根據Meyer & Taylor (1972) 的研究指出，有限振幅淺水法理論可以描述波浪之溯升. 本研究依此理論利用顯性Lax-Wendroff 的有限差分法模擬波之溯升; 再由所模擬的結果配合底床質運移之經驗公式，並假設溯升及其回降(Uprush & Backwash)並不相互影響彼此之輸沙能力.分別就不同的波高， 週期及海灘坡度，討論前灘區沖蝕量的大小與波浪尖銳度的關係，並與Sunamura (1984) 的實驗結果比較。 另外，模擬一振盪水流在沙灘面上往復振盪，探討沙灘地形因水流特性而變化的情形，並討論波浪尖銳度與沙洲的關係。 The sedimentation in the swash zone is one of the most vigorous and complicat phenomenon in nature. Since the first erosion always occurs in the swash zone, the sedimentation in this area is very essentia l to beach erosion. In spite of its importance, the studies are not many due to its nonlinear character and the difficulty of its measurment. In addition, the durat i on of storm is a key factor to the safty of the beach area. Once the rate of erosion can be calculated, then we may predict how safe the beach area is. In the light of these reasons, a preliminary numerical model was developed. Though the research on the sedimentation in the swash zone is very little, the wave run-up problem has been modelled successfully, Hibberd & Peregrine(1979) . Therefore we use their numerical scheme to determine the flow factors, water velocity and depth as a function of time and space . Then we implanted a sediment model to simulate the sedimentation. In this early stage, we assume the sediment will not affect the flow situation which may be considered in the future studies . We use different bore heights, beach slopes, and wave periods to see the effects on the rate of erosion in the swash zone. We also simu l ate the formation of a bar and the influnces of the wave steepness on the geometry of the bar are also examined .
關聯:
第十三屆海洋工程研討會論文集=Proceedings 13th conference on ocean engineering in R.O.C.，頁537-555
