Rainfed based Regionalization of the East Part of Urmia Lake Basin through Introducing Rainfed Evaluation Indices

For reducing the destruction of water resources and for resolving the future populations, needs for food, the replacement of rainfed farming instead of water farming will be inevitable. According to the importance of the agricultural sector, determining indices to identify the fertile lands for cultivation of rainfed wheat is essential. For this purpose, to evaluate the yield of rainfed crop at the East part of Lake Urmia, two indices Interval Ratio and Partial Interval Ratio, for identification of the eligible areas for rainfed farming, were introduced using irrigation depth, irrigationintervals, and daily rainfall in corresponding with the time intervals. Clustering of the indices and yield of rainfed area were done with a K-means method. Regionalization of the obtained clusters for the yield and indices were done in GIS environment. Results of the regionalization showed that between the two introduced indices the Partial Interval Ratio index has the more compatibility to region reality, So the Partial Interval Ratio index selected for evaluating the rainfed regions. To identify the fertile rainfed regions of crop yield, the isoline of the yield of rainfed and index (Partial Interval Ratio index) was used. The results showed that in the northwest and central parts of the studied area the yield and Partial Interval Ratio index were increased, which indicated the good potential of rainfed farming in these areas. Therefor the fertile regions based on the introduced index were at the central and northwest parts of the studied area.