EVALUATION OF LAND USE/LAND COVER DATASETS FOR URBAN WATERSHED MODELING

International Nuclear Information System (INIS)

S.J. BURIAN; M.J. BROWN; T.N. MCPHERSON

2001-01-01

Land use/land cover (LULC) data are a vital component for nonpoint source pollution modeling. Most watershed hydrology and pollutant loading models use, in some capacity, LULC information to generate runoff and pollutant loading estimates. Simple equation methods predict runoff and pollutant loads using runoff coefficients or pollutant export coefficients that are often correlated to LULC type. Complex models use input variables and parameters to represent watershed characteristics and pollutant buildup and washoff rates as a function of LULC type. Whether using simple or complex models an accurate LULC dataset with an appropriate spatial resolution and level of detail is paramount for reliable predictions. The study presented in this paper compared and evaluated several LULC dataset sources for application in urban environmental modeling. The commonly used USGS LULC datasets have coarser spatial resolution and lower levels of classification than other LULC datasets. In addition, the USGS datasets do not accurately represent the land use in areas that have undergone significant land use change during the past two decades. We performed a watershed modeling analysis of three urban catchments in Los Angeles, California, USA to investigate the relative difference in average annual runoff volumes and total suspended solids (TSS) loads when using the USGS LULC dataset versus using a more detailed and current LULC dataset. When the two LULC datasets were aggregated to the same land use categories, the relative differences in predicted average annual runoff volumes and TSS loads from the three catchments were 8 to 14% and 13 to 40%, respectively. The relative differences did not have a predictable relationship with catchment size

Hydrological Modeling of the Jiaoyi Watershed (China) Using HSPF Model

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Yan, Chang-An; Zhang, Wanchang; Zhang, Zhijie

2014-01-01

A watershed hydrological model, hydrological simulation program-Fortran (HSPF), was applied to simulate the spatial and temporal variation of hydrological processes in the Jiaoyi watershed of Huaihe River Basin, the heaviest shortage of water resources and polluted area in China. The model was calibrated using the years 2001–2004 and validated with data from 2005 to 2006. Calibration and validation results showed that the model generally simulated mean monthly and daily runoff precisely due to the close matching hydrographs between simulated and observed runoff, as well as the excellent evaluation indicators such as Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R 2), and the relative error (RE). The similar simulation results between calibration and validation period showed that all the calibrated parameters had a certain representation in Jiaoyi watershed. Additionally, the simulation in rainy months was more accurate than the drought months. Another result in this paper was that HSPF was also capable of estimating the water balance components reasonably and realistically in space through the whole watershed. The calibrated model can be used to explore the effects of climate change scenarios and various watershed management practices on the water resources and water environment in the basin. PMID:25013863

GIBSI: an integrated modelling system for watershed management – sample applications and current developments

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A. N. Rousseau

2007-11-01

Full Text Available Hydrological and pollutant fate models have long been developed for research purposes. Today, they find an application in integrated watershed management, as decision support systems (DSS. GIBSI is such a DSS designed to assist stakeholders in watershed management. It includes a watershed database coupled to a GIS and accessible through a user-friendly interface, as well as modelling tools that simulate, on a daily time step, hydrological processes such as evapotranspiration, runoff, soil erosion, agricultural pollutant transport and surface water quality. Therefore, GIBSI can be used to assess a priori the effect of management scenarios (reservoirs, land use, waste water effluents, diffuse sources of pollution that is agricultural pollution on surface hydrology and water quality. For illustration purposes, this paper presents several management-oriented applications using GIBSI on the 6680 km2 Chaudière River watershed, located near Quebec City (Canada. They include impact assessments of: (i municipal clean water program; (ii agricultural nutrient management scenarios; (iii past and future land use changes, as well as (iv determination of achievable performance standards of pesticides management practices. Current and future developments of GIBSI are also presented as these will extend current uses of this tool and make it useable and applicable by stakeholders on other watersheds. Finally, the conclusion emphasizes some of the challenges that remain for a better use of DSS in integrated watershed management.

Soil Erodibility for Water Pollution Management of Melaka Watershed in Peninsular Malaysia

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Md. Ibrahim Adham

2015-07-01

Full Text Available The relationships between surface runoffand soil erodibility are significant in water pollution and watershed management practices. Land use pattern, soil series and slope percentage are also major factors to develop the relationships. Daily rainfall data were collected and analyzed for variations in precipitation for calculating the surface runoff of these watersheds and surface runoff map was produced by GIS tools. Tew equation was utilized to predict soil erodibility of watershed soils.Results indicated that the weighted curve number varies from 82 to 85 and monthly runoff 23% to 30% among the five watersheds. Soil erodibility varies from 0.038 to 0.06 ton/ha (MJ.mm/ha/h. Linau-Telok-Local Alluvium, Malacca-Munchong, Munchong-Malacca-Serdang and Malacca-Munchong-Tavy are the dominant soil series of this region having the average soil erodibility of about 0.042 ton/ha (MJ.mm/ha/h. The main focus of this study is to provide the information of soil erodibility to reduce the water pollution of a watershed.

Rainfall Deduction Method for Estimating Non-Point Source Pollution Load for Watershed

OpenAIRE

Cai, Ming; Li, Huai-en; KAWAKAMI, Yoji

2004-01-01

The water pollution can be divided into point source pollution (PSP) and non-point source pollution (NSP). Since the point source pollution has been controlled, the non-point source pollution is becoming the main pollution source. The prediction of NSP load is being increasingly important in water pollution controlling and planning in watershed. Considering the monitoring data shortage of NPS in China, a practical estimation method of non-point source pollution load --- rainfall deduction met...

Nitrogen component in nonpoint source pollution models

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Pollutants entering a water body can be very destructive to the health of that system. Best Management Practices (BMPs) and/or conservation practices are used to reduce these pollutants, but understanding the most effective practices is very difficult. Watershed models are an effective tool to aid...

Spatiotemporal patterns and source attribution of nitrogen pollution in a typical headwater agricultural watershed in Southeastern China.

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Chen, Wenjun; He, Bin; Nover, Daniel; Duan, Weili; Luo, Chuan; Zhao, Kaiyan; Chen, Wen

2018-01-01

Excessive nitrogen (N) discharge from agriculture causes widespread problems in aquatic ecosystems. Knowledge of spatiotemporal patterns and source attribution of N pollution is critical for nutrient management programs but is poorly studied in headwaters with various small water bodies and mini-point pollution sources. Taking a typical small watershed in the low mountains of Southeastern China as an example, N pollution and source attribution were studied for a multipond system around a village using the Hydrological Simulation Program-Fortran (HSPF) model. The results exhibited distinctive spatio-seasonal variations with an overall seriousness rank for the three indicators: total nitrogen (TN) > nitrate/nitrite nitrogen (NO x - -N) > ammonia nitrogen (NH 3 -N), according to the Chinese Surface Water Quality Standard. TN pollution was severe for the entire watershed, while NO x - -N pollution was significant for ponds and ditches far from the village, and the NH 3 -N concentrations were acceptable except for the ponds near the village in summer. Although food and cash crop production accounted for the largest source of N loads, we discovered that mini-point pollution sources, including animal feeding operations, rural residential sewage, and waste, together contributed as high as 47% of the TN and NH 3 -N loads in ponds and ditches. So, apart from eco-fertilizer programs and concentrated animal feeding operations, the importance of environmental awareness building for resource management is highlighted for small farmers in headwater agricultural watersheds. As a first attempt to incorporate multipond systems into the process-based modeling of nonpoint source (NPS) pollution, this work can inform other hydro-environmental studies on scattered and small water bodies. The results are also useful to water quality improvement for entire river basins.

Assessment of Water Quality and Identification of Polluted Risky Regions Based on Field Observations & GIS in the Honghe River Watershed, China

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Yan, Chang-An; Zhang, Wanchang; Zhang, Zhijie; Liu, Yuanmin; Deng, Cai; Nie, Ning

2015-01-01

Water quality assessment at the watershed scale requires not only an investigation of water pollution and the recognition of main pollution factors, but also the identification of polluted risky regions resulted in polluted surrounding river sections. To realize this objective, we collected water samplings from 67 sampling sites in the Honghe River watershed of China with Grid GIS method to analyze six parameters including dissolved oxygen (DO), ammonia nitrogen (NH3-N), nitrate nitrogen (NO3-N), nitrite nitrogen (NO2-N), total nitrogen (TN) and total phosphorus (TP). Single factor pollution index and comprehensive pollution index were adopted to explore main water pollutants and evaluate water quality pollution level. Based on two evaluate methods, Geo-statistical analysis and Geographical Information System (GIS) were used to visualize the spatial pollution characteristics and identifying potential polluted risky regions. The results indicated that the general water quality in the watershed has been exposed to various pollutants, in which TP, NO2-N and TN were the main pollutants and seriously exceeded the standard of Category III. The zones of TP, TN, DO, NO2-N and NH3-N pollution covered 99.07%, 62.22%, 59.72%, 37.34% and 13.82% of the watershed respectively, and they were from medium to serious polluted. 83.27% of the watershed in total was polluted by comprehensive pollutants. These conclusions may provide useful and effective information for watershed water pollution control and management. PMID:25768942

Assessing groundwater pollution hazard changes under different socio-economic and environmental scenarios in an agricultural watershed

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Lima, M. Lourdes, E-mail: mlima@mdp.edu.ar [Instituto de Geología de Costas y del Cuaternario, FCEyN, Universidad Nacional de Mar del Plata, Funes 3350, Nivel 1, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Romanelli, Asunción, E-mail: aromanel@mdp.edu.ar [Instituto de Geología de Costas y del Cuaternario, FCEyN, Universidad Nacional de Mar del Plata, Funes 3350, Nivel 1, 7600 Mar del Plata (Argentina); Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Massone, Héctor E., E-mail: hmassone@mdp.edu.ar [Instituto de Geología de Costas y del Cuaternario, FCEyN, Universidad Nacional de Mar del Plata, Funes 3350, Nivel 1, 7600 Mar del Plata (Argentina)

2015-10-15

This paper proposes a modeling approach for assessing changes in groundwater pollution hazard under two different socio-economic and environmental scenarios: The first one considers an exponential growth of agriculture land-use (Relegated Sustainability), while the other deals with regional economic growth, taking into account, the restrictions put on natural resources use (Sustainability Reforms). The recent (2011) and forecasted (2030) groundwater pollution hazard is evaluated based on hydrogeological parameters and, the impact of land-use changes in the groundwater system, coupling together a land-use change model (Dyna-CLUE) with a groundwater flow model (MODFLOW), as inputs to a decision system support (EMDS). The Dulce Stream Watershed (Pampa Plain, Argentina) was chosen to test the usefulness and utility of this proposed method. It includes a high level of agricultural activities, significant local extraction of groundwater resources for drinking water and irrigation and extensive available data regarding aquifer features. The Relegated Sustainability Scenario showed a negative change in the aquifer system, increasing (+ 20%; high–very high classes) the contribution to groundwater pollution hazard throughout the watershed. On the other hand, the Sustainability Reforms Scenario displayed more balanced land-use changes with a trend towards sustainability, therefore proposing a more acceptable change in the aquifer system for 2030 with a possible 2% increase (high–very high classes) in groundwater pollution hazard. Results in the recent scenario (2011) showed that 54% of Dulce Stream Watershed still shows a moderate to a very low contribution to groundwater pollution hazard (mainly in the lower area). Therefore, from the point of view of natural resource management, this is a positive aspect, offering possibilities for intervention in order to prevent deterioration and protect this aquifer system. However, since it is quite possible that this aquifer status

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

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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

Temporal-spatial distribution of non-point source pollution in a drinking water source reservoir watershed based on SWAT

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M. Wang

2015-05-01

Full Text Available The conservation of drinking water source reservoirs has a close relationship between regional economic development and people’s livelihood. Research on the non-point pollution characteristics in its watershed is crucial for reservoir security. Tang Pu Reservoir watershed was selected as the study area. The non-point pollution model of Tang Pu Reservoir was established based on the SWAT (Soil and Water Assessment Tool model. The model was adjusted to analyse the temporal-spatial distribution patterns of total nitrogen (TN and total phosphorus (TP. The results showed that the loss of TN and TP in the reservoir watershed were related to precipitation in flood season. And the annual changes showed an "M" shape. It was found that the contribution of loss of TN and TP accounted for 84.5% and 85.3% in high flow years, and for 70.3% and 69.7% in low flow years, respectively. The contributions in normal flow years were 62.9% and 63.3%, respectively. The TN and TP mainly arise from Wangtan town, Gulai town, and Wangyuan town, etc. In addition, it was found that the source of TN and TP showed consistency in space.

Integrative Application of Life Cycle Assessment and Risk Assessment to Environmental Impacts of Anthropogenic Pollutants at a Watershed Scale.

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Lin, Xiaodan; Yu, Shen; Ma, Hwongwen

2018-01-01

Intense human activities have led to increasing deterioration of the watershed environment via pollutant discharge, which threatens human health and ecosystem function. To meet a need of comprehensive environmental impact/risk assessment for sustainable watershed development, a biogeochemical process-based life cycle assessment and risk assessment (RA) integration for pollutants aided by geographic information system is proposed in this study. The integration is to frame a conceptual protocol of "watershed life cycle assessment (WLCA) for pollutants". The proposed WLCA protocol consists of (1) geographic and environmental characterization mapping; (2) life cycle inventory analysis; (3) integration of life-cycle impact assessment (LCIA) with RA via characterization factor of pollutant of interest; and (4) result analysis and interpretation. The WLCA protocol can visualize results of LCIA and RA spatially for the pollutants of interest, which might be useful for decision or policy makers for mitigating impacts of watershed development.

Retrospective Review of Watershed Characteristics and a Framework for Future Research in the Sarasota Bay Watershed, Florida

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Kish, George R.; Harrison, Arnell S.; Alderson, Mark

2008-01-01

The U.S. Geological Survey, in cooperation with the Sarasota Bay Estuary Program conducted a retrospective review of characteristics of the Sarasota Bay watershed in west-central Florida. This report describes watershed characteristics, surface- and ground-water processes, and the environmental setting of the Sarasota Bay watershed. Population growth during the last 50 years is transforming the Sarasota Bay watershed from rural and agriculture to urban and suburban. The transition has resulted in land-use changes that influence surface- and ground-water processes in the watershed. Increased impervious cover decreases recharge to ground water and increases overland runoff and the pollutants carried in the runoff. Soil compaction resulting from agriculture, construction, and recreation activities also decreases recharge to ground water. Conventional approaches to stormwater runoff have involved conveyances and large storage areas. Low-impact development approaches, designed to provide recharge near the precipitation point-of-contact, are being used increasingly in the watershed. Simple pollutant loading models applied to the Sarasota Bay watershed have focused on large-scale processes and pollutant loads determined from empirical values and mean event concentrations. Complex watershed models and more intensive data-collection programs can provide the level of information needed to quantify (1) the effects of lot-scale land practices on runoff, storage, and ground-water recharge, (2) dry and wet season flux of nutrients through atmospheric deposition, (3) changes in partitioning of water and contaminants as urbanization alters predevelopment rainfall-runoff relations, and (4) linkages between watershed models and lot-scale models to evaluate the effect of small-scale changes over the entire Sarasota Bay watershed. As urbanization in the Sarasota Bay watershed continues, focused research on water-resources issues can provide information needed by water

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

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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.

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

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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.

Modeling the impacts of wildfire on runoff and pollutant transport from coastal watersheds to the nearshore environment.

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Morrison, Katherine D; Kolden, Crystal A

2015-03-15

Wildfire is a common disturbance that can significantly alter vegetation in watersheds and affect the rate of sediment and nutrient transport to adjacent nearshore oceanic environments. Changes in runoff resulting from heterogeneous wildfire effects are not well-understood due to both limitations in the field measurement of runoff and temporally-limited spatial data available to parameterize runoff models. We apply replicable, scalable methods for modeling wildfire impacts on sediment and nonpoint source pollutant export into the nearshore environment, and assess relationships between wildfire severity and runoff. Nonpoint source pollutants were modeled using a GIS-based empirical deterministic model parameterized with multi-year land cover data to quantify fire-induced increases in transport to the nearshore environment. Results indicate post-fire concentration increases in phosphorus by 161 percent, sediments by 350 percent and total suspended solids (TSS) by 53 percent above pre-fire years. Higher wildfire severity was associated with the greater increase in exports of pollutants and sediment to the nearshore environment, primarily resulting from the conversion of forest and shrubland to grassland. This suggests that increasing wildfire severity with climate change will increase potential negative impacts to adjacent marine ecosystems. The approach used is replicable and can be utilized to assess the effects of other types of land cover change at landscape scales. It also provides a planning and prioritization framework for management activities associated with wildfire, including suppression, thinning, and post-fire rehabilitation, allowing for quantification of potential negative impacts to the nearshore environment in coastal basins. Copyright © 2014 Elsevier Ltd. All rights reserved.

The impact of Land use Change on Water Pollution Index of Kali Madiun Sub-watershed

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Pranatasari Dyah Susanti

2017-07-01

Full Text Available Land use change is one of the effects of population growth and increased human activities. Land use change that overlooked the rule of ecosystem sustainability has a propensity to adversely affect the environment, including the decline of water quality. Kali Madiun is a sub-watershed of Bengawan Solo Watershed that allegedly endured the impacts of land use change. This study aimed to investigate the impacts of land use change on the water quality index of Kali Madiun Sub-watershed. Land use change analysis was done by overlay analysis of spatial data including the maps of land use in 2010 and 2015. Samples were the surface water in the upper, middle and lower part of Kali Madiun Sub-Watershed. Water quality analysis was carried out by comparing the results of water quality parameter assessment based on Government Regulation No. 82 of 2001, while water quality index was figured out by an assessment based on the Decree of the Minister of Environment No. 115 of 2003. The results indicated that during the five years observation, there were land use changes in the upper, middle and lower part of Kali Madiun Sub-watershed. Several parameters increased in 2010 to 2015, namely: TDS, BOD, COD, nitrate, detergents, oils and greases. Pollution index shifted from slightly polluted in 2010 into moderately polluted in 2015. We propose a strategy to solve these problems by the involvement of stakeholders and the participation of local community in managing both domestic and industrial wastes. Also, it should be supported by palpable regulations related to land conversion. Furthermore, it is expected that the effort will reduce the potential of pollution and improve the water quality.

Quantitative identification of nitrate pollution sources and uncertainty analysis based on dual isotope approach in an agricultural watershed.

Science.gov (United States)

Ji, Xiaoliang; Xie, Runting; Hao, Yun; Lu, Jun

2017-10-01

Quantitative identification of nitrate (NO 3 - -N) sources is critical to the control of nonpoint source nitrogen pollution in an agricultural watershed. Combined with water quality monitoring, we adopted the environmental isotope (δD-H 2 O, δ 18 O-H 2 O, δ 15 N-NO 3 - , and δ 18 O-NO 3 - ) analysis and the Markov Chain Monte Carlo (MCMC) mixing model to determine the proportions of riverine NO 3 - -N inputs from four potential NO 3 - -N sources, namely, atmospheric deposition (AD), chemical nitrogen fertilizer (NF), soil nitrogen (SN), and manure and sewage (M&S), in the ChangLe River watershed of eastern China. Results showed that NO 3 - -N was the main form of nitrogen in this watershed, accounting for approximately 74% of the total nitrogen concentration. A strong hydraulic interaction existed between the surface and groundwater for NO 3 - -N pollution. The variations of the isotopic composition in NO 3 - -N suggested that microbial nitrification was the dominant nitrogen transformation process in surface water, whereas significant denitrification was observed in groundwater. MCMC mixing model outputs revealed that M&S was the predominant contributor to riverine NO 3 - -N pollution (contributing 41.8% on average), followed by SN (34.0%), NF (21.9%), and AD (2.3%) sources. Finally, we constructed an uncertainty index, UI 90 , to quantitatively characterize the uncertainties inherent in NO 3 - -N source apportionment and discussed the reasons behind the uncertainties. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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.

Watershed model calibration framework developed using an influence coefficient algorithm and a genetic algorithm and analysis of pollutant discharge characteristics and load reduction in a TMDL planning area.

Science.gov (United States)

Cho, Jae Heon; Lee, Jong Ho

2015-11-01

Manual calibration is common in rainfall-runoff model applications. However, rainfall-runoff models include several complicated parameters; thus, significant time and effort are required to manually calibrate the parameters individually and repeatedly. Automatic calibration has relative merit regarding time efficiency and objectivity but shortcomings regarding understanding indigenous processes in the basin. In this study, a watershed model calibration framework was developed using an influence coefficient algorithm and genetic algorithm (WMCIG) to automatically calibrate the distributed models. The optimization problem used to minimize the sum of squares of the normalized residuals of the observed and predicted values was solved using a genetic algorithm (GA). The final model parameters were determined from the iteration with the smallest sum of squares of the normalized residuals of all iterations. The WMCIG was applied to a Gomakwoncheon watershed located in an area that presents a total maximum daily load (TMDL) in Korea. The proportion of urbanized area in this watershed is low, and the diffuse pollution loads of nutrients such as phosphorus are greater than the point-source pollution loads because of the concentration of rainfall that occurs during the summer. The pollution discharges from the watershed were estimated for each land-use type, and the seasonal variations of the pollution loads were analyzed. Consecutive flow measurement gauges have not been installed in this area, and it is difficult to survey the flow and water quality in this area during the frequent heavy rainfall that occurs during the wet season. The Hydrological Simulation Program-Fortran (HSPF) model was used to calculate the runoff flow and water quality in this basin. Using the water quality results, a load duration curve was constructed for the basin, the exceedance frequency of the water quality standard was calculated for each hydrologic condition class, and the percent reduction

Coupling a continuous watershed-scale microbial fate and transport model with a stochastic dose-response model to estimate risk of illness in an urban watershed

Energy Technology Data Exchange (ETDEWEB)

Liao, Hehuan, E-mail: hehuan86@vt.edu [Department of Biological Systems Engineering, Virginia Tech, 155 Ag Quad Lane, Blacksburg, VA 24061 (United States); Krometis, Leigh-Anne H. [Department of Biological Systems Engineering, Virginia Tech, 155 Ag Quad Lane, Blacksburg, VA 24061 (United States); Kline, Karen [Department of Biological Systems Engineering, Virginia Tech, 155 Ag Quad Lane, Blacksburg, VA 24061 (United States); Center for Watershed Studies, Virginia Tech, 155 Ag Quad Lane, Blacksburg, VA 24061 (United States)

2016-05-01

Within the United States, elevated levels of fecal indicator bacteria (FIB) remain the leading cause of surface water-quality impairments requiring formal remediation plans under the federal Clean Water Act's Total Maximum Daily Load (TMDL) program. The sufficiency of compliance with numerical FIB criteria as the targeted endpoint of TMDL remediation plans may be questionable given poor correlations between FIB and pathogenic microorganisms and varying degrees of risk associated with exposure to different fecal pollution sources (e.g. human vs animal). The present study linked a watershed-scale FIB fate and transport model with a dose-response model to continuously predict human health risks via quantitative microbial risk assessment (QMRA), for comparison to regulatory benchmarks. This process permitted comparison of risks associated with different fecal pollution sources in an impaired urban watershed in order to identify remediation priorities. Results indicate that total human illness risks were consistently higher than the regulatory benchmark of 36 illnesses/1000 people for the study watershed, even when the predicted FIB levels were in compliance with the Escherichia coli geometric mean standard of 126 CFU/100 mL. Sanitary sewer overflows were associated with the greatest risk of illness. This is of particular concern, given increasing indications that sewer leakage is ubiquitous in urban areas, yet not typically fully accounted for during TMDL development. Uncertainty analysis suggested the accuracy of risk estimates would be improved by more detailed knowledge of site-specific pathogen presence and densities. While previous applications of the QMRA process to impaired waterways have mostly focused on single storm events or hypothetical situations, the continuous modeling framework presented in this study could be integrated into long-term water quality management planning, especially the United States' TMDL program, providing greater clarity to

Coupling a continuous watershed-scale microbial fate and transport model with a stochastic dose-response model to estimate risk of illness in an urban watershed

International Nuclear Information System (INIS)

Liao, Hehuan; Krometis, Leigh-Anne H.; Kline, Karen

2016-01-01

Within the United States, elevated levels of fecal indicator bacteria (FIB) remain the leading cause of surface water-quality impairments requiring formal remediation plans under the federal Clean Water Act's Total Maximum Daily Load (TMDL) program. The sufficiency of compliance with numerical FIB criteria as the targeted endpoint of TMDL remediation plans may be questionable given poor correlations between FIB and pathogenic microorganisms and varying degrees of risk associated with exposure to different fecal pollution sources (e.g. human vs animal). The present study linked a watershed-scale FIB fate and transport model with a dose-response model to continuously predict human health risks via quantitative microbial risk assessment (QMRA), for comparison to regulatory benchmarks. This process permitted comparison of risks associated with different fecal pollution sources in an impaired urban watershed in order to identify remediation priorities. Results indicate that total human illness risks were consistently higher than the regulatory benchmark of 36 illnesses/1000 people for the study watershed, even when the predicted FIB levels were in compliance with the Escherichia coli geometric mean standard of 126 CFU/100 mL. Sanitary sewer overflows were associated with the greatest risk of illness. This is of particular concern, given increasing indications that sewer leakage is ubiquitous in urban areas, yet not typically fully accounted for during TMDL development. Uncertainty analysis suggested the accuracy of risk estimates would be improved by more detailed knowledge of site-specific pathogen presence and densities. While previous applications of the QMRA process to impaired waterways have mostly focused on single storm events or hypothetical situations, the continuous modeling framework presented in this study could be integrated into long-term water quality management planning, especially the United States' TMDL program, providing greater clarity to watershed

Watershed Controls on the Proper Scale of Economic Markets for Pollution Reduction

Science.gov (United States)

Rigby, J.; Doyle, M. W.; Yates, A.

2010-12-01

Markets for tradable discharge permits (TDPs) are an increasingly popular policy instrument for obtaining cost-effective nutrient reduction targets across watersheds. Such markets are also an emerging, dynamic coupling between economic institutions and stream hydrology/biogeochemistry as trading markets become explicit determinants for the spatial distribution of stream nutrient loads. A central problem in any environmental market program is setting the size of the market, as there are distinct trade-offs for large versus small markets. While the overall cost-effectiveness of permit trading increases with the size of the market, the potential for localized and highly damaging nutrient concentrations, or “hotspots”, also increases. Smaller market size reduces the potential for hot spots by dispersing the location of trades, but this may increase the net costs of water quality compliance significantly through both the restriction of possible trading partners and price manipulation by market participants. This project couples a microeconomic model for TDPs (based on possible configurations of mutually exclusive trading zones within the basin) with a semi-distributed water quality model to examine watershed controls on the configuration and scale of such markets. Our results show a wide variation in total annual cost of pollution abatement based on choice of market design -- often with large differences in cost between very similar configurations. This framework is also applied to a 10-member trading program among wastewater treatment plants in the Neuse River, NC, in order to assess (1) the optimum market design for the Upper Neuse basin and (2) how these costs compare with expected costs under alternative market structures (e.g., trading ratio system) and (3) the cost improvements over traditional command-and-control regulatory frameworks. We find that the optimal zone configuration is almost always a lower cost option when compared to a trading ratio scheme and

Coupling a continuous watershed-scale microbial fate and transport model with a stochastic dose-response model to estimate risk of illness in an urban watershed.

Science.gov (United States)

Liao, Hehuan; Krometis, Leigh-Anne H; Kline, Karen

2016-05-01

Within the United States, elevated levels of fecal indicator bacteria (FIB) remain the leading cause of surface water-quality impairments requiring formal remediation plans under the federal Clean Water Act's Total Maximum Daily Load (TMDL) program. The sufficiency of compliance with numerical FIB criteria as the targeted endpoint of TMDL remediation plans may be questionable given poor correlations between FIB and pathogenic microorganisms and varying degrees of risk associated with exposure to different fecal pollution sources (e.g. human vs animal). The present study linked a watershed-scale FIB fate and transport model with a dose-response model to continuously predict human health risks via quantitative microbial risk assessment (QMRA), for comparison to regulatory benchmarks. This process permitted comparison of risks associated with different fecal pollution sources in an impaired urban watershed in order to identify remediation priorities. Results indicate that total human illness risks were consistently higher than the regulatory benchmark of 36 illnesses/1000 people for the study watershed, even when the predicted FIB levels were in compliance with the Escherichia coli geometric mean standard of 126CFU/100mL. Sanitary sewer overflows were associated with the greatest risk of illness. This is of particular concern, given increasing indications that sewer leakage is ubiquitous in urban areas, yet not typically fully accounted for during TMDL development. Uncertainty analysis suggested the accuracy of risk estimates would be improved by more detailed knowledge of site-specific pathogen presence and densities. While previous applications of the QMRA process to impaired waterways have mostly focused on single storm events or hypothetical situations, the continuous modeling framework presented in this study could be integrated into long-term water quality management planning, especially the United States' TMDL program, providing greater clarity to watershed

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

Science.gov (United States)

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.

Air Pollution and Watershed Research in the Central Sierra Nevada of California: Nitrogen and Ozone

Directory of Open Access Journals (Sweden)

Carolyn Hunsaker

2007-01-01

Full Text Available Maintaining healthy forests is the major objective for the Forest Service scientists and managers working for the U.S. Department of Agriculture. Air pollution, specifically ozone (O3 and nitrogenous (N air pollutants, may severely affect the health of forest ecosystems in the western U.S. Thus, the monitoring of air pollution concentration and deposition levels, as well as studies focused on understanding effects mechanisms, are essential for evaluation of risks associated with their presence. Such information is essential for development of proper management strategies for maintaining clean air, clean water, and healthy ecosystems on land managed by the Forest Service. We report on two years of research in the central Sierra Nevada of California, a semi-arid forest at elevations of 1100–2700 m. Information on O3 and N air pollutants is obtained from a network of 18 passive samplers. We relate the atmospheric N concentration to N concentrations in streams, shallow soil water, and bulk deposition collectors within the Kings River Experimental Watershed. This watershed also contains an intensive site that is part of a recent Forest Service effort to calculate critical loads for N, sulfur, and acidity to forest ecosystems. The passive sampler design allows for extensive spatial measurements while the watershed experiment provides intensive spatial data for future analysis of ecosystem processes.

Application of integrated GIS and multimedia modeling on NPS pollution evaluation.

Science.gov (United States)

Lin, C E; Kao, C M; Lai, Y C; Shan, W L; Wu, C Y

2009-11-01

In Taiwan, nonpoint source (NPS) pollution is one of the major causes of the impairment of surface waters. I-Liao Creek, located in southern Taiwan, flows approximately 90 km and drains toward the Kaoping River. Field investigation results indicate that NPS pollution from agricultural activities is one of the main water pollution sources in the I-Liao Creek Basin. Assessing the potential of NPS pollution to assist in the planning of best management practice (BMP) is significant for improving pollution prevention and control in the I-Liao Creek Basin. In this study, land use identification in the I-Liao Creek Basin was performed by properly integrating the skills of geographic information system (GIS) and global positioning system (GPS). In this analysis, 35 types of land use patterns in the watershed area of the basin are classified with the aid of Erdas Imagine process system and ArcView GIS system. Results indicate that betel palm farms, orchard farms, and tea gardens dominate the farmland areas in the basin, and are scattered around on both sides of the river corridor. An integrated watershed management model (IWMM) was applied for simulating the water quality and evaluating NPS pollutant loads to the I-Liao Creek. The model was calibrated and verified with collected water quality and soil data, and was used to investigate potential NPS pollution management plans. Simulated results indicate that NPS pollution has significant contributions to the nutrient loads to the I-Liao Creek during the wet season. Results also reveal that NPS pollution plays an important role in the deterioration of downstream water quality and caused significant increase in nutrient loads into the basin's water bodies. Simulated results show that source control, land use management, and grassy buffer strip are applicable and feasible BMPs for NPS nutrient loads reduction. GIS system is an important method for land use identification and waste load estimation in the basin. Linking the

Fena Valley Reservoir watershed and water-balance model updates and expansion of watershed modeling to southern Guam

Science.gov (United States)

Rosa, Sarah N.; Hay, Lauren E.

2017-12-01

In 2014, the U.S. Geological Survey, in cooperation with the U.S. Department of Defense’s Strategic Environmental Research and Development Program, initiated a project to evaluate the potential impacts of projected climate-change on Department of Defense installations that rely on Guam’s water resources. A major task of that project was to develop a watershed model of southern Guam and a water-balance model for the Fena Valley Reservoir. The southern Guam watershed model provides a physically based tool to estimate surface-water availability in southern Guam. The U.S. Geological Survey’s Precipitation Runoff Modeling System, PRMS-IV, was used to construct the watershed model. The PRMS-IV code simulates different parts of the hydrologic cycle based on a set of user-defined modules. The southern Guam watershed model was constructed by updating a watershed model for the Fena Valley watersheds, and expanding the modeled area to include all of southern Guam. The Fena Valley watershed model was combined with a previously developed, but recently updated and recalibrated Fena Valley Reservoir water-balance model.Two important surface-water resources for the U.S. Navy and the citizens of Guam were modeled in this study; the extended model now includes the Ugum River watershed and improves upon the previous model of the Fena Valley watersheds. Surface water from the Ugum River watershed is diverted and treated for drinking water, and the Fena Valley watersheds feed the largest surface-water reservoir on Guam. The southern Guam watershed model performed “very good,” according to the criteria of Moriasi and others (2007), in the Ugum River watershed above Talofofo Falls with monthly Nash-Sutcliffe efficiency statistic values of 0.97 for the calibration period and 0.93 for the verification period (a value of 1.0 represents perfect model fit). In the Fena Valley watershed, monthly simulated streamflow volumes from the watershed model compared reasonably well with the

[Analysis on nitrogen and phosphorus loading of non-point sources in Shiqiao river watershed based on L-THIA model].

Science.gov (United States)

Li, Kai; Zeng, Fan-Tang; Fang, Huai-Yang; Lin, Shu

2013-11-01

Based on the Long-term Hydrological Impact Assessment (L-THIA) model, the effect of land use and rainfall change on nitrogen and phosphorus loading of non-point sources in Shiqiao river watershed was analyzed. The parameters in L-THIA model were revised according to the data recorded in the scene of runoff plots, which were set up in the watershed. The results showed that the distribution of areas with high pollution load was mainly concentrated in agricultural land and urban land. Agricultural land was the biggest contributor to nitrogen and phosphorus load. From 1995 to 2010, the load of major pollutants, namely TN and TP, showed an obviously increasing trend with increase rates of 17.91% and 25.30%, respectively. With the urbanization in the watershed, urban land increased rapidly and its area proportion reached 43.94%. The contribution of urban land to nitrogen and phosphorus load was over 40% in 2010. This was the main reason why pollution load still increased obviously while the agricultural land decreased greatly in the past 15 years. The rainfall occurred in the watershed was mainly concentrated in the flood season, so the nitrogen and phosphorus load of the flood season was far higher than that of the non-flood season and the proportion accounting for the whole year was over 85%. Pearson regression analysis between pollution load and the frequency of different patterns of rainfall demonstrated that rainfall exceeding 20 mm in a day was the main rainfall type causing non-point source pollution.

Reduction Assessment of Agricultural Non-Point Source Pollutant Loading

OpenAIRE

Fu, YiCheng; Zang, Wenbin; Zhang, Jian; Wang, Hongtao; Zhang, Chunling; Shi, Wanli

2018-01-01

NPS (Non-point source) pollution has become a key impact element to watershed environment at present. With the development of technology, application of models to control NPS pollution has become a very common practice for resource management and Pollutant reduction control in the watershed scale of China. The SWAT (Soil and Water Assessment Tool) model is a semi-conceptual model, which was put forward to estimate pollutant production & the influences on water quantity-quality under different...

Application of Watershed Scale Models to Predict Nitrogen Loading From Coastal Plain Watersheds

Science.gov (United States)

George M. Chescheir; Glenn P Fernandez; R. Wayne Skaggs; Devendra M. Amatya

2004-01-01

DRAINMOD-based watershed models have been developed and tested using data collected from an intensively instrumented research site on Kendricks Creek watershed near Plymouth. NC. These models were applied to simulate the hydrology and nitrate nitrogen (NO3-N) loading from two other watersheds in the Coastal Plain of North Carolina, the 11600 ha Chicod Creek watershed...

A coupled model approach to reduce nonpoint-source pollution resulting from predicted urban growth: A case study in the Ambos Nogales watershed

Science.gov (United States)

Norman, L.M.; Guertin, D.P.; Feller, M.

2008-01-01

The development of new approaches for understanding processes of urban development and their environmental effects, as well as strategies for sustainable management, is essential in expanding metropolitan areas. This study illustrates the potential of linking urban growth and watershed models to identify problem areas and support long-term watershed planning. Sediment is a primary source of nonpoint-source pollution in surface waters. In urban areas, sediment is intermingled with other surface debris in transport. In an effort to forecast the effects of development on surface-water quality, changes predicted in urban areas by the SLEUTH urban growth model were applied in the context of erosion-sedimentation models (Universal Soil Loss Equation and Spatially Explicit Delivery Models). The models are used to simulate the effect of excluding hot-spot areas of erosion and sedimentation from future urban growth and to predict the impacts of alternative erosion-control scenarios. Ambos Nogales, meaning 'both Nogaleses,' is a name commonly used for the twin border cities of Nogales, Arizona and Nogales, Sonora, Mexico. The Ambos Nogales watershed has experienced a decrease in water quality as a result of urban development in the twin-city area. Population growth rates in Ambos Nogales are high and the resources set in place to accommodate the rapid population influx will soon become overburdened. Because of its remote location and binational governance, monitoring and planning across the border is compromised. One scenario described in this research portrays an improvement in water quality through the identification of high-risk areas using models that simulate their protection from development and replanting with native grasses, while permitting the predicted and inevitable growth elsewhere. This is meant to add to the body of knowledge about forecasting the impact potential of urbanization on sediment delivery to streams for sustainable development, which can be

Differentiating impacts of land use changes from pasture management in a CEAP watershed using the SWAT model

Science.gov (United States)

Due to intensive farm practices, nonpoint-source (NPS) pollution has become one of the most challenging environmental problems in agricultural and mixed land use watersheds. Usually, various conservation practices are implemented in the watershed to control the NPS pollution problem. However, land u...

Agroforestry buffers for nonpoint source pollution reductions from agricultural watersheds.

Science.gov (United States)

Udawatta, Ranjith P; Garrett, Harold E; Kallenbach, Robert

2011-01-01

Despite increased attention and demand for the adoption of agroforestry practices throughout the world, rigorous long-term scientific studies confirming environmental benefits from the use of agroforestry practices are limited. The objective was to examine nonpoint-source pollution (NPSP) reduction as influenced by agroforestry buffers in watersheds under grazing and row crop management. The grazing study consists of six watersheds in the Central Mississippi Valley wooded slopes and the row crop study site consists of three watersheds in a paired watershed design in Central Claypan areas. Runoff water samples were analyzed for sediment, total nitrogen (TN), and total phosphorus (TP) for the 2004 to 2008 period. Results indicate that agroforestry and grass buffers on grazed and row crop management sites significantly reduce runoff, sediment, TN, and TP losses to streams. Buffers in association with grazing and row crop management reduced runoff by 49 and 19%, respectively, during the study period as compared with respective control treatments. Average sediment loss for grazing and row crop management systems was 13.8 and 17.9 kg ha yr, respectively. On average, grass and agroforestry buffers reduced sediment, TN, and TP losses by 32, 42, and 46% compared with the control treatments. Buffers were more effective in the grazing management practice than row crop management practice. These differences could in part be attributed to the differences in soils, management, and landscape features. Results from this study strongly indicate that agroforestry and grass buffers can be designed to improve water quality while minimizing the amount of land taken out of production. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

A Semi-Infinite Interval-Stochastic Risk Management Model for River Water Pollution Control under Uncertainty

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Jing Liu

2017-05-01

Full Text Available In this study, a semi-infinite interval-stochastic risk management (SIRM model is developed for river water pollution control, where various policy scenarios are explored in response to economic penalties due to randomness and functional intervals. SIRM can also control the variability of the recourse cost as well as capture the notion of risk in stochastic programming. Then, the SIRM model is applied to water pollution control of the Xiangxihe watershed. Tradeoffs between risks and benefits are evaluated, indicating any change in the targeted benefit and risk level would yield varied expected benefits. Results disclose that the uncertainty of system components and risk preference of decision makers have significant effects on the watershed's production generation pattern and pollutant control schemes as well as system benefit. Decision makers with risk-aversive attitude would accept a lower system benefit (with lower production level and pollutant discharge; a policy based on risk-neutral attitude would lead to a higher system benefit (with higher production level and pollutant discharge. The findings can facilitate the decision makers in identifying desired product generation plans in association with financial risk minimization and pollution mitigation.

Multi-source water pollution in the Upper Citarum watershed, Indonesia, with special reference to its spatiotemporal variation.

Science.gov (United States)

Parikesit; Salim, H; Triharyanto, E; Gunawan, B; Sunardi; Abdoellah, O S; Ohtsuka, R

2005-01-01

The Citarum River in West Java is the largest water supplier to the Saguling Dam, which plays a major role in electric power generation for the entire Java Island and is used for the aquaculture of marketed fish. To elucidate the extent of degradation in water quality and its causes in the Upper Citarum watershed, physical, chemical and biological parameters for water samples collected from various sites were analyzed. The results demonstrate large site-to-site variations in water qualities and pollutant loads derived from various human activities such as agriculture, cattle raising and the textile industry. To halt worsening conditions of the Citarum watershed, integrated mitigation efforts should be made, taking biophysical pollution mechanisms and local socioeconomic conditions into account.

Pre- and post-fire pollutant loads in an urban fringe watershed in Southern California.

Science.gov (United States)

Burke, M P; Hogue, T S; Kinoshita, A M; Barco, J; Wessel, C; Stein, E D

2013-12-01

Post-fire runoff has the potential to be a large source of contaminants to downstream areas. However, the magnitude of this effect in urban fringe watersheds adjacent to large sources of airborne contaminants is not well documented. The current study investigates the impacts of wildfire on stormwater contaminant loading from the upper Arroyo Seco watershed, burned in 2009. This watershed is adjacent to the Greater Los Angeles, CA, USA area and has not burned in over 60 years. Consequently, it acts as a sink for regional urban pollutants and presents an opportunity to study the impacts of wildfire. Pre- and post-fire storm samples were collected and analyzed for basic cations, trace metals, and total suspended solids. The loss of vegetation and changes in soil properties from the fire greatly increased the magnitude of storm runoff, resulting in sediment-laden floods carrying high concentrations of particulate-bound constituents. Post-fire concentrations and loads were up to three orders of magnitude greater than pre-fire values for many trace metals, including lead and cadmium. A shift was also observed in the timing of chemical delivery, where maximum suspended sediment, trace metal, and cation concentrations coincided with, rather than preceded, peak discharge in the post-fire runoff, amplifying the fire's impacts on mass loading. The results emphasize the importance of sediment delivery as a primary mechanism for post-fire contaminant transport and suggest that traditional management practices that focus on treating only the early portion of storm runoff may be less effective following wildfire. We also advocate that watersheds impacted by regional urban pollutants have the potential to pose significant risk for downstream communities and ecosystems after fire.

Modeling soil erosion in a watershed

OpenAIRE

Lanuza, R.

1999-01-01

Most erosion models have been developed based on a plot scale and have limited application to a watershed due to the differences in aerial scale. In order to address this limitation, a GIS-assisted methodology for modeling soil erosion was developed using PCRaster to predict the rate of soil erosion at watershed level; identify the location of erosion prone areas; and analyze the impact of landuse changes on soil erosion. The general methodology of desktop modeling or soil erosion at watershe...

Assessment of Runoff and Sediment Yields Using the AnnAGNPS Model in a Three-Gorge Watershed of China

Directory of Open Access Journals (Sweden)

Hongwei Nan

2012-05-01

Full Text Available Soil erosion has been recognized as one of the major threats to our environment and water quality worldwide, especially in China. To mitigate nonpoint source water quality problems caused by soil erosion, best management practices (BMPs and/or conservation programs have been adopted. Watershed models, such as the Annualized Agricultural Non-Point Source Pollutant Loading model (AnnAGNPS, have been developed to aid in the evaluation of watershed response to watershed management practices. The model has been applied worldwide and proven to be a very effective tool in identifying the critical areas which had serious erosion, and in aiding in decision-making processes for adopting BMPs and/or conservation programs so that cost/benefit can be maximized and non-point source pollution control can be achieved in the most efficient way. The main goal of this study was to assess the characteristics of soil erosion, sediment and sediment delivery of a watershed so that effective conservation measures can be implemented. To achieve the overall objective of this study, all necessary data for the 4,184 km² Daning River watershed in the Three-Gorge region of the Yangtze River of China were assembled. The model was calibrated using observed monthly runoff from 1998 to 1999 (Nash-Sutcliffe coefficient of efficiency of 0.94 and R² of 0.94 and validated using the observed monthly runoff from 2003 to 2005 (Nash-Sutcliffe coefficient of efficiency of 0.93 and R² of 0.93. Additionally, the model was validated using annual average sediment of 2000–2002 (relative error of −0.34 and 2003–2004 (relative error of 0.18 at Wuxi station. Post validation simulation showed that approximately 48% of the watershed was under the soil loss tolerance released by the Ministry of Water Resources of China (500 t·km⁻²·y⁻¹. However, 8% of the watershed had soil erosion of exceeding 5,000 t·km⁻²

Model My Watershed - A Robust Online App to Enable Citizen Scientists to Model Watershed Hydrology and Water Quality at Regulatory-Level Standards

Science.gov (United States)

Daniels, M.; Kerlin, S.; Arscott, D.

2017-12-01

Citizen-based watershed monitoring has historically lacked scientific rigor and geographic scope due to limitation in access to watershed-level data and the high level skills and resources required to adequately model watershed dynamics. Public access to watershed information is currently routed through a variety of governmental data portals and often requires advanced geospatial skills to collect and present in useable forms. At the same time, tremendous financial resources are being invested in watershed restoration and management efforts, and often these resources pass through local stakeholder groups such as conservation NGO, watershed interest groups, and local municipalities without extensive hydrologic knowledge or access to sophisticated modeling resources. Even governmental agencies struggle to understand how to best steer or prioritize restoration investments. A new app, Model My Watershed, was built to improve access to watershed data and modeling capabilities in a fast, accessible, free web-app format. Working across the contiguous United States, the Model My Watershed app provides land cover, soils, aerial imagery and relief, watershed delineation, and stream network delineation. Users can model watersheds or areas of interest and create management scenarios to evaluate implementation of land cover changes and best management practice implementation with both hydrologic and water quality outputs that meet TMDL regulatory standards.

Asotin Creek Model Watershed Plan

Energy Technology Data Exchange (ETDEWEB)

Browne, D.; Holzmiller, J.; Koch, F.; Polumsky, S.; Schlee, D.; Thiessen, G.; Johnson, C.

1995-04-01

The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ``Strategy for Salmon``. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity. The watershed coordinator for the Asotin County Conservation District led a locally based process that combined local concerns and knowledge with technology from several agencies to produce the Asotin Creek Model Watershed Plan.

Evaluasi Aliran Permukaan Erosi dan Sedimentasi di SUB DAS Cisadane Hulu dengan Menggunakan Model AGNPS (Agricultural Non Point Source Pollution Model

Directory of Open Access Journals (Sweden)

Sukandi Sukartaatmadja

2006-12-01

Full Text Available Composition of a good watershed management planning needs accurate information about erosion, runoff and its quality, so that its model for them, middle term and long term goal can be projected. The model had been used is AGNPS (agricultural non point source pollution model is developed by Robert A. Young, Charles A. Onstad, David D. Bosch. And Wayne P. Anderson in 1987. The Objective of this reseacrh is to looked for the effect of soil conservation had been done with rehabilitation activities plan to watershed condition using AGNPS model wich is divided into two plans. The effect of soil conservation activieties by a better plan wich is suited with Upper Cisadane Watershed could decreased runoff volume, runoff peak rate, annual erosion and sediment weight into 20% so that it could repaired the condition of Upper Cisadane Watershed wich is dangerouse before.

APEX simulation: environmental benefits of agroforestry and grass buffers on corn-soybean watersheds

Science.gov (United States)

The Agricultural Policy Environmental Extender (APEX) model has the ability to simulate the effects of vegetative filter strips on runoff and pollutant loadings from agricultural watersheds. The objectives of this study were to calibrate and validate the APEX model for three adjacent watersheds and...

Watershed-scale modeling on the fate and transport of polycyclic aromatic hydrocarbons (PAHs)

International Nuclear Information System (INIS)

Ligaray, Mayzonee; Baek, Sang Soo; Kwon, Hye-Ok; Choi, Sung-Deuk; Cho, Kyung Hwa

2016-01-01

PAHs are potentially carcinogenic substances that are persistent in the environment. Increasing concentrations of PAHs were observed due to rapid urbanization, thus; monitoring PAHs concentrations is necessary. However, it is expensive to conduct intensive monitoring activities of a large number of PAHs. This study addressed this issue by developing a multimedia model coupled with a hydrological model (i.e., Soil and Water Assessment Tool (SWAT)) for Taehwa River (TR) watershed in Ulsan, the industrial capital of South Korea. The hydrologic module of the SWAT was calibrated, and further used to simulate the fate and transport of PAHs in soil and waterbody. The model demonstrated that the temporal or seasonal variation of PAHs in soil and waterbody can be well reproduced. Meanwhile, the spatial distribution of PAHs showed that urban areas in TR watershed have the highest PAH loadings compared to rural areas. Sensitivity analyses of the PAH soil and PAH water parameters were also able to determine the critical processes in TR watershed: degradation, deposition, volatilization, and wash off mechanism. We hope that this model will be able to aid the stakeholders in: regulating PAH concentrations emitted by various sources; and also apply the model to other Persistent Organic Pollutants (POPs).

Watershed-scale modeling on the fate and transport of polycyclic aromatic hydrocarbons (PAHs)

Energy Technology Data Exchange (ETDEWEB)

Ligaray, Mayzonee; Baek, Sang Soo [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan 44919 (Korea, Republic of); Kwon, Hye-Ok [Disaster Scientific Investigation Division, National Disaster Management Research Institute, 365 Jongga-ro Jung-gu, Ulsan 44538 (Korea, Republic of); Choi, Sung-Deuk, E-mail: sdchoi@unist.ac.kr [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan 44919 (Korea, Republic of); Cho, Kyung Hwa, E-mail: khcho@unist.ac.kr [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan 44919 (Korea, Republic of)

2016-12-15

PAHs are potentially carcinogenic substances that are persistent in the environment. Increasing concentrations of PAHs were observed due to rapid urbanization, thus; monitoring PAHs concentrations is necessary. However, it is expensive to conduct intensive monitoring activities of a large number of PAHs. This study addressed this issue by developing a multimedia model coupled with a hydrological model (i.e., Soil and Water Assessment Tool (SWAT)) for Taehwa River (TR) watershed in Ulsan, the industrial capital of South Korea. The hydrologic module of the SWAT was calibrated, and further used to simulate the fate and transport of PAHs in soil and waterbody. The model demonstrated that the temporal or seasonal variation of PAHs in soil and waterbody can be well reproduced. Meanwhile, the spatial distribution of PAHs showed that urban areas in TR watershed have the highest PAH loadings compared to rural areas. Sensitivity analyses of the PAH soil and PAH water parameters were also able to determine the critical processes in TR watershed: degradation, deposition, volatilization, and wash off mechanism. We hope that this model will be able to aid the stakeholders in: regulating PAH concentrations emitted by various sources; and also apply the model to other Persistent Organic Pollutants (POPs).

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Regionalization of SWAT Model Parameters for Use in Ungauged Watersheds

Directory of Open Access Journals (Sweden)

Indrajeet Chaubey

2010-11-01

Full Text Available There has been a steady shift towards modeling and model-based approaches as primary methods of assessing watershed response to hydrologic inputs and land management, and of quantifying watershed-wide best management practice (BMP effectiveness. Watershed models often require some degree of calibration and validation to achieve adequate watershed and therefore BMP representation. This is, however, only possible for gauged watersheds. There are many watersheds for which there are very little or no monitoring data available, thus the question as to whether it would be possible to extend and/or generalize model parameters obtained through calibration of gauged watersheds to ungauged watersheds within the same region. This study explored the possibility of developing regionalized model parameter sets for use in ungauged watersheds. The study evaluated two regionalization methods: global averaging, and regression-based parameters, on the SWAT model using data from priority watersheds in Arkansas. Resulting parameters were tested and model performance determined on three gauged watersheds. Nash-Sutcliffe efficiencies (NS for stream flow obtained using regression-based parameters (0.53–0.83 compared well with corresponding values obtained through model calibration (0.45–0.90. Model performance obtained using global averaged parameter values was also generally acceptable (0.4 ≤ NS ≤ 0.75. Results from this study indicate that regionalized parameter sets for the SWAT model can be obtained and used for making satisfactory hydrologic response predictions in ungauged watersheds.

Uncertainty in BMP evaluation and optimization for watershed management

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Chaubey, I.; Cibin, R.; Sudheer, K.; Her, Y.

2012-12-01

Use of computer simulation models have increased substantially to make watershed management decisions and to develop strategies for water quality improvements. These models are often used to evaluate potential benefits of various best management practices (BMPs) for reducing losses of pollutants from sources areas into receiving waterbodies. Similarly, use of simulation models in optimizing selection and placement of best management practices under single (maximization of crop production or minimization of pollutant transport) and multiple objective functions has increased recently. One of the limitations of the currently available assessment and optimization approaches is that the BMP strategies are considered deterministic. Uncertainties in input data (e.g. precipitation, streamflow, sediment, nutrient and pesticide losses measured, land use) and model parameters may result in considerable uncertainty in watershed response under various BMP options. We have developed and evaluated options to include uncertainty in BMP evaluation and optimization for watershed management. We have also applied these methods to evaluate uncertainty in ecosystem services from mixed land use watersheds. In this presentation, we will discuss methods to to quantify uncertainties in BMP assessment and optimization solutions due to uncertainties in model inputs and parameters. We have used a watershed model (Soil and Water Assessment Tool or SWAT) to simulate the hydrology and water quality in mixed land use watershed located in Midwest USA. The SWAT model was also used to represent various BMPs in the watershed needed to improve water quality. SWAT model parameters, land use change parameters, and climate change parameters were considered uncertain. It was observed that model parameters, land use and climate changes resulted in considerable uncertainties in BMP performance in reducing P, N, and sediment loads. In addition, climate change scenarios also affected uncertainties in SWAT

Mud, models, and managers: Reaching consensus on a watershed strategy for sediment load reduction

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Wilcock, P. R.; Cho, S. J.; Gran, K.; Belmont, P.; Hobbs, B. F.; Heitkamp, B.; Marr, J. D.

2017-12-01

Agricultural nonpoint source sediment pollution is a leading cause of impairment of U.S. waters. Sediment sources are often on private land, such that solutions require not only considerable investment, but broad acceptance among landowners. We present the story of a participatory modeling exercise whose goal was to develop a consensus strategy for reducing sediment loading from the Greater Blue Earth River Basin, a large (9,200 km2) watershed in southern Minnesota dominated by row crop agriculture. The Collaborative for Sediment Source Reduction was a stakeholder group of farmers, industry representatives, conservation groups, and regulatory agencies. We used a participatory modeling approach to promote understanding of the problem, to define the scope of solutions acceptable to farmers, to develop confidence in a watershed model, and to reach consensus on a watershed strategy. We found that no existing watershed model could provide a reliable estimate of sediment response to management actions and developed a purpose-built model that could provide reliable, transparent, and fast answers. Because increased stream flow was identified as an important driver of sediment loading, the model and solutions included both hydrologic and sediment transport components. The model was based on an annual sediment budget with management actions serving to proportionally reduce both sediment sources and sediment delivery. Importantly, the model was developed in collaboration with stakeholders, such that a shared understanding emerged regarding of the modeling challenges and the reliability of information used to strongly constrain model output. The simplicity of the modeling approach supported stakeholder engagement and understanding, thereby lowering the social barrier between expert modeler and concerned stakeholder. The consensus strategy focused on water storage higher in the watershed in order to reduce river discharge and the large supply of sediment from near

Model My Watershed: A high-performance cloud application for public engagement, watershed modeling and conservation decision support

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Aufdenkampe, A. K.; Tarboton, D. G.; Horsburgh, J. S.; Mayorga, E.; McFarland, M.; Robbins, A.; Haag, S.; Shokoufandeh, A.; Evans, B. M.; Arscott, D. B.

2017-12-01

The Model My Watershed Web app (https://app.wikiwatershed.org/) and the BiG-CZ Data Portal (http://portal.bigcz.org/) and are web applications that share a common codebase and a common goal to deliver high-performance discovery, visualization and analysis of geospatial data in an intuitive user interface in web browser. Model My Watershed (MMW) was designed as a decision support system for watershed conservation implementation. BiG CZ Data Portal was designed to provide context and background data for research sites. Users begin by creating an Area of Interest, via an automated watershed delineation tool, a free draw tool, selection of a predefined area such as a county or USGS Hydrological Unit (HUC), or uploading a custom polygon. Both Web apps visualize and provide summary statistics of land use, soil groups, streams, climate and other geospatial information. MMW then allows users to run a watershed model to simulate different scenarios of human impacts on stormwater runoff and water-quality. BiG CZ Data Portal allows users to search for scientific and monitoring data within the Area of Interest, which also serves as a prototype for the upcoming Monitor My Watershed web app. Both systems integrate with CUAHSI cyberinfrastructure, including visualizing observational data from CUAHSI Water Data Center and storing user data via CUAHSI HydroShare. Both systems also integrate with the new EnviroDIY Water Quality Data Portal (http://data.envirodiy.org/), a system for crowd-sourcing environmental monitoring data using open-source sensor stations (http://envirodiy.org/mayfly/) and based on the Observations Data Model v2.

A pollution fate and transport model application in a semi-arid region: Is some number better than no number?

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Özcan, Zeynep; Başkan, Oğuz; Düzgün, H Şebnem; Kentel, Elçin; Alp, Emre

2017-10-01

Fate and transport models are powerful tools that aid authorities in making unbiased decisions for developing sustainable management strategies. Application of pollution fate and transport models in semi-arid regions has been challenging because of unique hydrological characteristics and limited data availability. Significant temporal and spatial variability in rainfall events, complex interactions between soil, vegetation and topography, and limited water quality and hydrological data due to insufficient monitoring network make it a difficult task to develop reliable models in semi-arid regions. The performances of these models govern the final use of the outcomes such as policy implementation, screening, economical analysis, etc. In this study, a deterministic distributed fate and transport model, SWAT, is applied in Lake Mogan Watershed, a semi-arid region dominated by dry agricultural practices, to estimate nutrient loads and to develop the water budget of the watershed. To minimize the discrepancy due to limited availability of historical water quality data extensive efforts were placed in collecting site-specific data for model inputs such as soil properties, agricultural practice information and land use. Moreover, calibration parameter ranges suggested in the literature are utilized during calibration in order to obtain more realistic representation of Lake Mogan Watershed in the model. Model performance is evaluated using comparisons of the measured data with 95%CI for the simulated data and comparison of unit pollution load estimations with those provided in the literature for similar catchments, in addition to commonly used evaluation criteria such as Nash-Sutcliffe simulation efficiency, coefficient of determination and percent bias. These evaluations demonstrated that even though the model prediction power is not high according to the commonly used model performance criteria, the calibrated model may provide useful information in the comparison of the

Subdivision of Texas watersheds for hydrologic modeling.

Science.gov (United States)

2009-06-01

The purpose of this report is to present a set of findings and examples for subdivision of watersheds for hydrologic modeling. Three approaches were used to examine the impact of watershed subdivision on modeled hydrologic response: (1) An equal-area...

Evapotranspiration sensitivity to air temperature across a snow-influenced watershed: Space-for-time substitution versus integrated watershed modeling

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Jepsen, S. M.; Harmon, T. C.; Ficklin, D. L.; Molotch, N. P.; Guan, B.

2018-01-01

Changes in long-term, montane actual evapotranspiration (ET) in response to climate change could impact future water supplies and forest species composition. For scenarios of atmospheric warming, predicted changes in long-term ET tend to differ between studies using space-for-time substitution (STS) models and integrated watershed models, and the influence of spatially varying factors on these differences is unclear. To examine this, we compared warming-induced (+2 to +6 °C) changes in ET simulated by an STS model and an integrated watershed model across zones of elevation, substrate available water capacity, and slope in the snow-influenced upper San Joaquin River watershed, Sierra Nevada, USA. We used the Soil Water and Assessment Tool (SWAT) for the watershed modeling and a Budyko-type relationship for the STS modeling. Spatially averaged increases in ET from the STS model increasingly surpassed those from the SWAT model in the higher elevation zones of the watershed, resulting in 2.3-2.6 times greater values from the STS model at the watershed scale. In sparse, deep colluvium or glacial soils on gentle slopes, the SWAT model produced ET increases exceeding those from the STS model. However, watershed areas associated with these conditions were too localized for SWAT to produce spatially averaged ET-gains comparable to the STS model. The SWAT model results nevertheless demonstrate that such soils on high-elevation, gentle slopes will form ET "hot spots" exhibiting disproportionately large increases in ET, and concomitant reductions in runoff yield, in response to warming. Predicted ET responses to warming from STS models and integrated watershed models may, in general, substantially differ (e.g., factor of 2-3) for snow-influenced watersheds exhibiting an elevational gradient in substrate water holding capacity and slope. Long-term water supplies in these settings may therefore be more resilient to warming than STS model predictions would suggest.

Simulating land management options to reduce nitrate pollution in an agricultural watershed dominated by an alluvial aquifer.

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Cerro, Itsasne; Antigüedad, Iñaki; Srinavasan, Raghavan; Sauvage, Sabine; Volk, Martin; Sanchez-Perez, José Miguel

2014-01-01

The study area (Alegria watershed, Basque Country, Northern Spain) considered here is influenced by an important alluvial aquifer that plays a significant role in nitrate pollution from agricultural land use and management practices. Nitrates are transported primarily from the soil to the river through the alluvial aquifer. The agricultural activity covers 75% of the watershed and is located in a nitrate-vulnerable zone. The main objective of the study was to find land management options for water pollution abatement by using model systems. In a first step, the SWAT model was applied to simulate discharge and nitrate load in stream flow at the outlet of the catchment for the period between October 2009 and June 2011. The LOADEST program was used to estimate the daily nitrate load from measured nitrate concentration. We achieved satisfactory simulation results for discharge and nitrate loads at monthly and daily time steps. The results revealed clear variations in the seasons: higher nitrate loads were achieved for winter (20,000 kg mo NO-N), and lower nitrate loads were simulated for the summer (model was used to evaluate the long-term effects of best management practices (BMPs) for a 50-yr period by maintaining actual agricultural practices, reducing fertilizer application by 20%, splitting applications (same total N but applied over the growing period), and reducing 20% of the applied fertilizer amount and splitting the fertilizer doses. The BMPs were evaluated on the basis of local experience and farmer interaction. Results showed that reducing fertilizer amounts by 20% could lead to a reduction of 50% of the number of days exceeding the nitrate concentration limit value (50 mg L) set by the European Water Framework Directive. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Apex simulation: environmental benefits of agroforestry and grass buffers for corn-soybean watersheds

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The Agricultural Policy Environmental Extender (APEX) model is used to simulate the effects of vegetative filter strips on runoff and pollutant loadings from agricultural watersheds. A long-term paired watershed study under corn (Zea mays L-soybean [Glycine max (L.) Merr.] rotation with agroforestr...

Can the watershed non-point phosphorus pollution be interpreted by critical soil properties? A new insight of different soil P states.

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Lin, Chen; Ma, Ronghua; Xiong, Junfeng

2018-07-01

The physicochemical properties of surface soil play a key role in the fate of watershed non-point source pollution. Special emphasis is needed to identify soil properties that are sensitive to both particulate P (PP) pollution and dissolved P (DP) pollution, which is essential for watershed environmental management. The Chaohu Lake basin, a typical eutrophic lake in China, was selected as the study site. The spatial features of the Non-point Source (NPS) PP loads and DP loads were calculated simultaneously based on the integration of sediment delivery distributed model (SEDD) and pollution loads (PLOAD) model. Then several critical physicochemical soil properties, especially various soil P compositions, were innovatively introduced to determine the response of the critical soil properties to NPS P pollution. The findings can be summarized: i) the mean PP load value of the different sub-basins was 5.87 kg, and PP pollution is regarded to be the primary NPS P pollution state, while the DP loads increased rapidly under the rapid urbanization process. ii) iron-bound phosphorus (Fe-P) and aluminum-bound phosphorus (Al-P) are the main components of available P and showed the most sensitive responses to NPS PP pollution, and the correlation coefficients were approximately 0.9. Otherwise, the residual phosphorus (Res-P) was selected as a sensitive soil P state that was significantly negatively correlated with the DP loads. iii) The DP and PP concentrations were represented differently when they were correlated with various soil properties, and the clay proportion was strongly negatively related to the PP loads. Meanwhile, there is a non-linear relationship between the DP loads and the critical soil properties, such as Fe and Total Nitrogen (TN) concentrations. Specifically, a strong inhibitory effect of TN concentration on the DP load was apparent in the Nanfei river (NF) and Paihe (PH) river basins where the R 2 reached 0.67, which contrasts with the relatively poor

GIS Based Distributed Runoff Predictions in Variable Source Area Watersheds Employing the SCS-Curve Number

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Steenhuis, T. S.; Mendoza, G.; Lyon, S. W.; Gerard Marchant, P.; Walter, M. T.; Schneiderman, E.

2003-04-01

Because the traditional Soil Conservation Service Curve Number (SCS-CN) approach continues to be ubiquitously used in GIS-BASED water quality models, new application methods are needed that are consistent with variable source area (VSA) hydrological processes in the landscape. We developed within an integrated GIS modeling environment a distributed approach for applying the traditional SCS-CN equation to watersheds where VSA hydrology is a dominant process. Spatial representation of hydrologic processes is important for watershed planning because restricting potentially polluting activities from runoff source areas is fundamental to controlling non-point source pollution. The methodology presented here uses the traditional SCS-CN method to predict runoff volume and spatial extent of saturated areas and uses a topographic index to distribute runoff source areas through watersheds. The resulting distributed CN-VSA method was incorporated in an existing GWLF water quality model and applied to sub-watersheds of the Delaware basin in the Catskill Mountains region of New York State. We found that the distributed CN-VSA approach provided a physically-based method that gives realistic results for watersheds with VSA hydrology.

Occurrence of THM and NDMA precursors in a watershed: Effect of seasons and anthropogenic pollution.

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Aydin, Egemen; Yaman, Fatma Busra; Ates Genceli, Esra; Topuz, Emel; Erdim, Esra; Gurel, Melike; Ipek, Murat; Pehlivanoglu-Mantas, Elif

2012-06-30

In pristine watersheds, natural organic matter is the main source of disinfection by-product (DBP) precursors. However, the presence of point or non-point pollution sources in watersheds may lead to increased levels of DBP precursors which in turn form DBPs in the drinking water treatment plant upon chlorination or chloramination. In this study, water samples were collected from a lake used to obtain drinking water for Istanbul as well as its tributaries to investigate the presence of the precursors of two disinfection by-products, trihalomethanes (THM) and N-nitrosodimethylamine (NDMA). In addition, the effect of seasons and the possible relationships between these precursors and water quality parameters were evaluated. The concentrations of THM and NDMA precursors measured as total THM formation potential (TTHMFP) and NDMA formation potential (NDMAFP) ranged between 126 and 1523μg/L THM and NDMA, respectively. Such wide ranges imply that some of the tributaries are affected by anthropogenic pollution sources, which is also supported by high DOC, Cl(-) and NH(3) concentrations. No significant correlation was found between the water quality parameters and DBP formation potential, except for a weak correlation between NDMAFP and DOC concentrations. The effect of the sampling location was more pronounced than the seasonal variation due to anthropogenic pollution in some tributaries and no significant correlation was obtained between the seasons and water quality parameters. Copyright © 2012 Elsevier B.V. All rights reserved.

Watershed modeling applications in south Texas

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Pedraza, Diana E.; Ockerman, Darwin J.

2012-01-01

Watershed models can be used to simulate natural and human-altered processes including the flow of water and associated transport of sediment, chemicals, nutrients, and microbial organisms within a watershed. Simulation of these processes is useful for addressing a wide range of water-resource challenges, such as quantifying changes in water availability over time, understanding the effects of development and land-use changes on water resources, quantifying changes in constituent loads and yields over time, and quantifying aquifer recharge temporally and spatially throughout a watershed.

A risk explicit interval linear programming model for uncertainty-based environmental economic optimization in the Lake Fuxian watershed, China.

Science.gov (United States)

Zhang, Xiaoling; Huang, Kai; Zou, Rui; Liu, Yong; Yu, Yajuan

2013-01-01

The conflict of water environment protection and economic development has brought severe water pollution and restricted the sustainable development in the watershed. A risk explicit interval linear programming (REILP) method was used to solve integrated watershed environmental-economic optimization problem. Interval linear programming (ILP) and REILP models for uncertainty-based environmental economic optimization at the watershed scale were developed for the management of Lake Fuxian watershed, China. Scenario analysis was introduced into model solution process to ensure the practicality and operability of optimization schemes. Decision makers' preferences for risk levels can be expressed through inputting different discrete aspiration level values into the REILP model in three periods under two scenarios. Through balancing the optimal system returns and corresponding system risks, decision makers can develop an efficient industrial restructuring scheme based directly on the window of "low risk and high return efficiency" in the trade-off curve. The representative schemes at the turning points of two scenarios were interpreted and compared to identify a preferable planning alternative, which has the relatively low risks and nearly maximum benefits. This study provides new insights and proposes a tool, which was REILP, for decision makers to develop an effectively environmental economic optimization scheme in integrated watershed management.

A Risk Explicit Interval Linear Programming Model for Uncertainty-Based Environmental Economic Optimization in the Lake Fuxian Watershed, China

Directory of Open Access Journals (Sweden)

Xiaoling Zhang

2013-01-01

Full Text Available The conflict of water environment protection and economic development has brought severe water pollution and restricted the sustainable development in the watershed. A risk explicit interval linear programming (REILP method was used to solve integrated watershed environmental-economic optimization problem. Interval linear programming (ILP and REILP models for uncertainty-based environmental economic optimization at the watershed scale were developed for the management of Lake Fuxian watershed, China. Scenario analysis was introduced into model solution process to ensure the practicality and operability of optimization schemes. Decision makers’ preferences for risk levels can be expressed through inputting different discrete aspiration level values into the REILP model in three periods under two scenarios. Through balancing the optimal system returns and corresponding system risks, decision makers can develop an efficient industrial restructuring scheme based directly on the window of “low risk and high return efficiency” in the trade-off curve. The representative schemes at the turning points of two scenarios were interpreted and compared to identify a preferable planning alternative, which has the relatively low risks and nearly maximum benefits. This study provides new insights and proposes a tool, which was REILP, for decision makers to develop an effectively environmental economic optimization scheme in integrated watershed management.

Evaluating the effectiveness of management practices on hydrology and water quality at watershed scale with a rainfall-runoff model.

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Liu, Yaoze; Bralts, Vincent F; Engel, Bernard A

2015-04-01

The adverse influence of urban development on hydrology and water quality can be reduced by applying best management practices (BMPs) and low impact development (LID) practices. This study applied green roof, rain barrel/cistern, bioretention system, porous pavement, permeable patio, grass strip, grassed swale, wetland channel, retention pond, detention basin, and wetland basin, on Crooked Creek watershed. The model was calibrated and validated for annual runoff volume. A framework for simulating BMPs and LID practices at watershed scales was created, and the impacts of BMPs and LID practices on water quantity and water quality were evaluated with the Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model for 16 scenarios. The various levels and combinations of BMPs/LID practices reduced runoff volume by 0 to 26.47%, Total Nitrogen (TN) by 0.30 to 34.20%, Total Phosphorus (TP) by 0.27 to 47.41%, Total Suspended Solids (TSS) by 0.33 to 53.59%, Lead (Pb) by 0.30 to 60.98%, Biochemical Oxygen Demand (BOD) by 0 to 26.70%, and Chemical Oxygen Demand (COD) by 0 to 27.52%. The implementation of grass strips in 25% of the watershed where this practice could be applied was the most cost-efficient scenario, with cost per unit reduction of $1m3/yr for runoff, while cost for reductions of two pollutants of concern was $445 kg/yr for Total Nitrogen (TN) and $4871 kg/yr for Total Phosphorous (TP). The scenario with very high levels of BMP and LID practice adoption (scenario 15) reduced runoff volume and pollutant loads from 26.47% to 60.98%, and provided the greatest reduction in runoff volume and pollutant loads among all scenarios. However, this scenario was not as cost-efficient as most other scenarios. The L-THIA-LID 2.1 model is a valid tool that can be applied to various locations to help identify cost effective BMP/LID practice plans at watershed scales. Copyright © 2014 Elsevier B.V. All rights reserved.

Watershed monitoring and modelling and USA regulatory compliance.

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Turner, B G; Boner, M C

2004-01-01

The aim of the Columbus program was to implement a comprehensive watershed monitoring-network including water chemistry, aquatic biology and alternative sensors to establish water environment health and methods for determining future restoration progress and early warning for protection of drinking water supplies. The program was implemented to comply with USA regulatory requirements including Total Maximum Daily Load (TMDL) rules of the Clean Water Act (CWA) and Source Water Assessment and Protection (SWAP) rules under the Safe Drinking Water Act (SDWA). The USEPA Office of Research and Development and the Water Environment Research Foundation provided quality assurance oversight. The results obtained demonstrated that significant wet weather data is necessary to establish relationships between land use, water chemistry, aquatic biology and sensor data. These measurements and relationships formed the basis for calibrating the US EPA BASINS Model, prioritizing watershed health and determination of compliance with water quality standards. Conclusions specify priorities of cost-effective drainage system controls that attenuate stormwater flows and capture flushed pollutants. A network of permanent long-term real-time monitoring using combination of continuous sensor measurements, water column sampling and aquatic biology surveys and a regional organization is prescribed to protect drinking water supplies and measure progress towards water quality targets.

Application of the ReNuMa model in the Sha He river watershed: tools for watershed environmental management.

Science.gov (United States)

Sha, Jian; Liu, Min; Wang, Dong; Swaney, Dennis P; Wang, Yuqiu

2013-07-30

Models and related analytical methods are critical tools for use in modern watershed management. A modeling approach for quantifying the source apportionment of dissolved nitrogen (DN) and associated tools for examining the sensitivity and uncertainty of the model estimates were assessed for the Sha He River (SHR) watershed in China. The Regional Nutrient Management model (ReNuMa) was used to infer the primary sources of DN in the SHR watershed. This model is based on the Generalized Watershed Loading Functions (GWLF) and the Net Anthropogenic Nutrient Input (NANI) framework, modified to improve the characterization of subsurface hydrology and septic system loads. Hydrochemical processes of the SHR watershed, including streamflow, DN load fluxes, and corresponding DN concentration responses, were simulated following calibrations against observations of streamflow and DN fluxes. Uncertainty analyses were conducted with a Monte Carlo analysis to vary model parameters for assessing the associated variations in model outputs. The model performed accurately at the watershed scale and provided estimates of monthly streamflows and nutrient loads as well as DN source apportionments. The simulations identified the dominant contribution of agricultural land use and significant monthly variations. These results provide valuable support for science-based watershed management decisions and indicate the utility of ReNuMa for such applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Impacts of manure application on SWAT model outputs in the Xiangxi River watershed

Science.gov (United States)

Liu, Ruimin; Wang, Qingrui; Xu, Fei; Men, Cong; Guo, Lijia

2017-12-01

SWAT (Soil and Water Assessment Tool) model has been widely used to simulate agricultural non-point source (ANPS) pollution; however, the impacts of livestock manure application on SWAT model outputs have not been well studied. The objective of this study was to investigate the environmental effects of livestock manure application based on the SWAT model in the Xiangxi River watershed, which is one of the largest tributaries of the Three Gorges Reservoir in China. Three newly-built manure databases (NB) were created and applied to different subbasins based on the actual livestock manure discharging amount. The calibration and validation values of SWAT model outputs obtained from the NB manure application and the original mixed (OM) manure were compared. The study results are as follows: (1) The livestock industry of Xingshan County developed quickly between 2005 and 2015. The downstream of the Xiangxi River (Huangliang, Shuiyuesi and Xiakou) had the largest livestock amount, and largely accounted for manure, total nitrogen (TN) and total phosphorus (TP) production (>50%). (2) The NB manure application resulted in less phosphorus pollution (1686.35 kg for ORGP and 31.70 kg for MINP) than the OM manure application. Compared with the upstream, the downstream was influenced more by the manure application. (3) The SWAT results obtained from the NB manure had a better calibration and validation values than those from the OM manure. For ORGP, R2 and NSE values were 0.77 and 0.65 for the NB manure calibration; and the same values for the OM manure were 0.72 and 0.61, respectively. For MINP, R2 values were 0.65 and 0.62 for the NB manure and the OM manure, and the NSE values were 0.60 and 0.58, respectively. The results indicated that the built-in fertilizer database in SWAT has its limitation because it is set up for the simulation in the USA. Thus, when livestock manure is considered in a SWAT simulation, a newly built fertilizer database needs to be set up to represent

Watershed System Model: The Essentials to Model Complex Human-Nature System at the River Basin Scale

Science.gov (United States)

Li, Xin; Cheng, Guodong; Lin, Hui; Cai, Ximing; Fang, Miao; Ge, Yingchun; Hu, Xiaoli; Chen, Min; Li, Weiyue

2018-03-01

Watershed system models are urgently needed to understand complex watershed systems and to support integrated river basin management. Early watershed modeling efforts focused on the representation of hydrologic processes, while the next-generation watershed models should represent the coevolution of the water-land-air-plant-human nexus in a watershed and provide capability of decision-making support. We propose a new modeling framework and discuss the know-how approach to incorporate emerging knowledge into integrated models through data exchange interfaces. We argue that the modeling environment is a useful tool to enable effective model integration, as well as create domain-specific models of river basin systems. The grand challenges in developing next-generation watershed system models include but are not limited to providing an overarching framework for linking natural and social sciences, building a scientifically based decision support system, quantifying and controlling uncertainties, and taking advantage of new technologies and new findings in the various disciplines of watershed science. The eventual goal is to build transdisciplinary, scientifically sound, and scale-explicit watershed system models that are to be codesigned by multidisciplinary communities.

[Nitrogen non-point source pollution identification based on ArcSWAT in Changle River].

Science.gov (United States)

Deng, Ou-Ping; Sun, Si-Yang; Lü, Jun

2013-04-01

The ArcSWAT (Soil and Water Assessment Tool) model was adopted for Non-point source (NPS) nitrogen pollution modeling and nitrogen source apportionment for the Changle River watershed, a typical agricultural watershed in Southeast China. Water quality and hydrological parameters were monitored, and the watershed natural conditions (including soil, climate, land use, etc) and pollution sources information were also investigated and collected for SWAT database. The ArcSWAT model was established in the Changle River after the calibrating and validating procedures of the model parameters. Based on the validated SWAT model, the contributions of different nitrogen sources to river TN loading were quantified, and spatial-temporal distributions of NPS nitrogen export to rivers were addressed. The results showed that in the Changle River watershed, Nitrogen fertilizer, nitrogen air deposition and nitrogen soil pool were the prominent pollution sources, which contributed 35%, 32% and 25% to the river TN loading, respectively. There were spatial-temporal variations in the critical sources for NPS TN export to the river. Natural sources, such as soil nitrogen pool and atmospheric nitrogen deposition, should be targeted as the critical sources for river TN pollution during the rainy seasons. Chemical nitrogen fertilizer application should be targeted as the critical sources for river TN pollution during the crop growing season. Chemical nitrogen fertilizer application, soil nitrogen pool and atmospheric nitrogen deposition were the main sources for TN exported from the garden plot, forest and residential land, respectively. However, they were the main sources for TN exported both from the upland and paddy field. These results revealed that NPS pollution controlling rules should focus on the spatio-temporal distribution of NPS pollution sources.

Analysis on the relationship between economic development and water environment pollution in Shandong province

Science.gov (United States)

Liu, Yi; Zhang, Zhengxian

2018-02-01

With the continuous development of the economy of the Shandong Province watershed, a large number of pollutant emission, resulting in water quality of the basin has undergone significant changes. To study the Shandong Province watershed economic development and the relationship between the discharge of pollutants, in this paper, the relationship between economic growth and pollutant emissions in the Shandong Province watershed was established by Shandong Province watershed in 2002-2015 per capita GDP and wastewater, COD, ammonia nitrogen(AN) pollutant emissions. The data were analyzed by software such as SPSS, and the cubic equation model between various pollutants and economic indexes was fitted. To further make the relationship between pollutants and economic development map to study the conventional pollutant emissions and economic development trends. It is found that only the relationship between industrial wastewater discharge and per capita GDP is most coordinated, that is, industrial wastewater emissions with the continuous development of the basin economy, showing a tendency to rise first and then fall. Finally, ultimately based on the results of the study of the water environment and economic development proposals were proposed.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Estimation of contribution ratios of pollutant sources to a specific section based on an enhanced water quality model.

Science.gov (United States)

Cao, Bibo; Li, Chuan; Liu, Yan; Zhao, Yue; Sha, Jian; Wang, Yuqiu

2015-05-01

Because water quality monitoring sections or sites could reflect the water quality status of rivers, surface water quality management based on water quality monitoring sections or sites would be effective. For the purpose of improving water quality of rivers, quantifying the contribution ratios of pollutant resources to a specific section is necessary. Because physical and chemical processes of nutrient pollutants are complex in water bodies, it is difficult to quantitatively compute the contribution ratios. However, water quality models have proved to be effective tools to estimate surface water quality. In this project, an enhanced QUAL2Kw model with an added module was applied to the Xin'anjiang Watershed, to obtain water quality information along the river and to assess the contribution ratios of each pollutant source to a certain section (the Jiekou state-controlled section). Model validation indicated that the results were reliable. Then, contribution ratios were analyzed through the added module. Results show that among the pollutant sources, the Lianjiang tributary contributes the largest part of total nitrogen (50.43%), total phosphorus (45.60%), ammonia nitrogen (32.90%), nitrate (nitrite + nitrate) nitrogen (47.73%), and organic nitrogen (37.87%). Furthermore, contribution ratios in different reaches varied along the river. Compared with pollutant loads ratios of different sources in the watershed, an analysis of contribution ratios of pollutant sources for each specific section, which takes the localized chemical and physical processes into consideration, was more suitable for local-regional water quality management. In summary, this method of analyzing the contribution ratios of pollutant sources to a specific section based on the QUAL2Kw model was found to support the improvement of the local environment.

Groundwater flow modelling in the upper Anga'a river watershed ...

African Journals Online (AJOL)

ISHIOMA

The Anga'a River watershed is located within the Yaounde IV district, South-east of Yaounde City,. Cameroon. ... B: A nga'a drainage basin in the City of Yaoundé ... show the potential danger of groundwater pollution by ... The city of Yaounde is located about 250 km from the Atlantic coast .... forest zone of south Cameroon.

Linking current river pollution to historical pesticide use: Insights for territorial management?

Science.gov (United States)

Della Rossa, Pauline; Jannoyer, Magalie; Mottes, Charles; Plet, Joanne; Bazizi, Abderazak; Arnaud, Luc; Jestin, Alexandra; Woignier, Thierry; Gaude, Jean-Marie; Cattan, Philippe

2017-01-01

Persistent organic pollutants like organochlorine pesticides continue to contaminate large areas worldwide raising questions concerning their management. We designed and tested a method to link soil and water pollution in the watershed of the Galion River in Martinique. We first estimated the risk of soil contamination by chlordecone by referring to past use of land for banana cultivation and took 27 soil samples. We then sampled surface waters at 39 points and groundwater at 16 points. We tested three hypotheses linked to the source of chlordecone pollution at the watershed scale: (i) soils close to the river, (ii) soils close to the sampling point, (iii) throughout the sub-watershed generated at the sampling point. Graphical and statistical analysis showed that contamination of the river increased when it passed through an area with contaminated plots and decreased when it passed through area not contaminated by chlordecone. Modeling showed that the entire surface area of the watershed contributed to river pollution, suggesting that the river was mainly being contaminated by the aquifers and groundwater flows. Our method proved to be a reliable way to identify areas polluted by chlordecone at the watershed scale and should help stakeholders focus their management actions on both hot spots and the whole watershed. Copyright © 2016 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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

Model Calibration in Watershed Hydrology

Science.gov (United States)

Yilmaz, Koray K.; Vrugt, Jasper A.; Gupta, Hoshin V.; Sorooshian, Soroosh

2009-01-01

Hydrologic models use relatively simple mathematical equations to conceptualize and aggregate the complex, spatially distributed, and highly interrelated water, energy, and vegetation processes in a watershed. A consequence of process aggregation is that the model parameters often do not represent directly measurable entities and must, therefore, be estimated using measurements of the system inputs and outputs. During this process, known as model calibration, the parameters are adjusted so that the behavior of the model approximates, as closely and consistently as possible, the observed response of the hydrologic system over some historical period of time. This Chapter reviews the current state-of-the-art of model calibration in watershed hydrology with special emphasis on our own contributions in the last few decades. We discuss the historical background that has led to current perspectives, and review different approaches for manual and automatic single- and multi-objective parameter estimation. In particular, we highlight the recent developments in the calibration of distributed hydrologic models using parameter dimensionality reduction sampling, parameter regularization and parallel computing.

Assessing the effects of regional payment for watershed services program on water quality using an intervention analysis model.

Science.gov (United States)

Lu, Yan; He, Tian

2014-09-15

Much attention has been recently paid to ex-post assessments of socioeconomic and environmental benefits of payment for ecosystem services (PES) programs on poverty reduction, water quality, and forest protection. To evaluate the effects of a regional PES program on water quality, we selected chemical oxygen demand (COD) and ammonia-nitrogen (NH3-N) as indicators of water quality. Statistical methods and an intervention analysis model were employed to assess whether the PES program produced substantial changes in water quality at 10 water-quality sampling stations in the Shaying River watershed, China during 2006-2011. Statistical results from paired-sample t-tests and box plots of COD and NH3-N concentrations at the 10 stations showed that the PES program has played a positive role in improving water quality and reducing trans-boundary water pollution in the Shaying River watershed. Using the intervention analysis model, we quantitatively evaluated the effects of the intervention policy, i.e., the watershed PES program, on water quality at the 10 stations. The results suggest that this method could be used to assess the environmental benefits of watershed or water-related PES programs, such as improvements in water quality, seasonal flow regulation, erosion and sedimentation, and aquatic habitat. Copyright © 2014 Elsevier B.V. All rights reserved.

A Web-Based Tool to Estimate Pollutant Loading Using LOADEST

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Youn Shik Park

2015-09-01

Full Text Available Collecting and analyzing water quality samples is costly and typically requires significant effort compared to streamflow data, thus water quality data are typically collected at a low frequency. Regression models, identifying a relationship between streamflow and water quality data, are often used to estimate pollutant loads. A web-based tool using LOAD ESTimator (LOADEST as a core engine with four modules was developed to provide user-friendly interfaces and input data collection via web access. The first module requests and receives streamflow and water quality data from the U.S. Geological Survey. The second module retrieves watershed area for computation of pollutant loads per unit area. The third module examines potential error of input datasets for LOADEST runs, and the last module computes estimated and allowable annual average pollutant loads and provides tabular and graphical LOADEST outputs. The web-based tool was applied to two watersheds in this study, one agriculturally-dominated and one urban-dominated. It was found that annual sediment load at the urban-dominant watershed exceeded the target load; therefore, the web-based tool identified correctly the watershed requiring best management practices to reduce pollutant loads.

Thermal pollution impacts on rivers and power supply in the Mississippi River watershed

Science.gov (United States)

Miara, Ariel; Vörösmarty, Charles J.; Macknick, Jordan E.; Tidwell, Vincent C.; Fekete, Balazs; Corsi, Fabio; Newmark, Robin

2018-03-01

Thermal pollution from power plants degrades riverine ecosystems with ramifications beyond the natural environment as it affects power supply. The transport of thermal effluents along river reaches may lead to plant-to-plant interferences by elevating condenser inlet temperatures at downstream locations, which lower thermal efficiencies and trigger regulatory-forced power curtailments. We evaluate thermal pollution impacts on rivers and power supply across 128 plants with once-through cooling technologies in the Mississippi River watershed. By leveraging river network topologies with higher resolutions (0.05°) than previous studies, we reveal the need to address the issue in a more spatially resolved manner, capable of uncovering diverse impacts across individual plants, river reaches and sub-basins. Results show that the use of coarse river network resolutions may lead to substantial overestimations in magnitude and length of impaired river reaches. Overall, there is a modest limitation on power production due to thermal pollution, given existing infrastructure, regulatory and climate conditions. However, tradeoffs between thermal pollution and electricity generation show important implications for the role of alternative cooling technologies and environmental regulation under current and future climates. Recirculating cooling technologies may nearly eliminate thermal pollution and improve power system reliability under stressed climate-water conditions. Regulatory limits also reduce thermal pollution, but at the expense of significant reductions in electricity generation capacity. However, results show several instances when power production capacity rises at individual plants when regulatory limits reduce upstream thermal pollution. These dynamics across energy-water systems highlight the need for high-resolution simulations and the value of coherent planning and optimization across infrastructure with mutual dependencies on natural resources to overcome

Compilation of watershed models for tributaries to the Great Lakes, United States, as of 2010, and identification of watersheds for future modeling for the Great Lakes Restoration Initiative

Science.gov (United States)

Coon, William F.; Murphy, Elizabeth A.; Soong, David T.; Sharpe, Jennifer B.

2011-01-01

As part of the Great Lakes Restoration Initiative (GLRI) during 2009–10, the U.S. Geological Survey (USGS) compiled a list of existing watershed models that had been created for tributaries within the United States that drain to the Great Lakes. Established Federal programs that are overseen by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Army Corps of Engineers (USACE) are responsible for most of the existing watershed models for specific tributaries. The NOAA Great Lakes Environmental Research Laboratory (GLERL) uses the Large Basin Runoff Model to provide data for the management of water levels in the Great Lakes by estimating United States and Canadian inflows to the Great Lakes from 121 large watersheds. GLERL also simulates streamflows in 34 U.S. watersheds by a grid-based model, the Distributed Large Basin Runoff Model. The NOAA National Weather Service uses the Sacramento Soil Moisture Accounting model to predict flows at river forecast sites. The USACE created or funded the creation of models for at least 30 tributaries to the Great Lakes to better understand sediment erosion, transport, and aggradation processes that affect Federal navigation channels and harbors. Many of the USACE hydrologic models have been coupled with hydrodynamic and sediment-transport models that simulate the processes in the stream and harbor near the mouth of the modeled tributary. Some models either have been applied or have the capability of being applied across the entire Great Lakes Basin; they are (1) the SPAtially Referenced Regressions On Watershed attributes (SPARROW) model, which was developed by the USGS; (2) the High Impact Targeting (HIT) and Digital Watershed models, which were developed by the Institute of Water Research at Michigan State University; (3) the Long-Term Hydrologic Impact Assessment (L–THIA) model, which was developed by researchers at Purdue University; and (4) the Water Erosion Prediction Project (WEPP) model, which was

A simulation-based interval two-stage stochastic model for agricultural nonpoint source pollution control through land retirement

International Nuclear Information System (INIS)

Luo, B.; Li, J.B.; Huang, G.H.; Li, H.L.

2006-01-01

This study presents a simulation-based interval two-stage stochastic programming (SITSP) model for agricultural nonpoint source (NPS) pollution control through land retirement under uncertain conditions. The modeling framework was established by the development of an interval two-stage stochastic program, with its random parameters being provided by the statistical analysis of the simulation outcomes of a distributed water quality approach. The developed model can deal with the tradeoff between agricultural revenue and 'off-site' water quality concern under random effluent discharge for a land retirement scheme through minimizing the expected value of long-term total economic and environmental cost. In addition, the uncertainties presented as interval numbers in the agriculture-water system can be effectively quantified with the interval programming. By subdividing the whole agricultural watershed into different zones, the most pollution-related sensitive cropland can be identified and an optimal land retirement scheme can be obtained through the modeling approach. The developed method was applied to the Swift Current Creek watershed in Canada for soil erosion control through land retirement. The Hydrological Simulation Program-FORTRAN (HSPF) was used to simulate the sediment information for this case study. Obtained results indicate that the total economic and environmental cost of the entire agriculture-water system can be limited within an interval value for the optimal land retirement schemes. Meanwhile, a best and worst land retirement scheme was obtained for the study watershed under various uncertainties

Stochastic Watershed Models for Risk Based Decision Making

Science.gov (United States)

Vogel, R. M.

2017-12-01

Over half a century ago, the Harvard Water Program introduced the field of operational or synthetic hydrology providing stochastic streamflow models (SSMs), which could generate ensembles of synthetic streamflow traces useful for hydrologic risk management. The application of SSMs, based on streamflow observations alone, revolutionized water resources planning activities, yet has fallen out of favor due, in part, to their inability to account for the now nearly ubiquitous anthropogenic influences on streamflow. This commentary advances the modern equivalent of SSMs, termed `stochastic watershed models' (SWMs) useful as input to nearly all modern risk based water resource decision making approaches. SWMs are deterministic watershed models implemented using stochastic meteorological series, model parameters and model errors, to generate ensembles of streamflow traces that represent the variability in possible future streamflows. SWMs combine deterministic watershed models, which are ideally suited to accounting for anthropogenic influences, with recent developments in uncertainty analysis and principles of stochastic simulation

Application of Large-Scale, Multi-Resolution Watershed Modeling Framework Using the Hydrologic and Water Quality System (HAWQS

Directory of Open Access Journals (Sweden)

Haw Yen

2016-04-01

Full Text Available In recent years, large-scale watershed modeling has been implemented broadly in the field of water resources planning and management. Complex hydrological, sediment, and nutrient processes can be simulated by sophisticated watershed simulation models for important issues such as water resources allocation, sediment transport, and pollution control. Among commonly adopted models, the Soil and Water Assessment Tool (SWAT has been demonstrated to provide superior performance with a large amount of referencing databases. However, it is cumbersome to perform tedious initialization steps such as preparing inputs and developing a model with each changing targeted study area. In this study, the Hydrologic and Water Quality System (HAWQS is introduced to serve as a national-scale Decision Support System (DSS to conduct challenging watershed modeling tasks. HAWQS is a web-based DSS developed and maintained by Texas A & M University, and supported by the U.S. Environmental Protection Agency. Three different spatial resolutions of Hydrologic Unit Code (HUC8, HUC10, and HUC12 and three temporal scales (time steps in daily/monthly/annual are available as alternatives for general users. In addition, users can specify preferred values of model parameters instead of using the pre-defined sets. With the aid of HAWQS, users can generate a preliminarily calibrated SWAT project within a few minutes by only providing the ending HUC number of the targeted watershed and the simulation period. In the case study, HAWQS was implemented on the Illinois River Basin, USA, with graphical demonstrations and associated analytical results. Scientists and/or decision-makers can take advantage of the HAWQS framework while conducting relevant topics or policies in the future.

Modeling the impact of watershed management policies on marine ecosystem services with application to Hood Canal, WA, USA

Science.gov (United States)

Sutherland, D. A.; Kim, C.; Marsik, M.; Spiridonov, G.; Toft, J.; Ruckelshaus, M.; Guerry, A.; Plummer, M.

2011-12-01

Humans obtain numerous benefits from marine ecosystems, including fish to eat; mitigation of storm damage; nutrient and water cycling and primary production; and cultural, aesthetic and recreational values. However, managing these benefits, or ecosystem services, in the marine world relies on an integrated approach that accounts for both marine and watershed activities. Here we present the results of a set of simple, physically-based, and spatially-explicit models that quantify the effects of terrestrial activities on marine ecosystem services. Specifically, we model the circulation and water quality of Hood Canal, WA, USA, a fjord system in Puget Sound where multiple human uses of the nearshore ecosystem (e.g., shellfish aquaculture, recreational Dungeness crab and shellfish harvest) can be compromised when water quality is poor (e.g., hypoxia, excessive non-point source pollution). Linked to the estuarine water quality model is a terrestrial hydrology model that simulates streamflow and nutrient loading, so land cover and climate changes in watersheds can be reflected in the marine environment. In addition, a shellfish aquaculture model is linked to the water quality model to test the sensitivity of the ecosystem service and its value to both terrestrial and marine activities. The modeling framework is general and will be publicly available, allowing easy comparisons of watershed impacts on marine ecosystem services across multiple scales and regions.

Looking for a relevant potential evapotranspiration model at the watershed scale

Science.gov (United States)

Oudin, L.; Hervieu, F.; Michel, C.; Perrin, C.; Anctil, F.; Andréassian, V.

2003-04-01

In this paper, we try to identify the most relevant approach to calculate Potential Evapotranspiration (PET) for use in a daily watershed model, to try to bring an answer to the following question: "how can we use commonly available atmospheric parameters to represent the evaporative demand at the catchment scale?". Hydrologists generally see the Penman model as the ideal model regarding to its good adequacy with lysimeter measurements and its physically-based formulation. However, in real-world engineering situations, where meteorological stations are scarce, hydrologists are often constrained to use other PET formulae with less data requirements or/and long-term average of PET values (the rationale being that PET is an inherently conservative variable). We chose to test 28 commonly used PET models coupled with 4 different daily watershed models. For each test, we compare both PET input options: actual data and long-term average data. The comparison is made in terms of streamflow simulation efficiency, over a large sample of 308 watersheds. The watersheds are located in France, Australia and the United States of America and represent varied climates. Strikingly, we find no systematic improvements of the watershed model efficiencies when using actual PET series instead of long-term averages. This suggests either that watershed models may not conveniently use the climatic information contained in PET values or that formulae are only awkward indicators of the real PET which watershed models need.

A CN-Based Ensembled Hydrological Model for Enhanced Watershed Runoff Prediction

Directory of Open Access Journals (Sweden)

Muhammad Ajmal

2016-01-01

Full Text Available A major structural inconsistency of the traditional curve number (CN model is its dependence on an unstable fixed initial abstraction, which normally results in sudden jumps in runoff estimation. Likewise, the lack of pre-storm soil moisture accounting (PSMA procedure is another inherent limitation of the model. To circumvent those problems, we used a variable initial abstraction after ensembling the traditional CN model and a French four-parameter (GR4J model to better quantify direct runoff from ungauged watersheds. To mimic the natural rainfall-runoff transformation at the watershed scale, our new parameterization designates intrinsic parameters and uses a simple structure. It exhibited more accurate and consistent results than earlier methods in evaluating data from 39 forest-dominated watersheds, both for small and large watersheds. In addition, based on different performance evaluation indicators, the runoff reproduction results show that the proposed model produced more consistent results for dry, normal, and wet watershed conditions than the other models used in this study.

Spatially-Distributed Cost-Effectiveness Analysis Framework to Control Phosphorus from Agricultural Diffuse Pollution.

Directory of Open Access Journals (Sweden)

Runzhe Geng

Full Text Available Best management practices (BMPs for agricultural diffuse pollution control are implemented at the field or small-watershed scale. However, the benefits of BMP implementation on receiving water quality at multiple spatial is an ongoing challenge. In this paper, we introduce an integrated approach that combines risk assessment (i.e., Phosphorus (P index, model simulation techniques (Hydrological Simulation Program-FORTRAN, and a BMP placement tool at various scales to identify the optimal location for implementing multiple BMPs and estimate BMP effectiveness after implementation. A statistically significant decrease in nutrient discharge from watersheds is proposed to evaluate the effectiveness of BMPs, strategically targeted within watersheds. Specifically, we estimate two types of cost-effectiveness curves (total pollution reduction and proportion of watersheds improved for four allocation approaches. Selection of a ''best approach" depends on the relative importance of the two types of effectiveness, which involves a value judgment based on the random/aggregated degree of BMP distribution among and within sub-watersheds. A statistical optimization framework is developed and evaluated in Chaohe River Watershed located in the northern mountain area of Beijing. Results show that BMP implementation significantly (p >0.001 decrease P loss from the watershed. Remedial strategies where BMPs were targeted to areas of high risk of P loss, deceased P loads compared with strategies where BMPs were randomly located across watersheds. Sensitivity analysis indicated that aggregated BMP placement in particular watershed is the most cost-effective scenario to decrease P loss. The optimization approach outlined in this paper is a spatially hierarchical method for targeting nonpoint source controls across a range of scales from field to farm, to watersheds, to regions. Further, model estimates showed targeting at multiple scales is necessary to optimize program

Modeling urban growth by the use of a multiobjective optimization approach: environmental and economic issues for the Yangtze watershed, China.

Science.gov (United States)

Zhang, Wenting; Wang, Haijun; Han, Fengxiang; Gao, Juan; Nguyen, Thuminh; Chen, Yarong; Huang, Bo; Zhan, F Benjamin; Zhou, Lequn; Hong, Song

2014-11-01

Urban growth is an unavoidable process caused by economic development and population growth. Traditional urban growth models represent the future urban growth pattern by repeating the historical urban growth regulations, which can lead to a lot of environmental problems. The Yangtze watershed is the largest and the most prosperous economic area in China, and it has been suffering from rapid urban growth from the 1970s. With the built-up area increasing from 23,238 to 31,054 km(2) during the period from 1980 to 2005, the watershed has suffered from serious nonpoint source (NPS) pollution problems, which have been mainly caused by the rapid urban growth. To protect the environment and at the same time maintain the economic development, a multiobjective optimization (MOP) is proposed to tradeoff the multiple objectives during the urban growth process of the Yangtze watershed. In particular, the four objectives of minimization of NPS pollution, maximization of GDP value, minimization of the spatial incompatibility between the land uses, and minimization of the cost of land-use change are considered by the MOP approach. Conventionally, a genetic algorithm (GA) is employed to search the Pareto solution set. In our MOP approach, a two-dimensional GA, rather than the traditional one-dimensional GA, is employed to assist with the search for the spatial optimization solution, where the land-use cells in the two-dimensional space act as genes in the GA. Furthermore, to confirm the superiority of the MOP approach over the traditional prediction approaches, a widely used urban growth prediction model, cellular automata (CA), is also carried out to allow a comparison with the Pareto solution of MOP. The results indicate that the MOP approach can make a tradeoff between the multiple objectives and can achieve an optimal urban growth pattern for Yangtze watershed, while the CA prediction model just represents the historical urban growth pattern as the future growth pattern

Applying Spatially Distributed Rainfall to a Hydrological Model in a Tropical Watershed, Manoa Watershed, in Hawaii

Science.gov (United States)

Huang, Y. F.; Tsang, Y. P.

2017-12-01

Rainfall in Hawaii is characterized with high spatial and temporal variability. In the south side of Oahu, the Manoa watershed, with an area of 11 km2, has the annual maximum rainfall of 3900mm and the minimum rainfall of 1000 mm. Despite this high spatial heterogeneity, the rain gage network seems insufficiently capture this pattern. When simulating stream flow and predicting floods with hydrological models in Hawaii, the model performance is often unsatisfactory because of inadequate representation of rainfall data. Longman et al. (in prep.) have developed the spatially distributed daily rainfall across the Hawaiian Islands by applying ordinary kriging, yet these data have not been applied to hydrological models. In this study, we used the Soil and Water Assessment Tool (SWAT) model to assess the streamflow simulation by applying spatially-distributed rainfall in the Manoa watershed. We first used point daily-rainfall at Lyon Arboretum from National Center of Environmental Information (NCEI) as the uniform rainfall input. Secondly, we summarized sub-watershed mean rainfall from the daily spatial-statistical rainfall. Both rainfall data are available from 1999 to 2014. The SWAT was set up for five-year warm-up, nine-year calibration, and two-year validation. The model parameters were calibrated and validated with four U.S. Geological Survey stream gages. We compared the calibrated watershed parameters, characteristics, and assess the streamflow hydrographs from these two rainfall inputs. The differences and improvement of using spatially distributed rainfall input in SWAT were discussed. In addition to improving the model by the representation of rainfall, this study helped us having a better understanding of the watershed hydrological response in Hawaii.

The hydrological calibration and validation of a complexly-linked watershed reservoir model for the Occoquan watershed, Virginia

Science.gov (United States)

Xu, Zhongyan; Godrej, Adil N.; Grizzard, Thomas J.

2007-10-01

SummaryRunoff models such as HSPF and reservoir models such as CE-QUAL-W2 are used to model water quality in watersheds. Most often, the models are independently calibrated to observed data. While this approach can achieve good calibration, it does not replicate the physically-linked nature of the system. When models are linked by using the model output from an upstream model as input to a downstream model, the physical reality of a continuous watershed, where the overland and waterbody portions are parts of the whole, is better represented. There are some additional challenges in the calibration of such linked models, because the aim is to simulate the entire system as a whole, rather than piecemeal. When public entities are charged with model development, one of the driving forces is to use public-domain models. This paper describes the use of two such models, HSPF and CE-QUAL-W2, in the linked modeling of the Occoquan watershed located in northern Virginia, USA. The description of the process is provided, and results from the hydrological calibration and validation are shown. The Occoquan model consists of six HSPF and two CE-QUAL-W2 models, linked in a complex way, to simulate two major reservoirs and the associated drainage areas. The overall linked model was calibrated for a three-year period and validated for a two-year period. The results show that a successful calibration can be achieved using the linked approach, with moderate additional effort. Overall flow balances based on the three-year calibration period at four stream stations showed agreement ranging from -3.95% to +3.21%. Flow balances for the two reservoirs, compared via the daily water surface elevations, also showed good agreement ( R2 values of 0.937 for Lake Manassas and 0.926 for Occoquan Reservoir), when missing (un-monitored) flows were included. Validation of the models ranged from poor to fair for the watershed models and excellent for the waterbody models, thus indicating that the

Evaluating spatial interaction of soil property with non-point source pollution at watershed scale: The phosphorus indicator in Northeast China

Energy Technology Data Exchange (ETDEWEB)

Ouyang, Wei, E-mail: wei@itc.nl; Huang, Haobo; Hao, Fanghua; Shan, Yushu; Guo, Bobo

2012-08-15

To better understand the spatial dynamics of non-point source (NPS) phosphorus loading with soil property at watershed scale, integrated modeling and soil chemistry is crucial to ensure that the indicator is functioning properly and expressing the spatial interaction at two depths. Developments in distributed modeling have greatly enriched the availability of geospatial data analysis and assess the NPS pollution loading response to soil property over larger area. The 1.5 km-grid soil sampling at two depths was analyzed with eight parameters, which provided detailed spatial and vertical soil data under four main types of landuses. The impacts of landuse conversion and agricultural practice on soil property were firstly identified. Except for the slightly bigger total of potassium (TK) and cadmium (Cr), the other six parameters had larger content in 20-40 cm surface than the top 20 cm surface. The Soil and Water Assessment Tool was employed to simulate the loading of NPS phosphorus. Overlaying with the landuse distribution, it was found that the NPS phosphorus mainly comes from the subbasins dominated with upland and paddy rice. The linear correlations of eight soil parameters at two depths with NPS phosphorus loading in the subbasins of upland and paddy rice were compared, respectively. The correlations of available phosphorus (AP), total phosphorus (TP), total nitrogen (TN) and TK varied in two depths, and also can assess the loading. The soil with lower soil organic carbon (SOC) presented a significant higher risk for NPS phosphorus loading, especially in agricultural area. The Principal Component Analysis showed that the TP and zinc (Zn) in top soil and copper (Cu) and Cr in subsurface can work as indicators. The analysis suggested that the application of soil property indicators is useful for assessing NPS phosphorus loss, which is promising for water safety in agricultural area. -- Highlights: Black-Right-Pointing-Pointer Spatial dynamics of NPS phosphorus

Evaluating spatial interaction of soil property with non‐point source pollution at watershed scale: The phosphorus indicator in Northeast China

International Nuclear Information System (INIS)

Ouyang, Wei; Huang, Haobo; Hao, Fanghua; Shan, Yushu; Guo, Bobo

2012-01-01

To better understand the spatial dynamics of non-point source (NPS) phosphorus loading with soil property at watershed scale, integrated modeling and soil chemistry is crucial to ensure that the indicator is functioning properly and expressing the spatial interaction at two depths. Developments in distributed modeling have greatly enriched the availability of geospatial data analysis and assess the NPS pollution loading response to soil property over larger area. The 1.5 km-grid soil sampling at two depths was analyzed with eight parameters, which provided detailed spatial and vertical soil data under four main types of landuses. The impacts of landuse conversion and agricultural practice on soil property were firstly identified. Except for the slightly bigger total of potassium (TK) and cadmium (Cr), the other six parameters had larger content in 20–40 cm surface than the top 20 cm surface. The Soil and Water Assessment Tool was employed to simulate the loading of NPS phosphorus. Overlaying with the landuse distribution, it was found that the NPS phosphorus mainly comes from the subbasins dominated with upland and paddy rice. The linear correlations of eight soil parameters at two depths with NPS phosphorus loading in the subbasins of upland and paddy rice were compared, respectively. The correlations of available phosphorus (AP), total phosphorus (TP), total nitrogen (TN) and TK varied in two depths, and also can assess the loading. The soil with lower soil organic carbon (SOC) presented a significant higher risk for NPS phosphorus loading, especially in agricultural area. The Principal Component Analysis showed that the TP and zinc (Zn) in top soil and copper (Cu) and Cr in subsurface can work as indicators. The analysis suggested that the application of soil property indicators is useful for assessing NPS phosphorus loss, which is promising for water safety in agricultural area. -- Highlights: ► Spatial dynamics of NPS phosphorus pollution with soil

Watershed Modeling Applications with the Open-Access Modular Distributed Watershed Educational Toolbox (MOD-WET) and Introductory Hydrology Textbook

Science.gov (United States)

Huning, L. S.; Margulis, S. A.

2014-12-01

Traditionally, introductory hydrology courses focus on hydrologic processes as independent or semi-independent concepts that are ultimately integrated into a watershed model near the end of the term. When an "off-the-shelf" watershed model is introduced in the curriculum, this approach can result in a potential disconnect between process-based hydrology and the inherent interconnectivity of processes within the water cycle. In order to curb this and reduce the learning curve associated with applying hydrologic concepts to complex real-world problems, we developed the open-access Modular Distributed Watershed Educational Toolbox (MOD-WET). The user-friendly, MATLAB-based toolbox contains the same physical equations for hydrological processes (i.e. precipitation, snow, radiation, evaporation, unsaturated flow, infiltration, groundwater, and runoff) that are presented in the companion e-textbook (http://aqua.seas.ucla.edu/margulis_intro_to_hydro_textbook.html) and taught in the classroom. The modular toolbox functions can be used by students to study individual hydrologic processes. These functions are integrated together to form a simple spatially-distributed watershed model, which reinforces a holistic understanding of how hydrologic processes are interconnected and modeled. Therefore when watershed modeling is introduced, students are already familiar with the fundamental building blocks that have been unified in the MOD-WET model. Extensive effort has been placed on the development of a highly modular and well-documented code that can be run on a personal computer within the commonly-used MATLAB environment. MOD-WET was designed to: 1) increase the qualitative and quantitative understanding of hydrological processes at the basin-scale and demonstrate how they vary with watershed properties, 2) emphasize applications of hydrologic concepts rather than computer programming, 3) elucidate the underlying physical processes that can often be obscured with a complicated

Simulation of rain in the watershed Ghezala by KINEROS 2 model

International Nuclear Information System (INIS)

Marghmi, Afef

2010-01-01

The objective of this study is modeling runoff by hydrological, distributed physically based Model, KINEROS2. This model has allowed after calibration to analyze and simulate the hydrological behavior of the watershed Ghezala .The Watershed Ghezala is located in north of Tunisia, in the governorate of Bizerte. It belongs to the bioclimatic mild winter. It covers an area of 4723h, at this watershed; the dominating slop is between 8and 15 pour cent which covers the almost area of the watershed. Dominant type of soil is Calcareous brown guy covering almost 54 pour cent of its total area; Land cover is characterized by the dominance of grain covering 73 pour cent of watershed area. KINEROS2 requires the division of the watershed into plain and channels cascading from upstream to downstream taking into consideration of flow, the geology and land cover of the watershed. During the calibration observed and simulated hydrographs, it must be based on the more sensitive parameters of the model: K (saturated hydraulic conductivity) G (net effective capillary conductivity) and n (parameter Mannig). The calibration's result shows that the error does not exceed, 1pour cent for liquid peak flows of flood hydrographs observed and simulated, 17pour cent for the volume of raw observed and simulated. Thus, the analysis of the hydrological behavior of the watershed studied through the hydrological response to a solicitation (intensity of rain: rain), simulates flood by applying the KINEROS2 model and observing the quantity of water flowing at the outflow of the system (flood hydrograph or rainfall).

Determination of Water Quality Status at Sampean Watershed Bondowoso Residence Using Storet Method

Science.gov (United States)

Sugiyarto; Hariono, B.; Destarianto, P.; Nuruddin, M.

2018-01-01

Sampean watershed has an important social and economic function for the people surroundings. Sampean watershed wich cover Bondowoso and Situbondo residence is an urban watershed that has strategic value for national context needs special traetment. Construction activity at upper and lower course of Sampean watershed is highly intensive and growth of inhabitant also increase. The change of land utilization and increase of settlement area at upper, midlle, and lower course caused polutant infiltration to Sampean river watershed so it has impact on water quality. The source of pollution at Sampean river comes from domestic waste, industrial waste, agricultural waste and animal husbandry waste. The purpose of this research is to determine load of pollution and analize the pollution load carrying capacity at Sampean watershed. The data used in this research are rainfall, river flow rate and water quality at 6 certain points within 3 years during 2014 until 2016. The method to determine overall pollution rate is STORET (Storage and Retrieval of Water Quality Data System) method. The analysis results for the first, second, third and forth grade are -24 (moderate quality), -12 (moderate quality), -2 (good quality), and 0 (good quality) respectively.

From ridge to reef—linking erosion and changing watersheds to impacts on the coral reef ecosystems of Hawai‘i and the Pacific Ocean

Science.gov (United States)

Stock, Jonathan D.; Cochran, Susan A.; Field, Michael E.; Jacobi, James D.; Tribble, Gordon

2011-01-01

Coral reef ecosystems are threatened by unprecedented watershed changes in the United States and worldwide. These ecosystems sustain fishing and tourism industries essential to the economic survival of many communities. Sediment, nutrients, and pollutants from watersheds are increasingly transported to coastal waters, where these contaminants damage corals. Although pollution from watersheds is one of many factors threatening coral survival, it is one that local people can have a profound influence on. U.S. Geological Survey scientists are using mapping, monitoring, and computer modeling to better forecast the effects of watershed changes on reef health. Working with communities in Hawai‘i and on other U.S. islands in the Pacific, they are helping to provide the science needed to make informed decisions on watershed and coral reef management.

Identifying fecal pollution sources using 3M(™) Petrifilm (™) count plates and antibiotic resistance analysis in the Horse Creek Watershed in Aiken County, SC (USA).

Science.gov (United States)

Harmon, S Michele; West, Ryan T; Yates, James R

2014-12-01

Sources of fecal coliform pollution in a small South Carolina (USA) watershed were identified using inexpensive methods and commonly available equipment. Samples from the upper reaches of the watershed were analyzed with 3M(™) Petrifilm(™) count plates. We were able to narrow down the study's focus to one particular tributary, Sand River, that was the major contributor of the coliform pollution (both fecal and total) to a downstream reservoir that is heavily used for recreation purposes. Concentrations of total coliforms ranged from 2,400 to 120,333 cfu/100 mL, with sharp increases in coliform counts observed in samples taken after rain events. Positive correlations between turbidity and fecal coliform counts suggested a relationship between fecal pollution and stormwater runoff. Antibiotic resistance analysis (ARA) compared antibiotic resistance profiles of fecal coliform isolates from the stream to those of a watershed-specific fecal source library (equine, waterfowl, canines, and untreated sewage). Known fecal source isolates and unknown isolates from the stream were exposed to six antibiotics at three concentrations each. Discriminant analysis grouped known isolates with an overall average rate of correct classification (ARCC) of 84.3 %. A total of 401 isolates from the first stream location were classified as equine (45.9 %), sewage (39.4 %), waterfowl (6.2 %), and feline (8.5 %). A similar pattern was observed at the second sampling location, with 42.6 % equine, 45.2 % sewage, 2.8 % waterfowl, 0.6 % canine, and 8.8 % feline. While there were slight weather-dependent differences, the vast majority of the coliform pollution in this stream appeared to be from two sources, equine and sewage. This information will contribute to better land use decisions and further justify implementation of low-impact development practices within this urban watershed.

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

Science.gov (United States)

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

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

Science.gov (United States)

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

Urban stormwater - greywater management system for sustainable urban water management at sub-watershed level

Science.gov (United States)

Singh Arora, Amarpreet

2017-11-01

Urban water management involves urban water supply (import, treatment and distribution of water), urban wastewater management (collection, treatment and disposal of urban sewage) and urban storm water management. Declining groundwater tables, polluted and declining sources of water, water scarcity in urban areas, unsatisfactory urban water supply and sanitation situation, pollution of receiving water bodies (including the ground water), and urban floods have become the concerns and issues of sustainable urban water management. This paper proposes a model for urban stormwater and sewage management which addresses these concerns and issues of sustainable urban water management. This model proposes segregation of the sewage into black water and greywater, and urban sub-watershed level stormwater-greywater management systems. During dry weather this system will be handling only the greywater and making the latter available as reclaimed water for reuse in place of the fresh water supply. During wet weather, the system will be taking care of (collection and treatment) both the storm water and the greywater, and the excess of the treated water will be disposed off through groundwater recharging. Application of this model in the Patiala city, Punjab, INDIA for selected urban sub-watersheds has been tried. Information and background data required for the conceptualization and design of the sub-watershed level urban stormwater-greywater management system was collected and the system has been designed for one of the sub-watersheds in the Patiala city. In this paper, the model for sustainable urban water management and the design of the Sub-watershed level Urban Stormwater-Greywater Management System are described.

A sensitivity analysis of regional and small watershed hydrologic models

Science.gov (United States)

Ambaruch, R.; Salomonson, V. V.; Simmons, J. W.

1975-01-01

Continuous simulation models of the hydrologic behavior of watersheds are important tools in several practical applications such as hydroelectric power planning, navigation, and flood control. Several recent studies have addressed the feasibility of using remote earth observations as sources of input data for hydrologic models. The objective of the study reported here was to determine how accurately remotely sensed measurements must be to provide inputs to hydrologic models of watersheds, within the tolerances needed for acceptably accurate synthesis of streamflow by the models. The study objective was achieved by performing a series of sensitivity analyses using continuous simulation models of three watersheds. The sensitivity analysis showed quantitatively how variations in each of 46 model inputs and parameters affect simulation accuracy with respect to five different performance indices.

Assessment of the Impact of Climate Change on the Water Balances and Flooding Conditions of Peninsular Malaysia watersheds by a Coupled Numerical Climate Model - Watershed Hydrology Model

Science.gov (United States)

Ercan, A.; Kavvas, M. L.; Ishida, K.; Chen, Z. Q.; Amin, M. Z. M.; Shaaban, A. J.

2017-12-01

Impacts of climate change on the hydrologic processes under future climate change conditions were assessed over various watersheds of Peninsular Malaysia by means of a coupled regional climate and physically-based hydrology model that utilized an ensemble of future climate change projections. An ensemble of 15 different future climate realizations from coarse resolution global climate models' (GCMs) projections for the 21st century were dynamically downscaled to 6 km resolution over Peninsular Malaysia by a regional numerical climate model, which was then coupled with the watershed hydrology model WEHY through the atmospheric boundary layer over the selected watersheds of Peninsular Malaysia. Hydrologic simulations were carried out at hourly increments and at hillslope-scale in order to assess the impacts of climate change on the water balances and flooding conditions at the selected watersheds during the 21st century. The coupled regional climate and hydrology model was simulated for a duration of 90 years for each of the 15 realizations. It is demonstrated that the increase in mean monthly flows due to the impact of expected climate change during 2040-2100 is statistically significant at the selected watersheds. Furthermore, the flood frequency analyses for the selected watersheds indicate an overall increasing trend in the second half of the 21st century.

Water quality trading opportunities in two sub-watersheds in the northern Lake Okeechobee watershed.

Science.gov (United States)

Corrales, Juliana; Naja, G Melodie; Bhat, Mahadev G; Miralles-Wilhelm, Fernando

2017-07-01

For decades, the increase of nutrient enrichment has threatened the ecological integrity and economic sustainability of many rivers, lakes, and coastal waters, including Lake Okeechobee, the second largest freshwater lake in the contiguous United States. Water quality trading programs have been an area of active development to both, reduce nutrient pollution and minimize abatement costs. The objective of this study was to apply a comprehensive modeling framework, integrating a hydrologic-water quality model with an economic model, to assess and compare the cost-effectiveness of a water quality trading program over a command-and-control approach in order to reduce phosphorus loadings to Lake Okeechobee. The Upper Kissimmee (UK) and Taylor Creek/Nubbin Slough (TCNS) sub-watersheds, identified as major sources of total phosphorus (TP) loadings to the lake, were selected for this analysis. The effect of different caps on the market potential was assessed while considering four factors: the least-cost abatement solutions, credit prices, potential cost savings, and credit supply and demand. Hypothetical trading scenarios were also developed, using the optimal caps selected for the two sub-watersheds. In both sub-watersheds, a phosphorus credit trading program was less expensive than the conventional command-and-control approach. While attaining cost-effectiveness, keeping optimal credit prices, and fostering market competition, phosphorus reduction targets of 46% and 32% were selected as the most appropriate caps in the UK and TCNS sub-watersheds, respectively. Wastewater treatment facilities and urban areas in the UK, and concentrated animal feeding operations in the TCNS sub-watershed were identified as potential credit buyers, whereas improved pastures were identified as the major credit sellers in both sub-watersheds. The estimated net cost savings resulting from implementing a phosphorus trading program in the UK and TCNS sub-watersheds were 76% ($ 34.9 million per

Application of snowmelt runoff model (SRM in mountainous watersheds: A review

Directory of Open Access Journals (Sweden)

Shalamu Abudu

2012-06-01

Full Text Available The snowmelt runoff model (SRM has been widely used in simulation and forecast of streamflow in snow-dominated mountainous basins around the world. This paper presents an overall review of worldwide applications of SRM in mountainous watersheds, particularly in data-sparse watersheds of northwestern China. Issues related to proper selection of input climate variables and parameters, and determination of the snow cover area (SCA using remote sensing data in snowmelt runoff modeling are discussed through extensive review of literature. Preliminary applications of SRM in northwestern China have shown that the model accuracies are relatively acceptable although most of the watersheds lack measured hydro-meteorological data. Future research could explore the feasibility of modeling snowmelt runoff in data-sparse mountainous watersheds in northwestern China by utilizing snow and glacier cover remote sensing data, geographic information system (GIS tools, field measurements, and innovative ways of model parameterization.

Watershed modeling tools and data for prognostic and diagnostic

Science.gov (United States)

Chambel-Leitao, P.; Brito, D.; Neves, R.

2009-04-01

When eutrophication is considered an important process to control it can be accomplished reducing nitrogen and phosphorus losses from both point and nonpoint sources and helping to assess the effectiveness of the pollution reduction strategy. HARP-NUT guidelines (Guidelines on Harmonized Quantification and Reporting Procedures for Nutrients) (Borgvang & Selvik, 2000) are presented by OSPAR as the best common quantification and reporting procedures for calculating the reduction of nutrient inputs. In 2000, OSPAR HARP-NUT guidelines on a trial basis. They were intended to serve as a tool for OSPAR Contracting Parties to report, in a harmonized manner, their different commitments, present or future, with regard to nutrients under the OSPAR Convention, in particular the "Strategy to Combat Eutrophication". HARP-NUT Guidelines (Borgvang and Selvik, 2000; Schoumans, 2003) were developed to quantify and report on the individual sources of nitrogen and phosphorus discharges/losses to surface waters (Source Orientated Approach). These results can be compared to nitrogen and phosphorus figures with the total riverine loads measured at downstream monitoring points (Load Orientated Approach), as load reconciliation. Nitrogen and phosphorus retention in river systems represents the connecting link between the "Source Orientated Approach" and the "Load Orientated Approach". Both approaches are necessary for verification purposes and both may be needed for providing the information required for the various commitments. Guidelines 2,3,4,5 are mainly concerned with the sources estimation. They present a set of simple calculations that allow the estimation of the origin of loads. Guideline 6 is a particular case where the application of a model is advised, in order to estimate the sources of nutrients from diffuse sources associated with land use/land cover. The model chosen for this was SWAT (Arnold & Fohrer, 2005) model because it is suggested in the guideline 6 and because it

Modeling the Effects of Onsite Wastewater Treatment Systems on Nitrate Loads Using SWAT in an Urban Watershed of Metropolitan Atlanta.

Science.gov (United States)

Hoghooghi, Nahal; Radcliffe, David E; Habteselassie, Mussie Y; Jeong, Jaehak

2017-05-01

Onsite wastewater treatment systems (OWTSs) can be a source of nitrogen (N) pollution in both surface and ground waters. In metropolitan Atlanta, GA, >26% of homes are on OWTSs. In a previous article, we used the Soil Water Assessment Tool to model the effect of OWTSs on stream flow in the Big Haynes Creek Watershed in metropolitan Atlanta. The objective of this study was to estimate the effect of OWTSs, including failing systems, on nitrate as N (NO-N) load in the same watershed. Big Haynes Creek has a drainage area of 44 km with mainly urban land use (67%), and most of the homes use OWTSs. A USGS gauge station where stream flow was measured daily and NO-N concentrations were measured monthly was used as the outlet. The model was simulated for 12 yr. Overall, the model showed satisfactory daily stream flow and NO-N loads with Nash-Sutcliffe coefficients of 0.62 and 0.58 for the calibration period and 0.67 and 0.33 for the validation period at the outlet of the Big Haynes Watershed. Onsite wastewater treatment systems caused an average increase in NO-N load of 23% at the watershed scale and 29% at the outlet of a subbasin with the highest density of OWTSs. Failing OWTSs were estimated to be 1% of the total systems and did not have a large impact on stream flow or NO-N load. The NO-N load was 74% of the total N load in the watershed, indicating the important effect of OWTSs on stream loads in this urban watershed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

MOBIDIC-U: a watershed-scale model for stormwater attenuation through green infrastructures design

Science.gov (United States)

Ercolani, G.; Masseroni, D.; Chiaradia, E. A.; Bischetti, G. B.; Gandolfi, C.; Castelli, F.

2017-12-01

Surface water degradation resulting from the effects of urbanization on hydrology, water quality, habitat as well as ecological and environmental compartments represents an issue of primary focus for multiple agencies at the national, regional and local levels. Many management actions are needed throughout urban watersheds to achieve the desired effects on flow mitigation and pollutant reduction, but no single standardized solution can be effective in all locations. In this work, the distributed hydrological model MOBIDIC, already applied for hydrological balance simulations and flood prevention in different Italian regions, is adapted to the urban context (MOBIDIC-U) in order to evaluate alternative plans for stormwater quality management and flow abatement techniques through the adoption of green infrastructures (GIs). In particular the new modules included in MOBIDIC-U allow to (i) automatically define the upstream flow path as well as watershed boundary starting from a selected watershed closure point on the urban drainage network and (ii) obtain suitable graphical outputs for the visualization of flow peak and volume attenuation at the closure point. Moreover, MOBIDIC-U provides a public domain tool capable of evaluating the optimal location, type, and cost of the stormwater management practices needed to meet water quantity and quality goals. Despite the scalability of the model to different urban contexts, the current version of MOBIDIC-U has been developed for the area of the metropolitan city of Milan, Northern Italy. The model is implemented on a GIS platform, which already contains (i) the structure of the urban drainage network of the metropolitan city of Milan; (ii) the database of actual geomorphological and meteorological data for the previous domain (iii) the list of potential GIs, their standard size, installation and maintenance costs. Therefore, MOBIDIC-U provides an easy to use tool to local professionals to design and evaluate urban stormwater

Effectiveness of low impact development practices in two urbanized watersheds: retrofitting with rain barrel/cistern and porous pavement.

Science.gov (United States)

Ahiablame, Laurent M; Engel, Bernard A; Chaubey, Indrajeet

2013-04-15

The impacts of urbanization on hydrology and water quality can be minimized with the use of low impact development (LID) practices in urban areas. This study assessed the performance of rain barrel/cistern and porous pavement as retrofitting technologies in two urbanized watersheds of 70 and 40 km(2) near Indianapolis, Indiana. Six scenarios consisting of the watershed existing condition, 25% and 50% implementation of rain barrel/cistern and porous pavement, and 25% rain barrel/cistern combined with 25% porous pavement were evaluated using a proposed LID modeling framework and the Long-Term Hydrologic Impact Assessment (L-THIA)-LID model. The model was calibrated for annual runoff from 1991 to 2000, and validated from 2001 to 2010 for the two watersheds. For the calibration period, R(2) and NSE values were greater than 0.60 and 0.50 for annual runoff and streamflow. Baseflow was not calibrated in this study. During the validation period, R(2) and NSE values were greater than 0.50 for runoff and streamflow, and 0.30 for baseflow in the two watersheds. The various application levels of barrel/cistern and porous pavement resulted in 2-12% reduction in runoff and pollutant loads for the two watersheds. Baseflow loads slightly increased with increase in baseflow by more than 1%. However, reduction in runoff led to reduction in total streamflow and associated pollutant loads by 1-9% in the watersheds. The results also indicate that the application of 50% rain barrel/cistern, 50% porous pavement and 25% rain barrel/cistern combined with 25% porous pavement are good retrofitting options in these watersheds. The L-THIA-LID model can be used to inform management and decision-making for implementation of LID practices at the watershed scale. Copyright © 2013. Published by Elsevier Ltd.

A SWAT model validation of nested-scale contemporaneous stream flow, suspended sediment and nutrients from a multiple-land-use watershed of the central USA.

Science.gov (United States)

Zeiger, Sean J; Hubbart, Jason A

2016-12-01

There is an ongoing need to validate the accuracy of predictive model simulated pollutant yields, particularly from multiple-land-use (i.e. forested, agricultural, and urban) watersheds. However, there are seldom sufficient observed data sets available that supply requisite spatial and temporal resolution and coupled multi-parameter constituents for rigorous model performance assessment. Four years of hydroclimate and water quality data were used to validate SWAT model estimates of monthly stream flow, suspended sediment, total phosphorus, nitrate, nitrite, ammonium, and total inorganic nitrogen from 5 nested-scale gauging sites located in a multiple-land-use watershed of the central USA. The uncalibrated SWAT model satisfactorily simulated monthly stream flow with Nash-Sutcliffe efficiency (NSE) values ranging from 0.50 near the headwaters, to 0.75 near the watershed outlet. However, the uncalibrated model did not accurately simulate monthly sediment, total phosphorus, nitrate, nitrite, ammonium, and total inorganic nitrogen with NSE valuesSWAT model to multiple gauging sites within the watershed improved estimates of monthly stream flow (NSE=0.83), sediment (NSE=0.78), total phosphorus (NSE=0.81), nitrate (NSE=0.90), and total inorganic nitrogen (NSE=0.86). However, NSE values were model performance decreased for sediment, nitrate, and total inorganic nitrogen during the validation period with NSE valuesSWAT model to multiple gauging sites and provide guidance to SWAT model (or similar models) users wishing to improve model performance at multiple scales. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatial modeling on the upperstream of the Citarum watershed: An application of geoinformatics

Science.gov (United States)

Ningrum, Windy Setia; Widyaningsih, Yekti; Indra, Tito Latif

2017-03-01

The Citarum watershed is the longest and the largest watershed in West Java, Indonesia, located at 106°51'36''-107°51' E and 7°19'-6°24'S across 10 districts, and serves as the water supply for over 15 million people. In this area, the water criticality index is concerned to reach the balance between water supply and water demand, so that in the dry season, the watershed is still able to meet the water needs of the society along the Citarum river. The objective of this research is to evaluate the water criticality index of Citarum watershed area using spatial model to overcome the spatial dependencies in the data. The result of Lagrange multiplier diagnostics for spatial dependence results are LM-err = 34.6 (p-value = 4.1e-09) and LM-lag = 8.05 (p-value = 0.005), then modeling using Spatial Lag Model (SLM) and Spatial Error Model (SEM) were conducted. The likelihood ratio test show that both of SLM dan SEM model is better than OLS model in modeling water criticality index in Citarum watershed. The AIC value of SLM and SEM model are 78.9 and 51.4, then the SEM model is better than SLM model in predicting water criticality index in Citarum watershed.

Cartographic modelling of aerotechnogenic pollution in snow cover in the landscapes of the Kola Peninsula.

Science.gov (United States)

Ratkin, N E; Asming, V E; Koshkin, V V

2001-01-01

The goal of this work was to develop computational techniques for sulphates, nickel and copper accumulation in the snow in the local pollution zone. The main task was to reveal the peculiarities of formation and pollution of snow cover on the region with complex cross-relief. A digital cartographic model of aerotechnogenic pollution of snow cover in the landscapes of the local zone has been developed, based on five-year experimental data. Data regarding annual emissions from the industrial complex, information about distribution of wind and the sum of precipitation from meteostation "Nikel" for the winter period, allowed the model to ensure: * material presentation in the form of maps of water capacity and accumulation of sulphates, nickel and copper in the snow over any winter period in retrospective; * calculation of water capacity and accumulation of pollutants for watersheds and other natural-territorial complexes; * solution of the opposite problem about the determination of the emissions of sulphates, nickel and copper from the enterprise by measuring snow pollution in datum points. The model can be used in other northern regions of the Russian Federation with similar physical-geographical and climatic conditions. The relationships between the sum of precipitation and water capacity in the landscapes of the same type and also the relationships between pollution content in snow and relief, pollution content in snow and distance from the source of emissions, were used as the basis for the model.

Upscaling from research watersheds: an essential stage of trustworthy general-purpose hydrologic model building

Science.gov (United States)

McNamara, J. P.; Semenova, O.; Restrepo, P. J.

2011-12-01

Highly instrumented research watersheds provide excellent opportunities for investigating hydrologic processes. A danger, however, is that the processes observed at a particular research watershed are too specific to the watershed and not representative even of the larger scale watershed that contains that particular research watershed. Thus, models developed based on those partial observations may not be suitable for general hydrologic use. Therefore demonstrating the upscaling of hydrologic process from research watersheds to larger watersheds is essential to validate concepts and test model structure. The Hydrograph model has been developed as a general-purpose process-based hydrologic distributed system. In its applications and further development we evaluate the scaling of model concepts and parameters in a wide range of hydrologic landscapes. All models, either lumped or distributed, are based on a discretization concept. It is common practice that watersheds are discretized into so called hydrologic units or hydrologic landscapes possessing assumed homogeneous hydrologic functioning. If a model structure is fixed, the difference in hydrologic functioning (difference in hydrologic landscapes) should be reflected by a specific set of model parameters. Research watersheds provide the possibility for reasonable detailed combining of processes into some typical hydrologic concept such as hydrologic units, hydrologic forms, and runoff formation complexes in the Hydrograph model. And here by upscaling we imply not the upscaling of a single process but upscaling of such unified hydrologic functioning. The simulation of runoff processes for the Dry Creek research watershed, Idaho, USA (27 km2) was undertaken using the Hydrograph model. The information on the watershed was provided by Boise State University and included a GIS database of watershed characteristics and a detailed hydrometeorological observational dataset. The model provided good simulation results in

Emerging pollutants in the Esmeraldas watershed in Ecuador: discharge and attenuation of emerging organic pollutants along the San Pedro-Guayllabamba-Esmeraldas rivers.

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Voloshenko-Rossin, A; Gasser, G; Cohen, K; Gun, J; Cumbal-Flores, L; Parra-Morales, W; Sarabia, F; Ojeda, F; Lev, O

2015-01-01

Water quality characteristics and emerging organic pollutants were sampled along the San Pedro-Guayllabamba-Esmeraldas River and its main water pollution streams in the summer of 2013. The annual flow rate of the stream is 22 000 Mm(3) y(-1) and it collects the wastewater of Quito-Ecuador in the Andes and supplies drinking water to the city of Esmeraldas near the Pacific Ocean. The most persistent emerging pollutants were carbamazepine and acesulfame, which were found to be stable along the San Pedro-Guayllabamba-Esmeraldas River, whereas the concentration of most other organic emerging pollutants, such as caffeine, sulfamethoxazole, venlafaxine, O-desmethylvenlafaxine, and steroidal estrogens, was degraded to a large extent along the 300 km flow. The mass rate of the sum of cocaine and benzoylecgonine, its metabolite, was increased along the stream, which may be attributed to coca plantations and wild coca trees. This raises the possibility of using river monitoring as an indirect way to learn about changes in coca plantations in their watersheds. Several organic emerging pollutants, such as venlafaxine, carbamazepine, sulphamethoxazole, and benzoylecgonine, survived even the filtration treatment at the Esmeraldas drinking water system, though all except for benzoylecgonine are found below 20 ng L(-1), and are therefore not likely to cause adverse health effects. The research provides a way to compare drug consumption in a major Latin American city (Quito) and shows that the consumption of most sampled drugs (carbamazepine, venlafaxine, O-desmethylvenlafaxine, sulphamethoxazole, ethinylestradiol) was below their average consumption level in Europe, Israel, and North America.

Development and testing of watershed-scale models for poorly drained soils

Science.gov (United States)

Glenn P. Fernandez; George M. Chescheir; R. Wayne Skaggs; Devendra M. Amatya

2005-01-01

Watershed-scale hydrology and water quality models were used to evaluate the crrmulative impacts of land use and management practices on dowrzstream hydrology and nitrogen loading of poorly drained watersheds. Field-scale hydrology and nutrient dyyrutmics are predicted by DRAINMOD in both models. In the first model (DRAINMOD-DUFLOW), field-scale predictions are coupled...

Mathematical modeling of synthetic unit hydrograph case study: Citarum watershed

Science.gov (United States)

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.

Non-point Source Pollution Modeling Using Geographic Information System (GIS for Representing Best Management Practices (BMP in the Gorganrood Watershed

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Z. Pasandidehfard

2014-09-01

Full Text Available The most important pollutants that cause water pollution are nitrogen and phosphorus from agricultural runoff called Non-Point Source Pollution (NPS. To solve this problem, management practices known as BMPs or Best Management Practices are applied. One of the common methods for Non-Point Source Pollution prediction is modeling. By modeling, efficiency of many practices can be tested before application. In this study, land use changes were studied from the years 1984 till 2010 that showed an increase in agricultural lands from 516908.52 to 630737.19 ha and expansion of cities from 5237.87 to 15487.59 ha and roads from 9666.07 to 11430.24 ha. Using L-THIA model (from nonpoint source pollution models for both land use categories, the amount of pollutant and the volume of runoff were calculated that showed high growth. Then, the seventh sub-basin was recognized as a critical zone in terms of pollution among the sub-basins. In the end, land use change was considered as a BMP using Multi-Criteria Evaluation (MCE based on which a more suitable land use map was produced. After producing the new land use map, L-THIA model was run again and the result of the model was compared to the actual land use to show the effect of this BMP. Runoff volume decreased from 367.5 to 308.6 M3/ha and nitrogen in runoff was reduced from 3.26 to 1.58 mg/L and water BOD from 3.61 to 2.13 mg/L. Other pollutants also showed high reduction. In the end, land use change is confirmed as an effective BMP for Non-Point Source Pollution reduction.

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

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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...

Application of a New Integrated Decision Support Tool (i-DST) for Urban Water Infrastructure: Analyzing Water Quality Compliance Pathways for Three Los Angeles Watersheds

Science.gov (United States)

Gallo, E. M.; Hogue, T. S.; Bell, C. D.; Spahr, K.; McCray, J. E.

2017-12-01

The water quality of receiving streams and waterbodies in urban watersheds are increasingly polluted from stormwater runoff. The implementation of Green Infrastructure (GI), which includes Low Impact Developments (LIDs) and Best Management Practices (BMPs), within a watershed aim to mitigate the effects of urbanization by reducing pollutant loads, runoff volume, and storm peak flow. Stormwater modeling is generally used to assess the impact of GIs implemented within a watershed. These modeling tools are useful for determining the optimal suite of GIs to maximize pollutant load reduction and minimize cost. However, stormwater management for most resource managers and communities also includes the implementation of grey and hybrid stormwater infrastructure. An integrated decision support tool, called i-DST, that allows for the optimization and comprehensive life-cycle cost assessment of grey, green, and hybrid stormwater infrastructure, is currently being developed. The i-DST tool will evaluate optimal stormwater runoff management by taking into account the diverse economic, environmental, and societal needs associated with watersheds across the United States. Three watersheds from southern California will act as a test site and assist in the development and initial application of the i-DST tool. The Ballona Creek, Dominguez Channel, and Los Angeles River Watersheds are located in highly urbanized Los Angeles County. The water quality of the river channels flowing through each are impaired by heavy metals, including copper, lead, and zinc. However, despite being adjacent to one another within the same county, modeling results, using EPA System for Urban Stormwater Treatment and Analysis INtegration (SUSTAIN), found that the optimal path to compliance in each watershed differs significantly. The differences include varied costs, suites of BMPs, and ancillary benefits. This research analyzes how the economic, physical, and hydrological differences between the three

ROLE OF WATERSHED SUBDIVISION ON MODELING THE EFFECTIVENESS OF BEST MANAGEMENT PRACTICES WITH SWAT

Science.gov (United States)

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

Watershed erosion modeling using the probability of sediment connectivity in a gently rolling system

Science.gov (United States)

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.

Evaluating Hydrologic Response of an Agricultural Watershed for Watershed Analysis

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Manoj Kumar Jha

2011-06-01

Full Text Available This paper describes the hydrological assessment of an agricultural watershed in the Midwestern United States through the use of a watershed scale hydrologic model. The Soil and Water Assessment Tool (SWAT model was applied to the Maquoketa River watershed, located in northeast Iowa, draining an agriculture intensive area of about 5,000 km2. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science Integrating Point and Nonpoint Sources (BASINS. Meteorological input, including precipitation and temperature from six weather stations located in and around the watershed, and measured streamflow data at the watershed outlet, were used in the simulation. A sensitivity analysis was performed using an influence coefficient method to evaluate surface runoff and baseflow variations in response to changes in model input hydrologic parameters. The curve number, evaporation compensation factor, and soil available water capacity were found to be the most sensitive parameters among eight selected parameters. Model calibration, facilitated by the sensitivity analysis, was performed for the period 1988 through 1993, and validation was performed for 1982 through 1987. The model was found to explain at least 86% and 69% of the variability in the measured streamflow data for calibration and validation periods, respectively. This initial hydrologic assessment will facilitate future modeling applications using SWAT to the Maquoketa River watershed for various watershed analyses, including watershed assessment for water quality management, such as total maximum daily loads, impacts of land use and climate change, and impacts of alternate management practices.

Evaluation of antibiotic resistance analysis and ribotyping for identification of faecal pollution sources in an urban watershed.

Science.gov (United States)

Moore, D F; Harwood, V J; Ferguson, D M; Lukasik, J; Hannah, P; Getrich, M; Brownell, M

2005-01-01

The accuracy of ribotyping and antibiotic resistance analysis (ARA) for prediction of sources of faecal bacterial pollution in an urban southern California watershed was determined using blinded proficiency samples. Antibiotic resistance patterns and HindIII ribotypes of Escherichia coli (n = 997), and antibiotic resistance patterns of Enterococcus spp. (n = 3657) were used to construct libraries from sewage samples and from faeces of seagulls, dogs, cats, horses and humans within the watershed. The three libraries were analysed to determine the accuracy of host source prediction. The internal accuracy of the libraries (average rate of correct classification, ARCC) with six source categories was 44% for E. coli ARA, 69% for E. coli ribotyping and 48% for Enterococcus ARA. Each library's predictive ability towards isolates that were not part of the library was determined using a blinded proficiency panel of 97 E. coli and 99 Enterococcus isolates. Twenty-eight per cent (by ARA) and 27% (by ribotyping) of the E. coli proficiency isolates were assigned to the correct source category. Sixteen per cent were assigned to the same source category by both methods, and 6% were assigned to the correct category. Addition of 2480 E. coli isolates to the ARA library did not improve the ARCC or proficiency accuracy. In contrast, 45% of Enterococcus proficiency isolates were correctly identified by ARA. None of the methods performed well enough on the proficiency panel to be judged ready for application to environmental samples. Most microbial source tracking (MST) studies published have demonstrated library accuracy solely by the internal ARCC measurement. Low rates of correct classification for E. coli proficiency isolates compared with the ARCCs of the libraries indicate that testing of bacteria from samples that are not represented in the library, such as blinded proficiency samples, is necessary to accurately measure predictive ability. The library-based MST methods used in

A novel tool for the communication of ecological risk assessment information in an urbanized watershed

International Nuclear Information System (INIS)

Zandbergen, P.

1995-01-01

A tool was developed for the communication of ecological risk assessment information on various types of point and nonpoint source pollution in the Brunette River watershed, an urbanized watershed in the Lower Mainland of British Columbia. The communication of ecological risks is a complex task, since the outcomes of quantitative ecological risk assessments are often not well understood by interested parties, and the results of the scientific analysis are generally quite different from the public perception of risk. Scientists should try to assist in the effective communication of their analysis by presenting it in a form more accessible to a variety of stakeholders, exposing the assessment process itself and the uncertainties in the analysis. This was attempted in developing a tool for the effective communication of ecological risk assessment information and management alternatives to the community in the watershed. Longstanding concerns over various forms of point and non-point sources of pollution in the watershed have resulted in a major effort to document the releases of pollutants, the exposure pathways, and the consequences for aquatic life. Extensive monitoring of ecosystem parameters, data-integration by means of a Geographic Information System, and the use of numerous databases and sub-models have resulted in the ecological risk assessment of four types of pollution in the watershed: petroleum fuels, metals, pesticides and basic industrial chemicals. Results will be presented of the attempts to integrate this information into a communication tool, which will demonstrate the principles, values and assumptions underlying the scientific analysis, as well as the quantitative end results and inherent uncertainties. The tool has been developed in close cooperation with several scientists who did most of the original data collection and with the feedback from some of the stakeholders in the community

Workshop to transfer VELMA watershed model results to Washington state tribes and state agencies engaged in watershed restoration and salmon recovery planning

Science.gov (United States)

An EPA Western Ecology Division (WED) watershed modeling team has been working with the Snoqualmie Tribe Environmental and Natural Resources Department to develop VELMA watershed model simulations of the effects of historical and future restoration and land use practices on strea...

Metals fate and transport modelling in streams and watersheds: state of the science and USEPA workshop review

Science.gov (United States)

Caruso, B.S.; Cox, T.J.; Runkel, Robert L.; Velleux, M.L.; Bencala, Kenneth E.; Nordstrom, D. Kirk; Julien, P.Y.; Butler, B.A.; Alpers, Charles N.; Marion, A.; Smith, Kathleen S.

2008-01-01

Metals pollution in surface waters from point and non-point sources (NPS) is a widespread problem in the United States and worldwide (Lofts et al., 2007; USEPA, 2007). In the western United States, metals associated with acid mine drainage (AMD) from hardrock mines in mountainous areas impact aquatic ecosystems and human health (USEPA, 1997a; Caruso and Ward, 1998; Church et al., 2007). Metals fate and transport modelling in streams and watersheds is sometimes needed for assessment and restoration of surface waters, including mining-impacted streams (Runkel and Kimball, 2002; Caruso, 2003; Velleux et al., 2006). The Water Quality Analysis Simulation Program (WASP; Wool et al., 2001), developed by the US Environmental Protection Agency (USEPA), is an example of a model used for such analyses. Other approaches exist and appropriate model selection depends on site characteristics, data availability and modelling objectives. However, there are a wide range of assumptions, input parameters, data requirements and gaps, and calibration and validation issues that must be addressed by model developers, users and decision makers. Despite substantial work on model development, their successful application has been more limited because they are not often used by decision makers for stream and watershed assessment and restoration. Bringing together scientists, model developers, users and decision makers should stimulate the development of appropriate models and improve the applicability of their results. To address these issues, the USEPA Office of Research and Development and Region 8 (Colorado, Montana, North Dakota, South Dakota, Utah and Wyoming) hosted a workshop in Denver, Colorado on February 13–14, 2007. The workshop brought together approximately 35 experts from government, academia and consulting to address the state of the art for modelling metals fate and transport, knowledge gaps and future directions in metals modelling. It focused on modelling metals in high

Evaluating the Effectiveness of Agricultural Management Practices under Climate Change for Water Quality Improvement in a Rural Agricultural Watershed of Oklahoma, USA

Science.gov (United States)

Rasoulzadeh Gharibdousti, S.; Kharel, G.; Stoecker, A.; Storm, D.

2016-12-01

One of the main causes of water quality impairment in the United States is human induced Non-Point Source (NPS) pollution through intensive agriculture. Fort Cobb Reservoir (FCR) watershed located in west-central Oklahoma, United States is a rural agricultural catchment with known issues of NPS pollution including suspended solids, siltation, nutrients, and pesticides. The FCR watershed with an area of 813 km2 includes one major lake fed by four tributaries. Recently, several Best Management Practices (BMPs) have been implemented in the watershed (such as no-tillage and cropland to grassland conversion) to improve water quality. In this study we aim to estimate the effectiveness of different BMPs in improving watershed health under future climate projections. We employed the Soil and Water Assessment Tool (SWAT) to develop the hydrological model of the FCR watershed. The watershed was delineated using the 10 m USGS Digital Elevation Model and divided into 43 sub-basins with an average area of 8 km2 (min. 0.2 km2 - max. 28 km2). Through a combination of Soil Survey Geographic Database- SSURGO soil data, the US Department of Agriculture crop layer and the slope information, the watershed was further divided into 1,217 hydrologic response units. The historical climate pattern in the watershed was represented by two different weather stations. The model was calibrated (1991 - 2000) and validated (2001 - 2010) against the monthly USGS observations of streamflow recorded at the watershed outlet using three statistical matrices: coefficient of determination (R2), Nash-Sutcliffe efficiency (NS) and percentage bias (PB). Model parametrization resulted into satisfactory values of R2 (0.56) and NS (0.56) in calibration period and an excellent model performance (R2 = 0.75; NS = 0.75; PB = water and sediment yields under a combination of three Coupled Model Intercomparison Project-5 Global Climate Model projections and two concentration pathways (4.5 and 8.5) downscaled to the

Development of Land Segmentation, Stream-Reach Network, and Watersheds in Support of Hydrological Simulation Program-Fortran (HSPF) Modeling, Chesapeake Bay Watershed, and Adjacent Parts of Maryland, Delaware, and Virginia

Science.gov (United States)

Martucci, Sarah K.; Krstolic, Jennifer L.; Raffensperger, Jeff P.; Hopkins, Katherine J.

2006-01-01

The U.S. Geological Survey, U.S. Environmental Protection Agency Chesapeake Bay Program Office, Interstate Commission on the Potomac River Basin, Maryland Department of the Environment, Virginia Department of Conservation and Recreation, Virginia Department of Environmental Quality, and the University of Maryland Center for Environmental Science are collaborating on the Chesapeake Bay Regional Watershed Model, using Hydrological Simulation Program - FORTRAN to simulate streamflow and concentrations and loads of nutrients and sediment to Chesapeake Bay. The model will be used to provide information for resource managers. In order to establish a framework for model simulation, digital spatial datasets were created defining the discretization of the model region (including the Chesapeake Bay watershed, as well as the adjacent parts of Maryland, Delaware, and Virginia outside the watershed) into land segments, a stream-reach network, and associated watersheds. Land segmentation was based on county boundaries represented by a 1:100,000-scale digital dataset. Fifty of the 254 counties and incorporated cities in the model region were divided on the basis of physiography and topography, producing a total of 309 land segments. The stream-reach network for the Chesapeake Bay watershed part of the model region was based on the U.S. Geological Survey Chesapeake Bay SPARROW (SPAtially Referenced Regressions On Watershed attributes) model stream-reach network. Because that network was created only for the Chesapeake Bay watershed, the rest of the model region uses a 1:500,000-scale stream-reach network. Streams with mean annual streamflow of less than 100 cubic feet per second were excluded based on attributes from the dataset. Additional changes were made to enhance the data and to allow for inclusion of stream reaches with monitoring data that were not part of the original network. Thirty-meter-resolution Digital Elevation Model data were used to delineate watersheds for each

A Customizable Dashboarding System for Watershed Model Interpretation

Science.gov (United States)

Easton, Z. M.; Collick, A.; Wagena, M. B.; Sommerlot, A.; Fuka, D.

2017-12-01

Stakeholders, including policymakers, agricultural water managers, and small farm managers, can benefit from the outputs of commonly run watershed models. However, the information that each stakeholder needs is be different. While policy makers are often interested in the broader effects that small farm management may have on a watershed during extreme events or over long periods, farmers are often interested in field specific effects at daily or seasonal period. To provide stakeholders with the ability to analyze and interpret data from large scale watershed models, we have developed a framework that can support custom exploration of the large datasets produced. For the volume of data produced by these models, SQL-based data queries are not efficient; thus, we employ a "Not Only SQL" (NO-SQL) query language, which allows data to scale in both quantity and query volumes. We demonstrate a stakeholder customizable Dashboarding system that allows stakeholders to create custom `dashboards' to summarize model output specific to their needs. Dashboarding is a dynamic and purpose-based visual interface needed to display one-to-many database linkages so that the information can be presented for a single time period or dynamically monitored over time and allows a user to quickly define focus areas of interest for their analysis. We utilize a single watershed model that is run four times daily with a combined set of climate projections, which are then indexed, and added to an ElasticSearch datastore. ElasticSearch is a NO-SQL search engine built on top of Apache Lucene, a free and open-source information retrieval software library. Aligned with the ElasticSearch project is the open source visualization and analysis system, Kibana, which we utilize for custom stakeholder dashboarding. The dashboards create a visualization of the stakeholder selected analysis and can be extended to recommend robust strategies to support decision-making.

流域水质管理优化决策模型研究%Watershed optimal decision models for water-quality management

Institute of Scientific and Technical Information of China (English)

盛虎; 向男; 郭怀成; 刘永

2013-01-01

针对目前流域水污染难以有效控制的局面,依据已有的流域水文、水动力、水质、水生态相关机理模拟模型的研究,在考虑了流域社会经济发展条件的基础上,构建了流域水质管理优化决策模型框架体系.基于该框架体系,本文从简单流域系统优化模型、模拟与优化联合模型和时空尺度复杂优化模型3个方面对流域优化决策模型的研究发展历程进行综述,并指出其各自在发展过程中所出现的问题.最后,提出了优化决策模型面临的瓶颈问题,并从模型结构简化和适应性管理两个方面提出了相关的解决思路.%In light of the difficulties in effective water pollution control, this study formulated a watershed optimal management decision model framework based on relevant researches on mechanistic modeling of watershed hydrology, hydrodynamics, water quality and aquatic ecology. The decision model framework also took into account the existing socio-economic development status in watersheds. Based on this framework, we reviewed the history and current status of watershed optimal decision support models from three different aspects; simple systematic optimization models, coupled simulation-optimization model, and complicated optimization models on different temporal and spatial scales. Meanwhile, the problems during the development of watershed optimization models were identified. Finally, in order to solve the bottle-neck of computation for watershed optimization models, simplification of the structure of simulation models and adaptive management were recommended.

Development of a Prototype Web-Based Decision Support System for Watershed Management

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Dejian Zhang

2015-02-01

Full Text Available Using distributed hydrological models to evaluate the effectiveness of reducing non-point source pollution by applying best management practices (BMPs is an important support to decision making for watershed management. However, complex interfaces and time-consuming simulations of the models have largely hindered the applications of these models. We designed and developed a prototype web-based decision support system for watershed management (DSS-WMRJ, which is user friendly and supports quasi-real-time decision making. DSS-WMRJ is based on integrating an open-source Web-based Geographical Information Systems (Web GIS tool (Geoserver, a modeling component (SWAT, Soil and Water Assessment Tool, a cloud computing platform (Hadoop and other open source components and libraries. In addition, a private cloud is used in an innovative manner to parallelize model simulations, which are time consuming and computationally costly. Then, the prototype DSS-WMRJ was tested with a case study. Successful implementation and testing of the prototype DSS-WMRJ lay a good foundation to develop DSS-WMRJ into a fully-fledged tool for watershed management. DSS-WMRJ can be easily customized for use in other watersheds and is valuable for constructing other environmental decision support systems, because of its performance, flexibility, scalability and economy.

Multi isotopic characterization (Li-Cu-Zn-Pb) of waste waters pollution in a small watershed (Loire River basin, France)

Science.gov (United States)

Millot, R.; Desaulty, A. M.; Perret, S.; Bourrain, X.

2016-12-01

The goal of this study is to use multi-isotopic signature to track the pollution in surface waters, and to understand the complex processes causing the metals mobilization and transport in the environment. In the present study, we investigate waste water releases from a hospital water treatment plant and its potential impact in a small river basin near Orléans in France (Egoutier watershed: 15 km²and 5 km long). We decided to monitor this small watershed which is poorly urbanized in the Loire river basin. Its spring is located in a pristine area (forested area), while it is only impacted some kilometers further by the releases rich in metals coming from a hospital water treatment plant. A sampling of these liquid effluents as well as dissolved load and sediment from upstream to downstream was realized and their concentrations and isotopic data were determined. Isotopic ratios were measured using a MC-ICP-MS at BRGM, after a specific protocol of purification for each isotopic systematics. Lithium isotopic compositions are rather homogeneous in river waters along the main course of the stream. The waste water signal is very different from the natural background with significant heavy lithium contribution (high δ7Li). Lead isotopic compositions are rather homogenous in river waters and sediments with values close to geologic background. For Zn, the sediments with high concentrations and depleted isotopic compositions (low δ66Zn), typical of an anthropic pollution, are strongly impacted. The analyses of Cu isotopes in sediments show the impact of waster waters, but also isotopic fractionations due to redox processes in the watershed. To better understand these processes controlling the release of metals in water, sequential extractions on sediments are in progress under laboratory conditions and will provide important constraints for metal distribution in this river basin.

Hydrosedimentological modeling of watershed in southeast Brazil, using SWAT

Directory of Open Access Journals (Sweden)

Maria Lúcia Calijuri

2010-08-01

Full Text Available The quantitative evaluation of soil loss due to erosion, of water loss and of load sediments that reach water bodies is fundamental to the environmental planning of a watershed, contributing to the process of decision for best options for soil tillage and water quality maintenance. Estimates of these data have been accomplished throughout the world using empiric or conceptual models. Besides being economically viable in scenarios development, environmental models may contribute to the location of critical areas, leading to emergency contention operations caused by erosive processes. Among these models, we highlight the SWAT (Soil and Water Assessment Tool which was applied in São Bartolomeu watershed, located in the Zona da Mata, Minas Gerais state, southeastern Brazil, to identify areas of greater sensitivity to erosion considering the soil type and land use. To validate the model, 10 experimental plots were installed in the dominant crops of the watershed between 2006 and 2008, for monitoring the runoff and soil losses under natural rainfall. Field results and simulations showed the SWAT efficiency for sediment yield and soil losses estimations, as they are influenced by factors such as soil moisture, rainfall intensity, soil type and land use (dominated by Oxisols, Ultisols, Inceptisols and Entisols. These losses can be reduced significantly by improving crops management of. A simulation scenario replacing pastures cover by Eucalyptus was introduced, which significantly reduced soil loss in many parts of the watershed.

Flood Frequency Analysis of Future Climate Projections in the Cache Creek Watershed

Science.gov (United States)

Fischer, I.; Trihn, T.; Ishida, K.; Jang, S.; Kavvas, E.; Kavvas, M. L.

2014-12-01

Effects of climate change on hydrologic flow regimes, particularly extreme events, necessitate modeling of future flows to best inform water resources management. Future flow projections may be modeled through the joint use of carbon emission scenarios, general circulation models and watershed models. This research effort ran 13 simulations for carbon emission scenarios (taken from the A1, A2 and B1 families) over the 21st century (2001-2100) for the Cache Creek watershed in Northern California. Atmospheric data from general circulation models, CCSM3 and ECHAM5, were dynamically downscaled to a 9 km resolution using MM5, a regional mesoscale model, before being input into the physically based watershed environmental hydrology (WEHY) model. Ensemble mean and standard deviation of simulated flows describe the expected hydrologic system response. Frequency histograms and cumulative distribution functions characterize the range of hydrologic responses that may occur. The modeled flow results comprise a dataset suitable for time series and frequency analysis allowing for more robust system characterization, including indices such as the 100 year flood return period. These results are significant for water quality management as the Cache Creek watershed is severely impacted by mercury pollution from historic mining activities. Extreme flow events control mercury fate and transport affecting the downstream water bodies of the Sacramento River and Sacramento- San Joaquin Delta which provide drinking water to over 25 million people.

A comparison of single- and multi-site calibration and validation: a case study of SWAT in the Miyun Reservoir watershed, China

Science.gov (United States)

Bai, Jianwen; Shen, Zhenyao; Yan, Tiezhu

2017-09-01

An essential task in evaluating global water resource and pollution problems is to obtain the optimum set of parameters in hydrological models through calibration and validation. For a large-scale watershed, single-site calibration and validation may ignore spatial heterogeneity and may not meet the needs of the entire watershed. The goal of this study is to apply a multi-site calibration and validation of the Soil andWater Assessment Tool (SWAT), using the observed flow data at three monitoring sites within the Baihe watershed of the Miyun Reservoir watershed, China. Our results indicate that the multi-site calibration parameter values are more reasonable than those obtained from single-site calibrations. These results are mainly due to significant differences in the topographic factors over the large-scale area, human activities and climate variability. The multi-site method involves the division of the large watershed into smaller watersheds, and applying the calibrated parameters of the multi-site calibration to the entire watershed. It was anticipated that this case study could provide experience of multi-site calibration in a large-scale basin, and provide a good foundation for the simulation of other pollutants in followup work in the Miyun Reservoir watershed and other similar large areas.

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

Science.gov (United States)

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

Hydrological modeling of the Simly Dam watershed (Pakistan) using GIS and SWAT model

OpenAIRE

Shimaa M. Ghoraba

2015-01-01

Modern mathematical models have been developed for studying the complex hydrological processes of a watershed and their direct relation to weather, topography, geology and land use. In this study the hydrology of Simly Dam watershed located in Saon River basin at the north-east of Islamabad is modeled, using the Soil and Water Assessment Tool (SWAT). It aims to simulate the stream flow, establish the water balance and estimate the monthly volume inflow to Simly Dam in order to help the manage...

[Output characteristics of rainfall runoff phosphorus pollution from a typical small watershed in Yimeng mountainous area].

Science.gov (United States)

Yu, Xing-xiu; Li, Zhen-wei; Liu, Qian-jin; Jing, Guang-hua

2012-08-01

Relationships between phosphorus pollutant concentrations and precipitation-runoff were analyzed by monitoring pollutant losses at outlets of the Menglianggu watershed in 2010. A typical small watershed was selected to examine the runoff and quality parameters such as total phosphorus (TP), particle phosphorus (PP), dissolve phosphorus (DP) and dissolve inorganic phosphorus (DIP) in rainfall-runoff of 10 rainfall events. Precipitation was above 2 mm for all the 10 rainfall events. The results showed that the peak of phosphorus concentrations occurred before the peak of water flows, whereas change processes of the phosphorus fluxes were consistent with that of the water flows and the phosphorus flux also have a strong linear relationship with the water flows. The minimums of the phosphorus concentrations in every 10 natural rainfall events have small differences with each other, but the maximum and EMCs of the phosphorus concentrations have significant differences with each rainfall event. This was mainly influenced by the precipitation, maximum rainfall intensity and mean rainfall intensity (EMCs) and was less influenced by rainfall duration. DP and TP were mainly composed of DIP and PP, respectively. There were no significant correlations between DIP/DP dynamic changes and rainfall characteristics, whereas significant correlations between PP/TP dynamic changes and maximum rainfall intensity were detected. The production of DIP, DP, AND TP were mainly influenced by the direct runoff (DR) and base flow (BF). The EMCs of DIP, DP, TP and the variations of DIP/DP were all found to have significant polynomial relationships with DR/TR., but the dynamic changes of PP/ TP and the EMCS of PP were less influenced by the DR/TR.

Modeling of land use and reservoir effects on nonpoint source pollution in a highly agricultural basin

Science.gov (United States)

Wu, Yiping; Liu, Shu-Guang

2012-01-01

Nonpoint source (NPS) pollution is tightly linked to land use activities that determine the sources and magnitudes of pollutant loadings to stream water. The pollutant loads may also be alleviated within reservoirs because of the physical interception resulting from changed hydrological regimes and other biochemical processes. It is important but challenging to assess the NPS pollution processes with human effects due to the measurement limitations. The objective of this study is to evaluate the effects of human activities such as land uses and reservoir operation on the hydrological and NPS pollution processes in a highly agricultural area-the Iowa River Basin-using the Soil and Water Assessment Tool (SWAT). The evaluation of model performance at multiple sites reveals that SWAT can consistently simulate the daily streamflow, and monthly/annual sediment and nutrient loads (nitrate nitrogen and mineral phosphorus) in the basin. We also used the calibrated model to estimate the trap efficiencies of sediment (~78%) and nutrients (~30%) in the Coralville Reservoir within the basin. These non-negligible effects emphasize the significance of incorporating the sediment and nutrient removal mechanisms into watershed system studies. The spatial quantification of the critical NPS pollution loads can help identify hot-spot areas that are likely locations for the best management practices.

MOSSES AS BIOINDICATORS OF AIR POLLUTION ALONG AN URBAN–AGRICULTURAL TRANSECT IN THE CREDIT RIVER WATERSHED, SOUTHERN ONTARIO, CANADA

Directory of Open Access Journals (Sweden)

P. Cowden

2015-04-01

Full Text Available The activities associated with urbanization, such as vehicular traffic and industrial processes, lead to elevated emissions of atmospheric pollutants. Measuring the spatial extent of these pollutants is pivotal to identifying areas of concern and assessing mitigation measures. The objective of this study was to evaluate the relative deposition of heavy metals and nitrogen using moss species along an urban–agricultural transition in the Credit River Watershed, southern Ontario. Thirteen species of moss were collected from Sugar Maple (Acer saccharum dominated forest stands across the study area, with only one moss species (Atrichum altercristatum commonly occurring. Heavy metal concentrations were variable between species; the Coefficient of Variation (CV for the majority of metals (Al, V, Cr, Fe, Ni, As, Sb and Pb was greater than ~50% across species. Nonetheless, metals exhibited similar trends, with the highest concentrations for Fe, followed by Al > Zn > Cu > Pb > Cr > Ni > V > As > Cd > Sb > Hg across species. Heavy metal concentrations in Atrichum altercristatum exhibited lower variability between sites, with CV < 33% for most metals (Cu, Zn, As, Cd, Sb, Pb and Hg. Further, many metal concentrations were strongly correlated (e.g., Al, V, Cr, Fe, and As; r ≤ 0.90 suggesting common emission sources, such as wind blown dust from agricultural activities or vehicular traffic, both predominant throughout the watershed.

[GIS and scenario analysis aid to water pollution control planning of river basin].

Science.gov (United States)

Wang, Shao-ping; Cheng, Sheng-tong; Jia, Hai-feng; Ou, Zhi-dan; Tan, Bin

2004-07-01

The forward and backward algorithms for watershed water pollution control planning were summarized in this paper as well as their advantages and shortages. The spatial databases of water environmental function region, pollution sources, monitoring sections and sewer outlets were built with ARCGIS8.1 as the platform in the case study of Ganjiang valley, Jiangxi province. Based on the principles of the forward algorithm, four scenarios were designed for the watershed pollution control. Under these scenarios, ten sets of planning schemes were generated to implement cascade pollution source control. The investment costs of sewage treatment for these schemes were estimated by means of a series of cost-effective functions; with pollution source prediction, the water quality was modeled with CSTR model for each planning scheme. The modeled results of different planning schemes were visualized through GIS to aid decision-making. With the results of investment cost and water quality attainment as decision-making accords and based on the analysis of the economic endurable capacity for water pollution control in Ganjiang river basin, two optimized schemes were proposed. The research shows that GIS technology and scenario analysis can provide a good guidance to the synthesis, integrity and sustainability aspects for river basin water quality planning.

Evaluating Hydrologic Response of an Agricultural Watershed for Watershed Analysis

OpenAIRE

Manoj Kumar Jha

2011-01-01

This paper describes the hydrological assessment of an agricultural watershed in the Midwestern United States through the use of a watershed scale hydrologic model. The Soil and Water Assessment Tool (SWAT) model was applied to the Maquoketa River watershed, located in northeast Iowa, draining an agriculture intensive area of about 5,000 km2. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science...

Modeling of phosphorus fluxes produced by wild fires at watershed scales.

Science.gov (United States)

Matyjasik, M.; Hernandez, M.; Shaw, N.; Baker, M.; Fowles, M. T.; Cisney, T. A.; Jex, A. P.; Moisen, G.

2017-12-01

River runoff is one of the controlling processes in the terrestrial phosphorus cycle. Phosphorus is often a limiting factor in fresh water. One of the factors that has not been studied and modeled in detail is phosporus flux produced from forest wild fires. Phosphate released by weathering is quickly absorbed in soils. Forest wild fires expose barren soils to intensive erosion, thus releasing relatively large fluxes of phosphorus. Measurements from three control burn sites were used to correlate erosion with phosphorus fluxes. These results were used to model phosphorus fluxes from burned watersheds during a five year long period after fires occurred. Erosion in our model is simulated using a combination of two models: the WEPP (USDA Water Erosion Prediction Project) and the GeoWEPP (GIS-based Water Erosion Prediction Project). Erosion produced from forest disturbances is predicted for any watershed using hydrologic, soil, and meteorological data unique to the individual watersheds or individual slopes. The erosion results are modified for different textural soil classes and slope angles to model fluxes of phosphorus. The results of these models are calibrated using measured concentrations of phosphorus for three watersheds located in the Interior Western United States. The results will help the United States Forest Service manage phosporus fluxes in national forests.

Modeling Mitigation Activities in North Carolina Watersheds

Science.gov (United States)

Garcia, A. M.

2017-12-01

Nutrient enrichment and excessive sediment loadings have contributed to the degradation of rivers, lakes and estuaries in North Carolina. The North Carolina Department of Environmental Quality (NCDEQ) has implemented several basin-wide nutrient and sediment management strategies, yet gaps remain in understanding the impact of these strategies given the complexities in quantifying the processes that govern the transport of nutrient and sediment. In particular, improved assessment of the status of nutrient and sediment loadings to lakes and estuaries throughout the state is needed, including characterizing their sources and describing the relative contributions of different areas. The NCDEQ Division of Mitigation Services (DMS) uses watershed planning to identify and prioritize the best locations to implement stream, wetland, and riparian-buffer restoration to improve water quality. To support better decision-making for watershed restoration activities we are developing a SPARROW (SPAtially Referenced Regressions On Watershed attributes) model framework specifically for North Carolina. The SPARROW analysis (developed by the U.S. Geological Survey) relates water-quality monitoring data to better understand the effects of human activities and natural processes on surface-water quality. The core of the model consists of using a nonlinear-regression equation to describe the non-conservative transport of contaminants from point and nonpoint sources on land to rivers, lakes and estuaries through the stream and river network. In this presentation, preliminary total Nitrogen, total Phosphorus, and Total Suspended Solids (TSS) NC-SPARROW models are described that illustrate the SPARROW modeling framework incorporating specific restoration datasets and activity metrics, such as extent of riparian buffer and easements.

Modeling of water erosion in the watershed of the siliana KINEROS2 model

International Nuclear Information System (INIS)

Raboudi, Abir

2016-01-01

The main objective of this work is was the modeling of flowing of the surface and the solid transport within the watershed of Siliana, in the Tunisian backings, by a model which is a physically specialized KINEROS 2. This model allowed us to decide the process of interception of infiltration, flowing of the surface, and of the erosion in small agricultural or urban watershed. KINEROS2 is applied on a watershed of 1039 m 2 and of a perimeter 183,3 km on 20 years over years of observation. We are described the different steps of making use of this model which are: data preparation parameters estimations, the analyses of the principals' parameters sensibility, model calibration and its validity and the overall estimation of solid transport. The KINEROS2 application necessitates the craving of the watershed in plains and channels, which are reported in succession of the upstream towards the downstream taking into consideration the direction of the flowing of the watercourse, of the geology and of the soil occupation of the watershed. Different parameters are calculated (porosity, peak, morphological parameters of plain and channels) estimated (Manning coefficient, net effective ground conductivity) and measured on a plot (spacing, relief). Model adjusting was done on many numeric criteria, which permit to compare and appreciate stand quality, and of validity between the observed and estimated quantities. The stand of observed and estimated hydro grams was carried out learning in mind the sensibility of parameters K, G and n in the model. The model calibration gave some satisfying results highlighted by the errors that don't exceed 4 pour cent for the flow of the liquid peak and 3 pour cent for the volume of the swelling observed and calculated. For the solid transport, the stand was archived by the variation of parameters that are the most sensible (ch) and (spl). The results will be judged acceptable because the mistake doesn't exceed 1%. Sediment

Assessing critical source areas in watersheds for conservation buffer planning and riparian restoration.

Science.gov (United States)

Qiu, Zeyuan

2009-11-01

A science-based geographic information system (GIS) approach is presented to target critical source areas in watersheds for conservation buffer placement. Critical source areas are the intersection of hydrologically sensitive areas and pollutant source areas in watersheds. Hydrologically sensitive areas are areas that actively generate runoff in the watershed and are derived using a modified topographic index approach based on variable source area hydrology. Pollutant source areas are the areas in watersheds that are actively and intensively used for such activities as agricultural production. The method is applied to the Neshanic River watershed in Hunterdon County, New Jersey. The capacity of the topographic index in predicting the spatial pattern of runoff generation and the runoff contribution to stream flow in the watershed is evaluated. A simple cost-effectiveness assessment is conducted to compare the conservation buffer placement scenario based on this GIS method to conventional riparian buffer scenarios for placing conservation buffers in agricultural lands in the watershed. The results show that the topographic index reasonably predicts the runoff generation in the watershed. The GIS-based conservation buffer scenario appears to be more cost-effective than the conventional riparian buffer scenarios.

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

Science.gov (United States)

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

Lumped Parameter Models for Predicting Nitrogen Transport in Lower Coastal Plain Watersheds

Science.gov (United States)

Devendra M. Amatya; George M. Chescheir; Glen P. Fernandez; R. Wayne Skaggs; F. Birgand; J.W. Gilliam

2003-01-01

hl recent years physically based comprehensive disfributed watershed scale hydrologic/water quality models have been developed and applied 10 evaluate cumulative effects of land arld water management practices on receiving waters, Although fhesc complex physically based models are capable of simulating the impacts ofthese changes in large watersheds, they are often...

SWAT meta-modeling as support of the management scenario analysis in large watersheds.

Science.gov (United States)

Azzellino, A; Çevirgen, S; Giupponi, C; Parati, P; Ragusa, F; Salvetti, R

2015-01-01

In the last two decades, numerous models and modeling techniques have been developed to simulate nonpoint source pollution effects. Most models simulate the hydrological, chemical, and physical processes involved in the entrainment and transport of sediment, nutrients, and pesticides. Very often these models require a distributed modeling approach and are limited in scope by the requirement of homogeneity and by the need to manipulate extensive data sets. Physically based models are extensively used in this field as a decision support for managing the nonpoint source emissions. A common characteristic of this type of model is a demanding input of several state variables that makes the calibration and effort-costing in implementing any simulation scenario more difficult. In this study the USDA Soil and Water Assessment Tool (SWAT) was used to model the Venice Lagoon Watershed (VLW), Northern Italy. A Multi-Layer Perceptron (MLP) network was trained on SWAT simulations and used as a meta-model for scenario analysis. The MLP meta-model was successfully trained and showed an overall accuracy higher than 70% both on the training and on the evaluation set, allowing a significant simplification in conducting scenario analysis.

Spatial distribution and source apportionment of water pollution in different administrative zones of Wen-Rui-Tang (WRT) river watershed, China.

Science.gov (United States)

Yang, Liping; Mei, Kun; Liu, Xingmei; Wu, Laosheng; Zhang, Minghua; Xu, Jianming; Wang, Fan

2013-08-01

Water quality degradation in river systems has caused great concerns all over the world. Identifying the spatial distribution and sources of water pollutants is the very first step for efficient water quality management. A set of water samples collected bimonthly at 12 monitoring sites in 2009 and 2010 were analyzed to determine the spatial distribution of critical parameters and to apportion the sources of pollutants in Wen-Rui-Tang (WRT) river watershed, near the East China Sea. The 12 monitoring sites were divided into three administrative zones of urban, suburban, and rural zones considering differences in land use and population density. Multivariate statistical methods [one-way analysis of variance, principal component analysis (PCA), and absolute principal component score-multiple linear regression (APCS-MLR) methods] were used to investigate the spatial distribution of water quality and to apportion the pollution sources. Results showed that most water quality parameters had no significant difference between the urban and suburban zones, whereas these two zones showed worse water quality than the rural zone. Based on PCA and APCS-MLR analysis, urban domestic sewage and commercial/service pollution, suburban domestic sewage along with fluorine point source pollution, and agricultural nonpoint source pollution with rural domestic sewage pollution were identified to the main pollution sources in urban, suburban, and rural zones, respectively. Understanding the water pollution characteristics of different administrative zones could put insights into effective water management policy-making especially in the area across various administrative zones.

Modeling conservation practices in APEX: From the field to the watershed

Science.gov (United States)

The evaluation of USDA conservation programs is required as part of the Conservation Effects Assessment Project (CEAP). The Agricultural Policy/Environmental eXtender (APEX) model was applied to the St. Joseph River Watershed, one of CEAP’s benchmark watersheds. Using a previously calibrated and val...

Characterization and source identification of pollutants in runoff from a mixed land use watershed using ordination analyses.

Science.gov (United States)

Lee, Dong Hoon; Kim, Jin Hwi; Mendoza, Joseph A; Lee, Chang Hee; Kang, Joo-Hyon

2016-05-01

While identification of critical pollutant sources is the key initial step for cost-effective runoff management, it is challenging due to the highly uncertain nature of runoff pollution, especially during a storm event. To identify critical sources and their quantitative contributions to runoff pollution (especially focusing on phosphorous), two ordination methods were used in this study: principal component analysis (PCA) and positive matrix factorization (PMF). For the ordination analyses, we used runoff quality data for 14 storm events, including data for phosphorus, 11 heavy metal species, and eight ionic species measured at the outlets of subcatchments with different land use compositions in a mixed land use watershed. Five factors as sources of runoff pollutants were identified by PCA: agrochemicals, groundwater, native soils, domestic sewage, and urban sources (building materials and automotive activities). PMF identified similar factors to those identified by PCA, with more detailed source mechanisms for groundwater (i.e., nitrate leaching and cation exchange) and urban sources (vehicle components/motor oils/building materials and vehicle exhausts), confirming the sources identified by PCA. PMF was further used to quantify contributions of the identified sources to the water quality. Based on the results, agrochemicals and automotive activities were the two dominant and ubiquitous phosphorus sources (39-61 and 16-47 %, respectively) in the study area, regardless of land use types.

Modeling of water erosion by seagis model. Case Watershed Dam Siliana

International Nuclear Information System (INIS)

Chabaan, Chayma

2016-01-01

water erosion is a complicated phenomenon, largely obvious in north Africa, especially in the watershed of Siliana, where natural factors and the aggressiveness of the environment do affect the loss of soil there, which characterized by a form so uneven with attitudes that vary from 700 to 1350 m rigid going from 5 to 10 pour cent and sometimes more. Moreover, it has drained with a thick hydrographic network. Generally, water erosion depends of the importance and the frequent agent factor of this erosion ( rain and streaming), soil type, the topography and the occupation of soil. The usage of mathematic models has to take on consideration of these parameters. The main objective of this work consist in developing put into affect a geomatic approach of stimulation which aims at estimate in time and space, the impact of the climate, and the soil occupation on the water erosion and the transportation of the sediments diversions into sliding of a small watershed. Locally, this approach allows evaluating the parameters of water erosion of SEAGIS model (USLE/RUSLE) to an extent that is identifies and drowing the emergency areas of intervention in the watershed of Siliana.

Assessment of terrain slope influence in SWAT modeling of Andean watersheds

Science.gov (United States)

Yacoub, C.; Pérez-Foguet, A.

2009-04-01

Hydrological processes in the Andean Region are difficult to model. Large range of altitudes involved (from over 4000 meters above sea level, masl, to zero) indicates the high variability of rainfall, temperature and other climate variables. Strong runoff and extreme events as landslides and floods are the consequence of high slopes of terrain, especially in the upper part of the basins. Strong seasonality of rain and complex ecosystems (vulnerable to climate changes and anthropogenic activities) helps these processes. Present study focuses in a particular watershed from Peruvian Andes, the Jequetepeque River. The distributed watershed simulation model, Soil and Water Assessment Tool (SWAT) is applied to model run-off and sediments transport through the basin with data from 1997 to 2006. Specifically, the study focuses in the assessment of the influence of considering terrain slope variation in the definition of Hydrographical Response Units within SWAT. The Jequetepeque watershed (4 372.5 km2) is located in the north part of Peru. River flows east to west, to the Pacific Ocean. Annual average precipitation ranges from 0 to 1100 mm and altitude from 0 to 4188 masl. The "Gallito Ciego" reservoir (400 masl) separates upper-middle part from lower part of the watershed. It stores water for supplying the people from the big cities on the coast and for extensive agriculture uses. Upper-middle part of the watershed covers 3564.8 km2. It ranges from 400 to 4188 masl in no more that 80 km, with slopes up to 20%. Main activities are agricultural and livestock and mining and about 80% of the population are rural. Annual mean temperature drops from 25.4 °C at the reservoir to less than 4 °C in the upper part. Also the highest rainfall variability is found in the upper-middle part of the watershed. Erosion produced by extreme events like 1997/98 "el Niño" Phenomenon is silting the reservoir faster than expected. Moreover, anthropogenic activities like agriculture and

Downeast Drainage - Examining and Communicating the Dynamics of Bacteria Pollution Events in the Gulf of Maine

Science.gov (United States)

Smith, S. M.; Brady, D. C.; Cole, K. L.; Jones, S.; McGreavy, B.; Petersen, C.; Rothenheber, D.; Gerard, B.; Roy, S. G.

2015-12-01

The New England Sustainability Consortium is an interdisciplinary NSF EPSCoR funded project organized to strengthen the connections between science and decision-making and to advance the practice of sustainability science. The project uses complementary research capacity at several institutions to examine watershed and estuarine processes linked to bacteria pollution affecting shellfish harvesting and beach water quality in the Gulf of Maine. A fundamental research target is the development of a better approach for the prediction of coastal bacteria pollution events that can cause losses in tourism and shellfishery revenue. Enhanced prediction and communication of the events require a simultaneous examination of watershed pollution sources, drainage systems, estuarine residence times and bacterial survival. Our presentation will summarize initial observations from our investigations and stakeholder engagement activities at two project reference sites located in Wells and Bar Harbor, Maine. These will include field measurements, watershed and estuarine modeling outcomes, and stakeholder engagement results that are framed to quantify and explain land-sea interactions linked to bacterial pollution events in locations with varied relief, hydrodynamics, and stakeholder communities.

Baseline for Climate Change: Modeling Watershed Aquatic Biodiversity Relative to Environmental and Anthropogenic Factors

Energy Technology Data Exchange (ETDEWEB)

Maurakis, Eugene G

2010-10-01

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, knowledge 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.

Investigating the effects of point source and nonpoint source pollution on the water quality of the East River (Dongjiang) in South China

Science.gov (United States)

Wu, Yiping; Chen, Ji

2013-01-01

Understanding the physical processes of point source (PS) and nonpoint source (NPS) pollution is critical to evaluate river water quality and identify major pollutant sources in a watershed. In this study, we used the physically-based hydrological/water quality model, Soil and Water Assessment Tool, to investigate the influence of PS and NPS pollution on the water quality of the East River (Dongjiang in Chinese) in southern China. Our results indicate that NPS pollution was the dominant contribution (>94%) to nutrient loads except for mineral phosphorus (50%). A comprehensive Water Quality Index (WQI) computed using eight key water quality variables demonstrates that water quality is better upstream than downstream despite the higher level of ammonium nitrogen found in upstream waters. Also, the temporal (seasonal) and spatial distributions of nutrient loads clearly indicate the critical time period (from late dry season to early wet season) and pollution source areas within the basin (middle and downstream agricultural lands), which resource managers can use to accomplish substantial reduction of NPS pollutant loadings. Overall, this study helps our understanding of the relationship between human activities and pollutant loads and further contributes to decision support for local watershed managers to protect water quality in this region. In particular, the methods presented such as integrating WQI with watershed modeling and identifying the critical time period and pollutions source areas can be valuable for other researchers worldwide.

Watershed modeling at the Savannah River Site.

Energy Technology Data Exchange (ETDEWEB)

Vache, Kellie [Oregon State University

2015-04-29

The overall goal of the work was the development of a watershed scale model of hydrological function for application to the US Department of Energy’s (DOE) Savannah River Site (SRS). The primary outcomes is a grid based hydrological modeling system that captures near surface runoff as well as groundwater recharge and contributions of groundwater to streams. The model includes a physically-based algorithm to capture both evaporation and transpiration from forestland.

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

Science.gov (United States)

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

Long-term survey of heavy-metal pollution, biofilm contamination and diatom community structure in the Riou Mort watershed, South-West France

International Nuclear Information System (INIS)

Morin, S.; Duong, T.T.; Dabrin, A.; Coynel, A.; Herlory, O.; Baudrimont, M.; Delmas, F.; Durrieu, G.; Schaefer, J.; Winterton, P.; Blanc, G.; Coste, M.

2008-01-01

In a metal-polluted stream in the Riou Mort watershed in SW France, periphytic biofilm was analyzed for diatom cell densities and taxonomic composition, dry weight and metal bio-accumulation (cadmium and zinc). Periphytic diatom communities were affected by the metal but displayed induced tolerance, seen through structural impact (dominance of small, adnate species) as well as morphological abnormalities particularly in the genera Ulnaria and Fragilaria. Species assemblages were characterized by taxa known to occur in metal-polluted environments, and shifts in the community structure expressed seasonal patterns: high numbers of Eolimna minima, Nitzschia palea and Pinnularia parvulissima were recorded in Summer and Autumn, whereas the species Surirella brebissonii, Achnanthidium minutissimum, Navicula lanceolata and Surirella angusta were dominant in Winter and Spring. Commonly used indices such as the Shannon diversity index and Specific Pollution Sensitivity Index reflected the level of pollution and suggest seasonal periodicity, the lowest diversities being observed in Summer. - Periphytic biofilm diatom communities are suitable indicators for the bioassay of elevated levels of metals in contaminated river water

Nitrate source apportionment in a subtropical watershed using Bayesian model

International Nuclear Information System (INIS)

Yang, Liping; Han, Jiangpei; Xue, Jianlong; Zeng, Lingzao; Shi, Jiachun; Wu, Laosheng; Jiang, Yonghai

2013-01-01

Nitrate (NO 3 − ) pollution in aquatic system is a worldwide problem. The temporal distribution pattern and sources of nitrate are of great concern for water quality. The nitrogen (N) cycling processes in a subtropical watershed located in Changxing County, Zhejiang Province, China were greatly influenced by the temporal variations of precipitation and temperature during the study period (September 2011 to July 2012). The highest NO 3 − concentration in water was in May (wet season, mean ± SD = 17.45 ± 9.50 mg L −1 ) and the lowest concentration occurred in December (dry season, mean ± SD = 10.54 ± 6.28 mg L −1 ). Nevertheless, no water sample in the study area exceeds the WHO drinking water limit of 50 mg L −1 NO 3 − . Four sources of NO 3 − (atmospheric deposition, AD; soil N, SN; synthetic fertilizer, SF; manure and sewage, M and S) were identified using both hydrochemical characteristics [Cl − , NO 3 − , HCO 3 − , SO 4 2− , Ca 2+ , K + , Mg 2+ , Na + , dissolved oxygen (DO)] and dual isotope approach (δ 15 N–NO 3 − and δ 18 O–NO 3 − ). Both chemical and isotopic characteristics indicated that denitrification was not the main N cycling process in the study area. Using a Bayesian model (stable isotope analysis in R, SIAR), the contribution of each source was apportioned. Source apportionment results showed that source contributions differed significantly between the dry and wet season, AD and M and S contributed more in December than in May. In contrast, SN and SF contributed more NO 3 − to water in May than that in December. M and S and SF were the major contributors in December and May, respectively. Moreover, the shortcomings and uncertainties of SIAR were discussed to provide implications for future works. With the assessment of temporal variation and sources of NO 3 − , better agricultural management practices and sewage disposal programs can be implemented to sustain water quality in subtropical watersheds

Modeling nutrient sources, transport and management strategies in a coastal watershed, Southeast China.

Science.gov (United States)

Zhou, Pei; Huang, Jinliang; Hong, Huasheng

2018-01-01

Integrated watershed management requires an analytical model capable of revealing the full range of impacts that would be caused by the uses and developments in the watershed. The SPAtially Referenced Regressions On Watershed Attributes (SPARROW) model was developed in this study to provide empirical estimates of the sources, transport of total nitrogen (TN) and total phosphorus (TP) and to develop nutrient management strategies in the Jiulong River Watershed, southeast China that has enormous influence on the region's ecological safety. We calibrated the model using data related to daily streamflow, monthly TN and TP concentrations in 2014 at 30 locations. The model produced R 2 values for TN with 0.95 and TP with 0.94. It was found that for the entire watershed, TN came from fertilizer application (43%), livestock breeding (39%) and sewage discharge (18%), while TP came from livestock breeding (46%), fertilizer application (46%), and industrial discharge (8%). Fifty-eight percent of the TN and 80% of the TP in upstream reaches are delivered to the outlets of North and West rivers. A scenario analysis with SPARROW was coupled to develop suitable management strategies. Results revealed that controlling nutrient sources was effective in improving water quality. Normally sharp reduction in nutrient sources is not operational feasible. Hence, it is recommended that preventing nutrient on land from entering into the river as a suitable strategy in watershed management. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluating the Least Cost Selection of Agricultural Management Practices in the Five Mile Creek area of Fort Cobb Watershed, Oklahoma, USA

Science.gov (United States)

Rasoulzadeh Gharibdousti, S.; Stoecker, A.; Storm, D.

2017-12-01

One of the main causes of water quality impairment in the United States is human induced Non-Point Source (NPS) pollution through intensive agriculture. The Fort Cobb Reservoir (FCR) watershed located in west-central Oklahoma, United States is a rural agricultural catchment with known issues of NPS pollution including suspended solids, siltation, nutrients, and pesticides. Recently, several Best Management Practices (BMPs) have been implemented in the watershed (such as no-tillage and cropland to grassland conversion) to improve water quality. The objective in this study is to estimate the most cost effective selection and placement of BMPs on farmlands to mitigate soil erosion and the delivery of sediment and nutrient loads to the FCR from Five Mile Creek (FMC) area of the FCR watershed. We employed the Soil and Water Assessment Tool (SWAT) to develop the hydrological model of the study area. The watershed was delineated using the 10 m National Elevation Dataset and divided into 43 sub-basins with an average area of 8 km2. Through a combination of Soil Survey Geographic Database- SSURGO soil data, the US Department of Agriculture crop layer and the slope information, the watershed was further divided into 15,217 hydrologic response units (HRUs). The historical climate pattern in the watershed was represented by two different weather stations. The model was calibrated for the 1991 - 2000 period and validated over the 2001 - 2010 period against the monthly USGS observations of streamflow and suspended sediment concentration recorded at the watershed outlet. Model parametrization resulted in satisfactory values for the R2 (0.64, 0.35) and NS (0.61, 0.34) in calibration period and an excellent model performance (R2 = 0.79, 0.38; NS = 0.75, 0.43) in validation period for streamflow and sediment concentration respectively. We have selected 20 BMPs to estimate their efficacy in terms of water, sediment, and crop yields. Linear Programming (LP) was used to determine the

Landscape planning for agricultural nonpoint source pollution reduction III: Assessing phosphorus and sediment reduction potential

Science.gov (United States)

Diebel, M.W.; Maxted, J.T.; Robertson, Dale M.; Han, S.; Vander Zanden, M. J.

2009-01-01

Riparian buffers have the potential to improve stream water quality in agricultural landscapes. This potential may vary in response to landscape characteristics such as soils, topography, land use, and human activities, including legacies of historical land management. We built a predictive model to estimate the sediment and phosphorus load reduction that should be achievable following the implementation of riparian buffers; then we estimated load reduction potential for a set of 1598 watersheds (average 54 km2) in Wisconsin. Our results indicate that land cover is generally the most important driver of constituent loads in Wisconsin streams, but its influence varies among pollutants and according to the scale at which it is measured. Physiographic (drainage density) variation also influenced sediment and phosphorus loads. The effect of historical land use on present-day channel erosion and variation in soil texture are the most important sources of phosphorus and sediment that riparian buffers cannot attenuate. However, in most watersheds, a large proportion (approximately 70%) of these pollutants can be eliminated from streams with buffers. Cumulative frequency distributions of load reduction potential indicate that targeting pollution reduction in the highest 10% of Wisconsin watersheds would reduce total phosphorus and sediment loads in the entire state by approximately 20%. These results support our approach of geographically targeting nonpoint source pollution reduction at multiple scales, including the watershed scale. ?? 2008 Springer Science+Business Media, LLC.

Multiobjective Optimization Combining BMP Technology and Land Preservation for Watershed-based Stormwater Management

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McGarity, A. E.

2009-12-01

Recent progress has been made developing decision-support models for optimal deployment of best management practices (BMP’s) in an urban watershed to achieve water quality goals. One example is the high-level screening model StormWISE, developed by the author (McGarity, 2006) that uses linear and nonlinear programming to narrow the search for optimal solutions to certain land use categories and drainage zones. Another example is the model SUSTAIN developed by USEPA and Tetra Tech (Lai, et al., 2006), which builds on the work of Yu, et al., 2002), that uses a detailed, computationally intensive simulation model driven by a genetic solver to select optimal BMP sites. However, a model that deals only with best management practice (BMP) site selections may fail to consider solutions that avoid future nonpoint pollutant loadings by preserving undeveloped land. This paper presents results of a recently completed research project in which water resource engineers partnered with experienced professionals at a land conservation trust to develop a multiobjective model for watershed management. The result is a revised version of StormWISE that can be used to identify optimal, cost-effective combinations of easements and similar land preservation tools for undeveloped sites along with low impact development (LID) and BMP technologies for developed sites. The goal is to achieve the watershed-wide limits on runoff volume and pollutant loads that are necessary to meet water quality goals as well as ecological benefits associated with habitat preservation and enhancement. A nonlinear programming formulation is presented for the extended StormWISE model that achieves desired levels of environmental benefits at minimum cost. Tradeoffs between different environmental benefits are generated by multiple runs of the model while varying the levels of each environmental benefit obtained. The model is solved using piecewise linearization of environmental benefit functions where each

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

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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.

Modeled Watershed Runoff Associated with Variations in Precipitation Data with Implications for Contaminant Fluxes

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Watershed-scale fate and transport models are important tools for estimating the sources, transformation, and transport of contaminants to surface water systems. Precipitation is one of the primary inputs to watershed biogeochemical models, influencing changes in the water budge...

Analysis of sensitivity of simulated recharge to selected parameters for seven watersheds modeled using the precipitation-runoff modeling system

Science.gov (United States)

Ely, D. Matthew

2006-01-01

Recharge is a vital component of the ground-water budget and methods for estimating it range from extremely complex to relatively simple. The most commonly used techniques, however, are limited by the scale of application. One method that can be used to estimate ground-water recharge includes process-based models that compute distributed water budgets on a watershed scale. These models should be evaluated to determine which model parameters are the dominant controls in determining ground-water recharge. Seven existing watershed models from different humid regions of the United States were chosen to analyze the sensitivity of simulated recharge to model parameters. Parameter sensitivities were determined using a nonlinear regression computer program to generate a suite of diagnostic statistics. The statistics identify model parameters that have the greatest effect on simulated ground-water recharge and that compare and contrast the hydrologic system responses to those parameters. Simulated recharge in the Lost River and Big Creek watersheds in Washington State was sensitive to small changes in air temperature. The Hamden watershed model in west-central Minnesota was developed to investigate the relations that wetlands and other landscape features have with runoff processes. Excess soil moisture in the Hamden watershed simulation was preferentially routed to wetlands, instead of to the ground-water system, resulting in little sensitivity of any parameters to recharge. Simulated recharge in the North Fork Pheasant Branch watershed, Wisconsin, demonstrated the greatest sensitivity to parameters related to evapotranspiration. Three watersheds were simulated as part of the Model Parameter Estimation Experiment (MOPEX). Parameter sensitivities for the MOPEX watersheds, Amite River, Louisiana and Mississippi, English River, Iowa, and South Branch Potomac River, West Virginia, were similar and most sensitive to small changes in air temperature and a user-defined flow

Improving Baseline Model Assumptions: Evaluating the Impacts of Typical Methodological Approaches in Watershed Models

Science.gov (United States)

Muenich, R. L.; Kalcic, M. M.; Teshager, A. D.; Long, C. M.; Wang, Y. C.; Scavia, D.

2017-12-01

Thanks to the availability of open-source software, online tutorials, and advanced software capabilities, watershed modeling has expanded its user-base and applications significantly in the past thirty years. Even complicated models like the Soil and Water Assessment Tool (SWAT) are being used and documented in hundreds of peer-reviewed publications each year, and likely more applied in practice. These models can help improve our understanding of present, past, and future conditions, or analyze important "what-if" management scenarios. However, baseline data and methods are often adopted and applied without rigorous testing. In multiple collaborative projects, we have evaluated the influence of some of these common approaches on model results. Specifically, we examined impacts of baseline data and assumptions involved in manure application, combined sewer overflows, and climate data incorporation across multiple watersheds in the Western Lake Erie Basin. In these efforts, we seek to understand the impact of using typical modeling data and assumptions, versus using improved data and enhanced assumptions on model outcomes and thus ultimately, study conclusions. We provide guidance for modelers as they adopt and apply data and models for their specific study region. While it is difficult to quantitatively assess the full uncertainty surrounding model input data and assumptions, recognizing the impacts of model input choices is important when considering actions at the both the field and watershed scales.

Developing of Watershed Radionuclide Transport Model DHSVM-R as Modification and Extension of Distributed Hydrological and Sediment Dynamics Model DHSVM

Science.gov (United States)

Zheleznyak, M.; Kivva, S.; Onda, Y.; Nanba, K.; Wakiyama, Y.; Konoplev, A.

2015-12-01

The reliable modeling tools for prediction wash - off radionuclides from watersheds are needed as for assessment the consequences of accidental and industrial releases of radionuclides, as for soil erosion studies using the radioactive tracers. The distributed model of radionuclide transport through watershed in exchangeable and nonexchangeable forms in solute and with sediments was developed and validated for small Chernobyl watersheds in 90th within EU SPARTACUS project (van der Perk et al., 1996). New tendency is coupling of radionuclide transport models and the widely validated hydrological distributed models. To develop radionuclide transport model DHSVM-R the open source Distributed Hydrology Soil Vegetation Model -DHSVM http://www.hydro.washington.edu/Lettenmaier/Models/DHSVM was modified and extended. The main changes provided in the hydrological and sediment transport modules of DHSVM are as follows: Morel-Seytoux infiltration model is added; four-directions schematization for the model's cells flows (D4) is replaced by D8 approach; the finite-difference schemes for solution of kinematic wave equations for overland water flow, stream net flow, and sediment transport are replaced by new computationally efficient scheme. New radionuclide transport module, coupled with hydrological and sediment transport modules, continues SPARTACUS's approach, - it describes radionuclide wash-off from watershed and transport via stream network in soluble phase and on suspended sediments. The hydrological module of DHSVM-R was calibrated and validated for the watersheds of Ukrainian Carpathian mountains and for the subwatersheds of Niida river flowing 137Cs in solute and with suspended sediments to Pacific Ocean at 30 km north of the Fukushima Daiichi NPP. The modules of radionuclide and sediment transport were calibrated and validated versus experimental data for USLE experimental plots in Fukushima Prefecture and versus monitoring data collected in Niida watershed. The role

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

Science.gov (United States)

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.

Best Management Practices for sediment control in a Mediterranean agricultural watershed

Science.gov (United States)

Abdelwahab, Ossama M. M.; Bingner, Ronald L.; Milillo, Fabio; Gentile, Francesco

2015-04-01

Soil erosion can lead to severe destruction of agricultural sustainability that affects not only productivity, but the entire ecosystem in the neighboring areas. Sediments transported together with the associated nutrients and chemicals can significantly impact downstream water bodies. Various conservation and management practices implemented individually or integrated together as a system can be used to reduce the negative impacts on agricultural watersheds from soil erosion. Hydrological models are useful tools for decision makers when selecting the most effective combination of management practices to reduce pollutant loads within a watershed system. The Annualized Agricultural Non-point Source (AnnAGNPS) pollutant loading management model can be used to analyze the effectiveness of diverse management and conservation practices that can control or reduce the impact of soil erosion processes and subsequent sediment loads in agricultural watersheds. A 506 km2 Mediterranean medium-size watershed (Carapelle) located in Apulia, Southern Italy was used as a case study to evaluate the model and best management practices (BMPs) for sediment load control. A monitoring station located at the Ordona bridge has been instrumented to continuously monitor stream flow and suspended sediment loads. The station has been equipped with an ultrasound stage meter and a stage recorder to monitor stream flow. An infrared optic probe was used to measure suspended sediment concentrations (Gentile et al., 2010 ). The model was calibrated and validated in the Carapelle watershed on an event basis (Bisantino et al., 2013), and the validated model was used to evaluate the effectiveness of BMPs on sediment reduction. Various management practices were investigated including evaluating the impact on sediment load of: (1) converting all cropland areas into forest and grass covered conditions; (2) converting the highest eroding cropland areas to forest or grass covered conditions; and (3

Distributed models of radionuclide transport on watersheds: development and implementation for the Chernobyl and Fukushima catchments

Energy Technology Data Exchange (ETDEWEB)

Kivva, S.; Zheleznyak, M. [Institute of Environmental Radioactivity, Fukushima University (Japan)

2014-07-01

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 radionuclide transport watershed models. Two distributed watershed models of radionuclide transport - RUNTOX and DHSVM-R have been used to simulate the radionuclide transport in the basin of the Dnieper River, Ukraine and watersheds of Prefecture Fukushima. RUNTOX is used for the simulation of radionuclide wash off from the experimental plots and small watersheds, and DHSVM-R is used for medium and large watersheds RUNTOX is two dimensional distributed hydrological model based on the finite-difference solution of the coupled equations the surface flow, subsurface flow, groundwater flow and advection- dispersion equations of the sediments (eroded soil) and radionuclide transport in liquid and solid phases, taking into parameterize the radionuclide exchanges between liquid and solid phases.. This model has been applied to the experimental plots in Ukraine after the Chernobyl accident and experimental plots in the Fukushima Prefecture. The experience of RUNTOX development and application has been used for the extension of the distributed hydrological model DHSVM by the including of the module of the watershed radionuclide transport. The updated model was named by DHSMV-R. The original DHSVM (Distributed Hydrology Soil Vegetation Model) was developed in the University of Washington and Pacific Northwest National Laboratories. DHSVM is a physical distributed hydrology-vegetation model for complex terrain based on the numerical solution of the network of one dimensional equations. The model accounts explicitly for the spatial distribution of land-surface processes, and can be applied over a range of scales, from plot to large

Integration of aspect and slope in snowmelt runoff modeling in a mountain watershed

Directory of Open Access Journals (Sweden)

Shalamu Abudu

2016-10-01

Full Text Available This study assessed the performances of the traditional temperature-index snowmelt runoff model (SRM and an SRM model with a finer zonation based on aspect and slope (SRM + AS model in a data-scarce mountain watershed in the Urumqi River Basin, in Northwest China. The proposed SRM + AS model was used to estimate the melt rate with the degree-day factor (DDF through the division of watershed elevation zones based on aspect and slope. The simulation results of the SRM + AS model were compared with those of the traditional SRM model to identify the improvements of the SRM + AS model's performance with consideration of topographic features of the watershed. The results show that the performance of the SRM + AS model has improved slightly compared to that of the SRM model. The coefficients of determination increased from 0.73, 0.69, and 0.79 with the SRM model to 0.76, 0.76, and 0.81 with the SRM + AS model during the simulation and validation periods in 2005, 2006, and 2007, respectively. The proposed SRM + AS model that considers aspect and slope can improve the accuracy of snowmelt runoff simulation compared to the traditional SRM model in mountain watersheds in arid regions by proper parameterization, careful input data selection, and data preparation.

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.

Science.gov (United States)

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.

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

Science.gov (United States)

Future shifts in climatic conditions may impact watershed mercury (Hg) dynamics and transport. We apply an ensemble of watershed models to simulate and assess the responses of hydrological and total Hg (HgT) fluxes and concentrations to two climate change projections in the US Co...

Assessment of soil erosion risk in Komering watershed, South Sumatera, using SWAT model

Science.gov (United States)

Salsabilla, A.; Kusratmoko, E.

2017-07-01

Changes in land use watershed led to environmental degradation. Estimated loss of soil erosion is often difficult due to some factors such as topography, land use, climate and human activities. This study aims to predict soil erosion hazard and sediment yield using the Soil and Water Assessment Tools (SWAT) hydrological model. The SWAT was chosen because it can simulate the model with limited data. The study area is Komering watershed (806,001 Ha) in South Sumatera Province. There are two factors land management intervention: 1) land with agriculture, and 2) land with cultivation. These factors selected in accordance with the regulations of spatial plan area. Application of the SWAT demonstrated that the model can predict surface runoff, soil erosion loss and sediment yield. The erosion risk for each watershed can be classified and predicted its changes based on the scenarios which arranged. In this paper, we also discussed the relationship between the distribution of erosion risk and watershed's characteristics in a spatial perspective.

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

Science.gov (United States)

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.

Calibration and validation of SWAT model for estimating water balance and nitrogen losses in a small agricultural watershed in central Poland

Directory of Open Access Journals (Sweden)

Smarzyńska Karolina

2016-06-01

Full Text Available Soil and Water Assessment Tool (SWAT ver. 2005 was applied to study water balance and nitrogen load pathways in a small agricultural watershed in the lowlands of central Poland. The natural flow regime of the Zgłowiączka River was strongly modified by human activity (deforestation and installation of a subsurface drainage system to facilitate stable crop production. SWAT was calibrated for daily and monthly discharge and monthly nitrate nitrogen load. Model efficiency was tested using manual techniques (subjective and evaluation statistics (objective. Values of Nash–Sutcliffe efficiency coefficient (NSE, coefficient of determination (R2 and percentage of bias for daily/monthly discharge simulations and monthly load indicated good or very good fit of simulated discharge and nitrate nitrogen load to the observed data set. Model precision and accuracy of fit was proved in validation. The calibrated and validated SWAT was used to assess water balance and nitrogen fluxes in the watershed. According to the results, the share of tile drainage in water yield is equal to 78%. The model analysis indicated the most significant pathway of NO3-N to surface waters in the study area, namely the tile drainage combined with lateral flow. Its share in total NO3-N load amounted to 89%. Identification of nitrogen fluxes in the watershed is crucial for decision makers in order to manage water resources and to implement the most effective measures to limit diffuse pollution from arable land to surface waters.

Comparison of computer models for estimating hydrology and water quality in an agricultural watershed

Science.gov (United States)

Various computer models, ranging from simple to complex, have been developed to simulate hydrology and water quality from field to watershed scales. However, many users are uncertain about which model to choose when estimating water quantity and quality conditions in a watershed. This study compared...

Climate Change Impacts on Nutrient Losses of Two Watersheds in the Great Lakes Region

Directory of Open Access Journals (Sweden)

Lili Wang

2018-04-01

Full Text Available Non-point sources (NPS of agricultural chemical pollution are one major reason for the water quality degradation of the Great Lakes, which impacts millions of residents in the states and provinces that are bordering them. Future climate change will further impact water quality in both direct and indirect ways by influencing the hydrological cycle and processes of nutrient transportation and transformation, but studies are still rare. This study focuses on quantifying the impacts of climate change on nutrient (Nitrogen and Phosphorus losses from the two small watersheds (Walworth watershed and Green Lake watershed within the Great Lakes region. Analysis focused on changes through this century (comparing the nutrient loss prediction of three future periods from 2015 to 2099 with 30 years for each period against the historical nutrient estimation data from 1985 to 2008. The effects on total phosphorus and nitrate-nitrogen losses due to changes in precipitation quantity, intensity, and frequency, as well as air temperature, are evaluated for the two small watersheds, under three special report emission scenarios (SRES A2, A1B, B1. The newly developed Water Erosion Prediction Project-Water Quality (WEPP-WQ model is utilized to simulate nutrient losses with downscaled and bias corrected future climate forcing from two General Circulation Models (GFDL, HadCM3. For each watershed, the observed runoff and nutrient loads are used to calibrate and validate the model before the application of the WEPP-WQ model to examine potential impacts from future climate change. Total phosphorus loss is projected to increase by 28% to 89% for the Green Lake watershed and 25% to 108% for the Walworth watershed mainly due to the combined effects of increase of precipitation quantity, extreme storm events in intensity and frequency, and air temperature. Nitrate-nitrogen losses are projected to increase by 1.1% to 38% for the Green Lake watershed and 8% to 95% for the

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

Science.gov (United States)

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.

A Workflow to Model Microbial Loadings in Watersheds

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Many watershed models simulate overland and instream microbial fate and transport, but few actually provide loading rates on land surfaces and point sources to the water body network. This paper describes the underlying general equations for microbial loading rates associated wit...

Distribution and source analysis of heavy metal pollutants in sediments of a rapid developing urban river system.

Science.gov (United States)

Xia, Fang; Qu, Liyin; Wang, Ting; Luo, Lili; Chen, Han; Dahlgren, Randy A; Zhang, Minghua; Mei, Kun; Huang, Hong

2018-09-01

Heavy metal pollution of aquatic environments in rapidly developing industrial regions is of considerable global concern due to its potential to cause serious harm to aquatic ecosystems and human health. This study assessed heavy metal contamination of sediments in a highly industrialized urban watershed of eastern China containing several historically unregulated manufacturing enterprises. Total concentrations and solid-phase fractionation of Cu, Zn, Pb, Cr and Cd were investigated for 39 river sediments using multivariate statistical analysis and geographically weighted regression (GWR) methods to quantitatively examine the relationship between land use and heavy metal pollution at the watershed scale. Results showed distinct spatial patterns of heavy metal contamination within the watershed, such as higher concentrations of Zn, Pb and Cd in the southwest and higher Cu concentration in the east, indicating links to specific pollution sources within the watershed. Correlation and PCA analyses revealed that Zn, Pb and Cd were dominantly contributed by anthropogenic activities; Cu originated from both industrial and agricultural sources; and Cr has been altered by recent pollution control strategies. The GWR model indicated that several heavy metal fractions were strongly correlated with industrial land proportion and this correlation varied with the level of industrialization as demonstrated by variations in local GWR R 2 values. This study provides important information for assessing heavy metal contaminated areas, identifying heavy metal pollutant sources, and developing regional-scale remediation strategies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Modeling the potential role of a forest ecosystem in phytostabilization and phytoextraction of 90Sr at a contaminated watershed

International Nuclear Information System (INIS)

Garten, C.T. Jr.

1999-01-01

The behavior of 90 Sr at forest sites in the White Oak Creek watershed, near Oak Ridge, Tennessee, was simulated with a simple, site-specific, multicompartment model that linked biomass and element cycling dynamics. The model was used to predict the role of forest cover in mitigating hydrologic losses of 90 Sr from contaminated soils (i.e. phytostabilization) under conditions where contaminant transport is governed mainly by shallow subsurface flow. The model was also used to predict the removal of 90 Sr from soil (i.e. phytoextraction) through the growth and harvest of short rotation woody crops over a period of 30 years. Simulations with the model indicated that (1) forest preservation on the watershed is a form of phytostabilization because forest cover helps to minimize hydrologic losses of 90 Sr and (2) an attempt to significantly reduce amounts of 90 Sr in soil through phytoextraction would be unsuccessful. Over a period of 30 years, and under various management strategies, the model predicted that 90 Sr initially present in soil at a contaminated site was lost through hydrologic transport and <53% was lost by radioactive decay. Phytostabilization may be important in the management of radioactive land when issues like waste minimization and pollution prevention affect the selection of technologies to be used in environmental restoration. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Hydrologic and atrazine simulation of the Cedar Creek Watershed using the SWAT model.

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Larose, M; Heathman, G C; Norton, L D; Engel, B

2007-01-01

One of the major factors contributing to surface water contamination in agricultural areas is the use of pesticides. The Soil and Water Assessment Tool (SWAT) is a hydrologic model capable of simulating the fate and transport of pesticides in an agricultural watershed. The SWAT model was used in this study to estimate stream flow and atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) losses to surface water in the Cedar Creek Watershed (CCW) within the St. Joseph River Basin in northeastern Indiana. Model calibration and validation periods consisted of five and two year periods, respectively. The National Agricultural Statistics Survey (NASS) 2001 land cover classification and the Soil Survey Geographic (SSURGO) database were used as model input data layers. Data from the St. Joseph River Watershed Initiative and the Soil and Water Conservation Districts of Allen, Dekalb, and Noble counties were used to represent agricultural practices in the watershed which included the type of crops grown, tillage practices, fertilizer, and pesticide application rates. Model results were evaluated based on efficiency coefficient values, standard statistical measures, and visual inspection of the measured and simulated hydrographs. The Nash and Sutcliffe model efficiency coefficients (E(NS)) for monthly and daily stream flow calibration and validation ranged from 0.51 to 0.66. The E(NS) values for atrazine calibration and validation ranged from 0.43 to 0.59. All E(NS) values were within the range of acceptable model performance standards. The results of this study indicate that the model is an effective tool in capturing the dynamics of stream flow and atrazine concentrations on a large-scale agricultural watershed in the midwestern USA.

Hydromentor: An integrated water resources monitoring and management system at modified semi-arid watersheds

Science.gov (United States)

Vasiliades, Lampros; Sidiropoulos, Pantelis; Tzabiras, John; Kokkinos, Konstantinos; Spiliotopoulos, Marios; Papaioannou, George; Fafoutis, Chrysostomos; Michailidou, Kalliopi; Tziatzios, George; Loukas, Athanasios; Mylopoulos, Nikitas

2015-04-01

Natural and engineered water systems interact throughout watersheds and while there is clearly a link between watershed activities and the quantity and quality of water entering the engineered environment, these systems are considered distinct operational systems. As a result, the strategic approach to data management and modeling within the two systems is very different, leading to significant difficulties in integrating the two systems in order to make comprehensive watershed decisions. In this paper, we describe the "HYDROMENTOR" research project, a highly-structured data storage and exchange system that integrates multiple tools and models describing both natural and modified environments, to provide an integrated tool for management of water resources. Our underlying objective in presenting our conceptual design for this water information system is to develop an integrated and automated system that will achieve monitoring and management of the water quantity and quality at watershed level for both surface water (rivers and lakes) and ground water resources (aquifers). The uniqueness of the system is the integrated treatment of the water resources management issue in terms of water quantity and quality in current climate conditions and in future conditions of climatic change. On an operational level, the system provides automated warnings when the availability, use and pollution levels exceed allowable limits pre-set by the management authorities. Decision making with respect to the apportionment of water use by surface and ground water resources are aided through this system, while the relationship between the polluting activity of a source to total incoming pollution by sources are determined; this way, the best management practices for dealing with a crisis are proposed. The computational system allows the development and application of actions, interventions and policies (alternative management scenarios) so that the impacts of climate change in quantity

Combination Use of Water Quality Modelling and Cost-Effective Analysis to Assess Environmental Benefit of a Watershed - A Case Study of Various Engineering and Management Strategy Arrangements in Taiwan

Science.gov (United States)

Fan, C.; Wu, C. Y.

2017-12-01

This study aimed to evaluate the potential environmental benefits using the water quality modelling integrated with cost-effective analysis to assess several proposed scenarios of engineering and management arrangements based on regional development planning and pollution mitigation strategy. The QUAL2Kw models of Erhjen river and its major tributary, Sanye creek, were established to simulate the river pollution indices of dissolved oxygen (DO), biochemical oxygen demand (BOD), suspended solids (SS) and ammonia nitrogen (NH3-N). The HEC-RAS was employed to calculate the hydraulic parameters and dilution impact of tidal effect in the downstream section. The verified integrated model was applied to estimating the water quality variations for several given scenarios considering the possible re-arrangement of projected pollution mitigation implementations, such as sewage system construction facilitation, additional on-site treatment facilities establishment and pig-manure anaerobic fermentation for biogas power generation in the Erhjen river watershed. As a result, the water quality of the Sanye creek was apparently improved after the completion of sewage system construction. The ammonia nitrogen concentration reduced from the level 6 to 10 times above severely-polluted standard to the merely-above level. By ignoring the impact of ammonia nitrogen on river pollution index calculation, the water quality of the lower section of the Sanye creek was improved to slightly-polluted or non-polluted level. In the scenario of anaerobic fermentation promotion, if manure anaerobic fermentation facilities were installed in all the pig farms with livestock number more than 2000, water quality was estimated to be improved slightly only. Furthermore, if all the manure waste from pig-farms is collected for subsequent electricity generation in the investigated watershed, the river pollution index is estimated to improve to moderately-polluted category for all the length of Erhjen river

Economic Tools for Managing Nitrogen in Coastal Watersheds ...

Science.gov (United States)

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

Water environmental planning and management at the watershed scale:A case study of Lake Qilu,China

Institute of Scientific and Technical Information of China (English)

2008-01-01

Water environmental planning and management has become essential for guiding the water pollution control activities.Past water pollution control activities have been site specific,with little thought on water quality standard reaching at the watershed scale.Based on the watershed approach,a seven-step methodological framework for water environmental planning and management was developed.The framework was applied to water environmental planning and management of the Lake Qilu watershed in Yunnan Province,China.Results show that the reduction amount of total nitrogen (TN) under the plan is 1,205 tons per year so that the target of environmental capacity can be reached in 2020.Compared with traditional methods,the framework has its prevalence and could be generalized to analogous watersheds.

Engaging Watershed Stakeholders for Cost-Effective Environmental Management Planning with "Watershed Manager"

Science.gov (United States)

Williams, Jeffery R.; Smith, Craig M.; Roe, Josh D.; Leatherman, John C.; Wilson, Robert M.

2012-01-01

"Watershed Manager" is a spreadsheet-based model that is used in extension education programs for learning about and selecting cost-effective watershed management practices to reduce soil, nitrogen, and phosphorus losses from cropland. It can facilitate Watershed Restoration and Protection Strategy (WRAPS) stakeholder groups' development…

Asotin Creek model watershed plan: Asotin County, Washington

International Nuclear Information System (INIS)

1995-01-01

The Northwest Power Planning Council completed its ''Strategy for Salmon'' in 1992. This is a plan, composed of four specific elements,designed to double the present production of 2.5 million salmon in the Columbia River watershed. These elements have been called the ''four H's'': (1) improve harvest management; (2) improve hatcheries and their production practices; (3) improve survival at hydroelectric dams; and (4) improve and protect fish habitat. The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ''Strategy for Salmon''. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity

Integrating topography, hydrology and rock structure in weathering rate models of spring watersheds

NARCIS (Netherlands)

Pacheco, F.A.L.; Weijden, C.H. van der

2012-01-01

Weathering rate models designed for watersheds combine chemical data of discharging waters with morphologic and hydrologic parameters of the catchments. At the spring watershed scale, evaluation of morphologic parameters is subjective due to difficulties in conceiving the catchment geometry.

Improved daily precipitation nitrate and ammonium concentration models for the Chesapeake Bay Watershed

International Nuclear Information System (INIS)

Grimm, J.W.; Lynch, J.A.

2005-01-01

Daily precipitation nitrate and ammonium concentration models were developed for the Chesapeake Bay Watershed (USA) using a linear least-squares regression approach and precipitation chemistry data from 29 National Atmospheric Deposition Program/National Trends Network (NADP/NTN) sites. Only weekly samples that comprised a single precipitation event were used in model development. The most significant variables in both ammonium and nitrate models included: precipitation volume, the number of days since the last event, a measure of seasonality, latitude, and the proportion of land within 8 km covered by forest or devoted to industry and transportation. Additional variables included in the nitrate model were the proportion of land within 0.8 km covered by water and/or forest. Local and regional ammonia and nitrogen oxide emissions were not as well correlated as land cover. Modeled concentrations compared very well with event chemistry data collected at six NADP/AirMoN sites within the Chesapeake Bay Watershed. Wet deposition estimates were also consistent with observed deposition at selected sites. Accurately describing the spatial distribution of precipitation volume throughout the watershed is important in providing critical estimates of wet-fall deposition of ammonium and nitrate. - A linear least-squares regression approach was used to develop daily precipitation nitrate and ammonium concentration models for the Chesapeake Bay Watershed

Watershed regressions for pesticides (warp) models for predicting atrazine concentrations in Corn Belt streams

Science.gov (United States)

Stone, Wesley W.; Gilliom, Robert J.

2012-01-01

Watershed Regressions for Pesticides (WARP) models, previously developed for atrazine at the national scale, are improved for application to the United States (U.S.) Corn Belt region by developing region-specific models that include watershed characteristics that are influential in predicting atrazine concentration statistics within the Corn Belt. WARP models for the Corn Belt (WARP-CB) were developed for annual maximum moving-average (14-, 21-, 30-, 60-, and 90-day durations) and annual 95th-percentile atrazine concentrations in streams of the Corn Belt region. The WARP-CB models accounted for 53 to 62% of the variability in the various concentration statistics among the model-development sites. Model predictions were within a factor of 5 of the observed concentration statistic for over 90% of the model-development sites. The WARP-CB residuals and uncertainty are lower than those of the National WARP model for the same sites. Although atrazine-use intensity is the most important explanatory variable in the National WARP models, it is not a significant variable in the WARP-CB models. The WARP-CB models provide improved predictions for Corn Belt streams draining watersheds with atrazine-use intensities of 17 kg/km2 of watershed area or greater.

Development of a Watershed-Scale Long-Term Hydrologic Impact Assessment Model with the Asymptotic Curve Number Regression Equation

Directory of Open Access Journals (Sweden)

Jichul Ryu

2016-04-01

Full Text Available In this study, 52 asymptotic Curve Number (CN regression equations were developed for combinations of representative land covers and hydrologic soil groups. In addition, to overcome the limitations of the original Long-term Hydrologic Impact Assessment (L-THIA model when it is applied to larger watersheds, a watershed-scale L-THIA Asymptotic CN (ACN regression equation model (watershed-scale L-THIA ACN model was developed by integrating the asymptotic CN regressions and various modules for direct runoff/baseflow/channel routing. The watershed-scale L-THIA ACN model was applied to four watersheds in South Korea to evaluate the accuracy of its streamflow prediction. The coefficient of determination (R2 and Nash–Sutcliffe Efficiency (NSE values for observed versus simulated streamflows over intervals of eight days were greater than 0.6 for all four of the watersheds. The watershed-scale L-THIA ACN model, including the asymptotic CN regression equation method, can simulate long-term streamflow sufficiently well with the ten parameters that have been added for the characterization of streamflow.

Risk Assessment of Nitrogen and Phosphorus Loss in a Hilly-Plain Watershed Based on the Different Hydrological Period: A Case Study in Tiaoxi Watershed

Directory of Open Access Journals (Sweden)

Hongmeng Ye

2017-08-01

Full Text Available Non-point source pollution is widely considered a serious threat to drinking water. Eutrophication in Chinese watershed is mainly due to nitrogen and phosphorus output from agricultural source. Taihu Lake is a typical eutrophic lake in China, a basin representative for the study of the temporal-spatial characteristics of pollution loading of nitrogen and phosphorus to provide scientific basis for reasonable estimation and targeted control measures of nitrogen and phosphorus loss. Based on data from nitrogen and phosphorus loss in agricultural land, livestock breeding, domestic discharge and aquaculture, this study calculated the levels of nitrogen and phosphorus comprehensive loss risk for each pollution source. Using the superposition of ArcGIS raster data, we also described the spatial distribution of nitrogen and phosphorus comprehensive loss risk by the formula of comprehensive loss risk. The results showed that critical risk areas of nitrogen and phosphorus loss mainly originated from livestock breeding and agricultural land during flood period in Tiaoxi watershed. Agricultural land and livestock breeding sources formed major parts of nitrogen loss, accounting for 30.85% and 36.18%, respectively, while phosphorus loss mainly originated from livestock breeding (56.28%. During non-flood period, integrated management of livestock breeding and domestic discharge requires much attention to control nitrogen and phosphorus loss in the critical risk area. Finally, it is of great practical significance to propose spatial-temporal targeted measurements to control nitrogen and phosphorus pollution in watershed for various periods and different areas.

Modeling the relationship between landscape characteristics and water quality in a typical highly intensive agricultural small watershed, Dongting lake basin, south central China.

Science.gov (United States)

Li, Hongqing; Liu, Liming; Ji, Xiang

2015-03-01

Understanding the relationship between landscape characteristics and water quality is critically important for estimating pollution potential and reducing pollution risk. Therefore, this study examines the relationship between landscape characteristics and water quality at both spatial and temporal scales. The study took place in the Jinjing River watershed in 2010; seven landscape types and four water quality pollutions were chosen as analysis parameters. Three different buffer areas along the river were drawn to analyze the relationship as a function of spatial scale. The results of a Pearson's correlation coefficient analysis suggest that "source" landscape, namely, tea gardens, residential areas, and paddy lands, have positive effects on water quality parameters, while forests exhibit a negative influence on water quality parameters because they represent a "sink" landscape and the sub-watershed level is identified as a suitable scale. Using the principal component analysis, tea gardens, residential areas, paddy lands, and forests were identified as the main landscape index. A stepwise multiple regression analysis was employed to model the relationship between landscape characteristics and water quality for each season. The results demonstrate that both landscape composition and configuration affect water quality. In summer and winter, the landscape metrics explained approximately 80.7 % of the variance in the water quality variables, which was higher than that for spring and fall (60.3 %). This study can help environmental managers to understand the relationships between landscapes and water quality and provide landscape ecological approaches for water quality control and land use management.

Agricultural non-point source pollution management in a reservoir watershed based on ecological network analysis of soil nitrogen cycling.

Science.gov (United States)

Xu, Wen; Cai, Yanpeng; Rong, Qiangqiang; Yang, Zhifeng; Li, Chunhui; Wang, Xuan

2018-03-01

The Miyun Reservoir plays a pivotal role in providing drinking water for the city of Beijing. In this research, ecological network analysis and scenario analysis were integrated to explore soil nitrogen cycling of chestnut and Chinese pine forests in the upper basin of the Miyun Reservoir, as well as to seek favorable fertilization modes to reduce agricultural non-point source pollution. Ecological network analysis results showed that (1) the turnover time was 0.04 to 0.37 year in the NH 4 + compartment and were 15.78 to 138.36 years in the organic N compartment; (2) the Finn cycling index and the ratio of indirect to direct flow were 0.73 and 11.92 for the chestnut forest model, respectively. Those of the Chinese pine forest model were 0.88 and 29.23, respectively; and (3) in the chestnut forest model, NO 3 - accounted for 96% of the total soil nitrogen loss, followed by plant N (2%), NH 4 + (1%), and organic N (1%). In the Chinese pine forest, NH 4 + accounted for 56% of the total soil nitrogen loss, followed by organic N (34%) and NO 3 - (10%). Fertilization mode was identified as the main factor affecting soil N export. To minimize NH 4 + and NO 3 - outputs while maintaining the current plant yield (i.e., 7.85e0 kg N/year), a fertilization mode of 162.50 kg N/year offered by manure should be adopted. Whereas, to achieve a maximum plant yield (i.e., 3.35e1 kg N/year) while reducing NH 4 + and NO 3 - outputs, a fertilization mode of 325.00 kg N/year offered by manure should be utilized. This research is of wide suitability to support agricultural non-point source pollution management at the watershed scale.

Runoff and sediment yield model for predicting nuclide transport in watersheds using BIOTRAN

Energy Technology Data Exchange (ETDEWEB)

Gallegos, A.F.; Wenzel, W.J.

1990-09-01

The environmental risk simulation model BIOTRAN was interfaced with a series of new subroutines (RUNOFF, GEOFLX, EROSON, and AQUIFER) to predict the movement of nuclides, elements, and pertinent chemical compounds in association with sediments through lateral and channel flow of runoff water. In addition, the movement of water into and out of segmented portions of runoff channels was modeled to simulate the dynamics of moisture flow through specified aquifers within the watershed. The BIOTRAN soil water flux subroutine, WATFLX, was modified to interface the relationships found in the SPUR model for runoff and sediment transport into channels with the particle sorting relationships to predict radionuclide enrichment and movement in watersheds. The new subroutines were applied specifically to Mortandad Canyon within Los Alamos National Laboratory by simultaneous simulation of eight surface vegetational subdivisions and associated channel and aquifer segments of this watershed. This report focuses on descriptions of the construction and rationale for the new subroutines and on discussing both input characteristics and output relationships to known runoff events from Mortandad Canyon. Limitations of the simplified input on model behavior are also discussed. Uranium-238 was selected as the nuclide for demonstration of the model because it could be assumed to be homogeneously distributed over the watershed surface. 22 refs., 18 figs., 9 tabs.

Fertilizer Induced Nitrate Pollution in RCW: Calibration of the DNDC Model

Science.gov (United States)

El Hailouch, E.; Hornberger, G.; Crane, J. W.

2012-12-01

Fertilizer is widely used among urban and suburban households due to the socially driven attention of homeowners to lawn appearance. With high nitrogen content, fertilizer considerably impacts the environment through the emission of the highly potent greenhouse gas nitrous oxide and the leaching of nitrate. Nitrate leaching is significantly important because fertilizer sourced nitrate that is partially leached into soil causes groundwater pollution. In an effort to model the effect of fertilizer application on the environment, the geochemical DeNitrification-DeComposition model (DNDC) was previously developed to quantitatively measure the effects of fertilizer use. The purpose of this study is to use this model more effectively on a large scale through a measurement based calibration. For this reason, leaching was measured and studied on 12 sites in the Richland Creek Watershed (RCW). Information about the fertilization and irrigation regimes of these sites was collected, along with lysimeter readings that gave nitrate fluxes in the soil. A study of the amount and variation in nitrate leaching with respect to the varying geographical locations, time of the year, and fertilization and irrigation regimes has lead to a better understanding of the driving forces behind nitrate leaching. Quantifying the influence of each of these parameters allows for a more accurate calibration of the model thus permitting use that extends beyond the RCW. Measurement of nitrate leaching on a statewide or nationwide level in turn will help guide efforts in the reduction of groundwater pollution caused by fertilizer.

Chloride Sources and Losses in Two Tile-Drained Agricultural Watersheds.

Science.gov (United States)

David, Mark B; Mitchell, Corey A; Gentry, Lowell E; Salemme, Ronald K

2016-01-01

Chloride is a relatively unreactive plant nutrient that has long been used as a biogeochemical tracer but also can be a pollutant causing aquatic biology impacts when concentrations are high, typically from rock salt applications used for deicing roads. Chloride inputs to watersheds are most often from atmospheric deposition, road salt, or agricultural fertilizer, although studies on agricultural watersheds with large fertilizer inputs are few. We used long-term (21 and 17 yr) chloride water quality data in two rivers of east-central Illinois to better understand chloride biogeochemistry in two agricultural watersheds (Embarras and Kaskaskia), the former with a larger urban land use and both with extensive tile drainage. During our sampling period, the average chloride concentration was 23.7 and 20.9 mg L in the Embarras and Kaskaskia Rivers, respectively. Annual fluxes of chloride were 72.5 and 61.2 kg ha yr in the Embarras and Kaskaskia watersheds, respectively. In both watersheds, fertilizer chloride was the dominant input (∼49 kg ha yr), with road salt likely the other major source (23.2 and 7.2 kg ha yr for the Embarras and Kaskaskia watersheds, respectively). Combining our monitoring data with earlier published data on the Embarras River showed an increase in chloride concentrations as potash use increased in Illinois during the 1960s and 1970s with a lag of about 2 to 6 yr to changes in potash inputs based on a multiple-regression model. In these agricultural watersheds, riverine chloride responds relatively quickly to potash fertilization as a result of tile-drainage. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Development of multi-year land cover data to assess wildfire impacts to coastal watersheds and the nearshore environment

Science.gov (United States)

Morrison, Katherine D.

In the Mediterranean ecosystems of coastal California, wildfire is a common disturbance that can significantly alter vegetation in watersheds that transport sediment and nutrients to the adjacent nearshore oceanic environment. We assess the impact of two wildfires that burned in 2008 on land cover and to the nearshore environment along the Big Sur coast in central California. We created a multi-year land cover dataset to assess changes to coastal watersheds as a result of fire. This land cover dataset was then used to model changes in nonpoint source pollutants transported to the nearshore environment. Results indicate post-fire increases in percent export compared to pre-fire years and also link wildfire severity to the specific land cover changes that subsequently increase exports of pollutants and sediment to the nearshore environment. This approach is a replicable across watersheds and also provides a framework for including the nearshore environment as a value at risk terrestrial land management revolving around wildfire, including suppression, thinning, and other activities that change land cover at a landscape scale.

Nitrate source apportionment in a subtropical watershed using Bayesian model

Energy Technology Data Exchange (ETDEWEB)

Yang, Liping; Han, Jiangpei; Xue, Jianlong; Zeng, Lingzao [College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058 (China); Shi, Jiachun, E-mail: jcshi@zju.edu.cn [College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058 (China); Wu, Laosheng, E-mail: laowu@zju.edu.cn [College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058 (China); Jiang, Yonghai [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012 (China)

2013-10-01

Nitrate (NO{sub 3}{sup −}) pollution in aquatic system is a worldwide problem. The temporal distribution pattern and sources of nitrate are of great concern for water quality. The nitrogen (N) cycling processes in a subtropical watershed located in Changxing County, Zhejiang Province, China were greatly influenced by the temporal variations of precipitation and temperature during the study period (September 2011 to July 2012). The highest NO{sub 3}{sup −} concentration in water was in May (wet season, mean ± SD = 17.45 ± 9.50 mg L{sup −1}) and the lowest concentration occurred in December (dry season, mean ± SD = 10.54 ± 6.28 mg L{sup −1}). Nevertheless, no water sample in the study area exceeds the WHO drinking water limit of 50 mg L{sup −1} NO{sub 3}{sup −}. Four sources of NO{sub 3}{sup −} (atmospheric deposition, AD; soil N, SN; synthetic fertilizer, SF; manure and sewage, M and S) were identified using both hydrochemical characteristics [Cl{sup −}, NO{sub 3}{sup −}, HCO{sub 3}{sup −}, SO{sub 4}{sup 2−}, Ca{sup 2+}, K{sup +}, Mg{sup 2+}, Na{sup +}, dissolved oxygen (DO)] and dual isotope approach (δ{sup 15}N–NO{sub 3}{sup −} and δ{sup 18}O–NO{sub 3}{sup −}). Both chemical and isotopic characteristics indicated that denitrification was not the main N cycling process in the study area. Using a Bayesian model (stable isotope analysis in R, SIAR), the contribution of each source was apportioned. Source apportionment results showed that source contributions differed significantly between the dry and wet season, AD and M and S contributed more in December than in May. In contrast, SN and SF contributed more NO{sub 3}{sup −} to water in May than that in December. M and S and SF were the major contributors in December and May, respectively. Moreover, the shortcomings and uncertainties of SIAR were discussed to provide implications for future works. With the assessment of temporal variation and sources of NO{sub 3}{sup −}, better

Green Infrastructure and Watershed-Scale Hydrology in a Mixed Land Cover System

Science.gov (United States)

Hoghooghi, N.; Golden, H. E.; Bledsoe, B. P.

2017-12-01

Urbanization results in replacement of pervious areas (e.g., vegetation, topsoil) with impervious surfaces such as roads, roofs, and parking lots, which cause reductions in interception, evapotranspiration, and infiltration, and increases in surface runoff (overland flow) and pollutant loads and concentrations. Research on the effectiveness of different Green Infrastructure (GI), or Low Impact Development (LID), practices to reduce these negative impacts on stream flow and water quality has been mostly focused at the local scale (e.g., plots, small catchments). However, limited research has considered the broader-scale effects of LID, such as how LID practices influence water quantity, nutrient removal, and aquatic ecosystems at watershed scales, particularly in mixed land cover and land use systems. We use the Visualizing Ecosystem Land Management Assessments (VELMA) model to evaluate the effects of different LID practices on daily and long-term watershed-scale hydrology, including infiltration surface runoff. We focus on Shayler Crossing (SHC) watershed, a mixed land cover (61% urban, 24% agriculture, 15% forest) subwatershed of the East Fork Little Miami River watershed, Ohio, United States, with a drainage area of 0.94 km2. The model was calibrated to daily stream flow at the outlet of SHC watershed from 2009 to 2010 and was applied to evaluate diverse distributions (at 25% to 100% implementation levels) and types (e.g., pervious pavement and rain gardens) of LID across the watershed. Results show reduced surface water runoff and higher rates of infiltration concomitant with increasing LID implementation levels; however, this response varies between different LID practices. The highest magnitude response in streamflow at the watershed outlet is evident when a combination of LID practices is applied. The combined scenarios elucidate that the diverse watershed-scale hydrological responses of LID practices depend primarily on the type and extent of the implemented

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

Science.gov (United States)

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.

Assessment of watershed scale nitrogen cycling and dynamics by hydrochemical modeling

Science.gov (United States)

Onishi, T.; Hiramatsu, K.; Somura, H.

2017-12-01

Nitrogen cycling in terrestrial areas is affecting water quality and ecosystem of aquatic area such as lakes and oceans through rivers. Owing to the intensive researches on nitrogen cycling in each different type of ecosystem, we acquired rich knowledge on nitrogen cycling of each ecosystem. On the other hand, since watershed are composed of many different kinds of ecosystems, nitrogen cycling in a watershed as a complex of these ecosystems is not well quantified. Thus, comprehensive understanding of nitrogen cycling of watersheds by modelling efforts are required. In this study, we attempted to construct hydrochemical model of the Ise Bay watershed to reproduce discharge, TN, and NO3 concentration. The model is based on SWAT (Soil and Water Assessment Tools) model. As anthropogenic impacts related to both hydrological cycling and nitrogen cycling, agricultural water intake/drainage, and domestic water intake/drainage were considered. In addition, fertilizer input to agricultural lands were also considered. Calibration period and validation period are 2004-2006, and 2007-2009, respectively. As a result of calibration using 2000 times LCS (Latin Cubic Sampling) method, discharge of rivers were reproduced fairly well with NS of 0.6-0.8. In contrast, the calibration result of TN and NO3 concentration tended to show overestimate values in spite of considering parameter uncertainties. This implies that unimplemented denitrification processes in the model. Through exploring the results, it is indicated that riparian areas, and agricultural drainages might be important spots for denitrification. Based on the result, we also attempted to evaluate the impact of climate change on nitrogen cycling. Though it is fully explored, this result will also be reported.

The combined use of MODFLOW and precipitation-runoff modeling to simulate groundwater flow in a diffuse-pollution prone watershed.

Science.gov (United States)

Elçi, A; Karadaş, D; Fistikoğlu, O

2010-01-01

A numerical modeling case study of groundwater flow in a diffuse pollution prone area is presented. The study area is located within the metropolitan borders of the city of Izmir, Turkey. This groundwater flow model was unconventional in the application since the groundwater recharge parameter in the model was estimated using a lumped, transient water-budget based precipitation-runoff model that was executed independent of the groundwater flow model. The recharge rate obtained from the calibrated precipitation-runoff model was used as input to the groundwater flow model, which was eventually calibrated to measured water table elevations. Overall, the flow model results were consistent with field observations and model statistics were satisfactory. Water budget results of the model revealed that groundwater recharge comprised about 20% of the total water input for the entire study area. Recharge was the second largest component in the budget after leakage from streams into the subsurface. It was concluded that the modeling results can be further used as input for contaminant transport modeling studies in order to evaluate the vulnerability of water resources of the study area to diffuse pollution.

An approach to measure parameter sensitivity in watershed hydrologic modeling

Data.gov (United States)

U.S. Environmental Protection Agency — Abstract Hydrologic responses vary spatially and temporally according to watershed characteristics. In this study, the hydrologic models that we developed earlier...

Integration of a Hydrological Model within a Geographical Information System: Application to a Forest Watershed

Directory of Open Access Journals (Sweden)

Dimitris Fotakis

2014-03-01

Full Text Available Watershed simulation software used for operational purposes must possess both dependability of results and flexibility in parameter selection and testing. The UBC watershed model (UBCWM contains a wide spectrum of parameters expressing meteorological, geological, as well as ecological watershed characteristics. The hydrological model was coupled to the MapInfo GIS and the software created was named Watershed Mapper (WM. WM is endowed with several features permitting operational utilization. These include input data and basin geometry visualization, land use/cover and soil simulation, exporting of statistical results and thematic maps and interactive variation of disputed parameters. For the application of WM two hypothetical scenarios of forest fires were examined in a study watershed. Four major rainfall events were selected from 12-year daily precipitation data and the corresponding peak flows were estimated for the base line data and hypothetical scenarios. A significant increase was observed as an impact of forest fires on peak flows. Due to its flexibility the combined tool described herein may be utilized in modeling long-term hydrological changes in the context of unsteady hydrological analyses.

Identification of drought in Dhalai river watershed using MCDM and ANN models

Science.gov (United States)

Aher, Sainath; Shinde, Sambhaji; Guha, Shantamoy; Majumder, Mrinmoy

2017-03-01

An innovative approach for drought identification is developed using Multi-Criteria Decision Making (MCDM) and Artificial Neural Network (ANN) models from surveyed drought parameter data around the Dhalai river watershed in Tripura hinterlands, India. Total eight drought parameters, i.e., precipitation, soil moisture, evapotranspiration, vegetation canopy, cropping pattern, temperature, cultivated land, and groundwater level were obtained from expert, literature and cultivator survey. Then, the Analytic Hierarchy Process (AHP) and Analytic Network Process (ANP) were used for weighting of parameters and Drought Index Identification (DII). Field data of weighted parameters in the meso scale Dhalai River watershed were collected and used to train the ANN model. The developed ANN model was used in the same watershed for identification of drought. Results indicate that the Limited-Memory Quasi-Newton algorithm was better than the commonly used training method. Results obtained from the ANN model shows the drought index developed from the study area ranges from 0.32 to 0.72. Overall analysis revealed that, with appropriate training, the ANN model can be used in the areas where the model is calibrated, or other areas where the range of input parameters is similar to the calibrated region for drought identification.

Modeling precipitation-runoff relationships to determine water yield from a ponderosa pine forest watershed

Science.gov (United States)

Assefa S. Desta

2006-01-01

A stochastic precipitation-runoff modeling is used to estimate a cold and warm-seasons water yield from a ponderosa pine forested watershed in the north-central Arizona. The model consists of two parts namely, simulation of the temporal and spatial distribution of precipitation using a stochastic, event-based approach and estimation of water yield from the watershed...

Modelling traffic pollution in streets

Energy Technology Data Exchange (ETDEWEB)

Berkowicz, R.; Hertel, O. [National Environmental Research Inst., Dept. of Atmospheric Environment, Roskilde (Denmark); Larsen, S.E.; Soerensen, N.N.; Nielsen, M. [Risoe National Lab., Dept. of Meteorology and Wind Energy, Roskilde (Denmark)

1997-01-01

This report concerns mainly the subject related to modelling air pollution from traffic in urban streets. A short overview is presented over the theoretical aspects and examples of most commonly used methods and models are given. Flow and dispersion conditions in street canyons are discussed and the presentation is substantiated with the analysis of the experimental data. The main emphasis is on the modelling methods that are suitable for routine applications and a more detailed presentation is given of the Operational Street Pollution Model (OSPM), which was developed by the National Environmental Research Institute. The model is used for surveillance of air pollution from traffic in Danish cities and also for special air pollution studies. (au) 76 refs.

Application of the SWAT model to the Xiangjiang river watershed in subtropical central China.

Science.gov (United States)

Luo, Qiao; Li, Yong; Wang, Kelin; Wu, Jinshui

2013-01-01

The Soil and Water Assessment Tool (SWAT) model was applied to simulate the water balance in the Xiangjiang river watershed for current and planning scenarios of land uses. The model was first calibrated for the period from 1998 to 2002 and then validated for the period from 2003 to 2007 using the observed stream flow data from four monitoring gages within the watershed. The determination coefficient of linear regression of the observed and simulated monthly stream flows (R(2)) and their Nash-Sutcliffe Index (NSI) was used to evaluate model performance. All values of R(2) and NSI were above 0.8 and ranged from 0.82 to 0.92, which indicates that the SWAT model was capable of simulating the stream flow in the Xiangjiang river watershed. The calibrated and validated SWAT model was then applied to study the hydrological response of three land use change scenarios. Runoff was reduced by increasing the areas of forest and grassland while simultaneously decreasing the areas of agricultural and urban land. In the recent and future land use planning for the Xiangjiang river watershed, the hydrological effect should be considered in regional water management and erosion control.

Development of Water Quality Forecasting Models Based on the SOM-ANN on TMDL Unit Watershed in Nakdong River

Science.gov (United States)

KIM, M.; Kim, J.; Baek, J.; Kim, C.; Shin, H.

2013-12-01

It has being happened as flush flood or red/green tide in various natural phenomena due to climate change and indiscreet development of river or land. Especially, water being very important to man should be protected and managed from water quality pollution, and in water resources management, real-time watershed monitoring system is being operated with the purpose of keeping watch and managing on rivers. It is especially important to monitor and forecast water quality in watershed. A study area selected Nak_K as one site among TMDL unit watershed in Nakdong River. This study is to develop a water quality forecasting model connected with making full use of observed data of 8 day interval from Nakdong River Environment Research Center. When forecasting models for each of the BOD, DO, COD, and chlorophyll-a are established considering correlation of various water quality factors, it is needed to select water quality factors showing highly considerable correlation with each water quality factor which is BOD, DO, COD, and chlorophyll-a. For analyzing the correlation of the factors (reservoir discharge, precipitation, air temperature, DO, BOD, COD, Tw, TN, TP, chlorophyll-a), in this study, self-organizing map was used and cross correlation analysis method was also used for comparing results drawn. Based on the results, each forecasting model for BOD, DO, COD, and chlorophyll-a was developed during the short period as 8, 16, 24, 32 days at 8 day interval. The each forecasting model is based on neural network with back propagation algorithm. That is, the study is connected with self-organizing map for analyzing correlation among various factors and neural network model for forecasting of water quality. It is considerably effective to manage the water quality in plenty of rivers, then, it specially is possible to monitor a variety of accidents in water quality. It will work well to protect water quality and to prevent destruction of the environment becoming more and more

Stochastic Modeling of Traffic Air Pollution

DEFF Research Database (Denmark)

Thoft-Christensen, Palle

2014-01-01

In this paper, modeling of traffic air pollution is discussed with special reference to infrastructures. A number of subjects related to health effects of air pollution and the different types of pollutants are briefly presented. A simple model for estimating the social cost of traffic related air...... and using simple Monte Carlo techniques to obtain a stochastic estimate of the costs of traffic air pollution for infrastructures....... pollution is derived. Several authors have published papers on this very complicated subject, but no stochastic modelling procedure have obtained general acceptance. The subject is discussed basis of a deterministic model. However, it is straightforward to modify this model to include uncertain parameters...

A Workflow to Model Microbial Loadings in Watersheds (proceedings)

Science.gov (United States)

Many watershed models simulate overland and instream microbial fate and transport, but few actually provide loading rates on land surfaces and point sources to the water body network. This paper describes the underlying general equations for microbial loading rates associated wit...

Geomorphology-based unit hydrograph models for flood risk management: case study in Brazilian watersheds with contrasting physiographic characteristics

Directory of Open Access Journals (Sweden)

SAMUEL BESKOW

2018-05-01

Full Text Available ABSTRACT Heavy rainfall in conjunction with an increase in population and intensification of agricultural activities have resulted in countless problems related to flooding in watersheds. Among the techniques available for direct surface runoff (DSR modeling and flood risk management are the Unit Hydrograph (UH and Instantaneous Unit Hydrograph (IUH. This study focuses on the evaluation of predictive capability of two conceptual IUH models (Nash and Clark, considering their original (NIUH and CIUH and geomorphological approaches (NIUHGEO and CIUHGEO, and their advantages over two traditional synthetics UH models - Triangular (TUH and Dimensionless (DUH, to estimate DSR hydrographs taking as reference two Brazilian watersheds with contrasting geomorphological and climatic characteristics. The main results and conclusions were: i there was an impact of the differences in physiographical characteristics between watersheds, especially those parameters associated with soil; the dominant rainfall patterns in each watershed had an influence on flood modeling; and ii CIUH was the most satisfactory model for both watersheds, followed by NIUH, and both models had substantial superiority over synthetic models traditionally employed; iii although geomorphological approaches for IUH had performances slightly better than TUH and DUH, they should not be considered as standard tools for flood modeling in these watersheds.

Watershed Modeling System Hydrological Simulation Program; Watershed Model User Documentation and Tutorial

National Research Council Canada - National Science Library

Dellman, Patrick

2002-01-01

.... This analysis helps predict possible environmental problems in the watershed. With the growing need to care for and monitor the effects of man on the environment, it became apparent that a method for rapid analysis of those effects was needed...

Code modernization and modularization of APEX and SWAT watershed simulation models

Science.gov (United States)

SWAT (Soil and Water Assessment Tool) and APEX (Agricultural Policy / Environmental eXtender) are respectively large and small watershed simulation models derived from EPIC Environmental Policy Integrated Climate), a field-scale agroecology simulation model. All three models are coded in FORTRAN an...

A watershed modeling approach to streamflow reconstruction from tree-ring records

International Nuclear Information System (INIS)

Saito, Laurel; Biondi, Franco; Salas, Jose D; Panorska, Anna K; Kozubowski, Tomasz J

2008-01-01

Insight into long-term changes of streamflow is critical for addressing implications of global warming for sustainable water management. To date, dendrohydrologists have employed sophisticated regression techniques to extend runoff records, but this empirical approach cannot directly test the influence of watershed factors that alter streamflow independently of climate. We designed a mechanistic watershed model to calculate streamflows at annual timescales using as few inputs as possible. The model was calibrated for upper reaches of the Walker River, which straddles the boundary between the Sierra Nevada of California and the Great Basin of Nevada. Even though the model incorporated simplified relationships between precipitation and other components of the hydrologic cycle, it predicted water year streamflows with correlations of 0.87 when appropriate precipitation values were used

Accounting for small scale heterogeneity in ecohydrologic watershed models

Science.gov (United States)

Burke, W.; Tague, C.

2017-12-01

Spatially distributed ecohydrologic models are inherently constrained by the spatial resolution of their smallest units, below which land and processes are assumed to be homogenous. At coarse scales, heterogeneity is often accounted for by computing store and fluxes of interest over a distribution of land cover types (or other sources of heterogeneity) within spatially explicit modeling units. However this approach ignores spatial organization and the lateral transfer of water and materials downslope. The challenge is to account both for the role of flow network topology and fine-scale heterogeneity. We present a new approach that defines two levels of spatial aggregation and that integrates spatially explicit network approach with a flexible representation of finer-scale aspatial heterogeneity. Critically, this solution does not simply increase the resolution of the smallest spatial unit, and so by comparison, results in improved computational efficiency. The approach is demonstrated by adapting Regional Hydro-Ecologic Simulation System (RHESSys), an ecohydrologic model widely used to simulate climate, land use, and land management impacts. We illustrate the utility of our approach by showing how the model can be used to better characterize forest thinning impacts on ecohydrology. Forest thinning is typically done at the scale of individual trees, and yet management responses of interest include impacts on watershed scale hydrology and on downslope riparian vegetation. Our approach allow us to characterize the variability in tree size/carbon reduction and water transfers between neighboring trees while still capturing hillslope to watershed scale effects, Our illustrative example demonstrates that accounting for these fine scale effects can substantially alter model estimates, in some cases shifting the impacts of thinning on downslope water availability from increases to decreases. We conclude by describing other use cases that may benefit from this approach

Pinpointing Watershed Pollution on a Virtual Globe

Science.gov (United States)

Saunders, Cheston; Taylor, Amy

2014-01-01

Pollution is not a problem we just read about anymore. It affects the air we breathe, the land we live on, and the water we consume. After noticing a lack of awareness in students, a lesson was developed that used Google Earth to pinpoint sources of pollution in the local area and in others across the country, and their effects on the surrounding…

Lawrence Livermore National Laboratory Surface Water Protection: A Watershed Approach

Energy Technology Data Exchange (ETDEWEB)

Coty, J

2009-03-16

This surface water protection plan (plan) provides an overview of the management efforts implemented at Lawrence Livermore National Laboratory (LLNL) that support a watershed approach to protect surface water. This plan fulfills a requirement in the Department of Energy (DOE) Order 450.1A to demonstrate a watershed approach for surface water protection that protects the environment and public health. This plan describes the use of a watershed approach within which the Laboratory's current surface water management and protections efforts have been structured and coordinated. With more than 800 million acres of land in the U.S. under federal management and stewardship, a unified approach across agencies provides enhanced resource protection and cost-effectiveness. The DOE adopted, along with other federal agencies, the Unified Federal Policy for a Watershed Approach to Federal Land and Resource Management (UFP) with a goal to protect water quality and aquatic ecosystems on federal lands. This policy intends to prevent and/or reduce water pollution from federal activities while fostering a cost-effective watershed approach to federal land and resource management. The UFP also intends to enhance the implementation of existing laws (e.g., the Clean Water Act [CWA] and National Environmental Policy Act [NEPA]) and regulations. In addition, this provides an opportunity for the federal government to serve as a model for water quality stewardship using a watershed approach for federal land and resource activities that potentially impact surface water and its uses. As a federal land manager, the Laboratory is responsible for a small but important part of those 800 million acres of land. Diverse land uses are required to support the Laboratory's mission and provide an appropriate work environment for its staff. The Laboratory comprises two sites: its main site in Livermore, California, and the Experimental Test Site (Site 300), near Tracy, California. The main site

Calibration and validation of the SWAT model for a forested watershed in coastal South Carolina

Science.gov (United States)

Devendra M. Amatya; Elizabeth B. Haley; Norman S. Levine; Timothy J. Callahan; Artur Radecki-Pawlik; Manoj K. Jha

2008-01-01

Modeling the hydrology of low-gradient coastal watersheds on shallow, poorly drained soils is a challenging task due to the complexities in watershed delineation, runoff generation processes and pathways, flooding, and submergence caused by tropical storms. The objective of the study is to calibrate and validate a GIS-based spatially-distributed hydrologic model, SWAT...

Hydrologic processes of forested headwater watersheds across a physiographaic gradient in the southeastern United States

Science.gov (United States)

Ge Sun; Johnny Boggs; Steven G. McNulty; Devendra M. Amatya; Carl C. Trettin; Zhaohua Dai; James M. Vose; Ileana B. La Torre Torres; Timothy Callahan

2008-01-01

Understanding the hydrologic processes is the first step in making sound watershed management decisions including designing Best Management Practices for nonpoint source pollution control. Over the past fifty years, various forest experimental watersheds have been instrumented across the Carolinas through collaborative studies among federal, state, and private...

Improving the temporal transposability of lumped hydrological models on twenty diversified U.S. watersheds

Directory of Open Access Journals (Sweden)

G. Seiller

2015-03-01

Full Text Available Study region: Twenty diversified U.S. watersheds. Study focus: Identifying optimal parameter sets for hydrological modeling on a specific catchment remains an important challenge for numerous applied and research projects. This is particularly the case when working under contrasted climate conditions that question the temporal transposability of the parameters. Methodologies exist, mainly based on Differential Split Sample Tests, to examine this concern. This work assesses the improved temporal transposability of a multimodel implementation, based on twenty dissimilar lumped conceptual structures and on twenty U.S. watersheds, over the performance of the individual models. New hydrological insights for the region: Individual and collective temporal transposabilities are analyzed and compared on the twenty studied watersheds. Results show that individual models performances on contrasted climate conditions are very dissimilar depending on test period and watershed, without the possibility to identify a best solution in all circumstances. They also confirm that performance and robustness are clearly enhanced using an ensemble of rainfall-runoff models instead of individual ones. The use of (calibrated weight averaged multimodels further improves temporal transposability over simple averaged ensemble, in most instances, confirming added-value of this approach but also the need to evaluate how individual models compensate each other errors. Keywords: Rainfall-runoff modeling, Multimodel approach, Differential Split Sample Test, Deterministic combination, Outputs averaging

Application of the SWAT model to an endorheic watershed in the Central Spanish Pre-Pyrenees: Methodological approach and preliminary results

Science.gov (United States)

Gaspar, Leticia; White, Sue; Navas, Ana; López-Vicente, Manuel; Palazón, Leticia

2013-04-01

Modelling runoff and sediment transport at watershed scale are key tools to predict hydrological and sediment processes, identify soil sediment sources and estimate sediment yield, with the purpose of better managing soil and water resources. This study aims to apply the SWAT model in an endorheic watershed in the Central Spanish Pre-Pyrenees, where there have been a number of previous field-based studies on sediment sources and transfers. The Soil and Water Assessment Tool (SWAT) is a process based semi-distributed watershed scale hydrologic model, which can provide a high level of spatial detail by allowing the watershed to be divided into sub-basins. This study addresses the challenge of applying the SWAT model to an endorheic watershed that drains to a central lake, without external output, and without a network of permanent rivers. In this case it has been shown that the SWAT model does not correctly reproduce the stream network when using automatic watershed delineation, even with a high resolution Digital Elevation Model (5 x 5 metres). For this purpose, different approaches needed to be considered, such as i) user-defined watersheds and streams, ii) burning in a stream network or iii) modelling each sub-watershed separately. The objective of this study was to develop a new methodological approach for correctly simulating the main hydrological processes in an endorheic and complex karst watershed of the Spanish Pre-Pyrenees. The Estanque de Arriba Lake watershed (74 ha) is an endorheic system located in the Spanish Central Pre-Pyrenees. This watershed holds a small and permanent lake of fresh water (1.7 ha) and is a Site of Community Importance (European NATURA 2000 network). The study area is characterized by an abrupt topography with altitude range between 679 and 862 m and an average slope gradient of 24 %. Steep slopes (> 24 %) occupy the northern part of the watershed, whereas gentle slopes (

Evaluating the SWAT model for a low-gradient forested watershed in coastal South Carolina

Science.gov (United States)

D.M. Amatya; M.K. Jha.

2011-01-01

Modeling the hydrology of low�]gradient forested watersheds on shallow, poorly drained soils of the coastal plain is a challenging task due to complexities in watershed delineation, microtopography, evapotranspiration, runoff generation processes and pathways including flooding and submergence caused by tropical storms, and complexity of vegetation species....

Advancement in Watershed Modelling Using Dynamic Lateral and Longitudinal Sediment (Dis)connectivity Prediction

Science.gov (United States)

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

2017-12-01

The authors find that sediment (dis)connectivity has seldom taken precedence within watershed models, and the present study advances this modeling framework and applies the modeling within a bedrock-controlled system. Sediment (dis)connectivity, defined as the detachment and transport of sediment from source to sink between geomorphic zones, is a major control on sediment transport. Given the availability of high resolution geospatial data, coupling sediment connectivity concepts within sediment prediction models offers an approach to simulate sediment sources and pathways within a watershed's sediment cascade. Bedrock controlled catchments are potentially unique due to the presence of rock outcrops causing longitudinal impedance to sediment transport pathways in turn impacting the longitudinal distribution of the energy gradient responsible for conveying sediment. Therefore, the authors were motivated by the need to formulate a sediment transport model that couples sediment (dis)connectivity knowledge to predict sediment flux for bedrock controlled catchments. A watershed-scale sediment transport model was formulated that incorporates sediment (dis)connectivity knowledge collected via field reconnaissance and predicts sediment flux through coupling with the Partheniades equation and sediment continuity model. Sediment (dis)connectivity was formulated by coupling probabilistic upland lateral connectivity prediction with instream longitudinal connectivity assessments via discretization of fluid and sediment pathways. Flux predictions from the upland lateral connectivity model served as an input to the instream longitudinal connectivity model. Disconnectivity in the instream model was simulated via the discretization of stream reaches due to barriers such as bedrock outcroppings and man-made check dams. The model was tested for a bedrock controlled catchment in Kentucky, USA for which extensive historic water and sediment flux data was available. Predicted sediment

Evaluating Vegetation Potential for Wildfire Impacted Watershed Using a Bayesian Network Modeling Approach

Science.gov (United States)

Jaramillo, L. V.; Stone, M. C.; Morrison, R. R.

2017-12-01

Decision-making for natural resource management is complex especially for fire impacted watersheds in the Southwestern US because of the vital importance of water resources, exorbitant cost of fire management and restoration, and the risks of the wildland-urban interface (WUI). While riparian and terrestrial vegetation are extremely important to ecosystem health and provide ecosystem services, loss of vegetation due to wildfire, post-fire flooding, and debris flows can lead to further degradation of the watershed and increased vulnerability to erosion and debris flow. Land managers are charged with taking measures to mitigate degradation of the watershed effectively and efficiently with limited time, money, and data. For our study, a Bayesian network (BN) approach is implemented to understand vegetation potential for Kashe-Katuwe Tent Rocks National Monument in the fire-impacted Peralta Canyon Watershed, New Mexico, USA. We implement both two-dimensional hydrodynamic and Bayesian network modeling to incorporate spatial variability in the system. Our coupled modeling framework presents vegetation recruitment and succession potential for three representative plant types (native riparian, native terrestrial, and non-native) under several hydrologic scenarios and management actions. In our BN model, we use variables that address timing, hydrologic, and groundwater conditions as well as recruitment and succession constraints for the plant types based on expert knowledge and literature. Our approach allows us to utilize small and incomplete data, incorporate expert knowledge, and explicitly account for uncertainty in the system. Our findings can be used to help land managers and local decision-makers determine their plan of action to increase watershed health and resilience.

Impact of Climate Variability and Landscape Patterns on Water Budget and Nutrient Loads in a Peri-urban Watershed: A Coupled Analysis Using Process-based Hydrological Model and Landscape Indices

Science.gov (United States)

Li, Chongwei; Zhang, Yajuan; Kharel, Gehendra; Zou, Chris B.

2018-06-01

Nutrient discharge into peri-urban streams and reservoirs constitutes a significant pressure on environmental management, but quantitative assessment of non-point source pollution under climate variability in fast changing peri-urban watersheds is challenging. Soil and Water Assessment Tool (SWAT) was used to simulate water budget and nutrient loads for landscape patterns representing a 30-year progression of urbanization in a peri-urban watershed near Tianjin metropolis, China. A suite of landscape pattern indices was related to nitrogen (N) and phosphorous (P) loads under dry and wet climate using CANOCO redundancy analysis. The calibrated SWAT model was adequate to simulate runoff and nutrient loads for this peri-urban watershed, with Nash-Sutcliffe coefficient (NSE) and coefficient of determination ( R 2) > 0.70 and percentage bias (PBIAS) between -7 and +18 for calibration and validation periods. With the progression of urbanization, forest remained the main "sink" landscape while cultivated and urban lands remained the main "source" landscapes with the role of orchard and grassland being uncertain and changing with time. Compared to 1984, the landscape use pattern in 2013 increased nutrient discharge by 10%. Nutrient loads modelled under wet climate were 3-4 times higher than that under dry climate for the same landscape pattern. Results indicate that climate change could impose a far greater impact on runoff and nutrient discharge in a peri-urban watershed than landscape pattern change.

Impact of Climate Variability and Landscape Patterns on Water Budget and Nutrient Loads in a Peri-urban Watershed: A Coupled Analysis Using Process-based Hydrological Model and Landscape Indices.

Science.gov (United States)

Li, Chongwei; Zhang, Yajuan; Kharel, Gehendra; Zou, Chris B

2018-06-01

Nutrient discharge into peri-urban streams and reservoirs constitutes a significant pressure on environmental management, but quantitative assessment of non-point source pollution under climate variability in fast changing peri-urban watersheds is challenging. Soil and Water Assessment Tool (SWAT) was used to simulate water budget and nutrient loads for landscape patterns representing a 30-year progression of urbanization in a peri-urban watershed near Tianjin metropolis, China. A suite of landscape pattern indices was related to nitrogen (N) and phosphorous (P) loads under dry and wet climate using CANOCO redundancy analysis. The calibrated SWAT model was adequate to simulate runoff and nutrient loads for this peri-urban watershed, with Nash-Sutcliffe coefficient (NSE) and coefficient of determination (R 2 ) > 0.70 and percentage bias (PBIAS) between -7 and +18 for calibration and validation periods. With the progression of urbanization, forest remained the main "sink" landscape while cultivated and urban lands remained the main "source" landscapes with the role of orchard and grassland being uncertain and changing with time. Compared to 1984, the landscape use pattern in 2013 increased nutrient discharge by 10%. Nutrient loads modelled under wet climate were 3-4 times higher than that under dry climate for the same landscape pattern. Results indicate that climate change could impose a far greater impact on runoff and nutrient discharge in a peri-urban watershed than landscape pattern change.

The Virtual Watershed Observatory: Cyberinfrastructure for Model-Data Integration and Access

Science.gov (United States)

Duffy, C.; Leonard, L. N.; Giles, L.; Bhatt, G.; Yu, X.

2011-12-01

The Virtual Watershed Observatory (VWO) is a concept where scientists, water managers, educators and the general public can create a virtual observatory from integrated hydrologic model results, national databases and historical or real-time observations via web services. In this paper, we propose a prototype for automated and virtualized web services software using national data products for climate reanalysis, soils, geology, terrain and land cover. The VWO has the broad purpose of making accessible water resource simulations, real-time data assimilation, calibration and archival at the scale of HUC 12 watersheds (Hydrologic Unit Code) anywhere in the continental US. Our prototype for model-data integration focuses on creating tools for fast data storage from selected national databases, as well as the computational resources necessary for a dynamic, distributed watershed simulation. The paper will describe cyberinfrastructure tools and workflow that attempts to resolve the problem of model-data accessibility and scalability such that individuals, research teams, managers and educators can create a WVO in a desired context. Examples are given for the NSF-funded Shale Hills Critical Zone Observatory and the European Critical Zone Observatories within the SoilTrEC project. In the future implementation of WVO services will benefit from the development of a cloud cyber infrastructure as the prototype evolves to data and model intensive computation for continental scale water resource predictions.

Monitoring and Analysis of Nonpoint Source Pollution - Case study on terraced paddy fields in an agricultural watershed

Science.gov (United States)

Chen, Shih-Kai; Jang, Cheng-Shin; Yeh, Chun-Lin

2013-04-01

The intensive use of chemical fertilizer has negatively impacted environments in recent decades, mainly through water pollution by nitrogen (N) and phosphate (P) originating from agricultural activities. As a main crop with the largest cultivation area about 0.25 million ha per year in Taiwan, rice paddies account for a significant share of fertilizer consumption among agriculture crops. This study evaluated the fertilization of paddy fields impacting return flow water quality in an agricultural watershed located at Hsinchu County, northern Taiwan. Water quality monitoring continued for two crop-periods in 2012, around subject to different water bodies, including the irrigation water, drainage water, and shallow groundwater. The results indicated that obviously increasing of ammonium-N, nitrate-N and TP concentrations in the surface drainage water were observed immediately following three times of fertilizer applications (including basal, tillering, and panicle fertilizer application), but reduced to relatively low concentrations after 7-10 days after each fertilizer application. Groundwater quality monitoring showed that the observation wells with the more shallow water depth, the more significant variation of concentrations of ammonium-N, nitrate-N and TP could be observed, which means that the contamination potential of nutrient of groundwater is related not only to the impermeable plow sole layer but also to the length of percolation route in this area. The study also showed that the potential pollution load of nutrient could be further reduced by well drainage water control and rational fertilizer management, such as deep-water irrigation, reuse of return flow, the rational application of fertilizers, and the SRI (The System of Rice Intensification) method. The results of this study can provide as an evaluation basis to formulate effective measures for agricultural non-point source pollution control and the reuse of agricultural return flow. Keywords

Selection and placement of best management practices used to reduce water quality degradation in Lincoln Lake watershed

Science.gov (United States)

Rodriguez, Hector German; Popp, Jennie; Maringanti, Chetan; Chaubey, Indrajeet

2011-01-01

An increased loss of agricultural nutrients is a growing concern for water quality in Arkansas. Several studies have shown that best management practices (BMPs) are effective in controlling water pollution. However, those affected with water quality issues need water management plans that take into consideration BMPs selection, placement, and affordability. This study used a nondominated sorting genetic algorithm (NSGA-II). This multiobjective algorithm selects and locates BMPs that minimize nutrients pollution cost-effectively by providing trade-off curves (optimal fronts) between pollutant reduction and total net cost increase. The usefulness of this optimization framework was evaluated in the Lincoln Lake watershed. The final NSGA-II optimization model generated a number of near-optimal solutions by selecting from 35 BMPs (combinations of pasture management, buffer zones, and poultry litter application practices). Selection and placement of BMPs were analyzed under various cost solutions. The NSGA-II provides multiple solutions that could fit the water management plan for the watershed. For instance, by implementing all the BMP combinations recommended in the lowest-cost solution, total phosphorous (TP) could be reduced by at least 76% while increasing cost by less than 2% in the entire watershed. This value represents an increase in cost of 5.49 ha-1 when compared to the baseline. Implementing all the BMP combinations proposed with the medium- and the highest-cost solutions could decrease TP drastically but will increase cost by 24,282 (7%) and $82,306 (25%), respectively.

Reducing nonpoint source pollution through collaboration: policies and programs across the U.S. States.

Science.gov (United States)

Hardy, Scott D; Koontz, Tomas M

2008-03-01

Nonpoint source (NPS) pollution has emerged as the largest threat to water quality in the United States, influencing policy makers and resource managers to direct more attention toward NPS prevention and remediation. In response, the United States Environmental Protection Agency (USEPA) spent more than $204 million in fiscal year (FY) 2006 on the Clean Water Act's Section 319 program to combat NPS pollution, much of it on the development and implementation of watershed-based plans. State governments have also increasingly allocated financial and technical resources to collaborative watershed efforts within their own borders to fight NPS pollution. With increased collaboration among the federal government, states, and citizens to combat NPS pollution, more information is needed to understand how public resources are being used, by whom, and for what, and what policy changes might improve effectiveness. Analysis from a 50-state study suggests that, in addition to the average 35% of all Section 319 funds per state that are passed on to collaborative watershed groups, 35 states have provided financial assistance beyond Section 319 funding to support collaborative watershed initiatives. State programs frequently provide technical assistance and training, in addition to financial resources, to encourage collaborative partnerships. Such assistance is typically granted in exchange for requirements to generate a watershed action plan and/or follow a mutually agreed upon work plan to address NPS pollution. Program managers indicated a need for greater fiscal resources and flexibility to achieve water quality goals.

Evaluation of non-point source pollution reduction by applying best management practices using a SWAT model and QuickBird high resolution satellite imagery.

Science.gov (United States)

Lee, MiSeon; Park, GeunAe; Park, MinJi; Park, JongYoon; Lee, JiWan; Kim, SeongJoon

2010-01-01

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

Evaluating watershed protection programs in New York City's Cannonsville Reservoir source watershed using SWAT-HS

Science.gov (United States)

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

A Stochastic Multi-Media Model of Microbial Transport in Watersheds

Science.gov (United States)

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.

AirPEx. Air Pollution Exposure Model

Energy Technology Data Exchange (ETDEWEB)

Freijer, J.I.; Bloemen, H.J.Th.; De Loos, S.; Marra, M.; Rombout, P.J.A.; Steentjes, G.M.; Van Veen, M.P.

1997-12-01

Analysis of inhalatory exposure to air pollution is an important area of investigation when assessing the risks of air pollution for human health. Inhalatory exposure research focuses on the exposure of humans to air pollutants and the entry of these pollutants into the human respiratory tract. The principal grounds for studying the inhalatory exposure of humans to air pollutants are formed by the need for realistic exposure/dose estimates to evaluate the health effects of these pollutants. The AirPEx (Air Pollution Exposure) model, developed to assess the time- and space-dependence of inhalatory exposure of humans to air pollution, has been implemented for use as a Windows 3.1 computer program. The program is suited to estimating various exposure and dose quantities for individuals, as well as for populations and subpopulations. This report describes the fundamentals of the AirPEx model and provides a user manual for the computer program. Several examples included in the report illustrate the possibilities of the AirPEx model in exposure assessment. The model will be used at the National Institute of Public Health and the Environment as a tool in analysing the current exposure of the Dutch population to air pollutants. 57 refs.

Modelling Snowmelt Runoff under Climate Change Scenarios in an Ungauged Mountainous Watershed, Northwest China

Directory of Open Access Journals (Sweden)

Yonggang Ma

2013-01-01

Full Text Available An integrated modeling system has been developed for analyzing the impact of climate change on snowmelt runoff in Kaidu Watershed, Northwest China. The system couples Hadley Centre Coupled Model version 3 (HadCM3 outputs with Snowmelt Runoff Model (SRM. The SRM was verified against observed discharge for outlet hydrological station of the watershed during the period from April to September in 2001 and generally performed well for Nash-Sutcliffe coefficient (EF and water balance coefficient (RE. The EF is approximately over 0.8, and the water balance error is lower than ± 10%, indicating reasonable prediction accuracy. The Statistical Downscaling Model (SDSM was used to downscale coarse outputs of HadCM3, and then the downscaled future climate data were used as inputs of the SRM. Four scenarios were considered for analyzing the climate change impact on snowmelt flow in the Kaidu Watershed. And the results indicated that watershed hydrology would alter under different climate change scenarios. The stream flow in spring is likely to increase with the increased mean temperature; the discharge and peck flow in summer decrease with the decreased precipitation under Scenarios 1 and 2. Moreover, the consideration of the change in cryosphere area would intensify the variability of stream flow under Scenarios 3 and 4. The modeling results provide useful decision support for water resources management.

Finite Element Simulation of Total Nitrogen Transport in Riparian Buffer in an Agricultural Watershed

Directory of Open Access Journals (Sweden)

Xiaosheng Lin

2016-03-01

Full Text Available Riparian buffers can influence water quality in downstream lakes or rivers by buffering non-point source pollution in upstream agricultural fields. With increasing nitrogen (N pollution in small agricultural watersheds, a major function of riparian buffers is to retain N in the soil. A series of field experiments were conducted to monitor pollutant transport in riparian buffers of small watersheds, while numerical model-based analysis is scarce. In this study, we set up a field experiment to monitor the retention rates of total N in different widths of buffer strips and used a finite element model (HYDRUS 2D/3D to simulate the total N transport in the riparian buffer of an agricultural non-point source polluted area in the Liaohe River basin. The field experiment retention rates for total N were 19.4%, 26.6%, 29.5%, and 42.9% in 1,3,4, and 6m-wide buffer strips, respectively. Throughout the simulation period, the concentration of total N of the 1mwide buffer strip reached a maximum of 1.27 mg/cm3 at 30 min, decreasing before leveling off. The concentration of total N about the 3mwide buffer strip consistently increased, with a maximum of 1.05 mg/cm3 observed at 60 min. Under rainfall infiltration, the buffer strips of different widths showed a retention effect on total N transport, and the optimum effect was simulated in the 6mwide buffer strip. A comparison between measured and simulated data revealed that finite element simulation could simulate N transport in the soil of riparian buffer strips.

Scientific and technical advisory committee review of the nutrient inputs to the watershed model

Science.gov (United States)

The following is a report by a STAC Review Team concerning the methods and documentation used by the Chesapeake Bay Partnership for evaluation of nutrient inputs to Phase 6 of the Chesapeake Bay Watershed Model. The “STAC Review of the Nutrient Inputs to the Watershed Model” (previously referred to...

75 FR 27552 - Guidance for Federal Land Management in the Chesapeake Bay Watershed

Science.gov (United States)

2010-05-17

... will allow the federal government to lead the way in protecting the Bay and its watershed with the most effective tools and practices available to reduce water pollution from a variety of nonpoint sources... describe ``proven cost-effective tools and practices that reduce water pollution'' that are appropriate to...

The Potential Importance of Conservation, Restoration and Altered Management Practices for Water Quality in the Wabash River Watershed

Science.gov (United States)

Yang, G.; Best, E. P.; Goodwin, S.

2013-12-01

Non-point source (NPS) pollution is one of the leading causes of water quality impairment within the United States. Conservation, restoration and altered management (CRAM) practices may effectively reduce NPS pollutants to receiving water bodies and enhance local and regional ecosystem services. Barriers for the implementation of CRAM include uncertainties related to the extent to which nutrients are removed by CRAM at various spatial and temporal scales, longevity, optimal placement of CRAM within the landscape, and implementation / operation / maintenance costs. We conducted a study aimed at the identification of optimal placement of CRAM in watersheds that reduces N loading to an environmentally sustainable level, at an acceptable, known, cost. For this study, we used a recently developed screening-level modeling approach, WQM-TMDL-N, running in the ArcGIS environment, to estimate nitrogen loading under current land use conditions (NLCD 2006). This model was equipped with a new option to explore the performances of placement of various CRAM types and areas to reduce nitrogen loading to a State-accepted Total Maximum Daily Load (TMDL) standard, with related annual average TN concentration, and a multi-objective algorithm optimizing load and cost. CRAM practices explored for implementation in rural area included buffer strips, nutrient management practices, and wetland restoration. We initially applied this modeling approach to the Tippecanoe River (TR) watershed (8-digit HUC), a headwater of the Wabash River (WR) watershed, where CRAM implementation in rural and urban areas is being planned and implemented at various spatial scales. Consequences of future land use are explored using a 2050 land use/land cover map forecasted by the Land Transformation Model. The WR watershed, IN, drains two-thirds of the state's 92 counties and supports predominantly agricultural land use. Because the WR accounts for over 40% of the nutrient loads of the Ohio River and

Improved daily precipitation nitrate and ammonium concentration models for the Chesapeake Bay Watershed.

Science.gov (United States)

Grimm, J W; Lynch, J A

2005-06-01

Daily precipitation nitrate and ammonium concentration models were developed for the Chesapeake Bay Watershed (USA) using a linear least-squares regression approach and precipitation chemistry data from 29 National Atmospheric Deposition Program/National Trends Network (NADP/NTN) sites. Only weekly samples that comprised a single precipitation event were used in model development. The most significant variables in both ammonium and nitrate models included: precipitation volume, the number of days since the last event, a measure of seasonality, latitude, and the proportion of land within 8km covered by forest or devoted to industry and transportation. Additional variables included in the nitrate model were the proportion of land within 0.8km covered by water and/or forest. Local and regional ammonia and nitrogen oxide emissions were not as well correlated as land cover. Modeled concentrations compared very well with event chemistry data collected at six NADP/AirMoN sites within the Chesapeake Bay Watershed. Wet deposition estimates were also consistent with observed deposition at selected sites. Accurately describing the spatial distribution of precipitation volume throughout the watershed is important in providing critical estimates of wet-fall deposition of ammonium and nitrate.

Asotin Creek Model Watershed Plan: Asotin County, Washington, 1995.

Energy Technology Data Exchange (ETDEWEB)

Browne, Dave

1995-04-01

The Northwest Power Planning Council completed its ``Strategy for Salmon'' in 1992. This is a plan, composed of four specific elements,designed to double the present production of 2.5 million salmon in the Columbia River watershed. These elements have been called the ``four H's'': (1) improve harvest management; (2) improve hatcheries and their production practices; (3) improve survival at hydroelectric dams; and (4) improve and protect fish habitat. The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ``Strategy for Salmon''. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity.

Pataha Creek Model Watershed : January 2000-December 2002 Habitat Conservation Projects.

Energy Technology Data Exchange (ETDEWEB)

Bartels, Duane G.

2003-04-01

The projects outlined in detail on the attached project reports were implemented from calendar year 2000 through 2002 in the Pataha Creek Watershed. The Pataha Creek Watershed was selected in 1993, along with the Tucannon and Asotin Creeks, as model watersheds by NPPC. In previous years, demonstration sites using riparian fencing, off site watering facilities, tree and shrub plantings and upland conservation practices were used for information and education and were the main focus of the implementation phase of the watershed plan. These practices were the main focus of the watershed plan to reduce the majority of the sediment entering the stream. Prior to 2000, several bank stabilization projects were installed but the installation costs became prohibitive and these types of projects were reduced in numbers over the following years. The years 2000 through 2002 were years where a focused effort was made to work on the upland conservation practices to reduce the sedimentation into Pataha Creek. Over 95% of the sediment entering the stream can be tied directly to the upland and riparian areas of the watershed. The Pataha Creek has steelhead in the upper reaches and native and planted rainbow trout in the mid to upper portion. Suckers, pikeminow and shiners inhabit the lower portion because of the higher water temperatures and lack of vegetation. The improvement of riparian habitat will improve habitat for the desired fish species. The lower portion of the Pataha Creek could eventually develop into spawning and rearing habitat for chinook salmon if some migration barriers are removed and habitat is restored. The upland projects completed during 2000 through 2002 were practices that reduce erosion from the cropland. Three-year continuous no-till projects were finishing up and the monitoring of this particular practice is ongoing. Its direct impact on soil erosion along with the economical aspects is being studied. Other practices such as terrace, waterway, sediment

AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT ...

Science.gov (United States)

The Automated Geospatial Watershed Assessment tool (AGWA) is a GIS interface jointly developed by the USDA Agricultural Research Service, the U.S. Environmental Protection Agency, the University of Arizona, and the University of Wyoming to automate the parameterization and execution of the Soil Water Assessment Tool (SWAT) and KINEmatic Runoff and EROSion (KINEROS2) hydrologic models. The application of these two models allows AGWA to conduct hydrologic modeling and watershed assessments at multiple temporal and spatial scales. AGWA’s current outputs are runoff (volumes and peaks) and sediment yield, plus nitrogen and phosphorus with the SWAT model. AGWA uses commonly available GIS data layers to fully parameterize, execute, and visualize results from both models. Through an intuitive interface the user selects an outlet from which AGWA delineates and discretizes the watershed using a Digital Elevation Model (DEM) based on the individual model requirements. The watershed model elements are then intersected with soils and land cover data layers to derive the requisite model input parameters. The chosen model is then executed, and the results are imported back into AGWA for visualization. This allows managers to identify potential problem areas where additional monitoring can be undertaken or mitigation activities can be focused. AGWA also has tools to apply an array of best management practices. There are currently two versions of AGWA available; AGWA 1.5 for

ASSESSMENT OF WATER BALANCE OF A WATERSHED USING SWAT MODEL FOR WATER RESOURCES MANAGEMENT

OpenAIRE

Sandra George; Sathian, K.K.

2016-01-01

An attempt has been made in this study to assess the hydrological behavior of the Kurumali sub basin of Karuvannur river basin using SWAT model and other geospatial technologies. All the thematic maps and attribute information of the watershed have been collected from various Government agencies. SWAT model has been set up for the Kurumali sub basin by inputting the digital thematic maps, physical properties of soil and climatic parameters. Total area of the watershed corresponding to the out...

Watershed-scale modeling of streamflow change in incised montane meadows

Science.gov (United States)

Essaid, Hedeff I.; Hill, Barry R.

2014-01-01

Land use practices have caused stream channel incision and water table decline in many montane meadows of the Western United States. Incision changes the magnitude and timing of streamflow in water supply source watersheds, a concern to resource managers and downstream water users. The hydrology of montane meadows under natural and incised conditions was investigated using watershed simulation for a range of hydrologic conditions. The results illustrate the interdependence between: watershed and meadow hydrology; bedrock and meadow aquifers; and surface and groundwater flow through the meadow for the modeled scenarios. During the wet season, stream incision resulted in less overland flow and interflow and more meadow recharge causing a net decrease in streamflow and increase in groundwater storage relative to natural meadow conditions. During the dry season, incision resulted in less meadow evapotranspiration and more groundwater discharge to the stream causing a net increase in streamflow and a decrease in groundwater storage relative to natural meadow conditions. In general, for a given meadow setting, the magnitude of change in summer streamflow and long-term change in watershed groundwater storage due to incision will depend on the combined effect of: reduced evapotranspiration in the eroded meadow; induced groundwater recharge; replenishment of dry season groundwater storage depletion in meadow and bedrock aquifers by precipitation during wet years; and groundwater storage depletion that is not replenished by precipitation during wet years.

Vehicular pollution modeling using the operational street pollution model (OSPM) for Chembur, Mumbai (India)

DEFF Research Database (Denmark)

Kumar, Awkash; Ketzel, Matthias; Patil, Rashmi S.

2016-01-01

Megacities in India such as Mumbai and Delhi are among the most polluted places in the world. In the present study, the widely used operational street pollution model (OSPM) is applied for assessing pollutant loads in the street canyons of Chembur, a suburban area just outside Mumbai city. Chembur...... concentrations from the routine monitoring performed in Mumbai. NOx emissions originate mainly from vehicles which are ground-level sources and are emitting close to where people live. Therefore, those emissions are highly relevant. The modeled NOx concentration compared satisfactorily with observed data...

Use of Nutrient Balances in Comprehensive Watershed Water Quality Modeling of Chesapeake Bay

National Research Council Canada - National Science Library

Donigian, Anthony

1998-01-01

... state of-the-art watershed modeling capability that includes detailed soil process simulation for agricultural areas, linked to an instream water quality and nutrient model capable of representing...

ArcAPEX modeling of optimum widths and placement of grass and agroforestry buffers to reduce runoff and sediment transport in claypan watersheds

Science.gov (United States)

Existence of a claypan layer in soils at depths ranging from 4 to 37 cm restricts vertical water movement and has contributed significantly to high rates of runoff, sediment transport, and other non-point source loadings from croplands in watersheds. The deposition of these pollutants in rivers, st...

Application of TREECS Modeling System to Strontium-90 for Borschi Watershed near Chernobyl, Ukraine

International Nuclear Information System (INIS)

Johnson, Billy E.; Dortch, Mark S.

2014-01-01

The Training Range Environmental Evaluation and Characterization System (TREECS™) ( (http://el.erdc.usace.army.mil/treecs/)) is being developed by the U.S. Army Engineer Research and Development Center (ERDC) for the U.S. Army to forecast the fate of munitions constituents (MC) (such as high explosives (HE) and metals) found on firing/training ranges, as well as those subsequently transported to surface water and groundwater. The overall purpose of TREECS™ is to provide environmental specialists with tools to assess the potential for MC migration into surface water and groundwater systems and to assess range management strategies to ensure protection of human health and the environment. The multimedia fate/transport models within TREECS™ are mathematical models of reduced form (e.g., reduced dimensionality) that allow rapid application with less input data requirements compared with more complicated models. Although TREECS™ was developed for the fate of MC from military ranges, it has general applicability to many other situations requiring prediction of contaminant (including radionuclide) fate in multi-media environmental systems. TREECS™ was applied to the Borschi watershed near the Chernobyl Nuclear Power Plant, Ukraine. At this site, TREECS™ demonstrated its use as a modeling tool to predict the fate of strontium 90 ( 90 Sr). The most sensitive and uncertain input for this application was the soil-water partitioning distribution coefficient (K d ) for 90 Sr. The TREECS™ soil model provided reasonable estimates of the surface water export flux of 90 Sr from the Borschi watershed when using a K d for 90 Sr of 200 L/kg. The computed export for the year 2000 was 0.18% of the watershed inventory of 90 Sr compared to the estimated export flux of 0.14% based on field data collected during 1999–2001. The model indicated that assumptions regarding the form of the inventory, whether dissolved or in solid phase form, did not appreciably affect export

Bacteria transport simulation using APEX model in the Toenepi watershed, New Zealand

Science.gov (United States)

The Agricultural Policy/Environmental eXtender (APEX) model is a distributed, continuous, daily-time step small watershed-scale hydrologic and water quality model. In this study, the newly developed fecal-derived bacteria fate and transport subroutine was applied and evalated using APEX model. The e...

Sources, fate, and transport of nitrogen and phosphorus in the Chesapeake Bay watershed-An empirical model

Science.gov (United States)

Ator, Scott W.; Brakebill, John W.; Blomquist, Joel D.

2011-01-01

Spatially Referenced Regression on Watershed Attributes (SPARROW) was used to provide empirical estimates of the sources, fate, and transport of total nitrogen (TN) and total phosphorus (TP) in the Chesapeake Bay watershed, and the mean annual TN and TP flux to the bay and in each of 80,579 nontidal tributary stream reaches. Restoration efforts in recent decades have been insufficient to meet established standards for water quality and ecological conditions in Chesapeake Bay. The bay watershed includes 166,000 square kilometers of mixed land uses, multiple nutrient sources, and variable hydrogeologic, soil, and weather conditions, and bay restoration is complicated by the multitude of nutrient sources and complex interacting factors affecting the occurrence, fate, and transport of nitrogen and phosphorus from source areas to streams and the estuary. Effective and efficient nutrient management at the regional scale in support of Chesapeake Bay restoration requires a comprehensive understanding of the sources, fate, and transport of nitrogen and phosphorus in the watershed, which is only available through regional models. The current models, Chesapeake Bay nutrient SPARROW models, version 4 (CBTN_v4 and CBTP_v4), were constructed at a finer spatial resolution than previous SPARROW models for the Chesapeake Bay watershed (versions 1, 2, and 3), and include an updated timeframe and modified sources and other explantory terms.

Watershed-based survey designs

Science.gov (United States)

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.

Hydrological modeling of the Simly Dam watershed (Pakistan using GIS and SWAT model

Directory of Open Access Journals (Sweden)

Shimaa M. Ghoraba

2015-09-01

Full Text Available Modern mathematical models have been developed for studying the complex hydrological processes of a watershed and their direct relation to weather, topography, geology and land use. In this study the hydrology of Simly Dam watershed located in Saon River basin at the north-east of Islamabad is modeled, using the Soil and Water Assessment Tool (SWAT. It aims to simulate the stream flow, establish the water balance and estimate the monthly volume inflow to Simly Dam in order to help the managers to plan and handle this important reservoir. The ArcSWAT interface implemented in the ArcGIS software was used to delineate the study area and its sub-components, combine the data layers and edit the model database. The model was calibrated from 1990 to 2001 and evaluated from 2002 to 2011. Based on four recommended statistical coefficients, the evaluation indicates a good performance for both calibration and validation periods and acceptable agreement between measured and simulated values of both annual and monthly scale discharge. The water balance components were correctly estimated and the Simly Dam inflow was successfully reproduced with Coefficient of Determination (R2 of 0.75. These results revealed that if properly calibrated, SWAT model can be used efficiently in semi-arid regions to support water management policies.

Predicting watershed post-fire sediment yield with the InVEST sediment retention model: Accuracy and uncertainties

Science.gov (United States)

Sankey, Joel B.; McVay, Jason C.; Kreitler, Jason R.; Hawbaker, Todd J.; Vaillant, Nicole; Lowe, Scott

2015-01-01

Increased sedimentation following wildland fire can negatively impact water supply and water quality. Understanding how changing fire frequency, extent, and location will affect watersheds and the ecosystem services they supply to communities is of great societal importance in the western USA and throughout the world. In this work we assess the utility of the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) Sediment Retention Model to accurately characterize erosion and sedimentation of burned watersheds. InVEST was developed by the Natural Capital Project at Stanford University (Tallis et al., 2014) and is a suite of GIS-based implementations of common process models, engineered for high-end computing to allow the faster simulation of larger landscapes and incorporation into decision-making. The InVEST Sediment Retention Model is based on common soil erosion models (e.g., USLE – Universal Soil Loss Equation) and determines which areas of the landscape contribute the greatest sediment loads to a hydrological network and conversely evaluate the ecosystem service of sediment retention on a watershed basis. In this study, we evaluate the accuracy and uncertainties for InVEST predictions of increased sedimentation after fire, using measured postfire sediment yields available for many watersheds throughout the western USA from an existing, published large database. We show that the model can be parameterized in a relatively simple fashion to predict post-fire sediment yield with accuracy. Our ultimate goal is to use the model to accurately predict variability in post-fire sediment yield at a watershed scale as a function of future wildfire conditions.

Comparisons of remotely sensed and model-simulated soil moisture over a heterogenous watershed

International Nuclear Information System (INIS)

Lin, D.S.; Wood, E.F.; Troch, P.A.; Mancini, M.; Jackson, T.J.

1994-01-01

Soil moisture estimates from a distributed hydrologic model and two microwave airborne sensors (Push Broom Microwave Radiometer and Synthetic Aperture Radar) are compared with ground measurements on two different scales, using data collected during afield experiment over a 7.4-km 2 heterogeneous watershed located in central Pennsylvania. It is found that both microwave sensors and the hydrologic model successfully reflect the temporal variation of soil moisture. Watershed-averaged soil moistures estimated by the microwave sensors are in good agreement with ground measurements. The hydrologic model initialized by stream flow records yields estimates that are wetter than observations. The preliminary test of utilizing remotely sensed information as a feedback to correct the initial state of the hydrologic model shows promising results. (author)

Nonpoint source water pollution abatement and the feasibility of voluntary programs

Science.gov (United States)

Sawicki, David S.; Judd, Lynne B.

1983-09-01

This article details a case study of a voluntary, decentralized institutional arrangement for nonpint source water pollution control used in the Root River watershed in southeastern Wisconsin. This watershed was chosen because of its mix of urban, agricultural, and urbanizing land uses. The project objectives were to monitor and draw conclusions about the effectiveness of a voluntary, decentralized institutional system, to specify deficiencies of the approach and suggest means to correct them, and to use the conclusions to speculate about the need for regulations regarding nonpoint source pollution control or the appropriateness of financial incentives for nonpoint source control. Institutional factors considered include diversity of land uses in the watershed, educational needs, economic conditions, personality, water quality, number of agencies involved, definition of authority, and bureaucratic requirements

Modelling pollutant emissions in diesel engines, influence of biofuel on pollutant formation.

Science.gov (United States)

Petranović, Zvonimir; Bešenić, Tibor; Vujanović, Milan; Duić, Neven

2017-12-01

In order to reduce the harmful effect on the environment, European Union allowed using the biofuel blends as fuel for the internal combustion engines. Experimental studies have been carried on, dealing with the biodiesel influence on the emission concentrations, showing inconclusive results. In this paper numerical model for pollutant prediction in internal combustion engines is presented. It describes the processes leading towards the pollutant emissions, such as spray particles model, fuel disintegration and evaporation model, combustion and the chemical model for pollutant formation. Presented numerical model, implemented in proprietary software FIRE ® , is able to capture chemical phenomena and to predict pollutant emission concentration trends. Using the presented model, numerical simulations of the diesel fuelled internal combustion engine have been performed, with the results validated against the experimental data. Additionally, biodiesel has been used as fuel and the levels of pollutant emissions have been compared to the diesel case. Results have shown that the biodiesel blends release lower nitrogen oxide emissions than the engines powered with the regular diesel. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multiscale Modeling of Radioisotope Transfers in Watersheds, Rivers, Reservoirs and Ponds of Fukushima Prefecture

Science.gov (United States)

Zheleznyak, M.; Kivva, S.; Nanba, K.; Wakiyama, Y.; Konoplev, A.; Onda, Y.; Gallego, E.; Papush, L.; Maderych, V.

2015-12-01

The highest densities of the radioisotopes in fallout from the Fukushima Daiichi NPP in March 2011 were measured at the north eastern part of Fukushima Prefecture. The post-accidental aquatic transfer of cesium -134/137 includes multiscale processes: wash-off from the watersheds in solute and with the eroded soil, long-range transport in the rivers, deposition and resuspension of contaminated sediments in reservoirs and floodplains. The models of EU decision support system RODOS are used for predicting dynamics of 137Cs in the Fukushima surface waters and for assessing efficiency of the remediation measures. The transfer of 137Cs through the watershed of Niida River was simulated by DHSVM -R model that includes the modified code of the distributed hydrological and sediment transport model DHSVM (Lettenmayer, Wigmosta et al.) and new module of radionuclide transport. DHSMV-R was tested by modelling the wash-off from the USLE experimental plots in Fukushima prefecture. The model helps to quantify the influence of the differentiators of Fukushima and Chernobyl watersheds, - intensity of extreme precipitation and steepness of watershed, on the much higher values of the ratio "particulated cesium /soluted cesium" in Fukushima rivers than in Chernobyl rivers. Two dimensional model COASTOX and three dimensional model THREETOX are used to simulate the fate of 137Cs in water and sediments of reservoirs in the Manogawa River, Otagawa River, Mizunashigawa River, which transport 137Cs from the heavy contaminated watersheds to the populated areas at the Pacific coast. The modeling of the extreme floods generated by typhoons shows the resuspension of the bottom sediments from the heavy contaminated areas in reservoirs at the mouths of inflowing rivers at the peaks of floods and then re-deposition of 137Cs downstream in the deeper areas. The forecasts of 137Cs dynamics in bottom sediments of the reservoirs were calculated for the set of the scenarios of the sequences of the high

Modeled Watershed Runoff Associated with Variations in Precipitation Data, with Implications for Contaminant Fluxes: Initial Results

Science.gov (United States)

Precipitation is one of the primary forcing functions of hydrologic and watershed fate and transport models; however, in light of advances in precipitation estimates across watersheds, data remain highly uncertain. A wide variety of simulated and observed precipitation data are a...

Optimal land use/cover classification using remote sensing imagery for hydrological modelling in a Himalayan watershed

NARCIS (Netherlands)

Sameer Saran,; Sterk, G.; Kumar, S.

2007-01-01

Land use/cover is an important watershed surface characteristic that affects surface runoff and erosion. Many of the available hydrological models divide the watershed into Hydrological Response Units (HRU), which are spatial units with expected similar hydrological behaviours. The division into

Evaluating Hydrologic Transience in Watershed Delineation, Numerical Modeling and Solute Transport in the Great Basin. Clayton Valley, Nevada

Science.gov (United States)

Underdown, C. G.; Boutt, D. F.; Hynek, S. A.; Munk, L. A.

2017-12-01

Importance of transience in managed groundwater systems is generally determined by timeframe of management decisions. Watersheds with management times shorter than the aquifer (watershed) response time, or the time it takes a watershed to recover from a change in hydrologic state, would not include the new state and are treated as steady-state. However, these watersheds will experience transient response between hydrologic states. Watershed response time is a function of length. Therefore flat, regional watersheds characteristic of the Great Basin have long response times. Defining watershed extents as the area in which the water budget is balanced means inputs equal outputs. Steady-state budgets in the Great Basin have been balanced by extending watershed boundaries to include more area for recharge; however, the length and age of requisite flow paths are poorly constrained and often unrealistic. Inclusion of stored water in hydrologic budget calculations permits water balance within smaller contributing areas. As groundwater flow path lengths, depths, and locations differ between steady-state and transient systems, so do solute transport mechanisms. To observe how transience affects response time and solute transport, a refined (transient) version of the USGS steady-state groundwater flow model of the Great Basin is evaluated. This model is used to assess transient changes in contributing area for Clayton Valley, a lithium-brine producing endorheic basin in southwestern Nevada. Model runs of various recharge, discharge and storage bounds are created from conceptual models based upon historical climate data. Comparing results of the refined model to USGS groundwater observations allows for model validation and comparison against the USGS steady-state model. The transient contributing area to Clayton Valley is 85% smaller than that calculated from the steady-state solution, however several long flow paths important to both water and solute budgets at Clayton Valley

SWAT-based streamflow and embayment modeling of Karst-affected Chapel branch watershed, South Carolina

Science.gov (United States)

Devendra Amatya; M. Jha; A.E. Edwards; T.M. Williams; D.R. Hitchcock

2011-01-01

SWAT is a GIS-based basin-scale model widely used for the characterization of hydrology and water quality of large, complex watersheds; however, SWAT has not been fully tested in watersheds with karst geomorphology and downstream reservoir-like embayment. In this study, SWAT was applied to test its ability to predict monthly streamflow dynamics for a 1,555 ha karst...

Effect of Using Extreme Years in Hydrologic Model Calibration Performance

Science.gov (United States)

Goktas, R. K.; Tezel, U.; Kargi, P. G.; Ayvaz, T.; Tezyapar, I.; Mesta, B.; Kentel, E.

2017-12-01

Hydrological models are useful in predicting and developing management strategies for controlling the system behaviour. Specifically they can be used for evaluating streamflow at ungaged catchments, effect of climate change, best management practices on water resources, or identification of pollution sources in a watershed. This study is a part of a TUBITAK project named "Development of a geographical information system based decision-making tool for water quality management of Ergene Watershed using pollutant fingerprints". Within the scope of this project, first water resources in Ergene Watershed is studied. Streamgages found in the basin are identified and daily streamflow measurements are obtained from State Hydraulic Works of Turkey. Streamflow data is analysed using box-whisker plots, hydrographs and flow-duration curves focusing on identification of extreme periods, dry or wet. Then a hydrological model is developed for Ergene Watershed using HEC-HMS in the Watershed Modeling System (WMS) environment. The model is calibrated for various time periods including dry and wet ones and the performance of calibration is evaluated using Nash-Sutcliffe Efficiency (NSE), correlation coefficient, percent bias (PBIAS) and root mean square error. It is observed that calibration period affects the model performance, and the main purpose of the development of the hydrological model should guide calibration period selection. Acknowledgement: This study is funded by The Scientific and Technological Research Council of Turkey (TUBITAK) under Project Number 115Y064.

Tile drainage as karst: Conduit flow and diffuse flow in a tile-drained watershed

Science.gov (United States)

Schilling, K.E.; Helmers, M.

2008-01-01

The similarity of tiled-drained watersheds to karst drainage basins can be used to improve understanding of watershed-scale nutrient losses from subsurface tile drainage networks. In this study, short-term variations in discharge and chemistry were examined from a tile outlet collecting subsurface tile flow from a 963 ha agricultural watershed. Study objectives were to apply analytical techniques from karst springs to tile discharge to evaluate water sources and estimate the loads of agricultural pollutants discharged from the tile with conduit, intermediate and diffuse flow regimes. A two-member mixing model using nitrate, chloride and specific conductance was used to distinguish rainwater versus groundwater inputs. Results indicated that groundwater comprised 75% of the discharge for a three-day storm period and rainwater was primarily concentrated during the hydrograph peak. A contrasting pattern of solute concentrations and export loads was observed in tile flow. During base flow periods, tile flow consisted of diffuse flow from groundwater sources and contained elevated levels of nitrate, chloride and specific conductance. During storm events, suspended solids and pollutants adhered to soil surfaces (phosphorus, ammonium and organic nitrogen) were concentrated and discharged during the rapid, conduit flow portion of the hydrograph. During a three-day period, conduit flow occurred for 5.6% of the time but accounted for 16.5% of the total flow. Nitrate and chloride were delivered primarily with diffuse flow (more than 70%), whereas 80-94% of total suspended sediment, phosphorus and ammonium were exported with conduit and intermediate flow regimes. Understanding the water sources contributing to tile drainage and the manner by which pollutant discharge occurs from these systems (conduit, intermediate or diffuse flow) may be useful for designing, implementing and evaluating non-point source reduction strategies in tile-drained landscapes. ?? 2007 Elsevier B.V. All

Virgin Islands: Coral Bay Watershed Management (A Former EPA CARE Project)

Science.gov (United States)

The Coral Bay Watershed Management is a recipient of the Level II CARE cooperative agreement to continue and expand its collective efforts to stop erosion, sediment, and storm-water pollution of Coral Bay, improve solid waste management,

Quasi-Empirical and Spatio-Temporal Vulnerability Modeling of Environmental Risks Posed to a Watershed

Science.gov (United States)

Rozario, Papia Faustina

Water quality assessment is crucial in investigating impairment within agricultural watersheds. Seasonal and spatial variations on land can directly affect the adjoining riverine systems. Studies have revealed that agricultural activities are often major contributors to altering water quality of surface waters. A common means of addressing this issue is through the establishment and monitoring the health of riparian vegetation buffers along those areas of stream channels that would be most susceptible to the threat. Remote sensing and Geographic Information Systems (GIS) offer a means by which impaired areas can be identified, so that subsequent action toward the establishment of riparian zones can be taken. Modeling the size and rate of land use and land cover (LULC) change is an effective method of projecting localized impairment. This study presents an integrated model utilizing Analytical Hierarchical Process (AHP), Markov Chain Monte Carlo (MCMC) simulations, and geospatial analyses to address areas of impairment within the Pipestem Creek watershed, a part of the Missouri Watershed James Sub-region of North Dakota, USA. The rate and direction of LULC change was analyzed through this model and its impact on the ambient water and soil quality was studied. Tasseled Cap Greenness Index (TCGI) was used to determine the loss of forested land within the watershed from 1976 to 2015. Research results validated temporal and spatial relations of LULC dynamics to nutrient concentrations especially those that would be noted at the mouth of the watershed. It was found that the levels of Total Dissolved Solids (TDS) were much higher for the years 2014 to 2016 with a discernible increased localized alkalizing effect within the watershed. Fallow areas were seen to produce significant amounts of sediment loads from the sub-watershed. LULC distribution from 2007 to 2015 show that it is possible to project future land use change patterns. About 89.90% likelihood of increment in

One multi-media environmental system with linkage between meteorology/ hydrology/ air quality models and water quality model

Science.gov (United States)

Tang, C.; Lynch, J. A.; Dennis, R. L.

2016-12-01

The biogeochemical processing of nitrogen and associated pollutants is driven by meteorological and hydrological processes in conjunction with pollutant loading. There are feedbacks between meteorology and hydrology that will be affected by land-use change and climate change. Changes in meteorology will affect pollutant deposition. It is important to account for those feedbacks and produce internally consistent simulations of meteorology, hydrology, and pollutant loading to drive the (watershed/water quality) biogeochemical models. In this study, the ecological response to emission reductions in streams in the Potomac watershed was evaluated. Firstly, we simulated the deposition by using the fully coupled Weather Research & Forecasting (WRF) model and the Community Multiscale Air Quality (CAMQ) model; secondly, we created the hydrological data by the offline linked Variable Infiltration Capacity (VIC) model and the WRF model. Lastly, we investigated the water quality by one comprehensive/environment model, namely the linkage of CMAQ, WRF, VIC and the Model of Acidification of Groundwater In Catchment (MAGIC) model from 2002 to 2010.The simulated results (such as NO3, SO4, and SBC) fit well to the observed values. The linkage provides a generally accurate, well-tested tool for evaluating sensitivities to varying meteorology and environmental changes on acidification and other biogeochemical processes, with capability to comprehensively explore strategic policy and management design.

Agricultural Policy Environmental eXtender Simulation of Three Adjacent Row-Crop Watersheds in the Claypan Region.

Science.gov (United States)

Anomaa Senaviratne, G M M M; Udawatta, Ranjith P; Baffaut, Claire; Anderson, Stephen H

2013-01-01

The Agricultural Policy Environmental Extender (APEX) model is used to evaluate best management practices on pollutant loading in whole farms or small watersheds. The objectives of this study were to conduct a sensitivity analysis to determine the effect of model parameters on APEX output and use the parameterized, calibrated, and validated model to evaluate long-term benefits of grass waterways. The APEX model was used to model three (East, Center, and West) adjacent field-size watersheds with claypan soils under a no-till corn ( L.)/soybean [ (L.) Merr.] rotation. Twenty-seven parameters were sensitive for crop yield, runoff, sediment, nitrogen (dissolved and total), and phosphorous (dissolved and total) simulations. The model was calibrated using measured event-based data from the Center watershed from 1993 to 1997 and validated with data from the West and East watersheds. Simulated crop yields were within ±13% of the measured yield. The model performance for event-based runoff was excellent, with calibration and validation > 0.9 and Nash-Sutcliffe coefficients (NSC) > 0.8, respectively. Sediment and total nitrogen calibration results were satisfactory for larger rainfall events (>50 mm), with > 0.5 and NSC > 0.4, but validation results remained poor, with NSC between 0.18 and 0.3. Total phosphorous was well calibrated and validated, with > 0.8 and NSC > 0.7, respectively. The presence of grass waterways reduced annual total phosphorus loadings by 13 to 25%. The replicated study indicates that APEX provides a convenient and efficient tool to evaluate long-term benefits of conservation practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Beyond formal groups: neighboring acts and watershed protection in Appalachia

Directory of Open Access Journals (Sweden)

Heather Lukacs

2016-09-01

Full Text Available This paper explores how watershed organizations in Appalachia have persisted in addressing water quality issues in areas with a history of coal mining. We identified two watershed groups that have taken responsibility for restoring local creeks that were previously highly degraded and sporadically managed. These watershed groups represent cases of self-organized commons governance in resource-rich, economically poor Appalachian communities. We describe the extent and characteristics of links between watershed group volunteers and watershed residents who are not group members. Through surveys, participant observation, and key-informant consultation, we found that neighbors – group members as well as non-group-members – supported the group's function through informal neighboring acts. Past research has shown that local commons governance institutions benefit from being nested in supportive external structures. We found that the persistence and success of community watershed organizations depends on the informal participation of local residents, affirming the necessity of looking beyond formal, organized groups to understand the resources, expertise, and information needed to address complex water pollution at the watershed level. Our findings augment the concept of nestedness in commons governance to include that of a formal organization acting as a neighbor that exchanges informal neighboring acts with local residents. In this way, we extend the concept of neighboring to include interactions between individuals and a group operating in the same geographic area.

Participatory Modeling Processes to Build Community Knowledge Using Shared Model and Data Resources and in a Transboundary Pacific Northwest Watershed (Nooksack River Basin, Washington, USA)

Science.gov (United States)

Bandaragoda, C.; Dumas, M.

2014-12-01

As with many western US watersheds, the Nooksack River Basin faces strong pressures associated with climate variability and change, rapid population growth, and deep-rooted water law. This transboundary basin includes contributing areas in British Columbia, Canada, and has a long history of joint data collection, model development, and facilitated communication between governmental (federal, tribal, state, local), environmental, timber, agricultural, and recreational user groups. However, each entity in the watershed responds to unique data coordination, information sharing, and adaptive management regimes and thresholds, further increasing the complexity of watershed management. Over the past four years, participatory methods were used to compile and review scientific data and models, including fish habitat (endangered salmonid species), channel hydraulics, climate data, agricultural, municipal and industrial water use, and integrated watershed scale distributed hydrologic models from over 15 years of projects (from jointly funded to independent shared work by individual companies, agencies, and universities). A specific outcome of the work includes participatory design of a collective problem statement used for guidance on future investment of shared resources and development of a data-generation process where modeling results are communicated in a three-tiers for 1) public/decision-making, 2) technical, and 3) research audiences. We establish features for successful participation using tools that are iteratively developed, tested for usability through incremental knowledge building, and designed to provide rigor in modeling. A general outcome of the work is ongoing support by tribal, state, and local governments, as well as the agricultural community, to continue the generation of shared watershed data using models in a dynamic legal and regulatory setting, where two federally recognized tribes have requested federal court resolution of federal treaty rights

Air Pollution Modeling at Road Sides Using the Operational Street Pollution Model-A Case Study in Hanoi, Vietnam

DEFF Research Database (Denmark)

Hung, Ngo Tho; Ketzel, Matthias; Jensen, Steen Solvang

2010-01-01

In many metropolitan areas, traffic is the main source of air pollution. The high concentrations of pollutants in streets have the potential to affect human health. Therefore, estimation of air pollution at the street level is required for health impact assessment. This task has been carried out...... in many developed countries by a combination of air quality measurements and modeling. This study focuses on how to apply a dispersion model to cities in the developing world, where model input data and data from air quality monitoring stations are limited or of varying quality. This research uses...... the operational street pollution model (OSPM) developed by the National Environmental Research Institute in Denmark for a case study in Hanoi, the capital of Vietnam. OSPM predictions from five streets were evaluated against air pollution measurements of nitrogen oxides (NO), sulfur dioxide (SO2), carbon monoxide...

Long-term modeling of soil C erosion and sequestration at the small watershed scale

International Nuclear Information System (INIS)

Izaurralde, R.C.; Thomson, A.M.; Williams, J.R.; Post, W.M.; McGill, W.B.; Owens, L.B.; Lal, R.

2007-01-01

The soil C balance is determined by the difference between inputs (e.g., plant litter, organic amendments, depositional C) and outputs (e.g., soil respiration, dissolved organic C leaching, and eroded C). There is a need to improve our understanding of whether soil erosion is a sink or a source of atmospheric CO2. The objective of this paper is to discover the long-term influence of soil erosion on the C cycle of managed watersheds near Coshocton, OH. We hypothesize that the amount of eroded C that is deposited in or out of a watershed compares in magnitude to the soil C changes induced via microbial respiration. We applied the erosion productivity impact calculator (EPIC) model to evaluate the role of erosion-deposition processes on the C balance of three small watersheds (∼1 ha). Experimental records from the USDA North Appalachian Experimental Watershed facility north of Coshocton, OH were used in the study. Soils are predominantly silt loam and have developed from loess-like deposits over residual bedrock. Management practices in the three watersheds have changed over time. Currently, watershed 118 (W118) is under a corn (Zea mays L.)-soybean (Glycine max [L.] Merr.) no till rotation, W128 is under conventional till continuous corn, and W188 is under no till continuous corn. Simulations of a comprehensive set of ecosystem processes including plant growth, runoff, and water erosion were used to quantify sediment C yields. A simulated sediment C yield of 43 ± 22 kg C ha -1 year -1 compared favorably against the observed 31 ± 12 kg C ha -1 year -1 in W118. EPIC overestimated the soil C stock in the top 30-cm soil depth in W118 by 21% of the measured value (36.8 Mg C ha -1 ). Simulations of soil C stocks in the other two watersheds (42.3 Mg C ha -1 in W128 and 50.4 Mg C ha -1 in W188) were off by -1 . Simulated eroded C re-deposited inside (30-212 kg C ha -1 year -1 ) or outside (73 -1 79 kg C ha -1 year -1 ) watershed boundaries compared in magnitude to a

An export coefficient based inexact fuzzy bi-level multi-objective programming model for the management of agricultural nonpoint source pollution under uncertainty

Science.gov (United States)

Cai, Yanpeng; Rong, Qiangqiang; Yang, Zhifeng; Yue, Wencong; Tan, Qian

2018-02-01

In this research, an export coefficient based inexact fuzzy bi-level multi-objective programming (EC-IFBLMOP) model was developed through integrating export coefficient model (ECM), interval parameter programming (IPP) and fuzzy parameter programming (FPP) within a bi-level multi-objective programming framework. The proposed EC-IFBLMOP model can effectively deal with the multiple uncertainties expressed as discrete intervals and fuzzy membership functions. Also, the complexities in agricultural systems, such as the cooperation and gaming relationship between the decision makers at different levels, can be fully considered in the model. The developed model was then applied to identify the optimal land use patterns and BMP implementing levels for agricultural nonpoint source (NPS) pollution management in a subcatchment in the upper stream watershed of the Miyun Reservoir in north China. The results of the model showed that the desired optimal land use patterns and implementing levels of best management of practices (BMPs) would be obtained. It is the gaming result between the upper- and lower-level decision makers, when the allowable discharge amounts of NPS pollutants were limited. Moreover, results corresponding to different decision scenarios could provide a set of decision alternatives for the upper- and lower-level decision makers to identify the most appropriate management strategy. The model has a good applicability and can be effectively utilized for agricultural NPS pollution management.

Pathogen Transport and Fate Modeling in the Upper Salem River Watershed Using SWAT Model

Science.gov (United States)

SWAT (Soil and Water Assessment Tool) is a dynamic watershed model that is applied to simulate the impact of land management practices on water quality over a continuous period. The Upper Salem River, located in Salem County New Jersey, is listed by the New Jersey Department of ...

Characterization of coastal urban watershed bacterial communities leads to alternative community-based indicators

Energy Technology Data Exchange (ETDEWEB)

Wu, C.H.; Sercu, B.; Van De Werhorst, L.C.; Wong, J.; DeSantis, T.Z.; Brodie, E.L.; Hazen, T.C.; Holden, P.A.; Andersen, G.L.

2010-03-01

Microbial communities in aquatic environments are spatially and temporally dynamic due to environmental fluctuations and varied external input sources. A large percentage of the urban watersheds in the United States are affected by fecal pollution, including human pathogens, thus warranting comprehensive monitoring. Using a high-density microarray (PhyloChip), we examined water column bacterial community DNA extracted from two connecting urban watersheds, elucidating variable and stable bacterial subpopulations over a 3-day period and community composition profiles that were distinct to fecal and non-fecal sources. Two approaches were used for indication of fecal influence. The first approach utilized similarity of 503 operational taxonomic units (OTUs) common to all fecal samples analyzed in this study with the watershed samples as an index of fecal pollution. A majority of the 503 OTUs were found in the phyla Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. The second approach incorporated relative richness of 4 bacterial classes (Bacilli, Bacteroidetes, Clostridia and a-proteobacteria) found to have the highest variance in fecal and non-fecal samples. The ratio of these 4 classes (BBC:A) from the watershed samples demonstrated a trend where bacterial communities from gut and sewage sources had higher ratios than from sources not impacted by fecal material. This trend was also observed in the 124 bacterial communities from previously published and unpublished sequencing or PhyloChip- analyzed studies. This study provided a detailed characterization of bacterial community variability during dry weather across a 3-day period in two urban watersheds. The comparative analysis of watershed community composition resulted in alternative community-based indicators that could be useful for assessing ecosystem health.

The modified SWAT model for predicting fecal coliforms in the Wachusett Reservoir Watershed, USA.

Science.gov (United States)

Cho, Kyung Hwa; Pachepsky, Yakov A; Kim, Joon Ha; Kim, Jung-Woo; Park, Mi-Hyun

2012-10-01

This study assessed fecal coliform contamination in the Wachusett Reservoir Watershed in Massachusetts, USA using Soil and Water Assessment Tool (SWAT) because bacteria are one of the major water quality parameters of concern. The bacteria subroutine in SWAT, considering in-stream bacteria die-off only, was modified in this study to include solar radiation-associated die-off and the contribution of wildlife. The result of sensitivity analysis demonstrates that solar radiation is one of the most significant fate factors of fecal coliform. A water temperature-associated function to represent the contribution of beaver activity in the watershed to fecal contamination improved prediction accuracy. The modified SWAT model provides an improved estimate of bacteria from the watershed. Our approach will be useful for simulating bacterial concentrations to provide predictive and reliable information of fecal contamination thus facilitating the implementation of effective watershed management. Copyright © 2012 Elsevier Ltd. All rights reserved.

Modeling of atmospheric pollutant transfers

International Nuclear Information System (INIS)

Jourdain, F.

2007-01-01

Modeling is today a common tool for the evaluation of the environmental impact of atmospheric pollution events, for the design of air monitoring networks or for the calculation of pollutant concentrations in the ambient air. It is even necessary for the a priori evaluation of the consequences of a pollution plume. A large choice of atmospheric transfer codes exist but no ideal tool is available which allows to model all kinds of situations. The present day approach consists in combining different types of modeling according to the requested results and simulations. The CEA has a solid experience in this domain and has developed independent tools for the impact and safety studies relative to industrial facilities and to the management of crisis situations. (J.S.)

Characterizing mercury concentrations and fluxes in a Coastal Plain watershed: Insights from dynamic modeling and data

Science.gov (United States)

Golden, H.E.; Knightes, C.D.; Conrads, P.A.; Davis, G.M.; Feaster, T.D.; Journey, C.A.; Benedict, S.T.; Brigham, M.E.; Bradley, P.M.

2012-01-01

Mercury (Hg) is one of the leading water quality concerns in surface waters of the United States. Although watershed-scale Hg cycling research has increased in the past two decades, advances in modeling watershed Hg processes in diverse physiographic regions, spatial scales, and land cover types are needed. The goal of this study was to assess Hg cycling in a Coastal Plain system using concentrations and fluxes estimated by multiple watershed-scale models with distinct mathematical frameworks reflecting different system dynamics. We simulated total mercury (HgT, the sum of filtered and particulate forms) concentrations and fluxes from a Coastal Plain watershed (McTier Creek) using three watershed Hg models and an empirical load model. Model output was compared with observed in-stream HgT. We found that shallow subsurface flow is a potentially important transport mechanism of particulate HgT during periods when connectivity between the uplands and surface waters is maximized. Other processes (e.g., stream bank erosion, sediment re-suspension) may increase particulate HgT in the water column. Simulations and data suggest that variable source area (VSA) flow and lack of rainfall interactions with surface soil horizons result in increased dissolved HgT concentrations unrelated to DOC mobilization following precipitation events. Although flushing of DOC-HgT complexes from surface soils can also occur during this period, DOC-complexed HgT becomes more important during base flow conditions. TOPLOAD simulations highlight saturated subsurface flow as a primary driver of daily HgT loadings, but shallow subsurface flow is important for HgT loads during high-flow events. Results suggest limited seasonal trends in HgT dynamics.

Watershed restoration through remining in the Tangascootack Creek Watershed, Clinton County, Pennsylvania

International Nuclear Information System (INIS)

Skema, V.W.; Smith, M.W.; Bisko, D.C.; Dimatteo, M.

1998-01-01

The Pennsylvania Department of Environmental Protection and the Pennsylvania Geologic Survey are working together to remediate the effects of acid mine drainage. Remining of previously mined areas is a key component of a comprehensive strategy of improving water quality in polluted watersheds. In this new approach sites will be carefully selected on the basis of remaining coal reserves and overburden characteristics. One of the first watersheds targeted was the Tangascootack Creek watershed located in Clinton County near Lock Haven. The Geologic Survey agreed to provide geologic and coal resource maps for this previously unmapped area. This involved conducting field work examining rock exposures. Five cored holes were drilled, and core was examined to develop a geologic framework. Coals from these holes and from highwalls were chemically tested. Strata overlying the coal seams were analyzed using acid base accounting to determine their potential for generating acidity as well as alkalinity. Additional drill hole data and chemical analyses were collected from cooperating mining companies. This information was used to produce a geologic map showing coal crop lines and structure, coal thickness maps, mined-out area maps, overburden thickness maps, overburden geochemistry maps, strip ratio maps, and to estimate the extent of remaining coal reserves. Several significant geologic features were found in the course of mapping the watershed. One is the extreme variability in coal thickness and character of overburden rock. Another is the degree of relief found to be present on the Mississippian-Pennsylvanian unconformity. It is believed that this feature plays an important role in coal and high aluminum flint clay distribution regionally. And finally is the thick occurrence of Loyalhanna Formation calcareous sandstone which is providing a natural source of carbonate for the neutralization of acid mine drainage

Improving student comprehension of the interconnectivity of the hydrologic cycle with a novel 'hydrology toolbox', integrated watershed model, and companion textbook

Science.gov (United States)

Huning, L. S.; Margulis, S. A.

2013-12-01

Concepts in introductory hydrology courses are often taught in the context of process-based modeling that ultimately is integrated into a watershed model. In an effort to reduce the learning curve associated with applying hydrologic concepts to real-world applications, we developed and incorporated a 'hydrology toolbox' that complements a new, companion textbook into introductory undergraduate hydrology courses. The hydrology toolbox contains the basic building blocks (functions coded in MATLAB) for an integrated spatially-distributed watershed model that makes hydrologic topics (e.g. precipitation, snow, radiation, evaporation, unsaturated flow, infiltration, groundwater, and runoff) more user-friendly and accessible for students. The toolbox functions can be used in a modular format so that students can study individual hydrologic processes and become familiar with the hydrology toolbox. This approach allows such courses to emphasize understanding and application of hydrologic concepts rather than computer coding or programming. While topics in introductory hydrology courses are often introduced and taught independently or semi-independently, they are inherently interconnected. These toolbox functions are therefore linked together at the end of the course to reinforce a holistic understanding of how these hydrologic processes are measured, interconnected, and modeled. They are integrated into a spatially-distributed watershed model or numerical laboratory where students can explore a range of topics such as rainfall-runoff modeling, urbanization, deforestation, watershed response to changes in parameters or forcings, etc. Model output can readily be visualized and analyzed by students to understand watershed response in a real river basin or a simple 'toy' basin. These tools complement the textbook, each of which has been well received by students in multiple hydrology courses with various disciplinary backgrounds. The same governing equations that students have

Impact of Yangtze river water transfer on the water quality of the Lixia river watershed, China.

Directory of Open Access Journals (Sweden)

Xiaoxue Ma

Full Text Available To improve water quality and reduce the negative impacts of sudden inputs of water pollution in the Lixia River watershed, China, a series of experimental water transfers from the Yangtze River to the Lixia River were conducted from 2 December 2006 to 7 January 2007. Water samples were collected every six days at 55 monitoring sites during this period. Eight water parameters (water temperature, pH, dissolved oxygen (DO, chemical oxygen demand (COD, potassium permanganate index (CODMn, ammonia nitrogen (NH4+-N, electrical conductivity (EC, and water transparency (WT were analyzed to determine changes in nutrient concentrations during water transfers. The comprehensive pollution index (Pi and single-factor (Si evaluation methods were applied to evaluate spatio-temporal patterns of water quality during water transfers. Water quality parameters displayed different spatial and temporal distribution patterns within the watershed. Water quality was improved significantly by the water transfers, especially for sites closer to water intake points. The degree of improvement is positively related to rates of transfer inflow and drainage outflow. The effects differed for different water quality parameters at each site and at different water transfer times. There were notable decreases in NH4+-N, DO, COD, and CODMn across the entire watershed. However, positive effects on EC and pH were not observed. It is concluded that freshwater transfers from the Yangtze River can be used as an emergency measure to flush pollutants from the Lixia River watershed. Improved understanding of the effects of water transfers on water quality can help the development and implementation of effective strategies to improve water quality within this watershed.

Small Reservoir Impact on Simulated Watershed-Scale Nutrient Yield

Directory of Open Access Journals (Sweden)

Shane J. Prochnow

2007-01-01

Full Text Available The soil and water assessment tool (SWAT is used to assess the influence of small upland reservoirs (PL566 on watershed nutrient yield. SWAT simulates the impact of collectively increasing and decreasing PL566 magnitudes (size parameters on the watershed. Totally removing PL566 reservoirs results in a 100% increase in total phosphorus and an 82% increase in total nitrogen, while a total maximum daily load (TMDL calling for a 50% reduction in total phosphorus can be achieved with a 500% increase in the magnitude of PL566s in the watershed. PL566 reservoirs capture agriculture pollution in surface flow, providing long-term storage of these constituents when they settle to the reservoir beds. A potential strategy to reduce future downstream nutrient loading is to enhance or construct new PL566 reservoirs in the upper basin to better capture agricultural runoff.

Pollution externalities in a Schumpeterian growth model

OpenAIRE

Koesler, Simon

2010-01-01

This paper extends a standard Schumpeterian growth model to include an environmental dimension. Thereby, it explicitly links the pollution intensity of economic activity to technological progress. In a second step, it investigates the effect of pollution on economic growth under the assumption that pollution intensities are related to technological progress. Several conclusions emerge from the model. In equilibrium, the economy follows a balanced growth path. The effect of pollution on the ec...

Spatially-Distributed Stream Flow and Nutrient Dynamics Simulations Using the Component-Based AgroEcoSystem-Watershed (AgES-W) Model

Science.gov (United States)

Ascough, J. C.; David, O.; Heathman, G. C.; Smith, D. R.; Green, T. R.; Krause, P.; Kipka, H.; Fink, M.

2010-12-01

The Object Modeling System 3 (OMS3), currently being developed by the USDA-ARS Agricultural Systems Research Unit and Colorado State University (Fort Collins, CO), provides a component-based environmental modeling framework which allows the implementation of single- or multi-process modules that can be developed and applied as custom-tailored model configurations. OMS3 as a “lightweight” modeling framework contains four primary foundations: modeling resources (e.g., components) annotated with modeling metadata; domain specific knowledge bases and ontologies; tools for calibration, sensitivity analysis, and model optimization; and methods for model integration and performance scalability. The core is able to manage modeling resources and development tools for model and simulation creation, execution, evaluation, and documentation. OMS3 is based on the Java platform but is highly interoperable with C, C++, and FORTRAN on all major operating systems and architectures. The ARS Conservation Effects Assessment Project (CEAP) Watershed Assessment Study (WAS) Project Plan provides detailed descriptions of ongoing research studies at 14 benchmark watersheds in the United States. In order to satisfy the requirements of CEAP WAS Objective 5 (“develop and verify regional watershed models that quantify environmental outcomes of conservation practices in major agricultural regions”), a new watershed model development approach was initiated to take advantage of OMS3 modeling framework capabilities. Specific objectives of this study were to: 1) disaggregate and refactor various agroecosystem models (e.g., J2K-S, SWAT, WEPP) and implement hydrological, N dynamics, and crop growth science components under OMS3, 2) assemble a new modular watershed scale model for fully-distributed transfer of water and N loading between land units and stream channels, and 3) evaluate the accuracy and applicability of the modular watershed model for estimating stream flow and N dynamics. The

Application of a virtual watershed in academic education

Directory of Open Access Journals (Sweden)

A. L. Horn

2005-01-01

Full Text Available Hydrologic models of watersheds often represent complex systems which are difficult to understand regarding to their structure and dynamics. Virtual watersheds, i.e. watersheds which exist only in the virtual reality of a computer system, are an approach to simplify access to this real-world complexity. In this study we present the virtual watershed KIELSHED-1, a 117 km2 v-shaped valley with grassland on a "Cambisol" soil type. Two weather scenarios are delivered with the watershed: a simplified artificial weather scenario based on long-term data of a German weather station as well as an unmodified data record. The input data and parameters are compiled according to the conventions of the SWAT 2000 hydrological model. KIELSHED-1 is mainly used for education, and illustrative application examples, i.e. calculation of water balance, model calibration, development of land use scenarios, give an insight to the capabilities of the virtual watershed.

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

Science.gov (United States)

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.

Development and evaluation of a watershed-scale hybrid hydrologic model

OpenAIRE

Cho, Younghyun

2016-01-01

A watershed-scale hybrid hydrologic model (Distributed-Clark), which is a lumped conceptual and distributed feature model, was developed to predict spatially distributed short- and long-term rainfall runoff generation and routing using relatively simple methodologies and state-of-the-art spatial data in a GIS environment. In Distributed-Clark, spatially distributed excess rainfall estimated with the SCS curve number method and a GIS-based set of separated unit hydrographs (spatially distribut...

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

Science.gov (United States)

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.

Long-term modeling of soil C erosion and sequestration at the small watershed scale

Energy Technology Data Exchange (ETDEWEB)

Izaurralde, R.C.; Thomson, A.M. [The Joint Global Change Research Institute, 8400 Baltimore Avenue, Suite 201, College Park, MD 20740-2496 (United States); Williams, J.R. [Blacklands Research Center, Texas A and M University, 808 East Blacklands Road, Temple, TX 76502 (United States); Post, W.M. [Oak Ridge National Laboratory, Building 1509, Bethel Valley Road, PO Box 2008 MS6335, Oak Ridge, TN 537831-6335 (United States); McGill, W.B. [College of Science and Management, University of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9 (Canada); Owens, L.B. [North Appalachian Experimental Watershed, USDA-Agricultural Research Station, 28850 SR 621, Coshocton, OH 43812-0488 (United States); Lal, R. [School of Natural Resources Food, Agricultural and Environmental Sciences, The Ohio State University, 422B Kottman Hall, 2021 Coffey Road, Columbus, OH 43210 (United States)

2007-01-15

The soil C balance is determined by the difference between inputs (e.g., plant litter, organic amendments, depositional C) and outputs (e.g., soil respiration, dissolved organic C leaching, and eroded C). There is a need to improve our understanding of whether soil erosion is a sink or a source of atmospheric CO2. The objective of this paper is to discover the long-term influence of soil erosion on the C cycle of managed watersheds near Coshocton, OH. We hypothesize that the amount of eroded C that is deposited in or out of a watershed compares in magnitude to the soil C changes induced via microbial respiration. We applied the erosion productivity impact calculator (EPIC) model to evaluate the role of erosion-deposition processes on the C balance of three small watersheds ({approx}1 ha). Experimental records from the USDA North Appalachian Experimental Watershed facility north of Coshocton, OH were used in the study. Soils are predominantly silt loam and have developed from loess-like deposits over residual bedrock. Management practices in the three watersheds have changed over time. Currently, watershed 118 (W118) is under a corn (Zea mays L.)-soybean (Glycine max [L.] Merr.) no till rotation, W128 is under conventional till continuous corn, and W188 is under no till continuous corn. Simulations of a comprehensive set of ecosystem processes including plant growth, runoff, and water erosion were used to quantify sediment C yields. A simulated sediment C yield of 43 {+-} 22 kg C ha{sup -1} year{sup -1} compared favorably against the observed 31 {+-} 12 kg C ha{sup -1} year{sup -1} in W118. EPIC overestimated the soil C stock in the top 30-cm soil depth in W118 by 21% of the measured value (36.8 Mg C ha{sup -1}). Simulations of soil C stocks in the other two watersheds (42.3 Mg C ha{sup -1} in W128 and 50.4 Mg C ha{sup -1} in W188) were off by <1 Mg C ha{sup -1}. Simulated eroded C re-deposited inside (30-212 kg C ha{sup -1} year{sup -1}) or outside (73{sup -1}79 kg

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

Science.gov (United States)

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.

Minnesota Watersheds

Data.gov (United States)

Minnesota Department of Natural Resources — Statewide minor watershed delineations with major/minor watershed identifiers and names for provinces, major watersheds, and basins. Also included are watershed...

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

Science.gov (United States)

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.

A Diagnostic Decision Support System for BMP Selection in Small Urban Watersheds

Science.gov (United States)

Wang, Y.; Montas, H. J.; Leisnham, P.; Shirmohammadi, A.; Brubaker, K. L.; Reiling, S.

2013-12-01

Overall water quality in the United States has improved since the establishment of the Clean Water Act in 1972. While waste water and other point source discharge treatments are expanding and improving in quality, non-point source pollution remains a problem. Best Management Practices (BMPs) are structural and nonstructural methods to mitigate these problems. Much attention has focused on non-point source pollutants in rural areas, where agricultural activities increase the nutrients (fertilizers), toxics (pesticides), and sediments in surface water. Urban and suburban areas also suffer from severe water quantity and quality problems, largely due to stormwater. Low Impact Development (LID), a series of spatially distributed and engineered small-scale hydrologic controls, is an appropriate approach to reduce flow rate and improve urban stormwater quality before it discharges into surface water bodies. This research sought to develop a Diagnostic Decision Support System (DDSS) for urban BMP/LID selection. The process-based hydrologic model, Soil and Water Assessment Tool (SWAT), was used to simulate the hydrologic processes and to estimate related water quality variables. A logic based simple method was developed to identify the critical water quality and quantity hotspots using the SWAT outputs for multiple Hydrologic Response Units (HRUs) within the study watershed. The DDSS consisted of two parts: a Diagnostic Expert System (DES), which identifies the most likely reasons for excessive pollutants; and a Prescriptive Expert System (PES), which selects the best set of spatially distributed BMPs. The DDSS is tested in Watts Branch, a small urban subwatershed in metropolitan Washington D.C. A SWAT model for the watershed was calibrated and validated first. The DDSS was then applied. The final selected series of BMPs was simulated again in the SWAT model for a ten-year period to quantify their effectiveness. The identified hotspots, possible reasons, and BMP solutions

Subtask 1.18 - A Decision Tool for Watershed-Based Effluent Trading

Energy Technology Data Exchange (ETDEWEB)

Xixi Wang; Bethany A. Kurz; Marc D. Kurz

2006-11-30

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

Development, calibration, and analysis of a hydrologic and water-quality model of the Delaware Inland Bays watershed

Science.gov (United States)

Gutierrez-Magness, Angelica L.; Raffensperger, Jeff P.

2003-01-01

Excessive nutrients and sediment are among the most significant environmental stressors in the Delaware Inland Bays (Rehoboth, Indian River, and Little Assawoman Bays). Sources of nutrients, sediment, and other contaminants within the Inland Bays watershed include point-source discharges from industries and wastewater-treatment plants, runoff and infiltration to ground water from agricultural fields and poultry operations, effluent from on-site wastewater disposal systems, and atmospheric deposition. To determine the most effective restoration methods for the Inland Bays, it is necessary to understand the relative distribution and contribution of each of the possible sources of nutrients, sediment, and other contaminants. A cooperative study involving the Delaware Department of Natural Resources and Environmental Control, the Delaware Geological Survey, and the U.S. Geological Survey was initiated in 2000 to develop a hydrologic and water-quality model of the Delaware Inland Bays watershed that can be used as a water-resources planning and management tool. The model code Hydrological Simulation Program - FORTRAN (HSPF) was used. The 719-square-kilometer watershed was divided into 45 model segments, and the model was calibrated using streamflow and water-quality data for January 1999 through April 2000 from six U.S. Geological Survey stream-gaging stations within the watershed. Calibration for some parameters was accomplished using PEST, a model-independent parameter estimator. Model parameters were adjusted systematically so that the discrepancies between the simulated values and the corresponding observations were minimized. Modeling results indicate that soil and aquifer permeability, ditching, dominant land-use class, and land-use practices affect the amount of runoff, the mechanism or flow path (surface flow, interflow, or base flow), and the loads of sediment and nutrients. In general, the edge-of-stream total suspended solids yields in the Inland Bays

Watershed-scale evaluation of the Water Erosion Prediction Project (WEPP) model in the Lake Tahoe basin

Science.gov (United States)

Erin S. Brooks; Mariana Dobre; William J. Elliot; Joan Q. Wu; Jan Boll

2016-01-01

Forest managers need methods to evaluate the impacts of management at the watershed scale. The Water Erosion Prediction Project (WEPP) has the ability to model disturbed forested hillslopes, but has difficulty addressing some of the critical processes that are important at a watershed scale, including baseflow and water yield. In order to apply WEPP to...

Exchanges across land-water-scape boundaries in urban systems: strategies for reducing nitrate pollution.

Science.gov (United States)

Cadenasso, M L; Pickett, S T A; Groffman, P M; Band, L E; Brush, G S; Galvin, M F; Grove, J M; Hagar, G; Marshall, V; McGrath, B P; O'Neil-Dunne, J P M; Stack, W P; Troy, A R

2008-01-01

Conservation in urban areas typically focuses on biodiversity and large green spaces. However, opportunities exist throughout urban areas to enhance ecological functions. An important function of urban landscapes is retaining nitrogen thereby reducing nitrate pollution to streams and coastal waters. Control of nonpoint nitrate pollution in urban areas was originally based on the documented importance of riparian zones in agricultural and forested ecosystems. The watershed and boundary frameworks have been used to guide stream research and a riparian conservation strategy to reduce nitrate pollution in urban streams. But is stream restoration and riparian-zone conservation enough? Data from the Baltimore Ecosystem Study and other urban stream research indicate that urban riparian zones do not necessarily prevent nitrate from entering, nor remove nitrate from, streams. Based on this insight, policy makers in Baltimore extended the conservation strategy throughout larger watersheds, attempting to restore functions that no longer took place in riparian boundaries. Two urban revitalization projects are presented as examples aimed at reducing nitrate pollution to stormwater, streams, and the Chesapeake Bay. An adaptive cycle of ecological urban design synthesizes the insights from the watershed and boundary frameworks, from new data, and from the conservation concerns of agencies and local communities. This urban example of conservation based on ameliorating nitrate water pollution extends the initial watershed-boundary approach along three dimensions: 1) from riparian to urban land-water-scapes; 2) from discrete engineering solutions to ecological design approaches; and 3) from structural solutions to inclusion of individual, household, and institutional behavior.

Metamodeling as a tool to size vegetative filter strips for surface runoff pollution control in European watersheds.

Science.gov (United States)

Lauvernet, Claire; Muñoz-Carpena, Rafael; Carluer, Nadia

2015-04-01

In Europe, a significant presence of contaminants is found in surface water, partly due to pesticide applications. Vegetative filter strips or buffer zones (VFS), often located along rivers, are a common best management practice (BMP) to reduce non point source pollution of water by reducing surface runoff. However, they need to be adapted to the agro-ecological and climatic conditions, both in terms of position and size, in order to be efficient. The TOPPS-PROWADIS project involves European experts and stakeholders to develop and recommend BMPs to reduce pesticide transfer by drift or runoff in several European countries. In this context, IRSTEA developed a guide accompanying the use of different tools, which allows designing site-specific VFS by simulating their efficiency to limit transfers using the mechanistic model VFSMOD. This method which is very complete assumes that the user provides detailed field knowledge and data, which are not always easily available. The aim of this study is to assist the buffer sizing by using a unique tool with a reduced set of parameters, adapted to the available information from the end-users. In order to fill in the lack of real data in many practical applications, a set of virtual scenarios was selected to encompass a large range of agro-pedo-climatic conditions in Europe, considering both the upslope agricultural field and the VFS characteristics. As a first step first, in this work we present scenarios based on North-West of France climate consisting of different rainfall intensities and durations, hillslope lengths and slopes, humidity conditions, a large set of field rainfall/runoff characteristics for the contributing area, and several shallow water table depths and soil types for the VFS. The sizing method based on the mechanistic model VFSMOD was applied for all these scenarios, and a global sensitivity analysis (GSA) of the VFS optimal length was performed for all the input parameters in order to understand their

Mathematical models for atmospheric pollutants. Final report

International Nuclear Information System (INIS)

Drake, R.L.; Barrager, S.M.

1979-08-01

The present and likely future roles of mathematical modeling in air quality decisions are described. The discussion emphasizes models and air pathway processes rather than the chemical and physical behavior of specific anthropogenic emissions. Summarized are the characteristics of various types of models used in the decision-making processes. Specific model subclasses are recommended for use in making air quality decisions that have site-specific, regional, national, or global impacts. The types of exposure and damage models that are currently used to predict the effects of air pollutants on humans, other animals, plants, ecosystems, property, and materials are described. The aesthetic effects of odor and visibility and the impact of pollutants on weather and climate are also addressed. Technical details of air pollution meteorology, chemical and physical properties of air pollutants, solution techniques, and air quality models are discussed in four appendices bound in separate volumes

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

Science.gov (United States)

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.

Spatial multiobjective optimization of agricultural conservation practices using a SWAT model and an evolutionary algorithm.

Science.gov (United States)

Rabotyagov, Sergey; Campbell, Todd; Valcu, Adriana; Gassman, Philip; Jha, Manoj; Schilling, Keith; Wolter, Calvin; Kling, Catherine

2012-12-09

Finding the cost-efficient (i.e., lowest-cost) ways of targeting conservation practice investments for the achievement of specific water quality goals across the landscape is of primary importance in watershed management. Traditional economics methods of finding the lowest-cost solution in the watershed context (e.g.,(5,12,20)) assume that off-site impacts can be accurately described as a proportion of on-site pollution generated. Such approaches are unlikely to be representative of the actual pollution process in a watershed, where the impacts of polluting sources are often determined by complex biophysical processes. The use of modern physically-based, spatially distributed hydrologic simulation models allows for a greater degree of realism in terms of process representation but requires a development of a simulation-optimization framework where the model becomes an integral part of optimization. Evolutionary algorithms appear to be a particularly useful optimization tool, able to deal with the combinatorial nature of a watershed simulation-optimization problem and allowing the use of the full water quality model. Evolutionary algorithms treat a particular spatial allocation of conservation practices in a watershed as a candidate solution and utilize sets (populations) of candidate solutions iteratively applying stochastic operators of selection, recombination, and mutation to find improvements with respect to the optimization objectives. The optimization objectives in this case are to minimize nonpoint-source pollution in the watershed, simultaneously minimizing the cost of conservation practices. A recent and expanding set of research is attempting to use similar methods and integrates water quality models with broadly defined evolutionary optimization methods(3,4,9,10,13-15,17-19,22,23,25). In this application, we demonstrate a program which follows Rabotyagov et al.'s approach and integrates a modern and commonly used SWAT water quality model(7) with a

Nitrogen Assessment in the Nooksack-Abbotsford-Sumas Transboundary Watershed

Science.gov (United States)

Lin, J.; Compton, J.; Baron, J.; Schwede, D. B.; Bittman, S.; Hooper, D. U.; Kiffney, P.; Embertson, N.; Carey, B.; MacKay, H.; Black, R.; Bahr, G.; Harrison, J.; Davidson, E. A.

2017-12-01

The Nooksack-Abbotsford-Sumas (NAS) Transboundary Watershed, which spans a portion of the western interface of British Columbia, Washington State, as well as the Lummi Nation and the Nooksack Tribal lands, supports agriculture, estuarine fisheries, diverse wildlife, and urban areas. Excess N has contributed to surface and ground water pollution, shellfish closure, and impaired air quality (such as haze or smog) in some areas in the watershed. The goal of this project is to determine the distribution and quantities of N fluxes of the watershed using site-specific and high-resolution data on N that originates from energy use, transportation, fertilization, wastewater treatment plants (WWTP), animal feeding and manure production, crops and more. This project is one of seven international demonstration projects contributing knowledge of regional N budgets and collaborative approaches toward N management as part of the International Nitrogen Management System (INMS). Successful N reduction relies on the partnership of all stakeholders with appropriate institutions to integrate science, outreach and management efforts. This project will bring together stakeholders on both sides of the international border for a first comprehensive, quantitative characterization of all N inventories and fluxes across this international watershed. Using crop-specific fertilizer application rates and wind-shield-survey land use data, we estimated that the annual fertilizer N input to the U.S. portion of the watershed was about 3779 metric tons (MT), which is very close to the USGS estimate of 3955 MT. Based on county level animal census data, we estimated total excretion N from major livestock (cattle) to be 7895 MT on the U.S. side. Using existing model results from other studies, we estimated that the annual N loading on the U.S. side was about 351 MT from point sources, 527 MT from atmospheric deposition, and about 7 MT from alder fixation. The preliminary results demonstrate an

Evaluating the Performance of Wavelet-based Data-driven Models for Multistep-ahead Flood Forecasting in an Urbanized Watershed

Science.gov (United States)

Kasaee Roodsari, B.; Chandler, D. G.

2015-12-01

A real-time flood forecast system is presented to provide emergency management authorities sufficient lead time to execute plans for evacuation and asset protection in urban watersheds. This study investigates the performance of two hybrid models for real-time flood forecasting at different subcatchments of Ley Creek watershed, a heavily urbanized watershed in the vicinity of Syracuse, New York. Hybrid models include Wavelet-Based Artificial Neural Network (WANN) and Wavelet-Based Adaptive Neuro-Fuzzy Inference System (WANFIS). Both models are developed on the basis of real time stream network sensing. The wavelet approach is applied to decompose the collected water depth timeseries to Approximation and Detail components. The Approximation component is then used as an input to ANN and ANFIS models to forecast water level at lead times of 1 to 10 hours. The performance of WANN and WANFIS models are compared to ANN and ANFIS models for different lead times. Initial results demonstrated greater predictive power of hybrid models.

Desertification Assessment Using MEDALUS Model in Watershed Oued El Maleh, Morocco

Directory of Open Access Journals (Sweden)

Hicham Lahlaoi

2017-07-01

Full Text Available Along with being a dynamic process that affects large areas, desertification is also one of the most serious problems in many countries. The effects of this phenomenon threaten the sustainability of natural resources, namely water resources, agricultural production and major basic infrastructure, specifically roads and habitations. Several factors exacerbate this phenomenon such as the climate dryness, the geological and morphological characteristics of the terrain, the irrational use of space, population growth and the over-exploitation of vegetation and water resources. This work aims to evaluate the desertification index in the Oued-El-Maleh watershed, through the integration of key factors involved in the MEDALUS model (Mediterranean Desertification and Land Use within a GIS. The model includes among its indexes: climate, vegetation, soil and management. Each index was obtained by the combination of sub-indexes. All the factors, measured and integrated into a geographic information system, enabled us to spatialize, on a synthetic map, the degree of the desertification effect throughout the watershed. This map is a managing tool available for decision-making regarding the selection of priority areas in the fight against desertification. High sensitivity to desertification class represents only 35% of the watershed. This class is concentrated in the north of the study area that corresponds to plains and low altitude. This could be explained by the dominance of agro-pastoral activity and the presence of a big population pressure.

Estimation of the peak factor based on watershed characteristics

Energy Technology Data Exchange (ETDEWEB)

Gauthier, Jean; Nolin, Simon; Ruest, Benoit [BPR Inc., Quebec, (Canada)

2010-07-01

Hydraulic modeling and dam structure design require the river flood flow as a primary input. For a given flood event, the ratio of peak flow over mean daily flow defines the peak factor. The peak factor value is dependent on the watershed and location along the river. The main goal of this study consisted in finding a relationship between watershed characteristics and this peak factor. Regression analyses were carried out on 53 natural watersheds located in the southern part of the province of Quebec using data from the Centre d'expertise hydrique du Quebec (CEHQ). The watershed characteristics included in the analyses were the watershed area, the maximum flow length, the mean slope, the lake proportion and the mean elevation. The results showed that watershed area and length are the major parameters influencing the peak factor. Nine natural watersheds were also used to test the use of a multivariable model in order to determine the peak factor for ungauged watersheds.

Upstream-downstream cooperation approach in Guanting Reservoir watershed.

Science.gov (United States)

Yang, Zhi-Feng; Zhang, Wen-Guo

2005-01-01

A case study is introduced and discussed concerning water dispute of misuse and pollution between up- and down-stream parts. The relations between water usage and local industrial structures are analyzed. Results show it is important to change industrial structures of the target region along with controlling water pollution by technical and engineering methods. Three manners of upstream-downstream cooperation are presented and discussed based on the actual conditions of Guangting Reservoir watershed. Two typical scenarios are supposed and studied along with the local plan on water resources development. The best solution for this cooperation presents a good way to help the upstream developing in a new pattern of eco-economy.

Modeling of Faecal Contamination in Water from Catchment to Shellfish Growing Area

OpenAIRE

Bougeard, Morgane; Le Saux, Jean-claude; Perenne, Nicolas; Le Guyader, Soizick; Pommepuy, Monique

2009-01-01

During rainstorms, watersheds can introduce large amounts of faecal pollution into the rivers and sea, leading to shellfish contamination. In this study, we assessed Escherichia coli fluxes from a catchment, and their impact on estuarine water quality, using two assembled models. For the catchment, the agro-hydrological model SWAT was implemented integrating land uses, soil, topography, rainfall and other climatic data on Daoulas watershed (France). Initially, the SWAT model was calibrated an...

Modeling the effects of LID practices on streams health at watershed scale

Science.gov (United States)

Shannak, S.; Jaber, F. H.

2013-12-01

Increasing impervious covers due to urbanization will lead to an increase in runoff volumes, and eventually increase flooding. Stream channels adjust by widening and eroding stream bank which would impact downstream property negatively (Chin and Gregory, 2001). Also, urban runoff drains in sediment bank areas in what's known as riparian zones and constricts stream channels (Walsh, 2009). Both physical and chemical factors associated with urbanization such as high peak flows and low water quality further stress aquatic life and contribute to overall biological condition of urban streams (Maxted et al., 1995). While LID practices have been mentioned and studied in literature for stormwater management, they have not been studied in respect to reducing potential impact on stream health. To evaluate the performance and the effectiveness of LID practices at a watershed scale, sustainable detention pond, bioretention, and permeable pavement will be modeled at watershed scale. These measures affect the storm peak flows and base flow patterns over long periods, and there is a need to characterize their effect on stream bank and bed erosion, and aquatic life. These measures will create a linkage between urban watershed development and stream conditions specifically biological health. The first phase of this study is to design and construct LID practices at the Texas A&M AgriLife Research and Extension Center-Dallas, TX to collect field data about the performance of these practices on a smaller scale. The second phase consists of simulating the performance of LID practices on a watershed scale. This simulation presents a long term model (23 years) using SWAT to evaluate the potential impacts of these practices on; potential stream bank and bed erosion, and potential impact on aquatic life in the Blunn Watershed located in Austin, TX. Sub-daily time step model simulations will be developed to simulate the effectiveness of the three LID practices with respect to reducing

An ecosystem report on the Panama Canal: Monitoring the status of the forest communities and the watershed

Science.gov (United States)

Ibanez, R.; Condit, R.; Angehr, G.; Aguilar, S.; Garcia, T.; Martinez, R.; Sanjur, A.; Stallard, R.; Wright, S.J.; Rand, A.S.; Heckadon, S.

2002-01-01

towns are heavily polluted. Analyses of sediment loads in rivers throughout the watershed did not indicate that erosion has been increasing as a result of deforestation, rather, erosion seems to be driven largely by total rainfall and heavy rainfall events that cause landslides. Still, models suggest that large-scale deforestation would increase landslide frequency, and failure to detect increases in erosion could be due to the gradual deforestation rate and the short time period over which data are available. A study of runoff showed deforestation increased the amount of water from rainfall that passed directly into streams. As a result, dry season flow was reduced in a deforested catchment relative to a forested one. Currently, the Panama Canal watershed has extensive forest areas and streams relatively unaffected by humans. But impacts of hunting and pollution near towns are clear, and the burgeoning population will exacerbate these impacts in the next few decades. Changes in policies regarding forest protection and pollution control are necessary.

A coupled modeling framework for sustainable watershed management in transboundary river basins

Directory of Open Access Journals (Sweden)

H. F. Khan

2017-12-01

Full Text Available There is a growing recognition among water resource managers that sustainable watershed management needs to not only account for the diverse ways humans benefit from the environment, but also incorporate the impact of human actions on the natural system. Coupled natural–human system modeling through explicit modeling of both natural and human behavior can help reveal the reciprocal interactions and co-evolution of the natural and human systems. This study develops a spatially scalable, generalized agent-based modeling (ABM framework consisting of a process-based semi-distributed hydrologic model (SWAT and a decentralized water system model to simulate the impacts of water resource management decisions that affect the food–water–energy–environment (FWEE nexus at a watershed scale. Agents within a river basin are geographically delineated based on both political and watershed boundaries and represent key stakeholders of ecosystem services. Agents decide about the priority across three primary water uses: food production, hydropower generation and ecosystem health within their geographical domains. Agents interact with the environment (streamflow through the SWAT model and interact with other agents through a parameter representing willingness to cooperate. The innovative two-way coupling between the water system model and SWAT enables this framework to fully explore the feedback of human decisions on the environmental dynamics and vice versa. To support non-technical stakeholder interactions, a web-based user interface has been developed that allows for role-play and participatory modeling. The generalized ABM framework is also tested in two key transboundary river basins, the Mekong River basin in Southeast Asia and the Niger River basin in West Africa, where water uses for ecosystem health compete with growing human demands on food and energy resources. We present modeling results for crop production, energy generation and violation of

A coupled modeling framework for sustainable watershed management in transboundary river basins

Science.gov (United States)

Furqan Khan, Hassaan; Yang, Y. C. Ethan; Xie, Hua; Ringler, Claudia

2017-12-01

There is a growing recognition among water resource managers that sustainable watershed management needs to not only account for the diverse ways humans benefit from the environment, but also incorporate the impact of human actions on the natural system. Coupled natural-human system modeling through explicit modeling of both natural and human behavior can help reveal the reciprocal interactions and co-evolution of the natural and human systems. This study develops a spatially scalable, generalized agent-based modeling (ABM) framework consisting of a process-based semi-distributed hydrologic model (SWAT) and a decentralized water system model to simulate the impacts of water resource management decisions that affect the food-water-energy-environment (FWEE) nexus at a watershed scale. Agents within a river basin are geographically delineated based on both political and watershed boundaries and represent key stakeholders of ecosystem services. Agents decide about the priority across three primary water uses: food production, hydropower generation and ecosystem health within their geographical domains. Agents interact with the environment (streamflow) through the SWAT model and interact with other agents through a parameter representing willingness to cooperate. The innovative two-way coupling between the water system model and SWAT enables this framework to fully explore the feedback of human decisions on the environmental dynamics and vice versa. To support non-technical stakeholder interactions, a web-based user interface has been developed that allows for role-play and participatory modeling. The generalized ABM framework is also tested in two key transboundary river basins, the Mekong River basin in Southeast Asia and the Niger River basin in West Africa, where water uses for ecosystem health compete with growing human demands on food and energy resources. We present modeling results for crop production, energy generation and violation of eco

Development of a "Hydrologic Equivalent Wetland" Concept for Modeling Cumulative Effects of Wetlands on Watershed Hydrology

Science.gov (United States)

Wang, X.; Liu, T.; Li, R.; Yang, X.; Duan, L.; Luo, Y.

2012-12-01

Wetlands are one of the most important watershed microtopographic features that affect, in combination rather than individually, hydrologic processes (e.g., routing) and the fate and transport of constituents (e.g., sediment and nutrients). Efforts to conserve existing wetlands and/or to restore lost wetlands require that watershed-level effects of wetlands on water quantity and water quality be quantified. Because monitoring approaches are usually cost or logistics prohibitive at watershed scale, distributed watershed models, such as the Soil and Water Assessment Tool (SWAT), can be a best resort if wetlands can be appropriately represented in the models. However, the exact method that should be used to incorporate wetlands into hydrologic models is the subject of much disagreement in the literature. In addition, there is a serious lack of information about how to model wetland conservation-restoration effects using such kind of integrated modeling approach. The objectives of this study were to: 1) develop a "hydrologic equivalent wetland" (HEW) concept; and 2) demonstrate how to use the HEW concept in SWAT to assess effects of wetland restoration within the Broughton's Creek watershed located in southwestern Manitoba of Canada, and of wetland conservation within the upper portion of the Otter Tail River watershed located in northwestern Minnesota of the United States. The HEWs were defined in terms of six calibrated parameters: the fraction of the subbasin area that drains into wetlands (WET_FR), the volume of water stored in the wetlands when filled to their normal water level (WET_NVOL), the volume of water stored in the wetlands when filled to their maximum water level (WET_MXVOL), the longest tributary channel length in the subbasin (CH_L1), Manning's n value for the tributary channels (CH_N1), and Manning's n value for the main channel (CH_N2). The results indicated that the HEW concept allows the nonlinear functional relations between watershed processes

Dynamic modeling of organophosphate pesticide load in surface water in the northern San Joaquin Valley watershed of California

Energy Technology Data Exchange (ETDEWEB)

Luo Yuzhou [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou, 325000 (China); Zhang Xuyang [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Liu Xingmei [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Institute of Soil, Water and Environmental Science, Zhejiang University, Hangzhou 310029 (China); Ficklin, Darren [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Zhang Minghua [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou, 325000 (China)], E-mail: mhzhang@ucdavis.edu

2008-12-15

The hydrology, sediment, and pesticide transport components of the Soil and Water Assessment Tool (SWAT) were evaluated on the northern San Joaquin Valley watershed of California. The Nash-Sutcliffe coefficients for monthly stream flow and sediment load ranged from 0.49 to 0.99 over the watershed during the study period of 1992-2005. The calibrated SWAT model was applied to simulate fate and transport processes of two organophosphate pesticides of diazinon and chlorpyrifos at watershed scale. The model generated satisfactory predictions of dissolved pesticide loads relative to the monitoring data. The model also showed great success in capturing spatial patterns of dissolved diazinon and chlorpyrifos loads according to the soil properties and landscape morphology over the large agricultural watershed. This study indicated that curve number was the major factor influencing the hydrology while pesticide fate and transport were mainly affected by surface runoff and pesticide application and in the study area. - Major factors governing the instream loads of organophosphate pesticides are magnitude and timing of surface runoff and pesticide application.

Dynamic modeling of organophosphate pesticide load in surface water in the northern San Joaquin Valley watershed of California

International Nuclear Information System (INIS)

Luo Yuzhou; Zhang Xuyang; Liu Xingmei; Ficklin, Darren; Zhang Minghua

2008-01-01

The hydrology, sediment, and pesticide transport components of the Soil and Water Assessment Tool (SWAT) were evaluated on the northern San Joaquin Valley watershed of California. The Nash-Sutcliffe coefficients for monthly stream flow and sediment load ranged from 0.49 to 0.99 over the watershed during the study period of 1992-2005. The calibrated SWAT model was applied to simulate fate and transport processes of two organophosphate pesticides of diazinon and chlorpyrifos at watershed scale. The model generated satisfactory predictions of dissolved pesticide loads relative to the monitoring data. The model also showed great success in capturing spatial patterns of dissolved diazinon and chlorpyrifos loads according to the soil properties and landscape morphology over the large agricultural watershed. This study indicated that curve number was the major factor influencing the hydrology while pesticide fate and transport were mainly affected by surface runoff and pesticide application and in the study area. - Major factors governing the instream loads of organophosphate pesticides are magnitude and timing of surface runoff and pesticide application

Hydrological Modeling of Watersheds Using the Only Corresponding Competitor Method: The Case of M'Zab Basin, South East Algeria

OpenAIRE

Oulad Naoui Noureddine; Cherif ELAmine; Djehiche Abdelkader

2017-01-01

Water resources management includes several disciplines; the modeling of rainfall-runoff relationship is the most important discipline to prevent natural risks. There are several models to study rainfall-runoff relationship in watersheds. However, the majority of these models are not applicable in all basins of the world. In this study, a new stochastic method called The Only Corresponding Competitor method (OCC) was used for the hydrological modeling of M’ZAB Watershed (South East of Alge...

Applying soil property information for watershed assessment.

Science.gov (United States)

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.

Improving Watershed-Scale Hydrodynamic Models by Incorporating Synthetic 3D River Bathymetry Network

Science.gov (United States)

Dey, S.; Saksena, S.; Merwade, V.

2017-12-01

Digital Elevation Models (DEMs) have an incomplete representation of river bathymetry, which is critical for simulating river hydrodynamics in flood modeling. Generally, DEMs are augmented with field collected bathymetry data, but such data are available only at individual reaches. Creating a hydrodynamic model covering an entire stream network in the basin requires bathymetry for all streams. This study extends a conceptual bathymetry model, River Channel Morphology Model (RCMM), to estimate the bathymetry for an entire stream network for application in hydrodynamic modeling using a DEM. It is implemented at two large watersheds with different relief and land use characterizations: coastal Guadalupe River basin in Texas with flat terrain and a relatively urban White River basin in Indiana with more relief. After bathymetry incorporation, both watersheds are modeled using HEC-RAS (1D hydraulic model) and Interconnected Pond and Channel Routing (ICPR), a 2-D integrated hydrologic and hydraulic model. A comparison of the streamflow estimated by ICPR at the outlet of the basins indicates that incorporating bathymetry influences streamflow estimates. The inundation maps show that bathymetry has a higher impact on flat terrains of Guadalupe River basin when compared to the White River basin.

Mixed deterministic statistical modelling of regional ozone air pollution

KAUST Repository

Kalenderski, Stoitchko

2011-03-17

We develop a physically motivated statistical model for regional ozone air pollution by separating the ground-level pollutant concentration field into three components, namely: transport, local production and large-scale mean trend mostly dominated by emission rates. The model is novel in the field of environmental spatial statistics in that it is a combined deterministic-statistical model, which gives a new perspective to the modelling of air pollution. The model is presented in a Bayesian hierarchical formalism, and explicitly accounts for advection of pollutants, using the advection equation. We apply the model to a specific case of regional ozone pollution-the Lower Fraser valley of British Columbia, Canada. As a predictive tool, we demonstrate that the model vastly outperforms existing, simpler modelling approaches. Our study highlights the importance of simultaneously considering different aspects of an air pollution problem as well as taking into account the physical bases that govern the processes of interest. © 2011 John Wiley & Sons, Ltd..

Verifying mapping, monitoring and modeling of fine sediment pollution sources in West Maui, Hawai'i, USA

Science.gov (United States)

Cerovski-Darriau, C.; Stock, J. D.

2017-12-01

Coral reef ecosystems, and the fishing and tourism industries they support, depend on clean waters. Fine sediment pollution from nearshore watersheds threatens these enterprises in West Maui, Hawai'i. To effectively mitigate sediment pollution, we first have to know where the sediment is coming from, and how fast it erodes. In West Maui, we know that nearshore sediment plumes originate from erosion of fine sand- to silt-sized air fall deposits where they are exposed by grazing, agriculture, or other disturbances. We identified and located these sediment sources by mapping watershed geomorphological processes using field traverses, historic air photos, and modern orthophotos. We estimated bank lowering rates using erosion pins, and other surface erosion rates were extrapolated from data collected elsewhere on the Hawaiian Islands. These measurements and mapping led to a reconnaissance sediment budget which showed that annual loads are dominated by bank erosion of legacy terraces. Field observations during small storms confirm that nearshore sediment plumes are sourced from bank erosion of in-stream, legacy agricultural deposits. To further verify this sediment budget, we used geochemical fingerprinting to uniquely identify each potential source (e.g. stream banks, agricultural fields, roads, other human modified soils, and hillslopes) from the Wahikuli watershed (10 km2) and analyzed the fine fraction using ICP-MS for elemental geochemistry. We propose to apply this the fingerprinting results to nearshore suspended sediment samples taken during storms to identify the proportion of sediment coming from each source. By combining traditional geomorphic mapping, monitoring and geochemistry, we hope to provide a powerful tool to verify the primary source of sediment reaching the nearshore.

Report on the Watershed Monitoring Program at the Paducah Site January-December 1998

Energy Technology Data Exchange (ETDEWEB)

Kszos, L.A.; Peterson, M.J.; Ryon, M.G.; Southworth, G.R.

1999-03-01

Watershed Monitoring of Big Bayou and Little Bayou creeks has been conducted since 1987. The monitoring was conducted by the University of Kentucky between 1987 and 1991 and by staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) from 1991 to present. The goals of monitoring are to (1) demonstrate that the effluent limitations established for DOE protect and maintain the use of Little Bayour and Big Bayou creeks for frowth and propagation of fish and other aquatic life, (2) characterize potential environmental impacts, and (3) document the effects of pollution abatement facilities on stream biota. The watershed (biological) monitoring discussed in this report was conducted under DOE Order 5400.1, General Environmental Protection Program. Future monitoring will be conducted as required by the Kentucky Pollutant Discharge Elimination System (KPDES) permit issued to the Department of Energy (DOE) in March 1998. A draft Watershed Monitoring Program plan was approved by the Kentucky Division of Water and will be finalized in 1999. The DOE permit also requires toxicity monitoring of one continuous outfall and of three intermittent outfalls on a quarterly basis. The Watershed Monitoring Program for the Paducah Site during calendar year 1998 consisted of three major tasks: (1) effluent toxicity monitoring, (2) bioaccumulation studies, and (3) ecological surveys of fish communities. This report focuses on ESD activities occurring from january 1998 to December 1998, although activities conducted outside this time period are included as appropriate.

Data to support "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations & Biological Condition"

Data.gov (United States)

U.S. Environmental Protection Agency — Spreadsheets are included here to support the manuscript "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition". This...

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

Science.gov (United States)

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

Integrated Approach to Inform the New York City Water Supply System Coupling SAR Remote Sensing Observations and the SWAT Watershed Model

Science.gov (United States)

Tesser, D.; Hoang, L.; McDonald, K. C.

2017-12-01

Efforts to improve municipal water supply systems increasingly rely on an ability to elucidate variables that drive hydrologic dynamics within large watersheds. However, fundamental model variables such as precipitation, soil moisture, evapotranspiration, and soil freeze/thaw state remain difficult to measure empirically across large, heterogeneous watersheds. Satellite remote sensing presents a method to validate these spatially and temporally dynamic variables as well as better inform the watershed models that monitor the water supply for many of the planet's most populous urban centers. PALSAR 2 L-band, Sentinel 1 C-band, and SMAP L-band scenes covering the Cannonsville branch of the New York City (NYC) water supply watershed were obtained for the period of March 2015 - October 2017. The SAR data provides information on soil moisture, free/thaw state, seasonal surface inundation, and variable source areas within the study site. Integrating the remote sensing products with watershed model outputs and ground survey data improves the representation of related processes in the Soil and Water Assessment Tool (SWAT) utilized to monitor the NYC water supply. PALSAR 2 supports accurate mapping of the extent of variable source areas while Sentinel 1 presents a method to model the timing and magnitude of snowmelt runoff events. SMAP Active Radar soil moisture product directly validates SWAT outputs at the subbasin level. This blended approach verifies the distribution of soil wetness classes within the watershed that delineate Hydrologic Response Units (HRUs) in the modified SWAT-Hillslope. The research expands the ability to model the NYC water supply source beyond a subset of the watershed while also providing high resolution information across a larger spatial scale. The global availability of these remote sensing products provides a method to capture fundamental hydrology variables in regions where current modeling efforts and in situ data remain limited.

Modeling pollutant transport using a meshless-lagrangian particle model

International Nuclear Information System (INIS)

Carrington, D.B.; Pepper, D.W.

2002-01-01

A combined meshless-Lagrangian particle transport model is used to predict pollutant transport over irregular terrain. The numerical model for initializing the velocity field is based on a meshless approach utilizing multiquadrics established by Kansa. The Lagrangian particle transport technique uses a random walk procedure to depict the advection and dispersion of pollutants over any type of surface, including street and city canyons

Total pollution effect of urban surface runoff.

Science.gov (United States)

Luo, Hongbing; Luo, Lin; Huang, Gu; Liu, Ping; Li, Jingxian; Hu, Sheng; Wang, Fuxiang; Xu, Rui; Huang, Xiaoxue

2009-01-01

For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD (chemical oxygen demand), TSS (total suspend solid), TP (total phosphorus), TN (total nitrogen) and BOD (biochemical oxygen demand). The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters: rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 (mass first flush ratio) and FF30 (first 30% of runoff volume) can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs (best management practices) facilities.

Watershed Modeling with ArcSWAT and SUFI2 In Cisadane Catchment Area: Calibration and Validation of River Flow Prediction

Directory of Open Access Journals (Sweden)

Iwan Ridwansyah

2014-04-01

Full Text Available Increasing of natural resources utilization as a result of population growth and economic development has caused severe damage on the watershed. The impacts of natural disasters such as floods, landslides and droughts become more frequent. Cisadane Catchment Area is one of 108 priority watershed in Indonesia. SWAT is currently applied world wide and considered as a versatile model that can be used to integrate multiple environmental processes, which support more effective watershed management and the development of better informed policy decision. The objective of this study is to examine the applicability of SWAT model for modeling mountainous catchments, focusing on Cisadane catchment Area in west Java Province, Indonesia. The SWAT model simulation was done for the periods of 2005 – 2010 while it used landuse information in 2009. Methods of Sequential Uncertainty Fitting ver. 2 (SUFI2 and combine with manual calibration were used in this study to calibrate a rainfall-runoff. The Calibration is done on 2007 and the validation on 2009, the R2 and Nash Sutchliffe Efficiency (NSE of the calibration were 0.71 and 0.72 respectively and the validation are 0.708 and 0.7 respectively. The monthly average of surface runoff and total water yield from the simulation were 27.7 mm and 2718.4 mm respectively. This study showed SWAT model can be a potential monitoring tool especially for watersheds in Cisadane Catchment Area or in the tropical regions. The model can be used for another purpose, especially in watershed management.

Geostatistical models for air pollution

International Nuclear Information System (INIS)

Pereira, M.J.; Soares, A.; Almeida, J.; Branquinho, C.

2000-01-01

The objective of this paper is to present geostatistical models applied to the spatial characterisation of air pollution phenomena. A concise presentation of the geostatistical methodologies is illustrated with practical examples. The case study was conducted in an underground copper-mine located on the southern of Portugal, where a biomonitoring program using lichens has been implemented. Given the characteristics of lichens as indicators of air pollution it was possible to gather a great amount of data in space, which enabled the development and application of geostatistical methodologies. The advantages of using geostatistical models compared with deterministic models, as environmental control tools, are highlighted. (author)

Large Scale Computations in Air Pollution Modelling

DEFF Research Database (Denmark)

Zlatev, Z.; Brandt, J.; Builtjes, P. J. H.

Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

Soil and Water Assessment Tool model predictions of annual maximum pesticide concentrations in high vulnerability watersheds.

Science.gov (United States)

Winchell, Michael F; Peranginangin, Natalia; Srinivasan, Raghavan; Chen, Wenlin

2018-05-01

Recent national regulatory assessments of potential pesticide exposure of threatened and endangered species in aquatic habitats have led to increased need for watershed-scale predictions of pesticide concentrations in flowing water bodies. This study was conducted to assess the ability of the uncalibrated Soil and Water Assessment Tool (SWAT) to predict annual maximum pesticide concentrations in the flowing water bodies of highly vulnerable small- to medium-sized watersheds. The SWAT was applied to 27 watersheds, largely within the midwest corn belt of the United States, ranging from 20 to 386 km 2 , and evaluated using consistent input data sets and an uncalibrated parameterization approach. The watersheds were selected from the Atrazine Ecological Exposure Monitoring Program and the Heidelberg Tributary Loading Program, both of which contain high temporal resolution atrazine sampling data from watersheds with exceptionally high vulnerability to atrazine exposure. The model performance was assessed based upon predictions of annual maximum atrazine concentrations in 1-d and 60-d durations, predictions critical in pesticide-threatened and endangered species risk assessments when evaluating potential acute and chronic exposure to aquatic organisms. The simulation results showed that for nearly half of the watersheds simulated, the uncalibrated SWAT model was able to predict annual maximum pesticide concentrations within a narrow range of uncertainty resulting from atrazine application timing patterns. An uncalibrated model's predictive performance is essential for the assessment of pesticide exposure in flowing water bodies, the majority of which have insufficient monitoring data for direct calibration, even in data-rich countries. In situations in which SWAT over- or underpredicted the annual maximum concentrations, the magnitude of the over- or underprediction was commonly less than a factor of 2, indicating that the model and uncalibrated parameterization

Variable Width Riparian Model Enhances Landscape and Watershed Condition

Science.gov (United States)

Abood, S. A.; Spencer, L.

2017-12-01

Riparian areas are ecotones that represent about 1% of USFS administered landscape and contribute to numerous valuable ecosystem functions such as wildlife habitat, stream water quality and flows, bank stability and protection against erosion, and values related to diversity, aesthetics and recreation. Riparian zones capture the transitional area between terrestrial and aquatic ecosystems with specific vegetation and soil characteristics which provide critical values/functions and are very responsive to changes in land management activities and uses. Two staff areas at the US Forest Service have coordinated on a two phase project to support the National Forests in their planning revision efforts and to address rangeland riparian business needs at the Forest Plan and Allotment Management Plan levels. The first part of the project will include a national fine scale (USGS HUC-12 digits watersheds) inventory of riparian areas on National Forest Service lands in western United States with riparian land cover, utilizing GIS capabilities and open source geospatial data. The second part of the project will include the application of riparian land cover change and assessment based on selected indicators to assess and monitor riparian areas on annual/5-year cycle basis.This approach recognizes the dynamic and transitional nature of riparian areas by accounting for hydrologic, geomorphic and vegetation data as inputs into the delineation process. The results suggest that incorporating functional variable width riparian mapping within watershed management planning can improve riparian protection and restoration. The application of Riparian Buffer Delineation Model (RBDM) approach can provide the agency Watershed Condition Framework (WCF) with observed riparian area condition on an annual basis and on multiple scales. The use of this model to map moderate to low gradient systems of sufficient width in conjunction with an understanding of the influence of distinctive landscape

Integrated Landsat Image Analysis and Hydrologic Modeling to Detect Impacts of 25-Year Land-Cover Change on Surface Runoff in a Philippine Watershed