台南海岸斷面測量監測計畫(1/2)(附光碟)

本計畫研究範圍為八掌溪口至曾文溪口海岸，沿岸長約35公里，海岸地形水深測量範圍原依契約規定係由急水溪口至曾文溪口（不包括港口及潟湖區）之臨外海側海岸段共約15公里，惟考量計畫完整分析地形水深變遷特性，以增測方式補足港口及潟湖區臨外海側範圍，測量岸線長約30公里。其研究目的係期望藉由相關基本資料蒐集分析、航拍或衛星影像岸線萃取、地形水深測量等調查工作，進行地形水深侵淤變遷特性分析、海岸結構物保全措施及將軍外海抽沙養灘之探討，作為日後海岸防護工作及環境營造計畫之參考依據。
本計畫蒐集八掌溪口至曾文溪口海岸與鄰近海域相關海氣象、海岸漂砂、河川水文、海岸地形及環境生態等基本資料，並逐項彙整其特性。
於2014年3月12、13日以及3月7~21日分別完成平面與水準控制點檢測。於4月12日~4月26日、9月25日~10月6日完成冬、夏季波浪作用後之地形水深測量工作，同時蒐集往昔地形水深監測資料，進行季節性與長期之地形水深平面與斷面侵淤分析，另蒐集早期海岸線資料，進行長期海岸線變遷分析。
海岸結構物保全措施成效檢討方面，已就現場海岸勘查結果說明本段海岸環境情形，並依據規劃海岸代表斷面，進行海岸平衡剖面分析；其次依各段之歷次地形水深資料，參照海岸防護結構物興建時間，分析海岸結構物影響區之地形水深土方量變化，檢討各段海岸結構物對地形水深之影響與功效。
另以波浪溯上水理模式進行現況海岸安全性檢討，依海堤重要性選擇重現期波浪條件，以海堤溯上不超越堤頂發生越波為準則，評估現況海岸可調整空間，配合現場海岸勘查結果提出現況海岸環境改善建議。
最後，蒐集相關海岸工程與海洋地質等之研究及文獻，初步探討將軍外海粗顆粒海床質外，就數值模式評估抽沙坑對近岸波浪之影響，並依據結果探討將軍外海抽沙養灘之可行性。

The investigated ambit of this project is from Pa-Chang River to Tsengwen River, with the length of 35 km, at Tainan City. The coast range topography bathymetry original is from Jishui River to Tsengwen River (not including the port and the lagoon area) off the coast side about 15 km. But considering plans to complete analysis of changes in water depth terrain features. Increase the measurement shoreline of about 30 km. The purpose of the research included basic data collection analysis, aerial or satellite images shoreline extraction, terrain bathymetry...etc. Complete terrain bathymetry erosion and sedimentation analysis, coastal Structures protective measures, discussion keep pumping sand beaches off Jiang-Jun coast. As future coastal protection and create a plan of environmental reference.
The plan collect basic information of tide, wave, current, coastal sediment, stream hydrology, coastal protection works, and environment ecology...etc, and aggregated its characteristics.
The seasonal bathymetric surveys at this coast had been performed in March to April and September 2014. Meanwhile, the previous data of bathymetric surveys were collected. With these data, the seasonal and long-term periodical evolutions of coastal erosion and accretion were analyzed. In addition, the early coastline data were collected to study the long-term periodical changing of coastline.
Additionally, as to the effects of existing coastal protection works, the representative coastal sections at this coast were selected firstly, according to the types of coastal protection work, bathymetric slope, and coastal environment. Then, the analysis of equilibrium profile and trend of onshore and offshore at each coastal section were estimated, and one dimension sediment theory. In order to understand the influence of existing protection plants on coastal erosion and accretion, the volume variations of previous bathymetric surveys at the influence ambit of breakwaters and groins were calculated and analyzed.
Furthermore, the safety of existing seawalls at this coast was evaluated by a run-up formula. Finally, the results of this project were used to provide a promising shore protection strategy.
Finally, the collection of marine geology and coastal engineering literature, explore the coarse particles of the seabed off the Jiang-Jun coast. Use numerical models to assess the impact pumping sand on the nearshore wave, and the feasibility of beach nourishment off the Jiang-Jun coast.