Temporal and Spatial Distribution Characteristics of Summertime Short-Duration Heavy Rainfall in FuKang

Based on the summertime hourly precipitation data of automatic meteorological stations in Fukang from 2013 to 2021, the temporal and spatial distribution characteristics of the summertime short-term heavy rainfall processes in the study area (one or more cases of hourly precipitation≥10 mm in a day) are analyzed. The results show that the short-term heavy rainfall in Fukang is characterized by the increased occurrence times with the elevation, with unbalanced horizontal and vertical distributions; Affected by the special terrain of Fukang, the special distribution of short-term heavy rainfall in the mountainous areas complies with the occurrence law of summertime flood, exhibiting the feature of more in the west, less in the east, while in the plain, it turns out to be more in the south and less in the north; As for temporal distribution, the most active period of short-term heavy rainfall in the study area is in the middle of August, and the diurnal variation of precipitation in the mountainous areas presents the feature of bimodal distribution, with the active rainfall period from 18:00 BT to 03:00 BT of the following day. The main peak and the secondary peak are at 02:00 BT and 21:00 BT respectively, which is consistent with the conclusion that the high value period of accumulated precipitation on the north slope of Tianshan Mountain occurs at night, and that the single peak form of precipitation from the west to the east is prone to evolve into a bimodal structure. There is a single peak form in the plain, with the active rainfall period of 19:00 BT-24:00 BT and the peaking at 22:00 BT. The extreme short-time heavy rainfall processes of more than 20 mm mainly occur in late June and mid-August.