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題名 | 颱風巨浪侵襲下沙質海岸緩衝帶寬度之預估=Estimation of Storm Buffer Width for a Sandy Beach |
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作 者 | 李芳君; 許榮中; | 書刊名 | 海洋工程學刊 |
卷期 | 13:1 2013.03[民102.03] |
頁次 | 頁15-29 |
分類號 | 443.1 |
關鍵詞 | 暴浪型海灘剖面; 海灘剖面模擬; 海岸緩衝帶; 濱臺侵蝕幅度; 沙洲位置; 海岸防護; Storm-built beach profile; Modeling beach profile changes; Storm beach buffer width; Extent of berm; Retreat; Location of offshore bar; Shore protection; |
語文 | 中文(Chinese) |
中文摘要 | 以海岸防災與防護觀點而言,海灘必須有充裕的寬度,才能避免颱風暴潮巨浪對後灘公共設施的破壞及保護居民生命財產安全。這種由海灘灘線至後灘濱台受波浪掏刷所需的海灘寬度,稱為颱風侵襲時之「海岸緩衝帶寬度」。本研究在不考慮全球暖化及海水面上昇對已達到平衡剖面與濱台高度的影響下,應用SBEACH模擬結果顯示:(1)當海堤前無海灘或寬度不足時,無法抵禦颱風巨浪侵襲,導致堤趾被刷深或海灘完全消失;(2)若有充裕的寬度,不論是天然或人工養灘所造成,雖濱台在短時間內遭侵蝕後退,仍有餘地保護後灘的安全;(3)在相同的波高及週期條件下,沙灘中值粒徑D50愈小者,剖面坡度較緩,必須規劃寬廣的海灘,且在後灘濱台的設計高程為暴潮設計水位的1.6倍時,方能有效消減颱風巨浪的能量,達到海緩衝帶寬度的功效。由本研究所得之多變數迴歸式,輸入波浪條件及沙灘D50,可估算濱台刷深深度與侵蝕幅度及海岸緩衝帶寬度。 |
英文摘要 | On the basis of coastal disaster mitigation and protection, a beach must have sufficient width for preventing the destruction to public facilities, as well as protecting the safety of life and private property during storm events. The requirement of such horizontal extent from the initial shoreline to the probable erosion landward to safeguard against the onslaught of a storm is referred to as ‘storm beach buffer width’. Upon neglecting the effects of global warming and sealevel rise on a beach that has a profile in equilibrium, our modeling results using SBEACH reveal that: (1) A seawall without or with insufficient fronting width would result in serious scour at its toe and even the total loss of the entire beach berm; (2) A beach with sufficient berm, natural or artificially nourished, is capable of protecting the back beach, despite the temporary erosion in the early hours of a storm action; (3) Under the same conditions of wave height and period, a wide buffer is necessary for a beach with small mean sand grain D50 , and the berm height should be designed at 1.6 times of the designed storm surge level, in order to effectively absorb storm wave energy and maintain the provision of a storm buffer; and (4) A multiple linear regression model is proposed in this study which can be used to evaluate the scour depth and retreat of the berm, as well as the width of a storm beach buffer, upon the input of wave conditions and mean beach sand grain D50. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。