Mapping Mangrove Zonation Changes in Senegal with Landsat Imagery Using an OBIA Approach Combined with Linear Spectral Unmixing

Mangrove areas in Senegal have expanded over the past two decades, but zonation dynamics vary significantly between the Saloum Delta and Casamance Estuary. The study reveals that while Rhizophora mangle thrives and reproduces effectively across both regions, Avicennia germinans struggles with reproduction, potentially limiting mangrove colonization in upper tidal zones of the Saloum. This research employed a novel method combining Object-Based Image Analysis (OBIA) with linear spectral unmixing using high-resolution Landsat imagery to track these changes with high accuracy (kappa indices of 0.8 and 0.83). The findings suggest that conservation efforts should prioritize reforestation in the Saloum Delta, focusing on Avicennia germinans to address long-term regeneration gaps, rather than in Casamance where colonization is already underway.

Lombard, F., & Andrieu, J. (2021). Mapping Mangrove Zonation Changes in Senegal with Landsat Imagery Using an OBIA Approach Combined with Linear Spectral Unmixing. Remote Sensing, 13(10), 1961. https://doi.org/10.3390/rs13101961