Optimization of water intake systems: Based on water-carbon relationships and sustainable development goals

Achieving sustainable development goals requires strategically balancing the trade-off between water resource utilization and carbon emissions. It is of particular importance to systematically study the relationships between water conservation and emission reduction (water-carbon relationship) in a water intake system, and to optimize the water intake structure accordingly. This study proposes a multi-objective optimization framework to explore the spatial–temporal characteristics of the water-carbon relationship in water intake systems and optimize the water-carbon relationship in water intake systems. The results show that the total carbon emissions from water intake system in China increased from 106.4 Mt in 2010 to 115.6 Mt in 2020, while there was a decrease of 27.2 billion m³ in water intake volume. Prioritizing carbon reduction can reduce carbon emissions by up to 13.5 Mt. The optimization of regional water intake structures necessitates a comprehensive consideration of the uneven distribution of water resources. Regions endowed with abundant water resources should prioritize carbon reduction initiatives, whereas water-scarce regions should focus on water conservation strategies. For the water-receiving areas of water diversion projects, it is essential to balance both energy efficiency and carbon emission reduction. This paper proposes a water-carbon multi-objective optimization framework designed to mitigate water scarcity and alleviate carbon emission pressures. By adjusting the water intake structure and reallocating water intake tasks among various projects, this framework aims to achieve the sustainable development of water and carbon systems.