Coupling SoilFug model and GIS for predicting pesticide pollution of surface water at watershed level

A multimedia fugacity-based model (SoilFug) was applied to predict pesticide pollution of surface water in a river basin of about 400 km(2) in northern Italy. To account for the heterogeneity of environmental characteristics of the territory, a detailed description of the environmental scenario (hydrological network, land use, rainfall, soil properties, etc.) was made by using a Geographical Information System (GIS). Fourteen Uniform Geographic Units (UGUs) were defined for applying the SoilFug model on a modular basis. UGUs were then combined to predict river concentrations. A validation of the approach, made by comparing predicted data with the results of experimental monitoring on selected chemicals, gave satisfying results. This approach, based on the combination of a multimedia fugacity model with GIS, proved to be a suitable tool for the site-specific prediction of environmental distribution and fate of chemicals on a river basin scale.