تحليل زماني - مكاني بارش هاي فرين روزانه در ايران

An agglomerative hierarchical cluster analysis then applied to highest hour precipitation coefficient matrix. This analysis shows that there are four main precipitation regions in Iran. In region No.r about percent of annual precipitation may occur just in ^ hours. In region No.^ about > • • percent of annual precipitation may occur just in ^ f hours. These regions more subject to the extreme rainfall. These two regions are located in southern half of Iran, along Persian Gulf and northern coasts Oman Sea. The possibility of heavy r f hour precipitation exists throughout Iran, except southern coasts of Caspian Sea in four months Dec, Jan, Feb and March. Extreme ^ hour precipitations of Caspian Sea coasts have occurred in Aug, Sept and October. Because of the weakness of westerlies, possibilities of extreme x f hour precipitation didnʹt exist in southern half of Iran from April to November.