Author(s): Ana Maria Ferreira Da Silva; Andrew D. Binns
Linked Author(s): Ana Maria Ferreira da Silva
Keywords: Meandering streams; Bed development; Time of development
Abstract: Dimensional and physical considerations are used to develop an expression for the duration of bed development of alluvial meandering streams. In agreement with the conditions in natural meandering streams, it is assumed that the flow is turbulent, sub-critical, and the flow widthto-depth ratio is “large”. The centerline of the streams is assumed to follow a sine-generated curve. The resulting expression gives the duration of bed development as proportional to the square of flow width and inversely proportional to the specific volumetric bed-load rate corresponding to the channel-averaged flow. The proportionality factor is found to be a function of only the initial deflection angle of the stream (i.e. the stream sinuosity). This finding is independently supported by the available laboratory data, however scarce. Future research is needed to reveal the not yet known function of the initial deflection angle (the proportionality factor), and eventually establish an equation that could be used in practical applications to predict the bed development time of alluvial meandering streams.