Joint optimization of water allocation and water quality based on multi-objective control in Nanning, China

Abstract

Abstract Studying the change mechanism of water quantity and quality is the basis for joint optimization of water resources systems, which is a significant means for modern regional water resources management. A water quantity and quality joint optimization model is built based on multiple control objectives, which include water demand, observed flow rate, and observed pollutant concentration. A coupled water quantity and water quality model was developed for Nanning, China. The natural water cycle and social water cycle in Nanning City and the associated pollutant transport transformation process are simulated. The results indicate that simulation error of water resources allocation is below 5%, the Nash–Sutcliffe efficiency coefficients of the three hydrological stations are 0.85, 0.88, and 0.85 respectively, and the relative errors of the simulated results of three water quality monitoring stations are all within 1.83%, all of which indicates that the model performs well and the simulation results can reproduce the water use process and pollutant transport transformation process of Nanning in time and space. This study can provide effective support for water resources management in Nanning City.