Identification of Vulnerability Due to the Pasaman M6.2 Earthquake on 25 February 2022 Using Satellite-Based Methods and Field Surveys

Abstract

The Pasaman earthquake which occurred on 25 February 2022, with a magnitude of 6.2, caused casualties and infrastructure damage. Vulnerability identification determines the potential extent to which a system or unit tends to be damaged. Vulnerability identification in this study was carried out based on four vulnerability indicators, namely: rate of soil movement from satellite image processing, soil type classification based on Vs30, corrected isoseismal shakemap, and residential area maps. Each indicator, with their respective weightage, is then scored and summed to evaluate the vulnerability of areas in the vicinity of Pasaman earthquake. The processing of Sentinel-1 SLC satellite data using the advanced Differential Interferometric Synthetic Aperture Radar (DInSAR) produces a deformation rate around area of epicenter. Areas that have high vulnerability generally have a value of ground movement rate in the form of subsidence above 5 cm/year. These areas were predominantly residential and experienced significant damage during the earthquake. The soil type in these regions was classified as medium soil, and the intensity of shocks during the earthquake was categorized as VI MMI or higher. This study was conducted in the area near the epicenter of the Pasaman earthquake, such as in the district Pasaman, Bonjol, Pasaman, Palembaya, and Lubuk Basung. A study of disaster vulnerability identification is carried out to reduce the losses and minimizing the exposure of the population to disasters. The results of vulnerability identification can be used as part of education and literacy to reduce the risk of earthquake disasters.