Doctoral Degrees (Geography)

Permanent URI for this collectionhttps://hdl.handle.net/10413/6615

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The influence of floods-recharged soil moisture on tree biochemical and biophysical features in Mbire and Muzarabani semi-arid lands in northern Zimbabwe.
(2025) Pedzisai, Ezra.; Mutanga, Onisimo.; Odindi, John Odhiambo.
In dry lands characterised by scarce precipitation, floods uniquely facilitate soil moisture recharge through deep infiltration. However, the ecological influence of flood-recharged soil moisture (FRSM) on tree growth in semi-arid lands remains poorly understood. To address this knowledge gap, the aim of the study was to assess the influence of floods-recharged soil moisture on tree biochemical and biophysical characteristics in a semi-arid landscape of northern Zimbabwe which was split into the following specific objectives. Firstly, the study sought to assess the utility of remote sensing indices in understanding the nexus between FRSM with tree biochemical and biophysical features in tropical semi‐arid floodplains. Secondly, the study sought to model flood extent mapping in semi-arid floodplains in northern Zimbabwe using Sentinel-1 SAR data. Thirdly, the study sought to assess the utility of deep learning long short-term memory autoencoder algorithm applied on Sentinel-1 SAR data to model FRSM features in semi-arid floodplains in northern Zimbabwe. Fourthly, the study sought to assess the influence of FRSM on short-term biochemical properties of Z. mauritiana tree in semi-arid floodplain in northern Zimbabwe. Finally, the study sought to evaluate the long-term influence of FRSM on Z. mauritiana tree biophysical characteristics in semi-arid lands in northern Zimbabwe. Therefore, to understand the influence of FRSM on trees, this study compared a multipurpose Musawu (Shona) or Jujube (English) (Ziziphus mauritiana) tree species located inside against outside of Mbire and Muzarabani flood-prone semi-arid lands of northern Zimbabwe. The study used an experimental design, flooded constituted the experimental set-up while non-flooded the control set-up for soil moisture, leaf chlorophyll content and tree size variables to enable respective hypotheses of influence of FRSM were tested. Primary and secondary data were collected through fieldwork and downloaded from online repository respectively. Field data measurements included flood extent boundary, tree leaf chlorophyll content measured using chlorophyll meter, tree height measured using a Haglöf Vertex Laser Geo hypsometer, diameter at breast height (DBH) measured using diameter tape and canopy diameter estimated using tape measure respectively. Since floods often occur during cloudy conditions, passive remotely sensed secondary data are commonly inapplicable, hence this study undertook flood extent mapping that used temporal synthetic arperture radar (SAR) data. Firstly, to accurately map flood extent, we innovated an Ensemble of Scenarios Pyramid which is based on change detection and thresholding, utilising a normalized difference flood index (NDFI) framework with Sentinel-1 SAR data. The flood extent map was necessary to spatially discriminate flooded from non-flooded soil moisture, short-term leaf chlorophyll content and longterm tree biophysical characteristics. Secondly, the study innovated a hybrid deep learning Long Short-Term Memory-Autoencoder framework that used temporal Sentinel-1 SAR data to model soil moisture anomaly, lag and memory features compared between flooded and non-flooded locations. Thirdly, short-term post-flood leaf chlorophyll content for flooded tree samples were compared with non-flooded samples using machine learning. Finally, the long-term influence of FRSM on biophysical characteristics was evaluated using canopy diameter, tree height and diameter at breast height (DBH) as proxies of tree growth. The novel Ensemble of Scenarios Pyramid produced a more accurate flood extent map as compared to all the base NDFI scenarios using six metrics (overall accuracy = 93.204%; F1-score = 0.927; Matthews’ correlation coefficient = 0.871; Recall = 0.870; Intersect over Union = 0.865; Kappa = 0.864). The Long Short-Term - AutoEncoder detected positive (wet) FRSM anomaly, with one week lag that occurred starting from the second of February 2017, and initiating a 70-day soil moisture memory inside the flooded as compared to the non-flooded zones. On the shortterm, Random Forest machine learning rejected 43 as unimportant and accepted 16 variables as important to determine leaf chlorophyll content. The flood-related three spatial variables namely distance to river, distance to floodplain and floodplain location were ranked as the most important predictors to determine the short-term FRSM influence on Z. mauritiana leaf chlorophyll content. Thus, on the short-term, the flooded zone (hence FRSM) influenced higher leaf chlorophyll content as compared to the non-flooded zone. On the long-term, flooded trees inside the floodplain were significantly bigger compared to those in non-flooded areas in canopy diameter (p<0.001), tree height (p <0.05) and DBH (p<0.001) using the Levene’s test. Similarly, the Mann-Whitney-Wilcoxn test also showed significant differences in canopy size (p < 0.001), tree height (p < 0.001) and DBH (p < 0.01). Inside flooded locations mapped with the novel Ensemble of Scenarios Pyramid, the innovated Long Short-Term-AutoEncoder modelled that FRSM clearly depicted a minimum of two months longer soil moisture memory than outside. Ultimately, this longer FRSM memory supply soil water for longer to flooded trees than in non-flooded areas, hence the higher leaf chlorophyll content for the former rather than the latter. Consequently, in the long-term, flooded trees inside the floodplain grew bigger than outside as the three selected growth biophysical proxies confirmed using non-parametric tests of differences. In conclusion, the FRSM positively influences soil water recharge in semi-arid lands, which ultimately supports flooded tree growth, thereby confirming the deep infiltration concept noted in the literature review. These results uniquely inform soil moisture and related Z. mauritiana tree management plans in semi-arid lands in view of the current deforestation triggered by its overexploitation by both humans and animals owing to its multiple uses.
Leveraging thermal remote sensing and unmanned aerial vehicle high-throughput phenotyping for assessing and monitoring the water status of neglected and underutilised taro crops in smallholder farming systems.
(2025) Ndlovu, Helen Snethemba.; Odindi, John Odhiambo.; Mutanga, Onisimo.; Sibanda, Mbulisi.
As threats posed by climate change and variability continue to intensify, smallholder farming systems are challenged by the urgent need to sustain crop production and ensure food security. Taro (Colocasia esculenta (L)), a Neglected and Underutilised Crop Species (NUS), has emerged as a promising future-smart crop due to its resilience to drought and heat stresses, holding great potential for diversifying existing cropping systems and enhancing smallholder farming resilience. Despite its reported adaptive capabilities, taro remains vulnerable to prolonged water stress. Such conditions can disrupt internal water balance, leading to reduced equivalent water thickness, increased foliar temperature and decreased stomatal conductance, which can ultimately compromise taro’s tuber quality and productivity. Therefore, accurate and robust monitoring of taro crop water status indicators is essential for the rapid detection of water deficits, facilitating proactive and targeted interventions aimed at mitigating stress impacts and maintaining optimal productivity. Cutting-edge remote sensing technologies, particularly Unmanned Aerial Vehicles (UAVs) equipped with high-resolution thermal cameras integrated with multispectral sensors, have revolutionised precision agriculture. Such technologies have emerged as invaluable tools that enable near-real-time crop monitoring at ultra-high spatial and temporal resolutions, suitable for continuous field-scale assessments of water status. Hence, this study sought to evaluate the utility of UAV thermal remote sensing in assessing and monitoring the crop water status of neglected and underutilised taro crop within smallholder farming systems. Taro is classified as a NUS owing to its limited inclusion in mainstream agricultural research and policy, particularly in Africa and many other regions worldwide, despite its potential to support food security in climate-vulnerable regions. Specifically, this study first adopted a systematic approach to review the progress, challenges, and opportunities in utilising UAV thermal remote sensing to assess and monitor the water status within crop farming systems. The findings revealed that studies utilising UAV thermal remote sensing to assess crop water status are disproportionately concentrated in the global north, with a limited focus on neglected and underutilised crops (> 4 %) and smallholder rainfed systems in the global south (2.3 %). Furthermore, results highlighted that while UAV-derived thermal datasets have gained significant traction, integrating thermal imagery with multispectral data is crucial for leveraging their complementary strengths, enhancing accuracy, and providing a more comprehensive assessment of crop water status. The findings further highlighted the importance of advanced image segmentation techniques in mitigating soil background interference, which can distort crop thermal signatures and compromise the precision of crop water status assessments. As a result, the second objective of the study was to assess the utility of indexbased image segmentation techniques and UAV thermal remotely sensed data in enhancing the estimation of smallholder taro equivalent water thickness (EWTcanopy) as a proxy of crop water status. To achieve this objective, a comparative analysis was conducted to assess the predictive performance of models with and without the thermal band, while also evaluating the effectiveness of Excess Green (ExG), Excess Red (ExR), and Excess Green minus Excess Red (ExGR) image segmentation techniques in improving taro EWTcanopy estimations. The findings revealed that incorporating the thermal band and applying image segmentation, particularly using the ExGR technique, significantly enhanced the prediction accuracy of taro EWTcanopy, leading to a substantial increase in the R² value from 0.32 to 0.92, while the rRMSE was significantly reduced from 60.51% to 15.31%. Having established the importance of integrating thermal data with the ExGR image segmentation technique, the third objective aimed to evaluate the utility of UAV remotely sensed data for high-throughput crop phenotyping of taro equivalent water thickness, fuel moisture content, stomatal conductance, foliar temperature and chlorophyll content as proxies for water status within smallholder farms. The findings revealed that a multi-modal approach, integrating thermal and multispectral data outperforms singlemodal methods, yielding R2 values greater than 0.91 and rRMSEs less than 14.15%. Notably, the thermal waveband and derived thermal indices emerged as the most influential variables for estimating stomatal conductance and leaf temperature, with R² values of 0.96 and 0.95, respectively. In contrast, for equivalent water thickness and fuel moisture content, other spectral variables ranked higher in importance. However, incorporating thermal spectral variables substantially improved the prediction accuracy for these traits, increasing R² from 0.73 to 0.95 (rRMSE reduced from 33.82 % to 14.15 %) for equivalent water thickness, and from 0.77 to 0.94 (rRMSE reduced from 6.55 % to 3.32 %) for fuel moisture content. Subsequently, the fourth objective sought to conduct a multi-temporal analysis of NUS taro crop water status using multi-modal UAV remotely sensed data and deep learning techniques to estimate stomatal conductance and foliar temperature as key physiological indicators across different growth stages of smallholder taro crops. The findings highlighted distinct trends in stomatal conductance and leaf temperature, with the emergence stage exhibiting the highest leaf temperatures and lowest stomatal conductance, while the vegetative stage showed the lowest leaf temperatures and a peak in stomatal conductance. Notably, the vegetative growth stage exhibited the highest prediction accuracies for stomatal conductance (R2 of 0.96, RMSE of 29.34 mmol m−2 s −1 and rRMSE of 12.86 %) and leaf temperature (R2 of 0.95, RMSE of 0.33 °C and rRMSE of 1.11 %). This pattern may be attributed to the limited canopy cover during the emergence stage, where exposed soil temperatures to interfere with crop thermal signatures, in contrast to the vegetative stage where increased foliage reduces soil influence and supports optimal physiological activity. Finally, the fifth objective evaluated the utility of a data-driven approach using UAV thermal and multispectral remotely sensed data, along with topographic variables, to estimate the stomatal conductance and leaf temperature of smallholder taro crops across different growth stages (emergence, vegetative, and maturity) as proxies for crop water status. While integrating multi-source datasets provides a comprehensive evaluation of crop water conditions, it is recommended that advanced feature selection and model optimisation are employed to address challenges of redundancy, multicollinearity and overfitting because of combing large feature subsets. To this end, the findings highlighted the utility of integrating diverse yet relevant datasets, including thermal, multispectral, and topographic data, into a unified data-driven framework for estimating crop water status. Additionally, this study applied critical water stress thresholds (50 mmol m−2 s −1 for stomatal conductance and 35 °C for leaf temperature) to the optimised models, enabling the spatially explicit identification of waterstressed areas within the taro field. Results revealed significant stress during the emergence stage, with 14.18 % of crops showing low stomatal conductance and 37.14 % exceeding the leaf temperature threshold. In contrast, minimal stress was observed in the vegetative growth stage (1.85 %), while the maturity stage showed a slight increase in stress, with 9.36% of the area exceeding the leaf temperature threshold. The findings of this study highlight the critical importance of early-stage monitoring and targeted interventions, especially during the emergence stage, to manage potential negative impacts caused by water stress on taro. Overall, the findings of this study demonstrated the transformative potential of integrating UAV thermal remote sensing with advanced deep learning techniques in providing rapid and robust spatially explicit information on smallholder taro crop water status for ensuring crop productivity and developing early warning systems of water stress. The findings make a significant contribution to the anecdotal knowledge of neglected and underutilised crops, such as taro. Additionally, they play a crucial role in promoting climate-smart agriculture and enhancing climate resilience within smallholder farming systems. Lastly, the implications of this study are aligned with global and regional developmental goals, including Sustainable Development Goals (2 and 13) and the African Union's Agenda 2063 Goals (5), contributing to sustainable agricultural practices that enhance food security and climate resilience. Ultimately, this study is a pathway towards transformative, data-driven frameworks and actionable solutions that could empower decision-makers to support smallholder farmers in proactively adapting to climate variability, enhancing long-term crop viability and fostering resilience and sustainability in the face of intensifying climate stress.
Implications of climate variability and change on urban environmental security: a case study of Lagos Mega-City in Nigeria.
(2024) Akiyode, Oluwole Olusegun.; Bob, Urmilla.
The adverse ecological, political, socio-cultural, and economic consequences of climate variability and change have been documented by scientists in different parts of the world. Therefore, its implications on growing urban societies could affect stability and security in these locations. Thus, in the quest to support the closing of the capacity gaps and to enhance the body of knowledge in the emerging field of urban security in developing economy countries, this study examines the implications of climate variability on the urban environmental security of Lagos Mega-city in Nigeria. The study identifies the impacts of changing climate alongside rapid urbanisation on urban societies and is essential in promoting urban environmental sustainability that stimulates the process of encouraging climate adaptation and building resiliency in cities. The focus on vulnerability is vital given that the urban poor bear a disproportionate burden in dealing with climate variability and change associated with negative socio-economic impacts on livelihoods, infrastructure and basic services, and the natural resource base, especially in the context of limited resources and coping options. Adaptation strategies such as seeking alternate employment and livelihood opportunities, the sale of goods and services, leveraging remittances and external support, and accessing natural resources are undermined. Lagos Mega-city is a continuously growing city located on the coastline of the Atlantic Ocean. The city’s location and rapid population growth make it susceptible to the impacts of changing climate. Subsequently, the study engaged a mixed methodological research design to achieve its objectives. This involved both qualitative and quantitative methods, encompassing exploratory and descriptive approaches. Primary data was collected by undertaking face-to-face interviews using the questionnaire that targeted adults in 400 households from the purposively chosen three communities in the Mega-city. The households were selected from spatial maps using Geographic Information System (GIS) tool and Geospatial Modelling Environment (GME). Other data were collected from three focus group discussions comprising community leaders and fishmongers. Also, information was retrieved through interviews conducted with six key informants who were mainly stakeholders in the government sectors in the city. The analysis of the data from the household interviews was done using the Statistical Package for Social Sciences (SPSS), while the qualitative data from the focus group discussions and key informant interviews were subjected to content analysis. The results and discussions emanating from the data analysis techniques employed were supported by relevant literature on the themes of the study. The study revealed widespread awareness of the issues concerning climate variability and change in the city due to the perceptions of the increasing variations in the intensity of rainfall, temperature, urban heat, level of flooding, and change in seasons in the city. However, there was negligible knowledge and understanding about what contributes to the increase in climate variability and change. Also, the study indicated that changing climate alongside rapid urbanisation features were perceived to be responsible for increasing biodiversity depletion and the enhancement of negative socio-economic impacts on the residents with implications on their livelihoods. Furthermore, the study showed that the communities in the city were engaged in diverse adaptation strategies to counter the impacts of climate variability and change. The study recommends sensitisation of residents on climate issues, initiation of effective urban governance, building climate-resilient infrastructures, and provision of climate variability and change policy as a sustainable urban environmental security approach essential for tackling changing climate issues in the city.
Mapping the spatial variability of foliar C:N ratio in a communal rangeland using remote sensing = Ukuhlela ukuguquka kwendawo eyisilinganiso sefoliar C:N ezimfundeni eziyihlanze zomphakathi kusetshenziswa inzwa yokuqapha izimpawubunjalo zendawo.
(2024) Arogoundade, Mariama Adeola.; Mutanga, Onisimo.; Odindi, John Odhiambo.
Rangelands contribute significantly to livelihoods by providing grazing land, as well as an array of ecological goods and services. However, they are increasingly threatened by among others, alien invasive plant species, climatic variability and injudicious land management. Hence, sustainable use and optimization of rangelands has recently gained attention. Forage nutrients, such as the C:N ratio are valuable indicators of rangeland quality and quantity, and influence rangeland’s carrying capacity and grazing distribution. Therefore, understanding the spatial distribution of foliar C:N ratio in rangelands is valuable for implementing strategic grazing plans and management strategies. Recently, remotely sensed data, specifically the readily available multispectral sensors with improved spectral properties have gained popularity in foliar nutrients modelling. Consequently, this study sought to model fine scale foliar C:N ratio in a heterogeneous communal rangeland using the new generation multispectral sensors. Thus, five objectives were established, firstly; a review of remote sensing applications in mapping foliar nutrients in tropical grasslands. The findings show that the monitoring of foliar nutrients in grasslands, particularly in Sub- Sahara Africa, using high spatial resolution sensors has been hindered by prohibitive costs. Hence, readily available multispectral sensors remain the most viable option in mapping forage nutrients in heterogeneous landscapes. Secondly; to leverage on Google Earth Engine cloud computing platform to monitor the foliar C:N ratio in a heterogeneous landscape using Sentinel 2 data and the random forest algorithm. The results show an estimated R2 accuracy of 74, with RMSE of 2.68 for the validation datasets of the C:N ratio model established by integrating the spectral bands and vegetation indices. Thirdly, the study sought to test the efficacy of fusing Sentinel 2 and Superdove Planetscope datasets in enhancing the rangeland foliar C:N ratio prediction at a landscape scale. The results demonstrate that freely available new generation multispectral sensors with unique spectral settings offer new opportunities for improving forage C:N ratio mapping in resource-poor countries. Using Sentinel 2 data, the study established that the visible, red edge and near infrared regions of the electromagnetic spectrum were influential in predicting the foliar C:N ratio. The study also established that fusing the spatial resolution of Planet scope with the Sentinel 2’s spectral properties enhanced foliar C:N ratio estimation within a heterogeneous landscape (R2 of 0.79 and RMSE of 2.36).Furthermore, the study noted that both Planetscope's high spatial resolution and Sentinel 2 MSI's high spectral resolutions were valuable in determining the spatial variability of foliar C:N ratio and the inclusion of the red edge spectral settings, combining fused datasets with ancillary variables and the adoption of robust algorithms such as Random Forest improved foliar C:N ratio modelling accuracy. Other variables such as wind effect, topographic wetness index, and the sky view factor also influence the foliar C:N ratio spatial variability . Overall, the findings of this study offer new insights on reliable and cost-efficient approaches for mapping forage nutrients in resource-constrained regions such as South Africa. Using freely available advanced multispectral sensors, the study provides valuable information necessary for optimal rangeland management.
Leveraging machine learning for spatio-temporal monitoring of carbon sequestration in urban reforested landscapes in eThekwini Municipality, South Africa.
(2024) Matiza, Collins.; Mutanga, Onisimo.; Peerbhai, Kabir Yunus.; Lottering, Romao Trent.
Urbanization and expanding cities have emerged as major drivers of deforestation, forest degradation, and associated carbon emissions. While urban areas account for a disproportionate share of global greenhouse gas emissions, urban reforestation initiatives provide significant opportunities for climate change mitigation. This study investigates the utility of remote sensing and machine learning techniques for quantifying, mapping, and tracking carbon accumulation and storage by reforested urban landscapes. Through a systematic literature review, multisource satellite data integration (i.e. Sentinel-1, Sentinel-2, Rapideye and Planetscope spectral data), time-series image analysis, and future climate scenario modelling (i.e., CMIP6 models with 3 representative climate pathways in shared socio-economic pathways RCP-SSP), the research demonstrates the capabilities of geospatial analytics for robust carbon monitoring to strengthen localized climate action planning. Key findings showcase the ability of remote sensing spectral data, derived from the multisource satellite integration, to map heterogeneous reforested biomass and model spatiotemporal variations in aboveground carbon stocks across an urban landscape in South Africa, over seven years. Comparative assessment of reforestation carbon accumulation based on ecological history informs management prioritization for optimized climate benefits. Furthermore, simulation of carbon stocks using remote sensing data, climate models and machine learning indicate a shift in carbon accumulation under the three shared socioeconomic pathways, with the low emissions pathway showing an increase in carbon overtime. The methodological framework in this study delivers an adaptable tool for continuous near real-time quantification of urban forest carbon accumulation to support evidence-based decision-making through targeted monitoring, strategic expansions, and adaptive management. While underscoring the immense potential of urban reforestation for mitigation, the research highlights the need to refine an understanding of realized carbon capture rates, utilize emerging data sources such as Planetscope, Sentinel-1 and 2, and Rapid-Eye, expand spatio-temporal assessments, and integrate economic valuations to maximize climate policy impacts. This contributes to sustainable forest management and climate change mitigation. Iqoqa. Ukwenzabudolobha nokukhuliswa kwamadolobha kuvela njengento enkulu egqugquzela ukucekela phansi amahlathi, ukwehlisa izingabunjalo lamahlathi nalokho okuhlobene nokukhipha ikhabhoni. Ngesikhathi izindawo ezingamadolobha zibalelwa ekungahlukanisweni kahle komthelelasivuvu somhlaba sokukhishwa kwesisi umhlaba jikelele, ukuqaliswa kokuqalwa kwamahlathi emadolobheni kwanikezela ngamathuba asemqoka okuqeda ukuguquka kwesimomvama sezulu. Lolu cwaningo luphenya ngokusetshenziswa kwenzwakude namaqhingakwenza okufunda ngomshini, ukubala, ukuhlonza nokulandelela ukuqongelelwa kwekhabhoni nokugcinwa kwezindawo ezitshalwe kabusha amahlathi emadolobheni. Ngokohlelo lokubuyekezwa kwemibhalo, ukuhlanganiswa kwemininingo yesathelayithi yemithombominingi (okuyi, iSentinel-1, iSentinel-2, iRapideye nePlanetscope spectral data), ukuhlaziywa kwemifanekiso yochungechunge lwezikhathi nemodelingi yesiqagulo sangomuso sesimomvama sezulu sangomuso (okuyizinsulakuzo ze-CMIP6 ezimigudu emi-3 emele i-RCP-SSP yesimomvama sesimo sezulu emigudwini yenhlalomnotho okwabelwene ngayo), ucwaningo lwabonisa ukuhlaziywa kokwazi komhlabasikhala wokuqashwa ngamandla kwekhabhoni ukuze kuqiniswe uhlelo olusebenzayo lwesimomvama sezulu esikhona. Okumqoka okwatholwa ucwaningo kwabonisa amandla emininingo eqoqozinhlobo zenzwakude, esuka kundidiyela yesathelayithi emthombominingi, ukuhlonza isiphehlimandla sokutshalwa kwamahlathi anhlobonhlobo nokwahlukana kwesikhashana kwemodeli yendawosikhathi yendawo ephezulu yezitokwe zekhabhoni ezindaweni zonke ezisemadolobheni eNingizimu Afrika, ngaphezu kweminyaka eyisikhombisa. Uhloloqhathaniso lokuqongelelwa kokutshalwa kwamahlathi ekhabhoni okugxile emlandweni wezemvelo kwazisa ngokulawulwa kokubekwa phambili kwemihlomulo eseqophelweni eliphezulu lesimomvama sezulu. Ngaphezu kwalokho, isingakwenza lezitokwe zekhabhoni kusetshenziswa imininingo yenzwelakude, amamodeli esimomvama sezulu nokufunda ngomshini kwakhombisa ukuguquka ekuqongelweni kwekhabhoni phansi kwemigudu emithathu yenhlalomnotho eyatshiwe nemigudu ekhipha kancane ekhombisa ukukhula kwekhabhoni ngesikhathi. Uhlaka lwendlelakwenza kulolu cwaningo lwaletha ithuluzi eliyimvumelanisasimo sokuqhubeka nokubala isikhathi sangampela esiseduze nokuqongelelwa kwekhabhoni yamahlathi asemadolobheni ukuze kwesekwe ukuthathwa kwezinqumo okugxile ebufakazini bokuqashwa kokuqokiwe, amasu okwandisa kanye nokumelana nokulawula. Ngenkathi kugcizelelwa okungaba namandla ukuqeda ukutshalwa kwamahlathi emadolobheni, ucwaningo lwagqamisa isidingo sokukhanyisa kahle ngokuqondwa ngokubonwa kwamazinga okugcinwa kwekhabhoni, ukusetshenziswa kwemithombo yemininingo efikayo njengePlanetscope, iSentinel-1 neye-2, neRapid-Eye, ukwandisa ukuhlola kwesikhashana kwendawosikhathi, nokuhlanganisa isilinganiso sentengo yezomnotho ukuze kubekwe ezingeni eliphezulu imithelela yenqubomgomo yesimomvama sezulu. Lokho kwenza ukuba kube nokulawulwa kokugcinwa kwamahlathi nokuqedwa koguquko lwesimomvama sezulu.
Use of geospatial techniques to improve bee farming and bee health across four main agroecological zones in Kenya.
(2023) Makori, David Masereti.; Mutanga, Onisimo.; Odindi, John Odhiambo.; Abdel-Rahman, Elfatih Mohamed.
Amid augmented climate change and anthropogenic influence on natural environments and agricultural systems, the global socioeconomic and environmental value of bees is undisputed. Bee products such as honey, pollen, nectar, royal jelly and to a lesser extent bee venom are important supplemental sources of income generation especially in the underdeveloped rural African areas. Moreover, bee farming is an important incentive for forest conservation, biodiversity and ecosystem services in terms of pollination services. Bee pollination services play a vital role in crop production, hence directly contribute to food and nutritional security for African smallholder farmers. Nevertheless, bee farming and bee health in general are under threat from climate change, agricultural intensification and associated habitat alteration, agrochemicals intensification, bee pests and diseases. Therefore, there is need to establish spatial distribution of bees, their food substrates, floral cycle and biotic and abiotic threats, especially bee pests. Bee pests devastate bee colonies through physical injury and as vectors of pathogens, hence causing a considerable reduction in bee colony productivity. Thus, this study sought to establish geospatial techniques that could be used to improve bee farming and bee health in Kenya. Firstly, this study aimed to determine the spatial and temporal distribution of stingless bees in Kenya using six machine learning ecological niche approaches and non-conflating variables from both bioclimatic, vegetation phenology and topographic features. All machine learning algorithms used herein performed at an ‘excellent’ level with a true skills statistics (TSS) score of up to 0.91. Secondly, the study assessed the suitability of resampled multispectral data for mapping melliferous (flowering plants that produce substance used by bees to produce honey) plants in Kenya. Bi-temporal AISA Eagle hyperspectral images, resampled to four sensors’ (i.e., WorldView-2, RapidEye, Spot- 6 and Sentinel-2) spatial and spectral resolutions, and a RF classifier were used to map melliferous plants. Melliferous plants were successfully mapped with up to 93.33% overall accuracy using WorldView-2. Furthermore, the study predicted the distribution of four main bee pests (Aethina tumida, Galleria mellonella, Oplostomus haroldi and Varroa destructor) in Kenya using the maximum entropy (MaxEnt) model and random forest (RF) classifier. The effect of seasonality on the abundance of bee pests was apparent, as indicated by the Wilcoxon rank sum test, with up to 6.35 times more pests in the wet than the dry season. Furthermore, bioclimatic variables especially precipitation contributed the most (up to 77.8%) to all bee pest predictions, while vegetation phenology provided vital information needed to sharpen the prediction models at grain level due to their higher spatial resolution and seasonal and phenological features. Moreover, topography had a moderate influence (14.3%) on the distribution of bee pests. Also, there was a positive correlation between bee pests’ abundance, habitat suitability and high altitude. Anthropogenic influence (as depicted by human footprint data) on the distribution of bee pests was relatively low (1.2%) due to the availability of a variety of bee food substrate from the mixed land use/land cover (LULC) classes, especially farmlands. Using the Pearson correlation coefficient, the prediction models for all bee pests scored at an excellent level (0.84), except for the G. mellonella prediction model, which was ranked ‘fair’ (0.55). Due to the relatively high accuracy for models developed herein to map stingless bees’ distribution, melliferous plants and bee pests’ occurrence and abundance, this study concluded that the models developed could reliably be used to indicate high suitability areas for bee farming. They could also be used to predict high bee pests risk areas for mitigation and management purposes, hence improving bee health and hive productivity.
Landscape ecology of coffee pests in smallholdings: influence of landscape fragmentation, farming systems and a warming climate in Murang’a County, Kenya.
(2022) Mosomtai, Gladys Jebiwot.; Odindi, John Odhiambo.; David, Guillaume.; Abdel-Rahman, Elfatih Mohamed.; Mutanga, Onisimo.
Coffee production systems have resulted in simplified landscapes with fragments of natural and semi-natural vegetation characterised by loss of biodiversity, high pests and disease incidences and excessive pesticide input. Consequently, the resilience of coffee landscapes against climate change impacts such as high diurnal temperature range, erratic rains, and prolonged droughts is weakened. Equally, controlling pests and diseases using natural enemies is no longer effective due to the unselective use of harmful chemicals. The present study aimed to understand the role of landscape ecology in a typical smallholder coffee-based landscape in creating suitable ecological conditions for the proliferation of coffee pests, specifically, coffee berry borer (CBB), Hypothenemus hampei, and the Antestia bugs Antestiopsis thunbergii (ABT) and A. facetoides (ABF) in an important coffee growing zone in central Kenya. The study also examined the impact of limiting temperature rise to below 2oC on habitat suitability for growing Arabica coffee to guide the implementation of the Paris agreement, which requires countries to stabilize the global mean surface temperature rise to below 1.5oC and in the worstcase scenario, well below 2.0oC above the pre-industrial levels. Firstly, the study explored Sentinel 2, Landsat 8 and PlanetScope datasets to characterise the smallholder coffee-based landscape and the level of fragmentation in each agro-ecological sub-zones of the upper midland (UM) agro-ecological zone. Sentinel 2 provides a robust dataset for land use and land cover (LULC) classification, with shortwave near-infrared and green bands being critical for classifying coffee bushes. Coffee was the dominant cover type in the higher agro-ecological sub-zones of Kenya, whereas annual crops dominated the lower sub-zones. Secondly, the study sought to identify the significant spatial scale and landscape structure that influenced the abundance of the three coffee pests, given that CBB had a low dispersal capacity and vice versa for the antestia bugs. The results showed that the pests foraged within a radius of 300m, with CBB having the shortest optimum foraging distance of 100m. The CBB abundance was strongly influenced by contiguous coffee patches, especially at higher elevations, whereas adjacent patches were more suitable for antestia bugs, especially cropland in the lower agroecological sub-zones. Thirdly, the shade and edge effect on microclimate and coffee pest abundance were examined. Generally, CBB preferred shaded coffee in the lower sub-zones and full-sun coffee in the higher sub-zones. For Antestia bugs, ABT preferred shaded coffee in all the agro-ecological sub-zones, whereas ABF preferred full-sun coffee, especially in the low sub-zones. Notable also was the influence of the edge effect of agroforest in lowering the mean temperature of full-sun coffee plots. Finally, the study looked at the impact of limiting v temperature rise to below 2oC under the Representative Concentration Pathways (RCP) 2.6 scenario on habitat suitability for growing Arabica coffee. The results showed that the area under coffee will increase, especially in 2070, and the coffee suitable range will shift to lower sub-zones. Overall, the study revealed that the existing landscape structure in smallholder coffee agrosystems favours coffee pests proliferation. Pest pressure at the lower sub-zones is high, especially in coffee plots without shade. However, implementing climate-friendly policies will reverse the current trend, making the lower sub-zones more suitable for growing Arabica coffee. An increase in acreage for planting coffee will translate to more yields, which could alleviate poverty and grow Kenya’s gross domestic product. The study underscores the urgency for smallholder farmers to shift their coffee production systems to climate-smart options such as increasing shade in their plots. This will increase their landscape resilience against climate change and pest control. Additionally, policy makers need to implement climate policies and promote clean energy development to limit temperature rise by the end of the century.
Determination of autumn senescence in subtropical sourveld grasslands, KwaZulu-Natal, South Africa, based on remote sensing techniques: an approach towards forage quality and quantity assessment.
(2023) Royimani, Lwando.; Mutanga, Onisimo.; Slotow, Robert Hugh.; Chamane, Sindiso Charlotte.
Abstract available in PDF.
Quantifying ecosystem services within a reforested urban landscape using remote sensing in eThekwini region of KwaZulu-Natal, South Africa.
(2022) Mngadi, Mthembeni.; Odindi, John Odhiambo.; Mutanga, Onisimo.
Abstract available in PDF.
Detecting and Mapping Forest Nutrient Deficiencies: Eucalyptus Variety (Eucalyptus grandis x and Eucalyptus urophylla) Trees in KwaZulu-Natal, South Africa = Ukuthungatha nokubekisa ukuntuleka kwemisoco yamahlathi: uhlobo lwezihlahla eziyindlulamithi (Eucalyptus grandis x kanye ne-Eucalyptus urophylla) KwaZulu-Natali, eNingizimu Afrika.
(2022) Singh, Leeth.; Mutanga, Onisimo.
Abstract Nutrient deficiencies in commercial forestry environments stunt plant growth and reduce survival, resulting in a loss of time, resources, and trees that can become more susceptible to a host of infections. Ineffective and inefficient nutrient screening methods could lead to the release of unhealthy trees for in-field planting, wasting functional space and inevitably impeding forest production. Therefore, the early detection and continuous monitoring of nutrient deficiencies are essential to support management decisions for an effective nutrient management regime. This research aimed to develop and explore innovative detection techniques to map nutrient deficiencies in commercial forest plantations. The first part provides a synopsis of the application of near-infrared spectroscopy (NIRS) for detecting foliar nutrients, focusing on the best spectral noise removal methods, data pre-processes, and statistical models. The research methodology entailed creating a pot trial experiment to acquire full-waveform hyperspectral data (350nm-2500nm) from 135 young trees in a controlled forestry nursery environment. This research quantified nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and boron (B) in a commonly planted commercial hybrid variety. In the final part the focus was to test the capabilities of unmanned aerial system (UAS) imagery using a very high resolution Micasense sensor and satellite imagery (PlanetScope) in conjunction with an ANN to classify four nutrient regimes in live standing forestry compartment. Overall, this research advocates for the potential use of advanced remote sensing technology to detect and map nutrient deficiencies in commercial forestry environments, at nursery and compartment levels. The results from this study provide an alternative nutrient screening framework for the commercial forestry industry that require quality planting material for long- and short-term resource sustainability on a large scale. Iqoqa Ukuntuleka kwemisoco ezindaweni zokulinywa kwamahlathi amakhulu okuhweba kudala ukuthi izihlahla zingakhuli ziphakame kanti futhi ezinye ziyafa, okuholela ekuthini kuchitheke isikhathi esiningi kanye izinsizakusebenza kanye nezihlahla ezisengozini yokutheleleka ngezifo. Izindlela ezingasebenzi zokuhlola imisoco zingaholela ekuthini kugcine sekutholakala izihlahla ezingaphilile ezingase zitshalwe kanti sekungukukwenzela phansi indawo ebingatshalwa izihlahla ezifanele kanye nokuthikameza ukukhiqizwa kwamahlathi. Ngakho-ke ukuthungatheka kanye nokuqashwa kokuntuleka kwemisoco ngezikhathi zonke kubalulekile ukuze kwelekelele ekuthathweni kwezinqumo ezimayelana nokwenganyelwa kwemisoco efanele. Lolu cwaningo lwaluhlose ukuthuthukisa nokuhlola amaqhinga obuchwepheshe obusha bokubekisa izindawo ezintula imisoco emahlathini amakhulu okuhweba. Ingxenye yokuqala iveza ubufakazi bokusetshenziswa kwe-near-infrared spectroscopy (NIRS) ekuthungatheni imisoco yezitshalo ngokugxila kwizindlelakwenza eziphambili zokuqeda umsindo, nokulungiselela izinhlelo zemininingo, kanye namamodeli ezibalomidanti. Indlelakwenza yocwaningo yaqala ngokwenza ilinge elaziwa nge-pot trial ukuze kutholakale imininingo ephelele ngakho konke okuthungathwayo (350nm-2500nm) ezihlahleni ezisencane eziyi-135 ngaphansi kwesimo samahlathi esilawuliwe. Lolu cwaningo lwakala ubungako be-nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), kanye neBoron (B) ohlotsheni olufanayo nalolu olutshalelwe ukuhweba. Esigabeni sokugcina kwagxilwa ekuhloleni ukusebenza kohlelo lokuhlolwa kwemifanekiso kusetshenziswa into endizayo ingagitshelwe muntu olwaziwa nge-unmanned aerial system (UAS) eneMicasense ekwazi ukuthola imininingwane esezingeni eliphezulu, kanye nemifanekiso ethathwe ngama-satellite (Planetscope). Lokhu kwakuhambisana ne-ANN ukuze kuhlelwe ngezigaba izinhlobo ezine zemisoco ezitholakala emahlathini amilile. Sekukonke, lolu cwaningo luphakamisa ukuba kungasetshenziswa ubuchwepheshe bokuhlola nokuthungatha bukude nalapho kuhlolwa khona ukuze kubekiswe lezo zindawo ezingenawo kahle umsoco odingekayo emahlathini, ezindaweni okukhuliswa kuzo izithombo zezihlahla, kanye nasezindaweni ezisekelwe ukutshala amahlathi. Imiphumela yalolu cwaningo iveza enye indlela engasetshenziswa njengohlaka lokuhlola imisoco emahlathini amakhulu adinga ukutshalwa izihlahla zohlobo oluphezulu esikhathini eside ngaphandle kokuthikanyezwa komkhiqizo.
Transformational adaptation: the community ecosystems-based adaptation assemblage in KwaZulu-Natal, South Africa = Enokuxhumana: Inhlanganisela Yokuxhumana Komphakathi Okugxile Esimeni Sempilandawonye KwaZulu-Natali,eNingizimu Afrika.
(2021) Ramanand, Sarisha.; Nel, Adrian.
Climate change poses a fundamental global threat to society, especially for those who depend directly on natural ecosystems for their survival and sustainable livelihoods. The lack of research on climate adaptation interventions was identified by the 2019 National Adaptation Strategy of South Africa as a stumbling block to climate adaptation. This thesis investigates and tracks the emergence, evolution and scaling up of a Community Ecosystems-Based Adaptation (CEBA) intervention that is operated by Wildlands, an NGO in KwaZulu-Natal, as a local response to the current climate adaptation deficit. My original contribution is the application of an assemblage approach that characterises an integrated CBA-EBA adaptation intervention (Wildlands CEBA Assemblage) as an adaptation assemblage, and to build on the established knowledge of Transformational Adaptation, which is the primary theoretical underpinning of this research. The four study objectives are as follows: 1) to understand the complex range of factors that have influenced the mainstreaming of the Wildlands CEBA Assemblage and a marginalised (adaptation) agenda; 2) to explore the upscaling of the Wildlands CEBA Assemblage; 3) to explore the impacts of the Wildlands CEBA Assemblage on the livelihoods of participating communities in KwaZulu-Natal and 4) to explore the utility of an assemblage approach to understanding adaptation. The thesis embraces a practical approach for advancing knowledge on Transformational Adaptation by engaging with aspects of poverty reduction through livelihood diversification, as well as the challenges associated with the ambiguities and uncertainties. To achieve the research aims, a multiple case study design and a pragmatic and interpretive approach were adopted by using the mixed methods research technique. Interviews for the main study subsequently commenced with 29 key informants and 157 participating community members across seven sites, using a semi-structured interview guide. Thematic and inductive analyses were used to generate data that spoke to the organisational development, poverty reduction and individual capability themes within the research. Furthermore, I developed a CEBA Analysis Framework that focused on analysing and interpreting the research findings by drawing on the theories of assemblage thinking and transformation, guided by the supplementary theories of discourse analysis, managerial roles, sustainable livelihoods and individual capabilities. The assemblage approach is a key contribution to this thesis through which interconnected parts of an adaptation intervention can be investigated. Characterising the Wildlands CEBA intervention as an assemblage brings into perspective how it can spread over time and space, by territorialising different geographical landscapes and communities. In addition, the CEBA Analysis Framework made it possible to assess additional aspects. The discursive dimension of the study shows that changes in climate discourses have influenced the evolution of the Wildlands CEBA Assemblage, by expanding the definition and interpretation of the concept of ‘adaptation’. The results pertaining to the ‘enviropreneurship’ livelihood support mechanism within CEBA revealed an increased awareness of climate change, the potential to reduce poverty by direct monetary gain and the diversification of livelihoods through barter and trade mechanisms within the Wildtrust programme suite. However, the implementation of CEBA was not without some confusing and demoralising effects on the communities. A lack of transparency, communication, capacity building, monitoring and evaluation were overshadowed by other organisational and donor priorities, which enhanced the challenges of achieving transformational adaptation for systemic change. Ambiguity and uncertainty were present in the Wildlands CEBA Assemblage, where varying interpretations of ‘CEBA’ negatively impacted the workforce while daily operational work was undertaken; in many cases, this caused confusion and conflict amongst the participating community members. Overall, the Wildlands CEBA Assemblage was rhizomatic in nature as it expanded across political and geographical boundaries, revealing that upscaling climate change adaptation interventions at a landscape level was indeed possible by employing an integrated CBA-EBA approach. While challenges, changes and ‘reassembling’ occurred, the assemblage remained intact. This thesis contributes to the new ‘Transformational Adaptation’ school of thought by being one of the first studies in South Africa to apply an assemblage approach to a landscapelevel climate change adaptation intervention. The thesis suggests that adaptation studies should not only involve a ‘birds-eye view’ of the adaptation intervention (the whole system) in its entirety, but that it is equally important to scrutinise, explore and investigate the actors, discourses, practices, governance regimes, technologies (the ‘moving parts’ of the system) and incentives that influence the system itself. IQOQA Ukungabi bikho kocwaningo mayelana nokungenelela ekuxhumaneni kwesimozulu ngokwenkathi kwakhonjwa yiNational Strategy yaseNingizimu Afrika yowezi-2019 njengesithiyo sokuxhumana kwesimozulu ngokwenkathi. Le thisisi iphenya iphinde ilandele ukuvela, ukuguquka nokukhula Kokuxhumana Komphakathi Okugxile Esimeni Sempilandawonye (Community Ecosystems- Based Adaptation - CEBA) ukungenelela okwakwenziwa yiNhlngango Engenzi Nzuzo (NGO) eWildlands, KwaZulu-Natali, njengempendulo yendawo esimweni esikhona sokwesweleka kokuxhumana kwesimozulu ngokwenkathi. Kwabe sekuqhubeka izimposambuzo zocwaningo olumqoka nababambiqhaza abaqavile abangama-29 namalungu omphakathi ayebambe iqhaza angama-157 ezindaweni eziyisikhombisa zaKwaZulu-Natali, kusetshenziswa isiqondiso semposambuzo esakuhleleka. Ithisisi yathatha indlela eyinhlanganisela ukutshengisa ukungenelela (Wildlands CEBA Assemblage) njengendlela yokuxhumana kwenhlanganisela; uhlelo (oluphelele) oluhlanganisa imisuka eminingi eyinhlanganisela (izingxenyana zohlelo). Le ndlela yavumela ukuphenya izingxenyana ezixhumene zokungenelela kokuxhumana njengoba yasabalala ngokwesikhathi nangokwendawo, igwamandela imimo yezindawo nemiphakathi. Ubukhulu nobubanzi bocwaningo bukhombisa izinguquko ezingxoxweni zesimozulu senkathi, kwaba nomthelela ekukhuleni kweWildlands CEBA Assemblage, ngokukhulisa incazelo yokuhunyushwa komqondomsuka ‘wokuxhumanisa’. Le ndlela yaphinda yagqamisa imithelela yokuncishiswa kobubha ngokwahlukanisa izindlela zokuziphilisa kuyona, nanezindaba ezihambisana nongabazane nokungacaci okwavela ohlelokwenzeni. Naphezu kokuthi ukufakwa kweCEBA kwakungaphuthwe zinselelo, imiphumela yaveza ukuqonda okukhulile kwesimozulu senkathi, nokungenziwa ekwehliseni ububha ngokukwahlukanisa izindlela zokuziphilisa nempilandawonye ethuthukile. Le thisisi inikelela esimeni somcabango ‘Sokuxhumana Kokwenguquko’ ngokuba ngolunye locwaningo lokuqala eNingizimu Afrika ukusebenzisa indlela eyinhlanganisela ekuxhumaneni nasekungeneleleni ekuguqukeni kwesimo sezulu ngokwenkathi ezingeni lendawo. Ithisisi iphakamisa ukuthi izifundo zokuxhumanisa kufanele zingagcini nje ngokufaka ‘ukubuka ngeso lenyoni’ ukungenelela kokuxhumana ngokuphelele, kodwa kuphinda kube semqoka ukuxilonga, ukuhlola nokuphenya abadlali, izingxoxo, okwenziwayo, izinhlaka zokuphatha, ubuchwepheshe nezikhuthazi okunomthelela ohlelweni uqobo lwalo.
Estimating and monitoring the phenological cycle of bracken fern (Pteridium aquilinum) using remote sensing.
(2022) Matongera, Trylee Nyasha.; Mutanga, Onisimo.
Abstract available in PDF.
Abandoning the Ark in Durban: development, displacement, resettlement and livelihood struggles.
(2021) Fitzgerald, Tara Jade.; Maharaj, Bridgemohan.
Forced removals, the theme of this thesis, through evictions, clean-up campaigns and development-induced displacement, results in the ‘hygienisation’ of public space and the ‘violent un-homing’ of vulnerable communities. The Ark Christian Ministries Church (ACMC) was established in 1982 in Durban’s notorious Point Precinct, offering shelter and rehabilitation opportunities for socially excluded and marginalised persons in the inner city. As the city forged ahead with the Point Waterfront Development mega-project and prepared to host the 2010 FIFA World Cup, the Ark was shut-down in 2004. Notwithstanding a spirited resistance, one hundred families were forced to relocate to Welbedacht East, 30km from the Point Precinct. The aim of this study is to examine the implications of Development-Induced-Displacement and Resettlement (DIDR) on the livelihoods of those displaced from the Ark homeless shelter in the Point Precinct in Durban, and their survival strategies after relocating to the urban edge in Welbedacht. Influenced by theories of displacement, social justice and human rights, this thesis analysed the displacement, resistance, relocation and livelihood struggles of the Ark dwellers. A mixed-method approach was adopted in this study, drawing from qualitative and quantitative techniques and information from documents. The study found that those displaced remained socially excluded and marginalised in Welbedacht and expressed a deep sense of detachment and hopelessness. Their lives were characterised by unemployment, poverty and social pathologies. The former Ark residents failed to restore their livelihood opportunities and remain in a constant state of precarity. The study identified a new form of displacement. ‘New-Place Displacement’ refers to the inability to adapt to the new environment or integrate with surrounding communities. Instead, the ‘Arkians’ remained in a constant state of alienation in Welbedacht.
A model of communities' perception of municipal service delivery in South Africa with particular reference to Pietermaritzburg.
(2000) Dalton, David Robert.
Abstract available in PDF.
Assessing the condition of unpaved rural road networks and the associated impacts on the livelihoods of rural communities : a case study of four rural communities in Kwa-Zulu Natal, South Africa.
(2018) Nkomo, S'phumelele Lucky.; Peerbhay, Kabir Yunus.; Desai, Sumaiya Amod.
Unpaved road networks, also referred to as gravel or unsealed roads, form an integral function in terms of sustaining the well-being of rural livelihoods, particularly in remote rural areas. The socioeconomic spinoffs of improved rural road networks have been extensively researched in Asia, but not to the same extent in the African continent. Even though the South African economy has consistently been stronger than many countries in Africa, there is more research conducted in Kenya and Ghana on unpaved road network conditions when compared to South Africa. The present study therefore assesses the condition of rural road networks and the associated socioeconomic impacts on the livelihoods of rural areas within the province of KwaZulu-Natal. This study was conducted in four rural areas namely Emazabekweni, Dukuza, Mkhunya and Mhlwazini within the province of KwaZulu-Natal. Due to the complex nature of the research, a multidisciplinary approach was adopted in order to address the aim and objectives of this study. In addition, This study used both quantitative and qualitative methods in the data collection and analysis. The first part of this study was an assessment of the physical conditions of the gravel road networks in rural communities in order to understand the physical, environmental and anthropogenic factors that influence the state of rural roads. Results showed that there was a direct relationship between road surface characteristics, drainage and maintenance conditions. The results further showed that the nature of road surface distresses was an indication of the influence of traffic and climatic conditions. The second part of this study focused on investigating some of the primary causes of poor road conditions on unpaved road networks. An assessment of surface material quality was performed on the road classes selected for this study in order to understand their susceptibility to surface deterioration. The results obtained indicated that there was a need for better material selection during the construction of unpaved road networks. Most of the road classes assessed had poor material quality, thus making them vulnerable to increased surface deterioration and maintenance costs. The third part of this study assessed local respondents' perceptions on the socioeconomic role of their unpaved road networks on their livelihoods. The findings obtained perceived that local respondent’s perceptions on the socioeconomic role of unpaved road networks on their livelihoods are influenced by the effectiveness of their roads in servicing their needs. Less than ten percent of all the respondents perceived direct economic spinoffs as a result of road networks improvements. Majority of the respondents perceived social spinoffs such as improving access to healthcare, education and market services. Finally, this study identified and assessed the effectiveness of Community Based Maintenance Strategies that were utilised for routine maintenance of unpaved rural roads. The findings emphasised that Community Based Road Management Strategies such as the Zibambele Road Maintenance programme provides an alternative approach that was useful and can be effective on the maintenance of unpaved rural road networks. The major criticism for Community Based Road Management Strategies was that they lack sufficient prioritisation of personnel training and this justification was observed during the assessment of the Zibambele maintenance programme on the selected road lengths. The overall findings of this study showed that community proximity to towns biasedly determined amongst others, quality of unpaved roads, access to services and the availability of opportunities for income diversification. In this study, the communities that are located close to a town had better quality road access in comparison to communities that are further away from a town. Similarly, these communities had better services and access to services in comparison to communities that are further away from the town. The findings of this study could be used to reassess some of the primary challenges affecting rural economic growth as well as social stability.
Rural livelihoods and adaptation to climate variability and change in Chadereka Ward 1 in Muzarabani rural district, Zimbabwe.
(2017) Manyani, Albert.; Bob, Urmilla.
Climate variability and change has become a major concern locally and globally that has negative impacts on the sustainability of livelihoods as well as socio-economic and environmental well-being. There is also widespread consensus that developing contexts, especially in sub-Saharan Africa, will be most impact by climate variability and change given low coping and adaptive capacities as well as persistent inequalities, poverty, governance challenges and environmental scarcities and degradation which make communities highly vulnerable. In the quest for data generation, which is still scanty and lacking in Zimbabwe, this research sought to assess the sustainability of the rural livelihoods and adaptation strategies to climate variability and change in Chadereka Ward 1 in Muzarabani Rural District, Zimbabwe. In this endeavor, policies governing the execution of the livelihoods were examined and awareness levels of the households determined. Being informed by relevant literature and primary data collection, the research further explored the impacts of climate variability and change on biophysical and socio-economic conditions before examining the adaptation strategies to the climatic phenomena. Challenges faced by household respondents in adapting to climate variability and change were established. Finally, an evaluation of stakeholder roles in promoting sustainable rural livelihood adaptation to climate variability and change was undertaken. As a purposively sampled case study, a mixed approach research design was followed in gathering data from Chadereka Ward 1. The data was collected from 310 household respondents and 10 key informants. This was augmented by 3 focus group discussions and direct observations. Descriptive statistics, using SPSS version 21, regression analysis and content analysis were useful in data presentation and analysis. Farming, gathering and service provision emerged as the dominant current livelihood practices in the study area. Some household socio-demographic characteristics were found to significantly influence the uptake of both livelihoods and their adaptation to climate variability and change. A combination of adaptation strategies pursued in the Ward, such as agroforestry, conservation farming, irrigation, drought tolerant crop and animal variety, livelihood diversification and flood recession cultivation were hampered by mainly institutional forces such as the lack of financial support, poor infrastructure, unfavorable marketing conditions and lack of alternative fuel sources. Generally, climate variability and change have had negative impacts on the biophysical and socio-economic conditions in the Ward evidenced by water scarcity and reduced livelihood portfolios. The results further revealed a low level of climate variability and change knowledge at the household level. Properly constituted, enhanced and effectively monitored policies regarding the management of the natural resources are required to ensure their sustainability. Without these, the sustainability of the practices in the Ward remains greatly compromised. This also calls for more capacity building and resource mobilization and intervention.
Long-term and climatological studies on sulphur dioxide (SO²) using ground based and space-borne measurements over South Africa.
(2018) Venkataraman, Sangeetha.; Gebreslasie, Michael Teweldemedhin.; Wright, Caradee Yale.
Abstract is available in the PDF file.
Motivations to engage in dark tourism : the case of selected sites in South Africa.
(2017) Nhlabathi, Sibonakaliso Shadrack.; Maharaj, Bridgemohan.
The aim of this study was to understand motivations to visit dark tourism sites, particularly, in South Africa and generally internationally. Dark tourism or tourism to places associated with death, pain and suffering is relatively new and under researched. Although dark tourism literature is growing, there was still some uncertainty in academic circles about its theorisation and conceptualisation. Some have argued that dark tourism was just branding in a competitive academic landscape. Touring places associated with dark events started back in the Middle Ages, however, since the last quarter of the 20th century there had been a notable increase in the organisation of tourism to dark attractions. The negative sightseeing concept appeared to be the first concept to be used in the 1970s to characterise this form of tourism. However, meaningful scholarly endeavour to understand this phenomenon emerged in the 1990s. The concepts that emerged during this time to dominate theorisation of dark tourism are thanatopsis (contemplation of death), and intimations of postmodernity from which the dark tourism concept emerged. The dark tourism concept has become popular in literature. Some of the other terms which have been used to describe tours to places associated with dark events and to describe sites of that nature are: black spots tourism, assassination sites tourism, dissonant tourism, morbid tourism, disaster tourism, conflict tourism, poverty tourism, slum tourism, landscapes of violent tragedy, and, geographies of trauma. This study was conducted at three sites in South Africa: the Robben Island Museum, the Hector Pieterson Memorial Museum, and the Apartheid Museum. This study was concerned with a deeper understanding of tourists’ motives to engage in dark tourism in general, and to tour the research sites in particular. Further this study explored how tourists and curators (of the museums, the research sites) interpreted them. The research adopted a qualitative research approach which stressed social interaction, social construction, and the creation of meaning. Qualitative research approach is a major tool in the pursuit for a deeper and broader understanding of the meanings of events, activities, situations and actions of research participants. This study revealed that visitors toured dark tourism sites intentionally in order to: pay homage to the victims of difficult pasts; learn, especially history; remember victims of difficult pasts; pay homage to Nelson Mandela, and connect with South Africa’s political struggles. Visitors also toured the dark tourism sites because they were in bigger trips which also involved visiting nature reserves. Tourists labelled visits to nature reserves as safaris; finally, visits were motivated by curiosity and desire to know. This study found that the following intermediaries played important roles in influencing visits to dark tourism sites: tour operators; educational institutions in the USA; television, internet, and social media; TripAdvisor; Nelson Mandela’s autobiography, Long Walk to Freedom; and friends. This study also found that tourists who toured as a couple, it is usually women spouses who normally initiate the trips. Curators presented the research sites as places where people learned about: past injustices, prejudice, and suffering. Curators further hoped that visits to the research sites would touch visitors intellectually, emotionally, and spiritually. Visitors interpreted dark tourism sites as: educational and cultural places; sometimes gloomy and emotional, but still educational sites; and, also as special places, sites of freedom, sites of empowerment, and, as shrines. Tourists were generally positive about sites, however, some hoped for platforms that facilitated interactivity as opposed to passive reception of information. This study also found that some tourists had some issues relating to the organisation of the tours to the Robben Island Museum. This study divided recommendations concerning policy and management of the research sites into: recommendations directed to the Government and recommendations directed to the three sites of this study. With respect to the Government this study recommended that wild-life be protected by all means because it is the main draw card for international tourists. This study also recommended that the South African and the Zimbabwean governments cooperate in matters of tourism. This should be so because most tourists combined visits to South Africa with visits to Victoria Falls in Zimbabwe which visitors described as safaris. With regards to the three study sites, this study made recommendations that if the research sites wished to attract more tourists, they might consider doing the following: work with tour operators; make use of social media (face book); and integrate the concept of active visitor engagement mostly for purposes of attracting younger visitors. This study also recommended that the Robben Island Museum should revisit their idea of the Museum tourism experience because a few visitors voiced some concerns regarding the organisation of the tours.
City-to-city learning in urban strategic planning in Southern Africa: unearthing an underground knowledge economy.
(2016) Moodley, Sogendran Mogambary.; Bob, Urmilla.
Despite international evidence strongly suggesting the need for urban strategic planning, most African governments still continue to under-invest in the establishment of bottom-up strategic planning frameworks. The seriousness of the consequences of such inadequate urban strategic planning responses and ineffective governance in developing economies has been flagged by the World Economic Forum (WEF), identifying it as a key global risk in 2015. What is of particular interest in their analysis however is the observation that governments of rapidly growing cities make very little time for learning from other cities to improve their own planning processes. Whilst the above assertion may be true, targeted research on city-to-city learning conducted predominantly in the global North is showing that cities are in fact quietly forming an international web-work of learning representing an almost invisible, underground knowledge economy. Given the highly conspicuous void in empirical research into city-to-city learning in urban strategic planning processes in the (southern) African context, this doctoral study focuses on a United Cities and Local Government (UCLG) case study using the experience of three African cities, Durban in South Africa, Otjiwarongo in Namibia and Mzuzu in Malawi, to shed light on the phenomenon of city-to-city learning. In particular, the research explores what insights are offered by the eThekwini Municipality’s mentorship program with these selected Namibian and Malawian municipalities that begin to inform contemporary learning theory in southern Africa. Rejecting a grand meta-narrative in favor of a more pragmatist, hands-on and bottom-up, context specific interpretation of social reality; the research adopts a multi-conceptual lens by drawing from the urban planning and organizational learning disciplines. The study utilized a mixed methods approach with both qualitative (key informant interviews, focus group discussions and observation) as well as quantitative (census survey of a total of 34 respondents) data integrated into the study. The study yields a set of illuminating results which begins to challenge currently held definitions and learning terminology. More importantly, a learning model is developed with five clearly delineated stages in the city-to-city learning process. In addition, the research is able to distil the valuable lessons emerging from the in-depth case study to propose a broad, but coherent learning framework, with a set of strategic recommendations to guide future city-to-city learning processes. These recommendations which have been shared with the international learning stakeholders are already beginning to transform the learning landscape in southern Africa and beyond.
The dynamics of urban water service delivery capacity and the implications for household food security in Gweru, Zimbabwe.
(2016) Kusena, Winmore.; Beckedahl, Heinrich Reinhard.
Water is a resource on which all human activities, in both rural and urban environments, are anchored. Due to limited social security in developing countries and associated challenges, water is relied upon directly, and heavily, for food security. Several studies focusing on the relationship between water and agriculture have been conducted mostly in rural areas of Zimbabwe. Whilst the water and food relationship was historically associated with rural settings in Zimbabwe, the urban environments are now increasingly identifying with the relationship for survival due to national economic underperformance. Currently, no research has focused on the dynamics of domestic water service delivery system and the implications for household food security in urban areas. Research has been turning ‘a blind eye’ to the effects of reported water shortages and water affairs on household food security in Zimbabwean cities. In view of this, the present study assessed the urban water service delivery system and its implications on household food security in Gweru, the fourth largest city of Zimbabwe. Therefore, the capacity of Gweru municipality to supply water to citizens was assessed. Capacities investigated were the availability of water at source as well as the municipality’s financial, human and infrastructural capacities to supply water to citizens. The findings revealed that the city had sufficient raw water at source to supply the city. Nonetheless, the infrastructural capacity to pump water to the city was limited. Financial incapacity was identified as the major drawback that crippled the system in terms of both adequate human resources and infrastructure development in the city. Results revealed that the municipality was further financially incapacitated by water debt cancellation that was implemented in the year 2013. The shortfall between supply and demand was assessed. Using World Health Organisation (WHO) guidelines on recommended per capita water per person, results showed a significant differ This situation prompted the researcher to investigate the role that water users were playing in the incapacitated system in order to optimise the limited resources. Adequacy of user participation in the water supply system was assessed using a perception study. Results show that despite all the incapacities, the service provider was not capitalising on working with residents in order to maximise conserving the available resources. Gweru municipality and the city’s residents had poor communication. This perpetuated a tendency of non-compliance with water conservation and demand management strategies as respondents felt disregarded. The municipality was seen as dictatorial, imposing decisions to do with water rationing and revenue collection on residents mutatis mutandis, without adequate consultation and notices. It was in the context of the limited water supply and demand management capacities, the widening supply and demand gap as well as inadequate user participation that household food security was assessed. Results show that municipality’s efforts to continue providing service sometimes led to serious cost recovery and revenue collection that culminated in excessively high bills and serious follow up on payment that, in most cases, led to disconnections. Residents suffered water cuts and reduced food production prospects from their gardens due to plant wilting. The study further revealed that the municipality allowed backyard farming irrigation, but then capitalised on increased bills that were mostly based on estimates. The high monthly bills also crippled the residents’ food buying power, making them more vulnerable to food insecurity. The municipality imposed decisions that make the utility fulfil its mandate of supplying water at the expense of the intended beneficiary, the user. The results show that the measures taken by Gweru city council seriously compromise household food security. The study further assessed the coping strategies that were devised by respondents and civil society groups to counter water shortages and water related household food insecurity. Results reveal that respondents embarked on both legal and illegal strategies for survival. Due to inherent poor communication between the authority and residents, most of the coping strategies devised by respondents, such as self reconnection to water supplies, exhibited deviant behaviours due to lack of options, further increasing the amount of non-revenue water consumed. Twenty two percent of respondents demonstrated their willingness to cooperate with the municipality through payment plans, although 18% of them revealed the ineffectiveness of the option since bills continued to increase. In order to cushion the residents from water shortages and food insecurity, civil society rolled out boreholes and community garden projects in the city. The findings of this study demonstrate the importance of capacity building and development in the water service delivery sector. The study highlights the need for stakeholder engagement, in a bid to optimise resource utilisation amid limited capacities. The findings of the study further show the importance of people-centred approaches in resource management in order to achieve sustainability. Lack of an integrated approach in water service delivery in Gweru led to more disgruntled and vulnerable citizenry that perceives hegemony and prejudice. The findings have demonstrated that lack of engagement breeds an environment that counteracts a conservation ethos, as citizens defend their spaces for survival. The research findings can supply a baseline of information for the formulation of city by-laws and national policies on urban water and household food security.

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