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Showing 1 to 20 of 108 for “"nonpoint source"”.
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Parameter uncertainty in nonpoint source pollution modeling
… inherently non-deterministic nature of inputs in nonpoint source (NPS) pollution modeling and the lack of information in many cases results in considerable uncertainty in model input parameters, and therefore, model outputs. Uncertainty in input parameters has important implications for model use …
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Applying Probabilistic Risk Assessment to Agricultural Nonpoint Source Pollution
… for the discharge of excessive nitrogen from nonpoint sources (NPSs) to a stream was performed for a small agricultural watershed in northern Virginia. Risk, by definition, is the product of the frequency of occurrence of an event and the consequences of that event. The purpose of this …
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Market and bargaining approaches to nonpoint source pollution abatement problems
… protection, with specific reference to nonpoint source pollution from agricultural land. The case when polluters contribute recursively rather than additively to environmental damages is investigated. While an optimal solution is theoretically possible, there exist opportunities for …
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Control of agricultural nonpoint source pollution in Kranji Catchment, Singapore
… Kranji Reservoir, in an effort to determine the source and degree of agricultural nonpoint source pollution in the area. Grab samples collected from eight sampling locations along the reach of the drainage channel under wet- and dry-weather conditions were analyzed for nitrogen, phosphorus, and …
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Watershed nonpoint source management system: a geographic information system approach
… distributed parameter, annual, watershed nonpoint source management system (WATNPS) was developed for land management planning. WATNPS simulates annual sediment, nitrogen (chemical and livestock organic), and phosphorus (chemical and livestock organic) yields from nonpoint sources. The …
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Development of a continuous, physically-based distributed parameter, nonpoint source model
ANSWERS, an event-oriented, distributed parameter nonpoint source pollution model for simulating runoff and sediment transport was modified to develop a continuous nonpoint source model to simulate runoff, erosion, transport of dissolved and sediment-bound nutrients, and nutrient transformations. …
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Pollutant Monitoring of Effluent Credit Trading Programs For Agricultural Nonpoint Source Control
… effluent credit trading system that allows point source discharges to purchase effluent reductions by financing agricultural nonpoint source best management practices. It describes the results of a national survey of existing trading programs that assessed how each program determines nonpoint …
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Effects of Spatial Information on Estimated Farm Nonpoint Source Pollution Control Costs
… expected that agriculture will be targeted as a source of P reductions. Spatially variable physical and socioeconomic characteristics of a watershed and its occupant farms affect both the decisions made by farmers and the transport of nutrients. Evidence suggests that spatially variable …
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Nonpoint source pollution during dry and wet weather flows in an urbanized watershed
… the quality of urban runoff, from various nonpoint sources during dry weather flows (DWF) and wet weather flows (WWF) in the Las Vegas Valley. Standard constituents in urban runoff were measured to assess the quality of urban runoff, to identify the possible sources of DWF (groundwater …
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Nonpoint source pollution modeling of an agricultural watershed within a geographic information system
… the many strides made in the past two decades, nonpoint source (NPS) pollution continues to be an important environment management and water quality management problem. For the most part, analysis of NPS pollution in watersheds has depended on the use of lumped mathematical models to identify …
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Application of a nonpoint source pollution model to a small watershed in Virginia
AGNPS, a nonpoint source pollution model, was selected to stimulate sediment yield and chemical loadings from Owl Run watershed. The model was validated to demonstrate its applicability to Virginia Piedmont conditions. The validation was carried out by comparing simulation results with measured …
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Modeling nonpoint-source uranium pollution in an irrigated stream-aquifer system: calibration and simulation
… (LARV) in southeastern Colorado has been a source of significant agricultural productivity for well over a century, primarily due to extensive irrigation practices. Mirroring trends seen in other semi-arid irrigated areas globally, however, irrigated agriculture in the LARV has resulted in …
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GIS for source water assessment and nonpoint source modeling in the Las Vegas Valley
… contamination and protection of drinking water sources in the Las Vegas Valley. A Geographic Information System (GIS) was used to identify source water protection zones and to estimate nonpoint source loads for the entire watershed; The extent of the source water protection zones is represented …
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Modeling phosphorus transport in surface runoff from agricultural watersheds for nonpoint source pollution assessment
Nonpoint source pollution from cropland has been identified as the primary source of nitrogen and sediment, and a significant source of phosphorus in the Chesapeake Bay. These pollutants, whether from point or nonpoint sources, have been found to be the primary cause of declining water quality in …
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The impact of nonpoint source pollution from mining wastes on water quality, Elko County, Nevada
A study was performed at a mine site in Elko County, Nevada to determine the effects on water quality resulting from waste rock at the site. Statistically significant (alpha less than or equal to 0.05) increases of several constituents, including sulfate (272 mg/L), calcium (46 mg/L), and magnesium …
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Aid to the gatekeepers : design principles for technical assistance under coastal nonpoint source watershed management
Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1993.
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Simulated effects of agricultural management systems on potential nonpoint source loading of nitrate and pesticides
… litter applications were increased, with both sources apparently supplying N in excess of crop uptake potential. A 3-way instead of a 2-way split commercial N application reduced nitrate leaching minimally. Though tillage-cropping practices did affect percolation volumes, this did not result in …
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A Comparative Study of Stream-Gaging Methods Employed in Nonpoint Source Pollution Studies in Small Streams
… has increased with the rising concern about nonpoint source (NPS) pollution. NPS pollution studies, such as TMDL development, often involve quantification of flow in small first and second order streams. This application of technology intended for use in larger streams presents special …
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The Economic Impact of Applying Hypothetical Nonpoint Source Pollution Controls to Hog and Beef Feeding in Illinois
Made available in DSpace on 2014-12-13T19:23:20Z (GMT). No. of bitstreams: 1 7709203.pdf: 8481545 bytes, checksum: d4b398e45ede9e7e579e9b466ee19f8a (MD5) Previous issue date: 1976
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