Using Outranking Methods for Optimum Setting of Air Pollution Monitoring Stations

In recent years, increasing population, vehicles and industrial growth have caused air pollution that is initiated many environmental problems and damaged public health. In Tehran metropolis, increasing machine life and human activities on one hand and extreme topographic conditions and natural factors on the other hand has led the city to be the most polluted city of the world. Due to the necessity of preventing and reducing risks of air pollution, acquiring good knowledge of various aspects of this issue is very important.To check the air quality in different regions, pollution data collected in air pollution stations are required. Air pollution data are needed for studies and decisions about reducing and controlling it. According to the construction of new stations, the precise locating of them is very important. For better and more realistic monitoring of air pollution, the stations must be distributed exactly and evenly. Thus, one of the important considerations in implementing an air pollution control system is selecting the suitable locations for stations.To determine the appropriate places for the construction of new stations, appropriate measures and models are specified. WSM (Weighted Sum Method), ELECTRE (Elimination and Choice Translating Reality) and PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluations) are three popular models of decision making methods. In this paper, these 3 methods are used to optimally locate air pollution stations. For this purpose, 20 new locations were initially proposed in Tehran. Thereafter, governing factors layer, such as population density, distance to nearby stations, distance to trees, building walls and streets, are prepared. Priorities of stations are estimated based on the three methods. Thus, to provide a unique ranking for the methods, the triple consolidating methods (simple average, Borda and Copland) were exercised. Finally, to compare the validity of results, air quality maps were generated.