A Numerical Simulation of Onshore-Offshore Sediment Transport

• Main Authors: Shi-Ming Tang, 唐世民
• Other Authors: I-Chen Lin
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/72510177676120898122

碩士 === 淡江大學 === 水資源及環境工程所 === 82 === The incident waves on the beach and subsequent uprush and backwash change the beach profile，due to the sedimentation. This study is to develope a numerical model to calculate the onshore-offshore sediment on a sandy beach,which includes hydrody- namic model and sedimentation model. Meyer & Taylor (1972) pointed out that the shallow water wave theory can adequately simulate the wave uprush phenomenon.Using Hibberd & Pereg- rine (1979)'s numerical model which is based on the shallow water wave theory this study developed a numerical scheme to simulate the phenomenon of wave uprush & backwash process can only be modelled by the idea of Ho & Mayer(1962), who have found that the major backwash mechanism was based on the free falling motion.The wave runup on a sloping beach is thus being simulated. As for the sedimentation model,the concept of total load developed by Bagnold(1966) is used.this numerical model has also taken into consideration of the changes of the beach profile.The wave is periodic and the sand grain is uniform.An equilib- rium beach can be found by the simulating result. The relation between erosion rate and bar steepness has been studied. The effects of some important parameters on the sedimentation on this sandy beach are also considered.