The influence of anthropogenic and environmental covariates on the habitat use and density of sympatric carnivores, Limpopo Province, South Africa
- Authors: Faure, J Philip B
- Date: 2020
- Subjects: Carnivorous animals -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48302 , vital:40840
- Description: Carnivores are declining and undergoing substantial range contractions which have largely been attributed to anthropogenic related. Globally, there has been an increase in establishing protected areas for species conservation. However, protected areas may not always effectively conserve all biodiversity, where some areas are too small for viable populations of wide-ranging species, such as leopards Panthera pardus, spotted hyaenas Crocuta crocuta, and brown hyaenas Parahyaena brunnea. The importance of privately-owned areas are gaining increasing recognition for their role in conserving species, and ecosystems. Though such areas may provide key opportunities for the conservation and persistence of biodiversity, little attention (with regards to species conservation planning) is given to these areas. Furthermore, large carnivore populations increasingly have to share the landscapes with humans as the global human population increase. Though anthropogenic impacts can be limited within protected areas, human activities on privately-owned farmlands are mostly dictated by economic activity to sustain human presence (often leading to humancarnivore conflicts). Platjan (South Africa) is one such area. It comprise a matrix of agricultural practices and land-use types, dominated by humans. Consequently, it presented an ideal landscape to investigate how humans and carnivores coexist. Spatial capture-recapture modelling suggest stable populations manifested through low densities for leopards, spotted hyaenas, brown hyaenas, and Africa civet Civettictis civetta within the study area. Densities of the focal species were more similar to what has been found in more arid environments. Though it should be noted, that population fluctuations are common in nature, and this study only provide a brief snapshot of the population. Nonetheless, it provides baseline carnivore density estimates for the area. Single-season, single-species occupancy modelling was used to determine the influence of anthropogenic variables on species probability of site use. Results suggested that leopards and spotted hyaenas avoided crop fields (possibly due to higher human activity in these areas). Whereas black-backed jackal Canis mesomelas were positively influenced by the proportion of survey sites containing human infrastructure (possibly due to additional food sources provided by human presence). The covariates did not suggest any effect on brown hyaena and African civet probability of site use, which may be explained by temporal niche partitioning between the species and humans. Kernel density estimation and selectivity ratios revealed that all carnivores were predominantly crepuscular-nocturnal, with the exception of brown hyaenas which were strictly nocturnal. Among the focal species, brown hyaenas and African civets had the lowest temporal overlap with humans, which may explain why they weren’t affected by any of the anthropogenic variables. Whereas, jackal had the highest overlap, supporting a notion that they may be more tolerant of human presence than the other study animals. Overall, it seems that carnivores are able to coexist with humans on privately-owned farmlands through temporal niche partitioning, but manifest at rather low densities. Nonetheless, this study adds to the current understanding of human-carnivore coadaptation, and provides the first carnivore density estimates for the Platjan region.
- Full Text:
- Date Issued: 2020
The jackal as a mesopredator : dietary response to an apex predator and role as an endozoochore
- Authors: Favaretto, Bianca Sashika
- Date: 2020
- Subjects: Jackal buzzard
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48313 , vital:40841
- Description: Interactions between apex predators, mesopredators and their impacts on trophic dynamics have been well documented. However, the influence of apex predators, through the provision of carrion, on the foraging ecology of African mesopredators is poorly understood. To investigate such resource supplementation by apex predators for mesopredators, the black-backed jackal Canis mesomelas, a generalist mesopredator, was used as a model species to improve our understanding of this topic in South African ecosystems. To do this, I compared the diet of jackal at replicated sites with and without cheetah in the eastern Karoo, South Africa. Scat samples were macroscopically categorized into six broad dietary categories: mammal, reptile, bird, fruit, forage and insect. Mammalian prey was further identified to species and grouped into six functional dietary categories: carnivore, large ungulate, small ungulate, small mammal, and unknown mammal. Jackal diets were dominated by mammal prey, with significant differences in the biomass and frequency of occurrence of mammals by jackal at sites with cheetah and without cheetah. Mammal consumption, showed limited variation amongst seasons. Resource supplementation provided by predator derived carrion is an important factor influencing jackal foraging ecology. The emergent hypothesis that jackal may show demographic responses (increased fecundity, survival, density) to this supplementation needs to be tested. This study also provided an opportunity to investigate the potential role of jackal as an endozoochore. Jackal consume fruits and their seeds, yet to our knowledge, an investigation into their seed dispersing abilities is yet to be investigated. This study assessed the viability and germination capacity of ingested seeds extracted from jackal scat samples using the tetrazolium tests and germination trials. Seed viability and germination of all three species (Grewia occidentalis, Pappea capensis and Diospyros lycioides) were significantly lower than uningested seeds. These results suggest that jackal gut passage is acting severely on ingested seeds. This study represents a novel investigation into differences in jackal diet in sites with and without cheetah as well as the role jackal play in endozoochory, contributing to improved understanding of the ecological role of jackal.
- Full Text:
- Date Issued: 2020
The profile of local hunters in South Africa
- Authors: Du Plessis, Madelaine Patricia
- Date: 2020
- Subjects: Hunters -- Economic conditions -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48324 , vital:40847
- Description: The South African hunting industry, but more specifically local hunting, is regarded as one of the key sectors within South Africa’s wildlife industry – not only for the significant economic contribution it makes, but also from an equally vital conservation point of view. Despite this, local hunters are neglected in the sense that hunting accommodation and hunting packages provided by the majority of game ranches mainly focus on accommodating trophy hunters. This study investigated the profile of local hunters in South Africa. The objectives of this study were the following: establishing the factors which determine the profile of local hunters and then comparing the results to existing information, as well as identifying the economic contribution local hunters make towards South Africa’s economy. The study commenced with a literature review of existing research on the local hunting industry and on the profile of local hunters. Thereafter, a self-administered questionnaire was developed and conducted amongst active local hunters via the CHASA hunting confederation website, by means of which the primary data for the current study were collected. The study concluded that the profile of the South African local hunter has undergone slight changes from what previous research had established. This was attributed to several external as well as internal factors. The current research would assist hunting farms in approaching the local hunting sector with up-to-date information in order to accurately tailor their packages and marketing in line with the evidence presented in this dissertation regarding the changes in the profile of the South African local hunter.
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- Date Issued: 2020
The role of elephants in Hluhluwe-iMfolozi Park: Perceived versus measured effects on woody vegetation
- Authors: Mbongwa, Siphesihle
- Date: 2020
- Subjects: Woody plants -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48467 , vital:40879
- Description: Elephants were successfully reintroduced into the 900 km2 fenced Hluhluwe-iMfolozi Park (HiP) from 1981 onwards and their population has increased exponentially since. Their initial reintroduction was motivated by the need to control bush encroachment and to maintain ecosystems such as grassland and open woodland, and to restore ecological processes offered by elephants. The subject of the HiP elephant population and their impact on vegetation in the Park has become controversial; with some concerns being raised that the population is too high and is negatively affecting the vegetation. An absence of a vegetation monitoring programme in protected areas with elephants creates uncertainty leading to an ‗elephant impact‘ debate. This study aimed to compare the perceptions of stakeholders regarding the issue of elephant impact in HiP with measured elephant impact on the vegetation in the Park. The perceptions and concerns of stakeholders regarding the effects of elephants on vegetation in HiP were investigated using a questionnaire. Stakeholders reported that elephants and fire were the main factors shaping vegetation change in HiP over the past decade. Sclerocarya birrea, Senegalia burkei and Schotia brachypetala were reported as the most negatively affected species. Also reported that they are concerned about the effects of elephants on the number of tall trees in the park, tree mortality and elephant‘s effect on rare indigenous vegetation. Most interestingly, the results showed that the groups of stakeholders had different perceptions of the level of elephant impact on the vegetation in the park; except for researchers and tourists whose were not significantly different from each other. Managers had the most respondents that reported that the level of elephant impact is unacceptable, while most researchers and tourists reported that the level of elephant impact is at an acceptable level. Vegetation plots that had been surveyed in 1999, 2003 and 2007, were resurveyed in this study during 2017 to assess elephant impact on vegetation over time. Comparison between the years sampled showed that there was a decrease in the density of tall trees, while the density of trees in 0.5-2 and 2-4 m height classes increased over the same period. Elephants had a strong preference for utilizing tall trees (>4 m) and a strong avoidance for trees in the height range from 0.5-2m tall (Jacobs selection index 0.56 and -0.69, respectively). This trend was apparent for all sample periods. In addition, elephants also showed a strong preference for some rare species including S. brachypetala and Sideroxylon inerme. Between 1999 and 2017, the density of preferred species has decreased while the density of avoided species has increased. I conclude that elephants are having a noticeable impact on the vegetation at HiP by changing vegetation structure to a shrub dominated vegetation, and causing a shift in species composition towards avoided species. The findings of this study show that the perceptions of stakeholders on the effects of elephants and the level of elephant impact on vegetation match the results from measured elephant impact - vegetation survey. However, Thresholds of Potential Concern (TPCs) should be outlined in the elephant management plan and are required to determine whether the levels of elephant impact at HiP have exceeded an acceptable level or not. This study conforms to previous research that an uncontrolled elephant population can have substantial impacts in fenced reserves. This study shows the importance for long-term and continuous vegetation monitoring programme to obtain reliable data to determine trends in vegetation changes over time.
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- Date Issued: 2020
The spatiotemporal aspects of predation on the Cape gannet Morus capensis population at the Lambert’s Bay gannet colony, Western Cape, South Africa
- Authors: Schoeman, Zanri
- Date: 2020
- Subjects: Sea birds -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47656 , vital:40262
- Description: Seabirds are one of the most threatened groups of birds with 29% of seabird species at some risk of extinction. As a result of multiple human-induced threats, seabird species including the Cape gannet Morus capensis which is endemic to southern Africa population experience significant declines and is now classified as Endangered. The Cape gannet faces predation threats from a variety of different species. The current predators of concern at Lambert’s Bay gannet colony are both the Cape fur seal Arctocephalus pusillus pusillus and the Kelp gull Larus dominancus. The former predates on fledglings and the latter predates on eggs. In the 2005/06 breeding season the entire Cape gannet population deserted the Lambert’s Bay gannet colony due to predation by the Cape fur seal. Although the Cape gannets have subsequently recovered to approximately 8000 pairs, seal predation on Cape gannet fledglings continues, together with predation by Kelp gulls. This has caused concern over the impact of predation on this species at the Lambert’s Bay colony, particularly given the species’ conservation status, its small breeding range and its current population trend. CapeNature, the conservation agency involved at this colony has been monitoring and managing the predation on Cape gannets and are interested in evaluating the success of their efforts. Therefore the aim of this study was to determine the spatial and temporal aspects of predation on the Cape gannet population at Lambert’s Bay gannet colony. When examining the influence of fish availability on predation intensity, we found that in years with an increase in fish biomass there was a decrease in predation probability by Cape fur seals. This increase in fish biomass not only led to decreased predation on the fledglings it also led to increased breeding success of the Cape gannets. In determining the effect of predation within the Cape gannet breeding colony we found that the probability of predation by Kelp gulls decreased in years with increased adult gannet density. Indirectly, Cape gannet population growth should lead to a decrease in Kelp gull predation as a higher gannet density increases the risk of injury to the Kelp gulls. This suggests that if Cape gannet populations continue to decline, they may become increasingly vulnerable to Kelp gull predation which can result in a further population decline. In terms of past management actions, the selective culling of predatory Cape fur seals and Kelp gulls, was evaluated. It was found that in the years in which culling of Cape fur seals and Kelp gulls was implemented, a decrease in predation was observed. This indicated that culling reduced predation in the short-term. Predation is inevitable, but due to the Cape gannet’s conservation status we suggest that additional, long-term, and more sustainable methods to reduce predation should be explored. Our research emphasises the need for improving food availability to Cape gannets as food security is paramount to their long-term survival and population growth. Colony management in isolation from other management strategies, is not efficient for conserving a species. We therefore suggest that sound management of predation at the terrestrial habitats are required but that effective management of fisheries are also required for the successful conservation of the Cape gannet. Food security for Cape gannets could be improved by, for example, establishing some ways that we suggest improving the food security for Cape gannets would be to establish Marine Protected Areas (MPAs) with dynamic boundaries around Cape gannet colonies, and to have locate the MPAs close to breeding and foraging hotspots where these areas are closed to fishing thus reducing the competition between commercial fisheries and marine predators, such as the Cape gannet. Another way to improve food security for the gannets are to promote the efforts of focussing on developing and implementing an ecosystem approach to fisheries management in which fishing quotas account for the needs of marine predators. The findings of this study have not only aided the understanding of the dynamics of predation on the Cape gannets and highlighted the extent that predation takes place on them but can also guide future management decisions regarding predation on this endemic and endangered species.
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- Date Issued: 2020
Towards the synthesis of trimethoprim using continuous flow Chemistry
- Authors: Ngwenya, Sandiso
- Date: 2020
- Subjects: Trimethoprim
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47475 , vital:39994
- Description: The continuous flow synthesis of trimethoprim, an antibiotic, was investigated in this study from simple commercially available reagents, such as aniline and dimethylamine. The first step of the synthesis involves a highly exothermic Michael reaction, between acrylonitrile and dimethylamine; process intensification through miniaturization provides a safe and efficient method of synthesis through the use of microreactors. This is afforded by their large surface area-to-volume ratio; one of the many characteristics of continuous flow synthesis that allows for rapid heat dissipation allowing for exothermic reaction to be conducted safely at ambient or higher temperatures. This study was optimized on a Chemtrix Labtrix® Start unit using a Chemtrix reactor achieving a conversion of 99% in 12 sec residence time at 25oC. Subsequently the base catalyzed condensation of the intermediate with 3,4,5- trimethoxybenzaldehyde was investigated using Little Things Factory reactors (Channel diameter: 1.0mm). Maximum conversion (100%) was obtained at 80oC in 20 mins. Due to the poor cyclisation observed with this intermediate, according to literature findings, the 3-dimethylamino group was substituted for aniline. The optimisation for this acid catalysed substitution reaction was performed on a homemade PTFE tubing reactor (Diameter: 0.5mm) and it was found that at 120oC in 10 mins residence time a conversion of 97% was obtained. From the results obtained, an investigation into an integrated process for the condensation and substitution reaction was done using the Little Things Factory system (Channel Diameter: 1.0mm) coupled with a homemade PTFE coil reactor (Diameter: 0.5mm). This process, under optimum conditions of temperature 80oC and residence time of 30 mins, attained a conversion of 76%.
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- Date Issued: 2020
Understanding the relationship between mangrove composition, stand dynamics and resource use in the Ntafufu estuary, Eastern Cape, as basis for sustainable resource use
- Authors: Mvakade, Monica , Rajkaran, Anusha
- Date: 2020
- Subjects: Estuarine ecology -- South Africa -- Eastern Cape , Aquatic ecology , Marine sciences , Fresh water
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49215 , vital:41611
- Description: Traditionally, coastal communities along the Wild Coast in the Eastern Cape, used mangrove forests for their livelihoods and socio-economic needs. Mangroves along the Eastern Cape coast are threatened by both natural and human factors. The wood obtained from the mangroves by rural households was used as poles for house and fence construction, firewood, and traditional medicine. This is a threat to the status of several mangrove species in this and surrounding areas. The harvesting of mangrove trees will have a direct and indirect effect on the other biotic and abiotic components of the mangrove ecosystems. The Department of Agriculture, Forestry and Fisheries (DAFF) (currently the Department of Environment, Forestry and Fisheries, or DEFF), through the National Forest Act no 84 of 1998, was directly responsible for the wellbeing of the national forests in South Africa. This also includes the mangroves as a specific national forest type. Several estuaries with mangroves occur within state forests. The harvesting and clear-felling of trees for timber and land conversion and associated waste of harvested mangrove poles and laths causes the many changes in mangrove forests. The aim of this study was to develop a framework for sustainable management of the mangroves for the Mtambalala forest management unit. This was done in relation to the requirements of the current legislation, policy guidelines and business plan of the management authority. The aim was pursued through two specific objectives. The first objective was to understand the variation in the composition in different parts of the Ntafufu Estuary, and the population dynamics of the main mangrove species, as basis for the development of sustainable resource use practices. Plots along transects were used to measure seedling to adult ratios, population structure and abiotic characteristics. The second objective was to understand the community use and requirements of mangrove wood from the Ntafufu Estuary. A participatory approach was followed to collect demographic data from each community, the requirements of mangrove poles and behaviour of harvesters. This was used to set up a framework to guide the sustainable management of mangroves based on the current status and stand dynamics of the mangrove communities. There are three mangrove species found in the Ntafufu Estuary: Bruguiera gymnorhiza (black mangrove) regenerates under the mangrove canopy and forms layers of even-aged stands. Avicennia marina (white mangrove) does not regenerate under a mangrove canopy i.e. the seedlings establish outside the canopy. A few Rhizophora mucronata (red mangrove) trees exist in the lower intertidal zone and form multiple stems on stilt roots. The mangrove associate, Hibiscus tiliaceus (wild cotton tree- mangrove associate), forms dense clusters of scrambling stems. Some of the Avicennia individuals show signs of mangrove bleeding and one individual of Bruguiera showed indications of disease. Mngazana and Ntafufu Estuaries had the highest tree densities of 2594 and 1402 trees ha-1 respectively, typical of riverine mangrove forest. The seedling to adult ratio was high in this study: 12.8 for B. gymnorrhiza and 24.3 for A. marina. Abandoned cut stems and laths were found during the study. Bark harvested for traditional medicine and cattle feeding in mangroves was also prevalent and expected to reduce the health of the forest. Mangroves in the Ntafufu Estuary are expanding, and the population structure of the three mangrove species showed a healthy balance between young and mature stems. The harvesting of Black mangrove (B. gymnorrhiza) poles for mainly roof construction is relatively limited. As part of the functions of the DAFF, the use of the mangrove resources has to be balanced with the resource availability from the mangroves, and this should result in a healthy functioning mangrove forest. Development of a participatory forest management (PFM) plan for a forest estate and its forest management unit, require an understanding of the mangrove communities and their dynamics, and the current level of resource use associated with the mangroves. The study recommended that a Mangrove Pole Harvesters Group is needed to practice silviculture through guidance of relevant governmental personnel.
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- Date Issued: 2020
Underutilisation of information communication and technology in the building construction industry case study: Department of Public Works in the Amathole district in the Eastern Cape
- Authors: Camngca, Vuyokazi Precious
- Date: 2020
- Subjects: Construction industry -- Information technology , Construction industry -- Data processing Information technology Communication and technology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/50632 , vital:42280
- Description: This study investigated the causes and effects of the underutilisation of Information Communication Technology (ICT) in the building section of the Amathole Region. The construction industry’s daily processes demand both heavy usages of data and data communication between project participants to meet client requirements. This industry is characterised by inaccurate and untimely communications that often result in costly delays and extensions of the project timeframe. ICT is a potential solution to this problem. The objectives of the study are, therefore, to determine why the above, a technically skilled occupational government institution in the Eastern Cape, does not employ ICT efficiently and optimally during this time of the looming global fourth industrial revolution. The literature review detailed the causes of and impact level of ICT’s utilisation and its potential benefits. For data collection, the researcher held unstructured interviews with a Chief Quantity Surveyor, Chief Architect, Engineer, Building Inspectors, and a Quantity Surveyor who dealt directly with construction projects. The key findings revealed that a lack of understanding of existing and newly available ICT software and hardware technology existed amongst certain senior officials within the building technology. The previously alluded, combined with the fear of the inability to learn and apply such new technology, has led to a culture of resistance to change from these more senior officials to utilise applications such as AutoCAD. The above-mentioned resistance, has also triggered the prevention of access to and lack of ICT resources, training, and inadequate funding, thereby eventually resulting in the underutilisation of ICT within the whole building section. This change also adversely affects all officials, especially the junior officials who have graduated using the most recent ICT technology during their studies. The researcher deduced, from the above findings, that adequate change management and continuous development, combined with the allocation of proper resources, would be necessary for all staff members. It was also determined that investments had to be made in the ICT equipment through the provision of a sufficient budget in the building section at AR.
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- Date Issued: 2020
Upwelling on the Southeast Madagascan shelf: frequency, extent, and driving mechanisms
- Authors: Collins, Matthew
- Date: 2020
- Subjects: Upwelling (Oceanography) -- Madagascar , Oceanography -- Research -- Madagascar Marine biology -- Indian Ocean
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49060 , vital:41597
- Description: The southeast coast of Madagascar, namely the region surrounding the town of Fort Dauphin, is an area that regularly experiences upwelling events. Two unique high frequency data sets, UTR data, and wind data retrieved from a nearby airport, are the primary data sets used to investigate the nature of the upwelling, i.e. the area that experiences upwelling, how often it occurs, and its mechanisms. To complement the in-situ data, several different satellite data sources are used alongside the in-situ data to study this relatively remote region, i.e. SST, chlorophyll-a concentration, current, and wind data. The results refine upon previous literature on the topic. The upwelling covers an area of 1o latitude by 1.3o longitude, and occurs on average 14 times per annum. The mechanism driving the upwelling can be attributed to both wind and current, with wind the more dominant driver along the south coast, and current more dominant along the east coast. Separate to the main objective of the thesis is the importance of in-situ data when analysing small scale events such as upwelling events. While the in-situ wind data were found to be unreliable due to its location within a valley, the UTR data were of vital importance in identifying and studying the finer details of the upwelling events. The satellite SST data, by comparison, were lacking in their ability to investigate the upwelling events. The satellite derived wind data, however, did prove useful when analysing the wind as a driver of the upwelling.
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- Date Issued: 2020
Utility of construction automation and robotics in South Africa
- Authors: Mkunqwana, Khungelwa Sandisiwe
- Date: 2020
- Subjects: Construction industry -- Automation , Construction industry -- South Africa -- Automation Robotics -- South Africa Robotics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/46174 , vital:39511
- Description: The construction industry demands active construction organisation, efficient construction processes and innovative construction techniques to effectively compete under increasing market competition and technological advancements in the twenty first century. The problems associated with construction, such as poor quality and slow productivity, labour shortages, occupational health and safety, and inferior working conditions, have opened the possibility of more revolutionary solutions within the industry. One such solution espoused as having tremendous potential to improve construction productivity whilst alleviating the problems associated with construction is Construction Automation and Robotics. Automation and robotics technologies encompass a wide range of innovative technologies using technologically advanced machinery to improve the speed and efficiency of a given process. The aim of this study is to analyse the extent of utility of construction automation and robotics in the South African construction industry. The research adopted the quantitative methodology and online survey to collect data. A detailed quantitative (statistical) data analysis was performed, using web-based software “QuestionPro,” including data analysis for investigating possible relationships between variables. Through this study it has been established that one of the prospective solutions to the problems associated with construction is in the implementation and utility of innovative technologies in construction such as automation and robotics. Moreover, the research found that automation and robotics in South Africa is at an interesting point whereby organisations are taking strides in accepting and implementing the technologies. It is envisaged that the utility of construction automation and robotics would improve the industry in terms of productivity, health and safety and quality.
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- Date Issued: 2020
Waste management in the informal settlements of Msukaligwa Municipality
- Authors: Ngema, , Noxolo Nondumiso
- Date: 2020
- Subjects: Waste disposal in the ground -- South Africa -- Ermelo , Refuse and refuse disposal -- South Africa -- Ermelo Squatters -- South Africa -- Ermelo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/46827 , vital:39665
- Description: This study focused on waste management, and, sought to evaluate the level of awareness on environmental impact of littering in vulnerable communities in the informal settlements of Msukaligwa municipality, in particular at Ward 16 which is Nyibe newly named as New Ermelo. This study was, thus, concerned with how solid waste is managed within the informal settlements. The study arose with the concern that the environment is mostly affected when informal settlements are developed. If informal settlements are less aware of the damage caused by littering and improper waste disposal, the waste management plan of a local municipality becomes ineffective where local communities do not assume their responsibilities for ensuring healthy and safe living environments. A quantitative research design was applied in this study. Population for this research comprised of Msukaligwa Local Municipality, with a study sample drawn from Ward 16 Nyibe households, church leaders, local business owners, and ward councillor. A nonprobability sampling technique for selection of study participants was used, and this technique applied in both households and stakeholders. Data was collected through self-administered survey questionnaires that were statistically analysed, weaving in filed observations, where deemed necessary. The researcher discovered that Nyibe (New Ermelo) community’s level of awareness of the environmental impact of littering is impressively above average. Majority of households’ respondents identified all the negative environmental impact caused by littering in vulnerable communities and the impact is considered a major challenge within Nyibe. Necessary waste disposal infrastructures are not provided at Nyibe leading to people littering on any open land, burning, or throwing solid waste in their family pit.
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- Date Issued: 2020
Wind damage impacts on Eucalyptus species performance in South Africa
- Authors: Hechter, Heinrich
- Date: 2020
- Subjects: Commercial forests -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48368 , vital:40853
- Description: Commercial forestry plantations in South Africa play an important role in the economy of the country, contributing 1.2% towards the gross domestic product, as well as with job creation in rural communities. Currently plantation forests cover 1% (1.2 million hectares) of the South African land surface, of which ±75 000 hectares (±43 000 hectares to Eucalyptus species) are re-established each year. Different timber companies afforest areas with different species to satisfy specific management objectives, with the two main objectives being for either the production of saw-timber or pulpwood. Species of the Eucalyptus genera are preferred as they are fast growing and have desirable wood and pulping properties. However, their productive potential can be negatively impacted by numerous abiotic and biotic risk factors. Of the various risk factors that forest stands are exposed to, wind and wind-related tree damage has received very little attention, both nationally and internationally. Wind-related tree damage may result in wind-throw (uprooting or stem breakage), or trees that tilt (lean off vertical). Trees that are tilting can recover to an upright position, but are likely to retain some level of stem sinuosity or butt-sweep. Although strong winds increase the risk of tree damage, a number of other factors can also act to predispose trees to wind-related damage. These include choice of planting stock (genotype and type of plant stock), planting practices (including soil cultivation), site factors (wind exposure, rainfall, soil texture and soil fertility) or excessive weed competition. Most of the literature dealing with wind-related tree damage has focused on trees growing in natural forests, whereas trees in natural forests differ from forest grown plantation trees in terms of above- and below-ground morphological differences, as well as the stability factors of the trees. There is a need to not only understand the impacts of severe (catastrophic) wind events on mature trees, but also to test management strategies that prevent, or minimize damage prior to any severe wind events. Two existing eucalypt trials were used to provide information on the influence of selected re-establishment silvicultural practices on short-term pulpwood and long-term saw-timber survival, growth and uniformity when influenced by catastrophic wind events, within South Africa.
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- Date Issued: 2020
A clip composition case study of communal wool production in the Eastern Cape, South Africa
- Authors: Dreyer, Susanna Maria
- Date: 2019
- Subjects: Wool industry -- South Africa -- Eastern Cape , Wool -- South Africa -- Eastern Cape Sheep industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39480 , vital:35265
- Description: Previous studies conducted on wool production in the communal areas of the Eastern Cape have concluded future research should focus on whether the observed differences in average wool price received between shearing sheds are due to differences in clip preparation (i.e. classing) or differences in the quality of the wool being produced (i.e. genetics).The objective of this study was to establish whether there are indeed geographical differences in the average wool price received by communal wool producers in the Eastern Cape and, if so, whether this difference in earnings is attributable to differences in the quality of wool produced and/or clip preparation. The current research explored eight years of wool production records of communal wool farmers (2009/10 to 2016/17) obtained from BKB, the largest wool broker in South Africa. Statistical analyses included descriptive statistics, analysis of variance, parametric tests (i.e. t-test) and multiple regression analysis. The conclusions drawn from this study are: that there are indeed statistically significant differences in the average wool price received between the different geographic areas of the Eastern Cape communal regions, and that the primary determining factor is wool quality, while clip preparation also plays an important but secondary role. The study identified specific geographic areas where developmental interventions are most critical, with specific emphasis on improving the genetic composition of the wool sheep flocks. Specific strategies are recommended, namely:Removing inferior-quality rams and replacing them with superior-quality rams to prevent any inferior nondescript rams from breeding and producing progeny; Replacing the inferior-quality nondescript ewes in specific areas with superior-quality ewes, and Improving the survival rate of lambs and thereby contributing towards expediting the rate of genetic improvement of the communal wool sheep flocks.
- Full Text:
- Date Issued: 2019
A crowdsensing method for water resource monitoring in smart communities
- Authors: Banda, Clara Mloza
- Date: 2019
- Subjects: Data collection platforms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42449 , vital:36658
- Description: Crowdsensing aims to empower a large group of individuals to collect large amounts of data using their mobile devices, with the goal of sharing the collected data. Existing crowdsensing studies do not consider all the activities and methods of the crowdsensing process and the key success factors related to the process. Nor do they investigate the profile and behaviour of potential participants. The aim of this study was to design a crowdsensing method for water resource monitoring in smart communities. This study opted for an exploratory study using the Engaged Scholarship approach, which allows the study of complex real-world problems based on the different perspectives of key stakeholders. The proposed Crowdsensing Method considers the social, technical and programme design components. The study proposes a programme design for the Crowdsensing Methodwhich is crowdsensing ReferenceFrameworkthat includes Crowdsensing Processwith key success factors and guidelines that should be considered in each phase of the process. The method also uses the Theory of Planned Behaviour (TPB) to investigate citizens’intention to participate in crowdsensing for water resource monitoring and explores their attitudes, norms and perceived behavioural control on these intentions. Understanding the profiles of potential participants can assist with designing crowdsensing systems with appropriate incentive mechanisms to achieve adequate user participation and good service quality. A survey was conducted to validate the theoretical TB model in a real-world context. Regression and correlation analyses demonstrated that the attitudes, norms and perceived behavioural control can be used to predict participants’ intention to participate in crowdsensing for water resource monitoring. The survey results assisted with the development of an Incentive Mechanism as part of the Crowdsensing Method. This mechanism incorporates recruitment and incentive policies, as well as guidelines derived from the literature review and extant system analysis. The policies, called the OverSensepolicies, provide guidance for recruitment and rewarding of participants using the popular Stackelberg technique. The policies were evaluated using simulation experiments with a data set provided by the case study, the Nelson Mandela Bay Municipality. The results of the simulation experiments illustrated that the OverSenserecruitmentpolicycan reduce the computing resources required for the recruitment of participants and that the recruitment policy performs better than random or naïve recruitment policies. The proposed Crowdsensing Method was evaluated using an ecosystem of success factors for mobile-based interventions identified in the literature and the Crowdsensing Method adhered to a majority (90%) of the success factors. This study also contributes information systems design theory by proposing several sets of guidelines for crowdsensing projects and the development of crowdsensing systems. This study fulfils an identified need to study the applicability of crowdsensing for water resource monitoring and explores how a crowdsensing method can create a smart community.
- Full Text:
- Date Issued: 2019
A deep learning approach to classifying tyres using sidewall images
- Authors: Gifford, Dean
- Date: 2019
- Subjects: Image processing -- Digital techniques , Image processing Computer science
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39720 , vital:35351
- Description: End of Life Tyres (ELT's) pose a potential health and environmental risk when dumped in illegal stockpiles. For recycling to be considered feasible, a profitable business opportunity needs to be created. One method of making the recycling process of tyres more profitable is by understanding the compounds found within each tyre. This study aims at classifying these tyres in order to achieve this knowledge. A literature review was done to investigate neural networks, convolutional neural networks as well as existing deep learning architectures for image classification. A deep learning approach was applied in order to classify the logos of tyres as these approaches have proved their success in both image classification and more specifically logo classification. Although tyre classification has been implemented in the past, a deep learning approach has not been applied and the logo has not been the classifying element in any other studies. The main difference of this study compared to previous research surrounding deep learning and logo classification is the properties of the tyre logo. Logos on tyres are very similar in colour as they are purely formed in rubber and very seldom have any colour to them. Additionally, the embossed logos can contain variation among same branded tyres due to small inconsistencies in the moulds. The implementation of this deep learning solution saw multiple convolutional neural networks implemented. Some of these architectures were also implemented using transferred learning. The metrics obtained as outputs from training and testing the architectures were the accuracy, precision, recall, and F1-score. These metrics were compared in conjunction with the confusion matrix produced from testing. To ensure that variance was accounted for in the experiments, the k-fold cross-validation technique was adopted. The results of this study identified that one convolutional neural network model, MobileNet, was particularly well suited for the context of classifying logos on tyre sidewalls. The MobileNet architecture had the highest performance metrics for both training from scratch (96.7% accuracy) and transferred learning (98.8% accuracy). Three other models performed particularly well when trained from scratch, these were a modification of the LeNet architecture, ResNet50 and InceptionV3. The transferred learning results were also impressive with four out of the 5 models achieving an accuracy above 94%. Interestingly, the ResNet50 architecture failed to train when transferred learning was applied. Contrasting to this, the two models VGG16 and VGG19 failed to train when trained from scratch but performed equally as well as the other models when transferred learning was implemented. This indicates that although transferred learning can improve the performance of models, it is highly dependent on the task as well as the model. Overall the results obtained proved that a deep learning approach could be applied in order to classify tyres accurately.
- Full Text:
- Date Issued: 2019
A gatherer's paradise? Early humans and plant foraging on the cape south coast, South Africa
- Authors: Gummow, William Thomas
- Date: 2019
- Subjects: Soil amendments , Plants -- Nutrition Plant physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39687 , vital:35348
- Description: South Africa is a semi-arid country that is experiencing population growth and the associated pressure of producing sufficient crops to sustain the population. Furthermore, poor land management has also led to increased degradation of valuable arable land. To improve poor soil quality and possibly avoid or reverse degradation and ultimately desertification, it was suggested that soil amendments are a potential solution to some of these problems. Although soil amendment is a relatively well-known practice to improve soil quality, the use of rubber crumb as a soil amendment is not well studied. Rubber crumb is produced from end-of-life tyres that have been ground up to fine particles and as such can be used as a secondary resource to replace the use of virgin materials. Rubber crumb has been used in an array of industries, however, the present study investigated the possibility that rubber crumb might be used as a soil amendment to alleviate various forms of soil degradation, specifically soil compaction and crusting, and potentially improve crop establishment and growth.To determine this, a soil that is prone to crusting and compaction was amended with rubber crumb at rates of 5%, 15% and 25%. Various soil physical characteristics, such as bulk density, particle density, porosity, field capacity and penetration resistance were investigated and it was determined that as the percentage rubber crumb increases in the soil, so do the beneficial characteristics of the soil. Furthermore, the rubber crumb was also treated in various ways in order to determine how the treatments might affect the chemical properties of the soil, as well as the amount of zinc that is leached from the rubber crumb. It was found that washing the rubber with a weak acid or even water prior to adding it to the soil resulted in more desirable chemical condition compared to untreated rubber crumb. Lastly, maize (Zea mays L.) was used to determine whether amending soil with pre-treated rubber crumb in different percentages had an influence on the germination success and growth rate of maize. In terms of germination success, amending soil with rubber crumb does not seem to have a significant influence, however, growth rate decreased as the percentage rubber crumb increased, while treating the rubber with a weak acid or water prior to adding it to soil had the most positive effect on plant growth. It can therefore be concluded that rubber crumb amendment rates between 5% and 15% resulted in the most desirable soil physical properties and plant growth amongst the amendments. However the best plant growth was still seen in the control soil, to which no rubber crumb had been added.
- Full Text:
- Date Issued: 2019
A nutrition education tool for practical application of the food based dietary guidelines for primary school teachers in Nelson Mandela Bay
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Nutrition -- Education
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44616 , vital:38152
- Description: Background: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. Aim: The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. Research design and methodology: A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results: Of the 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Conclusion and recommendations: Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
A nutrition education tool for practical application of the food based dietary guidelines for primary school teachers in Nelson Mandela Bay
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Malnutrition -- South Africa -- Port Elizabeth , Nutrition—Evaluation Nutrition -- Evaluation Nutrition -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45019 , vital:38226
- Description: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results of the research 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
A Statistical assessment of available solar resource across multiple sites in South Africa
- Authors: Eastwood, Kirstie
- Date: 2019
- Subjects: Mathematical statistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39907 , vital:35505
- Description: Around the globe, fossil fuels remain the primary source of energy at around 78% of the world’s total energy consumption. However, the associated carbon emissions, environmental impact, the depletion of fossil fuels and price and cost volatility are factors influencing the growing popularity of research into renewable energy. Solar power is acknowledged as the fastest-growing renewable energy, but the uncertainty surrounding the long-term projections of solar irradiance available for energy conversion is a hindrance when discussing the financial risk with potential investors. This study investigates the quality of freely available solar resource data in South Africa as well as proposes techniques for potential solar farm site comparisons. Tolerance intervals derived within a Bayesian framework provide information on the future available solar resource across multiple sites. These techniques capture the inherent variability in the available solar resource which equips investors with statistical methods that lead to the better understanding of the solar resource and thus aids in better decision-making.
- Full Text:
- Date Issued: 2019
A suitability study for the implementation of a corporate geographic information system at the King Sabata Dalindyebo Municipality
- Authors: Triegaardt, Inge
- Date: 2019
- Subjects: Geographic information systems , Information storage and retrieval systems -- Geography Information technology Sustainable development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:37044
- Description: A tender in the Government Gazette in 2013 for the implementation of a Corporate Geographic Information System (CGIS) at the King Sabata Dalindeybo (KSD) Local Municipality, created an opportunity for a study to be conducted for the implementation of a Corporate Geographic Information System (CGIS). A CGIS is a suitable management system for implementation at a municipality, given that the municipality is ready. Internationally the implementation of CGIS at municipalities has been done successfully. In South Africa, however, the implementation of said software has been slow and at times unsuccessful. The purpose of this research study was to evaluate the current GIS knowledge and infrastructure of the KSD Local Municipality for the municipality to be a suitable candidate for the implementation of a CGIS. The evaluation was done by the collection of data through three questionnaires, two interviews and observations. The findings of this research study are discussed according to the qualitative data collected from the KSD Local Municipality and recommendations based on the results of the data collection have been made for the municipality to be implementation ready. The qualitative instruments such as pre-training, post-training/pre-implementation and postimplementation questionnaires, observations and interviews with the IT Technician and the CGIS Specialist were processed by the researcher to obtain insight to the perceptions of the employees and the current state of GIS in the KSD Local Municipality. The results from this research study were in-line with the benefits and barriers of implementation of a CGIS in municipalities in international literature.
- Full Text:
- Date Issued: 2019