数字滤波法分割基流的论证

Argument for Base Flow Separating by Digital Filtering Method

基流是河川的重要组成部分,基流划分的正确性直接影响对流域的水文分析,如流域的降雨径流关系、坡面汇流等。应用修改后的适用于场次洪水的数字滤波法及斜线分割法对总径流进行分割,并用分割后的地面径流与降雨资料建立降雨-径流相关图,推求流域的瞬时单位线,拟合洪水。结果表明,数字滤波法分割的基流比斜割法更平滑,更符合流量过程线退水段的物理规律,且其获得的瞬时单位线的确定性系数较斜割法高。

The base flow is an important part of the river and the correctness of base flow separation directly affects the hydrological analysis of basin, such as watershed rainfall-runoff relationship, overland flow and others. The modified digital filtering method and beeline method are applied to separate total runoff of a flood event respectively, and then the rainfall-runoff correlation diagram is established to calculate watershed instantaneous unit hydrograph and fit the flood based on separated surface runoff and rainfall data. The results show that the base flow separated by using digital filtering method is smoother than beeline method and more in line with the laws of physics hydrograph recession, and the certainty coefficient of the instantaneous unit hydrograph deduced from the result of digital filtering method is higher than that of beeline method.