Combine electrical resistivity method and multi-criteria GIS-based modeling for landfill site selection in the Southwestern Nigeria

An integration of remote sensing and geophysical data was carried out in Odode-Idanre using Geographic Information System (GIS) approach with the aim of developing a landfill site selection map of the area. The area falls within the Precambrian Basement complex of southwestern Nigeria. The remote sensing involved the processing and interpretation of Landsat-7 EMT + image covering the study area and the data were used to produce the lineament, slope, drainage and land use maps of the area. The geophysical investigation involved the vertical electrical sounding (VES) technique using Schlumberger configuration with half electrode spacing (AB/2) varying from 1 to 65 m, One hundred and one (101) soundings stations were occupied within the study area. The interpretation of the VES data was used to generate the geoelectric section and determine Dar Zarrouk parameters. The results were used to generate thematic overburden and the coefficient of anisotropy maps. The geoelectric sections generally identified four geologic/geoelectric sequences that comprise topsoil, weathered layer, fractured Basement and fresh Basement. The depth to the Basement is generally less than 10 m. The multi-criteria evaluation (MCE) analysis were used to assign weights to slope, land use, drainage density, lineament density, coefficient of anisotropy and overburden thickness using the analytical hierarchy process (AHP) and this was used to produce the landfill suitability map. The area was classified into unsuitable, moderately suitable and suitable zones. The unsuitable areas cover about 21.9%, moderately suitable areas cover about 55% and the suitable areas cover about 23.1%. The suitable areas are scattered and discontinuous but predominant within the southern part of the area. For the development of waste dump site within the study area, it should be located within the southern part which was found to be suitable.