A closeness coefficient-based multiple criteria decision-making method using interval type-2 fuzzy sets and its application to watershed site selection

The use of interval type-2 fuzzy (IT2F) sets can appropriately address imprecise or uncertain decisions in fields that require multiple criteria decision analysis. This paper develops a closeness coefficient-based decision-making method within the IT2F environment. The concept of approximate positive and negative ideals is proposed to provide an intuitive and computationally feasible approach to identify the closeness coefficient based on interval type-2 trapezoidal fuzzy numbers. Considering the issue of anchor dependency, we compare weighted evaluative ratings between the alternatives and the approximate positive and negative ideals. We then present a closeness coefficient-based procedure for handling multiple criteria decision-making problems and determining the order of priority of the alternatives. The feasibility and applicability of the proposed method are illustrated with the practical problem of watershed site selection. Additionally, a comparative analysis with respect to displaced ideals or fixed ideals is conducted to validate the effectiveness and applicability of the proposed method.