Landslides are a common natural disaster in Indonesia, particularly in areas with steep slopes and high rainfall intensity. They can cause significant damage to property, loss of life, and disrupt the daily lives of affected communities. Bantul Regency is especially susceptible to landslides due to its geological structure and the tectonic activity resulting from the convergence of three major tectonic plates in the region. This research aimed to identify subsurface lithology and slip surface in the landslide-prone area of Selopamioro Village, Imogiri District, Bantul Regency, using the Wenner configuration resistivity geophysical method. Four measurement lines were conducted, each with a length of 225–240 meters and an electrode spacing of 15 meters. Data processing was performed using the Res2Dinv application to produce a two-dimensional resistivity model and RockWorks 17 for three-dimensional visualization. The modeling results revealed resistivity values ranging from 0.11 to 779 Ω·m, which were classified as sandy clay (0.11–44 Ω·m) and breccia (>44 Ω·m). The low resistivity zone indicated the presence of a wet sandy clay layer. The slip surface is estimated to be located at a depth of 20–30 meters below the surface, marked by a resistivity contrast boundary between the sandy clay layer and the fractured breccia. Local geological conditions, including volcanic breccia, rock fractures, and high rainfall infiltration, exacerbate the potential for slope instability.
Slope stability is influenced by many factors, including the subsurface structure, steep topography, rainfall intensity and human activities. The Metline landslide, located south of Metline city in northern Tunisia, was triggered following heavy precipitation and has caused significant damage to several constructions and public infrastructures such as the regional road, the Metline High School and many public housing. In this study, integrated geophysical and geotechnical investigations were conducted to characterize the landslide's geometry and internal structure, identify the sliding surface and lateral extent and investigate the main factors controlling its occurrence. In situ geotechnical monitoring and laboratory geotechnical tests have been carried out. The electrical resistivity tomography (ERT) technique was applied through three profiles acquired with the Wenner array configuration. The
Res2Dinv
software was used to process the resistivity data. The results of the geotechnical tests show that the water content varies between 15% and 35%. The Casagrande plasticity chart indicates that the subsoil is formed by two clayey horizons classified as medium to high plasticity clays. The inverted ERT models reveal two main geo‐electrical layers; the first one is a resistant layer characterized by resistivity values ranging between 12 and 95 Ω m. The second layer is a conductive layer with resistivity values lower than 8 Ω m. The correlation between the inverted resistivity models and borehole data enabled the identification of rupture surfaces located at depths between 5 and 10 m. The integrated interpretation further allowed for a more precise delineation of the landslide's lateral boundaries and the identification of the main conditioning factors controlling slope instability at the site.
Zaghdoudi Sabrine, Aydi Abdelwaheb, Sifi Sinda et al.· Near Surface Geophysics· 0 citations
Poguwatu Village in Central Sumba Regency is a dry area characterized by low rainfall and dominated by carbonate rocks, resulting in limited surface water availability and posing a persistent challenge for groundwater exploration. This study presents the first subsurface investigation using the Dipole-dipole resistivity geoelectrical method to characterize aquifer-bearing rock conducted in Poguwatu Village, West Cendana. This method has the ability to identify the conductor zone related to the saturation area where the water accumulated. Measurements were conducted along 5 survey lines, where each line has 620 m length, except Line 5 extending to 880 m, with 10 m electrode spacing. The measured data calculate in apparent resistivity value and then invert to true resistivity using least-square inversion processes. The result yielded RMS errors ranging from 17.7% to 24.8%. The inversion results identified four rock units based on resistivity values, sandy limestone saturated with saline water (< 2.0 Ωm), marl (2.0–32.0 Ωm), fractured or sandy limestone (32.0–128.0 Ωm), and compact limestone (>128.0 Ωm). A seepage with thickness ± 2 m was identified on Line 2 within the fractured/sandy limestone, bounded below by an impermeable marl. Compact limestone, with very low porosity and permeability, dominates in most of the study area and functions as an aquifuge, a finding corroborated by a dry borehole on Line 5 that failed to yield groundwater. These results indicate limited groundwater potential across Poguwatu Village, and further investigation into alternative water sources from surrounding areas is recommended for the community's water supply.
Aulia Nareswari, A. Paembonan, A. Ruchimat· Jurnal Phi; Jurnal Pendidika...· 0 citations
Research conducted in Pomalaa Subdistrict, Kolaka Regency, Southeast Sulawesi, aimed to identify the potential and characteristics of groundwater in an area with complex geological conditions, dominated by ultramafic and sedimentary rocks. To achieve this objective, a multidisciplinary approach was used, including geological and hydrogeological mapping and direct geoelectric testing in the field. One of the main methods used in this study was a geophysical technique called Electrical Resistivity Tomography (ERT), which is capable of producing two-dimensional subsurface images based on variations in the electrical resistivity of soil and rock. The analysis results show that ultramafic rocks in this region have the potential to be free aquifers, with moderate to high hydraulic conductivity values, making them potentially usable as a source of clean water for the domestic needs of the local community. Meanwhile, the southwestern zone, which is composed of sedimentary rocks, shows the presence of a confined aquifer with high permeability and a relatively low water table, making it a more accessible source of groundwater. The integration of all geological, hydrogeological, and geophysical data provides a comprehensive picture of the distribution and quality of groundwater in the Pomalaa region. These findings provide a strong scientific basis to support strategies for the conservation and sustainable use of groundwater resources, as well as to make.
M. Salim, Dasapta Erwin Irawan, I. A. Sadisun et al.· Journal of Applied Geology· 0 citations
The Kuta region is one of the most developed tourism areas in the Central Lombok Regency. This development impacts the population that continues to increase in the area, thereby influencing the increasing need for groundwater. However, the study area tends to be dry, especially in the dry season and rainfall is very low. This is quite difficult for residents to find good aquifers for groundwater exploration. From this, subsurface lithology identification is carried out to determine the lithology of the subsurface layers to obtain potential aquifers. The method used is geoelectric vertical electrical sounding which is carried out at two location points with a track length of 500 meters and a spacing of 10 meters. From the analysis of the 1D resistivity curve produced in this survey, information on subsurface lithology at the measurement point, consisting of layers of clay, sandstone, and breccia, was obtained. At the MR-1 line there is sandstone lithology at a depth of 53-84.3 meters which is thought to have the potential to be an aquifer, while at the MR-2 line, the presence of sandstone lithology is at a depth of 67.5-110 meters. Therefore, this measurement location shows the prospect of the existence of an aquifer which is characterized by a layer of sandstone which is a rock with good porosity and permeability
Warni Multi, Arif Wijaya· Jurnal Pendidikan, Sains, Ge...· 0 citations