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Sample records for agricultural nonpoint sources

  1. AGRICULTURAL NONPOINT SOURCE POLLUTION (AGNPS)

    EPA Science Inventory

    Developed by the USDA Agricultural Research Service, Agricultural Nonpoint Source Pollution (AGNPS) model addresses concerns related to the potential impacts of point and nonpoint source pollution on surface and groundwater quality (Young et al., 1989). It was designed to quantit...

  2. Control of Agricultural Nonpoint Source Pollution by Natural Wetland Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduction of nonpoint source pollutants, principally sediment and nutrients moving from cultivated fields to surface waters, is a major challenge. Remnants of once-extensive natural wetlands occur across the agricultural landscape, and some workers have suggested that these areas might be managed t...

  3. ALTERNATIVE POLICIES FOR CONTROLLING NONPOINT AGRICULTURAL SOURCES OF WATER POLLUTION

    EPA Science Inventory

    This study of policies for controlling water pollution from nonpoint agricultural sources includes a survey of existing state and Federal programs, agencies, and laws directed to the control of soil erosion. Six policies representing a variety of approaches to this pollution prob...

  4. Nonpoint Sources.

    ERIC Educational Resources Information Center

    Browne, F. X.

    1978-01-01

    Presented a literature review of nonpoint source effects on water quality and pollution covering: (1) water quality effects; (2) watershed studies; (3) nonpoint source models; and nonpoint source controls. A list of 122 references published in 1976 and 1977 is also presented. (HM)

  5. Nonpoint sources

    SciTech Connect

    Selzer, L.

    1994-12-31

    Nonpoint source pollution remains the most pervasive water quality issue faced today. Unlike pollution from point sources, nonpoint source pollution is diffuse both in terms of its origin and the manner in which it enters ground and surface waters. It results from a great variety of human activities that take place over a wide geographic area perhaps many hundreds or even thousands of acres. And unlike pollutants from point sources--which enter the environment at well-defined locations and in relatively even, continuous discharges--pollutants from nonpoint sources usually find their way into surface and ground waters in sudden surges associated with rainfall, thunderstorms, or snowmelt. The author discusses some of the most significant sources of nonpoint source pollution.

  6. OPTIMAL MANAGEMENT OF NON-POINT SOURCE POLLUTION FROM AGRICULTURE: AN APPLICATION OF DYNAMIC PROGRAMMING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural non-point source pollution is a major source of water quality impairment. When considering responses to non-point source pollution, several policy options have been considered historically, including reducing inputs (e.g. fertilizers) altering technologies on the landscape (e.g. conserv...

  7. Nonpoint Source Pollution.

    PubMed

    Ahmad, Zaki Uddin; Sakib, Salman; Gang, Daniel Dianchen

    2016-10-01

    Research advances on non-point source pollution in the year 2015 have been depicted in this review paper. Nonpoint source pollution is mainly caused by agricultural runoff, urban stormwater, and atmospheric deposition. Modeling techniques of NPS with different tools are reviewed in this article. PMID:27620104

  8. Management of agricultural nonpoint source pollution in China: current status and challenges.

    PubMed

    Wang, Xiaoyan

    2006-01-01

    Water quality in China shows an overall trend of deterioration in recent years. Nonpoint source pollution from agricultural and rural regions is the leading source of water pollution. The agricultural nonpoint source pollutants are mainly from fertilization of cropland, excessive livestock and poultry breeding and undefined disposal of daily living wastes in rural areas. Agricultural nonpoint sources contribute the main source of pollution to most watersheds in China, but they are ignored in management strategy and policy. Due to the lack of full understanding of water pollution control and management and the lack of perfect water quality standard systems and practical legislative regulations, agricultural nonpoint source pollution will become one of the biggest challenges to the sustainable development of rural areas and to society as a whole. The system for agricultural nonpoint source pollution control in China should include an appropriate legislation and policy framework, financing mechanisms, monitoring system, and technical guidelines and standards. The management of agricultural nonpoint source pollution requires multidisciplinary approaches that will involve a range of government departments, institutions and the public. PMID:16594318

  9. Feasibility of point-nonpoint source trading for managing agricultural pollutant loadings to coastal waters

    NASA Astrophysics Data System (ADS)

    Crutchfield, Stephen R.; Letson, David; Malik, Arun S.

    1994-10-01

    A recent focus of water quality policy discussions has been the trading of pollution abatement between point and nonpoint sources. Point-nonpoint trading would allow point sources to sponsor nonpoint source controls rather than install further controls of their own. If nonpoint source loadings are significant and the marginal costs of their control are lower than for additional point source controls, water quality goals could be met at lower cost with trading. We isolate difficulties particular to incentive policies such as point-nonpoint trading and then screen coastal watersheds for those satisfying conditions that play a major role in determining whether trading can improve water quality. We follow the recent Coastal Zone Act Reauthorization Amendments in emphasizing agriculture, the single largest cause of nonpoint source pollution. Our screening analysis provides an initial, empirical assessment of the feasibility of trading for managing agricultural land use to protect coastal water quality. We also illustrate the additional analysis required to quantify the potential for successful trading in those watersheds which meet our screening criteria.

  10. ASSESSMENT OF RISK REDUCTION STRATEGIES FOR THE MANAGEMENT OF AGRICULTURAL NONPOINT SOURCE PESTICIDE RUNOFF IN ESTUARINE ECOSYSTEMS

    EPA Science Inventory

    Agricultural nonpoint source (NPS) runoff may result in significant discharges of pesticides, suspended sediments, and fertilizers into estuarine habitats adjacent to agricultural areas or downstream from agricultural watersheds. Exposure of estuarine fin fish and shellfish to to...

  11. A MODELING-GIS APPROACH FOR THE ASSESSMENT OF SOIL AND GROUND WATER VULNERABILITY TO NONPOINT SOURCE IN AGRICULTURAL WATERSHEDS

    EPA Science Inventory

    Ground water pollution due to agriculture activities is a major source of concern. Vast agricultural lands constitute a nonpoint source for pollutants, such as pesticides and nitrogen fertilizers, which threatens ground water resources and the integrity of aquatic and terrestria...

  12. Agroforestry buffers for nonpoint source pollution reductions from agricultural watersheds.

    PubMed

    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. PMID:21546665

  13. Nonpoint Source Pollution: Agriculture, Forestry, and Mining. Instructor Guide. Working for Clean Water: An Information Program for Advisory Groups.

    ERIC Educational Resources Information Center

    Buskirk, E. Drannon, Jr.

    Nonpoint sources of pollution have diffuse origins and are major contributors to water quality problems in both urban and rural areas. Addressed in this instructor's manual are the identification, assessment, and management of nonpoint source pollutants resulting from mining, agriculture, and forestry. The unit, part of the Working for Clean Water…

  14. Landscape Planning for Agricultural Nonpoint Source Pollution Reduction I: A Geographical Allocation Framework

    NASA Astrophysics Data System (ADS)

    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.

  15. Modeling Agricultural Nonpoint Source Pollution Using a Geographic Information System Approach

    NASA Astrophysics Data System (ADS)

    Emili, Lisa A.; Greene, Richard P.

    2013-01-01

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

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

    USGS Publications Warehouse

    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.)

  17. Impacts of input parameter spatial aggregation on an agricultural nonpoint source pollution model

    NASA Astrophysics Data System (ADS)

    FitzHugh, T. W.; Mackay, D. S.

    2000-09-01

    The accuracy of agricultural nonpoint source pollution models depends in part on how well model input parameters describe the relevant characteristics of the watershed. The spatial extent of input parameter aggregation has previously been shown to have a substantial impact on model output. This study investigates this problem using the Soil and Water Assessment Tool (SWAT), a distributed-parameter agricultural nonpoint source pollution model. The primary question addressed here is: how does the size or number of subwatersheds used to partition the watershed affect model output, and what are the processes responsible for model behavior? SWAT was run on the Pheasant Branch watershed in Dane County, WI, using eight watershed delineations, each with a different number of subwatersheds. Model runs were conducted for the period 1990-1996. Streamflow and outlet sediment predictions were not seriously affected by changes in subwatershed size. The lack of change in outlet sediment is due to the transport-limited nature of the Pheasant Branch watershed and the stable transport capacity of the lower part of the channel network. This research identifies the importance of channel parameters in determining the behavior of SWAT's outlet sediment predictions. Sediment generation estimates do change substantially, dropping by 44% between the coarsest and the finest watershed delineations. This change is primarily due to the sensitivity of the runoff term in the Modified Universal Soil Loss Equation to the area of hydrologic response units (HRUs). This sensitivity likely occurs because SWAT was implemented in this study with a very detailed set of HRUs. In order to provide some insight on the scaling behavior of the model two indexes were derived using the mathematics of the model. The indexes predicted SWAT scaling behavior from the data inputs without a need for running the model. Such indexes could be useful for model users by providing a direct way to evaluate alternative models

  18. Evaluating agricultural nonpoint-source pollution programs in two Lake Erie tributaries.

    PubMed

    Forster, D Lynn; Rausch, Jonathan N

    2002-01-01

    During the past three decades, numerous government programs have encouraged Lake Erie basin farmers to adopt practices that reduce water pollution. The first section of this paper summarizes these state and federal government agricultural pollution abatement programs in watersheds of two prominent Lake Erie tributaries, the Maumee River and Sandusky River. Expenditures are summarized for each program, total expenditures in each county are estimated, and cost effectiveness of program expenditures (i.e., cost per metric ton of soil saved) are analyzed. Farmers received nearly $143 million as incentive payments to implement agricultural nonpoint source pollution abatement programs in the Maumee and Sandusky River watersheds from 1987 to 1997. About 95% of these funds was from federal sources. On average, these payments totaled about $7000 per farm or about $30 per farm acre (annualized equivalent of $2 per acre) within the watersheds. Our analysis raises questions about how efficiently these incentive payments were allocated. The majority of Agricultural Conservation Program (ACP) funds appear to have been spent on less cost-effective practices. Also, geographic areas with relatively low (high) soil erosion rates received relatively large (small) funding. PMID:11837427

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

    NASA Astrophysics Data System (ADS)

    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

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

    USGS Publications Warehouse

    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 (< 0.1-12 ??g/L), nitrate (0.1 to 15 mg/L, and chloride (1.5 to 26 mg/L) in water were similar for creek and tile samples. Water draining predominantly agricultural row crop areas had much higher concentrations than water draining 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

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    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.

  3. Nonpoint-Source Agricultural Hazard Index: A Case Study of the Province of Cremona, Italy

    NASA Astrophysics Data System (ADS)

    Trevisan, Marco; Padovani, Laura; Capri, Ettore

    2000-11-01

    This paper reports the results of a study aimed at the evaluation of the hazard level of farming activities in the province of Cremona, Italy, with particular reference to groundwater. The applied methodology employs a parametric approach based on the definition of potential hazard indexes (nonpoint-source agricultural hazard indexes, NPSAHI). Two categories of parameters were considered: the hazard factors (HF), which represent all farming activities that cause or might cause an impact on groundwater (use of fertilizers and pesticides, application of livestock and poultry manure, food industry wastewater, and urban sludge), and the control factors (CF), which adapt the hazard factor to the characteristics of the site (geographical location, slope, agronomic practices, and type of irrigation). The hazard index (HI) can be calculated multiplying the hazard factors by the control factors and, finally, the NPSAHI are obtained dividing HI into classes on a percentile basis using a scale ranging from 1 to 10. Organization, processing, and display of all data layers were performed using the geographical information system (GIS) ArcView and its Spatial Analyst extension. Results show that the potential hazard of groundwater pollution by farming activities in the province of Cremona falls mainly in the fifth class (very low hazard).

  4. Suspended particulates and bioaerosols emitted from an agricultural non-point source.

    PubMed

    Hameed, A A; Khodr, M I

    2001-02-01

    Suspended particulate and bioaerosol levels were measured at three sites downwind of an agricultural non-point source during the wheat harvesting season. Suspended particulates were detected at mean values ranging from 10000 to 2420 micrograms m-3 at distances of from 20 to 60 m downwind of the source, respectively. Airborne viable bacterial counts were recorded at mean values ranging between 10(4) and 10(6) colony forming units (cfu) m-3, whereas, Gram negative (Gram -ve) bacteria varied between 10(3) and 10(5) cfu m-3. Fungi levels were detected at mean values varying between 10(5) and 10(6) cfu m-3. However, streptomycetes were found at lower counts than those recorded for viable bacteria and fungi. Total viable bacteria, Gram -ve bacteria, fungi and streptomycetes associated hay fragments were determined at mean values of 1.5 x 10(6), 1.6 x 10(3), 2.2 x 10(4) and 6 x 10(3) cfu g-1 of hay, respectively. Cladosporium, white and red yeasts as well as Alternaria were the predominant airborne fungi, whereas, Alternaria was the dominant species associated with hay fragments. Pseudomonas, Acinetobacter and Enterobacteriaceae were the dominant Gram -ve bacteria. The most common fungal genera, such as Cladosporium and Fusarium (minor short axis), as well as Streptomyces species have an aerodynamic diameter (dae) of less than 5 microns, which can penetrate and deposit in the alveoli. Farmers and nearby residents are exposed to high levels of organic dust and bioaerosols during the wheat harvesting season. This may cause health problems in exposed persons based on toxic or allergic reactions. PMID:11354730

  5. NON-POINT SOURCE POLLUTION

    EPA Science Inventory

    Non-point source pollution is a diffuse source that is difficult to measure and is highly variable due to different rain patterns and other climatic conditions. In many areas, however, non-point source pollution is the greatest source of water quality degradation. Presently, stat...

  6. Application of the Soil and Water Assessment Tool and Annualized Agricultural Non-Point Source Models in the St. Joseph River Watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the performance of two water quality models in accordance to specific tasks designated in the USDA Agricultural Research Service Conservation Effects Assessment Project. The Soil and Water Assessment Tool (SWAT) and the Annualized Agricultural Non-Point Source (AnnAGNPS) models ...

  7. Predicting the impacts of climate change on nonpoint source pollutant loads from agricultural small watershed using artificial neural network.

    PubMed

    Lee, Eunjeong; Seong, Chounghyun; Hakkwan, Kim; Park, Seungwoo; Kang, Moonseong

    2010-01-01

    This study described the development and validation of an artificial neural network (ANN) for the purpose of analyzing the effects of climate change on nonpoint source (NPS) pollutant loads from agricultural small watershed. The runoff discharge was estimated using ANN algorithm. The performance of ANN modelwas examined using observed data from s tudy watershed. The simulationresults agreed well with observed values during calibration and validation periods. NPS pollutant loads were calculated from load-discharge relationship driven by long-term monitoring data. LARS-WG (Long Ashton Research Station-Weather Generator) model was used to generate rainfall data. The calibrated ANN model and load-discharge relationship with the generated data from LARS-WGwere applied to analyze the effects of climate change on NPS pollutant loads from the agricultural small watershed. The results showed that the ANN model provided valuable approach i n estimating future runof f discharge, and the NPS pollutantloads. PMID:20923094

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

    PubMed

    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. PMID:26392092

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Landscape Planning for Agricultural Non-Point Source Pollution Reduction. II. Balancing Watershed Size, Number of Watersheds, and Implementation Effort

    NASA Astrophysics Data System (ADS)

    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 km2; and optimal expenditure ranged from 21,000 to 35,000/km2. 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 km2. These watersheds are designed to serve as implementation units for a targeted NPS pollution control program currently being developed in Wisconsin.

  11. PROBABILISTIC ASSESSMENT OF GROUNDWATER VULNERABILITY TO NONPOINT SOURCE POLLUTION IN AGRICULTURAL WATERSHEDS

    EPA Science Inventory

    This paper presents a probabilistic framework for the assessment of groundwater pollution potential by pesticides in two adjacent agricultural watersheds in the Mid-Altantic Coastal Plain. Indices for estimating streams vulnerability to pollutants' load from the surficial aquifer...

  12. FILTRATION OF AGRICULTURAL NON-POINT SOURCE PHOSPHORUS POLLUTION WITH INDUSTRIAL MATERIALS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Loss of phosphorus (P) from agricultural lands to water bodies is an environmental concern. Ditch drainage from lands with heavy poultry manure application on the Eastern Shore of the Chesapeake Bay provides a pathway to deliver dissolved P to the bay. Best management practices designed to reduce ...

  13. Comparison of Measured to Predicted Estimations of Nonpoint Source Contaminants Using Conservation Practices in an Agriculturally-Dominated Watershed in Northeast Arkansas, USA.

    PubMed

    Frasher, Sarah K; Woodruff, Tracy M; Bouldin, Jennifer L

    2016-06-01

    In efforts to reduce nonpoint source runoff and improve water quality, Best Management Practices (BMPs) were implemented in the Outlet Larkin Creek Watershed. Farmers need to make scientifically informed decisions concerning BMPs addressing contaminants from agricultural fields. The BMP Tool was developed from previous studies to estimate BMP effectiveness at reducing nonpoint source contaminants. The purpose of this study was to compare the measured percent reduction of dissolved phosphorus (DP) and total suspended solids to the reported percent reductions from the BMP Tool for validation. Similarities were measured between the BMP Tool and the measured water quality parameters. Construction of a sedimentation pond resulted in 74 %-76 % reduction in DP as compared to 80 % as predicted with the BMP Tool. However, further research is needed to validate the tool for additional water quality parameters. The BMP Tool is recommended for future BMP implementation as a useful predictor for farmers. PMID:27194420

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

    PubMed

    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. PMID:21229773

  15. Nonpoint-source agricultural chemicals in ground water in Nebraska; preliminary results for six areas of the High Plains Aquifer

    USGS Publications Warehouse

    Chen, Hsiu-Hsiung; Druliner, A.D.

    1987-01-01

    The reconnaissance phase of a study to determine the occurrence of agricultural chemicals from nonpoint sources in groundwater in six areas, which represented the major provinces of the High Plains aquifer in Nebraska is described. In 1984, water from 82 wells in the 6 study areas was analyzed for nitrate, and water from 57 of the 82 wells was analyzed for triazine herbicides. Data for 9 of the 21 independent variables suspected of affecting concentrations of nitrate and triazine herbicides in groundwater were compiled from the 82 well sites. The variables and their ranges are: hydraulic gradient (XI), 0.006-0.0053; hydraulic conductivity (X2), 5-149 ft/day; specific discharge (X3), 0.0128-0.2998 ft/day; depth to water (X4), 3-239 ft; well depth (X5), 40-550 ft; annual precipitation (X6), 12.0-39.3 inches; soil permeability (X7), 0.76-9.0 inches; irrigation well density (X8), 0-8 irrigation wells/ sq mi; and annual nitrogen fertilizer use (X9), 0-260 lbs of nitrogen/acre. Nitrate concentrations ranged from < 0.1 to 45 mg/L as nitrogen. Triazine herbicide concentrations were detected in samples from five of the six study areas in concentrations ranging from < 0.1 to 2.3 mg/L. Statistical tests indicated that there were significant differences in nitrate concentrations among the six study areas, while no significant differences in triazine herbicide concentrations were found. Concentrations of nitrate and triazine herbicide were significantly larger in more intensively irrigated areas. Preliminary correlations with the independent variables and nitrate concentrations indicated significant relations at the 95% confidence level with variables X2, X5, and X8. Correlations with triazine herbicide concentrations indicated significant relations with variables X2 , X3, X5, X6, and X8, and with nitrate concentrations (X10). By using a simple multiple regression technique, variables X5, X8, and X9 explained about 51% of the variation in nitrate concentrations. Variables X3

  16. A simulation-based interval two-stage stochastic model for agricultural non-point source pollution control through land retirement.

    PubMed

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

    2006-05-15

    This study presents a simulation-based interval two-stage stochastic programming (SITSP) model for agricultural non-point source (NPS) pollution control through land retirement under uncertain conditions. The modeling framework was established by the development of an interval two-stage stochastic program, with its random parameters being provided by the statistical analysis of the simulation outcomes of a distributed water quality approach. The developed model can deal with the tradeoff between agricultural revenue and "off-site" water quality concern under random effluent discharge for a land retirement scheme through minimizing the expected value of long-term total economic and environmental cost. In addition, the uncertainties presented as interval numbers in the agriculture-water system can be effectively quantified with the interval programming. By subdividing the whole agricultural watershed into different zones, the most pollution-related sensitive cropland can be identified and an optimal land retirement scheme can be obtained through the modeling approach. The developed method was applied to the Swift Current Creek watershed in Canada for soil erosion control through land retirement. The Hydrological Simulation Program-FORTRAN (HSPF) was used to simulate the sediment information for this case study. Obtained results indicate that the total economic and environmental cost of the entire agriculture-water system can be limited within an interval value for the optimal land retirement schemes. Meanwhile, a best and worst land retirement scheme was obtained for the study watershed under various uncertainties. PMID:16242757

  17. Tracking nonpoint source nitrogen pollution in human-impacted watersheds

    USGS Publications Warehouse

    Kaushal, S.S.; Groffman, P.M.; Band, L.E.; Elliott, E.M.; Shields, C.A.; Kendall, C.

    2011-01-01

    Nonpoint source nitrogen (N) pollution is a leading contributor to U.S. water quality impairments. We combined watershed N mass balances and stable isotopes to investigate fate and transport of nonpoint N in forest, agricultural, and urbanized watersheds at the Baltimore Long-Term Ecological Research site. Annual N retention was 55%, 68%, and 82% for agricultural, suburban, and forest watersheds, respectively. Analysis of ?? 15N-NO3-, and ??18O-NO 3- indicated wastewater was an important nitrate source in urbanized streams during baseflow. Negative correlations between ??15N-NO3- and ??18O- NO3- in urban watersheds indicated mixing between atmospheric deposition and wastewater, and N source contributions changed with storm magnitude (atmospheric sources contributed ???50% at peak storm N loads). Positive correlations between ??15N-NO3- and ??18O-NO3- in watersheds suggested denitrification was removing septic system and agriculturally derived N, but N from belowground leaking sewers was less susceptible to denitrification. N transformations were also observed in a storm drain (no natural drainage network) potentially due to organic carbon inputs. Overall, nonpoint sources such as atmospheric deposition, wastewater, and fertilizer showed different susceptibility to watershed N export. There were large changes in nitrate sources as a function of runoff, and anticipating source changes in response to climate and storms will be critical for managing nonpoint N pollution. ?? 2011 American Chemical Society.

  18. Spatial and temporal variations in non-point source losses of nitrogen and phosphorus in a small agricultural catchment in the Three Gorges Region.

    PubMed

    Chen, Chenglong; Gao, Ming; Xie, Deti; Ni, Jiupai

    2016-04-01

    Losses of agricultural pollutants from small catchments are a major issue for water quality in the Three Gorges Region. Solutions are urgently needed. However, before pollutant losses can be controlled, information about spatial and temporal variations in pollutant losses is needed. The study was carried out in the Wangjiagou catchment, a small agricultural catchment in Fuling District, Chongqing, and the data about non-point source losses of nitrogen and phosphorus was collected here. Water samples were collected daily by an automatic water sampler at the outlets of two subcatchments from 2012 to 2014. Also, samples of surface runoff from 28 sampling sites distributed through the subcatchments were collected during 12 rainfall events in 2014. A range of water quality variables were analyzed for all samples and were used to demonstrate the variation in non-point losses of nitrogen and phosphorus over a range of temporal and spatial scales and in different types of rainfall in the catchment. Results showed that there was a significant linear correlation between the mass concentrations of total nitrogen (TN) and nitrate (NO3-N) in surface runoff and that the relationship was maintained with changes in time. Concentrations of TN and NO3-N peaked after fertilizer was applied to crops in spring and autumn; concentrations decreased rapidly after the peak values in spring but declined slowly in autumn. N and P concentrations fluctuated more and showed a greater degree of dispersion during the spring crop cultivation period than those in autumn. Concentrations of TN and NO3-N in surface runoff were significantly and positively correlated with the proportion of the area that was planted with corn and mustard tubers, but were negatively correlated with the proportion of the area taken up with rice and mulberry plantations. The average concentrations of TN and NO3-N in surface runoff reached the highest level from the sampling points at the bottom of the land used for corn

  19. Spatial and temporal variations in non-point source losses of nitrogen and phosphorus in a small agricultural catchment in the Three Gorges Region.

    PubMed

    Chen, Chenglong; Gao, Ming; Xie, Deti; Ni, Jiupai

    2016-04-01

    Losses of agricultural pollutants from small catchments are a major issue for water quality in the Three Gorges Region. Solutions are urgently needed. However, before pollutant losses can be controlled, information about spatial and temporal variations in pollutant losses is needed. The study was carried out in the Wangjiagou catchment, a small agricultural catchment in Fuling District, Chongqing, and the data about non-point source losses of nitrogen and phosphorus was collected here. Water samples were collected daily by an automatic water sampler at the outlets of two subcatchments from 2012 to 2014. Also, samples of surface runoff from 28 sampling sites distributed through the subcatchments were collected during 12 rainfall events in 2014. A range of water quality variables were analyzed for all samples and were used to demonstrate the variation in non-point losses of nitrogen and phosphorus over a range of temporal and spatial scales and in different types of rainfall in the catchment. Results showed that there was a significant linear correlation between the mass concentrations of total nitrogen (TN) and nitrate (NO3-N) in surface runoff and that the relationship was maintained with changes in time. Concentrations of TN and NO3-N peaked after fertilizer was applied to crops in spring and autumn; concentrations decreased rapidly after the peak values in spring but declined slowly in autumn. N and P concentrations fluctuated more and showed a greater degree of dispersion during the spring crop cultivation period than those in autumn. Concentrations of TN and NO3-N in surface runoff were significantly and positively correlated with the proportion of the area that was planted with corn and mustard tubers, but were negatively correlated with the proportion of the area taken up with rice and mulberry plantations. The average concentrations of TN and NO3-N in surface runoff reached the highest level from the sampling points at the bottom of the land used for corn

  20. NONPOINT SOURCE MODEL CALIBRATION IN HONEY CREEK WATERSHED

    EPA Science Inventory

    The U.S. EPA Non-Point Source Model has been applied and calibrated to a fairly large (187 sq. mi.) agricultural watershed in the Lake Erie Drainage basin of north central Ohio. Hydrologic and chemical routing algorithms have been developed. The model is evaluated for suitability...

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

    PubMed

    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. PMID:27441855

  2. Designing Schemes to Mitigate Non-Point Source Water Pollution from Agriculture: The Value of High-Resolution Hydrochemical and Hydrophysical Data

    NASA Astrophysics Data System (ADS)

    Barber, N.; Reaney, S. M.

    2014-12-01

    To effectively mitigate non-point source water pollution from agriculture, first it is vital to have an awareness of a watershed's hydrological and contaminant regime. Understanding the magnitude and timing of pollutant export, as well as the pathways by which different constituents are delivered to a water course, is paramount. One approach to gaining this type of knowledge is to observe pollutant fluxes at the watershed outlet. The River Eden Demonstration Test Catchments programme uses in-situ monitoring equipment to provide high-resolution (30 minute) data for three mixed-agriculture watersheds (ca. 10km2) in north western England. Determinands measured include turbidity, phosphorus, nitrate, chlorophyll-a, dissolved oxygen, conductivity, pH and temperature, along with river discharge and rainfall. Provided with these data, and an awareness of significant agricultural activities carried out in the watershed on an annual basis, this study demonstrates how it is possible to identify different pollutant transfer pathways, along with their spatio-temporal nature, and their relative importance. This information is then used to inform appropriate mitigation design. In relation to this purpose, the pros and cons of the different hydrochemical and hydrophysical data are described, and recommendations made for other determinands that should be considered for measurement in future similar studies.

  3. Metamodels and nonpoint pollution policy in agriculture

    NASA Astrophysics Data System (ADS)

    Bouzaher, Aziz; Lakshminarayan, P. G.; Cabe, Richard; Carriquiry, Alicia; Gassman, Philip W.; Shogren, Jason F.

    1993-06-01

    Complex mathematical simulation models are generally used for quantitative measurement of the fate of agricultural chemicals in soil. But it is less efficient to use them directly for regional water quality assessments because of the large number of simulations required to cover the entire region and because the entire set of simulation runs must be repeated for each new policy. To make regional water quality impact assessment on a timely basis, a simplified technique called metamodeling is suggested. A metamodel summarizes the input-output relationships in a complex simulation model designed to mimic actual processes such as groundwater leaching. Metamodels are constructed and validated to predict groundwater and surface water concentrations of major corn and sorghum herbicides in the Corn Belt and Lake States regions of the United States. The usefulness of metamodeling in the evaluation of agricultural nonpoint pollution policies is illustrated using an integrated environmental economic modeling system. For the baseline scenario, we estimate that 1.2% of the regional soils will lead to groundwater detection of atrazine exceeding 0.12 Mg/L, which compares well with the findings of an Environmental Protection Agency monitoring survey. The results suggest no-till practices could significantly reduce surface water concentration and a water quality policy, such as an atrazine ban, could increase soil erosion despite the conservation compliance provisions.

  4. NONPOINT SOURCES AND WATER QUALITY TRADING

    EPA Science Inventory

    Management of nonpoint sources (NPS) of nutrients may reduce discharge levels more cost effectively than can additional controls on point sources (PS); water quality trading (WQT), where a PS buys nutrient or sediment reductions from an NPS, may be an alternative means for the PS...

  5. Water Conservation and Nonpoint Source Pollution.

    ERIC Educational Resources Information Center

    Farrell-Poe, Kitt

    This book contains science activities that are designed to make learning and demonstrating nonpoint source pollution concepts exciting and fun. These activities can either be used alone or with an existing water resources education curricula. Activities include: Water Tasting, Acting Out the Hydrologic Cycle, Concentration of Chemical Pollutants…

  6. Geospatial data resampling and resolution effects on watershed modeling: A case study using the agricultural non-point source pollution model

    USGS Publications Warehouse

    Usery, E.L.; Finn, M.P.; Scheidt, D.J.; Ruhl, S.; Beard, T.; Bearden, M.

    2004-01-01

    Researchers have been coupling geographic information systems (GIS) data handling and processing capability to watershed and waterquality models for many years. This capability is suited for the development of databases appropriate for water modeling. However, it is rare for GIS to provide direct inputs to the models. To demonstrate the logical procedure of coupling GIS for model parameter extraction, we selected the Agricultural Non-Point Source (AGNPS) pollution model. Investigators can generate data layers at various resolutions and resample to pixel sizes to support models at particular scales. We developed databases of elevation, land cover, and soils at various resolutions in four watersheds. The ability to use multiresolution databases for the generation of model parameters is problematic for grid-based models. We used database development procedures and observed the effects of resolution and resampling on GIS input datasets and parameters generated from those inputs for AGNPS. Results indicate that elevation values at specific points compare favorably between 3- and 30-m raster datasets. Categorical data analysis indicates that land cover classes vary significantly. Derived parameters parallel the results of the base GIS datasets. Analysis of data resampled from 30-m to 60-, 120-, 210-, 240-, 480-, 960-, and 1920-m pixels indicates a general degradation of both elevation and land cover correlations as resolution decreases. Initial evaluation of model output values for soluble nitrogen and phosphorous indicates similar degradation with resolution. ?? Springer-Verlag 2004.

  7. Geospatial data resampling and resolution effects on watershed modeling: A case study using the agricultural non-point source pollution model

    NASA Astrophysics Data System (ADS)

    Usery, E. Lynn; Finn, Michael P.; Scheidt, Douglas J.; Ruhl, Sheila; Beard, Thomas; Bearden, Morgan

    2004-10-01

    Researchers have been coupling geographic information systems (GIS) data handling and processing capability to watershed and water-quality models for many years. This capability is suited for the development of databases appropriate for water modeling. However, it is rare for GIS to provide direct inputs to the models. To demonstrate the logical procedure of coupling GIS for model parameter extraction, we selected the Agricultural Non-Point Source (AGNPS) pollution model. Investigators can generate data layers at various resolutions and resample to pixel sizes to support models at particular scales. We developed databases of elevation, land cover, and soils at various resolutions in four watersheds. The ability to use multiresolution databases for the generation of model parameters is problematic for grid-based models. We used database development procedures and observed the effects of resolution and resampling on GIS input datasets and parameters generated from those inputs for AGNPS. Results indicate that elevation values at specific points compare favorably between 3- and 30-m raster datasets. Categorical data analysis indicates that land cover classes vary significantly. Derived parameters parallel the results of the base GIS datasets. Analysis of data resampled from 30-m to 60-, 120-, 210-, 240-, 480-, 960-, and 1920-m pixels indicates a general degradation of both elevation and land cover correlations as resolution decreases. Initial evaluation of model output values for soluble nitrogen and phosphorous indicates similar degradation with resolution.

  8. Costs and water quality effects of controlling point and nonpoint pollution sources

    SciTech Connect

    Macal, C.M.; Broomfield, B.J.

    1980-01-01

    Costs and water quality effects of controlling point and nonpoint pollution sources are compared for the DuPage River basin in northern Illinois. Costs are estimated for effluent standards for municipal wastewater treatment plants and for the alternative, controlling runoff from nonpoint sources such as streets, agricultural lands, and forests. A dynamic water-quality/hydrology simulation model is used to determine water quality effects of various treatment plant standards and nonpoint-source controls. Costs and water quality data are combined, and the point-source and nonpoint-source plans are compared on a cost-effectiveness basis. Nonpoint-source controls are found to be more cost-effective than stricter control of pollutants from point sources.

  9. Support vector machine-an alternative to artificial neuron network for water quality forecasting in an agricultural nonpoint source polluted river?

    PubMed

    Liu, Mei; Lu, Jun

    2014-09-01

    Water quality forecasting in agricultural drainage river basins is difficult because of the complicated nonpoint source (NPS) pollution transport processes and river self-purification processes involved in highly nonlinear problems. Artificial neural network (ANN) and support vector model (SVM) were developed to predict total nitrogen (TN) and total phosphorus (TP) concentrations for any location of the river polluted by agricultural NPS pollution in eastern China. River flow, water temperature, flow travel time, rainfall, dissolved oxygen, and upstream TN or TP concentrations were selected as initial inputs of the two models. Monthly, bimonthly, and trimonthly datasets were selected to train the two models, respectively, and the same monthly dataset which had not been used for training was chosen to test the models in order to compare their generalization performance. Trial and error analysis and genetic algorisms (GA) were employed to optimize the parameters of ANN and SVM models, respectively. The results indicated that the proposed SVM models performed better generalization ability due to avoiding the occurrence of overtraining and optimizing fewer parameters based on structural risk minimization (SRM) principle. Furthermore, both TN and TP SVM models trained by trimonthly datasets achieved greater forecasting accuracy than corresponding ANN models. Thus, SVM models will be a powerful alternative method because it is an efficient and economic tool to accurately predict water quality with low risk. The sensitivity analyses of two models indicated that decreasing upstream input concentrations during the dry season and NPS emission along the reach during average or flood season should be an effective way to improve Changle River water quality. If the necessary water quality and hydrology data and even trimonthly data are available, the SVM methodology developed here can easily be applied to other NPS-polluted rivers. PMID:24894753

  10. Compliance Groundwater Monitoring of Nonpoint Sources - Emerging Approaches

    NASA Astrophysics Data System (ADS)

    Harter, T.

    2008-12-01

    Groundwater monitoring networks are typically designed for regulatory compliance of discharges from industrial sites. There, the quality of first encountered (shallow-most) groundwater is of key importance. Network design criteria have been developed for purposes of determining whether an actual or potential, permitted or incidental waste discharge has had or will have a degrading effect on groundwater quality. The fundamental underlying paradigm is that such discharge (if it occurs) will form a distinct contamination plume. Networks that guide (post-contamination) mitigation efforts are designed to capture the shape and dynamics of existing, finite-scale plumes. In general, these networks extend over areas less than one to ten hectare. In recent years, regulatory programs such as the EU Nitrate Directive and the U.S. Clean Water Act have forced regulatory agencies to also control groundwater contamination from non-incidental, recharging, non-point sources, particularly agricultural sources (fertilizer, pesticides, animal waste application, biosolids application). Sources and contamination from these sources can stretch over several tens, hundreds, or even thousands of square kilometers with no distinct plumes. A key question in implementing monitoring programs at the local, regional, and national level is, whether groundwater monitoring can be effectively used as a landowner compliance tool, as is currently done at point-source sites. We compare the efficiency of such traditional site-specific compliance networks in nonpoint source regulation with various designs of regional nonpoint source monitoring networks that could be used for compliance monitoring. We discuss advantages and disadvantages of the site vs. regional monitoring approaches with respect to effectively protecting groundwater resources impacted by nonpoint sources: Site-networks provide a tool to enforce compliance by an individual landowner. But the nonpoint source character of the contamination

  11. Cost-effectiveness and cost-benefit analysis of BMPs in controlling agricultural nonpoint source pollution in China based on the SWAT model.

    PubMed

    Liu, Ruimin; Zhang, Peipei; Wang, Xiujuan; Wang, Jiawei; Yu, Wenwen; Shen, Zhenyao

    2014-12-01

    Best management practices (BMPs) have been widely used in managing agricultural nonpoint source pollution (ANSP) at the watershed level. Most BMPs are related to land use, tillage management, and fertilizer levels. In total, seven BMP scenarios (Reforest1, Reforest2, No Tillage, Contour tillage, and fertilizer level 1-4) that are related to these three factors were estimated in this study. The objectives were to investigate the effectiveness and cost-benefit of these BMPs on ANSP reduction in a large tributary of the Three Gorges Reservoir (TGR) in China, which are based on the simulation results of the Soil and Water Assessment Tool (SWAT) model. The results indicated that reforestation was the most economically efficient of all BMPs, and its net benefits were up to CNY 4.36×10(7) years(-1) (about USD 7.08×10(6) years(-1)). Regarding tillage practices, no tillage practice was more environmentally friendly than other tillage practices, and contour tillage was more economically efficient. Reducing the local fertilizer level to 0.8-fold less than that of 2010 can yield a satisfactory environmental and economic efficiency. Reforestation and fertilizer management were more effective in reducing total phosphorus (TP), whereas tillage management was more effective in reducing total nitrogen (TN). When CNY 10,000 (about USD 162) was applied to reforestation, no tillage, contour tillage, and an 0.8-fold reduction in the fertilizer level, then annual TN load can be reduced by 0.08, 0.16, 0.11, and 0.04 t and annual TP load can be reduced by 0.04, 0.02, 0.01 and 0.03 t, respectively. The cost-benefit (CB) ratios of the BMPs were as follows: reforestation (207 %) > contour tillage (129 %) > no tillage (114 %) > fertilizer management (96 and 89 %). The most economical and effective BMPs can be designated as follows: BMP1 (returning arable land with slopes greater than 25° to forests and those lands with slopes of 15-25° to orchards), BMP2 (implementing no tillage

  12. Controlling Nonpoint-Source Water Pollution: A Citizen's Handbook.

    ERIC Educational Resources Information Center

    Hansen, Nancy Richardson; And Others

    Citizens can play an important role in helping their states develop pollution control programs and spurring effective efforts to deal with nonpoint-source pollution. This guide takes the reader step-by-step through the process that states must follow to comply with water quality legislation relevant to nonpoint-source pollution. Part I provides…

  13. Simulation of nonpoint source contamination based on adaptive mesh refinement

    NASA Astrophysics Data System (ADS)

    Kourakos, G.; Harter, T.

    2014-12-01

    Contamination of groundwater aquifers from nonpoint sources is a worldwide problem. Typical agricultural groundwater basins receive contamination from a large array (in the order of ~10^5-6) of spatially and temporally heterogeneous sources such as fields, crops, dairies etc, while the received contaminants emerge at significantly uncertain time lags to a large array of discharge surfaces such as public supply, domestic and irrigation wells and streams. To support decision making in such complex regimes several approaches have been developed, which can be grouped into 3 categories: i) Index methods, ii)regression methods and iii) physically based methods. Among the three, physically based methods are considered more accurate, but at the cost of computational demand. In this work we present a physically based simulation framework which exploits the latest hardware and software developments to simulate large (>>1,000 km2) groundwater basins. First we simulate groundwater flow using a sufficiently detailed mesh to capture the spatial heterogeneity. To achieve optimal mesh quality we combine adaptive mesh refinement with the nonlinear solution for unconfined flow. Starting from a coarse grid the mesh is refined iteratively in the parts of the domain where the flow heterogeneity appears higher resulting in optimal grid. Secondly we simulate the nonpoint source pollution based on the detailed velocity field computed from the previous step. In our approach we use the streamline model where the 3D transport problem is decomposed into multiple 1D transport problems. The proposed framework is applied to simulate nonpoint source pollution in the Central Valley aquifer system, California.

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

    PubMed

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

    2016-01-01

    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. PMID:27533862

  15. NATIONAL MANAGEMENT MEASURES TO CONTROL NONPOINT SOURCE POLLUTION FROM HYDROMODIFICATION

    EPA Science Inventory

    Hydromodification What Are the Nonpoint Source-Related Problems Associated with Hydromodification? Hydromodification activities have been separated into the categories of channelization and channel modification, dams, and streambank and shoreline erosion. A frequent result of c...

  16. Management of an Abandoned River Channel Wetland for Mitigation of Nonpoint Source Pollution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduction of nonpoint source pollutants, principally sediment and nutrients moving from cultivated fields to surface waters, is a major challenge. Remnants of once-extensive natural wetlands occur across the agricultural landscape, and some workers have suggested that these areas might be managed t...

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

    ERIC Educational Resources Information Center

    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…

  18. Biodetention: A best management practice for nonpoint source pollution

    SciTech Connect

    Murfee, G.; Scaief, J.; Whelan, M.

    1998-07-01

    Biodetention is an innovative nonpoint source (NPS) pollution control best management practice (BMP) developed as an alternative to sedimentation/filtration ponds. Biodetention is applicable as a runoff treatment system for concentrated point discharges from stormwater collection facilities. Treatment is facilitated by vegetative filter strips and stiff grass hedges.

  19. Better Assessment Science Integrating Point and Nonpoint Sources

    EPA Science Inventory

    Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is not a model per se, but is a multipurpose environmental decision support system for use by regional, state, and local agencies in performing watershed- and water-quality-based studies. BASI...

  20. RECOGNIZING FARMERS' ATTITUDES AND IMPLEMENTING NONPOINT SOURCE POLLUTION CONTROL POLICIES

    EPA Science Inventory

    This report examines the role of farmer attitudes and corresponding communication activities in the implementation of nonpoint source water pollution control programs. The report begins with an examination of the basis for and function of attitudes in influencing behavior. The ro...

  1. NONPOINT SOURCE - STREAM NUTRIENT LEVEL RELATIONSHIPS: A NATIONWIDE STUDY

    EPA Science Inventory

    National Eutrophication Survey (NES) data for a nationwide collection of 928 non-point source watersheds were studied for relationships between macro-drainage area characteristics (particularly land use) and nutrient levels in streams. Both the total and inorganic forms of phosph...

  2. 40 CFR 35.1605-4 - Nonpoint source.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Nonpoint source. 35.1605-4 Section 35.1605-4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned...

  3. 40 CFR 35.1605-4 - Nonpoint source.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Nonpoint source. 35.1605-4 Section 35.1605-4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned...

  4. 40 CFR 35.1605-4 - Nonpoint source.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Nonpoint source. 35.1605-4 Section 35.1605-4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned...

  5. 40 CFR 35.1605-4 - Nonpoint source.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Nonpoint source. 35.1605-4 Section 35.1605-4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned...

  6. 40 CFR 35.1605-4 - Nonpoint source.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Nonpoint source. 35.1605-4 Section 35.1605-4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned...

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

    USGS Publications Warehouse

    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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Spatiotemporal nonpoint source pollution water quality management framework using bi-directional model-GIS linkage

    SciTech Connect

    Faizullabhoy, M.S.; Yoon, J.

    1999-07-01

    A framework for water quality assessment and management purposes was developed. In this framework, a bilateral linkage was implemented between the distributed model, Agricultural Nonpoint Source Pollution Model (AGNPS) and the Geographic Information System (GIS) to investigate a spatiotemporal nonpoint source pollution problem from a 750-acre watershed in the NSGA (Naval Security Group Activity) Northwest base at the Virginia/North Carolina border. AGNPS is an event-based, distributed parameter model that simulates runoff and the transport of sediment and nutrients (nitrogen and phosphorus) from predominantly agricultural watersheds. In this study rather than manually implementing AGNPS simulation, extracted data are integrated in an automated fashion through a direct bilateral linkage framework between the AGNPS model engine and the GIS. This bilateral linkage framework resulted in a powerful, up-to-date tool that would be capable of monitoring and instantaneously visualizing the transport of any pollutant as well as effectively identifying critical areas of the nonpoint source (NPS) pollution. The framework also allowed the various what if scenarios to support the decision-making processes. Best Management Practices (BMP) for the watershed can be generated in a close loop iterative scheme, until predefined management objectives are achieved. Simulated results showed that the optimal BMP scenario achieved an average reduction of about 41% in soluble and sediment-attached nitrogen and about 62% reduction in soluble and sediment phosphorus from current NPS pollution levels.

  10. Mining-related nonpoint-source pollution

    SciTech Connect

    Cohen, R.H.; Gorman, J. )

    1991-06-01

    This article describes the effects of increased mining activity on surface and groundwater. The topics covered include pollutant sources, contaminant transport and fate, trace element toxicity, pollution control and abatement, treating acid mine drainage, modern constructed wetlands and site reclamation including site stabilization, refuse burial and sludge application.

  11. [Estimation of nonpoint source pollutant loads and optimization of the best management practices (BMPs) in the Zhangweinan River basin].

    PubMed

    Xu, Hua-Shan; Xu, Zong-Xue; Liu, Pin

    2013-03-01

    One of the key techniques in establishing and implementing TMDL (total maximum daily load) is to utilize hydrological model to quantify non-point source pollutant loads, establish BMPs scenarios, reduce non-point source pollutant loads. Non-point source pollutant loads under different years (wet, normal and dry year) were estimated by using SWAT model in the Zhangweinan River basin, spatial distribution characteristics of non-point source pollutant loads were analyzed on the basis of the simulation result. During wet years, total nitrogen (TN) and total phosphorus (TP) accounted for 0.07% and 27.24% of the total non-point source pollutant loads, respectively. Spatially, agricultural and residential land with steep slope are the regions that contribute more non-point source pollutant loads in the basin. Compared to non-point source pollutant loads with those during the baseline period, 47 BMPs scenarios were set to simulate the reduction efficiency of different BMPs scenarios for 5 kinds of pollutants (organic nitrogen, organic phosphorus, nitrate nitrogen, dissolved phosphorus and mineral phosphorus) in 8 prior controlled subbasins. Constructing vegetation type ditch was optimized as the best measure to reduce TN and TP by comparing cost-effective relationship among different BMPs scenarios, and the costs of unit pollutant reduction are 16.11-151.28 yuan x kg(-1) for TN, and 100-862.77 yuan x kg(-1) for TP, which is the most cost-effective measure among the 47 BMPs scenarios. The results could provide a scientific basis and technical support for environmental protection and sustainable utilization of water resources in the Zhangweinan River basin. PMID:23745390

  12. Fine-scale chemical exposure differs in point and nonpoint source plumes.

    PubMed

    Lahman, Sara E; Moore, Paul A

    2015-05-01

    Increasing influxes of anthropogenic chemicals into aquatic ecosystems has led to growing global concern surrounding human and ecosystem health. As more freshwater systems are deemed not potable or usable for agricultural purposes, more attention is being paid to remediation and mitigation efforts. Predicting and preventing the impacts of the chemical inputs first requires a thorough understanding of the spatio-temporal distribution of chemical plumes in natural habitats. Plume dispersion is intimately tied to fluid mechanics; therefore, alterations in the way that chemical plumes are introduced to habitats can have profound effects on chemical distribution. Such alterations can subsequently alter the exposure to which organisms are subjected. This study examined the influence of point versus nonpoint sources in structuring the distribution of chemicals in a simulated flowing freshwater habitat. The fine-scale (molecular) spatio-temporal distribution of chemicals was measured in situ using an electrochemical detector. Molecular concentration at varying distance and height from the source was quantified using dopamine coupled with an electrochemical detection system. The fine-scale distribution of chemical plumes from point and nonpoint sources showed significant differences in how organisms will be exposed to chemicals. Overall, this study characterized plumes from nonpoint sources as having significantly longer peak lengths and rise times as well as greater peak heights and maximum slopes than plumes from point sources, thus providing a significantly different exposure paradigm. This quantification of how chemicals move differently throughout a fluid medium when introduced from point and nonpoint sources allows a greater understanding of how chemical plumes can potentially affect aquatic ecosystems. PMID:25552326

  13. Modeling effects of nitrate from non-point sources on groundwater quality in an agricultural watershed in Prince Edward Island, Canada

    NASA Astrophysics Data System (ADS)

    Jiang, Yefang; Somers, George

    2009-05-01

    Intensification of potato farming has contaminated groundwater with nitrate in many cases in Prince Edward Island, Canada, which raises concerns for drinking water quality and associated ecosystem protection. Numerical models were developed to simulate nitrate-N transport in groundwater and enhance understanding of the impacts of farming on water quality in the Wilmot River watershed. Nitrate is assumed non-reactive based on δ15N and δ18O in nitrate and geochemical information. The source functions were reconstructed from tile drain measurements, N budget and historical land-use information. The transport model was calibrated to long-term nitrate-N observations in the Wilmot River and verified against nitrate-N measurements in two rivers from watersheds with similar physical conditions. Simulations show groundwater flow is stratified and vertical flux decreases exponentially with depth. While it would take several years to reduce the nitrate-N in the shallow portion of the aquifer, it would take several decades or even longer to restore water quality in the deeper portions of the aquifer. Elevated nitrate-N concentrations in base flow are positively correlated with potato cropping intensity and significant reductions in nitrate-N loading are required if the nitrate level of surface water is to recover to the standard in the Canadian Water Quality Guidelines.

  14. [Purification capacity of ditch wetland to agricultural non-point pollutants].

    PubMed

    Jiang, Cui-ling; Cui, Guang-bo; Fan, Xiao-qiu; Zhang, Yi-bing

    2004-03-01

    Ditch wetlands have the capacity to remove and purify non-point pollutants from agricultural drainage by sediment retention, plant absorption and microorganism decomposition. Phragmites communis and Zizania latifolia are two main kinds of plants growing naturally in ditch wetlands in the lower reaches of the Yangtze River. They can absorb N and P efficiently, which is the main mechanism of non-point source pollutants purification by wetlands. The harvest of Phragmites communis and Zizania latifolia will take away 463-515 kg/hm2 of N and 127-149 kg/hm2 of P each year, it equal to N and P discharged from 2.3-3.2 hm2 and 1.3-3.0 hm2 of fields respectively in this area. The absorption and decomposition capacity of Zizania latifolia wetland is higher than Phragmites communis wetland. After harvest of plants, wetlands are uncovered to sunlight and oxygen that speeds the transportation and decomposition of nutrients. The amount of organic matters, TN and TP are higher in sediment of harvested area than in that of control. Therefore, seasonal harvest of plants is an efficient measure for wetlands to purify nutrients and alleviate eutrophication of lakes. PMID:15202249

  15. [Transformation of Non-point Source Soluble Nitrogen in Simulated Drainage Ditch].

    PubMed

    Li, Qiang-kun; Song, Chang-ji; Hu, Ya-wei; Peng, Cong; Ma, Qiang; Jiang, Zheng-xi; Ju, Yi-rheng

    2016-02-15

    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. PMID:27363139

  16. Advanced information technologies for assessing nonpoint source pollution in the vadose zone: Conference overview

    SciTech Connect

    Corwin, D.L.; Loague, K.; Ellsworth, T.R.

    1999-03-01

    The information age has ushered in an awareness of and concern for global environmental problems such as climatic change, ozone depletion, deforestation, desertification, and nonpoint source (NPS) pollution. Nonpoint source pollution is the single greatest threat to surface and subsurface drinking water resources. Nonpoint source pollutants also pose a threat to sustainable agriculture, which is viewed as the most viable means of meeting the food demands of a world population that is expected to reach 9.4 billion by the middle of the next century. The ability to accurately assess present and future NPS pollution impacts on ecosystems ranging from local to global scales would provide a powerful tool for environmental stewardship and guiding future human activities. Assessing NPS pollutant is a multidisciplinary problem. To address the problem, advanced information technologies and methodologies are needed that draw from all areas of science and are applied in a spatial context. It was from this setting that the 1997 Joint AGU Chapman/SSSA Outreach Conference Application of GIS, Remote Sensing, Geostatistics, and Solute Transport Modeling for Assessing Nonpoint Source Pollutants in the Vadose Zone (19--24 Oct. 1997, Riverside, CA) materialized. The objective of the conference was to examine current multidisciplinary technologies and methodologies for assessing NPS pollutants in the vadose zone, and to explore new conceptual approaches. It was the conference`s goal to provide a forum to stimulate multidisciplinary interaction to enhance the development of techniques for the real-time measurement and modeling of NPS pollution in the vadose zone and subsurface waters.

  17. 40 CFR 125.64 - Effect of the discharge on other point and nonpoint sources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 22 2011-07-01 2011-07-01 false Effect of the discharge on other point... § 125.64 Effect of the discharge on other point and nonpoint sources. (a) No modified discharge may result in any additional pollution control requirements on any other point or nonpoint source. (b)...

  18. 40 CFR 125.64 - Effect of the discharge on other point and nonpoint sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Effect of the discharge on other point... § 125.64 Effect of the discharge on other point and nonpoint sources. (a) No modified discharge may result in any additional pollution control requirements on any other point or nonpoint source. (b)...

  19. Introduction to nonpoint-source pollution and wetland mitigation

    SciTech Connect

    Baker, L.A.

    1991-09-12

    Nonpoint source pollution (NPS) is the major cause of impairment of U.S. surface waters. Erosion from croplands has been declining but is not yet reflected in decreased sediment yield or phosphorus concentrations in the nation's rivers. Nitrogen pollution is of particular concern in eutophication of estuaries as a contaminant of groundwater, and as an acidifying agent in atmospheric deposition. Nitrogen fertilizer and emissions of nitrous oxides are major contributors to the problem. The outlook on pesticides is mixed: bans on organochlorine pesticides in the 1970s have resulted in decreasing concentrations in fish tissue; however, herbicides are now a problem for some surface and groundwater sources of drinking water, especially in the Upper Midwest.

  20. Agricultural Land Use and Best Management Practices to Control Nonpoint Water Pollution

    NASA Astrophysics Data System (ADS)

    Ripa, Maria Nicoletta; Leone, Antonio; Garnier, Monica; Porto, Antonio Lo

    2006-08-01

    In recent years, improvements in point-source depuration technologies have highlighted the problems regarding agricultural nonpoint (diffuse) sources, and this issue has become highly relevant from the environmental point of view. The considerable extension of the areas responsible for this kind of pollution, together with the scarcity of funds available to local managers, make minimizing the impacts of nonpoint sources on a whole basin a virtually impossible task. This article presents the results of a study intended to pinpoint those agricultural areas, within a basin, that contribute most to water pollution, so that operations aimed at preventing and/or reducing this kind of pollution can be focused on them. With this aim, an innovative approach is presented that integrates a field-scale management model, a simple regression model, and a geographic information system (GIS). The Lake Vico basin, where recent studies highlighted a considerable increase in the trophic state, mainly caused by phosphorus (P) compounds deriving principally from the intensive cultivation of hazelnut trees in the lake basin, was chosen as the study site. Using the management model Groundwater Loading Effects of Agricultural Management Systems (GLEAMS), the consequences, in terms of sediment yield and phosphorus export, of hazelnut tree cultivation were estimated on different areas of the basin with and without the application of a best management practice (BMP) that consists of growing meadow under the trees. The GLEAMS results were successively extended to basin scale thanks to the application of a purposely designed regression model and of a GIS. The main conclusions can be summarized as follows: The effectiveness of the above-mentioned BMP is always greater for erosion reduction than for particulate P reduction, whatever the slope value considered; moreover, the effectiveness with reference to both particulate P and sediment yield production decreases as the slope increases. The

  1. Agricultural land use and best management practices to control nonpoint water pollution.

    PubMed

    Ripa, Maria Nicoletta; Leone, Antonio; Garnier, Monica; Lo Porto, Antonio

    2006-08-01

    In recent years, improvements in point-source depuration technologies have highlighted the problems regarding agricultural nonpoint (diffuse) sources, and this issue has become highly relevant from the environmental point of view. The considerable extension of the areas responsible for this kind of pollution, together with the scarcity of funds available to local managers, make minimizing the impacts of nonpoint sources on a whole basin a virtually impossible task. This article presents the results of a study intended to pinpoint those agricultural areas, within a basin, that contribute most to water pollution, so that operations aimed at preventing and/or reducing this kind of pollution can be focused on them. With this aim, an innovative approach is presented that integrates a field-scale management model, a simple regression model, and a geographic information system (GIS). The Lake Vico basin, where recent studies highlighted a considerable increase in the trophic state, mainly caused by phosphorus (P) compounds deriving principally from the intensive cultivation of hazelnut trees in the lake basin, was chosen as the study site. Using the management model Groundwater Loading Effects of Agricultural Management Systems (GLEAMS), the consequences, in terms of sediment yield and phosphorus export, of hazelnut tree cultivation were estimated on different areas of the basin with and without the application of a best management practice (BMP) that consists of growing meadow under the trees. The GLEAMS results were successively extended to basin scale thanks to the application of a purposely designed regression model and of a GIS. The main conclusions can be summarized as follows: The effectiveness of the above-mentioned BMP is always greater for erosion reduction than for particulate P reduction, whatever the slope value considered; moreover, the effectiveness with reference to both particulate P and sediment yield production decreases as the slope increases. The

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

    PubMed

    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

  3. a Study on the Comprehensive Simulation of Nonpoint Source Pollution for Er-Hai Lake's Watershed in Dali of China

    NASA Astrophysics Data System (ADS)

    Yang, K.; Xu, Q. L.; Ye, L. Y.

    2012-07-01

    Er-hai Lake lies in state of Dali of Yunnan Province in China, which is so important to the local people that they revere her as the Mother Lake. Unfortunately, she is threatened by the more serious pollution of water. And from the water quality assessment of Er-hai Lake over the years, it is indicated that the major water pollution source come from nonpoint source pollution. The argument is that what has formed the nonpoint source pollution? As we known, the land use and cover change of watershed called LUCC is deemed as the major reason for Non-point pollution of water. However, what has made the land use and cover changes? It is another important question we should give an answer for water pollution. Many evidences have given that the change of LUCC is more due to the human activities in watershed, especially those for agriculture production. Thereby, there is a chain process for water pollution formation in Er-hai Lake Watershed, which could be described like this: Human activities (more in agriculture) have changed LUCC, and LUCC leads non-point source pollution. As a result, in this paper, those have been discussed according to the driving mechanism of nonpoint source water pollution in Er-hai Lake, which include three explorations. The first is how to build a ABM-LUCC model by using Repast and GIS technology, and the second is the method and implementation for hydrological and water quality model by using SWAT model and GIS, as well as Remote Sensing technology. And establishing a platform for comprehensively simulating the whole process of water pollution by integrating GIS, ABM-LUCC models and hydrological models is the last work for this study.

  4. Controlled-release fertilizer (CRF): a green fertilizer for controlling non-point contamination in agriculture.

    PubMed

    Mao, Xiao-yun; Sun, Ke-jun; Wang, De-han; Liao, Zong-wen

    2005-01-01

    Fertilizers contribute greatly to high yields but also result in environmental non-point contamination, including the emission of greenhouse gas (N2O) and eutrophication of water bodies. How to solve this problem has become a serious challenge, especially for China as its high ecological pressure. Controlled-release fertilizer(CRF) has been developed to minimize the contamination while keeping high yield and has become a green fertilizer for agriculture. Several CRFs made with special coating technology were used for testing the fertilizer effects in yield and environment through pot experiment and field trial. The result indicated that the CRFs had higher N use efficiency, thus reducing N loss through leaching and volatilization while keeping higher yields. Comparing with imported standard CRFs, the test on CRFs showed similar fertilizer effect but with much lower cost. CRFs application is becoming a new approach for minimizing non-point contamination in agriculture. PMID:16295884

  5. Natural Wetlands Mediate Non-point Source Water Pollution From Irrigated Pastures

    NASA Astrophysics Data System (ADS)

    Knox, K.; Dahlgren, R. A.; Tate, K. W.

    2005-12-01

    Non-point source discharge from grazed pastures may be high in nutrients, sediment, and pathogens, three major contributors to water quality impairment in California. Intercepting pollution at its source and managing water quality within the landscape are essential to maintaining healthy downstream waters. We investigated the efficacy of flow-through wetlands interspersed throughout the agricultural landscape to reduce non-point source pollution of tailwater from cattle-grazed, irrigated pastures in the Sierra Nevada Foothills of California. Wetlands are known to positively impact water quality through ecological processes such as filtration, sedimentation, microbial transformations and plant uptake of nutrients. Influent and effluent water of small (0.25 ha), natural wetlands located downstream from flood irrigated pastures was analyzed for Escherichia coli, NO3-N, total N, total suspended solids (TSS), total P, and dissolved organic carbon (DOC) throughout two summer irrigation seasons (June to October). We compared reductions of sediment, nutrients and E. coli provided by a healthy, non-degraded wetland with reductions from flow through a channelized, degraded wetland. Large reductions in E. coli (>75%) and TSS (>50%) were observed in water exiting the healthy wetland while nutrient and DOC (~ 20%) concentrations were less affected by flow through the wetland. The channelized wetland provided smaller reductions in all constituents than did the non-degraded wetland. Results from this study demonstrate that small flow-through wetlands can improve water quality through the attenuation of E. coli and suspended sediments, and to a lesser degree DOC and nutrients.

  6. Emerging policies to control nonpoint source pollution of groundwater

    NASA Astrophysics Data System (ADS)

    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.

  7. UNCERTAINTY IN LEACHING POTENTIAL OF NONPOINT SOURCE POLLUTANTS WITH APPLICATION TO A GIS

    EPA Science Inventory

    This paper presents a stochastic framework for the assessment of groundwater pollution potential of nonpoint source pesticides. A conceptual relationship is presented that relates seasonally averaged groundwater recharge to soil properties and depths to the water table. The analy...

  8. Snowmelt runoff: a new focus of urban nonpoint source pollution.

    PubMed

    Zhu, Hui; Xu, Yingying; Yan, Baixing; Guan, Jiunian

    2012-12-01

    Irregular precipitation associated with global climate change had been causing various problems in urban regions. Besides the runoff due to rainfall in summer, the snowmelt runoff in early spring could also play an important role in deteriorating the water quality of the receiving waters. Due to global climate change, the snowfall has increased gradually in individual regions, and snowstorms occur more frequently, which leads to an enhancement of snowmelt runoff flow during the melting seasons. What is more, rivers just awaking from freezing constitute a frail ecosystem, with poor self-purification capacity, however, the urban snowmelt runoff could carry diverse pollutants accumulated during the winter, such as coal and/or gas combustion products, snowmelting agents, automotive exhaust and so on, which seriously threaten the receiving water quality. Nevertheless, most of the research focused on the rainfall runoff in rainy seasons, and the study on snowmelt runoff is still a neglected field in many countries and regions. In conclusion, due to the considerable water quantity and the worrisome water quality, snowmelt runoff in urban regions with large impervious surface areas should be listed among the important targets in urban nonpoint source pollution management and control. PMID:23202881

  9. Snowmelt Runoff: A New Focus of Urban Nonpoint Source Pollution

    PubMed Central

    Zhu, Hui; Xu, Yingying; Yan, Baixing; Guan, Jiunian

    2012-01-01

    Irregular precipitation associated with global climate change had been causing various problems in urban regions. Besides the runoff due to rainfall in summer, the snowmelt runoff in early spring could also play an important role in deteriorating the water quality of the receiving waters. Due to global climate change, the snowfall has increased gradually in individual regions, and snowstorms occur more frequently, which leads to an enhancement of snowmelt runoff flow during the melting seasons. What is more, rivers just awaking from freezing cosntitute a frail ecosystem, with poor self-purification capacity, however, the urban snowmelt runoff could carry diverse pollutants accumulated during the winter, such as coal and/or gas combustion products, snowmelting agents, automotive exhaust and so on, which seriously threaten the receiving water quality. Nevertheless, most of the research focused on the rainfall runoff in rainy seasons, and the study on snowmelt runoff is still a neglected field in many countries and regions. In conclusion, due to the considerable water quantity and the worrisome water quality, snowmelt runoff in urban regions with large impervious surface areas should be listed among the important targets in urban nonpoint source pollution management and control. PMID:23202881

  10. Simulation of Non-point Source Pollution in the Songhua River Basin Using GBNP Model

    NASA Astrophysics Data System (ADS)

    Pan, J.; Tang, L.; Chen, Y. D.

    2015-12-01

    China is facing increasingly severe water pollution issue with rapid socio-economic development. Non-point source pollution, which is rarely monitored, has become the main forms of water pollution in China. In this study, the Geomorphology-Based Non-point source Pollution (GBNP) model was used to simulate the processes of rain-runoff, soil erosion, sediment routing and pollutant transport in the Songhua River basin from 2001 to 2010. The spatio-temporal variation of non-point source pollution and river water quality were analyzed based on the simulation outputs. In the entire basin, the annual mean loading of TN, TP and soil erosion are 270,000 ton/a, 42,200 ton/a and 55,900,000 ton/a, respectively. The point and non-point source pollution respectively account for 44.9% and 55.1% in TN loading. For TP loading, the proportions of point and non-point source pollution are 14.4% and 85.6%, respectively. It suggests that the non-point source pollution control and treatments should be paid more attention in the Songhua River basin. The inter-annual and intra-annual variations of non-point source pollution components and potential driving mechanisms are further examined. The annual loading of soil erosion, TN and TP are highly correlated with annual runoff, with the correlation coefficients of 0.75, 0.91 and 0.92, respectively, which implies that rain-runoff could be the main driving force of non-point pollution. The monthly sediment concentration in the watercourse is high in flood season and low in non-flood season, which agrees well with the seasonality of monthly runoff. By contrast, the concentrations of TN and TP in watercourse show the opposite features.

  11. Association of multiple-antibiotic-resistance profiles with point and nonpoint sources of Escherichia coli in Apalachicola Bay.

    PubMed

    Parveen, S; Murphree, R L; Edmiston, L; Kaspar, C W; Portier, K M; Tamplin, M L

    1997-07-01

    A total of 765 Escherichia coli isolates from point and nonpoint sources were collected from the Apalachicola National Estuarine Research Reserve, and their multiple-antibiotic-resistance (MAR) profiles were determined with 10 antibiotics. E. coli isolates from point sources showed significantly greater resistance (P < 0.05) to antibiotics and higher MAR indices than isolates from nonpoint sources. Specifically, 65 different resistance patterns were observed among point source isolates, compared to 32 among nonpoint source isolates. Examples of this contrast in MAR profiles included percentages of isolates with resistance to chlortetracycline-sulfathiazole of 33.7% and to chlortetracycline-penicillin G-sulfathiazole of 14.5% for point source isolates versus 15.4 and 1.7%, respectively, for nonpoint source isolates. MAR profile homology, based on coefficient similarity, showed that isolates from point sources were markedly more diverse than isolates from nonpoint sources. Seven clusters were observed among point source isolates, with a coefficient value of approximately 1.8. In contrast, only four clusters were observed among nonpoint source isolates. Covariance matrices of data displayed six very distinct foci representing nonpoint source E. coli isolates. Importantly, E. coli isolates obtained directly from human and animal feces also clustered among point and nonpoint sources, respectively. We conclude that E. coli MAR profiles were associated with point and nonpoint sources of pollution within Apalachicola Bay and that this method may be useful in facilitating management of other estuaries. PMID:9212410

  12. The economic impact of remote sensing data as the source of nonpoint pollution monitoring and control

    NASA Technical Reports Server (NTRS)

    Miller, W. L.

    1974-01-01

    Nonpoint pollution of streams with sediment as a result of runoff from alternative uses of land has become a socially unacceptable product of economic activity. This report describes a research approach to economically achieve correction of the nonpoint pollution problem. The research approach integrates the economic model with those data which may be obtainable from remotely sensed sources. The economic problem involves measurement of the direct benefits and costs associated with the changes in land management activities necessary to reduce the level of nonpoint pollution. Remotely sensed data from ERTS-1 may provide some of the information required for the economic model which indicates efficient solutions to the nonpoint pollution problem. Three classes of data (i.e., soil categories, vegetative cover, and water turbidity) have the potential to be measured by ERTS-1 systems. There is substantial research which indicates the ability of ERTS-1 to measure these classes of data under selected conditions.

  13. Nonpoint sources of volatile organic compounds in urban areas - Relative importance of land surfaces and air

    USGS Publications Warehouse

    Lopes, T.J.; Bender, D.A.

    1998-01-01

    Volatile organic compounds (VOCs) commonly detected in urban waters across the United States include gasoline-related compounds (e.g. toluene, xylene) and chlorinated compounds (e.g. chloroform, tetrachloroethane [PCE], trichloroethene [TCE]). Statistical analysis of observational data and results of modeling the partitioning of VOCs between air and water suggest that urban land surfaces are the primary nonpoint source of most VOCs. Urban air is a secondary nonpoint source, but could be an important source of the gasoline oxygenate methyl-tert butyl ether (MTBE). Surface waters in urban areas would most effectively be protected by controlling land-surface sources.

  14. Evaluating changes in water quality with respect to nonpoint source nutrient management strategies in the Chesapeake Bay Watershed

    NASA Astrophysics Data System (ADS)

    Keisman, J.; Sekellick, A.; Blomquist, J.; Devereux, O. H.; Hively, W. D.; Johnston, M.; Moyer, D.; Sweeney, J.

    2014-12-01

    Chesapeake Bay is a eutrophic ecosystem with periodic hypoxia and anoxia, algal blooms, diminished submerged aquatic vegetation, and degraded stocks of marine life. Knowledge of the effectiveness of actions taken across the watershed to reduce nitrogen (N) and phosphorus (P) loads to the bay (i.e. "best management practices" or BMPs) is essential to its restoration. While nutrient inputs from point sources (e.g. wastewater treatment plants and other industrial and municipal operations) are tracked, inputs from nonpoint sources, including atmospheric deposition, farms, lawns, septic systems, and stormwater, are difficult to measure. Estimating reductions in nonpoint source inputs attributable to BMPs requires compilation and comparison of data on water quality, climate, land use, point source discharges, and BMP implementation. To explore the relation of changes in nonpoint source inputs and BMP implementation to changes in water quality, a subset of small watersheds (those containing at least 10 years of water quality monitoring data) within the Chesapeake Watershed were selected for study. For these watersheds, data were compiled on geomorphology, demographics, land use, point source discharges, atmospheric deposition, and agricultural practices such as livestock populations, crop acres, and manure and fertilizer application. In addition, data on BMP implementation for 1985-2012 were provided by the Environmental Protection Agency Chesapeake Bay Program Office (CBPO) and the U.S. Department of Agriculture. A spatially referenced nonlinear regression model (SPARROW) provided estimates attributing N and P loads associated with receiving waters to different nutrient sources. A recently developed multiple regression technique ("Weighted Regressions on Time, Discharge and Season" or WRTDS) provided an enhanced understanding of long-term trends in N and P loads and concentrations. A suite of deterministic models developed by the CBPO was used to estimate expected

  15. Quantifying the uncertainty of nonpoint source attribution in distributed water quality models: A Bayesian assessment of SWAT's sediment export predictions

    NASA Astrophysics Data System (ADS)

    Wellen, Christopher; Arhonditsis, George B.; Long, Tanya; Boyd, Duncan

    2014-11-01

    Spatially distributed nonpoint source watershed models are essential tools to estimate the magnitude and sources of diffuse pollution. However, little work has been undertaken to understand the sources and ramifications of the uncertainty involved in their use. In this study we conduct the first Bayesian uncertainty analysis of the water quality components of the SWAT model, one of the most commonly used distributed nonpoint source models. Working in Southern Ontario, we apply three Bayesian configurations for calibrating SWAT to Redhill Creek, an urban catchment, and Grindstone Creek, an agricultural one. We answer four interrelated questions: can SWAT determine suspended sediment sources with confidence when end of basin data is used for calibration? How does uncertainty propagate from the discharge submodel to the suspended sediment submodels? Do the estimated sediment sources vary when different calibration approaches are used? Can we combine the knowledge gained from different calibration approaches? We show that: (i) despite reasonable fit at the basin outlet, the simulated sediment sources are subject to uncertainty sufficient to undermine the typical approach of reliance on a single, best fit simulation; (ii) more than a third of the uncertainty of sediment load predictions may stem from the discharge submodel; (iii) estimated sediment sources do vary significantly across the three statistical configurations of model calibration despite end-of-basin predictions being virtually identical; and (iv) Bayesian model averaging is an approach that can synthesize predictions when a number of adequate distributed models make divergent source apportionments. We conclude with recommendations for future research to reduce the uncertainty encountered when using distributed nonpoint source models for source apportionment.

  16. Nonpoint sources as external threats to coastal water quality: lessons from Park Service experience

    USGS Publications Warehouse

    Burroughs, R.H.

    1993-01-01

    Program design for nonpoint source control was considered through an analogous problem, external threats to national parks. Nonpoint sources are diffuse land activities that degrade water quality, and recent federal legislation seeks to limit them in coastal areas. External threats occur outside a park boundary but affect the purposes for, or resources within, a park. They have been subject to federal management for many decades. Nonpoint sources are a class of external threat. Therefore, programs to limit them should consider techniques used in part protection. These park techniques include 'hard approaches', which rely on power, usually through legal devices, and 'soft approaches', which utilize shared values and objectives. A linked approach, as exemplified at the Cape Cod National Seashore, appears most promising. In a linked approach, if a soft approach fails, the manager of the protected unit is empowered to take an alternative hard action to protect the resource.

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

    NASA Astrophysics Data System (ADS)

    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

  18. Water quality indicators and the risk of illness at beaches with nonpoint sources of fecal contaminants

    EPA Science Inventory

    BACKGROUND: Indicator bacteria are a good predictor of illness at marine beaches that have point sources of pollution with human fecal content. Few studies have addressed the utility of indicator bacteria where nonpoint sources are the dominant fecal input. Extrapolating current ...

  19. Relationships Between Landscape Characteristics and Nonpoint Source Pollution Inputs to Coastal Estuaries.

    PubMed

    BASNYAT; TEETER; FLYNN; LOCKABY

    1999-05-01

    / Land-use activities affect water quality by altering sediment, chemical loads, and watershed hydrology. Some land uses may contribute to the maintenance of water quality due to a biogeochemical transformation process. These land-use/land-cover types can serve as nutrient detention zones or as nutrient transformation zones as dissolved or suspended nutrients or sediments move downstream. Despite research on the effects of individual land-use/land-cover types, very little has been done to analyze the joint contributions of multiple land-use activities. This paper examines a methodology to assess the relationships between land-use complex and nitrate and sediment concentrations [nonpoint source (NPS) pollutants] in streams. In this process, selected basins of the Fish River, Alabama, USA, were delineated, land-use/land-cover types were classified, and contributing zones were identified using geographic information system (GIS) and remote sensing (RS) analysis tools. Water samples collected from these basins were analyzed for selected chemical and physical properties. Based on the contributions of the NPS pollutants, a linkage model was developed. This linkage model relates land use/land cover with the pollution levels in the stream. Linkage models were constructed and evaluated at three different scales: (1) the basin scale; (2) the contributing-zone scale; and (3) the stream-buffer/riparian-zone scale. The contributing-zones linkage model suggests that forests act as a transformation zone, and as the proportion of forest inside a contributing zone increases (or agricultural land decreases), nitrate levels downstream will decrease. Residential/urban/built-up areas were identified as the strongest contributors of nitrate in the contributing-zones model and active agriculture was identified as the second largest contributor. The regression results for the streambank land-use/land-cover model (stream-buffer/riparian-zone scale) suggest that water quality is highest

  20. Nonpoint source pollution of urban stormwater runoff: a methodology for source analysis.

    PubMed

    Petrucci, Guido; Gromaire, Marie-Christine; Shorshani, Masoud Fallah; Chebbo, Ghassan

    2014-09-01

    The characterization and control of runoff pollution from nonpoint sources in urban areas are a major issue for the protection of aquatic environments. We propose a methodology to quantify the sources of pollutants in an urban catchment and to analyze the associated uncertainties. After describing the methodology, we illustrate it through an application to the sources of Cu, Pb, Zn, and polycyclic aromatic hydrocarbons (PAH) from a residential catchment (228 ha) in the Paris region. In this application, we suggest several procedures that can be applied for the analysis of other pollutants in different catchments, including an estimation of the total extent of roof accessories (gutters and downspouts, watertight joints and valleys) in a catchment. These accessories result as the major source of Pb and as an important source of Zn in the example catchment, while activity-related sources (traffic, heating) are dominant for Cu (brake pad wear) and PAH (tire wear, atmospheric deposition). PMID:24760596

  1. SIMULATION COASTAL PLAIN STREAM FISH COMMUNITY RESPONSE TO NONPOINT SOURCE POLLUTION USING LINKED HYDROLOGIC-ECOLOGICAL MODELS

    EPA Science Inventory

    Nonpoint source pollution is the primary stress in many streams. Characteristic declines in stream fish communities are recognized in streams influenced by nonpoint source pollution, but the processes by which these declines occur are not well understood. Here, predicted time s...

  2. Analysis of lake-bottom sediment to estimate historical nonpoint-source phosphorus loads

    USGS Publications Warehouse

    Juracek, K.E.

    1998-01-01

    Bottom sediment in Hillsdale Lake, Kansas, was analyzed to estimate the annual load of total phosphorus deposited in the lake from nonpoint sources. Topographic, bathymetric, and sediment-core data were used to estimate the total mass of phosphorus in the lake-bottom sediment. Available streamflow and water-quality data were used to compute the mean annual mass of phosphorus (dissolved plus suspended) exiting the lake. The mean annual load of phosphorus added to the lake from point sources was estimated from previous studies. A simple mass balance then was used to compute the mean annual load of phosphorus from nonpoint sources. The total mass of phosphorus in the lake-bottom sediment was estimated to be 924,000 kg, with a mean annual load of 62,000 kg. The mean annual mass of phosphorus exiting in the lake outflow was estimated to be about 8,000 kg. The mean annual loads of phosphorus added to the lake from point and nonpoint sources were estimated to be 5,000 and 65,000 kg, respectively. Thus, the contribution to the total mean annual phosphorus load in Hillsdale Lake is about 7 percent from point sources and about 93 percent from nonpoint sources.

  3. Study of the distribution of non-point source pollution in the watershed of the Miyun Reservoir, Beijing, China.

    PubMed

    Wang, X; Li, T; Xu, A; He, W

    2001-01-01

    Nitrogen and phosphorus are major nutrients to cause eutrophication to degrade the water quality of the Miyun Reservoir, a very important drinking water source of Beijing in China. These are mainly from non-point sources. The watershed in Miyun County is selected as the study region with a total area of 1400 km2. Four typical monitoring catchments and two experimental units were used to monitor the precipitation, runoff, sediment yield and pollutant loading related to various land uses in the meantime. The results show that the total nutrient loss amount of TN and TP is 898.07 t/a, and 40.70 t/a, respectively, in which nutrient N and P carried by runoff is 91.3% and 77.3%, respectively. There is relatively heavier soil erosion at the northern mountain area whereas the main nutrient loss occurs near the northeast rim of the reservoir. Different land uses influence the loss of non-point source pollutants. The amount of nutrient loss from agricultural land per unit is the highest, nutrient loss from forestry is the second highest and that from grassland is the lowest. However, due to the variability of land use areas, agricultural land contributes the greatest amount of TP and forestry lands the greatest amount of TN. PMID:11724492

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

    PubMed

    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. PMID:26724699

  5. U. S. EPA Nonpoint-Source Information Exchange Computer Bulletin Board System (BBS). User's manual

    SciTech Connect

    Not Available

    1992-01-01

    The Nonpoint Source (NPS) Information Exchange Bulletin Board System (BBS) will provide state and local agencies, private organizations, businesses, and concerned individuals with timely, relevant NPS information, a forum for open discussion, and the ability to exchange computer text and program files.

  6. EVALUATING POINT-NONPOINT SOURCE WATER QUALITY TRADING IN A RARITAN RIVER BASIN SUB-WATERSHED

    EPA Science Inventory

    This project addresses water quality issues in the Raritan River Basin of New Jersey. It will build upon an existing study that determined the technical feasibility of implementing a point-nonpoint source water quality trading program in the Basin. Water quality trading is ...

  7. An assessment of nonpoint-source discharges, streamflow, and water quality in Onion River, Wisconsin

    USGS Publications Warehouse

    Field, S.J.; Lidwin, R.A.

    1984-01-01

    Nutrient yields and loading rates were highest downstream of Hingham. Nonpoint-source contribution of phosphorus amounted to 362 pounds per square mile downstream of Hingham compared to 272 pounds per square mile upstream of Hingham in the 19

  8. BEST MANAGEMENT PRACTICES FOR THE CONTROL OF NUTRIENTS FROM URBAN NONPOINT SOURCES

    EPA Science Inventory

    While the costs and benefits associated with the point source control of nutrients are relatively well defined, considerable uncertainties remain in the efficiency and long-term costs associated with the best management practices (BMPs) used to redcuce loads from nonpoint and dif...

  9. BOOK REVIEW OF "ASSESSMENT AND CONTROL OF NONPOINT SOURCE POLLUTION OF AQUATIC ECOSYSTEMS: A PRACTICAL APPROACH"

    EPA Science Inventory

    This book is geared to environmental specialists and planners, heavy on the technical side. It goes beyond tranditional nonpoint source (NPS) approaches which typically only look at stormwater as athe sole NPS pollution driver. There is some overreaching material beyond the conte...

  10. HYDROLOGY AND SEDIMENT MODELING USING THE BASINS NON-POINT SOURCE MODEL

    EPA Science Inventory

    The Non-Point Source Model (Hydrologic Simulation Program-Fortran, or HSPF) within the EPA Office of Water's BASINS watershed modeling system was used to simulate streamflow and total suspended solids within Contentnea Creek, North Carolina, which is a tributary of the Neuse Rive...

  11. Simulation of Urban Runoff Non-point Source Pollution Load and Analysis on Its Influencing Factors

    NASA Astrophysics Data System (ADS)

    Li, R.; Ruan, X.

    2013-12-01

    As the point source pollution control has advanced, the proportion of urban non-point pollution caused by rainfall in urban water pollution is increasing. For quantitative evaluation of non-point source pollution in urban rivers and to study their influencing factors, this study takes the inner Qinhuai River in Nanjing as the study area. The non-point source pollution load simulation model of the study area was built based on the Storm Water Management Model (SWMM), and was calibrated using the real-time monitoring data of rainfall and the outlet of the pipes during a short duration rainfall in 2011. TSS, CODMn, TN and TP were selected as the major pollution load indicators to quantitatively assess the rainfall runoff and non-point source pollution of 328.2ha confluence area of inner Qinhuai River, emphatically probe into the variation of the rainfall runoff and non-point source pollution in response to variability in underlying surface and drainage pipes. The results show that: (1) the pollution load concentration in the outlet of the popes increases initially and then decreases, the peak concentration appears at 5~15minutes after the effluent. The concentration of TN and TP appears apparent randomness and fluctuation due to the spatial-temporal uncertainty of the distribution of the non-point source pollution. The maximum flow into the river, the total runoff, the total output of TSS, CODMn, TN and TP during a typical year rainfall in two years return period are 19.67m3/s, 81.74×103m3, 2318.59kg, 1598.08kg, 476.09kg and 24.24kg, respectively. (2)The percentage of impervious underlying surface, the slope of the underlying surface, the percentage of no depression of the impervious underlying surface and the roughness of the pipes, which are the sensitive parameters of the model, have an significant impact on the runoff and pollution load in the outlet of the pipes. Urban rainfall runoff and non-point source pollution can be reduced by reducing the percentage of

  12. NON-POINT SOURCE--STREAM NUTRIENT LEVEL RELATIONSHIPS: A NATIONWIDE STUDY. SUPPLEMENT 1: NUTRIENT MAP RELIABILITY

    EPA Science Inventory

    The National Eutrophication Survey (NES) national maps of non-point source nitrogen and phosphorus concentrations in streams were evaluated for applicability and reliability. Interpretations on these maps which were based on data from 928 sampling sites associated with non-point ...

  13. Reduction of nonpoint source contamination of surface water and groundwater by starch encapsulation of herbicides

    USGS Publications Warehouse

    Mills, M.S.; Thurman, E.M.

    1994-01-01

    The loss of the preemergent herbicide atrazine in surface runoff from experimental field plots growing corn (Zea mays L.) was significantly reduced using a starchencapsulated formulation versus a conventional powdered formulation. Field edge losses of starch-encapsulated atrazine were described as following a Rayleigh distribution totaling 1.8% of applied herbicide compared to exponential powdered atrazine losses of 2.9% applied - a 40% decrease. This has important implications for the reduction of nonpoint source contamination of surface water by agricultural chemicals. Unsaturated zone release of starchencapsulated atrazine was gradual, but comparable weed control was maintained. Deethylatrazine was a major dealkylated metabolite from each formulation, and deisopropylatrazine was a minor metabolite. The determination of soil partition coefficients for deethylatrazine and deisopropylatrazine (0.4 and 0.3, respectively), aqueous solubilities (3200 and 670 mg/L, respectively), and melting points (133 and 177 ??C, respectively) confirmed that the dealkylated metabolites should move more rapidly through the soil profile to groundwater than atrazine.

  14. Vertical Variation of Nonpoint Source Pollutants in the Three Gorges Reservoir Region

    PubMed Central

    Shen, Zhenyao; Chen, Lei; Hong, Qian; Xie, Hui; Qiu, Jiali; Liu, Ruimin

    2013-01-01

    Nonpoint source (NPS) pollution is considered the main reason for water deterioration, but there has been no attempt to incorporate vertical variations of NPS pollution into watershed management, especially in mountainous areas. In this study, the vertical variations of pollutant yields were explored in the Three Gorges Reservoir Region (TGRR) and the relationships between topographic attributes and pollutant yields were established. Based on our results, the pollutant yields decreased significantly from low altitude to median altitude and leveled off rapidly from median altitude to high altitude, indicating logarithmic relationships between pollutant yields and altitudes. The pollutant yields peaked at an altitude of 200–500 m, where agricultural land and gentle slopes (0–8°) are concentrated. Unlike the horizontal distributions, these vertical variations were not always related to precipitation patterns but did vary obviously with land uses and slopes. This paper also indicates that altitude data and proportions of land use could be a reliable estimate of NPS yields at different altitudes, with significant implications for land use planning and watershed management. PMID:23951110

  15. Soil erosion and non-point source pollution impacts assessment with the aid of multi-temporal remote sensing images.

    PubMed

    Ning, Shu-Kuang; Chang, Ni-Bin; Jeng, Kai-Yu; Tseng, Yi-Hsing

    2006-04-01

    Soil erosion associated with non-point source pollution is viewed as a process of land degradation in many terrestrial environments. Careful monitoring and assessment of land use variations with different temporal and spatial scales would reveal a fluctuating interface, punctuated by changes in rainfall and runoff, movement of people, perturbation from environmental disasters, and shifts in agricultural activities and cropping patterns. The use of multi-temporal remote sensing images in support of environmental modeling analysis in a geographic information system (GIS) environment leading to identification of a variety of long-term interactions between land, resources, and the built environment has been a highly promising approach in recent years. This paper started with a series of supervised land use classifications, using SPOT satellite imagery as a means, in the Kao-Ping River Basin, South Taiwan. Then, it was designed to differentiate the variations of eight land use patterns in the past decade, including orchard, farmland, sugarcane field, forest, grassland, barren, community, and water body. Final accuracy was confirmed based on interpretation of available aerial photographs and global positioning system (GPS) measurements. Finally, a numerical simulation model (General Watershed Loading Function, GWLF) was used to relate soil erosion to non-point source pollution impacts in the coupled land and river water systems. Research findings indicate that while the decadal increase in orchards poses a significant threat to water quality, the continual decrease in forested land exhibits a potential impact on water quality management. Non-point source pollution, contributing to part of the downstream water quality deterioration of the Kao-Ping River system in the last decade, has resulted in an irreversible impact on land integrity from a long-term perspective. PMID:16182435

  16. Three studies using Ceriodaphnia to detect nonpoint sources of metals from mine drainage

    USGS Publications Warehouse

    Nimmo, Del Wayne R.; Dodson, Max H.; Davies, Patrick H.; Greene, Joseph C.; Kerr, Mark A.

    1990-01-01

    Since its introduction, Ceriodaphnia dubia, a small planktonic daphnid, has been widely used for biomonitoring point source discharges. This species was also used to determine nonpoint sources of metals and related contaminants in three trout streams in the west where mining activities have been widespread. Along Chalk Creek, Colo., specific tailings (and impacted tributaries) were sources of metals toxic to fish using the water in a hatchery. At stations below extensive mine tailings in the upper Clark Fork River, Mont., drainage was acutely and chronically toxic to daphnids and paralleled reduced or nonexistent populations of trout. In Whitewood Creek, S. Dak., reduced toxicity below a gold mine portended that fish could live in the stream segment previously impaired by the mine. Toxicity downstream revealed a previously unknown nonpoint source of chromium.

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

    USGS Publications Warehouse

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

    1989-01-01

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

  18. Continuous 'Passive' Registration of Non-Point Contaminant Loads Via Agricultural Subsurface Drain Tubes

    NASA Astrophysics Data System (ADS)

    Rozemeijer, J.; Jansen, S.; de Jonge, H.; Lindblad Vendelboe, A.

    2014-12-01

    Considering their crucial role in water and solute transport, enhanced monitoring and modeling of agricultural subsurface tube drain systems is important for adequate water quality management. For example, previous work in lowland agricultural catchments has shown that subsurface tube drain effluent contributed up to 80% of the annual discharge and 90-92% of the annual NO3 loads from agricultural fields towards the surface water. However, existing monitoring techniques for flow and contaminant loads from tube drains are expensive and labor-intensive. Therefore, despite the unambiguous relevance of this transport route, tube drain monitoring data are scarce. The presented study aimed developing a cheap, simple, and robust method to monitor loads from tube drains. We are now ready to introduce the Flowcap that can be attached to the outlet of tube drains and is capable of registering total flow, contaminant loads, and flow-averaged concentrations. The Flowcap builds on the existing SorbiCells, a modern passive sampling technique that measures average concentrations over longer periods of time (days to months) for various substances. By mounting SorbiCells in our Flowcap, a flow-proportional part of the drain effluent is sampled from the main stream. Laboratory testing yielded good linear relations (R-squared of 0.98) between drainage flow rates and sampling rates. The Flowcap was tested in practice for measuring NO3 loads from two agricultural fields and one glasshouse in the Netherlands. The Flowcap registers contaminant loads from tube drains without any need for housing, electricity, or maintenance. This enables large-scale monitoring of non-point contaminant loads via tube drains, which would facilitate the improvement of contaminant transport models and would yield valuable information for the selection and evaluation of mitigation options to improve water quality.

  19. Watershed Characteristics and Land Management in the Nonpoint-Source Evaluation Monitoring Watersheds in Wisconsin

    USGS Publications Warehouse

    Rappold, K.F.; Wierl, J.A.; Amerson, F.U.

    1997-01-01

    In 1992, the Wisconsin Department of Natural Resources, in cooperation with the U.S. Geological Survey, began a land-use inventory to identify sources of contaminants and track the land-management changes for eight evaluation monitoring watersheds in Wisconsin. An important component of the land-use inventory has been developing descriptions and preliminary assessments for the eight watersheds. These descriptions establish a baseline for future data analysis. The watershed descriptions include sections on location, reference watersheds, climate, land use, soils and topography, and surface-water resources. The land-management descriptions include sections on objectives, sources of nonpoint contamination and goals of contaminant reduction, and implementation of best-management practices. This information was compiled primarily from the nonpoint-source control plans, county soil surveys, farm conservation plans, Federal and State agency data reports, and data collected through the land-use inventory.

  20. A GIS-based study on non-point source pollutant distribution around Miyun Reservoir Watershed, Beijing, China

    NASA Astrophysics Data System (ADS)

    Wang, X.; wang, y; cai, x; wang, x

    2001-12-01

    Nitrogen and phosphorus, coming mainly from non-point sources (NPS), are major nutrients to cause eutrophication to degrade water quality of Miyun Reservoir, the only one surface drinking water source of Beijing, China. The spatial nature of the NPS pollution problem necessitates the use of a geographic information system (GIS) to manipulate, retrieve, and display the large volumes of spatial data. Based on the relevant data which range from meteorological and hydrological data to land use, fertilizer and pesticide usage, and even livestock raising information, the database of NPS of Shixia Catchment in Miyun Reservoir watershed were established. Using GIS, abstracting attribute data, digitizing, editing, coordinate transferring and generating the digital elevation model (DEM) could be finished. A total of four land use scenarios were modeled to evaluate various land management strategies on sediment and nutrient loading from catchment. The results suggest that high nutrient loads are associated with village, which has unsuitable livestock raising. Different land use influences intensively the loss of pollutants, especially slope tilling in agricultural land. The amount of nutrient loss from the agricultural land per unit is the highest, that from forestry is the secondary and that from grassland is the lowest. However, due to the variability of land use areas, agricultural land contributes the greatest effort to TP and forestry lands to TN. The loss amount of pollutant in flood season is nearly 60% of annual loss amount. The amount of nutrient loss from hill areas is larger than that from mountain areas. Pattern of non-point source pollution in Miyun County is showed that near the north and east boundary of the Reservoir is the heaviest area. It is indicated that nutrient loss is correlated with people density, fertilizer usage and soil erosion.

  1. Evaluation of Nonpoint Source Pollution in Stormwater Run-Off in Neighborhoods in San Francisco, California

    NASA Astrophysics Data System (ADS)

    Bailey, C.; Bailey, E.; Cai, W.; Chen, K.; Duario, D.; Gonzalez, S.; Li, A.; Liu, L. W.; Matic, M.; Wu, M. L.; Wu, X. P.; Xie, J.; Yue, J.; Yuen, K.; Kirwin, J. P.; Neiss, J.

    2007-12-01

    This is the San Francisco Bay watershed encompasses 40% of California. When precipitation occurs, nonpoint source pollutants such as fertilizers, heavy metals, pesticides, gas and oil, enter the San Francisco Bay through this watershed. These pollutants contain dangerous chemicals that can potentially impact people and local ecology. The goal of Project Watershed is for high school students to design a study that investigates nonpoint source pollution in their own neighborhood and correlate these findings to the human activity in the neighborhood. Fifteen high school students participating in this study designed a stormwater collection devise that was installed in the public storm drain near each students home. Stormwater samples where collected from each device during the period of December 2006 to April 2007. Students assessed the samples for nitrates, heavy metals, oil and grease, total petroleum hydrocarbons, toluene and methyl tert-butyl ether (MTBE). This study outlines the methods students used to design the study and a summary of results found.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Nonpoint-source nitrogen and phosphorus behavior and modeling in cold climate: a review.

    PubMed

    Han, Cheng-Wei; Xu, Shi-Guo; Liu, Jian-Wei; Lian, Jian-Jun

    2010-01-01

    Pollution from nonpoint-source (NPS) nitrogen (N) and phosphorus (P) are the main causes of eutrophication in lotic, lentic and coastal systems. The climate of cold regions might play an important role in disturbing environmental behavior of NPS N and P, influencing simulation of watershed scale hydrologic and nonpoint-source pollution models. The losses of NPS N and P increase in regions of cold climate. In cold seasons, accumulations of N and P are accelerated in soil with increasing fine root and aboveground biomass mortality, decreasing plant nutrient uptake, as well as freezing soil. N and P transformation is disturbed by soil frost and snow. Moreover, factors such as physical disruption of soil aggregates, pollutant accumulation in snowpack, and snow melting can all increase the NPS N and P losses to the waterbody. Therefore, NPS N and P in first flush are more serious in cold climate. All these effects, especially frozen soil and snowpack, make great challenges to watershed scale hydrologic and nonpoint-source pollution models simulation in cold climate. Model improvements of snowmelt runoff, nutrient losses in frozen soil, as well as N and P behavior have been initiated and will be continued to evaluate in terms of their performances and suitability with different scale, hydrologic and geologic conditions in the future. PMID:21076213

  4. A Probabilistic Approach for Analysis of Modeling Uncertainties in Quantification of Trading Ratios in Nonpoint to Point Source Nutrient Trading Programs

    NASA Astrophysics Data System (ADS)

    Tasdighi, A.; Arabi, M.

    2015-12-01

    Quantifying the nonpoint source pollutant loads and assessing the water quality benefits of conservation practices (BMPs) are prone to different types of uncertainties which have to be taken into account when developing nutrient trading programs. Although various types of modeling uncertainties (parameter, input and structure) have been examined in the literature more or less, the impact of modeling uncertainties on evaluation of BMPs has not been addressed sufficiently. Currently, "trading ratios" are used within nutrient trading programs to account for variability of nonpoint source loads. However, we were not able to find any case of some rigorous scientific approach to account for any type of uncertainties in trading ratios. In this study, Bayesian inferences were applied to incorporate input, parameter and structural uncertainties using a statistically valid likelihood function. IPEAT (Integrated Parameter Estimation and Uncertainty Analysis Tool), a framework developed for simultaneous evaluation of parameterization, input data, model structure, and observation data uncertainty and their contribution to predictive uncertainty was used to quantify the uncertainties in effectiveness of agricultural BMPs while propagating different sources of uncertainty. SWAT was used as the simulation model. SWAT parameterization was done for three different model structures (SCS CN I, SCS CN II and G&A methods) using a Bayesian based Markov Chain Monte Carlo (MCMC) method named Differential Evolution Adaptive Metropolis (DREAM). For each model structure, the Integrated Bayesian Uncertainty Estimator (IBUNE) was employed to generate latent variables from input data. Bayesian Model Averaging (BMA) was then used to combine the models and Expectation-Maximization (EM) optimization technique was used to estimate the BMA weights. Using this framework, the impact of different sources of uncertainty on nutrient loads from nonpoint sources and subsequently effectiveness of BMPs in

  5. Stochastic Assessment of Regional Groundwater Nonpoint Source Pollution with Spatially Variable, Transient Forcing: Conceptual Framework and Nitrate Case Study

    NASA Astrophysics Data System (ADS)

    Harter, T.; van der Schans, M. L.; Leijnse, A.

    2003-12-01

    We introduce a general stochastic concept of regional groundwater nonpoint source pollution in production wells or other groundwater discharge areas; present an efficient numerical procedure for its implementation; and validate the approach using a case study. Our principal hypothesis is that regional variability of and uncertainty about well pollution from nonpoint sources is primarily caused by the spatio-temporal variability of the nonpoint source strength (recharge rate and recharge pollutant concentration) and the variable spatial distribution of pumping wells, pumping rates, and other groundwater discharge relative to the location of the nonpoint sources. We describe a conceptual model of random space functions (RSFs) for nonpoint sources and wells. The resulting stochastic flow and transport equations are subject to random forcing in the nonpoint source and pumping boundary conditions (external variability). The stochastic forcing analysis yields a transient probability distribution function of water quality (water quality pdf) in a regional set of randomly distributed, discrete production wells and other groundwater discharge areas. We introduce a novel three-step numerical approach for the stochastic forcing analysis and apply the method to determine the 150-year (1910-2060) nitrate pdf for an irrigated, semi-arid region with a history of high groundwater nitrate. Comparison of the simulated nitrate pdfs with results from regional and domestic well water surveys in 1970, 1986 and 2001 shows that stochastic forcing indeed accounts for the observed temporal nitrate dynamics (mean concentration) and for 70% of the spatial variability observed in domestic well water nitrate in that region.

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

    PubMed

    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. PMID:26936476

  7. An inexact fuzzy two-stage stochastic model for quantifying the efficiency of nonpoint source effluent trading under uncertainty.

    PubMed

    Luo, B; Maqsood, I; Huang, G H; Yin, Y Y; Han, D J

    2005-07-15

    Reduction of nonpoint source (NPS) pollution from agricultural lands is a major concern in most countries. One method to reduce NPS pollution is through land retirement programs. This method, however, may result in enormous economic costs especially when large sums of croplands need to be retired. To reduce the cost, effluent trading can be employed to couple with land retirement programs. However, the trading efforts can also become inefficient due to various uncertainties existing in stochastic, interval, and fuzzy formats in agricultural systems. Thus, it is desired to develop improved methods to effectively quantify the efficiency of potential trading efforts by considering those uncertainties. In this respect, this paper presents an inexact fuzzy two-stage stochastic programming model to tackle such problems. The proposed model can facilitate decision-making to implement trading efforts for agricultural NPS pollution reduction through land retirement programs. The applicability of the model is demonstrated through a hypothetical effluent trading program within a subcatchment of the Lake Tai Basin in China. The study results indicate that the efficiency of the trading program is significantly influenced by precipitation amount, agricultural activities, and level of discharge limits of pollutants. The results also show that the trading program will be more effective for low precipitation years and with stricter discharge limits. PMID:16084964

  8. Point and non-point microbial source pollution: A case study of Delhi

    NASA Astrophysics Data System (ADS)

    Jamwal, Priyanka; Mittal, Atul K.; Mouchel, Jean-Marie

    The present study identifies major point and non-point sources of microbial pollution during dry and wet weather in Delhi watershed which is the first prerequisite for planning and management of water quality of the river Yamuna. Fecal coliforms (FC) and fecal streptococci (FS) levels were determined from two types of sources - point source (effluent from sewage treatment plants) and non-point source (stormwater runoff during dry and wet weather). FC and FS levels in the river Yamuna were also monitored, which is an ultimate sink for all microbial loads in Delhi watershed. Effluent from sewage treatment plants (STPs) employing different treatment technologies were evaluated. FC and FS levels greater than the effluent discharge standard (1000 MPN/100 ml) were observed in the effluents from all STPs except “oxidation pond Timarpur”. This study also involved field program for characterization of urban runoff from different land-uses. Results indicated that the microbial quality of urban runoff produced during wet weather from different land-uses was similar to that of raw sewage. Sewage overflows along with human and animal sources were responsible for high FC and FS levels in the runoff samples. Wet weather FC and FS levels in river Yamuna were higher as compared to the dry weather levels suggesting that dilution of the river water during wet weather does not affect its microbiological quality. Thus on the basis of this study it was found that urban runoff also contributes to the microbial quality of the river Yamuna.

  9. An Experimental Study on Using Rare Earth Elements to Trace Non-point source Phosphorous LossA

    NASA Astrophysics Data System (ADS)

    Liang, T.

    2011-12-01

    Controlling phosphorous (P) inputs through management of its sources and transport is critical for limiting freshwater eutrophication. Rare earth elements (REEs) have been successfully used in the analysis of soil erosion and pollutant sources, as well as in the analysis of mineral genesis. To better understand the potential for REE use in tracing non-point sources of P, we examined the combined fate of REEs and P in Chinese soils amended with REEs and documented the formation of REE-P compounds. Laboratory leaching experiments and artificial simulated rainfall experiments were conducted. Vertical leaching transfers of REEs and P were relatively small, with transport depths less than 6 cm for most REEs and P. Export of applied REEs in leachate accounted for less that 5% of inputs. The vertical mobility order of REEs and P in Chinese soils was greatest for purple soil, followed by terra nera soil, then red soil, followed by cinnamon soil, and finally loess soil. Losses of rare earth elements and P in surface runoff exhibited a parabolic relationship to simulated rainfall intensity. With greater exogenous La application, the amount of water soluble P, bicarbonate-extractable P and hydroxide-extractable P decreased significantly, while acid-extractable and residual forms of P increased significantly. In addition, characteristics of exogenous rare earth elements (REEs) and P and their losses with surface runoff (both in the water and sediments) during simulated rainfall experiments (83 mm h-1) were investigated. The results revealed that most REEs (La, 94%; Nd, 93%; Sm, 96%) and P (96%) transported with sediments in the runoff. The total amounts of losses of REEs and P in the runoff were significantly correlated, suggesting the possibility of using REEs to trace the fate of agricultural nonpoint P losses.

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

    NASA Astrophysics Data System (ADS)

    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

  11. Groundwater as a nonpoint source of atrazine and deethylatrazine in a river during base flow conditions

    USGS Publications Warehouse

    Squillace, Paul J.; Thurman, E.M.; Furlong, Edward T.

    1993-01-01

    Alluvial groundwater adjacent to the main stem river is the principal nonpoint source of atrazine and deethylatrazine in the Cedar River of Iowa after the river has been in base flow conditions for 5 days. Between two sites along a 116-km reach of the Cedar River, tributaries contributed about 25% of the increase in the atrazine and deethylatrazine load, whereas groundwater from the alluvial aquifer contributed at least 75% of the increase in load. Within the study area, tributaries aggregate almost all of the discharge from tile drains, and yet the tributaries still only contribute 25% of the increase in loads in the main stem river. At an unfamned study site adjacent to the Cedar River, the sources of atrazine and deethylatrazine in the alluvial groundwater are bank storage of river water and groundwater recharge from areas distant from the river. Atrazine and deethylatrazine associated with bank storage water will provide larger concentrations to the river during early base flow conditions. After the depletion of bank storage, stable and smaller concentrations of atrazine and deethylatrazine, originating from groundwater recharge, continue to be discharged from the alluvial aquifer to the river; thus these results indicate that alluvial aquifers are an important nonpoint source of atrazine and deethylatrazine in rivers during base flow.

  12. A robust simulation-optimization modeling system for effluent trading--a case study of nonpoint source pollution control.

    PubMed

    Zhang, J L; Li, Y P; Huang, G H

    2014-04-01

    In this study, a robust simulation-optimization modeling system (RSOMS) is developed for supporting agricultural nonpoint source (NPS) effluent trading planning. The RSOMS can enhance effluent trading through incorporation of a distributed simulation model and an optimization model within its framework. The modeling system not only can handle uncertainties expressed as probability density functions and interval values but also deal with the variability of the second-stage costs that are above the expected level as well as capture the notion of risk under high-variability situations. A case study is conducted for mitigating agricultural NPS pollution with an effluent trading program in Xiangxi watershed. Compared with non-trading policy, trading scheme can successfully mitigate agricultural NPS pollution with an increased system benefit. Through trading scheme, [213.7, 288.8] × 10(3) kg of TN and [11.8, 30.2] × 10(3) kg of TP emissions from cropped area can be cut down during the planning horizon. The results can help identify desired effluent trading schemes for water quality management with the tradeoff between the system benefit and reliability being balanced and risk aversion being considered. PMID:24366827

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

    USGS Publications Warehouse

    Bernknopf, Richard L.; Forney, William M.; Raunikar, Ronald P.; Mishra, Shruti 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.

  14. Atmospheric deposition of selected chemicals and their effect on nonpoint-source pollution in the Twin Cities Metropolitan Area, Minnesota

    USGS Publications Warehouse

    Brown, R.G.

    1984-01-01

    The atmospheric contribution to nonpoint-source-runoff pollution of nitrogen, in the form of nitrite-plus-nitrate, and lead was extremely high contributing as much as 84 percent of the runoff load. In contrast, phosphorus and chloride inputs were low averaging of 6 percent of the total runoff load. Future investigations of nonpoint-source pollution in runoff might include collection of data on atmospheric deposition of nitrite-plus-nitrate nitrogen and lead because of the importance of that source of these constituents in runoff.

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

    PubMed

    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. PMID:21093255

  16. Assessment of Non-Point Source Pollution in the Vadose Zone

    NASA Astrophysics Data System (ADS)

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

    Non-point source (NPS) pollution in the vadose zone (simply defined as the layer of soil extending from the soil surface to the groundwater table) is a global environmental problem. Characteristically, NPS pollutants are widespread and occasionally ubiquitous in extent, thus making remediation efforts difficult and complex; have the potential for maintaining a relatively long active presence in the global ecosystem; and may result in long-term, chronic health effects in humans and other life forms. Similar to other global environmental issues, the knowledge and information required to address the problem of NPS pollutants in the vadose zone cross several technological and subdisciplinary lines: spatial statistics, geographic information systems (GIS), hydrology, soil science, and remote sensing. Cooperation between disciplines and scientific societies is essential to address the problem. Evidence of such cooperation was the jointly sponsored American Geophysical Union Chapman/Soil Science Society of America (SSSA) Outreach Conference that occurred in October 1997, entitled "Applications of GIS, Remote Sensing, Geostatistics, and Solute Transport Modeling to the Assessment of Non-Point Source Pollution in the Vadose Zone." The objective of the conference and this book, which was developed from the conference, was to explore current multidisciplinary research for assessing NPS pollution in soil and groundwater resources.

  17. Integrated watershed economic model for non-point source pollution management in Upper Big Walnut Creek Watershed, OH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Today, non-point source pollution (NPS) is one of the major sources of water quality impairments globally (UNEP, 2007). In the US, nutrient pollution is the leading cause of water quality issues in lakes and estuaries (USEPA, 2002). The maximum concentration of nutrients in streams is found to be in...

  18. Non-point pollution of groundwater from agricultural activities in Mediterranean Spain: the Balearic Islands case study

    NASA Astrophysics Data System (ADS)

    Candela, L.; Wallis, K. J.; Mateos, R. M.

    2008-04-01

    Mediterranean Spain is a region with intensive agricultural production combined with an important seasonal water demand for water supply. High application rates of inorganic nitrogen fertiliser, input of plant protection products and intensive irrigation, sometimes with treated wastewater, is a common practice. As a result, most aquifers show nitrate contamination problems of agricultural origin. Data on pesticide residues is scarce, as systematic monitoring is not currently done. In Majorca Island, values up to 700 mg/l of nitrate in groundwater have been observed. To analyse the current situation derived from non-point pollution, several actions have been taken at different scales: declaration of a nitrate vulnerable zone, field experiments to evaluate nitrogen transport to the aquifer and the development of a GIS-simulation model to generate nitrate risk maps.

  19. Effectiveness of a constructed wetland for retention of nonpoint-source pesticide pollution in the Lourens River catchment, South Africa.

    PubMed

    Schulz, R; Peall, S K

    2001-01-15

    Constructed wetlands have been widely used to control both point- and nonpoint-source pollution in surface waters. However, our knowledge about their effectiveness in retaining agricultural pesticide pollution is limited. A 0.44-ha vegetated wetland built along a tributary of the Lourens River, Western Cape, South Africa, was studied to ascertain retention of runoff-related agricultural pollution. Total suspended solids, orthophosphate, and nitrate were retained in the wetland in the proportions 15, 54, and 70%, respectively, during dry weather conditions (with rainfall less than 2 mm/d) and 78, 75, and 84% during wet conditions (with rainfall between 2 and 35 mm/d). Retention of water-diluted azinphos-methyl introduced via runoff at a level of 0.85 microg/L was between 77 and 93%. Chlorpyrifos and endosulfan were measured during runoff in inlet water at 0.02 and 0.2 microg/L, respectively. However, both pesticides were undetectable in the outlet water samples. During a period of 5 months, an increased concentration of various insecticides was detected in the suspended particles at the wetland inlet: azinphos-methyl, 43 microg/kg; chlorpyrifos, 31 microg/kg; and prothiofos, 6 microg/kg. No organophosphorus pesticides were found in the outlet suspended-particle samples, highlighting the retention capability of the wetland. A toxicological evaluation employing a Chironomus bioassay in situ at the wetland inlet and outlet revealed an 89% reduction in toxicity below the wetland during runoff. PMID:11347620

  20. Analysis of bottom sediment to estimate nonpoint-source phosphorus loads for 1981-96 in Hillsdale Lake, northeast Kansas

    USGS Publications Warehouse

    Juracek, K.E.

    1997-01-01

    Bottom sediment in Hillsdale Lake, northeast Kansas, was analyzed as a means of estimating the annual load of total phosphorus deposited in the lake from nonpoint sources. Topographic, bathymetric, and sediment-core data were used to estimate the total mass of phosphorus in the lake-bottom sediment. Available streamflow and water-quality data were used to compute the mean annual mass of phosphorus (dissolved plus suspended) exiting the lake as well as the mean annual load of phosphorus added to the lake from point sources. A simple mass balance then was used to compute the mean annual load of phosphorus from nonpoint sources. Mean annual sediment deposition from 1981 through 1996 was estimated to be 265 million pounds (120 million kilograms). The total mass of phosphorus in the lake-bottom sediment was estimated to be 924,000 kilograms, with a mean annual load of 62,000 kilograms. The mean annual mass of phosphorus exiting in the lake out-flow was estimated to be about 8,000 kilograms. The mean annual loads of phosphorus added to the lake from point and nonpoint sources were estimated to be 5,000 and 65,000 kilograms, respectively. Thus, the contribution to the total mean annual phosphorus load in Hillsdale Lake from point sources is about 7 percent and from nonpoint sources, about 93 percent.

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

    USGS Publications Warehouse

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Multi-angle indicators system of non-point pollution source assessment in rural areas: a case study near Taihu Lake.

    PubMed

    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. PMID:23456193

  4. RIVER BASIN VALIDATION OF THE WATER QUALITY ASSESSMENT METHODOLOGY FOR SCREENING NONDESIGNATED 208 AREAS. VOLUME I: NONPOINT SOURCE LOAD ESTIMATION

    EPA Science Inventory

    In earlier work under the sponsorship of EPA, loading functions were developed by Midwest Research Institute (MRI) for estimating the quantities of different diffuse loads entering receiving waters from nonpoint sources and a screening methodology was produced by Tetra Tech, Inc....

  5. ASSESSING NON-POINT SOURCES OF NITROGEN TO SMALL STREAMS IN THE SOUTH FORK BROAD RIVER WATERSHED (GEORGIA, USA)

    EPA Science Inventory

    The National Land Cover Data (NLCD) is a land cover classification derived from Landsat Thematic Mapper satellite data collected in the early to mid-1990s. In this work, land use coverages calculated from the NLCD database are used to assess the impact of non-point sources on the...

  6. Metabolomics for in situ environmental monitoring of surface waters impacted by contaminants from both point and non-point sources

    EPA Science Inventory

    We investigated the efficacy of metabolomics for field-monitoring of fish exposed to waste water treatment plant (WWTP) effluents and non-point sources of chemical contamination. Lab-reared male fathead minnows (Pimephales promelas, FHM) were held in mobile monitoring units and e...

  7. Point- and nonpoint-source trace elements in a wild and scenic river of northern New Mexico.

    USGS Publications Warehouse

    Garn, H.S.

    1985-01-01

    Variations in water quality of the upper Rio Grande and Red River are presented. A downstream increase in concentrations of various constituents, at times approaching or exceeding water quality standards, occurred due to leaching of natural ore bodies and permitted discharges from molybdenum mill tailings ponds. Nonpoint sources are a major cause of elevated trace element concentrations.-from Author

  8. MODELING THE DISTRIBUTION OF NONPOINT NITROGEN SOURCES AND SINKS IN THE NEUSE RIVER BASIN OF NORTH CAROLINA, USA

    EPA Science Inventory

    This study quantified nonpoint nitrogen (N) sources and sinks across the 14,582 km2 Neuse River Basin (NRB) located in North Carolina, to provide a tabular database to initialize in-stream N decay models and graphic overlay products for the development of management approaches to...

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    Chen, Lei; Wei, Guoyuan; Shen, Zhenyao

    2015-10-01

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

  11. Simulation of spatial and temporal distributions of non-point source pollution load in the Three Gorges Reservoir Region.

    PubMed

    Shen, Zhenyao; Qiu, Jiali; Hong, Qian; Chen, Lei

    2014-09-15

    Non-point source (NPS) pollution has become the largest threat to water quality in recent years. Major pollutants, particularly from agricultural activities, which include nitrogen, phosphorus and sediment that have been released into aquatic environments, have caused a range of problems in the Three Gorges Reservoir Region (TGRR), China. 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 study, the NPS pollutant load was simulated using the Soil and Water Assessment Tool (SWAT) and the small-scale watershed extended method (SWEM). The simulation results for four typical small catchments were extended to the entire watershed leading to estimates of the NPS load from 2001 to 2009. The results demonstrated that the NPS pollution load in the western area was the highest and that agricultural land was the primary pollutant source. The similar annual variation trends of runoff and sediment loads demonstrated that the sediment load was closely related to runoff. The loads of total nitrogen (TN) and total phosphorus (TP) were relatively stable from 2001 to 2007, except for high loads in 2006. The increase in pollution source strength was an important reason for the significant upward trend of TN and TP loads from 2008 to 2009. The rainfall from April to October contributed to the largest amount of runoff, sediment and nutrient loads for the year. The NPS load intensities in each sub-basin reveal large variations in the spatial distribution of different pollutants. It was shown that the temporal and spatial distributions of pollutant loads were positively correlated with the annual rainfall amounts and with human activities. Furthermore, this finding illustrates that conservation practices and nutrient management should be implemented in specific sites during special periods for the purpose of NPS pollution control in the TGRR. PMID:24946028

  12. Tracking nonpoint nitrogen pollution from urbanizing watersheds (Invited)

    NASA Astrophysics Data System (ADS)

    Kaushal, S.; Groffman, P. M.; Band, L. E.; Elliott, E. M.; Shields, C. A.; Kendall, C.

    2010-12-01

    Nonpoint source nitrogen (N) pollution is a leading contributor of water quality impairments including coastal eutrophication and hypoxia. Improved identification of nonpoint N sources will be critical in prioritizing strategies for watershed N reductions. We combined long-term monitoring, watershed mass balances, and stable isotope source identification methods to investigate impacts of land use and hydrology on transport and transformation of nonpoint source N in forest, agricultural, and urbanized catchments at the Baltimore Ecosystem Study Long-term Ecological Research (LTER) site in Baltimore, Maryland. Human population and wastewater N in residential and suburban areas has doubled over a 50 year period in this region of the Chesapeake Bay watershed and represents an emerging challenge for nonpoint N sources. Mass balances suggested that a substantial proportion of N entering watersheds is retained and transformed based on annual runoff patterns, but that nonpoint sources showed differential susceptibility to watershed N exports in response to climate variability. Isotope data suggested that denitrification in watersheds was removing septic system and agriculturally-derived N, but N from leaking sewers was less susceptible to denitrification. Efforts to reduce nonpoint N sources should enhance watershed denitrification sinks across climatic conditions, and repair of aging urban infrastructure and leaking sewer lines should be a priority. Managing N inputs near streams and below the rooting zone may play a disproportionately large role in regulating N exports in human-dominated watersheds.

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

    NASA Astrophysics Data System (ADS)

    Wang, M.; Cheng, W.; Yu, B.-S.; Fang, Y.

    2015-05-01

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

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

    PubMed

    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. PMID:21805381

  15. Mitigation of nonpoint source pesticide contamination in a artificial wetland located at the outlet of a vineyard catchment

    NASA Astrophysics Data System (ADS)

    Payraudeau, S.; Gregoire, C.; Imfeld, G.

    2009-04-01

    The use of artificial wetlands for mitigating nonpoint source pesticide contamination from surface water runoff of agricultural origin represents an innovative approach, whose potential should be evaluated. The EU LIFE project ArtWET assesses the application of ecological bioengineering methods based on various types of artificial wetlands throughout Europe. In this framework, this study focused on the mitigation of pesticides in a storm basin (320 m2; 1500m3; planted with Phragmites australis Cav.) collecting runoff from a vineyard catchment area (42 ha; Rouffach, Alsace, France) over the cultural period (March to October 2008), and whose the hydraulic design has been modified in order to enhance the mitigation process. Discharge measurements and water samples collections were carried out in parallel at the inflow and the outflow of the basin for 17 runoff events in order to evaluate the load of 17 pesticides. Among the target pesticides, Glyphosate, AMPA, its metabolites, and Diuron predominated and runoff event pesticides loads strongly varied throughout cultural period. The depletion of the Glyphosate and AMPA concentration values recorded over the runoff event between the inflow and outflow of the system exceeded 70 %, and reached 90% when considering the total loads over the runoff event. The high mitigation capacity observed in the storm water wetland was likely due to both degradation and sorption processes. Current efforts focus on characterizing the variability over the cropping season of the wetland system performance in terms of reduction of pesticide loads in relationship with the biogeochemical conditions within the storm basin.

  16. A spatial model to aggregate point-source and nonpoint-source water-quality data for large areas

    USGS Publications Warehouse

    White, D.A.; Smith, R.A.; Price, C.V.; Alexander, R.B.; Robinson, K.W.

    1992-01-01

    More objective and consistent methods are needed to assess water quality for large areas. A spatial model, one that capitalizes on the topologic relationships among spatial entities, to aggregate pollution sources from upstream drainage areas is described that can be implemented on land surfaces having heterogeneous water-pollution effects. An infrastructure of stream networks and drainage basins, derived from 1:250,000-scale digital-elevation models, define the hydrologic system in this spatial model. The spatial relationships between point- and nonpoint pollution sources and measurement locations are referenced to the hydrologic infrastructure with the aid of a geographic information system. A maximum-branching algorithm has been developed to simulate the effects of distance from a pollutant source to an arbitrary downstream location, a function traditionally employed in deterministic water quality models. ?? 1992.

  17. Using NASA and Earth Science Products to Improve EPA Non-point Source Water Quality Modeling for the Chesapeake Bay

    NASA Astrophysics Data System (ADS)

    Toll, D.; Engman, T.; Edward, P.; Magness, A.; Townsend, P.; N-Meister, W.; Nigro, J.; Lee, S.

    2007-12-01

    The Environmental Protection Agency (EPA) estimates that over 20,000 bodies of water throughout the country do not meet water quality standards. Nonpoint sources -- pollution from urban, agricultural, and forest land that is transported by runoff -- typically cause 90 percent of impairments. EPA has developed the BASINS (Better Assessment Science Integrating Point and Nonpoint Sources) modeling system for performing numerous water quality studies. The key to this suite of models is the Hydrological Simulation Program - Fortran (HSPF), which calculates daily stream flow rates and the corresponding pollutant concentrations at the watershed outlet. EPA has partnered with NASA to use high spatial and temporal hydrological variables (e.g., precipitation, evaporation, etc.) from the NASA Land Information System (LIS) and land cover/vegetative indices derived from primarily MODIS and Landsat satellite data non-point source water quality for the Chesapeake Bay Basin. For the precipitation and evaporation data, EPA-based BASINS-HSPF streamflow runs were conducted on seven study watersheds in the Chesapeake Bay Basin. Sets of runs using precipitation from default weather stations, the NASA LIS 1/8th degree precipitation, NOAA Stage IV precipitation, NASA LIS Noah land surface model evapotranspiration datasets were conducted for each watershed. The output statistics summarized reveal that for 74% of the runs, the NASA LIS 1/8th degree and Stage IV precipitation-based runs performed better than when using only the default EPA precipitation station data. In addition, an automatic calibration method ('PEST') and Noah land surface model evapotranspiration (ET) being further incorporated. The empirical ability of generalized spectral indices and land cover derived from Landsat and MODIS was tested for predicting stream water nitrogen export from predominately forested watersheds undergoing disturbance. The disturbance index, a summary index that is easily computed from Landsat

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

    USGS Publications Warehouse

    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.

  19. [Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

    PubMed

    Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

    2015-07-01

    Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff. PMID:26710649

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

    PubMed

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

    2016-01-01

    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. PMID:27406070

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

    PubMed Central

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

    2016-01-01

    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. PMID:27406070

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Enhancements of nonpoint source monitoring of volatile organic compounds in ground water

    USGS Publications Warehouse

    Lapham, W.W.; Moran, M.J.; Zogorski, J.S.

    2000-01-01

    The U.S. Geological Survey (USGS) has compiled a national retrospective data set of analyses of volatile organic compounds (VOCs) in ground water of the United States. The data are from Federal, State, and local nonpoint-source monitoring programs, collected between 1985–95. This data set is being used to augment data collected by the USGS National Water-Quality Assessment (NAWQA) Program to ascertain the occurrence of VOCs in ground water nationwide. Eleven attributes of the retrospective data set were evaluated to determine the suitability of the data to augment NAWQA data in answering occurrence questions of varying complexity. These 11 attributes are the VOC analyte list and the associated reporting levels for each VOC, well type, well-casing material, type of openings in the interval (screened interval or open hole), well depth, depth to the top and bottom of the open interval(s), depth to water level in the well, aquifer type (confined or unconfined), and aquifer lithology. VOCs frequently analyzed included solvents, industrial reagents, and refrigerants, but other VOCs of current interest were not frequently analyzed. About 70 percent of the sampled wells have the type of well documented in the data set, and about 74 percent have well depth documented. However, the data set generally lacks documentation of other characteristics, such as well-casing material, information about the screened or open interval(s), depth to water level in the well, and aquifer type and lithology. For example, only about 20 percent of the wells include information on depth to water level in the well and only about 14 percent of the wells include information about aquifer type. The three most important enhancements to VOC data collected in nonpoint-source monitoring programs for use in a national assessment of VOC occurrence in ground water would be an expanded VOC analyte list, recording the reporting level for each analyte for every analysis, and recording key ancillary

  4. Nonpoint source pollution responses simulation for conversion cropland to forest in mountains by SWAT in China.

    PubMed

    Ouyang, Wei; Hao, Fang-Hua; Wang, Xue-Lei; Cheng, Hong-Guang

    2008-01-01

    Several environmental protection policies have been implemented to prevent soil erosion and nonpoint source (NPS) pollutions in China. After severe Yangtze River floods, the "conversion cropland to forest policy" (CCFP) was carried out throughout China, especially in the middle and upper reaches of Yangtze River. The research area of the current study is located in Bazhong City, Sichuan Province in Yangtze River watershed, where soil erosion and NPS pollution are serious concerns. Major NPS pollutants include nitrogen (N) and phosphorus (P). The objective of this study is to evaluate the long-term impact of implementation of the CCFP on stream flow, sediment yields, and the main NPS pollutant loading at watershed level. The Soil and Water Assessment Tool (SWAT) is a watershed environmental model and is applied here to simulate and quantify the impacts. Four scenarios are constructed representing different patterns of conversion from cropland to forest under various conditions set by the CCFP. Scenario A represented the baseline, i.e., the cropland and forest area conditions before the implementation of CCFP. Scenario B represents the condition under which all hillside cropland with slope larger than 25 degrees was converted into forest. In scenario C and D, hillside cropland with slope larger than 15 degrees and 7.5 degrees was substituted by forest, respectively. Under the various scenarios, the NPS pollution reduction due to CCFP implementation from 1996-2005 is estimated by SWAT. The results are presented as percentage change of water flow, sediment, organic N, and organic P at watershed level. Furthermore, a regression analysis is conducted between forest area ratio and ten years' average NPS load estimations, which confirmed the benefits of implementing CCFP in reducing nonpoint source pollution by increasing forest area in mountainous areas. The reduction of organic N and organic P is significant (decrease 42.1% and 62.7%, respectively) at watershed level. In

  5. Nonpoint source solute transport normal to aquifer bedding in heterogeneous, Markov chain random fields

    NASA Astrophysics Data System (ADS)

    Zhang, Hua; Harter, Thomas; Sivakumar, Bellie

    2006-06-01

    Facies-based geostatistical models have become important tools for analyzing flow and mass transport processes in heterogeneous aquifers. Yet little is known about the relationship between these latter processes and the parameters of facies-based geostatistical models. In this study, we examine the transport of a nonpoint source solute normal (perpendicular) to the major bedding plane of an alluvial aquifer medium that contains multiple geologic facies, including interconnected, high-conductivity (coarse textured) facies. We also evaluate the dependence of the transport behavior on the parameters of the constitutive facies model. A facies-based Markov chain geostatistical model is used to quantify the spatial variability of the aquifer system's hydrostratigraphy. It is integrated with a groundwater flow model and a random walk particle transport model to estimate the solute traveltime probability density function (pdf) for solute flux from the water table to the bottom boundary (the production horizon) of the aquifer. The cases examined include two-, three-, and four-facies models, with mean length anisotropy ratios for horizontal to vertical facies, ek, from 25:1 to 300:1 and with a wide range of facies volume proportions (e.g., from 5 to 95% coarse-textured facies). Predictions of traveltime pdfs are found to be significantly affected by the number of hydrostratigraphic facies identified in the aquifer. Those predictions of traveltime pdfs also are affected by the proportions of coarse-textured sediments, the mean length of the facies (particularly the ratio of length to thickness of coarse materials), and, to a lesser degree, the juxtapositional preference among the hydrostratigraphic facies. In transport normal to the sedimentary bedding plane, traveltime is not lognormally distributed as is often assumed. Also, macrodispersive behavior (variance of the traveltime) is found not to be a unique function of the conductivity variance. For the parameter range

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

    PubMed

    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

  7. Alternative energy sources for agriculture

    SciTech Connect

    Baird, D.

    1981-05-01

    The following energy systems are discussed as alternative sources of energy for agriculture and potential demonstration projects in vocational agriculture programs: solar water heating, solar greenhouse heating, solar crop drying, gasification of wood or crop residues, and methane generation from livestock wastes. 13 references.

  8. Differentiating nonpoint sources of deisopropylatrazine in surface water using discrimination diagrams.

    PubMed

    Meyer, M T; Thurman, E M; Goolsby, D A

    2001-01-01

    Pesticide degradates account for a significant portion of the pesticide load in surface water. Because pesticides with similar structures may degrade to the same degradate, it is important to distinguish between different sources of parent compounds that have different regulatory and environmental implications. A discrimination diagram, which is a sample plot of chemical data that differentiates between different parent compounds, was used for the first time to distinguish whether sources other than atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) contributed the chlorinated degradate, deisopropylatrazine (DIA; 6-chloro-N-ethyl-1,3,5-triazine-2,4-diamine) to the Iroquois and Delaware Rivers. The concentration ratio of deisopropylatrazine to deethylatrazine [6-chloro-N-(1-methylethyl)1,3,5-triazine-2,4-diamine], called the D2R, was used to discriminate atrazine as a source of DIA from other parent sources, such as cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile) and simazine (6-chloro-N,N'-diethyl-1,3,5-triazine-2,4diamine). The ratio of atrazine to cyanazine (ACR) used in conjunction with the D2R showed that after atrazine, cyanazine was the main contributor of DIA in surface water. The D2R also showed that cyanazine, and to a much lesser extent simazine, contributed a considerable amount (approximately 40%) of the DIA that was transported during the flood of the Mississippi River in 1993. The D2R may continue to be a useful discriminator in determining changes in the nonpoint sources of DIA in surface water as cyanazine is currently being removed from the market. PMID:11577893

  9. Differentiating nonpoint sources of deisopropylatrazine in surface water using discrimination diagrams

    USGS Publications Warehouse

    Meyer, M.T.; Thurman, E.M.; Goolsby, D.A.

    2001-01-01

    Pesticide degradates account for a significant portion of the pesticide load in surface water. Because pesticides with similar structures may degrade to the same degradate, it is important to distinguish between different sources of parent compounds that have different regulatory and environmental implications. A discrimination diagram, which is a sample plot of chemical data that differentiates between different parent compounds, was used for the first time to distinguish whether sources other than atrazine (6-chloro-N2-ethyl-N4-isopropyl-1, 3,5-triazine-2,4-diamine) contributed the chlorinated degradate, deisopropylatrazine (DIA; 6-chloro-N-ethyl-1,3,5-triazine-2,4-diamine) to the Iroquois and Delaware Rivers. The concentration ratio of deisopropylatrazine to deethylatrazine [6-chloro-N-(1-methylethyl)-1, 3,5-triazine-2,4-diamine], called the D2R, was used to discriminate atrazine as a source of DIA from other parent sources, such as cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile) and simazine (6-chloro-N,N???-diethyl-1,3,5-triazine-2,4-diamine). The ratio of atrazine to cyanazine (ACR) used in conjunction with the D2R showed that after atrazine, cyanazine was the main contributor of DIA in surface water. The D2R also showed that cyanazine, and to a much lesser extent simazine, contributed a considerable amount (???40%) of the DIA that was transported during the flood of the Mississippi River in 1993. The D2R may continue to be a useful discriminator in determining changes in the nonpoint sources of DIA in surface water as cyanazine is currently being removed from the market.

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

    PubMed

    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. PMID:12079107

  11. Percentage of Probability of Nonpoint-Source Nitrate Contamination of Recently Recharged Ground Water in the High Plains Aquifer

    USGS Publications Warehouse

    Qi, Sharon L.; Gurdak, Jason J.

    2006-01-01

    This raster data set represents the percentage of probability of nonpoint-source nitrate contamination (greater than the proposed background concentration of 4 milligrams per liter (mg/L) as N) of recently (defined as less than 50 years) recharged ground water in the High Plains aquifer of the United States. The High Plains aquifer covers approximately 175,000 square miles in eight States; Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Elevated nitrate concentrations above the background concentration have been detected in recently recharged (less than 50 years) ground water in the High Plains aquifer. This data set is derived from empirical models developed using multivariate logistic regression to evaluate the vulnerability of the High Plains aquifer to nitrate contamination from nonpoint sources. This data set was generated in a geographic information system from these models and represents the spatial extent of vulnerability of nitrate contamination greater than 4 mg/L across the aquifer.

  12. Validation and future predictions based on a new Non-Point Source Assessment Toolbox, applied to the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Kourakos, G.; Harter, T.

    2011-12-01

    Groundwater is a major irrigation water source in semi-arid regions. It is also vulnerable to Non-Point Source (NPS) contamination, particularly from nitrate (NO3-) as a result of agricultural practices. To support sound policy decisions we developed a physically based flow and transport model framework to understand and predict the fate of contaminants within regional aquifer systems. In large aquifers, the total source area of pollutants typically cover several thousand square kilometers, whilst individual sources typically do not exceed a few hundred square meters. The large contrast in these scenarios result in NPS modeling tasks that are computationally demanding, and the classical 3D models that solve the Advection-Dispersion Equation (ADE) are often not applicable due to computer memory limitations, numerical dispersion and numerical instabilities. Here, we developed and employed a number of numerical techniques to assemble a Non-Point Source Assessment Toolbox (NPSAT). The NPSAT is a quasi-3D model, combining a flow model and a streamline transport model. The flow model solves the groundwater flow equation using very fine discretization. For very large groundwater basins, a simplistic decomposition method is applied, splitting the aquifer into several overlapping sub-domains and solving to produce a high resolution velocity field. This velocity field is subsequently utilized within the transport model, where backward particle tracking links contamination sources with discharge surfaces using a large number of streamlines. For each streamline the 1D ADE is solved, assuming a unit pulse loading at the source side and a free exit boundary condition at the discharge surface side. From this, a Unit Response Function (URF) is obtained at the discharge surface side. Subsequently, actual Breakthrough Curves (BTCs) can be quickly computed from actual or hypothetical loading histories, by convoluting the URFs with real loading functions. The URFs are stored into a

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

    NASA Astrophysics Data System (ADS)

    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).

  14. A comprehensive evaluation of input data-induced uncertainty in nonpoint source pollution modeling

    NASA Astrophysics Data System (ADS)

    Chen, L.; Gong, Y.; Shen, Z.

    2015-11-01

    Watershed models have been used extensively for quantifying nonpoint source (NPS) pollution, but few studies have been conducted on the error-transitivity from different input data sets to NPS modeling. In this paper, the effects of four input data, including rainfall, digital elevation models (DEMs), land use maps, and the amount of fertilizer, on NPS simulation were quantified and compared. A systematic input-induced uncertainty was investigated using watershed model for phosphorus load prediction. Based on the results, the rain gauge density resulted in the largest model uncertainty, followed by DEMs, whereas land use and fertilizer amount exhibited limited impacts. The mean coefficient of variation for errors in single rain gauges-, multiple gauges-, ASTER GDEM-, NFGIS DEM-, land use-, and fertilizer amount information was 0.390, 0.274, 0.186, 0.073, 0.033 and 0.005, respectively. The use of specific input information, such as key gauges, is also highlighted to achieve the required model accuracy. In this sense, these results provide valuable information to other model-based studies for the control of prediction uncertainty.

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

    PubMed

    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. PMID:11804154

  16. Combined Bayesian statistics and load duration curve method for bacteria nonpoint source loading estimation.

    PubMed

    Shen, Jian; Zhao, Yuan

    2010-01-01

    Nonpoint source load estimation is an essential part of the development of the bacterial total maximum daily load (TMDL) mandated by the Clean Water Act. However, the currently widely used watershed-receiving water modeling approach is usually associated with a high level of uncertainty and requires long-term observational data and intensive training effort. The load duration curve (LDC) method recommended by the EPA provides a simpler way to estimate bacteria loading. This method, however, does not take into consideration the specific fate and transport mechanisms of the pollutant and cannot address the uncertainty. In this study, a Bayesian statistical approach is applied to the Escherichia coli TMDL development of a stream on the Eastern Shore of Virginia to inversely estimate watershed bacteria loads from the in-stream monitoring data. The mechanism of bacteria transport is incorporated. The effects of temperature, bottom slope, and flow on allowable and existing load calculations are discussed. The uncertainties associated with load estimation are also fully described. Our method combines the merits of LDC, mechanistic modeling, and Bayesian statistics, while overcoming some of the shortcomings associated with these methods. It is a cost-effective tool for bacteria TMDL development and can be modified and applied to multi-segment streams as well. PMID:19781737

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

    PubMed Central

    Chen, Lei; Wei, Guoyuan; Shen, Zhenyao

    2015-01-01

    To solve computationally intensive and technically complex control of nonpoint source pollution, the traditional genetic algorithm was modified into an auto-adaptive pattern, and a new framework was proposed by integrating this new algorithm with a watershed model and an economic module. Although conceptually simple and comprehensive, the proposed algorithm would search automatically for those Pareto-optimality solutions without a complex calibration of optimization parameters. The model was applied in a case study in a typical watershed of the Three Gorges Reservoir area, China. The results indicated that the evolutionary process of optimization was improved due to the incorporation of auto-adaptive parameters. In addition, the proposed algorithm outperformed the state-of-the-art existing algorithms in terms of convergence ability and computational efficiency. At the same cost level, solutions with greater pollutant reductions could be identified. From a scientific viewpoint, the proposed algorithm could be extended to other watersheds to provide cost-effective configurations of BMPs. PMID:26487474

  18. Reducing Nonpoint Source Pollution Through Collaboration: Policies and Programs Across the U.S. States

    NASA Astrophysics Data System (ADS)

    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.

  19. Stochastic modeling of the rainfall-runoff process for nonpoint source pollutant load estimation

    SciTech Connect

    Dickey, R.O.

    1989-01-01

    A stochastic simulation methodology was developed for the rainfall runoff process to assist in the assessment of nonpoint source pollutant loads, particularly for ungaged watersheds where there is a scarcity or complete lack of historical data. The methodology was developed based on simulating individual rainfall-runoff events. A simulation model employed a rainfall simulator to stochastically generate rainfall event characteristics for input into basin hydrologic transformation functions which then predicted the corresponding runoff hydrograph characteristics. Also addressed was the impact of limited data availability on the ability to model the rainfall-runoff process. An evaluation was conducted of the degree to which committing valuable resources to expand the data base would provide measurable improvement in model results. Specifically, the probability of achieving certain levels of accuracy with the simulation model was statistically assessed as a function of the number of observed rainfall-runoff events used for model development. The probability of monitoring various numbers of rainfall-runoff events in specified time intervals was also established as an aid for planning field monitoring studies. The simulation methodology was applied to a study watershed in the Lake Ray Hubbard reservoir drainage basin near Dallas, Texas. Regional rainfall characteristics were established using historical hourly data from the Federal Aviation Administration rain gage at Love Field Airport in Dallas, Texas. Hourly rainfall data were resolved into individual rainfall events and probability density functions were identified for event volume, time between events, and event duration.

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

    PubMed

    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. PMID:27135563

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

    PubMed

    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. PMID:27146539

  2. Impact of spatial rainfall variability on hydrology and nonpoint source pollution modeling

    NASA Astrophysics Data System (ADS)

    Shen, Zhenyao; Chen, Lei; Liao, Qian; Liu, Ruimin; Hong, Qian

    2012-11-01

    Rainfall is regarded as the most important input for the hydrology and nonpoint source (H/NPS) models and uncertainty related to rainfall is generally recognized as a major challenge in watershed modeling. In this paper, we focus on the impact of spatial rainfall variability on H/NPS modeling of a large watershed. The uncertainty introduced by spatial rainfall variability was determined using a number of commonly-used interpolation methods: (1) the Centroid method; (2) the Thiessen Polygon method; (3) the Inverse Distance Weighted (IDW) method; (4) the Dis-Kriging method; and (5) the Co-Kriging method. The Soil and Water Assessment tool (SWAT) was used to quantify the effect of rainfall spatial variability on watershed H/NPS modeling of the Daning watershed in China. Results indicated that these interpolation methods could contribute significant uncertainty in spatial rainfall variability and the carry-magnify effect caused even larger uncertainty in the H/NPS modeling. This uncertainty was magnified from hydrology modeling (stream flow) into NPS modeling (sediment, TP, organic nitrogen (N) and dissolved N). This study further suggested that H/NPS prediction uncertainty relating to spatial rainfall variability was scale-dependent due to the averaging effect of spatial heterogeneity. From a practical point of view, a global interpolation method, such as IDW and Kriging, as well as elevation data derived from a digital elevation model (DEM), should be included into the H/NPS models for reliable predictions in larger watersheds.

  3. Herbicide transport in rivers: Importance of hydrology and geochemistry in nonpoint-source contamination

    USGS Publications Warehouse

    Squillace, P.J.; Thurman, E.M.

    1992-01-01

    Alachlor, atrazine, cyanazine, metolachlor, and metribuzin were measured at six sites during 1984 and 1985 in large subbasins within the Cedar River, IA. A computer model separated the Cedar River discharge hydrograph into groundwater and overland-flow components. The concentration of herbicides in the river when groundwater was the major flow component was less than 1.0 μg/L and averaged 0.2 μg/L. The maximum concentrations of herbicides occurred when overland flow was the major component of river discharge, exceeding 50 pg/L for total herbicides. About 6% of the annual river load of atrazine was transported with the groundwater component, while 94% was transported with overland flow. From 1.5 to 5% of the atrazine applied during the year was transported from the basin. Atrazine concentrations in the river in- creased according to the discharge divided by the drainage area. This correlation indicates that rivers with large normalized 2-year peak flows have the potential to transport large concentrations of herbicides. A diagrammatic model of nonpoint-source transport of herbicides was developed that suggests that sorbed transport from fields occurs during episodes of overland flow with rapid dissolution of herbicides downstream. 

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

    SciTech Connect

    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.

  5. New Antimicrobially Amended Media for Improved Nonpoint Source Bacterial Pollution Treatment.

    PubMed

    Schifman, Laura A; Kasaraneni, Varun K; Sullivan, Ryan K; Oyanedel-Craver, Vinka; Boving, Thomas B

    2015-12-15

    Nonpoint source pollution (NPS) such as stormwater runoff may introduce high loads of bacteria, impairing surface water bodies. The existing filter materials in stormwater best management practices (BMP) are typically not designed to inactivate bacteria. Herein, novel filtration media were extensively tested for microbial load reduction in stormwater runoff. Red cedar wood chips (RC) were amended with different loadings of either 3-(trihydroxysilyl) propyldimethyloctadecyl ammonium chloride (TPA) or silver nanoparticles (AgNP). Under batch conditions at 25 °C, log10 removal values (LRV) up to 3.71 ± 0.38 (mean ± standard error) for TPA-RC and 2.25 ± 1.00 for AgNP-RC were achieved for Escherichia coli (E. coli), whereas unmodified RC achieved less than 0.5 LRV. Similar trends were observed at 17.5 °C, however at low temperature (10 °C) no statistically significant difference in E. coli inactivation between modified and unmodified RC was detected. Inactivation kinetic studies show that TPA-RC has higher inactivation rate constants compared to AgNP-RC. Under dynamic flow conditions a mass balance approach indicates that even after remobilization up to 99.8% of E. coli removal using 9 mg/g TPA-RC compared to 64.8% for unmodified RC. This study demonstrates that RC wood chips amended with antimicrobial compounds show promising applications as filtration material for the reduction of microbiological contamination load in stormwater runoff. PMID:26562065

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Evaluation of a non-point source pollution model, AnnAGNPS, in a tropical watershed

    USGS Publications Warehouse

    Polyakov, V.; Fares, A.; Kubo, D.; Jacobi, J.; Smith, C.

    2007-01-01

    Impaired water quality caused by human activity and the spread of invasive plant and animal species has been identified as a major factor of degradation of coastal ecosystems in the tropics. The main goal of this study was to evaluate the performance of AnnAGNPS (Annualized Non-Point Source Pollution Model), in simulating runoff and soil erosion in a 48 km2 watershed located on the Island of Kauai, Hawaii. The model was calibrated and validated using 2 years of observed stream flow and sediment load data. Alternative scenarios of spatial rainfall distribution and canopy interception were evaluated. Monthly runoff volumes predicted by AnnAGNPS compared well with the measured data (R2 = 0.90, P < 0.05); however, up to 60% difference between the actual and simulated runoff were observed during the driest months (May and July). Prediction of daily runoff was less accurate (R2 = 0.55, P < 0.05). Predicted and observed sediment yield on a daily basis was poorly correlated (R2 = 0.5, P < 0.05). For the events of small magnitude, the model generally overestimated sediment yield, while the opposite was true for larger events. Total monthly sediment yield varied within 50% of the observed values, except for May 2004. Among the input parameters the model was most sensitive to the values of ground residue cover and canopy cover. It was found that approximately one third of the watershed area had low sediment yield (0-1 t ha-1 y-1), and presented limited erosion threat. However, 5% of the area had sediment yields in excess of 5 t ha-1 y-1. Overall, the model performed reasonably well, and it can be used as a management tool on tropical watersheds to estimate and compare sediment loads, and identify "hot spots" on the landscape. ?? 2007 Elsevier Ltd. All rights reserved.

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

    PubMed

    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. PMID:16418902

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

    USGS Publications Warehouse

    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.

  12. Identifying non-point source critical source areas based on multi-factors at a basin scale with SWAT

    NASA Astrophysics Data System (ADS)

    Liu, Ruimin; Xu, Fei; Zhang, Peipei; Yu, Wenwen; Men, Cong

    2016-02-01

    The identification of critical source areas (CSAs) is a precondition for non-point source (NPS) pollution control at a basin scale, especially in areas with limited resources. Based on the Soil and Water Assessment Tool (SWAT), nutrient loads coupled with population density and water quality requirements are regarded as multi-factors for CSAs identification in Xiangxi river watershed, the first tributary of the Yangtze River. The results based on the calibrated model found that the subbasins heavily and seriously polluted by nutrient loads were different from the subbasins identified as CSAs, demonstrating integrating socio-economic factors like population density and water quality requirements to identify CSAs is of much necessity. The CSAs occupied 19.7% of the total subbasins, and accounted for 53% total nitrogen loads, 54% total phosphorus loads and 36% of the total population. Considering the model calibration and validation will take a long time as well as data deficiency in some subbasins, the influence of uncalibrated SWAT on CSAs identifications was discussed. The comparative results between CSAs identification with calibrated and uncalibrated SWAT model revealed that model calibration had little effect on nutrients distribution and CSAs locations in the study area. Uncalibrated SWAT model may be applied when the research objective is less related to model calibration. The results will be greatly effective for CSAs identification and NPS pollution control at a basin scale.

  13. Calculation and analysis of the non-point source pollution in the upstream watershed of the Panjiakou Reservoir, People's Republic of China

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Tang, L.

    2007-05-01

    Panjiakou Reservoir is an important drinking water resource in Haihe River Basin, Hebei Province, People's Republic of China. The upstream watershed area is about 35,000 square kilometers. Recently, the water pollution in the reservoir is becoming more serious owing to the non-point pollution as well as point source pollution on the upstream watershed. To effectively manage the reservoir and watershed and develop a plan to reduce pollutant loads, the loading of non-point and point pollution and their distribution on the upstream watershed must be understood fully. The SWAT model is used to simulate the production and transportation of the non-point source pollutants in the upstream watershed of the Panjiakou Reservoir. The loadings of non-point source pollutants are calculated for different hydrologic years and the spatial and temporal characteristics of non-point source pollution are studied. The stream network and topographic characteristics of the stream network and sub-basins are all derived from the DEM by ArcGIS software. The soil and land use data are reclassified and the soil physical properties database file is created for the model. The SWAT model was calibrated with observed data of several hydrologic monitoring stations in the study area. The results of the calibration show that the model performs fairly well. Then the calibrated model was used to calculate the loadings of non-point source pollutants for a wet year, a normal year and a dry year respectively. The time and space distribution of flow, sediment and non-point source pollution were analyzed depending on the simulated results. The comparison of different hydrologic years on calculation results is dramatic. The loading of non-point source pollution in the wet year is relatively larger but smaller in the dry year since the non-point source pollutants are mainly transported through the runoff. The pollution loading within a year is mainly produced in the flood season. Because SWAT is a

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    Non-point source inputs of total nitrogen (TN) and total phosphorus (TP) in rivers are the leading causes of water quality degradation in the United States (Turner and Rabalais, 2003; Broussard and Turner, 2009). Yet it remains a challenge to adequately quantify the relative role and influence of physical hydrological processes versus biogeochemical processes on the attenuation of TN and TP for individual river reaches. A watershed-scale study of instream dynamics and attenuation of TN and TP in northeastern U.S. headwater streams demonstrates that physical and hydrological processes exert greater control over nutrient removal than biogeochemical processes. To explore these interactions under various attenuation scenarios, we developed the watershed-scale model (WARMF) for 97 catchments to simulate watershed processes, hydrology, and diffuse source loads of nutrients. We simulated a hypothetical nutrient release at a rate of 1 kg/d of TN (50% as ammonium and 50% as nitrate) and TP (100% as phosphate) to predict response lengths of downstream catchments. Resulting attenuation factors are presented as the change in mean load at a given location, normalized to the change in the catchment in which the load is applied. Results indicate that for most catchments, the TN and TP load increase is attenuated from the stream within a few tens of kilometers. Fifty percent attenuation occurs across length scales ranging from a few hundreds of meters to kilometers if the load is introduced in the headwaters, indicating the most rapid nutrient removal occurs in the smallest headwater streams but generally decreases with distance downstream. There are some differences in the attenuation factors for TN and TP, although the pattern of attenuation is the same. Sensitivity analyses highlight five hydrological parameters of paramount importance to concentrations of N and P, namely precipitation, evaporation coefficients (magnitude and skewness), soil layer thickness, soil saturated

  15. Modeling non-point source pollutants in the vadose zone: Back to the basics

    NASA Astrophysics Data System (ADS)

    Corwin, Dennis L.; Letey, John, Jr.; Carrillo, Marcia L. K.

    More than ever before in the history of scientific investigation, modeling is viewed as a fundamental component of the scientific method because of the relatively recent development of the computer. No longer must the scientific investigator be confined to artificially isolated studies of individual processes that can lead to oversimplified and sometimes erroneous conceptions of larger phenomena. Computer models now enable scientists to attack problems related to open systems such as climatic change, and the assessment of environmental impacts, where the whole of the interactive processes are greater than the sum of their isolated components. Environmental assessment involves the determination of change of some constituent over time. This change can be measured in real time or predicted with a model. The advantage of prediction, like preventative medicine, is that it can be used to alter the occurrence of potentially detrimental conditions before they are manifest. The much greater efficiency of preventative, rather than remedial, efforts strongly justifies the need for an ability to accurately model environmental contaminants such as non-point source (NPS) pollutants. However, the environmental modeling advances that have accompanied computer technological development are a mixed blessing. Where once we had a plethora of discordant data without a holistic theory, now the pendulum has swung so that we suffer from a growing stockpile of models of which a significant number have never been confirmed or even attempts made to confirm them. Modeling has become an end in itself rather than a means because of limited research funding, the high cost of field studies, limitations in time and patience, difficulty in cooperative research and pressure to publish papers as quickly as possible. Modeling and experimentation should be ongoing processes that reciprocally enhance one another with sound, comprehensive experiments serving as the building blocks of models and models

  16. Agricultural Wastes.

    ERIC Educational Resources Information Center

    Jewell, W. J.; Switzenbaum, M. S.

    1978-01-01

    Presents a literature review of agricultural wastes, covering publications of 1976-77. Some of the areas covered are: (1) water characteristics and impacts; (2) waste treatment; (3) reuse of agricultural wastes; and (4) nonpoint pollution sources. A list of 150 references is also presented. (HM)

  17. Sediment composition for the assessment of water erosion and nonpoint source pollution in natural and fire-affected landscapes.

    PubMed

    Carkovic, Athena B; Pastén, Pablo A; Bonilla, Carlos A

    2015-04-15

    Water erosion is a leading cause of soil degradation and a major nonpoint source pollution problem. Many efforts have been undertaken to estimate the amount and size distribution of the sediment leaving the field. Multi-size class water erosion models subdivide eroded soil into different sizes and estimate the aggregate's composition based on empirical equations derived from agricultural soils. The objective of this study was to evaluate these equations on soil samples collected from natural landscapes (uncultivated) and fire-affected soils. Chemical, physical, and soil fractions and aggregate composition analyses were performed on samples collected in the Chilean Patagonia and later compared with the equations' estimates. The results showed that the empirical equations were not suitable for predicting the sediment fractions. Fine particles, including primary clay, primary silt, and small aggregates (<53 μm) were over-estimated, and large aggregates (>53 μm) and primary sand were under-estimated. The uncultivated and fire-affected soils showed a reduced fraction of fine particles in the sediment, as clay and silt were mostly in the form of large aggregates. Thus, a new set of equations was developed for these soils, where small aggregates were defined as particles with sizes between 53 μm and 250 μm and large aggregates as particles>250 μm. With r(2) values between 0.47 and 0.98, the new equations provided better estimates for primary sand and large aggregates. The aggregate's composition was also well predicted, especially the silt and clay fractions in the large aggregates from uncultivated soils (r(2)=0.63 and 0.83, respectively) and the fractions of silt in the small aggregates (r(2)=0.84) and clay in the large aggregates (r(2)=0.78) from fire-affected soils. Overall, these new equations proved to be better predictors for the sediment and aggregate's composition in uncultivated and fire-affected soils, and they reduce the error when estimating soil loss in

  18. The precipitation driven correlation based mapping method (PCM) for identifying the critical source areas of non-point source pollution

    NASA Astrophysics Data System (ADS)

    Huang, Jinhui Jeanne; Lin, Xiaojuan; Wang, Jianhua; Wang, Hao

    2015-05-01

    Critical source areas (CSAs) are the areas that are relatively more erosion-prone and contribute significantly more pollutants per unit area. They have been widely recognized as optimal locations for the control of non-point source (NPS) pollution. Modeling approach has been frequently used to identify the CSAs of NPS pollution on a basin scale. In previous studies, CSAs were identified based on the simulated average annual nutrient yields for the simulation period at the levels of sub-basin or hydrologic response unit (HRU). However, this method did not consider the impact of uneven spatial distribution of precipitation, which is considered to be the driven force of NPS pollution. In many cases, due to limited length of qualified monitoring data collected, the simulation period may not cover a full spectrum of the precipitation characteristics so that some potential CSAs may be missed. In the present study, the precipitation driven correlation based mapping method (PCM) was proposed, which can reduce the impact of uncertain spatial-temporal distribution of precipitation and identify the CSAs of NPS pollution with a better coverage. This method was applied to the Zhang River Basin, a watershed in North China that occupies an area of 18,072 km2. The SWAT (Soil and Water Assessment Tool) was used for simulation purposes. By using PCM, the maps of CSAs for controlling total nitrogen (TN) and total phosphorus (TP) were produced. This study has found that the monthly precipitation is highly correlated with the TN and TP yields. It was observed that TN yields have slightly higher correlation value with the precipitation than TP yields. Hence, the precipitation has more impacts on TN yields than TP yields. The impact is more substantial in urban areas than other areas.

  19. [Empirical study on non-point sources pollution based on landscape pattern & ecological processes theory: a case of soil water loss on the Loess Plateau in China].

    PubMed

    Suo, An-ning; Wang, Tian-ming; Wang, Hui; Yu, Bo; Ge, Jian-ping

    2006-12-01

    Non-point sources pollution is one of main pollution modes which pollutes the earth surface environment. Aimed at soil water loss (a typical non-point sources pollution problem) on the Losses Plateau in China, the paper applied a landscape patternevaluation method to twelve watersheds of Jinghe River Basin on the Loess Plateau by means of location-weighted landscape contrast index(LCI) and landscape slope index(LSI). The result showed that LSI of farm land, low density grass land, forest land and LCI responded significantly to soil erosion modulus and responded to depth of runoff, while the relationship between these landscape index and runoff variation index and erosion variation index were not statistically significant. This tell us LSI and LWLCI are good indicators of soil water loss and thus have big potential in non-point source pollution risk evaluation. PMID:17304833

  20. Better assessment science integrating point and nonpoint sources (BASINS), version 2.0. User`s manual

    SciTech Connect

    Lahlou, M.; Shoemaker, L.; Choudhury, S.; Elmer, R.; Hu, A.

    1998-11-01

    BASINS is a multipurpose environmental analysis system for use by regional, state, and local agencies in performing watershed- and water-quality-based studies. BASINS comprises a suite of interrelated components for performing the various aspects of environmental analysis. The six components include (1) nationally derived databases with Data Extraction tools and Project Builders; (2) assessment tools (TARGET, ASSESS, and Data Mining) that address large- and small-scale characterization needs; (3) utilites to facilitate organizing and evaluating data, including Watershed Delineation, Import, Land Use Reclassfication, and DEM Reclassification; (4) Watershed Characterization Reports that facilitate compilation and output of information on selected watersheds; (5) water quality models including TOXIROUTE and QUAL2E; and (6) the Nonpoint Source Model (NPSM) and postprocessor, which provide integrated assessment of watershed loading and transport, The assessment component, working under the GIS umbrella, allows users to quickly evaluate selected areas, organize information, and display results. The modeling component module allows users to examine the impacts of pollutant loadings from point and nonpoint sources.

  1. EM Sounding Characterization of Soil Environment toward Estimation of Potential Pollutant Load from Non-point Sources

    NASA Astrophysics Data System (ADS)

    Mori, Y.; Ide, J.; Somura, H.; Morisawa, T.

    2010-12-01

    A multi-frequency electro-magnetic (EM) sounding method was applied to agriculture fields to investigate the characteristics of non-point pollution load. Soil environmental properties such as differences in land management were analyzed with electrical conductivity (EC) maps. In addition, vertical EC profiles obtained from EM soundings were compared with EC in drainage ditch or river water. As results, surface soil EC maps successfully extracted the differences in land management affected by fertilizer application. Moreover, surface EC at the vertical profiles strongly related with drainage ditch or river EC, showing most of the EC in the water was explained by surface EC maps at the EM sounding data. The proposed method has strength in obtaining EC data without sampling river water, the situation we sometimes experienced at the field survey.

  2. A Spatial and Temporal Assessment of Non-Point Groundwater Pollution Sources, Tutuila Island, American Samoa

    NASA Astrophysics Data System (ADS)

    Shuler, C. K.; El-Kadi, A. I.; Dulaiova, H.; Glenn, C. R.; Fackrell, J.

    2015-12-01

    The quality of municipal groundwater supplies on Tutuila, the main island in American Samoa, is currently in question. A high vulnerability for contamination from surface activities has been recognized, and there exists a strong need to clearly identify anthropogenic sources of pollution and quantify their influence on the aquifer. This study examines spatial relationships and time series measurements of nutrients and other tracers to identify predominant pollution sources and determine the water quality impacts of the island's diverse land uses. Elevated groundwater nitrate concentrations are correlated with areas of human development, however, the mixture of residential and agricultural land use in this unique village based agrarian setting makes specific source identification difficult using traditional geospatial analysis. Spatial variation in anthropogenic impact was assessed by linking NO3- concentrations and δ15N(NO3) from an extensive groundwater survey to land-use types within well capture zones and groundwater flow-paths developed with MODFLOW, a numerical groundwater model. Land use types were obtained from high-resolution GIS data and compared to water quality results with multiple-regression analysis to quantify the impact that different land uses have on water quality. In addition, historical water quality data and new analyses of δD and δ18O in precipitation, groundwater, and mountain-front recharge waters were used to constrain the sources and mechanisms of contamination. Our analyses indicate that groundwater nutrient levels on Tutuila are controlled primarily by residential, not agricultural activity. Also a lack of temporal variation suggests that episodic pollution events are limited to individual water sources as opposed to the entire aquifer. These results are not only valuable for water quality management on Tutuila, but also provide insight into the sustainability of groundwater supplies on other islands with similar hydrogeology and land

  3. A paddy eco-ditch and wetland system to reduce non-point source pollution from rice-based production system while maintaining water use efficiency.

    PubMed

    Xiong, Yujiang; Peng, Shizhang; Luo, Yufeng; Xu, Junzeng; Yang, Shihong

    2015-03-01

    Non-point source (NPS) pollution from agricultural drainage has aroused widespread concerns throughout the world due to its contribution to eutrophication of water bodies. To remove nitrogen (N) and phosphorus (P) from agricultural drainage in situ, a Paddy Eco-ditch and Wetland System (PEDWS) was designed and built based on the characteristics of the irrigated rice district. A 2-year (2012-2013) field experiment was conducted to evaluate the performance of this system in Gaoyou Irrigation District in Eastern China. The results showed that the reduction in water input in paddy field of the PEDWS enabled the maintenance of high rice yield; it significantly increased irrigation water productivity (WPI), gross water productivity (WPG), and evapotranspiration water productivity (WPET) by 109.2, 67.1, and 17.6%, respectively. The PEDWS dramatically decreased N and P losses from paddy field. Compared with conventional irrigation and drainage system (CIDS), the amount of drainage water from PEDWS was significantly reduced by 56.2%, the total nitrogen (TN) concentration in drainage was reduced by 42.6%, and thus the TN and total phosphorus (TP) losses were reduced by 87.8 and 70.4%. PEDWS is technologically feasible and applicable to treat nutrient losses from paddy fields in situ and can be used in similar areas. PMID:25304242

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

    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.

  5. Evaluating potential non-point source loading of PAHs from contaminated soils: a fugacity-based modeling approach.

    PubMed

    Luo, Xiaolin; Zheng, Yi; Lin, Zhongrong; Wu, Bin; Han, Feng; Tian, Yong; Zhang, Wei; Wang, Xuejun

    2015-01-01

    Soils contaminated by Polycyclic Aromatic Hydrocarbons (PAHs) are subject to significant non-point source (NPS) pollution during rainfall events. Recent studies revealed that the classic enrichment ratio (ER) approach may not be applicable to PAHs. This study developed a model to estimate the ER of PAHs which innovatively applies the fugacity concept. The ER model has been validated with experimental data, which suggested that the transport of PAHs not only depends on their physicochemical properties, but on the sediment composition and how the composition evolves during the event. The modeling uncertainty was systematically examined, and found to be highly compound-dependent. Based on the ER model, a strategy was proposed to practically evaluate the potential NPS loading of PAHs in watersheds with heterogeneous soils. The study results have important implications to modeling and managing the NPS pollution of PAHs (or other chemicals alike) at a watershed scale. PMID:25282126

  6. Mortality rates of pathogen indicator microorganisms discharged from point and non-point sources in an urban area.

    PubMed

    Kim, Geonha; Hur, Jin

    2010-01-01

    This research measured the mortality rates of pathogen indicator microorganisms discharged from various point and non-point sources in an urban area. Water samples were collected from a domestic sewer, a combined sewer overflow, the effluent of a wastewater treatment plant, and an urban river. Mortality rates of indicator microorganisms in sediment of an urban river were also measured. Mortality rates of indicator microorganisms in domestic sewage, estimated by assuming first order kinetics at 20 degrees C were 0.197 day(-1), 0.234 day(-1), 0.258 day(-1) and 0.276 day(-1) for total coliform, fecal coliform, Escherichia coli, and fecal streptococci, respectively. Effects of temperature, sunlight irradiation and settlement on the mortality rate were measured. Results of this research can be used as input data for water quality modeling or can be used as design factors for treatment facilities. PMID:20923108

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  9. Estimation of nonpoint source loadings of phosphorus for lakes in the Puget Sound region, Washington

    USGS Publications Warehouse

    Gilliom, Robert J.

    1983-01-01

    Control of eutrophication of lakes in watersheds undergoing development is facilitated by estimates of the amounts of phosphorus (P) that reach the lakes from areas under various types of land use. Using a mass-balance model, the author calculated P loadings from present-day P concentrations measured in lake water and from other easily measured physical characteristics in a total of 28 lakes in drainage basins that contain only forest and residential land. The loadings from background sources (forest-land drainage and bulk precipitation) to each of the lakes were estimated by methods developed in a previous study. Differences between estimated present-day P loadings and loadings from background sources were attributed to changes in land use. The mean increase in annual P yield resulting from conversion of forest to residential land use was 7 kilograms per square kilometer, not including septic tank system contributions. Calculated loadings from septic systems were found to correlate best with the number of near-shore dwellings around each lake in 1940. The regression equation expressing this relationship explained 36 percent of the sample variance. There was no significant correlation between estimated septic tank system P loadings and number of dwellings present in 1960 or 1970. The evidence indicates that older systems might contribute more phosphorus to lakes than newer systems, and that there may be substantial time lags between septic system installation and significant impacts on lake-water P concentrations. For lakes in basins that contain agricultural land, the P loading attributable to agriculture can be calculated as the difference between the estimated total loading and the sum of estimated loadings from nonagricultural sources. A comprehensive system for evaluating errors in all loading estimates is presented. The empirical relationships developed allow preliminary approximations of the cumulative impact development has had on P loading and the amounts

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

    PubMed

    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. PMID:21546052

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

    PubMed

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

    2012-08-15

    To better understand the spatial dynamics of non-point source (NPS) phosphorus loading with soil property at watershed scale, integrated modeling and soil chemistry is crucial to ensure that the indicator is functioning properly and expressing the spatial interaction at two depths. Developments in distributed modeling have greatly enriched the availability of geospatial data analysis and assess the NPS pollution loading response to soil property over larger area. The 1.5 km-grid soil sampling at two depths was analyzed with eight parameters, which provided detailed spatial and vertical soil data under four main types of landuses. The impacts of landuse conversion and agricultural practice on soil property were firstly identified. Except for the slightly bigger total of potassium (TK) and cadmium (Cr), the other six parameters had larger content in 20-40 cm surface than the top 20 cm surface. The Soil and Water Assessment Tool was employed to simulate the loading of NPS phosphorus. Overlaying with the landuse distribution, it was found that the NPS phosphorus mainly comes from the subbasins dominated with upland and paddy rice. The linear correlations of eight soil parameters at two depths with NPS phosphorus loading in the subbasins of upland and paddy rice were compared, respectively. The correlations of available phosphorus (AP), total phosphorus (TP), total nitrogen (TN) and TK varied in two depths, and also can assess the loading. The soil with lower soil organic carbon (SOC) presented a significant higher risk for NPS phosphorus loading, especially in agricultural area. The Principal Component Analysis showed that the TP and zinc (Zn) in top soil and copper (Cu) and Cr in subsurface can work as indicators. The analysis suggested that the application of soil property indicators is useful for assessing NPS phosphorus loss, which is promising for water safety in agricultural area. PMID:22771816

  12. Analysis of non-point and point source pollution in China: case study in Shima Watershed in Guangdong Province

    NASA Astrophysics Data System (ADS)

    Fang, Huaiyang; Lu, Qingshui; Gao, Zhiqiang; Shi, Runhe; Gao, Wei

    2013-09-01

    China economy has been rapidly increased since 1978. Rapid economic growth led to fast growth of fertilizer and pesticide consumption. A significant portion of fertilizers and pesticides entered the water and caused water quality degradation. At the same time, rapid economic growth also caused more and more point source pollution discharge into the water. Eutrophication has become a major threat to the water bodies. Worsening environment problems forced governments to take measures to control water pollution. We extracted land cover from Landsat TM images; calculated point source pollution with export coefficient method; then SWAT model was run to simulate non-point source pollution. We found that the annual TP loads from industry pollution into rivers are 115.0 t in the entire watershed. Average annual TP loads from each sub-basin ranged from 0 to 189.4 ton. Higher TP loads of each basin from livestock and human living mainly occurs in the areas where they are far from large towns or cities and the TP loads from industry are relatively low. Mean annual TP loads that delivered to the streams was 246.4 tons and the highest TP loads occurred in north part of this area, and the lowest TP loads is mainly distributed in middle part. Therefore, point source pollution has much high proportion in this area and governments should take measures to control point source pollution.

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

    USGS Publications Warehouse

    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.

  14. Assessment of nonpoint-source nutrient discharges from the Switzer Creek basin, Steuben County, New York

    USGS Publications Warehouse

    Sherwood, D.A.

    1984-01-01

    Switzer Creek, tributary to the upper Susquehanna River basin, drains a 3.55 sq mi watershed that is 51% agricultural and 49% forested. From November 1978 to September 1980, Switzer Creek discharged 1,000 tons of suspended sediment, or 0.44 tons/acre. The maximum instantaneous suspended sediment concentration of 3 ,840 mg/L occurred during high water on September 14, 1979. Nitrogen loads, composed of nitrite plus nitrate total kjeldahl nitrogen, totaled 11 and 3.5 pounds/acre, respectively. Eighty percent of the total nitrogen load was transported during base flow. Of the nitrogen load transported during base flow, 88% was nitrite plus nitrate; of the total nitrogen load transported during high flows, 85% was organic nitrogen. Nearly 90% of the phosphorus load was transported during high flows as a result of its affinity for particulate matter. The load of total phosphorus as P totaled 0.63 pounds/acre, and total orthophosphorus as P totaled 0.19 pounds/acre. Nitrite plus nitrate from atmospheric sources totaled 8.4 pounds/acre, and ammonium totaled 3.9 pounds/acre. Equations relate streamflow to concentration and load of eight selected nutrients. (USGS)

  15. 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

    NASA Astrophysics Data System (ADS)

    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

  16. Impact of discharges from point and nonpoint sources on water quality of the upper Reedy River near Greenville, South Carolina

    USGS Publications Warehouse

    Cahal, D.I.; Speiran, G.K.

    1983-01-01

    Impacts of discharge from nonpoint sources in the urban area of Greenville, South Carolina and from the point source, the Mauldin Road Wastewater Treatment Plant, on water quality of the Reedy River were studied from October 1979 through September 1980. Streamflow and water-quality data were collected before and during two storms. The pH and concentrations of organic nitrogen, ammonium, nitrate plus nitrate, ultimate carbonaceous biochemical oxygen demand, dissolved oxygen, and orthophosphate were determined. Streamflow and concentrations of dissolved oxygen were measured continuously at three stations from May through September 1980. Discharge from the point source resulted in average daily concentrations of dissolved oxygen less than 5 milligrams per liter in the Reedy River on 34 days during low streamflow in the summer of 1980. During periods of high streamflow that resulted from the two storms. Dissolved oxygen remained at about 5 milligrams per liter in the Reedy River because increased dilution of loads of oxygen-demanding materials reduced the impacts of these loads on the quality of the Reedy River. (USGS)

  17. A review of vegetated buffers and a meta-analysis of their mitigation efficacy in reducing non-point source pollution

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Liu, X.; Zhang, M.; Dahlgren, R. A.; Eitzel, M.

    2009-12-01

    Vegetated buffers are a well-studied and widely used agricultural management practice for reducing non-point source pollution. A wealth of literature provides experimental data on their mitigation efficacy. This paper aggregated many of these results and performed a meta-analysis to quantify the relationships between pollutant removal efficacy and buffer width, buffer slope, soil type, and vegetation type. Theoretical models for removal efficacy (Y) vs. buffer width (w) were derived and tested against data from the surveyed literature using statistical analyses. A model of the form Y = K x (1-exp(-b x w) , (0< K <= 100) successfully captured the relationship between buffer width and pollutant removal, where K reflects the maximum removal efficacy of the buffer and b reflects its probability to remove any single particle of pollutant in a unit distance. The estimates of K were 90.9, 93.2, 92.0, and 89.5 for sediment, pesticides, nitrogen (N) and phosphorus (P), respectively. Buffer width alone explains 37, 60, 44 and 35% of the total variance in removal efficacy for sediment, pesticides, N and P, respectively. Buffer slope was linearly associated with sediment removal efficacy either positively (when slope ≤ 10%) or negatively (when slope > 10%). Buffers composed of trees have higher N and P removal efficacy than buffers composed of grasses or mixtures of grasses and trees. Soil drainage type did not show a significant effect on pollutant removal efficacy. Models for all the studied pollutants were statistically significant with P-values < 0.001. Based on our analysis, a 30 m buffer under favorable slope conditions (≈ 10%) removes over 85% of all the studied pollutants. These models predicting optimal buffer width/slope can be instrumental in the design, implementation and modeling of vegetated buffers for treating agricultural runoff.

  18. Reconstructing historical changes in phosphorus inputs to rivers from point and nonpoint sources in a rapidly developing watershed in eastern China, 1980-2010.

    PubMed

    Chen, Dingjiang; Hu, Minping; Guo, Yi; Dahlgren, Randy A

    2015-11-15

    Quantifying point (PS) and nonpoint source (NPS) phosphorus inputs to rivers is critical for developing effective watershed remediation strategies. This study reconstructed PS and NPS total phosphorus (TP) inputs to the Yongan River in eastern China in 1980-2010 using a load apportionment model (LAM) from paired riverine TP concentrations and river discharge records. Based on the fundamental hydrological differences between PS and NPS pollution, the LAM statistically quantified their individual inputs as a power-law function of river discharge. The LAM-estimated monthly/annual riverine TP loads were in good agreement with results derived from a regression model, Load Estimator (LOADEST). The annual TP load increased from 18.4 to 357.0 Mg yr(-1) between 1980 and 2010. The PS input contributed 7-45% of annual total TP load and increased 23-fold, consistent with a 20-fold increase in flow-adjusted average chloride concentration during the low flow regime (a proxy for wastewater inputs), as well as measured increases in population, poultry, and industrial production. Inferring from observed TP and chloride ratios, as well as total suspended solids (TSS) and river discharge dynamics, temporally retained P load within the river during the low flow regime was estimated to contribute 18-65% of the annual PS input load. NPS inputs consistently dominated the annual riverine TP load (55-93%) and increased 19-fold, consistent with the strong correlation between riverine TP and TSS concentrations, increasing developed land area, improved agricultural drainage systems, and phosphorus accumulation in agricultural soils. Based on our analysis, TP pollution control strategies should be preferentially directed at reductions in NPS loads, especially during summer high-flow periods when the greatest eutrophication risk occurs. PMID:26163441

  19. Assessment of the Impacts of Land Use Changes on Nonpoint Source Pollution Inputs Upstream of the Three Gorges Reservoir

    PubMed Central

    Yang, Huicai; 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 = b0 + ∑i=1mbiXi. 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. PMID:24977205

  20. Effects of specific land uses on nonpoint sources of suspended sediment, nutrients, and herbicides, Pequea Creek basin, Pennsylvania, 1979-80

    USGS Publications Warehouse

    Lietman, P.L.; Ward, J.R.; Behrendt, T.E.

    1983-01-01

    The Susquehanna River Basin Commission and the U.S. Environmental Protection Agency cooperated with the U.S. Geological Survey in a study to quantify nonpoint-source loadings from an agricultural area in Pennsylvania. Pequea Creek, a tributary to the Susquehanna River, drains a 154-square mile agricultural area in Lancaster County, Pennsylvania. Previous studies defined the Pequea Creek basin as a contributor of sediment, nutrients, and pesticides from nonpoint sources to the Susquehanna River. The purpose of this intensive watershed investigation was to determine the effects of various land uses on water quality of receiving streams. Streamflow was measured and monthly base-flow samples and water-weighted composite storm samples were analyzed for suspended sediment, nutrients, organic carbon, and triazine herbicides. Constituent loadings were calculated to quantify their discharge from the entire Pequea Creek basin and from four specific subbasins: forest, cornfield, rural residential, and pasture. Soil samples were analyzed for nutrients and selected herbicides, and land use and application data were collected to determine the source of loadings. Precipitation amounts and chemistry were also measured. Precipitation and streamflow were below average for much of the investigation period, May 1979 to December 1980. The annual precipitation for 1980 was 10 inches below normal, with drought conditions the last half of the year. During base flow, the highest concentrations of individual constituents generally observed were: 4.0 milligrams per liter total organic nitrogen and 1.4 milligrams per liter total phosphorus from the downstream pasture site; 24 milligrams per liter total nitrate nitrogen and 3.9 micrograms per liter total atrazine from the cornfield site; and 0.5 micrograms per liter total prometone, and 2.3 micrograms per liter total simazine from the residential site. Nearly all total nitrate nitrogen concentrations from the cornfield site during base flow

  1. In-situ treatment of non-point source pollution part 1: Concepts and chemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The loss of nutrients, particularly phosphorus (P), in agricultural and urban/suburban drainage waters is a priority conservation concern. Although several best management practices are effective in preventing particulate P losses to surface waters, they are less effective on dissolved P losses. Op...

  2. METHODOLOGY FOR EVALUATING THE EFFECTIVENESS OF NONPOINT SOURCE POLLUTION ABATEMENT PROGRAMS

    EPA Science Inventory

    The Upper Big Walnut Creek watershed encompasses 190 square miles of predominantly agricultural cropland (65%) in Central Ohio (USA) where agronomic fertilizers and herbicides are used in row crop production. Runoff from the watershed drain to Hoover Reservoir which is Central Oh...

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

    PubMed

    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. PMID:20830927

  4. Influencing factor analysis of phosphorus loads from non-point source: a case study in central China.

    PubMed

    Zhuang, Yanhua; Hong, Song; Zhan, F Benjamin; Zhang, Liang

    2015-11-01

    The influence factor analysis for non-point source (NPS) pollution is very important to taking effective water pollution control measures. In this study, the self-organizing map (SOM) and linear model analysis were used to analyze the relationships between total phosphorus (TP) loads and influencing factors, both qualitatively and quantitatively. The land-use type, topography, and vegetation coverage were the main factors influencing the export of TP loads in Tangxun watershed. Slope and normalized difference vegetation index (NDVI) were chosen as characteristic indices of topography and vegetation coverage, respectively. For the whole watershed, the high TP loads were mainly distributed in areas with high slope and low vegetation coverage for a specific land-use type. For different land types, the slope significantly influenced the export of TP loads in waste/bare land and forest/green land while NDVI influenced the export of TP loads in forest/green land and farmland. In terms of multi-factor analysis, the comprehensive influence of slope and NDVI on TP loads showed as waste/bare land>forest/green land>farmland>rural/urban construction land. PMID:26514801

  5. Understanding enabling capacities for managing the 'wicked problem' of nonpoint source water pollution in catchments: a conceptual framework.

    PubMed

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

    2013-10-15

    Nonpoint source (NPS) water pollution in catchments is a 'wicked' problem that threatens water quality, water security, ecosystem health and biodiversity, and thus the provision of ecosystem services that support human livelihoods and wellbeing from local to global scales. However, it is a difficult problem to manage because water catchments are linked human and natural systems that are complex, dynamic, multi-actor, and multi-scalar in nature. This in turn raises questions about understanding and influencing change across multiple levels of planning, decision-making and action. A key challenge in practice is enabling implementation of local management action, which can be influenced by a range of factors across multiple levels. This paper reviews and synthesises important 'enabling' capacities that can influence implementation of local management action, and develops a conceptual framework for understanding and analysing these in practice. Important enabling capacities identified include: history and contingency; institutional arrangements; collaboration; engagement; vision and strategy; knowledge building and brokerage; resourcing; entrepreneurship and leadership; and reflection and adaptation. Furthermore, local action is embedded within multi-scalar contexts and therefore, is highly contextual. The findings highlight the need for: (1) a systemic and integrative perspective for understanding and influencing change for managing the wicked problem of NPS water pollution; and (2) 'enabling' social and institutional arenas that support emergent and adaptive management structures, processes and innovations for addressing NPS water pollution in practice. These findings also have wider relevance to other 'wicked' natural resource management issues facing similar implementation challenges. PMID:23792915

  6. The Behavior of Organic Phosphorus under Non-Point Source Wastewater in the Presence of Phototrophic Periphyton

    PubMed Central

    Lu, Haiying; Yang, Linzhang; Zhang, Shanqing; Wu, Yonghong

    2014-01-01

    To understand the role of ubiquitous phototrophic periphyton in aquatic ecosystem on the biogeochemical cycling of organic phosphorus, the conversion and removal kinetic characteristics of organic phosphorus (Porg) such as adenosine triphosphate (ATP) were investigated in the presence of the periphyton cultured in artificial non-point source wastewater. The preliminary results showed that the periphyton was very powerful in converting Porg evidenced by the fact that inorganic phosphorus (Pinorg) content in solution increased from about 0.7 to 14.3 mg P L−1 in 48 hours in the presence of 0.6 g L−1 periphyton. This was because the periphyton could produce abundant phosphatases that benefited the conversion of Porg to Pinrog. Moreover, this conversion process was described more suitable by the pseudo-first-order kinetic model. The periphyton was also effective in removing Porg, which showed that the Porg can be completely removed even when the initial Porg concentration was as high as 13 mg P L−1 in 48 hours in the presence of 1.6 g L−1 periphyton. Furthermore, it was found that biosorption dominated the Porg removal process and exhibited the characteristics of physical adsorption. However, this biosorption process by the periphyton was significantly influenced by biomass (absorbent dosage) and temperature. This work provides insights into Porg biogeochemical circulation of aquatic ecosystem that contained the periphyton or similar microbial aggregates. PMID:24465782

  7. Evaluation of the AnnAGNPS model for predicting runoff and sediment yield in a small Mediterranean agricultural watershed in Navarre (Spain)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    AnnAGNPS (Annualized Agricultural Non-Point Source Pollution Model) is a system of computer models developed to predict non-point source pollutant loadings within agricultural watersheds. It contains a daily time step distributed parameter continuous simulation surface runoff model designed to assis...

  8. Measurement and modeling of bentazone in the river Main (Germany) originating from point and non-point sources.

    PubMed

    Bach, M; Letzel, M; Kaul, U; Forstner, S; Metzner, G; Klasmeier, J; Reichenberger, S; Frede, H G

    2010-06-01

    A Water Framework Directive pilot project combines measured data and model approaches to calculate fluxes and mass balance of the pesticide bentazone in an 81 km section of the river Main (Germany). During the study period (six weeks in spring 2004) the observed bentazone inflow and outflow in the river section amounted to 52.8 and 53.1 kg, respectively; the maximum concentrations reached 220 and 290 ng l(-1). Based on sampling of seven sewage treatment plants a specific loss of 0.87 g bentazone per farm was calculated. Extrapolation to the entire sub-basin results in 2.6 kg bentazone in total as point source contribution from farms. Diffuse input into the surface water network occurred after an intensive rainfall event on May 7th. Total bentazone load was simulated with the pesticide emission model DRIPS to be 23.2 kg. One third of this load was estimated to be degraded by photolysis before reaching the main waterway, the river Main. The ATV water quality model was applied to predict the concentration profile of bentazone in river Main between Schweinfurt and Würzburg with reasonable results. The difference between total measured and modeled fluxes amounted to 1.5 kg corresponding to 2% of the overall input. The combined approach of monitoring and modeling appears to be a valuable strategy to quantify the relevance of point and non-point sources and to focus effective mitigation measures to the most relevant origins within a river basin. PMID:20546837

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

    EPA Science Inventory

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

  10. Opening the black box: evaluation of nutrient nonpoint source management for estuarine watersheds

    EPA Science Inventory

    Over the last 40 years, there have been significant improvements in water quality and ecosystem condition in estuaries stressed by nutrient enrichment. However, documented improvements have been largely attributed to reductions in point sources. In contrast, improvement of coasta...

  11. Synergistic impacts of land-use change and soil property variation on non-point source nitrogen pollution in a freeze-thaw area

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    Quantifying the non-point source (NPS) nitrogen pollution response to the varied land-use and soil properties in highly agricultural regions is critical for the proper management of NPS pollution. This study simulated the NPS nitrogen loading responses to variations of land-use and soil from 1979 to 2009. The Soil and Water Assessment Tool (SWAT) was used to model the NPS organic nitrogen and nitrate loading in a freeze-thaw area in northeast China. The temporal-spatial simulations of land-use in four periods indicated that the NPS nitrogen loading responded to the disappearance of wetlands and the conversion of uplands to paddy rice. After updating the soil data, the watershed NPS nitrogen loading decreased, and the spatial distribution of the loading indicated that the NPS organic nitrogen was more sensitive than was the nitrate to soil variation. F-tests were employed to assess the significance of each of the predictor variables in five types of scenarios. Overall, the results indicate that the watershed NPS nitrogen loading is sensitive to changes of soil and land-use, but soil changes have a more significant impact. The results of this study also suggest that temperature has significant effects on NPS nitrogen yield and that it caused the twin peaks in the temporal scale. Increasing the temperature above zero in April caused a temporal shift in soil water movement and transported nitrogen pollution earlier in the year, causing an increased loading in water before the summer irrigation, which is advantageous for NPS nitrogen pollution control.

  12. Preliminary study on using rare earth elements to trace non-point source phosphorous loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The environmental fate of phosphorus (P) is of concern as P is a primary cause of freshwater eutrophication. Rare earth elements (REEs) have been successfully used in the analysis of soil erosion and pollutant sources, as well as in the analysis of mineral genesis. To better understand the potential...

  13. Emerging technologies to remove nonpoint phosphorus sources from surface water and groundwater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New innovative remediation practices are currently being developed that address phosphorus transfers from soils and applied sources to surface and ground waters. These practices include reactive barriers placed along field ditches and drainage ways, retention filters at the end of tile drains, mater...

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

    PubMed

    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. PMID:25960014

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Use of Antibiotic Resistance Analysis To Identify Nonpoint Sources of Fecal Pollution

    PubMed Central

    Wiggins, B. A.; Andrews, R. W.; Conway, R. A.; Corr, C. L.; Dobratz, E. J.; Dougherty, D. P.; Eppard, J. R.; Knupp, S. R.; Limjoco, M. C.; Mettenburg, J. M.; Rinehardt, J. M.; Sonsino, J.; Torrijos, R. L.; Zimmerman, M. E.

    1999-01-01

    A study was conducted to determine the reliability and repeatability of antibiotic resistance analysis as a method of identifying the sources of fecal pollution in surface water and groundwater. Four large sets of isolates of fecal streptococci (from 2,635 to 5,990 isolates per set) were obtained from 236 samples of human sewage and septage, cattle and poultry feces, and pristine waters. The patterns of resistance of the isolates to each of four concentrations of up to nine antibiotics were analyzed by discriminant analysis. When isolates were classified individually, the average rate of correct classification (ARCC) into four possible types (human, cattle, poultry, and wild) ranged from 64 to 78%. When the resistance patterns of all isolates from each sample were averaged and the resulting sample-level resistance patterns were classified, the ARCCs were much higher (96 to 100%). These data confirm that there are measurable and consistent differences in the antibiotic resistance patterns of fecal streptococci isolated from various sources of fecal pollution and that antibiotic resistance analysis can be used to classify and identify these sources. PMID:10427038

  17. Annual precipitation and effects of runoff-nutrient from agricultural watersheds on water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Declining surface water quality from agricultural nonpoint sources is of great concern across the Platte river basin in Nebraska. Recent changes in the earth climate create abrupt changes in domestic weather (i.e., precipitation, temperature, etc.) which can alter the impact of these nonpoint source...

  18. AN APPLICATION OF GIS BASED NONPOINT SOURCE MODELING TO LITTLE MIAMI RIVER BASIN: PRACTICE AND EXPERIENCE USING BASINS

    EPA Science Inventory

    Water quality has improved significantly in the Little Miami River Basin, OH, over the past few decades because of improvements in the treatment of municipal and industrial wastes. However, water quality modeling is necessary to assess the relative impacts of point and nonpoint s...

  19. Evaluation and management of non-point source pollutants in the Lake Tahoe watershed

    SciTech Connect

    Lee, G.F.; Jones-Lee, A.

    1994-12-31

    Lake Tahoe, California-Nevada, one of the most oligotrophic lakes in the world, is experiencing decreased water clarity and increased periphyton growth, and water supplies drawing from the lake are experiencing increased algal-related tastes and odors. The growth of algae in Lake Tahoe is primarily limited by the nitrogen (nitrate and ammonia) loads to the lake, which have been increasing over the years. The nitrogen that is causing the increased fertilization of the lake is primarily derived from atmospheric sources through precipitation onto the lake`s surface. A potentially highly significant source of atmospheric nitrogen in the Lake Tahoe Basin is automobile, bus, and truck engine exhaust discharge of NOx. The fertilization of lawns and other shrubbery, including golf courses, within the Lake Tahoe Basin is also leading to significant growths of attached algae in the nearshore waters of the lake. The fertilizers are transported via groundwater to the nearshore areas of the lake. In order to prevent further deterioration of Lake Tahoe`s eutrophication-related water quality, there is immediate need to control atmospheric input of nitrate and ammonia to the lake`s surface, and to control use of fertilizers on lawns, shrubbery, and golf courses in the watershed. The states of California and Nevada, and the Tahoe Regional Planning Authority need to focus considerable attention on the determination of whether restricting NOx emissions from vehicular traffic within the basin would have a significant beneficial impact on Lake Tahoe`s water clarity.

  20. METHODOLOGY FOR EVALUATING THE EFFECTIVENESS OF WATERSHED-SCALE NON-POINT SOURCE CONTROL BMPS FOR ATRAZINE

    EPA Science Inventory

    Atrazine is listed on the Contaminant Candidate List (CCL). The Upper Big Walnut Creek watershed in central Ohio covers approximately 190 square miles of mostly agricultural land that drains into Hoover Reservoir, providing a source of drinking water for nearly one million people...

  1. Identifying non-point sources of endocrine active compounds and their biological impacts in freshwater lakes.

    PubMed

    Baker, Beth H; Martinovic-Weigelt, Dalma; Ferrey, Mark; Barber, Larry B; Writer, Jeffery H; Rosenberry, Donald O; Kiesling, Richard L; Lundy, James R; Schoenfuss, Heiko L

    2014-10-01

    Contaminants of emerging concern, particularly endocrine active compounds (EACs), have been identified as a threat to aquatic wildlife. However, little is known about the impact of EACs on lakes through groundwater from onsite wastewater treatment systems (OWTS). This study aims to identify specific contributions of OWTS to Sullivan Lake, Minnesota, USA. Lake hydrology, water chemistry, caged bluegill sunfish (Lepomis macrochirus), and larval fathead minnow (Pimephales promelas) exposures were used to assess whether EACs entered the lake through OWTS inflow and the resultant biological impact on fish. Study areas included two OWTS-influenced near-shore sites with native bluegill spawning habitats and two in-lake control sites without nearby EAC sources. Caged bluegill sunfish were analyzed for plasma vitellogenin concentrations, organosomatic indices, and histological pathologies. Surface and porewater was collected from each site and analyzed for EACs. Porewater was also collected for laboratory exposure of larval fathead minnow, before analysis of predator escape performance and gene expression profiles. Chemical analysis showed EACs present at low concentrations at each study site, whereas discrete variations were reported between sites and between summer and fall samplings. Body condition index and liver vacuolization of sunfish were found to differ among study sites as did gene expression in exposed larval fathead minnows. Interestingly, biological exposure data and water chemistry did not match. Therefore, although results highlight the potential impacts of seepage from OWTS, further investigation of mixture effects and life history factor as well as chemical fate is warranted. PMID:24974177

  2. A coupled stochastic inverse-management framework for dealing with nonpoint agriculture pollution under groundwater parameter uncertainty

    NASA Astrophysics Data System (ADS)

    Llopis-Albert, Carlos; Palacios-Marqués, Daniel; Merigó, José M.

    2014-04-01

    In this paper a methodology for the stochastic management of groundwater quality problems is presented, which can be used to provide agricultural advisory services. A stochastic algorithm to solve the coupled flow and mass transport inverse problem is combined with a stochastic management approach to develop methods for integrating uncertainty; thus obtaining more reliable policies on groundwater nitrate pollution control from agriculture. The stochastic inverse model allows identifying non-Gaussian parameters and reducing uncertainty in heterogeneous aquifers by constraining stochastic simulations to data. The management model determines the spatial and temporal distribution of fertilizer application rates that maximizes net benefits in agriculture constrained by quality requirements in groundwater at various control sites. The quality constraints can be taken, for instance, by those given by water laws such as the EU Water Framework Directive (WFD). Furthermore, the methodology allows providing the trade-off between higher economic returns and reliability in meeting the environmental standards. Therefore, this new technology can help stakeholders in the decision-making process under an uncertainty environment. The methodology has been successfully applied to a 2D synthetic aquifer, where an uncertainty assessment has been carried out by means of Monte Carlo simulation techniques.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. NONPOINT SOURCE POLLUTION IMPACTS OF ALTERNATIVE AGRICULTURAL MANAGEMENT PRACTICES IN ILLINOIS: A SIMULATION STUDY

    EPA Science Inventory

    The 1987 National Resources Inventory (NRI) was used to provide a random sample of 100 Illinois cropland sites growing corn and soybeans. hese were used with the Erosion Productivity Impact Calculator (EPIC) model to examine responses of soil erosion and nutrient exports to diffe...

  5. The implementation of the new Kentucky nitrogen and phosphorus index to reduce agricultural nonpoint source pollution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new study released in September 2011 by the USDA found that all of three best management practices (BMPs) for nitrogen in terms of application rate, time, and method, are done for only about a third of U.S. cropland (http://www.ers.usda.gov/Publications/ERR127/). Without BMPs, the potential for ni...

  6. Secondary nitrogen limitation in a subtropical lake impacted by non-point source agricultural pollution.

    PubMed

    Havens, K E

    1995-01-01

    A 20-year history of nutrient limitation was quantified for Lake Okeechobee, a nutrient-impacted lake in Florida, USA. Limiting status (nitrogen versus phosphorus) was estimated from deviations between trophic state index (TSI) parameters, calculated from routine monitoring data. The lake is presently nitrogen-limited. However, historical trends in the TSI deviations indicate that contemporary nitrogen limitation is a secondary, unnatural condition that has arisen due to excessive phosphorus loading. Prior to 1980, there was evidence of lake-wide limitation by phosphorus, rather than nitrogen. The finding of secondary nitrogen limitation in Lake Okeechobee has important management implications. Phosphorus loads are presently being reduced in order to reduce in-lake concentrations and create phosphorus-limited conditions (nitrogen limitation is undersirable because it has favored bloom-forming cyanobacteria). The present results indicate that this long-term management goal is ecologically sound; it is consistent with the concept of restoration of the lake. PMID:15091513

  7. Runoff characteristics and non-point source pollution analysis in the Taihu Lake Basin: a case study of the town of Xueyan, China.

    PubMed

    Zhu, Q D; Sun, J H; Hua, G F; Wang, J H; Wang, H

    2015-10-01

    Non-point source pollution is a significant environmental issue in small watersheds in China. To study the effects of rainfall on pollutants transported by runoff, rainfall was monitored in Xueyan town in the Taihu Lake Basin (TLB) for over 12 consecutive months. The concentrations of different forms of nitrogen (N) and phosphorus (P), and chemical oxygen demand, were monitored in runoff and river water across different land use types. The results indicated that pollutant loads were highly variable. Most N losses due to runoff were found around industrial areas (printing factories), while residential areas exhibited the lowest nitrogen losses through runoff. Nitrate nitrogen (NO3-N) and ammonia nitrogen (NH4-N) were the dominant forms of soluble N around printing factories and hotels, respectively. The levels of N in river water were stable prior to the generation of runoff from a rainfall event, after which they were positively correlated to rainfall intensity. In addition, three sites with different areas were selected for a case study to analyze trends in pollutant levels during two rainfall events, using the AnnAGNPS model. The modeled results generally agreed with the observed data, which suggests that AnnAGNPS can be used successfully for modeling runoff nutrient loading in this region. The conclusions of this study provide important information on controlling non-point source pollution in TLB. PMID:26002368

  8. Preliminary preview for a geographic and monitoring program project; a review of point source-nonpoint source effluent trading/offset systems in watersheds

    USGS Publications Warehouse

    Wood, Alexander Warren; Bernknopf, Richard L.

    2003-01-01

    Watershed-based trading and offset systems are being developed to improve policy-maker?s and regulator?s ability to assess nonpoint source impacts in watersheds and to evaluate the efficacy of using market-incentive programs for preserving environmental quality. An overview of the history of successful and failed trading programs throughout the United States suggests that certain political, economic, and scientific conditions within a temporal and spatial setting help meet water quality standards. The current lack of spontaneous trading among dischargers does not mean that a marketable permit trading system is an inherently inefficient regulatory approach. Rather, its infrequent use is the result of institutional and informational barriers. Improving and refining the earth science information and technologies may help determine whether trading is a suitable policy for improving water quality. However, it is debatable whether or not environmental information is the limiting factor. This paper reviews additional factors affecting the potential for instituting a trading policy. The motivation for investigating and reviewing the history of offsets and trading was inspired by a project in the preliminary stages being developed by U.S. Geological Survey Western Geographic Science Center and the Environmental Protection Agency Region IX. An offset feasibility study will be an integrated, map-based approach that incorporates environmental, economic, and statistical information to investigate the potential for using offsets to meet mercury Total Maximum Daily Loads in the Sacramento River watershed. A regional water-quality offset program is being studied that may help known point sources reduce mercury loading more cost effectively by the remediation of abandoned mines or other diffuse sources as opposed to more costly treatment at their own sites. An efficient offset program requires both a scientific basis and methods to translate that science into a regulatory decision

  9. [Ecological mechanisms of the effects of vegetation restoration on the controls of non-point source pollution on barren tableland in Dianchi Watershed of China].

    PubMed

    Wang, Zhen-Hong; Wu, Xue-Can; Li, Ying-Nan

    2006-01-01

    Surface runoff, soil erosion and the leaching of the different forms of nitrogen and phosphorus were observed and the hygroscopic volume of branch and leaves of all plant species and soil penetration were determined to understand the ecological mechanisms of the effects of vegetation restoration on the controls of non-point source pollution on barren tableland in Dianchi Watershed of China. Results indicated that there were significantly relationships between surface runoff volume and the output of non-point pollution matters. The different manmade vegetation systems, consisted respectively of A. nepalensis, A. mearnsii, R. pseudoacacia and V. zizanioides clump, had shown the different potentials to control the leaching of TN, TP, soluble TP, soluble TN. Strong hygroscopic functions of leaves and branch was able to promote the interception of rainfalls and give rise to the less of surface runoff. The leaves, that were small, with low water content, no leathery and have rough face and epidermal wools, were able to got the highly ratio of the hygroscopic volume to above ground fresh standing crops and strengthened the interception of forest canopy. Preparing soil, growth of root system of plant and the natural recovery of vegetation at the gap of trees enhanced surface runoff penetration, as lightened the surface runoff leaching the different forms of nitrogen, phosphorus of soil on the stands. The leaching of different forms of nitrogen and phosphorus went down with the controls of surface runoff in different stands as well. PMID:16599117

  10. Monitoring coastal marine waters for spore-forming bacteria of faecal and soil origin to determine point from non-point source pollution.

    PubMed

    Fujioka, R S

    2001-01-01

    The US Environmental Protection Agency (USEPA) and the World Health Organization (WHO) have established recreational water quality standards limiting the concentrations of faecal indicator bacteria (faecal coliform, E. coli, enterococci) to ensure that these waters are safe for swimming. In the application of these hygienic water quality standards, it is assumed that there are no significant environmental sources of these faecal indicator bacteria which are unrelated to direct faecal contamination. However, we previously reported that these faecal indicator bacteria are able to grow in the soil environment of humid tropical island environments such as Hawaii and Guam and are transported at high concentrations into streams and storm drains by rain. Thus, streams and storm drains in Hawaii contain consistently high concentrations of faecal indicator bacteria which routinely exceed the EPA and WHO recreational water quality standards. Since, streams and storm drains eventually flow out to coastal marine waters, we hypothesize that all the coastal beaches which receive run-off from streams and storm drains will contain elevated concentrations of faecal indicator bacteria. To test this hypothesis, we monitored the coastal waters at four beaches known to receive water from stream or storm drains for salinity, turbidity, and used the two faecal indicator bacteria (E. coli, enterococci) to establish recreational water quality standards. To determine if these coastal waters are contaminated with non-point source pollution (streams) or with point source pollution (sewage effluent), these same water samples were also assayed for spore-forming bacteria of faecal origin (Cl. perfringens) and of soil origin (Bacillus species). Using this monitoring strategy it was possible to determine when coastal marine waters were contaminated with non-point source pollution and when coastal waters were contaminated with point source pollution. The results of this study are most likely

  11. Agricultural drainage ditches mitigate phosphorus loads as a function of hydrological variability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphorus loading from non-point sources such as agricultural landscapes contributes to downstream aquatic ecosystem degradation. Specifically within the Mississippi watershed, enriched runoff contributions have far reaching consequences for coastal water eutrophication and Gulf of Mexico hypoxia. ...

  12. Mitigation efficacy of vegetated buffers in reducing non-point source pollution: A critical review and meta-analysis

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Liu, X.; Zhang, M.; Dahlgren, R.; Eitzel, M.

    2008-12-01

    Vegetated buffers are the most studied and widely used agricultural management practice for reducing non- point source pollution. A wealth of existing literature provides experimental data on their mitigation efficacy. This paper aggregated many of these results and performed a meta-analysis on them to quantify the relationships between pollutant removal efficacy and buffer width and buffer slope. Theoretical models for removal efficacy (Y) vs. buffer width (w) were derived and tested against data from the surveyed literature using statistical analyses. A model of the form \\Y = K (1 - exp (-bw)) , (0< K ≤100) is shown to successfully capture the relationship between buffer width and pollutant removal, where K reflects the removal capacity of the buffer and b reflects its probability to remove any single particle of pollutant in a unit distance. The estimates of K are 90.9, 93.2, 92.0, and 89.5 for sediment, pesticides, nitrogen (N) and phosphorus (P), respectively. Buffer width alone explains 37, 60, 44 and 35% of the total variance in removal efficacy for sediment, pesticides, N and P. Buffer slope is linearly associated with sediment removal efficacy either positively (when slope ≤9%) or negatively (when slope >9%). A sediment removal model based on buffer width and buffer slope explains 55.8% of the total variation in removal efficacy. Models for all the studied pollutants are statistically significant with P-values <0.001. Based on our analysis, a 30 m buffer removes over 80% of all the studied pollutants. These models predicting optimal buffer width/slope could be instrumental in the implementation and design of vegetated buffers for treating agricultural runoff to meet specific water quality objectives. The quantitative relationship established also provides valuable information for modeling buffer efficacy at the watershed scale.

  13. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils.

    PubMed

    Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

    2015-12-15

    Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74-100% and 0-24% of the total Hg input, while road dusts and solid wastes contributed for 0-80% and 19-100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions. PMID:26257294

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

    NASA Technical Reports Server (NTRS)

    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.

  15. The sources of deforestation - implications for sustainable agriculture in Brazil

    SciTech Connect

    Torres-Zorrilla, J.; Arnode, C.

    1992-12-01

    Agricultural equilibrium conditions are used to identify the sources of deforestation in Brazil. The rate which forestland can be converted into agricultural land and meet agricultural and environmental goals is calculated. This serves the task of determining how long agricultural land growth can be maintained until environmental targets are violated.

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    Kinner, Paul; Heiss, Gerhard; Soja, Gerhard

    2013-04-01

    Lake Neusiedl (Austria) is a mesotrophic to eutrophic shallow steppe lake. Due to its low water volume and the lack of a natural outflow, excessive nutrient input is a special risk for this lake. In recent years, improved waste water treatment technologies have reduced the N and P loads of the inflows although all municipalities surrounding Lake Neusiedl (with one exception) and the cities and municipalities within the catchment area of the river Wulka discharge their (treated) wastewater into Lake Neusiedl. The amount of wastewater in 2010 was more than 22 x 106 m3. Although the amount of wastewater increased by more than 70 % in the last 30 years, it was possible to reduce the ammonium load from 38 t/a to 8 t/a (as NH4-N), the nitrate load from 83 t/a to 34 t/a (as NO3-N), the phosphate load from 8 t/a to 3 t/a (as PO4-P) and the total phosphorus load from 11 t/a to 6 t/a (comparison of the average annual loads of 1982 and 2010). Another environmental risk for Lake Neusiedl is the nitrogen input due to agricultural activities. Therefore a pilot action within the EULAKES-project focused on the nitrate levels during annual cycles (2011-2012) in groundwater as well as in selected rivers, channels and ditches discharging into Lake Neusiedl. The monitoring programme demonstrated clearly that the major contribution of the total nitrogen load discharged by surface water into Lake Neusiedl originated from River Wulka. For a general assessment of the influence of surface water discharge into Lake Neusiedl it is necessary to investigate the data of River Wulka for a longer period. Therefore data at the monitoring station Schützen were analysed for the period 1992-2010. Evaluation of the monitoring data showed that due to the higher nitrogen concentrations at higher average annual discharges the inorganic nitrogen load was about 6.5 times higher in 2010 (average discharge of Wulka 2.1 m3/s) than in the year 2001 (average discharge of Wulka 0.56 m3/s). The total inorganic

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

    PubMed

    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. PMID:26038937

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

    USGS Publications Warehouse

    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.

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

    EPA Science Inventory

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

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

    PubMed

    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). PMID:18469404

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

    PubMed Central

    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. PMID:26267482

  3. A novel approach combining self-organizing map and parallel factor analysis for monitoring water quality of watersheds under non-point source pollution

    NASA Astrophysics Data System (ADS)

    Zhang, Yixiang; Liang, Xinqiang; Wang, Zhibo; Xu, Lixian

    2015-11-01

    High content of organic matter in the downstream of watersheds underscored the severity of non-point source (NPS) pollution. The major objectives of this study were to characterize and quantify dissolved organic matter (DOM) in watersheds affected by NPS pollution, and to apply self-organizing map (SOM) and parallel factor analysis (PARAFAC) to assess fluorescence properties as proxy indicators for NPS pollution and labor-intensive routine water quality indicators. Water from upstreams and downstreams was sampled to measure dissolved organic carbon (DOC) concentrations and excitation-emission matrix (EEM). Five fluorescence components were modeled with PARAFAC. The regression analysis between PARAFAC intensities (Fmax) and raw EEM measurements indicated that several raw fluorescence measurements at target excitation-emission wavelength region could provide similar DOM information to massive EEM measurements combined with PARAFAC. Regression analysis between DOC concentration and raw EEM measurements suggested that some regions in raw EEM could be used as surrogates for labor-intensive routine indicators. SOM can be used to visualize the occurrence of pollution. Relationship between DOC concentration and PARAFAC components analyzed with SOM suggested that PARAFAC component 2 might be the major part of bulk DOC and could be recognized as a proxy indicator to predict the DOC concentration.

  4. Effects of ecological factors and human activities on nonpoint source pollution in the upper reach of the Yangtze River and its management strategies

    NASA Astrophysics Data System (ADS)

    Ding, X. W.; Shen, Z. Y.; Liu, R. M.; Chen, L.; Lin, M.

    2014-01-01

    The effects of ecological and human activities on nonpoint source (NPS) pollution are key issues for sustainable water resources management. In this study, the Improved Export Coefficient Model and the Revised Universal Soil Loss Equation were adopted to estimate the annual loads of NPS pollutants during the period from 1960 through 2003 in the upper reach of the Yangtze River (URYR). Ecological factors and human activities affecting NPS pollution were distinguished and their respective effects were assessed. Variations of the dominant cause (between ecological factors and human activities) were presented. Furthermore, the combined effect of them on NPS pollution were successfully revealed. The results showed that the annual loads raised from ecological factors of dissolved nitrogen (DN) and dissolved phosphorus (DP) were relatively steady from 1960 to 2003. But those of sediment, absorbed nitrogen (AN) and absorbed phosphorus (AP) decreased during that period. In terms of the annual loads caused by human activities, those of dissolved pollutants increased from 1960 to 2000 and then fell. Those of sediment as well as absorbed pollutants peaked in 1980 and then decreased. Simultaneously, the dominant cause of DN loads shifted from ecological factors to human activities after 1980 while DP loads were mainly contributed by human activities. However, sediment, dissolved pollutants were primarily exported by ecological factors. Finally, strategies for managing anthropogenic activities were proposed and their effects on NPS pollution reduction were also depicted quantitatively.

  5. A novel approach combining self-organizing map and parallel factor analysis for monitoring water quality of watersheds under non-point source pollution

    PubMed Central

    Zhang, Yixiang; Liang, Xinqiang; Wang, Zhibo; Xu, Lixian

    2015-01-01

    High content of organic matter in the downstream of watersheds underscored the severity of non-point source (NPS) pollution. The major objectives of this study were to characterize and quantify dissolved organic matter (DOM) in watersheds affected by NPS pollution, and to apply self-organizing map (SOM) and parallel factor analysis (PARAFAC) to assess fluorescence properties as proxy indicators for NPS pollution and labor-intensive routine water quality indicators. Water from upstreams and downstreams was sampled to measure dissolved organic carbon (DOC) concentrations and excitation-emission matrix (EEM). Five fluorescence components were modeled with PARAFAC. The regression analysis between PARAFAC intensities (Fmax) and raw EEM measurements indicated that several raw fluorescence measurements at target excitation-emission wavelength region could provide similar DOM information to massive EEM measurements combined with PARAFAC. Regression analysis between DOC concentration and raw EEM measurements suggested that some regions in raw EEM could be used as surrogates for labor-intensive routine indicators. SOM can be used to visualize the occurrence of pollution. Relationship between DOC concentration and PARAFAC components analyzed with SOM suggested that PARAFAC component 2 might be the major part of bulk DOC and could be recognized as a proxy indicator to predict the DOC concentration. PMID:26526140

  6. Application of an index of biotic integrity for dunal, palustrine wetlands: Emphasis on assessment of nonpoint source landfill effects on the Grand Calumet Lagoons

    USGS Publications Warehouse

    Simon, T.P.; Stewart, P.M.

    1998-01-01

    Using a newly modified index of biotic integrity for assessing biological integrity of fish communities in dunal, palustrine wetlands, we assessed the non-point source influence of an industrial landfill on the Grand Calument Lagoons. The landfill is primarily an iron and steel manufacturers' slag waste. No sensitive species, hybrids, headwater species, and either few or no simple lithophilic spawning species were collected from any of the sites in the Grand Calumet Lagoons. Species catch-per-unit of effort varied significantly between reaches in the Middle Lagoon and the West Lagoon. The most disturbed areas were adjacent to the industrial landfill and along the southern shore near the outflow from the West Lagoon. Near- and far-field stations processed similar numbers of species and relative abundance. The near-field stations showed an increase in tolerant species, a higher proportion of omnivores and carnivores, and a lower environmental quality rating of 'poor-very poor'. The far-field sites were classified as having 'fair' biological integrity and showed an increase in relative abundance, proportion of sensitive species, and an increase in simple lithophils. The loss of biological integrity in the West Pond was not accurately predicted using the modified index of biological integrity, even though it was rated as extremely degraded by the biological diversity indices. Fish communities were negatively impacted by proximity to the landfill.

  7. Spatial evaluation of alternative nonpoint nutrient regulatory instruments

    NASA Astrophysics Data System (ADS)

    Whittaker, Gerald; FäRe, Rolf; Srinivasan, Raghavan; Scott, David W.

    2003-04-01

    Recent work has shown that because of differences in the physical environment across an area the choice of an instrument for regulation of nonpoint source agricultural pollution is an empirical question. The objective of this study is an empirical comparison of an economic incentive policy (an input tax) for reduction of agricultural fertilizer application with a command and control policy. Although a "first-best" policy would be administered at the farm level, transactions costs practically require a single policy for the whole area. In an application to the Columbia plateau, a 300% input tax is shown to be preferred to a mandated 25% reduction in nitrogen fertilizer on financial and policy efficiency grounds.

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

    USGS Publications Warehouse

    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

  9. Integrating watershed– and farm–scale models to target critical source areas while maintaining farm economic viability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nonpoint source pollution from agriculture and the impacts of mitigating best management practices are commonly evaluated based on hydrologic boundaries using watershed models. However, management practice effectiveness is impacted by which of the feasible practices are actually selected, implemente...

  10. Loads of suspended sediment and nutrients from local nonpoint sources to the tidal Potomac River and Estuary, Maryland and Virginia, 1979-81 water years

    USGS Publications Warehouse

    Hickman, R. Edward

    1987-01-01

    Loads of suspended sediment, phosphorus, nitrogen, biochemical oxygen demand, and dissolved silica discharged to the tidal Potomac River and Estuary during the !979-81 water years from three local nonpoint sources have been calculated. The loads in rain falling directly upon the tidal water surface and from overflows of the combined sewer system of the District of Columbia were determined from available information. Loads of materials in the streamflow from local watersheds draining directly to the tidal Potomac River and Estuary downstream from Chain Bridge in Washington, D.C., were calculated from samples of streamflow leaving five monitored watersheds. Average annual yields of substances leaving three urban watersheds (Rock Creek and the Northwest and Northeast Branches of the Anacostia River) and the rural Saint Clements Creek watershed were calculated either by developing relationships between concentration and streamflow or by using the mean of measured concentrations. Yields calculated for the 1979-81 water years are up to 2.3 times period-of-record yields because of greater than average streamflow and stormflow during this 3-year period. Period-of-record yields of suspended sediment from the three urban watersheds and the Saint Clements Creek watershed do not agree with yields reported by other studies. The yields from the urban watersheds are 17 to 51 percent of yields calculated using sediment-concentration data collected during the 1960-62 water years. Previous studies suggest that this decrease is at least partly due to the imposition of effective sediment controls at construction sites and to the construction of two multipurpose reservoirs. The yield calculated for the rural Saint Clements Creek watershed is at least twice the yields calculated for other rural watersheds, a result that may be due to most of the samples of this stream being taken during the summer of the 1981 water year, a very dry period. Loads discharged from all local tributary

  11. Nonpoint-source pollutant discharges of the three major tributaries to Reelfoot Lake, west Tennessee, October 1987-September 1989

    USGS Publications Warehouse

    Lewis, Michael E.; Garrett, Jerry W.; Hoos, Anne B.

    1992-01-01

    An investigation of the concentration and loads of nitrogen, phosphorus, and suspended sediment in storm runoff to Reelfoot Lake, in western Tennessee, was conducted from October 1987 through September 1989. Concentrations of selected herbicides also were defined. Reelfoot Lake, with a sur$ace area of about 15,500 acres, is the largest natural lake in Tennessee and an important recreation and fisheries resource. Previous studies showed that the lake is hypereutrophic, a condition caused by high concentrations of nutrients in water and sediments discharged from the three principal tributaries (South Reelfoot Creek, North Reelfoot Creek, and Running Slough) to the lake. Pesticides, including herbicides, have been detected in the lake?s bottom sediments. Storm runoff contributed about 87percent of the total water discharge of the three main tributaries to Reelfoot Lake. South Reelfoot Creek contributed about 4.7 tons per acre per year of suspended sediment, while North Reelfoot Creek contributed about 1.9 tons per acre per year. Running Slough contributed only about 0.31 ton per acre per year of suspended sediment. Most of the suspended sediment was transported by storm runoff between October and March. About 80 percent of the annual streamflow of the three tributaries occurs during these months. The North Reelfoot Creek basin contributed 8.2 pounds per acre per year of total nitrogen and 2.4 pounds per acre per year of total phosphorus. South Reelfoot Creek basin contributed about 6.5 and 1.3 pounds per acre per year of total nitrogen and phosphorus, respectively, while Running Slough basin contributions were 3.4 and 0.86 pounds per acre per year, respectively. The differences in nutrient yields appear to result from more row-crop agriculture and the relatively steeply sloping agricultural land in the North Reelfoot Creek basin. Ninety-one percent of the total nitrogen load and 95 percent of the total phosphorus load in the three streams was transported by storm

  12. Impacts of climate and land-use changes on the migration of non-point source nitrogen and phosphorus during rainfall-runoff in the Jialing River Watershed, China

    NASA Astrophysics Data System (ADS)

    Wu, Lei; Long, Tian-yu; Liu, Xia; Guo, Jin-song

    2012-12-01

    SummaryThe loss of nitrogen and phosphorus via non-point source (NPS) pollution in the Jialing River Watershed has become the main pollution sources of river waters in the Three Gorges reservoir area in the past decades, while climatic conditions and human activities directly affect changes of rainfall-runoff and land use types which are closely related to NPS pollution. This study is to assess the impact of climate change on hydrological behavior considering future land-use types and rural residential area and their propagation to NPS pollution loads. An integrated pollution load model composed of regional climate, the Semi-distributed Land Use based Runoff Processes (SLURPs) hydrological model and the improved export coefficient approach within a single framework was explored and developed to assess impacts of climate and land-use changes on NPS pollution load. Climate data for the Special Report on Emissions Scenarios (SRESs) future scenario B2 from Met Office Hadley center were generated and used as the input data for the runoff and NPS load evaluation of the Jialing River Watershed and the Markov process was used to forecast changes of land use types, respectively. Simulations of present and future regional NPS pollution from land use, livestock and poultry breeding, and agricultural population over the Jialing River Watershed were performed to investigate the potential impacts of global climate change on river water quality using the established model. Results demonstrate that: (1) Annual pollution load would obviously change due to variations of runoff and livestock and poultry breeding, the largest growth months in one year for total nitrogen (TN) and total phosphorus (TP) load are both in June, which is in accordance with changes of rainfall amount. (2) The impacts of global climate change on pollution load are relatively greater when compared to the impacts of future livestock and poultry breeding increase or agricultural population reduction; the effects

  13. The impact of agricultural activities on water quality in oxbow lakes in the Mississippi Delta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the Mississippi Delta, agricultural activity is a major source of nonpoint source (NPS) pollutants. Sediment, nutrients and pesticides have been considered as priority NPS pollutants and greatly affect the water quality in this area. The impacts of agricultural activities on water quality in oxbo...

  14. Effects of agricultural conservation practices on oxbow lake watersheds in the Mississippi River alluvial plain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Globally, agricultural lands are considered to major sources of nonpoint source pollutants such as sediment, pesticides and nutrients in the United States. While conservation practices have been tested for their effectiveness in reducing agricultural related pollutants on test plot scales, they typ...

  15. Identification of Nonpoint Sources of Fecal Pollution in Coastal Waters by Using Host-Specific 16S Ribosomal DNA Genetic Markers from Fecal Anaerobes

    PubMed Central

    Bernhard, Anne E.; Field, Katharine G.

    2000-01-01

    We describe a new PCR-based method for distinguishing human and cow fecal contamination in coastal waters without culturing indicator organisms, and we show that the method can be used to track bacterial marker sequences in complex environments. We identified two human-specific genetic markers and five cow-specific genetic markers in fecal samples by amplifying 16S ribosomal DNA (rDNA) fragments from members of the genus Bifidobacterium and the Bacteroides-Prevotella group and performing length heterogeneity PCR and terminal restriction fragment length polymorphism analyses. Host-specific patterns suggested that there are species composition differences in the Bifidobacterium and Bacteroides-Prevotella populations of human and cow feces. The patterns were highly reproducible among different hosts belonging to the same species. Additionally, all host-specific genetic markers were detected in water samples collected from areas frequently contaminated with fecal pollution. Ease of detection and longer survival in water made Bacteroides-Prevotella indicators better than Bifidobacterium indicators. Fecal 16S rDNA sequences corresponding to our Bacteroides-Prevotella markers comprised closely related gene clusters, none of which exactly matched previously published Bacteroides or Prevotella sequences. Our method detected host-specific markers in water at pollutant concentrations of 2.8 × 10−5 to 2.8 × 10−7 g (dry weight) of feces/liter and 6.8 × 10−7 g (dry weight) of sewage/liter. Although our aim was to identify nonpoint sources of fecal contamination, the method described here should be widely applicable for monitoring spatial and temporal fluctuations in specific bacterial groups in natural environments. PMID:10742246

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

    NASA Astrophysics Data System (ADS)

    Grazhdani, Dorina

    2015-07-01

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

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

    PubMed

    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. PMID:26898934

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

    PubMed

    Grazhdani, Dorina

    2015-07-01

    Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods--dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was 6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas. PMID:25860594

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

    USGS Publications Warehouse

    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.

  20. Developing a GIS-Based Model to Track Potential Point and Non-Point Sources of Urban Stream Pollution

    NASA Astrophysics Data System (ADS)

    Day, C. A.

    2014-12-01

    Urban streams are often characterized by diminished water quality resulting from an increase in polluted runoff from impervious surfaces. Storm activity further reduces urban stream water quality by temporarily increasing stormwater discharge from sewer overflows. This will often manifest itself in rapid declines of dissolved oxygen and peaks in specific conductivity in response to a rising biochemical oxygen demand which slowly recovers as the pollution load is washed through the stream system. This research developed a GIS-based model to track potential sources of pollution based on the dissolved oxygen and specific conductivity response of urban streams to a series of storm events, within the city of Louisville, Kentucky. Watershed outlet hydrographs were first obtained to determine the lag time of dissolved oxygen drops and specific conductivity peaks in response to set of storm events. Using a digital elevation model and the National Landcover Database, 10m resolution rasters were then created which calculated slope and flow direction/accumulation for both open channel and overland flow conditions across the watersheds. The rasters were merged and converted to flow velocities using a series of storms with different intensities. The final step utilized the Flow Length tool in ArcGIS which calculated the travel time to the watershed outlets from each pixel weighted by the open channel and overland flow conditions. Potential pollution sources could then be located by matching the dissolved oxygen and specific conductivity response lag times to the associated watershed travel times.

  1. Application of TABU Search Algorithm with a Coupled ANNAGNPS-CCHE1D Model to Optimize Agricultural Land Use

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A principal contributor to soil erosion and nonpoint source pollution, agricultural activities have a major influence on the environmental quality of a watershed. Impact of agricultural activities on the quality of water resources can be minimized by implementing suitable agriculture land-use types....

  2. [Accumulation of non-point source pollutants in ditch wetland and their uptake and purification by plants].

    PubMed

    Jiang, Cuiling; Fan, Xiaoqiu; Zhang, Yibing

    2005-07-01

    The study on the vertical and horizontal distribution of organic matters and total nitrogen (TN) in the sediment of ditch wetland naturally grown with reed (Phragmites communis) and wild rice (Zizania latifolia) showed that the sediment below 40 cm depth had a significant effectiveness in retaining and accumulating organic matters and TN, but in its surface layer, this effectiveness varied largely with seasons, and the maximum was more than twofold of the minimum. TN was highly correlated with organic matters, the correlation coefficient being 0.9876 in reed wetland and 0.9335 in wild rice wetland, and in water phase, it was positively related to NH4+ -N and NO3-N, indicating that the main composition of TN was organic N, and the mineralization of organic N was the sources of inorganic N. The harvest of reed in each autumn could take away 818 kg x hm(-2) of N and 103.6 kg x hm(-2) of P, and that of wild rice could take away 131 kg x hm(-2) of N and 28.9 kg x hm(-2) of P. Zizania caduci flora had a high assimilation ability of nutrients. Its cultivation in ditch wetland to replace wild helophytes would be a good approach to attain higher absorbing ability of N and P, and to resolve the secondary pollution problem of emerged plants, because farmers could harvest it voluntarily. PMID:16252882

  3. EFFECTIVENESS OF RESTORED WETLANDS FOR THE TREATMENT OF AGRICULTURAL RUNOFF

    EPA Science Inventory

    The integration of the tax ditches into a drainage management system provides obvious benefits, but can also present a source of significant nonpoint source pollution from agricultural runoff. Many of Delaware's tax ditches have been listed on Delaware's Clean
    Water Act 303(d)...

  4. Annualized Agricultural Non-Point Source Model Application for Mississippi Delta Beasley Lake Watershed Conservation Practices Assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The principal focus of the USDA Conservation Effect Assessment Project (CEAP) Watershed Assessment Study effort is to provide an assessment of environmental benefits derived from implementing USDA conservation programs. When determining the priority for conservation measures within a watershed for ...

  5. Assessment of Nonpoint Source Chemical Loading Potential to Watersheds Containing Uranium Waste Dumps Associated with Uranium Exploration and Mining, San Rafael Swell, Utah

    USGS Publications Warehouse

    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

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

    USGS Publications Warehouse

    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.

  7. Agricultural Drainage Ditches Mitigate N and P Loads as a Function of Hydrological Variability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural activities play a substantial role in non-point pollution of receiving waters. Several efforts to remediate pollution sources include constructed wetlands, buffer strips and best management practices. However, agricultural drainage ditches are primary intercept wetlands that have not be...

  8. Ammonia emissions from non-agricultural sources in the UK

    NASA Astrophysics Data System (ADS)

    Sutton, M. A.; Dragosits, U.; Tang, Y. S.; Fowler, D.

    A detailed literature review has been undertaken of the magnitude of non-agricultural sources of ammonia (NH 3) in the United Kingdom. Key elements of the work included estimation of nitrogen (N) excreted by different sources (birds, animals, babies, human sweat), review of miscellaneous combustion sources, as well as identification of industrial sources and use of NH 3 as a solvent. Overall the total non-agricultural emission of NH 3 from the UK in 1996 is estimated here as 54 (27-106) kt NH 3-N yr -1, although this includes 11 (6-23) kt yr -1 from agriculture related sources (sewage sludge spreading, biomass burning and agro-industry). Compared with previous estimates for 1990, component source magnitudes have changed both because of revised average emissions per source unit (emission factors) and changes in the source activity between 1990 and 1996. Sources with larger average emission factors than before include horses, wild animals and sea bird colonies, industry, sugar beet processing, household products and non-agricultural fertilizer use, with the last three sources being included for the first time. Sources with smaller emission factors than before include: land spreading of sewage sludge, direct human emissions (sweat, breath, smoking, infants), pets (cats and dogs) and fertilizer manufacture. Between 1990 and 1996 source activities increased for sewage spreading (due to reduced dumping at sea) and transport (due to increased use of catalytic converters), but decreased for coal combustion. Combined with the current UK estimates of agricultural NH 3 emissions of 229 kt N yr -1 (1996), total UK NH 3 emissions are estimated at 283 kt N yr -1. Allowing for an import of reduced nitrogen (NH x) of 30 kt N yr -1 and deposition of 230 kt N yr -1, these figures imply an export of 83 kt NH 3-N yr -1. Although export is larger than previously estimated, due to the larger contribution of non-agricultural NH 3 emissions, it is still insufficient to balance the UK

  9. Distinguishing the Effects of Local Point Sources from Those Caused by Upstream Nonpoint Source (NPS) Inputs: Refinement of a Watershed Development Index for New England

    EPA Science Inventory

    Using EMAP data from the NE Wadeable Stream Survey and state datasets (CT, ME), assessment tools were developed to predict diffuse NPS effects from watershed development and distinguish these from local impacts (point sources, contaminated sediments). Classification schemes were...

  10. RESPONSE OF SKINNER LAKE (INDIANA) TO AGRICULTURAL DRAINAGE

    EPA Science Inventory

    During 1976-1981, various land management practices were initiated on the agricultural watershed of Skinner Lake in Noble County, Indiana. Land treatment practices implemented on the watershed were chosen from the data and experience gained from the nonpoint source pollution stud...

  11. Denitrification of agricultural drainage line water via immobilized denitrification sludge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nonpoint source nitrogen is recognized as a significant water pollutant worldwide. One of the major contributors is agricultural drainage line water. One potential method of reducing this nitrogen discharge to water bodies is the use of immobilized denitrifying sludge (IDS). Our objectives were to 1...

  12. U.S. Department of Agriculture Agricultural Research Service Mahantango Creek Watershed, Pennsylvania, United States: physiography and history

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 420 km**2 Mahantango Creek Watershed, located within the Northern Appalachian Ridges and Valleys, is a subwatershed of the Susquehanna River Basin, which flows to Chesapeake Bay. Research on agricultural management and hydrologic processes that control nutrient loss from nonpoint sources is cond...

  13. Emerging technologies for removing nonpoint phosphorus from surface water and groundwater: introduction.

    PubMed

    Buda, Anthony R; Koopmans, Gerwin F; Bryant, Ray B; Chardon, Wim J

    2012-01-01

    Coastal and freshwater eutrophication continues to accelerate at sites around the world despite intense efforts to control agricultural P loss using traditional conservation and nutrient management strategies. To achieve required reductions in nonpoint P over the next decade, new tools will be needed to address P transfers from soils and applied P sources. Innovative remediation practices are being developed to remove nonpoint P sources from surface water and groundwater using P sorbing materials (PSMs) derived from natural, synthetic, and industrial sources. A wide array of technologies has been conceived, ranging from amendments that immobilize P in soils and manures to filters that remove P from agricultural drainage waters. This collection of papers summarizes theoretical modeling, laboratory, field, and economic assessments of P removal technologies. Modeling and laboratory studies demonstrate the importance of evaluating P removal technologies under controlled conditions before field deployment, and field studies highlight several challenges to P removal that may be unanticipated in the laboratory, including limited P retention by filters during storms, as well as clogging of filters due to sedimentation. Despite the potential of P removal technologies to improve water quality, gaps in our knowledge remain, and additional studies are needed to characterize the long-term performance of these technologies, as well as to more fully understand their costs and benefits in the context of whole-farm- and watershed-scale P management. PMID:22565243

  14. Distinguishing Betwen Effects of Local Inputs (Contaminated Sediments, Point Sources) and Upstream Diffuse Nonpoint Source Input: Refinement of a Watershed Development Index for New England

    EPA Science Inventory

    Assessment tools are being developed to predict diffuse NPS effects from watershed development and distinguish these from local impacts (point sources, contaminated sediments). Using EMAP data from the New England Wadeable Stream Survey and two state datasets (CT, ME), we are de...

  15. The Influence of Perceptions of Practice Characteristics: An Examination of Agricultural Best Management Practice Adoption in Two Indiana Watersheds

    ERIC Educational Resources Information Center

    Reimer, Adam P.; Weinkauf, Denise Klotthor; Prokopy, Linda Stalker

    2012-01-01

    Agricultural best management practices (BMPs), or conservation practices, can help reduce nonpoint source pollution from agricultural lands, as well as provide valuable wildlife habitat. There is a large literature exploring factors that lead to a producer's voluntary adoption of BMPs, but there have been inconsistent findings. Generally, this…

  16. VEGETATION AND ALGAL COMMUNITY COMPOSITION AND DEVELOPMENT OF THREE CONSTRUCTED WETLANDS RECEIVING AGRICULTURAL RUNOFF AND SUBSURFACE DRAINAGE, 1998 TO 2001

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wetland Reservoir Subirrigation Systems (WRSIS) aim to reduce non-point source pollution from agricultural fields while maintaining crop yield and creating wetland wildlife habitat. The WRSIS system directs drainage water from agricultural fields to flow into a passively revegetated constructed wetl...

  17. Association of Fecal Indicator Bacteria with Human Viruses and Microbial Source Tracking Markers at Coastal Beaches Impacted by Nonpoint Source Pollution

    PubMed Central

    McQuaig, Shannon; Griffith, John

    2012-01-01

    Water quality was assessed at two marine beaches in California by measuring the concentrations of culturable fecal indicator bacteria (FIB) and by library-independent microbial source tracking (MST) methods targeting markers of human-associated microbes (human polyomavirus [HPyV] PCR and quantitative PCR, Methanobrevibacter smithii PCR, and Bacteroides sp. strain HF183 PCR) and a human pathogen (adenovirus by nested PCR). FIB levels periodically exceeded regulatory thresholds at Doheny and Avalon Beaches for enterococci (28.5% and 31.7% of samples, respectively) and fecal coliforms (20% and 5.8%, respectively). Adenoviruses were detected at four of five sites at Doheny Beach and were correlated with detection of HPyVs and human Bacteroides HF183; however, adenoviruses were not detected at Avalon Beach. The most frequently detected human source marker at both beaches was Bacteroides HF183, which was detected in 27% of samples. Correlations between FIBs and human markers were much more frequent at Doheny Beach than at Avalon Beach; e.g., adenovirus was correlated with HPyVs and HF183. Human sewage markers and adenoviruses were routinely detected in samples meeting FIB regulatory standards. The toolbox approach of FIB measurement coupled with analysis of several MST markers targeting human pathogens used here demonstrated that human sewage is at least partly responsible for the degradation of water quality, particularly at Doheny Beach, and resulted in a more definitive assessment of recreational water quality and human health risk than reliance on FIB concentrations alone could have provided. PMID:22773625

  18. Using Microbial Source Tracking to Enhance Environmental Stewardship of Agriculture

    NASA Astrophysics Data System (ADS)

    Martin, Sherry; Rose, Joan; Flood, Matthew; Aw, Tiong; Hyndman, David

    2016-04-01

    Large scale agriculture relies on the application of chemical fertilizers and animal manure. It is well known that nutrients in excess of a plant's uptake and soil retention capacity can travel to nearby waterways via surface run-off and groundwater pathways, indirectly fertilizing these aquatic ecosystems. It has not yet been possible to distinguish water quality impacts of fertilizer from those derived from human and animal waste sources. However, new microbial source tracking (MST) tools allow specific identification of fecal pollution. Our objective was to examine pollution risks at the regional scale using MST, mapping and classification and regression tree analysis. We present results Bovine M2 genetic marker data from three flow regimes (baseflow, snow melt, and post-planting rain). Key landscape characteristics were related to the presence of the bovine markers and appear to be related to fate and transport. Impacts at this regional watershed scale will be discussed. Our research aims to identify the impacts of agricultural management practices on water quality by linking nutrient concentrations with fecal pollution sources. We hope that our research will provide guidance that will help improve water quality through agricultural best management practices to reduce pathogen contamination.

  19. Inferring non-point pollution from land cover analysis

    NASA Astrophysics Data System (ADS)

    Hyde, Richard F.

    Best Management Practices (BMP's) in farming were found to significantly reduce agricultural non-point water pollution in Central Indiana. Through the implementation of systems of conservation tillage practices and structural measures at the farm level, reductions in runoff were achieved, thereby minimizing erosion and subsequent sedimentation and pollution of the surface water system. These conclusions resulted from a three and one-half year study entitled, ``The Indiana Heartland Model Implementation Project'' administered by the Indiana Heartland Coordinating Commission, involving cooperation and coordination of farmers, citizens, and a multi-agency, multi-disciplinary team comprised of four universities and numerous governmental agencies. The U.S. Environmental Protection Agency funded research, while the U.S. Department of Agriculture provided cost share monies for BMP implementation. A comprehensive geographically encoded computer-aided data base was constructed which included information on land cover, elevation, slope, aspect, soils, etc. Land cover map files were compiled through remote sensing including Landsat MSS digital data and low altitude color infrared aerial photography sources. This digital data base was suited for spatial and statistical analyses and transferred easily as input to Purdue University's ANSWERS Model for further watershed assessment. The ANSWERS Model is a distributed deterministic model which simulates the monitored reaction of subwatersheds to actual storm events. Through this model inferences were made as to the expected water quality improvements, given BMP's were implemented at critical areas for erosion throughout both watersheds.

  20. Evaluating analytic and risk assessment tools to estimate sediment and nutrients losses from agricultural lands in the southern region of the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-point source pollution from agricultural fields is a critical problem associated with water quality impairment in the USA and a low-oxygen environment in the Gulf of Mexico. The use, development and enhancement of qualitative and quantitative models or tools for assessing agricultural runoff qua...

  1. Including non-point sfources in a water quality trading permit program.

    PubMed

    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. PMID:15850173

  2. Tracing crop-specific sediment sources in agricultural catchments

    NASA Astrophysics Data System (ADS)

    Blake, William H.; Ficken, Katherine J.; Taylor, Philip; Russell, Mark A.; Walling, Desmond E.

    2012-02-01

    A Compound Specific Stable Isotope (CSSI) sediment tracing approach is evaluated for the first time in an agricultural catchment setting against established geochemical fingerprinting techniques. The work demonstrates that novel CSSI techniques have the potential to provide important support for soil resource management policies and inform sediment risk assessment for the protection of aquatic habitats and water resources. Analysis of soil material from a range of crop covers in a mixed land-use agricultural catchment shows that the carbon CSSI signatures of particle-reactive fatty acids label surface agricultural soil with distinct crop-specific signatures, thus permitting sediment eroded from each land-cover to be tracked downstream. High resolution sediment sampling during a storm event and analysis for CSSI and conventional geochemical fingerprints elucidated temporal patterns of sediment mobilisation under different crop regimes and the specific contribution that each crop type makes to downstream sediment load. Pasture sources (65% of the catchment area) dominated the sediment load but areal yield (0.13 ± 0.02 t ha - 1 ) was considerably less than that for winter wheat (0.44 ± 0.15 t ha - 1 ). While temporal patterns in crop response matched runoff and erosion response predictions based on plot-scale rainfall simulation experiments, comparison of biomarker and geochemical fingerprinting data indicated that the latter overestimated cultivated land inputs to catchment sediment yield due to inability to discriminate temporary pasture (in rotation) from cultivated land. This discrepancy, however, presents an opportunity since combination of the two datasets revealed the extremely localised nature of erosion from permanent pasture fields in this system (estimated at up to 0.5 t ha - 1 ). The novel use of CSSI and geochemical tracers in tandem provided unique insights into sediment source dynamics that could not have been derived from each method alone. Research

  3. Seasonal Patterns of Nitrogen and Phosphorus Losses in Agricultural Drainage Ditches in Northern Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drainage ditches convey nutrient laden waters from agricultural landscapes to receiving waters. Surface drainage ditches are landscape features that have been overlooked for non-point source pollution mitigation of receiving waters. The objective of this study was to determine the nitrogen and phosp...

  4. Innovative best management practices for improving nutrient reductions in agricultural landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the burgeoning human population increases pressures on agriculture for increasing yields, the concomitant strain on the aquatic environment downstream is elevated through non-point source pollution. Traditional management practices of conservation tillage, terracing, and cover crops are good prac...

  5. MANAGEMENT OF DIFFUSE POLLUTION IN AGRICULTURAL WATERSHEDS: LESSONS FROM THE MINNESOTA RIVER BASIN. (R825290)

    EPA Science Inventory

    Abstract

    The Minnesota River (Minnesota, USA) receives large non-point source pollutant loads. Complex interactions between agricultural, state agency, environmental groups, and issues of scale make watershed management difficult. Subdividing the basin's 12 major water...

  6. On-site denitrification beds could reduce indirect greenhouse gas emissions from agricultural drainage waters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrate (NO3-) laden agricultural drainage waters are non-point sources of indirect nitrous oxide (N2O) emissions, which represent a significant fraction of total N2O emissions in the USA. On-site denitrification beds filled with woodchips were used to reduce NO3- under carbon rich anaerobic conditi...

  7. Simulated long-term nitrogen losses for a midwestern agricultural watershed in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adequate knowledge on the movement of nutrients under various agricultural practices is essential for developing remedial measures to reduce nonpoint source pollution. Mathematical models, after extensive calibration and validation, are useful to derive such knowledge and to identify site-specific a...

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

    PubMed

    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. PMID:24289005

  9. Airborne reduced nitrogen: ammonia emissions from agriculture and other sources.

    PubMed

    Anderson, Natalie; Strader, Ross; Davidson, Cliff

    2003-06-01

    Ammonia is a basic gas and one of the most abundant nitrogen-containing compounds in the atmosphere. When emitted, ammonia reacts with oxides of nitrogen and sulfur to form particles, typically in the fine particle size range. Roughly half of the PM(2.5) mass in eastern United States is ammonium sulfate, according to the US EPA. Results from recent studies of PM(2.5) show that these fine particles are typically deposited deep in the lungs and may lead to increased morbidity and/or mortality. Also, these particles are in the size range that will degrade visibility. Ammonia emission inventories are usually constructed by multiplying an activity level by an experimentally determined emission factor for each source category. Typical sources of ammonia include livestock, fertilizer, soils, forest fires and slash burning, industry, vehicles, the oceans, humans, pets, wild animals, and waste disposal and recycling activities. Livestock is the largest source category in the United States, with waste from livestock responsible for about 3x10(9) kg of ammonia in 1995. Volatilization of ammonia from livestock waste is dependent on many parameters, and thus emission factors are difficult to predict. Despite a seasonal variation in these values, the emission factors for general livestock categories are usually annually averaged in current inventories. Activity levels for livestock are from the USDA Census of Agriculture, which does not give information about animal raising practices such as housing types and grazing times, waste handling systems, and approximate animal slurry spreading times or methods. Ammonia emissions in the United States in 1995 from sources other than livestock are much lower; for example, annual emissions are roughly 8x10(8) kg from fertilizer, 7x10(7) kg from industry, 5x10(7) kg from vehicles and 1x10(8) kg from humans. There is considerable uncertainty in the emissions from soil and vegetation, although this category may also be significant

  10. Sole-Source Lighting for Controlled-Environment Agriculture

    NASA Technical Reports Server (NTRS)

    Mitchell.Cary; Stutte, Gary W.

    2015-01-01

    Since plants on Earth evolved under broad-spectrum solar radiation, anytime they are grown exclusively under electric lighting that does not contain all wavelengths in similar proportion to those in sunlight, plant appearance and size could be uniquely different. Nevertheless, plants have been grown for decades under fluorescent (FL) (1) + incandescent (IN) (2) lamps as a sole source of lighting (SSL), and researchers have become comfortable that, in certain proportions of FL + IN for a given species, plants can appear "normal" relative to their growth outdoors. The problem with using such traditional SSLs for commercial production typically is short lamp lifespans and not obtaining enough photosynthetically active radiation (PAR, 400-700 nm) when desired. These limitations led to supplementation of FL + IN lamp outputs with longer-lived, high-intensity discharge (HID) lamps in growth chambers (3). As researchers became comfortable that mixes of orange-biased high-pressure sodium (HPS) and blue-biased metal halide (MH) HIDs together also could give normal plant growth at higher intensities, growth chambers and phytotrons subsequently were equipped mainly with HID lamps, with their intense thermal output filtered out by ventilated light caps or thermal-controlled water barriers. For the most part, IN and HID lamps have found a home in commercial protected horticulture, usually for night-break photoperiod lighting (IN) or for seasonal supplemental lighting (mostly HPS) in greenhouses. However, lack of economically viable options for SSL have held back aspects of year-round indoor agriculture from taking off commercially.

  11. Evaluating the risk of non-point source pollution from biosolids: integrated modelling of nutrient losses at field and catchment scales

    NASA Astrophysics Data System (ADS)

    Whitehead, P. G.; Heathwaite, A. L.; Flynn, N. J.; Wade, A. J.; Quinn, P. F.

    2007-01-01

    A semi-distributed model, INCA, has been developed to determine the fate and distribution of nutrients in terrestrial and aquatic systems. The model simulates nitrogen and phosphorus processes in soils, groundwaters and river systems and can be applied in a semi-distributed manner at a range of scales. In this study, the model has been applied at field to sub-catchment to whole catchment scale to evaluate the behaviour of biosolid-derived losses of P in agricultural systems. It is shown that process-based models such as INCA, applied at a wide range of scales, reproduce field and catchment behaviour satisfactorily. The INCA model can also be used to generate generic information for risk assessment. By adjusting three key variables: biosolid application rates, the hydrological connectivity of the catchment and the initial P-status of the soils within the model, a matrix of P loss rates can be generated to evaluate the behaviour of the model and, hence, of the catchment system. The results, which indicate the sensitivity of the catchment to flow paths, to application rates and to initial soil conditions, have been incorporated into a Nutrient Export Risk Matrix (NERM).

  12. Development and application of a coupled bio-geochmical and hydrological model for point and non-point source river water pollution

    NASA Astrophysics Data System (ADS)

    Pohlert, T.

    2007-12-01

    The aim of this paper is to present recent developments of an integrated water- and N-balance model for the assessment of land use changes on water and N-fluxes for meso-scale river catchments. The semi-distributed water-balance model SWAT was coupled with algorithms of the bio-geochemical model DNDC as well as the model CropSyst. The new model that is further denoted as SWAT-N was tested with leaching data from a long- term lysimeter experiment as well as results from a 5-years sampling campaign that was conducted at the outlet of the meso-scale catchment of the River Dill (Germany). The model efficiency for N-load as well as the spatial representation of N-load along the river channel that was tested with results taken from longitudinal profiles show that the accuracy of the model has improved due to the integration of the aforementioned process-oriented models. After model development and model testing, SWAT-N was then used for the assessment of the EU agricultural policy (CAP reform) on land use change and consequent changes on N-fluxes within the Dill Catchment. giessen.de/geb/volltexte/2007/4531/

  13. Potential alternative fuel sources for agricultural crops and plant components

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The changing landscape of agricultural production is placing unprecedented demands on farmers as they face increasing global competition and greater natural resource conservation challenges. However, shrinking profit margins due to increasing input costs, particularly of fuel and fertilizer, can res...

  14. Diffractive micro-optical element with nonpoint response

    NASA Astrophysics Data System (ADS)

    Soifer, Victor A.; Golub, Michael A.

    1993-01-01

    Common-use diffractive lenses have microrelief zones in the form of simple rings that provide only an optical power but do not contain any image information. They have a point-image response under point-source illumination. We must use a more complicated non-point response to focus a light beam into different light marks, letter-type images as well as for optical pattern recognition. The current presentation describes computer generation of diffractive micro- optical elements with complicated curvilinear zones of a regular piecewise-smooth structure and grey-level or staircase phase microrelief. The manufacture of non-point response elements uses the steps of phase-transfer calculation and orthogonal-scan masks generation or lithographic glass etching. Ray-tracing method is shown to be applicable in this task. Several working samples of focusing optical elements generated by computer and photolithography are presented. Using the experimental results we discuss here such applications as laser branding.

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

    PubMed

    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. PMID:26259471

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

    PubMed

    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. PMID:26613353

  17. Food and agricultural waste: Sources of carbon for ethanol production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the past, wastes derived from agriculture products have met with limited success in the production of biofuels. Our objective in this report is to showcase a new and meaningful concept (called “avoidance”), to measure the environmental importance of converting these waste streams into energy. Agr...

  18. BIOMASS GASIFICATION FOR AGRICULTURAL ENERGY SOURCES AND SOIL ENRICHMENT

    EPA Science Inventory

    Phase I of the Biomass Gasification Project gave birth to many success stories and demonstrated enormous potential for members of the local agricultural community and for students within the university.

    Community-building

    Watauga County Cooperative Ext...

  19. Agriculture as a source of Aeolian sediment affecting air quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aeolian processes on agricultural lands have been examined for the past several decades on nearly every continent and has led to a better understanding of detachment, entrainment, transport, and deposition. Relatively little is known concerning the effect of these processes on air quality. In fact, ...

  20. The impact of the U.S. biofuels expansion on non-point source pollution from nitrogen in a marginal agricultural area

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Energy Independence Security Act aims to increase the production of renewable fuels in order to improve the energy efficiency of the United States. The goal of this legislation is to produce 36 billion gallons of biofuel, primarily corn ethanol, by 2022. A bioeconomic model is employed, includin...

  1. 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

    USGS Publications Warehouse

    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, moni-toring of bacteria, and the creation of a database to store all relevant data collected from past and future field-data-collec-tion 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 assess-ment 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-sus-pended-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

  2. 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

    USGS Publications Warehouse

    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

  3. Agricultural Science Teachers' Barriers, Roles, and Information Source Preferences for Teaching Biotechnology Topics

    ERIC Educational Resources Information Center

    Mowen, Diana L.; Wingenbach, Gary J.; Roberts, T. Grady; Harlin, Julie F.

    2007-01-01

    The purpose of this study was to determine barriers, roles, and information source preferences for teaching agricultural biotechnology topics. Agricultural science teachers were described primarily as 37 year-old males who had taught for 12 years, had bachelor's degrees, and had lived or worked on a farm or ranch. Equipment was perceived as the…

  4. Emissions from Combustion of Open Area Sources: Prescribed Forest and Agricultural Burns

    EPA Science Inventory

    Emissions from wildfires and prescribed forest and agricultural burns generate a variety of emissions that can cause adverse health effects for humans, contribute to climate change, and decrease visibility. Only limited pollutant data are available for these sources, particularly...

  5. Agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agriculture within the United States is varied and produces a large value ($200 billion in 2002) of production across a wide range of plant and animal production systems. Because of this diversity, changes in climate will likely impact agriculture throughout the United States. Climate affects crop, ...

  6. Research Orientations and Sources of Influence: Agricultural Scientists in the U.S. Land-Grant System.

    ERIC Educational Resources Information Center

    Goldberger, Jessica R.

    2001-01-01

    Uses data from a 1995-96 national survey of agricultural scientists at land-grant universities to investigate the relative importance of 19 sources of influence on agricultural scientists engaged in six areas of agricultural research: productionist-oriented, sustainable agriculture, environmental, basic, consumer-oriented, and rural…

  7. Effects of land-use changes and stormflow-detention basins on flooding and nonpoint-source pollution, in Irondequoit Creek basin, Monroe and Ontario counties, New York--application of a precipitation-runoff model

    USGS Publications Warehouse

    Coon, William F.; Johnson, Mark S.

    2005-01-01

    Urbanization of the 150-square-mile Irondequoit Creek basin in Monroe and Ontario Counties, N.Y., continues to spread southward and eastward from the City of Rochester, on the shore of Lake Ontario. Conversion of forested land to other uses over the past 40 years has increased to the extent that more than 50 percent of the basin is now developed. This expansion has increased flooding and impaired stream-water quality in the northern (downstream) half of the basin. A precipitation-runoff model of the Irondequoit Creek basin was developed with the model code HSPF (Hydrological Simulation Program--FORTRAN) to simulate the effects of land-use changes and stormflow-detention basins on flooding and nonpoint-source pollution on the basin. Model performance was evaluated through a combination of graphical comparisons and statistical tests, and indicated 'very good' agreement (mean error less than 10 percent) between observed and simulated daily and monthly streamflows, between observed and simulated monthly water temperatures, and between observed total suspended solids loads and simulated sediment loads. Agreement between monthly observed and simulated nutrient loads was 'very good' (mean error less than 15 percent) or 'good' (mean error between 15 and 25 percent). Results of model simulations indicated that peak flows and loads of sediment and total phosphorus would increase in a rural subbasin, where 10 percent of the basin was converted from forest and grassland to pervious and impervious developed areas. Subsequent simulation of a stormflow-detention basin at the mouth of this subbasin indicated that peak flows and constituent loads would decrease below those that were generated by the land-use-change scenario, and, in some cases, below those that were simulated by the original land-use scenario. Other results from model simulations of peak flows over a 30-year period (1970-2000), with and without simulation of 50-percent flow reductions at one existing and nine

  8. Critical source times for nutrient loss in agricultural catchment streams

    NASA Astrophysics Data System (ADS)

    Melland, Alice; Shore, Mairead; Mellander, Per-Erik; McDonald, Noeleen; Shortle, Ger; Murphy, Paul; Jordan, Phil

    2014-05-01

    Identifying periods of the year when there is a high risk of incidental nutrient loss from farms via runoff to streams underpins current nutrient management legislation in Europe. This research explored high-temporal resolution nutrient transfer patterns relative to the time that manure and fertiliser are prohibited from being spread (the mandatory spreading 'closed' period) in five Irish agricultural catchments. Catchment nutrient losses during the 12 week closed periods in 2009-10, 2010-11 and 2011-12 were compared with losses during the remainder of the year, and with losses in the two week 'shoulder' periods immediately before and after the closed period. The closed period losses were assumed to be residual from soil nutrient stores and the 'shoulder' periods were considered to also include incidental losses. Nutrient loss was measured at sub-hourly frequency as total phosphorus (P) and total oxidised nitrogen (mostly nitrate-N) fluxes in streamflow. The streamflow fluxes showed that the proportion of the annual nitrate-N loss occurring during the closed periods (33-61%) was high compared with the remainder of the year. Six to ten times more nitrate-N loss occurred in the two weeks after, compared with the two weeks before, the closed period. These two week 'shoulder' period losses were, on average, less than or equal to 2.5 kg nitrate-N/ha and 9% of total annual nitrate-N loss in streamflow. On average, 40-53% of the annual P loss occurred during the closed periods but in a runoff-prone catchment in a year with a wet summer, the closed period was the less risky period. Similar to nitrate-N, two to twenty times more P loss occurred in the two weeks after, compared with the two weeks before, the closed period. These shoulder period losses were, on average, less than or equal to 0.027 kg/ha and 4.2% of total annual P loss in streamflow. The proportion of the shoulder period loss that could be attributed to recently spread nutrients was not known but can be

  9. Horse paddocks - an emerging source of agricultural water pollution

    NASA Astrophysics Data System (ADS)

    Masud Parvage, Mohammed; Ulén, Barbro; Kirchmann, Holger

    2015-04-01

    Horse farms occupy about 4% of the total agricultural land in the EU but are not well investigated with regard to their impact on water quality. Horse paddocks commonly hold horses on a limited space and the animal density often exceeds the recommended density. Therefore, paddock soils receive significant amounts of phosphorus (P) and nitrogen (N) through feed residues and deposition of faeces and urine, which can lead to nutrient build-up in the soil and subsequent losses to aquatic systems. This study characterized the potential risk of phosphorus (P) and nitrogen (N) leaching losses from Swedish horse paddocks through three stage examination of soil and water P and N status. The experiment began with a pilot study where surface soil P status and eight years of drainage P data were examined from a paddock catchment and an adjacent arable catchment both receiving similar amount of P and N over years. Results showed that there were no signi?cant differences in water-soluble P (WSP) or total P data in soils but the drainage water P concentrations, being higher in the paddock catchment (0.33 mg P l-1, mainly in dissolved reactive form) than the arable catchment (0.10 mg P l-1). In the second experiment, soil P and N status were examined in different parts of horse paddocks (feeding, grazing, and excretion areas) to identify existence of any potential hotspots for losses within the paddock. In total, seven horse farms, covering different grazing densities and soil textures representative of Swedish horse paddocks were examined. The results showed that concentrations of WSP, plant available P or P-AL (P extracted in ammonium acetate lactate solution at pH 3.75), and total N were highest in feeding and excretion areas within the paddocks. It was also observed that the WSP concentration in the paddocks was strongly correlated with horse density (R2 = 0.80, p < 0.001) and P-AL with years of paddock management (R2 = 0.78, p < 0.001). In the final experiment, topsoil

  10. Mitigation strategies for methane emissions from agricultural sources

    SciTech Connect

    Duxbury, J.M.

    1993-12-31

    Anthropogenic emissions of CH{sub 4} account for 70% of total global emissions of this greenhouse gas. Current anthropogenic emissions of CH{sub 4} in the US are estimated to be between 24-30 Tg CH{sub 4} or 7-9% of the global anthropogenic total. By comparison the US is responsible for 27% of anthropogenic emissions of CO{sub 2} from fossil fuel use. Table 1 shows that the major anthropogenic sources of CH{sub 4} in the US are landfills (37%), domestic livestock and livestock waste (31%) and the coal mining/natural gas/petroleum industries (28%). On a global basis it is estimated that US landfills contribute 30% to the global landfill total, whereas livestock (including waste) and the coal mining/natural gas/petroleum industries each contribute about 8% to their respective global totals. The US is an insignificant contributor (< 1%) to global emissions of CH{sub 4} from rice paddies.

  11. Potential pollutant sources in a Choptank River subwatershed: Influence of agricultural and residential land use and aqueous and atmospheric sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agriculture and animal feeding operations have been implicated as sources of water pollution along the Choptank River, an estuary and tributary of the Chesapeake Bay. This study examined a subwatershed within the Choptank River watershed for effects of land use on water quality. Water and sediment...

  12. Sediment fingerprinting in agricultural catchments: A critical re-examination of source discrimination and data corrections

    NASA Astrophysics Data System (ADS)

    Smith, Hugh G.; Blake, William H.

    2014-01-01

    Fine sediment source fingerprinting techniques have been widely applied in agricultural river catchments. Successful source discrimination in agricultural environments depends on the key assumption that land-use source signatures imprinted on catchment soils are decipherable from those due to other landscape factors affecting soil and sediment properties. In this study, we re-examine this critical assumption by investigating (i) the physical and chemical basis for source discrimination and (ii) potential factors that may confound source un-mixing in agricultural catchments, including particle size and organic matter effects on tracer properties. The study is situated in the River Tamar, a predominantly agricultural catchment (920 km2) in south-west England that has also been affected by mining. Source discrimination focused on pasture and cultivated land uses and channel banks. Monthly, time-integrated suspended sediment samples were collected across seven catchments for a 12-month period. Physical and chemical properties measured in source soils and sediment included fallout radionuclides (137Cs, excess 210Pb), major and minor element geochemical constituents, total organic carbon and particle size. Source discrimination was entirely dependent on differences in tracer property concentrations between surface and sub-surface soils. This is based on fallout radionuclide concentrations that are surface-elevated, while many geochemical properties are surface-depleted due to weathering and pedogenetic effects, although surface soil contamination can reverse this trend. However, source discrimination in the study catchments was limited by (i) rotation of cultivated and pasture fields resulting in reduced differences between these two sources, and (ii) the cultivated source signature resembling a mix of the pasture and channel bank sources for many tracer properties. Furthermore, a combination of metal pollution from abandoned historic mines and organic enrichment of

  13. Sources of fine sediment stored in agricultural lowland streams, Midwest, USA

    NASA Astrophysics Data System (ADS)

    Lamba, Jasmeet; Thompson, A. M.; Karthikeyan, K. G.; Fitzpatrick, Faith A.

    2015-05-01

    Agricultural activities can accelerate the offsite transport of productive soil from fields leading to stream water quality degradation. Identification of the nature and relative contribution of different sources to fine-grained sediment (e.g., silts, clays) in streams is important to effectively focus agricultural best management practices in watersheds. Sediment fingerprinting techniques through the use of geochemical tracers are commonly used to differentiate relative contribution from various sources. Research was conducted in lowland streams in the Pleasant Valley watershed in South Central Wisconsin (USA) to identify provenance of fine-grained sediment deposits and evaluate the impact of land use on relative contributions from the following potential sources: cropland, pasture, woodland, and eroding stream banks. Results show that both agriculture (croplands and pastures) and eroding stream banks are primary sources to fine sediment deposits on the stream bed with contributions ranging from 19 to 100% and 0 to 81%, respectively. The increase in area under agricultural land use within a subwatershed results in greater contribution from agriculture (R2 = 0.846, p = 0.0034). Relative contributions from eroding stream banks increased with increasing area under grasslands and woodlands within a subwatershed (R2 = 0.814, p = 0.0055). Subwatersheds with greater mass of fine sediment deposited on the stream bed per unit area should be prioritized for best management practices. The conservation practices should be targeted to stream banks or croplands depending on the dominant source of fine sediment within a subwatershed. Site specific changes in relative contributions from different sources to fine-grained sediment in this watershed highlights the complexities involved in sediment transport dynamics. The nested sampling sites helped determine that sediment dynamics at the subwatershed scale need to be considered for application of targeted conservation techniques.

  14. A VSA-based strategy for placing conservation buffers in agricultural watersheds.

    PubMed

    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. PMID:14753616

  15. Great lakes eutrophication: the effect of point source control of total phosphorus.

    PubMed

    Chapra, S C; Robertson, A

    1977-06-24

    A mathematical model of the Great Lakes total phosphorus budgets indicates that a 1 milligram per liter effluent restriction for point sources would result in significant improvement in the trophic status of most of the system. However, because large areas of their drainage basins are devoted to agriculture or are urbanized, western Lake Erie, lower Green Bay, and Saginaw Bay may require non-point source controls to effect significant improvements in their trophic status. PMID:17776924

  16. GCAM 3.0 Agriculture and Land Use: Data Sources and Methods

    SciTech Connect

    Kyle, G. Page; Luckow, Patrick; Calvin, Katherine V.; Emanuel, William R.; Nathan, Mayda; Zhou, Yuyu

    2011-12-12

    This report presents the data processing methods used in the GCAM 3.0 agriculture and land use component, starting from all source data used, and detailing all calculations and assumptions made in generating the model inputs. The report starts with a brief introduction to modeling of agriculture and land use in GCAM 3.0, and then provides documentation of the data and methods used for generating the base-year dataset and future scenario parameters assumed in the model input files. Specifically, the report addresses primary commodity production, secondary (animal) commodity production, disposition of commodities, land allocation, land carbon contents, and land values.

  17. Sources of nutrients to windward agricultural systems in pre-contact Hawai'i.

    PubMed

    Palmer, Molly A; Graves, Michael; Ladefoged, Thegn N; Chadwick, Oliver A; Duarte, T Ka'eo; Porder, Stephen; Vitousek, Peter M

    2009-09-01

    Prior to European contact in 1778, Hawaiians developed intensive irrigated pondfield agricultural systems in windward Kohala, Hawai'i. We evaluated three potential sources of nutrients to windward systems that could have sustained intensive agriculture: (1) in situ weathering of primary and secondary minerals in upland soils; (2) rejuvenation of the supply of rock-derived nutrients on eroded slopes and in alluvium; and (3) transport of rock-derived nutrients to crops via irrigation water. Our results show that most windward soils are infertile and suggest that weathering of minerals within upland soils was insufficient to sustain intensive agriculture without substantial cultural inputs. Erosion enhances weathering and so increases nutrient supply, with soils of the largest alluvial valleys (>200 m deep) retaining 37% of calcium from parent material (compared to 2% in upland sites). However, soils of smaller valleys that also supported pre-contact agricultural systems are substantially less enriched. Isotopic 87Sr/86Sr analyses of stream water demonstrate that at low to moderate stream flow over 90% of dissolved strontium derives from weathering of basalt rather than deposition of atmospheric sources; most other dissolved cations also derive from basalt weathering. We calculate that irrigation water could have supplied approximately 200 kg ha(-1) yr(-1) of calcium to pondfield systems, nearly 100 times more than was supplied by weathering in soils on stable geomorphic surfaces. In effect, irrigation waters brought nutrients from rocks to the windward crops. PMID:19769093

  18. Identification of nitrogen sources to four small lakes in the agricultural region of Khorezm, Uzbekistan

    USGS Publications Warehouse

    Shanafield, M.; Rosen, M.; Saito, L.; Chandra, S.; Lamers, J.; Nishonov, Bakhriddin

    2010-01-01

    Pollution of inland waters by agricultural land use is a concern in many areas of the world, and especially in arid regions, where water resources are inherently scarce. This study used physical and chemical water quality and stable nitrogen isotope (δ15N) measurements from zooplankton to examine nitrogen (N) sources and concentrations in four small lakes of Khorezm, Uzbekistan, an arid, highly agricultural region, which is part of the environmentally-impacted Aral Sea Basin. During the 2-year study period, ammonium concentrations were the highest dissolved inorganic N species in all lakes, with a maximum of 3.00 mg N l−1 and an average concentration of 0.62 mg N l−1. Nitrate levels were low, with a maximum concentration of 0.46 mg N l−1 and an average of 0.05 mg N l−1 for all four lakes. The limited zooplankton δ15N values did not correlate with the high loads of synthetic fertilizer applied to local croplands during summer months. These results suggest that the N cycles in these lakes may be more influenced by regional dynamics than agricultural activity in the immediate surroundings. The Amu-Darya River, which provides the main source of irrigation water to the region, was identified as a possible source of the primary N input to the lakes.

  19. U and Sr Isotope Tracers of Agricultural Salinity Sources to the Lower Rio Grande River

    NASA Astrophysics Data System (ADS)

    Nyachoti, S. K.; Ma, L.; Szynkiewicz, A.; Jin, L.; McIntosh, J. C.

    2014-12-01

    Elevated salinity of the lower Rio Grande River deteriorates water quality and limits domestic and agricultural water use. Both natural and anthropogenic processes contribute salts in the Rio Grande. Previous studies have focused on natural salt contributions with less emphasis on anthropogenic sources of salinity in the Rio Grande. Using (234U/238U) activity ratios (UAR), 87Sr/86Sr isotope ratios, and major element concentrations, we aim to trace and quantify the salt loads in the Lower Rio Grande watershed which is greatly impacted by agricultural activities. Between 2009 and 2010, we sampled the Rio Grande stretch and irrigation return flows between the Elephant Butte Reservoir, New Mexico and El Paso, Texas. Furthermore, we monitored in monthly intervals the temporal changes of chemical and isotopic compositions of the Rio Grande at Canutillo, Tx. Our results show higher U and Sr fluxes in the Rio Grande during the irrigation season as compared to the non-irrigation season. The UAR (1.62 to 2.13) and 87Sr/86Sr ratios (0.7099 to 0.7138) were higher in the non-irrigation season compared to the irrigation season (UAR: 1.69 to 1.77; 87Sr/86Sr: 0.7100 to 0.7106). These variations of UAR and 87Sr/86Sr ratios imply multiple sources of U and Sr in the Rio Grande. In contrast, the agricultural return flows show a narrow range of UAR (1.31 to 1.37) and 87Sr/86Sr ratios (0.7091 to 0.7099) in the studied seasons. This is consistent with salinity contributions from agricultural sources. Rio Grande at Canutillo shows low UAR (1.62 to 1.77) and 87Sr/86Sr ratios (0.7104 to 0.7105) during the irrigation season as compared to the non-irrigation season (UAR: 2.04 to 2.24; 87Sr/86Sr: 0.7105 to 0.7109). The low U and Sr signature at Canutillo during the irrigation season is close to that of the agricultural return flows, indicative of agricultural salinity sources. These results provide useful elemental and isotopic constraints for future mass balance calculations of salinity

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

    NASA Astrophysics Data System (ADS)

    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

  1. Managing agricultural phosphorus for water quality: lessons from the USA and China.

    PubMed

    Sharpley, Andrew; Wang, Xiaoyan

    2014-09-01

    The accelerated eutrophication of freshwaters and to a lesser extent some coastal waters is primarily driven by phosphorus (P) inputs. While efforts to identify and limit point source inputs of P to surface waters have seen some success, nonpoint sources remain difficult to identify, target, and remediate. As further improvements in wastewater treatment technologies becomes increasingly costly, attention has focused more on nonpoint source reduction, particularly the role of agriculture. This attention was heightened over the last 10 to 20 years by a number of highly visible cases of nutrient-related water quality degradation; including the Lake Taihu, Baltic Sea, Chesapeake Bay, and Gulf of Mexico. Thus, there has been a shift to targeted management of critical sources of P loss. In both the U.S. and China, there has been an intensification of agricultural production systems in certain areas concentrate large amounts of nutrients in excess of local crop and forage needs, which has increased the potential for P loss from these areas. To address this, innovative technologies are emerging that recycle water P back to land as fertilizer. For example, in the watershed of Lake Taihu, China one of the largest surface fresh waters for drinking water supply in China, local governments have encouraged innovation and various technical trials to harvest harmful algal blooms and use them for bio-gas, agricultural fertilizers, and biofuel production. In any country, however, the economics of remediation will remain a key limitation to substantial changes in agricultural production. PMID:25193824

  2. A watershed modeling framework for phosphorus loading from residential and agricultural sources.

    PubMed

    Sinclair, Andrew; Jamieson, Rob; Madani, Ali; Gordon, Robert J; Hart, William; Hebb, Dale

    2014-07-01

    Phosphorus (P) loading from residential onsite wastewater systems (OWSs) into neighboring surface waters is a poorly understood process in rural watersheds; this can be further challenged when rural residential dwellings are intermixed with agricultural land use. The objectives of this research were (i) to design a P onsite wastewater simulator (POWSIM) to assess P loads from individual or clusters of residential OWSs typically used in Nova Scotia, Canada; and (ii) to simulate OWS P loads in a mixed agricultural watershed (Thomas Brook Watershed [TBW], NS) using the Soil and Water Assessment Tool (SWAT) model in conjunction with POWSIM, to predict and compare P loading from agricultural and residential sources. The POWSIM loading tool has three computational components: (i) disposal field selection and treatment media mass calculation, (ii) disposal field P treatment dynamics, and (iii) soil subsurface plume P treatment dynamics. The combination TBW POWSIM and SWAT modeling approach produced a better simulation of baseflow total P (TP) loads in both a predominantly residential subcatchment and one dominated by agriculture than the SWAT model without POWSIM. The residential subcatchment had 48% of its average annual land use TP load (simulated) contributed by OWSs, whereas the agricultural subcatchment had 39%. Watershed-scale sensitivity analyses of POWSIM input parameters for 18- and 50-yr OWS operation periods found the P loading rate into the disposal field, long-term P removal rates in the disposal field and soil systems, soil maximum P sorption capacity, and mass of native soil involved in P treatment to be most sensitive. PMID:25603083

  3. Stream Sediment Sources in Midwest Agricultural Basins with Land Retirement along Channel.

    PubMed

    Williamson, T N; Christensen, V G; Richardson, W B; Frey, J W; Gellis, A C; Kieta, K A; Fitzpatrick, F A

    2014-09-01

    Documenting the effects of agricultural land retirement on stream-sediment sources is critical to identifying management practices that improve water quality and aquatic habitat. Particularly difficult to quantify are the effects from conservation easements that commonly are discontinuous along channelized streams and ditches throughout the agricultural midwestern United States. Our hypotheses were that sediment from cropland, retired land, stream banks, and roads would be discernible using isotopic and elemental concentrations and that source contributions would vary with land retirement distribution along tributaries of West Fork Beaver Creek in Minnesota. Channel-bed and suspended sediment were sampled at nine locations and compared with local source samples by using linear discriminant analysis and a four-source mixing model that evaluated seven tracers: In, P, total C, Be, Tl, Th, and Ti. The proportion of sediment sources differed significantly between suspended and channel-bed sediment. Retired land contributed to channel-bed sediment but was not discernible as a source of suspended sediment, suggesting that retired-land material was not mobilized during high-flow conditions. Stream banks were a large contributor to suspended sediment; however, the percentage of stream-bank sediment in the channel bed was lower in basins with more continuous retired land along the riparian corridor. Cropland sediments had the highest P concentrations; basins with the highest cropland-sediment contributions also had the highest P concentrations. Along stream reaches with retired land, there was a lower proportion of cropland material in suspended sediment relative to sites that had almost no land retirement, indicating less movement of nutrients and sediment from cropland to the channel as a result of land retirement. PMID:25603248

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

    NASA Astrophysics Data System (ADS)

    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.

  5. COMPARATIVE DIVERSITY OF FECAL BACTERIA IN AGRICULTURALLY SIGNIFICANT ANIMALS TO IDENTIFY ALTERNATIVE TARGETS FOR MICROBIAL SOURCE TRACKING

    EPA Science Inventory

    Animals of agricultural significance contribute a large percentage of fecal pollution to waterways via runoff contamination. The premise of microbial source tracking is to utilize fecal bacteria to identify target populations which are directly correlated to specific animal feces...

  6. Using Strontium Isotopes in Arid Agricultural Soils to Determine a Sink or Source of CO2

    NASA Astrophysics Data System (ADS)

    Ortiz, A. C.; Jin, L.

    2014-12-01

    Arid and semi-arid regions of the world are predicted to continue to expand through land degradation and prolonged drought events. Agricultural practices in these drylands degrade soils through elevated salinity, sodicity and alkalinity. Indeed, flood irrigation loads salts onto the soils including carbonate minerals in the form of calcite. Alfalfa and Pecan are salt tolerant and commonly grown in the arid El Paso region, but need irrigation using Rio Grande water with little to no contribution from local ground waters. We hypothesize that the irrigation is loading extra Ca and bicarbonate to soils and anthropogenically enhancing the precipitation of carbonates. We intend to monitor soil CO2 efflux after irrigation, characterize soil minerals, and combine them to isotopic data of soil, irrigation, and drainage waters to link the sources of Ca and C, kinetics of calcite precipitation, to irrigation events. This will include strontium isotopic analysis to determine the source of calcium in the agricultural fields, U-disequilibrium isotopes to estimate the carbonate ages, and CO2 efflux to monitor atmosphere-soil exchange. Carbon dioxide emissions are expected to change during flood irrigation when soils are saturated. After irrigation events, evaporative effects increase Ca and dissolved inorganic carbon concentration in soil waters leading to precipitation of calcite and thus elevated CO2efflux. Preliminary measurements in the pecan field show a marginally significant difference in CO2 fluxes before and after irrigation (p=0.07, t-test). Carbon dioxide emissions are lower during moist conditions (0.6 g m-2hr-1 CO2) than those in dry conditions (1.0 g m-2hr-1 CO2). Future C isotope data are needed to identify the source of extra CO2, biogenic or calcite-precipitation related. A water leachable extraction of alfalfa soils shows 87Sr/86Sr ratios ranged from 0.7101 to 0.7103, indicating Rio Grande river as a dominant calcium source. Further Sr isotopic analysis of

  7. Wetlands and Agriculture in Africa: Major Sources of N2O?

    NASA Astrophysics Data System (ADS)

    Gettel, G. M.

    2015-12-01

    Papyrus wetlands in East Africa are rapidly being converted to agricultural production in an effort to increase food security. This conversion is often seasonal, with wetlands being used for grazing and crop production of maize, sugarcane, and rice during dry seasons, and flooding occurring during wet seasons. An important question with respect to greenhouse gas production is whether wetland conversion to agriculture increases N2O fluxes. This trend has been shown in temperate regions where increased N2O fluxes are positively related to low soil C:N ratios, especially when soil moisture content remains high. In order to examine whether denitrification contributes to N2O flux, we measured potential denitrification rates (PDR by acetylene block method) in intact papyrus wetlands and agricultural converted wetlands in Kenya, Tanzania, Uganda, and Rwanda, and also performed multivariate analysis to relate soil characteristics to PDR. Agricultural land-cover types included maize, sugarcane, rice, and grazing. Results showed that intact wetlands are potentially important sources of N2O, as PDR in papyrus vegetation were consistently the highest (p<0.05; 128 - 601 μg N2O g DW-1 hour-1) while grazing sites showed the lowest (0.1 - 0.5 μg N2O g DW-1 hour-1). Rates were second highest in rice fields (2.3 - 303 μg N2O g DW-1 hour-1), and intermediate in maize and sugarcane (6.5 - 75 μmg N2O g DW-1 hour-1 and 5 - 30 μg N2O g DW-1 hour-1 respectively). PDR across all sites was inversely related to soil C:N ratio, with nitrate consistently limiting PDR in the wetland sites while soil carbon limited PDR in agricultural sites. This is seemingly in contrast with other findings that show that lower C:N ratios result in high N2O fluxes from drained wetland sites. However, flux measurements along with more realistic process-based measurements of denitrification are urgently needed to more fully understand the effect of agricultural conversion of wetlands in East Africa.

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

    PubMed

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

    2016-01-01

    Chloride is a relatively unreactive plant nutrient that has long been used as a biogeochemical tracer but also can be a pollutant causing aquatic biology impacts when concentrations are high, typically from rock salt applications used for deicing roads. Chloride inputs to watersheds are most often from atmospheric deposition, road salt, or agricultural fertilizer, although studies on agricultural watersheds with large fertilizer inputs are few. We used long-term (21 and 17 yr) chloride water quality data in two rivers of east-central Illinois to better understand chloride biogeochemistry in two agricultural watersheds (Embarras and Kaskaskia), the former with a larger urban land use and both with extensive tile drainage. During our sampling period, the average chloride concentration was 23.7 and 20.9 mg L in the Embarras and Kaskaskia Rivers, respectively. Annual fluxes of chloride were 72.5 and 61.2 kg ha yr in the Embarras and Kaskaskia watersheds, respectively. In both watersheds, fertilizer chloride was the dominant input (∼49 kg ha yr), with road salt likely the other major source (23.2 and 7.2 kg ha yr for the Embarras and Kaskaskia watersheds, respectively). Combining our monitoring data with earlier published data on the Embarras River showed an increase in chloride concentrations as potash use increased in Illinois during the 1960s and 1970s with a lag of about 2 to 6 yr to changes in potash inputs based on a multiple-regression model. In these agricultural watersheds, riverine chloride responds relatively quickly to potash fertilization as a result of tile-drainage. PMID:26828190

  9. An investigation of element ratios for assessing suspended-sediment sources in small agricultural basins

    USGS Publications Warehouse

    Juracek, K.

    2012-01-01

    Various sediment properties previously have been investigated for the purpose of determining sources of suspended sediment. A remaining research need is an assessment of element ratios for the determination of suspended-sediment sources in different terrestrial environments. In this study, 253 element ratios were assessed to determine which, if any, were potentially useful for sediment-source determinations in six small agricultural basins in northeastern Kansas, USA. Samples of surface soils (cropland and grassland), channel banks, and reservoir bottom sediments were collected, analyzed for 23 elements, and compared. Of the 253 element ratios assessed, only the Co/Pb and Co/Zn ratios were substantially and consistently different between the channel banks and surface soils for all six basins. For three of four reservoirs for which data were available, sediment-source estimates provided by Co/Pb ratios were in agreement with estimates previously provided using 137Cs. For two of the four reservoirs, sediment-source estimates provided by Co/Zn ratios were consistent with the 137Cs estimates. Thus, the Co/Pb ratio potentially may be more useful. Additional research is needed to ascertain whether or not the use of Co/Pb and Co/Zn ratios as tracers is widely applicable or restricted to specific terrestrial environments.

  10. Identifying diffused nitrate sources in a stream in an agricultural field using a dual isotopic approach.

    PubMed

    Ding, Jingtao; Xi, Beidou; Gao, Rutai; He, Liansheng; Liu, Hongliang; Dai, Xuanli; Yu, Yijun

    2014-06-15

    Nitrate (NO3(-)) pollution is a severe problem in aquatic systems in Taihu Lake Basin in China. A dual isotope approach (δ(15)NNO3(-) and δ(18)ONO3(-)) was applied to identify diffused NO3(-) inputs in a stream in an agricultural field at the basin in 2013. The site-specific isotopic characteristics of five NO3(-) sources (atmospheric deposition, AD; NO3(-) derived from soil organic matter nitrification, NS; NO3(-) derived from chemical fertilizer nitrification, NF; groundwater, GW; and manure and sewage, M&S) were identified. NO3(-) concentrations in the stream during the rainy season [mean±standard deviation (SD)=2.5±0.4mg/L] were lower than those during the dry season (mean±SD=4.0±0.5mg/L), whereas the δ(18)ONO3(-) values during the rainy season (mean±SD=+12.3±3.6‰) were higher than those during the dry season (mean±SD=+0.9±1.9‰). Both chemical and isotopic characteristics indicated that mixing with atmospheric NO3(-) resulted in the high δ(18)O values during the rainy season, whereas NS and M&S were the dominant NO3(-) sources during the dry season. A Bayesian model was used to determine the contribution of each NO3(-) source to total stream NO3(-). Results showed that reduced N nitrification in soil zones (including soil organic matter and fertilizer) was the main NO3(-) source throughout the year. M&S contributed more NO3(-) during the dry season (22.4%) than during the rainy season (17.8%). AD generated substantial amounts of NO3(-) in May (18.4%), June (29.8%), and July (24.5%). With the assessment of temporal variation of diffused NO3(-) sources in agricultural field, improved agricultural management practices can be implemented to protect the water resource and avoid further water quality deterioration in Taihu Lake Basin. PMID:24686140

  11. Inferring non-point pollution from land cover analysis

    SciTech Connect

    Hyde, R.F.

    1982-01-01

    The effectiveness of the agricultural Best Management Practices (BMP) used in the 3 1/2-year Indiana Heartland Model Implementation Project in controlling non-point water pollution is assessed by coordinating data from Landsat, low-altitude IR aerial photography, and field observations, using computer mapping and analysis techniques. Landsat images were found to identify urban areas, forest, and water, but to be of only limited value in differentiating grassland, pasture, and cropland. Aerial photography distinguished grassland, pasture, and cropland, but not specific crops or tillage practices. A significant correlation between subwatershed crop cover and fish populations is found, implying that measures of cropland area can be used to estimate water quality, at least insofar as it affects fish well-being. In situ studies showed that the BMP reduced erosion, sedimentation of streams, and pollution. It is suggested that future BMP programs be targeted at areas of maximum soil-erosion potential, which could be identified cost-effectively by remote-sensing techniques.

  12. Basic biogenic aerosol precursors: Agricultural source attribution of volatile amines revised

    NASA Astrophysics Data System (ADS)

    Kuhn, U.; Sintermann, J.; Spirig, C.; Jocher, M.; Ammann, C.; Neftel, A.

    2011-08-01

    Despite recent evidence on an important role of volatile amines in the nucleation of particulate matter, very scarce information is available on their atmospheric abundance and source distribution. Previous measurements in animal housings had identified livestock husbandry as the main amine source, with trimethylamine (TMA) being the key component. This has led to the assumption that the agricultural sources for amines are similar as for ammonia, emitted throughout the cascade of animal excretion, storage and application in the field. In this study, we present the first micrometeorological flux measurements as well as dynamic enclosure experiments showing that the amine source strength from stored slurry is negligible, implying significant consequences for the global amine emission inventory. In the case of cattle, amine production is attributed to the animal's rumination activity and exhalation is suggested to be an important emission pathway, similar to the greenhouse gas methane. Fodder like hay and silage also emits volatile amines, potentially assigning these alkaloid compounds a key function in enhancing particle formation in remote areas.

  13. Nitrate concentrations under irrigated agriculture

    USGS Publications Warehouse

    Zaporozec, A.

    1983-01-01

    In recent years, considerable interest has been expressed in the nitrate content of water supplies. The most notable toxic effect of nitrate is infant methemoglobinemia. The risk of this disease increases significantly at nitrate-nitrogen levels exceeding 10 mg/l. For this reason, this concentration has been established as a limit for drinking water in many countries. In natural waters, nitrate is a minor ionic constituent and seldom accounts for more than a few percent of the total anions. However, nitrate in a significant concentration may occur in the vicinity of some point sources such as septic tanks, manure pits, and waste-disposal sites. Non-point sources contributing to groundwater pollution are numerous and a majority of them are related to agricultural activities. The largest single anthropogenic input of nitrate into the groundwater is fertilizer. Even though it has not been proven that nitrogen fertilizers are responsible for much of nitrate pollution, they are generally recognized as the main threat to groundwater quality, especially when inefficiently applied to irrigated fields on sandy soils. The biggest challenge facing today's agriculture is to maintain the balance between the enhancement of crop productivity and the risk of groundwater pollution. ?? 1982 Springer-Verlag New York Inc.

  14. Nitrogen stable isotopes in streams: effects of agricultural sources and transformations.

    PubMed

    Diebel, Matthew W; Vander Zanden, M Jake

    2009-07-01

    The nitrogen stable isotope ratio of biological tissue has been proposed as an indicator of anthropogenic N inputs to aquatic ecosystems, but overlap in the isotopic signatures of various N sources and transformations make definitive attribution of processes difficult. We collected primary consumer invertebrates from streams in agricultural settings in Wisconsin, U.S.A., to evaluate the relative influence of animal manure, inorganic fertilizer, and denitrification on biotic delta15N. Variance in biotic delta15N was explained by inorganic fertilizer inputs and the percentage of wetland land cover in the watershed, but not by animal manure inputs. These results suggest that denitrification of inorganic fertilizer is the primary driver of delta15N variability among the study sites. Comparison with previously collected stream water NO3-N concentrations at the same sites supports the role of denitrification; for a given N application rate, streams with high biotic delta15N had low NO3-N concentrations. The lack of a manure signal in biotic delta15N may be due its high ammonia content, which can be dispersed outside the range of its application by volatilization. Based on our findings and on agricultural census data for the entire United States, inorganic fertilizer is more likely than manure to drive variability in biotic delta15N and to cause excessive nitrogen concentrations in streams. PMID:19688921

  15. 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

    USGS Publications Warehouse

    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

  16. Source and transport factors influencing storm phosphorus losses in agricultural catchments

    NASA Astrophysics Data System (ADS)

    Shore, Mairead; Jordan, Phil; Mellander, Per-Erik; kelly-quinn, Mary; Wall, David; Murphy, Paul; Melland, Alice

    2014-05-01

    The relative risk of diffuse phosphorus (P) loss from agricultural land was assessed in a well-drained arable catchment and a poorly-drained grassland catchment and in two nested basins within each catchment. This research investigated the relative control of hydrology and soil P on P losses between basins. Quick flow (QF) P losses (defined here as both concentrations and loads), monitored in stream flow during four storm events, were compared with a dynamic metric of transport risk (QF magnitude) and a static metric of critical source area (CSA) risk (extent of highly-connected poorly-drained soils with excess plant-available soil P). The potential for static transport metrics of soil connectivity and soil drainage class, to predict relative QF magnitudes and P losses between basins was also investigated. In basins with similar CSA risk but with contrasting QF magnitudes, mean TRP (total molybdate-reactive P) losses were consistently higher in the basins which had the highest QF magnitudes. This suggests that basin hydrology, rather than hydrology of high-P soils only, determined relative TRP losses between hydrologically contrasting basins. Furthermore, static transport metrics of soil connectivity and soil drainage class reliably discerned relative QF magnitudes and TRP losses between these basins. However, for two of the storm events (both occurring during the hydrologically active season), PP (particulate P) concentrations were frequently higher in basins which had the lowest QF magnitudes and may be attributed to a higher proportion of bare soil in these basins at these times as a result of their predominantly arable nature. In basins with similar hydrology, relative TRP and PP losses did not reflect trends in CSA risk or QF magnitude. The dynamics of TRP and PP losses and QF magnitude between these basins varied across storms, thus could not be predicted using static metrics. Where differences in hydrological dynamics were large, storm TRP losses were well

  17. Nitrate behaviors and source apportionment in an aquatic system from a watershed with intensive agricultural activities.

    PubMed

    Lu, Lu; Cheng, Hongguang; Pu, Xiao; Liu, Xuelian; Cheng, Qianding

    2015-01-01

    Nitrate pollution in aquatic systems caused by intensive agricultural activities is a serious problem in the Sanjiang Plain. In this study, a dual isotope approach (δ(15)N-NO3(-) and δ(18)O-NO3(-)) was employed to identify potential nitrate sources (atmospheric deposition, AD; NO3(-) derived from soil organic matter nitrification, NS; NO3(-) derived from chemical fertilizer nitrification, NF; and manure and sewage, M&S) and transformation processes occurring in the Abujiao River watershed located in the Sanjiang Plain. The Bayesian model (stable isotope analysis in R, SIAR) was utilized to apportion the contribution of the potential sources. In this watershed, the nitrate concentrations in the surface water were low (mean ± SD = 1.15 ± 0.84 mg L(-1)), and were greatly influenced by precipitation and land use conditions during the two sampling periods (the high flow period, September; the low flow period, November). On the contrary, in the ground water, high NO3(-) concentrations were observed (7.84 ± 5.83 mg L(-1)) and no significant temporal variation in NO3(-) was found during the sampling periods. The sampled water δ(18)O-NO3(-) values suggest that the nitrification process was not the main N cycling process, because most of the measured δ(18)O-NO3(-) values were above the expected δ(18)O-NO3(-) from nitrification throughout the sampling periods. Both the chemical and isotopic characteristics indicated that the signs of de-nitrification were absent in the surface water. However, significant de-nitrification processes were observed in the ground water for all sample periods. Results from the SIAR model showed that source contributions differed significantly during the two sampling periods. During the high flow period, chemical fertilizers and soil N fertilizer equally contributed to the major sources of nitrate in the surface water. In contrast, manure and sewage sources dominated the source contribution during the low flow period (November). This study

  18. A Description and Source Listing of Curriculum Materials in Agricultural Education, 1969-1970.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Agricultural Education Div.

    The purpose of this annotated bibliography is to provide teachers of vocational agriculture, agricultural supervisors, and agricultural teacher educators with information on current curriculum materials available to them. Classified according to the AGDEX filing system, the 163 references are grouped under the headings: (1) Field Crops, (2)…

  19. A Description and Source Listing of Curriculum Materials in Agricultural Education, 1970-1971.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Agricultural Education Div.

    To provide teachers of vocational agriculture, agricultural supervisors, and agricultural teacher educators with information on current curriculum materials available to them, this annotated bibliography presents 207 references classified according to the AGDEX filing system. Topics are: (1) Field Crops, (2) Horticulture, (3) Forestry, (4) Animal…

  20. A Description and Source Listing of Curriculum Materials in Agricultural Education. 1972-73.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Agricultural Education Div.

    Listed are 246 curriculum material items in ten categories: field crops, horticulture, forestry, animal science, soils, diseases and pests, agricultural engineering, agricultural economics, agricultural occupations, and professional. Most materials are annotated and all are classified according to the AGPEX filing system. Bibliographic and…

  1. Conducting an Agricultural Life Cycle Assessment: Challenges and Perspectives

    PubMed Central

    Caffrey, Kevin R.; Veal, Matthew W.

    2013-01-01

    Agriculture is a diverse field that produces a wide array of products vital to society. As global populations continue to grow the competition for natural resources will increase pressure on agricultural production of food, fiber, energy, and various high value by-products. With elevated concerns related to environmental impacts associated with the needs of a growing population, a life cycle assessment (LCA) framework can be used to determine areas of greatest impact and compare reduction strategies for agricultural production systems. The LCA methodology was originally developed for industrial operations but has been expanded to a wider range of fields including agriculture. There are various factors that increase the complexity of determining impacts associated with agricultural production including multiple products from a single system, regional and crop specific management techniques, temporal variations (seasonally and annually), spatial variations (multilocation production of end products), and the large quantity of nonpoint emission sources. The lack of consistent methodology of some impacts that are of major concern to agriculture (e.g., land use and water usage) increases the complexity of this analysis. This paper strives to review some of these issues and give perspective to the LCA practitioner in the field of agriculture. PMID:24391463

  2. Conducting an agricultural life cycle assessment: challenges and perspectives.

    PubMed

    Caffrey, Kevin R; Veal, Matthew W

    2013-01-01

    Agriculture is a diverse field that produces a wide array of products vital to society. As global populations continue to grow the competition for natural resources will increase pressure on agricultural production of food, fiber, energy, and various high value by-products. With elevated concerns related to environmental impacts associated with the needs of a growing population, a life cycle assessment (LCA) framework can be used to determine areas of greatest impact and compare reduction strategies for agricultural production systems. The LCA methodology was originally developed for industrial operations but has been expanded to a wider range of fields including agriculture. There are various factors that increase the complexity of determining impacts associated with agricultural production including multiple products from a single system, regional and crop specific management techniques, temporal variations (seasonally and annually), spatial variations (multilocation production of end products), and the large quantity of nonpoint emission sources. The lack of consistent methodology of some impacts that are of major concern to agriculture (e.g., land use and water usage) increases the complexity of this analysis. This paper strives to review some of these issues and give perspective to the LCA practitioner in the field of agriculture. PMID:24391463

  3. Measurement of Ambient Ammonia and Surface-level Meteorological Forcing Variables near an Agricultural Emission Source

    NASA Astrophysics Data System (ADS)

    Myles, L.; Heuer, M. W.

    2012-12-01

    Atmospheric ammonia (NH3) is a reduced form of reactive nitrogen that is primarily emitted from agricultural activities. NH3 volatilizes from animal waste and fertilized land directly into the atmosphere where it can either react with other gases to form fine particulate matter or deposit on surfaces through air-surface exchange processes. Field measurements in different ecosystems and under various conditions are necessary to improve the understanding of the complex relationships between ambient NH3 and meteorological parameters, such as temperature and relative humidity, which influence volatilization rates and ultimately, ambient concentrations near emission sources. However, the measurement of ambient NH3 is challenging. NH3 is hydroscopic and reactive, and measurement techniques are subject to errors caused by sampling artifacts and other interferences. Recent advancements have led to improved techniques that allow real-time measurement of ambient NH3. A cavity ring-down spectrometer was deployed at a cattle research facility in Knoxville, TN during spring 2012 to measure ambient NH3, and meteorological instrumentation was collocated to measure 3-D winds, temperature, relative humidity, precipitation and other parameters (z = 2 m). The study site was rolling pasture typical of the eastern Tennessee Valley and included two large barns and approximately 30-40 cattle. Daytime ambient NH3 averaged 15-20 ppb most days with lows of approximately 7 ppb at night. Higher concentrations (greater than 50 ppb) seemed to correlate with higher temperatures (greater than 27 C), although the data are not consistent. Several instances of 100 ppb concentrations were measured when temperatures were high and winds were from the direction of the barns. Overall, the study shows that ambient NH3 levels near agricultural emission sources may vary greatly with time and a variety of factors, including meteorological conditions. The data support the need for real-time measurements of NH

  4. Ammonia-oxidizer communities in an agricultural soil treated with contrasting nitrogen sources

    PubMed Central

    Habteselassie, Mussie Y.; Xu, Li; Norton, Jeanette M.

    2013-01-01

    The community of ammonia-oxidizing prokaryotes was examined in an agricultural soil treated for six seasons with contrasting nitrogen (N) sources. Molecular tools based on the genes encoding ammonia monooxygenase were used to characterize the ammonia oxidizer (AO) communities and their abundance. Soil DNA was extracted from soils sampled from silage corn plots that received no additional N (control), dairy waste compost, liquid dairy waste (LW), and ammonium sulfate (AS) treatments at approximately 100 and 200 kg available N ha-1 over 6 years. The N treatment affected the quantity of AO based on estimates of amoA by real-time PCR. Ammonia oxidizing bacteria (AOB) were higher in soils from the AS200, AS100, and LW200 treatments (2.5 × 107, 2.5 × 107, and 2.1 × 107copies g-1 soil, respectively) than in the control (8.1 × 106 copies g-1 soil) while the abundance of amoA encoding archaea [ammonia oxidizing archaea (AOA)] was not significantly affected by treatment (3.8 × 107 copies g-1 soil, average). The ratio of AOA/AOB was higher in the control and compost treated soils, both treatments have the majority of their ammonium supplied through mineralization of organic nitrogen. Clone libraries of partial amoA sequences indicated AOB related to Nitrosospira multiformis and AOA related to uncultured Nitrososphaera similar to those described by soil fosmid 54d9 were prevalent. Profiles of the amoC-amoA intergenic region indicated that both Nitrosospira- and Nitrosomonas-type AOB were present in all soils examined. In contrast to the intergenic amoC-amoA profile results, Nitrosomonas-like clones were recovered only in the LW200 treated soil-DNA. The impact of 6 years of contrasting nitrogen sources applications caused changes in AO abundance while the community composition remained relatively stable for both AOB and AOA. PMID:24223575

  5. Unaccounted variability in NH3 agricultural sources detected by IASI contributing to European spring haze episode

    NASA Astrophysics Data System (ADS)

    Fortems-Cheiney, A.; Dufour, G.; Hamaoui-Laguel, L.; Foret, G.; Siour, G.; Van Damme, M.; Meleux, F.; Coheur, P.-F.; Clerbaux, C.; Clarisse, L.; Favez, O.; Wallasch, M.; Beekmann, M.

    2016-05-01

    Ammonia (NH3), whose main source in the troposphere is agriculture, is an important gaseous precursor of atmospheric particulate matter (PM). We derived daily ammonia emissions using NH3 total columns measured from the Infrared Atmospheric Sounding Interferometer (IASI) on board Metop-A, at a relatively high spatial resolution (grid cell of 0.5° × 0.5°). During the European spring haze episodes of 24-31 March 2012 and 8-15 March 2014, IASI reveals NH3 total column magnitudes highlighting higher NH3 emissions over central Europe (especially over Germany, Czech Republic, and eastern France) from the ones provided by the European reference European Monitoring and Evaluation Programme inventory. These ammonia emissions exhibit in addition a large day-to-day variability, certainly due to spreading practices. The increase of NH3 emissions in the model, that reaches +300% locally, leads to an increase of both NH3 and PM2.5 surface concentrations and allows for a better comparison with independent measurements (in terms of bias, root-mean-square error, and correlation). This study suggests that there are good prospects for better quantifying NH3 emissions by atmospheric inversions.

  6. GEMAS: Mercury in European agricultural and grazing land soils - sources and environmental risk

    NASA Astrophysics Data System (ADS)

    Tore Ottesen, Rolf; Birke, Manfred; Gosar, Mateja; Reimann, Clemens

    2014-05-01

    Agricultural (Ap, Ap-horizon, 0-20 cm) and grasing land soil samples (Gr, 0-10 cm) were collected from a large part of Europe (33 countries, 5.6 million km2) at an average density of 1 sample site/2500 km2. The resulting more than 2 x 2000 soil samples were air dried, sieved to <2 mm and analysed for their Hg concentrations following an aqua regia extraction. Median concentrations for Hg are 0.030 mg/kg (range: <0.003 - 1.56 mg/kg) for the Ap samples and 0.035 mg/kg (range:<0.003 - 3.12 mg/kg) for the Gr samples. Only 5 Ap and 10 Gr samples returned Hg concentrations above 0.5 mg/kg. In the geochemical maps the continental-scale distribution of the element is clearly dominated by geology. Climate plays also an important role, Hg accumulates in those areas of northern Europe where a wet and cold climate favors the build-up of organic material. Typical anthropogenic sources like coal fired power plants, chlor-alkaline factories, metal smelters and urban agglomerations are hardly visible at the continental scale but can have a major impact at the local scale.

  7. Developing unique tracers to distinguish nutrient contributions from agriculture and wastewater sources in the Choptank River and Anacostia River watersheds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eutrophication is a major problem for the Chesapeake Bay ecosystem. The efficacy of the restoration efforts implemented is restricted by the inability to differentiate nutrient sources. This study assessed the use of stable tracers in order to discriminate between urban and agricultural nutrient sou...

  8. Studies by the U.S. Geological Survey on sources, transport, and fate of agricultural chemicals

    USGS Publications Warehouse

    Capel, Paul D.; Hamilton, Pixie A.; Erwin, Martha L.

    2004-01-01

    Information from these studies will help with decision-making related to chemical use, conservation, and other farming practices that are used to reduce runoff of agricultural chemicals and sediment from fields. This information also will benefit the U.S. Environmental Protection Agency, the Department of Agriculture, local and regional water managers, and agricultural chemical manufacturers who are involved in managing chemical use and pesticide registration.

  9. Re-examining the basis for source discrimination and data corrections used by sediment fingerprinting studies in agricultural catchments

    NASA Astrophysics Data System (ADS)

    Smith, Hugh; Blake, Will

    2014-05-01

    The sediment fingerprinting technique has been widely used in agricultural catchments to quantify fine sediment contributions from various land use sources. This application of the technique depends on the key assumption that land-use source signatures imprinted on catchment soils are decipherable from those due to other landscape factors affecting soil and sediment properties. We re-examine this key assumption by investigating (i) the physical and chemical basis for source discrimination and (ii) potential factors that may confound source un-mixing in agricultural catchments, including particle size and organic matter effects on tracer properties. The study is situated in the River Tamar, a predominantly agricultural catchment in south-west England that has also been affected by mining. Source discrimination focused on pasture and cultivated land uses and channel banks. Monthly, time-integrated suspended sediment samples were collected across seven catchments for a 12-month period. Physical and chemical properties measured in source soils and sediment included fallout radionuclides, major and minor element geochemical constituents, total organic carbon and particle size. Source discrimination was entirely dependent on differences in tracer property concentrations between surface and sub-surface soils. This is based on fallout radionuclide concentrations that are surface-elevated, while many geochemical properties are surface-depleted due to weathering and pedogenetic effects, although surface soil contamination can reverse this trend. Source discrimination in the study catchments was limited by (i) rotation of cultivated and pasture fields resulting in reduced differences between these two sources and (ii) the cultivated source signature resembling a mix of the pasture and channel bank sources for many tracer properties. Furthermore, metal pollution from abandoned historic mines and organic enrichment of sediment from areas of peaty soil resulted in the non

  10. Quantifying sediment sources in a lowland agricultural catchment pond using (137)Cs activities and radiogenic (87)Sr/(86)Sr ratios.

    PubMed

    Le Gall, Marion; Evrard, Olivier; Foucher, Anthony; Laceby, J Patrick; Salvador-Blanes, Sébastien; Thil, François; Dapoigny, Arnaud; Lefèvre, Irène; Cerdan, Olivier; Ayrault, Sophie

    2016-10-01

    Soil erosion often supplies high sediment loads to rivers, degrading water quality and contributing to the siltation of reservoirs and lowland river channels. These impacts are exacerbated in agricultural catchments where modifications in land management and agricultural practices were shown to accelerate sediment supply. In this study, sediment sources were identified with a novel tracing approach combining cesium ((137)Cs) and strontium isotopes ((87)Sr/(86)Sr) in the Louroux pond, at the outlet of a lowland cultivated catchment (24km(2), Loire River basin, France) representative of drained agricultural areas of Northwestern Europe. Surface soil (n=36) and subsurface channel bank (n=17) samples were collected to characterize potential sources. Deposited sediment (n=41) was sampled across the entire surface of the pond to examine spatial variation in sediment deposits. In addition, a 1.10m sediment core was sampled in the middle of the pond to reconstruct source variations throughout time. (137)Cs was used to discriminate between surface and subsurface sources, whereas (87)Sr/(86)Sr ratios discriminated between lithological sources. A distribution modeling approach quantified the relative contribution of these sources to the sampled sediment. Results indicate that surface sources contributed to the majority of pond (μ 82%, σ 1%) and core (μ 88%, σ 2%) sediment with elevated subsurface contributions modeled near specific sites close to the banks of the Louroux pond. Contributions of the lithological sources were well mixed in surface sediment across the pond (i.e., carbonate sediment contribution, μ 48%, σ 1% and non-carbonate sediment contribution, μ 52%, σ 3%) although there were significant variations of these source contributions modeled for the sediment core between 1955 and 2013. These fluctuations reflect both the progressive implementation of land consolidation schemes in the catchment and the eutrophication of the pond. This original sediment

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Removal of Nitrogen and Pathogens in Agricultural or Urban Channles using Engineered Streambeds

    NASA Astrophysics Data System (ADS)

    McCray, J. E.; Herzog, S.; Higgins, C. P.

    2015-12-01

    Treating non-point source pollution is one of our greatest challenges in environmental hydrology. Previous efforts in agricultural or urban settings have focused on removing sources or implementing distributed best management practices (BMPs) throughout a watershed. However, for stream pollution, the most efficient point of treatment would be within the stream itself, which integrates flows from the entire watershed. Engineered streambed modifications in urban or agricultural streams and constructed channels have the potential to mitigate nonpoint source pollution. Geomedia designed to treat water pollutants and achieve an optimal residence time via hydraulic conductivity modifications are termed biohydrochemical enhancement structures for stream water treatment (BEST). BEST modules can efficiently drive interchange, attenuating nutrients and pathogens (and can be designed to remove other pollutants such as phosphorus, metals or trace organics). Numerical models, combined with data from bench-top and 2D experiments, demonstrate effective contaminant removal potential for practical applications. Nitrogen and pathogens could be attenuated within a series of BEST on the order of 50 m of stream length, and at a favorable cost compared to traditional BMPs, suggesting that BEST could be an effective best management practice for constructed stormwater channels (particularly outlets of detention ponds) or channels carrying irrigation return flows. New results from a constructed stream demonstrate the real-world applicability of the BEST system.

  13. Characterizing the ozone formation potential of agricultural sources in California's San Joaquin Valley: A computational and experimental approach

    NASA Astrophysics Data System (ADS)

    Howard, Cody Jerome

    The global pattern of expanding urban centers and increasing agricultural intensity is leading to more frequent interactions between air pollution emissions from urban and agricultural sources. The confluence of these emissions that traditionally have been separated by hundreds of kilometers is creating new air quality challenges in numerous regions across the United States. An area of particular interest is California's San Joaquin Valley (SJV), which has an agricultural output higher than many countries, a rapidly expanding human population, and ozone concentrations that are already higher than many dense urban areas. New regulations in the SJV restrict emissions of reactive organic gases (ROG) from animal sources in an attempt to meet Federal and State ozone standards designed to protect human health. A transportable "smog" chamber was developed and tested to directly measure the ozone formation potential of a variety of agricultural emissions in representative urban and rural atmospheres. After validation of the experimental procedure, four animal types were examined: beef cattle, dairy cattle, swine, and poultry, as well as six commonly used animal feeds: cereal silage (wheat grain and oat grain), alfalfa silage, corn silage, high moisture ground corn, almond shells, almond hulls, and total mixed ration. The emitted ROG composition was also measured so that the theoretical incremental reactivity could be calculated for a variety of atmospheres and directly compared with the measured ozone formation potential (OFP) under the experimental conditions. A computational model was created based on a modified form of the Caltech Atmospheric Chemistry Mechanism and validated against experimental results. After validation, the computational model was used to predict OFP across a range of NOx and ROG concentrations. The ROG OFP measurements combined with adjusted agricultural ROG emissions inventory estimates were used to predict the actual ozone production in the SJV

  14. Information technology and innovative drainage management practices for selenium load reduction from irrigated agriculture to provide stakeholder assurances and meet contaminant mass loading policy objectives

    SciTech Connect

    Quinn, N.W.T.

    2009-10-15

    Many perceive the implementation of environmental regulatory policy, especially concerning non-point source pollution from irrigated agriculture, as being less efficient in the United States than in many other countries. This is partly a result of the stakeholder involvement process but is also a reflection of the inability to make effective use of Environmental Decision Support Systems (EDSS) to facilitate technical information exchange with stakeholders and to provide a forum for innovative ideas for controlling non-point source pollutant loading. This paper describes one of the success stories where a standardized Environmental Protection Agency (EPA) methodology was modified to better suit regulation of a trace element in agricultural subsurface drainage and information technology was developed to help guide stakeholders, provide assurances to the public and encourage innovation while improving compliance with State water quality objectives. The geographic focus of the paper is the western San Joaquin Valley where, in 1985, evapoconcentration of selenium in agricultural subsurface drainage water, diverted into large ponds within a federal wildlife refuge, caused teratogenecity in waterfowl embryos and in other sensitive wildlife species. The fallout from this environmental disaster was a concerted attempt by State and Federal water agencies to regulate non-point source loads of the trace element selenium. The complexity of selenium hydrogeochemistry, the difficulty and expense of selenium concentration monitoring and political discord between agricultural and environmental interests created challenges to the regulation process. Innovative policy and institutional constructs, supported by environmental monitoring and the web-based data management and dissemination systems, provided essential decision support, created opportunities for adaptive management and ultimately contributed to project success. The paper provides a retrospective on the contentious planning

  15. Nitrate-nitrogen and oxygen isotope ratios for identification of nitrate sources and dominant nitrogen cycle processes in a tile-drained dryland agricultural field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural systems are a leading source of reactive nitrogen to aquatic and atmospheric ecosystems. Natural d15Nnitrate and d18Onitrate are used to identify the dominant nitrogen cycle processes and sources of NO3- leached from a tile-drained, dryland agricultural field. Tile-drain water discharge...

  16. Making Our Nonpoint Source Pollution Education Programs Effective.

    ERIC Educational Resources Information Center

    Shepard, Robin

    1999-01-01

    The rate of adoption of nutrient management by farmers in Wisconsin watersheds was compared for a program using diffuse communication strategies and one using one-to-one information transfer. Information transfer increased adoption of specific practices and decreased application of excessive nitrogen and phosphorus. (SK)

  17. Nonpoint Source Road Salt Pollution from Urban Stormwater

    NASA Astrophysics Data System (ADS)

    DeGaetano, S.; Walter, M. T.

    2014-12-01

    In colder climates, such as the Northeast, road salts are commonly applied to deice roads in order to increase pedestrian and driver safety. This study was conducted to establish the mass if NaCl entering the local aquatic systems from Cornell's campus. Using trail cameras, two typical storm water pipes (draining into Cascadilla Creek) were monitored to determine the volume of runoff on an hourly bases. Grab samples were taken three times a week obtain storm water chloride concentration. In general, the average measured salt concentration was found to be 3.61 g/L, while high precipitation events Cl- concentration spiked to levels exceeding 12 g/L (≈ 20 g/L of salt). Combining runoff volumes and salt concentration values, a mass per drainage area was calculated for each monitored pipe. Outfall #1, located just upstream from the Wilson Synchrotron Module, expelled 262,300 kg of salt over a 42-day period of data collection while Outfall#2 discharged 4160 kg during the same period. These results were averaged and then applied to the total impervious area on Cornell's campus to approximate the total mass of sodium chloride leaving campus during the period of data collection.

  18. BETTER ASSESSMENT SCIENCE INTEGRATING POINT AND NONPOINT SOURCES (BASINS)

    EPA Science Inventory

    BASINS IS A NEW TOOL WHICH INTEGRATES ENVIRONMENTAL DATA, GIS (ARCVIEW) AND MODELING TOOLS ON YOUR PC. BASINS INTEGRATES DATA ON WATER QUALITY FROM STORET AND DATA ON AQUATIC RESOURCES TO HELP IDENTIFY WATERBODIES WHICH MAY NOT BE MEETING WATER QUALITY STANDARDS. THE TOOL ALSO I...

  19. Nonpoint source groundwater pollution and endogenous regulatory policies

    NASA Astrophysics Data System (ADS)

    Lee, Donna J.; Kim, C. S.

    2002-12-01

    Theory suggests that in the absence of transaction costs, pollution externalities can be mitigated efficiently by charging polluters a tax equal to the marginal social cost of pollution. All other regulatory mechanisms therefore may be no more efficient than a marginal cost pollution tax. We developed a stylized model of dynamic groundwater pollution without transaction costs to examine alternate policies. Using mitigation cost, tax burden, and excess burden we compared the relative efficiency of each tax policy under competitive market conditions. For groundwater nitrate pollution in a Midwestern farming region, results show that the least cost policy is a constant tax on the polluting input, followed by a variable tax on the polluting input and a pollution tax.

  20. Evaluation of nonpoint-source contamination, Wisconsin: water year 1999

    USGS Publications Warehouse

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

    2001-01-01

    For two of the eight rural streams (Rattlesnake and Kuenster Creeks) minimal BMP implementation has occurred, hence a comparison of pre- BMP and data collected after BMP implementation began is not warranted. For two other rural streams (Brewery and Garfoot Creeks), BMP implementation is complete. For the four remaining rural streams (Bower, Otter, Eagle, and Joos Valley Creeks), the pre-BMP load data were compared to the transitional data to determine if significant reductions in the loads have occurred as a result of the BMP implementation to date. For all sites, the actual constituent loads for suspended solids and total phosphorus exhibit no statistically significant reductions after BMP installation. Multiple regressions were used to remove some of the natural variability in the data. Based on the residual analysis, for Otter Creek, there is a significant difference in the suspended-solids regression residuals between the pre-BMP and transitional periods, indicating a potential reduction as a result of the BMP implementation after

  1. Characteristic and potential sources of polychlorinated dibenzo-P-dioxins and dibenzofurans in agricultural soils in Beijing, China.

    PubMed

    Li, Wei; Li, Chaoqin; Chen, Zuosheng; Cai, Zongwei

    2014-09-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in 25 background and 80 agricultural soil samples collected from 21 sites in Beijing, China. The levels of PCDD/Fs in the north agricultural soils were low (0.15-0.58 ng international toxic equivalent quantity [I-TEQ]/kg), which were comparable with those of the background soils (0.091-0.35 ng I-TEQ/kg). In the southern agricultural soils, however, concentrations were several times higher (0.27-3.3 ng I-TEQ/kg). Comparison of PCDD/Fs congener compositions between possible sources and samples indicated that agricultural soils in Beijing had not been contaminated by the 3 main PCDD/F contamination sources in China--ferrous and nonferrous metal, waste incineration, and power generation. They had, however, been slightly contaminated by the impurities of some organochlorine pesticides, such as sodium pentachlorophenate, and by open burning of biomass, vehicle exhaust, atmospheric deposition, sediment, and sewage sludge. These results have been supported by the principal components analysis. PMID:24863628

  2. EFFECTS OF LIVESTOCK PASTURING ON NONPOINT SURFACE RUNOFF

    EPA Science Inventory

    This project was initiated to evaluate the effects of livestock pasturing in the humid regions of the United States on the quality of nonpoint surface runoff. Three pasturing regimes which are more commonly practiced in the corn belt states were evaluated to determine their poten...

  3. Cattle, clean water, and climate change: policy choices for the Brazilian Agricultural Frontier.

    PubMed

    Bell, Andrew Reid; Lemos, Maria Carmen; Scavia, Donald

    2010-11-15

    In the Amazonian agricultural frontier, pasture for cattle ranching is an important and potentially hazardous form of land use because of sediment erosion as pastures degrade. This relationship between ranching, sediment load, and water quality is likely to further exacerbate environmental impacts, particularly in the context of climate change. We examine the role that river basin councils (RBCs) - a water governance option of Brazil's 1997 National Water Act - might play in managing this nonpoint-source pollution in the Amazônian state of Rondônia. We implement a simple coupled rancher-water system model to compare two potential governance options: a bulk water cleanup charge (BWC) implemented by RBCs and a land-use fine (LUF) for failing to maintain riparian buffers. We find no significant advantage of BWC over LUF in reducing sediment loading while keeping ranching profitable, under a changing climate. We also fail to find in Rondônia the important stake in water issues that has driven water reform elsewhere in Brazil. Moreover, the comparative success of reforestation programs suggests these programs may, in fact, have the potential to manage nonpoint-source agricultural pollution in the region. PMID:20961050

  4. Agricultural sources of contaminants of emerging concern and adverse health effects on freshwater fish

    USGS Publications Warehouse

    Tillitt, Donald E.; Buxton, Herbert T.

    2011-01-01

    Agricultural contaminants of emerging concern (CECs) are generally thought of as certain classes of chemicals associated with animal feeding and production facilities. Veterinary pharmaceuticals used in animal food production systems represent one of the largest groups of CECs. In our review, we discuss the extensive increase in use of antibiotics in animal feeding operations (AFOs) around the world. AFOs are a major consumer of antibiotics and other veterinary pharmaceuticals and over the past decade there has been growing information on the occurrence, release, and fate of CECs from animal food production operations, including the application of pharmaceutical-containing manure to agricultural fields and releases from waste lagoons. Concentrations of CECs in surface and ground water in proximity to AFOs correspond to their presence in the AFO wastes. In many cases, the environmental concentrations of agriculturally-derived CECs are below toxicity thresholds. Hormones and hormone replacement compounds are a notable exception, where chemical concentrations near AFOs can exceed concentrations known to cause adverse effects on endocrine-related functions in fish. In addition, some agricultural pesticides, once thought to be safe to non-target organisms, have demonstrated endocrine-related effects that may pose threats to fish populations in agricultural regions. That is, we have pesticides with emerging concerns, thus, the concern is emerging and not necessarily the chemical. In this light, one must consider certain agricultural pesticides to be included in the list of CECs. Even though agricultural pesticides are routinely evaluated in regulatory testing schemes which have been used for decades, the potential hazards of some pesticides have only recently been emerging. Emerging concerns of pesticides in fish include interference with hormone signaling pathways; additive (or more than additive) effects from pesticide mixtures; and adverse population-level effects at

  5. Multivariate and geostatistical analyses of the spatial distribution and sources of heavy metals in agricultural soil in Dehui, Northeast China.

    PubMed

    Sun, Chongyu; Liu, Jingshuang; Wang, Yang; Sun, Liqiang; Yu, Hongwen

    2013-07-01

    The characterization of the content and source of heavy metals in soils are necessary to establish quality standards on a regional level and to assess the potential threat of metals to food safety and human health. The surface horizons of 114 agricultural soils in Dehui, a representative agricultural area in the black soil region, Northeast China, were collected and the concentrations of Cr, Ni, Cu, Zn, and Pb were analyzed. The mean values of the heavy metals were 49.7 ± 7.04, 20.8 ± 3.06, 18.9 ± 8.51, 58.9 ± 7.16, and 35.4 ± 9.18 mg kg(-1) for Cr, Ni, Cu, Zn, and Pb, respectively. Anthropic activities caused an enrichment of Cu and Pb in soils. However, metal concentrations in all samples did not exceed the guideline values of Chinese Environmental Quality Standard for Soils. Multivariate and geostatistical analyses suggested that soil Cr, Ni, and Zn had a lithogenic origin. Whereas, the elevated Cu concentrations in the study area were associated with industrial and agronomic practices, and the main sources of Pb were industrial fume, coal burning exhausts, and domestic waste. Source identification of heavy metals in agricultural soil is a basis for undertaking appropriate action to reduce metal inputs. PMID:23608467

  6. Investigating the sources of sediment in a Canadian agricultural watershed using a colour-based fingerprinting technique

    NASA Astrophysics Data System (ADS)

    Barthod, Louise; Lobb, David; Owens, Philip; Martinez-Carreras, Nuria; Koiter, Alexander; Petticrew, Ellen; McCullough, Gregory

    2014-05-01

    The development of beneficial management practises to minimize adverse impacts of agriculture on soil and water quality requires information on the sources of sediment at the watershed scale. Sediment fingerprinting allows for the determination of sediment sources and apportionment of their contribution within a watershed, using unique physical, radiochemical or biogeochemical properties, or fingerprints, of the potential sediment sources. The use of sediment colour as a fingerprint is an emerging technique that can provide a rapid and inexpensive means of investigating sediment sources. This technique is currently being utilized to determine sediment sources within the South Tobacco Creek Watershed, an agricultural watershed located in the Canadian prairies (south-central Manitoba). Suspended sediment and potential source (topsoil, channel bank and shale bedrock material) samples were collected between 2009 and 2011 at six locations along the main stem of the creek. Sample colour was quantified from diffuse reflectance spectrometry measurements over the visible wavelength range using a spectroradiometer (ASD Field Spec Pro, 400-2500 nm). Sixteen colour coefficients were derived from several colour space models (CIE XYZ, CIE xyY, CIE Lab, CIE Luv, CIE Lch, Landsat RGB, Redness Index). The individual discrimination power of the colour coefficients, after passing several prerequisite tests (e.g., linearly additive behaviour), was assessed using discriminant function analysis. A stepwise discriminant analysis, based on the Wilk's lambda criterion, was then performed in order to determine the best-suited colour coefficient fingerprints which maximized the discrimination between the potential sources. The selected fingerprints classified the source samples in the correct category 86% of the time. The misclassification is due to intra-source variability and source overlap which can lead to higher uncertainty in sediment source apportionment. The selected fingerprints

  7. Sediment sources in a small agricultural catchment: A composite fingerprinting approach based on the selection of potential sources

    NASA Astrophysics Data System (ADS)

    Zhou, Huiping; Chang, Weina; Zhang, Longjiang

    2016-08-01

    Fingerprinting techniques have been widely used as a reasonable and reliable means for investigating sediment sources, especially in relatively large catchments in which there are significant differences in surface materials. However, the discrimination power of fingerprint properties for small catchments, in which the surface materials are relatively homogeneous and human interference is marked, may be affected by fragmentary or confused source information. Using fingerprinting techniques can be difficult, and there is still a need for further studies to verify the effectiveness of such techniques in these small catchments. A composite fingerprinting approach was used in this study to investigate the main sources of sediment output, as well as their relative contributions, from a small catchment (30 km2) with high levels of farming and mining activities. The impact of the selection of different potential sediment sources on the derivation of composite fingerprints and its discrimination power were also investigated by comparing the results from different combinations of potential source types. The initial source types and several samples that could cause confusion were adjusted. These adjustments improved the discrimination power of the composite fingerprints. The results showed that the composite fingerprinting approach used in this study had a discriminatory efficiency of 89.2% for different sediment sources and that the model had a mean goodness of fit of 0.90. Cultivated lands were the main sediment source. The sediment contribution of the studied cultivated lands ranged from 39.9% to 87.8%, with a mean of 76.6%, for multiple deposited sediment samples. The mean contribution of woodlands was 21.7%. Overall, the sediment contribution from mining and road areas was relatively low. The selection of potential sources is an important factor in the application of fingerprinting techniques and warrants more attention in future studies, as is the case with other

  8. SEPARATING SPATIAL AND TEMPORAL SOURCES OF VARIATION FOR MODEL TESTING IN PRECISION AGRICULTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Applying crop simulation models to precision agriculture appears to be a matter of developing spatial suites of input parameters and running a model for each set. Extensive modeling literature has reported independent tests in multiple combinations of variety, soils, and climate, which has been gene...

  9. Using lidar to characterize particles from point and diffuse sources in an agricultural field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lidar (LIght Detection And Ranging) provides the means to quantitatively evaluate the spatial and temporal variability of particulate emissions from agricultural activities. Aglite is a three-wavelength portable scanning lidar system built at the Energy Dynamics Laboratory (EDL) to measure the spati...

  10. A Description and Source Listing of Curriculum Materials in Agricultural Education, 1971-1972.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Agricultural Education Div.

    Members of the Curriculum Materials Committee collect materials available to them prior to each American Vocational Association Meeting. The resulting bibliography contains current, non-commercial materials developed by persons in vocational education in agriculture for use in that field, but of interest beyond the state in which it was developed.…

  11. A DESCRIPTION AND SOURCE LISTING OF PROFESSIONAL INFORMATION IN AGRICULTURAL EDUCATION, 1963-64.

    ERIC Educational Resources Information Center

    SLEDGE, GEORGE W.; AND OTHERS

    BRIEF ANNOTATIONS ARE GIVEN FOR MANY OF THE 107 REFERENCES LISTED UNDER THE FOLLOWING CATEGORIES -- (1) ADULT EDUCATION, (2) AGRICULTURAL ENGINEERING, (3) ANIMAL SCIENCE, (4) CURRICULUM DEVELOPMENT AND CURRICULUM IN CROPS, ENTOMOLOGY, FARM MANAGEMENT, FARM MECHANICS, AND LIVESTOCK, (5) FARM BUSINESS MANAGEMENT AND MARKETING, (6) FORESTRY, (7)…

  12. Human-, Ovine-, and Bovine-Specific Viral Source Tracking Tools to Discriminate Between the Major Fecal Sources in Agricultural Waters.

    PubMed

    Rusiñol, Marta; Moriarty, Elaine; Lin, Susan; Bofill-Mas, Sílvia; Gilpin, Brent

    2016-03-01

    This study evaluated the sources of fecal contamination in different river catchments, using a combination of microbial source tracking tools, for human, ruminant, ovine and bovine livestock, in order to define appropriate water management strategies. Every source of waterway pollution was evaluated in river water samples from one urban river catchment and two important farming regions in New Zealand. Fecal pollution was initially measured by testing Escherichia coli and evaluating the presence of human- and ruminant-associated DNA markers of Bacteroidales (BiAdo, BacHum-UCD, BacH, and BacR) and human and ruminant fecal sterols/stanols ratios. Then specific fecal pollution sources were assessed with previously reported quantitative PCR assays targeting human-, bovine-, and ovine-specific viruses: human adenoviruses (HAdV), human JC polyomaviruses, bovine polyomaviruses (BPyV), and ovine polyomaviruses (OPyV). High level of ruminant fecal contamination was detected all over the farming areas, whereas no ruminant sources were identified in the urban river sampling sites. BacR was the most frequently observed ruminant marker and OPyV and BPyV allowed the identification of ovine and bovine fecal sources. The human fecal viral marker (HAdV) was the most frequently observed human marker, highly abundant in the urban sites, and also present in farming areas. This is the first study using simultaneously the ovine and the bovine viral markers to identify and quantify both bovine and ovine fecal pollution. PMID:26607578

  13. Interactively Improving Agricultural Field Mapping in Sub-Saharan Africa with Crowd-Sourcing and Active Learning

    NASA Astrophysics Data System (ADS)

    Debats, S. R.; Estes, L. D.; Caylor, K. K.

    2015-12-01

    As satellite imagery becomes increasingly available, management of large image databases becomes more important for efficient image processing. We have developed a computer vision-based classification algorithm to distinguish smallholder agricultural land cover in Sub-Saharan Africa, using a group of high-resolution images from South Africa as a case study. For supervised classification, smallholder agriculture, with ambiguous patterns of small, irregular fields, requires a wide range of training data samples to adequately describe the variability in appearance. We employ crowd-sourcing to obtain new training data to expand the geographic range of our algorithm. A crowd-sourcing user is asked to hand-digitize the boundaries of agricultural fields in an assigned 1 km2 image. Yet random assignment of images to users could result in a highly redundant training data set with limited discriminative power. Furthermore, larger training data sets require a greater number of users to hand-digitize fields, which increases costs through crowd-sourcing engines like Amazon Mechanical Turk, as well as longer algorithm training times, which increases computing costs. Therefore, we employ an active learning approach to interactively select the most informative images to be hand-digitized for training data by crowd-sourcing users, based on changes in algorithm accuracy. We investigate the use of various image similarity measures used in content-based image retrieval systems, which quantify the distance, such as Euclidean distance or Manhattan distance, between a variety of extracted feature spaces to determine how similar the content of two images are. We determine the minimum training data set needed to maximize algorithm accuracy, as well as automate the selection of additional training images to classify a new target image that expands the geographic range of our algorithm.

  14. Source apportionment of groundwater pollutants in Apulian agricultural sites using multivariate statistical analyses: case study of Foggia province

    PubMed Central

    2012-01-01

    Background Ground waters are an important resource of water supply for human health and activities. Groundwater uses and applications are often related to its composition, which is increasingly influenced by human activities. In fact the water quality of groundwater is affected by many factors including precipitation, surface runoff, groundwater flow, and the characteristics of the catchment area. During the years 2004-2007 the Agricultural and Food Authority of Apulia Region has implemented the project “Expansion of regional agro-meteorological network” in order to assess, monitor and manage of regional groundwater quality. The total wells monitored during this activity amounted to 473, and the water samples analyzed were 1021. This resulted in a huge and complex data matrix comprised of a large number of physical-chemical parameters, which are often difficult to interpret and draw meaningful conclusions. The application of different multivariate statistical techniques such as Cluster Analysis (CA), Principal Component Analysis (PCA), Absolute Principal Component Scores (APCS) for interpretation of the complex databases offers a better understanding of water quality in the study region. Results Form results obtained by Principal Component and Cluster Analysis applied to data set of Foggia province it’s evident that some sampling sites investigated show dissimilarities, mostly due to the location of the site, the land use and management techniques and groundwater overuse. By APCS method it’s been possible to identify three pollutant sources: Agricultural pollution 1 due to fertilizer applications, Agricultural pollution 2 due to microelements for agriculture and groundwater overuse and a third source that can be identified as soil run off and rock tracer mining. Conclusions Multivariate statistical methods represent a valid tool to understand complex nature of groundwater quality issues, determine priorities in the use of ground waters as irrigation water

  15. Sulphate leaching from diffuse agricultural and forest sources in a large central European catchment during 1900-2010.

    PubMed

    Kopáček, Jiří; Hejzlar, Josef; Porcal, Petr; Posch, Maximilian

    2014-02-01

    Using dynamic, mass budget, and empirical models, we quantified sulphate-sulphur (SO4-S) leaching from soils in a large central European catchment (upper Vltava river, Czech Republic) over a 110-year period (1900-2010). SO4-S inputs to soils with synthetic fertilisers and atmospheric deposition increased in the 1950s-1980s, then rapidly decreased (~80%), and remained low since the middle 1990s. The proportion of drained agricultural land rapidly increased from 4 to 43% between the 1950s and 1990s; then the draining ability of the system slowly decreased due to its ageing. Sulphate concentrations in the Vltava exhibited similar trends as the external SO4-S inputs, suggesting that they could be explained by changes in atmospheric and fertiliser S inputs. The available data and modelling, however, showed that (i) internal SO4-S sources (mineralization of soil organic S in the drained agricultural land), (ii) a hysteresis in SO4-S leaching from forest soils (a net S retention at the high S inputs and then a net release at the lowered inputs), and (iii) hydrology must be taken into account. An empirical model was then employed, based on parameters representing hydrology (discharge), external SO4-S sources (inputs by synthetic fertilisers and atmospheric deposition), and internal SO4-S sources (mineralization related to soil drainage). The model explained 84% of the observed variability in annual SO4-S concentrations in the Vltava river during 1900-2010 and showed that forest soils were a net sink (105 kg ha(-1)) while agricultural land was a net source (55 kg ha(-1)) of SO4-S during 1960-2010. In the late 1980s, forest soils changed from a sink to a source of S, and the present release of SO4-S accumulated in forest soils thus delays recovery of surface waters from acidification, while S losses from agricultural soils increase the risk of future S deficiency in S-demanding crops. PMID:24176702

  16. Understanding Multifunctional Agricultural Land by Using Low Cost and Open Source Solutions to Quantify Ecosystem Function and Services

    NASA Astrophysics Data System (ADS)

    Forsmoo, Joel; Anderson, Karen; Brazier, Richard; Macleod, Kit; Wilkinson, Mark

    2016-04-01

    There is a need to advance our understanding of how the spatial structure of farmed landscapes contributes to the provision of functions and services. Agricultural land is of critical importance in NW Europe, covering large parts of NW Europe's temperate land. Moreover, these agricultural areas are primarily intensively managed, with a focus on maximizing food and fibre production. Such landscapes therefore can provide a wealth of ecosystem goods and services (ESs) including regulation of climate, erosion regulation, hydrology, water quality, nutrient cycling and biodiversity conservation. However, it has been shown they are key sources of sediment, phosphorous, nitrogen and storm runoff contributing to flooding, and therefore it is likely that most agricultural landscapes do not maximize the services or benefits that they might provide. The focus of this study is the spatio-temporal assessment of carbon sequestration (particularly through proxies such as above-ground biomass) and hydrological processes on agricultural land. Understanding and quantifying both of these is important to (a) inform payments for ecosystem services frameworks, (b) evaluate and improve carbon sequestration models, (c) manage the flood risk, (d) downstream water security and (e) water quality. Quantifying both of these ESs is dependent on data describing the fine spatial and temporal structure and function of the landscape. Common practice has been to use remote sensing techniques, e.g. satellites, providing coarse spatial resolution (around 30cm at 20° off nadir) and/or temporal resolution (around 5 days revisit time at <20° off nadir). In this paper we will explain how imaging data from lightweight and easily deployed unmanned aerial vehicles (UAVs) can be used to generate structure from motion (SFM) products describing the very fine detailed (<3 cm pixel resolution) structure of the agricultural environment. We will demonstrate how these products can be delivered using advanced free

  17. Critical source area management of agricultural phosphorus: experiences, challenges and opportunities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concept of critical source areas of phosphorus (P) loss produced by coinciding source and transport factors has been studied since the mid 1990s. It is widely recognized that identification of such areas has led to targeting of management strategies and conservation practices that more effectiv...

  18. Understanding the sources and mitigation potential of nitrous oxide in agriculture

    NASA Astrophysics Data System (ADS)

    Horwath, W. R.; Zhu, X.; Doane, T. A.; Burger, M.

    2014-12-01

    More than half of the global warming potential of GHG emissions from agriculture is attributed to nitrous oxide (N2O).. Many factors control the production and release of N2O from soils. In addition to fertilizer N, soil N, moisture and carbon availability control N2O emissions. In addition, a previously overlooked factor, iron, was recently found to be the most significant factor influencing N2O production. Controlled by soil and management factors, N2O production is attributed to multiple pathways, including ammonia oxidation (AO), denitrification, and abiotic chemical reactions. Ammonia oxidation or nitrifier activity N2O production, is a well known pathway, but it significance to total N2O production is also highly debated and soil conditions influencing its production are poorly understood. Studies in a variety of crops in California strongly suggest that this pathway contributes substantially to N2O emissions. It is well established that denitrification primarily occurs under O2- limiting conditions, while N2O produced from AO is also influenced by soil O2 content, with maximum production occurring at low O2 levels (~0.5%). Since emission of N2O can arise from both AO and denitrification activities at low O2 concentrations, it is difficult to discern the importance of each pathway under various soil conditions and management. Furthermore, both the N form and concentration are determinants of nitrifier N2O production. The nitrifier denitrification pathway has been shown to dominate over nitrifier nitrification and nitrification coupled denitrification pathways. Irrigation, rainfall, and fertilization events stimulate microbial activity, including AO and denitrification that produces N2O and although limited, these events contribute to the majority of annual emissions. This uncertainty and complexity surrounding N2O production pathways has hampered the development of practices to reduce N2O emissions. As agricultural production intensifies in developing

  19. Methane and nitrous oxide emissions of China: Sources from agricultural systems and mitigation options

    SciTech Connect

    Lin Erda; Li Yue; Dong Hongmin; Zhou Wennong

    1994-12-31

    This paper reports the estimated results of methane and nitrous oxide emissions from China`s agricultural systems. The results show that the overall methane emissions from paddies and ruminants were 11.335 and 5.796 Tg/y, respectively in 1990. For mitigation options, based on some experiments, a number of options were recommended to reduce methane and nitrous oxide emissions. Several research priority areas were proposed to reduce the uncertainties in estimates they are: (1) improve measurement methods; (2) further identify controlling factors; and (3) develop simulation models.

  20. The organic agricultural waste as a basic source of biohydrogen production

    NASA Astrophysics Data System (ADS)

    Sriwuryandari, Lies; Priantoro, E. Agung; Sintawardani, Neni; Astuti, J. Tri; Nilawati, Dewi; Putri, A. Mauliva Hada; Mamat, Sentana, Suharwadji; Sembiring, T.

    2016-02-01

    Biohydrogen production research was carried out using raw materials of agricultural organic waste that was obtained from markets around the Bandung city. The organic part, which consisted of agricultural waste material, mainly fruit and vegetable waste, was crushed and milled using blender. The sludge that produced from milling process was then used as a substrate for mixed culture microorganism as a raw material to produce biohydrogen. As much as 1.2 kg.day-1 of sludge (4% of total solid) was fed into bioreactor that had a capacity of 30L. Experiment was done under anaerobic fermentation using bacteria mixture culture that maintained at pH in the range of 5.6-6.5 and temperature of 25-30oC on semi-continuous mode. Parameters of analysis include pH, temperature, total solid (TS), organic total solid (OTS), total gas production, and hydrogen gas production. The results showed that from 4% of substrate resulted 897.86 L of total gas, which contained 660.74 L (73.59%) of hydrogen gas. The rate of hydrogen production in this study was 11,063 mol.L-1.h-1.

  1. Carbonization on combustion and biodegradation of agricultural waste as a possible source of silica.

    PubMed

    Krishnamoorthy, Sarayu; Iyer, Nagesh R; Murthy, A Ramachandra

    2015-02-01

    Agricultural waste being the major solid waste in the environment, the study has explored and identified the presence of minerals especially silica in the agricultural waste like sugarcane bagasse ash and rice husk ash by carbonization on combustion at different thermal conditions and biodegradation. Presence of silica in the ash samples has been well characterized by the XRD, FT-IR, EDX, SEM and N2 sorption techniques. Presence of crystal phases of silica like quartz and cristoballite is well indexed by the X-ray diffraction peaks that appeared at 2θ = 27, 40 and 60 which is further confirmed by the peaks at 1100, 820 and 620 cm(-1) of FT-IR. The elemental composition of the silica in ash is determined by EDX analysis. The exothermic reaction and the mass loss observed in the TG/DTG at the transient temperature of 840-850 °C has confirmed the presence of the α-quartz. SEM micrograph has also supported the presence of silica and has revealed the various crystal shapes that were present in the sugarcane and husk ash. The study has clearly revealed that the silica content has increased with the increase in temperature and refinement of the combustion condition to a maximum of 18.7-52 % and on biodegradation to about 48.3-92.4 %. PMID:25413790

  2. [Contribution of Base Flow to Total Nitrogen Loading in Subtropical Agricultural Catchments].

    PubMed

    Ma, Qiu-mei; Li, Wei; Wang, Yi; Liu, Xin-liang; Li, Yong; Wu, Jin-shui

    2016-04-15

    With the fast development of economics and improvement of people's living standard, non-point source pollution of the agricultural catchments in subtropical China has become more and more severe, where water quality deterioration has become a main barrier for sustainable development and ecological restoration. The process of ecohydrology in catchment is greatly influenced by the process of base flow in channel. This study selected the Tuojia and Jianshan catchments located in Changsha County, Hunan Province, to quantify and compare the contribution of base flow to total nitrogen (TN) loading from January 2011 to December 2013, through field observation and model estimation. The results suggested that the Tuojia catchment with higher intensity of rice agriculture had the greater volume of base flow, higher average flow-weighted TN concentration in base flow, and greater monthly TN loading via base flow [15.2 mm · month⁻¹, 4.14 mg · L⁻¹ and 0.54 kg · (hm² · month)⁻¹, respectively] than those in the Jianshan catchment with lower intensity [11.4 mm · month⁻¹, 1.72 mg · L⁻¹ and 0.20 kg · (hm² · month)⁻¹, respectively]. The base flow contribution to TN loading showed an apparently seasonal pattern. During rice-growing seasons, the contributions of base flow to TN loading were 23.2% and 18.6% in the Tuojia and Jianshan catchments, respectively, lower than those in the fallow seasons (46.9% and 40.0% correspondingly. These results suggested that rice agriculture increased the contribution of base flow in the fallow season to TN loading. Therefore, to alleviate the suffering of non-point source pollution in the rice agriculture catchments, reasonable management measure of rice fields should be implemented to decrease contrihution of base flow to TN loading. PMID:27548958

  3. Magnitudes, nature, and effects of point and nonpoint discharges in the Chattahoochee River basin, Atlanta to West Point Dam, Georgia

    USGS Publications Warehouse

    Stamer, J.K.; Cherry, R.N.; Faye, R.E.; Kleckner, R.L.

    1978-01-01

    On an average annual basis and during the storm period of March 12-15, 1976, nonpoint-source loads for most constituents were larger than point-source loads at the Whitesburg station, located on the Chattahoochee River about 40 miles downstream from Atlanta, GA. Most of the nonpoint-source constituent loads in the Atlanta to Whitesburg reach were from urban areas. Average annual point-source discharges accounted for about 50 percent of the dissolved nitrogen, total nitrogen, and total phosphorus loads and about 70 percent of the dissolved phosphorus loads at Whitesburg. During a low-flow period, June 1-2, 1977, five municipal point-sources contributed 63 percent of the ultimate biochemical oxygen demand, and 97 percent of the ammonium nitrogen loads at the Franklin station, at the upstream end of West Point Lake. Dissolved-oxygen concentrations of 4.1 to 5.0 milligrams per liter occurred in a 22-mile reach of the river downstream from Atlanta due about equally to nitrogenous and carbonaceous oxygen demands. The heat load from two thermoelectric powerplants caused a decrease in dissolved-oxygen concentration of about 0.2 milligrams per liter. Phytoplankton concentrations in West Point Lake, about 70 miles downstream from Atlanta, could exceed three million cells per millimeter during extended low-flow periods in the summer with present point-source phosphorus loads. (Woodard-USGS)

  4. Fingerprinting Sources of Suspended Sediment in a Canadian Agricultural Watershed Using the MixSIAR Bayesian Unmixing Model

    NASA Astrophysics Data System (ADS)

    Smith, J. P.; Owens, P. N.; Gaspar, L.; Lobb, D. A.; Petticrew, E. L.

    2015-12-01

    An understanding of sediment redistribution processes and the main sediment sources within a watershed is needed to support watershed management strategies. The fingerprinting technique is increasingly being recognized as a method for establishing the source of the sediment transported within watersheds. However, the different behaviour of the various fingerprinting properties has been recognized as a major limitation of the technique, and the uncertainty associated with tracer selection needs to be addressed. There are also questions associated with which modelling approach (frequentist or Bayesian) is the best to unmix complex environmental mixtures, such as river sediment. This study aims to compare and evaluate the differences between fingerprinting predictions provided by a Bayesian unmixing model (MixSIAR) using different groups of tracer properties for use in sediment source identification. We used fallout radionuclides (e.g. 137Cs) and geochemical elements (e.g. As) as conventional fingerprinting properties, and colour parameters as emerging properties; both alone and in combination. These fingerprinting properties are being used (i.e. Koiter et al., 2013; Barthod et al., 2015) to determine the proportional contributions of fine sediment in the South Tobacco Creek Watershed, an agricultural watershed located in Manitoba, Canada. We show that the unmixing model using a combination of fallout radionuclides and geochemical tracers gave similar results to the model based on colour parameters. Furthermore, we show that a model that combines all tracers (i.e. radionuclide/geochemical and colour) gave similar results, showing that sediment sources change from predominantly topsoil in the upper reaches of the watershed to channel bank and bedrock outcrop material in the lower reaches. Barthod LRM et al. (2015). Selecting color-based tracers and classifying sediment sources in the assessment of sediment dynamics using sediment source fingerprinting. J Environ Qual

  5. Downstream mixing of sediment and tracers in agricultural catchments: Evidence of changing sediment sources and fluvial processes?

    NASA Astrophysics Data System (ADS)

    Ralph, Timothy; Wethered, Adam; Smith, Hugh; Heijnis, Henk

    2014-05-01

    Land clearance, soil tillage and grazing in agricultural catchments have liberated sediment and altered hydrological connectivity between hillslopes and channels, leading to increased sediment availability, mobilisation and delivery to rivers. The type and amount of sediment supplied to rivers is critical for fluvial geomorphology and aquatic ecosystem health. Contemporary sediment dynamics are routinely investigated using environmental radionuclides such as caesium-137 (Cs-137) and excess lead-210 (Pb-210ex), which can provide information regarding sediment source types and fluvial processes if sediment sources can be distinguished from one another and mixing models applied to representative samples. However, downstream transport, mixing and dilution of radionuclide-labelled sediment (especially from sources with low initial concentrations) can obliterate the tracer signal; sometimes before anything of geomorphological importance happens in the catchment. Can these findings be used as evidence of sediment source variations and fluvial processes when the limits of detection (of Cs-137 in particular) are being exceeded so rapidly downstream? Sediment sources and downstream sediment dynamics were investigated in Coolbaggie Creek, a major supplier of sediment to the Macquarie River in an agricultural catchment with temperate to semi-arid climate in Australia. Radionuclides were used to discriminate between the <63 micron fraction of sediment sources including forested topsoils (Cs-137 11.28 +/- 0.75 Bq/kg; Pb-210ex 181.87 +/- 20.00 Bq/kg), agricultural topsoils (Cs-137 3.21 +/- 0.26 Bq/kg; Pb-210ex 29.59 +/- 10.94 Bq/kg) and sub-soils from channel banks and gullies (Cs-137 1.45 +/- 0.47 Bq/kg; Pb-210ex 4.67 +/- 1.93 Bq/kg). Within the trunk stream, suspended sediment, organic matter and Cs-137 and Pb-210ex concentrations declined downstream. Results from a mixing model suggest that agricultural topsoils account for 95% of fine sediment entering the channel in the

  6. Towards a nutrient export risk matrix approach to managing agricultural pollution at source

    NASA Astrophysics Data System (ADS)

    Hewett, C. J. M.; Quinn, P. F.; Whitehead, P. G.; Heathwaite, A. L.; Flynn, N. J.

    A generic Nutrient Export Risk Matrix (NERM) approach is presented. This provides advice to farmers and policy makers on good practice for reducing nutrient loss and, hopefully, persuades them to implement such measures. Combined with a range of nutrient transport modelling tools and field experiments, NERMs can play an important role in reducing nutrient export from agricultural land. The Phosphorus Export Risk Matrix (PERM) is presented as an example NERM. The PERM integrates hydrological understanding of runoff with a number of agronomic and policy factors into a clear problem-solving framework. This allows farmers and policy makers to visualise strategies for reducing phosphorus loss through proactive land management. The risk of pollution is assessed by a series of informed questions relating to farming intensity and practice. This information is combined with the concept of runoff management to point towards simple, practical remedial strategies which do not compromise farmers’ ability to obtain sound economic returns from their crop and livestock.

  7. Integrating different knowledge sources and disciplines for practical applications in Forest and Agricultural Engineering

    NASA Astrophysics Data System (ADS)

    Guzmán, Gema; Castillo, Carlos; Taguas, Encarnación

    2013-04-01

    One of the aims of 'The Bologna Process' is to promote among the students the acquisition of practical, social and creative skills to face real-life situations and to solve the difficulties they might find during their professional life. It involves an important change in the educational system, from a traditional approach focused on teaching, towards a new one that encourages learning. Under this context, University teaching implies the design of activities addressed to the dissemination of "know-how" to solve different problems associated with two technical disciplines: Forest and Agricultural Engineering. This study presents a preliminary experience where a group of information and communication technologies (ICT) such as, audiovisual resources (videos, reports and photo gallery), virtual visits to blogs and interactive activities have been used to provide a comprehensive knowledge of the environmental and sociocultural components of the landscape in order to facilitate the decision-making process in the engineering project context . With these tools, the students must study and characterize all these aspects in order to justify the chosen solutions and the project design. This approach was followed in the analysis of the limiting factors of practical cases in projects about forestation, landscape restoration and hydrological planning. This communication shows how this methodology has been applied in Forest and Agricultural Engineering and the students' experience with these innovative tools. The use of ICTs involved a friendly framework that stimulated students' interest and made subjects more attractive, since it allowed to assess the complex relationships between landscape, history and economy. Furthermore, this type of activities promotes the interdisciplinary training and the acquisition of creative and autonomous skills which are not included in many cases into the main objectives of the subjects.

  8. Molecular markers for identifying municipal, domestic and agricultural sources of organic matter in natural waters.

    PubMed

    Harwood, John J

    2014-01-01

    Molecular markers can be used to determine the sources of organic pollution in water. This review summarizes progress made during the last two decades in identifying reliable molecular markers to distinguish pollution from sewage, animal production, and other sources. Two artificial sweeteners, sucralose and acesulfame-K, are sufficiently stable to be molecular markers and easily associated with domestic wastewater. Waste from different animal species may be distinguished by profiling fecal sterols and bile acids. Other markers which have been evaluated, including caffeine, detergent components, and compounds commonly leached from landfills are discussed. PMID:24200048

  9. Using Radioactive Fallout Cesium (137Cs) to Distinguish Sediment Sources in an Agricultural Watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Radioactive fallout Cesium (Cs-137) has been used for quantifying sources of accumulating sediment in water bodies and to determine the rates and pattern of soil erosion. The objectives of this research are to use Cs-137 as a tracer to determine patterns of soil erosion and deposition of eroding soi...

  10. Organic matter source and degradation as revealed by molecular biomarkers in agricultural soils of Yuanyang terrace

    NASA Astrophysics Data System (ADS)

    Li, Fangfang; Pan, Bo; Zhang, Di; Yang, Xiaolei; Li, Hao; Liao, Shaohua; Ghaffar, Abdul; Peng, Hongbo; Xing, Baoshan

    2015-06-01

    Three soils with different tillage activities were collected and compared for their organic matter sources and degradation. Two soils (TD and TP) with human activities showed more diverse of chemicals in both free lipids and CuO oxidation products than the one (NS) without human activities. Branched alkanoic acids only accounted for less than 5% of lipids, indicating limited microbial inputs in all three investigated soils. The degradation of lignin in NS and TD was relatively higher than TP, probably because of the chemical degradation, most likely UV light-involved photodegradation. Lignin parameters obtained from CuO oxidation products confirmed that woody gymnosperm tissue (such as pine trees) may be the main source for NS, while angiosperm tissues from vascular plant may be the predominant source for the lignins in TD and TP. Analysis of BPCAs illustrated that BC in NS may be mainly originated from soot or other fossil carbon sources, whereas BC in TD and TP may be produced during corn stalk and straw burning. BC was involved in mineral interactions for TD and TP. The dynamics of organic matter needs to be extensively examined for their nonideal interactions with contaminants.

  11. Organic matter source and degradation as revealed by molecular biomarkers in agricultural soils of Yuanyang terrace

    PubMed Central

    Li, Fangfang; Pan, Bo; Zhang, Di; Yang, Xiaolei; Li, Hao; Liao, Shaohua; Ghaffar, Abdul; Peng, Hongbo; Xing, Baoshan

    2015-01-01

    Three soils with different tillage activities were collected and compared for their organic matter sources and degradation. Two soils (TD and TP) with human activities showed more diverse of chemicals in both free lipids and CuO oxidation products than the one (NS) without human activities. Branched alkanoic acids only accounted for less than 5% of lipids, indicating limited microbial inputs in all three investigated soils. The degradation of lignin in NS and TD was relatively higher than TP, probably because of the chemical degradation, most likely UV light-involved photodegradation. Lignin parameters obtained from CuO oxidation products confirmed that woody gymnosperm tissue (such as pine trees) may be the main source for NS, while angiosperm tissues from vascular plant may be the predominant source for the lignins in TD and TP. Analysis of BPCAs illustrated that BC in NS may be mainly originated from soot or other fossil carbon sources, whereas BC in TD and TP may be produced during corn stalk and straw burning. BC was involved in mineral interactions for TD and TP. The dynamics of organic matter needs to be extensively examined for their nonideal interactions with contaminants. PMID:26046574

  12. Quantitative Assessment of Agricultural Runoff and Soil Erosion Using Mathematical Modeling: Applications in the Mediterranean Region

    NASA Astrophysics Data System (ADS)

    Arhonditsis, G.; Giourga, C.; Loumou, A.; Koulouri, M.

    2002-09-01

    Three mathematical models, the runoff curve number equation, the universal soil loss equation, and the mass response functions, were evaluated for predicting nonpoint source nutrient loading from agricultural watersheds of the Mediterranean region. These methodologies were applied to a catchment, the gulf of Gera Basin, that is a typical terrestrial ecosystem of the islands of the Aegean archipelago. The calibration of the model parameters was based on data from experimental plots from which edge-of-field losses of sediment, water runoff, and nutrients were measured. Special emphasis was given to the transport of dissolved and solid-phase nutrients from their sources in the farmers' fields to the outlet of the watershed in order to estimate respective attenuation rates. It was found that nonpoint nutrient loading due to surface losses was high during winter, the contribution being between 50% and 80% of the total annual nutrient losses from the terrestrial ecosystem. The good fit between simulated and experimental data supports the view that these modeling procedures should be considered as reliable and effective methodological tools in Mediterranean areas for evaluating potential control measures, such as management practices for soil and water conservation and changes in land uses, aimed at diminishing soil loss and nutrient delivery to surface waters. Furthermore, the modifications of the general mathematical formulations and the experimental values of the model parameters provided by the study can be used in further application of these methodologies in watersheds with similar characteristics.

  13. Evaluating the critical source area concept of phosphorus loss from soils to water-bodies in agricultural catchments.

    PubMed

    Shore, M; Jordan, P; Mellander, P-E; Kelly-Quinn, M; Wall, D P; Murphy, P N C; Melland, A R

    2014-08-15

    Using data collected from six basins located across two hydrologically contrasting agricultural catchments, this study investigated whether transport metrics alone provide better estimates of storm phosphorus (P) loss from basins than critical source area (CSA) metrics which combine source factors as well. Concentrations and loads of P in quickflow (QF) were measured at basin outlets during four storm events and were compared with dynamic (QF magnitude) and static (extent of highly-connected, poorly-drained soils) transport metrics and a CSA metric (extent of highly-connected, poorly-drained soils with excess plant-available P). Pairwise comparisons between basins with similar CSA risks but contrasting QF magnitudes showed that QF flow-weighted mean TRP (total molybdate-reactive P) concentrations and loads were frequently (at least 11 of 14 comparisons) more than 40% higher in basins with the highest QF magnitudes. Furthermore, static transport metrics reliably discerned relative QF magnitudes between these basins. However, particulate P (PP) concentrations were often (6 of 14 comparisons) higher in basins with the lowest QF magnitudes, most likely due to soil-management activities (e.g. ploughing), in these predominantly arable basins at these times. Pairwise comparisons between basins with contrasting CSA risks and similar QF magnitudes showed that TRP and PP concentrations and loads did not reflect trends in CSA risk or QF magnitude. Static transport metrics did not discern relative QF magnitudes between these basins. In basins with contrasting transport risks, storm TRP concentrations and loads were well differentiated by dynamic or static transport metrics alone, regardless of differences in soil P. In basins with similar transport risks, dynamic transport metrics and P source information additional to soil P may be required to predict relative storm TRP concentrations and loads. Regardless of differences in transport risk, information on land use and

  14. NON POINT SOURCE BASIN STATUS EVALUATION, LOWER SNAKE RIVER BASIN, IDAHO, JULY 1976

    EPA Science Inventory

    Region 10 has developed a nonpoint source assessment approach to assist EPA planners, land agencies, and state and local agencies in identifying probable nonpoint sources and determining their effect upon the fishable-swimmable aspect of Regional streams and rivers. Generally th...

  15. Agricultural waste as a source for the production of silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Vaibhav, Vineet; Vijayalakshmi, U.; Roopan, S. Mohana

    2015-03-01

    The major interest of the paper deals with the extraction of silica from four natural sources such as rice husk, bamboo leaves, sugarcane bagasse and groundnut shell. These waste materials in large quantities can create a serious environmental problem. Hence, there is a need to adopt proper strategy to reduce the waste. In the present investigation, all the waste materials are subjected to moisture removal in a hot plate and sintered at 900 °C for 7 h. The sintered powder was treated with 1 M NaOH to form sodium silicate and then with 6 M H2SO4 to precipitate silica. The prepared silica powders were characterized by FT-IR, XRD and SEM-EDAX analysis. The silica recovered from different sources was found to vary between 52% and 78%. Magnesium substituted silica was formed from the groundnut waste and further treatment is required to precipitate silica.

  16. Agricultural waste as a source for the production of silica nanoparticles.

    PubMed

    Vaibhav, Vineet; Vijayalakshmi, U; Roopan, S Mohana

    2015-03-15

    The major interest of the paper deals with the extraction of silica from four natural sources such as rice husk, bamboo leaves, sugarcane bagasse and groundnut shell. These waste materials in large quantities can create a serious environmental problem. Hence, there is a need to adopt proper strategy to reduce the waste. In the present investigation, all the waste materials are subjected to moisture removal in a hot plate and sintered at 900°C for 7 h. The sintered powder was treated with 1 M NaOH to form sodium silicate and then with 6M H2SO4 to precipitate silica. The prepared silica powders were characterized by FT-IR, XRD and SEM-EDAX analysis. The silica recovered from different sources was found to vary between 52% and 78%. Magnesium substituted silica was formed from the groundnut waste and further treatment is required to precipitate silica. PMID:25576950

  17. [Mechanism of stomatal regulation by root sourced signaling and its agricultural signficance].

    PubMed

    Guo, Anhong; Li, Zhaoxiang; Liu, Gengshan; Yang, Yuanyan; An, Shunqing

    2004-06-01

    Under soil drought condition, root sourced signal abcisic acid (ABA) plays an important role in the long distance signaling process, and can be a measurement of soil water availability. ABA is also an effective stomatal closing agent, and acts to reduce transpiration and canopy water loss. This paper briefly introduced the physiological mechanism and theoretical model about the stomatal regulation by root sourced signaling, and indicated that the combination of this model with root water absorption model and stomatal conductance model could be more effective in depicting the response of plant to soil drying and atmospheric drought. In addition, some effective irrigation approaches, such as regulated deficit irrigation (RDI), partial root-zone drying (PRD) and controlled alternative irrigation (CAI) were profited from the mechanism of plant water use regulation by the root sourced signaling. These irrigation measures favored to reasonably distribute available soil water in root-zone. Root signaling system also played important role in regulating root growth and its development, retarding shoot growth to adjusting root shoot ratio, and optimizing assimilation allocation to favor to improve reproductive development. These processes hold substantial promise for enhancing crop water use efficiency. PMID:15362642

  18. Assessment of nitrate leakage and N2O emission from five environmental-friendly agricultural practices using fuzzy logic method and empirical formula.

    PubMed

    Qin, Lihuan; Wang, Yan; Wu, Yongfeng; Wang, Qian; Luo, Liangguo

    2015-06-01

    Agricultural nonpoint source pollution in China has been the major environmental problem, so environmental-friendly agricultural practices (EAPs) must be promoted to improve environmental quality. However, the most suitable practices for each agricultural region must first be identified. Thus, in the presented study a fuzzy-logic method and a revised empirical formula were used to assess nitrate leakage and N2O emissions, respectively, and to compare five EAPs in Xinxiang, a major grain-producing county in Henan Province, China. The required information was collected in face-to-face interviews with 10 extension service experts from the county, using a questionnaire to explore their opinions of the EAPs currently adopted by smallholder farmers, as well as the amounts, frequencies, varieties and proportions of nitrogen fertilizers applied annually. The results indicate that reduced tillage, soil testing and fertilizer recommendations would be the most appropriate practices to initially promote on a large scale in Xinxiang. PMID:26003184

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Targeting allergenic fungi in agricultural environments aids the identification of major sources and potential risks for human health.

    PubMed

    Weikl, F; Radl, V; Munch, J C; Pritsch, K

    2015-10-01

    Fungi are, after pollen, the second most important producers of outdoor airborne allergens. To identify sources of airborne fungal allergens, a workflow for qPCR quantification from environmental samples was developed, thoroughly tested, and finally applied. We concentrated on determining the levels of allergenic fungi belonging to Alternaria, Cladosporium, Fusarium, and Trichoderma in plant and soil samples from agricultural fields in which cereals were grown. Our aims were to identify the major sources of allergenic fungi and factors potentially influencing their occurrence. Plant materials were the main source of the tested fungi at and after harvest. Amounts of A. alternata and C. cladosporioides varied significantly in fields under different management conditions, but absolute levels were very high in all cases. This finding suggests that high numbers of allergenic fungi may be an inevitable side effect of farming in several crops. Applied in large-scale studies, the concept described here may help to explain the high number of sensitization to airborne fungal allergens. PMID:26022406

  1. 78 FR 69664 - Proposed Information Collection Request; Comment Request; Approval of State Coastal Nonpoint...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-20

    ... Pollution Control Programs AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: The... State Coastal Nonpoint Pollution Control Programs (CZARA Section 6217)'' (EPA ICR No. 1569.08, OMB... and submitted to EPA and NOAA Coastal Nonpoint Pollution Programs. Another State (Illinois)...

  2. Assessment of groundwater vulnerability to nitrates from agricultural sources using a GIS-compatible logic multicriteria model.

    PubMed

    Rebolledo, Boris; Gil, Antonia; Flotats, Xavier; Sánchez, José Ángel

    2016-04-15

    In the present study an overlay method to assess groundwater vulnerability is proposed. This new method based on multicriteria decision analysis (MCDA) was developed and validated using an appropriate case study in Aragon area (NE Spain). The Vulnerability Index to Nitrates from Agricultural Sources (VINAS) incorporates a novel Logic Scoring of Preferences (LSP) approach, and it has been developed using public geographic information from the European Union. VINAS-LSP identifies areas with five categories of vulnerability, taking into account the hydrogeological and environmental characteristics of the territory as a whole. The resulting LSP map is a regional screening tool that can provide guidance on the potential risk of nitrate pollution, as well as highlight areas where specific research and farming planning policies are required. PMID:26874616

  3. From deposition to erosion: Spatial and temporal variability of sediment sources, storage, and transport in a small agricultural watershed

    NASA Astrophysics Data System (ADS)

    Florsheim, J. L.; Pellerin, B. A.; Oh, N. H.; Ohara, N.; Bachand, P. A. M.; Bachand, S. M.; Bergamaschi, B. A.; Hernes, P. J.; Kavvas, M. L.

    2011-09-01

    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/km 2/year during 2006 and 5,950 kg/km 2/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

  4. From deposition to erosion: spatial and temporal variability of sediment sources, storage, and transport in a small agricultural watershed

    USGS Publications Warehouse

    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

  5. Point-source effects on N and P uptake in a forested and an agricultural Mediterranean streams.

    PubMed

    Merseburger, Gora; Martí, Eugènia; Sabater, Francesc; Ortiz, Jesús D

    2011-02-01

    We examined the effect of point-source inputs from wastewater treatment plants (WWTP) on in-stream uptake of ammonium, nitrate and phosphate and compared it between two streams draining catchments with contrasting land use. The selected streams were La Tordera and Gurri (NE Spain), draining a forest- and an agriculture-dominated catchment, respectively. In each stream, we compared nutrient uptake metrics, estimated from nutrient additions, between two reaches located upstream and downstream of a WWTP input. Measurements were done on 8-9 dates during 2002-2003. In La Tordera, the point-source increased concentrations of all studied nutrients; whereas in Gurri, this effect was less evident. Point-source effects on nutrient uptake differed between the two streams, and among solutes. In La Tordera, uptake lengths (S(w)) of ammonium and phosphate averaged hundreds of meters above the point-source, and increased (i.e., decreased uptake efficiency) 4 and 5 times, respectively, below the point-source. S(w) of nitrate was ≥2km regardless of reach location. In Gurri, S(w) of all studied nutrients was within the km range in the two reaches. In this stream, diffuse nutrient inputs from adjacent fields may overwhelm the local effect of the point-source input. Uptake velocities (v(f)) of the studied nutrients ranged between 10EXP(-6) and 10EXP(-4)m/s in the two streams, and were similar between the two reaches in each stream. However, phosphate v(f) decreased under increasing concentrations following a power function. This trend remained significant when combining our results with those compiled from literature, suggesting the efficiency loss response may be a general trend for phosphate across streams. The relative increases in uptake rates (U) below the point-source were proportional to the relative point-source contribution to downstream nutrient loads, especially for ammonium and nitrate. However, the increases in U were not enough to compensate for the increases in

  6. 7 CFR 634.5 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... performance of RCWP activities. (e) Agricultural nonpoint source pollution. Pollution originating from... RCWP application that reduces or prevents agricultural nonpoint source pollution to improve water... the identified critical area or source of the pollution problem in the project area, are...

  7. 7 CFR 634.5 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... performance of RCWP activities. (e) Agricultural nonpoint source pollution. Pollution originating from... RCWP application that reduces or prevents agricultural nonpoint source pollution to improve water... the identified critical area or source of the pollution problem in the project area, are...

  8. 7 CFR 634.5 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... performance of RCWP activities. (e) Agricultural nonpoint source pollution. Pollution originating from... RCWP application that reduces or prevents agricultural nonpoint source pollution to improve water... the identified critical area or source of the pollution problem in the project area, are...

  9. Nitrate sinks and sources as controls of spatio-temporal water quality dynamics in an agricultural headwater catchment

    NASA Astrophysics Data System (ADS)

    Schuetz, Tobias; Gascuel-Odoux, Chantal; Durand, Patrick; Weiler, Markus

    2016-02-01

    Several controls are known to affect water quality of stream networks during flow recession periods, such as solute leaching processes, surface water-groundwater interactions as well as biogeochemical in-stream turnover processes. Throughout the stream network, combinations of specific water and solute export rates and local in-stream conditions overlay the biogeochemical signals from upstream sections. Therefore, upstream sections can be considered functional units which could be distinguished and ordered regarding their relative contribution to nutrient dynamics at the catchment outlet. Based on snapshot sampling of flow and nitrate concentrations along the stream in an agricultural headwater during the summer flow recession period, we determined spatial and temporal patterns of water quality for the whole stream. A data-driven, in-stream-mixing-and-removal model was developed and applied for analysing the spatio-temporal in-stream retention processes and their effect on the spatio-temporal fluxes of nitrate from subcatchments. Thereby, we have been able to distinguish quantitatively between nitrate sinks, sources per stream reaches, and subcatchments, and thus we could disentangle the overlay of nitrate sink and source signals. For nitrate sources, we determined their permanent and temporal impact on stream water quality and for nitrate sinks, we found increasing nitrate removal efficiencies from upstream to downstream. Our results highlight the importance of distinct nitrate source locations within the watershed for in-stream concentrations and in-stream removal processes, respectively. Thus, our findings contribute to the development of a more dynamic perception of water quality in streams and rivers concerning ecological and sustainable water resource management.

  10. Modelling phosphorus inputs from agricultural sources and urban areas in river basins

    NASA Astrophysics Data System (ADS)

    Tetzlaff, Björn; Vereecken, Harry; Kunkel, Ralf; Wendland, Frank

    2009-03-01

    An area-differentiated model approach (MEPhos) for the quantification of mean annual P-inputs from point and diffuse sources is presented. The following pathways are considered: artificial drainage, wash-off, groundwater outflow, soil erosion, rainwater sewers, combined sewer overflows, municipal waste water treatment plants and industrial effluents. Two retention functions for rivers and reservoirs are included in order to model P-sinks within a river basin. This allows a complete record of P-loads in heterogeneous meso- and macroscale river basins and enables validation of modeling results with water quality data on a load basis. The model is applied to the River Ruhr basin (4,485 km2) in Germany, which includes contrasting natural conditions, land use patterns as well as population and industry densities. Based on validated modelling results sub-areas of high P-loads are localized and management options for the reduction of P-inputs to surface waters are proposed taking into account the site conditions of the sub-areas relevant for high P-inputs into surface waters.

  11. Woodchip bioreactors for N-source reduction in a highly managed agricultural landscape

    NASA Astrophysics Data System (ADS)

    Kult, K.; Jones, C. S.

    2011-12-01

    Excess nutrification and the resulting hypoxia in the Gulf of Mexico are increasingly understood to originate in managed landscapes of the Upper Mississippi River basin. Nitrogen inputs to cropped fields are high in landscapes with soils containing high organic nitrogen content that, when mineralized, releases nitrogen in the soluble nitrate form. These in situ sources supply extensive subsurface drainage systems that rapidly transport nitrogen to streams and ultimately the Gulf. Aggressive in-field N management can reduce loading to streams, but will not reduce loads to sufficiently impact Gulf hypoxia. Edge of Field (EOF) treatment will be needed to reach water quality objectives. Denitrification bioreactors are one technology being studied for practical and economical EOF nitrate reduction. Bioreactors intercept the high-N tile-drain effluent with woodchip substrates that provide carbon and energy to support denitrification. Iowa Soybean Association (ISA) installed six bioreactors. Design of the ISA bioreactors has focused on the diameter of the field tile and the catchment area. Designs balance discharge with retention times. The bioreactors have been designed to have a 4-hour hydraulic retention time (HRT) capable of treating 20% of peak flow. Denitrification is assumed to follow zero-order kinetics given the high NO3 concentrations in the studied systems. Aerobic organisms must deplete DO sufficiently so anaerobic denitrifying organisms can compete. Insufficient HRT results in unsatisfactory NO3 reductions. Conditions favoring incomplete denitrification can lead to emission of the greenhouse gas N2O. Excessive retention times allow for complete denitrification enabling SO4-reducing bacteria to thrive. This produces undesirable results: conversion of SO4 to H2S, C-source depletion, production of toxic CH3Hg+, and methanogenesis. A flow control structure (FCS) allows for management of HRT by modifying the position of stop logs. Increased HRT reduces the amount

  12. Phosphorus Treated Coal Combustion Products (CCP-bottom ash) as an Agricultural Source of Phosphorus

    NASA Astrophysics Data System (ADS)

    Junfeng, Shen; Powell, M. A.; Hayden, D. B.

    Coal combustion products (CCP or "ash") have been seen to be beneficial for improving soil quality and increasing vegetative yields. Owing to their structure with more holes, they are also potential carriers of plant nutrients. The bottom ash from the Lambton Generating Station, Sarnia, Ontario, Canada was treated for 66 hours in 0.10 mol/L P solutions prepared from NaH 2PO 4, which resulted in the ash adsorbing 784 µg/g of phosphorus. The ash was mixed with quartz sand and/or non P-loaded ash from the same source to provide a set of growth media that contained 10%, 25%, 50%, 75%, and 100% of the recommended dose of P (50 µg/g) for maize. Biomass yields at 26, 34, and 46 days after planting were compared with control (non-doped ash) and fertilized with 0-20-0 fertilizer. In general, growth media containing between 25% and 100% of the recommended P dose performed as well or better than the fertilized trials. 46 days after planting, the shoot fresh weight for the 50%, 75%, and 100% doped media were 39.46%, 42.73%, and 46.13%, respectively, greater compared to fertilized trials. The shoot dry weight increased by 29.71%, 13.39%, and 28.87%, respectively. Also, root fresh and dry weight increased averagely by 16.62% and 14.03%. These results implied that coal ashes are a better carrier for P uptaking, and P-loaded ash can be a good additive for sand soil improvement.

  13. Phosphorus Recycling from an Unexplored Source by Polyphosphate Accumulating Microalgae and Cyanobacteria-A Step to Phosphorus Security in Agriculture.

    PubMed

    Mukherjee, Chandan; Chowdhury, Rajojit; Ray, Krishna

    2015-01-01

    Phosphorus (P), an essential element required for crop growth has no substitute. The global food security depends on phosphorus availability in soil for crop production. World phosphorus reserves are fast depleting and with an annual increase of 2.3% in phosphorus demand, the current reserves will be exhausted in coming 50-100 years. India and other Western countries are forced to import phosphorus fertilizers at high costs to meet their agricultural demands due to uneven distribution of phosphate rocks on earth. The present study from India, aims to draw attention to an unnoticed source of phosphorus being wasted as parboiled rice mill effluent and subsequent bio-recovery of the valuable element from this unconventional source. The research was conducted in West Bengal, India, a state with the highest number of parboiled rice mills where its effluent carries on an average ~40 mg/L of soluble phosphorus. Technology to recover and recycle this wastewater P in India in a simple, inexpensive mode is yet to be optimized. Our strategy to use microalgae, Chlorella sp. and cyanobacteria, Cyanobacterium sp., Lyngbya sp., and Anabaena sp. to sequester the excess phosphorus from the effluent as polyphosphate inclusions and its subsequent recycling as slow and moderate release phosphorus biofertilizers to aid plant growth, preventing phosphorus loss and pollution, is a contemporary venture to meet the need of the hour. These polyphosphate accumulating microorganisms play a dual role of remediation and recovery of phosphorus, preliminarily validated in laboratory scale. PMID:26733966

  14. Dioxins, furans, biphenyls, arsenic, thorium and uranium in natural and anthropogenic sources of phosphorus and calcium used in agriculture.

    PubMed

    Avelar, A C; Ferreira, W M; Pemberthy, D; Abad, E; Amaral, M A

    2016-05-01

    The aim of this study was to assess the presence of dioxins, furans and biphenyls, and the inorganic contaminants such as arsenic (As), thorium (Th) and uranium (U) in three main products used in Agriculture in Brazil: feed grade dicalcium phosphate, calcined bovine bone meal and calcitic limestone. The first two are anthropogenic sources of phosphorus and calcium, while calcitic limestone is a natural unprocessed mineral. Regarding to dioxin-like substances, all samples analyzed exhibited dioxins (PCDD) and furans (PCDF) and dioxin-like polychlorinated biphenyls (dl-PCBs) concentrations below limit of detection (LOD). In general, achieved is in accordance with regulation in Brazil where is established a maximum limit in limestone used in the citric pulp production (0.50pg WHO-TEQ g(-1)). In addition, reported data revealed very low levels for limestone in comparison with similar materials reported by European legislation. As result for toxic metals, achieved data were obtained using Instrumental Neutron Activation Analysis (INAA). On one hand, limestone sample exhibits the largest arsenic concentration. On another hand, dicalcium phosphate exhibited the largest uranium concentration, which represents a standard in animal nutrition. Therefore, it is phosphorus source in the animal feed industry can be a goal of concern in the feed field. PMID:26901743

  15. Phosphorus Recycling from an Unexplored Source by Polyphosphate Accumulating Microalgae and Cyanobacteria—A Step to Phosphorus Security in Agriculture

    PubMed Central

    Mukherjee, Chandan; Chowdhury, Rajojit; Ray, Krishna

    2015-01-01

    Phosphorus (P), an essential element required for crop growth has no substitute. The global food security depends on phosphorus availability in soil for crop production. World phosphorus reserves are fast depleting and with an annual increase of 2.3% in phosphorus demand, the current reserves will be exhausted in coming 50–100 years. India and other Western countries are forced to import phosphorus fertilizers at high costs to meet their agricultural demands due to uneven distribution of phosphate rocks on earth. The present study from India, aims to draw attention to an unnoticed source of phosphorus being wasted as parboiled rice mill effluent and subsequent bio-recovery of the valuable element from this unconventional source. The research was conducted in West Bengal, India, a state with the highest number of parboiled rice mills where its effluent carries on an average ~40 mg/L of soluble phosphorus. Technology to recover and recycle this wastewater P in India in a simple, inexpensive mode is yet to be optimized. Our strategy to use microalgae, Chlorella sp. and cyanobacteria, Cyanobacterium sp., Lyngbya sp., and Anabaena sp. to sequester the excess phosphorus from the effluent as polyphosphate inclusions and its subsequent recycling as slow and moderate release phosphorus biofertilizers to aid plant growth, preventing phosphorus loss and pollution, is a contemporary venture to meet the need of the hour. These polyphosphate accumulating microorganisms play a dual role of remediation and recovery of phosphorus, preliminarily validated in laboratory scale. PMID:26733966

  16. Investigating the Sources and Dynamics of Dissolved Organic Matter in an Agricultural Watershed in California (U.S.A.)

    NASA Astrophysics Data System (ADS)

    Dyda, R. Y.; Hernes, P. J.; Spencer, R. G.; Ingrum, T. D.; Pellerin, B. A.; Bergamaschi, B. A.

    2007-12-01

    Dissolved organic matter (DOM) is ubiquitous and plays critical roles in nutrient cycling, aquatic food webs and numerous other biogeochemical processes. Furthermore, various factors control the quality and quantity of DOM, including land use, soil composition, in situ production, microbial uptake and assimilation and hydrology. As a component of DOM, dissolved organic carbon (DOC) has been recently identified as a drinking water constituent of concern due to its propensity to form EPA-regulated carcinogenic compounds when disinfected for drinking water purposes. Therefore, understanding the sources, cycling and modification of DOC across various landscapes is of direct relevance to a wide range of studies. The Willow Slough watershed is located in the Central Valley of California (U.S.A.) and is characterized by both diverse geomorphology as well as land use. The watershed drains approximately 425 km2 and is bordered by Cache and Putah Creeks to the north and south. The study area in the watershed includes the eastern portion of the foothills of the inner Coast Range and the alluvial plain and encompasses diverse land uses, including orchards, viticulture, dairy, pasture and natural grasslands. The Willow Slough watershed represents a unique opportunity to examine DOC dynamics through multiple land uses and hydrologic flow paths that are common throughout California. Preliminary data show that DOC concentrations at the watershed mouth peak during winter storms and also increase gradually throughout the summer months during the agricultural irrigation season. The increasing DOC concentrations during the summer months may result from agricultural runoff and/or primary production in channel. In addition, initial results using the chromophoric DOM (CDOM) absorption coefficient and spectral slope parameters indicate seasonal differences in the composition of the DOM. Spectral slopes decreased during both the summer irrigation season and winter storms relative to winter

  17. TMDL Implementation in Agricultural Landscapes: A Communicative and Systemic Approach

    NASA Astrophysics Data System (ADS)

    Jordan, Nicholas R.; Slotterback, Carissa Schively; Cadieux, Kirsten Valentine; Mulla, David J.; Pitt, David G.; Olabisi, Laura Schmitt; Kim, Jin-Oh

    2011-07-01

    Increasingly, total maximum daily load (TMDL) limits are being defined for agricultural watersheds. Reductions in non-point source pollution are often needed to meet TMDL limits, and improvements in management of annual crops appear insufficient to achieve the necessary reductions. Increased adoption of perennial crops and other changes in agricultural land use also appear necessary, but face major barriers. We outline a novel strategy that aims to create new economic opportunities for land-owners and other stakeholders and thereby to attract their voluntary participation in land-use change needed to meet TMDLs. Our strategy has two key elements. First, focused efforts are needed to create new economic enterprises that capitalize on the productive potential of multifunctional agriculture (MFA). MFA seeks to produce a wide range of goods and ecosystem services by well-designed deployment of annual and perennial crops across agricultural landscapes and watersheds; new revenue from MFA may substantially finance land-use change needed to meet TMDLs. Second, efforts to capitalize on MFA should use a novel methodology, the Communicative/Systemic Approach (C/SA). C/SA uses an integrative GIS-based spatial modeling framework for systematically assessing tradeoffs and synergies in design and evaluation of multifunctional agricultural landscapes, closely linked to deliberation and design processes by which multiple stakeholders can collaboratively create appropriate and acceptable MFA landscape designs. We anticipate that application of C/SA will strongly accelerate TMDL implementation, by aligning the interests of multiple stakeholders whose active support is needed to change agricultural land use and thereby meet TMDL goals.

  18. TMDL implementation in agricultural landscapes: a communicative and systemic approach.

    PubMed

    Jordan, Nicholas R; Slotterback, Carissa Schively; Cadieux, Kirsten Valentine; Mulla, David J; Pitt, David G; Olabisi, Laura Schmitt; Kim, Jin-Oh

    2011-07-01

    Increasingly, total maximum daily load (TMDL) limits are being defined for agricultural watersheds. Reductions in non-point source pollution are often needed to meet TMDL limits, and improvements in management of annual crops appear insufficient to achieve the necessary reductions. Increased adoption of perennial crops and other changes in agricultural land use also appear necessary, but face major barriers. We outline a novel strategy that aims to create new economic opportunities for land-owners and other stakeholders and thereby to attract their voluntary participation in land-use change needed to meet TMDLs. Our strategy has two key elements. First, focused efforts are needed to create new economic enterprises that capitalize on the productive potential of multifunctional agriculture (MFA). MFA seeks to produce a wide range of goods and ecosystem services by well-designed deployment of annual and perennial crops across agricultural landscapes and watersheds; new revenue from MFA may substantially finance land-use change needed to meet TMDLs. Second, efforts to capitalize on MFA should use a novel methodology, the Communicative/Systemic Approach (C/SA). C/SA uses an integrative GIS-based spatial modeling framework for systematically assessing tradeoffs and synergies in design and evaluation of multifunctional agricultural landscapes, closely linked to deliberation and design processes by which multiple stakeholders can collaboratively create appropriate and acceptable MFA landscape designs. We anticipate that application of C/SA will strongly accelerate TMDL implementation, by aligning the interests of multiple stakeholders whose active support is needed to change agricultural land use and thereby meet TMDL goals. PMID:21547434

  19. Evaluation of land use and water quality in an agricultural watershed in the USA indicates multiple sources of bacterial impairment.

    PubMed

    Wittman, Jacob; Weckwerth, Andrew; Weiss, Chelsea; Heyer, Sharon; Seibert, Jacob; Kuennen, Ben; Ingels, Chad; Seigley, Lynette; Larsen, Kirk; Enos-Berlage, Jodi

    2013-12-01

    Pathogens are the number one cause of impairments of assessed rivers and streams in the USA and pose a significant human health hazard. The Dry Run Creek Watershed in Northeast Iowa has been designated as impaired by the State of Iowa because of high levels of Escherichia coli bacteria. To investigate the nature of this impairment, land use and stream bank assessments were coupled with comprehensive water quality monitoring. Physical, chemical, and biological parameters were measured at 13 different sites in the watershed, including pH, temperature, conductivity, dissolved oxygen, turbidity, total Kjeldahl nitrogen, ammonia-N, nitrate + nitrite-N, total phosphorus, and E. coli. In addition, benthic macroinvertebrate communities were analyzed at seven sites, and optical brightener tests were performed late in the season. Results identified segments of the watershed that were more prominent contributors of E. coli, and correlations were observed between levels of E. coli and several chemical parameters, including ammonia-N, total Kjeldahl nitrogen, and total phosphorus. Interestingly, distinct sites emerged as more prominent contributors of these elements during rain vs. non-rain events, suggesting different types of sources. Both the amount of rainfall and the time elapsed between the rain event and the sampling influenced E. coli levels during wet weather conditions. Nitrate + nitrite-N displayed a unique response to rain events compared with the other parameters, suggesting a different delivery route. Analyses of benthic macroinvertebrate communities were consistent with pollution trends. Collectively, these data suggest distinct agriculturally related E. coli contributions, as well as specific areas and practices for water quality improvement strategies. This study can serve as a resource for evaluating agricultural watersheds that are impaired for bacteria. PMID:23873513

  20. A lighting assembly based on red and blue light-emitting diodes as a lighting source for space agriculture

    NASA Astrophysics Data System (ADS)

    Avercheva, Olga; Berkovich, Yuliy A.; Smolyanina, Svetlana; Bassarskaya, Elizaveta; Zhigalova, Tatiana; Ptushenko, Vasiliy; Erokhin, Alexei

    Light-emitting diodes (LEDs) are a promising lighting source for space agriculture due to their high efficiency, longevity, safety, and other factors. Assemblies based on red and blue LEDs have been recommended in literature, although not all plants show sufficient productivity in such lighting conditions. Adding of green LEDs proposed in some works was aimed at psychological support for the crew, and not at the improvement of plant growth. We studied the growth and the state of the photosynthetic apparatus in Chinese cabbage (Brassica chinensis L.) plants grown under red (650 nm) and blue (470 nm) light-emitting diodes (LEDs). Plants grown under a high-pressure sodium lamp (HPS lamp) were used as a control. The plants were illuminated with two photosynthetic photon flux levels: nearly 400 µE and about 100 µE. Plants grown under LEDs with 400 µE level, as compared to control plants, showed lower fresh weight, edible biomass, growth rate, and sugar content. The difference in fresh weight and edible biomass was even more pronounced in plants grown with 100 µE level; the data indicate that the adaptability of the test plants to insufficient lighting decreased. Under LEDs, we observed the decreasing of root growth and the absence of transition to the flowering stage, which points to a change in the hormonal balance in plants grown in such lighting conditions. We also found differences in the functioning of the photosynthetic apparatus and its reaction to a low lighting level. We have concluded that a lighting assembly with red and blue LEDs only is insufficient for the plant growth and productivity, and can bring about alterations in their adaptive and regulatory mechanisms. Further studies are needed to optimize the lighting spectrum for space agriculture, taking into account the photosynthetic, phototropic and regulatory roles of light. Using white LEDs or adding far-red and green LEDs might be a promising approach.

  1. Optimization of integrated water quality management for agricultural efficiency and environmental conservation.

    PubMed

    Fleifle, Amr; Saavedra, Oliver; Yoshimura, Chihiro; Elzeir, Mohamed; Tawfik, Ahmed

    2014-01-01

    The scarcity of water resources in Egypt has necessitated the use of various types of lower quality water. Agricultural drainage water is considered a strategic reserve for meeting increasing freshwater demands. In this study, a novel model series was applied to a drainage basin in the Nile Delta to optimize integrated water quality management for agriculture and the aquatic environment. The proposed model series includes a waste load allocation model, an export coefficient model, a stream water quality model, and a genetic algorithm. This model series offers an optimized solution for determining the required removal levels of total suspended solids (TSS), the chemical oxygen demand (COD) at point and non-point pollution sources, and the source flows that require treatment to meet a given water quality target. The model series was applied during the summer and winter to the El-Qalaa basin in the western delta of the Nile River. Increased pollutant removal and treated fractions at point and non-point sources reduced violations of the TSS standards from 732.6 to 238.9 mg/L in summer and from 543.1 to 380.9 mg/L in winter. Likewise, violations of the COD standards decreased from 112.4 mg/L to 0 (no violations) in summer and from 91.7 mg/L to no violations in winter. Thus, this model is recommended as a decision support tool for determining a desirable waste load allocation solution from a trade-off curve considering costs and the degree of compliance with water quality standards. PMID:24671393

  2. Nitrate sinks and sources as controls of spatio-temporal water quality dynamics in an agricultural headwater catchment

    NASA Astrophysics Data System (ADS)

    Schuetz, T.; Gascuel-Odoux, C.; Durand, P.; Weiler, M.

    2015-08-01

    Several controls are known to affect water quality of stream networks during flow recession periods such as solute leaching processes, surface water - groundwater interactions as well as biogeochemical in-stream retention processes. Throughout the stream network combinations of specific water and solute export rates and local in-stream conditions overlay the biogeochemical signals from upstream sections. Therefore, upstream sections can be considered as functional units which could be distinguished and ordered regarding their relative contribution to nutrient dynamics at the catchment outlet. Based on synoptic sampling of flow and nitrate concentrations along the stream in an agricultural headwater during the summer flow recession period, we determined spatial and temporal patterns of water quality for the whole stream. A data-driven, in-stream-mixing-and-removal model was developed and applied for analyzing the spatio-temporal in-stream retention processes and their effect on the spatio-temporal fluxes of nitrates from sub-catchments. Thereby, we have been able to distinguish between nitrate sinks and sources per stream reaches and sub-catchments. For nitrate sources we have determined their permanent and temporally impact on stream water quality and for nitrate sinks we have found increasing nitrate removal efficiencies from up- to downstream. Our results highlight the importance of distinct nitrate source locations within the watershed for in-stream concentrations and in-stream removal processes, respectively. Thus, our findings contribute to the development of a more dynamic perception of water quality in streams and rivers concerning ecological and sustainable water resources management.

  3. Application of strontium isotope measurements to trace sediment sources in an upstream agricultural catchment (Loire River basin, France)

    NASA Astrophysics Data System (ADS)

    Le Gall, Marion; Evrard, Olivier; Thil, François; Foucher, Anthony; Salvador-Blanes, Sébastien; Cerdan, Olivier; Ayrault, Sophie

    2015-04-01

    Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. It accelerates the supply of sediment to the rivers and degrades water quality. To limit those impacts and optimize management programs in such areas, sources of sediment need to be identified and sediment transport to be controlled. Here, we determined the sources of suspended sediment in the Louroux (24 km², French Loire River basin), a small catchment representative of lowland cultivated environments of Northwestern Europe. In this catchment, channels have been reshaped and 220 tile drain outlets have been installed over the last several decades. As a result, soil erosion and sediment fluxes have increased drastically. The variation of 87Sr/86Sr ratios, driven by the weathering of rocks with different ages and chemical composition, may reflect the mixing of different sediment sources. Strontium isotopic ratios (87Sr/86Sr) were therefore determined in potential soil sources, suspended particulate matter (SPM) and a sediment core sampled in the Louroux Pond at the catchment outlet. Soil, SPM and core samples displayed significantly different isotopic signatures. 87Sr/86Sr ratios in soil samples varied from 0.712763 to 0.724631 ± 0.000017 (2σ, n=20). Highest values were observed in silicic parts of the catchment whereas the lower values were identified in a calcareous area close to the Louroux Pond. 87Sr/86Sr ratios in SPM (0.713660 to 0.725749 ± 0.000017, 2σ, n=20) plotted between the soil and sediment core (0.712255 to 0.716415 ± 0.000017, 2σ, n=12), suggesting the presence of particles originating from at least two different lithological sources, i.e. silicic rocks and carbonate material. Variations in 87Sr/86Sr ratios in the outlet core sample were used to reconstruct the sedimentary dynamics in the catchment during the last decades. These results will guide the future implementation of appropriate management practices aiming to reduce erosion in upstream

  4. Identifying Landscape Areas Prone to Generating Storm Runoff in Central New York Agricultural Fields

    NASA Astrophysics Data System (ADS)

    Hofmeister, K.; Walter, M. T.

    2015-12-01

    Nonpoint source (NPS) pollution continues to be a leading cause of surface water degradation, especially in agricultural areas. In humid regions where variable source area (VSA) hydrology dominates storm runoff, NPS pollution is generated where VSAs coincide with polluting activities. Mapping storm runoff risks could allow for more precise and informed targeting of NPS pollution mitigation practices in agricultural landscapes. Topographic wetness indices (TWI) provide good approximations of relative soil moisture patterns and relative storm runoff risks. Simulation models are typically used in conjunction with TWIs to quantify VSA behavior. In this study we use empirically derived relationships between TWI values, volumetric water content (VWC) and rainfall frequencies to develop runoff probability maps. Rainfall and soil VWC were measured across regionally representative agricultural areas in central New York over three years (2012-2015) to determine the volume of runoff generated from agricultural fields in the area. We assumed the threshold for storm runoff occurs when the combination of antecedent soil water and rainfall are sufficient to saturate the soil. We determined that approximately 50% of the storm runoff volume is generated from 10% of the land area during spring, summer, and autumn seasons, while the risk of storm runoff generation is higher in the spring and autumn seasons than in the summer for the same area of land.

  5. Anthropogenic and geogenic Cd, Hg, Pb and Se sources of contamination in a brackish aquifer below agricultural fields

    NASA Astrophysics Data System (ADS)

    Mastrocicco, Micòl; Colombani, Nicolò; Di Giuseppe, Dario; Faccini, Barbara; Ferretti, Giacomo; Coltorti, Massimo

    2015-04-01

    Groundwater quality is often threatened by industrial, agricultural and land use practices (anthropogenic input). In deltaic areas is however difficult to distinguish between geogenic and anthropogenic inorganic contaminants pollution, since these phenomena can influence each other and often display a seasonal cycling. The effect of geogenic groundwater ionic strength (>10 g/l) on the mobility of trace elements like Cd, Hg, Pb and Se was studied in combination with the anthropogenic sources of these elements (fertilizers) in a shallow aquifer. The site is located in the Po river plain (Northern Italy) in an agricultural field belonging to a reclaimed deltaic environment, near Codigoro town. It is 6 ha wide and is drained by a subsurface drainage system made of PVC tile drains with a slope of 3‰, which provides gravity drainage towards two ditches that in turn discharge in a main channel. The whole area has been intensively cultivated with cereal rotation since 1960, mainly using synthetic urea as nitrogen fertilizer at an average rate of 180 kg-N/ha/y and pig slurry at an average rate of 60 kg-N/ha/y. The sediments were analyzed for major and trace elements via XRF, while major ions in groundwater were analyzed via IC and trace elements via ICP-MS. Three monitoring wells, with an inner diameter of 2 cm and screened down to 4 m below ground level, were set up in the field and sampled every four month from 2012 to 2014. The use of intensive depth profiles with resolution of 0.5 m in three different locations, gave insights into groundwater and sediment matrix interactions. To characterize the anthropogenic inputs synthetic urea and pig slurry were analyzed for trace elements via ICP-MS. The synthetic urea is a weak source of Cd and Hg (~1 ppb), while Se and Pb are found below detection limits. The pig slurry is a much stronger source of Se (~19 ppb) and Pb (~23 ppb) and a weak source of Cd (~3 ppb) and Hg (~2 ppb). Although, the mass loading rate pig slurry is

  6. Sustainable Sourcing of Global Agricultural Raw Materials: Assessing Gaps in Key Impact and Vulnerability Issues and Indicators.

    PubMed

    Springer, Nathaniel P; Garbach, Kelly; Guillozet, Kathleen; Haden, Van R; Hedao, Prashant; Hollander, Allan D; Huber, Patrick R; Ingersoll, Christina; Langner, Megan; Lipari, Genevieve; Mohammadi, Yaser; Musker, Ruthie; Piatto, Marina; Riggle, Courtney; Schweisguth, Melissa; Sin, Emily; Snider, Sara; Vidic, Nataša; White, Aubrey; Brodt, Sonja; Quinn, James F; Tomich, Thomas P

    2015-01-01

    Understanding how to source agricultural raw materials sustainably is challenging in today's globalized food system given the variety of issues to be considered and the multitude of suggested indicators for representing these issues. Furthermore, stakeholders in the global food system both impact these issues and are themselves vulnerable to these issues, an important duality that is often implied but not explicitly described. The attention given to these issues and conceptual frameworks varies greatly--depending largely on the stakeholder perspective--as does the set of indicators developed to measure them. To better structure these complex relationships and assess any gaps, we collate a comprehensive list of sustainability issues and a database of sustainability indicators to represent them. To assure a breadth of inclusion, the issues are pulled from the following three perspectives: major global sustainability assessments, sustainability communications from global food companies, and conceptual frameworks of sustainable livelihoods from academic publications. These terms are integrated across perspectives using a common vocabulary, classified by their relevance to impacts and vulnerabilities, and categorized into groups by economic, environmental, physical, human, social, and political characteristics. These issues are then associated with over 2,000 sustainability indicators gathered from existing sources. A gap analysis is then performed to determine if particular issues and issue groups are over or underrepresented. This process results in 44 "integrated" issues--24 impact issues and 36 vulnerability issues--that are composed of 318 "component" issues. The gap analysis shows that although every integrated issue is mentioned at least 40% of the time across perspectives, no issue is mentioned more than 70% of the time. A few issues infrequently mentioned across perspectives also have relatively few indicators available to fully represent them. Issues in the

  7. Using SWAT, Bacteroidales microbial source tracking markers, and fecal indicator bacteria to predict waterborne pathogen occurrence in an agricultural watershed.

    PubMed

    Frey, Steven K; Topp, Edward; Edge, Thomas; Fall, Claudia; Gannon, Victor; Jokinen, Cassandra; Marti, Romain; Neumann, Norman; Ruecker, Norma; Wilkes, Graham; Lapen, David R

    2013-10-15

    Developing the capability to predict pathogens in surface water is important for reducing the risk that such organisms pose to human health. In this study, three primary data source scenarios (measured stream flow and water quality, modelled stream flow and water quality, and host-associated Bacteroidales) are investigated within a Classification and Regression Tree Analysis (CART) framework for classifying pathogen (Escherichia coli 0157:H7, Salmonella, Campylobacter, Cryptosporidium, and Giardia) presence and absence (P/A) for a 178 km(2) agricultural watershed. To provide modelled data, a Soil Water Assessment Tool (SWAT) model was developed to predict stream flow, total suspended solids (TSS), total N and total P, and fecal indicator bacteria loads; however, the model was only successful for flow and total N and total P simulations, and did not accurately simulate TSS and indicator bacteria transport. Also, the SWAT model was not sensitive to an observed reduction in the cattle population within the watershed that may have resulted in significant reduction in E. coli concentrations and Salmonella detections. Results show that when combined with air temperature and precipitation, SWAT modelled stream flow and total P concentrations were useful for classifying pathogen P/A using CART methodology. From a suite of host-associated Bacteroidales markers used as independent variables in CART analysis, the ruminant marker was found to be the best initial classifier of pathogen P/A. Of the measured sources of independent variables, air temperature, precipitation, stream flow, and total P were found to be the most important variables for classifying pathogen P/A. Results indicate a close relationship between cattle pollution and pathogen occurrence in this watershed, and an especially strong link between the cattle population and Salmonella detections. PMID:24079968

  8. Sustainable Sourcing of Global Agricultural Raw Materials: Assessing Gaps in Key Impact and Vulnerability Issues and Indicators

    PubMed Central

    Springer, Nathaniel P.; Garbach, Kelly; Guillozet, Kathleen; Haden, Van R.; Hedao, Prashant; Hollander, Allan D.; Huber, Patrick R.; Ingersoll, Christina; Langner, Megan; Lipari, Genevieve; Mohammadi, Yaser; Musker, Ruthie; Piatto, Marina; Riggle, Courtney; Schweisguth, Melissa; Sin, Emily; Snider, Sara; Vidic, Nataša; White, Aubrey; Brodt, Sonja; Quinn, James F.; Tomich, Thomas P.

    2015-01-01

    Understanding how to source agricultural raw materials sustainably is challenging in today’s globalized food system given the variety of issues to be considered and the multitude of suggested indicators for representing these issues. Furthermore, stakeholders in the global food system both impact these issues and are themselves vulnerable to these issues, an important duality that is often implied but not explicitly described. The attention given to these issues and conceptual frameworks varies greatly—depending largely on the stakeholder perspective—as does the set of indicators developed to measure them. To better structure these complex relationships and assess any gaps, we collate a comprehensive list of sustainability issues and a database of sustainability indicators to represent them. To assure a breadth of inclusion, the issues are pulled from the following three perspectives: major global sustainability assessments, sustainability communications from global food companies, and conceptual frameworks of sustainable livelihoods from academic publications. These terms are integrated across perspectives using a common vocabulary, classified by their relevance to impacts and vulnerabilities, and categorized into groups by economic, environmental, physical, human, social, and political characteristics. These issues are then associated with over 2,000 sustainability indicators gathered from existing sources. A gap analysis is then performed to determine if particular issues and issue groups are over or underrepresented. This process results in 44 “integrated” issues—24 impact issues and 36 vulnerability issues —that are composed of 318 “component” issues. The gap analysis shows that although every integrated issue is mentioned at least 40% of the time across perspectives, no issue is mentioned more than 70% of the time. A few issues infrequently mentioned across perspectives also have relatively few indicators available to fully represent them

  9. Application of particle size distributions to total particulate stack samples to estimate PM2.5 and PM10 emission factors for agricultural sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Particle size distributions (PSD) have long been used to more accurately estimate the PM10 fraction of total particulate matter (PM) stack samples taken from agricultural sources. These PSD analyses were typically conducted using a Coulter Counter with 50 micrometer aperture tube. With recent increa...

  10. Effectiveness of vegetated agricultural drainage ditches in mitigating insecticide loadings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies have shown that runoff and spray-drift are important sources of nonpoint-source insecticide pollution of surface waters. Owing to this, public concern over the presence of insecticides in surface and ground water has resulted in intensive scientific efforts to find economical, yet environmen...

  11. High-frequency monitoring reveals nutrient sources and transport processes in an agriculture-dominated lowland water system

    NASA Astrophysics Data System (ADS)

    van der Grift, Bas; Broers, Hans Peter; Berendrecht, Wilbert; Rozemeijer, Joachim; Osté, Leonard; Griffioen, Jasper

    2016-05-01

    Many agriculture-dominated lowland water systems worldwide suffer from eutrophication caused by high nutrient loads. Insight in the hydrochemical functioning of embanked polder catchments is highly relevant for improving the water quality in such areas or for reducing export loads to downstream water bodies. This paper introduces new insights in nutrient sources and transport processes in a polder in the Netherlands situated below sea level using high-frequency monitoring technology at the outlet, where the water is pumped into a higher situated lake, combined with a low-frequency water quality monitoring programme at six locations within the drainage area. Seasonal trends and short-scale temporal dynamics in concentrations indicated that the NO3 concentration at the pumping station originated from N loss from agricultural lands. The NO3 loads appear as losses via tube drains after intensive rainfall events during the winter months due to preferential flow through the cracked clay soil. Transfer function-noise modelling of hourly NO3 concentrations reveals that a large part of the dynamics in NO3 concentrations during the winter months can be related to rainfall. The total phosphorus (TP) concentration and turbidity almost doubled during operation of the pumping station, which points to resuspension of particulate P from channel bed sediments induced by changes in water flow due to pumping. Rainfall events that caused peaks in NO3 concentrations did not results in TP concentration peaks. The rainfall induced and NO3 enriched quick interflow, may also be enriched in TP but retention of TP due to sedimentation of particulate P then results in the absence of rainfall induced TP concentration peaks. Increased TP concentrations associated with run-off events is only observed during a rainfall event at the end of a freeze-thaw cycle. All these observations suggest that the P retention potential of polder water systems is primarily due to the artificial pumping regime

  12. High-frequency monitoring reveals nutrient sources and transport processes in an agriculture-dominated lowland water system

    NASA Astrophysics Data System (ADS)

    van der Grift, B.; Broers, H. P.; Berendrecht, W. L.; Rozemeijer, J. C.; Osté, L. A.; Griffioen, J.

    2015-08-01

    Many agriculture-dominated lowland water systems worldwide suffer from eutrophication caused by high nutrient loads. Insight in the hydrochemical functioning of embanked polder catchments is highly relevant for improving the water quality in such areas. This paper introduces new insights in nutrient sources and transport processes in a low elevated polder in the Netherlands using high-frequency monitoring technology at the outlet, where the water is pumped into a higher situated lake, combined with a low-frequency water quality monitoring program at six locations within the drainage area. Seasonal trends and short scale temporal dynamics in concentrations indicated that the NO3 concentration at the pumping station originated from N-loss from agricultural lands. The NO3 loads appear as losses with drain water discharge after intensive rainfall events during the winter months due to preferential flow through the cracked clay soil. Transfer function-noise modelling of hourly NO3 concentrations reveals that a large part of the dynamics in NO3 concentrations during the winter months can be related to rainfall. The total phosphorus (TP) concentration almost doubled during operation of the pumping station which points to resuspension of particulate P from channel bed sediments induced by changes in water flow due to pumping. Rainfall events that caused peaks in NO3 concentrations did not results in TP concentration peaks. The by rainfall induced and NO3 enriched quick interflow, may also be enriched in TP but this is then buffered in the water system due to sedimentation of particulate P. Increased TP concentrations associated with run-off events is only observed during a rainfall event at the end of a freeze-thaw cycle. All these observations suggest that the P retention potential of polder water systems is highly due to the artificial pumping regime that buffers high flows. As the TP concentration is affected by operation of the pumping station, timing of sampling

  13. Chemical characteristics and source apportionment of PM2.5 during the harvest season in eastern China's agricultural regions

    NASA Astrophysics Data System (ADS)

    Li, Jianfeng; Song, Yu; Mao, Yi; Mao, Zhichun; Wu, Yusheng; Li, Mengmeng; Huang, Xin; He, Qichao; Hu, Min

    2014-08-01

    To determine the contribution of the open burning of wheat straw residues to local PM2.5 during the harvest season of June 2013, PM2.5 was sampled in an agricultural region in eastern China. The sampling site was approximately 1 km from the nearest wheat field. Chemical compositions were analyzed, and source apportionment was undertaken using the positive matrix factorization model. The average PM2.5 concentration was 110.7 μg/m3, containing 36.4 μg/m3 organics, 7.3 μg/m3 EC, 6.0 μg/m3 potassium (K) and 4.9 μg/m3 chloride ion (Cl-). The sampling period was divided into three phases: the pre-local-burning phase (Phase 1), the local-burning phase (Phase 2) and the post-local-burning phase (Phase 3). In Phase 2, the concentrations of PM2.5 and the organics, EC, K and Cl- in PM2.5 were 163.6 μg/m3, 59.0 μg/m3, 12.2 μg/m3, 11.0 μg/m3 and 10.8 μg/m3, respectively, which were all remarkably higher than in both Phase 1 and Phase 3. Eight sources of PM2.5 were determined, including two types of wheat residue burning sources, which showed a significant difference in Cl- content. The atmospheric relative humidity (RH) and the aging process of PM2.5 might be the causes: only fresh particulate emissions from wheat residue burning could feature high-concentration Cl- under high RH conditions. In Phase 2, wheat residue burning contributed 51.3% of PM2.5, 75.8% of OC, 74.5% of EC, 90.1% of K and 104.1% of Cl-. These percentages were lower in Phases 1 and 3 than in Phase 2. Wheat residue burning caused such severe air pollution that it's necessary to prohibit the open burning of crop residues in order to protect public health and the environment.

  14. Impact of legacy phosphorus sources on diffuse phosphorus pollution from agriculture: lessons from the Chesapeake Bay watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Legacy phosphorus (P), the accumulation of P in soils and sediments due to past agricultural management activities, represents an emerging challenge to ongoing efforts to mitigate diffuse P pollution from agriculture. Nutrient management programs, already tasked with minimizing the effects of today...

  15. A Description and Source Listing of Professional Information in Agricultural Education, 1964-65, 1965-66.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Agricultural Education Div.

    This bibliography, containing professional information in agricultural education published in the school years 1964-65 and 1965-66 was prepared by the Professional Information Committee of the Agricultural Division of the American Vocational Association. Respectively they contain 141 and 170 listings with short annotations including availability…

  16. Descriptions and Source Listings of Professional Information in Agricultural Education, 1966-67, 1967-68, and 1968-69.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Professional Information Committee.

    These annotated bibliographies contain a total of 449 references of professional information in agricultural education published annually. References are organized under headings of: (1) Agricultural Mechanics, (2) Animal Science, (3) Conservation and Forestry, (4) Curriculum Development and Course of Study, (5) Farm Business Management and…

  17. Agricultural pollution control under Spanish and European environmental policies

    NASA Astrophysics Data System (ADS)

    MartíNez, Yolanda; Albiac, José

    2004-10-01

    Nonpoint pollution from agriculture is an important environmental policy issue in Spain and the European Union. Agricultural pollution in Spain is being addressed by the National Irrigation Plan and by the European Water Framework Directive. This article contributes to the ongoing policy decision process by analyzing nonpoint pollution control and presenting results on the efficiency of abatement measures. Results question the reliance of the Water Framework Directive on water pricing as a pollution instrument for reaching good status for all waters because higher water prices close to full recovery cost advocated by the directive appear to be inefficient as an emission control instrument. Another important result is that abatement measures based on input taxes and standards on nitrogen appear to be more suitable than the National Irrigation Plan subsidies designed to promote irrigation investments. The results also contribute with further evidence to the discussion on the appropriate instrument base for pollution control, proving that nonpoint pollution control instruments cannot be assessed accurately without a correct understanding of the key underlying biophysical processes. Nonpoint pollution is characterized by nonlinearities, dynamics, and spatial dependency, and neglect of the dynamic aspects may lead to serious consequences for the design of measures. Finally, a quantitative assessment has been performed to explore discriminating measures based on crop pollution potential on vulnerable soils. No significant welfare gains are found from discriminating control, although results are contingent upon the level of damage, and discrimination could be justified in areas with valuable ecosystems and severe pollution damages.

  18. MICROBIAL SOURCE TRACKING GUIDE DOCUMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A significant percentage of surface waters I the U.S. do not meet the designated use criteria as determined by high densities of fecal indicator bacteria as set forth by the Clean Water Act. Both point and non-point sources contribute to water pollution. In contrast to point sources such as sewage...

  19. Reducing pollution in agriculture land, agroforestry and Common Agrarian Policy

    NASA Astrophysics Data System (ADS)

    Rosa Mosquera Losada, Maria; Santiago-Freijanes, José Javier; Ferreiro-Domínguez, Nuria; Rois, Mercedes; Rigueiro-Rodríguez, Antonio

    2015-04-01

    Reducing non-point source pollution in Europe is a key activity for the European institutions and citizens. Ensuring high quality food supply while environment is sustainable managed is a highly relevant in the European agriculture. New CAP tries to promote sustainability with the greening measures in Pillar I (EU payments) and Pillar II (EU-Country cofinanced payments). The star component of the Pillar I is the greening. The greening includes three types of activities related to crop rotation, maintenance of permanent pasture and the promotion of Ecological Focus Areas (EFA). Greening practices are compulsory in arable lands when they are placed in regions with low proportion of forests and when the owner has large farms. Among the EFA, there are several options that include agroforestry practices like landscape features, buffer strips, agroforestry, strips of eligible hectares along forest edges, areas with short rotation coppice. These practices promote biodiversity and the inclusion of woody vegetation that is able to increase the uptake of the excess of nutrients like N or P. USA Agriculture Department has also recognize the importance of woody vegetation around the arable lands to reduce nutrient pollution and promote biodiversity.

  20. Identification of sources and behavior of agricultural contaminants in groundwater using nitorgen and sulfur isootope in Haean basin, Korea

    NASA Astrophysics Data System (ADS)

    Kaown, Dugin; Kim, Heejung; Mayer, Bernard; Hyun, Yunjung; Lee, Jin-Yong; Lee, Kang-Kun

    2013-04-01

    The Haean basin shows a bowl-shaped topographic feature and the drainage system shows a dendritic pattern. The study area is consisted of forests (58.0%), vegetable fields (27.6%), rice paddy fields (11.4%) and fruit fields (0.5%). Most of residents in the study area practice agriculture and paddy rice and vegetables (Chinese radish) are the typical crops grown. The concentration of nitrate in groundwater showed 0.8 ~ 67.3 mg/L in June, 2012 and 2.0 ~ 65.7 mg/L in September, 2012. Hydrogeochemical values and stable isotope ratios of dissolved nitrate and sulfate in groundwater were used to identify contamination sources and transformation processes in shallow groundwater. The δ15N-NO3- values in the study area ranged between +5.2 and +16.9‰ in June and between +4.4 and +13.0‰ in September. The sulfate concentration in groundwater samples obtained from the study area varied from 0.8 to 16.5 mg/L in June and 0 to 19.7 mg/L in September. δ34S-SO42- values ranged from +2.9 to +11.7‰ in June and +1.6 to +8.2‰ in September. The values of δ15N-NO3- and δ34S-SO42- in September were slightly decreased than those of values in June. The chemical composition of groundwater in vegetable and fruit fields showed slightly lower values of δ34S-SO42- and δ15N-NO3- indicated that a mixture of synthetic and organic fertilizers is responsible for groundwater contamination with agro-chemicals. Most groundwater from forests and paddy fields showed slightly higher values of δ15N-NO3- suggested that organic fertilizer is introduced into subsurface.

  1. Degradation State, Sources, and Reactivity of Dissolved Organic Matter from an Amino Acid Time Series in an Agricultural Watershed

    NASA Astrophysics Data System (ADS)

    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.

  2. Forests on drained agricultural peatland are potentially large sources of greenhouse gases - insights from a full rotation period simulation

    NASA Astrophysics Data System (ADS)

    He, Hongxing; Jansson, Per-Erik; Svensson, Magnus; Björklund, Jesper; Tarvainen, Lasse; Klemedtsson, Leif; Kasimir, Åsa

    2016-04-01

    The CoupModel was used to simulate a Norway Spruce forest on fertile drained peat over 60 years, from planting in 1951 until 2011, describing abiotic, biotic and greenhouse gas (GHG) emissions (CO2 and N2O). By calibrating the model against tree ring derived biomass data and measured 6 year abiotic data we obtained a "reference" model by which we were able to describe the GHG fluxes and controlling factors over the 60 years. The GHG fluxes are composed of two important quantities, the forest carbon (C) uptake, 405 g C m‑2 yr‑1 and the decomposition of peat soil, 396 g C m‑2 yr‑1. N2O emissions contribute to the GHG emissions by 0.5 g N m‑2 yr‑1, corresponding to 56.8 g C m‑2 yr‑1. The 60-year-old Spruce forest has an accumulated biomass of 164 Mg C ha‑1. However, over this period 208 Mg C ha‑1 GHG has been added to the atmosphere, which means a net addition of GHG emissions. The main losses are from the peat soil and, indirectly, from forest thinning products, which we assume have a short lifetime. Model sensitivity analysis by changing initial soil C, drainage depth and initial soil C/N ratio also confirms that forests on drained agricultural peatland are a GHG source. We conclude that after harvest at an age of 80 years, most of the stored biomass carbon is liable to be released, the system having captured C only temporarily and with a cost of disappeared peat, adding both CO2 and N2O to the atmosphere.

  3. Nitrogen Isotope Tracing of Eutrophication Sources on a Watershed Scale: Nitrogen and Oxygen Isotopes of Nitrate

    NASA Astrophysics Data System (ADS)

    Showers, W. J.; Genna, B.; Karr, J.

    2001-05-01

    Nitrate contamination of shallow aquifers and surface waters associated with agricultural activities has become a major concern in river basins, like the Neuse, where significant agricultural land use is coupled with growing numbers of intensive animal operations (ILO's). The development of effective management practices to preserve water quality, or remediation strategies for basins already polluted requires source identification. The stable isotopes of nitrogen and oxygen in nitrate has been used as tracers to evaluate nitrogen sources on small scales, such as agricultural fields, or small watersheds with one dominate land use. This discrimination is possible because of the large fractionation associated with the volatilization of ammonia from animal wastes. Using stable isotopes on larger scales to evaluate nutrient sources is complicated by multiple sources, overlapping point and non-point sources, and co-existing biogeochemical processes that alter nitrate concentrations. To evaluate the potential of stable isotopes to determine the character of nutrient fluxes on larger scales, the isotopic/discharge relationship was examined for a watershed with little agricultural activity, an urban watershed, a watershed with mixed urban and agricultural land use, a watershed dominated by swine ILO's, and a watershed dominated by poultry ILO's. The watershed with little agricultural activity and the poultry watershed have similar isotope/discharge relationships with isotopic values at natural background levels and no change in concentration or isotopic composition in different discharge states. The urban watershed is dominated by point source isotopic values at all flow levels, the mixed urban and agricultural watershed is dominated by point source values during low flow conditions, and fertilizer non-point source values during high flow conditions. In this watershed nutrient concentrations also increase during low flow conditions. The swine watershed is dominated by

  4. Total Nitrogen Sources of the Three Gorges Reservoir--A Spatio-Temporal Approach.

    PubMed

    Ren, Chunping; Wang, Lijing; Zheng, Binghui; Holbach, Andreas

    2015-01-01

    Understanding the spatial and temporal variation of nutrient concentrations, loads, and their distribution from upstream tributaries is important for the management of large lakes and reservoirs. The Three Gorges Dam was built on the Yangtze River in China, the world's third longest river, and impounded the famous Three Gorges Reservoir (TGR). In this study, we analyzed total nitrogen (TN) concentrations and inflow data from 2003 till 2010 for the main upstream tributaries of the TGR that contribute about 82% of the TGR's total inflow. We used time series analysis for seasonal decomposition of TN concentrations and used non-parametric statistical tests (Kruskal-Walli H, Mann-Whitney U) as well as base flow segmentation to analyze significant spatial and temporal patterns of TN pollution input into the TGR. Our results show that TN concentrations had significant spatial heterogeneity across the study area (Tuo River> Yangtze River> Wu River> Min River> Jialing River>Jinsha River). Furthermore, we derived apparent seasonal changes in three out of five upstream tributaries of the TGR rivers (Kruskal-Walli H ρ = 0.009, 0.030 and 0.029 for Tuo River, Jinsha River and Min River in sequence). TN pollution from non-point sources in the upstream tributaries accounted for 68.9% of the total TN input into the TGR. Non-point source pollution of TN revealed increasing trends for 4 out of five upstream tributaries of the TGR. Land use/cover and soil type were identified as the dominant driving factors for the spatial distribution of TN. Intensifying agriculture and increasing urbanization in the upstream catchments of the TGR were the main driving factors for non-point source pollution of TN increase from 2003 till 2010. Land use and land cover management as well as chemical fertilizer use restriction were needed to overcome the threats of increasing TN pollution. PMID:26510158

  5. Total Nitrogen Sources of the Three Gorges Reservoir — A Spatio-Temporal Approach

    PubMed Central

    Ren, Chunping; Wang, Lijing; Zheng, Binghui; Holbach, Andreas

    2015-01-01

    Understanding the spatial and temporal variation of nutrient concentrations, loads, and their distribution from upstream tributaries is important for the management of large lakes and reservoirs. The Three Gorges Dam was built on the Yangtze River in China, the world’s third longest river, and impounded the famous Three Gorges Reservoir (TGR). In this study, we analyzed total nitrogen (TN) concentrations and inflow data from 2003 till 2010 for the main upstream tributaries of the TGR that contribute about 82% of the TGR’s total inflow. We used time series analysis for seasonal decomposition of TN concentrations and used non-parametric statistical tests (Kruskal-Walli H, Mann-Whitney U) as well as base flow segmentation to analyze significant spatial and temporal patterns of TN pollution input into the TGR. Our results show that TN concentrations had significant spatial heterogeneity across the study area (Tuo River> Yangtze River> Wu River> Min River> Jialing River>Jinsha River). Furthermore, we derived apparent seasonal changes in three out of five upstream tributaries of the TGR rivers (Kruskal-Walli H ρ = 0.009, 0.030 and 0.029 for Tuo River, Jinsha River and Min River in sequence). TN pollution from non-point sources in the upstream tributaries accounted for 68.9% of the total TN input into the TGR. Non-point source pollution of TN revealed increasing trends for 4 out of five upstream tributaries of the TGR. Land use/cover and soil type were identified as the dominant driving factors for the spatial distribution of TN. Intensifying agriculture and increasing urbanization in the upstream catchments of the TGR were the main driving factors for non-point source pollution of TN increase from 2003 till 2010. Land use and land cover management as well as chemical fertilizer use restriction were needed to overcome the threats of increasing TN pollution. PMID:26510158

  6. Tropical forests were the primary sources of new agricultural land in the 1980s and 1990s

    PubMed Central

    Gibbs, H. K.; Ruesch, A. S.; Achard, F.; Clayton, M. K.; Holmgren, P.; Ramankutty, N.; Foley, J. A.

    2010-01-01

    Global demand for agricultural products such as food, feed, and fuel is now a major driver of cropland and pasture expansion across much of the developing world. Whether these new agricultural lands replace forests, degraded forests, or grasslands greatly influences the environmental consequences of expansion. Although the general pattern is known, there still is no definitive quantification of these land-cover changes. Here we analyze the rich, pan-tropical database of classified Landsat scenes created by the Food and Agricultural Organization of the United Nations to examine pathways of agricultural expansion across the major tropical forest regions in the 1980s and 1990s and use this information to highlight the future land conversions that probably will be needed to meet mounting demand for agricultural products. Across the tropics, we find that between 1980 and 2000 more than 55% of new agricultural land came at the expense of intact forests, and another 28% came from disturbed forests. This study underscores the potential consequences of unabated agricultural expansion for forest conservation and carbon emissions. PMID:20807750

  7. Assessing the Risk of Phosphorus Loss and Identifying Critical Source Areas in the Chaohu Lake Watershed, China

    NASA Astrophysics Data System (ADS)

    Zhou, Huiping; Gao, Chao

    2011-11-01

    Agricultural nonpoint phosphorus (P) pollution is a primary cause of eutrophication in many freshwater systems. Identifying areas that are at high risk for P loss in a watershed and concentrating management efforts on these smaller sections is a more effective method for limiting P loss than implementing general strategies over a broad area. A modified P index scheme was used to assess the risk of P loss and identify critical source areas in the Chaohu Lake watershed on a regional scale. In the new P ranking scheme, soil P sorption index (PSI) and degree of P saturation (DPS) were introduced as source factors to represent the inherent ability of P transport in the soil-water interface. Distance from P sources to Chaohu Lake was also considered as a transport factor to take into account P degradation from source to the final receiving water. The ranking scheme was modified to use available data on the regional scale. P index calculation results showed high spatial variation of P loss risk in the Chaohu Lake watershed. The highest risk areas focused on the downstream parts of the main rivers that discharge into Chaohu Lake. The induction of new components into the P index calculation makes it possible to identify critical source areas of nonpoint P loss on a regional scale, thus allowing decision makers to implement best management practices (BMPs) in such a manner as to minimize P loss to sensitive watercourses.

  8. Source identification of PCDD/Fs in agricultural soils near to a Chinese MSWI plant through isomer-specific data analysis.

    PubMed

    Xu, Meng-Xia; Yan, Jian-Hua; Lu, Sheng-Yong; Li, Xiao-Dong; Chen, Tong; Ni, Ming-Jiang; Dai, Hui-Fen; Cen, Ke-Fa

    2008-04-01

    Isomer-specific data were investigated in order to identify the sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in agricultural soils, including Fluvo-aquic and paddy soils, in the vicinity of a Chinese municipal solid waste incineration (MSWI) plant. Homologue and isomer profiles of PCDD/Fs in soils were compared with those of potential sources, including combustion sources, i.e., MSWI flue gas and fly ash; and the impurities in agrochemicals, such as the pentachlorophenol (PCP), sodium pentachlorophenate (PCP-Na) and 1,3,5-trichloro-2-(4-nitrophenoxy) benzene (CNP). The results showed that the PCDD/F isomer profiles of combustion sources and agricultural soils were very similar, especially for PCDFs, although their homologue profiles varied, indicating that all the isomers within each homologue behave identically in the air and soil. Moreover, factor analysis of the isomer compositions among 33 soil samples revealed that the contamination of PCDD/Fs in agricultural soils near the MSWI plant were primarily influenced by the combustion sources, followed by the PCP/PCP-Na and CNP sources. This implication is consistent with our previous findings based on chemometric analysis of homologue profiles of soil and flue gas samples, and identifies PCP/PCP-Na as an additional important source of PCDD/Fs in the local area. This makes the similarities and differences of isomer profiles between Fluvo-aquic and paddy soils more explainable. It is, therefore, advisable to use isomer-specific data for PCDD/F source identifications where possible. PMID:18279911

  9. Application of nitrogen and phosphorus criteria for streams in agricultural landscapes.

    PubMed

    Chambers, P A; Benoy, G A; Brua, R B; Culp, J M

    2011-01-01

    Efforts to control eutrophication of water resources in agriculturally dominated ecosystems have focused on managing on-farm activities to reduce nutrient loss; however, another management measure for improving water quality is adoption of environmental performance criteria (or 'outcome-based standards'). Here, we review approaches for setting environmental quality criteria for nutrients, summarize approaches developed in Canada for setting 'ideal' and 'achievable' nutrient criteria for streams in agricultural watersheds, and consider how such criteria could be applied. As part of a 'National Agri-Environmental Standards Initiative', the Government of Canada committed to the development of non-regulatory environmental performance standards that establish total P (TP) and total N (TN) concentrations to protect ecological condition of agricultural streams. Application of four approaches for defining ideal standards using only chemistry data resulted in values for TP and TN spanning a relatively narrow range of concentrations within a given ecoregion. Cross-calibration of these chemically derived standards with information on biological condition resulted in recommendations for TP and TN that would likely protect aquatic life from adverse effects of eutrophication. Non-point source water quality modelling was then conducted in a specific watershed to estimate achievable standards, i.e. chemical conditions that could be attained using currently available and recommended management practices. Our research showed that, taken together, short-term achievable standards and ultimate ideal standards could be used to set policy targets that should, if realized, lower N and P concentrations in Canadian agricultural streams and improve biotic condition. PMID:22156121

  10. Managing Artificially Drained Low-Gradient Agricultural Headwaters for Enhanced Ecosystem Functions

    PubMed Central

    Pierce, Samuel C.; Kröger, Robert; Pezeshki, Reza

    2012-01-01

    Large tracts of lowlands have been drained to expand extensive agriculture into areas that were historically categorized as wasteland. This expansion in agriculture necessarily coincided with changes in ecosystem structure, biodiversity, and nutrient cycling. These changes have impacted not only the landscapes in which they occurred, but also larger water bodies receiving runoff from drained land. New approaches must append current efforts toward land conservation and restoration, as the continuing impacts to receiving waters is an issue of major environmental concern. One of these approaches is agricultural drainage management. This article reviews how this approach differs from traditional conservation efforts, the specific practices of drainage management and the current state of knowledge on the ecology of drainage ditches. A bottom-up approach is utilized, examining the effects of stochastic hydrology and anthropogenic disturbance on primary production and diversity of primary producers, with special regard given to how management can affect establishment of macrophytes and how macrophytes in agricultural landscapes alter their environment in ways that can serve to mitigate non-point source pollution and promote biodiversity in receiving waters. PMID:24832519

  11. Identifying sources of dissolved organic carbon in agriculturally dominated rivers using radiocarbon age dating: Sacramento-San Joaquin River Basin, California

    USGS Publications Warehouse

    Sickman, James O.; DiGiorgio, Carol L.; Davisson, M. Lee; Lucero, Delores M.; Bergamaschi, Brian A.

    2010-01-01

    We used radiocarbon measurements of dissolved organic carbon (DOC) to resolve sources of riverine carbon within agriculturally dominated landscapes in California. During 2003 and 2004, average Δ14C for DOC was -254‰ in agricultural drains in the Sacramento-San Joaquin Delta, -218‰ in the San Joaquin River, -175‰ in the California State Water Project and -152‰ in the Sacramento River. The age of bulk DOC transiting the rivers of California's Central Valley is the oldest reported for large rivers and suggests wide-spread loss of soil organic matter caused by agriculture and urbanization. Using DAX 8 adsorbent, we isolated and measured 14C concentrations in hydrophobic acid fractions (HPOA); river samples showed evidence of bomb-pulse carbon with average Δ14C of 91 and 76‰ for the San Joaquin and Sacramento Rivers, respectively, with older HPOA, -204‰, observed in agricultural drains. An operationally defined non-HPOA fraction of DOC was observed in the San Joaquin River with seasonally computed Δ14C values of between -275 and -687‰; the source of this aged material was hypothesized to be physically protected organic-matter in high clay-content soils and agrochemicals (i.e., radiocarbon-dead material) applied to farmlands. Mixing models suggest that the Sacramento River contributes about 50% of the DOC load in the California State Water Project, and agricultural drains contribute approximately one-third of the load. In contrast to studies showing stabilization of soil carbon pools within one or two decades following land conversion, sustained loss of soil organic matter, occurring many decades after the initial agricultural-land conversion, was observed in California's Central Valley.

  12. Tracing organic and inorganic pollution sources of agricultural crops and water resources in Güzelhisar Basin of the Aegean Region - Turkey

    NASA Astrophysics Data System (ADS)

    Czarnecki, Sezin; Colak Esetlili, Bihter; Esetlili, Tolga; Tepecik, Mahmut; Anac, Dilek; Düring, Rolf-Alexander

    2014-05-01

    The study area Güzelhisar Basin is 6 km far from the city Aliaga, Aegean Region in Turkey which represents a rather industrialized area having five large iron and steel factories, but also areas of agriculture. Steel industry in Aliaga is causing metal pollution. Around Güzelhisar Basin and nearby, the dominant crop fields are cotton, maize, vegetables, olive trees and vineyards. Güzelhisar stream and dam water is used for irrigation of the agricultural land. Due to contamination from metal industry in Aliaga, organic farming is not allowed in this region. Industrial activities in the region present a threat on sustainable agriculture. The region is a multi-impacted area in terms of several pollutant sources affecting soil and water quality. The overall objective of the project is to trace back plant nutrients (N, P, K, Ca, Mg, Na, Fe, Mn, Zn, Cu, and B), hazardous substances (i. e. persistent organic pollutants), radionuclides (40K, 232Th, 226Ra/238U), and metal contents (As, Cd, Cr, Co, Cu, Hg, Mn, Ni, Pb, and Zn) by examining the soils, agricultural crops and natural plants from Güzelhisar Basin and water and sediments from Güzelhisar stream and dam. Spatial distribution of pollution will be evaluated by regionalization methods. For this, an advanced analytical methodology will be applied which provides an understanding of sources and occurrence of the respective substances of concern. An innovative multi-tracer approach comprising organic and inorganic marker substances, will identify and quantitatively assess sources and their impact on water pollution and the pollutant pathways in this agricultural crop production system.

  13. [Interception Effect of Ecological Ditch on Nitrogen Transport in Agricultural Runoff in Subtropical China].

    PubMed

    Wang, Di; Li, Hong-fang; Liu, Feng; Wang, Yi; Zhong, Yuan-chun; He, Yang; Xiao, Run-fin; Wu, Jin-shui

    2016-05-15

    Interception effects of an ecological ditch, used to control agricultural non-point source pollution in subtropical China, on nitrogen transport in surface runoff were studied by monthly measuring the runoff volume and concentrations of ammonium nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃⁻-N) and total nitrogen (TN) at the ditch inlet and outlet from 2013 to 2014. In addition, differences of NH₄⁺-N, NO₃⁻-N and TN removal were compared between 2013 and 2014. The results showed that the study ecological ditch worked effectively in N removal with average NH₄⁺-N, NO₃⁻-N and TN removal rates of 77.8%, 58.3%, and 48.7%; and their interception rates were 38.4, 59.6, and 171.1 kg · a⁻¹, respectively. The average proportion of NH₄⁺-N and NO₃⁻-N in TN was 47.5% at inlet, and 33.6% at outlet, which was significantly lower than that at inlet (P < 0.01). All hydrophytes in the ecological ditch were replaced by Myriophyllum aquaticum in 2014, which led to the increased average NO₃⁻-N and TN removal rates of 30.5% and 18.2%, respectively, Compared to in 2013. The vegetation of Myriophyllum aquaticum was beneficial to the improvement of N interception in ecological ditch. These findings clearly demonstrated that ecological ditch can substantially reduce N loss from surface runoff and be used as an important technique to prevent agricultural non-point N pollution. PMID:27506024

  14. Denitrification of agricultural drainage line water via immobilized denitrification sludge.

    PubMed

    Hunt, Patrick G; Matheny, Terry A; Ro, Kyoung S; Stone, Kenneth C; Vanotti, Matias B

    2008-07-15

    Nonpoint source nitrogen is recognized as a significant water pollutant worldwide. One of the major contributors is agricultural drainage line water. A potential method of reducing this nitrogen discharge to water bodies is the use of immobilized denitrifying sludge (IDS). Our objectives were to (1) produce an effective IDS, (2) determine the IDS reaction kinetics in laboratory column bioreactors, and (3) test a field bioreactor for nitrogen removal from agricultural drainage line water. We developed a mixed liquor suspended solid (MLSS) denitrifying sludge using inoculant from an overland flow treatment system. It had a specific denitrification rate of 11.4 mg NO(3)-N g(-1) MLSS h(-1). We used polyvinyl alcohol (PVA) to immobilize this sludge and form IDS pellets. When placed in a 3.8-L column bioreactor, the IDS had a maximum removal rate (K(MAX)) of 3.64 mg NO(3)-N g(-1) pellet d(-1). In a field test with drainage water containing 7.8 mg NO(3)-N L(-1), 50% nitrogen removal was obtained with a 1 hr hydraulic retention time. Expressed as a 1 m(3) cubically-shaped bioreactor, the nitrogen removal rate would be 94 g NO(3)-N m(-2)d(-1), which is dramatically higher than treatment wetlands or passive carbonaceous bioreactors. IDS bioreactors offer potential for reducing nitrogen discharge from agricultural drainage lines. More research is needed to develop the bioreactors for agricultural use and to devise effective strategies for their implementation with other emerging technologies for improved water quality on both watershed and basin scales. PMID:18569323

  15. Polybrominated diphenyl ethers in residential and agricultural soils from an electronic waste polluted region in South China: distribution, compositional profile, and sources.

    PubMed

    Zhang, Shaohui; Xu, Xijin; Wu, Yousheng; Ge, Jingjing; Li, Weiqiu; Huo, Xia

    2014-05-01

    A detailed investigation was conducted to understand the concentration, distribution, profile and possible source of polybrominated diphenyl ethers (PBDEs) in residential and agricultural soils from Guiyu, Shantou, China, one of the largest electronic waste (e-waste) recycling and dismantling areas in the world. Ten PBDEs were analyzed in 46 surface soil samples in terms of individual and total concentrations, together with soil organic matter concentrations. Much higher concentrations of the total PBDEs were predicted in the residential areas (more than 2000 ng g(-1)), exhibiting a clear urban source, while in the agricultural areas, concentrations were lower than 1500 ng g(-1). PBDE-209 was the most dominant congener among the study sites, indicating the prevalence of commercial deca-PBDE. However signature congeners from commercial octa-PBDE were also found. The total PBDE concentrations were significantly correlated with each individual PBDE. Principal component analysis indicated that PBDEs were mainly distributed in three groups according to the number of bromine atoms on the phenyl rings, and potential source. This study showed that the informal e-waste recycling has already introduced PBDEs into surrounding areas as pollutant which thus warrants an urgent investigation into the transport of PBDEs in the soil-plant system of agricultural areas. PMID:24374188

  16. Information for Agricultural Development.

    ERIC Educational Resources Information Center

    Kaungamno, E. E.

    This paper describes the major international agricultural information services, sources, and systems; outlines the existing information situation in Tanzania as it relates to problems of agricultural development; and reviews the improvements in information provision resources required to support the process of agricultural development in Tanzania.…

  17. Estimating the Regional Flux of Nitrate and Agricultural Herbicide Compounds from Groundwater to Headwater Streams of the Northern Atlantic Coastal Plain, USA

    NASA Astrophysics Data System (ADS)

    Ator, S.; Denver, J. M.

    2011-12-01

    Agriculture is common in the Northern Atlantic Coastal Plain (NACP, including New Jersey through North Carolina), and groundwater discharge provides nitrogen (primarily in the form of nitrate) and herbicide compounds from agricultural sources along with the majority of flow to NACP streams. Poor water quality has contributed to ecological degradation of tidal streams and estuaries along much of the adjacent mid-Atlantic coast. Although statistical models have provided estimates of total instream nutrient flux in the Coastal Plain, the regional flux of nitrogen and herbicides during base flow is less well understood. We estimated the regional flux of nitrate and selected commonly used herbicide compounds from groundwater to non-tidal headwater streams of the NACP on the basis of late-winter or spring base-flow samples from 174 such streams. Sampled streams were selected using an unequal-probability random approach, and flux estimates are based on resulting population estimates rather than empirical models, which are commonly used for such estimates. Base-flow flux in the estimated 8,834 NACP non-tidal headwater streams are an estimated 21,200 kilograms per day of nitrate (as N) and 5.83, 0.565, and 20.7 kilograms per day of alachlor, atrazine, and metolachlor (including selected degradates), respectively. Base-flow flux of alachlor and metolachlor is dominated by degradates; flux of parent compounds is less than 3 percent of the total flux of parent plus degradates. Base-flow flux of nitrate and herbicides as a percentage of applications generally varies predictably with regional variations in hydrogeology. Abundant nonpoint (primarily agricultural) sources and hydrogeologic conditions, for example, contribute to particularly large base-flow flux from the Delmarva Peninsula to Chesapeake Bay. In the Delmarva Peninsula part of the Chesapeake Watershed, more than 10 percent of total nonpoint nitrogen applications is transported through groundwater to stream base flow

  18. Wastewater Reuse for Agriculture: Development of a Regional Water Reuse Decision-Support Model (RWRM) for Cost-Effective Irrigation Sources.

    PubMed

    Tran, Quynh K; Schwabe, Kurt A; Jassby, David

    2016-09-01

    Water scarcity has become a critical problem in many semiarid and arid regions. The single largest water use in such regions is for crop irrigation, which typically relies on groundwater and surface water sources. With increasing stress on these traditional water sources, it is important to consider alternative irrigation sources for areas with limited freshwater resources. One potential irrigation water resource is treated wastewater for agricultural fields located near urban centers. In addition, treated wastewater can contribute an appreciable amount of necessary nutrients for plants. The suitability of reclaimed water for specific applications depends on water quality and usage requirements. The main factors that determine the suitability of recycled water for agricultural irrigation are salinity, heavy metals, and pathogens, which cause adverse effects on human, plants, and soils. In this paper, we develop a regional water reuse decision-support model (RWRM) using the general algebraic modeling system to analyze the cost-effectiveness of alternative treatment trains to generate irrigation water from reclaimed wastewater, with the irrigation water designed to meet crop requirements as well as California's wastewater reuse regulations (Title 22). Using a cost-minimization framework, least-cost solutions consisting of treatment processes and their intensities (blending ratios) are identified to produce alternative irrigation sources for citrus and turfgrass. Our analysis illustrates the benefits of employing an optimization framework and flexible treatment design to identify cost-effective blending opportunities that may produce high-quality irrigation water for a wide range of end uses. PMID:27499353

  19. Agriculture Education. Agriculture Structures.

    ERIC Educational Resources Information Center

    Stuttgart Public Schools, AR.

    This curriculum guide is designed for group instruction of secondary agricultural education students enrolled in one or two semester-long courses in agriculture structures. The guide presents units of study in the following areas: (1) shop safety, (2) identification and general use of hand tools, (3) power tools, (4) carpentry, (5) blueprint…

  20. Historical accumulation of N and P and sources of organic matter and N in sediment in an agricultural reservoir in Northern China.

    PubMed

    Ni, Zhaokui; Wang, Shengrui; Chu, Zhaosheng; Jin, Xiangcan

    2015-07-01

    Agriculture has significantly intensified in Northern China since the 1980s. This intensification has caused a series of simultaneous lake ecological environment problems in this area. However, little is known about the role of agricultural intensification in historical nutrient dynamics and lake eutrophication processes. The Yanghe reservoir, a typical artificial reservoir characterized by high-yield grain production in Northern China, has been suffering from serious eutrophication and water quality deterioration. This study evaluates the effect of agricultural intensification on nutrient retention and source in the sediments using (210)Pb and (137)Cs dating techniques combined with stable C and N isotopes (δ(13)C, δ(15)N) and total organic carbon/total nitrogen, as well as total nitrogen (TN), total phosphorus (TP), and P fractions. Results suggested that agricultural intensification was keys to the accumulation of nutrients and was a source of organic matter (OM) and N in sediment for the past three decades. N and P pollution started in the 1980s and worsened from the 1990s. Good water quality status and steady sedimentary environment with low nutrient content (mean concentrations of TN and TP were 815 and 387 mg kg(-1), respectively) were observed before the 1980s. Sediment OM was primarily derived from aquatic plants, whereas N was primarily derived from soil erosion and aquatic plants. However, water quality began to deteriorate while sediment nutrient content began to increase after the 1980s, with values of 1186 mg kg(-1) for TN and 434 mg kg(-1) for TP in 1989. Sediment OM was primarily derived from C3 (sweet potato) and aquatic plants, and the major sources of N were soil erosion, fertilizer, and sewage, which accompany the rapid development of agriculture in the watershed. Following the further growth of grain production and fertilizers, excessive external nutrient loading has resulted in dramatic water quality and ecosystem deterioration since 1990

  1. Water quality response to riparian restoration in an agricultural watershed in Vermont, USA.

    PubMed

    Meals, D W

    2001-01-01

    Achievement of management goals for Lake Champlain (Vermont/New York, USA and Quebec, Canada) will require reduction of agricultural phosphorus loads, the dominant nonpoint source in the Basin. Cost-effective phosphorus reduction strategies need reliable treatment techniques beyond basic cropland and waste management practices. The Lake Champlain Basin Agricultural Watersheds National Monitoring Program (NMP) Project evaluates the effectiveness of livestock exclusion, streambank protection, and riparian restoration practices in reducing concentrations and loads of nutrients, sediment, and bacteria in surface waters. Treatment and control watersheds in northwestern Vermont have been monitored since 1994 according to a paired-watershed design. Monitoring consists of continuous stream discharge recording, flow-proportional sampling for total P, total Kjeldahl N, and total suspended solids, grab sampling for indicator bacterial, and land use/agricultural monitoring. Strong statistical calibration between the control and treatment watersheds has been achieved. Installation of riparian fencing, protected stream crossings, and streambank bioengineering was completed in 1997. Early post-treatment data suggest significant reduction in P concentrations and loads and in bacteria counts in the treated watershed. Monitoring is scheduled to continue through 2000. PMID:11379130

  2. Indicators of the sources and distribution of nitrate in water from shallow domestic wells in agricultural areas of the New Jersey Coastal Plain

    USGS Publications Warehouse

    Vowinkel, Eric F.; Tapper, Robert J.

    1995-01-01

    Previously collected and new water-quality data from shallow wells (screened interval less than 30 meters below the land surface) in predominantly agricultural areas of the New Jersey Coastal Plain were used to determine the relation of nitrate concentrations in shallow ground water to various hydrogeologic and land-use factors in the study area. Information on land use, well construction, hydrogeology, and water quality were used to predict the conditions under which concentrations of nitrate as nitrogen in water from domestic wells in predominantly agricultural areas are most likely to be equal to or larger than the U.S. Environmental Protection Agency maximum contaminant level (MCL) of 10 milligrams per liter. Results of the analyses of water-quality samples collected during 1980-89 from 230 shallow wells in the outcrop areas of the Kirkwood-Cohansey and Potomac-Raritan-Magothy aquifer systems were used to evaluate the regional effects of land use on shallow-ground-water quality. Results of statistical analysis indicate that concentrations of nitrate in shallow ground water are significantly different (p= 0.001) in agricultural areas than in undeveloped areas in both aquifer systems. Concentrations of nitrate nitrogen exceeded the MCL in water from more than 33 percent of the 60 shallow wells in agricultural areas. Concentrations of hitrate in water from shallow wells in agricultural areas increased as the percentage of agricultural land within an 800-meter-radius buffer zone of the wellhead increased (r= 0.81). Concentrations ofhitrate in water from domestic wells in agricultural areas were similar (p= 0.23) to those concentrations in water from irrigation wells. These results indicate that most of the nitrate in water from domestic wells in agricultural areas results from agricultural practices rather than other sources, such as septic systems. Water-quality samples collected from 12 shallow domestic wells in agricultural areas screened in the outcrop areas of

  3. Hydrologic controls on the sources and dynamics of dissolved organic matter in an agricultural catchment in the Central Valley, California (U.S.A.)

    NASA Astrophysics Data System (ADS)

    Dyda, R. Y.; Hernes, P. J.; Spencer, R. G.; Pellerin, B. A.; Bergamaschi, B. A.

    2008-12-01

    The influence of agricultural practices on the dynamics of dissolved organic matter (DOM) cycling in river systems is poorly understood. We investigated molecular compositions of DOM at 14 sites in an agriculturally-impacted catchment (Willow Slough; 415 km2) under several different flow regimes over the course of two years in order to investigate the influence of sub-catchments on the biogeochemistry at the mouth of the catchment. The Willow Slough catchment area includes eastern foothills of the inner Coast Range to the alluvial plains and encompasses diverse land uses, including natural grasslands, orchards, viticulture and pasture, all draining toward the Sacramento River. Knowledge of the composition of DOM composition is crucial, as dissolved organic carbon (DOC) can form EPA-regulated carcinogenic compounds during the drinking water disinfection process and is therefore considered a drinking water constituent of concern. Willow Slough offers the opportunity to examine carbon source, cycling and transportation through multiple flowpaths and land uses that are common in Californian agricultural watersheds. As a constituent of DOM, lignin phenols provide information on the source, composition, quality and degradation state of DOM. Uniquely derived from vascular plants, lignin phenols can be used to distinguish between angiosperm and gymnosperm tissues and carbon-normalized yields can offer insight on the proportion of vascular plant-derived carbon versus in-situ production. Throughout the Willow Slough watershed, ratios of syringyl to vanillyl and cinnamyl to vanillyl lignin phenols show that the vascular plant component of DOM can be primarily attributed to non-woody angiosperm tissues. Lower lignin phenol concentrations and carbon-normalized yields were observed in the headwaters (0.1-0.6 mg/100mg OC and 2.6-33 μg/L) versus the mouth (0.7-2.0 mg/100mg OC and 25-72 μg/L), indicating that mid-catchment tributaries play important roles in determining the

  4. Setting priorities for research on pollution reduction functions of agricultural buffers.

    PubMed

    Dosskey, Michael G

    2002-11-01

    The success of buffer installation initiatives and programs to reduce nonpoint source pollution of streams on agricultural lands will depend the ability of local planners to locate and design buffers for specific circumstances with substantial and predictable results. Current predictive capabilities are inadequate, and major sources of uncertainty remain. An assessment of these uncertainties cautions that there is greater risk of overestimating buffer impact than underestimating it. Priorities for future research are proposed that will lead more quickly to major advances in predictive capabilities. Highest priority is given for work on the surface runoff filtration function, which is almost universally important to the amount of pollution reduction expected from buffer installation and for which there remain major sources of uncertainty for predicting level of impact. Foremost uncertainties surround the extent and consequences of runoff flow concentration and pollutant accumulation. Other buffer functions, including filtration of groundwater nitrate and stabilization of channel erosion sources of sediments, may be important in some regions. However, uncertainty surrounds our ability to identify and quantify the extent of site conditions where buffer installation can substantially reduce stream pollution in these ways. Deficiencies in predictive models reflect gaps in experimental information as well as technology to account for spatial heterogeneity of pollutant sources, pathways, and buffer capabilities across watersheds. Since completion of a comprehensive watershed-scale buffer model is probably far off, immediate needs call for simpler techniques to gage the probable impacts of buffer installation at local scales. PMID:12375085

  5. A Simple Runoff Model Based on Topographic Wetness Indices and Soil Moisture for Central New York Agricultural Fields

    NASA Astrophysics Data System (ADS)

    Hofmeister, K.; Georgakakos, C.; Walter, M. T.

    2014-12-01

    Nonpoint source (NPS) pollution continues to be a leading cause of surface water degradation, especially in agricultural areas. In humid regions where variable source area (VSA) hydrology dominates, such as the Northeastern US, topographic wetness indices (TWI) are good approximations of relative soil moisture patterns. Mapping areas of the landscape likely to generate saturation-excess runoff and carry NPS pollution to surface waters could allow for more efficient, targeted best management practices in agricultural fields. Given the relationship between saturation excess runoff and soil water storage, we used volumetric water content (VWC) measured in five agricultural fields in central New York over two years (2012-2014) to develop runoff probability maps based on a soil topographic index (STI). The relationship between VWC and STI was strongest during the fall season after leaf fall at all sites except one. We calculated the probability of runoff occurring based on soil moisture and precipitation distributions during the sampling period. The threshold for runoff occurs when the depth of soil water and rainfall reach saturation of the soil, and appears to be at the average porosity of the soil at all sites. Counter to our initial hypothesis of a higher probability of saturation excess runoff during the spring when conditions are wetter, some sites showed higher frequencies of runoff during the fall season.

  6. Characterization and source apportionment of water pollution in Jinjiang River, China.

    PubMed

    Chen, Haiyang; Teng, Yanguo; Yue, Weifeng; Song, Liuting

    2013-11-01

    Characterizing water quality and identifying potential pollution sources could greatly improve our knowledge about human impacts on the river ecosystem. In this study, fuzzy comprehensive assessment (FCA), pollution index (PI), principal component analysis (PCA), and absolute principal component score-multiple linear regression (APCS-MLR) were combined to obtain a deeper understanding of temporal-spatial characterization and sources of water pollution with a case study of the Jinjiang River, China. Measurement data were obtained with 17 water quality variables from 20 sampling sites in the December 2010 (withered water period) and June 2011 (high flow period). FCA and PI were used to comprehensively estimate the water quality variables and compare temporal-spatial variations, respectively. Rotated PCA and receptor model (APCS-MLR) revealed potential pollution sources and their corresponding contributions. Application results showed that comprehensive application of various multivariate methods were effective for water quality assessment and management. In the withered water period, most sampling sites were assessed as low or moderate pollution with characteristics pollutants of permanganate index and total nitrogen (TN), whereas 90% sites were classified as high pollution in the high flow period with higher TN and total phosphorus. Agricultural non-point sources, industrial wastewater discharge, and domestic sewage were identified as major pollution sources. Apportionment results revealed that most variables were complicatedly influenced by industrial wastewater discharge and agricultural activities in withered water period and primarily dominated by agricultural runoff in high flow period. PMID:23737126

  7. Quantifying the dominant sources of sediment in a drained lowland agricultural catchment: The application of a thorium-based particle size correction in sediment fingerprinting

    NASA Astrophysics Data System (ADS)

    Foucher, Anthony; Laceby, Patrick J.; Salvador-Blanes, Sébastien; Evrard, Olivier; Le Gall, Marion; Lefèvre, Irène; Cerdan, Olivier; Rajkumar, Vignesh; Desmet, Marc

    2015-12-01

    Soil erosion is one of the main factors influencing land degradation and water quality at the global scale. Identifying the main sediment sources is therefore essential for the implementation of appropriate soil erosion mitigation measures. Accordingly, caesium-137 (137Cs) concentrations were used to determine the relative contribution of surface and subsurface erosion sources in a lowland drained catchment in France. As 137Cs concentrations are often dependent on particle size, specific surface area (SSA) and novel thorium (Th) based particle size corrections were applied. Surface and subsurface samples were collected to characterize the radionuclide properties of potential sources. Sediment samples were collected during one hydrological year and a sediment core was sampled to represent sediment accumulated over a longer temporal period. Additionally, sediment from tile drains was sampled to determine the radionuclide properties of sediment exported from the drainage network. A distribution modelling approach was used to quantify the relative sediment contributions from surface and subsurface sources. The results highlight a substantial enrichment in fine particles and associated 137Cs concentrations between the sources and the sediment. The application of both correction factors reduced this difference, with the Th correction providing a more accurate comparison of source and sediment samples than the SSA correction. Modelling results clearly indicate the dominance of surface sources during the flood events and in the sediment core. Sediment exported from the drainage network was modelled to originate predominantly from surface sources. This study demonstrates the potential of Th to correct for 137Cs particle size enrichment. More importantly, this research indicates that drainage networks may significantly increase the connectivity of surface sources to stream networks. Managing sediment transferred through drainage networks may reduce the deleterious effects of

  8. Dynamics and sources of reduced sulfur, humic substances and dissolved or