High-efficiency sediment-transport requirements for operation of the Xiaolangdi Reservoir in the Lower Yellow River

• Published in: Water science & technology. Water supply Vol. 22; no. 12; pp. 8572 - 8586
• Main Authors: Chen, Cuixia, Fu, Jian, Wu, Moxi, Gao, Xing, Ma, Liming
• Format: Journal Article
• Language: English
• Published: London IWA Publishing 01.12.2022
• Subjects: Agricultural production; Discharge; Downstream; Efficiency; flood event; Floods; Fluvial sediments; lower yellow river; Mathematical models; Outflow; Precipitation; Reservoir sedimentation; Reservoirs; river channel scouring; river channel silting; Rivers; Scheduling; Sediment; Sediment concentration; Sediment load; Sediment transport; sediment transport efficiency; Sedimentation & deposition; Volume transport; Water flow; Water levels; Water resources; xiaolangdi reservoir; China; Yellow River
• ISSN: 1606-9749; 1607-0798
• DOI: 10.2166/ws.2022.397

Abstract Sediment accumulation is severe in the Lower Yellow River. Improving sediment-transport efficiency is an important way to save water resources. In this study, we analyzed the sediment-transport efficiency at different sediment concentrations and discharge levels using data from 306 non-overbank floods in the lower reaches of the Yellow River from 1960 to 2016. When the sediment concentrations were below 20 kg/m3, 60 kg/m3, and greater than 100 kg/m3, the clear water volumes for transporting sediment were above 50 m3/t, approximately 16 m3/t, and less than 10 m3/t, respectively. Given current scheduling, the Xiaolangdi Reservoir can lower its water level and increase non-overbank large water flows with an outflow discharge of >3,000 m3/s when the incoming water flow has a sediment concentration of >60 kg/m3. Mathematical modeling indicates that, for an incoming sediment load of 600 million tons in the Middle Yellow River, the average sediment-transport water volume at the downstream Huayuankou Station decreased by 27%, Optimized scheduling at the Xiaolangdi Reservoir could reduce the sedimentation in the downstream channel by 1.1 billion tons more than current scheduling, and extend the reservoir's sediment-trapping period by ten years. These findings can be applied widely in sandy rivers.