Abstract
1991 Mt. Pinatubo eruption has caused changes of groundwater in Mt. Pinatubo area. A simple and valid method is demanded to estimate groundwater level for the development of shallow well irrigation system. HIRAIDE et al. (2001) reported that electrical exploration could be applied to investigate groundwater in Pasig-Potrero river area. This study aims to discuss the evaluation of electrical prospecting 1D method (ρ-a method) for a feasible groundwater exploration method. Boring and measurement of groundwater level were performed to verify the precision of groundwater estimation by electrical prospecting 1D method.
The results obtained in this study are summarized as follows.
1) Boring investigation proved that one dimension sounding (ρ-a method) was able to estimate geological stratum and groundwater level.
2) Repeating measurement conducted in the same site revealed that exploration results from one dimension sounding were reproducible regardless of rainfall.
3) From the comparison of analytical data for both wet and dry season, it is clarified that electrical prospecting 1D method. is precise enough to use in full season as a practical method for estimating groundwater level. The accuracy of estimated groundwater level was obtained as 1.1-1.2m
