ZHANG Jinliang, HU Chunhong, LIU Jixiang

Abstract: This article systematically summarized the development process of the operation mode of reservoirs on sediment-laden rivers in China since the 1950s, especially explained the operation mode and design technology of "storing clean water and regulating muddy flow". The operation mode of "storing clean water and regulating muddy flow" develops the traditional sediment-retaining mode of “retaining coarse sediment and discharging fine sediment” with low backwater into diversified utilization of sediment-retaining storage capacity and synchronous shaping of floodplain and channel of "low flow to block sediment, high flow to discharge sediment, timely peak generation, floodplain silting and channel forming". The operation mode has changed the traditional sediment-retaining mode of silting without flushing. During the normal operation period, the utilization of water-sediment classification scheduling supplemented by unconventional sediment discharge scheduling can achieve coordinated water-sediment relationship reconstruction and sediment-retention storage capacity regeneration. On the basis of maintaining the effective storage capacity of the reservoir for a long time, the application of "storing clean water and regulating muddy flow" further takes into account the needs of the reservoir for water-sediment regulation, effectively avoids the occupation of the effective reservoir capacity due to sedimentation, reduces the adverse impact of the forced sediment discharge of the reservoir on the downstream water-sediment relationship, which is the inheritance of the application of “storing clean water and regulating muddy flow” and the overall development of “water and sediment regulation”. In terms of design technology, in order to better meet the needs of sediment regulation, it is required to scientifically and rationally design the corresponding discharge scale of the sediment regulation capacity and the sediment discharge water level, consider the different siltation states during the sediment regulation process, and design the reservoir capacity configuration according to the reservoir capacity distribution design of " deep channel for sediment regulation, medium channel for benefit and high channel for flood regulation”. Rivers with ultra-high sediment content should set abnormal sediment discharge bottom outlets below normal flow and sediment discharge outlets to form a "normal + abnormal" double sediment erosion datum plane. Reservoir should adopt water and sediment separation development method in rivers with super high sediment content, which is difficult to coordinate effective reservoir capacity maintenance and water supply regulation. The results will provide guidance and reference for the reservoir engineering design and operation of sediment-laden river, in the current and future periods.

Keywords: Yellow River, reservoir sediment, water storage and sediment interception, storing clean water and discharging muddy flow, storing clean water and regulating muddy flow, operation mode