| 摘要: | 由於新興繁榮的全球人口，全球化運動和氣候變化現象對水資源的壓力不斷上升；並且由於以上所有協同增效作用，更加推動了永續性水資源管理的緊迫性。小島嶼發展中國家（SIDS）的有限陸地上缺乏豐富的地表水體或大型地下水層，水資源短缺和壓力是更加嚴峻的。 貝基亞島具有共同的特色的小型沿海社區，反映出他們的脆弱和具有挑戰的水務部門。貝基亞島沒有地表儲水，僅有有限的地下水資源和易導致季節性缺水和乾旱般情況的氣候系統；因而島內幾乎是完全是依賴集雨的。然而，像這樣越來越強的乾旱強度和頻率增加形成了持續利用雨水作為供應的主要來源的阻礙。貝基亞島礙於面積狹小，也意味著社會經濟的可持續發展和水資源是相互依賴生存的，因而更進一步地突顯出及早確定可行的水資源策略的迫切需要。因此，為了符合水資源綜合管理的思想，本研究發展一種方法架構來為貝基亞島選擇一個可行的水資源供水策略，其同時也可以適用於各種小島嶼的環境中。本研究首次採用層級分析法（AHP）的多準則決策，根據經濟的權宜計算，社會的接受度，環境的完整性，可靠性和技術傾向的評價標準之下，做出一個優先次序模型來排名一套非傳統的供水來源；如：海底管道，海水淡化，雙管線制度和政府蓄水池計畫等。 至於偏好的選擇必須受到經濟的評估；在評估中，通過平準化水成本（LWC）的計算以測試水資源的競爭力，給予財政上的可行性進行了評估。最後，用此研究，透過一個利用不同策略的可行性調查,以及選擇水資源計畫的社會意識形態標準，以對應整體社會的期望。 在貝基亞島的預期選擇中，環境已被評計為一個非常高的價值。在層級分析法(AHP)中，利益相關者同意以環保優先標準的比重已達37.4%；而社群中也有30%以此為偏好標準，僅次於只有41%的以經濟標準為主。海水淡化從層級分析法(AHP)被選定為增加供水的最合適的選擇，是由於它的可靠性標準中的主導地位，並因為74％的社會群眾轉達了對他們對海水淡化的支持，這一策略的成功機會大為改善。計算每一立方米2.87美元的平準化水成本(LWC)，這種策略可說是具有成本競爭力。至於更進一步的經濟評估結果則表明，還有額外的好處可以得到；如：整體供水改善的結果也改善了與水有關的社會經濟標準和提供充足的消費使用。雖然海水淡化已被社會廣泛接受，面對島上的自給自足的供水歷史，我們仍必須給予認真的考量如何實施成本和能源策略。對於貝基亞島而言，有58％的社群明確的表示對於供水網規劃管理的支持，以緩解未來水資源短缺和水資源市場風險的社會經濟挑戰，都是存在於現實的。The strain on water resources is escalating owing to burgeoning global population, globalization and climate change; all of which acts synergistically to impel the urgency of sustainable water resource management. With limited landmasses, which do not allow for extensive surface water bodies or for large underground water storage, water scarcity and stress is more profound for small island developing states (SIDS). Bequia Island exhibits many features common to small coastal communities that reflect their fragile and challenged water sector. Bequia has no surface water reserves, limited groundwater resources and a climatic regime which results in seasonal water shortages and drought like conditions. The island rely almost exclusively on rainwater harvesting, however, increasing intensity and frequency of this drought like condition acts as an impediment to the continued utilization of rainwater as the primary source of supply. The diminutive size of Bequia means that sustainable socio-economic development and water resources are interdependent, further highlighting the exigent need to identify early feasible water augmentation strategies.Conforming to the ideologies of integrated water resource management, this study develops a methodological framework to select a feasible water augmentation strategy for Bequia, and one that can be applicable to the context of various small islands. The research first employed multi-criteria decision making with emphasis on the Analytic Hierarchy Process (AHP) as a prioritization model to rank a set of non-conventional sources such as submarine pipelines, desalination, dual distribution system and a government cistern project, under the evaluation criteria of economic expediency, social acceptance, environmental integrity, reliability and technical propensity. The preferred alternative was then subjected to an economic assessment where the financial viability was evaluated by calculating the levelized water cost (LWC) to test the competitiveness of the water resource. Finally, the research maps the social desirability of the community through a survey by eliciting the likelihood of success of different strategies as well as society’s ideologies of criteria selection for selecting a water project.The environment has been credited a very high value in project selection for Bequia. In the AHP analysis, stakeholders awarded the environmental criterion precedence with a weighing of 37.4% while 30% the community specified their preference for this criterion, second to the economic criterion of only 41%. Desalination was selected as the most suitable alternative to augment the water supply from the AHP analysis, owing to its dominance in the reliability criterion, and as 74% of the community conveyed support for desalination, the chance of success for this strategy is improved. A calculated LWC of US $2.87 per cubic meter indicates that this strategy can be cost competitive. Further economic assessment indicates that there are additional benefits to be derived such as: improved access to water resulting in improvement in water related socio-economic standards and sufficient availability for consumption. Although desalination is widely accepted among the community, careful consideration must be given in implementing this cost and energy demanding strategy given the history of self-supply water on the island. The prospect of mitigating water scarcity and its socio-economic challenges by venture of a water market is realistic for Bequia as 58% of the community articulated their support for a regulated water supply network. |
