Seepage Zone Identification at Sutami Dam by Means of Geoelectrical Resistivity Data

Abstract

A study with entitled Seepage Zone Identification At Sutami Dam By Means Of Geoelectrical Resistivity Data has been conducted. The aim of this study is to get the distribution of seepage zones in the Sutami dam body. Data acquisition has been done by using Oyo-EL McOhm Model 2119C equipment on the tracks along the side of the dam body, both downstream (exhaust) side for first and upstream (reservoir) side for second with pseudodepth section dipole-dipole configuration. Each track has a length of 400m and 380m respectively. The distance between the point electrode consists of 1 track with space (a) is 10m (n=8) and 3 tracks with a space (a) is 20m (n=8). Based on the results of data processing obtained are low resistivity values (ρ ≤ 9.57 Ωm), the moderate resistivity value (9.57 Ωm < ρ ≤ 320 Ωm), and high resistivity (ρ > 320 Ωm). The distribution of fracture zones associated with seepage zones for Sutami dam distributed over the surface to depth of 8-18 m, both upstream (reservoir) or downstream (exhaust) indicated by resistivity values 0.922 Ωm to 9.57 Ωm. The results of the 3D data processing indicates that the fracture zone is also distributed between the upstream (reservoir) and downstream (exhaust) of the Sutami dam body.