Fuzzy Screening for Land Suitability Analysis

Screening procedures are typically operationalized in GIS by means of Boolean operations using conjunctive or disjunctive decision rules. There are several conceptual and technical problems with the conventional screening methods. The methods require fairly detailed a priori information about the cut-off values, aspiration (target) levels, or preferences with respect to the relative importance of screening criteria. They may be complex, time consuming, and not totally amenable to quantitative analyses in situations involving categorical or mixed data. This paper proposes a GIS-based fuzzy screening method that avoids some of the difficulties. The method requires only a qualitative scale for land suitability evaluation with respect to a number of attributes. It also allows for assigning to each attribute a different degree of importance. The procedure results in dividing the set of alternatives (parcels of land) into two subsets: acceptable (feasible) and unacceptable (infeasible). The fuzzy screening method is illustrated using a hypothetical problem and implemented in a real-world situation involving industrial land development in the Villa Union region of the Sinealoa province on the Pacific coast of Mexico.