自动基流分割法在北洛河流域的适宜性对比

Comparison of Suitability Among Automatic Baseflow Separation Methods for Separating Baseflow in Beiluo River Basin

基流是枯水季节河川径流的重要补给来源,河川基流量及其变化对流域生态健康和水资源合理利用具有重要作用。确定适宜流域生态环境特点的基流分割法,在基流研究中是十分关键的工作。以北洛河流域上游典型黄土丘陵沟壑区刘家河站的多年实测径流资料为基础,分析BFI,HYSEP、数字滤波等三类共9种基流分割法的适宜性,结果表明：BFI法和HYSEP法分割结果比较接近,所得基流指数在0.399 4~0.428 1。尤其修正BFI法估算的基流量及过程线,能够客观反映研究流域流量过程线退水段的物理规律。综合考虑变异性、稳定性、过程线吻合程度等方面,认为修正BFI法是黄土区水文研究中进行基流分割的适宜方法。

Baseflow is an essential supply source of streamflow in the dry season. Its variability is very impor- tant for ecological health and water resources balance in a region. It is critical to identify a baseflow separa- ting method which is associated with the climatic and physiographic characteristics in the study region. Daily streamflow data at Liujiahe gauge station of Beiluo river basin, one of the catchment in the Middle reaches of Yellow River, were used to analyze the suitability of 9 tools in three types of baseflow separation methods of BFI, HYSEP and digital filtering. The results show that the base flow indices derived from BFI and HYSEP turn to be consistent, and they are all between0.399 4 and0.4 281. Particularly, the baseflow and thedura tion curve estimated by revised BFI can objectively reflect the recession hydrograph. The revised BFI is expected as the most suitable baseflow separation method for loess area in hydrological researches in terms of comprehensive consideration of the variability, stability and the process line of the results form 9 tools.