Quantifying Coastal Vulnerability and the Protective Role of Mangrove Rehabilitation: A GIS–Remote Sensing Analysis From Mojo, Pemalang, Indonesia

ABSTRACT The coastal region of Pemalang, Central Java, is characterized by intensive anthropogenic activities such as fisheries, aquaculture, and settlements, which heighten its susceptibility to tidal flooding. This study quantifies the Coastal Vulnerability Index (CVI) along the Mojo coastline in Pemalang, Indonesia, using a weighted overlay approach integrating geomorphology, slope, elevation, land use (LU), distance from rivers (DfR), distance from the coastline (DfS), and tidal range (TR) parameters. Quantitative scoring and weighting were performed using a Geographic Information System (GIS) framework. The analysis employed Sentinel‐2A imagery acquired in December 2023, along with DEMNAS elevation and tidal observation data from 2023. Results reveal that medium vulnerability dominates the Pemalang coastline (47.86%), followed by low (26.32%), high (21.28%), not vulnerable (4.50%), and very high vulnerability (0.059%). Slope, geomorphology, and elevation were identified as the most influential parameters. Spatially, the northern tip exhibits the highest vulnerability due to strong ocean currents causing abrasion, despite extensive mangrove cover. This study represents the first spatially quantified CVI assessment conducted within the Mojo mangrove rehabilitation zone. The findings provide a scientific foundation for strengthening mangrove rehabilitation efforts and improving coastal flood mitigation strategies in Pemalang and highlight the importance of strengthening mangrove rehabilitation and regulating pond expansion to reduce long‐term vulnerability along the northern coast of Indonesia.