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Item Embargo The Impact of Nandoni Dam construction on selected indigenous plant diversity: A case study in Thulamela Municipality within Vhembe District of Limpopo Province South Africa.(2024-09-06) Thovhogi, Ntevheleni Justice; Odhiambo, B. D. O.; Ligavha-Mbelengwa, H. H.; Mokoebo, M. J.The study assessed the impact of Nandoni Dam construction on selected indigenous plant species (IPS) diversity: A case study in Thulamela Municipality within Vhembe District. The construction of Nandoni Dam started in 1998 and was completed in 2005. The research focused on the following three specific objectives: to examine the selected IPS diversity before dam construction, to determine whether some selected IPS diversity were protected after dam construction, and to assess the community’s perceptions on the need to develop long-term management plans for the conservation of selected IPS diversity. The literature reviewed concentrated on the background of the study, problem statement, justification of the study, Environmental Impact Assessment (EIA), and other studies. Under the methodology of data collection and research design, both qualitative and quantitative methodologies were used. Primary data collection includes field surveys, interviews, and observations. Secondary data were collected from documentary reviews, library books, published articles, theses, etc. Permission was requested and granted by the traditional leaders of Tshiulungoma, Budeli, Dididi, and Mulenzhe villages, which were affected by the construction of Nandoni Dam. For systematic data analysis, the researcher used Statistical Package for the Social Sciences (SPSS) Version 25, narrative, and ethnography. Government officials were visited and communicated face-to-face and telephonically. Ethical consideration was granted by UHDEC. Results: Documentation of selected IPS diversity before 1998; photos of submerged and protected selected IPS diversity after dam construction in 2005. Recommendation: Community environment alliance, public community education on EIA reports, and conservation of selected IPS diversity.Item Embargo Assessing climatic and non-climatic impacts on smallholder maize production in Tshimapha Irrigation Scheme, Limpopo Province.(2024-09-06) Mudzanani, Ntsemeni Rainah; Murungweni, F. M.; Chikoore, H.Globally, climatic extremes and non-climatic factors are a major concern due to their emerging and expected impacts on maize production. Climatic extremes come through drought and floods, whilst non-climatic factors include lack of education, poor management, and lack of support. The study evaluated the impacts of climatic extremes and non-climatic factors on the production of maize yield and further examined measures for sustainable production of maize yield in Tshimapha Irrigation Scheme, Limpopo Province of South Africa. The irrigation scheme was established in the 1960s, and today has 115 smallholder farmers, each having 1.5 hectares. Climate data was obtained from the Agricultural Research Council (ARC), South African Weather Services (SAWS) and from literature. Questionnaires were administered among the 115 smallholder farmers. The key informant interviews were conducted among the farmer’s leaders, community leaders and extension officers. The extension officer and smallholder farmers assisted with generating maize yield data. For the first objective, rainfall data was analysed using Mann- Kendall test analysis in R-Studio. Furthermore, Sen’s slope was also done to determine the magnitude of the trend of the rainfall, monthly, seasonal, and yearly and questionnaires were analysed using Microsoft Excel Version 2310. For the second objective, the Standardized Precipitation Index (SPI) was analysed using rainfall data in Microsoft Excel, and the last objectives were analysed using Statistical Package for the Social Sciences (SPSS) by looking at the percentage distribution. The findings of this study indicated an increase in the intensity and amount of rainfall received during flood years, with floods peaking in January and February. The SPI indicated that the area is not prone to severe drought as it is mountainous. The highest production of maize yield was 3.4 tons, with the least being 1 ton per year (based on the available data). Water and land for farming in the scheme were sufficient before the establishment of the Mutshedzi dam, which restricts access to dam water, and the land taken for some of the farmers during the establishment of the dam. This study is in response to national, regional, and global demand for knowledge on how smallholder farmers can adapt to erratic climates and in support of achieving the Sustainable Development Goal (SDG) Number 2. This study can be useful the in working towards alleviating challenges experienced by smallholder farmers in South Africa to ensure sustainability in smallholder production.Item Embargo Synthesis of Zr4+/Ag+ metal oxides modified zeolite for application in fluoride and pathogens removal from water(2024-09-06) Nemakanga, Selby; Mudzielwana, R.; Ayinde, W. B.People living in developing nations are challenged by acute water scarcity, hence they often rely on groundwater as their primary drinking water sources. Unfortunately, in most cases, groundwater is often contaminated with high levels of fluoride and pathogens, posing a significant health risk. This dissertation aims to synthesize Zr4+/Ag+ metal oxides modified zeolite adsorbent for use in fluoride and pathogens removal from water. The first section of this research aimed at optimizing the synthesis of zeolite from bentonite clay using the response surface methodology (RSM). The process involved alkali dissolution of calcined bentonite clay through ultrasonication, followed by hydrothermal treatment to obtain zeolite. The ultrasonication conditions were optimized by varying NaOH concentration (0.5 to 2.5 M) and aging time (10 to 120 minutes). Temperature (70 °C to 140 °C) and time (1.5 to 6 hours) were evaluated for hydrothermal treatment. The X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX) and Fourier transform infrared (FTIR) analysis were used to characterize the obtained materials, revealing that crystallinity of the obtained synthesized materials increased at higher hydrothermal temperatures and times. Furthermore, the XRD analysis indicated there was the formation of zeolite NaP phases at lower temperatures and times, while higher temperatures and times led to hydroxy sodalite mineral phases. Preliminary defluoridation experiments were conducted on all hydrothermally treated samples, with the sample prepared at 2 hours sonication, 105°C hydrothermal treatment, and 1 hour 30 minutes exhibiting a capacity for adsorbing fluoride of 0.19 mg/g hence, this zeolite was used subsequent experiments. The second chapter of results presented the evaluated effectiveness of the synthesized zeolite NaP on fluoride and pathogen removal. Batch experiments were conducted to assess zeolite NaP's effectiveness in removing fluoride from water under various operating conditions while the well-assay diffusion method was used to study the antimicrobial potency of the zeolite. The optimum conditions for achieving maximum fluoride adsorption were identified as a contact time of 60 minutes, an initial concentration of 6.2 mg/L using a synthetic fluoride solution, an initial pH of 2, and an adsorbent dosage of 0.5 g/100 mL. Under these conditions, the maximum adsorption capacity reached 0.16 mg/g. Additionally, it was determined that the fluoride adsorption process followed a chemisorption mechanism, as evidenced by the fitting of experimental data to a pseudo-second-order kinetic model. Moreover, the adsorption isotherm data fitted well with the Langmuir model. This indicates that fluoride adsorption occurred on a surface in a single layer, with a limit on the number of active sites at any given time. Antimicrobial assessments revealed that zeolite NaP lacked v potency against gram-negative E. coli and gram-positive S. aureus strains. In conclusion, zeolite NaP demonstrated minimal defluoridation efficiency and no antimicrobial efficacy. The chapter suggests enhancing fluoride adsorption, antimicrobial potency, and material reusability through the introduction of cations into the zeolite frameworks. The third chapter of results focused on the modification of zeolite NaP by incorporating zirconium/silver metal oxides to enhance its efficacy in removing fluoride and pathogens from water. The Zr4+/Ag+ modified zeolite NaP was prepared using 0.5 M and 0.3 M ZrCl4 and AgNO3 respectively. The mixture of 10 g of calcined bentonite, 2 M of NaOH, and Zr and Ag solutions was subjected to ultrasonication for 2 hours followed by hydrothermal treatment at 105 °C for 90 minutes. The obtained material was therefore characterized using XRD, XRF, FTIR, Particle Distribution Analysis, and SEM-EDS. Defluoridation and antimicrobial potency were evaluated through batch adsorption experiments and well-assay diffusion method, respectively. Under optimal conditions, including a pH of 6 ± 0.5, a contact time of 270 minutes, an initial fluoride concentration of 6.2 mg/L, and an adsorbent dosage of 0.5 g/100 mL at an agitation speed of 250 rpm, the modified zeolite demonstrated a peak fluoride removal percentage of approximately 50%. The data fitted better to the pseudo-second-order kinetic model suggesting the dominance of chemisorption as the fluoride removal mechanism while adsorption isotherm data followed the Langmuir isotherm model suggesting that adsorption occurred on a monolayered surface for the Zr4+/Ag+ modified zeolite. Antimicrobial studies revealed a 15 mm and 12 mm zone of inhibition against the gram-negative E. coli and gram-positive S. aureus strains, respectively. In conclusion, the synthesized zeolite functionalized with zirconium and silver metal oxides exhibited improved fluoride removal efficiency and antimicrobial potency. Further research is recommended to improve the properties of synthesized zeolite for better removal of fluoride and pathogens from water.Item Embargo Assessing the effects of sampling time on the accuracy of extracting water quality indicators through geospatial techniques: A case study of Rietvlei Dam(2024-09-06) Rabohale, Mokabolane Innocent; Malahlela, Oupa E.; Mugwedi, LutendoFreshwater is scarce, and the Earth’s ability to supply it is equally limited. Anthropogenic activities, urbanisation, and the effects of climate change degrade freshwater quality at a rapid rate. To design an effective water quality monitoring strategy that can respond to the rapid changes in surface water, regular sampling and analyses are essential. In developing countries, traditional methods of water sampling and laboratory analyses are adopted to generate water quality information. There is, however, a growing global adoption of optical remote satellite sensing for monitoring water quality, in conjunction with field surveys. One of the main challenges of optical remote sensing is sensitivity to cloud cover, which makes it difficult to synchronise with field surveys. This research addressed the question: “What is the effect of sampling time on the accuracy of extracting water quality indicators through remote sensing and geospatial techniques?”, using a case study of Rietvlei Dam, South Africa. The research established the correlation between laboratory-analysed water quality and the Sentinel-2 (S2) data extracted from the months before, during and after the given field sampling date. This covered four sampling periods i.e., mid-winter, late winter, early spring, and mid-spring. Through multiple regression and accuracy analyses, the study determined the efficacy of the S2 remote sensing models for the chlorophyll-a, turbidity, coloured dissolved organic matter (CDOM) and total suspended solids (TSS) water quality indicators from the different field and satellite sampling periods. The S2 remote sensing models predicted the spatial distribution of the water quality indicators and high concentration area coverage of the dam in hectares (ha). S2 models were found to be best for early spring. Chlorophyll-a was extracted five days after field sampling at R2= 0.79; for late winter CDOM was derived 44 days before the field sampling period at R2 = 0.64; for late winter turbidity was optimally extracted 36 days after field sampling season at R2= 0.54; and mid-winter TSS was extracted seven days before field sampling season at R2=0.62. The turbidity and chlorophyll-a S2 models’ spatial prediction of highly concentrated areas covered 36.14 and 28.92ha, respectively. In conclusion, the accuracies of mapping water quality indicators with remote sensing data and field observations differ based on an indicator measured and the time sampling difference between them. In general, the mapping accuracies decrease outside a seven-day sampling difference, whether before or after satellite image acquisition. This study contributes to the scientific understanding of remote sensing applications to the management of water quality in a given area, especially inland water quality.Item Embargo An evaluation of flood control mechanisms to withstand and adapt to flooding in Vhembe District, Limpopo Province(2024-09-06) Munzhedzi, Lily; Nethengwe, N. S.; Mugari, M. E.The Vhembe district is currently grappling with a rising prevalence of flooding, a phenomenon attributed to a combination of natural elements, such as heavy rainfall, and human-induced activities like deforestation and inadequate infrastructure management. The resultant damages encompass infrastructure destruction, loss of life, crop and soil damage, and environmental harm, with implications extending to human health, housing, livelihoods, government resources, and significant economic consequences. Consequences vary based on the resources and development levels of different areas, emphasising the need to understand each community's unique aspects for the development of resilient flood control strategies. The aim of this study is to evaluate the flood control mechanisms to determine if they can withstand and adapt to flooding in the selected study areas of Musina, Duthuni, and Sane in the Vhembe District. The study pursues two objectives: investigating trends in extreme rainfall and its relationship to flood occurrences, and characterising the nature, effectiveness, and adaptability of flood control mechanisms in the Vhembe district area. Employing a mixed-methods approach, the research design integrates both quantitative and qualitative methods to gain comprehensive insights. The data collection process involved the administration of in-depth questionnaires to participants, coupled with observational analyses of flood control mechanisms. This multifaceted approach allowed for a qualitative assessment of the nature, effectiveness, and adaptability of these mechanisms. Additionally, daily rainfall data sourced from the NASA POWER website was utilised. This data facilitated the computation of an average seasonal precipitation table, the generation of monthly precipitation figures, and tables displaying the count of days when precipitation exceeded the 95th percentile. The findings reveal a recurring pattern of precipitation throughout the seasons, with the highest average precipitation consistently occurring from December to February, and January emerging as a critical month for flood risk. The analysis of flood events spanning from 2000 to 2020 establishes a connection between daily rainfall exceeding 20 mm and instances of flooding, particularly evident in Duthuni, where nearly annual flooding has been observed. The study identified diverse flood control mechanisms linked to the level of development and community traditions. Natural and traditional measures, such as furrows and vegetation-based flood control mechanisms, dominate the rural village of Sane. In contrast, the urbanised Musina prefers engineered solutions like culverts and concrete channels, while Duthuni integrates both approaches. Furrows are popular at the household level across all the study areas, although their effectiveness is considered to be lower in comparison to other household flood control mechanisms. The field observational analysis emphasises the construction of flood control mechanisms using reinforced materials and underscores the importance of regular maintenance. The study underscores the importance of region-specific flood control solutions tailored to local conditions and preferences, considering climate patterns and community traditions. By adopting this approach, the Vhembe district can enhance its readiness and adaptive capacity for flooding. The study's results provide a foundation for well-informed decision-making and policy development, emphasising the necessity for initiatives to align flood management with the distinct challenges and preferences of local communities.Item Embargo GIS based spatio-temporal analysis of crime prevalence in Thulamela Local Municipality(2024-09-06) Daswa, Shumani Samuel; Nethengwe, N. S.; Dondofema, F.Crime is a serious problem with high social and economic costs in South Africa. It is neither unique nor random, but rather tends to be unevenly distributed and has a spatio-temporal pattern. The aim of this research is to analyse the spatial and temporal distribution of crime prevalence in Thulamela Local Municipality using Geographic Information Systems (GIS). GIS applications were used to open new opportunities in crime control and prevention. The spatio-temporal distribution of crime in Thulamela Local Municipality was analysed using GIS tools. This research study adopted both quantitative and qualitative approaches to produce a more comprehensive study of the spatial and temporal distribution of crime in Thulamela Local Municipality. Data was analysed for various argumentations, i.e., spatial distribution of crimes, temporal trends, and identification of hotspots. A Hotspot Analysis (Getis-Ord Gi*) tool was employed to unveil spatial clusters of crime prevalence. The analysis pinpointed distinct hotspots where crime incidents were significantly concentrated. The present study has found that crime incidences are influenced by various factors such as alcohol and substance abuse, domestic violence, illiteracy, poverty, unemployment, and self-enrichment. Thohoyandou was found to be one area with a high crime prevalence compared to Tshaulu and Mutale. Crime analysis did not only deepen our understanding of crime patterns, but also provided actionable insights on the types of crimes that happen in the different areas. By employing a diverse array of spatial and temporal analytical tools, I unearthed trends, clusters, and causative factors, understanding the socio-economic factors that play a role in the number of criminal activities that happen all over the country. As we continue to grapple with the multifaceted challenge of crime prevention, this comprehensive analysis serves as a foundation for data-driven strategies that can enhance public safety and well-being in Tshaulu, Mutale, Thohoyandou, and similar regions.Item Embargo Landfill gas monitoring, assessment of potential health risks and the development of a zero-waste conceptual framework for rural landfills in South Africa(2024-09-06) Njoku, Prince Obinna; Edokpayi, Joshua; Makungo, RachelA landfill is a piece of land where waste (hazardous and non-hazardous) is taken to and buried under the ground; this is oldest and cheapest form of waste management technique. In South Africa, approximately 90% of MSW (Municipal Solid Waste) generated is deposited in a landfill, once it is deposited in the landfill, it undergoes decomposition which generates harmful gases like - methane (CH4), carbon dioxide (CO2) - and trace gases like - hydrogen sulphide (H2S), benzene (C6H6), carbon monoxide (CO), nitric oxide (NO), ammonia (NH4) and toluene (C₆H₅CH₃). These landfill gases (LFG) generated can migrate beneath the sub-surface of the waste into the surrounding landfill area and further extend outside of the boundaries of the landfill. Furthermore, LFG generated can be emitted into the surrounding atmosphere, thereby, contributing to an increase in air pollutants, in the environment. As a result, in South Africa, monitoring the subsurface flow of gases is a mandatory requirement for landfill operators. The objective of this study was to conduct a comprehensive analysis of LFGs from a selected Thohoyandou landfill and develop a zero-waste conceptual framework, based on the Swedish Boras model. To monitor the sub-surface flow of the LFGs, eighteen gas sample probes were constructed with PVC pipes and placed approximately 3 meters below the landfill; these were placed approximately 100 meters apart on the boundaries of the site. A GA 2000 landfill gas analyser was used to monitor the CH4 and CO2 generated from the sub-surface of the landfill. The monitoring of the LFGs was conducted over a period of two years, taking into consideration the wet and dry seasons of the year. Furthermore, to measure the surface emission (near-ground emissions) of the LFG, a flux chamber was constructed from a strong ceramic PVC material with a sharpen based to conceal the flow of LFGs. The LFG samples were collected from the flux chamber using a tedler bag, in the early hours of the day and late hours in the evenings. These LFG samples were immediately taken to the laboratory and a gas chromatography (GC) was used to analyse them. The results from the GC were compared to results generated from the LandGEM model. To monitor the ambient air quality of the surrounding landfill, American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) was used to simulate the LFG emissions in the ambient air. From this process, it was possible to compare these results with real time measurements from the TROPOspheric Monitoring Instrument (TROPOMI) satellite imagery. In addition, the cancer risk of the residents living close to the landfill was assessed. The results of the study revealed that CO2 concentrations were most abundant and surpassed the CH4 concentrations; this is a result of the oxidation process in the landfill. The results indicate that in 2020, CH4 emissions ranged from 0.54 % vol/vol to 2.22 % vol/vol and for the year 2021, the CH4 concentration ranged from 0.24% vol/vol to 2.33% vol/vol, which were found in the months of March and November, respectively. Similarly, the CO2 concentrations for the year 2020 ranged from 4.66% vol/vol to 6.37% vol/vol and in 2021, the CO2 concentration ranged from 3.55% vol/vol to 6.56% vol/vol, which were found in the months of June and September, respectively. The results from the flux chamber show that most of the LFG (near ground) fluxes were from areas close to where there were landfill activities. The study showed that during the wet seasons, CH4 emission in the capped area, had a high concentration of 360819.80 mg/m3, with an average emission rate of 433.00 g/m2/day, resulting in 6363.43 Mg/year. The active sample areas had the highest values, with a concentration of 419863 mg/m3, an average emission rate of 503.86 g/m2/day, and annual emissions of 7031.57 Mg/year. The virgin areas had the lowest values, with a concentration of 45922.52 mg/m3, an average emission rate of 55.11 g/m2/day, resulting in 605.72 Mg/year. Similar results were obtained during the dry season, as the concentrations and emission rates in all areas of the landfill were lower, compared to the wet season. The active and capped sample area had the highest values in comparison to the leachate and virgin sample areas, as experienced during the dry season. The study concluded with the development of a strategic framework for an appropriate MSW management technique, especially, for rural landfills. The designed framework incorporated strategies to - reduce waste, promote recycling, and maximise resource recovery. Thulamela Municipality can encourage waste sorting, recycling infrastructure, and explore innovative technologies in landfill operations, so as to reduce the generation of harmful gases. This study should enhance the understanding of stakeholders in Thohoyandou, around LFG emissions in by providing actionable measures for improving waste management practices, safeguarding community health, and advancing sustainable solutions for environmental challenges.Item Embargo Modelling the spatial distributions and water use of Mauritius thorn (Caesalpinia decapetala) and river red gum (Eucalyptus camal dulensis) using remote sensing and geographic information system techniques in the Vhembe Biosphere Reserve(2024-09-06) Dondofema, Farai; Taylor, Peter J.; Ramoelo, AbelThere is a need for in-depth knowledge of the spatial distributions and water use by Mauritius thorn (Caesalpinia decapetala) and River red gum (Eucalyptus camaldulensis) in the Vhembe Biosphere Reserve (VBR). Three remote sensing imagery platforms were assessed in terms of their ability to classify land cover within the VBR accurately. Supervised classification of Colour Digital Aerial Imagery (CDAI), SPOT 6 and Worldview 2 images was done using Harris Environment for Visualizing Images (ENVI) 5.3 and Environmental Systems Research Institute (ESRI) ArcGIS 10.8.3 software. The Spectral Angle Mapper (SAM) algorithm was used for the three images to identify the best image for the species-level classification. The accuracy of the classifications produced by the three images was evident that had a Kappa coefficient of 0.757 (substantial strength of agreement) for CDAI, 0.80 (substantial strength of agreement) for Worldview 2 and 0.857 (almost perfect strength of agreement) for SPOT 6 imagery. The classification performance of SPOT 6 imagery led to its use for species-level classification. The species-level classification produced an accuracy with a kappa coefficient of 0.8750 (almost perfect strength of agreement). The highly accurate performance of the SPOT imagery was used for subsequent analysis of variation in the distribution of C. decapetala and E. camaldulensis. The species-level classification shows an increased suitable habitat from west to east along the Soutpansberg mountain and riparian areas. Stepwise Logistic Regression (SLR) and Maximum Entropy Modelling (MaxEnt) were used to show the distribution of C. decapetala and E. camaldulensis in the VBR. Twenty-one predictor variables split into environmental and remote sensing data were collected across two seasons (hot-dry, cool-dry) from seventy-four (39 presences and 35 absence sites) for E. camaldulensis and seventy-eight (32 presences and 46 absence sites) C. decapetala from fourteen belt transects and forty quadrants measuring 200 x 200m within the VBR. The stepwise logistic regression analysis shows that variables accounted for significant variations in C. decapetala and E. camaldulensis distribution. The model increases suitable habitat from west to east along the Soutpansberg mountain and riparian areas. The MaxEnt modelling produced an AUC of 0.811 for river red gum, the random, and 0.668 C. decapetala. The two models' high performance indicates high accuracy for the predictability of spatial distribution at the global and local levels. Water is used by IAPS using remotely sensed Evapotranspiration (ET) derivatives from the Food and Agriculture Organisation’s (FAO) Water Productivity Open-access Portal (WaPOR). ET products as a proxy for plant water focusing on E. camaldulensis and C. decapetala in the VBR. The study focused on the WaPOR remote sensing-based products, such as actual Evapotranspiration and Interception (ETIa) and Gross Biomass Water Productivity (GBWP). Analysing the relationship between water loss and biomass productivity products extracted from the FAO WaPOR platform at various spatiotemporal scales. WaPOR products enabled comparing plant water used by C. decapetala and E. camaldulensis within the Luvuvhu catchment. The correlation results indicate that plant water loss (ETIa) and plant productivity (GBWP) show a significant relationship that can be used to understand IAPS distribution. The analysis of the site and ETIa showed significant relationships between F (60.28) and P (0.000) between the ETIa for C. decapetala sites. In contrast, the analysis of GBWP did not show any significant relationship between F (0.85) and P (0.359). In the case of river red gum, analysis of variance (ANOVA) on the sites and ETIa showed significant relationships between F (33.9) and P (0.000) and the ETIa for C. decapetala sites. In contrast, the analysis of GBWP did not show any significant relationship between F (1.59) and P (0.212). Establishing the relationship between vegetation's evaporation and biomass components can broadly indicate how C. decapetala and E. camaldulensis proliferation affect the water use in the Luvuvhu River catchment. This was achieved using water, as represented by ETIa, and plant biomass production in the form of GBWP. A synthesis of the results and provide possible frameworks that can be used for managing IAPS. A framework (Biotic, Abiotic, and Movement (BAM) Framework) that can be considered when using GIS, RS, and modelling to understand the distribution of IAPS was developed. Combining findings, providing recommendations and conclusions for conservation and management. We conclude that GIS, RS, and modelling can be used to monitor and assess the significant spread of IAPS in the VBR. We advocate the inclusion of GIS, RS, and modelling in the management of IAPS in protected areas.Item Open Access Perspectives on Wetlands’ Cultural Ecosystem Services and Indigenous Wetland Management Practices in the Limpopo Province, South Africa.(2023-10-05) Metwane, Botete Carol; Mugwedi, L.; Murungweni, F. M.The cultural ecosystem services of wetlands are the least researched category of ecosystem services because they are not tangible and difficult to quantify for material and non-material benefits. Cultural ecosystem services are non-material benefits communities get from ecosystems and are very important for their well-being. This study assessed people’s perspectives on wetland cultural ecosystem services and indigenous wetland management practices in Sekhukhune District, Limpopo Province, South Africa. The objectives of the study were to identify wetland cultural ecosystem services, to investigate local communities’ perspectives on wetland cultural ecosystem services, and to determine indigenous wetland management practices in Makhuduthamaga Local Municipality. The study was conducted at seven villages whereby each village had a wetland associated with it. A stratified random sampling technique was used at the selected seven villages whereby each village was considered. A simple random sampling approach was used to select the participants to be interviewed for the study in all seven villages. A calculated sample size of 197 of which 119 were male, 76 were female, and 2 others (who are not classified as males or females) participated in the study. Data were collected using individual face-to-face interviews with an interview guide consisting of open-ended and closed questions. Qualitative data were analysed using Atlas ti version 8, while quantitative data were analysed using Stata version 15. The key findings of the study were that: (1) wetlands provide cultural ecosystem services such as religious, spiritual, recreational, and educational services; (2) wetlands are the most respected ecosystems where the gods, ancestors, and water spirits reside, the place of worship and performance of rituals; (3) wetlands are holy with supernatural powers for healing and to drive away evil spirits, bad luck, and witchcraft; (4) traditional leaders are the key stakeholders in the management of wetlands in villages; (5) traditional leaders set taboos and protocols for the sustainable use of wetlands. It was also revealed that non-adherence to taboos and protocols pronounced by traditional authorities’ leads to the anger of the gods, ancestors, and water spirits, resulting in calamities to society. In conclusion, the study showed that there is a positive relationship between community and wetland cultural ecosystem services and between indigenous knowledge and wetland management practices. Then, indigenous knowledge of wetlands conservation must be promoted. There should be continuous community awareness and capacity-building for traditional authorities on wetland management.Item Open Access Assessing the impacts of small-holder farming activities on Wetland Area in Nzhelele Agricultural Hub in the Vhembe District; Limpopo Province, South Africa(2023-10-05) Mapfumo, Mulisa Norah; Murungweni, F. M.; Malahlela, O. E.Wetlands play a crucial role in supplying essential ecosystem products and services, yet they are threatened by several anthropogenic activities. Wetlands are at risk of crop production which depend on the reliability of water supply. The effects of farming on wetlands are a result of the exploitation of wetland resources and the extensive usage of fertilizers. Notwithstanding the alleged role that farming plays in the destruction and degradation of wetlands, wetland area fluctuations and anthropogenic impacts over time and across regions have not been adequately assessed. The aim of this case study research was to assess the impacts of small-holder farming activities on wetland area in Makhado Local Municipality, in Vhembe District of Limpopo Province. Data was collected through interviews and the main data collection tools were a questionnaire, Landsat 8 satellite and UAV images of 2014, 2018 and 2022. The participants of the study included a variety of individuals such as farmers, household heads, extension officer (Mulimisi) and of the community. The Statistical Package for Social Sciences (SPSS) software was used to analyze the survey data. Analysis of satellite imagery was done using Aeronautical Reconnaissance Coverage Geographic Information System (ArcGIS) (Version 10.1) and Earth Resources Data Analysis System ERDAS Imagine (version 2015) software packages. The results show that farming is the major activity within the wetland area over the years 2014 to 2022 which increased from 96 hectares to 181 hectares. Throughout the study period, there have been significant changes to the wetland region. The main contributory factors were the expansion of agriculture (cultivation), increased food demand due to population growth and local water deficit. There is insufficient assistance and mentoring provided by the government to the community and to small-holder farmers when it comes to land use reform and awareness building among villagers and farmers about the importance of wetlands. The results also show that 78.3% of the respondents are not aware that farming has impacts on wetland areas while 17.7% of the respondents are aware. Lack of knowledge has been identified as one of the major factors contributing to the environmental effects of land use change in the wetland area. This study suggested that to manage wetland resources properly, local small-holder farmers and the local community should both be targeted for awareness campaigns and initiatives.Item Open Access A comparative study of sediment characteristics of Sand River and Nzhelele River in Limpopo Province, South Africa(2023-10-05) Ramadolela, Zwanga; Odhiambo, B.D.O.; Kori, E.To describe a sediment and possibly learn more about its creation and depositional processes, grain size statistics might be used. In order to understand the hydrodynamic conditions, mode of transit, and deposition of detrital sediments, grain size analysis is a dynamic sedimentological tool. Fluvial scientists are particularly interested in understanding the relationships between river systems that have been subjected to a variety of forcing factors, such as climate, tectonics, and sea level variations. This study examined the textural, particle size, and mineralogical characteristics of the sediments from the Sand River and the Nzhelele River. At the mouth of each chosen river, a collection of recently deposition sediments was collected to get a representative sample of the watershed. With particular attention paid to Sand River and Nzhelele River. The study's objectives included identifying the grain size distribution pattern of the sediments from Sand River and Nzhelele River and evaluating the mineralogical makeup of the coarse fraction of the sediments from Sand River and Nzhelele River in order to achieve the study's overall goal. In accordance with the "sand suite" methodology, sediments were collected. Using an Excel spreadsheet, the dry and wet sieve methods of grain size analysis were carried out and tabulated, and Gradistat was used to determine Folk and Ward's parameters. The sediments were analysed using a sieve with a 14 Phi-scale (Φ) interval and interpreted using an Excel spreadsheet. The Folk and Ward statistical parameters (mean, standard deviation, skewness, and kurtosis) were calculated using the Gradistat statistics tool. A key factor in the mechanics of sediment travel is a sediment particle's form, which can provide insight on some of the particle's past movement. The Hydrometer method was used to analyze the particle size of sediments to estimate their percentage sand, silt, and clay content. Once the distribution of sand, silt, and clay had been determined, the sediment was classified according to its textural triangle. Using an X-Ray Diffraction (XRD) spectrometer, the mineralogical composition of sand, fine powder, and coarse fraction samples was analyzed semi-quantitatively. This analytical technique revealed the crystallinity and concentration of mineral phases in the samples. The unimodal grain size distribution, which is indicative of a moderate energy environment at Sand River, shows that medium sand to fine sand predominates. The monomodal particle size distribution in Nzhelele River, which is a sign of a high energy environment, shows that very coarse to medium sand predominates there. The majority of the alluvial deposits were sandy, and they were rich in actinolite, quartz, albite, orthoclase, muscovite, and kaolinite. The dominating minerals were leftovers from the minerals in the original parent material and were present in both the sand and silt fractions. They are therefore referred to as fundamental minerals. Quartz (SiO2), a mineral with high weather resistance, comes in first. Albite, Orthoclase, Muscovite, Kaolinite, and Actinolite are other minerals that are frequently found, but in smaller proportions. The mineral makeup of the investigated deposits showed that the minerals at Nzhelele River were Quartz (49.3%), Albite (29.8%), Orthoclase (18.1%), Muscovite (2.1%), and Kaolinite (0.6%), whereas the minerals at Sand River v were Quartz (38.9%), Albite (38.2%), Orthoclase (20.1%), Muscovite (2.5%), Kaolinite (Nil), and Actinolite (0.4%). The two river sediment samples under study had a lot of quartz, according to the chemical composition data. The distance traveled depends on the size of the sediments in rivers; the smaller the size, the longer the journey. The majority of river sediments range from gravel to sand. As sediments typically become coarser with an increase in the energy of the transporting medium, this suggests that the sediments were transported under high energy conditions (Folk, 1974). Due to their longer distance of travel, finer sediments in Sand River were present in greater amounts, but coarser sediments were present in greater amounts in Nzhelele River due to their shorter travel distance. According to the current study, sediments' various textural traits can provide crucial hints for comprehending both their depositional settings and the mechanisms underlying movement. Based primarily on the information supplied by the grain size distribution curves, mineral composition, log-cumulative curves, and grain size distribution histograms, the current Sand River and Nzhelele River samples have been interpreted. According to the grain size distribution, the Nzhelele River sediments are primarily coarse-grained, poorly sorted, leptokurtic, and platykurtic in character, while the sediments from the Sand River are primarily fine-grained, moderately sorted, mesokurtic, and nearly symmetrical. The sediments' fine-sand makeup indicates that fairly lowenergy conditions predominate in the research area. The sediments' well-sorted to moderatelysorted character points to an abrupt winnowing and back and forth migration by the depositing processes. A riverine input and mixing of similar modal fractions may be indicated by the dominance of the nearly symmetrical category. The sediments' unimodal distribution demonstrates the stable depositional process that underwent the deposition of the Sand River and Nzhelele River sediments.Item Open Access Comparison of spatial and spectral properties of Landsat-8 and Sentinel-2 data for mapping plant chlorophyll-a(2023-10-05) Bongwe, Vhuhwaho; Malahlela, O. E.Background Chlorophyll-a (Chl-a) is a vital parameter to assess vegetation quality in plants as an indicator of photosynthetic capacity to ensure proper flow of ecosystem services. Nowadays, with a rapid increase in human population and deforestation chl-a in higher plants remain at risk from degradation. Aim The study sought to compare the spatial and spectral properties Landsat-8 and Sentinel-2 in estimating and mapping chlorophyll-a (chl-a) concentrations in the Vhembe District Municipality (VDM), South Africa. Methods Landsat-8 and Sentinel-2 multispectral data were used in conjunction with field data collected in August 2017, Firstly, this study assessed the correlation between chl-a and satellite data. Secondly, explored the optimal spatial resolution for mapping chlorophyll-a with stepwise multiple linear regression, and lastly, this study mapped the concentration of plant chl-a across a heterogeneous landscape. Results When assessing the correlation between chl-a and satellite data there was an obvious correlation between chlorophyll-a and Band 5 entropy with the highest R² of 0.39 at 30 m spatial scale of Landsat-8. However, there was no statistical significant difference amongst the various spatial resolution. The ability of Gray Level Co-occurrence Matrix (GLCM) texture features with Landsat-8 at medium resolution 30 m with R² = 0.55, p = 0.000006, and RMSE = 0.17 μg/m² in estimating plant chl-a yielded higher performance accuracy than Sentinel-2 at 10 m resolution with R² = 0.24, p = 0, and RMSE = 0.46 μg/m², and 20 m resolution with R² = 0.52, p = 0.00001, and RMSE = 6.90 μg/m². In exploring the optimal spatial resolution, Landsat-8 at 30 m spatial resolution was optimal for mapping plant chlorophyll-a. Lastly, plant chl-a were successfully mapped with Landsat-8 multispectral data at 30 m spatial resolution using multiple linear regression. The distribution of plant chlorophyll-a varies across the study area and is unevenly distributed due to different species and height. Discussions Chlorophyll-a as a crucial parameter in plants and requires continuous monitoring to ensure and improve ecosystem services provided by plants. This study estimated plant chlorophyll-a across the Vhembe District Municipality. The correlation coefficients derived by GLCM’s features demonstrated the ability of GLCM’s features in predicting and mapping plant chlorophyll-a with Landsat-8 at 30 m spatial resolution. Several studies have successfully mapped chlorophyll-a from a homogeneous xii landscape, for instance in agricultural crops and limited studies mapped chlorophyll-a calibrated from a heterogeneous landscape which motivated this study. Recent advancement in optical remote sensing data opens new avenues for mapping plant chlorophyll-a at various spatial resolution. Conclusion The use of remote sensing data at 30 m spatial resolution with GLCM features effectively predicted plant chlorophyll-a and enable the data processing and performance accuracy assessment. Therefore, this study highlighted the importance of Landsat-8 imagery in vegetation monitoring across a heterogeneous landscape.Item Open Access Water Quality Assessment of Rooftop-Harvested Rainwater and its Potential Uses in Vhembe District Municipality(2023-10-05) Vele, Livhuwani; Edokpayi, Joshua Nosa; Ubomba-Jaswa, EuniceRainwater is a major water source which can be harvested and used for various domestic purposes. It is believed that rainwater is free from impurities and soft in nature, making it an alternative source of water for various potential uses, if harvested. This study explores the potential uses of harvested rainwater in the Vhembe District of South Africa. To achieve this, the perception of people towards rainwater’s uses, was assessed as well as the quality of rainwater harvested from various roof types. The physicochemical (pH, turbidity, electrical conductivity, salinity, temperature, and total dissolved solids), microbiological (faecal coliform and total coliform) characteristics, and heavy metals levels in the water were monitored using standard protocols, such as multimeter, membrane filtration technique, and ICP-OES. The relationship between water quality and roof types was also evaluated. Using 110 questionnaires, a survey was conducted with community members who harvest rainwater. The results showed that washing of clothes accounted for the most use of harvested rainwater at 82.73%, in Vhembe District Municipality (VDM). The people of VDM perceived the roof-harvested rainwater as their alternative source of water after municipal-supplied water; 3.6% of the respondents indicated that they have not experienced any adverse effects from the use of harvested rainwater. The reason why residents consider rainwater harvesting has been reported to be mainly due to poor service delivery with respect to water supply by the municipalities. Most of the harvested rainwater’s physical parameters analysed were within the permissible limit of the South African National Standards and World Health Organisation Standards. In comparing all the roof types (slate, steel, aluminium, concrete and thatched) used as catchments for harvesting rainwater, thatched roofs showed very poor standards in terms of physicochemical and microbiological quality of the collected rainwater. The Water Quality Index was evaluated based on the physicochemical parameters focusing on heavy metals and E. coli. All the roof-harvested samples collected in the VDM from the three research areas have an excellent water quality, except water collected from thatched roofs. The results showed that the inclusion of E. coli as a parameter to compute WQI will result in high water quality index value, thereby, proving that pathogenic microorganism play a major role in reducing the quality of water. No carcinogenic risk was computed, based on the levels of trace metals recorded in this study, as the computed Hazard Index and Quotient were all less than 1. Quantitative microbial risk assessment (QMRA), a modelling technique used to estimate the probability of infection and subsequent illness when exposed to pathogenic microorganisms was also calculated. The QMRA calculations all showed the possibility of risk associated with the consumption of rooftop harvested rainwater. This means that continuous consumption of rooftop harvested rainwater without any treatment could pose a great risk to human health, therefore, simple point-of-use water treatment method is recommended prior to the consumption of rooftop-harvested rainwater such as boiling and addition of bleach in order to disinfect harvested rainwater before consumption and food preparation.Item Open Access Assessing the effects of MACADAMIA ORCHARD pesticide inputs on recipient aquatic ecosystems(2023-10-05) Mutshekwa, Thendo; Dalu, Tatenda; Mugwedi Lutendo; Wasserman, Ryan J.Aquatic environments, while not the target of many pesticide applications, often receive chemicals through catchment runoff dynamics. In this regard, the use of pesticides in agricultural systems may have deleterious effects on aquatic ecosystems within the same catchment area. Here using a series of in–situ and ex–situ experiments, the study assessed (a) pesticide concentrations of acetamiprid and chlorpyrifos across MACADAMIA ORCHARD and communal area reservoirs using liquid chromatography tandem mass spectrometry (LC–MS/MS), (b) the behavioural responses of Mozambique tilapia, Oreochromis mossambicus, following exposure to three commonly used macadamia pesticides (i.e., Karate Zeon 10 CS, Mulan 20 SP, Pyrinex 250 CS at different concentrations, (c) macadamia Macadamia integrifolia leaf litter decomposition and mosquito colonisation following pesticide exposure, and (d) macroinvertebrate colonisation associated with introduced stone substrates in cages within the MACADAMIA ORCHARD and control reservoirs to explore whether macadamia pesticides affected on macroinvertebrate colonisation dynamics. Firstly, analysis of acetamiprid and chlorpyrifos associated with sediments in MACADAMIA ORCHARD reservoirs revealed mean pesticide concentrations of 14.48 μg L–1 and 5.67 μg L–1, respectively, whereas, in communal area reservoirs outside of agricultural catchments, both pesticides were not detected. Acetamiprid was not detected across reservoir water, whereas the mean pesticide concentration of chlorpyrifos of 6.51 μg L–1 (MACADAMIA ORCHARD) and 0.13 μg L–1 (communal area) were detected. Secondly, O. mossambicus demonstrated different onset behavioural responses, i.e., swimming erratically, surfacing, vertical positioning, loss of equilibrium, being motionless and mortality with high mortality at increased mortality. Thirdly, macadamia leaf litter tended to decompose faster when exposed to pesticide treatments, whereas chlorophyll–a were reduced. Furthermore, pesticide treatments seemed to promote mosquito (i.e., Culex spp.) and pupal abundances. Finally, a total of 644 macroinvertebrate individuals were recorded across macadamia and communal reservoirs, mostly dominated by Chironominae (55.1 %), Ostracoda (14.4 %), Trithemis sp. (5.2 %), Anax sp. (5.2 %) and Radix natalensis (5.0 %). The results indicate that MACADAMIA ORCHARD reservoirs are highly contaminated by acetamiprid and chlorpyrifos and that these contaminants have implications for the ecological functioning of aquatic ecosystems. Reduction of species diversity adjusted community structure and altered energy flow and nutrient recycling were all demonstrated. The results of the study collectively show how common pesticides used in the macadamia plantation may be exert pressure on adjacent freshwater ecosystems. Future studies should examine effects on trophic interactions, pesticide accumulation in faunal groups and allochthonous trophic transfer dynamics to terrestrial environments. Such information would be useful for managers tasked with mitigation plans for the region.Item Open Access Analysis of soil erodability and rainfall erosivity on the Soutpansberg Range, Limpopo Province, South Africa(2023-10-05) Kori, Edmore; Odhiambo, B. D. O.; Chikoore, H.; Van den Heever, S. C.Soil erosion is a global challenge that threatens ecological functionality. The need for better soil conservation practices keeps growing due to the twin challenges of climate change and population growth. However, effective soil erosion management solutions remain elusive to practitioners due to the complexity of the soil erosion process. This is especially true for mountainous tropical regions which experience rainfall as high intensity thunderstorms accompanied by gusts of wind. Therefore, the aim of this research was to analyse soil erodibility and rainfall erosivity on the Soutpansberg range to establish the characteristics of the factors that influence soil erosion. The specific objectives were to classify geomorphic features of the Soutpansberg range; to characterise the spatial-temporal aspects of potentially erosive rainfall; to assess the influence of topography on wind speed and rainfall erosivity; and to compare rainfall erosivity derived from the USLE and the SLEMSA incorporating WDR erosivity. The classification of geomorphic features needed soil, hydrology, slope, geology and land-use-land-cover data. Soil data were obtained from the Harmonised World Soil Database (HWSD v 1.21) layer downloaded from The International Institute for Applied Systems Analysis (IIASA) online database. Additional soil data were obtained from field samples and splash cups. Hydrological data were downloaded from Department of Water Affairs, Forestry and Fisheries (DWAFF) website. Slope data were derived from the 30m pixel size SRTM DEM obtained from National Geo- Spatial Information (NGI). Geological data were downloaded from South African Geosciences online database. Land-use-land-cover were extracted from the South African National Land Cover 2018 dataset accessed online on the Department of Forestry, Fisheries and Environment website. Rainfall and wind speed data for the spatial-temporal characterisation of rainfall from 2000 to 2019 were obtained from the South African Weather Services. The data analysis followed different tools. Erodibility was assessed using GIS tools to combine the five factors to create a final soil erodibility map. Potentially erosive rainfall spatial-temporal characterisation section was done using spatial GIS interpolation and spatial autocorrelation. Spatial interpolation was achieved through co-kriging. Spatial autocorrelation was determined by the fusion of the coefficient of variation and the Moran’s I. The influence of topography on wind speed and rainfall erosivity was analysed through a Likert scale, simple linear regression and MANOVA. Finally, simple regression analysis and simple comparison were employed to establish the influence of wind on rainfall erosivity. This was treated from the wind free rain (WFR) and wind driven rain (WDR) perspective. The analysis produced the following results. The geomorphic classification for erodibility was based on intrinsic erodibility, landform position, slope position, geological setting as well as rain exposure. The factors operate on fourteen soil types found on the Soutpansberg range that fall into five granulometric groups. The erodibility maps for both USLE and SLEMSA, a result of a weighted sum overlay of all the erodibility factors, show high to very high erodibility on the south facing slopes of the mountain range. A large part of the range Analysis of Soil Erodibility and Rainfall Erosivity on the Soutpansberg Range, Limpopo Province, South Africa on the western part of the mountain range is classified as of very low erodibility in the SLEMSA method. The spatial-temporal characterisation indicates that rainfall on the Soutpansberg Range is very highly variable. The potentially erosive rainfall distribution is spatially dependent on the mountain range and the spatial variation mostly simple. Most rainfall is concentrated in the central areas of the south facing slope. The epicentre is located at elevations above 1200 m.a.s.l. However, rain days are dominated by medium spatial variability. The spatio-temporal characterisation mapping indicates that flash flood hotspots are in low to very low rainfall regions. This implies that high erosion areas are not defined by total rainfall amounts only because the temporal distribution of the rainfall is also important. Furthermore, the simple linear regression analysis revealed that elevation influences erosivity. In addition, hypothesis tests showed that wind speed and topography increase rainfall erosivity. Empirical data confirm that WFR and WDR erosivity are different. Wind Driven Rain computations where wind is above 2 m/s1 produce results similar to samples collected from splash cups. The research concludes that a deep understanding of the factors controlling soil erodibility is the foundation of effective erosion control. The soils’ intrinsic characteristics and raindrop exposure (represented by land use and land cover) explains more of variation in soil loss on the Soutpansberg mountain range. Furthermore, the mountain setting causes rainfall to be concentrated on the central south facing slopes at elevations above 1000 m.a.s.l. sending the very low potentially erosive rain zone to the western region of the mountain range. However, the highest peak of the mountain is in the western region. Erosion hazard potential is not confined to high rainfall zones only. Potentially erosive rainfall hotspots are located in low and very low rainfall zones. Furthermore, rainfall erosivity is not a function of rainfall amount only because topography increases both wind speed and rainfall erosivity. However, rainfall amount and wind speed are not correlated, and wind speed is not implied in rainfall amount. Nonetheless, wind speed is correlated with rainfall erosivity. Wind speed above 2m/s-1 increases rainfall erosivity. therefore, wind driven rain (WDR) erosivity is a better representation of rainfall energy than wind free rain (WFR). The research recommends soil erosion management approaches that also consider rainfall temporal distribution. In addition, further studies on rainfall spatial distribution need to be done using satellite-based rainfall data for more accuracy. Additional research on rainfall erosivity considering rainfall temporal distribution is necessary to identify erosion hazard zones. Intensive and extensive research on incorporating wind speed in the computation of rainfall erosivity can improve soil erosion estimation models. Analysis of Soil Erodibility and Rainfall Erosivity on the Soutpansberg Range, Limpopo Province, South AfricaItem Open Access Bioaccumulation of microcystins in terrestrial food plants and the development of novel sorbents for monitoring microcystins in irrigation water(2023-10-05) Pindihama, Glynn Kuziva; Gitari, W. M.; Msagati, T. A. M.In the past few decades, South Africa's freshwater resources have faced a severe problem of eutrophication and frequent occurrence of cyanobacterial blooms. This is of great concern since some of the cyanobacteria species have the potential to produce cyanotoxins that pose health risks to livestock and humans. Recently, there have been evidence of the toxic effects of microcystins (MCs) and cylindrospermopsin (CYN) on terrestrial plants including plants used for food. Ever since, the use of surface waters contaminated with cyanobacteria and cyanotoxins for agricultural purposes has been receiving growing attention. In hypereutrophic waters, such as commonly found in impoundments around major metros in South Africa, MCs co-exist with other pollutants such as metals and Linear Alkylbenzene Sulfonates (LAS), and these can have synergistic effects on the crops irrigated by such waters and exacerbate the human health risks posed by MCs. The current study investigated the bioaccumulation and effects of MCs on food plants, developed and evaluated the use of crosslinked chitosan (sorbents) passive samplers to monitor the bioavailability of MCs in water intended for irrigation. The findings are presented in six major sections. The first section detailed literature on the impacts of cyanotoxins on food plants with emphasis on the South African context. The reviewed literature demonstrated the potential of exposure of irrigated plants to multiple stressors such as MCs, LAS, metals, endocrine disrupting chemicals (EDCs) and high levels of dissolved salts around South Africa’s urban provinces. The literature also showed that South Africa lacks research on human exposure to cyanotoxins via irrigated crops and regulations to manage emerging pollutants such as MCs in irrigation water. Such lack of data and policies thus prompts an urgent need for local evidence-based research to guide policies and guidelines on cyanotoxins in irrigation water, food plants and, water used for livestock. In the second part of the thesis, the bioaccumulation of MCs in parts of the plants Brassica oleracea (cabbage) and Solanum tuberosum (common potato) was investigated in pot-culture experiments. Water used to irrigate the plants was collected from Roodeplaat Dam and had total MCs ranging from 0.12–2.84 μg L-1. The pH for the water was slightly alkaline (pH 7.29±0.71 to 10.03±0.29) whilst the Electrical Conductivity (EC) ranged from 296.67±13.87 to 878.67±42.44 μS cm-1. The findings showed that the two plants can bioaccumulate MCs to concerning levels when irrigated with water derived from Roodeplaat Dam. MCs accumulation levels in the two tested plants ranged from 0.00142 to 0.136 mg kg-1 DW for individual MC congeners. These findings demonstrated that terrestrial food crops can bioaccumulate MCs to levels that can pose human-health risks. v The third part of the thesis investigated the uptake and accumulation of metals Al, Mn and Sr in distinct parts of the plants Brassica oleracea and Solanum tuberosum in the presence of the anionic surfactant LAS. Pot-culture experiments were conducted to assess the effect of LAS on the accumulation of the three metals by watering the plant with Roodeplaat dam water containing 3.48 mg L-1 of LAS and Mn (0.257mgL-1), Al (0.6mgL-1) and Sr (0.16mgL-1). Findings indicated that the presence of LAS, in the irrigation water, did not enhance the uptake of Sr, Mn and Al by the two plants as demonstrated by the comparable levels of the metals in plants exposed to the metals in presence and absence of LAS. The fourth section investigated the uptake and the accumulation of MCs in distinct parts of the plants B. oleracea and S. tuberosum in the presence of the anionic surfactant LAS. Pot-culture experiments were conducted with the two plant species watered Roodeplaat dam water containing 3.48 mg L-1 of LAS and MCs with mean concentrations of: MC-LR: 10.47±3.879; MC-RR: 6.158± 4.127 and MC-YR: 8.160 ± 2.544 μg L-1. Findings indicated that the presence of LAS in the irrigation water at the levels investigated did not enhance the uptake of MCs by the two plants, even though in some cases the levels of MCs bio-accumulated by the two plants exceeded WHO-recommended tolerable daily intake (TDI). These findings imply that, the tested levels of LAS and MCs did not have any synergic effects on the two plant species. The fifth part of the thesis focused on the synthesis of a composite of glutaraldehyde-crosslinked chitosan and multiwalled carbon nanotubes (ChMWCNT) for application in the Solid Phase Adsorption Toxin Tracking (SPATT) for monitoring MCs in freshwaters. Batch experiments were conducted to evaluate the adsorption efficiency of the composite. The composite was found to be efficient in adsorbing MC-LR showing 97% removal and maximum adsorption capacity of 4.639 μg g-1 under optimized conditions of 5 μg L-1 of MC-LR, adsorbent dose of 0.03g 5 mL-1, and contact time of 30 mins. For desorption, 100% methanol was most effective, with efficiency of 84.71 %. When applied for the adsorption of MCs in raw dam water, the composite was saturated within two days of exposure and effectively adsorbed and desorbed three congeners tested in the order MC-LR>MC-RR>MC-YR. The last part of the thesis evaluated the field applicability of the newly synthesised glutaraldehyde crosslinked chitosan hydrogel (ChGLA) and the composite of glutaraldehyde-crosslinked chitosan and multiwalled carbon nanotubes (ChMWCNT) in a SPATT bag format and compare them to the commonly used DIAION HP20 resin. The constructed SPATT samplers were deployed in canals and farm dams around Roodeplaat and Hartbeespoort Dam sites. The findings elucidated a good vi correlation between the MCs detected by the two newly synthesized sorbents (ChGLA and ChMWCNT) and grab samples. The detected total MCs for the ChGLA samplers were: 0.003 and 1.742 (μg g-1) and for the ChMWCNT samplers 0.006 and 3.300 (μg g-1) (lowest and highest respectively). In conclusion, the two plants were found to accumulate MCs to levels that can pose human-health risks when water derived from the Roodeplaat Dam was used for irrigation. The effects of other pollutants such LAS found in hypereutrophic water bodies on the uptake and accumulation of MCs in food plants was for the first times tested on terrestrial food plants. The findings showed that the presence of LAS had no impact on the uptake of MCs and heavy metals such as Al, Mn and Sr. For the first time, chitosan-based sorbents were synthesized and applied in SPATT for MCs. The use of the chitosan sorbents demonstrated a lot of promise for the monitoring of MCs in water and can possibly be used as an early warning sign for the presence of MCs in irrigation water derived from eutrophicated impoundments in South Africa.Item Open Access The prospects of using the tourism industry to advance community livelihoods in Musina Municipality, Limpopo Province(2023-10-05) Ramaano, Azwindini Isaac; Nelwamondo, T. M.; Odhiambo, B. D. O.This study sought to examine the nature of tourism activities and their contribution to livelihoods for the local communities’ development and sustainability within the study area. The issue of sustainability and tourism has become a widely studied topic in the last few years. However, little research, such as the ones covered in this study, has examined the synergies among the various components of rural tourism. The current study investigated "the prospects of using the tourism industry to advance community livelihoods in Musina Municipality, Limpopo Province, South Africa." It sought to supplement academic knowledge in this area of research. Hence, welfare organisations and local societies within their milieus will benefit from the findings of this study. Sustainable tourism and sustainability were the key concepts that guided the current study. The specific objectives of the research were the following: to identify and analyse the nature of tourism-integrated demographic activities within Musina Municipality; to evaluate the impact of tourism development activities on the livelihoods and socio-economic status of the local communities; to review the nature of the tourism development policy employed by the Musina Local Municipality; to evaluate the environmental impacts of tourism in Musina Municipality; and to develop a strategy for the incorporation of tourism as a tool for sustainable local community development (SLCD). The study employed a mixed approach, utilising both qualitative and quantitative survey methods. The researcher, therefore, applied a purposive sampling method to select participants. This ensured a representative sample by using sound judgement, as well as saving time and money. The study was also underpinned by the researcher’s knowledge of the study area. A questionnaire, interviews, focus group discussions, document reviews, and field observations were used to collect the data for the study. MS Office and Excel, as well as cross-tabulation analysis, were used to analyse the data. Statistical inferences were made from the central tendency and frequency distribution patterns. Data were also presented on graphs and tables. The 99.5% return rate of the survey questionnaire and captured data demonstrated the presence of actual tourism activities. From the data, 92.4% of the respondents supported unexplored tourism potential in their environs. Indeed, the main findings of the study demonstrated significant tourism potential. To that end, focus group discussions (FGDs) [in each focus group discussion, up to 5 individuals were sampled per village] reported significant tourism potential in the study area. Furthermore, 93.5% of the respondents in the survey questionnaire showed that tourism is bringing few benefits to the local communities. In addition, 96.7% of survey respondents reported a lack of knowledge about the principles of tourism development policy in the study area. The findings further showed that an overwhelming majority of the respondents in the questionnaire survey were not knowledgeable about the existing development measures. Hence, there was positive environmental potential for tourism, despite the dismal environmental impacts of tourists and locals on tourism and rural land resources within the Musina Municipality and the study area. It is clear from the findings that there is a need for intervention to promote tourism in the communities. This necessitates comprehensive planning of tourism in the study area in general and the entire municipality in particular. The findings also showed that about half (53.5%) of the surveyed respondents believed that there should be cooperation among all stakeholders, namely, local communities, government, and non-governmental organisations, in rural and sustainable tourism to provide an effective strategy through which tourism businesses can improve within their area. The study findings will provide valuable information on tourism strategies for advancing the communities’ livelihoods. The study also provides a significant stimulus for tourism-related endeavours by the National Department of Tourism, the Department of Environmental Affairs, and the Limpopo Department of Economic Development, Environment, and Tourism in advancing the Musina Municipality and the entire Limpopo Province as a preferred tourism destination in South Africa. It was also reported that Musina Municipality is generally rich in natural biodiversity and has abundant tourism potential. To that effect, a lack of tourism development activities could impair the benefits of actual and potential tourism projects in the communities. Hence, there is a need for a more effective strategy, as also reported by the communities.Item Open Access Water quality assessment and potential ecological risk of trace metals in sediments of some selected wetland across Limpopo Province; South Africa(2023-05-19) Ndlovu, Stanley Skhuna; Edokpayi, J. N.Wetlands are one of the most crucial resources since they provide diverse benefits to the ecosystem. Therefore, South Africa has put in place policies and guidelines to safeguard these valuable resources. This study was conducted to evaluate water quality and the potential ecological risk due to trace metals in sediments across wetlands in Limpopo Province. The samples' physicochemical parameters were tested in the field and the laboratory. All the instruments used to test the physicochemical parameters of the water samples were calibrated first and all the measurements were done in triplicate. The water and sediments samples were digested following the method recommended by US EPA 3015 for aqueous samples and 3050 for sediments samples, respectively. This was done to dissolve the metals that cannot are insoluble in neutral pH but soluble in acidic pH. For trace metals, the digested samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS). Sediment quality guidelines standards for the protection of aquatic life were studied and compared with the threshold effect levels (TEL) and probable effect levels (PEL) as well as effect range-low (ERL) and effect range median (ERM). The potential ecological risk index (PERI) for sediment was studied using indices. The removal efficiency of pollutants from one of the wetlands was calculated to check if the wetland still performs its function. Most concentrations for both the physicochemical parameters and trace metals were within the recommended standards for irrigation and aquatic ecosystem by the Department of Water and Sanitation (DWS) standards formerly referred to as DWAF. However, the dissolved oxygen levels recorded were below the World Health Organisation guideline standard (5 mg/L) in the water of all sampled sites as it reported to be ranged between 0.773±0.155 (W4) to 3.88±1.00 mg/L (W10). In addition, Iron, and manganese exceeded the DWAF irrigation and aquatic protection threshold limit in all wetlands. Fe and Mn varied between W8-12973.62 62 μg/L and W1-77.42 62 μg/L Sediment quality guidelines standards presented levels below the threshold effect levels and effect range-low in most samples. However, few samples presented levels above the threshold effect levels and effect range-low but below the probable effect levels and the effect range median. Most of the sites presented low levels of risk index (RI) values, excluding W3 and W12 which presented a very high risk index (RI) value. The contamination factor values of Cr levels recorded at some sites (W3, W5, W9, W11, W12, W15, and W16), presented extremely high levels greater than CF>32 of toxicity to aquatic biota. Level of contamination (CD) values presented extremely high risk greater than 32 of contamination to 46.67% of sites. Phangami wetland was found to be efficient in reducing the pollution burden of wastewater disposed into the wetlands and recorded acceptable reduction efficiencies for most of the metals recorded.Item Open Access Effects of ash from native and alien plants on phytoplankton biomass and mosquito abundances: A mesocosm experiment(2023-05-19) Netshituni, Takalani Vincent; Dalu, Tatenda; Cuthbert, Ross N.; Dondofema, FaraiWildfires are natural or anthropogenic phenomena increasing at alarming rates globally due to land–use alterations, droughts, climatic warming, hunting and biological invasions. Whereas wildfire effects on terrestrial ecosystems are marked and relatively well–studied, ash depositions into aquatic ecosystems have often remained overlooked, but have the potential to significantly impact bottom–up processes and effects on semi–aquatic taxa such as mosquitoes. This study assessed (i) ash–water–phytoplankton biomass dynamics and (ii) post–colonization mosquito abundances using six plant species [i.e., three natives (apple leaf Philenoptera violacea, Transvaal milk plum Englerophytum magalismontanum, quinine tree Rauvolfia caffra) and three aliens (lantana Lantana camara, gum Eucalyptus camaldulensis, guava Psidium guajava)] based on a six–week mesocosm experiment with different ash concentrations (1 and 2 g L–1). We assessed concentrations of chemical elements, i.e., N, P, K, Ca, Mg, Na, Mn, Fe, Cu, Zn and B from ash collected, and observed significant differences amongst the species. High concentrations of P, K, Mn, Fe, Cu, Zn and B were recorded from Transvaal milk plum ash and low concentrations of P, K, Ca, Mg, Cu and Zn were recorded from apple leaf. An increase in phytoplankton biomass (using chlorophyll–a [chl-a] concentration as a proxy) for all treatments i.e., 1 and 2 g L–1 for all plant species ash was observed a week after, followed by decreases in the following weeks, with the exception of 2 g L–1 for lantana, gum and control. Silicate concentrations (i.e., used as a proxy for diatom abundance) showed increasing patterns among all ash treatments, with exception of controls. However, no clear patterns were observed between native and alien plant ash on both chlorophyll-a (chl–a) and silicate concentrations. We found that ash has notable effects on water chemistry, particularly nitrate, which increased throughout the weeks, whereas, pH and conductivity were high at lower ash concentrations. The impacts of ash on water chemistry, chl–a and silicate concentrations varied with individual species and the amount of ash deposited into the system. Overall, there was no statistically clear difference in colonization between ash from native and alien species. We recorded colonization by two mosquito genera (i.e., Culex spp., Anopheles spp.), with Culex generally much more abundant than Anopheles. Few differences were identified among the plants, with statistically clear effects of ash type and concentration on larval and pupal stages. High Culex egg and larval abundances were shown in lantana and apple leaf treatments compared to controls, and milkplum versus controls for pupae of both genera. Further research is required to elucidate the influence of nutrient inputs from different ash species on vector mosquito population and phytoplankton dynamics.Item Open Access Assessment of groundwater quality and community’s experiences in relation to water quantity and quality challenges in Lephalale Municipality, Waterberg District, Limpopo Province in South Africa(2023-05-19) Mulaudzi, Lusani; Gitari, W. M.; Mudzielwana, R.; Mudzielwana, R.The aim of this study was to assess the water quality of groundwater utilized for domestic and irrigation purposes in Lephalale Municipality, interrogate the community's experiences and issues related to water quality and supply in Lephalale local municipality, Waterberg district in Limpopo province of South Africa. The results showed that the mean values of major cations and anions were in the order; Na+>Ca2+>Mg2+>K+ and HCO3->Cl->NO3->SO42->F-, respectively. About 36% of the sampled groundwater had F- higher than the recommended limit of 1.5 mg/L. For microbial pollutants, 27 % and 41 % of the boreholes were above the threshold set by the World Health Organisation (WHO) in terms of total coliform and faecal coliform, respectively. This can pose health risks to consumers. The hydrogeochemical facies revealed the dominance of mixed Ca-Mg-Cl and Ca-Cl water type which indicated the governance of rock-water interaction. About 19 % of participants from Mmatladi village indicated that they spend over a month without running water in their taps. Households have members suffering from fluorosis (28 %), and most of them do not have knowledge on water quality (78 %). The results revealed that the developed water system could treat 1.68 L of groundwater with 30 g of Al/Fe oxide Diatomaceous Earth (DE) which shows a great potential. The study recommends continuous groundwater quality monitoring in Lephalale Municipality. Due to lack of knowledge amongst the participants concerning water quality, there is a need for public awareness campaign in the area. The developed material for water treatment system needs to be enhanced to increase the adsorption capacity and minimise leaching of elements.