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United States Department of Agriculture

Agricultural Research Service

Title: Modeling Nonpoint Source Pollutants in the Vadose Zone with GIS

Authors
item Corwin, Dennis
item Vaughan, Peter - UCR, RIVERSIDE, CA
item Loague, K - STANFORD UNIV.,STANFORD

Submitted to: Journal of Environmental Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 31, 1996
Publication Date: N/A

Interpretive Summary: Nonpoint source (NPS) pollutants are pollutants that are found spread over large volumes of soil and include fertilizers, pesticides, salts, and trace elements. NPS pollutants are the single greatest threat to the degradation of surface and subsurfaces sources of drinking water because of erosion and leaching, respectively. In addition, NPS pollutants such as salinity adversely affect 30-50% of the land globally. Computer models of NPS pollutants are a tool used to assess and thereby combat future detrimental effects of NPS pollutants in soil and groundwater. Geographic information systems (GIS) have emerged as a useful tool in environmental modeling, particularly for NPS pollutants. GIS offers a means of handling the tremendous amount of information required by environmental models and a means of displaying simulated results in a map form. A review is presented concerning the modeling of NPS pollutants in soil with GIS. The proliferation of GIS-based NPS pollutant models holds promise, yet caution is needed to avoid misuse of a potentially valuable environmental assessment tool for decision makers.

Technical Abstract: Nonpoint source (NPS) pollutants are recognized as the single greatest threat to surface and subsurface sources of drinking water throughout the world. The vadose zone serves as the conduit through which NPS pollutants travel through surface soil to groundwater supplies. Because of increased dependency on groundwater supplies, the ability to model groundwater vulnerability to the leaching of NPS pollutants through the vadose zone has grown in significance. Furthermore, the buildup of NPS pollutants such as salinity and trace elements (e.g., boron, selenium, etc.) in agricultural soils has created a need for identifying soils susceptible to the degradative effects of NPS pollutants upon crop productivity. Geographic information systems (GIS) have emerged as a useful tool in environmental modeling, particularly for NPS pollutants. A review is presented concerning the modeling of NPS pollutants in the vadose zone with GIS. Emerging technologies such as GIS act as catalysts to provide innovative approaches to heretofore unsolvable problems. The proliferation of GIS-based NPS pollutant models holds promise, yet caution is needed to avoid misuse of a potentially valuable environmental assessment tool for decision makers.

Last Modified: 10/20/2014
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