Doctoral Degrees (Geography)

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

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Mapping the spatial variability of foliar C:N ratio in a communal rangeland using remote sensing.
(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.
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.
Intertidal salt-marsh foraminifera as sea-level indicators : lessons from the South African coastline.
(2016) Strachan, Kate Leigh.; Hill, Trevor Raymond.; Finch, Jemma M.
Microfossils of the group foraminifera are widely used as robust, high-precision sea-level proxy indicators associated with salt marshes. These microfossils exhibit vertical zones related to elevation across the intertidal zone, and are well preserved within salt marsh sediments, leaving a permanent record of sealevel change. This research explores the application of intertidal salt-marsh foraminifera as sea-level indicators along the southern African coastline. It further describes the development of a regional transfer function and assesses its performance in reconstructing sea-level change. Three permanently open estuarine environments were selected for this study, Kariega and Keiskamma along the eastern coastline, and Knysna along the southern coastline. Foraminiferal sea-level records depend on the accurate characterisation of modern foraminiferaenvironment relationships and salt-marsh zonation representative of a study site. Contemporary foraminiferal assemblages were surveyed across the intertidal zone, and corresponding vegetation and environmental data (pH, salinity, soil properties and elevation) were collected. Multivariate ordination was used to examine the correlation between living foraminiferal assemblages and environmental parameters. It was established that elevation was the key environmental variable governing the distribution of salt-marsh foraminifera at the Keiskamma and Knysna estuaries. Salinity had a significant but opposite influence to elevation at the Keiskamma Estuary. At Knysna Estuary, pH was the secondary driver of foraminiferal composition. The contemporary intertidal environments at Keiskamma and Knysna estuaries were described in relation to the zonation of foraminifera across each salt marsh. Cluster analysis was performed to separate foraminifera into salt-marsh zones. Whilst the composition and vertical ranges of assemblage zones vary between sites, we suggest that South African salt marshes can be classified according to four broad subdivisions. The mudflats have the most diverse assemblages, consisting predominately of calcareous species. Ammonia spp., dominates the lower marsh zone followed by Miliammina fusca, which dominates the middle- to lower marsh vegetated zone. The high marsh zone is characterized by the high abundance of Trochammina inflata. Modern training datasets from the selected study sites were used to investigate the suitability of local versus regional datasets for reconstructing recent sea-level trends. The results suggest that a regional transfer function using weighted averaging models is suitable for the analysis of fossil material, producing sea-level reconstructions with an error of ±0.22 m. As a validation exercise the regional transfer function was applied to a sediment core from Kariega, and compare with tidal gauge data. Sea-level records from far field sites offer important constraints on the timing and amplitude of global sea-level changes and improve our understanding of the driving mechanisms behind the late Holocene sea-level change. The regional transfer function has the potential to link short-term instrumental records with longer-term relative sea-level reconstructions, advancing research into past sea-level fluctuations along the South African coastline, and provide a baseline understanding of the nature and causes of sea-level variation. Intertidal salt-marsh foraminifera provide South African sea-level studies with an indicator that is reliable and can be used at multiple sites, allowing for comparisons between studies.
Remote sensing of wetland tree species in the iSimangaliso Wetland Park, KwaZulu-Natal, South Africa.
(2016) van Deventer, Heidi.; Mutanga, Onisimo.; Cho, Moses Azong.
The impact of global change is expected to result in changes in the distribution and composition of species. Coastal swamp and mangrove forests are some of the most threatened forest types in the world. Remote sensing is a suitable tool for monitoring species distribution and varying condition because of its spatial extent and repeatability. The ability of remote sensing to separate between species can be attributed primarily to its capability to quantify the absorption features in the electromagnetic spectrum which relate to plant biochemical and biophysical properties such as pigments, nutrients (proteins and starch), leaf water content, leaf angle distribution, leaf area index and foliage biomass. For some species, these phenological variations are extreme, as in the case of deciduous tree species, thus enhancing the ability to differentiate between species, whereas others are less pronounced, such as with evergreen tree species, making spectral distinction between species much more challenging. Few studies have assessed the pigment and nutrient phenology of evergreen tree species in subtropical forested wetlands, let alone their spectral differences. This study assesses whether multi-season data across a number of phenological phases of evergreen wetland tree species will improve their classification accuracy when compared to a single season and single phenological event. The objectives were to (i) assess whether tree species had unique seasonal profiles of foliar biochemicals; (ii) ascertain the spectral bands of plant properties which remain important across phenological phases for species classification; (iii) determine whether leaf reflectance spectra from multiple seasons would improve species classification when compared to a single season; and (iv) whether multi-season imagery would improve species discrimination when compared to a single season. Thus, the study made use of leaf level and canopy level spectra collected using a handheld spectrometer and spaceborne RapidEye imagery, respectively. Six dominant evergreen tree species from forested wetlands in the subtropical region of KwaZulu-Natal, South Africa, were sampled across four seasons (winter, spring, summer and autumn). Differences in foliar biochemical concentration were assessed for two pigments, including carotenoids and chlorophylls, as well as two nutrients, nitrogen and phosphorous. The results showed that the majority of species had no significant changes in foliar pigments across the four seasons. Foliar nitrogen showed a significantly higher variability in the spring, summer and autumn seasons compared to the winter, whereas foliar phosphorus also varied across the seasons but to a lesser degree. The highest percentage of species pairs was separable using foliar nitrogen, compared to the pigments and phosphorus, emphasizing the importance of nutrients such as leaf proteins for species discrimination. The study found a changing relationship between leaf spectra and foliar nutrient concentration across the four seasons for the six evergreen tree species. Twenty-two spectral bands which are related to known absorption features of plant properties were identified across the four seasons as important for tree species discrimination. The relationship between leaf spectra and foliar nitrogen was highest during the spring, summer and autumn seasons for narrow bands associated with absorption features of proteins compared to the red-edge region. The spectra band combination 2130 nm and 2240 nm yielded the highest coefficient of determination between leaf spectra and foliar nitrogen across three of the four seasons. Season-specific prediction models were found to be more accurate in predicting foliar nitrogen than prediction models from across all seasons. The twenty-two bands were effective for the data reduction of the hyperspectral data and yielded a similar overall accuracy compared to 421 bands. Multi-seasonal data improved tree species classification for multispectral sensors with a few bands. The classification, in which multi-season leaf spectra or canopy data from RapidEye imagery was used, resulted in higher overall and user’s accuracies when compared to the single-season classifications. In contrast, the use of multi-season data for the classification of leaf spectra with 22 narrow bands, showed no statistical significance of differences compared to the classification results of the single season in which the highest overall accuracy of all single seasons had been obtained. The value of an increased classification accuracy should however be measured against the increase of cost when using images from multiple seasons. The study concludes that although seasonal profiles of foliar biochemicals overlap, multi-season information do improve species discrimination at foliar biochemical, leaf-spectra and canopy-spectra levels.
An analysis of the impacts of human activities and management strategies on wetland processes in southern Zimbabwe.
(2015) Marambanyika, Thomas.; Beckedahl, Heinrich Reinhard.
Wetlands are one of the most productive ecosystems in the world, as they provide benefits to humans and the environment. Despite their value, wetlands are being degraded at an unprecedented rate. Whilst explanations have been sought from natural and human perspectives, the debate surrounding wetland loss continues, and wetland loss remains a problem, especially in developing countries. A number of strategies on wetland use and management have been developed and implemented at various scales in response to wetland degradation and loss, although spatio-temporal variations were noted, as were varying levels of success, shown to be influenced by differences in existing land use, institutional structures and wetland hydrogeomorphic types. Whilst several studies focusing on specific facets of wetlands have been conducted in Zimbabwe, so far none have been carried out to document the impacts of various land uses and management strategies on wetland conditions. The present study therefore assessed the spatio-temporal impacts of human activities and related management strategies on wetland processes in six wetlands located in three rural districts in the southern part of Zimbabwe so as to address this knowledge deficit. To achieve the objectives of the study, changing land use patterns in wetlands were assessed for the period between 1985 and 2013 from aerial photographs and RapidEye images; and the benefits derived by surrounding communities determined, complemented by information obtained from household surveys with 123 respondents. Results show that there was no major change in land use as cultivation dominated throughout and increased by only 7.7% between 1985 and 2013. This result prompted the need to assess the impact of cultivation on wetland biophysical conditions (hydrology, geomorphology and vegetation) using the WET-Health framework. Results show that not all, but some cultivation methods negatively affected the present hydrological state of the wetlands. It was observed that broad ridges and broad furrows and concrete canals were largely responsible for drying. Vegetation structure and composition has been seriously modified by cultivation as evident in invasion by non-wetland species. In order to understand how management strategies influenced use and conservation of wetlands, the study used stakeholders’ perceptions to investigate the effectiveness of existing institutional arrangements in regulating wetland protection. The results show that the degree of wetland protection depends on the number, frequency and relations of institutions operating at each site. Although government departments, traditional leaders, wetland committees and non-governmental organizations participated, generally there was no uniformity in the existing institutional structures at each wetland. Conflicts and discord were sometimes apparent between institutions due to divergent institutional mandates torn between socio-economic and environmental considerations. Traditional leaders and wetland committees were present at each site and where they were effectively involved, wetlands were better conserved as shown by their ecological conditions with little evidence of soil erosion and hydrological alterations as in the case of Chebvuterambatemwa, Dufuya, Madigane and Tugwi. The study further investigated the gap between policy and practice, especially in light of the new legal dispensation which encourage wise use of wetlands, dating back to 2003. The results show that most of the people (61.8%) were not aware of national wetland law; hence there was a disjuncture between legal provisions and practical implementation resulting in little impact on wetland conservation. Poor implementation of national wetland law may be ascribed to a number of socio-economic factors and institutional challenges. The results of the study further showed that in better conserved wetlands, such as Chebvuterambatemwa, Dufuya and Tugwi, effective soil and water conservation measures were in place and their implementation was effectively monitored by local institutions. Food security of most households adjacent to these wetlands was stable. Overall, the findings of this study highlighted the importance of understanding the effects of cultivation and related institutional arrangements and policy frameworks on wetland conservation. The study demonstrates the need to adopt a holistic, people-centered approach in wetland management that also considers the environment. The results further provide insights for Zimbabwe to shift towards an integrated approach, to facilitate effective and sustainable utilization of wetlands. It is in this context that this research provides baseline information that can be utilized in the formulation of wetland resources management frameworks based on an understanding of the interaction between anthropogenic, socio-economic and ecological processes.

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