River Enyau sub-catchment, the main source of surface water for Arua Municipality and the surrounding areas is experiencing increasing frequency of hydrological droughts attributed to climate and land use/cover change. The increasing frequency of hydrological drought in the sub-catchment threatens 72% of the household’s access to safe water and increases their vulnerability to food insecurity, water and sanitation challenges. The aim of this study was to i) reconstruct past (1980 – 2009) and ii) project near future (2025 - 2039) hydrological drought characteristics under changing climate and land use/cover in River Enyau sub-catchment. Past and future discharges were analyzed for hydrological drought frequency, duration and severity using the Threshold Level Method in R software version 3.5.2. Future climate was downscaled from 29 Coupled Model Inter-comparison Project Phase Five (CMIP5) models following the Agricultural Model Inter-comparison and Improvement Project (AgMIP) protocol for scenarios RCP 4.5 and 8.5 using the delta method. Future (2039) land use/cover was projected using the Markov chain model in Land Change Modeler of the TerrSet software. The projected climate (2025-2039) and land use/cover (2039) data were used as inputs in the Soil and Water Assessment Tool (SWAT) model to simulate the future discharge of the sub-catchment. Result showed that most of the hydrological drought in the past started in the month of March and ended in April. Same results were projected under RCP 4.5 while most drought are projected to start and end in April under RCP 8.5. Increase in the land area of bareland and built up areas and decrease in the area of woodlot contributed to increase in hydrological drought frequency and duration in the past period. Significant differences (p<0.001) in the annual hydrological drought characteristics among the different drought years of the past and for the near future were observed. Comparison of the past and projected hydrological drought characteristics under RCP 4.5 and 8.5 showed a significant difference in frequency (p<0.001) and no significant difference for duration and severity (p>0.05). Therefore, there is need to i) protect the woodlot in the sub-catchment from destrcution and ii) identify best management options for reducing the impact of bareland and built up areas on hydrological drought in River Enyau sub-catchment.

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