圖書典藏及影音數位平台

分析台中海岸開發，對其周遭海岸影響程度，透過本計畫建立的評估方法，分別就各研究區域進行海岸變遷機制探討，並研提相關補償措施。

Taichung Coast is located between the mouths of Daan River and Wu River and has various and wide beaches. The length of Taichung Coast excluded the part of the Taichung Port is about 30 km. Taichung Coast does not suffer from four kinds of coastal disasters, which are storm surge, flood, beach erosion and land subsidence. Therefore Taichung coast is excluded in the list of the first-grade and second-grade coastal conservation zones according to the Coastal Zone Management Act (2016) of Ministry of the Interior. However, an analysis on the shoreline evolution along Taichung Coast during recent five years shows that four beaches ahead Wenliao No.4, Dingjunke, Haiwei and Nanzhuang seawalls are suffering from beach erosion to have potential zones in the future. Sequential bathymetric surveys on these beaches are suggested to ascertain whether continuing and severe beach erosion will occur in next five years. Based on the formula of the initial sediment transport and the sedimentary managements, the closure depth at -10 m is determined for the offshore boundary line of disaster potential maps and the levee road including side ditch is chosen as the land boundary line for Taichung Coast. There are four zones of first-grade coastal conservation, those are 1. Dadu estuary wetland, Dadu estuary wildlife refuge and Dadu river mouth major wildlife habitat; 2. Gaomei Wetland; Seven zones of second-grade coastal conservation include four artificial reefs at Songbo, Wujia, Taichung port No.1 and No.2; three conserve coral reefs at Daan No.1 and No.2, and Dajia. Any one of the first-grade and second-grade coastal conservation zones at Taichung Coast is excluded in the planned disaster potential maps. According to some acts for the coastal and wildlife conservation zones, third river management office, WRA has to acquire the central competent authorities’ permit before the dyke/seawall reinforcement or construction. Two wetlands of national importance at Taichung Coast are the Gomei wetland and the Dadu estuary wetland. Ministry of the Interior is the central competent authority for both wetlands. Taichung City Government is the only local competent authority for the Gomei wetland. Taichung City Government and Changhua County Government are the local competent authorities for the Dadu estuary wetland together. The wetland of importance conservation and utilization draft plans for the Gomei wetland and for the Dadu estuary wetland are proposed by Taichung City Government (2017). The draft plan for the Gomei wetland stipulates that the acts are banned within the borders of the wetland of importance. The structural construction for coastal protection, river improvement and flood-control and responsive disaster controls for dyke reinforcement and dredging in the ranges of alignment of levee, boundary line of proposed levee and river zone can be carried out after the central competent authorities’ permit and its copy of informing the local competent authority. According to draft plan for the Dadu estuary wetland, third river management office, WRA has to acquire the central competent authorities’ permit before the dyke/seawall reinforcement and fugitive dust control for hydraulic affairs and disaster controls. There are two wildlife conservation zones at the Gomei and the Dadu estuary, which overlap with the corresponding wetlands of national importance. The central competent authority of the two wildlife conservation zones is the Council of Agriculture, Executive Yuan and the local competent authorities are the same as those of two wetlands of national importance. Based on the conservation plan for the Gomei wildlife refuge declared by Taichung government, any act in the core area of the Gomei wildlife refuge is not permitted. The acts for flood control and seawall reinforcement within a 50m seaward range from Panzilia, Gaumei No. 1 and No. 2 seawalls are permitted.