The Role of Mangrove Ecosystems in Erosion Mitigation: A Multitemporal Analysis of Coastal Vulnerability In Coastal Area Bantul

Abstract Bantul has the second highest potential after Kulon Progo in terms of tidal waves or erosion in the Yogyakarta Special Region. This area has historical records of disasters, including tsunami waves that have reached run-ups of between 3 and 10 meters on the southern coast of Java. This research aims to determine changes in the Coastal Vulnerability Index (CVI) and Mangrove Vulnerability Index (MVI) of Bantul in 2010, 2020, and 2030, as well as to identify mangrove areas for mitigation. The research was conducted using multi-temporal data through a multi-criteria spatial GIS approach and bio-geophysical variables. These variables represent variations in natural biological and geomorphic characteristics across the region, the distribution of human population density, local bathymetry and topography, and the relative wind and wave forcing associated with storms, with the unit of analysis based on the coastal ecoregion unit of Bantul Regency. The research found that the Bantul coastal area has various vulnerability indexes. The existence of mangrove habitat as a protector of natural ecosystems from erosion indicates that the CVI value decreases with the increase in mangrove forest area in the study area from 2010 to 2020. CVI modeling for 2030 also shows decrease in value compared to 2010 and 2020, assuming an expansion of the mangrove forest area to 19 times its existing size as planned in the regional spatial plan. The implications of this research are important for disaster adaptation and mitigation planning, expected to build sustainable coastal resilience.