Waste Management and Research 31(1) 98–105 © The Author(s) 2013 Reprints and permission: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0734242X12456092 wmr.sagepub.com Introduction Disposal of wastes through landfill is an inevitable element of all solid waste management systems. Even if all activities for reduc- tion, reuse and recycling are implemented, there will always be a need for land disposal of a residual proportion of the waste pro- duced originally. Sanitary landfill is the most common and popu- lar method of solid waste disposal used in many countries, including developing countries (Yesilnacar and Cetin, 2005). One of the most difficult tasks faced by most communities in planning solid waste landfill is finding suitable sites for new landfills (Rushbrook and Pugh, 1999; Tchobanoglous et al., 1993). The appropriate site selection for waste disposal is a com- plicated process because it must combine social, environmental and technical factors (Kontos et al., 2005). In order to consider all factors in the landfill siting process, geographic information sys- tems (GIS) is a powerful tool because of its ability to manage large volumes of spatially distributed data from a variety of sources. It efficiently stores, retrieves, analyzes and displays information according to user-defined specifications (Sener et al., 2006; Siddiqui et al., 1996; Wang et al., 2009). In the land- fill siting process it is necessary to rank suitable sites and choose the best one in the next stages. To overcome this problem we can use an analytical hierarchy process (AHP). The combination of GIS and AHP is a powerful tool to solve the landfill site selection problem because GIS provides efficient manipulation and presentation of the data, and AHP supplies con- sistent ranking of the potential landfill areas based on a variety of criteria (Sener et al., 2006). A decision modeling procedure was developed, based on the AHP, to locate nuisance facilities (Erkut and Moran, 1991). Municipal solid waste landfill site selection with geographic information systems and analytical hierarchy process: a case study in Mahshahr County, Iran Nadali Alavi 1,2 , Gholamreza Goudarzi 1,2 , Ali Akbar Babaei 1,2 , Nemat Jaafarzadeh 1,2 and Mohsen Hosseinzadeh 3 Abstract Landfill siting is a complicated process because it must combine social, environmental and technical factors. In this study, in order to consider all factors and rating criteria, a combination of geographic information systems and analytical hierarchy process (AHP) was used to determine the best sites for disposal of municipal solid waste (MSW) in Mahshahr County, Iran. In order to the decision making for landfill siting a structural hierarchy formed and the most important criteria: surface water, sensitive ecosystems, land cover, urban and rural areas, land uses, distance to roads, slope and land type were chosen according to standards and regulations. Each criterion was evaluated by rating methods. In the next step the relative importance of criteria to each other was determined by AHP. Land suitability for landfill was evaluated by simple additive weighting method. According to the landfill suitability map, the study area classified to four categories: high, moderate, low and very low suitability areas, which represented 18.6%, 20.3%, 1.6 and 0.8% of the study area respectively. The other 58.7% of the study area was determined to be completely unsuitable for landfill. By considering the parameters, such as the required area for landfill, distance to MSW generation points, and political and management issues, and consulting with municipalities managers in the study area, six sites were chosen for site visiting. The result of field study showed that it is a supplementary, and necessary, step in finding the best candidate landfill site from land with high suitability. Keywords Landfill, site selection, GIS, AHP, Mahshahr County 1 Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2 Department of Environmental Health Engineering, School of Public Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 3 Khuzestan Water and Power Authority (KWPA Co.), Ahvaz, Iran Corresponding author: Ali Akbar Babaei, Department of Environmental Health Engineering, Ahvaz Jundishapur University of Medical sciences, Golestan Blvd., Ahvaz, 61357-1575, Iran. Email: babaei-a@ajums.ac.ir 456092WMR 31 1 10.1177/0734242X12456092Waste Management and ResearchAlavi et al. 013 Short Report