摘要
黄河上游孔兑高含沙洪水经常造成其下游决堤、干流淤堵等洪水灾害,孔兑高含沙洪水具有峰高量大、含沙量高且陡涨陡落、持续时间短的特点。初步研究认为,孔兑高含沙洪水具有极强的输沙能力,当含沙量超过300kg/m3后,所需水流强度不再增加甚至有减少的趋势;当洪峰流量低于1 000m3/s时孔兑河道有冲有淤,断面的调整主要表现为主槽冲刷和滩地淤积;当洪峰流量超过1 000m3/s时河槽即可发生全断面的强烈冲刷,冲刷程度随洪峰流量增大而增大。孔兑泥沙进入干流后难以排出内蒙古河段,成为导致内蒙古河段淤积萎缩、排洪排凌能力下降的重要原因。
The hyper-concentrated floods from the ten tributaries emptide into the Inner-Mongolia Yellow River often cause dike break and channel plug in the lower reaches of the mainstream. The hyper-eoneentrated floods are characterized by high peak, large flood volume, high sediment concentration, sharp rising and dropping and short duration. The preliminary research shows the hyper-coneentrated floods of those tributaries have strong capacity in sediment transport. The flow intensity needed to transpdrt sediment does not increase with the sediment concentration, even to decline, when the sediment concentration is above 300kg/m3. When the flood peak discharge is below 1 000m3/s, sedimentation or scouring both can occur in the river channel. The adjustment of the cross-section is presented by the feature of scouring channel and silting floodplain. When the flood peak exceeds 1 000m3/s, the whole river bed can be scoured, and the larger the flood peak is, the stronger the ~eouring becomes. The sediment carried into the mainstream by the floods can hardly be transported out of the Inner-Mongolia Yellow River, and thus becomes one of the main reasons for the channel shrinkage and reduction in flood and ice flood discharging capacity of the Inner-Mongolia Yellow River in recent years.
出处
《泥沙研究》
CSCD
北大核心
2013年第1期67-73,共7页
Journal of Sediment Research
基金
国家重点基础研究发展计划(973计划)课题(2011CB403304)
"十二五"国家科技支撑计划项目(2012BAB02B03)
中央级公益性科研院所基本科研业务费专项(HKY-JBYW-2010-10)
关键词
孔兑
高含沙洪水
输沙能力
冲淤特性
ten tributaries
hypcr-eoncentrated flood
capacity of sediment transport
characteristics of scouring and silting
