A laboratory study on the erosion rate of coastal dune on a

• Main Authors: Lin, Chen-Thi, 林振旭
• Other Authors: I-Chen Lin
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/67735925091649548105

碩士 === 淡江大學 === 水資源及環境工程學系 === 85 === The coast has been shocked by the fatal force of the nature and the the sedimentation then showed complicate geomeorphic process. The incident waves on a sandy sloping beach will change the beach profile due to the sedimentation. A laboratory tests are performed in order to study the quantities of dune erosion due to attacks of different wave conditions.By using the flume experiment, we examined the dune erosion and the sedimentation on the single slope. The sediments were transported from the offshore to the foreshore region in according to the wave showered propagation. The dune were eroded when waves collide dune. That makes the dune back. As waves backwash, some eroded sand was carried offshore and some were stored in front of the dune. The topography was changed by the action of these waves. In the beginning,thesandy slopping beach topography was changedintensively beacause of the waves attack. As the test duration is elapsed, the equilibrium beach may has been reached. We will find the quantities of the sedimentation and the eroded dune for different wave heights, dune locations and wave periods. The waves height and the dune location are the most important. The waves height and the dune location are the most important. The wave period has less important influence on the rate of dune erosion. The effects of different dune locations on a sloping besch are also investigated. The comparison and discussion between the former results of Chern''s(1995)numerical scheme and Tsou'' s(1994)laboratory tests are studied and discussed by a geographic graph. The relation between wave steepness and the steepness of sand bar has also been also discussed.