A fuzzy-petri net formalization of expert information for groundwater risk management

The characterization and management of risk in groundwater contamination problems can be improved using subjective expert information. Petri Nets are graphical and mathematical modeling tools for describing information processing systems whereas Fuzzy Set Theory provides a quantitative environment for representing subjective information. The framework used herein is a Fuzzy-Petri Net (FPN), a synergy of Petri Nets and Fuzzy Set Theory. We demonstrate features of the FPN model used for managing a knowledge base available for the solution of a health risk based design problem of benzene contaminated groundwater. Statements of public-health professionals on the toxic behavior of benzene constitute the FPN's knowledge base ( Ozbek and Pinder, 2000 ). First, the net representation of the knowledge base is utilized to construct a subnet which is based on expert information concerning the inquiry, risk-informed concentration constraints for an optimization problem in this case. The resulting subnet is then exploited to characterize the concentration constraints.