Prototype SDSS for using probability analysis in soil contamination

The purpose of this study is to demonstrate the benefits of applying spatial decision support system (SDSS) methodologies for assessing soil contamination problems. A nonparametric geostatistical technique, indicator kriging (IK), was used to determine the probability distributions for characterizing the uncertainty in the unsampled area. Such distributions over a contaminated site allow mapping of block maps of the probability above some maximum allowable limit, estimate the risks of decisions, and provide information for remediation assessment. Geographical information systems offer spatial analysis and data management capabilities that can benefit IK analysis. A prototype system, PASCA (Probability Analysis for Soil Contamination Assessment), was developed for this study. It utilizes a menu-driven interface to combine the Taiwan geographical database and models for IK analysis. PASCA was designed to specially aid users in preliminary screening of remediation priorities and in designating contaminated soil blocks that need additional sampling. The application of PASCA is analyzed through a case study involving the heavy metal cadmium.