圖書典藏及影音數位平台

海岸地區因地勢低窪，排水能力先天上受到限制，常於颱風侵襲期間，因海水暴潮位抬升，內水難以順利排出致淹水災害，甚至海水位可能超過海堤防護高度，發生海水溢淹災害頻傳。近年氣候變遷下，海岸災害之程度與不確定性俱增加，故國際間多依照海岸災害特性，採取工程與非工程的調適手段，以降低海岸災害的損失。 為掌握氣候變遷對於臺灣海岸地區之影響，本署於99年～103年已完成臺灣地區氣候變遷海岸地區衝擊、風險評估及調適策略初步研擬。接續必需進一步評估調適策略於海岸高風險地區的可行性。爰成立本計畫，先指認氣候變遷影響下可能的高風險的海岸地區，再選擇案例地點評估調適方案可行性(含工程與非工程)，以為未來持續推動海岸地區氣候變遷調適方案之基礎。

The drainage capacity of coastal areas is usually limited due to its low attitude. During the invasion of typhoons, the seawater rises, sometimes higher than dikes, and flooding frequently occurs. In recent years, the extent and uncertainty of coastal disasters increase due to the climate change, and engineering and non-engineering means based on the characteristics of coastal disasters are often taken to reduce the loss of coastal disasters. In order to understand the impact of climate change on Taiwan's coastal areas, the Water Resources Department (WRD) completed a preliminary study on the impact, risk assessment and adaptation strategies of coastal areas in climate change in Taiwan from 2010 to 2014. Continued further assessment of the feasibility of adaptation strategies in coastal high-risk areas is necessary. Therefore, to identify possible high-risk coastal areas affected by climate change is the first task. Then, case sites are selected to assess the feasibility of the adaptation program, including engineering and non-engineering ones, as a basis for continually advancing the climate change adaptation program for coastal areas. The results of each task are as follows: 1. Collection and analysis of national and international coastal adaption information Influenced by global climate change, the disaster and erosion to coastal areas caused by waves and storm surges, etc. have been gradually noticed by governments and scientists. In order to control the impact of climate change on the coastal areas and the related adaptation strategies, the project collected national coastal hazard and coastal erosion related data from 2001 to 2015, and collected and analyzed the relevant data of national and international coastal area adaptation strategies. Also, national and international relevant case studies of coastal adaptation were gathered. 2. Identification of high-risk coastal areas of Taiwan under climate change and analysis of the land use According to the results of Taiwan coastal disaster risk analysis, the coastal high-risk areas of Taiwan are mainly concentrated on the west and northeast coasts. The coastal areas of Yunlin, Chiayi, Tainan, Kaohsiung and Pingtung have a considerable proportion of highest risky, rank of 5, areas. Considering the areas of high risk, the urgent needs for the implementation of the adaptation program are also higher. And, the land use of Taiwan’s high-risk coastal areas was analyzed. Considering the selected demonstration areas should be given priority to the highest risk coastal areas, the western coastal areas of Taiwan are low-lying, affected by gradual subsidence, and with series drainage problem. Yunlin and Chiayi coastal towns are serious subsidence areas and the relevant coastal calamity may have been relatively early. Also, they may have been relatively large hinterland for a variety of related engineering and non-engineering measures. It was therefore decided to take the Kouhu and Sihu townships in Yulin County and Dongshi and Budai townships in Chiayi County as demonstration areas. At the same time, according to the newest marine meteorological and human and social-economic conditions, the risk degree of Yulin and Chiayi areas should be reanalyzed in order to confirm the main factors of the disaster. 3. Assessment of the feasibility of adaptation programs for high-risk coastal areas This project assesses the feasibility of applying the adaptation action plan for high-risk coasts based on previous studies. Locations of assessment are firstly chosen based on the analysis results of the coastal disaster map of demonstration areas; evaluation of feasibility and effectiveness of the engineering/non-engineering adaption program is then taken; finally, a concrete and feasible adaptation plan based on the evaluation results is to be formulated. Adaptation program corresponding to risk adjustment strategy can be divided into two categories: engineering and non-engineering measures. Engineering methods correspond to risk control, and non-engineering methods correspond to risk transfer and risk avoidance. For the application of the timing, it is recommended to follow the protection design standards. In the event that the probability of exceeding the design standard is higher than the design standard, the engineering method (risk control strategy) should be adopted. In the event that the probability of exceeding the design standard is lower than the design standard, the non-engineering risk transfer and risk avoidance strategy should be adopted. 3.1 Evaluation of the feasibility and effectiveness of the engineering approach Based on the conditions of the demonstration areas, a total of seven concrete engineering methods were proposed, including a) Set up a flood-detention pond, e.g. wetland park b) Protect coastal erosion c) Prevent subsidence d) Strengthen, monitor and maintain the existing seawall protection e) Strengthen the drainage facilities behind the embankment f) Protect the coast with the concept of the second seawall 3.2 Evaluation of the feasibility and effectiveness of the non-engineering approach The suggested non-engineering methods are: a) Enhance sea level monitoring b) Establish a regional typhoon storm surge warning mechanism c) Assess the risk of complex coastal hazards d) Strengthen the release of disaster alert information pipeline e) Maintain natural coastal ecological environment f) Integrate management of coastal areas g) Plan disaster relief plans h) Implement disaster prevention education i) Set up coastal hazard insurance This project focuses particularly on coastal hazard insurance. In the past, the related research is less discussed. It is proposed as the main focus of the non-engineering methods within this project and its feasibility was to be assessed. 3.3 Proposed adaptation methods According to the aforesaid engineering and non-engineering adaptation methods, the proposed plans for the demonstration area are as follows: Engineering methods: a) Strengthen the floodgate facilities b) Strengthen the pumping facilities c) Refill the groundwater wells d) Enhance seawall safety Non-engineering methods: a) Strengthen the monitoring of sea water level b) Plan and set up detention pond c) Construct a risk map d) Strengthen the early warning information system, strengthen public education, and increase social adaptability e) Maintain coastal wetlands f) Establish coastal hazard insurance system g) Implement the integrated coastal zone management 4. Conducting a forum for relating experts, scholars and civil society (at least one) A forum for relating experts, scholars and civil society was held on November 4, 2011 to discuss topics of climate change adaptation program, and cross-agency cooperation mechanisms and supporting regulations, etc. The experts also made positive suggestions, and they were compiled into the comprehensive plan. 5. Suggestion of cross-agency cooperation mechanism and supporting regulations While seawalls are facilities belonging to WRA, there is no doubt that the WRA can set up maintenance and management facilities in accordance with the law. However, for non-engineering strategies of risk transfer and avoidance, in particular the coastal disaster insurance proposed in chapter 4, involve in the powers and responsibilities of other agencies. To successfully promote them, the competing relations among different agencies were analyzed and the cross-agency cooperation mechanism and supporting regulations were proposed.