Regionalization of the East Part of Urmia Lake Basin Based on Impact of Seasonal Precipitation on Rainfed Yield using the Ward and K- Means Methods

The supply to manage and optimal use of water in agriculture is essential for management and conserve water resources. This study aimed to evaluate the effect of seasonal precipitation fluctuations on annual rainfed yield. Monthly precipitation data for 26 rainfall stations with Statistical period 1992 to 2014 of the east part of Urmia Lake basin were used. Clustering were done with Ward and K-means methods. The homogeneity of cluster were checked through H-Statistics method and homogeneous clusters were shown in GIS environment. The effect of seasonal precipitation were compared with annual rainfed yield. Results showed that the effect of precipitation in the spring, autumn and winter in the amount of rainfed yield is positive and precipitation in these seasons has a remarkable effect on increasing yield, In the three seasons precipitation cause increase of soil moisture storage that summer is consumer this storage But in the summer there is an inverse relationship between precipitation and annual rainfed yield. In order to identify areas combined with increased precipitation and rainfed yield Iso-line of precipitation seasons with the rainfed yield of study area was drawn. The results of this lines showed that in the spring, autumn and winter at the Daryan, Lighvan, Khormazard, Sahlan, harvy, Saidabad, ShirinKandy, Ghorigol, Tabriz and Moghanjigh increased amount of pricipitation is directly related to the amount of yield. These areas can be introduced more eligible rainfed Cultivation in East Lake Urmia and recognition the effects of precipitation on yield rainfed areas can be more practical and reliable.