Mitigating water imbalance between coastal and inland areas through seawater desalination within China

Abstract

At present, more than 142 seawater desalination projects have been built in China, which effectively alleviate freshwater scarcity pressure in coastal cities while showing little effects on inland areas. Through evaluating seawater desalination distribution, it is practical to analyze optimal water transfer path to mitigate freshwater imbalance and alleviate freshwater shortage pressure. Based on the compiled list of seawater desalination projects, this study evaluated the embodied water consumption of China's seawater desalination projects in 28 coastal cities and 9 provinces/municipalities. Taking the desalination water availability, desalinated water proportion, and regional water disparity into consideration, the overall plan for the optimal water transfer path are proposed to balance the desalination water resources based on the particle swarm optimization algorithm (PSO). When compared, the desalinated water resources reached an increasingly high proportion in local water production capacity, and the water mitigation degree through seawater desalination kept increasing. The optimal water transfer planning has the potential to ease the imbalance of desalination water distribution and lower water shortage pressure in water-scarce areas, which is expected to allocate freshwater resources and promote sustainable water management from a nationwide perspective.