Optimisation approach toward water management and energy security in arid/semiarid regions

Abstract

This paper aims to develop, in a case of multiple water sources, an optimal operational strategy that can be used in arid/semiarid regions by water decision-makers to schedule the use of each source over time, to control the artificial recharge to aquifers, to improve the energy efficiency related to the water supply system, to determine the optimal amount of water each source should supply over a period, and to minimise the water costs. In this regard, a novel, cost effective, and advanced optimal controller to operate a water supply system in arid/semiarid regions has been developed. This model is designed as a multi-constraint non-linear programming model that meets the demand for an ever-growing population, and considers in its formulation multiple surface water sources, aquifers, desalination plants, recycled water plants, the seasonal availability of surface water and groundwater, the monthly rainfall variability, and the seasonal energy price. To verify the effectiveness of the developed model, a real case study was conducted. The results obtained showed a 3% reduction in the water supply cost and sustainable improvement in groundwater management, demonstrating the model’s capacity to manage aquifer recharge efficiently, to optimally schedule the use of water sources. Adopting this strategy improves water security and the energy security in an urban region as it decreases the use of energy-intensive water sources during seasons with high electricity demand.