池州市近10 a主要暴雨灾害及致灾性分析

Analysis of Major Rainstorm Disasters and Their Disaster Causing in Chizhou City in Recent 10 years

利用池州市2007—2016年共10 a的暴雨灾害资料和140个区域雨量站及4个国家基本站(贵池、东至、石台、青阳)逐小时降水资料,对池州市近10 a主要暴雨灾害进行分级并分析其致灾性,结果表明:①池州市近10 a主要暴雨灾害特征与短历时强降水分布特征及池州市地形分布特征具有明显关联性;②05时前后是池州市暴雨灾害的最强致灾时段,这主要是此时段为短时强降水高发时期,一旦发生持续性短时强降水将会造成严重的暴雨灾害;③东至县中南部、贵池南部山区及九华山区域为暴雨灾害高发区域,其原因是东至县具有喇叭口特殊地形,而其他地区多为山区,同时由于池州市常位于副高西北侧,汛期西南气流输送比较强盛,通过山区地形的强迫抬升和动力抬升作用容易触发对流,产生强降水过程,造成暴雨灾害。

Based on the rainstorm disaster data of 10 years in Chizhou City from 2007 to 2016,the hourly precipitation data of 140 regional rainfall stations and 4 national basic stations(Guichi,Dongzhi,Shitai,Qingyang)in Chizhou City,the main rainstorm disasters in Chizhou City in recent 10 years are classified and analyzed.The results show that:①The characteristics of main rainstorm disaster in Chizhou city in recent 10 years are obviously correlated with the distribution characteristics of short-duration heavy precipitation and the terrain distribution characteristics of Chizhou City;②Around 5∶00 a.m.is the strongest period of rainstorm disaster in Chizhou City,which is mainly the period of high occurrence of short-term heavy rainfall.Once sustained short-term heavy rainfall occurs,it will cause serious rainstorm disaster;③The area of the south central part of Dongzhi County,the south mountainous area of Guichi and Jiuhua Mountain is the area of high occurrence of rainstorm disaster,the reason is that Dongzhi County has trumpet.In addition,Chizhou City is often located in the northwest side of the subtropical high,and the southwest air flow is relatively strong during the flood season.The forced uplift and dynamic uplift of the mountainous terrain are easy to trigger convection,produce heavy rainfall process and cause rainstorm disaster.