Modeling diffuse pollution with a distributed approach
León, L.F.; Soulis, E.D.; Kouwen, N.; Farquhar, G.J.
Water Science and Technology a Journal of the International Association on Water Pollution Research 45(9): 149-156
2002
ISSN/ISBN: 0273-1223 PMID: 12079097 Document Number: 542175
The transferability of parameters for non-point source pollution models to other watersheds, especially those in remote areas without enough data for calibration, is a major problem in diffuse pollution modelling. A water quality component was developed for WATFLOOD (a flood forecast hydrological model) to deal with sediment and nutrient transport. The model uses a distributed group response unit approach for water quantity and quality modelling. Runoff, sediment yield and soluble nutrient concentrations are calculated separately for each land cover class, weighted by area and then routed downstream. The distributed approach for the water quality model for diffuse pollution in agricultural watersheds is described in this paper. Integrating the model with data extracted using GIS technology (Geographical Information Systems) for a local watershed, the model is calibrated for the hydrologic response and validated for the water quality component. With the connection to GIS and the group response unit approach used in this paper, model portability increases substantially, which will improve non-point source modelling at the watershed scale level.