Decision Support for Sustainable Water Resources Management in Singapore

Xi Xi

Abstract

In order to alleviate the risks of flooding and diversify Singapore’s sources of water supply, the country’s former Chief Defense Scientist, Professor Lui Pao Chuen, proposed an underground water storage system in 2012. This infrastructure could have significant long-term impacts on the integrated water resources system in Singapore. In addition, among the many alternatives to augment water supply, decision makers need to know which ones are the more sustainable plans to pursue.

This research proposes an integrated decision support approach that incorporates System Dynamics (SD) and a multi-criteria decision support tool called Analytic Hierarchy Process (AHP). It also demonstrates the usefulness of this innovative approach in helping to achieve sustainable water resources management in Singapore. First, a SD model takes in real-world data and simulates the consequences of different alternative plans under various scenarios. 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 priorities of development plans are: 1) seawater desalination; 2) NEWater (brand name for reclaimed water); 3) local water catchments; 4) underground water storage; 5) status quo. This thesis demonstrates that the integrated SD-AHP decision support approach is very useful and effective in the long-term planning for sustainable development.