Optimized Coordination of Urban Water Usage in China’s Minjiang River Basin under the Influence of Climate Change

Abstract

This study investigated the current and potential future impact of climate change on water resources in the Minjiang River Basin, Fujian Province, China. Coupling a statistical downscaling model (SDSM) model and the Soil and Water Assessment Tool (SWAT) model, and considering the Coupled Model Intercomparison Project (CMIP) CMIP5 Representative Concentration Pathway (RCP) RCP2.6, RCP4.5, and RCP8.5 scenarios, we found a notable upward trend (2.9%, 7.5%, and 12.3% increase, respectively) in multiyear average runoff. A system dynamics feedback model was applied to optimize water resource allocation for Fuzhou, Sanming, and Nanping cities in the Minjiang River Basin, considering the runoff predicted by the SWAT model under climate change. The prediction results show that industrial water use steadily decreases, whereas water consumption in the tertiary sector increases concurrently. By 2050, water allocation schemes have reached the level of moderately developed countries, with these schemes taking into consideration the constraints imposed by red lines for water usage upper limit in China. These findings provide insights into the current and potential challenges posed by climate change, and can guide effective water resource planning for Minjiang River Basin cities.