An Investigation of Fuzzy Set Theory's Efficiency in Land Suitability Assessment for Irrigated Wheat in Qazvin Province, Using Analytic Hierarchy Process (AHP) and Multivariate Regression Methods

In the course of the present study, the results of parametric approach are compared with those obtained through fuzzy approach using AHP as well as multivariate regression methods for comparisons and investigating the efficiency of the fuzzy method as applied in land suitability assessments. The correlation coefficients between land index and observed yield in the study area through fuzzy approach plus AHP (r=0.91*) and multivariate regression methods (r=0.88*) are more than those in the parametric approach (r=0.85*). Although, the fuzzy set approach offers a higher accuracy and better results for land suitability assessment, the most critical issue in its application to land suitability assessment remains as the choice of membership functions, cross-over points and weight values as regards different land characteristics.