Resistivity method is very suitable for groundwater exploration. Two methods can be used, the surface method and crosshole method. Surface method is cost effective, though it is sometime not as accurate as the crosshole method. Geologists usually narrow down the exploration area and then operators can use geophysical methods to find groundwater.
Surface method involves laying two cables on the grounds with pegs in the ground connects with the cables. The FlashRES system will then inject current to the ground and measure the potentials. Crosshole method involves the use of two cables by putting each cables in one borehole respectively to measure the MN potential between these two cables.