Prediction of water resource carrying status based on the ‘three red lines’ water resource management policy in the coastal area of Jiangsu Province, China

Abstract Recently, the Chinese government has issued various policies to regulate water resource management. The ‘three red lines’ policy is one of the most important. To quantify the influence of the ‘three red lines’ policy on water resource carrying status (WRCS), analyze the shortcomings of the current water resource management and provide support for adjusting the direction of water resource management, we constructed a system dynamics model that considered ‘red line’ constraint feedback and simulated changes in WRCS characterization indicators from the period 2019 to 2040 in coastal cities of Jiangsu Province. The WRCS in Nantong city from 2019 to 2035 was medium and that from 2036 to 2040 was poor; that in Yancheng city from 2019 to 2037 was medium and that from 2038 to 2040 was poor; that in Lianyungang city from 2019 to 2036 was medium and that from 2037 to 2040 was poor. We then constructed three schemes with strategies to improve the WRCS. Compared with the initial scheme, Scheme I, involving further enhanced water resource utilization efficiency and reduced discharge of pollutants, improved the WRCS. Based on Scheme III, the economic scale can be expanded by increasing economic development at an appropriate speed, while the WRCS remains almost consistent with the initial scheme.