Groundwater Investigation in Hard Rock Using Remote Sensing and Geophysical Methods in an Area of Economical Trees Plantation, Western Songkhla Lake

Abstract

Groundwater in hard rock areas has become increasingly important due to increasing of population, expanding of the city and the industrial sector etc. It is relatively safe from pollution, unlike surface water and shallow groundwater. Remote sensing and geophysical methods have been used for groundwater investigation in hard rock area, Khao Phra sub district, Rattaphum district, western Songkhla Lake. The groundwater will then be used for plantation and consumption. The interpretation of digital elevation model data (DEM) provides the possible lineaments indicating faults or fractures in the subsurface which possibly related to groundwater trapped in hard rock. Three dominant lineaments around the foothill of Khao Keaw Mountain were suggested and 8 profiles with perpendicular to the lineaments were defined to perform ground geophysics surveys. Schlumberger VES suggested that there is a fault locating between the VES measuring positions which locate at the opposite side of lineament. Reflection seismic and resistivity pseudosection data give a topography variation of hard rock that indicates faults or fractures in hard rock. The exactly positions of faults or fractures have been confirmed by the VLF data and their positions will be recommended for drilling test well.