Effects and Significance of Water and Sediment Regulation by Reservoirs in the Middle Yellow River

This paper describes chiefly water and sediment regulation with different operational modes subsequent to the re-construction of Sanmenxia reservoir, and analyses sedimentation in the reservoir and the lower river course. Regulation of sediment must be taken into account together with regulation of runoff. A certain storage capacity has been maintained for long-term use for multi-purpose developments of flood control, irrigation and power generation and for sediment conveyance in the lower river course as well through rational regulation of water and sediment in reservoirs built on middle reaches of the Yellow River. Reservoir operational modes for water and sediment regulation are also discussed in the paper.