淮河上游暴雨事件评估模型

Torrential Rain Events Assessment Model for the Upstream of the Huaihe River Basin

暴雨灾害是我国面临的主要气象灾害之一,对其进行评估具有重要的理论和现实意义。该文以气象降水数据为基础建立数据集,采用统计分析的方法建立暴雨事件评估模型,对淮河流域上游的暴雨事件进行评估。该模型选取了4项描述暴雨事件的指标:区域平均日降水量、区域最大日降水量、覆盖范围和持续时间,通过对淮河上游16个站1961—2007年逐日降水量资料的统计分析,按概率分布划分出这4项指标的各等级标准,从而建立暴雨事件等级标准评估矩阵,而需要评估的暴雨事件等级则通过计算该暴雨事件各指标所组成的向量与等级标准评估矩阵中各等级所组成的列向量之间的欧式距离来确定。通过对历史资料及2008年4月—2010年7月发生的暴雨事件实况资料进行评估,发现评估结果与其所造成的实际影响对应较好,说明该模型对暴雨事件等级的划分较为合理。

Torrential rain disaster is one of the most serious meteorological disasters in China,the assessment of which has important practical and theoretical significance.On the basis of precipitation data,statistics analysis is carried out to establish the torrential rain events assessment model,and the torrential rain events which happen in the upstream of the Huaihe River Basin is assessed with this model.Four indicators are selected to describe torrential rain events in this assessment model,which are averaged area daily rainfall, maximum area daily rainfall in area daily,rainfall coverage range and rainfall duration.Through the statistical analysis of historical torrential rain events data,several grades are defined for the four indicators according to the probability distribution,and then the grade standards assessment matrix is established.The degree of the torrential rain events is calculated by the method of the Euclidean distance,through Euclidean distance between the torrential rain events indicator vector and each column vector of the assessment matrix,the degree of this torrential rain event can be determined.Through the assessment of historical and live torrential rain events which happen in the upstream of the Huaihe River Basin,the assessment results correspond well with the actual impact of the torrential rain disaster,which indicates that the degrees of torrential rain events assessed by this torrential rain events assessment model is reasonable.The pre-assessment can be made by this torrential rain events assessment model to publish warning information when the forecast data are used,and the assessment accuracy has a positive effect on the forecast accuracy. Through the assessment of historical torrential rain events by this model,the results show that in 226 historical torrential fain events,there are 47 times belonging to level 1,86 times belonging to level 2,55 times belonging to level 3,25 times belonging to level 4,9 times belonging to level 5,3 times belonging to level 6,and just 1 time belonging to level 7,which are consistent with the theoretical analysis.According to the assessment results,the most serious torrential rain events happen in 2007,which is ccnsistent with the historical facts. The correlation between the assessment levels of torrential rain events and the Wangjiaba water levels passes the test of 0.005 level,inferring that the selection of the assessment region and the assessment results of the torrential rain events of this research are rational. The analysis of the assessment results shows that.the torrential rain events happen 2 days before the peak of Wangjiaba water level,which has important significance to guide the disaster prevention and mitigation. However,the assessments of the influences of torrential rain events are insufficient,which need further research.