A comparison of fuzzy logic and TOPSIS methods for landfill site selection according to field visits, engineering geology approach and geotechnical experiments (case study: Rudbar County, Iran)

Abstract

The present study evaluated and selected the best location among susceptible landfill sites in Rudbar County using 27 criteria, as the maximum effective criteria, in the decision-making process. The emergence and comparison between the two methods of fuzzy and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) with an engineering–geological approach have been conducted to obtain the best results. In this regard, inappropriate regions for landfill construction have been restricted after the conflation of two maps based on the restriction criteria. Then, the direction of prevailing winds and proper area for landfill construction was investigated for a 20-year perspective, and the regions that had more than 35-hectare area and were not located in the direction of the prevailing winds have been identified as responsive sites for landfill construction. Ultimately, selected susceptible regions were prioritized separately based on the TOPSIS and fuzzy methods. To ascertain the accuracy of the results and the reality of the resulted models, complementary field studies, geotechnical digging, and engineering–geological experiments have been used as verification parameters. According to the results of the verification, the fuzzy model having maximum matches with the verified data has been suggested for prioritizing susceptible regions.