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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Carbon sink reforestation projects : a community perspective from KwaZulu-Natal, South Africa.

Ramanand, Sarisha. January 2012 (has links)
Climate change has exacerbated environmental degradation processes, causing an imbalance in the natural concentrations in atmospheric greenhouse gases. This has resulted in a myriad of socio–economic effects which have focused global attention on methodologies to reduce these effects, such as carbon sequestration. To achieve long term sustainability and success, community involvement in the technical and social aspects of carbon sequestration projects is necessary and must be acknowledged. One such mitigation methodology which incorporates the ideals of community proactive participation is carbon sink reforestation projects. This study is based on a community perspective of a carbon sink reforestation project, carried out in KwaZulu-Natal, South Africa. The study provides a holistic perspective of the concept of carbon sequestration drawing together technical aspects of carbon sequestration reforestation projects and the inclusion of the role of communities. The methodology comprised of questionnaires with industry experts and a local community, following a thematic data analysis. The current perception from industry is that the South African government lacks significant technology, capacity and finance to effectively manage national forest carbon sequestration regimes. Project participants expressed the view that these types of projects provided a sense of belonging and hope and articulated their gratitude for the environmental knowledge they gained from the project experience. Technical and social aspects of such projects such as carbon calculations and participatory rural appraisal techniques enhance a country’s ability for successful implementation of such projects. Findings reveal a need for technology, capacity building and finance; and the effects participation in these projects has on individuals. This is followed by recommendations and a ‘How To Guide’ developed by the researcher. This guide intends to enhance the collaboration of the technical aspects and involvement of communities throughout the project implementation process. Carbon regimes in this century will continue to grow in size and complexity. Stakeholder participation will be a strong factor in the success or failure of carbon sequestration reforestation projects. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
82

Spectral differentiation of Cannabis sativa L from maize using hyperspectral indices.

Sibandze, Phila. 31 October 2013 (has links)
Cannabis sativa L. is a drug producing crop that is illegally cultivated in South Africa. The South African Police Service (SAPS) use aerial spotters on low flying fixed wing aircrafts to identify cannabis from other land cover. Cannabis is usually intercropped with maize to conceal it from law enforcement officers. Therefore the use of remote sensing in identifying and monitoring cannabis when intercropped with maize and other crops is imperative. This study aimed to investigate the potential of hyper spectral indices to discriminate cannabis from maize under different cropping methods, namely, monocropped and intercropped. Cannabis and maize were grown in a greenhouse. The spectral signatures were measured in a dark room environment. Green pigments (chlorophyll and carotenoid) from the treatments were also measured. These pigments were then compared with their respective indices. Photosynthetic reflective index (PRI) and Carotenoid Reflective Index (CRI) were two of the indices used to discriminate cannabis from maize using carotenoid content while the Red Edge Position (REP) and the narrow band Normalized Difference Vegetation Index (NDVI) used chlorophyll content and morphological differences respectively to discriminate the two plant species. CRI and NDVI proved to be capable of identifying cannabis under the two cropping conditions. NDVI showed a 25% spectral over lap for the monocropped treatments and 60% over lap for the intercropped treatments. CRI displayed 18% and 58% over lap for the monocropped and intercropped treatments, respectively. As a result CRI emerged as the most suitable index for discriminating cannabis from maize. With proper calibration of airborne or space borne imagery, the study offers potential to detect cannabis using remote sensing technology. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.
83

Modelling the likelihood of wetland occurrence in KwaZulu-Natal, South Africa : a Bayesian approach.

Hiestermann, Jens. 05 September 2014 (has links)
Global trends of transformation and loss of wetlands to other land uses has deleterious effects on surrounding ecosystems, and there is a resultant increasing need for improved mapping of wetlands. This is because wetland conservation and management depends on accurate spatial representation of these systems. Current approaches to mapping wetlands through the classification of satellite imagery typically under-represent actual wetland area, and the importance of ancillary data in improving the accuracy in mapping wetlands is recognized. This study uses likelihood estimates of wetland occurrence in KwaZulu-Natal (KZN), South Africa, using a number of environmental surrogate predictors (such as slope, rainfall, soil properties etc.). Using statistical information from a set of mutually independent environmental variables in known wetland areas, conditional probabilities were derived through a Bayesian network (BN) from which a raster layer of wetland probability was created. The layer represents the likelihood of wetlands occurring in a specific area according to the statistical conditional probability of the wetland determinants. Probability values of 80% and greater also accounted for approximately 6% of the KZN area (5 520 km²), which is substantially more than the previously documented wetland area in KZN (4% of the KZN area or 4 200 km²). Using an independent test dataset, Receiver Operating Characteristic (ROC) curves with the Area Under Curve (AUC) analysis verified that the final model output predicted wetland area well (AUC 0.853). Based on visual comparisons between the probability layer and ground verified wetland systems, it was shown that high wetland probability areas in the final output correlated well with previously highlighted major wetland and wetland-rich areas in KZN. Assessment of the final probability values indicated that the higher the probability values, the higher the accuracy in predicting wetland occurrence in a landscape setting, irrespective of the wetland area. It was concluded that the layer derived from predictor layers in a BN has the potential to improve the accuracy of the KZN wetland layer by serving as valuable ancillary data. Application of the final probability layer could extend into the development of updated spatial freshwater conservation plans, potentially predicting the historical wetland extents, and as input into the land cover classification process. Keywords: ancillary data, Bayesian network, GIS, modelling, probability, wetland mapping. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2014.
84

Aspects of the weathering of the Clarens formation in the KwaZulu/Natal Drakensberg : implications for the preservation of indigenous rock art.

Meiklejohn, Keith Ian. 06 October 2014 (has links)
Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 1994.
85

A 40,000-year record of vegetation and fire history from the Tate Vondo region, Northeastern Southpansberg, South Africa.

Baboolal, Deeva Lata. 30 June 2014 (has links)
Records from the Quaternary period are used to confirm possible inferred climatic changes, reveal the responses of species to these changes, and serve as an archive against which modern environmental dynamics can be assessed. Fueled by a need to understand current climatic changes, the call for palaeoclimatic research in the southern African subregion has become more compelling. In southern Africa, such research has been largely restricted to springs and swamps as the subregion lacks natural lakes, with some exception of a few coastal lakes such as Lake Sibaya and Lake Eteza. Due to the arid and semi-arid landscapes which prevail in southern Africa, there is a paucity of suitable sedimentary deposits in the region. The highly organic peat deposit of Mutale Wetland, situated in the Tate Vondo region of the northeastern Soutpansberg presents an ideal opportunity for conducting palaeoenvironmental research. The Mutale Wetland contains relatively old sediments dating back to >30,000 cal years BP, placing this record within the late Quaternary period. Palaeoenvironmental techniques including radiocarbon, pollen and charcoal analyses were applied to produce a palaeoenvironmental reconstruction for Tate Vondo. A 302 cm sedimentary core was extracted from the Mutale Wetland. Detailed analyses show that prior to ca. 34,000 cal yr BP, conditions were fairly warm and dry. This is inferred from a dominance of open grassland vegetation. An expansion of Podocarpus forests together with an increase in fynbos elements suggest a shift to cool, subhumid conditions during the LGM. Cooler conditions persisted until ca. 12,000 cal yr BP. Thereafter, a climatic amelioration was experienced. The appearance of low charcoal concentrations throughout the late Pleistocene suggests that fire was infrequent. Between ca. 4000 – 1500 cal yr BP, conditions became warmer and drier, inferred from the development of arid savanna vegetation. The sharp increase in charcoal after ca. 4000 cal yr BP, broadly coinciding with the arrival of the first agriculturalists in the area, has implications for the history of human occupation in the Soutpansberg rather than shifts in climate. The succession from savanna to fynbos vegetation together with expanded forests implies a return to cool and moist conditions from ca. 1500 – 400 cal yr BP. Arid savanna persists from ca. 400 to the present, implying warmer and drier conditions towards the present day. Furthermore, from ca. 400 cal yr BP, the pollen and charcoal record indicate that the majority of recent changes in vegetation have been driven by anthropogenic activity. This record has contributed to an improved understanding of late Quaternary changes in climate, vegetation history and human impact in the northeastern Soutpansberg. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2014.
86

Land cover classification in a heterogeneous environment : testing the perfomance of multispectral remote sensing data and the random forest ensemble algorithm.

Ndyamboti, Kuhle Siseko. 06 June 2014 (has links)
Land use/land cover (LULC) information is essential for a plethora of applications including environmental monitoring and natural resource management. Traditionally, field surveying techniques were the sole source of acquiring such information; however, these methods are labour intensive, costly and time consuming. With the advent of remote sensing, LULC information can be acquired in an economical, less tedious and non-time consuming manner at shorter temporal cycles and over larger areas. The aim of this study was to assess the utility of multispectral remote sensing data and the Random Forest (RF) algorithm to improve accuracy of LULC maps in heterogeneous ecosystems. The first part of this study used moderate resolution SPOT-5 data to compare the performance of the RF algorithm to that of the commonly used Maximum Likelihood (ML) classifier. Results indicated that RF performed significantly better than ML (66.1%) and yielded an overall accuracy of 80.2%. Moreover, RF variable importance measures were able to provide an insight on the bands that played a pivotal role in the classification process. Due to the fact that moderate resolution satellite data was used, both classifiers seemed to experience some difficulties in discriminating amongst classes that exhibited similar spectral responses such as Eucalyptus grandis and Pinus tree plantations, young sugarcane and mature sugarcane, as well as river and ocean water. In that regard, the next section attempted to address this shortfall. The second part of the study used high resolution multispectral data acquired from the WorldView-2 sensor to discriminate amongst six spectrally similar LULC classes using the advanced RF algorithm. Results suggested that the use of WorldView-2 data together with the RF ensemble algorithm is a robust and accurate method for separating classes exhibiting similar spectral responses. The classification process yielded an overall accuracy of 91.23% and also provided valuable insight into WorldView-2 bands that were most suitable for discriminating the LULC categories. Overall, the study concluded that: (i) multispectral remote sensing data is an effective tool for obtaining accurate and timely LULC information, (ii) moderate resolution multispectral data can be used to map broad LULC categories whereas high resolution multispectral data can be used to separate LULC at finer levels of detail, (iii) RF is a robust and effective tool for producing LULC maps that are less prone to error. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.
87

Evaluating the potential of WorldView-2's strategically located bands in mapping the Bracken fern (Pteridium aquilinum (L.) Kuhn)

Ngubane, Zinhle Cynthia. 06 June 2014 (has links)
An understanding of the distribution of the Bracken fern (Pteridium aquilinum (L.) Kuhn) is critical for providing an appropriate management strategy. In this regard, remote sensing can play a critical role in mapping and modelling such distribution. In this study, an integrated approach using the random forest, maximum likelihood and vegetation indices was developed and tested to determine the capability of WorldView-2 multispectral eight band image in characterising the Bracken fern. Results based on the WorldView-2 were further compared to SPOT-5 multispectral (MS) image findings. The WorldView-2 (WV-2) image was spectrally resized to four traditional bands (blue, 450-510nm; green, 510-580 nm; red, 630-690 nm and NIR1, 770-895 nm) and four additional bands (coastal blue, 400-450 nm; yellow, 585-625 nm; red-edge, 705-745 nm and NIR2, 860-1040 nm) to evaluate the practicality of the spectral resolution in mapping the Bracken fern. The results from this analysis showed that the spectrally resized additional bands were more successful in general land cover mapping and characterising the Bracken fern. The result’s overall accuracy was 79.14% while the user’s and producer’s accuracies were 97.62% and 91.11% respectively. The second part of the study sought to improve the classification accuracy by applying a robust machine learning algorithm, the random forest. Since the random forest does not automatically choose the optimal bands, the backward variable elimination technique was employed to identify the optimum wavelengths in WV-2 for the identification of the Bracken fern. Respective out-of-bag (OOB) errors of 13.1% and 9.17% were achieved when the WV-2’s eight bands and optimally selected bands (n= 5) were used. These bands lie in the green (510-580nm), near-infrared1 (770-895nm), red-edge (705-745nm), near-infrared2 (860-1040nm) and the coastal blue (400-450nm) regions of the electromagnetic spectrum. These findings confirm the importance of the additional bands in vegetation analyses. The vegetation indices computed from these regions of the spectrum were superior to those in the visible region. The classification accuracy using WV-2 bands was superior to that from the commonly used SPOT 5 image. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2014.
88

The provision of services in rural areas with special reference to health and education : a case study of Okhombe village in the North-West Drakensberg, KwaZulu-Natal.

Sookraj, Anand. January 2002 (has links)
This study is an examination of services in previously disadvantaged rural areas of South Africa with special reference to health and education. The case study approach was used in this study and Okhombe Ward of the Amazizi area in Northern Kwazulu-Natal was selected for this research project. The purpose of the study was firstly to determine the socio-economic profile of the people in Okhombe. Secondly, the study intended to identify whether services that enhance well-being are available in the Okhombe. Thirdly, the study aimed at assessing the quality and adequacy of the services that are available. Fourthly, the study aimed at ascertaining the concerns, problems and needs of people. Fifthly, the study intended to establish whether power dynamics compete with each other in the acquisition and accessibility of services and; lastly to forward recommendations based on findings from this research. The research found that the people were happy with the manner in which decisions were taken regarding the village. Meetings are called up at the community hall and every household is invited. There is consultation and negotiation with the people. This study found that, the health needs of the people are being catered for by the many traditional healers in the area and a mobile clinic that visits the Okhombe Ward on two Wednesdays a month. The main clinic that services the Okhombe Ward and entire Amazizi area is located some ten kilometers from Okhombe. There are no emergency and hospital services available in the area. While the people are happy with services of the many traditional healers in the area, they are not satisfied with the present health provisions by the Department of Health. It is recommended that a full tinle clinic be established in Okhombe to replace the mobile clinic and that provisions be made for hospital and emergency services in the Amazizi area. There is a primary and a high school that caters for the educational needs of the children. The high school lacks electricity, water supply and an administration building. The Principal and the heads of departments at the high school make use of space in the adjacent community hall. Both schools did not have their full complement of educators in January 2001. The primary school has electricity and a standpipe for water. Further, the schools did not have resources such as properly maintained sports fields, laboratories, libraries and good toilet and sanitation facilities. There also was a shortage of desks and chairs at both schools. The Okhombe community places great stress on education and this is borne by the fact that they would like both boys and girls to be educated. They would like a skills training centre for school leaving children to be established in the area. The people believe that education and skills training would enable the youth to secure employment in the competitive labour market. The community also wants Adult Basic Education to be reintroduced in the area. The Department of Education must provide the necessary infrastructure in terms of furniture, administration buildings, ablution facilities, libraries and equipped specialist rooms. It must also provide a full complement of educators for the schools at the beginning of each year in order that the schools function at an optimal level. Schools must offer subjects like woodwork, agricultural science, metalwork, computer studies, etc. that will help prepare youth for later employment. To this end schools must be equipped with the necessary workshops, specialist rooms and qualified educators. A traditional hierarchical system exists in Okhombe. At the local level, the Induna is in charge. Above the Induna is the Chief. The chief is the most powerful person in the area under his control and all disputes are taken to the Chief's court. / Thesis (M.A.)-University of Durban-Westville, 2002.
89

Die klein Karoo

Vermeulen, D. C. January 1940 (has links)
Thesis (MA)--Universiteit van Stellenbosch, 1940. / No abstract available.
90

Applying GIS in the evaluation of landscape aesthetics

Fourie, Rene 04 1900 (has links)
Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2005. / Scenic beauty, or landscape aesthetics, should be regarded as a valuable resource, to be protected and enhanced in order to generate income. Current environmental impact assessment (EIA) studies do not include the evaluation of scenic beauty as a resource properly, due to the lack of effective evaluation methods. A general dilemma lies in objectively evaluating beauty. If scenic preferences can be associated consistently with the physical landscape features, the latter can be used as predictors of the former. Analysis of aesthetics can therefore be done with a degree of objectivity, based on these general preferences. A large number of these preferences are morphologically measurable. In other words, these preferences can be mapped in a Geographical Information System (GIS), rated, and evaluated quantitatively. The first step in objectively evaluating landscape aesthetics entailed identification and compilation from the literature of conceptual components in a landscape, i.e. the units defining a landscape. Four components were identified: landform, vegetation, water features and man-made features. Each of the four components can be subdivided into several elements. Secondly, scenic preferences that can be consistently associated with landscape features were identified. It was found that any subjective experience of landscape aesthetics would be either one of calmness or one of excitement. The presence or absence of the landscape elements, and specific combinations of elements and element variables within the context of an individual landscape, will determine the type and extent of the aesthetic experience of the viewer. Finally, this theory was put into practice. Coverages were created of a test region, with landscape elements as the features of the coverages, and element variables or characteristics as feature attributes. These landscape elements, as they enhance either calmness or excitement, were quantified by assigning value ratings to the elements according to the extent of the influence of the elements on the aesthetic value of the landscape. ArcInfo GRID functionality was used to convert the coverages to raster (or grid) overlays, using the element variables enhancing both calmness and excitement. A simple cumulative summing function was used to derive an aggregate Calm Aesthetic Experience map by adding grids enhancing calmness. An aggregate Exciting Aesthetic Experience map was constructed by adding grids enhancing excitement. Finally, these two grids were summed in order to construct a Total Aesthetic Experience map, which is an indication of the total aesthetic value of the test region. The outcome of this research was a method for analysis and objective evaluation of a landscape, using a GIS for data creation, analysis and map construction. The resultant map is an indication of aesthetic value, showing the test region graded according to intrinsic aesthetic value.

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