Direct current (DC) resistivity soundings with Schlumberger arrays are utilized to map the vertical and horizontal distributions of resistivity in the area between the Pachang-chi and Tsengwen-chi, southern Taiwan. This makes it possible to map the paleo depo-and hydro-environment of the study area. In addition, the transverse resistance computed form the field sounding data measured near the walls can be related to the transmissivity measured directly within the wells. An empirical relation between the tranverse resistance and transmissivity could thus be derived. The hydraulic parameters at the DC sounding locations without any well information could still be estimated from such empirical relationships. Thus, the locations of fresh groundwater zones and the most promising sites for future drilling could be determined.