Climate change scenarios across South-Kivu agroecological zones, Eastern D.R. Congo.

Characterizing climate projections to capture agroecological heterogeneity and topographic gradients is essential for localized planning in complex terrains. This study evaluates historical trends and projected changes in temperature and precipitation across six agroecological zones (AEZs) in South-Kivu, Democratic Republic of the Congo under SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios. We evaluated seven CMIP6 models using the Taylor Skill Score (TSS), selecting the three best-performing models per variable and AEZ to construct zone-specific multi-model ensembles. Bias correction was performed using Quantile Mapping (QM) with a two-fold cross validation design (1983-1998 and 1999-2014). Selected models demonstrated high ranking stability across independent historical windows, achieving a weighted mean stability index of 0.83 for precipitation, 0.94 for maximum temperature (Tmax) and 1.00 for minimum temperature (Tmin). For precipitation, BCC-CSM2-MR excelled in low-altitude zones, while CMCC-CM2-SR5 and MPI-ESM1-2-HR were more effective in high-altitude zones. MRI-ESM2-0 and GFDL-ESM4 performed best for temperature across most AEZs. Climate trajectories were analyzed for near-term (2026-2050), mid-term (2051-2075) and long-term (2075-2100) periods relative to a 1983-2014 baseline. Reported projections represent the ensemble mean, while inter-model spread is detailed in the results. Results indicate continuous warming across all AEZs, with Tmin increasing more rapidly than Tmax. Province wide for the near (long) term, Tmax increases range from 0.78 °C (1.64 °C), 0.82 °C (2.59 °C), to 0.87 °C (2.85 °C) under SSP2-4.5, SSP3-7.0, and SSP5-8.5; Tmin increases range from 1.08 °C (2.12 °C), 1.13 °C (3.12 °C), and 1.25 °C (3.46 °C), respectively. Precipitation projections reveal non-linear, AEZ-differentiated trajectories characterized by near-term reductions followed by a long-term transition toward wetting in several zones. The EMAZ exhibits persistent declines (-9.8%) and the THMAZ shows a late-century wetting (+ 21%) under SSP5-8.5. Furthermore, a shift in seasonal redistribution is projected, with the long rain season intensifying and the short rain season contracting. These findings characterize the range of plausible climate trajectories in South Kivu, providing a necessary evidence base for future risk-targeted adaptation planning in eastern DRC and comparable tropical mountain systems.