Identifikasi Keberadaan Akuifer di daerah Mersam berdasarkan Data Resistivitas

The Geoelectric resistivity method is part of the geophysical method to identifying subsurface trough the physical properties of rock with electrical properties and porosity in rocks. The research conducted in the Mersam Village area, Mersam District, Batanghari Regency used a schlumberger configuration with 2 sounding points and a track length of 100 m toi identify the presence of groundwater acquifers to meet the increasing clean water needs of the population. The result of the treatment that has been carried out, obtained at the station 1 the presence of a groundwater acquifer is found in the second layer with a value of 74.28 Ωm at a depth of 1.83 – 10.88 m identified as a layer of sand and coarse sand and a fourth layer at a depth of 38.23 – 71.18 m with a resistivity value of 69.44 Ωm identified as a layer of coarse sand and medium sand. At the station 2, the presence of a groundwater acquifer in the third layer was identified as a layer of fine sand and tufaan sand with a value of 63.20 Ωm and wa at a depth of 15.18 – 43.55 m.Keywords: Geoelectric, Schlumberger, resistivity, aquifers, groundwate

Studi Penentuan Kedalaman Akuifer Air Tanah Desa Rantau Gedang dengan Konfigurasi

This study aims to identify the depth of the groundwater aquifer and the thickness of the aquifer layer using the Schlumberger configuration resistivity geoelectric method. The data used in this study was obtained from field data collection (data acquisition) carried out in the Rantau Gedang Village area, Mersam District, Batanghari Regency, Jambi Province. The resistivity geoelectric method is one of the geophysical methods often used in exploration for the identification of subsurface groundwater aquifers. This method is carried out by conducting an electric current into the bowels of the earth and calculating the resistivity value of the rock when it is electrified. Groundwater aquifers are distinguished into 4 types. Rantau Gedang Village Area, Mersam District, Batanghari Regency, Jambi Province is one of the areas that has great aquifer potential. Data processing is carried out using IPI2Win and PROGRESS V3 software. The result of data processing is the value of resistivity and depth vertically in rock layers. The resistivity of the top soil zones of track 1 and 2 is 1.70-5.52 ohm.m, the resistivity of the free aquifer is 41.59-52.41 ohm.m, and the resistivity of a good aquifer is more 90.03-95.21 ohm.m. The depth of the top soil zone is 0-4.14 m, the depth of the free aquifer is 4.14 -31.65, and the depth of a good aquifer is 80.16-81.66 m. With an approximate thickness reaches 50

ANALISIS KERENTANAN TANAH FAKULTAS SAINS DAN TEKNOLOGI UNIVERSITAS JAMBI DENGAN MENGGUNAKAN DATA MIKROTREMOR

Research has been carried out to carry out soil vulnerability analysis at the Faculty of Science and Technology, Jambi University. The construction of buildings at the Faculty of Science and Technology has necessitated an analysis of the vulnerability of the land around the buildings at the Faculty of Science and Technology. Based on the regional geology in this area, the Muara Enim formation (TMPM) is formed in the Tertiary age which is composed of rocks from interbedded tuffaced sandstones with tuffaced mudstones, interbedded quartz sandstones with quartz mudstones, interbedded with coal and iron oxide. The rocks formed in this formation are a type of sedimentary rock. To carry out soil vulnerability analysis, the HVSR method is applied to measure microtremors. Microtremors are a geophysical method that uses very small and continuous ground vibrations. This HVSR method is a passive seismic method using three components, namely 2 horizontal components and 1 vertical component. Microtremor measurements on the ground were carried out at 6 points around the building. The results obtained from microtremor measurements using the HVSR method are the natural frequency (f0), amplification factor (A0) and Seismic Vulnerability Index (Kg). The natural frequency (f0) value ranges from 1.30-1.82 Hz, the amplification factor (A0) value ranges from 1.69 - 3.28 times and the seismic vulnerability index (kg) value ranges from 1.814167 to 5.948834 x 10^-6 s^2/cm. Based on the Kanai classification, a frequency value < 2.5 HZ includes soil type IV and soil type II with Alluvial Rock lithology formed from delta sedimentation, top soil, mud. With a depth of 30 meters or more. This area has a very thick surface sediment, more than 30 meters. Based on the classification according to Setiawan, the amlification factor is classified as low (A0<3) to medium (3<A0<6). A low to moderate amplification factor indicates that the rock that makes it up is compact/hard. Based on the Refrizon Classification, the Seismic Vulnerability Index value is in the low (kg<3) to medium (3<kg<6) category. The seismic vulnerability index is low to medium, meaning that if a shock occurs there will be no damage because the vulnerability value is medium - low. Based on these three parameters, it can be concluded that the land around the FST building is still classified as safe from shocks