The computed results for flows are calibrated on the base of data measured in Thuan An station in April 1999. The final results from sediment transport model showed that the near shore area from Thuan An to Tu Hien are strongly affected by sediment transport process and the natural flow could change the morphological bed for very long time. | Vietnam Journal of Mechanics, NCST of Vietnam Vol. 23, 2001, No4 (193 - 204) NUMERICAL SIMULATION ON MORPHOLOGICAL PROCESS FOR TRUAN AN COASTAL AREA Huu CHUNG Institute of Mechanics 264 Doi Can, Hanoi, Vietnam DANG ABSTRACT. The 2DH model is developed and applied to evaluate sediment transport and bed level change in the coastal zone in central Vietnam. The model took the influences of waves and wind into account. Three different options for the flows with or without wind and two wave regimes are calculated. The computed results for flows are calibrated on the base of data measured in Thuan An station in April 1999. The final results from sediment transport model showed that the near shore area from Thuan An to Tu Hien are strongly affected by sediment transport process and t he natural flow could change the morphological bed for very long time. 1. Introduction Vietnam is a country with the coast length of more than 3200 km and usually affected by erratic changes of the weather. Hence, the study on the natural mobility law is really necessary. Owing to the features on bathymetry and shoreline, under the action of current and wave a great quantity of sediment appears in the estuaries and coastal areas. A part of it will settle onto the sea bed and the other will be carried away by current and assymetric waves. Many complicated physical processes occur at this stage between suspended sediment and sea bed. The experimental results by Dang Huu C. and Grasmeijer; Grasmeijer, ., Dang Huu C., Van Rijn . showed that transport rate due to wave is a considerable part in the total transport rate. Especially, in the case of a storm this is the most important factor for erosion and deposition. Moreover, owing to the action of current and waves the bedload transport also takes a significant part and it is evaluated by mathematical formulae. Sediment transport will affect kinematic regime of flows and it could cause serious and long lasting problems to the economical .
