Comparison of AHP and TOPSIS methods in municipal solid wastelandfill site selection of Songhor County

: Site selection is an important and necessary issue in waste management especially in fast-growing regions. Due to the landfill is a common solution for the final disposal of municipal solid waste in Iran, this study was carried out for MSW landfill site selection of Songhor Township by combining the geographic information systems (GIS), the analytical hierarchy process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS).

In the current research, ArcGIS 10.2 software and its extensions were used as the GIS tool since there is able to perform suitability analysis using multi-criteria evaluation. Also, to identify appropriate landfill areas in the Songhor Township, eleven criteria including slope, geology, hydrology, fault, drainages, distance from transportation routes and rails, distance from protected areas, land use, population areas, distance from groundwater resources and distance from urban areas were evaluated. Then a final map was generated which identified the suitability regions for MSW landfill sites establishment.

Based on the results obtained, 4.2% of the study area was most suitable, 33% was suitable, 17.8% was poorly suitable, and 45% was unsuitable for sanitary disposal of solid wastes of Songhor Township.

Since the AHP has relative ease of handling multiple criteria, and on the other hand, has potential to easy understand and effective handling of both qualitative and quantitative parameters, therefore, use of AHP is suggested as an efficient method to prioritization of suitable areas for landfill site selection. In other words, the AHP is a powerful tool for solving complicated problems that may have interactions and correlations among multiple objectives.