ANALYSIS OF LANDSLIDE SUSCEPTIBILITY ZONES POST-2022 CIANJUR EARTHQUAKE BASED ON 2D RESISTIVITY MODELING AND AIUDIO MAGNETOTELLURIC DATA Nurhasan-Sparisoma Viridi-Iradati Zahra-Dini Fitriani-Andika Pratama-Gita Amelia-Nipta Dwi Setyo Risky-Indriyati-Bagus Endar-Enjang Jaenla Mustopa-Wahyu Srigutomo
Bandung Institute of Technology
Abstract
The 2022 Cianjur earthquake caused severe damage, including significant landslides in Cijedil Village, Cugenang District, Cianjur Regency. This study aims to identify the slip plane as one of the factors triggering landslides using the Wenner-Schlumberger configuration of the geoelectric resistivity method. Additionally, this study models the landslide susceptibility zoning in Cianjur Regency through a geospatial approach based on probabilistic statistics using the frequency ratio method. This method is used to analyze the relationship between causative parameters and historical landslide occurrences to generate a more accurate landslide susceptibility map.
The results of geoelectric analysis from three survey lines on the Cijedil slope indicate that the slip plane depth ranges from 5 to 15 meters. This depth data is then integrated as one of the parameters in the frequency ratio modeling to improve the accuracy of landslide susceptibility zoning. This approach introduces a novelty in susceptibility zoning studies, which typically rely solely on spatial data. The geospatial modeling results show that the obtained zoning has a high level of accuracy, with an AUC validation value of 0.892. The high-susceptibility area covers 5.92% of the total region, with more than 25% of landslide events detected in this zone. The findings of this study are presented in a thematic map titled ^Landslide Susceptibility Zoning in Cianjur Regency, West Java,^ which is expected to serve as a reference for landslide disaster mitigation efforts in the region.
Keywords: slip surface, frequency ratio, geographic information, resistivity geoelectric, landslide susceptibility zone
