Brief Note – Inception of Channelization Over a Non-flat Bed
Brief Note – Inception of Channelization Over a Non-flat Bed
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简要说明——非平床上渠道化的开始
DOI：
10.1023/a:1010577228873
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发表时间：
2000
期刊：
影响因子：
2.7
通讯作者：
L. Ridolfi
中科院分区：
文献类型：
--
作者：
R. Revelli;L. Ridolfi
本文将Izumi和Parker[1，2]发展的平板流动的上游驱动理论推广到非平板情况。在Izumi和Parker理论的基础上，利用线性摄动分析对浅水深度平均的St.Venant方程进行积分，以得到对应于初始盆地之间的距离对河床曲率的有限波长的变化。采用河床冲刷门槛的概念[3]，目的是将超过临界剪应力与渠道水头位置联系起来。分析表明，即使对于较小的床曲率，特征波长相对于平床也有很大的变化。特别是，向上凹陷的床导致特征波长的增加，这似乎更符合真实值[4，5]。
The upstream-driven theory for inception of channelization developed by Izumi and Parker [1, 2] for a flow on a flat bed is here extended to the case of a non flat bed. Following the Izumi and Parker theory, the depth-averaged St. Venant equations for shallow water are integrated using a linear perturbative analysis in order to obtain the variation of the finite wavelength corresponding to the distance separation between incipient basins on bed curvature. The threshold concept for bed erosion [3] is used with the aim of associating the excedance of the critical shear stress to the channel head locations. The analysis shows that even for small values of the bed curvature there is a great change in the value of the characteristic wavelength with respect to the flat bed. In particular, an upward concave bed causes an increase of the characteristic wavelength that seems to better match real values [4, 5].