Geographia Technica, Vol 21, Issue 1, 2026, pp. 145-165
SPEI-BASED DROUGHT PROJECTIONS FOR UGANDA UNDER CLIMATE CHANGE SCENARIOS USING THE CANESM5 CMIP6 MODEL
Obed BYAMUKAMA 
, Ronald SSEMBAJWE , Mihai VODA , Brian Odhiambo AYUGI
ABSTRACT: Drought is one of the most recurrent and damaging climate extremes in Uganda, affecting agriculture, water resources, and livelihoods. However, its future trends under changing climate conditions remain poorly understood. This study analyzed historical and projected drought characteristics across Uganda. We used the Standardized Precipitation–Evapotranspiration Index (SPEI) derived from the bias-corrected CanESM5 model within the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6) framework. Three Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5) representing low, medium, and high emissions scenarios were considered. Terra-Climate data for 1985–2014 were used for bias correction and validation. Drought duration, frequency, severity, and intensity were calculated from 3-month SPEI, and spatial clustering was assessed using the Getis-Ord Gi* statistic. Historical analysis shows drying trends in northern and central Uganda. Future projections reveal spatially heterogeneous drought responses. During the mid-century (2041–2070), drought occurrence increases under SSP1-2.6 in central and northern regions but decreases under SSP2-4.5 in the central-west and under SSP5-8.5 in Karamoja. Toward the late century (2071–2100), SSP1-2.6 indicates a general decline in drought occurrence, SSP2-4.5 shows increasing droughts in the east and reductions in the northwest, and SSP5-8.5 projects widespread intensification across southern, western, and northern Uganda. Hotspot analysis identifies persistent drought clusters along the cattle corridor, extending from the Ankole–Kigezi regions and Karamoja. These findings provide a detailed understanding of Uganda’s evolving drought risks and support targeted adaptation planning, water resource management, and climate-resilient livelihood strategies.
Keywords: Climate models; Drought projection; SPEI; NEX-GDDP-CMIP6; Uganda
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