摘要
通过建立河道水沙仿真系统模型,系统的模拟了天然状态下宁蒙河道泥沙的输移过程,并与现状条件下该河段泥沙输移过程进行比较.结果表明:龙羊峡和刘家峡水库建成运行后,由于水库拦蓄作用,宁蒙河段入口下河沿站1969-2003年累计减少输沙量25.9966×108t,说明上游梯级水库的蓄水拦沙作用显著地减轻了宁蒙河段的淤积过程.宁蒙河段的淤积主要原因是青铜峡水库和三盛公水利枢纽建成蓄水抬高了坝前水位,致使坝址上游河段河道比降减小,河流挟沙能力显著降低,河岸风沙的加入以及当地支流产沙突发性加入、宁蒙河段用水量不断增加,以及青铜峡、三盛公水库小水排沙等多重因素所致.人们不可能从根本上改变河流以及区间支流流域的自然特性,只能通过对治理沙源、疏浚河道、修筑堤岸的措施治理宁蒙河段,减缓或改善其淤积速率.
Through establishment simulation system model of water and sediment runoffs,the sediment transport in the Ningmeng reach under nature condition can be systematically simulated and compared with the observation.It is found that after the Longyangxia and Liujiaxia reservoirs completing,owing to the retaining effect of the upstream reservoirs,the sediment through the Xiaheyan Station of the reach reduced 25.9966×108 t in total from 1969 to 2003,showing that the blocking sediment function of the reservoirs is obvious.However,water dammed by the Qingtongxia reservoir and the Sanshenggong water gate results in water level rising in front of the two structures and river surface gradient decreasing and then the sediment transport capacity of water obviously reduces.Resulting in the sediment transport capacity decreasing is enhanced by the following factors： sand drifting from river banks,increasing water consumption in the reach and low effective desilting from the Qingtongxia reservoir and the Sanshenggong water gate.It is impossible to change the properties of the river and its tributaries fundamentally,however,through controlling sediment sources,dredging up riverway and building embankments,the sedimentation rate in the reach can be slowed down.
出处
《冰川冻土》
CSCD
北大核心
2011年第2期416-424,共9页
Journal of Glaciology and Geocryology
基金
中国科学院知识创新工程重要方向项目(KZCX2-YW-328)
国家自然科学基金重点项目(90702001)
国家自然科学基金项目(931468093)资助
关键词
河道水沙输移
仿真分析
过程比较
黄河宁蒙河段
water and sediment runoffs
simulation analysis
process compare
Ningmeng reaches of the Yellow River
