基于分布式水文模型的山洪预警临界雨量分析——以涔水南支小流域为例

Flash Flood Early-Warning Indicators Based on Distributed Hydrological Model——A Case Study in South Branch of Censhui Watershed

基于我国山洪灾害雨量预警的需求,介绍了采用分布式水文模型分析临界雨量的基本思路与方法,以湖南省涔水南支小流域为例,探讨了流域内3个典型预警对象动态临界雨量的确定方法并获得了相应成果。分析认为,分布式水文模型可以较为详细地设置流域各部分产流、汇流以及洪水特征,有利于模拟山丘区小流域洪水,是同时分析多个对象临界雨量的有效方法;分析预警地点的预警流量是非常重要的前提和基础,流域汇流时间是非常重要的预警时段,应根据流域特征和防灾对象特点,确定一系列典型的预警时段;流域尺度土壤含水量对临界雨量有重要影响。

Using DHM (Distribution Hydrological Model) technique with detailed sub-basin delineation, this study introduces basic concepts and methods of analyzing warning indicators for flash flood early warning. Taking south branch of Censhui watershed in Hunan Province as an example, 3 typical early warning indicators for flash flood dynamic early warning were investigated. This research il ustrates that detailed watershed characteristics can be modeled in-depth by further delineate the watershed into smal er sub-basins to simulate spatial distribution of various basin parameters. The resulted runoff and flood hydrographs show better accuracy at al 3 early warning stations. It further confirms that time of concentration of a watershed is an important factor to warning rainfal duration, and the antecedent soil moisture condition of the watershed has significant impact to the critical rainfal .