Manning’s roughness through the entropy parameter for steady open channel flows in low submergence

Entropy model application to river presents relevant aspects for theoretical and practical issues useful for cross section velocity distribution. The ratio between mean and maximum velocities is dependent on local branch morphology and remains quite uniform among similar location sections. Recent studies propose the formulation of Manning’s roughness, n, based on such ratio and the ratio between the positions where the velocity is zero and maximum, y0/ymax, but falling for low depth. Basing on steady flows experiences, the paper analyses the dependence of n on entropy parameter, M, for low depths, proposing an equation for y0/ymax knowing slope and submergence.