An Integration of Interval Type-2 Fuzzy Set with Equitable Linguistic Approach Based on Multi-criteria Decision Making: Flood Control Project Selection Problems

Flooding is a big issue of widespread concern. Flood control project selection is needed to overcome the flooding phenomenon while achieving other objectives such as decreases the global burden of morbidity, mortality, social and economic disruptions, and stress on health services. Hence, the preferences of Decision Makers (DMs) from diverse backgrounds are needed to obtain the best project. However, flood control project selection faced high levels of conflict. Therefore, we propose a new equitable linguistic scale that provides an inclusive evaluation from integrating DMs’ preferences and opinions. Besides, we also propose a hybrid averaging approach of linear orders; consists of type-reduction method, ambiguity method and (Elimination and Choice Expressing Reality) ELECTRE-based non-outranked method by the new linguistic scales for Interval Type-2 Fuzzy Technique for Order Preference by Similarity to Ideal Solution (IT2FTOPSIS) method. An actual case experiment to evaluate seven different flood control projects is carried out in Malaysia based on the evaluation from the Department of Drainage of Irrigation agencies. The result shows that Dikes (levees/embankment)/Channel improvement/Diversion schemes are the best flood control project. Besides, this proposed IT2FTOPSIS can offer a measure of the DMs’ opinions and preferences. Correlation values have also proved that this proposed IT2FTOPSIS in line with the DMs’ decision compared to existing IT2FTOPSIS.