Application of Electre model in locating of municipal solid waste landfill (case study: the city of Khorramabad)

Nowadays, increasing the urban population, followed increasing in waste production has attracted the attention of environmental researchers towards the sanitary waste disposal. It is estimated that in Khorramabad city with a population of over than 348,216 people, about 458 tones of urban waste are daily produced which are dumped in open lands. Therefore, finding a suitable site for waste disposal is necessary. The purpose of this study is to identify and introduce suitable locations for the sanitary waste disposal across the city using Electre as a Multi Criteria Decision Analysis.
Material and For this purpose, 14 criteria including soil erosion, geology, land use, distance to roads, distance to rivers, springs and kanats, distance to faults, distance to cities and villages, slope, elevation, groundwater depth, distance to protected areas and climate were used. Three common methods including Boolean, Analytic Hierarchy Process (AHP) and Linear Combination Weighted (WLC) were used to combine the criteria maps. Considering the minimum area required for landfill sitting for a period of 20 years, five candidate sites were ultimately extracted from the final resulting map of WLC in order to introduce the best site for urban landfill. Then, these five candidates were ranked using Electre model.
Results of weighting process showed that the groundwater depth, distance to faults and cities had the highest weights whereas elevation and slope criteria had the lowest weights. The consistency ratio for the weighting process was 0.08, which was less than 0.1, presenting the consistency and credibility of the weighting process. According to the WLC method, major parts of north-west, west and north of the area under study were identified as optimal sites. According to the results of Electre model, a site with an area of 694 hectares located in the west of city was identified as the best alternative.
The results showed that the Electre method along with multi-criteria evaluation methods can have high performance in locating sanitary municipal solid waste disposal.