Joint evaluation of gravity and geo‐electric methods for groundwater exploration in western ZZ area

Abstract

Summary: The western ZZ area, which lies in the northwest Huabei plain, was the most well-known area in Huabei for its abounding groundwater. During the past several years, the water table has been dropping year by year due to overuse of the surface water upriver and overexploitation of the groundwater. As a result, most wells in this area have dried up and some of the residential areas are at risk of not having drinking and irrigation water. Some geophysical prospecting has been carried out in this area and several boreholes, which were funded by the local government, have been drilled based on the geophysical results. But most wells have not found a good aquifer. In order to map the good aquifers and solve the water supply problem, a third geophysical ground exploration with joint evaluation of gravity and geo-electric methods was conducted. During the exploration, the former drilling results and geological information has been carefully studied by the survey group. Based on these, the target aquifer stratum was locked in calcareous rocks in this area. Five boreholes have been designed based on the geophysical results and three of them have been drilled and met good aquifers. The result indicates that good aquifers in the western ZZ area feature high density and resistance. This is different from most aquifers outside this area.