DETECTION OF GROUNDWATER CONDUITS BY INTEGRATED GEOPHYSICAL METHODS

When an intake or an outfall of a shallow buried groundwater conduit exists, it is a simple, direct and fast way to trace its direction with the mise-a-la-masse method, even though the charging current position is needed. The selfpotential method is good at buried underground flow prospecting, but with too much noise and low resolution. Although lacking for detecting the spatial distribution of groundwater conduits, both mise-a-la-masse and self-potential methods can estimate anomalous features. High density resistivity method can obtain detailed spatial resistivity distribution near the surface. It is wise to introduce shallow seismic reflection method to the exploration of buried groundwater conduits controlled by faults. In case of limited surveying site, great prospecting depth and demanded high resolution, the crosshole electromagnetic wave-penetrating method is suggested in prospecting. However, high density resistivity, shallow seismic reflection and cross-hole electromagnetic wave-penetrating methods cannot give qualitative results to the anomalies. With prospecting examples, this paper shows how the optimum combination of prospecting methods is selected in the detecting of groundwater conduits and defining of the anomalous features and spatial distributions in different geological conditions and prospecting costs.