Study region
Chahannaoer Lake, the largest inland saline lake in northern China, is vital for biodiversity conservation but has been dried-up in recent years.
Study focus
This study aimed to identify lacustrine groundwater discharge (LGD) differences between two small perennial lakes on the western (XHZ) and eastern (HHZ) sides of Chahannaoer Lake and the internal LGD spatial variability within each lake. A comprehensive approach was used by combining 222Rn model, water balance model and water chemistry.
New hydrological insights for the region
Significant spatial variability of 222Rn was observed in both lakes, increasing with increased distance from Chahannaoer Lake, and consistent with distributions of total nitrogen, total organic carbon, and chlorophyll-a. Average LGD rates were 18.7 mm/d for XHZ and 7.3 mm/d for HHZ, respectively. The difference in LGD rates could be attributed to geological structural influences that enhance connectivity and groundwater flow, as well as groundwater interception leading to internal differences in LGD rates of each lake. Findings from this study indicate that hydrogeological conditions in the northwest of the Chahannaoer Lake are favorable for greater water influx to the lake. Consequently, it is recommended to prioritize ecological restoration efforts in the northwest of the lake. This study can improve our understanding of LGD in lake groups adjacent to large lakes in arid regions and can inform water resource management and ecological restoration.