Site suitability assessment and mapping for rice cultivation using multi-criteria decision analysis based on fuzzy-AHP and TOPSIS approaches under semihumid ecological condition in delta plain

Abstract

Many areas in Turkey are ecologically suitable for paddy cultivation, and their yield per hectare is above the world average. Despite this fact, the amount of production cannot supply the amount of consumption. This situation causes Turkey to be a country that imports rice. This study was carried out within a 1266.7 ha area in the Bafra alluvial delta plain, which is located in Samsun, which is one of the most important paddy cultivation areas of Turkey. The purpose of the study is to determine the areas that are suitable for paddy (Oryza sativa) cultivation among the soils that have various physicochemical characteristics, which are formed on the alluvial deposits that were carried by the Kizilirmak River, with the help of multi-criteria decision analysis and geographic information system. In the study, nine different soil criteria were used as texture, drainage, pH, EC, CaCO3, TN, AvP, AvK and AvZn. Fuzzy Analytic Hierarchy Process was used for determining the levels of importance of the criteria and Technique for Order Preference by Similarity to Ideal Solution methods were used for ranking the study areas. According to the obtained results, about 64.1% of the area is highly suitable and suitable for paddy cultivation and 15.2% of the area is less suitable. Also, 20.8% of the total area constitutes currently and permanently unsuitable areas.