圖書典藏及影音數位平台

海岸開發行為若未整體考量，將改變當地波流特性及輸砂機制，進而影響位於其上下游側海堤防護設施安全，爰此有必要就此探討已受影響之海岸段，釐清其影響機制，並建議配套補償措施，以利整體海岸穩定。

Constructing defenses to against coastal flooding began at 1960s in Taiwan. With increasingly protection work, the life and property of coastal residents were fairly protected, which indirectly contributed to the prosperity in coastal regions. Subsequently, pitfalls due to large scale coastal exploitation, for example, coast erosion, land subsidence, and urbanization lead increasingly coastal hazard potential. This study focused on the effect of coastal erosion around or nearby coastal defense structures induced by the developments of industrial, commercial, and fishery harbors. Those construction projects were found to disturbed the continuity of littoral sediment transport and lead to the retreat of the shoreline on the downstream area. The intruding marine energy increased with the eroded amount within the continental shelf that causes the protection defenses damage or degradation. Conflict arose between government departments and stakeholder for who should take the responsibility and how large was the area affected by the structures. The legal basis was weak that the strategies of Integrated Coastal Zone Management (ICZM) are hard to implement. Upgrade or reinforcement of coastal defense structures to against increased marine loadings refer to engineering strategy was the only option. However, it was not always the proper solution with respect to the consideration of the sustainable use. Situation changed after the “Coastal Zone Management Act” of Taiwan was passed in Feb. 2015 that the integrated management strategy was asked to proposed. The responsibility of the coastal defense within the affected region caused by the development behaviors were clarified in the Act. This study used coastal zone around Taipei and Taitung Coasts as case studies, and the main coastal development are Taipei Port, Linkou power plant and extension breakwater structures, and Fugang fishery harbor. Trend analysis are used to assess the effects of the coastal exploitation on the coastal defenses. Trend analysis used the historical satellite images, maps, and bathymetric survey data to analyze the evolution of coastlines. After the analysis of terrain changes, it was confirmed that the two coastal development facilities in the coast of Taipei caused imbalances in sand transport and siltation, while the Fugang fishery harbor on the coast of Taitung did not.The results of the trend analysis of Taipei Port showed that (1) the amount of sediment erosion is about 70,000 m3, and the area of influence is about 2 km in the north of the north outer breakwater. (2) the amount of sediment erosion is about 150,000 m3, and the area of influence is about 2.5 km in the south of the south outer breakwater. Also, the results of the trend analysis of Linkou power plant and extension breakwater structures showed that (1) the amount of sediment erosion is about 70,000 m3, and the area of influence is about 1.5 km in the north of the outlet diversion dike. (2) the amount of sediment erosion is about 550,000 m3, and the area of influence is about 2.5 km in the south of the outlet diversion dike.As far as the status of the coastal protection in Taipei is concerned, the safety protection standards are met, which means there is no need for improving construction at the present stage. Based on the assessments, the engineering measure of beach nourishment planning and non-engineering measure of land use control were proposed for the sustainable use. The relevant government departments and stakeholder within the coast area were also investigated.