Isotopes and hydrochemistry of Daihai Lake recharging sources, Northern China

Daihai Lake has faced severe shrinkage in recent years due to over-exploitation. Stable isotopes (D and 18 O) and hydrochemistry are employed to investigate the source of lake water to better understand its recharge dynamics. Results show that, in additional to local rainfall, groundwater is also an important water supply to the lake and accounts for a greater proportion. The groundwater is not recharged by local rainfall, but originates from other sources with significantly depleted isotope values. Combined with springs and artesian wells in the basin, it is consistent with the recent discover of external groundwater recharging in Northern China.