Investigating the generalizability of the results obtained from laboratory models to natural rivers for estimating the head-discharge curve

Researchers have performed many Experimental and theoretical studies to estimate river-stage-discharge curves using the manning roughness coefficient. In natural rivers, in flood conditions, with increasing flow rate, water flows out of the central canal through the floodplains, thus the shape of the river and roughness coefficient change.

In this research, nine laboratory models and six natural rivers data were used to examine the accuracy of different Divided Channel Methods, DCMs, of rivers’ stage-discharge formulas to calculate the roughness. The cross section of rivers along the route would change significantly, therefore, the method with the least sensitivity to cross-sectional shape changes has the more generalizability. In the process of this research, the Manning coefficient was calculated using different methods and various laboratory data.

After reviewing the results of the different DCM methods, SC-SEV, SC-SIV, SC-SIH techniques were found as the less sensitive methods to cross-sectional changes to determine the roughness coefficient.