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Masters Degrees (Environmental Science)

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    Assessing land degradation through land use/land cover change and socio-ecological analysis in the rural semiarid area of the greater Sekhukhune District Municipality, South Africa.
    (2022) Kgaphola, Motsoko Juniet.; Ramoelo, Abel.; Odindi, John Odhiambo.; Kahinda, Jean-Marc Mwenge.; Seethal, Ashwin.
    Abstract available in PDF.
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    Towards social learning in water related multi-stakeholder processes: investigating the value of information systems.
    (2021) Mhlongo, Thembeka Rachel.; Nel, Adrian.
    The challenge of behaving wisely concerning water constitutes itself as a wicked problem for humankind. This is particularly true for the management of the resource in South Africa. Wicked problems are termed such as they exist in social conditions of high complexity and uncertainty, amidst multiple perspectives where stakeholders are urgently attempting to solve the problems they see. Furthermore, wicked water-related problems become more challenging with climate change and uncertainty on the rise. All of the above holds for the uMngeni catchment in Kwazulu- Natal, South Africa, where environmental degradation and water stresses put additional pressure on the management of an increasingly scarce resource. In such contexts, a collective engagement approach by all stakeholders is essential for social learning and for fostering wise actions in complex dynamic stakeholder engagement spaces. Key studies indicate that information and knowledge co-generation within socio-scientific spaces is essential to feed the process of learning, and that this co-generation can be facilitated outside the typical physical space - in virtual hyperspaces of information systems. This study engaged with both the extent of social learning in the Umgeni catchment as well as the potential of ICTs to contribute to improve social learning in future. The aim of this research was thus to deepen understanding of the specific role of information systems, formed in virtual engagement spaces, for social learning. Practically, it also aimed to provide recommendations on the specific actions that can be taken to create a nourishing context for such social learning. The broad framework that underpinned this exploratory research and its methods was the social learning theory, while methodologically the qualitative data were gathered in line with Theory-Uan action research approach to knowledge creation and social learning. Using the researcher’s position as an embedded stakeholder, the study was grounded in the context of selected cases or multi-stakeholder groups in the upper uMngeni catchment. These cases are of three water-related multi-stakeholder groups in the uMngeni catchment. Participatory observation (PO) and action research (AR) were utilised, which involved the researcher in bio-monitoring and other water-related fieldwork projects with multi-stakeholder groups, meetings and partnerships in the catchment. Lastly, two selected emerging integrated information management systems - Mathuba web-based WIKI and the MIKE INFO desktop-based water management information system – were explored. Using the pre-conditions of social learning as an analytical framework of the results it was found that the degree of social learning was highest in the small community, local level of stakeholder engagement. Social learning registered the least in the larger catchment size scale of stakeholder engagement as well as at an intermediate level in the sub-catchment scale of multi-stakeholder engagement. Key themes identified across the scales of engagement included: high stakeholder empowerment by self-identity change and stakeholder education; a lack of continuous participation and barriers to knowledge sharing hindering social learning; and a lack of participation and implementation of relevant actors for all the groups. It was also found that these barriers and prohibiting factors to social learning can be overcome through the use of integrated information systems that variously promote transparency of information, virtual inclusiveness in engagement of actors at the local scale and the enhancing of trust and relationships using virtual platform features such as online placed GIS-based maps, documentation and forums. Challenges of employing such information systems were concluded to be complexity, costs and the lack of suitable facilitators of the software and virtual engagement of actors. Of the two explored information systems: The Mathuba WIKI site seemed most plausible, yet this ideal kind of supporting information systems, may risk being too complicated and its use may not be sustainable in the future. It was thus concluded that in order for such information systems to be included in support of multi-stakeholder engagement in the future, they must be integrated, inclusive, cocreated and truly transparent and should make good use of visual representations of water problem realities through maps, graphs and images that tell stories. Such information should also be piloted at the 3 main case study scales; the UEIP (large catchment management group), MCMF (subcatchment management group) and LCPG (local community groups). This can be evaluated and the results published for future applications on the national scale.
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    Multitemporal analysis of tropical cyclone impacts on the iSimangaliso Wetland Park sea turtle nesting beach using geospatial technologies.
    (2022) Radebe, Samkelo.; Njoya, Ngetar Silas.
    Increase in the intensity and frequency of tropical cyclones due to changing climatic conditions, poses a threat to sea turtle nesting beaches. In general, tropical cyclones increase the rate of coastal erosion along sandy beaches, potentially disrupting Sea turtle nesting when tropical cyclone seasons coincide with Sea turtle nesting seasons. The iSimangaliso Wetland Park Sea turtle nesting beach is situated along the coast in north-eastern KwaZulu-Natal, South Africa. Its unique location adjacent to the southwest Indian Ocean means that it experiences seasonal flooding due to tropical cyclones. Nevertheless, the impact of these tropical cyclones on the iSimangaliso Wetland Park sea turtle nesting beach remains uncertain. There is, therefore, a need to examine the intensity and frequency of tropical cyclones in this Ocean basin in order to understand their potential impact on the adjacent sea turtle nesting beaches. In this study, tropical cyclone Track Archive data was downloaded from the National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Centre for the years 1980 to 2020. Space-time pattern mining tools were then used to analyse the tropical cyclone data in ArcGIS 10.6. Medium resolution multi-spectral Landsat 7 and 8 satellite images were also collected from the USGS and were used in the Digital Shoreline Analysis System to calculate tropical cyclone induced changes in the position of the shoreline along the iSimangaliso Wetland Park sea turtle nesting beach. The results indicate that: (1) the intensity of tropical cyclones within 1000 km off the coast of the iSimangaliso Wetland Park sea turtle nesting beach have increased by 13.80% from 1980 to 2020. (2) Between the year 1980 and 2020 the frequency of tropical cyclones exhibited a spatiotemporal trend that is not statistically significant (z = 0.56 and p = 0.58 (>.05), suggesting that there is no noticeable increase or decrease in the frequency of tropical cyclones within 1000 km off the coast of the iSimangaliso Wetland Park sea turtle nesting beach despite rising sea surface temperatures. (3) The iSimangaliso Wetland Park sea turtle nesting beach is situated along an oscillating tropical cyclone Cold Spot, suggesting that tropical cyclones rarely reach the study area and generally dissipate further north towards southern Mozambique. (4) From 1999 to 2020, the iSimangaliso Wetland Park sea turtle nesting beach has experienced an average seaward shoreline movement by 68.73 m, averaging 0.76 m/year despite the increase in the intensity of tropical cyclones. (5) The results of this study suggest that the frequency of tropical cyclones have a significantly negative relationship (p < 0.01; r2 = -0.69) with the rate of shoreline movement along the iSimangaliso Wetland Park sea turtle nesting beach. (6) The intensity of tropical cyclone has a moderate correlation (p < 0.076, r2 = 0.39) with the rate of shoreline change along the iSimangaliso Wetland Park sea turtle nesting beach. (7) Distance of tropical cyclones to the study area has a very low negative relationship with the rate of shoreline change (p < 0.2, r2 = -0.2). Generally, these results suggest that unlike other sea turtle nesting beaches, the iSimangaliso Wetland Park sea turtle nesting beach is relatively safe from tropical cyclones activity despite the rapid increase in sea surface temperatures. The impact of tropical cyclones on the study area is attenuated by the presence of steep dunes, coastal vegetation, mangroves, and flood induced sediment deposition from the Mfolozi River and the St. Lucia estuary. A limitation to this study was inaccessibility to high spatial resolution satellite images due to cost. As a result, Landsat images with a medium spatial resolution of 30 m were used as these are freely available. Future research should consider the use of higher resolution satellite or drone and lidar images to study shoreline changes in relation to tropical cyclone activity and possible sea-level rise along the iSimangaliso Wetland Park sea turtle nesting beach.
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    The utility of very-high resolution unmanned aerial vehicles (UAV) imagery in monitoring the spatial and temporal variations in leaf moisture content of smallholder maize farming systems.
    (2021) Ndlovu, Helen Snethemba.; Odindi, John Odhiambo.; Sibanda, Mbulisi.; Mutanga, Onisimo.
    Maize moisture stress, resulting from rainfall variability, is a primary challenge in the production of rain-fed maize farming, especially in water-scarce regions such as southern Africa. Quantifying maize moisture variations throughout the growing season can support agricultural decision-making and prompt the rapid and robust detection of smallholder maize moisture stress. Unmanned Aerial Vehicles (UAVs), equipped with light-weight multispectral sensors, provide spatially explicit near real-time information for determining maize moisture content at farm scale. Therefore, this study evaluated the utility of UAV derived multispectral imagery in estimating maize leaf moisture content indicators on smallholder farming systems throughout the maize growing season. The first objective of the study was to conduct a comparative analysis in order to evaluate the performance of five regression techniques (support vector regression, random forest regression, decision trees regression, artificial neural network regression and the partial least squares regression) in predicting maize water content indicators (i.e. equivalent water thickness (EWT), fuel moisture content (FMC) and specific leaf area (SLA)), and determine the most suitable indicator of smallholder maize water content variability based on multispectral UAV data. The results illustrated that both NIR and red-edge derived spectral variables were critical in characterising maize moisture indicators on smallholder farms. Furthermore, the best models for estimating EWT, FMC and SLA were derived from the random forest regression algorithm with a relative root mean square error (rRMSE) of 3.13%, 1% and 3.48 %, respectively. Additionally, EWT and FMC yielded the highest predictive performance of maize leaf moisture and demonstrated the best correlation with remotely sensed data. The study’s second objective was to evaluate the utility of UAVderived multispectral imagery in estimating the temporal variability of smallholder maize moisture content across the maize growing season using the optimal maize moisture indicators. The findings illustrated that the NIR and red-edge wavelengths were influential in characterising maize moisture variability with the best models for estimating maize EWT and FMC resulting in a rRMSE of 2.27 % and 1%, respectively. Furthermore, the early reproductive stage was the most optimal for accurately estimating maize EWT and FMC using UAVproximal remote sensing. The findings of this study demonstrate the prospects of UAV- derived multispectral data for deriving insightful information on maize moisture availability and overall health conditions. This study serves as fundamental step towards the creation of an early maize moisture stress detection and warning systems, and contributes towards climate change adaptation and resilience of smallholder maize farming.
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    A study investigating impacts of sea level rise on coastal ecosystem services along the eThekwini Municipality coastline as a consequence of climate change and recommendations to build/enhance resilience.
    (2022) Petersen, Carla Bianca.; Pillay, Srinivasan Seeni.; Mather, Andrew Alan.; O’Donoghue, Sean.
    Climate change during the 21st century is caused by the rapid increase in global warming because of human activity. The consequences of climate change include melting glaciers, rising sea levels, and extreme weather. The primary cause of global sea level rise (SLR) is melting of ice on land, followed by ocean thermal expansion. Extreme events are happening more often and are becoming more intense due to greenhouse gas emissions from human activities. Coastal ecosystems are exposed to SLR and its physical impacts, such as flooding or salinisation, which in turn increase ecosystems’ vulnerability and decrease their ability to support livelihoods and provide ecosystem services such as coastal protection. Coastal ecosystems are also highly vulnerable to human-mediated drivers of climate change, such as land use change and coastal squeeze, because they are situated in the sea-land interface area that is favourable for urbanisation and development. This study focuses on the impacts of SLR on coastal dunes, and a protected tree species, Mimusops caffra, commonly known as coastal red milkwood, naturally occurring in part of the coastal forest in eThekwini Municipality. It further provides recommendations to enhance resilience along the Durban coastline. The results from the Coastal Vulnerability Index (CVI) analysis, classification of land use, developments impacted by a 300mm analysis, and the risk assessment of coastal ecosystems conclude that future SLR impacts will pose a threat to land demarcated under the Durban Metropolitan Open Space System, National Freshwater Ecosystem Priority Areas, and protected areas, as well as affluent high costing properties and coastal dunes and forests respectively, by a 300mm SLR along the eThekwini coastline in the next ±111 years if the current rate of SLR for Durban (2.74 mm/yr) remains constant. Further, whilst prior research suggests that the dieback of Mimusops caffra (M. caffra) is strongly related to fungal infections, results from this study indicate that M. caffra growing closest to the sea are stressed by environmental factors either wind or surge, thus increasing fungal infection as well. There is, however, little research on the impact of salt spray on these trees. Hence it is recommended that further investigation is required on milkwood to better understand the dieback observed in this study (i.e., due to fungus, or natural cause), especially as they are a protected species. Adaptation measures must be considered in areas identified as “high” risk for the protection of development from future SLR impacts, as well as maintaining natural areas where biophysical functionality is unhindered. From the CVI analysis, the regions which contain developments (i.e., private property) within the 100m HWM, both local government and homeowners should consider working together when installing geofabric sandbags to avoid increasing the effects of coastal erosion, as risks can be relocated elsewhere along the EM coast if individual action is not coordinated. From the classification of land use assessment, all areas within the respective land use that fall within the high-risk zone, the EM setback lines in conjunction with ecosystem-based adaptation should be implemented in order to protect these areas and ensure the functions of each land use is not unhindered. From the analysis of developments potentially impacted by future SLR, the total amount of estimated value of property loss within the given suburbs can assist coastal managers with deciding how money should be spent on defending properties and will yield the most protection from future SLR impacts along the EM coastline (i.e., a cost-analysis approach). Lastly, from the risk assessment of coastal ecosystems, future research on applying the vegetation index to certain parts of the EM coastline is necessary to get a better understanding of how vulnerable coastal ecosystems are to SLR impacts in Durban.
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    An assessment of the heavy metal concentrations in the water and sediment of the uMgeni estuary, using visible and near-infrared reflectance spectroscopy.
    (2021) Ramcharan, Suvasha.; Gebreslasie, Michael Teweldemedhin.
    Abstract available in PDF.
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    An investigation into implementing net zero carbon new buildings: a case of the eThekwini Municipality, Kwazulu-Natal, South Africa.
    (2021) Elias, Naseema Ahmed.; Thambiran, Tirusha.
    Better design practices, energy efficiency, and green building materials will enable the building sector to unlock emissions savings into the future, because what is constructed today will be the future of our buildings and its associated emissions.¹ Buildings are integral to the growth of our economy and provides a scaled opportunity to influence our environment and health positively. Buildings have relatively long lifespans and contribute significantly to energy consumption and greenhouse gas (GHG) emissions. It is vital that the development of sustainable buildings is encouraged. The role of the building sector toward reducing GHG emissions is now better understood, resulting in various initiatives globally, to move toward being a net-zero carbon sector. While low-carbon buildings are gaining momentum in the realm of sustainable development, this study provides decision-makers with quantifiable information on the cost of reducing GHGs to aid in their prioritisation of climate actions. The eThekwini Municipality (Durban) in South Africa has a long history of developing early climate change interventions and is therefore selected as a case study. This study analyses high emitting sectors within the eThekwini Municipality to verify global findings that the building sector is indeed the sector to offer high abatement potential at the lowest cost, and then offers an evidence-based pathway of implementation of climate actions. Specifically, as the city has committed to a zero-carbon building sector, this study presents the associated cost implications of such a commitment through the approach of determining Marginal Abatement Cost Curves (MACC) using the Climate Action Plan mitigation potential assessment for the municipality. Technical interventions to reduce GHG emissions within the MACC employed a bottom-up approach for each sector and are based on the availability and feasibility of the interventions with some engagement being conducted with Municipal stakeholders and from industry experts. The MACC presents timeframes of 2030, 2040, 2050 across key sectors and highlights that the building sector offers significant GHG reductions at the lowest cost when compared to other high emitting sectors in the eThekwini Municipality. Further to this, this study deep-dives into the most financially feasible sub-sectors within the building sector using a tool specifically developed for this study, namely, the Net-Zero Carbon Energy Efficiency Cost Model. This model explores sub-sectors within the building sector to narrow down the selection of climate change mitigation projects within the building sector. The cost model accounts for differences in lifecycle costs for buildings with enhanced energy efficiency and buildings with standard energy efficiency requirements contained within existing building regulations. It is established that shopping centres and school blocks should be prioritised within the building sector for emissions reductions. These findings should serve as a tool to assist decision-makers in prioritising climate actions that will provide a high abatement potential at the least cost. While this study focuses on the bottom-line economics of climate mitigation interventions, it is important that a more holistic cost-benefit analysis be undertaken, to consider broader opportunity costs, risk mitigation, and savings that is associated with reducing GHGs.
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    Remote sensing drought variability across different selected biomes of South Africa.
    (2022) Diza, Duduzile.; Mutanga, Onisimo.; Sibanda, Mbulisi.
    Abstract available in PDF.
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    Study on sulphur dioxide (SO₂) and particulate matter 10 (PM₁₀) variations in the City of Tshwane, Gauteng.
    (2021) Matyeni, Ayanda.; Venkataraman, Sivakumar.
    Air pollution is a global concern caused by road and air traffic, the rapid growth of the industrial sector, and urban development. About 3.7 million people annually die prematurely, globally caused by air pollution. Air pollution also destroys the crops that would have been enough to feed millions of people. The World Health Organization (WHO) recently reported an alarming 80% of urban area dwellers in selected areas breathing air laden with pollutant levels above the set standards (WHO, 2016). South Africa established a database of regions that tracks air pollution levels. As of 2013, there were reports that the greater Johannesburg / Gauteng region had the most polluted air in the country. In 2016, the Hartbeespoort area was added to the database, due to it’s highly polluted air because of its proximity to major industrial areas. Air quality in the City of Tshwane, situated in Gauteng Province, is also influenced by its location as it is close to the industrial areas of Johannesburg. Globally, the city was the 162nd most air-polluted area, with a particulate matter concentration of 60 mg/m3. Mining operations and other industries, vehicle emissions, domestic fuel burning, and veld fires are among the sources of poor air quality in the Gauteng province. Gauteng is also one of the most densely populated areas, with heavy traffic and informal settlements using coal or other fuel fires also adding to the air pollution. This research aimed to examine the significant air pollutants in Tshwane, Gauteng, and the resulting air quality. Pollutants of concern in this study were sulphur dioxide (SO2) and particulate matter (PM10). The study focused on temporal variations of the concentrations of the major pollutants at the continuous air quality monitoring stations. Furthermore, the focus was on how the concentrations of the pollutants influence the quality of the environment and human health. Sampling took place at various areas in the City of Tshwane, and the results were compared to the WHO standards for air quality. It was found that solutions to the air pollution problems exist, including better and simpler methods for starting coal fires, broader electrification, cleaner stoves and chimneys, increased ventilation, and the use of low-smoke fuels, less production of carbon dioxide, and overall improvements in technology.
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    A systematic review and meta-analysis of solar technology impacts on rural households: experiences from the Global South.
    (2021) Kanniah, Deanntha.; Munien, Suveshnee.
    Renewable energy technologies are widely prescribed to address multiple developmental needs, especially in developing contexts. As reflected in the growing body of literature, these devices and energy sources can generate socio-economic and environmental benefits and offer relatively rapid transitions to more sustainable practices. In this regard, it is essential to understand and identify the links among their impacts at a household and community level. This study aimed to critically examine how the impacts of solar technologies have been examined and measured at the household level, focusing on low-income and rural communities across the Global South. This review systematically focuses on research within a specified temporal range, 1999 to 2019, concerning the UNDG’s definition of impact and the sustainable livelihood’s theoretical framework. The motivation for this review is to establish whether research of the developing contexts have been able to respond to the multi-dimensionality of energy access and determine whether research has been a reflection of the changing energy narratives on energy needs. In addition, this review examines how and whether the impacts of solar energy technologies (SETs) are examined in relation to specific livelihood outcomes. Following the PRISMA 2009 and 2020 guideline for systematic reviews, the Web of Science, Google Scholar, and WorldCat databases were used. The initial search yielded (n=175187), which was later reduced to a total of n=56 cases that met the geographic, temporal, and contentrelated criteria. It was found that over the temporal range, Global South countries contributed a significantly lower number of published research compared to the global north countries. Over time, progressive trends in the proportion, dissemination and development of different SET’s could be identified as literature was found to have investigated several types of SETs across 24 different Global South countries using eight different analyses dominated by mixedmethod approaches and field survey methods. The meta-analysis revealed that despite the diversity in indicators, no studies reported against all capital bases of rural livelihoods. In addition, the classification identified that there were more qualitative and indirect measures of SET impact at the household level. Despite financial indicators appearing in all the reviewed studies, the diversity and inclusivity of the indicators used were reflected in the increasing proportion with which other livelihood impacts were recorded over the temporal range. From the analysis of mean impacts, the overall impression given is that SET’s have a positive impact on the livelihoods rural households in developing countries. However, the proportion of studies using each indicator is insufficient for these impacts to be definitive due to the variation. The review concludes that the impacts of solar technologies at the household level in developing contexts are not specific to livelihoods benefits in how they are reported. This makes it difficult to assess the overall successes of RET- transfer in the domestic sector. A recommendation based on this review is to use mixed method approaches, more diverse indicators and the SLA and UNDG’s definition of impact. This would ensure that future impact analyses are a true reflection of all possible impacts of SET’s on rural households and the selection of the most appropriate SET’s to be installed in rural households. There should be significant efforts to bring together academia, industry, and government to facilitate and encourage further research and expand SET’s across more developing countries to promote development and innovation within the industry. Lastly, to ensure that SET’s have a sustainable impact on rural households the operation and maintenance of SET’s needs to increase.
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    Efficacy of morphological approach in the classification of urban land covers.
    (2020) Tsoeleng, Lesiba Thomas.; Odindi, John Odhiambo.; Mhangara, Paidamwoyo.
    Understanding the often-heterogeneous land use land cover (LULC) in urban areas is critical for among others environmental monitoring, spatial planning and enforcement. Recently, several earth observation satellites have been developed with enhanced spatial resolution that provide for precise and detailed representation of image objects. This has generated new demand for enhanced processing capabilities. Thus, the need for techniques that incorporate spatial and spectral information in the analysis of urban LULC has drawn increasing attention. Enhanced spatial resolution comes with challenges for most pixel based classifiers. This include salt and pepper effects that arise from incapability of pixel based techniques in considering spatial or contextual information related to the pixel of interest during image analysis. These challenges have often contributed to the inaccuracy of heterogeneous LULC classification. Object based techniques on the other hand have been proposed to provide effective framework for incorporating spatial information in their analysis. However, challenges such as over/under segmentation and difficulty or non-robust statistical estimation hamper most object techniques in achieving optimum performance. Thus, to achieve optimum LULC classification, the full exploitation of both spectral-spatial information is essential. Hence, this study investigated the efficacy of Mathematical Morphological (MM) techniques referred to as morphological profiles (MP) in LULC classification of a heterogeneous urban landscape. The first objective of the study evaluated two MP techniques i.e. concatenation of morphological profiles (CMP) and multi-morphological profiles (MMP) in the classification of a heterogeneous urban LULC. Findings from this study indicated that both CMP and MMP provided higher accuracies in classifying a heterogeneous urban landscape. However, in evaluating their capability in preserving geometrical characteristics such as shape, theme, edge and positional similarity of image structures, CMP provided higher accuracies than MMP. This was attributed to the use of Principal Component Analysis (PCA) in the construction of MMP that resulted in the distorted edges of some of the image objects. However, in comparing the techniques in terms of the capability to discriminate image objects, MMP provided higher classification accuracies compared to CMP. This can be attributed to the former’s capability to exploit both spectral and spatial information from very high spatial resolution imagery. Hence in the second objective, MMP was adopted due to its ability to deal with dimensionality problem associated with CMP and its superior object discrimination capability. The findings indicated that MMP significantly enhanced ML and SVM classification accuracies. Specifically, the use of MMP as a feature vector for SVM and ML classification increased LULC distinction of objects with similar spectral signatures in a heterogeneous urban landscape. This is due to its capability to provide an effective framework for synthesis of spectral and spatial information. Overall the study demonstrated that morphological techniques provides robust novel image analysis techniques which can effectively be used for operational classification of a heterogeneous urban LULC.
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    Implications of land use practices and socio-hydrological vulnerability within a rapidly developing city: a case study of the Umhlatuzana River, Ethekwini, South Africa.
    (2020) Webster, Candice Natasha.; Munien, Suveshnee.; Naidoo, Sershen.
    Anthropogenic actions affect land uses and land use change concomitantly influencing water quality in a catchment. In a catchment varying levels of income and access to infrastructure and resources result in a lack of access to reliable and clean water, forcing households to rely on nearby water sources such as rivers, dams or lakes to meet their basic needs. Utilisation of river water is influenced by the perception of water quality. The main aim of this study is to explore how land use practices and human-water interactions influence socio-hydrological vulnerability within the Umhlatuzana catchment in a rapidly developing city. Previous research has not focused on the water quality and vulnerability of households within South African catchments. Land use activities and land use changes were observed between 2003 and 2014 to examine the pressures on water and water quality in the catchment. Furthermore, selected water quality parameters were analysed for an 11-year period between 2004 and 2014 in order to examine temporal and spatial variation to unpack influences on vulnerability in the catchment. Moreover, 350 household surveys were administered in order to describe the community perception of land use, land use change and water quality in the catchment. Finally, field observations of areas surrounding the water sampling sites were completed to inform results, and provide a more nuanced understanding of data trends, community perceptions, and experiences with the river. Analysis of the spatial data indicates changes in the catchment that may contribute to the deteriorating water quality in the river. Furthermore, reports of malfunctioning Waste Water Treatment Works (WWTW) link the sewage system to increasing E. coli and T. coli levels in the river, which threatens the health and well-being of all river users. The households in the community are diverse with varying levels of vulnerability and access to resources as many households identified government grants as a source of income. Additionally, although most households perceived the river water in the catchment to be poor and deteriorating, of those that utilised the river water, majority did not treat it before use. The study demonstrates that there are households within the catchment that are vulnerable and at risk to the deteriorating river water in the catchment. Further research is required to identify sources of pollution to improve the water of the Umhlatuzana River and reduce risks to the community in the catchment.
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    An assessment of visitor profiles, consumption patterns and perceptions as well as the state of coastal and marine tourism (specifically beach) sites in KwaZulu-Natal Province, South Africa.
    (2021) Gounden, Dinolen.; Bob, Urmilla.; Munien, Suveshnee.
    Coastal and Marine Tourism (CMT) is the main sub-sector of tourism and has substantial socio-economic and environmental importance. Specifically, CMT is a key economic contributor as well as creating opportunities for social recreational and leisure experiences and promoting conservation and environmental awareness concerning coastal and marine natural resources. However, there are increasing demands on CMT locations that include increases in visitor numbers, residential and business/ industrial demand, natural resource extraction activities, and conservation imperatives. Understanding and balancing these demands are central to sustainable CMT in South Africa. KwaZulu-Natal (with its mild climate and more than 600 km coastline with diverse coastal and marine resources and activities) is South Africa’s key CMT destination. There is limited research that undertakes provincial level analyses that focus on demands and impacts. In this context, this study adopts the drivers, pressures, state, impact and response (DPSIR) framework to examine visitor profiles, consumption of coastal and marine activities, and perceptions of CMT locations in 41 selected beaches along KwaZulu-Natal's coastline. One thousand two hundred (1 200) visitor surveys were conducted at selected beach locations in KwaZulu-Natal using the spatially-based, systematic sampling approach. Additionally, the state of the beaches were assessed using an on-site observation checklist. Forty one beaches were purposively chosen for the on-site observations during off-peak and peak periods to consider seasonality. The use of mixed methods is a methodological contribution since there is limited research that integrates both visit surveys and observation assessments at CMT locations. The results indicate that diverse visitors in relation to socio-economic and spatial characteristics visit CMT locations. The main activities that visitors participate in are coastal recreational and leisure activities, with lower participation rates in relation to marine activities. The economic value of CMT emerges with most respondents being overnight visitors and day-trippers compared to local residents. Of importance is that KwaZulu-Natal is the main source market for CMT followed by Gauteng, the main domestic tourism market in the country. Repeat visitation was noted together with generally high levels of satisfaction with beach experiences and locations. The main visitor spend was on food and drinks, and transportation; with accommodation spend also being important in relation to overnight visitors. In relation to the on-site observations, the substantial increase in the numbers of visitors during peak compared to off-peak periods was evident. Of concern was that although signage indicated that there is awareness of aspects that need to be considered to restrict or limit usage at CMT locations, compliance of rules and regulations was almost non-existent, which is a serious concern. Thus, a key recommendation is that the management of CMT beach locations, especially during peak seasons when the number of visitors and consumption increases substantially, needs to be addressed. Training of security personnel to assist with raising awareness and enforcement is particularly important. Improving infrastructure and services (such as better waste management) is also recommended. This study indicates that the demands on CMT beach locations, which are popular destinations, need to be better managed to ensure socio-economic and environmental sustainability.
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    Regional representativeness hotspots for world's tetrapod vertebrate genera.
    (2021) Govender, Chanelle Ornella.; Proches, Serban Mihai.
    As anthropogenic stress and resulting habitat degradation put pressure on biodiversity, there is a need for urgent and innovative conservation strategies. The integration of the biogeographical concept of bioregionalisation into conservation planning is critical for the successful protection of biodiversity on a global scale. This study looked at zoogeographic regions taken one by one, and combined based on their evolutionary histories, climate, and overall spatial interactions. Representative genera were selected, and their richness calculated for these single and combined regions. Representative genera for a region include genera which exhibit high levels of endemism and regional filling of that region. Regional representativeness hotspots were combined to produce a global hotspot scheme. Combinations of regions such as the Neo-Caribbean, Holarctic and Neotropic-Nearctic included significant numbers of ecoregions with hotspot status. Combinations including the Australian Zoogeographic Region and gradually larger numbers of neighbouring regions resulted in varying spatial hotspot patterns relevant to global regionalisation attempts. Theories and hypotheses, including continental drift, vicariance and dispersal events, and the influence of paleoclimates all contribute important explanations towards shaping the distribution of genera and the delineation of zoogeographic regions. Regional representativeness hotspots can be biogeographical units for robust conservation strategies, representing a proactive approach to the conservation of representative genera and co-occurring taxa worldwide.
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    A multi-criteria approach to decision making concerning environmental planning issues within decentralised government institutions.
    (2000) Huntley, Renaire Shelly.; Archer, D.; Petkov, Doncho.
    Abstract available in PDF.
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    The integration of biodiversity in local land-use planning: Gert Sibande District Municipality, South Africa.
    (2020) Makhuvha, Khumbelo.; Rouget, Mathieu Jean Francois.; Lötter, Mervyn Charles.
    Twenty-five years after the Convention on Biological Diversity (CBD), much emphasis has been placed on the integration of biodiversity priorities and concerns into the development sectors. South Africa has made substantial progress in this regard. The understanding of threats to biodiversity, ecosystem services, sustainable development, and the link between ecosystem services and human well-being, in high levels of government, were fundamental factors in mainstreaming biodiversity in South Africa. The change in government and democratisation in 1994 has also facilitated the positive outcomes for integrating biodiversity into development. It has become a mandate for local government to address the socio-economic development needs of communities. Within the local land-use planning arena, the Integrated Development Plan (IDP) has been used as a comprehensive tool for guiding local development objectives. However, the promulgation of the Spatial Planning and Land Use Management Act (Act 16 of 2013) has elevated the status of the Spatial Development Framework (SDF) to guide other municipal plans. It has been suggested that integrating biodiversity priorities and conservation plans into comprehensive planning tools, such as the SDF, yields greater opportunity for biodiversity conservation to be prioritised in development planning and implementation. In contrast, the consideration of biodiversity priorities and conservation plans by local land-use planners during reactive post-hoc decision-making processes yields the least potential for biodiversity conservation. The main objective of this study was to assess the ability of local government to incorporate the principles of biodiversity conservation plans into their SDFs, and the implementation of these plans during their daily land use planning processes. I assess both suggestions in chapter 2 and chapter 3 of this thesis respectively. In chapter 2, I assess the review schedules, and the text making up the SDFs, and the integration of conservation plans into the Gert Sibande local municipalities SDFs, using geographic information systems (GIS) techniques. Biodiversity priorities were considered in the SDFs, and biodiversity conservation maps were integrated in the SDF. However, much of this integration can be credited to the outsourced service providers (consultants) who assist municipalities to develop the SDFs, as opposed to the land-use planners within government themselves. In chapter 3, I conducted interviews with the local municipality land-use planners, in order to gain insight into the extent to which they consider biodiversity priorities, and their use of conservation plans, during daily implementation/compliance processes. The consideration of biodiversity priorities, and the use of biodiversity conservation products, was largely inadequate during daily compliance processes. Another key finding was that there were still human capacity and financial constraints at the local level that prevented the proper and effective functioning of municipal government. Increased competency, and awareness about the importance of integrating biodiversity into local land-use planning, must be raised at local government, especially amongst local land-use planners. The findings of this study have implications for local level biodiversity conservation. A better understanding of the barriers to mainstreaming biodiversity into land-use planning is required by both land-use planners and conservation planners. Resolving these barriers could prevent biodiversity loss and improve biodiversity mainstreaming. At a broader scale, the insufficient use of conservation planning products in local government can have a major impact on efforts to achieve sustainable development goals, and the CBD objectives.
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    Modeling and explaining the distribution of Lantana camara in South African savanna ecosystems.
    (2019) Maluleke, Xivutiso Glenny.; Mutanga, Onisimo.; Dube, Timothy.
    Globally, the Invasive Alien Plant (IAPs) species pose a great threat to global biodiversity, agro-ecological systems and socio-economic development. In particular, Lantana camara (L. camara) is amongst the most notorious and problematic of all invasive plants globally. Its threats and effects are undeniably recognizable and it is ranked amongst the world’s ten worst weeds. As a result, it is one of the most documented weeds in the world. Most studies have focused mainly on detecting and mapping the spatial distribution of L. camara. Although its spatial distribution remains rudimentary, the mechanisms driving its distribution are not yet fully understood, especially in savanna rangelands. This study aimed at modelling and explaining the distribution of L. camara in South African savanna ecosystems (the Kruger National Park and Bushbuckridge communal lands). Specifically, the study sought to identify the environmental factors influencing the spatial distribution of L. camara in savanna ecosystems using the Maximum Entropy (Maxent) algorithm, coupled with remotely-sensed derivatives from Sentinel-2 satellite data. The performance of the model was assessed by using the Area Under Curve (AUC), the True Skills Statistic (TSS) and the Kappa Statistic. From the findings, the Bushbuckridge communal lands had the highest L. camara infestations, with the weed covering an area of 10%, when compared to the Kruger National Park, which had an estimated coverage of 7%. The derived spatial distribution maps from Maxent revealed that communal lands of Bushbuckridge are more vulnerable to L. camara invasion than the protected area. The study also demonstrates that bioclimatic factors influence the occurrence, spread and infestation of this invasive weed species. Comparatively-speaking, elevation was found to have the greatest influence on the infestation and spatial distribution of L. camara. The model that was derived from a composite of all the variables yielded the highest AUC score of 0.96. Subsequently, the model based on indices alone (Model 4) achieved the lowest accuracies, with an AUC score of 0.85. This work is critical for providing the necessary information to assist in effective management and clearing practices by informing the strategic planning, control and rehabilitation of the affected areas.
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    Multi-date remote sensing assessment of invasive Lantana camara species distribution in semi-arid savanna rangelands of South Africa.
    (2019) Madileng, Ngwanamapotu Paschaline.; Mutanga, Onisimo.; Dube, Timothy.
    Invasive alien species pose a massive threat to biodiversity globally. A comprehensive analysis of the spatial distribution of invasive species, like Lantana camara, is essential for providing appropriate management strategies on both a local and regional scale. The main aim of the study was to map and assess the spatial distribution of Lantana camara invasion in savanna rangeland ecosystems over time in Agincourt, South Africa, using high-resolution SPOT 6 data. The first objective of the study is to focus on reviewing the progress in the remote sensing of Lantana camara. A review of the literature shows that previous studies on mapping and monitoring invasive Lantana camara have relied on traditional methods, such as visual interpretations and field surveys, which have been insufficient, particularly for large-scale monitoring. The use of commercial satellite data with a high-resolution has demonstrated the potential for providing fine spectral and spatial resolution capabilities that are essential for offering precise and reliable data on the spatial distribution of invasive species. The challenges encountered in remote sensing of Lantana camara include the problem of similarity in the spectral signatures of the weed and other vegetation species, which leads to a low classification accuracy. The second objective was to map the spatial distribution and rate of change of Lantana camara in savanna ecosystems over time and space. To achieve this objective, a supervised maximum likelihood classification was used for the SPOT 6 satellite images acquired over a period of three years (2014, 2016 and 2018). The results showed that, Lantana camara was distributed over almost the whole study area for all the three years, yet it decreased with time, due to the clearing and disaster programs. Furthermore, the weed then increased and re-established itself between 2016 and 2018, due to failure to do follow-up control after the initial attempts to eradicate it and the failure to remove rootstock. It was again observed that Lantana camara species can be accurately detected and mapped with an overall classification accuracy of >80% for all the three years. However, research with the enhanced spatial and spectral capabilities such as SPOT 6, has shown the importance of remotely sensed data in predicting lantana camara distribution.
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    The use of machine learning algorithms to assess the impacts of droughts on commercial forests in KwaZulu-Natal, South Africa.
    (2020) Buthelezi, Mthokozisi Ndumiso Mzuzuwentokozo.; Lottering, Romano Trent.; Hlatshwayo, Sizwe Thamsanqa.
    Droughts are a non-selective natural disaster in that their occurrence can be in both high and low precipitation areas. However, this study acknowledged that droughts are more recurrent and a regular feature in arid and semi-arid climates such as that of Southern Africa. Some of these countries rely strongly on commercial forests for their gross domestic product (GDP), especially South Africa and Mozambique which means droughts pose a significant threat to their economy and the society that depends on this economy. The risks associated with droughts have consequently created an increased demand for an efficient method of analysing and investigating droughts and the impacts they impose on forest vegetation. Therefore, this study aimed to examine the effects of droughts on all commercial forests within the province of KwaZulu-Natal (KZN) at a catchment and provincial scale by employing Kernel Support Vector Machine (Kernel –SVM), Rotation Forests (RTF) and Extreme Gradient Boosting (XGBoost) algorithms. These were based on Landsat and MODIS derived vegetation and conditional drought indices. The main aim of this study was achieved by the following objectives: (i) to improve methods for classifying droughts; (ii) to achieve medium spatial resolution drought analysis using Landsat sensors; (iii) to determine the accuracy of machine learning algorithms (MLAs) when employed on remote sensing data and (iv) to improve the usability of conditional drought indices and vegetation indices. The results obtained there-after demonstrated that the objectives of this study were met. With the MLAs performing better when using conditional drought indices compared to vegetation indices, therefore, highlighting drawbacks already associated with vegetation indices. Where at the catchment scale, Kernel – support vector machine (SVM) produced an overall accuracy (OA) of 94.44% when based on conditional drought indices compared to 81.48% when based on vegetation indices. On the same scale, Rotation forests (RTF) produced 96.30% and 81.84% when using conditional drought indices and vegetation indices, respectively. At a provincial scale, RTF produced an OA of 76.6% and 70.7% when using conditional drought indices and vegetation indices respectively. This was compared to extreme gradient boosting (XGBoost) which produced an OA of 81.9% and 69.3% when using conditional drought indices and vegetation indices respectively. These results also indicate that it is possible to analyse droughts at provincial and catchment scale. Although the results presented in this study were promising, more research is still required to improve the applicability of MLAs in drought analysis.