基于GIS的浙江省暴雨灾害及其危险性评价

为了对暴雨频发的浙江省进行暴雨灾害的定量评估和危险性评价，以加强对高危地区的暴雨防御指导，利用浙江省66个气象站1971-2010年气象观测资料，绘制浙江各地暴雨出现频数和强度分布图，分析暴雨的时空分布特征，并结合统计年鉴中社会经济数据，采用承载体易损性指数、暴雨强度指数及暴雨危险性指数等评价指标，利用GIS技术分析各指数的空间分布。结果表明，浙江省暴雨频发区主要分布在西部、南部和东南沿海地区，台风与梅雨是引发浙东和浙西暴雨的主要天气系统。5-9月是暴雨集中期，其中6月暴雨出现频数占全年暴雨日数的26%。自20世纪80年代末以来，浙江各地暴雨频数的年际变化呈一致性的增加趋势。浙江受暴雨危害较大的地区集中在经济发达的城市和沿海地区，危险性分析表明，浙江东南沿海、东北部和西部地区暴雨灾害的危险性较大；而中部、中西部山区和经济欠发达地区，暴雨灾害的危险性相对较小。暴雨灾害对社会经济影响较大，实时开展暴雨灾害的危险性评估，对促进防灾减灾具有积极作用。通过应用暴雨危险性指标对2011年浙江典型梅汛期暴雨灾害的危险性分析表明，本研究利用的评价方法与灾害实际影响程度基本一致，此方法可应用于浙江暴雨灾害的评估和危险性评价。

The Rainstorm Disaster and Its Risk Assessment Based on GIS in Zhejiang Province

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.