The Institute of Karst Geology Makes a Breakthrough in Search of Water with New Geophysical Prospecting Technology in Sichuan Red Formation Area
Institute of Karst Geology, Chinese Academy of Geological Sciences (hereinafter
referred to as the Institute of Karst Geology) has been working on the
geophysical prospecting subject of Hydrogeological
Environment Survey of Wumeng Mountain Area, and made a breakthrough in
search of water with combination of high-density electrical survey and
microtreme survey in red formation (Jurassic-Cretaceous continental sand shale
formation) area in Pingshan County,Sichuan Province.
Pingshan County is located in the mountainous area at the southern edge of Sichuan Basin, and borders Yunnan Province and Guizhou Province. It is a typical red formation area where water is hard to be found by digging wells.
On the apparent resistivity profile gained by high-density electrical survey, zones rich in underground water are reflected by 'V', 'U' and 'ㄩ' shaped low resistivity zone. The area with sparsely distributed contours in low resistivity anomaly zone indicates broken karst or fracture developed section. The shape of apparent resistivity curve reflects depth and thickness of broken aquifer. Microtreme survey can predict water-bearing property of underground geological structure through analysis of H/V characteristic frequency and spectrum shape.
Electrical survey and microtreme survey are combined to determine favorable hole sites. The artesian well in No.2 Group of Zhonghe Village, Taiping Town, Pingshan County ends the long-term lack of water with daily water yield of 1600 tons per day. The well in Datian Group, Pingyi Village, Yachi Town, Pingshan County has daily water yield of 196 tons per day and greatly alleviate the shortage of drinking water for over 4000 local people.