基于SCS模型和新安江模型的雨量预警指标综合动态阈值对比

Comparison of comprehensive dynamic threshold of rainfall warning indicators based on SCS model and Xin'anjiang model

为了解决下垫面条件复杂性和前期影响雨量不确定性给小流域山洪预警带来的难题,选取广东省罗定市太平镇太北村和罗镜镇大平岗村两个小流域作为研究对象,通过水位流量关系和致灾水位插值得到致灾流量,由致灾流量通过三角汇流曲线反推得到临界产流量,考虑前期影响雨量的因素,分别通过SCS模型和新安江模型反推得到动态临界雨量,并与广东省用国家新技术方法算出的临界雨量进行对比。结果显示,两种模型在临界雨量的计算上均满足预警要求,但基于新安江模型计算得出的结果偏安全,在山洪预警中更加可靠。

In order to solve the problems caused by the complexity of underlying surface conditions and the uncertainty of antecedent precipitation in mountainous small watershed,two small watersheds,Taibei village in Taiping Town and Dapinggang village in Luojing town of Luoding City,were selected as the research objects.The disaster-causing flow,which is interpolated by the stage-flow relation and the disaster-causing water level,can be used to calculate the critical runoff with the method of triangle confluence curve.With the consideration of the antecedent precipitation,SCS model and Xin'anjiang model are applied to calculate the dynamic rainfall threshold reversely,and the dynamic rainfall threshold will be compared with the critical rainfall calculated by the national new technology method used in Guangdong Province.The results show that both models meet the requirements in the calculation of rainfall threshold.Relatively speaking,the results based on the Xin'anjiang model are safer and more reliable in the flash flood warning.