Assessment of Ecological Method for Slope protection

[[abstract]]傳統邊坡穩定工程－混凝土構造物，其表面平滑，生物難以附著生存，對環境衝擊甚大，且營建工程從材料取得、施工營建、使用維護、拆除解體到回收利用之生命週期中，各環節無不對地球環境產生衝擊，故以生態工法創造優質環境，遂為當前重要課題。道路邊坡工程生態工法須因地制宜，依災害發生類型及環境特性，採行最適當之對應治理機制。 本研究運用「層級分析法（AHP）」從事專家問卷調查，經統計分析並計算各決策層面及評估準則之權重作為道路邊坡工程生態工法之綜合評估的依據，即在維護道路邊坡安全性之前提下，分別就生態、環境、經濟等三個層面之效益作評估分析。每一層面均有四個評估準則，生態層面之評估準則為：綠化及植生復育、生物多樣性、土壤復育支出、保水性，環境層面之評估準則為：創造環境景觀特色、工程構造物最小化設計、環境調合度、公害防治支出，經濟層面之評估準則為：材料種類及費用（考量施工性）、最少土石方及土石資源處理、營建廢棄物減量、維護與管理成本。另收集山區道路邊坡工程採用生態工法的實際案例，以檢驗本研究所建立綜合評估方法的正確性，提供給決策者進行策略釐定之參考。[[abstract]]Traditional reinforced-concrete-based construction methods for slope protection have an adverse impact on the environment. Every phase of the life cycle of such methods, from production of materials, construction processes, to maintenance and eventual demolition, has unfavorable environmental effects. Therefore, using environment-friendly ecological methods has in recent years become an important issue. Selection of an appropriate ecological method for slope protection should be done according to the conditions and characteristics of each job site. This research carries out a questionnaire survey of experts’ opinions on evaluation criteria for ecological slope protection methods, and utilizes the analytical hierarchy process for deriving the weightage of the criteria as a basis for an overall assessment of a method under consideration. On the premise of structural safety, the assessment concerns achievements of a method in three categories of objectives, i.e. ecological, environmental, and economical and a total of twelve criteria are established. With respect to ecological objectives, they are green construction, bio-diversification, soil rehabilitation, and water-keeping ability. With respect to environmental objectives, the criteria are landscaping features, minimum engineering design, environmental adaptability, and minimum pollution. Regarding economical objectives, the criteria are cost of materials and constructability, minimum earthwork, reduction of construction waste, and cost of maintenance. Two case studies involving ecological methods for slope protection in road construction are used to illustrate the proposed assessment, and offer some suggestions for decision-making in relevant areas