Integration of multiple hydrogeological survey technologies for exploring the groundwater distribution in karst areas: A case study in Xingfu Spring, Chaohu City, China

Exploring the developing characteristics and spatial distribution of fractures and conduits in the karst system is of great significance for utilizing groundwater resources and preventing geological disasters. This study took the field of Xingfu Spring, Chaohu City, China as a target zone, three geophysical methods including MALM, TEM, and ERT were used to disclose the distribution regulation of the karst system. Based on the geophysical methods results, a hydrogeological borehole with a depth of 24.4 m was constructed to observe the structure of stratum. Then, the point velocity probe (PVP) technique was used to reveal the structure characteristics of stratum in borehole and measure the flow velocity and direction of the karst system. Finally, the tracer test was carried out in the borehole to explore the connection between borehole area and spring system. The main results show: (1) the extension direction of the karst cave in borehole is about 20 degrees west by south and the direction of spring water flow path is about 30 degrees north by east; (2) the groundwater in this karst cave and spring water flow path system has a similar flow direction, roughly from northeast to west; (3) there is no direct hydraulic connection between the borehole area and the spring water flow path based on the result of the tracer test. In this paper, the spatial distribution of groundwater in the study area has been successfully revealed based on the ensemble hydro -geological survey technologies. The good application of the integrated geophysical method and PVP technique can provide the reliable technology means for researching the spatial distribution and development regulation of groundwater in karst system.