Scale‐Dependency of Solute Transport Modeling/GIS Applications

Abstract

AbstractThe movement of water through the soil profile and the consequent displacement and transformation of chemicals dissolved in the water is a key concern in preventing water quality degradation, with its eventual impact on living systems, both human and otherwise. Predictions of the effect of a particular water and chemical management system at the soil surface will lead to more enlightened control of chemicals introduced into the environment as pesticides, fertilizers, or waste products. The use of geographic information systems (GIS) in concert with simulation modeling of soil leaching processes is becoming more widespread as a procedure applied to environmental chemical fate issues. The use of GIS has brought to the forefront the spatial scale of such databases as soil survey, elevation, climate and land use, and their use in the modeling process. An accompanying concern is the spatial scale at which any simulation model is assumed to be accurate, and the spatial scale at which both model input and field‐verification data should be generated. Such modeling presently consists of a number of approaches, some useful at several spatial scales, and others more limited by the assumptions inherent in their development. This paper discusses these issues, and presents two case studies as examples.