Application of the DC resistivity method in urban geological problems of karstic areas
Terminating industrial activities may have harmful side effects on the infrastructure of a civil society. One effective method of solving environmental and geotechnical problems in urban areas is a direct-current resistivity survey. In karstic areas, largescale geological structures directly affect the near-surface, small-scale events. Reliable data on the geological background of harmful events are acquired through suitable combinations of large-scale and of small-scale high-resolution surveys. In this study, the geological background of three urban subsurface-related problems was investigated in a karstic area: collapse of a sinkhole, suffusion of a basement area, and contamination of an urban creek. In each case, the scientific work aimed at setting up of a suitable model that describes the harmful event and its geological background. For this purpose, a combination of large-scale and high-resolution resistivity data was acquired and augmented by borehole information and laboratory analyses. The error analyses of the resulting models suggest that the methodology of dual-scale geoelectric investigation of urban hazards in karstic areas can provide applicable models for mitigation measures.