Numerical modeling of sediment transport in coastal environments

Summary

Numerical modeling is a cost effective tool in the coastal zone management. A properly developed and calibrated model can predict the coastal processes in an efficient manner and therefore, adequate engineering measures may be taken in order to secure human life and property.

A hydrodynamic model comprising of shallow water equations coupled with a morphological model (developed by Environmental Hydrodynamics Research Group, Tohoku University, Japan) was applied to a field situation of heavy flood at Natori River mouth located near Sendai city, Japan. Using a fine grid the qualitative comparison with aerial photograph showed a close agreement for the sediment transport characteristics. The flow profiles were predicted and compared with the existing measured data of water level. The model prediction was successful in the estimation of water level. The ability of this model to predict sediment movement was shown by comparing computed and measured cross-sections in the channel.

Figure 1 shows the comparison between computed and observed water levels at a gaging station in Natori river. The flood hydrograph and tidal elevations were used as upstream and downstream boundary conditions, respectively. It may be observed that the model performs very well in predicting the water levels.

Figure 1. Water level at Yuriage station