Geomorphic and ambient environmental impacts on lichen distribution on two inland Nunataks in western Dronning Maud Land, Antarctica
- Authors: Dwight, Rosemary Anne
- Date: 2015
- Subjects: Lichens -- Antarctica -- Queen Maud Land , Lichen communities -- Antarctica -- Queen Maud Land , Lichens -- Climatic factors -- Antarctica -- Queen Maud Land , Lichens -- Effect of environment on -- Antarctica -- Queen Maud Land , Biotic communities -- Antarctica -- Queen Maud Land , Biotic communities -- Climatic factors -- Antarctica -- Queen Maud Land , Biodiversity -- Climatic factors -- Antarctica -- Queen Maud Land
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4889 , http://hdl.handle.net/10962/d1018189
- Description: Feedbacks between abiotic variables and community structure in Antarctica are poorly understood. Research is, therefore, required to elucidate the patterns of biodiversity that exist and the factors that influence them, particularly under changing climates. Landscape processes affect environmental heterogeneity, which in turn affect patterns of biodiversity. Two inland Antarctic nunataks, Robertskollen and the Northern Buttress of Vesleskarvet, were selected for investigation to determine the potential impact of selected environmental factors on lichen distribution and abundance, at the intra- and inter-nunatak scales. Lichens were found to prefer rock faces with dips between 1° and 45°, and northern/southern aspects. Lichen colonisation was mostly in microtopographical features that result from rock weathering. The distribution of lichens was found to be regular at the intra- and inter-nunatak scale, whereas lichen abundance was found to be mostly influenced by temperature. On the Northern Buttress, rock hardness displays a similar pattern to lichen abundance, both of which are suggested to be a function of exposure time, which is dependent on deglaciation. The two nunataks serve as excellent laboratories that can potentially be used as proxies for investigating the possible impacts of climate change
- Full Text:
- Date Issued: 2015
- Authors: Dwight, Rosemary Anne
- Date: 2015
- Subjects: Lichens -- Antarctica -- Queen Maud Land , Lichen communities -- Antarctica -- Queen Maud Land , Lichens -- Climatic factors -- Antarctica -- Queen Maud Land , Lichens -- Effect of environment on -- Antarctica -- Queen Maud Land , Biotic communities -- Antarctica -- Queen Maud Land , Biotic communities -- Climatic factors -- Antarctica -- Queen Maud Land , Biodiversity -- Climatic factors -- Antarctica -- Queen Maud Land
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4889 , http://hdl.handle.net/10962/d1018189
- Description: Feedbacks between abiotic variables and community structure in Antarctica are poorly understood. Research is, therefore, required to elucidate the patterns of biodiversity that exist and the factors that influence them, particularly under changing climates. Landscape processes affect environmental heterogeneity, which in turn affect patterns of biodiversity. Two inland Antarctic nunataks, Robertskollen and the Northern Buttress of Vesleskarvet, were selected for investigation to determine the potential impact of selected environmental factors on lichen distribution and abundance, at the intra- and inter-nunatak scales. Lichens were found to prefer rock faces with dips between 1° and 45°, and northern/southern aspects. Lichen colonisation was mostly in microtopographical features that result from rock weathering. The distribution of lichens was found to be regular at the intra- and inter-nunatak scale, whereas lichen abundance was found to be mostly influenced by temperature. On the Northern Buttress, rock hardness displays a similar pattern to lichen abundance, both of which are suggested to be a function of exposure time, which is dependent on deglaciation. The two nunataks serve as excellent laboratories that can potentially be used as proxies for investigating the possible impacts of climate change
- Full Text:
- Date Issued: 2015
On active layer processes and landforms in western Dronning Maud Land, Antarctica
- Authors: Scott, David Alan
- Date: 2015
- Subjects: Landforms -- Antarctica -- Queen Maud Land , Permafrost -- Antarctica -- Queen Maud Land , Permafrost -- Thermal properties -- Antarctica -- Queen Maud Land , Climatic changes -- Antarctica -- Queen Maud Land , Cryosphere , Drone aircraft -- Antarctica -- Queen Maud Land , 3-D modeling
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4893 , http://hdl.handle.net/10962/d1019757
- Description: Permafrost is a variable in Antarctic terrestrial ecosystems, and the role it plays in the cryosphere is not well understood. There is much still to be learnt about the thermal state, physical properties, thickness and age of permafrost in Western Dronning Maud Land (WDML). Active layer dynamics and observed change over time have the potential to improve our knowledge of climate change. Understanding the effects of a warming climate on permafrost can also be of benefit to infrastructure, especially in areas with a large amount of frozen ground such as Scandinavia, Canada and Russia. Active layer and permafrost dynamics of WDML, Antarctica, are presented and discussed using data from six study sites, namely the Robertskollen, Vesleskarvet, Flarjuven, Grunehogna, Slettjfell nunataks and the Troll research station in the Jutulsessen area. Ground and ambient air temperature, as well as ground moisture data were collected for each site. An inventory of active layer and permafrost landforms was compiled, as were the frequency of cycles over the zero-degree isotherm, and the depth of the active layer. Furthermore, 3D models, geo-referenced maps and Digital Elevation Models were created of study areas with the use of an Unmanned Aerial Vehicle (UAV). Polygonal features are the most common landscape feature and are common to most of the study sites. Robertskollen has the deepest active layer at over 66cm and Slettfjell the shallowest at 9cm. A maximum recorded air temperature of 8.76°C (10/11/2014) occurred at Troll with the second highest maximum of 6.77°C (22/12/2010) recorded at Vesleskarvet. Robertskollen has the highest observable biological growth and a maximum recorded ground temperature of 22.84°C (10/01/2014). Troll and Valterkulten, registered the second and third highest ground temperatures respectively. The high ground Temperature observed for Robertskollen may be ascribed to it being the lowest altitude site. The highest number of cycles over the zero-degree isotherm was observed at Troll (11.01%), followed by Robertskollen (10.99%). For relatively warm areas, such as Robertskollen it is recommended that two metre borehole loggers are installed in order to capture a detailed understanding of the active layer. The UAV proved to be a beneficial tool for capturing aerial photographs for post fieldwork analysis and 3D modelling.
- Full Text:
- Date Issued: 2015
- Authors: Scott, David Alan
- Date: 2015
- Subjects: Landforms -- Antarctica -- Queen Maud Land , Permafrost -- Antarctica -- Queen Maud Land , Permafrost -- Thermal properties -- Antarctica -- Queen Maud Land , Climatic changes -- Antarctica -- Queen Maud Land , Cryosphere , Drone aircraft -- Antarctica -- Queen Maud Land , 3-D modeling
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4893 , http://hdl.handle.net/10962/d1019757
- Description: Permafrost is a variable in Antarctic terrestrial ecosystems, and the role it plays in the cryosphere is not well understood. There is much still to be learnt about the thermal state, physical properties, thickness and age of permafrost in Western Dronning Maud Land (WDML). Active layer dynamics and observed change over time have the potential to improve our knowledge of climate change. Understanding the effects of a warming climate on permafrost can also be of benefit to infrastructure, especially in areas with a large amount of frozen ground such as Scandinavia, Canada and Russia. Active layer and permafrost dynamics of WDML, Antarctica, are presented and discussed using data from six study sites, namely the Robertskollen, Vesleskarvet, Flarjuven, Grunehogna, Slettjfell nunataks and the Troll research station in the Jutulsessen area. Ground and ambient air temperature, as well as ground moisture data were collected for each site. An inventory of active layer and permafrost landforms was compiled, as were the frequency of cycles over the zero-degree isotherm, and the depth of the active layer. Furthermore, 3D models, geo-referenced maps and Digital Elevation Models were created of study areas with the use of an Unmanned Aerial Vehicle (UAV). Polygonal features are the most common landscape feature and are common to most of the study sites. Robertskollen has the deepest active layer at over 66cm and Slettfjell the shallowest at 9cm. A maximum recorded air temperature of 8.76°C (10/11/2014) occurred at Troll with the second highest maximum of 6.77°C (22/12/2010) recorded at Vesleskarvet. Robertskollen has the highest observable biological growth and a maximum recorded ground temperature of 22.84°C (10/01/2014). Troll and Valterkulten, registered the second and third highest ground temperatures respectively. The high ground Temperature observed for Robertskollen may be ascribed to it being the lowest altitude site. The highest number of cycles over the zero-degree isotherm was observed at Troll (11.01%), followed by Robertskollen (10.99%). For relatively warm areas, such as Robertskollen it is recommended that two metre borehole loggers are installed in order to capture a detailed understanding of the active layer. The UAV proved to be a beneficial tool for capturing aerial photographs for post fieldwork analysis and 3D modelling.
- Full Text:
- Date Issued: 2015
Mapping and prediction of archaeological sites of habitation by modern humans using GIS and expert mapping on the south coast of South Africa
- Authors: Kleyn, Philippa May
- Date: 2015
- Subjects: Geographic information systems -- South Africa , Archaeological sites , Kitchen-middens -- South Africa , Prehistoric peoples -- South Africa , Prehistoric peoples -- Dwellings -- South Africa , Geological mapping -- South Africa , Coastal archaeology -- South Africa , Archaeological significance -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4890 , http://hdl.handle.net/10962/d1018662
- Description: South Africa contains many archaeological resources including shell middens from the Middle Stone Age (MSA) and Later Stone Age (LSA). These shell middens give researchers insight into the behaviour of modern humans where the first fossil evidence appears in Africa around 200 000 years ago (Klein, 2008). Research into shell middens is therefore vital to understand the origin of human kind. This study investigates whether Geographical Information Systems (GIS) is a useful tool for predicting locations of unknown shell midden sites using the characteristics of known areas of modern human habitation. This was done using suitability analysis and expert mapping techniques. Ground truthing of the results of the desktop analysis revealed that GIS is not a useful tool for predicting sites of modern habitation as the characteristics that determine human habitation are too variable.
- Full Text:
- Date Issued: 2015
- Authors: Kleyn, Philippa May
- Date: 2015
- Subjects: Geographic information systems -- South Africa , Archaeological sites , Kitchen-middens -- South Africa , Prehistoric peoples -- South Africa , Prehistoric peoples -- Dwellings -- South Africa , Geological mapping -- South Africa , Coastal archaeology -- South Africa , Archaeological significance -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4890 , http://hdl.handle.net/10962/d1018662
- Description: South Africa contains many archaeological resources including shell middens from the Middle Stone Age (MSA) and Later Stone Age (LSA). These shell middens give researchers insight into the behaviour of modern humans where the first fossil evidence appears in Africa around 200 000 years ago (Klein, 2008). Research into shell middens is therefore vital to understand the origin of human kind. This study investigates whether Geographical Information Systems (GIS) is a useful tool for predicting locations of unknown shell midden sites using the characteristics of known areas of modern human habitation. This was done using suitability analysis and expert mapping techniques. Ground truthing of the results of the desktop analysis revealed that GIS is not a useful tool for predicting sites of modern habitation as the characteristics that determine human habitation are too variable.
- Full Text:
- Date Issued: 2015
Developing a GIS based method for school site identification in the rural Eastern Cape
- Authors: Swart, Conrad Dirk
- Date: 2015
- Subjects: Geographic information systems -- South Africa -- Eastern Cape , School sites -- South Africa -- Eastern Cape , School sites -- South Africa -- Eastern Cape -- Planning , Rural schools -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4891 , http://hdl.handle.net/10962/d1018939
- Description: Historically, South Africa has not had equal education in terms of funding, curriculum or physical resources and structures. These issues are still present in contemporary South Africa and none more so than the issues surrounding “mud schools”. Recently the Department of Basic Education (DBE) implemented a plan to eradicate inappropriate school structures using the Accelerated Schools Infrastructure Delivery Initiative program (ASIDI). Questions around effective placement of schools are now being asked. Using interviews and analysis of literature, this research developed criteria needed to determine how rural school sites are selected. Geographical Information Systems (GIS) was used to determine if current sites are in the most appropriate areas. The results of the research included a unique set of Eastern Cape criteria as well as an analysis of the current site selection methods used by the DBE. It also revealed that most of the schools are being constructed in acceptable areas. The main result that emerged from the research was that schools will be placed in areas where they are needed. Developing site selection criteria is still needed as South Africa seeks to reduce the education gap between rich and poor schools.
- Full Text:
- Date Issued: 2015
- Authors: Swart, Conrad Dirk
- Date: 2015
- Subjects: Geographic information systems -- South Africa -- Eastern Cape , School sites -- South Africa -- Eastern Cape , School sites -- South Africa -- Eastern Cape -- Planning , Rural schools -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4891 , http://hdl.handle.net/10962/d1018939
- Description: Historically, South Africa has not had equal education in terms of funding, curriculum or physical resources and structures. These issues are still present in contemporary South Africa and none more so than the issues surrounding “mud schools”. Recently the Department of Basic Education (DBE) implemented a plan to eradicate inappropriate school structures using the Accelerated Schools Infrastructure Delivery Initiative program (ASIDI). Questions around effective placement of schools are now being asked. Using interviews and analysis of literature, this research developed criteria needed to determine how rural school sites are selected. Geographical Information Systems (GIS) was used to determine if current sites are in the most appropriate areas. The results of the research included a unique set of Eastern Cape criteria as well as an analysis of the current site selection methods used by the DBE. It also revealed that most of the schools are being constructed in acceptable areas. The main result that emerged from the research was that schools will be placed in areas where they are needed. Developing site selection criteria is still needed as South Africa seeks to reduce the education gap between rich and poor schools.
- Full Text:
- Date Issued: 2015
Coastal landscape change on the Cape St Francis/St Francis Bay peninsula from 1960 to 2014
- Authors: Schroeder, Daniel Heiko
- Date: 2015
- Subjects: Coast changes -- South Africa -- Saint Francis, Cape , Peninsulas -- South Africa -- Saint Francis, Cape , Human ecology -- South Africa -- Saint Francis, Cape , Geographic information systems -- South Africa -- Saint Francis, Cape , Surveying -- South Africa -- Saint Francis, Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5086 , http://hdl.handle.net/10962/d1018203
- Description: A large proportion of the human population, their settlements and socioeconomic activities occur on land directly adjacent to the coastline. The increased demand for coastal leisure and tourism has interfered with natural landscape features and their associated processes. The Cape St Francis/St Francis Bay peninsula located on the southeast coast of South Africa was rapidly developed and transformed from a little fishing village into an urban coastal developed area over a 50-year period (1961-2014). A system that once existed in a state of dynamic or non-equilibrium was interfered with through anthropogenic disturbances, resulting in more frequent and intense natural events, which ranged from floods to debris flows, decreased sand supply and resulting beach erosion. The aim of the project was to identify and map landscape features and changes on the peninsula using an interdisciplinary approach. The triangulated methods of a desktop study using Geographic Information Systems (GIS) and media reviews, a crowdsourcing/participatory approach based on interviews, and a one year land surveying period of measurable field based surveys of physical features gave a well balanced view. The research showed that the natural landscape has been altered dramatically by settlement and associated infrastructure development. In particular, the loss of dunefields and the artificial modification of river paths were major impact areas. Beach erosion is a continual issue for the peninsula residents, particularly in St Francis Bay.
- Full Text:
- Date Issued: 2015
- Authors: Schroeder, Daniel Heiko
- Date: 2015
- Subjects: Coast changes -- South Africa -- Saint Francis, Cape , Peninsulas -- South Africa -- Saint Francis, Cape , Human ecology -- South Africa -- Saint Francis, Cape , Geographic information systems -- South Africa -- Saint Francis, Cape , Surveying -- South Africa -- Saint Francis, Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5086 , http://hdl.handle.net/10962/d1018203
- Description: A large proportion of the human population, their settlements and socioeconomic activities occur on land directly adjacent to the coastline. The increased demand for coastal leisure and tourism has interfered with natural landscape features and their associated processes. The Cape St Francis/St Francis Bay peninsula located on the southeast coast of South Africa was rapidly developed and transformed from a little fishing village into an urban coastal developed area over a 50-year period (1961-2014). A system that once existed in a state of dynamic or non-equilibrium was interfered with through anthropogenic disturbances, resulting in more frequent and intense natural events, which ranged from floods to debris flows, decreased sand supply and resulting beach erosion. The aim of the project was to identify and map landscape features and changes on the peninsula using an interdisciplinary approach. The triangulated methods of a desktop study using Geographic Information Systems (GIS) and media reviews, a crowdsourcing/participatory approach based on interviews, and a one year land surveying period of measurable field based surveys of physical features gave a well balanced view. The research showed that the natural landscape has been altered dramatically by settlement and associated infrastructure development. In particular, the loss of dunefields and the artificial modification of river paths were major impact areas. Beach erosion is a continual issue for the peninsula residents, particularly in St Francis Bay.
- Full Text:
- Date Issued: 2015
Sediment connectivity in the upper Thina Catchment, Eastern Cape, South Africa
- Van der Waal, Benjamin Cornelis Wentsel
- Authors: Van der Waal, Benjamin Cornelis Wentsel
- Date: 2015
- Subjects: Soil erosion -- South Africa -- Eastern Cape , Sedimentation and deposition -- South Africa -- Eastern Cape , Watersheds -- South Africa -- Eastern Cape , Arroyos -- South Africa -- Eastern Cape , Sediment transport -- South Africa -- Eastern Cape , Soil conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4892 , http://hdl.handle.net/10962/d1019754
- Description: [Portion of abstract]: Sediment dynamics are influenced by transformed landscape connectivity in catchments worldwide. The upper Thina catchment, an important high rainfall resource in the northern Eastern Cape, South Africa, is an example of where ongoing subsistence farming on communal land has led to overgrazing and trampling that has initiated large erosive features (e.g. gullies) and river incision. The formation of gullies led to increased hillslope-channel connectivity and the resultant river incision decreased the channel-valley fill connectivity. These two changes in connectivity led to increased sediment export from the catchment that has various down-stream ecological and socio-economic impacts. This study investigates how the change in hillslope-channel and channel-valley fill connectivity has altered the sediment dynamics in the Vuvu catchment, a headwater tributary of the Thina River. A combination of methods were used to assess the changes in hillslope-channel and channel-valley fill connectivity. High resolution aerial images were used to map source features, such as fields, gullies, sheet erosion, landslides, roads and livestock tracks. Topographic and geological characteristics of the source features were extracted using a Geographic Information System. Furthermore, hillslope-channel pathways, such as the natural drainage network, continuous gullies, discontinuous gullies, roads and livestock tracks were mapped and analysed in terms of topographic and geological characteristics. Historic aerial images were assessed to calculate the date the larger gullies began forming. Recent aerial photos and cross sectional surveys of the valley fill were combined to map the various sediment sinks. Particle size and organic content were analysed for flood bench cores and terrace samples. The chronology of the flood benches was determined using unsupported Pb-210 and Cs-137 dating, and determined for the terraces using Optically Stimulated Luminescence dating. Quantitative and qualitative sediment tracing approaches, using mineral magnetic properties, were used to trace the origin of suspended sediment (collected during flood events), sediment stored in the flood benches and sediment stored in the terraces. Hydrological monitoring was used to assess the potential to store sediment on flood benches along the valley fill through flood bench inundation frequency. Hydrological and hydraulic modelling extended the measured inundation frequencies to a 73 year period and other cross sections along the valley fill. Furthermore, a future scenario of an increased vegetation cover and reduced hillslope-channel connectivity was assessed in terms of channel-valley fill inundation frequency.
- Full Text:
- Date Issued: 2015
- Authors: Van der Waal, Benjamin Cornelis Wentsel
- Date: 2015
- Subjects: Soil erosion -- South Africa -- Eastern Cape , Sedimentation and deposition -- South Africa -- Eastern Cape , Watersheds -- South Africa -- Eastern Cape , Arroyos -- South Africa -- Eastern Cape , Sediment transport -- South Africa -- Eastern Cape , Soil conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4892 , http://hdl.handle.net/10962/d1019754
- Description: [Portion of abstract]: Sediment dynamics are influenced by transformed landscape connectivity in catchments worldwide. The upper Thina catchment, an important high rainfall resource in the northern Eastern Cape, South Africa, is an example of where ongoing subsistence farming on communal land has led to overgrazing and trampling that has initiated large erosive features (e.g. gullies) and river incision. The formation of gullies led to increased hillslope-channel connectivity and the resultant river incision decreased the channel-valley fill connectivity. These two changes in connectivity led to increased sediment export from the catchment that has various down-stream ecological and socio-economic impacts. This study investigates how the change in hillslope-channel and channel-valley fill connectivity has altered the sediment dynamics in the Vuvu catchment, a headwater tributary of the Thina River. A combination of methods were used to assess the changes in hillslope-channel and channel-valley fill connectivity. High resolution aerial images were used to map source features, such as fields, gullies, sheet erosion, landslides, roads and livestock tracks. Topographic and geological characteristics of the source features were extracted using a Geographic Information System. Furthermore, hillslope-channel pathways, such as the natural drainage network, continuous gullies, discontinuous gullies, roads and livestock tracks were mapped and analysed in terms of topographic and geological characteristics. Historic aerial images were assessed to calculate the date the larger gullies began forming. Recent aerial photos and cross sectional surveys of the valley fill were combined to map the various sediment sinks. Particle size and organic content were analysed for flood bench cores and terrace samples. The chronology of the flood benches was determined using unsupported Pb-210 and Cs-137 dating, and determined for the terraces using Optically Stimulated Luminescence dating. Quantitative and qualitative sediment tracing approaches, using mineral magnetic properties, were used to trace the origin of suspended sediment (collected during flood events), sediment stored in the flood benches and sediment stored in the terraces. Hydrological monitoring was used to assess the potential to store sediment on flood benches along the valley fill through flood bench inundation frequency. Hydrological and hydraulic modelling extended the measured inundation frequencies to a 73 year period and other cross sections along the valley fill. Furthermore, a future scenario of an increased vegetation cover and reduced hillslope-channel connectivity was assessed in terms of channel-valley fill inundation frequency.
- Full Text:
- Date Issued: 2015
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