Main Article Content
Constraint map for landfill site selection in Akure Metropolis, Southwestern Nigeria
Abstract
An integration of remote sensing, soil type, geological, geoelectrical, hydrogeological and geotechnical data was carried out in a GIS environment with a view to developing a constraint map for the location of landfill (waste disposal) site(s) in Akure, Metropolis.. Geomorphological features identified from satellite images include o residual hills, pediments, pediplain and etchplain . The slope (gradient) map displays surface gradients of 0 - 2.5 o along river channels while areas with moderate and high relief have surface gradients of 2.5 - 6.35 and 6.35 - o 29.53o respectively. Satellite-imagery-delineated lineaments predominantly trend NNW-SSE, ENE-WSW and NNE-SSW with subsidiary NW-SE and W-E trends that are typical of the Basement Complex region of Nigeria. The engineering geotechnical results show that charnockite-derived soils are very clayey and silty in nature (with % clay content > 18%) with low permeability, and are therefore more suitable for waste disposal (landfill) site than the sandy and gravely (with low % clay content < 7%) granite and migmatite gneiss-derived soils. VESderived topsoil and weathered layer are characterized by relatively low layer resistivity values (< 100 ohm-m) over basic charnockitic rocks. The synthesis of the above results enables the classification of the Akure metropolis into three landfill suitability zones – unsuitable (28.6%); moderately suitable (40.4%), and suitable (13%) for waste disposal (landfill) sitting.
Keywords: GIS, Remote Sensing, Geoelectric, Geotechnical, Constrain Map, Landfill Site.