Characteristics of Sediments Distribution near Estuary of Cho-Shui River in Taiwan

摘要

The characteristics of sediment transport occurring in thenearshore region are mainly produced by the interaction of thecoastal morphological evolution and nearshore hydrodynamicsfrom waves, wave-driven-currents and tidal currents. In thisstudy, we discussed how various seasonal marine conditions caninfluence the characteristics of sediment transport in spatial andtemporal with filed observations near the estuary of Cho-ShuiRiver. The spatial distribution of grain size is decreasingalongshore from the estuary during summer, and is decreasingoffshore from shoreline but no significant changing alongshoreduring winter. Comparing with the numerical simulation withDHI MIKE-21, it shows that sands banked up at estuary causedby an excess of river sediments transport with smaller grain sizein summer, and that estuarine erosion results from the interplayof less river sediment transport supplied and hydrodynamicforcing scoured with larger grain size by waves in winter. In thispaper, the different characteristic associated from seasonalmarine conditions, river sediment transports, and estuarinemorphologies have been discussed, and the influence of typhoonalso analyzed.