Study on integrated allocation and dispatch model of water quality and quantity for the Yellow River

The synchronous coupling of water quality and quantity is a challenging problem for integrated water resources allocation and delivery. Using the section of the Yellow River from Lanzhou to Hekouzhen as the study area, this paper presents the coupling of water quality and quantity models through the application of decomposition, coordination, coupling, and control processes while using real-time data transmission and feedback techniques. The online identification and process control of allocation and delivery targets are obtained by using parameters such as water extractions, discharges, and water quality in different functional zones. An integrated model of allocation and delivery of water quantity and associated water quality is established to manage the river network. The model is characterized by a range of unique functions such as loop iterations, on-line feedback, and rolling updates. By extrapolating from the runoff sequence of 1956 to 2000, the water demand and drainage quantities in 2020 are estimated. Consequently, the scheme of integrated allocation and delivery of water quantity and resultant water quality for the Yellow River section from Lanzhou to Hekouzhen is proposed using model optimization control methods. The results indicate that the surface water consumption in 2020 for the upper section of Hekouzhen will be 12.52 billion cubic meters through the application of the coordinated control and rational allocation methods. This represents a reduction of 0.672 billion cubic meters compared with the estimated surface water consumption values in the "Eight-Seven Diversion Scheme" of the Yellow River. In addition, the loads of key pollutants, such as COD and ammonia nitrogen, entering the Yellow River are predicted to reduce by 50.6% and 65.7%, respectively. Overall, this integrated model allows for the optimization of water quantity and the water quality associated with it and their subsequent control in a range of functional zones.