Comprehensive geophysical model for water prospecting in fault fracture zone:A case study of water supply well siting at Gantianba village

There is a serious shortage of water resources in the poverty-stricken areas of Wumengshan.On one hand, the demand for water supply is large and on the other hand it is difficult to locate the water sources. In this study, the aquifer environmental factors,water-bearing property and geophysical characteristics were comprehensive analyzed. As a result, borehole ZK12 was sited incorporating with the the analysis of fault zone,and the application of the methods including ground resistivity profile, magnetotelluric sounding, transient electromagnetics , IP sounding and geophysical well logging,etc. The geophysical characteristics for determining fault conductive zone was hence conducted by using the geophysical parameters such as apparent resistivity, apparent polarizability, attenuation, half-life failure, apparent visual metal factor, deviation degree, excitation ratio and etc. from which multiple level geophysical model was established. In this paper, we innovatively put forward the "multi-method, multi-parameter and multi-level" geophysical exploration method for locating critical water bearing zones for the resource demand from key villages and towns in Wumengshan with contiguous poverty and water-shortage ,and overcome the limitations of a single geophysical exploration technique in locating the resources and accurate borehole siting. Through examining borehole logging data, it is confirmed that the multiple-method geophysical exploration approach can effectively determine the depth of strata and water-bearing faults, provide experiences for the geophysical exploration for water exploration, as well as play a demonstration role in groundwater exploration.