基于雨型的小流域雨量预警指标不确定性研究

An Analysis of the Uncertainty Rules of Mountain Flood Disaster Warning Indexes Based on Rainstorm Rainfall Pattern in Small Watersheds

雨型对设计洪水具有潜在影响,而设计洪峰值的精度直接影响雨量预警指标的准确度,因此有必要探究山丘区小流域雨型对雨量预警指标的不确定性影响。在小流域降雨特性分析的基础上,通过设计暴雨洪水计算、水位流量反推法确定不同雨型的雨量预警指标,分析雨型和雨量预警指标间的响应关系。以河南省裴河小流域夏湾组作为预警对象,实例结果表明:雨型对山洪灾害雨量预警指标影响较大,实际工作中需要考虑其合理性;在同一预警时段内,雨峰偏前时对应的临界雨量是雨峰偏后时的1.67倍,雨峰居中时的临界雨量是雨峰偏后时的1.39倍。雨型的合理性及其对雨量预警指标影响的定量化研究,为小流域山洪灾害预警指标分析计算提供了技术支撑和经验参考价值。

As the rainfall pattern has a potential impact on the design of the peak flow,and the accuracy of the design peak flow directly affects the reliability of rainfall warning indicators,it is necessary to explore the influence of rainfall patterns on rainfall warning indexes in small watersheds,and between the two response relationship.Based on an analysis of rainfall characteristics,the design rainstorm flood calculation method and inversion method of water level/flow are used to obtain rainfall early warning indicators for different rainfall patterns,the impact relationship between rainfall pattern and rainfall warning indicators are compared and analyzed.This paper takes the Xiawan in Peihe Watershed Basin of Henan Province as an early warning object.The results show that the rainfall pattern has a great impact on the early warning indicators of mountain flood disasters,and the rationality of the actual work needs to be considered.In the same early warning period,rainfall warning indicator calculated at the front of rainfall peak position is 1.67 times that at the behind of rainfall peak position,rainfall warning indicator calculated at the middle of rainfall peak position is 1.39 times that at the behind of rainfall peak position.The rationality of the rainfall pattern and its quantitative research on the impact of the rainfall warning indicators provides a technical support and empirical reference value for the analysis and calculation of early warning indicators of mountain flood disasters in small watershed.