ntroduction and a comparison among gridded precipitation database of asfazari with gpcc, gpcp and cmap

precipitation plays an important role in the global energy and water cycle. special interest in long-term precipitation analyses arises from the need to assess climate change and its impacts on all spatial scales. based on this demand national and international organization initiated and support many research and monitoring programs. there are a lot of centers developing gridded precipitation data in various spatial and temporal scales and make them available freely. in this paper we want to introduce national database alongside cmap, gpcp and gpcc datasets and then compare them with national database for iran. the comparison showed us that there is a high coefficient of correlation between asfazari and the other database especially gpcc during rainy seasons this correlation was very high.