogen concentration relationship in the Neuse River basin.

PubMed

Alameddine, Ibrahim; Qian, Song S; Reckhow, Kenneth H

2011-01-01

In-stream nutrient concentrations are well known to exhibit a strong relationship with river flow. The use of flow measurements to predict nutrient concentrations and subsequently nutrient loads is common in water quality modeling. Nevertheless, most adopted models assume that the relationship between flow and concentration is fixed across time as well as across different flow regimes. In this study, we developed a Bayesian changepoint-threshold model that relaxes these constraints and allows for the identification and quantification of any changes in the underlying flow-concentration relationship across time. The results from our study support the occurrence of a changepoint in time around the year 1999, which coincided with the period of implementing nitrogen control measures as part of the TMDL program developed for the Neuse Estuary in North Carolina. The occurrence of the changepoint challenges the underlying assumption of temporal invariance in the flow-concentrations relationship. The model results also point towards a transition in the river nitrogen delivery system from a point source dominated loading system towards a more complicated nonlinear system, where non-point source nutrient delivery plays a major role. Moreover, we use the developed model to assess the effectiveness of the nitrogen reduction measures in achieving a 30% drop in loading. The results indicate that while there is a strong evidence of a load reduction, there still remains a high level of uncertainty associated with the mean nitrogen load reduction. We show that the level of uncertainty around the estimated load reduction is not random but is flow related. Copyright © 2010 Elsevier Ltd. All rights reserved.

The role of the geophysical template and environmental regimes in controlling stream-living trout populations

USGS Publications Warehouse

Penaluna, Brooke E.; Railsback, Steve F.; Dunham, Jason B.; Johnson, S.; Bilby, Richard E.; Skaugset, Arne E.

2015-01-01

The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus environmental regimes on biomass of trout (Oncorhynchus clarkii clarkii). We parameterized the model with observed data from each of the four headwater streams (their local geophysical template and environmental regime) and then ran 12 simulations where we replaced environmental regimes (stream temperature, flow, turbidity) of a given stream with values from each neighboring stream while keeping the geophysical template fixed. We also performed single-parameter sensitivity analyses on the model results from each of the four streams. Although our modeled findings show that trout biomass is most responsive to changes in the geophysical template of streams, they also reveal that biomass is restricted by available habitat during seasonal low flow, which is a product of both the stream’s geophysical template and flow regime. Our modeled results suggest that differences in the geophysical template among streams render trout more or less sensitive to environmental change, emphasizing the importance of local fish–habitat relationships in streams.

Simulating land-use changes and stormwater-detention basins and evaluating their effect on peak streamflows and stream-water quality in Irondequoit Creek basin, New York—A user's manual for HSPF and GenScn

USGS Publications Warehouse

Coon, William F.

2003-01-01

A computer model of hydrologic and water-quality processes of the Irondequoit Creek basin in Monroe and Ontario Counties, N.Y., was developed during 2000-02 to enable water-resources managers to simulate the effects of future development and stormwater-detention basins on peak flows and water quality of Irondequoit Creek and its tributaries. The model was developed with the program Hydrological Simulation Program-Fortran (HSPF) such that proposed or hypothetical land-use changes and instream stormwater-detention basins could be simulated, and their effects on peak flows and loads of total suspended solids, total phosphorus, ammonia-plus-organic nitrogen, and nitrate-plus-nitrite nitrogen could be analyzed, through an interactive computer program known as Generation and Analysis of Model Simulation Scenarios for Watersheds (GenScn). This report is a user's manual written to guide the Irondequoit Creek Watershed Collaborative in (1) the creation of land-use and flow-detention scenarios for simulation by the HSPF model, and (2) the use of GenScn to analyze the results of these simulations. These analyses can, in turn, aid the group in making basin-wide water-resources-management decisions.

Diminished Stream Nitrate Concentrations Linked to Dissolved Organic Carbon Dynamics After Leaf Fall

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Doctor, D. H.; Kendall, C.

2004-05-01

Thermodynamic coupling of the nitrogen and carbon cycles has broad implications for controls on catchment nutrient fluxes. In the northeast US, leaf fall occurs in early October and the availability of organic carbon increases as the leaves decompose. At the Sleepers River Research Watershed in northeastern Vermont (USA), we sampled stream chemistry from seven nested catchments to determine how stream dissolved organic carbon (DOC) and nitrate vary as a function of flow conditions, land-use, and basin size in response to leaf fall. Following leaf fall, nitrate concentration patterns were quantitatively different from other times of the year. Under baseflow conditions, stream and soil water DOC concentrations were higher than normal, whereas nitrate concentrations declined sharply at the five smallest catchments and more modestly at the two largest catchments. Under high flow conditions, flushing of nitrate was observed, as is typical for stormflow response at Sleepers River. Our field data suggest that in-stream processing of nitrate is likely thermodynamically and kinetically favorable under baseflow but not at higher flow conditions when expanding variable source areas make hydrological connections between nitrate source areas and streams. We are working to evaluate this hypothesis with isotopic and other monitoring data, and to model the coupled interactions of water, DOC, and nitrate fluxes in these nested catchments.

Distribution of spawning activity by anadromous fishes in an atlantic slope drainage after removal of a low-head dam

USGS Publications Warehouse

Burdick, S.M.; Hightower, J.E.

2006-01-01

In 1998, the Quaker Neck Dam was removed from the Neuse River near Goldsboro, North Carolina, restoring access to more than 120 km of potential main-stem spawning habitat and 1,488 km of potential tributary spawning habitat to anadromous fishes. We used plankton sampling and standardized electrofishing to examine the extent to which anadromous fishes utilized this restored spawning habitat in 2003 and 2004. Evidence of spawning activity was detected upstream of the former dam site for three anadromous species: American shad Alosa sapidissima, hickory shad A. mediocris, and striped bass Morone saxatilis. The percentages of eggs and larvae collected in the restored upstream habitat were greater in 2003, when spring flows were high, than in 2004. River reaches where spawning occurred were estimated from egg stage and water velocity data. Spawning of American shad and striped bass occurred primarily in main-stem river reaches that were further upstream during the year of higher spring flows. Hickory shad generally spawned in downstream reaches and in tributaries above and below the former dam site. These results demonstrate that anadromous fishes will take advantage of upper basin spawning habitat restored through dam removal as long as instream flows are adequate to facilitate upstream migration.

Analyzing Quadratic Unconstrained Binary Optimization Problems Via Multicommodity Flows

PubMed Central

Wang, Di; Kleinberg, Robert D.

2009-01-01

Quadratic Unconstrained Binary Optimization (QUBO) problems concern the minimization of quadratic polynomials in n {0, 1}-valued variables. These problems are NP-complete, but prior work has identified a sequence of polynomial-time computable lower bounds on the minimum value, denoted by C2, C3, C4,…. It is known that C2 can be computed by solving a maximum-flow problem, whereas the only previously known algorithms for computing Ck (k > 2) require solving a linear program. In this paper we prove that C3 can be computed by solving a maximum multicommodity flow problem in a graph constructed from the quadratic function. In addition to providing a lower bound on the minimum value of the quadratic function on {0, 1}n, this multicommodity flow problem also provides some information about the coordinates of the point where this minimum is achieved. By looking at the edges that are never saturated in any maximum multicommodity flow, we can identify relational persistencies: pairs of variables that must have the same or different values in any minimizing assignment. We furthermore show that all of these persistencies can be detected by solving single-commodity flow problems in the same network. PMID:20161596

Analyzing Quadratic Unconstrained Binary Optimization Problems Via Multicommodity Flows.

PubMed

Wang, Di; Kleinberg, Robert D

2009-11-28

Quadratic Unconstrained Binary Optimization (QUBO) problems concern the minimization of quadratic polynomials in n {0, 1}-valued variables. These problems are NP-complete, but prior work has identified a sequence of polynomial-time computable lower bounds on the minimum value, denoted by C(2), C(3), C(4),…. It is known that C(2) can be computed by solving a maximum-flow problem, whereas the only previously known algorithms for computing C(k) (k > 2) require solving a linear program. In this paper we prove that C(3) can be computed by solving a maximum multicommodity flow problem in a graph constructed from the quadratic function. In addition to providing a lower bound on the minimum value of the quadratic function on {0, 1}(n), this multicommodity flow problem also provides some information about the coordinates of the point where this minimum is achieved. By looking at the edges that are never saturated in any maximum multicommodity flow, we can identify relational persistencies: pairs of variables that must have the same or different values in any minimizing assignment. We furthermore show that all of these persistencies can be detected by solving single-commodity flow problems in the same network.

Relation between flows and dissolved oxygen in the Roanoke River between Roanoke Rapids Dam and Jamesville, North Carolina, 2005-2009

USGS Publications Warehouse

Wehmeyer, Loren L.; Wagner, Chad R.

2011-01-01

The relation between dam releases and dissolved-oxygen concentration, saturation and deficit, downstream from Roanoke Rapids Dam in North Carolina was evaluated from 2005 to 2009. Dissolved-oxygen data collected at four water-quality monitoring stations downstream from Roanoke Rapids Dam were used to determine if any statistical relations or discernible quantitative or qualitative patterns linked Roanoke River in-stream dissolved-oxygen levels to hydropower peaking at Roanoke Rapids Dam. Unregulated tributaries that inundate and drain portions of the Roanoke River flood plain are crucial in relation to in-stream dissolved oxygen. Hydropower peaking from 2005 to 2009 both inundated and drained portions of the flood plain independently of large storms. The effects of these changes in flow on dissolved-oxygen dynamics are difficult to isolate, however, because of (1) the variable travel time for water to move down the 112-mile reach of the Roanoke River from Roanoke Rapids Dam to Jamesville, North Carolina, and (2) the range of in-situ conditions, particularly inundation history and water temperature, in the flood plain. Statistical testing was conducted on the travel-time-adjusted hourly data measured at each of the four water-quality stations between May and November 2005-2009 when the weekly mean flow was 5,000-12,000 cubic feet per second (a range when Roanoke Rapids Dam operations likely affect tributary and flood-plain water levels). Results of this statistical testing indicate that at the 99-percent confidence interval dissolved-oxygen levels downstream from Roanoke Rapids Dam were lower during peaking weeks than during non-peaking weeks in three of the five years and higher in one of the five years; no data were available for weeks with peaking in 2007. For the four years of statistically significant differences in dissolved oxygen between peaking and non-peaking weeks, three of the years had statistically signficant differences in water temperature. Years with higher water temperature during peaking had lower dissolved oxygen during peaking. Only 2009 had no constistent statistically significant water-temperature difference at all sites, and dissolved-oxygen levels downstream from Roanoke Rapids Dam during peaking weeks that year were lower than during non-peaking weeks. Between 2005 and 2009, daily mean dissolved-oxygen concentrations below the State standard occurred during only 1 of the 17 (6 percent) peaking weeks, with no occurrence of instantaneous dissolved-oxygen concentrations below the State standard. This occurrence was during a 9-day period in July 2005 when the daily maximum air temperatures approached or exceeded 100 degrees Fahrenheit, and the draining of the flood plains from peaking operations was followed by consecutive days of low flows.

Estimated Water Use in Puerto Rico, 2005

USGS Publications Warehouse

Molina-Rivera, Wanda L.; Gómez-Gómez, Fernando

2008-01-01

Water-use data were compiled for the 78 municipios of the Commonwealth of Puerto Rico for 2005. Five offstream categories were considered: public-supply water withdrawals and deliveries, domestic self-supplied water use, industrial self-supplied ground-water withdrawals, crop irrigation water use, and thermoelectric power freshwater use. One water-use category also was considered: power-generation instream water use (thermoelectric-saline withdrawals and hydroelectric power). Freshwater withdrawals and deliveries for offstream use from surface- and ground-water sources in Puerto Rico were estimated at 712 million gallons per day (Mgal/d). The largest amount of freshwater withdrawn was by public-supply water facilities and was estimated at 652 Mgal/d. The public-supply domestic water use was estimated at 347 Mgal/d. Fresh surface- and ground-water withdrawals by domestic self-supplied users were estimated at 2.1 Mgal/d and the industrial self-supplied withdrawals were estimated at 9.4 Mgal/d. Withdrawals for crop irrigation purposes were estimated at 45.2 Mgal/d, or approximately 6.3 percent of all offstream freshwater withdrawals. Instream freshwater withdrawals by hydroelectric facilities were estimated at 568 Mgal/d and saline instream surface-water withdrawals for cooling purposes by thermoelectric-power facilities was estimated at 2,288 Mgal/d.

Understanding the Role of the Co-Play between Land Use and Climate on Sediment Flux Laws in Intensively Managed Landscapes

NASA Astrophysics Data System (ADS)

Abban, B. K.; Papanicolaou, T.; Wilson, C. G.; Giannopoulos, C.; Sivapalan, M.

2017-12-01

In intensively managed landscapes (IMLs), changes in the land cover from what were previously grasslands, and their associated management practices, have led to a high degree of spatial heterogeneity and temporal variability in landscape processes that were absent pre-settlement. This has fundamentally altered terrestrial and instream sediment flux characteristics in regards to net amounts and proportions of source contributions, at shorter time scales. Sediment flux laws are now highly impacted by event-based dynamics. Whereas some events result in highly intermittent fluxes, others result in fluxes that largely propagate in the form of waves. This behavior is governed by the extent of land cover at the given time of the season, as well as the magnitude of the storm event. In addition, flux behavior changes as one moves from the plot scale to the watershed scale, and also with crop rotation. Thus, fluxes are now non-stationary due to continued human activity and its co-play with climate. The goal of this study is to develop a better understanding of the non-stationarity in sediment flux laws that arise from the co-play between land use and climate. Our approach involves the development of a modeling framework that considers all the exchanges between terrestrial and instream sources and addresses the issue of equifinality regarding terrestrial and instream source contributions on net sediment fluxes. The modeling framework couples an established terrestrial erosion model with an established in-stream sediment transport model. As a first step, our study focuses on the Clear Creek Watershed, IA, which is part of the Critical Zone Observatory for Intensively Managed Landscapes. We complement our modeling efforts with extensive terrestrial and instream field observations gathered at different times of the growing season, and in different years. We also used Bayesian sediment sourcing techniques to determine the provenance of transported material as well as the uncertainty related to the travel times and delivery of material across the different spatial scales. Findings from this study will shed light on the dominant factors governing fluxes laws and how they change over the course of a season, as well as the factors that control the changes in the flux laws across space.

Estimated use of water in the Delaware River Basin in Delaware, New Jersey, New York, and Pennsylvania, 2010

USGS Publications Warehouse

Hutson, Susan S.; Linsey, Kristin S.; Ludlow, Russell A.; Reyes, Betzaida; Shourds, Jennifer L.

2016-11-07

The Delaware River Basin (DRB) was selected as a Focus Area Study in 2011 by the U.S. Geological Survey (USGS) as part of the USGS National Water Census. The National Water Census is a USGS research program that focuses on national water availability and use and then develops new water accounting tools and assesses water availability at both the regional and national scales. One of the water management needs that the DRB study addressed, and that was identified by stakeholder groups from the DRB, was to improve the integration of state water use and water-supply data and to provide the compiled water use information to basin users. This water use information was also used in the hydrologic modeling and ecological components of the study.Instream and offstream water use was calculated for 2010 for the DRB based on information received from Delaware, New Jersey, New York, and Pennsylvania. Water withdrawal, interbasin transfers, return flow, and hydroelectric power generation release data were compiled for 11 categories by hydrologic subregion, basin, subbasin, and subwatershed. Data availability varied by state. Site-specific data were used whenever possible to calculate public supply, irrigation (golf courses, nurseries, sod farms, and crops), aquaculture, self-supplied industrial, commercial, mining, thermoelectric, and hydroelectric power withdrawals. Where site-specific data were not available, primarily for crop irrigation, livestock, and domestic use, various techniques were used to estimate water withdrawals.Total water withdrawals in the Delaware River Basin were calculated to be about 7,130 million gallons per day (Mgal/d) in 2010. Calculations of withdrawals by source indicate that freshwater withdrawals were about 4,130 Mgal/d (58 percent of the total) and the remaining 3,000 Mgal/d (42 percent) were from saline water. Total surface-water withdrawals were calculated to be 6,590 Mgal/d, or 92 percent of the total; about 54 percent (3,590 Mgal/d) of surface water withdrawn was freshwater. Total groundwater withdrawals were calculated to be 545 Mgal/d (8 percent of the total), all of which was freshwater. During 2010, calculated withdrawals by category, in decreasing order, were: thermoelectric power, 4,910 Mgal/d; public supply, 1,490 Mgal/d; self-supplied industrial, 350 Mgal/d; irrigation, 175 Mgal/d; self-supplied domestic, 117 Mgal/d; mining, 41.3 Mgal/d; aquaculture, 19.3 Mgal/d; livestock, 6.72 Mgal/d, and commercial, 5.89 Mgal/d. The amount of instream use for hydroelectric power generation purposes in 2010 was reported to be 273 Mgal/d for the Wallenpaupack Plant and 127 Mgal/d for the Mongaup River system.Total return flows in the DRB were 2,960 Mgal/d in 2010. Although municipal wastewater-treatment plants accounted for 539 (97 percent) of the return-flow sites, they accounted for about 70 percent of the total return flows in the DRB. There was limited information on return flows from thermoelectric power.

Habitat Suitability Index Models and Instream Flow Suitability Curves: Paddlefish

USGS Publications Warehouse

Hubert, Wayne A.; Anderson, Stanley H.; Southall, Peter D.; Crance, Johnie H.

1984-01-01

The original range of the paddlefish was the Mississippi River drainage and adjacent Gul f Coast dra i nage. It was once found in some of the Great Lakes (Carlson and Bonislawsky 1981). The paddlefish is generally an inhabitant of large rivers, but it occurs in reservoirs and natural lakes connected to large rivers. Much of the original range has been reduced due to habitat alterations: (1) destruction of spawning areas; (2) blockage of movements by dams; (3) channelization and elimination of backwater areas; (4) dewatering of streams; and (5) pollution (Carlson and Bonislawsky 1981). Several States officially consider the paddlefish as rare or endangered (Miller 1972). An indexed bibliography of all known paddlefish work was prepared by Graham and Bonislawsky (1978) and recently updated to include more than 480 citations (Graham and Bonislawsky, in press).

Season-ahead Drought Forecast Models for the Lower Colorado River Authority in Texas

NASA Astrophysics Data System (ADS)

Block, P. J.; Zimmerman, B.; Grzegorzewski, M.; Watkins, D. W., Jr.; Anderson, R.

2014-12-01

The Lower Colorado River Authority (LCRA) in Austin, Texas, manages the Highland Lakes reservoir system in Central Texas, a series of six lakes on the Lower Colorado River. This system provides water to approximately 1.1 million people in Central Texas, supplies hydropower to a 55-county area, supports rice farming along the Texas Gulf Coast, and sustains in-stream flows in the Lower Colorado River and freshwater inflows to Matagorda Bay. The current, prolonged drought conditions are severely taxing the LCRA's system, making allocation and management decisions exceptionally challenging, and affecting the ability of constituents to conduct proper planning. In this work, we further develop and evaluate season-ahead statistical streamflow and precipitation forecast models for integration into LCRA decision support models. Optimal forecast lead time, predictive skill, form, and communication are all considered.

Solar-cycle Variations of Meridional Flows in the Solar Convection Zone Using Helioseismic Methods

NASA Astrophysics Data System (ADS)

Lin, Chia-Hsien; Chou, Dean-Yi

2018-06-01

The solar meridional flow is an axisymmetric flow in solar meridional planes, extending through the convection zone. Here we study its solar-cycle variations in the convection zone using SOHO/MDI helioseismic data from 1996 to 2010, including two solar minima and one maximum. The travel-time difference between northward and southward acoustic waves is related to the meridional flow along the wave path. Applying the ray approximation and the SOLA inversion method to the travel-time difference measured in a previous study, we obtain the meridional flow distributions in 0.67 ≤ r ≤ 0.96R ⊙ at the minimum and maximum. At the minimum, the flow has a three-layer structure: poleward in the upper convection zone, equatorward in the middle convection zone, and poleward again in the lower convection zone. The flow speed is close to zero within the error bar near the base of the convection zone. The flow distribution changes significantly from the minimum to the maximum. The change above 0.9R ⊙ shows two phenomena: first, the poleward flow speed is reduced at the maximum; second, an additional convergent flow centered at the active latitudes is generated at the maximum. These two phenomena are consistent with the surface meridional flow reported in previous studies. The change in flow extends all the way down to the base of the convection zone, and the pattern of the change below 0.9R ⊙ is more complicated. However, it is clear that the active latitudes play a role in the flow change: the changes in flow speed below and above the active latitudes have opposite signs. This suggests that magnetic fields could be responsible for the flow change.

A pre-dam-removal assessment of sediment transport for four dams on the Kalamazoo River between Plainwell and Allegan, Michigan

USGS Publications Warehouse

Syed, Atiq U.; Bennett, James P.; Rachol, Cynthia M.

2005-01-01

Four dams on the Kalamazoo River between the cities of Plainwell and Allegan, Mich., are in varying states of disrepair. The Michigan Department of Environmental Quality (MDEQ) and U.S. Environmental Protection Agency (USEPA) are considering removing these dams to restore the river channels to pre-dam conditions. This study was initiated to identify sediment characteristics, monitor sediment transport, and predict sediment resuspension and deposition under varying hydraulic conditions. The mathematical model SEDMOD was used to simulate streamflow and sediment transport using three modeling scenarios: (1) sediment transport simulations for 730 days (Jan. 2001 to Dec. 2002), with existing dam structures, (2) sediment transport simulations based on flows from the 1947 flood at the Kalamazoo River with existing dam structures, and (3) sediment transport simulations based on flows from the 1947 flood at the Kalamazoo River with dams removed. Sediment transport simulations based on the 1947 flood hydrograph provide an estimate of sediment transport rates under maximum flow conditions. These scenarios can be used as an assessment of the sediment load that may erode from the study reach at this flow magnitude during a dam failure. The model was calibrated using suspended sediment as a calibration parameter and root mean squared error (RMSE) as an objective function. Analyses of the calibrated model show a slight bias in the model results at flows higher than 75 m3/s; this means that the model-simulated suspended-sediment transport rates are higher than the observed rates; however, the overall calibrated model results show close agreement between simulated and measured values of suspended sediment. Simulation results show that the Kalamazoo River sediment transport mechanism is in a dynamic equilibrium state. Model results during the 730-day simulations indicate significant sediment erosion from the study reach at flow rates higher than 55 m3/s. Similarly, significant sediment deposition occurs during low to average flows (monthly mean flows between 25.49 m3/s and 50.97 m3/s) after a high-flow event. If the flow continues to stay in the low to average range the system shifts towards equilibrium, resulting in a balancing effect between sediment deposition and erosion rates. The 1947 flood-flow simulations show approximately 30,000 m3 more instream sediments erosion for the first 21 days of the dams removed scenario than for the existing-dams scenario, with the same initial conditions for both scenarios. Application of a locally weighted regression smoothing (LOWESS) function to simulation results of the dams removed scenario indicates a steep downtrend with high sediment transport rates during the first 21 days. In comparison, the LOWESS curve for the existing-dams scenario shows a smooth transition of sediment transport rates in response to the change in streamflow. The high erosion rates during the dams-removed scenario are due to the absence of the dams; in contrast, the presence of dams in the existing-dams scenario helps reduce sediment erosion to some extent. The overall results of 60-day simulations for the 1947 flood show no significant difference in total volume of eroded sediment between the two scenarios, because the dams in the study reach have low heads and no control gates. It is important to note that the existing-dams and dams-removed scenarios simulations are run for only 60 days; therefore, the simulations take into account the changes in sediment erosion and deposition rates only during that time period. Over an extended period, more erosion of instream sediments would be expected to occur if the dams are not properly removed than under the existing conditions. On the basis of model simulations, removal of dams would further lower the head in all the channels. This lowering of head could produce higher flow velocities in the study reach, which ultimately would result in accelerated erosion rates.

Effects of massive wind power integration on short-term water resource management in central Chile - a grid-wide study

NASA Astrophysics Data System (ADS)

Haas, J.; Olivares, M. A.; Palma, R.

2013-12-01

In central Chile, water from reservoirs and streams is mainly used for irrigation and power generation. Hydropower reservoirs operation is particularly challenging because: i) decisions at each plant impact the entire power system, and ii) the existence of large storage capacity implies inter-temporal ties. An Independent System Operator (ISO) decides the grid-wide optimal allocation of water for power generation, under irrigation-related constraints. To account for the long-term opportunity cost of water, a future cost function is determined and used in the short term planning. As population growth and green policies demand increasing levels of renewable energy in power systems, deployment of wind farms and solar plants is rising quickly. However, their power output is highly fluctuating on short time scales, affecting the operation of power plants, particularly those fast responding units as hydropower reservoirs. This study addresses these indirect consequences of massive introduction of green energy sources on reservoir operations. Short-term reservoir operation, under different wind penetration scenarios, is simulated using a replica of Chile's ISO's scheduling optimization tools. Furthermore, an ongoing study is exploring the potential to augment the capacity the existing hydro-power plants to better cope with the balancing needs due to a higher wind power share in the system. As reservoir releases determine to a great extent flows at downstream locations, hourly time series of turbined flows for 24-hour periods were computed for selected combinations between new wind farms and increased capacity of existing hydropower plants. These time series are compiled into subdaily hydrologic alteration (SDHA) indexes (Zimmerman et al, 2010). The resulting sample of indexes is then analyzed using duration curves. Results show a clear increase in the SDHA for every reservoir of the system as more fluctuating renewables are integrated into the system. High-fluctuation events become more frequent. While the main load-following reservoirs are very susceptible to even small levels of additional wind power, the remaining withstand greater amounts before producing a significant SDHA. The additional effect of augmented installed capacity of existing hydropower plants on the SDHA is modest. The increase in SDHA calls for alternative operational constraints beyond the current practice based exclusively on minimum instream flows. Previous research by this group has shown the potential of maximum ramping rates constraints to efficiently achieve improvement in the SDHA. This alternative is being studied as part of a project currently in progress. This may contribute to make hydropower projects more socially acceptable and environmentally sound.

Isolating causal pathways between flow and fish in the regulated river hierarchy

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

McManamay, Ryan A.; Peoples, Brandon K.; Orth, Donald J.

Unregulated river systems are organized in a hierarchy in which large-scale factors (i.e., landscape and segment scales) influence local habitats (i.e., reach, meso-, and microhabitat scales), and both differentially exert selective pressures on biota. Dams, however, create discontinua in these processes and change the hierarchical structure. We examined the relative roles of hydrology and other instream factors, within a hierarchical landscape context, in organizing fish communities in regulated and unregulated tributaries to the Upper Tennessee River, USA. We also used multivariate regression trees to identify factors that partition fish assemblages based on trait similarities, irrespective of spatial scale. Then, wemore » used classical path analysis and structural equation modeling to evaluate the most plausible hierarchical causal structure of specific trait-based community components, given the data. Both statistical approaches suggested that river regulation affects stream fishes through a variety of reach-scale variables, not always through hydrology itself. Though we observed different changes in flow, temperature, and biotic responses according to regulation types, the most predominant path in which dam regulation affected biota was via temperature alterations. Diversion dams had the strongest effects on fish assemblages. Diversion dams reduced flow magnitudes, leading to declines in fish richness but increased temperatures, leading to lower abundances in equilibrium species and nest guarders. Peaking and run-of-river dams increased flow variability, leading to lower abundances in nest-guarding fishes. Flow displayed direct relationships with biotic responses; however, results indicated that changes in temperature and substrate had equal, if not stronger, effects on fish assemblage composition. The strength and nature of relationships depended on whether flow metrics were standardized for river size. Here, we suggest that restoration efforts in regulated rivers focus on improving flow conditions in conjunction with temperature and substrate restoration.« less

Isolating causal pathways between flow and fish in the regulated river hierarchy

DOE PAGES

McManamay, Ryan A.; Peoples, Brandon K.; Orth, Donald J.; ...

2015-07-07

Unregulated river systems are organized in a hierarchy in which large-scale factors (i.e., landscape and segment scales) influence local habitats (i.e., reach, meso-, and microhabitat scales), and both differentially exert selective pressures on biota. Dams, however, create discontinua in these processes and change the hierarchical structure. We examined the relative roles of hydrology and other instream factors, within a hierarchical landscape context, in organizing fish communities in regulated and unregulated tributaries to the Upper Tennessee River, USA. We also used multivariate regression trees to identify factors that partition fish assemblages based on trait similarities, irrespective of spatial scale. Then, wemore » used classical path analysis and structural equation modeling to evaluate the most plausible hierarchical causal structure of specific trait-based community components, given the data. Both statistical approaches suggested that river regulation affects stream fishes through a variety of reach-scale variables, not always through hydrology itself. Though we observed different changes in flow, temperature, and biotic responses according to regulation types, the most predominant path in which dam regulation affected biota was via temperature alterations. Diversion dams had the strongest effects on fish assemblages. Diversion dams reduced flow magnitudes, leading to declines in fish richness but increased temperatures, leading to lower abundances in equilibrium species and nest guarders. Peaking and run-of-river dams increased flow variability, leading to lower abundances in nest-guarding fishes. Flow displayed direct relationships with biotic responses; however, results indicated that changes in temperature and substrate had equal, if not stronger, effects on fish assemblage composition. The strength and nature of relationships depended on whether flow metrics were standardized for river size. Here, we suggest that restoration efforts in regulated rivers focus on improving flow conditions in conjunction with temperature and substrate restoration.« less

Method and system for gas flow mitigation of molecular contamination of optics

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

Delgado, Gildardo; Johnson, Terry; Arienti, Marco

A computer-implemented method for determining an optimized purge gas flow in a semi-conductor inspection metrology or lithography apparatus, comprising receiving a permissible contaminant mole fraction, a contaminant outgassing flow rate associated with a contaminant, a contaminant mass diffusivity, an outgassing surface length, a pressure, a temperature, a channel height, and a molecular weight of a purge gas, calculating a flow factor based on the permissible contaminant mole fraction, the contaminant outgassing flow rate, the channel height, and the outgassing surface length, comparing the flow factor to a predefined maximum flow factor value, calculating a minimum purge gas velocity and amore » purge gas mass flow rate from the flow factor, the contaminant mass diffusivity, the pressure, the temperature, and the molecular weight of the purge gas, and introducing the purge gas into the semi-conductor inspection metrology or lithography apparatus with the minimum purge gas velocity and the purge gas flow rate.« less

Low transient storage and uptake efficiencies in seven agricultural streams: implications for nutrient demand

USGS Publications Warehouse

Sheibley, Rich W.; Duff, John H.; Tesoriero, Anthony J.

2014-01-01

We used mass load budgets, transient storage modeling, and nutrient spiraling metrics to characterize nitrate (NO3−), ammonium (NH4+), and inorganic phosphorus (SRP) demand in seven agricultural streams across the United States and to identify in-stream services that may control these conditions. Retention of one or all nutrients was observed in all but one stream, but demand for all nutrients was low relative to the mass in transport. Transient storage metrics (As/A, Fmed200, Tstr, and qs) correlated with NO3− retention but not NH4+ or SRP retention, suggesting in-stream services associated with transient storage and stream water residence time could influence reach-scale NO3− demand. However, because the fraction of median reach-scale travel time due to transient storage (Fmed200) was ≤1.2% across the sites, only a relatively small demand for NO3− could be generated by transient storage. In contrast, net uptake of nutrients from the water column calculated from nutrient spiraling metrics were not significant at any site because uptake lengths calculated from background nutrient concentrations were statistically insignificant and therefore much longer than the study reaches. These results suggest that low transient storage coupled with high surface water NO3− inputs have resulted in uptake efficiencies that are not sufficient to offset groundwater inputs of N. Nutrient retention has been linked to physical and hydrogeologic elements that drive flow through transient storage areas where residence time and biotic contact are maximized; however, our findings indicate that similar mechanisms are unable to generate a significant nutrient demand in these streams relative to the loads.

A Bayesian methodological framework for accommodating interannual variability of nutrient loading with the SPARROW model

NASA Astrophysics Data System (ADS)

Wellen, Christopher; Arhonditsis, George B.; Labencki, Tanya; Boyd, Duncan

2012-10-01

Regression-type, hybrid empirical/process-based models (e.g., SPARROW, PolFlow) have assumed a prominent role in efforts to estimate the sources and transport of nutrient pollution at river basin scales. However, almost no attempts have been made to explicitly accommodate interannual nutrient loading variability in their structure, despite empirical and theoretical evidence indicating that the associated source/sink processes are quite variable at annual timescales. In this study, we present two methodological approaches to accommodate interannual variability with the Spatially Referenced Regressions on Watershed attributes (SPARROW) nonlinear regression model. The first strategy uses the SPARROW model to estimate a static baseline load and climatic variables (e.g., precipitation) to drive the interannual variability. The second approach allows the source/sink processes within the SPARROW model to vary at annual timescales using dynamic parameter estimation techniques akin to those used in dynamic linear models. Model parameterization is founded upon Bayesian inference techniques that explicitly consider calibration data and model uncertainty. Our case study is the Hamilton Harbor watershed, a mixed agricultural and urban residential area located at the western end of Lake Ontario, Canada. Our analysis suggests that dynamic parameter estimation is the more parsimonious of the two strategies tested and can offer insights into the temporal structural changes associated with watershed functioning. Consistent with empirical and theoretical work, model estimated annual in-stream attenuation rates varied inversely with annual discharge. Estimated phosphorus source areas were concentrated near the receiving water body during years of high in-stream attenuation and dispersed along the main stems of the streams during years of low attenuation, suggesting that nutrient source areas are subject to interannual variability.

Comparison of Methylmercury Production and Accumulation in Sediments of the Congaree and Edisto River Basins, South Carolina, 2004-06

USGS Publications Warehouse

Bradley, Paul M.; Chapelle, Francis H.; Journey, Celeste A.

2009-01-01

Fish-tissue mercury concentrations (approximately 2 micrograms per gram) in the Edisto River basin of South Carolina are among the highest recorded in the United States. Substantially lower mercury concentrations (approximately 0.2 microgram per gram) are reported in fish from the adjacent (about 30 kilometer) Congaree River basin and the Congaree National Park. In contrast, concentrations of total mercury were statistically higher in sediments from the Congaree River compared with those in sediments from the Edisto River. Furthermore, no statistically significant difference was observed in concentrations of methylmercury or net methylation potential in sediments collected from various Edisto and Congaree hydrologic settings. In both systems, the net methylation potential was low (0-0.17 nanogram per gram per day) for in-stream sediments exposed to continuously flowing water but substantially higher (about 1.8 nanograms per gram per day) in wetland sediments exposed to standing water. These results are not consistent with the hypothesis that differences in fish-tissue mercury between the Edisto and Congaree basins reflect fundamental differences in the potential for each system to methylate mercury. Rather, the significantly higher ratios of methylmercury to total mercury observed in the Edisto system suggest that the net accumulation and(or) preservation of methylmercury are greater in the Edisto system. The marked differences in net methylation potential observed between the wetland and in-stream settings suggest the hypothesis that methylmercury transport from zones of production (wetlands) to points of entry into the food chain (channels) may contribute to the observed differences in fish-tissue mercury concentrations between the two river systems.

Climate change and watershed mercury export: a multiple projection and model analysis.

PubMed

Golden, Heather E; Knightes, Christopher D; Conrads, Paul A; Feaster, Toby D; Davis, Gary M; Benedict, Stephen T; Bradley, Paul M

2013-09-01

Future shifts in climatic conditions may impact watershed mercury (Hg) dynamics and transport. An ensemble of watershed models was applied in the present study to simulate and evaluate the responses of hydrological and total Hg (THg) fluxes from the landscape to the watershed outlet and in-stream THg concentrations to contrasting climate change projections for a watershed in the southeastern coastal plain of the United States. Simulations were conducted under stationary atmospheric deposition and land cover conditions to explicitly evaluate the effect of projected precipitation and temperature on watershed Hg export (i.e., the flux of Hg at the watershed outlet). Based on downscaled inputs from 2 global circulation models that capture extremes of projected wet (Community Climate System Model, Ver 3 [CCSM3]) and dry (ECHAM4/HOPE-G [ECHO]) conditions for this region, watershed model simulation results suggest a decrease of approximately 19% in ensemble-averaged mean annual watershed THg fluxes using the ECHO climate-change model and an increase of approximately 5% in THg fluxes with the CCSM3 model. Ensemble-averaged mean annual ECHO in-stream THg concentrations increased 20%, while those of CCSM3 decreased by 9% between the baseline and projected simulation periods. Watershed model simulation results using both climate change models suggest that monthly watershed THg fluxes increase during the summer, when projected flow is higher than baseline conditions. The present study's multiple watershed model approach underscores the uncertainty associated with climate change response projections and their use in climate change management decisions. Thus, single-model predictions can be misleading, particularly in developmental stages of watershed Hg modeling. Copyright © 2013 SETAC.

Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

USGS Publications Warehouse

Ciparis, S.; Iwanowicz, L.R.; Voshell, J.R.

2012-01-01

Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO 4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17??-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations >1ng/L. Relatively high concentrations of DIN (>1000??g/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R 2=0.56-0.81) and E2Eq (R 2=0.39-0.75). Relationships between watershed densities of AFOs and PO 4-P were weaker, but were also significant (R 2=0.27-0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO 4-P than streams without WWTP discharges, and PO 4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms. ?? 2011 Elsevier B.V.

Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

USGS Publications Warehouse

Ciparis, Serena; Iwanowicz, Luke R.; Voshell, J. Reese

2012-01-01

Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations > 1 ng/L. Relatively high concentrations of DIN (> 1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R2 = 0.56–0.81) and E2Eq (R2 = 0.39–0.75). Relationships between watershed densities of AFOs and PO4-P were weaker, but were also significant (R2 = 0.27–0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO4-P than streams without WWTP discharges, and PO4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms.

Evaluating turbidity and suspended-sediment concentration relations from the North Fork Toutle River basin near Mount St. Helens, Washington; annual, seasonal, event, and particle size variations - a preliminary analysis.

USGS Publications Warehouse

Uhrich, Mark A.; Spicer, Kurt R.; Mosbrucker, Adam; Christianson, Tami

2015-01-01

Regression of in-stream turbidity with concurrent sample-based suspended-sediment concentration (SSC) has become an accepted method for producing unit-value time series of inferred SSC (Rasmussen et al., 2009). Turbidity-SSC regression models are increasingly used to generate suspended-sediment records for Pacific Northwest rivers (e.g., Curran et al., 2014; Schenk and Bragg, 2014; Uhrich and Bragg, 2003). Recent work developing turbidity-SSC models for the North Fork Toutle River in Southwest Washington (Uhrich et al., 2014), as well as other studies (Landers and Sturm, 2013, Merten et al., 2014), suggests that models derived from annual or greater datasets may not adequately reflect shorter term changes in turbidity-SSC relations, warranting closer inspection of such relations. In-stream turbidity measurements and suspended-sediment samples have been collected from the North Fork Toutle River since 2010. The study site, U.S. Geological Survey (USGS) streamgage 14240525 near Kid Valley, Washington, is 13 river km downstream of the debris avalanche emplaced by the 1980 eruption of Mount St. Helens (Lipman and Mullineaux, 1981), and 2 river km downstream of the large sediment retention structure (SRS) built from 1987–1989 to mitigate the associated sediment hazard. The debris avalanche extends roughly 25 km down valley from the edifice of the volcano and is the primary source of suspended sediment moving past the streamgage (NF Toutle-SRS). Other significant sources are debris flow events and sand deposits upstream of the SRS, which are periodically remobilized and transported downstream. Also, finer material often is derived from the clay-rich original debris avalanche deposit, while coarser material can derive from areas such as fluvially reworked terraces.

Erosion rills offset the efficacy of vegetated buffer strips to mitigate pesticide exposure in surface waters.

PubMed

Stehle, Sebastian; Dabrowski, James Michael; Bangert, Uli; Schulz, Ralf

2016-03-01

Regulatory risk assessment considers vegetated buffer strips as effective risk mitigation measures for the reduction of runoff-related pesticide exposure of surface waters. However, apart from buffer strip widths, further characteristics such as vegetation density or the presence of erosion rills are generally neglected in the determination of buffer strip mitigation efficacies. This study conducted a field survey of fruit orchards (average slope 3.1-12.2%) of the Lourens River catchment, South Africa, which specifically focused on the characteristics and attributes of buffer strips separating orchard areas from tributary streams. In addition, in-stream and erosion rill water samples were collected during three runoff events and GIS-based modeling was employed to predict losses of pesticides associated with runoff. The results show that erosion rills are common in buffer strips (on average 13 to 24 m wide) of the tributaries (up to 6.5 erosion rills per km flow length) and that erosion rills represent concentrated entry pathways of pesticide runoff into the tributaries during rainfall events. Exposure modeling shows that measured pesticide surface water concentrations correlated significantly (R(2)=0.626; p<0.001) with runoff losses predicted by the modeling approach in which buffer strip width was set to zero at sites with erosion rills; in contrast, no relationship between predicted runoff losses and in-stream pesticide concentrations were detected in the modeling approach that neglected erosion rills and thus assumed efficient buffer strips. Overall, the results of our study show that erosion rills may substantially reduce buffer strip pesticide retention efficacies during runoff events and suggest that the capability of buffer strips as a risk mitigation tool for runoff is largely overestimated in current regulatory risk assessment procedures conducted for pesticide authorization. Copyright © 2015 Elsevier B.V. All rights reserved.

Magnitude and frequency of low flows in the Suwannee River Water Management District, Florida

USGS Publications Warehouse

Giese, G.L.; Franklin, M.A.

1996-01-01

Low-flow frequency statistics for 20 gaging stations having at least 10 years of continuous record and 31 other stations having less than 10 years of continu ous record or a series of at least two low- flow measurements are presented for unregulated streams in the Suwannee River Water Management District in north-central Florida. Statistics for the 20 continuous-record stations included are the annual and monthly minimum consecutive-day average low- flow magnitudes for 1, 3, 7, 14, and 30 consecutive days for recurrence intervals of 2, 5, 10, 20, and, for some long-term stations, 50 years, based on records available through the 1994 climatic year.Only theannual statistics are given for the 31 other stations; these are for the 7- and 30-consecutive day periods only and for recurrence intervals of 2 and 10 years only. Annual low-flow frequency statistics range from zero for many small streams to 5,500 cubic feet per second for the annual 30- consecutive-day average flow with a recurrenceinterval of 2 years for the Suwannee River near Wilcox (station 02323500). Monthly low-flow frequency statistics range from zero for many small streams to 13,800 cubic feet per second for the minimum 30-consecutive-day average flow with a 2-year recurrence interval for the month of March for the same station. Generally, low-flow characteristics of streams in the Suwannee River Water Management District are controlled by climatic, topographic, and geologic fac tors. The carbonate Floridan aquifer system underlies, or is at the surface of, the entire District. The terrane's karstic nature results in manysinkholes and springs. In some places, springs may contribute greatly to low streamflow and the contributing areas of such springs may include areasoutside the presumed surface drainage area of the springs. In other places, water may enter sinkholes within a drainage basin, then reappear in springs downstream from a gage. Many of the smaller streams in the District go dry or have no flow forseveral months in many years. In addition to the low-flow statistics, four synoptic low-flow measurement surveys were conducted on 161 sites during 1990, 1995, and 1996. Themeasurements were made to provide "snapshots" of flow conditions of streams throughout the Suwannee River Water Management District. Magnitudes of low flows during the 1990 series of measurements were in the range associated withminimum 7-consecutive-day 50-year recurrence interval to the minimum 7-consecutive-day 20-year recurrence interval, except in Taylor and Dixie Counties, where the magnitudes ranged from the minimum 7-consecutive-day 5-year flow level to the7-consecutive-day 2-year flow level. The magnitudes were all greater than the minimum 7- consecutive-day 2-year flow level during 1995 and 1996. Observations of no flow were recorded at many of the sites for all four series of measurements.

Model of Transition from Laminar to Turbulent Flow

NASA Astrophysics Data System (ADS)

Kanda, Hidesada

2001-11-01

For circular pipe flows, a model of transition from laminar to turbulent flow has already been proposed and the minimum critical Reynolds number of approximately 2040 was obtained (Kanda, 1999). In order to prove the validity of the model, another verification is required. Thus, for plane Poiseuille flow, results of previous investigations were studied, focusing on experimental data on the critical Reynolds number Rc, the entrance length, and the transition length. Consequently, concerning the natural transition, it was confirmed from the experimental data that (i) the transition occurs in the entrance region, (ii) Rc increases as the contraction ratio in the inlet section increases, and (iii) the minimum Rc is obtained when the contraction ratio is the smallest or one, and there is no-bellshaped entrance or straight parallel plates. Its value exists in the neighborhood of 1300, based on the channel height and the average velocity. Although, for Hagen-Poiseuille flow, the minimum Rc is approximately 2000, based on the pipe diameter and the average velocity, there seems to be no significant difference in the transition from laminar to turbulent flow between Hagen-Poiseuille flow and plane Poiseuille flow (Kanda, 2001). Rc is determined by the shape of the inlet. Kanda, H., 1999, Proc. of ASME Fluids Engineering Division - 1999, FED-Vol. 250, pp. 197-204. Kanda, H., 2001, Proc. of ASME Fluids Engineering Division - 2001.

Nutrient concentrations and loads in the northeastern United States - Status and trends, 1975-2003

USGS Publications Warehouse

Trench, Elaine C. Todd; Moore, Richard B.; Ahearn, Elizabeth A.; Mullaney, John R.; Hickman, R. Edward; Schwarz, Gregory E.

2012-01-01

The U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) began regional studies in 2003 to synthesize information on nutrient concentrations, trends, stream loads, and sources. In the northeastern United States, a study area that extends from Maine to central Virginia, nutrient data were evaluated for 130 USGS water-quality monitoring stations. Nutrient data were analyzed for trends in flow-adjusted concentrations, modeled instream (non-flow-adjusted) concentrations, and stream loads for 32 stations with 22 to 29 years of water-quality and daily mean streamflow record during 1975-2003 (termed the long-term period), and for 46 stations during 1993-2003 (termed the recent period), by using a coupled statistical model of streamflow and water quality developed by the USGS. Recent trends in flow-adjusted concentrations of one or more nutrients also were analyzed for 90 stations by using Tobit regression. Annual stream nutrient loads were estimated, and annual nutrient yields were calculated, for 47 stations for the long-term and recent periods, and for 37 additional stations that did not have a complete streamflow and water-quality record for 1993-2003. Nutrient yield information was incorporated for 9 drainage basins evaluated in a national NAWQA study, for a total of 93 stations evaluated for nutrient yields. Long-term downward trends in flow-adjusted concentrations of total nitrogen and total phosphorus (18 and 19 of 32 stations, respectively) indicate regional improvements in nutrient-related water-quality conditions. Most of the recent trends detected for total phosphorus were upward (17 of 83 stations), indicating possible reversals to the long-term improvements. Concentrations of nutrients in many streams persist at levels that are likely to affect aquatic habitat adversely and promote freshwater or coastal eutrophication. Recent trends for modeled instream concentrations, and modeled reference concentrations, were evaluated relative to ecoregion-based nutrient criteria proposed by the U.S. Environmental Protection Agency. Instream concentrations of total nitrogen and total phosphorus persist at levels higher than proposed criteria at more than one-third and about one-half, respectively, of the 46 stations analyzed. Long-term trends in nutrient loads were primarily downward, with downward trends in total nitrogen and total phosphorus loads detected at 12 and 17 of 32 stations, respectively. Upward trends were rare, with one upward trend for total nitrogen loads and none for total phosphorus. Trends in loads of nitrite-plus-nitrate nitrogen included 7 upward and 8 downward trends among 32 stations. Downward trends in loads of ammonia nitrogen and total Kjeldahl nitrogen were detected at all six stations evaluated. Long-term downward trends detected in four of the five largest drainage basins evaluated include: total nitrogen loads for the Connecticut, Delaware, and James Rivers; total Kjeldahl nitrogen and ammonia nitrogen loads for the Susquehanna River; ammonia nitrogen and nitrite-plus-nitrate nitrogen loads for the James River; and total phosphorus loads for the Connecticut and Delaware Rivers. No trends in load were detected for the Potomac River. Nutrient yields were evaluated relative to the extent of land development in 93 drainage basins. The undeveloped land-use category included forested drainage basins with undeveloped land ranging from 75 to 100 percent of basin area. Median total nitrogen yields for the 27 undeveloped drainage basins evaluated, including 9 basins evaluated in a national NAWQA study, ranged from 290 to 4,800 pounds per square mile per year (lb/mi2/yr). Total nitrogen yields even in the most pristine drainage basins may be elevated relative to natural conditions, because of high rates of atmospheric deposition of nitrogen in parts of the northeastern United States. Median total phosphorus yields ranged from 12 to 330 lb/mi2/yr for the 26 undeveloped basins evaluated. The undeveloped category includes some large drainage basins with point-source discharges and small percentages of developed land; in these basins, streamflow from undeveloped headwater areas dilutes streamflow in more urbanized reaches, and dampens but does not eliminate the point-source "signal" of higher nutrient loads. Median total nitrogen yields generally do not exceed 1,700 lb/mi2/yr, and median total phosphorus yields generally do not exceed 100 lb/mi2/yr, in the drainage basins that are least affected by human land-use and waste-disposal practices. Agricultural and urban land use has increased nutrient yields substantially relative to undeveloped drainage basins. Median total nitrogen yields for 24 agricultural basins ranged from 1,700 to 26,000 lb/mi2/yr, and median total phosphorus yields ranged from 94 to 1,000 lb/mi2/yr. The maximum estimated total nitrogen and total phosphorus yields, 32,000 and 16,000 lb/mi2/yr, respectively, for all stations in the region were in small (less than 50 square miles (mi2)) agricultural drainage basins. Median total nitrogen yields ranged from 1,400 to 17,000 lb/mi2/yr in 26 urbanized drainage basins, and median total phosphorus yields ranged from 43 to 1,900 lb/mi2/yr. Urbanized drainage basins with the highest nutrient yields are generally small (less than 300 mi2) and are drained by streams that receive major point-source discharges. Instream nutrient loads were evaluated relative to loads from point-source discharges in four drainage basins: the Quinebaug River Basin in Connecticut, Massachusetts, and Rhode Island; the Raritan River Basin in New Jersey; the Patuxent River Basin in Maryland; and the James River Basin in Virginia. Long-term downward trends in nutrient loads, coupled with similar trends in flow-adjusted nutrient concentrations, indicate long-term reductions in the delivery of most nutrients to these streams. However, the absence of recent downward trends in load for most nutrients, coupled with instream concentrations that exceed proposed nutrient criteria in several of these waste-receiving streams, indicates that challenges remain in reducing delivery of nutrients to streams from point sources. During dry years, the total nutrient load from point sources in some of the drainage basins approached or equaled the nutrient load transported by the stream.

An integrated Riverine Environmental Flow Decision Support System (REFDSS) to evaluate the ecological effects of alternative flow scenarios on river ecosystems

USGS Publications Warehouse

Maloney, Kelly O.; Talbert, Colin B.; Cole, Jeffrey C.; Galbraith, Heather S.; Blakeslee, Carrie J.; Hanson, Leanne; Holmquist-Johnson, Christopher L.

2015-01-01

In regulated rivers, managers must evaluate competing flow release scenarios that attempt to balance both human and natural needs. Meeting these natural flow needs is complex due to the myriad of interacting physical and hydrological factors that affect ecosystems. Tools that synthesize the voluminous scientific data and models on these factors will facilitate management of these systems. Here, we present the Riverine Environmental Flow Decision Support System (REFDSS), a tool that enables evaluation of competing flow scenarios and other variables on instream habitat. We developed a REFDSS for the Upper Delaware River, USA, a system that is regulated by three headwater reservoirs. This version of the REFDSS has the ability to integrate any set of spatially explicit data and synthesizes modeled discharge for three competing management scenarios, flow-specific 2-D hydrodynamic modeled estimates of local hydrologic conditions (e.g., depth, velocity, shear stress, etc.) at a fine pixel-scale (1 m2), and habitat suitability criteria (HSC) for a variety of taxa. It contains all individual model outputs, computationally integrates these data, and outputs the amount of potentially available habitat for a suite of species of interest under each flow release scenario. Users have the flexibility to change the time period of interest and vary the HSC. The REFDSS was developed to enable side-by-side evaluation of different flow management scenarios and their effects on potential habitat availability, allowing managers to make informed decisions on the best flow scenarios. An exercise comparing two alternative flow scenarios to a baseline scenario for several key species is presented. The Upper Delaware REFDSS was robust to minor changes in HSC (± 10 %). The general REFDSS platform was developed as a user-friendly Windows desktop application that was designed to include other potential parameters of interest (e.g., temperature) and for transferability to other riverine systems.

Airfoil profiles for minimum pressure drag at supersonic velocities -- general analysis with application to linearized supersonic flow

NASA Technical Reports Server (NTRS)

Chapman, Dean R

1952-01-01

A theoretical investigation is made of the airfoil profile for minimum pressure drag at zero lift in supersonic flow. In the first part of the report a general method is developed for calculating the profile having the least pressure drag for a given auxiliary condition, such as a given structural requirement or a given thickness ratio. The various structural requirements considered include bending strength, bending stiffness, torsional strength, and torsional stiffness. No assumption is made regarding the trailing-edge thickness; the optimum value is determined in the calculations as a function of the base pressure. To illustrate the general method, the optimum airfoil, defined as the airfoil having minimum pressure drag for a given auxiliary condition, is calculated in a second part of the report using the equations of linearized supersonic flow.

Characteristics of suspended sediment and river discharge during the beginning of snowmelt in volcanically active mountainous environments

NASA Astrophysics Data System (ADS)

Mouri, Goro; Ros, Faizah Che; Chalov, Sergey

2014-05-01

To better understand instream suspended sediment delivery and transformation processes, we conducted field measurements and laboratory experiments to study the natural function of spatial and temporal variation, sediment particles, stable isotopes, particle size, and aspect ratio from tributary to mainstream flows of the Sukhaya Elizovskaya River catchment at the beginning of and during snowmelt. The Sukhaya Elizovskaya River is located in the Kamchatka Peninsula of Russia and is surrounded by active volcanic territory. The study area has a range of hydrological features that determine the extreme amounts of washed sediments. Sediment transported to the river channels in volcanic mountainous terrain is believed to be strongly influenced by climate conditions, particularly when heavy precipitation and warmer climate trigger mudflows in association with the melting snow. The high porosity of the channel bottom material also leads to interactions with the surface water, causing temporal variability in the daily fluctuations in water and sediment flow. Field measurements revealed that suspended sediment behaviour and fluxes decreased along the mainstream Sukhaya Elizovskaya River from inflows from a tributary catchment located in the volcanic mountain range. In laboratory experiments, water samples collected from tributaries were mixed with those from the mainstream flow of the Sukhaya Elizovskaya River to examine the cause of debris flow and characteristics of suspended sediment in the mainstream. These findings and the geological conditions of the tributary catchments studied led us to conclude that halloysite minerals likely comprise the majority of suspended sediments and play a significant role in phosphate adsorption. The experimental results were upscaled and verified using field measurements. Our results indicate that the characteristics of suspended sediment and river discharge in the Sukhaya Elizovskaya River can be attributed primarily to the beginning of snowmelt in volcanic tributaries of the lahar valley, suggesting a significant hydrological contribution of volcanic catchments to instream suspended sediment transport. Daily fluctuations in discharge caused by snowmelt with debris flow were observed in this measurement period, in which suspended sediment concentration is ~ 10 mg/l during nonflooding periods and ~ 1400 mg/l when flooding occurs. The oxygen and hydrogen isotope measurements, when compared with Japan, indicated that the Kamchatka region water is relatively lightweight, incorporating the effects of topography; and the water from the beginning of the snowmelt is relatively lightweight when compared with water from the end of the snowmelt. The trend line of isotopes from the beginning of the snowmelt was defined by a slope of 6.88 (n = 12; r2 = 0.97), significantly less than that of isotopes from the snowmelt (8.72). The sediment particles collected during the snowmelt were round in shape caused by the extreme flows and high discharge. The shape of the sediment particles collected at the beginning of the snowmelt, assumed to be fresh samples from the hillslope, was sharper caused by the relatively small discharge by moderate snowmelt. Finally, the relationship between river discharge and suspended sediment concentration was indicated. The results are compared with mountainous rivers of Japan and Malaysia. A new diagram is proposed to describe the relationship between suspended sediment concentration and river discharge.

Disentangling the role of athermal walls on the Knudsen paradox in molecular and granular gases

NASA Astrophysics Data System (ADS)

Gupta, Ronak; Alam, Meheboob

2018-01-01

The nature of particle-wall interactions is shown to have a profound impact on the well-known "Knudsen paradox" [or the "Knudsen minimum" effect, which refers to the decrease of the mass-flow rate of a gas with increasing Knudsen number Kn, reaching a minimum at Kn˜O (1 ) and increasing logarithmically with Kn as Kn→∞ ] in the acceleration-driven Poiseuille flow of rarefied gases. The nonmonotonic variation of the flow rate with Kn occurs even in a granular or dissipative gas in contact with thermal walls. The latter result is in contradiction with recent work [Alam et al., J. Fluid Mech. 782, 99 (2015), 10.1017/jfm.2015.523] that revealed the absence of the Knudsen minimum in granular Poiseuille flow for which the flow rate was found to decrease at large values of Kn. The above conundrum is resolved by distinguishing between "thermal" and "athermal" walls, and it is shown that, for both molecular and granular gases, the momentum transfer to athermal walls is much different than that to thermal walls which is directly responsible for the anomalous flow-rate variation with Kn in the rarefied regime. In the continuum limit of Kn→0 , the athermal walls are shown to be closely related to "no-flux" ("adiabatic") walls for which the Knudsen minimum does not exist either. A possible characterization of athermal walls in terms of (1) an effective specularity coefficient for the slip velocity and (2) a flux-type boundary condition for granular temperature is suggested based on simulation results.

Occurrence and sources of Escherichia coli in metropolitan St. Louis streams, October 2004 through September 2007

USGS Publications Warehouse

Wilkison, Donald H.; Davis, Jerri V.

2010-01-01

The occurrence and sources of Escherichia coli (E. coli), one of several fecal indicator bacteria, in metropolitan St. Louis streams known to receive nonpoint source runoff, occasional discharges from combined and sanitary sewers, and treated wastewater effluent were investigated from October 2004 through September 2007. Three Missouri River sites, five Mississippi River sites, and six small basin tributary stream sites were sampled during base flow and storm events for the presence of E. coli and their sources. E. coli host-source determinations were conducted using local library based genotypic methods. Human fecal contamination in stream samples was additionally confirmed by the presence of Bacteroides thetaiotaomicron, an anaerobic, enteric bacterium with a high occurrence in, and specificity to, humans. Missouri River E. coli densities and loads during base flow were approximately 10 times greater than those in the Mississippi River above its confluence with the Missouri River. Although substantial amounts of E. coli originated from within the study area during base flow and storm events, considerable amounts of E. coli in the Missouri River, as well as in the middle Mississippi River sections downstream from its confluence with the Missouri River, originated in Missouri River reaches upstream from the study area. In lower Mississippi River reaches, bacteria contributions from the numerous combined and sanitary sewer overflows within the study area, as well as contributions from nonpoint source runoff, greatly increased instream E. coli densities. Although other urban factors cannot be discounted, average E. coli densities in streams were strongly correlated with the number of upstream combined and sanitary sewer overflow points, and the percentage of upstream impervious cover. Small basin sites with the greatest number of combined and sanitary sewer overflows (Maline Creek and the River des Peres) had larger E. coli densities, larger loads, and a greater percentage of E. coli attributable to humans than other small basin sites; however, even though small basin E. coli densities typically were much larger than in large river receiving streams, small basins contributed, on average, only a small part (a maximum of 16 percent) of the total E. coli load to larger rivers. On average, approximately one-third of E. coli in metropolitan St. Louis streams was identified as originating from humans. Another one-third of the E. coli was determined to have originated from unidentified sources; dogs and geese contributed lesser amounts, 10 and 20 percent, of the total instream bacteria. Sources of E. coli were largely independent of hydrologic conditions-an indication that sources remained relatively consistent with time.

Estimation of additive forces and moments for supersonic inlets

NASA Technical Reports Server (NTRS)

Perkins, Stanley C., Jr.; Dillenius, Marnix F. E.

1991-01-01

A technique for estimating the additive forces and moments associated with supersonic, external compression inlets as a function of mass flow ratio has been developed. The technique makes use of a low order supersonic paneling method for calculating minimum additive forces at maximum mass flow conditions. A linear relationship between the minimum additive forces and the maximum values for fully blocked flow is employed to obtain the additive forces at a specified mass flow ratio. The method is applicable to two-dimensional inlets at zero or nonzero angle of attack, and to axisymmetric inlets at zero angle of attack. Comparisons with limited available additive drag data indicate fair to good agreement.

Combined AIE/EBE/GMRES approach to incompressible flows. [Adaptive Implicit-Explicit/Grouped Element-by-Element/Generalized Minimum Residuals

NASA Technical Reports Server (NTRS)

Liou, J.; Tezduyar, T. E.

1990-01-01

Adaptive implicit-explicit (AIE), grouped element-by-element (GEBE), and generalized minimum residuals (GMRES) solution techniques for incompressible flows are combined. In this approach, the GEBE and GMRES iteration methods are employed to solve the equation systems resulting from the implicitly treated elements, and therefore no direct solution effort is involved. The benchmarking results demonstrate that this approach can substantially reduce the CPU time and memory requirements in large-scale flow problems. Although the description of the concepts and the numerical demonstration are based on the incompressible flows, the approach presented here is applicable to larger class of problems in computational mechanics.

Does the Current Minimum Validate (or Invalidate) Cycle Prediction Methods?

NASA Technical Reports Server (NTRS)

Hathaway, David H.

2010-01-01

This deep, extended solar minimum and the slow start to Cycle 24 strongly suggest that Cycle 24 will be a small cycle. A wide array of solar cycle prediction techniques have been applied to predicting the amplitude of Cycle 24 with widely different results. Current conditions and new observations indicate that some highly regarded techniques now appear to have doubtful utility. Geomagnetic precursors have been reliable in the past and can be tested with 12 cycles of data. Of the three primary geomagnetic precursors only one (the minimum level of geomagnetic activity) suggests a small cycle. The Sun's polar field strength has also been used to successfully predict the last three cycles. The current weak polar fields are indicative of a small cycle. For the first time, dynamo models have been used to predict the size of a solar cycle but with opposite predictions depending on the model and the data assimilation. However, new measurements of the surface meridional flow indicate that the flow was substantially faster on the approach to Cycle 24 minimum than at Cycle 23 minimum. In both dynamo predictions a faster meridional flow should have given a shorter cycle 23 with stronger polar fields. This suggests that these dynamo models are not yet ready for solar cycle prediction.

40 CFR 89.415 - Fuel flow measurement specifications.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Fuel flow measurement specifications... Emission Test Procedures § 89.415 Fuel flow measurement specifications. The fuel flow rate measurement instrument must have a minimum accuracy of 2 percent of the engine maximum fuel flow rate. The controlling...

The minimum control authority of a system of actuators with applications to Gravity Probe-B

NASA Technical Reports Server (NTRS)

Wiktor, Peter; Debra, Dan

1991-01-01

The forcing capabilities of systems composed of many actuators are analyzed in this paper. Multiactuator systems can generate higher forces in some directions than in others. Techniques are developed to find the force in the weakest direction. This corresponds to the worst-case output and is defined as the 'minimum control authority'. The minimum control authority is a function of three things: the actuator configuration, the actuator controller and the way in which the output of the system is limited. Three output limits are studied: (1) fuel-flow rate, (2) power, and (3) actuator output. The three corresponding actuator controllers are derived. These controllers generate the desired force while minimizing either fuel flow rate, power or actuator output. It is shown that using the optimal controller can substantially increase the minimum control authority. The techniques for calculating the minimum control authority are applied to the Gravity Probe-B spacecraft thruster system. This example shows that the minimum control authority can be used to design the individual actuators, choose actuator configuration, actuator controller, and study redundancy.

Effects of water removal on a Hawaiian stream ecosystem

USGS Publications Warehouse

Kinzie, R. A.; Chong, C.; Devrell, J.; Lindstrom, D.; Wolff, R.

2006-01-01

A 3-year study of Wainiha River on Kaua'i, Hawai'i, was carried out to determine the impact that water removal had on key stream ecosystem parameters and functions. The study area included a diversion dam for a hydroelectric plant that removes water at an elevation of 213 m and returns it to the stream about 6 km downstream at an elevation of 30 m. There were two high-elevation sites, one with undiverted flow and one with reduced flow, and two low-elevation sites, one with reduced flow and one with full flow restored. Monthly samples were taken of instream and riparian invertebrates and plants. When samples from similar elevations were compared, dewatered sites had lower concentrations of benthic photosynthetic pigments than full-flow sites, and benthic ash-free dry mass (AFDM) was higher at the two low-elevation sites regardless of flow. Benthic chlorophyll a (chl a) and AFDM were higher in summer months than in the winter. Benthic invertebrate abundance was highest at the full-flow, low-elevation site and benthic invertebrate biomass was highest at the full-flow, high-elevation site. Season had only marginal effects on abundance and biomass of benthic invertebrates. Diversity of benthic invertebrates was higher at the more-downstream sites. Abundance of drifting invertebrates was highest at the site above the diversion dam and generally higher in winter than in summer months. Biomass of drifting invertebrates was also highest at the above-dam site but there was little seasonal difference. Almost all parameters measured were lowest at the site just downstream of the diversion dam. The biotic parameters responded only weakly to flows that had occurred up to 1 month before the measurements were made. Flow, elevation, and season interact in complex ways that impact ecosystem parameters and functions, but water diversion can override all these environmental factors. ?? 2006 by University of Hawai'i Press All rights reserved.

Using an implicitly-coupled hydrologic and river-operations models to investigate the trade-offs of artificial recharge in agricultural areas

NASA Astrophysics Data System (ADS)

Morway, E. D.; Niswonger, R. G.; Triana, E.

2016-12-01

In irrigated agricultural regions supplied by both surface-water and groundwater, increased reliance on groundwater during sustained drought leads to long-term water table drawdown and subsequent surface-water losses. This, in turn, may threaten the sustainability of the irrigation project. To help offset groundwater resource losses and restore water supply reliability, an alternative management strategy commonly referred to as managed aquifer recharge (MAR) in agricultural regions helps mitigate long-term aquifer drawdown and provides additional water for subsequent withdraw. Sources of MAR in this investigation are limited to late winter runoff in years with above average precipitation (i.e., above average snowpack). However, where winter MAR results in an elevated water table, non-beneficial consumptive use may increase from evapotranspiration in adjacent and down-gradient fallow and naturally vegetated lands. To rigorously explore this trade-off, the recently published MODSIM-MODFLOW model was applied to quantify both the benefits and unintended consequences of MAR. MODSIM-MODFLOW is a generalized modeling tool capable of exploring the effects of altered river operations within an integrated groundwater and surface-water (GW-SW) model. Thus, the MODSIM-MODFLOW model provides a modeling platform capable of simulating MAR in amounts and duration consistent with other senior water rights in the river system (e.g., minimum in-stream flow requirements). Increases in non-beneficial consumptive use resulting from winter MAR are evaluated for a hypothetical model patterned after alluvial aquifers common in arid and semi-arid areas of the western United States. Study results highlight (1) the benefit of an implicitly-coupled river operations and hydrologic modeling tool, (2) the balance between winter MAR and the potential increase in non-beneficial consumptive use, and (3) conditions where MAR may or may not be an appropriate management option, such as the availability of surface-water storage.

Walla Walla River Fish Passage Operations Program, 2004-2005 Annual Report.

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

Bronson, James P.; Duke, Bill B.

2006-02-01

In the late 1990s, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate fish migration conditions in the basin. The migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow requirements, and providing trap and haul efforts when needed. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survivalmore » of migrating adult and juvenile salmonids in the Walla Walla River basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage criteria and passage and trapping facility design and operation. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. During the 2004-2005 project year, there were 590 adult summer steelhead, 31 summer steelhead kelts (Oncorhynchus mykiss), 70 adult bull trout (Salvelinus confluentus); 80 adult and 1 jack spring Chinook (O. tshawytscha) enumerated at the Nursery Bridge Dam fishway video counting window between December 13, 2004, and June 16, 2005. Summer steelhead and spring chinook were observed moving upstream while bull trout were observed moving both upstream and downstream of the facility. In addition, the old ladder trap was operated by ODFW in order to enumerate fish passage. Of the total, 143 adult summer steelhead and 15 summer steelhead kelts were enumerated at the west ladder at Nursery Bridge Dam during the video efforts between February 4 and May 23, 2005. Operation of the Little Walla Walla River juvenile trap for trap and haul purposes was not necessary this year.« less

Iron oxidation kinetics and phosphorus immobilization at the groundwater-surface water interface

NASA Astrophysics Data System (ADS)

van der Grift, Bas; Rozemeijer, Joachim; Griffioen, Jasper; van der Velde, Ype

2014-05-01

Eutrophication of freshwater environments following diffuse nutrient loads is a widely recognized water quality problem in catchments. Fluxes of non-point P sources to surface waters originate from surface runoff and flow from soil water and groundwater into surface water. The availability of P in surface waters is controlled strongly by biogeochemical nutrient cycling processes at the soil-water interface. The mechanisms and rates of the iron oxidation process with associated binding of phosphate during exfiltration of anaerobic Fe(II) bearing groundwater are among the key unknowns in P retention processes in surface waters in delta areas where the shallow groundwater is typically pH-neutral to slightly acid, anoxic, iron-rich. We developed an experimental field set-up to study the dynamics in Fe(II) oxidation and mechanisms of P immobilization at the groundwater-surface water interface in an agricultural experimental catchment of a small lowland river. We physically separated tube drain effluent from groundwater discharge before it entered a ditch in an agricultural field. The exfiltrating groundwater was captured in in-stream reservoirs constructed in the ditch. Through continuous discharge measurements and weekly water quality sampling of groundwater, tube drain water, exfiltrated groundwater, and ditch water, we quantified Fe(II) oxidation kinetics and P immobilization processes across the seasons. This study showed that seasonal changes in climatic conditions affect the Fe(II) oxidation process. In winter time the dissolved iron concentrations in the in-stream reservoirs reached the levels of the anaerobic groundwater. In summer time, the dissolved iron concentrations of the water in the reservoirs are low, indicating that dissolved Fe(II) is completely oxidized prior to inflow into the reservoirs. Higher discharges, lower temperatures and lower pH of the exfiltrated groundwater in winter compared to summer shifts the location of the redox transition zone, with Fe(II) oxidation taking place in the soil surrounding the ditch during summer and in the surface water during winter. The dynamics in Fe(II) oxidation did not affect the dissolved P concentrations. The dissolved P concentrations of the in-stream reservoirs water were an order of magnitude lower than observed in the groundwater and have no seasonal trend. Our data showed preferential binding of P during initial stage of the Fe(II) oxidation process, indicating the formation of Fe(III)-phosphate precipitates. The formation of Fe(III)-phosphates at the groundwater-surface water interface is an important geochemical mechanism in the transformation of dissolved phosphate to particulate phosphate and therefore a major control on the P retention in natural waters that drain anaerobic aquifers.

Flow convergence caused by a salinity minimum in a tidal channel

USGS Publications Warehouse

Warner, John C.; Schoellhamer, David H.; Burau, Jon R.; Schladow, S. Geoffrey

2006-01-01

Residence times of dissolved substances and sedimentation rates in tidal channels are affected by residual (tidally averaged) circulation patterns. One influence on these circulation patterns is the longitudinal density gradient. In most estuaries the longitudinal density gradient typically maintains a constant direction. However, a junction of tidal channels can create a local reversal (change in sign) of the density gradient. This can occur due to a difference in the phase of tidal currents in each channel. In San Francisco Bay, the phasing of the currents at the junction of Mare Island Strait and Carquinez Strait produces a local salinity minimum in Mare Island Strait. At the location of a local salinity minimum the longitudinal density gradient reverses direction. This paper presents four numerical models that were used to investigate the circulation caused by the salinity minimum: (1) A simple one-dimensional (1D) finite difference model demonstrates that a local salinity minimum is advected into Mare Island Strait from the junction with Carquinez Strait during flood tide. (2) A three-dimensional (3D) hydrodynamic finite element model is used to compute the tidally averaged circulation in a channel that contains a salinity minimum (a change in the sign of the longitudinal density gradient) and compares that to a channel that contains a longitudinal density gradient in a constant direction. The tidally averaged circulation produced by the salinity minimum is characterized by converging flow at the bed and diverging flow at the surface, whereas the circulation produced by the constant direction gradient is characterized by converging flow at the bed and downstream surface currents. These velocity fields are used to drive both a particle tracking and a sediment transport model. (3) A particle tracking model demonstrates a 30 percent increase in the residence time of neutrally buoyant particles transported through the salinity minimum, as compared to transport through a constant direction density gradient. (4) A sediment transport model demonstrates increased deposition at the near-bed null point of the salinity minimum, as compared to the constant direction gradient null point. These results are corroborated by historically noted large sedimentation rates and a local maximum of selenium accumulation in clams at the null point in Mare Island Strait.

The Irrigation Effect: How River Regulation Can Promote Some Riparian Vegetation.

PubMed

Gill, Karen M; Goater, Lori A; Braatne, Jeffrey H; Rood, Stewart B

2018-04-01

River regulation impacts riparian ecosystems by altering the hydrogeomorphic conditions that support streamside vegetation. Obligate riparian plants are often negatively impacted since they are ecological specialists with particular instream flow requirements. Conversely, facultative riparian plants are generalists and may be less vulnerable to river regulation, and could benefit from augmented flows that reduce drought stress during hot and dry periods. To consider this 'irrigation effect' we studied the facultative shrub, netleaf hackberry (Celtis reticulata), the predominant riparian plant along the Hells Canyon corridor of the Snake River, Idaho, USA, where dams produce hydropeaking, diurnal flow variation. Inventories of 235 cross-sectional transects revealed that hackberry was uncommon upstream from the reservoirs, sparse along the reservoir with seasonal draw-down and common along two reservoirs with stabilized water levels. Along the Snake River downstream, hackberry occurred in fairly continuous, dense bands along the high water line. In contrast, hackberry was sparsely scattered along the free-flowing Salmon River, where sandbar willow (Salix exigua), an obligate riparian shrub, was abundant. Below the confluence of the Snake and Salmon rivers, the abundance and distribution of hackberry were intermediate between the two upstream reaches. Thus, river regulation apparently benefited hackberry along the Snake River through Hells Canyon, probably due to diurnal pulsing that wets the riparian margin. We predict similar benefits for some other facultative riparian plants along other regulated rivers with hydropeaking during warm and dry intervals. To analyze the ecological impacts of hydropeaking we recommend assessing daily maxima, as well as daily mean river flows.

Management scenarios for the Jordan River salinity crisis

USGS Publications Warehouse

Farber, E.; Vengosh, A.; Gavrieli, I.; Marie, Amarisa; Bullen, T.D.; Mayer, B.; Holtzman, R.; Segal, M.; Shavit, U.

2005-01-01

Recent geochemical and hydrological findings show that the water quality of the base flow of the Lower Jordan River, between the Sea of Galilee and the Dead Sea, is dependent upon the ratio between surface water flow and groundwater discharge. Using water quality data, mass-balance calculations, and actual flow-rate measurements, possible management scenarios for the Lower Jordan River and their potential affects on its salinity are investigated. The predicted scenarios reveal that implementation of some elements of the Israel-Jordan peace treaty will have negative effects on the Jordan River water salinity. It is predicted that removal of sewage effluents dumped into the river (???13 MCM/a) will significantly reduce the river water's flow and increase the relative proportion of the saline groundwater flux into the river. Under this scenario, the Cl content of the river at its southern point (Abdalla Bridge) will rise to almost 7000 mg/L during the summer. In contrast, removal of all the saline water (16.5 MCM/a) that is artificially discharged into the Lower Jordan River will significantly reduce its Cl concentration, to levels of 650-2600 and 3000-3500 mg/L in the northern and southern areas of the Lower Jordan River, respectively. However, because the removal of either the sewage effluents or the saline water will decrease the river's discharge to a level that could potentially cause river desiccation during the summer months, other water sources must be allocated to preserve in-stream flow needs and hence the river's ecosystem. ?? 2005 Elsevier Ltd. All rights reserved.

The Irrigation Effect: How River Regulation Can Promote Some Riparian Vegetation

NASA Astrophysics Data System (ADS)

Gill, Karen M.; Goater, Lori A.; Braatne, Jeffrey H.; Rood, Stewart B.

2018-04-01

River regulation impacts riparian ecosystems by altering the hydrogeomorphic conditions that support streamside vegetation. Obligate riparian plants are often negatively impacted since they are ecological specialists with particular instream flow requirements. Conversely, facultative riparian plants are generalists and may be less vulnerable to river regulation, and could benefit from augmented flows that reduce drought stress during hot and dry periods. To consider this `irrigation effect' we studied the facultative shrub, netleaf hackberry ( Celtis reticulata), the predominant riparian plant along the Hells Canyon corridor of the Snake River, Idaho, USA, where dams produce hydropeaking, diurnal flow variation. Inventories of 235 cross-sectional transects revealed that hackberry was uncommon upstream from the reservoirs, sparse along the reservoir with seasonal draw-down and common along two reservoirs with stabilized water levels. Along the Snake River downstream, hackberry occurred in fairly continuous, dense bands along the high water line. In contrast, hackberry was sparsely scattered along the free-flowing Salmon River, where sandbar willow ( Salix exigua), an obligate riparian shrub, was abundant. Below the confluence of the Snake and Salmon rivers, the abundance and distribution of hackberry were intermediate between the two upstream reaches. Thus, river regulation apparently benefited hackberry along the Snake River through Hells Canyon, probably due to diurnal pulsing that wets the riparian margin. We predict similar benefits for some other facultative riparian plants along other regulated rivers with hydropeaking during warm and dry intervals. To analyze the ecological impacts of hydropeaking we recommend assessing daily maxima, as well as daily mean river flows.

Ictalurid populations in relation to the presence of a main-stem reservoir in a midwestern warmwater stream with emphasis on the threatened Neosho madtom

USGS Publications Warehouse

Wildhaber, M.L.; Tabor, V.M.; Whitaker, J.E.; Allert, A.L.; Mulhern, D.W.; Lamberson, Peter J.; Powell, K.L.

2000-01-01

Ictalurid populations, including those of the Neosho madtom Noturus placidus, have been monitored in the Neosho River basin since the U.S. Fish and Wildlife Service listed the Neosho madtom as threatened in 1991. The Neosho madtom presently occurs only in the Neosho River basin, whose hydrologic regime, physical habitat, and water quality have been altered by the construction and operation of reservoirs. Our objective was to assess changes in ictalurid densities, habitat, water quality, and hydrology in relation to the presence of a main-stem reservoir in the Neosho River basin. Study sites were characterized using habitat quality as measured by substrate size, water quality as measured by standard physicochemical measures, and indicators of hydrologic alteration (IHA) as calculated from stream gauge information from the U.S. Geological Survey. Site estimates of ictalurid densities were collected by the U.S. Fish and Wildlife Service annually from 1991 to 1998, with the exception of 1993. Water quality and habitat measurements documented reduced turbidity and altered substrate composition in the Neosho River basin below John Redmond Dam. The effects of the dam on flow were indicated by changes in the short- and long-term minimum and maximum flows. Positive correlations between observed Neosho madtom densities and increases in minimum flow suggest that increased minimum flows could be used to enhance Neosho madtom populations. Positive correlations between Neosho madtom densities and increased flows in the winter and spring months as well as the date of the 1-d annual minimum flow indicate the potential importance of the timing of increased flows to Neosho madtoms. Because of the positive relationships that we found between the densities of Neosho madtoms and those of channel catfish Ictalurus punctatus, stonecats Noturus flavus, and other catfishes, alterations in flow that benefit Neosho madtom populations will probably benefit other members of the benthic fish community of the Neosho River.

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

Smith, Brennan T; Jager, Yetta; March, Patrick

Reservoir releases are typically operated to maximize the efficiency of hydropower production and the value of hydropower produced. In practice, ecological considerations are limited to those required by law. We first describe reservoir optimization methods that include mandated constraints on environmental and other water uses. Next, we describe research to formulate and solve reservoir optimization problems involving both energy and environmental water needs as objectives. Evaluating ecological objectives is a challenge in these problems for several reasons. First, it is difficult to predict how biological populations will respond to flow release patterns. This problem can be circumvented by using ecologicalmore » models. Second, most optimization methods require complex ecological responses to flow to be quantified by a single metric, preferably a currency that can also represent hydropower benefits. Ecological valuation of instream flows can make optimization methods that require a single currency for the effects of flow on energy and river ecology possible. Third, holistic reservoir optimization problems are unlikely to be structured such that simple solution methods can be used, necessitating the use of flexible numerical methods. One strong advantage of optimal control is the ability to plan for the effects of climate change. We present ideas for developing holistic methods to the point where they can be used for real-time operation of reservoirs. We suggest that developing ecologically sound optimization tools should be a priority for hydropower in light of the increasing value placed on sustaining both the ecological and energy benefits of riverine ecosystems long into the future.« less

Scale-dependent genetic structure of the Idaho giant salamander (Dicamptodon aterrimus) in stream networks.

PubMed

Mullen, Lindy B; Arthur Woods, H; Schwartz, Michael K; Sepulveda, Adam J; Lowe, Winsor H

2010-03-01

The network architecture of streams and rivers constrains evolutionary, demographic and ecological processes of freshwater organisms. This consistent architecture also makes stream networks useful for testing general models of population genetic structure and the scaling of gene flow. We examined genetic structure and gene flow in the facultatively paedomorphic Idaho giant salamander, Dicamptodon aterrimus, in stream networks of Idaho and Montana, USA. We used microsatellite data to test population structure models by (i) examining hierarchical partitioning of genetic variation in stream networks; and (ii) testing for genetic isolation by distance along stream corridors vs. overland pathways. Replicated sampling of streams within catchments within three river basins revealed that hierarchical scale had strong effects on genetic structure and gene flow. amova identified significant structure at all hierarchical scales (among streams, among catchments, among basins), but divergence among catchments had the greatest structural influence. Isolation by distance was detected within catchments, and in-stream distance was a strong predictor of genetic divergence. Patterns of genetic divergence suggest that differentiation among streams within catchments was driven by limited migration, consistent with a stream hierarchy model of population structure. However, there was no evidence of migration among catchments within basins, or among basins, indicating that gene flow only counters the effects of genetic drift at smaller scales (within rather than among catchments). These results show the strong influence of stream networks on population structure and genetic divergence of a salamander, with contrasting effects at different hierarchical scales.

Siphon flows in isolated magnetic flux tubes. V - Radiative flows with variable ionization

NASA Technical Reports Server (NTRS)

Montesinos, Benjamin; Thomas, John H.

1993-01-01

Steady siphon flows in arched isolated magnetic flux tubes in the solar atmosphere are calculated here including radiative transfer between the flux tube and its surrounding and variable ionization of the flowing gas. It is shown that the behavior of a siphon flow is strongly determined by the degree of radiative coupling between the flux tube and its surroundings in the superadiabatic layer just below the solar surface. Critical siphon flows with adiabatic tube shocks in the downstream leg are calculated, illustrating the radiative relaxation of the temperature jump downstream of the shock. For flows in arched flux tubes reaching up to the temperature minimum, where the opacity is low, the gas inside the flux tube is much cooler than the surrounding atmosphere at the top of the arch. It is suggested that gas cooled by siphon flows contribute to the cool component of the solar atmosphere at the height of the temperature minimum implied by observations of the infrared CO bands at 4.6 and 2.3 microns.

Lagrangian sampling of wastewater treatment plant effluent in Boulder Creek, Colorado, and Fourmile Creek, Iowa, during the summer of 2003 and spring of 2005--Hydrological and chemical data

USGS Publications Warehouse

Barber, Larry B.; Keefe, Steffanie H.; Kolpin, Dana W.; Schnoebelen, Douglas J.; Flynn, Jennifer L.; Brown, Gregory K.; Furlong, Edward T.; Glassmeyer, Susan T.; Gray, James L.; Meyer, Michael T.; Sandstrom, Mark W.; Taylor, Howard E.; Zaugg, Steven D.

2011-01-01

This report presents methods and data for a Lagrangian sampling investigation into chemical loading and in-stream attenuation of inorganic and organic contaminants in two wastewater treatment-plant effluent-dominated streams: Boulder Creek, Colorado, and Fourmile Creek, Iowa. Water-quality sampling was timed to coincide with low-flow conditions when dilution of the wastewater treatment-plant effluent by stream water was at a minimum. Sample-collection times corresponded to estimated travel times (based on tracer tests) to allow the same "parcel" of water to reach downstream sampling locations. The water-quality data are linked directly to stream discharge using flow- and depth-integrated composite sampling protocols. A range of chemical analyses was made for nutrients, carbon, major elements, trace elements, biological components, acidic and neutral organic wastewater compounds, antibiotic compounds, pharmaceutical compounds, steroid and steroidal-hormone compounds, and pesticide compounds. Physical measurements were made for field conditions, stream discharge, and time-of-travel studies. Two Lagrangian water samplings were conducted in each stream, one in the summer of 2003 and the other in the spring of 2005. Water samples were collected from five sites in Boulder Creek: upstream from the wastewater treatment plant, the treatment-plant effluent, and three downstream sites. Fourmile Creek had seven sampling sites: upstream from the wastewater treatment plant, the treatment-plant effluent, four downstream sites, and a tributary. At each site, stream discharge was measured, and equal width-integrated composite water samples were collected and split for subsequent chemical, physical, and biological analyses. During the summer of 2003 sampling, Boulder Creek downstream from the wastewater treatment plant consisted of 36 percent effluent, and Fourmile Creek downstream from the respective wastewater treatment plant was 81 percent effluent. During the spring of 2005 samplings, Boulder Creek downstream from the wastewater treatment plant was 40 percent effluent, and Fourmile Creek downstream from that wastewater treatment plant was 28 percent effluent. At each site, 300 individual constituents were determined to characterize the water. Most of the inorganic constituents were detected in all of the stream and treatment-plant effluent samples, whereas detection of synthetic organic compounds was more limited and contaminants typically occurred only in wastewater treatment-plant effluents and at downstream sites. Concentrations ranged from nanograms per liter to milligrams per liter.

Flow of ground water through fractured carbonate rocks in the Prairie du Chien-Jordan Aquifer, southeastern Minnesota

USGS Publications Warehouse

Ruhl, J.F.

1989-01-01

Contamination of groundwater from point and nonpoint sources (such as landfills, feedlots, agricultural chemicals applied to fields, and septic systems) is a recognized problem in the karst area of southeastern Minnesota. The US Geological Survey, in cooperation with the Minnesota Department of Natural Resources and the Legislative Commission on Minnesota Resources, Began a study in October 1987 to improve the understanding of local groundwater flow through karst terrain in southeastern Minnesota. The objectives of the study are to: (1) describe the orientations of systematic rock fractures and solution channels of the Prairie du Chien Group of Ordovician-age carbonate rocks in southeastern Minnesota, and, if possible, to define the principal and minor axes of these orientations; and (2) evaluate the effect of fractures and solution channels in the Prairie du Chien Group on the local flow of groundwater. Groundwater in the Upper Carbonate aquifer regionally flows toward the periphery of the aquifer and locally flows into streams and bedrock valleys. The hydraulic gradient in this aquifer generally is greatest near areas of groundwater seepage to streams. Regional groundwater flow in the Prairie du Chien-Jordan aquifer generally is to the south and east in much of Fillmore and Houston Counties and in the southern parts of Olmsted and Winona Counties. Groundwater seepage to selected streams was evaluated by current-meter measurements of downstream gains or losses of streamflow and by an experimental approach based on radon activity in streams. The activity of radon in groundwater ranges from two to four orders of magnitude greater than the activity in surface water; therefore, groundwater seepage to streams generally increases the in-stream radon activity.

Two-dimensional hydrodynamic modeling to quantify effects of peak-flow management on channel morphology and salmon-spawning habitat in the Cedar River, Washington

USGS Publications Warehouse

Czuba, Christiana; Czuba, Jonathan A.; Gendaszek, Andrew S.; Magirl, Christopher S.

2010-01-01

The Cedar River in Washington State originates on the western slope of the Cascade Range and provides the City of Seattle with most of its drinking water, while also supporting a productive salmon habitat. Water-resource managers require detailed information on how best to manage high-flow releases from Chester Morse Lake, a large reservoir on the Cedar River, during periods of heavy precipitation to minimize flooding, while mitigating negative effects on fish populations. Instream flow-management practices include provisions for adaptive management to promote and maintain healthy aquatic habitat in the river system. The current study is designed to understand the linkages between peak flow characteristics, geomorphic processes, riverine habitat, and biological responses. Specifically, two-dimensional hydrodynamic modeling is used to simulate and quantify the effects of the peak-flow magnitude, duration, and frequency on the channel morphology and salmon-spawning habitat. Two study reaches, representative of the typical geomorphic and ecologic characteristics of the Cedar River, were selected for the modeling. Detailed bathymetric data, collected with a real-time kinematic global positioning system and an acoustic Doppler current profiler, were combined with a LiDAR-derived digital elevation model in the overbank area to develop a computational mesh. The model is used to simulate water velocity, benthic shear stress, flood inundation, and morphologic changes in the gravel-bedded river under the current and alternative flood-release strategies. Simulations of morphologic change and salmon-redd scour by floods of differing magnitude and duration enable water-resource managers to incorporate model simulation results into adaptive management of peak flows in the Cedar River. PDF version of a presentation on hydrodynamic modelling in the Cedar River in Washington state. Presented at the American Geophysical Union Fall Meeting 2010.

Characterizing mercury concentrations and fluxes in a Coastal Plain watershed: Insights from dynamic modeling and data

USGS Publications Warehouse

Golden, H.E.; Knightes, C.D.; Conrads, P.A.; Davis, G.M.; Feaster, T.D.; Journey, C.A.; Benedict, S.T.; Brigham, M.E.; Bradley, P.M.

2012-01-01

Mercury (Hg) is one of the leading water quality concerns in surface waters of the United States. Although watershed-scale Hg cycling research has increased in the past two decades, advances in modeling watershed Hg processes in diverse physiographic regions, spatial scales, and land cover types are needed. The goal of this study was to assess Hg cycling in a Coastal Plain system using concentrations and fluxes estimated by multiple watershed-scale models with distinct mathematical frameworks reflecting different system dynamics. We simulated total mercury (HgT, the sum of filtered and particulate forms) concentrations and fluxes from a Coastal Plain watershed (McTier Creek) using three watershed Hg models and an empirical load model. Model output was compared with observed in-stream HgT. We found that shallow subsurface flow is a potentially important transport mechanism of particulate HgT during periods when connectivity between the uplands and surface waters is maximized. Other processes (e.g., stream bank erosion, sediment re-suspension) may increase particulate HgT in the water column. Simulations and data suggest that variable source area (VSA) flow and lack of rainfall interactions with surface soil horizons result in increased dissolved HgT concentrations unrelated to DOC mobilization following precipitation events. Although flushing of DOC-HgT complexes from surface soils can also occur during this period, DOC-complexed HgT becomes more important during base flow conditions. TOPLOAD simulations highlight saturated subsurface flow as a primary driver of daily HgT loadings, but shallow subsurface flow is important for HgT loads during high-flow events. Results suggest limited seasonal trends in HgT dynamics.

Characterizing mercury concentrations and fluxes in a Coastal Plain watershed: Insights from dynamic modeling and data

USGS Publications Warehouse

Golden, H.E.; Knightes, C.D.; Conrads, P.A.; Davis, G.M.; Feaster, T.D.; Journey, C.A.; Benedict, S.T.; Brigham, M.E.; Bradley, P.M.

2012-01-01

Mercury (Hg) is one of the leading water quality concerns in surface waters of the United States. Although watershed-scale Hg cycling research has increased in the past two decades, advances in modeling watershed Hg processes in diverse physiographic regions, spatial scales, and land cover types are needed. The goal of this study was to assess Hg cycling in a Coastal Plain system using concentrations and fluxes estimated by multiple watershed-scale models with distinct mathematical frameworks reflecting different system dynamics. We simulated total mercury (Hg T, the sum of filtered and particulate forms) concentrations and fluxes from a Coastal Plain watershed (McTier Creek) using three watershed Hg models and an empirical load model. Model output was compared with observed in-stream Hg T. We found that shallow subsurface flow is a potentially important transport mechanism of particulate Hg T during periods when connectivity between the uplands and surface waters is maximized. Other processes (e.g., stream bank erosion, sediment re-suspension) may increase particulate Hg T in the water column. Simulations and data suggest that variable source area (VSA) flow and lack of rainfall interactions with surface soil horizons result in increased dissolved Hg T concentrations unrelated to DOC mobilization following precipitation events. Although flushing of DOC-Hg T complexes from surface soils can also occur during this period, DOC-complexed Hg T becomes more important during base flow conditions. TOPLOAD simulations highlight saturated subsurface flow as a primary driver of daily Hg T loadings, but shallow subsurface flow is important for Hg T loads during high-flow events. Results suggest limited seasonal trends in Hg T dynamics. Copyright 2012 by the American Geophysical Union.

Preliminary assessment of vertical stability and gravel transport along the Umpqua River, southwestern Oregon

USGS Publications Warehouse

O'Connor, Jim E.; Wallick, J. Rose; Sobieszczyk, Steven; Cannon, Charles; Anderson, Scott W.

2009-01-01

This report addresses physical channel issues related to instream gravel mining on the Umpqua River and its two primary tributaries, the North and South Umpqua Rivers. This analysis constitutes a “Phase I” investigation, as designated by an interagency team cochaired by the U.S. Army Corps of Engineers, Portland District, and the Oregon Department of State Lands to address instream gravel mining issues across Oregon. Phase I analyses rely primarily on existing datasets and cursory analysis to determine the vertical stability of a channel to ascertain whether a particular river channel is aggrading, degrading, or at equilibrium. Additionally, a Phase I analysis identifies other critical issues or questions pertinent to physical channel conditions that may be related to instream gravel mining activities.This analysis can support agency permitting decisions as well as possibly indicating the need for additional studies. This specific analysis focuses on the mainstem Umpqua River from the Pacific Ocean at River Mile (RM) 0 to the confluence of the North and South Umpqua Rivers (at RM 111.8), as well as the lower 29 mi of the North Umpqua River and the lower 80 mi of the South Umpqua River (fig. 1). It is within these reaches where mining of gravel bars for aggregate has been most prevalent.

Modeling In-stream Tidal Energy Extraction and Its Potential Environmental Impacts

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

Yang, Zhaoqing; Wang, Taiping; Copping, Andrea

In recent years, there has been growing interest in harnessing in-stream tidal energy in response to concerns of increasing energy demand and to mitigate climate change impacts. While many studies have been conducted to assess and map tidal energy resources, efforts for quantifying the associated potential environmental impacts have been limited. This paper presents the development of a tidal turbine module within a three-dimensional unstructured-grid coastal ocean model and its application for assessing the potential environmental impacts associated with tidal energy extraction. The model is used to investigate in-stream tidal energy extraction and associated impacts on estuarine hydrodynamic and biologicalmore » processes in a tidally dominant estuary. A series of numerical experiments with varying numbers and configurations of turbines installed in an idealized estuary were carried out to assess the changes in the hydrodynamics and biological processes due to tidal energy extraction. Model results indicated that a large number of turbines are required to extract the maximum tidal energy and cause significant reduction of the volume flux. Preliminary model results also indicate that extraction of tidal energy increases vertical mixing and decreases flushing rate in a stratified estuary. The tidal turbine model was applied to simulate tidal energy extraction in Puget Sound, a large fjord-like estuary in the Pacific Northwest coast.« less

Multi-scale assessment of human-induced changes to ...

EPA Pesticide Factsheets

Context: Land use change and forest degradation have myriad effects on tropical ecosystems. Yet their consequences for low-order streams remain very poorly understood, including in the world´s largest freshwater basin, the Amazon.Objectives: Determine the degree to which physical and chemical characteristics of the instream habitat of low-order Amazonian streams change in response to past local- and catchment-level anthropogenic disturbances. Methods: To do so, we collected field instream habitat (i.e., physical habitat and water quality) and landscape data from 99 stream sites in two eastern Brazilian Amazon regions. We used random forest regression trees to assess the relative importance of different predictor variables in determining changes in instream habitat response variables. Adaptations the USEPA’s National Aquatic Resource Survey (NARS) designs, field methods, and approaches for assessing ecological condition have been applied in state and basin stream surveys throughout the U.S., and also in countries outside of the U.S. These applications not only provide valuable tests of the NARS approaches, but generate new understandings of natural and anthropogenic controls on biota and physical habitat in streams. Results from applications in Brazil, for example, not only aid interpretation of the condition of Brazilian streams, but also refine approaches for interpreting aquatic resource surveys in the U.S. and elsewhere. In this article, the authors des

The chemistry of iron, aluminum, and dissolved organic material in three acidic, metal-enriched, mountain streams, as controlled by watershed and in-stream processes

USGS Publications Warehouse

McKnight, Diane M.; Bencala, Kenneth E.

1990-01-01

Several studies were conducted in three acidic, metal-enriched, mountain streams, and the results are discussed together in this paper to provide a synthesis of watershed and in-stream processes controlling Fe, Al, and DOC (dissolved organic carbon) concentrations. One of the streams, the Snake River, is naturally acidic; the other two, Peru Creek and St. Kevin Gulch, receive acid mine drainage. Analysis of stream water chemistry data for the acidic headwaters of the Snake River shows that some trace metal solutes (Al, Mn, Zn) are correlated with major ions, indicating that watershed processes control their concentrations. Once in the stream, biogeochemical processes can control transport if they occur over time scales comparable to those for hydrologic transport. Examples of the following in-stream reactions are presented: (1) photoreduction and dissolution of hydrous iron oxides in response to an experimental decrease in stream pH, (2) precipitation of Al at three stream confluences, and (3) sorption of dissolved organic material by hydrous iron and aluminum oxides in a stream confluence. The extent of these reactions is evaluated using conservative tracers and a transport model that includes storage in the substream zone.

Predicting non-stationary algal dynamics following changes in hydrometeorological conditions using data assimilation techniques

NASA Astrophysics Data System (ADS)

Kim, S.; Seo, D. J.

2017-12-01

When water temperature (TW) increases due to changes in hydrometeorological conditions, the overall ecological conditions change in the aquatic system. The changes can be harmful to human health and potentially fatal to fish habitat. Therefore, it is important to assess the impacts of thermal disturbances on in-stream processes of water quality variables and be able to predict effectiveness of possible actions that may be taken for water quality protection. For skillful prediction of in-stream water quality processes, it is necessary for the watershed water quality models to be able to reflect such changes. Most of the currently available models, however, assume static parameters for the biophysiochemical processes and hence are not able to capture nonstationaries seen in water quality observations. In this work, we assess the performance of the Hydrological Simulation Program-Fortran (HSPF) in predicting algal dynamics following TW increase. The study area is located in the Republic of Korea where waterway change due to weir construction and drought concurrently occurred around 2012. In this work we use data assimilation (DA) techniques to update model parameters as well as the initial condition of selected state variables for in-stream processes relevant to algal growth. For assessment of model performance and characterization of temporal variability, various goodness-of-fit measures and wavelet analysis are used.

40 CFR 63.1257 - Test methods and compliance procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

...)(2), or 63.1256(h)(2)(i)(C) with a minimum residence time of 0.5 seconds and a minimum temperature of... temperature of the organic HAP, must consider the vent stream flow rate, and must establish the design minimum and average temperature in the combustion zone and the combustion zone residence time. (B) For a...

40 CFR 63.1257 - Test methods and compliance procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

...)(2), or 63.1256(h)(2)(i)(C) with a minimum residence time of 0.5 seconds and a minimum temperature of... temperature of the organic HAP, must consider the vent stream flow rate, and must establish the design minimum and average temperature in the combustion zone and the combustion zone residence time. (B) For a...

40 CFR 63.1257 - Test methods and compliance procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

...)(2), or 63.1256(h)(2)(i)(C) with a minimum residence time of 0.5 seconds and a minimum temperature of... temperature of the organic HAP, must consider the vent stream flow rate, and must establish the design minimum and average temperature in the combustion zone and the combustion zone residence time. (B) For a...

Ferromagnetic core valve gives rapid action on minimum energy

NASA Technical Reports Server (NTRS)

Larson, A. V.; Tinkham, J. P.

1967-01-01

Miniature solenoid valve controls propellant flow during tests on a coaxial plasma accelerator. It uses an advanced ferromagnetic core design which meets all the rapid-acting requirements with a minimum of input energy.

Fish population and habitat analysis in Buck Creek, Washington, prior to recolonization by anadromous salmonids after the removal of Condit Dam

USGS Publications Warehouse

Allen, M. Brady; Burkhardt, Jeanette; Munz, Carrie; Connolly, Patrick J.

2012-01-01

We assessed the physical and biotic conditions in the part of Buck Creek, Washington, potentially accessible to anadromous fishes. This creek is a major tributary to the White Salmon River upstream of Condit Dam, which was breached in October 2011. Habitat and fish populations were characterized in four stream reaches. Reach breaks were based on stream gradient, water withdrawals, and fish barriers. Buck Creek generally was confined, with a single straight channel and low sinuosity. Boulders and cobble were the dominant stream substrate, with limited gravel available for spawning. Large-cobble riffles were 83 percent of the available fish habitat. Pools, comprising 15 percent of the surface area, mostly were formed by bedrock with little instream cover and low complexity. Instream wood averaged 6—10 pieces per 100 meters, 80 percent of which was less than 50 centimeters in diameter. Water temperature in Buck Creek rarely exceeded 16 degrees Celsius and did so for only 1 day at river kilometer (rkm) 3 and 11 days at rkm 0.2 in late July and early August 2009. The maximum temperature recorded was 17.2 degrees Celsius at rkm 0.2 on August 2, 2009. Minimum summer discharge in Buck Creek was 3.3 cubic feet per second downstream of an irrigation diversion (rkm 3.1) and 7.7 cubic feet per second at its confluence with the White Salmon River. Rainbow trout (Oncorhynchus mykiss) was the dominant fish species in all reaches. The abundance of age-1 or older rainbow trout was similar between reaches. However, in 2009 and 2010, the greatest abundance of age-0 rainbow trout (8 fish per meter) was in the most downstream reach. These analyses in Buck Creek are important for understanding the factors that may limit fish abundance and productivity, and they will help identify and prioritize potential restoration actions. The data collected constitute baseline information of pre-dam removal conditions that will allow assessment of changes in fish populations now that Condit Dam has been removed and anadromous fish have an opportunity to recolonize Buck Creek.

sedFlow - a tool for simulating fractional bedload transport and longitudinal profile evolution in mountain streams

NASA Astrophysics Data System (ADS)

Heimann, F. U. M.; Rickenmann, D.; Turowski, J. M.; Kirchner, J. W.

2015-01-01

Especially in mountainous environments, the prediction of sediment dynamics is important for managing natural hazards, assessing in-stream habitats and understanding geomorphic evolution. We present the new modelling tool {sedFlow} for simulating fractional bedload transport dynamics in mountain streams. sedFlow is a one-dimensional model that aims to realistically reproduce the total transport volumes and overall morphodynamic changes resulting from sediment transport events such as major floods. The model is intended for temporal scales from the individual event (several hours to few days) up to longer-term evolution of stream channels (several years). The envisaged spatial scale covers complete catchments at a spatial discretisation of several tens of metres to a few hundreds of metres. sedFlow can deal with the effects of streambeds that slope uphill in a downstream direction and uses recently proposed and tested approaches for quantifying macro-roughness effects in steep channels. sedFlow offers different options for bedload transport equations, flow-resistance relationships and other elements which can be selected to fit the current application in a particular catchment. Local grain-size distributions are dynamically adjusted according to the transport dynamics of each grain-size fraction. sedFlow features fast calculations and straightforward pre- and postprocessing of simulation data. The high simulation speed allows for simulations of several years, which can be used, e.g., to assess the long-term impact of river engineering works or climate change effects. In combination with the straightforward pre- and postprocessing, the fast calculations facilitate efficient workflows for the simulation of individual flood events, because the modeller gets the immediate results as direct feedback to the selected parameter inputs. The model is provided together with its complete source code free of charge under the terms of the GNU General Public License (GPL) (www.wsl.ch/sedFlow). Examples of the application of sedFlow are given in a companion article by Heimann et al. (2015).

Two-station comparison of peak flows to improve flood-frequency estimates for seven streamflow-gaging stations in the Salmon and Clearwater River Basins, Central Idaho

USGS Publications Warehouse

Berenbrock, Charles

2003-01-01

Improved flood-frequency estimates for short-term (10 or fewer years of record) streamflow-gaging stations were needed to support instream flow studies by the U.S. Forest Service, which are focused on quantifying water rights necessary to maintain or restore productive fish habitat. Because peak-flow data for short-term gaging stations can be biased by having been collected during an unusually wet, dry, or otherwise unrepresentative period of record, the data may not represent the full range of potential floods at a site. To test whether peak-flow estimates for short-term gaging stations could be improved, the two-station comparison method was used to adjust the logarithmic mean and logarithmic standard deviation of peak flows for seven short-term gaging stations in the Salmon and Clearwater River Basins, central Idaho. Correlation coefficients determined from regression of peak flows for paired short-term and long-term (more than 10 years of record) gaging stations over a concurrent period of record indicated that the mean and standard deviation of peak flows for all short-term gaging stations would be improved. Flood-frequency estimates for seven short-term gaging stations were determined using the adjusted mean and standard deviation. The original (unadjusted) flood-frequency estimates for three of the seven short-term gaging stations differed from the adjusted estimates by less than 10 percent, probably because the data were collected during periods representing the full range of peak flows. Unadjusted flood-frequency estimates for four short-term gaging stations differed from the adjusted estimates by more than 10 percent; unadjusted estimates for Little Slate Creek and Salmon River near Obsidian differed from adjusted estimates by nearly 30 percent. These large differences probably are attributable to unrepresentative periods of peak-flow data collection.

Minimum-dissipation scalar transport model for large-eddy simulation of turbulent flows

NASA Astrophysics Data System (ADS)

Abkar, Mahdi; Bae, Hyun J.; Moin, Parviz

2016-08-01

Minimum-dissipation models are a simple alternative to the Smagorinsky-type approaches to parametrize the subfilter turbulent fluxes in large-eddy simulation. A recently derived model of this type for subfilter stress tensor is the anisotropic minimum-dissipation (AMD) model [Rozema et al., Phys. Fluids 27, 085107 (2015), 10.1063/1.4928700], which has many desirable properties. It is more cost effective than the dynamic Smagorinsky model, it appropriately switches off in laminar and transitional flows, and it is consistent with the exact subfilter stress tensor on both isotropic and anisotropic grids. In this study, an extension of this approach to modeling the subfilter scalar flux is proposed. The performance of the AMD model is tested in the simulation of a high-Reynolds-number rough-wall boundary-layer flow with a constant and uniform surface scalar flux. The simulation results obtained from the AMD model show good agreement with well-established empirical correlations and theoretical predictions of the resolved flow statistics. In particular, the AMD model is capable of accurately predicting the expected surface-layer similarity profiles and power spectra for both velocity and scalar concentration.

Geostatistical modeling of the spatial distribution of sediment oxygen demand within a Coastal Plain blackwater watershed

PubMed Central

Todd, M. Jason; Lowrance, R. Richard; Goovaerts, Pierre; Vellidis, George; Pringle, Catherine M.

2010-01-01

Blackwater streams are found throughout the Coastal Plain of the southeastern United States and are characterized by a series of instream floodplain swamps that play a critical role in determining the water quality of these systems. Within the state of Georgia, many of these streams are listed in violation of the state’s dissolved oxygen (DO) standard. Previous work has shown that sediment oxygen demand (SOD) is elevated in instream floodplain swamps and due to these areas of intense oxygen demand, these locations play a major role in determining the oxygen balance of the watershed as a whole. This work also showed SOD rates to be positively correlated with the concentration of total organic carbon. This study builds on previous work by using geostatistics and Sequential Gaussian Simulation to investigate the patchiness and distribution of total organic carbon (TOC) at the reach scale. This was achieved by interpolating TOC observations and simulated SOD rates based on a linear regression. Additionally, this study identifies areas within the stream system prone to high SOD at representative 3rd and 5th order locations. Results show that SOD was spatially correlated with the differences in distribution of TOC at both locations and that these differences in distribution are likely a result of the differing hydrologic regime and watershed position. Mapping of floodplain soils at the watershed scale shows that areas of organic sediment are widespread and become more prevalent in higher order streams. DO dynamics within blackwater systems are a complicated mix of natural and anthropogenic influences, but this paper illustrates the importance of instream swamps in enhancing SOD at the watershed scale. Moreover, our study illustrates the influence of instream swamps on oxygen demand while providing support that many of these systems are naturally low in DO. PMID:20938491

Chemical and isotopic evidence of nitrogen transformation in the Mississippi River, 1997-98

USGS Publications Warehouse

Battaglin, William A.; Kendall, Carol; Chang, Cecily C.Y.; Silva, Steven R.; Campbell, D.H.

2001-01-01

Nitrate (NO3) and other nutrients discharged by the Mississippi River are suspected of causing a zone of depleted dissolved oxygen (hypoxic zone) in the Gulf of Mexico each summer. The hypoxic zone may have an adverse affect on aquatic life and commercial fisheries. The amount of NO3 delivered by the Mississippi River to the Gulf of Mexico is well documented, but the relative contributions of different sources of NO3, and the magnitude of subsequent in-stream transformations of NO3, are not well understood. Forty-two water samples collected in 1997 and 1998 at eight stations located either on the Mississippi River or its major tributaries were analysed for NO3, total nitrogen (N), atrazine, chloride concentrations and NO3 stable isotopes (δ15N and δ18O). These data are used to assess the magnitude and nature of in-stream N transformation and to determine if the δ15N and δ18O of NO3 provide information about NO3 sources and transformation processes in a large river system (drainage area 2 900 000 km2) that would otherwise be unavailable using concentration and discharge data alone. Results from 42 samples indicate that the δ15N and δ18O ratios between sites on the Mississippi River and its tributaries are somewhat distinctive, and vary with season and discharge rate. Of particular interest are two nearly Lagrangian sample sets, in which samples from the Mississippi River at St Francisville, LA, are compared with samples collected from the Ohio River at Grand Chain, II, and the Mississippi River at Thebes, IL. In both Lagrangian sets, mass-balance calculations indicate only a small amount of in-stream N loss. The stable isotope data from the samples suggest that in-stream N assimilation and not denitrification accounts for most of the N loss in the lower Mississippi River during the spring and early summer months.

Anthropogenic land uses elevate metal levels in stream water in an urbanizing watershed.

PubMed

Yu, Shen; Wu, Qian; Li, Qingliang; Gao, Jinbo; Lin, Qiaoying; Ma, Jun; Xu, Qiufang; Wu, Shengchun

2014-08-01

Land use/cover change is a dominant factor affecting surface water quality in rapidly developing areas of Asia. In this study we examined relationships between land use and instream metal loadings in a rapidly developing mixed land use watershed in southeastern China. Five developing subwatersheds and one forested reference site (head water) were instrumented with timing- and rainfall-triggered autosampler and instream loadings of anthropogenic metals (Cu, Zn, Pb, Cr, Cd, and Mn) were monitored from March 2012 to December 2013. Farm land and urban land were positively, and forest and green land were negatively associated with metal loadings (except Cr) in stream water. All developing sites had higher loadings than the reference head water site. Assessed by Chinese surface water quality standard (GB3830-2002), instream loadings of Cu and Zn occasionally exceeded the Class I thresholds at monitoring points within farmland dominated subwatersheds while Mn loadings were greater than the limit for drinking water sources at all monitoring points. Farm land use highly and positively contributed to statistical models of instream loadings of Cu, Zn, Cd, and Mn while urban land use was the dominant contributor to models of Pb and Cd loadings. Rainfall played a crucial role in metal loadings in stream water as a direct source (there were significant levels of Cu and Zn in rain water) and as a driver of watershed processes (loadings were higher in wet years and seasons). Urbanization effects on metal loadings in this watershed are likely to change rapidly with development in future years. Further monitoring to characterize these changes is clearly warranted and should help to develop plans to avoid conflicts between economic development and water quality degradation in this watershed and in watersheds throughout rapidly developing areas of Asia. Copyright © 2014 Elsevier B.V. All rights reserved.

Modeling nutrient in-stream processes at the watershed scale using Nutrient Spiralling metrics

NASA Astrophysics Data System (ADS)

Marcé, R.; Armengol, J.

2009-01-01

One of the fundamental problems of using large-scale biogeochemical models is the uncertainty involved in aggregating the components of fine-scale deterministic models in watershed applications, and in extrapolating the results of field-scale measurements to larger spatial scales. Although spatial or temporal lumping may reduce the problem, information obtained during fine-scale research may not apply to lumped categories. Thus, the use of knowledge gained through fine-scale studies to predict coarse-scale phenomena is not straightforward. In this study, we used the nutrient uptake metrics defined in the Nutrient Spiralling concept to formulate the equations governing total phosphorus in-stream fate in a watershed-scale biogeochemical model. The rationale of this approach relies on the fact that the working unit for the nutrient in-stream processes of most watershed-scale models is the reach, the same unit used in field research based on the Nutrient Spiralling concept. Automatic calibration of the model using data from the study watershed confirmed that the Nutrient Spiralling formulation is a convenient simplification of the biogeochemical transformations involved in total phosphorus in-stream fate. Following calibration, the model was used as a heuristic tool in two ways. First, we compared the Nutrient Spiralling metrics obtained during calibration with results obtained during field-based research in the study watershed. The simulated and measured metrics were similar, suggesting that information collected at the reach scale during research based on the Nutrient Spiralling concept can be directly incorporated into models, without the problems associated with upscaling results from fine-scale studies. Second, we used results from our model to examine some patterns observed in several reports on Nutrient Spiralling metrics measured in impaired streams. Although these two exercises involve circular reasoning and, consequently, cannot validate any hypothesis, this is a powerful example of how models can work as heuristic tools to compare hypotheses and stimulate research in ecology.

Habitat suitability of the Carolina madtom, an imperiled, endemic stream fish

USGS Publications Warehouse

Midway, S.R.; Kwak, Thomas J.; Aday, D.D.

2010-01-01

The Carolina madtom Noturus furiosus is an imperiled stream ictalurid that is endemic to the Tar and Neuse River basins in North Carolina. The Carolina madtom is listed as a threatened species by the state of North Carolina, and whereas recent distribution surveys have found that the Tar River basin population occupies a range similar to its historical range, the Neuse River basin population has shown recent significant decline. Quantification of habitat requirements and availability is critical for effective management and subsequent survival of the species. We investigated six reaches (three in each basin) to (1) quantify Carolina madtom microhabitat use, availability, and suitability; (2) compare suitable microhabitat availability between the two basins; and (3) examine use of an instream artificial cover unit. Carolina madtoms were located and their habitat was quantified at four of the six survey reaches. They most frequently occupied shallow to moderate depths of swift moving water over a sand substrate and used cobble for cover. Univariate and principal components analyses both showed that Carolina madtom use of instream habitat was selective (i.e., nonrandom). Interbasin comparisons suggested that suitable microhabitats were more prevalent in the impacted Neuse River basin than in the Tar River basin. We suggest that other physical or biotic effects may be responsible for the decline in the Neuse River basin population. We designed instream artificial cover units that were occupied by Carolina madtoms (25% of the time) and occasionally by other organisms. Carolina madtom abundance among all areas treated with the artificial cover unit was statistically higher than that in the control areas, demonstrating use of artificial cover when available. Microhabitat characteristics of occupied artificial cover units closely resembled those of natural instream microhabitat used by Carolina madtoms; these units present an option for conservation and restoration if increased management is deemed necessary. Results from our study provide habitat suitability criteria and artificial cover information that can inform management and conservation of the Carolina madtom.

Performance of transonic fan stage with weight flow per unit annulus area of 178 kilograms per second per square meter (6.5(lb/sec)/(sq ft))

NASA Technical Reports Server (NTRS)

Moore, R. D.; Urasek, D. C.; Kovich, G.

1973-01-01

The overall and blade-element performances are presented over the stable flow operating range from 50 to 100 percent of design speed. Stage peak efficiency of 0.834 was obtained at a weight flow of 26.4 kg/sec (58.3 lb/sec) and a pressure ratio of 1.581. The stall margin for the stage was 7.5 percent based on weight flow and pressure ratio at stall and peak efficiency conditions. The rotor minimum losses were approximately equal to design except in the blade vibration damper region. Stator minimum losses were less than design except in the tip and damper regions.

Estimation of the effects of land use and groundwater withdrawals on streamflow for the Pomperaug River, Connecticut

USGS Publications Warehouse

Bjerklie, David M.; Starn, J. Jeffrey; Tamayo, Claudia

2010-01-01

A precipitation runoff model for the Pomperaug River watershed, Connecticut was developed to address issues of concern including the effect of development on streamflow and groundwater recharge, and the implications of water withdrawals on streamflow. The model was parameterized using a strategy that requires a minimum of calibration and optimization by establishing basic relations between the parameter value and physical characteristics of individual hydrologic response units (HRUs) that comprise the model. The strategy was devised so that the information needed can be obtained from Geographic Information System and other general databases for Connecticut. Simulation of groundwater recharge enabled evaluation of the temporal and spatial mapping of recharge variation across the watershed and the spatial effects of changes in land cover on base flow and surface runoff. The modeling indicated that over the course of a year, groundwater provides between 60 and 70 percent of flow in the Pomperaug River; the remainder is generated by more rapid flow through the shallow subsurface and runoff from impermeable surfaces and saturated ground. Groundwater is recharged primarily during periods of low evapotranspiration in the winter, spring, and fall. The largest amount of recharge occurs in the spring in response to snowmelt. During floods, the Weekeepeemee and Nonnewaug Rivers (tributaries that form the Pomperaug River) respond rapidly with little flood peak attenuation due to flood-plain storage. In the Pomperaug River, flood-plain storage is more important in attenuating floods; abandoned quarry ponds (O&G ponds) adjacent to the river provide substantial flood storage above specific river stages when flow from the river spills over the banks and fills the ponds. Discharge from the ponds also helps to sustain low flows in the Pomperaug River. Similarly, releases from the Bronson-Lockwood reservoir sustain flow in the Nonnewaug River and tend to offset the effect of groundwater withdrawals from a well field adjacent to the river during periods of natural low flow. The model indicated that under the current zoning, future development could reduce low flows by as much as 10 percent at the 99 percent exceedance level (99 percent of flows are greater than or equal to this flow), but would not substantially increase the highest flows. Simulation of projected and hypothetical development in the watershed shows, depending on how stormwater is managed, that between 10 and 20 percent effective impervious area in an HRU results in streamflow becoming dominated by the surface-runoff component. This shift from a groundwater-dominated system would likely result in substantial changes in water quality and instream habitat characteristics of the river. Base flow to streams in the Pomperaug River watershed is reduced by both increased impervious surface and increased groundwater withdrawals. For the watershed as a whole, increasing groundwater withdrawals have the potential for causing greater overall reductions in flow compared to increased development and impervious surfaces. Additionally, on the basis of groundwater-modeling simulations, the projected increase in development across the watershed and, to a lesser extent the increase in groundwater withdrawals, will increase the number of local losing reaches experiencing dry conditions and the duration of these dry periods. The location of the losing reaches tends to be in areas near the transition from the uplands to the valley bottoms that are filled with coarse glacial stratified deposits. The simulated increase in the duration and extent of localized dry stream reaches is most sensitive to local increase in impervious surface. Conversion of land from forest or developed land cover to pasture or agricultural land increases groundwater recharge and discharge to streams, while at the same time increasing overall streamflow (the opposite effect as increased impervious surface). These resu

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.

Stationary zonal flows during the formation of the edge transport barrier in the JET tokamak

DOE PAGES

Hillesheim, J. C.; Meyer, H.; Maggi, C. F.; ...

2016-02-10

In this study, high spatial resolution Doppler backscattering measurements in JET have enabled new insights into the development of the edge E r. We observe fine-scale spatial structures in the edge E r well with a wave number k rρi ≈ 0.4-0.8, consistent with stationary zonal flows, the characteristics of which vary with density. The zonal flow amplitude and wavelength both decrease with local collisionality, such that the zonal flow E x B shear increases. Above the minimum of the L-H transition power threshold dependence on density, the zonal flows are present during L mode and disappear following the H-modemore » transition, while below the minimum they are reduced below measurable amplitude during L mode, before the L-H transition.« less

Longitudinal differences in habitat complexity and fish assemblage structure of a great plains river

USGS Publications Warehouse

Eitzmann, J.L.; Paukert, C.P.

2010-01-01

We investigated the spatial variation in the Kansas River (USA) fish assemblage to determine how fish community structure changes with habitat complexity in a large river. Fishes were collected at ten sites throughout the Kansas River for assessing assemblage structure in summer 2007. Aerial imagery indicated riparian land use within 200 m from the river edge was dominated by agriculture in the upper river reaches (>35) and tended to increase in urban land use in the lower reaches (>58). Instream habitat complexity (number of braided channels, islands) also decreased with increased urban area (<25). Canonical correspondence analysis indicated that species that prefer high-velocity flows and sandy substrate (e.g., blue sucker Cycleptus elongatus and shovelnose sturgeon Scaphirhynchus platorynchus) were associated with the upper river reaches. Abundance of omnivorous and planktivorous fish species were also higher in the lower river. The presence of fluvial dependent and fluvial specialist species was associated with sites with higher water flows, more sand bars, and log jams. Our results suggest that conserving intolerant, native species in the Kansas River may require maintaining suitable habitat for these species and restoration of impacted areas of the river.

Dating base flow in streams using dissolved gases and diurnal temperature changes

USGS Publications Warehouse

Sanford, Ward E.; Casile, Gerolamo C.; Haase, Karl B.

2015-01-01

A method is presented for using dissolved CFCs or SF6 to estimate the apparent age of stream base flow by indirectly estimating the mean concentration of the tracer in the inflowing groundwater. The mean value is estimated simultaneously with the mean residence times of the gas and water in the stream by sampling the stream for one or both age tracers, along with dissolved nitrogen and argon at a single location over a period of approximately 12–14 h. The data are fitted to an equation representing the temporal in-stream gas exchange as it responds to the diurnal temperature fluctuation. The efficacy of the method is demonstrated by collecting and analyzing samples at six different stream locations across parts of northern Virginia, USA. The studied streams drain watersheds with areas of between 2 and 122 km2 during periods when the diurnal stream temperature ranged between 2 and 5°C. The method has the advantage of estimating the mean groundwater residence time of discharge from the watershed to the stream without the need for the collection of groundwater infiltrating to streambeds or local groundwater sampled from shallow observation wells near the stream.

Mathematical models frame environmental dispute [Review of the article Useless arithmetic: Ten points to ponder when using mathematical models in environmental decision making

USGS Publications Warehouse

Lamb, Berton Lee; Burkardt, Nina

2008-01-01

When Linda Pilkey- Jarvis and Orrin Pilkey state in their article, "Useless Arithmetic," that "mathematical models are simplified, generalized representations of a process or system," they probably do not mean to imply that these models are simple. Rather, the models are simpler than nature and that is the heart of the problem with predictive models. We have had a long professional association with the developers and users of one of these simplifications of nature in the form of a mathematical model known as Physical Habitat Simulation (PHABSIM), which is part of the Instream Flow Incremental Methodology (IFIM). The IFIM is a suite of techniques, including PHABSIM, that allows the analyst to incorporate hydrology , hydraulics, habitat, water quality, stream temperature, and other variables into a tradeoff analysis that decision makers can use to design a flow regime to meet management objectives (Stalnaker et al. 1995). Although we are not the developers of the IFIM, we have worked with those who did design it, and we have tried to understand how the IFIM and PHABSIM are actually used in decision making (King, Burkardt, and Clark 2006; Lamb 1989).

Physical modeling of river spanning rock structures: Evaluating interstitial flow, local hydraulics, downstream scour development, and structure stability

USGS Publications Warehouse

Collins, K.L.; Thornton, C.I.; Mefford, B.; Holmquist-Johnson, C. L.

2009-01-01

Rock weir and ramp structures uniquely serve a necessary role in river management: to meet water deliveries in an ecologically sound manner. Uses include functioning as low head diversion dams, permitting fish passage, creating habitat diversity, and stabilizing stream banks and profiles. Existing information on design and performance of in-stream rock structures does not provide the guidance necessary to implement repeatable and sustainable construction and retrofit techniques. As widespread use of rock structures increases, the need for reliable design methods with a broad range of applicability at individual sites grows as well. Rigorous laboratory testing programs were implemented at the U.S. Bureau of Reclamation (Reclamation) and at Colorado State University (CSU) as part of a multifaceted research project focused on expanding the current knowledge base and developing design methods to improve the success rate of river spanning rock structures in meeting project goals. Physical modeling at Reclamation is being used to measure, predict, and reduce interstitial flow through rock ramps. CSU is using physical testing to quantify and predict scour development downstream of rock weirs and its impact on the stability of rock structures. ?? 2009 ASCE.

Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2007-2008 Report of Research.

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

Achord, Stephen; Sandford, Benjamin P.; Hockersmith, Eric E.

2009-05-26

This report provides results from an ongoing project to monitor the migration behavior and survival of wild juvenile spring/summer Chinook salmon in the Snake River Basin. Data reported is from detections of PIT tagged fish during late summer 2007 through mid-2008. Fish were tagged in summer 2007 by the National Marine Fisheries Service (NMFS) in Idaho and by the Oregon Department of Fish and Wildlife (ODFW) in Oregon. Our analyses include migration behavior and estimated survival of fish at instream PIT-tag monitors and arrival timing and estimated survival to Lower Granite Dam. Principal results from tagging and interrogation during 2007-2008more » are listed below: (1) In July and August 2007, we PIT tagged and released 7,390 wild Chinook salmon parr in 12 Idaho streams or sample areas. (2) Overall observed mortality from collection, handling, tagging, and after a 24-hour holding period was 1.4%. (3) Of the 2,524 Chinook salmon parr PIT tagged and released in Valley Creek in summer 2007, 218 (8.6%) were detected at two instream PIT-tag monitoring systems in lower Valley Creek from late summer 2007 to the following spring 2008. Of these, 71.6% were detected in late summer/fall, 11.9% in winter, and 16.5% in spring. Estimated parr-to-smolt survival to Lower Granite Dam was 15.5% for the late summer/fall group, 48.0% for the winter group, and 58.5% for the spring group. Based on detections at downstream dams, the overall efficiency of VC1 (upper) or VC2 (lower) Valley Creek monitors for detecting these fish was 21.1%. Using this VC1 or VC2 efficiency, an estimated 40.8% of all summer-tagged parr survived to move out of Valley Creek, and their estimated survival from that point to Lower Granite Dam was 26.5%. Overall estimated parr-to-smolt survival for all summer-tagged parr from this stream at the dam was 12.1%. Development and improvement of instream PIT-tag monitoring systems continued throughout 2007 and 2008. (4) Testing of PIT-tag antennas in lower Big Creek during 2007-2008 showed these antennas (and anchoring method) are not adequate to withstand high spring flows in this drainage. Future plans involve removing these antennas before high spring flows. (5) At Little Goose Dam in 2008, length and/or weight were taken on 505 recaptured fish from 12 Idaho stream populations. Fish had grown an average of 40.1 mm in length and 10.6 g in weight over an average of 288 d. Their mean condition factor declined from 1.25 at release (parr) to 1.05 at recapture (smolt). (6) Mean release lengths for detected fish were significantly larger than for fish not detected the following spring and summer (P < 0.0001). (7) Fish that migrated through Lower Granite Dam in April and May were significantly larger at release than fish that migrated after May (P < 0.0001) (only 12 fish migrated after May). (8) In 2008, peak detections at Lower Granite Dam of parr tagged during summer 2007 (from the 12 stream populations in Idaho and 4 streams in Oregon) occurred during moderate flows of 87.5 kcfs on 7 May and high flows of 197.3 kcfs on 20 May. The 10th, 50th, and 90th percentile passage occurred on 30 April, 11 May, and 23 May, respectively. (9) In 2007-2008, estimated parr-to-smolt survival to Lower Granite Dam for Idaho and Oregon streams (combined) averaged 19.4% (range 6.2-38.4% depending on stream of origin). In Idaho streams the estimated parr-to-smolt survival averaged 21.0%. This survival was the second highest since 1993 for Idaho streams. Relative parr densities were lower in 2007 (2.4 parr/100 m{sup 2}) than in all previous years since 2000. In 2008, we observed low-to-moderate flows prior to mid-May and relatively cold weather conditions throughout the spring migration season. These conditions moved half of the fish through Lower Granite Dam prior to mid-May; then high flows moved 50 to 90% of the fish through the dam in only 12 days. Clearly, complex interrelationships of several factors drive the annual migrational timing of the stocks.« less

Bounds of cavitation inception in a creeping flow between eccentric cylinders rotating with a small minimum gap

NASA Astrophysics Data System (ADS)

Monakhov, A. A.; Chernyavski, V. M.; Shtemler, Yu.

2013-09-01

Bounds of cavitation inception are experimentally determined in a creeping flow between eccentric cylinders, the inner one being static and the outer rotating at a constant angular velocity, Ω. The geometric configuration is additionally specified by a small minimum gap between cylinders, H, as compared with the radii of the inner and outer cylinders. For some values H and Ω, cavitation bubbles are observed, which are collected on the surface of the inner cylinder and equally distributed over the line parallel to its axis near the downstream minimum gap position. Cavitation occurs for the parameters {H,Ω} within a region bounded on the right by the cavitation inception curve that passes through the plane origin and cannot exceed the asymptotic threshold value of the minimum gap, Ha, in whose vicinity cavitation may occur at H < Ha only for high angular rotation velocities.

Supersonic minimum length nozzle design for dense gases

NASA Technical Reports Server (NTRS)

Aldo, Andrew C.; Argrow, Brian M.

1993-01-01

Recently, dense gases have been investigated for many engineering applications such as for turbomachinery and wind tunnels. Supersonic nozzle design for these gases is complicated by their nonclassical behavior in the transonic flow regime. In this paper a method of characteristics (MOC) is developed for two-dimensional (planar) and, primarily, axisymmetric flow of a van der Waals gas. Using a straight aortic line assumption, a centered expansion is used to generate an inviscid wall contour of minimum length. The van der Waals results are compared to previous perfect gas results to show the real gas effects on the flow properties and inviscid wall contours.

Multimodal pressure-flow method to assess dynamics of cerebral autoregulation in stroke and hypertension.

PubMed

Novak, Vera; Yang, Albert C C; Lepicovsky, Lukas; Goldberger, Ary L; Lipsitz, Lewis A; Peng, Chung-Kang

2004-10-25

This study evaluated the effects of stroke on regulation of cerebral blood flow in response to fluctuations in systemic blood pressure (BP). The autoregulatory dynamics are difficult to assess because of the nonstationarity and nonlinearity of the component signals. We studied 15 normotensive, 20 hypertensive and 15 minor stroke subjects (48.0 +/- 1.3 years). BP and blood flow velocities (BFV) from middle cerebral arteries (MCA) were measured during the Valsalva maneuver (VM) using transcranial Doppler ultrasound. A new technique, multimodal pressure-flow analysis (MMPF), was implemented to analyze these short, nonstationary signals. MMPF analysis decomposes complex BP and BFV signals into multiple empirical modes, representing their instantaneous frequency-amplitude modulation. The empirical mode corresponding to the VM BP profile was used to construct the continuous phase diagram and to identify the minimum and maximum values from the residual BP (BPR) and BFV (BFVR) signals. The BP-BFV phase shift was calculated as the difference between the phase corresponding to the BPR and BFVR minimum (maximum) values. BP-BFV phase shifts were significantly different between groups. In the normotensive group, the BFVR minimum and maximum preceded the BPR minimum and maximum, respectively, leading to large positive values of BP-BFV shifts. In the stroke and hypertensive groups, the resulting BP-BFV phase shift was significantly smaller compared to the normotensive group. A standard autoregulation index did not differentiate the groups. The MMPF method enables evaluation of autoregulatory dynamics based on instantaneous BP-BFV phase analysis. Regulation of BP-BFV dynamics is altered with hypertension and after stroke, rendering blood flow dependent on blood pressure.

The science and practice of environmental flows and the role of hydrogeologists

USGS Publications Warehouse

Sophocleous, M.

2007-01-01

Conflicts between ecosystems and human needs for fresh water are increasing. The purpose of this paper is to raise awareness in the hydrogeologic community of environmental flows (EFs) and to address the major challenges involved in their protection. Ground water is a key component of EFs, and therefore hydrogeologists are called upon to get involved in the ongoing debates about maintaining healthy riverine ecosystems. Promising opportunities for achieving EFs in both underallocated and overallocated basins as well as new methods for protecting fresh water ecosystems developed in different countries are outlined. EF protection measures include private water trusts, "upside-down instream flow water rights," the "public trust" doctrine, and water markets, among other measures. A number of knowledge gaps are identified, to which hydrogeologists could contribute, such as our rudimentary knowledge about ground water-dependent ecosystems, aspects of stream-aquifer interactions, and the impacts of land-use changes. The values that society places on the different uses of water ultimately determine where the water is allocated. EF requirements can be legitimately recognized and addressed by basing the environmental needs of hydrologic systems on robust science, focusing on increasing the productivity of water use, engaging society in understanding the benefits and costs of decisions that affect ecosystems, and taking advantage of various opportunities for achieving EF goals. ?? 2007 National Ground Water Association.

A one-dimensional, steady-state, dissolved-oxygen model and waste-load assimilation study for South Fork, Wildcat Creek, Clinton County, Indiana

USGS Publications Warehouse

Crawford, Charles G.; Wilber, William G.; Peters, James G.

1979-01-01

The Indiana State Board of Health is developing a State water-quality management plan that includes establishing limits for wastewater effluents discharged into Indiana streams. A digital model calibrated to conditions in South Fork Wildcat Creek was used to predict alternatives for future waste loadings that would be compatible with Indiana stream water-quality standards defined for two critical hydrologic conditions, summer and winter low flows. Natural streamflow during the 7-day, 10-year low flow is zero, so no benefit from dilution is provided. The Indiana State Board of Health 's projected ammonia-nitrogen concentration for the Frankfort wastewater-treatment facility will violate the instream total ammonia-nitrogen standard of 2.5 mg/l and 4.0 mg/l during summer and winter low flows, respectively. The model indicates that nitrification and algal respiration were significant factors affecting the dissolved-oxygen dynamics of South Fork Wildcat Creek during two water-quality surveys. Stream water quality during the two water-quality surveys was degraded by the discharge of wastewater receiving only primary treatment. Benthic deposits resulting from this wastewater discharge seem to exert a considerable oxygen demand. The discharge of partially treated wastewater should be eliminated when a new wastewater-treatment facility becomes operational in mid-1979. Therefore, benthic-oxygen demand due to benthic deposits should become negligible at that time.

Fish habitat characterization and quantification using lidar and conventional topographic information in river survey

NASA Astrophysics Data System (ADS)

Marchamalo, Miguel; Bejarano, María-Dolores; García de Jalón, Diego; Martínez Marín, Rubén

2007-10-01

This study presents the application of LIDAR data to the evaluation and quantification of fluvial habitat in river systems, coupling remote sensing techniques with hydrological modeling and ecohydraulics. Fish habitat studies depend on the quality and continuity of the input topographic data. Conventional fish habitat studies are limited by the feasibility of field survey in time and budget. This limitation results in differences between the level of river management and the level of models. In order to facilitate upscaling processes from modeling to management units, meso-scale methods were developed (Maddock & Bird, 1996; Parasiewicz, 2001). LIDAR data of regulated River Cinca (Ebro Basin, Spain) were acquired in the low flow season, maximizing the recorded instream area. DTM meshes obtained from LIDAR were used as the input for hydraulic simulation for a range of flows using GUAD2D software. Velocity and depth outputs were combined with gradient data to produce maps reflecting the availability of each mesohabitat unit type for each modeled flow. Fish habitat was then estimated and quantified according to the preferences of main target species as brown trout (Salmo trutta). LIDAR data combined with hydraulic modeling allowed the analysis of fluvial habitat in long fluvial segments which would be time-consuming with traditional survey. LIDAR habitat assessment at mesoscale level avoids the problems of time efficiency and upscaling and is a recommended approach for large river basin management.

Bridging Scales: A Model-Based Assessment of the Technical Tidal-Stream Energy Resource off Massachusetts, USA

NASA Astrophysics Data System (ADS)

Cowles, G. W.; Hakim, A.; Churchill, J. H.

2016-02-01

Tidal in-stream energy conversion (TISEC) facilities provide a highly predictable and dependable source of energy. Given the economic and social incentives to migrate towards renewable energy sources there has been tremendous interest in the technology. Key challenges to the design process stem from the wide range of problem scales extending from device to array. In the present approach we apply a multi-model approach to bridge the scales of interest and select optimal device geometries to estimate the technical resource for several realistic sites in the coastal waters of Massachusetts, USA. The approach links two computational models. To establish flow conditions at site scales ( 10m), a barotropic setup of the unstructured grid ocean model FVCOM is employed. The model is validated using shipboard and fixed ADCP as well as pressure data. For device scale, the structured multiblock flow solver SUmb is selected. A large ensemble of simulations of 2D cross-flow tidal turbines is used to construct a surrogate design model. The surrogate model is then queried using velocity profiles extracted from the tidal model to determine the optimal geometry for the conditions at each site. After device selection, the annual technical yield of the array is evaluated with FVCOM using a linear momentum actuator disk approach to model the turbines. Results for several key Massachusetts sites including comparison with theoretical approaches will be presented.

42 CFR 84.207 - Bench tests; gas and vapor tests; minimum requirements; general.

Code of Federal Regulations, 2013 CFR

2013-10-01

....) Flowrate (l.p.m.) Number of tests Penetration 1 (p.p.m.) Minimum life 2 (min.) Ammonia As received NH3 1000... minimum life shall be one-half that shown for each type of gas or vapor. Where a respirator is designed... at predetermined concentrations and rates of flow, and that has means for determining the test life...

42 CFR 84.207 - Bench tests; gas and vapor tests; minimum requirements; general.

Code of Federal Regulations, 2014 CFR

2014-10-01

....) Flowrate (l.p.m.) Number of tests Penetration 1 (p.p.m.) Minimum life 2 (min.) Ammonia As received NH3 1000... minimum life shall be one-half that shown for each type of gas or vapor. Where a respirator is designed... at predetermined concentrations and rates of flow, and that has means for determining the test life...

42 CFR 84.207 - Bench tests; gas and vapor tests; minimum requirements; general.

Code of Federal Regulations, 2012 CFR

2012-10-01

....) Flowrate (l.p.m.) Number of tests Penetration 1 (p.p.m.) Minimum life 2 (min.) Ammonia As received NH3 1000... minimum life shall be one-half that shown for each type of gas or vapor. Where a respirator is designed... at predetermined concentrations and rates of flow, and that has means for determining the test life...

Investigations on the Influence of the In-Stream Pylon and Strut on the Performance of a Scramjet Combustor

PubMed Central

Liu, Weidong; Sun, Mingbo

2014-01-01

The influence of the in-stream pylon and strut on the performance of scramjet combustor was experimentally and numerically investigated. The experiments were conducted with a direct-connect supersonic model combustor equipped with multiple cavities. The entrance parameter of combustor corresponds to scramjet flight Mach number 4.0 with a total temperature of 947 K. The research results show that, compared with the scramjet combustor without pylon and strut, the wall pressure and the thrust of the scramjet increase due to the improvement of mixing and combustion effect due to the pylon and strut. The total pressure loss caused by the strut is considerable whereas pylon influence is slight. PMID:25254234

Low-flow profiles of the Tennessee River tributaries in Georgia

USGS Publications Warehouse

Carter, R.F.; Hopkins, E.H.; Perlman, H.A.

1988-01-01

Low flow information is provided for use in an evaluation of the capacity of streams to permit withdrawals or to accept waste loads without exceeding the limits of State water quality standards. The purpose of this report is to present the results of a compilation of available low flow data in the form of tables and ' 7Q10 flow profiles ' (minimum average flow for 7 consecutive days with a 10-yr recurrence interval) (7Q10 flow plotted against distance along a stream channel) for all stream reaches of the Tennessee River tributaries where sufficient data of acceptable accuracy are available. Drainage area profiles are included for all stream basins larger than 5 sq mi, except for those in a few remote areas. This report is the fifth in a series of reports that will cover all stream basins north of the Fall Line in Georgia. It includes the parts of the Tennessee River basin in Georgia. Flow records were not adjusted for diversions or other factors that cause measured flows to represent other than natural flow conditions. The 7-day minimum flow profile was omitted for stream reaches where natural flow was known to be altered significantly. (Lantz-PTT)

Ground-water/surface-water relations along Honey Creek, Washtenaw County, Michigan, 2003

USGS Publications Warehouse

Healy, Denis F.

2005-01-01

The U.S. Geological Survey (USGS), in cooperation with the city of Ann Arbor, Mich., investigated the ground-water/ surface-water relations along the lower reaches of Honey Creek, Washtenaw County, Mich., and an unnamed tributary to Honey Creek (the discharge tributary) from June through October 2003. Streamflow in these reaches was artificially high during a naturally low-flow period due to an anthropogenic discharge. Ground-water/surface-water relations were examined by seepage runs (series of streamflow measurements for the computation of streams gains or losses) and measurements of the difference in head between the stream surface and shallow aquifer. Specific conductance and water-temperature measurements were used as ancillary data to help identify gaining and losing reaches. Three seepage runs and four runs in which hydraulic-head differences between the stream and shallow aquifer were measured (piezometer runs) were made during periods of base flow. Streamflow measurements were made at 18 sites for the seepage runs. Instream piezometers were installed at 16 sites and bank piezometers were installed at 2 sites. Two deeper instream piezometers were installed at site 13 on September 4, 2003 to collect additional data on the ground-water/surface-water relations at that site. The seepage runs indicate that the main stem of Honey Creek and the discharge tributary in the study area are overall gaining reaches. The seepage runs also indicate that smaller reaches of Honey Creek and the discharge tributary may be losing reaches and that this relation may change over time with changing hydraulic conditions. The piezometer-run measurements support the seepage-run results on the main stem, whereas piezometer-run measurements both support and conflict with seepage-run measurements on the discharge tributary. Seepage runs give an average for the reach, whereas piezometer head-difference measurements are for a specific area around the piezometer. Data that may appear to be conflicting actually may be showing that within a gaining reach there are localized areas that lose streamflow. The overall gain in streamflow along with specific measurements of head differences, specific conductance, and water temperature indicate that ground water is discharging to Honey Creek and the discharge tributary. Although reaches and areas that lose streamflow have been identified, data collected during this study cannot confirm or disprove that the loss is to the regional ground-water system.

Development and evaluation of the microbial fate and transport module for the Agricultural Policy/Environmental eXtender (APEX) model

NASA Astrophysics Data System (ADS)

Hong, Eun-Mi; Park, Yongeun; Muirhead, Richard; Pachepsky, Yakov

2017-04-01

Pathogenic microorganisms in recreational and irrigation waters remain the subject of concern. Water quality models are used to estimate microbial quality of water sources, to evaluate microbial contamination-related risks, to guide the microbial water quality monitoring, and to evaluate the effect of agricultural management on the microbial water quality. The Agricultural Policy/Environmental eXtender (APEX) is the watershed-scale water quality model that includes highly detailed representation of agricultural management. The APEX currently does not have microbial fate and transport simulation capabilities. The objective of this work was to develop the first APEX microbial fate and transport module that could use the APEX conceptual model of manure removal together with recently introduced conceptualizations of the in-stream microbial fate and transport. The module utilizes manure erosion rates found in the APEX. The total number of removed bacteria was set to the concentrations of bacteria in soil-manure mixing layer and eroded manure amount. Bacteria survival in soil-manure mixing layer was simulated with the two-stage survival model. Individual survival patterns were simulated for each manure application date. Simulated in-stream microbial fate and transport processes included the reach-scale passive release of bacteria with resuspended bottom sediment during high flow events, the transport of bacteria from bottom sediment due to the hyporheic exchange during low flow periods, the deposition with settling sediment, and the two-stage survival. Default parameter values were available from recently published databases. The APEX model with the newly developed microbial fate and transport module was applied to simulate seven years of monitoring data for the Toenepi watershed in New Zealand. The stream network of the watershed ran through grazing lands with the daily bovine waste deposition. Based on calibration and testing results, the APEX with the microbe module reproduced well the monitored pattern of E. coli concentrations at the watershed outlet. The APEX with the microbial fate and transport module will be utilized for predicting microbial quality of water under various agricultural practices (grazing, cropping, and manure application), evaluating monitoring protocols, and supporting the selection of management practices based on regulations that rely on fecal indicator bacteria concentrations. Future development should include modeling contributions of wildlife, manure weathering, and weather effects on manure-borne microorganism survival and release.

Is in-stream macrophyte growth predictable and what are its impacts on channel-averaged flow characteristics?

NASA Astrophysics Data System (ADS)

Jordan, David N.; Thomas, Robert E.; Keevil, Gareth M.; Parsons, Daniel R.; Hardy, Richard J.

2016-04-01

Understanding how the growth of aquatic vegetation impacts stage-discharge coupling is vital for river management planning. This study presents an annual record of monthly spatial distribution surveys of the in-stream macrophyte Ranunculus penicillatus coupled with channel form and flow velocity measurements, within a 50 m-long reach of a gravel-bed river. Whereas stage has varied by up to 0.4 m, there has been little change in channel form over the monitoring period (ongoing since 23/07/2014). Macrophyte growth continued from the start of the monitoring period until October 2014 when mean patch area was 6.74 m2, and then decreased throughout a decay phase until January 2015 when mean patch area was 1.12 m2. There was a 75.2% loss of macrophyte surface area between October 2014 and January 2015. The largest patches that remained in January 2015 continued to decay until February. Conversely, new macrophyte patches also began to recolonize the channel during this time. To our knowledge, this is the first evidence of a transition period during which aquatic vegetation is in both decay and recolonization phases simultaneously. In total 69% of patches present in January exhibited regrowth without further decay to form a base for recolonization. Therefore, the spatial distribution of macrophyte patches could be determined to be somewhat persistent. Despite this, due to several different growth factors, there are recognisable differences in both macrophyte patch shape and distribution when comparing data from July 2014 and July 2015, emphasising the unpredictability of macrophyte growth. The decay period of the Ranunculus p. coincided with seasonal high discharges in this catchment. Discharge remained high from January until March 2015, but then began to decrease, reflecting annual peaks in historical records for the study area. Large discharge variations were not matched by a large stage range. Displacement of water by vegetation growth maintained the stage height when discharge rates fell. Greater understanding of the relationship between discharge and growth is therefore necessary for determining appropriate reference conditions for river management planning. Results from this multi-season study will provide the base for future work in quantifying temporal changes to patch shape in addition to quantifying the organisation of patches within the channel.

Numerical Modeling of Surface and Volumetric Cooling using Optimal T- and Y-shaped Flow Channels

NASA Astrophysics Data System (ADS)

Kosaraju, Srinivas

2017-11-01

The layout of T- and V-shaped flow channel networks on a surface can be optimized for minimum pressure drop and pumping power. The results of the optimization are in the form of geometric parameters such as length and diameter ratios of the stem and branch sections. While these flow channels are optimized for minimum pressure drop, they can also be used for surface and volumetric cooling applications such as heat exchangers, air conditioning and electronics cooling. In this paper, an effort has been made to study the heat transfer characteristics of multiple T- and Y-shaped flow channel configurations using numerical simulations. All configurations are subjected to same input parameters and heat generation constraints. Comparisons are made with similar results published in literature.

Low-Current, Xenon Orificed Hollow Cathode Performance for In-Space Applications

NASA Technical Reports Server (NTRS)

Domonkos, Matthew T.; Patterson, Michael J.; Gallimore, Alec D.

2002-01-01

An experimental investigation of the operating characteristics of 3.2-mm diameter orificed hollow cathodes was conducted to examine low current and low flow rate operation. Cathode power was minimized with an orifice aspect ratio of approximately one and the use of an enclosed keeper. Cathode flow rate requirements were proportional to orifice diameter and the inverse of the orifice length. The minimum power consumption in diode mode was 10-W, and the minimum mass flow rate required for spot-mode emission was approximately 0.08-mg/s. Cathode temperature profiles were obtained using an imaging radiometer and conduction was found to be the dominant heat transfer mechanism from the cathode tube. Orifice plate temperatures were found to be weakly dependent upon the flow rate and strongly dependent upon the current.

Intercooler cooling-air weight flow and pressure drop for minimum drag loss

NASA Technical Reports Server (NTRS)

Reuter, J George; Valerino, Michael F

1944-01-01

An analysis has been made of the drag losses in airplane flight of cross-flow plate and tubular intercoolers to determine the cooling-air weight flow and pressure drop that give a minimum drag loss for any given cooling effectiveness and, thus, a maximum power-plant net gain due to charge-air cooling. The drag losses considered in this analysis are those due to (1) the extra drag imposed on the airplane by the weight of the intercooler, its duct, and its supports and (2) the drag sustained by the cooling air in flowing through the intercooler and its duct. The investigation covers a range of conditions of altitude, airspeed, lift-drag ratio, supercharger-pressure ratio, and supercharger adiabatic efficiency. The optimum values of cooling air pressure drop and weight flow ratio are tabulated. Curves are presented to illustrate the results of the analysis.

Impact of blood flow on diffusion coefficients of the human kidney: a time-resolved ECG-triggered diffusion-tensor imaging (DTI) study at 3T.

PubMed

Heusch, Philipp; Wittsack, Hans-Jörg; Kröpil, Patric; Blondin, Dirk; Quentin, Michael; Klasen, Janina; Pentang, Gael; Antoch, Gerald; Lanzman, Rotem S

2013-01-01

To evaluate the impact of renal blood flow on apparent diffusion coefficients (ADC) and fractional anisotropy (FA) using time-resolved electrocardiogram (ECG)-triggered diffusion-tensor imaging (DTI) of the human kidneys. DTI was performed in eight healthy volunteers (mean age 29.1 ± 3.2) using a single slice coronal echoplanar imaging (EPI) sequence (3 b-values: 0, 50, and 300 s/mm(2)) at the timepoint of minimum (20 msec after R wave) and maximum renal blood flow (200 msec after R wave) at 3T. Following 2D motion correction, region of interest (ROI)-based analysis of cortical and medullary ADC- and FA-values was performed. ADC-values of the renal cortex at maximum blood flow (2.6 ± 0.19 × 10(-3) mm(2)/s) were significantly higher than at minimum blood flow (2.2 ± 0.11 × 10(-3) mm(2)/s) (P < 0.001), while medullary ADC-values did not differ significantly (maximum blood flow: 2.2 ± 0.18 × 10(-3) mm(2)/s; minimum blood flow: 2.15 ± 0.14 × 10(-3) mm(2)/s). FA-values of the renal medulla were significantly greater at maximal blood (0.53 ± 0.05) than at minimal blood flow (0.47 ± 0.05) (P < 0.01). In contrast, cortical FA-values were comparable at different timepoints of the cardiac cycle. ADC-values in the renal cortex as well as FA-values in the renal medulla are influenced by renal blood flow. This impact has to be considered when interpreting renal ADC- and FA-values. Copyright © 2012 Wiley Periodicals, Inc.

Preferential flow, connectivity and the principle of "minimum time to equilibrium": a new perspective on environmental water flow

NASA Astrophysics Data System (ADS)

Zehe, E.; Blume, T.; Bloeschl, G.

2008-12-01

Preferential/rapid flow and transport is known as one key process in soil hydrology for more than 20 years. It seems to be rather the rule, than the exception. It occurs in soils, in surface rills and river networks. If connective preferential are present at any scale, they crucially control water flow and solute transport. Why? Is there an underlying principle? If energy is conserved a system follows Fermat's principle of minimum action i.e. it follows the trajectory that minimise the integral of the total energy/ La Grangian over time. Hydrological systems are, however, non-conservative as surface and subsurface water flows dissipate energy. From thermodynamics it is well known that natural processes minimize the free energy of the system. For hydrological systems we suggest, therefore, that flow in a catchment arranges in such a way that time to a minimum of free energy becomes minimal for a given rainfall input (disturbance) and under given constraints. Free energy in a soil is determined by potential energy and capillary energy. The pore size distribution of the soil, soil structures, depth to groundwater and most important vegetation make up the constraints. The pore size distribution determines whether potential energy or capillarity dominates the free energy of the soil system. The first term is minimal when the pore space is completely de-saturated the latter becomes minimal at soil saturation. Hence, the soil determines a) the amount of excess (gravity) water that has to be exported from the soil to reach a minimum state of free energy and b) whether redistribution or groundwater recharge is more efficient to reach that equilibrium. On the other hand, the pore size distribution of the soil and the connectivity of preferential pathways (root channels, worm holes and cracks) determine flow velocities and the redistribution of water within the pore space. As water flow and ground water recharge are fast in sandy soils and capillary energy is of minor importance, connective preferential pathways do not mean any advantage for an efficient transition to an equilibrium in these systems. In fine grained soils Darcy velocities and therefore redistribution of water is 2-4 orders of magnitude slower. As capillary energy dominates in these soils an effective redistribution of water within the pore space is crucial for a fast transition of system to an equilibrium state. Connective preferential pathways ore even cracks allow a faster redistribution of water and seem therefore necessary for a fast transition into a state of minimum free energy. The suggested principle "of minimum time to equilibrium" may explain the "advantage" of preferential flow as a much more efficient dissipation of energy in fine grained soils and therefore why connective preferential pathways control environmental flow. From a fundamental, long term perspective the principle may help us to understand whether and why soil structures and even cracks evolve in different landscapes and climates and b) to link soil hydrology and (landscape) ecology. Along the lines the proposed study will present model results to test the stated hypothesis.

40 CFR 1066.125 - Data updating, recording, and control.

Code of Federal Regulations, 2014 CFR

2014-07-01

... minimum recording frequency, such as for sample flow rates from a CVS that does not have a heat exchanger... exhaust flow rate from a CVS with a heat exchanger upstream of the flow measurement 1 Hz. 40 CFR 1065.545§ 1066.425 Diluted exhaust flow rate from a CVS without a heat exchanger upstream of the flow measurement...

Water Use in Georgia by County for 2005; and Water-Use Trends, 1980-2005

USGS Publications Warehouse

Fanning, Julia L.; Trent, Victoria P.

2009-01-01

Water use for 2005 for each county in Georgia was estimated using data obtained from various Federal and State agencies and local sources. Total consumptive water use also was estimated for each county in Georgia for 2005. Water use is subdivided according to offstream and instream use. Offstream use is defined as water withdrawn or diverted from a ground- or surface-water source and transported to the place of use. Estimates for offstream water use include the categories of public supply, domestic, commercial, industrial, mining, irrigation, livestock, aquaculture, and thermoelectric power. Instream use is that which occurs within a stream channel for such purposes as hydroelectric-power generation, navigation, water-quality improvement, fish propagation, and recreation. The only category of instream use estimated was hydroelectric-power generation. Georgia law (the Georgia Ground-Water Use Act of 1972 and the Georgia Water Supply Act of 1978 [Georgia Department of Natural Resources, 2008a,b]) requires any water user who withdraws more than 100,000 gallons per day on a monthly average to obtain a withdrawal permit from the Georgia Environmental Protection Division. Permit holders generally must report their withdrawals by month. The Georgia Water-Use Program collects the reported information under the withdrawal permit system and the drinking-water permit system and stores the data in the Georgia Water-Use Data System.

Advancing the Food-Energy-Water Nexus: Closing Nutrient Loops in Arid River Corridors.

PubMed

Mortensen, Jacob G; González-Pinzón, Ricardo; Dahm, Clifford N; Wang, Jingjing; Zeglin, Lydia H; Van Horn, David J

2016-08-16

Closing nutrient loops in terrestrial and aquatic ecosystems is integral to achieve resource security in the food-energy-water (FEW) nexus. We performed multiyear (2005-2008), monthly sampling of instream dissolved inorganic nutrient concentrations (NH4-N, NO3-N, soluble reactive phosphorus-SRP) along a ∼ 300-km arid-land river (Rio Grande, NM) and generated nutrient budgets to investigate how the net source/sink behavior of wastewater and irrigated agriculture can be holistically managed to improve water quality and close nutrient loops. Treated wastewater on average contributed over 90% of the instream dissolved inorganic nutrients (101 kg/day NH4-N, 1097 kg/day NO3-N, 656 kg/day SRP). During growing seasons, the irrigation network downstream of wastewater outfalls retained on average 37% of NO3-N and 45% of SRP inputs, with maximum retention exceeding 60% and 80% of NO3-N and SRP inputs, respectively. Accurate quantification of NH4-N retention was hindered by low loading and high variability. Nutrient retention in the irrigation network and instream processes together limited downstream export during growing seasons, with total retention of 33-99% of NO3-N inputs and 45-99% of SRP inputs. From our synoptic analysis, we identify trade-offs associated with wastewater reuse for agriculture within the scope of the FEW nexus and propose strategies for closing nutrient loops in arid-land rivers.

Discrete-vortex simulation of pulsating flow on a turbulent leading-edge separation bubble

NASA Technical Reports Server (NTRS)

Sung, Hyung Jin; Rhim, Jae Wook; Kiya, Masaru

1992-01-01

Studies are made of the turbulent separation bubble in a two-dimensional semi-infinite blunt plate aligned to a uniform free stream with a pulsating component. The discrete-vortex method is applied to simulate this flow situation because this approach is effective for representing the unsteady motions of the turbulent shear layer and the effect of viscosity near the solid surface. The numerical simulation provides reasonable predictions when compared with the experimental results. A particular frequency with a minimum reattachment is related to the drag reduction. The most effective frequency is dependent on the amplified shedding frequency. The turbulent flow structure is scrutinized. This includes the time-mean and fluctuations of the velocity and the surface pressure, together with correlations between the fluctuating components. A comparison between the pulsating flow and the non-pulsating flow at the particular frequency of the minimum reattachment length of the separation bubble suggests that the large-scale vortical structure is associated with the shedding frequency and the flow instabilities.

On streak spacing in wall-bounded turbulent flows

NASA Technical Reports Server (NTRS)

Hamilton, James M.; Kim, John J.

1993-01-01

The present study is a continuation of the examination by Hamilton et al. of the regeneration mechanisms of near-wall turbulence and an attempt to investigate the conjecture of Waleffe et al. The basis of this study is an extension of the 'minimal channel' approach of Jimenez and Moin that emphasizes the near-wall region and reduces the complexity of the turbulent flow by considering a plane Couette flow of near minimum Reynolds number and stream-wise and span-wise extent. Reduction of the flow Reynolds number to the minimum value which will allow turbulence to be sustained has the effect of reducing the ratio of the largest scales to the smallest scales or, equivalently, of causing the near-wall region to fill more of the area between the channel walls. A plane Couette flow was chosen for study since this type of flow has a mean shear of a single sign, and at low Reynolds numbers, the two wall regions are found to share a single set of structures.

An economic analysis of selected strategies for dissolved-oxygen management; Chattahoochee River, Georgia

USGS Publications Warehouse

Schefter, John E.; Hirsch, Robert M.

1980-01-01

A method for evaluating the cost-effectiveness of alternative strategies for dissolved-oxygen (DO) management is demonstrated, using the Chattahoochee River, GA., as an example. The conceptual framework for the analysis is suggested by the economic theory of production. The minimum flow of the river and the percentage of the total waste inflow receiving nitrification are considered to be two variable inputs to be used in the production of given minimum concentration of DO in the river. Each of the inputs has a cost: the loss of dependable peak hydroelectric generating capacity at Buford Dam associated with flow augmentation and the cost associated with nitrification of wastes. The least-cost combination of minimum flow and waste treatment necessary to achieve a prescribed minimum DO concentration is identified. Results of the study indicate that, in some instances, the waste-assimilation capacity of the Chattahoochee River can be substituted for increased waste treatment; the associated savings in waste-treatment costs more than offset the benefits foregone because of the loss of peak generating capacity at Buford Dam. The sensitivity of the results to the estimates of the cost of replacing peak generating capacity is examined. It is also demonstrated that a flexible approach to the management of DO in the Chattahoochee River may be much more cost effective than a more rigid, institutional approach wherein constraints are placed on the flow of the river and(or) on waste-treatment practices. (USGS)

Tracer-aided modelling to explore non-linearities in flow paths, hydrological connectivity and faecal contamination risk

NASA Astrophysics Data System (ADS)

Neill, A. J.; Tetzlaff, D.; Strachan, N.; Soulsby, C.

2016-12-01

The non-linearities of runoff generation processes are strongly influenced by the connectivity of hillslopes and channel networks, particularly where overland flow is an important runoff mechanism. Despite major advances in understanding hydrological connectivity and runoff generation, the role of connectivity in the contamination of potable water supplies by faecal pathogens from grazing animals remains unclear. This is a water quality issue with serious implications for public health. Here, we sought to understand the dynamics of hydrological connectivity, flow paths and linked faecal pathogen transport in a montane catchment in Scotland with high deer populations. We firstly calibrated, within an uncertainty framework, a parsimonious tracer-aided hydrological model to daily discharge and stream isotope data. The model, developed on the basis of past empirical and tracer studies, conceptualises the catchment as three interacting hydrological source areas (dynamic saturation zone, dynamic hillslope, and groundwater) for which water fluxes, water ages and storage-based connectivity can be simulated. We next coupled several faecal indicator organism (FIO; a common indicator of faecal pathogen contamination) behaviour and transport schemes to the robust hydrological models. A further calibration was then undertaken based on the ability of each coupled model to simulate daily FIO concentrations. This gave us a final set of coupled behavioural models from which we explored how in-stream FIO dynamics could be related to the changing connectivity between the three hydrological source areas, flow paths, water ages and consequent dominant runoff generation processes. We found that high levels of FIOs were transient and episodic, and strongly correlated with periods of high connectivity through overland flow. This non-linearity in connectivity and FIO flux was successfully captured within our dynamic, tracer-aided hydrological model.

Review of Namibian legislation and policies pertinent to environmental flows

NASA Astrophysics Data System (ADS)

Bethune, Shirley; Amakali, Maria; Roberts, Kevin

The rationale for evaluating Namibian environmental flows is essentially that of ensuring ‘the maintenance of ecosystems, essential ecological processes and biological diversity’ and the sustainable utilisation of natural resources as promoted in clause 95 of the Namibian Constitution. Recent policy and legislative reforms have created a unique opportunity for Namibia to incorporate environmental sensitivity clauses such as those to ensure adequate environmental flows for river systems. The Second National Development Plan and the National Water Policy White Paper form the basis for the new Water Resources Management Act, promulgated in December 2004. The National Water Policy includes a basic principle headed “Ecosystem values and sustainability” that stresses that the management of water resources needs to harmonise human and environmental requirements, recognising the role of water in supporting the ecosystem. One of the strategies given to ensure environmental and economic sustainability reads: “Ensure that in-stream flows are adequate both in terms of quality and quantity to sustain the ecosystem”. Although the water policy clearly states that: “The legislation will provide for determining an environmental water reserve for freshwater sources before they can be used to supply other demands than domestic and subsistence livestock watering”, there is now no direct mention of environmental flows in the new Water Act. This paper explores to what extent the need for the determination of environmental water needs has been incorporated into Namibian policies, legislation and development plans. It makes recommendations, pertinent to the Namibian situation, of what needs to be done to ensure that environmental water requirements are taken into account in future planning, operation and management of Namibia’s precious water resources.

Evaluation of ecological instream flow using multiple ecological indicators with consideration of hydrological alterations

NASA Astrophysics Data System (ADS)

Zhang, Qiang; Gu, Xihui; Singh, Vijay P.; Chen, Xiaohong

2015-10-01

Dam-induced hydrological alterations and related ecological problems have been arousing considerable concern from hydrologists, ecologists, and policy-makers. The East River basin in China is the major provider of water resources for mega-cities within the Pearl River Delta and meets 80% of annual water demand of Hong Kong. In this study, ecodeficit and ecosurplus were analyzed to determine the ecological impact of water impoundments. Also, Do and DHRAM were employed to evaluate the degree of alteration of hydrological regimes, and ERHIs were analyzed to evaluate the influence of hydrological alterations on ecological diversity. Results indicate that: (1) the magnitude and frequency of high flows decrease and those of low flows increase due to the regulation of reservoirs; (2) variations of annual ecosurplus are mainly the result of precipitation changes and the annual ecodeficit is significantly influenced by reservoirs. However, ecodeficit and ecosurplus in other seasons, particularly autumn and winter, are more influenced by reservoir regulation; (3) impacts of reservoirs on hydrological regimes and eco-flow regimes are different from one station to another due to different degrees of influence of reservoirs on hydrological processes at different stations. The longer the distance between a reservoir and a hydrological station is, the weaker the influence the water reservoir has on the hydrological processes; (4) ecodeficit and ecosurplus can be accepted in the evaluation of alterations of hydrological processes at annual and seasonal time scales. Results of Shannon Index indicate decreasing biological diversity after the construction of water reservoirs, implying negative impacts of water reservoirs on biological diversity of a river basin and this should arouse considerable human concerns. This study provides a theoretical background for water resources management with consideration of eco-flow variations due to reservoir regulation in other highly-regulated river basins of the globe.

Impacts of coronary artery eccentricity on macro-recirculation and pressure drops using computational fluid dynamics

NASA Astrophysics Data System (ADS)

Poon, Eric; Thondapu, Vikas; Barlis, Peter; Ooi, Andrew

2017-11-01

Coronary artery disease remains a major cause of mortality in developed countries, and is most often due to a localized flow-limiting stenosis, or narrowing, of coronary arteries. Patients often undergo invasive procedures such as X-ray angiography and fractional flow reserve to diagnose flow-limiting lesions. Even though such diagnostic techniques are well-developed, the effects of diseased coronary segments on local flow are still poorly understood. Therefore, this study investigated the effect of irregular geometries of diseased coronary segments on the macro-recirculation and local pressure minimum regions. We employed an idealized coronary artery model with a diameter of stenosis of 75%. By systematically adjusting the eccentricity and the asymmetry of the coronary stenosis, we uncovered an increase in macro-recirculation size. Most importantly, the presence of this macro-recirculation signifies a local pressure minimum (identified by λ2 vortex identification method). This local pressure minimum has a profound effect on the pressure drops in both longitudinal and planar directions, which has implications for diagnosis and treatment of coronary artery disease. Supported by Australian Research Council LP150100233 and National Computational Infrastructure m45.

Multimodal pressure-flow method to assess dynamics of cerebral autoregulation in stroke and hypertension

PubMed Central

Novak, Vera; Yang, Albert CC; Lepicovsky, Lukas; Goldberger, Ary L; Lipsitz, Lewis A; Peng, Chung-Kang

2004-01-01

Background This study evaluated the effects of stroke on regulation of cerebral blood flow in response to fluctuations in systemic blood pressure (BP). The autoregulatory dynamics are difficult to assess because of the nonstationarity and nonlinearity of the component signals. Methods We studied 15 normotensive, 20 hypertensive and 15 minor stroke subjects (48.0 ± 1.3 years). BP and blood flow velocities (BFV) from middle cerebral arteries (MCA) were measured during the Valsalva maneuver (VM) using transcranial Doppler ultrasound. Results A new technique, multimodal pressure-flow analysis (MMPF), was implemented to analyze these short, nonstationary signals. MMPF analysis decomposes complex BP and BFV signals into multiple empirical modes, representing their instantaneous frequency-amplitude modulation. The empirical mode corresponding to the VM BP profile was used to construct the continuous phase diagram and to identify the minimum and maximum values from the residual BP (BPR) and BFV (BFVR) signals. The BP-BFV phase shift was calculated as the difference between the phase corresponding to the BPR and BFVR minimum (maximum) values. BP-BFV phase shifts were significantly different between groups. In the normotensive group, the BFVR minimum and maximum preceded the BPR minimum and maximum, respectively, leading to large positive values of BP-BFV shifts. Conclusion In the stroke and hypertensive groups, the resulting BP-BFV phase shift was significantly smaller compared to the normotensive group. A standard autoregulation index did not differentiate the groups. The MMPF method enables evaluation of autoregulatory dynamics based on instantaneous BP-BFV phase analysis. Regulation of BP-BFV dynamics is altered with hypertension and after stroke, rendering blood flow dependent on blood pressure. PMID:15504235

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.

Lateral, Vertical, and Longitudinal Source Area Connectivity Drive Runoff and Carbon Export Across Watershed Scales

NASA Astrophysics Data System (ADS)

Zimmer, Margaret A.; McGlynn, Brian L.

2018-03-01

Watersheds are three-dimensional hydrologic systems where the longitudinal expansion/contraction of stream networks, vertical connection/disconnection between shallow and deep groundwater systems, and lateral connectivity of these water sources to streams mediate runoff production and nutrient export. The connectivity of runoff source areas during both baseflow and stormflow conditions and their combined influence on biogeochemical fluxes remain poorly understood. Here we focused on a set of 3.3 and 48.4 ha nested watersheds (North Carolina, USA). These watersheds comprise ephemeral and intermittent runoff-producing headwaters and perennial runoff-producing lowlands. Within these landscape elements, we characterized the timing and magnitude of precipitation, runoff, and runoff-generating flow paths. The active surface drainage network (ASDN) reflected connectivity to, and contributions from, source areas that differed under baseflow and stormflow conditions. The baseflow-associated ASDN expanded and contracted seasonally, driven by the rise and fall of the seasonal water table. Superimposed on this were event-activated source area contributions driven by connectivity to surficial and shallow subsurface flow paths. Frequently activated shallow flow paths also caused increased in-stream dissolved organic carbon (DOC) concentrations with increases in runoff across both watershed scales. The spread and variability within this DOC-runoff relationship was driven by a seasonal depletion of DOC from continual shallow subsurface flow path activation and subsequent replenishment from autumn litterfall. Our findings suggest that hydrobiogeochemical signals at larger watershed outlets can be driven by the expansion, contraction, and connection of lateral, longitudinal, and vertical source areas with distinct runoff generation processes.

Nutrient attenuation in rivers and streams, Puget Sound Basin, Washington

USGS Publications Warehouse

Sheibley, Rich W.; Konrad, Christopher P.; Black, Robert W.

2015-01-01

From a management perspective, preservation and improvement of instream nutrient attenuation should focus on increasing the travel time through a reach and contact time of water sediment (reactive) surfaces and lowering nutrient concentrations (and loads) to avoid saturation of instream attenuation and increase attenuation efficiency. These goals can be reached by maintaining and restoring channel-flood plain connectivity, maintaining and restoring healthy riparian zones along streams, managing point and nonpoint nutrient loads to streams and rivers, and restoring channel features that promote attenuation such as the addition of woody debris and maintaining pool-riffle morphologies. Many of these management approaches are already being undertaken during projects aimed to restore quality salmon habitat. Therefore, there is a dual benefit to these projects that also may lead to enhanced potential for nitrogen and phosphorus attenuation.

Instream flow characterization of Upper Salmon River basin streams, central Idaho, 2005

USGS Publications Warehouse

Maret, Terry R.; Hortness, Jon E.; Ott, Douglas S.

2006-01-01

Anadromous fish populations in the Columbia River Basin have plummeted in the last 100 years. This severe decline led to Federal listing of Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) stocks as endangered or threatened under the Endangered Species Act (ESA) in the 1990s. Historically, the upper Salmon River Basin (upstream of the confluence with the Pahsimeroi River) in Idaho provided migration corridors and significant habitat for these ESA-listed species, in addition to the ESA-listed bull trout (Salvelinus confluentus). Human development has modified the original streamflow conditions in many streams in the upper Salmon River Basin. Summer streamflow modifications resulting from irrigation practices, have directly affected quantity and quality of fish habitat and also have affected migration and (or) access to suitable spawning and rearing habitat for these fish. As a result of these ESA listings and Action 149 of the Federal Columbia River Power System Biological Opinion of 2000, the Bureau of Reclamation was tasked to conduct streamflow characterization studies in the upper Salmon River Basin to clearly define habitat requirements for effective species management and habitat restoration. These studies include collection of habitat and streamflow information for the Physical Habitat Simulation System (PHABSIM) model, a widely applied method to determine relations between habitat and discharge requirements for various fish species and life stages. Model simulation results can be used by resource managers to guide habitat restoration efforts by evaluating potential fish habitat and passage improvements by increasing or decreasing streamflow. In 2005, instream flow characterization studies were completed on Big Boulder, Challis, Bear, Mill, and Morgan Creeks. Continuous streamflow data were recorded upstream of all diversions on Big Boulder. Instantaneous measurements of discharge were also made at selected sites. In addition, natural summer streamflows were estimated for each study site using regional regression equations. This report describes PHABSIM modeling results for bull trout, Chinook salmon, and steelhead trout during summer streamflows. Habitat/discharge relations were summarized for adult and spawning life stages at each study site. In addition, streamflow needs for riffle dwelling invertebrate taxa (Ephemeroptera, Plecoptera, and Trichoptera) are presented. Adult fish passage and discharge relations were evaluated at specific transects that were identified as potential low-streamflow passage barriers at each study site. Continuous summer water temperature data for selected study sites were summarized and compared with Idaho Water Quality Standards and various water temperature requirements of targeted fish species. Results of these habitat studies can be used to prioritize and direct cost-effective actions to improve fish habitat for ESA-listed anadromous and native fish species in the basin. These actions may include acquiring water during critical low-flow periods by leasing or modifying irrigation delivery systems to minimize out-of-stream diversions.

Instream flow characterization of upper Salmon River Basin streams, Central Idaho, 2003

USGS Publications Warehouse

Maret, Terry R.; Hortness, Jon E.; Ott, Douglas S.

2004-01-01

Anadromous fish populations in the Columbia River Basin have plummeted in the last 100 years. This severe decline led to Federal listing of chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) stocks as endangered or threatened under the Endangered Species Act (ESA) in the 1990s. Historically, the upper Salmon River Basin (upstream from the confluence with the Pahsimeroi River) in Idaho provided migration corridors and significant habitat for these ESA-listed species, in addition to the federally listed bull trout (Salvelinus confluentus). Human development has modified the original streamflow conditions in many streams in the upper Salmon River Basin. Summer streamflow modifications, as a result of irrigation practices, have directly affected the quantity and quality of fish habitat and also have affected migration and (or) access to suitable spawning and rearing habitat for these fish. As a result of these ESA listings and Action 149 of the Federal Columbia River Power System Biological Opinion of 2000, the Bureau of Reclamation was tasked to conduct streamflow characterization studies in the upper Salmon River Basin to clearly define habitat requirements for effective species management and habitat restoration. These studies include the collection of habitat and streamflow information for the Physical Habitat Simulation (PHABSIM) model, a widely applied method to determine relations between habitat and discharge requirements for various fish species and life stages. Model results can be used by resource managers to guide habitat restoration efforts in the evaluation of potential fish habitat and passage improvements by increasing streamflow. Instream flow characterization studies were completed on Pole, Fourth of July, Elk, and Valley Creeks during 2003. Continuous streamflow data were collected upstream from all diversions on each stream. In addition, natural summer streamflows were estimated for each study site using regression equations. PHABSIM results are presented for bull trout, chinook salmon, and steelhead trout over a range of summer streamflows. Habitat/discharge relations are summarized for juvenile, adult, and spawning life stages at each study site. Adult fish passage and discharge relations are evaluated at specific transects identified as a potential low-streamflow passage barrier at each study site. Continuous summer water temperature data for selected study sites also are summarized and compared with Idaho Water Quality Standards and various temperature requirements of targeted fish species. Results of these habitat studies can be used to prioritize and direct cost-effective actions to improve fish habitat for ESA-listed anadromous and native fish species in the basin. These actions may include acquiring water during critical low-flow periods by leasing or modifying irrigation delivery systems to minimize out-of-stream diversions.

Statistical summaries of streamflow data for selected gaging stations on and near the Idaho National Engineering Laboratory, Idaho, through September 1990

USGS Publications Warehouse

Stone, M.A.J.; Mann, Larry J.; Kjelstrom, L.C.

1993-01-01

Statistical summaries and graphs of streamflow data were prepared for 13 gaging stations with 5 or more years of continuous record on and near the Idaho National Engineering Laboratory. Statistical summaries of streamflow data for the Big and Little Lost Rivers and Birch Creek were analyzed as a requisite for a comprehensive evaluation of the potential for flooding of facilities at the Idaho National Engineering Laboratory. The type of statistical analyses performed depended on the length of streamflow record for a gaging station. Streamflow statistics generated for stations with 5 to 9 years of record were: (1) magnitudes of monthly and annual flows; (2) duration of daily mean flows; and (3) maximum, median, and minimum daily mean flows. Streamflow statistics generated for stations with 10 or more years of record were: (1) magnitudes of monthly and annual flows; (2) magnitudes and frequencies of daily low, high, instantaneous peak (flood frequency), and annual mean flows; (3) duration of daily mean flows; (4) exceedance probabilities of annual low, high, instantaneous peak, and mean annual flows; (5) maximum, median, and minimum daily mean flows; and (6) annual mean and mean annual flows.

Determining Coolant Flow Rate Distribution In The Fuel-Modified TRIGA Plate Reactor

NASA Astrophysics Data System (ADS)

Puji Hastuti, Endiah; Widodo, Surip; Darwis Isnaini, M.; Geni Rina, S.; Syaiful, B.

2018-02-01

TRIGA 2000 reactor in Bandung is planned to have the fuel element replaced, from cylindrical uranium and zirconium-hydride (U-ZrH) alloy to U3Si2-Al plate type of low enriched uranium of 19.75% with uranium density of 2.96 gU/cm3, while the reactor power is maintained at 2 MW. This change is planned to anticipate the discontinuity of TRIGA fuel element production. The selection of this plate-type fuel element is supported by the fact that such fuel type has been produced in Indonesia and used in MPR-30 safely since 2000. The core configuration of plate-type-fuelled TRIGA reactor requires coolant flow rate through each fuel element channel in order to meet its safety function. This paper is aimed to describe the results of coolant flow rate distribution in the TRIGA core that meets the safety function at normal operation condition, physical test, shutdown, and at initial event of loss of coolant flow due power supply interruption. The design analysis to determine coolant flow rate in this paper employs CAUDVAP and COOLODN computation code. The designed coolant flow rate that meets the safety criteria of departure from nucleate boiling ratio (DNBR), onset of flow instability ratio (OFIR), and ΔΤ onset of nucleate boiling (ONB), indicates that the minimum flow rate required to cool the plate-type fuelled TRIGA core at 2 MW is 80 kg/s. Therefore, it can be concluded that the operating limitation condition (OLC) for the minimum flow rate is 80 kg/s; the 72 kg/s is to cool the active core; while the minimum flow rate for coolant flow rate drop is limited to 68 kg/s with the coolant inlet temperature 35°C. This thermohydraulic design also provides cooling for 4 positions irradiation position (IP) utilization and 1 central irradiation position (CIP) with end fitting inner diameter (ID) of 10 mm and 20 mm, respectively.

Comparison of Implicit Schemes for the Incompressible Navier-Stokes Equations

NASA Technical Reports Server (NTRS)

Rogers, Stuart E.

1995-01-01

For a computational flow simulation tool to be useful in a design environment, it must be very robust and efficient. To develop such a tool for incompressible flow applications, a number of different implicit schemes are compared for several two-dimensional flow problems in the current study. The schemes include Point-Jacobi relaxation, Gauss-Seidel line relaxation, incomplete lower-upper decomposition, and the generalized minimum residual method preconditioned with each of the three other schemes. The efficiency of the schemes is measured in terms of the computing time required to obtain a steady-state solution for the laminar flow over a backward-facing step, the flow over a NACA 4412 airfoil, and the flow over a three-element airfoil using overset grids. The flow solver used in the study is the INS2D code that solves the incompressible Navier-Stokes equations using the method of artificial compressibility and upwind differencing of the convective terms. The results show that the generalized minimum residual method preconditioned with the incomplete lower-upper factorization outperforms all other methods by at least a factor of 2.

Modeling Food Delivery Dynamics For Juvenile Salmonids Under Variable Flow Regimes

NASA Astrophysics Data System (ADS)

Harrison, L.; Utz, R.; Anderson, K.; Nisbet, R.

2010-12-01

Traditional approaches for assessing instream flow needs for salmonids have typically focused on the importance of physical habitat in determining fish habitat selection. This somewhat simplistic approach does not account for differences in food delivery rates to salmonids that arise due to spatial variability in river morphology, hydraulics and temporal variations in the flow regime. Explicitly linking how changes in the flow regime influences food delivery dynamics is an important step in advancing process-based bioenergetic models that seek to predict growth rates of salmonids across various life-stages. Here we investigate how food delivery rates for juvenile salmonids vary both spatially and with flow magnitude in a meandering reach of the Merced River, CA. We utilize a two-dimensional (2D) hydrodynamic model and discrete particle tracking algorithm to simulate invertebrate drift transport rates at baseflow and a near-bankfull discharge. Modeling results indicate that at baseflow, the maximum drift density occurs in the channel thalweg, while drift densities decrease towards the channel margins due to the process of organisms settling out of the drift. During high-flow events, typical of spring dam-releases, the invertebrate drift transport pathway follows a similar trajectory along the high velocity core and the drift concentrations are greatest in the channel centerline, though the zone of invertebrate transport occupies a greater fraction of the channel width. Based on invertebrate supply rates alone, feeding juvenile salmonids would be expected to be distributed down the channel centerline where the maximum predicted food delivery rates are located in this reach. However, flow velocities in these channel sections are beyond maximum sustainable swimming speeds for most juvenile salmonids. Our preliminary findings suggest that a lack of low velocity refuge may prevent juvenile salmonids from deriving energy from the areas with maximum drift density in this reach. Future efforts will focus on integration of food delivery and bioenergetic models to account for conflicting demands of maximizing food intake while minimizing the energetic costs of swimming.

Effects of fluctuating flows and a controlled flood on incubation success and early survival rates and growth of age-0 rainbow trout in a large regulated river

USGS Publications Warehouse

Korman, Josh; Kaplinski, Matthew; Melis, Theodore S.

2011-01-01

Hourly fluctuations in flow from Glen Canyon Dam were increased in an attempt to limit the population of nonnative rainbow trout Oncorhynchus mykiss in the Colorado River, Arizona, due to concerns about negative effects of nonnative trout on endangered native fishes. Controlled floods have also been conducted to enhance native fish habitat. We estimated that rainbow trout incubation mortality rates resulting from greater fluctuations in flow were 23-49% (2003 and 2004) compared with 5-11% under normal flow fluctuations (2006-2010). Effects of this mortality were apparent in redd excavations but were not seen in hatch date distributions or in the abundance of the age-0 population. Multiple lines of evidence indicated that a controlled flood in March 2008, which was intended to enhance native fish habitat, resulted in a large increase in early survival rates of age-0 rainbow trout. Age-0 abundance in July 2008 was over fourfold higher than expected given the number of viable eggs that produced these fish. A hatch date analysis indicated that early survival rates were much higher for cohorts that hatched about 1 month after the controlled flood (~April 15) relative to those that hatched before this date. The cohorts that were fertilized after the flood were not exposed to high flows and emerged into better-quality habitat with elevated food availability. Interannual differences in age-0 rainbow trout growth based on otolith microstructure supported this hypothesis. It is likely that strong compensation in survival rates shortly after emergence mitigated the impact of incubation losses caused by increases in flow fluctuations. Control of nonnative fish populations will be most effective when additional mortality is applied to older life stages after the majority of density-dependent mortality has occurred. Our study highlights the need to rigorously assess instream flow decisions through the evaluation of population-level responses.