黄河源区基流估算

Baseflow estimation of the source regions of the Yellow River

河川基流在水安全、粮食安全、非点源污染评价、水资源评价和调查、水资源配置、工农业供水和降雨-径流关系模拟中有着重要的应用。黄河源区(唐乃亥水文站以上区域)的产水量占黄河流域的35%以上,是黄河流域的重要产水区,对黄河源区基流的估算就显得尤为重要。根据研究区域的气候特征,对加里宁法在本区域的应用提出了改进,并提出了新的计算程序。在此基础上,和电子滤波法进行了对比分析。结果表明,电子滤波法非常敏感,滤波参数β控制了基流在总径流中的比例,β与基流成负相关关系,对于不同的来水年份,其敏感性分析图形的形态都很相似;改进的加里宁法基流划分过程强烈地依赖于日过程线的起伏情况,基流一般随着退水系数的增加而增大,加里宁法分割的基流对于参数的变化并不敏感。

Baseflow plays an important role in water security, food security, water resource assessment and investigation, and water allocation. Baseflow is mainly the recharges from groundwater. The characteristics of recharge and discharge of groundwater are very im- portant to efficient groundwater management and sustainable development, and are vital to the control of pollution. Runoff of the source regions of the Yellow River accounts for more than 35% of the total ruhoff of the Yellow River basin. Baseflow is a very important water supply source in the low flow season and also an important supply cource in the headwaters, hence, it＇s essential to estimate baseflow in this area. There are numerous baseflow separation methods such as analytic methods and graphic methods, but they have their own shortcomings and can＇t be applied extensively. In this study, two physically based and two parameters based baseflow separation methods -Kalinin method and digit- al filiter method - were selected. First the Kalinin baseflow separation method was improved based on the climate condition of the study area and a new procedure was developed and then the sensitivity analysis was conducted for the two methods. The results show that the baseflow separated by digital filter baseflow separation method is very sensitive to the parameters variation, and the filter parameter β is the control factors of the baseflow. With the increase of β the separated baseflow decreases and vice versa. The sensitivity analysis curves are very alike as to the runoff of different years. The baseflow separated by the modified Kalinin method is strongly affected by the runoff hydrograph, generally, the baseflow increases with the increase of recession coefficient and is not sensitive to the variation of parameters.