Spatial Scale Based Yellow River Water and Sediment Regulation

The theory of spatial scale based Yellow River water and sediment regulation is to use the combination of different sluicing tunnels and openings of the Xiaolangdi Reservoir to create discharge and sediment concentration with a certain duration and volume and particle gradation process of sediment, load to “the clear water” of the Yiluohe River and Qinhe River located on the downstream of the Xiaolangdi Reservoir, accurately link up that at Huayuankou Hydrometric Station, form balanced relationship between water and sediment at Huayuankou Station and realize the objectives of not only releasing the silted sediment in the reservoir, but also avoiding deposition in the lower channel of the Yellow River. During the period of September 6～18, 2003, Yellow River Conservancy Commission conducted prototype tests on the theory. The results shown that a) it has reached the goal of retaining coarse sand and releasing the fine and slowing down reservoir siltation at early stage of sediment retaining function of the Xiaolangdi Reservoir by utilizing the characteristic of sediment release by density flow and reservoir muddy water;b) to wash the released fine sand from the reservoir into the sea without increased deposition in the lower river channel by utilizing flood resources of Xiaolangdi-Huayuankou reach, increasing the sediment delivery efficiency; c) to realize the integration of sediment reduction and hazards reduction of the lower reaches; d) to store water source for water diversion from the Yellow River to Tianjin Municipality and farmland irrigation in the next year by storing 602 million m 3 of water in the Xiaolangdi Reservoir.