Using chloride mass-balance and stream hydrographs to estimate groundwater recharge in the Hailiutu River Basin, NW China

Groundwater plays a key role in arid regions as the majority of water is supplied by groundwater. Therefore, estimation of groundwater recharge is a key issue for groundwater development and management. In this study, the chloride mass-balance (CMB) method and the stream hydrograph separation method were used to quantify groundwater recharge in the Hailiutu River Basin. The results show that groundwater recharge estimated by the CMB is 89 mm/yr, which is similar to groundwater recharge estimated by the stream hydrograph separation method (78 - 82 mm/yr). The difference between the two methods may result from riparian vegetation transpiring water directly from the groundwater. The study indicates that the CMB method can produce reliable regional groundwater recharge. The results of the study can be used to make effective schemes of the groundwater management and development.