Document Type : Research Paper
PhD student of agrometeorology, Faculty of Agriculture & Natural Resources, University of Tehran, Department of Irrigation and reclamation, Agrometeorology Division, Karaj, Iran
Professor, Faculty of Agriculture & Natural Resources university of Tehran, Department of Irrigation and reclamation, Agrometeorology Division, Karaj, Iran
In this study to segregate Iran's climate precipitation, 130 climate variables were used from 81 synoptic meteorological stations and then 98 combined variables were calculated. Eventually 39 important combined variables were selected for analysis, using backward algorithm. After that by using factor analysis, the selected variables were summarized in six main factors: summer precipitation, spring precipitation and cold month’s rainfall intensity, number of snowy days, longitude, variability index and number of stormy days. These factors explained 82% of total variation in the data. Finally in order to determination of different patterns of precipitation in Iran, Factor scores were grouped by Ward hierarchical clustering algorithm. Using this algorithm six different precipitation climate regions were introduced which are grouped in four small area and two broad ones. Also to increase the homogeneity of broad area, each of the broad regions were divided into two smaller areas, regarding to dendrogram of selected meteorological stations.