Abstract:
Detailed geomorphological mapping is important for monitoring environmental
phenomena, it is therefore crucial that the methods employed for mapping are
accurate. The basis of remote sensing for geomorphological work is moving from
the consideration of whether satellite data are accurate for landform mapping to
how surfaces of interest can be defined from remote sensing data, since earlier
approaches of mapping are deemed costly and tedious. The aim of this study is to
assess the suitability of ASTER and SRTM DEMs, and satellite imagery in detailed
geomorphological mapping. Field survey and aerial photo interpretation were used
to prepare a reference geomorphological map for comparisons. A similar approach
of demarcating landform boundaries from aerial photographs was implemented to
segment the DEMs into landform classes. The software packages that were used
for processing the satellite data to create detailed geomorphological maps are
QGIS with GRASS and SAGA plugins, and ENVI. The resultant geomorphological
units’ maps from the DEMs when compared with the reference geomorphological
map, show that the automated classification technique has advantages in terms of
its efficiency and reproducibility. Nevertheless, distinct limitations of the technique
are apparent and the technique is not suitable for detailed geomorphological
mapping in the proposed study area.
