Morphostructural characterization of the western edge of the Huila Plateau (SW Angola), based on remote sensing techniques

Recognition of the main morphostructural features of the western edge of the Huila Plateau (SW Angola) can be done by using remote sensing techniques associated with field work. A digital elevation model (DEM) of the area was built for this purpose. This model is based on altimeter data acquired from the Aster sensor, on which image processing techniques such as enhancement techniques, contrast change and filtering were applied. Other techniques, such as RGB colour composition, were also tested. The processed satellite images were interpreted by visual process and the results were then compared with available geological maps (scale 1: 1 000 000). To facilitate both analysis and interpretation, the edge of the plateau was divided into three sectors: northern (or Chongoroi Edge), central (or Humpata Edge) and southern (or Oncocua Edge). For each sector, the main morphological aspects and main lineament systems were identified and characterized. In the specific case of the central sector, these parameters were also confirmed by field work. This study shows that the morphology of the western edge of the plateau is dominated by N50 degrees W-N60 degrees W, N60 degrees E and N-S trending main tectonic systems. These results have important implications in terms of geological mapping and regional tectonics as well as in land-use planning and other areas, such as hydrogeology or geotechnics. (C) 2016 Elsevier Ltd. All rights reserved.