长江中游沙卵石河段坡陡流急现象成因及对策研究(Ⅰ):发展趋势探析  

Investigation on water surface profile in the gravel bed reach of the middle Yangtze River:its current state and evolution trend

作　　者：孙昭华[1] 李义天[1] 李明[1] 张为[1] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《泥沙研究》2007年第5期9-16,共8页Journal of Sediment Research

基　　金：国家973项目(2003CB415200)

摘　　要：采用近期实测资料,以芦家河浅滩为重点,探讨和分析了长江中游沙卵石河段内枯期坡陡流急现象的成因、影响因素及发展趋势。结果显示:局部河床形态对水位存在控制作用,是造成较大集中落差的主要原因;在关键控制段河床形态稳定的前提下,局部滩槽冲淤难以使坡陡流急程度发生趋势性的变化;下游河床冲刷及水位下降后,坡陡流急现象的加剧不仅是局部比降的增大,更主要的是由一点扩散为多点,或由较短距离发展为较长区间。Based on data obtained from prototype and those produced by numerical model, the phenomenon of steep slope and high flow velocity during low flow season in some locations in the gravel bed reach of the middle Yangtze River is studied. With the case of the Lujiahe shoal reach, the study indicated that certain pivotal reach segment with special geological and morphological features is the main reason of the knickpoint on water surface profile. Because of the uneven scour depth in streamwise direction in the ongoing channel adjustment initiated by the Three Georges Dam, the phenomenon of high slope will become more serious： the higher gradient at the same position compaired with pre-dam period and the longer reach segment dominated downstream channel degradation and water level lowering, the latter will by high gradient and large velocity. be major changes in this reach.

关 键 词：沙卵石河段 坡陡流急 芦家河浅滩 

分 类 号：TV147[水利工程—水力学及河流动力学]