Multi-Criteria Decision Analysis: A Framework for Managing Contaminated Sediments

Abstract

Decision-making in environmental projects can be complex and seemingly intractable, principally due to the inherent existence of tradeoffs between sociopolitical, environmental, and economic factors. One tool that has been used to support environmental decision-making is comparative risk assessment (CRA). Central to CRA is the construction of a two-dimensional decision matrix that contains project alternatives’ scores on various criteria. The projects are then evaluated by either qualitatively comparing the projects’ scores on the different criteria or by somehow quantitatively aggregating the criterion scores for each project and comparing the aggregate scores. Although CRA is laudable in its attempts to evaluate projects using multiple criteria, it has at least one significant drawback. That drawback is the unclear or unsupported way in which it combines performance on criteria to arrive at an optimal project alternative. In the case of qualitative comparison of project scores using CRA, it can be unclear why an alternative is chosen if it performs better only on some criteria compared to another alternative. Quantitative CRAs are often unsupported in how they determine the relative importance of each criterion in determining an aggregate score for each alternative. Multicriteria decision analysis (MCDA) not only provides better-supported techniques for the comparison of project alternatives based on decision matrices but also has the added ability of being able to provide structured methods for the incorporation of project stakeholders’ opinions into the ranking of alternatives. In this paper, we provide