圖書典藏及影音數位平台

分二年度進行枋寮漁港至枋山溪，以及枋山溪至楓港溪二段海岸之基本資料蒐集、水深地形測量、潮波流與海域底質調查、海岸水動力數值模擬及海岸線變遷分析等。

This project is divided into two years. The main propose of first year (2017) is to investigate the coastal area between the Fang-Liao fishing port and estuary of Fang-Shan river, while the shoreline is about 14 kilometers long. The coastal area investigated in next year (2018) is from the Fang-Shan river south to Feng-Gang river, which is about 9 kilometers long. Besides collecting of historical data and in-situ measuring, long-term shoreline analysis and numerical simulations are also applied to analyze the changes of coastal environment. Furthermore, the stability of seawalls and safety of life and property are discussed, and the assessments of design improvement about seawalls and breakwaters will also be evaluated in this project. The work contents include: (1) basic data collection analysis, (2) topography survey and analysis, (3) the tidal-wave-current analysis, (4) the seabed sediment characteristics analysis, (5) analysis of coastal changes (6) seawalls and offshore breakwaters performance evaluation. Land and sea topography and depth measurement were executed in April and October in 2017. The results show some erosion at land side in the area of Jialutang and Nanshihu coasts, while the erosion depth are between 0.2 m and 1.0m. At sea area, the sand bar near Fanzilun and Bao-Sheng village tends to moving toward to land side. By historical meteorological and oceanographic data analyzing, results show that the maximum tidal level was +0.89 m; the minimum tidal level was -0.67 m; the maximum tidal range was 1.41 m (Fang-Liao tidal station, observation time during 2017/06/06 ~ 2017/10/25). During the measuring time from 8th June to 13th July 2017 (1st observation), analysis of wave data shows that the major wave directions are SW and SSW; the significant wave height (H1/3) is 116.5 cm, and the corresponding significant wave period (T1/3) is 5.86 sec. The main surface current directions are SE, SSE and NW, which are parallel to the coastline, and the current speed is about 0 ~ 25 cm/sec high. While during the 2nd observation (from 27th September to 30th October 2017), the major wave directions are WNW and W; the H1/3 is 86.6 cm, and the corresponding T1/3 is 6.22 sec. The main surface current directions of 2nd observation are also SE, SSE and NW, and the current speed is about 0 ~ 25 cm/sec high. The result of long-term shoreline analysis shows most of the shoreline remain stable in project zone. Due to the shoreline shape and estuary sand transport, the north side of Fang-Shan River changes obviously. Assuming bedload particle size was uniform and seasonal wind wave effect was the only force, the one-line model was established. The simulation result shows the estuary of Shuai-Mang River and Fang-Shan rest area has the tendency of erosion; others remain stable or slightly accretion. Two-dimensional numerical simulation for coastal terrain in Pingtung coast: After winter monsoon wave effect, the bathymetry is stable. After summer monsoon wave effect, the major deposit areas are in the southern coast of Fang-Liao fishing port, Jialutang coast and the northern coast of Fang-Shan river. The other coast that the erosion takes place in nearshore and deposit in offshore. After 50-year-period typhoon wave (SW wave direction) effect, the erosion takes place in shore and deposit in offshore. The sediment transport capacity direction is from south to north. After one year wave effect, the major deposit areas are in the southern coast of Fang-Liao fishing port and the northern coast of Fang-Shan river. The other coast that the erosion takes place in nearshore and deposit in offshore. To protect the coastal area and avoid beach erosion, some protection strategies are planned in this project according to the in-situ surveying and assessment. The slope type protection is suggested to reduce the erosional downcutting and damage to the toe of seawalls in Jia-He and Fang-Shan coastal zone, where the erosional effect is much more significant.