基于云模型的城市极端雨洪灾害风险评价

Urban extreme rainstorm flood loss based on cloud model

构建最大24 h降雨量、平均淹没水深、淹没历时、受灾人口率、受灾面积率、GDP损失率6个指标,综合运用层次分析法和熵权法确定各指标的权重,通过云模型定量评价各指标下风险的等级,建立基于正态云模型的极端雨洪下城市洪水风险综合评价模型。对景德镇极端雨洪引发的洪水进行风险评价,得到1990—2012年景德镇每年的风险等级,找出引发洪水风险的关键因素。研究结果表明,景德镇深受洪水的影响,平均淹没水深与淹没历时对洪水产生的风险有重大影响。提出通过大量植树造林,增加透水面积;新建排水设施,清理城市排水管道,可以有效降低景德镇极端雨洪带来的风险。

Using the existing theoretical approaches,six assessment indices are considered,that is, the maximum 24 h rainfall, average inundated depth,inundated duration,affected population,affected area and GDP loss rate. The AHP and entropy weight method are integrated to determine the weight of each index. The loss level under each index is quantitatively assessed by using the cloud model. An urban extreme rainstorm flood damage evaluation model is established based on the normal cloud model. The flood losses induced by extreme rains in Jingdezhen are evaluated,and the annual loss levels from 1990 to 2012 are obtained. The key factors to cause flood damages are found. The results show that the average inundated depth and duration have significant impact on the flood losses in Jingdezhen. Some measures are put forward to effectively reduce the losses caused by the extreme rainstorms:( 1) tree planting and improvement of pervious area;( 2) construction of drainage facilities and cleaning of urban drainage pipes.