Optimal allocation of urban water resources under dual constraints of carbon emissions and sponge city construction: models and applications

ABSTRACT Water resources are essential for human survival, economic development, and ecological balance. However, they are significant contributors to greenhouse gas emissions in urban production and utilization. Despite this, research on integrating carbon reduction objectives into water resource allocation remains limited. This paper constructs a model for optimal allocation of urban water resources including unconventional water resources based on carbon emissions, and studies it in Pingliang City as an example, using NSGA-III algorithms to solve its allocation scheme. The results show that compared with the traditional configuration scheme, the proposed carbon emission reduction-based allocation model achieves cumulative carbon emission reductions of 153,000 and 267,000 metric tons for the planning period 2025–2040. Additionally, the cumulative economy can be obtained in 2025–2040 is 934,800–9,482,900 yuan and 163,141,000–16,548,700 yuan, respectively. This study can help to promote the rational utilization of urban water resources and the coordinated development of the economy, society, and environment in China, and provides a scientific basis for the sustainable development policy of water resources, which is important for realizing the goal of ‘double carbon’ in China.