F.R. Hasan Muhammad, Susilo Adi, Sunaryo
The drought has become one of the major problems of society; it can be overcome when an area has groundwater resources. This research has been taken at the Karst area of Druju Village, Sumbermanjing Wetan Subdistrict, Malang District. The purpose of this research is to identify the underground river flow pattern and the relation between the Wonorejo well and the spring water at Kaligoro River. The method used is Self Potential (SP), Leap Frog configuration with 104 measurement points and resistivity method, dipole-dipole configuration with seven measurement lines. The contour maps indicate that the value of the SP ranged from 0 to 13.5 mV, assuming a low potential value (0-1 mV) is an indication of underground water. In addition, the resistivity value ranges from 1.7 to 29485 Ωm with the rocks as clay stone (1.7-112 Ωm), sandy marl (113-1818 Ωm) and carbonate/limestone rock (1819-29482 Ωm). The indication of the presence of groundwater (underground river) is indicated by the depth of the carbonate rock suspected to be the scouring process by water and this is also supported by the low potential (SP) value of the area. The existence of underground rivers is detected on line 1 and 2 at depths of 23.6 and 35 meters and line 6 on the surface. The underground river flows from line 2 to line 1, or the North-West direction and it is possibly end up to the Lesti River in the Northern area of the study site while the existence of spring that appears around the Kaligoro River does not have correlation with Wonorejo well. Copyright © 2018 The Authors, some rights reserved.
Department of Physics, Faculty of Mathematics and Natural Sciences, Brawijaya University, Indonesia; Department of Geophysics Engineering, Faculty of Mathematics and Natural Sciences, Brawijaya University, Indonesia
