Identification of Land Potential and Characterizing Limitations for Irrigated Wheat Cultivation in a Part of Qazvin Plain Land Using Fuzzy and AHP Techniques

Accurate assessment of land suitability for agricultural production plays an important role in reducing the effects of land degradation. The aim of this study was to apply fuzzy, AHP and GIS techniques to determine the degree of land suitability for wheat production in lands of about 61,000 ha located in Qazvin plain. By Investigating the land use maps, geology, topography, slope and satellite image of the region, the delineation of primary soil units was separated, then in the separated units, profiles were excavated and described, and soil horizons were sampled. Based on the characteristics of representative profiles in each map unit, land suitability assessment for wheat cultivation was performed using fuzzy method with AHP and square root method and land suitability map was prepared in GIS environment. According to the results of AHP-fuzzy method 48169.1 ha (78.2%) of the land are moderately suitable (S2), 9086 ha (14.7%) marginally suitable (S3) and 4346.3 ha (7.1%) currently unsuitable (N1). The most important limiting characteristics were slope, pH, ESP, drainage and soil salinity. The results showed that the fuzzy method integrated with AHP was able to evaluate accurately with high value of determination coefficient between land index and yieldcompared to the parametric method of the square root and the modified square root due to determining the appropriate limits of critical points, suitable weights for characteristics, use of fuzzy logic relations and principles and suitable membership functions. Therefore, the mentioned integrative method can be an accurate and effective method for better planning and management of land use for agricultural production.   Identification of Land Potential and Characterizing Limitations for Irrigated Wheat Cultivation in a Part of Qazvin Plain Land Using Fuzzy and AHP Techniques