结合退水曲线的数字滤波基流分割方法
Digital filter baseflow separation method based on a master recession curve

基流分割在水文、水资源及水生态环境等领域有重要作用。该文在比较几种常用的基流分割方法的基础上，提出结合退水曲线的数字滤波基流分割方法，解决数字滤波方法参数不确定的问题，并在中国怒江流域应用。结果表明：数字滤波方法相对基流指数法（baseflow index，BFI）和时间步长法（hydrograph separation program，HYSEP）能够得到平滑的基流过程，但是其对参数敏感；通过对退水曲线分析可以确定数字滤波参数，并得到合理的基流过程。这种结合退水曲线的数字滤波基流分割方法在怒江流域的应用表明：怒江流域5个水文站多年平均基流指数在0.39~0.55之间，基流指数的年际变化较小。
Abstract：Baseflow separation is essential in hydrology, water resources and water ecology. This study compares several baseflow separation methods with a digital filter baseflow separation method based on a master recession curve then developed to reduce the parameter uncertainty. A study of the Nu river in China shows that this digital filter method gives smoother baseflows than the BFI method and the HYSEP method; however, it is sensitive to model the parameters. Reasonable baseflows were obtained by using a recession curve to determine the digital filter parameters. The results show that the baseflow in the Nu River accounts for 39 to 55 percent of the total runoff in different sub-basins and that the inter-annual variation of the baseflow is relatively small.