Natural Reforestation Reclaims a Watershed: A Case History from West Virginia

Treesearch

W.P. Lima; J.H. Patric; N. Holowaychuk

1978-01-01

Thirteen years of hydrologic data from two contiguous small watersheds in West Virginia were analyzed to determine the effects on streamflow of natural reforestation on abandoned farmlands. During the study period (1958-1970), streamflow on the watersheds was unchanged. The history of land use on the study area helps explain the apparent lack of hydrologic effects of...

Applying hydropedology to nutrient management in the northeastern US: lessons learned from the Mahantango Creek Experimental Watershed

USDA-ARS?s Scientific Manuscript database

Understanding the nature and extent of soils prone to nutrient losses in runoff is central to the success of nutrient management in agricultural watersheds. Drawing upon case studies from USDA-ARS’s Mahantango Creek Experimental Watershed in east-central Pennsylvania, this presentation will discuss ...

INTEGRATING ECOLOGICAL RISK ASSESSMENT AND ECONOMIC ANALYSIS IN WATERSHEDS: A CONCEPTUAL APPROACH AND THREE CASE STUDIES

EPA Science Inventory

This document reports on a program of research to investigate the integration of ecological risk assessment (ERA) and economics, with an emphasis on the watershed as the scale for analysis. In 1993, the U.S. Environmental Protection Agency initiated watershed ERA (W-ERA) in five...

Impacts of fertilization on water quality of a drained pine plantation: a worst case scenario.

PubMed

Beltran, Bray J; Amatya, Devendra M; Youssef, Mohamed; Jones, Martin; Callahan, Timothy J; Skaggs, R Wayne; Nettles, Jami E

2010-01-01

Intensive plantation forestry will be increasingly important in the next 50 yr to meet the high demand for domestic wood in the United States. However, forest management practices can substantially influence downstream water quality and ecology. This study analyses, the effect of fertilization on effluent water quality of a low gradient drained coastal pine plantation in Carteret County, North Carolina using a paired watershed approach. The plantation consists of three watersheds, two mature (31-yr) and one young (8-yr) (age at treatment). One of the mature watersheds was commercially thinned in 2002. The mature unthinned watershed was designated as the control. The young and mature-thinned watersheds were fertilized at different rates with Arborite (Encee Chemical Sales, Inc., Bridgeton, NC), and boron. The outflow rates and nutrient concentrations in water drained from each of the watersheds were measured. Nutrient concentrations and loadings were analyzed using general linear models (GLM). Three large storm events occurred within 47 d of fertilization, which provided a worst case scenario for nutrient export from these watersheds to the receiving surface waters. Results showed that average nutrient concentrations soon after fertilization were significantly (alpha = 0.05) higher on both treatment watersheds than during any other period during the study. This increase in nutrient export was short lived and nutrient concentrations and loadings were back to prefertilization levels as soon as 3 mo after fertilization. Additionally, the mature-thinned watershed presented higher average nutrient concentrations and loadings when compared to the young watershed, which received a reduced fertilizer rate than the mature-thinned watershed.

Watershed sediment measurement and sediment transport modeling techniques: Case study to quantify the impact of converting cropland to forested stream buffers on soil loss and water quality at the watershed scale

USDA-ARS?s Scientific Manuscript database

Watershed models such as the Soil and Water Assessment Tool (SWAT) have been widely used to simulate watershed hydrologic processes and the effect of management, such as agroforestry, on soil and water resources. In order to use model outputs for tasks ranging from aiding policy decision making to r...

Mathematical modeling of synthetic unit hydrograph case study: Citarum watershed

NASA Astrophysics Data System (ADS)

Islahuddin, Muhammad; Sukrainingtyas, Adiska L. A.; Kusuma, M. Syahril B.; Soewono, Edy

2015-09-01

Deriving unit hydrograph is very important in analyzing watershed's hydrologic response of a rainfall event. In most cases, hourly measures of stream flow data needed in deriving unit hydrograph are not always available. Hence, one needs to develop methods for deriving unit hydrograph for ungagged watershed. Methods that have evolved are based on theoretical or empirical formulas relating hydrograph peak discharge and timing to watershed characteristics. These are usually referred to Synthetic Unit Hydrograph. In this paper, a gamma probability density function and its variant are used as mathematical approximations of a unit hydrograph for Citarum Watershed. The model is adjusted with real field condition by translation and scaling. Optimal parameters are determined by using Particle Swarm Optimization method with weighted objective function. With these models, a synthetic unit hydrograph can be developed and hydrologic parameters can be well predicted.

Tillamook Estuary Case Study: Local Drivers Influencing Coastal Acidification

EPA Science Inventory

US EPA initiated a study in the Tillamook estuary and watershed focused on the impact of changes in watershed land use, ocean conditions, and weather on estuarine water quality and ecosystem goods and services production within the estuary. This project is a collaboration betwee...

Development and application of a comprehensive simulation model to evaluate impacts of watershed structures and irrigation water use on streamflow and groundwater: The case of Wet Walnut Creek Watershed, Kansas, USA

USGS Publications Warehouse

Ramireddygari, S.R.; Sophocleous, M.A.; Koelliker, J.K.; Perkins, S.P.; Govindaraju, R.S.

2000-01-01

This paper presents the results of a comprehensive modeling study of surface and groundwater systems, including stream-aquifer interactions, for the Wet Walnut Creek Watershed in west-central Kansas. The main objective of this study was to assess the impacts of watershed structures and irrigation water use on streamflow and groundwater levels, which in turn affect availability of water for the Cheyenne Bottoms Wildlife Refuge Management area. The surface-water flow model, POTYLDR, and the groundwater flow model, MODFLOW, were combined into an integrated, watershed-scale, continuous simulation model. Major revisions and enhancements were made to the POTYLDR and MODFLOW models for simulating the detailed hydrologic budget for the Wet Walnut Creek Watershed. The computer simulation model was calibrated and verified using historical streamflow records (at Albert and Nekoma gaging stations), reported irrigation water use, observed water-level elevations in watershed structure pools, and groundwater levels in the alluvial aquifer system. To assess the impact of watershed structures and irrigation water use on streamflow and groundwater levels, a number of hypothetical management scenarios were simulated under various operational criteria for watershed structures and different annual limits on water use for irrigation. A standard 'base case' was defined to allow comparative analysis of the results of different scenarios. The simulated streamflows showed that watershed structures decrease both streamflows and groundwater levels in the watershed. The amount of water used for irrigation has a substantial effect on the total simulated streamflow and groundwater levels, indicating that irrigation is a major budget item for managing water resources in the watershed. (C) 2000 Elsevier Science B.V.This paper presents the results of a comprehensive modeling study of surface and groundwater systems, including stream-aquifer interactions, for the Wet Walnut Creek Watershed in west-central Kansas. The main objective of this study was to assess the impacts of watershed structures and irrigation water use on streamflow and groundwater levels, which in turn affect availability of water for the Cheyenne Bottoms Wildlife Refuge Management area. The surface-water flow model, POTYLDR, and the groundwater flow model, MODFLOW, were combined into an integrated, watershed-scale, continuous simulation model. Major revisions and enhancements were made to the POTYLDR and MODFLOW models for simulating the detailed hydrologic budget for the Wet Walnut Creek Watershed. The computer simulation model was calibrated and verified using historical streamflow records (at Albert and Nekoma gaging stations), reported irrigation water use, observed water-level elevations in watershed structure pools, and groundwater levels in the alluvial aquifer system. To assess the impact of watershed structures and irrigation water use on streamflow and groundwater levels, a number of hypothetical management scenarios were simulated under various operational criteria for watershed structures and different annual limits on water use for irrigation. A standard `base case' was defined to allow comparative analysis of the results of different scenarios. The simulated streamflows showed that watershed structures decrease both streamflows and groundwater levels in the watershed. The amount of water used for irrigation has a substantial effect on the total simulated streamflow and groundwater levels, indicating that irrigation is a major budget item for managing water resources in the watershed.A comprehensive simulation model that combines the surface water flow model POTYLDR and the groundwater flow model MODFLOW was used to study the impacts of watershed structures (e.g., dams) and irrigation water use (including stream-aquifer interactions) on streamflow and groundwater. The model was revised, enhanced, calibrated, and verified, then applied to evaluate the hydrologic budget for Wet Wal

Design and impact assessment of watershed investments: An approach based on ecosystem services and boundary work

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

Adem Esmail, Blal, E-mail: blal.ademesmail@unitn.it; Geneletti, Davide

Watershed investments, whose main aim is to secure water for cities, represent a promising opportunity for large-scale sustainability transitions in the near future. If properly designed, they promote activities in the watershed that enhance ecosystem services while protecting nature and biodiversity, as well as achieving other societal goals. In this paper, we build on the concepts of ecosystem services and boundary work, to develop and test an operative approach for designing and assessing the impact of watershed investments. The approach is structured to facilitate negotiations among stakeholders. Its strategic component includes setting the agenda; defining investment scenarios; and assessing themore » performance of watershed investments as well as planning for a follow-up. Its technical component concerns data processing; tailoring spatially explicit ecosystem service models; hence their application to design a set of “investment portfolios”, generate future land use scenarios, and model impacts on selected ecosystem services. A case study illustrates how the technical component can be developed in a data scarce context in sub-Saharan Africa in a way that is functional to support the steps of the strategic component. The case study addresses soil erosion and water scarcity-related challenges affecting Asmara, a medium-sized city in Eritrea, and considers urban water security and rural poverty alleviation as two illustrative objectives, within a ten-year planning horizon. The case study results consist in spatially explicit data (investment portfolio, land use scenario, impact on ecosystem services), which were aggregated to quantitatively assess the performance of different watershed investments scenarios, in terms of changes in soil erosion control. By addressing stakeholders' concerns of credibility, saliency, and legitimacy, the approach is expected to facilitate negotiation of objectives, definition of scenarios, and assessment of alternative watershed investments, ultimately, to contribute to implementing an adaptive watershed management.« less

Monitoring Consortiums: A Cost-Effective Means to Enhancing Watershed Data Collection and Analysis

EPA Pesticide Factsheets

Monitoring is essential for tracking overall watershed health, but monitoring costs are a limiting factor. As demonstrated in the four case studies, consortiums can reduce costs and improve cooperation among partners.

Conservation Management of Agriculture Land using Geospatial Approach (A Case Study in the Bone Watershed, Gorontalo Province, Indonesia)

NASA Astrophysics Data System (ADS)

Maryati, Sri; Eraku, Sunarty; Kasim, Muh

2018-02-01

Bone Watershed is one of the major watersheds in Gorontalo Province. Bone watershed has a very important role for the people of Gorontalo Province. The role of Bone Watershed is mainly related to the providing clean water, producing oxygen, controlling flood, providing habitat for endemic flora fauna and other environmental functions. The role of Bone Watershed for the community's economic sector is also very important, the Bone watershed provides livelihood for surrounding communities includes fertile land resources for agriculture and plantations, forest products, and livestock feed. This research is important considering the Bone watershed has limited availability of land for agriculture and the high risk of natural disasters such as floods and landslides. Geospatial data includes topography map, landform map, soil map, integrated with field survey results and soil properties were analized to determine conservation management of agriculture land in the Bone Watershed, Gorontalo Province, Indonesia. The result of this study shows that based on soil properties and physical land characteristics, land use for agriculture should consider appropriate conservation techniques, land capability and respect to local wisdom.

East Fork Watershed Cooperative: Toward better system-scale ...

EPA Pesticide Factsheets

The East Fork Watershed Cooperative is a group intent on understanding how to best manage water quality in a large mixed-use Midwestern watershed system. The system contains a reservoir that serves as a source of drinking water and is popular for water recreation. The reservoir is experience harmful algal blooms. The system including the reservoir has become a significant case study for EPA ORD research and development. The Cooperative includes affiliates from the USACE, the OHIO EPA, the USGS, the USDA, and local Soil and Water Conservation districts as well as utility operators and water quality protection offices. The presentation includes a description of the water quality monitoring and modeling program in the watershed, followed by the results of using the watershed model to estimate the costs associated with nutrient reduction to Harsha Lake, and then ends with an explanation of temporal changes observed for important factors controlling harmful algae in Harsha Lake and how this lake relates to other reservoirs in the Ohio River Basin. This presentation is an invited contribution to the Ohio River Basin Water Quality Workshop sponsored by the US ACE and the US EPA. The presentation describes the activities of the East Fork Watershed Cooperative and the knowledge it has gained to help better manage a case study watershed system over the last few years. The East Fork of the Little Miami River is the focal watershed. It is a significant tributary to the Lit

Community-based shared values as a 'Heart-ware' driver for integrated watershed management: Japan-Malaysia policy learning perspective

NASA Astrophysics Data System (ADS)

Mohamad, Zeeda Fatimah; Nasaruddin, Affan; Abd Kadir, Siti Norasiah; Musa, Mohd Noor; Ong, Benjamin; Sakai, Nobumitsu

2015-11-01

This paper explores the case for using ;community-based shared values; as a potential driver for the ;Heartware; aspects of governance in Integrated Watershed Management (IWM) - from a Japan-Malaysia policy learning perspective. This policy approach was originally inspired by the Japanese experience, and the paper investigates whether a similar strategy can be adapted in the Malaysian context-based on a qualitative exploratory case study of a local downstream watershed community. The community-based shared values are categorized into six functional values that can be placed on a watershed: industry, ecosystem, lifestyle, landscape, water resource and spirituality. The study confirmed the availability of a range of community-based shared values in each category that are promising to drive the heartware for integrated watershed management in the local Malaysian context. However, most of these shared values are either declining in its appreciation or nostalgic in nature. The paper ends with findings on key differences and similarities between the Malaysian and Japanese contexts, and concludes with lessons for international transfer of IWM heartware policy strategies between the two countries.

Compromise-based Robust Prioritization of Climate Change Adaptation Strategies for Watershed Management

NASA Astrophysics Data System (ADS)

Kim, Y.; Chung, E. S.

2014-12-01

This study suggests a robust prioritization framework for climate change adaptation strategies under multiple climate change scenarios with a case study of selecting sites for reusing treated wastewater (TWW) in a Korean urban watershed. The framework utilizes various multi-criteria decision making techniques, including the VIKOR method and the Shannon entropy-based weights. In this case study, the sustainability of TWW use is quantified with indicator-based approaches with the DPSIR framework, which considers both hydro-environmental and socio-economic aspects of the watershed management. Under the various climate change scenarios, the hydro-environmental responses to reusing TWW in potential alternative sub-watersheds are determined using the Hydrologic Simulation Program in Fortran (HSPF). The socio-economic indicators are obtained from the statistical databases. Sustainability scores for multiple scenarios are estimated individually and then integrated with the proposed approach. At last, the suggested framework allows us to prioritize adaptation strategies in a robust manner with varying levels of compromise between utility-based and regret-based strategies.

Spatiotemporal variation of watershed health propensity through reliability-resilience-vulnerability based drought index (case study: Shazand Watershed in Iran).

PubMed

Sadeghi, Seyed Hamidreza; Hazbavi, Zeinab

2017-06-01

Quantitative response of the watershed health to climate variability is of critical importance for watershed managers. However, existing studies seldom considered the impact of climate variability on watershed health. The present study therefore aimed to analyze the temporal and spatial variability of reliability (R el ), resilience (R es ) and vulnerability (V ul ) indicators in node years of 1986, 1998, 2008 and 2014 in connection with Standardized Precipitation Index (SPI) for 24 sub-watersheds in the Shazand Watershed of Markazi Province in Iran. The analysis was based on rainfall variability as one of the main climatic drivers. To achieve the study purposes, the monthly rainfall time series of eight rain gauge stations distributed across the watershed or neighboring areas were analyzed and corresponding SPIs and R el R es V ul indicators were calculated. Ultimately, the spatial variation of SPI oriented R el R es V ul was mapped for the study watershed using Geographic Information System (GIS). The average and standard deviation of SPI-R el R es V ul index for the study years of 1986, 1998, 2008 and 2014 was obtained 0.240±0.025, 0.290±0.036, 0.077±0.0280 and 0.241±0.081, respectively. In overall, the results of the study proved the spatiotemporal variations of SPI-R el R es V ul watershed health index in the study area. Accordingly, all the sub-watersheds of the Shazand Watershed were grouped in unhealthy and very unhealthy conditions in all the study years. For 1986 and 1998 all the sub-watersheds were assessed in unhealthy status. Whilst, it declined to very unhealthy condition in 2008 and then some 75% of the watershed ultimately referred again to unhealthy and the rest still remained under very unhealthy conditions in 2014. Copyright © 2017 Elsevier B.V. All rights reserved.

The Caspar Creek Watersheds--a case study

Treesearch

R. R. Ziemer

1990-01-01

Caspar Creek experimental watersheds are located on the Jackson Demonstration State Forest. Sponsors are the Pacific Southwest Research Station (PSW), USDA Forest Service, and the California Department of Forestry and Fire Protection (CDF). Both organizations have been working cooperatively since 1962

Applying soil property information for watershed assessment.

NASA Astrophysics Data System (ADS)

Archer, V.; Mayn, C.; Brown, S. R.

2017-12-01

The Forest Service uses a priority watershed scheme to guide where to direct watershed restoration work. Initial assessment was done across the nation following the watershed condition framework process. This assessment method uses soils information for a three step ranking across each 12 code hydrologic unit; however, the soil information used in the assessment may not provide adequate detail to guide work on the ground. Modern remote sensing information and terrain derivatives that model the environmental gradients hold promise of showing the influence of soil forming factors on watershed processes. These small scale data products enable the disaggregation of coarse scale soils mapping to show continuous soil property information across a watershed. When this information is coupled with the geomorphic and geologic information, watershed specialists can more aptly understand the controlling influences of drainage within watersheds and focus on where watershed restoration projects can have the most success. A case study on the application of this work shows where road restoration may be most effective.

The impact of watershed management on coastal morphology: A case study using an integrated approach and numerical modeling

NASA Astrophysics Data System (ADS)

Samaras, Achilleas G.; Koutitas, Christopher G.

2014-04-01

Coastal morphology evolves as the combined result of both natural- and human- induced factors that cover a wide range of spatial and temporal scales of effect. Areas in the vicinity of natural stream mouths are of special interest, as the direct connection with the upstream watershed extends the search for drivers of morphological evolution from the coastal area to the inland as well. Although the impact of changes in watersheds on the coastal sediment budget is well established, references that study concurrently the two fields and the quantification of their connection are scarce. In the present work, the impact of land-use changes in a watershed on coastal erosion is studied for a selected site in North Greece. Applications are based on an integrated approach to quantify the impact of watershed management on coastal morphology through numerical modeling. The watershed model SWAT and a shoreline evolution model developed by the authors (PELNCON-M) are used, evaluating with the latter the performance of the three longshore sediment transport rate formulae included in the model formulation. Results document the impact of crop abandonment on coastal erosion (agricultural land decrease from 23.3% to 5.1% is accompanied by the retreat of ~ 35 m in the vicinity of the stream mouth) and show the effect of sediment transport formula selection on the evolution of coastal morphology. Analysis denotes the relative importance of the parameters involved in the dynamics of watershed-coast systems, and - through the detailed description of a case study - is deemed to provide useful insights for researchers and policy-makers involved in their study.

Watershed management contributions to land stewardship: Case studies in the Southeast

Treesearch

Wayne T. Swank; David R. Tilley

2000-01-01

We describe three examples of watershed management studies, at different spatial scales, that provide approaches and information useful in enhancing natural resource stewardship in the southern Appalachians. A multiple use “pilot” study, initiated 35 years ago at the Coweeta Hydrologic Laboratory, demonstrates that southern Appalachian forests can be successfully...

Support for recreational trail development and community attachment: a case of the Soucook River Watershed

Treesearch

Jodi L. Michaud; Robert A. Robertson

2001-01-01

This study was conducted as part of a larger multi-community needs assessment. Data from this study allows for the determination of support for a multiple-use trail system linking communities within the Soucook River Watershed Region in New Hampshire. This study also examines the relationship between support for trail development and community attachment. The results...

Turkey Creek—a case study of ecohydrology and integrated watershed management in the low-gradient Atlantic Coastal Plain, USA

Treesearch

Devendra Amatya; Timothy Callahan; William Hansen; Carl Trettin; Artur Radecki-Pawlik; Patrick Meire

2015-01-01

Water yield, water supply and quality, wildlife habitat, and ecosystem productivity and services are important societal concerns for natural resource management in the 21st century. Watershed-scale ecohydrologic studies can provide needed context for addressing complex spatial and temporal dynamics of these functions and services. This study was...

Drinking water treatment plant costs and source water quality: An updated case study (2013-2016)

EPA Science Inventory

Watershed protection can play an important role in producing safe drinking water. However, many municipalities and drinking water treatment plants (DWTPs) lack the information on the potential benefits of watershed protection as an approach to improving source water quality. This...

Watershed-based survey designs

USGS Publications Warehouse

Detenbeck, N.E.; Cincotta, D.; Denver, J.M.; Greenlee, S.K.; Olsen, A.R.; Pitchford, A.M.

2005-01-01

Watershed-based sampling design and assessment tools help serve the multiple goals for water quality monitoring required under the Clean Water Act, including assessment of regional conditions to meet Section 305(b), identification of impaired water bodies or watersheds to meet Section 303(d), and development of empirical relationships between causes or sources of impairment and biological responses. Creation of GIS databases for hydrography, hydrologically corrected digital elevation models, and hydrologic derivatives such as watershed boundaries and upstream–downstream topology of subcatchments would provide a consistent seamless nationwide framework for these designs. The elements of a watershed-based sample framework can be represented either as a continuous infinite set defined by points along a linear stream network, or as a discrete set of watershed polygons. Watershed-based designs can be developed with existing probabilistic survey methods, including the use of unequal probability weighting, stratification, and two-stage frames for sampling. Case studies for monitoring of Atlantic Coastal Plain streams, West Virginia wadeable streams, and coastal Oregon streams illustrate three different approaches for selecting sites for watershed-based survey designs.

Watershed planning, implementation and assessment: the May River Watershed Action Plan case study

Treesearch

Kimberly W. Jones; Christopher L. Ellis; Jeremy S. Ritchie

2016-01-01

Prior to exponential growth in the early to mid-2000s, the Town of Bluffton, SC was one square mile; as of 2015, it is approximately 55 square miles. Associated with this growth was a shellfish harvesting closure for nearly onethird of the May River in 2009. The Town and its partners developed and began to implement the May River Watershed Action Plan in 2011. The plan...

Integrating socio-economic and biophysical data to enhance watershed management and planning

NASA Astrophysics Data System (ADS)

Pirani, Farshad Jalili; Mousavi, Seyed Alireza

2016-09-01

Sustainability has always been considered as one of the main aspects of watershed management plans. In many developing countries, watershed management practices and planning are usually performed by integrating biophysical layers, and other existing layers which cannot be identified as geographic layers are ignored. We introduce an approach to consider some socioeconomic parameters which are important for watershed management decisions. Ganj basin in Chaharmahal-Bakhtiari Province was selected as the case study area, which includes three traditional sanctums: Ganj, Shiremard and Gerdabe Olya. Socioeconomic data including net agricultural income, net ranching income, population and household number, literacy rate, unemployment rate, population growth rate and active population were mapped within traditional sanctums and then were integrated into other biophysical layers. After overlaying and processing these data to determine management units, different quantitative and qualitative approaches were adopted to achieve a practical framework for watershed management planning and relevant plans for homogeneous units were afterwards proposed. Comparing the results with current plans, the area of allocated lands to different proposed operations considering both qualitative and quantitative approaches were the same in many cases and there was a meaningful difference with current plans; e.g., 3820 ha of lands are currently managed under an enclosure plan, while qualitative and quantitative approaches in this study suggest 1388 and 1428 ha to be allocated to this operation type, respectively. Findings show that despite the ambiguities and complexities, different techniques could be adopted to incorporate socioeconomic conditions in watershed management plans. This introductory approach will help to enhance watershed management decisions with more attention to societal background and economic conditions, which will presumably motivate local communities to participate in watershed management plans.

Watershed Adaptation Measures to Climate Change Impacts: A case of Kiha Watershed in Albertine Graben

NASA Astrophysics Data System (ADS)

Zizinga, A.

2017-12-01

Watershed Adaptation Measures to Climate Change Impacts: A case of Kiha Watershed in Albertine GrabenAlex Zizinga1, Moses Tenywa2, Majaliwa Jackson Gilbert1, 1Makerere University, Department of Environmental Sciences, O Box 7062, Kampala, Uganda 1Makerere University, Department of Agricultural Production, P.O Box 7062, Kampala, Uganda Corresponding author: azizinga@caes.mak.ac.ug AbstractThe most pressing issues local communities in Uganda are facing result from land-use and land cover changes exacerbated by climate change impacts. A key issue is the documentation of land-cover changes visible with the ongoing clearance of remaining forests, bush-lands and wetlands for expanding farmland for sugarcane production, producing charcoal and collecting firewood for local distilleries using imported molasses. Decision-makers, resource managers, farmers and practitioners must build their capacity for adaptive measures. Here we present the potential impacts of climate change on watershed hydrological processes in the River Kiha Watershed, located in Western Uganda, Lake Albert Water Management Zone, by using social learning techniques incorporating water users, local stakeholders and researchers. The research team examined different farming and economic activities within the watershed to assess their impacts on catchment water resources, namely on water quality and discharge of river Kiha. We present the impacts of locally induced climate change, which are already manifested in increasing seasonal variability of rainfall. The study aims at answering questions posed by local communities and stakeholders about climate change and its effects on livelihood and key resources, specifically water and soils within the Kiha watershed. Key words: Climate change impacts, Social Learning and Watershed Management

[Watershed water environment pollution models and their applications: a review].

PubMed

Zhu, Yao; Liang, Zhi-Wei; Li, Wei; Yang, Yi; Yang, Mu-Yi; Mao, Wei; Xu, Han-Li; Wu, Wei-Xiang

2013-10-01

Watershed water environment pollution model is the important tool for studying watershed environmental problems. Through the quantitative description of the complicated pollution processes of whole watershed system and its parts, the model can identify the main sources and migration pathways of pollutants, estimate the pollutant loadings, and evaluate their impacts on water environment, providing a basis for watershed planning and management. This paper reviewed the watershed water environment models widely applied at home and abroad, with the focuses on the models of pollutants loading (GWLF and PLOAD), water quality of received water bodies (QUAL2E and WASP), and the watershed models integrated pollutant loadings and water quality (HSPF, SWAT, AGNPS, AnnAGNPS, and SWMM), and introduced the structures, principles, and main characteristics as well as the limitations in practical applications of these models. The other models of water quality (CE-QUAL-W2, EFDC, and AQUATOX) and watershed models (GLEAMS and MIKE SHE) were also briefly introduced. Through the case analysis on the applications of single model and integrated models, the development trend and application prospect of the watershed water environment pollution models were discussed.

Effectiveness of conservation practices within watersheds: Case study in tile-drained systems

USDA-ARS?s Scientific Manuscript database

The effectiveness of conservation practices are governed in part by the spatial and temporal patterns of water flow as runoff and subsurface (tile) drainage. The variability in patterns of nitrate loss were examined using data from different sized catchments with four CEAP watersheds located in cent...

Drinking water treatment plant costs and source water quality: An updated case study (2013-2016) Abstract

EPA Science Inventory

Watershed protection can play an important role in producing safe drinking water. However, many municipalities and drinking water treatment plants (DWTPs) lack the information on the potential benefits of watershed protection as an approach to improving source water quality. This...

Watershed Nitrogen Modeling: Benefits of Diverse Approaches Using a Case Study from New York State

EPA Science Inventory

Watershed-scale models have evolved as an important tool for estimating the sources, transformation, and transport of contaminants to surface water systems. A wide variety of modeling approaches exist for estimating inputs, fate, and transport of constituents but most are broadl...

CAUSAL ANALYSIS OF BIOLOGICAL IMPAIRMENT IN LONG CREEK, A SANDY-BOTTOMED STREAM IN COASTAL SOUTHERN MAINE (Final Report)

EPA Science Inventory

This assessment presents results from a complex causal assessment of a biologically impaired, urbanized coastal watershed located primarily in South Portland, Maine, USA—the Long Creek watershed. This case study serves as an example implementation of U.S. Environmental Protectio...

Research on Coupling Method of Watershed Initial Water Rights Allocation in Daling River

NASA Astrophysics Data System (ADS)

Liu, J.; Fengping, W.

2016-12-01

Water scarcity is now a common occurrence in many countries. The situation of watershed initial water rights allocation has caused many benefit conflicts among regions and regional water sectors of domestic and ecology environment and industries in China. This study aims to investigate the method of watershed initial water rights allocation in the perspective of coupling in Daling River Watershed taking provincial initial water rights and watershed-level governmental reserved water as objects. First of all, regarding the allocation subsystem of initial water rights among provinces, this research calculates initial water rights of different provinces by establishing the coupling model of water quantity and quality on the principle of "rewarding efficiency and penalizing inefficiency" based on the two control objectives of water quantity and quality. Secondly, regarding the allocation subsystem of watershed-level governmental reserved water rights, the study forecasts the demand of watershed-level governmental reserved water rights by the combination of case-based reasoning and water supply quotas. Then, the bilaterally coupled allocation model on water supply and demand is designed after supply analysis to get watershed-level governmental reserved water rights. The results of research method applied to Daling River Watershed reveal the recommended scheme of watershed initial water rights allocation based on coordinated degree criterion. It's found that the feasibility of the iteration coupling model and put forward related policies and suggestions. This study owns the advantages of complying with watershed initial water rights allocation mechanism and meeting the control requirements of water quantity, water quality and water utilization efficiency, which help to achieve the effective allocation of water resources.

Understanding controls of hydrologic processes across two headwater monolithological catchments using model-data synthesis

NASA Astrophysics Data System (ADS)

Xiao, D.; Shi, Y.; Hoagland, B.; Del Vecchio, J.; Russo, T. A.; DiBiase, R. A.; Li, L.

2017-12-01

How do watershed hydrologic processes differ in catchments derived from different lithology? This study compares two first order, deciduous forest watersheds in Pennsylvania, a sandstone watershed, Garner Run (GR, 1.34 km2), and a shale-derived watershed, Shale Hills (SH, 0.08 km2). Both watersheds are simulated using a combination of national datasets and field measurements, and a physics-based land surface hydrologic model, Flux-PIHM. We aim to evaluate the effects of lithology on watershed hydrology and assess if we can simulate a new watershed without intensive measurements, i.e., directly use calibration information from one watershed (SH) to reproduce hydrologic dynamics of another watershed (GR). Without any calibration, the model at GR based on national datasets and calibration inforamtion from SH cannot capture some discharge peaks or the baseflow during dry periods. The model prediction agrees well with the GR field discharge and soil moisture after calibrating the soil hydraulic parameters using the uncertainty based Hornberger-Spear-Young algorithm and the Latin Hypercube Sampling method. Agreeing with the field observation and national datasets, the difference in parameter values shows that the sandstone watershed has a larger averaged soil pore diameter, greater water storage created by porosity, lower water retention ability, and greater preferential flow. The water budget calculation shows that the riparian zone and the colluvial valley serves as buffer zones that stores water at GR. Using the same procedure, we compared Flux-PIHM simulations with and without a field measured surface boulder map at GR. When the boulder map is used, the prediction of areal averaged soil moisture is improved, without performing extra calibration. When calibrated separately, the cases with or without boulder map yield different calibration values, but their hydrologic predictions are similar, showing equifinality. The calibrated soil hydraulic parameter values in the with boulder map case is more physically plausible than the without boulder map case. We switched the topography and soil properties between GR and SH, and results indicate that the hydrologic processes are more sensitive to changes in domain topography than to changes in the soil properties.

Using surveys as input to comprehensive watershed management: a case study from Minnesota.

Treesearch

Tim Kelly; Ron Sushak

1996-01-01

As a compliment to direct citizen participation, the Minnesota Department of Natural Resources used a survey of area landowners to help inform its comprehensive watershed management initiative. Results from the survey have been useful to resource managers and area residents as they carry out this planning effort.

A Review on Flood Events for Kelantan River Watershed in Malaysia for Last Decade (2001-2010)

NASA Astrophysics Data System (ADS)

Aminah Shakirah, J.; Sidek, L. M.; Hidayah, B.; Nazirul, M. Z.; Jajarmizadeh, M.; Ros, F. C.; Roseli, ZA

2016-03-01

Malaysia is located at tropical zone and high precipitation area that frequently hit by flood events when it is near monsoon season. This hydro hazard has been one of the main concerns for governmental and non-governmental sectors. High floods lead in financial damages and they are related with human’s life. Kelantan watershed is one of the challenging watersheds which mostly suffer from flood events and heavy rainfall events. Flood in Kelantan watershed is related with monetary misfortunes and lives. Clearly, flood have significant influence on various water sectors such water supply, agriculture, human health and ecosystems therefore study of this topic and presentation of available of any data and information can be a valuable baseline for upcoming research in vulnerable case studies. In this study, Kelantan watershed is selected because it is prone to flooding and urban areas classified as vulnerable districts. This overview is discussed on the last decade (2001-2010) floods events in Kelantan.

Cross-boundary cooperation in a watershed context: the sentiments of private forest landowners.

PubMed

Rickenbach, Mark G; Reed, A Scott

2002-10-01

Ecosystem management and sustainable forestry on mixed ownership landscapes will require some level of cross-boundary coordination or management. Oregon's experiment with local, voluntary, collaborative forums, called watershed councils, is one mechanism to foster cross-boundary management. Fifty qualitative, in-depth interviews in three study areas were conducted with nonindustrial private forest (NIPF) landowners, watershed council members, and agency employees to learn how and why landowners participate (or not) on watershed councils. Study areas were located in three different areas of the state to reflect different ecological and organizational settings. Our case study identified three themes-stewardship ethic, property rights amid uncertainty, and action orientation-that were most salient among landowners when deciding to participate in their local watershed council. Other factors related to competing opportunities were also identified. Our results relate to the social psychological antecedents to cooperation of perceived consensus, group identity, and legitimacy of authority as well as to applied situations where cross-boundary coordination and management are goals.

An Integrated Risk Management Model for Source Water Protection Areas

PubMed Central

Chiueh, Pei-Te; Shang, Wei-Ting; Lo, Shang-Lien

2012-01-01

Watersheds are recognized as the most effective management unit for the protection of water resources. For surface water supplies that use water from upstream watersheds, evaluating threats to water quality and implementing a watershed management plan are crucial for the maintenance of drinking water safe for humans. The aim of this article is to establish a risk assessment model that provides basic information for identifying critical pollutants and areas at high risk for degraded water quality. In this study, a quantitative risk model that uses hazard quotients for each water quality parameter was combined with a qualitative risk model that uses the relative risk level of potential pollution events in order to characterize the current condition and potential risk of watersheds providing drinking water. In a case study of Taipei Source Water Area in northern Taiwan, total coliforms and total phosphorus were the top two pollutants of concern. Intensive tea-growing and recreational activities around the riparian zone may contribute the greatest pollution to the watershed. Our risk assessment tool may be enhanced by developing, recording, and updating information on pollution sources in the water supply watersheds. Moreover, management authorities could use the resultant information to create watershed risk management plans. PMID:23202770

How Do Land-Use and Climate Change Affect Watershed ...

EPA Pesticide Factsheets

With the growing emphasis on biofuel crops and potential impacts of climate variability and change, there is a need to quantify their effects on hydrological processes for developing watershed management plans. Environmental consequences are currently estimated by utilizing computer models such as Soil and Water Assessment Tool (SWAT) to simulate watershed hydrology under projected climate and land-use scenarios to assess the effect on water quantity and/or quality. Such studies have largely been deterministic in nature, with the focus being on whether hydrologic variables such as runoff, sediment and/or nutrient loads increase or decrease from the baseline case under projected scenarios. However, studying how these changes would affect watershed health in a risk-based framework has not been attempted. In this study, impacts of several projected land-use and climate change scenarios on the health of the Wildcat Creek watershed in Indiana have been assessed through three risk indicators, namely reliability-resilience-vulnerability (R-R-V). Results indicate that cultivation of biofuel crops such as Miscanthus and switchgrass has the potential to improve risk indicator values with respect to sediment, total N and total P. Climate change scenarios that involved rising precipitation levels were found to negatively impact watershed health indicators. Trends of water quality constituents under risk-based watershed health assessment revealed nuances not readily a

Watershed modeling and monitoring for assessing nutrient ...

EPA Pesticide Factsheets

Presentation for the American Water Works Association Water Sustainability Conference. The presentation highlights latest results from water quality trading research conducted by ORD using the East Fork Watershed in Southwestern Ohio as a case study. The watershed has a nutrient enrichment problem that is creating harmful algal blooms in a reservoir used for drinking water and recreation. Innovative modeling and monitoring is combined to understand how to best manage this water quality problem and costs associated with this endeavor. The presentation will provide an overview of the water quality trading feasibility research. The research includes the development and evaluation of innovative modeling and monitoring approaches to manage watersheds for nutrient pollution using a whole systems approach.

Effect of detention basin release rates on flood flows - Application of a model to the Blackberry Creek Watershed in Kane County, Illinois

USGS Publications Warehouse

Soong, David T.; Murphy, Elizabeth A.; Straub, Timothy D.

2009-01-01

The effects of stormwater detention basins with specified release rates are examined on the watershed scale with a Hydrological Simulation Program - FORTRAN (HSPF) continuous-simulation model. Modeling procedures for specifying release rates from detention basins with orifice and weir discharge configurations are discussed in this report. To facilitate future detention modeling as a tool for watershed management, a chart relating watershed impervious area to detention volume is presented. The report also presents a case study of the Blackberry Creek watershed in Kane County, Ill., a rapidly urbanizing area seeking to avoid future flood damages from increased urbanization, to illustrate the effects of various detention basin release rates on flood peaks and volumes and flood frequencies. The case study compares flows simulated with a 1996 land-use HSPF model to those simulated with four different 2020 projected land-use HSPF model scenarios - no detention, and detention basins with release rates of 0.08, 0.10, and 0.12 cubic feet per second per acre (ft3/s-acre), respectively. Results of the simulations for 15 locations, which included the downstream ends of all tributaries and various locations along the main stem, showed that a release rate of 0.10 ft3/s-acre, in general, can maintain postdevelopment 100-year peak-flood discharge at a similar magnitude to that of 1996 land-use conditions. Although the release rate is designed to reduce the 100-year peak flow, reduction of the 2-year peak flow is also achieved for a smaller proportion of the peak. Results also showed that the 0.10 ft3/s-acre release rate was less effective in watersheds with relatively high percentages of preexisting (1996) development than in watersheds with less preexisting development.

Compatability of timber salvage operations with watershed values

Treesearch

Roger J. Poff

1989-01-01

Timber salvage on the Indian Burn was carried out without compromising watershed values. In some cases watershed condition was actually improved by providing ground cover, by removing trees that were a source of erosive water droplets, and by breaking up hydrophobic soil layers. Negative impacts of timber salvage on watersheds were minimized by using an...

SCIENCE FOR INTEGRATED WATERSHED MANAGEMENT: A MULTI-SCALE EXPERIMENTAL CASE STUDY LINKING LAND USE MANAGEMENT PRACTICES AND WATER QUALITY IN SOUTHERN OHIO

EPA Science Inventory

Although it is routine for watershed management programs to coincide the monitoring of land use impacts and water quality at different spatial scales, rarely are the data collected in a manner to elucidate the linkages among ecological systems across a drainage network. There rem...

A Regionalized Flow Duration Curve Method to Predict Streamflow for Ungauaged Basins: A Case Study of the Rappahannock Watershed in Virginia, USA

EPA Science Inventory

A method to predict streamflow for ungauged basins of the Mid-Atlantic Region, USA was applied to the Rappahannock watershed in Virginia, USA. The method separates streamflow time series into magnitude and time sequence components. It uses the regionalized flow duration curve (RF...

The influence of Holocene vegetation changes on topography and erosion rates: a case study at Walnut Gulch Experimental Watershed

USDA-ARS?s Scientific Manuscript database

The Walnut Gulch Experimental Watershed (WGEW) is dominated by grasslands at high elevations and shrublands at low elevations. Paleovegetation data suggest that portions of WGEW higher than approximately 1430 m a.s.l. have been grasslands and/or woodlands throughout the Quaternary, while lower eleva...

Impacts of domestic and and agricultural rainwater harvesting system on watershed hydrology: A case study of Albemarle-Pamlico Watershed basins (NC, VA, USA)

EPA Science Inventory

Rainwater harvesting (RWH) is increasingly relevant in the context of growing population and its demands on water quantity. Here, we present a method to better understand the hydrologic impacts of urban domestic and agricultural rainwater harvesting and apply the approach to thre...

Erosion at decommissioned road-stream crossings: case studies from three northern California watersheds

Treesearch

Sam A. Flanagan; David Fuller; Leonard Job; Sam Morrison

2012-01-01

Post-treatment erosion was observed for 41 decommissioned road stream crossings in three northern California watersheds. Sites were purposefully selected in order to characterize the nature and range of post-treatment erosional responses. Sites with the highest visible erosion were selected in order to better understand the dominant process and incorporate any...

Assessing long-term hydrologic impact of climate change using ensemble approach and comparison with Global Gridded Model-A case study on Goodwater Creek Experimental Watershed

USDA-ARS?s Scientific Manuscript database

Potential impacts of climate change on hydrologic components of Goodwater Creek Experimental Watershed were assessed using climate datasets from the Coupled Model Intercomparison Project Phase 5 and Soil and Water Assessment Tool (SWAT). Historical and future ensembles of downscaled precipitation an...

GIS soil conservation planning: A case study of a pristine Central America watershed

Treesearch

Steven Shultz

2000-01-01

In the Pacuare River Watershed in Costa Rica, farm size, ownership, and production data were collected and spatially referenced through global positioning surveys and farmer assessments of property boundaries in relation to cadastral maps and air photographs. Using GIs based spatial overlays, this data were integrated with previously collected land use and land...

A Case Study of Differing Effects of Urbanization on Streamflow From Two Proximate Watersheds

NASA Astrophysics Data System (ADS)

Brandes, D.; Lott, F.

2007-12-01

The effects of urbanization on streamflow from two proximate watersheds (Little Lehigh Creek (LLC) and Monocacy Creek (MC)) are investigated. Despite close similarities in rainfall, population growth, land use, imperviousness, and geology of the watersheds, streamflows at the LLC gage have changed markedly over the past 50 years, while those at the MC gage have not. In LLC, there are significant increasing trends in annual stormflow volume, annual maximum flow, and flashiness, but there are no significant trends in these measures in MC. Neither stream shows significant trends in annual baseflow volume or low flow. It appears that the distinct difference in response to urbanization of these two streams can be ascribed to differences in 1) watershed geomorphology, 2) spatial distribution, composition, and infiltration characteristics of carbonate bedrock, and 3) the spatial pattern of land development in each watershed with respect to the gage location. In regards to geomorphology, there is a steeper main channel and narrower floodplains in LLC than in MC. Carbonate soil and bedrock (primarily dolostone) are distributed throughout much of LLC watershed but only in the lower half of MC watershed; however the lower MC watershed (primarily limestone) has much more abundant sinkholes and karst features than in the LLC watershed. Finally, residential and commercial development is concentrated in the upper two thirds of the LLC watershed, where travel times are such that these areas contribute to the peak flows measured at the gage. Development is concentrated in the lower third of the MC watershed, where it has had less effect on peak flows at the gage. Overall, the study indicates that relatively subtle differences between watershed characteristics and development patterns can result in significant differences in runoff and in how streamflow regimes may change in response to urbanization.

The Caspar Creek watersheds: a case study of cumulative effects in a small coastal basin in northern California

Treesearch

R. R. Ziemer; P. H. Cafferata

1991-01-01

Abstract - Since 1962, the 483-ha North Fork and 424-ha South Fork of Caspar Creek in northwestern California have been used to evaluate the hydrologic impacts of road building and harvesting second-growth redwood/Douglas-fir forests. Three tributaries are serving as untreated controls. In 1985, the study was modified to evaluate the cumulative watershed effects of...

Impacts of channel deposition on the risk of flooding in a watershed

NASA Astrophysics Data System (ADS)

Ting-Yue, Hong; Chia-Ling, Chang

2017-04-01

Taiwan is located in East Asian where is always hit by typhoons. Typhoons usually bring huge amounts of rainfall and result in the problems of channel deposition. Deposition influences the functions of channel and increases the risk of flooding. The Luliao Reservoir Watershed is the case area in this study. It is the major water source for agricultural activity and domestic use. The objective of this study is to assess the possible impacts of channel deposition on the watershed environment. This study applies the Storm Water Management Model (SWMM) to predict the hydrologic responses and evaluate the risk of flooding. The results show that the decrease of cross section induced by deposition in a channel may increase the risk of flooding and impact the safety of watershed environment. Therefore, canal desilting is important in channel regulation. The discussion and analysis can be useful references for channel regulation.

A framework for assessing cumulative effects in watersheds: an introduction to Canadian case studies.

PubMed

Dubé, Monique G; Duinker, Peter; Greig, Lorne; Carver, Martin; Servos, Mark; McMaster, Mark; Noble, Bram; Schreier, Hans; Jackson, Lee; Munkittrick, Kelly R

2013-07-01

From 2008 to 2013, a series of studies supported by the Canadian Water Network were conducted in Canadian watersheds in an effort to improve methods to assess cumulative effects. These studies fit under a common framework for watershed cumulative effects assessment (CEA). This article presents an introduction to the Special Series on Watershed CEA in IEAM including the framework and its impetus, a brief introduction to each of the articles in the series, challenges, and a path forward. The framework includes a regional water monitoring program that produces 3 core outputs: an accumulated state assessment, stressor-response relationships, and development of predictive cumulative effects scenario models. The framework considers core values, indicators, thresholds, and use of consistent terminology. It emphasizes that CEA requires 2 components, accumulated state quantification and predictive scenario forecasting. It recognizes both of these components must be supported by a regional, multiscale monitoring program. Copyright © 2013 SETAC.

Predicting the Impacts of Climate Change on Runoff and Sediment Processes in Agricultural Watersheds: A Case Study from the Sunflower Watershed in the Lower Mississippi Basin

NASA Astrophysics Data System (ADS)

Elkadiri, R.; Momm, H.; Yasarer, L.; Armour, G. L.

2017-12-01

Climatic conditions play a major role in physical processes impacting soil and agrochemicals detachment and transportation from/in agricultural watersheds. In addition, these climatic conditions are projected to significantly vary spatially and temporally in the 21st century, leading to vast uncertainties about the future of sediment and non-point source pollution transport in agricultural watersheds. In this study, we selected the sunflower basin in the lower Mississippi River basin, USA to contribute in the understanding of how climate change affects watershed processes and the transport of pollutant loads. The climate projections used in this study were retrieved from the archive of World Climate Research Programme's (WCRP) Coupled Model Intercomparison Phase 5 (CMIP5) project. The CMIP5 dataset was selected because it contains the most up-to-date spatially downscaled and bias corrected climate projections. A subset of ten GCMs representing a range in projected climate were spatially downscaled for the sunflower watershed. Statistics derived from downscaled GCM output representing the 2011-2040, 2041-2070 and 2071-2100 time periods were used to generate maximum/minimum temperature and precipitation on a daily time step using the USDA Synthetic Weather Generator, SYNTOR. These downscaled climate data were then utilized as inputs to run in the Annualized Agricultural Non-Point Source (AnnAGNPS) pollution watershed model to estimate time series of runoff, sediment, and nutrient loads produced from the watershed. For baseline conditions a validated simulation of the watershed was created and validated using historical data from 2000 until 2015.

A CASE STUDY OF ENVIRONMENTAL DATA MANAGEMENT

EPA Science Inventory

In order to support our ongoing research in watershed ecology and global climate change, we gather and analyze environmental data from several government agencies. This case study demonstrates a researcher’s approach to accessing, organizing, and using intersectoral data. T...

Parcelization and land use: A case study in the New York City Watershed

Treesearch

Jennifer A. Caron; Rene H. Germain; Nathaniel M. Anderson

2012-01-01

Over 75% of the New York City Watershed is forested, and the majority of the land is owned by family forest owners. Ownership fragmentation and development may impact both the working forested landscape and water quality. We surveyed the owners of intact and subdivided family forest parcels across various parcel sizes to gauge their awareness of forest management...

Changing people's perceptions and behavior through partnerships and education: followup on a case study from Minnesota

Treesearch

Tim Kelly; Ron Sushak; Pamela Jakes

2001-01-01

A follow-up survey of residents in southeastern Minnesota shows that environmental values were stable over a 5-year period. The authors were unable to measure any impacts of a Minnesota Department of Natural Resources comprehensive watershed planning initiative in the Wells Creek watershed on residents' behaviors and attitudes and perceptions about the...

7 CFR 624.5 - Coordination.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AGRICULTURE WATER RESOURCES EMERGENCY WATERSHED PROTECTION § 624.5 Coordination. (a) If the President declares... Presidentially-declared natural disasters. (b) When an NRCS State Conservationist determines that a watershed... agencies involved with emergency activities, as appropriate. (c) In the case where the watershed impairment...

7 CFR 624.5 - Coordination.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AGRICULTURE WATER RESOURCES EMERGENCY WATERSHED PROTECTION § 624.5 Coordination. (a) If the President declares... Presidentially-declared natural disasters. (b) When an NRCS State Conservationist determines that a watershed... agencies involved with emergency activities, as appropriate. (c) In the case where the watershed impairment...

7 CFR 624.5 - Coordination.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AGRICULTURE WATER RESOURCES EMERGENCY WATERSHED PROTECTION § 624.5 Coordination. (a) If the President declares... Presidentially-declared natural disasters. (b) When an NRCS State Conservationist determines that a watershed... agencies involved with emergency activities, as appropriate. (c) In the case where the watershed impairment...

INTEGRATED WATERSHED MANAGEMENT: PRINCIPLES AND PRACTICE. Book Review

EPA Science Inventory

Through a wide range of information and topics, Integrated Watershed Management Principles and Practice shows how involved the watershed management planning process can be. The book is informative, and the author obviously has researched the subject thoroughly. The book's case...

Unit Hydrograph Peaking Analysis for Goose Creek Watershed in Virginia: A Case Study

DTIC Science & Technology

2017-05-01

increment would not exceed 1.5 times the designed unit peak. The purpose of this study is to analyze the validity of this UHPF range of the Goose...confidence interval precipitation depths to the watershed in addition to the 50% value. This study concluded that a design event with a return period greater...In this study , the physically based GSSHA model was deployed to obtain corresponding design discharge from probable rainfall events. 3.2.1 GSSHA

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

NASA Astrophysics Data System (ADS)

Alford, C.

2009-12-01

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

Optimization of green infrastructure network at semi-urbanized watersheds to manage stormwater volume, peak flow and life cycle cost: Case study of Dead Run watershed in Maryland

NASA Astrophysics Data System (ADS)

Heidari Haratmeh, B.; Rai, A.; Minsker, B. S.

2016-12-01

Green Infrastructure (GI) has become widely known as a sustainable solution for stormwater management in urban environments. Despite more recognition and acknowledgment, researchers and practitioners lack clear and explicit guidelines on how GI practices should be implemented in urban settings. This study is developing a noisy-based multi-objective, multi-scaled genetic algorithm that determines optimal GI networks for environmental, economic and social objectives. The methodology accounts for uncertainty in modeling results and is designed to perform at sub-watershed as well as patch scale using two different simulation models, SWMM and RHESSys, in a Cloud-based implementation using a Web interface. As an initial case study, a semi-urbanized watershed— DeadRun 5— in Baltimore County, Maryland, is selected. The objective of the study is to minimize life cycle cost, maximize human preference for human well-being and the difference between pre-development hydrographs generated from current rainfall events and design storms, as well as those that result from proposed GI scenarios. Initial results for DeadRun5 watershed suggest that placing GI in the proximity of the watershed outlet optimizes life cycle cost, stormwater volume, and peak flow capture. The framework can easily present outcomes of GI design scenarios to both designers and local stakeholders, and future plans include receiving feedback from users on candidate designs, and interactively updating optimal GI network designs in a crowd-sourced design process. This approach can also be helpful in deriving design guidelines that better meet stakeholder needs.

Water resources protection today: end-of-pipe technology and cleaner production. Case study of the Czech Odra River watershed.

PubMed

Chour, V

2001-01-01

This paper reports on integrated watershed-based protection and sustainable use of water resources to increase the effectiveness of water pollution abatement. The approach includes improvements in end-of-pipe waste-water treatment technologies and implementation of Cleaner Production (CP) principles and policies within the watershed. An example of the general effectiveness of this approach is illustrated by the Czech Odra River Cleaner Production Project where reductions in pollution were achieved with improved industrial production. The CP theme is worth considering as an important challenge for the IWA.

Synthesis of nutrient and sediment export patterns in the Chesapeake Bay watershed: Complex and non-stationary concentration-discharge relationships.

PubMed

Zhang, Qian

2018-03-15

Derived from river monitoring data, concentration-discharge (C-Q) relationships are useful indicators of riverine export dynamics. A top-down synthesis of C-Q patterns was conducted for suspended sediment (SS), total phosphorus (TP), and total nitrogen (TN) for nine major tributaries (15 monitoring sites) to Chesapeake Bay, which represent diverse characteristics in terms of land use, physiography, and hydrological settings. Model coefficients from the recently-developed Weighted Regressions on Time, Discharge, and Season (WRTDS) method were used to make informative interpretation of C-Q relationships. Unlike many previous C-Q studies that focused on stormflow conditions, this approach allows simultaneous examination of various discharge conditions within an uncertainty framework. This synthesis on WRTDS coefficients (i.e., the sensitivity of concentration to discharge) has offered new insights on the complexity of watershed function. Results show that watershed export has been dominated by mobilization patterns for SS and TP (particulate-dominated species) and chemostasis patterns for TN (dissolved-dominated species) under many river discharge conditions. Among nine possible modalities of low-flow vs. high-flow patterns, the three most frequent modalities are mobilization vs. mobilization (17 cases), chemostasis vs. mobilization (13 cases), and chemostasis vs. chemostasis (7 cases), representing 82% of all 45 watershed-constituent pairs. The general lack of dilution patterns may suggest that none of these constituents has been supply-limited in these watersheds. For many watershed-constituent combinations, results show clear temporal non-stationarity in C-Q relationships under selected time-invariant discharges, reflecting major changes in dominant watershed sources due to anthropogenic actions. These results highlight the potential pitfalls of assuming fixed C-Q relationships in the record. Overall, this work demonstrates the utility of WRTDS model coefficients for interpretation of river water-quality data and for generation of sensible hypotheses on dominant processes in different watersheds. The approach is readily adaptable to other river systems, where long-term discretely-sampled data are available, to decipher complex interactions between hydrological and biogeochemical processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Reconstructing Historical Changes in Watersheds from Environmental Records: An Information Theory Approach

NASA Astrophysics Data System (ADS)

Guerrero, F. J.; Hatten, J. A.; Ruddell, B.; Penaranda, V.; Murillo, P.

2015-12-01

A 20% of the world's population is living in watersheds that suffer from water shortage. This situation has complex causes associated with historical changes in watersheds. However, disentangling the role of key drivers of water availability like climate change or land use practices is challenging. Part of the difficulty resides in that historical analysis is basically a process of empirical reconstruction from available environmental records (e.g. sediment cores or long-term hydrologic time series). We developed a mathematical approach, based on information theory, for historical reconstructions in watersheds. We analyze spectral entropies calculated directly or indirectly for sediment cores or long-term hydrologic time series respectively. Spectral entropy measures changes in Shannon's information of natural patterns (e.g. particle size distributions in lake bottoms or streamflow regimes) as they respond to different drivers. We illustrate the application of our approach with two case studies: a reconstruction of a time series of historical changes from a sediment core, and the detection of hydrologic alterations in watersheds associated to climate and forestry activities. In the first case we calculated spectral entropies from 700 sediment layers encompassing 1500 years of history in Loon Lake (Southern Oregon). In the second case, we calculated annual spectral entropies from daily discharge for the last 45 years in two experimental watersheds in the H. J. Andrews LTER site (Oregon Cascades). In Loon Lake our approach separated, without supervision, earthquakes from landslides and floods. It can also help to improve age models for sedimentary layers. At H. J. Andrews's sites our approach was able to identify hydrological alterations following a complete clear cut in 1975. It is also helpful to identify potential long-term impacts of these forestry activities, enhanced by climate change. Our results suggest that spectral entropy is central for translating between historical structural changes in natural patterns, and their timing and relevance in watershed history. Therefore, a more robust reconstruction of watershed history and a better identification of drivers for pressing environmental issues, seems possible under the framework of Shannon's information theory.

Modeling urbanized watershed flood response changes with distributed hydrological model: key hydrological processes, parameterization and case studies

NASA Astrophysics Data System (ADS)

Chen, Y.

2017-12-01

Urbanization is the world development trend for the past century, and the developing countries have been experiencing much rapider urbanization in the past decades. Urbanization brings many benefits to human beings, but also causes negative impacts, such as increasing flood risk. Impact of urbanization on flood response has long been observed, but quantitatively studying this effect still faces great challenges. For example, setting up an appropriate hydrological model representing the changed flood responses and determining accurate model parameters are very difficult in the urbanized or urbanizing watershed. In the Pearl River Delta area, rapidest urbanization has been observed in China for the past decades, and dozens of highly urbanized watersheds have been appeared. In this study, a physically based distributed watershed hydrological model, the Liuxihe model is employed and revised to simulate the hydrological processes of the highly urbanized watershed flood in the Pearl River Delta area. A virtual soil type is then defined in the terrain properties dataset, and its runoff production and routing algorithms are added to the Liuxihe model. Based on a parameter sensitive analysis, the key hydrological processes of a highly urbanized watershed is proposed, that provides insight into the hydrological processes and for parameter optimization. Based on the above analysis, the model is set up in the Songmushan watershed where there is hydrological data observation. A model parameter optimization and updating strategy is proposed based on the remotely sensed LUC types, which optimizes model parameters with PSO algorithm and updates them based on the changed LUC types. The model parameters in Songmushan watershed are regionalized at the Pearl River Delta area watersheds based on the LUC types of the other watersheds. A dozen watersheds in the highly urbanized area of Dongguan City in the Pearl River Delta area were studied for the flood response changes due to urbanization, and the results show urbanization has big impact on the watershed flood responses. The peak flow increased a few times after urbanization which is much higher than previous reports.

Simulating Daily and Sub-daily Water Flow in Large, Semi-arid Watershed Using SWAT: A Case Study of Nueces River Basin, Texas

NASA Astrophysics Data System (ADS)

Bassam, S.; Ren, J.

2015-12-01

Runoff generated during heavy rainfall imposes quick, but often intense, changes in the flow of streams, which increase the chance of flash floods in the vicinity of the streams. Understanding the temporal response of streams to heavy rainfall requires a hydrological model that considers meteorological, hydrological, and geological components of the streams and their watersheds. SWAT is a physically-based, semi-distributed model that is capable of simulating water flow within watersheds with both long-term, i.e. annually and monthly, and short-term (daily and sub-daily) time scales. However, the capability of SWAT in sub-daily water flow modeling within large watersheds has not been studied much, compare to long-term and daily time scales. In this study we are investigating the water flow in a large, semi-arid watershed, Nueces River Basin (NRB) with the drainage area of 16950 mi2 located in South Texas, with daily and sub-daily time scales. The objectives of this study are: (1) simulating the response of streams to heavy, and often quick, rainfall, (2) evaluating SWAT performance in sub-daily modeling of water flow within a large watershed, and (3) examining means for model performance improvement during model calibration and verification based on results of sensitivity and uncertainty analysis. The results of this study can provide important information for water resources planning during flood seasons.

Integrated Modeling System for Analysis of Watershed Water Balance: A Case Study in the Tims Branch Watershed, South Carolina

NASA Astrophysics Data System (ADS)

Setegn, S. G.; Mahmoudi, M.; Lawrence, A.; Duque, N.

2015-12-01

The Applied Research Center at Florida International University (ARC-FIU) is supporting the soil and groundwater remediation efforts of the U.S. Department of Energy (DOE) Savannah River Site (SRS) by developing a surface water model to simulate the hydrology and the fate and transport of contaminants and sediment in the Tims Branch watershed. Hydrological models are useful tool in water and land resource development and decision-making for watershed management. Moreover, simulation of hydrological processes improves understanding of the environmental dynamics and helps to manage and protect water resources and the environment. MIKE SHE, an advanced integrated modeling system is used to simulate the hydrological processes of the Tim Branch watershed with the objective of developing an integrated modeling system to improve understanding of the physical, chemical and biological processes within the Tims Branch watershed. MIKE SHE simulates water flow in the entire land based phase of the hydrological cycle from rainfall to river flow, via various flow processes such as, overland flow, infiltration, evapotranspiration, and groundwater flow. In this study a MIKE SHE model is developed and applied to the Tim branch watershed to study the watershed response to storm events and understand the water balance of the watershed under different climatic and catchment characteristics. The preliminary result of the integrated model indicated that variation in the depth of overland flow highly depend on the amount and distribution of rainfall in the watershed. The ultimate goal of this project is to couple the MIKE SHE and MIKE 11 models to integrate the hydrological component in the land phase of hydrological cycle and stream flow process. The coupled MIKE SHE/MIKE 11 model will further be integrated with an Ecolab module to represent a range of water quality, contaminant transport, and ecological processes with respect to the stream, surface water and groundwater in the Tims Branch watershed at Savannah River Site.

Multi-objective game-theory models for conflict analysis in reservoir watershed management.

PubMed

Lee, Chih-Sheng

2012-05-01

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

Calibration of a Physically-Based Semi-Distributed Hydrologic Model: The Importance of Internal Justification

NASA Astrophysics Data System (ADS)

Tasdighi, A.; Arabi, M.

2014-12-01

Calibration of physically-based distributed hydrologic models has always been a challenging task and subject of controversy in the literature. This study is aimed to investigate how different physiographic characteristics of watersheds call for adaption of the methods used in order to have more robust and internally justifiable simulations. Haw Watershed (1300 sq. mi.) is located in the piedmont region of North Carolina draining into B. Everett Jordan Lake located in west of Raleigh. Major land covers in this watershed are forest (50%), urban/suburban (21%) and agriculture (25%) of which a large portion is pasture. Different hydrologic behaviors are observed in this watershed based on the land use composition and size of the sub-watersheds. Highly urbanized sub-watersheds show flashier hydrographs and near instantaneous hydrologic responses. This is also the case with smaller sub-watersheds with relatively lower percentage of urban areas. The Soil and Water Assessment Tool (SWAT) has been widely used in the literature for hydrologic simulation on daily basis using Soil Conservation Service Curve Number method (SCS CN). However, it has not been used as frequently using the sub-daily routines. In this regard there are a number of studies in the literature which have used coarse time scale (daily) precipitation with methods like SCS CN to calibrate SWAT for watersheds containing different types of land uses and soils reporting satisfying results at the outlet of the watershed. This is while for physically-based distributed models, the more important concern should be to check and analyze the internal processes leading to those results. In this study, the watershed is divided into several sub-watersheds to compare the performance of SCS CN and Green & Ampt (GA) methods on different land uses at different spatial scales. The results suggest better performance of GA compared to SCS CN for smaller and highly urbanized sub-watersheds although GA predominance is not very significant for the latter. Also, the better performance of GA in simulating the peak flows and flashy behavior of the hydrographs is notable. GA did not show a significant improvement over SCS CN in simulating the excess rainfall for larger sub-watersheds.

Ecosystem services of human-dominated watersheds and land use influences: a case study from the Dianchi Lake watershed in China.

PubMed

Hou, Ying; Li, Bo; Müller, Felix; Chen, Weiping

2016-11-01

Watersheds provide multiple ecosystem services. Ecosystem service assessment is a promising approach to investigate human-environment interaction at the watershed scale. The spatial characteristics of ecosystem services are closely related to land use statuses in human-dominated watersheds. This study aims to investigate the effects of land use on the spatial variations of ecosystem services at the Dianchi Lake watershed in Southwest China. We investigated the spatial variations of six ecosystem services-food supply, net primary productivity (NPP), habitat quality, evapotranspiration, water yield, and nitrogen retention. These services were selected based on their significance at the Dianchi Lake watershed and the availability of their data. The quantification of these services was based on modeling, value transference, and spatial analysis in combination with biophysical and socioeconomic data. Furthermore, we calculated the values of ecosystem services provided by different land use types and quantified the correlations between ecosystem service values and land use area proportions. The results show considerable spatial variations in the six ecosystem services associated with land use influences in the Dianchi Lake watershed. The cropland and forest land use types had predominantly positive influences on food productivity and NPP, respectively. The rural residential area and forest land use types reduced and enhanced habitat quality, respectively; these influences were identical to those of evapotranspiration. Urban area and rural residential area exerted significantly positive influences on water yield. In contrast, water yield was negatively correlated with forest area proportion. Finally, cropland and forest had significantly positive and negative influences, respectively, on nitrogen retention. Our study emphasizes the importance of consideration of the influences from land use composition and distribution on ecosystem services for managing the ecosystems of human-dominated watersheds.

Effects of DEM source and resolution on WEPP hydrologic and erosion simulation: A case study of two forest watersheds in northern Idaho

Treesearch

J. X. Zhang; J. Q. Wu; K. Chang; W. J. Elliot; S. Dun

2009-01-01

The recent modification of the Water Erosion Prediction Project (WEPP) model has improved its applicability to hydrology and erosion modeling in forest watersheds. To generate reliable topographic and hydrologic inputs for the WEPP model, carefully selecting digital elevation models (DEMs) with appropriate resolution and accuracy is essential because topography is a...

Linking the Scales of Scientific inquiry and Watershed Management: A Focus on Green Infrastructure

NASA Astrophysics Data System (ADS)

Golden, H. E.; Hoghooghi, N.

2017-12-01

Urbanization modifies the hydrologic cycle, resulting in potentially deleterious downstream water quality and quantity effects. However, the cumulative interacting effects of water storage, transport, and biogeochemical processes occurring within other land cover and use types of the same watershed can render management explicitly targeted to limit the negative outcomes from urbanization ineffective. For example, evidence indicates that green infrastructure, or low impact development (LID), practices can attenuate the adverse water quality and quantity effects of urbanizing systems. However, the research providing this evidence has been conducted at local scales (e.g., plots, small homogeneous urban catchments) that isolate the measurable effects of such approaches. Hence, a distinct disconnect exists between the scale of scientific inquiry and the scale of management and decision-making practices. Here we explore the oft-discussed yet rarely directly addressed scientific and management conundrum: How do we scale our well-documented scientific knowledge of the water quantity and quality responses to LID practices measured and modeled at local scales to that of "actual" management scales? We begin by focusing on LID practices in mixed land cover watersheds. We present key concepts that have emerged from LID research at the local scale, considerations for scaling this research to watersheds, recent advances and findings in scaling the effects of LID practices on water quality and quantity at watershed scales, and the use of combined novel measurements and models for these scaling efforts. We underscore these concepts with a case study that evaluates the effects of three LID practices using simulation modeling across a mixed land cover watershed. This synthesis and case study highlight that scientists are making progress toward successfully tailoring fundamental research questions with decision-making goals in mind, yet we still have a long road ahead.

Spatial and temporal variability of trace element concentrations in an urban subtropical watershed, Honolulu, Hawaii

USGS Publications Warehouse

Heinen, De Carlo E.; Anthony, S.S.

2002-01-01

Trace metal concentrations in soils and in stream and estuarine sediments from a subtropical urban watershed in Hawaii are presented. The results are placed in the context of historical studies of environmental quality (water, soils, and sediment) in Hawaii to elucidate sources of trace elements and the processes responsible for their distribution. This work builds on earlier studies on sediments of Ala Wai Canal of urban Honolulu by examining spatial and temporal variations in the trace elements throughout the watershed. Natural processes and anthropogenic activity in urban Honolulu contribute to spatial and temporal variations of trace element concentrations throughout the watershed. Enrichment of trace elements in watershed soils result, in some cases, from contributions attributed to the weathering of volcanic rocks, as well as to a more variable anthropogenic input that reflects changes in land use in Honolulu. Varying concentrations of As, Cd, Cu, Pb and Zn in sediments reflect about 60 a of anthropogenic activity in Honolulu. Land use has a strong impact on the spatial distribution and abundance of selected trace elements in soils and stream sediments. As noted in continental US settings, the phasing out of Pb-alkyl fuel additives has decreased Pb inputs to recently deposited estuarine sediments. Yet, a substantial historical anthropogenic Pb inventory remains in soils of the watershed and erosion of surface soils continues to contribute to its enrichment in estuarine sediments. Concentrations of other elements (e.g., Cu, Zn, Cd), however, have not decreased with time, suggesting continued active inputs. Concentrations of Ba, Co, Cr, Ni, V and U, although elevated in some cases, typically reflect greater proportions attributed to natural sources rather than anthropogenic input. ?? 2002 Elsevier Science Ltd. All rights reserved.

Watershed reliability, resilience and vulnerability analysis under uncertainty using water quality data.

PubMed

Hoque, Yamen M; Tripathi, Shivam; Hantush, Mohamed M; Govindaraju, Rao S

2012-10-30

A method for assessment of watershed health is developed by employing measures of reliability, resilience and vulnerability (R-R-V) using stream water quality data. Observed water quality data are usually sparse, so that a water quality time-series is often reconstructed using surrogate variables (streamflow). A Bayesian algorithm based on relevance vector machine (RVM) was employed to quantify the error in the reconstructed series, and a probabilistic assessment of watershed status was conducted based on established thresholds for various constituents. As an application example, observed water quality data for several constituents at different monitoring points within the Cedar Creek watershed in north-east Indiana (USA) were utilized. Considering uncertainty in the data for the period 2002-2007, the R-R-V analysis revealed that the Cedar Creek watershed tends to be in compliance with respect to selected pesticides, ammonia and total phosphorus. However, the watershed was found to be prone to violations of sediment standards. Ignoring uncertainty in the water quality time-series led to misleading results especially in the case of sediments. Results indicate that the methods presented in this study may be used for assessing the effects of different stressors over a watershed. The method shows promise as a management tool for assessing watershed health. Copyright © 2012 Elsevier Ltd. All rights reserved.

Development of a Tool for Siting Low Impact Development in Urban Watersheds

NASA Astrophysics Data System (ADS)

Martin-Mikle, C.; de Beurs, K.; Julian, J.

2013-12-01

Low impact development (LID) -- a comprehensive land use planning and design approach with the goal of mitigating development impacts on hydrologic/nutrient cycles and ecosystems -- is increasingly being touted as an effective approach to lessen overland runoff and pollutant loadings. Examples of LIDs include riparian buffers, grassed swales, detention/retention ponds, rain gardens, green roofs and rain barrels. Broad-scale decision support tools for siting LIDs have been developed for agricultural watersheds, but are rare for urban watersheds, largely due to greater land use complexity and lack of necessary high-resolution geospatial data. Here, we develop a framework to assist city planners and water quality managers in siting LIDs in urban watersheds. One key component of this research is a framework accessible to those interested in using it. Hence, development of the framework has centered around 1) determining optimal data requirements for siting LID in an urban watershed and 2) developing a tool compatible with both open-source and commercial GIS software. We employ a wide variety of landscape metrics to evaluate the tool. A case study of the Lake Thunderbird Watershed, an urbanized watershed southeast of Oklahoma City, illustrates the effectiveness of a tool that is capable of siting LID in an urban watershed.

Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication--A Case Study in the Taihu Lake Basin (China).

PubMed

Lin, Chen; Ma, Ronghua; He, Bin

2015-12-24

Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r² was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality.

Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication—A Case Study in the Taihu Lake Basin (China)

PubMed Central

Lin, Chen; Ma, Ronghua; He, Bin

2015-01-01

Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r2 was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality. PMID:26712772

When environmental action does not activate concern: the case of impaired water quality in two rural watersheds.

PubMed

Stough-Hunter, Anjel; Lekies, Kristi S; Donnermeyer, Joseph F

2014-12-01

Little research has considered how residents' perceptions of their local environment may interact with efforts to increase environmental concern, particularly in areas in need of remediation. This study examined the process by which local environmental action may affect environmental concern. A model was presented for exploring the effects of community-based watershed organizations (CWOs) on environmental concern that also incorporates existing perceptions of the local environment. Survey data were collected from area residents in two watersheds in southwestern Pennsylvania, USA, an area affected by abandoned mine drainage. The findings suggest that residents' perceptions of local water quality and importance of improving water quality are important predictors of level of environmental concern and desire for action; however, in this case, having an active or inactive CWO did not influence these perceptions. The implications of these findings raise important questions concerning strategies and policy making around environmental remediation at the local level.

The impact of a prominent rain shadow on flooding in California's Santa Cruz Mountains: A CALJET case study and sensitivity to the ENSO cycle

USGS Publications Warehouse

Ralph, F.M.; Neiman, P.J.; Kingsmill, D.E.; Persson, P.O.G.; White, A.B.; Strem, E.T.; Andrews, E.D.; Antweiler, Ronald C.

2003-01-01

Data from the California Land-Falling Jets Experiment (CALJET) are used to explore the causes of variations in flood severity in adjacent coastal watersheds within the Santa Cruz Mountains on 2-3 February 1998. While Pescadero Creek (rural) experienced its flood of record, the adjacent San Lorenzo Creek (heavily populated), attained only its fourth-highest flow. This difference resulted from conditions present while the warm sector of the storm, with its associated low-level jet, high moisture content, and weak static stability, was overhead. Rainfall in the warm sector was dominated by orographic forcing. While the wind speed strongly modulated rain rates on windward slopes, the wind direction positioned the edge of a rain shadow cast by the Santa Lucia Mountains partially over the San Lorenzo basin, thus protecting the city of Santa Cruz from a more severe flood. Roughly 26% ?? 9% of the streamflow at flood peak on Pescadero Creek resulted from the warm-sector rainfall. Without this rainfall, the peak flow on Pescadero Creek would likely not have attained record status. These results are complemented by a climatological analysis based on ???50-yr-duration streamflow records for these and two other nearby windward watersheds situated ???20 to 40 km farther to the east, and a comparison of this climatological analysis with composites of NCEP-NCAR reanalysis fields. The westernmost watersheds were found to have their greatest floods during El Nin??o winters, while the easternmost watersheds peaked during non-El Nin??o episodes. These results are consistent with the case study, that showed that the composite 925-mb, meridionally oriented wind direction during El Nin??os favors a rain shadow over the eastern watersheds. During non-El Nin??o periods, the composite, zonally oriented wind direction indicates that the sheltering effect of the rain shadow on the eastern watersheds is reduced, while weaker winds, less water vapor, and stronger stratification reduce the peak runoff in the western watersheds relative to El Nin??o periods. These case study and climatological results illustrate the importance of conditions in the moisture-rich warm sector of landfalling Pacific winter storms. Although many other variables can influence flooding, this study shows that variations of ??10?? in wind direction can modulate the location of orographically enhanced floods. While terrain can increase predictability (e.g., rainfall typically increases with altitude), the predictability is reduced when conditions are near a threshold separating different regimes (e.g., in or out of a rain shadow ).

Building multi-country collaboration on watershed ...

EPA Pesticide Factsheets

Community-based watershed resilience programs that bridge public health and environmental outcomes often require cross-boundary, multi-country collaboration. The CRESSIDA project, led by the Regional Environmental Center for Central and Eastern Europe (REC) and supported by the US Environmental Protection Agency (EPA), forwards a resilience-focused approach for Western Balkan communities in the Drini and Drina river watersheds with the goal of safeguarding public health and the environment. The initial phases of this project give a contextualized example of how to advance resilience-driven environmental health goals in Western Balkan communities, and experience within the region has garnered several theme areas that require focus in order to promote a holistic watershed management program. In this paper, using CRESSIDA as a case study, we show (1) how watershed projects designed with resilience-driven environmental health goals can work in context, (2) provide data surrounding contextualized problems with resilience and suggest tools and strategies for the implementation of projects to address these problems, and (3) explore how cross-boundary foci are central to the success of these approaches in watersheds that comprise several countries. Published in the journal, Reviews on Environmental Health.

Large-scale hydrological modeling for calculating water stress indices: implications of improved spatiotemporal resolution, surface-groundwater differentiation, and uncertainty characterization.

PubMed

Scherer, Laura; Venkatesh, Aranya; Karuppiah, Ramkumar; Pfister, Stephan

2015-04-21

Physical water scarcities can be described by water stress indices. These are often determined at an annual scale and a watershed level; however, such scales mask seasonal fluctuations and spatial heterogeneity within a watershed. In order to account for this level of detail, first and foremost, water availability estimates must be improved and refined. State-of-the-art global hydrological models such as WaterGAP and UNH/GRDC have previously been unable to reliably reflect water availability at the subbasin scale. In this study, the Soil and Water Assessment Tool (SWAT) was tested as an alternative to global models, using the case study of the Mississippi watershed. While SWAT clearly outperformed the global models at the scale of a large watershed, it was judged to be unsuitable for global scale simulations due to the high calibration efforts required. The results obtained in this study show that global assessments miss out on key aspects related to upstream/downstream relations and monthly fluctuations, which are important both for the characterization of water scarcity in the Mississippi watershed and for water footprints. Especially in arid regions, where scarcity is high, these models provide unsatisfying results.

Evaluation of Actual Nitrogen Losses From a Watershed Preliminary Results of a Case Study in the Po Vally (Northern Italy)

Treesearch

Maurizio Borin; Tomaso Bisol; Gabriele Bonaiti; Francesco Morari; Devendra M. Amatya

2004-01-01

The evaluation of potential N losses from individual fields is not sufficient to provide an estimate of the actual nitrogen loads reaching the main watercourses and therefore becoming a relevant source of pollution. Along the travel path from a field to the outlet of a watershed several biogeochemical processes may occur, leading to significant changes in the N amount...

A Coupled Approach with Stochastic Rainfall-Runoff Simulation and Hydraulic Modeling for Extreme Flood Estimation on Large Watersheds

NASA Astrophysics Data System (ADS)

Paquet, E.

2015-12-01

The SCHADEX method aims at estimating the distribution of peak and daily discharges up to extreme quantiles. It couples a precipitation probabilistic model based on weather patterns, with a stochastic rainfall-runoff simulation process using a conceptual lumped model. It allows exploring an exhaustive set of hydrological conditions and watershed responses to intense rainfall events. Since 2006, it has been widely applied in France to about one hundred watersheds for dam spillway design, and also aboard (Norway, Canada and central Europe among others). However, its application to large watersheds (above 10 000 km²) faces some significant issues: spatial heterogeneity of rainfall and hydrological processes and flood peak damping due to hydraulic effects (flood plains, natural or man-made embankment) being the more important. This led to the development of an extreme flood simulation framework for large and heterogeneous watersheds, based on the SCHADEX method. Its main features are: Division of the large (or main) watershed into several smaller sub-watersheds, where the spatial homogeneity of the hydro-meteorological processes can reasonably be assumed, and where the hydraulic effects can be neglected. Identification of pilot watersheds where discharge data are available, thus where rainfall-runoff models can be calibrated. They will be parameters donors to non-gauged watersheds. Spatially coherent stochastic simulations for all the sub-watersheds at the daily time step. Identification of a selection of simulated events for a given return period (according to the distribution of runoff volumes at the scale of the main watershed). Generation of the complete hourly hydrographs at each of the sub-watersheds outlets. Routing to the main outlet with hydraulic 1D or 2D models. The presentation will be illustrated with the case-study of the Isère watershed (9981 km), a French snow-driven watershed. The main novelties of this method will be underlined, as well as its perspectives and future improvements.

[Regulation framework of watershed landscape pattern for non-point source pollution control based on 'source-sink' theory: A case study in the watershed of Maluan Bay, Xiamen City, China].

PubMed

Huang, Ning; Wang, Hong Ying; Lin, Tao; Liu, Qi Ming; Huang, Yun Feng; Li, Jian Xiong

2016-10-01

Watershed landscape pattern regulation and optimization based on 'source-sink' theory for non-point source pollution control is a cost-effective measure and still in the exploratory stage. Taking whole watershed as the research object, on the basis of landscape ecology, related theories and existing research results, a regulation framework of watershed landscape pattern for non-point source pollution control was developed at two levels based on 'source-sink' theory in this study: 1) at watershed level: reasonable basic combination and spatial pattern of 'source-sink' landscape was analyzed, and then holistic regulation and optimization method of landscape pattern was constructed; 2) at landscape patch level: key 'source' landscape was taken as the focus of regulation and optimization. Firstly, four identification criteria of key 'source' landscape including landscape pollutant loading per unit area, landscape slope, long and narrow transfer 'source' landscape, pollutant loading per unit length of 'source' landscape along the riverbank were developed. Secondly, nine types of regulation and optimization methods for different key 'source' landscape in rural and urban areas were established, according to three regulation and optimization rules including 'sink' landscape inlay, banding 'sink' landscape supplement, pollutants capacity of original 'sink' landscape enhancement. Finally, the regulation framework was applied for the watershed of Maluan Bay in Xiamen City. Holistic regulation and optimization mode of watershed landscape pattern of Maluan Bay and key 'source' landscape regulation and optimization measures for the three zones were made, based on GIS technology, remote sensing images and DEM model.

Assessment of wildland fire impacts on watershed annual water yield: Analytical framework and case studies in the United States

DOE PAGES

Hallema, Dennis W.; Sun, Ge; Caldwell, Peter V.; ...

2016-11-29

More than 50% of water supplies in the conterminous United States originate on forestland or rangeland and are potentially under increasing stress as a result of larger and more severe wildfires. Little is known, however, about the long-term impacts of fire on annual water yield and the role of climate variability within this context. We here propose a framework for evaluating wildland fire impacts on streamflow that combines double-mass analysis with new methods (change point analysis, climate elasticity modeling, and process-based modeling) to distinguish between multiyear fire and climate impacts. The framework captures a wide range of fire types, watershedsmore » characteristics, and climate conditions using streamflow data, as opposed to other approaches requiring paired watersheds. The process is illustrated with three case studies. A watershed in Arizona experienced a +266% increase in annual water yield in the 5 years after a wildfire, where +219% was attributed to wildfire and +24% to precipitation trends. In contrast, a California watershed had a lower (–64%) post-fire net water yield, comprised of enhanced flow (+38%) attributed to wildfire offset (–102%) by lower precipitation in the post-fire period. Changes in streamflow within a watershed in South Carolina had no apparent link to periods of prescribed burning but matched a very wet winter and reports of storm damage. As a result, the presented framework is unique in its ability to detect and quantify fire or other disturbances, even if the date or nature of the disturbance event is uncertain, and regardless of precipitation trends.« less

Assessment of wildland fire impacts on watershed annual water yield: Analytical framework and case studies in the United States

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

Hallema, Dennis W.; Sun, Ge; Caldwell, Peter V.

More than 50% of water supplies in the conterminous United States originate on forestland or rangeland and are potentially under increasing stress as a result of larger and more severe wildfires. Little is known, however, about the long-term impacts of fire on annual water yield and the role of climate variability within this context. We here propose a framework for evaluating wildland fire impacts on streamflow that combines double-mass analysis with new methods (change point analysis, climate elasticity modeling, and process-based modeling) to distinguish between multiyear fire and climate impacts. The framework captures a wide range of fire types, watershedsmore » characteristics, and climate conditions using streamflow data, as opposed to other approaches requiring paired watersheds. The process is illustrated with three case studies. A watershed in Arizona experienced a +266% increase in annual water yield in the 5 years after a wildfire, where +219% was attributed to wildfire and +24% to precipitation trends. In contrast, a California watershed had a lower (–64%) post-fire net water yield, comprised of enhanced flow (+38%) attributed to wildfire offset (–102%) by lower precipitation in the post-fire period. Changes in streamflow within a watershed in South Carolina had no apparent link to periods of prescribed burning but matched a very wet winter and reports of storm damage. As a result, the presented framework is unique in its ability to detect and quantify fire or other disturbances, even if the date or nature of the disturbance event is uncertain, and regardless of precipitation trends.« less

Estimating Precipitation Input to a Watershed by Combining Gauge and Radar Derived Observations

NASA Astrophysics Data System (ADS)

Ercan, M. B.; Goodall, J. L.

2011-12-01

One challenge in creating an accurate watershed model is obtaining estimates of precipitation intensity over the watershed area. While precipitation measurements are generally available from gauging stations and radar instruments, both of these approaches for measuring precipitation have strengths and weakness. A typical way of addressing this challenge is to use gauged precipitation estimates to calibrate radar based estimates, however this study proposes a slightly different approach in which the optimal daily precipitation value is selected from either the gauged or the radar estimates based on the observed streamflow for that day. Our proposed approach is perhaps most relevant for cases of modeling watersheds that do not have a nearby precipitation gauge, or for regions that experience convective storms that are often highly spatially variable. Using the Eno River watershed located in Orange County, NC, three different precipitation datasets were created to predict streamflow at the watershed outlet for the time period 2005-2010 using the Soil and Water Assessment Tool (SWAT): (1) estimates based on only precipitation gauging stations, (2) estimates based only on gauged-corrected radar observations, and (3) the combination of precipitation estimates from the gauge and radar data determined using our proposed approach. The results show that the combined precipitation approach significantly improves streamflow predictions (Nash-Sutcliffe Coefficient, E = 0.66) when compared to the gauged estimates alone (E = 0.47) and the radar based estimates alone (E = 0.45). Our study was limited to one watershed, therefore additional studies are needed to control for factors such as climate, ecology, and hydrogeology that will likely influence the results of the analysis.

Stormwater management network effectiveness and implications for urban watershed function: A critical review

USGS Publications Warehouse

Jefferson, Anne J.; Bhaskar, Aditi S.; Hopkins, Kristina G.; Fanelli, Rosemary; Avellaneda, Pedro M.; McMillan, Sara K.

2017-01-01

Deleterious effects of urban stormwater are widely recognized. In several countries, regulations have been put into place to improve the conditions of receiving water bodies, but planning and engineering of stormwater control is typically carried out at smaller scales. Quantifying cumulative effectiveness of many stormwater control measures on a watershed scale is critical to understanding how small-scale practices translate to urban river health. We review 100 empirical and modelling studies of stormwater management effectiveness at the watershed scale in diverse physiographic settings. Effects of networks with stormwater control measures (SCMs) that promote infiltration and harvest have been more intensively studied than have detention-based SCM networks. Studies of peak flows and flow volumes are common, whereas baseflow, groundwater recharge, and evapotranspiration have received comparatively little attention. Export of nutrients and suspended sediments have been the primary water quality focus in the United States, whereas metals, particularly those associated with sediments, have received greater attention in Europe and Australia. Often, quantifying cumulative effects of stormwater management is complicated by needing to separate its signal from the signal of urbanization itself, innate watershed characteristics that lead to a range of hydrologic and water quality responses, and the varying functions of multiple types of SCMs. Biases in geographic distribution of study areas, and size and impervious surface cover of watersheds studied also limit our understanding of responses. We propose hysteretic trajectories for how watershed function responds to increasing imperviousness and stormwater management. Even where impervious area is treated with SCMs, watershed function may not be restored to its predevelopment condition because of the lack of treatment of all stormwater generated from impervious surfaces; non-additive effects of individual SCMs; and persistence of urban effects beyond impervious surfaces. In most cases, pollutant load decreases largely result from run-off reductions rather than lowered solute or particulate concentrations. Understanding interactions between natural and built landscapes, including stormwater management strategies, is critical for successfully managing detrimental impacts of stormwater at the watershed scale.

GIS-based spatial regression and prediction of water quality in river networks: A case study in Iowa

USGS Publications Warehouse

Yang, X.; Jin, W.

2010-01-01

Nonpoint source pollution is the leading cause of the U.S.'s water quality problems. One important component of nonpoint source pollution control is an understanding of what and how watershed-scale conditions influence ambient water quality. This paper investigated the use of spatial regression to evaluate the impacts of watershed characteristics on stream NO3NO2-N concentration in the Cedar River Watershed, Iowa. An Arc Hydro geodatabase was constructed to organize various datasets on the watershed. Spatial regression models were developed to evaluate the impacts of watershed characteristics on stream NO3NO2-N concentration and predict NO3NO2-N concentration at unmonitored locations. Unlike the traditional ordinary least square (OLS) method, the spatial regression method incorporates the potential spatial correlation among the observations in its coefficient estimation. Study results show that NO3NO2-N observations in the Cedar River Watershed are spatially correlated, and by ignoring the spatial correlation, the OLS method tends to over-estimate the impacts of watershed characteristics on stream NO3NO2-N concentration. In conjunction with kriging, the spatial regression method not only makes better stream NO3NO2-N concentration predictions than the OLS method, but also gives estimates of the uncertainty of the predictions, which provides useful information for optimizing the design of stream monitoring network. It is a promising tool for better managing and controlling nonpoint source pollution. ?? 2010 Elsevier Ltd.

Impacts of Land Use Change on the Natural Flow Regime: A Case Study in the Meramec River Watershed in Eastern Missouri, USA

NASA Astrophysics Data System (ADS)

Wu, C. L.; Knouft, J.; Chu, M.

2017-12-01

The natural flow regime within a watershed can be considered as the expected temporal patterns of streamflow variation in the absence of human impacts. While ecosystems have evolved to function under these conditions, the natural flow regime of most rivers has been significantly altered by human activities. Land use change, including the development of agriculture and urbanization, is a primary cause of the loss of natural flow regimes. These changes have altered discharge volume, timing, and variability, and consequently affected the structure and functioning of river ecosystems. The Meramec River watershed is located in east central Missouri and changes in land use have been the primary factor impacting flow regimes across the watershed. In this study, a watershed model, the Soil and Water Assessment Tool (SWAT), was developed to simulate a long-term time series of streamflow (1978-2014) within the watershed. Model performance was evaluated using statistical metrics and graphical technique including R-squared, Nash-Sutcliffe efficiency, cumulative error, and 1:1-ratio comparison between observed and simulated variables. The calibrated and validated SWAT model was then used to quantify the responses of the watershed when it was a forested natural landscape. An Indicator of Hydrologic Alteration (IHA) approach was applied to characterize the flow regime under the current landcover conditions as well as the simulated natural flow regime under the no land use change scenario. Differences in intra- and inter-annual ecologically relevant flow metrics were then compared using SWAT model outputs in conjunction with the IHA approach based on model outputs from current and no land use change conditions. This study provides a watershed-scale understanding of effects of land use change on a river's flow variability and provides a framework for the development of restoration plans for heavily altered watersheds.

Valuing the effects of hydropower development on watershed ecosystem services: Case studies in the Jiulong River Watershed, Fujian Province, China

NASA Astrophysics Data System (ADS)

Wang, Guihua; Fang, Qinhua; Zhang, Luoping; Chen, Weiqi; Chen, Zhenming; Hong, Huasheng

2010-02-01

Hydropower development brings many negative impacts on watershed ecosystems which are not fully integrated into current decision-making largely because in practice few accept the cost and benefit beyond market. In this paper, a framework was proposed to valuate the effects on watershed ecosystem services caused by hydropower development. Watershed ecosystem services were classified into four categories of provisioning, regulating, cultural and supporting services; then effects on watershed ecosystem services caused by hydropower development were identified to 21 indicators. Thereafter various evaluation techniques including the market value method, opportunity cost approach, project restoration method, travel cost method, and contingent valuation method were determined and the models were developed to valuate these indicators reflecting specific watershed ecosystem services. This approach was applied to three representative hydropower projects (Daguan, Xizaikou and Tiangong) of Jiulong River Watershed in southeast China. It was concluded that for hydropower development: (1) the value ratio of negative impacts to positive benefits ranges from 64.09% to 91.18%, indicating that the negative impacts of hydropower development should be critically studied during its environmental administration process; (2) the biodiversity loss and water quality degradation (together accounting for 80-94%) are the major negative impacts on watershed ecosystem services; (3) the average environmental cost per unit of electricity is up to 0.206 Yuan/kW h, which is about three quarters of its on-grid power tariff; and (4) the current water resource fee accounts for only about 4% of its negative impacts value, therefore a new compensatory method by paying for ecosystem services is necessary for sustainable hydropower development. These findings provide a clear picture of both positive and negative effects of hydropower development for decision-makers in the monetary term, and also provide a basis for further design of environmental instrument such as payment for watershed ecosystem services.

Quality of water and antibiotic resistance of Escherichia coli from water sources of hilly tribal villages with and without integrated watershed management-a one year prospective study.

PubMed

Nerkar, Sandeep S; Tamhankar, Ashok J; Khedkar, Smita U; Lundborg, Cecilia Stålsby

2014-06-01

In many hilly tribal areas of the world, water scarcity is a major problem and diarrhoea is common. Poor quality of water also affects the environment. An integrated watershed management programme (IWMP) aims to increase availability of water and to improve life conditions. Globally, there is a lack of information on water contamination, occurrence of diarrhoea and antibiotic resistance, a serious global concern, in relation to IWMP in hilly tribal areas. Therefore, a prospective observational study was conducted during 2011–2012 in six villages in a hilly tribal belt of India, three with and three without implementation of an IWMP, to explore quality of water, diarrhoeal cases in the community and antibiotic resistance of Escherichia coli from water sources. The results showed that physico-chemical quality of water was within limits of safe consumption in all samples. The odds of coliform contamination in water samples was 2.3 times higher in non-watershed management villages (NWMV) compared to integrated watershed management villages (IWMV) (95% CI 0.8–6.45, p = 0.081). The number of diarrhoeal cases (18/663 vs. 42/639, p < 0.05) was lower in IWMV as compared to NWMV. Overall E. coli isolates showed high susceptibility to antibiotics. Resistance to a wider range of antibiotics was observed in NWMV.

Quality of Water and Antibiotic Resistance of Escherichia coli from Water Sources of Hilly Tribal Villages with and without Integrated Watershed Management—A One Year Prospective Study

PubMed Central

Nerkar, Sandeep S.; Tamhankar, Ashok J.; Khedkar, Smita U.; Stålsby Lundborg, Cecilia

2014-01-01

In many hilly tribal areas of the world, water scarcity is a major problem and diarrhoea is common. Poor quality of water also affects the environment. An integrated watershed management programme (IWMP) aims to increase availability of water and to improve life conditions. Globally, there is a lack of information on water contamination, occurrence of diarrhoea and antibiotic resistance, a serious global concern, in relation to IWMP in hilly tribal areas. Therefore, a prospective observational study was conducted during 2011–2012 in six villages in a hilly tribal belt of India, three with and three without implementation of an IWMP, to explore quality of water, diarrhoeal cases in the community and antibiotic resistance of Escherichia coli from water sources. The results showed that physico-chemical quality of water was within limits of safe consumption in all samples. The odds of coliform contamination in water samples was 2.3 times higher in non-watershed management villages (NWMV) compared to integrated watershed management villages (IWMV) (95% CI 0.8–6.45, p = 0.081). The number of diarrhoeal cases (18/663 vs. 42/639, p < 0.05) was lower in IWMV as compared to NWMV. Overall E. coli isolates showed high susceptibility to antibiotics. Resistance to a wider range of antibiotics was observed in NWMV. PMID:24991664

The relationship of nitrate concentrations in streams to row crop land use in Iowa

USGS Publications Warehouse

Schilling, K.E.; Libra, R.D.

2000-01-01

The relationship between row crop land use and nitrate N concentrations in surface water was evaluated for 15 Iowa watersheds ranging from 1002 to 2774 km2 and 10 smaller watersheds ranging from 47 to 775 km2 for the period 1996 to 1998. The percentage of land in row crop varied from 24 to >87% in the 15 large watersheds, and mean annual NO3-N concentrations ranged from 0.5 to 10.8 mg/L. In the small watersheds, row crop percentage varied from 28 to 87% and mean annual NO3-N concentrations ranged from 3.0 to 10.5 mg/L. In both cases, nitrate N concentrations were directly related to the percentage of row crop in the watershed (p 87% in the 15 large watersheds, and mean annual NO3-N concentrations ranged from 0.5 to 10.8 mg/L. In the small watersheds, row crop percentage varied from 28 to 87% and mean annual NO3-N concentrations ranged from 3.0 to 10.5 mg/L. In both cases, nitrate N concentrations were directly related to the percentage of row crop in the watershed (p<0.0003). Linear regression showed similar slope for both sets of watersheds (0.11) suggesting that average annual surface water nitrate concentrations in Iowa, and possibly similar agricultural areas in the midwestern USA, can be approximated by multiplying a watershed's row crop percentage by 0.1. Comparing the Iowa watershed data with similar data collected at a subwatershed scale in Iowa (0.1 to 8.1 km2) and a larger midcontinent scale (7300 to 237 100 km2) suggests that watershed scale affects the relationship of nitrate concentration and land use. The slope of nitrate concentration versus row crop percentage decreases with increasing watershed size.Mean nitrate concentrations and row crop land use were summarized for 15 larger and ten smaller watersheds in Iowa, and the relationship between NO3 concentration and land use was examined. Linear regression of mean NO3 concentration and percent row crop was highly significant for both sets of watershed data, but a stronger correlation was noted in the small-watershed data. Both data sets suggested that mean annual surface-water NO3 concentrations in the state could be approximated by multiplying the watershed's percent row crop by 0.1. The slope of NO3 concentration versus row crop percentage appeared to decrease with increasing watershed size.

Minimum forest cover required for sustainable water flow regulation of a watershed: a case study in Jambi Province, Indonesia

NASA Astrophysics Data System (ADS)

Tarigan, Suria; Wiegand, Kerstin; Sunarti; Slamet, Bejo

2018-01-01

In many tropical regions, the rapid expansion of monoculture plantations has led to a sharp decline in forest cover, potentially degrading the ability of watersheds to regulate water flow. Therefore, regional planners need to determine the minimum proportion of forest cover that is required to support adequate ecosystem services in these watersheds. However, to date, there has been little research on this issue, particularly in tropical areas where monoculture plantations are expanding at an alarming rate. Therefore, in this study, we investigated the influence of forest cover and oil palm (Elaeis guineensis) and rubber (Hevea brasiliensis) plantations on the partitioning of rainfall into direct runoff and subsurface flow in a humid, tropical watershed in Jambi Province, Indonesia. To do this, we simulated streamflow with a calibrated Soil and Water Assessment Tool (SWAT) model and observed several watersheds to derive the direct runoff coefficient (C) and baseflow index (BFI). The model had a strong performance, with Nash-Sutcliffe efficiency values of 0.80-0.88 (calibration) and 0.80-0.85 (validation) and percent bias values of -2.9-1.2 (calibration) and 7.0-11.9 (validation). We found that the percentage of forest cover in a watershed was significantly negatively correlated with C and significantly positively correlated with BFI, whereas the rubber and oil palm plantation cover showed the opposite pattern. Our findings also suggested that at least 30 % of the forest cover was required in the study area for sustainable ecosystem services. This study provides new adjusted crop parameter values for monoculture plantations, particularly those that control surface runoff and baseflow processes, and it also describes the quantitative association between forest cover and flow indicators in a watershed, which will help regional planners in determining the minimum proportion of forest and the maximum proportion of plantation to ensure that a watershed can provide adequate ecosystem services.

Evaluating integrated watershed management using multiple criteria analysis--a case study at Chittagong Hill Tracts in Bangladesh.

PubMed

Biswas, Shampa; Vacik, Harald; Swanson, Mark E; Haque, S M Sirajul

2012-05-01

Criteria and indicators assessment is one of the ways to evaluate management strategies for mountain watersheds. One framework for this, Integrated Watershed Management (IWM), was employed at Chittagong Hill Tracts region of Bangladesh using a multi-criteria analysis approach. The IWM framework, consisting of the design and application of principles, criteria, indicators, and verifiers (PCIV), facilitates active participation by diverse professionals, experts, and interest groups in watershed management, to explicitly address the demands and problems to measure the complexity of problems in a transparent and understandable way. Management alternatives are developed to fulfill every key component of IWM considering the developed PCIV set and current situation of the study area. Different management strategies, each focusing on a different approach (biodiversity conservation, flood control, soil and water quality conservation, indigenous knowledge conservation, income generation, watershed conservation, and landscape conservation) were assessed qualitatively on their potential to improve the current situation according to each verifier of the criteria and indicator set. Analytic Hierarchy Process (AHP), including sensitivity analysis, was employed to identify an appropriate management strategy according to overall priorities (i.e., different weights of each principle) of key informants. The AHP process indicated that a strategy focused on conservation of biodiversity provided the best option to address watershed-related challenges in the Chittagong Hill Tracts, Bangladesh.

Observation des influences du changement du couvert forestier sur le comportement hydrologique de grands bassins versants tropicaux a l'aide de la teledetection numerique: Cas du bassin versant de Dong Nai, Viet Nam

NASA Astrophysics Data System (ADS)

Pham, Trinh Hung

Monitoring hydrological behavior of a large tropical watershed following a forest cover variation has an important role in water resource management planning as well as for forest sustainable management. Traditional methods in forest hydrology studies are Experimental watersheds, Upstream-downstream, Experimental plots, Statistical regional analysis and Watershed simulation. Those methodes have limitations for large watersheds concerning the monitoring time, the lack of input data especially about forest cover and the capacity of extrapolating results accurately in terms of large watersheds. Moreover, there is still currently a scientific debate in forest ecology on relation between water and forest. The reason of this problem comes from geographical differences in publication concerning study zones, experimental watershed size and applied methods. It gives differences in the conclusions on the influence of tropical forest cover change on the changes of outlet water and yet on the yearly runoff in terms of large watershed. In order to exceed the limitations of actual methods, to solve the difficulty of acquiring forest cover data and to have a better understanding of the relation between tropical forest cover change and hydrological behavior evolution of a large watershed, it is necessary to develop a new approach by using numeric remote sensing. We used the watershed of Dong Nai as a case study. Results show that a fusion between TM and ETM+ Landsat image series and hydro-meteorologic data allow us to observe and detect flooding trends and flooding peaks after an intensive forest cover change from 16% to 20%. Flooding frequency and flooding peaks have clearly decreased when there is an increase of the forest cover from 1983 to 1990. The influence of tropical forest cover on the hydrological behavior is varying with geographical locations of watershed. There is a significant relation between forest cover evolution and environmental facteurs as the runoff coefficient (R = 0,87) and the yearly precipitation (R = 0,93).

Watershed microinfarct pathology and cognition in older persons.

PubMed

Kapasi, Alifiya; Leurgans, Sue E; James, Bryan D; Boyle, Patricia A; Arvanitakis, Zoe; Nag, Sukriti; Bennett, David A; Buchman, Aron S; Schneider, Julie A

2018-05-30

Brain microinfarcts are common in aging and are associated with cognitive impairment. Anterior and posterior watershed border zones lie at the territories of the anterior, middle, and posterior cerebral arteries, and are more vulnerable to hypoperfusion than brain regions outside the watershed areas. However, little is known about microinfarcts in these regions and how they relate to cognition in aging. Participants from the Rush Memory and Aging Project, a community-based clinical-pathologic study of aging, underwent detailed annual cognitive evaluations. We examined 356 consecutive autopsy cases (mean age-at-death, 91 years [SD = 6.16]; 28% men) for microinfarcts from 3 watershed brain regions (2 anterior and 1 posterior) and 8 brain regions outside the watershed regions. Linear regression models were used to examine the association of cortical watershed microinfarcts with cognition, including global cognition and 5 cognitive domains. Microinfarcts in any region were present in 133 (37%) participants, of which 50 had microinfarcts in watershed regions. Persons with multiple microinfarcts in cortical watershed regions had lower global cognition (estimate = -0.56, standard error (SE) = 0.26, p = 0.03) and lower cognitive function in the specific domains of working memory (estimate = -0.58, SE = 0.27, p = 0.03) and visuospatial abilities (estimate = -0.57, SE = 0.27, p = 0.03), even after controlling for microinfarcts in other brain regions, demographics, and age-related pathologies. Neither the presence nor multiplicity of microinfarcts in brain regions outside the cortical watershed regions were related to global cognition or any of the 5 cognitive domains. These findings suggest that multiple microinfarcts in watershed regions contribute to age-related cognitive impairment. Copyright © 2018 Elsevier Inc. All rights reserved.

[New paradigm for soil and water conservation: a method based on watershed process modeling and scenario analysis].

PubMed

Zhu, A-Xing; Chen, La-Jiao; Qin, Cheng-Zhi; Wang, Ping; Liu, Jun-Zhi; Li, Run-Kui; Cai, Qiang-Guo

2012-07-01

With the increase of severe soil erosion problem, soil and water conservation has become an urgent concern for sustainable development. Small watershed experimental observation is the traditional paradigm for soil and water control. However, the establishment of experimental watershed usually takes long time, and has the limitations of poor repeatability and high cost. Moreover, the popularization of the results from the experimental watershed is limited for other areas due to the differences in watershed conditions. Therefore, it is not sufficient to completely rely on this old paradigm for soil and water loss control. Recently, scenario analysis based on watershed modeling has been introduced into watershed management, which can provide information about the effectiveness of different management practices based on the quantitative simulation of watershed processes. Because of its merits such as low cost, short period, and high repeatability, scenario analysis shows great potential in aiding the development of watershed management strategy. This paper elaborated a new paradigm using watershed modeling and scenario analysis for soil and water conservation, illustrated this new paradigm through two cases for practical watershed management, and explored the future development of this new soil and water conservation paradigm.

Observing, studying, and managing for change: Proceedings of the Fourth Interagency Conference on Research in the Watersheds

USGS Publications Warehouse

Medley, C. Nicholas; Patterson, Glenn; Parker, Melanie J.

2011-01-01

These proceedings contain the abstracts, manuscripts, and posters of presentations given at the Fourth Interagency Conference on Research in the Watersheds—Observing, Studying, and Managing for Change, held at the Westmark Hotel in Fairbanks, Alaska, September 26–30, 2011. The conference was jointly hosted by the Bureau of Land Management and the National Park Service.Watersheds face resource impacts driven by accelerated change related to land use, population, and climate. About every three years a conference is held to bring together watershed researchers, observers, and managers to share scientific advances and management strategies. This year, the Fourth ICRW took a wider perspective on watershed science and examined some pressing issues of watershed science and management in our largest and perhaps most vulnerable state, Alaska. The purpose of the conference was to better understand the processes driving change and help managers incorporate societal needs and scientific uncertainty in the management of natural resources.The conference echoed similar themes to the last, highlighting the challenges of managing watersheds based on available science when considerably uncertainty remains regarding the hypothesized relationships between observed environmental changes and their ultimate effects. For example, while the scientific case for anthropogenic climate change has been well presented, confirming possible cause and effect relationships between climatic change and physical and ecological impacts in highly variable, natural systems continues to represent a scientific challenge. This goal becomes even more difficult when superimposed upon a long history of natural resource and land management practices that have fundamentally changed the physical, chemical and biological processes important in maintaining naturally functioning ecosystems. Designing and implementing studies to better understand watersheds and clearly communicating the findings to decisionmakers will be the primary challenge for natural resource scientists and managers into the foreseeable future.

Managing the space-time-load continuum in TMDL planning: a case study for understanding groundwaer loads through advanced mapping techniques

Treesearch

Phillip Harte; Marcel Belaval; Andrea Traviglia

2016-01-01

The lag time between groundwater recharge and discharge in a watershed and the potential groundwater load to streams is an important factor in forecasting responses to future land use practices. We call this concept managing the “space-time-load continuum.” It’s understood that in any given watershed, the response function (the load at any given time) will differ for...

KINEROS2-AGWA: Model Use, Calibration, and Validation

NASA Technical Reports Server (NTRS)

Goodrich, D C.; Burns, I. S.; Unkrich, C. L.; Semmens, D. J.; Guertin, D. P.; Hernandez, M.; Yatheendradas, S.; Kennedy, J. R.; Levick, L. R..

2013-01-01

KINEROS (KINematic runoff and EROSion) originated in the 1960s as a distributed event-based model that conceptualizes a watershed as a cascade of overland flow model elements that flow into trapezoidal channel model elements. KINEROS was one of the first widely available watershed models that interactively coupled a finite difference approximation of the kinematic overland flow equations to a physically based infiltration model. Development and improvement of KINEROS continued from the 1960s on a variety of projects for a range of purposes, which has resulted in a suite of KINEROS-based modeling tools. This article focuses on KINEROS2 (K2), a spatially distributed, event-based watershed rainfall-runoff and erosion model, and the companion ArcGIS-based Automated Geospatial Watershed Assessment (AGWA) tool. AGWA automates the time-consuming tasks of watershed delineation into distributed model elements and initial parameterization of these elements using commonly available, national GIS data layers. A variety of approaches have been used to calibrate and validate K2 successfully across a relatively broad range of applications (e.g., urbanization, pre- and post-fire, hillslope erosion, erosion from roads, runoff and recharge, and manure transport). The case studies presented in this article (1) compare lumped to stepwise calibration and validation of runoff and sediment at plot, hillslope, and small watershed scales; and (2) demonstrate an uncalibrated application to address relative change in watershed response to wildfire.

KINEROS2/AGWA: Model use, calibration and validation

USGS Publications Warehouse

Goodrich, D.C.; Burns, I.S.; Unkrich, C.L.; Semmens, Darius J.; Guertin, D.P.; Hernandez, M.; Yatheendradas, S.; Kennedy, Jeffrey R.; Levick, Lainie R.

2012-01-01

KINEROS (KINematic runoff and EROSion) originated in the 1960s as a distributed event-based model that conceptualizes a watershed as a cascade of overland flow model elements that flow into trapezoidal channel model elements. KINEROS was one of the first widely available watershed models that interactively coupled a finite difference approximation of the kinematic overland flow equations to a physically based infiltration model. Development and improvement of KINEROS continued from the 1960s on a variety of projects for a range of purposes, which has resulted in a suite of KINEROS-based modeling tools. This article focuses on KINEROS2 (K2), a spatially distributed, event-based watershed rainfall-runoff and erosion model, and the companion ArcGIS-based Automated Geospatial Watershed Assessment (AGWA) tool. AGWA automates the time-consuming tasks of watershed delineation into distributed model elements and initial parameterization of these elements using commonly available, national GIS data layers. A variety of approaches have been used to calibrate and validate K2 successfully across a relatively broad range of applications (e.g., urbanization, pre- and post-fire, hillslope erosion, erosion from roads, runoff and recharge, and manure transport). The case studies presented in this article (1) compare lumped to stepwise calibration and validation of runoff and sediment at plot, hillslope, and small watershed scales; and (2) demonstrate an uncalibrated application to address relative change in watershed response to wildfire.

Multiple Pathways to Bacterial Load Reduction by Stormwater Best Management Practices: Trade-Offs in Performance, Volume, and Treated Area.

PubMed

Wolfand, Jordyn M; Bell, Colin D; Boehm, Alexandria B; Hogue, Terri S; Luthy, Richard G

2018-06-05

Stormwater best management practices (BMPs) are implemented to reduce microbial pollution in runoff, but their removal efficiencies differ. Enhanced BMPs, such as those with media amendments, can increase removal of fecal indicator bacteria (FIB) in runoff from 0.25-log 10 to above 3-log 10 ; however, their implications for watershed-scale management are poorly understood. In this work, a computational model was developed to simulate watershed-scale bacteria loading and BMP performance using the Ballona Creek Watershed (Los Angeles County, CA) as a case study. Over 1400 scenarios with varying BMP performance, percent watershed area treated, BMP treatment volume, and infiltrative capabilities were simulated. Incremental improvement of BMP performance by 0.25-log 10 , while keeping other scenario variables constant, reduces annual bacterial load at the outlet by a range of 0-29%. In addition, various simulated scenarios provide the same FIB load reduction; for example, 75% load reduction is achieved by diverting runoff from either 95% of the watershed area to 25 000 infiltrating BMPs with 0.5-log 10 removal or 75% of the watershed area to 75 000 infiltrating BMPs with 1.5-log 10 removal. Lastly, simulated infiltrating BMPs provide greater FIB reduction than noninfiltrating BMPs at the watershed scale. Results provide new insight on the trade-offs between BMP treatment volume, performance, and distribution.

Improved hydrological modeling using AGWA; incorporation of different management practices in hydrological modeling.

NASA Astrophysics Data System (ADS)

Vithanage, J.; Miller, S. N.; Paige, G. B.; Liu, T.

2017-12-01

We present a novel way to simulate the effects of rangeland management decisions in a GIS-based hydrologic modeling toolkit. We have implemented updates to the Automated Geospatial Watershed Assessment tool (AGWA) in which a landscape can be broken into management units (e.g., high intensity grazing, low intensity grazing, fire management, and unmanaged), each of which is assigned a different hydraulic conductivity (Ks) parameter in KINEmatic Runoff and EROSion model (KINEROS2). These updates are designed to provide modeling support to land managers tasked with rangeland watershed management planning and/or monitoring, and evaluation of water resources management. Changes to hydrologic processes and resulting hydrographs and sedigraphs are simulated within the AGWA framework. Case studies are presented in which a user selects various management scenarios and design storms, and the model identifies areas that become susceptible to change as a consequence of management decisions. The baseline (unmanaged) scenario is built using commonly available GIS data, after which the watershed is subdivided into management units. We used an array of design storms with various return periods and frequencies to evaluate the impact of management practices while changing the scale of watershed. Watershed parameters governing interception, infiltration, and surface runoff were determined with the aid of literature published on research studies carried out in the Walnut Gulch Experimental Watershed in southeast Arizona. We observed varied, but significant changes in hydrological responses (runoff) with different management practices as well with varied scales of watersheds. Results show that the toolkit can be used to quantify potential hydrologic change as a result of unitized land use decision-making.

Aquatic Trophic Productivity model: A decision support model for river restoration planning in the Methow River, Washington

USGS Publications Warehouse

Benjamin, Joseph R.; Bellmore, J. Ryan

2016-05-19

In this report, we outline the structure of a stream food-web model constructed to explore how alternative river restoration strategies may affect stream fish populations. We have termed this model the “Aquatic Trophic Productivity model” (ATP). We present the model structure, followed by three case study applications of the model to segments of the Methow River watershed in northern Washington. For two case studies (middle Methow River and lower Twisp River floodplain), we ran a series of simulations to explore how food-web dynamics respond to four distinctly different, but applied, strategies in the Methow River watershed: (1) reconnection of floodplain aquatic habitats, (2) riparian vegetation planting, (3) nutrient augmentation (that is, salmon carcass addition), and (4) enhancement of habitat suitability for fish. For the third case study, we conducted simulations to explore the potential fish and food-web response to habitat improvements conducted in 2012 at the Whitefish Island Side Channel, located in the middle Methow River.

Modeling Fate and Transport of Fecal Coliform Bacteria Using SWAT 2005 (Case Study: Jajrood River Watershed, Iran)

NASA Astrophysics Data System (ADS)

Maghrebi, M.; Tajrishy, M.

2010-12-01

Jajrood River watershed is one of the main drinking water resources of the capital city of Tehran, Iran. In addition it has been available as many recreational usages especially in the warm months. As a result of being located near one of the crowded cities of the world, a variety of microbial pollutions is commonly perceived in the Jajrood River. Among them, there are strong concerns about fecal coliform bacteria concentration. This article aimed to model fate and transport of fecal coliform bacteria in Jajrood River watershed using Soil and Water Assessment Tool (SWAT) model version 2005. Potential pollutant sources in the study area were detected and quantified for modeling purposes. In spite of being lack of knowledge about bacteria die-off rate in small river bodies, as well as in other watershed-based forms, fecal coliform bacteria die-off rates were estimated using both laboratory and field data investigations with some simplifications. The SWAT model was calibrated over an extended time period (1997-2002) for this watershed. The river flow calibrated using SUFI-2 software and resulted in a very good outputs (R2=0.82, E=0.81). Furthermore SWAT model was validated over January 2003 to September 2005 in the study area and has resulted in good outputs (R2=0.61, E=0.57). This research illustrates SWAT 2005 capability to model fecal coliform bacteria in a populated watershed, and deals with most of watershed microbial pollution sources that are usually observed in developing countries. Fecal coliform concentration simulation results were mostly in the same order in comparison with real data. However, Differences were judged to be related to lack of input data. In this article different aspects of SWAT capabilities for modeling of fecal coliform bacteria concentration will be reviewed and it will present new insights in bacteria modeling procedures especially for mountainous, high populated and small sized watersheds.

The assessment of land use change impact on watersheds runoff using SWAT: case study of Urmia Lake in Iran

NASA Astrophysics Data System (ADS)

Jabbari, Anahita; Jarihani, Ben; Rezaie, Hossein

2015-04-01

Lake Urmia, long counted among the world's largest saltwater lakes, contains only 5% of the amount of water it did just 20 years ago. The decline is generally blamed on a combination of drought, increased water diversion for irrigated agriculture within the lake's watershed and land use mismanagement. It has been believed that land use changes in Lake Urmia basin is one of the most important factors in shrinkage of Urmia Lake in recent decades. Transforming the traditional agricultural practices (i.e., wheat) to the more water consuming practices (i.e., apple orchards) is one of the most important reasons increased agricultural water consumption in the watershed. In this study we assessed the effect of the land use changes of watershed in hydrological runoff processing in the Nazloo chai watershed, one of the most important river basins of the Urmia Lake basin. Actually the rapid and at the same time unreasonable transformations of land use in farm lands of Urmia lake sub basins, extremely has been raised the amount of blue water (surface or groundwater) consumption in watershed which leads to dramatic decrement of watershed runoff amounts. One of the most unfavorable consequences of land use change was changing the blue and green (rainwater insofar as it does not become runoff) water usage patterns in watershed, in addition to water use increment. The soil and water assessment tool (SWAT), one of the most important and reliable models which was used to model the rainfall runoff, has been used in current study. The land use maps were extracted from Landsat images archives for the most severe turning points in respect of land use change in the recent 30 years. After calibrating the model, several land use patterns of historical data were used in the model to produce the runoff. The results showed the strong relation between land use change and runoff reduction in the Lake Urmia basin.

Juxta-articular Plate Fixation in Distal Radius Intra-articular Fractures with Accompanying Volar Free Fragments beyond the Watershed Line

PubMed Central

Lee, Jun-Ku; Lee, Soo-Hyun; Sim, Young-Suk; Kim, Tae-Ho; Baek, Eugene

2018-01-01

Background Although distal radius fractures (DRF) are common fractures, intra-articular comminuted DRF with volar free fragments are uncommon. There is considerable difficulty in the fixation of free fragments beyond the watershed line using the existing volar locking plate. We aimed to examine the efficacy and potential complications associated with the use of juxta-articular volar plates in intra-articular DRF accompanied by free fragments beyond the watershed line. Methods The patients were enrolled in a consecutive manner between 2007 and 2016. In cases of DRF with free fragments beyond the watershed line, we employed a 2.4-mm small fragment juxta-articular volar locking compression plate using a volar Henry approach. A total of 32 patients were included in this study. There were 15 males and 17 females with a mean age of 52.3 years (range, 33 to 69 years). The mean follow-up period was 14.5 months (range, 10 to 24 months). Preoperative radiographs and three-dimensional computed tomography images were used to analyze fracture patterns and assess the free fragments beyond the watershed line. The mean number of free fracture fragments beyond the watershed line was 2.33. Plain radiographs of immediate postoperative and last follow-up were used to confirm fracture union, incongruence, radial height, volar tilt, radial inclination, and arthritic changes. For functional assessment, we measured grip strength, range of motion (ROM), modified Mayo wrist score (MMWS) and determined Disabilities of Arm, Shoulder and Hand (DASH) scores at the last follow-up. Postoperative complications were monitored during the follow-up period. Results All patients obtained sound union without significant complications. At the last follow-up, 16 cases presented with an articular step-off of more than 1 mm (mean, 1.10 mm). The mean MMWS was 76.3 (range, 55 to 90), mean DASH score was 15.38 (range, 9 to 22), mean visual analogue scale score for pain was 1.2 and mean grip strength was 75.5% of the opposite side. The mean ROM was 74.3° for volar flexion and 71.5° for dorsiflexion. Conclusions In cases of intra-articular DRF with free fragments beyond the watershed line, a volar approach with use of a juxtaarticular plate provided favorable outcomes without significant complications. PMID:29854335

Statistical Techniques for Assessing water‐quality effects of BMPs

USGS Publications Warehouse

Walker, John F.

1994-01-01

Little has been published on the effectiveness of various management practices in small rural lakes and streams at the watershed scale. In this study, statistical techniques were used to test for changes in water‐quality data from watersheds where best management practices (BMPs) were implemented. Reductions in data variability due to climate and seasonality were accomplished through the use of regression methods. This study discusses the merits of using storm‐mass‐transport data as a means of improving the ability to detect BMP effects on stream‐water quality. Statistical techniques were applied to suspended‐sediment records from three rural watersheds in Illinois for the period 1981–84. None of the techniques identified changes in suspended sediment, primarily because of the small degree of BMP implementation and because of potential errors introduced through the estimation of storm‐mass transport. A Monte Carlo sensitivity analysis was used to determine the level of discrete change that could be detected for each watershed. In all cases, the use of regressions improved the ability to detect trends.Read More: http://ascelibrary.org/doi/abs/10.1061/(ASCE)0733-9437(1994)120:2(334)

Modeling flood reduction effects of low impact development at a watershed scale.

PubMed

Ahiablame, Laurent; Shakya, Ranish

2016-04-15

Low impact development (LID) is a land development approach that seeks to mimic a site's pre-development hydrology. This study is a case study that assessed flood reduction capabilities of large-scale adoption of LID practices in an urban watershed in central Illinois using the Personal Computer Storm Water Management Model (PCSWMM). Two flood metrics based on runoff discharge were developed to determine action flood (43 m(3)/s) and major flood (95 m(3)/s). Four land use scenarios for urban growth were evaluated to determine the impacts of urbanization on runoff and flooding. Flood attenuation effects of porous pavement, rain barrel, and rain garden at various application levels were also evaluated as retrofitting technologies in the study watershed over a period of 30 years. Simulation results indicated that increase in urban land use from 50 to 94% between 1992 and 2030 increased average annual runoff and flood events by more than 30%, suggesting that urbanization without sound management would increase flood risks. The various implementation levels of the three LID practices resulted in 3-47% runoff reduction in the study watershed. Flood flow events that include action floods and major floods were also reduced by 0-40%, indicating that LID practices can be used to mitigate flood risk in urban watersheds. The study provides an insight into flood management with LID practices in existing urban areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

Overcoming limited information through participatory watershed management: Case study in Amhara, Ethiopia

NASA Astrophysics Data System (ADS)

Liu, Benjamin M.; Abebe, Yitayew; McHugh, Oloro V.; Collick, Amy S.; Gebrekidan, Brhane; Steenhuis, Tammo S.

This study highlights two highly degraded watersheds in the semi-arid Amhara region of Ethiopia where integrated water resource management activities were carried out to decrease dependence on food aid through improved management of ‘green’ water. While top-down approaches require precise and centrally available knowledge to deal with the uncertainty in engineering design of watershed management projects, bottom-up approaches can succeed without such information by making extensive use of stakeholder knowledge. This approach works best in conjunction with the development of leadership confidence within local communities. These communities typically face a number of problems, most notably poverty, that prevent them from fully investing in the protection of their natural resources, so an integrated management system is needed to suitably address the interrelated problems. Many different implementing agencies were brought together in the two study watersheds to address water scarcity, crop production, and soil erosion, but the cornerstone was enabling local potential through the creation and strengthening of community watershed management organizations. Leadership training and the reinforcement of stakeholder feedback as a fundamental activity led to increased ownership and willingness to take on new responsibilities. A series of small short term successes ranging from micro-enterprise cooperatives to gully rehabilitation have resulted in the pilot communities becoming confident of their own capabilities and proud to share their successes and knowledge with other communities struggling with natural resource degradation.

Can isolated and riparian wetlands mitigate the impact of climate change on watershed hydrology? A case study approach.

PubMed

Fossey, M; Rousseau, A N

2016-12-15

The effects of wetlands on stream flows are well established, namely mitigating flow regimes through water storage and slow water release. However, their effectiveness in reducing flood peaks and sustaining low flows is mainly driven by climate conditions and wetland type with respect to their connectivity to the hydrographic network (i.e. isolated or riparian wetlands). While some studies have demonstrated these hydrological functions/services, few of them have focused on the benefits to the hydrological regimes and their evolution under climate change (CC) and, thus, some gaps persist. The objective of this study was to further advance our knowledge with that respect. The PHYSITEL/HYDROTEL modelling platform was used to assess current and future states of watershed hydrology of the Becancour and Yamaska watersheds, Quebec, Canada. Simulation results showed that CC will induce similar changes on mean seasonal flows, namely larger and earlier spring flows leading to decreases in summer and fall flows. These expected changes will have different effects on 20-year and 100-year peak flows with respect to the considered watershed. Nevertheless, conservation of current wetland states should: (i) for the Becancour watershed, mitigate the potential increase in 2-year, 20-year and 100-year peak flows; and (ii) for the Yamaska watershed, accentuate the potential decrease in the aforementioned indicators. However, any loss of existing wetlands would be detrimental for 7-day 2-year and 10-year as well as 30-day 5-year low flows. Copyright © 2016 Elsevier Ltd. All rights reserved.

a New Multi-Spectral Threshold Normalized Difference Water Index Mst-Ndwi Water Extraction Method - a Case Study in Yanhe Watershed

NASA Astrophysics Data System (ADS)

Zhou, Y.; Zhao, H.; Hao, H.; Wang, C.

2018-05-01

Accurate remote sensing water extraction is one of the primary tasks of watershed ecological environment study. Since the Yanhe water system has typical characteristics of a small water volume and narrow river channel, which leads to the difficulty for conventional water extraction methods such as Normalized Difference Water Index (NDWI). A new Multi-Spectral Threshold segmentation of the NDWI (MST-NDWI) water extraction method is proposed to achieve the accurate water extraction in Yanhe watershed. In the MST-NDWI method, the spectral characteristics of water bodies and typical backgrounds on the Landsat/TM images have been evaluated in Yanhe watershed. The multi-spectral thresholds (TM1, TM4, TM5) based on maximum-likelihood have been utilized before NDWI water extraction to realize segmentation for a division of built-up lands and small linear rivers. With the proposed method, a water map is extracted from the Landsat/TM images in 2010 in China. An accuracy assessment is conducted to compare the proposed method with the conventional water indexes such as NDWI, Modified NDWI (MNDWI), Enhanced Water Index (EWI), and Automated Water Extraction Index (AWEI). The result shows that the MST-NDWI method generates better water extraction accuracy in Yanhe watershed and can effectively diminish the confusing background objects compared to the conventional water indexes. The MST-NDWI method integrates NDWI and Multi-Spectral Threshold segmentation algorithms, with richer valuable information and remarkable results in accurate water extraction in Yanhe watershed.

Long-term watershed research and monitoring to understand ecosystem change in parks and equivalent reserves

USGS Publications Warehouse

Herrmann, R.

1997-01-01

Integrated watershed ecosystem studies in National Parks or equivalent reserves suggest that effects of external processes on 'protected' resources are subtle, chronic, and long-term. Ten years of data from National Park watersheds suggests that temperature and precipitation changes are linked to nitrogen levels in lakes and streams. We envision measurable biotic effects in these remote watersheds, if expected climate trends continue. The condition of natural resources within areas set aside for preservation are difficult to ascertain, but gaining this knowledge is the key to understanding ecosystem change and of processes operating among biotic and abiotic ecosystem components. There is increasing evidence that understanding the magnitude of variation within and between such processes can provide an early indication of environmental change and trends attributable to human-induced stress. The following four papers are case studies of how this concept has been implemented. These long-term studies have expanded our knowledge of ecosystem response to natural and human-induced stress. The existence of these sites with a commitment to gathering 'long-term' ecosystem-level data permits research activities aimed at testing more important hypotheses on ecosystem processes and structure.

Point-nonpoint effluent trading in watersheds: A review and critique

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

Jarvie, M.; Solomon, B.

1998-03-01

The 1990s have been characterized as the decade of market incentives in US environmental policy-making. Not only is their use expanding for air pollution control, but the US Environmental Protection Agency is now also encouraging the use of market instruments for control of effluents within watersheds. After reviewing general guidelines and principles for effluent trading, this study considers the special problems of point-nonpoint (p-n) sources, the most common focus of effluent trading to date. Four case studies of p-n trading are discussed, which illustrate the promise of the policy. Although only two of these four case study programs have involvedmore » actual effluent trades thus far, they all have resulted in more cost-effective reductions of water pollution. Overall use of effluent trading to date has been modest, and suggestions are made for improvement of this innovative policy.« less

Impacts of future climate change on river discharge based on hydrological inference: A case study of the Grand River Watershed in Ontario, Canada.

PubMed

Li, Zhong; Huang, Guohe; Wang, Xiuquan; Han, Jingcheng; Fan, Yurui

2016-04-01

Over the recent years, climate change impacts have been increasingly studied at the watershed scale. However, the impact assessment is strongly dependent upon the performance of the climatic and hydrological models. This study developed a two-step method to assess climate change impacts on water resources based on the Providing Regional Climates for Impacts Studies (PRECIS) modeling system and a Hydrological Inference Model (HIM). PRECIS runs provided future temperature and precipitation projections for the watershed under the Intergovernmental Panel on Climate Change SRES A2 and B2 emission scenarios. The HIM based on stepwise cluster analysis is developed to imitate the complex nonlinear relationships between climate input variables and targeted hydrological variables. Its robust mathematical structure and flexibility in predictor selection makes it a desirable tool for fully utilizing various climate modeling outputs. Although PRECIS and HIM cannot fully cover the uncertainties in hydro-climate modeling, they could provide efficient decision support for investigating the impacts of climate change on water resources. The proposed method is applied to the Grand River Watershed in Ontario, Canada. The model performance is demonstrated with comparison to observation data from the watershed during the period 1972-2006. Future river discharge intervals that accommodate uncertainties in hydro-climatic modeling are presented and future river discharge variations are analyzed. The results indicate that even though the total annual precipitation would not change significantly in the future, the inter-annual distribution is very likely to be altered. The water availability is expected to increase in Winter while it is very likely to decrease in Summer over the Grand River Watershed, and adaptation strategies would be necessary. Copyright © 2016 Elsevier B.V. All rights reserved.

BASINS User Information and Guidance

EPA Pesticide Factsheets

This page provides links to guidance on how to use BASINS, including the User’s Manual, tutorials and training, technical notes, case studies, and publications that highlight the use of BASINS in various watershed analyses.

[Evaluation on the eco-economic benefits of small watershed in Beijing mountainous area: a case of Yanqi River watershed].

PubMed

Xiao, Hui-Jie; Wei, Zi-Gang; Wang, Qing; Zhu, Xiao-Bo

2012-12-01

Based on the theory of harmonious development of ecological economy, a total of 13 evaluation indices were selected from the ecological, economic, and social sub-systems of Yanqi River watershed in Huairou District of Beijing. The selected evaluation indices were normalized by using trapezoid functions, and the weights of the evaluation indices were determined by analytic hierarchy process. Then, the eco-economic benefits of the watershed were evaluated with weighted composite index method. From 2004 to 2011, the ecological, economic, and social benefits of Yanqi River watershed all had somewhat increase, among which, ecological benefit increased most, with the value changed from 0.210 in 2004 to 0.255 in 2011 and an increment of 21.5%. The eco-economic benefits of the watershed increased from 0.734 in 2004 to 0.840 in 2011, with an increment of 14.2%. At present, the watershed reached the stage of advanced ecosystem, being in beneficial circulation and harmonious development of ecology, economy, and society.

Urban base flow with low impact development

USGS Publications Warehouse

Bhaskar, Aditi; Hogan, Dianna M.; Archfield, Stacey A.

2016-01-01

A novel form of urbanization, low impact development (LID), aims to engineer systems that replicate natural hydrologic functioning, in part by infiltrating stormwater close to the impervious surfaces that generate it. We sought to statistically evaluate changes in a base flow regime because of urbanization with LID, specifically changes in base flow magnitude, seasonality, and rate of change. We used a case study watershed in Clarksburg, Maryland, in which streamflow was monitored during whole-watershed urbanization from forest and agricultural to suburban residential development using LID. The 1.11-km2 watershed contains 73 infiltration-focused stormwater facilities, including bioretention facilities, dry wells, and dry swales. We examined annual and monthly flow during and after urbanization (2004–2014) and compared alterations to nearby forested and urban control watersheds. We show that total streamflow and base flow increased in the LID watershed during urbanization as compared with control watersheds. The LID watershed had more gradual storm recessions after urbanization and attenuated seasonality in base flow. These flow regime changes may be because of a reduction in evapotranspiration because of the overall decrease in vegetative cover with urbanization and the increase in point sources of recharge. Precipitation that may once have infiltrated soil, been stored in soil moisture to be eventually transpired in a forested landscape, may now be recharged and become base flow. The transfer of evapotranspiration to base flow is an unintended consequence to the water balance of LID.

Contingent Valuation of Residents' Attitudes and Willingness-to-Pay for Non-point Source Pollution Control: A Case Study in AL-Prespa, Southeastern Albania

NASA Astrophysics Data System (ADS)

Grazhdani, Dorina

2015-07-01

Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods—dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was €6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas.

Contingent Valuation of Residents' Attitudes and Willingness-to-Pay for Non-point Source Pollution Control: A Case Study in AL-Prespa, Southeastern Albania.

PubMed

Grazhdani, Dorina

2015-07-01

Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods--dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was 6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas.

A methodological framework to assess PMP and PMF in snow-dominated watersheds under changing climate conditions - A case study of three watersheds in Québec (Canada)

NASA Astrophysics Data System (ADS)

Rouhani, Hassan; Leconte, Robert

2018-06-01

Climate change will affect precipitation and flood regimes. It is anticipated that the Probable Maximum Precipitation (PMP) and Probable Maximum Flood (PMF) will be modified in a changing climate. This paper aims to quantify and analyze climate change influences on PMP and PMF in three watersheds with different climatic conditions across the province of Québec, Canada. Output data from the Canadian Regional Climate Model (CRCM) was used to estimate PMP and Probable Maximum Snow Accumulation (PMSA) in future climate projections, which was then used to force the SWAT hydrological model to estimate PMF. PMP and PMF values were estimated for two time horizons each spanning 30 years: 1961-1990 (recent past) and 2041-2070 (future). PMP and PMF were separately analyzed for two seasons: summer-fall and spring. Results show that PMF in the watershed located in southern Québec would remain unchanged in the future horizon, but the trend for the watersheds located in the northeastern and northern areas of the province is an increase of up to 11%.

Approach and case-study of green infrastructure screening analysis for urban stormwater control.

PubMed

Eaton, Timothy T

2018-03-01

Urban stormwater control is an urgent concern in megacities where increased impervious surface has disrupted natural hydrology. Water managers are increasingly turning to more environmentally friendly ways of capturing stormwater, called Green Infrastructure (GI), to mitigate combined sewer overflow (CSO) that degrades local water quality. A rapid screening approach is described to evaluate how GI strategies can reduce the amount of stormwater runoff in a low-density residential watershed in New York City. Among multiple possible tools, the L-THIA LID online software package, using the SCS-CN method, was selected to estimate relative runoff reductions expected with different strategies in areas of different land uses in the watershed. Results are sensitive to the relative areas of different land uses, and show that bioretention and raingardens provide the maximum reduction (∼12%) in this largely residential watershed. Although commercial, industrial and high-density residential areas in the watershed are minor, larger runoff reductions from disconnection strategies and porous pavement in parking lots are also possible. Total stormwater reductions from various combinations of these strategies can reach 35-55% for individual land uses, and between 23% and 42% for the entire watershed. Copyright © 2017. Published by Elsevier Ltd.

Identifying strategic sites for Green-Infrastructures (GI) to manage stormwater in a miscellaneous use urban African watershed

NASA Astrophysics Data System (ADS)

Selker, J. S.; Kahsai, S. K.

2017-12-01

Green Infrastructure (GI) or Low impact development (LID), is a land use planning and design approach with the objective of mitigating land development impacts to the environment, and is ever more looked to as a way to lessen runoff and pollutant loading to receiving water bodies. Broad-scale approaches for siting GI/LID have been developed for agricultural watersheds, but are rare for urban watersheds, largely due to greater land use complexity. And it is even more challenging when it comes to Urban Africa due to the combination of poor data quality, rapid and unplanned development, and civic institutions unable to reliably carry out regular maintenance. We present a spacio-temporal simulation-based approach to identify an optimal prioritization of sites for GI/LID based on DEM, land use and land cover. Optimization used is a multi-objective optimization tool along with an urban storm water management model (SWMM) to identify the most cost-effective combination of LID/GI. This was applied to an urban watershed in NW Kampala, Lubigi Catchment (notorious for being heavily flooded every year), with a miscellaneous use watershed in Uganda, as a case-study to demonstrate the approach.

Flood Simulation Using WMS Model in Small Watershed after Strong Earthquake -A Case Study of Longxihe Watershed, Sichuan province, China

NASA Astrophysics Data System (ADS)

Guo, B.

2017-12-01

Mountain watershed in Western China is prone to flash floods. The Wenchuan earthquake on May 12, 2008 led to the destruction of surface, and frequent landslides and debris flow, which further exacerbated the flash flood hazards. Two giant torrent and debris flows occurred due to heavy rainfall after the earthquake, one was on August 13 2010, and the other on August 18 2010. Flash floods reduction and risk assessment are the key issues in post-disaster reconstruction. Hydrological prediction models are important and cost-efficient mitigation tools being widely applied. In this paper, hydrological observations and simulation using remote sensing data and the WMS model are carried out in the typical flood-hit area, Longxihe watershed, Dujiangyan City, Sichuan Province, China. The hydrological response of rainfall runoff is discussed. The results show that: the WMS HEC-1 model can well simulate the runoff process of small watershed in mountainous area. This methodology can be used in other earthquake-affected areas for risk assessment and to predict the magnitude of flash floods. Key Words: Rainfall-runoff modeling. Remote Sensing. Earthquake. WMS.

Periconal arterial anastomotic circle and posterior lumbosacral watershed zone of the spinal cord.

PubMed

Gailloud, Philippe; Gregg, Lydia; Galan, Peter; Becker, Daniel; Pardo, Carlos

2015-11-01

The existence of spinal cord watershed territories was suggested in the 1950s. Segmental infarcts within the junctional territories of adjacent radiculomedullary contributors and isolated spinal gray matter ischemia constitute two well-recognized types of watershed injury. This report describes the existence of another watershed territory related to the particular configuration of the spinal vasculature in the region of the conus medullaris. The anatomical bases underlying the concept of a posterior lumbosacral watershed zone are demonstrated with angiographic images obtained in a 16-year-old child. The clinical importance of this watershed zone is illustrated with MRI and angiographic data of three patients with a conus medullaris infarction. In all three cases of spinal ischemia an intersegmental artery providing a significant radiculomedullary contribution for the lower cord was compromised by a compressive mechanism responsible for decreased spinal cord perfusion (diaphragmatic crus syndrome in two cases, disk herniation in one). The ischemic injury, located at the junction of the anterior and posterior spinal artery territories along the dorsal aspect of the conus medullaris, was consistent with a watershed mechanism. This zone is at risk because of the caudocranial direction of flow within the most caudal segment of the posterior spinal arterial network which, from a functional standpoint, depends on the anterior spinal artery. The posterior thoracolumbar watershed zone of the spinal cord represents an area at increased risk of ischemic injury, particularly in the context of partial flow impairment related to arterial compression mechanisms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Scale effects on information theory-based measures applied to streamflow patterns in two rural watersheds

NASA Astrophysics Data System (ADS)

Pan, Feng; Pachepsky, Yakov A.; Guber, Andrey K.; McPherson, Brian J.; Hill, Robert L.

2012-01-01

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 nested sub-watersheds and more than 30 years of continuous data records of precipitation and streamflow. Information content measures (metric entropy and mean information gain) and complexity measures (effective measure complexity and fluctuation complexity) were computed based on the binary encoding of 5-year streamflow and precipitation time series data. We quantified patterns of streamflow using probabilities of joint or sequential appearances of the binary symbol sequences. Results of our analysis illustrate that information content measures of streamflow time series are much smaller than those for precipitation data, and the streamflow data also exhibit higher complexity, suggesting that the watersheds effectively act as filters of the precipitation information that leads to the observed additional complexity in streamflow measures. Correlation coefficients between the information-theory-based measures and time intervals are close to 0.9, demonstrating the significance of temporal scale effects on streamflow patterns. Moderate spatial scale effects on streamflow patterns are observed with absolute values of correlation coefficients between the measures and sub-watershed area varying from 0.2 to 0.6 in the two watersheds. We conclude that temporal effects must be evaluated and accounted for when the information theory-based methods are used for performance evaluation and comparison of hydrological models.

Soil erosion modeled with USLE, GIS, and remote sensing: a case study of Ikkour watershed in Middle Atlas (Morocco)

NASA Astrophysics Data System (ADS)

El Jazouli, Aafaf; Barakat, Ahmed; Ghafiri, Abdessamad; El Moutaki, Saida; Ettaqy, Abderrahim; Khellouk, Rida

2017-12-01

The Ikkour watershed located in the Middle Atlas Mountain (Morocco) has been a subject of serious soil erosion problems. This study aimed to assess the soil erosion susceptibility in this mountainous watershed using Universal Soil Loss Equation (USLE) and spectral indices integrated with Geographic Information System (GIS) environment. The USLE model required the integration of thematic factors' maps which are rainfall aggressiveness, length and steepness of the slope, vegetation cover, soil erodibility, and erosion control practices. These factors were calculated using remote sensing data and GIS. The USLE-based assessment showed that the estimated total annual potential soil loss was about 70.66 ton ha-1 year-1. This soil loss is favored by the steep slopes and degraded vegetation cover. The spectral index method, offering a qualitative evaluation of water erosion, showed different degrees of soil degradation in the study watershed according to FI, BI, CI, and NDVI. The results of this study displayed an agreement between the USLE model and spectral index approach, and indicated that the predicted soil erosion rate can be due to the most rugged land topography and an increase in agricultural areas. Indeed, these results can further assist the decision makers in implementation of suitable conservation program to reduce soil erosion.

Spatial model of land use change related to sediment yield (case study: Cipeles and Cilutung watershed, West Java)

NASA Astrophysics Data System (ADS)

Wulandari, D. W.; Kusratmoko, E.; Indra, T. L.

2018-05-01

Land use changes (LUC) as a result of increasing human need for space are likely to destroy the hydrological function of the watershed, increase land degradation, stimulate erosion and drive the process of sedimentation. This study aimed to predict LUC during the period 1990 to 2030 in relation to sediment yield in Cilutung and Cipeles Watershed, West Java. LUC were simulated following the model of Cellular Automata-Marcov Chain, whereas land use composition in 2030 was predicted using Land Change Modeler on Idrisi Selva Software. Elevation, slope, distance from road, distance from river, and distance from settlement were selected as driving factors for LUC in this study. Erosion and sediment yield were predicted using WATEM/SEDEM model based on land use, rainfall, soil texture and topography. The results showed that the areas of forest and shrub have slightly declined up to 5% during the period 1990 to 2016, generally being converted into rice fields, settlements, non-irrigated fields and plantations. In addition, rice fields, settlements, and plantations were expected to substantially increase up to 50% in 2030. Furthermore, the study also revealed that erosion and sediment yield tend to increase every year. This is likely associated with LUC occurring in Cipeles and Cilutung Watershed.

Using stable isotopes to examine watershed connectivity to ...

EPA Pesticide Factsheets

Water bodies within the USA are protected by the US Clean Water Act when they have a significant nexus to downstream navigable waters. As a research scientist with the US Environmental Protection Agency, I have used water stable isotopes to examine hydrologic connectivity dynamics. I will share two case studies. In the first case, we used the isotopic evaporation signal in water to examine wetland-stream hydrologic connectivity within the Pipestem Creek watershed, North Dakota, a watershed dominated by prairie-pothole wetlands. Prairie-Pothole wetlands are a special case of wetlands whose protection needs to be determined under the Clean Water Rule. Pipestem Creek exhibited an evaporated-water signal that had approximately half the isotopic-enrichment signal found in most evaporatively enriched prairie-pothole wetlands. Groundwater measured at the water table adjacent to Pipestem Creek had isotopic values that indicated recharge from winter precipitation and had no significant evaporative enrichment. Using isotopic theory and discharge data, we estimated the area of surface water necessary to generate the evaporation signal found within Pipestem Creek over two years. Our results indicated that prairie-pothole wetlands were important sources of stream flow in Pipestem Creek throughout the summer, as well as during snowmelt. They also demonstrated that at the lowest flows, the stream itself became disconnected from headwater stream reaches. In the second ca

3D marker-controlled watershed for kidney segmentation in clinical CT exams.

PubMed

Wieclawek, Wojciech

2018-02-27

Image segmentation is an essential and non trivial task in computer vision and medical image analysis. Computed tomography (CT) is one of the most accessible medical examination techniques to visualize the interior of a patient's body. Among different computer-aided diagnostic systems, the applications dedicated to kidney segmentation represent a relatively small group. In addition, literature solutions are verified on relatively small databases. The goal of this research is to develop a novel algorithm for fully automated kidney segmentation. This approach is designed for large database analysis including both physiological and pathological cases. This study presents a 3D marker-controlled watershed transform developed and employed for fully automated CT kidney segmentation. The original and the most complex step in the current proposition is an automatic generation of 3D marker images. The final kidney segmentation step is an analysis of the labelled image obtained from marker-controlled watershed transform. It consists of morphological operations and shape analysis. The implementation is conducted in a MATLAB environment, Version 2017a, using i.a. Image Processing Toolbox. 170 clinical CT abdominal studies have been subjected to the analysis. The dataset includes normal as well as various pathological cases (agenesis, renal cysts, tumors, renal cell carcinoma, kidney cirrhosis, partial or radical nephrectomy, hematoma and nephrolithiasis). Manual and semi-automated delineations have been used as a gold standard. Wieclawek Among 67 delineated medical cases, 62 cases are 'Very good', whereas only 5 are 'Good' according to Cohen's Kappa interpretation. The segmentation results show that mean values of Sensitivity, Specificity, Dice, Jaccard, Cohen's Kappa and Accuracy are 90.29, 99.96, 91.68, 85.04, 91.62 and 99.89% respectively. All 170 medical cases (with and without outlines) have been classified by three independent medical experts as 'Very good' in 143-148 cases, as 'Good' in 15-21 cases and as 'Moderate' in 6-8 cases. An automatic kidney segmentation approach for CT studies to compete with commonly known solutions was developed. The algorithm gives promising results, that were confirmed during validation procedure done on a relatively large database, including 170 CTs with both physiological and pathological cases.

Remote estimation of surface moisture over a watershed. M.S. Thesis; [Goodwater Creek Watershed, Missouri

NASA Technical Reports Server (NTRS)

Kocin, P. J. (Principal Investigator)

1979-01-01

The author has identified the following significant results. Contoured analyses of moisture availability, moisture flux, sensible heat flux, thermal inertia, and day and nighttime temperatures over a Missouri watershed for a date in June and in September show that forests and creeks exhibit the highest values of moisture availability, whereas farmlands and villages are relatively dry. The distribution of moisture availability over agricultural districts differs significantly between the two cases. This difference is attributed to a change in the surface's vegetative canopy between June and September, with higher moisture availabilities found in the latter case. Horizontal variations of moisture, however, do indicate some relationship between moisture availability and both local rainfall accumulations and the nature of the terrain.

Suspended sediment source areas and future climate impact on soil erosion and sediment yield in a New York City water supply watershed, USA

NASA Astrophysics Data System (ADS)

Mukundan, Rajith; Pradhanang, Soni M.; Schneiderman, Elliot M.; Pierson, Donald C.; Anandhi, Aavudai; Zion, Mark S.; Matonse, Adão H.; Lounsbury, David G.; Steenhuis, Tammo S.

2013-02-01

High suspended sediment loads and the resulting turbidity can impact the use of surface waters for water supply and other designated uses. Changes in fluvial sediment loads influence material fluxes, aquatic geochemistry, water quality, channel morphology, and aquatic habitats. Therefore, quantifying spatial and temporal patterns in sediment loads is important both for understanding and predicting soil erosion and sediment transport processes as well as watershed-scale management of sediment and associated pollutants. A case study from the 891 km2 Cannonsville watershed, one of the major watersheds in the New York City water supply system is presented. The objective of this study was to apply Soil and Water Assessment Tool-Water Balance (SWAT-WB), a physically based semi-distributed model to identify suspended sediment generating source areas under current conditions and to simulate potential climate change impacts on soil erosion and suspended sediment yield in the study watershed for a set of future climate scenarios representative of the period 2081-2100. Future scenarios developed using nine global climate model (GCM) simulations indicate a sharp increase in the annual rates of soil erosion although a similar result in sediment yield at the watershed outlet was not evident. Future climate related changes in soil erosion and sediment yield appeared more significant in the winter due to a shift in the timing of snowmelt and also due to a decrease in the proportion of precipitation received as snow. Although an increase in future summer precipitation was predicted, soil erosion and sediment yield appeared to decrease owing to an increase in soil moisture deficit and a decrease in water yield due to increased evapotranspiration.

Effects of atmospheric reactive phosphorus deposition on phosphorus transport in a subtropical watershed: A Chinese case study.

PubMed

Gao, Yang; Hao, Zhuo; Yang, Tiantian; He, Nianpeng; Wen, Xuefa; Yu, Guirui

2017-07-01

Atmospheric phosphorus (P) deposition is not only an important external macronutrient source for aquatic ecosystems but also a major cause of high export coefficient (EC) values. However, there are limited numbers of studies in the literature that focus on estimating the deposition flux of reactive P (P r ). The aim of this study is to estimate the P r deposition on the Xiangxi River watershed, and therefore, provide a comprehensive understanding about the P r deposition on subtropical watersheds in China. Results have shown that maximal P r deposition fluxes reached 12 kg km -2 in our selected subtropical watershed. Furthermore, we found out the particulate phosphorus (PP) were dominating the total P r deposition in the Xiangxi River watershed. According to our experiments, certain forms of P r deposition were associated with high correlation coefficients with respect to the variation of rainfall intensity. Results also demonstrated that the dissolved organic phosphorus (DOP) and soluble reactive phosphorus (SRP) via wet deposition had large influences on the DOP and SRP concentrations in runoff, while the PO 4 -P and PP via wet deposition only affected PO 4 -P and PP loads through runoff discharge. Our experiments also shown that most parts of the P r in runoff water was derived from rainfall and its magnitudes varied with land types. Results suggested that during the dry season, the P r wet deposition not only was an important source for the P r transport driven by runoff, but also was one of the most important influencing factors that dominated the P r transport in subtropical watersheds. Copyright © 2017 Elsevier Ltd. All rights reserved.

TRIPLE-VALUE SIMULATION MODELING CASES TACKLE NUTRIENT AND WATERSHED MANAGEMENT FROM A SOCIAL-ECOLOGICAL SYSTEMS PERSPECTIVE

EPA Science Inventory

Decision makers often need assistance in understanding dynamic interactions and linkages among economic, environmental and social systems in coastal watersheds. They also need scientific input to better evaluate potential costs and benefits of alternative policy interventions. EP...

Research article: Watershed management councils and scientific models: Using diffusion literature to explain adoption

USGS Publications Warehouse

King, M.D.; Burkardt, N.; Clark, B.T.

2006-01-01

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.

pyLIDEM: A Python-Based Tool to Delineate Coastal Watersheds Using LIDAR Data

NASA Astrophysics Data System (ADS)

O'Banion, R.; Alameddine, I.; Gronewold, A.; Reckhow, K.

2008-12-01

Accurately identifying the boundary of a watershed is one of the most fundamental and important steps in any hydrological assessment. Representative applications include defining a study area, predicting overland flow, estimating groundwater infiltration, modeling pollutant accumulation and wash-off rates, and evaluating effectiveness of pollutant mitigation measures. The United States Environmental Protection Agency (USEPA) Total Maximum Daily Load (TMDL) program, the most comprehensive water quality management program in the United States (US), is just one example of an application in which accurate and efficient watershed delineation tools play a critical role. For example, many impaired water bodies currently being addressed through the TMDL program drain small coastal watersheds with relatively flat terrain, making watershed delineation particularly challenging. Most of these TMDL studies use 30-meter digital elevation models (DEMs) that rarely capture all of the small elevation changes in coastal watersheds, leading to errors not only in watershed boundary delineation, but in subsequent model predictions (such as watershed runoff flow and pollutant deposition rate predictions) for which watershed attributes are key inputs. Manually delineating these low-relief coastal watersheds through the use of expert knowledge of local water flow patterns, often produces relatively accurate (and often more accurate) watershed boundaries as compared to the boundaries generated by the 30-meter DEMs. Yet, manual delineation is a costly and time consuming procedure that is often not opted for. There is a growing need, therefore, particularly to address the ongoing needs of the TMDL program (and similar environmental management programs), for software tools which can utilize high resolution topography data to more accurately delineate coastal watersheds. Here, we address this need by developing pyLIDEM (python LIdar DEM), a python-based tool which processes bare earth high-resolution Light Detection and Ranging (LIDAR) data, generates fine scale DEMs, and delineates watershed boundaries for a given pour point. Because LIDAR data are typically distributed in large sets of predefined tiles, our tool is capable of combining only the minimum number of bare earth LIDAR tiles required to delineate a watershed of interest. Our tool then processes the LIDAR data into Triangulated Irregular Networks, generates DEMs at user- specified cell sizes, and creates the required files needed to delineate watersheds within ArcGIS. To make pyLIDEM more accessible to the modeling community, we have bundled it within an ArcGIS toolbox, which also allows users to run it directly from an ArcGIS platform. We assess pyLIDEM functionality and accuracy by delineating several impaired small coastal watersheds in the Newport River Estuary in Eastern North Carolina using LIDAR data collected for the North Carolina Flood Mapping Program. We then compare the pyLIDAR-based watershed boundaries with those generated manually and with those generated using the 30-meter DEMs, and find that the pyLIDAR-based boundaries are more accurate than the 30-meter DEMs, and provide a significant time savings compared to manual delineation, particularly in cases where multiple watersheds need to be delineated for a single project.

Effects of mountain resort development - a case study in Vermont USA

NASA Astrophysics Data System (ADS)

Shanley, J.; Wemple, B.

2012-04-01

The mountainous landscape of northern New England, USA, faces intense development pressure from recreational and tourism use. In 2000 we began a paired-watershed study in northern Vermont to examine the effects of alpine resort development on stream flow and water quality. To our knowledge this is the only gaged watershed study at a mountain resort. The adjacent paired watersheds have similar topography, relief, geology and forest type, and differ primarily in land use. Ranch Brook watershed (9.6 km2) is the undeveloped, nearly 100% forested control basin. West Branch watershed (11.7 km2) is the developed basin, encompassing a pre-existing alpine ski resort and state highway, with approximately 17% of the basin occupied by ski trails and impervious surfaces. Measurements during 2000-2003 showed suspended sediment yield was >2.5 times greater and concentrations of nitrate and chloride were significantly elevated at West Branch. From 2004 through 2007 the resort expanded with more ski trails, roads, parking areas, and vacation home development and now has 24% cleared land, with storm sewers draining lower developed areas of the alpine watershed. For the 11-year period of study, water yield in the developed basin exceeded that in the control by an average of nearly 21%. The higher runoff at West Branch occurred primarily as result of higher sustained base flow, driven by a more prolonged snowmelt period, and greater runoff during small events. The annual flow differential had a strong positive correlation to maximum snow water equivalent, suggesting that differences in snow accumulation may explain the flow differential. We are investigating whether these differences are a direct consequence of management activities and resulting vegetation shifts and land clearing on snow capture. Several of the highest peak flows in both watersheds have occurred in the last 2 years of the 11-yr study. Our analysis is aimed at determining whether absolute peak flows have increased disproportionately at West Branch relative to the overall flow differential. As actual pre- and post-expansion flows differ markedly from design projections, our study also bears out the need for science-based management decisions.

Linking economic water use, freshwater ecosystem impacts, and virtual water trade in a Great Lakes watershed

NASA Astrophysics Data System (ADS)

Mubako, S. T.; Ruddell, B. L.; Mayer, A. S.

2013-12-01

The impact of human water uses and economic pressures on freshwater ecosystems is of growing interest for water resource management worldwide. This case study for a water-rich watershed in the Great Lakes region links the economic pressures on water resources as revealed by virtual water trade balances to the nature of the economic water use and the associated impacts on the freshwater ecosystem. A water accounting framework that combines water consumption data and economic data from input output tables is applied to quantify localized virtual water imports and exports in the Kalamazoo watershed which comprises ten counties. Water using economic activities at the county level are conformed to watershed boundaries through land use-water use relationships. The counties are part of a region implementing the Michigan Water Withdrawal Assessment Process, including new regulatory approaches for adaptive water resources management under a riparian water rights framework. The results show that at local level, there exists considerable water use intensity and virtual water trade balance disparity among the counties and between water use sectors in this watershed. The watershed is a net virtual water importer, with some counties outsourcing nearly half of their water resource impacts, and some outsourcing nearly all water resource impacts. The largest virtual water imports are associated with agriculture, thermoelectric power generation and industry, while the bulk of the exports are associated with thermoelectric power generation and commercial activities. The methodology is applicable to various spatial levels ranging from the micro sub-watershed level to the macro Great Lakes watershed region, subject to the availability of reliable water use and economic data.

Phosphorus losses from an irrigated watershed in the northwestern United States: case study of the upper snake rock watershed.

PubMed

Bjorneberg, David L; Leytem, April B; Ippolito, James A; Koehn, Anita C

2015-03-01

Watersheds using surface water for irrigation often return a portion of the water to a water body. This irrigation return flow often includes sediment and nutrients that reduce the quality of the receiving water body. Research in the 82,000-ha Upper Snake Rock (USR) watershed from 2005 to 2008 showed that, on average, water diverted from the Snake River annually supplied 547 kg ha of total suspended solids (TSS), 1.1 kg ha of total P (TP), and 0.50 kg ha of dissolved P (DP) to the irrigation tract. Irrigation return flow from the USR watershed contributed 414 kg ha of TSS, 0.71 kg ha of TP, and 0.32 kg ha of DP back to the Snake River. Significantly more TP flowed into the watershed than returned to the Snake River, whereas there was no significant difference between inflow and return flow loads for TSS and DP. Average TSS and TP concentrations in return flow were 71 and 0.12 mg L, respectively, which exceeded the TMDL limits of 52 mg L TSS and 0.075 mg L TP set for this section of the Snake River. Monitoring inflow and outflow for five water quality ponds constructed to reduce sediment and P losses from the watershed showed that TSS concentrations were reduced 36 to 75%, but DP concentrations were reduced only 7 to 16%. This research showed that continued implementation of conservation practices should result in irrigation return flow from the USR watershed meeting the total maximum daily load limits for the Snake River. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Characterizing and modelling river channel migration rates at a regional scale: Case study of south-east France.

PubMed

Alber, Adrien; Piégay, Hervé

2017-11-01

An increased awareness by river managers of the importance of river channel migration to sediment dynamics, habitat complexity and other ecosystem functions has led to an advance in the science and practice of identifying, protecting or restoring specific erodible corridors across which rivers are free to migrate. One current challenge is the application of these watershed-specific goals at the regional planning scales (e.g., the European Water Framework Directive). This study provides a GIS-based spatial analysis of the channel migration rates at the regional-scale. As a case study, 99 reaches were sampled in the French part of the Rhône Basin and nearby tributaries of the Mediterranean Sea (111,300 km 2 ). We explored the spatial correlation between the channel migration rate and a set of simple variables (e.g., watershed area, channel slope, stream power, active channel width). We found that the spatial variability of the channel migration rates was primary explained by the gross stream power (R 2  = 0.48) and more surprisingly by the active channel width scaled by the watershed area. The relationship between the absolute migration rate and the gross stream power is generally consistent with the published empirical models for freely meandering rivers, whereas it is less significant for the multi-thread reaches. The discussion focused on methodological constraints for a regional-scale modelling of the migration rates, and the interpretation of the empirical models. We hypothesize that the active channel width scaled by the watershed area is a surrogate for the sediment supply which may be a more critical factor than the bank resistance for explaining the regional-scale variability of the migration rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Addressing trend-related changes within cumulative effects studies in water resources planning

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

Canter, L.W., E-mail: envimptr@aol.com; Chawla, M.K.; Swor, C.T.

2014-01-15

Summarized herein are 28 case studies wherein trend-related causative physical, social, or institutional changes were connected to consequential changes in runoff, water quality, and riparian and aquatic ecological features. The reviewed cases were systematically evaluated relative to their identified environmental effects; usage of analytical frameworks, and appropriate models, methods, and technologies; and the attention given to mitigation and/or management of the resultant causative and consequential changes. These changes also represent important considerations in project design and operation, and in cumulative effects studies associated therewith. The cases were grouped into five categories: institutional changes associated with legislation and policies (seven cases);more » physical changes from land use changes in urbanizing watersheds (eight cases); physical changes from land use changes and development projects in watersheds (four cases); physical, institutional, and social changes from land use and related policy changes in river basins (three cases); and multiple changes within a comprehensive study of land use and policy changes in the Willamette River Basin in Oregon (six cases). A tabulation of 110 models, methods and technologies used in the studies is also presented. General observations from this review were that the features were unique for each case; the consequential changes were logically based on the causative changes; the analytical frameworks provided relevant structures for the studies, and the identified methods and technologies were pertinent for addressing both the causative and consequential changes. One key lesson was that the cases provide useful, “real-world” illustrations of the importance of addressing trend-related changes in cumulative effects studies within water resources planning. Accordingly, they could be used as an “initial tool kit” for addressing trend-related changes.« less

Analysis of the runoff generation mechanism for the investigation of the SCS-CN method applicability to a partial area experimental watershed

NASA Astrophysics Data System (ADS)

Soulis, K. X.; Valiantzas, J. D.; Dercas, N.; Londra, P. A.

2009-01-01

The Soil Conservation Service Curve Number (SCS-CN) method is widely used for predicting direct runoff volume for a given rainfall event. The applicability of the SCS-CN method and the runoff generation mechanism were thoroughly analysed in a Mediterranean experimental watershed in Greece. The region is characterized by a Mediterranean semi-arid climate. A detailed land cover and soil survey using remote sensing and GIS techniques, showed that the watershed is dominated by coarse soils with high hydraulic conductivities, whereas a smaller part is covered with medium textured soils and impervious surfaces. The analysis indicated that the SCS-CN method fails to predict runoff for the storm events studied, and that there is a strong correlation between the CN values obtained from measured runoff and the rainfall depth. The hypothesis that this correlation could be attributed to the existence of an impermeable part in a very permeable watershed was examined in depth, by developing a numerical simulation water flow model for predicting surface runoff generated from each of the three soil types of the watershed. Numerical runs were performed using the HYDRUS-1D code. The results support the validity of this hypothesis for most of the events examined where the linear runoff formula provides better results than the SCS-CN method. The runoff coefficient of this formula can be taken equal to the percentage of the impervious area. However, the linear formula should be applied with caution in case of extreme events with very high rainfall intensities. In this case, the medium textured soils may significantly contribute to the total runoff and the linear formula may significantly underestimate the runoff produced.

Investigation of the direct runoff generation mechanism for the analysis of the SCS-CN method applicability to a partial area experimental watershed

NASA Astrophysics Data System (ADS)

Soulis, K. X.; Valiantzas, J. D.; Dercas, N.; Londra, P. A.

2009-05-01

The Soil Conservation Service Curve Number (SCS-CN) method is widely used for predicting direct runoff volume for a given rainfall event. The applicability of the SCS-CN method and the direct runoff generation mechanism were thoroughly analysed in a Mediterranean experimental watershed in Greece. The region is characterized by a Mediterranean semi-arid climate. A detailed land cover and soil survey using remote sensing and GIS techniques, showed that the watershed is dominated by coarse soils with high hydraulic conductivities, whereas a smaller part is covered with medium textured soils and impervious surfaces. The analysis indicated that the SCS-CN method fails to predict runoff for the storm events studied, and that there is a strong correlation between the CN values obtained from measured runoff and the rainfall depth. The hypothesis that this correlation could be attributed to the existence of an impermeable part in a very permeable watershed was examined in depth, by developing a numerical simulation water flow model for predicting surface runoff generated from each of the three soil types of the watershed. Numerical runs were performed using the HYDRUS-1D code. The results support the validity of this hypothesis for most of the events examined where the linear runoff formula provides better results than the SCS-CN method. The runoff coefficient of this formula can be taken equal to the percentage of the impervious area. However, the linear formula should be applied with caution in case of extreme events with very high rainfall intensities. In this case, the medium textured soils may significantly contribute to the total runoff and the linear formula may significantly underestimate the runoff produced.

Watershed Complexity Impacts on Rainfall-Runoff Modeling

NASA Astrophysics Data System (ADS)

Goodrich, D. C.; Grayson, R.; Willgoose, G.; Palacios-Velez, O.; Bloeschl, G.

2002-12-01

Application of distributed hydrologic watershed models fundamentally requires watershed partitioning or discretization. In addition to partitioning the watershed into modeling elements, these elements typically represent a further abstraction of the actual watershed surface and its relevant hydrologic properties. A critical issue that must be addressed by any user of these models prior to their application is definition of an acceptable level of watershed discretization or geometric model complexity. A quantitative methodology to define a level of geometric model complexity commensurate with a specified level of model performance is developed for watershed rainfall-runoff modeling. In the case where watershed contributing areas are represented by overland flow planes, equilibrium discharge storage was used to define the transition from overland to channel dominated flow response. The methodology is tested on four subcatchments which cover a range of watershed scales of over three orders of magnitude in the USDA-ARS Walnut Gulch Experimental Watershed in Southeastern Arizona. It was found that distortion of the hydraulic roughness can compensate for a lower level of discretization (fewer channels) to a point. Beyond this point, hydraulic roughness distortion cannot compensate for topographic distortion of representing the watershed by fewer elements (e.g. less complex channel network). Similarly, differences in representation of topography by different model or digital elevation model (DEM) types (e.g. Triangular Irregular Elements - TINs; contour lines; and regular grid DEMs) also result in difference in runoff routing responses that can be largely compensated for by a distortion in hydraulic roughness.

Use of Sediment Budgets for Watershed Erosion Control Planning: A Case Study From Northern California

NASA Astrophysics Data System (ADS)

O'Connor, M.; McDavitt, W.

2002-05-01

Erosion, sedimentation and peak flow increases caused by forest management for commercial timber production may negatively affect aquatic habitat of endangered anadromous fish such as coho salmon ({\\ it O. kisutch}). This paper summarizes a portion of a Watershed Analysis study performed for Pacific Lumber Company, Scotia, CA, focusing on erosion and sedimentation processes and rates and downstream sediment routing and water quality in the Freshwater Creek watershed in northwest California. Hillslope, road and bank erosion, channel sedimentation and sediment rates were quantified using field surveys, aerial photo interpretation, and empirical modeling approaches for different elements of the study. Sediment transport rates for bedload were modeled, and sediment transport rates for suspended sediment were estimated based on size distribution of sediment inputs in relation to sizes transported in suspension. The resulting sediment budget was validated through comparison using recent short-term, high-quality estimates of suspended sediment yield collected by a community watershed group at a downstream monitoring site with technical assistance from the US Forest Service. Another check on the sediment budget was provided by bedload yield data from an adjacent watershed, Jacoby Creek. The sediment budget techniques and bedload routing models used for this study provide sediment yield estimates that are in good agreement with available data. These results suggest that sediment budget techniques that require moderate levels of fieldwork can be used to provide relatively accurate technical assessments for use in the TMDL process. The sediment budget also identifies the most significant sediment sources and suggests a framework within which effective erosion control strategies can be developed.

Quantifying the effects of overgrazing on mountainous watershed vegetation dynamics under a changing climate.

PubMed

Hao, Lu; Pan, Cen; Fang, Di; Zhang, Xiaoyu; Zhou, Decheng; Liu, Peilong; Liu, Yongqiang; Sun, Ge

2018-10-15

Grazing is a major ecosystem disturbance in arid regions that are increasingly threatened by climate change. Understanding the long-term impacts of grazing on rangeland vegetation dynamics in a complex terrain in mountainous regions is important for quantifying dry land ecosystem services for integrated watershed management and climate change adaptation. However, data on the detailed long-term spatial distribution of grazing activities are rare, which prevents trend detection and environmental impact assessments of grazing. This study quantified the impacts of grazing on vegetation dynamics for the period of 1983-2010 in the Upper Heihe River basin, a complex multiple-use watershed in northwestern China. We also examined the relative contributions of grazing and climate to vegetation change using a dynamic grazing pressure method. Spatial grazing patterns and temporal dynamics were mapped at a 1 km × 1 km pixel scale using satellite-derived leaf area index (LAI) data. We found that overgrazing was a dominant driver for LAI reduction in alpine grasslands and shrubs, especially for the periods of 1985-1991 and 1997-2004. Although the recent decade-long active grazing management contributed to the improvement of LAI and partially offset the negative effects of increased livestock, overgrazing has posed significant challenges to shrub-grassland ecosystem recovery in the eastern part of the study basin. We conclude that the positive effects of a warming and wetting climate on vegetation could be underestimated if the negative long-term grazing effects are not considered. Findings from the present case study show that assessing long-term climate change impacts on watersheds must include the influences of human activities. Our study provides important guidance for ecological restoration efforts in locating vulnerable areas and designing effective management practices in the study watershed. Such information is essential for natural resource management that aims at meeting multiple demands of watershed ecosystem services in arid and semiarid rangelands. Copyright © 2018 Elsevier B.V. All rights reserved.

Remote sensing requirements as suggested by watershed model sensitivity analyses

NASA Technical Reports Server (NTRS)

Salomonson, V. V.; Rango, A.; Ormsby, J. P.; Ambaruch, R.

1975-01-01

A continuous simulation watershed model has been used to perform sensitivity analyses that provide guidance in defining remote sensing requirements for the monitoring of watershed features and processes. The results show that out of 26 input parameters having meaningful effects on simulated runoff, 6 appear to be obtainable with existing remote sensing techniques. Of these six parameters, 3 require the measurement of the areal extent of surface features (impervious areas, water bodies, and the extent of forested area), two require the descrimination of land use that can be related to overland flow roughness coefficient or the density of vegetation so as to estimate the magnitude of precipitation interception, and one parameter requires the measurement of distance to get the length over which overland flow typically occurs. Observational goals are also suggested for monitoring such fundamental watershed processes as precipitation, soil moisture, and evapotranspiration. A case study on the Patuxent River in Maryland shows that runoff simulation is improved if recent satellite land use observations are used as model inputs as opposed to less timely topographic map information.

An adaptive watershed management assessment based on watershed investigation data.

PubMed

Kang, Min Goo; Park, Seung Woo

2015-05-01

The aim of this study was to assess the states of watersheds in South Korea and to formulate new measures to improve identified inadequacies. The study focused on the watersheds of the Han River basin and adopted an adaptive watershed management framework. Using data collected during watershed investigation projects, we analyzed the management context of the study basin and identified weaknesses in water use management, flood management, and environmental and ecosystems management in the watersheds. In addition, we conducted an interview survey to obtain experts' opinions on the possible management of watersheds in the future. The results of the assessment show that effective management of the Han River basin requires adaptive watershed management, which includes stakeholders' participation and social learning. Urbanization was the key variable in watershed management of the study basin. The results provide strong guidance for future watershed management and suggest that nonstructural measures are preferred to improve the states of the watersheds and that consistent implementation of the measures can lead to successful watershed management. The results also reveal that governance is essential for adaptive watershed management in the study basin. A special ordinance is necessary to establish governance and aid social learning. Based on the findings, a management process is proposed to support new watershed management practices. The results will be of use to policy makers and practitioners who can implement the measures recommended here in the early stages of adaptive watershed management in the Han River basin. The measures can also be applied to other river basins.

Spreadsheet WATERSHED modeling for nonpoint-source pollution management in a Wisconsin basin

USGS Publications Warehouse

Walker, J.F.; Pickard, S.A.; Sonzogni, W.C.

1989-01-01

Although several sophisticated nonpoint pollution models exist, few are available that are easy to use, cover a variety of conditions, and integrate a wide range of information to allow managers and planners to assess different control strategies. Here, a straightforward pollutant input accounting approach is presented in the form of an existing model (WATERSHED) that has been adapted to run on modern electronic spreadsheets. As an application, WATERSHED is used to assess options to improve the quality of highly eutrophic Delavan Lake in Wisconsin. WATERSHED is flexible in that several techniques, such as the Universal Soil Loss Equation or unit-area loadings, can be used to estimate nonpoint-source inputs. Once the model parameters are determined (and calibrated, if possible), the spreadsheet features can be used to conduct a sensitivity analysis of management options. In the case of Delavan Lake, it was concluded that, although some nonpoint controls were cost-effective, the overall reduction in phosphorus would be insufficient to measurably improve water quality.A straightforward pollutant input accounting approach is presented in the form of an existing model (WATERSHED) that has been adapted to run on modern electronic spreadsheets. As an application, WATERSHED is used to assess options to improve the quality of highly eutrophic Delavan Lake in Wisconsin. WATERSHED is flexible in that several techniques, such as the Universal Soil Loss Equation or unit-area loadings, can be used to estimate nonpoint-source inputs. Once the model parameters are determined (and calibrated, if possible), the spreadsheet features can be used to conduct a sensitivity analysis of management options. In the case of Delavan Lake, it was concluded that, although some nonpoint controls were cost-effective, the overall reduction in phosphorus would be insufficient to measurably improve water quality.

Analysis Of Leakage In Carbon Sequestration Projects In Forestry:A Case Study Of Upper Magat Watershed, Philippines

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

Lasco, Rodel D.; Pulhin, Florencia B.; Sales, Renezita F.

2007-06-01

The role of forestry projects in carbon conservation andsequestration is receiving much attention because of their role in themitigation of climate change. The main objective of the study is toanalyze the potential of the Upper Magat Watershed for a carbonsequestration project. The three main development components of theproject are forest conservation, tree plantations, and agroforestry farmdevelopment. At Year 30, the watershed can attain a net carbon benefit of19.5 M tC at a cost of US$ 34.5 M. The potential leakage of the projectis estimated using historical experience in technology adoption inwatershed areas in the Philippines and a high adoption rate.more » Two leakagescenarios were used: baseline and project leakage scenarios. Most of theleakage occurs in the first 10 years of the project as displacement oflivelihood occurs during this time. The carbon lost via leakage isestimated to be 3.7 M tC in the historical adoption scenario, and 8.1 MtC under the enhanced adoption scenario.« less

Feasibility of estimate sediment yield in the non-sediment monitoring station area - A case study of Alishan River watershed,Taiwan

NASA Astrophysics Data System (ADS)

Chang, ChiaChi; Chan, HsunChuan; Jia, YaFei; Zhang, YaoXin

2017-04-01

Due to the steep topography, frail geology and concentrated rainfall in wet season, slope disaster occurred frequently in Taiwan. In addition, heavy rainfall induced landslides in upper watersheds. The sediment yield on the slopeland affects the sediment transport in the river. Sediment deposits on the river bed reduce the river cross section and change the flow direction. Furthermore, it generates risks to residents' lives and property in the downstream. The Taiwanese government has been devoting increasing efforts on the sedimentary management issues and on reduction in disaster occurrence. However, due to the limited information on the environmental conditions in the upper stream, it is difficult to set up the sedimentary monitoring equipment. This study used the upper stream of the Qingshuei River, the Alishan River, as a study area. In August 2009, Typhoon Morakot caused the sedimentation of midstream and downstream river courses in the Alishan River. Because there is no any sediment monitoring stations within the Alishan River watershed, the sediment yield values are hard to determine. The objective of this study is to establish a method to analyze the event-landslide sediment transport in the river on the upper watershed. This study numerically investigated the sediment transport in the Alishan River by using the KINEROS 2 model developed by the United States Department of Agriculture and the CCHE1D model developed by the National Center for Computational Hydroscience and Engineering. The simulated results represent the morphology changes in the Alishan River during the typhoon events. The results consist of a critical strategy reference for the sedimentary management for the Alishan River watershed.

Development of a hydrological model for simulation of runoff from catchments unbounded by ridge lines

NASA Astrophysics Data System (ADS)

Vema, Vamsikrishna; Sudheer, K. P.; Chaubey, I.

2017-08-01

Watershed hydrological models are effective tools for simulating the hydrological processes in the watershed. Although there are a plethora of hydrological models, none of them can be directly applied to make water conservation decisions in irregularly bounded areas that do not confirm to topographically defined ridge lines. This study proposes a novel hydrological model that can be directly applied to any catchment, with or without ridge line boundaries. The model is based on the water balance concept, and a linear function concept to approximate the cross-boundary flow from upstream areas to the administrative catchment under consideration. The developed model is tested in 2 watersheds - Riesel Experimental Watershed and a sub-basin of Cedar Creek Watershed in Texas, USA. Hypothetical administrative catchments that did not confirm to the location of ridge lines were considered for verifying the efficacy of the model for hydrologic simulations. The linear function concept used to account the cross boundary flow was based on the hypothesis that the flow coming from outside the boundary to administrative area was proportional to the flow generated in the boundary grid cell. The model performance was satisfactory with an NSE and r2 of ≥0.80 and a PBIAS of <25 in all the cases. The simulated hydrographs for the administrative catchments of the watersheds were in good agreement with the observed hydrographs, indicating a satisfactory performance of the model in the administratively bounded areas.

Manage Hydrologic Fluxes Instead of Land Cover in Watershed Services Projects

NASA Astrophysics Data System (ADS)

Brauman, K. A.; Ponette-González, A. G.; Marin-Spiotta, E.; Farley, K. A.; Weathers, K. C.; Young, K. R.; Curran, L. M.

2014-12-01

Payments for Watershed Services (PWS), Water Funds, and other payment schemes intended to increase the delivery of hydrologic ecosystem services have great potential for ensuring water resources for downstream beneficiaries while improving livelihoods for upstream residents. However, it is often ambiguous which land-management options should be promoted to enhance watershed service delivery. In many watershed investment programs, specific land covers are promoted as proxies for water service delivery. This approach is based on assumed relationships between land cover and water service outcomes. When land cover does not sufficiently describe ecosystem characteristics that affect water flow, however, desired water services may not be delivered. The use of land cover proxies is especially problematic for watershed investments in the tropics, where many projects are located, because these proxies rely on generalizations about landscape hydrology established for temperate zones. Based on an extensive review of hydrologic fluxes in the high-elevation tropics, we argue that direct management of hydrologic fluxes is a good design for achieving quantifiable results. We use case studies from sites in the Caribbean and Latin American tropics to illustrate how designers of watershed payment projects can manage hydrologic fluxes. To do so, projects must explicitly articulate the water service of interest based on the specific social setting. Projects must also explicitly account for the particulars of the geographic setting. Finally, outcomes must be assessed relative to water services delivered under an alternative land use or land cover scenario.

ENVIRONMENTAL ECONOMICS FOR WATERSHED RESTORATION

EPA Science Inventory

This book overviews non-market valuation, input-output analysis, cost-benefit analysis, and presents case studies from the Mid Atlantic Highland region, with all but the bare minimum econometrics, statistics, and math excluded or relegated to an appendix. It is a non-market valu...

Bioenergy Development Policy and Practice Must Recognize Potential Hydrologic Impacts: Lessons from the Americas.

PubMed

Watkins, David W; de Moraes, Márcia M G Alcoforado; Asbjornsen, Heidi; Mayer, Alex S; Licata, Julian; Lopez, Jose Gutierrez; Pypker, Thomas G; Molina, Vivianna Gamez; Marques, Guilherme Fernandes; Carneiro, Ana Cristina Guimaraes; Nuñez, Hector M; Önal, Hayri; da Nobrega Germano, Bruna

2015-12-01

Large-scale bioenergy production will affect the hydrologic cycle in multiple ways, including changes in canopy interception, evapotranspiration, infiltration, and the quantity and quality of surface runoff and groundwater recharge. As such, the water footprints of bioenergy sources vary significantly by type of feedstock, soil characteristics, cultivation practices, and hydro-climatic regime. Furthermore, water management implications of bioenergy production depend on existing land use, relative water availability, and competing water uses at a watershed scale. This paper reviews previous research on the water resource impacts of bioenergy production-from plot-scale hydrologic and nutrient cycling impacts to watershed and regional scale hydro-economic systems relationships. Primary gaps in knowledge that hinder policy development for integrated management of water-bioenergy systems are highlighted. Four case studies in the Americas are analyzed to illustrate relevant spatial and temporal scales for impact assessment, along with unique aspects of biofuel production compared to other agroforestry systems, such as energy-related conflicts and tradeoffs. Based on the case studies, the potential benefits of integrated resource management are assessed, as is the need for further case-specific research.

Bioenergy Development Policy and Practice Must Recognize Potential Hydrologic Impacts: Lessons from the Americas

NASA Astrophysics Data System (ADS)

Watkins, David W.; de Moraes, Márcia M. G. Alcoforado; Asbjornsen, Heidi; Mayer, Alex S.; Licata, Julian; Lopez, Jose Gutierrez; Pypker, Thomas G.; Molina, Vivianna Gamez; Marques, Guilherme Fernandes; Carneiro, Ana Cristina Guimaraes; Nuñez, Hector M.; Önal, Hayri; da Nobrega Germano, Bruna

2015-12-01

Large-scale bioenergy production will affect the hydrologic cycle in multiple ways, including changes in canopy interception, evapotranspiration, infiltration, and the quantity and quality of surface runoff and groundwater recharge. As such, the water footprints of bioenergy sources vary significantly by type of feedstock, soil characteristics, cultivation practices, and hydro-climatic regime. Furthermore, water management implications of bioenergy production depend on existing land use, relative water availability, and competing water uses at a watershed scale. This paper reviews previous research on the water resource impacts of bioenergy production—from plot-scale hydrologic and nutrient cycling impacts to watershed and regional scale hydro-economic systems relationships. Primary gaps in knowledge that hinder policy development for integrated management of water-bioenergy systems are highlighted. Four case studies in the Americas are analyzed to illustrate relevant spatial and temporal scales for impact assessment, along with unique aspects of biofuel production compared to other agroforestry systems, such as energy-related conflicts and tradeoffs. Based on the case studies, the potential benefits of integrated resource management are assessed, as is the need for further case-specific research.

Concentration-discharge relationships in headwater streams of the Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Hunsaker, Carolyn T.; Johnson, Dale W.

2017-09-01

We examined stream water concentration-discharge relationships for eight small, forest watersheds ranging in elevation from 1485 to 2465 m in the southern Sierra Nevada. These headwater streams revealed nearly chemostatic behavior by current definitions for K+, Ca2+, Mg2+, Na+, Cl-, and SO42- in most cases but not for NH4+, NO3-, or ortho-P. The latter ions were somewhat enriched during high flows. All ions studied showed a dilution process at lower flows (<50 L s-1) with the concentration-discharge relationship being more chemostatic at higher flows. While previous studies in the Sierra Nevada have reported peak concentrations of NH4+, NO3-, and SO42- during snowmelt, the headwater systems of the Kings River Experimental Watersheds experience peak concentrations of these ions during the fall rains after the dry summer. These forested watersheds span the rain-snow transition zone, are 49-228 ha in size, and have soils derived from granite. A statistically significant relationship between soils and stream water concentrations for ortho-P, Ca2+, and Na+ strongly suggests that soil chemistry has a major influence on stream water chemistry. Factors controlling stream water NH4+, NO3-, and SO42- concentrations are less clear, but one possible source of spikes in these ions during storm events is input from O-horizon runoff where high concentrations were measured. Overall, stream water concentration-discharge relationships for these Sierran watersheds are similar to those found in other watershed systems (nearly chemostatic); however, the dominant processes controlling these relationships are probably localized because of different watershed characteristics like soil chemistry, vegetation cover, hydrologic flow paths, and weather patterns.

Recent Approaches to Modeling Transport of Mercury in Surface Water and Groundwater - Case Study in Upper East Fork Poplar Creek, Oak Ridge, TN - 13349

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

Bostick, Kent; Daniel, Anamary; Tachiev, Georgio

2013-07-01

In this case study, groundwater/surface water modeling was used to determine efficacy of stabilization in place with hydrologic isolation for remediation of mercury contaminated areas in the Upper East Fork Poplar Creek (UEFPC) Watershed in Oak Ridge, TN. The modeling simulates the potential for mercury in soil to contaminate groundwater above industrial use risk standards and to contribute to surface water contamination. The modeling approach is unique in that it couples watershed hydrology with the total mercury transport and provides a tool for analysis of changes in mercury load related to daily precipitation, evaporation, and runoff from storms. The modelmore » also allows for simulation of colloidal transport of total mercury in surface water. Previous models for the watershed only simulated average yearly conditions and dissolved concentrations that are not sufficient for predicting mercury flux under variable flow conditions that control colloidal transport of mercury in the watershed. The transport of mercury from groundwater to surface water from mercury sources identified from information in the Oak Ridge Environmental Information System was simulated using a watershed scale model calibrated to match observed daily creek flow, total suspended solids and mercury fluxes. Mercury sources at the former Building 81-10 area, where mercury was previously retorted, were modeled using a telescopic refined mesh with boundary conditions extracted from the watershed model. Modeling on a watershed scale indicated that only source excavation for soils/sediment in the vicinity of UEFPC had any effect on mercury flux in surface water. The simulations showed that colloidal transport contributed 85 percent of the total mercury flux leaving the UEFPC watershed under high flow conditions. Simulation of dissolved mercury transport from liquid elemental mercury and adsorbed sources in soil at former Building 81-10 indicated that dissolved concentrations are orders of magnitude below a target industrial groundwater concentration beneath the source and would not influence concentrations in surface water at Station 17. This analysis addressed only shallow concentrations in soil and the shallow groundwater flow path in soil and unconsolidated sediments to UEFPC. Other mercury sources may occur in bedrock and transport though bedrock to UEFPC may contribute to the mercury flux at Station 17. Generally mercury in the source areas adjacent to the stream and in sediment that is eroding can contribute to the flux of mercury in surface water. Because colloidally adsorbed mercury can be transported in surface water, actions that trap colloids and or hydrologically isolate surface water runoff from source areas would reduce the flux of mercury in surface water. Mercury in soil is highly adsorbed and transport in the groundwater system is very limited under porous media conditions. (authors)« less

Evaluation of morphometric parameters derived from Cartosat-1 DEM using remote sensing and GIS techniques for Budigere Amanikere watershed, Dakshina Pinakini Basin, Karnataka, India

NASA Astrophysics Data System (ADS)

Dikpal, Ramesh L.; Renuka Prasad, T. J.; Satish, K.

2017-12-01

The quantitative analysis of drainage system is an important aspect of characterization of watersheds. Using watershed as a basin unit in morphometric analysis is the most logical choice because all hydrological and geomorphic processes occur within the watershed. The Budigere Amanikere watershed a tributary of Dakshina Pinakini River has been selected for case illustration. Geoinformatics module consisting of ArcGIS 10.3v and Cartosat-1 Digital Elevation Model (DEM) version 1 of resolution 1 arc Sec ( 32 m) data obtained from Bhuvan is effectively used. Sheet and gully erosion are identified in parts of the study area. Slope in the watershed indicating moderate to least runoff and negligible soil loss condition. Third and fourth-order sub-watershed analysis is carried out. Mean bifurcation ratio ( R b) 3.6 specify there is no dominant influence of geology and structures, low drainage density ( D d) 1.12 and low stream frequency ( F s) 1.17 implies highly infiltration subsoil material and low runoff, infiltration number ( I f)1.3 implies higher infiltration capacity, coarse drainage texture ( T) 3.40 shows high permeable subsoil, length of overland flow ( L g) 0.45 indicates under very less structural disturbances, less runoff conditions, constant of channel maintenance ( C) 0.9 indicates higher permeability of subsoil, elongation ratio ( R e) 0.58, circularity ratio ( R c) 0.75 and form factor ( R f) 0.26 signifies sub-circular to more elongated basin with high infiltration with low runoff. It was observed from the hypsometric curves and hypsometric integral values of the watershed along with their sub basins that the drainage system is attaining a mature stage of geomorphic development. Additionally, Hypsometric curve and hypsometric integral value proves that the infiltration capacity is high as well as runoff is low in the watershed. Thus, these mormometric analyses can be used as an estimator of erosion status of watersheds leading to prioritization for taking up soil and water conservation measures.

Epistemic Agency in an Environmental Sciences Watershed Investigation Fostered by Digital Photography

ERIC Educational Resources Information Center

Zimmerman, Heather Toomey; Weible, Jennifer L.

2018-01-01

This collective case study investigates the role of digital photography to support high school students' engagement in science inquiry practices during a three-week environmental sciences unit. The study's theoretical framework brings together research from digital photography, participation in environmental science practices, and epistemic…

DEVELOPING TOOLS FOR EVALUATION OF INTERACTIONS BETWEEN GLOBAL CHANGE STRESSORS AND ECOSYSTEM FUNCTIONING

EPA Science Inventory

Case studies in key selected coral reefs and watersheds will be completed to provide scientific data, concepts and models that describe the responses of the functioning of these ecosystems to global change stressors. The studies will focus on relating global changes to local and...

Participatory Systems Modeling to Explore Sustainable Solutions: Triple Value Simulation Modeling Cases Tackle Nutrient and Watershed Management from a Socio-Ecological Systems (SES) perspective

EPA Science Inventory

Decision makers often need assistance in understanding dynamic interactions and linkages among economic, environmental and social systems in coastal watersheds. They also need scientific input to better evaluate potential costs and benefits of alternative policy interventions. Th...

Nimbus hydrological observations over the watersheds of the Niger and Indus rivers

NASA Technical Reports Server (NTRS)

Salomonson, V. V.; Macleod, N. H.

1972-01-01

As a result of studying the Nimbus imagery over these two watersheds, it is felt that a perspective and understanding of the large scale hydrological processes and their interrelationship has been obtained which could be obtained by no other means in so short a time. In the case of the Niger River a much better appreciation of the flooding process has been obtained along with the role of the Inland Delta in this process. Obviously a knowledge of the spatial and temporal distribution of the snow-melt process in the Indus River watershed is now available that was obtained with minimal effort, as compared to the effort and time that would be required using conventional methods. It seems clear that even the low resolution data easily available from meteorological satellites can be a valuable source of information in the better management of the water resources in these regions.

Spatial patterns of soil nutrients and groundwater levels within the Debre Mawi watershed of the Ethiopian highlands

NASA Astrophysics Data System (ADS)

Guzman, Christian; Tilahun, Seifu; Dagnew, Dessalegn; Zegeye, Assefe; Tebebu, Tigist; Yitaferu, Birru; Steenhuis, Tammo

2015-04-01

Persistent patterns of erosion have emerged in the Ethiopian highlands leading to soil and water conservation practices being implemented throughout the countryside. A common concern is the loss of soil fertility and loss of soil water. This study investigates the spatial patterns of soil nutrients and water table depths in a small sub-watershed in the northwestern Ethiopian highlands. NPK, a particularly important group of nutrients for inorganic fertilizer considerations, did not follow a consistent trend as a group along and across slope and land use transects. Whereas nitrogen content was greatest in the upslope regions (~0.1% TN), available phosphorus had comparably similar content in the different slope regions throughout the watershed (~2.7 mg/kg). The exchangeable cations (K, Ca, Mg) did increase in content in a downslope direction (in most cases though, they were highest in the middle region) but not consistently later in the season. On average, calcium (40 cmol/kg), magnesium (5 cmol/kg), and potassium (0.5 cmol/kg) were orders of magnitudes different in content. The perched water table in different areas of the watershed showed a very distinct trend. The lower part of the sub-watershed had shallower levels of water table depths (less than 10 cm from the surface) than did the upper parts of the sub-watershed (usually greater than 120 cm from the surface). The middle part of the sub-watershed had water table depths located at 40 to 70 cm below the surface. These results show how the landscape slope position and land use may be important for planning where and when soil nutrients and water would be expected to be appropriately "conserved" or stored.

Awareness and Adoption of Soil and Water Conservation Technologies in a Developing Country: A Case of Nabajuzi Watershed in Central Uganda

NASA Astrophysics Data System (ADS)

Kagoya, Sarah; Paudel, Krishna P.; Daniel, Nadhomi L.

2018-02-01

Soil and water conservation technologies have been widely available in most parts of Uganda. However, not only has the adoption rate been low but also many farmers seem not to be aware of these technologies. This study aims at identifying the factors that influence awareness and adoption of soil and water conservation technologies in Nabajuzi watershed in central Uganda. A bivariate probit model was used to examine farmers' awareness and adoption of soil and water conservation technologies in the watershed. We use data collected from the interview of 400 households located in the watershed to understand the factors affecting the awareness and adoption of these technologies in the study area. Findings indicate that the likelihood of being aware and adopting the technologies are explained by the age of household head, being a tenant, and number of years of access to farmland. To increase awareness and adoption of technologies in Uganda, policymakers may expedite the process of land titling as farmers may feel secure about landholding and thus adopt these technologies to increase profitability and productivity in the long run. Incentive payments to farmers residing in the vulnerable region to adopt these considered technologies may help to alleviate soil deterioration problems in the affected area.

Land cover change impact on urban flood modeling (case study: Upper Citarum watershed)

NASA Astrophysics Data System (ADS)

Siregar, R. I.

2018-03-01

The upper Citarum River watershed utilizes remote sensing technology in Geographic Information System to provide information on land coverage by interpretation of objects in the image. Rivers that pass through urban areas will cause flooding problems causing disadvantages, and it disrupts community activities in the urban area. Increased development in a city is related to an increase in the number of population growth that added by increasing quality and quantity of life necessities. Improved urban lifestyle changes have an impact on land cover. The impact in over time will be difficult to control. This study aims to analyze the condition of flooding in urban areas caused by upper Citarum watershed land-use change in 2001 with the land cover change in 2010. This modeling analyzes with the help of HEC-RAS to describe flooded inundation urban areas. Land cover change in upper Citarum watershed is not very significant; it based on the results of data processing of land cover has the difference of area that changed is not enormous. Land cover changes for the floods increased dramatically to a flow coefficient for 2001 is 0.65 and in 2010 at 0.69. In 2001, the inundation area about 105,468 hectares and it were about 92,289 hectares in 2010.

Awareness and Adoption of Soil and Water Conservation Technologies in a Developing Country: A Case of Nabajuzi Watershed in Central Uganda.

PubMed

Kagoya, Sarah; Paudel, Krishna P; Daniel, Nadhomi L

2018-02-01

Soil and water conservation technologies have been widely available in most parts of Uganda. However, not only has the adoption rate been low but also many farmers seem not to be aware of these technologies. This study aims at identifying the factors that influence awareness and adoption of soil and water conservation technologies in Nabajuzi watershed in central Uganda. A bivariate probit model was used to examine farmers' awareness and adoption of soil and water conservation technologies in the watershed. We use data collected from the interview of 400 households located in the watershed to understand the factors affecting the awareness and adoption of these technologies in the study area. Findings indicate that the likelihood of being aware and adopting the technologies are explained by the age of household head, being a tenant, and number of years of access to farmland. To increase awareness and adoption of technologies in Uganda, policymakers may expedite the process of land titling as farmers may feel secure about landholding and thus adopt these technologies to increase profitability and productivity in the long run. Incentive payments to farmers residing in the vulnerable region to adopt these considered technologies may help to alleviate soil deterioration problems in the affected area.

Data management to enhance long-term watershed research capacity: context and STWEARDS case study

USDA-ARS?s Scientific Manuscript database

Water resources are under growing pressure globally, and in the face of projected climate change, uncertainty about precipitation frequency and intensity; evapotranspiration, runoff, and snowmelt poses severe societal challenges. Interdisciplinary environmental research across natural and social sc...

Environmental Economics for Watershed Restoration: Valuation for Non-Economists

EPA Science Inventory

EPA economists completed research projects and summarized related valuation methods and case studies, mostly dealing with acid mine drainage. Their recent book (edited by Thurston, et al.) is intended to make stakeholders more comfortable talking about economic jargon and to info...

Dynamics of Soil Erosion as Influenced by Watershed Management Practices: A Case Study of the Agula Watershed in the Semi-Arid Highlands of Northern Ethiopia.

PubMed

Fenta, Ayele Almaw; Yasuda, Hiroshi; Shimizu, Katsuyuki; Haregeweyn, Nigussie; Negussie, Aklilu

2016-11-01

Since the past two decades, watershed management practices such as construction of stone bunds and establishment of exclosures have been widely implemented in the semi-arid highlands of northern Ethiopia to curb land degradation by soil erosion. This study assessed changes in soil erosion for the years 1990, 2000 and 2012 as a result of such watershed management practices in Agula watershed using the Revised Universal Soil Loss Equation. The Revised Universal Soil Loss Equation factors were computed in a geographic information system for 30 × 30 m raster layers using spatial data obtained from different sources. The results revealed significant reduction in soil loss rates by about 55 % from about 28 to 12 t ha -1 per year in 1990-2000 and an overall 64 % reduction from 28 to 10 t ha -1 per year in 1990-2012. This change in soil loss is attributed to improvement in surface cover and stone bund practices, which resulted in the decrease in mean C and P-factors, respectively, by about 19 % and 34 % in 1990-2000 and an overall decrease in C-factor by 29 % in 1990-2012. Considerable reductions in soil loss were observed from bare land (89 %), followed by cultivated land (56 %) and shrub land (49 %). Furthermore, the reduction in soil loss was more pronounced in steeper slopes where very steep slope and steep slope classes experienced over 70 % reduction. Validation of soil erosion estimations using field observed points showed an overall accuracy of 69 %, which is fairly satisfactory. This study demonstrated the potential of watershed management efforts to bring remarkable restoration of degraded semi-arid lands that could serve as a basis for sustainable planning of future developments of areas experiencing severe land degradation due to water erosion.

Studying Watersheds: A Confluence of Important Ideas. ERIC Digest.

ERIC Educational Resources Information Center

Haury, David L.

This digest explains how the study of watersheds can serve to connect concept and skill development across subject areas and grade levels for curriculum reform and standards-based assessment. Specific resources are organized into watersheds in the curriculum, connections to National Standards, watershed concepts and activities, watershed education…

Benefit Indicators for Flood Regulation Services of Wetlands: A Modeling Approach

EPA Science Inventory

This report describes a method for developing indicators of the benefits of flood regulation services of wetlands and presents a companion case study. We demonstrate our approach through an application to the Woonasquatucket River watershed in northern Rhode Island. This work is ...

Case study applications of the BASINS climate assessment tool (CAT)

EPA Science Inventory

This EPA report will illustrate the application of different climate assessment capabilities within EPA’s BASINS modeling system for assessing a range of potential questions about the effects of climate change on streamflow and water quality in different watershed settings and us...

Options for biodiversity conservation in managed forest landscapes of multiple ownerships in Oregon and Washington, USA.

Treesearch

N. Suzuki; D.H. Olson

2007-01-01

We review the policies and management approaches used in U.S. Pacific Northwest planted forest to address biodiversity protection. We provide a case-study watershed design from southern Oregon, integrating various stand-to-landscape biodiversity-management approaches.

USE OF WATERSHED CLASSIFICATION IN MONITORING FRAMEWORKS FOR THE WESTERN LAKE SUPERIOR BASIS

EPA Science Inventory

In this case study we predicted stream sensitivity to nonpoint source pollution based on the nonlinear responses of hydrologic regimes and associated loadings of nonpoint source pollutants to catchment properties. We assessed two hydrologically-based thresholds of impairment, on...

EFFECTS OF GEOMORPHIC PROCESSES AND HYDROLOGIC REGIMES ON RIPARIAN VEGETATION

EPA Science Inventory

In this chapter, the relationships among riparian vegetation and geomorphic and hydrologic processes in central Great Basin watersheds are evaluated over a range of scales. These relationships are examined through a series of case studies that have been conducted by the Great Ba...

A CASE STUDY OF NONPOINT SOURCES BACTERIAL CONTRIBUTION TO RURAL SURFACE WATER

EPA Science Inventory

The presentation will address several bacterial issues affecting the Turkey Creek (TC) watershed, in north central Ok. Our results from seasonal stream Escherichia coli (E. coli) analysis, bacterial source tracking, and antibiotic resistance will be shared and discussed in relat...

Relating landscape characteristics to non-point source pollution in mine waste-located watersheds using geospatial techniques.

PubMed

Xiao, Huaguo; Ji, Wei

2007-01-01

Landscape characteristics of a watershed are important variables that influence surface water quality. Understanding the relationship between these variables and surface water quality is critical in predicting pollution potential and developing watershed management practices to eliminate or reduce pollution risk. To understand the impacts of landscape characteristics on water quality in mine waste-located watersheds, we conducted a case study in the Tri-State Mining District which is located in the conjunction of three states (Missouri, Kansas and Oklahoma). Severe heavy metal pollution exists in that area resulting from historical mining activities. We characterized land use/land cover over the last three decades by classifying historical multi-temporal Landsat imagery. Landscape metrics such as proportion, edge density and contagion were calculated based on the classified imagery. In-stream water quality data over three decades were collected, including lead, zinc, iron, cadmium, aluminum and conductivity which were used as key water quality indicators. Statistical analyses were performed to quantify the relationship between landscape metrics and surface water quality. Results showed that landscape characteristics in mine waste-located watersheds could account for as much as 77% of the variation of water quality indicators. A single landscape metric alone, such as proportion of mine waste area, could be used to predict surface water quality; but its predicting power is limited, usually accounting for less than 60% of the variance of water quality indicators.

Enhanced nonlinearity interval mapping scheme for high-performance simulation-optimization of watershed-scale BMP placement

NASA Astrophysics Data System (ADS)

Zou, Rui; Riverson, John; Liu, Yong; Murphy, Ryan; Sim, Youn

2015-03-01

Integrated continuous simulation-optimization models can be effective predictors of a process-based responses for cost-benefit optimization of best management practices (BMPs) selection and placement. However, practical application of simulation-optimization model is computationally prohibitive for large-scale systems. This study proposes an enhanced Nonlinearity Interval Mapping Scheme (NIMS) to solve large-scale watershed simulation-optimization problems several orders of magnitude faster than other commonly used algorithms. An efficient interval response coefficient (IRC) derivation method was incorporated into the NIMS framework to overcome a computational bottleneck. The proposed algorithm was evaluated using a case study watershed in the Los Angeles County Flood Control District. Using a continuous simulation watershed/stream-transport model, Loading Simulation Program in C++ (LSPC), three nested in-stream compliance points (CP)—each with multiple Total Maximum Daily Loads (TMDL) targets—were selected to derive optimal treatment levels for each of the 28 subwatersheds, so that the TMDL targets at all the CP were met with the lowest possible BMP implementation cost. Genetic Algorithm (GA) and NIMS were both applied and compared. The results showed that the NIMS took 11 iterations (about 11 min) to complete with the resulting optimal solution having a total cost of 67.2 million, while each of the multiple GA executions took 21-38 days to reach near optimal solutions. The best solution obtained among all the GA executions compared had a minimized cost of 67.7 million—marginally higher, but approximately equal to that of the NIMS solution. The results highlight the utility for decision making in large-scale watershed simulation-optimization formulations.

Imbalances of Water and Solutes in Experimental Watersheds: Spatial or Temporal Origin?

NASA Astrophysics Data System (ADS)

Ruiz, L.; Fovet, O.; Sekhar, M.; Riotte, J.; Braun, J.; Gascuel-odoux, C.; Durand, P.

2012-12-01

Experimental watersheds where originally conceived as a tool to measure water balance in different landscapes and climates and in particular evapotranspiration fluxes. Pioneering experimentalists where paying attention to all possible causes of unmeasured losses, for example by ensuring that the watershed outlet was lying on impervious bedrock and that the hydrological boundary was consistent with the topographic divide. Nowadays, watershed studies encompass a large range of objectives, from hydrological process quantification, to diffuse pollution assessment. In many cases, the above-mentioned experimental precautions are not much considered and the closure of the water balance is rarely achieved, although this fact is even more rarely publicized in the scientific communications. As a consequence, it is very often very difficult to determine whether an observed difference between input and output of water or solutes is due to some hidden deep losses or to variation of storage in internal compartments of the watershed. In this presentation, we will discuss this issue based on long term hydrological and geochemical monitoring of experimental watersheds belonging to the research observatories BVET (http://bvet.omp.obs-mip.fr/ ) in South India and AgrHys (http://www.inra.fr/ore_agrhys/) in Western France. In the South Indian forested watershed of Mule Hole (10 years of monitoring) we demonstrated that transpiration by deep tree roots was a significant component of the water balance, and that the main pathway for hydrological and geochemical fluxes was groundwater underflow. In the French agricultural watersheds of Kerbernez and Kerrien (20 years of monitoring) significant water and solute losses through groundwater underflow was also demonstrated. In both sites, a model with flexible structure was calibrated and validated on the observation and then long-term simulations were produced using available long term weather data series of 50 years. Results demonstrated that the water or solute imbalances at the watershed scale depended, to a large extent, on the duration considered in the analysis. In the Mule Hole watershed, water storage in the unsaturated weathered bedrock was the major cause of water imbalance for short time series (less than 10 years) while deep loses were the only source of imbalance for long term analysis (more than 30 years). On the contrary, in the Kerrien and Kerbernez watersheds, solute imbalance were mainly attributed to underflow for short term analysis (less than 10 years) while variation of solute storage in the weathered bedrock became a major source of imbalance for long term analysis (more than 20 years). Discussion will focus on the consequences of these results on the validity of the hypotheses used in hydrological and hydrochemical modeling studies, and on the interest of long term environmental observatories for understanding water and element cycles.

Public Health Perspectives of Channelized and Unchannelized Headwater Streams in Central Ohio: A Case Study

USDA-ARS?s Scientific Manuscript database

Headwater streams constitute the majority of watersheds in the United States and many headwater streams in the midwest have been channelized for agricultural drainage. Public health implications of water chemistry and aquatic macroinvertebrates within channelized and unchannelized headwater streams ...

Software for calculating vegetation disturbance and recovery by using the equivalent clearcut area model.

Treesearch

Alan A. Ager; Caty Clifton

2005-01-01

The use of cumulative watershed effects models is mandated as part of interagency consultation over projects that might affect habitat for salmonids federally listed as threatened or endangered. Cumulative effects analysis is also required by a number of national forest plans in the Pacific Northwest Region (Region 6). Cumulative watershed effects in many cases are...

The politics of participation in watershed modeling.

PubMed

Korfmacher, K S

2001-02-01

While researchers and decision-makers increasingly recognize the importance of public participation in environmental decision-making, there is less agreement about how to involve the public. One of the most controversial issues is how to involve citizens in producing scientific information. Although this question is relevant to many areas of environmental policy, it has come to the fore in watershed management. Increasingly, the public is becoming involved in the sophisticated computer modeling efforts that have been developed to inform watershed management decisions. These models typically have been treated as technical inputs to the policy process. However, model-building itself involves numerous assumptions, judgments, and decisions that are relevant to the public. This paper examines the politics of public involvement in watershed modeling efforts and proposes five guidelines for good practice for such efforts. Using these guidelines, I analyze four cases in which different approaches to public involvement in the modeling process have been attempted and make recommendations for future efforts to involve communities in watershed modeling. Copyright 2001 Springer-Verlag

Application of WATERSHED ECOLOGICAL RISK ASSESSMENT Methods to Watershed Management

EPA Science Inventory

Watersheds are frequently used to study and manage environmental resources because hydrologic boundaries define the flow of contaminants and other stressors. Ecological assessments of watersheds are complex because watersheds typically overlap multiple jurisdictional boundaries,...

Application of Watershed Ecological Risk Assessment Methods to Watershed Management

EPA Science Inventory

Watersheds are frequently used to study and manage environmental resources because hydrologic boundaries define the flow of contaminants and other stressors. Ecological assessments of watersheds are complex because watersheds typically overlap multiple jurisdictional boundaries,...

Runoff potentiality of a watershed through SCS and functional data analysis technique.

PubMed

Adham, M I; Shirazi, S M; Othman, F; Rahman, S; Yusop, Z; Ismail, Z

2014-01-01

Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling.

Runoff Potentiality of a Watershed through SCS and Functional Data Analysis Technique

PubMed Central

Adham, M. I.; Shirazi, S. M.; Othman, F.; Rahman, S.; Yusop, Z.; Ismail, Z.

2014-01-01

Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling. PMID:25152911

Historical wildfire impacts on ponderosa pine tree overstories: An Arizona case study

Treesearch

Peter F. Ffolliott; Cody L. Stropki; Daniel G. Neary

2008-01-01

The Rodeo-Chediski Wildfire--the largest in Arizona's history--damaged or destroyed ecosystem resources and disrupted ecosystem functioning in a largely mosaic pattern throughout the ponderosa pine (Pinus ponderosa) forests exposed to the burn. Impacts of this wildfire on tree overstories were studied for 5 years (2002 to 2007) on two watersheds...

Stripcut-thinning of ponderosa pine stands: An Arizona case study

Treesearch

Peter F. Ffolliott; Malchus Baker

2001-01-01

Growth and structural changes in ponderosa pine (Pinus ponderosa) stands were studied over a 25-year posttreatment period to determine the impacts of a combined stripcut-thinning treatment. Trees on one-third of a watershed in north-central Arizona had been removed in clear-cut strips. Trees in the "leave" strips were thinned. Number of...

Flood risk reduction and flow buffering as ecosystem services - Part 2: Land use and rainfall intensity effects in Southeast Asia

NASA Astrophysics Data System (ADS)

van Noordwijk, Meine; Tanika, Lisa; Lusiana, Betha

2017-05-01

Watersheds buffer the temporal pattern of river flow relative to the temporal pattern of rainfall. This ecosystem service is inherent to geology and climate, but buffering also responds to human use and misuse of the landscape. Buffering can be part of management feedback loops if salient, credible and legitimate indicators are used. The flow persistence parameter Fp in a parsimonious recursive model of river flow (Part 1, van Noordwijk et al., 2017) couples the transmission of extreme rainfall events (1 - Fp), to the annual base-flow fraction of a watershed (Fp). Here we compare Fp estimates from four meso-scale watersheds in Indonesia (Cidanau, Way Besai and Bialo) and Thailand (Mae Chaem), with varying climate, geology and land cover history, at a decadal timescale. The likely response in each of these four to variation in rainfall properties (including the maximum hourly rainfall intensity) and land cover (comparing scenarios with either more or less forest and tree cover than the current situation) was explored through a basic daily water-balance model, GenRiver. This model was calibrated for each site on existing data, before being used for alternative land cover and rainfall parameter settings. In both data and model runs, the wet-season (3-monthly) Fp values were consistently lower than dry-season values for all four sites. Across the four catchments Fp values decreased with increasing annual rainfall, but specific aspects of watersheds, such as the riparian swamp (peat soils) in Cidanau reduced effects of land use change in the upper watershed. Increasing the mean rainfall intensity (at constant monthly totals for rainfall) around the values considered typical for each landscape was predicted to cause a decrease in Fp values by between 0.047 (Bialo) and 0.261 (Mae Chaem). Sensitivity of Fp to changes in land use change plus changes in rainfall intensity depends on other characteristics of the watersheds, and generalisations made on the basis of one or two case studies may not hold, even within the same climatic zone. A wet-season Fp value above 0.7 was achievable in forest-agroforestry mosaic case studies. Inter-annual variability in Fp is large relative to effects of land cover change. Multiple (5-10) years of paired-plot data would generally be needed to reject no-change null hypotheses on the effects of land use change (degradation and restoration). Fp trends over time serve as a holistic scale-dependent performance indicator of degrading/recovering watershed health and can be tested for acceptability and acceptance in a wider social-ecological context.

Evaluating Biodiversity Response toForecasted Land Use Change: A Case Study in the South Platte River Basin, Colorado

EPA Science Inventory

Effects of future land use change on watersheds have important management implications. Seamless, national-scale land-use-change scenarios for developed land were acquired from the U.S. Environmental Protection Agency Integrated Climate and Land Use Scenarios (lCLUS) project and...

Management and climate change in coastal Oregon forests: The Panther Creek Watershed as a case study

EPA Science Inventory

The highly productive forests of the Oregon Coast Range Mountains have been intensively harvested for many decades, and recent interest has emerged in the potential for removing harvest residue as a source of renewable woody biomass energy. However, the long-term consequences of ...

DOTAGWA: A CASE STUDY IN WEB-BASED ARCHITECTURES FOR CONNECTING SURFACE WATER MODELS TO SPATIALLY ENABLED WEB APPLICATIONS

EPA Science Inventory

The Automated Geospatial Watershed Assessment (AGWA) tool is a desktop application that uses widely available standardized spatial datasets to derive inputs for multi-scale hydrologic models (Miller et al., 2007). The required data sets include topography (DEM data), soils, clima...

REGIONAL ASSESSMENT OF FISH HEALTH: A PROTOTYPE METHODOLOGY AND CASE STUDY FOR THE ALBEMARLE-PAMLICO RIVER BASIN, NORTH CAROLINA

EPA Science Inventory

BASE (Basin-Scale Assessments for Sustainable Ecosystems) is a research program developed by the Ecosystems Research Division of the National Exposure Research Laboratory to explore and formulate approaches for assessing the sustainability of ecological resources within watershed...

Testing wetland axioms at a watershed scale: Case studies of the aggregate hydrologic effects of non-adjacent wetlands

EPA Science Inventory

Wetlands not adjacent to streams (i.e. “non-adjacent wetlands”) are hypothesized to affect downgradient hydrology in a number of ways. Non-adjacent wetlands may, for example, attenuate peak flows, serve as focal points for groundwater recharge, and decrease streamflow...

Water dynamics and population pressure in the Nepalese Himalayas.

PubMed

Schreier, H; Shah, P B

1996-10-01

The authors investigate the impact of water shortages, especially water for irrigation, on development in Nepal. "The problems associated with hydropower development will be illustrated by using the Kulekhani watershed project as a case study." The possible future effects on food supplies and health are discussed. excerpt

Scenarios and decisionmaking for complex environmental systems

Treesearch

Stephen R. Carpenter; Adena R. Rissman

2012-01-01

Scenarios are used for expanding the scope of imaginable outcomes considered by assessments, planning exercises, or research projects on social-ecological systems. We discuss a global case study, the Millennium Ecosystem Assessment, and a regional project for an urbanizing agricultural watershed. Qualitative and quantitative aspects of scenarios are complementary....

Appendix 5 Case Studies of Sampling and Monitoring

EPA Science Inventory

The North Fork of Clear Creek (NFCC), Colorado, is an acid-mine drainage impacted stream located approximately 48 km west of Denver, CO, is approximately 29 km long, and flows into the main stem of Clear Creek in Golden, CO. The entire Clear Creek watershed is a Superfund site, ...

Game theory and fuzzy programming approaches for bi-objective optimization of reservoir watershed management: a case study in Namazgah reservoir.

PubMed

Üçler, N; Engin, G Onkal; Köçken, H G; Öncel, M S

2015-05-01

In this study, game theory and fuzzy programming approaches were used to balance economic and environmental impacts in the Namazgah reservoir, Turkey. The main goals identified were to maximize economic benefits of land use and to protect water quality of reservoir and land resources. Total phosphorous load (kg ha(-1) year(-1)) and economic income (USD ha(-1) year(-1)) from land use were determined as environmental value and economic value, respectively. The surface area of existing land use types, which are grouped under 10 headings according to the investigations on the watershed area, and the constraint values for the watershed were calculated using aerial photos, master plans, and basin slope map. The results of fuzzy programming approach were found to be very close to the results of the game theory model. It was concluded that the amount of fertilizer used in the current situation presents a danger to the reservoir and, therefore, unnecessary fertilizer use should be prevented. Additionally, nuts, fruit, and vegetable cultivation, instead of wheat and corn cultivation, was found to be more suitable due to their high economic income and low total phosphorus (TP) load. Apart from agricultural activities, livestock farming should also be considered in the area as a second source of income. It is believed that the results obtained in this study will help decision makers to identify possible problems of the watershed.

Poverty within watershed and environmentally protected areas: the case of the indigenous community in Peninsular Malaysia.

PubMed

Kari, Fatimah Binti; Masud, Muhammad Mehedi; Yahaya, Siti Rohani Binti; Saifullah, Md Khaled

2016-03-01

"Indigenous people" have been acknowledged as among the poorest and most socio-economically and culturally marginalized all over the world. This paper explores the socio-economic status of the indigenous people and their poverty profile within watershed and environmentally protected areas in Peninsular Malaysia. The findings of the study indicate that the "indigenous community" is likely to be poor if they live in environmentally sensitive and unprotected areas as compared to families under the new resettlement scheme. Inadequate access to basic education and employment contributed significantly to their poor economic status. The findings further reveal that the indigenous community is facing difficulties in receiving access and support in terms of basic needs such as housing, education, economic livelihood, and other social infrastructure. Moreover, the regulatory structure for the management of watershed areas as well as the emphasis for commodity crops such as palm oil and natural rubber have indirectly contributed toward the poverty level of the indigenous people.

An auto-adaptive optimization approach for targeting nonpoint source pollution control practices.

PubMed

Chen, Lei; Wei, Guoyuan; Shen, Zhenyao

2015-10-21

To solve computationally intensive and technically complex control of nonpoint source pollution, the traditional genetic algorithm was modified into an auto-adaptive pattern, and a new framework was proposed by integrating this new algorithm with a watershed model and an economic module. Although conceptually simple and comprehensive, the proposed algorithm would search automatically for those Pareto-optimality solutions without a complex calibration of optimization parameters. The model was applied in a case study in a typical watershed of the Three Gorges Reservoir area, China. The results indicated that the evolutionary process of optimization was improved due to the incorporation of auto-adaptive parameters. In addition, the proposed algorithm outperformed the state-of-the-art existing algorithms in terms of convergence ability and computational efficiency. At the same cost level, solutions with greater pollutant reductions could be identified. From a scientific viewpoint, the proposed algorithm could be extended to other watersheds to provide cost-effective configurations of BMPs.

Spring floods prediction with the use of optical satellite data in Québec

NASA Astrophysics Data System (ADS)

Roy, A.; Royer, A.; Turcotte, R.

2009-04-01

The Centre d'expertise hydrique du Québec (CEHQ) operates a distributed hydrological model, which integrates a snow model, for the management of dams in the south of Québec. It appears that the estimation of the water quantity of snowmelt in spring remains a variable with a large uncertainty and induces generally to an important error in stream flow simulation. Therefore, the National snow and ice center (NSIDC) produces, from MODIS (Moderate Resolution Imaging Spectroradiometer) data, continuous and homogeneous spatial snow cover (snow/swow-free) data on the whole territory, but with a cloud contamination. This research aims to improve the prediction of spring floods and the estimation of the rate of discharge by integrating snow cover data in the CEHQ's snow model. The study is done on two watersheds: du Nord river watershed (45,8°N) and Aux Écorces river watershed (47,9°N). The snow model used in the study (SPH-AV) is an implementation developed by the CEHQ of the snowmelt model of HYDROLTEL in is hydrological forecast system to simulate the melted water. The melted water estimated is then used as input in the empirical hydrological model MOHYSE to simulate stream flow. MODIS data are considered valid only when the cloud cover on each pixel of the watersheds is less then 30%. A pixel by pixel correction is applied to the snow pack when there is a difference between satellite snow cover and modeled snow cover. In the case of model shows to much snow, a factor is applied on temperatures by iterative process (starting from the last valid MODIS data) to melt the snow. In the opposite case, the snow quantity added to the last valid MODIS data is found by iterative process so that the pixel's snow water equivalent is equal to the nonzero neighbor minimum value. The study shows, through the simulations done on the two watersheds, the interest of the use of snow/snow-free product for the operational update of snow water equivalent with the objective to improve spring snowmelt stream flow simulations. The binary aspect (snow/snowfree) of the data is however a limit. Alternatives are discussed (passive microwave data). Keywords : satellite snow cover data, MODIS, satellite data integration, snow model, hydrological model, stream flow simulation, flood.

Nitrogen fluxes and retention in urban watershed ecosystems

USGS Publications Warehouse

Groffman, P.M.; Law, N.L.; Belt, K.T.; Band, L.E.; Fisher, G.T.

2004-01-01

Although the watershed approach has long been used to study whole-ecosystem function, it has seldom been applied to study human-dominated systems, especially those dominated by urban and suburban land uses. Here we present 3 years of data on nitrogen (N) losses from one completely forested, one agricultural, and six urban/suburban watersheds, and input-output N budgets for suburban, forested, and agricultural watersheds. The work is a product of the Baltimore Ecosystem Study, a long-term study of urban and suburban ecosystems, and a component of the US National Science Foundation's long-term ecological research (LTER) network. As expected, urban and suburban watersheds had much higher N losses than did the completely forested watershed, with N yields ranging from 2.9 to 7.9 kg N ha-1 y-1 in the urban and suburban watersheds compared with less than 1 kg N ha-1 y -1 in the completely forested watershed. Yields from urban and suburban watersheds were lower than those from an agricultural watershed (13-19.8 kg N ha-1 y-1). Retention of N in the suburban watershed was surprisingly high, 75% of inputs, which were dominated by home lawn fertilizer (14.4 kg N ha-1 y-1) and atmospheric deposition (11.2 kg N ha-1 y-1). Detailed analysis of mechanisms of N retention, which must occur in the significant amounts of pervious surface present in urban and suburban watersheds, and which include storage in soils and vegetation and gaseous loss, is clearly warranted.

Mode Decomposition Methods for Soil Moisture Prediction

NASA Astrophysics Data System (ADS)

Jana, R. B.; Efendiev, Y. R.; Mohanty, B.

2014-12-01

Lack of reliable, well-distributed, long-term datasets for model validation is a bottle-neck for most exercises in soil moisture analysis and prediction. Understanding what factors drive soil hydrological processes at different scales and their variability is very critical to further our ability to model the various components of the hydrologic cycle more accurately. For this, a comprehensive dataset with measurements across scales is very necessary. Intensive fine-resolution sampling of soil moisture over extended periods of time is financially and logistically prohibitive. Installation of a few long term monitoring stations is also expensive, and needs to be situated at critical locations. The concept of Time Stable Locations has been in use for some time now to find locations that reflect the mean values for the soil moisture across the watershed under all wetness conditions. However, the soil moisture variability across the watershed is lost when measuring at only time stable locations. We present here a study using techniques such as Dynamic Mode Decomposition (DMD) and Discrete Empirical Interpolation Method (DEIM) that extends the concept of time stable locations to arrive at locations that provide not simply the average soil moisture values for the watershed, but also those that can help re-capture the dynamics across all locations in the watershed. As with the time stability, the initial analysis is dependent on an intensive sampling history. The DMD/DEIM method is an application of model reduction techniques for non-linearly related measurements. Using this technique, we are able to determine the number of sampling points that would be required for a given accuracy of prediction across the watershed, and the location of those points. Locations with higher energetics in the basis domain are chosen first. We present case studies across watersheds in the US and India. The technique can be applied to other hydro-climates easily.

Representation of regional urban development conditions using a watershed-based gradient study design

USGS Publications Warehouse

Terziotti, Silvia; McMahon, Gerard; Bell, Amanda H.

2012-01-01

As part of the U.S. Geological Survey National Water-Quality Assessment Program, the effects of urbanization on stream ecosystems (EUSE) have been intensively investigated in nine metropolitan areas in the United States, including Boston, Massachusetts; Atlanta, Georgia; Birmingham, Alabama; Raleigh, North Carolina; Salt Lake City, Utah; Denver, Colorado; Dallas–Fort Worth, Texas; Portland, Oregon; and Milwaukee–Green Bay, Wisconsin. Each of the EUSE study area watersheds was associated with one ecological region of the United States. This report evaluates whether each metropolitan area can be generalized across the ecological regions (ecoregions) within which the EUSE study watersheds are located. Seven characteristics of the EUSE watersheds that affect stream ecosystems were examined to determine the similarities in the same seven characteristics of the watersheds in the entire ecoregion. Land cover (percentage developed, forest and shrubland, and herbaceous and cultivated classes), average annual temperature, average annual precipitation, average surface elevation, and average percentage slope were selected as human-influenced, climate, and topography characteristics. Three findings emerged from this comparison that have implications for the use of EUSE data in models used to predict stream ecosystem condition. One is that the predominant or "background" land-cover type (either forested or agricultural land) in each ecoregion also is the predominant land-cover type within the associated EUSE study watersheds. The second finding is that in all EUSE study areas, the watersheds account for the range of developed land conditions that exist in the corresponding ecoregion watersheds. However, six of the nine EUSE study area watersheds have significantly different distributions of developed land from the ecoregion watersheds. Finally, in seven of the nine EUSE/ecoregion comparisons, the distributions of the values of climate variables in the EUSE watersheds are different from the distributions for watersheds in the corresponding ecoregions.

A paired-watershed budget study to quantify interbasin groundwater flow in a lowland rain forest, Costa Rica

NASA Astrophysics Data System (ADS)

Genereux, David P.; Jordan, Michael T.; Carbonell, David

2005-04-01

A paired-watershed budget study was used to quantify the annual water and major ion (sodium, potassium, magnesium, calcium, chloride, and sulfate) budgets of two adjacent lowland rain forest watersheds in Costa Rica. Interbasin groundwater flow (IGF) accounted for about two thirds of the water input and about 97% of the solute input (an average over the six major ions) to one watershed but little or none of the inputs to the adjacent watershed in which IGF was at most marginally distinguishable from zero. Results underscore the significance of IGF as a potential control on the hydrology and water quality of lowland watersheds, the spatial complexity of its occurrence in lowlands (where its influence may range from dominating to negligible on adjacent watersheds), and the importance of accounting for IGF in the design and execution of watershed studies and in water management.

Optimal implementation of green infrastructure practices to minimize influences of land use change and climate change on hydrology and water quality: Case study in Spy Run Creek watershed, Indiana.

PubMed

Liu, Yaoze; Engel, Bernard A; Collingsworth, Paris D; Pijanowski, Bryan C

2017-12-01

Nutrient loading from the Maumee River watershed is a significant reason for the harmful algal blooms (HABs) problem in Lake Erie. The nutrient loading from urban areas needs to be reduced with the installation of green infrastructure (GI) practices. The Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model was used to explore the influences of land use (LU) and climate change on water quantity and quality in Spy Run Creek watershed (SRCW) (part of Maumee River watershed), decide whether and where excess phosphorus loading existed, identify critical areas to understand where the greatest amount of runoff/pollutants originated, and optimally implement GI practices to obtain maximum environmental benefits with the lowest costs. Both LU/climate changes increased runoff/pollutants generated from the watershed. Areas with the highest runoff/pollutant amount per area, or critical areas, differed for various environmental concerns, land uses (LUs), and climates. Compared to optimization considering all areas, optimization conducted only in critical areas can provide similar cost-effective results with decreased computational time for low levels of runoff/pollutant reductions, but critical area optimization results were not as cost-effective for higher levels of runoff/pollutant reductions. Runoff/pollutants for 2011/2050 LUs/climates could be reduced to amounts of 2001 LU/climate by installation of GI practices with annual expenditures of $0.34 to $2.05 million. The optimization scenarios that were able to obtain the 2001 runoff level in 2011/2050, can also reduce all pollutants to 2001 levels in this watershed. Copyright © 2017 Elsevier B.V. All rights reserved.

Predicting Fecal Indicator Bacteria Fate and Removal in Urban Stormwater at the Watershed Scale

NASA Astrophysics Data System (ADS)

Wolfand, J.; Hogue, T. S.; Luthy, R. G.

2016-12-01

Urban stormwater is a major cause of water quality impairment, resulting in surface waters that fail to meet water quality standards and support their designated uses. Of the many stormwater pollutants, fecal indicator bacteria are particularly important to track because they are directly linked to pathogens which jeopardize public health; yet, their fate and transport in urban stormwater is poorly understood. Monitoring fecal bacteria in stormwater is possible, but due to the high variability of fecal indicators both spatially and temporally, single grab or composite samples do not fully capture fecal indicator loading. Models have been developed to predict fecal indicator bacteria at the watershed scale, but they are often limited to agricultural areas, or areas that receive frequent rainfall. Further, it is unclear whether best management practices (BMPs), such as bioretention or engineered wetlands, are able to reduce bacteria to meet water quality standards at watershed outlets. This research seeks to develop a model to predict fecal indicator bacteria in urban stormwater in a semi-arid climate at the watershed scale. Using the highly developed Ballona Creek watershed (89 mi2) located in Los Angeles County as a case study, several existing mechanistic models are coupled with a hydrologic model to predict fecal indicator concentrations (E. coli, enterococci, fecal coliform, and total coliform) at the outfall of Ballona Creek watershed, Santa Monica Bay. The hydrologic model was developed using InfoSWMM Sustain, calibrated for flow from WY 1998-2006 (NSE = 0.94; R2 = 0.95), and validated from WY 2007-2015 (NSE = 0.93; R2 = 0.95). The developed coupled model is being used to predict fecal indicator fate and transport and evaluate how BMPs can be optimized to reduce fecal indicator loading to surface waters and recreational beaches.

Habitat Restoration and Monitoring in Urban Streams: The Case of Tryon Creek in Portland, OR

NASA Astrophysics Data System (ADS)

Rios Touma, B. P.; Prescott, C.; Axtell, S.; Kondolf, G. M.

2013-12-01

Habitat enhancement in urban streams can be important for threatened species but challenging, because of altered catchment hydrology and urban encroachment on floodplains and channel banks. In Portland (OR) restoration actions have been undertaken at the watershed scale (e.g.: storm water management, protection of sites with high watershed value) to improve water quality, and at reach scale, when water quality and quantity are adequate, to increase habitat heterogeneity and stabilize banks. To evaluate reach-scale restoration projects in the Tryon Creek watershed, we sampled benthic macroinvertebrates and conducted habitat quality surveys pre-project and over 4 years post- project. Species sensitive to pollution and diversity of trophic groups increased after restoration. Although taxonomical diversity increased after restoration, but was still low compared to reference streams. We found no significant changes in trait proportions and functional diversity. Functional diversity, proportion of shredders and semivoltine invertebrates were significantly higher in reference streams than the restored stream reaches. We hypothesized that inputs of coarse particulate organic matter and land use at watershed scale may explain the differences in biodiversity between restored and reference stream reaches. Variables such as substrate composition, canopy cover or large wood pieces did not change from pre- to post-project, so could not explain the changes in the community. This may have been partly attributable to insensitivity of the visual estimate methods used, but likely also reflects an importance influence of watershed variables on aquatic biota - suggesting watershed actions may be more effective for the ecological recovery of streams. For future projects, we recommend multihabitat benthic sampling supported by studies of channel geomorphology to better understand stream response to restoration actions.

Geospatial tool-based morphometric analysis using SRTM data in Sarabanga Watershed, Cauvery River, Salem district, Tamil Nadu, India

NASA Astrophysics Data System (ADS)

Arulbalaji, P.; Gurugnanam, B.

2017-11-01

A morphometric analysis of Sarabanga watershed in Salem district has been chosen for the present study. Geospatial tools, such as remote sensing and GIS, are utilized for the extraction of river basin and its drainage networks. The Shuttle Radar Topographic Mission (SRTM-30 m resolution) data have been used for morphometric analysis and evaluating various morphometric parameters. The morphometric parameters of Sarabanga watershed have been analyzed and evaluated by pioneer methods, such as Horton and Strahler. The dendritic type of drainage pattern is draining the Sarabanga watershed, which indicates that lithology and gentle slope category is controlling the study area. The Sarabanga watershed is covered an area of 1208 km2. The slope of the watershed is various from 10 to 40% and which is controlled by lithology of the watershed. The bifurcation ratio ranges from 3 to 4.66 indicating the influence of geological structure and suffered more structural disturbances. The form factor indicates elongated shape of the study area. The total stream length and area of watershed indicate that mean annual rainfall runoff is relatively moderate. The basin relief expressed that watershed has relatively high denudation rates. The drainage density of the watershed is low indicating that infiltration is more dominant. The ruggedness number shows the peak discharges that are likely to be relatively higher. The present study is very useful to plan the watershed management.

[Evolution pattern of impervious surface in the Yuqiao Reservoir Watershed, Tianjin, China during the process of urbanization.

PubMed

Xie, Hui Jun; Li, Chong Wei; Zhang, Ya Juan; Song, Ai Yun

2016-04-22

Imperviousness in watershed is a key index to measure urbanization status which exerts an important impact on both eco-hydrological process and spatio-temporal pattern. Taking Yuqiao Reservoir Watershed as a case study area, based on the ENVI 5.1 software, the basic impervious surface information was extracted from remote sensing images taken in 1984, 1994, 2004 and 2013. The linear spectral mixture analysis (LSMA) model was applied to extract the impervious surface area (ISA) in nine coverage classes of watershed in order to analyze its spatio-temporal varying trend in terms of the landscape pattern metrics. Results showed that the RMSE and IS pixel accuracy of all samples were 0.005 and 85.4% respectively, which indicated that the method of extracting impervious surface on a basin scale was feasible. The average of ISA showed a linear growth, from 0.16 to 0.23, the impervious surface area increased by 4.9% in the whole watershed, and the total impervious surface area increased by 1 time. In the sub-basin road network, the impervious surface area increased gradually with the density of the road network, and its expansion pattern was of infilling growth. The patch shape of the middle coverage degree was irregular, and its fragmentation degree was the highest. The fragmentation degree and diversity of the landscape in the whole river basin increased year by year due to increasing human disturbance.

Regional prioritisation of flood risk in mountainous areas

NASA Astrophysics Data System (ADS)

Rogelis, M. C.; Werner, M.; Obregón, N.; Wright, G.

2015-07-01

A regional analysis of flood risk was carried out in the mountainous area surrounding the city of Bogotá (Colombia). Vulnerability at regional level was assessed on the basis of a principal component analysis carried out with variables recognised in literature to contribute to vulnerability; using watersheds as the unit of analysis. The area exposed was obtained from a simplified flood analysis at regional level to provide a mask where vulnerability variables were extracted. The vulnerability indicator obtained from the principal component analysis was combined with an existing susceptibility indicator, thus providing an index that allows the watersheds to be prioritised in support of flood risk management at regional level. Results show that the components of vulnerability can be expressed in terms of four constituent indicators; socio-economic fragility, which is composed of demography and lack of well-being; lack of resilience, which is composed of education, preparedness and response capacity, rescue capacity, social cohesion and participation; and physical exposure is composed of exposed infrastructure and exposed population. A sensitivity analysis shows that the classification of vulnerability is robust for watersheds with low and high values of the vulnerability indicator, while some watersheds with intermediate values of the indicator are sensitive to shifting between medium and high vulnerability. The complex interaction between vulnerability and hazard is evidenced in the case study. Environmental degradation in vulnerable watersheds shows the influence that vulnerability exerts on hazard and vice versa, thus establishing a cycle that builds up risk conditions.

Spatio-Temporal Process Variability in Watershed Scale Wetland Restoration Planning

NASA Astrophysics Data System (ADS)

Evenson, G. R.

2012-12-01

Watershed scale restoration decision making processes are increasingly informed by quantitative methodologies providing site-specific restoration recommendations - sometimes referred to as "systematic planning." The more advanced of these methodologies are characterized by a coupling of search algorithms and ecological models to discover restoration plans that optimize environmental outcomes. Yet while these methods have exhibited clear utility as decision support toolsets, they may be critiqued for flawed evaluations of spatio-temporally variable processes fundamental to watershed scale restoration. Hydrologic and non-hydrologic mediated process connectivity along with post-restoration habitat dynamics, for example, are commonly ignored yet known to appreciably affect restoration outcomes. This talk will present a methodology to evaluate such spatio-temporally complex processes in the production of watershed scale wetland restoration plans. Using the Tuscarawas Watershed in Eastern Ohio as a case study, a genetic algorithm will be coupled with the Soil and Water Assessment Tool (SWAT) to reveal optimal wetland restoration plans as measured by their capacity to maximize nutrient reductions. Then, a so-called "graphical" representation of the optimization problem will be implemented in-parallel to promote hydrologic and non-hydrologic mediated connectivity amongst existing wetlands and sites selected for restoration. Further, various search algorithm mechanisms will be discussed as a means of accounting for temporal complexities such as post-restoration habitat dynamics. Finally, generalized patterns of restoration plan optimality will be discussed as an alternative and possibly superior decision support toolset given the complexity and stochastic nature of spatio-temporal process variability.

Random forests as cumulative effects models: A case study of lakes and rivers in Muskoka, Canada.

PubMed

Jones, F Chris; Plewes, Rachel; Murison, Lorna; MacDougall, Mark J; Sinclair, Sarah; Davies, Christie; Bailey, John L; Richardson, Murray; Gunn, John

2017-10-01

Cumulative effects assessment (CEA) - a type of environmental appraisal - lacks effective methods for modeling cumulative effects, evaluating indicators of ecosystem condition, and exploring the likely outcomes of development scenarios. Random forests are an extension of classification and regression trees, which model response variables by recursive partitioning. Random forests were used to model a series of candidate ecological indicators that described lakes and rivers from a case study watershed (The Muskoka River Watershed, Canada). Suitability of the candidate indicators for use in cumulative effects assessment and watershed monitoring was assessed according to how well they could be predicted from natural habitat features and how sensitive they were to human land-use. The best models explained 75% of the variation in a multivariate descriptor of lake benthic-macroinvertebrate community structure, and 76% of the variation in the conductivity of river water. Similar results were obtained by cross-validation. Several candidate indicators detected a simulated doubling of urban land-use in their catchments, and a few were able to detect a simulated doubling of agricultural land-use. The paper demonstrates that random forests can be used to describe the combined and singular effects of multiple stressors and natural environmental factors, and furthermore, that random forests can be used to evaluate the performance of monitoring indicators. The numerical methods presented are applicable to any ecosystem and indicator type, and therefore represent a step forward for CEA. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Distributed modeling of radiocesium washoff from the experimental watershed plots of the Fukushima fallout zone

NASA Astrophysics Data System (ADS)

Kivva, Sergei; Zheleznyak, Mark; Konoplev, Alexei; Nanba, Kenji; Onda, Yuichi; Wakiyama Yoshifumi Wakiyama, Yoshifumi

2015-04-01

The distributed hydrological "rainfall- runoff" models provide possibilities of the physically based simulation of surface and subsurface flow on watersheds based on the GIS processed data. The success of such modeling approaches for the predictions of the runoff and soil erosion provides a basis for the implementation of the distributed models of the radionuclide washoff from the watersheds. The field studies provided on the Chernobyl and Fukushima catchments provides a unique data sets for the comparative testing and improvements of the modeling tools for the watersheds located in the areas of the very different geographical and hydro-meteorological condition The set of USLE experimental plots has been established by CRIED, University of Tsukuba after the Fukushima accident to study soil erosion and 137Cs wash off from the watersheds (Onda et al, 2014). The distributed watershed models of surface and subsurface flow, sediment and radionuclide transport has been used to simulate the radionuclide transport in the basin Dnieper River, Ukraine and the watersheds of Prefecture Fuksuhima. DHSVM-R is extension of the distributed hydrological model DHSVM (Lettenmayer, Wigmosta et al, 1996-2014) by the including into it the module of the watershed radionuclide transport. DHSVM is a physically based, distributed hydrology-vegetation model for complex terrain based on the numerical solution of the network of one-dimensional equations. The surface flow submodel of DHSMV has been modified: four-directions schematization for the model's cells has been replaced by the eight-directions scheme, more numerically efficient finite -differences scheme was implemented. The new module of radionuclide wash-off from catchment and transport via stream network in soluble phase and on suspended sediments including bottom-water exchange processes was developed for DHSMV-R. DHSVM-R was implemented recently within Swedish- Ukrainian ENSURE project for the modeling of 234U wash-off from the watershed of Konoplyanka river, tributary of Dnieper Rivet at the territory of the Pridneprovsky Chemical) Plant and neighboring tailings dumps. The modeling results has been used for the assessment of the watershed's "hot spots" and analyses of the ways of the diminishing of the uranium wash off from the watersheds The testing of DHSMV-R has started in 2014 for Fukushima watershed experimental plots. The major amount of 137Cs is washed out from watershed on sediments and only small fraction in solute. The reason for such phenomenon that was not observed at Chernobyl can be - steeper slopes, more intensive rains ( daily maximum in Fukushima city at 160 mm, hourly maximum 69mm) and higher Kd values due to the volcanic kind of soils. The virtual rain of the daily amount 200 mm ( as in mountains around Fukushima city) was applied for Farmland A1- slope 7.36% and imaginary watershed (case B) the same as A1 however slope as in Chernobyl plots ( Konoplev, 1996) 4%. Due to the high nonlinearity in erosion equations for the such heavy precipitations the total amount of washed out 137Cs with sediments for the steep watershed A due to the simulated rainstorm ( 11530 Bq) is at 20 times higher, than such amount for mild slope watershed B ( 690 Bq) when the watershed A is only twice steeper than B. The modeling results demonstrate that the higher intensity of the extreme rainstorm in Fukushima area than in Chernobyl area initiated even on slightly steeper slopes the much higher amount of 137Cs washed out with sediments in Fukushima than in Chernobyl area. The successful testing of the distributed model provides the background for the simulation of the watersheds of the larger scales for small, medium and large rivers. The implementation of such models is important as for the forecasting of 137Cs wash out from the watersheds and following transport in rivers for the highest extreme floods that still did not happen in Fukushima area after the accident, as also for the long term forecasting of 137Cs in watershed-river systems at Fukushima.

Impacts of Climate and Land-cover Changes on Water Resources in a Humid Subtropical Watershed: a Case Study from East Texas, USA

NASA Astrophysics Data System (ADS)

Heo, J.

2015-12-01

This study investigates an interconnected system of climate change - land cover - water resources for a watershed in humid subtropical climate from 1970 to 2009. A 0.7°C increase in temperature and a 16.3% increase in precipitation were observed in our study area where temperature had no obvious increase trend and precipitation showed definite increasing trend compared to previous studies. The main trend of land-cover change was conversion of vegetation and barren lands to developed and crop lands affected by human intervention, and forest and grass to bush/shrub which considered to be caused by natural climate system. Precipitation contribution to the other hydrologic parameters for a humid subtropical basin is estimated to be 51.9% of evapotranspiration, 16.3% of surface runoff, 0.9% of groundwater discharge, 19.3% of soil water content, and 11.6% of water storage. It shows little higher evapotranspiration and considerably lower surface runoff compare to other humid climate area due to vegetation dominance of land cover. Hydrologic responses to climate and land cover changes are increases of surface runoff, soil water content, evapotranspiration by 15.0%, 2.7%, and 20.1%, respectively, and decrease of groundwater discharge decreased by 9.2%. Surface runoff is relatively stable with precipitation while groundwater discharge and soil water content are sensitive to land cover changes especially human intervention. If temperature is relatively stable, it is considered to be land cover plays important role in evapotranspiration. Citation: Heo, J., J. Yu, J. R. Giardino, and H. Cho (2015), Impacts of climate and land-cover changes on water resources in a humid subtropical watershed: a case study from East Texas, USA, Water Environ. J., 29, doi:10.1111/wej.12096

Evaluating Coupled Human-Hydrologic Systems in High Altitude Regions: A Case Study of the Arun Watershed, Eastern Nepal

NASA Astrophysics Data System (ADS)

Voss, K.; Bookhagen, B.; Tague, C.; Lopez-Carr, D.

2014-12-01

The Himalaya exhibit dynamic ecological, hydrological, and climatic extremes that magnify the variability and extent of natural hazards, resulting in destruction to both physical and human landscapes. Coupled with poverty, these factors intensify local communities' vulnerability to climate change. This study highlights the Arun watershed in eastern Nepal as a case study to evaluate how local communities in high altitude regions are managing their water for domestic and agricultural needs while coping with extreme events, such as floods and landslides. Remotely-sensed precipitation, snowpack and glacial extent data from the past decade are combined with preliminary results from extensive field-based community surveys in the Arun watershed. The analysis of remotely-sensed data will describe seasonal trends in water availability, glacial lake growth, and the spatial variation of these trends within the basin. These hydrologic changes will be linked to the human survey analysis, which will provide an understanding of locals' perceptions of water challenges and the current water management strategies within the basin. Particular attention will be given to a comparison between the eastern and western tributaries of the Arun River, where the catchments are mainly rain-fed (eastern) versus glacial-fed (western). This contrast will highlight how different hydrologic scenarios evidenced from remote-sensing data motivate diverse human water management responses as defined in field surveys. A particular focus will be given to management decisions related to agriculture expansion and hydropower development. This synthesis of remote-sensing and social research methodologies provides a valuable perspective on coupled human-hydrologic systems.

Analysis of Artificial Neural Network in Erosion Modeling: A Case Study of Serang Watershed

NASA Astrophysics Data System (ADS)

Arif, N.; Danoedoro, P.; Hartono

2017-12-01

Erosion modeling is an important measuring tool for both land users and decision makers to evaluate land cultivation and thus it is necessary to have a model to represent the actual reality. Erosion models are a complex model because of uncertainty data with different sources and processing procedures. Artificial neural networks can be relied on for complex and non-linear data processing such as erosion data. The main difficulty in artificial neural network training is the determination of the value of each network input parameters, i.e. hidden layer, momentum, learning rate, momentum, and RMS. This study tested the capability of artificial neural network application in the prediction of erosion risk with some input parameters through multiple simulations to get good classification results. The model was implemented in Serang Watershed, Kulonprogo, Yogyakarta which is one of the critical potential watersheds in Indonesia. The simulation results showed the number of iterations that gave a significant effect on the accuracy compared to other parameters. A small number of iterations can produce good accuracy if the combination of other parameters was right. In this case, one hidden layer was sufficient to produce good accuracy. The highest training accuracy achieved in this study was 99.32%, occurred in ANN 14 simulation with combination of network input parameters of 1 HL; LR 0.01; M 0.5; RMS 0.0001, and the number of iterations of 15000. The ANN training accuracy was not influenced by the number of channels, namely input dataset (erosion factors) as well as data dimensions, rather it was determined by changes in network parameters.

The influence of changes in land use and landscape patterns on soil erosion in a watershed.

PubMed

Zhang, Shanghong; Fan, Weiwei; Li, Yueqiang; Yi, Yujun

2017-01-01

It is very important to have a good understanding of the relation between soil erosion and landscape patterns so that soil and water conservation in river basins can be optimized. In this study, this relationship was explored, using the Liusha River Watershed, China, as a case study. A distributed water and sediment model based on the Soil and Water Assessment Tool (SWAT) was developed to simulate soil erosion from different land use types in each sub-basin of the Liusha River Watershed. Observed runoff and sediment data from 1985 to 2005 and land use maps from 1986, 1995, and 2000 were used to calibrate and validate the model. The erosion modulus for each sub-basin was calculated from SWAT model results using the different land use maps and 12 landscape indices were chosen and calculated to describe the land use in each sub-basin for the different years. The variations in instead of the absolute amounts of the erosion modulus and the landscape indices for each sub-basin were used as the dependent and independent variables, respectively, for the regression equations derived from multiple linear regression. The results indicated that the variations in the erosion modulus were closely related to changes in the large patch index, patch cohesion index, modified Simpson's evenness index, and the aggregation index. From the regression equation and the corresponding landscape indices, it was found that watershed erosion can be reduced by decreasing the physical connectivity between patches, improving the evenness of the landscape patch types, enriching landscape types, and enhancing the degree of aggregation between the landscape patches. These findings will be useful for water and soil conservation and for optimizing the management of watershed landscapes. Copyright © 2016 Elsevier B.V. All rights reserved.

An integrated system dynamics model developed for managing lake water quality at the watershed scale.

PubMed

Liu, Hui; Benoit, Gaboury; Liu, Tao; Liu, Yong; Guo, Huaicheng

2015-05-15

A reliable system simulation to relate socioeconomic development with water environment and to comprehensively represent a watershed's dynamic features is important. In this study, after identifying lake watershed system processes, we developed a system dynamics modeling framework for managing lake water quality at the watershed scale. Two reinforcing loops (Development and Investment Promotion) and three balancing loops (Pollution, Resource Consumption, and Pollution Control) were constituted. Based on this work, we constructed Stock and Flow Diagrams that embedded a pollutant load model and a lake water quality model into a socioeconomic system dynamics model. The Dianchi Lake in Yunnan Province, China, which is the sixth largest and among the most severely polluted freshwater lakes in China, was employed as a case study to demonstrate the applicability of the model. Water quality parameters considered in the model included chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP). The business-as-usual (BAU) scenario and three alternative management scenarios on spatial adjustment of industries and population (S1), wastewater treatment capacity construction (S2), and structural adjustment of agriculture (S3), were simulated to assess the effectiveness of certain policies in improving water quality. Results showed that S2 is most effective scenario, and the COD, TN, and TP concentrations in Caohai in 2030 are 52.5, 10.9, and 0.8 mg/L, while those in Waihai are 9.6, 1.2, and 0.08 mg/L, with sustained development in the watershed. Thus, the model can help support the decision making required in development and environmental protection strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analyzing the variability of sediment yield: A case study from paired watersheds in the Upper Blue Nile basin, Ethiopia

NASA Astrophysics Data System (ADS)

Ebabu, Kindiye; Tsunekawa, Atsushi; Haregeweyn, Nigussie; Adgo, Enyew; Meshesha, Derege Tsegaye; Aklog, Dagnachew; Masunaga, Tsugiyuki; Tsubo, Mitsuru; Sultan, Dagnenet; Fenta, Ayele Almaw; Yibeltal, Mesenbet

2018-02-01

Improved knowledge of watershed-scale spatial and temporal variability of sediment yields (SY) is needed to design erosion control strategies, particularly in the most severely eroded areas. The present study was conducted to provide this knowledge for the humid tropical highlands of Ethiopia using the Akusity and Kasiry paired watersheds in the Guder portion of the Upper Blue Nile basin. Discharge and suspended sediment concentration data were monitored during the rainy season of 2014 and 2015 using automatic flow stage sensors, manual staff gauges and a depth-integrated sediment sampler. The SY was calculated using empirical discharge-sediment curves for different parts of each rainy season. The measured mean daily sediment concentration differed greatly between years and watersheds (0.51 g L- 1 in 2014 and 0.92 g L- 1 in 2015 for Kasiry, and 1.04 g L- 1 in 2014 and 2.20 g L- 1 in 2015 for Akusity). Sediment concentrations at both sites decreased as the rainy season progressed, regardless of the rainfall pattern, owing to depletion of the sediment supply and limited transport capacity of the flows caused by increased vegetation cover. Rainy season SYs for Kasiry were 7.6 t ha- 1 in 2014 and 27.2 t ha- 1 in 2015, while in Akusity SYs were 25.7 t ha- 1 in 2014 and 71.2 t ha- 1 in 2015. The much larger values in 2015 can be partly explained by increased rainfall and larger peak flow events. The magnitude and timing of peak flow events are major determinants of the amount and variability of SYs. Thus, site-specific assessment of such events is crucial to reveal SY dynamics of small watersheds in tropical highland environments.

Rural watershed partnerships: lessons from West Virginia

Treesearch

Steve W. Selin; Alan Collins; Susan Hunter

1998-01-01

The goal of this study is to examine the efforts by one state government (West Virginia) to facilitate collaborative, watershed-based planning. This paper provides an overview of the state watershed planning process and includes a summary of a baseline study of rural watershed partnerships operating within West Virginia. Implication of the study for state policies and...

Valuing Non-market Benefits of Rehabilitation of Hydrologic Cycle Improvements in the Anyangcheon Watershed: Using Mixed Logit Models

NASA Astrophysics Data System (ADS)

Yoo, J.; Kong, K.

2010-12-01

This research the findings from a discrete-choice experiment designed to estimate the economic benefits associated with the Anyangcheon watershed improvements in Rep. of Korea. The Anyangcheon watershed has suffered from streamflow depletion and poor stream quality, which often negatively affect instream and near-stream ecologic integrity, as well as water supply. Such distortions in the hydrologic cycle mainly result from rapid increase of impermeable area due to urbanization, decreases of baseflow runoff due to groundwater pumping, and reduced precipitation inputs driven by climate forcing. As well, combined sewer overflows and increase of non-point source pollution from urban regions decrease water quality. The appeal of choice experiments (CE) in economic analysis is that it is based on random utility theory (McFadden, 1974; Ben-Akiva and Lerman, 1985). In contrast to contingent valuation method (CVM), which asks people to choose between a base case and a specific alternative, CE asks people to choice between cases that are described by attributes. The attributes of this study were selected from hydrologic vulnerability components that represent flood damage possibility, instreamflow depletion, water quality deterioration, form of the watershed and tax. Their levels were divided into three grades include status quo. Two grades represented the ideal conditions. These scenarios were constructed from a 35 orthogonal main effect design. This design resulted in twenty-seven choice sets. The design had nine different choice scenarios presented to each respondent. The most popular choice models in use are the conditional logit (CNL). This model provides closed-form choice probability calculation. The shortcoming of CNL comes from irrelevant alternatives (IIA). In this paper, the mixed logit (ML) is applied to allow the coefficient’s variation for random taste heterogeneity in the population. The mixed logit model(with normal distributions for the attributes) fit the data best, indication that allowing for both heterogeneous preferences across households and correlation between repeated choices may represent actual choice behaviors best of all the estimated models. The annual benefits to improve of the Anyancheon watershed for 1% improvement of each attribute was 406.7 billion Won(0.34 billion USD). This study is expected to contribute to the decision-making process for policy-makers by providing useful methodological framework and quantitative information related to watershed improvement projects.Table 1. Estimated Results of Conditional Logit and Mixed Logit Model 1) t-values are shown in brackets

Predicting nitrogen loading with land-cover composition: how can watershed size affect model performance?

PubMed

Zhang, Tao; Yang, Xiaojun

2013-01-01

Watershed-wide land-cover proportions can be used to predict the in-stream non-point source pollutant loadings through regression modeling. However, the model performance can vary greatly across different study sites and among various watersheds. Existing literature has shown that this type of regression modeling tends to perform better for large watersheds than for small ones, and that such a performance variation has been largely linked with different interwatershed landscape heterogeneity levels. The purpose of this study is to further examine the previously mentioned empirical observation based on a set of watersheds in the northern part of Georgia (USA) to explore the underlying causes of the variation in model performance. Through the combined use of the neutral landscape modeling approach and a spatially explicit nutrient loading model, we tested whether the regression model performance variation over the watershed groups ranging in size is due to the different watershed landscape heterogeneity levels. We adopted three neutral landscape modeling criteria that were tied with different similarity levels in watershed landscape properties and used the nutrient loading model to estimate the nitrogen loads for these neutral watersheds. Then we compared the regression model performance for the real and neutral landscape scenarios, respectively. We found that watershed size can affect the regression model performance both directly and indirectly. Along with the indirect effect through interwatershed heterogeneity, watershed size can directly affect the model performance over the watersheds varying in size. We also found that the regression model performance can be more significantly affected by other physiographic properties shaping nitrogen delivery effectiveness than the watershed land-cover heterogeneity. This study contrasts with many existing studies because it goes beyond hypothesis formulation based on empirical observations and into hypothesis testing to explore the fundamental mechanism.

Hydrological similarity approach and rainfall satellite utilization for mini hydro power dam basic design (case study on the ungauged catchment at West Borneo, Indonesia)

NASA Astrophysics Data System (ADS)

Prakoso, W. G.; Murtilaksono, K.; Tarigan, S. D.; Purwanto, Y. J.

2018-05-01

An approach on flow duration and flood design estimation on the ungauged catchment with no rainfall and discharge data availability was been being develop with hydrological modelling including rainfall run off model implemented with watershed characteristic dataset. Near real time Rainfall data from multi satellite platform e.g. TRMM can be utilized for regionalization approach on the ungauged catchment. Watershed hydrologically similarity analysis were conducted including all of the major watershed in Borneo which was predicted to be similar with the Nanga Raun Watershed. It was found that a satisfactory hydrological model calibration could be achieved using catchment weighted time series of TRMM daily rainfall data, performed on nearby catchment deemed to be sufficiently similar to Nanga Raun catchment in hydrological terms. Based on this calibration, rainfall runoff parameters were then transferred to a model. Relatively reliable flow duration curve and extreme discharge value estimation were produced with reasonable several limitation. Further approach may be performed in order to deal with the primary limitations inherent in the hydrological and statistical analysis, especially to give prolongation to the availability of the rainfall and climate data with some novel approach like downscaling of global climate model.

Integrating wetland connectivity into models for watershed ...

EPA Pesticide Factsheets

Geographically isolated wetlands (GIW), or wetlands embedded in uplands, exist along a spatial and temporal hydrologic connectivity continuum to downstream waters. Via these connections and disconnections, GIWs provide numerous hydrological, biogeochemical, and biological functions linked to human health and watershed-scale ecosystem services. Often, a clear demonstration of these functions and the individual and cumulative effects of GIWs on downstream waters is required for their protection or restoration. Measurements alone are typically too resource intensive to do this. In this presentation, we discuss the use of various modeling approaches to quantify the hydrologic connectivity of GIWs and their associated watershed-scale cumulative effects. Our goal is to improve the science behind understanding the functions and connectivity of GIWs via models that are complemented with various types of novel data. We synthesize what is meant by GIW connectivity and its broad significance to science and decision-making. We further discuss case studies that provide insights to diverse modeling approaches, with varying levels of complexity, for how to estimate GIW connectivity and associated watershed-scale impacts to hydrology. We finally provide insights to the key opportunities and priorities for integrating GIW connectivity into the next generation of models. Geographically isolated wetlands (GIW), or wetlands embedded in uplands, exist along a spatial and temporal h

Methodology and application of combined watershed and ground-water models in Kansas

USGS Publications Warehouse

Sophocleous, M.; Perkins, S.P.

2000-01-01

Increased irrigation in Kansas and other regions during the last several decades has caused serious water depletion, making the development of comprehensive strategies and tools to resolve such problems increasingly important. This paper makes the case for an intermediate complexity, quasi-distributed, comprehensive, large-watershed model, which falls between the fully distributed, physically based hydrological modeling system of the type of the SHE model and the lumped, conceptual rainfall-runoff modeling system of the type of the Stanford watershed model. This is achieved by integrating the quasi-distributed watershed model SWAT with the fully-distributed ground-water model MODFLOW. The advantage of this approach is the appreciably smaller input data requirements and the use of readily available data (compared to the fully distributed, physically based models), the statistical handling of watershed heterogeneities by employing the hydrologic-response-unit concept, and the significantly increased flexibility in handling stream-aquifer interactions, distributed well withdrawals, and multiple land uses. The mechanics of integrating the component watershed and ground-water models are outlined, and three real-world management applications of the integrated model from Kansas are briefly presented. Three different aspects of the integrated model are emphasized: (1) management applications of a Decision Support System for the integrated model (Rattlesnake Creek subbasin); (2) alternative conceptual models of spatial heterogeneity related to the presence or absence of an underlying aquifer with shallow or deep water table (Lower Republican River basin); and (3) the general nature of the integrated model linkage by employing a watershed simulator other than SWAT (Wet Walnut Creek basin). These applications demonstrate the practicality and versatility of this relatively simple and conceptually clear approach, making public acceptance of the integrated watershed modeling system much easier. This approach also enhances model calibration and thus the reliability of model results. (C) 2000 Elsevier Science B.V.Increased irrigation in Kansas and other regions during the last several decades has caused serious water depletion, making the development of comprehensive strategies and tools to resolve such problems increasingly important. This paper makes the case for an intermediate complexity, quasi-distributed, comprehensive, large-watershed model, which falls between the fully distributed, physically based hydrological modeling system of the type of the SHE model and the lumped, conceptual rainfall-runoff modeling system of the type of the Stanford watershed model. This is achieved by integrating the quasi-distributed watershed model SWAT with the fully-distributed ground-water model MODFLOW. The advantage of this approach is the appreciably smaller input data requirements and the use of readily available data (compared to the fully distributed, physically based models), the statistical handling of watershed heterogeneities by employing the hydrologic-response-unit concept, and the significantly increased flexibility in handling stream-aquifer interactions, distributed well withdrawals, and multiple land uses. The mechanics of integrating the component watershed and ground-water models are outlined, and three real-world management applications of the integrated model from Kansas are briefly presented. Three different aspects of the integrated model are emphasized: (1) management applications of a Decision Support System for the integrated model (Rattlesnake Creek subbasin); (2) alternative conceptual models of spatial heterogeneity related to the presence or absence of an underlying aquifer with shallow or deep water table (Lower Republican River basin); and (3) the general nature of the integrated model linkage by employing a watershed simulator other than SWAT (Wet Walnut Creek basin). These applications demonstrate the practicality and ve

Escape from the Delta: Preparation and Evacuation for Catastrophic Flooding in California Emergency Management Agency Region 4

DTIC Science & Technology

2011-03-29

Baldwin, R. (2010). Conversation with San Joaquin County OES. (Personal communication 09 November 2010) Bass, D . J. (2011). Delta Watershed ...4 Analysis 25 4.1 Establishing the Base Case . . . . . . . . . . . . . . . . . . . . . . 25 4.2 SCENARIO: Sacramento County...Tables 53 Initial Distribution List 63 viii List of Figures Figure 1.1 The watershed which feeds the delta drains the majority of California’s rainfall

Modelling of the estimated contributions of different sub-watersheds and sources to phosphorous export and loading from the Dongting Lake watershed, China.

PubMed

Hou, Ying; Chen, Weiping; Liao, Yuehua; Luo, Yueping

2017-11-03

Considerable growth in the economy and population of the Dongting Lake watershed in Southern China has increased phosphorus loading to the lake and resulted in a growing risk of lake eutrophication. This study aimed to reveal the spatial pattern and sources of phosphorus export and loading from the watershed. We applied an export coefficient model and the Dillon-Rigler model to quantify contributions of different sub-watersheds and sources to the total phosphorus (TP) export and loading in 2010. Together, the upper and lower reaches of the Xiang River watershed and the Dongting Lake Area contributed 60.9% of the TP exported from the entire watershed. Livestock husbandry appeared to be the largest anthropogenic source of TP, contributing more than 50% of the TP exported from each secondary sub-watersheds. The actual TP loading to the lake in 2010 was 62.9% more than the permissible annual TP loading for compliance with the Class III water quality standard for lakes. Three primary sub-watersheds-the Dongting Lake Area, the Xiang River, and the Yuan River watersheds-contributed 91.2% of the total TP loading. As the largest contributor among all sources, livestock husbandry contributed nearly 50% of the TP loading from the Dongting Lake Area and more than 60% from each of the other primary sub-watersheds. This study provides a methodology to identify the key sources and locations of TP export and loading in large lake watersheds. The study can provide a reference for the decision-making for controlling P pollution in the Dongting Lake watershed.

National Audubon Society v. Superior Court: a watershed case integrating the public trust doctrine and California water law

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

Gaylord, R.K.

Audobon v. Superior Court is a ''watershed'' case in its integration of the public trust doctrine within traditional water law. The public trust doctrine requires the state to exercise a duty of continued supervision over the taking and use of appropriated water. As a result, the state must periodically balance the economic interests served by the water appropriations with the ecological and recreational interests protected under the public trust. The state can best meet this burden by adopting a balancing procedure that includes comprehensive, long-term planning of the economic effects and ecological interests in water appropriation. 78 references.

Impacts of correcting the inter-variable correlation of climate model outputs on hydrological modeling

NASA Astrophysics Data System (ADS)

Chen, Jie; Li, Chao; Brissette, François P.; Chen, Hua; Wang, Mingna; Essou, Gilles R. C.

2018-05-01

Bias correction is usually implemented prior to using climate model outputs for impact studies. However, bias correction methods that are commonly used treat climate variables independently and often ignore inter-variable dependencies. The effects of ignoring such dependencies on impact studies need to be investigated. This study aims to assess the impacts of correcting the inter-variable correlation of climate model outputs on hydrological modeling. To this end, a joint bias correction (JBC) method which corrects the joint distribution of two variables as a whole is compared with an independent bias correction (IBC) method; this is considered in terms of correcting simulations of precipitation and temperature from 26 climate models for hydrological modeling over 12 watersheds located in various climate regimes. The results show that the simulated precipitation and temperature are considerably biased not only in the individual distributions, but also in their correlations, which in turn result in biased hydrological simulations. In addition to reducing the biases of the individual characteristics of precipitation and temperature, the JBC method can also reduce the bias in precipitation-temperature (P-T) correlations. In terms of hydrological modeling, the JBC method performs significantly better than the IBC method for 11 out of the 12 watersheds over the calibration period. For the validation period, the advantages of the JBC method are greatly reduced as the performance becomes dependent on the watershed, GCM and hydrological metric considered. For arid/tropical and snowfall-rainfall-mixed watersheds, JBC performs better than IBC. For snowfall- or rainfall-dominated watersheds, however, the two methods behave similarly, with IBC performing somewhat better than JBC. Overall, the results emphasize the advantages of correcting the P-T correlation when using climate model-simulated precipitation and temperature to assess the impact of climate change on watershed hydrology. However, a thorough validation and a comparison with other methods are recommended before using the JBC method, since it may perform worse than the IBC method for some cases due to bias nonstationarity of climate model outputs.

Validation of in situ networks via field sampling: case study in the South Fork Experimental Watershed

USDA-ARS?s Scientific Manuscript database

The calibration and validation of soil moisture remote sensing products is complicated by the logistics of installing a soil moisture network for a long term period in an active landscape. Therefore, these stations are located along field boundaries or in non-representative sites with regards to so...

Subsurface drainage volume reduction with drainage water management: Case studies in Ohio, USA

USDA-ARS?s Scientific Manuscript database

One of the main contributors to poor water quality in the Mississippi River and aeral increase in the hypoxic zone in the Gulf of Mexico is intensive drainage of the cropland within the watershed. Controlled drainage has been demonstrated as an approach to curb totla drainage outflow and nutrient di...

Predicting Plausible Impacts of Sets of Climate and Land Use Change Scenarios on Water Resources

EPA Science Inventory

Global changes in climate and land use can alTect the quantity and quality of water resources. Hence, we need a methodology to predict these ramifications. Using the Little Miami River (LMR) watershed as a case study, this paper describes a spatial analytical approach integrating...

Conservation of Yellowstone Cutthroat Trout in Yellowstone National Park: A Case Study

ERIC Educational Resources Information Center

Duncan, Michael B.; Murphy, Brian R.; Zale, Alexander V.

2009-01-01

The Yellowstone cutthroat trout (YCT; "Oncorhynchus clarki bouvieri") has become a species of special concern for Yellowstone National Park (YNP) fisheries biologists. Although this subspecies formerly occupied a greater area than any other inland cutthroat trout, the current distribution of YCT is now limited to several watersheds within the…

ASSESSING THE RELATIVE AND COMBINED IMPACTS OF FUTURE LAND-USE AND CLIMATE CHANGES ON NONPOINT SOURCE POLLUTION

EPA Science Inventory

In this paper, we discuss the potential water quality impacts of future land-use and climate changes. The Little Miami River Basin was used as a case study. It is a predominantly agricultural watershed in southwestern Ohio (U.S.A.) that has experienced land-use modifications. ...

Framework to parameterize and validate APEX to support deployment of the nutrient tracking tool

USDA-ARS?s Scientific Manuscript database

Guidelines have been developed to parameterize and validate the Agricultural Policy Environmental eXtender (APEX) to support the Nutrient Tracking Tool (NTT). This follow-up paper presents 1) a case study to illustrate how the developed guidelines are applied in a headwater watershed located in cent...

Effects of Nitrogen Enrichment, Wildfire, and Harvesting on Forest-Soil Carbon and Nitrogen

Treesearch

Jennifer L. Parker; Ivan J. Fernandez; Lindsey E. Rustad; Stephen A. Norton

2001-01-01

Northern forest soils represent large reservoirs of C and N that may be altered by ecosystem perturbations. Soils at three paired watershed in Maine were investigated as case studies of experimentally elevated N deposition, wildfire, and whole-tree harvesting. Eight years of experimental (NH4)2SO4...

Streambanks: A net source of sediment and phosphorus to streams and rivers

USDA-ARS?s Scientific Manuscript database

Sediment and phosphorus (P) are two primary pollutants of surface waters. Many studies have investigated loadings from upland sources or even streambed sediment, but in many cases, limited to no data exist to determine sediment and P loading from streambanks on a watershed scale. The objectives of t...

Delivery of Ecosystem Benefits at the Urban-Suburban Interface: A Case Study of Flood Protection in the Woonasquatucket River Watershed

EPA Science Inventory

Urbanization exacerbates flooding by increasing surface runoff and decreasing surface roughness. Restoring wetlands can enhance flood protection while providing a suite of co-benefits such as temperature regulation and access to open space. Spatial modeling of the delivery of flo...

Welfare implications of tropical forest conservation: the case of Ruteng Park

Treesearch

David Butry; Subhrendu Pattanayak

2000-01-01

In 1993, the Indonesian government established the Ruteng Nature Recreation Park in western Flores. Subsequently, the government banned all timber extraction in and around the park's sub-tropical forest to promote biodiversity and watershed protection. This study quantitatively examines the role that tropical forest conservation has on the development of the local...

The hidden consequences of fire suppression

Treesearch

Carol Miller

2012-01-01

Wilderness managers need a way to quantify and monitor the effects of suppressing lightning-caused wildfires, which can alter natural fire regimes, vegetation, and habitat. Using computerized models of fire spread, weather, and fuels, it is now possible to quantify many of the hidden consequences of fire suppression. Case study watersheds in Yosemite and Sequoia-Kings...

Rainfall Threshold for Flash Flood Early Warning Based on Rational Equation: A Case Study of Zuojiao Watershed in Yunnan Province

NASA Astrophysics Data System (ADS)

Li, Q.; Wang, Y. L.; Li, H. C.; Zhang, M.; Li, C. Z.; Chen, X.

2017-12-01

Rainfall threshold plays an important role in flash flood warning. A simple and easy method, using Rational Equation to calculate rainfall threshold, was proposed in this study. The critical rainfall equation was deduced from the Rational Equation. On the basis of the Manning equation and the results of Chinese Flash Flood Survey and Evaluation (CFFSE) Project, the critical flow was obtained, and the net rainfall was calculated. Three aspects of the rainfall losses, i.e. depression storage, vegetation interception, and soil infiltration were considered. The critical rainfall was the sum of the net rainfall and the rainfall losses. Rainfall threshold was estimated after considering the watershed soil moisture using the critical rainfall. In order to demonstrate this method, Zuojiao watershed in Yunnan Province was chosen as study area. The results showed the rainfall thresholds calculated by the Rational Equation method were approximated to the rainfall thresholds obtained from CFFSE, and were in accordance with the observed rainfall during flash flood events. Thus the calculated results are reasonable and the method is effective. This study provided a quick and convenient way to calculated rainfall threshold of flash flood warning for the grass root staffs and offered technical support for estimating rainfall threshold.

Modeling post-fire sediment yield based on two burn scenarios at the Sooke Lake Reservoir, BC, Canada

NASA Astrophysics Data System (ADS)

Dobre, Mariana; Elliot, William J.; Brooks, Erin S.; Smith, Tim

2016-04-01

Wildfires can have major adverse effects on municipal water sources. Local governments need methods to evaluate fire risk and to develop mitigation procedures. The Sooke Lake Reservoir is the primary source of water for the city of Victoria, BC and the concern is that sediment delivered from upland burned areas could have a detrimental impact on the reservoir and the water supply. We conducted a sediment delivery modeling pilot study on a portion of the Sooke Lake Reservoir (specifically, the Trestle Creek Management Unit (TCMU)) to evaluate the potential impacts of wildfire on sediment delivery from hillslopes and sub-catchments. We used a process-based hydrologic and soil erosion model called Water Erosion Prediction Project geospatial interface, GeoWEPP, to predict the sediment delivery from specific return period design storms for two burn severity scenarios: real (low-intensity burn severity) and worst (high-intensity burn severity) case scenarios. The GeoWEPP model allows users to simulate streamflow and erosion from hillslope polygons within a watershed. The model requires information on the topographic, soil and vegetative characteristics for each hillslope and a weather file. WEPP default values and several assumptions were necessary to apply the model where data were missing. Based on a 10-m DEM we delineated 16 watersheds within the TCMU area. A long term 100-year daily climate file was generated for this analysis using the CLIGEN model based on the historical observations recorded at Concrete, WA in United States, and adjusted for observed monthly precipitation observed in the Sooke Basin. We ran 100-year simulations and calculated yearly and event-based return periods (for 2, 5, 10, 20, 25, and 50 years) for each of the 16 watersheds. Overall, WEPP simulations indicate that the storms that are most likely to produce the greatest runoff and sediment load in these coastal, maritime climates with relatively low rainfall intensities are likely to occur in the winter when the soils are not water repellant. The erosion rates varied from 0.34 tonnes/ha/year to 37.3 tonnes/ha/year with the most vulnerable slopes being those associated with steep shallow soils. The summation of the 10-year return period annual delivered sediment from all the watersheds for the worst case scenario during winter months is 17% greater than the total sediment delivery for the real case scenarios. Despite the data limitations, this analysis provides insight into the critical watersheds that will be major source areas of sediment following a wildfire. Watershed managers can use this information to plan and prioritize post-wildfire rehabilitation strategies and actions to minimize the risk of sediment delivery from the hillslopes that generate the greatest amount of sediment.

Simulating nitrate response functions in watersheds: Case studies in the United States and New Zealand

NASA Astrophysics Data System (ADS)

Gusyev, Maksym; Abrams, Daniel; Morgenstern, Uwe; Stewart, Michael

2016-04-01

Non-point sources of nitrate contamination are a common concern in different parts of the world and are difficult to characterize. Due to the solubility of nitrate, it easily enters groundwater and may take years or decades to completely flush to a stream. During this time, it may undergo denitrification, in particular if dissolved oxygen levels are low, requiring a representation of spatially distributed nitrate input as well as detailed hydrogeology. In this presentation, nitrate response functions are generated with four different methodologies that are listed in the order of decreasing degrees of freedom: groundwater flow and chemical transport (MODFLOW/MT3D), groundwater flow with solute particle tracing (MODFLOW/MODPATH), cross-sectional groundwater flow model (MODFLOW), and lumped parameter models (LPMs). We tested these approaches in selected watersheds in the Eastern and Midwestern United States as well as New Zealand and found similar nitrate results in all cases despite different model complexities. It is noted that only the fully three dimensional MODFLOW models with MT3D or MODPATH could account for detailed patterns of land use and nitrate applications; the cross-sectional models and lumped parameter models could only do so approximately. Denitrification at depth could also be explicitly accounted for in all four approaches, although this was not a major factor in any of the watersheds investigated.

Evaluation of the Agro-EcoSystem-Watershed (AgES-W)model for estimating nutrient dynamics on a midwest agricultural watershed

USDA-ARS?s Scientific Manuscript database

In order to satisfy the requirements of Conservation Effects Assessment Project (CEAP) Watershed Assessment Study (WAS) Objective 5 (“develop and verify regional watershed models that quantify environmental outcomes of conservation practices in major agricultural regions”), a new watershed model dev...

Multi-gauge Calibration for modeling the Semi-Arid Santa Cruz Watershed in Arizona-Mexico Border Area Using SWAT

USGS Publications Warehouse

Niraula, Rewati; Norman, Laura A.; Meixner, Thomas; Callegary, James B.

2012-01-01

In most watershed-modeling studies, flow is calibrated at one monitoring site, usually at the watershed outlet. Like many arid and semi-arid watersheds, the main reach of the Santa Cruz watershed, located on the Arizona-Mexico border, is discontinuous for most of the year except during large flood events, and therefore the flow characteristics at the outlet do not represent the entire watershed. Calibration is required at multiple locations along the Santa Cruz River to improve model reliability. The objective of this study was to best portray surface water flow in this semiarid watershed and evaluate the effect of multi-gage calibration on flow predictions. In this study, the Soil and Water Assessment Tool (SWAT) was calibrated at seven monitoring stations, which improved model performance and increased the reliability of flow, in the Santa Cruz watershed. The most sensitive parameters to affect flow were found to be curve number (CN2), soil evaporation and compensation coefficient (ESCO), threshold water depth in shallow aquifer for return flow to occur (GWQMN), base flow alpha factor (Alpha_Bf), and effective hydraulic conductivity of the soil layer (Ch_K2). In comparison, when the model was established with a single calibration at the watershed outlet, flow predictions at other monitoring gages were inaccurate. This study emphasizes the importance of multi-gage calibration to develop a reliable watershed model in arid and semiarid environments. The developed model, with further calibration of water quality parameters will be an integral part of the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM), an online decision support tool, to assess the impacts of climate change and urban growth in the Santa Cruz watershed.

Influence of solid waste and topography on urban floods: The case of Mexico City.

PubMed

Zambrano, Luis; Pacheco-Muñoz, Rodrigo; Fernández, Tania

2018-02-24

Floods in cities are increasingly common as a consequence of multifactor watershed dynamics, including geomorphology, land-use changes and land subsidence. However, urban managers have focused on infrastructure to address floods by reducing blocked sewage infrastructure, without significant success. Using Mexico City as a case study, we generated a spatial flood risk model with geomorphology and anthropogenic variables. The results helped contrast the implications of different public policies in land use and waste disposal, and correlating them with flood hazards. Waste disposal was only related to small floods. 58% of the city has a high risk of experiencing small floods, and 24% of the city has a risk for large floods. Half of the population with the lowest income is located in the high-risk areas for large floods. These models are easy to build, generate fast results and are able to help to flood policies, by understanding flood interactions in urban areas within the watershed.

Seasonal change of non-point source pollution-induced bioavailable phosphorus loss: A case study of Southwestern China

NASA Astrophysics Data System (ADS)

Gao, Yang; Zhu, Bo; Wang, Tao; Wang, Yafeng

2012-02-01

SummaryBioavailable phosphorus (P) losses due to agriculture activity in a purple soil watershed in the Sichuan Basin of Southwestern China were monitored to define the hydrological controls of P transport. Our results indicate that the proportion of P that was transported in particulate form increased in the rainy season, and that the mass of total bioavailable P (BAP) loads exhibited seasonal fluctuations, wherein the majority (over 90%) was observed to have been exported between June and September. The proportion of bioavailable dissolved P (BDP) in the BAP discharge budget in the watershed varied between 11% and 15% during the monitoring period. The bioavailable particulate P (BPP) and BDP concentrations of stream water under rainstorm events increased by over 40% in comparison to their annual mean concentrations, and the annual BAP load was primarily dominated by the loads that occurred during rainstorm events in the study year. BAP concentration in groundwater significantly fluctuated with the seasons, and the ratio of total BAP in groundwater to that in surface water gradually increased during the rainy season. Thus, the impact of agriculture on the water quality of this watershed becomes clearly evident.

Flood predictions using the parallel version of distributed numerical physical rainfall-runoff model TOPKAPI

NASA Astrophysics Data System (ADS)

Boyko, Oleksiy; Zheleznyak, Mark

2015-04-01

The original numerical code TOPKAPI-IMMS of the distributed rainfall-runoff model TOPKAPI ( Todini et al, 1996-2014) is developed and implemented in Ukraine. The parallel version of the code has been developed recently to be used on multiprocessors systems - multicore/processors PC and clusters. Algorithm is based on binary-tree decomposition of the watershed for the balancing of the amount of computation for all processors/cores. Message passing interface (MPI) protocol is used as a parallel computing framework. The numerical efficiency of the parallelization algorithms is demonstrated for the case studies for the flood predictions of the mountain watersheds of the Ukrainian Carpathian regions. The modeling results is compared with the predictions based on the lumped parameters models.

The Kings River Experimental Watersheds: new findings about headwater streams of the southern Sierra Nevada

Treesearch

Carolyn Hunsaker

2013-01-01

The Kings River Experimental Watersheds (KREW) study was designed to (1) characterize the variability in watershed attributes considered important to understanding processes and health of headwater streams and forest watersheds and (2) evaluate forest restoration treatments. The KREW is a paired watershed experiment located in the headwaters of the Kings River Basin...

The development of a hydrologic-hydraulic representation of an urbanscape: the case study of Nashville, Tennessee

NASA Astrophysics Data System (ADS)

Sedlar, F.; Ivanov, V. Y.; Shao, J.; Narayan, U.; Nardi, F.; Adams, T. E.; Merwade, V.; Wright, D. B.; Kim, J.; Fatichi, S.; Rakhmatulina, E.

2013-12-01

Incorporating elevation data into coupled hydraulic and hydrologic models with the use of triangulated irregular networks (TINs) provides a detailed and highly customizable representation of the original domain. Until recently the resolution of such digital elevation models was 1 or 1/3 arc second (10-30 meters). Aided by the use of LiDAR, digital elevation models are now available at the 1/9 arc second resolution (1-3 meters). With elevation data at this level of resolution watershed details that are overlooked at a 10-30 meter resolution can now be resolved and incorporated into the TIN. For urban flood modeling this implies that street level features can be resolved. However to provide a useful picture of the flooding as a whole, this data would need to be integrated across a citywide scale. To prove the feasibility, process, and capabilities of generating such a detailed and large scale TIN, we present a case study of Nashville, TN, USA, during the May 1-2, 2010 flooding, a 1,000 year storm event. With the use of ArcGIS, HEC-RAS, Triangle, and additionally developed processing methodologies, an approach is developed to generate a hydrologically relevant and detailed TIN of the entire urbanscape of Nashville. This TIN incorporates three separate aspects; the watershed, the floodplain, and the city. The watershed component contains the elevation data for the delineated watershed, roughly 1,000 km2 at 1-3 meter resolution. The floodplain encompasses over 300 channel cross sections of the Cumberland River and a delineated floodplain. The city element comprises over 500,000 buildings and all major roadways within the watershed. Once generated, the resulting triangulation of the TIN is optimized with the Triangle software for input to the coupled hydraulic and hydrological model, tRIBS-OFM. Hydrologically relevant areas such as the floodplain are densified and constraints are set on the minimum triangle area for the entire TIN. Upon running the coupled hydraulic and hydrological model with the appropriate forcings, the spatial dynamics of the flooding will then be resolved at a street level across the entire city. The analysis capabilities afforded at this resolution and across such a large area will facilitate urban flood predictions coupled with hydrologic forecasts as well as a better understanding of the spatial dynamics of urban flooding.

Prioritizing watersheds for conservation actions in the southeastern coastal plain ecoregion.

PubMed

Jang, Taeil; Vellidis, George; Kurkalova, Lyubov A; Boll, Jan; Hyman, Jeffrey B

2015-03-01

The aim of this study was to apply and evaluate a recently developed prioritization model which uses the synoptic approach to geographically prioritize watersheds in which Best Management Practices (BMPs) can be implemented to reduce water quality problems resulting from erosion and sedimentation. The model uses a benefit-cost framework to rank candidate watersheds within an ecoregion or river basin so that BMP implementation within the highest ranked watersheds will result in the most water quality improvement per conservation dollar invested. The model was developed to prioritize BMP implementation efforts in ecoregions containing watersheds associated with the USDA-NRCS Conservation Effects Assessment Project (CEAP). We applied the model to HUC-8 watersheds within the southeastern Coastal Plain ecoregion (USA) because not only is it an important agricultural area but also because it contains a well-studied medium-sized CEAP watershed which is thought to be representative of the ecoregion. The results showed that the three HUC-8 watersheds with the highest rankings (most water quality improvement expected per conservation dollar invested) were located in the southern Alabama, northern Florida, and eastern Virginia. Within these watersheds, measures of community attitudes toward conservation practices were highly ranked, and these indicators seemed to push the watersheds to the top of the rankings above other similar watersheds. The results, visualized as maps, can be used to screen and reduce the number of watersheds that need further assessment by managers and decision-makers within the study area. We anticipate that this model will allow agencies like USDA-NRCS to geographically prioritize BMP implementation efforts.

Modeling post-fire hydro-geomorphic recovery in the Waldo Canyon Fire

NASA Astrophysics Data System (ADS)

Kinoshita, Alicia; Nourbakhshbeidokhti, Samira; Chin, Anne

2016-04-01

Wildfire can have significant impacts on watershed hydrology and geomorphology by changing soil properties and removing vegetation, often increasing runoff and soil erosion and deposition, debris flows, and flooding. Watershed systems may take several years or longer to recover. During this time, post-fire channel changes have the potential to alter hydraulics that influence characteristics such as time of concentration and increase time to peak flow, flow capacity, and velocity. Using the case of the 2012 Waldo Canyon Fire in Colorado (USA), this research will leverage field-based surveys and terrestrial Light Detection and Ranging (LiDAR) data to parameterize KINEROS2 (KINematic runoff and EROSion), an event oriented, physically-based watershed runoff and erosion model. We will use the Automated Geospatial Watershed Assessment (AGWA) tool, which is a GIS-based hydrologic modeling tool that uses commonly available GIS data layers to parameterize, execute, and spatially visualize runoff and sediment yield for watersheds impacted by the Waldo Canyon Fire. Specifically, two models are developed, an unburned (Bear Creek) and burned (Williams) watershed. The models will simulate burn severity and treatment conditions. Field data will be used to validate the burned watersheds for pre- and post-fire changes in infiltration, runoff, peak flow, sediment yield, and sediment discharge. Spatial modeling will provide insight into post-fire patterns for varying treatment, burn severity, and climate scenarios. Results will also provide post-fire managers with improved hydro-geomorphic modeling and prediction tools for water resources management and mitigation efforts.

Assessing stream water quality in watersheds with contrasting land use in Navarre (Spain)

NASA Astrophysics Data System (ADS)

Casalí, Javier; Giménez, Rafael; Díez, Javier

2010-05-01

Four experimental watersheds in Navarre (Spain), maintained by the local government and with different land uses, have been monitored and studied since 1996 (La Tejería and Latxaga) and 2001 (Oskotz 'principal', Op and Oskotz 'woodland', Ow). In previous publications, a detailed description was given of their hydrological and erosion behaviour, as well as their production of nitrates, phosphates and potassium, all these chemicals being directly related to agricultural activity (fertilization). However, the dynamics of an equally large series of other important solutes -bicarbonates, carbonates, sulphates, chlorine, calcium, magnesium and sodium- also conditionants of water quality- had not been analyzed up to now. Thus, the objective proposed in this work was the exhaustive analysis of chemical erosion in experimental watersheds with contrasting land use. La Tejería and Latxaga watersheds located in the central western part of Navarre, are roughly similar to each other regarding size (approximately 200 ha), geology (marls and sandstones), soils (alkaline, fine texture topsoil), climate (humid sub Mediterranean) and land use (80-90% cultivated with winter grain crops). On the other hand, Op watershed (ca.1,700 ha) is covered with forest and pasture (cattle-breeding); while Ow (ca. 500 ha), a sub-watershed of the Op, is almost completely covered with forest. The predominant climate in Op/Ow is Sub-Atlantic, with a mean annual rainfall of 1,200 mm and a mean annual temperature of 12°C. The average annual production of solutes as a whole was considerably higher in Op/Ow (1,653 ± 245 kg ha-1) than in the grain growing watersheds; it was precisely the lower record which corresponded to the Latxaga watershed (715 ± 292 kg ha-1). However, only two solutes (bicarbonate and calcium) account for approximately 90% of the total in Op/Ow, this predominance being even greater in the grain-cultivated watersheds due to their alkaline soils, rich in carbonates. Even so, only one minority solute, nitrate, exceeded the tolerance limit (50 mg l-1), although exclusively in La Tejería watershed with an annual mean value of 87 ± 15 mg NO3 l-1 and occasional maxima of 100 mg l-1. In Latxaga, the annual mean concentration (24 ± 12 mg NO3 l-1) was normally under the thresholds permitted but with occasional peaks exceeding it. Also, in the grain-cultivated watersheds -not so in Op/Ow- the high nitrate concentrations together with values -not very high but important ones- of phosphates (0.20 ± 0.15 mg PO4 l-1) could cause alarming eutrophication problems. It should be noted that the phosphate production in grain-growing watersheds -and in spite of the intensive fertilization carried out in both watersheds- was lower than that recorded in Op/Ow. This was due to the important fixation of phosphate produced in the calcareous soils predominating in the grain cultivated watersheds. The rest of the solutes analyzed exhibited marked differences in their records depending on the land use, although in no case did they exceed tolerance thresholds for drinking water. Finally, we mention that chemical erosion in Op/Ow is more important -around 70%- than that of sediment (soil erosion). By contrast, soil erosion is slightly higher than chemical one in the grain-growing watersheds.

[Influence of land use change on dissolved organic carbon export in Naoli River watershed. Northeast China].

PubMed

Yin, Xiao-min; Lyu, Xian-guo; Liu, Xing-tu; Xue, Zhen-shan

2015-12-01

The present study was conducted to evaluate the influence of land use change on dissolved organic carbon (DOC) export in Naoli River watershed, Northeast China. Seasonal variation of DOC concentrations of the river water and its relationship with land use in the whole watershed and 100 m riparian zone at the annual average scale were analyzed using the method of field sampling, laboratory analysis, GIS and statistics analysis. The results showed that the concentrations of DOC under base flow conditions in spring and summer were significantly higher than that in fall in the study watershed. The seasonal trend of DOC concentrations in wetland-watersheds was similar to that in all the sub-watersheds, while significantly different from that in non-wetland watersheds. On the annual average scale, percentage of wetland in the whole watershed and paddy field in the 100 m riparian zone had positive relationship with the DOC concentration in the river water, while percentage of forest in the whole watershed had negative relationship with it (P < 0.05). It indicated that wetland in the sub-watershed played a significant role in the seasonal variation of DOC in river water of Naoli River watershed. Wetland in the watershed and paddy field in the 100 m riparian zone significantly promoted DOC export, while forest alleviated it. Land use change in the watershed in the past few decades dramatically changed the DOC balance of river water.

Influences of frozen ground and climate change on hydrological processes in an alpine watershed: A case study in the upstream area of the Hei’he River, Northwest China

USDA-ARS?s Scientific Manuscript database

Frozen soil prevails in cold regions and exerts significant influence on the hydrological cycle. In the context of climate warming, the spatial and temporal dynamics of frozen soil and hydrological processes also will change. How these changes inter-relate is a key challenge in studies of hydrologic...

Eleven-year response of foliar chemistry to chronic nitrogen and sulfur additions at the Bear Brook Watershed in Maine

Treesearch

Jose Alexander Elvir; Lindsey Rustad; G. Bruce Wiersma; Ivan Fernandez; Alan S. White; Gregory J. White

2005-01-01

The foliar chemistry of sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Ehrh.), and red spruce (Picea rubens Sarg.) was studied from 1993 to 2003 at the Bear Brook Watershed in Maine (BBWM). The BBWM is a paired-watershed forest ecosystem study, with one watershed treated bimonthly since...

Joint analysis of input and parametric uncertainties in watershed water quality modeling: A formal Bayesian approach

NASA Astrophysics Data System (ADS)

Han, Feng; Zheng, Yi

2018-06-01

Significant Input uncertainty is a major source of error in watershed water quality (WWQ) modeling. It remains challenging to address the input uncertainty in a rigorous Bayesian framework. This study develops the Bayesian Analysis of Input and Parametric Uncertainties (BAIPU), an approach for the joint analysis of input and parametric uncertainties through a tight coupling of Markov Chain Monte Carlo (MCMC) analysis and Bayesian Model Averaging (BMA). The formal likelihood function for this approach is derived considering a lag-1 autocorrelated, heteroscedastic, and Skew Exponential Power (SEP) distributed error model. A series of numerical experiments were performed based on a synthetic nitrate pollution case and on a real study case in the Newport Bay Watershed, California. The Soil and Water Assessment Tool (SWAT) and Differential Evolution Adaptive Metropolis (DREAM(ZS)) were used as the representative WWQ model and MCMC algorithm, respectively. The major findings include the following: (1) the BAIPU can be implemented and used to appropriately identify the uncertain parameters and characterize the predictive uncertainty; (2) the compensation effect between the input and parametric uncertainties can seriously mislead the modeling based management decisions, if the input uncertainty is not explicitly accounted for; (3) the BAIPU accounts for the interaction between the input and parametric uncertainties and therefore provides more accurate calibration and uncertainty results than a sequential analysis of the uncertainties; and (4) the BAIPU quantifies the credibility of different input assumptions on a statistical basis and can be implemented as an effective inverse modeling approach to the joint inference of parameters and inputs.

The effect of community based soil conservation works on runoff and sediment loss in the Ethiopian highlands: case of Birr Watershed

USDA-ARS?s Scientific Manuscript database

Soil erosion is a serious problem in the Ethiopian highlands. Conventional erosion control approaches have generally been ineffective in halting this problem. The presented study measured precipitation, sediment yield and stream flow in 2013 and 2014 in the Ene-Chilala subwatershed of the Birr River...

REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEMS FOR DECISION ANALYSIS IN PUBLIC RESOURCE ADMINISTRATION: A CASE STUDY OF 25 YEARS OF LANDSCAPE CHANGE IN A SOUTHWESTERN WATERSHED

EPA Science Inventory

Alternative futures analysis is a scenario-based approach to regional land planning that attempts to synthesize existing scientific information in a format useful to community decision-makers. Typically, this approach attempts to investigate the impacts of several alternative set...

Support increased adoption of green infrastructure into community stormwater management plans and watershed sustainability goals: Information and guidance through community partnerships

EPA Science Inventory

This project will provide technical assistance to support implementation of GI in U.S. communities and information on best practices for GI approaches that protect ground water supplies. Case studies that can be more broadly applied to other communities will be conducted. The pro...

Evaluation of a collaborative model: a case study analysis of watershed planning in the intermountain west

Treesearch

Gary Bentrup

2001-01-01

Collaborative planning processes have become increasingly popular for addressing environmental planning issues, resulting in a number of conceptual models for collaboration. A model proposed by Selin and Chavez suggests that collaboration emerges from a series of antecedents and then proceeds sequentially through problem-setting, direction-setting, implementation, and...

Managing the space-time-load continuum in TMDL planning: A case study for understanding groundwater loads through advanced mapping techniques

EPA Science Inventory

The lag time between groundwater recharge and discharge in a watershed and the potential groundwater load to streams is an important factor in forecasting responses to future land use practices. We call this concept managing the “space-time-load continuum”. It’s understood that i...

Recovery of decomposition and soil microarthropod communities in a clearcut watershed in the Southern Appalachians

Treesearch

Liam Heneghan; Alissa Salmore

2014-01-01

The recovery of ecosystems after disturbance remains a productive theme for ecological research. Numerous studies have focused either on the reestablishment of biological communities or on the recovery of ecosystem processes after perturbations. In the case of decomposer organisms an the processes of organic matter decay and the mineralization of nutrients, the...

Riparian restoration in the Southwest: Species selection, propagation, planting methods, and case studies

Treesearch

David Dreesen; John Harrington; Tom Subirge; Pete Stewart; Greg Fenchel

2002-01-01

Riparian plant communities, though small in overall area, are among the most valuable natural areas in the Southwest. The causes of degradation of southwestern riparian zones range from excessive cattle and elk grazing in montane watersheds to invasive woody exotic species and lack of natural flooding in the cottonwood forests, "bosque," of low elevation...

Using photographic image analysis to assess ground cover: a case study of forest road cutbanks

Treesearch

Kevin C. Bold; Frederica Wood; Pamela J. Edwards; Karl W.J. Williard; Jon E. Schoonover

2010-01-01

Road prisms, including cutbanks, road surfaces, and fillslopes, can be important contributors of sediment to streams in forested watersheds. Following road construction, cutbanks and fillslopes are often seeded, mulched, and sometimes fertilized to limit erosion and sedimentation. Assessing the success of vegetation establishment on cutbanks and fillslopes is a common...

Spatial complementarity of forests and farms: accounting for ecosystem services

Treesearch

Subhrendu K. Pattanayak; David T. Butry

2006-01-01

Our article considers the economic contributions of forest ecosystem services, using a case study from Flores, Indonesia, in which forest protection in upstream watersheds stabilize soil and hydrological flows in downstream farms. We focus on the demand for a weak complement to the ecosystem services--farm labor-- and account for spatial dependence due to economic...

Community-based approaches to strategic environmental assessment: Lessons from Costa Rica

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

Sinclair, A. John; Sims, Laura; Spaling, Harry

This paper describes a community-based approach to strategic environmental assessment (SEA) using a case study of the Instituto Costarricense de Electricidad's (ICE) watershed management agricultural program (WMAP) in Costa Rica. The approach focused on four highly interactive workshops that used visioning, brainstorming and critical reflection exercises. Each workshop represented a critical step in the SEA process. Through this approach, communities in two rural watersheds assessed the environmental, social and economic impacts of a proposed second phase for WMAP. Lessons from this community-based approach to strategic environmental assessment include a recognition of participants learning what a participatory SEA is conceptually andmore » methodologically; the role of interactive techniques for identifying positive and negative impacts of the proposed program and generating creative mitigation strategies; the effect of workshops in reducing power differentials among program participants (proponent, communities, government agencies); and, the logistical importance of notice, timing and location for meaningful participation. The community-based approach to SEA offers considerable potential for assessing regional (watershed) development programs focused on sustainable resource-based livelihoods.« less

Effect of environmental setting on sediment, nitrogen, and phosphorus concentrations in Albemarle-Pamlico drainage basin, North Carolina and Virginia, USA

USGS Publications Warehouse

McMahon, G.; Harned, D.A.

1998-01-01

Environmental settings were defined, through an overlay process, as areas of coincidence between categories of three mapped variables - land use, surficial geology, and soil drainage characteristics. Expert judgment was used in selecting factors thought to influence sediment and nutrient concentrations in the Albemarle-Pamlico drainage area. This study's findings support the hypothesis that environmental settings defined using these three variables can explain variations in the concentration of certain sediment and nutrient constituents. This finding underscores the importance of developing watershed management plans that account for differences associated with the mosaic of natural and anthropogenic factors that define a basin's environmental setting. At least in the case of sediment and nutrients in the Albemarle-Pamlico region, a watershed management plan that focuses only on anthropogenic factors, such as point-source discharges, and does not account for natural characteristics of a watershed and the influences of these characteristics on water quality, may lead to water-quality goals that are over- or underprotective of key environmental features and to a misallocation of the resources available for environmental protection.

Multi-Scale Drought Analysis using Thermal Remote Sensing: A Case Study in Georgia’s Altamaha River Watershed

NASA Astrophysics Data System (ADS)

Jacobs, J. M.; Bhat, S.; Choi, M.; Mecikalski, J. R.; Anderson, M. C.

2009-12-01

The unprecedented recent droughts in the Southeast US caused reservoir levels to drop dangerously low, elevated wildfire hazard risks, reduced hydropower generation and caused severe economic hardships. Most drought indices are based on recent rainfall or changes in vegetation condition. However in heterogeneous landscapes, soils and vegetation (type and cover) combine to differentially stress regions even under similar weather conditions. This is particularly true for the heterogeneous landscapes and highly variable rainfall in the Southeastern United States. This research examines the spatiotemperal evolution of watershed scale drought using a remotely sensed stress index. Using thermal-infrared imagery, a fully automated inverse model of Atmosphere-Land Exchange (ALEXI), GIS datasets and analysis tools, modeled daily surface moisture stress is examined at a 10-km resolution grid covering central to southern Georgia. Regional results are presented for the 2000-2008 period. The ALEXI evaporative stress index (ESI) is compared to existing regional drought products and validated using local hydrologic measurements in Georgia’s Altamaha River watershed at scales from 10 to 10,000 km2.

Understanding the behavior of Giardia and Cryptosporidium in an urban watershed: Explanation and application of techniques to collect and evaluate monitoring data

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

Crockett, C.S.; Haas, C.N.

1996-11-01

Due to current proposed regulations requiring monitoring for protozoans and demonstration of adequate protozoan removal depending on source water concentrations detected, many utilities are considering or are engaged in protozoan monitoring activities within their watershed so that proper watershed management and treatment modifications can reduce their impact on drinking water safety and quality. However, due to the difficulties associated with the current analytical methods and sample collection many sampling efforts collect data that cannot be interpreted or lack the tools to interpret the information obtained. Therefore, it is necessary to determine how to develop an effective sampling program tailored tomore » a utility`s specific needs to provide interpretable data and develop tools for evaluating such data. The following case study describes the process in which a utility learned how to collect and interpret monitoring data for their specific needs and provides concepts and tools which other utilities can use to aid in their own macro and microwatershed management efforts.« less

Lake-specific responses to elevated atmospheric nitrogen deposition in the Colorado Rocky Mountains, U.S.A.

USGS Publications Warehouse

Nydick, K.R.; LaFrancois, B.M.; Baron, Jill S.; Johnson, B.M.

2003-01-01

We explored variability among subalpine lakes sharing very similar climate and atmospheric conditions, but differing in watershed characteristics, hydrology, and food web structure. Special attention was given to nitrogen (N) dynamics because the study area receives some of the highest levels of atmospheric N deposition in the Rocky Mountains. We asked if the effect of regional N deposition would be manifested uniformly among neighboring lakes both in terms of ambient conditions and responses to greater nutrient inputs. Catchment vegetation appeared to be the main determinant of ambient nitrate (NO3), phosphate (PO4), and dissolved organic carbon (DOC) concentrations, although in-lake differences in recycling produced variable and contrasting NH4 levels. Phytoplankton chlorophyll a temporarily responded to early season NO3 peaks in the lakes with rocky watersheds, but chlorophyll means over the ice-free season were remarkably similar among lakes despite differences in both nutrient supply and zooplankton grazing. In most cases, phosphorus was limiting to phytoplankton growth, although the importance of N deficiencies was greater in lakes with forested watersheds and fringing wetlands.

Lake-specific responses to elevated atmospheric nitrogen deposition in the Colorado Rocky Mountains, U.S.A

USGS Publications Warehouse

Nydick, K.R.; LaFrancois, B.M.; Baron, Jill S.; Johnson, B.M.

2003-01-01

We explored variability among subalpine lakes sharing very similar climate and atmospheric conditions, but differing in watershed characteristics, hydrology, and food web structure. Special attention was given to nitrogen (N) dynamics because the study area receives some of the highest levels of atmospheric N deposition in the Rocky Mountains. We asked if the effect of regional N deposition would be manifested uniformly among neighboring lakes both in terms of ambient conditions and responses to greater nutrient inputs. Catchment vegetation appeared to be the main determinant of ambient nitrate (NO3), phosphate (PO4), and dissolved organic carbon (DOC) concentrations, although in-lake differences in recycling produced variable and contrasting NH4 levels. Phytoplankton chlorophyll atemporarily responded to early season NO3 peaks in the lakes with rocky watersheds, but chlorophyll means over the ice-free season were remarkably similar among lakes despite differences in both nutrient supply and zooplankton grazing. In most cases, phosphorus was limiting to phytoplankton growth, although the importance of N deficiencies was greater in lakes with forested watersheds and fringing wetlands.

Developing a Three Processes Framework to Analyze Hydrologic Performance of Urban Stormwater Management in a Watershed Scale

NASA Astrophysics Data System (ADS)

Lyu, H.; Ni, G.; Sun, T.

2016-12-01

Urban stormwater management contributes to recover water cycle to a nearly natural situation. It is a challenge for analyzing the hydrologic performance in a watershed scale, since the measures are various of sorts and scales and work in different processes. A three processes framework is developed to simplify the urban hydrologic process on the surface and evaluate the urban stormwater management. The three processes include source utilization, transfer regulation and terminal detention, by which the stormwater is controlled in order or discharged. Methods for analyzing performance are based on the water controlled proportions by each process, which are calculated using USEPA Stormwater Management Model. A case study form Beijing is used to illustrate how the performance varies under a set of designed events of different return periods. This framework provides a method to assess urban stormwater management as a whole system considering the interaction between measures, and to examine if there is any weak process of an urban watershed to be improved. The results help to make better solutions of urban water crisis.

Analyzing climate change impacts on water resources under uncertainty using an integrated simulation-optimization approach

NASA Astrophysics Data System (ADS)

Zhuang, X. W.; Li, Y. P.; Nie, S.; Fan, Y. R.; Huang, G. H.

2018-01-01

An integrated simulation-optimization (ISO) approach is developed for assessing climate change impacts on water resources. In the ISO, uncertainties presented as both interval numbers and probability distributions can be reflected. Moreover, ISO permits in-depth analyses of various policy scenarios that are associated with different levels of economic consequences when the promised water-allocation targets are violated. A snowmelt-precipitation-driven watershed (Kaidu watershed) in northwest China is selected as the study case for demonstrating the applicability of the proposed method. Results of meteorological projections disclose that the incremental trend of temperature (e.g., minimum and maximum values) and precipitation exist. Results also reveal that (i) the system uncertainties would significantly affect water resources allocation pattern (including target and shortage); (ii) water shortage would be enhanced from 2016 to 2070; and (iii) the more the inflow amount decreases, the higher estimated water shortage rates are. The ISO method is useful for evaluating climate change impacts within a watershed system with complicated uncertainties and helping identify appropriate water resources management strategies hedging against drought.

Modeling of Soil Erosion by IntErO model: The Case Study of the Novsicki Potok Watershed, of the Prokletije high mountains of Montenegro

NASA Astrophysics Data System (ADS)

Spalevic, Velibor; Al-Turki, Ali M.; Barovic, Goran; Leandro Naves Silva, Marx; Djurovic, Nevenka; Soares Souza, Walisson; Veloso Gomes Batista, Pedro; Curovic, Milic

2016-04-01

The application of soil conservation programs to combat erosion and sedimentation are significantly contributing to the protection of the natural resources. Watershed management practices include the assessment of Physical-Geographical, Climate, Geological, Pedological characteristics, including the analysis of Land Use of the regions concerned. The policy makers are increasingly looking for the different land uses and climatic scenarios that can be used for valuable projections for watershed management. To increase knowledge about those processes, use of hydrological and soil erosion models is needed and that is allowing quantification of soil redistribution and sediment productions. We focused on soil erosion processes in one of Northern Montenegrin mountain watersheds, the Novsicki Potok Watershed of the Polimlje River Basin, using modeling techniques: the IntErO model for calculation of runoff and soil loss. The model outcomes were validated through measurements of lake sediment deposition at the Potpec hydropower plant dam. Our findings indicate a medium potential of soil erosion risk. With 464 m³ yr-1 of annual sediment yield, corresponding to an area-specific sediment yield of 270 m³km-2 yr-1, the Novsicki Potok drainage basin belongs to the Montenegrin basins with the medium sediment discharge; according to the erosion type, it is surface erosion. The value of the Z coefficient was calculated on 0.403, what indicates that the river basin belongs to 3rd destruction category (of five). Our results suggest that the calculated peak discharge from the river basin was 82 m3s-1 for the incidence of 100 years. According to our analysis there is a possibility for large flood waves to appear in the studied river basin. With this research we, to some extent, improved the knowledge on the status of sediment yield and runoff of the river basins of Montenegro, where the map of Soil erosion is still not prepared. The IntErO model we used in this study is relatively novel concept and is highly recommended for soil erosion modelling in other river basins similar to the studied watershed, because of its simple identification of critical areas affected by the soil loss caused by soil erosion.

Approaches to stream solute load estimation for solutes with varying dynamics from five diverse small watershed

USGS Publications Warehouse

Aulenbach, Brent T.; Burns, Douglas A.; Shanley, James B.; Yanai, Ruth D.; Bae, Kikang; Wild, Adam; Yang, Yang; Yi, Dong

2016-01-01

Estimating streamwater solute loads is a central objective of many water-quality monitoring and research studies, as loads are used to compare with atmospheric inputs, to infer biogeochemical processes, and to assess whether water quality is improving or degrading. In this study, we evaluate loads and associated errors to determine the best load estimation technique among three methods (a period-weighted approach, the regression-model method, and the composite method) based on a solute's concentration dynamics and sampling frequency. We evaluated a broad range of varying concentration dynamics with stream flow and season using four dissolved solutes (sulfate, silica, nitrate, and dissolved organic carbon) at five diverse small watersheds (Sleepers River Research Watershed, VT; Hubbard Brook Experimental Forest, NH; Biscuit Brook Watershed, NY; Panola Mountain Research Watershed, GA; and Río Mameyes Watershed, PR) with fairly high-frequency sampling during a 10- to 11-yr period. Data sets with three different sampling frequencies were derived from the full data set at each site (weekly plus storm/snowmelt events, weekly, and monthly) and errors in loads were assessed for the study period, annually, and monthly. For solutes that had a moderate to strong concentration–discharge relation, the composite method performed best, unless the autocorrelation of the model residuals was <0.2, in which case the regression-model method was most appropriate. For solutes that had a nonexistent or weak concentration–discharge relation (modelR2 < about 0.3), the period-weighted approach was most appropriate. The lowest errors in loads were achieved for solutes with the strongest concentration–discharge relations. Sample and regression model diagnostics could be used to approximate overall accuracies and annual precisions. For the period-weighed approach, errors were lower when the variance in concentrations was lower, the degree of autocorrelation in the concentrations was higher, and sampling frequency was higher. The period-weighted approach was most sensitive to sampling frequency. For the regression-model and composite methods, errors were lower when the variance in model residuals was lower. For the composite method, errors were lower when the autocorrelation in the residuals was higher. Guidelines to determine the best load estimation method based on solute concentration–discharge dynamics and diagnostics are presented, and should be applicable to other studies.

Integrated watershed- and farm-scale modeling framework for targeting critical source areas while maintaining farm economic viability.

PubMed

Ghebremichael, Lula T; Veith, Tamie L; Hamlett, James M

2013-01-15

Quantitative risk assessments of pollution and data related to the effectiveness of mitigating best management practices (BMPs) are important aspects of nonpoint source pollution control efforts, particularly those driven by specific water quality objectives and by measurable improvement goals, such as the total maximum daily load (TMDL) requirements. Targeting critical source areas (CSAs) that generate disproportionately high pollutant loads within a watershed is a crucial step in successfully controlling nonpoint source pollution. The importance of watershed simulation models in assisting with the quantitative assessments of CSAs of pollution (relative to their magnitudes and extents) and of the effectiveness of associated BMPs has been well recognized. However, due to the distinct disconnect between the hydrological scale in which these models conduct their evaluation and the farm scale at which feasible BMPs are actually selected and implemented, and due to the difficulty and uncertainty involved in transferring watershed model data to farm fields, there are limited practical applications of these tools in the current nonpoint source pollution control efforts by conservation specialists for delineating CSAs and planning targeting measures. There are also limited approaches developed that can assess impacts of CSA-targeted BMPs on farm productivity and profitability together with the assessment of water quality improvements expected from applying these measures. This study developed a modeling framework that integrates farm economics and environmental aspects (such as identification and mitigation of CSAs) through joint use of watershed- and farm-scale models in a closed feedback loop. The integration of models in a closed feedback loop provides a way for environmental changes to be evaluated with regard to the impact on the practical aspects of farm management and economics, adjusted or reformulated as necessary, and revaluated with respect to effectiveness of environmental mitigation at the farm- and watershed-levels. This paper also outlines steps needed to extract important CSA-related information from a watershed model to help inform targeting decisions at the farm scale. The modeling framework is demonstrated with two unique case studies in the northeastern United States (New York and Vermont), with supporting data from numerous published, location-specific studies at both the watershed and farm scales. Using the integrated modeling framework, it can be possible to compare the costs (in terms of changes required in farm system components or financial compensations for retiring crop lands) and benefits (in terms of measurable water quality improvement goals) of implementing targeted BMPs. This multi-scale modeling approach can be used in the multi-objective task of mitigating CSAs of pollution to meet water quality goals while maintaining farm-level economic viability. Copyright © 2012 Elsevier Ltd. All rights reserved.

Simulation of Water Quality in the Tull Creek and West Neck Creek Watersheds, Currituck Sound Basin, North Carolina and Virginia

USGS Publications Warehouse

Garcia, Ana Maria

2009-01-01

A study of the Currituck Sound was initiated in 2005 to evaluate the water chemistry of the Sound and assess the effectiveness of management strategies. As part of this study, the Soil and Water Assessment Tool (SWAT) model was used to simulate current sediment and nutrient loadings for two distinct watersheds in the Currituck Sound basin and to determine the consequences of different water-quality management scenarios. The watersheds studied were (1) Tull Creek watershed, which has extensive row-crop cultivation and artificial drainage, and (2) West Neck Creek watershed, which drains urban areas in and around Virginia Beach, Virginia. The model simulated monthly streamflows with Nash-Sutcliffe model efficiency coefficients of 0.83 and 0.76 for Tull Creek and West Neck Creek, respectively. The daily sediment concentration coefficient of determination was 0.19 for Tull Creek and 0.36 for West Neck Creek. The coefficient of determination for total nitrogen was 0.26 for both watersheds and for dissolved phosphorus was 0.4 for Tull Creek and 0.03 for West Neck Creek. The model was used to estimate current (2006-2007) sediment and nutrient yields for the two watersheds. Total suspended-solids yield was 56 percent lower in the urban watershed than in the agricultural watershed. Total nitrogen export was 45 percent lower, and total phosphorus was 43 percent lower in the urban watershed than in the agricultural watershed. A management scenario with filter strips bordering the main channels was simulated for Tull Creek. The Soil and Water Assessment Tool model estimated a total suspended-solids yield reduction of 54 percent and total nitrogen and total phosphorus reductions of 21 percent and 29 percent, respectively, for the Tull Creek watershed.

Water balance of drained plantation watersheds in North Carolina

Treesearch

Johnny M. Grace; R. W. Skaggs

2006-01-01

A 3-year study to evaluate the effect of thinning on the hydrology of a drained loblolly pine (Pinus taeda L.) plantation was conducted in eastern North Carolina. The study utilized a paired watershed design with a 40-ha thinned watershed (WS5) and a 16-ha control watershed (WS2). Data from the field experiment conducted from 1999-2002 was used to...

Hydrological and hydraulic models for determination of flood-prone and flood inundation areas

NASA Astrophysics Data System (ADS)

Aksoy, Hafzullah; Sadan Ozgur Kirca, Veysel; Burgan, Halil Ibrahim; Kellecioglu, Dorukhan

2016-05-01

Geographic Information Systems (GIS) are widely used in most studies on water resources. Especially, when the topography and geomorphology of study area are considered, GIS can ease the work load. Detailed data should be used in this kind of studies. Because of, either the complication of the models or the requirement of highly detailed data, model outputs can be obtained fast only with a good optimization. The aim in this study, firstly, is to determine flood-prone areas in a watershed by using a hydrological model considering two wetness indexes; the topographical wetness index, and the SAGA (System for Automated Geoscientific Analyses) wetness index. The wetness indexes were obtained in the Quantum GIS (QGIS) software by using the Digital Elevation Model of the study area. Flood-prone areas are determined by considering the wetness index maps of the watershed. As the second stage of this study, a hydraulic model, HEC-RAS, was executed to determine flood inundation areas under different return period-flood events. River network cross-sections required for this study were derived from highly detailed digital elevation models by QGIS. Also river hydraulic parameters were used in the hydraulic model. Modelling technology used in this study is made of freely available open source softwares. Based on case studies performed on watersheds in Turkey, it is concluded that results of such studies can be used for taking precaution measures against life and monetary losses due to floods in urban areas particularly.

Economic Tools for Managing Nitrogen in Coastal Watersheds ...

EPA Pesticide Factsheets

Watershed managers are interested in using economics to communicate the value of estuarine resources to the wider community, determine the most cost-effective means to reduce nitrogen pollution, and evaluate the benefits of taking action to improve coastal ecosystems. We spoke to coastal watershed managers who had commissioned economic studies and found that they were largely satisfied with the information and their ability to communicate the importance of coastal ecosystems. However, while managers were able to use these studies as communication tools, methods used in some studies were inconsistent with what some economists consider best practices. In addition, many watershed managers are grappling with how to implement nitrogen management activities in a way that is both cost-effective and achieves environmental goals, while maintaining public support. These and other issues led to this project. Our intent is to provide information to watershed managers and others interested in watershed management – such as National Estuary Programs, local governments, or nongovernmental organizations – on economic tools for managing nitrogen in coastal watersheds, and to economists and other analysts who are interested in assisting them in meeting their needs. Watershed management requires balancing scientific, political, and social issues to solve environmental problems. This document summarizes questions that watershed managers have about using economic analysis, and g

Persistence and Detectability of Hydrologic Changes Following Multiple Timber Harvest Entries in the Oregon Coast Range: Alsea Revisited

NASA Astrophysics Data System (ADS)

Stednick, J. D.; Ice, G. G.; Hale, V. C.

2006-12-01

The original Alsea Watershed Study (1959-1973) was a paired study in the Oregon Coast Range designed to assess the physical and biological effects of timber harvesting on water and salmonid resources. The 3 streams chosen for study, Deer Creek, Flynn Creek, and Needle Branch, are tributaries of Drift Creek, which flows into Alsea Bay. The watersheds lie about 16 km from the Pacific Ocean, and have a maritime climate, with mean annual precipitation approximately 250 cm, almost all of which falls as rain from October through March. Flynn Creek served as an undisturbed control watershed, Deer Creek had 3 patch cuts (25% of the watershed area) with a streamside vegetation buffer, and Needle Branch was clearcut (85%) with no streamside buffer. The results of the original Alsea Study showed an increase in annual water yield and 3-day peak flows for Needle Branch, and no significant change for any streamflow metric (annual yield, peak flow, or low flows) on Deer Creek. Because the watersheds "generally appear to be returning to pre-logging conditions" the authors of the original study believed hydrologic recovery had occurred. The streamflow gauging network was reestablished in 1990 as the New Alsea Watershed Study. Additional streamflow monitoring (1990-1996) suggested that the watersheds deemed to be "recovered" still showed departures from the pre-treatment relations. Streamflow monitoring from the same period suggested 24 years for vegetation regrowth to return to hydrologic functions similar to the pretreatment. A literature review of paired watershed studies suggested that in the Pacific Northwest at least 25% of the watershed area needed to be harvested to be detectable with streamflow monitoring. Flynn Creek was designated a long-term Research Natural Area by the USDA Forest Service in 1976, and remains an undisturbed temperate coniferous forested watershed. Deer Creek had a second timber harvesting entry in 1978 of 20 ha and two units of 14.5 and 8.4 ha were logged in 1987 and 1988. Approximately 39% of the watershed has now been harvested. Since the original study, forest management on Needle Branch has included precommercial and commercial thinning. Approximately 25% of the middle third of the watershed was precommercially thinned in 1981. In 1997-1998 approximately 40% of this area was commercially thinned with a 30% basal area removal. With 15 years of additional streamflow data, are the 25% basal area removal and 24 year hydrologic recovery axioms true for the Alsea study watersheds?

Scenario analysis of the impacts of socioeconomic development on phosphorous export and loading from the Dongting Lake watershed, China.

PubMed

Hou, Ying; Chen, Weiping; Liao, Yuehua; Luo, Yueping

2017-12-01

Socioeconomic development in lake watersheds is closely related with lake nutrient pollution. As the second largest freshwater lake in China, the Dongting Lake has been experiencing an increase in nutrient loading and a growing risk of eutrophication. This study aimed to reveal the likely impacts of the socioeconomic development of the Dongting Lake watershed on the phosphorous pollution in the lake. We estimated the contributions from different sources and sub-watersheds to the total phosphorous (TP) export and loading from the Dongting Lake watershed under two most likely socioeconomic development scenarios. Moreover, we predicted the likely permissible and actual TP loadings to the Dongting Lake. Under both two scenarios, three secondary sub-watersheds-the upper and lower reaches of the Xiang River watershed and the Dongting Lake Area-are expected to dominate the contribution to the TP export from the Dongting Lake watershed in 2020. Three primary sub-watersheds-the Dongting Lake Area, the Xiang River, and the Yuan River watersheds-are predicted to be the major contributors to the TP loading from the entire watershed. The two scenarios are expected to have a slight difference in TP export and lake TP loading. Livestock husbandry is expected to be the predominant anthropogenic TP source in each of the sub-watersheds under both scenarios. Compared to 2010, permissible TP loading is not expected to increase but actual TP loading is predicted to grow significantly in 2020. Our study provides methodologies to identify the key sources and regions of lake nutrient loading from watersheds with complex socioeconomic context, and to reveal the potential influences of socioeconomic development on nutrient pollution in lake watersheds.

Dual nitrate isotopes clarify the role of biological processing and hydrologic flow paths on nitrogen cycling in subtropical low-gradient watersheds

DOE PAGES

Griffiths, Natalie A.; Jackson, C. Rhett; McDonnell, Jeffrey J.; ...

2016-02-08

Nitrogen (N) is an important nutrient as it often limits productivity but in excess can impair water quality. Most studies on watershed N cycling have occurred in upland forested catchments where snowmelt dominates N export; fewer studies have focused on low-relief watersheds that lack snow. We examined watershed N cycling in three adjacent, low-relief watersheds in the Upper Coastal Plain of the southeastern United States to better understand the role of hydrological flow paths and biological transformations of N at the watershed scale. Groundwater was the dominant source of nitrified N to stream water in two of the three watersheds,more » while atmospheric deposition comprised 28% of stream water nitrate in one watershed. The greater atmospheric contribution may have been due to the larger stream channel area relative to total watershed area or the dominance of shallow subsurface flow paths contributing to stream flow in this watershed. There was a positive relationship between temperature and stream water ammonium concentrations and a negative relationship between temperature and stream water nitrate concentrations in each watershed suggesting that N cycling processes (i.e., nitrification and denitrification) varied seasonally. However, there were no clear patterns in the importance of denitrification in different water pools possibly because a variety of factors (i.e., assimilatory uptake, dissimilatory uptake, and mixing) affected nitrate concentrations. In conclusion, together, these results highlight the hydrological and biological controls on N cycling in low-gradient watersheds and variability in N delivery flow paths among adjacent watersheds with similar physical characteristics.« less

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

USGS Publications Warehouse

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

2013-01-01

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

A study of dissolved organic carbon and nitrate export in Catskill Mountain watersheds

NASA Astrophysics Data System (ADS)

Son, K.; Moore, K. E.; Lin, L.; Schneiderman, E. M.; Band, L. E.

2016-12-01

Watersheds in the Catskill Mountain region of New York State have historically experienced soil and stream acidification due to deposition of acidic compounds created from atmospheric SO2 and NOx. Recent studies in this region, and elsewhere in North America and Europe, have shown increases in dissolved organic carbon (DOC) in streams and lakes. Watersheds in the Catskills are the major source of drinking water for New York City and other communities in the region. Due to use of chlorine for disinfection, there is potential for the increase in DOC to lead to increased levels of disinfection byproducts in treated drinking water. Therefore, developing an improved understanding of the sources, fate and transport mechanisms, and export patterns for nitrate and DOC is important for informing watershed and water supply management. In this study, we analyzed the relationships between watershed characteristics, nitrate, and DOC for 12 gauged streams in the Neversink River watershed. Watershed characteristics included topography (elevation, slope, topographic wetness index), vegetation (leaf area index, species composition), soil (soil hydraulic parameters, soil carbon, wetland soil), atmospheric deposition (SO2, NOx), and climate (precipitation, temperature). Our preliminary analysis showed that both watershed slope and baseflow ratio are negatively correlated with annual median DOC concentration. At Biscuit Brook in the Neversink watershed, annual precipitation explained about 25% of annual DOC median concentration. DOC concentration was highly correlated with storm runoff in spring, summer, and fall, but stream nitrate concentration was weakly correlated with storm runoff in most seasons except summer when it was highly correlated with baseflow. We also applied a process-based ecohydrologic model (Regional Hydrologic Ecologic System Simulation, RHESSys) to the Biscuit Brook watershed to explore sources of nitrate and DOC and their movement within the watershed. We expect that this study will increase our understanding of how, when, and where DOC and nitrate are stored and transported to streams, as well as give insights into the key controls on nitrate and DOC processes in Catskill Mountain watersheds.

Distribution and Ecology of Campylobacters in Coastal Plain Streams (Georgia, United States of America)▿

PubMed Central

Vereen, Ethell; Lowrance, R. Richard; Cole, Dana J.; Lipp, Erin K.

2007-01-01

Campylobacter is the leading cause of bacterium-associated diarrhea in the United States and most developed countries. While this disease is considered a food-borne disease, many clinical cases cannot be linked to a food source. In rural and agrarian areas environmental transmission may be an important factor contributing to case loads. Here we investigated the waterborne prevalence of campylobacters in a mixed-use rural watershed in the coastal plain of southern Georgia (United States). Six sites representing various degrees of agricultural and human influence were surveyed biweekly to monthly for 1 year for the presence of culturable thermophilic campylobacters and other measures of water quality. Campylobacters were frequently present in agriculture- and sewage-impacted stretches of streams. The mean campylobacter counts and overall prevalence were highest downstream from a wastewater treatment plant that handled both human and poultry slaughterhouse waste (≤595 CFU ml−1; 100% positive); the concentrations were significantly higher than those for the four upstream sites (P < 0.05). The counts were significantly correlated with the number of fecal coliform bacteria, conductivity, pH, and concentrations of nutrients (NO3−, PO43−, and NH3). Campylobacters were isolated more frequently and larger numbers were present during the summer months, similar to the occurrence of clinical cases of campylobacteriosis in this region. A multivariate model showed that the levels were significantly influenced by increasing precipitation, which also peaked in the summer. The results indicate that loading from both human and domestic animal waste may be high in the watershed studied during the summer months. Mixed-use watersheds supporting agriculture production, human populations, and wildlife may be at risk for contamination by campylobacters and may be an important route for human exposure. PMID:17172457

Distribution and ecology of campylobacters in coastal plain streams (Georgia, United States of America).

PubMed

Vereen, Ethell; Lowrance, R Richard; Cole, Dana J; Lipp, Erin K

2007-03-01

Campylobacter is the leading cause of bacterium-associated diarrhea in the United States and most developed countries. While this disease is considered a food-borne disease, many clinical cases cannot be linked to a food source. In rural and agrarian areas environmental transmission may be an important factor contributing to case loads. Here we investigated the waterborne prevalence of campylobacters in a mixed-use rural watershed in the coastal plain of southern Georgia (United States). Six sites representing various degrees of agricultural and human influence were surveyed biweekly to monthly for 1 year for the presence of culturable thermophilic campylobacters and other measures of water quality. Campylobacters were frequently present in agriculture- and sewage-impacted stretches of streams. The mean campylobacter counts and overall prevalence were highest downstream from a wastewater treatment plant that handled both human and poultry slaughterhouse waste (

Gender sensitive education in watershed management to support environmental friendly city

NASA Astrophysics Data System (ADS)

Asteria, D.; Budidarmono; Herdiansyah, H.; Ni’mah, N. L.

2018-03-01

This study is about gender-sensitive perspective in watershed management education program as one of capacity building for citizens in watershed management with community-based strategy to support environmental friendly cities and security for women from flood disasters. Involving women and increasing women’s active participation in sustainable watershed management is essential in urban area. In global warming and climate change situations, city management should be integrated between social aspect and environmental planning. This study used mix method (concurrent embedded type, with quantitative as primary method) with research type is descriptive-explanatory. The result of this study is education strategies with gender approaches and affirmative action through emancipation approach and local knowledge from women’s experiences can increase women’s participation. Women’s empowerment efforts need integrated intervention and collaboration from government, NGO, and other stakeholders to optimize women’s role in watershed management for support environmental friendly city. The implication of this study is an educational strategy on watershed conservation with gender perspective to offer social engineering alternatives for decision makers to policy of sustainable watershed management in urban area related to flood mitigation efforts.

The Water Erosion Prediction Project (WEPP) model for saturation excess conditions: application to an agricultural and a forested watershed.

NASA Astrophysics Data System (ADS)

Crabtree, B.; Brooks, E.; Ostrowski, K.; Elliot, W. J.; Boll, J.

2006-12-01

We incorporated saturation excess overland flow processes in the Water Erosion Prediction Project (WEPP) model for the evaluation of human disturbances in watersheds. In this presentation, we present results of the modified WEPP model to two watersheds: an agricultural watershed with mixed land use, and a forested watershed. The agricultural watershed is Paradise Creek, an intensively monitored watershed with continuous climate, flow and sediment data collection at multiple locations. Restoration efforts in Paradise Creek watershed include changing to minimal tillage or no-tillage sytems, and implementation of structural practices. The forested watershed is the 28 km2 Mica Creek Experimental Watershed (MCEW) where disturbances include clear and partial cutting, and road building. The MCEW has a nested study design, which allows for the analysis of cumulative effects as well as the traditional comparison of treatment versus control. Mica Creek watershed is a high elevation watershed where streamflow is generated mostly by snowmelt. Treatments include road building in 1997, and clearcut and partial-cut logging in 2001. Our results include the simulation of streamflow and sediment delivery at multiple locations within each watershed, and evaluation of the human disturbances.

Interbasin groundwater flow and groundwater interaction with surface water in a lowland rainforest, Costa Rica: A review

NASA Astrophysics Data System (ADS)

Genereux, David P.; Jordan, Michael

2006-04-01

This paper reviews work related to interbasin groundwater flow (naturally occurring groundwater flow beneath watershed topographic divides) into lowland rainforest watersheds at La Selva Biological Station in Costa Rica. Chemical mixing calculations (based on dissolved chloride) have shown that up to half the water in some streams and up to 84% of the water in some riparian seeps and wells is due to high-solute interbasin groundwater flow (IGF). The contribution is even greater for major ions; IGF accounts for well over 90% of the major ions at these sites. Proportions are highly variable both among watersheds and with elevation within the same watershed (there is greater influence of IGF at lower elevations). The large proportion of IGF found in water in some riparian wetlands suggests that IGF is largely responsible for maintaining these wetlands. δ 18O data support the conclusions from the major ion data. Annual water and major ion budgets for two adjacent watersheds, one affected by IGF and the other not, showed that IGF accounted for two-thirds of the water input and 92-99% of the major ion input (depending on the major ion in question) to the former watershed. The large (in some cases, dominating) influence of IGF on watershed surface water quantity and quality has important implications for stream ecology and watershed management in this lowland rainforest. Because of its high phosphorus content, IGF increases a variety of ecological variables (algal growth rates, leaf decay rate, fungal biomass, invertebrate biomass, microbial respiration rates on leaves) in streams at La Selva. The significant rates of IGF at La Selva also suggest the importance of regional (as opposed to small-scale local) water resource planning that links lowland watersheds with regional groundwater. IGF is a relatively unexplored and potentially critical factor in the conservation of lowland rainforest.

Links between climate change, water-table depth, and water chemistry in a mineralized mountain watershed

USGS Publications Warehouse

Manning, Andrew H.; Verplanck, Philip L.; Caine, Jonathan S.; Todd, Andrew S.

2013-01-01

Recent studies suggest that climate change is causing rising solute concentrations in mountain lakes and streams. These changes may be more pronounced in mineralized watersheds due to the sensitivity of sulfide weathering to changes in subsurface oxygen transport. Specific causal mechanisms linking climate change and accelerated weathering rates have been proposed, but in general remain entirely hypothetical. For mineralized watersheds, a favored hypothesis is that falling water tables caused by declining recharge rates allow an increasing volume of sulfide-bearing rock to become exposed to air, thus oxygen. Here, we test the hypothesis that falling water tables are the primary cause of an increase in metals and SO4 (100-400%) observed since 1980 in the Upper Snake River (USR), Colorado. The USR drains an alpine watershed geologically and climatologically representative of many others in mineralized areas of the western U.S. Hydrologic and chemical data collected from 2005 to 2011 in a deep monitoring well (WP1) at the top of the USR watershed are utilized. During this period, both water table depths and groundwater SO4 concentrations have generally increased in the well. A numerical model was constructed using TOUGHREACT that simulates pyrite oxidation near WP1, including groundwater flow and oxygen transport in both saturated and unsaturated zones. The modeling suggests that a falling water table could produce an increase in metals and SO4 of a magnitude similar to that observed in the USR (up to 300%). Future water table declines may produce limited increases in sulfide weathering high in the watershed because of the water table dropping below the depth of oxygen penetration, but may continue to enhance sulfide weathering lower in the watershed where water tables are shallower. Advective air (oxygen) transport in the unsaturated zone caused by seasonally variable recharge and associated water table fluctuations was found to have little influence on pyrite oxidation rates near WP1. However, this mechanism could be important in the case of a shallow dynamic water table and more abundant/reactive sulfides in the shallow subsurface. Data from WP1 and numerical modeling results are thus consistent with the falling water table hypothesis, and illustrate fundamental processes linking climate and sulfide weathering in mineralized watersheds.

Interacting Watershed Size and Landcover Influences on Habitat and Biota of Lake Superior Coastal Wetlands

EPA Science Inventory

Coastal wetlands are important contributors to the productivity and biodiversity of large lakes and important mediators of the lake - watershed connection. This study explores how strength of connection to the watershed (represented by watershed size and wetland morphological ty...

Environmental values and attitudes among farmers in China – a case study in the watershed of Yuqiao reservoir of Tianjin Municipality, China

PubMed Central

Orderud, Geir Inge; Vogt, Rolf D.

2016-01-01

Failure to curb water pollution in China brings to the fore the issue of environmental values and attitudes among Chinese farmers. Applying the New Ecological Paradigm Scale this study finds that the pro-environmental value of New Ecological Paradigm (NEP) Worldview has a stronger standing among the studied Chinese farmers than the Dominant Social Paradigm (DSP) Worldview. PMID:27812223

An approach to study the effect of harvest and wildfire on watershed hydrology and sediment yield in a coast redwood forest

Treesearch

Christopher G. Surfleet; Arne Skaugset; Brian Dietterick

2012-01-01

The Little Creek watershed, within California State Polytechnic University’s Swanton Pacific Ranch, is the location of a paired and nested watershed study to investigate the watershed effects of coast redwood forest management. Streamflow, suspended sediment, and stream turbidity have been collected during storms at two locations on the North Fork Little Creek and at...

The challenge of documenting water quality benefits of conservation practices: a review of USDA-ARS's conservation effects assessment project watershed studies.

PubMed

Tomer, M D; Locke, M A

2011-01-01

The Conservation Effects Assessment Project was established to quantify water quality benefits of conservation practices supported by the U.S. Department of Agriculture (USDA). In 2004, watershed assessment studies were begun in fourteen agricultural watersheds with varying cropping systems, landscapes, climate, and water quality concerns. This paper reviews USDA Agricultural Research Service 'Benchmark' watershed studies and the challenge of identifying water quality benefits in watersheds. Study goals included modeling and field research to assess practices, and evaluation of practice placement in watersheds. Not all goals were met within five years but important lessons were learned. While practices improved water quality, problems persisted in larger watersheds. This dissociation between practice-focused and watershed-scale assessments occurred because: (1) Conservation practices were not targeted at critical sources/pathways of contaminants; (2) Sediment in streams originated more from channel and bank erosion than from soil erosion; (3) Timing lags, historical legacies, and shifting climate combined to mask effects of practice implementation; and (4) Water quality management strategies addressed single contaminants with little regard for trade-offs among contaminants. These lessons could help improve conservation strategies and set water quality goals with realistic timelines. Continued research on agricultural water quality could better integrate modeling and monitoring capabilities, and address ecosystem services.

Multi-Scale Soil Moisture Monitoring and Modeling at ARS Watersheds for NASA's Soil Moisture Active Passive (SMAP) Calibration/Validation Mission

NASA Astrophysics Data System (ADS)

Coopersmith, E. J.; Cosh, M. H.

2014-12-01

NASA's SMAP satellite, launched in November of 2014, produces estimates of average volumetric soil moisture at 3, 9, and 36-kilometer scales. The calibration and validation process of these estimates requires the generation of an identically-scaled soil moisture product from existing in-situ networks. This can be achieved via the integration of NLDAS precipitation data to perform calibration of models at each ­in-situ gauge. In turn, these models and the gauges' volumetric estimations are used to generate soil moisture estimates at a 500m scale throughout a given test watershed by leveraging, at each location, the gauge-calibrated models deemed most appropriate in terms of proximity, calibration efficacy, soil-textural similarity, and topography. Four ARS watersheds, located in Iowa, Oklahoma, Georgia, and Arizona are employed to demonstrate the utility of this approach. The South Fork watershed in Iowa represents the simplest case - the soil textures and topography are relative constants and the variability of soil moisture is simply tied to the spatial variability of precipitation. The Little Washita watershed in Oklahoma adds soil textural variability (but remains topographically simple), while the Little River watershed in Georgia incorporates topographic classification. Finally, the Walnut Gulch watershed in Arizona adds a dense precipitation network to be employed for even finer-scale modeling estimates. Results suggest RMSE values at or below the 4% volumetric standard adopted for the SMAP mission are attainable over the desired spatial scales via this integration of modeling efforts and existing in-situ networks.

EFFECTS OF WATERSHED DISTURBANCE ON SMALL STREAMS

EPA Science Inventory

This presentation presents the effects of watershed disturbance on small streams. The South Fork Broad River Watershed was studied to evaluate the use of landscape indicators to predict pollutant loading at small spatial scales and to develop indicators of pollutants. Also studie...

Evaluating Ecosystem Services Provided by the Albemarle-Pamlico (NC) Estuary System in Response to Watershed Nitrogen Management

EPA Science Inventory

The Albemarle-Pamlico Watershed and Estuary Study (APWES) is part of the USEPA Ecosystem Services Research Program. The mission of the APWES is to develop ecosystem services science to inform watershed and coastal management decisions in the Albemarle-Pamlico watershed and estuar...

Watershed and Economic Data InterOperability (WEDO): Facilitating Discovery, Evaluation and Integration through the Sharing of Watershed Modeling Data

EPA Science Inventory

Watershed and Economic Data InterOperability (WEDO) is a system of information technologies designed to publish watershed modeling studies for reuse. WEDO facilitates three aspects of interoperability: discovery, evaluation and integration of data. This increased level of interop...

Using global positioning system technology for watershed mapping in Caspar Creek

Treesearch

Norm Henry

1991-01-01

Surveying and mapping work has been an essential and time consuming part of the Caspar Watershed study during the North Fork phase. The cumulative effects study and several other studies being done in this phase require accurate mapping and periodic map updating of watershed features and disturbances.

Impacts of surface water diversions for marijuana cultivation on aquatic habitat in four northwestern California watersheds.

PubMed

Bauer, Scott; Olson, Jennifer; Cockrill, Adam; van Hattem, Michael; Miller, Linda; Tauzer, Margaret; Leppig, Gordon

2015-01-01

Marijuana (Cannabis sativa L.) cultivation has proliferated in northwestern California since at least the mid-1990s. The environmental impacts associated with marijuana cultivation appear substantial, yet have been difficult to quantify, in part because cultivation is clandestine and often occurs on private property. To evaluate the impacts of water diversions at a watershed scale, we interpreted high-resolution aerial imagery to estimate the number of marijuana plants being cultivated in four watersheds in northwestern California, USA. Low-altitude aircraft flights and search warrants executed with law enforcement at cultivation sites in the region helped to validate assumptions used in aerial imagery interpretation. We estimated the water demand of marijuana irrigation and the potential effects water diversions could have on stream flow in the study watersheds. Our results indicate that water demand for marijuana cultivation has the potential to divert substantial portions of streamflow in the study watersheds, with an estimated flow reduction of up to 23% of the annual seven-day low flow in the least impacted of the study watersheds. Estimates from the other study watersheds indicate that water demand for marijuana cultivation exceeds streamflow during the low-flow period. In the most impacted study watersheds, diminished streamflow is likely to have lethal or sub-lethal effects on state- and federally-listed salmon and steelhead trout and to cause further decline of sensitive amphibian species.

Impacts of Surface Water Diversions for Marijuana Cultivation on Aquatic Habitat in Four Northwestern California Watersheds

PubMed Central

Cockrill, Adam; van Hattem, Michael; Miller, Linda; Tauzer, Margaret; Leppig, Gordon

2015-01-01

Marijuana (Cannabis sativa L.) cultivation has proliferated in northwestern California since at least the mid-1990s. The environmental impacts associated with marijuana cultivation appear substantial, yet have been difficult to quantify, in part because cultivation is clandestine and often occurs on private property. To evaluate the impacts of water diversions at a watershed scale, we interpreted high-resolution aerial imagery to estimate the number of marijuana plants being cultivated in four watersheds in northwestern California, USA. Low-altitude aircraft flights and search warrants executed with law enforcement at cultivation sites in the region helped to validate assumptions used in aerial imagery interpretation. We estimated the water demand of marijuana irrigation and the potential effects water diversions could have on stream flow in the study watersheds. Our results indicate that water demand for marijuana cultivation has the potential to divert substantial portions of streamflow in the study watersheds, with an estimated flow reduction of up to 23% of the annual seven-day low flow in the least impacted of the study watersheds. Estimates from the other study watersheds indicate that water demand for marijuana cultivation exceeds streamflow during the low-flow period. In the most impacted study watersheds, diminished streamflow is likely to have lethal or sub-lethal effects on state-and federally-listed salmon and steelhead trout and to cause further decline of sensitive amphibian species. PMID:25785849

Technical Note: Determination of the SCS initial abstraction ratio in an experimental watershed in Greece

NASA Astrophysics Data System (ADS)

Baltas, E. A.; Dervos, N. A.; Mimikou, M. A.

2007-11-01

The present study was conducted in an experimental watershed in Attica, Greece, using observed rainfall/runoff events. The objective of the study was the determination of the initial abstraction ratio of the watershed. The average ratio (Ia/S) of the entire watershed was equal to 0.014. The corresponding ratio at a subwatershed was 0.037. The difference was attributed to the different spatial distribution of landuses and geological formations at the extent of the watershed. Both of the determined ratios are close to the ratio value of 0.05 that has been suggested from many studies for the improvement of the SCS-CN method.

Quantitative analysis and implications of drainage morphometry of the Agula watershed in the semi-arid northern Ethiopia

NASA Astrophysics Data System (ADS)

Fenta, Ayele Almaw; Yasuda, Hiroshi; Shimizu, Katsuyuki; Haregeweyn, Nigussie; Woldearegay, Kifle

2017-11-01

This study aimed at quantitative analysis of morphometric parameters of Agula watershed and its sub-watersheds using remote sensing data, geographic information system, and statistical methods. Morphometric parameters were evaluated from four perspectives: drainage network, watershed geometry, drainage texture, and relief characteristics. A sixth-order river drains Agula watershed and the drainage network is mainly dendritic type. The mean bifurcation ratio ( R b) was 4.46 and at sub-watershed scale, high R b values ( R b > 5) were observed which might be expected in regions of steeply sloping terrain. The longest flow path of Agula watershed is 48.5 km, with knickpoints along the main river which could be attributed to change of lithology and major faults which are common along the rift escarpments. The watershed has elongated shape suggesting low peak flows for longer duration and hence easier flood management. The drainage texture analysis revealed fine drainage which implies the dominance of impermeable soft rock with low resistance against erosion. High relief and steep slopes dominates, by which rough landforms (hills, breaks, and low mountains) make up 76% of the watershed. The S-shaped hypsometric curve with hypsometric integral of 0.4 suggests that Agula watershed is in equilibrium or mature stage of geomorphic evolution. At sub-watershed scale, the derived morphometric parameters were grouped into three clusters (low, moderate, and high) and considerable spatial variability was observed. The results of this study provide information on drainage morphometry that can help better understand the watershed characteristics and serve as a basis for improved planning, management, and decision making to ensure sustainable use of watershed resources.

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

PubMed

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

2013-09-01

Future shifts in climatic conditions may impact watershed mercury (Hg) dynamics and transport. An ensemble of watershed models was applied in the present study to simulate and evaluate the responses of hydrological and total Hg (THg) fluxes from the landscape to the watershed outlet and in-stream THg concentrations to contrasting climate change projections for a watershed in the southeastern coastal plain of the United States. Simulations were conducted under stationary atmospheric deposition and land cover conditions to explicitly evaluate the effect of projected precipitation and temperature on watershed Hg export (i.e., the flux of Hg at the watershed outlet). Based on downscaled inputs from 2 global circulation models that capture extremes of projected wet (Community Climate System Model, Ver 3 [CCSM3]) and dry (ECHAM4/HOPE-G [ECHO]) conditions for this region, watershed model simulation results suggest a decrease of approximately 19% in ensemble-averaged mean annual watershed THg fluxes using the ECHO climate-change model and an increase of approximately 5% in THg fluxes with the CCSM3 model. Ensemble-averaged mean annual ECHO in-stream THg concentrations increased 20%, while those of CCSM3 decreased by 9% between the baseline and projected simulation periods. Watershed model simulation results using both climate change models suggest that monthly watershed THg fluxes increase during the summer, when projected flow is higher than baseline conditions. The present study's multiple watershed model approach underscores the uncertainty associated with climate change response projections and their use in climate change management decisions. Thus, single-model predictions can be misleading, particularly in developmental stages of watershed Hg modeling. Copyright © 2013 SETAC.

Testing a two-scale focused conservation strategy for reducing phosphorus and sediment loads from agricultural watersheds

USGS Publications Warehouse

Carvin, Rebecca; Good, Laura W.; Fitzpatrick, Faith A.; Diehl, Curt; Songer, Katherine; Meyer, Kimberly J.; Panuska, John C.; Richter, Steve; Whalley, Kyle

2018-01-01

This study tested a focused strategy for reducing phosphorus (P) and sediment loads in agricultural streams. The strategy involved selecting small watersheds identified as likely to respond relatively quickly, and then focusing conservation practices on high-contributing fields within those watersheds. Two 5,000 ha (12,360 ac) watersheds in the Driftless Area of south central Wisconsin, previously ranked in the top 6% of similarly sized Wisconsin watersheds for expected responsiveness to conservation efforts to reduce high P and sediment loads, were chosen for the study. The stream outlets from both watersheds were monitored from October of 2006 through September of 2016 for streamflow and concentrations of sediment, total P, and, beginning in October of 2009, total dissolved P. Fields and pastures having the highest potential P delivery to the streams in each watershed were identified using the Wisconsin P Index (Good et al. 2012). After three years of baseline monitoring (2006 to 2009), farmers implemented both field- and farm-based conservation practices in one watershed (treatment) as a means to reduce sediment and P inputs to the stream from the highest contributing areas, whereas there were no out-of-the-ordinary conservation efforts in the second watershed (control). Implementation occurred primarily in 2011 and 2012. In the four years following implementation of conservation practices (2013 through 2016), there was a statistically significant reduction in storm-event suspended sediment loads in the treatment watershed compared to the control watershed when the ground was not frozen (p = 0.047). While there was an apparent reduction in year-round suspended sediment event loads, it was not statistically significant at the 95% confidence level (p = 0.15). Total P loads were significantly reduced for runoff events (p < 0.01) with a median reduction of 50%. Total P and total dissolved P concentrations for low-flow conditions were also significantly reduced (p < 0.01) compared to the control watershed. This study demonstrated that a strategy that first identifies watersheds likely to respond to conservation efforts and then focuses implementation on relatively high-contributing fields within those watersheds can be successful in reducing stream P concentrations and loads.

Assessment of freshwater withdrawals and availability for Marcellus shale natural gas development: a case study in Pennsylvania

Treesearch

Patrick C. Eisenhauer; Nicolas P. Zegre; Samuel J. Lamont

2013-01-01

To evaluate surface water withdrawals used for Marcellus shale natural gas development and to assess potential impacts on water yield, a regional water balance model was developed for the Pine Creek watershed, located primarily in Lycoming County, Pennsylvania. Marcellus shale development has increased rapidly in Lycoming County since 2007. We used precipitation,...

An aquatic multiscale assessment and planning framework approach—forest plan revision case study

Treesearch

Kerry Overton; Ann D. Carlson; Cynthia Tait

2010-01-01

The Aquatic Multiscale Assessment and Planning Framework is a Web-based decision-support tool developed to assist aquatic practitioners in managing fisheries and watershed information. This tool, or framework, was designed to assist resource assessments and planning efforts from the broad scale to the fine scale, to document procedures, and to link directly to relevant...

Detection of the Coupling between Vegetation Leaf Area and Climate in a Multifunctional Watershed, Northwestern China

Treesearch

Lu Hao; Cen Pan; Peilong Liu; Decheng Zhou; Liangxia Zhang; Zhe Xiong; Yongqiang Liu; Ge Sun

2016-01-01

Accurate detection and quantification of vegetation dynamics and drivers of observed climatic and anthropogenic change in space and time is fundamental for our understanding of the atmosphere–biosphere interactions at local and global scales. This case study examined the coupled spatial patterns of vegetation dynamics and climatic variabilities during the past...

Identification of Priority Forests in the Upper Mississippi River System: A Summary

Treesearch

Jason Rohweder; Theresa Heyer; Samuel Osinde; Darrell Zastrow; Steve Westin; Al Todd

2007-01-01

The goal of the Upper Mississippi Forest Partnership is to improve water quality and migratory bird habitat by restoring and enhancing forests in the six-state watershed. This document summarizes the results of a GIS analysis that identified forests where allocation of resources would make the most difference. Also included in this document are case studies that...

Water Resource Assessment, Gaps, and Constraints of Vegetable Production in Robit and Dangishta Watersheds, Upper Blue Nile Basin, Ethiopia

NASA Astrophysics Data System (ADS)

Worqlul, A. W.; Dile, Y.; Jeong, J.; Schmitter, P.; Bizimana, J. C.; Gerik, T.; Srinivasan, R.; Richardson, J. W.; Clarke, N.

2017-12-01

Rainfed agriculture supports the majority of the poor in sub-Saharan Africa. However, rainfall variability, land degradation and low soil fertility lessen their effectiveness for feeding the growing population. This study aims to estimate the water resources potential to sustain small-scale irrigation (SSI) in Ethiopia into the dry season to expand the food supply by growing vegetable and to understand the gaps and constraints of irrigated vegetable production. The case studies were located in Robit and Dangishta watersheds of the Ethiopian highlands near Lake Tana, where detailed field-level data were collected. The study focused on data from 18 households who have been cultivating tomato and onion during the dry season using irrigation in each watershed. The two components of the Integrated Decision Support System (IDSS) - the Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) - were used to assess impacts of SSI at multiple scales. Results suggest that there is a substantial amount of surface runoff and shallow groundwater recharge at watershed scale. The field-scale analysis within the Robit watershed indicated that optimal tomato yield could be obtained with 450 mm of irrigation and 200 to 250 kg/ha of urea with 50 kg/ha of diammonium phosphate (DAP). In Dangishta, optimum onion yield can be obtained by applying 550 mm irrigation and 120 to 180 kg/ha of urea with 50 kg/ha of DAP. Studying field scale water balance, the average shallow groundwater recharge (after accounting other groundwater users such as household and livestock uses) was not sufficient to meet tomato and onion water demand. The field-scale analysis also indicated that soil evaporation attributed a significant proportion of evapotranspiration (i.e. 60% of the evapotranspiration for onion and 40% for tomato). Use of mulching or other soil and water conservation interventions could increase water for cropping by reducing soil evaporation thereby enhancing the shallow groundwater. Integrated use of shallow groundwater and harvested surface runoff would reduce the negative environmental externalities.

Tire-wear particles as a source of zinc to the environment

USGS Publications Warehouse

Councell, T.B.; Duckenfield, K.U.; Landa, E.R.; Callender, E.

2004-01-01

Tire-tread material has a zinc (Zn) content of about 1 wt %. The quantity of tread material lost to road surfaces by abrasion has not been well characterized. Two approaches were used to assess the magnitude of this nonpoint source of Zn in the U.S. for the period 1936-1999. In the first approach, tread-wear rates from the automotive engineering literature were used in conjunction with vehicle distance-driven data from the U.S. Department of Transportation to determine Zn releases. A second approach calculated this source term from the volume of tread lost during lifetime tire wear. These analyses showed that the quantity of Zn released by tire wear in the mid-1990s was of the same magnitude as that released from waste incineration. For 1999, the quantity of Zn released by tire wear in the U.S. is estimated to be 10 000-11 000 metric tons. A specific case study focused on Zn sources and sinks in an urban-suburban watershed (Lake Anne) in the Washington, DC, metropolitan area for a time period of the late 1990s. The atmospheric flux of total Zn (wet deposition) to the watershed was 2 ??g/cm2/yr. The flux of Zn to the watershed estimated from tire wear was 42 ??g/cm2/yr. The measured accumulation rate of total Zn in age-dated sediment cores from Lake Anne was 27 ??g/cm2/yr. These data suggest that tire-wear Zn inputs to urban-suburban watersheds can be significantly greater than atmospheric inputs, although the watershed appears to retain appreciable quantities of vehicular Zn inputs.

Identifying sources and processes controlling the sulphur cycle in the Canyon Creek watershed, Alberta, Canada.

PubMed

Nightingale, Michael; Mayer, Bernhard

2012-01-01

Sources and processes affecting the sulphur cycle in the Canyon Creek watershed in Alberta (Canada) were investigated. The catchment is important for water supply and recreational activities and is also a source of oil and natural gas. Water was collected from 10 locations along an 8 km stretch of Canyon Creek including three so-called sulphur pools, followed by the chemical and isotopic analyses on water and its major dissolved species. The δ(2)H and δ(18)O values of the water plotted near the regional meteoric water line, indicating a meteoric origin of the water and no contribution from deeper formation waters. Calcium, magnesium and bicarbonate were the dominant ions in the upstream portion of the watershed, whereas sulphate was the dominant anion in the water from the three sulphur pools. The isotopic composition of sulphate (δ(34)S and δ(18)O) revealed three major sulphate sources with distinct isotopic compositions throughout the catchment: (1) a combination of sulphate from soils and sulphide oxidation in the bedrock in the upper reaches of Canyon Creek; (2) sulphide oxidation in pyrite-rich shales in the lower reaches of Canyon Creek and (3) dissolution of Devonian anhydrite constituting the major sulphate source for the three sulphur pools in the central portion of the watershed. The presence of H(2)S in the sulphur pools with δ(34)S values ∼30 ‰ lower than those of sulphate further indicated the occurrence of bacterial (dissimilatory) sulphate reduction. This case study reveals that δ(34)S values of surface water systems can vary by more than 20 ‰ over short geographic distances and that isotope analyses are an effective tool to identify sources and processes that govern the sulphur cycle in watersheds.

Using Wavelets to Evaluate Watershed Signals from Precipitation Extremes at a Localized Temporal Scale

NASA Astrophysics Data System (ADS)

Gentry, R. W.; Koirala, S. R.

2008-12-01

Resource managers in the future will be required to make decisions regarding complex systems under extreme uncertainty and to evaluate the sustainability of these natural systems. The variability and extremes of precipitation will be one of the major variables impacting natural systems, and decision making. These future decisions will be evaluated based upon economic costs and benefits, and core mission valuation. This will be particularly important in evaluating the effects and impacts of climate change on natural system response. In this case study, we evaluate the signal organization and its nature within a watershed in east Tennessee. In this study, temporal analyses were conducted on weekly time series data of water chemistry (nitrate, chloride, sulfate and calcium concentrations) collected from November 1995 to December 2005 at the West Fork of Walker Branch in Oak Ridge, Tennessee (Mulholland 1993, 2004). Hydrochemistry plays an important role in ecosystem services, particularly nitrate (Mulholland et al. 2008), and in general the signal responses can be complex. The time series in this study was modeled using a wavelet approach as a mechanism for evaluating short-term temporal effects. In general, time series signals of watershed hydrochemistry may provide clues as to broad environmental, ecological and economic impacts at the basin scale. References: Mulholland, P.J. (1993), Hydrometric and stream chemistry evidence of three storm flowpaths in Walker Branch Watershed, Journal of Hydrology, 151: 291-316. Mulholland, P.J. (2004). The importance of in-stream uptake for regulating stream concentrations and outputs of N and P from a forested watershed: evidence from long-term chemistry records for Walker Branch Watershed, Biogeochemistr. 70: 403-426. Mulholland, P.J., A.M. Helton, G.C. Poole, R.O. Hall Jr., S.K. Hamilton, B.J. Peterson, J.L. Tank, L.R. Ashkenas, L.W. Cooper, C.N. Dahm, W.K. Dodds, S.E.E. Findlay, S.V. Gregory, N.B. Grimm, S.L. Johnson, W.H. McDowell, J.L. Meyer, H.M. Valett, J.R. Webster, C.P. Arango, J.J. Beaulieu, M.J. Bernot, A.J. Burgin, C.L Crenshaw, L.T. Johnson, B.R. Niederlehner, J.M. O'Brien, J.D. Potter, R.W. Sheibley, D.J. Sobota, and S.M. Thomas (2008). Stream denitrification across biomes and its response to anthropogenic nitrate loading, Nature, 452(13): 202-206.

Occurrence of pesticides in five rivers of the Mississippi Embayment Study Unit, 1996-98

USGS Publications Warehouse

Coupe, Richard H.

2000-01-01

The occurrence and temporal distribution of more than 80 pesticides and pesticide metabolites were determined in five rivers of the Mississippi Embayment National Water-Quality Assessment study unit from February 1996 through January 1998. More than 230 samples were collected and analyzed during the 2-year study. The five rivers sampled included three rivers with small, primarily agricultural watersheds; one river with a small urban watershed in Memphis, Tennessee; and one large river with mixed land use (row-crop agriculture, pasture, forest, and urban). Pesticides, usually herbicides, were frequently detected in water samples from every river. Insecticides were frequently detected (chlorpyrifos and diazinon in all samples) only in the river that drains the urban watershed. The occurrence of pesticides in surface water varied among the agricultural watersheds as well as between the agricultural and urban watersheds. The pesticides detected in the rivers that drain the agricultural watersheds were related to the major crop types cultivated in the watershed?corn is mostly grown in the northern part of the study unit, whereas cotton and rice are mostly grown in the southern part. The occurrence of pesticides in the Yazoo River, which drains the mixed land-use watershed, was similar to pesticide occurrence in the rivers that drain smaller agricultural watersheds, although concentrations were lower in the Yazoo River. Likewise, simazine, which was detected in all urban stream samples, was also detected in all Yazoo River samples, but in lower concentrations. The aquatic-life criteria for diazinon and chlorpyrifos was exceeded in 24 of 25 and 12 of 25 urban river samples, respectively, but only once or twice in agricultural and mixed-use watershed samples. Atrazine exceeded the aquatic-life criterion in about 20 percent of the samples from each river, particularly in the spring following pesticide application.

Development of Load Duration Curve System in Data Scarce Watersheds Based on a Distributed Hydrological Model

NASA Astrophysics Data System (ADS)

WANG, J.

2017-12-01

In stream water quality control, the total maximum daily load (TMDL) program is very effective. However, the load duration curves (LDC) of TMDL are difficult to be established because no sufficient observed flow and pollutant data can be provided in data-scarce watersheds in which no hydrological stations or consecutively long-term hydrological data are available. Although the point sources or a non-point sources of pollutants can be clarified easily with the aid of LDC, where does the pollutant come from and to where it will be transported in the watershed cannot be traced by LDC. To seek out the best management practices (BMPs) of pollutants in a watershed, and to overcome the limitation of LDC, we proposed to develop LDC based on a distributed hydrological model of SWAT for the water quality management in data scarce river basins. In this study, firstly, the distributed hydrological model of SWAT was established with the scarce-hydrological data. Then, the long-term daily flows were generated with the established SWAT model and rainfall data from the adjacent weather station. Flow duration curves (FDC) was then developed with the aid of generated daily flows by SWAT model. Considering the goal of water quality management, LDC curves of different pollutants can be obtained based on the FDC. With the monitored water quality data and the LDC curves, the water quality problems caused by the point or non-point source pollutants in different seasons can be ascertained. Finally, the distributed hydrological model of SWAT was employed again to tracing the spatial distribution and the origination of the pollutants of coming from what kind of agricultural practices and/or other human activities. A case study was conducted in the Jian-jiang river, a tributary of Yangtze river, of Duyun city, Guizhou province. Results indicate that this kind of method can realize the water quality management based on TMDL and find out the suitable BMPs for reducing pollutant in a watershed.

Accounting for inter-annual and seasonal variability in regionalization of hydrologic response in the Great Lakes basin

NASA Astrophysics Data System (ADS)

Kult, J. M.; Fry, L. M.; Gronewold, A. D.

2012-12-01

Methods for predicting streamflow in areas with limited or nonexistent measures of hydrologic response typically invoke the concept of regionalization, whereby knowledge pertaining to gauged catchments is transferred to ungauged catchments. In this study, we identify watershed physical characteristics acting as primary drivers of hydrologic response throughout the US portion of the Great Lakes basin. Relationships between watershed physical characteristics and hydrologic response are generated from 166 catchments spanning a variety of climate, soil, land cover, and land form regimes through regression tree analysis, leading to a grouping of watersheds exhibiting similar hydrologic response characteristics. These groupings are then used to predict response in ungauged watersheds in an uncertainty framework. Results from this method are assessed alongside one historical regionalization approach which, while simple, has served as a cornerstone of Great Lakes regional hydrologic research for several decades. Our approach expands upon previous research by considering multiple temporal characterizations of hydrologic response. Due to the substantial inter-annual and seasonal variability in hydrologic response observed over the Great Lakes basin, results from the regression tree analysis differ considerably depending on the level of temporal aggregation used to define the response. Specifically, higher levels of temporal aggregation for the response metric (for example, indices derived from long-term means of climate and streamflow observations) lead to improved watershed groupings with lower within-group variance. However, this perceived improvement in model skill occurs at the cost of understated uncertainty when applying the regression to time series simulations or as a basis for model calibration. In such cases, our results indicate that predictions based on long-term characterizations of hydrologic response can produce misleading conclusions when applied at shorter time steps. This study suggests that measures of hydrologic response quantified at these shorter time steps may provide a more robust basis for making predictions in applications of water resource management, model calibration and simulations, and human health and safety.

Validation of SWAT+ at field level and comparison with previous SWAT models in simulating hydrologic quantity

NASA Astrophysics Data System (ADS)

GAO, J.; White, M. J.; Bieger, K.; Yen, H.; Arnold, J. G.

2017-12-01

Over the past 20 years, the Soil and Water Assessment Tool (SWAT) has been adopted by many researches to assess water quantity and quality in watersheds around the world. As the demand increases in facilitating model support, maintenance, and future development, the SWAT source code and data have undergone major modifications over the past few years. To make the model more flexible in terms of interactions of spatial units and processes occurring in watersheds, a completely revised version of SWAT (SWAT+) was developed to improve SWAT's ability in water resource modelling and management. There are only several applications of SWAT+ in large watersheds, however, no study pays attention to validate the new model at field level and assess its performance. To test the basic hydrologic function of SWAT+, it was implemented in five field cases across five states in the U.S. and compared the SWAT+ created results with that from the previous models at the same fields. Additionally, an automatic calibration tool was used to test which model is easier to be calibrated well in a limited number of parameter adjustments. The goal of the study was to evaluate the performance of SWAT+ in simulating stream flow on field level at different geographical locations. The results demonstrate that SWAT+ demonstrated similar performance with previous SWAT model, but the flexibility offered by SWAT+ via the connection of different spatial objects can result in a more accurate simulation of hydrological processes in spatial, especially for watershed with artificial facilities. Autocalibration shows that SWAT+ is much easier to obtain a satisfied result compared with the previous SWAT. Although many capabilities have already been enhanced in SWAT+, there exist inaccuracies in simulation. This insufficiency will be improved with advancements in scientific knowledge on hydrologic process in specific watersheds. Currently, SWAT+ is prerelease, and any errors are being addressed.

Streamflow chemistry and nutrient yields from upland-peatland watersheds in Minnesota

Treesearch

Elon S. Verry

1975-01-01

Twenty-two water quality parameters were determined for the streamflow from complex but typical upland-peatland watersheds over a period of 5 yr. Five watersheds with oligotrophic peatlands and one with a minerotrophic peatland were studied. Concentrations of organically derived nutrients are highest in the streamflow from watersheds containing oligotrophic peatlands;...

A Study on the Land Use Characteristics of Urban Medium and Small stream Depending on the Width of stream

NASA Astrophysics Data System (ADS)

Seok, Song Young; Ho, Song Yang; Ho, Lee Jung; Moo Jong, Park

2015-04-01

Due to the increase of impervious layers caused by increased rainfall and urbanization which were brought about by the climate change after the late 1990s, the flood damage in urban watersheds is rising. The recent flood damage is occurring in medium and small stream rather than in large stream. Particularly, in medium stream which pass the cities, sudden flood occurs due to the short concentration of rainfall and urban areas suffer large damage, even though the flood damage is small, since residential areas and social infrastructures are concentrated. In spite of the importance of medium and small stream to pass the cities, there is no certain standard for classification of natural or urban stream and existing studies are mostly focused on the impervious area among the land use characteristics of watersheds. Most of existing river studies are based on the watershed scale, but in most urban watersheds where stream pass, urban areas are concentrated in the confluence, so urban areas only occupy less than 10% of the whole watershed and there is a high uncertainty in the classification of urban areas, based the watershed of stream. This study aims to suggest a classification standard of medium and small stream between local stream and small stream where suffer flood damage. According to the classified medium and small stream, this study analyzed the stream area to the stream width and distance using Arcgis Buffer tool, based on the stream line, not the existing watershed scale. This study then chose urban watersheds by analyzing the river area at certain intervals from the center of the chosen medium and small stream, in different ways. Among the land use characteristics in urban areas, the impervious area was applied to the selection standard of urban watersheds and the characteristics of urban watersheds were presented by calculating the ratio of the stream area to the impervious area using the Buffer tool. Acknowledgement "This research was supported by a grant [NEMA-NH-2011-45] from the Natural Hazard Mitigation Research Group, National Emergency Management Agency of Korea." Keywords: land use, urban watershed, medium and smaill stream, impervious area

Development of watershed models for emerald lake watershed in Sequoia National Park and for other lakes of the Sierra Nevada. Final report

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

Sorooshian, S.; Bales, R.C.; Gupta, V.K.

1992-02-01

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 secondmore » 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.« less

Linking plot, field, and watershed runoff and water quality in Goodwater Creek Experimental Watershed

USDA-ARS?s Scientific Manuscript database

Most water quality studies are conducted at the plot, field, or watershed scale; however, studies that integrate the three scales provide information to scale results obtained at one scale to a greater area. The objective of this study was to analyze runoff and water quality measured (1997-2001) fr...

The Shenandoah Watershed Study: 20 years of Catchment Hydrogeochemistry

NASA Astrophysics Data System (ADS)

Galloway, J.

2002-05-01

The Shenandoah Watershed Study (SWAS) is a cooperative program between the Department of Environmental Sciences at the University of Virginia and the National Park Service. The scientific objective of the SWAS program is to improve understanding of processes and factors that govern hydrobiogeochemical conditions in forested watersheds of the Shenandoah National Park (SNP), VA, and the central Appalachian Mountain region. The SWAS program was initiated in 1979, with the establishment of water quality monitoring on two streams. The current SWAS network involves 14 primary study watersheds, in which a combination of discharge gauging, quarterly and weekly water quality sampling, and episodic storm-flow sampling take place. In addition, a number of extensive water quality surveys, fish population surveys, soil surveys, vegetation surveys, and plot-scale manipulations have been conducted in the SWAS watersheds in support of basic research in watershed science. The SWAS program is presently coordinated with the Virginia Trout Stream Sensitivity Study (VTSSS), which extends the watershed-based research to an additional 51 native brook trout streams located on public lands throughout western Virginia. During the past two decades the SWAS program has developed a uniquely comprehensive watershed database for SNP resource managers, while making major contributions to scientific understanding of surface water acidification and the biogeochemistry of forested mountain watersheds. The SWAS program is characterized by long-term continuity of sampling, a wide range of temporal resolution, and the availability of data from multiple watersheds within the landscape. These attributes enable both detection of long-term trends in response to chronic anthropogenic influences (e.g., acidic deposition) and interpretation of transient natural disturbances (e.g., pest outbreaks, fire, etc.). The spatial redundancy of the network provides insight into the regional homogeneity of observed changes and understanding of landscape controls (especially geologic setting) on watershed processes. This poster will present an overview of the critical findings of this 20-year research program.

Urban sprawl leaves its PAH signature

USGS Publications Warehouse

Van Metre, P.C.; Mahler, B.J.; Furlong, E.T.

2000-01-01

The increasing vehicle traffic associated with urban sprawl in the United States is frequently linked to degradation of air quality, but its effect on aquatic sediment is less well-recognized. This study evaluates trends in PAHs, a group of contaminants with multiple urban sources, in sediment cores from 10 reservoirs and lakes in six U.S. metropolitan areas. The watersheds chosen represent a range in degree and age of urbanization. Concentrations of PAHs in all 10 reservoirs and lakes increased during the past 20-40 years. PAH contamination of the most recently deposited sediment at all sites exceeded sediment-quality guidelines established by Environment Canada, in some cases by several orders of magnitude. These results add a new chapter to the story told by previous coring studies that reported decreasing concentrations of PAHs after reaching highs in the 1950s. Concurrent with the increase in concentrations is a change in the assemblage of PAHs that indicates the increasing trends are driven by combustion sources. The increase in PAH concentrations tracks closely with increases in automobile use, even in watersheds that have not undergone substantial changes in urban land-use levels since the 1970s.The increasing vehicle traffic associated with urban sprawl in the United States is frequently linked to degradation of air quality, but its effect on aquatic sediment is less well-recognized. This study evaluates trends in PAHs, a group of contaminants with multiple urban sources, in sediment cores from 10 reservoirs and lakes in six U.S. metropolitan areas. The watersheds chosen represent a range in degree and age of urbanization. Concentrations of PAHs in all 10 reservoirs and lakes increased during the past 20-40 years. PAH contamination of the most recently deposited sediment at all sites exceeded sediment-quality guidelines established by Environment Canada, in some cases by several orders of magnitude. These results add a new chapter to the story told by previous coring studies that reported decreasing concentrations of PAHs after reaching highs in the 1950s. Concurrent with the increase in concentrations is a change in the assemblage of PAHs that indicates the increasing trends are driven by combustion sources. The increase in PAH concentrations tracks closely with increases in automobile use, even in watersheds that have not undergone substantial changes in urban land-use levels since the 1970s.

The study of soils and vegetation transformation due fire disturbances in remote areas through scenario modelling of observed hydrological response to fire impact

NASA Astrophysics Data System (ADS)

Nesterova, Natalia; Semenova, Olga; Lebedeva, Luidmila

2015-04-01

Large territories of Siberia and Russian Far East are the subject to frequent forest fires. Often there is no information available about fire impact except its timing, areal distribution and qualitative characteristics of fire severity. Observed changes of hydrological response in burnt watersheds can be considered as indirect evidence of soil and vegetation transformation due to fire impact. In our study we used MODIS Fire products to detect spatial distribution of fires in Transbaikal and Far East regions of Russia in 2000 - 2012 period. Small and middle-size watersheds (with area up to 10000 km2) affected by extensive (burn area not less than 20 %) fires were chosen. We analyzed available hydrological data (measured discharges in watersheds outlets) for chosen basins. In several cases apparent hydrological response to fire was detected. To investigate main factors causing the change of hydrologic regime after fire several scenarios of soil and vegetation transformation were developed for each watershed under consideration. Corresponding sets of hydrological model parameters describing those transformations were elaborated based on data analysis and post-fire landscape changes as derived from a literature review. We implied different factors such as removal of organic layer, albedo changes, intensification of soil thaw (in presence of permafrost and seasonal soil freezing), reduction of infiltration rate and evapotranspiration, increase of upper subsurface flow fraction in summer flood events following the fire and others. We applied Hydrograph model (Russia) to conduct simulation experiments aiming to reveal which landscape changes scenarios were more plausible. The advantages of chosen hydrological model for this study are 1) that it takes into consideration thermal processes in soils which in case of permafrost and seasonal soil freezing presence can play leading role in runoff formation and 2) that observable vegetation and soil properties are used as its parameters allowing minimal resort to calibration. The model can use dynamic set of parameters performing preassigned abrupt and/or gradual changes of landscape characteristics. Interestingly, based on modelling results it can be concluded that depending on dominant landscape different aspects of soil and vegetation cover changes may influence runoff formation in contrasting way. The results of the study will be reported.

Variability in runoff fluxes of dissolved and particulate carbon and nitrogen from two watersheds of different tree species during intense storm events

NASA Astrophysics Data System (ADS)

Lee, Mi-Hee; Payeur-Poirier, Jean-Lionel; Park, Ji-Hyung; Matzner, Egbert

2016-09-01

Heavy storm events may increase the amount of organic matter in runoff from forested watersheds as well as the relation of dissolved to particulate organic matter. This study evaluated the effects of monsoon storm events on the runoff fluxes and on the composition of dissolved (< 0.45 µm) and particulate (0.7 µm to 1 mm) organic carbon and nitrogen (DOC, DON, POC, PON) in a mixed coniferous/deciduous (mixed watershed) and a deciduous forested watershed (deciduous watershed) in South Korea. During storm events, DOC concentrations in runoff increased with discharge, while DON concentrations remained almost constant. DOC, DON and NO3-N fluxes in runoff increased linearly with discharge pointing to changing flow paths from deeper to upper soil layers at high discharge, whereas nonlinear responses of POC and PON fluxes were observed likely due to the origin of particulate matter from the erosion of mineral soil along the stream benches. The integrated C and N fluxes in runoff over the 2-month study period were in the order of DOC > POC and NO3-N > DON > PON. The integrated DOC fluxes in runoff during the study period were much larger at the deciduous watershed (16 kg C ha-1) than at the mixed watershed (7 kg C ha-1), while the integrated NO3-N fluxes were higher at the mixed watershed (5.2 kg N ha-1) than at the deciduous watershed (2.9 kg N ha-1). The latter suggests a larger N uptake by deciduous trees. Integrated fluxes of POC and PON were similar at both watersheds. The composition of organic matter in soils and runoff indicates that the contribution of near-surface flow to runoff was larger at the deciduous than at the mixed watershed. Our results demonstrate different responses of particulate and dissolved C and N in runoff to storm events as a combined effect of tree species composition and watershed specific flow paths.

Twenty years of water-quality studies in the Cheney Reservoir Watershed, Kansas, 1996-2016

USGS Publications Warehouse

Graham, Jennifer L.; Foster, Guy M.; Kramer, Ariele R.

2017-03-31

Since 1996, the U.S. Geological Survey (USGS), in cooperation with the City of Wichita, has done studies in the Cheney Reservoir watershed to understand environmental effects on water-quality conditions. Early studies (1996–2001) determined subwatershed sources of contaminants, nutrient and sediment loading to Cheney Reservoir, changes in reservoir sediment quality over time, and watershed sources of phosphorus. Later studies (2001–present) focused on nutrient and sediment concentrations and mass transport from the watershed; the presence of cyanobacteria, cyanotoxins, and taste-and-odor compounds in the reservoir; and development of regression models for real-time computations of water-quality constituents of interest that may affect drinking-water treatment. This fact sheet summarizes key results from studies done by the USGS during 1996–2016 in the Cheney Reservoir watershed and Cheney Reservoir.

BMP analysis system for watershed-based stormwater management.

PubMed

Zhen, Jenny; Shoemaker, Leslie; Riverson, John; Alvi, Khalid; Cheng, Mow-Soung

2006-01-01

Best Management Practices (BMPs) are measures for mitigating nonpoint source (NPS) pollution caused mainly by stormwater runoff. Established urban and newly developing areas must develop cost effective means for restoring or minimizing impacts, and planning future growth. Prince George's County in Maryland, USA, a fast-growing region in the Washington, DC metropolitan area, has developed a number of tools to support analysis and decision making for stormwater management planning and design at the watershed level. These tools support watershed analysis, innovative BMPs, and optimization. Application of these tools can help achieve environmental goals and lead to significant cost savings. This project includes software development that utilizes GIS information and technology, integrates BMP processes simulation models, and applies system optimization techniques for BMP planning and selection. The system employs the ESRI ArcGIS as the platform, and provides GIS-based visualization and support for developing networks including sequences of land uses, BMPs, and stream reaches. The system also provides interfaces for BMP placement, BMP attribute data input, and decision optimization management. The system includes a stand-alone BMP simulation and evaluation module, which complements both research and regulatory nonpoint source control assessment efforts, and allows flexibility in the examining various BMP design alternatives. Process based simulation of BMPs provides a technique that is sensitive to local climate and rainfall patterns. The system incorporates a meta-heuristic optimization technique to find the most cost-effective BMP placement and implementation plan given a control target, or a fixed cost. A case study is presented to demonstrate the application of the Prince George's County system. The case study involves a highly urbanized area in the Anacostia River (a tributary to Potomac River) watershed southeast of Washington, DC. An innovative system of management practices is proposed to minimize runoff, improve water quality, and provide water reuse opportunities. Proposed management techniques include bioretention, green roof, and rooftop runoff collection (rain barrel) systems. The modeling system was used to identify the most cost-effective combinations of management practices to help minimize frequency and size of runoff events and resulting combined sewer overflows to the Anacostia River.

Assessment and Reduction of Model Parametric Uncertainties: A Case Study with A Distributed Hydrological Model

NASA Astrophysics Data System (ADS)

Gan, Y.; Liang, X. Z.; Duan, Q.; Xu, J.; Zhao, P.; Hong, Y.

2017-12-01

The uncertainties associated with the parameters of a hydrological model need to be quantified and reduced for it to be useful for operational hydrological forecasting and decision support. An uncertainty quantification framework is presented to facilitate practical assessment and reduction of model parametric uncertainties. A case study, using the distributed hydrological model CREST for daily streamflow simulation during the period 2008-2010 over ten watershed, was used to demonstrate the performance of this new framework. Model behaviors across watersheds were analyzed by a two-stage stepwise sensitivity analysis procedure, using LH-OAT method for screening out insensitive parameters, followed by MARS-based Sobol' sensitivity indices for quantifying each parameter's contribution to the response variance due to its first-order and higher-order effects. Pareto optimal sets of the influential parameters were then found by the adaptive surrogate-based multi-objective optimization procedure, using MARS model for approximating the parameter-response relationship and SCE-UA algorithm for searching the optimal parameter sets of the adaptively updated surrogate model. The final optimal parameter sets were validated against the daily streamflow simulation of the same watersheds during the period 2011-2012. The stepwise sensitivity analysis procedure efficiently reduced the number of parameters that need to be calibrated from twelve to seven, which helps to limit the dimensionality of calibration problem and serves to enhance the efficiency of parameter calibration. The adaptive MARS-based multi-objective calibration exercise provided satisfactory solutions to the reproduction of the observed streamflow for all watersheds. The final optimal solutions showed significant improvement when compared to the default solutions, with about 65-90% reduction in 1-NSE and 60-95% reduction in |RB|. The validation exercise indicated a large improvement in model performance with about 40-85% reduction in 1-NSE, and 35-90% reduction in |RB|. Overall, this uncertainty quantification framework is robust, effective and efficient for parametric uncertainty analysis, the results of which provide useful information that helps to understand the model behaviors and improve the model simulations.

Relation of watershed setting and stream nutrient yields at selected sites in central and eastern North Carolina, 1997-2008

USGS Publications Warehouse

Harden, Stephen L.; Cuffney, Thomas F.; Terziotti, Silvia; Kolb, Katharine R.

2013-01-01

Data collected between 1997 and 2008 at 48 stream sites were used to characterize relations between watershed settings and stream nutrient yields throughout central and eastern North Carolina. The focus of the investigation was to identify environmental variables in watersheds that influence nutrient export for supporting the development and prioritization of management strategies for restoring nutrient-impaired streams. Nutrient concentration data and streamflow data compiled for the 1997 to 2008 study period were used to compute stream yields of nitrate, total nitrogen (N), and total phosphorus (P) for each study site. Compiled environmental data (including variables for land cover, hydrologic soil groups, base-flow index, streams, wastewater treatment facilities, and concentrated animal feeding operations) were used to characterize the watershed settings for the study sites. Data for the environmental variables were analyzed in combination with the stream nutrient yields to explore relations based on watershed characteristics and to evaluate whether particular variables were useful indicators of watersheds having relatively higher or lower potential for exporting nutrients. Data evaluations included an examination of median annual nutrient yields based on a watershed land-use classification scheme developed as part of the study. An initial examination of the data indicated that the highest median annual nutrient yields occurred at both agricultural and urban sites, especially for urban sites having large percentages of point-source flow contributions to the streams. The results of statistical testing identified significant differences in annual nutrient yields when sites were analyzed on the basis of watershed land-use category. When statistical differences in median annual yields were noted, the results for nitrate, total N, and total P were similar in that highly urbanized watersheds (greater than 30 percent developed land use) and (or) watersheds with greater than 10 percent point-source flow contributions to streamflow had higher yields relative to undeveloped watersheds (having less than 10 and 15 percent developed and agricultural land uses, respectively) and watersheds with relatively low agricultural land use (between 15 and 30 percent). The statistical tests further indicated that the median annual yields for total P were statistically higher for watersheds with high agricultural land use (greater than 30 percent) compared to the undeveloped watersheds and watersheds with low agricultural land use. The total P yields also were higher for watersheds with low urban land use (between 10 and 30 percent developed land) compared to the undeveloped watersheds. The study data indicate that grouping and examining stream nutrient yields based on the land-use classifications used in this report can be useful for characterizing relations between watershed settings and nutrient yields in streams located throughout central and eastern North Carolina. Compiled study data also were analyzed with four regression tree models as a means of determining which watershed environmental variables or combination of variables result in basins that are likely to have high or low nutrient yields. The regression tree analyses indicated that some of the environmental variables examined in this study were useful for predicting yields of nitrate, total N, and total P. When the median annual nutrient yields for all 48 sites were evaluated as a group (Model 1), annual point-source flow yields had the greatest influence on nitrate and total N yields observed in streams, and annual streamflow yields had the greatest influence on yields of total P. The Model 1 results indicated that watersheds with higher annual point-source flow yields had higher annual yields of nitrate and total N, and watersheds with higher annual streamflow yields had higher annual yields of total P. When sites with high point-source flows (greater than 10 percent of total streamflow) were excluded from the regression tree analyses (Models 2–4), the percentage of forested land in the watersheds was identified as the primary environmental variable influencing stream yields for both total N and total P. Models 2, 3 and 4 did not identify any watershed environmental variables that could adequately explain the observed variability in the nitrate yields among the set of sites examined by each of these models. The results for Models 2, 3, and 4 indicated that watersheds with higher percentages of forested land had lower annual total N and total P yields compared to watersheds with lower percentages of forested land, which had higher median annual total N and total P yields. Additional environmental variables determined to further influence the stream nutrient yields included median annual percentage of point-source flow contributions to the streams, variables of land cover (percentage of forested land, agricultural land, and (or) forested land plus wetlands) in the watershed and (or) in the stream buffer, and drainage area. The regression tree models can serve as a tool for relating differences in select watershed attributes to differences in stream yields of nitrate, total N, and total P, which can provide beneficial information for improving nutrient management in streams throughout North Carolina and for reducing nutrient loads to coastal waters.

On the Scaling Behavior of Reliability-Resilience-Vulnerability ...

EPA Pesticide Factsheets

Risk indices such as reliability-resilience-vulnerability (R-R-V) have been proposed to assess watershed health. In this study, the spatial scaling behavior of R-R-V indices has been explored for five agricultural watersheds in the midwestern United States. The study was conducted using two different measures of spatial scale: (i) the ratio of contributing upland area to area required for channel initiation (FA), and (ii) Strahler stream order. It was found that R-R-V indices do change with spatial scale, but a representative watershed-specific threshold FA value exists for these indices to achieve stable values. Scaling with Strahler stream order is feasible if the watershed possesses a tree-like stream network. As an example of anthropogenic influences, this study also examined the role of BMPs placed within an agricultural watershed via a cost-effective optimization scheme on the evolution of R-R-V values with scale. While the placement of BMPs acheived reductions in concentrations and/or loads of constituents, they may not significantly change watershed risk measures, but are likely to cause significant reduction in vulnerability. If primarily upland BMPs are placed in a diffuse manner throughout the watershed, there might not be a significant change in the scaling behavior of R-R-V values. The primary objective of this study is to investigate the effect of spatial scale on risk-based watershed health assessment. A related objective is to examine wh

Trend analysis of watershed-scale precipitation over Northern California by means of dynamically-downscaled CMIP5 future climate projections.

PubMed

Ishida, K; Gorguner, M; Ercan, A; Trinh, T; Kavvas, M L

2017-08-15

The impacts of climate change on watershed-scale precipitation through the 21st century were investigated over eight study watersheds in Northern California based on dynamically downscaled CMIP5 future climate projections from three GCMs (CCSM4, HadGEM2-ES, and MIROC5) under the RCP4.5 and RCP8.5 future climate scenarios. After evaluating the modeling capability of the WRF model, the six future climate projections were dynamically downscaled by means of the WRF model over Northern California at 9km grid resolution and hourly temporal resolution during a 94-year period (2006-2100). The biases in the model simulations were corrected, and basin-average precipitation over the eight study watersheds was calculated from the dynamically downscaled precipitation data. Based on the dynamically downscaled basin-average precipitation, trends in annual depth and annual peaks of basin-average precipitation during the 21st century were analyzed over the eight study watersheds. The analyses in this study indicate that there may be differences between trends of annual depths and annual peaks of watershed-scale precipitation during the 21st century. Furthermore, trends in watershed-scale precipitation under future climate conditions may be different for different watersheds depending on their location and topography even if they are in the same region. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluating robustness in rank-based risk assessments of freshwater ecosystems

USGS Publications Warehouse

Mattson, K.M.; Angermeier, Paul

2007-01-01

Conservation planning aims to protect biodiversity by sustainng the natural physical, chemical, and biological processes within representative ecosystems. Often data to measure these components are inadequate or unavailable. The impact of human activities on ecosystem processes complicates integrity assessments and might alter ecosystem organization at multiple spatial scales. Freshwater conservation targets, such as populations and communities, are influenced by both intrinsic aquatic properties and the surrounding landscape, and locally collected data might not accurately reflect potential impacts. We suggest that changes in five major biotic drivers—energy sources, physical habitat, flow regime, water quality, and biotic interactions—might be used as surrogates to inform conservation planners of the ecological integrity of freshwater ecosystems. Threats to freshwater systems might be evaluated based on their impact to these drivers to provide an overview of potential risk to conservation targets. We developed a risk-based protocol, the Ecological Risk Index (ERI), to identify watersheds with least/most risk to conservation targets. Our protocol combines risk-based components, specifically the frequency and severity of human-induced stressors, with biotic drivers and mappable land- and water-use data to provide a summary of relative risk to watersheds. We illustrate application of our protocol with a case study of the upper Tennessee River basin, USA. Differences in risk patterns among the major drainages in the basin reflect dominant land uses, such as mining and agriculture. A principal components analysis showed that localized, moderately severe threats accounted for most of the threat composition differences among our watersheds. We also found that the relative importance of threats is sensitive to the spatial grain of the analysis. Our case study demonstrates that the ERI is useful for evaluating the frequency and severity of ecosystemwide risk, which can inform local and regional conservation planning.

Nutrient export from watersheds on Mt. Desert Island, maine, as a function of land use and fire history

USGS Publications Warehouse

Nielsen, M.G.; Kahl, J.S.

2007-01-01

A study of 13 small (less than 7.5 km2) watersheds on Mt. Desert Island, Maine, was conducted from January 1999 to September 2000 to determine nutrient export delivery to coastal waters around the island, and to determine whether a series of wildfires in 1947 have affected nutrient export in burned watersheds. Nutrient export (nitrate-nitrogen, total nitrogen, total phosphorus) was determined for each watershed during the study period, and was normalized by watershed area. The yield of nitrate-nitrogen (N) ranged from 10 to 140 kg/km2/year. Total N yield ranged from 42 to 250 kg/ km2/year. Total phosphorus (P) yield ranged from 1.4 to 7.9 kg/km2/year. Watersheds entirely within Acadia National Park (lacking human land-based nutrient sources) exported significantly less total N and total P than watersheds that were partly or entirely outside the park boundary. Nitrate-N export was not significantly different in these two groups of watersheds, perhaps because atmospheric deposition is a dominant source of nitrate in the study area. No relation was observed between burn history and nutrient export. Any effect of burn history may be masked by other landscape-level factors related to nutrient export. ?? Springer Science + Business Media B.V. 2007.

Advancing computational methods for calibration of the Soil and Water Assessment Tool (SWAT): Application for modeling climate change impacts on water resources in the Upper Neuse Watershed of North Carolina

NASA Astrophysics Data System (ADS)

Ercan, Mehmet Bulent

Watershed-scale hydrologic models are used for a variety of applications from flood prediction, to drought analysis, to water quality assessments. A particular challenge in applying these models is calibration of the model parameters, many of which are difficult to measure at the watershed-scale. A primary goal of this dissertation is to contribute new computational methods and tools for calibration of watershed-scale hydrologic models and the Soil and Water Assessment Tool (SWAT) model, in particular. SWAT is a physically-based, watershed-scale hydrologic model developed to predict the impact of land management practices on water quality and quantity. The dissertation follows a manuscript format meaning it is comprised of three separate but interrelated research studies. The first two research studies focus on SWAT model calibration, and the third research study presents an application of the new calibration methods and tools to study climate change impacts on water resources in the Upper Neuse Watershed of North Carolina using SWAT. The objective of the first two studies is to overcome computational challenges associated with calibration of SWAT models. The first study evaluates a parallel SWAT calibration tool built using the Windows Azure cloud environment and a parallel version of the Dynamically Dimensioned Search (DDS) calibration method modified to run in Azure. The calibration tool was tested for six model scenarios constructed using three watersheds of increasing size (the Eno, Upper Neuse, and Neuse) for both a 2 year and 10 year simulation duration. Leveraging the cloud as an on demand computing resource allowed for a significantly reduced calibration time such that calibration of the Neuse watershed went from taking 207 hours on a personal computer to only 3.4 hours using 256 cores in the Azure cloud. The second study aims at increasing SWAT model calibration efficiency by creating an open source, multi-objective calibration tool using the Non-Dominated Sorting Genetic Algorithm II (NSGA-II). This tool was demonstrated through an application for the Upper Neuse Watershed in North Carolina, USA. The objective functions used for the calibration were Nash-Sutcliffe (E) and Percent Bias (PB), and the objective sites were the Flat, Little, and Eno watershed outlets. The results show that the use of multi-objective calibration algorithms for SWAT calibration improved model performance especially in terms of minimizing PB compared to the single objective model calibration. The third study builds upon the first two studies by leveraging the new calibration methods and tools to study future climate impacts on the Upper Neuse watershed. Statistically downscaled outputs from eight Global Circulation Models (GCMs) were used for both low and high emission scenarios to drive a well calibrated SWAT model of the Upper Neuse watershed. The objective of the study was to understand the potential hydrologic response of the watershed, which serves as a public water supply for the growing Research Triangle Park region of North Carolina, under projected climate change scenarios. The future climate change scenarios, in general, indicate an increase in precipitation and temperature for the watershed in coming decades. The SWAT simulations using the future climate scenarios, in general, suggest an increase in soil water and water yield, and a decrease in evapotranspiration within the Upper Neuse watershed. In summary, this dissertation advances the field of watershed-scale hydrologic modeling by (i) providing some of the first work to apply cloud computing for the computationally-demanding task of model calibration; (ii) providing a new, open source library that can be used by SWAT modelers to perform multi-objective calibration of their models; and (iii) advancing understanding of climate change impacts on water resources for an important watershed in the Research Triangle Park region of North Carolina. The third study leveraged the methodological advances presented in the first two studies. Therefore, the dissertation contains three independent by interrelated studies that collectively advance the field of watershed-scale hydrologic modeling and analysis.

Prioritising watersheds on the basis of regional flood susceptibility and vulnerability in mountainous areas through the use of indicators

NASA Astrophysics Data System (ADS)

Rogelis, Carolina; Werner, Micha

2013-04-01

Settlements in peri-urban areas of many cities in mountainous areas such as in the Andes are susceptible to hazards such as flash floods and debris flows. Additionally these settlements are in many cases informal and thus vulnerable to such hazards, resulting in significant risk. Such watersheds are often quiet small, and generally there is little or no information from gauges to help characterise risk. To help identify watersheds in which flood management measures are to be targeted, a rapid assessment of risk is required. In this paper a novel approach is presented where indicators of susceptibility and vulnerability to flash floods were used to prioritize 106 mountain watersheds in Bogotá (Colombia). Variables recognized in literature to determine the dominant processes both in susceptibility and vulnerability to flash floods were used to construct the indicators. Susceptibility was considered to increase with flashiness and the possibility of debris flow events occurring. This was assessed through the use of an indicator composed of a morphometric indicator and a land use indicator. The former was constructed using morphological variables recognized in literature to significantly influence flashiness and occurrence of debris flows; the latter was constructed in terms of percentage of vegetation cover, urban area and bare soil. The morphometric indicator was compared with the results of a debris flow propagation algorithm to assess its capacity in indentifying the morphological conditions of a watershed that make it able to transport debris flows. Propagation was carried out through the use of the Modified Single Flow Direction algorithm, following previous identification of source areas by applying thresholds identified in the area-slope curve of the watersheds and empirical thresholds. Results show that the morphometric variables can be grouped in four categories: size, shape, hypsometry and energy, with the energy the component found to best explain the capability of the watershed to transport debris flows. The combination of the morphometric and land use indicators resulted in a susceptibility indicator that was compared with the available records of past floods in the area. This showed that the use of the land use indicator significantly improves the susceptibility assessment. Vulnerability was assessed in terms of indicators representing physical exposure, fragility of the socio-economic system and lack of resilience to cope and recover. Principal component analysis was subsequently applied to reduce variables and provide a representation of each of their facets by a component. This resulted in a composite indicator of susceptibility and vulnerability for each of the 106 watersheds. The indicator was compared with the history of flash flood damage in the watersheds. Results show that the indicator is useful in applications at regional scales for preliminary assessment to differentiate at spatial level the degree of flood susceptibility and vulnerability. This provides an initial and qualitative risk outlook in the study area and can be used for planning and prioritization of further more detailed studies.

Environmental setting of Maple Creek watershed, Nebraska

USGS Publications Warehouse

Fredrick, Brian S.; Linard, Joshua I.; Carpenter, Jennifer L.

2006-01-01

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.

River Sediment Monitoring Using Remote Sensing and GIS (case Study Karaj Watershed)

NASA Astrophysics Data System (ADS)

Shafaie, M.; Ghodosi, H.; Mostofi, K. H.

2015-12-01

Whereas the tank volume and dehydrating digits from kinds of tanks are depended on repository sludge, so calculating the sediments is so important in tank planning and hydraulic structures. We are worry a lot about soil erosion in the basin area leading to deposit in rivers and lakes. It holds two reasons: firstly, because the surface soil of drainage would lose its fertility and secondly, the capacity of the tank decreases also it causes the decrease of water quality in downstream. Several studies have shown that we can estimate the rate of suspension sediments through remote sensing techniques. Whereas using remote sensing methods in contrast to the traditional and current techniques is faster and more accurate then they can be used as the effective techniques. The intent of this study has already been to estimate the rate of sediments in Karaj watershed through remote sensing and satellite images then comparing the gained results to the sediments data to use them in gauge-hydraulic station. We mean to recognize the remote sensing methods in calculating sediment and use them to determine the rate of river sediments so that identifying their accuracies. According to the results gained of the shown relations at this article, the amount of annual suspended sedimentary in KARAJ watershed have been 320490 Tones and in hydrologic method is about 350764 Tones .

Whole-system phosphorus balances as a practical tool for lake management

Treesearch

Johanna Schussler; Lawrence A. Baker; Hugh Chester-Jones

2007-01-01

Controlling phosphorus (P) inputs to lakes remains a priority of lake management. This study develops watershed P balances for 11 recreational lakes in Minnesota. Areal P input rates to the watersheds ranged from 0.32 to 6.0 kg Pha-1 year-1 and was linearly related to the percentage of watershed in agriculture. Watershed P...

Phosphorus export across an urban to rural gradient in the Chesapeake Bay watershed

Treesearch

Shuiwang Duan; Sujay S. Kaushal; Peter Groffman; Lawrence E. Band; Kenneth Belt

2012-01-01

Watershed export of phosphorus (P) from anthropogenic sources has contributed to eutrophication in freshwater and coastal ecosystems. We explore impacts of watershed urbanization on the magnitude and export flow distribution of P along an urban-rural gradient in eight watersheds monitored as part of the Baltimore Ecosystem Study Long-Term Ecological Research site....

Timber markets and marketing in the Monocacy River watershed of Maryland and Pennsylvania

Treesearch

George E. Doverspike; James C. Rettie; Harry W., Jr. Camp

1951-01-01

The Maryland Department of State Forests and Parks, cooperating with the locally organized Monocacy River Watershed Council, has requested the Northeastern Forest Experiment Station to undertake a study of the forest resource of that watershed. The objective is to provide information that will be helpful in conserving watershed values and in promoting better management...

Sulfometuron Methyl Dissipation in Southern Forest

Treesearch

J.L. Michael; D.G. Neary

1988-01-01

This study evaluated dissipation of the herbicide sulfometuron methyl [OUST (R)], in water in forest watersheds of the southern United States. Oust was aerially applied as a spray to a 445 ha watershed, and as the pellet formulation to a 247 ha watershed in Mississippi in April, 1985. The same treatments were applied in Florida, but to 4 ha watersheds by...

Logging impacts of the 1970's vs. the 1990's in the Caspar Creek watershed

Treesearch

Peter H. Cafferata; Thomas E. Spittler

1998-01-01

The Caspar Creek watershed study provides resource professionals with information regarding the impacts of timber operations conducted under varying forest practices on sensitive aquatic habitats. In the South Fork watershed, roads were constructed near watercourse channels in the 1960's, and the watershed was selectively logged using tractors during the early...

Impacts of social indicators on assessing the recovery potential of impaired watersheds.

PubMed

Sinshaw, Tadesse A; Surbeck, Cristiane Q

2018-05-09

An analysis was carried out to understand how watersheds' potential for restoration was impacted by social indicators. This study employed the USEPA Recovery Potential Screening tool, a decision support system, to compare 51 watersheds in the state of Mississippi, USA, using ecological, stressor, and social indices, and the recovery potential integrated (RPI) index. An in-depth analysis was performed on four watersheds in the Delta region of Mississippi (Lake Washington, Harris Bayou, Steele Bayou, and Coldwater River), each impaired by sediments and nutrients. Sixteen social indicators were categorized into three subcategories: Socio-Economic, Organizational, and Informational. Watersheds with lower social indices had lower RPI scores. In the particular watersheds studied, the Socio-Economic subcategory was observed to be the most impactful to the overall recovery potential when compared to the other two social subcategories. As a sensitivity analysis, a "what if" simulation was performed to explore alternatives to upgrade a watershed's social index and, consequently, the relative recovery potential of the watershed to a target level. This analysis is useful for understanding how particular social indicators of a community impact the relative potential for recovering a watershed, beyond just the ecological and stressor conditions. It also sheds light on assessing which social indicators can be improved. Copyright © 2018 Elsevier Ltd. All rights reserved.

On the Scaling Behavior of Reliability-Resilience-Vulnerability Indices in Agricultural Watersheds

EPA Science Inventory

Risk indices such as reliability-resilience-vulnerability (R-R-V) have been proposed to assess watershed health. In this study, the spatial scaling behavior of R-R-V indices has been explored for five agricultural watersheds in the midwestern United States. The study was conduc...

Hydrologic calibration of paired watersheds using a MOSUM approach

Treesearch

H. Ssegane; Devendra Amatya; A. Muwamba; G. M. Chescheir; T. Appelboom; E. W. Tollner; J. E. Nettles; M. A. Youssef; F. Birgand; R. W. Skaggs

2015-01-01

Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment) during the calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the...

Watershed modeling applications in south Texas

USGS Publications Warehouse

Pedraza, Diana E.; Ockerman, Darwin J.

2012-01-01

This fact sheet presents an overview of six selected watershed modeling studies by the USGS and partners that address a variety of water-resource issues in south Texas. These studies provide examples of modeling applications and demonstrate the usefulness and versatility of watershed models in aiding the understanding of hydrologic systems.

Mapping Land Use/Land Cover in the Ambos Nogales Study Area

USGS Publications Warehouse

Norman, Laura M.; Wallace, Cynthia S.A.

2008-01-01

The Ambos Nogales watershed, which surrounds the twin cities of Nogales, Arizona, United States and Nogales, Sonora, Mexico, has a history of problems related to flooding. This paper describes the process of creating a high-resolution, binational land-cover dataset to be used in modeling the Ambos Nogales watershed. The Automated Geospatial Watershed Assessment tool will be used to model the Ambos Nogales watershed to identify focal points for planning efforts and to anticipate ramifications of implementing detention reservoirs at certain watershed planes.

A System Method for the Assessment of Integrated Water Resources Management (IWRM) in Mountain Watershed Areas: The Case of the "Giffre" Watershed (France)

NASA Astrophysics Data System (ADS)

Charnay, Bérengère

2011-07-01

In the last fifty years, many mountain watersheds in temperate countries have known a progressive change from self-standing agro-silvo-pastoral systems to leisure dominated areas characterized by a concentration of tourist accommodations, leading to a drinking water peak during the winter tourist season, when the water level is lowest in rivers and sources. The concentration of water uses increases the pressure on "aquatic habitats" and competition between uses themselves. Consequently, a new concept was developed following the international conferences in Dublin (International Conference on Water and the Environment - ICWE) and Rio de Janeiro (UN Conference on Environment and Development), both in 1992, and was broadly acknowledged through international and European policies. It is the concept of Integrated Water Resource Management ( IWRM). It meets the requirements of different uses of water and aquatic zones whilst preserving the natural functions of such areas and ensuring a satisfactory economic and social development. This paper seeks to evaluate a local water resources management system in order to implement it using IWRM in mountain watersheds. The assessment method is based on the systemic approach to take into account all components influencing a water resources management system at the watershed scale. A geographic information system was built to look into interactions between water resources, land uses, and water uses. This paper deals specifically with a spatial comparison between hydrologically sensitive areas and land uses. The method is applied to a French Alps watershed: the Giffre watershed (a tributary of the Arve in Haute-Savoie). The results emphasize both the needs and the gaps in implementing IWRM in vulnerable mountain regions.

Using causal loop diagrams for the initialization of stakeholder engagement in soil salinity management in agricultural watersheds in developing countries: a case study in the Rechna Doab watershed, Pakistan.

PubMed

Inam, Azhar; Adamowski, Jan; Halbe, Johannes; Prasher, Shiv

2015-04-01

Over the course of the last twenty years, participatory modeling has increasingly been advocated as an integral component of integrated, adaptive, and collaborative water resources management. However, issues of high cost, time, and expertise are significant hurdles to the widespread adoption of participatory modeling in many developing countries. In this study, a step-wise method to initialize the involvement of key stakeholders in the development of qualitative system dynamics models (i.e. causal loop diagrams) is presented. The proposed approach is designed to overcome the challenges of low expertise, time and financial resources that have hampered previous participatory modeling efforts in developing countries. The methodological framework was applied in a case study of soil salinity management in the Rechna Doab region of Pakistan, with a focus on the application of qualitative modeling through stakeholder-built causal loop diagrams to address soil salinity problems in the basin. Individual causal loop diagrams were developed by key stakeholder groups, following which an overall group causal loop diagram of the entire system was built based on the individual causal loop diagrams to form a holistic qualitative model of the whole system. The case study demonstrates the usefulness of the proposed approach, based on using causal loop diagrams in initiating stakeholder involvement in the participatory model building process. In addition, the results point to social-economic aspects of soil salinity that have not been considered by other modeling studies to date. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of Fire on Streamflow in Southern California Watersheds

NASA Astrophysics Data System (ADS)

Bart, R. R.; Hope, A. S.

2007-12-01

Post-fire streamflow dynamics in Southern California have primarily been studied using small watershed experiments. These studies have concluded that increases in streamflow are a consequence of an increase in soil hydrophobicity, along with a decrease in transpiration rates associated with less vegetation. Extrapolation of the results from these studies to large watersheds (>50 km2) has been limited because large watersheds may not burn completely and other processes may emerge at these scales. In this study, six paired watersheds were used to test the hypothesis that there is an increase in streamflow following fire in large California watersheds (54-632 km2). The percentage of area burned in these watersheds ranged from 23 to 100%. The effects of fires on streamflow were examined at annual, seasonal, and monthly time-steps for the five years following fire. In addition, this study attempted to address fundamental regression assumptions that are commonly ignored, and create uncertainty bounds for evaluating the changes in streamflow before and after fire. Results of this experiment indicate that differences in pre and post-fire streamflows, at all time scales and in all the test catchments, were generally within the 95% uncertainty bounds of the regression equation. It is uncertain whether the apparent lack of significant difference between the pre and post-fire streamflow reflects no actual change in streamflow or is a consequence of the errors and uncertainties in the streamflow data. Furthermore, persistent drought in the years following fire made it challenging to interpret differences in pre and post-fire flows using the paired watershed methodology. The effects of hydrophobicity on post-fire streamflow may have been reduced by a limited number of storm flow events during these drought years. Under these dry conditions, soil moisture was the dominant control over transpirational losses, minimizing the effects of a reduction in vegetation cover. These results indicate that the consequences of fires are likely to vary depending on the post-fire meteorological conditions. The study addresses the challenges of using non-experimental watersheds for paired watershed studies.

Sediment transport to and from small impoundments in northeast Kansas, March 2009 through September 2011

USGS Publications Warehouse

Foster, Guy M.; Lee, Casey J.; Ziegler, Andrew C.

2012-01-01

The U.S. Geological Survey, in cooperation with the Kansas Water Office, investigated sediment transport to and from three small impoundments (average surface area of 0.1 to 0.8 square miles) in northeast Kansas during March 2009 through September 2011. Streamgages and continuous turbidity sensors were operated upstream and downstream from Atchison County, Banner Creek, and Centralia Lakes to study the effect of varied watershed characteristics and agricultural practices on sediment transport in small watersheds in northeast Kansas. Atchison County Lake is located in a predominantly agricultural basin of row crops, with wide riparian buffers along streams, a substantial amount of tile drainage, and numerous small impoundments (less than 0.05 square miles; hereafter referred to as “ponds”). Banner Creek Lake is a predominantly grassland basin with numerous small ponds located in the watershed, and wide riparian buffers along streams. Centralia Lake is a predominantly agricultural basin of row crops with few ponds, few riparian buffers along streams, and minimal tile drainage. Upstream from Atchison County, Banner Creek, and Centralia Lakes 24, 38, and 32 percent, respectively, of the total load was transported during less than 0.1 percent (approximately 0.9 days) of the time. Despite less streamflow in 2011, larger sediment loads during that year indicate that not all storm events transport the same amount of sediment; larger, extreme storms during the spring may transport much larger sediment loads in small Kansas watersheds. Annual sediment yields were 360, 400, and 970 tons per square mile per year at Atchison County, Banner, and Centralia Lake watersheds, respectively, which were less than estimated yields for this area of Kansas (between 2,000 and 5,000 tons per square mile per year). Although Centralia and Atchison County Lakes had similar percentages of agricultural land use, mean annual sediment yields upstream from Centralia Lake were about 2.7 times those at Atchison County or Banner Creek Lakes. These data indicate larger yields of sediment from watersheds with row crops and those with fewer small ponds, and smaller yields in watersheds which are primarily grassland, or agricultural with substantial tile drainage and riparian buffers along streams. These results also indicated that a cultivated watershed can produce yields similar to those observed under the assumed reference (or natural) condition. Selected small ponds were studied in the Atchison County Lake watershed to characterize the role of small ponds in sediment trapping. Studied ponds trapped about 8 percent of the sediment upstream from the sediment-sampling site. When these results were extrapolated to the other ponds in the watershed, differences in the extent of these ponds was not the primary factor affecting differences in yields among the three watersheds. However, the selected small ponds were both 45 years old at the time of this study, and have reduced capacity because of being filled in with sediments. Additionally, trapping efficiency of these small ponds decreased over five observed storms, indicating that processes that suspended or resuspended sediments in these shallow ponds, such as wind and waves, affected their trapping efficiencies. While small ponds trapped sediments in small storms, they could be a source of sediment in larger or more closely spaced storm events. Channel slope was similar at all three watersheds, 0.40, 0.46, and 0.31 percent at Atchison County, Banner Creek, and Centralia Lake watersheds, respectively. Other factors, such as increased bank and stream erosion, differences in tile drainage, extent of grassland, or riparian buffers, could be the predominant factors affecting sediment yields from these basins. These results show that reference-like sediment yields may be observed in heavily agricultural watersheds through a combination of field-scale management activities and stream channel protection. When computing loads using published erosion rates obtained by single-point survey methodology, streambank contributions from the main stem of Banner Creek are three times more than the sediment load observed by this study at the sediment sampling site at Banner Creek, 2.6 times more than the sediment load observed by this study at the sediment sampling site at Clear Creek (upstream from Atchison County Lake), and are 22 percent of the load observed by this study at the sediment sampling site at Black Vermillion River above Centralia Lake. Comparisons of study sites to similarly sized urban and urbanizing watersheds in Johnson County, Kansas indicated that sediment yields from the Centralia Lake watershed were similar to those in construction-affected watersheds, while much smaller sediment yields in the Atchison County and Banner Creek watersheds were comparable to stable, heavily urbanized watersheds. Comparisons of study sites to larger watersheds upstream from Tuttle Creek Lake indicate the Black Vermillion River watershed continues to have high sediment yields despite 98 percent of sediment from the Centralia watershed (a headwater of the Black Vermillion River) being trapped in Centralia Lake. Estimated trapping efficiencies for the larger watershed lakes indicated that Banner Creek and Centralia Lakes trapped 98 percent of incoming sediment, whereas Atchison County Lake trapped 72 percent of incoming sediment during the 3-year study period.

Projecting supply and demand of hydrologic ecosystem services under future climate conditions

NASA Astrophysics Data System (ADS)

Chiang, Li-Chi; Huang, Tao; Lee, Tsung-Yu

2014-05-01

Ecosystems provide essential goods and services, such as food, clean water, water purification, soil conservation and cultural services for human being. In a watershed, these water-related ecosystem goods and services can directly or indirectly benefit both local people and downstream beneficiaries through a reservoir. Water quality and quantity in a reservoir are of importance for agricultural, industrial and domestic uses. Under the impacts of climate and land use changes, both ecosystem service supply and demand will be affected by changes in precipitation patterns, temperature, urbanization and agricultural activities. However, the linkage between ecosystem service provisioning (ESP) and ecosystem service beneficiary (ESB), and scales of supply and demand of ecosystem services are not clear yet. Therefore, to investigate water-related ecosystem service supply under climate and land use change, we took the Xindian river watershed (303 km2) as a case study, where the Feitsui Reservoir provides hydro-power and daily domestic water use of 3,450,000 m3 for 3.46 million people in Taipei, Taiwan. We integrated a hydrological model (Soil and Water Assessment Tool, SWAT) and a land use change model (Conversion of Land Use and its Effects, CLUE-s) with future climate change scenarios derived from General Circulation Models (GCMs), to assess the changes in ecosystem service supply and demand at different hydrologic scales. The results will provide useful information for decision-making on future land use management and climate change adaptation strategies in the watersheds. Keywords: climate change, land use change, ecosystem service, watershed, scale

Application of risk-based multiple criteria decision analysis for selection of the best agricultural scenario for effective watershed management.

PubMed

Javidi Sabbaghian, Reza; Zarghami, Mahdi; Nejadhashemi, A Pouyan; Sharifi, Mohammad Bagher; Herman, Matthew R; Daneshvar, Fariborz

2016-03-01

Effective watershed management requires the evaluation of agricultural best management practice (BMP) scenarios which carefully consider the relevant environmental, economic, and social criteria involved. In the Multiple Criteria Decision-Making (MCDM) process, scenarios are first evaluated and then ranked to determine the most desirable outcome for the particular watershed. The main challenge of this process is the accurate identification of the best solution for the watershed in question, despite the various risk attitudes presented by the associated decision-makers (DMs). This paper introduces a novel approach for implementation of the MCDM process based on a comparative neutral risk/risk-based decision analysis, which results in the selection of the most desirable scenario for use in the entire watershed. At the sub-basin level, each scenario includes multiple BMPs with scores that have been calculated using the criteria derived from two cases of neutral risk and risk-based decision-making. The simple additive weighting (SAW) operator is applied for use in neutral risk decision-making, while the ordered weighted averaging (OWA) and induced OWA (IOWA) operators are effective for risk-based decision-making. At the watershed level, the BMP scores of the sub-basins are aggregated to calculate each scenarios' combined goodness measurements; the most desirable scenario for the entire watershed is then selected based on the combined goodness measurements. Our final results illustrate the type of operator and risk attitudes needed to satisfy the relevant criteria within the number of sub-basins, and how they ultimately affect the final ranking of the given scenarios. The methodology proposed here has been successfully applied to the Honeyoey Creek-Pine Creek watershed in Michigan, USA to evaluate various BMP scenarios and determine the best solution for both the stakeholders and the overall stream health. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ecosystem resistance in the face of climate change: A case study from the freshwater marshes of the Florida Everglades

Treesearch

Sparkle L. Malone; Cynthia Keough; Christina L. Staudhammer; Michael G. Ryan; William J. Parton; Paulo Olivas; Steven F. Oberbauer; Jessica Schedlbauer; Gregory Starr

2015-01-01

Shaped by the hydrology of the Kissimmee-Okeechobee-Everglades watershed, the Florida Everglades is composed of a conglomerate of wetland ecosystems that have varying capacities to sequester and store carbon. Hydrology, which is a product of the region’s precipitation and temperature patterns combined with water management policy, drives community composition...

Integrated modeling of water supply and demand under management options and climate change scenarios in Chifeng City, China

Treesearch

Lu Hao; Ge Sun; Yongqiang Liu; Hong Qian

2015-01-01

Water resource management is becoming increasingly challenging in northern China because of the rapid increase in water demand and decline in water supply due to climate change. We provide a case study demonstrating the importance of integrated watershed management in sustaining water resources in Chifeng City, northern China. We examine the consequences of various...

Effect of Strip Mining on Water Quality in Small Streams in Eastern Kentucky, 1967-1975

Treesearch

Kenneth L. Dyer; Willie R. Curtis

1977-01-01

Eight years of streamflow data are analyzed to show the effects of strip mining on chemical quality of water in six first-order streams in Breathitt County, Kentucky. All these watersheds were unmined in August, 1967, but five have since been strip mined. The accumulated data from this case history study indicate that strip mining causes large increases in the...

Watershed erosion modeling using the probability of sediment connectivity in a gently rolling system

NASA Astrophysics Data System (ADS)

Mahoney, David Tyler; Fox, James Forrest; Al Aamery, Nabil

2018-06-01

Sediment connectivity has been shown in recent years to explain how the watershed configuration controls sediment transport. However, we find no studies develop a watershed erosion modeling framework based on sediment connectivity, and few, if any, studies have quantified sediment connectivity for gently rolling systems. We develop a new predictive sediment connectivity model that relies on the intersecting probabilities for sediment supply, detachment, transport, and buffers to sediment transport, which is integrated in a watershed erosion model framework. The model predicts sediment flux temporally and spatially across a watershed using field reconnaissance results, a high-resolution digital elevation models, a hydrologic model, and shear-based erosion formulae. Model results validate the capability of the model to predict erosion pathways causing sediment connectivity. More notably, disconnectivity dominates the gently rolling watershed across all morphologic levels of the uplands, including, microtopography from low energy undulating surfaces across the landscape, swales and gullies only active in the highest events, karst sinkholes that disconnect drainage areas, and floodplains that de-couple the hillslopes from the stream corridor. Results show that sediment connectivity is predicted for about 2% or more the watershed's area 37 days of the year, with the remaining days showing very little or no connectivity. Only 12.8 ± 0.7% of the gently rolling watershed shows sediment connectivity on the wettest day of the study year. Results also highlight the importance of urban/suburban sediment pathways in gently rolling watersheds, and dynamic and longitudinal distributions of sediment connectivity might be further investigated in future work. We suggest the method herein provides the modeler with an added tool to account for sediment transport criteria and has the potential to reduce computational costs in watershed erosion modeling.

Priority and construction sites of water storage in a watershed in response to climate change

NASA Astrophysics Data System (ADS)

Lin, Cheng-Yu; Zhang, Wen-Yan; Lin, Chao-Yuan

2014-05-01

Taiwan is located at the Eastern Asia Monsoon climate zone. Typhoons and/or convectional rains occur frequently and result in high intensity storms in the summer season. Once the detention facilities are shortage or soil infiltration rate become worse in a watershed due to land use, surface runoff is easily to concentrate and threaten the protected areas. Therefore, it is very important to examine the functionality of water storage for a watershed. The purpose of this study is to solve the issue of flooding in the Puzi Creek. A case study of Yizen Bridge Watershed, in which the SCS curve number was used as an index to extract the spatial distribution of the strength of water storage, and the value of watershed mean CN along the main channel was calculated using area-weighting method. Therefore, the hotspot management sites were then derived and the priority method was applied to screen the depression sites for the reference of management authorities in detention ponds placement. The results show that the areas of subzone A with the characteristics of bad condition in topography and soil, which results in poor infiltration. However, the areas are mostly covered with forest and are difficult to create the artificial water storage facilities. Detention dams are strongly recommended at the site of depression in the river channel to decrease discharge velocity and reduce impact from flood disaster. The areas of subzone B are mainly located at the agriculture slope land. The topographic depressions in the farmland are the suitable places to construct the farm ponds for the use of flood detention and sediment deposition in the rainy seasons and irrigation in the dry seasons. Areas of subzone C are mainly occupied the gentle slope land with a better ability in water storage due to low CN value. Farm ponds constructed in the riparian to bypass the nearby river channel can create multifunctional wetland to effectively decrease the peak discharge in the downstream during storm events. Depression storages are based on additional runoff obtained from CN calculation. Strategies mentioned in this study can be provided as references of climate change adaptions for related authorities.

Spatial characteristics of topography, energy exchange, and forest cover in a central Appalachian watershed

Treesearch

Stanislaw J. Tajchman; Hailiang Fu; James N. Kochenderfer; Pan Chunshen

1995-01-01

Spatial variation of topography, net radiation, evapotranspiration, and forest stand in the central Appalachian watershed is described. The study area is the control watershed 4 (39"20'N, 79"49"W) located in the Fernow Experimental Forest at Parsons, West Virginia. The watershed encompasses an area of 39.2 ha, it has a southeast orientation, and the...

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

USGS Publications Warehouse

Ranalli, Anthony J.; Macalady, Donald L.

2010-01-01

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

Development and implementation of a watershed management plan forLlac la Biche, Alberta, Canada.

PubMed

White, J; Logan, M; Rawles, M

2006-01-01

Lakeland County is experiencing increasing developmental pressures arising from the oil and gas boom at nearby Fort McMurray. There is increased industrial traffic passing through the county, and 600 new residential lots are proposed in 2005, almost double from 5 years ago. Deteriorating surface water quality has been a concern in the area due to an increase in development and agriculture, while excessive fish harvesting and winterkills have impacted commercial and recreational fisheries. Today, walleye and pike populations in the lake remain collapsed and restocking efforts have not been successful. Due to the lack of studies done on the watershed, the county is leading a multidisciplinary research study which includes a baseline water quality study, riparian health assessments, land use mapping and ground-truthing and projects with the local health authority. This research has been summarized in a comprehensive state of the watershed report, which will be used to complete a watershed management plan for the Lac la Biche watershed. Recommendations from the state of the watershed report and watershed management plan will also be incorporated into municipal planning documents and recommend changes to the Municipal Government Act itself.

Hydrology and water budget for a forested atlantic coastal plain watershed, South Carolina

Treesearch

Scott V. Harder; Devendra M Amatya; Callahan Timothy J.; Carl C. Trettin; Hakkila Jon

2007-01-01

Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

Cascabel prescribed fire long-term watershed study: an opportunity to monitor climate change

Treesearch

Gerald Gottfried; Daniel Neary; Peter Ffolliott; Karen Koestner

2012-01-01

Experimental watershed studies can provide answers to new challenges facing land managers and society including the impacts of fires and climate change on upstream and regional hydrology. The Cascabel Watersheds long-term prescribed fire study provides a unique opportunity to monitor climate change because of its location in an oak savanna situated between deserts or...

Caspar Creek Watershed Study--North Fork Phase, Jackson Demonstration State Forest, Status and Plans, 1983-1990

Treesearch

Norm Henry; Karen Sendek

1985-01-01

Abstract - The California Department of Forestry and U.S. Forest Service, Pacific Southwest Forest and Range Experiment Station have been conducting a paired watershed study on Jackson Demonstration State Forest for 24 years. The South Fork watershed phase of the study involved monitoring the impacts of road construction (1967) and selective tractor logging (1971-1973...

Hyrdology and water budget for a forested atlantic coastal plain watershed, South Carolina

Treesearch

Scott V. Harder; Devendra M. Amatya; Timothy J. Callahan; Carl C. Trettin; Jon Hakkila

2007-01-01

Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

Timber harvest and logging plan for the South Fork of the Caspar Creek watershed

Treesearch

Anonymous

1970-01-01

The Caspar Creek Watershed Study was initiated in 1960 to study large differences between conditions of stream flow and sedimentation, fish life and fish habitat between paired watersheds, one of which will be carefully logged while the other is left undisturbed as a control. This study will not compare differences in types of logging practices.

Daily Streamflow Predictions in an Ungauged Watershed in Northern California Using the Precipitation-Runoff Modeling System (PRMS): Calibration Challenges when nearby Gauged Watersheds are Hydrologically Dissimilar

NASA Astrophysics Data System (ADS)

Dhakal, A. S.; Adera, S.

2017-12-01

Accurate daily streamflow prediction in ungauged watersheds with sparse information is challenging. The ability of a hydrologic model calibrated using nearby gauged watersheds to predict streamflow accurately depends on hydrologic similarities between the gauged and ungauged watersheds. This study examines daily streamflow predictions using the Precipitation-Runoff Modeling System (PRMS) for the largely ungauged San Antonio Creek watershed, a 96 km2 sub-watershed of the Alameda Creek watershed in Northern California. The process-based PRMS model is being used to improve the accuracy of recent San Antonio Creek streamflow predictions generated by two empirical methods. Although San Antonio Creek watershed is largely ungauged, daily streamflow data exists for hydrologic years (HY) 1913 - 1930. PRMS was calibrated for HY 1913 - 1930 using streamflow data, modern-day land use and PRISM precipitation distribution, and gauged precipitation and temperature data from a nearby watershed. The PRMS model was then used to generate daily streamflows for HY 1996-2013, during which the watershed was ungauged, and hydrologic responses were compared to two nearby gauged sub-watersheds of Alameda Creek. Finally, the PRMS-predicted daily flows between HY 1996-2013 were compared to the two empirically-predicted streamflow time series: (1) the reservoir mass balance method and (2) correlation of historical streamflows from 80 - 100 years ago between San Antonio Creek and a nearby sub-watershed located in Alameda Creek. While the mass balance approach using reservoir storage and transfers is helpful for estimating inflows to the reservoir, large discrepancies in daily streamflow estimation can arise. Similarly, correlation-based predicted daily flows which rely on a relationship from flows collected 80-100 years ago may not represent current watershed hydrologic conditions. This study aims to develop a method of streamflow prediction in the San Antonio Creek watershed by examining PRMS's model outputs as well as empirically generated flow data for their use in water resources management decisions. PRMS is also being used to better understand the streamflow patterns in the San Antonio Creek watershed for a variety of antecedent soil moisture conditions as the creek is generally dry between late Spring and early Fall.

Linking watershed nitrogen sources with nitrogen dynamics in rivers of western Oregon, USA

EPA Science Inventory

We found a wide range of riverine N yields from the study basins, ranging from one to 70 kg N/ha/yr. Across the study basins, N export was more strongly correlated to fertilizer application rates than percent of agricultural area in the watershed. Low watershed N yields reflect...

Tracking the Primary Sources of Fecal Pollution in a Tropical Watershed in a One-Year Study

EPA Science Inventory

A study was conducted to determine the primary sources of fecal pollution in a subtropical watershed using host-specific assays developed in temperate regions. Water samples (n=534) from 10 different sites along the Rio Grande de Arecibo watershed were collected every two-three w...

Calibration of paired watersheds: Utility of moving sums in presence of externalities

Treesearch

Herbert Ssegane; D.M. Amatya; Augustine Muwamba; George M. Chescheir; Tim Appelboom; E.W. Tollner; Jami E. Nettles; Mohamed A. Youssef; Francois Birgand; R.W. Skaggs

2017-01-01

Historically, paired watershed studies have been used to quantify the hydrological effects of land use and management practices by concurrently monitoring two similar watersheds during calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the calibration period and tests a change...

Evaluating watershed protection programs in New York City's Cannonsville Reservoir source watershed using SWAT-HS

NASA Astrophysics Data System (ADS)

Hoang, L.; Mukundan, R.; Moore, K. E.; Owens, E. M.; Steenhuis, T. S.

2017-12-01

New York City (NYC)'s reservoirs supply over one billion gallons of drinking water each day to over nine million consumers in NYC and upstate communities. The City has invested more than $1.5 billion in watershed protection programs to maintain a waiver from filtration for the Catskill and Delaware Systems. In the last 25 years, the NYC Department of Environmental Protection (NYCDEP) has implemented programs in cooperation with upstate communities that include nutrient management, crop rotations, improvement of barnyards and manure storage, implementing tertiary treatment for Phosphorus (P) in wastewater treatment plants, and replacing failed septic systems in an effort to reduce P loads to water supply reservoirs. There have been several modeling studies evaluating the effect of agricultural Best Management Practices (BMPs) on P control in the Cannonsville watershed in the Delaware System. Although these studies showed that BMPs would reduce dissolved P losses, they were limited to farm-scale or watershed-scale estimates of reduction factors without consideration of the dynamic nature of overland flow and P losses from variable source areas. Recently, we developed the process-based SWAT-Hillslope (SWAT-HS) model, a modified version of the Soil and Water Assessment Tool (SWAT) that can realistically predict variable source runoff processes. The objective of this study is to use the SWAT-HS model to evaluate watershed protection programs addressing both point and non-point sources of P. SWAT-HS predicts streamflow very well for the Cannonsville watershed with a daily Nash Sutcliffe Efficiency (NSE) of 0.85 at the watershed outlet and NSE values ranging from 0.56 - 0.82 at five other locations within the watershed. Based on good hydrological prediction, we applied the model to predict P loads using detailed P inputs that change over time due to the implementation of watershed protection programs. Results from P model predictions provide improved projections of P loads and form a basis for evaluating the cumulative and individual effects of watershed protection programs.

Effects of mountain tea plantations on nutrient cycling at upstream watersheds

NASA Astrophysics Data System (ADS)

Lin, T.-C.; Shaner, P.-J. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

2015-11-01

The expansion of agriculture to rugged mountains can exacerbate negative impacts of agricultural activities on ecosystem function. In this study, we monitored streamwater and rainfall chemistry of mountain watersheds at the Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportion of tea plantation cover, the higher the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater of the four mountain watersheds examined; on the other hand, the concentrations of the ions that are rich in soils (SO42-, Ca2+, Mg2+) did not increase with the proportion of tea plantation cover, suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. Of the two watersheds for which rainfall chemistry was available, the one with higher proportion of tea plantation cover had higher concentrations of ions in rainfall and retained less nitrogen in proportion to input compared to the more pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. As expected, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of NO3- in streamwater by more than 70 %, indicating that such a landscape configuration helps mitigate nutrient enrichment in aquatic systems even for watersheds with steep topography. We estimated that tea plantation at our study site contributed approximately 450 kg ha-1 yr-1 of NO3-N via streamwater, an order of magnitude greater than previously reported for agricultural lands around the globe, which can only be matched by areas under intense fertilizer use. Furthermore, we constructed watershed N fluxes to show that excessive leaching of N, and additional loss to the atmosphere via volatilization and denitrification can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of agricultural activities, especially excessive fertilization, on ecosystem nutrient cycling at mountain watersheds.

Contributions of systematic tile drainage to watershed-scale phosphorus transport.

PubMed

King, Kevin W; Williams, Mark R; Fausey, Norman R

2015-03-01

Phosphorus (P) transport from agricultural fields continues to be a focal point for addressing harmful algal blooms and nuisance algae in freshwater systems throughout the world. In humid, poorly drained regions, attention has turned to P delivery through subsurface tile drainage. However, research on the contributions of tile drainage to watershed-scale P losses is limited. The objective of this study was to evaluate long-term P movement through tile drainage and its manifestation at the watershed outlet. Discharge data and associated P concentrations were collected for 8 yr (2005-2012) from six tile drains and from the watershed outlet of a headwater watershed within the Upper Big Walnut Creek watershed in central Ohio. Results showed that tile drainage accounted for 47% of the discharge, 48% of the dissolved P, and 40% of the total P exported from the watershed. Average annual total P loss from the watershed was 0.98 kg ha, and annual total P loss from the six tile drains was 0.48 kg ha. Phosphorus loads in tile and watershed discharge tended to be greater in the winter, spring, and fall, whereas P concentrations were greatest in the summer. Over the 8-yr study, P transported in tile drains represented <2% of typical application rates in this watershed, but >90% of all measured concentrations exceeded recommended levels (0.03 mg L) for minimizing harmful algal blooms and nuisance algae. Thus, the results of this study show that in systematically tile-drained headwater watersheds, the amount of P delivered to surface waters via tile drains cannot be dismissed. Given the amount of P loss relative to typical application rates, development and implementation of best management practices (BMPs) must jointly consider economic and environmental benefits. Specifically, implementation of BMPs should focus on late fall, winter, and early spring seasons when most P loading occurs. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Nutrient Characterization of Rainwater, Soil and Groundwater from Two Different Watersheds, Lake Taihu, China

NASA Astrophysics Data System (ADS)

Thaw, M.; Gao, F.; Yu, Z.; Acharya, K.

2012-12-01

Over the past two decades, an increase of nutrients to Lake Taihu, China has resulted in hyper-eutrophication and the production of severe cyanobacterial blooms. While many past studies have focused on how surface water transports nutrients to the lake, this study seeks to characterize the concentration of nutrients in different media, including rainwater, soil and groundwater from two different watersheds. These two watersheds varied in overall land use, and agricultural sites within each watershed varied by crop type and growing method. Samples were collected from the Meilin watershed, a mix of forest and agricultural land and the Zhangjiagang watershed, which consisted of industrial, urban and agricultural lands. Samples included soils, groundwater and rain water. Soils from each site were characterized by aggregate size class and analyzed for total nitrogen and total phosphorus. Rainwater and groundwater samples were analyzed for total nitrogen and total phosphorus.

Estimation of runoff and sediment yield in the Redrock Creek watershed using AnnAGNPS and GIS

USGS Publications Warehouse

Tsou, Ming‐shu; Zhan, X.-Y.

2004-01-01

Sediment has been identified as a significant threat to water quality and channel clogging that in turn may lead to river flooding. With the increasing awareness of the impairment from sediment to water bodies in a watershed, identifying the locations of the major sediment sources and reducing the sediment through management practices will be important for an effective watershed management. The annualized agricultural non-point source pollution (AnnAGNPS) model and newly developed GIS interface for it were applied in a small agricultural watershed, Redrock Creek watershed, Kansas, in this pilot study for exploring the effectiveness of using this model as a management tool. The calibrated model appropriately simulated monthly runoff and sediment yield through the practices in this study and potentially suggested the ways of sediment reduction through evaluating the changes of land use and field operation in the model for the purpose of watershed management.

Effects of surface coal mining and reclamation on the geohydrology of six small watersheds in west-central Indiana

USGS Publications Warehouse

Martin, Jeffrey D.; Duwelius, Richard F.; Crawford, Charles G.

1987-01-01

The watersheds studied include mined and reclaimed; mined and unreclaimed; and unmined, agricultural land uses, and are each < 3 sq mi in area. Surface water, groundwater, and meteorologic data for the 1981 and 1982 water years were used to describe and compare hydrologic systems of the six watersheds and to identify hydrologic effects of mining and reclamation. Peak discharges were greater at the agricultural watersheds than at the unreclaimed watersheds, primarily because of large final-cut lakes in the unreclaimed watersheds. Annual runoff was greatest at the unreclaimed watersheds, intermediate at the agricultural watersheds, and least at the reclaimed watersheds. Hydrologic effects of mining were identified by comparing the hydrologic systems at mined and unreclaimed watersheds with those at unmined, agricultural watersheds. Comparisons of the hydrologic systems of these watersheds indicate that surface coal mining without reclamation has the potential to increase annual runoff, base flow, and groundwater recharge to the bedrock; reduce peak flow rates and variation in flow; lower the water table in upland areas; change the relation between surface water and groundwater divides; and create numerous, local flow systems in the shallow groundwater. Hydrologic effects of reclamation were identified by comparing the hydrologic systems at mined and reclaimed watersheds with those at mined and unreclaimed watersheds. Reclamation has the potential to decrease annual runoff, base flow, and recharge to the bedrock; increase peak flow rates, variation in flow, and response to thunderstorms; reestablish the premining relation between surface and groundwater divides; and create fewer local flow systems in the shallow groundwater. (Lantz-PTT)

Watershed Profiles and Stream-net Structure of Vesuvio Volcano, Italy

NASA Astrophysics Data System (ADS)

Lin, Z.; Oguchi, T.; Komatsu, G.

2006-12-01

Watershed topography including stream-net structure in 32 watersheds of Vesuvio Volcano was analyzed using a DEM with a 20-m resolution, with special attention to geomorphological differences between the northern ?0-8 area and the other areas. The longitudinal and transverse profiles and stream-nets of the watersheds were extracted from the DEM. Drainage density and statistical morphometric parameters representing the shape of the profiles were investigated, and their relations with other basic morphometric parameters such as slope angle were examined. The relationships between drainage density and slope angle for each watershed can be divided into two types: Type 1 - negative correlation and Type 2 - convex-form correlation. The Type 2 watersheds have smaller bifurcation ratios and larger low-order stream lengths than the Type 1 watersheds, indicating that low-order streams in the Type 2 watersheds are more integrated. The results of longitudinal and transverse profile analyses also show that the topography of the Type 2 watersheds is simpler and more organized than that of the Type 1 watersheds, suggesting that the Type 2 watersheds are closer to equilibrium conditions. The Type 2 watersheds are located in the steepest and highest part of the somma area, where only limited eruption products have been deposited during the Holocene, due to the existence of the high and steep outer rim of the caldera at the top of the volcano. The results including the existence of the two types are similar to those from non-volcanic watersheds in Japan, indicating that stream-net studies combined with profile analysis using DEMs are effective in discussing the erosional stages of watersheds.

Robust Decision Making to Support Water Quality Climate Adaptation: a Case Study in the Chesapeake Bay Watershed

NASA Astrophysics Data System (ADS)

Fischbach, J. R.; Lempert, R. J.; Molina-Perez, E.

2017-12-01

The U.S. Environmental Protection Agency (USEPA), together with state and local partners, develops watershed implementation plans designed to meet water quality standards. Climate uncertainty, along with uncertainty about future land use changes or the performance of water quality best management practices (BMPs), may make it difficult for these implementation plans to meet water quality goals. In this effort, we explored how decision making under deep uncertainty (DMDU) methods such as Robust Decision Making (RDM) could help USEPA and its partners develop implementation plans that are more robust to future uncertainty. The study focuses on one part of the Chesapeake Bay watershed, the Patuxent River, which is 2,479 sq km in area, highly urbanized, and has a rapidly growing population. We simulated the contribution of stormwater contaminants from the Patuxent to the overall Total Maximum Daily Load (TMDL) for the Chesapeake Bay under multiple scenarios reflecting climate and other uncertainties. Contaminants considered included nitrogen, phosphorus, and sediment loads. The assessment included a large set of scenario simulations using the USEPA Chesapeake Bay Program's Phase V watershed model. Uncertainties represented in the analysis included 18 downscaled climate projections (based on 6 general circulation models and 3 emissions pathways), 12 land use scenarios with different population projections and development patterns, and alternative assumptions about BMP performance standards and efficiencies associated with different suites of stormwater BMPs. Finally, we developed cost estimates for each of the performance standards and compared cost to TMDL performance as a key tradeoff for future water quality management decisions. In this talk, we describe how this research can help inform climate-related decision support at USEPA's Chesapeake Bay Program, and more generally how RDM and other DMDU methods can support improved water quality management under climate uncertainty.

Modeling Agricultural Watersheds with the Soil and Water Assessment Tool (SWAT): Calibration and Validation with a Novel Procedure for Spatially Explicit HRUs.

PubMed

Teshager, Awoke Dagnew; Gassman, Philip W; Secchi, Silvia; Schoof, Justin T; Misgna, Girmaye

2016-04-01

Applications of the Soil and Water Assessment Tool (SWAT) model typically involve delineation of a watershed into subwatersheds/subbasins that are then further subdivided into hydrologic response units (HRUs) which are homogeneous areas of aggregated soil, landuse, and slope and are the smallest modeling units used within the model. In a given standard SWAT application, multiple potential HRUs (farm fields) in a subbasin are usually aggregated into a single HRU feature. In other words, the standard version of the model combines multiple potential HRUs (farm fields) with the same landuse/landcover, soil, and slope, but located at different places of a subbasin (spatially non-unique), and considers them as one HRU. In this study, ArcGIS pre-processing procedures were developed to spatially define a one-to-one match between farm fields and HRUs (spatially unique HRUs) within a subbasin prior to SWAT simulations to facilitate input processing, input/output mapping, and further analysis at the individual farm field level. Model input data such as landuse/landcover (LULC), soil, crop rotation, and other management data were processed through these HRUs. The SWAT model was then calibrated/validated for Raccoon River watershed in Iowa for 2002-2010 and Big Creek River watershed in Illinois for 2000-2003. SWAT was able to replicate annual, monthly, and daily streamflow, as well as sediment, nitrate and mineral phosphorous within recommended accuracy in most cases. The one-to-one match between farm fields and HRUs created and used in this study is a first step in performing LULC change, climate change impact, and other analyses in a more spatially explicit manner.

A Bayesian-based multilevel factorial analysis method for analyzing parameter uncertainty of hydrological model

NASA Astrophysics Data System (ADS)

Liu, Y. R.; Li, Y. P.; Huang, G. H.; Zhang, J. L.; Fan, Y. R.

2017-10-01

In this study, a Bayesian-based multilevel factorial analysis (BMFA) method is developed to assess parameter uncertainties and their effects on hydrological model responses. In BMFA, Differential Evolution Adaptive Metropolis (DREAM) algorithm is employed to approximate the posterior distributions of model parameters with Bayesian inference; factorial analysis (FA) technique is used for measuring the specific variations of hydrological responses in terms of posterior distributions to investigate the individual and interactive effects of parameters on model outputs. BMFA is then applied to a case study of the Jinghe River watershed in the Loess Plateau of China to display its validity and applicability. The uncertainties of four sensitive parameters, including soil conservation service runoff curve number to moisture condition II (CN2), soil hydraulic conductivity (SOL_K), plant available water capacity (SOL_AWC), and soil depth (SOL_Z), are investigated. Results reveal that (i) CN2 has positive effect on peak flow, implying that the concentrated rainfall during rainy season can cause infiltration-excess surface flow, which is an considerable contributor to peak flow in this watershed; (ii) SOL_K has positive effect on average flow, implying that the widely distributed cambisols can lead to medium percolation capacity; (iii) the interaction between SOL_AWC and SOL_Z has noticeable effect on the peak flow and their effects are dependent upon each other, which discloses that soil depth can significant influence the processes of plant uptake of soil water in this watershed. Based on the above findings, the significant parameters and the relationship among uncertain parameters can be specified, such that hydrological model's capability for simulating/predicting water resources of the Jinghe River watershed can be improved.

The assessment of water use and reuse through reported data: A US case study.

PubMed

Wiener, Maria J; Jafvert, Chad T; Nies, Loring F

2016-01-01

Increasing demands for freshwater make it necessary to find innovative ways to extend the life of our water resources, and to manage them in a sustainable way. Indirect water reuse plays a role in meeting freshwater demands but there is limited documentation of it. There is a need to analyze its current status for water resources planning and conservation, and for understanding how it potentially impacts human health. However, the fact that data are archived in discrete uncoordinated databases by different state and federal entities, limits the capacity to complete holistic analysis of critical resources at large watershed scales. Humans alter the water cycle for food production, manufacturing, energy production, provision of potable water and recreation. Ecosystems services are affected at watershed scales but there are also global scale impacts from greenhouse gas emissions enabled by access to cooling, processing and irrigation water. To better document these issues and to demonstrate the utility of such an analysis, we studied the Wabash River Watershed located in the U.S. Midwest. Data for water extraction, use, discharge, and river flow were collected, curated and reorganized in order to characterize the water use and reuse within the basin. Indirect water reuse was estimated by comparing treated wastewater discharges with stream flows at selected points within the watershed. Results show that during the low flow months of July-October, wastewater discharges into the Wabash River basin contributed 82 to 121% of the stream flow, demonstrating that the level of water use and unplanned reuse is significant. These results suggest that intentional water reuse for consumptive purposes such as landscape or agricultural irrigation could have substantial ecological impacts by diminishing stream flow during vulnerable low flow periods. Copyright © 2015. Published by Elsevier B.V.

Impacts of boreal hydroelectric reservoirs on seasonal climate and precipitation recycling as simulated by the CRCM5: a case study of the La Grande River watershed, Canada

NASA Astrophysics Data System (ADS)

Irambona, C.; Music, B.; Nadeau, D. F.; Mahdi, T. F.; Strachan, I. B.

2018-02-01

Located in northern Quebec, Canada, eight hydroelectric reservoirs of a 9782-km2 maximal area cover 6.4% of the La Grande watershed. This study investigates the changes brought by the impoundment of these reservoirs on seasonal climate and precipitation recycling. Two 30-year climate simulations, corresponding to pre- and post-impoundment conditions, were used. They were generated with the fifth-generation Canadian Regional Climate Model (CRCM5), fully coupled to a 1D lake model (FLake). Seasonal temperatures and annual energy budget were generally well reproduced by the model, except in spring when a cold bias, probably related to the overestimation of snow cover, was seen. The difference in 2-m temperature shows that reservoirs induce localized warming in winter (+0.7 ± 0.02 °C) and cooling in the summer (-0.3 ± 0.02 °C). The available energy at the surface increases throughout the year, mostly due to a decrease in surface albedo. Fall latent and sensible heat fluxes are enhanced due to additional energy storage and availability in summer and spring. The changes in precipitation and runoff are within the model internal variability. At the watershed scale, reservoirs induce an additional evaporation of only 5.9 mm year-1 (2%). We use Brubaker's precipitation recycling model to estimate how much of the precipitation is recycled within the watershed. In both simulations, the maximal precipitation recycling occurs in July (less than 6%), indicating weak land-atmosphere coupling. Reservoirs do not seem to affect this coupling, as precipitation recycling only decreased by 0.6% in July.

Modeling Agricultural Watersheds with the Soil and Water Assessment Tool (SWAT): Calibration and Validation with a Novel Procedure for Spatially Explicit HRUs

NASA Astrophysics Data System (ADS)

Teshager, Awoke Dagnew; Gassman, Philip W.; Secchi, Silvia; Schoof, Justin T.; Misgna, Girmaye

2016-04-01

Applications of the Soil and Water Assessment Tool (SWAT) model typically involve delineation of a watershed into subwatersheds/subbasins that are then further subdivided into hydrologic response units (HRUs) which are homogeneous areas of aggregated soil, landuse, and slope and are the smallest modeling units used within the model. In a given standard SWAT application, multiple potential HRUs (farm fields) in a subbasin are usually aggregated into a single HRU feature. In other words, the standard version of the model combines multiple potential HRUs (farm fields) with the same landuse/landcover, soil, and slope, but located at different places of a subbasin (spatially non-unique), and considers them as one HRU. In this study, ArcGIS pre-processing procedures were developed to spatially define a one-to-one match between farm fields and HRUs (spatially unique HRUs) within a subbasin prior to SWAT simulations to facilitate input processing, input/output mapping, and further analysis at the individual farm field level. Model input data such as landuse/landcover (LULC), soil, crop rotation, and other management data were processed through these HRUs. The SWAT model was then calibrated/validated for Raccoon River watershed in Iowa for 2002-2010 and Big Creek River watershed in Illinois for 2000-2003. SWAT was able to replicate annual, monthly, and daily streamflow, as well as sediment, nitrate and mineral phosphorous within recommended accuracy in most cases. The one-to-one match between farm fields and HRUs created and used in this study is a first step in performing LULC change, climate change impact, and other analyses in a more spatially explicit manner.

Streambanks: A net source of sediment and phosphorus to streams and rivers.

PubMed

Fox, Garey A; Purvis, Rebecca A; Penn, Chad J

2016-10-01

Sediment and phosphorus (P) are two primary pollutants of surface waters. Many studies have investigated loadings from upland sources or even streambed sediment, but in many cases, limited to no data exist to determine sediment and P loading from streambanks on a watershed scale. The objectives of this paper are to review the current knowledge base on streambank erosion and failure mechanisms, streambank P concentrations, and streambanks as P loading sources and then also to identify future research needs on this topic. In many watersheds, long-term loading of soil and associated P to stream systems has created a source of eroded soil and P that may interact with streambank sediment and be deposited in floodplains downstream. In many cases streambanks were formed from previously eroded and deposited alluvial material and so the resulting soils possess unique physical and chemical properties from adjacent upland soils. Streambank sediment and P loading rates depend explicitly on the rate of streambank migration and the concentration of P stored within bank materials. From the survey of literature, previous studies report streambank total P concentrations that consistently exceeded 250 mg kg(-1) soil. Only a few studies also reported water soluble or extractable P concentrations. More research should be devoted to understanding the dynamic processes between different P pools (total P versus bioavailable P), and sorption or desorption processes under varying hydraulic and stream chemistry conditions. Furthermore, the literature reported that streambank erosion and failure and gully erosion were reported to account for 7-92% of the suspended sediment load within a channel and 6-93% of total P. However, significant uncertainty can occur in such estimates due to reach-scale variability in streambank migration rates and future estimates should consider the use of uncertainty analysis approaches. Research is also needed on the transport rates of dissolved and sediment-bound P through the entire stream system of a watershed to identify critical upland and/or near-stream conservation practices. Extensive monitoring of the impact of restoration/rehabilitation efforts on reducing sediment and P loading are limited. From an application standpoint, streambank P contributions to streams should be more explicitly accounted for in developing total maximum daily loads in watersheds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Storm Event Suspended Sediment-Discharge Hysteresis and Controls in Agricultural Watersheds: Implications for Watershed Scale Sediment Management.

PubMed

Sherriff, Sophie C; Rowan, John S; Fenton, Owen; Jordan, Philip; Melland, Alice R; Mellander, Per-Erik; hUallacháin, Daire Ó

2016-02-16

Within agricultural watersheds suspended sediment-discharge hysteresis during storm events is commonly used to indicate dominant sediment sources and pathways. However, availability of high-resolution data, qualitative metrics, longevity of records, and simultaneous multiwatershed analyses has limited the efficacy of hysteresis as a sediment management tool. This two year study utilizes a quantitative hysteresis index from high-resolution suspended sediment and discharge data to assess fluctuations in sediment source location, delivery mechanisms and export efficiency in three intensively farmed watersheds during events over time. Flow-weighted event sediment export was further considered using multivariate techniques to delineate rainfall, stream hydrology, and antecedent moisture controls on sediment origins. Watersheds with low permeability (moderately- or poorly drained soils) with good surface hydrological connectivity, therefore, had contrasting hysteresis due to source location (hillslope versus channel bank). The well-drained watershed with reduced connectivity exported less sediment but, when watershed connectivity was established, the largest event sediment load of all watersheds occurred. Event sediment export was elevated in arable watersheds when low groundcover was coupled with high connectivity, whereas in the grassland watershed, export was attributed to wetter weather only. Hysteresis analysis successfully indicated contrasting seasonality, connectivity and source availability and is a useful tool to identify watershed specific sediment management practices.

Hydrologic Responses to Projected Climate Change in Ecologically-Vulnerable Watersheds of the Gulf Coast, USA

NASA Astrophysics Data System (ADS)

Neupane, R. P.; Ficklin, D. L.; Knouft, J.

2017-12-01

Climate change is likely to have significant effects on the water cycle of the Gulf Coast watersheds in the United States, which contain some of the highest levels of biodiversity of all freshwater systems in North America. Understanding potential hydrologic responses to continued climate change in these watersheds is important for management of water resources and to sustain ecological diversity. We used the Soil and Water Assessment Tool (SWAT) to simulate hydrologic processes and estimate the potential hydrological changes for the mid-21st century (2050s) and the late-21st century (2080s) in the Mobile River, Apalachicola River, and Suwannee River watersheds located in the Gulf Coast, USA. These estimates were based on downscaled future climate projections from 20 Global Circulation Models (GCMs) under two Representative Concentration Pathways (RCPs 4.5 and 8.5). Models were calibrated and validated using observed data from 58, 19, and 14 streamflow gauges in the Mobile River, Apalachicola River, and Suwannee River watersheds, respectively. Evaluation indices including the Nash-Sutcliffe efficiency (NSE), coefficient of determination (R2), and refined index of agreement (dr) were used to assess model quality. The mean values derived during calibration (NSE=0.68, R2=0.77, and dr=0.73) and validation (NSE=0.70, R2=0.78, and dr=0.74) of all watersheds indicated that the models performed well at simulating monthly streamflow. Our simulation results indicated an overall increase in mean annual streamflow for all the watersheds with a maximum increase in discharge of 28.6% for the Suwannee River watershed for RCP 4.5 during the 2080s, which is associated with a 6.8% increase in precipitation during the same time period. We observed an overall warming (4.2oC) with an increase in future precipitation (3.8%) in all watersheds during the 2080s under the worst-case RCP 8.5 scenario compared to the historical time period. Despite an increase in future precipitation, surface runoff in the Suwannee River watershed was lower than might be expected due to a large portion of wetlands ( 28% of total area) acting as buffers to capture overland flows. These outcomes are expected to help in making better-informed decisions for future water resources and ecosystem management in the Gulf Coast region during the coming century.

Modeling the influence of climate change on watershed systems: Adaptation through targeted practices

NASA Astrophysics Data System (ADS)

Dudula, John; Randhir, Timothy O.

2016-10-01

Climate change may influence hydrologic processes of watersheds (IPCC, 2013) and increased runoff may cause flooding, eroded stream banks, widening of stream channels, increased pollutant loading, and consequently impairment of aquatic life. The goal of this study was to quantify the potential impacts of climate change on watershed hydrologic processes and to evaluate scale and effectiveness of management practices for adaptation. We simulate baseline watershed conditions using the Hydrological Simulation Program Fortran (HSPF) simulation model to examine the possible effects of changing climate on watershed processes. We also simulate the effects of adaptation and mitigation through specific best management strategies for various climatic scenarios. With continuing low-flow conditions and vulnerability to climate change, the Ipswich watershed is the focus of this study. We quantify fluxes in runoff, evapotranspiration, infiltration, sediment load, and nutrient concentrations under baseline and climate change scenarios (near and far future). We model adaptation options for mitigating climate effects on watershed processes using bioretention/raingarden Best Management Practices (BMPs). It was observed that climate change has a significant impact on watershed runoff and carefully designed and maintained BMPs at subwatershed scale can be effective in mitigating some of the problems related to stormwater runoff. Policy options include implementation of BMPs through education and incentives for scale-dependent and site specific bioretention units/raingardens to increase the resilience of the watershed system to current and future climate change.

Biogeochemical and Hydrological Controls on Mercury and Methylmercury in First Order Coastal Plain Watersheds of the Chesapeake Bay

NASA Astrophysics Data System (ADS)

Heyes, A.; Gilmour, C. C.; Bell, J. T.; Butera, D.; McBurney, A. W.

2015-12-01

Over the past 7 years we made use of the long-term research site at the Smithsonian Environmental Research Center (SERC) in central Maryland to study the fluxes of mercury (Hg) and methylmercury (MeHg) in three small first-order mid-Atlantic coastal plain watersheds. One watershed is entirely forested, one watershed is primarily agriculture with a forested stream buffer, and one watershed is mixed land use but contains a beaver produced wetland pond. Our initial goals were to assess watershed Hg yields in the mid-Atlantic and to establish a baseline prior to implementation of Hg emissions controls. All three studied watersheds produced relatively high yields of Hg, with the greatest yield coming from the forested watershed. Our initial evaluation of three watersheds showed that MeHg production and flux could also be high, but varied dramatically among watersheds and across years and seasons. During each year we observed episodic MeHg production in the spring and sometimes during prolonged high-flow storm events in the fall. The observed spring maxima of MeHg release coincided with development of anoxia in riparian groundwater. MeHg accumulation in riparian groundwater began once nitrate was depleted and either iron accumulation or sulfate depletion of groundwater began. We propose the presence of nitrate was modulating MeHg production through the suppression of sulfate and iron reducers and perhaps methanogens. As sulfate is not limiting in any of the watersheds owing to the sediments marine origin, we hypothesize the depletion of nitrate allows sulfate reducing bacteria to now utilize available carbon. Although wetlands are generally thought of as the primary zones of MeHg production in watersheds, shallow riparian groundwaters very close to the stream appear to play that role in SERC Coastal Plain watersheds. We hypothesize that the balance between nitrate, sulfate and other microbial electron acceptors in watersheds is a major control on MeHg production. Land management practices that change upset this balance by changing nitrate load and carbon quality will undoubtedly impact the cycling of Hg.

Nitrogen (N) dynamics in the mineral soil of a Central Appalachian hardwood forest during a quarter century of whole-watershed N additions

Treesearch

Frank S. ​Gilliam; Christopher A. Walter; Mary Beth Adams; William T. Peterjohn

2018-01-01

The structure and function of terrestrial ecosystemsare maintained by processes that vary with temporal and spatial scale. This study examined temporal and spatial patterns of net nitrogen (N) mineralization and nitrification in mineral soil of three watersheds at the Fernow Experimental Forest, WV: 2 untreated watersheds and 1 watershed receiving aerial applications...

Physiography, geology, and land cover of four watersheds in Eastern Puerto Rico

Treesearch

S.F. Murphy; R.F. Stallard; M.C. Larsen; W.A. Gould

2012-01-01

Four watersheds with differing geology and land cover in eastern Puerto Rico have been studied on a long-term basis by the U.S. Geological Survey to evaluate water, energy, and biogeochemical budgets. These watersheds are typical of tropical, island-arc settings found in many parts of the world. Two watersheds are located on coarse-grained granitic rocks that weather...

Long-term forest watershed studies in the Southwest: recycled for wildfire and prescribed fire

Treesearch

Daniel G. Neary; Gerald J. Gottfried; Peter F. Ffolliott; Boris Poff

2012-01-01

A hydrologic research network was established in Arizona in the 1950s and 1960s called the Arizona Watershed Program (Baker et al. 1999). It consisted of a number of public agencies and private groups interested in obtaining more water for future economic growth while maintaining the State's watersheds in good condition. As part of the Program. paired watershed...

Applications of long-term watershed research to forest management in California: 50 Years of Learning from the Caspar Creek Watershed Study

Treesearch

Cafferata Peter; Leslie Reid

2013-01-01

For over 50 years, the Caspar Creek Experimental Watersheds, located in western Mendocino County, California, have been the site of long-term cooperative watershed research carried out by the U.S. Forest Service Pacific Southwest Research Station (PSW) and the California Department of Forestry and Fire Protection (CAL FIRE). Preliminary stream flow, suspended...

Brain injury patterns in hypoglycemia in neonatal encephalopathy.

PubMed

Wong, D S T; Poskitt, K J; Chau, V; Miller, S P; Roland, E; Hill, A; Tam, E W Y

2013-07-01

Low glucose values are often seen in term infants with NE, including HIE, yet the contribution of hypoglycemia to the pattern of neurologic injury remains unclear. We hypothesized that MR features of neonatal hypoglycemia could be detected, superimposed on the predominant HIE injury pattern. Term neonates (n = 179) with NE were prospectively imaged with day-3 MR studies and had glucose data available for review. The predominant imaging pattern of HIE was recorded as watershed, basal ganglia, total, focal-multifocal, or no injury. Radiologic hypoglycemia was diagnosed on the basis of selective edema in the posterior white matter, pulvinar, and anterior medial thalamic nuclei. Clinical charts were reviewed for evidence of NE, HIE, and hypoglycemia (<46 mg/dL). The predominant pattern of HIE injury imaged included 17 watershed, 25 basal ganglia, 10 total, 42 focal-multifocal, and 85 cases of no injury. A radiologic diagnosis of hypoglycemia was made in 34 cases. Compared with laboratory-confirmed hypoglycemia, MR findings had a positive predictive value of 82% and negative predictive value of 78%. Sixty (34%) neonates had clinical hypoglycemia before MR imaging. Adjusting for 5-minute Apgar scores and umbilical artery pH with logistic regression, clinical hypoglycemia was associated with a 17.6-fold higher odds of MR imaging identification (P < .001). Selective posterior white matter and pulvinar edema were most predictive of clinical hypoglycemia, and no injury (36%) or a watershed (32%) pattern of injury was seen more often in severe hypoglycemia. In term infants with NE and hypoglycemia, specific imaging features for both hypoglycemia and hypoxia-ischemia can be identified.

Metal and Nutrient Distribution and Fractionation in Managed Urban Watersheds Across the US Southwest

NASA Astrophysics Data System (ADS)

Papelis, C.; Williams, A. C.; Boettcher, T. M.

2008-12-01

Metals, metalloids, and nutrients are common contaminants of concern in arid and semi-arid watersheds in the Southwestern U.S. Because of the dramatic population growth in this part of the U.S., the potential for contamination of urban watersheds has also increased over the last few decades. Streams in urban watersheds receive storm water, urban runoff, shallow groundwater, and treated wastewater, among other sources. In addition, urban watersheds are often heavily managed to mitigate flood events and sediment- related impacts. Sediment transport can have a profound effect on the water quality of affected bodies of water. However, differences in geology, hydrogeology, and land use may have dramatic effects on the distribution of nutrients and metals in different urban watersheds. To test these effects, aqueous and sediment samples were collected above and below erosion control and other structures along two heavily managed urban watersheds, namely the Las Vegas Wash in the Las Vegas Valley Watershed, Nevada, and the Rio Salado (Salt River) in the Phoenix Metropolitan Area, Arizona. The construction of such control structures has the potential to alter the distribution of metals and metalloids in bodies of water used by wildlife. In this study, all sediments were characterized by particle size distribution, specific surface area, mineralogical composition, and scanning electron microscopy. The results of total arsenic, boron, and phosphorus extractions will be discussed, as a function of sediment characteristics. Significant differences exist between the two U.S. Southwest watersheds studied, including land use, water sources, sediment characteristics, nutrient and metal distribution, and overall system complexity. These differences lead to significant variations in metalloid and nutrient distributions in the two watersheds. Differences and similarities in the two systems will be explained as a function of sediment characteristics and watershed properties.

A study of remote sensing as applied to regional and small watersheds. Volume 1: Summary report

NASA Technical Reports Server (NTRS)

Ambaruch, R.

1974-01-01

The accuracy of remotely sensed measurements to provide inputs to hydrologic models of watersheds is studied. A series of sensitivity analyses on continuous simulation models of three watersheds determined: (1)Optimal values and permissible tolerances of inputs to achieve accurate simulation of streamflow from the watersheds; (2) Which model inputs can be quantified from remote sensing, directly, indirectly or by inference; and (3) How accurate remotely sensed measurements (from spacecraft or aircraft) must be to provide a basis for quantifying model inputs within permissible tolerances.

Modeling the influence of septic systems on fecal bacteria load in a suburban watershed in Georgia (GWRC 2017)

EPA Science Inventory

Watershed scale models such as the soil and water assessment tool (SWAT) are promising tools for studying the impacts of septic systems on water quality and quantity. In this study, SWAT was used to assess the influence of septic systems on bacterial loads in a suburban watershed...

Nitrogen fluxes and retention in urban watershed ecosystems

Treesearch

Peter M. Groffman; Neely L. Law; Kenneth T. Belt; Lawrence E. Band; Gary T. Fisher

2004-01-01

Although the watershed approach has long been used to study whole-ecosystem function, it has seldom been applied to study human-dominated systems, especially those dominated by urban and suburban land uses. Here we present 3 years of data on nitrogen (N) losses from one completely forested, one agricultural, and six urban/suburban watersheds, and input--output N...

Analysis of regional rainfall-runoff parameters for the Lake Michigan Diversion hydrological modeling

USGS Publications Warehouse

Soong, David T.; Over, Thomas M.

2015-01-01

Recalibration of the HSPF parameters to the updated inputs and land covers was completed on two representative watershed models selected from the nine by using a manual method (HSPEXP) and an automatic method (PEST). The objective of the recalibration was to develop a regional parameter set that improves the accuracy in runoff volume prediction for the nine study watersheds. Knowledge about flow and watershed characteristics plays a vital role for validating the calibration in both manual and automatic methods. The best performing parameter set was determined by the automatic calibration method on a two-watershed model. Applying this newly determined parameter set to the nine watersheds for runoff volume simulation resulted in “very good” ratings in five watersheds, an improvement as compared to “very good” ratings achieved for three watersheds by the North Branch parameter set.

Factors Influencing Watershed Average Erosion Rates Calculated from Reservoir Sedimentation in Eastern USA

NASA Astrophysics Data System (ADS)

Ahamed, A.; Snyder, N. P.; David, G. C.

2014-12-01

The Reservoir Sedimentation Database (ResSed), a catalogue of reservoirs and depositional data that has recently become publically available, allows for rapid calculation of sedimentation rates and rates of capacity loss over short (annual to decadal) timescales. This study is a statistical investigation of factors controlling watershed average erosion rates (E) in eastern United States watersheds. We develop an ArcGIS-based model that delineates watersheds upstream of ResSed dams and calculate drainage areas to determine E for 191 eastern US watersheds. Geomorphic, geologic, regional, climatic, and land use variables are quantified within study watersheds using GIS. Erosion rates exhibit a large amount of scatter, ranging from 0.001 to 1.25 mm/yr. A weak inverse power law relationship between drainage area (A) and E (R2 = 0.09) is evident, similar to other studies (e.g. Milliman and Syvitski, 1992; Koppes and Montgomery, 2009). Linear regressions reveal no relationship between mean watershed slope (S) and E, possibly due to the relatively low relief of the region (mean S for all watersheds is 6°). Analysis of Variance shows that watersheds in formerly glaciated regions exhibit a statistically significant lower mean E (0.06 mm/year) than watersheds in unglaciated regions (0.12 mm/year), but that watersheds with different dam purposes show no significant differences in mean E. Linear regressions reveal no relationships between E and land use parameters like percent agricultural land and percent impervious surfaces (I), but classification and regression trees indicate that watersheds in highly developed regions (I > 34%) exhibit mean E (0.36 mm/year) that is four times higher than watersheds in less developed (I < 34%) regions (0.09 mm/year). Further, interactions between land use variables emerge in formerly glaciated regions, where increased agricultural land results in higher rates of annual capacity loss in reservoirs (R2 = 0.56). Plots of E versus timescale of measurement (e.g., Sadler and Jerolmack, 2014) show that nearly the full range of observed E, including the highest values, are seen over short survey intervals (< 20 years), suggesting that whether or not large sedimentation events (such as floods) occur between two surveys may explain the high degree of variability in measured rates.

Baseline for Climate Change: Modeling Watershed Aquatic Biodiversity Relative to Environmental and Anthropogenic Factors

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

Maurakis, Eugene G

Objectives of the two-year study were to (1) establish baselines for fish and macroinvertebrate community structures in two mid-Atlantic lower Piedmont watersheds (Quantico Creek, a pristine forest watershed; and Cameron Run, an urban watershed, Virginia) that can be used to monitor changes relative to the impacts related to climate change in the future; (2) create mathematical expressions to model fish species richness and diversity, and macroinvertebrate taxa and macroinvertebrate functional feeding group taxa richness and diversity that can serve as a baseline for future comparisons in these and other watersheds in the mid-Atlantic region; and (3) heighten people’s awareness, knowledgemore » and understanding of climate change and impacts on watersheds in a laboratory experience and interactive exhibits, through internship opportunities for undergraduate and graduate students, a week-long teacher workshop, and a website about climate change and watersheds. Mathematical expressions modeled fish and macroinvertebrate richness and diversity accurately well during most of the six thermal seasons where sample sizes were robust. Additionally, hydrologic models provide the basis for estimating flows under varying meteorological conditions and landscape changes. Continuations of long-term studies are requisite for accurately teasing local human influences (e.g. urbanization and watershed alteration) from global anthropogenic impacts (e.g. climate change) on watersheds. Effective and skillful translations (e.g. annual potential exposure of 750,000 people to our inquiry-based laboratory activities and interactive exhibits in Virginia) of results of scientific investigations are valuable ways of communicating information to the general public to enhance their understanding of climate change and its effects in watersheds.« less

Estimating watershed degradation over the last century and its impact on water-treatment costs for the world’s large cities

PubMed Central

McDonald, Robert I.; Weber, Katherine F.; Padowski, Julie; Boucher, Tim; Shemie, Daniel

2016-01-01

Urban water systems are impacted by land use within their source watersheds, as it affects raw water quality and thus the costs of water treatment. However, global estimates of the effect of land cover change on urban water-treatment costs have been hampered by a lack of global information on urban source watersheds. Here, we use a unique map of the urban source watersheds for 309 large cities (population > 750,000), combined with long-term data on anthropogenic land-use change in their source watersheds and data on water-treatment costs. We show that anthropogenic activity is highly correlated with sediment and nutrient pollution levels, which is in turn highly correlated with treatment costs. Over our study period (1900–2005), median population density has increased by a factor of 5.4 in urban source watersheds, whereas ranching and cropland use have increased by a factor of 3.4 and 2.0, respectively. Nearly all (90%) of urban source watersheds have had some level of watershed degradation, with the average pollutant yield of urban source watersheds increasing by 40% for sediment, 47% for phosphorus, and 119% for nitrogen. We estimate the degradation of watersheds over our study period has impacted treatment costs for 29% of cities globally, with operation and maintenance costs for impacted cities increasing on average by 53 ± 5% and replacement capital costs increasing by 44 ± 14%. We discuss why this widespread degradation might be occurring, and strategies cities have used to slow natural land cover loss. PMID:27457941

Hydrologic Effects of Brush Management in Central Texas

NASA Astrophysics Data System (ADS)

Banta, J. R.; Slattery, R.

2011-12-01

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.

Estimating watershed degradation over the last century and its impact on water-treatment costs for the world's large cities.

PubMed

McDonald, Robert I; Weber, Katherine F; Padowski, Julie; Boucher, Tim; Shemie, Daniel

2016-08-09

Urban water systems are impacted by land use within their source watersheds, as it affects raw water quality and thus the costs of water treatment. However, global estimates of the effect of land cover change on urban water-treatment costs have been hampered by a lack of global information on urban source watersheds. Here, we use a unique map of the urban source watersheds for 309 large cities (population > 750,000), combined with long-term data on anthropogenic land-use change in their source watersheds and data on water-treatment costs. We show that anthropogenic activity is highly correlated with sediment and nutrient pollution levels, which is in turn highly correlated with treatment costs. Over our study period (1900-2005), median population density has increased by a factor of 5.4 in urban source watersheds, whereas ranching and cropland use have increased by a factor of 3.4 and 2.0, respectively. Nearly all (90%) of urban source watersheds have had some level of watershed degradation, with the average pollutant yield of urban source watersheds increasing by 40% for sediment, 47% for phosphorus, and 119% for nitrogen. We estimate the degradation of watersheds over our study period has impacted treatment costs for 29% of cities globally, with operation and maintenance costs for impacted cities increasing on average by 53 ± 5% and replacement capital costs increasing by 44 ± 14%. We discuss why this widespread degradation might be occurring, and strategies cities have used to slow natural land cover loss.

Upper Washita River experimental watersheds: Sediment Database

USDA-ARS?s Scientific Manuscript database

Improving the scientific understanding of the effectiveness of watershed conservation practices and floodwater-retardation structures to control floods and soil erosion is one of the primary objectives for sediment studies in the upper Washita River Experimental Watersheds. This paper summarizes se...

Does anthropogenic nitrogen enrichment increase organic nitrogen concentrations in runoff from forested and human-dominated watersheds?

USGS Publications Warehouse

Pellerin, B.A.; Kaushal, S.S.; McDowell, W.H.

2006-01-01

Although the effects of anthropogenic nitrogen (N) inputs on the dynamics of inorganic N in watersheds have been studied extensively, "the influence of N enrichment on organic N loss" is not as well understood. We compiled and synthesized data on surface water N concentrations from 348 forested and human-dominated watersheds with a range of N loads (from less than 100 to 7,100 kg N km-2 y-1) to evaluate the effects of N loading via atmospheric deposition, fertilization, and wastewater on dissolved organic N (DON) concentrations. Our results indicate that, on average, DON accounts for half of the total dissolved N (TDN) concentrations from forested watersheds, but it accounts for a smaller fraction of TDN in runoff from urban and agricultural watersheds with higher N loading. A significant but weak correlation (r 2 = 0.06) suggests that N loading has little influence on DON concentrations in forested watersheds. This result contrasts with observations from some plot-scale N fertilization studies and suggests that variability in watershed characteristics and climate among forested watersheds may be a more important control on DON losses than N loading from atmospheric sources. Mean DON concentrations were positively correlated, however, with N load across the entire land-use gradient (r 2 = 0.37, P < 0.01), with the highest concentrations found in agricultural and urban watersheds. We hypothesize that both direct contributions of DON from wastewater and agricultural amendments and indirect transformations of inorganic N to organic N represent important sources of DON to surface waters in human-dominated watersheds. We conclude that DON is an important component of N loss in surface waters draining forested and human-dominated watersheds and suggest several research priorities that may be useful in elucidating the role of N enrichment in watershed DON dynamics. ?? 2006 Springer Science+Business Media, Inc.

Watershed Scale Impacts of Stormwater Green Infrastructure on Hydrology, Nitrogen Fluxes, and Combined Sewer Overflows in the Baltimore, MD and Washington, DC area

NASA Astrophysics Data System (ADS)

Jaffe, P. R.; Pennino, M. J.; McDonald, R.

2016-12-01

Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Baltimore County, MD, Montgomery County, MD, and Washington, DC, were selected based on the availability of data on SGI, water quality, and stream flow. The watershed scale impact of SGI was evaluated by assessing how increased spatial density of SGI correlates with stream hydrology and nitrogen exports over space and time. The most common SGI types were detention ponds (58%), followed by marshes (12%), sand filters (9%), wet ponds (7%), infiltration trenches (4%), and rain gardens (2%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI (>10% SGI) have 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff than watersheds with lower SGI. Watersheds with more SGI also show 44% less NO3- and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in combined sewer overflows in watersheds with greater SGI. Based on specific SGI types, infiltration trenches (R2 = 0.35) showed the strongest correlation with hydrologic metrics, likely due to their ability to attenuate flow, while bioretention (R2 = 0.19) and wet ponds (R2 = 0.12) showed stronger relationships with nitrogen compared to other SGI types, possibly due to greater denitrification in these sites. When comparing individual watersheds over time, increases in SGI corresponded to non-significant reductions in hydrologic flashiness and combined sewer overflows compared to watersheds with no change in SGI. This study shows that while implementation of SGI is ongoing, some regions are beginning to have enough SGI to see significant impacts on hydrology and water quality at the watershed scale.

Genesee River Basin Study. Volume 1. Main Report.

DTIC Science & Technology

1988-06-01

Watersheds" by the U.S. Department of Agriculture, Soil Conservation Service, was prepared in June and October 1974. The report entitled "Dyke Creek...Watershed Preliminary Evaluation" by the U.S. Department of Agriculture, Soil Conservation Service, was prepared in December 1974. The report recommended... Soil Conservation Service prepared the draft report "Dyke Creek, P.L. 566 Watershed Project, Watershed Plan and Environmental Assessment" in June

Morphometric Analysis to Prioritize Sub-Watershed for Flood Risk Assessment in Central Karakoram National Park Using Gis/rs Approach

NASA Astrophysics Data System (ADS)

Syed, N. H.; Rehman, A. A.; Hussain, D.; Ishaq, S.; Khan, A. A.

2017-11-01

Morphometric analysis is vital for any watershed investigation and it is inevitable for flood risk assessment in sub-watershed basins. Present study undertaken to carry out critical evaluation and assessment of sub watershed morphological parameters for flood risk assessment of Central Karakorum National Park (CKNP), where Geographical information system and remote sensing (GIS & RS) approach used for quantifying the parameter and mapping of sub watershed units. ASTER DEM used as a geo-spatial data for watershed delineation and stream network. Morphometric analysis carried out using spatial analyst tool of ArcGIS 10.2. The parameters included were bifurcation ratio (Rb), Drainage Texture (Rt), Circulatory ratio (Rc), Elongated ratio (Re), Drainage density (Dd), Stream Length (Lu), Stream order (Su), Slope and Basin length (Lb) have calculated separately. The analysis revealed that the stream order varies from order 1 to 6 and the total numbers of stream segments of all orders were 52. Multi criteria analysis process used to calculate the risk factor. As an accomplished result, map of sub watershed prioritization developed using weighted standardized risk factor. These results helped to understand sensitivity of flush floods in different sub watersheds of the study area and leaded to better management of the mountainous regions in prospect of flush floods.

Impacts of urban sprawl on the area of downtown lakes in a highly developing city on central China

NASA Astrophysics Data System (ADS)

Zhang, W.; Zhang, Y.

2016-12-01

Wuhan city in central China is full of water resources and numerous lakes are located. Downtown lakes have significant ecological value and ornamental value for urban inhabitants in Wuhan. Under the rapid process of urban sprawl, downtown lakes are occupied by impervious areas. This research uses Landsat images to extract land uses from 1991 to 2013 in Wuhan city , and attempts to find out how urban sprawl affects the water body area decline in space. Two largest downtown lakes in Wuhan city, Donghu Lake located in central city and Tangxunhu Lake located in suburbs, are taken as case study area. A direction change index (DCI) is proposed to evaluate the changes of a specific land use in different directions. The results reveal that two downtown lakes are undergoing rapid water body area decline from 1991 to 2013, with decline rate are -0.022 in Donghu watershed and -0.011 in Tangxunhu watershed. 68.26% and 62.50% of the reduced water body is occupied by built-up land in Donghu watershed and Tangxunhu watershed, respectively. According to DCI, the water body reduce is highly correlated with built-up land increase in all direction. Moreover, it is found that in the Donghu watershed the north-west part suffered significant water body area decline, which is close to central city. While in Tangxunhu watershed, the area of water body declined in north-west, south-west and north-east part, and the area obstructed from central city by the lake was suffering less water body area decline. It is concluded that the water body area of downtown lakes are highly affected by the process of urban sprawl, and the lakes in central districts trends to suffer higher descend than that of the downtown lake located in suburbs. Meanwhile, even for the same downtown lake, the area orientating and close to the central city may suffer more rapid decline than the area that does not orientate to the central city.

Comparison of storm response of streams in small, unmined and valley-filled watersheds, 1999-2001, Ballard fork, West Virginia

USGS Publications Warehouse

Messinger, Terence

2003-01-01

During storms when rainfall intensity exceeded about 1 inch per hour, peak unit runoff from the Unnamed Tributary (surface-mined and filled) Watershed exceeded peak unit runoff from the Spring Branch (unmined) Watershed in the Ballard Fork Watershed in southern West Virginia. During most storms, those with intensity less than about 1 inch per hour, peak unit (area-normalized) flows were greater from the Spring Branch Watershed than the Unnamed Tributary Watershed. One storm that produced less than an inch of rain before flow from the previous storm had receded caused peak unit flow from the Unnamed Tributary Watershed to exceed peak unit flow from the Spring Branch Watershed. Peak unit flow was usually similar in Spring Branch and Ballard Fork. Peak unit flows are expected to decrease with increasing watershed size in homogeneous watersheds; drainage area and proportion of the three watersheds covered by valley fills are 0.19 square mile (mi?) and 44 percent for the Unnamed Tributary Watershed, 0.53 mi? and 0 percent for the Spring Branch Watershed, and 2.12 mi? and 12 percent for the Ballard Fork Watershed. Following all storms with sufficient rainfall intensity, about 0.25 inches per hour, the storm hydrograph from the Unnamed Tributary Watershed showed a double peak, as a sharp initial rise was followed by a decrease in flow and then a delayed secondary peak of water that had apparently flowed through the valley fill. Hortonian (excess overland) flow may be important in the Unnamed Tributary Watershed during intense storms, and may cause the initial peak on the rising arm of storm hydrographs; the water composing the initial peaks may be conveyed by drainage structures on the mine. Ballard Fork and Spring Branch had hydrographs with single peaks, typical of elsewhere in West Virginia. During all storms with 1-hour rainfall greater than 0.75 inches or 24-hour rainfall greater than 1.75 inches during which all stream gages recorded a complete record, the Unnamed Tributary yielded the most total unit flow. In three selected major storms, total unit flow from the Unnamed Tributary during recessions exceeded storm flow, and its total unit flow was greatest among the streams during all three recessions. Runoff patterns from the mined watershed are influenced by the compaction of soils on the mine, the apparent low maximum rate of infiltration into the valley fill compared to that in the unmined, forested watershed, storage of water in the valley fill, and the absence of interception from trees and leaf litter. No storms during this study produced 1-hour or 24-hour rainfall in excess of the 5-year return period, and streamflow during this study never exceeded a magnitude equivalent to the 1.5-year return period; relative peak unit flow among the three streams in this study could be different in larger storms. Rainfall-runoff relations on altered landscapes are site-specific, and aspects of mining and reclamation practice that affect storm response may vary among mines.

Use of retrospective data to assess ecotoxicological monitoring needs for terrestrial vertebrates residing in Atlantic coast estuaries

USGS Publications Warehouse

Cohen, J.B.; Rattner, B.A.; Golden, N.H.

2003-01-01

The 'Contaminant Exposure and Effects--Terrestrial Vertebrates' (CEE-TV) database contains 4,336 records of ecotoxicological information for free-ranging amphibians, reptiles, birds, and mammals residing in Atlantic and Florida Gulf coast estuaries and their drainages. To identify spatial data gaps, those CEE-TV records for which the specific study location were known (n=2,740) were combined with watershed and wildlife management unit boundaries using Geographic Information Systems software. The U.S. Environmental Protection Agency's Index of Watershed Indicators (IWI), which classifies watersheds based on water quality and their vulnerability to pollution, was used to prioritize these data gaps. Of 136 watersheds in the study area, 15 that are classified by the IWI as having water quality problems or high vulnerability to pollution lacked terrestrial vertebrate ecotoxicological monitoring or research in the past decade. Older studies within some of these watersheds documented high levels of contaminants in wildlife tissues. Of 90 National Wildlife Refuge units, 42 without current data fall within watersheds of concern. Of 40 National Park units larger than 1 km2, 17 without current data fall within watersheds of concern. Issues encountered in this analysis highlighted the need for spatially and temporally replicated field monitoring programs that utilize random sampling. Without data from such studies, it will be difficult to perform unbiased assessments of regional trends in contaminant exposure and effects in terrestrial vertebrates.

Use of retrospective data to assess ecotoxicological monitoring needs for terrestrial vertebrates residing in Atlantic coast estuaries.

PubMed

Cohen, Jonathan B; Rattner, Barnett A; Golden, Nancy H

2003-01-01

The "Contaminant Exposure and Effects-Terrestrial Vertebrates" (CEE-TV) database contains 4,336 records of ecotoxicological information for free-ranging amphibians, reptiles, birds, and mammals residing in Atlantic and Florida Gulf coast estuaries and their drainages. To identify spatial data gaps, those CEE-TV records for which the specific study location were known (n = 2,740) were combined with watershed and wildlife management unit boundaries using Geographic Information Systems software. The US Environmental Protection Agency's Index of Watershed Indicators (IWI), which classifies watersheds based on water quality and their vulnerability to pollution, was used to prioritize these data gaps. Of 136 watersheds in the study area, 15 that are classified by the IWI as having water quality problems or high vulnerability to pollution lacked terrestrial vertebrate ecotoxicological monitoring or research in the past decade. Older studies within some of these watersheds documented high levels of contaminants in wildlife tissues. Of 90 National Wildlife Refuge units, 42 without current data fall within watersheds of concern. Of 40 National Park units larger than 1 km2, 17 without current data fall within watersheds of concern. Issues encountered in this analysis highlighted the need for spatially and temporally replicated field monitoring programs that utilize random sampling. Without data from such studies, it will be difficult to perform unbiased assessments of regional trends in contaminant exposure and effects in terrestrial vertebrates.

Drainage morphometric analysis for assessing form and processes of the watersheds of Pachamalai hills and its adjoinings, Central Tamil Nadu, India

NASA Astrophysics Data System (ADS)

Prabhakaran, A.; Jawahar Raj, N.

2018-03-01

The present study attempts to understand the form and geomorphic/hydrologic processes of the 20 watersheds of the Pachamalai hills and its adjoinings located in Tamil Nadu State of southern India from the analysis of its drainage morphometric characteristics. Survey of India's topographic sheets of 1:50,000 is the data source from which stream networks and watersheds of the study area were demarcated followed by the analysis of their morphometric characteristics using ArcGIS software. The results of the analysis formed the basis for deducing the form and processes of the watersheds of the study area. The form of the watersheds inferred from the analysis includes shape, length, slope steepness and length, degree of branching of streams, dissection and elongation of watersheds. The geomorphic/hydrologic processes inferred include denudation rate, potential energy, intensity of erosion, mean annual run off, mean discharge, discharge rate, rock resistivity and infiltration potential, amount of sediment transported, mean annual rainfall, rainfall intensity, lagtime, flash flood potential, flood discharge per unit area, sediment yield and speed of the water flow in the streams. The understanding of variations of form and processes mentioned can be used towards prioritizing the watersheds for development, management and conservation planning.

A study of water balances over the Tigris-Euphrates watershed

NASA Astrophysics Data System (ADS)

Kavvas, M. L.; Chen, Z. Q.; Anderson, M. L.; Ohara, N.; Yoon, J. Y.; Xiang, Fu

Tigris-Euphrates watershed was considered as one hydrologic unit, and a scientific assessment of its water resources was performed. Accordingly, (a) an inventory of land use/land cover, vegetation, soils, and existing hydraulic structures in the watershed was performed; (b) a regional hydroclimate model, RegHCM-TE, of the watershed was developed, and used to reconstruct historical precipitation data, to perform land hydrologic water balance computations for infiltration, soil water storage, actual evapotranspiration, direct runoff as input for streamflow computations, and to estimate irrigation water demands; and (c) a hydrologic model was developed to route streamflows within the river network of the watershed. Also, an algorithm for operating the reservoirs within the watershed was developed, and utilized to perform dynamic water balance studies under various water supply/demand scenarios to establish efficient utilization of the watershed’s water resources to meet the water demands of the riparian countries in the basin. Within this dynamic water balance framework, it is possible to assess and quantify the effect of sequential river flows on the chronologically sequential water balances over the watershed. The water balance study for the natural flow conditions prior to the development of large dams within TE basin, during the 1957-1969 critical period is presented.

Traditional and Host-Associated Fecal Indicator Bacterial Patterns in Southern California Watersheds: Field Source Identification Studies and Laboratory Microcosms Investigating Presence and Persistence in Water and Sediments

NASA Astrophysics Data System (ADS)

Mika, Kathryn Beth

Overall, recreational beach water quality remains an issue of concern in Southern California and across the globe. Many factors come into play when determining water quality, including physical issues such as the myriad sources that contribute pollution to the site and financial and political issues that control the way water quality is monitored and determined. Current national regulations require the monitoring of fecal indicator bacteria in order to determine recreational water quality. However, it is also important to identify biological and geographical sources of pollution to consistently impaired locations. A commonly applied approach to meet the goals of source identification is to sample sites that have been high in FIB for further study. A tiered approach such as this, however, assumes a correlation between FIB and the sources of interest in the watershed. The research described in this dissertation tests this assumption in two Southern California watersheds, Santa Monica Canyon and Ventura Harbor. In both cases, a tiered approach to sampling using FIB as a first tier to guide sampling would have failed to identify sources of human fecal pollution (as identified by the presence of the human-associated Bacteroides marker HF183). Every watershed is a distinct environment that has different potential sources of bacteria and many factors contributing to the persistence of the bacteria. Rather than attempting to apply an indicator that has worked as a first tier in other watersheds, it would be better to have as a first tier an in-depth study of the watershed using historical data or local experts to provide information on the most likely sources of pollution in the watershed. Using this information it would be possible to design a study using FIB and one or more source-associated parameters to identify specific sources of pollution in the watershed. In addition, sampling FIB and other parameters such as HF183 allow the application of other microbial source tracking tools including indicator ratios and detection frequencies. Source identification studies do not necessarily have to be long-term to identify consistent sources of pollution. For example, within the first four months of sampling at Ventura, the increased frequency of detection of HF183 at the Marina Dock sample location was apparent, and a dry weather influx of HF183 was seen in the Keys channels. In addition to the many sources of FIB to the environment such as storm drains, leaking sewers, and wildlife, there are important environmental reservoirs such as sand and seaweed that can foster FIB growth and persistence in the environment. As such, it is important to understand the effect of different factors on the ability of bacteria to survive and persist in these reservoirs. Microcosm experiments conducted during the course of this dissertation research found that in dry beach sand (0.1% moisture), the addition of moisture was detrimental to the survival of the indicators studied (General Bacteroidales, E. coli, and enterococci). While increased moisture was not always detrimental to bacterial survival, these results point to the ability of bacteria to persist for long periods of time in beach environments under in-situ conditions (including dry sand). These findings point to the importance of understanding the behavior of indicator bacteria populations that have evolved to survive in environmental conditions so that their potential impact on overlying or adjacent water quality can be better understood. In summation, results from this research point to the importance of selecting indicators and sample locations that are most relevant to watershed concerns rather than using a first tier such as FIB to preferentially select sites for further analysis. Measuring a marker for human fecal pollution in both watershed studies provided useful information for potential human inputs that would have been missed if sites were chosen based on high FIB levels. In addition it is very important to understand the contribution of different reservoirs, such as sand, in the study area to the observed microbial pollution. Overall, these results point to the need for further examination of the ability of bacteria to survive under various environmental conditions in both water and sand, using both environmental microbial populations and populations from likely sources such as human sewage.

Controlling factors of soil selenium distribution in a watershed in Se-enriched and longevity region of South China.

PubMed

Shao, Ya; Cai, Chongfa; Zhang, Haitao; Fu, Wei; Zhong, Xuemei; Tang, Shen

2018-05-10

Selenium (Se) is an essential nutritional element for human beings. Many studies have been conducted on concentration and distribution patterns of soil Se in low Se, Se-enriched, and selenosis areas; however, soil Se has not been systematically studied in a watershed, especially in Se-enriched longevity region and karst area in South China. This study is carried out to explore the controlling factors of Se-enriched soils in Baishou river tributary watershed, where soils are Se-enriched, and local people have the phenomenon of longevity. The area-weighted average rock Se concentration in the watershed is 0.054 mg/kg, and there are no significant differences in rock Se concentration between different strata and between different lithological rocks. The area-weighted average concentration of Se in soils (0-20 cm) is 0.80 mg/kg, and the soil Se concentration is of high level in the watershed. Soil Se concentration decreases from upstream to downstream in the watershed, and significantly correlated with elevation. Climate is the main factor causing high content of soil Se in the watershed which lacks black rock series. The difference of clastic and carbonate parent materials in soil forming process and the physical and chemical properties (pH, OM, etc.) are the main reasons for the spatial variation of Se distribution in the watershed. The research will be beneficial to the development and utilization of Se-enriched soil in Se-enriched area.

Disentangling the response of streamflow to forest management and climate

NASA Astrophysics Data System (ADS)

Dymond, S.; Miniat, C.; Bladon, K. D.; Keppeler, E.; Caldwell, P. V.

2016-12-01

Paired watershed studies have showcased the relationships between forests, management, and streamflow. However, classical analyses of paired-watershed studies have done little to disentangle the effects of management from overarching climatic signals, potentially masking the interaction between management and climate. Such approaches may confound our understanding of how forest management impacts streamflow. Here we use a 50-year record of streamflow and climate data from the Caspar Creek Experimental Watersheds (CCEW), California, USA to separate the effects of forest management and climate on streamflow. CCEW has two treatment watersheds that have been harvested in the past 50 years. We used a nonlinear mixed model to combine the pre-treatment relationship between streamflow and climate and the post-treatment relationship via an interaction between climate and management into one equation. Our results show that precipitation and potential evapotranspiration alone can account for >95% of the variability in pre-treatment streamflow. Including management scenarios into the model explained most of the variability in streamflow (R2 > 0.98). While forest harvesting altered streamflow in both of our modeled watersheds, removing 66% of the vegetation via selection logging using a tractor yarding system over the entire watershed had a more substantial impact on streamflow than clearcutting small portions of a watershed using cable-yarding. These results suggest that forest harvesting may result in differing impacts on streamflow and highlights the need to incorporate climate into streamflow analyses of paired-watershed studies.

Variation of Runoff and Precipitation in the Hekou-Longmen Region of the Yellow River Based on Elasticity Analysis

PubMed Central

Li, Erhui; Mu, Xingmin; Zhao, Guangju; Gao, Peng; Shao, Hongbo

2014-01-01

Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010), Huangfuchuan watershed (from 1954 to 2010), and Yanhe watershed (from 1952 to 2010) in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P = 0.01) while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000–2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed. PMID:24955424

Variation of runoff and precipitation in the Hekou-Longmen region of the Yellow River based on elasticity analysis.

PubMed

Li, Erhui; Mu, Xingmin; Zhao, Guangju; Gao, Peng; Shao, Hongbo

2014-01-01

Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010), Huangfuchuan watershed (from 1954 to 2010), and Yanhe watershed (from 1952 to 2010) in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P = 0.01) while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000-2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed.

Improving watershed management practices in humid regions

USDA-ARS?s Scientific Manuscript database

Understanding the basic hydrology and erosion is vital for effective management and utilization of water resources and soil conservation planning. To improve the understanding we used watershed studies on three continents. The results show that in well vegetated (sub) humid and temperate watersheds ...

An approach to measure parameter sensitivity in watershed hydrological modelling

EPA Science Inventory

Hydrologic responses vary spatially and temporally according to watershed characteristics. In this study, the hydrologic models that we developed earlier for the Little Miami River (LMR) and Las Vegas Wash (LVW) watersheds were used for detail sensitivity analyses. To compare the...

AN ARCGIS TOOL FOR CREATING POPULATIONS OF WATERSHEDS

EPA Science Inventory

For the Landscape Investigations for Pesticides Study in the Midwest, the goal is to sample a representative subset of watersheds selected statistically from a target population of watersheds within the glaciated corn belt. This area stretches from Ohio to Iowa and includes parts...

A METHODOLOGY FOR ESTIMATING UNCERTAINTY OF A DISTRIBUTED HYDROLOGIC MODEL: APPLICATION TO POCONO CREEK WATERSHED

EPA Science Inventory

Utility of distributed hydrologic and water quality models for watershed management and sustainability studies should be accompanied by rigorous model uncertainty analysis. However, the use of complex watershed models primarily follows the traditional {calibrate/validate/predict}...

An inexact log-normal distribution-based stochastic chance-constrained model for agricultural water quality management

NASA Astrophysics Data System (ADS)

Wang, Yu; Fan, Jie; Xu, Ye; Sun, Wei; Chen, Dong

2018-05-01

In this study, an inexact log-normal-based stochastic chance-constrained programming model was developed for solving the non-point source pollution issues caused by agricultural activities. Compared to the general stochastic chance-constrained programming model, the main advantage of the proposed model is that it allows random variables to be expressed as a log-normal distribution, rather than a general normal distribution. Possible deviations in solutions caused by irrational parameter assumptions were avoided. The agricultural system management in the Erhai Lake watershed was used as a case study, where critical system factors, including rainfall and runoff amounts, show characteristics of a log-normal distribution. Several interval solutions were obtained under different constraint-satisfaction levels, which were useful in evaluating the trade-off between system economy and reliability. The applied results show that the proposed model could help decision makers to design optimal production patterns under complex uncertainties. The successful application of this model is expected to provide a good example for agricultural management in many other watersheds.

Long-term monitoring of UK river basins: the disconnections between the timescales of hydrological processes and watershed management planning

NASA Astrophysics Data System (ADS)

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

2016-12-01

The UK has a wealth of hydrological monitoring data that has both good coverage in space since the early 1970s, and also a few locations where records have been kept continuously for almost 150 years. Such datasets offer unique opportunities for the hydrologist to consider how the concepts of stationarity, change, and definitions of "baseline" resources should be used to shape how we build models of these systems, and how we devise appropriate and sustainable watershed management strategies. In this paper we consider some of the UK's longest hydrological and biogeochemical records, to explore how long records can be used to shape such understanding and, in some cases, how they can be used to identify new modes of behaviour that need to be incorporated into management planning, from the scale of individual watersheds right up to the national scale. We also consider how key timescales of hydrological responses that are evident within the data may pose major problems for watershed management unless appropriate attention is paid to the potential impacts of processes that work over decadal timescales - much longer than sub-decadal water industry investment cycles or short-term projects for watershed management planning. We use our long-term records to show how key processes can be identified, and to illustrate how careful interpretation of shorter term records will improve decision-making for water resource management.

Controls on mercury and methylmercury deposition for two watersheds in Acadia National Park, Maine.

PubMed

Johnson, K B; Haines, T A; Kahl, J S; Norton, S A; Amirbahman, Aria; Sheehan, K D

2007-03-01

Throughfall and bulk precipitation samples were collected for two watersheds at Acadia National Park, Maine, from 3 May to 16 November 2000, to determine which landscape factors affected mercury (Hg) deposition. One of these watersheds, Cadillac Brook, burned in 1947, providing a natural experimental design to study the effects of forest type on deposition to forested watersheds. Sites that face southwest received the highest Hg deposition, which may be due to the interception of cross-continental movement of contaminated air masses. Sites covered with softwood vegetation also received higher Hg deposition than other vegetation types because of the higher scavenging efficiency of the canopy structure. Methyl mercury (MeHg) deposition was not affected by these factors. Hg deposition, as bulk precipitation and throughfall was lower in Cadillac Brook watershed (burned) than in Hadlock Brook watershed (unburned) because of vegetation type and watershed aspect. Hg and MeHg inputs were weighted by season and vegetation type because these two factors had the most influence on deposition. Hg volatilization was not determined. The total Hg deposition via throughfall and bulk precipitation was 9.4 microg/m(2)/year in Cadillac Brook watershed and 10.2 microg/m(2)/year in Hadlock Brook watershed. The total MeHg deposition via throughfall and bulk precipitation was 0.05 microg/m(2)/year in Cadillac Brook watershed and 0.10 microg/m(2)/year in Hadlock Brook watershed.

Decadal water quality variations at three typical basins of Mekong, Murray and Yukon

NASA Astrophysics Data System (ADS)

Khan, Afed U.; Jiang, Jiping; Wang, Peng

2018-02-01

Decadal distribution of water quality parameters is essential for surface water management. Decadal distribution analysis was conducted to assess decadal variations in water quality parameters at three typical watersheds of Murray, Mekong and Yukon. Right distribution shifts were observed for phosphorous and nitrogen parameters at the Mekong watershed monitoring sites while left shifts were noted at the Murray and Yukon monitoring sites. Nutrients pollution increases with time at the Mekong watershed while decreases at the Murray and Yukon watershed monitoring stations. The results implied that watershed located in densely populated developing area has higher risk of water quality deterioration in comparison to thinly populated developed area. The present study suggests best management practices at watershed scale to modulate water pollution.

A case study of the relative effects of power plant nitrogen oxides and sulfur dioxide emission reductions on atmospheric nitrogen deposition.

PubMed

Vijayaraghavan, Krish; Seigneur, Christian; Bronson, Rochelle; Chen, Shu-Yun; Karamchandani, Prakash; Walters, Justin T; Jansen, John J; Brandmeyer, Jo Ellen; Knipping, Eladio M

2010-03-01

The contrasting effects of point source nitrogen oxides (NOx) and sulfur dioxide (SO2) air emission reductions on regional atmospheric nitrogen deposition are analyzed for the case study of a coal-fired power plant in the southeastern United States. The effect of potential emission reductions at the plant on nitrogen deposition to Escambia Bay and its watershed on the Florida-Alabama border is simulated using the three-dimensional Eulerian Community Multiscale Air Quality (CMAQ) model. A method to quantify the relative and individual effects of NOx versus SO2 controls on nitrogen deposition using air quality modeling results obtained from the simultaneous application of NOx and SO2 emission controls is presented and discussed using the results from CMAQ simulations conducted with NOx-only and SO2-only emission reductions; the method applies only to cases in which ambient inorganic nitrate is present mostly in the gas phase; that is, in the form of gaseous nitric acid (HNO3). In such instances, the individual effects of NOx and SO2 controls on nitrogen deposition can be approximated by the effects of combined NOx + SO2 controls on the deposition of NOy, (the sum of oxidized nitrogen species) and reduced nitrogen species (NHx), respectively. The benefit of controls at the plant in terms of the decrease in nitrogen deposition to Escambia Bay and watershed is less than 6% of the overall benefit due to regional Clean Air Interstate Rule (CAIR) controls.

Riparian and upland vegetation on the Kings River Experimental Watershed, Sierra Nevada, California

Treesearch

Christopher R. Dolanc; Carolyn T. Hunsaker

2007-01-01

The Kings River Experimental Watershed (KREW) is a watershed-level study on headwater streams in the Sierra Nevada, California. Eight perennial streams, from 1500 m (4920 ft) to 2490 m (8170 ft) elevation, have been instrumented and collecting data since 2002. Component research areas of the study include stream flow, water chemistry, sediment, soil chemistry, stream...

Urban 5th Graders Conceptions during a Place-Based Inquiry Unit on Watersheds

ERIC Educational Resources Information Center

Endreny, Anna Henderson

2010-01-01

This study aimed to determine how 33 urban 5th grade students' science conceptions changed during a place-based inquiry unit on watersheds. Research on watershed and place-based education was used as a framework to guide the teaching of the unit as well as the research study. A teacher-researcher designed the curriculum, taught the unit and…

What Is a Watershed? Implications of Student Conceptions for Environmental Science Education and the National Science Education Standards

ERIC Educational Resources Information Center

Shepardson, Daniel P.; Wee, Bryan; Priddy, Michelle; Schellenberger, Lauren; Harbor, Jon

2007-01-01

The purpose of this study was to investigate students' conceptions about watersheds. Specifically: (1) What are students' conceptions of a watershed? and (2) In what ways might students' conceptions vary by grade level and community setting? This study was descriptive in nature and reflected a cross-age design involving the collection of…

Rainfall, soil moisture, and runoff dynamics in New Mexico pinon-juniper woodland watersheds

Treesearch

Carlos Ochoa; Alexander Fernald; Vincent Tidwell

2008-01-01

Clearing trees in pinon-juniper woodlands may increase grass cover and infiltration, leading to reduced surface runoff and erosion. This study was conducted to evaluate pinon-juniper hydrology conditions during baseline data collection in a paired watershed study. We instrumented six 1.0 to 1.3 ha experimental watersheds near Santa Fe, NM to collect rainfall, soil...

Emerald Lake Watershed study: Introduction and site description

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

Tonnessen, K.A.

1991-07-01

The Emerald Lake Watershed study was organized to investigate the effects of acidic deposition on high-elevation watersheds and surface waters of the Sierra Nevada, California. Some of the results of this comprehensive study of aquatic and terrestrial ecosystems at a small, headwater basin are presented in four papers in this series. The watershed study site is in Sequoia National Park, on the western slope of the Sierra Nevada. This glacial cirque is located in the upper Marble Fork of the Kaweah River. This 120-ha watershed ranges from Alta Peak (3,416 m) down to Emerald Lake (2,400 m). Most of themore » watershed surface area is exposed granite and granodiorite rocks, with limited coverage (about 20%) by thin, acidic soils. The hydrology of the basin is dominated by snowmelt runoff during March-June. Emerald Lake, a glacial tarn, is 2.72 ha in area, with a maximum depth of 10.5 m. Surface waters are poorly buffered and dominated by calcium and bicarbonate. Most of the yearly precipitation falls as dilute snow (pH5.2-5.4), with acidic rain storms sampled during May-October.« less

Nutrient exports from watersheds with varying septic system densities in the North Carolina Piedmont.

PubMed

Iverson, G; Humphrey, C P; O'Driscoll, M A; Sanderford, C; Jernigan, J; Serozi, B

2018-04-01

Septic systems (SSs) have been shown to be a significant source of nitrogen and phosphorus to nutrient-sensitive coastal surface and groundwaters. However, few published studies have quantified the effects of SSs on nutrient inputs to water supply watersheds in the Piedmont region of the USA. This region consists of rolling hills at the surface underlain by clayey soils. There are nearly 1 million SSs in this region, which accounts for approximately 50% of all SSs in North Carolina. The goal of this study was to determine if significant differences in nutrient concentrations and exports exist between Piedmont watersheds with different densities of SSs. Water quality was assessed in watersheds with SSs (n = 11) and a sewer and a forested watershed, which were designated as controls. Stream flow and environmental readings were recorded and water samples were collected from the watersheds from January 2015-December 2016. Additional samples were collected from sand filter watersheds in April 2015-March 2016 to compare to septic and control watersheds. Samples were analyzed for total dissolved nitrogen (TDN) and orthophosphate (PO 4 -P). Results indicated that watersheds served by a high-density (HD) of SSs (4.9 kg-N yr -1 ha -1 ; 0.2 kg-P yr -1 ha -1 ) exported more than double the median masses of TDN and PO 4 -P, respectively, relative to low-density (1.0 kg-N yr -1 ha -1 ; <0.1 kg-P yr -1 ha -1 ) and control watersheds (1.4 kg-N yr -1 ha -1 ; <0.1 kg-P yr -1 ha -1 ) during baseflow. Isotopic analysis indicated that wastewater was the most likely source of nitrate-N in HD watersheds. In all other watersheds, isotopic results suggested non-wastewater sources as the dominant nitrate-N provider. These findings indicated that SS density was a significant factor in the delivery of septic-derived nutrients to these nutrient-sensitive, water supply watersheds of the North Carolina Piedmont. Copyright © 2018 Elsevier Ltd. All rights reserved.

Relationship between landscape characteristics and surface water quality.

PubMed

Chang, C L; Kuan, W H; Lui, P S; Hu, C Y

2008-12-01

The effects of landscape characteristics on surface water quality were evaluated in terms of land-use condition, soil type and slope. The case area, the Chichiawan stream in the Wulin catchment in Taiwan, is Formosan landlocked salmon's natural habitat. Due to the agriculture behavior and mankind's activities, the water and environmental quality has gradually worsened. This study applied WinVAST model to predict hydrological responses and non-point source pollution (NPSP) exports in the Wulin catchment. The land-use condition and the slope of land surface in a catchment are major effect factors for watershed responses, including flows and pollutant exports. This work discussed the possible variation of watershed responses induced by the change of land-use condition, soil type and slope, etc. The results show that hydrological responses are highly relative to the value of Curve Number (CN); Pollutant exports have large relation to the average slope of the land surface in the Wulin catchment.

Incorporating uncertainty in watershed management decision-making: A mercury TMDL case study

USGS Publications Warehouse

Labiosa, W.; Leckie, J.; Shachter, R.; Freyberg, D.; Rytuba, J.; ,

2005-01-01

Water quality impairment due to high mercury fish tissue concentrations and high mercury aqueous concentrations is a widespread problem in several sub-watersheds that are major sources of mercury to the San Francisco Bay. Several mercury Total Maximum Daily Load regulations are currently being developed to address this problem. Decisions about control strategies are being made despite very large uncertainties about current mercury loading behavior, relationships between total mercury loading and methyl mercury formation, and relationships between potential controls and mercury fish tissue levels. To deal with the issues of very large uncertainties, data limitations, knowledge gaps, and very limited State agency resources, this work proposes a decision analytical alternative for mercury TMDL decision support. The proposed probabilistic decision model is Bayesian in nature and is fully compatible with a "learning while doing" adaptive management approach. Strategy evaluation, sensitivity analysis, and information collection prioritization are examples of analyses that can be performed using this approach.

Effects of mountain agriculture on nutrient cycling at upstream watersheds

NASA Astrophysics Data System (ADS)

Lin, T.-C.; Shaner, P. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

2015-05-01

The expansion of agriculture to rugged mountains can exacerbate negative impacts of agriculture activities on ecosystem function. In this study, we monitored streamwater chemistry of four watersheds with varying proportions of agricultural lands (0.4, 3, 17, 22%) and rainfall chemistry of two of the four watersheds at Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportions of agricultural lands, the higher the ion concentrations, which is evident for fertilizer-associated ions (NO3-, K+) but not for ions that are rich in soils (SO42-, Ca2+, Mg2+), suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. The watershed with the highest proportion of agricultural lands had higher concentrations of ions in rainfall and lower nutrient retention capacity (i.e. higher output-input ratio of ions) compared to the relatively pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. Furthermore, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater by more than 70%, indicating that specific landscape configurations help mitigate nutrient enrichment to aquatic systems. We estimated that agricultural lands at our study site contributed approximately 400 kg ha-1 yr-1 of NO3-N and 260 kg ha-1 yr-1 of PO4-P output via streamwater, an order of magnitude greater than previously reported around the globe and can only be matched by areas under intense fertilizer use. Furthermore, we re-constructed watershed nutrient fluxes to show that excessive leaching of N and P, and additional loss of N to the atmosphere via volatilization and denitrification, can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of agriculture activities, especially excessive fertilization, on ecosystem nutrient cycling at mountain watersheds.

Use of fire spread and hydrology models to target forest management on a municipal watershed

Treesearch

Anurag Srivastava; William J. Elliot; Joan Wu

2015-01-01

A small town relies on a forested watershed for its water supply. The forest is at risk for a wildfire. To reduce this risk, some of the watershed will be thinned followed by a prescribed burn. This paper reports on a study to evaluate the impact of such watershed disturbances on water yield. To target management activities, a fire spread model was applied to the...

Scaling relations for watersheds

NASA Astrophysics Data System (ADS)

Fehr, E.; Kadau, D.; Araújo, N. A. M.; Andrade, J. S., Jr.; Herrmann, H. J.

2011-09-01

We study the morphology of watersheds in two and three dimensional systems subjected to different degrees of spatial correlations. The response of these objects to small, local perturbations is also investigated with extensive numerical simulations. We find the fractal dimension of the watersheds to generally decrease with the Hurst exponent, which quantifies the degree of spatial correlations. Moreover, in two dimensions, our results match the range of fractal dimensions 1.10≤df≤1.15 observed for natural landscapes. We report that the watershed is strongly affected by local perturbations. For perturbed two and three dimensional systems, we observe a power-law scaling behavior for the distribution of areas (volumes) enclosed by the original and the displaced watershed and for the distribution of distances between outlets. Finite-size effects are analyzed and the resulting scaling exponents are shown to depend significantly on the Hurst exponent. The intrinsic relation between watershed and invasion percolation, as well as relations between exponents conjectured in previous studies with two dimensional systems, are now confirmed by our results in three dimensions.

Estimating the value of watershed services following forest restoration

NASA Astrophysics Data System (ADS)

Mueller, Julie M.; Swaffar, Wes; Nielsen, Erik A.; Springer, Abraham E.; Lopez, Sharon Masek

2013-04-01

Declining forest health, climate change, and development threaten the sustainability of water supplies in the western United States. While forest restoration may buffer threats to watershed services, funding shortfalls for landscape-scale restoration efforts limit management action. The hydrologic response and reduction in risk to watersheds following forest restoration treatments could create significant nonmarket benefits for downstream water users. Historic experimental watershed studies indicate a significant and positive response from forest thinning by a reallocation of water from evapotranspiration to surface-water yield. In this study, we estimate the willingness to pay (WTP) for improved watershed services for one group of downstream users, irrigators, following forest restoration activities. We find a positive and statistically significant WTP within our sample of 183.50 per household, at an aggregated benefit of more than 400,000 annually for 2181 irrigators. Our benefit estimate provides evidence that downstream irrigators may be willing to invest in landscape-scale forest restoration to maintain watershed services.

Water budgets for selected watersheds in the Delaware River basin, eastern Pennsylvania and western New Jersey

USGS Publications Warehouse

Sloto, Ronald A.; Buxton, Debra E.

2005-01-01

This pilot study, done by the U.S. Geological Survey in cooperation with the Delaware River Basin Commission, developed annual water budgets using available data for five watersheds in the Delaware River Basin with different degrees of urbanization and different geological settings. A basin water budget and a water-use budget were developed for each watershed. The basin water budget describes inputs to the watershed (precipitation and imported water), outputs of water from the watershed (streamflow, exported water, leakage, consumed water, and evapotranspiration), and changes in ground-water and surface-water storage. The water-use budget describes water withdrawals in the watershed (ground-water and surface-water withdrawals), discharges of water in the watershed (discharge to surface water and ground water), and movement of water of water into and out of the watershed (imports, exports, and consumed water). The water-budget equations developed for this study can be applied to any watershed in the Delaware River Basin. Data used to develop the water budgets were obtained from available long-term meteorological and hydrological data-collection stations and from water-use data collected by regulatory agencies. In the Coastal Plain watersheds, net ground-water loss from unconfined to confined aquifers was determined by using ground-water-flow-model simulations. Error in the water-budget terms is caused by missing data, poor or incomplete measurements, overestimated or underestimated quantities, measurement or reporting errors, and the use of point measurements, such as precipitation and water levels, to estimate an areal quantity, particularly if the watershed is hydrologically or geologically complex or the data-collection station is outside the watershed. The complexity of the water budgets increases with increasing watershed urbanization and interbasin transfer of water. In the Wissahickon Creek watershed, for example, some ground water is discharged to streams in the watershed, some is exported as wastewater, and some is exported for public supply. In addition, ground water withdrawn outside the watershed is imported for public supply or imported as wastewater for treatment and discharge in the watershed. A GIS analysis was necessary to quantify many of the water-budget components. The 89.9-square mile East Branch Brandywine Creek watershed in Pennsylvania is a rural watershed with reservoir storage that is underlain by fractured rock. Water budgets were developed for 1977-2001. Average annual precipitation, streamflow, and evapotranspiration were 46.89, 21.58, and 25.88 inches, respectively. Some water was imported (average of 0.68 inches) into the watershed for public-water supply and as wastewater for treatment and discharge; these imports resulted in a net gain of water to the watershed. More water was discharged to East Branch Brandywine Creek than was withdrawn from it; the net discharge resulted in an increase in streamflow. Most ground water was withdrawn (average of 0.25 inches) for public-water supply. Surface water was withdrawn (average of 0.58 inches) for public-water and industrial supply. Discharge of water by sewage-treatment plants and industries (average of 1.22 inches) and regulation by Marsh Creek Reservoir caused base flow to appear an average of 7.2 percent higher than it would have been without these additional sources. On average, 67 percent of the difference was caused by sewage-treatment-plant and industrial discharges, and 33 percent was caused by regulation of the Marsh Creek Reservoir. Water imports, withdrawals, and discharges have been increasing as the watershed becomes increasingly urbanized. The 64-square mile Wissahickon Creek watershed in Pennsylvania is an urban watershed underlain by fractured rock. Water budgets were developed for 1987-98. Average annual precipitation, streamflow, and evapotranspiration were 47.23, 22.24, and 23.12 inches, respectively. The watershed is highly u

Triple Achilles Tendon Rupture: Case Report.

PubMed

Saxena, Amol; Hofer, Deann

We present a case report with 1-year follow-up data of a 57-year-old male soccer referee who had sustained an acute triple Achilles tendon rupture injury during a game. His triple Achilles tendon rupture consisted of a rupture of the proximal watershed region, a rupture of the main body (mid-watershed area), and an avulsion-type rupture of insertional calcific tendinosis. The patient was treated surgically with primary repair of the tendon, including tenodesis with anchors. Postoperative treatment included non-weightbearing for 4 weeks and protected weightbearing until 10 weeks postoperative, followed by formal physical therapy, which incorporated an "antigravity" treadmill. The patient was able to return to full activity after 26 weeks, including running and refereeing, without limitations. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

A Stochastic Multi-Media Model of Microbial Transport in Watersheds

NASA Astrophysics Data System (ADS)

Yeghiazarian, L.; Safwat, A.; Whiteaker, T.; Teklitz, A.; Nietch, C.; Maidment, D. R.; Best, E. P.

2012-12-01

Fecal contamination is the leading cause of surface-water impairment in the US, and fecal pathogens are capable of triggering massive outbreaks of gastrointestinal disease. The difficulty in prediction of water contamination has its roots in the stochastic variability of fecal pathogens in the environment, and in the complexity of microbial dynamics and interactions on the soil surface and in water. To address these challenges, we have developed a stochastic model whereby the transport of microorganisms in watersheds is considered in two broad categories: microorganisms that are attached to mineral or organic substrates in suspended sediment; and unattached microorganisms suspended in overland flow. The interactions of microorganisms with soil particles on the soil surface and in the overland flow lead to transitions of microorganisms between solid and aqueous media. The strength of attachment of microorganisms to soil particles is determined by the chemical characteristics of soils which are highly correlated with the particle size. The particle size class distribution in the suspended sediment is predicted by the Water Erosion Prediction Project (WEPP). The model is integrated with ArcGIS, resulting in a general transport-modeling framework applicable to a variety of biological and chemical surface water contaminants. Simulations are carried out for a case study of contaminant transport in the East Fork Little Miami River Watershed in Ohio. Model results include the spatial probability distribution of microbes in the watershed and can be used for assessment of (1) mechanisms dominating microbial transport, and (2) time and location of highest likelihood of microbial occurrence, thus yielding information on best water sampling strategies.

Toward hydro-social modeling: Merging human variables and the social sciences with climate-glacier runoff models (Santa River, Peru)

NASA Astrophysics Data System (ADS)

Carey, Mark; Baraer, Michel; Mark, Bryan G.; French, Adam; Bury, Jeffrey; Young, Kenneth R.; McKenzie, Jeffrey M.

2014-10-01

Glacier shrinkage caused by climate change is likely to trigger diminished and less consistent stream flow in glacier-fed watersheds worldwide. To understand, model, and adapt to these climate-glacier-water changes, it is vital to integrate the analysis of both water availability (the domain of hydrologists) and water use (the focus for social scientists). Drawn from a case study of the Santa River watershed below Peru’s glaciated Cordillera Blanca mountain range, this paper provides a holistic hydro-social framework that identifies five major human variables critical to hydrological modeling because these forces have profoundly influenced water use over the last 60 years: (1) political agendas and economic development; (2) governance: laws and institutions; (3) technology and engineering; (4) land and resource use; and (5) societal responses. Notable shifts in Santa River water use-including major expansions in hydroelectricity generation, large-scale irrigation projects, and other land and resource-use practices-did not necessarily stem from changing glacier runoff or hydrologic shifts, but rather from these human variables. Ultimately, then, water usage is not predictable based on water availability alone. Glacier runoff conforms to certain expected trends predicted by models of progressively reduced glacier storage. However, societal forces establish the legal, economic, political, cultural, and social drivers that actually shape water usage patterns via human modification of watershed dynamics. This hydro-social framework has widespread implications for hydrological modeling in glaciated watersheds from the Andes and Alps to the Himalaya and Tien Shan, as well as for the development of climate change adaptation plans.

Case studies of riparian and watershed restoration in the southwestern United States—Principles, challenges, and successes

USGS Publications Warehouse

Ralston, Barbara E.; Sarr, Daniel A.; Ralston, Barbara E.; Sarr, Daniel A.

2017-07-18

Globally, rivers and streams are highly altered by impoundments, diversions, and stream channelization associated with agricultural and water delivery needs. Climate change imposes additional challenges by further reducing discharge, introducing variability in seasonal precipitation patterns, and increasing temperatures. Collectively, these changes in a river or stream’s annual hydrology affects surface and groundwater dynamics, fluvial processes, and the linked aquatic and riparian responses, particularly in arid regions. Recognizing the inherent ecosystem services that riparian and aquatic habitats provide, society increasingly supports restoring the functionality of riparian and aquatic ecosystems.Given the wide range in types and scales of riparian impacts, approaches to riparian restoration can range from tactical, short-term, and site-specific efforts to strategic projects and long-term collaborations best pursued at the watershed scale. In the spirit of sharing information, the U.S. Geological Survey’s Grand Canyon Monitoring and Research Center convened a workshop June 23-25, 2015, in Flagstaff, Ariz. for practitioners in restoration science to share general principles, successful restoration practices, and discuss the challenges that face those practicing riparian restoration in the southwestern United States. Presenters from the Colorado River and the Rio Grande basins, offered their perspectives and experiences in restoration at the local, reach and watershed scale. Outcomes of the workshop include this Proceedings volume, which is composed of extended abstracts of most of the presentations given at the workshop, and recommendations or information needs identified by participants. The organization of the Proceedings follows a general progression from local scale restoration to river and watershed scale approaches, and finishes with restoration assessments and monitoring.

Assessment of NASA's Physiographic and Meteorological Datasets as Input to HSPF and SWAT Hydrological Models

NASA Technical Reports Server (NTRS)

Alacron, Vladimir J.; Nigro, Joseph D.; McAnally, William H.; OHara, Charles G.; Engman, Edwin Ted; Toll, David

2011-01-01

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

Comparison of mineral weathering and biomass nutrient uptake in two small forested watersheds underlain by quartzite bedrock, Catoctin Mountain, Maryland, USA

USGS Publications Warehouse

Rice, Karen; Price, Jason R.

2014-01-01

To quantify chemical weathering and biological uptake, mass-balance calculations were performed on two small forested watersheds located in the Blue Ridge Physiographic Province in north-central Maryland, USA. Both watersheds, Bear Branch (BB) and Fishing Creek Tributary (FCT), are underlain by relatively unreactive quartzite bedrock. Such unreactive bedrock and associated low chemical-weathering rates offer the opportunity to quantify biological processes operating within the watershed. Hydrologic and stream-water chemistry data were collected from the two watersheds for the 9-year period from June 1, 1990 to May 31, 1999. Of the two watersheds, FCT exhibited both higher chemical-weathering rates and biomass nutrient uptake rates, suggesting that forest biomass aggradation was limited by the rate of chemical weathering of the bedrock. Although the chemical-weathering rate in the FCT watershed was low relative to the global average, it masked the influence of biomass base-cation uptake on stream-water chemistry. Any differences in bedrock mineralogy between the two watersheds did not exert a significant influence on the overall weathering stoichiometry. The difference in chemical-weathering rates between the two watersheds is best explained by a larger proportion of reactive phyllitic layers within the bedrock of the FCT watershed. Although the stream gradient of BB is about two-times greater than that of FCT, its influence on chemical weathering appears to be negligible. The findings of this study support the biomass nutrient uptake stoichiometry of K1.0Mg1.1Ca0.97 previously determined for the study site. Investigations of the chemical weathering of relatively unreactive quartzite bedrock may provide insight into critical zone processes.

The Complexities of Urban Flood Response: Hydrologic Analyses for the Charlotte, North Carolina Metropolitan Region

NASA Astrophysics Data System (ADS)

Zhou, Z.; Smith, J. A.; Yang, L.; Baeck, M. L.; Liu, S.; Ten Veldhuis, M. C.

2016-12-01

The objective of this study is to develop a broad characterization of land surface and hydrometeorological controls of urban flood frequency. We focus on a collection of "small" urban watersheds (with drainage area ranging from 7 to 200 km2) in Charlotte metropolitan region, North Carolina. These watersheds are contrasted by a variety of land surface properties, such as size, shape, land use/land cover type, impervious coverage pattern, stormwater infrastructure, etc. We carried out empirical analyses based on long-term (15 years), high-resolution (1 15 minutes) instantaneous USGS stream gaging observations as well as bias-corrected, high-resolution (1 km2, 15 min) radar rainfall fields developed through the Hydro-NEXRAD system. Extreme floods in Charlotte urban watersheds are primarily induced by a mixture of flood agents including warm season thunderstorms and tropical cyclones, which ultimately contributed to the upper-tail properties of flood frequency. Flood response in urban watersheds is dominantly dictated by space-time characteristics of rainfall, with relatively significant correlation between runoff and rainfall over more developed watersheds. The roles of antecedent soil moisture and stormwater management infrastructure in flood response are also contrasted across the urban watersheds. The largest variability of flood response, in terms of flood peak and timing, exists in the watershed at a scale of 100 km2. The scale-dependent hydrological response is closely related to the pattern and evolution of urban development across watersheds. Our analyses show the complexities of urban flood response in Charlotte metropolitan region. There are no simple metrics that could perfectly explain the contrasts in flood response across urban watersheds. Future research is directed towards sophisticated modeling studies for a predictive understanding of flood frequency in urban watersheds.

Land Cover Vegetation Changes and Hydrology in Central Texas

NASA Astrophysics Data System (ADS)

Banta, J. R.; Slattery, R.

2013-12-01

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 changes in land cover vegetation (removing the woody vegetation and allowing native grasses to reestablish in the area, commonly referred to as brush management), could potentially change the hydrology in a watershed. The U.S. Geological Survey, in cooperation with several local, State, and Federal agencies, 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 potential 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. Results indicate there are differences in the hydrologic budget and water quality between the reference and treatment watersheds, as well as between pre- and post-brush management periods.

Rehabilitate Newsome Creek Watershed, 2007-2008 Annual Report.

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

Bransford, Stephanie

2009-05-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridgetop approach. The Nez Perce Tribe (NPT) 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 Newsome Creek watershed of the South Fork Clearwater River in 1997. Progress has been made in restoring the watershed through road decommissioning and culvert replacement. Starting in FY 2001 and continuing into themore » present, a major stream restoration effort on the mainstem of Newsome Creek has been pursued. From completing a watershed assessment to a feasibility study of 4 miles of mainstem rehabilitation to carrying that forward into NEPA and a final design, we will begin the effort of restoring the mainstem channel of Newsome Creek to provide spawning and rearing habitat for anadromous and resident fish species. Roads have been surveyed and prioritized for removal or improvement as well as culverts being prioritized for replacement to accommodate fish passage throughout the watershed.« less

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

PubMed

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

2014-09-01

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

Temporal dynamics of groundwater-surface water interaction under the effects of climate change: A case study in the Kiskatinaw River Watershed, Canada

NASA Astrophysics Data System (ADS)

Saha, Gopal Chandra; Li, Jianbing; Thring, Ronald W.; Hirshfield, Faye; Paul, Siddhartho Shekhar

2017-08-01

Groundwater-surface water (GW-SW) interaction plays a vital role in the functioning of riparian ecosystem, as well as sustainable water resources management. In this study, temporal dynamics of GW-SW interaction were investigated under climate change. A case study was chosen for a study area along the Kiskatinaw River in Mainstem sub-watershed of the Kiskatinaw River Watershed, British Columbia, Canada. A physically based and distributed GW-SW interaction model, Gridded Surface Subsurface Hydrologic Analysis (GSSHA), was used. Two different greenhouse gas (GHG) emission scenarios (i.e., A2: heterogeneous world with self-reliance and preservation of local identities, and B1: more integrated and environmental friendly world) of SRES (Special Report on Emissions Scenarios) from Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) were used for climate change study for 2020-2040. The simulation results showed that climate change influences significantly the temporal patterns of GW-SW interaction by generating variable temporal mean groundwater contributions to streamflow. Due to precipitation variability, these contributions varied monthly, seasonally, and annually. The mean annual groundwater contribution to streamflow during 2020-2040 under the A2 and B1 scenarios is expected to be 74.5% (σ = 2%) and 75.6% (σ = 3%), respectively. As compared to that during the base modeling period (2007-2011), the mean annual groundwater contribution to streamflow during 2020-2040 under the A2 and B1 scenarios is expected to decrease by 5.5% and 4.4%, respectively, due to the increased precipitation (on average 6.7% in the A2 and 4.8% in the B1 scenarios) and temperature (on average 0.83 °C in the A2 and 0.64 °C in the B1 scenarios). The results obtained from this study will provide useful information in the long-term seasonal and annual water extractions from the river for future water supply, as well as for evaluating the ecological conditions of the stream, which will be beneficial to aquatic ecosystems.

Improving understanding of mixed-land-use watershed suspended sediment regimes: Mechanistic progress through high-frequency sampling.

PubMed

Kellner, Elliott; Hubbart, Jason A

2017-11-15

Given the importance of suspended sediment to biogeochemical functioning of aquatic ecosystems, and the increasing concern of mixed-land-use effects on pollutant loading, there is an urgent need for research that quantitatively characterizes spatiotemporal variation of suspended sediment dynamics in contemporary watersheds. A study was conducted in a representative watershed of the central United States utilizing a nested-scale experimental watershed design, including five gauging sites (n=5) partitioning the catchment into five sub-watersheds. Hydroclimate stations at gauging sites were used to monitor air temperature, precipitation, and stream stage at 30-min intervals during the study (Oct. 2009-Feb. 2014). Streamwater grab samples were collected four times per week, at each site, for the duration of the study (Oct. 2009-Feb. 2014). Water samples were analyzed for suspended sediment using laser particle diffraction. Results showed significant differences (p<0.05) between monitoring sites for total suspended sediment concentration, mean particle size, and silt volume. Total concentration and silt volume showed a decreasing trend from the primarily agricultural upper watershed to the urban mid-watershed, and a subsequent increasing trend to the more suburban lower watershed. Conversely, mean particle size showed an opposite spatial trend. Results are explained by a combination of land use (e.g. urban stormwater dilution) and surficial geology (e.g. supply-controlled spatial variation of particle size). Correlation analyses indicated weak relationships with both hydroclimate and land use, indicating non-linear sediment dynamics. Suspended sediment parameters displayed consistent seasonality during the study, with total concentration decreasing through the growing season and mean particle size inversely tracking air temperature. Likely explanations include vegetation influences and climate-driven weathering cycles. Results reflect unique observations of spatiotemporal variation of suspended sediment particle size class. Such information is crucial for land and water resource managers working to mitigate aquatic ecosystem degradation and improve water resource sustainability in mixed-land-use watersheds globally. Copyright © 2017 Elsevier B.V. All rights reserved.

Spatial prediction of water quality variables along a main river channel, in presence of pollution hotspots.

PubMed

Rizo-Decelis, L D; Pardo-Igúzquiza, E; Andreo, B

2017-12-15

In order to treat and evaluate the available data of water quality and fully exploit monitoring results (e.g. characterize regional patterns, optimize monitoring networks, infer conditions at unmonitored locations, etc.), it is crucial to develop improved and efficient methodologies. Accordingly, estimation of water quality along fluvial ecosystems is a frequent task in environment studies. In this work, a particular case of this problem is examined, namely, the estimation of water quality along a main stem of a large basin (where most anthropic activity takes place), from observational data measured along this river channel. We adapted topological kriging to this case, where each watershed contains all the watersheds of the upstream observed data ("nested support effect"). Data analysis was additionally extended by taking into account the upstream distance to the closest contamination hotspot as an external drift. We propose choosing the best estimation method by cross-validation. The methodological approach in spatial variability modeling may be used for optimizing the water quality monitoring of a given watercourse. The methodology presented is applied to 28 water quality variables measured along the Santiago River in Western Mexico. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of nonpoint source nutrient loading in the Patuxent River basin, Maryland

USGS Publications Warehouse

Preston, S.D.

1997-01-01

Study of nonpoint-source (NPS) nutrient loading in Maryland has focused on the Patuxent watershed because of its importance and representativeness of conditions in the State. Evaluation of NPS nutrient loading has been comprehensive and has included long-term monitoring, detailed watershed modeling, and synoptic sampling studies. A large amount of information has been compiled for the watershed and that information is being used to identify primary controls and efficient management strategies for NPS nutrient loading. Results of the Patuxent NPS study have identified spatial trends in water quality that appear to be related to basin charcteristics such as land use, physiography, andgeology. Evaluation of the data compiled by the study components is continuing and is expected to provide more detailed assessments of the reasons for spatial trends. In particular, ongoing evaluation of the watershed model output is expected to provide detailed information on the relative importance of nutrient sources and transport pathways across the entire watershed. Planned future directions of NPS evaluation in the State of Maryland include continued study of water quality in the Patuxent watershed and a shift in emphasis to a statewide approach. Eventually, the statewide approach will become the primary approach usedby the State to evaluate NPS loading. The information gained in the Patuxent study and the tools developed will represent valuable assets indeveloping the statewide NPS assessment program.

A WATERSHED-LEVEL APPROACH TO STUDY THE PUTATIVE RELATIONSHIPS BETWEEN LANDUSE CHANGE AND SURFACE WATER FLOW ALTERATION

EPA Science Inventory

Inter-generationally prudent management of watershed resources will require attention to the interdependence between shifting landuse distributions and their effects on watershed hydrology. Development and increased proportion of impervious surface area has been found to alte lan...

Geomorphic predictors of riparian vegetation in small mountain watersheds

Treesearch

Blake M. Engelhardt; Jeanne C. Chambers; Peter J. Weisberg

2015-01-01

Hydrogeomorphic processes operating at watershed, process zone and site scales influence the distribution of riparian vegetation. However, most studies examining the relationships between hydrogeomorphic processes and riparian vegetation are conducted at site scales. We quantified the relative importance of watershed, process zone and site geomorphic characteristics...

Hydrologic responses of large drainage to clearcutting: a modeling perspective

Treesearch

J. Duan; R. R. Ziemer; G. E. Grant

1997-01-01

As forested watersheds become more intensively managed, it is increaseingly important to understand the range of hydrologic impacts in order to maintain the biodiversity and sustainability of these forested systems. Paired-watershed studies are often used to evaluate effects of timber harvest on watershed processes.

USING HISTORICAL BIOLOGICAL DATA TO EVALUATE STATUS AND TRENDS IN THE BIG DARBY CREEK WATERSHED (OHIO, USA)

EPA Science Inventory

Assessment of watershed ecological status and trends is challenging for managers who lack randomly or consistently sampled data, or monitoring programs developed from a watershed perspective. This study investigated analytical approaches for assessment of status and trends using ...

LINKING LAND COVER AND WATER QUALITY IN NEW YORK CITY'S WATER SUPPLY WATERSHEDS

EPA Science Inventory

The Catskill/Delaware reservoirs supply 90% of New York City's drinking water. The City has implemented as series of watershed protection measures, including land acquisition, aimed at preserving water quality in the Catskill/Delaware watersheds. The objective of this study was...

APEX Model Simulation for Row Crop Watersheds with Agroforestry and Grass Buffers

USDA-ARS?s Scientific Manuscript database

Watershed model simulation has become an important tool in studying ways and means to reduce transport of agricultural pollutants. Conducting field experiments to assess buffer influences on water quality are constrained by the large-scale nature of watersheds, high experimental costs, private owner...

The Alsea Watershed Study: a comparison with other multi-year investigations in the Pacific Northwest

Treesearch

Peter A. Bisson; Stanley V. Gregory; Thomas E. Nickelson; James D. Hall

2008-01-01

The Alsea Watershed Study (AWS) was the first long-term fisheries research project to address the effects of forestry operations on salmonid populations in the Pacific Northwest using a watershed approach. To this day it remains one of a very limited number of investigations that have provided long-term information on salmon and trout responses to forestry operations....

Effects of watershed experiments on water chemistry at the Marcell Experimental Forest. Chapter 14.

Treesearch

Stephen D. Sebestyen; Elon S. Verry

2011-01-01

The Marcell Experimental Forest (MEF) was established during the 1960s to study the hydrology and ecology of lowland watersheds where upland mineral soils drain to central peatlands (Boelter and Verry 1977). The effects of seven large-scale manipulations on water chemistry have been studied on the MEF watersheds and the data now span up to four decades. In this chapter...

Effects of forest cover and environmental variables on snow accumulation and melt

Treesearch

Mariana Dobre; William J. Elliot; Joan Q. Wu; Timothy E. Link; Ina S. Miller

2011-01-01

The goal of this study was to assess the effects of topography and forest cover resulting from different treatments on snow accumulation and melt in small watersheds in the western United States. A paired-watershed study was implemented at the Priest River Experimental Forest, Idaho, where 10 small watersheds with an average area of 4.5 ha were treated by: 1) control (...

Analysis of the efficacy and cost-effectiveness of best management practices for controlling sediment yield: A case study of the Joumine watershed, Tunisia.

PubMed

Mtibaa, Slim; Hotta, Norifumi; Irie, Mitsuteru

2018-03-01

Soil erosion can be reduced through the strategic selection and placement of best management practices (BMPs) in critical source areas (CSAs). In the present study, the Soil Water Assessment Tool (SWAT) model was used to identify CSAs and investigate the effectiveness of different BMPs in reducing sediment yield in the Joumine watershed, an agricultural river catchment located in northern Tunisia. A cost-benefit analysis (CBA) was used to evaluate the cost-effectiveness of different BMP scenarios. The objective of the present study was to determine the most cost-effective management scenario for controlling sediment yield. The model performance for the simulation of streamflow and sediment yield at the outlet of the Joumine watershed was good and satisfactory, respectively. The model indicated that most of the sediment was originated from the cultivated upland area. About 34% of the catchment area consisted of CSAs that were affected by high to very high soil erosion risk (sediment yield >10t/ha/year). Contour ridges were found to be the most effective individual BMP in terms of sediment yield reduction. At the watershed level, implementing contour ridges in the CSAs reduced sediment yield by 59%. Combinations of BMP scenarios were more cost-effective than the contour ridges alone. Combining buffer strips (5-m width) with other BMPs depending on land slope (> 20% slope: conversion to olive orchards; 10-20% slope: contour ridges; 5-10% slope: grass strip cropping) was the most effective approach in terms of sediment yield reduction and economic benefits. This approach reduced sediment yield by 61.84% with a benefit/cost ratio of 1.61. Compared with the cost of dredging, BMPs were more cost-effective for reducing sediment loads to the Joumine reservoir, located downstream of the catchment. Our findings may contribute to ensure the sustainability of future conservation programs in Tunisian regions. Copyright © 2017 Elsevier B.V. All rights reserved.

Sensitivity analysis of ecosystem service valuation in a Mediterranean watershed.

PubMed

Sánchez-Canales, María; López Benito, Alfredo; Passuello, Ana; Terrado, Marta; Ziv, Guy; Acuña, Vicenç; Schuhmacher, Marta; Elorza, F Javier

2012-12-01

The services of natural ecosystems are clearly very important to our societies. In the last years, efforts to conserve and value ecosystem services have been fomented. By way of illustration, the Natural Capital Project integrates ecosystem services into everyday decision making around the world. This project has developed InVEST (a system for Integrated Valuation of Ecosystem Services and Tradeoffs). The InVEST model is a spatially integrated modelling tool that allows us to predict changes in ecosystem services, biodiversity conservation and commodity production levels. Here, InVEST model is applied to a stakeholder-defined scenario of land-use/land-cover change in a Mediterranean region basin (the Llobregat basin, Catalonia, Spain). Of all InVEST modules and sub-modules, only the behaviour of the water provisioning one is investigated in this article. The main novel aspect of this work is the sensitivity analysis (SA) carried out to the InVEST model in order to determine the variability of the model response when the values of three of its main coefficients: Z (seasonal precipitation distribution), prec (annual precipitation) and eto (annual evapotranspiration), change. The SA technique used here is a One-At-a-Time (OAT) screening method known as Morris method, applied over each one of the one hundred and fifty four sub-watersheds in which the Llobregat River basin is divided. As a result, this method provides three sensitivity indices for each one of the sub-watersheds under consideration, which are mapped to study how they are spatially distributed. From their analysis, the study shows that, in the case under consideration and between the limits considered for each factor, the effect of the Z coefficient on the model response is negligible, while the other two need to be accurately determined in order to obtain precise output variables. The results of this study will be applicable to the others watersheds assessed in the Consolider Scarce Project. Copyright © 2012 Elsevier B.V. All rights reserved.

Watershed Management and Public Health: An Exploration of the Intersection of Two Fields as Reported in the Literature from 2000 to 2010

NASA Astrophysics Data System (ADS)

Bunch, Martin J.; Parkes, Margot; Zubrycki, Karla; Venema, Henry; Hallstrom, Lars; Neudorffer, Cynthia; Berbés-Blázquez, Marta; Morrison, Karen

2014-08-01

Watersheds are settings for health and well-being that have a great deal to offer the public health community due to the correspondence between the spatial form of the watershed unit and the importance to health and well-being of water. However, managing watersheds for human health and well-being requires the ability to move beyond typical reductionist approaches toward more holistic methods. Health and well-being are emergent properties of inter-related social and biophysical processes. This paper characterizes points of connection and integration between watershed management and public health and tests a new conceptual model, the Watershed Governance Prism, to determine the prevalence in peer-reviewed literature of different perspectives relating to watersheds and public health. We conducted an initial search of academic databases for papers that addressed the interface between watershed management (or governance) and public health themes. We then generated a sample of these papers and undertook a collaborative analysis informed by the Watershed Governance Prism. Our analysis found that although these manuscripts dealt with a range of biophysical and social determinants of health, there was a tendency for social factors and health outcomes to be framed as context only for these studies, rather than form the core of the relationships being investigated. At least one cluster of papers emerged from this analysis that represented a cohesive perspective on watershed governance and health; "Perspective B" on the Watershed Governance Prism, "water governance for ecosystems and well-being," was dominant. Overall, the integration of watershed management/governance and public health is in its infancy.

Watershed management and public health: an exploration of the intersection of two fields as reported in the literature from 2000 to 2010.

PubMed

Bunch, Martin J; Parkes, Margot; Zubrycki, Karla; Venema, Henry; Hallstrom, Lars; Neudorffer, Cynthia; Berbés-Blázquez, Marta; Morrison, Karen

2014-08-01

Watersheds are settings for health and well-being that have a great deal to offer the public health community due to the correspondence between the spatial form of the watershed unit and the importance to health and well-being of water. However, managing watersheds for human health and well-being requires the ability to move beyond typical reductionist approaches toward more holistic methods. Health and well-being are emergent properties of inter-related social and biophysical processes. This paper characterizes points of connection and integration between watershed management and public health and tests a new conceptual model, the Watershed Governance Prism, to determine the prevalence in peer-reviewed literature of different perspectives relating to watersheds and public health. We conducted an initial search of academic databases for papers that addressed the interface between watershed management (or governance) and public health themes. We then generated a sample of these papers and undertook a collaborative analysis informed by the Watershed Governance Prism. Our analysis found that although these manuscripts dealt with a range of biophysical and social determinants of health, there was a tendency for social factors and health outcomes to be framed as context only for these studies, rather than form the core of the relationships being investigated. At least one cluster of papers emerged from this analysis that represented a cohesive perspective on watershed governance and health; "Perspective B" on the Watershed Governance Prism, "water governance for ecosystems and well-being," was dominant. Overall, the integration of watershed management/governance and public health is in its infancy.

Characterizing a Century of Climate and Hydrological Variability of a Mediterranean and Mountainous Watersheds: the Durance River Case-Study

NASA Astrophysics Data System (ADS)

Mathevet, T.; Kuentz, A.; Gailhard, J.; Andreassian, V.

2013-12-01

Improving the understanding of mountain watersheds hydrological variability is a great scientific issue, for both researchers and water resources managers, such as Electricite de France (Energy and Hydropower Company). The past and current context of climate variability enhances the interest on this topic, since multi-purposes water resources management is highly sensitive to this variability. The Durance River watershed (14000 km2), situated in the French Alps, is a good example of the complexity of this issue. It is characterized by a variety of hydrological processes (from snowy to Mediterranean regimes) and a wide range of anthropogenic influences (hydropower, irrigation, flood control, tourism and water supply), mixing potential causes of changes in its hydrological regimes. As water related stakes are numerous in this watershed, improving knowledge on the hydrological variability of the Durance River appears to be essential. In this presentation, we would like to focus on a methodology we developed to build long-term historical hydrometeorological time-series, based on atmospheric reanalysis (20CR : 20th Century Reanalysis) and historical local observations. This methodology allowed us to generate precipitation, air temperature and streamflow time-series at a daily time-step for a sample of 22 watersheds, for the 1883-2010 period. These long-term streamflow reconstructions have been validated thanks to historical searches that allowed to bring to light ten long historical series of daily streamflows, beginning on the early 20th century. Reconstructions appear to have rather good statistical properties, with good correlation (greater than 0.8) and limited mean and variance bias (less than 5%). Then, these long-term hydrometeorological time-series allowed us to characterize the past variability in terms of available water resources, droughts or hydrological regime. These analyses help water resources managers to better know the range of hydrological variabilities, which are usually greatly underestimated with classical available time-series (less than 50 years).

Disentangling the Long-term Effects of Climate Change and Forest Structure and Species Composition on Streamflow Across the Eastern US

NASA Astrophysics Data System (ADS)

Caldwell, P.; Elliott, K.; Hartsell, A.; Miniat, C.

2016-12-01

Climate change and disturbances are threatening the ability of forested watersheds to provide the clean, reliable, and abundant fresh water necessary to support aquatic ecosystems and a growing human population. Forested watersheds in the eastern US have undergone significant change over the 20th century due to natural and introduced disturbances and a legacy of land use. We hypothesize that changes in forest age and species composition (i.e., forest change) associated with these disturbances may have altered forest water use and thus streamflow (Q) due to inherent differences in transpiration among species and forest ages. To test this hypothesis, we quantified changes in Q from 1960 to 2012 in 202 US Geological Survey forested reference watersheds across the eastern US, and separated the effect of changes in climate from forest change using Auto-Regressive Integrated Moving Average (ARIMA) time series modeling. We linked changes in Q to forest disturbance, forest ages and species composition using the Landsat-based North American Forest Dynamics dataset and plot-level USDA Forest Service Forest Inventory and Analysis (FIA) data. We found that 172 of the 202 sites (85%) exhibited changes in Q not accounted for by climate that we attributed to forest change and/or land use change. Among these, 76 (44%) had declining Q due to forest change (mostly in the southeastern US) while 96 (56%) had increasing Q (mostly in the mid-Atlantic and northeastern US). Across the 172 sites with forest-related changes in Q, 34% had at least 10% of the watershed area disturbed at least once from 1986-2010. In a case study of three watersheds, FIA data indicated that changes in forest structure and species composition explained observed changes in Q beyond climate effects. Our results suggest that forest-related changes in Q may have significant implications for water supply in the region and may inform forest management strategies to mitigate climate change impacts on water resources.

Consequences of land use cover change and precipitation regimes on water quality in a tropical landscape: the case of São Paulo, Brazil

NASA Astrophysics Data System (ADS)

Ribeiro Piffer, P.; Reverberi Tambosi, L.; Uriarte, M.

2017-12-01

One of the most pressing challenges faced by modern societies is ensuring a sufficient supply of water considering the ever-growing conflict between environmental conservation and expansion of agricultural and urban frontiers worldwide. Land use cover change have marked effects on natural landscapes, putting key watershed ecosystem services in jeopardy. We investigated the consequences of land use cover change and precipitation regimes on water quality in the state of São Paulo, Brazil, a landscape that underwent major changes in past century. Water quality data collected bi-monthly between 2000 and 2014 from 229 water monitoring stations was analyzed together with 2011 land use cover maps. We focused on six water quality metrics (dissolved oxygen, total nitrogen, total phosphorus, turbidity, total dissolved solids and fecal coliforms) and used generalized linear mixed models to analyze the data. Models were built at two scales, the entire watershed and a 60 meters riparian buffer along the river network. Models accounted for 46-67% of the variance in water quality metrics and, apart from dissolved oxygen, which reflected land cover composition in riparian buffers, all metrics responded to land use at the watershed scale. Highly urbanized areas had low dissolved oxygen and high fecal coliforms, dissolved solids, phosphorus and nitrogen levels in streams. Pasture was associated with increases in turbidity, while sugarcane plantations significantly increased nitrogen concentrations. Watersheds with high forest cover had greater dissolved oxygen and lower turbidity. Silviculture plantations had little impact on water quality. Precipitation decreased dissolved oxygen and was associated with higher levels of turbidity, fecal coliforms and phosphorus. Results indicate that conversion of forest cover to other land uses had negative impacts on water quality in the study area, highlighting the need for landscape restoration to improve watersheds ecosystem services.

Tracking geomorphic signatures of watershed suburbanization with multi-temporal LiDAR

USGS Publications Warehouse

Jones, Daniel K.; Baker, Matthew E.; Miller, Andrew J.; Jarnagin, S. Taylor; Hogan, Dianna M.

2014-01-01

Urban development practices redistribute surface materials through filling, grading, and terracing, causing drastic changes to the geomorphic organization of the landscape. Many studies document the hydrologic, biologic, or geomorphic consequences of urbanization using space-for-time comparisons of disparate urban and rural landscapes. However, no previous studies have documented geomorphic changes from development using multiple dates of high-resolution topographic data at the watershed scale. This study utilized a time series of five sequential light detection and ranging (LiDAR) derived digital elevation models (DEMs) to track watershed geomorphic changes within two watersheds throughout development (2002–2008) and across multiple spatial scales (0.01–1 km2). Development-induced changes were compared against an undeveloped forested watershed during the same time period. Changes in elevations, slopes, hypsometry, and surface flow pathways were tracked throughout the development process to assess watershed geomorphic alterations. Results suggest that development produced an increase in sharp topographic breaks between relatively flat surfaces and steep slopes, replacing smoothly varying hillslopes and leading to greater variation in slopes. Examinations of flowpath distributions highlight systematic modifications that favor rapid convergence in unchanneled upland areas. Evidence of channel additions in the form of engineered surface conduits is apparent in comparisons of pre- and post-development stream maps. These results suggest that topographic modification, in addition to impervious surfaces, contributes to altered hydrologic dynamics observed in urban systems. This work highlights important considerations for the use of repeat LiDAR flights in analyzing watershed change through time. Novel methods introduced here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during development and help guide future research directions for development-based watershed studies.