SummaryUnderstanding streamflow patterns in space and time is important for improving flood and drought forecasting, water resources management, and predictions of ecological changes. Objectives of this work include (a) to characterize the spatial and temporal patterns of streamflow using information theory-based measures at two thoroughly-monitored agricultural watersheds located in different hydroclimatic zones with similar land use, and (b) to elucidate and quantify temporal and spatial scale effects on those measures. We selected two USDA experimental watersheds to serve as case study examples, including the Little River experimental watershed (LREW) in Tifton, Georgia and the Sleepers River experimental watershed (SREW) in North Danville, Vermont. Both watersheds possess several neste...

A goal of the Urban Watershed Management Branch of USEPA's NRMRL, Edison, NJ is to develop and demonstrate technologies and methods to manage the ecological risks posed by stormwate runoff from highly developed watersheds. This study, in particular, uses extant data and controlle...

The study and management of ecosystems represents the most dynamic field of contemporary ecology. Ecosystem research bridges fundamental ecology, environmental ecology and environmental problem-solving. The scope of ecosystem science extends from bounded systems such as watersheds to spatially...

Irrigated agriculture notably increases crop productivity, but the generated irrigation return flows may induce surface water pollution by nutrients if irrigation water and fertilization management are inadequate. In this study, the Del Reguero watershed (Huesca, Spain) was characterized, and irriga...

Encroachment of woody vegetation into traditional savanna grassland ecosystems in central Texas has largely been attributed to land use practices of settlers, most notably overgrazing and fire suppression. Implementing brush management practices (removing the woody vegetation and allowing native grasses to reestablish in the area), could potentially change the hydrology in a watershed. The U.S. Geological Survey, in cooperation with several local, State, and Federal cooperators, studied the hydrologic effects of ashe juniper (Juniperus ashei) removal as a brush management conservation practice in the Honey Creek State Natural Area in Comal County, Tex. Two adjacent watersheds of 104 and 159 hectares were used in a paired study. Rainfall, streamflow, evapotranspiration (Bowen ratio method), and water quality data were collected in both watersheds. Using a hydrologic mass balance approach, rainfall was allocated to surface-water runoff, evapotranspiration, and groundwater recharge. Groundwater recharge was not directly measured, but estimated as the residual of the hydrologic mass balance. After hydrologic data were collected in both watersheds for 3 years, approximately 80 percent of the woody vegetation (ashe juniper) was selectively removed from the 159 hectare watershed (treatment watershed). Brush management was not implemented in the other (reference) watershed. Hydrologic data were collected in both watersheds for six years after brush management implementation. The resulting data were examined for differences in the hydrologic budget between the reference and treatment watersheds as well as between pre- and post-brush management periods to assess effects of the treatment. Preliminary results indicate there are differences in the hydrologic budget as well as water quality between the watersheds during pre- and post-treatment periods.

Distributed parameter watershed models are often used for evaluating the effectiveness of various best management practices (BMPs). Streamflow, sediment, and nutrient yield predictions of a watershed model can be affected by spatial resolution as dictated by watershed subdivisio...

Buffers have been found to reduce non-point source pollution (NPSP) from watersheds. Hydrologic simulation models assist in predicting the effects of buffers on runoff and sediment losses from small watersheds. The objective of this study was to calibrate, validate and simulate runoff and sediment losses and compare buffer effects on NPSP losses relative to control watersheds (no buffer) for seven years. The experimental design consists of four watersheds under pasture management which were monitored from 2002 through 2008; two with agroforestry buffers (AgB 100 and AgB 300) and two control watersheds (CW 400 and CW 600). Pasture areas included red clover (Trifolium pretense L.) and lespedeza (Kummerowia stipulacea Maxim.) planted into fescue (Festuca arundinacea Schreb.) while the agrofor...

Estimation of base cation supply from mineral weathering (BCw) is useful for watershed research and management. Existing regional approaches for estimating BCw require generalized assumptions and availability of stream chemistry data. We developed an approach for estimating BCw using regionally specific empirical relationships. The dynamic model MAGIC was used to calibrate BCw in 92 watersheds distributed across three ecoregions. Empirical relationships between MAGIC-simulated BCw and watershed characteristics were developed to provide the basis for regionalization of BCw throughout the entire study region. BCw estimates extracted from MAGIC calibrations compared reasonably well with BCw estimated by regression based on landscape characteristics. Approximately one-third of the study region...

This paper presents an integrated approach to landscape functioning assessment combining energy efficiency and hydrochemical balance studies. Energy balance is expressed by surface temperature while hydrochemical balance is illustrated by electric conductivity and selected hydrochemical parameters. Six model sub-watersheds with different land use situated in southern Bohemia were chosen to show the influence of landscape management on landscape functioning. The watersheds with higher humankind activity were shown to have both higher and more fluctuating average surface temperature as well as higher electrical conductivity in the runoff surface water. Watersheds with the predominance of forests and meadows showed opposite trends in the monitored parameters. Our results show that sustainable...

The Croton Watershed is unique among New York City's water-supply watersheds because it has the highest percentages of suburban development (52 percent) and wetland area (6 percent). As the City moves toward filtration of this water supply, there is a need to document water-quality contributions from both human and natural sources within the watershed that can inform watershed-management decisions.\\r\

This study assessed fecal coliform contamination in the Wachusett Reservoir Watershed in Massachusetts, USA using Soil and Water Assessment Tool (SWAT) because bacteria are one of the major water quality parameters of concern. The bacteria subroutine in SWAT, considering in-stream bacteria die-off only, was modified in this study to include solar radiation-associated die-off and the contribution of wildlife. The result of sensitivity analysis demonstrates that solar radiation is one of the most significant fate factors of fecal coliform. A water temperature-associated function to represent the contribution of beaver activity in the watershed to fecal contamination improved prediction accuracy. The modified SWAT model provides an improved estimate of bacteria from the watershed. Our approach will be useful for simulating bacterial concentrations to provide predictive and reliable information of fecal contamination thus facilitating the implementation of effective watershed management. PMID:22784807

This study focuses on the development of a multi-objective game-theory model (MOGM) for balancing economic and environmental concerns in reservoir watershed management and for assistance in decision. Game theory is used as an alternative tool for analyzing strategic interaction between economic development (land use and development) and environmental protection (water-quality protection and eutrophication control). Geographic information system is used to concisely illustrate and calculate the areas of various land use types. The MOGM methodology is illustrated in a case study of multi-objective watershed management in the Tseng-Wen reservoir, Taiwan. The innovation and advantages of MOGM can be seen in the results, which balance economic and environmental concerns in watershed management and which can be interpreted easily by decision makers. For comparison, the decision-making process using conventional multi-objective method to produce many alternatives was found to be more difficult. PMID:22284980

We compared classification schemes based on watershed storage (wetland + lake area/watershed area) and forest fragmention with a gewographically-based classification scheme for two case studies involving 1) Lake Superior tributaries and 2) watersheds of riverine coastal wetlands ...

Summary The present study aimed at defining and testing a simple and widely applicable management tool, based on already available or easily collectable data, which could allow Watershed Authorities to prioritize the interventions for river longitudinal connectivity restoration, reopening fish migration routes. The proposed priority indices for fish passes are based on obstacle characteristics, length of the potential reopened reach and fish species distribution and migratory behaviour. The indices were applied to two Italian watersheds (Arno and Magra Rivers) covering a total river length of more than 400-km. The priority lists produced by the application can function as a first step in defining a watershed restoration plan and could help the Watershed Authorities to address the available...

The lack of land use planning and the absence of conservation practices in a watershed can contribute to increased runoff, soil loss, and nutrient transport, which compromise the environmental quality in a watershed, especially the water resources. The objective of this study was to assess the contribution of conservation practices in reducing runoff and soil and nutrient losses using the Soil and Water Assessment Tool (SWAT) in the São Bartolomeu Stream Watershed, which is a significant watershed in Brazil. The modeling allowed us to identify critical areas regarding sediment yield, runoff, and nutrient loss. After that, conservation practices aimed at reducing the impacts of such processes were simulated. We also identified the most sensitive model parameters to simulate changes in manag...

The La Antigua watershed drains into the Gulf of Mexico and can be considered as one of the most important areas in Mexico because of its high productivity, history, and biodiversity, although poverty remains high in the area in spite of these positive attributes. In this study, we performed an integrated assessment of the watershed to recommend a better direction toward a sustainable management in which the four capitals (natural, human, social, and built) are balanced. We contrasted these four capitals in the municipalities of the upper, middle and lower watershed and found that natural capital (natural ecosystems and ecosystem services) was higher in the upper and middle watershed, while human and social capitals (literacy, health, education and income) were generally higher downstream. Overall, Human Development Index was negatively correlated with the percentage of natural ecosystems in the watershed, especially in the upper and lower watershed regions. Our results indicate that natural capital must be fully considered in projections for increasing human development, so that natural resources can be preserved and managed adequately while sustaining intergenerational well-being. PMID:23129241

Agricultural non-point source (NPS) pollution, primarily sediment and nutrients, is the leading source of water-quality impacts to surface waters in North America. The overall goal of this study was to develop geographic information system (GIS) protocols to facilitate the spatial and temporal modeling of changes in soils, hydrology, and land-cover change at the watershed scale. In the first part of this article, we describe the use of GIS to spatially integrate watershed scale data on soil erodibility, land use, and runoff for the assessment of potential source areas within an intensively agricultural watershed. The agricultural non-point source pollution (AGNPS) model was used in the Muddy Creek, Ontario, watershed to evaluate the effectiveness of management strategies in decreasing sediment and nutrient [phosphorus (P)] pollution. This analysis was accompanied by the measurement of water-quality parameters (dissolved oxygen, pH, hardness, alkalinity, and turbidity) as well as sediment and P loadings to the creek. Practices aimed at increasing year-round soil cover would be most effective in decreasing sediment and P losses in this watershed. In the second part of this article, we describe a method for characterizing land-cover change in a dynamic urban fringe watershed. The GIS method we developed for the Blackberry Creek, Illinois, watershed will allow us to better account for temporal changes in land use, specifically corn and soybean cover, on an annual basis and to improve on the modeling of watershed processes shown for the Muddy Creek watershed. Our model can be used at different levels of planning with minimal data preprocessing, easily accessible data, and adjustable output scales. PMID:22983655

Nutrient runoff from agricultural fields threatens water quality and can impair habitats in many watersheds. Agencies consider these potential risks as they determine acceptable levels of nutrient loading. For example, in the New York City (NYC) watershed, the Environmental Protection Agency's Total Maximum Daily Load (TMDL) for phosphorus (P) has been set at 15?g P L-1 to protect against eutrophication and bacterial outbreaks. In the NYC watersheds agricultural Best Management Practices (BMPs) are the primary means to control nonpoint source P loading. BMPs include riparian buffers, filter strips, manure storage facilities, crop rotation, stripcropping, tree planting and nutrient management plans (NMPs). Water quality research on BMPs to date has included studies on site-specificity of different BMPs, short and long term BMP efficacy, and placement of BMPs with respect to critical source areas. A necessary complement to studies addressing water quality aspects of different BMPs are studies examining the cost-benefit aspects of BMPs. In general, there are installment, maintenance and opportunity costs associated with each BMP, and there are benefits, including cost share agreements between farmers and farm agencies, and increased efficiency of farm production and maintenance. Combining water quality studies and related cost-benefit analyses would help planners and watershed managers determine how best improve water quality. Our research examines the costs-benefit structure associated with BMP scenarios on a one-farm headwater watershed in the Catskill Mountains of NY. The different scenarios include "with and without" BMPs, combinations of BMPs, and different BMP placements across agricultural fields. The costs associated with each BMP scenarios are determined using information from farm agencies and watershed planning agencies. With these data we perform a cost-benefit analysis for the different BMP scenarios and couple the water quality modeling using the Variable Source Loading Function (VSLF) model (Schneiderman et al., 2007) with the cost-benefit analysis to look at the specific water quality and economic consequences of different watershed management scenarios. The results of our study will be useful for planners and watershed managers in determining how best to reduce nonpoint source pollution in a cost-effective manner. References Schneiderman, E.M., T.S. Steenhuis, D.J. Thongs, Z.M. Easton, M.S. Zion, G.F. Mendoza, M.T. Walter, and A.C. Neal. 2007. Incorporating variable source area hydrology into curve number based watershed loading functions. Hydrol. Proc. (In Press).

The Grays River Watershed and Biological Assessment was funded to address degradation and loss of spawning habitat for chum salmon (Onchorhynchus keta) and fall Chinook salmon (Onchoryhnchus tshawytscha). In 1999, the National Marine Fisheries Service listed lower Columbia River chum salmon as a threatened Evolutionarily Significant Unit (ESU) under the Endangered Species Act of 1973 (ESA). The Grays River watershed is one of two remaining significant chum salmon spawning locations in this ESU. Runs of Grays River chum and Chinook salmon have declined significantly during the past century, largely because of damage to spawning habitat associated with timber harvest and agriculture in the watershed. In addition, approximately 20-25% of the then-remaining chum salmon spawning habitat was lost during a 1999 channel avulsion that destroyed an important artificial spawning channel operated by the Washington Department of Fish and Wildlife (WDFW). Although the lack of stable, high-quality spawning habitat is considered the primary physical limitation on Grays River chum salmon production today, few data are available to guide watershed management and channel restoration activities. The objectives of the Grays River Watershed and Biological Assessment project were to (1) perform a comprehensive watershed and biological analysis, including hydrologic, geomorphic, and ecological assessments; (2) develop a prioritized list of actions that protect and restore critical chum and Chinook salmon spawning habitat in the Grays River based on comprehensive geomorphic, hydrologic, and stream channel assessments; and (3) gain a better understanding of chum and Chinook salmon habitat requirements and survival within the lower Columbia River and the Grays River. The watershed-based approach to river ecosystem restoration relies on a conceptual framework that describes general relationships between natural landscape characteristics, watershed-scale habitat-forming processes, aquatic habitat conditions, and biological integrity. In addition, human land-use impacts are factored into the conceptual model because they can alter habitat quality and can disrupt natural habitat-forming processes. In this model (Figure S.1), aquatic habitat--both instream and riparian--is viewed as the link between watershed conditions and biologic responses. Based on this conceptual model, assessment of habitat loss and the resultant declines in salmonid populations can be conducted by relating current and historical (e.g., natural) habitat conditions to salmonid utilization, diversity, and abundance. In addition, assessing disrupted ecosystem functions and processes within the watershed can aid in identifying the causes of habitat change and the associated decline in biological integrity. In this same way, restoration, enhancement, and conservation projects can be identified and prioritized. A watershed assessment is primarily a landscape-scale evaluation of current watershed conditions and the associated hydrogeomorphic riverine processes. The watershed assessment conducted for this project focused on watershed processes that form and maintain salmonid habitat. Landscape metrics describing the level of human alteration of natural ecosystem attributes were used as indicators of water quality, hydrology, channel geomorphology, instream habitat, and biotic integrity. Ecological (watershed) processes are related to and can be predicted based on specific aspects of spatial pattern. This study evaluated the hydrologic regime, sediment delivery regime, and riparian condition of the sub-watersheds that comprise the upper Grays River watershed relative to their natural range of conditions. Analyses relied primarily on available geographic information system (GIS) data describing landscape characteristics such as climate, vegetation type and maturity, geology and soils, topography, land use, and road density. In addition to watershed-scale landscape characteristics, the study area was also evaluated on the riparian scale, with appropriate landscape variables analyzed within

Watershed water quality models are widely used in management practices such as Total Maximum Daily Loads (TMDLs). However, the modeling often involves significant uncertainty, especially in addressing non-conventional pollutants on which both knowledge and data are very limited. In this study, the Deterministic Equivalent Modeling Method (DEMM), incorporating the Probabilistic Collocation Method (PCM), is used as an efficient alternative to conventional Monte Carlo Simulation (MCS) for uncertainty analysis. DEMM is one of the Response Surface Methods (RSMs) which calculates uncertainty in output variables based on the direct effect of every uncertain input parameter. This study aims to 1) examine the applicability of DEMM to complex watershed models; 2) develop strategies for identifying major uncertainty sources in watershed water quality modeling. A case study of watershed diazinon (an organophosphorus pesticide) pollution modeling is explored. The results demonstrate that the stochastic response of the output variables to the uncertain input parameters can be adequately approximated by DEMM. A low-order DEMM can save a great amount of CPU time, compared to MCS. Also, DEMM can be used for parameter sensitivity analysis and preliminary model validation without a full calibration of the watershed model. Overall, if designed appropriately, DEMM can be used to identify major sources of uncertainty in watershed water quality modeling, and provides useful information on improving the modeling.

Quantifying the effects of forest changes on hydrology in large watersheds is important for designing forest or land management and adaptation strategies for watershed ecosystem sustainability. Minjiang River watershed located in the upper reach of the Yangtze River Basin plays a strategic role in environmental protection and economic and social wellbeing for both the watershed and the entire Yangtze Basin. The watershed lies in the transition zone from Sichuan Basin to Qinghai-Tibet Plateau with a size of 24 000 km2. Due to its strategic significance, severe historic deforestation and high sensitivity to climate change, the watershed has long been one of the highest priority watersheds in China for scientific research and resource management. The purpose of this review paper is to provide a state-of-the-art summary on what we have learned from several recently-completed research programs (one of them known as "973 of the China National Major Fundamental Science" with funding of 3.5 million USD in 2002 to 2008). This summary paper focused on how land cover or forest change affected hydrology at both forest stand and watershed scales in this large watershed. Inclusion of two different spatial scales is useful because the results from a small spatial scale (e.g. forest stand level) can help interpret the findings at a large spatial scale. Our review suggests that historic forest harvesting or land cover change has caused significant water increase due to reduction of forest canopy interception and evapotranspiration caused by removal of forest vegetation at both spatial scales. The impact magnitudes caused by forest harvesting indicate that the hydrological effects of forest or land cover changes can be as important as those caused by climate change, while the opposite impact directions suggest their offsetting effects on water yields in the Minjiang River watershed. In addition, different types of forests have different magnitudes of ET with old-growth natural coniferous (Abies) forests being the lowest and the coniferous plantations (e.g. Spruce) being the highest among major forest types in the study watershed, suggesting that selection of different types of forests can have an important role in ET and consequently water yields. Our synthesis indicates that future reforestation and climate change would likely produce the hydrological effects in the same direction and thus place double pressures on water resource as both key drivers may lead to water yield reduction. Implications of the findings are also discussed in the context of future land cover and climate changes.

This paper is a case study of the Union of Raba River Communities in Poland. The City of Cracow receives 60% of its water from the Dobczyce Reservoir, which is located in the Raba River Watershed. The water quality in this reservoir is threatened by pollution from non-point sources and untreated sewage. Because the reservoir and watershed are located outside of Cracow, protecting the water quality falls to communities that do not use the Reservoir. To meet this responsibility, communities in the watershed formed the Union of Raba River Communities (the Union). The Union hired a Cracow consulting firm to conduct a study of watershed management options, which was completed in January 1996. The Union is now evaluating the plan and looking for funding for implementation. The Union is also addressing specific problems in the watershed, including the siting of a much needed but unpopular landfill. There are numerous sources of pollution in the watershed including: sewage; runoff from urban areas, roads, agriculture, logged areas, landfills and dumps, fertilizer and pesticide storage areas, and petrol stations; and air pollution.

PURPOSE: The quality of fish produced in ponds needs to be ensured. Indeed, pond is often strongly connected to an agricultural watershed, and pesticides are a main health and environmental issue of concern. In this context, the purpose of this study is to highlight the management practices which could impact the pesticide contamination profiles in edible fish and to give recommendations for better practices. METHODS: A principal component analysis, coupled to a hierarchical cluster analysis, was performed to evaluate temporal evolution of contamination profiles and to assess variability among fish species and among sites according to watershed characteristics. The explicative variables correspond to muscular concentrations of pesticides (azoxystrobin, clomazone, diflufenican, carbendazim, isoproturon, metazachlor, napropamid) in three species of fish (Perca fluviatilis, Cyprinus carpio and Rutilus rutilus), caught in five ponds during two sampling campaigns. Management data are added variables in order to discuss about parameters suspected to be implicated in the contamination profiles recorded. RESULTS: This work shows that high amounts of pesticides applied, short crop rotation durations and bare soil practices led to contamination of sediments and fish and were associated to a "bad" management of watershed. Breeding fish that had low masses and establishing the fishing period at the end of winter seemed to be "bad" management of pond. Aggravating topological parameters were big watershed coupled to small pond and high proportions of sand soils in the watershed. CONCLUSIONS: Reducing amounts of pesticide used (e.g. policy agency plans, farmer acceptance), favouring long-term rotations and inter-cultures, adapting pond creation and fish farming practices to watershed management and topography all could reduce pesticide levels in edible fish and contribute to a better sustainability of the extensive fish farming in pond. PMID:22467231

Developing an approach for simulating and assessing land use changes and their effects on land use patterns and hydrological processes at the watershed level is essential in land use and water resource planning and management. This study provided a novel approach that combines a land use change mode...

Erosion and runoff have been observed to increase following fire. Land managers and Burned Area Emergency Rehabilitation (BAER) teams must be able to estimate these post-fire changes. Studies of post-fire erosion on burned watersheds show that the concentrations of sediment eroded from burned rangel...

A brief overview is given of the philosophy and organization of the Integrated Lake Watershed Acidification Study (ILWAS). These data are used for detailed watershed budgets and to establish a benchmark for future ecological effects studies in the Adirondacks. An intensive, integrated, five-year study of three forested watersheds was established to determine how lake waters become acidified and to quantify the train of events occurring as acid precipitation becomes lake water. The study integrated management questions into the scientific research at the planning stage. The total system was divided into compartments for detailed scientific analysis with a model being developed to reassemble the data from each subsection to represent the overall behavior of the system.

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Mill Creek watershed are coordinated with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. During the FY 2002, trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-stream crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed. Maintenance to the previously built fence was also completed.

A Geographical Information System (GIS) is an invaluable tool in the estimation of land use changes and spatial variability in urban areas. (Non-Point Source (NPS) models provide hypothetical opportunities to assess impacts which storm water management strategies and land use changes have on watersheds by predicting loadings on a watershed scale. This study establishes a methodology for analyzing land use changes and management associated with them by utilizing a GIS analysis of impervious surfaces and AGricultural Non- Point Source (AGNPS) modeling. The GIS analysis of Total Impervious Area (TIA) was used to quantify increases in development and provided land use data for use in AGNPS modeling in a small artificially- delineated urban watershed. AGNPS modeling was executed in several different scenarios to predict changes in NPS loadings associated with increases in TIA and its subsequent management in a small artificially- delineated urban watershed. Data editing, creation and extracting was completed using ArcView (3.2) GeoMedia (6) GIS systems. The GIS analysis quantified the increase in urbanization via TIA within the Bluebonnet Swamp Watershed (BSW) in East Baton Rouge Parish (EBRP), Louisiana. The BSW had significant increases in urbanization in the 8 year time span of 1996 2004 causing and increase in quantity and decrease in quality of subsequent runoff. Datasets made available from the GIS analysis included TIA and the change in percentage from 1996 to 2004. This information is fundamental for the AGNPS model because it was used to calculate TIA percentages within each AGNPS cell. A 30 year daily climate file was used to execute AGNPS in different land use and storm water management scenarios within the 1100 acre BSW. Runoff qualities and quantities were then compared for different periods of 1996 and 2004. Predictions of sediment, erosion and runoff were compared according by scenario year. Management practices were also simulated by changing the Runoff Curve Number (RCN) within AGNPS and their results were also compared. This study provides an aid to planners and managers in estimating increases in urbanization by artificially- delineated watershed. It also in illustrates how to use AGNPS to predict NPS pollution and the influence that change in TIA, land use and storm water management strategies have on sediment loadings, erosion and runoff in a watershed.

Modified Universal Soil Loss Equation (MUSLE) application study is undertaken in order to estimate the sediment yield of the Kengir watershed in Iyvan City, Ilam Province, Iran. The runoff factor of MUSLE is computed using the measured values of runoff and peak rate of runoff at outlet of the watershed. Topographic factor (LS) and crop management factor(C) are determined using geographic information system (GIS) and field-based survey of land use/land cover. The conservation practice factor (P) is obtained from the literature. Sediment yield at the outlet of the study watershed is simulated for six storm events spread over the year 2000 and validated with the measured values. The high coefficient of determination value (0.99) indicates that MUSLE model sediment yield predictions are satisf...

Recent literature on the diffusion of innovations concentrates either specifically on public adoption of policy, where social or environmental conditions are the dependent variables for adoption, or on private adoption of an innovation, where emphasis is placed on the characteristics of the innovation itself. This article uses both the policy diffusion literature and the diffusion of innovation literature to assess watershed management councils' decisions to adopt, or not adopt, scientific models. Watershed management councils are a relevant case study because they possess both public and private attributes. We report on a survey of councils in the United States that was conducted to determine the criteria used when selecting scientific models for studying watershed conditions. We found that specific variables from each body of literature play a role in explaining the choice to adopt scientific models by these quasi-public organizations. The diffusion of innovation literature contributes to an understanding of how organizations select models by confirming the importance of a model's ability to provide better data. Variables from the policy diffusion literature showed that watershed management councils that employ consultants are more likely to use scientific models. We found a gap between those who create scientific models and those who use these models. We recommend shrinking this gap through more communication between these actors and advancing the need for developers to provide more technical assistance.

Trend estimation of climatic characteristics for a watershed is required to determine developing compatible strategies related to design, development, and management of water resources. In this study, the trends of the annual maximum ( T max), minimum ( T min), and mean ( T mean) air temperature; temperature anomaly ( T anomaly); and diurnal temperature range (DTR) time series at 13 meteorological stations located in the Karun-Dez watershed were analyzed using the Mann-Kendall and linear regression trend tests. The pre-whitening method was used to eliminate the influence of serial correlation on the Mann-Kendall test. The result showed increasing trends in the T min, T mean, and T anomaly series at the majority of stations and decreasing trend in the T max and DTR series. A geographical analysis of the trends revealed a broad warming trend in most of the watershed, and the cooling trends were observed only in the southern parts. Furthermore, the geographical pattern of the trends in the T mean and T anomaly series was similar, and the T max data did not show any dominant trend for the whole watershed. This study provides temperature change scenarios that may be used for the design of future water resource projects in the watershed.

One of the main constraints of irrigated agriculture is off-site N pollution due to export of nitrate in irrigation return flows (IRF). Models capable of simulating the growth of crops and the N loads in IRF as affected by irrigation and N fertilization may be valuable tools in watershed studies. The Agricultural Policy Environmental eXtender (APEX) model was used to assess best management practices for reducing off-site N loads in the IRF of three Mediterranean irrigated watersheds (Akarsu in Turkey, La Violada in Spain and Sidi Rached in Algeria). The watersheds (ranging from 4013 to 10,971ha) were monitored along three hydrological years to determine the volume of IRF and the NO3-N concentrations and loads in IRF. APEX was calibrated with the data of the first two years and validated wi...

Nine small (25 ha) and four large (70-135 ha) watersheds were instrumented in 1999 to evaluate the effects of intensive silvicultural practices with best management practices (BMPs) on runoff and stream water quality in the Western Gulf Coastal Plain of East Texas, USA. Two treatments were implemented in 2002: a conventional treatment with clearcutting and herbicide site preparation, and an intensive treatment that added subsoiling, fertilization and a release herbicide application. Watershed effects were compared with results from a previously conducted study on the same watersheds in 1981, in which two combinations of harvesting and mechanical site preparation without BMPs were evaluated. Due to the reduction in evapotranspirational demand, total storm runoff increased on all six treated...

River Francoli is a small river in Catalonia (northeastern Spain) with an average annual low flow (~2m^3/s). The purpose of the River Francoli watershed assessments is to support and inform region-wide planning efforts from the perspective of water protection, climate change and water allocation. In this study, a hydrological model of the Francoli River watershed was developed for use as a tool for watershed planning, water resource assessment, and ultimately, water allocation purposes using hydrological data from 2002 to 2006 inclusive. The modeling package selected for this application is DHI's MIKE BASIN. This model is a strategic scale water resource management simulation model, which includes modeling of both land surface and subsurface hydrological processes. Topographic, land use, h...

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

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe and the Nez Perce National Forest (NPNF) have formed a partnership in completing watershed restoration activities, and through this partnership, more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. Starting in FY 2002, continuing into 2004, trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-stream crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed, and one high priority culvert was replaced in 2004. Maintenance to the previously built fence was also completed.

The Soil and Water Assessment Tool (SWAT) was calibrated for hydrology conditions in an agricultural watershed of Orestimba Creek, California, and applied to simulate fate and transport of two organophosphate pesticides chlorpyrifos and diazinon. The model showed capability in evaluating pesticide fate and transport processes in agricultural fields and instream network. Management-oriented sensitivity analysis was conducted by applied stochastic SWAT simulations for pesticide distribution. Results of sensitivity analysis identified the governing processes in pesticide outputs as surface runoff, soil erosion, and sedimentation in the study area. By incorporating sensitive parameters in pesticide transport simulation, effects of structural best management practices (BMPs) in improving surface water quality were demonstrated by SWAT modeling. This study also recommends conservation practices designed to reduce field yield and in-stream transport capacity of sediment, such as filter strip, grassed waterway, crop residue management, and tailwater pond to be implemented in the Orestimba Creek watershed. - Selected structural BMPs are recommended for reducing loads of OP pesticides.

Problems of unsustainable watershed use in the Mediterranean areas (overgrazing, forest degradation and clearing, soil erosion, fires, etc.) often result from the reduced profitability of traditional land use systems, lack of clearly defined property rights, insufficient enforcement of existing rules, and lack of adequate economic instruments. The paper tries to analyze these problems from two complementary economic perspectives: the first one, based on a Cost-Benefit Analysis approach, highlight the gap between public interest and local private profitability in ordinary watershed management activities through three case studies in Tunisia. Once we have demonstrated that market mechanisms are unable to allocate efficiently watershed resources, we assume a more normative perspective focusing on the implementation of voluntary instruments related to payments for environmental services. Due to the lack of experiences in the Mediterranean basin, we discus the results of a comparison among six case-studies of payments for water provision services in some developing countries underlying the role of transaction costs and social capital in the successful implementation of these new economic instruments for the sustainable management of Mediterranean watershed resources. Key words: cost-benefit analysis, payments for environmental services, Tunisia. (Author) 39 refs.

Exposing headwater streams to direct solar radiation by removing forest cover has the potential to cause drastic changes in streamwater temperature regimes. A study was conducted to evaluate the maximum potential impacts and to evaluate the effectiveness of management practices used to control these detrimental effects. The control watershed approach was utilized. A clearcut-herbicide experiment on a small, headwater stream increased maximum stream temperatures as early as February and as late as November. The average monthly stream temperature increase was 4.4/sup 0/C. Stream temperatures above 21/sup 0/C occurred nearly every day during the summer. Stream temperatures above 25/sup 0/C were recorded as early as May. The highest stream temperature recorded was 32/sup 0/C. On an adjacent forested watershed, stream temperatures rarely exceeded 20/sup 0/C; the highest recorded temperature was 22/sup 0/C. Minimum stream temperatures on the clearcut-herbicided watershed increased an average of 2/sup 0/C during the summer months, but were as much as 3.9/sup 0/C lower during the fall and winter months. Diurnal fluctuations in stream temperature were also increased. Diurnal fluctuations as high as 17/sup 0/C occurred on the cleancut-herbicided watershed compared with only 4/sup 0/C on the forested watershed. On an adjacent commercially clearcut watershed, where a buffer zone was left along the perennial stream channels, only slight changes in stream temperature were observed. The average monthly maximum stream temperature increase was <1/sup 0/C; the highest temperature recorded was 23/sup 0/C. Minimum temperatures remained generally unchanged.

Farmers can generate environmental benefits (improved water quality and fisheries and wildlife habitat), but they may not be able to quantify them. Furthermore, farmers may reduce their incomes from managing lands to produce these positive externalities but receive little monetary compensation in return. This study simulated the relationship between agricultural practices, water quality, fish responses to suspended sediment and farm income within two small watersheds, one of a cool water stream and one of a warm water stream. Using the Agricultural Drainage and Pesticide Transport (ADAPT) model, this study related best management practices (BMPs) to calculated instream suspended sediment concentrations by estimating sediment delivery, runoff, base flow, and streambank erosion to quantify the effects of suspended sediment exposure on fish communities. By implementing selected BMPs in each watershed, annual net farm income declined $18,000 to $28,000 (1 to 3 percent) from previous levels. \\

Contributing to the debate on the causes of Himalayan environmental degradation, the status and management of four watersheds in the Upper Pokhara Valley were studied using information available from land use analysis, household surveys conducted in 1989 and 1992, deliberations held with villagers, and field observations. Accordingly, areas under forests and grazing lands were found being depleted at relatively high rates between 1957 and 1978 due mainly to the government policy of increasing national revenue by expansion of agricultural lands, nationalization of forests, steadily growing population, and dwindling household economy. Despite the steady growth of population, this process had remarkably slackened since 1978, owing primarily to remaining forests being located in very, steep slopes and implementation of the community forestry program. Forests with relatively sparase tree density, however, and grazing lands in the vicinity of settlements have been undergoing degradation due to fuelwood and fodder collection and livestock grazing. In many instances, this is aggravated by weak resource management institutions. Being particularly aware of the economic implication of land degradation, farmers have adopted assorted land management practices. Still a substantial proportion of bari lands in the hill slopes is vulnerable to accelerating degradation, as the arable cropping system is being practiced there as well. The perpetuation of the local subsistence economy is certain to lead, to a further deterioration of the socioeconomic and environmental conditions of watersheds. To facilitate environmental conservation and ecorestructuring for sustainable development, a broad watershed management strategy is outlined with focus on alleviating pressure on natural resources.

The green house gas loading of the atmosphere has been increasing since the mid 19th century which threatens to dramatically change the earth's climate in the 21st Century. Scientific evidences show that earth's global average surface temperature has risen some 0.75°C (1.3°F) since 1850. Third Assessment Report (TAR) from the Intergovernmental Panel on Climate Change (IPCC) concluded that human activities have increased the atmospheric concentration of greenhouse gases (GHGs), which will result in a warming world and other changes in the climate. TAR has projected an increase in globally average surface temperature of 1.4 to 5.8 °C and an increase in precipitation of 5 to 20 % over the period of 1990 to 2100. Assuming a global temperature increase of between 2.8 and 5.2 °C, it was estimated a 7-15% increase in global evaporation and precipitation rates. Global warming and subsequent climate change could raise sea level by several tens of centimeters in the next fifty years. Such a rise may erode beaches, worsen coastal flooding and threaten water quality in estuaries and aquifers. With the climate already changing and further change in climate highly likely to happen, study of impact of climate and the adaptation is a necessary component of any response to climate change. The objective of this study is to analyze the impact of climate change on runoff and sediment delivery in a Great Lake watershed located in Northern Ohio. Maumee River watershed is predominantly an agricultural watershed with an area of 6330 sq mile and drains to Lake Erie. Agricultural area covers about 89.9% of the watershed while wooded area covers 7.3%, 1.2% is urban area and other land uses account for 1.6%. Water Quality Laboratory, Heidelberg College has monitored the watershed for last 25 years. The Soil and Water Assessment Tool (SWAT) model is used for both water quantity and water quality simulations for past and future scenarios. SWAT is a continuous, long-term watershed scale simulation model which operates on a daily time step. The model is physically based, computationally efficient, and capable of assessing the impact of climate and watershed management on water, sediment, and nutrient/chemical yields. SWAT model has been calibrated for flow and sediment yield from 1982 to 2002 for the watershed. The calibrated model will be used to predict future flow and sediment delivery scenarios due to climate change (increase in temperature).

Within the ecosystem services framework, this study explores local population preferences for different land-use management options in the Nacimiento watershed (south-eastern Spain). To this end, we analysed the benefits generated by the watershed through a choice experiment. We selected two ecological (river quality and protected area), three socio-economic (traditional agriculture, ecotourism facilities and wind farms) and one monetary (tax reallocation) attributes associated with various ecosystem services in the area, where changes in land-use are occurring. The data were first analysed using a multinomial logit model. Then, a mixed logit model was used to account for heterogeneity across respondent preferences. Our results indicated that the respondents would support a new management ...

The Journal of Irrigation and Drainage Engineering covers all phases of irrigation, drainage, engineering hydrology, and related water management subjects, such as watershed management, weather modification, water quality, groundwater, and surface water. The journal emphasizes new development...

Mitigating nutrient losses from anthropogenic nonpoint sources is today of particular importance for improving the water quality of numerous freshwater lakes worldwide. Several empirical relationships between land use and in-lake water quality variables have been developed, but they are often weak, which can in part be attributed to lack of detailed information about land use activities or point sources. We examined a comprehensive data set comprising land use data, point-source information, and in-lake water quality for 414 Danish lakes. By excluding point-source-influenced lakes (n = 210), the strength in relationship (R2) between in-lake total nitrogen (TN) and total phosphorus (TP) concentrations and the proportion of agricultural land use in the watershed increased markedly, from 10–12% to 39–42% for deep lakes and from 10–12% to 21–23% for shallow lakes, with the highest increase for TN. Relationships between TP and agricultural land use were even stronger for lakes with rivers in their watershed (55%) compared to lakes without (28%), indicating that rivers mediate a stronger linkage between landscape activity and lake water quality by providing a “delivery” mechanism for excess nutrients in the watershed. When examining the effect of different near-freshwater land zones in contrast to the entire watershed, relationships generally improved with size of zone (25, 50, 100, 200, and 400 m from the edge of lake and streams) but were by far strongest using the entire watershed. The proportion of agricultural land use in the entire watershed was best in explaining lake water quality, both relative to estimated nutrient surplus at agricultural field level and near-lake land use, which somewhat contrasts typical strategies of management policies that mainly target agricultural nutrient applications and implementation of near-water buffer zones. This study suggests that transport mechanisms within the whole catchment are important for the nutrient export to lakes. Hence, the whole watershed should be considered whenmanaging nutrient loadings to lakes, and future policies should ideally target measures that reduce the proportion of cultivated land in the watershed to successfully improve lake water quality. Read More: http://www.esajournals.org/doi/abs/10.1890/11-1831.1

The effects of watershed-scale experimental acidification on the macronutrient content and decomposition of sugar maple (Acer saccharum Marsh) leaves were investigated. Bear Brook Watershed in Maine (BBWM) is a paired forest watershed study where the West Bear (WB) watershed has been treated bi-monthly with 1800eqha-1yr-1 of (NH4)2SO4 since 1989, and the adjacent East Bear (EB) watershed has acted as a reference. Leaf samples collected from the treated WB watershed had significantly higher concentrations of N and P than leaves from the reference EB watershed. Leaves from both watersheds were decomposed for a 10-day laboratory incubation. Extractable total soluble carbon (CTS) content of the leaves decreased following decomposition to a greater extent in WB leaves than in EB leaves. Spectro...

Agricultural tillage influences runoff and infiltration, but consequent effects on watershed hydrology are poorly documented. This study evaluated 25-yr (1971-1995) hydrologic records from four first-order watersheds in Iowa's loess hills. Two watersheds were under conventional tillage, and two were...

The Grays River Watershed and Biological Assessment was funded to address degradation and loss of spawning habitat for chum salmon (Onchorhynchus keta) and fall Chinook salmon (Onchoryhnchus tshawytscha). In 1999, the National Marine Fisheries Service listed lower Columbia River chum salmon as a threatened Evolutionarily Significant Unit (ESU) under the Endangered Species Act of 1973 (ESA). The Grays River watershed is one of two remaining significant chum salmon spawning locations in this ESU. Runs of Grays River chum and Chinook salmon have declined significantly during the past century, largely because of damage to spawning habitat associated with timber harvest and agriculture in the watershed. In addition, approximately 20-25% of the then-remaining chum salmon spawning habitat was lost during a 1999 channel avulsion that destroyed an important artificial spawning channel operated by the Washington Department of Fish and Wildlife (WDFW). Although the lack of stable, high-quality spawning habitat is considered the primary physical limitation on Grays River chum salmon production today, few data are available to guide watershed management and channel restoration activities. The objectives of the Grays River Watershed and Biological Assessment project were to (1) perform a comprehensive watershed and biological analysis, including hydrologic, geomorphic, and ecological assessments; (2) develop a prioritized list of actions that protect and restore critical chum and Chinook salmon spawning habitat in the Grays River based on comprehensive geomorphic, hydrologic, and stream channel assessments; and (3) gain a better understanding of chum and Chinook salmon habitat requirements and survival within the lower Columbia River and the Grays River. The watershed-based approach to river ecosystem restoration relies on a conceptual framework that describes general relationships between natural landscape characteristics, watershed-scale habitat-forming processes, aquatic habitat conditions, and biological integrity. In addition, human land-use impacts are factored into the conceptual model because they can alter habitat quality and can disrupt natural habitat forming processes. In this model (Figure S.1), aquatic habitat--both instream and riparian--is viewed as the link between watershed conditions and biologic responses. Based on this conceptual model, assessment of habitat loss and the resultant declines in salmonid populations can be conducted by relating current and historical (e.g., natural) habitat conditions to salmonid utilization, diversity, and abundance. In addition, assessing disrupted ecosystem functions and processes within the watershed can aid in identifying the causes of habitat change and the associated decline in biological integrity. In this same way, restoration, enhancement, and conservation projects can be identified and prioritized. A watershed assessment is primarily a landscape-scale evaluation of current watershed conditions and the associated hydrogeomorphic riverine processes. The watershed assessment conducted for this project focused on watershed processes that form and maintain salmonid habitat. Landscape metrics describing the level of human alteration of natural ecosystem attributes were used as indicators of water quality, hydrology, channel geomorphology, instream habitat, and biotic integrity. Ecological (watershed) processes are related to and can be predicted based on specific aspects of spatial pattern. This study evaluated the hydrologic regime, sediment delivery regime, and riparian condition of the sub-watersheds that comprise the upper Grays River watershed relative to their natural range of conditions. Analyses relied primarily on available geographic information system (GIS) data describing landscape characteristics such as climate, vegetation type and maturity, geology and soils, topography, land use, and road density. In addition to watershed-scale landscape characteristics, the study area was also evaluated on the riparian scale, with appropriate landscape variables analyzed within riparian buffers around each stream or river channel. Included in the overall watershed assessment are field habitat surveys and analyses of the physical and hydrological characteristics of primary chum and fall Chinook salmon spawning areas and spawning habitat availability and use. This assessment is a significant step in a comprehensive program to ensure the survival and recovery of Columbia River chum salmon in its most productive system and builds on existing recovery planning efforts for these ESA-listed salmonids within the Grays River and the lower Columbia River. This assessment also provides a basis for the recovery of other fish species in the Grays River, including coho salmon, winter steelhead, coastal cutthroat trout, and Pacific lamprey.

Erosion and sediment redistribution play a pivotal role in the terrestrial ecosystem as they directly influence soil functions and water quality. In particular surface waters are threatened by emissions of nutrients and contaminants via erosion. The sustainable management of sediments is thus a key challenge in river basin management. Beside the planning and implementation of mitigation measures typically focusing on small and mesoscale catchments, the knowledge of sediment emissions and associated substances in large drainage basins is of utmost importance for water quality protection of large rivers and the seas. The objective of this study was thus to quantify the sediment input into the large drainage basins of Germany (Rhine, Elbe, Odra, Weser, Ems, Danube) as a basis for nutrient and contaminant emissions via erosion. The sediment input was quantified for all watersheds of Germany and added up along the flow paths of the river systems. Due to the large scale, sediment production within the watersheds was estimated based on the USLE for cultivated land and naturally covered areas and on specific erosion rates for mountainous areas without vegetation cover. To quantify the sediment delivery ratio a model approach was developed using data on calculated sediment production rates and long term sediment loads observed at monitoring stations of 13 watersheds located in different landscape regions of Germany. A variety of morphological parameters and catchment properties such as slope, drainage density, share of morphological sinks, hypsometric integral, flow distance between sediment source areas and the next stream as well as soil and land use properties were tested to explain the variation in the sediment delivery ratios for the 13 watersheds. The sediment input into streams is mainly controlled by the location of sediment source areas and the morphology along the flow pathways to surface waters. Thus, this complex interaction of spatially distributed catchment properties cannot be characterized using only spatially lumped parameters for watersheds located in very different landscape regions. From all parameters tested, the mean slope of the watersheds and the share of arable land located in a distance of 500 m revealed a significant relation to the sediment delivery ratio. Using both parameters the sediment input was quantified for all other watersheds of Germany showing a good agreement with observed long term sediment loads at monitoring stations.

The water quality of discharge from the surface water system is ultimately dictated by land use and climate within the watershed. Water quality has vastly improved from point source reduction measures, yet, non-point source pollutants continue to rise. 30 to 40% of rivers still do not meet water quality standards for reasons that include impact from urban storm water runoff, agricultural and livestock runoff, and loss of wetlands. Regulating non-point source pollutants proves to be difficult since specific dischargers are difficult to identify. However, parameters such as dissolved organic carbon (DOC) limit the amounts of chlorination due to simultaneous disinfection by-product formation. The concept of watershed management has gained much ground over the years as a means to resolve non-point source problems. Under this management scheme stakeholders in a watershed collectively agree to the nature and extent of non-point sources, determine water quality causes using sound scientific approaches, and together develop and implement a corrective plan. However, the ''science'' of watershed management currently has several shortcomings according to a recent National Research Council report. The scientific component of watershed management depends on acquiring knowledge that links water quality sources with geographic regions. However, there is an observational gap in this knowledge. In particular, almost all the water quality data that exists at a utility are of high frequency collected at a single point over a long period of time. Water quality data for utility purposes are rarely collected over an entire watershed. The potential is high, however, for various utilities in a single watershed to share and integrate water quality data, but no regulatory incentives exist at this point. The only other available water quality data originate from special scientific studies. Unfortunately these data rarely have long-term records and are usually tailored to address unrelated research questions. The goal of this research was to investigate whether scientific research tools were available that could provide evidence that links water quality and land type. In particular, could such tools be used on raw water at the treatment point rather than monitoring over a large geographic spanning a watershed. This report summarizes the utility of using isotopic tracers to better understand sources of non-point source pollution and their relation to industry standard water quality measurements. In this study we have found that much of the water quality data generated by utilities is under-interpreted in the context of understanding watershed processes. For example, the City of St. Louis depends solely on the Missouri River for drinking water, but due to large variability in discharge and runoff sources, they are faced with DOC concentrations that vary nearly a factor of three within a single season. The relationship between discharge and concentration has not been constrained. However, we found a linear correlation between the DOC concentration and the fractional amount of downstream discharge (derived from within the State of Missouri). This correlation relates directly to differences in land use and climate between the upstream and downstream portions of the river basin.

Water conservation efforts strive to reduce dependency on imported water. A critical first step in these efforts is evaluating the range of hydrologic inputs and outputs of highly complex urban watersheds. The Ballona Creek Watershed is an ideal location to demonstrate application of a water budget analysis to quantify native and non-native inputs and outputs as well as associated uncertainties. The Ballona Creek Watershed is located within Los Angeles County, the second most populous metropolitan region in the United States. This extensively developed watershed relies heavily on imported water to meet the demands of its 1.2 million residents. Rapid development has led to an increase in impervious land cover, reducing natural infiltration and directing pollutant-loaded urban runoff to the concrete-lined channels which drain to the Santa Monica Bay. Results of the long-term water budget analysis show that the annual runoff ratio exhibits a distinct rising trend through the study period (1938 to 2010) which is indicative of rapid development; however, trends in the last decade have deviated from this pattern, often yielding annual runoff ratios greater than 1. At the monthly time scale, average dry season runoff exceeds precipitation during the June to August period for all decades between the 1940s to 2000s, with the exception of a few anomalous summer storm events. Most of this additional water is attributed to imported water and irrigation excess resulting in dry season runoff and artificial groundwater recharge. However, contributing native water sources also exist. Perennial natural springs were identified through field investigation in the foothills and along faults in the watershed. Summer season flow rates from sampled springs range from 2 to 200 m3/day. Historical evapotranspiration rates are also being investigated using traditional models and a remote-sensing algorithm. Information obtained from this study is being used to inform managers and decision makers on water conservation and stream restoration efforts.

The significance of nutrient inputs at the watershed scale is best expressed in terms of in-stream processes, compared to evaluating simple field measurements of nutrient inputs. Modeling tools are necessary to consider the complexity of river networks in the determination of the sources and processes by which nutrients are transported at the watershed scale. Mediterranean rivers are potentially vulnerable to climate change (decrease in precipitation and increase of extreme events), and identifying and quantifying nutrient pollution sources and their spatial distribution can improve water resource management at the watershed scale. We apply a hybrid process-based and statistical model (SPARROW, spatially referenced regression on watershed attributes) to a largely disturbed Mediterranean wa...

Model calibration and validation are necessary before applying it for scenario assessment and watershed management. This study presented the methodology of evaluating Soil and Water Assessment Tool (SWAT) and tested the feasibility of SWAT on runoff and sediment load simulation in the Zhifanggou watershed located in hilly-gullied region of China. Daily runoff and sediment event data from 1998-2008 were used in this study; data from 1998-2003 were used for calibration and 2004-2008 for validation. The evaluation statistics for the daily runoff simulation showed that the model results were acceptable, but the model underestimated the runoff for high-flow events. For sediment load simulation, the SWAT performed well in capturing the trend of sediment load, while the model tended to underestim...

Climate change dynamics have significant consequences on water resources on a watershed scale. With water becoming scarcer and susceptible to variation, the planning and reallocation decisions in watershed management need to be reviewed. This research focuses on an in-depth understanding of the curr...

14 articles related to watershed management comprise this special advertising section of the Association of Metropolitan Sewerage Agencies. Subtopics include water quality, regulations, US Environmental Protection Agency activities, analysis tools, economics, flooding and erosions, and non-point source pollutions. Articles on arid and coastal are included. Several articles describe municipal watershed programs being planned or in place.

Karst watersheds with significant losing streams represent a particularly vulnerable setting for ground water contamination because of the direct connection to surface water. Management challenges in this type of karst setting are similar to surface watersheds with regard to implementation of best m...

Prediction of water level is an important task for groundwater planning and management when the water balance consistently tends toward negative values. In Maheshwaram watershed situated in the Ranga Reddy District of Andhra Pradesh, groundwater is overexploited, and groundwater resources management requires complete understanding of the dynamic nature of groundwater flow. Yet, the dynamic nature of groundwater flow is continually changing in response to human and climatic stresses, and the groundwater system is too intricate, involving many nonlinear and uncertain factors. Artificial neural network (ANN) models are introduced into groundwater science as a powerful, flexible, statistical modeling technique to address complex pattern recognition problems. This study presents the comparison ...

Groundwater contamination due to infiltration of various contaminants such as nitrate from agricultural practices may be degrading water quality and aquatic habitats. Numerical simulations are especially helpful for investigations of the impact of this contamination while it is challenging to practically model long-term groundwater contaminant loading into streams in agricultural watersheds as a result of limited field data availability, complexity of groundwater systems, uncertainty from different model parameters, and difficulty of boundary approximation. In this study, a number of general system features of watersheds and aquifers are first identified and discussed such as relatively independent water flow systems with certain hydraulic impact from adjacent watersheds, hydraulic and chemical interactions between groundwater and surface water, spatially and temporally varied groundwater recharge rates from precipitation, and seasonal changes of contaminant loading into streams. A comprehensive modeling approach integrating different attributes, including model components, pertinent factors, system statuses, and useful methods and tools, is then proposed to achieve a practical numerical model. A case study is presented in which groundwater flow and nitrate transport and fate are modeled, using the comprehensive GMS modeling package, in the regional aquifers beneath two adjacent agricultural watersheds of the Chester River Basin, Maryland. This was a part of efforts to investigate the eutrophication and water quality of Chesapeake Bay. This model was calibrated, including estimations of variable groundwater recharge rates from rainfall in different zones for different seasons, and validated successfully by implementing the integrated approach in which different types of the field data such as water head and nitrate concentrations, stream fluxes, geographic and geologic data, and precipitation were utilized adequately and integrally. Model simulations predict a long-term groundwater nitrate loading into the streams and Chesapeake Bay from the two watersheds with different patterns of agricultural nitrate applications, considering significant denitrification in aquifer sediments and other riparian-instream nitrate removal processes. It is observed that the integrated modeling approach has capability of accomplishing a valuable complex numerical model for investigations of long-term groundwater contaminant loading into streams in agricultural watersheds for different agricultural contaminant disturbances. As a result, an optimal and integrated ecosystem management pertaining to the concerned watersheds may be facilitated by implementing the established numerical model which accounts for the hydraulic and chemical interactions between groundwater and surface water.

The impacts of watershed urbanization on streams have been studied worldwide, but are rare in China. We examined relationships among watershed land uses and stream physicochemical and biological attributes, impacts of urbanization on overall stream conditions, and the response pattern of macroinvertebrate assemblage metrics to the percent of impervious area (PIA) of watersheds in the middle section of the Qiantang River, Zhejiang Province, China. Environmental variables and benthic macroinvertebrates of 60 stream sites with varied levels of watershed urban land use were sampled in April, 2010. Spearman correlation analysis showed watershed urbanization levels significantly correlated with increased stream depth, width, and values of conductivity, total nitrogen, ammonia, phosphate, calcium...

Qingjiang River, the second largest tributary of the Yangtze River in Hubei Province, has taken on the important tasks for power generation and flood control in Hubei Province. The Qingjiang River watershed has a subtropical monsoon climate and, as a result, has dramatic diversity in its water resources. Recently, global warming and climate change have seriously affected the Qingjiang watershed?s integrated water resources management. In this article, general circulation model (GCM) and watershed hydrological models were applied to analyze the impacts of climate change on future runoff of Qingjiang Watershed. To couple the scale difference between GCM and watershed hydrological models, a statistical downscaling method based on the smooth support vector machine was used to downscale the GCM...

Integrated watershed management (IWM) is an advanced land-management approach that has been widely implemented in Tigray region of northern Ethiopia since 2004. The general aim of this study was to analyze to what extent the IWM approach is effective in curbing land degradation in the fragile drylands of the Enabered watershed in Tigray. This study assessed the impacts of IWM on (1) land-use and land-cover change and (2) the decrease of runoff loss and soil loss due to sheet and rill erosion and gully erosion. The watershed characteristics and implemented IWM measures were mapped in the field. Land use and land cover, runoff, and soil losses were compared before (2004) and after (2009) the IWM interventions. Plantations and exclosures increased significantly at the expense of grazing lands and bushland. Runoff and sheet and rill erosion decreased by 27 and 89 %, respectively, and gully channels were reclaimed. The decrease in sheet and rill erosion resulted from changes in crop cover (48 %) and conservation-practice (29 %) factors, as represented by C and P of the Universal Soil Loss Equation. The results showed that land degradation has been curbed as a result of IWM intervention. A key factor to this success was the effectiveness of the implementation approach for the main IWM components, including the participation of the local community in the form of a contribution of 20 days of free labor. Based on these results, IWM may be implemented in other regions with similar environmental and socioeconomic situations. PMID:23076659

Excessive loads of nutrients transported by tributary rivers have been linked to hypoxia in the Gulf of Mexico. Management efforts to reduce the hypoxic zone in the Gulf of Mexico and improve the water quality of rivers and streams could benefit from targeting nutrient reductions toward watersheds with the highest nutrient yields delivered to sensitive downstream waters. One challenge is that most conventional watershed modeling approaches (e.g., mechanistic models) used in these management decisions do not consider uncertainties in the predictions of nutrient yields and their downstream delivery. The increasing use of parameter estimation procedures to statistically estimate model coefficients, however, allows uncertainties in these predictions to be reliably estimated. Here, we use a robust bootstrapping procedure applied to the results of a previous application of the hybrid statistical/mechanistic watershed model SPARROW (Spatially Referenced Regression On Watershed attributes) to develop a statistically reliable method for identifying “high priority” areas for management, based on a probabilistic ranking of delivered nutrient yields from watersheds throughout a basin. The method is designed to be used by managers to prioritize watersheds where additional stream monitoring and evaluations of nutrient-reduction strategies could be undertaken. Our ranking procedure incorporates information on the confidence intervals of model predictions and the corresponding watershed rankings of the delivered nutrient yields. From this quantified uncertainty, we estimate the probability that individual watersheds are among a collection of watersheds that have the highest delivered nutrient yields. We illustrate the application of the procedure to 818 eight-digit Hydrologic Unit Code watersheds in the Mississippi/Atchafalaya River basin by identifying 150 watersheds having the highest delivered nutrient yields to the Gulf of Mexico. Highest delivered yields were from watersheds in the Central Mississippi, Ohio, and Lower Mississippi River basins. With 90% confidence, only a few watersheds can be reliably placed into the highest 150 category; however, many more watersheds can be removed from consideration as not belonging to the highest 150 category. Results from this ranking procedure provide robust information on watershed nutrient yields that can benefit management efforts to reduce nutrient loadings to downstream coastal waters, such as the Gulf of Mexico, or to local receiving streams and reservoirs.

The Eagle River watershed is located near the destination resort town of Vail, Colorado. The area has a fastgrowing permanent population, and the resort industry is rapidly expanding. A large percentage of the land undergoing development to support that growth overlies the Eagle River watershed valley-fill aquifer (ERWVFA), which likely has a high predisposition to groundwater contamination. As development continues, local organizations need tools to evaluate potential land-development effects on ground- and surface-water resources so that informed land-use and water management decisions can be made. To help develop these tools, the U.S. Geological Survey (USGS), in cooperation with Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority, conducted a study in 2006-2007 of the groundwater quality, age, and probability of contamination in the ERWVFA, north-central Colorado.\\r\

Based on an ongoing qualitative case study in Costa Rica, this article presents the participatory work that the Instituto Costarricense de Electricidad (ICE) is doing with farmers to protect watersheds from erosion and contamination. Specifically, it includes a description of ICE's Watershed Management Agricultural Programme and how farmers participate in it and a qualitative analysis of the kind of learning that participants are experiencing. ICE uses collaborative and hands-on activities to raise awareness and promote alternative environmentally sustainable farming practices and technologies. These activities result in instrumental and communicative learning as found in transformative learning theory. The instrumental learning that occurs includes acquiring skills and information, determining cause-effect relationships, and task-oriented problem solving. The communicative learning that occurs includes understanding values, concepts, and others' points of view. In conclusion, the learning that occurred resulted in transformations in the conditions of life that promoted sustainability. (Contains 6 notes.)

This study evaluated the reduction effect of non-point source pollution by applying best management practices (BMPs) to a 1.21 km2 small agricultural watershed using a SWAT (Soil and Water Assessment Tool) model. Two meter QuickBird land use data were prepared for the watershed. The SWAT was calibrated and validated using daily streamflow and monthly water quality (total phosphorus (TP), total nitrogen (TN), and suspended solids (SS)) records from 1999 to 2000 and from 2001 to 2002. The average Nash and Sutcliffe model efficiency was 0.63 for the streamflow and the coefficients of determination were 0.88, 0.72, and 0.68 for SS, TN, and TP, respectively. Four BMP scenarios viz. the application of vegetation filter strip and riparian buffer system, the regulation of Universal Soil Loss Equation P factor, and the fertilizing control amount for crops were applied and analyzed. PMID:20923092

Conservation practices including agroforestry and grass buffers are believed to reduce nonpoint source pollution (NPSP) from pastured watersheds. Agroforestry, a land management practice that intersperses agricultural crops with trees, has recently received increased attention in the temperate zone due to its environmental and economic benefits. However, studies are limited that have examined buffer effects on the quality of water from grazed pastures. Six treatment areas, two with agroforestry buffers, two with grass buffers, and two control treatments were used to test the hypothesis that agroforestry and grass buffers can be used to effectively reduce NPSP from pastured watersheds. Vegetation in grass buffer and pasture areas includes red clover (Trifolium pretense L.) and lespedeza (Ku...

Human activity is intricately linked to the quality and quantity of water resources. Although many studies have examined water-human interaction, the complexity of such coupled systems is not well understood largely because of gaps in our knowledge of water-cycle processes which are heavily influenced by socio-economic drivers. Considerable research has been performed to develop an understanding of the impact of local land use decisions on field and catchment processes at an annual basis. Still less is known about the impact of economic and environmental outcomes on decision-making processes at the local and national level. Traditional geographic information management systems lack the ability to support the modeling and analysis of complex spatial processes. New frameworks are needed to track, query, and analyze the massive amounts of data generated by ensembles of simulations produced by multiple models that couple socioeconomic and natural system processes. On this context, we propose to develop an Intelligent Digital Watershed (IDW) which fuses emerging concepts of Digital Watershed (DW). DW is a comprehensive characterization of the eco hydrologic systems based on the best available digital data generated by measurements and simulations models. Prototype IDW in the form of a cyber infrastructure based engineered system will facilitate novel insights into human/environment interactions through multi-disciplinary research focused on watershed-related processes at multiple spatio-temporal scales. In ongoing effort, the prototype IDW is applied to Clear Creek watershed, an agricultural dominating catchment in Iowa, to understand water-human processes relevant to management decisions by farmers regarding agro ecosystems. This paper would also lay out the database design that stores metadata about simulation scenarios, scenario inputs and outputs, and connections among these elements- essentially the database. The paper describes the cyber infrastructure and workflows developed for connecting the IDW modeling tools: ABM, Data-Driven Modeling, and SWAT.

Handling produced water in an economical and environmentally sound manner is vital to coalbed methane (CBM) development, which is expected to increase up to 60% in the next 10-15 years as the demand for natural gas increases. Current produced water-handling methods (e.g., shallow reinjection and infiltration impoundments) are too costly when implemented on a well-by-well basis. A watershed-based effluent credit trading approach may be a means of managing produced water at reduced cost while meeting or surpassing water quality regulations. This market-based approach allows for improved water quality management by enabling industrial, agricultural, and municipal discharge facilities to meet water quality permit requirements by purchasing pollutant reduction credits from other entities within the same watershed. An evaluation of this concept was conducted for the Powder River Basin (PRB) of Montana and Wyoming by the Energy & Environmental Research Center (EERC). To conduct this assessment, the EERC collected and evaluated existing water quality information and developed the appropriate tools needed to assess the environmental and economic feasibility of specific trading scenarios. The accomplishments of this study include (1) an exploration of the available PRB water quantity and quality data using advanced statistical techniques, (2) development of an integrated water quality model that predicts the impacts of CBM produced water on stream salinity and sodicity, (3) development of an economic model that estimates costs and benefits from implementing potential trading options, (4) evaluation of hypothetical trading scenarios between select watersheds of the PRB, and (5) communication of the project concept and results to key state and federal agencies, industry representatives, and stakeholders of the PRB. The preliminary results of a basinwide assessment indicate that up to $684 million could be saved basinwide without compromising water quality as a result of implementing a watershed-based credit-trading approach.

Watershed management decision-making requires cooperation and communication between federal, state, and local stakeholders while incorporating the biophysical and socio-economic processes. The public is increasingly taking part in environmental decision and the need for technology transfer from pub...

Best management practices (BMPs) are placed in streams or watersheds to mitigate the effects of hydrological, chemical, or physical stressors resulting from anthropogenic activities. However, assessments of BMP effectiveness rarely consider the effects of BMP implementation on th...

Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...

Exposure to feces in two watersheds with different management histories was assessed by tracking cattle feces bacterial populations using multiple host-specific PCR assays. In addition, environmental factors affecting the occurrence of these markers were identified. Each assay wa...

Watershed and stormwater managers need modeling tools to evaluate how best to address environmental quality restoration and protection needs in urban and developing areas. Significant investments are needed to protect and restore water quality, address total maximum daily loads ...

Watershed and stormwater managers need modeling tools to evaluate how best to address environmental quality restoration and protection needs in urban and developing areas. Significant investments are needed to protect and restore water quality, address total maximum daily loads ...

Conservation practices have been traditionally used to manage soil and water resources to improve agricultural production, and now include methods to reduce the environmental impacts of agriculture on streams and wetlands. These practices have been regularly implemented within agricultural watershed...

Increased timber harvesting in the boreal regions of Quebec may have a significant impact on aquatic ecosystems. Watershed disturbances such as logging increase chemical loading to lakes. Soil in the Canadian Shield readily adsorbs and accumulates mercury (Hg) from atmospheric deposition. Forest watersheds serve as large reservoirs of Hg that shed their metal load when soil and land hydrology are disrupted. This paper presented the results of a study evaluating the impact of logging on periphyton algal biomass and dry mass. The study also evaluated the impact of total mercury (THG) and methylmercury (MeHg) accumulation in the littoral zone of the boreal lakes. A before-after control-impact (BACI) sample design was applied that required data from control and target sites sampled both before and after the disturbances. The study was carried out on 18 boreal lakes located in the Grenville geological province. Eight lakes had their watersheds logged over 15 to 79 per cent of their area. A further 10 lakes were used as control sites to document interannual variations. The project used water quality and physiographic data acquired by research groups within the Sustainable Forest Management Network. Fourteen study lakes were sampled once a year during 2 consecutive ice-free seasons before and after logging, and another 4 lakes were sampled 2 years after logging. Significant decreases in algal biomass and increases in MeHg concentrations in periphyton mats in a majority of the harvested watershed lakes were detected. The increases may have a significant impact on organisms of higher trophic levels as they are at the base of the food web. Results suggested that the observed decrease in periphyton biomass combined with the increase in MeHg accumulation may magnify the impact of logging activities on fish and other aquatic predators. Two years after logging, it was observed that MeHg concentrations were still increasing. It was concluded that further research is needed identify factors that regulate MeHg transport from forested soils to lakes after watershed disturbance. Authorities should seriously scrutinize watershed morphometric characteristics before issuing permits to forestry companies. 50 refs., 5 tabs., 6 figs.

Despite their trophic importance and potential importance as bioindicators of stream condition, benthic algae have not been well studied in California. In particular there are few studies from small streams in the Sierra Nevada. The objective of this study was to determine the standing crop of chlorophyll-a and benthic algal species assemblages present in the small 1st- and 2nd-order streams of the Kings River Experimental Watersheds (KREW, watersheds of Bull, Providence, Duff, and Teakettle Creeks) and determine the associations of these measures with stream habitat. We collected samples of benthic algae from rock substrata in September 2002 (7 sites) and 2005 (the same 7 sites plus 5 additional sites). Habitat and water-quality data were collected concurrently. Chlorophyll-a values ranged from 0.2 to 3.2 mg??m-2. Chlorophyll-a in the Bull Creek watershed was generally lower than in the other watersheds. Benthic algal assemblages were dominated by diatoms and cyanobacteria. We collected 79 taxa of diatoms in 2002 and 126 taxa in 2005. Diatom taxa richness in individual samples ranged from 15 to 47. Nonmetric multidimensional scaling analysis of arcsine square-root transformed proportional abundances of diatoms identified 3 groups of sites. Bull Creek sites were generally different from other sites (group 1), and the sites from Bull Creek were different in 2002 (group 2) and 2005 (group 3). Five taxa appeared to be particularly important in distinguishing groups: Achnanthidium minutissimum, Cocconeis placentula, Eunotia incisa, Eunotia pectinalis var. minor, and Planothidium lanceolatum. Elevation, water temperature, pH, specific conductance, and canopy were habitat variables correlated with the differences in diatom assemblages among sites. Our results provide a valuable baseline for future studies of benthic algae in Sierra Nevada headwater streams and will be particularly important in understanding the effects of different forest restoration management strategies being tested in the KREW project.

Scientific investigations rept.Prepared in cooperation with Boston Coll., Chestnut Hill, MA. Dept. of Geology and Geophysics.The upper Yuba River watershed is a heavily managed basin recovering from hydraulic gold mining that occurred in the mid 1800s to early 1900s. The Upper Yuba River Studies Program (UYRSP), a component of the California Bay-Delta Authority (CBDA) Ecosystem Restoration Program (ERP), is evaluating options for introducing spring-run Chinook salmon and steelhead trout upstream of Englebright Dam, which is located in the foothills of the northwestern Sierra Nevada, California. This report is one product of on-going studies by the U.S. Geological Survey (USGS) (Childs and others, 2003; Flint and others, 2004; Snyder and others, 2004a, 2004b, 2004c; Curtis and others, 2005), which provide a comprehensive analysis of sediment sources, transport, and storage in the upper Yuba River watershed. The USGS is also investigating water quality in the Yuba River watershed and sediment quality in Englebright Lake, with an emphasis on mercury contamination and bioaccumulation (Alpers and others, 2004; Slotten, 2004).

Keywords: Stomatal conductance; Simulation model; Parameter estimation; Transpiration; Thermal remote sensing. 1. Introduction ... numerous sources of uncertainty in P–M models, the ... successfully in numerous forested watershed studies ...

Ecological risk assessment is a scientific tool designed to evaluate the ecological effects of human activities. Historically, risk assessments have been used as a tool to assess risks to human health from environmental exposures to toxic pollutants, or to assess the ecological effects of toxic releases. The middle Snake River has been used as one of five EPA case studies to demonstrate the applicability of risk assessment at the watershed level for assessing the relative effects of multiple stressors on key ecological components of the aquatic ecosystem. The state and federal resource managers and the public identified restoration and protection of native cold water salmonid species and rare and endangered invertebrate species as a management goal. The risk assessment sought to characterize the significance of reduced water flow, sedimentation, and increased nutrients on these ecological components through a process of problem formulation, stressor-effects analysis, and risk characterization. The desired outcome of the assessment is to identify conditions that must be attained to support the management goal as one step in evaluating management options for ecological protection in the watershed.

Land use and land cover are most important in quantifying soil erosion. Based on the C-factor of the popular soil erosion model, Revised Universal Soil Loss Equation (RUSLE) and a scale-pattern-process theory in landscape ecology, we proposed a multi-scale soil loss evaluation index (SL) to evaluate the effects of land use patterns on soil erosion. We examined the advantages and shortcomings of SL for small watershed (SLsw) by comparing to the C-factor used in RUSLE. We used the Yanhe watershed located on China's Loess Plateau as a case study to demonstrate the utilities of SLsw. The SLsw calculation involves the delineations of the drainage network and sub-watershed boundaries, the calculations of soil loss horizontal distance index, the soil loss vertical distance index, slope steepness, rainfall-runoff erosivity, soil erodibility, and cover and management practice. We used several extensions within the geographic information system (GIS), and AVSWAT2000 hydrological model to derive all the required GIS layers. We compared the SLsw with the C-factor to identify spatial patterns to understand the causes for the differences. The SLsw values for the Yanhe watershed are in the range of 0.15 to 0.45, and there are 593 sub-watersheds with SLsw values that are lower than the C-factor values (LOW) and 227 sub-watersheds with SLsw values higher than the C-factor values (HIGH). The HIGH area have greater rainfall-runoff erosivity than LOW area for all land use types. The cultivated land is located on the steeper slope or is closer to the drainage network in the horizontal direction in HIGH area in comparison to LOW area. The results imply that SLsw can be used to identify the effect of land use distribution on soil loss, whereas the C-factor has less power to do it. Both HIGH and LOW areas have similar soil erodibility values for all land use types. The average vertical distances of forest land and sparse forest land to the drainage network are shorter in LOW area than that in HIGH area. Other land use types have shorter average vertical distances in HIGH area than that LOW area. SLsw has advantages over C-factor in its ability to specify the subwatersheds that require the land use patterns optimization by adjusting the locations of land uses to minimize soil loss.

Depending upon how people use land in a watershed, whether it be farming, livestock grazing, timber harvesting, mining, urbanization, or even recreation, all have significant impacts on the water moving through that watershed. This paper will focus on the urban watershed and how stormwater runoff from urbanization affects erosion, sedimentation, and water quality. It also will explore the potential of a watershed as the basis for managing and protecting water resources. Watershed-based management offers a clear look at how land-use changes affect not only water quality but also erosion and sedimentation; in addition, this approach develops preventive strategies to restore those affected water and land resources. The preventive strategies the author uses for this watershed can be applied to other New Mexico urban watersheds. This paper is divided into three parts. The first part shows how past and present land-use activities affect erosion, sedimentation, and water quality in the Bear Canyon arroyo system. The second part provides solutions to the problems of soil erosion and stormwater pollution in the urban areas through government intervention. The third part discusses how Best Management Practices (BMPs) can be used to limit or reduce stormwater pollution in residential and industrial areas.

In order to better understand the implications of acid deposition in watershed systems in the Sierra Nevada, the California Air Resources Board (CARB) initiated an intensive integrated watershed study at Emerald Lake in Sequoia National Park. The comprehensive nature of the data obtained from these studies provided an opportunity to develop a quantitative description of how watershed characteristics and inputs to the watershed influence within-watershed fluxes, chemical composition of streams and lakes, and, therefore, biotic processes. Two different but closely-related modeling approaches were followed. In the first, the emphasis was placed on the development of systems-theoretic models. In the second approach, development of a compartmental model was undertaken. The systems-theoretic effort results in simple time-series models that allow the consideration of the stochastic properties of model errors. The compartmental model (the University of Arizona Alpine Hydrochemical Model (AHM)) is a comprehensive and detailed description of the various interacting physical and chemical processes occurring on the watershed.

Nitrogen mass budgets have been estimated for ten agricultural watersheds located in a range of hydrologic settings in order to understand the factors controlling the fate of nitrogen applied at the surface. The watersheds, study areas of the Agricultural Chemical Sources, Transport and Fate study of the U.S. Geological Survey National Water Quality Assessment Program, are located in Indiana (IN), Iowa (IA), Maryland (MD), Nebraska (NE), Mississippi (MS) and Washington (WA). They range in size from 7 to 1254 km2, with four of the watersheds nested within larger watersheds. Surface water outflow (normalized to watershed area) ranged from 4 to 83 cm/yr. Crops planted include corn, soybean, small grains, rice, cotton, orchards and vegetables. “Surplus nitrogen” was determined for each watershed by subtracting estimates of crop uptake and volatilization from estimates of nitrogen input from atmospheric deposition, plant fixation, and fertilizer and manure applications for the period from 1987 to 2004. This surplus nitrogen is transported though the watershed via surface and subsurface flow paths, while simultaneously undergoing transformations (such as denitrification and in-stream processing) that result in less export of nitrogen from the watershed. Surface-water discharge and concentration data were used to estimate the export of nitrogen from the watersheds (groundwater outflow from the watersheds was minimal). Subtracting nitrogen export from surplus nitrogen provides an estimate of the net amount of nitrogen removal occurring during internal watershed transport. Watershed average nitrogen surplus ranged from 6 to 49 kg-N/ha. The more permeable and/or greater water flux watersheds (MD, NE, and WA) tended to have larger surplus nitrogen, possibly due to less crop uptake caused by greater leaching and runoff of nitrogen. Almost all of the surplus nitrogen in the low permeability (MS) and tile drained watersheds (IA, IN) was exported from the watershed with surface water. In both cases, surplus nitrogen was transported via fast flow paths (surface runoff and tile drainage) that offer little opportunity for nitrogen processing. However, in watersheds having considerable flow through the subsurface, anaerobic conditions in groundwater (NE) or the streambed (MD) led to considerable denitrification before groundwater discharge to the stream, reducing watershed export of nitrogen. Surface-water and groundwater chemistry, principal components analysis, and end-member-mixing analysis are being used to identify and quantify transport pathways and associated nitrogen removal.

Recent scholarship has urged increased attention to how advances in geographical information systems (GIS) technology can more equitably help to bridge gaps between the theory and practice of environmental protection and dispute resolution. This study brings new evidence to burgeoning debates in the Amazon, examining how a United Nations (UN) development initiative developed mapping systems in a shifting political climate for environmental governance while conducting campaigns with peasant miners to address environmental management. Amendments made in 2002 to the Brazilian Forest Code established natural preserves according to the geographic features of watersheds. The laws deter commercial land use on preserves, imposing strict penalties where artisanal mining is widely prevalent as a liv...

Summary The use of distributed parameter models to address water resource management problems has increased in recent years. Calibration is necessary to reduce the uncertainties associated with model input parameters. Manual calibration of a distributed parameter model is a very time consuming effort. Therefore, more attention is given to automated calibration procedures. This paper describes the development and demonstration of such an automated procedure developed for a national/continental scale assessment study called Conservation Effects Assessment Project (CEAP). The automated procedure is developed to calibrate spatial variation of annual average runoff components for each USGS eight-digit watershed of the United States. It uses nine parameters to calibrate water yield, surface runo...

This paper documents the use of simulated Moderate Resolution Imaging Spectroradiometer land use/land cover (MODIS-LULC), NASA-LIS generated precipitation and evapo-transpiration (ET), and Shuttle Radar Topography Mission (SRTM) datasets (in conjunction with standard land use, topographical and meteorological datasets) as input to hydrological models routinely used by the watershed hydrology modeling community. The study is focused in coastal watersheds in the Mississippi Gulf Coast although one of the test cases focuses in an inland watershed located in northeastern State of Mississippi, USA. The decision support tools (DSTs) into which the NASA datasets were assimilated were the Soil Water & Assessment Tool (SWAT) and the Hydrological Simulation Program FORTRAN (HSPF). These DSTs are endorsed by several US government agencies (EPA, FEMA, USGS) for water resources management strategies. These models use physiographic and meteorological data extensively. Precipitation gages and USGS gage stations in the region were used to calibrate several HSPF and SWAT model applications. Land use and topographical datasets were swapped to assess model output sensitivities. NASA-LIS meteorological data were introduced in the calibrated model applications for simulation of watershed hydrology for a time period in which no weather data were available (1997-2006). The performance of the NASA datasets in the context of hydrological modeling was assessed through comparison of measured and model-simulated hydrographs. Overall, NASA datasets were as useful as standard land use, topographical , and meteorological datasets. Moreover, NASA datasets were used for performing analyses that the standard datasets could not made possible, e.g., introduction of land use dynamics into hydrological simulations

The US Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) has been directed to assist local landowners and communities to implement watershed improvement practices. The purpose of this study was to document current conditions in the Rocky River Watershed in North Carolina and the Saluda River Watershed in South Carolina. A variety of watershed assessment tools, including the NRCS Visual Stream Assessment (VSA), Stream Habitat Assessment (SHA), Riparian Vegetation Index (RVI), Index of Biotic Integrity (IBI), and Land Quality Index (LQI) were used on a statistically representative portion of both watersheds. Overall, the SHA, VSA, and RVI rated the watershed's condition as good, whereas the IBI rated them as fair. Correlations between IBI and the other indices were poor, perhaps indicating these indices measure different features within the watersheds. The LQI emphasized the need for better characterization of urban land and riparian corridors. Inclusion of suburban lawns with the urban land indicator improved correlations between IBI and LQI by 20%. This pilot study suggests further scrutiny in applying quantitative stream physical habitat measures to assess watershed conditions. It also indicates additional study of the IBI by NRCS. Resources devoted to statistical design were valuable and should provide the NRCS with a framework for conducting future watershed studies.

The distribution and movement of arsenic was investigated on the Aberjona watershed in eastern Massachusetts for the purpose of identifying where and by what processes present and past human exposures to this element could have occurred. It was found that although most of the arsenic was originally released in the headwaters of the watershed, extensive migration had occurred, and the potential for human exposure existed far from designated hazardous waste sites. Both surface water and groundwater were found to be important transport pathways, arsenic moved between these two media at several locations in the watershed, with hydrology and concomitant redox, sorption, and alkylation processes determining the observed patterns of arsenic movement. These findings demonstrate that risk assessments or remedial investigations restricted to designated sites or properties in a watershed may yield both an inaccurate picture of the overall risks presented by a chemical and a less-than-optimum focus for remedial efforts. Since total recovery of the arsenic on this watershed is probably not feasible, cost-effective management will also depend on an adequate understanding of arsenic biogeochemistry and hydrologic transport processes at the watershed scale. Because the Aberjona Watershed is typical of many urban, industrialized areas, these results suggest that the whole watershed often defines the appropriate unit for investigation of chemical contamination in the environment. 11 refs., 8 figs.

Recent increases in oil prices, a strong national interest in greater energy independence, and a concern for the role of fossil fuels in global climate change, have led to a dramatic expansion in use of alternative renewable energy sources in the U.S. The U.S. government has mandated production of 36 billion gallons of renewable fuels by 2022, of which 16 billion gallons are required to be cellulosic biofuels. Production of cellulosic biomass offers a promising alternative to corn-based systems because large-scale production of corn-based ethanol often requires irrigation and is associated with increased erosion, excess sediment export, and enhanced leaching of nitrogen and phosphorus. Although cultivation of switchgrass using standard agricultural practices is one option being considered for production of cellulosic biomass, intercropping cellulosic biofuel crops within managed forests could provide feedstock without primary land use change or the water quality impacts associated with annual crops. Catchlight Energy LLC is examining the feasibility and sustainability of intercropping switchgrass in loblolly pine plantations in the southeastern U.S. Ongoing research is determining efficient operational techniques and information needed to evaluate effects of these practices on water resources in small watershed-scale (~25 ha) studies. Three sets of four to five sub-watersheds are fully instrumented and currently collecting calibration data in North Carolina, Alabama, and Mississippi. These watershed studies will provide detailed information to understand processes and guide management decisions. However, environmental implications of cellulosic systems need to be examined at a regional scale. We used the Soil Water Assessment Tool (SWAT), a physically-based hydrologic model, to examine water quantity effects of various land use change scenarios ranging from switchgrass intercropping a small percentage of managed pine forest land to conversion of all managed forested land to switchgrass. The regional-scale SWAT model was successfully run and calibrated on the ~ 5 million ha Tombigbee Watershed located in Mississippi and Alabama. Publically available datasets were used as input to the model and for calibration. To improve calibration statistics, five tree age classes (0-4 yr, 4-10 yr, 10-17 yr, 17-24 yr, 24-30 yr) were added to the model to more appropriately represent existing forested systems in the region, which are not included within the standard SWAT set-up. Our results will be essential to public policy makers as they influence and plan for large-scale production of cellulosic biofuels, while sustaining water quality and quantity.

Hydrological flow predictions in ungauged and sparsely gauged watersheds use regionalization or classification of hydrologically similar watersheds to develop empirical relationships between hydrologic, climatic, and watershed variables. The watershed classifications may be based on geographic proximity, regional frameworks such as ecoregions or classification using cluster analysis of watershed descriptors. General approaches used in classifying hydrologically similar watersheds use climatic and watershed variables or statistics of streamflow data. Use of climatic and watershed descriptors requires variable selection to minimize redundancy from a large pool of potential variables. This study compares classification performance of four variable groups to identify homogeneous watersheds in three Mid-Atlantic ecoregions (USA): Appalachian Plateau, Piedmont, and Ridge and Valley. The variable groups included: (1) variables that define watershed geographic proximity; (2) variables that define watershed hypsometry; (3) variables selected using causal selection algorithms; and (4) variables selected using principal component analysis (PCA) and stepwise regression. The classification results were compared to reference watersheds classified as homogeneous using three streamflow indices: Slope of flow duration curve; Baseflow index; and Streamflow elasticity using a similarity index (SI). Classification performance was highest using variables selected by causal algorithms (e.g., HITON-MB method, SI = 0.71 for Appalachian Plateau, SI = 0.90 for Piedmont, and SI = 0.72 for Ridge and Valley) compared to variables selected by stepwise regression (SI = 0.72 for Appalachian Plateau, SI = 0.87 for Piedmont, and SI = 0.64 for Ridge and Valley) and PCA (SI = 0.71 for Appalachian Plateau, SI = 0.76 for Piedmont, and SI = 0.57 for Ridge and Valley).

This report contains all the papers presented at the meeting. There are 25 sessions and one poster session in the document. The Sessions are: (1) Landfill gas/groundwater interactions; (2) Urban solids management; (3) Local issues; (4) Surface water quality studies 1; (5) Reductive treatment of hazardous wastes with zero-valent iron; (6) Water reuse 1; (7) Biosolids management; (8) GIS information systems 1; (9) Drinking water distribution; (10) Anaerobic treatment; (11) Water reuse 2; (12) Municipal wastewater treatment technology; (13) GIS information systems 2; (14) Drinking water treatment 1; (15) Risk-based site remediation; (16) Small urban watersheds; (17) Disinfection; (18) Air pollution control and risk assessment; (19) Drinking water treatment 2; (20) Biological wastewater treatment; (21) Wastewater treatment; (22) Decentralized small-scale alternative wastewater management systems; (23) General environmental issues; (24) Drinking water treatment 3; and (25) Groundwater remediation. Papers have been processed separately for inclusion on the database.

Headwater streams are typically closely connected with the surrounding watershed landscape, making them sensitive to local watershed conditions. Headwater streams of the Kenai Lowlands in Alaska provide important rearing habitat for juvenile salmon and other biota, and understanding the connections between surrounding landscapes and stream conditions will improve management capabilities. We conducted field evaluations of 30 headwater stream sites on the Kenai Lowlands of Alaska, stratified across watersheds and wetland types, and combined these results with GIS analysis of 12 landscape metrics. Flow-weighted slope (FWS), which is an indicator of the combined influence of percentage cover and topographic position of wetlands, was the best predictor of stream chemistry. Our results revealed ...

Summary Watershed models require calibration before they are utilized as a decision-making tool. This paper describes a rigorous sensitivity analysis, automated parameter estimation and evaluation of prediction uncertainty for a Watershed Analysis Risk Management Framework (WARMF) model of the Turkey Creek Watershed. Sensitivity analysis was conducted using UCODE calibration and uncertainty-analysis software. Simulated stream flow is strongly sensitive to 7 of the 20 parameters evaluated: hydraulic conductivity, field capacity, total porosity, precipitation weighting factor, evaporation magnitude, evaporation skewness and snow melting rates; and parameter sensitivity is dependent on site-specific climate and soil conditions. Simulated stream flow matched observed stream flow fairly well wi...

We study modifications to the novel stochastic watershed method for segmentation of digital images. This is a stochastic version of the original watershed method which is repeatedly realized in order to create a probability density function for the segmentation. The study is primarily done on synthe...

Many areas in the US fail to meet water quality standards. Management actions to improve water quality also impact other ecosystem services, both positively and negatively. We developed an integrated approach to analyze how to meet various levels of water quality while maximizing the net benefits of other ecosystem services in an agricultural watershed. We used the SWAT model (Soil and Water Assessment Tool) to predict crop yield, flow, sediment and phosphorus export and the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model to estimate market returns from agriculture production and non-market values from sediment and phosphorus reduction and from carbon sequestration. We applied these models to an agricultural watershed located in South Central Minnesota to find optimal landscape arrangement for a range of water quality goals. Results showed that the current landscape is near the economic optimum and that market returns from agricultural production dominate total economic returns, even when ecosystem services such as water quality and carbon sequestration are valued. We find that land use patterns that achieve 50% reductions in sediment and phosphorus result in significant annual losses in economic returns (averaging approximately 300/ha and 250/ha for sediment and phosphorus, respectively). When including non-market valuation of ecosystem services, 50% reductions in sediment and phosphorus result in declines in total watershed value an average of about 220/ha and 180/ha for sediment and phosphorus, respectively. However, compared to the current landscape, we show that marginal water quality improvements (10-15% reductions in sediment and phosphorus) could be achieved with no net loss in economic returns. Further, when ecosystem service valuation is included, reductions in sediment and phosphorus on the order of 15-20%, respectively, could be achieved with no net loss of total value. Landscape changes to achieve sediment and phosphorus reductions on the order of 25-50% generally involve shifting poor-yielding or highly-eroding portions of the landscape away from conventional crops to perennial crops such as switchgrass or native prairie grass. These perennial crops reduced nonpoint source pollution through direct as well as indirect effects. Indirect benefits arose from increased evapotranspiration which reduced both stream flow and sediment or phosphorus losses from failing streambanks and eroding ravines (important pollution sources in the study watershed). Results from this study demonstrate that alternative, rather than conventional, conservation practices are needed to achieve water quality goals. Additionally, these results suggest that reducing water yield can help reduce pollution from agricultural watersheds.

Increasing quantity and decreasing quality of urban stormwater threatens biodiversity in local streams and reservoirs, jeopardizes water supplies, and ultimately contributes to estuarine eutrophication. To estimate the effects that present and alternative landscaping practices and land use patterns may have on urban stormwater quantity and quality, simulations of existing land use/land cover using the Regional Hydro-Ecologic Simulation System (RHESSys), a process-based surface hydrology and biogeochemistry model, were developed for watersheds in Baltimore, MD (as part of the Baltimore Ecosystem Study (BES) NSF Long-Term Ecological Research (LTER) site) and Durham, NC (as part of the NSF Urban Long-Term Research Area (ULTRA) program). The influence of land use patterns and landscaping practices on nutrient export in urban watersheds has been explored as part of the BES; this work has focused on improving our understanding of how residential landscaping practices (i.e. lawn fertilization rates) vary across land use and socioeconomic gradients. Elsewhere, others have explored the political ecology of residential landscaping practices - seeking to understand the economic, political, and cultural influences on the practice of high-input residential turf-grass management. Going forward, my research will synthesize and extend this prior work. Rather than pre-supposing predominant residential land use patterns and landscaping practices (i.e. lower-density periphery development incorporating high-input turf landscapes) alternate land use and landscaping scenarios (e.g. higher-density/transit-oriented development, rain gardens, vegetable gardens, native plant/xeriscaping) will be developed through interviews/focus groups with stakeholders (citizens, public officials, developers, non-profits). These scenarios will then be applied to the RHESSys models already developed for catchments in Baltimore and Durham. The modeled scenario results will be used to identify alternate land use patterns and landscaping practices that would: (1) help to reduce non-point sources of nutrient pollution in urban watersheds; and (2) be likely to gain public support. This research will inform sustainable development policy while furthering interdisciplinary research in the fields of planning and water resource management.

Small experimental watersheds in the eastern United States, which define practical ecosystems, are used to study and evaluate (1) the impact of anthropogenic emissions on individual ecosystem processes and (2) the integrated response of the total system. The watershed approach to...

Large and powerful storm systems moved through the Pacific Northwest during the wet season of 1995-96, triggering widespread flooding, mass erosion, and, possibly altering salmon habitats in affected watersheds. This project study was initiated to assess whether watershed conditions are causing damage, triggered by storm events, to salmon habitat on public lands in the Snake River basin.

Natural resource professionals are increasingly faced with the challenges of cultivating community-based support for wetland ecosystem restoration. While extensive research efforts have been directed toward understanding the biophysical dimensions of wetland conservation, the literature provides less guidance on how to successfully integrate community stakeholders into restoration planning. Therefore, this study explores the social construction of wetlands locally, and community members’ perceptions of the wetland restoration project in the Cache River Watershed of southern Illinois, where public and private agencies have partnered together to implement a large-scale wetlands restoration project. Findings illustrate that the wetlands hold diverse and significant meanings to community members and that community members’ criteria for project success may vary from those identified by project managers. The case study provides managers with strategies for building community commitment such as engaging local citizens in project planning, minimizing local burdens, maximizing local benefits, and reducing uncertainty.

Opus (not an acronym) is a computer model for the transport of material in soil and surface water. The model is a simulation tool for studying the potential pollution from various agricultural management practices. It simulates water movement that results from rainfall and other weather inputs and that is affected by soil, crop, topography, and many types of management actions and water use influencing the surface condition. Opus includes models for the growth of plants; development of cover, water use; uptake of nutrients; cycling of soil nitrogen, phosphorus, and carbon, transport of adsorbed pesticide and nutrients; interaction of surface water and soil water; runoff; and erosion. This tool allows the user to choose between (1) detailed simulation involving data on the time-intensity pattern of rainfall and (2) a more lumped approach using either recorded daily rainfall or stochastically generated rainfall. To illustrate its use, Opus is applied to a set of rather comprehensive data from a watershed study in Watkinsville, GA.

Increases in the frequency, duration, and severity of regional drought pose major threats to the health and integrity of downstream ecosystems. During 2007–2008, the U.S. southeast experienced one of the most severe droughts on record. Drought and water withdrawals in the upstream watershed led to decreased freshwater input to Apalachicola Bay, Florida, an estuary that is home to a diversity of commercially and ecologically important organisms. This study applied a combination of laboratory experiments and field observations to investigate the effects of reduced freshwater input on Apalachicola oysters. Oysters suffered significant disease-related mortality under high-salinity, drought conditions, particularly during the warm summer months. Mortality was size-specific, with large oysters of commercially harvestable size being more susceptible than small oysters. A potential salinity threshold was revealed between 17 and 25 ppt, where small oysters began to suffer mortality, and large oysters exhibited an increase in mortality. These findings have important implications for watershed management, because upstream freshwater releases could be carefully timed and allocated during stressful periods of the summer to reduce disease-related oyster mortality. Integrated, forward-looking water management is needed, particularly under future scenarios of climate change and human population growth, to sustain the valuable ecosystem services on which humans depend. PMID:22435367

Habitat loss is a major reason for the decline of grassland birds in North America. Five habitats (pastures, hayfields, rowcrop fields, small-grain fields, Conservation Reserve Program fields) compose most of the habitat used by grassland birds in the Midwest United States. Growing and harvesting switchgrass (Panicum virgatum) as a biomass fuel would create another habitat for grassland birds. Bird abundance information from studies conducted in Iowa and adjacent states and land-use data for the Rathbun Lake Watershed in southern Iowa were used in a Geographic Information System to model the potential effects on bird abundances of converting rowcrop fields to biomass production. Abundances of bird species that are management priorities increased in both biomass scenarios. Common yellowthroat (Geothlypis trichas) abundance in the watershed also increased greatly in both scenarios. Other species (e.g., homed lark [Eremophila alpestris], killdeer [Charadrius vociferous]) were more abundant in the existing land use than in the biomass scenarios, and conversion of fields from rowcrop to biomass production could be detrimental to these species. In general, biomass fields will provide habitat for grassland birds that are management priorities, but future monitoring of birds in such fields is needed as conversion of rowcrop fields to biomass production continues. ?? 2002 Elsevier Science Ltd. All rights reserved.

Based on results of the Second National Climate Assessment reported in 2009, the U.S. Global Change Research Program projects temperatures in southern Texas will increase 5 to 8° F by the end of the 21st century, with larger changes occurring under scenarios of higher greenhouse gas emissions. Temperature increases in summer are projected to be larger than in winter. Although drier conditions are expected in the region, sea-level rise, extreme rainfall events, and associated storm surges are projected to occur more frequently because of the likely increase in intensity of hurricanes and tropical storms in the Gulf of Mexico. The range of possible responses to climate change is attributable to a combination of characteristics at global, regional, and local scales. The risk of flooding and catastrophic infrastructure damage due to global climate phenomena has been incorporated into local climate adaptation plans for many low-lying areas and communities in the Gulf Coast region of southern Texas. However, because this region is dominated by irrigated agriculture and the population is projected to double by 2050, it is important to examine how climate change will affect water resources and environmental quality. The purpose of this study is to investigate the potential hydrologic and water quality impacts of projected climate change, land use change, and population change scenarios in the headwaters of the Arroyo Colorado. The results of this work will provide content for a web-based, collaborative geospatial decision support system being developed to support environmental management in the Arroyo Colorado Watershed. Presently, land use in the Arroyo Colorado Watershed is more than 50 percent agricultural and almost 25 percent residential with varying levels of urbanization. As a result, flow in the Arroyo Colorado is sustained primarily by discharge from municipal wastewater treatment facilities, irrigation return flows, and urban storm runoff. In this study, streamflow and nutrient loading simulations for the Arroyo Colorado Watershed are based on the application of the Soil and Water Assessment Tool (SWAT) model driven by projected future climatic conditions generated from five global circulation models under three greenhouse gas emission scenarios. Land use change data are incorporated based on various remote sensing earth observation products including NASA's Moderate Resolution Imaging Spectroradiometer datasets and Landsat images in the multiagency National Land Cover Database. Population change and urbanization are considered in terms of changes in permitted wastewater treatment discharges. The findings of this study indicate that hydrological models like SWAT are useful tools for evaluating the watershed impacts from global climate change scenarios. In developing climate adaption plans, such models should include significant interactions among various local water management systems driven by population growth and urbanization in communities, and site-specific agricultural water use.

Distributed soil moisture information at the watershed scale would be useful for such critical applications as regional resource management during times of drought or flooding, crop irrigation scheduling and pest management, and determining mobility with lightweight vehicles. At this scale, the des...

As described in its Highlands Action Program, the Canaan Valley Institute (CVI) partnered with the US EPA to develop a watershed assessment and management tool that allows managers to evaluate riparian restoration actions to improve instream habitat quality and aquatic community ...

The value of watershed-scale, water quality models to ecosystem management is increasingly evident as more programs adopt these tools to help assess the effectiveness of different management scenarios on the environment. The USDA-Conservation Effects Assessment Project (CEAP) is one such program whi...

In Brazil, water management has been both sectored and centralized. In the 1990s, a series of state level reforms granted substantial participation to civil society and water users' organizations by incorporating Integrated Water Resourse Management principles and Watershed Committees as its guideli...

Model-based predictions of the impact of land management practices on nutrient loading require measured nutrient flux data for model calibration and evaluation. Consequently, uncertainties in the monitoring data resulting from sample collection and load estimation methods influence the calibration, and thus, the parameter settings that affect the modeling results. To investigate this influence, we compared three different time-based sampling strategies and four different load estimation methods for model calibration and compared the results. For our study, we used the river basin model Soil and Water Assessment Tool on the intensively managed loess-dominated Parthe watershed (315 km2) in Central Germany. The results show that nitrate?N load estimations differ considerably depending on samp...

Sr isotope data from soils, water, and atmospheric inputs in a small tropical granitoid watershed in the Luquillo Mountains of Puerto Rico constrain soil mineral development, weathering fluxes, and atmospheric deposition. This study provides new information on pedogenic processes and geochemical fluxes that is not apparent in watershed mass balances based on major elements alone. 87Sr/86Sr data reveal that Saharan mineral aerosol dust contributes significantly to atmospheric inputs. Watershed-scale Sr isotope mass balance calculations indicate that the dust deposition flux for the watershed is 2100+-700mgcm-2ka-1. Nd isotope analyses of soil and saprolite samples provide independent evidence for the presence of Saharan dust in the regolith. Watershed-scale Sr isotope mass balance calculati...

San Francisco Bay is facing a legacy of polychlorinated biphenyls (PCBs) spread widely across the land surface of the watershed, mixed deep into the sediment of the Bay, and contaminating the Bay food web to a degree that poses health risks to humans and wildlife. In response to this persistent problem, water quality managers are establishing a PCB total maximum daily load (TMDL) and implementation plan to accelerate the recovery of the Bay from decades of PCB contamination. This article provides a review of progress made over the past 15 years in managing PCBs and understanding their sources, pathways, fate, and effects in the Bay, and highlights remaining information needs that should be addressed in the next 10 years. The phaseout of PCBs during the 1970s and the 1979 federal ban on sale and production led to gradual declines from the 1970s to the present. However, 25 years after the ban, PCB concentrations in some Bay sport fish today are still more than ten times higher than the threshold of concern for human health. Without further management action it appears that the general recovery of the Bay from PCB contamination will take many more decades. PCB concentrations in sport fish were, along with mercury, a primary cause of a consumption advisory for the Bay and the consequent classification of the Bay as an impaired water body. Several sources of information indicate that PCB concentrations in the Bay may also be high enough to adversely affect wildlife, including rare and endangered species. The greater than 90% reduction in food web contamination needed to meet the targets for protection of human health would likely also generally eliminate risks to wildlife. PCB contamination in the Bay is primarily associated with industrial areas along the shoreline and in local watersheds. Strong spatial gradients in PCB concentrations persist decades after the release of these chemicals to Bay Area waterways. Through the TMDL process, attention is being more sharply focused on the PCB sources that are controllable and contributing most to PCB impairment in the Bay. Urban runoff from local watersheds is a particularly significant pathway for PCB entry into the Bay. Significant loads also enter the Bay through Delta outflow (riverine input). Recent studies have shown that erosion of buried sediment is occurring in large regions of the Bay, posing a significant problem with respect to recovery of the Bay from PCB contamination because the sediments being eroded and remobilized are from relatively contaminated buried sediment deposits. In-Bay contaminated sites are likely also a major contributor of PCBs to the Bay food web. Dredged material disposal, wastewater effluent, and atmospheric deposition are relatively minor pathways for PCB loading to the Bay. Priority information needs at present relate to understanding the sources, magnitude of loads, and effectiveness of management options for urban runoff; the regional influence of in-Bay contaminated sites; remobilization of PCBs from buried sediment; historic and present trends; in situ degradation rates of PCBs; reliable recovery forecasts under different management scenarios; the spatial distribution of PCBs in soils and sediments; and the biological effects of PCBs in interaction with other stressors. The slow release of pollutants from the watershed and the slow response of the Bay to changes in inputs combine to make this ecosystem very slow to recover from pollution of the watershed. The history of PCB contamination in the Bay underscores the importance of preventing persistent, particle-associated pollutants from entering this sensitive ecosystem. PMID:17451673

The effects of riparian vegetation on the reduction of agricultural nitrogen export to streams have been well described experimentally, but a clear understanding of process-level hydrological and biogeochemical controls can be difficult to ascertain from data alone. We apply a new model, Visualizing Ecosystems for Land Management Assessments (VELMA), to further elucidate how riparian forest buffers reduce stream inputs of dissolved nitrogen in runoff from upland agricultural practices in an intensively studied catchment in the Rhode River Watershed along the western shore of Chesapeake Bay, USA. VELMA is a spatially distributed eco-hydrology model that links hydrological and biogeochemical processes within watersheds. Simulated and observed daily stream flow and export of nitrogen (ammonium, nitrate and organic nitrogen) are in generally good agreement for the period of record (2000-2003) for which complete daily stream flow and chemistry data were available. A sensitivity analysis of the model demonstrates its potential for isolating specific hydrologic and biogeochemical controls on attenuation of dissolved nitrogen within the riparian forest zone, and for identifying upland and riparian best management practices concerning water quality. The results indicate that subsurface flow pathways, forest buffer design (width), and management (stand age) have a significant influence on stream nitrogen loads. However, forest buffers alone may be insufficient for achieving water quality standards, particularly where upland fertilization rates approach those often used for intensive agriculture. These insights include a quantitative description of the trade-off between agronomic production and nitrogen export to surface waters, and the relative importance of denitrification in reducing nitrogen export under different upland and riparian management scenarios.

In this study, we investigated use of microcosms to supplement field studies for establishing the size of wetlands required to mitigate nitrate pollution in agricultural watersheds. Wetlands investigated in this study were located in San Joaquin Valley (California, USA) and demonstrated mean nitrate-nitrogen mass removal efficiencies ranging between 10 and 34%. Mean areal nitrate removal rates (J) ranged from 142 to 380 mg-N m(-2) d(-1). First-order rate constants determined from field data had a high variance, with confidence intervals greater than 57% of mean values. Sediments and rooted plants from one site were placed in a flow-through microcosm and measurements of nitrate removal kinetics were made and compared with field results. The apparent half-saturation constant (K(m)) and maximum removal rate (J(max)) for nitrate-nitrogen were 43.8 mg/L and 4.11 g m(-2) d(-1) in the microcosm. The first-order rate constant from the microcosm (10.4 cm d(-1)) was in close agreement with the value for the field site (11.9 cm d(-1)) and had a confidence interval of less than 16%. Using this improved first-order rate constant, it was determined that between 1.3 and 3.6% of the land in the watershed should be managed as mitigation wetland, with the area required dependent on the level of nitrate reduction desired and how closely the wetland design approximates plug-flow. PMID:23128619

This report summarizes, for the Water Year 1990 (October 1989-- September 1990), the dynamic hydrologic data collected on the Whiteoak Creek (WOC) Watershed's surface and subsurface flow systems. These systems affect the quality or quantity of surface water and groundwater. The collection of hydrologic data is one component of numerous, ongoing Oak Ridge National Laboratory (ORNL) environmental studies and monitoring programs and is intended to 1. characterize the quantity and quality of water in the flow system, 2. plan and assess remedial action activities, and 3. provide long-term availability of data and assure quality. Characterizing the hydrology of the WOC watershed provides a better understanding of the processes which drive contaminant transport in the watershed. Identifying of spatial and temporal trends in hydrologic parameters and mechanisms that affect the movement of contaminants supports the development of interim corrective measures and remedial restoration alternatives. Hydrologic monitoring supports long-term assessment of the effectiveness of remedial actions in limiting the transport of contaminants across Waste Area Grouping boundaries and ultimately to the off-site environment. The majority of the data summarized in this report are available from the Remedial Action Programs Data and Information Management System data base. Surface water data available within the WOC flow system include discharge and runoff, surface water quality, radiological and chemical contamination of sediments, and descriptions of the outfalls to the WOC flow system. Climatological data available for the Oak Ridge area include precipitation, temperature, humidity, wind speed, and wind direction. Information on groundwater levels, aquifer characteristics, and groundwater quality are presented. Anomalies in the data and problems with monitoring and accuracy are discussed. 58 refs., 54 figs., 15 tabs.

Ungaged watersheds are commonly found in the arid southwest United States. Models are the only practicable method available to water resource managers, earth scientists, and civil engineers for estimating stormwater runoff volumes and flowrates. Significant design decisions are thus based on synthetic hydrographs calculated from coarse-resolution surveys, from which hydraulic properties are obtained. These synthetic hydrographs are often calculated using methods developed for other areas of the country with entirely different environments and landuses that may not be entirely applicable to the arid southwest. This study seeks to examine the use of pedo-transfer functions and soil hydrology principles to determine a more physically-based approach for obtaining soil hydraulic properties and antecedent moisture content (AMC). A multi-modeling platform approach was developed that uses site-specific soil hydraulic and physical data, evaluates them through a regression model, predicts the AMC for a specific set of meteorological conditions, and then predicts stormwater runoff volumes and flowrates. The modeling software packages used for this platform are Rosetta, HYDRUS-1D, and FLO-2D, respectively, all of which are publicly available. The approaches were tied together using Matlab. All data were geospatially rectified and assigned with specific geomorphic surfaces, accounting for spatial variability. Temporal variability of water content is then examined using atmospheric demand and soil properties. These different AMC values are surrogates for successive storm intervals of 1, 5, 10, and 30 days, and used in FLO-2D, a physically-based hydraulic model, which solves full dynamic wave equations for surface runoff. The overall approach was tested on a meso-scale watershed in the Mojave Desert to evaluate the watershed response for design storm frequencies of 2-, 10-, 25-, 50-, and 100-year return periods. The results show that this multi-platform approach can efficiently provide rapid, cost-effective predictions of surface runoff using site-specific field data and physically-based models that is more reflective of the actual site.

The Fort Cobb Reservoir Watershed (FCRW) (830 km2) is a watershed within the HELP Washita Basin, located in Caddo and Washita Counties, OK. It is also a benchmark watershed under USDA's Conservation Effects Assessment Project, a national project to quantify environmental effects of USDA and other conservation programs. Population in south-western Oklahoma, in which FCRW is located, is sparse and decreasing. Agricultural focuses on commodity production (beef, wheat, and row crops) with high costs and low margins. Surface and groundwater resources supply public, domestic, and irrigation water. Fort Cobb Reservoir and contributing stream segments are listed on the Oklahoma 303(d) list as not meeting water quality standards based on sedimentation, trophic level of the lake associated with phosphorus loads, and nitrogen in some stream segments in some seasons. Preliminary results from a rapid geomorphic assessment results indicated that unstable stream channels dominate the stream networks and make a significant but unknown contribution to suspended-sediment loadings. Impairment of the lake for municipal water supply, recreation, and fish and wildlife are important factors in local economies. The Thika River Watershed (TRW) (867 km2) is located in central Kenya. Population in TRW is high and increasing, which has led to a poor land-population ratio with population densities ranging from 250 people/km2 to over 500 people/km2. The poor land-population ratio has resulted in land sub-division, fragmentation, over- cultivation, overgrazing, and deforestation which have serious implications on soil erosion, which poses a threat to both agricultural production and downstream reservoirs. Agricultural focuses mainly on subsistence and some cash crops (dairy cattle, corn, beans, coffee, floriculture and pineapple) farming. Surface and groundwater resources supply domestic, public, and hydroelectric power generation water. Thika River supplies 80% of the water for the city of Nairobi. A dam was constructed in 1994 with a water reservoir of 70 million m3. Thika River also supplies water to Masinga Reservoir to supply the seven forks dams, which together supply 75% of the nation's electricity. The quantity of water in rivers and reservoirs is decreased due to sedimentation while water quality is degraded by sediments, and sediment-borne nutrients and pesticides. The focus of this pilot twinning project is watershed erosion and reservoir sedimentation assessment. This will be accomplished by (1) a rapid watershed/catchment erosion assessment using ground based measurements and remote sensing/GIS techniques, 2) use of Acoustic Profiling Systems (APS) for reservoir sedimentation measurement studies, and 3) advanced water quality modeling using the soil and water assessment tool (SWAT) model. Data acquired will be used for sediment transport modeling to1) determine sediment "hot spots" and management practices that will minimize sediments into reservoirs in order to 2) maintain the reservoirs on which many farmers depend for their livelihood and a cleaner environment. This project will provide an opportunity for 1) sharing knowledge and experience among the stakeholders, 2) building capacity through formal and informal education opportunities through reciprocal hosting of decision makers and water experts, and 3) technology transfer of pilot results with recommended management practices to reduce reservoir sedimentation rates.

This surface water protection plan (plan) provides an overview of the management efforts implemented at Lawrence Livermore National Laboratory (LLNL) that support a watershed approach to protect surface water. This plan fulfills a requirement in the Department of Energy (DOE) Order 450.1A to demonstrate a watershed approach for surface water protection that protects the environment and public health. This plan describes the use of a watershed approach within which the Laboratory's current surface water management and protections efforts have been structured and coordinated. With more than 800 million acres of land in the U.S. under federal management and stewardship, a unified approach across agencies provides enhanced resource protection and cost-effectiveness. The DOE adopted, along with other federal agencies, the Unified Federal Policy for a Watershed Approach to Federal Land and Resource Management (UFP) with a goal to protect water quality and aquatic ecosystems on federal lands. This policy intends to prevent and/or reduce water pollution from federal activities while fostering a cost-effective watershed approach to federal land and resource management. The UFP also intends to enhance the implementation of existing laws (e.g., the Clean Water Act [CWA] and National Environmental Policy Act [NEPA]) and regulations. In addition, this provides an opportunity for the federal government to serve as a model for water quality stewardship using a watershed approach for federal land and resource activities that potentially impact surface water and its uses. As a federal land manager, the Laboratory is responsible for a small but important part of those 800 million acres of land. Diverse land uses are required to support the Laboratory's mission and provide an appropriate work environment for its staff. The Laboratory comprises two sites: its main site in Livermore, California, and the Experimental Test Site (Site 300), near Tracy, California. The main site is largely developed yet its surface water system encompasses two arroyos, an engineered detention basin (Lake Haussmann), storm channels, and wetlands. Conversely, the more rural Site 300 includes approximately 7,000 acres of largely undeveloped land with many natural tributaries, riparian habitats, and wetland areas. These wetlands include vernal pools, perennial seeps, and emergent wetlands. The watersheds within which the Laboratory's sites lie provide local and community ecological functions and services which require protection. These functions and services include water supply, flood attenuation, groundwater recharge, water quality improvement, wildlife and aquatic habitats, erosion control, and (downstream) recreational opportunities. The Laboratory employs a watershed approach to protect these surface water systems. The intent of this approach, presented in this document, is to provide an integrated effort to eliminate or minimize any adverse environmental impacts of the Laboratory's operations and enhance the attributes of these surface water systems, as possible and when reasonable, to protect their value to the community and watershed. The Laboratory's watershed approach to surface water protection will use the U.S. Environmental Protection Agency's Watershed Framework and guiding principles of geographic focus, scientifically based management and partnerships1 as a foundation. While the Laboratory's unique site characteristics result in objectives and priorities that may differ from other industrial sites, these underlying guiding principles provide a structure for surface water protection to ensure the Laboratory's role in environmental stewardship and as a community partner in watershed protection. The approach includes pollution prevention, continual environmental improvement, and supporting, as possible, community objectives (e.g., protection of the San Francisco Bay watershed).

An investigation of the water quality in an under-populated watershed was conducted over a 15-year period in which data was collected at weekly intervals. The purposes of this study were to analyze the long-term trends in water quality and to evaluate the relationship between the water quality and precipitation. Concentrations of total phosphorus (T-P), chemical oxygen demand (COD), and suspended solids (SS) reached remarkably high values under heavy precipitation conditions, and these concentrations increased exponentially with the amount of precipitation. Over the course of this study, the population, number of factories, animals (cow and pig), and area of agricultural land exhibited clearly decreasing trends, while steady progress in domestic wastewater treatment was realized. However, no clear decrease in the parameters of water quality was observed, and some nitrogen, phosphorus, and COD concentrations increased even though no significant change in precipitation occurred. A possible hypothesis explaining this lack of a clear decrease in water quality is that specific pollutant outflows from forests and agricultural lands may have increased in recent years. This is because poorly managed forests and agricultural lands in the under-populated watershed have adversely affected the water quality of the rivers.   

The first anthology of analysis and reflection on CMC and the then-young Internet from perspectives rooted in both philosophy and religious studies. Several of the chapters remain watershed publications in the genre of Internet Studies.

A study of selected water-quality and macroinvertebrate community data was conducted at 10 stream sites in the Seacoast region of New Hampshire to determine if a relation is present between stream quality and the extent of urbanization in a watershed. Watersheds with similar characteristics, but varying in their degree of urban development, were studied. The percent of impervious surface, the percent of urban land use in a watershed, and the percent of urban land use in two types of stream buffers were compared and correlated with stream-quality variables. \\r\

Background Mongolia’s riverine landscape is divided into three watersheds, differing in extent of permafrost, amount of precipitation and in hydrological connectivity between sub-drainages. In order to assess the vulnerability of macroinvertebrate communities to ongoing climate change, we consider the taxonomic and functional structures of stream communities in two major watersheds: The Central Asian Internal Watershed (CAIW) and the Arctic Ocean Watershed (AOW), together covering 86.1% of Mongolia’s surface area. We assess the consequences of the hydrological connectivity between sub-drainages on the nestedness and distinctness of the stream communities. And accordingly, we discuss the expected biotic changes to occur in each watershed as a consequence of climate change. Results Gamma and beta diversities were higher in the CAIW than the AOW. High community nestedness was also found in the CAIW along with a higher heterogeneity of macroinvertebrate assemblage structure. Assemblages characteristic of cold headwater streams in the CAIW, were typical of the drainages of the Altai Mountain range. Macroinvertebrate guilds of the CAIW streams exhibited traits reflecting a high stability and low resilience capacity for eutrophication. In contrast, the community of the AOW had lower nestedness and a combination of traits reflecting higher stability and a better resilience capacity to disturbances. Conclusion Higher distinctness of stream communities is due to lower connectivity between the drainages. This was the case of the stream macroinvertebrate communities of the two major Mongolian watersheds, where connectivity of streams between sub-drainages is an important element structuring their communities. Considering differences in the communities’ guild structure, hydrological connectivity and different magnitudes of upcoming impacts of climate change between the two watersheds, respective stream communities will be affected differently. The hitherto different communities will witness an increasing differentiation and divergent adaptations for the upcoming changes. Accordingly, in an increasing awareness to protect Mongolia’s nature, our results encourage adapting conservation planning and management strategies specifically by watershed. PMID:12950629

The Passaic River is located in the New Jersey-New York metropolitan area. This river has been heavily polluted by dioxins, PAHs, PCBs and heavy metals due to agricultural, industrial activities, and urbanization. Contaminated sediments in the Passaic River have received considerable attention because contaminants (metals, PCBs. PAHs, dioxins) in the sediments have potential to release into the aquatic system and air through diffusion and/or volatilization, causing human health hazards. Identification of high concentration areas of these Contaminants in the river-estuarine system is critical to the Passaic River environmental restoration and watershed protection. In this study, we analyzed portion of 10 years (1991-2000) data using Geographic Information Systems (GIS) as a tool to study the distributions of contaminants in the sediments. The results from this study provide important information for developing environmental management strategies for the lower Passaic River system.

Agricultural watersheds are coupled human-natural systems where the land use decisions of human agents (farmers) affect surface water quality, and in turn, are affected by the weather and yields. The reliable modeling of such systems requires an approach that considers both the human and natural aspects. Agent-based modeling (ABM), representing the human aspect, coupled with hydrologic modeling, representing the natural aspect, is one such approach. ABM is a relatively new modeling paradigm that formulates the system from the perspectives of the individual agents, i.e., each agent is modeled as a discrete autonomous entity with distinct goals and actions. The primary objective of this study is to demonstrate the applicability of this approach to agricultural watershed management. This is done using a semi-hypothetical case study of farmers in the Salt Creek watershed in East-Central Illinois under the influence markets for carbon and second-generation bioenergy crop (specifically, miscanthus). An agent-based model of the system is developed and linked to a hydrologic model of the watershed. The former is based on fundamental economic and mathematical programming principles, while the latter is based on the Soil and Water Assessment Tool (SWAT). Carbon and second-generation bioenergy crop markets are of interest here due to climate change and energy independence concerns. The agent-based model is applied to fifty hypothetical heterogeneous farmers. The farmers' decisions depend on their perceptions of future conditions. Those perceptions are updated, according to a pre-defined algorithm, as the farmers make new observations of prices, costs, yields and the weather with time. The perceptions are also updated as the farmers interact with each other as they share new information on initially unfamiliar activities (e.g., carbon trading, miscanthus cultivation). The updating algorithm is set differently for different farmers such that each is unique in his processing of new information. The results provide insights on how differences in the way farmers learn and adapt affect their forecasts of the future, and hence, decisions. Farmers who are interacting, less risk averse, quick to adjust their expectations with new observations, and slow to reduce their forecast confidence when there are unexpected changes are more likely to practice conservation tillage (farmers may claim carbon credits for sale when practicing conservation tillage), and switch from conventional crops to miscanthus. The results, though empirically untested, appear plausible and consistent with general behavior by farmers. All this demonstrates the ability and potential of ABM to capture, at least partially, the complexities of human decision-making.

Agricultural water management (AWM) is the adaptation strategy for increasing agricultural production through enhancing water resources availability while maintaining ecosystem services. This study characterizes groundwater hydrology in the Kothapally agricultural watershed, in hard rock Deccan plateau area in India and assesses the impact of AWM interventions on groundwater recharge using a calibrated and validated hydrological model, SWAT, in combination with observed water table data in 62 geo-referenced open wells. Kothapally receives, on average, 750 mm rainfall (nearly 90% of annual rainfall) during the monsoon season (June to October). Water balance showed that 72% of total rainfall was converted as evapotranspiration (ET), 16% was stored in aquifer, and 8% exported as runoff from the watershed boundary with AWM interventions. Nearly 60% of the runoff harvested by AWM interventions recharged shallow aquifers and rest of the 40% increased ET. Water harvesting structures (WHS) contributed 2.5 m additional head in open wells, whereas hydraulic head under natural condition was 3.5 m, resulting in total 6 m rise in water table during the monsoon. At the field scale, WHSs recharged open wells at a 200 to 400 m spatial scale. PMID:23106818

The ecosystem approach to water resource management is deceptively simple: one must recognize the interrelationships among water, land, air, and all living things and undertake resource planning in such a way that the integrity of the natural system is preserved. Significant features of the ecosystem approach include its watershed boundaries, its holistic orientation, and its assumption that humans should be viewed as part of, rather than apart from, the natural system. A theme of environmental ethics and education underlies the approach. Although it seems straightforward, the ecosystem approach has important implications for water management. In 1985, the International Joint Commission challenged government agencies to utilize the ecosystem approach to develop Remedial Action Plans to rehabilitate forty-two hotspots across the Great Lakes Basin. This initiative represented a first effort to implement the ecosystem approach in the Great Lakes. The research questions were: what does ecosystem management mean in the context of the RAP process, and how can one increase the likelihood of successful implementation of ecosystem management plans The research proposition suggests that there are three preconditions to ecosystem management: participation; decision making; and legitimacy. Comparative case studies of Green Bay, Wisconsin; Saginaw Bay, Michigan; and Hamilton Harbor, Ontario were undertaken. Thirty-five RAP participants were chosen for on-site indepth interviews. Data were arrayed by respondent, question, and case, and were analyzed for content.

Understanding the best way to allocate limited resources is a constant challenge for water quality improvement efforts. The synoptic approach is a tool for geographic prioritization of these efforts. It uses a benefit-cost framework to calculate indices for functional criteria in subunits (watersheds, counties) of a region and then rank the subunits. The synoptic approach was specifically designed to incorporate best professional judgment in cases where information and resources are limited. To date, the synoptic approach has been applied primarily to local or regional wetland restoration prioritization projects. The goal of this work was to develop a synoptic model for prioritizing watersheds within which suites of agricultural best management practices (BMPs) can be implemented to reduce sediment load at the watershed outlets. The model ranks candidate watersheds within an ecoregion or river basin so that BMP implementation within the highest ranked watersheds will result in the most sediment load reduction per conservation dollar invested. The model can be applied anywhere and at many scales provided that the selected suite of BMPs is appropriate for the evaluation area's biophysical and climatic conditions. The model was specifically developed as a tool for prioritizing BMP implementation efforts in ecoregions containing watersheds associated with the USDA-NRCS conservation effects assessment project (CEAP). This paper presents the testing of the model in the little river experimental watershed (LREW) which is located near Tifton, Georgia, USA and is the CEAP watershed representing the southeastern coastal plain. The application of the model to the LREW demonstrated that the model represents the physical drivers of erosion and sediment loading well. The application also showed that the model is quite responsive to social and economic drivers and is, therefore, best applied at a scale large enough to ensure differences in social and economic drivers across the candidate watersheds. The prioritization model will be used for planning purposes. Its results are visualized as maps which enable resource managers to identify watersheds within which BMP implementation would result in the most water quality improvement per conservation dollar invested. PMID:23142919

Stormwater ponds are increasingly common aquatic habitats whose biotic communities are largely unexplored. As anthropogenic development continues to alter the landscape, watershed land use is gaining recognition for its potential to predict species compositions in aquatic systems. This study reports species composition of five aquatic hemipteran families (Notonectidae, Corixidae, Belostomatidae, Nepidae, Pleidae) in 28 permanent, artificial stormwater ponds in watersheds with different land covers and associated contaminant input. We hypothesized that land cover variables would be significant drivers of aquatic hemipteran community structure in ponds, and that ponds with a high percentage of agricultural and lawn cover in the watershed would be characterized by the absence of species intol...

Nutrient loading from beef pastures located within the northern Lake Okeechobee watershed in Florida, has been identified as a source of phosphorus contributing to the accelerated eutrophication of the lake. Since 1989 within the watershed, 557 agricultural drainage sites, mainly beef pasture, have been monitored for compliance under a regulatory program. Of those sites, 154 were actively monitored for phosphorus concentrations from October 1, 1998, to September 30, 1999. Of these 154 sites, 77 were considered to be out of compliance (OOC). An OOC site is defined as having runoff with a 12-month average phosphorus concentration exceeding the permitted discharge limit. The average annual phosphorous load from the 77 OOC sites for an eight-year study period from October 1, 1991, to September 30, 1999, was estimated using measured concentration values and simulated runoff obtained from an agricultural nonpoint source pollution model, CREAMS-WT. The 77 OOC sites produced an estimated average annual 46 metric tonnes of phosphorus load, of which an estimated 22 tonnes of phosphorus reached Lake Okeechobee on an average annual basis. The remaining estimated average annual 24 tonnes of phosphorus load was retained by streams and wetlands in the discharge transport system between the sites and the lake. The estimated average annual load reaching Lake Okeechobee from the OOC sites represented 11 percent of the phosphorus load above a five-year average annual target load for the lake. However, the OOC site drainage areas represented only 3 percent of the northern watershed that drains into the lake. Of the 77 OOC sites, 12 sites had an average annual phosphorus loading rate equal to or greater than 3.0 kg/ha and were placed on the priority list for the Critical Restoration Project in the Lake Okeechobee watershed. To estimate the possible phosphorus load reductions from the 77 sites, two scenarios were modeled. The first scenario reduced phosphorus concentrations in runoff to the permitted discharge limits under the Lake Okeechobee regulatory program. The second scenario changed current land uses to native rangeland with an estimated annual offsite total phosphorus areal loading rate of 0.114 kg/ha. These two scenarios are hypothetical with assumed concentration values and loading rate. Model results showed that the first management scenario reduced the average annual phosphorus load to the lake by an estimated 15 tonnes. The second scenario reduced the average annual phosphorus load to the lake by an estimated 21 tonnes.

This study, conducted in Nyanza Gulf of Lake Victoria, assessed ecological succession and dynamic status of water hyacinth. Results show that water hyacinth is the genesis of macrophyte succession. On establishment, water hyacinth mats are first invaded by native emergent macrophytes, Ipomoea aquatica Forsk., and Enydra fluctuans Lour., during early stages of succession. This is followed by hippo grass Vossia cuspidata (Roxb.) Griff. in mid- and late stages whose population peaks during climax stages of succession with concomitant decrease in water hyacinth biomass. Hippo grass depends on water hyacinth for buoyancy, anchorage, and nutrients. The study concludes that macrophyte succession alters aquatic biodiversity and that, since water hyacinth infestation and attendant succession are a symptom of broader watershed management and pollution problems, aquatic macrophyte control should include reduction of nutrient loads and implementing multifaceted approach that incorporates biological agents, mechanical/manual control with utilization of harvested weed for cottage industry by local communities. PMID:22619574

Soil organic carbon is a soil property of central importance for soil quality and the global carbon cycle. Studies specifically aimed at the relationship between the spatial variation of soil organic carbon and environmental factors are few. In this paper, a typical small watershed named Tongshuang in the black soil region of northeast China, which was subjected to drastic erosion before 1980 and was managed subtly after 1980, was chosen as a study area. Classical statistic and geostatistic analysis methods, in combination with a geographic information system (GIS), were used to quantitatively research the spatial variation characteristics of the soil organic carbon and their relation to the topographic factors and land use. The data on the soil organic carbon, topographic factors, and lan...

The Moderate Resolution Imaging Spectroradiometer (MODIS) provides new opportunities for characterizing land-cover (LC) to support monitoring and assessment studies at watershed, regional and global scales. This research evaluated the potential for using the MODIS Normalized Diff...

The application of conceptual hydrological models in ungauged watersheds (watersheds without streamflow data) or watersheds with limited flow data to generate runoff records for planning and design purposes, is stimulating. In this type of applications, the hydrological models are calibrated to gauged watersheds of a homogeneous region, and regional equations explaining the variation of the model parameters with physiographic factors are developed or the average model parameter values are used in the application of the model in ungauged watersheds of the region. In this study, the U.B.C. watershed model was used to simulate the runoff from mountainous watersheds. The model conceptualizes the watershed as a number of elevation bands and distributes the runoff into four runoff components namely, surface runoff, medium runoff, slow groundwater runoff and the very slow groundwater runoff, with a soil moisture control mechanism separately for rainfall, snowmelt and glacier melt using the linear storage technique. Total runoff is calculated by the summation of the runoff components for all elevation bands. In this study, two methods are proposed. The first method uses the regionally averaged U.B.C. model parameters for water allocation and flow routing, and the precipitation gradients estimated from annual meteorological data as well as knowledge on the distribution of orographic precipitation. The second method links the regional U.B.C. watershed model with ANNs and can be used in watersheds with limited discharge measurements. In this method, the various runoff components were used as input parameters to a feed-forward (back propagation) artificial neural network in order to represent the physical processes of the hydrological cycle. The structure of ANN was designed in order to avoid over-fitting and was followed specific criteria, as proposed in the international literature. The two proposed methods have been applied to four mountainous watersheds in various climatological regions. The results showed that the first method simulates satisfactorily the observed discharge assuming that the basins are ungauged. If limited streamflow data are available, the simulation of the runoff is highly improved using the second method that couples the U.B.C. watershed model with ANNs.

The Phase II studies of the R4D Program on stream and watershed ecology reflect the accomplishments and accumulation of baseline information obtained during the past studies. Although our rough estimates indicate that nitrogen inputs to the watershed ba lance losses, the carbon fluxes suggest that they are not in equilibrium and that there is a net loss of carbon from the tundra ecosystem through respiration and transport out of the watershed via the stream system. Radiocarbon profiles of soil sections coupled with mass transport calculations revealed that peat accumulation has essentially ceased in the R4D watershed and appears to be in ablative loss. Thus the carbon flux measurements provide validation tests for the PLANTGRO and GAS-HYDRO models of the PHASE II studies. These findings are also important in the context of global CO[sub 2] increases from positive feedback mechanisms in peatlands associated with climatic warming in the subarctic regions.

Two watershed modeling tools are currently being applied in the Chesapeake Bay watershed to support the management of nutrient loading to tidal waters. SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were developed by the United States Geological Survey to relate sources of nutrients (total nitrogen and total phosphorus) to stream loads throughout the 164,000 km2 watershed. In a separate effort, the Chesapeake Bay Program has developed a watershed model using the Hydrologic Simulation Program FORTRAN (HSPF) modeling framework. These two modeling approaches are quite different in structure. The SPARROW models are statistically based and are spatially explicit. In contrast, the HSPF model is deterministic and is temporally explicit. Both modeling efforts provide information about nutrient loading in the Chesapeake Bay watershed and their combined use is now being explored. SPARROW and HSPF provide different perspectives on nutrient loading that may be used as complementary information to support management decisions. SPARROW models provide a framework for utilizing data that are available in greater spatial detail than can be utilized by current versions of HSPF. SPARROW models also provide empirical information on those sources or watershed characteristics that best explain the spatial variation in nutrient loading. The HSPF model includes components that account for management actions and can be used to evaluate potential land-use or nutrient-management scenarios. Preliminary comparisons indicate that the models provide similar predictions of total nitrogen and total phosphorus loads and yields, particularly for drainage basins larger than 2,000 km2. Nutrient budgets for the two types of models also are similar, although there are some differences in the percentage of the budgets attributed to certain sources. The Chesapeake Bay Program is now evaluating the two modeling approaches for joint use in an allocation and targeting process that is being developed to guide nutrient management actions designed to achieve new tidal water-quality criteria. Nutrient-load allocations are being established for watersheds and jurisdictions through mass-balance principles using the HSPF model. The SPARROW models offer supplementary information that enhances the spatial scale of the targeting process. HSPF model units are approximately 2,000 km2 on average. SPARROW model units average approximately 120 km2 and nest within most HSPF model units, so that they can provide supplementary information on source locations and nutrient budgets for smaller streams.

NRMRL-CIN-1496A Rochon*, G., Szlag*, D., Daniel*, F.B., and Chifos**, C. Remote Sensing Applications for Sustainable Watershed Management and Food Security. Proceedings of the 21st European Association of Remote Sensing Laboratories Symposium, Marne-La-Valle, France, 5/14-16/200...

The hydrological simulation on watersheds is one of the most important tools for water resources management due to possibility of flow regime prediction. Grande River Basin is located in south of Minas Gerais State, and the Rio Grande is the main tributary of basin which has 2080 km2 draining into t...

Oct 4, 2012 ... Land Stewardship in the 21st Century: The Contributions of ... to restoring watershed lands previously degraded by excessive soil ... This challenge is intimately related to the proper management of land, water, and vegetation resources. ... resources, conservation, sustainable development, sustainable use ...

Research on switchgrass (Panicum virgatum L.) as a biomass energy crop is conducted at several USDA-ARS facilities across the USA. At the USDA-ARS Pasture Systems and Watershed Management Research Unit in University Park, Pennsylvania, research on biomass energy focuses on cropping systems, environm...

The research presented here is a continuation of work designed to further the science of available and developing online toxicity monitors(OTMs) and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system. Source waters o...

The research presented here was designed to further the science of available and developing continuous, automated water quality monitors and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system (WQEWS). Source waters ...

The degradation of running water resources is at least partly due to a lack of understanding of the physical and biological dynamics of stream and river ecosystems and to the lack of a comprehensive, integrated approach to watershed management. The report outlines such an approac...

The Soil and Water Assessment Tool (SWAT) was used to simulate stream flow and predict the impact of different agricultural management practices on atrazine concentrations in the Cedar Creek Experimental Watershed (CCEW) within the St. Joseph River Basin in northeastern Indiana. The model calibratio...

Computer based hydrologic and water quality models have proven to be useful tools for examining alternative management scenarios and their impact on the environment. This examination can be an important component of watershed-scale evaluations. The Soil and Water Assessment Tool (SWAT), is a water...

Soil physical properties are needed to understand and manage natural systems spanning an extremely wide range of scales. Much of soil data are obtained from small soil samples and cores, monoliths, or small field plots, yet the goal is to reconstruct soil physical properties across fields, watershed...

Sep 6, 2012 ... models to improve management of natural resources. Forrest holds B.S. ..... Nearshore Stormwater Runoff and Water Quality in the Great Lakes. - Monitoring ... Potential Impacts of Urban Development on Big Creek Watershed and .... Prepare for a sustainable transition to the partner/user at end of project ...

Effective management of riparian areas in watersheds requires that reach-scale knowlege of riparian functioning be carefully "scaled up" to provide models for entire stream networks. Weller et al. (1998: Ecological Applications 8, 1156-1169) describe a useful heuristic model for...

Lateral redistribution of soil and associated soil organic matter (SOM) by soil erosion imposes significant controls on SOM dynamics within the eroding watershed, and the overall carbon (C) sequestration potential of the terrestrial biosphere. For sediments exported from eroding watersheds, biochemical composition is a function of SOM in the eroding slope profiles, the type of erosion, duration of transport, and the intensity of decomposition that occurs during transport. Eroded SOM stability, including its molecular architecture and associations with soil minerals, influences complex decomposition dynamics involving microbial activity and abiotic factors during transit and after deposition. Sediment traps located at the point where the first-order stream leaves the watershed provide insight into the material removed by these nearly ephemeral streams before the sediment passes into a larger adjacent watershed. This study investigates the variability in amount and composition of SOM eroded from eight first-order watersheds in the mixed-conifer zone of the Sierra National Forest in the Kings River Experimental Watershed. These watersheds range in size from 48.7 to 650 ha, and have predominately western aspects and granitic bedrock. We are determining the interannual variation in the biochemical composition and stability of SOM of the annual sediment load, and how it relates to the composition of the upslope soil in the watershed. Previous work indicates that the dry weight of sediment transported by the streams may vary by more than two orders of magnitude between years and between watersheds (when normalized to kg/ha; Eagan et al. 2004). Our preliminary results show that the carbon to nitrogen (C:N) ratio of the sediment is less variable between years and watersheds, and is similar to the C:N ratio of surface soils from upslope positions. High concentrations of particulate organic matter in the sediment contribute to higher C concentrations in the sediments than in mineral soils in the source watersheds. In this presentation we will show how amount of C and N, and biochemical composition of SOM change during transport of the sediments, and as a function of climate and watershed size.

In the past 30?years, the Lis river basin has been subjected to constant ecological disasters mainly due to piggery untreated wastewater discharges. The aim of this study was to evaluate the effect of existing domestic, agricultural, and industrial activities on the water quality, and to propose a watershed plan to protect and manage surface water resources within the Lis river basin. For this purpose, 16 monitoring stations have been strategically selected along the Lis river stretch and its main tributaries to evaluate the water quality in six different sampling periods (2003?2006). All samples were characterized in terms of organic material, nutrients, chlorophyll, and pathogenic bacteria. Generally, the Lis river presents poor water quality, according to environmental quality standards...

This paper explores the significance of the impacts that changing agricultural and land management policies can have on catchment hydrology. The effects on the hydrological regimes of the land use change resulting from these policies climatic variability can be difficult to disentangle. However, by defining the key periods when various policies had most effect, the individual hydrological responses of the different phases have been separated on an annual and seasonal time scale by analysing time trend and step changes. A case study of the Drentsche Aa watershed in the Netherlands since 1954 revealed that a phase of canalisation (1959-65) greatly reduced peak and base flows as well as number of peak days. A particularly dramatic effect was achieved in 1965 when a flow diversion 'cut-off' wa...

In the last few years "D. I. A. F." (Department of Agriculture and Forestry Engineering of Florence University), has been testing the effectiveness of soil bioengineering techniques in Central America. The focus of the present study was to find out which native plants were most suited for soil bioengineering purposes, particularly in the realization of riverbank protection in Nicaragua. Furthermore, we have also been aiming at economic efficiency. These techniques are appropriate for sustainable watershed management especially in underdeveloped countries. Concerning the plants to be used we experimented four native species. Gliricidia Sepium, Cordia dentata and Jatropha curcas are suitable for soil bioengineering more than Bursera Simaruba. Economically speaking, the sustainability of such interventions in underdeveloped countries, has been shown by the evaluation of the cost of riverbank protection using vegetated crib-walls in Nicaragua compared to the cost in different contexts.

Historical spawning grounds for sea lampreys (Petromyzon marinus L.) in most Portuguese river basins are becoming inaccessible due to the construction of impassable dams and/or weirs. Studies like the one described in this paper are particularly important in areas like the Vouga river basin, where there is a considerable fishing effort from both professional fishermen and poachers. In fact, for management and conservation purposes, it is important to clarify several aspects of the sea lamprey spawning run in this particular watershed. Therefore, a total of 30 radio tagged, migrating sea lampreys were released in the River Vouga and some of its main tributaries during 2004 and 2005. Results from the tracking sessions were used to determine the effect of poaching on the spawners? population ...

Brooks, Robert T. and Elizabeth A. Colburn, 2011. Extent and Channel Morphology of Unmapped Headwater Stream Segments of the Quabbin Watershed, Massachusetts. Journal of the American Water Resources Association (JAWRA) 47(1):158-168. DOI: 10.1111/j.1752-1688.2010.00499.x Abstract:- Effective regulatory protection and management of headwater resources depend on consistent and accurate identification and delineation of stream occurrence. Published maps and digital resources fail to represent the true occurrence and extent of headwater streams. This study assessed the accuracy of mapped origins of -blue-line- streams depicted on U.S. Geological Survey topographic maps, and, if present, the morphological characteristics of unmapped stream segments. We identified 170 mapped stream origins on th...

Limited data on microbial partitioning between the freely suspended and particulate attached phases during transport along overland flow pathways have resulted in high uncertainty in bacterial fate and transport models and the application of these models to watershed management plans. The objectives of this study were to examine differences in attachment between E. coli and enterococci in runoff from plots with highly and sparsely vegetated grassland; investigate relations between flow regime, total suspended solids, and E. coli and enterococci attachment; and identify the particle size categories to which the attached cells were associated. Two rainfall simulations were conducted on large field plots 3?m wide by 18.3?m long with highly and both highly and sparsely vegetated covers and tre...

In the past 30 years, the Lis river basin has been subjected to constant ecological disasters mainly due to piggery untreated wastewater discharges. The aim of this study was to evaluate the effect of existing domestic, agricultural, and industrial activities on the water quality, and to propose a watershed plan to protect and manage surface water resources within the Lis river basin. For this purpose, 16 monitoring stations have been strategically selected along the Lis river stretch and its main tributaries to evaluate the water quality in six different sampling periods (2003?2006). All samples were characterized in terms of organic material, nutrients, chlorophyll, and pathogenic bacteria. Generally, the Lis river presents poor water quality, according to environmental quality standards...

Excessive soil loss during heavy rainfall results in serious turbid water problem in the reservoir. For the purpose of efficient turbid water management in the upland area of the Imha watershed in Korea, this study applied SWAT (Soil and Water Assessment Tools) for assessment of the soil erosion and attempted to evaluate the impact of GIS data on model response to test the model efficiency. First, the outputs of runoff and suspended sediment were investigated corresponding to the various DEM grid sizes (i.e., 30, 60, 90, 120, and 150 m). Further analysis was based on the 8 different scenarios combining with different scales of land use (i.e., 1:25,000 and 1:50,000) and soil type maps (i.e., 1:50,000 and 1:250,000) associated with two different DEM grid sizes. Statistical analysis of the si...

The Oregon Department of Environmental Quality monitors contaminants in fish and sediment. Total mercury was analyzed in fish tissue taken from ten water bodies in 1993 and 1994. Mercury was measured in bass (Micropterus salmoides, M. dolomieui), salmonids (Salmo trutta, Oncorhynchus mykiss, O. clarki) and catfish (Ictalurus punctatus, I. nebulosus) in support of health department consumption advisories. Elevated mercury concentrations above the EPA screening value of 0.6 mg/kg wet were found in fish from watersheds with cinnabar geology or historical mining activity. Established bioaccumulation correlations between mercury and species, age, and length were also observed. Results from East Lake, a popular recreational fishery that had not previously been studied, were found to have fish mercury concentrations approaching 3.0 mg/kg wet. Regulatory and fish management issues will also be presented.

Soil erosion by water can generate serious damages in mountainous ecosystems by the irreversible loss of soil productivity and the degradation of surface water quality. A substantial impact on the quantity of erosion and the amount of transported soil has the local land management. The application of best management practices in regions affected by high soil erosion is the major goal of conservation planning. Management practices include tillage operations and crop cultivation on farmland, but also landscape structuring by field margins, forest patches and riparian areas. Developing proper management strategies for a certain area require careful planning, because they are often associated with high costs and use restrictions for the local people. Different potential control measures are not only strongly variable in their effectiveness, but in certain cases they can even produce higher erosion rates. Therefore effective conservation planning requires individual treatments depending on the local conditions, and it should consider all important factors controlling the impact of each management measure. Objective of this work is to derive possible management measures for mountainous farmland areas in the watershed of the Soyang Lake in South Korea, which are characterized by intense agriculture and heavy monsoonal rain events during the summer months. The complex topography and heterogeneous soil and land use conditions of those areas play a primary role in soil erosion processes and require special consideration for developing conservation measures. The complexity of factors governing erosion processes and the difficulties of evaluating erosion control measures are described on the basis of recent studies focusing on local farmland management and its effect on erosion in this region. We present the types of data bases, which are needed to develop erosion control measures and show different methods, which can be applied to obtain those information. Possible strategies and procedures for the planning of best management practices in this region are given, which can help to develop a more sustainable and environmentally sound agriculture.

Expansion of agricultural at the cost of forested land is a common cause of watershed degradation in the mountain zones of developing countries. Many studies have been conducted to demonstrate land use changes in such regions. However, current knowledge regarding the changes, driving forces and implications of such change within the context of watershed development is limited. This study analyses changes in spatial patterns of agricultural land use and their consequences for watershed degradation during the 1976?2000 period along an altitude gradient in a watershed in Nepal, by means of remote sensing, GIS and the universal soil loss equation. Estimated soil loss ranged from 589 to 620?t?ha?1?y?1, while areas of extreme hazard severity (>100?t?ha?1) increased from 9 to 14.5% from 1990 to 2...

Research in the Adirondacks suggests that watershed dynamics are the key to a lake's vulnerability to acidification. The Electric Power Research Institute's Integrated Lake-Watershed Acidification Study (ILWAS) produced a computer model that successfully integrated the physical and chemical factors that determine these dynamics. The research required an unprecedented level of awareness of how watersheds work and how rain, soil, forests, and rocks interact. One outcome of the field and laboratory studies was the finding that some soils act as buffers, taking certain ions out of the water, while some added ions. While the ability of the watershed as a whole to neutralize acid is the main determinant of a lake's vulnerability, seasonal changes demonstrate that time is a factor. The model is in demand to test water in other locations and to explore buffering agents. 2 figures.

The Maple Creek watershed covers a 955-square-kilometer area in eastern Nebraska, which is a region dominated by agricultural land use. The Maple Creek watershed is one of seven areas currently included in a nationwide study of the sources, transport, and fate of water and chemicals in agricultural watersheds. This study, known as the topical study of 'Agricultural Chemicals: Sources, Transport, and Fate' is part of the National Water-Quality Assessment Program being conducted by the U.S. Geological Survey. The Program is designed to describe water-quality conditions and trends based on representative surface- and ground-water resources across the Nation. The objective of the Agricultural Chemicals topical study is to investigate the sources, transport, and fate of selected agricultural chemicals in a variety of agriculturally diverse environmental settings. The Maple Creek watershed was selected for the Agricultural Chemicals topical study because its watershed represents the agricultural setting that characterizes eastern Nebraska. This report describes the environmental setting of the Maple Creek watershed in the context of how agricultural practices, including agricultural chemical applications and irrigation methods, interface with natural settings and hydrologic processes. A description of the environmental setting of a subwatershed within the drainage area of Maple Creek is included to improve the understanding of the variability of hydrologic and chemical cycles at two different scales.