Landfill Site Selection for Municipal Waste Materials Using Inversion Hierarchical Weighing Process (IHWP)

Sanandaj city, with a population of 370,000 people, faces daily generation of 330 tons of solid wastes. Current landfill site of the city has caused environmental problems while losing its capacity. This study attempts to determine the land suitability to dispose municipal solid wastes in Sanandaj. Landfill site selection is a multi-criteria decision making analysis that uses GIS and multi-criteria decision-making methods.
In this research, we used the Inversion Hierarchical Weight Process (IHWP) and GIS software to locate the best landfill location. For this purpose, 12 ecological and socio-economical information layers were weighted according to IHWP method. The map of land suitability for a landfill construction was obtained by using overlay functions and 9 exclusionary criteria which were used to prepare the restriction map.
Findings: Classification of the final map indicated that 91.5 percent of the study area was completely unsuitable for landfill site selection purpose while areas with the highest suitability contained only 0.16 percent of the city. Finally an area with the extent of 44 hectares, located approximately 4 km north-west of the Sanandaj was identified as priority number one to establish landfill.
The results of this study show that IHWP method can be used as a new method for combining natural and artificial data layers in projects with site selection targets, including landfill site selection, and if it accompanied by field surveys, can provide the best decision-making options regarding to the goal.