A methodological overview on municipal solid waste landfill siting (a case study: Tehran; Iran)

Abstract

Numerous efforts have been made to increase landfill diversion rates through solid waste recycling. However, despite these initiatives, landfilling remains the dominant method of waste disposal. Selecting the appropriate site for municipal solid waste landfill is a critical environmental and public health issue, especially in developing countries. This complex problem encompasses environmental, economic, social, and legal factors. The aim of this study is to evaluate the most effective multi-criteria decision-making methods for identifying the optimal MSW landfill site in Tehran province. A geographic information system database was first created, incorporating 21 criteria and 6 constraints. The criteria were then standardized and weighted using the analytical hierarchy process (AHP) and the best–worst method (BWM). Suitability maps were generated using four different combination methods: ordered weighted averaging (OWA), technique for order of preference by similarity to ideal solution (TOPSIS), combined compromise solution (CoCoSo), and weighted aggregates sum product assessment (WASPAS). This approach resulted in 16 land suitability maps for MSW landfill sites in Tehran province, with site values calculated at a 95% confidence interval. These sites were further assessed using the rapid impact assessment matrix (RIAM), a conventional environmental impact assessment tool. Ultimately, the weighted linear combination (WLC) method proved to be the most suitable, providing the optimal site selection with a moderate risk-taking rate (0.5) and the highest trade-off rate (1).