Assessing the impacts of flooding on vegetation cover in the Shashe-Limpopo confluence area using earth observation data
Date
2018
Authors
Gangashe, Andani Theophenia
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Abstract
The extensive and frequent flood events in the Shashe-Limpopo confluence area provide an
opportunity to investigate the impacts of such an extreme event in terms of vegetation cover.
Extreme flooding events are expected to occur more frequently as a consequence of climate
change. Understanding the impacts of flood events on vegetation dynamic would be very
useful to develop a dynamic simulation model that can predict the woody species
composition of water retention areas or restored floodplains on the basis of flooding
characteristics and therefore proposed riverine forest and landscape planning and
management.
This study used Landsat 7 data to quantify the response of vegetation to flood events in the
Shashe-Limpopo confluence area. Two flood events that occurred in 2000 and 2013
respectively were analysed to evaluate the patterns of vegetation response in the area of
study. Different indices such as NDVI, NDWI and Modified NDWI (MNDWI) were tested in
mapping vegetation patterns and the flood extent. The MNDWI was shown to be more
effective in extracting water information than the NDWI. NDVI results and change detection
statistical change showed efficiency in indicating vegetation response to floods. The results
show that using MNDWI and a 0.2 threshold value, water delineation is possible. Vegetation
shows that it flourishes after the floods however; there is some degree of change. The results
derived from this can be able to help with landscape planning and management.
Description
A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science (Geography and Environmental Studies) at the School of Geography, Archaeology & Environmental Studies. Johannesburg, 24 February 2018.
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Citation
Gangashe, Andani Theophenia (2018) Assessing the impacts of flooding on vegetation damage and mortality of riparian tree species in the Shashe-Limpopo confluence area using landsat earth observation data, University of the Witwatersrand, Johannesburg, https://hdl.handle.net/10539/25636