Magnetic resonance sounding evidence shows that shallow groundwater discharge maintains the lake landscape in the Hunshandake Sandy Land, North China

摘要

The Hunshandake Sandy Land (HSL) is a well-known water-rich sandy region in China that is home to many lakes. Most of these lakes are sustained by groundwater inflow. However, due to the limited hydrogeological survey data, the mechanism by which the lakes interact with groundwater is not well understood. Magnetic resonance sounding (MRS) is a geophysical method that has emerged in recent years that can directly detect the distribution of groundwater and determine the lithology of the aquifer medium. Compared with drilling, this method is convenient, rapid, and inexpensive. In this study, to determine how the lakes are recharged by groundwater, a field experiment using MRS was conducted on Haoletuyin Lake, which is located in the central HSL. The results showed that compared with borehole data, the MRS-derived aquifer depth has an uncertainty of 6.88%. Additionally, the lithology of the media derived from the MRS is consistent with that derived from the borehole data. This finding suggests that the MRS-derived results are highly accurate. Based on the MRS-derived results, two hydrogeological profiles were plotted, and they show that the lake in the experimental area is recharged primarily by shallow groundwater and not by deep groundwater. This study is significant because it not only reveals the mechanism by which Haoletuyin Lake is maintained, but also proves that MRS is an excellent tool for studying lake-groundwater relations in desert (sandy land) regions with limited hydrogeological survey data.