The use of Landsat and aerial photography for the assessment of coastal erosion and erosion susceptibility in False Bay, South Africa
Date
2015-06
Journal Title
Journal ISSN
Volume Title
Publisher
CONSAS Conference
Abstract
Coastal erosion is a worldwide hazard, the consequences of which can only be mitigated via
thorough and efficient monitoring of erosion. This study aimed to employ remote sensing techniques
on aerial photographs and Landsat TM/ETM+ imagery for the detection and monitoring of coastal
erosion in False Bay, South Africa. Vegetation change detection as well as post-classification
change detection were performed on the Landsat imagery. Furthermore, aerial photographs were
analysed using the Digital Shoreline Analysis System (DSAS), which determines statistical
differences in shoreline position over time. The results showed that while the resolution of the
Landsat imagery was not sufficient to quantify and analyse erosion along the beach itself, the
larger area covered by the satellite images enabled the identification of changes in landcover
conditions leading to an increased susceptibility to erosion. Notably, the post-classification
change detection indicated consistent increases in built-up areas, while sand dune, beach, and sand
(not beach) decreased. NDVI differencing led to the conclusion that vegetation health was
decreasing while reflective surfaces such as bare sand and roads were increasing. Both of these are
indicative of an increased susceptibility to coastal erosion. Aerial photographs were used for
detailed analysis of four focus areas and results indicated that coastal erosion was taking place
at all four areas. The higher resolution available on the aerial photographs was vital for the
quantification of erosion
and sedimentation rates.
Description
CITATION: Callaghan, K., Engelbrecht, J. & Kemp, J. 2015. The use of Landsat and aerial photography for the assessment of coastal erosion and erosion susceptibility in False Bay, South Africa. South African Journal of Geomatics, 4(2):65-79.
The original publication is available at http://www.sajg.org.za
The original publication is available at http://www.sajg.org.za
Keywords
Landsat satellites, Erosion, Aerial photography
Citation
Callaghan, K., Engelbrecht, J. & Kemp, J. 2015. The use of Landsat and aerial photography for the assessment of coastal erosion and erosion susceptibility in False Bay, South Africa. South African Journal of Geomatics, 4(2):65-79.