Abstract:

In order to assess the rainstorm disaster quantitatively, evaluate its risk and give the good guidance on the high-risk area of rainstorm in Zhejiang Province, where the rainstorms occur frequently. The map of frequency and intensity of rainstorm in the regional scale in Zhejiang Province were drawn to analyze the temporal and spatial distribution of the rainstorm, using observation data of 66 weather stations during 1971 to 2010, and combined with social-economic data in the statistical yearbook, the vulnerability index, evaluation index and the storm risk index were calculated based on GIS. The results showed that rainstorms were usually occurred in western, southern and southeast coast of Zhejiang. High-frequency rainstorm in eastern area was caused by typhoon weather system while in western area was due to the rainy season. May to September was the concentration period of rainstorm, rainstorm days in June accounted for 26% of the full-year. The frequency of rainstorm expressed an increasing trend at inter-annual scale since the late 1980s. Damaged large areas which resulted by the rainstorms in Zhejiang distributed in the developed cities and coastal regions. The risk analysis showed that the risk in southeast coast, northeastern and western regions were higher, while the risk in central, western mountainous areas and underdeveloped region were relatively lower. Assessing the risk of rainstorm at real-time had an active role in the promotion of disaster prevention, because rainstorm disaster influenced the socio-economic significantly. The rainstorm risk assessment by using the risk indexes was applied on the typical rainy season in 2011, the results showed that evaluation by this method and the actual situation was consistent, the risk indexes could be applied to rainstorm disaster assessment in real-time.