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United States Department of Agriculture

Agricultural Research Service


item Loague, Keith
item Corwin, Dennis

Submitted to: Encyclopedia of Hydrological Sciences
Publication Type: Popular Publication
Publication Acceptance Date: 8/1/2004
Publication Date: 12/1/2005
Citation: Loague, K., Corwin, D.L. 2005. Point and nonpoint source pollution. In: M.G. Anderson (ed.) Encyclopedia of Hydrological Sciences. John Wiley & Sons, Ltd. Chichester, UK. Chapter 94: 1427-1439.

Interpretive Summary: This is an article for the Encyclopedia of Hydrological Sciences, which provides a review of point and nonpoint source (NPS) pollution. The article covers a discussion of the differences between point and NPS pollution; a historical background both from regulatory and environmental awareness perspectives; current methodologies for assessment with particular attention to the modeling of NPS pollutants using advanced information technologies such as remote sensing, GIS, and uncertainty analysis; and the presentation of three case studies to serve as examples for the modeling of point and NPS pollutants. One case study of three manufactured gas plants is a local-scale legacy assessment of point source pollution, while the other two case studies are regional-scale NPS pollution assessments of groundwater vulnerability for California's Central Valley (DBCP) and the Canary Island of Tenerife.

Technical Abstract: 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 pollution from point and nonpoint sources. Among these global environmental problems, point and nonpoint source pollution represent a perfect example of a complex multidisciplinary problems that exists over multiple scales with tremendous spatial and temporal complexity. A point source of pollution discharges to the environment from an identifiable location, whereas a nonpoint source of pollution enters the environment from a widespread area. The ability to accurately assess present and future point and nonpoint source pollution impacts on ecosystems ranging from local to global scales provides a powerful tool for environmental stewardship and guiding future human activities.

Last Modified: 10/20/2017
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