Risk-cost optimization under uncertainty for dredged material disposal

Disposal of contaminated dredged material may pose risks to ecological and human populations. These risks are highly uncertain. Measures to confine the dredged material and reduce these risks are likely to increase disposal costs. Risk and cost assessments for dredged material management alternatives often are associated with very large uncertainties. These uncertainties must be explicitly incorporated into risk-cost analysis to ensure that appropriate management alternatives are selected. However, considering these uncertainties may cause difficulties in decision making by making management alternatives effectively indistinguishable. A risk-cost analysis methodology that evaluates uncertainty directly in the decision framework is developed. A multicriteria decision-making method that incorporates uncertainties using fuzzy set theory is proposed to trade-off risks and costs (including uncertainties) so that disposal alternatives can be compared and selected.