ABSTRACT

IDENTIFICATION OF SUBSURFACE LITHOLOGICAL AND HYDROLOGICAL CONDITIONS AT CAMPUS II OF LAMBUNG MANGKURAT UNIVERSITY, BANJARBARU

(By: I Nyoman Eva Kastika; Dr. Sri Cahyo Wahyono, S.Si., M.Si.; Ibrahim Sota, S.Si., M.T.; 2026).

The objective of this study is to analyzesubsurface lithological conditions based on the distribution of resistivity values using the Wenner configuration resistivity method in the area of Campus II, Lambung Mangkurat University, Banjarbaru, South Kalimantan. The resistivity method was employed because it is capable of identifying variations in the electrical resistivity of subsurface materials, thereby providing a non-destructive characterization of subsurface lithological conditions. Field measurements were conducted using the Wenner electrode configuration, and the apparent resistivity data were processed to generate a subsurface resistivity model. The resulting model was subsequently interpreted based on resistivity values and the local geological setting. The interpretation results indicate that the subsurface resistivity values range from 21.61 to 1292.67 Ω.m, with an investigation depth of approximately 20 m. Based on the resistivity classification, the subsurface is predominantly composed of three lithological units: clay, with resistivity values ranging from 21.61 to 30 Ω.m; sand, with resistivity values of >30–300 Ω.m; and dense soil, with resistivity values exceeding 300 Ω.m. The sand layer is interpreted as having the potentialto function as a groundwater-bearing formation (aquifer), whereas the clay layer acts as an aquitard that restricts groundwater flow. Zones exhibiting high resistivity values are interpreted as dense soilcharacterized by a higher degree of compaction. It can be concluded that the subsurface of the study area consists of clay, sand, and dense soil with both lateral and vertical variations in their spatial distribution. These findings provide valuable information for infrastructure development planning, groundwater resource management, and future geological and geophysical investigations within the Campus II area of Lambung Mangkurat University.

Keywords: Aquifer, electrical resistivity, hydrology,lithology, resistivity, Wenner configuration.