Author(s): Ana Maria Ferreira Da Silva; Andrew D. Binns
Linked Author(s): Ana Maria Ferreira da Silva
Keywords: Meandering streams; Bed development; Erosion deeps and deposition hills; Time of development
Abstract: A method for the quantitative evaluation of the time of bed development in alluvial meandering streams is sought. In agreement with the prevailing approach, it is assumed that the stream centreline follows a sine-generated curve; the banks are rigid. The flow is turbulent and sub-critical, and the width-to-depth ratio is “large”. The movable bed is flat at time 0=t; at bTt =, the bed reaches its equilibrium or developed state. With the aid of dimensional and physical considerations, an expression is proposed for the duration of bed development bT. According to this expression, bT is proportional to the square of the flow width B and inversely proportional to the channel-averaged bed-load rate. The proportionality factor is found to be a function of the initial deflection angle 0θ alone. The present efforts of the authors to reveal this function are outlined.