Search

Mangrove ecosystems provide key ecosystem services in coastal areas. This study describes the riparian mangrove of the Wouri estuary, in the Douala region (Cameroon), emphasizing the changes in this ecosystem over the past decade and its current state. It highlights the different groups of actors who participate in the management and regulation of the resource. Finally, an analysis of the governance of the mangrove wood resource based on the theory of common goods by Elinor Ostrom (1990) is proposed by examining the results obtained from the previous points. The scientific interest lies in contributing to a better understanding of the socio-ecological changes in the mangrove in the context of increasing anthropogenic pressures, highlighting the governance challenges and conservation opportunities in a strategic region of Central Africa. This research reveals complex processes that characterize mangrove ecosystems on the Manoka and Cap Cameroon Islands. The lack of urbanization regulations, continued infrastructure growth, repeated flooding, and coastal erosion all have a negative impact on natural landscapes and forests. The use of wood for smoking and fishing, as well as coastal pollution resulting from deficient garbage management, also have a considerable influence. Strategic interventions are needed to ensure sustainable ecosystem management. Recommendations include the application of rules to prevent forest overexploitation. [ABSTRACT FROM AUTHOR]

Sone Essoh, W.; Onguene, R.; Ndongo, B.; Nshagali, G.; Colmet-Daage, A.; Marie, G.; Iroume, J.; Stieglitz, T.; Besck, F.; Efole Ewoukem, T.; Tomedi Eyango, M.; Etame, J., and Braun, J.J., 2023. Using GIS and multicriteria analysis to map flood risk areas of the Tongo Bassa River Basin (Douala, Cameroon). Journal of Coastal Research, 39(3), 531–543. Charlotte (North Carolina), ISSN 0749-0208. The present study aimed to map the areas at risk of flooding in the Tongo Bassa watershed (42 km2) located in the heart of the Cameroonian economic capital (Douala) in the tropical zone of Central Africa, more precisely in the Wouri Estuary, at the bottom of the Gulf of Guinea. Like most of the world's major cities, Douala is subject to floods. The methodological approach was to identify the flooding risk determinants in the area from an extensive literature review and field surveys and then analyze these factors and map areas at risk of flooding using the analytical hierarchy process approach coupled with the GIS environment. The results revealed that four parameters of the natural environment (elevation, drainage density, distance to the river, and land cover) were the factors that mainly influenced the phenomenon of flooding in the region. Three major classes of flood risk were highlighted: low risk, medium risk, and high risk. To validate the effectiveness of the flood risk map obtained, the flood points collected in the field were cross-checked for ground truth after a flood occurred in the watershed. This cross-check between the resulting map and the flood points using GIS tools showed a good representation of the flooded area. This result is quite interesting because the areas where the risk of flooding is high are consistent with those where flooding is most frequent. The presented results constitute a basic decision support tool for the management of flood zones by the public authorities and the decentralized territorial communities of the city of Douala. [ABSTRACT FROM AUTHOR]