Assessment of tropical cyclone vulnerability in East Africa coastal areas using a GIS-based Analytic Hierarchy Process: the case of Dar es Salaam Metropolitan City, Tanzania

Dar es Salaam Metropolitan City, Tanzania, faces an emerging tropical-cyclone threat because of its coastal setting, dense population, low-lying terrain, and uneven adaptive capacity. Using the Intergovernmental Panel on Climate Change framework, this study assessed vulnerability through 17 indicators grouped under exposure, sensitivity, and adaptive capacity. Indicator weights were derived through GIS-based Analytic Hierarchy Process pairwise comparisons, informed by literature and a consensus discussion among three experts in meteorology, agrometeorology, and natural-resource management. All spatial layers were aligned to a common 30 m resolution. The analysis shows that 23.16% (376.20 km2) of the metropolis is highly vulnerable. A major hotspot occurs in the central coastal zone around Dar es Salaam port and the Kariakoo commercial hub, where high population density, low elevation, and shoreline proximity interact. Temeke (65.77%), Kinondoni (49.61%), and Ilala (32.36%) have the largest proportions of high vulnerability, whereas Kigamboni has the lowest (0.39%). These findings provide a spatial basis for emergency preparedness and resilience planning especially in coastal metropolis as the occurrence of TCs originating in the Southwest Indian Ocean increasingly shifts northward toward the East African coast due to climate change.