Evaluation of Environmental Capability of West Azerbaijan Province in Canola Cultivation Based on AHP Method and TOPSIS Methods

Canola is the world third leading oil seed after soybean and oil palm by producing 15 percent of the global plant oil. Climate، topography and lands capability are the most important environmental factors on which the crop production capability in a region depends. Therefore by evaluating these factors one can identify suitable lands for canola cultivation. In the present study، the climatological data such as temperature، precipitation، growth degree day، relative humidity، freezing days، and sunshine hours were collected from the West Azerbaijan province synoptic and rain gauge stations (since their installation untill 1388) which were associated with the phenologic stages of canola growth. In addition to the climatological data، earth resources like topographic layers، lands capability، soil depth and land-use were analyzed focusing on the climatological and ecological requirements of canola. After generalizing the data and processing by using ArcGIS، their corresponding information layers were derived. In order to prioritize and assess the criteria and information layers in relation to each other، the multi criteria decision method was employed based on analytical hierarchy process. Then، combination and spatial analysis of the information layers using TOPSIS model and GIS capabilities were done and the final capability ecological evaluation layer for canola cultivation was produced. Based on the obtained results، the province lands were divided into four categories of highly suitable (%18. 6)، suitable (%34. 4)، moderate (%32. 1) and weak (%14. 7) lands on the basis of the environmental and climatologocal potentials for canola cultivation.