A fault estimation has been done in Pohgajih village, Selorejo subdistrict, Blitar district, Indonesia using geoelectric resistivity, dipole-dipole configuration. The study was conducted using Resistivity meter OYO MacOHm. This study aims to analyze the existing fault track at the study site. The analysis of the fault is expected to provide information on the impact of the settlement of villagers in Pohgajih Village. The data acquisition is performed on five measurement tracks with a track length of 150 meters. Visual surveys show that in Pohgajih Village, there are points where people's homes are fractured and severely damaged, and a slanted electric pole as the ground continues to move every year. Based on the interpretation of the resistivity data and the correlation with the visual survey results, the cracked and severely damaged house points were in the low resistivity range. The resistivity varies from 3.4 to 9.8 Ω.m and interpreted as clay. If traced based on the interpretation of resistivity data and visual surveys then it can be assumed that there is an additional fault, in addition to one track already contained on the geological map. The first fault corresponds to geological information based on the Blitar Sheet Geology Map. However, with the presence of severe damage dwellings at other locations, it is suspected that a second fault is located in the northern part of the first fault. Both faults lead from Northwest to Southeast and are suspected as strike slip fault.

ABSTRACT:Research on landslide in Sri Mulyo Village, Dampit Subdistrict, Malang District, Indonesia has been implemented. This research is conducted to know the condition of the subsurface area for information in landslide vulnerability analysis. In addition, this research was undertaken to mitigate landslide in minimizing casualties and material losses. The study was done using resistivity method, configuration of dipole-dipole supported by drilling core lab test result. There are five resistivity measuring lines with trajectory lengths ranging from 100 m, 200 meters, and 300 meters. The results of the resistivity indicate that the subsurface lithology of Sri Mulyo Village is composed of clays (9.3-85.8 Ω.m), tuff (178-779 Ω.m) and breccia (≥ 1629 Ω.m). The sliding plane at the research area is the boundary between clays and tuffs. The result of correlation between geoelectric and drilling core data showed that the research area was dominated by a 10m depth of clay. High rainfall, clay thickness and vegetation (coffee) exhibit high levels of vulnerability to occur landslides. Possible landslide direction is from West-West to Southeast with creep avalanche type.

PurposeResearch has been conducted to analyze the landslide in Banaran area, Ponorogo Regency. The landslides occurred on April 1, 2017. This study was conducted to know the subsurface conditions in the Banaran area to analyze the disaster mitigation efforts. The mitigation efforts are made to reduce the risk from landslides and possible landslides.Design/methodology/approachThe method used is the geo-electric resistivity method of Wenner–Schlumberger configuration. The research was conducted in three villages namely Banaran Village, Bekirang Village and Mendak Village.FindingsThere are 12 resistivity measuring points with a track length of 410 m and a space of 10 m. The measured resistivity range is between 1.42 Ω.m and 67.500 Ω.m. The resistivity data and the local geological maps interpreted that the rocks in the Banaran area consist of clay, tuff lapilli, volcanic breccia and andesite lava. The landslide area begins at a depth of 8–35 m below the surface which is interpreted as tuff. Also, the thickness of the landslide material and the slope is = 400 which supports the occurrence of a more prominent landslide. The results of the parameter scoring of the landslide-prone areas indicated that the research area is very vulnerable to a landslide. The results of the interpretation indicate that the geo-electric resistivity method can provide a good overview for conducting landslide analysis, that is field slippage and potential material thickness occurrence landslide.Originality/valueThis article is very specific as it attempts to discover how prone Banaran are is to landslide.

We identified the craked zones based on geoelectrical resistivity method in Sutami Dam. There are four lines measurement of geoelectrical resistivity method with a length of 380-400 meters. The direction of each line is from the northeast to the southwest. All of the tracks are located at the top of Sutami Dam i.e. two tracks in the upstream and the others in the downstream<em>. </em>From the analysis we found that the lithology is detected by geoelectrical resistivty method showed two layers of design of Sutami Dam. The two layers that are detected are transition zone and filter zone. Transition zone consists of sandstone rock containing water (0.922 Ωm-9.57 Ωm) and dry sandstone (&gt;9.57 Ωm-320 Ωm). Filter zone consists of sand (&gt;320 Ωm-4410 Ωm). Cracked zones spread in the upstream, downstream, and roadway at the top of Sutami Dam which are indicated by the presence of low resistivity (0.922 Ωm-9.57 Ωm) based on 3D processing of data of geoelectrical resistivity. The distribution of cracked zone indicates that Sutami Dam is susceptible to ground movement.