Ziming Wang - Yunnan Institute Co.,Ltd of Water & Hydropower Engineering Investigation Design. Kunming 650021,China
In order to rationally develop and utilize groundwater resources and give full play to their resourceadvantages, it is necessary to carry out the exploration of groundwater resources. Due to the strongdissolution in karst areas, the development of karst landforms, atmospheric precipitation is easy topenetrate into groundwater, and the lack of surface water causes drought, so finding groundwater hasbecome an important problem faced by karst areas.In this study, the dam axis of a dam site in HuapingCounty, Lijiang City was investigated using the induced polarization method. The application ofpolarization rate and half-life as characteristic parameters was introduced to determine the undergroundwater level, karst development, and fault structure in karst regions. To improve the reliability of the surveyresults and reduce interference from complex geological conditions, a method of differentiating theresistivity curve through approximation with a 6th-degree polynomial or a logarithmic polynomial wasproposed. The method was validated using drilling data in combination with previous geological surveydata, and the results of graphical analysis and interpretation of multiple parameters were used todetermine the underground water level, karst development, and fault structure in the dam axis explorationarea. The results indicate that the excitation polarization method is an effective means to find groundwaterin karst areas, and the changes of apparent resistivity, polarizability and half-decay are closely related tothe enrichment, karst development and fault structure of groundwater,the method of differentiating theresistivity curve through approximation with a logarithmic polynomial is more effective than approximationwith a 6th-degree polynomial in the investigation of dam sites.The search for groundwater, karstdevelopment, and fault tectonics in future karst areas provides new ways to process data.At the sametime, improving the efficiency and accuracy of welling.The structural map and measuring point layout ofthe exploration area are shown in Fig.1.