Characteristics of Short- Duration Heavy Rainfall During the Warm Season in Xinjiang

Based on the hourly precipitation data from the 105 stations during May to September of 2005-2015 in Xinjiang，the spatiotemporal characteristics and precipitation contribution ratios of short-duration heavy rainfall(hereafter SDHR) in Xinjiang were investigated. The results indicate that the frequency of SDHR was characterized by higher in northern Xinjiang than southern Xinjiang and higher over slope of the mountainous than valleys and deserts.The contribution rate of SDHR in southern Xinjiang was higher than that in northern Xinjiang. The seasonal north-south shift with the position of SDHR high frequency zone was closely related to the north-south passage of solar radiation and subtropical zone from spring to autumn. Monthly and dekad variations of SDHR average frequency acted as single-peak type, but the morphologies were different. The frequency of SDHR presented rapidly increases and rapidly decreases in northern Xinjiang while that rapidly increases and slowly decreases in southern Xinjiang. The diurnal variations of SDHR average frequency had three peaks in northern Xinjiang, and the most active diurnal peak was at 18:00-19:00 BT.