推求谢尔曼单位线的逐步滤波优化方法

Calculate Sherman unit hydrograph by stepwise filter optimization method

从1932年谢尔曼提出单位线概念至今,谢尔曼单位线一直是水文预报员解决规律复杂的流域汇流的基本方法。笔者对目前常用的单位线推求方法及存在的问题进行了分析,并提出了的逐步滤波优化方法。文章给出了逐步优化方法的目标函数及约束条件,阐述了滑动平均滤波器和滑动多项式滤波器原理,并介绍了运用逐步滤波优化方法推求单位线计算流程。笔者采用该方法对不同流域水系的谢尔曼单位线进行了率定,在实际应用中取得了较好的效果。

Since 1932 when Sherman put forth a unit hydrograph concept, Sherman unit hydrograph has been a basic hydrological method for solution of complex runoff concentration. The authors analyze the current methods of unit hydrograph calculation and their problems, and present a stepwise filter optimization method. This paper gives objective function and tconstraint conditions for this method, elaborates the theory of moving average filter and moving polynomial filter, and demonstrates a procedure for its calculation of unit hydrograph. Its application to calculation of Sherman unit hydrographs for different river basins has achieved satisfactory results.