基于长序列实测日径流资料,分析了无定河流域的地下水补给-排泄关系。结果表明:①流域多年平均地下水补给量为11.38~15.69 mm,降水入渗补给系数为2.9%~4.4%,基流补给率约为73.6%~86.8%;②就三个分区而言,年均地下水补给模数、降水入渗系数以黄土区最大,河源区次之,风沙区最小;而基流补给率以河源区最大,黄土区次之,风沙区最小;③趋势分析表明,研究区地下水补给量总体呈显著减少趋势,并进一步导致了基流量的减少。但是基流的减少程度高于补给量。

The Wuding River Basin, which is one of the biggest catchments in the Loess Plateau, is dry and lack of water resources. In this paper, recharge-discharge relationship in the basin has been investigated using the daily streamflow records since the 1950s. It was estimated that the annual recharge of the basin varied from 11.38 mm to 15.69 mm. For different sub-catchments the ratio between recharge and precipitation ranged in 2.9%-4.7%, while the ratio between recharge and baseflow was 73.5%-86.8%. Baseflow is highly correlated with recharge. Spatially, the loess area has the largest recharge and recharge-precipitation ratio and the headwater area has the largest recharge-baseflow ratio, while the sandy area has the smallest. Temporally, groundwater recharge has decreased significantly, which consequently resulted at the significant reduction of baseflow. However, the decrease rate of baseflow is larger than recharge indicating the impacts of human activities like groundwater withdrawing.