Theses and Dissertations
http://hdl.handle.net/11602/2140
2024-03-29T12:25:56ZPerspectives on Wetlands’ Cultural Ecosystem Services and Indigenous Wetland Management Practices in the Limpopo Province, South Africa.
http://hdl.handle.net/11602/2630
Perspectives on Wetlands’ Cultural Ecosystem Services and Indigenous Wetland Management Practices in the Limpopo Province, South Africa.
Metwane, Botete Carol
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.
MENVSC (Ecology and Resource Management); Department of Geography and Environmental Sciences
2023-10-05T00:00:00ZAssessing the impacts of small-holder farming activities on Wetland Area in Nzhelele Agricultural Hub in the Vhembe District; Limpopo Province, South Africa
http://hdl.handle.net/11602/2626
Assessing the impacts of small-holder farming activities on Wetland Area in Nzhelele Agricultural Hub in the Vhembe District; Limpopo Province, South Africa
Mapfumo, Mulisa Norah
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.
MENVSC; Department of Geography and Environmental Sciences
2023-10-05T00:00:00ZA comparative study of sediment characteristics of Sand River and Nzhelele River in Limpopo Province, South Africa
http://hdl.handle.net/11602/2616
A comparative study of sediment characteristics of Sand River and Nzhelele River in Limpopo Province, South Africa
Ramadolela, Zwanga
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.
MENVSC (Geography); Department of Geography and Environmental Sciences
2023-10-05T00:00:00ZComparison of spatial and spectral properties of Landsat-8 and Sentinel-2 data for mapping plant chlorophyll-a
http://hdl.handle.net/11602/2614
Comparison of spatial and spectral properties of Landsat-8 and Sentinel-2 data for mapping plant chlorophyll-a
Bongwe, Vhuhwaho
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
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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.
MENVSC; Department of Geography and Environmental Sciences
2023-10-05T00:00:00Z