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Land Use Change in The Knysna River Catchment and Its Impacts on the Geomorphological Characteristics of the Estuary between 1984 and 2019

The Knysna catchment and estuary are recognized in South Africa for their conservation significance as a sanctuary for marine species and biodiversity alike. The economy of the area which is dependent on tourism of the Knysna Estuary and catchment. The services obtained from the ecosystem include in...

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Main Author: Taylor, Salwah
Other Authors: Meadows, Michael Edward
Format: Thesis
Language:English
Published: Department of Environmental and Geographical Science 2023
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access_status_str Open Access
author Taylor, Salwah
author2 Meadows, Michael Edward
author_browse Meadows, Michael Edward
Taylor, Salwah
author_facet Meadows, Michael Edward
Taylor, Salwah
author_sort Taylor, Salwah
collection Thesis
description The Knysna catchment and estuary are recognized in South Africa for their conservation significance as a sanctuary for marine species and biodiversity alike. The economy of the area which is dependent on tourism of the Knysna Estuary and catchment. The services obtained from the ecosystem include integral biodiversity value and is of significant importance for residents and tourists. Land use and land use cover dynamics remain some of the most crucial and obvious changes that has happened in the Knysna Estuary and catchment. Such changes severely affect ecosystems health, catchment areas, estuaries and the degradation of nature reserves. A ‘cloud-based platform for scientific analysis and visualization of geospatial datasets.' (Liu et al., 2020) method namely Google Earth Engine (GEE) is applied utilizing multi-temporal satellite imagery and Sentinel as interpretation to understand land use change over 35 years. A timeseries associated with land use changes and biodiversity loss were considered between the years 1984 and 2019. Additionally, Normalized Difference Vegetation Index (NDVI) and Supervised classification were performed using GEE software and Arc Geographical information systems (GIS) to identify land cover dynamics. The images are classified into three major land use classes, waterbodies, urban areas and vegetation. Vegetation is further classified into various classes namely fynbos, thicket, plantation forestry, salt marsh and agriculture. An accuracy assessment together with ground truthing, were conducted to verify and assess the overall classification accuracy of the results. The results indicated that over the study period urban growth and cultivated land makes up the most common land use category to have impacted the Knysna Estuary. Urban areas have increased significantly in reaction to the rapid increase in population ranging from 2.5% - 2.8% during the years 1984-1992, which reached to 2.9% - 4.1% during the years 1993-2007, and finally augmented to 4.3% to 6.3% during the years 2008-2019. The major reason behind the altering in the land use and geomorphology based on the research of the Knysna Estuary is human activities that have led to key determinantal impacts on surface runoff and land degradation. Overall, the noticeable changes in surface runoff and land degradation are strongly related to land use/land cover changes brought about by human impacts.
format Thesis
id oai:open.uct.ac.za:11427/37372
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:52:59.775Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2023
publishDateRange 2023
publishDateSort 2023
publisher Department of Environmental and Geographical Science
publisherStr Department of Environmental and Geographical Science
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/37372 Land Use Change in The Knysna River Catchment and Its Impacts on the Geomorphological Characteristics of the Estuary between 1984 and 2019 Taylor, Salwah Meadows, Michael Edward Land use/cover change Arc GIS Google Earth Engine satellite image Sentinel NDVI supervised classification accuracy assessment The Knysna catchment and estuary are recognized in South Africa for their conservation significance as a sanctuary for marine species and biodiversity alike. The economy of the area which is dependent on tourism of the Knysna Estuary and catchment. The services obtained from the ecosystem include integral biodiversity value and is of significant importance for residents and tourists. Land use and land use cover dynamics remain some of the most crucial and obvious changes that has happened in the Knysna Estuary and catchment. Such changes severely affect ecosystems health, catchment areas, estuaries and the degradation of nature reserves. A ‘cloud-based platform for scientific analysis and visualization of geospatial datasets.' (Liu et al., 2020) method namely Google Earth Engine (GEE) is applied utilizing multi-temporal satellite imagery and Sentinel as interpretation to understand land use change over 35 years. A timeseries associated with land use changes and biodiversity loss were considered between the years 1984 and 2019. Additionally, Normalized Difference Vegetation Index (NDVI) and Supervised classification were performed using GEE software and Arc Geographical information systems (GIS) to identify land cover dynamics. The images are classified into three major land use classes, waterbodies, urban areas and vegetation. Vegetation is further classified into various classes namely fynbos, thicket, plantation forestry, salt marsh and agriculture. An accuracy assessment together with ground truthing, were conducted to verify and assess the overall classification accuracy of the results. The results indicated that over the study period urban growth and cultivated land makes up the most common land use category to have impacted the Knysna Estuary. Urban areas have increased significantly in reaction to the rapid increase in population ranging from 2.5% - 2.8% during the years 1984-1992, which reached to 2.9% - 4.1% during the years 1993-2007, and finally augmented to 4.3% to 6.3% during the years 2008-2019. The major reason behind the altering in the land use and geomorphology based on the research of the Knysna Estuary is human activities that have led to key determinantal impacts on surface runoff and land degradation. Overall, the noticeable changes in surface runoff and land degradation are strongly related to land use/land cover changes brought about by human impacts. 2023-03-13T09:56:40Z 2023-03-13T09:56:40Z 2022 2023-02-21T07:22:50Z Master Thesis Masters MPhil http://hdl.handle.net/11427/37372 eng application/pdf Department of Environmental and Geographical Science Faculty of Science
spellingShingle Land use/cover change
Arc GIS
Google Earth Engine
satellite image
Sentinel
NDVI
supervised classification
accuracy assessment
Taylor, Salwah
Land Use Change in The Knysna River Catchment and Its Impacts on the Geomorphological Characteristics of the Estuary between 1984 and 2019
thesis_degree_str Master's
title Land Use Change in The Knysna River Catchment and Its Impacts on the Geomorphological Characteristics of the Estuary between 1984 and 2019
title_full Land Use Change in The Knysna River Catchment and Its Impacts on the Geomorphological Characteristics of the Estuary between 1984 and 2019
title_fullStr Land Use Change in The Knysna River Catchment and Its Impacts on the Geomorphological Characteristics of the Estuary between 1984 and 2019
title_full_unstemmed Land Use Change in The Knysna River Catchment and Its Impacts on the Geomorphological Characteristics of the Estuary between 1984 and 2019
title_short Land Use Change in The Knysna River Catchment and Its Impacts on the Geomorphological Characteristics of the Estuary between 1984 and 2019
title_sort land use change in the knysna river catchment and its impacts on the geomorphological characteristics of the estuary between 1984 and 2019
topic Land use/cover change
Arc GIS
Google Earth Engine
satellite image
Sentinel
NDVI
supervised classification
accuracy assessment
url http://hdl.handle.net/11427/37372
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