Using systems thinking to study the coordination of the water–sediment–electricity coupling system: a case study on the Yellow River

Joint operation of the Longyangxia and Liujiaxia reservoirs (Long-Liu operation) is of great significance for water and sediment regulation in the Yellow River. The water–sediment–electricity coupling system is a giant system with complex nonlinear relationships. A reliable Long-Liu operation scheme facilitates maximization of the benefits of the water–sediment–electricity system. Based on systems thinking, this paper quantitatively evaluated the reliability of different Long-Liu operation schemes and coordination of the water–sediment–electricity coupling system through the entropy weight method and dissipative structure model. The results indicated that the current operation scheme is more reliable than the adjusted scheme at the inter-annual scale and during the summer-autumn flood season and ice flood season within a year. However, the operation scheme should be improved during the spring irrigation period. The key factors influencing the quality of the water–sediment–electricity system include the outflow of the Liujiaxia reservoir, incoming sediment load into the Yellow River at Toudaoguai, sediment inflow-outflow difference in the Ningxia-Inner Mongolia Reach, water flow at Lanzhou and power generation upstream of Toudaoguai. The water–sediment–electricity system under the current Long-Liu operation scheme is more coordinated than that in the adjusted state, but the overall coordinated development of the system remains at a low activity level.