Simulation of population size and economic scale supportable by available freshwater in China in 2030

Limited water availability, population growth, and increasing water demand have resulted in freshwater crises in many countries, including China. In this paper, the water resource‐carrying capacity (WRCC) model simulated the trajectory of China's various systems, representing interactions among humans, water resources, and economics, among others. The results indicated that, at the national level, 700 billion m3 of available freshwater could support population sizes of 2.12, 1.96, and 1.85 billion, along with economic sizes of $40.65, $34.08, and $29.21 trillion, under high‐, moderate‐, and low‐development scenarios, respectively. And it also showed the population and economic size of each province across China under high‐, moderate‐, and low‐development scenarios. This study's WRCC‐based simulations can provide guidance for future policies related to water, population, and economics. Overall, contributions of this study include (1) a quantitative model related to freshwater security and water policies; (2) the model narratives that paint a better picture of China's future water security and socioeconomic development; (3) the conclusion that it is conducive to adjust water use rigid constraints with water policies; (4) an understanding that it is more intuitive to use population size and economic scale instead of dimensionless scores to characterize the state of WRCC. The WRCC model is instructive for the other counties or regions.