WATERSHED-SCALE HYDROLOGIC AND NONPOINT-SOURCE POLLUTION MODELS: REVIEW OF MATHEMATICAL BASES

摘要: A clear understanding of a model is important for its appropriate use. In this article, eleven watershed scale hydrologic and nonpoint-source pollution models are reviewed: AGNPS, AnnAGNPS, ANSWERS, ANSWERS-Continuous, CASC2D, DWSM, HSPF, KINEROS, MIKE SHE, PRMS, SWAT. ANSWERS-Continuous, SWAT are continuous simulation useful analyzing long-term effects hydrological changes management practices, especially agricultural practices. KINEROS single rainfall event models useful severe actual or design single-event storms evaluating management practices, especially structural CASC2D, PRMS have both capabilities. Mathematical bases, the most critical elements these mathematical models, were identified compiled. In comprehensive summary compilation presented in tabular form. The flow-governing equations and their solution methods used each discussed. bases these models would be to determine problems, situations, conditions which suitable, the accuracies uncertainties expected, their full potential uses limitations, directions enhancements new developments. SWAT found all three major components (hydrology, sediment, chemical) applicable watershed-scale catchments. promising continuous simulations predominantly watersheds, HSPF mixed urban watersheds. Among DWSM provides balance between simple but approximate computationally intensive and, therefore, storm watersheds.