Geoscience Reference
In-Depth Information
slope is higher at the early stage and becomes lower with time. Fig. 9.15(a) compares
the simulated (solid lines) and measured bed profiles at 30 s, which are in fairly good
agreement. Figs. 9.15(b)-(d) show the simulated and measured overtopping flow dis-
charges, reservoir water levels, and erosion rates at the dam crest during a time period
of 200 s. The erosion process is predicted generally well.
In addition, the “turbid-water” model presented above is compared with the
traditional “clear-water” movable-bed model, in which the effects of sediment concen-
tration and bed change on the flow are neglected by setting
as the pure water density
and removing the third term in Eq. (9.59) and the fourth term in Eq. (9.60). Fig. 9.15
shows the simulation results of these two models for Run 2. It can be seen that the
“clear-water” model significantly over-predicts the erosion process. This proves that
the effects of sediment transport and bed change on the flow should be considered in
cases of strong sediment transport and rapid bed change.
ρ
