evaluation of optimum areas for municipal landfill sites using ahp and anp in gis: a case study

this paper is aimed at applying integration of geospatial information system (gis) and multi-criteria decision making (mcdm) methods as a tool in a manner in which ignoring environmental, economic, scientific and engineering judgment is avoided. firstly, utterly unsuitable areas are excluded to promote the efficiency and accuracy prior to applying mcdm methods. subsequently, the remaining areas are not completely unsuitable, yet not the most appropriate locations for a landfill. afterwards, potential sites are obtained from more suitable locations. considering too many criteria in the first stage could decrease the efficiency of the analytic hierarchy process (ahp) method; therefore, to deploy a more pragmatic approach, a limited number of criteria are considered for initial selection of candidate sites. in the second stage, potential sites are evaluated and ranked through a more thorough investigation utilizing the analytic network process (anp) method. additionally, buffers for unsuitable zones of less emphasized importance are eliminated too, and more criteria are taken into account.