| Summary: | 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.
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