Expres: An expert system for assessing the fate of pesticides in the subsurface.

The expert system described here is designed to aid regulatory personnel in their assessment of the potential for pesticides to contaminate the soil and groundwater environment. The expert system, known as EXPRES (EXpert system for Pesticide Regulatory Evaluation Simulations), consists of existing numerical models which are used to simulate the transport and transformation of pesticides in the unsaturated zone, coupled with a knowledge-based system that guides the user through the choice of all the necessary information for characterizing the physical, meteorological, hydrogeological, pedological and agricultural settings of typical agricultural regions across Canada, as required by the pesticide model. The expert system is designed to be used as a management tool to aid in policy decisions. Thus, its purpose is to provide an assessment of the potential hazards and to identify if further study is warranted.