Adi Susilo, Sunaryo, Alexander T. Sutanhaji, Fina Fitriah, Muhammad F. R. Hasan
Research has been done in Karst area, Druju Village, Sumbermanjing Wetan Sub District, South Malang. The study was conducted to map underground river flow in the karst area to reduce the impact of drought during the dry season. The method used is geoelectric resistivity, dipole-dipole configuration and self-potential methods. There are 3 line of data retrieval resistivity and 34 data points of self-potential. Based on the results of geoelectric measurement, it can be seen that the subsurface resistivity of the study sites ranged from 4.64 to 2696 Om, with the interpretation of rocks beneath the surface were claystone insertions, sandy marl and limestone. The results of the geoelectric resistivity method indicate that there is an anomaly at a depth of 13.6 meters in line 1, and 18.4 meters in line 2 and 3 respectively. The anomaly indicates that the layer is supposed to be a layer of carbonate rock (limestone), but because of the underground river flow, the carbonate rocks are crushed and form a cavity which is then filled with the sandy marl. Sandy marl trapped inside the cavity are the ones that serve as underground river streams in the study sites. This is supported by the low Self Potential value (-1 to 0 mV), which is on the resistivity line. Low Self Potential values indicate the presence of water beneath the surface. The correlation between the two methods suggests that the river flow direction may be from southeast to northwest (North-West) and ends to the Lesti River located in the northern part of the study site. © Research India Publications.
Faculty of Sciences, Universitas Brawijya, Indonesia; Faculty of Agricultural Technology, Universitas Brawijya, Indonesia
