Physical modeling applied to the calibration of the Manning's coefficient for simulations of sedimentation in reservoirs

Abstract

When reservoirs are built, they are subject to some degree of sedimentation. This happens because the increase in wetted area reduces the flow velocity. As a result, the sustaining forces of sediments are diminished. One mechanism to assess reservoir sedimentation is through physical models, which provide data for numerical models. One of the parameters that needs to be input into the numerical model is the Manning coefficient. Thus, the aim of this study was to calibrate the Manning coefficient for a reservoir. For this purpose, a reduced model of a Small Hydroelectric Power Plant (SHP) was utilized. Manning values were set in the HEC-RAS software, and flow depths were simulated. These were then compared with those obtained from the reduced model. The best value found for the Manning coefficient was 0.01. This value allowed for depths measured in the reduced model to closely match those simulated in HEC-RAS. Furthermore, the flow exhibited the same behavior in both real and simulated cases.