缺资料山区中小河流成灾临界雨量计算分析

Calculation and Analysis of Disaster Critical Rainfall of Small River in Mountain Area

山区中小流域在暴雨条件下易形成山洪灾害,其历时短、强度大、暴涨暴落,加之中小河流建站时间短,雨量站点布设密度不够,预警难度大。为提高预警精度,采用雨洪同频频率反推法对缺资料山区中小河流不同时段成灾临界雨量进行计算。雨洪同频频率反推法结合了实际防护对象受灾情况,仅采用雨量信息计算预警雨量临界值,方法简单易行,实用性较强,能及时、准确对中小河流洪水预警。经实际洪水验证,雨洪同频频率反推法计算的各时段成灾临界雨量均在允许误差范围内。因此,雨洪同频频率反推法可作为缺资料地区洪水预警参考指标计算方法之一。

Mountain flood disaster is easy to form in small and medium-sized river basins in mountainous areas under the condition of rainstorm,which is characterized by short duration,high intensity,surge and sudden fall.In addition,small and medium-sized river stations are built in a short time,and the rainfall station layout density is not enough,which makes it difficult to warn.In order to improve the early-warning accuracy,the critical rainfall of disasters in different periods of small and medium-sized rivers in mountain areas with lack of data was calculated by using the same frequency method of rain and flood.The method of the same frequency of rain and flood is combined with the disaster situation of the actual protection object,and only the rainfall information is used to calculate the critical value of the early warning rainfall,more timely,accurate flood warning of small and medium-sized rivers.After actual flood verification,the critical rainfall for each time period calculated by the same frequency inverse method of rain and flood is within the allowable error range.Therefore,the same frequency inversion method of rainfall and flood can be used as one of the calculation methods for flood warning reference indicators in areas with limited data.