THE USE OF GEOGRAPHIC INFORMATION SYSTEM IN LANDFILL SITES SELECTION
This study identifies suitable sites appropriate for solid waste landfill in the vicinity of Jos-North using Remote Sensing and of Geographic Information Systems (GIS). Remote Sensing was used for generating a land use map of the study area and GIS was used in integrating various layers of information, practically having the same spatial reference, to produce a suitability map for solid waste landfill. The task required a number of multiple criteria, and each having some level of importance. In order to accommodate the significant role of each criteria, the Multicriteria Decision Analysis (MCDA), particularly Analytic Hierarchy Process (AHP) was employed. For this purpose, nine (9) input map layers including settlements, roads, wetlands, slope, geology, soil, landuse, floodplains, and surface water were prepared and used as constraint criteria for determining suitability. Weighted overlay tool in ArcGIS 9.3 was used for the final suitability map, and it yielded conformable results. Out of 291km2 of the entire study area, 20.8km2 was found to be suitable for siting sustainable landfill. The map layers related with geology, hydro geology, and land use are based on available data. Because they are not specifically prepared for landfill site selection purpose, the information provided from these maps were not quite satisfactory. It is understood that rather than general purpose lithological map, the maps showing distribution, thickness, and characteristics of the unconsolidated superficial deposits are more helpful. Thus, for landfill siting studies, special purpose engineering geological and hydrogeological maps are required. The slope layer needs to be refined to exclude those areas along the ridges and the hill tops.
1.1 BACKGROUND TO THE STUDY
Solid waste management is an important element in public health and environmental protection (Yesilnacar & Cetin, 2005). Its main purpose is to provide hygienic, efficient and economic collection, transportation, treatment and/or disposal of solid wastes without polluting the atmosphere, soil or water resources, and the management strategy should address the issue of aesthetic (UNDP, 1997 ) .