Landfill Site Selection Using Multi-Criteria Decision Making: Influential Factors for Comparing Landfill Locations

Abstract

Landfilling stands as the final phase in the continuum of solid waste management, serving as a complement to various disposal methods. In Iran, only 8% of municipal waste is recycled, composted, or reused, while a staggering 92% is sent to landfills. Of this 92%, approximately 25% is disposed of properly and hygienically; the remaining waste is buried unsafely and piled up chaotically. Landfill sites pose potential risks to human health and the surrounding environment, making the selection of these sites a critical process that must be approached with caution. The factors influencing landfill site selection are numerous and the process itself is complex. Despite extensive research focusing on energy recovery and the recycling of valuable materials from waste to alleviate the pressure on landfills, landfilling remains an integral component of solid waste management.

Sanitary landfill operation management involves several key steps: selecting a suitable site, preparing the site, and executing engineering operations at the landfill. The first step in landfill design is the selection of an appropriate site. When choosing a landfill site, several factors are typically considered, including site topography, site geology, regional hydrology, meteorology, required land area, cover soil type, groundwater level, landfill characteristics, nearby land uses, distance from surface water, land price, landfill site lifespan, soil permeability, soil stability, flood susceptibility, lithology, stratigraphy, presence of faults, type of land use, location of the site relative to urban development, proximity to residential and urban areas, proximity to cultural and protected sites, wind direction, access to roads and railways, proximity to construction materials, location of powerlines and pipelines, and proximity to airports.

The present research investigates various methods used for selecting landfill sites with an emphasis on multi-criteria decision-making approaches (multi-criteria decision analysis (MCDA)). The investigations identify the following as the most frequently used methods: grey systems theory, ordered weighted averaging (OWA), weighted linear combination (WLC), analytic network process (ANP), fuzzy-analytic network process (F-ANP), analytic hierarchy process (AHP), fuzzy-analytic hierarchy process (F-AHP), TODIM, and fuzzy TODIM.