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 pesticid e pollution of surface water in a river basin of about 400 km(2) in norther n Italy. To account for the heterogeneity of environmental characteristics of the territory, a detailed description of the environmental scenario (hyd rological network, land use, rainfall, soil properties, etc.) was made by u sing a Geographical Information System (GIS). Fourteen Uniform Geographic U nits (UGUs) were defined for applying the SoilFug model on a modular basis. UGUs were then combined to predict river concentrations. A validation of t he approach, made by comparing predicted data with the results of experimen tal monitoring on selected chemicals, gave satisfying results. This approac h, based on the combination of a multimedia fugacity model with GIS, proved to be a suitable tool for the site-specific prediction of environmental di stribution and fate of chemicals on a river basin scale.