Investigation of existence of trend in annual precipitation of Hamedan Province using Mann-Kendall method

The purpose of this study was to, investigate the changing trend of precipitation in Hamedan province by considering its temporal and spatial variability, and determining regions where these changes were at their maximum for long-term water resource management. In this research, the annual rainfall was collected at 23 different meteorological stations situated throughout Hamedan Province. The collected data were analyzed to determine the probable climate change during period from 1982 to 2006 (24 years), based on the Mann-Kendall method. The results showed that Aghajanboulaghi, Touserkan and Ghahavand had a significant increasing trend and the others did not show any trend. The sudden variations of annual rainfall presented at the stations illustrated fluctuations of climate of the region. These different results indicate the spatial irregular rainfall variability of the region. Therefore, more complementary investigation is necessary. Using more stations and longer rainfall data and application of the method based on the temperature characteristics of region could be effective for climate change identification of the region.