Assessing Spatial-temporal Variations in Vulnerability to Climate Change Impacts in Agroecological Zones of Uganda

Abstract

Uganda is among the world’s most climate-vulnerable countries, ranking 15th in vulnerability and 147th in readiness globally. A majority of its population resides in climate-sensitive regions prone to droughts and floods, particularly in the Northern and Eastern agroecological zones (AEZs). This study assessed the spatiotemporal vulnerability of Ugandan agroecological zones to climate variability and change by analyzing historical and projected climate patterns alongside socio-ecological vulnerability patterns. Historical rainfall data from CHIRPS (1981–2024) and temperature data from MERRA-2 (1981–2024) were used to evaluate long-term climate variability, while future climate patterns were derived from the multi-model ensemble (MME) of six CMIP6 models under SSP2-4.5 and SSP5-8.5 scenarios. To assess vulnerability, a multi-criteria approach guided by the IPCC Framework of vulnerability was employed, integrating biophysical and socio-economic indicators through a weighted linear combination to derive exposure, sensitivity, adaptive capacity, and composite vulnerability indices. Results indicated an overall increasing trend in rainfall across Uganda’s AEZs, though trends were not statistically significant. Spatially, AEZs in Karamoja consistently received the lowest rainfall, while Southwestern Highland, Lake Victoria Crescent, and Mount Elgon areas remained relatively wetter. Temperature trends, in contrast, showed a statistically significant rise across the country, with the hottest areas located in West Nile and Karamoja AEZs, and cooler regions in the Southwest and Mount Elgon AEZs. Projected rainfall trends suggest further intensification, especially under the SSP5-8.5 scenario with seasonal shifts of increasing SON and uncertain MAM. The vulnerability assessment revealed pronounced regional disparities, with Northern region, especially Karamoja and West Nile AEZs emerging as vulnerability hotspots due to high exposure, high sensitivity, and very low adaptive capacity linked to harsh climatic conditions, socio-economic marginalization, ecological degradation, and limited infrastructure. This study highlights that climate vulnerability in Uganda is shaped by an intersection of climatic stressors and structural inequalities, transcending agroecological and administrative boundaries. Findings call for a shift in adaptation planning from a generalized national approach to regionally and agroecologically targeted interventions that strengthen local absorptive, adaptive, and transformative capacities. Policymakers and stakeholders must develop and implement climate vulnerability reduction strategies at the local level, guided by spatially explicit data, to enhance community resilience and safeguard development gains.