aplication of topsis model in site selection of paper recycling centers using gis; case study: fars province

introductiontoday, one of the most prominent health and environmental problems of cities is ascending trend of solidwastes. this must be managed and the institutionalization of phenomena such as recycling, composting, and soon from municipal solid waste must be taken into consideration. in iran, there is no essential management incollection, disposal and recycling of over 40 thousand tons of the waste per day which approximately 70 percentof them can be recycled into compost with thousands of plastics, papers and cartons. thus, the waste are buriedin the excess trend or scattered around cities. usually based on the weight and physical composition of municipalsolid wastes, we can say that most components of municipal solid wastes after organic solid wastes and animportant part of municipal and industrial solid wastes in most parts of the world are paper wastes. whileamount of recyclable paper waste generated in iran is considerable, but only a small part of that is recycled andthe remaining is exerted as garbage. while, it is possible to recycle the most part of the paper waste for theproduction of paper with high quality. in the recent decades, with growing public awareness of the dangers ofuncontrolled harvesting of hardwood resources, increasing prices of raw materials for paper production,decreasing the forest area in some major areas of wood production and resistance of organizations andenvironmentalists against the dameges, there are increasing demands towards the recycling of consumed paper inorder to meet the needs for paper.there are various capacities in the converting machines for the paper recovery that provide the possibility fordeveloping paper recovery centers in the regains with medium or large areas. with these qualities, investing inthe creation of paper recovery units and consequently selecting appropriate locations for the deployment of theseunits is a critical step for municipal waste management system. therefore, it is necessary to institutionalize usingof decision support systems, in process of site selection for paper recovery units.the process to determine the suitability of land for locating paper recovery centers requires consideration ofmultiple criteria. that makes it necessary to use multi-criteria analysis models and techniques as inevitablechoice. thus, using multi-criteria models and techniques that are applied in conjunction with gis capabilitiescan be considered as the outstanding aspects of decision support systems (dss) in the decision process. usingdecision rules, we can classify alternatives according to priority in the process of site selection. accordingly, inthis paper, there are intentions to test the operational capabilities of topsis model as one of the leadingtechniques in multi-criteria decision making. this is applied in the experimental field of site selection for paperrecovery centers in fars province.methodologythe data and tools used in this paper are maps and information that have been collected based on the need for thecriteria and the constraints that are applied to determine the desirability of lands in locating paper recoverycenters in fars province. in this study, softwares have been used to fit the needs in the phases of data entry, datastorage, data management, data processing, data analysis, and etc. these softwares are including excel 2007, arcgis 9.3, arc view 3.3, kilimanjaro idrisi, and ilwis 3.3. the main steps in the process of this study relatedto the research methodology are:1. providing criterion and constraint maps that are used in locating landfills which have led to defining of 10criteria and 8 constraints. 2. valuation and standardization of criterion maps: the process of valuation and standardization was performedbased on value of membership in fuzzy set. standardization was performed using the possibilities that existin the fuzzy function of idrisi kilimanjaro software.3. the method for weighting criterion maps: in this step, we have tried to determine criterion weights andcriterion significance coefficient by using critic method.4. operational use of multi-criteria decision rules: in this step, there is intention to test the operationalcapabilities of topsis model as a prominent example of the multi-criteria analysis techniques in theexperimental field of the site selection for paper recovery centers in fars provincediscussionin this research, classified maps represent suitability of locations for paper recovery centers.the values areassigned by the accomplishment of operational procedures and guidelines that is obtained the process of usingtopsis method (fig. 1). in the obtained map as the scoreof each pixel approaches to 1, this is indicatingfavorable conditions for that pixel to be selected as a paper recovery center. taking to consideration theconstraints (fig. 2), these pixels can be used proportionally to show the ability of that area for another landuse.therefore, obtained maps can be used as guidance by the decision makers in selecting appropriate locations forpaper recovery centers. for further documentation of the validity of land use suitability map that has been acquired in the process ofusing topsis, we have tried to investigate on the characteristic of one sample pixel that is selected as preferableand is located on the area with no constraints, dealt with defined criteria.conclusionin this paper by considering fars province as a case study, capabilities and operational mechanisms of topsismodel has been tested in site selection of paper recovery centers. in this step, there was the goal to test theoperational capabilities of topsis model as a prominent example of the multi-criteria analysis techniques in theexperimental field of the site selection for paper recovery centers in fars province. for further documentation ofthe validity of land use suitability map acquired in the process topsis application, we have tried to investigatefurther on the conditions of one sample pixel that is selected as suitable pixel on the area with no constraints.results of the investigation indicatethat the pixels that are selected as preferable pixels in the output map havethe optimal conditions in terms of defined criteria. for example, this pixel that has been selected as a preferablepixel is labeled with scores more than 230 in 9 criteria and is located in the acceptable condition in terms ofdegree of membership in fuzzy function. therefore, this model can be used as a decision support system (dss)in the modeling spatial arrangement of paper recovery centers.