Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: June 10, 1996
Publication Date: N/A
Interpretive Summary: Non-point source (NPS) pollutants (e.g., fertilizers, pesticides, salts, trace elements) in terrestrial systems refer to those contaminants in surface and subsurface soil and water which can not be directly traced to a point location and are generally low in concentration. However, the extent of the contamination by NPS pollutants, the resultant difficulties in their removal, and the associated chronic health effects are the features that make NPS pollutants the most significant worldwide environmental threat. As the world's population continues to grow, mankind is faced with the difficult task of meeting the world's food demand. This can only be accomplished with sustainable agriculture. The goal of sustainable agriculture is to optimize food production while maintaining economic stability, minimizing the utilization of finite natural resources, and minimizing impacts upon the environment. Yet, agriculture remains as the single greatest contributor of NPS pollutants in soil and water resources. Modeling NPS pollutants is a key component to achieving sustainable agriculture, but theinubiquitous nature poses a complex technical problem. The spatial nature of the NPS pollution problem necessitates the use of a geographic information system (GIS) to manipulate the large volumes of spatial data. This paper provides an overview of the components required to successfully model NPS pollutants with GIS and a review of recent applications of GIS to the modeling of NPS pollutants in soil.
Technical Abstract: In recent years, worldwide attention has shifted from point source to non-point source (NPS) pollutants, particularly with regard to the pollution of surface and subsurface sources of drinking water. This is due to the widespread occurrence and potential chronic health effects of NPS pollutants. The ubiquitous nature of NPS pollutants poses a complex technical problem. The areal extent of their contamination increases the complexity and sheer volume of data required for assessment far beyond that of typical point source pollutants. 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. This paper provides an overview of the components (i.e., spatial variability, scale dependency, parameter/data estimation and measurement, uncertainty analysis, etc.) required to successfully model NPS pollutants with GIS and a review of recent applications of GIS to the modeling of non-point source pollutants in the vadose zone with deterministic solute transport models. The compatibility, strengths, and weaknesses of coupling a GIS to deterministic one-dimensional transport models are discussed.