五种基流分割方法在长江螺山站的应用对比研究

基流是枯水期河川径流的主要来源,稳定可靠的基流分割方法对基流研究具有重要作用。基于螺山站1965-2012年逐日流量资料,采用基流指数法、HYSEP法(固定步长法、滑动步长法、局部最小值法)和数字滤波法3类(5种)基流分割方法进行基流分割。研究结果表明:5种方法所得年基流指数相差不大,但年内基流过程差别显著。BFI法和局部最小值法计算结果较为合理,对不同年份BFI值年际变化有较好的辨识度,是长江中游干流区较为适宜的基流分割手段。

Applied comparison of five separation methods of base flow at Luoshan station of Yangtze River

Base flow is the main source of river in dry season.The stable and reliable method of base flow separation is of importance to base flow research. Based on the daily discharge data of Luoshan station from 1965 to 2012,the paper used five methods which include the base flow index method, fixed interval method, sliding interval method, local minimum method and digital filtering method to separate the base flow. The results show that there are little differences among five methods, but the base flow process varied significantly between the five methods in a year. The results of BFI method and local minimum method are more reasonable and have better identification in different years.The method is a suitable mean of base flow separation in the middle area of the Yangtze River.