Spatiotemporal Mangrove Dynamics in Cacheu, Guinea-Bissau (2020-2025): Remote Sensing-Based Change Detection and Driver Analysis

Classification reference areas were selected via high resolution imagery, and 30% of reference areas were kept for validation, achieving an overall accuracy above 95% at both time steps. Total mangrove extent declined by 13% over the study period from approximately 123,000 ha to 107,000 ha. Within this net change, opposing dynamics unfolded across the region: the eastern sub region was characterized by mangrove losses at forest margins, while the western sub region showed canopy densification representative of mangrove recovery.

Rice paddies are historically the major source of mangrove deforestation within Cacheu but their extents remained stable across both time steps. Achieved accuracies may partly reflect the classifier's internal consistency rather than true land cover correspondence. Reference areas were derived exclusively from remote sensing interpretation, with no field-based ground truthing conducted.

Future studies integrating in-situ validation would better constrain classification uncertainty and strengthen confidence in the reported patterns of change.