Evaluation of contractor selection criteria with fuzzy AHP for sustainable sea dredging operations

Sea, coastal and wetlands are one of the most economically and socially important resources worldwide. These areas include the open ocean, nearshore areas, freshwater and saltwater junctions, and inland wetlands. However, over time, sand, mud and sediments accumulate underwater in these regions, destroying the structure of the seabed and reducing the water depth. This situation poses a great threat, especially to critical areas such as ports, canals and marinas. Therefore, it is vital to keep the depth of ports and marinas at certain levels; In this way, ship traffic can be maintained safely and marine ecosystems can be protected. Seabed dredging operations are carried out by public institutions and private dredging companies specialized in this field. The first and most critical step of this process is for businesses in need of dredging to select the appropriate contractor. In this study, contractor selection criteria for sustainable seabed dredging operations were evaluated using the fuzzy AHP method under the headings of economic, social and environmental sustainability. Four sub-criteria were determined under each main criterion and their pairwise comparisons were carried out by experts in a fuzzy environment. According to the study results, environmental criteria stood out as the most important element, followed by economic and social criteria. When all sub-criteria were evaluated together, environmental impact reduction was determined as the most important criterion with an importance weight of 25.6%; this was followed by waste management with 15.2% and energy efficiency with 13.5%, respectively. This study emphasizes to decision makers the importance of environmental criteria in contractor selection for sustainable dredging operations. Additionally, it has been shown that the fuzzy AHP method has been consistently and successfully applied in evaluating contractor selection criteria for sustainable seabed dredging operations.