Urbanisation is a major driver of landscape transformation in West Africa, resulting in the gradual conversion of natural areas into built environments and the degradation of ecosystem services. In Ziguinchor, this process is reflected in the continuous expansion of built-up areas at the expense of vegetation cover, while knowledge of long-term Land Use and Land Cover (LULC) dynamics remains limited. This study aimed to map the LULC classes of the Municipality of Ziguinchor, analyse their spatio-temporal dynamics between 1986 and 2026, and assess the principal landscape transformations associated with anthropisation and the conversion of landscape units.
The study used a remote-sensing approach based on Landsat imagery from the TM, OLI, and TIRS sensors, processed through supervised classification in ENVI Classic 5.3 and QGIS. LULC changes were analysed using transition matrices, the annual vegetation loss rate, and the anthropisation index. The results show a substantial increase in built-up areas, from 1,252.8 ha in 1986 to 1,992.6 ha in 2026, while vegetated areas decreased from 577.44 ha to 421.92 ha over the same period. The analyses also indicate increasing human-induced landscape transformation and declining stability of vegetation formations, which were predominantly converted into urban areas. These findings provide a basis for integrating higher-resolution satellite data, applying machine-learning methods, and assessing the effects of urbanisation on ecosystem services to inform sustainable land-use planning and the conservation of green spaces in the Municipality of Ziguinchor.
P. Faye, Fatoumata Yattara, Seydina Mouhamed Dieng et al.· Journal of Agriculture and E...· 0 citations
The municipality of Coubalan has substantial socioeconomic potential because its mangrove forest supports local livelihoods. However, the forest is exposed to pressures that reduce its extent and species diversity. This study examines mangrove landscape dynamics in Coubalan.
A diachronic analysis covering 1984–2024 used Landsat 5 TM, Landsat 7 ETM+, and Landsat 8 OLI-TIRS imagery processed in ENVI 5.3. Maximum likelihood supervised classification identified six land-use classes: mangroves; barren areas; water; mudflats; forests and savannas; and built-up areas, bare ground, fields, and fallow land. Water and mangroves were the most stable classes. During 1984–2003, mangroves and forests and savannas increased by 6.05% and 2.31%, respectively, while built-up areas, bare ground, fields, and fallow land and mudflats decreased by 2.86% and 7.56%. Mudflats converted to mangroves accounted for 5.90%. During 2003–2024, the trend reversed, with 7.84% of mangrove area converted into mudflats.
Across the full period, mangroves and forests and savannas had average annual spatial expansion rates of −0.45% and −1.45%, while built-up areas, bare ground, fields, and fallow land and mudflats increased by 0.31% and 0.56%. Annual deforestation rates were 0.41% for mangroves and 1.10% for forests and savannas, and the 2024 anthropization index was 1.94. Mangrove cover declined from 19.93% in 1984 to 16.68% in 2024. The findings may support local mangrove management, while further research is needed to identify the principal drivers of degradation.
P. Faye, Alioune Diop, S. Diop et al.· Journal of Applied Life Scie...· 0 citations
