A qualitative decision support for environmental impact assessment using fuzzy logic

In environmental impact assessment (EIA), experts produce conclusions not only according to scientific data but also political factors and social values. Subjective judgment plays a significant role in EIA. Traditional multi-criteria decision-making methods cannot provide best decision support because they are incapable of modeling qualitative human thinking process. On the other hand, fuzzy logic is widely recognized as a tool with the ability to compute using words to model qualitative human thinking processes in the analysis of complex systems and decisions. This study attempts to utilize fuzzy logic as a decision-support approach for EIA. The evaluation knowledge represented by ‘if-then’ fuzzy rules is employed to measure the significance of environmental impacts. In this paper, 10 indicators and 28 subindicators are considered in the assessment framework using the Taiwan High-Speed Rail System as the case study.