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Trends in soil erosion and land use in the Upper Tugela catchment

Each year, approximately 75 billion tons of soil are eroded from the Earth’s
terrestrial ecosystems and the majority of agricultural land in the world is losing soil at
rates of between 13 tons/ha/year and 40 tons/ha/year. South Africa is prone to soil erosion,
because of poor farming methods, together with soils which are erodible. In order to
understand more about the nature of soil erosion in South Africa, the geology and lithology
needs to be well understood too. This study adds to the understanding of the relationship
between soil erosion and land use. In South Africa soil erosion research has been
undertaken, however, each and every region requires its own research on a different scale
and using different technique to fit the unique characteristics of the area.
This research begins by investigating the studies which have been undertaken
concerning soil erosion and land use, and how these processes are defined and expressed
in different contexts. An historical analysis of the former Homeland areas, recreational
resorts and Royal Natal National Park in the upper Tugela catchment was conducted over
a 50-year period (1964 to 2014). Field trips were conducted in six study sites, in the
Bergville district, Drakensberg, to carry out ground-truthing, obtain onsite imagery and
validate/verify findings from the research. Desktop research entailed the use of ArcGIS,
Google Earth, statistics and an analysis of aerial images which date from 1964 to 2014. The results show a greater number of erosion features and more extensive erosion
in the former Homeland areas, which form part of the rural area of the study site, compared
to the Park (Royal Natal National Park) and recreational resorts. Erosion in the study sites
was defined according to the SARCCUS framework, and this involves the development
from primarily sheet erosion in 1964, to intricate gully patterns and river bank erosion in
2014. The study also shows that there is a relationship between population and the
vegetated area: as the number of households increased from 1964 to 2014, the grass
cover, trees and grazing land in the area declined.
Overgrazing plays a role in determining the extent of the erosion. However, it is the
relationship between increasing population numbers and the nature of livestock keeping
among village dwellers which influenced overgrazing levels, and subsequently the extent of
erosion. Mitigating soil erosion impacts is an issue which has to be addressed not only on
the local scale, but national government also needs to make it a point that the general
landscape of the country is well managed with regards to soil erosion.
The outcomes from this study support the notion that soil erosion processes are
very complex and that delineation of soil erosion features entails a certain level of
subjectivity. Human influences and land use dynamics also influence the rates of soil
erosion and this study shows how different land uses, but similar environmental factors,
can lead to different rates and intensities of soil erosion. In conjunction with GIS and
remote sensing, satellite imagery and aerial photos play an important role in the analysis
and understanding of the study area and the different geological, biological and
anthropological features present. The presence and the availability of high quality imagery
helps then in ensuring that resolute and reliable information is established. / Dissertation (MSc)--University of Pretoria, 2018. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:up/oai:repository.up.ac.za:2263/67755
Date January 2018
CreatorsKuse, Mzukisi
ContributorsSumner, P.D. (Paul), mzukuse@gmail.com, Loubser, M.J. (Michael John)
PublisherUniversity of Pretoria
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageEnglish
TypeDissertation
Rights© 2018 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.

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