Masters Degrees (Geography and Environmental Studies)
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- Item2-D and 3-D proximal remote sensing for yield estimation in a Shiraz vineyard(Stellenbosch : Stellenbosch University, 2020-03) Hacking, Christopher James; Poblete-Echeverria, Carlos; Poona, Nitesh; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: Precision viticulture aims to minimise production input expenses through the efficient management of vineyards, yielding the desired quantity and quality, while reducing the environmental footprint associated with modern farming. Precision viticulture practices aim to manage the inherent spatial variability in vineyards. Estimating vineyard yield provides insight into this process, enabling informed managerial decisions regarding production inputs. At the same time, yield information is important to the winery, as it facilitates logistical planning for harvest. Traditional yield estimation methods are destructive by nature and require in-situ sampling, which is labour-intensive and time-consuming. Proximal remote sensing (PRS) presents a suitable alternative for estimating yielding a non-destructive manner. PRS employs terrestrial proximal sensors for data acquisition that can be combined with computer vision (CV) techniques to process and analyse the data, generating the estimated yield for the vineyard. This research intends to investigate 2-dimensional (2-D) and 3-dimensional (3-D) PRS and related CV techniques for estimating yield in a vertically shoot position (VSP) trellised Shiraz vineyard. This research is presented as two components. The first component evaluates 2-D and 3-D methodologies for estimating yielding a vineyard. Three experiments are presented at bunch-and plant-level, incorporating both laboratory and in-situ experimental conditions. Under laboratory conditions (bunch-level only), the 2-D methodology achieved an r2 of 0.889, while the 3-D methodology achieved a higher r2 of 0.950. Both methodologies demonstrate the potential of PRS and associated CV techniques for estimating yield. The in-situ plant-level results favoured the 2-D methodology (fullcanopy (FC): r2= 0.779; leaf removal (LR): r2= 0.877) over the 3-D methodology (FC: r2= 0.487; LR: r2= 0.623). The general performance of the 2-D methodology was superior, and thus implemented in the subsequent component. The two set out to determine the ideal phenological stage for estimating yield. The 2-D methodology was employed with slight improvements and multitemporal digital imagery were acquired on a weekly basis for 12 weeks; culminating in a final acquisition two days prior to harvest. This component also successfully implemented image segmentation using an unsupervised k-means clustering (KMC) technique, an improvement to the colour thresholding (CT) technique implemented in component one. The ideal phenological stage was approximately two weeks prior to harvest (final stages of berry ripening), which achieved a global (bunch-level: 50 bunches) r2of 0.790 for estimating yield. This research successfully implements 2-D and 3-D PRS and CV techniques for estimating yield in a Shiraz vineyard, and thereby accomplishes the aim of this research. The research demonstrates the suitability of the methodologies–specifically the 2-D methodology, which demonstrated superior performance (simple data acquisition and analysis with competitive results). Future research could refine the presented methodologies for operational use.
- ItemAdvancing disaster risk management in an ecological context: the case of veldfire management in South Africa(Stellenbosch : Stellenbosch University, 2023-03) Forsyth, Gregory Graham; De Klerk, Helen; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: Worldwide vegetation fires in peri-urban and rural settings pose a major hazard to social, economic and environmental assets. In South Africa, such fires are known as veldfires and they are necessary for maintaining natural processes in the fynbos, savanna and grassland biomes. Paradoxically, despite veldfires being ecologically beneficial, they often pose a risk to people and their property. This is especially so in the wildland–urban interface where buildings are found in the proximity of flammable vegetation. South Africa’s National Veld and Forest Fire Act, No. 101 of 1998 (South Africa 1998) provides a framework for setting priorities for veldfire management including the establishment of Fire Protection Associations (FPA). It seeks to find a balance between reducing risks to human lives and livelihoods while maintaining fire regimes which look after the functioning of fire-adapted ecosystems. Risk management offers a way for implementing this legislation and the National Veldfire Risk Assessment, completed in 2010, used risk management principles to establish the relative levels of veldfire risk in each of the country’s district and local municipalities. No detailed examination has been carried out of the applicability of the National Veldfire Risk Assessment framework and accuracy of nationally-generated veldfire risk information at local scales. This research addresses the gap between the National Veldfire Risk Assessment and how implementable this is to Fire Protection Associations and, at a finer scale, the wildland-urban interface. It examined three study areas typifying different spatial scales, climates, land-use practices, fuel types and assets at risk. It provides a systematic, stepwise, replicable, scalable assessment framework for determining veldfire risk that is in line with national policy (legislation). Importantly, it involves local stakeholders, and uses sound scientific ecological knowledge and established risk management principles to develop an accessible and practical methodological “tool” to identify different categories of risks at a range of spatial scales. In determining the risk, the likelihood of veldfire occurring was established, using combinations of the vegetation type and age, with the premise that the more flammable the vegetation the more likely a veldfire will occur. Consequences were decided on by identifying the types of buildings present and categorising the social and economic impacts should veldfire damage or destroy these buildings. The results were then mapped to show where vulnerable assets in the landscape are exposed to veldfires and in so doing enabling veldfire authorities to allocate resources according to the levels of risk present. This research has developed an accessible and practical “tool” to identify different categories of risks at a range of spatial scales and confirmed the relevance, applicability and scalability of the National Veldfire Risk Assessment framework. Adopting this approach will assist fire authorities to spend available budgets more effectively with more emphasis being placed on preventing rather than merely responding to veldfires. It will also assist in prioritising risk mitigation measures to prevent the inevitable future veldfires becoming disasters.
- ItemAgricultural field boundary delineation using earth observation methods and multi-temporal Sentinel-2 imagery(Stellenbosch : Stellenbosch University, 2019-12) Watkins, Barry; Van Niekerk, Adriaan; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: Accurate and up-to-date agricultural monitoring systems are critical for forecasting crop yield, planning resources and assessing the impact of threats to production (such as droughts or floods). The spatial extent and location of agricultural fields greatly influence these systems. Conventional methods of delineating agricultural fields, such as in situ field surveys and manual interpretation of imagery, are costly and time-consuming and are thus not suitable in an operational context. Automated earth observation techniques offer a cost-effective alternative as they can be used to execute frequent and highly detailed investigations of large areas. However, there are currently no well-established and transferable techniques to automatically delineate agricultural field boundaries. The most promising techniques found in literature include object-based image analysis (OBIA) and edge detection algorithms. This study consequently compared and evaluated multiple OBIA approaches for delineating agricultural field boundaries with multi-temporal Sentinel-2 imagery. Two sets of experiments were carried out. The first set of experiments compared and evaluated six multi-temporal OBIA approaches with which active agricultural fields in a large irrigation scheme were delineated and identified. These approaches combined two edge enhancement algorithms (Canny and Scharr) and three image segmentation techniques (watershed, multi-threshold and multi-resolution) to create six scenarios. Results showed that the watershed segmentation scenarios outperformed the multi-threshold and multi-resolution segmentation algorithms. In addition, the Canny edge detection algorithm, in conjunction with a segmentation technique, was found to produce higher boundary accuracies than its counterpart, Scharr. In the second set of experiments the best performing scenario from the first set of experiments, namely Canny edge detection in conjunction with watershed segmentation (CEWS), was modified slightly and applied to five regions in South Africa. The purpose of this investigation was to assess the robustness (transferability) of the methodology. A standard per-pixel supervised classification was performed to serve as a benchmark against which the CEWS approach was compared. Results showed that CEWS outperformed the supervised per-pixel classification in all experiments. CEWS’ robustness in different agricultural landscapes was furthermore highlighted by its creation of closed field boundaries, independence from training data and transferability. The quantitative experiments carried out in this study lay the foundation for the implementation of an operational workflow for delineating agricultural fields with the use of multi-temporal Sentinel-2 imagery. The extracted field boundaries will likely aid agricultural monitoring systems in estimating crop yield and improve resource planning and food security assessments.
- ItemAgritourism : market segmentation profile of potential and practising agritourists(Stellenbosch : Stellenbosch University, 2003-04) Speirs, Lindsay Justine; Van der Merwe, J. H.; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: Rural tourism and agritourism are in their infant stages in South Africa. It benefits the farmer, the local community, the rural area, the tourist and the country. It is therefore a viable option but requires more research, management, planning and control for it to be successful. Many agritourism ventures are not as successful as they should be. The problem is that farmers/landowners do not research the demand for tourist products before they deliver them and do not know whom they are catering for. To stay competitive, the tourists' characteristics ought to be understood. This would provide insight into what facilities and services to supply, what resources to utilise and how to promote the agritourism destination. The aim of this study was to segment the potential and practising agritourists into different clusters, according to their preferences, and to investigate the clusters' characteristics and behaviours. The objectives were to: 1. Investigate the potential and practising agritourists' socio-economic, demographic and travel characteristics. 2. Rate all the attractions, activities and services according to their popularity. 3. Clarify the preferences of these tourists, concerning attractions and activities, by combining similar ones. 4. Divide the tourists into clusters of similar preferences. 5. Compare the socio-economic, demographic and travel characteristics of the different clusters of tourists. 6. Produce a set of guidelines for entrepreneurs/farmers/landowners, as to what tourist products they should supply or develop, and for whom, and how they should market them. This study entailed distributing questionnaires to potential and practising agritourists at shopping centres and farms involved in agritouri'swimming', 'picnicking', 'scenic drives', 'dams/lakes/pans' and 'small game' were the most popular agritourism attractions and activities. Factor analysis was used to reduce the number of variables by combining like variables (attractions) and cluster analysis was utilised to segment the respondents into five clusters of tourists with similar preferences for agritourism attractions and activities. Cross tabulation, frequencies and descriptive statistics were used to describe these different clusters. These groups of tourists were described according to their demographic, socio-economic and travel characteristics. Segmenting tourism markets and compiling profiles of the tourists within each sub-market has proved to be advantageous. Once the demands of the tourists are known, the appropriate facilities and number of facilities can be developed. Knowing who the tourists are and where to target them, will lead to better marketing, planning and promotion of the destination. Customer satisfaction will be increased, as it is known exactly who must be catered for, thereby resulting in repeat visits. The five clusters of tourists were: 'general nature tourists'; 'urban tourists'; 'hard outdoor adventure tourists'; 'visual or soft outdoor adventure tourists'; and 'agritourists'. All these tourists, except 'urban tourists', are excellent potential agritourists. The results of this study were used to compile guidelines for entrepreneurs. These guidelines could help them in deciding who to target (which clusters), what agritourism products to develop (attractions, activities and services) and how to market them (means of advertising). Appropriate accommodation types and the availability of equipment and facilities for activities also act as attractions. This study demonstrates an inexpensive method of gathering information about tourists, thereby improving marketing and planning approaches. It illustrates how the potential and practising agritourists can be divided into sub-markets. The agritourism market is a heterogeneous market and must therefore be segmented. Any entrepreneur can use the results of this market segmentation. Any future studies, similar to this one, could consist of a sample much larger. As this study was primarily based in the Western Cape, similar research should be executed in other distinct regions. It would be illuminating to see how the groups of agritourists vary according to geographical areas.
- Item'n Alternatief tot die voorsiening van plaaswerker behuising(Stellenbosch : Stellenbosch University, 1999-12) Stoumann, Deone; Pienaar, W. P.; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography & Environmental Studies.ENGLISH SUMMARY: South Africa is undergoing a process of rapid change focusing on the improvement of the living standards of previous disadvantage communities. In this context farmworkers are identified as an important part of such previous disadvantaged groups. Farmworkers in South Africa were traditionally housed through a system of tied-housing, which has resulted in their dependency on the farmer. This system is deeply rooted in the Western Cape and has a strong paternalistic base. For the first time in South African's history there is an opportunity for farmworkers to change or reduce their dependency. The new governmental subsidy scheme as well as the Draft policy for the implementation of long term security of tenure, present farmworkers 'with the opportunity to improve their living conditions, without the traditional ties to the farmer. Against this background agri-villages are considered as an alternative to traditional farmworker housing. An agri-village is a private settlement established and managed by a legal institution that is situated within an agricultural area and where residence is restricted to bona fide farm workers and their dependants. Security of tenure can be achieved according to a lease contract or usufract because the land and home stays the property of the legal institution. The theoretical and case studies that were undertaken indicated that the concept of agri-villages is in theory a viable strategy for farmworkers to reduce dependency. However agri-villages cannot merely be developed in every region in South Africa without taking cognisance of the specific needs and characteristics of each community.
- ItemAlternative land uses to forestry in the Western Cape : a case study of La Motte plantation(Stellenbosch : Stellenbosch University, 2003-12) Fernandes Ruiz, Ricardo; Zietsman, H. L.; Rozanov, Andrei Borisovich; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: The South African government started the restructuring process of the state’s forest assets in 1998. The privatisation process includes all the assets of the South African Forestry Company (SAFCOL) and half of the former homelands’ 150 000 hectares of forest. In August 2000 SAFCOL released their “Operational Plan for Implementing Exit from Forestry in the Southem-Cape Portion of the Western Cape Region”. This plan identified only major land uses (agriculture, forestry, and conservation). A more detailed and intensive land evaluation study was required to specify land utilisation types that are tailor-made to each land unit of the study area. The main intention of this research study is to develop a more detailed evaluation process that elaborates on the land uses proposed by SAFCOL, which is site-specific in terms of the type of agricultural system to be used on specific areas, or the type of indigenous vegetation to be restored in conservation areas. La Motte plantation was taken as the case study and the SAFCOL digital database for the study area was used as the input data. The Automated Land Evaluation System (ALES) was the computer software package used to build the expert system to evaluate land according to the method presented in the FAO 1976 report. The ALES model built in this research study had 15 decision trees (one per land utilisation type) resulting in a total of 1678 branches, which relate land characteristics to severity levels of land qualities. During the computation of an evaluation ALES attempts to place each map unit into one of the four severity levels of land qualities within each landutilisation type. Physical suitability of each land unit for each land utilisation type was determined by the maximum limitation method. ALES is not a GIS and does not by itself display maps. The evaluation result matrix was exported into ArcMap for further optimisation and geographical analysis to enable the spatial representation of the results. After completion, taking into account the theoretical background, optimal terrain units were identified for the different land uses considered and the results are presented as tables and maps. Fynbos is the most suitable alternative land use for the study area followed by Pears, Sauvignon Blanc and Chardonnay vines. Pinotage, Shiraz, Cabernet Sauvignon and Cabernet Franc vines were least suitable as alternatives. The study found that the SAFCOL’s database is not sufficient to meet the requirements of a detailed site-specific land evaluation process. The polygon attribute table of the soil coverage only provided a subset of the land characteristics necessary to build and run the model. Data fields like soil form, depth, drainage, wetness, terrain type, aspect and climatic information had to be created because most of the data provided were in a non-digital form. The database was not complete and more precise data are needed to improve the system.
- ItemAnalysing determinants of housing tenure A cross sectional analysis in the City of Tshwane Metropolitan(2019-04) Maringa, Tirhani Lucky; Geyer, Herman; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental StudiesENGLISH ABSTRACT: According to the census 2011 tenure is, divided into five categories: “Owned but not yet paid off”, “Owned and fully paid off”, “rented”,“occupied and rent free” and “tenure other”. The integral focus of the study is on owned tenure sourced with other related variables from the 2011 census data. Thus the purpose of the study was to explore spatially the critical factors that influence the distribution of owned tenure in the Tshwane Metropolitan Municipality, in order to model households’ housing career and locational mobility by household head (HH) age and population group in different income areas. The study applied a bivariate correlation, geographic weighted regression analysis in order to ascertain stages in which households attained owned tenure in relation to socio-demographic and economic variables. Ordinary Least Square (OLS) modelled spatially the varying relationships and determined homogenous groupings in terms of their randomness, the results of the study revealed that the hypothesis was true with the findings that “Owned, but not fully paid off” tenure was in large proportion at “HH age group 35 –49”. However, such tenure was also larger for the white population group at “HH age group 20 –34” compared to other groups. Unfortunately, “Owned and fully paid off” tenure contradicted the hypothesis on the basis that it was dominant and larger at HH age groups above 50. Moreover, both types of ownership were highly clustered in specific areas within the study area.
- ItemAn analysis of eco-labelled honey practices employed in the South African beekeeping industry : implications for agricultural sustainability(Stellenbosch : Stellenbosch University, 2021-12) Hendricks, Lindi Leela; Williams, Samantha; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH SUMMARY : This thesis presents a novel area of research for agricultural sustainability in South Africa, within the field of Geography and Environmental Studies. Previous studies on eco-labels in South Africa focussed on the commercial aspects such as the consumer understanding and perceptions (Stausebach, 2016; Struwig and Adendorff, 2018) and its application in ecotourism (Pieterse, 2004), rather than the primary sector activities associated with it such as beekeeping. The application of eco-labels in viticulture for biodiversity (Bridgman, 2009) was among the only other sampled literature in the agricultural sector of South Africa, highlighting a gap for further research. Eco-labels serve as a marketing tool to consumers, based on the environmental considerations and performance of a product. For this study they were employed as a measure to determine its efficacy for agricultural sustainability in the beekeeping industry (apiculture) in South Africa. Beekeepers across the country participated in this study to share insight on their harvesting techniques. Their responses provided in the interviews and survey conducted, assisted with understanding how eco-labelled honey is implemented in the beekeeping industry in South Africa. These eco-labels included “Badger- Friendly”, “Fairtrade”, “Pure”, “Organic”, “Raw”, “Monofloral”, “Wild Honey” as well as the “Mobius Loop”. Based on a comparative analysis of the eco-label requirements as per the literature review in contrast to the results of the study, it indicated that there are some misconceptions and subsequent misuse of the eco-labels by industry role-players. The ecolabels were either not fully understood or adhered to accordingly. This highlights that further studies are warranted to raise the level of awareness for agricultural sustainability, in the hope of instituting environmental policy changes and reform to this sector.
- ItemAn analysis of the continued resurfacing of illegal backyard dwellings settlements : a case study of Mbare Residential Suburb in Harare(Stellenbosch : Stellenbosch University, 2018-03) Chirowodza, Primrose; Geyer, Herman; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography & Environmental Studies.ENGLISH ABSTRACT: The spatial growth of irregular settlements in cities of less developed countries reflects increasing disparities in the distribution of wealth and resources. 25-70% of the urban population in African countries is living in irregular settlements, squatter settlements, unauthorised land development, rooms and flats of dilapidated buildings in city centre (Lasserve & Royston 2002). Even though massive destruction operations like Murambatsvina are being carried out in these African countries to mention just a few Zimbabwe, Tanzania and Malawi. These illegal structures are still mushrooming in African countries. This study seeks to find the underlying factors behind the continued resurfacing of these illegal dwellings in Mbare Harare. The study also looked at how migration and urbanisation determine the processes and affects informality in Zimbabwean.
- ItemAnalysis of the fire hazard posed by petrol stations in Stellenbosch and the extent to which planning acknowledges risk(Stellenbosch : Stellenbosch University, 2019-04) Qonono, Kwanele; Pharoah, Robyn; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography & Environmental Studies.ENGLISH ABSTRACT: The study aimed to investigate the extent to which land-use planning in Stellenbosch, South Africa, considers the fire-risk posed by petrol stations, and the implications for public safety, as well as preparedness for large fires or explosions. In order to achieve this, the study first identified the land-use types around petrol stations in Stellenbosch, and determined the extent to which their locations comply with the international and national planning regulations. Petrol stations within a six-kilometre radius from Stellenbosch’s centre were used as study sites. Second, the study examined the risk of fires/explosions at petrol stations. Third, the study investigated Stellenbosch Municipality’s institutional preparedness to respond in an event of a fire/explosion at a petrol station. These results suggest that the siting of petrol stations does not comply with the international and national good practices, thus exposing the surrounding developments to fires and explosions. The results also suggests that land-use planning does not consider hazards created by petrol stations. In addition, while observation at petrol stations suggest the potential for major fires, Stellenbosch Municipality’s preparedness to respond to petrol station fires appears low, due to the prioritisation of more frequent events.
- ItemAnalysis of traffic accidents in Gaborone, Botswana(Stellenbosch : University of Stellenbosch, 2009-03) Pego, Maeletso; Ferreira, S. L. A.; University of Stellenbosch. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.Botswana, a developing country in southern Africa, has not been spared the proliferating scourge of traffic accidents that is sweeping across the world. After HIV/AIDS, traffic accidents are the second largest cause of unnatural deaths in Botswana. The country is losing two per cent of its GDP every year to traffic accident costs. Furthermore, road safety is one of the major challenges the country will have to overcome in order to achieve its Vision 2016. This study investigates traffic accidents in Gaborone, the capital city of Botswana, for the years 2000 and 2005. The study analyses the characteristics of traffic accidents, examines their causes, maps the spatial distribution of traffic accidents for 2000 and 2005, and outlines the countermeasures government is instituting to curb accidents. The main data on traffic accidents used was extracted from the microcomputer accidents analysis package V5.0 (MAAP 5) obtained from the Traffic Police Division. Semi-structured interviews with transport and safety officers, traffic police and other stakeholders were conducted. The interviews were mainly about what government is doing to reduce the carnage caused by traffic accidents. Existing reports were also used as data sources. Microsoft Excel and ArcGIS 9.1 packages were used to do the analyses. The road casualties of drivers/riders are concentrated in the economically active age category of 15-64 years (95% for all casualties). In particular, the casualties are very high in the 20-39 age cohort with one third and three quarters of all casualties for 2000 and 2005 respectively. In addition, driver casualties by gender for the 20-39 age cohort show a high representation of males, namely 57% and 64% for 2000 and 2005 respectively.
- ItemApplication of differential person and household growth in the Gauteng city-region, 2001-2011(Stellenbosch : Stellenbosch University, 2018-03) Iturralde, Diego; Du Plessis, Danie; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography & Environmental Studies.ENGLISH ABSTRACT: This study deals with differential person and household growth at electoral ward level for the period 2001 – 2011 for the Gauteng City-Region. From a theoretical perspective such growth at such small area level is very valuable when dealing with issues around urban growth and urbanisation and the characteristics that this brings. At a spatial level, the manifestation of growth is critical in terms of picking up changes in its structure and distribution. Differential urbanisation has been seen to take place in other parts of the world whereby growth shifts from places in the urban core to intermediate cities and even onto smaller places before the cycle repeats itself. These urban development cycles are important to take note of and to track over time in order to be able to react to changing patterns of urban growth. In this regard it is important to appreciate what drives growth and how this plays into the realm of how a region moves a process of decentralisation to one of reurbanization and the impact this has for spatial and urban planning. This study made use of the 2001 and 2011 Census harmonised to the 2011 boundaries and using the standard deviation measure within a Gaussian distribution to create six categories of growth, three either side of the mean that are divided by one and two standard deviations. The study then showed characteristics for various characteristics for different levels of person and household growth before establishing spatial trends and patterns that identified hotspots in the city-region and in the metros of Gauteng on their own as well as identifying clustering and outliers of growth for the city-region and metros alone as well. The study identified some key findings in the shape of there being a strong urban core that drives most growth in the city-region; the mining industry along the mining belt stretching from the West Rand in Westonaria all the way north up to Rustenburg in the North West province showed its own unique trends and characteristics; and finally there is a definite trend across the city-region to move away from areas with poor service delivery towards areas that provide good quality of living with quality and reliable delivery of services.
- ItemThe application of synthetic aperture radar for the detection and mapping of small-scale mining in Ghana(Stellenbosch : Stellenbosch University, 2020-12) Denner, Maria Gabrielle; Kemp, Jaco; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: Artisanal and small-scale mining (SSM) is a cause of major environmental concern in developing countries. In Ghana, SSM is a mixture of legal and illegal operations where illegal mining is referred to as “galamsey”. Earth observation techniques can assist local governments in regulating SSM activities by providing specific spatial information on the whereabouts of SSM mines. The tropical climate in Ghana, however, hinders the regular flow of useful optical imagery due to a high percentage of cloud cover for most parts of the year. Synthetic aperture radar (SAR) can overcome this limitation. The study area includes a portion of the Ofin River near the mining town of Obuasi, Ghana. The area is tropical in climate, rural and dominated by forests. This study aims to assess the accuracy and reliability of applying SAR for the detection and mapping of small-scale mining in Ghana with classification and change detection analysis. A literature review on remote sensing and image processing literature was conducted. The satellite imagery collected for the study included single-date C-band Sentinel-1, a time series of Sentinel-1 and a single-date X-band KompSAT-5 image for the SAR analysis with Sentinel-2 and Landsat-8 imagery as ground truth datasets. Classification analysis was conducted in two experiments which included the analysis of two classification schemes, i.e. multi-class-and a binary-water classification scheme. The first experiment assessed the accuracy of random forest classification applied to single-date Sentinel-1, KompSAT-5 and multi-temporally filtered Sentinel-1 databases. The second experiment was a comparison of five machine learning supervised classification methods applied to the multi-temporally filtered Sentinel-1 database. The potential of change detection on Sentinel-1 time series data was analysed in the third experiment for the detection of SSM. Image differencing was applied and two threshold methods were tested for producing the most accurate change maps.The classification with the object-based image analysis approach was successful in classifying water bodies associated with SSM. The multi-temporally filtered Sentinel-1 dataset was the most reliable with kappa coefficients at 0.65 and 0.82 for the multi-class classification scheme and binary-water classification scheme respectively. The single-date Sentinel-1 dataset has the highest overall accuracy at 90.93% for the binary water classification scheme. The KompSAT-5 dataset only achieved the lowest accuracy at an overall accuracy of 80.61% and a kappa coefficient of 0.61 for the binary-water classification scheme. The results of the change detection analysis indicated that the Sentinel-1 imagery was able to detect and map SSM. The change detection analysis also showed the potential of discerning active from abandoned mines, but this has to be further investigated.
- ItemApplications of dairy wastewater as a fertilizer to agricultural land : an environmental management perspective(Stellenbosch : University of Stellenbosch, 2009-03) Torr, Leigh Christine; Schloms, B. H. A.; University of Stellenbosch. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.As with any form of intensive agriculture, there are potential environmental impacts associated with the management and housing of livestock on dairy farms. Within the field of dairy farming, particular focus falls to the issue of environmental degradation of water resources, as this form of pollution is currently a major environmental issue around the world. Conventional agricultural practices involving the application of chemical fertilizers to land and crops are causing environmental problems as a result of poor management practices. Dairy wastewater and manures could however be a valuable resource for agricultural producers in the form of an alternate fertilizer for their crops. Waste application as a fertilizer is more environmentally friendly than chemical fertilizers, and could drastically reduce costs for farmers, whilst alleviating storage and management problems often associated with farmyard manures (FYM). The application of organic wastes, notably livestock manures, to land has historically been important for maintaining soil fertility on farms in terms of nutrient status and organic matter levels, as well as helping to reduce soil erosion and improve waterholding capacity. The research sought to investigate the environmental and economical feasibility of using dairy wastewater and manures as an alternative form of fertilizer within agriculture in South Africa.
- ItemApplying remote sensing and spatial analysis to investigateregime shifts in the Albany Thicket of the Baviaanskloof(Stellenbosch : Stellenbosch University, 2023-03) Matowanyika, Danai; De Klerk, Helen; Maciejewski, Kristine; Biggs, Reinette, 1979-; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: Human activities have greatly altered the environment, the scale of impact has led to a new geological epoch - the Anthropocene. Of particular concern in this new era is the possibility for regime shifts: large, persistent changes in the structure and function of ecosystems that can have substantial impacts on human well-being and livelihoods. The Baviaanskloof is a semi-arid ecosystem in Southern Africa that has been substantively transformed by human activities. The Baviaanskloof, is located in the unique Thicket biome, characterized by dense spekboom thicket vegetation (Portulacaria Afra). Remote sensing and geoinformatics tools were used to investigate possible regime shifts in the Baviaanskloof, with a focus on regions classified as Baviaanskloof Thicket biome. The regime shift being investigated is the potential shift from an intact Thicket to a pseudo-Savanna Thicket regime. The thesis combined remotely sensed Enhanced Vegetation Index (EVI) from the MODIS platform as a surrogate of biomass and rainfall data from local weather stations over the period 2000 – 2018, complemented with observations from a field visit in Baviaanskloof Heartland area (BHB) in 2018. The BHB has been an active site for ongoing spekboom rehabilitation initiatives. Analytical tools, Break Detection for Additive Seasonal and Trend (BFAST), Sequential t-Test Analysis for Regime Shifts (STARS) and Green-Brown were used to investigate potential regime shifts. Different tools analysed different aspects of biomass changes in the Baviaanskloof, generally showing persistent decreases. Green-Brown showed that majority of the Baviaanskloof did not experience significant annual changes, but experienced significant seasonal changes. Most of the significant changes were decreases in biomass, with 58% of the Bavianskloof experiencing seasonal decreasing trend.Within the Thicket biome specifically, 77% of the area experienced significant biomass decreases. Majority of the changes occurred in the more arid vegetation classes (Groot Arid Spekboomveld), a possible early warning indicator of what lies ahead for the biome. BFAST and STARS detected two major breaks points in the Thicket biome in 2004 (2001 for STARS) and 2011. BFAST showed a decreasing trend of biomass in between and after both break points. STARS also identified a period of relatively low biomass between 2001 and 2011, a period of relatively higher biomass between 2011 and 2016, and a drastic drop in biomass after 2016 in the Thicket biome. The magnitude of the second break points is bigger than that of the first break points for both models. Spatial mapping of breakpoints showed majority of the Thicket biome (87.91%) experienced at least two break points, mostly negative break points experienced in the drier Groot Arid Spekboomveld regions. The thesis also anaylsed the effect of rehabilitation efforts at specific sites within the BHB. The BHB spekboom plantings of 2010-2013 initially showed an increase in biomass, followed by a decreasing trend. This variations in biomass patterns show that the Baviaanskloof is a complex system with spatial and temporal dynamism. The geoinformatics and analytical tools used in this study provided meaningful insights into investigating possible regime shifts in the Baviaanskloof, and was able to analyse these spatially and detect significant break points. This points to the potential for these tools in detecting regime shifts.
- ItemApplying the city development index (CDI) to measure the quality of life of the local municipalities in the northern Cape between 2001 and 2011(Stellenbosch : Stellenbosch University, 2015-03) Kruger, Christa Jacoba; Willemse, Lodene; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography & Environmental Studies.ENGLISH ABSTRACT: The quality of life (QOL) concept is important because it influences people's behaviour. Consequently, knowing what people perceive as a good or poor QOL will allow planners to predict their behaviour. After 20 years of democracy South Africa still struggles with issues such as poverty and inequality. The Northern Cape has a unique settlement pattern that makes it very difficult to reach all of the municipalities equally and to provide services of the same standard. The aim of this study is therefor to determine if the QOL has increased or decreased for the municipalities of the Northern Cape and to determine which municipalities are doing better than what others are. The City Development Index (CDI) will be used to determine the QOL in the municipalities of the Northern Cape for 2001 and 2011 in order to make the comparisons. The CDI results show that the figures for 2011 are mostly above 0.5. The results point out that income and infrastructure remain two significant issues in the Northern Cape. This study will allow planners to use the QOL results in the Northern Cape and adjust their plans accordingly in an effort to have an improved QOL by enhancing the provision and distribution of scarce resources, infrastructure, service delivery and facilities
- ItemAre the walls giving way to fences? Is racial integration within Kwadukuza municipality leading to income based class segregation(Stellenbosch : Stellenbosch University, 2014-12) Singh, Vishanth; Van Eeden, Amanda; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: The racial and development imbalances created by apartheid have left a profound impact on the urban and social landscape in South Africa. Despite it being 20 years into the dawn of a new South Africa, many parts of society are still bearing the brunt of the harsh impacts of apartheid. The first democratic elections in 1994 heralded a new era of hope and optimism for a better life in a racially integrated country. However 20 years into democracy, just how much has society integrated? Literature suggests that, in the absence of legally enforced segregation as with apartheid, society will segregate itself on class or other factors. This study measures if changes in racial integration within KwaDukuza Municipality is leading to class based segregation. The study makes use of the Neighbourhood Diversity Index, to measure changes in racial integration within the study area. A Geographic Weighted Regression model was then used to determine if there is a relationship between racial integration and income that could explain the transference from racial to classed based segregation. The study found that although low levels of racial integration have taken place within KDM, the coastal areas of the municipality have become increasingly segregated over the last 20 years. The GWR model found that there is positive relationship between income and racial segregation in these coastal areas. This study highlights that politicians, decision makers, town and social planners still face a long and socially demanding challenge in redressing past imbalances and promoting integration by breaking down the current trend of class based segregation.
- Item'n Argeologiese ondersoek van historiese nedersettingspatrone in die westelike Overberg(Stellenbosch : Stellenbosch University, 1993-12) Rademeyer-De Kock, C. (Chantelle); Deacon, H. J.; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.AFRIKAANSE OPSOMMING: Hierdie tesis is n studie van landelike nedersettings in die westelike Overberg in die laat agtiende eeu en in die neentiende eeu. Historiese bronne en argeologiese opnames dra by tot die data rakende die ontwikkeling en organisasie van 18 plaaswerwe wat bestudeer is. Twee tipes nedersettings (werwe) word identifiseer naamlik eenvoudige (lae status) veeposstelsels en meer komplekse gemengde boerdery werwe. Die geskiedenis van grensuitbreiding en die sigbaarheid daarvan in die westelike Overberg toon n duidelike verkleining in skaal van strukture en 'n afskaling van stutussimbole in vergelyking met die Boland. Daar is tot die slotsom gekom dat die studie van stoflike kultuur in die westelike Overberg n belangrike onderdeel verteenwoordig van interpretasies van die nedersettingsgeskiedenis in die streek. Aanbevelings word gemaak ten opsigte van die bewaring van bogenoemde nedersettings.
- ItemAssessing the groundwater resources within the Table Mountain Group using remote sensing and geographic information system(Stellenbosch : Stellenbosch University, 2003) Matoti, Andiswa; Schloms, B.; Van Niekerk, Adriaan; Stellenbosch University. Faculty of Science. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: The Cape Town metropolitan area has limited water supply due to rapid population and urban growth. In many instances, surface water is the only source in water supply schemes. There is a need for additional water supplies to supplement the existing water sources. Groundwater systems can be used as primary or supplemental water supply sources especially in areas where there is high demand for water resources. The aim of this study is to evaluate the groundwater potential within the Table Mountain Group (TMG) with the assistance of remote sensing and Geographical Information System (GIS). Previous hydrogeological studies have found the TMG to be the second largest hydrogeological unit in South Africa with extensively fractured and multi-porous rock. The study area is 5660 km2 with TMG covering 1336 km". In this study a Landsat Enhanced Thematic Mapper Plus (ETM+) image was used to identify lineaments. The identified lineaments were overlaid with vegetation, drainage patterns, faults and fractures digitized from 1:250 000 geological maps and borehole yields to show areas with promising groundwater resources. The results did not show correlation between vegetation and lineaments. Most of the lineaments intersected drainage lines at some points, and a few were parallel to the drainage lines. Forty five percent of the digitized faults and fractures overlap with the Landsat lineament. The most dominating lineaments are oriented in a NW-SE direction. High yielding boreholes with average yield of about 12 lIs were found within the distance of 150m from the lineaments. The lineaments were further analysed to locate areas that could be suitable for groundwater exploration. These areas were identified using Landsat lineaments, boreholes and a Digital Elevation Model (DEM). The results showed that the most favourable lineaments and geological features were oriented in a 135-180° and 0-45° direction and areas with slopes of less than 40% were found to be suitable for drilling boreholes. The amount of available groundwater within the TMG was also investigated by looking at both volume of recharge and amount that could be held in storage. Rainfall data was used to estimate recharge. Groundwater recharge was calculated to be 5% of the total precipitation that falls on this area. Based on the average rainfall of 600mm per annum, the results show that TMG has an average recharge value of 30mm per annum. The total recharge for the area covered by TMG, which has an area of 1336km2 , is 160 million nr'. Geological profiles and cross sections were drawn to determine the storage capacity of the TMG, which was estimated to be 525 million m.3 According to a study done by the Department of Water Affairs and Forestry (DW AF) in 1996, the anticipated water demand in the Cape Town metropolitan area will increase from 243 million m3 in 1990 to 560 million m3 in 2020. The estimated volume of water that can be stored within the TMG can meet the current demand for the next 10 years and supplement the existing surface water sources. Groundwater vulnerability of the TMG to contamination was assessed and mapped by using the DRASTIC index. The results demonstrate that the TMG area is at low risk to contamination.
- ItemAssessment of coastal vegetation degradation using remote sensing in False Bay, South Africa(Stellenbosch : Stellenbosch University, 2016-12) Mbolambi, Cikizwa; Luck-Vogel, Melanie; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies.ENGLISH ABSTRACT: The coastal zone, the interface between land and sea, faces much pressure from human activities. These coastal pressures make it difficult for the coastal zones to fulfil their natural functions, so threatening the state of coastal environments and making them vulnerable to coastal disasters and degradation. This study aimed to test whether remote sensing techniques can be implemented to assess the intactness of terrestrial coastal vegetation at the high spatial resolution required for coastal management. The study focused on the northern False Bay coast, Western Cape, South Africa. The research used is a modification of the method developed by Lück-Vogel, O’Farrell & Roberts (2013) which involved image segmentation and a habitat intactness index using image derivatives. The procedure used Worldview-2 (WV-2) images of high spatial, spectral and temporal resolution acquired on 25 February 2014 and 11 October 2014. Both images were pre-processed and segmented into meaningful objects using object-based image analysis (OBIA). Five image derivatives and the eight spectral bands were stacked into a single image to extract field-informed training points. Regression analysis was performed on eight spectral bands and five image derivatives to evaluate the most suitable bands to produce a habitat intactness index in a subsequent decision tree classification. Decision tree classification was generated using two spectral bands, namely the RED and NIR1 bands. These bands were chosen because they gave the best regression results and they are available in most sensors. The bands were also chosen because the study deals with vegetation assessment. The overall accuracy of the results was 80.5% which was a satisfactory result with a kappa value of 0.75 (75%) that indicates a substantial agreement between the remotely sensed result and the reference data. A key finding is the importance of seasonality to delineate natural and alien vegetation which is better achieved in the dry season. Validation of the results was done using the field-validation points of a field visit conducted in June 2016. The output maps generated for habitat intactness consisted of five habitat intactness classes namely highly, moderately and lightly degraded, intact vegetation and alien vegetation. The output maps can be used to inform coastal managers about conservation at a local scale. It is recommended that validation of remote sensing results be done in the same season that satellite images were taken.