Identifikasi Daerah Rawan Bencana Banjir Menggunakan Citra Sentinel-1 Dan Google Earth Engine (Gee) Di Kabupaten Jember

Abstract

Flood disasters in Jember Regency require adaptive mitigation management based on accurate spatial data. This study aims to identify the level of vulnerability and extent of flood inundation in Jember Regency for the period 2023-2025 using Sentinel-1 Imagery and Google Earth Engine. The method used is a descriptive quantitative method based on Geographic Information Systems (GIS) through scoring and overlay techniques on three main physical parameters, namely rainfall, elevation, and slope gradient. The results of the spatial analysis show that Jember Regency is divided into three flood vulnerability classes: medium vulnerability (19.36%), high vulnerability (51.61%), and very high vulnerability (29.03%). Rambipuji sub-district was identified as a highly vulnerable area. The total detected actual inundation reached 542.37 km², with the largest inundation located in Tempurejo sub-district, covering 132 km². There is a discrepancy between the potential flood vulnerability map and the actual field inundation. This variation occurs because the vulnerability map depicts long-term flood potential projections, whereas Sentinel-1 imagery only captures temporal inundation conditions at a specific point in time.