Abstract:
In hydraulic engineering, flow resistance coefficient (Manning roughness coefficient) is one
of the important parameters. It helps in flow forecasting in the channel, designing of
hydraulic structures, the calculation of the distribution of velocities and sediment transport.
So, the entropy velocity distribution requires the assessment of one parameter, M and this
suggests to investigate the dependence of the entropy parameter on the hydraulic and
geometric characteristics of the river cross section (Moramarco and Singh (2010)). Such
studies, derived from the entropy velocity theory, proposed the formulation of the Manning’s
roughness, n, based on Ф(M) and the positions in which the velocity is hypothetically zero,
y0, and maximum, ymax, respectively.
Experimental investigations on laboratory flume have been conducted to collect precise data
on different discharges and at different bed roughness through a channel section and
corresponding velocity distribution along several verticals with depth to apply the concept of
entropy theory for calculating the entropy parameter which can be used to estimate the
manning’s roughness.
Work was carried out on Laboratory flume in the Watershed Laboratory of the Department of
Hydrology, IIT Roorkee under controlled conditions. Roughness coefficient taken using
conventional techniques, have been simulated for same conditions using Entropy model
proposed by Tommaso Moramarco and V. P. Singh (2010). The results were found to have in
good correlation with corresponding observations which validates the formulation relating
Manning’s roughness to Entropy parameter
