Application of the frequency-domain airborne electromagnetic method in shallow (brackish) saline water and freshwater surveys in the Xiong'an New Area

Determining the boundary between shallow saline water and freshwater in areas containing (brackish) saline water can guide the exploitation and utilization of local shallow water resources. This study analyzed the characteristics of underground shallow electrical structure through inversion based on the frequency-domain airborne electromagnetic data. Then, it inferred the boundary between the shallow (brackish) saline water and freshwater in the study area. By comparison with the boundaries between saline water and freshwater obtained from two hydrological surveys in 1998 and 1999 and by combining the surface hydrogeological data, this study revealed that the shallow groundwater cones of depression affect saline water intrusion trends in the Xiong’an New Area, and the details are as follows: The (brackish) saline water intrusion in the Zangang-Mijiawu-Shuangtang area in the northeast of Xiongxian County tends to be stable due to the presence of the Zangang groundwater cone of depression. However, this cone has also intensified the (brackish) saline water intrusion in southern Zangang Town. Compared to 1999, the (brackish) saline water range on the west side of Anxin County has continuously decreased due to the rise in the water level of the Rongcheng groundwater cone of depression. The continuous decrease in the water level of the Gaoyang groundwater cone of depression determines that the (brackish) saline water range in the Luzhuang-Gaoyang direction will continuously expand. These predicted (brackish) saline water intrusion trends will provide data support for the rational exploitation and utilization of water resources in the construction of the Xiong'an New Area.