channel roughness

channel roughness

[′chan·əl ‚rəf·nəs]
(geology)
A measure of the resistivity offered by the material constituting stream channel margins to the flow of water.
References in periodicals archive ?
where, nc is channel roughness coefficient, Sci is mean ith order channel slope; Bi is width of ith order channel and hcoi is in-flow depth of ith order channel due to water transported from upstream reaches.
Given data for the shape of the cross section, the gradient, and the channel roughness, the Manning equation can be applied.
Three methods were used to develop a family of curves representing stable channel dimensions under a variety of sediment supply conditions: "method one," which, over a hydrologic period, yields the net accumulation of sediment within a design reach; "method two," which can be used to estimate amounts of down-cutting or deposition expected for short- and long-term evaluations; and the "SAM method," which partitions channel roughness between the channel bed and banks, and uses resistance and sediment transport formulae to compute stable channel dimension curves.
Channel roughness can also be noted from the shape of the channel bottom and what appears to be a small shrub growing in the channel.