Geospatial Insights into Blue Carbon Recovery and Policy Pathways: Urban Mangrove Dynamics in Bengkulu, Indonesia

Abstract

Mangrove ecosystems are crucial blue-carbon reservoirs, yet their long-term spatial and temporal dynamics along Indonesian urban coasts remain poorly understood. This study mapped 30 years (1995-2025) of mangrove cover and carbon stock trajectories in Bengkulu City, Indonesia, using integrated remote sensing analysis and field validation. Multi-temporal Landsat and Sentinel imagery indicated a 70.3% decline in mangrove area, dropping from 283.21 ha in 1995 to 84.05 ha in 2015, followed by a 43.9% recovery to 120.93 ha by 2025. Biomass carbon stocks decreased from 39,689 Mg C to 11,767 Mg C but rebounded to 16,930 Mg C. Spatial analysis revealed that the main factor contributing to degradation was the expansion of aquaculture. However, communityled restoration efforts and government intervention significantly aided recovery. These results indicate that severely degraded mangroves can significantly restore their carbon potential through ongoing collaborative rehabilitation efforts aligned with Indonesia's Nationally Determined Contributions (NDCs). The findings offer empirical support for incorporating blue-carbon spatial intelligence into coastal climate mitigation policies in rapidly urbanizing tropical cities.