圖書典藏及影音數位平台

台灣地狹人稠，隨著社會、經濟、人口快速成長，海岸地區已成為國土利用上不可或缺之空間。台灣因位於西太平洋颱風盛行區，夏秋之際常遭暴潮巨浪侵襲，沿岸低窪地區海水倒灌災害頻仍，為保障沿海居民生命財產安全，早期以興建海堤、離岸堤及拋置消波塊等硬式結構物加以防護，並未對海岸生態環境多加考量，無意中對海岸地區的生態及環境景觀造成影響。隨著近年來國內對生態環境保護意識抬頭，海岸防護思維除考量防災、減災外，亦逐漸將生態、景觀、親水及遊憩等需求納入。以營造一個豐富而多樣的水岸環境，落實生物多樣性保育，同時達成行政院「整體海岸永續發展」目標，求得人類與自然環境間之平衡和諧，降低人類活動對周遭生態環境影響。 而本署在海岸防護的觀念及措施亦隨時代演進有新的作法，在近期的「海岸環境營造計畫」，則融入整體環境考量，以達成「消減海岸災害、防止國土流失」、「改善海堤景觀、復育海岸環境」及「因應氣候變遷、創造永續海岸」的目標，同時改善早期一般性海堤缺點，儘量減少混凝土化之人工結構物，著重採用自然材料的生態工法。惟一般性海堤改善策略相關斷面佈置較因地制宜，在評估波浪溯上特性時，以往經驗公式恐無法完全適用，需進一步透過模型試驗檢視各海堤改善策略削減波浪能量特性，供規劃設計時參考。 爰此，本計畫將分3年就北區、南區及東區各海岸環境特性，擇選適宜且有代表性之海岸斷面型態，進行一般性海堤斷面改善前後特性試驗，藉由實驗室量測之波浪溯上資料，評估及率定適用之溯上公式，提供未來其他海堤改善時參考。

The basic principles of this study is to revise general coastal dikes by using 2-D physical modeling. Thus, the total study last for three years which therefore contains the whole region of Taiwn by dividing it into three domain, which is, the south region, the north region and the east region. And with this division, the first year report will be as well started as the south region. Firstly, by surveying widely for the south region’s coastal data, background informations and the dike-diagrams it was withdrawn out a typical dike formation for the south region as for to Zen-Wen sea dike and Fan-Zi-Lun sea dike. Base on both dikes locally, are defined as safety cases, which thence here should be more keen space for senic and attractive issue. While Zen-Wen sea dike locates on the northern side of Zen-Wen river, the Fan-Zi-Lun sea dike is situated on the northern part of Fang-Liao fishery port, and by these two, it represent both two different typical types of formation for the south region’s (which is for mild sea-bed and for steep sea-bed). In additions, Fan-Zi-Lun sea dike also has offshore breakwater which is quite a typical type for shore defence in Ping-Tung county or Kaohsiung. The experiments were carried out in National Chun-Kung University –Tainan Hydraulic Lab. with a scale of 1/25. Five of the revising cases on Zen-Wen sea dike therefore are: A(I) A displace of armor unit by adding triangle-concrete block strips (hight 1m, width 1m) between +3m and +5m. A(II) A displace of armor unit by adding extra rock fill up to +5m (to form a 1:5 rock slope). A(III) Adding extra soil layer covering on the original rubble mound section in between, through the armor unit to the dike’s top (+5m). A(IV) Same amount of rubble mount displacement (for A(II) ) but by substitute it by extending on the dike’s toe. A(V) Combining both A(II) and A(IV) together by doubling twice the rubble mount volume. Above all, the results show that case A(V) to be the best while A(II) and A(IV) are the next. On the other hand, Fan-Zi-Lun sea dike’s four revising cases are: B(I) Turning the offshore breakwater into submerged breakwater by extending twice the length. B(II) Changing the offshore breakwater‘s top three layer porosity by substituting it into other kind of armor unit. B(III) Taking the sea dike’s armor unit off the original case. B(IV) Extending the submerged breakwater nearly 4 times the length. And, finally, the results show that case B(IV) got the highest point, while case B(I) and B(III) are the next, and finally, B(II) is the least.