基于产汇流理论的设计洪水推理公式方法改进

Improvement of reasoning formula method for design flood based on runoff generation and confluence theory

北京水科院推理公式法的建立、发展及成功应用,是我国水文科学的重要成就之一。水科院法是推理公式的优化,该方法考虑了暴雨时程的变化,在净雨分析时引入产流历时的概念,采用暴雨及平均损失强度进行洪水计算。近年来,实践验证及综合分析表明,水科院法采用的关键参数平均损失强度概化设定存在不确定性。损失强度概化设定实质是设计暴雨推求净雨过程中的扣损问题,而净雨计算可依靠目前较成熟的产汇流理论。利用降雨径流相关法,可推算出最大汇流历时的净雨量,也可计算净雨过程,得到净雨过程与断面出口洪水的对应关系,以避免损失强度概化设定的不确定性,使洪水计算结果接近实际,从而完善了推理公式法。

The establishment,improvement and successful application of the IWHR reasoning formula method,an optimization of the reasoning formula method,is one of the important achievements in hydrology.It considers the time-history variation of rainstorm,introduces the concept of runoff duration in the analysis of net rainfall,and adopts rainstorm and average loss intensity in the calculation of flood.In recent years,the practice and comprehensive analysis show that the determination of the average rainfall loss intensity,a key parameter of the IWHR reasoning formula method,is uncertain.In fact,the problem of the generalization and determination of the rainfall loss intensity is a reduction in the process from design rainstorm to net rainfall,which could be resolved by runoff generation and confluence theory.By using the method of rainfall-runoff correlation,the net rainfall in the maximum confluence duration and the net rain process can be calculated,so the relationship between the net rain process and the flood at the exit section can be formed.Thus,the uncertainty of the generalized loss intensity can be avoided and the flood calculation result is more closer to the reality.Therefore,the reasoning formula method is perfected.