塑造和维持黄河内蒙古河段中水河槽对策

Countermeasures for Shaping and Maintaining Middle Flood Channels in Inner Mongolian Reach

河套灌区是黄河流域引水灌溉最多的河段,1986年以来由于水沙条件变化和人类活动的影响,该河段河道严重萎缩,防洪防凌形势严峻,引起管理部门高度重视。在研究内蒙古河段河床演变与水沙变化的响应规律基础上,得到以下主要认识:①内蒙古河段洪水冲刷效率较低,冲刷1t泥沙约需要180 m3水,建议该河段塑槽治理可通机械挖槽结合水库调节洪水冲刷实现。②维持内蒙古河段中水河槽需改善当前不利的水沙条件,基本途径依靠南水北调西线工程增加汛期水量,加大支流水土保持投入力度减少入黄沙量。

Water-delivering volume of the Hetao Irrigation District is the largest one in the Yellow River Basin. Since 1986, the middle flood channel has been shrunken badly while the position of flood and ice-flood prevention become severe, because the incoming water and sediment vary. It has attracted administrative departments＂ attention. Based on studying the response relationship between the evolution of river beds and variation of flow and sediment in Inner Mongolian reach, countermeasures for shaping and maintainning middle flood channels in Inner Mongolian reach is put forword. It needs 180 m^3 water to scour It sediment in Inner Mongolian reach. Because of poor efficiency, it is suggested that to shape the middle flood channel mechanical dredging should be combined with reservoir adjustment floods. To maintain the middle flood channel in Inner Mongolian reach, the current disadvantageous incoming water and sediment conditions have to be improved. The basic way is to depend on South-to-North Water Transfer Western line project to increase the flood season water volume. On the other hand, increasing soil and water conservation in tributary basin to reduce the sediment entering the Yellow River is eqally important.