江苏省暴雨洪涝灾害特征分析

Characteristic analysis of Rainstorm-induced flood disaster in Jiangsu Province

通过引入灾度模型,对2004-2013年江苏省253次暴雨洪涝灾情进行了综合评估,给出了灾害等级的划分标准,分析了暴雨洪涝灾害发生频率与降雨量间的关系,确定了临界雨量,构建了灾度预测模型。结果显示:江苏省的暴雨洪涝灾害以轻灾及中灾居多。灾害多发且较重的区域位于西北部、东部及长江沿江地区;灾害少发且较轻的区域位于沿淮及苏南地区。梅雨锋引发的灾害频次最多,热带系统引发的暴雨灾害的灾度最大,而中小尺度对流系统所引发的灾害频次最少、灾度最小。引发暴雨洪涝灾害的临界雨强是18~20 mm/h,过程最大24 h降水量的临界值为35~40 mm。通过选用降水量因子建立的逐步回归方程对轻灾及中灾的空报率偏高,但对大灾及重大灾害的预测结果还是可以接受的。

By introducing the calculation model of disaster magnitude,the rainstorm flood disaster data of Jiangsu Province from 2004 to 2013 was assessed and a gradation criterion of rainstorm flood disaster was given. On this basis,this paper analyzes the relationship between occurring frequency of rainstorm flood disaster and rainfall,determines the critical rainfall threshold and constructs a disaster magnitude prediction model. The results show that light and medium disasters of rainstorm flood occurr most frequently in Jiangsu Province. The regions where the disaster occurs frequently and seriously are located in the northwest,the east and the area along the Yangtze River,while the regions where the disaster occurs infrequently and lightly are located in the area along the Huaihe River and the south of Jiangsu Province. The rainstorm flood disaster induced by plum rains front occurr most frequently,the disaster magnitude of rainstorm flood disaster induced by tropical system is the maximum,while the disaster induced by meso- and micro- scale system occurs most infrequently and the disaster magnitude is the minimum. The critical rainfall intensity inducing vainstorm flood disaster in Jiangsu Province is 18 ~ 20 mm/h,the critical 24 h maximum rainfall is35 ~ 40 mm. The stepwise regression equation established by the selected precipitation factor has a bit high prediction rate of light and medium disaster,while the prediction results of large and major disasters are acceptable.