都江堰凤栖窝河段淘淤规律研究

都江堰的运行模式从“深淘滩、低作堰”的古制到现在基本不淘淤,其根本改变具有重要的社会和经济效益。本文分析了凤栖窝河段淘淤的规律性,得出:内江河段卵石的临界起动流量为200m3/s;凤栖窝淘淤对该河段的水位流量关系没有直接的影响;卧铁断面平均河床高程的冲淤变化主要受内江流量和河段内卵石运动的影响,淘淤的持续效应不长;内江流量大于400m3/s或涨水过程中以冲刷为主,而在流量小于400m3/s或降水过程中则以淤积为主;外江闸和飞沙堰闸的运行是凤栖窝长期不淘淤的前提条件。

Study on the digging load in Fengqiwo reach at Dujiangyan

From the deeply-digging and low-weir in the past to almost no-digging in the present,the essential change of the administration mode of Dujiangyan has important social and economic values.From the law of the digging load in Fengqiwo river,it is concluded that the critical discharge of gravel bed-load in Neijiang river is 200m~3/s;the digging action in this river section has no direct effect on the relationship of flow depth and discharge;the erosion and deposition of river bed at Wotie section are mainly influenced by the discharge and the gravel motion in Neijiang river,the river bed is maily eroded when the discharge in Neijiang river is larger than 400m~3/s or the flow discharge is rising;whereas the river bed is deposited;the basic conditions of no-digging for a long term in Fengqiwo is the running of Waijiang Gate and Sand-flying-weir Gate.