Spatio-temporal variation of rainstorm flooding disaster events in Northern Xinjiang from 1981 to 2019

Based on the 1394 rainstorm flooding disaster events occurred in the 38 counties or cities in Northern Xinjiang from 1981 to 2019, we have analyze the characteristics of spatio-temporal variation of rainstorm flooding disaster events in Northern Xinjiang in recent 39 years, by taking such the evaluation factors as the occurrence numbers of rainstorm flooding disaster events and the death toll, collapsed house number, collapsed shed number, dead livestock number, and disaster-affected crop area to establish the rainstorm flooding disaster loss index using a variety of statistical methods. The results show that most of rainstorm flooding disaster events occur in Bortala Mongol Autonomous Prefecture, Ili River Valley and Altay Prefecture. The rainstorm flooding disaster events above the severity level are distributed in Ili River Valley and Altay Prefecture, and those above the extremely severity level mainly occur in Huocheng County, Yining County, Gongliu County, Nilka County and Xinyuan County of Ili River Valley. Monthly variation of the occurrence numbers of rainstorm flooding disaster events and the death toll, disaster-affected crop area shows a single-peak type, while that of collapsed house number, collapsed shed number and dead livestock number shows a bimodal pattern. The annual occurrence numbers of rainstorm flooding disaster events show a significant linear increasing trend, and the annual disaster loss index shows a weak increasing trend. The disaster intensity for the rainstorm flood has been increasing in the inter-decadal time scale. The precipitation days above the levels of heavy rain and rainstorm are the main climate factors affecting the inter-annual variation of rainstorm flooding disaster events in Northern Xinjiang.