The practice and understanding of the electrical exploration to seek groundwater in limestone area invaded by igneous rocks

The groundwater distribution is uneven and water resources are very lack in the Taihang Mountain area with limestone invaded by igneous rocks.The success ratio is low in drilling well.In order to reasonably develop groundwater resource,the three electrical exploration lines were arranged in the direction perpendicular to main geology structures based on the hydrogeological investigation in the working site.The apparent resistivity values were observed by means of the resistivity sounding with the symmetric quadrupole along the lines.Through draw-ing the iso-apparent resistivity sectional map,the anomaly modality of groundwater-enriched zones was analyzed and interpreted on the map.Drafted well position was selected.Drilling engineering showed that the well yield was large and geophysical exploration method was effective.It is pointed out that the investigation of hydrogeology is foundation,working arrangement should be flexible and deepened analysis and interpretation of anomaly modality are key for seeking groundwater in this kind of area.