Land Suitability Evaluation Using TOPSIS Method and Its Comparison with Parametric Methods for Maize Production in Part of Qazvin

Land suitability evaluation by parametric methods (Story and Square Root) are sometimes incompatible with the reality of the field because of the low achieved values of the index. Therefore, the use of new multivariate decision-methods, considering the interactions of the criteria, including the new TOPSIS approach, can be investigated. Based on the grided sampling method, 22 soil profiles were studied in 8210 hectares. The genetic horizons were sampled and physicochemical properties analyzed. Based on the integration of soil unit map and slope, 17 land units were extracted and finally, land suitability maps were prepared for all three Story, Root and TOPSIS parametric methods in land units and GIS. Comparison of the values of land suitability index and yield of corn in the studied units showed that the correlation coefficient are 0.76, 0.76 and 0.78 for Story, TOPSIS and Square root method respectively. The results of this study showed that the Square root method has more validity than the other two methods