Land Suitability Evaluation for Rice Cultivation Using AHP-TOPSIS Methods Based on FAO Model in GIS Environment (Case study: Zanjan province)

Land suitability evaluation for agricultural products is one of the important initial works for sustainable development, prevent land degradation and biological resources conservation for the future. With respect to theimportance of rice as a strategic product in the country, this paper presents a land suitability evaluation model based on FAO framework in Zanjan province using of Geographic Information System (GIS) and multi-criteria decision-making. In this study, 4 environmental parameters (water resources, climate, soil, topography) and 5 social-economic parameters (human and machine labor, distance from roads and markets, the number of cooperatives) were used for land suitability evaluation. AHP and TOPSIS method were used respectively for determining the relative weight of factors and their aggregation. Next, the resulted map was classified based on FAO framework and a class as constraints area. According to the results, from environmental perspective 114.36 km2 (0.51%), and after removing unsuitable environmental areas, from thetotal suitable area, from socio-economic perspective 73 km2 (0.33%) were identified as ahigh suitable class (S1). The overall accuracy of the first and final map compared to land use map 74.7% and 89.3% was obtained. According to our finding, most important parameters in land suitability evaluation for rice cultivation are water resources, climate, soil, machinery labor and topography and also the lack of water and soil salinity are the main obstacles to rice cultivation in the province.