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United States Department of Agriculture

Agricultural Research Service

Title: An Integrated Approach for Modeling Water Flow and Solute Transport in the Vadose Zone

Authors
item Binayak, P. - U.C. RIVERSIDE
item Van Genuchten, Martinus

Submitted to: Soil Science Society of America Special Publication Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: October 30, 1995
Publication Date: N/A

Interpretive Summary: Quantifying and modeling subsurface nonpoint-source pollution is being viewed as an important, yet often challenging problem in view of the overwhelming heterogeneity of the subsurface environment. More recently, the cutting-edge technology of geographical information systems (GIS) is increasingly being applied to surface and subsurface flow and transport modeling so as to alleviate some of these problems. In this paper we describe an integrated conceptual framework for predicting basin-scale solute loading rates through and from the vadose zone. The approach couples the ARC/INFO geographical information system with a deterministic variably-saturated flow/transport model (HYDRUS), an unsaturated soil hydraulic database (UNSODA), a digital database (STATSGO) in conjunction with pedotransfer functions (PTFs), and a geostatistical software package (GEOPACK). This integrated system with loosely-coupled independent technologies provides new possibilities for addressing nonpoint source surface and subsurface pollution problems.

Technical Abstract: As geographical information systems (GIS) are increasingly being applied to surface and subsurface flow and transport modeling issues, it becomes important to more clearly define potential advantages and achievable objectives for this technology. In this paper we describe an integrated conceptual framework for predicting basin-scale solute loading rates through and from the vadose zone. The approach couples the ARC/INFO geographical information system with a deterministic variably-saturated flow/transport model (HYDRUS), an unsaturated soil hydraulic property database (UNSODA), a digital soil database (STATSGO) in conjunction with pedotransfer functions (PTFs), and a geostatistical software package (GEOPACK). Suggestions are made on how best to integrate currently available or future knowledge of surface hydrology, vadose zone hydrology, and groundwater hydrology so as to more effectively address specific nonpoint source pollution problems. Whereas computations by the different components within the proposed integrated architecture can be made to run interactively, individual components will keep their identities at previous defined positions. The resulting integrated approach involving loosely-coupled independent technologies should provide new possibilities for addressing nonpoint source subsurface pollution problems.

Last Modified: 10/21/2014
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