A Novel Integrated Decision Support Tool for Sustainable Water Resources Management in Singapore: Synergies Between System Dynamics and Analytic Hierarchy Process

摘要

In order to alleviate the risks of urban flooding and diversify Singapore’s sources of water supply, an innovative idea of underground reservoirs was proposed. This infrastructure could have significant long-term impacts on the water resources system in Singapore. In addition, among various alternatives to augment water supply, decision makers need to know which ones are the more sustainable plans to pursue. This research proposes a novel integrated decision support tool that synergizes System Dynamics (SD) and a multi-criteria decision-making method called Analytic Hierarchy Process (AHP). First, a SD model takes in real-world data and simulates the consequences of different alternative plans under various scenarios of future population growth. Second, AHP is applied to compare different alternatives based on their performance as revealed by the SD simulation and the judgment of decision makers. Through the SD modeling we found that the proposed underground water storage system is not going to have a profound impact on Singapore’s adequacy and self-sufficiency in water, mainly because of its limited capacity and long construction time. Decision analysis through AHP reveals that if the population increases rapidly or mildly, then the order of priorities are: 1) seawater desalination; 2) NEWater (brand name for reclaimed water); 3) local water catchments; 4) underground water storage; 5) status quo. This novel integrated decision support tool, together with real-world data, could be applied to many other similar situations around the world in which policy makers need to make critical decisions with significant long-term implications, both in water systems and beyond.