WorldWideScience

Sample records for nonpoint source watershed

  1. Comparative Assessment of Stormwater and Nonpoint Source Pollution Best Management Practices in Suburban Watershed Management

    OpenAIRE

    Qiu, Zeyuan

    2013-01-01

    Nonpoint source pollution control and stormwater management are two objectives in managing mixed land use watersheds like those in New Jersey. Various best management practices (BMPs) have been developed and implemented to achieve both objectives. This study assesses the cost-effectiveness of selected BMPs for agricultural nonpoint source pollution control and stormwater management in the Neshanic River watershed, a typical mixed land use watershed in central New Jersey, USA. The selected BMP...

  2. 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.

  3. Comparative Assessment of Stormwater and Nonpoint Source Pollution Best Management Practices in Suburban Watershed Management

    Directory of Open Access Journals (Sweden)

    Zeyuan Qiu

    2013-03-01

    Full Text Available Nonpoint source pollution control and stormwater management are two objectives in managing mixed land use watersheds like those in New Jersey. Various best management practices (BMPs have been developed and implemented to achieve both objectives. This study assesses the cost-effectiveness of selected BMPs for agricultural nonpoint source pollution control and stormwater management in the Neshanic River watershed, a typical mixed land use watershed in central New Jersey, USA. The selected BMPs for nonpoint source pollution control include cover crops, prescribed grazing, livestock access control, contour farming, nutrient management, and conservation buffers. The selected BMPs for stormwater management are rain gardens, roadside ditch retrofitting, and detention basin retrofitting. Cost-effectiveness is measured by the reduction in pollutant loads in total suspended solids and total phosphorus relative to the total costs of implementing the selected BMPs. The pollution load reductions for these BMPs are based on the total pollutant loads in the watershed simulated by the Soil and Water Assessment Tool and achievable pollutant reduction rates. The total implementation cost includes BMP installation and maintenance costs. The assessment results indicate that the BMPs for the nonpoint source pollution control are generally much more cost-effective in improving water quality than the BMPs for stormwater management.

  4. Nonpoint Source Pollution.

    Science.gov (United States)

    Mccoy, Nicholas; Chao, Bing; Gang, Daniel Dianchen

    2015-10-01

    The article presents a comprehensive review of research advancing in 2014 on nonpoint source pollution (NPS). The topics presented relate to nonpoint source pollution (NPS) within agricultural and urban areas. NPS pollution from agricultural areas is the main focus in this review. Management of NPS in agricultural, urban and rural areas is presented. Modeling of NPS pollution in different watersheds with various modeling tools is reviewed.

  5. Optimization strategy integrity for watershed agricultural non-point source pollution control based on Monte Carlo simulation

    Science.gov (United States)

    Gong, Y.; Yu, Y. J.; Zhang, W. Y.

    2016-08-01

    This study has established a set of methodological systems by simulating loads and analyzing optimization strategy integrity for the optimization of watershed non-point source pollution control. First, the source of watershed agricultural non-point source pollution is divided into four aspects, including agricultural land, natural land, livestock breeding, and rural residential land. Secondly, different pollution control measures at the source, midway and ending stages are chosen. Thirdly, the optimization effect of pollution load control in three stages are simulated, based on the Monte Carlo simulation. The method described above is applied to the Ashi River watershed in Heilongjiang Province of China. Case study results indicate that the combined three types of control measures can be implemented only if the government promotes the optimized plan and gradually improves implementation efficiency. This method for the optimization strategy integrity for watershed non-point source pollution control has significant reference value.

  6. Landscape planning for agricultural non-point source pollution reduction. II. Balancing watershed size, number of watersheds, and implementation effort.

    Science.gov (United States)

    Maxted, Jeffrey T; Diebel, Matthew W; Vander Zanden, M Jake

    2009-01-01

    Agricultural non-point source (NPS) pollution poses a severe threat to water quality and aquatic ecosystems. In response, tremendous efforts have been directed toward reducing these pollution inputs by implementing agricultural conservation practices. Although conservation practices reduce pollution inputs from individual fields, scaling pollution control benefits up to the watershed level (i.e., improvements in stream water quality) has been a difficult challenge. This difficulty highlights the need for NPS reduction programs that focus efforts within target watersheds and at specific locations within target watersheds, with the ultimate goal of improving stream water quality. Fundamental program design features for NPS control programs--i.e., number of watersheds in the program, total watershed area, and level of effort expended within watersheds--have not been considered in any sort of formal analysis. Here, we present an optimization model that explores the programmatic and environmental trade-offs between these design choices. Across a series of annual program budgets ranging from $2 to $200 million, the optimal number of watersheds ranged from 3 to 27; optimal watershed area ranged from 29 to 214 km(2); and optimal expenditure ranged from $21,000 to $35,000/km(2). The optimal program configuration was highly dependent on total program budget. Based on our general findings, we delineated hydrologically complete and spatially independent watersheds ranging in area from 20 to 100 km(2). These watersheds are designed to serve as implementation units for a targeted NPS pollution control program currently being developed in Wisconsin.

  7. Contribution of base flow to nonpoint source pollution loads in an agricultural watershed

    Science.gov (United States)

    Schilling, K.E.; Wolter, C.F.

    2001-01-01

    Nonpoint source pollution of surface water from overland flow, drainage tiles, and ground water discharge is a major cause of water quality impairment in Iowa. Nonpoint source pollution from base flow ground water was estimated in the Walnut Creek watershed by measuring chemical loads of atrazine, nitrate, chloride, and sulfate at 18 tributary creeks and 19 tiles. Loads were measured during a stable base flow period at creeks and files that discharged into Walnut Creek between two stream gauges. Chemical concentrations of atrazine (restored prairie areas. Three methods were used to estimate base flow discharge in the watershed: (1) Darcy flux; (2) watershed discharge budget; and (3) discharge-drainage area; each yielded similar results (31.2 L/s to 62.3 L/s). Base flow loads to the main channel were estimated by subtracting the loads from the upstream gauge; creeks and tiles, from the total load measured at the downstream gauge station. Base flow concentration for atrazine ranged from 0.15 to 0.29 ??g/L and sulfate concentration ranged from 32 to 64 mg/L, whereas concentrations for nitrate and chloride were negative (-1 to -4 mg/L). Calculated base flow concentrations of atrazine and sulfate appeared to be reasonable estimates, but negative concentrations of nitrate and chloride imply either loss of chemical mass in the stream from upstream to downstream sampling points or measurement error. Load data suggest little contribution from base flow pollutants to Walnut Creek water quality, with most of the pollutant load derived from major tributary creeks. Results from this study have implications for determining total maximum daily loads in agricultural watersheds where contributions from point sources (creeks and tiles) can he used to estimate loads from nonpoint source ground water inputs.Nonpoint source pollution of surface water from overland flow, drainage tiles, and ground water discharge is a major cause of water quality impairment in Iowa. Nonpoint source

  8. Spatial and Temporal Distribution Characteristics of Agricultural Non-point Source Pollution in Xixi Watershed of Jinjiang Basin

    Institute of Scientific and Technical Information of China (English)

    Kun RONG; Jiqiang ZHANG; Yang SHI

    2016-01-01

    The SWAT model was applied to analyze the temporal-spatial distribution patterns of non-point source pollution loads and the difference of pollution loads of different land use types in Xixi Watershed of Jinjiang Basin. The results showed that both yearly nitrogen and phosphorus pollution loads were evenly distributed during 1973 to 1979,the annual TN pollution from non-point source was 1530 t,or 6. 3 kg / ha,and the annual TP pollution from non-point source was 270 t,or 1. 1 kg / ha during 1973 to 1979 in the watershed. Considerable differences were identified on both monthly nitrogen and phosphorus pollution loads. The TN and TP pollution loads during the flood season( from April to September) accounted for 76. 2% and 75. 8% of the annual load respectively. There were great differences in both TN and TP pollution loads of different land use types in the study area,and the pollution load of both farmland and orchard was higher than that of the other land use types. TN and TP pollution loads of farmland accounted for 66% and 83% of total watershed. There was a great spatial difference in the nonpoint source pollution load of the study area. The critical source areas of non-point source pollution are mainly located at Guanqiao Town,Longmen Town,Changkeng Town,Shangqing Town and Dapu Town,where the efforts of controlling pollution should be made.

  9. Tracking Nonpoint Source Nitrogen and Carbon in Watersheds of Chesapeake Bay

    Science.gov (United States)

    Kaushal, S.; Pennino, M. J.; Duan, S.; Blomquist, J.

    2012-12-01

    Humans have altered nitrogen and carbon cycles in rivers regionally with important impacts on coastal ecosystems. Nonpoint source nitrogen pollution is a leading contributor to coastal eutrophication and hypoxia. Shifts in sources of carbon impact downstream ecosystem metabolism and fate and transport of contaminants in coastal zones. We used a combination of stable isotopes and optical tracers to investigate fate and transport of nitrogen and carbon sources in tributaries of the largest estuary in the U.S., the Chesapeake Bay. We analyzed isotopic composition of water samples from major tributaries including the Potomac River, Susquehanna River, Patuxent River, and Choptank River during routine and storm event sampling over multiple years. A positive correlation between δ15N-NO3- and δ18O-NO3- in the Potomac River above Washington D.C. suggested denitrification or biological uptake in the watershed was removing agriculturally-derived N during summer months. In contrast, the Patuxent River in Maryland showed elevated δ15N-NO3- (5 - 12 per mil) with no relationship to δ18O-NO3- suggesting the importance of wastewater sources. From the perspective of carbon sources, there were distinct isotopic values of the δ13C-POM of particulate organic matter and fluorescence excitation emission matrices (EEMS) for rivers influenced by their dominant watershed land use. EEMS showed that there were increases in the humic and fulvic fractions of dissolved organic matter during spring floods, particularly in the Potomac River. Stable isotopic values of δ13C-POM also showed rapid depletion suggesting terrestrial carbon "pulses" in the Potomac River each spring. The δ15N-POM peaked to 10 - 15 per mil each spring suggested a potential manure source or result of biological processing within the watershed. Overall, there were considerable changes in sources and transformations of nitrogen and carbon that varied across rivers and that contribute to nitrogen and carbon loads

  10. [Three patterns of interaction between soil and non-point source P-pollutants in agricultural watershed].

    Science.gov (United States)

    Wang, Xia-hui; Yin, Cheng-qing; Yan, Xiao; Shan, Bao-qing; Wang, Wei-dong

    2004-07-01

    Typical agricultural watershed was selected to study the interactions between soil matrix and non-point source P-pollutants in surface runoff under simulative conditions. The soil samples were taken in different spatial locations in this watershed and were under different degree of human disturbance. The results showed that the interactions between different soil matrix and phosphorus could be divided into three patterns:retention, release and combination of retention and release. Soil of retention pattern has strong adsorption capacity of phosphate and will retain phosphorus from polluted runoff. Soil of release pattern has significant desorption capacity of phosphate and will release phosphorus to the runoff. Soil of retention and release combination pattern will retain or release phosphorus according to the phosphate concentration in the polluted runoff. These results showed that soil matrix in different spatial locations in the agricultural watershed have different ecological functions and environmental values under the processing of natural conditions and human disturbance. From the view of occurrence of non-point source pollution, these soils could become the sink of pollutants as well as the source of pollutants. Under some conditions, there has a conversion between sink and source of them. These results are valuable for control of non-point source pollution on watershed level, identification of key source area of pollutants and improvement of efficiency of control measures.

  11. SPATIAL ANALYSIS OF SOIL EROSION AND NON-POINT SOURCE POLLUTION BASED ON GIS IN ERLONG LAKE WATERSHED, JILIN PROVINCE

    Institute of Scientific and Technical Information of China (English)

    WANG Ning; ZHANG Hong-yan; WANG Hui-lian; ZHANG Zheng-xiang

    2004-01-01

    Data collection, factor composition, nappe analysis and integrative simulation of natural geographical factors in Erlong Lake watershed have been carried out based on GIS. The risk areas where non-point source pollution may occur were compartmentalized and assessed, and the total soil erosion and the runoffs of N and P with rainfall in this valley were worked out by experiment and GIS mapping. The study indicated that the main type of soil in dry land with variable slope east of the lake and the middle-south parts of steep slope mountainous region (erosion source pollution (NSP) of nitrogen and phosphorus loss was corresponded with the soil erosion. Spatial distribution and the reasons of the distribution difference have been presented and it was emphasized that the human activities among the influence factors was the most important. It surely offers a scientific basis to control and prevent non-point source pollution in the watershed.

  12. Nonpoint Source: Agriculture

    Science.gov (United States)

    Agricultural runoff as a nonpoint source category of pollution. Resouces to learn more a bout conservation practices to reduce water quality impacts from storm water run off and ground water infiltration

  13. Water and nonpoint source pollution estimation in the watershed with limited data availability based on hydrological simulation and regression model.

    Science.gov (United States)

    Huiliang, Wang; Zening, Wu; Caihong, Hu; Xinzhong, Du

    2015-09-01

    Nonpoint source (NPS) pollution is considered as the main reason for water quality deterioration; thus, to quantify the NPS loads reliably is the key to implement watershed management practices. In this study, water quality and NPS loads from a watershed with limited data availability were studied in a mountainous area in China. Instantaneous water discharge was measured through the velocity-area method, and samples were taken for water quality analysis in both flood and nonflood days in 2010. The streamflow simulated by Hydrological Simulation Program-Fortran (HSPF) from 1995 to 2013 and a regression model were used to estimate total annual loads of various water quality parameters. The concentrations of total phosphorus (TP) and total nitrogen (TN) were much higher during the flood seasons, but the concentrations of ammonia nitrogen (NH3-N) and nitrate nitrogen (NO3-N) were lower during the flood seasons. Nevertheless, only TP concentration was positively correlated with the flow rate. The fluctuation of annual load from this watershed was significant. Statistical results indicated the significant contribution of pollutant fluxes during flood seasons to annual fluxes. The loads of TP, TN, NH3-N, and NO3-N in the flood seasons were accounted for 58-85, 60-82, 63-88, 64-81% of the total annual loads, respectively. This study presented a new method for estimation of the water and NPS loads in the watershed with limited data availability, which simplified data collection to watershed model and overcame the scale problem of field experiment method.

  14. Uncertainty analysis for an effluent trading system in a typical nonpoint-sources-polluted watershed

    Science.gov (United States)

    Chen, Lei; Han, Zhaoxing; Wang, Guobo; Shen, Zhenyao

    2016-07-01

    Conventional effluent trading systems (ETSs) between point sources (PSs) and nonpoint sources (NPSs) are often unreliable because of the uncertain characteristics of NPSs. In this study, a new framework was established for PS-NPS ETSs, and a comprehensive analysis was conducted by quantifying the impacts of the uncertainties associated with the water assimilative capacity (WAC), NPS emissions, and measurement effectiveness. On the basis of these results, the uncertain characteristics of NPSs would result in a less cost-effective PS-NPS ETS during most hydrological periods, and there exists a clear transition occurs from the WAC constraint to the water quality constraint if these stochastic factors are considered. Specifically, the emission uncertainty had a greater impact on PSs, but an increase in the emission or abatement uncertainty caused the abatement efforts to shift from NPSs toward PSs. Moreover, the error transitivity from the WAC to conventional ETS approaches is more obvious than that to the WEFZ-based ETS. When NPSs emissions are relatively high, structural BMPs should be considered for trading, and vice versa. These results are critical to understand the impacts of uncertainty on the functionality of PS-NPS ETSs and to provide a trade-off between the confidence level and abatement efforts.

  15. Uncertainty analysis for an effluent trading system in a typical nonpoint-sources-polluted watershed.

    Science.gov (United States)

    Chen, Lei; Han, Zhaoxing; Wang, Guobo; Shen, Zhenyao

    2016-07-11

    Conventional effluent trading systems (ETSs) between point sources (PSs) and nonpoint sources (NPSs) are often unreliable because of the uncertain characteristics of NPSs. In this study, a new framework was established for PS-NPS ETSs, and a comprehensive analysis was conducted by quantifying the impacts of the uncertainties associated with the water assimilative capacity (WAC), NPS emissions, and measurement effectiveness. On the basis of these results, the uncertain characteristics of NPSs would result in a less cost-effective PS-NPS ETS during most hydrological periods, and there exists a clear transition occurs from the WAC constraint to the water quality constraint if these stochastic factors are considered. Specifically, the emission uncertainty had a greater impact on PSs, but an increase in the emission or abatement uncertainty caused the abatement efforts to shift from NPSs toward PSs. Moreover, the error transitivity from the WAC to conventional ETS approaches is more obvious than that to the WEFZ-based ETS. When NPSs emissions are relatively high, structural BMPs should be considered for trading, and vice versa. These results are critical to understand the impacts of uncertainty on the functionality of PS-NPS ETSs and to provide a trade-off between the confidence level and abatement efforts.

  16. The simulation research of dissolved nitrogen and phosphorus non-point source pollution in Xiao-Jiang watershed of Three Gorges Reservoir area.

    Science.gov (United States)

    Wu, Lei; Long, Tian-Yu; Li, Chong-Ming

    2010-01-01

    Xiao-jiang, with a basin area of almost 5,276 km(2) and a length of 182.4 km, is located in the center of the Three Gorges Reservoir Area, and is the largest tributary of the central section in Three Gorges Reservoir Area, farmland accounts for a large proportion of Xiao-jiang watershed, and the hilly cropland of purple soil is much of the farmland of the watershed. After the second phase of water storage in the Three Gorges Reservoir, the majority of sub-rivers in the reservoir area experienced eutrophication phenomenon frequently, and non-point source (NPS) pollution has become an important source of pollution in Xiao-jiang Watershed. Because dissolved nitrogen and phosphorus non-point source pollution are related to surface runoff and interflow, using climatic, topographic and land cover data from the internet and research institutes, the Semi-Distributed Land-use Runoff Process (SLURP) hydrological model was introduced to simulate the complete hydrological cycle of the Xiao-jiang Watershed. Based on the SLURP distributed hydrological model, non-point source pollution annual output load models of land use and rural residents were respectively established. Therefore, using GIS technology, considering the losses of dissolved nitrogen and phosphorus in the course of transport, a dissolved non-point source pollution load dynamic model was established by the organic coupling of the SLURP hydrological model and land-use output model. Through the above dynamic model, the annual dissolved non-point source nitrogen and phosphorus pollution output as well as the load in different types were simulated and quantitatively estimated from 2001 to 2008, furthermore, the loads of Xiao-jiang Watershed were calculated and expressed by temporal and spatial distribution in the Three Gorges Reservoir Area. The simulation results show that: the temporal changes of dissolved nitrogen and phosphorus load in the watershed are close to the inter-annual changes of rainfall runoff, and the

  17. [Nonpoint source pollution model, AnnAGNPS, assessment for a mixed forested watershed in Three Gorges Reservoir area].

    Science.gov (United States)

    Huang, Zhi-lin; Tian, Yao-wu; Xiao, Wen-fa; Zeng, Li-xiong; Ma, De-ju

    2009-10-15

    Watershed models provide a cost-effective and efficient means of estimating the pollutant loadings entering surface waters, especially when combined with traditional water quality sampling and analyses. But there have often been questions about the accuracy or certainty of models and their predictions. The main goal of this study was to evaluate the performance of AnnAGNPS (Annualized AGricultural NonPoint Source)Pollution Model, in simulating runoff, sediment loading and nutrient loadings under Three Gorges Reservoir area. Most of model input parameters were sourced from Zigui Forest Ecology Station in Three Gorges Reservoir area, State Forestry Administration. Data year 2003 was used for calibration while data year 2004 was used for validation of the model. The whole evaluation consisted of determining the coefficient of determination (R2), Nash-Sutcliffe coefficient of efficiency (E), and the percentage volume error (VE). Results showed that the model predicted the daily runoff volume within the range of acceptable accuracy. The runoff on a daily basis was underpredicted by 5.0% with R2 of 0.93 (p mixed types of land uses and steep slopes.

  18. Watershed Management Tool for Selection and Spacial Allocation of Non-Point Source Pollution Control Practices

    Science.gov (United States)

    Distributed-parameter watershed models are often utilized for evaluating the effectiveness of sediment and nutrient abatement strategies through the traditional {calibrate→ validate→ predict} approach. The applicability of the method is limited due to modeling approximations. In ...

  19. Nationwide assessment of nonpoint source threats to water quality

    Science.gov (United States)

    Thomas C. Brown; Pamela Froemke

    2012-01-01

    Water quality is a continuing national concern, in part because the containment of pollution from nonpoint (diffuse) sources remains a challenge. We examine the spatial distribution of nonpoint-source threats to water quality. On the basis of comprehensive data sets for a series of watershed stressors, the relative risk of water-quality impairment was estimated for the...

  20. [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.

  1. 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

  2. Spatio-temporal variation of erosion-type non-point source pollution in a small watershed of hilly and gully region, Chinese Loess Plateau.

    Science.gov (United States)

    Wu, Lei; Liu, Xia; Ma, Xiao-Yi

    2016-06-01

    Loss of nitrogen and phosphorus in the hilly and gully region of Chinese Loess Plateau not only decreases the utilization rate of fertilizer but also is a potential threat to aquatic environments. In order to explore the process of erosion-type non-point source (NPS) pollution in Majiagou watershed of Loess Plateau, a distributed, dynamic, and integrated NPS pollution model was established to investigate impacts of returning farmland on erosion-type NPS pollution load from 1995 to 2012. Results indicate that (1) the integrated model proposed in this study was verified to be reasonable; the general methodology is universal and can be applicable to the hilly and gully region, Loess Plateau; (2) the erosion-type NPS total nitrogen (TN) and total phosphorus (TP) load showed an overall decreasing trend; the average nitrogen and phosphorus load modulus in the last four years (2009-2012) were 1.23 and 1.63 t/km(2) · a, respectively, which were both decreased by about 35.4 % compared with the initial treatment period (1995-1998); and (3) The spatial variations of NPS pollution are closely related to spatial characteristics of rainfall, topography, and soil and land use types; the peak regions of TN and TP loss mainly occurred along the main river banks of the Yanhe River watershed from northeast to southeast, and gradually decreased with the increase of distance to the left and right river banks, respectively. Results may provide scientific basis for the watershed-scale NPS pollution control of the Loess Plateau.

  3. [Review of urban nonpoint source pollution models].

    Science.gov (United States)

    Wang, Long; Huang, Yue-Fei; Wang, Guang-Qian

    2010-10-01

    The development history of urban nonpoint source pollution models is reviewed. Features, applicability and limitations of seven popular urban nonpoint source pollution models (SWMM, STORM, SLAMM, HSPF, DR3M-QUAL, MOUSE, and HydroWorks) are discussed. The methodology and research findings of uncertainty in urban nonpoint source pollution modeling are presented. Analytical probabilistic models for estimation of urban nonpoint sources are also presented. The research achievements of urban nonpoint source pollution models in China are summarized. The shortcomings and gaps of approaches on urban nonpoint source pollution models are pointed out. Improvements in modeling of pollutants buildup and washoff, sediments and pollutants transport, and pollutants biochemical reactions are desired for those seven popular models. Most of the models developed by researchers in China are empirical models, so that they can only applied for specific small areas and have inadequate accuracy. Future approaches include improving capability in fate and transport simulation of sediments and pollutants, exploring methodologies of modeling urban nonpoint source pollution in regions with little data or incomplete information, developing stochastic models for urban nonpoint source pollution simulation, and applying GIS to facilitate urban nonpoint source pollution simulation.

  4. Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps associated with uranium exploration and mining, Browns Hole, Utah

    Science.gov (United States)

    Marston, Thomas M.; Beisner, Kimberly R.; Naftz, David L.; Snyder, Terry

    2012-01-01

    During August of 2008, 35 solid-phase samples were collected from abandoned uranium waste dumps, undisturbed geologic background sites, and adjacent streambeds in Browns Hole in southeastern Utah. The objectives of this sampling program were (1) to assess impacts on human health due to exposure to radium, uranium, and thorium during recreational activities on and around uranium waste dumps on Bureau of Land Management lands; (2) to compare concentrations of trace elements associated with mine waste dumps to natural background concentrations; (3) to assess the nonpoint source chemical loading potential to ephemeral and perennial watersheds from uranium waste dumps; and (4) to assess contamination from waste dumps to the local perennial stream water in Muleshoe Creek. Uranium waste dump samples were collected using solid-phase sampling protocols. Solid samples were digested and analyzed for major and trace elements. Analytical values for radium and uranium in digested samples were compared to multiple soil screening levels developed from annual dosage calculations in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act's minimum cleanup guidelines for uranium waste sites. Three occupancy durations for sites were considered: 4.6 days per year, 7.0 days per year, and 14.0 days per year. None of the sites exceeded the radium soil screening level of 96 picocuries per gram, corresponding to a 4.6 days per year exposure. Two sites exceeded the radium soil screening level of 66 picocuries per gram, corresponding to a 7.0 days per year exposure. Seven sites exceeded the radium soil screening level of 33 picocuries per gram, corresponding to a 14.0 days per year exposure. A perennial stream that flows next to the toe of a uranium waste dump was sampled, analyzed for major and trace elements, and compared with existing aquatic-life and drinking-water-quality standards. None of the water-quality standards were exceeded in the stream samples.

  5. Assessment and Strategies for Watershed Agricultural Non-point Source Pollution Control%集水区农业非点源污染之评估及控制对策

    Institute of Scientific and Technical Information of China (English)

    林昭远; 陈键鑫; 颜正平

    2001-01-01

    Improper agricultural activities accelerate soil loss and water pollution. An assessment system for agricultural non-point source pollution estimation was developed in this study. Digital Elevation Model (DEM), Remote Sensing (RS) and Geographic Information Systems (GIS) couples with non-point source pollution models were applied in the system to discuss the efficiency of non-point pollution control in a watershed. Concepts of sediment delivery ratio (SDR) and placement of riparian buffer strips couples with the analysis of topography and hydrology for the watersheds of interest to classify the sensitive zone could effectively monitor and control watershed agricultural non-point-source pollution.%集水区内不当之农业活动,加速集水区土壤流失及水库水质恶化。本研究利用数值地形模型(Digital Elevation Model, DEM)、配合遥感探测 (Remote Sensing, RS)与地理信息系统(Geographic Information Systems, GIS)等技术,撰写程序建立集水区农业非点源污染评估系统,探讨集水区农业非点源污染控制之成效。利用泥砂递移率与植生缓冲带区位检视集水区内之农业非点源污染源,划定集水区环境敏感区位,针对敏感区回收造林,可有效控制集水区农业非点源污染。

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Zonation for nonpoint source pollution control in Hongfenghu reservoir watershed%红枫湖流域非点源污染控制区划

    Institute of Scientific and Technical Information of China (English)

    耿润哲; 殷培红; 原庆丹

    2016-01-01

    Eutrophication caused by the enrichment of nitrogen and phosphorus is degrading surface water quality throughout the world. Sources of nutrients include over-fertilized agriculture lands, urban areas with excessive usage of herbicides and insecticides, and eroded soils. Due to the variation of nutrient export over the area and time, it is difficult to identify, assess and control nonpoint source (NPS) pollution. The prevention and mitigation of NPS pollution have become priority tasks in water monitoring and restoration programs in many countries. The interaction of human activities with the inherent variations in soil type, climate, topography and hydrology gives rise to large spatial and temporal variation in nutrient concentrations in surface runoff. Many research efforts are made to explore the processes and spatial characteristics of NPS pollution for prevention and mitigation measures. Major pollutants, particularly from agricultural activities, which include nitrogen, phosphorus nutrients and sediment that have been released into aquatic environments, have caused problems in the Hongfenghu Reservoir watershed, Guiyang. It is necessary to identify the spatial and temporal distributions of NPS pollutants and the highly polluted areas for the purpose of watershed management.In this paper, GIS technology, ArcSWAT model, ANOVA (Analysis of Variance) and CA (Cluster analysis) were used to identify the zonation of NPS sources and control in Yangchanghe river watershed which is one of the main tributaries in northwest of Hongfenghu Reservoir watershed, with relative strong intensive agricultural activities. The results showed that the spatial distribution of NPS pollution load in Yangchanghe river watershed was of great heterogeneity, the agricultural land at higher elevation had the highest NPS pollution loads, and the Liu Guang, Huang La, Jiu Zhou and Bai Yun towns were identified as the critical towns for NPS pollution control. In addition, the most important

  8. Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps associated with uranium exploration and mining, San Rafael Swell, Utah

    Science.gov (United States)

    Freeman, Michael L.; Naftz, David L.; Snyder, Terry; Johnson, Greg

    2008-01-01

    During July and August of 2006, 117 solid-phase samples were collected from abandoned uranium waste dumps, geologic background sites, and adjacent streambeds in the San Rafael Swell, in southeastern Utah. The objective of this sampling program was to assess the nonpoint source chemical loading potential to ephemeral and perennial watersheds from uranium waste dumps on Bureau of Land Management property. Uranium waste dump samples were collected using solid-phase sampling protocols. After collection, solid-phase samples were homogenized and extracted in the laboratory using a field leaching procedure. Filtered (0.45 micron) water samples were obtained from the field leaching procedure and were analyzed for Ag, As, Ba, Be, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, U, V, and Zn at the Inductively Coupled Plasma-Mass Spectrometry Metals Analysis Laboratory at the University of Utah, Salt Lake City, Utah and for Hg at the U.S. Geological Survey National Water Quality Laboratory, Denver, Colorado. For the initial ranking of chemical loading potential of suspect uranium waste dumps, leachate analyses were compared with existing aquatic life and drinking-water-quality standards and the ratio of samples that exceeded standards to the total number of samples was determined for each element having a water-quality standard for aquatic life and drinking-water. Approximately 56 percent (48/85) of the leachate samples extracted from uranium waste dumps had one or more chemical constituents that exceeded aquatic life and drinking-water-quality standards. Most of the uranium waste dump sites with elevated trace-element concentrations in leachates were along Reds Canyon Road between Tomsich Butte and Family Butte. Twelve of the uranium waste dump sites with elevated trace-element concentrations in leachates contained three or more constituents that exceeded drinking-water-quality standards. Eighteen of the uranium waste dump sites had three or more constituents that exceeded trace

  9. ECONOMIC APPROACH FOR CONTROL AGRICULTURAL NONPOINT SOURCE POLLUTION IN CHINA

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-yan; CAO Li-ping

    2005-01-01

    This paper mainly discusses the feasibility to establish economic policy systems for control and management of agricultural nonpoint source pollution in China. The current situation of serious agricultural nonpoint source pollution in China is described firstly. Based on the environmental policy and economics theories, the system of economic policies for control and management of agricultural nonpoint source pollution is designed in this paper. This system includes the policy objective, the designing principle and the methods. The key issues include pollution charge,inputs tax for restriction, subsides for induction and incentive, effluent trading for least cost reduction. The emphases are optimized on inputs tax and agricultural chemical tax permit under complete information, as well as sub-optimized inputs tax under incomplete information, subsides for farm due to positive and negative externality. The functions and suitability of the policies are also analyzed in the paper. According to the field experiment results and other relating economic data in watershed of the Chaohe River, Beijing, some economic approaches to reducing agricultural nonpoint source pollution are proposed. The main idea is to encourage and support the farmers to improve their farming way,and to implement the policy of castigating charge simultaneously. The feasibility of the policies are analyzed with consideration of economy, technology and institution. It is concluded that the economic policies are necessary and feasible.

  10. Controlling Non-Point Source Pollution in Australian Agricultural Systems

    Institute of Scientific and Technical Information of China (English)

    C. GOURLEY; A. RIDLEY

    2005-01-01

    The Australian farming sector is continuing to intensify, particularly within 300 km of the east and southern coastlines.In the future there will be fewer and larger farms, which will use more fertilizer, support more stock, grow more monoculture crops, and utilise more marginal soils. This is likely to increase the major environmental impacts of soil degradation, salt,nutrient and sediment contamination of waterways, and greenhouse gas emissions. Australian national water policy continues to focus on land, stream and groundwater salinity issues, although there is now a greater recognition of the importance of nitrogen and phosphorus losses from agriculture. The general philosophy of policy for dealing with nonpoint source pollution has been towards a voluntary rather than regulatory approach, with state and national governments supporting a range of programs to encourage sustainable agricultural practices. A catchment (watershed) based approach,through the use of integrated catchment management plans, is the primary way that non-point source pollution is addressed at the farm and local level. At an industry level, cotton, grains, meat, sugarcane and dairy amongst others, as well as the Australian fertilizer industry, have responded to non-point source issues by investing in research and development, and developing codes of practice aimed at abating these environmental impacts. Understanding the economic, social, political and cultural contexts of farming as well as the environmental impacts of agriculture are very important in determining the appropriateness of policy responses for Australian farming systems.

  11. SWAT模型在洱海流域面源污染评价中的应用%Application of SWAT Model in Agricultural Non-Point Source Pollution Investigation in Lake Erhai Watershed

    Institute of Scientific and Technical Information of China (English)

    翟玥; 尚晓; 沈剑; 王欣泽

    2012-01-01

    重点污染区域和污染因子的识别是面源污染控制的基础.通过将物理过程模拟及排污系数法计算进行整合,建立了SWAT模型,以描述农业生产活动与污染入湖量之间的关联关系,并以云南洱海流域总氮污染为例,使用验证后的SWAT模型模拟计算不同空间单元和不同农业生产活动对入湖TN的污染贡献系数,定量分析流域内各区域的农业面源污染源结构,识别洱海流域重点农业污染源和农业污染村镇.结果表明,奶牛养殖、生猪养殖和大蒜种植是目前洱海流域内入湖TN污染的最重要农业污染源,占流域总污染负荷的66.12%.对入湖TN污染贡献最大的6个村镇为江尾、右所、三营、玉湖、凤仪和喜洲,占流域总污染负荷的63.41%.%The identification of key polluted areas and factors is the basis of non-point source pollution control. Based on physical processes simulation and the discharge coefficient method, the SWAT model was established to describe the relationship between agricultural production activities and pollution load into a lake. Lake Erhai watershed in Yunnan province was selected as the research area, and TN variation in the lake was calculated. The contribution coefficients of TN nonpoint source pollution to the lake by different spatial areas and different agricultural production activities were calculated with the verified SWAT model, and the pollution source composition in each spatial unit was calculated quantitatively. The key pollution sources and Bpatial units ( administrative village in this study) were identified. The results showed that dairy cattle breeding, pig farming and garlic planting were the major agricultural pollution sources, contributing 66.12% of TN load to the lake. Six villages - Jiangwei, Yousuo, Sanying, Yuhu, Fengyi and Xizhou - contributed most to TN pollution in the lake, accounting for 63.41% of the watershed total pollution load.

  12. Spatial and temporal variability of heavy metals in streams of the Flint Creek and Flint River Watersheds from non-point sources

    OpenAIRE

    I. Abdi; T. Tsegaye; Silitonga, M.; Tadesse, W

    2009-01-01

    Throughout the United States, non-point pollution is responsible for large quantities of heavy metals entering bodies of water. Pollution as a result of heavy metals can impact drinking water supplies, recreation, fisheries, and aquatic species. Presence of heavy metals such as lead (Pb), cadmium (Cd), and chromium (Cr), in surface water may pose great risks to human health as well as to aquatic animals. In order to understand water quality changes due to heavy metal element...

  13. Hydrogeology and Water Quality of the Pepacton Reservoir Watershed in Southeastern New York. Part 3. Responses of Stream Base-Flow Chemistry to Hydrogeologic Factors and Nonpoint-Sources of Contamination

    Science.gov (United States)

    Heisig, Paul M.; Phillips, Patrick J.

    2004-01-01

    Base-flow samples were collected seasonally from 20 small streams in the 372-square-mile Pepacton Reservoir watershed to evaluate the effects of hydrogeologic factors and nonpoint sources of contamination on the chemical composition of ground-water discharge. The reservoir provides part of New York City?s water supply. The subbasins represented one of three general types of land use, each with at least 45 percent forested area (mostly on the hillsides): farmed (dairy) land, formerly farmed land with low-density residential development, or forested land with little or no development. The subbasin areas ranged from 0.38 to 10.23 square miles. All streams were sampled in December 2000 and in May, July, and October 2001. Three of the sites were designated as landuse- index sites and were sampled as many as five additional times during the study. No samples exceeded state or federal drinking-water standards for chloride, sodium, nitrate, orthophosphate, herbicides, or herbicide degradates. The chemical composition of base-flow samples was classified into major-ion water types, which were broadly defined as naturally occurring and road-salt-affected water types. About one-third of the base-flow samples were roadsalt- affected types. Natural water types were differentiated as dilute or evolved. Dilute waters have bicarbonate and sulfate as dominant anions and evolved waters have only bicarbonate as a dominant anion. Dilute water types indicate relatively short ground-water residence times or contact with unreactive aquifer material. Evolved waters have either longer ground-water residence time or contact with more reactive aquifer material than dilute ground waters. The larger subbasins with wider valley-bottom areas were more likely to have evolved water types than small subbasins with little floodplain development. Positive correlations between selected constituents and the intensity of nonpoint sources emphasize the connection between land use, shallow ground

  14. 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

  15. AnnAGNPS – A United States Department of Agriculture Watershed Conservation Management Planning Tool for Non-Point Source Pollution Control

    Science.gov (United States)

    A watershed scale assessment of the effect of conservation practices on the environment is critical when recommending best management practices to agricultural producers. The environmental benefits of these practices have not been widely quantified at the watershed scale, which would require extens...

  16. Nonpoint source pollution loading from an undistributed tropic forest area.

    Science.gov (United States)

    Chang, Chih-Hua; Wen, Ching-Gung; Huang, Chia-Hui; Chang, Shui-Ping; Lee, Chih-Sheng

    2008-11-01

    Water quality and unit nonpoint sources (NPS) pollution load from a forest area were studied in a mountainous watershed in Taiwan. The flow rates were measured with rectangular weirs and samples taken for water quality analysis in both non-rainy and rainy days for 2 years. The subroutine of the Hydrological Simulation Program--FORTRAN was used to simulate runoff for additional 3 years. Total annual loads of various water quality parameters were then estimated by a regression model. Most of the parameter concentrations are higher during the rainy days; their values are typically higher as compared to data from other undisturbed forest areas. Nevertheless, the concentration ratio of dissolved inorganic nitrogen to TN or PO4(3-) -P to TP shows TN or TP no correlations with the flow rates, whereas the concentrations of SS and TP are positively correlated with the flow rate. The fluctuation of annual load from this watershed is significant. For example, six major events of the entire year, for which the total duration is merely 6.4 days, contribute 42% of the annual precipitation and at least 40% of the annual NPS loads. The management for controlling the NPS pollution from this forest watershed is discussed.

  17. Spatial and temporal variability of heavy metals in streams of the Flint Creek and Flint River Watersheds from non-point sources

    OpenAIRE

    Tadesse, W; Silitonga, M.; I. Abdi; T. Tsegaye

    2009-01-01

    Throughout the United States, non-point pollution is responsible for large quantities of heavy metals entering bodies of water. Pollution as a result of heavy metals can impact drinking water supplies, recreation, fisheries, and aquatic species. Presence of heavy metals such as lead (Pb), cadmium (Cd), and chromium (Cr), in surface water may pose great risks to human health as well as to aquatic animals. In order to understand water quality changes due to heavy metal elements and pH as a resu...

  18. Can We Manage Nonpoint-Source Pollution Using Nutrient Concentrations during Seasonal Baseflow?

    Directory of Open Access Journals (Sweden)

    James A. McCarty

    2016-05-01

    Full Text Available Nationwide, a substantial amount of resources has been targeted toward improving water quality, particularly focused on nonpoint-source pollution. This study was conducted to evaluate the relationship between nutrient concentrations observed during baseflow and runoff conditions from 56 sites across five watersheds in Arkansas. Baseflow and stormflow concentrations for each site were summarized using geometric mean and then evaluated for directional association. A significant, positive correlation was found for NO–N, total N, soluble reactive P, and total P, indicating that sites with high baseflow concentrations also had elevated runoff concentrations. Those landscape factors that influence nutrient concentrations in streams also likely result in increased runoff, suggesting that high baseflow concentrations may reflect elevated loads from the watershed. The results highlight that it may be possible to collect water-quality data during baseflow to help define where to target nonpoint-source pollution best management practices within a watershed.

  19. Introducing nonpoint source transferable quotas in nitrogen trading: The effects of transaction costs and uncertainty.

    Science.gov (United States)

    Zhou, Xiuru; Ye, Weili; Zhang, Bing

    2016-03-01

    Transaction costs and uncertainty are considered to be significant obstacles in the emissions trading market, especially for including nonpoint source in water quality trading. This study develops a nonlinear programming model to simulate how uncertainty and transaction costs affect the performance of point/nonpoint source (PS/NPS) water quality trading in the Lake Tai watershed, China. The results demonstrate that PS/NPS water quality trading is a highly cost-effective instrument for emissions abatement in the Lake Tai watershed, which can save 89.33% on pollution abatement costs compared to trading only between nonpoint sources. However, uncertainty can significantly reduce the cost-effectiveness by reducing trading volume. In addition, transaction costs from bargaining and decision making raise total pollution abatement costs directly and cause the offset system to deviate from the optimal state. While proper investment in monitoring and measuring of nonpoint emissions can decrease uncertainty and save on the total abatement costs. Finally, we show that the dispersed ownership of China's farmland will bring high uncertainty and transaction costs into the PS/NPS offset system, even if the pollution abatement cost is lower than for point sources.

  20. Estimation of Non-point Source Pollution Loads Under Uncertain Information

    Institute of Scientific and Technical Information of China (English)

    LI Ruzhong

    2008-01-01

    Many kinds of uncertainties are involved, such as random, fuzzy, grey, unascertained property and so on, in soil erosion process. To exactly predict the non-point source pollution loads, some uncertainties should be taken into consideration. Aiming at the deficiency of present blind number theory being helpless for fuzziness, a novel blind number, i.e. extended-blind number, was introduced by substituting a set of triangular fuzzy numbers (TFNs), ex-pressed as α-cuts, for interval values in present blind number, and the expected value of extended-blind number was also brought forward by referring to the current blind number theory. On the basis of denoting the parameters of Uni-versal Soil Loss Equation (USLE) as extended-blind parameters, a novel USLE model was established for quantita-tively evaluating soil erosion loss and non-point source pollution loads. As a case, the uncertain USLE was employed for predicting the soil erosion loss and non-point source pollution loads of absorbed nitrogen and phosphorus in a dis-trict in the Hangbu-Fengle River basin, in the upstream of Chaohu Lake watershed. The results show that it is feasible in theory to extend blind number into fuzzy environment and reliable on conclusion to apply extended-blind number theory for predicting non-point source pollution loads.

  1. Landscape planning for agricultural nonpoint source pollution reduction I: a geographical allocation framework.

    Science.gov (United States)

    Diebel, Matthew W; Maxted, Jeffrey T; Nowak, Peter J; Vander Zanden, M Jake

    2008-11-01

    Agricultural nonpoint source pollution remains a persistent environmental problem, despite the large amount of money that has been spent on its abatement. At local scales, agricultural best management practices (BMPs) have been shown to be effective at reducing nutrient and sediment inputs to surface waters. However, these effects have rarely been found to act in concert to produce measurable, broad-scale improvements in water quality. We investigated potential causes for this failure through an effort to develop recommendations for the use of riparian buffers in addressing nonpoint source pollution in Wisconsin. We used frequency distributions of phosphorus pollution at two spatial scales (watershed and field), along with typical stream phosphorus (P) concentration variability, to simulate benefit/cost curves for four approaches to geographically allocating conservation effort. The approaches differ in two ways: (1) whether effort is aggregated within certain watersheds or distributed without regard to watershed boundaries (dispersed), and (2) whether effort is targeted toward the most highly P-polluting fields or is distributed randomly with regard to field-scale P pollution levels. In realistic implementation scenarios, the aggregated and targeted approach most efficiently improves water quality. For example, with effort on only 10% of a model landscape, 26% of the total P load is retained and 25% of watersheds significantly improve. Our results indicate that agricultural conservation can be more efficient if it accounts for the uneven spatial distribution of potential pollution sources and the cumulative aspects of environmental benefits.

  2. Reducing future non-point source sediment and phosphorus loading under intensifying agricultural production in the Ethiopian highlands

    Science.gov (United States)

    Mogus, Mamaru; Schmitter, Petra; Tilahun, Seifu; Steenhuise, Tammo

    2016-04-01

    Intensification of agriculture will bring along non-point source pollution in the Ethiopian highlands resulting in eutrophication of lakes. The first signs of eutrophication have been observed already in Lake Tana. The lake it supports the lives of millions in the surrounding through fishing, tourism, transportation and hydropower.Presently, information on non-point source pollution is lacking in the Ethiopian highlands. There are few studies carried out in the highlands on the extent and the source areas of pollution, and models are not available for predicting sediment and phosphorus loading other than those developed for temperate climates. The objective of this chapter is to review existing non-point source studies, report on our findings of sediment and phosphorus sources that are related the non-point source pollution of Lake Tana and to present a non-point source model for the Ethiopian highland based on the Parameter Efficient Semi-distributed Watershed Hydrology Model (PED-WHM).In our research we have found that the saturation excess runoff from valley bottoms and from degraded lands are prevalent in the Ethiopia highlands. The periodically runoff source areas are also the sources for the non-point source pollution and by concentrating best management practices in these source areas we expect that we can reduce pollution without affecting the profitability of the existing farms. The water balance component of the non-point source model has been performing well in predicting both the discharge and the location of the runoff source areas. Sediment and phosphorus prediction models have been developed and are currently being tested for the 7km2Awramba watershed and the 1350 km2Gumara basin. Initial results indicate that 11.2 ton/ha/year sediment load and an accumulation rate of 17.3 mg/kg/year of dissolved phosphorus from Gumara watershed joining the lake. By developing best management practices at this time before non-point source pollution is rampant and

  3. Agriculture Non-Point Source Pollution Control

    OpenAIRE

    2003-01-01

    The Chesapeake Bay is the largest and historically most productive estuary in the United States. It is approximately 200 miles long and 35 mile wide at it broadest point. The Bay's watershed includes parts of six states (Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia, and the entire District of Columbia. This area encompasses 64,000 square-miles, 150 major rivers and s...

  4. Application of Potential Non-Point Pollution Index For An Urban Watershed: Istanbul, Kucukcekmece Lagoon

    Science.gov (United States)

    Musaoglu, N.; Dikerler, T.; Seker, D. Z.; Ustun, B.

    2011-12-01

    Istanbul is a major city with more than 15 million population and limited water resources. Besides, its urbanized area has been rapidly expanding for more than 30 years. Küçükçekmece Lagoon, as a potential RAMSAR site with its rich natural diversity and housing asset for birds, has been suffering from urbanization and industrial stress. With Sazlidere Dam constructed on the Lagoon's most important creek which supplies fresh water, Küçükçekmece Basin has almost 600 km2 wide area. Due to dam operation which cuts fresh water input down, water quality of the Küçükçekmece Lagoon has been deteriorating, as well as other antropogenic impacts. Potential non-point pollution index (or PNPI) is based on land use, soil and topographic data and aims to highlight the potentially polluting areas in a watershed. Denoting those areas, PNPI puts an assessment of the pressure exerted on the water bodies by different land uses. This index calculates different layers in order to represent run-off, land cover effect, and the distance of each polluting source (or pixels) in the study area. By the multiplication of those layers under GIS, a new data layer is produced showing the polluting potential of each pixel on the study area. For by Küçükçekmece Basin, Landsat ETM satellite images have been taken and its land use produced by unsupervised classification. Using this updated data, land use - land cover indicator has been calculated for the basin. Topography is another fact that is needed to produce both run-off indicator and distance indicator and it is generated by elevation data with 5m resolution. By integrating these indicator layers, PNPI analysis layer has been produced for Küçükçekmece Lagoon watershed.

  5. [L-THIA-based management design for controlling urban non-point source pollution].

    Science.gov (United States)

    Guo, Qing-Hai; Yang, Liu; Ke-Ming, Ma

    2007-11-01

    L-THIA Model was used to simulate the amounts of NPS pollutants in 2 catchments of Sanjiao watershed (Sj1, Sj2) in Hanyang district, and the total simulated amount of NPS loads in Sj1 and Sj2 were 1.82 x 10(4) kg, 1.38 x 10(5) kg, respectively. Based on the theory of resource-sink" and interaction of pattern with process, a series of BMPs, including green roof, grassland, porous pavement, infiltration trench, vegetative filter strip and wet pond, were optimized, and effects of BMPs were simulated along the surface runoff pathway. The results show that total pollutants outputs entering Sj1 and Sj2 account for 14.65% and 6.57%, respectively. Combining L-THIA model and BMPs in series is a proper measure for non-point source pollution control and urban development planning at watershed or region scale.

  6. 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.

  7. 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, D.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.

  8. Landscape planning for agricultural nonpoint source pollution reduction III: assessing phosphorus and sediment reduction potential.

    Science.gov (United States)

    Diebel, Matthew W; Maxted, Jeffrey T; Robertson, Dale M; Han, Seungbong; Vander Zanden, M Jake

    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 km(2)) 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.

  9. The Roles of Countrywomen in Controlling Non-point Source Pollution

    Institute of Scientific and Technical Information of China (English)

    Jiang Dongmei; Zhou Yuanfang; Lu Genfa

    2006-01-01

    The main causes of non-point source pollution in Taihu Lake are the improper ways of crop production, animal husbandry, and daily runoff. The paper discusses the relationship between countrywomen and non-point source pollution control by 731 questionnaires in Weidu village and 466 questionnaires in Dapu Town. The roles of countrywomen have changed in families and they have close relationship with non-point source pollution. Furthermore, we discuss the possibility and methods of organizing countrywomen in non-point source pollution control.

  10. Using site-specific soil samples as a substitution for improved hydrological and nonpoint source predictions.

    Science.gov (United States)

    Chen, Lei; Wang, Guobo; Zhong, Yucen; Zhao, Xin; Shen, Zhenyao

    2016-08-01

    Soil databases are one of the most important inputs for watershed models, and the quality of soil properties affects how well a model performs. The objectives of this study were to (1) quantify the sensitivity of model outputs to soil properties and to (2) use site-specific soil properties as a substitution for more accurate hydrological and nonpoint source (H/NPS) predictions. Soil samples were collected from a typical mountainous watershed in China, and the impacts of soil sample parameters on H/NPS predictions were quantified using the Soil and Water Assessment Tool (SWAT). The most sensitive parameters related to predicting flow, sediment, and total phosphorus (TP) mainly were the soil hydrological, the channel erosion processes, and the initial soil chemical environment, respectively. When the site-specific soil properties were used, the uncertainties (coefficient of variation) related to predicting the hydrology, sediment and TP decreased by 75∼80 %, 75∼84 %, and 46∼61 %, respectively. Based on changes in the Nash-Sutcliff coefficient, the model performance improved by 4.9 and 19.45 % for the hydrological and sediment model, accordingly. However, site-specific soil properties did not contribute to better TP predictions because of the high spatial variability of the soil P concentrations across the large watershed. Thus, although site-specific soil samples can be used to obtain more accurate H/NPS predictions, more sampling sites are required to apply this method in large watersheds.

  11. Evaluating the impacts of soil data on hydrological and nonpoint source pollution prediction.

    Science.gov (United States)

    Chen, Lei; Wang, Guobo; Zhong, Yucen; Shen, Zhenyao

    2016-09-01

    Soil data are one key input for most hydrological and nonpoint source (H/NPS) models, and quantifying the error transmission from soil data to H/NPS predictions is of great importance. In this study, two typical soil datasets were compared using the Soil and Water Assessment Tool (SWAT) in a typical mountainous watershed, the Three Gorges Reservoir Region, China. Besides, the effects of soil data resolution were evaluated, and the error transmission from soil data to watershed management strategy was assessed. The results indicate that model outputs are not sensitive to changes of soil data resolution but the choice of soil data greatly impacts the application of watershed models, in terms of the goodness-of-fit indicator, predicted data and related uncertainty. This soil data-induced error would be inevitably magnified from the flow simulation to the NPS prediction stage. This study could indicate that the choice of soil data will lead to significant differences in management schemes for specific pollution periods. These results provide information on the impacts of soil data on the functionality of watershed models and valuable information for the appropriateness of each soil database.

  12. [A landscape ecological approach for urban non-point source pollution control].

    Science.gov (United States)

    Guo, Qinghai; Ma, Keming; Zhao, Jingzhu; Yang, Liu; Yin, Chengqing

    2005-05-01

    Urban non-point source pollution is a new problem appeared with the speeding development of urbanization. The particularity of urban land use and the increase of impervious surface area make urban non-point source pollution differ from agricultural non-point source pollution, and more difficult to control. Best Management Practices (BMPs) are the effective practices commonly applied in controlling urban non-point source pollution, mainly adopting local repairing practices to control the pollutants in surface runoff. Because of the close relationship between urban land use patterns and non-point source pollution, it would be rational to combine the landscape ecological planning with local BMPs to control the urban non-point source pollution, which needs, firstly, analyzing and evaluating the influence of landscape structure on water-bodies, pollution sources and pollutant removal processes to define the relationships between landscape spatial pattern and non-point source pollution and to decide the key polluted fields, and secondly, adjusting inherent landscape structures or/and joining new landscape factors to form new landscape pattern, and combining landscape planning and management through applying BMPs into planning to improve urban landscape heterogeneity and to control urban non-point source pollution.

  13. Reducing non-point source pollution with enhancing infiltration

    Institute of Scientific and Technical Information of China (English)

    MU Huan-zhen; ZHENG Tao; HUANG Yan-chu; ZHANG Chun-ping; LIU Chen

    2006-01-01

    The rainfall system was set up on a slope land, which was used with some materials to enhance soil infiltration. The results showed that it was effective to enhance the infiltration of rainwater in soil and reduce the pollutants of surface runoff. After the soil meliorated by the lignin polymer and zeolite, runoff was delayed about 10 min and reduced by 44.40%-50.00%, synchronously, the pollutant loads, such as total suspended solids (TSS), chemical oxygen demand by ditromate (CODCr), total nitroger (TN) and total phosphorus (TP), were reduced on averages by 44.58%, 37.80%, 51.62% and 44.11%, respectively. It is an available technique to control the pollution of non-point source from sources.

  14. Modified Weighting for Calculating the Average Concentration of Non-Point Source Pollutant

    Institute of Scientific and Technical Information of China (English)

    牟瑞芳

    2004-01-01

    The concentration of runoff depends upon that of soil loss and the latter is assumed to be linear to the value of EI that equals the product of total storm energy E times the maximum 30-min intensity I30 for a given rainstorm. Usually, the maximum accumulative amount of rain for a rainstorm might bring on the maximum amount of runoff, but it does not equal the maximum erosion and not always lead the maximum concentration. Thus, the average concentration weighted by amount of runoff is somewhat unreasonable. An improvement for the calculation method of non-point source pollution load put forward by professor Li Huaien is proposed. In replacement of the weight of runoff, EI value of a single rainstorm is introduced as a new weight. An example of Fujing River watershed shows that its application is effective.

  15. Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps and human health hazards associated with uranium exploration and mining, Red, White, and Fry Canyons, southeastern Utah, 2007

    Science.gov (United States)

    Beisner, Kimberly R.; Marston, Thomas M.; Naftz, David L.; Snyder, Terry; Freeman, Michael L.

    2010-01-01

    During May, June, and July 2007, 58 solid-phase samples were collected from abandoned uranium mine waste dumps, background sites, and adjacent streambeds in Red, White, and Fry Canyons in southeastern Utah. The objectives of this sampling program were to (1) assess the nonpoint-source chemical loading potential to ephemeral and perennial drainage basins from uranium waste dumps and (2) assess potential effects on human health due to recreational activities on and around uranium waste dumps on Bureau of Land Management property. Uranium waste-dump samples were collected using solid-phase sampling protocols. After collection, solid-phase samples were homogenized and extracted in the laboratory using a leaching procedure. Filtered (0.45 micron) water samples were obtained from the field leaching procedure and were analyzed for major and trace elements at the Inductively Coupled Plasma-Mass Spectrometry Metals Analysis Laboratory at the University of Utah. A subset of the solid-phase samples also were digested with strong acids and analyzed for major ions and trace elements at the U.S. Geological Survey Geologic Division Laboratory in Denver, Colorado. For the initial ranking of chemical loading potential for uranium waste dumps, results of leachate analyses were compared with existing aquatic-life and drinking-water-quality standards. To assess potential effects on human health, solid-phase digestion values for uranium were compared to soil screening levels (SSL) computed using the computer model RESRAD 6.5 for a probable concentration of radium. One or more chemical constituents exceeded aquatic life and drinking-water-quality standards in approximately 64 percent (29/45) of the leachate samples extracted from uranium waste dumps. Most of the uranium waste dump sites with elevated trace-element concentrations in leachates were located in Red Canyon. Approximately 69 percent (31/45) of the strong acid digestible soil concentration values were greater than a calculated

  16. Management of unregulated agricultural nonpoint sources through water quality trading market.

    Science.gov (United States)

    Mahjoobi, Emad; Sarang, Amin; Ardestani, Mojtaba

    2016-11-01

    Water quality trading (WQT) could be an innovative policy to incentivize farmers to implement best management practices (BMPs) for their activities. This study focused on assessment of involving unregulated agricultural nonpoint sources (NPS) into the WQT market in Gharesoo watershed in the west of Iran. It also proposes a methodology to determine location-based trading ratios as well as environmental penalty cost to achieve a more well-designed market structure. Trading activities in different scenarios were described by trading volume (TV), participation rate (PR), total exchanged value (TEV), and other market parameters in order to achieve a better comparison of market performance. Results showed that, by applying NPS to the Gharesoo watershed, total phosphorous (TP) trading market could increase TV, PR, and TEV up to 11, 1.7 and 7.5 times, respectively, depending on which level of BMPs are implemented by them. Additionally, it could save 29% of the total cost of implementing a TP total maximum daily load in this watershed compared to the 'command and control' approach. Furthermore, the agricultural sector could profit by $5.49 million (or $75/ha) by choosing solutions such as terrace systems and filter strips to register into the market. This profit can be allocated to the development of new agricultural technologies.

  17. User's Guide for the Agricultural Non-Point Source (AGNPS) Pollution Model Data Generator

    Science.gov (United States)

    Finn, Michael P.; Scheidt, Douglas J.; Jaromack, Gregory M.

    2003-01-01

    BACKGROUND Throughout this user guide, we refer to datasets that we used in conjunction with developing of this software for supporting cartographic research and producing the datasets to conduct research. However, this software can be used with these datasets or with more 'generic' versions of data of the appropriate type. For example, throughout the guide, we refer to national land cover data (NLCD) and digital elevation model (DEM) data from the U.S. Geological Survey (USGS) at a 30-m resolution, but any digital terrain model or land cover data at any appropriate resolution will produce results. Another key point to keep in mind is to use a consistent data resolution for all the datasets per model run. The U.S. Department of Agriculture (USDA) developed the Agricultural Nonpoint Source (AGNPS) pollution model of watershed hydrology in response to the complex problem of managing nonpoint sources of pollution. AGNPS simulates the behavior of runoff, sediment, and nutrient transport from watersheds that have agriculture as their prime use. The model operates on a cell basis and is a distributed parameter, event-based model. The model requires 22 input parameters. Output parameters are grouped primarily by hydrology, sediment, and chemical output (Young and others, 1995.) Elevation, land cover, and soil are the base data from which to extract the 22 input parameters required by the AGNPS. For automatic parameter extraction, follow the general process described in this guide of extraction from the geospatial data through the AGNPS Data Generator to generate input parameters required by the pollution model (Finn and others, 2002.)

  18. Game Analysis and Strategy Research of Farmers Involving in the Agricultural Non-Point Source Pollution Prevention and Control

    OpenAIRE

    Zhou Zaohong

    2013-01-01

    This thesis applies game theory to make a quantitative analysis of the outward problem of the agricultural non-point source pollution and discusses the basic starting point to study the agricultural non-point source pollution prevention and control and furthermore researches the measures and recommendations of agricultural non-point source pollution prevention and control.

  19. Game Analysis and Strategy Research of Farmers Involving in the Agricultural Non-Point Source Pollution Prevention and Control

    Directory of Open Access Journals (Sweden)

    Zhou Zaohong

    2013-06-01

    Full Text Available This thesis applies game theory to make a quantitative analysis of the outward problem of the agricultural non-point source pollution and discusses the basic starting point to study the agricultural non-point source pollution prevention and control and furthermore researches the measures and recommendations of agricultural non-point source pollution prevention and control.

  20. Estimating the susceptibility of surface water in Texas to nonpoint-source contamination by use of logistic regression modeling

    Science.gov (United States)

    Battaglin, William A.; Ulery, Randy L.; Winterstein, Thomas; Welborn, Toby

    2003-01-01

    In the State of Texas, surface water (streams, canals, and reservoirs) and ground water are used as sources of public water supply. Surface-water sources of public water supply are susceptible to contamination from point and nonpoint sources. To help protect sources of drinking water and to aid water managers in designing protective yet cost-effective and risk-mitigated monitoring strategies, the Texas Commission on Environmental Quality and the U.S. Geological Survey developed procedures to assess the susceptibility of public water-supply source waters in Texas to the occurrence of 227 contaminants. One component of the assessments is the determination of susceptibility of surface-water sources to nonpoint-source contamination. To accomplish this, water-quality data at 323 monitoring sites were matched with geographic information system-derived watershed- characteristic data for the watersheds upstream from the sites. Logistic regression models then were developed to estimate the probability that a particular contaminant will exceed a threshold concentration specified by the Texas Commission on Environmental Quality. Logistic regression models were developed for 63 of the 227 contaminants. Of the remaining contaminants, 106 were not modeled because monitoring data were available at less than 10 percent of the monitoring sites; 29 were not modeled because there were less than 15 percent detections of the contaminant in the monitoring data; 27 were not modeled because of the lack of any monitoring data; and 2 were not modeled because threshold values were not specified.

  1. Evaluation of nonpoint-source contamination, Wisconsin: Land-use and Best-Management-Practices inventory, selected streamwater-quality data, urban-watershed quality assurance and quality control, constituent loads in rural streams, and snowmelt-runoff analysis, water year 1994

    Science.gov (United States)

    Walker, J.F.; Graczyk, D.J.; Corsi, S.R.; Owens, D.W.; Wierl, J.A.

    1995-01-01

    The objective of the watershed-management evaluation monitoring program in Wisconsin is to evaluate the effectiveness of best-management practices (BMP) for controlling nonpoint-source contamination in rural and urban watersheds. This report is an annual summary of the data collected for the program by the U.S Geological Survey and a report of the results of several different detailed analyses of the data. A land-use and BMP inventory is ongoing for 12 evaluation monitoring projects to track the sources of nonpoint-source pollution in each watershed and to document implementation of BMP's that may cause changes in the water quality of streams. Updated information is gathered each year, mapped, and stored in a geographic-information-system data base. Summaries of data collected during water years 1989-94 are presented. A water year is the period beginning October 1 and ending September 30; the water year is designated by the calendar year in which it ends. Suspended-sediment and total-phosphorus data (storm loads and annual loads) are summarized for eight rural sites. For all sites, the annual suspended-sediment or suspended-solids load for water year 1993 exceeded the average for the period of data collection; the minimum annual loads were transported in water year 1991 or 1992. Continuous dissolved-oxygen data were collected at seven rural sites during water year 1994. Data for water years 1990-93 are summarized and plotted in terms of percentage of time that a particular concentration is equaled or exceeded. Dissolved-oxygen concentrations in four streams were less than 9 mg/L at least 50 percent of the time, a condition that fails to meet suggested criterion for coldwater streams. The dissolved-oxygen probability curve for one of the coldwater streams is markedly different than the curves for the other streams, perhaps because of differences in aquatic biomass. Blank quality-assurance samples were collected at two of the urban evaluation monitoring sites to

  2. Emerging policies to control nonpoint source pollution of groundwater

    Science.gov (United States)

    Harter, T.

    2014-12-01

    Water quality impairment is among the highest ranking public issues of concern in the developed world. While, in Europe and North America, many water quality programs have been put in place over the past half century, regulators difficulties tackling the geographically most widespread water quality degradation in these regions: pollution of groundwater (as opposed to surface water) from diffuse sources (as opposed to point sources), including contamination with nitrate (affecting drinking water supplies in rural areas and at the rural-urban interface) and salinity (affecting irrigation water quality). Other diffuse pollution contaminants include pesticides and emerging contaminants (e.g., antibiotics and pathogens from animal farming). The geographic and hydrologic characteristics of nonpoint source pollution of groundwater are distinctly different from other types of water pollution: individually liable sources are contiguous across the landscape, and internally heterogeneous in space and time. On annually aggregated time scales (most relevant to groundwater), sources are continuously emitting pollution, while pollution levels typically do not exceed MCLs by less than a factor 2. An analysis of key elements of existing water pollution policies to control groundwater pollution from diffuse sources demonstrates the lack of both, science and institutional capacity, while existing point-source approaches cannot be applied toward the control of diffuse pollution to groundwater. For the latter, a key to a successful policy is a tiered, three-way monitoring program based on proxy compliance metrics instead of direct measurement of pollutant discharge, research linking actual pollutant discharges to proxy metrics, and long-term regional groundwater monitoring to establish large scale, long-term trends. Several examples of emerging regulations from California and the EU are given to demonstrate these principles.

  3. Long-term agricultural non-point source pollution loading dynamics and correlation with outlet sediment geochemistry

    Science.gov (United States)

    Ouyang, Wei; Jiao, Wei; Li, Xiaoming; Giubilato, Elisa; Critto, Andrea

    2016-09-01

    Some agricultural non-point source (NPS) pollutants accumulate in sediments in the outlet sections of watersheds. It is crucial to evaluate the historical interactions between sediment properties and watershed NPS loading. Therefore, a sediment core from the outlet of an agricultural watershed was collected. The core age was dated using the 210Pb method, and sedimentation rates were determined using the constant rate of supply (CRS) model. The total nitrogen (TN), total phosphorus (TP), Cd, Pb, Cu, Ni and Cr accumulations in the sediment generally showed fluctuating increases, with the highest sedimentation fluxes all occurring in approximately 1998. The measurement of specific mass sedimentation rates reflected a record of watershed soil erosion dynamics. Using SWAT (Soil and Water Assessment Tool) to simulate long-term watershed agricultural NPS pollution loadings, the historical interactions between sediment properties and NPS loadings were further evaluated. The N leaching process weakened these interactions, but the historical accumulations of TP and heavy metals in sediments generally correlated well with watershed NPS TP loading. The regression analysis suggested that Pb and Cr were the most suitable indexes for assessing long-term NPS TN and TP pollution, respectively. Assessing the NPS loading dynamics using the vertical characteristics of sediment geochemistry is a new method.

  4. Parameter uncertainty analysis of non-point source pollution from different land use types.

    Science.gov (United States)

    Shen, Zhen-yao; Hong, Qian; Yu, Hong; Niu, Jun-feng

    2010-03-15

    Land use type is one of the most important factors that affect the uncertainty in non-point source (NPS) pollution simulation. In this study, seventeen sensitive parameters were screened from the Soil and Water Assessment Tool (SWAT) model for parameter uncertainty analysis for different land use types in the Daning River Watershed of the Three Gorges Reservoir area, China. First-Order Error Analysis (FOEA) method was adopted to analyze the effect of parameter uncertainty on model outputs under three types of land use, namely, plantation, forest and grassland. The model outputs selected in this study consisted of runoff, sediment yield, organic nitrogen (N), and total phosphorus (TP). The results indicated that the uncertainty conferred by the parameters differed among the three land use types. In forest and grassland, the parameter uncertainty in NPS pollution was primarily associated with runoff processes, but in plantation, the main uncertain parameters were related to runoff process and soil properties. Taken together, the study suggested that adjusting the structure of land use and controlling fertilizer use are helpful methods to control the NPS pollution in the Daning River Watershed.

  5. Nonpoint Source Pollution Control Projects Grants (Section 319) - 2008 active projects

    Data.gov (United States)

    U.S. Environmental Protection Agency — The California Nonpoint Source (NPS) Program allocates about $4.5 million of CWA Section 319 funding from the U.S. Environmental Protection Agency annually to...

  6. EPA Office of Water (OW): Nonpoint Source Projects NHDPlus Indexed Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — GRTS locational data for nonpoint source projects. GRTS locations are coded onto NHDPlus v2.1 flowline features to create point and line events or coded onto NHDPlus...

  7. Techniques for Tracking, Evaluating, and Reporting the Implementation of Nonpoint Source Control Measures - Forestry

    Science.gov (United States)

    This guidance is intended to assist state, regional, and local environmental professionals in tracking the implementation of best management practices (BMPs) used to control nonpoint source pollution generated by forestry practices.

  8. Evaluation of the Agricultural Non-point Source Pollution in Chongqing Based on PSR Model

    Institute of Scientific and Technical Information of China (English)

    Hanwen; ZHANG; Xinli; MOU; Hui; XIE; Hong; LU; Xingyun; YAN

    2014-01-01

    Through a series of exploration based on PSR framework model,for the purpose of building a suitable Chongqing agricultural nonpoint source pollution evaluation index system model framework,combined with the presence of Chongqing specific agro-environmental issues,we build a agricultural non-point source pollution assessment index system,and then study the agricultural system pressure,agro-environmental status and human response in total 3 major categories,develope an agricultural non-point source pollution evaluation index consisting of 3 criteria indicators and 19 indicators. As can be seen from the analysis,pressures and responses tend to increase and decrease linearly,state and complex have large fluctuations,and their fluctuations are similar mainly due to the elimination of pressures and impact,increasing the impact for agricultural non-point source pollution.

  9. Predicting precipitation on nonpoint source pollutant exports in the source area of the Liao River, China.

    Science.gov (United States)

    Wang, Y; Bian, J M; Wang, S N; Nie, S Y

    The source area of the Liao River is an important grain growing area in China which experiences serious problems with agricultural nonpoint source pollution (NPS) which is impacting the regional economy and society. In order to address the water quality issues it is necessary to understand the spatial distribution of NPS in the Liao River source area. This issue has been investigated by coupling a wavelet artificial neural network (WA-ANN) precipitation model with a soil and water assessment tool (SWAT) model to assess the export of nonpoint source pollutants from the Liao River source area. The calibration and validation of these models are outlined. The WA-ANN models and the SWAT model were run to generate the spatial distribution of nonpoint source nutrient (nitrogen and phosphorus) exports in the source area of the Liao River. It was found that the SWAT model identified the sub-catchments which not only receive high rainfall but are also densely populated with high agricultural production from dry fields and paddy fields, which are large users of pesticides and chemical fertilizer, as the primary source areas for nutrient exports. It is also concluded that the coupled WA-ANN models and the SWAT model provide a tool which will inform the identification of NPS issues and will facilitate the identification of management practices to improve the water environments in the source area of the Liao River.

  10. Assessment of Economic Loss Caused by Agricultural Non-point Source Nutrient Loss

    Institute of Scientific and Technical Information of China (English)

    FAN Liang-qian; CHEN Feng-hui

    2012-01-01

    Taking Zhejiang Province as an example, we use the JOHNES export coefficient model to estimate the total nitrogen (TN) and total phosphorus (TP) load of agricultural planting, livestock and poultry breeding and rural living non-point source in 2009. Based on the protection cost method in environmental economics, we quantitatively assess the economic loss caused by these three types of non-point source nutrient loss. The results show that in TN non-point source load, the load of land for planting accounts for 57.48%, the load of rural living accounts for 30.22%, and the load of livestock and poultry breeding accounts for 12.30%; in TP non-point source load, the load of rural living accounts for 46.18%, the load of livestock and poultry breeding accounts for 29.00%, and the load of land for planting accounts for 24.82%. The economic loss arising from the agricultural non-point source nutrient loss is equivalent to 2.329 424 7 billion yuan per year (the loss from land for planting accounts for 55.46%; the loss from rural living accounts for 31.21%; the loss from livestock and poultry breeding accounts for 13.33%). It indicates that in order to reduce the loss arising from agricultural non-point source nutrient loss, we should pay attention to controlling the land for planting and rural living source.

  11. [Impacts of the urbanization on waters non-point source pollution].

    Science.gov (United States)

    Yang, Liu; Ma, Ke-Ming; Guo, Qing-hai; Zhao, Jing-zhu

    2004-11-01

    Non-point source (NPS) pollution is the prominent source of water pollution in many countries, included America and China, of the world. Urban NPS pollution was attached little importance for long, compared with agriculture NPS pollution. While urbanization is the dominant form of land-use change in terms of impacts on water quality, the hydrology, other physical properties of watersheds as well as their NPS pollution potential at present. The formation of urban NPS pollution of water could be described by "source-process-sink". Urbanization has changed the source, process and sink of urban NPS pollution. A review was conducted on the international researches of urbanization impacts on NPS pollution in urban water environment from the point of view of "describe-predict and evaluation-application". The studies of urbanization impacts on urban NPS pollution were focused on modeling the process of urban NPS pollution by hydrologic model, predicting the pollutants load of NPS pollution. It is a fresh methodology that the relationship between urbanization and urban NPS pollution of water was analyzed by the method of landscape change and ecological process. The research on temporal-spatial comprehensive impacts of landscape pattern changes, led by urbanization, on the urban NPS pollution will be one of the hotspots.

  12. Assessment of nonpoint-source runoff in a stream using in situ and laboratory approaches

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, K.A.; Burton, G.A. Jr.

    1999-12-01

    Anthropogenic activities that change a watershed can cause adverse impacts to receiving water. Agricultural and urban runoff are the two leading causes of surface-water impairment in the US. When assessing pollutant sources and their effects on aquatic ecosystems, and prior to implementing source controls, it is necessary to define the systems stressors and receptors of exposure. Toxicity assays are a key component to integrative assessments that include habitat (physical), chemical, and indigenous community characterization. Traditional toxicity assay methods and the use of water-quality criteria are often inappropriate because of exposure design and effect assumptions. Hyalella azteca and Chironomus tentans were exposed in situ for varying time periods during both low- and high-flow conditions to determine the effect of urban and agricultural runoff. Short-term chronic and acute toxicity of urban and agricultural runoff was then measured in the laboratory and related to in situ test results. Nonpoint-source (NPS) runoff from urban areas was often more acutely toxic to organisms in the laboratory as compared to in situ results. Conversely, toxicity to the organisms was greater at the agricultural site during in situ exposures when compared to laboratory. In situ assays were an essential and integral component of NPS runoff assessments. They provided unique information that complemented laboratory toxicity, habitat, benthic community, and physicochemical characterizations.

  13. Study on Management and Control of Nonpoint Source Pollution from Urban Surface Runoff

    Institute of Scientific and Technical Information of China (English)

    Chen Keliang; Zhu Xiaodong; Wang Xianghua; Ma Yan

    2007-01-01

    Urbanization is the dominant form of land-use change in terms of impacts on water quality, hydrology, physical properties of watersheds and their nonpoint source (NPS) pollution potential at present. Urbanization has changed the source, process and sink of urban NPS pollution, especially raised the pollution load of urban runoff NPS in receiving water. Urban runoff pollution is a hot spot of research on NPS. This paper analyzed type,source and harm of the NPS pollutants of urban runoff and its influence on the receiving water. Through estimating NPS pollution load of urban runoff and summarizing the law and characteristics of urban runoff NPS systemically, study on management and control of urban runoff NPS pollution was focused on the application of BMPs (best management practices). It is a fresh methodology that management and control on NPS pollution from urban surface runoff was analyzed by methods of landscape ecology,environmental economics and environmental management. The paper provided a scientific reference for mitigating urban water environment pressure and an effective method for management and control of NPS pollution from urban surface runoff..

  14. 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.

  15. Loss coefficient of nitrogenous non-point source pollution under various precipitation conditions

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this study,calibrations of non-point source (NPS) pollution models are performed based on Black River basin historical real-time runoff data,sedimentation record data,and NPS sources survey information.The concept of NPS loss coefficient for the watershed or the loss coefficients (LC) for simplicity is brought up by examining NPS build-up and migration processes along riverbanks in natural river systems.The historical data is used for determining the nitrogenous NPS loss coefficient for five land use types including farmland,urban land,grassland,shrub land,and forest under different precipitation conditions.The comparison of outputs from Soil and Water Assessment Tool (SWAT) model and coefficient export method showed that both methods could obtain reasonable LC.The high Pearson correlation coefficient (0.94722) between those two sets of calculation results justified the consistency of those two models.Another result in the study is that different combinations of precipitation condition and land use types could significantly affect the calculated loss coefficient.As for the adsorptive nitrogen,the order of impact on LC for different land use types can be sorted as:farm land > urban land > grassland > shrub land > forest while the order was farmland > grass land > shrub land > forest > urban land for soluble nitrogen.

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

    Science.gov (United States)

    Wu, Yiping; Liu, Shuguang

    2012-09-01

    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.

  17. Roofing as a source of nonpoint water pollution.

    Science.gov (United States)

    Chang, Mingteh; McBroom, Matthew W; Scott Beasley, R

    2004-12-01

    new wood-shingle roofs were significantly higher than those from aged roofs of a previous study. The study demonstrated that roofs could be a serious source of nonpoint water pollution. Since Zn is the most serious water pollutant and wood shingle is the worst of the four roof types, using less compounds and materials associated with Zn along with good care and maintenance of roofs are critical in reducing Zn pollution in roof runoff.

  18. On the applicability of SWAT model to the nonpoint source pollution in the watershed of the three-gorge reservoir%SWAT模型在三峡库区流域非点源污染模拟的适用性研究

    Institute of Scientific and Technical Information of China (English)

    陈媛; 郭秀锐; 程水源; 王征; 秦翠红; 陆瑾; 高继军

    2012-01-01

    This paper intends to study the applicability of SWAT model to the non-point Source pollution in the watershed of the Three-Gorge Reservoir. The so-called SWAT (Soil and Water Assessment Tool) model is a model we have developed in hoping to be applied and adapted to the macro-scale watershed, in the TGR area as a case study. The said model has been established under the support of the Geographic Information System (ArcGIS) as well as the spatial dataset such as DEM(digital elevation model), land-use map and so on. In our research, we have studied the data of hydrolngical and water quality in the TGR area from 2002 to 2008 for simulated calibration and validation. On the whole, our simulation proves to be successful, for the indicator ENS ( Nash-Suttclife efficiency) for stream flow in most cases was above 0.9, whereas the Ens for sediment was from 0.46 to 0.9 though the ENS for nutrient in some individual cases was less than 0.36. We have also studied the correlation between the precipitation and the surface runoff, sediment load, nutrient load in the TGR area, too. The results of our simulated investigation have shown that the surface runoff and sediment load were both closely related with the precipitation, except that the peak of sediment load took place earlier than that of surface runoff in April or May occasionally. The reason for the sediment situation is perhaps that it is because of the large amounts of the soil loss caused by the tillage and precipitation activities during the season. As to the nutrient load, especially, the TP, the consequence seems also relevant to the sediment load in comparison with the surface runoff. And, finally, we have also analyzed the pollution loads generated by the different landuse types in the area. When we worked out the order of the average pollution load for different landuse situations, we have found that the most serious non-point sources of pollution are the crop fileds in the TGR area. So it is urgent to improve the

  19. mpacts of Agricultural Non-point Pollution on Water-source Area in Songhua Dam

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    [Objective] The aim was to research impacts of agricultural non-point pol- lution on water-source region in Songhua Dam, laying foundation for control of water pollution and scientific protection of water-source region. [Method] Water in Muyang River, lengshui River and Zizania aquatica region were sampled to measure content of pollutants in water and conclude relation between water contamination and agri- cultural non-point pollution to find the major cause of pollution. [Result] Organic pollu- tant in Muyang River was higher; N and P contents in Lengshui River were higher; the measured indices in Zizania aquatica region excessively exceeded related stan- dard. [Conclusion] The chemical fertilizers and pesticides are the toxic materials lead- ing to water contamination and constitute a major cause of pollution in Songhua Dam water-source region. Agricultural non-point pollution should be controlled in a scientific way.

  20. The impact of information on behavior under an ambient-based policy for regulating nonpoint source pollution

    Science.gov (United States)

    Miao, Haoran; Fooks, Jacob R.; Guilfoos, Todd; Messer, Kent D.; Pradhanang, Soni M.; Suter, Jordan F.; Trandafir, Simona; Uchida, Emi

    2016-05-01

    Stemming from Segerson [1988], literature on nonpoint source pollution shows that ambient-based regulatory policies can induce polluters in a common watershed to comply with an exogenously determined pollution standard. This study uses laboratory economic experiments in a spatially heterogeneous setting to test the effectiveness of an ambient tax/subsidy policy in a setting with realistic in-stream nutrient transport dynamics when varying levels of sensor information on ambient pollution are available to the agents and the regulator. We find that increasing the frequency of ambient monitoring improves the spatial allocation of emissions reductions. In particular, with more frequent monitoring, the ambient-based policy induces firms further from the monitoring point to reduce emissions significantly more than downstream firms. Overall, the results suggest that enhanced temporal resolution of monitoring leads to efficiency gains.

  1. NASA-Modified Precipitation Products to Improve EPA Nonpoint Source Water Quality Modeling for the Chesapeake Bay

    Science.gov (United States)

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The Environmental Protection Agency (EPA) has estimated that over 20,000 water bodies within the United States do not meet water quality standards. Ninety percent of the impairments are typically caused by nonpoint sources. One of the regulations in the Clean Water Act of 1972 requires States to monitor the Total Maximum Daily Load (TMDL), or the amount of pollution that can be carried by a water body before it is determined to be "polluted", for any watershed in the U.S.. In response to this mandate, the EPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a Decision Support Tool (DST) for assessing pollution and to guide the decision making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program -- Fortran (HSPF), computes daily stream flow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA modified/NOAA precipitation data. Using these data within HSPF, stream flow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better stream flow statistics and, ultimately, in improved water quality assessment.

  2. Nonpoint-Source Pollution Issues. January 1990-November 1994. QB 95-01. Quick Bibliography Series.

    Science.gov (United States)

    Makuch, Joe

    Citations in this bibliography are intended to be a substantial resource for recent investigations (January 1990-November 1994) on nonpoint source pollution and were obtained from a search of the National Agriculture Library's AGRICOLA database. The 196 citations are indexed by author and subject. A representation of the search strategy is…

  3. Another Look at the Income Elasticity of Non-point Source Air Pollutants: A Semiparametric Approach

    NARCIS (Netherlands)

    Roy, N.; Kooten, van G.C.

    2004-01-01

    In this paper, a semiparametric model is used to examine the relationship between pollution and income for three non-point source pollutants. Statistical tests reject the quadratic specification in favor of the semiparametric model in all cases. However, the results do not support the inverted-U hyp

  4. 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.

  5. [Bivariate statistical model for calculating phosphorus input loads to the river from point and nonpoint sources].

    Science.gov (United States)

    Chen, Ding-Jiang; Sun, Si-Yang; Jia, Ying-Na; Chen, Jia-Bo; Lü, Jun

    2013-01-01

    Based on the hydrological difference between the point source (PS) and nonpoint source (NPS) pollution processes and the major influencing mechanism of in-stream retention processes, a bivariate statistical model was developed for relating river phosphorus load to river water flow rate and temperature. Using the calibrated and validated four model coefficients from in-stream monitoring data, monthly phosphorus input loads to the river from PS and NPS can be easily determined by the model. Compared to current hydrologica methods, this model takes the in-stream retention process and the upstream inflow term into consideration; thus it improves the knowledge on phosphorus pollution processes and can meet the requirements of both the district-based and watershed-based wate quality management patterns. Using this model, total phosphorus (TP) input load to the Changle River in Zhejiang Province was calculated. Results indicated that annual total TP input load was (54.6 +/- 11.9) t x a(-1) in 2004-2009, with upstream water inflow, PS and NPS contributing to 5% +/- 1%, 12% +/- 3% and 83% +/- 3%, respectively. The cumulative NPS TP input load during the high flow periods (i. e. , June, July, August and September) in summer accounted for 50% +/- 9% of the annual amount, increasing the alga blooming risk in downstream water bodies. Annual in-stream TP retention load was (4.5 +/- 0.1) t x a(-1) and occupied 9% +/- 2% of the total input load. The cumulative in-stream TP retention load during the summer periods (i. e. , June-September) accounted for 55% +/- 2% of the annual amount, indicating that in-stream retention function plays an important role in seasonal TP transport and transformation processes. This bivariate statistical model only requires commonly available in-stream monitoring data (i. e. , river phosphorus load, water flow rate and temperature) with no requirement of special software knowledge; thus it offers researchers an managers with a cost-effective tool for

  6. Assessing the effects of non-point source pollution on American Samoa's coral reef communities.

    Science.gov (United States)

    Houk, Peter; Didonato, Guy; Iguel, John; Van Woesik, Robert

    2005-08-01

    Surveys were completed on Tutuila Island, American Samoa, to characterize reef development and assess the impacts of non-point source pollution on adjacent coral reefs at six sites. Multivariate analyses of benthic and coral community data found similar modern reef development at three locations; Aoa, Alofau, and Leone. These sites are situated in isolated bays with gentle sloping foundations. Aoa reefs had the highest estimates of crustose coralline algae cover and coral species richness, while Leone and Alofau showed high abundances of macroalgae and Porites corals. Aoa has the largest reef flat between watershed discharge and the reef slope, and the lowest human population density. Masefau and Fagaalu have a different geomorphology consisting of cemented staghorn coral fragments and steep slopes, however, benthic and coral communities were not similar. Benthic data suggest Fagaalu is heavily impacted compared with all other sites. Reef communities were assessed as bio-criteria indicators for waterbody health, using the EPA aquatic life use support designations of (1) fully supportive, (2) partially supportive, and (3) non-supportive for aquatic life. All sites resulted in a partially supportive ranking except Fagaalu, which was non-supportive. The results of this rapid assessment based upon relative benthic community measures are less desirable than long-term dataset analyses from monitoring programs, however it fills an important role for regulatory agencies required to report annual waterbody assessments. Future monitoring sites should be established to increase the number of replicates within each geological and physical setting to allow for meaningful comparisons along a gradient of hypothesized pollution levels.

  7. The Degree of Farmers’ Cognition on Non-point Source Pollution:Based on the Statistical Analysis of 453 Farmers

    Institute of Scientific and Technical Information of China (English)

    Qian; BI; Huaiye; WANG; Jue; PENG

    2014-01-01

    With the rapid development of modern agriculture,agricultural non-point source pollution becomes increasingly serious in China,improving farmers’ environmental protection consciousness plays a very important role in the reduction of agricultural non-point source pollution.Therefore,this investigation and study chooses rural areas of five counties from Chongqing city and Zhejiang province as our samples,our investigation and statistical analysis includes the following four aspects:farmers’ cognition on non-point source pollution concept,farmers’ cognition to rural environment satisfaction,farmers’ cognition on non-point source pollution in agricultural production and farmers’ cognition on the consequences of agricultural non-point source pollution and the effects on ecological environment.The analysis and conclusions of farmers’ consciousness cognition on agricultural non-point source pollution,provides the supports in theory and practice for optimizing the behavior of farmers,promoting the management of agricultural non-point source pollution and implementing new rural construction goal.

  8. MODELING OF SEDIMENT AND NONPOINT SOURCE POLLUTANT YIELD

    Institute of Scientific and Technical Information of China (English)

    Huai'en LI; Xiaokang Hong; Bing SHEN

    2001-01-01

    For water and soil conservation and water pollution control, it is very important to simulate and predict the load of sediment and pollutant during storm-runoff. On the basis of analyzing the simultaneous measurements of flow, sediment and pollutants observed at watershed outlet, a practical sediment yield model is developed by standardizing the load rate. The results show that the standardized pollutant yield equals effective rainfall and the process of effective load yield is the same as effective rainfall hyetograph. Comparison with measured data show that this model is applicable to various pollutants.

  9. NASA-modified precipitation products to improve USEPA nonpoint source water quality modeling for the Chesapeake Bay.

    Science.gov (United States)

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The USEPA has estimated that over 20,000 water bodies within the United States do not meet water quality standards. One of the regulations in the Clean Water Act of 1972 requires states to monitor the total maximum daily load, or the amount of pollution that can be carried by a water body before it is determined to be "polluted," for any watershed in the United States (Copeland, 2005). In response to this mandate, the USEPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a decision support tool for assessing pollution and to guide the decision-making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program-Fortran (HSPF), computes continuous streamflow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events, especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA-modified/NOAA precipitation data. Using these data within HSPF, streamflow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better streamflow statistics and, potentially, in improved water quality assessment.

  10. Percentage of probability of nonpoint-source nitrate contamination of recently recharged ground water in the High Plains aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents the percentage of probability of nonpoint-source nitrate contamination (greater than the proposed background concentration of 4...

  11. FY1995 contaminant study proposal : CO-nonpoint source pollution on the Rocky Mountain Arsenal National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Proposal to determine the extent of nonpoint source pollution to water bodies on the Rocky Mountain Arsenal National Wildlife Refuge (Arsenal). The Service will...

  12. Relationship Between Non-Point Source Pollution and Korean Green Factor

    OpenAIRE

    Seung Chul Lee; In-Hyeok Park; Byung Sik Kim; and Sung Ryong Ha

    2015-01-01

    In determining the relationship between the rational event mean concentration (REMC) which is a volume-weighted mean of event mean concentrations (EMCs) as a non-point source (NPS) pollution indicator and the green factor (GF) as a low impact development (LID) land use planning indicator, we constructed at runoff database containing 1483 rainfall events collected from 107 different experimental catchments from 19 references in Korea. The collected data showed that EMCs were not correlated wit...

  13. An interdisciplinary assessment of regional-scale nonpoint source ground-water vulnerability; theory and application

    Science.gov (United States)

    Bernknopf, Richard L.; Dinitz, Laura B.; Loague, Keith

    2001-01-01

    An integrated earth science-economics model, developed within a geographic information system (GIS), combines a regional-scale nonpoint source vulnerability assessment with a specific remediation measure to avoid unnecessary agricultural production costs associated with the use of agrochemicals in the Pearl Harbor basin on the island of Oahu, Hawaii. This approach forms the core of a risk-based regulation for the application of agrochemicals and estimates the benefits of an information-based approach to decisionmaking.

  14. THE METHOD OF CAR HEADLIGHTS LUMINOUS INTENSITY MEASURING FOR NON-POINT SOURCES OF LIGHT

    Directory of Open Access Journals (Sweden)

    A. Kupko

    2015-12-01

    Full Text Available It is shown that the measurements of luminous intensity of car headlights luminous intensity for non-point sources have pecularities. A simplified method for correction the luminous intensity at various distances is developed. The applicability of the given method with possible measurement errors is studied. The results were obtained, using a stand of the National Scientific Center “Institute of Metroligy”.

  15. Managing Nonpoint Source Pollution in Western Washington: Landowner Learning Methods and Motivations

    Science.gov (United States)

    Ryan, Clare M.

    2009-06-01

    States, territories, and tribes identify nonpoint source pollution as responsible for more than half of the Nation’s existing and threatened water quality impairments, making it the principal remaining cause of water quality problems across the United States. Combinations of education, technical and financial assistance, and regulatory measures are used to inform landowners about nonpoint source pollution issues, and to stimulate the use of best management practices. A mail survey of non-commercial riparian landowners investigated how they learn about best management practices, the efficacy of different educational techniques, and what motivates them to implement land management activities. Landowners experience a variety of educational techniques, and rank those that include direct personal contact as more effective than brochures, advertisements, radio, internet, or television. The most important motivations for implementing best management practices were linked with elements of a personal stewardship ethic, accountability, personal commitment, and feasibility. Nonpoint source education and social marketing campaigns should include direct interpersonal contacts, and appeal to landowner motivations of caring, responsibility, and personal commitment.

  16. Modeling nonpoint source nitrate contamination and associated uncertainty in groundwater of U.S. regional aquifers

    Science.gov (United States)

    Gurdak, J. J.; Lujan, C.

    2009-12-01

    Nonpoint source nitrate contamination in groundwater is spatially variable and can result in elevated nitrate concentrations that threaten drinking-water quality in many aquifers of the United States. Improved modeling approaches are needed to quantify the spatial controls on nonpoint source nitrate contamination and the associated uncertainty of predictive models. As part of the U.S. Geological Survey National Water Quality Assessment Program, logistic regression models were developed to predict nitrate concentrations greater than background in recently recharged (less than 50 years) groundwater in selected regional aquifer systems of the United States; including the Central Valley, California Coastal Basins, Basin and Range, Floridan, Glacial, Coastal Lowlands, Denver Basin, High Plains, North Atlantic Coastal Plain, and Piedmont aquifer systems. The models were used to evaluate the spatial controls of climate, soils, land use, hydrogeology, geochemistry, and water-quality conditions on nitrate contamination. The novel model Raster Error Propagation Tool (REPTool) was used to estimate error propagation and prediction uncertainty in the predictive nitrate models and to determine an approach to reduce uncertainty in future model development. REPTool consists of public-domain, Python-based packages that implement Latin Hypercube sampling within a probabilistic framework to track error propagation in geospatial models and quantitatively estimate the prediction uncertainty of the model output. The presented nitrate models, maps, and uncertainty analysis provide important tools for water-resource managers of regional groundwater systems to identify likely areas and the spatial controls on nonpoint source nitrate contamination in groundwater.

  17. Optimization Tool For Allocation Of Watershed Management Practices For Sediment And Nutrient Control

    Science.gov (United States)

    Implementation of conservation programs are perceived as being crucial for restoring and protecting waters and watersheds from nonpoint source pollution. Success of these programs depends to a great extent on planning tools that can assist the watershed management process. Herein...

  18. A method to analyze "source-sink" structure of non-point source pollution based on remote sensing technology.

    Science.gov (United States)

    Jiang, Mengzhen; Chen, Haiying; Chen, Qinghui

    2013-11-01

    With the purpose of providing scientific basis for environmental planning about non-point source pollution prevention and control, and improving the pollution regulating efficiency, this paper established the Grid Landscape Contrast Index based on Location-weighted Landscape Contrast Index according to the "source-sink" theory. The spatial distribution of non-point source pollution caused by Jiulongjiang Estuary could be worked out by utilizing high resolution remote sensing images. The results showed that, the area of "source" of nitrogen and phosphorus in Jiulongjiang Estuary was 534.42 km(2) in 2008, and the "sink" was 172.06 km(2). The "source" of non-point source pollution was distributed mainly over Xiamen island, most of Haicang, east of Jiaomei and river bank of Gangwei and Shima; and the "sink" was distributed over southwest of Xiamen island and west of Shima. Generally speaking, the intensity of "source" gets weaker along with the distance from the seas boundary increase, while "sink" gets stronger.

  19. Investigation and Analysis of Guangzhou Nansha Coast Park Point Source Pollution and Non-point Source Pollution

    Institute of Scientific and Technical Information of China (English)

    Ruijie; YANG; Huanghuang; ZENG; Budan; CHEN; Fang; CHEN; Shikai; WU

    2014-01-01

    [Objective]To find out the situation of Nansha Coast Park point and non-point source pollution.[Method]By investigating the park water environment,analysis of point and non-point source pollutants contribution rate,setting up water quality monitoring sites for basic data related indicators and then using national water quality standards to evaluate water quality.[Result]The Coast Park point source pollution mainly comes from the campus greeting fertilizer spraying.The COD of lakes and river outside the park and ammonia mean concentration belong to grade III.The total nitrogen of lake belongs to grade III.The total phosphorus belongs to grade IV.The total nitrogen of river is the worst.The total phosphorus is grade V.[Conclusion] The lake water quality is highly affected by the point and non-point source pollution,the quality of the river is worse than that of the lake in the park,and it needs powerful governance.

  20. Global Pollution of Surface Waters from Point and Nonpoint Sources of Nitrogen

    Directory of Open Access Journals (Sweden)

    G. van Drecht

    2001-01-01

    Full Text Available Global 0.5- by 0.5-degree resolution estimates are presented on the fate of nitrogen (N stemming from point and nonpoint sources, including plant uptake, denitrification, leaching from the rooting zone, rapid flow through shallow groundwater, and slow flow through deep groundwater to riverine systems. Historical N inputs are used to describe the N flows in groundwater. For nonpoint N sources (agricultural and natural ecosystems, calculations are based on local hydrology, climate, geology, soils, climate and land use combined with data for 1995 on crop production, N inputs from N fertilizers and animal manure, and estimates for ammonia emissions, biological N fixation, and N deposition. For point sources, our estimates are based on population densities and human N emissions, sanitation, and treatment. The results provide a first insight into the magnitude of the N losses from soil-plant systems and point sources in various parts of the world, and the fate of N during transport in atmosphere, groundwater, and surface water. The contribution to the river N load by anthropogenic N pollution is dominant in many river basins in Europe, Asia, and North Africa. Our model results explain much of the variation in measured N export from different world river basins.

  1. Integrating water quality modeling with ecological risk assessment for nonpoint source pollution control: A conceptual framework

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.D.; McCutcheon, S.C.; Rasmussen, T.C.; Nutter, W.L.; Carsel, R.F.

    1993-01-01

    The historical development of water quality protection goals and strategies in the United States is reviewed. The review leads to the identification and discussion of three components (i.e., management mechanism, environmental investigation approaches, and environmental assessment and criteria) for establishing a management framework for nonpoint source pollution control. Water quality modeling and ecological risk assessment are the two most important and promising approaches to the operation of the proposed management framework. A conceptual framework that shows the general integrative relationships between water quality modeling and ecological risk assessment is presented. (Copyright (c) 1993 IAWQ.)

  2. Response of non-point source pollutant loads to climate change in the Shitoukoumen reservoir catchment.

    Science.gov (United States)

    Zhang, Lei; Lu, Wenxi; An, Yonglei; Li, Di; Gong, Lei

    2012-01-01

    The impacts of climate change on streamflow and non-point source pollutant loads in the Shitoukoumen reservoir catchment are predicted by combining a general circulation model (HadCM3) with the Soil and Water Assessment Tool (SWAT) hydrological model. A statistical downscaling model was used to generate future local scenarios of meteorological variables such as temperature and precipitation. Then, the downscaled meteorological variables were used as input to the SWAT hydrological model calibrated and validated with observations, and the corresponding changes of future streamflow and non-point source pollutant loads in Shitoukoumen reservoir catchment were simulated and analyzed. Results show that daily temperature increases in three future periods (2010-2039, 2040-2069, and 2070-2099) relative to a baseline of 1961-1990, and the rate of increase is 0.63°C per decade. Annual precipitation also shows an apparent increase of 11 mm per decade. The calibration and validation results showed that the SWAT model was able to simulate well the streamflow and non-point source pollutant loads, with a coefficient of determination of 0.7 and a Nash-Sutcliffe efficiency of about 0.7 for both the calibration and validation periods. The future climate change has a significant impact on streamflow and non-point source pollutant loads. The annual streamflow shows a fluctuating upward trend from 2010 to 2099, with an increase rate of 1.1 m(3) s(-1) per decade, and a significant upward trend in summer, with an increase rate of 1.32 m(3) s(-1) per decade. The increase in summer contributes the most to the increase of annual load compared with other seasons. The annual NH (4) (+) -N load into Shitoukoumen reservoir shows a significant downward trend with a decrease rate of 40.6 t per decade. The annual TP load shows an insignificant increasing trend, and its change rate is 3.77 t per decade. The results of this analysis provide a scientific basis for effective support of decision

  3. Uncertainty Analysis of non-point source pollution control facilities design techniques in Korea

    Science.gov (United States)

    Lee, J.; Okjeong, L.; Gyeong, C. B.; Park, M. W.; Kim, S.

    2015-12-01

    The design of non-point sources control facilities in Korea is divided largely by the stormwater capture ratio, the stormwater load capture ratio, and the pollutant reduction efficiency of the facility. The stormwater capture ratio is given by a design formula as a function of the water quality treatment capacity, the greater the capacity, the more the amount of stormwater intercepted by the facility. The stormwater load capture ratio is defined as the ratio of the load entering the facility of the total pollutant load generated in the target catchment, and is given as a design formula represented by a function of the stormwater capture ratio. In order to estimate the stormwater capture ratio and load capture ratio, a lot of quantitative analysis of hydrologic processes acted in pollutant emission is required, but these formulas have been applied without any verification. Since systematic monitoring programs were insufficient, verification of these formulas was fundamentally impossible. However, recently the Korean ministry of Environment has conducted an long-term systematic monitoring project, and thus the verification of the formulas became possible. In this presentation, the stormwater capture ratio and load capture ratio are re-estimated using actual TP data obtained from long-term monitoring program at Noksan industrial complex located in Busan, Korea. Through the re-estimated process, the uncertainty included in the design process that has been applied until now will be shown in a quantitative extent. In addition, each uncertainty included in the stormwater capture ratio estimation and in the stormwater load capture ratio estimation will be expressed to quantify the relative impact on the overall non-point pollutant control facilities design process. Finally, the SWMM-Matlab interlocking module for model parameters estimation will be introduced. Acknowledgement This subject is supported by Korea Ministry of Environment as "The Eco Innovation Project : Non-point

  4. The removal of nutrients from non-point source wastewater by a hybrid bioreactor.

    Science.gov (United States)

    Wu, Yonghong; Hu, Zhengyi; Yang, Linzhang; Graham, Bruce; Kerr, Philip G

    2011-02-01

    The aim of this project was to establish an economical and environmentally benign biotechnology for removing nutrients from non-point source wastewater. The proposal involves a hybrid bioreactor comprised of sequential anaerobic, anoxic and aerobic (A(2)/O) processes and an eco-ditch being constructed and applied in a suburban area, Kunming, south-western China, where wastewater was discharged from an industrial park and suburban communities. The results show that the hybrid bioreactor fosters heterotrophic and autotrophic microorganisms. When the hydraulic load is 200 m(3) per day with the running mode in 12h cycles, the removal efficiencies of the nutrients were 81% for TP, 74% for TDP, 82% for TN, 79% for NO(3)-N and 86% for NH(4)-N. The improved bacterial community structure and bacterial habitats further implied enhanced water quality and indicates that the easily-deployed, affordable and environmentally-friendly hybrid bioreactor is a promising bio-measure for removing high loadings of nutrients from non-point source wastewater.

  5. Assessing the Hydrologic Performance of the EPA's Nonpoint Source Water Quality Assessment Decision Support Tool Using North American Land Data Assimilation System (Products)

    Science.gov (United States)

    Lee, S.; Ni-Meister, W.; Toll, D.; Nigro, J.; Guiterrez-Magness, A.; Engman, T.

    2010-01-01

    The accuracy of streamflow predictions in the EPA's BASINS (Better Assessment Science Integrating Point and Nonpoint Sources) decision support tool is affected by the sparse meteorological data contained in BASINS. The North American Land Data Assimilation System (NLDAS) data with high spatial and temporal resolutions provide an alternative to the NOAA National Climatic Data Center (NCDC)'s station data. This study assessed the improvement of streamflow prediction of the Hydrological Simulation Program-FORTRAN (HSPF) model contained within BASINS using the NLDAS 118 degree hourly precipitation and evapotranspiration estimates in seven watersheds of the Chesapeake Bay region. Our results demonstrated consistent improvements of daily streamflow predictions in five of the seven watersheds when NLDAS precipitation and evapotranspiration data was incorporated into BASINS. The improvement of using the NLDAS data is significant when watershed's meteorological station is either far away or not in a similar climatic region. When the station is nearby, using the NLDAS data produces similar results. The correlation coefficients of the analyses using the NLDAS data were greater than 0.8, the Nash-Sutcliffe (NS) model fit efficiency greater than 0.6, and the error in the water balance was less than 5%. Our analyses also showed that the streamflow improvements were mainly contributed by the NLDAS's precipitation data and that the improvement from using NLDAS's evapotranspiration data was not significant; partially due to the constraints of current BASINS-HSPF settings. However, NLDAS's evapotranspiration data did improve the baseflow prediction. This study demonstrates the NLDAS data has the potential to improve stream flow predictions, thus aid the water quality assessment in the EPA nonpoint water quality assessment decision tool.

  6. Export of non-point source suspended sediment, nitrogen, and phosphorus from sloping highland agricultural fields in the East Asian monsoon region.

    Science.gov (United States)

    Reza, Arif; Eum, Jaesung; Jung, Sungmin; Choi, Youngsoon; Owen, Jeffrey S; Kim, Bomchul

    2016-12-01

    Excess sediment and nutrient export from agricultural fields with steep slopes is a major concern linked to surface water quality in Korea. In this study, the export of suspended sediment (SS), total nitrogen (TN), and total phosphorus (TP) and their event mean concentrations (EMCs) in surface runoff from a highland mixed land use (61% forested, 30% cropped, 9% other) watershed were quantified. In 2007, the Korean Ministry of Environment (MoE) declared the study area as a priority region for non-point source (NPS) pollution management and initiated various best management practices (BMPs) in the study watershed. SS, TN, and TP concentrations in Mandae Stream were monitored for 5 years (2009-2013) to evaluate the effectiveness of BMPs. Average EMCs for SS, TN, and TP were as high as 986, 3.4 and 0.8 mg/L, respectively. The agricultural export coefficients of agricultural land in the study watershed for SS, TN, and TP were 5611, 171, and 6.83 kg/ha/year, respectively. A comparison with results from other studies shows that both EMCs and agricultural export coefficients in the study watershed were much higher than most of the results reported for watersheds in other regions. The results show that sediment and nutrient export from intensive agriculture areas with steep slopes continue to be a major concern for the downstream reservoir, Lake Soyang. Remedial strategies should be directed towards controlling sources of SS, TN, and TP to improve downstream water quality in sloping highland agricultural areas in Korea.

  7. Nanomaterials for environmental burden reduction, waste treatment, and nonpoint source pollution control: a review

    Institute of Scientific and Technical Information of China (English)

    Guobin SHAN; Rao Y. SURAMPALLI; Rajeshwar D. TYAGI; Tian C. ZHANG

    2009-01-01

    Nanomaterials are applicable in the areas of reduction of environmental burden, reduction/treatment of industrial and agricultural wastes, and nonpoint source (NPS) pollution control. First, environmental burden reduction involves green process and engineering, emis-sions control, desulfurization/denitrification of nonrenew-able energy sources, and improvement of agriculture and food systems. Second, reduction/treatment of industrial and agricultural wastes involves converting wastes into products, groundwater remediation, adsorption, delaying photocatalysis, and nanomembranes. Third, NPS pollution control involves controlling water pollution. Nanomater-ials alter physical properties on a nanoscale due to their high specific surface area to volume ratio. They are used as catalysts, adsorbents, membranes, and additives to increase activity and capability due to their high specific surface areas and nano-sized effects. Thus, nanomaterials are more effective at treating environmental wastes because they reduce the amount of material needed.

  8. Long-term vegetation landscape pattern with non-point source nutrient pollution in upper stream of Yellow River basin

    NARCIS (Netherlands)

    Ouyang, W.; Skidmore, A.K.; Toxopeus, A.G.; Hao, F.

    2010-01-01

    Grassland, forest, and farmland are the dominant land covers in upper catchments of the Yellow River and their landscape status has direct connection with dynamics of non-point source (NPS) pollution. Understanding the correlations between landscape variables and different formats of NPS nutrients p

  9. Long-term vegetation landscape pattern with non-point source nutrient pollution in upper stream of Yellow River basin

    NARCIS (Netherlands)

    Ouyang, W.; Skidmore, A.K.; Toxopeus, A.G.; Hao, F.

    2010-01-01

    Grassland, forest, and farmland are the dominant land covers in upper catchments of the Yellow River and their landscape status has direct connection with dynamics of non-point source (NPS) pollution. Understanding the correlations between landscape variables and different formats of NPS nutrients p

  10. Mitigation of nonpoint source pollution in rural areas: From control to synergies of multi ecosystem services.

    Science.gov (United States)

    Wu, Yonghong; Liu, Junzhuo; Shen, Renfang; Fu, Bojie

    2017-12-31

    Nonpoint source (NPS) pollution produced by human activities in rural areas has induced excessive nutrient input into surface waters and the decline of water quality. The essence of NPS pollution is the transport of nutrients between soil and water. Traditional NPS pollution control strategies, however, are mainly based on the solid and liquid phases, with little focus on the bio-phase between water and soil. The pollutants produced from NPS can be regarded as a resource if recycled or reused in an appropriate way in the agricultural ecosystem. This mini review proposes novel strategies for NPS pollution control based on three phases (liquid, solid and bio-phase) and highlights the regulating services of an agricultural ecosystem by optimizing land use/cover types. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. [Zoning planning in non-point source pollution control in Hanyang district].

    Science.gov (United States)

    Yang, Liu; Ma, Ke-Ming; Guo, Qing-Hai; Zhao, Jing-Zhu; Luo, Yong-Feng

    2006-01-01

    It is most important for managing urban non-point source (NPS) pollution, actualizing the urban sustainable development as well, that zoning planning of urban NPS pollution control is studied. A case study on principles and methods of zoning planning in urban NPS pollution is carried out. Principles of urban sustainable development, priority of urban NPS pollution sensitivity, similarity of urban NPS control direction and region conjugate are put forward. Besides, it is for the first time that a more quantitive method is presented, in the case of Hanyang district, Wuhan city, which is based on L-THIA model and spatial analysis technique in GIS. Assessment of NPS pollution status quo, as well as analysis of NPS sensitivity, is the kernel component of the quantitive method. Hanyang might be divided into four NPS pollution control zones. It is helpful for decision-making of regional NPS pollution control.

  12. Isotopic Tracers for Delineating Non-Point Source Pollutants in Surface Water

    Energy Technology Data Exchange (ETDEWEB)

    Davisson, M L

    2001-03-01

    This study tested whether isotope measurements of surface water and dissolved constituents in surface water could be used as tracers of non-point source pollution. Oxygen-18 was used as a water tracer, while carbon-14, carbon-13, and deuterium were tested as tracers of DOC. Carbon-14 and carbon-13 were also used as tracers of dissolved inorganic carbon, and chlorine-36 and uranium isotopes were tested as tracers of other dissolved salts. In addition, large databases of water quality measurements were assembled for the Missouri River at St. Louis and the Sacramento-San Joaquin Delta in California to enhance interpretive results of the isotope measurements. Much of the water quality data has been under-interpreted and provides a valuable resource to investigative research, for which this report exploits and integrates with the isotope measurements.

  13. Walnut Creek Watershed Restoration and Water Quality Monitoring Project

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The primary objective of this project is to establish a nonpoint source monitoring program in relation to the watershed habitat restoration and agricultural...

  14. [Spatial discharge characteristics and total load control of non-point source pollutants based on the catchment scale].

    Science.gov (United States)

    Wang, Xia-Hui; Lu, Jun; Zhang, Qing-Zhong; Wang, Bo; Yao, Rui-Hua; Zhang, Hui-Yuan; Huang, Feng

    2011-09-01

    Agricultural non-point source pollution is one of the major causes of water quality deterioration. Based on the analysis of the spatial discharge characteristics and intensity of major pollutants from the agricultural pollution source, the establishment of spatial management subzones for controlling agricultural non-point pollution and a design of a plan for total load control of pollutants from each subzone is an important way to improve the efficiency of control measures. In this paper the Four Lake basin in Hubei Province is adopted as the research case region and a systematic research of the control countermeasures of agricultural non-point pollution based on the catchment scale is carried out. The results shows that in the Four Lake basin, the COD, total nitrogen, total phosphorus and ammonia nitrogen load of the water environment are mainly caused by agricultural non-point pollution. These four kinds of non-point source pollutants respectively account for 67.6%, 82.2%, 84.7% and 50.9% of the total pollutant discharge amount in the basin. The analysis of the spatial discharge characteristics of non-point source pollutants in the Four Lake basin shows that the major contributor source regions of non-point source pollutant in the basin are the four counties, including Honghu, Jianli, Qianjiang and Shayang where the aquatic and livestock production are relatively developed. According to the spatial discharge characteristics of the pollutants and the evaluation of the discharge intensity of pollutants, the Four Lake basin is divided into three agricultural non-point pollution management subzones, which including Changhu upstream aquatic and livestock production pollution control subzone, Four-lake trunk canal rural non-point source pollution control subzone and Honghu aquatic production pollution control subzone. Specific pollution control measures are put forward for each subzone. With a comprehensive consideration of the water quality amelioration and the

  15. Study on the Control Model of Rural Non-point Source Pollution——Taking Ninghe County in Tianjin as an Example

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the control model of rural non-point source pollution.[Method] Taking Ninghe County(a typical agricultural county in Tianjin) as an example,the current development of local economy and society and characteristics of rural non-point source pollution were studied firstly,then the control model of rural non-point source pollution suitable for Ninghe County was constructed,and its environmental and economic benefits were analyzed finally.[Result] According to the sources of non-...

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

    Science.gov (United States)

    Grazhdani, Dorina

    2015-07-01

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

  17. A case study on non-point source pollution and environmental carrying capacity of animal raising industry in subtropical watershed%亚热带流域氮磷排放与养殖业环境承载力实例研究

    Institute of Scientific and Technical Information of China (English)

    孟岑; 李裕元; 许晓光; 高茹; 王毅; 张满意; 吴金水

    2013-01-01

    畜禽养殖业粪便排放已经成为我国农村地区主要的农业面源污染源之一,也是制约养殖业良性发展的主要瓶颈.本文以湖南省长沙县典型亚热带流域为研究单元,基于流域水环境定位观测、耕地氮(N)磷(P)消纳能力以及养殖业调查和土壤分析资料,初步分析了亚热带丘陵区的面源污染现状及畜禽养殖业的环境承载力.结果表明,研究区金井河流域134.4 km2范围内N、P年负荷分别为N 2.72 t·km-2和P0.11t·km-2,其中养殖粪便对水体总氮(TN)、总磷(TP)负荷的贡献率分别约为42.2%和62.0%.区内平均畜禽养殖密度为3.46 AU·hm-2(相当于流域内年出栏生猪24.39万头),显著高于现有化肥用量条件下流域的实际承载力1.13 AU·hm-2(相当于流域内年出栏生猪6.35万头),因此养殖密度过高是导致研究区水体NP负荷较高的主要原因.区内N、P盈余量分别为N 35.8 kg·hm-2、P 18.61 kg·hm-2.研究区基本不施用化肥条件下畜禽养殖业的最大环境承载力为7.26 AU·hm-2,在有机肥占合理施肥量30%条件下,当地畜禽养殖业的环境承载力为2.74AU·hm-2(相当于流域内年出栏生猪19.50万头).降低养殖密度、调整养殖业空间布局以及提高养殖废弃物的资源化利用率是防治当前面源污染的有效途径.%The discharge of faeces from animal production is a major source of nitrogen ( N) and phosphorus (P) pollutants in the subtropical region of China. To quantify the N and F load from animal production to hydro-systems in the region, surveys on pig density and N,P inputs to farmlands, soil N and P contents, and annual observations of the N and P flows in the streams and the terminal river were carried out in a hilly watershed (134.4 km2 ) in Changsha County, Hunan Province. It was showed that the total NP loads from the watershed to the terminal river was 2.72 t and 0. 11 t·km-2·a-1, respectively ; within which 42. 2% of the N and 62. 0% of

  18. Effects of nonpoint and selected point contaminant sources on stream-water quality and relation to land use in Johnson County, northeastern Kansas, October 2002 through June 2004

    Science.gov (United States)

    Lee, Casey J.; Mau, D.P.; Rasmussen, T.J.

    2005-01-01

    Water and sediment samples were collected by the U.S. Geological Survey in 12 watersheds in Johnson County, northeastern Kansas, to determine the effects of nonpoint and selected point contaminant sources on stream-water quality and their relation to varying land use. The streams studied were located in urban areas of the county (Brush, Dykes Branch, Indian, Tomahawk, and Turkey Creeks), developing areas of the county (Blue River and Mill Creek), and in more rural areas of the county (Big Bull, Captain, Cedar, Kill, and Little Bull Creeks). Two base-flow synoptic surveys (73 total samples) were conducted in 11 watersheds, a minimum of three stormflow samples were collected in each of six watersheds, and 15 streambed-sediment sites were sampled in nine watersheds from October 2002 through June 2004. Discharge from seven wastewater treatment facilities (WWTFs) were sampled during base-flow synoptic surveys. Discharge from these facilities comprised greater than 50 percent of streamflow at the farthest downstream sampling site in six of the seven watersheds during base-flow conditions. Nutrients, organic wastewater-indicator compounds, and prescription and nonprescription pharmaceutical compounds generally were found in the largest concentrations during base-flow conditions at sites at, or immediately downstream from, point-source discharges from WWTFs. Downstream from WWTF discharges streamflow conditions were generally stable, whereas nutrient and wastewater-indicator compound concentrations decreased in samples from sites farther downstream. During base-flow conditions, sites upstream from WWTF discharges had significantly larger fecal coliform and Escherichia coli densities than downstream sites. Stormflow samples had the largest suspended-sediment concentrations and indicator bacteria densities. Other than in samples from sites in proximity to WWTF discharges, stormflow samples generally had the largest nutrient concentrations in Johnson County streams. Discharge

  19. Mapping the scientific research on non-point source pollution: a bibliometric analysis.

    Science.gov (United States)

    Yang, Beibei; Huang, Kai; Sun, Dezhi; Zhang, Yue

    2017-02-01

    A bibliometric analysis was conducted to examine the progress and future research trends of non-point source (NPS) pollution during the years 1991-2015 based on the Science Citation Index Expanded (SCI-Expanded) of Web of Science (WoS). The publications referencing NPS pollution were analyzed including the following aspects: document type, publication language, publication output and characteristics, subject category, source journal, distribution of country and institution, author keywords, etc. The results indicate that the study of NPS pollution demonstrated a sharply increasing trend since 1991. Article and English were the most commonly used document type and language. Environmental sciences and ecology, water resources, and engineering were the top three subject categories. Water science and technology ranked first in distribution of journal, followed by Science of the total environment and Environmental Monitoring and Assessment. The USA took a leading position in both quantity and quality, playing an important role in the research field of NPS pollution, followed by the UK and China. The most productive institution was the Chinese Academy of Sciences (Chinese Acad Sci), followed by Beijing Normal University and US Department of Agriculture's Agricultural Research Service (USDA ARS). The analysis of author keywords indicates that the major hotspots of NPS pollution from 1991 to 2015 contained "water," "model," "agriculture," "nitrogen," "phosphorus," etc. The results provide a comprehensive understanding of NPS pollution research and help readers to establish the future research directions.

  20. Denitrification controls in urban riparian soils: implications for reducing urban nonpoint source nitrogen pollution.

    Science.gov (United States)

    Li, Yangjie; Chen, Zhenlou; Lou, Huanjie; Wang, Dongqi; Deng, Huanguang; Wang, Chu

    2014-09-01

    The purpose of this research was to thoroughly analyze the influences of environmental factors on denitrification processes in urban riparian soils. Besides, the study was also carried out to identify whether the denitrification processes in urban riparian soils could control nonpoint source nitrogen pollution in urban areas. The denitrification rates (DR) over 1 year were measured using an acetylene inhibition technique during the incubation of intact soil cores from six urban riparian sites, which could be divided into three types according to their vegetation. The soil samples were analyzed to determine the soil organic carbon (SOC), soil total nitrogen (STN), C/N ratio, extractable NO3 (-)-N and NH4 (+)-N, pH value, soil water content (SWC), and the soil nitrification potential to evaluate which of these factors determined the final outcome of denitrification. A nitrate amendment experiment further indicated that the riparian DR was responsive to added nitrate. Although the DRs were very low (0.099 ~ 33.23 ng N2O-N g(-1) h(-1)) due to the small amount of nitrogen moving into the urban riparian zone, the spatial and temporal patterns of denitrification differed significantly. The extractable NO3 (-)-N proved to be the dominant factor influencing the spatial distribution of denitrification, whereas the soil temperature was a determinant of the seasonal DR variation. The six riparian sites could also be divided into two types (a nitrate-abundant and a nitrate-stressed riparian system) according to the soil NO3 (-)-N concentration. The DR in nitrate-abundant riparian systems was significantly higher than that in the nitrate-stressed riparian systems. The DR in riparian zones that were covered with bushes and had adjacent cropland was higher than in grass-covered riparian sites. Furthermore, the riparian DR decreased with soil depth, which was mainly attributed to the concentrated nitrate in surface soils. The DR was not associated with the SOC, STN, C/N ratio, and

  1. Spatial Regression and Prediction of Water Quality in a Watershed with Complex Pollution Sources.

    Science.gov (United States)

    Yang, Xiaoying; Liu, Qun; Luo, Xingzhang; Zheng, Zheng

    2017-08-16

    Fast economic development, burgeoning population growth, and rapid urbanization have led to complex pollution sources contributing to water quality deterioration simultaneously in many developing countries including China. This paper explored the use of spatial regression to evaluate the impacts of watershed characteristics on ambient total nitrogen (TN) concentration in a heavily polluted watershed and make predictions across the region. Regression results have confirmed the substantial impact on TN concentration by a variety of point and non-point pollution sources. In addition, spatial regression has yielded better performance than ordinary regression in predicting TN concentrations. Due to its best performance in cross-validation, the river distance based spatial regression model was used to predict TN concentrations across the watershed. The prediction results have revealed a distinct pattern in the spatial distribution of TN concentrations and identified three critical sub-regions in priority for reducing TN loads. Our study results have indicated that spatial regression could potentially serve as an effective tool to facilitate water pollution control in watersheds under diverse physical and socio-economical conditions.

  2. Search for the northwest passage: the assignation of NSP (non-point source pollution) rights in nutrient trading programs.

    Science.gov (United States)

    Collentine, D

    2002-01-01

    The search for solutions to the problem of non-point source pollution (NSP) includes alternatives based on theories associated with the use of tradable pollution permits. Tradable permit programs have received significant support as a promising policy for the reduction of effluent discharges but programs in practice have not been regarded as successful. The lack of success is ascribed to the design of the programs. However, this may be a design problem which is insurmountable due to the nature of the NSP problem. Tradable permit solutions are based on an assumption that the assignation of quantifiable rights to both point and nonpoint sources, based on some predetermined ambient water quality measure, is possible. The conclusion here is that there are significant features particular to NSP that hinder the introduction of rights and significantly decrease the utility of tradable permit solutions.

  3. The non-point source (NPS) information system based on remote sensing and GIS and its preliminary application

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A non-point source information system (NPSIS) has been constructed by use of remote sensing and GIS technology, and a construction method of NPSlS introduced with Shenzhen as an example. With the remote sensing land-using images as an environment unit, the analysis modules based on NPSIS are built through combining the NPS model with NPSIS, and the preliminary NPS calculation and analysis performed.

  4. Multi-Scale Monitoring and Assessment of Nonpoint Source Pollution in Groundwater

    Science.gov (United States)

    Harter, T.; Vanderschans, M.; Leijnse, A.; Mathews, M. C.; Meyer, R. D.

    2003-04-01

    The California dairy industry produces 20% of US milk and is the largest animal industry in the state. Many of the dairy facilities are located in low-relief valleys and basins with vulnerable groundwater resources. The continued influx of dairies into California's Central Valley has raised critical questions regarding their environmental performance, in particular with respect to groundwater quality impacts. While animal farming systems are considered among the leading sources of groundwater nitrate,little is known about the actual impact of dairy farming practices on groundwater quality in the extensive alluvial aquifers underlying the Central Valley. With our work we attempt to characterize and assess shallow groundwater underneath dairies in a relatively vulnerable hydrogeologic region and to discern the impact from various individual sources and management practices within dairies. An extensive shallow groundwater monitoring network was installed on five representative dairy operations in the northeastern San Joaquin Valley, California. The monitoring network spans all dairy management units: manure water lagoons, corrals, storage areas, and manure treated forage fields under various management practices. We recently also surveyed production well water quality. Water quality is found to be highly variable, both in time and space. We propose that a meaningful interpretation of these (nonpoint source pollution) data is only possible by explicitly considering the various scales affiliated with groundwater measurement, pollution source management, regulatory control, and beneficial use. Using statistical analysis and innovative modeling tools, we provide an interpretation of the observed data that is meaningful at the field scale (the scale unit of management decisions), the farm scale (considered to be a regulatory and planning unit), and the regional scale (considered to be a planning unit).

  5. Got Milk? Got Water? Innovative Approach to Evaluating Groundwater Nitrate Nonpoint Source Pollution from Animal Farming

    Science.gov (United States)

    Harter, T.; Vanderschans, M.; Leijnse, A.; Meyer, R. D.; Mathews, M. C.

    2002-12-01

    The California dairy industry produces 20% of US milk and is the largest animal industry in the state. Many of the dairy facilities are located in low-relief valleys and basins with vulnerable groundwater resources. The continued influx of dairies into California's Central Valley has raised critical questions regarding their environmental performance, in particular with respect to groundwater quality impacts. While animal farming systems are considered among the leading sources of groundwater nitrate,little is known about the actual impact of dairy farming practices on groundwater quality in the extensive alluvial aquifers underlying the Central Valley. With our work we attempt to characterize and assess shallow groundwater underneath dairies in a relatively vulnerable hydrogeologic region and to discern the impact from various individual sources and management practices within dairies. An extensive shallow groundwater monitoring network was installed on five representative dairy operations in the northeastern San Joaquin Valley, California. The monitoring network spans all dairy management units: manure water lagoons, corrals, storage areas, and manure treated forage fields under various management practices. We recently also surveyed production well water quality. Water quality is found to be highly variable, both in time and space. We propose that a meaningful interpretation of these (nonpoint source pollution) data is only possible by explicitly considering the various scales affiliated with groundwater measurement, pollution source management, regulatory control, and beneficial use. Using statistical analysis and innovative modeling tools, we provide an interpretation of the observed data that is meaningful at the field scale (the scale unit of management decisions), the farm scale (considered to be a regulatory and planning unit), and the regional scale (considered to be a planning unit).

  6. Event-based nonpoint source pollution prediction in a scarce data catchment

    Science.gov (United States)

    Chen, Lei; Sun, Cheng; Wang, Guobo; Xie, Hui; Shen, Zhenyao

    2017-09-01

    Quantifying the rainfall-runoff-pollutant (R-R-P) process is key to regulating non-point source (NPS) pollution; however, the impacts of scarce measured data on R-R-P simulations have not yet been reported. In this study, we conducted a comprehensive study of scarce data that addressed both rainfall-runoff and runoff-pollutant processes, whereby the impacts of data scarcity on two commonly used methods, including Unit Hydrograph (UH) and Loads Estimator (LOADEST), were quantified. A case study was performed in a typical small catchment of the Three Gorges Reservoir Region (TGRR) of China. Based on our results, the classification of rainfall patterns should be carried out first when analyzing modeling results. Compared to data based on a missing rate and a missing location, key information generates more impacts on the simulated flow and NPS loads. When the scarcity rate exceeds a certain threshold (20% in this study), measured data scarcity level has clear impacts on the model's accuracy. As the model of total nitrogen (TN) always performs better under different data scarcity conditions, researchers are encouraged to pay more attention to continuous the monitoring of total phosphorus (TP) for better NPS-TP predictions. The results of this study serve as baseline information for hydrologic forecasting and for the further control of NPS pollutants.

  7. Regional-scale assessment of non-point source groundwater contamination

    Science.gov (United States)

    Loague, Keith; Corwin, Dennis L.

    1998-05-01

    Predictive assessments of non-point source (NPS) pollution can have great utility for environmentally focused land use decisions related to both the remediation of existing groundwater contamination and the regulation of current (and future) agrochemical use. At the regional scales associated with NPS agrochemical applications there are staggering data management problems in assessing potential groundwater vulnerability. Geographical information system (GIS) technology is a timely tool that greatly facilitates the organized characterization of regional-scale variability. In this paper we review the recently reported (Loague et al., 1998a,b) simulations of NPS groundwater vulnerability, resulting from historical applications of the agrochemical DBCP (1,2-dibromo-3-chloropropane), for east-central Fresno County (California). The Fresno case study helps to illustrate the data requirements associated with process-based three-dimensional simulations of coupled fluid flow and solute transport in the unsaturated/saturated subsurface at a regional scale. The strengths and weaknesses of using GIS in regional-scale vulnerability assessments, such as the Fresno case study, and the critical problem of estimating the uncertainties in these assessments (owing to both data and model errors) are discussed. A regional GIS-driven integrated assessment approach is proposed, which is based upon cost-benefit analysis, and incorporates both physical and economic factors that can be used in a regulatory decision process.

  8. Application of a constructed wetland for non-point source pollution control.

    Science.gov (United States)

    Kao, C M; Wang, J Y; Lee, H Y; Wen, C K

    2001-01-01

    In Taiwan, non-point source (NPS) pollution is one of the major causes of impairment of surface waters. The main objective of this study was to evaluate the efficacy of using constructed wetlands on NPS pollutant removal and water quality improvements. A field-scale constructed wetland system was built inside the campus of National Sun Yat-Sen University (located in southern Taiwan) to remove (1) NPS pollutants due to the stormwater runoff, and (2) part of the untreated wastewater from school drains. The constructed wetland was 40 m (L) x 30 m (W) x 1 m (D), which received approximately 85 m3 per day of untreated wastewater from school drainage pipes. The plants grown on the wetland included floating (Pistia stratiotes L.) and emergent (Phragmites communis L.) species. One major storm event and baseline water quality samples were analyzed during the monitoring period. Analytical results indicate that the constructed wetland removed a significant amount of NPS pollutants and wastewater constituents. More than 88% of nitrogen, 81% of chemical oxygen demand (COD), 85% of heavy metals, and 60% of the total suspended solids (TSS) caused by the storm runoff were removed by the wetland system before discharging. Results from this study may be applied to the design of constructed wetlands for NPS pollution control and water quality improvement.

  9. Landscape Based Modeling of Nonpoint Source Nitrogen Loading in the Neuse River Basin, North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Garten, C.T.

    2001-01-11

    The objective of this research was to arrive at a quantitative and qualitative assessment of nonpoint sources of potential excess N under different land use/land cover (LULC) categories in the Neuse River Basin on a seasonal time scale. This assessment is being supplied to EPA's Landscape Characterization Branch, National Exposure Research Laboratory, in Research Triangle Park, NC, for inclusion in a hydrologic model to predict seasonal fluxes of N from the terrestrial landscape to surface receiving waters and groundwater in the Neuse River Basin. The analysis was performed in the following five steps: (1) development of a conceptual model to predict potential excess N on land, (2) a literature review to parameterize N fluxes under LULC categories found in the Neuse River Basin, (3) acquisition of high resolution (15-m pixel) LULC data from EPA's Landscape Characterization Branch, National Exposure Research Laboratory, in Research Triangle Park, NC, (4) acquisition of a soil N inventory map for the Neuse River Basin, (5) calculations of potential excess N on a seasonal basis for the entire Neuse River Basin.

  10. Pollution of surface waters by metalaxyl and nitrate from non-point sources.

    Science.gov (United States)

    Bermúdez-Couso, Alipio; Fernández-Calviño, David; Álvarez-Enjo, Manuel Ali; Simal-Gándara, Jesús; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel

    2013-09-01

    The mobility of contaminants in soil is highly dependent upon the characteristics of the contaminant chemical and the properties of the soil. In order to explore these relationships, the district of A Limia (Galicia, NW Spain) was selected as the study area--a cropland devoted to growing potatoes, where the soil had been managed intensively over the last 50 years. The soil was characterised by low slopes with the water table located very close to the soil surface. Our aim was to study the influence of high and intensive crop production on the water bodies and non-point source contamination, with a particular focus on metalaxyl and nitrate. The highest concentrations of metalaxyl occurred when rainfalls were low and in zones of the study area where natural hydrology was significantly altered by numerous drainage canals. The spatial and temporal distributions of the nitrate also showed a high variability, with the interaction between seasons and sampling area being the most significant factor in explaining the levels found. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Introduction: Assessing non-point source pollution in the vadose zone with advanced information technologies

    Science.gov (United States)

    Corwin, Dennis L.; Loague, Keith; Ellsworth, Timothy R.

    The information age has ushered in a global awareness of complex environmental problems that do not respect political or physical boundaries: climatic change, ozone layer depletion, deforestation, desertification, and non-point source (NPS) pollution. Among these global environmental problems, NPS pollutants represent a perfect example of a complex multidisciplinary problem that exists over multiple scales with tremendous spatial and temporal complexity. To address the NPS problem, specific to the vadose zone, advanced information technologies must be applied in a spatial context. An integrated system of advanced information technologies (i.e., global positioning, geographic information system, geostatistics, remote sensing, solute transport modeling, neural networks, transfer functions, fuzzy logic, hierarchical theory, and uncertainty analysis) provides a framework from which real-time and/or simulated assessments of NPS pollution can be made. The ability to accurately assess present and future NPS-pollution impacts on ecosystems ranging from local to global scales provides a powerful tool for environmental stewardship and guiding future human activities.

  12. Development of type transfer functions for regional-scale nonpoint source groundwater vulnerability assessments

    Science.gov (United States)

    Stewart, Iris T.; Loague, Keith

    2003-12-01

    Groundwater vulnerability assessments of nonpoint source agrochemical contamination at regional scales are either qualitative in nature or require prohibitively costly computational efforts. By contrast, the type transfer function (TTF) modeling approach for vadose zone pesticide leaching presented here estimates solute concentrations at a depth of interest, only uses available soil survey, climatic, and irrigation information, and requires minimal computational cost for application. TTFs are soil texture based travel time probability density functions that describe a characteristic leaching behavior for soil profiles with similar soil hydraulic properties. Seven sets of TTFs, representing different levels of upscaling, were developed for six loam soil textural classes with the aid of simulated breakthrough curves from synthetic data sets. For each TTF set, TTFs were determined from a group or subgroup of breakthrough curves for each soil texture by identifying the effective parameters of the function that described the average leaching behavior of the group. The grouping of the breakthrough curves was based on the TTF index, a measure of the magnitude of the peak concentration, the peak arrival time, and the concentration spread. Comparison to process-based simulations show that the TTFs perform well with respect to mass balance, concentration magnitude, and the timing of concentration peaks. Sets of TTFs based on individual soil textures perform better for all the evaluation criteria than sets that span all textures. As prediction accuracy and computational cost increase with the number of TTFs in a set, the selection of a TTF set is determined by a given application.

  13. A distributed non-point source pollution model: calibration and validation in the Yellow River Basin.

    Science.gov (United States)

    Hao, Fang-hua; Zhang, Xue-song; Yang, Zhi-feng

    2004-01-01

    The applicability of a non-point source pollution model--SWAT(soil and water assessment tools) in a large river basin with high sediment runoff modulus(770 t/km2 in the Yellow River) was examined. The basic database, which includes DEM, soil and landuse map, weather data, and land management data, was established for the study area using GIS. A two-stage "Brute Force" optimization method was used to calibrate the parameters with the observed monthly flow and sediment data from 1992 to 1997. In the process of calibration automated digital filter technique was used to separate direct runoff and base flow. The direct runoff was firstly calibrated, and the base flow, then the total runoff was matched. The sediment yield was calibrated to match well. Keeping input parameters set during the calibration process unchanged, the model was validated with 1998--1999's observed monthly flow and sediment. The evaluation coefficients for simulated and observed flow and sediment showed that SWAT was successfully applied in the study area: relative error was within 20%, coefficient of determination and Nash-Suttcliffe simulation efficiency were all equal to or above 0.70 during calibration and validation period.

  14. Model AVSWAT apropos of simulating non-point source pollution in Taihu lake basin.

    Science.gov (United States)

    Zhang, Qiu-Ling; Chen, Ying-Xu; Jilani, Ghulam; Shamsi, Imran Haider; Yu, Qiao-Gang

    2010-02-15

    Accelerated eutrophication and nutrient loads in the lakes are of major concern for human health and environment. This study was undertaken for modeling the non-point source pollution of Taihu lake basin in eastern China. The SWAT model having an interface in ArcView GIS was employed. Model sensitive parameters related to hydrology and water quality were obtained by sensitivity analysis, and then calibrated and validated by comparing model predictions with field data. The GIS showed good potential for parameterization of hill-slopes, channels, and representative slope profiles for SWAT model simulations. In a monthly and daily time step, the model's Nash-Sutcliffe coefficient (E) and the coefficient of determination (R(2)) indicated that values of simulated runoff, NH(4)(+)-N and total phosphorus were acceptably closer to the measured data. Surface water parameters especially CN, Soil-AWC and ESCO were the most sensitive and had more recognition in the model. It is concluded that runoff carrying N and P nutrients from chemical fertilizer inputs in agricultural areas is the major contributor to NPSP in the lake basin. So, decrease in excessive use of N and P fertilizers and their synergism with organic manures is recommended that would significantly reduce nutrient pollution in the lake ecosystem.

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

    Science.gov (United States)

    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

  16. Agricultural non-point source pollution of glyphosate and AMPA at a catchment scale

    Science.gov (United States)

    Okada, Elena; Perez, Debora; De Geronimo, Eduardo; Aparicio, Virginia; Costa, Jose Luis

    2017-04-01

    Information on the actual input of pesticides into the environment is crucial for proper risk assessment and the design of risk reduction measures. The Crespo basin is found within the Balcarce County, located south-east of the Buenos Aires Province. The whole basin has an area of approximately 490 km2 and the river has a length of 65 km. This study focuses on the upper basin of the Crespo stream, covering an area of 226 km2 in which 94.7% of the land is under agricultural production representing a highly productive area, characteristic of the Austral Pampas region. In this study we evaluated the levels of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) in soils; and the non-point source pollution of surface waters, stream sediments and groundwater, over a period of one year. Stream water samples were taken monthly using propylene bottles, from the center of the bridge. If present, sediment samples from the first 5 cm were collected using cylinder samplers. Groundwater samples were taken from windmills or electric pumps from different farms every two months. At the same time, composite soil samples (at 5 cm depth) were taken from an agricultural plot of each farm. Samples were analyzed for detection and quantification of glyphosate and AMPA using ultra-performance liquid chromatography coupled to a mass spectrometer (UPLC-MS/MS). The limit of detection (LD) in the soil samples was 0.5 μg Kg-1 and the limit of quantification (LQ) was 3 μg Kg-1, both for glyphosate and AMPA. In water samples the LD was 0.1 μg L-1 and the LQ was 0.5 μg L-1. The results showed that the herbicide dispersed into all the studied environmental compartments. Glyphosate and AMPA residues were detected in 34 and 54% of the stream water samples, respectively. Sediment samples had a higher detection frequency (>96%) than water samples, and there was no relationship between the presence in surface water with the detection in sediment samples. The presence in sediment samples

  17. A Framework to Assess the Impacts of Climate Change on Stream Health Indicators in Michigan Watersheds

    Science.gov (United States)

    Climate change is projected to alter watershed hydrology and potentially amplify nonpoint source pollution transport. These changes have implications for fish and macroinvertebrates, which are often used as measures of aquatic ecosystem health. By quantifying the risk of adverse ...

  18. Impacts of DEM uncertainties on critical source areas identification for non-point source pollution control based on SWAT model

    Science.gov (United States)

    Xu, Fei; Dong, Guangxia; Wang, Qingrui; Liu, Lumeng; Yu, Wenwen; Men, Cong; Liu, Ruimin

    2016-09-01

    The impacts of different digital elevation model (DEM) resolutions, sources and resampling techniques on nutrient simulations using the Soil and Water Assessment Tool (SWAT) model have not been well studied. The objective of this study was to evaluate the sensitivities of DEM resolutions (from 30 m to 1000 m), sources (ASTER GDEM2, SRTM and Topo-DEM) and resampling techniques (nearest neighbor, bilinear interpolation, cubic convolution and majority) to identification of non-point source (NPS) critical source area (CSA) based on nutrient loads using the SWAT model. The Xiangxi River, one of the main tributaries of Three Gorges Reservoir in China, was selected as the study area. The following findings were obtained: (1) Elevation and slope extracted from the DEMs were more sensitive to DEM resolution changes. Compared with the results of the 30 m DEM, 1000 m DEM underestimated the elevation and slope by 104 m and 41.57°, respectively; (2) The numbers of subwatersheds and hydrologic response units (HRUs) were considerably influenced by DEM resolutions, but the total nitrogen (TN) and total phosphorus (TP) loads of each subwatershed showed higher correlations with different DEM sources; (3) DEM resolutions and sources had larger effects on CSAs identifications, while TN and TP CSAs showed different response to DEM uncertainties. TN CSAs were more sensitive to resolution changes, exhibiting six distribution patterns at all DEM resolutions. TP CSAs were sensitive to source and resampling technique changes, exhibiting three distribution patterns for DEM sources and two distribution patterns for DEM resampling techniques. DEM resolutions and sources are the two most sensitive SWAT model DEM parameters that must be considered when nutrient CSAs are identified.

  19. Relationship Between Non-Point Source Pollution and Korean Green Factor

    Directory of Open Access Journals (Sweden)

    Seung Chul Lee

    2015-01-01

    Full Text Available In determining the relationship between the rational event mean concentration (REMC which is a volume-weighted mean of event mean concentrations (EMCs as a non-point source (NPS pollution indicator and the green factor (GF as a low impact development (LID land use planning indicator, we constructed at runoff database containing 1483 rainfall events collected from 107 different experimental catchments from 19 references in Korea. The collected data showed that EMCs were not correlated with storm factors whereas they showed significant differences according to the land use types. The calculated REMCs for BOD, COD, TSS, TN, and TP showed negative correlations with the GFs. However, even though the GFs of the agricultural area were concentrated in values of 80 like the green areas, the REMCs for TSS, TN, and TP were especially high. There were few differences in REMC runoff characteristics according to the GFs such as recreational facilities areas in suburbs and highways and trunk roads that connect to major roads between major cities. Except for those areas, the REMCs for BOD and COD were significantly related to the GFs. The REMCs for BOD and COD decreased when the rate of natural green area increased. On the other hand, some of the REMCs for TSS, TN, and TP were still high where the catchments encountered mixed land use patterns, especially public facility areas with bare ground and artificial grassland areas. The GF could therefore be used as a major planning indicator when establishing land use planning aimed at sustainable development with NPS management in urban areas if the weighted GF values will be improved.

  20. The Treatment Train approach to reducing non-point source pollution from agriculture

    Science.gov (United States)

    Barber, N.; Reaney, S. M.; Barker, P. A.; Benskin, C.; Burke, S.; Cleasby, W.; Haygarth, P.; Jonczyk, J. C.; Owen, G. J.; Snell, M. A.; Surridge, B.; Quinn, P. F.

    2016-12-01

    An experimental approach has been applied to an agricultural catchment in NW England, where non-point pollution adversely affects freshwater ecology. The aim of the work (as part of the River Eden Demonstration Test Catchment project) is to develop techniques to manage agricultural runoff whilst maintaining food production. The approach used is the Treatment Train (TT), which applies multiple connected mitigation options that control nutrient and fine sediment pollution at source, and address polluted runoff pathways at increasing spatial scale. The principal agricultural practices in the study sub-catchment (1.5 km2) are dairy and stock production. Farm yards can act as significant pollution sources by housing large numbers of animals; these areas are addressed initially with infrastructure improvements e.g. clean/dirty water separation and upgraded waste storage. In-stream high resolution monitoring of hydrology and water quality parameters showed high-discharge events to account for the majority of pollutant exports ( 80% total phosphorus; 95% fine sediment), and primary transfer routes to be surface and shallow sub-surface flow pathways, including drains. To manage these pathways and reduce hydrological connectivity, a series of mitigation features were constructed to intercept and temporarily store runoff. Farm tracks, field drains, first order ditches and overland flow pathways were all targeted. The efficacy of the mitigation features has been monitored at event and annual scale, using inflow-outflow sampling and sediment/nutrient accumulation measurements, respectively. Data presented here show varied but positive results in terms of reducing acute and chronic sediment and nutrient losses. An aerial fly-through of the catchment is used to demonstrate how the TT has been applied to a fully-functioning agricultural landscape. The elevated perspective provides a better understanding of the spatial arrangement of mitigation features, and how they can be

  1. Role of rural solid waste management in non-point source pollution control of Dianchi Lake catchments, China

    Institute of Scientific and Technical Information of China (English)

    Wenjing LU; Hongtao WANG

    2008-01-01

    In recent years, with control of the main municipal and industrial point pollution sources and implementation of cleaning for some inner pollution sources in the water body, the discharge of point source pollution decreased gradually, while non-point source pollution has become increasingly distressing in Dianchi Lake catchments. As one of the major targets in non-point source pollution control, an integrated solid waste controlling strategy combined with a technological solution and management system was proposed and implemented based on the waste disposal situation and characteristics of rural solid waste in the demonstration area. As the key technoogy in rural solid waste treatment, both centralized plantscale composting and a dispersed farmer-operated waste treating system showed promise in rendering timely benefits in efficiency, large handling capacity, high quality of the end product, as well as good economic return. Problems encountered during multi-substrates co-com-posting such as pathogens, high moisture content, asyn-chronism in the decomposition of different substrates, and low quality of the end product can all be tackled. 92.5% of solid waste was collected in the demonstration area, while the treating and recycling ratio reached 87.9%, which pre-vented 32.2 t nitrogen and 3.9 t phosphorus per year from entering the water body of Dianchi Lake after imple-mentation of the project.

  2. Open Source GIS based integrated watershed management

    Science.gov (United States)

    Byrne, J. M.; Lindsay, J.; Berg, A. A.

    2013-12-01

    Optimal land and water management to address future and current resource stresses and allocation challenges requires the development of state-of-the-art geomatics and hydrological modelling tools. Future hydrological modelling tools should be of high resolution, process based with real-time capability to assess changing resource issues critical to short, medium and long-term enviromental management. The objective here is to merge two renowned, well published resource modeling programs to create an source toolbox for integrated land and water management applications. This work will facilitate a much increased efficiency in land and water resource security, management and planning. Following an 'open-source' philosophy, the tools will be computer platform independent with source code freely available, maximizing knowledge transfer and the global value of the proposed research. The envisioned set of water resource management tools will be housed within 'Whitebox Geospatial Analysis Tools'. Whitebox, is an open-source geographical information system (GIS) developed by Dr. John Lindsay at the University of Guelph. The emphasis of the Whitebox project has been to develop a user-friendly interface for advanced spatial analysis in environmental applications. The plugin architecture of the software is ideal for the tight-integration of spatially distributed models and spatial analysis algorithms such as those contained within the GENESYS suite. Open-source development extends knowledge and technology transfer to a broad range of end-users and builds Canadian capability to address complex resource management problems with better tools and expertise for managers in Canada and around the world. GENESYS (Generate Earth Systems Science input) is an innovative, efficient, high-resolution hydro- and agro-meteorological model for complex terrain watersheds developed under the direction of Dr. James Byrne. GENESYS is an outstanding research and applications tool to address

  3. A Method for Source-load Allocation of Nutrients in Agricultural Watersheds

    Science.gov (United States)

    Burkart, M. R.; James, D. E.

    2001-12-01

    Identification of pollutant sources is critical to solving water resource contamination problems. Non-point sources of agricultural pollution provide substantial challenges to quantifying and allocating the sources of contaminants to streams. A method is presented for identifying the spatial variability of nitrogen and phosphorus sources and allocating proportional responsibility for source-reduction. The method is applied to data at scales ranging from hydrologic regions (2-digit hydrologic accounting units) of the Mississippi drainage basin to the public land survey grid in two small (14-digit) watersheds. A mass balance of nutrient sources and losses is estimated using georeferenced data derived from national to local digital data bases. Nitrogen excess is estimated by balancing sources associated with inorganic fertilizer, manure, crop fixation, mineralization of organic matter, and atmospheric redeposition of ammonia with losses from crop harvest, plant senescence, denitrification, and volatilization of manure and inorganic fertilizer. Phosphorus sources from inorganic fertilizer and manure are balanced with losses due to crop harvest. Allocation in regional units allows targeting of major pollutant source areas while smaller aggregation areas define greater ranges of source-loads useful for specific allocation. Manure sources control the distribution of excess nutrients at many scales, particularly in watersheds with uniform cropping systems. Absolute values of excess N sources provide substantially different allocation patterns than proportional values of total source-loads. Selection of aggregation scale is critical to source-load allocation needed to define TMDLs, monitor loads, and establish water-quality remediation strategies. >http://www.nstl.gov/pubs/burkart/trends/index.html

  4. Modelling of point and non-point source pollution of nitrate with SWAT in the river Dill, Germany

    OpenAIRE

    T. Pohlert; J. A. Huisman; L. Breuer; Frede, H.-G.

    2005-01-01

    International audience; We used the Soil and Water Assessment Tool (SWAT) to simulate point and non-point source pollution of nitrate in a mesoscale mountainous catchment. The results show that the model efficiency for daily discharge is 0.81 for the calibration period (November 1990 to December 1993) and 0.56 for the validation period (April 2000 to January 2003). The model efficiency for monthly nitrate load is 0.66 and 0.77 for the calibration period (April 2000 to March 2002) and validati...

  5. Farmers’ Willingness to Pay( WTP ) for Reducing Agricultural Non-point Source Pollution: Based on the Empirical Analysis of 453 Farmers

    Institute of Scientific and Technical Information of China (English)

    Qian; BI; Huaiye; WANG; Yongyan; ZUO

    2014-01-01

    With the rapid development of modern agriculture,agricultural non-point source pollution becomes increasingly serious in China,improving farmers’ environmental protection consciousness plays a very important role in the reduction of agricultural non-point source pollution,and the WTP of Farmers for controlling agricultural non-point source pollution strongly reflects the strength of their environmental protection consciousness. Therefore,this investigation and study choose rural areas of five counties from Chongqing city and Zhejiang province as our sample,respectively make interview survey with the WTP(money or voluntary work) of farmers for improving local water and soil quality. Based on the statistical analysis of survey data,this study also takes empirical test and analysis with the influence factors on the WTP of farmers for reducing agricultural non-point source pollution. The analysis and conclusions of this research provides the supports in theory and practice for optimizing farmers’ behavior,promoting the management of agricultural non-point source pollution and implementing new rural construction goal.

  6. {sup 37}Cl, {sup 15}N, {sup 13}C isotopic analysis of common agro-chemicals for identifying non-point source agricultural contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Annable, W.K. [Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)]. E-mail: wkannabl@uwaterloo.ca; Frape, S.K. [Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Shouakar-Stash, O. [Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Shanoff, T. [Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Drimmie, R.J. [Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Harvey, F.E. [School of Natural Resources, University of Nebraska, Lincoln, NE 68588-0517 (United States)

    2007-07-15

    The isotopic compositions of commercially available herbicides were analyzed to determine their respective {sup 15}N, {sup 13}C and {sup 37}Cl signatures for the purposes of developing a discrete tool for tracing and identifying non-point source contaminants in agricultural watersheds. Findings demonstrate that of the agrochemicals evaluated, chlorine stable isotopes signatures range between {delta}{sup 37}Cl = -4.55 per mille and +3.40 per mille , whereas most naturally occurring chlorine stable isotopes signatures, including those of road salt, sewage sludge and fertilizers, vary in a narrow range about the Standard Mean Ocean Chloride (SMOC) between -2.00 per mille and +1.00 per mille . Nitrogen stable isotope values varied widely from {delta}{sup 15}N = -10.86 per mille to +1.44 per mille and carbon stable isotope analysis gave an observed range between {delta}{sup 13}C = -37.13 per mille and -21.35 per mille for the entire suite of agro-chemicals analyzed. When nitrogen, carbon and chlorine stable isotope analyses were compared in a cross-correlation analysis, statistically independent isotopic signatures exist suggesting a new potential tracer tool for identifying herbicides in the environment.

  7. Catalog of Federal Funding Sources for Watershed Protection

    Data.gov (United States)

    U.S. Environmental Protection Agency — Catalog of Federal Funding Sources for Watershed Protection Web site is a searchable database of financial assistance sources (grants, loans) available to fund a...

  8. Sources and transport of nitrogen in arid urban watersheds

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Rebecca L.; Turnbull, Laura; Earl, Stevan; Grimm, Nancy B.; Riha, Krystin M.; Michalski, Greg; Lohse, Kathleen; Childers, Daniel L.

    2014-06-03

    Urban watersheds are often sources of nitrogen (N) to downstream systems, contributing to poor water quality. However, it is unknown which components (e.g., land cover and stormwater infrastructure type) of urban watersheds contribute to N export and which may be sites of retention. In this study we investigated which watershed characteristics control N sourcing, biogeochemical processing of nitrate (NO3–) during storms, and the amount of rainfall N that is retained within urban watersheds. We used triple isotopes of NO3– (δ15N, δ18O, and Δ17O) to identify sources and transformations of NO3– during storms from 10 nested arid urban watersheds that varied in stormwater infrastructure type and drainage area. Stormwater infrastructure and land cover—retention basins, pipes, and grass cover—dictated the sourcing of NO3– in runoff. Urban watersheds can be strong sinks or sources of N to stormwater depending on the proportion of rainfall that leaves the watershed as runoff, but we found no evidence that denitrification occurred during storms. Our results suggest that watershed characteristics control the sources and transport of inorganic N in urban stormwater but that retention of inorganic N at the timescale of individual runoff events is controlled by hydrologic, rather than biogeochemical, mechanisms.

  9. Microbial source tracking in impaired watersheds using PhyloChip and machine-learning classification.

    Science.gov (United States)

    Dubinsky, Eric A; Butkus, Steven R; Andersen, Gary L

    2016-11-15

    Sources of fecal indicator bacteria are difficult to identify in watersheds that are impacted by a variety of non-point sources. We developed a molecular source tracking test using the PhyloChip microarray that detects and distinguishes fecal bacteria from humans, birds, ruminants, horses, pigs and dogs with a single test. The multiplexed assay targets 9001 different 25-mer fragments of 16S rRNA genes that are common to the bacterial community of each source type. Both random forests and SourceTracker were tested as discrimination tools, with SourceTracker classification producing superior specificity and sensitivity for all source types. Validation with 12 different mammalian sources in mixtures found 100% correct identification of the dominant source and 84-100% specificity. The test was applied to identify sources of fecal indicator bacteria in the Russian River watershed in California. We found widespread contamination by human sources during the wet season proximal to settlements with antiquated septic infrastructure and during the dry season at beaches during intense recreational activity. The test was more sensitive than common fecal indicator tests that failed to identify potential risks at these sites. Conversely, upstream beaches and numerous creeks with less reliance on onsite wastewater treatment contained no fecal signal from humans or other animals; however these waters did contain high counts of fecal indicator bacteria after rain. Microbial community analysis revealed that increased E. coli and enterococci at these locations did not co-occur with common fecal bacteria, but rather co-varied with copiotrophic bacteria that are common in freshwaters with high nutrient and carbon loading, suggesting runoff likely promoted the growth of environmental strains of E. coli and enterococci. These results indicate that machine-learning classification of PhyloChip microarray data can outperform conventional single marker tests that are used to assess health

  10. SWAT模型在大洋河流域非点源污染模拟中的运用研究%The application of the SWAT model in a non-point source pollution in the Dayang River basin

    Institute of Scientific and Technical Information of China (English)

    刘晓哲

    2015-01-01

    Based on the SWAT model to Ocean River watershed for the study, quantitative modeling of the ocean River 2000 - -2010 Pollution, the results show that non-point source: SWAT model is appropriate for non-point source pollu-tion ocean river basin model parameters of periodic and verification simulation of total nitrogen and total phosphorus relative er-ror is less than 30%, the simulation uncertainty factor of 0. 5 or more, to meet the non-point source pollution simulation ac-curacy; total nitrogen and total phosphorus peak ocean River mainly 7 - September. Research for Ocean River water environ-mental protection and governance provide a reference value.%基于SWAT模型,以大洋河流域为研究流域,定量模拟了大洋河流域2000 -2010 年非点源污染,研究结果表明:SWAT模型适合于大洋河流域的非点源污染模拟,模型在参数率定期和验证模拟总氮和总磷相对误差均小于30%,模拟确定性系数达到0. 5 以上,满足流域非点源污染模拟精度要求;大洋河流域总氮和总磷峰值主要集中在7 -9 月份. 研究成果对于大洋河流域水环境保护和治理提供参考价值.

  11. 非点源污染负荷模型的研究进展%Research Progress of Non-point Source Pollution Models in Water Environment

    Institute of Scientific and Technical Information of China (English)

    姚瑞华; 王东; 赵越; 张晶

    2012-01-01

    Based on non-point source load model research at home and abroad, in accordance of the agriculture, urban and mixed non-point source models, the main conditions for the application model were summarized, and the development of non-point source model was prospected.%基于国内外非点源负荷污染模型的研究现状,针对农业、城市和混合三种类型非点源模型,总结并梳理了主要模型的适用条件,并对非点源模型的发展趋势进行了展望.

  12. The Non-point Source Pollution Effects of Pesticides Based on the Survey of 340 Farmers in Chongqing City

    Institute of Scientific and Technical Information of China (English)

    Lianchao; YU; Limeng; GU; Qian; BI

    2015-01-01

    Using the survey data on 340 farmers in Chongqing City,this paper performs an empirical analysis of the factors influencing the non-point source pollution of pesticides. The results show that the older householders will apply more pesticides,which may be due to the weak physical strength and weak ability to accept the concept of advanced cultivation; the householders with high level of education will choose to use less pesticides; the pesticide application rate is negatively correlated with whether farmers have participated in agricultural technology training,that is,the farmers having participated in agricultural technology training have stronger ability to scientifically apply pesticides,and in-depth understanding of advanced agricultural production technology and positive and negative effects of pesticides,so they often choose to reduce the application rate of pesticide; the cognitive factor on the role of pesticides in better promoting the growth of crops is significant,which requires the government and relevant departments to carry out concrete publicity of effectiveness and negative impact of different pesticides during the popularization of agricultural science knowledge,to prompt farmers to have a systematic and in-depth understanding of the agricultural nonpoint source pollution caused by pesticides.

  13. Analysis of Nonpoint Source Pollution and Water Environmental Quality Variation Trends in the Nansi Lake Basin from 2002 to 2012

    Directory of Open Access Journals (Sweden)

    Weiliang Wang

    2015-01-01

    Full Text Available Based on the data analysis of economic development and the water environmental quality from 2002 to 2012 in the Nansi Lake Basin in China, the correlation between economic development and the water environmental quality was researched. Analysis shows that the GDP of the Nansi Lake Basin had an average annual growth of 7.3% in 2012, and the COD and CODMn had the average annual decrease of 7.69% and 6.79%, respectively, compared to 2002. Basin water environmental quality overall improved, reaching Class III of the “Environmental quality standards for surface water (GB3838-2002.” The pollution of the water environment was analyzed from three aspects: agricultural fertilizers and pesticides, livestock, and aquaculture. Results indicated that the water pollution of the Nansi Lake Basin mainly came from nonpoint source pollution, accounting for more than 80% of the overall pollution. The contributions of both agricultural fertilizers and pesticides account for more than 85% of the overall nonpoint source, followed by livestock and aquaculture. According to the water pollution characteristics of the Nansi Lake Basin, the basin pollution treatment strategy and prevention and treatment system were dissected, to solve the pollution problem of the Nansi Lake Basin.

  14. Sources and transport of nitrogen in arid urban watersheds.

    Science.gov (United States)

    Hale, Rebecca L; Turnbull, Laura; Earl, Stevan; Grimm, Nancy; Riha, Krystin; Michalski, Greg; Lohse, Kathleen A; Childers, Daniel

    2014-06-03

    Urban watersheds are often sources of nitrogen (N) to downstream systems, contributing to poor water quality. However, it is unknown which components (e.g., land cover and stormwater infrastructure type) of urban watersheds contribute to N export and which may be sites of retention. In this study we investigated which watershed characteristics control N sourcing, biogeochemical processing of nitrate (NO3-) during storms, and the amount of rainfall N that is retained within urban watersheds. We used triple isotopes of NO3- (δ15N, δ18O, and Δ17O) to identify sources and transformations of NO3- during storms from 10 nested arid urban watersheds that varied in stormwater infrastructure type and drainage area. Stormwater infrastructure and land cover--retention basins, pipes, and grass cover--dictated the sourcing of NO3- in runoff. Urban watersheds were strong sinks or sources of N to stormwater depending on runoff, which in turn was inversely related to retention basin density and positively related to imperviousness and precipitation. Our results suggest that watershed characteristics control the sources and transport of inorganic N in urban stormwater but that retention of inorganic N at the time scale of individual runoff events is controlled by hydrologic, rather than biogeochemical, mechanisms.

  15. Modelling of point and non-point source pollution of nitrate with SWAT in the river Dill, Germany

    Directory of Open Access Journals (Sweden)

    T. Pohlert

    2005-01-01

    Full Text Available We used the Soil and Water Assessment Tool (SWAT to simulate point and non-point source pollution of nitrate in a mesoscale mountainous catchment. The results show that the model efficiency for daily discharge is 0.81 for the calibration period (November 1990 to December 1993 and 0.56 for the validation period (April 2000 to January 2003. The model efficiency for monthly nitrate load is 0.66 and 0.77 for the calibration period (April 2000 to March 2002 and validation period (April 2002 to January 2003, respectively. However, the model efficiency for daily loads is low (0.15, which cannot only be attributed to the quality of input data of point source effluents. An analysis of the internal fluxes and cycles of nitrogen pointed out considerable weaknesses in the models conceptualisation of the nitrogen modules which will be improved in future research.

  16. A West Virginia case study: does erosion differ between streambanks clustered by the bank assessment of nonpoint source consequences of sediment (BANCS) model parameters?

    Science.gov (United States)

    Abby L. McQueen; Nicolas P. Zegre; Danny L. Welsch

    2013-01-01

    The integration of factors and processes responsible for streambank erosion is complex. To explore the influence of physical variables on streambank erosion, parameters for the bank assessment of nonpoint source consequences of sediment (BANCS) model were collected on a 1-km reach of Horseshoe Run in Tucker County, West Virginia. Cluster analysis was used to establish...

  17. Estimation of contribution from non-point sources to perfluorinated surfactants in a river by using boron as a wastewater tracer.

    Science.gov (United States)

    Nishikoori, Hiroshi; Murakami, Michio; Sakai, Hiroshi; Oguma, Kumiko; Takada, Hideshige; Takizawa, Satoshi

    2011-08-01

    The contribution of non-point sources to perfluorinated surfactants (PFSs) in a river was evaluated by estimating their fluxes and by using boron (B) as a tracer. The utility of PFSs/B as an indicator for evaluating the impact of non-point sources was demonstrated. River water samples were collected from the Iruma River, upstream of the intake of drinking water treatment plants in Tokyo, during dry weather and wet weather, and 13 PFSs, dissolved organic carbon (DOC), total nitrogen (TN), and B were analyzed. Perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUA), and perfluorododecanoate (PFDoDA) were detected on all sampling dates. The concentrations and fluxes of perfluorocarboxylates (PFCAs, e.g. PFOA and PFNA) were higher during wet weather, but those of perfluoroalkyl sulfonates (PFASs, e.g. PFHxS and PFOS) were not. The wet/dry ratios of PFSs/B (ratios of PFSs/B during wet weather to those during dry weather) agreed well with those of PFS fluxes (ratios of PFS fluxes during wet weather to those during dry weather), indicating that PFSs/B is useful for evaluating the contribution from non-point sources to PFSs in rivers. The wet/dry ratios of PFOA and PFNA were higher than those of other PFSs, DOC, and TN, showing that non-point sources contributed greatly to PFOA and PFNA in the water. This is the first study to use B as a wastewater tracer to estimate the contribution of non-point sources to PFSs in a river.

  18. Linking Watershed Nitrogen Sources with Nitrogen Dynamics in Rivers of Western Oregon, USA

    Science.gov (United States)

    Sobota, D. J.; Compton, J.; Goodwin, K. E.

    2012-12-01

    We constructed contemporary nitrogen (N) budgets for 25 river basins in the Willamette River Basin (WRB) of western Oregon, USA, to improve the understanding of how recent trends in human-driven N loading have influenced riverine N dynamics in the region. Nearly 20% of WRB stream length is currently in fair or poor condition because of high N concentrations. Additionally, nitrate contamination of drinking water affects at least 8,000 people in the WRB. We hypothesized that 1) the majority of N inputs in the WRB would originate from agricultural activities in lowland portions of watersheds, 2) annual riverine N yield (kg/ha/yr) would correspond to annual per area watershed N inputs, and 3) riverine N yields would be seasonal and highest during winter due to the region's Mediterranean climate. We calculated average annual N inputs for each study basin by summing newly available datasets describing spatially explicit N inputs of synthetic fertilizer, atmospheric deposition, crop biological N2 fixation, biological N2 fixation by red alder (Alnus rubra Bong.), livestock manure, and point sources for the period 1996 - 2007. Annual and seasonal riverine N exports were estimated with the USGS model LOADEST calibrated to N concentration data collected during the study period. We estimated that two-thirds of total N input to the WRB study basins in the 2000s came from synthetic fertilizer application. Nearly all fertilizer application occurred on the lowlands near watershed mouths. We found a wide range of riverine N yields from the study basins, ranging from one to 70 kg N/ha/yr. Across the study basins, N export was more strongly correlated to fertilizer application rates than to percent of agricultural area in the watershed. Low watershed N yields reflected a high proportion of watershed area in the forested Cascade Mountain Range, which received low N inputs mainly from atmospheric deposition. N yields from study basins were strongly seasonal, with at least 50%, and

  19. Watershed runoff and sediment transport impacts from management decisions using integrated AnnAGNPS and CCHE1D models

    Science.gov (United States)

    Conservation planning tools that consider all sources of erosion, sheet and rill, gully, and channels, is critical to developing an effective watershed management plan that considers the integrated effect of all practices on the watershed system. The Annualized Agricultural Non-Point Source polluta...

  20. SWAT: Agricultural water and nonpoint source pollution management at a watershed scale

    Science.gov (United States)

    Global change and demographic changes increasingly cause water, food, and health problems in many areas of the world. In addition, the growth in bioenergy production leads to land-use change and associated environmental impacts. The lack of integration in resource assessments and policy-making leads...

  1. COST-EFFECTIVE ALLOCATION OF WATERSHED MANAGEMENT PRACTICES USING A GENETIC ALGORITHM

    Science.gov (United States)

    Implementation of conservation programs are perceived as being crucial for restoring and protecting waters and watersheds from non-point source pollution. Success of these programs depends to a great extent on planning tools that can assist the watershed management process. Here-...

  2. Application of modified export coefficient method on the load estimation of non-point source nitrogen and phosphorus pollution of soil and water loss in semiarid regions.

    Science.gov (United States)

    Wu, Lei; Gao, Jian-en; Ma, Xiao-yi; Li, Dan

    2015-07-01

    Chinese Loess Plateau is considered as one of the most serious soil loss regions in the world, its annual sediment output accounts for 90 % of the total sediment loads of the Yellow River, and most of the Loess Plateau has a very typical characteristic of "soil and water flow together", and water flow in this area performs with a high sand content. Serious soil loss results in nitrogen and phosphorus loss of soil. Special processes of water and soil in the Loess Plateau lead to the loss mechanisms of water, sediment, nitrogen, and phosphorus are different from each other, which are greatly different from other areas of China. In this study, the modified export coefficient method considering the rainfall erosivity factor was proposed to simulate and evaluate non-point source (NPS) nitrogen and phosphorus loss load caused by soil and water loss in the Yanhe River basin of the hilly and gully area, Loess Plateau. The results indicate that (1) compared with the traditional export coefficient method, annual differences of NPS total nitrogen (TN) and total phosphorus (TP) load after considering the rainfall erosivity factor are obvious; it is more in line with the general law of NPS pollution formation in a watershed, and it can reflect the annual variability of NPS pollution more accurately. (2) Under the traditional and modified conditions, annual changes of NPS TN and TP load in four counties (districts) took on the similar trends from 1999 to 2008; the load emission intensity not only is closely related to rainfall intensity but also to the regional distribution of land use and other pollution sources. (3) The output structure, source composition, and contribution rate of NPS pollution load under the modified method are basically the same with the traditional method. The average output structure of TN from land use and rural life is about 66.5 and 17.1 %, the TP is about 53.8 and 32.7 %; the maximum source composition of TN (59 %) is farmland; the maximum source

  3. Study on Control Countermeasures of Agricultural Non-point Source Pollution in Lakeside Belt of Poyang Lake——Taking Duchang Section in the Lower Reaches of Poyang Lake as Example

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the control countermeasures of agricultural non-point source pollution in lakeside belt of Poyang Lake.[Method] The current situation of water quality of Poyang Lake was analyzed firstly,then the causes of agricultural non-point source pollution in Duchang section of Poyang Lake were studied,finally corresponding control countermeasures were put forward.[Result] Agricultural non-point source pollution in Duchang section of Poyang Lake was mainly related to the rapid developm...

  4. Assessment of nonpoint-source contamination of the High Plains Aquifer in south-central Kansas, 1987

    Science.gov (United States)

    Helgesen, John O.; Stullken, Lloyd E.; Rutledge, A.T.

    1994-01-01

    Ground-water quality was assessed in a 5,000-square-mile area of the High Plains aquifer in south-central Kansas that is susceptible to nonpoint-source contamination from agricultural and petroleum-production activities. Of particular interest was the presence of agricultural chemicals and petroleum-derived hydrocarbons that might have been associated with brines that formerly were disposed into unlined ponds. Random sampling of ground water was done within a framework of discrete land-use areas (irrigated cropland, petroleum-production land containing former brine-disposal ponds, and undeveloped rangeland) of 3-10 square miles. Although true baseline water-quality conditions probably are rare, in this region they are represented most closely by ground water in areas of undeveloped rangeland. The sampling design enabled statistical hypothesis testing, using nonparametric procedures, of the effects of land use, unsaturated-zone lithology, and type of well sampled. Results indicate that regional ground-water quality has been affected by prevailing land-use activities, as shown by increased concentrations of several inorganic constituents. Ground water beneath irrigated cropland was characterized by significantly larger concentrations of hardness, alkalinity, calcium, magnesium, potassium, fluofide, and nitrite plus nitrate than was water beneath undeveloped rangeland. Few nondegraded pesticides were detected in the aquifer, probably because of degradation and sorption. Atrazine was the most common, but only in small concentrations. round water beneath petroleum-production land was characterized by significantly larger concentrations of hardness, alkalinity, dissolved solids, sodium, and chloride than was water beneath undeveloped rangeland. Nonpoint-source contamination by oil-derived hydrocarbons was not discernible. The occurrences of trace organic compounds were similar between petroleum-production land and undeveloped rangeland, which indicates a natural origin

  5. Evaluation of nonpoint-source contamination, Wisconsin: Selected data for 1992 water year

    Science.gov (United States)

    Graczyk, D.J.; Walker, J.F.; Greb, S.R.; Corsi, Steven R.; Owens, D.W.

    1993-01-01

    This report presents the annual results of the U.S. Geological Survey's (USGS) watershed-management evaluation monitoring program in Wisconsin. The overall objective of each individual project in the program is to determine if the water chemistry in the receiving stream has changed as a result of the implementation of land-management practices in the watershed. This is accomplished through monitoring of water chemistry and ancillary variables before best-management practices (BMP's) are installed ('pre-BMP'), during installation ('transitional'), and after ('post-BMP') watershed- management plans have been completely implemented. Fecal-coliform (FC) counts ranged between 10 and 310,00/100 mL. A large range of values occurred within duplicate and triplicate samples as well as over time. The median percentage difference between duplicate and triplicate samples was 17 percent although 4 out of the total 60 duplicate and triplicate samples had differences greater than 100 percent. A decrease in FC counts generally occurred over the duration of the 4-day analyses. Linear regression models of the log-concentration values (dependent variable) with respect to time (independent variable) were calculated for all samples. Negative slopes were found for 14 of the 15 samples. Slopes varied from +0.5 to -38.4 percent gain/loss/day, with a median slope of -8.5 percent/day. A t-test was applied to the data to examine whether or not significant differences in FC counts exist with respect to holding times. Because the T-test only compares two treatments, the test was conducted 3 times (0 versus 24-hr holding time, 0 versus 48-hr holding time, and 0 versus 72-hr holding time). Setting the level of significance at p less than 0.05 and assuming equal variances, 27 percent (all from Bower and Otter Creeks) of the samples demonstrated a significant difference in colony count over the first 24 hr, 40 percent over 48 hr, and 47 percent over 72 hr. All samples that exhibited a significant

  6. Assessment of the impacts of land use changes on nonpoint source pollution inputs upstream of the Three Gorges Reservoir.

    Science.gov (United States)

    Yang, Huicai; Wang, Guoqiang; Yang, Yan; Xue, Baolin; Wu, Binbin

    2014-01-01

    In recent years, land use upstream of the Three Gorges Reservoir (TGR) has changed significantly because of the TGR project. In this study, the Soil and Water Assessment Tool (SWAT) model was examined for its ability to assess relationships between land use changes and nonpoint pollutant indexes upstream of the TGR. Results indicated that the SWAT model, calibrated with the adjusted parameters, could successfully reproduce the nonpoint indexes at the water quality monitoring sites in the two rivers. The different land use change types were shown to be sensitive to nonpoint pollutants in the study area. The land use change type from upland to water was the strongest influence on changes in total nitrogen and total phosphorus. An empirical regression equation between nonpoint indexes and different land use change types was developed for the study area by partial least squares regression (PLSR) as follows: Y = b 0 + ∑ i=1 (m) b i X i. This regression equation was useful for evaluating the influence of land use change types on changes in nonpoint pollutants over a long time period. The results from this study may be useful for the TGR management and may help to reduce nonpoint pollutant loads into downstream water bodies.

  7. Impact of Point and Non-point Source Pollution on Coral Reef Ecosystems In Mamala Bay, Oahu, Hawaii based on Water Quality Measurements and Benthic Surveys in 1993-1994 (NODC Accession 0001172)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The effects of both point and non-point sources of pollution on coral reef ecosystems in Mamala Bay were studied at three levels of biological organization; the...

  8. 农业非点源污染研究进展和趋势%The Progress and Trends of Agricultural Non-point Source Pollution Research

    Institute of Scientific and Technical Information of China (English)

    李丽华; 李强坤

    2014-01-01

    根据国内外农业非点源污染研究现状,本文在探讨农业非点源污染内涵及其特征的基础上,简要总结了农业非点源污染负荷的估算模型,列举区域农业非点源污染风险评估的手段和方法,从不同角度归纳了农业非点源污染的控制技术,并提出了近期农业非点源污染急需研究的热点和趋势,以期为进一步的农业非点源污染管理和控制提供参考。%According to the current research on agricultural non-point source pollution at home and abroad, the connotation and feature of a-gricultural non-point source pollution were explored in this paper, and then the estimating model of pollution load was concluded briefly. Meanwhile, the paper also listed the means and methods of risk assessment of regional agricultural non-point source pollution and summed up the control technologies from different angles. Finally, the recent much-needed research hotspots and trends were put forward in order to provide reference for further management and control of agricultural non-point source pollution.

  9. Estimating the benefits of land imagery in environmental applications: a case study in nonpoint source pollution of groundwater

    Science.gov (United States)

    Bernknopf, Richard L.; Forney, William M.; Raunikar, Ronald P.; Mishra, Shruti K.; Laxminarayan, Ramanan; Maccauley, Molly K.

    2012-01-01

    Moderate-resolution land imagery (MRLI) is crucial to a more complete assessment of the cumulative, landscape-level effect of agricultural land use and land cover on environmental quality. If this improved assessment yields a net social benefit, then that benefit reflects the value of information (VOI) from MRLI. Environmental quality and the capacity to provide ecosystem services evolve because of human actions, changing natural conditions, and their interaction with natural physical processes. The human actions, in turn, are constrained and redirected by many institutions and regulations such as agricultural, energy, and environmental policies. We present a general framework for bringing together sociologic, biologic, physical, hydrologic, and geologic processes at meaningful scales to interpret environmental implications of MRLI applications. We set out a specific application using MRLI observations to identify crop planting patterns and thus estimate surface management activities that influence groundwater resources over a regional landscape. We tailor the application to the characteristics of nonpoint source groundwater pollution hazards in Iowa to illustrate a general framework in a land use-hydrologic-economic system. In the example, MRLI VOI derives from reducing the risk of both losses to agricultural production and damage to human health and other consequences of contaminated groundwater.

  10. Governing change: land-use change and the prevention of nonpoint source pollution in the north coastal basin of California.

    Science.gov (United States)

    Short, Anne G

    2013-01-01

    Many rural areas in the United States and throughout much of the postindustrial world are undergoing significant ecological, socioeconomic, and political transformations. The migration of urban and suburban dwellers into rural areas has led to the subdivision of large tracts of land into smaller parcels, which can complicate efforts to govern human-environmental problems. Non-point source (NPS) pollution from private rural lands is a particularly pressing human-environmental challenge that may be aggravated by changing land tenure. In this article, I report on a study of the governance and management of sediment (a common NPS pollutant) in the North Coastal basin of California, a region undergoing a transition from traditional extractive and agricultural land uses to rural residential and other alternative land uses. I focus on the differences in the governance and management across private timber, ranch, residential, vacation, and other lands in the region. I find that (1) the stringency and strength of sediment regulations differ by land use, (2) nonregulatory programs tend to target working landscapes, and (3) rural residential landowners have less knowledge of sediment control and report using fewer sediment-control techniques than landowners using their land for timber production or ranching. I conclude with an exploration of the consequences of these differences on an evolving rural landscape.

  11. Severe situation of rural nonpoint source pollution and efficient utilization of agricultural wastes in the Three Gorges Reservoir Area.

    Science.gov (United States)

    Zhang, Tong; Ni, Jiupai; Xie, Deti

    2015-11-01

    Rural nonpoint source (NPS) pollution caused by agricultural wastes has become increasingly serious in the Three Gorges Reservoir Area (TGRA), significantly affecting the reservoir water quality. The grim situation of rural NPS pollution in the TGRA indicated that agrochemicals (chemical fertilizer and pesticide) were currently the highest contributor of rural NPS pollution (50.38%). The harmless disposal rates of livestock excrement, crop straws, rural domestic refuse, and sewage also cause severe water pollution. More importantly, the backward agricultural economy and the poor environmental awareness of farmers in the hinterland of the TGRA contribute to high levels of rural NPS pollution. Over the past decade, researchers and the local people have carried out various successful studies and practices to realize the effective control of rural NPS pollution by efficiently utilizing agricultural wastes in the TGRA, including agricultural waste biogas-oriented utilization, crop straw gasification, decentralized land treatment of livestock excrement technology, and crop straw modification. These technologies have greatly increased the renewable resource utilization of agricultural wastes and improved water quality and ecological environment in the TGRA.

  12. A distributed non-point source pollution model:calibration and validation in the Yellow River Basin

    Institute of Scientific and Technical Information of China (English)

    HAO Fang-bua; ZHANG Xue-song; YANG Zhi-feng

    2004-01-01

    The applicability of a non-point source pollution model-SWAT(soil and water assessment tools) in a large river basin with high sediment runoff modulus(770 t/km2 in the Yellow River) was examined. The basic database,which includes DEM, soil and landuse map, weather data, and land management data, was established for the study area using GIS. A two-stage "Brute Force" optimization method was used to calibrate the parameters with the observed monthly flow and sediment data from 1992 to 1997. In the process of calibration automated digital filter technique was used to separate direct runoff and base flow. The direct runoff was firstly calibrated, and the base flow, then the total runoff was matched. The sediment yield was calibrated to match well. Keeping input parameters set during the calibration process unchanged, the model was validated with 1998-1999's observed monthly flow and sediment. The evaluation coefficients for simulated and observed flow and sediment showed that SWAT was successfully applied in the study area: relative error was within 20%, coefficient of determination and Nash-Suttcliffe simulation efficiency were all equal to or above 0.70 during calibration and validation period.

  13. Assessment of the relationship between rural non-point source pollution and economic development in the Three Gorges Reservoir Area.

    Science.gov (United States)

    Zhang, Tong; Ni, Jiupai; Xie, Deti

    2016-04-01

    This study investigates the relationship between rural non-point source (NPS) pollution and economic development in the Three Gorges Reservoir Area (TGRA) by using the Environmental Kuznets Curve (EKC) hypothesis for the first time. Five types of pollution indicators, namely, fertilizer input density (FD), pesticide input density (PD), agricultural film input density (AD), grain residues impact (GI), and livestock manure impact (MI), were selected as rural NPS pollutant variables. Rural net income per capita was used as the indicator of economic development. Pollution load was generated by agricultural inputs (consumption of fertilizer, pesticide, and agricultural film) and economic growth with invert U-shaped features. The predicted turning points for FD, PD, and AD were at rural net income per capita levels of 6167.64, 6205.02, and 4955.29 CNY, respectively, which were all surpassed. However, the features between agricultural waste outputs (grain residues and livestock manure) and economic growth were inconsistent with the EKC hypothesis, which reflected the current trends of agricultural economic structure in the TGRA. Given that several other factors aside from economic development level could influence the pollutant generation in rural NPS, a further examination with long-run data support should be performed to understand the relationship between rural NPS pollution and income level.

  14. Non-point source analysis of a railway bridge area using statistical method: case study of a concrete road-bed.

    Science.gov (United States)

    Gil, Kyungik; Im, Jiyeol

    2014-06-01

    In an effort to protect the quality of the water system, interest in non-point source pollution is increasing. Recently, studies of non-point sources pollution are continuing in relation to various land-use areas, but such studies have not been fully conducted in railway facility sites. Using monitoring data of railway bridge area with concrete road-bed, the runoff characteristics, pollutant unit loads, and first flush criteria were assessed. Railway bridge area with concrete road-bed typically show the first flush effect, and the pollutant unit load was determined to be higher than other public facilities areas. Further, the first flush criteria show an effective rainfall amount of 7 mm. In other words, from the runoff of railway facilities, considerable amounts of non-point source pollutants are occurred, indicating the need to create best management practices which are adequate for railway facility sites. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  15. Stream restoration and sewers impact sources and fluxes of water, carbon, and nutrients in urban watersheds

    Science.gov (United States)

    Pennino, Michael J.; Kaushal, Sujay S.; Mayer, Paul M.; Utz, Ryan M.; Cooper, Curtis A.

    2016-08-01

    An improved understanding of sources and timing of water, carbon, and nutrient fluxes associated with urban infrastructure and stream restoration is critical for guiding effective watershed management globally. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in urban stream restoration and sewer infrastructure. We compared an urban restored stream with two urban degraded streams draining varying levels of urban development and one stream with upland stormwater management systems over a 3-year period. We found that there was significantly decreased peak discharge in response to precipitation events following stream restoration. Similarly, we found that the restored stream showed significantly lower (p exported most carbon, nitrogen, and phosphorus at relatively lower streamflow than the two more urban catchments, which exported most carbon and nutrients at higher streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha-1 yr-1), total nitrogen (4.5 ± 0.3 kg ha-1 yr-1), and total phosphorus (161 ± 15 kg ha-1 yr-1) were significantly lower in the restored stream compared to both urban degraded streams (p exports. However, nitrate isotope data suggested that 55 ± 1 % of the nitrate in the urban restored stream was derived from leaky sanitary sewers (during baseflow), statistically similar to the urban degraded streams. These isotopic results as well as additional tracers, including fluoride (added to drinking water) and iodide (contained in dietary salt), suggested that groundwater contamination was a major source of urban nutrient fluxes, which has been less considered compared to upland sources. Overall, leaking sewer pipes are a problem globally and our results suggest that combining stream restoration with restoration of aging sewer pipes can be critical to more effectively minimizing urban nonpoint nutrient sources. The sources, fluxes, and flowpaths of groundwater

  16. Nutrient inputs to the Laurentian Great Lakes by source and watershed estimated using SPARROW watershed models

    Science.gov (United States)

    Robertson, Dale M.; Saad, David A.

    2011-01-01

    Nutrient input to the Laurentian Great Lakes continues to cause problems with eutrophication. To reduce the extent and severity of these problems, target nutrient loads were established and Total Maximum Daily Loads are being developed for many tributaries. Without detailed loading information it is difficult to determine if the targets are being met and how to prioritize rehabilitation efforts. To help address these issues, SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were developed for estimating loads and sources of phosphorus (P) and nitrogen (N) from the United States (U.S.) portion of the Great Lakes, Upper Mississippi, Ohio, and Red River Basins. Results indicated that recent U.S. loadings to Lakes Michigan and Ontario are similar to those in the 1980s, whereas loadings to Lakes Superior, Huron, and Erie decreased. Highest loads were from tributaries with the largest watersheds, whereas highest yields were from areas with intense agriculture and large point sources of nutrients. Tributaries were ranked based on their relative loads and yields to each lake. Input from agricultural areas was a significant source of nutrients, contributing ∼33-44% of the P and ∼33-58% of the N, except for areas around Superior with little agriculture. Point sources were also significant, contributing ∼14-44% of the P and 13-34% of the N. Watersheds around Lake Erie contributed nutrients at the highest rate (similar to intensively farmed areas in the Midwest) because they have the largest nutrient inputs and highest delivery ratio.

  17. Anthropogenic point and non-point nitrogen inputs into Huai River Basin and their impacts on riverine ammonia-nitrogen flux

    Science.gov (United States)

    Zhang, W. S.; Swaney, D. P.; Li, X. Y.; Hong, B.; Howarth, R. W.; Ding, S. H.

    2015-02-01

    This study provides a new approach to estimate both anthropogenic non-point and point nitrogen (N) inputs to the landscape, and determines their impacts on riverine ammonia-nitrogen (AN) flux, providing a foundation for further exploration of anthropogenic effects on N pollution. Our study site is Huai River Basin of China, a watershed with one of the highest levels of N input in the world. Multi-year average (2003-2010) inputs of N to the watershed are 27 200 ± 1100 kg N km-2 yr-1. Non-point sources comprised about 98% of total N input and only 2% of inputs are directly added to the aquatic ecosystem as point sources. Fertilizer application was the largest non-point source of new N to the Huai River Basin (69% of net anthropogenic N inputs), followed by atmospheric deposition (20%), N fixation in croplands (7%), and N content of imported food and feed (2%). High N inputs showed impacts on riverine AN flux: fertilizer application, point N input and atmospheric N deposition were proved as more direct sources to riverine AN flux. Modes of N delivery and losses associated with biological denitrification in rivers, water consumption, interception by dams influenced the extent of export of riverine AN flux from N sources. Our findings highlight the importance of anthropogenic N inputs from point and non-point sources in heavily polluted watersheds, and provide some implications for AN prediction and management.

  18. Assessing the effects of rural livelihood transition on non-point source pollution: a coupled ABM-IECM model.

    Science.gov (United States)

    Yuan, Chengcheng; Liu, Liming; Ye, Jinwei; Ren, Guoping; Zhuo, Dong; Qi, Xiaoxing

    2017-04-02

    Water pollution caused by anthropogenic activities and driven by changes in rural livelihood strategies in an agricultural system has received increasing attention in recent decades. To simulate the effects of rural household livelihood transition on non-point source (NPS) pollution, a model combining an agent-based model (ABM) and an improved export coefficient model (IECM) was developed. The ABM was adopted to simulate the dynamic process of household livelihood transition, and the IECM was employed to estimate the effects of household livelihood transition on NPS pollution. The coupled model was tested in a small catchment in the Dongting Lake region, China. The simulated results reveal that the transition of household livelihood strategies occurred with the changes in the prices of rice, pig, and labor. Thus, the cropping system, land-use intensity, resident population, and number of pigs changed in the small catchment from 2000 to 2014. As a result of these changes, the total nitrogen load discharged into the river initially increased from 6841.0 kg in 2000 to 8446.3 kg in 2004 and then decreased to 6063.9 kg in 2014. Results also suggest that rural living, livestock, paddy field, and precipitation alternately became the main causes of NPS pollution in the small catchment, and the midstream region of the small catchment was the primary area for NPS pollution from 2000 to 2014. Despite some limitations, the coupled model provides an innovative way to simulate the effects of rural household livelihood transition on NPS pollution with the change of socioeconomic factors, and thereby identify the key factors influencing water pollution to provide valuable suggestions on how agricultural environmental risks can be reduced through the regulation of the behaviors of farming households in the future.

  19. Enabling and Enacting `Practical Action' in Catchments: Responding to the `Wicked Problem' of Nonpoint Source Pollution in Coastal Subtropical Australia

    Science.gov (United States)

    Patterson, James J.; Smith, Carl; Bellamy, Jennifer

    2015-02-01

    Enabling and enacting `practical action' (i.e., purposeful and concerted collective action) in catchments is a key challenge in responding to a wide range of pressing catchment and natural resource management (NRM) issues. It is particularly a challenge in responding to `wicked problems,' where generating action is not straightforward and cannot be brought about solely by any single actor, policy or intervention. This paper responds to the critical need to better understand how practical action can be generated in catchments, by conducting an in-depth empirical case study of efforts to manage nonpoint source (NPS) pollution in South East Queensland (SEQ), Australia. SEQ has seen substantial concerted efforts to manage waterway and catchment issues over two decades, yet NPS pollution remains a major problem for waterway health. A novel framework was applied to empirically analyze practical action in three local catchment cases embedded within the broader SEQ region. The analysis focuses on `enabling capacities' underpinning practical action in catchments. Findings reveal that capacities manifested in different ways in different cases, yet many commonalities also occurred across cases. Interplay between capacities was critical to the emergence of adaptive and contextual forms of practical action in all cases. These findings imply that in order to enable and enact practical action in catchments, it is vital to recognize and support a diversity of enabling capacities across both local and regional levels of decision making and action. This is likely to have relevance for other `wicked' catchment and NRM problems requiring local responses within broader multiscalar regional problem situations.

  20. Enabling and enacting 'practical action' in catchments: responding to the 'wicked problem' of nonpoint source pollution in coastal subtropical Australia.

    Science.gov (United States)

    Patterson, James J; Smith, Carl; Bellamy, Jennifer

    2015-02-01

    Enabling and enacting 'practical action' (i.e., purposeful and concerted collective action) in catchments is a key challenge in responding to a wide range of pressing catchment and natural resource management (NRM) issues. It is particularly a challenge in responding to 'wicked problems,' where generating action is not straightforward and cannot be brought about solely by any single actor, policy or intervention. This paper responds to the critical need to better understand how practical action can be generated in catchments, by conducting an in-depth empirical case study of efforts to manage nonpoint source (NPS) pollution in South East Queensland (SEQ), Australia. SEQ has seen substantial concerted efforts to manage waterway and catchment issues over two decades, yet NPS pollution remains a major problem for waterway health. A novel framework was applied to empirically analyze practical action in three local catchment cases embedded within the broader SEQ region. The analysis focuses on 'enabling capacities' underpinning practical action in catchments. Findings reveal that capacities manifested in different ways in different cases, yet many commonalities also occurred across cases. Interplay between capacities was critical to the emergence of adaptive and contextual forms of practical action in all cases. These findings imply that in order to enable and enact practical action in catchments, it is vital to recognize and support a diversity of enabling capacities across both local and regional levels of decision making and action. This is likely to have relevance for other 'wicked' catchment and NRM problems requiring local responses within broader multiscalar regional problem situations.

  1. Multi-angle Indicators System of Non-point Pollution Source Assessment in Rural Areas: A Case Study Near Taihu Lake

    Science.gov (United States)

    Huang, Lei; Ban, Jie; Han, Yu Ting; Yang, Jie; Bi, Jun

    2013-04-01

    This study aims to identify key environmental risk sources contributing to water eutrophication and to suggest certain risk management strategies for rural areas. The multi-angle indicators included in the risk source assessment system were non-point source pollution, deficient waste treatment, and public awareness of environmental risk, which combined psychometric paradigm methods, the contingent valuation method, and personal interviews to describe the environmental sensitivity of local residents. Total risk values of different villages near Taihu Lake were calculated in the case study, which resulted in a geographic risk map showing which village was the critical risk source of Taihu eutrophication. The increased application of phosphorus (P) and nitrogen (N), loss vulnerability of pollutant, and a lack of environmental risk awareness led to more serious non-point pollution, especially in rural China. Interesting results revealed by the quotient between the scores of objective risk sources and subjective risk sources showed what should be improved for each study village. More environmental investments, control of agricultural activities, and promotion of environmental education are critical considerations for rural environmental management. These findings are helpful for developing targeted and effective risk management strategies in rural areas.

  2. Distributed Simulation of Non-Point Source Pollution in Ashi River Basin

    Institute of Scientific and Technical Information of China (English)

    Fang Ma; Xiaofeng Jiang; Li Wang; Zhe Li; Xiongwei Liang

    2015-01-01

    In order to get a thorough understanding of non⁃point source pollution, it is essential to examine its temporal and spatial distribution. A physically⁃based distributed model, Soil and Water Assessment Tool ( SWAT) , was used in this research, to quantitatively estimate the NPS load and analyze the temporal and spatial distributions of NPS pollution in Ashi River Basin. The results indicated that SWAT was suitable to simulate stream⁃flow and water quality in Ashi River Basin. Total Nitrogen which was contributed by NPS (NPS⁃TN) accounted for 32�47%-62�61%, and Total Phosphorus which was contributed by NPS (NPS⁃TP) accounted for 22�30%-57�85% of the total load respectively. In inter⁃annual timescale, both NPS⁃TN and NPS⁃TP were influenced by stream⁃flow and fertilizer. However, when compared with fertilizer, NPS pollution was more directly affected by stream⁃flow. In annual timescale, NPS⁃TN and NPS⁃TP mainly occurred in flood season (from May to September). In the aspect of space, spatial differences of NPS⁃TN and NPS⁃TP were extremely significant. The spatial variations of NPS pollution were mainly influenced by land use, precipitation, soil and slope.

  3. New insight into the correlations between land use and water quality in a coastal watershed of China: Does point source pollution weaken it?

    Science.gov (United States)

    Zhou, Pei; Huang, Jinliang; Pontius, Robert Gilmore; Hong, Huasheng

    2016-02-01

    Uncovering the associations between land use and river water quality is useful for managing land-based pollution in the catchment-coast continuum. However, it is not clear how land use affects water quality in the context of simultaneous point source (PS) pollution. In this study, we develop a self-organizing map (SOM)-based approach to explore the relationship between land use and water quality in the Minjiang River Watershed, Southeast China. Water samples from 139 headwater sub-watersheds were associated with six land use categories, namely, Woodland, Agriculture, Orchard, Built-up, Unused land and Water. Sampling sites are delineated into six clusters based on six water quality parameters: ammonium-N, nitrate-N, total nitrogen, soluble reactive phosphate, total phosphate and potassium permanganate index. Local relationships between land use and water quality among four clusters that have sufficient sample sizes are further identified. There is no significant land use-water quality correlation in one of the four clusters (including 37 sub-watersheds). And the greater the PS pollution is, the less significant the land use-water quality correlations are in clusters. The results demonstrate how PS pollution weakens the land use-water quality correlation. Our method can help to determine whether non-point source or PS pollution exerts greater influence on the quality of the water coming from watershed. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Characterization of sources and loadings of fecal pollutants using microbial source tracking assays in urban and rural areas of the Grand River Watershed, Southwestern Ontario.

    Science.gov (United States)

    Lee, Dae-Young; Lee, Hung; Trevors, Jack T; Weir, Susan C; Thomas, Janis L; Habash, Marc

    2014-04-15

    Sources of fecal water pollution were assessed in the Grand River and two of its tributaries (Ontario, Canada) using total and host-specific (human and bovine) Bacteroidales genetic markers in conjunction with reference information, such as land use and weather. In-stream levels of the markers and culturable Escherichia coli were also monitored during multiple rain events to gain information on fecal loadings to catchment from diffuse sources. Elevated human-specific marker levels were accurately identified in river water impacted by a municipal wastewater treatment plant (WWTP) effluent and at a downstream site in the Grand River. In contrast, the bovine-specific marker showed high levels of cattle fecal pollution in two tributaries, both of which are characterized as intensely farmed areas. The bovine-specific Bacteroidales marker increased with rainfall in the agricultural tributaries, indicating enhanced loading of cattle-derived fecal pollutants to river from non-point sources following rain events. However, rain-triggered fecal loading was not substantiated in urban settings, indicating continuous inputs of human-originated fecal pollutants from point sources, such as WWTP effluent. This study demonstrated that the Bacteroidales source tracking assays, in combination with land use information and hydrological data, may provide additional insight into the spatial and temporal distribution of source-specific fecal contamination in streams impacted by varying land uses. Using the approach described in this study may help to characterize impacted water sources and to design targeted land use management plans in other watersheds in the future.

  5. Contaminant Sources in Stream Water of a Missouri Claypan Watershed

    Science.gov (United States)

    Peters, G. R.; Liu, F.; Lerch, R. N.; Lee, H.

    2014-12-01

    Elevated concentrations of nitrate-nitrogen and herbicides in stream water have degraded water quality and caused serious problems affecting human and aquatic ecosystem health in the Central Claypan Region of the US Midwest. However, the contribution of specific recharge sources to stream water is not well understood in claypan-dominated watersheds. The purpose of this study was to estimate the recharge sources to Goodwater Creek Experimental Watershed (GCEW) in north-central Missouri and investigate their importance to contaminant transport. Samples were collected from 2011 to 2014 from streams, piezometers, seep flows, and groundwater in GCEW and analyzed for major ions (including nitrate and nitrite), trace elements, stable H and O isotopes, total nitrogen (TN) and herbicides. Using an endmember mixing analysis based on conservative tracers, recharge contributions to stream flow were an average of 25% surface runoff, 44% shallow subsurface water, and 31% groundwater. TN concentrations were, on average, Atrazine concentrations were, on average, atrazine in stream water. An improved understanding of claypan hydrology and contaminant transport could lead to crop management practices that better protect surface water and groundwater in claypan-dominated watersheds.

  6. Detection of spatial fluctuations of non-point source fecal pollution in coral reef surrounding waters in southwestern Puerto Rico using PCR-based assays.

    Science.gov (United States)

    Bonkosky, M; Hernández-Delgado, E A; Sandoz, B; Robledo, I E; Norat-Ramírez, J; Mattei, H

    2009-01-01

    Human fecal contamination of coral reefs is a major cause of concern. Conventional methods used to monitor microbial water quality cannot be used to discriminate between different fecal pollution sources. Fecal coliforms, enterococci, and human-specific Bacteroides (HF183, HF134), general Bacteroides-Prevotella (GB32), and Clostridium coccoides group (CP) 16S rDNA PCR assays were used to test for the presence of non-point source fecal contamination across the southwestern Puerto Rico shelf. Inshore waters were highly turbid, consistently receiving fecal pollution from variable sources, and showing the highest frequency of positive molecular marker signals. Signals were also detected at offshore waters in compliance with existing microbiological quality regulations. Phylogenetic analysis showed that most isolates were of human fecal origin. The geographic extent of non-point source fecal pollution was large and impacted extensive coral reef systems. This could have deleterious long-term impacts on public health, local fisheries and in tourism potential if not adequately addressed.

  7. 拉萨河流域非点源污染输出风险评估%Risk assessment of non-point source pollution export in Lasahe basin

    Institute of Scientific and Technical Information of China (English)

    方广玲; 香宝; 杜加强; 王宝良; 张立坤; 胡钰; 徐杰

    2015-01-01

    Identification of the high risk area of non-point source pollution has important practical significance to control non-point source pollution and improve the water environment quality. Lasahe River basin located in the Tibet Autonomous Region of China is important drinking-water source for Lhasa City, Linzhou County and Dangxiong County. Because the underdevelopment of industry and the less discharge of industrial pollutants in this area, non-point source pollution is the most important contributing factor for water pollution. Lhasa River basin is the region of agricultural production base with the densest population in the Tibet Autonomous Region. This study built the output risk model that includes rainfall, topography, and fertilization influence factor, identification the output risk region unit from basin non-point source pollution at all levels object. The risk probability of non-point source pollution was classed into five levels: lowest, lower, moderate, higher and highest. Data used in this study were mainly from remote sensing image, statistical yearbook, and the parameters in output risk model were collected from the literatures. The results showed that risk probability of non-point source pollution output in 1996 and 2010 was 50%and 46.3%respectively. 17.5%in 1996 and 12.6%in 2010 of the study area showed that risk probability of non-point source pollution was more than 70%. The risk probability of non-point source pollution was spatially heterogeneous, corresponding with the attributes of land use types. The areas with highest risk of non-point source pollution were concentrated in farmland, where agricultural activities strengthened, and concentrated in unused land with great ecological vulnerability and sensitivity to external interference. Areas with lowest and lower risk of non-point source pollution mainly distributed in grassland, which has relative stability and robustness. Our study also found that risk probability of non-point source pollution

  8. 植草沟技术在面源污染控制中的研究进展%Advance on Grassed Swales Technology in Non-point Source Pollution Control

    Institute of Scientific and Technical Information of China (English)

    王健; 尹炜; 叶闽; 雷阿林; 李思敏

    2011-01-01

    Current research advances of non-point source pollution, especially urban non-point source pollution were introduced. Research advances and applications of grassed swales technology in non-point source pollution control were expounded. Main problems and application prospects of grassed swales technology in actual engineering were discussed as well. Coupling of grassed swales technology and other non-point source pollution control technology are proposed to be considered as a development direction in urban non-point source pollution control.%文章介绍了面源污染,尤其是城市面源污染的现状及其控制技术研究进展,并论述了植草沟技术的国内外研究进展及应用现状,讨论了其在工程中需解决的问题及应用前景,提出了植草沟技术与其他面源污染控制单项技术有机耦合是城市面源污染控制的一个发展方向.

  9. Headwater management alters sources, flowpaths, and fluxes of water, carbon, and nitrogen in urban watersheds

    Science.gov (United States)

    Pennino, M. J.; Kaushal, S.; Mayer, P. M.; Welty, C.; Miller, A. J.

    2012-12-01

    Increased urbanization has altered watershed hydrology and increased nutrient pollution, leading to eutrophication and hypoxia in downstream coastal ecosystems. Due to urban stream degradation, there have been efforts to restore streams and reduce peak-flow discharges and contaminant export through stormwater management and stream restoration. However, there have been relatively few studies comparing watershed scale impacts of contrasting headwater management practices on sources and fluxes of water, carbon, and nutrients across space and time. In this study we compared sources and fluxes of water, carbon (C), and nitrogen (N) along 4 watersheds of contrasting headwater management: 2 urban degraded watersheds with minimal or no stormwater management and 2 managed urban watersheds with stormwater controls and stream restoration. Surface water samples were collected biweekly at USGS gauging stations located within each watershed over 2 years. Spatially, watersheds were sampled longitudinally during 4 seasons. Sources of water, nitrate, and carbon were investigated using isotopic and spectroscopic tracer techniques. Indicator anions (F-, Cl-, I-, SO42-) were also used to trace anthropogenic vs. natural water sources. Hydrologic flowpaths (groundwater vs. overland flow) were assessed with longitudinal synoptic surveys using stable water isotopes of H and O. Annual fluxes of water, C, and N, were estimated using the USGS program LOADEST. H and O isotope data showed that the source of stream water is primarily groundwater during summer months, with greater contributions from stormflow during winter months for all 4 watersheds. Elevated levels of indicator anions (F-, Cl-, I-, SO42-) as well as greater "pulses" of C and N over time in the degraded vs. managed watersheds indicate potential sewage sources due to leaky sanitary sewers and greater stormdrain inputs. Unlike the managed watersheds where hydrologic flowpaths were from groundwater in headwaters, the longitudinal

  10. A dual-inexact fuzzy stochastic model for water resources management and non-point source pollution mitigation under multiple uncertainties

    Science.gov (United States)

    Dong, C.; Tan, Q.; Huang, G.-H.; Cai, Y.-P.

    2014-05-01

    In this research, a dual-inexact fuzzy stochastic programming (DIFSP) method was developed for supporting the planning of water and farmland use management system considering the non-point source pollution mitigation under uncertainty. The random boundary interval (RBI) was incorporated into DIFSP through integrating fuzzy linear programming (FLP) and chance-constrained programming (CCP) approaches within an interval linear programming (ILP) framework. This developed method could effectively tackle the uncertainties expressed as intervals and fuzzy sets. Moreover, the lower and upper bounds of RBI are continuous random variables, and the correlation existing between the lower and upper bounds can be tackled in RBI through the joint probability distribution function. And thus the subjectivity of decision making is greatly reduced, enhancing the stability and robustness of obtained solutions. The proposed method was then applied to solve a water and farmland use planning model (WFUPM) with non-point source pollution mitigation. The generated results could provide decision makers with detailed water supply-demand schemes involving diversified water-related activities under preferred satisfaction degrees. These useful solutions could allow more in-depth analyses of the trade-offs between humans and environment, as well as those between system optimality and reliability. In addition, comparative analyses on the solutions obtained from ICCP (Interval chance-constraints programming) and DIFSP demonstrated the higher application of this developed approach for supporting the water and farmland use system planning.

  11. 河流污染的点源和非点源负荷分割研究%The Segmentation of the Point Source and Non-point Source Pollution Load of Rivers

    Institute of Scientific and Technical Information of China (English)

    乔继平; 代俊峰

    2015-01-01

    Non-point source pollution has become the major source of pollution of water environment .Point source pollution and non-point source pollution of river water environmental monitoring to distinguish sections is very necessary .This paper mainly intro‐duces the research progress at home and abroad about non point source pollution .This paper focuses on the pollution load partition of Nanliu River Basin in Guangxi Beibu Gulf Economic Zone .The segmentation of point source pollution and non-point source pollution of potassium permanganate index ,total phosphorus and ammonia nitrogen are made based on the hydrological estimation method and the digital filtering method .The hydrological estimation method results show that three indexes of non-point source pollution the to‐tal pollution load ratio is 0 .77 ,0 .74 and 0 .76 .And the digital filtering method results show that they are 0 .59 ,0 .64 and 0 .66 .Di‐viding two methods of non-point source is close to the result ,Nanliu River Basin is more serious .%非点源污染已经成为水环境的主要污染源,区分河流水环境监测断面的点源污染与非点源污染显得十分必要。以广西入海河流南流江为研究背景,采用数字滤波法和水文估算法进行点源与非点源污染负荷的分割。分析结果显示,基于水文估算法计算的2003-2011年多年平均高锰酸盐指数、总磷、氨氮的非点源污染负荷占总负荷的比例分别为0.77、0.74、0.76;采用数字滤波法计算的2003-2011年多年平均高锰酸盐指数、总磷、氨氮的非点源污染负荷占总负荷的比例分别为0.59、0.64、0.66。结果表明,两种方法分割的非点源结果的变幅趋势相同,南流江的非点源污染在总污染负荷中的比例较高。

  12. Watershed delineation and nitrogen source analysis for Bayou ...

    Science.gov (United States)

    Nutrient pollution in stormwater runoff from urbanized areas contributes to water quality degradation in streams and receiving waterbodies. Agriculture, population growth, and industrial activities are significant sources of nitrogen inputs for surface waters. Increased nitrogen loading stimulates eutrophication through algal blooms, which leads to an overall decrease in drinking water and aquatic habitat quality. Bayou Chico, a highly urbanized watershed in the Pensacola Bay system in northwest Florida, is a nutrient-impaired waterbody under management to reduce bacteria and nutrient loadings, in accordance with the Florida Department of Environmental Protection’s (FDEP) Basin Management Action Plan. Best management practices and green infrastructure (GI) throughout Bayou Chico help reduce nitrogen inputs by retaining and filtering water. GI can function as a nitrogen sink by sorption or infiltration into soils, sequestration into plant material, and denitrification through microbial processes. However, a better understanding of the efficiency of these systems is needed to better inform management practices on future nitrogen reduction. This project will address two issues relating to the presence of nitrogen in the Bayou Chico watershed: 1) the identification of specific nitrogen sources within urbanized areas, and 2) the potential rates of nitrogen removal and sequestration from GI and nitrogen transport throughout the bayou. To accomplish these goals, nitr

  13. Agricultural Non-point Source Pollution and Countermeasures in Yunnan%云南省农业面源污染及防治对策

    Institute of Scientific and Technical Information of China (English)

    邱成

    2014-01-01

    云南省主要农业环境污染问题包括:化肥使用量不断增加;地膜使用量及其覆盖面积不断增加;农药使用量不断增加;畜禽粪便污染日益加重。分析了问题产生的原因,提出了防治农业污染的建议。%Environmental problems are emerging due to agricultural non -point source pollution in Yunnan.The most serious problems are as follows:an increasing usage of chemical fertilizers and plastics in farm field,a rising release of pesticide,and a growing amount of waste from livestock and poultry.Agricultural non-point sources in Yunnan were identified.Suggestions were put forward to control agricultural pollution.

  14. Assessment of Non-Point Source Total Phosphorus Pollution from Different Land Use and Soil Types in a Mid-High Latitude Region of China

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    2016-11-01

    Full Text Available The transport characteristics of phosphorus in soil and the assessment of its environmental risk have become hot topics in the environmental and agricultural fields. The Sanjiang Plain is an important grain production base in China, and it is characterised by serious land use change caused by large-scale agricultural exploitation. Agricultural inputs and tillage management have destroyed the soil nutrient balance formed over long-term conditions. There are few studies on non-point source phosphorus pollution in the Sanjiang Plain, which is the largest swampy low plain in a mid-high-latitude region in China. Most studies have focused on the water quality of rivers in marsh areas, or the export mechanism of phosphorus from specific land uses. They were conducted using experimental methods or empirical models, and need further development towards mechanism models and the macro-scale. The question is how to find a way to couple processes in phosphorus cycling and a distributed hydrological model considering local hydrological features. In this study, we report an attempt to use a distributed phosphorus transport model to analyse non-point source total phosphorus pollution from different land uses and soil types on the Sanjiang Plain. The total phosphorus concentration generally shows an annually increasing trend in the study area. The total phosphorus load intensity is heterogeneous in different land use types and different soil types. The average total phosphorus load intensity of different land use types can be ranked in descending order from paddy field, dry land, wetlands, grassland, and forestland. The average total phosphorus load intensity of different soil types can be ranked in descending order: paddy soil, bog soil, planosol, meadow soil, black soil, and dark brown earth. The dry land and paddy fields account for the majority of total phosphorus load in the study area. This is mainly caused by extensive use of phosphate fertilizer on the

  15. In-stream attenuation of nitrogen and phosphorus from major point source in large-scale watershed: mixed source and long-term variation

    Science.gov (United States)

    Chen, X.; Fulda, M.; Keller, A. A.

    2011-12-01

    Increased human activity in agriculture and industry has posed significant impact on natural water bodies and resulted in water quality deterioration. Agricultural non-point source pollution and urban point source discharge from municipal waste water treatment plant are the more recent concerns. Computer models are often used to help assess the fate and transport of pollutant, which involves complex interactions such as adsorption, biochemical reaction and plants uptake. However, it remains to be a challenge to assess the attenuation of total nitrogen and total phosphorus in large-scale watershed where there are significant difference in land use types and soil properties, especially when there are significant temporal variations through a long-term simulation. In this study, a large-scale watershed model in the Ohio River Basin was constructed considering a ten year simulation period. To assess the downstream impacts of increasing or decreasing nutrient loads, a hypothetical waste water treatment plant was added as the point source in different subwatersheds, monitoring the downstream effects. Five scenarios (100 kg/d Ammonia, 100 kg/d Nitrate, 100 kg/d Phosphate, mixed 100 kg/d Ammonia & 100 kg/d Phosphate and mixed 100 kg/d Nitrate & 100 kg/d Phosphate) were examined to assess the attenuation process throughout the 10-years simulation. In addition to significant differences in the attenuation in different subwatersheds, the various loads had complex interrelations. We also observed significant variations in attenuation for short-term simulation, while in long-term, the attenuation factors tended to be stabilized.

  16. Sources of baseflow for the Minnehaha Creek Watershed, Minnesota, US

    Science.gov (United States)

    Nieber, J. L.; Moore, T. L.; Gulliver, J. S.; Magner, J. A.; Lahti, L. B.

    2013-12-01

    Minnehaha Creek is among the most valued surface water features in the Minneapolis, MN metro area, with a waterfall as it enters the Minnehaha Creek park. Flow in Minnehaha Creek is heavily dependent on discharge from the stream's origin, Lake Minnetonka, the outlet of which is closed during drought periods to maintain water elevations in the lake resulting in low- (or no-) flow conditions in the creek. Stormwater runoff entering directly to the creek from the creek's largely urbanized watershed exacerbates extremes in flow conditions. Given the cultural and ecological value of this stream system, there is great interest in enhancing the cultural and ecosystem services provided by Minnehaha Creek through improvements in streamflow regime by reducing flashiness and sustaining increased low-flows. Determining the potential for achieving improvements in flow requires first that the current sources of water contributing to low-flows in the creek be identified and quantified. Work on this source identification has involved a number of different approaches, including analyses of the streamflow record using a hydrologic system model framework, examination of the Quaternary and bedrock geology of the region, estimation of groundwater-surface water exchange rates within the channel using hyporheic zone temperature surveys and flux meter measurements, and analyses of the stable isotopes of oxygen and hydrogen in samples of stream water, groundwater, and rainfall. Analysis of baseflow recessions using the method of Brutsaert and Nieber (1977) indicates that only a small portion of the catchment, probably the riparian zone, contributes to baseflows. This result appears to be supported by the observation that the limestone/shale bedrock layer underlying the surficial aquifer has a non-zero permeability, and in a significant portion of the watershed the layer has been eroded away leaving the surficial aquifer ';bottomless' and highly susceptible to vertical (down) water loss

  17. Combination system of full-scale constructed wetlands and wetland paddy fields to remove nitrogen and phosphorus from rural unregulated non-point sources.

    Science.gov (United States)

    Sun, Haijun; Zhang, Hailin; Yu, Zhimin; Wu, Jiasen; Jiang, Peikun; Yuan, Xiaoyan; Shi, Weiming

    2013-12-01

    Constructed wetlands (CWs) have been used effectively to remove nitrogen (N) and phosphorus (P) from non-point sources. Effluents of some CWs were, however, still with high N and P concentrations and remained to be pollution sources. Widely distributed paddy fields can be exploited to alleviate this concern. We were the first to investigate a combination system of three-level CWs with wetland paddy fields in a full scale to remove N and P from rural unregulated non-point sources. The removal efficiencies (REs) of CWs reached 57.3 % (37.4-75.1 %) for N and 76.3 % (62.0-98.4 %) for P. The CWs retained about 1,278 kg N ha(-1) year(-1) and 121 kg P ha(-1) year(-1). There was a notable seasonal change in REs of N and P, and the REs were different in different processing components of CWs. The removal rates of wetland paddy fields adopt "zero-drainage" water management according to local rainfall forecast and physiological water demand of crop growth reached 93.2 kg N ha(-1) year(-1) and 5.4 kg P ha(-1) year(-1). The rice season had higher potential in removing N and P than that in the wheat season. The whole combined system (0.56 ha CWs and 5.5 ha wetland paddy fields) removed 1,790 kg N year(-1) and 151 kg P year(-1), which were higher than those from CWs functioned alone. However, another 4.7-ha paddy fields were needed to fully remove the N and P in the effluents of CWs. The combination of CWs and paddy fields proved to be a more efficient nutrient removal system.

  18. Environmental Kuznets Curve Analysis of the Economic Development and Nonpoint Source Pollution in the Ningxia Yellow River Irrigation Districts in China

    Directory of Open Access Journals (Sweden)

    Chunlan Mao

    2013-01-01

    Full Text Available This study applies the environmental Kuznets curve to test the relationship between the regional economic growth and the different types of agricultural nonpoint source pollution loads in the Ningxia Yellow River irrigation area by using the Johnes export coefficient method. Results show that the pollution load generated by crop cultivation and livestock-breeding industries in the Ningxia Yellow River irrigation area shows an inverted U-shaped feature; however, this feature is absent in living-sewage pollution load. Crop pollution has shown a decreasing trend since 1997 because of the increased per capita income of farmers. Livestock-breeding pollution load reached its turning point when the per capita income of farmers reached 8386.74 RMB. Therefore, an increase in the per capita income of farmers corresponds to an increase in the livestock-breeding pollution load in the Ningxia Yellow River irrigation area.

  19. Environmental Kuznets curve analysis of the economic development and nonpoint source pollution in the Ningxia Yellow River irrigation districts in China.

    Science.gov (United States)

    Mao, Chunlan; Zhai, Ningning; Yang, Jingchao; Feng, Yongzhong; Cao, Yanchun; Han, Xinhui; Ren, Guangxin; Yang, Gaihe; Meng, Qing-xiang

    2013-01-01

    This study applies the environmental Kuznets curve to test the relationship between the regional economic growth and the different types of agricultural nonpoint source pollution loads in the Ningxia Yellow River irrigation area by using the Johnes export coefficient method. Results show that the pollution load generated by crop cultivation and livestock-breeding industries in the Ningxia Yellow River irrigation area shows an inverted U-shaped feature; however, this feature is absent in living-sewage pollution load. Crop pollution has shown a decreasing trend since 1997 because of the increased per capita income of farmers. Livestock-breeding pollution load reached its turning point when the per capita income of farmers reached 8386.74 RMB. Therefore, an increase in the per capita income of farmers corresponds to an increase in the livestock-breeding pollution load in the Ningxia Yellow River irrigation area.

  20. Linking monitoring and modelling for river basin management:Danish experience with combating nutrient loadings to the aquatic environment from point and non-point sources

    Institute of Scientific and Technical Information of China (English)

    KRONVANG; Brian; WINDOLF; JФrgen; GRANT; Ruth; ANDERSEN; Hans; E; THODSEN; Hans; OVESEN; Niels; B; LARSEN; SФren; E

    2009-01-01

    Nationwide monitoring of the aquatic environment was initiated in 1988 in Denmark as a means to follow the outcome of the Action Plans for nutrient pollution of the aquatic environment. Five Action Plans have been adopted by the Danish Parliament since 1985 and the nationwide monitoring programme can be used to quantify the outcome as shown by reductions in nutrient discharges from both point and non-point sources. Moreover, the empirical experience gathered from nearly 20 years of monitoring is assisting the development and calibration of models for simulation of nitrogen leaching, nitrogen removal in groundwater and surface waters and the establishment of a P-index all covering the entire land area of Denmark.

  1. Linking monitoring and modelling for river basin man-agement: Danish experience with combating nutrient loadings to the aquatic environment from point and non-point sources

    Institute of Scientific and Technical Information of China (English)

    KRONVANG Brian; WINDOLF J(φ)rgen; GRANT Ruth; ANDERSEN Hans E; THODSEN Hans; OVESEN Niels B; LARSEN S(φ)ren E

    2009-01-01

    Nationwide monitoring of the aquatic environment was initiated in 1988 in Denmark as a means to fol-low the outcome of the Action Plans for nutrient pollution of the aquatic environment.Five Action Plans have been adopted by the Danish Parliament since 1985 and the nationwide monitoring programme can be used to quantify the outcome as shown by reductions in nutrient discharges from both point and non-point sources.Moreover, the empirical experience gathered from nearly 20 years of monitoring is assisting the development and calibration of models for simulation of nitrogen leaching, nitrogen re-moval in groundwater and surface waters and the establishment of a P-index all covering the entire land area of Denmark.

  2. Environmental Kuznets Curve Analysis of the Economic Development and Nonpoint Source Pollution in the Ningxia Yellow River Irrigation Districts in China

    Science.gov (United States)

    Mao, Chunlan; Zhai, Ningning; Yang, Jingchao; Feng, Yongzhong; Cao, Yanchun; Han, Xinhui; Ren, Guangxin; Yang, Gaihe; Meng, Qing-xiang

    2013-01-01

    This study applies the environmental Kuznets curve to test the relationship between the regional economic growth and the different types of agricultural nonpoint source pollution loads in the Ningxia Yellow River irrigation area by using the Johnes export coefficient method. Results show that the pollution load generated by crop cultivation and livestock-breeding industries in the Ningxia Yellow River irrigation area shows an inverted U-shaped feature; however, this feature is absent in living-sewage pollution load. Crop pollution has shown a decreasing trend since 1997 because of the increased per capita income of farmers. Livestock-breeding pollution load reached its turning point when the per capita income of farmers reached 8386.74 RMB. Therefore, an increase in the per capita income of farmers corresponds to an increase in the livestock-breeding pollution load in the Ningxia Yellow River irrigation area. PMID:24171160

  3. Mapping sediment sources in a New Zealand Mountain Watershed

    Science.gov (United States)

    Mosley, M. Paul

    1980-03-01

    Planning of soil conservation and erosion control schemes to minimize downstream effects requires information on the sources of sediment supply to a river system. A survey technique for providing an inventory of sediment sources has been developed in New Zealand; sediment sources are classified in terms of geomorphic type and degree of activity (severity). The technique is qualitative but is of value for both planning and research because it demands a formal, objective examination of the area under study. In the Harper-Avoca watershed the technique demonstrated that some well-established beliefs regarding the supply of sediment to the river systems might be erroneous; sediment supply appears to be controlled primarily by geomorphic and geologic factors, and human interference with the ecosystem probably has had a minor effect on rates of supply. The bulk of the sediment comes from large, natural features that are beyond present erosion-control technology, whereas those features that could be effectively treated supply a relatively small proportion of the river's total sediment load.

  4. Fecal Contamination in the Surface Waters of a Rural- and an Urban-Source Watershed

    DEFF Research Database (Denmark)

    Stea, Emma C.; Hansen, Lisbeth Truelstrup; Jamieson, Rob C.

    2015-01-01

    Surface waters are commonly used as source water for drinking water and irrigation. Knowledge of sources of fecal pollution in source watersheds benefits the design of effective source water protection plans. This study analyzed the relationships between enteric pathogens (Escherichia coli O157:H...... and fecal marker concentrations in the waterways. The employment of multiple FST methods suggested failing onsite wastewater systems contribute to human fecal pollution in both watersheds....

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

    Science.gov (United States)

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

    2012-02-01

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

  6. Yield calculation of agricultural non-point source pollutants in Huntai River Basin based on SWAT model%基于SWAT模型的浑太河流域农业面源污染物产生量估算

    Institute of Scientific and Technical Information of China (English)

    付意成; 臧文斌; 董飞; 付敏; 张剑

    2016-01-01

    The establishment of non-point source pollutants output load model under the mode of rainfall-runoff and land use, the analog calculation of agricultural non-point source pollutants in the process of migration and transformation, and the systematic analysis of non-point source pollutants discharge quantity, distribution and composition characteristics are based on actual monitoring data, calibration and validation model, in consideration of underlying surface, hydrology and meteorology, and physical features of Huntai River basin. The areas 1 km away from each side of master stream Huntai River, Taizihe River and Daliaohe River and 5 km away from reservoir were defined as buffer zone, where the mode of land use was transformed so as to restore the natural ecosystem. The process of pollutant migration and conversion was simulated based on the calibration of key hydrological parameters, and the causes as well as the migratory features of non-point source pollution were investigated. The primary area of water environment pollution was mainly distributed along both sides of the water channel of the mainstreams of Huntai River. The point-source pollutant was mainly related to the distribution of industry and the amount of discharged wastewater. The risk of non-point pollution was mainly related to the pattern of agricultural plantation and farmland utilization. The secondary area of water environment pollution was mainly distributed along both sides of the water channel of tributaries. Therefore, the situation of pollutant production corresponding to the intra-regional regulation of industrial structure, land utilization pattern surrounding the water channel should be highlighted. The non-point pollution in Huntai watershed was dominated by farmland pollution, and the main indices of pollutants were total nitrogen (N) and total phosphorus (P). The contribution rate of pollutants was farmland runoff > livestock and poultry breeding > urban runoff > water and soil erosion

  7. An assessment of forest cover and impervious surface area on family forests in the New York City Watershed

    Science.gov (United States)

    Nathaniel M. Anderson; Rene H. Germain; Myrna H. Hall

    2012-01-01

    Between 1984 and 2000, the parcelization of family forests in the New York City Watershed caused a decline in average parcel size from 19 to 16 ac. However, little is known about the timing and intensity of development on subdivided parcels, which has the potential to negatively affect water quality by increasing nonpoint source pollution associated with nutrient...

  8. WA - Impacts of non-point source pollution on the health of salmonids in urban and urbanizing watersheds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — By the Services conducting this off-refuge EC investigation and jointly publishing the results in the two aforementioned manuscripts [see notes section of ProCite...

  9. Evaluating Urbanization Impacts from Non-Point Stormwater Runoff using Geospatial Analysis

    Science.gov (United States)

    Zivkovich, B. R.; Mays, D. C.

    2015-12-01

    Sediments, nutrients and other chemical impairments caused by urbanization continue to deteriorate natural ecosystem processes, resulting in the current degraded state of urban surface waters. Understanding non-point source impacts on these natural ecosystems has become a prevalent topic in sustainable urban infrastructure design as efforts to restore the urban hydrologic regime continue to drive engineers, planners, and environmentalists to develop optimal design practices for rapidly expanding built environments. To best understand how and where these impairments are received, the U.S. Environmental Protection Agency and other organizations have adopted urban runoff programs to identify contributions from non-point sources. This presentation provides a geospatial analysis method for identifying non-point source watersheds, and associated sub-basins, that contribute the highest loads of pollutants to receiving urban streams and lakes. This method, using a form of linear matrix inversion, is an area-averaged weighting method for non-point pollutants that corresponds to a geospatial land cover analysis. This two-phase analysis can be used to aid all parties in understanding how different land use types affect urban stream systems and processes. Optimal locations for water quality features (i.e., best management practices) can be evaluated in order to reduce, capture, and treat stormwater runoff as close to the source as possible. These best management practices have the ability to operate most effectively when located properly, because their ability to act as a minor treatment and prevention system is of great important for the restoration of the urban hydrologic regime.

  10. Spatial Distribution Pattern of Agricultural Non-point Source Pollution in Jiangxi Province%江西省农业面源污染空间分布格局

    Institute of Scientific and Technical Information of China (English)

    张文东; 许仕; 庐俊

    2012-01-01

    The agricultural non-point source pollution is becoming an increasingly important eco-envjonrmental problem, il is difficult lo control due lo its dispersive and extensive characteristics. Jiangxi Province is still at ihe initial stage ai agricultural modernization, bul its agricultural non-point source pollution is exacerbating. According to the investigation on the pollution sources of planting, animal husbandry and aq-uaculture in Jiangs i Province, the ArcGIS software was adopted to analyze the spatial and digital features of agricultural non-point source pollution. As indicated by the results, the principal pollution source is animal husbandry, then followed by planting, ihe pollution from aquarulture is becoming more and more serious. The study provided scientific basis for the evaluation of agricultural non-point source pollution in Jiangxi Province.%农业面源污染正成为生态环境的主要问题,但其分散性、广泛性等特点又决定了其治理难度较大.江西目前仍处于农业现代化的起点阶段,农业面源污染日益严重:该研究通过对江西省农业的种植业、畜禽业和水产养殖业的污染源进行调查,利用ArcGIS软件,对江西省农业面源污染进行了空间化和数字化处理.结果表明,江西省农业污染源主要是畜禽养殖业,其次是种植业,水产养殖业污染日趋严重.该研究为江西省农业面源污染评估提供了科学依据.

  11. Past leaded gasoline emissions as a nonpoint source tracer in riparian systems: A study of river inputs to San Francisco Bay

    Science.gov (United States)

    Dunlap, C.E.; Bouse, R.; Flegal, A.R.

    2000-01-01

    Variations in the isotopic composition of lead in 1995-1998 river waters flowing into San Francisco Bay trace the washout of lead deposited in the drainage basin from leaded gasoline combustion. At the confluence of the Sacramento and San Joaquin rivers where they enter the Bay, the isotopic compositions of lead in the waters define a linear trend away from the measured historical compositions of leaded gas in California. The river waters are shifted away from leaded gasoline values and toward an isotopic composition similar to Sierra Nevadan inputs which became the predominant source of sedimentation in San Francisco Bay following the onset of hydraulic gold mining in 1853. Using lead isotopic compositions of hydraulic mine sediments and average leaded gasoline as mixing end members, we calculate that more than 50% of the lead in the present river water originated from leaded gasoline combustion. The strong adsorption of lead (log K(d) > 7.4) to particulates appears to limit the flushing of gasoline lead from the drainage basin, and the removal of that lead from the system may have reached an asymptotic limit. Consequently, gasoline lead isotopes should prove to be a useful nonpoint source tracer of the environmental distribution of particle- reactive anthropogenic metals in freshwater systems.

  12. Spatial-temporal characteristics of phosphorus in non-point source pollution with grid-based export coefficient model and geographical information system.

    Science.gov (United States)

    Liu, Ruimin; Dong, Guangxia; Xu, Fei; Wang, Xiujuan; He, Mengchang

    2015-01-01

    In this paper, the spatial changes and trends in non-point source (NPS) total phosphorus (TP) pollution were analyzed by land and non-land uses in the Songliao River Basin from 1986 to 2000 (14 years). A grid-based export coefficient model was used in the process of analysis based on to a geographic information system. The Songliao Basin is divided in four regions: Liaoning province, Jilin province (JL), Heilongjiang province and the eastern part of the Inner Mongolia (IM) Autonomous Region. Results indicated that the NPS phosphorus load caused by land use and non-land use increased steadily from 3.11×10(4) tons in 1986 to 3.49×10(4) tons in 2000. The southeastern region of the Songliao Plain was the most important NPS pollution contributor of all the districts. Although the TP load caused by land use decreased during the studied period in the Songliao River Basin, the contribution of land use to the TP load was dominant compared to non-land uses. The NPS pollution caused by non-land use steadily increased over the studied period. The IM Autonomous Region and JL province had the largest mean annual rate of change among all districts (more than 30%). In this area, livestock and poultry breeding had become one of the most important NPS pollution sources. These areas will need close attention in the future.

  13. Diagnostic Systems Approach to Watershed Management

    Energy Technology Data Exchange (ETDEWEB)

    Davisson, M L

    2001-02-23

    The water quality of discharge from the surface water system is ultimately dictated by land use and climate within the watershed. Water quality has vastly improved from point source reduction measures, yet, non-point source pollutants continue to rise. 30 to 40% of rivers still do not meet water quality standards for reasons that include impact from urban storm water runoff, agricultural and livestock runoff, and loss of wetlands. Regulating non-point source pollutants proves to be difficult since specific dischargers are difficult to identify. However, parameters such as dissolved organic carbon (DOC) limit the amounts of chlorination due to simultaneous disinfection by-product formation. The concept of watershed management has gained much ground over the years as a means to resolve non-point source problems. Under this management scheme stakeholders in a watershed collectively agree to the nature and extent of non-point sources, determine water quality causes using sound scientific approaches, and together develop and implement a corrective plan. However, the ''science'' of watershed management currently has several shortcomings according to a recent National Research Council report. The scientific component of watershed management depends on acquiring knowledge that links water quality sources with geographic regions. However, there is an observational gap in this knowledge. In particular, almost all the water quality data that exists at a utility are of high frequency collected at a single point over a long period of time. Water quality data for utility purposes are rarely collected over an entire watershed. The potential is high, however, for various utilities in a single watershed to share and integrate water quality data, but no regulatory incentives exist at this point. The only other available water quality data originate from special scientific studies. Unfortunately these data rarely have long-term records and are usually tailored to

  14. 苏州市农业面源污染现状与控制研究%Current situation and control recommendations of agricultural non-point source pollution in Suzhou City

    Institute of Scientific and Technical Information of China (English)

    张贵龙; 秦伟; 管永祥; 邱丹; 杨殿林; 赵建宁

    2011-01-01

    Based on the results of national survey of pollution sources, the production and emission characteristics of pollutants from agricultural activities and the major control measures of agricultural non-point source pollution in Suzhou along the Yangtze River, Taihu Lake and Yangchenghu Lake were analyzed and demonstrated. The results showed that among the non-point source pollutants, the totalamount of nitrogen and phosphorus emitted were 11 878.9 and 1 343.8 t respectively, pesticides loss was 28.0 t, plastic membrane residual was 203.9 t, the volume of straw burned was 214 000 t, total amount of COD emitted by livestock breeding, aquaculture and rural community was 92 360.3 t; The emission amount of nitrogen and phosphorus along the Yangtze River was the largest followed by Taihu Lake, along the Yangcbenghu Lake the lowest. According to the analysis of the total amount of N and P emitted, the ranking of pollutant resource was as below: rural community > livestock breeding >aquaculture > planting; The pollution intensity caused by the four sources were different. The three watershed, the pollution intensity of farming, animal husbandry and rural communities was greater in the Yangtze River, but the pollution intensity of aquaculture was greater in Taihu Lake Therefore,in guiding concept for the prevention and control of no point source pollution, the government should pay close attention to the Yangtze River, give more weight to domestic pollution sources. In view of the above -mentioned facts,to control agricultural non-point source pollution. Some proposals were offered as follows, concentrating superior resources to dispose rural sewage, optimizing the agricultural industry structure, strengthening the ecological construction, comprehensively treating livestock pollution, promoting the utilization of crop straw resources,and reasonably planning aquaculture etc.%利用提供的区城产排污系数,对苏州市沿长江、太湖和阳澄湖流域农业面

  15. Status of Agricultural Non-point Source Pollu-tion in China and Com-prehensive Treatment%我国农业面源污染现状及综合治理

    Institute of Scientific and Technical Information of China (English)

    李晓俐

    2015-01-01

    Agricultural non-point source pollution is worsening in China, mainly due to excessive and irrational use of pesticides, excessive use of fertil-izers, plastic sheeting pollution, straw pollution, intensive breeding farms pol-lution,etc. Agricultural non-point source pollution is harmful to water, atmosphere and soil,so the comprehensive treatment measures were put forward.%我国农业面源污染日益严重,主要原因是过量且不合理地使用农药,过量使用化肥,农膜污染、秸秆污染、集约化养殖场污染等。农业面源污染对水体、大气、土壤等造成严重危害,故提出综合治理措施。

  16. Nitrogen Non-Point Source Pollution Identification Based on ArcSWAT in Changle River%基于ArcSWAT模型的长乐江流域非点源氮素污染源识别和分析

    Institute of Scientific and Technical Information of China (English)

    邓欧平; 孙嗣旸; 吕军

    2013-01-01

    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.%本研究以我国东南沿海地区的典型农业流域——长乐江流域为对象,通过实地调查、数据收集和分析,

  17. 缓冲带在农业面源污染防治上的应用%Study on pollution control of agricultural nonpoint source by means of buffer strips

    Institute of Scientific and Technical Information of China (English)

    杨帆; 刘赢男; 焉志远; 黎叩晨; 倪红伟

    2015-01-01

    Agricultural nonpoint source pollution has become one of the m ost important threats to water environment safety. To ensure security of water environment, it is necessary to prevent and control agricultural non-point source pollution. Riparian buffer zone, which could effectively prevent and control agricultural non-point source pollution, has been widely recognized, and it also has a certain application on the source of water prevention. Based on the introduction of definition of buffer zone, structure of macro and microscopic, mechanism of nitrogen and phosphorus losing and research of different countries and regions of agricultural non-point pollution, the protection of riparian buffer strips in the water environment was proposed.%农业面源污染已经成为威胁水环境安全的一个重要因素,为了保证水质安全,对进入水体的农业面源污染进行防治是十分必要的。缓冲带在防治农业面源污染上的功效已经得到了广泛的认可,并在水污染治理上有一定的应用前景。通过对缓冲带的定义、宏观和微观结构、氮磷元素流失机理以及不同国家和地区应用缓冲带去除农业面源污染方面的研究,提出了我国缓冲带在水环境保护中的应用前景。

  18. Relations of nonpoint-source nitrate and atrazine concentrations in the High Plains aquifer to selected explanatory variables in six Nebraska study areas

    Science.gov (United States)

    Druliner, A.D.; Chen, H.H.; McGrath, T.S.

    1996-01-01

    Statistical techniques were used to relate nonpoint-source ground-water contamination by nitrate and atrazine to a variety of explanatory variables for six study areas in Nebraska. Water samples were collected from 268 wells in 12 counties from 1984 through 1987 and were analyzed for nitrate concentrations; water samples from 210 of the wells were analyzed for atrazine. A number of hydrochemical, climatic, hydrologic, soil, and land-use explanatory variables, which were believed to affect the contamination of ground water by agricultural chemicals, were identified and quantified for each of the 268 wells. Multiple regression methods were used to determine which explanatory variables were statistically related to ground-water concentrations of nitrate and atrazine. Regression models predicting nitrate and atrazine concentrations were produced that explained from about 50 to 68 percent of the variation in the dependent variables. Geographic- information-system methods were used to produce maps predicting nitrate and atrazine concentrations in ground water for one study area using selected regression and logistic models. The results of this study indicate that multiple regression techniques coupled with geographic information systems can be an effective means of identifying areas of potential ground-water contamination by nitrate and atrazine.

  19. Using SWAT to Assess the Critical Areas and Nonpoint Source Pollution Reduction Best Management Practices in Lam Takong River Basin, Thailand

    Directory of Open Access Journals (Sweden)

    Netnapa Pongpetch

    2015-01-01

    Full Text Available Hydrological models are essential tools for water resource and nonpoint source pollution management. This study aimed to evaluate critical areas and best management practices (BMPs of sediment and nutrient loads in Lam Takong River basin, Northeastern Thailand, using SWAT (Soil and Water Assessment Tool model. The model was calibrated and validated using daily data of streamflow, sediment, NO3-N and TP in Lam Takong River from 2007-2008 and 2009, respectively. In general, the simulated streamflow and sediment were in reasonable agreement with the measured values with coefficient of determination (R2 and Nash-Sutcliffe model efficiency coefficient (NSE greater than 0.50 and the percent bias (PBIAS less than 25%. Additionally, nutrient loads showed a fair relationship between observation and simulation with R2 values more than 0.6 and PBIAS values less than 25%. From simulation, September was the month with the highest sediment, NO3-N and TP yields while January and December were the lowest months. From the model, SWAT identified 1 severe and 1 high soil erosion subbasins. Two subbasins were classified into medium loading for NO3-N. However, 9 subbasins were classified into high loading rate of TP. For BMPs, the 30-mwide filter strip was the best scenario reducing 100% of both sediment and TP, and 97.27% of NO3-N. These results could be a useful tool for water resources managements and soil conservation planning in Lam Takong River basin.

  20. Using a constructed wetland for non-point source pollution control and river water quality purification: a case study in Taiwan.

    Science.gov (United States)

    Wu, C Y; Kao, C M; Lin, C E; Chen, C W; Lai, Y C

    2010-01-01

    The Kaoping River Rail Bridge Constructed Wetland, which was commissioned in 2004, is one of the largest constructed wetlands in Taiwan. This multi-function wetland has been designed for the purposes of non-point source (NPS) pollutant removal, wastewater treatment, wildlife habitat, recreation, and education. The major influents of this wetland came from the local drainage trench containing domestic, agricultural, and industrial wastewaters, and effluents from the wastewater treatment plant of a paper mill. Based on the quarterly investigation results from 2007 to 2009, more than 96% of total coliforms (TC), 48% of biochemical oxygen demand (BOD), and 40% of nutrients (e.g. total nitrogen, total phosphorus) were removed via the constructed wetland system. Thus, the wetland system has a significant effect on water quality improvement and is capable of removing most of the pollutants from the local drainage system before they are discharged into the downgradient water body. Other accomplishments of this constructed wetland system include the following: providing more green areas along the riversides, offering more water assessable eco-ponds and eco-gardens for the public, and rehabilitating the natural ecosystem. The Kaoping River Rail Bridge Constructed Wetland has become one of the most successful multi-function constructed wetlands in Taiwan. The experience obtained from this study will be helpful in designing similar natural treatment systems for river water quality improvement and wastewater treatment.

  1. Evaluating the Effects of Land Use Planning for Non-Point Source Pollution Based on a System Dynamics Approach in China.

    Science.gov (United States)

    Kuai, Peng; Li, Wei; Liu, Nianfeng

    2015-01-01

    Urbanization is proceeding rapidly in several developing countries such as China. This accelerating urbanization alters the existing land use types in a way that results in more Non-Point Source (NPS) pollution to local surface waters. Reasonable land use planning is necessary. This paper compares seven planning scenarios of a case study area, namely Wulijie, China, from the perspective of NPS pollution. A System Dynamics (SD) model was built for the comparison to adequately capture the planning complexity. These planning scenarios, which were developed by combining different land use intensities (LUIs) and construction speeds (CSs), were then simulated. The results show that compared to scenario S1 (business as usual) all other scenarios will introduce more NPS pollution (with an incremental rate of 22%-70%) to Wulijie. Scenario S6 was selected as the best because it induced relatively less NPS pollution while simultaneously maintaining a considerable development rate. Although LUIs represent a more critical factor compared to CSs, we conclude that both LUIs and CSs need to be taken into account to make the planning more environmentally friendly. Considering the power of SD in decision support, it is recommended that land use planning should take into consideration findings acquired from SD simulations.

  2. Comparative study on nutrient removal of agricultural non-point source pollution for three filter media filling schemes in eco-soil reactors.

    Science.gov (United States)

    Du, Fuyi; Xie, Qingjie; Fang, Longxiang; Su, Hang

    2016-08-01

    Nutrients (nitrogen and phosphorus) from agricultural non-point source (NPS) pollution have been increasingly recognized as a major contributor to the deterioration of water quality in recent years. The purpose of this article is to investigate the discrepancies in interception of nutrients in agricultural NPS pollution for eco-soil reactors using different filling schemes. Parallel eco-soil reactors of laboratory scale were created and filled with filter media, such as grit, zeolite, limestone, and gravel. Three filling schemes were adopted: increasing-sized filling (I-filling), decreasing-sized filling (D-filling), and blend-sized filling (B-filling). The systems were intermittent operations via simulated rainstorm runoff. The nutrient removal efficiency, biomass accumulation and vertical dissolved oxygen (DO) distribution were defined to assess the performance of eco-soil. The results showed that B-filling reactor presented an ideal DO for partial nitrification-denitrification across the eco-soil, and B-filling was the most stable in the change of bio-film accumulation trends with depth in the three fillings. Simultaneous and highest removals of NH4(+)-N (57.74-70.52%), total nitrogen (43.69-54.50%), and total phosphorus (42.50-55.00%) were obtained in the B-filling, demonstrating the efficiency of the blend filling schemes of eco-soil for oxygen transfer and biomass accumulation to cope with agricultural NPS pollution.

  3. Sensitivity analysis of non-point sources in a water quality model applied to a dammed low-flow-reach river.

    Science.gov (United States)

    Silva, Nayana G M; von Sperling, Marcos

    2008-01-01

    Downstream of Capim Branco I hydroelectric dam (Minas Gerais state, Brazil), there is the need of keeping a minimum flow of 7 m3/s. This low flow reach (LFR) has a length of 9 km. In order to raise the water level in the low flow reach, the construction of intermediate dikes along the river bed was decided. The LFR has a tributary that receives the discharge of treated wastewater. As part of this study, water quality of the low-flow reach was modelled, in order to gain insight into its possible behaviour under different scenarios (without and with intermediate dikes). QUAL2E equations were implemented in FORTRAN code. The model takes into account point-source pollution and diffuse pollution. Uncertainty analysis was performed, presenting probabilistic results and allowing identification of the more important coefficients in the LFR water-quality model. The simulated results indicate, in general, very good conditions for most of the water quality parameters The variables of more influence found in the sensitivity analysis were the conversion coefficients (without and with dikes), the initial conditions in the reach (without dikes), the non-point incremental contributions (without dikes) and the hydraulic characteristics of the reach (with dikes).

  4. [Ecosystem service and economic valuation in the upper reaches of Xin' an River, Anhui, China for mitigating phosphorus nonpoint source pollution].

    Science.gov (United States)

    He, Fang; Wu, Nan; Fang, Xiang-long; Gao, Ji-xi; Zhou, Xiao-tie; Feng, Chao-yang

    2015-04-01

    A model of phosphorus purification in a watershed was established based on the export coefficient and purification index of phosphorus in different types of land cover. The model was employed to simulate the economic value of the ecosystem service with the expected water quality standard and marginal cost of pollutant purification of the upper reaches of Xin' an River of Anhui, China. The results revealed that from 2000 to 2010, some farmland outside the Tunxi, Jixi, Shexian, Yixian and Xiuning was converted to built-up land. The total amount of phosphorus exported to the upper Xin' an River decreased a little, and the main source of phosphorus pollution was farmland and built-up land. More than half of the exported phosphorus was efficiently purified by different types of land cover via flow accumulation. The pattern of purification and export of highly concentrated phosphorus showed the same trend which occurred in the northern part of the watershed including the Yangzhi River, Fengle River and Hengjiang River. Forestland and grassland did not efficiently purify phosphorus in the watershed owing to the irrational distribution of existing land cover. The total service value was 3.80 and 3.31 million Yuan in 2000 and 2010, respectively.

  5. 基于农业面源污染控制的三峡库区种植业结构优化%Planting structure optimization based on agricultural non-point source pollution control in Three Gorges Reservoir Region

    Institute of Scientific and Technical Information of China (English)

    肖新成; 谢德体; 何丙辉; 魏朝富; 倪九派

    2014-01-01

    Agricultural non-point source pollution has gradually become a major pollution source of lake eutrophication and deterioration of water quality in recent years. The Three Gorges Reservoir Region is both an important sensitive eco-economy area and a typical poverty-stricken mountain area. However, its unique geographical location, its irrational agricultural structure and its increasing serious agricultural non-point source pollution problems challenge the environment in this region. Hence, it is a necessity to take controlling agricultural non-point source pollution from the source as one of the most effective approaches. In current research, agricultural non-point source pollution control excessively depends on engineering and technology. Anyhow, the roles of agricultural planting structure adjustment and agricultural cleaner production which can reduce non-point source pollution should not be ignored. Promoting the adjustment of planting structure, reducing the use of chemical fertilizers and pesticides, and adopting agricultural cleaner production technologies not only help improve the land production capacity and agricultural products quality, but also effectively reduce the agricultural non-point source pollution. By these important measures for energy saving and emission reduction can be realized in Three Gorges Reservoir Region. Based on the dual goals of the optimal agricultural economic benefits and non-point source pollution emission reduction, the linear programming model was used to optimize the planting structure and clean agricultural production in the Three Gorges Reservoir Region. The optimization results showed that the optimal paths to maximize the crop net income were as follows: The land area for grain production should cover 119.16×104hm2but cleaner production area of rice-wheat, corn, soybean and tuber crops needs 31.91×104, 18.69×104, 6.79×104and 19.55×104 hm2; the land area for vegetables planting should be 33.25×104hm2 and its cleaner

  6. Non-Point Source Pollutant Load Variation in Rapid Urbanization Areas by Remote Sensing, Gis and the L-THIA Model: A Case in Bao'an District, Shenzhen, China

    Science.gov (United States)

    Li, Tianhong; Bai, Fengjiao; Han, Peng; Zhang, Yuanyan

    2016-11-01

    Urban sprawl is a major driving force that alters local and regional hydrology and increases non-point source pollution. Using the Bao'an District in Shenzhen, China, a typical rapid urbanization area, as the study area and land-use change maps from 1988 to 2014 that were obtained by remote sensing, the contributions of different land-use types to NPS pollutant production were assessed with a localized long-term hydrologic impact assessment (L-THIA) model. The results show that the non-point source pollution load changed significantly both in terms of magnitude and spatial distribution. The loads of chemical oxygen demand, total suspended substances, total nitrogen and total phosphorus were affected by the interactions between event mean concentration and the magnitude of changes in land-use acreages and the spatial distribution. From 1988 to 2014, the loads of chemical oxygen demand, suspended substances and total phosphorus showed clearly increasing trends with rates of 132.48 %, 32.52 % and 38.76 %, respectively, while the load of total nitrogen decreased by 71.52 %. The immigrant population ratio was selected as an indicator to represent the level of rapid urbanization and industrialization in the study area, and a comparison analysis of the indicator with the four non-point source loads demonstrated that the chemical oxygen demand, total phosphorus and total nitrogen loads are linearly related to the immigrant population ratio. The results provide useful information for environmental improvement and city management in the study area.

  7. [Nonpoint pollution control for rural areas of China with ecological engineering technologies].

    Science.gov (United States)

    Yin, Chengqing; Mao, Zhanpo

    2002-02-01

    Nonpoint pollution from rural areas is the results of the ecosystem degradation, and ecological engineering technologies are good ways for the restoration of watershed and enhancing material cycling. There are two types of treatment strategies: to control the polluted runoff and to reduce the pollutants from the sources. Six control technologies are introduced and they are multipond systems, grassed filter trips, wetland systems, eco-agriculture, slope ecological engineering, ecological treatment of wastewater and solid waste. These technologies need to be combined systematically in order to form a watershed ecological engineering. In the control program, it is important to use countermeasure suitable to the local conditions. In addition, the input of sufficient investment, management and education is necessary.

  8. A Study on sediment sources in a small watershed by using REE tracer method

    Institute of Scientific and Technical Information of China (English)

    石辉; 田均良; 刘普灵; 周佩华

    1997-01-01

    In simulation experiments, rare earth element (REE) tracer method was first used to sludy the sources of sediment yield in a small watershed. The experimental results have shown that the chief parts of sediment sources are constantly changing with the development of gullies. The cutting erosion plays a major role in the primary stage of watershed development. Slope erosion intensity increased gradually with gully development of the watershed, while gully erosion intensity decreased. Similar process was also observed in an individual rainfall. The simulation experiments have shown that the method can satisfactorily interpret the origins of sediment yield of a small watershed on an effective way. The simulation experiments have also provided basic information for field researches.

  9. Long-term assessment of runoff and sediment transport from grass and agroforestry buffers in corn/soybean watersheds using APEX

    Science.gov (United States)

    Existence of a claypan layer in soils at depths ranging from 4 to 37 cm restricts 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, streams and...

  10. 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...

  11. Reduction rate of nitrogen and phosphorus non-point source pollution under different riparian buffer restoring strategies%不同河岸带修复策略对氮磷非点源污染的净化作用

    Institute of Scientific and Technical Information of China (English)

    赵鹏; 胡艳芳; 林峻宇

    2015-01-01

    This study was conducted along Liuxi River watershed, a main branch of Beijiang River, in Guangdong Province. Based on the non-point source (NPS) pollution and riparian buffer’s reduction in current situations of the Liuxi River Basin, the differences of NPS pollution reduction improvement of different restoration strategies were investigated by scenario simulations. In order to compare the efficiency of different restoration strategies, the relationships between the improvement of NPS reduction rate and the increase of buffer area were interpreted by benefit-cost index. The results showed the NPS reduction rate performed remarkable spatial variation. Each scenario had improved the NPS reduction rates to varying degrees (TN: 23.36%~30.72%; TP: 27.19%~39.86%). The relationships between buffer areas and NPS reduction rate of each scenario were fitted well by the logarithmic function (P<0.05). The strategy with restoring the sub-basins of prior riparian buffer restoration, which integrated NPS loading and riparian buffers conditions, could reach the best benefit-cost index (1.19%).%选择北江的重要支流流溪河流域为研究对象,基于现有河岸带对非点源污染削减作用的模拟结果,采用情景分析法,预测不同河岸带修复策略对非点源污染的削减作用,使用效益-成本指数表征 TN 和 TP 削减率提高幅度与增加河岸带面积的关系,比较不同河岸带修复策略的效率.结果表明:河岸带对TN和TP的削减能力具有较大的空间差异性.各修复情景都在不同程度上提高了河岸带对TN和TP的削减率(TN:23.36%~30.72%;TP:27.19%~39.86%),河岸带增加总面积与削减率呈现对数增长关系(P<0.05).选择综合考虑了流域非点源负荷量以及河岸带状况的优先修复子流域进行河岸带修复时,效益-成本指数达最高为1.19%.

  12. Estimation of nonpoint-source loads of total nitrogen, total phosphorous, and total suspended solids in the Black, Belle, and Pine River basins, Michigan, by use of the PLOAD model

    Science.gov (United States)

    Syed, Atiq U.; Jodoin, Richard S.

    2006-01-01

    The Lake St. Clair Regional Monitoring Project partners planned a 3-year assessment study of the surface water in the Lake St. Clair drainage basins in Michigan. This study included water-quality monitoring and analysis, collection of discrete (grab) and automatic water-quality samples, monitoring of bacteria, and the creation of a database to store all relevant data collected from past and future field-data-collection programs. In cooperation with the Lake St. Clair Monitoring Project, the U.S. Geological Survey assessed nonpoint-source loads of nutrients and total suspended solids in the Black, Belle, and Pine River basins. The principal tool for the assessment study was the USEPA’s PLOAD model, a simplified GIS-based numerical program that generates gross estimates of pollutant loads. In this study, annual loads were computed for each watershed using the USEPA’s Simple Method, which is based on scientific studies showing a correlation between different land-use types and loading rates. The two land-use data sets used in the study (representing 1992 and 2001) show a maximum of 0.02-percent change in any of the 15 land use categories between the two timeframes. This small change in land use is reflected in the PLOAD results of the study area between the two time periods. PLOAD model results for the 2001 land-use data include total-nitrogen loads from the Black, Belle, and Pine River basins of approximately 495,599 lb/yr, 156,561 lb/yr, and 121,212 lb/yr, respectively; total-phosphorus loads of 80,777 lb/yr, 25,493 lb/yr, and 19,655 lb/yr, respectively; and total-suspended-solids loads of 5,613,282 lb/yr, 1,831,045 lb/yr, and 1,480,352 lb/yr, respectively. The subbasins in the Black, Belle, and Pine River basin with comparatively high loads are characterized by comparatively high percentages of industrial, commercial, transportation, or residential land use. The results from the PLOAD model provide useful information about the approximate average annual loading

  13. Evaluating Hydrologic Response of an Agricultural Watershed for Watershed Analysis

    Directory of Open Access Journals (Sweden)

    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.

  14. Study on agricultural structure and non-point source pollution: a case in Dapu Town of Yixing City

    Institute of Scientific and Technical Information of China (English)

    Jiang Dongmei; Wang Xiyuan; Liu Minghui; Lu Genfa

    2006-01-01

    The water body of Taihu Lake has been eutrophicated because of area-source pollution. 83% of the total nitrogen and 84% of the total phosphorus of the pollutant that have washed into Taihu Lake originated from the fertilizer of crop land, rural animal husbandry and living sewage and rubbish in rural area. The goal of adjusting agricultural structure is to improve agricultural development, and to increase the peasants income by planting non-grain crop,centralizing animal husbandry, and intensifying aquaculture, etc, It is necessary to research on the influences of agriculture industrial structure on area-source pollution, This paper studies a case of Dapu Town in Yixing City, which is a typical drainage place beside Taihu Lake. On the basis of the analysis on the status quo of area-source pollution and agriculture industrial structure in Dapu Town, the conflicts between them are discussed. Non-grain crop production with a great deal of fertilizer and developing aquaculture with a great deal of organic pollutant, which are directly discharged,make area-source pollution more serious and accelerate the eutrophication in Taihu Lake. This paper suggests taking corresponding technological measures and policies, which have been tested in Dapu Town and demonstrated in Taihu Lake area.

  15. Relating sediment impacts on coral reefs to watershed sources, processes and management: a review.

    Science.gov (United States)

    Bartley, Rebecca; Bainbridge, Zoe T; Lewis, Stephen E; Kroon, Frederieke J; Wilkinson, Scott N; Brodie, Jon E; Silburn, D Mark

    2014-01-15

    Modification of terrestrial sediment fluxes can result in increased sedimentation and turbidity in receiving waters, with detrimental impacts on coral reef ecosystems. Preventing anthropogenic sediment reaching coral reefs requires a better understanding of the specific characteristics, sources and processes generating the anthropogenic sediment, so that effective watershed management strategies can be implemented. Here, we review and synthesise research on measured runoff, sediment erosion and sediment delivery from watersheds to near-shore marine areas, with a strong focus on the Burdekin watershed in the Great Barrier Reef region, Australia. We first investigate the characteristics of sediment that pose the greatest risk to coral reef ecosystems. Next we track this sediment back from the marine system into the watershed to determine the storage zones, source areas and processes responsible for sediment generation and run-off. The review determined that only a small proportion of the sediment that has been eroded from the watershed makes it to the mid and outer reefs. The sediment transported >1 km offshore is generally the clay to fine silt (erosion is the dominant process responsible for the fine sediment exported from these watersheds in recent times, although further work on the particle size of this material is required. Maintaining average minimum ground cover >75% will likely be required to reduce runoff and prevent sub-soil erosion; however, it is not known whether ground cover management alone will reduce sediment supply to ecologically acceptable levels.

  16. 兰州农村面源污染现状及防治对策分析%The Analysis of the Rural Non-point Source Pollution Situation and Countermeasures in Lan Zhou City

    Institute of Scientific and Technical Information of China (English)

    桂洪杰; 赵军平; 杜海霞; 张君弟; 刘佳

    2011-01-01

    文中在兰州统计年鉴的基础上,根据面源污染来源,分析了农业、畜牧业、生产和生活活动的危害,初步估算了主要面源污染物的流失量。并根据兰州市农村具体情况提出了相应的保护和控制措施,旨在为解决农村面源污染问题和保护农村生态环境提供借鉴。%In this paper,on the basis of Lan Zhou statistical yearbook,We analyzed the dangers of agriculture,animal husbandry,production activities and life activities according to the sources of rural non-point pollution,and then,we preliminary estimate the loss of the main non-point pollutant.In order to Provide reference for solving the problem of non-point pollution and the rural ecological environment protection,we put forward the corresponding protection and control measures,according to the specific situation of Lan Zhou countryside.

  17. Watershed land use effects on lake water quality in Denmark

    DEFF Research Database (Denmark)

    Nielsen, Anders; Trolle, Dennis; Søndergaard, Martin

    2012-01-01

    in the watershed. When examining the effect of different near-freshwater land zones in contrast to the entire watershed, relationships generally improved with size of zone (25, 50, 100, 200, and 400 m from the edge of lake and streams) but were by far strongest using the entire watershed. The proportion......Mitigating nutrient losses from anthropogenic nonpoint sources is today of particular importance for improving the water quality of numerous freshwater lakes worldwide. Several empirical relationships between land use and in-lake water quality variables have been developed, but they are often weak......, which can in part be attributed to lack of detailed information about land use activities or point sources. We examined a comprehensive data set comprising land use data, point-source information, and in-lake water quality for 414 Danish lakes. By excluding point-source-influenced lakes (n = 210...

  18. Trends of nitrogen and phosphorus input into Lake Neusiedl from wastewater treatment plants and non-point sources

    Science.gov (United States)

    Kinner, Paul; Heiss, Gerhard; Soja, Gerhard

    2013-04-01

    nitrogen load amounted to 304 tons in 2010, compared to 47 tons in 2001. In the period 1992-2010 the nitrogen load caused by diffuse sources was 4.3 times higher than the point source nitrogen load (2 wastewater treatment plants). The proportion of total discharge, of inorganic nitrogen load and of phosphorus load caused by the two wastewater treatment plants depended on the discharge rate of the river Wulka (monitoring station Schützen). In 2001 (low precipitation year: 578 mm annual sum) point sources contributed about 47% of the discharge, 51% of the nitrogen load and 65% of the phosphorus load of the river Wulka. In 2010 (high precipitation year: 945 mm annual sum) point sources contributed 25% of the discharge, 11% of the nitrogen load and 31% of the total phosphorus load. In the period 1992 to 2010 the inorganic nitrogen load caused by surface water (Wulka, WWTP, creeks and channels) varied from 65 t/a to 675 t/a (mean:233 t/a).

  19. Sediment source identification and load prediction in a mixed-use Piedmont watershed, South Carolina.

    Science.gov (United States)

    McCarney-Castle, Kerry; Childress, Tristan M; Heaton, Christian R

    2016-10-28

    Many streams in the Piedmont region of the southeastern United States transport a disproportionately large amount of suspended sediment in response to moderately increased streamflows. Transport and deposition of excess sediment affect the stability of the channel and the health of the biological community; therefore, identifying the main source(s) of sediment and assessing the relationships between source, transport, and streamflow are critical to aquatic life and habitat management, dynamic equilibrium preservation, and development of feasible mitigation scenarios. The objectives of this study were to: (1) predict the annual suspended sediment yield and (2) identify significant contributing upland sources of sediment in the Lawsons Fork Creek basin, a 217 km(2) mixed-use watershed in the South Carolina Piedmont. A regularly monitored cross-section located in the downstream reach was equipped with a passive sediment sampler, gage-height recorder, and sediment tiles. Streamflow and sediment concentration were measured over a 24-month period under variable hydrologic regimes. Results indicated that the average annual sediment yield (168 t/km(2)/yr) is significantly higher than yields documented in Piedmont watersheds of comparable size. To identify and prioritize sources of sediment contribution, stable isotopes of nitrogen (δ(15)N) and carbon (δ(13)C) were used as tracers. Source material was compared with suspended sediment near the watershed outlet (target material) and SIAR, a Bayesian Inference model, was used to estimate source apportionment. Results of this source study indicate that approximately 60% of the total sediment load in the water column during high flow events is derived from stream bank erosion. Findings are consistent with observed unstable stream bank conditions in the watershed. This study supports the use of a dual-isotopic fingerprinting approach in tandem with traditional sediment monitoring as a cost-effective method to identify and

  20. Research on Nonpoint Source Pollution Assessment Method in Data Sparse Regions: A Case Study of Xichong River Basin, China

    Directory of Open Access Journals (Sweden)

    Xing Liu

    2015-01-01

    Full Text Available The NPS pollution is difficult to manage and control due to its complicated generation and formation mechanism, especially in the data sparse area. Thus the ECM and BTOPMC were, respectively, adopted to develop an easy and practical assessment method, and a comparison between the outputs of them is then conducted in this paper. The literature survey and field data were acquired to confirm the export coefficients of the ECM, and the loads of TN and TP were statistically analyzed in the study area. Based on hydrological similarity, runoff data from nearby gauged sites were pooled to compensate for the lack of at-site data and the water quality submodel of BTOPMC was then applied to simulate the monthly pollutant fluxes in the two sections from 2010 to 2012. The results showed agricultural fertilizer, rural sewage, and livestock and poultry sewage were the main pollution sources, and under the consideration of self-purification capacity of river, the outputs of the two models were almost identical. The proposed method with a main thought of combining and comparing an empirical model and a mechanistic model can assess the water quality conditions in the study area scientifically, which indicated it has a good potential for popularization in other regions.

  1. 基于博弈论的非点源污染控制模型探讨%Modeling Nonpoint Source Pollution Control from the View of Game Theory

    Institute of Scientific and Technical Information of China (English)

    张蔚文; 刘飞; 王新艳

    2011-01-01

    With the increasing ability to deal with point source pollution, such as industrial and urban life sewage, the impact of agricultural non-point source pollution on water quality environment has become more and more apparent. Compared with point source pollution, non-point source pollution occurs at an uncertain time, in an uncertain way and with uncertain quantity, which brings much more difficulties to the making of some relevant control policies. Beginning with the famous phenomenon of the Tragedy of Commons, this paper analyzes the game situation among the non-point pollution makers based on the marketing game model and the government supervision game model, and then proposes a way to manage and control non-point pollution in the form of "collective performance". Premising with the target of decreasing pollutant discharge, marketing game model proves that it is feasible and efficient to do the trade on point-nonpoint source pollution on the basis of the principle of Optimal Cost, while the results of the government supervision game model show that; a reasonable environment subsidy and punishment mechanism, and government's attaching importance to the self-reputation and public image will play a positive role in promoting non-point source pollution control.%随着对工业和城市生活污水等点源污染治理能力的不断增强,农业非点源污染对水质环境的影响日益凸现.相对于点源污染,非点源污染发生的不确定时间、不确定途径、不确定量等特点给治理政策的制定带来很大难度.本文从著名的公地悲剧现象出发,着力从市场博弈及政府监督博弈两个模型分析非点源污染制造者之间的博弈格局,并提出以“集体表现”的形式对非点源污染进行管理和控制.市场博弈模型中以一定的排污削减目标为前提,确定以成本最优的原则进行点源-非点源排污权交易是可行且有效率的;而政府监督博弈模型的结果显示:合理的

  2. EXPERIMENTAL STUDY ON NONPOINT SOURCE NUTRIENT OUTPUT FROM XIANGXI BASIN IN THREE GORGES RESERVOIR%三峡库区香溪河流域非点源营养盐输出变化的试验研究

    Institute of Scientific and Technical Information of China (English)

    宋林旭; 刘德富; 肖尚斌

    2011-01-01

    综合三峡库区香溪河流域土地利用结构和水系特点,在三大支流出口处设置常规水质监测断面,于干流响滩处设置水文控制断面,通过断面水质水量监测,利用数字滤波法解析径流多源和污染多源,研究上游来流点源和非点源营养盐输出负荷变化。结果表明:受农业非点源污染影响,TN是高岚河(0.788mg/L)〉古夫河(0.712mg/L)〉南阳河(0.567mg/L);南阳河受磷矿企业点源输入的影响,TP是南阳河(0.323mg/L)〉高岚河(0.074mg/L)〉古夫河(0.053mg/L);断面流量与降雨量的相关系数R2=0.%In order to study non-point source nutrient from Xiangxi River,considering the characteristics of the land use and the basin network,establishing the regular quality monitoring and hydrographic control section respectively in 3 major branches and upstream main channel.According to the water quality and quantity monitoring data,studying the spatial and temporal variation of the water quality from the upstream and the flux output process during raining,distinguishing the contribution of nonpoint and point source pollution load by digital filtering technology.The results demonstrate:controlled by agriculture nonpoint source pollution,TN is in GLGFNY,because of the point source pollution from P enterprise,TP is in NYGLGF;the correlation coefficient of flow and rainfall is 0.720 2;annual load ratio of TN and TP is 61% and 40%,during raining,the TN and TP contribution from nonpoint source pollution is 75.2% and 70.9%;the pollution load is decided by the runoff,the correlation of TN/TP load and runoff is that TN is 0.963 6,and TP is 0.978 9.

  3. Identifying and Classifying Pollution Hotspots to Guide Watershed Management in a Large Multiuse Watershed.

    Science.gov (United States)

    Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng

    2017-03-03

    In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world.

  4. Non-Point Source Pollutant Load Variation in Rapid Urbanization Areas by Remote Sensing, Gis and the L-THIA Model: A Case in Bao'an District, Shenzhen, China.

    Science.gov (United States)

    Li, Tianhong; Bai, Fengjiao; Han, Peng; Zhang, Yuanyan

    2016-11-01

    Urban sprawl is a major driving force that alters local and regional hydrology and increases non-point source pollution. Using the Bao'an District in Shenzhen, China, a typical rapid urbanization area, as the study area and land-use change maps from 1988 to 2014 that were obtained by remote sensing, the contributions of different land-use types to NPS pollutant production were assessed with a localized long-term hydrologic impact assessment (L-THIA) model. The results show that the non-point source pollution load changed significantly both in terms of magnitude and spatial distribution. The loads of chemical oxygen demand, total suspended substances, total nitrogen and total phosphorus were affected by the interactions between event mean concentration and the magnitude of changes in land-use acreages and the spatial distribution. From 1988 to 2014, the loads of chemical oxygen demand, suspended substances and total phosphorus showed clearly increasing trends with rates of 132.48 %, 32.52 % and 38.76 %, respectively, while the load of total nitrogen decreased by 71.52 %. The immigrant population ratio was selected as an indicator to represent the level of rapid urbanization and industrialization in the study area, and a comparison analysis of the indicator with the four non-point source loads demonstrated that the chemical oxygen demand, total phosphorus and total nitrogen loads are linearly related to the immigrant population ratio. The results provide useful information for environmental improvement and city management in the study area.

  5. Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed

    NARCIS (Netherlands)

    Möller, A.; Ahrens, L.; Surm, R.; Westerveld, J.; van der Wielen, F.; Ebinghaus, R.; de Voogt, P.

    2010-01-01

    The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the

  6. Evaluation of a Florida coastal golf complex as a local and watershed source of bioavailable contaminants

    Science.gov (United States)

    Lewis, Michael A., Robert L. Quarles, Darrin D. Dantin and James C. Moore. 2004. Evaluation of a Coastal Golf Complex as a Local and Watershed Source of Bioavailable Contaminants. Mar. Pollut. Bull. 48(3-4):254-262. (ERL,GB 1183). Contaminant fate in coastal areas impacte...

  7. A review on Non-point Source Nutrient Pollution of Irrigation Plain Areas%平原灌区农田养分非点源污染研究进展

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    平原灌区作为农业规模化生产的基地,在农业乃至经济社会发展中起到了重要作用,但是随着农业的发展,平原灌区农田非点源污染问题日益严重,研究平原灌区农田非点源污染具有重要意义。文章以平原灌区污染物随水文循环迁移过程为基础对平原灌区养分非点源污染研究进行综述。(1)平原灌区农田非点源污染的主要来源是过量的化肥施用,农药和农膜,秸秆等农作物的降解,牲畜粪便,污水灌溉,灌溉引起的盐渍化以及大气的干湿沉降等;产生及影响因素主要有土壤的理化性质,水分的输入方式和人为管理措施等。(2)降雨径流及灌溉排水条件下污染物在多级渠系中的迁移规律和灌区地表水与地下水的交互耦合作用决定了平原灌区农田非点源污染的输送途径与特征。(3)在监测资料比较缺乏时,采用输出系数法进行负荷估算;在监测资料充足情况下,采用针对灌区特殊的水文特征而改进的经典水文模型对平原灌区农田非点源污染的负荷进行估算。(4)新型肥料、配方施肥、合理的耕作措施及生态沟渠的设置有利于平原灌区农田非点源污染的控制,TMDL (Total Maximum Daily Loads)为平原灌区农田非点源污染控制提供可靠的依据。针对平原灌区非点源污染研究现状,提出了中国开展平原灌区农田非点源污染研究的重点,包括养分污染物在多级沟渠中的迁移,灌区地表与地下水水量水质耦合模型的建立,分级控制单元与TMDL的制定以及多模型结合模拟等,可望在控制农业非点源污染方面起到指导作用。%Plain irrigation areas as the basis of agricultural large-scale production played an important role in agricultural, economic and social development. However, the seriousness of non-point source pollution in plain irrigation areas is increasing with the

  8. Discussion on the Green Tax Stimulation Measure of Nitrogen Fertilizer Non-Point Source Pollution Control - Taking the Dongting Lake Area in China as a Case

    Institute of Scientific and Technical Information of China (English)

    XIANG Ping-an; ZHOU Yan; HUANG Huang; ZHENG Hua

    2007-01-01

    A study on designing the tax of nitrogen fertilizer can provide a new method for controlling nitrogen fertilizer non-point source pollution. The tax design of nitrogen fertilizer was discussed by utilizing the external theory and the demand elasticity theory. The results indicated that the coefficient of price elasticity of nitrogen fertilizer demand is -0.21, which instructed that the market demand is in lack of elasticity in the short period and the impact of nitrogen fertilizer manufacturers is subtle. The 11 counties (cities and boroughs) in the Dongting Lake area in China, where the farmland nitrogen application surpassed the average ecological fertilization dosage, is listed to the taxation scope of nitrogen fertilizer tax. The environment loss will reduce 0.07 hundred million RMB yuan and the revenue will increase 0.89 hundred million RMB yuan in the country after levying on nitrogen fertilizer. The loss, which was brought by the decreasing food supplies production, will be 0.58 hundred million RMB yuan and the net social benefit will be 0.38 hundred million RMB yuan following revenue collection. The variation scope of the increasing expenditure of farmers will range from 0.95 to 1.49%. The variation scope of the income of farmers will range from -8.41 to 6.44%. The 5 areas, Yunxi Borough, Junshan Borough, Hanshou County, Jinshi City, and Ziyang Borough, had an increase in food supplies production after the revenue collection. The environment loss will reduce 0.01 hundred million RMB yuan and the revenue will increase 0.16 hundred million RMB yuan in the country after levying on nitrogen fertilizer. The economic benefits, which was brought by the increasing cereals production, will be 0.67 hundred million RMB yuan and the net social benefit will be 0.84 hundred million RMB yuan after revenue collection. The variation scope of the increasing expenditure of farmers will range from 0.95 to 1.06%. The variation scope of the increasing income of farmers will

  9. Stream restoration and sewers impact sources and fluxes of water,carbon, and nutrients in urban watersheds

    Science.gov (United States)

    An improved understanding of sources and timing of water and nutrient fluxes associated with urban stream restoration is critical for guiding effective watershed management. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P)...

  10. The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater

    Science.gov (United States)

    Pankow, J.F.; Thomson, N.R.; Johnson, R.L.; Baehr, A.L.; Zogorski, J.S.

    1997-01-01

    all no- net recharge cases. The mechanism responsible for this effect was the dispersion acting on each downward infiltration event, and also on the ET-induced flow. The ability of MTBE to reach groundwater in cases 2-5 is taken as evidence of the potential importance of urban air as a non-point source for VOCs in shallow urban groundwater. Two subcases were run for both case 4 and case 5: subcase a (water and VOCs move with ET) and subcase b (water only moves with ET).Numerical simulations were conducted using a 1-D model domain set in medium sand to provide a test of whether methyl-tert-butyl ether (MTBE) and other atmospheric volatile organic compounds could move to shallow groundwater within the 10-15 y time frame over which MTBE was used in large amounts. The gasoline additive MTBE is of special interest because of its: current levels in some urban air; strong partitioning from air into water; resistance to degradation; use as an octane-booster since the 1970s; rapidly increasing use in the 1990s to reduce CO and O3 in urban air; and its frequent detection at low microgram per liter levels in shallow urban groundwater.

  11. Estimation of runoff and sediment yield in the Redrock Creek watershed using AnnAGNPS and GIS

    Institute of Scientific and Technical Information of China (English)

    Tsou Ming-Shu; ZHAN Xiao-yong

    2004-01-01

    Sediment has been identified as a significant threat to water quality and channel clogging that in turn may lead to river flooding. With the increasing awareness of the impairment from sediment to water bodies in a watershed, identifying the locations of the major sediment sources and reducing the sediment through management practices will be important for an effective watershed management. The annualized agricultural non-point source pollution(AnnAGNPS) model and newly developed GIS interface for it were applied in a small agricultural watershed, Redrock Creek watershed, Kansas, in this pilot study for exploring the effectiveness of using this model as a management tool. The calibrated model appropriately simulated monthly runoff and sediment yield through the practices in this study and potentially suggested the ways of sediment reduction through evaluating the changes of land use and field operation in the model for the purpose of watershed management.

  12. Calculation and discussion of non-point source pollution loads in Danjiangkou Reservoir Area%丹江口水库入库非点源污染负荷的计算与讨论

    Institute of Scientific and Technical Information of China (English)

    郑艳霞; 程超; 辛小康

    2015-01-01

    正确估算丹江口水库入库非点源污染负荷对于水源区水环境保护具有重要意义. 根据丹江口库区6条主要入库河流汉江、天河、堵河、丹江、老灌河、淇河控制水文站2013年逐日流量数据,采用数字滤波法对基流进行了分割. 以逐日流量、河川基流量和代表污染物(CODMn和TP)2013年逐月浓度监测值为基础,采用通量法计算了背景污染负荷和点源污染负荷、非点源污染负荷. 结果表明:(1) 6条河流入库流量占总入库流量的95. 9%,非点源污染已成为丹江口水库水质变化的主导因素. (2) 汉江是入库污染负荷的最大来源,其次是堵河. (3) 由于非点源污染伴随降雨汇入河道,水库污染负荷主要集中于丰水期,2013年度丰水期CODMn和TP的比例分别达到了80. 8%和90. 9%.%Correctly estimating the non-point source pollution loads in Danjiangkou Reservoir Area is important to the envi-ronmental protection of the water source area. The Digital Filter method is used to separate the base flows of Hanjiang River, Tianhe River, Duhe River, Danjiang River, Laoguan River and Qihe River in the reservoir basin according to the daily discharge data. Based on the daily flow, the base flow and monthly typical pollutant concentration in 2013, a flux model is set up to calcu-late the background pollution loads, point-source pollution loads and non-point source pollution loads respectively. The calcu-lation results show that in 2013, the inflow discharge of the 6 rivers accounted for 95. 9% of the total inflow, and the total pollu-tion loads of CODMn and TP from the 6 rivers are 58. 2 thousand t and 1. 86 thousand t, while the non-point source pollution loads are 39. 82 thousand t and 1. 544 thousand t, so the non-point source pollution is the decisive factor;Hanjiang River is the largest pollutants contributor to Danjiangkou Reservoir and followed by Duhe River; the non-point source pollution enters into the river channel

  13. 林带对太湖地区农业非点源的控制效应研究%Controlling effects of forest belts on non-point source pollution of agricultural lands in Taihu Lake area, China

    Institute of Scientific and Technical Information of China (English)

    陈金林; 侍璐璐; 张爱国

    2002-01-01

    in water, crops and underground of forest, the transfer and loss of N and P (main water pollutants) in faming ecosystem were studied, and the effects of forest belts on non-point source pollution of agricultural lands was analyzed. The results indicated that the transfer and loss of N and P vary with means of rotation, types of crops and the amount of fertilizer application. Buffering forest belts betweens farmlands and ditches can effectively stop and purify such elements as N and P in soil runoffs, thus controlling non-point source pollution of agricultural lands. When the width ratio of farmland to forest belt is 100 to 40, 50.05% losing N, 29.37% losing P can be absorbed by forest under rape-rice rotation and 30.98% N, 86.73% P can be absorbed by forest under wheat-rice rotation. When the width ratio of farmland to forest belt is 150 to 40, 33.37% losing N, 19.58% losing P can be absorbed by the forest under rape-rice rotation, and under wheat-rice rotation 20.65% lost N and 57.82% lost P can be absorbed. There is only some purification effect when the width ration of farmland to forest belt is 200 to 40. Based on model of buffering forest belts, the width ratio of farmland to forest is determined between 100 to 40 and 150 to 40, because it not only can purify water, but also occupy less farmland. It is suggested that Poplars, with the characteristics of fast-growing and high value, are suitable to be planted as shelter-forest in Taihu Lake Watershed.

  14. 宁夏黄河灌区农业非点源污染损失估算%Economic loss caused by non-point source pollution ——A case study of Ningxia Yellow River Water Irrigation District

    Institute of Scientific and Technical Information of China (English)

    杨引禄; 冯永忠; 杨世琦; 曹艳春; 刘强; 杨改河

    2011-01-01

    Non-point source pollution have become more and more serious and brought enormous danger to water environment in Ningxia Yellow River Water Irrigation District, so it has important significance for ecological security to esti-mate the economic value of losses of pollution load in this area. In this paper, according to the JOHNES export coefficient method, calculation is made of non-point source pollution load in'Ningxia Yellow River Water Irrigation District, and the methoddology of enxironmental economics is used to reckon quantitatively economic loss caused by agricultural non-point source pollution. The results showed that the livestock breeding pollution contributed 41.27% to the pollution load of the area, and 37.25 % to the TN and 4.03 % to the TP pollution load of the area. The planting was the second and the rural domestic waste was the lowest proportion in non-point source pollution load, which was 34.54% and 24.2% to the pollution load of the area. The economic loss caused by the regional non-point source pollution was calculated at about 548.741 million RMB in total, of which about 40.97% was coutributed by livestock breeding pollution, while the planting and the rural areaa domestic waste respectively 35.6% and 23.4% to the all economic loss. This results illuminate that only the control of livestock breeding pollution can reduce economic loss caused by agricultural ono-point source pollution in Ningxia Yellow River Water Irrigation District.%以宁夏黄河灌区为研究区,在充分利用JOHNES输出系数法计算灌区非点源污染负荷的基础上,应用环境经济学中的恢复防护费用法对灌区农业非点源污染产生的负荷转化为经济损失进行估算.结果表明:宁夏黄河灌区禽畜养殖产生的污染负荷最高,占灌区污染负荷的41.27%,其中全氮排放占整个区域污染负荷的37.25%,全磷排放占整个区域污染负荷的4.03%,种植业产生的氮磷污染负荷次之,居民生活

  15. Present Situation and Countermeasures of Agricultural Non-point Source Pollution in Wuhan City%武汉市农业面源污染现状及治理对策

    Institute of Scientific and Technical Information of China (English)

    汪坤乾; 张凯; 苏斌; 夏杏明; 汤少云

    2014-01-01

    从化肥施用、农药使用、农膜使用现状3个方面阐述了武汉市农业面源污染现状和为害性,分析了武汉市农业面源污染产生的原因,提出了建立政府主导的农业面源污染治理机制、应用化肥减量化技术、应用农药减量化和残留控制技术、推广可降解地膜等治理面源污染的对策。%We pointed out the status and harmfulness of agricultural non-point source pollution in Wuhan from the three aspects, including the application of chemical fertilizer, pesticide and agricultural film, and analyzed the factors that caused the problem, in addition, we put forward related countermeasures, including establishing the government leading mechanism to control agricultural non-point source pollution, using chemical fertilizer reduction technology, applying pesticide reduction and residue control technology, and using biodegradable plastic film.

  16. [Non-point loads of soluble cadmium by in situ field experiment with different landuses, in central Hunan province mining area].

    Science.gov (United States)

    Liu, Xiao-li; Zeng, Zhao-xia; Chen, Zhe; Tie, Bai-qing; Chen, Qiu-wen; Ye, Chang-cheng

    2013-09-01

    Non-point source loads of heavy metals from contaminated soil has increasingly become the major cause of heavy metal concentrations of rivers and lakes surpassed the limitation value, while only few studies had focused on quantitative monitoring of soil heavy metal transportation to water, in situ field conditions. As reported, agricultural farmland heavy metal contamination was the major contamination problem, especially for cadmium (Cd) pollution in middle and downstream of Xiangjiang River. This study selected the typical Cd polluted agricultural watershed for a case study, three typical landuse types of rice, dry farmland and unused grassland with three replicate quadrates were carried out for natural rainfall runoff hydrology processes monitoring, from 2011-2012. Results showed that, precipitation pH value increased from spring to summer, soluble Cd concentration of spring runoff was significantly higher than that of summer rainfall runoff, which presented an obviously seasonal heterogeneity and had a negative correlation with rainfall pH value, and rainfall pH value can obviously impact soil soluble Cd transportation into surface runoff charge. In the same rainfall event, soluble Cd concentration and non-point load of rice were significantly lower than those of dry land and unused grassland, while no obviously seasonal trend was found for non-point load of Cd from three typical landuse types because of the rainfall depth variance, which needs more researches and concerns in the future. These results can provide valuable data and scientific supports for watershed scale's heavy metal non-point source load quantitative estimation and water environment management and water quality diagnosis and early warning.

  17. Incorporation of Complex Hydrological and Socio-economic Factors for Non-point Source Pollution Control: A Case Study at the Yincungang Canal, the Lake Tai Basin of China

    Science.gov (United States)

    Yang, X.; Luo, X.; Zheng, Z.

    2012-04-01

    It is increasingly realized that non-point pollution sources contribute significantly to water environment deterioration in China. Compared to developed countries, non-point source pollution in China has the unique characteristics of strong intensity and composition complexity due to its special socioeconomic conditions. First, more than 50% of its 1.3 billion people are rural. Sewage from the majority of the rural households is discharged either without or only with minimal treatment. The large amount of erratic rural sewage discharge is a significant source of water pollution. Second, China is plagued with serious agricultural pollution due to widespread improper application of fertilizers and pesticides. Finally, there lack sufficient disposal and recycling of rural wastes such as livestock manure and crop straws. Pollutant loads from various sources have far exceeded environmental assimilation capacity in many parts of China. The Lake Tai basin is one typical example. Lake Tai is the third largest freshwater lake in China. The basin is located in the highly developed and densely populated Yangtze River Delta. While accounting for 0.4% of its land area and 2.9% of its population, the Lake Tai basin generates more than 14% of China's Gross Domestic Production (GDP), and the basin's GDP per capita is 3.5 times as much as the state average. Lake Tai is vital to the basin's socio-economic development, providing multiple services including water supply for municipal, industrial, and agricultural needs, navigation, flood control, fishery, and tourism. Unfortunately, accompanied with the fast economic development is serious water environment deterioration in the Lake Tai basin. The lake is becoming increasingly eutrophied and has frequently suffered from cyanobacterial blooms in recent decades. Chinese government has made tremendous investment in order to mitigate water pollution conditions in the basin. Nevertheless, the trend of deteriorating water quality has yet to

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

    Science.gov (United States)

    Nightingale, Michael; Mayer, Bernhard

    2012-01-01

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

  19. Watershed Assessment with Beach Microbial Source Tracking and Outcomes of Resulting Gull Management.

    Science.gov (United States)

    Goodwin, Kelly D; Gruber, Steve; Vondrak, Mary; Crumpacker, Andrea

    2016-09-20

    Total maximum daily load (TMDL) implementation at a southern California beach involved ultraviolet treatment of watershed drainage that provided >97% reduction in fecal indicator bacteria (FIB) concentrations. However, this pollutant control measure did not provide sufficient improvement of beach water quality, prompting further assessment. Investigation included microbial source tracking (MST) for human, gull, and canine fecal sources, monitoring of enterococci and fecal coliform, and measurement of chemical and physical water quality parameters for samples collected from watershed, groundwater, and beach sites, including a beach scour pond and tidal creek. FIB variability remained poorly modeled in regression analysis. However, MST revealed correlations between FIB and gull source tracking markers, leading to recommendations to manage gulls as a pollutant source. Beach conditions were followed for three years after implementation of a best management practice (BMP) to abate gulls using a falconry program for the beach and an upland landfill. The gull abatement BMP was associated with improved beach water quality, and this appears to be the first report of falconry in the context of TMDL implementation. Overall, MST data enabled management action despite an inability to fully model FIB dynamics in the coupled watershed-beach system.

  20. Microbial Source Tracking in a Watershed Dominated by Swine

    Directory of Open Access Journals (Sweden)

    Joice F. Lubbers

    2010-09-01

    Full Text Available The high concentration of swine production in southeastern North Carolina generates public health concerns regarding the potential transport of pathogens from these production systems to nearby surface waters. The microbial source tracking (MST tool, antibiotic resistance analysis (ARA, was used to identify sources of E. coli in a segment of Six Runs Creek in Sampson County, North Carolina. Among 52 water samples, fecal coliform (FC counts averaged 272.1 ± 181.6 CFU/100 mL. Comparisons of isolates from water samples to an ARA library with an average rate of correct classification (ARCC of 94.3% indicated an average of 64% and 27.1% of 1,961 isolates from Six Runs Creek were associated with lagoon effluent and cattle manure respectively. The potential for aerosol transport of bacteria during lagoon spray events, as well as, the potential for wildlife to serve as a vehicle of transport for bacteria from fields and lagoons to nearby surface waters should be investigated further.

  1. Developing Participatory Models of Watershed Management in the Sugar Creek Watershed (Ohio, USA

    Directory of Open Access Journals (Sweden)

    Jason Shaw Parker

    2009-02-01

    Full Text Available The US Environmental Protection Agency (USEPA has historically used an expert-driven approach to water and watershed management. In an effort to create regulatory limits for pollution-loading to streams in the USA, the USEPA is establishing limits to the daily loading of nutrients specific to each watershed, which will affect many communities in America. As a part of this process, the Ohio Environmental Protection Agency ranked the Sugar Creek Watershed as the second "most-impaired" watershed in the State of Ohio. This article addresses an alternative approach to watershed management and that emphasises a partnership of farmers and researchers, using community participation in the Sugar Creek to establish a time-frame with goals for water quality remediation. Of interest are the collaborative efforts of a team of farmers, researchers, and agents from multiple levels of government who established this participatory, rather than expert-driven, programme. This new approach created an innovative and adaptive model of non-point source pollution remediation, incorporating strategies to address farmer needs and household decision making, while accounting for local and regional farm structures. In addition, this model has been adapted for point source pollution remediation that creates collaboration among local farmers and a discharge-permitted business that involves nutrient trading.

  2. 重庆市四面山4种森林群落面源污染控制功能分析%The non-point source pollution control function of four forest communities in Simian Mountains, Chongqing

    Institute of Scientific and Technical Information of China (English)

    荣文卓; 张洪江; 杜仕才; 程金花; 王伟; 李根平; 古德洪

    2009-01-01

    Selecting canopy interception rate, capillary porosity,non-capillary porosity and soil anti-erosion coefficient as analysis indices, the function of non-point source pollution control of four forest communities in Simian Mountains of Chongqing were ana-lyzed by Grey Relational Grade Analiysis. The results show that the grey correlation degree of natural Phyllostachys pubescens for-est is 0.887 7, hgher than other three communities, which means that the function of non-point source pollution control of Phyl-lostachys pubescens forest is the best. In the planatations types, the grey correlation degree of broadleaf forest is the highest, 0.779 4, followed by mixed broadleaf-conifer forest (0.699 2). The grey correlation degree of coniferous forest is the lowest, 0.636 1. Which means it has the lowest function for non-point source pollution control.%以重庆市四面山4种森林群落为研究对象,选取林冠截留率、林地土壤毛管孔隙度、林地土壤非毛管孔隙度和林地0~20 cm土壤抗冲刷系数为分析指标,运用灰色关联度法对4种森林群落的面源污染控制功能进行研究.结果表明:在4种森林群落中作为天然林的楠竹林灰关联度值最大为0.887 7,面源污染控制功能最好,其次是人工阔叶林(0.7794)和人工混交林(0.6992),人工针叶林(0.636 1)面源污染防控能力相对较弱.在人工林方面,阔叶林灰关联度值最大为0.7794,面源污染防控能力最好,其次是针阔混交林(0.699 2),针叶林灰关联度值最低为0.636 1,其面源污染防控能力较弱.

  3. Groundwater pollution of post-mined phosphate rock in Tuojiang watershed (Sichuan, China)

    Science.gov (United States)

    changwen, ye

    2014-05-01

    Phosphate rock is the source of phosphorus used to make phosphatic fertilizers, essential for growing the food needed by humans in the world today and in the future. The erosion and eluviation on exposed phosphrite layer and overburden in the phosphate rock areas result in the releasing of fluoride and phosphorus and groundwater polluting. Meanwhile, the waste water and untreated mineral waste residue in the beneficiation and mining operations are also main source of pollution. The un-restored post-mined phosphate rock areas in Tuojiang watershed is large scale. The investigation of the amounts of pollutants releasing from mined lands and transporting by runoffs was conducted. The releasing and transporting amounts of pollutants were calculated according to the results of column leaching studies and acreages of exposed phosphrite layers and overburdens. In conclusion, phosphorus mining activity is an important non-point source of groundwater contamination of Tuojiang watershed.Study about the management and engineering measurement can be carried out according to the non-point source: agriculture, Pollution, Phosphorous mine and chemical plant. The study can provide the practical consultation and help making the decision about the management and treatment of groundwater resource in Tuojiang watershed. Keywords: Tuojiang watershed; Groundwater pollution; Losing process; Fluorine; Phosphorus

  4. Using Bayesian hierarchical models to better understand nitrate sources and sinks in agricultural watersheds.

    Science.gov (United States)

    Xia, Yongqiu; Weller, Donald E; Williams, Meghan N; Jordan, Thomas E; Yan, Xiaoyuan

    2016-11-15

    Export coefficient models (ECMs) are often used to predict nutrient sources and sinks in watersheds because ECMs can flexibly incorporate processes and have minimal data requirements. However, ECMs do not quantify uncertainties in model structure, parameters, or predictions; nor do they account for spatial and temporal variability in land characteristics, weather, and management practices. We applied Bayesian hierarchical methods to address these problems in ECMs used to predict nitrate concentration in streams. We compared four model formulations, a basic ECM and three models with additional terms to represent competing hypotheses about the sources of error in ECMs and about spatial and temporal variability of coefficients: an ADditive Error Model (ADEM), a SpatioTemporal Parameter Model (STPM), and a Dynamic Parameter Model (DPM). The DPM incorporates a first-order random walk to represent spatial correlation among parameters and a dynamic linear model to accommodate temporal correlation. We tested the modeling approach in a proof of concept using watershed characteristics and nitrate export measurements from watersheds in the Coastal Plain physiographic province of the Chesapeake Bay drainage. Among the four models, the DPM was the best--it had the lowest mean error, explained the most variability (R(2) = 0.99), had the narrowest prediction intervals, and provided the most effective tradeoff between fit complexity (its deviance information criterion, DIC, was 45.6 units lower than any other model, indicating overwhelming support for the DPM). The superiority of the DPM supports its underlying hypothesis that the main source of error in ECMs is their failure to account for parameter variability rather than structural error. Analysis of the fitted DPM coefficients for cropland export and instream retention revealed some of the factors controlling nitrate concentration: cropland nitrate exports were positively related to stream flow and watershed average slope

  5. Antibiotic resistance analysis of fecal coliforms to determine fecal pollution sources in a mixed-use watershed.

    Science.gov (United States)

    Burnes, Brian S

    2003-06-01

    Antibiotic resistance analysis was performed on fecal coliform (FC) bacteria from a mixed-use watershed to determine the source, human or nonhuman, of fecal coliform contamination. The study consisted of discriminant analysis of antibiotic resistance patterns generated by exposure to four concentrations of six antibiotics (ampicillin, gentamicin sulfate, kanamycin, spectinomycin dihydrochloride, streptomycin sulfate, and tetracycline hydrochloride). A reference database was constructed from 1125 fecal coliform isolates from the following sources: humans, domestic animals (cats and dogs), agricultural animals (chickens, cattle, and horses), and wild animals. Based on similar antibiotic resistance patterns, cat and dog isolates were grouped as domestic animals and horse and cattle isolates were grouped as livestock. The resulting average rate of correct classification (ARCC) for human and nonhuman isolates was 94%. A total of 800 FC isolates taken from the watershed during either a dry event or a wet event were classified according to source. Human sources contribute a majority (> 50%) of the baseflow FC isolates found in the watershed in urbanized areas. Chicken and livestock sources are responsible for the majority of the baseflow FC isolates found in the rural reaches of the watershed. Stormwater introduces FC isolates from domestic (approximately 16%) and wild (approximately 21%) sources throughout the watershed and varying amounts (up to 60%) from chicken and livestock sources. These results suggest that antibiotic resistance patterns of FC may be used to determine sources of fecal contamination and aid in the direction of water quality improvement.

  6. A Review of the Research on Eco-Technologies for Control of Urban Nonpoint Source Pollution%城市面源污染生态控制技术研究进展

    Institute of Scientific and Technical Information of China (English)

    王书敏; 于慧; 张彬

    2011-01-01

    快速城市化导致了土地利用类型的迅速变化,由此引起的城市面源污染已成为威胁城市水体健康的主要因素。根据国内外最近几年的研究情况,从净化机理、运行效能、影响因素及评价方法等方面详细介绍了缓冲带、绿色屋顶、植草沟等面源生态控制技术的应用研究情况。各类研究指出,在确保适宜的宽度和坡度、连续植被覆盖的植被缓冲带对消减径流和清除沉积物是极其有效的;绿色屋顶对径流污染消减能力受屋面介质厚度、屋顶坡度、降雨强度、植物类型、土壤层湿度等因素的影响明显;植草沟对于沉积物和重金属去除效率高,而对于易引起水体富营养化的溶解性营养盐的去除效能有待改善,构建介质优化是关键。指出充分发挥各种生态技术的优势、构建城市面源污染生态控制网络是消除城市面源污染毒性、维护健康城市水环境的重要途径。%Land use type has been changed rapidly because of the speeding urbanization,and urban nonpoint source pollution has become the prominent reason of urban waters' deterioration.According to researches in recent years,studies about nonpoint source eco-control technologies such as buffer zones,green roofs and bioswales were introduced in detail in purification mechanism,operating performance,affecting factors,evaluation methods,and other aspects.Buffer zones were very effective in reducing runoff and removing sediment as long as appropriate width and slope,and continuous vegetation covering were ensured.Ability of green roofs in controlling runoff pollution was correlated greatly with medium thickness,roof slope,rainfall intensity,plant type,soil moisture levels and other factors. The efficiencies for removal of TSS and heavy metals by bioswales were very high,however,the ability to control soluble nutrition was still needed to be improved whilst the construction media were the key factor

  7. 国内外遥感技术在非点源污染模拟中的应用%Application of Remote Sensing Technology in Non-point Source Pollution Monitoring

    Institute of Scientific and Technical Information of China (English)

    王天培

    2011-01-01

    综述了遥感技术在土壤类型和性质、植被类型和性质、水文气象以及土地利用等直接影响非点源污染产生的因素中的应用,以期为模型模拟与遥感技术联合研究非点源污染提供借鉴.%The application of remote sensing technology on the main factors, including soil types and properties, characteristics of vegetation,hydrological process, meteorological information, land use and so on were discussed in this paper so as to provide references for using modelsimulation and remote sensing technology to study the non-point source pollution.

  8. Statistical Analysis and water Quality Modeling for a Drinking Water Source Watershed for the City of Houston, Texas

    Science.gov (United States)

    Teague, A.; Bedient, P.; Vieux, B. E.

    2009-12-01

    Water quality is a problem in Lake Houston, the primary source of drinking water for the City of Houston, due to pollutant loads coming from the influent watersheds, including Cypress Creek. Water quality issues in the watershed that are of concern for the lake include nutrient enrichment bacterial impairment, both of which present operational challenges for the drinking water treatment plant operations. Statistical analysis of the historic water quality data was developed in order to understand the source characterization and seasonality of the watershed. Multivariate analysis including principal component, cluster, and discriminant analysis provided a unique seasonal assessment of the watershed leading to refined loading curves have been analyzed using data collected by the USGS at 3 sites in Cypress Creek with corresponding City of Houston water quality data at the sites for the past 5 years to characterize the behavior of the pollutant source and watershed. A VfloTM hydrologic model from Vieux & Assoc., Inc for the watershed of the influent stream Cypress Creek was developed to predict the watershed flows into Lake Houston. A distributed model of a large scale watershed, it uses finite element analysis to solve the kinematic wave equation. The model incorporates land use relationships to predict runoff from Radar rainfall data. Continuous VfloTM was run for storm events and the distributed discharge of the watershed simulated. From the spatial discharge output, nutrient wash-off and convective transport was simulated. The simulated nutrient transport was then compared to storm sampling data at a downstream location to assess the water quality model and determine needed future refinements.

  9. 英国农业面源污染防控对我国的启示%Prevention and control of agricultural non-point source pollutions in UK and suggestions to China

    Institute of Scientific and Technical Information of China (English)

    刘坤; 任天志; 吴文良; 孟凡乔; Jessica Bellarby; Laurence Smith

    2016-01-01

    Currently, the world is facing challenges of maintaining food production growth while improving agricultural ecological environ-mental quality. The prevention and control of agricultural non-point source pollution, a key component of these challenges, is a systematic program which integrates many factors such as technology and its extension, relevant regulation and policies. In the project of UK-China Sustainable Agriculture Innovation Network, we undertook a comprehensive analysis of the prevention and control technology, technology extension systems and related policy measures of agricultural non-point source pollution in UK. We then proposed the promotion of preven-tion and control of agricultural non-point source pollution in China. Considering the current agricultural resources and environment counter-measures of“one control”(control over the total quantity of the agricultural water and agricultural water environment pollution),“two re-duction”(reduction in quantities of fertilizers and pesticides), and “three basic countermeasures”(resource utilization, recycling, and disharm treatment of livestock and poultry wastes, agricultural plastic films and crop straws), we suggested that in the near future source control and process prevention should be technical priorities. Optimzation and reduction of chemical fertilizer, combined use of chemical and organic fertilizers, land utilization management, agricultural sector adjustment and integration of crop production with animal husbandry should be the key technologies. The role of non-governmental technical service should be promoted. Government subsidies, ecological com-pensations and other forms of economic means could be used to encourage famers actively participate in the prevention and control of nitro-gen and phosphorus losses and pollution in soil and water systems. Related technical documents and regulations should be more specific, clear, and practical. Collection, transmission and analysis of

  10. Investigation on Present Xingtai Agricultural Non-point Source Pollution and Preventive Countermeasures%邢台市农业面源污染现状及防治对策

    Institute of Scientific and Technical Information of China (English)

    陈计兵

    2014-01-01

    Xingtai has a large population, with a serious contradiction between demand for food and land supply. The development of agriculture has brought about some pollution, and agricultural non-point source pollution prevention and control is the basic guarantee to realize agricultural sustainable development. Xingtai agricultural non-point source pollution is serious. The pollutants mainly include chemical fertilizer, chemical pesticide, agricultural plastic films, livestock and poultry breeding wastes and life wastes. The pollution has caused the decrease of the farmland quality, the degradation of the quality of agricultural products and water, the damage of the ecological balance. The countermeasures include technical measures, management measures, publicity and education measures, etc.%邢台市人口数量大、粮食需求、土地供给矛盾突出,在农业发展中,产生了一些不可忽视的污染现象,而农业面源污染的防治是实现农业可持续发展的基本保障。邢台市农业面源污染比较严重,污染源主要包括化学肥料污染、化学农药污染、农膜污染、畜禽养殖业污染和生活废弃物污染;污染带来耕地质量下降、农产品和水质质量变差、破坏生态平衡等危害;防治对策包括技术措施、管理措施及宣传教育措施等。

  11. Utility of Microbial Source-Tracking Markers for Assessing Fecal Contamination in the Portage River Watershed, Northwestern Ohio, 2008

    Science.gov (United States)

    Kephart, Christopher M.; Bushon, Rebecca N.

    2010-01-01

    An influx of concentrated animal feeding operations in northwest Ohio has prompted local agencies to examine the effects of these industrial farms on water quality in the upper Portage River watershed. The utility of microbial source-tracking (MST) tools as a means of characterizing sources of fecal contamination in the watershed was evaluated. From 2007 to 2008, scientists with the U.S. Geological Survey, Bowling Green State University, and the Wood County Health Department collected and analyzed 17 environmental samples and 13 fecal source samples for Bacteroides-based host-associated DNA markers. At many of the environmental sites tested, MST marker results corroborated the presumptive fecal contamination sources. Results from this demonstration study support the utility of using MST with host-specific molecular markers to characterize the sources of fecal contamination in the Portage River watershed.

  12. Anthropogenic point-source and non-point-source nitrogen inputs into Huai River basin and their impacts on riverine ammonia-nitrogen flux

    Science.gov (United States)

    Zhang, W. S.; Swaney, D. P.; Li, X. Y.; Hong, B.; Howarth, R. W.; Ding, S. H.

    2015-07-01

    This study provides a new approach to estimate both anthropogenic non-point-source and point-source nitrogen (N) inputs to the landscape, and determines their impacts on riverine ammonia-nitrogen (AN) flux, providing a foundation for further exploration of anthropogenic effects on N pollution. Our study site is Huai River basin of China, a water-shed with one of the highest levels of N input in the world. Multi-year average (2003-2010) inputs of N to the watershed are 27 200 ± 1100 kg N km-2 yr-1. Non-point sources comprised about 98 % of total N input, and only 2 % of inputs are directly added to the aquatic ecosystem as point sources. Fertilizer application was the largest non-point source of new N to the Huai River basin (69 % of net anthropogenic N inputs), followed by atmospheric deposition (20 %), N fixation in croplands (7 %), and N content of imported food and feed (2 %). High N inputs showed impacts on riverine AN flux: fertilizer application, point-source N input, and atmospheric N deposition were proved as more direct sources to riverine AN flux. Modes of N delivery and losses associated with biological denitrification in rivers, water consumption, interception by dams may influence the extent of export of riverine AN flux from N sources. Our findings highlight the importance of anthropogenic N inputs from both point sources and non-point sources in heavily polluted watersheds, and provide some implications for AN prediction and management.

  13. Source Apportionment of Non-point Source Nitrogen Pollution in Ashi River Basin Usingδ15N Technique%阿什河流域非点源氮污染的δ15N源解析研究

    Institute of Scientific and Technical Information of China (English)

    胡钰; 王业耀; 滕彦国; 香宝; 马广文; 方广玲

    2015-01-01

    crop farming on water nitro-gen pollution were dependent on river water seasonal periods and farming cycles. During the normal water period, non-point nitrogen pollu-tion by crop farming occurred mainly in the midstream and downstream sections, with δ15N value ranging from 0.46%to 0.77%. The pollu-tion sources were primarily artificial chemical fertilizers and farmland water recession. During the high water period, the pollution from non-point nitrogen extended to the upstream area, withδ15N range of 0.19%~0.4%. The main pollution source was artificial chemical fertilizers in the upstream area, while it was soil organic nitrogen via soil erosion caused by rainfall and irrigation in the midstream and downstream. Dur-ing the low water period, however, artificial chemical fertilizers were still the main contributor of non-point nitrogen pollution, with δ15N val-ues of 0.11%to 0.39%. This was resulted from the feedback of the nitrite-nitrogen from artificial chemical fertilizers that were applied and infiltrated in the ground during the monsoon.

  14. An analysis of urban development and its environmental impact on the Tampa Bay watershed

    Science.gov (United States)

    Xian, G.; Crane, M.; Su, J.

    2007-01-01

    Urbanization has transformed natural landscapes into anthropogenic impervious surfaces. Urban land use has become a major driving force for land cover and land use change in the Tampa Bay watershed of west-central Florida. This study investigates urban land use change and its impact on the watershed. The spatial and temporal changes, as well as the development density of urban land use are determined by analyzing the impervious surface distribution using Landsat satellite imagery. Population distribution and density are extracted from the 2000 census data. Non-point source pollution parameters used for measuring water quality are analyzed for the sub-drainage basins of Hillsborough County. The relationships between 2002 urban land use, population distribution and their environmental influences are explored using regression analysis against various non-point source pollutant loadings in these sub-drainage basins. The results suggest that strong associations existed between most pollutant loadings and the extent of impervious surface within each sub-drainage basin in 2002. Population density also exhibits apparent correlations with loading rates of several pollutants. Spatial variations of selected non-point source pollutant loadings are also assessed. ?? 2006 Elsevier Ltd. All rights reserved.

  15. Quantification of BMPs Selection and Spatial Placement Impact on Water Quality Controlling Plans in Lower Bear River Watershed, Utah

    Science.gov (United States)

    Salha, A. A.; Stevens, D. K.

    2016-12-01

    The aim of the watershed-management program in Box Elder County, Utah set by Utah Division of Water Quality (UDEQ) is to evaluate the effectiveness and spatial placement of the implemented best-management practices (BMP) for controlling nonpoint-source contamination at watershed scale. The need to evaluate the performance of BMPs would help future policy and program decisions making as desired end results. The environmental and costs benefits of BMPs in Lower Bear River watershed have seldom been measured beyond field experiments. Yet, implemented practices have rarely been evaluated at the watershed scale where the combined effects of variable soils, climatic conditions, topography and land use/covers and management conditions may significantly change anticipated results and reductions loads. Such evaluation requires distributed watershed models that are necessary for quantifying and reproducing the movement of water, sediments and nutrients. Soil and Water Assessment Tool (SWAT) model is selected as a watershed level tool to identify contaminant nonpoint sources (critical zones) and areas of high pollution risks. Water quality concerns have been documented and are primarily attributed to high phosphorus and total suspended sediment concentrations caused by agricultural and farming practices (required load is 460 kg/day of total phosphorus based on 0.075 mg/l and an average of total suspended solids of 90 mg/l). Input data such as digital elevation model (DEM), land use/Land cover (LULC), soils, and climate data for 10 years (2000-2010) is utilized along with observed water quality at the watershed outlet (USGS) and some discrete monitoring points within the watershed. Statistical and spatial analysis of scenarios of management practices (BMP's) are not implemented (before implementation), during implementation, and after BMP's have been studied to determine whether water quality of the two main water bodies has improved as required by the LBMR watershed's TMDL

  16. Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Axel, E-mail: axel.moeller@gkss.d [GKSS Research Centre Geesthacht GmbH, Institute for Coastal Research, 21502 Geesthacht (Germany); Ahrens, Lutz; Surm, Renate [GKSS Research Centre Geesthacht GmbH, Institute for Coastal Research, 21502 Geesthacht (Germany); Westerveld, Joke; Wielen, Frans van der [University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Amsterdam (Netherlands); Ebinghaus, Ralf [GKSS Research Centre Geesthacht GmbH, Institute for Coastal Research, 21502 Geesthacht (Germany); Voogt, Pim de [University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Amsterdam (Netherlands); KWR Watercycle Research Institute, Nieuwegein (Netherlands)

    2010-10-15

    The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the North Sea and to identify replacement compounds of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In addition, an interlaboratory comparison of the method performance was conducted. The PFAS pattern was dominated by perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) with concentrations up to 181 ng/L and 335 ng/L, respectively, which originated from industrial point sources. Fluxes of {Sigma}PFAS were estimated to be {approx}6 tonnes/year which is much higher than previous estimations. Both, the River Rhine and the River Scheldt, seem to act as important sources of PFAS into the North Sea. - The short-chained polyfluoroalkyl substances PFBA and PFBS replace PFOA and PFOA as dominating PFAS in surface waters in the River Rhine watershed.

  17. Apportioning riverine DIN load to export coefficients of land uses in an urbanized watershed.

    Science.gov (United States)

    Shih, Yu-Ting; Lee, Tsung-Yu; Huang, Jr-Chuan; Kao, Shuh-Ji; Chang

    2016-08-01

    The apportionment of riverine dissolved inorganic nitrogen (DIN) load to individual land use on a watershed scale demands the support of accurate DIN load estimation and differentiation of point and non-point sources, but both of them are rarely quantitatively determined in small montane watersheds. We introduced the Danshui River watershed of Taiwan, a mountainous urbanized watershed, to determine the export coefficients via a reverse Monte Carlo approach from riverine DIN load. The results showed that the dynamics of N fluctuation determines the load estimation method and sampling frequency. On a monthly sampling frequency basis, the average load estimation of the methods (GM, FW, and LI) outperformed that of individual method. Export coefficient analysis showed that the forest DIN yield of 521.5kg-Nkm(-2)yr(-1) was ~2.7-fold higher than the global riverine DIN yield (mainly from temperate large rivers with various land use compositions). Such a high yield was attributable to high rainfall and atmospheric N deposition. The export coefficient of agriculture was disproportionately larger than forest suggesting that a small replacement of forest to agriculture could lead to considerable change of DIN load. The analysis of differentiation between point and non-point sources showed that the untreated wastewater (non-point source), accounting for ~93% of the total human-associated wastewater, resulted in a high export coefficient of urban. The inclusion of the treated and untreated wastewater completes the N budget of wastewater. The export coefficient approach serves well to assess the riverine DIN load and to improve the understanding of N cascade.

  18. Complementing firewood with alternative energy sources in Rio Pardo Watershed, Brazil

    Directory of Open Access Journals (Sweden)

    Luana Dessbesell

    Full Text Available ABSTRACT: Wood is the primary energy source for grains and Tobacco drying in the Rio Pardo Watershed (RPW. The amount of firewood produced in the RPW is not enough to supply the demand. Recently, an automatized supply system was introduced in the region enabling the use of sawdust and pellets. In this context, this study aims to compare firewood, sawdust and pellets as energy sources for Tobacco curing in air-forced curing systems. Energetic density was used to estimate the biomass consumption in Tobacco curing. The consumption of biomass is lower for pellet, followed by firewood and sawdust. Pellets and sawdust could complement firewood in the region; however, research is necessary to ascertain the economic feasibility.

  19. Research progress in erosion-type nonpoint source poLLution process simuLationof the Loess PLateau%黄土高原水土流失型非点源污染过程模拟研究进展

    Institute of Scientific and Technical Information of China (English)

    吴磊; 马孝义

    2015-01-01

    Loss of nitrogen and phosphorus in soil and water loss area of the Loess Plateau not only reduces the utilization rate of fertilizer,but also is a potential threat to aquatic environments.This study takes the typicality of soil and nutrient loss in the Lo-ess Plateau Region as a starting point to deeply analyse and systematically summarize the basic status of the Loss Plateau,the re-search progress of hydrological process,soil erosion,erosion-type nonpoint source pollution and its control strategies of the Loess Plateau.Aiming at the few existing studies on the Loess Plateau,the key research directions of nonpoint source pollution in the Loess Plateau for the future were proposed,such as the loss mechanism of nonpoint source pollution,the load estimation method of nonpoint source pollution in the Loess Plateau,the coupled model of water,sediment and pollution in the Loess Plateau,the combined application of 3S technology and control strategies of erosion-type nonpoint source pollution in the Loess Plateau etc.This re-sult may provide reference for studying the modeling process of erosion-type nonpoint source pollution in the Loess Plateau.%黄土高原严重的水土流失造成了土壤氮磷流失,不仅降低了化肥的利用率,而且对水环境造成了潜在威胁。从黄土高原区水土与养分流失的典型性入手,剖析和总结了黄土高原区基本概况、水文过程、土壤侵蚀、水土流失型非点源污染过程模拟及防控策略等的研究进展。针对目前黄土高原区尤其是黄土丘陵沟壑区非点源污染研究较少,提出了未来黄土高原地区非点源污染的研究方向与建议:黄土区非点源污染物流失机理,非点源污染负荷估算方法,流域水、沙、污染物耦合模型以及3S 技术与流域非点源污染防控决策耦合应用等。

  20. 模拟排水沟渠非点源溶质氮迁移实验研究%Transformation of Non-point Source Soluble Nitrogen in Simulated Drainage Ditch

    Institute of Scientific and Technical Information of China (English)

    李强坤; 宋常吉; 胡亚伟; 彭聪; 马强; 姜正曦; 琚艺萌

    2016-01-01

    The drainage ditch has a compound ecosystem structure consisting of water, sediment and plants. Migration and transformation of the non-point source solute is important to study interception, control and management of agricultural non-point source pollution in the drainage ditch. Based on the experiment on static simulation of drainage ditches, the article used typical non-point source soluble nitrogen as an example to analyze the changing process of nitrogen content in water, sediment and reeds, and to study the effects of the sediment adsorption and desorption, reeds growth and death in different periods on nitrogen concentration in water. The article discussed nitrogen migration in water-sediment- reeds compound ecosystem and its influence on nitrogen concentration in water. The results showed that both adsorption and desorption in sediment and absorption and assimilation of reeds growth had effect on nitrogen concentration in water. The effect before October was reducing the nitrogen concentration in water, which was the process of nitrogen purification in water. After October, the nitrogen concentration in water increased and made it easy to form secondary nitrogen pollution. Meanwhile, the migration in the water-sediment-seeds ecosystem in simulated drainage ditch had close ties, any migration and transformation of nitrogen in a single medium or between different mediums would cause adjustment of nitrogen concentration in water.%农田排水沟渠是由水-底泥-植物组成的复合生态结构,其间非点源溶质的迁移转化对研究沟渠拦截、控制和管理农业非点源污染具有重要意义。本研究以模拟排水沟渠静态实验为基础,以典型非点源溶质氮素为例,分析了实验期内水体、底泥及芦苇不同介质内氮含量变化过程,分析了底泥吸附与解析、芦苇生长与衰败等年内不同时期对水体中氮素浓度的影响,探讨了水-底泥-芦苇复合生态体内氮迁移及对水体中氮

  1. Research Progress on Guangdong Agricultural Non-point Source Pollution Control-Conservation Agriculture Project%广东农业面源污染治理保护性耕作项目研究进展

    Institute of Scientific and Technical Information of China (English)

    任小平; 区颖刚; 杨丹彤; 唐湘如; 胡建广

    2015-01-01

    广东省属于农业大省,近年来随着人口增加和农村经济快速发展,农业面源污染形势十分严峻.广东省承担的世界银行农业面源污染治理保护性耕作项目,通过在省内的项目示范区域进行水稻和甜玉米的示范试验,探索保护性耕作减少农业面源污染源的作用和方法.项目组设计了免耕和少耕插秧、免耕和少耕直播4种主要模式,投入了50多台套农业机械,经过4个试验点1年的试验,初步结果表明,南方高温潮湿地区水稻和甜玉米生产采用保护性耕作技术是有效果的,所选的农机具大多数是适用的,部分北方旱地机械还需要改进.讨论了广东保护性耕作存在的问题和改进的意见.%Guangdong province is an important agricultural province. The agricultural non-point source pollution situation is very grim in recent years as the population increases and the rural economy grows rapidly. Explo-ration, supported by the world bank agriculture non-point source pollution control-conservation tillage project, has been undertaken in Guangdong province to discover the roles and methods for reducing agricultural non-point source pollution by conservation tillage. The project is conducted in four paddy rice and sweet corn demonstration and experimental sites in the province. Four main models, the no-till and less-till transplanting, no-till and less-till direct seeding, have been designed by the project team. More than 50 sets of agricultural machines have been put into the experiments. After one year's experiments conducted in four sites, prelimi-nary results show that the conservation tillage technology is effective in the paddy rice and sweet corn produc-tion in southern area with high temperature and wet conditions. Most of the selected farm machines are appli-cable. Some of the northern dryland machines need to be improved. The paper discussed the problems and im-provement opinions existing in the Guangdong conservation

  2. Acid rain mitigation experiment shifts a forested watershed from a net sink to a net source of nitrogen.

    Science.gov (United States)

    Rosi-Marshall, Emma J; Bernhardt, Emily S; Buso, Donald C; Driscoll, Charles T; Likens, Gene E

    2016-07-01

    Decades of acid rain have acidified forest soils and freshwaters throughout montane forests of the northeastern United States; the resulting loss of soil base cations is hypothesized to be responsible for limiting rates of forest growth throughout the region. In 1999, an experiment was conducted that reversed the long-term trend of soil base cation depletion and tested the hypothesis that calcium limits forest growth in acidified soils. Researchers added 1,189 kg Ca(2+) ha(-1) as the pelletized mineral wollastonite (CaSiO3) to a 12-ha forested watershed within the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire. Significant increases in the pH and acid-neutralizing capacity of soils and streamwater resulted, and the predicted increase in forest growth occurred. An unanticipated consequence of this acidification mitigation experiment began to emerge a decade later, with marked increases in dissolved inorganic nitrogen (DIN) exports in streamwater from the treated watershed. By 2013, 30-times greater DIN was exported from this base-treated watershed than from adjacent reference watersheds, and DIN exports resulting from this experiment match or exceed earlier reports of inorganic N losses after severe ice-storm damage within the study watershed. The discovery that CaSiO3 enrichment can convert a watershed from a sink to a source of N suggests that numerous potential mechanisms drive watershed N dynamics and provides new insights into the influence of acid deposition mitigation strategies for both carbon cycling and watershed N export.

  3. Soil Biogeochemical Properties and Erosion Source Prediction Model Summary for the Buffalo Bayou Watershed, Houston, Texas

    Science.gov (United States)

    Ahmed, I.

    2015-12-01

    We draw conclusions on the research output and findings from a 4-year multidisciplinary USDA-CBG collaborative program in sustainable integrated monitoring of soil organic carbon (SOC) loss prediction via erosion. The underlying method uses the state-of-the-art stable isotope science of sediment tracing under uncertain hydrologic influences. The research finds are rooted in the (i) application of Bayesian Markov Chain Monte Carlo statistical models to assess the relationship between rainfall-runoff and soil erosion in space and time, (ii) capture of the episodic nature of rainfall events and its role in the spatial distribution of SOC loss from water erosion, (iii) stable isotope composition guided fingerprinting (source and quantity) of eroded soil, and (iv) the creation of an integrated watershed scale statistical soil loss monitoring model driven by spatial and temporal correlation of flow and stable isotope composition. The research theme was successfully applied on the urbanized Buffalo Bayou Watershed in Houston, Texas. The application brought to light novel future research conceptual outlines which will also be discussed in this deliverable to the AGU meeting. These include but not limited to: regional rainfall cluster research, physics of muddy river-bank soil and suspended sediment interaction, and friction & mobility that together make up the plasticity of soil aggregates that control erosion processes and landscape changes in a riparian corridor. References: Ahmed, I., Karim, A., Boutton, T.W., and Strom, K.B. (2013a). "Monitoring Soil Organic Carbon Loss from Erosion Using Stable Isotopes." Proc., Soil Carbon Sequestration, International Conference, May 26-29, Reykjavik, Iceland. Ahmed, I, Bouttom, T.W., Strom, K. B., Karim, A., and Irvin-Smith, N. (2013b). "Soil carbon distribution and loss monitoring in the urbanized Buffalo Bayou watershed, Houston, Texas." Proc., 4th Annual All Investigators Meeting of the North American Carbon Program, February 4

  4. Bibliometric analysis on literatures of Non-Point Source Pollution at A Watershed Scale%流域非点源污染文献计量分析

    Institute of Scientific and Technical Information of China (English)

    马鑫; 闫铁柱; 曹洪涛; 陈少波

    2014-01-01

    非点源污染成为制约中国社会经济和环境可持续发展的重要因素.为了准确掌握流域非点源污染研究的全球状况和前沿动态,客观反映相关国家或地区在该领域的科学能力和科学影响,采用ISI Web of Knowlere的Web of Science引文数据库,选用基本检索方式,以流域非点源的相关术语作为主题检索词,对1900年-2012年之间该库收录的此领域的相关文献进行计量分析.结果表明:从发文量、研究机构和研究人员、高被引文献分析可以看出,美国在此领域成绩卓越,领先于其他国家;在典型机理模型运用方面,SWAT的发文量最多,占模型运用相关文献发文量的52%;国际上该领域最主要的期刊有Journal of The American Water Resources Association、Science of The Total Environment、Journal of Hydrology和Journal of Environmental Quality;中国科学院、北京师范大学和浙江大学的流域非点源污染领域发文量在中国位居前3位.

  5. Review of green roof in controlling unban non-point source pollution%绿色屋顶技术控制城市面源污染应用研究进展

    Institute of Scientific and Technical Information of China (English)

    王书敏; 于慧; 张彬; 邵磊

    2011-01-01

    It has been widely adopted abroad that green roof is an effective mode in controlling Urban Non-point Source Pollution(UNSP),which still belongs to new research fields in China.Based on studies in recent years home and abroad,highlight is given about green roof in controlling unban non-point source pollution from three aspects(i.e.,the reduction and retention of runoff volume,water quality from green roof and the installation method of green roof).Results show that further study is needed for a long time in order to establish the function between stormwater runoff reduction volume and influencing factors;the physical and chemical properties of plants growth media is the key problem affecting runoff water quality.It should follow a wide rang of purposes to install green roofs at home,and the design guidance for green roofs should also be made according to domestic environmental background.The plants growth substrate and the choice of plants are primary problems to be ascertained.%应用绿色屋顶技术控制城市面源污染在欧美国家已得到广泛认同和应用,但在国内尚处于起步阶段.根据国内外最近几年的研究情况,从绿色屋顶消减暴雨径流、绿色屋顶径流水质、绿色屋顶构建方法等方面详细介绍了绿色屋顶技术在控制城市面源污染中的应用研究情况.研究结果表明,建立绿色屋顶暴雨径流消减量与影响因子的映射关系仍需要大量的、长期的研究;植物生长介质的理化性质是影响绿色屋顶径流水质的关键.在国内构建绿色屋顶,应遵循构建目的多元化的原则,逐步建立起适合国内国情的新的绿色屋顶构建导则,其中,植物生长基质搭配方式和植物选取是需要重点明确的问题.

  6. Application of SWMM in the Simulation of Non-Point Source Pollution Load in Urban Residential Area%SWMM模型应用于城市住宅区非点源污染负荷模拟计算

    Institute of Scientific and Technical Information of China (English)

    马晓宇; 朱元励; 梅琨; 张艳军; 张明华

    2012-01-01

    This study was focused on the non-point source pollution loading in a typical urban residential area in Wenzhou City, Zhejiang Province. Based on the SWMM principle, parameters from the literature and field experiments were integrated, and a non-point source pollution calibration model was constructed. Four different rainfall scenarios were designed to analyze the pollution loads and the accumulation process of total suspended solids (TSS) , chemical oxygen demand (CODCr) , total nitrogen (TN) and total phosphorus ( TP). The results showed that the simulated data matched the field-monitored data satisfactorily. The relative errors between the simulated and the true values of all the four parameters were less than 10%. Under' the four rainfall conditions: 1) the highest concentrations of the pollutants were observed within 30-40 minutes; the heavier the rain, the earlier their highest concentrations appeared; 2) higher-intensity rainfall caused more serious pollution to the receiving water bodies than the low-intensity rainfall did.%以温州市典型住宅区非点源污染为对象,基于SWMM(storm water management model)模型的模拟机理,借鉴国内外相关研究的模型参数,结合降雨径流实测数据率定模型参数,将模型“本地化”,构建了基于SWMM模型的研究区非点源污染负荷计算模型,并设计了4种不同降雨情景,分析在不同降雨条件下研究区非点源污染固体悬浮物(TSS)、CODCr、TN和TP的污染负荷量及其累积变化过程.结果表明,构建的SWMM模型的模拟值可以较好地与实测值相吻合,4种污染物模拟的相对误差均小于10%.在设计的4种降雨情景下:①污染物浓度峰值出现在降雨30~40 min内,降雨强度越大,出现浓度峰值的时间越早;②高强度降雨较低强度降雨可对受纳水体造成更大的污染.

  7. Techniques for detecting effects of urban and rural land-use practices on stream-water chemistry in selected watersheds in Texas, Minnesota,and Illinois

    Science.gov (United States)

    Walker, J.F.

    1993-01-01

    Although considerable effort has been expended during the past two decades to control nonpoint-source contamination of streams and lakes in urban and rural watersheds, little has been published on the effectiveness of various management practices at the watershed scale. This report presents a discussion of several parametric and nonparametric statistical techniques for detecting changes in water-chemistry data. The need for reducing the influence of natural variability was recognized and accomplished through the use of regression equations. Traditional analyses have focused on fixed-frequency instantaneous concentration data; this report describes the use of storm load data as an alternative.

  8. Fingerprinting suspended sediment sources using fallout and in-situ radionuclides in forested watershed in Japan

    Science.gov (United States)

    Onda, Y.; Koga, S.; Fukuyama, T.; Hiramatsu, S.

    2004-12-01

    In Japan, forest plantations have became unmanaged because of the lowering of the log price. In unmanaged Hinoki (Japanese cypress, Chamaecyparis obtusa Sieb. et Zucc.) plantations, understory vegetation decreases because of low light conditions, and forest surface become a bare land. The occurrence of Hortonean overlandflow and soil erosion has been reported. Fine surface materials removal from forest floor due to Hortonean overlandflow will affect the downstream environment and fish habitat. However, no studies have been conducted fingerprinting the suspended sediment from unmanaged forest plantations. To study the sources of suspended sediment in forested watershed in Shikoku Island, Japan, the concentration of Cs-137 and Pb-210ex, U and Th decay series radionuclides were analyzed. Soil sampling was conducted in hillslopes in various locations such as landslide scar, surface erosion area in unmanaged Hinoki plantation and forest road, and sampling of deposited sediment in the channel was also conducted in several tributaries. The activities of Cs-137, Pb-210ex, Bi-214 and Tl-208 of soils and fluvial sediments were determined by gamma spectroscopy. We also sampled the suspended sediment by pumping up from the streams, and the time-integrated sediment sampler (Phillips et al, 2000) was also used to collect the various storm event samples. The study area is a 0.33 km2 watershed, upstream of the Shimanto river basin, located about 700 km southwest of Tokyo. High concentrations of Cs-137 and Pb-210ex in suspended sediment were detected, which suggest that the suspended sediments are mostly derived from surface soil of the forests. The concentrations of Cs-137 and Pb-210ex vary between events to events, suggesting that the different sources among the storm events.

  9. 流域非点源污染景观源汇格局遥感解析%Remote sensing parsing on non-point pollution landscape source and assembly pattern in river basin

    Institute of Scientific and Technical Information of China (English)

    张新; 程熙; 李万庆; 罗雷

    2014-01-01

    流域非点源污染景观源汇格局解析是流域水质污染物产生、输运机理认知与有效防治措施制定的重要科学理论基础。该文以充分挖掘流域遥感数据多时空尺度的特征与优势为目标,制定了流域非点源污染景观源汇类型界定方案,提出了像元级、亚像元级以及时序更新的流域非点源污染景观源汇格局遥感解析方法。在此基础上,以福建省九龙江流域为例,对不透水面这一典型流域非点源污染“源”景观2010年空间格局进行了信息提取,并对2000、2005年对应信息进行了时序更新与空间特征分析,结果显示2000-2010年间九龙江流域内不透水面覆盖面积增长了33.38%。该研究可为中国流域非点源污染研究、生态管理与建设提供参考。%The non-point pollution landscape source and assembly pattern of a river basin and its spatio-temporal process analysis are the scientific theoretical bases for studying the pollution, production, transport, prevention, and policy of river water. In this paper, to mine the spatio-temporal character and advantages of remote sensing data, the definition schedule of the landscape of the river basin non-point pollution source and assembly was introduced. The first types of landscape in the river basin included the impervious surface area (ISA) and the pervious surface area. The second types of landscapes in the river basin consisted of 14 different types, including woodland, orchard, road, rural area, town, and paddy field, etc. The river basin non-point pollution landscape source and assembly pattern remote sensing parsing method was subsequently presented at the pixel, sub-pixel, and time-renewing levels. (1) A “globe-local” coupling information extraction model for ISA at the pixel level was established. Through the mining and integration of the spatial information in a local image area, the spectral instability of the whole scale was optimized. The

  10. 潮河流域非点源污染关键区识别及其管理措施研究%IDENTIFICATION OF NON-POINT SOURCE POLLUTION AND ASSESSMENT OF MANAGEMENT MEASURES IN THE CHAO RIVER BASIN

    Institute of Scientific and Technical Information of China (English)

    唐芳芳; 徐宗学; 徐华山

    2012-01-01

    选取SWAT模型,对潮河流域径流、泥沙及非点源污染过程进行模拟.在对模型进行率定和验证的基础上,参照土壤侵蚀模数与国家地表水环境质量标准对土壤侵蚀及总氮污染关键区进行识别.最后分别在土壤侵蚀和总氮污染关键区设置污染控制情景,对控制措施成效进行模拟和评价.结果表明,SWAT模型可以较好地模拟潮河流域水文过程和污染物迁移转化过程;流域20.9%的区域为轻度土壤侵蚀区,39.8%的区域为总氮风险区;梯田、等高耕作、退耕还林还草和减少化肥施用量等措施都不同程度地对非点源污染负荷起到一定的削减效果.%Chao River basin is one of the most important surface water sources for drinking water in Beijing.In recent years,the Chao River basin is facing water scarcity and water quality problem due to the impact of human activities,development of local economy and climate change.The Chao River basin was selected as the study area in this investigation.SWAT model was applied to simulate hydrological cycle and process of nutrient movements and transformation in the Chao River basin.Then critical source areas of soil erosion were identified according to soil erosion modulus,and critical source areas of TN concentration were identified based on the National Environmental Quality Standards for Surface Water.Finally,several scenarios to control non-point source pollution on critical source areas of soil erosion and TN concentration were proposed.Data showed that the performance of calibration and validation for runoff,sediments and nutrients were satisfactory.Mild soil erosion area was 1260.657 km2,accounting for 20.9% of the total basin area,while critical source area of TN was 2405.1 km2,accounting for 39.8% of the total area.Data also showed that the measures including terraces,contour farming,turning farm into forest and grasslands and fertilizer reduction played different reduction role on controlling

  11. Molecular Investigations of Bacteroides as Microbial Source Tracking Tools in Southeast Louisiana Watersheds

    Science.gov (United States)

    Schulz, C. J.; Childers, G. W.; Engel, A. S.

    2006-12-01

    Microbial Source Tracking (MST) is a developing field that is gaining increased attention. MST refers to a host of techniques that discriminates among the origins of fecal material found in natural waters from different sources (e.g. human, livestock, and wildlife) by using microbial indicator species with specificity to only certain host organisms. The development of species-specific molecular markers would allow for better evaluation of public health risks and tracking of nutrient sources impacting a watershed. Although several MST methods have been reported with varying levels of success, few offer general applicability for natural waters due to spatial and temporal constraints associated with these methods. One group of molecular MST markers that show promise for broad environmental applications are molecular 16S rDNA probes for Bacteroides. This method is based on 16S rDNA detection directly from environmental samples without the need for a preliminary cultivation step. In this study we have expanded previous sampling efforts to compile a database of over 1000 partial 16S rRNA Bacteroides genes retrieved from the fecal material of 15 different host species (human, cat, dog, pig, kangaroo). To characterize survival of Bacteroides outside of the host, survival time of the Bacteroides marker was compared to that of E.coli under varying natural environmental conditions (temperature and salinity). Bacteroides displayed a survival curve with shouldering and tailing similar to that of E.coli, but log reduction times differed with treatment. In summary, MST marker stability was identified within host species and the overall Bacteroides community structure correlated to host diet, suggesting that detection of a Bacteroides community could confidently identify fecal contamination point sources. Natural water samples from southeast Louisiana were collected for MST including the Tangipahoa River watershed where the source of fecal contamination has been hotly debated. The

  12. Sources of suspended-sediment flux in streams of the chesapeake bay watershed: A regional application of the sparrow model

    Science.gov (United States)

    Brakebill, J.W.; Ator, S.W.; Schwarz, G.E.

    2010-01-01

    We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According to our model, urban development generates on average the greatest amount of suspended sediment per unit area (3,928 Mg/km2/year), although agriculture is much more widespread and is the greatest overall source of suspended sediment (57 Mg/km2/year). Factors affecting sediment transport from uplands to streams include mean basin slope, reservoirs, physiography, and soil permeability. On average, 59% of upland suspended sediment generated is temporarily stored along large rivers draining the Coastal Plain or in reservoirs throughout the watershed. Applying erosion and sediment controls from agriculture and urban development in areas of the northern Piedmont close to the upper Bay, where the combined effects of watershed characteristics on sediment transport have the greatest influence may be most helpful in mitigating sedimentation in the bay and its tributaries. Stream restoration efforts addressing floodplain and bank stabilization and incision may be more effective in smaller, headwater streams outside of the Coastal Plain. ?? 2010 American Water Resources Association. No claim to original U.S. government works.

  13. Fingerprinting the sources of fluvial sediment using fallout and in-situ radionuclides in forested watershed in Japan

    Science.gov (United States)

    Kato, H.; Onda, Y.; Hiramatsu, S.; Seki, R.

    2003-12-01

    To study the fluvial sediment sources in forested watershed in Shikoku island, Japan, the concentration of Cs-137 and Pb-210ex, U and Th decay series radaionuclides were analyzed. The soil sampling was conducted in hillslopes in various locations such as landslide scar, surface erosion in unmanaged Hinoki (Chamaecyparis obtusa) plantation, and detailed sampling in the channel deposit was also conducted in several tributaries. The activities of Cs-137, Pb-210ex, Bi-214 and Tl-208 of soils and fluvial sediments were determined by gammaspectroscopy. We also analyzed landuse of the watershed and forest logging area and landslide area were measured by air photo interpretation. The study area is Shimanto river basin, located 700 km southwest of Tokyo. The 2270 km2 area watershed ranges in elevation from 0 m to 1485 m above sea level. Low concentration of Cs-137 and Pb-210ex in fine sediments and surface soil at landslide scar suggest that fluvial sediments are derived from surface soil of the landslide scars or from channel walls. The concentrations of Cs-137 and Pb-210ex of fluvial sediment are found to be decrease as the landslide area increases. The data of U and Th decay series radionuclides, Bi-214 and Tl-208, indicate that the sources of fluvial sediment are adjacent to the sampling sites. The results suggest that landslide scar and adjacent to the channel are dominant sources of fluvial sediment in this watershed.

  14. 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

  15. Soil and nutrient retention in winter-flooded ricefields with implications for watershed management

    Science.gov (United States)

    Manley, S.W.; Kaminski, R.M.; Rodrigue, P.B.; Dewey, J.C.; Schoenholtz, S.H.; Gerard, P.D.; Reinecke, K.J.

    2009-01-01

    The ability of water resources to support aquatic life and human needs depends, in part, on reducing nonpoint source pollution amid contemporary agricultural practices. Winter retention of shallow water on rice and other agricultural fields is an accepted management practice for wildlife conservation; however, soil and water conservation benefits are not well documented. We evaluated the ability of four post-harvest ricefield treatment combinations (stubble-flooded, stubble-open, disked-flooded and disked-open) to abate nonpoint source exports into watersheds of the Mississippi Alluvial Valley. Total suspended solid exports were 1,121 kg ha-1 (1,000 lb ac-1) from disked-open fields where rice stubble was disked after harvest and fields were allowed to drain, compared with 35 kg ha-1 (31 lb ac-1) from stubble-flooded fields where stubble was left standing after harvest and fields captured rainfall from November 1 to March 1. Estimates of total suspended solid exports from ricefields based on Landsat imagery and USDA crop data are 0.43 and 0.40 Mg km-2 day-1 in the Big Sunflower and L'Anguille watersheds, respectively. Estimated reductions in total suspended solid exports from ricefields into the Big Sunflower and L'Anguille water-sheds range from 26% to 64% under hypothetical scenarios in which 65% to 100% of the rice production area is managed to capture winter rainfall. Winter ricefield management reduced nonpoint source export by decreasing concentrations of solids and nutrients in, and reducing runoff volume from, ricefields in the Mississippi Alluvial Valley.

  16. Hydrologic analysis for selection and placement of conservation practices at the watershed scale

    Science.gov (United States)

    Wilson, C.; Brooks, E. S.; Boll, J.

    2012-12-01

    When a water body is exceeding water quality standards and a Total Maximum Daily Load has been established, conservation practices in the watershed are able to reduce point and non-point source pollution. Hydrological analysis is needed to place conservation practices in the most hydrologically sensitive areas. The selection and placement of conservation practices, however, is challenging in ungauged watersheds with little or no data for the hydrological analysis. The objective of this research is to perform a hydrological analysis for mitigation of erosion and total phosphorus in a mixed land use watershed, and to select and place the conservation practices in the most sensitive areas. The study area is the Hangman Creek watershed in Idaho and Washington State, upstream of Long Lake (WA) reservoir, east of Spokane, WA. While the pollutant of concern is total phosphorus (TP), reductions in TP were translated to total suspended solids or reductions in nonpoint source erosion and sediment delivery to streams. Hydrological characterization was done with a simple web-based tool, which runs the Water Erosion Prediction Project (WEPP) model for representative land types in the watersheds, where a land type is defined as a unique combination of soil type, slope configuration, land use and management, and climate. The web-based tool used site-specific spatial and temporal data on land use, soil physical parameters, slope, and climate derived from readily available data sources and provided information on potential pollutant pathways (i.e. erosion, runoff, lateral flow, and percolation). Multiple land types representative in the watershed were ordered from most effective to least effective, and displayed spatially using GIS. The methodology for the Hangman Creek watershed was validated in the nearby Paradise Creek watershed that has long-term stream discharge and monitoring as well as land use data. Output from the web-based tool shows the potential reductions for different

  17. 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...

  18. Dynamic phosphorus budget for lake-watershed ecosystems

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; GUO Huai-cheng; WANG Li-jing; DAI Yong-li; ZHANG Xiu-min; LI Zi-hai; HE Bin

    2006-01-01

    Lake eutrophication caused by excess phosphorus (P) loading from point sources (PS) and nonpoint sources (NPS) is a persistent and serious ecological problem in China. A phosphorus budget, based on material flow analysis(MFA) and system dynamic(SD), is proposed and applied for the agriculture-dominated Qionghai Lake watershed located in southwestern China. The MFA-SD approach will not only cover the transporting process of P in the lake-watershed ecosystems, but also can deal with the changes of P budget due to the dynamics of watershed. P inflows include the fertilizer for agricultural croplands, soil losses, domestic sewage discharges, and the atmospheric disposition such as precipitation and dust sinking. Outflows are consisted of hydrologic export, water resources development, fishery and aquatic plants harvesting. The internal P recycling processes are also considered in this paper.From 1988 to 2015, the total P inflows for Lake Qionghai are in a rapid increase from 35.65 to 78.73 t/a, which results in the rising of P concentration in the lake. Among the total P load 2015, agricultural loss and domestic sewage account for 70.60% and 17.27%respectively, directly related to the rapid social-economic development and the swift urbanization. Future management programs designed to reduce P inputs must be put into practices in the coming years to ensure the ecosystem health in the watershed.

  19. Towards a Holistic Model for Simulating Sediment Dynamics at Watershed Scales: Partitioning of Sediment Sources and Uncertainty Quantification

    Science.gov (United States)

    Abban, Benjamin; Papanicolaou, Thanos; Cowles, Kate; Wilson, Christopher; Abaci, Ozan; Wacha, Kenneth

    2016-04-01

    The challenge remains to understand watershed sediment source dynamics for planning and evaluating mitigation measures on anthropogenic activities such as intensive agriculture, which exacerbates soil erosion from the landscape. To this end, our research aims to develop a cross-scale model, capable of simulating sediment transport from the plot scale to the watershed scale while effectively capturing the important feedback effects across the scales. Our approach combines numerical modeling with physical observations and measurements to not only provide a tool capable of mimicking cause and effect relationships, but also capable of quantifying uncertainty related to source dynamics predictions. We present herein a key component of the cross-scale model that quantifies source partitioning and the associated uncertainty. This component is based on a Bayesian un-mixing framework and is particularly useful for watersheds characterized by considerable spatiotemporal heterogeneity. The Bayesian un-mixing framework utilizes two key parameters, namely α and β, that explicitly accounts for spatial origin attributes and the time history of sediments delivered to the watershed outlet, respectively. These parameters are treated probabilistically so as to account for variability in source erosion processes, as well as the delivery times and storage of eroded material within the watershed. The use of Markov Chain Monte Carlo simulations for determining posterior probability density functions in the framework allows uncertainty in source contribution estimates to be quantified naturally as part of the solution process. We demonstrate the utility of the Bayesian un-mixing framework in a predominantly agricultural watershed in the US Midwest known as the Clear Creek Watershed, IA, which is part of the Critical Zone Observatory for Intensively Managed Landscapes (IML-CZO). Stable isotopes of Carbon and Nitrogen are used as tracers since they have been found to be appropriate for

  20. Wash effect of atmospheric trace metals wet deposition and its source characteristic in subtropical watershed in China.

    Science.gov (United States)

    Gao, Yang; Hao, Zhuo; Yang, Tiantian; He, Nianpeng; Tian, Jing; Wen, Xuefa

    2016-10-01

    In order to better understand air pollution in deve-loping regions, such as China, it is important to investigate the wet deposition behavior of atmospheric trace metals and its sources in the subtropical watershed. This paper studies the seasonal change of trace metal concentrations in precipitation and other potential sources in a typical subtropical watershed (Jiazhuhe watershed) located in the downstream of the Yangtze River of China. The results show that typical crustal elements (Al, Fe) and trace element (Zn) have high seasonal variation patterns and these elements have higher contents in precipitation as compared to other metals in Jiazhuhe watershed. In addition, there is no observed Pb in base flow in this study, and the concentration magnitudes of Al, Ba, Fe, Mn, Sr, and Zn in base flow are significantly higher than that of other metals. During different rainfall events, the dynamic export processes are also different for trace metals. The various trace metals dynamic export processes lead to an inconsistent mass first flush and a significant accumulative variance throughout the rainfall events. It is found that in this region, most of the trace metals in precipitation are from anthropogenic emission and marine aerosols brought by typhoon and monsoon.

  1. Using Dual Isotopes and a Bayesian Isotope Mixing Model to Evaluate Nitrate Sources of Surface Water in a Drinking Water Source Watershed, East China

    Directory of Open Access Journals (Sweden)

    Meng Wang

    2016-08-01

    Full Text Available A high concentration of nitrate (NO3− in surface water threatens aquatic systems and human health. Revealing nitrate characteristics and identifying its sources are fundamental to making effective water management strategies. However, nitrate sources in multi-tributaries and mix land use watersheds remain unclear. In this study, based on 20 surface water sampling sites for more than two years’ monitoring from April 2012 to December 2014, water chemical and dual isotopic approaches (δ15N-NO3− and δ18O-NO3− were integrated for the first time to evaluate nitrate characteristics and sources in the Huashan watershed, Jianghuai hilly region, China. Nitrate-nitrogen concentrations (ranging from 0.02 to 8.57 mg/L were spatially heterogeneous that were influenced by hydrogeological and land use conditions. Proportional contributions of five potential nitrate sources (i.e., precipitation; manure and sewage, M & S; soil nitrogen, NS; nitrate fertilizer; nitrate derived from ammonia fertilizer and rainfall were estimated by using a Bayesian isotope mixing model. The results showed that nitrate sources contributions varied significantly among different rainfall conditions and land use types. As for the whole watershed, M & S (manure and sewage and NS (soil nitrogen were major nitrate sources in both wet and dry seasons (from 28% to 36% for manure and sewage and from 24% to 27% for soil nitrogen, respectively. Overall, combining a dual isotopes method with a Bayesian isotope mixing model offered a useful and practical way to qualitatively analyze nitrate sources and transformations as well as quantitatively estimate the contributions of potential nitrate sources in drinking water source watersheds, Jianghuai hilly region, eastern China.

  2. SEDIMENT SOURCES IN AN URBANIZING, MIXED LAND-USE WATERSHED. (R825284)

    Science.gov (United States)

    AbstractThe Issaquah Creek watershed is a rapidly urbanizing watershed of 144 km2 in western Washington, where sediment aggradation of the main channel and delivery of fine sediment into a large downstream lake have raised increasingly frequent concern...

  3. Application of iron and zinc isotopes to track the sources and mechanisms of metal loading in a mountain watershed

    Science.gov (United States)

    Borrok, D.M.; Wanty, R.B.; Ian, Ridley W.; Lamothe, P.J.; Kimball, B.A.; Verplanck, P.L.; Runkel, R.L.

    2009-01-01

    Here the hydrogeochemical constraints of a tracer dilution study are combined with Fe and Zn isotopic measurements to pinpoint metal loading sources and attenuation mechanisms in an alpine watershed impacted by acid mine drainage. In the tested mountain catchment, ??56Fe and ??66Zn isotopic signatures of filtered stream water samples varied by ???3.5??? and 0.4???, respectively. The inherent differences in the aqueous geochemistry of Fe and Zn provided complimentary isotopic information. For example, variations in ??56Fe were linked to redox and precipitation reactions occurring in the stream, while changes in ??66Zn were indicative of conservative mixing of different Zn sources. Fen environments contributed distinctively light dissolved Fe (+0.4???). Acidic drainage from mine wastes contributed heavier dissolved Fe (???+0.5???) and lighter Zn (???+0.2???) isotopes relative to the fen. Upwelling of Fe-rich groundwater near the mouth of the catchment was the major source of Fe (??56Fe ??? 0???) leaving the watershed in surface flow, while runoff from mining wastes was the major source of Zn. The results suggest that given a strong framework for interpretation, Fe and Zn isotopes are useful tools for identifying and tracking metal sources and attenuation mechanisms in mountain watersheds. ?? 2009 Elsevier Ltd.

  4. The Use of LiDAR Elevation Data and Satellite Imagery to Locate Critical Source Areas to Diffuse Pollution in Agricultural Watersheds

    Science.gov (United States)

    Drouin, Ariane; Michaud, Aubert; Thériault, Georges; Beaudin, Isabelle; Rodrigue, Jean-François; Denault, Jean-Thomas; Desjardins, Jacques; Côté, Noémi

    2013-04-01

    In Quebec / Canada, water quality improvement in rural areas greatly depends on the reduction of diffuse pollution. Indeed, point source pollution has been reduced significantly in Canada in recent years by creating circumscribed pits for manure and removing animals from stream. Diffuse pollution differs from point source pollution because it is spread over large areas. In agricultural areas, sediment loss by soil and riverbank erosion along with loss of nutrients (phosphorus, nitrogen, etc.) and pesticides from fields represent the main source of non-point source pollution. The factor mainly responsible for diffuse pollution in agricultural areas is surface runoff occurring in poorly drained areas in fields. The presence of these poorly drained areas is also one of the most limiting factors in crop productivity. Thus, a reconciliation of objectives at the farm (financial concern for farmers) and off-farm concerns (environmental concern) is possible. In short, drainage, runoff, erosion, water quality and crop production are all interconnected issues that need to be tackled together. Two complementary data sources are mainly used in the diagnosis of drainage, surface runoff and erosion : elevation data and multispectral satellite images. In this study of two watersheds located in Québec (Canada), LiDAR elevation data and satellite imagery (QuickBird, Spot and Landsat) were acquired. The studied territories have been partitioned in hydrologic response units (HRUs) according to sub-basins, soils, elevation (topographic index) and land use. These HRUs are afterwards used in a P index software (P-Edit) that calculates the quantities of sediments and phosphorus exported from each HRUs. These exports of sediments and phosphorus are validated with hydrometric and water quality data obtain in two sub-basins and are also compared to soil brightness index derived from multispectral images. This index is sensitive to soil moisture and thus highlights areas where the soil is

  5. Paired Watershed Study of Suspended Sediment Sources in a Watershed Undergoing Road-Building and Timber Harvest, Railroad Gulch, Coastal Northern California, USA

    Science.gov (United States)

    Stubblefield, A. P.; Beach, S.; Harrison, N.; Haskins, M.; MacDonald, L. H.

    2016-12-01

    This presentation reports on the first three years of a paired watershed study to evaluate sediment sources and sediment delivery from roads and timber harvest units in in two small, highly erodible watersheds on the South Fork of the Elk River in coastal Northern California. The study design includes two years of pre-treatment, one year of data collection after road construction, and four years of monitoring after timber harvest in year four. The control watershed is the 1.48 km2 West Branch of Railroad Gulch. The 1.28 km2 East Branch had 0.84 km of new road construction in summer 2015 and 1.52 km of road reopening. 47% of the watershed was selectively logged in summer 2016 using both ground-based and cable logging. Road condition surveys assess rill erosion and delivery to waterways. Headward migration of low order waterways and landslide activation and delivery is assessed with aerial and field surveys. Further field measurements include streamside landslide and channel bank erosion inventories, cross section surveys, and pebble counts. During storm events turbidity synoptic sampling takes place on the main stem of each branch and at small tributary mouths. Monitoring at the outlets of the basins consists of continuous turbidity and discharge recording throughout the year, and automated pump sampling and synoptic sampling for total suspended sediment concentrations during storm events. Rainfall and peak flow analysis, and determination of long term erosion rates with Be-10 methods, completes the study. The initial results indicate that suspended sediment loads from the two basins are strongly correlated, with respectively 38.26 and 49.22 Mg km-2 from the East and West Branch in the exceptionally dry water year of 2014, and 716.07 and 860.55 Mg km-2 in water year 2015. The much higher loading in 2015 is attributed to the higher rainfall, particularly one large storm that triggered debris torrents and streamside failures. Shallow landslides that are hydrologically

  6. Screening and identification of early warning algal species for metal contamination in fresh water bodies polluted from point and non-point sources.

    Science.gov (United States)

    Rai, U N; Dubey, Smita; Shukla, O P; Dwivedi, S; Tripathi, R D

    2008-09-01

    The water bodies of Lucknow, Unnao and Kanpur (U.P.), India polluted through various point and non point sources were found to be either eutrophic or oligotrophic in nature. These water bodies supported a great number of algal diversity, which varied seasonally depending upon the physico-chemical properties of water. Further, the water bodies polluted through non point sources supports diverse algal species, while the water bodies polluted through point sources supports growth of tolerant blue green algae. High biomass producing algal species growing in these water bodies have accumulated significant amount of metals in their tissues. Maximum amount of Fe was found accumulated by species of Oedogonium sp. II (20,523.00 microg g(-1) dw) and Spirogyra sp. I (4,520.00 microg g(-1) dw), while maximum Chromium (Cr) was found accumulated in Phormedium bohneri (2,109.00 microg g(-1) dw) followed by Oscillatoria nigra (1,957.88 microg g(-1) dw) and Oedogonium sp. I (156.00 microg g(-1) dw) and Ni in Ulothrix sp. (495.00 microg g(-1) dw). Results showed that some of these forms growing in polluted environment and accumulating high amounts of toxic metals may be used as bioindicator species, however, their performance in metal contaminated water under different ecological niche is to be ascertained.

  7. Evaluation of a Florida coastal golf complex as a local and watershed source of bioavailable contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Michael A.; Quarles, Robert L.; Dantin, Darrin D.; Moore, James C

    2004-02-01

    Contaminant fate in coastal areas impacted by golf course runoff is not well understood. This report summarizes trace metal, pesticide and PCB residues for colonized periphyton, Ruppia maritima (widgeon grass), Callinectes sapidus Rathbun (blue crabs) and Crassostrea virginica Gemlin (Eastern oyster) collected from areas adjacent to a Florida golf course complex which receive runoff containing reclaimed municipal wastewater. Concentrations of 19 chlorinated pesticides and 18 PCB congeners were usually below detection in the biota. In contrast, 8 trace metals were commonly detected although concentrations were not usually significantly different for biota collected from reference and non-reference coastal areas. Residue concentrations in decreasing order were typically: zinc, arsenic, copper, chromium, lead, nickel, cadmium and mercury. Mean BCF values for the eight trace metals ranged between 160-57 000 (periphyton), 79-11 033 (R. maritima), 87-162 625 (C. virginica) and 12-9800 (C. sapidus). Most trace metal residues in periphyton colonized adjacent to the golf complex, were either similar to or significantly less than those reported for periphyton colonized in nearby coastal areas impacted by urban stormwater runoff and treated municipal and industrial wastewater discharges. Consequently, the recreational complex does not appear to be a major source of bioavailable contaminants locally nor in the immediate watershed based on results for the selected biota.

  8. Coupled effects of natural and anthropogenic controls on seasonal and spatial variations of river water quality during baseflow in a coastal watershed of Southeast China.

    Directory of Open Access Journals (Sweden)

    Jinliang Huang

    Full Text Available Surface water samples of baseflow were collected from 20 headwater sub-watersheds which were classified into three types of watersheds (natural, urban and agricultural in the flood, dry and transition seasons during three consecutive years (2010-2012 within a coastal watershed of Southeast China. Integrating spatial statistics with multivariate statistical techniques, river water quality variations and their interactions with natural and anthropogenic controls were examined to identify the causal factors and underlying mechanisms governing spatiotemporal patterns of water quality. Anthropogenic input related to industrial effluents and domestic wastewater, agricultural activities associated with the precipitation-induced surface runoff, and natural weathering process were identified as the potential important factors to drive the seasonal variations in stream water quality for the transition, flood and dry seasons, respectively. All water quality indicators except SRP had the highest mean concentrations in the dry and transition seasons. Anthropogenic activities and watershed characteristics led to the spatial variations in stream water quality in three types of watersheds. Concentrations of NH(4(+-N, SRP, K(+, COD(Mn, and Cl- were generally highest in urban watersheds. NO3(-N Concentration was generally highest in agricultural watersheds. Mg(2+ concentration in natural watersheds was significantly higher than that in agricultural watersheds. Spatial autocorrelations analysis showed similar levels of water pollution between the neighboring sub-watersheds exhibited in the dry and transition seasons while non-point source pollution contributed to the significant variations in water quality between neighboring sub-watersheds. Spatial regression analysis showed anthropogenic controls played critical roles in variations of water quality in the JRW. Management implications were further discussed for water resource management. This research

  9. Spatial Quantification of Non-Point Source Pollution in a Meso-Scale Catchment for an Assessment of Buffer Zones Efficiency

    Directory of Open Access Journals (Sweden)

    Mikołaj Piniewski

    2015-04-01

    Full Text Available The objective of this paper was to spatially quantify diffuse pollution sources and estimate the potential efficiency of applying riparian buffer zones as a conservation practice for mitigating chemical pollutant losses. This study was conducted using a semi-distributed Soil and Water Assessment Tool (SWAT model that underwent extensive calibration and validation in the Sulejów Reservoir catchment (SRC, which occupies 4900 km2 in central Poland. The model was calibrated and validated against daily discharges (10 gauges, NO3-N and TP loads (7 gauges. Overall, the model generally performed well during the calibration period but not during the validation period for simulating discharge and loading of NO3-N and TP. Diffuse agricultural sources appeared to be the main contributors to the elevated NO3-N and TP loads in the streams. The existing, default representation of buffer zones in SWAT uses a VFS sub-model that only affects the contaminants present in surface runoff. The results of an extensive monitoring program carried out in 2011–2013 in the SRC suggest that buffer zones are highly efficient for reducing NO3-N and TP concentrations in shallow groundwater. On average, reductions of 56% and 76% were observed, respectively. An improved simulation of buffer zones in SWAT was achieved through empirical upscaling of the measurement results. The mean values of the sub-basin level reductions are 0.16 kg NO3/ha (5.9% and 0.03 kg TP/ha (19.4%. The buffer zones simulated using this approach contributed 24% for NO3-N and 54% for TP to the total achieved mean reduction at the sub-basin level. This result suggests that additional measures are needed to achieve acceptable water quality status in all water bodies of the SRC, despite the fact that the buffer zones have a high potential for reducing contaminant emissions.

  10. Modeling sediment and nitrogen export from a rural watershed in eastern Canada using the soil and water assessment tool.

    Science.gov (United States)

    Nafees Ahmad, Hafiz M; Sinclair, Andrew; Jamieson, Rob; Madani, Ali; Hebb, Dale; Havard, Peter; Yiridoe, Emmanuel K

    2011-01-01

    Watershed simulation models can be used to assess agricultural nonpoint-source pollution and for environmental planning and improvement projects. However, before application of any process-based watershed model, the model performance and reliability must be tested with measured data. The Soil and Water Assessment Tool version 2005 (SWAT2005) was used to model sediment and nitrogen loads from the Thomas Brook Watershed, which drains a 7.84 km rural landscape in the Annapolis Valley of Nova Scotia, Canada. The Thomas Brook SWAT model was comprised of 28 subbasins and 265 hydrologic response units, most of them containing agricultural land use, which is the main nonpoint nitrogen source in the watershed. Crop rotation schedules were incorporated into the model using field data collected within Agriculture and Agri-Food Canada's Watershed Evaluation of Beneficial Management Practices program. Model calibration (2004-2006) and validation (2007-2008) were performed on a monthly basis using continuous stream flow, sediment, and nitrogen export measurements. Model performance was evaluated using the coefficient of determination, Nash-Sutcliff efficiency (NSE), and percent bias (PBIAS) statistics. Study results show that the model performance was satisfactory (NSE > 0.4; > 0.5) for stream flow, sediment, nitrate-nitrogen, and total nitrogen simulations. Annual corn, barley, and wheat yields were also simulated well, with PBIAS values ranging from 0.3 to 7.2%. This evaluation of SWAT demonstrated that the model has the potential to be used as a decision support tool for agricultural watershed management in Nova Scotia.

  11. A novel modelling framework to prioritize estimation of non-point source pollution parameters for quantifying pollutant origin and discharge in urban catchments.

    Science.gov (United States)

    Fraga, I; Charters, F J; O'Sullivan, A D; Cochrane, T A

    2016-02-01

    Stormwater runoff in urban catchments contains heavy metals (zinc, copper, lead) and suspended solids (TSS) which can substantially degrade urban waterways. To identify these pollutant sources and quantify their loads the MEDUSA (Modelled Estimates of Discharges for Urban Stormwater Assessments) modelling framework was developed. The model quantifies pollutant build-up and wash-off from individual impervious roof, road and car park surfaces for individual rain events, incorporating differences in pollutant dynamics between surface types and rainfall characteristics. This requires delineating all impervious surfaces and their material types, the drainage network, rainfall characteristics and coefficients for the pollutant dynamics equations. An example application of the model to a small urban catchment demonstrates how the model can be used to identify the magnitude of pollutant loads, their spatial origin and the response of the catchment to changes in specific rainfall characteristics. A sensitivity analysis then identifies the key parameters influencing each pollutant load within the stormwater given the catchment characteristics, which allows development of a targeted calibration process that will enhance the certainty of the model outputs, while minimizing the data collection required for effective calibration. A detailed explanation of the modelling framework and pre-calibration sensitivity analysis is presented.

  12. Evaluation of Land Use, Land Management and Soil Conservation Strategies to Reduce Non-Point Source Pollution Loads in the Three Gorges Region, China.

    Science.gov (United States)

    Strehmel, Alexander; Schmalz, Britta; Fohrer, Nicola

    2016-11-01

    The construction of the Three Gorges Dam in China and the subsequent impoundment of the Yangtze River have induced a major land use change in the Three Gorges Reservoir Region, which fosters increased inputs of sediment and nutrients from diffuse sources into the water bodies. Several government programs have been implemented to mitigate high sediment and nutrient loads to the reservoir. However, institutional weaknesses and a focus on economic development have so far widely counteracted the effectiveness of these programs. In this study, the eco-hydrological model soil and water assessment tool is used to assess the effects of changes in fertilizer amounts and the conditions of bench terraces in the Xiangxi catchment in the Three Gorges Reservoir Region on diffuse matter releases. With this, the study aims at identifying efficient management measures, which should have priority. The results show that a reduction of fertilizer amounts cannot reduce phosphorus loads considerably without inhibiting crop productivity. The condition of terraces in the catchment has a strong impact on soil erosion and phosphorus releases from agricultural areas. Hence, if economically feasible, programmes focusing on the construction and maintenance of terraces in the region should be implemented. Additionally, intercropping on corn fields as well as more efficient fertilization schemes for agricultural land were identified as potential instruments to reduce diffuse matter loads further. While the study was carried out in the Three Gorges Region, its findings may also beneficial for the reduction of water pollution in other mountainous areas with strong agricultural use.

  13. Evaluation of Land Use, Land Management and Soil Conservation Strategies to Reduce Non-Point Source Pollution Loads in the Three Gorges Region, China

    Science.gov (United States)

    Strehmel, Alexander; Schmalz, Britta; Fohrer, Nicola

    2016-11-01

    The construction of the Three Gorges Dam in China and the subsequent impoundment of the Yangtze River have induced a major land use change in the Three Gorges Reservoir Region, which fosters increased inputs of sediment and nutrients from diffuse sources into the water bodies. Several government programs have been implemented to mitigate high sediment and nutrient loads to the reservoir. However, institutional weaknesses and a focus on economic development have so far widely counteracted the effectiveness of these programs. In this study, the eco-hydrological model soil and water assessment tool is used to assess the effects of changes in fertilizer amounts and the conditions of bench terraces in the Xiangxi catchment in the Three Gorges Reservoir Region on diffuse matter releases. With this, the study aims at identifying efficient management measures, which should have priority. The results show that a reduction of fertilizer amounts cannot reduce phosphorus loads considerably without inhibiting crop productivity. The condition of terraces in the catchment has a strong impact on soil erosion and phosphorus releases from agricultural areas. Hence, if economically feasible, programmes focusing on the construction and maintenance of terraces in the region should be implemented. Additionally, intercropping on corn fields as well as more efficient fertilization schemes for agricultural land were identified as potential instruments to reduce diffuse matter loads further. While the study was carried out in the Three Gorges Region, its findings may also beneficial for the reduction of water pollution in other mountainous areas with strong agricultural use.

  14. Does discharge time source correspond to its geographic source in hydrograph separations? Toward identification of dominant runoff processes in a 300 square kilometer watershed

    Directory of Open Access Journals (Sweden)

    Y. Yokoo

    2014-09-01

    Full Text Available This study compared a time source hydrograph separation method to a geographic source separation method, to assess if the two methods produced similar results. The time source separation of a hydrograph was performed using a numerical filter method and the geographic source separation was performed using an end-member mixing analysis employing hourly discharge, electric conductivity, and turbidity data. These data were collected in 2006 at the Kuroiwa monitoring station on the Abukuma River, Japan. The results of the methods corresponded well in terms of both surface flow components and inter-flow components. In terms of the baseflow component, the result of the time source separation method corresponded with the moving average of the baseflow calculated by the geographic source separation method. These results suggest that the time source separation method is not only able to estimate numerical values for the discharge components, but that the estimates are also reasonable from a geographical viewpoint in the 3000 km2 watershed discussed in this study. The consistent results obtained using the time source and geographic source separation methods demonstrate that it is possible to characterize dominant runoff processes using hourly discharge data, thereby enhancing our capability to interpret the dominant runoff processes of a watershed using observed discharge data alone.

  15. “双重失灵”视角下我国农业面源污染的法律规制%Legal Regulation of the Agricultural Non-point Source Pollution in the Perspective of “Double Failure”

    Institute of Scientific and Technical Information of China (English)

    祝创杰

    2016-01-01

    来自化肥、农药、农膜、畜禽养殖等污染源的农业面源污染已经成为我国水污染的最大污染源。现行立法对农业面源污染的规制在指导思想、具体内容和立法技术等方面仍存在一些不足,而这些不足又是忽略或缺乏经济法的思维方式所致。我国农业面源污染恶化是市场失灵和政府失灵共同作用的结果。克服“双重失灵”,有效规制面源污染,可以通过完善环境税收体系,增设生态税、建立排污权交易制度等经济法的调整手段实现。%The Agricultural Non-point Source Pollution (ANPSP),which is caused by pollution source like chemical fertilizers,pesticides,agricultural film and livestock breeding,has already be-come the largest source of pollution of our country's water pollution.The regulation of The Agricultural Non-point Source Pollution given by current legislation still has some deficiencies in guiding ideology, concrete content and legislative technique.This is caused by neglecting or lacking the thinking mode of economic law.The root cause of the deterioration of The Agricultural Non-point Source Pollution in China is the combined action of market failure and government failure.The task of overcoming “double failure”and controlling The Agricultural Non-point Source Pollution can be finished by using adjust-ment methods of economic law.The methods may include improving the environmental tax system, adding ecological taxation and establishing emission trading system.

  16. Agricultural nonpoint source pollution: prevention and estimate methods; L'inquinamento di origine agricola: quali strumenti di prevenzione e stima?

    Energy Technology Data Exchange (ETDEWEB)

    Caffarelli, V.; Rapagnani, M.R.; Triolo, L. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Innovazione

    1999-07-01

    Non point source pollutants, such as pesticides and fertilizers derived from agricultural activities, are recognized as an important threat to environment and human health. To prevent the adverse effects of these agrochemicals it is necessary to provide growers and decision makers with easy-to-use information. Attempts have been made to put information on pesticides environmental and health effects into a formula that could summarize, in a single number, these effects. However a single number could be misleading because of the lack of information on chemical-physical parameters and the difficulty to evaluate the relative importance of various environmental and health effects. As an alternative it is here proposed an approach based on schedule containing information, for each pesticides, such as short and long term effects on human health, environmental fate and degradation time, capacity to bio accumulate, toxicity of degradation products. Using information in the schedule, decision makers could make more circumstantiate choices and could program the best agricultural actions under particular environmental circumstances with less impact on man and environment. [Italian] L'inquinamento diffuso derivante dall'uso dei fertilizzanti e dei pesticidi in agricoltura, rappresenta un rischio rilevante per l'ambiente e la salute umana. Al fine di prevenire tale rischio e' necessario fornire a coloro che gestiscono e pianificano le attivita' agricole informazioni facilmente comprensibili, mirate a ridurre o eliminare gli effetti indesiderati derivanti dai prodotti agrochimici. Tentativi sono stati fatti per sviluppare metodologie che sintetizzino queste informazioni in un indice numerico in modo da stilare una graduatoria di pericolosita' dei singoli prodotti. Si propone, in questo lavoro, un approccio basato sulla elaborazione di schede, per ogni principio attivo, che contengono una serie di informazioni quali gli effetti a breve e lungo termine

  17. 我国农业面源污染现状及其对策研究%Review of the current situation and control countermeasures in agricultural non-point source pollution control in China

    Institute of Scientific and Technical Information of China (English)

    李自林

    2013-01-01

    随着我国经济的快速发展,农业面源污染已成为我国环境污染的主要原因之一。农业面源污染制约农业可持续发展,已成为亟待解决的环境问题。目前,造成农业面源污染的原因主要是化肥农药的过量施用和流失,畜禽和水产养殖业污染,水土流失,作物秸秆大量废弃以及农膜污染。农业面源污染具有分散性、广泛性、随机性等特征,对土壤、水体、大气造成负面影响。本文针对农业面源污染问题,从生物、物理、化学以及农业管理等角度提出了相应的防治对策及措施,以期有效治理农业面源污染,保护环境,促进农业可持续发展。%Agricultural non-point source pollution is the main factor to the environmental pollution in rural China now with the development of economy in China .It has gained the attention of the government and scientist in the country , and also is the main factor to restrain the agricultural sustainable development .At present ,the reasons are list as follow :chemical fertilizer and pesticide and excessive application ;Livestock and aquatic products pollution ;soil erosion ;a ma-jority of strews abandoned ;agricultural plastic film pollution .It has the characteristics of dispensability ,universality and randomness ,which have negative effects on soil ,water and air .In terms of biological chemistry and physics and agricul-tural management ,this paper proposes countermeasures to control agricultural non -point source pollution ,protect the environment ,and promote the sustainable development of agriculture .

  18. 宁夏农村面源污染现状调查分析结果初报%Preliminary Report on Investigation and Analysis Result of Current Situation of Rural Non-point Source Pol ution in Ningxia

    Institute of Scientific and Technical Information of China (English)

    杨晓娟; 靳军良; 王金保

    2014-01-01

    通过调查监测,宁夏农村面源污染的主要来源集中体现在化肥污染、农药污染、畜禽粪便污染、农膜污染及农村生活污染5个方面,但其影响和污染主要表现在对水环境和土壤环境的污染上。其中,对水环境的污染形式则是通过地表径流和地下淋溶把过剩的氮、磷、有机农药、无机盐等带到地表水和地下水中,致使地表水富营养化,破环水生态环境,鱼虾难以生存。对土壤环境的污染形式是通过农业投入品超量施入,在改变土壤物理性状、破环土壤通透性、造成土壤板结、粘结的同时,造成重金属离子和病原菌的积累,给农产品质量安全带来危害。%Based on an investigation and monitoring,the main sources of Ningxia rural non-point source pollution includes the five aspects of chemical fertilizer pollution, pesticide pollution, livestock and poultry manure pollution, agricultural plastic film pollution and rural domestic pollution. But the impact and pollution were mainly manifested in the pollution of water envi-ronment and soil environment. The form of pollution of the water environment was bringing excess nitrogen, phosphorus, or-ganic pesticides and inorganic salt to the surface water and underground water by the surface runoff and underground leach-ing,it caused the surface water eutrophication,the destruction of the aquatic ecological environment and made the fish and shrimp hard to survive. The form of pollution of the soil environment was changing the soil physical characteristic, destroying the soil permeability, causing soil compaction and bond,and causing the accumulation of heavy metal ions and pathogenic bacteria by excessive application of agricultural inputs, and it brought harms to the quality and safety of agricultural products.

  19. Watershed-based point sources permitting strategy and dynamic permit-trading analysis.

    Science.gov (United States)

    Ning, Shu-Kuang; Chang, Ni-Bin

    2007-09-01

    Permit-trading policy in a total maximum daily load (TMDL) program may provide an additional avenue to produce environmental benefit, which closely approximates what would be achieved through a command and control approach, with relatively lower costs. One of the important considerations that might affect the effective trading mechanism is to determine the dynamic transaction prices and trading ratios in response to seasonal changes of assimilative capacity in the river. Advanced studies associated with multi-temporal spatially varied trading ratios among point sources to manage water pollution hold considerable potential for industries and policy makers alike. This paper aims to present an integrated simulation and optimization analysis for generating spatially varied trading ratios and evaluating seasonal transaction prices accordingly. It is designed to configure a permit-trading structure basin-wide and provide decision makers with a wealth of cost-effective, technology-oriented, risk-informed, and community-based management strategies. The case study, seamlessly integrating a QUAL2E simulation model with an optimal waste load allocation (WLA) scheme in a designated TMDL study area, helps understand the complexity of varying environmental resources values over space and time. The pollutants of concern in this region, which are eligible for trading, mainly include both biochemical oxygen demand (BOD) and ammonia-nitrogen (NH3-N). The problem solution, as a consequence, suggests an array of waste load reduction targets in a well-defined WLA scheme and exhibits a dynamic permit-trading framework among different sub-watersheds in the study area. Research findings gained in this paper may extend to any transferable dynamic-discharge permit (TDDP) program worldwide.

  20. Assessing the Source-to-Stream Transport of Benzotriazoles during Rainfall and Snowmelt in Urban and Agricultural Watersheds.

    Science.gov (United States)

    Parajulee, Abha; Lei, Ying Duan; De Silva, Amila O; Cao, Xiaoshu; Mitchell, Carl P J; Wania, Frank

    2017-04-07

    While benzotriazoles (BTs) are ubiquitous in urban waters, their sources and transport remain poorly characterized. We aimed to elucidate the origin and hydrological pathways of BTs in Toronto, Canada, by quantifying three BTs, electrical conductivity, and δ(18)O in high-frequency streamwater samples taken during two rainfall and one snowmelt event in two watersheds with contrasting levels of urbanization. Average concentrations of total BTs (∑BT) were 1.3 to 110 times higher in the more urbanized Mimico Creek watershed relative to the primarily agricultural and suburban Little Rouge Creek. Strong correlations between upstream density of major roads and total BT concentrations or BT composition within all events implicate vehicle fluids as the key source of BTs in both watersheds. Sustained historical releases of BTs within the Mimico Creek watershed have likely led to elevated ∑BT in groundwater, with elevated concentrations observed during baseflow that are diluted by rainfall and surface runoff. In contrast, relatively constant concentrations, caused by mixing of equally contaminated baseflow and rainfall/surface runoff, are observed in the Little Rouge Creek throughout storm hydrographs, with an occasional first flush occurring at a subsite draining suburban land. During snowmelt, buildup of BTs in roadside snowpiles and preferential partitioning of BTs to the liquid phase of a melting snowpack leads to early peaks in ∑BT in both streams, except the sites in the Little Rouge Creek with low levels of vehicle traffic. Overall, a history of BT release and land use associated with urbanization have led to higher levels of BTs in urban areas and provide a glimpse into future BT dynamics in mixed use, (sub)urbanizing areas.

  1. Optimization of Policy and Management Service System on Control of Rural Non-Point Source Pollution-A Case Study of the Rural Area of Shanghai%农村面源污染治理的政策与管理服务体系优化——以上海郊区农村为例

    Institute of Scientific and Technical Information of China (English)

    黄文芳; 沈哲

    2012-01-01

    It is a common view that control of rural non-point source pollution is not only a technology issue, but also a management system issue. So hard currently it has become a hot spot and a hard nut as well to probe and consummate the policy, management and service system for control of rural non-point source pollution. Selecting the rural suburbs of Shanghai for case study, the status quo of the rural non-point source pollution and its management have been analyzed and summarized. While affirming the effect of the current work on pollution management, the limitations of the work are discerned and it was pointed out that inharmony between the agriculture development policy and the environmental protection policy and the lag of the management mechanism and service system behind the change in the rural development model are the basic causes. To counter the major contributors of the rural non-point source pollution, i. e. chemical fertilizers, pesticides , livestock excretes and rural domestic sewage, countermeasures and suggestions are presented for management of the pollution from the aspects of modification of the agricultural subsidization system, reconfiguration and implementation of the rural multi-value system and consummation of agricultural production service system.%农村面源污染控制不仅是技术问题,也是管理体制与机制问题,探讨并完善农村面源污染治理的政策、管理与服务体系已成为当前研究的热点与难点.以上海郊区农村为例,梳理总结农村面源污染及其控制现状;在肯定当前治理效果的同时,识别其局限性,指出农业政策与环境保护政策的不协调、农村发展模式转变下制度与服务体系的相对滞后是根本原因;针对当前农村面源污染重要的贡献者——化肥、农药、畜禽粪便以及农村生活污水,分别从改革农业补贴制度、重构实现农村多重价值的制度以及完善农业生产服务体系等方面给出了治理的对策与建议.

  2. Review on super absorbent polymer application for improving fertilizer efficiency and controlling agricultural non-point source pollutions%高吸水树脂保水剂提高肥效及减少农业面源污染

    Institute of Scientific and Technical Information of China (English)

    廖人宽; 杨培岭; 任树梅

    2012-01-01

    Super absorbent polymer (SAP) is a new type of multifunctional material in drought resistant and pollution control. SAP can quickly absorb water and fertilizer for increasing soil crumb structure and porosity, restraining soil evaporation, promoting crop physiological function and reducing fertilizer loss, so as to result in significant improvement of water and fertilizer use efficiency and marked reduction in fertilizer pollution. In recent years, SAP has been widely used in agricultural nonpoint source pollution control as a chemical product of absorbing and storing water and fertilizer. The paper expounds its acting mechanism and efficiency in controlling pollution, introduces the researches on its main antifouling function, and emphatically summarizes the researches of SAP application in agricultural production and the development of agricultural antifouling absorbent agent. In the end, the problems existing in the field are discussed and the future research fields are proposed.%高吸水树脂(保水剂)是一种新型多功能抗旱、防污材料,能够快速吸持水肥,增加土壤团粒结构和孔隙度,抑制土面蒸发,提升作物生理机能,减少养分淋失,从而达到提高水肥利用效率和减少肥料污染的作用.近年来,保水剂在农业面源污染防治方面得到了越来越广泛的应用.该文阐述了保水剂的防污作用机理及效能,介绍了保水剂主要防污作用方面的研究,重点对保水剂在农业生产上的防污应用及农用防污型保水剂的研制进行了综述,最后分析了保水剂在农业防污应用和研究过程中存在的问题,提出了保水剂未来进行防污应用的研究方向.

  3. Phosphorus removal by the multipond system sediments receiving agricultural drainage in a headstream watershed

    Institute of Scientific and Technical Information of China (English)

    FU Qiang; YIN Cheng-qing; MA Yun

    2005-01-01

    Wetland systems in headstream watersheds are important to control the nonpoint source pollutant phosphorus. Experiments were conducted using intact sediment-water columns obtained from the multipond system in Liuchahe watershed of Chaohu Lake to determine its capacity to retain P. It was found that pond sediments had strong P retention ability. For the Hill pond, Village pond and Rice pond, their retention coefficient(A) were 288.3, 279.2 and 260.8 L/m2 , respectively. The equilibrium P concentration(EPCw) were 0.016, 0.028 and 0.018 mg/L, respectively. The Hill pond indicated the highest P retention ability. P retained in the pond sediments indicated high stable degree. P removal from the overlying water column into the pond sediments followed a first-order kinetic model. Under the experimental hydrological conditions, the retention time had a positive correlation with the P loading. The multipond system could provide enough retention time to retain P in drainage runoffs. At the P levels evaluated, the sediments of the multipond system are effective sinks to retainP from nonpoint source runoffs.

  4. FECAL SOURCE TRACKING BY ANTIBIOTIC RESISTANCE ANALYSIS ON A RURAL WATERSHED

    Science.gov (United States)

    The Turkey Creek watershed located in northwestern Oklahoma, sustains approximately 40000 head of livestock. In addition, the stream receives partially-treated municipal waste from various towns. E. coli was enumerated quarterly and counts beyond EPA limit were found in spring an...

  5. FECAL SOURCE TRACKING BY ANTIBIOTIC RESISTANCE ANALYSIS ON A RURAL WATERSHED

    Science.gov (United States)

    The Turkey Creek watershed located in northwestern Oklahoma, sustains approximately 40000 head of livestock. In addition, the stream receives partially-treated municipal waste from various towns. E. coli was enumerated quarterly and counts beyond EPA limit were found in spring an...

  6. Fine sediment sources in coastal watersheds with uplifted marine terraces in northwest Humboldt County, California

    Science.gov (United States)

    Stephen Sungnome Madrone; Andrew P. Stubblefield

    2012-01-01

    Erosion in the Mill and Luffenholtz Creek watersheds in Humboldt County, California, with their extensive clay soils, can lead to high turbidity levels in receiving bodies of water, increasing the costs of treating water for domestic water supplies. Detailed road and erosion surveys and monitoring of suspended sediment, discharge, and turbidity levels in Mill Creek (3....

  7. Variations in source apportionments of nutrient load among seasons and hydrological years in a semi-arid watershed: GWLF model results.

    Science.gov (United States)

    Du, Xinzhong; Li, Xuyong; Zhang, Wangshou; Wang, Huiliang

    2014-05-01

    Quantifying source apportionments of nutrient load and their variations among seasons and hydrological years can provide useful information for watershed nutrient load reduction programs. There are large seasonal and inter-annual variations in nutrient loads and their sources in semi-arid watersheds that have a monsoon climate. The Generalized Watershed Loading Function model was used to simulate monthly nutrient loads from 2004 to 2011 in the Liu River watershed, Northern China. Model results were used to investigate nutrient load contributions from different sources, temporal variations of source apportionments and the differences in the behavior of total nitrogen (TN) and total phosphorus (TP). Examination of source apportionments for different seasons showed that point sources were the main source of TN and TP in the non-flood season, whereas contributions from diffuse sources, such as rural runoff, soil erosion, and urban areas, were much higher in the flood season. Furthermore, results for three typical hydrological years showed that the contribution ratios of nutrient loads from point sources increased as streamflow decreased, while contribution ratios from rural runoff and urban area increased as streamflow increased. Further, there were significant differences between TN and TP sources on different time scales. Our findings suggest that priority actions and management measures should be changed for different time periods and hydrological conditions, and that different strategies should be used to reduce loads of nitrogen and phosphorus effectively.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Occurrence of dissolved solids, nutrients, atrazine, and fecal coliform bacteria during low flow in the Cheney Reservoir watershed, south-central Kansas, 1996

    Science.gov (United States)

    Christensen, V.G.; Pope, L.M.

    1997-01-01

    A network of 34 stream sampling sites was established in the 1,005-square-mile Cheney Reservoir watershed, south-central Kansas, to evaluate spatial variability in concentrations of selected water-quality constituents during low flow. Land use in the Cheney Reservoir watershed is almost entirely agricultural, consisting of pasture and cropland. Cheney Reservoir provides 40 to 60 percent of the water needs for the city of Wichita, Kansas. Sampling sites were selected to determine the relative contribution of point and nonpoint sources of water-quality constituents to streams in the watershed and to identify areas of potential water-quality concern. Water-quality constituents of interest included dissolved solids and major ions, nitrogen and phosphorus nutrients, atrazine, and fecal coliform bacteria. Water from the 34 sampling sites was sampled once in June and once in September 1996 during Phase I of a two-phase study to evaluate water-quality constituent concentrations and loading characteristics in selected subbasins within the watershed and into and out of Cheney Reservoir. Information summarized in this report pertains to Phase I and was used in the selection of six long-term monitoring sites for Phase II of the study. The average low-flow constituent concentrations in water collected during Phase I from all sampling sites was 671 milligrams per liter for dissolved solids, 0.09 milligram per liter for dissolved ammonia as nitrogen, 0.85 milligram per liter for dissolved nitrite plus nitrate as nitrogen, 0.19 milligram per liter for total phosphorus, 0.20 microgram per liter for dissolved atrazine, and 543 colonies per 100 milliliters of water for fecal coliform bacteria. Generally, these constituents were of nonpoint-source origin and, with the exception of dissolved solids, probably were related to agricultural activities. Dissolved solids probably occur naturally as the result of the dissolution of rocks and ancient marine sediments containing large salt

  10. Seasonal Variation in Hydrology Driving Shifts in Sources of Nitrate in an Agricultural Dominant Semi-arid Watershed

    Science.gov (United States)

    Moon Nielsen, L. G.; Orr, C. H.

    2010-12-01

    In the South Fork Palouse River in the semi-arid region of Eastern Washington State, surface water hydrology is driven by seasonal variation in precipitation, with peak surface water flow and highest Nitrate values observed from January to April, and lowest surface flows and corresponding lower Nitrate concentrations observed from June to August. Land-use in the watershed is predominantly non-irrigated cropland (82%) fertilized by synthetic fertilizer, with an additional 8% of land in urban areas. Due to the prevalence of anthropogenically influenced land in the watershed, Nitrate concentrations measured in streams here are chronically elevated above natural levels. Typically in an area that is dominated by agriculture, the source of Nitrate in surface waters draining agricultural land would be predicted to be synthetic fertilizer. However it is important to consider the impacts seasonal hydrological conditions can have upon Nitrate sources and flow paths. We investigated how Nitrate sources in Palouse streams and rivers changed seasonally to address the hypothesis that seasonal variation in precipitation shifts the dominant sources of Nitrate in surface waters. We based our determination of nitrogen source on the results from dual stable isotope analysis of Nitrate using the denitrifier method. Sampling was done at 7 locations of increasing catchment area along the South Fork Palouse River and tributary streams. Sampling site catchment area varied one order of magnitude from 70.9 to 717.4 km2. Surface waters at yearly low flow during the summer season indicated δ15N-Nitrate and δ18O-Nitrate ranging within generally accepted values to indicate Nitrate derived from animal and human waste. These can be attributed to waste water discharge from the urban areas in the watershed. Yearly hydrologic data suggests that during the winter season, increased precipitation causes a shift in δ15N-Nitrate and δ18O-Nitrate to values typically observed in sources derived from

  11. Tracing sources of suspended sediment in a Canadian agricultural watershed using a Bayesian model: Testing different groups of fingerprinting properties

    Science.gov (United States)

    Gaspar, Leticia; Owens, Philip; Petticrew, Ellen; Lobb, David; Koiter, Alexander; Reiffarth, Dominic; Barthod, Louise; Liu, Kui; Martinez-Carreras, Nuria

    2015-04-01

    An understanding of sediment redistribution processes and the main sediment sources within a watershed is needed to support catchment management strategies, to control soil erosion processes, and to preserve water quality and ecological status. The fingerprinting technique is increasingly recognised as a method for establishing the source of the sediment transported within a catchment. However, the different behaviour of the various fingerprinting properties has been recognised as a major limitation of the technique, and the uncertainty associated with tracer selection has to be addressed. Do the different properties give similar results? Can we combine different groups of tracers? This study aims to compare and evaluate the differences between fingerprinting predictions provided by a Bayesian mixing model using different groups of tracer properties for use in sediment source identification. We are employing fallout radionuclides (137Cs, 210Pbex) and geochemical elements as conventional fingerprinting properties, and colour parameters and compound-specific stable isotopes (CSSIs) as emerging properties; both alone and in combination. These fingerprinting properties are being used to determine the proportional contributions of fine sediment in the South Tobacco Creek Watershed, an agricultural catchment located in south-central Manitoba in Canada. We present preliminary results to evaluate the use of different statistical procedures to increase the accuracy of fingerprinting outputs and establish protocols for the selection of appropriate fingerprint properties.

  12. 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.

  13. 苏州市东山镇池塘养蟹面源污染现状及控制%Current status and control strategies of non-point source pollution from pond aquaculture in Dongshan town of Suzhou

    Institute of Scientific and Technical Information of China (English)

    宋学宏; 郭培红; 孙丽萍; 朱江

    2011-01-01

    结合全国污染源普查活动,以苏州市养殖老区东山镇养殖池塘为典型,调查其现行养殖模式、经济效益、养殖污染状况.调查结果显示,东山镇现有养殖面积为2253.33hm2,主养品种为河蟹.1个养殖周期中,养殖池塘通过沟渠排入外界的TN、TP含量分别平均为21.25kg/hm2、2.34kg/hm2;密度为9000只/hm2的低密度养殖池外排的TN含量为16.79kg/hm2,而无TP排出.分析苏州地区池塘养殖产生水环境污染的主要原因,从池塘管理体制改革、科学生态养殖技术及养殖尾水处理等方面探讨池塘养殖污水零排放技术,为苏州市养殖业面源污染的控制提供对策和措施.%Combining with national census of pollution sources and using large-scale pond aquaculture in Dongshan town in Suzhou as a case study, the current cultural modes, economic benefits, and aquaculture pollution were surveyed. The results showed that there were 2 253.33 hm2 of aquaculture in Dongshan town, and the Chinese mitten crab was the main specie. In a single aquaculture period, the discharged total nitrogen (TN) and total phosphorus (TP) from pounds to outside through canals and ditches were on average 21.25 kg/hm2 and 2.34 kg/hm2 respectively. However, in a lowdensity crab raising pond of 9000 ind/hm2, the discharged TN was 16.79 kg/hm2, and no TP was found to be discharged.Based on the case study, the main reasons for the water environment pollution by pond aquaculture were analyzed, and the zero discharge technologies for the waste water of pond aquaculture were discussed from aspects of the management system reform for pond, the scientific and ecological raising technique, and the aquaculture wastewater treatment. The possible strategies and countermeasures for controlling the aquacultural non-point source pollution in Suzhou were also provided.

  14. Using Remote Sensing to Identify Changes in Land Use and Sources of Fecal Bacteria to Support a Watershed Transport Model

    Directory of Open Access Journals (Sweden)

    Sean Butler

    2014-07-01

    Full Text Available The contamination of shellfish harvesting areas by fecal bacteria in the Annapolis Basin of Nova Scotia, Canada, is a recurring problem which has consequences for industry, government, and local communities. This study contributes to the development of an integrated water quality forecasting system to improve the efficiency and effectiveness of industry management. The proposed integrated forecasting framework is composed of a database containing contamination sources, hydrodynamics of the Annapolis Basin, Escherichia coli (E. coli loadings and watershed hydrology scenarios, coupled with environmental conditions of the region (e.g., temperature, precipitation, evaporation, and ultraviolet light. For integration into this framework, this study presents a viable methodology for assessing the contribution of fecal bacteria originating from a watershed. The proposed methodology investigated the application of high resolution remote sensing, coupled with the commercially available product, MIKE 11, to monitor watershed land use and its impact on water quality. Remote sensing proved to be an extremely useful tool in the identification of sources of fecal bacteria contamination, as well as the detection of land use change over time. Validation of the MIKE 11 model produced very good agreement (R2 = 0.88, E = 0.85 between predicted and observed river flows, while model calibration of E. coli concentrations showed fair agreement (R2 = 0.51 and E = 0.38 between predicted and observed values. A proper evaluation of the MIKE 11 model was constrained due to limited water sampling. However, the model was very effective in predicting times of high contamination for use in the integrated forecasting framework, especially during substantial precipitation events.

  15. Contribution of Leaf Litter to Nutrient Export during Winter Months in an Urban Residential Watershed.

    Science.gov (United States)

    Bratt, Anika R; Finlay, Jacques C; Hobbie, Sarah E; Janke, Benjamin D; Worm, Adam C; Kemmitt, Kathrine L

    2017-03-03

    Identification of nonpoint sources of nitrogen (N) and phosphorus (P) in urban systems is imperative to improving water quality and better managing eutrophication. Winter contributions and sources of annual N and P loads from urban watersheds are poorly characterized in northern cities because monitoring is often limited to warm-weather periods. To determine the winter export of N and P, we monitored stormwater outflow in a residential watershed in Saint Paul, Minnesota during 2012-2014. Our data demonstrate that winter melt events contribute a high percentage of annual N and P export (50%). We hypothesized that overwintering leaf litter that is not removed by fall street sweeping could be an important source to winter loads of N and P. We estimated contributions of this source by studying decomposition in lawns, street gutters, and catch basins during two winters. Rates of mass and N loss were negligible during both winters. However, P was quickly solubilized from decomposing leaves. Using mass balances and estimates of P leaching losses, we estimated that leaf litter could contribute 80% of winter total dissolved phosphorus (TDP) loading in this watershed (∼40% of annual TDP loading). Our work indicates that urban trees adjacent to streets likely represent a major source of P pollution in northern cities. Management that targets important winter sources such as tree leaves could be highly effective for reducing P loading and may mitigate eutrophication in urban lakes and streams in developed cities.

  16. Comparison of mercury mass loading in streams to atmospheric deposition in watersheds of Western North America: Evidence for non-atmospheric mercury sources

    Science.gov (United States)

    Domagalski, Joseph L.; Majewski, Michael S.; Alpers, Charles N.; Eckley, Chris S.; Eagles-Smith, Collin A.; Schenk, Liam N.; Wherry, Susan

    2016-01-01

    Annual stream loads of mercury (Hg) and inputs of wet and dry atmospheric Hg deposition to the landscape were investigated in watersheds of the Western United States and the Canadian-Alaskan Arctic. Mercury concentration and discharge data from flow gauging stations were used to compute annual mass loads with regression models. Measured wet and modeled dry deposition were compared to annual stream loads to compute ratios of Hg stream load to total Hg atmospheric deposition. Watershed land uses or cover included mining, undeveloped, urbanized, and mixed. Of 27 watersheds that were investigated, 15 had some degree of mining, either of Hg or precious metals (gold or silver), where Hg was used in the amalgamation process. Stream loads in excess of annual Hg atmospheric deposition (ratio > 1) were observed in watersheds containing Hg mines and in relatively small and medium-sized watersheds with gold or silver mines, however, larger watersheds containing gold or silver mines, some of which also contain large dams that trap sediment, were sometimes associated with lower load ratios (< 0.2). In the non-Arctic regions, watersheds with natural vegetation tended to have low ratios of stream load to Hg deposition (< 0.1), whereas urbanized areas had higher ratios (0.34–1.0) because of impervious surfaces. This indicated that, in ecosystems with natural vegetation, Hg is retained in the soil and may be transported subsequently to streams as a result of erosion or in association with dissolved organic carbon. Arctic watersheds (Mackenzie and Yukon Rivers) had a relatively elevated ratio of stream load to atmospheric deposition (0.27 and 0.74), possibly because of melting glaciers or permafrost releasing previously stored Hg to the streams. Overall, our research highlights the important role of watershed characteristics in determining whether a landscape is a net source of Hg or a net sink of atmospheric Hg.

  17. Comparison of mercury mass loading in streams to atmospheric deposition in watersheds of Western North America: Evidence for non-atmospheric mercury sources.

    Science.gov (United States)

    Domagalski, Joseph; Majewski, Michael S; Alpers, Charles N; Eckley, Chris S; Eagles-Smith, Collin A; Schenk, Liam; Wherry, Susan

    2016-10-15

    Annual stream loads of mercury (Hg) and inputs of wet and dry atmospheric Hg deposition to the landscape were investigated in watersheds of the Western United States and the Canadian-Alaskan Arctic. Mercury concentration and discharge data from flow gauging stations were used to compute annual mass loads with regression models. Measured wet and modeled dry deposition were compared to annual stream loads to compute ratios of Hg stream load to total Hg atmospheric deposition. Watershed land uses or cover included mining, undeveloped, urbanized, and mixed. Of 27 watersheds that were investigated, 15 had some degree of mining, either of Hg or precious metals (gold or silver), where Hg was used in the amalgamation process. Stream loads in excess of annual Hg atmospheric deposition (ratio>1) were observed in watersheds containing Hg mines and in relatively small and medium-sized watersheds with gold or silver mines, however, larger watersheds containing gold or silver mines, some of which also contain large dams that trap sediment, were sometimes associated with lower load ratios (<0.2). In the non-Arctic regions, watersheds with natural vegetation tended to have low ratios of stream load to Hg deposition (<0.1), whereas urbanized areas had higher ratios (0.34-1.0) because of impervious surfaces. This indicated that, in ecosystems with natural vegetation, Hg is retained in the soil and may be transported subsequently to streams as a result of erosion or in association with dissolved organic carbon. Arctic watersheds (Mackenzie and Yukon Rivers) had a relatively elevated ratio of stream load to atmospheric deposition (0.27 and 0.74), possibly because of melting glaciers or permafrost releasing previously stored Hg to the streams. Overall, our research highlights the important role of watershed characteristics in determining whether a landscape is a net source of Hg or a net sink of atmospheric Hg.

  18. Sediment and Nutrient Contributions from Subsurface Drains and Point Sources to an Agricultural Watershed

    Directory of Open Access Journals (Sweden)

    Bonnie Ball Coelho

    2010-03-01

    Full Text Available Excess sediment and nutrients in surface waters can threaten aquatic life. To determine the relative importance of subsurface drainage as a pathway for movement of sediment and nutrients to surface waters, loading from various tile systems was compared to that from sewage treatment plants (STP within the same watershed. Movement through tiles comprised 1 to 8% of estimated total (overland plus tile annual sediment loading from the respective areas drained by the tile. Load during the growing season from five closed drain- age systems without surface inlets averaged 5 kg sediment/ha, 0.005 kg dissolved reactive P (DRP/ha, 0.003 kg NH4-N/ha, and 3.8 kg NO3-N/ha; and from two open drainage systems with surface inlets averaged 14 kg sediment/ha, 0.03 kg DRP/ha, 0.04 kg NH4-N/ha, and 3.1 kg NO3-N/ha. The eight STP contributed about 44 530 kg suspended sediments, 3380 kg total P, 1340 kg NH4-N, and 116 900 kg NO3-N to the watershed annually. Drainage systems added less NH4-N and P, but more NO3-N and suspended solids to surface waters than STP. Tile drainage pathways for NO3-N, STP in the case of P, and overland pathways for sediment are indicated as targets to control loading in artificially drained agricultural watersheds.

  19. Denitrification in the shallow ground water of a tile-drained, agricultural watershed

    Science.gov (United States)

    Mehnert, E.; Hwang, H.-H.; Johnson, T.M.; Sanford, R.A.; Beaumont, W.C.; Holm, T.R.

    2007-01-01

    Nonpoint-source pollution of surface water by N is considered a major cause of hypoxia. Because Corn Belt watersheds have been identified as major sources of N in the Mississippi River basin, the fate and transport of N from midwestern agricultural watersheds have received considerable interest. The fate and transport of N in the shallow ground water of these watersheds still needs additional research. Our purpose was to estimate denitrification in the shallow ground water of a tile-drained, Corn Belt watershed with fine-grained soils. Over a 3-yr period, N was monitored in the surface and ground water of an agricultural watershed in central Illinois. A significant amount of N was transported past the tile drains and into shallow ground water. The ground water nitrate was isotopically heavier than tile drain nitrate, which can be explained by denitrification in the subsurface. Denitrifying bacteria were found at depths to 10 m throughout the watershed. Laboratory and push-pull tests showed that a significant fraction of nitrate could be denitrified rapidly. We estimated that the N denitrified in shallow ground water was equivalent to 0.3 to 6.4% of the applied N or 9 to 27% of N exported via surface water. These estimates varied by water year and peaked in a year of normal precipitation after 2 yr of below average precipitation. Three years of monitoring data indicate that shallow ground water in watersheds with fine-grained soils may be a significant N sink compared with N exported via surface water. ?? ASA, CSSA, SSSA.

  20. Linking High Frequency Variations in Stream Water DOC to Ages of Water Sources in Peat-Dominated Montane Watersheds

    Science.gov (United States)

    Tunaley, C.; Tetzlaff, D.; Lessels, J. S.; Soulsby, C.

    2015-12-01

    We combined time series of inferred DOC (from optical sensors) and stable isotopes in streams and watershed source areas to assess the link between water age and C fluxes. We monitored temporal dynamics of FDOM for 2 yrs at nested scales (0.9, 3.0 and 30km2) in a montane Scottish watershed. FDOM was strongly correlated (r2 ~ 0.8) with DOC allowing inference of 15 min timeseries. Marked seasonality was observed, with highest DOC concentrations (~25 mg l-1) in summer events and lower concentrations (~5mg l-1) in winter. During events, anticlockwise hysteresis was observed; consistent with expansion of the riparian saturation zone, increasing hydrological connectivity across peat soils and mobilizing DOC. Lag times for peak discharge and DOC were 1-12 hrs depending on event characteristics and antecedent conditions. Isotope time series from precipitation, streams and catchment source waters (overland flow and hillslope drainage) were also generated. These allowed us to model the non-stationary characteristics of their ages. Stream water age ranges from 3 months at high flows when overland flow dominates runoff to 4 yrs under baseflow. Overland flow age was a dominant influence on DOC transport. Highest concentrations occurred in small summer events with relatively young (strategies.

  1. 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.

  2. Stream restoration and sanitary infrastructure alter sources and fluxes of water, carbon, and nutrients in urban watersheds

    Directory of Open Access Journals (Sweden)

    M. J. Pennino

    2015-12-01

    Full Text Available An improved understanding of sources and timing of water and nutrient fluxes associated with urban stream restoration is critical for guiding effective watershed management. We investigated how sources, fluxes, and flowpaths of water, carbon (C, nitrogen (N, and phosphorus (P shift in response to differences in stream restoration and sanitary infrastructure. We compared a restored stream with 3 unrestored streams draining urban development and stormwater management over a 3 year period. We found that there was significantly decreased peak discharge in response to precipitation events following stream restoration. Similarly, we found that the restored stream showed significantly lower monthly peak runoff (9.4 ± 1.0 mm d−1 compared with two urban unrestored streams (ranging from 44.9 ± 4.5 to 55.4 ± 5.8 mm d−1 draining higher impervious surface cover. Peak runoff in the restored stream was more similar to a less developed stream draining extensive stormwater management (13.2 ± 1.9 mm d−1. Interestingly, the restored stream exported most carbon, nitrogen, and phosphorus loads at relatively lower streamflow than the 2 more urban streams, which exported most of their loads at higher and less frequent streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha−1 yr−1, total nitrogen (4.5 ± 0.3 kg ha−1 yr−1, and total phosphorus (161 ± 15 g ha−1 yr−1 were significantly lower in the restored stream compared to both urban unrestored streams (p < 0.05 and similar to the stream draining stormwater management. Although stream restoration appeared to potentially influence hydrology to some degree, nitrate isotope data suggested that 55 ± 1 % of the nitrate in the restored stream was derived from leaky sanitary sewers (during baseflow, similar to the unrestored streams. Longitudinal synoptic surveys of water and nitrate isotopes along all 4 watersheds suggested the importance of urban groundwater contamination from leaky piped

  3. Stream restoration and sanitary infrastructure alter sources and fluxes of water, carbon, and nutrients in urban watersheds

    Science.gov (United States)

    Pennino, M. J.; Kaushal, S. S.; Mayer, P. M.; Utz, R. M.; Cooper, C. A.

    2015-12-01

    An improved understanding of sources and timing of water and nutrient fluxes associated with urban stream restoration is critical for guiding effective watershed management. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in stream restoration and sanitary infrastructure. We compared a restored stream with 3 unrestored streams draining urban development and stormwater management over a 3 year period. We found that there was significantly decreased peak discharge in response to precipitation events following stream restoration. Similarly, we found that the restored stream showed significantly lower monthly peak runoff (9.4 ± 1.0 mm d-1) compared with two urban unrestored streams (ranging from 44.9 ± 4.5 to 55.4 ± 5.8 mm d-1) draining higher impervious surface cover. Peak runoff in the restored stream was more similar to a less developed stream draining extensive stormwater management (13.2 ± 1.9 mm d-1). Interestingly, the restored stream exported most carbon, nitrogen, and phosphorus loads at relatively lower streamflow than the 2 more urban streams, which exported most of their loads at higher and less frequent streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha-1 yr-1), total nitrogen (4.5 ± 0.3 kg ha-1 yr-1), and total phosphorus (161 ± 15 g ha-1 yr-1) were significantly lower in the restored stream compared to both urban unrestored streams (p export. Given that both stream restoration and sanitary pipe repairs both involve extensive channel manipulation, they can be considered simultaneously in management strategies. In addition, ground water can be a major source of nutrient fluxes in urban watersheds, which has been less considered compared with upland sources and storm drains. Goundwater sources, fluxes, and flowpath should also be targeted in efforts to improve stream restoration strategies and prioritize hydrologic "hot spots" along watersheds where

  4. Identifying sediment sources and delivery mechanisms using background level polycyclic aromatic hydrocarbons in the Waiapu River watershed, New Zealand

    Science.gov (United States)

    Thompson, C. E.; Nichols, E. G.; Johnson, G.; Blair, N. E.; Leithold, E. L.; Palmer, A. S.; Baisden, W. T.

    2009-12-01

    The significant contribution of small mountainous river systems to the global fluvial sediment supply motivates investigation into the processes that influence the composition of the organic carbon that they carry. Organic matter preserved in continental margin sediments originates from terrestrial sources, such as kerogen and fresh and aged soil carbon, as well as marine sources. The identification of specific terrestrial fractions buried can facilitate interpretation of the organic geochemical record and enable reconstruction of watershed history. Carbon isotopic analyses have been used to apportion terrestrial carbon fractions preserved in marine environments; however, they have been generally limited to resolving modern C and kerogen. In this study, the use of polycyclic aromatic hydrocarbons (PAHs) to examine sediment production in the Waiapu watershed, New Zealand has been investigated. A suite of 42 alkylated and non-alkylated PAH concentrations establish chemical fingerprints for likely terrestrial sources of organic matter feeding the river and margin. Principal component analysis reveals chemical similarity between source and sink based on the degree of weathering and the relative inputs of petrogenic and pyrogenic PAHs. The primary sources of terrestrial organic matter buried over recent history on the continental shelf are Cretaceous bedrock, raw riverbank soils, and pastoral topsoils. Polytopic vector analysis of marine sediment establishes PAH end-member profiles, allowing sedimentary carbon on the shelf to be apportioned to contributing sources. These end-member model profiles confirm the PCA results, corresponding to PAH fingerprints of potential terrestrial sources including (1) bedrock composed of ancient kerogen, (2) soils from riverbank profiles that are composed of mixtures of ancient, aged, and modern carbon, and (3) topsoils typically composed of modern carbon from plant or fire-derived organic matter. Resolution of these sources suggests

  5. Legacy source of mercury in an urban stream-wetland ecosystem in central North Carolina, USA.

    Science.gov (United States)

    Deonarine, Amrika; Hsu-Kim, Heileen; Zhang, Tong; Cai, Yong; Richardson, Curtis J

    2015-11-01

    In the United States, aquatic mercury contamination originates from point and non-point sources to watersheds. Here, we studied the contribution of mercury in urban runoff derived from historically contaminated soils and the subsequent production of methylmercury in a stream-wetland complex (Durham, North Carolina), the receiving water of this runoff. Our results demonstrated that the mercury originated from the leachate of grass-covered athletic fields. A fraction of mercury in this soil existed as phenylmercury, suggesting that mercurial anti-fungal compounds were historically applied to this soil. Further downstream in the anaerobic sediments of the stream-wetland complex, a fraction (up to 9%) of mercury was converted to methylmercury, the bioaccumulative form of the metal. Importantly, the concentrations of total mercury and methylmercury were reduced to background levels within the stream-wetland complex. Overall, this work provides an example of a legacy source of mercury that should be considered in urban watershed models and watershed management.

  6. National, holistic, watershed-scale approach to understand the sources, transport, and fate of agricultural chemicals

    Science.gov (United States)

    Capel, P.D.; McCarthy, K.A.; Barbash, J.E.

    2008-01-01

    This paper is an introduction to the following series of papers that report on in-depth investigations that have been conducted at five agricultural study areas across the United States in order to gain insights into how environmental processes and agricultural practices interact to determine the transport and fate of agricultural chemicals in the environment. These are the first study areas in an ongoing national study. The study areas were selected, based on the combination of cropping patterns and hydrologic setting, as representative of nationally important agricultural settings to form a basis for extrapolation to unstudied areas. The holistic, watershed-scale study design that involves multiple environmental compartments and that employs both field observations and simulation modeling is presented. This paper introduces the overall study design and presents an overview of the hydrology of the five study areas. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  7. Fecal Coliform and E. coli Concentrations in Effluent-Dominated Streams of the Upper Santa Cruz Watershed

    Directory of Open Access Journals (Sweden)

    Emily C. Sanders

    2013-03-01

    Full Text Available This study assesses the water quality of the Upper Santa Cruz Watershed in southern Arizona in terms of fecal coliform and Escherichia coli (E. coli bacteria concentrations discharged as treated effluent and from nonpoint sources into the Santa Cruz River and surrounding tributaries. The objectives were to (1 assess the water quality in the Upper Santa Cruz Watershed in terms of fecal coliform and E. coli by comparing the available data to the water quality criteria established by Arizona, (2 to provide insights into fecal indicator bacteria (FIB response to the hydrology of the watershed and (3 to identify if point sources or nonpoint sources are the major contributors of FIB in the stream. Assessment of the available wastewater treatment plant treated effluent data and in-stream sampling data indicate that water quality criteria for E. coli and fecal coliform in recreational waters are exceeded at all locations of the Santa Cruz River. For the wastewater discharge, 13%–15% of sample concentrations exceeded the 800 colony forming units (cfu per 100 mL sample maximum for fecal coliform and 29% of samples exceeded the full body contact standard of 235 cfu/100 mL established for E. coli; while for the in-stream grab samples, 16%–34% of sample concentrations exceeded the 800 cfu/100 mL sample maximum for fecal coliforms and 34%–75% of samples exceeded the full body contact standard of 235 cfu/100 mL established for E. coli. Elevated fecal coliform and E. coli concentrations were positively correlated with periods of increased streamflow from rainfall. FIB concentrations observed in-stream are significantly greater (p-value < 0.0002 than wastewater treatment plants effluent concentrations; therefore, water quality managers should focus on nonpoint sources to reduce overall fecal indicator loads. Findings indicate that fecal coliform and E. coli concentrations are highly variable, especially along urban streams and generally increase with

  8. 基于改进USLE模型的北运河流域非点源污染潜在敏感区分析%Potential Sensitive Areas Analysis of Non-Point Source Pollution in North Canal Basin based on Improved USLE Model

    Institute of Scientific and Technical Information of China (English)

    靳美珠; 张晓惠; 袁雪竹

    2012-01-01

    Based on the universal soil loss equation (USLE), the model of demarcation of sensitive areas of the non-point pollution in North Canal basin is developed. With the database of TM remote sensing images, digital elevation model (DEM), and the map of soil use type in research area in 2009, distribution map of sensitive areas of non-point source in North Canal basin is produced by the model. Base on the simulation, the three risk areas (high, medium and low) and safe areas are identified. Results show that improved model can be effectively used in the analysis of sensitive areas of non-point source pollution.%基于通用土壤流失方程(USLE)建立北运河流域非点源污染敏感区的划分模型,以2009年研究区域TM遥感影像、数字高程模型(DEM)、研究区土壤利用类型图等为数据基础,在GIS9.3和ERDAS9.2平台上通过对各模型因子进行栅格运算生成北运河流域非点源污染潜在敏感区分布图,在此基础上划分了高、中、低三个风险区以及安全区.鉴于我国与美国不同的自然条件,以及土壤流失与固体垃圾的扩散之间所存在的差异,在引进和应用该模型时,对方程中各因子的算法和参数做了一定的调整和改进,结果表明改进后的模型可以有效的运用于非点源污染敏感区的分析.

  9. Sources of dissolved and particulate organic material in Loch Vale Watershed, Rocky Mountain National Park, Colorado, USA

    Science.gov (United States)

    Baron, J.; McKnight, D.; Denning, A.S.

    1991-01-01

    The sources of both dissolved organic carbon (DOC) and particulate organic carbon (POC) to an alpine (Sky Pond) and a subalpine lake (The Loch) in Rocky Mountain National Park were explored for four years. The importance of both autochthonous and allochthonous sources of organic matter differ, not only between alpine and subalpine locations, but also seasonally. Overall, autochthonous sources dominate the organic carbon of the alpine lake, while allochthonous sources are a more significant source of organic carbon to the subalpine lake. In the alpine lake, Sky Pond, POC makes up greater than one third of the total organic matter content of the water column, and is related to phytoplankton abundance. Dissolved organic carbon is a product of within-lake activity in Sky Pond except during spring snowmelt and early summer (May-July), when stable carbon isotope ratios suggest a terrestrial source. In the subalpine lake, The Loch, DOC is a much more important constituent of water column organic material than POC, comprising greater than 90% of the spring snowmelt organic matter, and greater than 75% of the organic matter over the rest of the year. Stable carbon isotope ratios and a very strong relation of DOC with soluble Al(tot) indicate DOC concentrations are almost entirely related to flushing of soil water from the surrounding watershed during spring snowmelt. Stable carbon isotope ratios indicate that, for both lakes, phytoplankton is an important source of DOC in the winter, while terrestrial material of plant or microbial origin contributes DOC during snowmelt and summer. ?? 1991 Kluwer Academic Publishers.

  10. Spatial-temporal Variation of Agricultural Non-point Source Pollution Based on GIS Technology in Guangdong Province, China%基于GIS的广东省农业面源污染的时空分异研究

    Institute of Scientific and Technical Information of China (English)

    叶延琼; 章家恩; 李逸勉; 李韵; 吴睿珊

    2013-01-01

    近年来,广东省化肥、农药等农用化学品的投入量大增,农业面源污染问题日趋严重.采用历年统计数据以及GIS技术,对广东省农业面源污染的时空分异性进行了分析.结果表明,全省化肥、农药使用量均呈逐年增加态势,化肥使用量由1990年的162.41万t增加到2010年的237.29万t,农药由1990年的7.95万t增加到2010年的10.44万t.畜禽粪尿排放量则由2000年的339.34亿t减少到2010年的222.08亿t;在空间分布上,全省化肥投入强度超过400 kg· hm-2的县(市)由1995年的35个增加到2010年的61个,粤西、粤东全部,珠三角大部以及粤北部分地区均属化肥严重污染区,其原因主要在于对农作物产量增加的追求.农药投入强度超过30 kg· hm-2的县(市)由1995年的10个增加到2010年的27个,这主要是由于广东的气候条件及种植结构改变造成的.畜禽粪尿排放污染情况相对较好,但因粤西的雷州半岛地区以水稻生产为主,大牲畜牛的养殖规模较大,因此畜禽粪尿重度污染主要集中在这一地区.GIS空间分析的运用,能直观地反映各地区农业面源污染的时空动态变化情况,为有针对性地开展污染治理提供依据.%Agriculture non-point source pollution (ANSP) is becoming a serious environmental concern in Guangdong Province due to the increased applications of agricultural chemicals such as fertilizers and pesticides in recent years. This study investigated the spatial-temporal variation of ANSP using the historical statistical data and GIS technology. Results showed that the fertilizer, pesticide and other agrochemical applications in Guangdong Province were increased and reached quite a high level in order to secure food supply. The total amount of chemical fertilizer application increased from 1.62x1061 in 1990 to 2.73x1061 in 2010 and the total amount of pesticide application elevated from 7.95X1041 to 10.04X1041, while the total amount of animal manure

  11. A VSA-based strategy for placing conservation buffers in agricultural watersheds.

    Science.gov (United States)

    Qiu, Zeyuan

    2003-09-01

    Conservation buffers have the potential to reduce agricultural nonpoint source pollution and improve terrestrial wildlife habitat, landscape biodiversity, flood control, recreation, and aesthetics. Conservation buffers, streamside areas and riparian wetlands are being used or have been proposed to control agricultural nonpoint source pollution. This paper proposes an innovative strategy for placing conservation buffers based on the able source area (VSA) hydrology. VSAs are small, variable but predictable portion of a watershed that regularly contributes to runoff generation. The VSA-based strategy involves the following three steps: first, identifying VSAs in landscapes based on natural characteristics such as hydrology, land use/cover, topography and soils; second, targeting areas within VSAs for conservation buffers; third, refining the size and location of conservation buffers based on other factors such as weather, environmental objectives, available funding and other best management practices. Building conservation buffers in VSAs allows agricultural runoff to more uniformly enter buffers and stay there longer, which increases the buffer's capacity to remove sediments and nutrients. A field-scale example is presented to demonstrate the effectiveness and cost-effectiveness of the within-VSA conservation buffer scenario relative to a typical edge-of-field buffer scenario. The results enhance the understanding of hydrological processes and interactions between agricultural lands and conservation buffers in agricultural landscapes, and provide practical guidance for land resource managers and conservationists who use conservation buffers to improve water quality and amenity values of agricultural landscape.

  12. Comparison of Mercury Mass Loading in Streams to Wet and Dry Atmospheric Deposition in Watersheds of the Western US: Evidence for Non-Atmospheric Mercury Sources

    Science.gov (United States)

    Domagalski, J. L.; Majewski, M. S.; Alpers, C. N.; Eckley, C.

    2015-12-01

    Many streams in the western United States (US) are listed as impaired by mercury (Hg), and it is important to understand the magnitudes of the various sources in order to implement management strategies. Atmospheric deposition of Hg and can be a major source of aquatic contamination, along with mine wastes, and other sources. Prior studies in the eastern US have shown that streams deliver less than 50% of the atmospherically deposited Hg on an annual basis. In this study, we compared annual stream Hg loads for 20 watersheds in the western US to measured wet and modeled dry deposition. Land use varies from undisturbed to mixed (agricultural, urban, forested, mining). Data from the Mercury Deposition Network was used to estimate Hg input from precipitation. Dry deposition was not directly measured, but can be modeled using the Community Multi-scale Air Quality model. At an undeveloped watershed in the Rocky Mountains, the ratio of stream Hg load to atmospheric deposition was 0.2 during a year of average precipitation. In contrast, at the Carson River in Nevada, with known Hg contamination from historical silver mining with Hg amalgamation, stream export exceeded atmospheric deposition by a factor of 60, and at a small Sierran watershed with gold mining, the ratio was 70. Larger watersheds with mixed land uses, tend to have lower ratios of stream export relative to atmospheric deposition suggesting storage of Hg. The Sacramento River was the largest watershed for which Hg riverine loads were available with an average ratio of stream Hg export to atmospheric deposition of 0.10. Although Hg was used in upstream historical mining operations, the downstream river Hg load is partially mitigated by reservoirs, which trap sediment. This study represents the first compilation of riverine Hg loads in comparison to atmospheric deposition on a regional scale; the approach may be useful in assessing the relative importance of atmospheric and non-atmospheric Hg sources.

  13. Using Predictive Uncertainty Analysis to Assess Hydrologic Model Performance for a Watershed in Oregon

    Science.gov (United States)

    Brannan, K. M.; Somor, A.

    2016-12-01

    A variety of statistics are used to assess watershed model performance but these statistics do not directly answer the question: what is the uncertainty of my prediction. Understanding predictive uncertainty is important when using a watershed model to develop a Total Maximum Daily Load (TMDL). TMDLs are a key component of the US Clean Water Act and specify the amount of a pollutant that can enter a waterbody when the waterbody meets water quality criteria. TMDL developers use watershed models to estimate pollutant loads from nonpoint sources of pollution. We are developing a TMDL for bacteria impairments in a watershed in the Coastal Range of Oregon. We setup an HSPF model of the watershed and used the calibration software PEST to estimate HSPF hydrologic parameters and then perform predictive uncertainty analysis of stream flow. We used Monte-Carlo simulation to run the model with 1,000 different parameter sets and assess predictive uncertainty. In order to reduce the chance of specious parameter sets, we accounted for the relationships among parameter values by using mathematically-based regularization techniques and an estimate of the parameter covariance when generating random parameter sets. We used a novel approach to select flow data for predictive uncertainty analysis. We set aside flow data that occurred on days that bacteria samples were collected. We did not use these flows in the estimation of the model parameters. We calculated a percent uncertainty for each flow observation based 1,000 model runs. We also used several methods to visualize results with an emphasis on making the data accessible to both technical and general audiences. We will use the predictive uncertainty estimates in the next phase of our work, simulating bacteria fate and transport in the watershed.

  14. FECAL SOURCE TRACKING BY ANTIBIOTIC RESISTANCE ANALYSIS ON A WATERSHED EXHIBITING LOW RESISTANCE

    Science.gov (United States)

    The ongoing development of microbial source tracking has made it possible to identify contamination sources with varying accuracy, depending on the method used. The purpose of this study was done to test the efficiency of the antibiotic resistance analysis (ARA) method under low ...

  15. FECAL SOURCE TRACKING BY ANTIBIOTIC RESISTANCE ANALYSIS ON A WATERSHED EXHIBITING LOW RESISTANCE

    Science.gov (United States)

    The ongoing development of microbial source tracking has made it possible to identify contamination sources with varying accuracy, depending on the method used. The purpose of this study was done to test the efficiency of the antibiotic resistance analysis (ARA) method under low ...

  16. [Risk assessment of nitrogen and phosphorus export in upper reach of Daliao river watershed].

    Science.gov (United States)

    Liu, Rui-Min; He, Meng-Chang; Wang, Xiu-Juan

    2009-03-15

    With the development of point pollution control, non-point source pollution has become an important environmental and water quality management problem. Land cover composition across a watershed is a dominant factor in controlling the amount of nitrogen and phosphorus exported from a watershed. Generally, urban and agricultural land covers are considered as principal sources of excess loads of nitrogen (N) and phosphorous (P) in receiving waters. A well developed literature of nutrient export coefficients by land-cover class was used to model the risk of equaling or exceeding specified levels of nutrient export in drainage basin of Dahuofang Reservoir. The model was applied to about 513 comparatively small watersheds mapped for the drainage basin of Dahuofang Reservoir for environmental analysis and planning. The results suggest that the probabilities of risk are 19.31% and 8.95% for N and P nutrient respectively. As the spatial distribution concerned, risk estimates generally differed with different slope degrees and districts. Risk estimates generally increased from the places where lies near the rivers to the places where are far from the river, but numerous areas of high variability were evident.

  17. BMP analysis system for watershed-based stormwater management.

    Science.gov (United States)

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

    2006-01-01

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

  18. 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.

  19. Soil and Water Assessment Tool (SWAT) Applicability on Nutrients Loadings Prediction in Mountainous Lower Bear Malad River (LBMR) Watershed, Utah.

    Science.gov (United States)

    Salha, A. A.; Stevens, D. K.

    2014-12-01

    The application of watershed simulation models is indispensable when pollution is generated by a nonpoint source. These models should be able to simulate large complex watersheds with varying soils, land use and management conditions over long periods of time. This study presents the application of Soil and Water Assessment Tool (SWAT) to investigate, manage, and research the transport and fate of nutrients in (Subbasin HUC 16010204) Lower Bear Malad River (LBMR) watershed, Box elder County, Utah. Water quality problems arise primarily from high phosphorus and total suspended sediment concentrations that were caused by increasing agricultural and farming activities and complex network of canals and ducts of varying sizes and carrying capacities that transport water (for farming and agriculture uses). Using the available input data (Digital Elevation Model (DEM), land use/Land cover (LULC), soil map and weather and climate data for 20 years (1990-2010) to predict the water quantity and quality of the LBMR watershed using a spatially distributed model version of hydrological ArcSWAT model (ArcSWAT 2012.10_1.14). No previous studies have been found in the literature regarding an in-depth simulation study of the Lower Bear Malad River (LBMR) watershed to simulate stream flow and to quantify the associated movement of nitrogen, phosphorus, and sediment. It is expected that the model mainly will predict monthly mean total phosphorus (TP) concentration and loadings in a mountainous LBRM watershed (steep Wellsville mountain range with peak of (2,857 m)) having into consideration the snow and runoff variables affecting the prediction process. The simulated nutrient concentrations were properly consistent with observations based on the R2 and Nash- Sutcliffe fitness factors. Further, the model will be able to manage and assess the land application in that area with corresponding to proper BMPs regarding water quality management. Keywords: Water Quality Modeling; Soil and

  20. A decision support system for phosphorus management at a watershed scale.

    Science.gov (United States)

    Djodjic, Faruk; Montas, Hubert; Shirmohammadi, Adel; Bergström, Lars; Ulén, Barbro

    2002-01-01

    Phosphorus (P) is one of the main nutrients controlling algal production in aquatic systems. Proper management of P in agricultural production systems can greatly enhance our ability to combat pollution of aquatic environments. To address this issue, a decision support system (DSS) consisting of the Maryland Phosphorus Index (PI), diagnosis expert system (ES), prescription ES, and a nonpoint-source pollution model, Ground Water Loading Effects of Agricultural Management Systems (GLEAMS), was developed and applied to an agricultural watershed in southern Sweden. This system can identify critical source areas (CSAs) regarding phosphorus losses within the watershed, make a diagnosis of probable causes, prescribe the most appropriate best management practices (BMPs), and test the environmental effects of the applied BMPs. The PI calculations identified small parts of the watershed as CSAs. Only 10.4% of the total watershed area in 1995 and 5.2% of the total watershed area in 1996 were classed as "high potential P movement." Four probable causes (high P level in soil, excessive P fertilization, stream proximity, and subsurface drainage) and three BMPs (riparian buffer strips, reduced P fertilizer application, and P fertilizer incorporation) were identified by a diagnosis and prescription expert system. The GLEAMS simulations conducted for one selected CSA field for a 24-yr period showed that the recommended BMP reduced runoff P losses by 55% and sediment P losses by 71%, if applied from the first year. Results showed that using DSS may enable us to select a proper BMP implementation strategy and to realize the beneficial effect of BMPs on a long-term basis.

  1. Integrated Watershed Pollution Control at Wujingang Canal, China

    Science.gov (United States)

    Zheng, Z.; Yang, X.; Luo, X.

    2012-04-01

    With a drainage area of 400 square kilometers, Wujingang Canal is located at the economically developed Yangtz Delta of eastern China. As a major tributary, the canal contributes a significant amount of pollutant load to the Lake Tai. Over the past many years, water quality of the canal and its tributaries could not meet the lowest Category V of Chinese surface water quality standard, indicating that its water is not suitable for the purposes of irrigation or scenic views. Major pollution sources in the watershed include industries, residential households, agriculture, fishery, and animal feedlot operations. A comprehensive plan with a budget of 2 billion RMB for the Wujingang watershed pollution control was developed in 2008 and has been implemented progressively ever since. Major components of the plan include: (1) advanced treatment of wastewater from industries and municipal sewage plants for further removal of nitrogen and phosphorous; (2) industrial wastewater reuse; (3) contiguous treatment of sewage from rural residential households with cost-effective technologies such as tower ecofilter system; (4) recycling of rural wastes to generate high-value added products using technologies such as multi-phase anaerobic co-digestion; and (5) making full use of the local landscape and configuring physical, chemical, and biological pollutant treatment structures to build the "clean river network" for treatment of mildly polluted agricultural discharge and surface runoff. Through the implementation of the above measures, water quality of the Wujingang Canal and its tributaries is expected to improve to meet Category IV of Chinese surface water quality standard by 2012, and Category III standard by 2020. Keywords watershed pollution control, non-point source pollution, rural sewage, rural waste, Lake Tai

  2. REMOTE SENSING APPLICATIONS FOR SUSTAINABLE WATERSHED MANAGEMENT AND FOOD SECURITY

    Science.gov (United States)

    The integration of IKONOS satellite data, airborne color infrared remote sensing, visualization, and decision support tools is discussed, within the contexts of management techniques for minimizing non-point source pollution in inland waterways, such s riparian buffer restoration...

  3. REMOTE SENSING APPLICATIONS FOR SUSTAINABLE WATERSHED MANAGEMENT AND FOOD SECURITY

    Science.gov (United States)

    The integration of IKONOS satellite data, airborne color infrared remote sensing, visualization, and decision support tools is discussed, within the contexts of management techniques for minimizing non-point source pollution in inland waterways, such s riparian buffer restoration...

  4. Tracing the Nitrate Sources of the Yili River in the Taihu Lake Watershed: A Dual Isotope Approach

    Directory of Open Access Journals (Sweden)

    Haiao Zeng

    2014-12-01

    Full Text Available As the third largest freshwater lake in China, Taihu Lake has experienced severe cyanobacterial blooms and associated water quality degradation in recent decades, threatening the human health and sustainable development of cities in the watershed. The Yili River is a main river of Taihu Lake, contributing about 30% of the total nitrogen load entering the lake. Tracing the nitrate sources of Yili River can inform the origin of eutrophication in Taihu Lake and provide hints for effective control measures. This paper explored the nitrate sources and cycling of the Yili River based on dual nitrogen (δ15N and oxygen (δ18O isotopic compositions. Water samples collected during both the wet and dry seasons from different parts of the Yili River permitted the analysis of the seasonal and spatial variations of nitrate concentrations and sources. Results indicated that the wet season has higher nitrate concentrations than the dry season despite the stronger dilution effects, suggesting a greater potential of cyanobacterial blooms in summer. The δ15N-NO3− values were in the range of 4.0‰–14.0‰ in the wet season and 4.8‰–16.9‰ in dry, while the equivalent values of δ18O were 0.5‰–17.8‰ and 3.5‰–15.6‰, respectively. The distribution of δ15N-NO3− and δ18O-NO3− indicated that sewage and manure as well as fertilizer and soil organic matter were the major nitrate sources of the Yili River. Atmospheric deposition was an important nitrate source in the upper part of Yili River but less so in the middle and lower reaches due to increasing anthropogenic contamination. Moreover, there was a positive relationship between δ18O-NO3− and δ15N-NO3− in the wet season, indicating a certain extent of denitrification. In contrast, the δ18O-δ15N relationship in the dry season was significantly negative, suggesting that the δ15N and δ18O values were determined by a mixing of different nitrate sources.

  5. Multi-year microbial source tracking study characterizing fecal contamination in an urban watershed

    Science.gov (United States)

    Bushon, Rebecca N.; Brady, Amie M G.; Christensen, Eric D.; Stelzer, Erin A.

    2017-01-01

    Microbiological and hydrological data were used to rank tributary stream contributions of bacteria to the Little Blue River in Independence, Missouri. Concentrations, loadings and yields of E. coli and microbial source tracking (MST) markers, were characterized during base flow and storm events in five subbasins within Independence, as well as sources entering and leaving the city through the river. The E. coli water quality threshold was exceeded in 29% of base-flow and 89% of storm-event samples. The total contribution of E. coli and MST markers from tributaries within Independence to the Little Blue River, regardless of streamflow, did not significantly increase the median concentrations leaving the city. Daily loads and yields of E. coli and MST markers were used to rank the subbasins according to their contribution of each constituent to the river. The ranking methodology used in this study may prove useful in prioritizing remediation in the different subbasins.

  6. Historical data review and source analysis of PCBs/Arochlors in the Lower Leon Creek Watershed.

    Science.gov (United States)

    Shipley, Heather J; Sokoly, Diana; Johnson, Drew W

    2017-02-01

    PCBs have been banned since the late 1970s, but concentrations still exist in sediments and riverine fish and continue to exceed regulatory limits which can result in negative health effects. This study looks at historical records of PCB and Arochlor concentrations in surface water, sediments, and fish tissue for the Lower Leon Creek, Bexar County in Texas. Temporal analysis on the concentrations of PCBs and Arochlors was conducted for detection and exceedance of selected screening criteria. In addition, the half-lives of select PCB congeners were calculated for 2007-2012 data to ascertain differences in PCB concentrations with their hydrophobicity. Source analysis was conducted to determine the potential contributing sources of PCB contamination using source data (landfills, outfalls, etc.) and the PCB exceedance data. For sediment and fish tissue sampling results, historic data shows high concentrations of PCB/Arochlors over the course of several decades. The historical data is characterized as being widely variable for detections in Arochlors and concentrations between years, with a dramatic drop in concentrations detected starting in 2009. Overall, the sampling locations adjacent to and downstream from the former Kelly Air Force Base have the highest concentrations of PCB/Arochlors over the longest period of time. The results of this work will aid regulatory agencies in addressing impairment.

  7. From deposition to erosion: spatial and temporal variability of sediment sources, storage, and transport in a small agricultural watershed

    Science.gov (United States)

    Florsheim, J.L.; Pellerin, B.A.; Oh, N.H.; Ohara, N.; Bachand, P.A.M.; Bachand, Sandra M.; Bergamaschi, B.A.; Hernes, P.J.; Kavvas, M.L.

    2011-01-01

    The spatial and temporal variability of sediment sources, storage, and transport were investigated in a small agricultural watershed draining the Coast Ranges and Sacramento Valley in central California. Results of field, laboratory, and historical data analysis in the Willow Slough fluvial system document changes that transformed a transport-limited depositional system to an effective erosion and transport system, despite a large sediment supply. These changes were caused by a combination of factors: (i) an increase in transport capacity, and (ii) hydrologic alteration. Alteration of the riparian zone and drainage network pattern during the past ~ 150 years included a twofold increase in straightened channel segments along with a baselevel change from excavation that increased slope, and increased sediment transport capacity by ~ 7%. Hydrologic alteration from irrigation water contributions also increased transport capacity, by extending the period with potential for sediment transport and erosion by ~ 6 months/year. Field measurements document Quaternary Alluvium as a modern source of fine sediment with grain size distributions characterized by 5 to 40% fine material. About 60% of an upland and 30% of a lowland study reach incised into this deposit exhibit bank erosion. During this study, the wet 2006 and relatively dry 2007 water years exhibited a range of total annual suspended sediment load spanning two orders of magnitude: ~ 108,500 kg/km2/year during 2006 and 5,950 kg/km2/year during 2007, only 5% of that during the previous year. Regional implications of this work are illustrated by the potential for a small tributary such as Willow Slough to contribute sediment – whereas large dams limit sediment supply from larger tributaries – to the Sacramento River and San Francisco Bay Delta and Estuary. This work is relevant to lowland agricultural river–floodplain systems globally in efforts to restore aquatic and riparian functions and where water quality

  8. Potential pollutant sources in a Choptank River (USA) subwatershed and the influence of land use and watershed characteristics

    Science.gov (United States)

    Nino de Guzman, Gabriela T.; Hapeman, Cathleen J.; Prabhakara, Kusuma; Codling, Eton E.; Shelton, Daniel R.; Rice, Clifford P.; Hively, W. Dean; McCarty, Gregory W.; Lang, Megan W.; Torrents, Alba

    2012-01-01

    Row-crop and poultry production have been implicated as sources of water pollution along the Choptank River, an estuary and tributary of the Chesapeake Bay. This study examined the effects of land use, subwatershed characteristics, and climatic conditions on the water quality parameters of a subwatershed in the Choptank River watershed. The catchments within the subwatershed were defined using advanced remotely-sensed data and current geographic information system processing techniques. Water and sediment samples were collected in May–October 2009 and April–June 2010 under mostly baseflow conditions and analyzed for select bacteria, nitrate-N, ammonium-N, total arsenic, total phosphorus (TP), orthophosphate (ortho-P), and particle-phase phosphorus (PP); n = 96 for all analytes except for arsenic, n = 136, and for bacteria, n = 89 (aqueous) and 62 (sediment). Detections of Enterococci and Escherichia coli concentrations were ubiquitous in this subwatershed and showed no correlation to location or land use, however larger bacterial counts were observed shortly after precipitation. Nitrate-N concentrations were not correlated with agricultural lands, which may reflect the small change in percent agriculture and/or the similarity of agronomic practices and crops produced between catchments. Concentration data suggested that ammonia emission and possible deposition to surface waters occurred and that these processes may be influenced by local agronomic practices and climatic conditions. The negative correlation of PP and arsenic concentrations with percent forest was explained by the stronger signal of the head waters and overland flow of particulate phase analytes versus dissolved phase inputs from groundwater. Service roadways at some poultry production facilities were found to redirect runoff from the facilities to neighboring catchment areas, which affected water quality parameters. Results suggest that in this subwatershed, catchments with poultry production

  9. Assessment of fecal pollution sources in a small northern-plains watershed using PCR and phylogenetic analyses of Bacteroidetes 16S rRNA gene

    Science.gov (United States)

    Lamendella, R.; Domingo, J.W.S.; Oerther, D.B.; Vogel, J.R.; Stoeckel, D.M.

    2007-01-01

    We evaluated the efficacy, sensitivity, host-specificity, and spatial/temporal dynamics of human- and ruminant-specific 16S rRNA gene Bacteroidetes markers used to assess the sources of fecal pollution in a fecally impacted watershed. Phylogenetic analyses of 1271 fecal and environmental 16S rRNA gene clones were also performed to study the diversity of Bacteroidetes in this watershed. The host-specific assays indicated that ruminant feces were present in 28-54% of the water samples and in all sampling seasons, with increasing frequency in downstream sites. The human-targeted assays indicated that only 3-5% of the water samples were positive for human fecal signals, although a higher percentage of human-associated signals (19-24%) were detected in sediment samples. Phylogenetic analysis indicated that 57% of all water clones clustered with yet-to-be-cultured Bacteroidetes species associated with sequences obtained from ruminant feces, further supporting the prevalence of ruminant contamination in this watershed. However, since several clusters contained sequences from multiple sources, future studies need to consider the potential cosmopolitan nature of these bacterial populations when assessing fecal pollution sources using Bacteroidetes markers. Moreover, additional data is needed in order to understand the distribution of Bacteroidetes host-specific markers and their relationship to water quality regulatory standards. ?? 2006 Federation of European Microbiological Societies.

  10. 农业面源污染治理的政策效用评估以江苏省海安县的测土配方施肥推广为例%Agricultural Non-point Source Pollution Controlling Policy's Utility Evaluation Based on Environmental Cost:A Case Study of Soil Testing and Fertilizer Recommendation Technology in Hai'an County

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    为衡量农业面源污染治理政策的作用效果,文章基于环境成本的视角,探索了农业面源污染治理政策效用评估的一般方法与步骤。首先,结合农业化肥的环境污染特点,利用输出系数模型以实现对区域内农业化肥造成的总氮TN、总磷TP排放量的合理测算。然后,建立了基于能值分析法的环境成本估计模型,并结合经济成本和经济收益,构建了基于成本-收益分析的农业面源污染治理政策效用评估的一般模型。最后,以江苏省海安县的测土配方施肥技术的推广为例,对海安县测土配方施肥节本增收效果进行综合评价,并探索了江苏省实现测土配方施肥全覆盖时的总体效果,为面源污染治理政策的评估提供思路。%In order to assess the policy effect of controlling agricultural non-point source pollution ,this paper ,based on the perspec‐tive of environmental cost ,explores the general methods and steps for utility evaluation of agricultural non-point source pollution's treatment measures .First of all ,combined with the characteristics of environmental pollution caused by agricultural fertilizer ,this paper chooses a rational export coefficient model to calculate total nitrogen (TN) ,total phosphorus (TP) emissions caused by agri‐cultural fertilizer in the region .Then ,targeted at soil testing and fertilizer recommendation technology ,this paper constructs envi‐ronmental cost estimation model based on energy analysis and general utility evaluation model based on cost-benefit analysis .Finally , this paper takes Hai'an County's promotion of soil testing and fertilizer recommendation in Jiangsu Province for example ,the synthe‐sized evaluation of the technology is achieved in saving costs and increasing income .Further ,this paper explores the beneficial se‐quence when the technology is spread to the whole Jiangsu Province ,which will provide ways to better choose

  11. 2011 NATA - Emissions Sources

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes all emissions sources that were modeled in the 2011 National Air Toxics Assessment (NATA), inlcluding point, nonpoint, and mobile sources, and...

  12. Effectiveness of alternative management scenarios on the sediment load in a Mediterranean agricultural watershed

    Directory of Open Access Journals (Sweden)

    Ossama M. M. Abdelwahab

    2014-11-01

    Full Text Available The Annualised Agricultural Non-point Source model was used to evaluate the effectiveness of different management practices to control the soil erosion and sediment load in the Carapelle watershed, a Mediterranean medium-size watershed (506 km2 located in Apulia, Southern Italy. The model was previously calibrated and validated using five years of runoff and sediment load data measured at a monitoring station located at Ordona - Ponte dei Sauri Bridge. A total of 36 events were used to estimate the performance of the model during the period 2007-2011. The model performed well in predicting runoff, as the high values of the coefficients of efficiency and determination during the validation process showed. The peak flows predictions were satisfactory especially for the high flow events; the prediction capability of sediment load was good, even if a slight over-estimation was observed. Simulations of alternative management practices show that converting the most eroding cropland cells (13.5% of the catchment area to no tillage would reduce soil erosion by 30%, while converting them to grass or forest would reduce soil erosion by 36.5% in both cases. A crop rotation of wheat and a forage crop can also provide an effective way for soil erosion control as it reduces erosion by 69%. Those results can provide a good comparative analysis for conservation planners to choose the best scenarios to be adopted in the watershed to achieve goals in terms of soil conservation and water quality.

  13. Mineral sources and transport pathways for arsenic release in a coastal watershed, USA

    Science.gov (United States)

    Foley, Nora K.; Ayuso, Robert A.

    2008-01-01

    Metasedimentary bedrock of coastal Maine contains a diverse suite of As-bearing minerals that act as significant sources of elements found in ground and surface waters in the region. Arsenic sources in the Penobscot Formation include, in order of decreasing As content by weight: löllingite and realgar (c.70%), arsenopyrite, cobaltite, glaucodot, and gersdorffite (in the range of 34–45%), arsenian pyrite ( glaucodot, arsenopyrite-cobaltian > arsenopyrite, cobaltite, gersdorffite, fine-grained pyrite, Ni-pyrite > coarse-grained pyrite. Reactions illustrate that oxidation of Fe-As disulphide group and As-sulphide minerals is the primary release process for As. Liberation of As by carbonation of realgar and orpiment in contact with high-pH groundwaters may contribute locally to elevated contents of As in groundwater, especially where As is decoupled from Fe. Released metals are sequestered in secondary minerals by sorption or by incorporation in crystal structures. Secondary minerals acting as intermediate As reservoirs include claudetite (c.75%), orpiment (61%), scorodite (c. 45%), secondary arsenopyrite (c. 46%), goethite (<4490 ppm), natrojarosite (<42 ppm), rosenite, melanterite, ferrihydrite, and Mn-hydroxide coatings. Some soils also contain Fe-Co-Ni-arsenate, Ca-arsenate, and carbonate minerals. Reductive dissolution of Fe-oxide minerals may govern the ultimate release of iron and arsenic – especially As(V) – to groundwater; however, dissolution of claudetite (arsenic trioxide) may directly contribute As(III). Processes thought to explain the release of As from minerals in bedrock include oxidation of arsenian pyrite or arsenopyrite, or carbonation of As-sulphides, and most models based on these generally rely on discrete minerals or on a fairly limited series of minerals. In contrast, in the Penobscot Formation and other metasedimentary rocks of coastal Maine, oxidation of As-bearing Fe-cobalt-nickel-sulphide minerals, dissolution (by reduction) of

  14. Food Sources and Accessibility and Waste Disposal Patterns across an Urban Tropical Watershed: Implications for the Flow of Materials and Energy

    Directory of Open Access Journals (Sweden)

    Diana C. Garcia-Montiel

    2014-03-01

    Full Text Available Appraising the social-ecological processes influencing the inflow, transformation, and storage of materials and energy in urban ecosystems requires scientific attention. This appraisal can provide an important tool for assessing the sustainability of cities. Socioeconomic activities are mostly responsible for these fluxes, which are well manifested in the household unit. Human behavior associated with cultural traditions, belief systems, knowledge, and lifestyles are important drivers controlling the transfer of materials throughout the urban environment. Within this context, we explored three aspects of household consumption and waste disposal activities along the Río Piedras Watershed in the San Juan metropolitan area of Puerto Rico. These included: the source of food consumed by residents, recycling activities, and trends in connection to the municipality's sewerage system. We randomly interviewed 440 households at 6 sites along the watershed. We also conducted analysis to estimate accessibility to commercial food services for residents in the study areas. Our surveys revealed that nearly all interviewed households (~97% consumed products from supermarkets. In neighborhoods of the upper portion of the watershed, where residential density is low with large areas of vegetative cover, more than 60% of residents consumed food items cultivated in their yards. Less than 36% of residents in the in densely urbanized parts of the lower portion of the watershed consumed items from their yards. Accessibility to commercial stores for food consumption contrasted among study sites. Recycling activities were mostly carried out by residents in the lower portion of the watershed, with better access to recycling programs provided by the municipality. The surveys also revealed that only 4 to 17% of residences in the upper watershed are connected to the sewerage system whereas the large majority uses septic tanks for septic water disposal. For these residents

  15. 东江源山地果畜结合区面源污染生态化控制模式与效果分析%Study on ecological control mode of non-point source pollution from the system of orchard linked with animal husbandry in the valley of Dongjiang River Headwater

    Institute of Scientific and Technical Information of China (English)

    席运官; 刘明庆; 王磊; 汪贞; 李德波; 王宏燕

    2013-01-01

    The paper studied the structure and functions of pig-biogas-fruit-fish eco-agricultural mode in the headwater of Dongjiang River based on the Xinglin farm in Dingnan County, analyzed the controlling effect in quality and quantity to the water pollution nutrition through source controlling, drainage reducing and cleaning, and tested the draining water of Xinglin farm showing that draining water quality was better than the Ⅳ level standard of surface water. It proved that this model had the features of opearational, extentional and low input, and could be the important mode for controlling the non-point source pollution in the headwater of Dongjiang River.%  分析东江源山地果畜结合区“猪-沼-果-鱼”生态农业模式的结构与功能,定性和定量分析农庄采用生态化技术对水体污染物控源、减排、净化的效果,跟踪采样分析农庄排水水质,结果表明,农庄排水全年优于地表水Ⅳ类水标准,该模式兼具可操作、可推广、低投入特性,是东江源控制农业面源污染的重要模式。

  16. Identifying sources of stream water sulfate after a summer drought in the Sleepers River watershed (Vermont, USA) using hydrological, chemical, and isotopic techniques

    Science.gov (United States)

    Mayer, B.; Shanley, J.B.; Bailey, S.W.; Mitchell, M.J.

    2010-01-01

    In many forested headwater catchments, peak SO42 - concentrations in stream water occur in the late summer or fall following drought potentially resulting in episodic stream acidification. The sources of highly elevated stream water SO42 - concentrations were investigated in a first order stream at the Sleepers River watershed (Vermont, USA) after the particularly dry summer of 2001 using a combination of hydrological, chemical and isotopic approaches. Throughout the summer of 2001 SO42 - concentrations in stream water doubled from ???130 to 270 ??eq/L while flows decreased. Simultaneously increasing Na+ and Ca2+ concentrations and ??34S values increasing from +7??? towards those of bedrock S (???+10.5???) indicated that chemical weathering involving hydrolysis of silicates and oxidation of sulfide minerals in schists and phyllites was the cause for the initial increase in SO42 - concentrations. During re-wetting of the watershed in late September and early October of 2001, increasing stream flows were accompanied by decreasing Na+ and Ca2+ concentrations, but SO42 - concentrations continued to increase up to 568 ??eq/L, indicating that a major source of SO42 - in addition to bedrock weathering contributed to peak SO42 - concentrations. The further increase in SO42 - concentrations coincided with an abrupt decrease of ??34S values in stream water SO42 - from maximum values near +10??? to minimum values near -3???. Soil investigations revealed that some C-horizons in the Spodsols of the watershed contained secondary sulfide minerals with ??34S values near -22???. The shift to negative ??34S values of stream water SO42 - indicates that secondary sulfides in C-horizons were oxidized to SO42 - during the particularly dry summer of 2001. The newly formed SO42 - was transported to the streams during re-wetting of the watershed contributing ???60% of the SO42 - during peak concentrations in the stream water. Thereafter, the contribution of SO42 - from oxidation of

  17. Agroforestry practices, runoff, and nutrient loss: a paired watershed comparison.

    Science.gov (United States)

    Udawatta, Ranjith P; Krstansky, J John; Henderson, Gray S; Garrett, Harold E

    2002-01-01

    A paired watershed study consisting of agroforestry (trees plus grass buffer strips), contour strips (grass buffer strips), and control treatments with a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation was used to examine treatment effects on runoff, sediment, and nutrient losses. During the (1991-1997) calibration and subsequent three-year treatment periods, runoff was measured in 0.91- and 1.37-m H-flumes with bubbler flow meters. Composite samples were analyzed for sediment, total phosphorus (TP), total nitrogen (TN), nitrate, and ammonium. Calibration equations developed to predict runoff, sediment, and nutrients losses explained 66 to 97% of the variability between treatment watersheds. The contour strip and agroforestry treatments reduced runoff by 10 and 1% during the treatment period. In both treatments, most runoff reductions occurred in the second and third years after treatment establishment. The contour strip treatment reduced erosion by 19% in 1999, while erosion in the agroforestry treatment exceeded the predicted loss. Treatments reduced TP loss by 8 and 17% on contour strip and agroforestry watersheds. Treatments did not result in reductions in TN during the first two years of the treatment period. The contour strip and agroforestry treatments reduced TN loss by 21 and 20%, respectively, during a large precipitation event in the third year. During the third year of treatments, nitrate N loss was reduced 24 and 37% by contour strip and agroforestry treatments. Contour strip and agroforestry management practices effectively reduced nonpoint-source pollution in runoff from a corn-soybean rotation in the clay pan soils of northeastern Missouri.

  18. Sources of acid and metals from the weathering of the Dinero waste pile, Lake Fork watershed, Leadville, Colorado

    Science.gov (United States)

    Diehl, S.F.; Hageman, Phil L.; Smith, Kathleen S.; Herron, J.T.; Desborough, G.A.

    2005-01-01

    Two trenches were dug into the south Dinero mine-waste pile near Leadville, Colorado, to study the weathering of rock fragments and the mineralogic sources of metal contaminants in the surrounding wetland and Lake Fork Watershed. Water seeping from the base of the south Dinero waste-rock pile was pH 2.9, whereas leachate from a composite sample of the rock waste was pH 3.3. The waste pile was mostly devoid of vegetation, open to infiltration of precipitation, and saturated at the base because of placement in the wetland. The south mine-waste pile is composed of poorly sorted material, ranging from boulder-size to fine-grained rock fragments. The trenches showed both matrix-supported and clast-supported zones, with faint horizontal color banding, suggesting zonation of Fe oxides. Secondary minerals such as jarosite and gypsum occurred throughout the depth of the trenches. Infiltration of water and transport of dissolved material through the pile is evidenced by optically continuous secondary mineral deposits that fill or line voids. Iron-sulfate material exhibits microlaminations with shrinkage cracking and preferential dissolution of microlayers that evidence drying and wetting events. In addition to fluids, submicron-sized to very fine-grained particles such as jarosite are transported through channel ways in the pile. Rock fragments are coated with a mixture of clay, jarosite, and manganese oxides. Dissolution of minerals is a primary source of metals. Skeletal remnants of grains, outlined by Fe-oxide minerals, are common. Potassium jarosite is the most abundant jarosite phase, but Pb-and Ag-bearing jarosite are common. Grain-sized clusters of jarosite suggest that entire sulfide grains were replaced by very fine-grained jarosite crystals. The waste piles were removed from the wetland and reclaimed upslope in 2003. This was an opportunity to test methods to identify sources of acid and metals and metal transport processes within a waste pile. A series of

  19. Degradation State, Sources, and Reactivity of Dissolved Organic Matter from an Amino Acid Time Series in an Agricultural Watershed

    Science.gov (United States)

    Matiasek, S. J.; Pellerin, B. A.; Spencer, R. G.; Bergamaschi, B. A.; Hernes, P.

    2015-12-01

    A detailed time series of dissolved amino acids was obtained in an agricultural watershed in the northern Central Valley, California, USA to investigate the roles of hydrologic and seasonal changes on the composition of dissolved organic matter (DOM). Total hydrolysable amino acid (THAA) concentrations ranged from 0.55 to 9.96 μM (mean 3.76 ± 1.80 μM) and not only peaked with discharge during winter storms, but also remained elevated throughout the irrigation season when discharge was low. Summer irrigation was a critical hydrologic regime for DOM cycling, since it mobilized DOM similar in concentration and reactivity to DOM released during winter storms for an extended period of time, with the largest amino acid contributions to the dissolved organic carbon (DOC) and the dissolved organic nitrogen (DON) pools (3.4 ‒ 3.7 % DOC-AA, 17.4 ‒ 22.5 % DON-AA), the largest proportion of basic amino acids (B/(B+A) = 0.19 ‒ 0.22), and the largest degradation index values (mean 1.37 ± 0.96). The mole percent of non-protein amino acids, commonly considered as an indicator of microbial degradation, decreased with DOM processing and was highest during summer (mean 4.1 ± 1.1%). A lack of correlation between THAA concentrations and UV-Vis absorbance and fluorescence proxies (including "protein-like" fluorophores B and T) indicated that optical properties may be limited in representing amino acid dynamics in this system. A new parameter for DOM processing derived from trends in individual amino acids demonstrated strong potential for inferring the extent of DOM degradation in freshwater systems. The biogeochemical relevance of irrigation practices is heightened by timing, since the additional export of reactive DOM coincides with enhanced downstream DOM processing in the Sacramento-San Joaquin River Delta, a critical habitat for endangered species serving as water source for 25 million Californians.

  20. ASSESSMENT AND CONTROL OF NITROGEN EMISSION FROM AGRICULTURAL NON-POINT SOURCE IN THE URBAN AGGLOMERATION IN THE MIDDLE-LOWER YANGTZE RIVER BELT%长江中下游城市群农业面源污染氮排放评价及调控

    Institute of Scientific and Technical Information of China (English)

    赖敏; 王伟力; 郭灵辉

    2016-01-01

    Nitrogen is an important component of protein and essential element for the growth of aquatic biomass. Excessive nitrogen input to natural water bodies leads to huge ecological pressure and environmental pollutions such as eutrophication. As point source pollution got effective control in the socio-economic system, agricultural non-point source pollution has become the main cause of eutrophication. Quantifying and regulating the agricultural non-point source pollution emissions throughout the entire socio-economic system is crucial to mitigate or avoid pro-ducing water pollution. Based on the inventory analysis method and emission coefficient method, this paper calcu-lated the nitrogen emission from the agricultural non-point source for the Urban Agglomeration in the Middle-Lower Yangtze River Belt. The results showed that the total nitrogen emission from the agricultural non -point source in the whole area was 128. 27 × 104 t in 2011, of which agricultural emission accounted for 58. 92%, and e-mission from livestock and poultry was 33 . 53%. The sensitivity analysis method and scenario analysis method were then applied to simulate the emission situation during 2011 to 2020 and 2020 to 2030 . Some conclusions were drawn as follows:Under scenario 1, if more stringent pollution control efforts were not implemented, the nitrogen e-mission from the agricultural non-point source would increase 16 . 29% during 2011 to 2020 , and 18 . 78% during 2020 to 2030. Under scenario 2 and scenario 3, by contrast, the total nitrogen emission of the four urban agglomer-ations would be 15% fewer in 2020 than in 2011 , and 25% fewer in 2030 than in 2011 . The nitrogen emission re-duction effect in scenario 2 was better than that in scenario 3;Scenario 3 was considered to be more conducive to couple the relationship between regional economic growth and environmental protection. Finally, some recommen-dations were put forward to regional emission reduction, including reducing

  1. Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

    Science.gov (United States)

    Ciparis, S.; Iwanowicz, L.R.; Voshell, J.R.

    2012-01-01

    Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO 4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17??-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations >1ng/L. Relatively high concentrations of DIN (>1000??g/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R 2=0.56-0.81) and E2Eq (R 2=0.39-0.75). Relationships between watershed densities of AFOs and PO 4-P were weaker, but were also significant (R 2=0.27-0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO 4-P than streams without WWTP discharges, and PO 4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms. ?? 2011 Elsevier B.V.

  2. Changing stream water sources from climate-exacerbated insect infestation in forested watersheds: a combined field and multi-scale modeling analysis.

    Science.gov (United States)

    Maxwell, R. M.; Bearup, L. A.; Penn, C. A.; Jefferson, J.; Engdahl, N. B.

    2014-12-01

    Changing climate, including warmer temperatures and drought conditions, has intensified mountain pine beetle infestation in the Rocky Mountains of North America, resulting in tree death over the last decade that is unprecedented in recorded history. The subsequent perturbation to tree-scale water budget processes such as interception, transpiration, and evaporation often combine non-uniformly and produce variable catchment-scale responses. Potentially offsetting perturbations such as decreased transpiration with tree death and increased exposure and evaporation with needle fall can produce changes in peak streamflow and water yield that are undetectable above typical interannual variability. These combined perturbations, however, may change streamflow generating processes and water sources that impact water quality in important mountain headwater streams. To determine the potential impact of widespread land cover change on catchment contributions to streamflow, this study combines a chemical and isotopic separation analysis using paired watersheds and pre-infestation controls with a multi-scale modeling approach (from hillslope to headwaters systems) that determines changes in water stores and fluxes between canopy, land-surface, groundwater and streamflow. Field observations and chemical hydrograph separation analysis suggest that groundwater contributions to streamflow increase with recent insect infestation, as transpiration ceases to remove water from the subsurface but potentially increased ground evaporation removes water from the land and subsurface with relative uniformity. Comparing these field observations to hillslope models provides additional spatial and temporal controls on inherently challenging field heterogeneities as well as a way of testing the influence of natural properties such as precipitation and topography on perturbations to streamflow partitioning from insect infestation. At larger scales, watershed models demonstrate how other factors

  3. Source apportionment and spatial heterogeneity of agricultural non-point source pollution based on water environmental function zoning%基于水环境功能区划的农业面源污染源解析及其空间异质性

    Institute of Scientific and Technical Information of China (English)

    钱晓雍; 沈根祥; 郭春霞; 顾海蓉; 朱英; 王振旗

    2011-01-01

    Taking township as basic unit, the inventory analysis method and equivalent standard method were conducted to determine the discharge amount of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) from different types of agricultural non-point sources, including chemical fertilizer application, animal manure application, crop straws, animal husbandry, aquaculture and rural sewage. The impact of agricultural non-point source pollution (ANPSP) on water environment and its spatial heterogeneity were analyzed based on water environmental function zoning at the scales of county and town. The results indicated that, the absolute discharge amount of COD, TN and TP from ANPSP were 4.42× 104,1.13× 104, 0.44× 104 t/a respectively, and the discharge amount in equivalent standard were 0.16× 104, 0.93 × 104, 1.65× 104 m3/a respectively. The primary pollution source was animal husbandry, which load ratio in equivalent standard reached 66.31%, and the primary pollutant was TP, which load ratio in equivalent standard reached 60.32%. Discharge concentration of COD, TN and TP caused by ANPSP in different districts were in the range of 4.16-40.91, 1.30-8.71, 0.23-4.94 mg/L respectively, while the average water quality index ranged from 0.67 to 5.91. From the point view of town-based pollution stress, the pollution extent of the towns in South Shanghai and Chongming Island was much higher, which had greater agriculture productive value and located near the water conservation area with stricter water quality standards.%通过清单分析方法和等标污染负荷法,以乡镇为单元研究了上海市化肥施用、有机肥施用、农作物秸秆、畜禽养殖、水产养殖、农村生活污水等农业面源污染来源化学需氧量(COD)、总氮(TN)、总磷(TP)等污染物的排放量及其贡献率,并根据各区域水环境功能区划分别在区县尺度和乡镇尺度分析了农业面源污染程度及其区域分布.结果表明,上

  4. Multi-agency analysis of periphyton, fish, and benthic macroinvertebrate communities and the effects of point and non-point sources in the Indian Creek Watershed, Tazewell County, Virginia

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Chemical, physical, and biological indices were used in this study. Water and sediment samples were analyzed for EPA’s priority pollutants. Other measurements such...

  5. Ecological and water quality impairment resulting from the New Idria Mercury Mine and natural sources in the San Carlos and Silver Creek watersheds, central California

    Science.gov (United States)

    Rytuba, J. J.; Hothem, R.; Goldstein, D.; Brussee, B.

    2011-12-01

    The New Idria Mercury Mine in central California is the second largest mercury (Hg) deposit in North America and has been proposed as a US EPA Superfund Site based on ecological impairment to the San Carlos and Silver Creek watersheds. Water, sediment, and biota were sampled in San Carlos Creek in the mine area and downstream for 25 km into the watershed termed Silver Creek. Release of acid rock drainage (ARD) and erosion of mine tailings have impacted the watershed during 120 years of mining and since the mine was closed in 1972. The watershed can be divided into three segments based on water and sediment composition, Hg sources and concentrations, and biodiversity of aquatic invertebrates. Creek waters in segment no. 1 above the mine area consist of Mg-Ca-CO3 meteoric water with pH 8.73. Hg concentrations are elevated in both sediment (100μg/g), and in waters (60 ng/L) because of erosion of Hg mine tailings in the upper part of the watershed. Invertebrate biodiversity is the highest of the sites sampled in the watershed, with seven families (six orders) of aquatic invertebrates collected and six other families observed. In the mine area isotopically heavy ARD (pH 2.7) with high levels of Fe(II), SO4, and total Hg (HgT: 76.7 ng/L) enters and mixes with meteoric creek water, constituting from 10-15% of the water in the 10-km long second creek segment downstream from the mine. Oxidation of Fe(II) from ARD results in precipitation of FeOOH which is transported and deposited as an Fe precipitate that has high Hg and MMeHg concentration (Hg: 15.7-79 μg/g, MMeHg: 0.31 - 1.06 ng/g). Concentrations of HgT are uniformly high (1530-2890 ng/L) with particulate Hg predominant. MMeHg ranges from 0.21-0.99 ng/L. In the area just downstream from the ARD source, biodiversity of invertebrates was low, with only one taxa (water striders) available in sufficient numbers and mass (> 1 g)_to be sampled. Biodiversity further downstream was also low, with only up to 2 families present

  6. Economic total maximum daily load for watershed-based pollutant trading.

    Science.gov (United States)

    Zaidi, A Z; deMonsabert, S M

    2015-04-01

    Water quality trading (WQT) is supported by the US Environmental Protection Agency (USEPA) under the framework of its total maximum daily load (TMDL) program. An innovative approach is presented in this paper that proposes post-TMDL trade by calculating pollutant rights for each pollutant source within a watershed. Several water quality trading programs are currently operating in the USA with an objective to achieve overall pollutant reduction impacts that are equivalent or better than TMDL scenarios. These programs use trading ratios for establishing water quality equivalence among pollutant reductions. The inbuilt uncertainty in modeling the effects of pollutants in a watershed from both the point and nonpoint sources on receiving waterbodies makes WQT very difficult. A higher trading ratio carries with it increased mitigation costs, but cannot ensure the attainment of the required water quality with certainty. The selection of an applicable trading ratio, therefore, is not a simple process. The proposed approach uses an Economic TMDL optimization model that determines an economic pollutant reduction scenario that can be compared with actual TMDL allocations to calculate selling/purchasing rights for each contributing source. The methodology is presented using the established TMDLs for the bacteria (fecal coliform) impaired Muddy Creek subwatershed WAR1 in Rockingham County, Virginia, USA. Case study results show that an environmentally and economically superior trading scenario can be realized by using Economic TMDL model or any similar model that considers the cost of TMDL allocations.

  7. Traditional and Host-Associated Fecal Indicator Bacterial Patterns in Southern California Watersheds: Field Source Identification Studies and Laboratory Microcosms Investigating Presence and Persistence in Water and Sediments

    Science.gov (United States)

    Mika, Kathryn Beth

    Overall, recreational beach water quality remains an issue of concern in Southern California and across the globe. Many factors come into play when determining water quality, including physical issues such as the myriad sources that contribute pollution to the site and financial and political issues that control the way water quality is monitored and determined. Current national regulations require the monitoring of fecal indicator bacteria in order to determine recreational water quality. However, it is also important to identify biological and geographical sources of pollution to consistently impaired locations. A commonly applied approach to meet the goals of source identification is to sample sites that have been high in FIB for further study. A tiered approach such as this, however, assumes a correlation between FIB and the sources of interest in the watershed. The research described in this dissertation tests this assumption in two Southern California watersheds, Santa Monica Canyon and Ventura Harbor. In both cases, a tiered approach to sampling using FIB as a first tier to guide sampling would have failed to identify sources of human fecal pollution (as identified by the presence of the human-associated Bacteroides marker HF183). Every watershed is a distinct environment that has different potential sources of bacteria and many factors contributing to the persistence of the bacteria. Rather than attempting to apply an indicator that has worked as a first tier in other watersheds, it would be better to have as a first tier an in-depth study of the watershed using historical data or local experts to provide information on the most likely sources of pollution in the watershed. Using this information it would be possible to design a study using FIB and one or more source-associated parameters to identify specific sources of pollution in the watershed. In addition, sampling FIB and other parameters such as HF183 allow the application of other microbial source

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

    Directory of Open Access Journals (Sweden)

    Sandeep S. Nerkar

    2014-06-01

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

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

    Science.gov (United States)

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

    2014-06-01

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

  10. Identifying host sources, human health risk and indicators of Cryptosporidium and Giardia in a Canadian watershed influenced by urban and rural activities.

    Science.gov (United States)

    Van Dyke, Michele I; Ong, Corinne S L; Prystajecky, Natalie A; Isaac-Renton, Judith L; Huck, Peter M

    2012-06-01

    Cryptosporidium and Giardia were characterized in a watershed in southern Ontario, Canada, over a 2½ year period. River samples were collected every two weeks, primarily near a municipal drinking water treatment plant intake. Cryptosporidium and Giardia were frequently detected with an overall occurrence rate of 88 and 97%, respectively. Giardia concentrations were higher than Cryptosporidium, with median values of 80 cysts 100 L(-1) and 12 oocysts 100 L(-1), respectively. Although pathogens rarely show a significant relationship with fecal or water quality indicators, this study determined that Cryptosporidium, but not Giardia, was significantly correlated with Escherichia coli, turbidity and river flow. There was no correlation between the two types of protozoa, and only Giardia showed a seasonal trend with higher concentrations at cold water temperatures. Cryptosporidium genotyping of all samples found that farm animals and wildlife were an important contributor of oocysts in the watershed, and that Cryptosporidium strains/genotypes of medium to high risk for human infection (C. hominis, C. parvum and C. ubiquitum) were detected in 16% of samples. This study was able to identify Cryptosporidium host sources and human health risk, and to identify differences between Cryptosporidium and Giardia occurrence in the watershed.

  11. Structural uncertainty in watershed phosphorus modeling: Toward a stochastic framework

    Science.gov (United States)

    Chen, Lei; Gong, Yongwei; Shen, Zhenyao

    2016-06-01

    Structural uncertainty is an important source of model predictive errors, but few studies have been conducted on the error-transitivity from model structure to nonpoint source (NPS) prediction. In this study, we focused on the structural uncertainty caused by the algorithms and equations that are used to describe the phosphorus (P) cycle at the watershed scale. The sensitivity of simulated P to each algorithm/equation was quantified using the Soil and Water Assessment Tool (SWAT) in the Three Gorges Reservoir Area, China. The results indicated that the ratios of C:N and P:N for humic materials, as well as the algorithm of fertilization and P leaching contributed the largest output uncertainties. In comparison, the initiation of inorganic P in the soil layer and the transformation algorithm between P pools are less sensitive for the NPS-P predictions. In addition, the coefficient of variation values were quantified as 0.028-0.086, indicating that the structure-induced uncertainty is minor compared to NPS-P prediction uncertainty caused by the model input and parameters. Using the stochastic framework, the cumulative probability of simulated NPS-P data provided a trade-off between expenditure burden and desired risk. In this sense, this paper provides valuable information for the control of model structural uncertainty, and can be extrapolated to other model-based studies.

  12. 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 = <1) in validation period. We have selected 19 BMPs to estimate their efficacy in terms of water and sediment yields under a combination of three Coupled Model Intercomparison Project-5 Global

  13. Spatial distribution of 137Cs in surface soil under different land uses in Chao Phraya watershed: Potential used as sediment source tracing

    Science.gov (United States)

    Srisuksawad, K.; porntepkasemsan, B.; Noipow, N.; Omanee, A.; Wiriyakitnateekul, W.; Chouybudha, R.; Srimawong, P.

    2015-05-01

    Sediment fingerprinting techniques involves the discrimination of sediment sources based on differences in source material properties and quantification of the relative contributions from these sources to sediment delivered downstream to the river catchments. Results of the previous study indicated that fallout radionuclides (FRNs); 137Cs and excess 210Pb (210Pbex) are the most suitable radionuclides to be used as sediments sources tracers. This study investigated the spatial distribution of 137Cs in soil under different land uses in Chao Phraya watershed; the most significant watershed in Thailand. Emphasis was placed on discriminating among potential sediment sources including the cultivated (upland crops), pasture field, uncultivated (swamp, forest, and grass field), and channel erosion (stream and river bank). One hundred and twenty four soil samples were collected from all sources and determining for 137Cs. The 137Cs mass activities in pasture areas varied from the limit of detection (LLD) to 1.22±0.05 with the average of 0.64±0.14 Bq kg-1. In cultivated areas the 137Cs mass activities varied from LLD to 1.41±0.04 with the average of 0.38±0.04 Bq kg-1. The 137Cs mass activities were higher in uncultivated areas varied from 0.12±0.03 to 1.73±0.05 with the average of 0.76±0.15 Bq kg-1. The 137Cs mass activities in channel bank varied from LLD to 1.16±0.04 with the average of 0.39±0.05 Bq kg-1.GIS and geospatial interpolations revealed pattern in the spatial concentrations of 137Cs and indicated important differences in its distributions showing the differences behaviour of 137Cs in different land uses.

  14. Restoring Anadromous Fish Habitat in Big Canyon Creek Watershed; Anadromous Fish Habitat Restoration in the Nichols Canyon Subwatershed, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Koziol, Deb (Nez Perce Soil and Water Conservation District, Lewiston, ID)

    2002-02-01

    Big Canyon Creek historically provided quality spawning and rearing habitat for A-run wild summer steelhead in the Clearwater River subbasin (Fuller, 1986). However, high stream temperatures, excessive sediment and nutrient loads, low summer stream flows, and little instream cover caused anadromous fish habitat constraints in the creek. The primary sources of these nonpoint source pollution and habitat degradations are attributed to agricultural, livestock, and forestry practices (NPSWCD, 1995). Addressing these problems is made more complex due to the large percentage of privately owned lands in the watershed. Nez Perce Soil and Water Conservation District (NPSWCD) seeks to assist private, tribal, county, and state landowners in implementing Best Management Practices (BMPs) to reduce nonpoint source pollutants, repair poorly functioning riparian zones, and increase water retention in the Nichols Canyon subwatershed. The project funds coordination, planning, technical assistance, BMP design and installation, monitoring, and educational outreach to identify and correct problems associated with agricultural and livestock activities impacting water quality and salmonid survival. The project accelerates implementation of the Idaho agricultural water quality management program within the subwatershed.

  15. Seasonal change detection of riparian zones with remote sensing images and genetic programming in a semi-arid watershed.

    Science.gov (United States)

    Makkeasorn, Ammarin; Chang, Ni-Bin; Li, Jiahong

    2009-02-01

    Riparian zones are deemed significant due to their interception capability of non-point source impacts and the maintenance of ecosystem integrity region wide. To improve classification and change detection of riparian buffers, this paper developed an evolutionary computational, supervised classification method--the RIparian Classification Algorithm (RICAL)--to conduct the seasonal change detection of riparian zones in a vast semi-arid watershed, South Texas. RICAL uniquely demonstrates an integrative effort to incorporate both vegetation indices and soil moisture images derived from LANDSAT 5 TM and RADARSAT-1 satellite images, respectively. First, an estimation of soil moisture based on RADARSAT-1 Synthetic Aperture Radar (SAR) images was conducted via the first-stage genetic programming (GP) practice. Second, for the statistical analyses and image classification, eight vegetation indices were prepared based on reflectance factors that were calculated as the response of the instrument on LANDSAT. These spectral vegetation indices were then independently used for discriminate analysis along with soil moisture images to classify the riparian zones via the second-stage GP practice. The practical implementation was assessed by a case study in the Choke Canyon Reservoir Watershed (CCRW), South Texas, which is mostly agricultural and range land in a semi-arid coastal environment. To enhance the application potential, a combination of Iterative Self-Organizing Data Analysis Techniques (ISODATA) and maximum likelihood supervised classification was also performed for spectral discrimination and classification of riparian varieties comparatively. Research findings show that the RICAL algorithm may yield around 90% accuracy based on the unseen ground data. But using different vegetation indices would not significantly improve the final quality of the spectral discrimination and classification. Such practices may lead to the formulation of more effective management strategies

  16. A simple laboratory project for introducing nonpoint source pollution concept to students of environmental and agricultural related courses Uma experiência laboratorial simples para introduzir o conceito de poluição disseminada a estudantes das áreas do ambiente e agricultura

    Directory of Open Access Journals (Sweden)

    M.M. Vidal

    2009-01-01

    Full Text Available This paper reports a simple laboratory project to introduce students to the nonpoint source pollution, which may be an issue of great interest to both undergraduate and graduate students of environmental or agricultural chemistry courses. The aim of this work is introduce to the students the concepts and techniques such as the polymericbased controlled release system of an agrochemical, theory of diffusion (first Fick law and spectrophotometric analysis. Thus, this laboratory project includes three experimental modules to be conducted during three weeks. Programmatic contents are described in this proceeding. Students must be aware that dissemination of nutrients and pesticides is prone to occur by both surface runoff and groundwater leaching, causing damages on all neighboring land. To demonstrate dissemination of such pollutants, we have chosen inorganic phosphorus as example of a common agrochemical. Students are invited to follow the eventual movement of the inorganic P into the groundwater. With this purpose, gelatin gels containing inorganic P were prepared to obtain a continuous release of inorganic P at a controlled rate. The slow release of P allows fewer applications and less active ingredient needed, helping to prevent leaching, with consequent reduction of groundwater contamination. At this point, students are able to compare the advantages of slow release inorganic P vs. its application by conventional methods.Este trabalho descreve uma experiência laboratorial simples para introduzir o conceito de poluição disseminada (nonpoint source pollution a estudantes do Ensino Secundário e Universitário das áreas de Ambiente e de Agricultura. O objectivo deste trabalho é introduzir aos estudantes conceitos e técnicas, tais como os sistemas de libertação controlada, a teoria da difusão (1ª lei de Fick e a análise espectrofotomética. Este projecto laboratorial inclui três módulos experimentais a serem efectuados durante 3

  17. 基于排水过程分析的水稻灌区农田面源污染模拟%Simulation of agricultural non-point source pollution from paddy rice irrigation district based on analyses of drainage processes

    Institute of Scientific and Technical Information of China (English)

    陈会; 王康; 周祖昊

    2012-01-01

    对前郭灌区主要面源污染物迁移、转化及汇集过程开展了2a的系统试验与监测,模拟了灌区面源污染水质水量过程,分析了灌区农田面源污染形成机制.水均衡测定结果表明,灌区排水主要由灌溉退水、稻田地表弃水和稻田渗流排水3部分组成,采用马斯京根法和连续分段马斯京根法能够有效地模拟各级排水沟道的排水过程.主要面源污染物随水体发生迁移及掺混,采用一级动力学方法描述污染物转化过程,模拟的灌区水质水量过程与实际过程符合较好,稻田地表退水主要影响水稻抽穗前的面源污染入河过程,而渗流排水则在抽穗后灌区排水水质中起主要作用.结果表明水稻灌区中地表排水和稻田渗漏排水对于面源污染过程起主要作用.%The transport and transformation processes of non-point source pollutions form paddy rice field to the main drainage canal through lateral and branch drainage canals were monitored in the Qianguo irrigation district during the rice growing seasons in 2009 and 2010. Water balance were measured in lateral canal in the controlled irrigation region. Results showed that the drainage water were composed of the rice field surface returned water, the irrigation returned water and the seepage from rice field to the drainage canals. Drainage processes in branch and main canal were simulated using the Muskingum method and the Muskingum segmentation flow routing method, respectively. The transport processes of chemical concentrations were determined by the mix and convection of water flow and the transformation processes were described using the first order kinetic equation. Drainage processes and contaminant concentration simulated showed good agreements with the measured values. The returned water and seepage from rice field played key roles in the process of agricultural non point pollution into the river. This research suggested the surface drainage and seepage

  18. Near-Channel Sediment Sources Now Dominate in Many Agricultural Landscapes: The Emergence of River-Network Models to Guide Watershed Management

    Science.gov (United States)

    Czuba, J. A.; Foufoula-Georgiou, E.; Gran, K. B.; Belmont, P.; Wilcock, P. R.

    2015-12-01

    Detailed sediment budgets for many agricultural watersheds are revealing a surprising story - that sediment is no longer primarily sourced from upland fields, but instead from near-channel sources. This is the case for the Minnesota River Basin (MRB) where an intensification and expansion of agricultural drainage combined with increased precipitation has (1) reduced surface runoff and erosion, (2) amplified streamflows, and (3) accelerated both near-channel sediment generation and sediment transport. Bluffs and streambanks in the MRB are now the dominant sources of sediment, but these features are not easily incorporated into traditional watershed-scale, sediment-transport models. Instead, we are advancing a network-based modeling framework that explicitly considers sediment sources, transport, and storage along a river network. We apply this framework to bed-material sediment transport in the Greater Blue Earth River Basin, the major sediment-generating subbasin of the MRB, where a recent sediment budget has quantified the locations and rates of erosion and deposition of major sediment sources and sinks (i.e., bluffs, streambanks/floodplains, agricultural fields, and ravines) over millennial and decadal timescales. With the river network as the basis of a simple model, inputs of sediment to the network are informed by the sediment budget and these inputs are tracked through the network using process-based time delays that incorporate uniform-flow hydraulics and at-capacity sediment transport. We explore how this sediment might move through the network and affect the variability of bed elevations under cases where the mechanisms of in-channel and floodplain storage are turned on and off. We will discuss timescales of movement of sediment through the system to better inform legacy effects and hysteresis, and also discuss targeted management actions that will most effectively reduce the detrimental effects of excess sediment.

  19. Source tracing of fluvial suspended sediments by magnetic and geochemical particle characterization: example of the Canche watershed (Nord-Pas-de-Calais, France)

    Science.gov (United States)

    Patault, Edouard; Alary, Claire; Franke, Christine; Gauthier, Arnaud; Abriak, Nor-Edine

    2016-04-01

    In France, erosion by water run-off is estimated to 1.5 t ha-1yr-1 and can exceed 10 t ha-1yr-1 in large growing areas, such as the North of France (Nord-Pas-de-Calais). In this region, the Canche watershed (1294 km2) sustains heavy loss of fertile soils. The land use is mainly dominated by arable lands (80%) and in 2013, 104 kt of suspended sediment transited to the estuary. As demonstrated in literature, agricultural soil erosion leads to the gradual disappearance and depletion of fertile soil, which constitute a non-renewable resource at human time scale. Additionally, water erosion can significantly damage the aquatic habitat and can be responsible for the input of nutrients, bacteria, pesticides, heavy metals and radionuclides into surface waters. Conscious of these effects, many programs have emerged in the Nord-Pas-de-Calais to reduce erosion. This study presents a combination of environmental magnetic proxy parameters and geochemical analyses on sediments and suspended particulate matter. The aim is to develop effective tools to trace erosion by water run-off and quantify this process. In order to identify the respective sediment sources in the Canche watershed, sediment trap samples of suspended particulate matter were recovered at key positions along the Canche watershed. The preliminary results show that magnetic concentration (Mrs) shows typical values for the agricultural soils in the region, but these variations in magnetic concentrations and total irons concentrations are not always correlated, which may be explained by the iron speciation. In calculating the so-called S-ratio for each sample we can distinguish changes in magneto-mineralogy (and thus iron speciation) from magnetite-dominated assemblages in the mainstream Canche (naturel background signal) to high-coercivity-dominated assemblages in the tributaries, typical for soil erosion material rich in hematite/goethite. In combination with the element concentrations from ICP analyses, this proxy

  20. 考虑面源污染的中国苹果全要素生产率及其空间集聚特征分析%Total factor productivity of apple industry in China considering non-point source pollution and its spatial concentration analysis

    Institute of Scientific and Technical Information of China (English)

    冯晓龙; 霍学喜

    2015-01-01

    Apple industry has become a major industry of rural economy in most of the north region in China, which plays an important role on the adjustment of agricultural structure, the increase of farmer’s income and the export. But overall, the development of apple industry still has belonged to the traditional production style depending on fertilizer and pesticide; on one side it has brought high economic benefits for farmers, and on the other side it has been the main reason to agricultural non-point source pollution. There is no doubt that this production style has exacerbated the contradiction between the development of apple industry and the ecological environment in China. Therefore, in order to achieve the sustainable development of apple industry, the transformation of the development mode of apple industry, the improvement of resource use efficiency and the effective control of non-point source pollution in apple production should be taken into account urgently. And to achieve these goals are closely dependent on the contribution of apple total factor productivity to industry development, the reasonable estimation of apple total factor productivity, and thus the guide of the correct policy. Using the unit investigation and evaluation model, this paper calculates the non-point source pollution from apple industry, which is taken as non-ideal output and integrated into the model of total factor productivity, then analyzes the total factor productivity of apple industry under the constraint of environment of 21 provinces in China from 1994 to 2013 by applying the Malmquist-Luenberger productivity index, and finally tests the spatial autocorrelation of total factor productivity of apple industry by using Moran’s index. The results show as follows: 1) Apple total factor productivity index under the constraint of environment is lower than that without this constraint, implying that environment pollution has obvious negative effects on apple productivity in China

  1. Spatio-Temporal Patterns and Source Identification of Water Pollution in Lake Taihu (China

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2016-03-01

    Full Text Available Various multivariate methods were used to analyze datasets of river water quality for 11 variables measured at 20 different sites surrounding Lake Taihu from 2006 to 2010 (13,200 observations, to determine temporal and spatial variations in river water quality and to identify potential pollution sources. Hierarchical cluster analysis (CA grouped the 12 months into two periods (May to November, December to the next April and the 20 sampling sites into two groups (A and B based on similarities in river water quality characteristics. Discriminant analysis (DA was important in data reduction because it used only three variables (water temperature, dissolved oxygen (DO and five-day biochemical oxygen demand (BOD5 to correctly assign about 94% of the cases and five variables (petroleum, volatile phenol, dissolved oxygen, ammonium nitrogen and total phosphorus to correctly assign >88.6% of the cases. In addition, principal component analysis (PCA identified four potential pollution sources for Clusters A and B: industrial source (chemical-related, petroleum-related or N-related, domestic source, combination of point and non-point sources and natural source. The Cluster A area received more industrial and domestic pollution-related agricultural runoff, whereas Cluster B was mainly influenced by the combination of point and non-point sources. The results imply that comprehensive analysis by using multiple methods could be more effective for facilitating effective management for the Lake Taihu Watershed in the future.

  2. 基于“压力-响应”机制的江苏省农业面源污染源解析及其空间特征%Spatial Distribution Characteristics and Source Origin of Agricultural Non-point Source Pollution in Jiangsu Province Based on Pressure-response System

    Institute of Scientific and Technical Information of China (English)

    陆尤尤; 胡清宇; 段华平; 卞新民

    2012-01-01

    运用清单分析、等标负荷和聚类分析等方法,对江苏省农业面源污染源、影响因子、空间分布特征等进行了分析与评价.结果表明:江苏省农业面源污染化学需氧量(COD)、全氮(TN)、全磷(TP)绝对实物排放量分别为155.23×104 t/a、62.34×104 t/a、9.05×104t/a,相应的绝对等标排放量分别为7.76×104 t/a、62.34×104 t/a、45.23×104t/a.农业面源污染造成的COD、TN、TP的平均排放浓度分别为6.25 mg/L、2.53mg/L、0.36 mg/L,排放浓度地区差异显示苏北>苏中>苏南.农业面源污染综合水质指数显示,江苏省均值为2.10,达到中度污染水平.其中徐州、连云港、宿迁处于严重污染状态;淮安、盐城、泰州处于中度污染状态;南通、扬州处于轻度污染状态;南京处于警戒状态;无锡、常州、苏州、镇江处于安全状态.主要污染物依次是TN、TP,其贡献率分别为54.71%和38.86%;主要污染源依次是化肥施用、畜禽养殖、人粪尿、水产养殖,其贡献率分别为30.75%、24.94%、16.85%、15.28%;在国土面积、农业产值和农村人口几大因子中,农业产值是与污染物排放量相关性程度最高的因子.通过对”压力-响应”的表征量进行聚类分析得出江苏省农业面源污染的空间分布特征,其压力和响应基本一致.%The primary source, influence factors, and spatial distribution characteristics of agricultural non-point source pollution (NPSP) in Jiangsu Province were analyzed by inventory analysis, equivalent standard load, and cluster analysis methods. Results showed that the absolute real emissions of COD, TN and TP from NPSP were 155.23× 104t/a, 62.34×l04t/a and 9.05×l04t/a respectively. And the related standard emissions were 7.76×104 t/a, 62.34×104t/a and 45.23×104 t/a. The average concentrations of COD, TN and TP emitted from NPSP were 6.25 mg/L, 2.53 mg/L, 0.36 mg/L, respectively. The concentrations of these

  3. Tailored Watershed Assessment and Integrated Management (TWAIM: A Systems Thinking Approach

    Directory of Open Access Journals (Sweden)

    Joe Magner

    2011-06-01

    Full Text Available Control of non-point source (NPS water pollution remains elusive in the United States (US. Many US water-bodies which have been primarily impacted by NPS pollution have not achieved water quality goals set by Clean Water Act. Technological advances have been made since 1972, yet many water resources fail to meet water quality standards. Common Pool Resources Theory is considered to understand the human dimension of NPS pollution by exploring anthropogenic activities superimposed upon dynamic ecosystems. In the final analysis, priority management zones (PMZs for best management practice (BMP implementation must have buy-in from land managers. TWAIM is an iterative systems thinking approach to planning, collecting landscape and land use information and communicating systems understanding to stakeholders. Hydrologic pathways that link the physical, chemical and biological characteristics influence processes occurring in a watershed which drive stream health and ecological function. With better systems understanding and application by technical specialists, there is potential for improved stakeholder interaction and dialogue which could then enable better land use decisions. Issues of pollutant origin, transport, storage and hydraulic residence must be defined and communicated effectively to land managers within a watershed context to observe trends in water quality change. The TWAIM concept provides a logical framework for locally-led assessment and a means to communicate ecohydrologic systems understanding over time to the key land managers such that PMZs can be defined for BMP implementation.

  4. Application of the SUSTAIN Model to a Watershed-Scale Case for Water Quality Management

    Directory of Open Access Journals (Sweden)

    Chi-Feng Chen

    2014-11-01

    Full Text Available Low impact development (LID is a relatively new concept in land use management that aims to maintain hydrological conditions at a predevelopment level without deteriorating water quality during land development. The United States Environmental Protection Agency (USEPA developed the System for Urban Stormwater Treatment and Analysis Integration model (SUSTAIN to evaluate the performance of LID practices at different spatial scales; however, the application of this model has been limited relative to LID modeling. In this study, the SUSTAIN model was applied to a Taiwanese watershed. Model calibration and verification were performed, and different types of LID facilities were evaluated. The model simulation process and the verified model parameters could be used in other cases. Four LID scenarios combining bioretention ponds, grass swales, and pervious pavements were designed based on the land characteristics. For the SUSTAIN model simulation, the results showed that pollution reduction was mainly due to water quantity reduction, infiltration was the dominant mechanism and plant interception had a minor effect on the treatment. The simulation results were used to rank the primary areas for nonpoint source pollution and identify effective LID practices. In addition to the case study, a sensitivity analysis of the model parameters was performed, showing that the soil infiltration rate was the most sensitive parameter affecting the LID performance. The objectives of the study are to confirm the applicability of the SUSTAIN model and to assess the effectiveness of LID practices in the studied watershed.

  5. Phosphorus export by runoff from agricultural field plots with different crop cover in Lake Taihu watershed

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Runoff and soil losses from agricultural fields are investigated as major nonpoint sources of phosphorus (P) entering lakes of Eastern China. There is relatively little information on P transport from ricefield and cropland of Lake Taihu watershed in Eastern China. Soil and P in surface runoff from a series of plots in the watershed were evaluated under simulated rainfall conditions. The objectives of this study were to evaluate theeffects of crop cover, slope, and fertilizer application on P concentrations in surface runoff and eroded soil. Accumulated sediment yields varied from 7.1 to 300 g/m2 for croplands, depending on management practices. For all experiment plots, weighted average concentrations of total-P (TP), dissolved P (DP) and particulate P (PP) are much higher than 0.02 mg/L, the limiting concentration in lake water. This result showed the potential contamination of lake water from agricultural surface runoff. Accumulated TP losses were 3.8 and 18.8 mg/m2 for ricefield and cropland, respectively. The estimated annual loss of TP was 0.74 kg/(hm2鷄) for cropland. Most of P loss is in PP form, which accounts for more than 90% of TP loss for cropland.

  6. Modeling hydrology, groundwater recharge and non-point nitrate loadings in the Himalayan Upper Yamuna basin.

    Science.gov (United States)

    Narula, Kapil K; Gosain, A K

    2013-12-01

    The mountainous Himalayan watersheds are important hydrologic systems responsible for much of the water supply in the Indian sub-continent. These watersheds are increasingly facing anthropogenic and climate-related pressures that impact spatial and temporal distribution of water availability. This study evaluates temporal and spatial distribution of water availability including groundwater recharge and quality (non-point nitrate loadings) for a Himalayan watershed, namely, the Upper Yamuna watershed (part of the Ganga River basin). The watershed has an area of 11,600 km(2) with elevation ranging from 6300 to 600 m above mean sea level. Soil and Water Assessment Tool (SWAT), a physically-based, time-continuous model, has been used to simulate the land phase of the hydrological cycle, to obtain streamflows, groundwater recharge, and nitrate (NO3) load distributions in various components of runoff. The hydrological SWAT model is integrated with the MODular finite difference groundwater FLOW model (MODFLOW), and Modular 3-Dimensional Multi-Species Transport model (MT3DMS), to obtain groundwater flow and NO3 transport. Validation of various modules of this integrated model has been done for sub-basins of the Upper Yamuna watershed. Results on surface runoff and groundwater levels obtained as outputs from simulation show a good comparison with the observed streamflows and groundwater levels (Nash-Sutcliffe and R(2) correlations greater than +0.7). Nitrate loading obtained after nitrification, denitrification, and NO3 removal from unsaturated and shallow aquifer zones is combined with groundwater recharge. Results for nitrate modeling in groundwater aquifers are compared with observed NO3 concentration and are found to be in good agreement. The study further evaluates the sensitivity of water availability to climate change. Simulations have been made with the weather inputs of climate change scenarios of A2, B2, and A1B for end of the century. Water yield estimates under

  7. Advances on agricultural non-point source pollution and the control in regions around Hung-tse Lake%环洪泽湖区域农业面源污染特征及控制对策

    Institute of Scientific and Technical Information of China (English)

    徐勇峰; 陈子鹏; 吴翼; 朱咏莉; 李萍萍

    2016-01-01

    Hung⁃tse Lake, located in the northwest of Jiangsu Province, is the fourth largest freshwater lake in China. It is also one of the key hinge lakes in the east route of the south⁃to⁃north water transfer project. However, the water quality for the lake was worse than grade Ⅴ according to the Environmental Quality Standard of Surface Water of the People�s Republic of China. Non⁃point source pollution around the lake was considered one of the main reasons. In the present study, the feature, sources, inducement, control and management of agricultural non⁃point pollution around the lake were reviewed. We held that the unreasonable application of chemical fertilizer was the largest source of the pollution. Aquaculture pollution was substantially increasing due to the facts of the ineffective management to enclosure culture and the abuse of exogenous diets. In addition, the emissions of livestock and poultry breeding, rural sewage and unordered waste management were the main contributors of the pollution. Therefore, the control strategies for the agricultural non⁃point source pollution in the regions should focused on ① developing ecological agriculture with reasonable applications of fertilizer and pesticides,②integrating and optimizing the aquaculture,③improving the treatment of rural sewage and recycling of agricultural wastes,④ reducing pollution by enhancing the land use among farmlands, woodlands and wet⁃lands.%洪泽湖是位于江苏省西北部的我国第四大淡水湖泊,同时是南水北调东线工程的重要节点湖泊。然而,目前洪泽湖水质总体状况仍呈下降趋势,其中面源污染是重要原因之一。笔者对环洪泽湖地区农业面源污染的特点、来源与诱因以及控制技术等进行系统评述,分析认为:不合理的化肥施用是该区域第一大面源污染来源;围网养殖区无序规划及大量外源性饵料的投加,使得水产养殖的污染排放呈现增加趋

  8. Distance-decay patterns of nutrient loading at watershed scale: Regression modeling with a special spatial aggregation strategy

    Science.gov (United States)

    Zhang, Tao

    2011-05-01

    SummaryThe effect of distance-decay on nutrient flux usually plays an important role in nutrient retention from non-point sources to surface waters. However, the distance-decay effect has been inappropriately neglected in many studies that adopted regression modeling method to quantify the relationship between watershed landscape and in-stream nutrient loading level. The goal of this study was to develop non-linear regression models that better quantify the role of distance on non-point source nutrient loads in rivers by using simulation results of a spatially-explicit model applied to the watersheds in the Upper Chattahoochee River Basin, Georgia. Because a detailed spatially-explicit modeling approach typically simulates the nutrient flux across the entire watershed, it provides opportunities to examine the nutrient decay patterns at watershed scale. The simulation results confirmed that regarding the effect of flow distance on nutrient loading, the exponential decay setting in the spatially-explicit model performs well. Other heterogeneous factors including slope and soil conditions do affect the decay results but not strongly enough to change the general exponential patterns. The nutrient contribution from areas that were greater than 300 meters to the river network was negligible. It was also found that the decay rate for urban lands is lower than that for other land-covers. Based on these findings, a spatial aggregation strategy in the lateral dimension of the river network was adopted and eight non-linear regression models which explicitly addressed the effects of distance-decay were designed to estimate the nutrient annual average loads. The model validation results showed that three of them can well estimate the nutrient loads. This study shows the usage of stream-lateral-dimension aggregation strategy in addressing nutrient distance-decay patterns and developing simple regression models of nutrient loading. This study also illustrates the advantages of

  9. Watershed District

    Data.gov (United States)

    Kansas Data Access and Support Center — Boundaries show on this map are derived from legal descriptions contained in petitions to the Kansas Secretary of State for the creation or extension of watershed...

  10. Watershed Investigations

    Science.gov (United States)

    Bodzin, Alec; Shive, Louise

    2004-01-01

    Investigating local watersheds presents middle school students with authentic opportunities to engage in inquiry and address questions about their immediate environment. Investigation activities promote learning in an investigations interdisciplinary context as students explore relationships among chemical, biological, physical, geological, and…

  11. The Empirical Analysis of EKC on Agricultural Non-Point Source Pollution in Chongqing%重庆市农业面源污染源的 EKC实证分析

    Institute of Scientific and Technical Information of China (English)

    刘志欣; 邵景安; 李阳兵

    2015-01-01

    Based on the Environmental Kuznets Curve theory and the data from 2000-2012 of Chongqing , five indexes ,w hich are related to the agricultural non‐point source pollution ,are selected as variances and the Environmental Kuznets Curve model are established to analyze the relationship between agricultural non‐point source pollution and the agricultural economic growth .Meanwhile ,use the software of Eviews 7 .0 and SPSS 17 .0 to estimate the parameters .The conclusions can be drawn as follows :1) The chemical fertilizer application level ,the pesticide application level and the emission density of crop residues exhibited typical inverted‐U shaped curve relations with the per capita agricultural net income of farmers .And the chemical fertilizer application level ,pesticide application level and the emission density of crop residues have reduced with the agricultural economic grow th .2) During the study period ,the agricultural films ap‐plication level exhibited liner relations with the per capita agriculture net income of farmers .With the grow th of agricultural economy ,the environmental pressure caused by agricultural films will be further in‐creased .3) The pig droppings equivalent emission density of livestock and poultry manure with the per ca‐pita agricultural net income of farmers exhibited “N”shaped curve characteristics ,the curve exists two in‐flection points .Currently it’s on the right side of the second inflection point and it indicates that the envi‐ronmental pressure caused by livestock and poultry manure pollution will deteriorate again with the devel‐opment of agricultural economy .The government should take effective measures to strengthen the agricul‐tural non‐point source pollution control .%基于环境库兹涅茨曲线理论,根据重庆市2000-2012年的时序数据,选取5个与农业面源污染有关的指标作为污染变量,分析农业面源污染与农业经济增长的关系,并利用EVIEWS7.0

  12. Assessment of Giardia and Cryptosporidium spp. as a microbial source tracking tool for surface water: application in a mixed-use watershed.

    Science.gov (United States)

    Prystajecky, Natalie; Huck, Peter M; Schreier, Hans; Isaac-Renton, Judith L

    2014-04-01

    Knowledge of host specificity, combined with genomic sequencing of Giardia and Cryptosporidium spp., has demonstrated a microbial source tracking (MST) utility for these common waterborne microbes. To explore the source attribution potential of these pathogens, water samples were collected in a mixed rural-urban watershed in the Township of Langley, in southwestern British Columbia (BC), Canada, over a 2-year period. Cryptosporidium was detected in 63% of surface water samples at concentrations ranging from no positive detection (NPD) to 20,600 oocysts per 100 liters. Giardia was detected in 86% of surface water samples at concentrations ranging from NPD to 3,800 cysts per 100 liters of water. Sequencing at the 18S rRNA locus revealed that 50% of Cryptosporidium samples and 98% of Giardia samples contained species/genotypes (Cryptosporidium) or assemblages (Giardia) that are capable of infecting humans, based on current knowledge of host specificity and taxonomy. Cryptosporidium genotyping data were more promising for source tracking potential, due to the greater number of host-adapted (i.e., narrow-host-range) species/genotypes compared to Giardia, since 98% of Giardia isolates were zoonotic and the potential host could not be predicted. This report highlights the benefits of parasite genomic sequencing to complement Method 1623 (U.S. Environmental Protection Agency) and shows that Cryptosporidium subtyping for MST purposes is superior to the use of Giardia subtyping, based on better detection limits for Cryptosporidium-positive samples than for Giardia-positive samples and on greater host specificity among Cryptosporidium species. These additional tools could be used for risk assessment in public health and watershed management decisions.

  13. Healthy Watersheds Protection

    Science.gov (United States)

    Jump to main content US EPA United States Environmental Protection Agency Search Search Healthy Watersheds Protection (HWP) Share ... live in a watershed — thus watershed condition is important to everyone. Watersheds exist at different geographic scales, ...

  14. Amazonian former gold mined soils as a source of methylmercury: evidence from a small scale watershed in French Guiana.

    Science.gov (United States)

    Guedron, Stephane; Grimaldi, Michel; Grimaldi, Catherine; Cossa, Daniel; Tisserand, Delphine; Charlet, Laurent

    2011-04-01

    Total mercury (HgT) and monomethylmercury (MMHg) were investigated in a tropical head watershed (1 km(2)) of French Guiana. The watershed includes a pristine area on the hill slopes and a former gold mined flat in the bottomland. Concentrations of dissolved and particulate HgT and MMHg were measured in rain, throughfall, soil water and at three points along the stream. Samples were taken in-between and during 14 storm events at the beginning and middle of the 2005 and 2006 rainy seasons. Dissolved and particulate HgT concentrations in the stream slightly increased downstream, while dissolved and particulate MMHg concentrations were low at the pristine sub-watershed outlet (median = 0.006 ng L(-1) and 1.84 ng g(-1), respectively) and sharply increased at the gold mined flat outlet (median = 0.056 ng L(-1) and 6.80 ng g(-1), respectively). Oxisols, which are dominant in the pristine area act as a sink of HgT and MMHg from rain and throughfall inputs. Hydromorphic soils in the flat are strongly contaminated with Hg (including Hg(0) droplets) and their structure has been disturbed by former gold-mining processes, leading to multiple stagnant water areas where biogeochemical conditions are favorable for methylation. In the former gold mined flat high dissolved MMHg concentrations (up to 0.8 ng L(-1)) were measured in puddles or suboxic soil pore waters, whereas high dissolved HgT concentrations were found in lower Eh conditions. Iron-reducing bacteria were suggested as the main methylators since highest concentrations for dissolved MMHg were associated with high dissolved ferrous iron concentrations. The connection between saturated areas and stagnant waters with the hydrographic network during rain events leads to the export of dissolved MMHg and HgT in stream waters, especially at the beginning of the rainy season. As both legal and illegal gold-mining continues to expand in French Guiana, an increase in dissolved and particulate MMHg emissions in the hydrographic

  15. Including non-point sfources in a water quality trading permit program.

    Science.gov (United States)

    Collentine, D

    2005-01-01

    There has been overwhelming interest in addressing water quality issues through the use of economic instruments. Much of this attention has focused on the cost efficiencies offered by Transferable Discharge Permit (TDP) systems. Unfortunately, the attempts to start up permit markets which are able to exploit abatement cost differences between sources have not met with the success expected. Two of the reasons for the lack of success that have been taken up in analysis of these programs have been the problem of transaction costs and in the case of non-point sources (NPS), undefined property rights. The composite market design is a proposal for a TDP system which specifically includes agricultural non-point source (NPS) dischargers and addresses both property rights and transaction cost problems. The composite market consists of three interrelated markets each serving a particular function. When the composite market is mature, the total number of permits issued represents the cap on discharges allowed in the catchment. The structure of the composite market allows this system to be phased in over time with existing institutions and limited demands on financing.

  16. Using the soil and water assessment tool to estimate achievable water quality targets through implementation of beneficial management practices in an agricultural watershed.

    Science.gov (United States)

    Yang, Qi; Benoy, Glenn A; Chow, Thien Lien; Daigle, Jean-Louis; Bourque, Charles P-A; Meng, Fan-Rui

    2012-01-01

    Runoff from crop production in agricultural watersheds can cause widespread soil loss and degradation of surface water quality. Beneficial management practices (BMPs) for soil conservation are often implemented as remedial measures because BMPs can reduce soil erosion and improve water quality. However, the efficacy of BMPs may be unknown because it can be affected by many factors, such as farming practices, land-use, soil type, topography, and climatic conditions. As such, it is difficult to estimate the impacts of BMPs on water quality through field experiments alone. In this research, the Soil and Water Assessment Tool was used to estimate achievable performance targets of water quality indicators (sediment and soluble P loadings) after implementation of combinations of selected BMPs in the Black Brook Watershed in northwestern New Brunswick, Canada. Four commonly used BMPs (flow diversion terraces [FDTs], fertilizer reductions, tillage methods, and crop rotations), were considered individually and in different combinations. At the watershed level, the best achievable sediment loading was 1.9 t ha(-1) yr(-1) (89% reduction compared with default scenario), with a BMP combination of crop rotation, FDT, and no-till. The best achievable soluble P loading was 0.5 kg ha(-1) yr(-1) (62% reduction), with a BMP combination of crop rotation and FDT and fertilizer reduction. Targets estimated through nonpoint source water quality modeling can be used to evaluate BMP implementation initiatives and provide milestones for the rehabilitation of streams and rivers in agricultural regions.

  17. A Summary of Best Management Practices for Nonpoint Source Pollution

    Science.gov (United States)

    1992-08-01

    with a. temporary seeding. b. permanent seeding. c. mulching. d. sod, trees, shrubs, vines , and ground cover. 35. Dikes and bermns or level spreaders...tree pruning . Maintenance inspe~ctionts should be used to aiXentify any routine maintenance requirements. Nonroutine maintenance practices involve the...sediments from the inlets could be done manually or hy a vacuum pump. Tree Pruning . The trees adjacent to any infiltration trench may need to be

  18. Reconnaissance survey of nonpoint source pesticides in Maryland surface waters

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — As part of the Chesapeake Bay Agreement, the "Maryland Toxics Reduction Strategy for the Chesapeake Bay and its Tributaries" committed the State to identify the most...

  19. Nonpoint Source Pollution Taxes and Excessive Tax Burden

    Energy Technology Data Exchange (ETDEWEB)

    Karp, L. [Department of Agricultural and Resource Economics, University of California, 207 Giannini Hall, Berkeley, CA 94720 (United States)

    2005-06-01

    If a regulator is unable to measure firms individual emissions, an ambient tax can be used to achieve the socially desired level of pollution. With this tax, each firm pays a unit tax on aggregate emissions. In order for the tax to be effective, firms must recognize that their decisions affect aggregate emissions. When firms behave strategically with respect to the tax-setting regulator, under plausible circumstances their tax burden is lower under an ambient tax, relative to the tax which charges firms on the basis of individual emissions. Firms may prefer the case where the regulator is unable to observe individual firm emissions, even if this asymmetric information causes the regulator to tax each firm on the basis of aggregate emissions.

  20. Literature Review: Computer Aided Assessment Techniques for Nonpoint Source Discharges

    Science.gov (United States)

    1991-04-01

    Equilibrium Metals Speciation Model ( MINTEQ ) is a highly specialized model for metals only. It produces highly precise results, but requires a high level of...dynamic model that can be used for evaluating the behavior of syn- thetic organic chemicals in lakes, rivers and estuaries. 5. MINTEQ : The...conventional pollutants in surface and ground waters," Part I and Part 2, EPA-600/685/002a,b, Washington, DC, 1985. (1987a). " MINTEQAl : An equilibrium

  1. Modeling runoff and erosion risk in a~small steep cultivated watershed using different data sources: from on-site measurements to farmers' perceptions

    Science.gov (United States)

    Auvet, B.; Lidon, B.; Kartiwa, B.; Le Bissonnais, Y.; Poussin, J.-C.

    2015-09-01

    This paper presents an approach to model runoff and erosion risk in a context of data scarcity, whereas the majority of available models require large quantities of physical data that are frequently not accessible. To overcome this problem, our approach uses different sources of data, particularly on agricultural practices (tillage and land cover) and farmers' perceptions of runoff and erosion. The model was developed on a small (5 ha) cultivated watershed characterized by extreme conditions (slopes of up to 55 %, extreme rainfall events) on the Merapi volcano in Indonesia. Runoff was modelled using two versions of STREAM. First, a lumped version was used to determine the global parameters of the watershed. Second, a distributed version used three parameters for the production of runoff (slope, land cover and roughness), a precise DEM, and the position of waterways for runoff distribution. This information was derived from field observations and interviews with farmers. Both surface runoff models accurately reproduced runoff at the outlet. However, the distributed model (Nash-Sutcliffe = 0.94) was more accurate than the adjusted lumped model (N-S = 0.85), especially for the smallest and biggest runoff events, and produced accurate spatial distribution of runoff production and concentration. Different types of erosion processes (landslides, linear inter-ridge erosion, linear erosion in main waterways) were modelled as a combination of a hazard map (the spatial distribution of runoff/infiltration volume provided by the distributed model), and a susceptibility map combining slope, land cover and tillage, derived from in situ observations and interviews with farmers. Each erosion risk map gives a spatial representation of the different erosion processes including risk intensities and frequencies that were validated by the farmers and by in situ observations. Maps of erosion risk confirmed the impact of the concentration of runoff, the high susceptibility of long steep

  2. Characterization of sediment sources, sediment budget estimations, consequences and implications for populations in the Jatún Mayu watershed (Cochabamba, Bolivia)

    Science.gov (United States)

    Vuignier, Jean-Marie; Penna, Ivanna; Jaboyedoff, Michel; Sudmeier-Rieux, Karen

    2015-04-01

    Natural and human-induced erosive processes shape landscape by transferring masses from the mountain to downstream areas. They also impact population both located in the source areas of sediments as well as urban areas settle on the depositional area. Mountain areas in Bolivia present high surface dynamics and high rates of rural migrations, causing e.g. a significant increase of population in Cochabamba city in the last 20 years. This work aims to estimate the sediment production on the Jatún Mayu (Pankuruma) watershed in Cochabamba department taking into account the different origins of sediments. The population of this region is predominantly rural and quechua speaking. The region of study consists in a mountain area situated in the Andes with altitudes ranging from 2500 to 4600m. Field work on July 2014 and high resolution satellite image interpretation (2004 & 2009) allowed us to map and measure landslides and gullies. Almost a hundred of landslides are recorded mostly around the river channel in the middle and the lower part of the valley and provide a moving surface estimated at 3,15km2. Most of the gullies are situated in the upper part of the valley where the vegetation is less abundant on low-sloping agricultural lands. Photogrammetric reconstructions using camera and drone were the main method used to characterise some strategic points along the river in order to get dimensions of landslides, gullies, as well as the riverbed roughness, as the final goal was to model the flooding prone area at the mouth of the watershed, were migrants have been settling for the last years. A total of 9 points of interests along the river bed were surveyed and for each of them a square surface equal to 25m2 was analysed. Approximately 250 pictures by area were needed to estimate roughness along the channel. A flood model has been performed, by using the Riverflo-2D software, to produce a susceptibility map of the downstream region.

  3. The Environmental Protection Agency's Watershed-based Approach: where social and natural sciences meet to address today's water resource challenges

    Science.gov (United States)

    Biddle, J. C.

    2010-12-01

    A growing number of governmental organizations at the local, state, and federal level collaborate with nongovernmental organizations and individuals to solve watershed scale problems (Imperial and Koontz, 2007). Such a shift in policy approach from hierarchical regulation to bottom-up collaboration is largely a result of regulator’s recognition of the interdependence of natural and socio-economic systems on a watershed scale (Steelman and Carmin, 2002. Agencies throughout the federal government increasingly favored new governing institutions that encourage cooperation between local actors with conflicting interests, divergent geographic bases, and overlapping administrative jurisdictions to resolve continuing disputes over resource management (Bardach 1998). This favoritism of collaborative over command-and-control approaches for managing nonpoint source pollution led to the development of watershed partnerships and the watershed-based approach (Lubell et al., 2002). This study aims to further collaborative governance scholarship and aid decision-makers in identifying the critical elements of collaborative governance resulting in environmental improvements. To date, this relationship has not been empirically determined, in spite of the fact that collaborative governance is used routinely by the U.S. Environmental Protection Agency in resolving issues related to watershed management and other applications. This gap in the research is largely due to the lack of longitudinal data. In order to determine whether changes have occurred, environmental data must be collected over relatively long time periods (Koontz and Thomas, 2006; Sabatier, et al., 2005). However, collecting these data is often cost prohibitive. Monitoring water quality is expensive and requires technical expertise, and is often the first line item cut in environmental management budgets. This research is interdisciplinary, looking at the physical, chemical, and biological parameters for 44 waterbodies

  4. Sources and delivery of carbon, nitrogen, and phosphorus to the coastal zone: An overview of global Nutrient Export from Watersheds (NEWS) models and their application

    NARCIS (Netherlands)

    Seitzinger, S.P.; Harrison, J.A.; Dumont, E.L.; Beusen, A.H.W.; Bouwman, A.F.

    2005-01-01

    An overview of the first spatially explicit, multielement (N, P, and C), multiform (dissolved inorganic: DIN, DIP; dissolved organic: DOC, DON, DOP; and particulate: POC, PN, PP) predictive model system of river nutrient export from watersheds (Global Nutrient Export from Watersheds (NEWS)) is prese

  5. Effect of DEM Source and Resolution on Extracting River Network and Watershed within Multi-Lake Area in Tibet

    Science.gov (United States)

    Li, Yang; Li, Gang; Lin, Hui

    2014-11-01

    DEM defines drainage structures and basin through conducting overland flow simulation. Two matured DEM Sources are SRTM DEM (Shuttle Radar Topographic Mission) and ASTER GDEM (Advanced Space borne Thermal Emission and Reflection Radiometer Global Digital Elevation Model); The accuracy of hydrological characters that derived from DEM decreased from high resolution to coarse resolution and appeared to be different in different data source (Vaze,Teng, & Spencer, 2010).

  6. Ecological Engineering Practices for the Reduction of Excess Nitrogen in Human-Influenced Landscapes: A Guide for Watershed Managers

    Science.gov (United States)

    Passeport, Elodie; Vidon, Philippe; Forshay, Kenneth J.; Harris, Lora; Kaushal, Sujay S.; Kellogg, Dorothy Q.; Lazar, Julia; Mayer, Paul; Stander, Emilie K.

    2013-02-01

    Excess nitrogen (N) in freshwater systems, estuaries, and coastal areas has well-documented deleterious effects on ecosystems. Ecological engineering practices (EEPs) may be effective at decreasing nonpoint source N leaching to surface and groundwater. However, few studies have synthesized current knowledge about the functioning principles, performance, and cost of common EEPs used to mitigate N pollution at the watershed scale. Our review describes seven EEPs known to decrease N to help watershed managers select the most effective techniques from among the following approaches: advanced-treatment septic systems, low-impact development (LID) structures, permeable reactive barriers, treatment wetlands, riparian buffers, artificial lakes and reservoirs, and stream restoration. Our results show a broad range of N-removal effectiveness but suggest that all techniques could be optimized for N removal by promoting and sustaining conditions conducive to biological transformations (e.g., denitrification). Generally, N-removal efficiency is particularly affected by hydraulic residence time, organic carbon availability, and establishment of anaerobic conditions. There remains a critical need for systematic empirical studies documenting N-removal efficiency among EEPs and potential environmental and economic tradeoffs associated with the widespread use of these techniques. Under current trajectories of N inputs, land use, and climate change, ecological engineering alone may be insufficient to manage N in many watersheds, suggesting that N-pollution source prevention remains a critical need. Improved understanding of N-removal effectiveness and modeling efforts will be critical in building decision support tools to help guide the selection and application of best EEPs for N management.

  7. Ecological Engineering Practices for the Reduction of Excess Nitrogen in Human-Influenced Landscapes: A Guide for Watershed Managers

    Science.gov (United States)

    Excess nitrogen (N) in freshwater systems, estuaries, and coastal areas has well-documented deleterious effects on ecosystems. Ecological engineering practices (EEPs) may be effective at decreasing nonpoint source N leaching to surface and groundwater. However, few studies have s...

  8. Modeling hydrology, groundwater recharge and non-point nitrate loadings in the Himalayan Upper Yamuna basin

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Kapil K., E-mail: kkn2104@columbia.edu [Columbia Water Center (India Office), Columbia University, New Delhi 110 016 (India); Gosain, A.K. [Department of Civil Engineering, Indian Institute of Technology (IIT) Delhi, Hauz Khas, New Delhi 110 016 (India)

    2013-12-01

    The mountainous Himalayan watersheds are important hydrologic systems responsible for much of the water supply in the Indian sub-continent. These watersheds are increasingly facing anthropogenic and climate-related pressures that impact spatial and temporal distribution of water availability. This study evaluates temporal and spatial distribution of water availability including groundwater recharge and quality (non-point nitrate loadings) for a Himalayan watershed, namely, the Upper Yamuna watershed (part of the Ganga River basin). The watershed has an area of 11 600 km{sup 2} with elevation ranging from 6300 to 600 m above mean sea level. Soil and Water Assessment Tool (SWAT), a physically-based, time-continuous model, has been used to simulate the land phase of the hydrological cycle, to obtain streamflows, groundwater recharge, and nitrate (NO{sub 3}) load distributions in various components of runoff. The hydrological SWAT model is integrated with the MODular finite difference groundwater FLOW model (MODFLOW), and Modular 3-Dimensional Multi-Species Transport model (MT3DMS), to obtain groundwater flow and NO{sub 3} transport. Validation of various modules of this integrated model has been done for sub-basins of the Upper Yamuna watershed. Results on surface runoff and groundwater levels obtained as outputs from simulation show a good comparison with the observed streamflows and groundwater levels (Nash–Sutcliffe and R{sup 2} correlations greater than + 0.7). Nitrate loading obtained after nitrification, denitrification, and NO{sub 3} removal from unsaturated and shallow aquifer zones is combined with groundwater recharge. Results for nitrate modeling in groundwater aquifers are compared with observed NO{sub 3} concentration and are found to be in good agreement. The study further evaluates the sensitivity of water availability to climate change. Simulations have been made with the weather inputs of climate change scenarios of A2, B2, and A1B for end of the

  9. Total nitrogen and suspended-sediment loads and identification of suspended-sediment sources in the Laurel Hill Creek watershed, Somerset County, Pennsylvania, water years 2010-11

    Science.gov (United States)

    Sloto, Ronald A.; Gellis, Allen C.; Galeone, Daniel G.

    2012-01-01

    Laurel Hill Creek is a watershed of 125 square miles located mostly in Somerset County, Pennsylvania, with small areas extending into Fayette and Westmoreland Counties. The upper part of the watershed is on the Pennsylvania Department of Environmental Protection 303(d) list of impaired streams because of siltation, nutrients, and low dissolved oxygen concentrations. The objectives of this study were to (1) estimate the annual sediment load, (2) estimate the annual nitrogen load, and (3) identify the major sources of fine-grained sediment using the sediment-fingerprinting approach. This study by the U.S. Geological Survey (USGS) was done in cooperation with the Somerset County Conservation District. Discharge, suspended-sediment, and nutrient data were collected at two streamflow-gaging stations—Laurel Hill Creek near Bakersville, Pa., (station 03079600) and Laurel Hill Creek at Ursina, Pa., (station 03080000)—and one ungaged stream site, Laurel Hill Creek below Laurel Hill Creek Lake at Trent (station 03079655). Concentrations of nutrients generally were low. Concentrations of ammonia were less than 0.2 milligrams per liter (mg/L), and concentrations of phosphorus were less than 0.3 mg/L. Most concentrations of phosphorus were less than the detection limit of 0.02 mg/L. Most water samples had concentrations of nitrate plus nitrite less than 1.0 mg/L. At the Bakersville station, concentrations of total nitrogen ranged from 0.63 to 1.3 mg/L in base-flow samples and from 0.57 to 1.5 mg/L in storm composite samples. Median concentrations were 0.88 mg/L in base-flow samples and 1.2 mg/L in storm composite samples. At the Ursina station, concentrations of total nitrogen ranged from 0.25 to 0.92 mg/L in base-flow samples; the median concentration was 0.57 mg/L. The estimated total nitrogen load at the Bakersville station was 262 pounds (lb) for 11 months of the 2010 water year (November 2009 to September 2010) and 266 lb for the 2011 water year. Most of the total

  10. Distribution and Ecological Risk Assessment of Heavy Metals in Arable Soils in Bijiang Watershed, China

    Directory of Open Access Journals (Sweden)

    HUANG Wei-heng

    2017-08-01

    Full Text Available It has been paid much attention to soil heavy metal pollution in the Bijiang watershed caused by the Lanping lead-zinc mine. We collected 35 arable soil samples along Bijiang, then sampled and tested the contents of As, Cu, Zn, Cd, Pb, Hg. And then with Nemerow Multi-Factor Index and the Potential Ecological Risk Index method, we evaluated the heavy metal pollution risk. The results showed:(1The accumulation of Pb, Zn, Cd was in a relatively high level, the average was 1 146.97, 579.15, 4.85 mg·kg-1 respectively, which was seriously polluted; the average accumulation of As was 26.85 mg·kg-1; but Cu, Hg was slightly polluted. (2Statistical analysis showed that Lanping area was a main point source pollution of As, Zn, Pb, Cd, while Cu, Hg was pollution caused by different non-point source pollution.(3Within this basin, the Nemerow index was 17.69, which was serious heavy metal pollution, while the comprehensive potential ecological risk index was 773.38, which was a strong potential ecological risk. The contribution of pollutants was Cd > Pb > Zn> As> Hg > Cu. (4As a whole, the soil heavy metal pollution of paddy field was higher than of the dry land.

  11. ASSESSMENT OF FECAL POLLUTION SOURCES IN PLUM CREEK WATERSHED USING PCR AND PHYLOGENETIC ANALYSES OF BACTEROIDETES 16S RDNA

    Science.gov (United States)

    Traditional methods for assessing fecal pollution in environmental systems, such as monitoring for fecal coliforms are not capable of discriminating between different sources fecal pollution. Recently, 16S rDNA Bacteroidetes-targeted PCR assays were developed to discriminate betw...

  12. Demonstration and Effects of Best Management Practices Applied to Control of Rural Non-point Source Pollution in Poyang Lake Area%鄱阳湖区农村面源污染控制中最佳管理措施示范研究

    Institute of Scientific and Technical Information of China (English)

    万金保; 孙蕾; 刘峰; 汤爱萍

    2012-01-01

    Water environment security in rural areas around Poyang Lake has been threatened by increasingly severe non-point source pollution(NPS pollution).Combined with the features of NPS pollution in the areas,the structural best management practices(BMPs) are established in the demonstration area of Xingzi County to control the rural NPS pollution.Monitoring results show that in the monitoring period,the removal amounts of COD,TP and TN by the BMPs are 568.25,3.06 and 26.90 kg,respectively.Constructed wetland maintains the better and more stable pollutant removal capability and the removal amounts of COD,TP and TN per unit area are about 40,0.4 and 3.0 g/m2,respectively.The removal amounts of the pollutants per unit area by ecological ditch vary greatly.Ecological ditch has better removal ability per unit area than constructed wetland,but has poor stability.In consideration of the advantages of ecological ditch and tri-class surface flow constructed wetland(3-SFW),the plants suitable to ecological ditch are recommended to improve its stability in pollutant removal.%鄱阳湖区农村面源污染问题日益严峻,已威胁到湖泊的水环境安全。结合该区域农村面源污染自身的变化特征,在星子县示范区内构建结构性最佳管理措施BMPs(best management practices)系统对区域内农村面源污染进行控制。结果表明,在监测期间该BMPs系统对COD,TP和TN的削减量分别为568.25,3.06和26.90kg。其中人工湿地对COD,TP和TN的单位面积削减量约达40,0.4和3.0g/m2,有较稳定的污染物去除能力;生态沟渠对各污染物单位面积削减量变化较大,与人工湿地相比虽有更强的污染物削减能力,但稳定性较弱。结合生态沟渠和三级表面流人工湿地的特点,建议通过引入适宜的植物至生态沟渠提高其处理污染物的稳定性。

  13. Effects of Grass Hedges and No-tillage Practice Oil the Removing of Typical Agricultural Non-point Source Pollutants from Runoff%免耕和草篱措施对径流中典型农业面源污染物的去除效果

    Institute of Scientific and Technical Information of China (English)

    李霞; 陶梅; 肖波; 王庆海; 陈建平

    2011-01-01

    Chemical fertilizer and herbicide are widely used in agricultural production. These chemical substances not only significantly increase crop yields but also result in serious water pollution. This study was conducted to evaluate the effects of three practices (no-tillage, grass hedges, no-tillage and grass hedges) on the loss of nitrogen, phosphorus and atrazine with runoff. The results showed that no-tillage and grass hedges significantly reduced agricultural non-point source pollution. As compared to the control, the total nitrogen, total phosphorus and atrazine loss in the plots with no-tillage were decreased by 53%, 51% and 56%, respectively; reductions by the grass hedges were 68%, 61% and 90%, respectively; the decreases due to no-tillage and grass hedges were 77%, 76% and 92%, respectively. Moreover, the regression results showed that the losses of nitrogen, phosphorus and atrazine with runoff were positively correlated to the surface runoff. From these results could be concluded that both of no-tillage and grass hedges could significantly reduce nitrogen, phosphorus and atrazine loss with runoff, and the integration of these two practices was proved to be much more effective than their individual effects.%大量施用农业化学物质在提高作物产量的同时,也导致了严重的水体污染.在北京地区不同坡度的径流小区上,通过人工模拟降雨试验,研究免耕、草篱、以及免耕与草篱复合3种措施对农田径流中氮、磷、阿特拉津3种典型农业面源污染物的去除效果.结果表明:免耕措施可减少53%的总氮、51%的总磷和56%的阿特拉津流失;草篱措施可减少68%的总氮、61%的总磷和90%的阿特拉津流失;而免耕与草篱复合措施可减少77%的总氮、76%的总磷和92%的阿特拉津流失.另外,总氯、总磷和阿特拉津流失量均与径流量呈显著的线性正相关关系.本研究证实,免耕和草篱措施均能有效防止氮、磷以及阿特拉津随农

  14. FORESTS: BETWEEN ENERGY DEMAND AND ECOSYSTEM SERVICES. AN EMERGY ASSESSMENT OF FORESTRY STOCKS AS THE MAIN SOURCE OF THERMAL FUEL IN THE MARA RIVER WATERSHED, MARAMUREȘ COUNTY, ROMANIA

    Directory of Open Access Journals (Sweden)

    Silviu BUMBAK

    2016-09-01

    Full Text Available Nature builds resilience through storages of energy and one of the most iconic elements encompassing this capacity is represented by forests. Biomass in general and forests in particular are known to be one of the vast global reservoirs of carbon and energy and are described as forms of renewable natural capital that managed until the second half of the ninetieth century to globally sustain human communities as the major source of energy. Forests actively contribute to the functionality of a territorial system through a series of attributes such as water retention capacity, soil and slope stability, primary production capacity, all termed ecosystem services, benefits that communities take for granted. In more remote rural areas around the world, such as the Carpathian Mara River watershed, local communities still rely on forestry wood as the main supplier of thermal energy. The dependency relation also represents the community’s level of perception towards natural resources, the landmarks and image of the entire Land of Maramureș as „the wood civilisation”, for example, being a cultural construct build through this energetic resource. In a time of pressure over energetic resources and following the premises of Emergy Theory and methodology, in this paper we propose an alternative approach in assessing natural resources in order to better understand that the exploitable energetic value of forests comes second when compared with the value of the provided ecosystem services.

  15. The non-point output of different agriculture landuse types in Zhexi hydraulic region of Taihu Basin

    Institute of Scientific and Technical Information of China (English)

    LIHengpeng; LIUXiaomei; HUANGWenyu

    2004-01-01

    This paper takes Zhexi hydraulic region in Taihu Basin as a study area. On the basis of hydraulic analysis function of Arcgis8.3, the drainages were delineated by selecting the monitoring points and discharge stations as outlets. The landuse map were finished by denoting the TM/ETM image. The precipitation map was finished by spatial interpolation according to the rainfall monitoring records. Overlaying the drainage boundary, landuse map and precipitation map, the rainfall, different landuse type area, and runoff pollution concentration and runoff were calculated. Based on these data in different sub-watersheds, by Origin7.0 regression tool, an equation is established to predict runoff using the relationships between runoff, precipitation depth and land use patterns in each of the sub-watersheds. Selecting the sub-watershed which is mainly composed of forest landuse type, the mean runoff concentration (MRC) from sub-watershed has been estimated. The mean runoff concentration of farmland has been estimated by the same methods after the contribution of forestlanduse type was removed. The results are" for the forest landuse type, the mean runoff concentrationsof COD, BOD, Total N and Total P are 2.95 mg/l, 1.080 mg/l, 0.715 mg/l, and 0.039 mg/l,respectively; for the farmland, the mean runoff concentrations of COD, BOD, Total N and Total P are 5.721 rag/l, 3.097 rag/l, 2.092 rag/l, and 0.166 rag/l, respectively. By using these results, the agriculture non-point pollution loads have been assessed. The loads of COD, BOD, Total N and Total P in Zhexi region are 14,631.69 t/a, 6401.93 t/a, 4281.753 t/a and 287.67 t/a, respectively.

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

    Science.gov (United States)

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

    2004-01-01

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

  17. Streamflow and water-quality conditions including geologic sources and processes affecting selenium loading in the Toll Gate Creek watershed, Aurora, Arapahoe County, Colorado, 2007

    Science.gov (United States)

    Paschke, Suzanne S.; Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.; Schaffrath, Keelin R.

    2013-01-01

    Toll Gate Creek is a perennial stream draining a suburban area in Aurora, Colorado, where selenium concentrations have consistently exceeded the State of Colorado aquatic-life standard for selenium of 4.6 micrograms per liter since the early 2000s. In cooperation with the City of Aurora, Colorado, Utilities Department, a synoptic water-quality study was performed along an 18-kilometer reach of Toll Gate Creek extending from downstream from Quincy Reservoir to the confluence with Sand Creek to develop a detailed understanding of streamflow and concentrations and loads of selenium in Toll Gate Creek. Streamflow and surface-water quality were characterized for summer low-flow conditions (July–August 2007) using four spatially overlapping synoptic-sampling subreaches. Mass-balance methods were applied to the synoptic-sampling and tracer-injection results to estimate streamflow and develop spatial profiles of concentration and load for selenium and other chemical constituents in Toll Gate Creek surface water. Concurrent groundwater sampling determined concentrations of selenium and other chemical constituents in groundwater in areas surrounding the Toll Gate Creek study reaches. Multivariate principal-component analysis was used to group samples and to suggest common sources for dissolved selenium and major ions. Hydrogen and oxygen stable-isotope ratios, groundwater-age interpretations, and chemical analysis of water-soluble paste extractions from core samples are presented, and interpretation of the hydrologic and geochemical data support conclusions regarding geologic sources of selenium and the processes affecting selenium loading in the Toll Gate Creek watershed.

  18. Chemical and U-Sr isotopic variations in stream and source waters of the Strengbach watershed (Vosges mountains, France)

    Science.gov (United States)

    Pierret, M. C.; Stille, P.; Prunier, J.; Viville, D.; Chabaux, F.

    2014-10-01

    This is the first comprehensive study dealing with major and trace element data as well as 87Sr/86Sr isotope and (234U/238U) activity ratios (AR) determined on the totality of springs and brooks of the Strengbach catchment. It shows that the small and more or less monolithic catchment drains different sources and streamlets with very different isotopic and geochemical signatures. Different parameters control the diversity of the source characteristics. Of importance is especially the hydrothermal overprint of the granitic bedrock, which was stronger for the granite from the northern slope; also significant are the different meteoric alteration processes of the bedrock causing the formation of 0.5 to 9 m thick saprolite and above the formation of an up to 1m thick soil system. These processes mainly account for springs and brooks from the northern slope having higher Ca / Na, Mg / Na, and Sr / Na ratios, but lower 87Sr/86Sr isotopic ratios than those from the southern slope. The chemical compositions of the source waters in the Strengbach catchment are only to a small extent the result of alteration of primary bedrock minerals, and rather reflect dissolution/precipitation processes of secondary mineral phases like clay minerals. The (234U/238U) AR, however, are decoupled from the 87Sr/86Sr isotope system, and reflect to some extent the level of altitude of the source and, thus, the degree of alteration of the bedrock. The sources emerging at high altitudes have circulated through already weathered materials (saprolite and fractured bedrock depleted in 234U), implying (234U/238U) AR below 1, which is uncommon for surface waters. Preferential flow paths along constant fractures in the bedrocks might explain the - over time - homogeneous U AR of the different spring waters. However, the geochemical and isotopic variations of stream waters at the outlet of the catchment are controlled by variable contributions of different springs, depending on the hydrological

  19. Glacial erosion dynamics in a small mountainous watershed (Southern French Alps): A source-to-sink approach

    Science.gov (United States)

    Bonneau, Lucile; Toucanne, Samuel; Bayon, Germain; Jorry, Stéphan J.; Emmanuel, Laurent; Silva Jacinto, Ricardo

    2017-01-01

    In this study we used major element composition, neodymium isotopes ratios (εNd) and concentration of REE to track and quantify the sediment routing in the Var sedimentary system from source (Southern French Alps) to sink (Ligurian Sea) over the last 50 ka. Our data reveal that changes in sediment sources over that period, associated with concomitant changes in the hyperpycnal (i.e. flood-generated turbidity currents) activity in the Var submarine canyon, were mainly driven by paleoenvironmental conditions in the upper basin and in particular by the presence of glaciers during the last glacial period. Based on this evidence, we determined when and how glacier-derived sediments were produced, then excavated and transferred to the ocean, allowing us to ultimately tune offshore sedimentary records to onshore denudation rates. In contrast to large glaciated systems, we found that sediment export from the Var River to the Mediterranean Sea directly responded to climate-induced perturbations within the basin. Finally, we estimated that sediment fluxes in the Var routing system were 2.5 times higher during the Last Glacial Maximum than today, thus confirming that glacier denudation rates exceed fluvial rates and that such a pattern also governs the interglacial-glacial sediment flux cycle in other small mountainous basins.

  20. Large shift in source of fine sediment in the upper Mississippi River

    Science.gov (United States)

    Belmont, P.; Gran, K.B.; Schottler, S.P.; Wilcock, P.R.; Day, S.S.; Jennings, C.; Lauer, J.W.; Viparelli, E.; Willenbring, J.K.; Engstrom, D.R.; Parker, G.

    2011-01-01

    Although sediment is a natural constituent of rivers, excess loading to rivers and streams is a leading cause of impairment and biodiversity loss. Remedial actions require identification of the sources and mechanisms of sediment supply. This task is complicated by the scale and complexity of large watersheds as well as changes in climate and land use that alter the drivers of sediment supply. Previous studies in Lake Pepin, a natural lake on the Mississippi River, indicate that sediment supply to the lake has increased 10-fold over the past 150 years. Herein we combine geochemical fingerprinting and a suite of geomorphic change detection techniques with a sediment mass balance for a tributary watershed to demonstrate that, although the sediment loading remains very large, the dominant source of sediment has shifted from agricultural soil erosion to accelerated erosion of stream banks and bluffs, driven by increased river discharge. Such hydrologic amplification of natural erosion processes calls for a new approach to watershed sediment modeling that explicitly accounts for channel and floodplain dynamics that amplify or dampen landscape processes. Further, this finding illustrates a new challenge in remediating nonpoint sediment pollution and indicates that management efforts must expand from soil erosion to factors contributing to increased water runoff. ?? 2011 American Chemical Society.

  1. Identifying nitrate sources and transformations in surface water by combining dual isotopes of nitrate and stable isotope mixing model in a watershed with different land uses and multi-tributaries

    Science.gov (United States)

    Wang, Meng; Lu, Baohong

    2017-04-01

    Nitrate is essential for the growth and survival of plants, animals and humans. However, excess nitrate in drinking water is regarded as a health hazard as it is linked to infant methemoglobinemia and esophageal cancer. Revealing nitrate characteristics and identifying its sources are fundamental for making effective water management strategies, but nitrate sources in multi-tributaries and mixed land covered watersheds remain unclear. It is difficult to determine the predominant NO3- sources using conventional water quality monitoring techniques. In our study, based on 20 surface water sampling sites for more than two years' monitoring