Abstract:
Effective planning and integrated management of water resources in a rapidly
changing environment under the influence of climate change and anthropogenic
activities relies on consistent monitoring of changes in a river basin from these diverse
impacts. The identification of the root causes of changes in river basins will inform the
development and use of appropriate interventions. In the Mokolo River Basin of
Limpopo, a comprehensive modelling study was conducted to evaluate water demand
and supply dynamics using the Water Evaluation and Planning (WEAP) framework.
This study involved manual calibration of the catchment, yielding calibration results
characterised by a coefficient of determination (R²) of 0.80 and a Nash-Sutcliffe
Efficiency (NSE) of 0.55, alongside validation results of R² = 0.70 and NSE = 0.61.
These metrics indicate a fair level of model performance, suggesting that the WEAP
model can effectively simulate the hydrological processes within the basin. The
analysis revealed that water demand was adequately met for the baseline year of
2010, indicating a stable supply-demand equilibrium during this period. However,
projections for the future, specifically from 2025 to 2045, indicate a significant
challenge in meeting water demand, particularly within the mining and industrial
sectors. This anticipated unmet demand highlights the pressing need for strategic
water management interventions in the basin. Five management scenarios were
therefore implemented to address these issues, focusing on reducing water use
across irrigation, domestic, and industrial sectors, while also considering inter-basin
water transfers as a viable solution. The results of these scenarios demonstrated that
implementing such measures could substantially alleviate unmet demand,
accentuating the importance of integrated water resource management strategies in
the face of increasing water scarcity.
