Application of audio magnetotelluric sounding to the seawater intrusion survey of Jinzhou

The invasion of sea and salt water in big and small Linghe region of Jinzhou City has seriously affected the local economy and people's quality of life. In order to find out the boundary change and pollution scope of the sea and salt water in the study area, five AMT profiles have been completed. The profile data is inversed by the improved NLCG method. The two-dimensional inversion results directly reflect the distribution range of the salt and fresh water in the study area, and give the boundary location of the salt and fresh water. The results show that the transgressive range of L0 and L1 profile does not expand, the transgressive range of L2 profile is expanding, part of fresh water has been polluted by the underground ancient saline water at L3 profile, and the fresh water is not polluted at L4 profile, which are basically consistent with the hydrogeological drilling and mechanical well survey data. In a word, AMT method is feasible and effective to study the occurrence state and change rule of sea and salt water in the Jinzhou area, which can provide basic geophycical data for environmental hydrogeology investigation.