頁籤選單縮合
題名 | 單一透過堤背後海岸線變遷之研究=Shoreline Changes Behind a Single Permeable Breakwater |
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作者 | 許泰文; 張憲國; 徐立政; | 書刊名 | 中國土木水利工程學刊 |
卷期 | 9:3 1997.09[民86.09] |
頁次 | 頁473-481 |
分類號 | 443.1 |
關鍵詞 | 離岸堤; 沙舌; 繫岸沙洲; 海岸線變遷; Detacded breakwater; Salient; Tombolo; Shoreline changes; |
語文 | 中文(Chinese) |
中文摘要 | 往昔學者大多使用一維單線模式預測海岸結構設置後之海岸線變遷,由於結構物附近之近 岸流場具二維性,一維模式難以描述流場與漂沙運移特性,其適用性常受限制。本文提出單線半海 岸線變遷模式,用以計算單一透過離岸堤背後之海岸線變化。文中先引用非定常緩坡方程式解析波 高分佈,由波高分佈計算近岸流場,再結合輸沙濃度計算堤後海岸變遷。本模式亦經前人之試驗結 果校核,結果顯示預測值與實測值頗為吻合。本文同時探討不同透過率、離岸距離、波浪條件等因 素對堤後沙舌形成之影響,計算結果顯示沙舌形成與離岸堤距離與堤寬比值有關。文中並由計算結 果迴歸堤後沙舌形成之經驗式,在固定波浪條件下,本文結果與前人迴歸式相符。 |
英文摘要 | Previous one-line models that fail to show two-dimensional variations of nearshore circulations are limited to predict shoreline changes behind detached breakwater. A one and half-line model is proposed to simulate shoreline changes behind a single breakwater based on nearshore currents and sediment concentration. The unsteady mild-slope equation has been applied to the propagation of waves in the present case. Waveinduced nearshore currents are predicted from governing equations that incorporate the radiation stresses. The model is verified through available experimental data and comparison shows favorable agreement. The salient so formed has an apex whose location is dependent upon the ratio of the length of the breakwater to its distance offshore. Forcing parameters, such as wave steepness, distance of the breakwater offshore, and porosity, which affect shoreline changes are discussed. The predicting equations are obtained from the regression analysis on the basis of numerical results. The present results are consistent with previous results in the limiting case of constant wave conditions. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。