APPLICATION of FUZZY LOGIC to ENVIRONMENTAL RISK ASSESSMENT

Risk assessment using artificial intelligence techniques can reduce costs and confer agility to the decisions. When knowledge is intricate, fraught with uncertainties or little known about the inter-variable relationships, Fuzzy Expert Systems can be useful at gathering disperse information and accumulating certainty about a fact. Frequently the knowledge of professionals as well as field observations are the main source of information to establish a knowledge base capable of evaluating critical situations. This work presents the technique of Fuzzy Logic used in the Expert System HgEx developed to diagnose mercury bioaccumulation risk from gold mining operations. It is shown how the system accommodates imprecise data input for variables, such as background level as well as how measurements are transformed into linguistic expressions with respective Degrees of Belief to be handle in a heuristic model (neural equations - Weighted Inference Method). Linguistic terms to express risk levels have the same practical effect as complex mathematical models which usually demand high costs, much data and skill to quantify the relationships between each factor and bioaccumulation.