Exploration on the Feasibility and Mode of the Whole River Water and Sediment Regulation in the Yellow River Basin

In the past decades，some progress has been made in the theory and practice of water and sediment regulation of the Yellow River．However，under the current engineering conditions, the feasibility and model of the whole river water and sediment regulation combined with the cascade reservoirs of Long ( Longyangxia) , Liu ( Liujiaxia) , Wan ( Wanjiazhai) , San ( Sanmenxia) and Xiao ( Xiaolangdi) are rarely discussed.  Based on a comprehensive analysis of the adjustable water volume of the Long-Liu cascade reservoirs, interval inflow and diversion water volume of the whole river under the multi-year average condition, this paper demonstrated the feasibility of the whole river water and sediment regulation under the current engineering conditions.  Two modes were put forward including the conventional mode and the unconventional mode, and the effects of two modes were compared and analyzed.  The results show that the sediment discharge of Xiaolangdi Reservoir under the two modes is 145.1 million tons and 191.3 million tons respectively and the sediment deposition of the downstream channel is 11.3 million tons and 22.1 million tons respectively.  No matter which mode of water and sediment regulation is adopted, Xiaolangdi Reservoir can achieve effective erosion in reservoir during the period of discharging before flood, and at the same time, it has little influence to the siltation of river channe.  Therefore, under the premise of strengthening the fine operation of the reservoir and strict interval diversion management, the whole river water and sediment regulation mode under the current engineering conditions is completely feasible.