摘要
基流可以反映流域地下水的变化过程,是研究流域水量平衡、地下水对气候变化与人类活动响应及预测的关键因子,因此选择合适的基流分离方法对研究流域内地下水变化特征有着重要的意义.本文基于秦淮河流域武定门闸实测逐日流量数据,选用数字滤波法、基流指数法(BFI)和HYSEP法3类6种基流分割法对流量的基流部分进行了分离.结果表明:6种方法均可以实现对基流的自动分割,方法较为简便,可以克服人工法的主观性,但是得到的基流过程线却有一定差异.HYSEP法中固定步长法和滑动步长法分割出的基流过程基本没有反映出汛期径流随地下水流动过程消退的现象,与径流曲线的变化情况对应较差;BFI法虽能够实现对地下径流的自动分割,但是不能很好地反映真实的产汇流规律;而数字滤波法和局部最小值法得到的基流过程线更为平滑,更加符合水文气象学中降雨-径流在流域汇流时的阻尼和迟滞效应.总之,从极值比、变幅和基流过程变化而言,数字滤波法标准差较小,分割结果较为稳定,且其基流分割过程线更加合理,是6种方法中较为可靠的分割方法,更适用于秦淮河流域的基流分割.运用数字滤波法对秦淮河流域近十年基流进行分析,结果表明,流域的年基流指数均大于0.35且呈现增长趋势.
The base flow is a key factor to study the water balance. The response and prediction of groundwater to climate change and human activities could reflect the change process of groundwater in the basin. Therefore, choosing a appropriate base flow separation method has great significance to study the characteristics of groundwater changes in the basin. Based on the measured daily flow data of Wuding River Gate in Qinhuai River Basin, six kinds of basic flow segmentation methods have been chosen in this paper: digital filtering method, base flow index method (BFI) and HYSEP method to separate the basic flow. The results show that the six methods can realize the automatic segmentation of the base flow, which is simple and can overcome the subjectivity of the artificial method, but the process has some differences. Fixed step and the sliding step method in the HYSEP basically does not reflect the phenomenon that the runoff in the flood season subsides with the groundwater process, and corresponds to the change of the runoff curve;The BFI can achieve the subsurface runoff automatic segmentation, However, this method does not reflect the true law of production and sink flow;We found the basic flow process lines obtained by the digital filter and the local minimum method are smooth. The digital filtering method has a smaller standard deviation, the segmentation result is more stable and reasonable. Compared with other methods, it is more suitable for the base flow segmentation in Qinhuai River Basin. The results show that the annual base flow index of the watershed was greater than 0.35 and has an increasing trend.
作者
郝璐
李素雲
孙磊
方荻
秦孟晟
HAO Lu;LI Su-yun;SUN Lei;FANG Di;QIN Meng-sheng(College of Applied Meteorology/Key Laboratory of Agricultural Meteorology in Jiangsu, Nanjing University of Information Science and Technology, Nanjing 210044, China;Yangzhong Meteorological Bureau, Zhenjiang Jiangsu 212213, China)
出处
《西南师范大学学报（自然科学版）》
CAS
北大核心
2019年第1期62-69,共8页
Journal of Southwest China Normal University(Natural Science Edition)
基金
国家自然科学基金项目(41571026
41877151)
南京信息工程大学大学生实践创新训练计划项目(201710300135)
