Silvia: A Decision Support System for Environmental Impact Assessment

Abstract

A software package has been developed, containing a methodological framework and a decision support system for environmental impact assessment (EIA) problems. The package is named SILVIA (the acronym, in Italian, stands for Interactive Software for Environmental Impact Assessment) and includes three parts, concerning, respectively, the preliminary phase, the analysis phase and the decisional phase of an EIA procedure. The first part — which is named SERENA — is a data base containing information about Italian environmental legislation, check lists, existing data, available models and methods, previous case studies and bibliographic references. It is being developed at present and is not described here. The second part — which is named GAIA — is based upon spread sheet techniques, and makes it possible to create trees and matrices at different aggregations levels, to coordinate both the results of prediction models and the qualitative estimates and to represent the single steps of the analysis phase. The third part — which is named VISPA — is based upon multi-attribute analysis techniques, including: (a) elimination of dominated alternatives by the Pareto criterion, (b) preference analysis, (c) concordance and discordance analysis, (d) sensitivity analysis. The package has been developed on an IBM-PC and is user-friendly. The interactive procedure all over the steps makes it possible to really involve both the decision maker and the interested groups, in order to clarify the actual entity of conflicts and to provide information aiming and some more rationality and transparency in decision making.