A Semi Automated Technique to Regolith-Landform mapping in West Africa

Abstract

Large regional airborne surveys have been flown over much of Nigeria, Niger and Ghana the data collected (mag spec and gamma radiometrics) in conjunction with Landsat ETM7+ and Shuttle Radar Topography Mission (SRTM) data sets are being used to create Regolith- Landform maps. Desktop GIS based techniques are being employed to automate the process as much as possible. Minimal field calibration of the mapping products is possible due to contract and time constraints. The RT-map system (Pain et al 2000) developed at Geoscience Australia for Australian Regolith has been adapted for the purposes of this work. Mapping was completed at scales ranging from 1:50,000 to 1:250,000. Automated mapping techniques will become increasingly viable as high resolution datasets become more available and computing and GIS improve. The technique has been successfully used to map large portions of Niger and Nigeria for the respective government surveys.