Characterization of surface water quality in the Luapula River Basin and developing a WQImin model for potential inter-basin water transfer to the Kafue River Basin in Zambia

This study underscored the importance of water quality, providing insights for sustainable resource management. The study focused on the Luapula River Basin (LRB) in Zambia, a potential donor for inter-basin water transfers to the Kafue River Basin (KRB). The research objectives included establishing baseline data on surface water quality and developing a cost-effective water quality index model (WQImin) for regular monitoring. Data collected reveals spatial-temporal variations influenced by precipitation patterns, geological factors and anthropogenic activities, notably evidenced by elevated coliforms, iron, turbidity, sodium and chloride levels in specific areas. Hydrochemical analysis characterized the surface water as a calcium–magnesium–bicarbonate type, indicating underlying geological geology rich in silicates. The average WQI for the LRB was 38%, indicating that the LRB has good quality water, making the implementation of inter-basin water transfer to the KRB feasible. A multi-linear regression model was developed for predicting the WQI (WQImin) value based on only five parameters. The WQImin model simplifies water quality monitoring by using a minimal yet representative set of parameters, reducing time and costs. It also aids in assessing inter-basin transfer impacts, supporting decision-making for sustainable water availability, ecosystem protection and sustainability of livelihoods.