Spatial-temporal analysis of Sunda Strait Mangrove Health Index (MHI) via Sentinel-2 for sustainable blue economy

Continuous monitoring of mangrove forest conditions is essential to support a sustainable blue economy through informed land use planning, conservation, and rehabilitation strategies. This study investigates the spatial and temporal dynamics of the Mangrove Health Index (MHI) in the Sunda Strait region using Sentinel-2 satellite imagery for the years 2015, 2020, and 2025, focusing on the Sumur Coastal Area, Pandeglang, Banten. The analysis utilized three vegetation indices: the Normalized Burn Ratio (NBR), Green Chlorophyll Index (GCI), and Structure-Insensitive Pigment Index (SIPI). Results indicate a positive trend in ecosystem health. The average NBR increased from 0.416 in 2015 to 0.450 in 2025, GCI from 1.14 to 4.88, and SIPI from 0.84 to 1.04. Mangrove areas in poor condition (MHI < 33.3%) decreased from 684.15 ha to 376.78 ha, while areas in very good condition (MHI > 66.8%) increased from 548.39 ha to 945.29 ha. The moderate condition category (33.3% ≤ MHI ≤ 66.8%) declined from 3,124.11 ha to 2,159.87 ha. These findings highlight significant mangrove vegetation recovery, though some degradation persists due to land conversion. This research provides a scientific contribution to the development of a remote sensing-based mangrove health monitoring method with the integration of multitemporal vegetation indices and field survey validation. This approach can be replicated in other coastal areas as a basis for decision-making in sustainable mangrove ecosystem management.