Using stable isotopes and major ions to investigate the interaction between shallow and deep groundwater in Baiyangdian Lake Watershed, North China Plain

In arid/semi-arid regions, consumption of deep groundwater resources is increasing due to growing water demand in every sector. Intensive groundwater surveys focused on the Baiyangdian Lake Watershed (BLW) in the northwest of the North China Plain, as the BLW suffers from serious water problems due to high economic growth and improper groundwater resource utilization. To clarify the interaction between shallow and deep groundwater, samples of surface water and groundwater in different aquifers were collected from two cities (Baoding City and Dingzhou City). Major trace element solute ion concentrations and stable isotopes of delta O-18 and delta H-2 revealed that, in a specific region of Baoding, anthropogenic activities have induced interaquifer recharge from Aquifer 1 to Aquifer 2 based on the similarity in chemical tracers. However, such an interaction could not be found in other regions in the study area.