Assessing Water Availability and Unmet Water Demand Using the WEAP Model in the Semi-Arid Bweengwa, Kasaka and Magoye Sub-Catchments of Southern Zambia

Located in the semi-arid zone of Zambia, Mutama-Bweengwa, Kasaka and Magoye sub-catchments have witnessed a high demand for water due to increase population socio-economic activities putting more pressure on resources. This study assesses hydrological components ascertains available resources unmet using Water Evaluation And Planning (WEAP) Model hydrometeorological data collected between 1951 2018. The model was calibrated validated 1971-1981 2008-2018 respectively. results reveal that transitioned from positive negative balance with -164.295 Mm3/year -19.021 -86.368 Magoye. Evaporation 1815.259 1162.655 1505.664 has been increasing over time various purposes such as irrigation, domestic, urban/rural supply livestock. overall storage showed year observed simulated peak streamflow were 8.16 m3/s 7.7 occurring during month January February WEAP performance achieved R2 0.98 calibration 0.95 validation, an NSE 0.83 0.85 validation. values objective functions show hydrology predicted by provides satisfactory confidence prediction future hence projection based scenarios.