Doctoral Degrees (Geography)

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The use of spatial analysis and participatory approaches in strategic environmental assessment (SEA) : identifying and predicting the ecological impacts of development on the KwaZulu-Natal North Coast of South Africa.
(2010) Ahmed, Fathima.; Bob, Urmilla.; Ahmed, Fethi B.
The high pressures for coastal development, translated as prolific land cover transformation, coupled with the weaknesses of management to protect the environment has led to the gradual deterioration of environmental conditions in many coastal areas. Land use decisions in coastal areas are based on opportunities and constraints affected by both biophysical and socio-economic drivers, and hence present one of the main issues integrating the large debate on sustainable development in coastal zones (Lourenço and Machado, 2007: 1). The aim of this study is to investigate the effectiveness of the integration of spatial analysis and participatory approaches in SEA (particularly its ability to identify and predict ecological impacts) on the KwaZulu-Natal north coast of South Africa. The study adopted a conceptual framework based on landscape ecology, which was underpinned within the overarching political ecology framework. The former underscores the importance of integration, while the latter critiques the institutionalization of environmental concerns, which are characterized by inequalities in terms of social and political power and of how problems are defined, mediated and resolved. Hence this conceptual framework was considered appropriate to assess the strategic environmental issues pertaining to the coastal zone on the KwaZulu-Natal north coast. The researcher used participatory methods, primarily focus group discussions (which included venn diagramming, ranking exercises and participatory mapping) which were triangulated with both quantitative and qualitative methods as part of an integrated impact assessment. These relate to the use of semistructured questionnaires which were administered to a purposive sample of six key stakeholder interest groups within the study area. A spatial GIS time series analysis of land use and cover change was employed to determine baseline conditions, changes in the state of key ecosystems, key development drivers and emerging threats. Additionally, a policy and institutional review was undertaken. The analysis revealed that major natural land cover classes are in decline in the study area,within a time period of less than 10 years. The most sensitive ecosystems were found to be grasslands (-19.99%), coastal forest (-40%), wetlands (-37.49%) and secondary dunes (- 21.44%). Furthermore, agriculture and forestry are also indicating severe declines. The reasons attributed to this transformation of land cover are increasingly being linked with economic motives such as individual private land-owner dynamics, tourism growth and development in the area. Furthermore, the policy agendas are clearly economically motivated. These losses signify the cumulative decline in ecosystem goods and services, and could undermine pose risks to the society that relies on them either directly or indirectly. One of the main considerations in this research endeavor was to formulate a Strategic Environmental Assessment (SEA) Framework to inform future ICZM in the study area. SEA is planning with a long-term perspective, with a focus on a spatial rather than a project level, an element that is clearly lacking in the current development scenario of this coastline. It is critical that the SEA Framework advocated in this study include a range of variables that will permit short-term, medium-term and long-term monitoring and evaluation aimed at ensuring sustainable planning in the area.
Globalisation, development and community-based tourism in developing countries : a case study of Pondonland, Eastern Cape.
(2010) Giampiccoli, Andrea.; Moodley, Vadivelu.; Brooks, Shirley.
Contemporary globalisation in developing countries is circumscribed by neo-liberal development approaches, while community-based development seeks to create alternative development strategies. This thesis brings together research in tourism with theoretical perspectives from Gramscian social analysis in order to explore contemporary conflict between these two strategies in the tourism sector. The purpose is to investigate the influence the hegemonic global milieu has exerted on an alternative community-based tourism (CBT) strategy that was initially formally/institutionally supported. Concepts of hegemony, globalisation and divergence/convergence, together with development theories, are explored and applied to the international tourism sector and CBT in particular. A theoretical structure is proposed in which the relationships between hegemony, globalisation, and processes of divergence/convergence are explicated in relation to the tourism sector, and CBT in particular. Global-local linkages, conceptualised in terms of the theoretical framework, are explored in a particular geographical context, namely the Pondoland coast of South Africa. South Africa has recently rejoined the global socio-economic milieu after the isolation of the apartheid period and a European Union-supported tourism project in the Pondoland region is studied in detail. The case study serves to empirically substantiate the proposed theoretical framework. The investigation contributes to ‘initiate’ a global – local oriented paradigm in tourism study that focuses on the relationship between globalisation processes and a CBT development approach by exploiting and conjoining the correlation of the concepts of the proposed theoretical framework. Globalisation processes are set against a specific and local form of tourism, i.e. community-based tourism. The proposition is a ‘new’ double level of interlinkage. General and global policies are interlinked and cross each other with specific and local policies to evaluate a CBT project outcome. The study intends to go beyond existing literature of CBT management and project development. This is achieved by providing an investigation on the ‘unseen’ working mechanisms and influence of globalisation processes in relation to a specific CBT local project supported by a global actor in international cooperation, thus verifying interpretations and commitment on CBT development approaches. The case study findings elucidate and highlight the final effects of the theoretical proposition at a practical level by clarifying and showing the level of influence on, and re-adjustment of, the case study end result in comparison with its initial plan. A shift in the case study project development is individuated and commented on in relation to the proposed theoretical framework. The investigation results allow validating the proposed conceptual basis of the study. Based on the findings, this thesis a proposal is made to construct the interrelationship between development and CBT understanding. A typology and specific nomenclature of CBT approaches is advanced together with their correlation to development concepts. The conclusion also gives further general and specific recommendations by providing possible strategies to permit proper development and better exploitation of CBT possibilities.
Remote sensing of forest health : the detection and mapping of Pinus patula trees infested by Sirex noctilio.
(2008) Ismail, Riyad Abdool Hak.; Mutanga, Onisimo.; Bob, Urmilla.
Sirex noctilio is causing considerable mortality in commercial pine forests in KwaZulu- Natal, South Africa. The ability to remotely detect S. noctilio infestations remains crucial for monitoring the spread of the wasp and for the effective deployment of suppression activities. This thesis advocates the development of techniques based on remote sensing technology to accurately detect and map S. noctilio infestations. To date, no research has examined the potential of remote sensing technologies for the detection and mapping of Pinus patula trees infested by S. noctilio. In the first part of this thesis, the focus was on whether high spatial resolution imagery could characterize S. noctilio induced stress in P. patula forests. Results showed that, the normalized difference vegetation index derived from high spatial resolution imagery has the potential to accurately detect and map the later stages of S. noctilio infestations. Additionally, operational guidelines for the optimal spatial resolutions that are suitable for detecting and mapping varying levels of sustained S. noctilio mortality were defined. Results showed that a pixel size of 2.3 m is recommended to detect high (11-15%) infestation levels, and a pixel size of 1.75 m is recommended for detecting low to medium infestation levels (1-10%). In the second part of this thesis, the focus was on the ability of high spectral resolution (hyperspectral) data to discriminate between healthy trees and the early stages of S. noctilio infestation. Results showed that specific wavelengths located in the visible and near infrared region have the greatest potential for discriminating between healthy trees and the early stages of S. noctilio infestation. The researcher also evaluated the robustness and accuracy of various machine learning algorithms in identifying spectral parameters that allowed for the successful detection of S. noctilio infestations. Results showed that the random forest algorithm simplified the process by identifying the minimum number of spectral parameters that provided the best overall accuracies. In the final part of this thesis spatial modelling techniques were used to proactively identify pine forests that are highly susceptible to S. noctilio infestations. For the first time the random forest algorithm was used in conjunction with geographic information systems for mapping pine forests that are susceptible to S. noctilio infestations. Overall, there is a high probability of S. noctilio infestation for the majority (63%) of pine forest plantations located in Mpumalanga, South Africa. Compared to previous studies, the random forest model identified highly susceptible pine forests at a more regional scale and provided an understanding of localized variations of environmental conditions in relation to the distribution of the wasps.
The estimation of Eucalyptus plantation forest structural attributes using medium and high spatial resolution satellite imagery.
(2008) Gebreslasie, Michael Teweldemedhin.; Ahmed, Fethi B.; van Aardt, Jan.
Sustaining the socioeconomic and ecological benefits of South African plantation forests is challenging. A more systematic and rapid forest inventory system is required by forest managers. This study investigates the utility of medium (ASTER 15 m) and high (IKONOS 1-4 m) spatial resolution satellite imageries in an effort to improve the remote capture of structural attributes of even-aged Eucalyptus plantations grown in the warm temperate climatic zone of southern KwaZulu-Natal, South Africa. The conversion of image data to surface reflectance is a pre-requisite for the establishment of relationships between satellite remote sensing data and ground collected forest structural data. In this study image-based atmospheric correction methods applied on ASTER and IKONOS imagery were evaluated for the purpose of retrieving surface reflectance of plantation forests. Multiple linear regression and canonical correlation analyses were used to develop models for the prediction of plantation forest structural attributes from ASTER data. Artificial neural networks and multiple linear regression were also used to develop models for the assessment of plantation forests structural attributes from IKONOS data. The plantation forest structural attributes considered in this study included: stems per hectare, diameter at breast height, mean tree height, basal area, and volume. In addition, location based stems per hectare were determined using high spatial resolution panchromatic IKONOS data where variable and fixed window sizes of local maxima were employed. The image-based dark object subtraction (DOS) model was better suited for atmospheric correction of ASTER and IKONOS imagery of the study area. The medium spatial resolution data were not amenable to estimating even-aged Eucalyptus forest structural attributes. It is still encouraging that up to 64 % of variation could be explained by using medium spatial resolution data. The results from high spatial resolution data showed a promising result where the ARMSE% values obtained for stems per hectare, diameter at breast height, tree height, basal area and volume are 7.9, 5.1, 5.8, 8.7 and 8.7, respectively. Results such as these bode well for the application of high spatial resolution imagery to forest structural assessment. The results from the location based estimation of stems per hectare illustrated that a variable window size approach developed in this study is highly accurate. The overall accuracy using a variable window size was 85% (RMSE of 189 trees per hectare). The overall findings presented in this study are encouraging and show that high spatial resolution imagery was successful in predicting even-aged Eucalyptus forest structural attributes in the warm temperate climates of South Africa, with acceptable accuracy.
Communities' perceptions and assessment of biodiversity conservation strategies : the case of protected areas in Kenya.
(2010) Makindi, Stanley Maingi.; Bob, Urmilla.
Protected areas in Kenya constitute 7% of the total land area with over 75% of wildlife in the country being found on private or communal land. Wi th one of the highest population growth rates in the world and facing a range of developmen t issues with limited resources, one of the greatest challenges in Kenya is reconciling and sus taining economic development with biodiversity conservation and sharing the costs and benefits of conservation between individuals, state and the general community. The study was info rmed by the relevant literature and the researcher’s fieldwork which was conducted in 2008 in three categories of protected areas under different governance types and primary management o bjectives in Kenya (Lake Nakuru National Park – government managed, Kimana Community Wildlif e Sanctuary – communally managed, and Kedong Game Ranch – privately managed). The res earch examined the general issues of how local communities in Kenya have embraced differ ent biodiversity conservation strategies. A major emphasis was on identifying those factors inf luencing their attitudes towards conservation approaches and their participation in conservation management institutions. At issue was whether support for a particular conservation strat egy is primarily a function of communities’ experiences with biodiversity decline or their rela tionship with the conservation authorities. The research employed both qualitative and quantitative techniques in gathering the data. A total of 270 community respondents and 45 staff respondents were interviewed. Several demographic and socio-economic characteristics of the local peo ple that include age, gender, educational level and location, amongst others, were found to signifi cantly influence the attitudes of the local people towards the protected areas conservation act ivities. The direction of the influences (whether positive or negative) depended on the mana gement category of the particular protected area. The general findings of the study suggest tha t although local people appreciate the crucial value of biodiversity and the role of protected are as in conserving it, there is some evidence of resentment towards some management activities of th e protected area regulators. Negative attitudes were attributed to perceived problems of living next to the protected areas such as lack of involvement of the local people in the managemen t of the protected areas, restrictive access to and use of resources from the protected areas, hara ssment by the conservation enforcing agents, conflicts with wildlife and lack of compensation fo r damages and losses incurred. Widespread support for the management activities was associate d with perceived benefits to the local populations such as support for educational program mes, social amenities, employment and business opportunities. It is clear from this study that different rationales of conserving biodiversity need to address the issue of protected area management in the context of sustainable development through a combination of conservation s trategies.
Mechanical weathering in cold regions with special emphasis on the Antarctic environment and the freeze-thaw mechanism in particular.
(2003) Hall, Kevin John.
Consideration of almost any geomorphology textbook will show the fundamental argument that in cold environments mechanical weathering processes, usually freeze-thaw, will predominate and that chemical weathering will be temperature-limited, often to the point of non occurrence. These basic concepts have underpinned geomorphology for over a century and are the basis for the development of many landforms in periglacial regions. With the introduction of data loggers so field data became more readily available but, sadly, those data were not of a quality to other than justify the existent assumptions and thus did little more than reinforce, rather than test, the nature of our understanding of cold region weathering. Factors such as rock properties were dealt with to a limited extent but rock moisture was all but ignored, despite its centrality to most weathering processes. Here the results of field studies into weathering in cold regions, coupled with laboratory experiments based on the field data, are presented. An attempt is made to overcome the shortcomings of earlier studies. Temperature, moisture and rock properties have all been considered. Processes were not assumed but rather the data were used to evaluate what processes were operative. The results, both in terms of weathering process understanding per se and of its application to landform development, significantly challenge our longheld perceptions. Information is presented that shows that it is not temperature, but rather water, that is the limiting factor in cold region weathering. Indeed, in the absence of water, many cold environments have attributes akin to a hot desert. The relevance of this is that weathering processes other than freeze-thaw may play a significant role and that in the presence of water chemical weathering can play a far greater role than hitherto thought. Overall, the whole concept of zonality with respect to weathering is questioned. Finally, the attributes of weathering are put within the context of landform development and questions raised regarding the origin of some forms and of their palaeoenvironmental significance. Attributes of periglacial, glacial and zoogeomorphic processes and landforms in present and past cold environments are also presented.
The remote sensing of papyrus vegetation (Cyperus papyrus L.) in swamp wetlands of South Africa.
(2010) Adam, Elhadi Mohammed I.; Mutanga, Onisimo.
Papyrus (Cyperus papyrus .L) swamp is the most species rich habitat that play vital hydrological, ecological, and economic roles in central tropical and western African wetlands. However, the existence of papyrus vegetation is endangered due to intensification of agricultural use and human encroachment. Techniques for modelling the distribution of papyrus swamps, quantity and quality are therefore critical for the rapid assessment and proactive management of papyrus vegetation. In this regard, remote sensing techniques provide rapid, potentially cheap, and relatively accurate strategies to accomplish this task. This study advocates the development of techniques based on hyperspectral remote sensing technology to accurately map and predict biomass of papyrus vegetation in a high mixed species environment of St Lucia- South Africa which has been overlooked in scientific research. Our approach was to investigate the potential of hyperspectral remote sensing at two levels of investigation: field level and airborne platform level. First, the study provides an overview of the current use of both multispectral and hyperspectral remote sensing techniques in mapping the quantity and the quality of wetland vegetation as well as the challenges and the need for further research. Second, the study explores whether papyrus can be discriminated from each one of its coexistence species (binary class). Our results showed that, at full canopy cover, papyrus vegetation can be accurately discriminated from its entire co-existing species using a new hierarchical method based on three integrated analysis levels and field spectrometry under natural field conditions. These positive results prompted the need to test the use of canopy hyperspectral data resampled to HYMAP resolution and two machine learning algorithms in identifying key spectral bands that allowed for better discrimination among papyrus and other co-existing species (n = 3) (multi-class classification). Results showed that the random forest algorithm (RF) simplified the process by identifying the minimum number of spectral bands that provided the best overall accuracies. Narrow band NDVI and SR-based vegetation indices calculated from hyperspectral data as well as some vegetation indices published in literature were investigated to test their potential in improving the classification accuracy of wetland plant species. The study also evaluated the robustness and reliability of RF as a variables selection method and as a classification algorithm in identifying key spectral bands that allowed for the successful classification of wetland species. Third, the focus was to upscale the results of field spectroscopy analysis to airborne hyperspectral sensor (AISA eagle) to discriminate papyrus and it co-existing species. The results indicated that specific wavelengths located in the visible, red-edge, and near-infrared region of the electromagnetic spectrum have the highest potential of discriminating papyrus from the other species. Finally, the study explored the ability of narrow NDVI-based vegetation indices calculated from hyperspectral data in predicting the green above ground biomass of papyrus. The results demonstrated that papyrus biomass can be modelled with relatively low error of estimates using a non-linear RF regression algorithm. This provided a basis for the algorithm to be used in mapping wetland biomass in highly complex environments. Overall, the study has demonstrated the potential of remote sensing techniques in discriminating papyrus swamps and its co-existing species as well as in predicting biomass. Compared to previous studies, the RF model applied in this study has proved to be a robust, accurate, and simple new method for variables selection, classification, and modelling of hyperspectral data. The results are important for establishing a baseline of the species distributions in South African swamp wetlands for future monitoring and control efforts.
The role of tourism in natural resource management in the Okavango Delta, Botswana.
(2006) Harrison, Phillipa Anne.; Maharaj, Bridgemohan.
In recent years the use of tourism as a development strategy by Third World governments has increased, resulting in the intersection of international tourism and local resource utilisation patterns. The aim of this thesis is to critically assess the impact of tourism in the utilisation and management of natural resources in the Okavango Delta in Botswana. More specifically, the study appraises the current state of tourism and natural resource utilisation and management in the Okavango Delta; assesses the past and present forms of resource utilisation practised by the local inhabitants scattered throughout the Delta area; focuses on the implementation of government policy regarding resource use; highlights past and present relationships between tourism and resource utilisation; and examines the impact of tourism on the areas resources, environment and local inhabitants. Research has shown that the Okavango Delta, which is Botswana's primary tourism area, is faced with a number of social, economic and environmental challenges. These include extreme levels of poverty, especially in the rural areas; lack of infrastructure; competition over land and resources; growing regional inequality; social degradation; increased imports leading to foreign exchange leakages; changes in subsistence strategies and increased 'rural-urban' .migration; and the loss of control of the region by the local population to the global tourism system. The Okavango Delta is in the process of undergoing a change from traditional, rural, subsistence economies and livelihoods to capitalist, commercial-driven economic structures. In the Okavango Delta, as in many places around the world, people are in the process of being integrated into national level political, social and economic institutions, both within and outside of their control. The creation of employment for the local population, the sustainable use of the Delta and its resources, the development of the local agricultural industry, the continued growth of the tourism industry, and striking a balance between the conservation/preservation of the Okavango and meeting the water requirement needs of Angola, Namibia, and Botswana's growing populations are amongst the key concerns present in the area. 11 Tourism in the Okavango Delta is directly dependent upon the utilisation of the region's natural resources of wildlife, water and natural vegetation areas for the industry. As such, tourism has increasingly impacted upon the way, and degree to which, these resources are managed and utilised, hence being identified as a key factor effecting the resource sector. If the Government of Botswana is to develop a tourism industry which fosters environmental and natural resource preservation, rather than maintaining a heavy dependence on limited and fragile resources, a better understanding of the relationship between the two sectors is necessary. Enhancing the positive linkages between tourism and natural resource utilisation in the Okavango Delta region represents an important means to stimulate increased natural resource and environmental protection, and improve the distribution of tourism benefits to rural communities. amongst the key concerns present in the area. Tourism in the Okavango Delta is directly dependent upon the utilisation of the region's natural resources of wildlife, water and natural vegetation areas for the industry. As such, tourism has increasingly impacted upon the way, and degree to which, these resources are managed and utilised, hence being identified as a key factor effecting the resource sector. If the Government of Botswana is to develop a tourism industry which fosters environmental and natural resource preservation, rather than maintaining a heavy dependence on limited and fragile resources, a better understanding of the relationship between the two sectors is necessary. Enhancing the positive linkages between tourism and natural resource utilisation in the Okavango Delta region represents an important means to stimulate increased natural resource and environmental protection, and improve the distribution of tourism benefits to rural communities.
Management and regulation of rural land use : a model for traditional land tenure systems in KwaZulu-Natal.
(2000) Montgomery, Andrew David.; Slade, D. Graeme B.
South Africa is confronted by a number ofproblems which include: a high and rapidly increasing population, conditions of poverty, hunger, illiteracy, unemployment, and a degrade9 environment. These problems are associated with inappropriate land use and development and the unwise utilization of natural resources. This work investigates the rural land use dynamic within KwaZulu-Natal and specifically where many of these conditions are most evident, namely: within traditional land tenure areas. The need for an effective, transparent, measurement-based and environmentally linked land use management and regulation system is investigated and a theoretical model is developed with sustainable development as the central focus. The proposed methodology modifies South African approaches to land use management and regulation and draws on the rationale employed within intemationalland use management and state ofthe environment research. The model has the following aims: to strive towards the collective achievement of sustainability as the underlying goal within the planning and plan implementation process; to develop the capability of measuring the extent to which planning policies, goals and programmes are achieved; to guide their review and reformulation; to encourage the inclusion and integration of the policies and programmes of all public and private agencies; and thereby to strengthen the link between land use planning and land use management. The implementation of this model entails an iterative process of performance indicator identification, selection, application and evaluation with full stakeholder participation. The findings suggest that: the sensitive and gradual application of this system is likely to guide land use towards sustainability, initially by non-statutory means. Later, as stakeholder knowledge and understanding increases, this system has the potential to fulfil a valuable statutory function. It is proposed that the practical application of this theoretical approach will facilitate the accurate evaluation and review of policy, plans and programmes during implementation, which will enhance the management and regulation of rural land use towards sustainability within the context of the social, economic and biophysical environment.
The meaning and expression of tourism among urban blacks : a geographic perspective.
(1999) Mkhize, Isidore Bandile.; Butler-Adam, Joann Camille Ellis.; Soni, Dhirajlal Vallabh.
This study was designed to investigate the meaning of the concept of tourism among black South Africans in general and black urban dwellers in particular. The aims of the study were as follows: (a) To look at how black urban dwellers engage in tourist activities. (b) To look at what black urban dwellers understand by the concept of tourism. (c) To find out what places and tourist destinations black people prefer to patronise. (d) To establish the distances black people travel to reach tourist destinations. (e) To focus on the quality of the experiences black people gain at tourist destinations. (f) To gain knowledge about the modes of transport black people use to reach tourist destinations. The dimensions, which pertain to the expression of tourism, were connected. This connection was done in such a way as to reflect on those features of tourism experience which are common amongst urban blacks, and those, which differ for a variety of social and economic reasons. The data presented and analysed in this investigation was gathered from two sources. Quantitative data was collected from a sample of 580 urban black dwellers from several black townships. Qualitative data was collected from 30 families who reside at Esikhawini township. The principal hypothesis of the study is that tourism is not popular among black South Africans mainly because of economic constraints, and a legacy of discriminatory legislation, discriminatory attitudes, as well as the unattractiveness to black tourists of tourist destinations. The sub-hypotheses are as follows: (a) Blacks prefer to visit places where they can be accommodated by friends and relatives. (b) Blacks regard visits to friends and relatives who stay long distances from them as part of tourism. (c) Black people's experience of tourism is more regional than national. (d) Black people prefer to visit urban destinations than rural areas. (e) There are clearly identifiable dimensions of black people's participation in tourism and tourist experience which are common amongst urban blacks. The most important conclusions of the study are: (a) Black urban dwellers understand tourism to mean the practice of travelling for recreation. (b) Black urban dwellers prefer to visit destinations where they can be accommodated by friends and relatives. (c) Black urban dwellers' experience of tourism is more regional than national. (d) Black urban dwellers are mostly attracted to urban destinations than rural areas. (e) Black urban dwellers' tourist experiences have been grossly affected by the policy of apartheid which prohibited them from visiting certain destinations and deprived them of disposable income. The study sheds light on the perceptions and involvement of black urban dwellers in tourism. The investigation of the meaning and expression of tourism among urban blacks is a valuable exercise if tourism is to be made accessible to all South Africans regardless of race, colour and creed. Key words: Tourism, Tourist, Urban Black, Tourist Attraction, Tourism Experience, Tourism Destination.
The geography of health in the Durban Metropolitan Area.
(2002) Moodley, Vadivelu.; Soni, Dhirajlal Vallabh.
In presenting a Geography of Health of the Durban Metropolitan Area, the researcher has chosen a conceptual framework within which to sharply challenge the definition of health in a perfunctory/ functionalist way. Thus, the Geography of Health is, at the outset, locationally positioned in a socio-economic and environmental context of society. This argument is developed through a multi-conceptual approach that leads the thesis into building a framework with the central arching principles of biomedicine, social and humanistic philosophy in three randomly selected informal settlement contexts. The specific focus of this approach is on the growing poverty and homelessness, the inadequate health delivery system and the relationship between disease, physical, social and residential environments and structural inequalities. Thus, this study is embedded in numerous related contexts, the most important of which is the spatial! geographical and the social context in which health and health care is seen in relation to the nature of society and everyday life. To some extent this research endeavour is concerned with health and health care issues amongst specific categories of people within marginalized communities rather than some homogenous, non-existent category called "poor people". The key questions raised in the study relate thus to several variables that impact informal dwellers with the specific objective of determining socio-economic profiles, housing and environmental circumstances; the location and nature of health services; health status of people; the ways in which people conceptualise and prioritise health and the need for and possibility of community involvement in health and health care. In dealing with the above issues, a multi-faceted methodological approach allowed for the generation of 155 tabulations from the quantitative empirical data to be triangulated with the qualitative data produced through focus group interviews and also with the secondary data obtained. The most significant finding emerging from the study was the fact that the relationship between health and abject poverty is bi-directional. Respondents identified numerous factors that affected their health, the most important of which was poverty in respect of poor dwellings, lack of basic services, access to certain health services and the prevalence of disease. It is hardly surprising that a biomedical perspective largely prefaced the respondent's understanding of health. This can be attributed to locational factors but more specifically to the overriding socialising influence of biomedicine in South African society. In the focus group interviews with informal dwellers, the ranking exercises demonstrated that high health risks emerge from multiple and complex factors related to personal, economic, social, environmental and political factors. It is the contention of this thesis that health status improvement and the reduction of health risks of disadvantaged individuals and communities needs a multi-pronged approach with multiple solutions drawing on resources from international, national and local agencies and organisations. Finally, the study concludes by presenting an extensive pool of more concrete systematic and holistic interventions that would not only improve the quality of public health care, but also redefine the Geography of Health in South Africa. These, it is argued are seldom attainable in the short term as it is a continuous process underpinned by priorities, possibilities and planning.
Ozone maxima over Southern Africa : characteristics and mechanisms.
(1995) Combrink, Jane.; Diab, Roseanne Denise.
This thesis aims to clarify the sources of, and mechanisms associated with, the generation of ozone maxima over the southern African region. Inasmuch as, tropospheric ozone concentration is a function of both chemistry and meteorology, this thesis concentrates on the role of atmospheric dynamics. Firstly, a statistical analysis of the relationship between total ozone and meteorological parameters revealed a generally weak negative relationship between total ozone and the height of the 500, 300 and 100 hPa geopotential surfaces. The relationship is best expressed by the passage of a mid-latitude cyclone while anticyclonic conditions exhibited a weak relationship. An examination of the spatial distribution of total ozone and potential vorticity (PV), during the passage of westerly troughs, prompted a more thorough investigation of the exchange of ozone between the stratosphere and troposphere. The relationship between tropospheric ozone, and low pressure and anticyclonic systems is investigated further using data obtained during the South African Fire-Atmospheric Research Initiative (SAFARI) conducted in 1992. Ozone concentrations, as expressed by ozonesonde data, reveal different characteristic profiles for the two scenarios. Explanations for the differences observed are sought in the observed circulation patterns during the experiment. Case studies at Okaukuejo (Namibia), Irene (South Africa) and Brazzaville (Congo), which were utilised as ground stations during SAFARI, are presented in an attempt to gain insight into the vertical distribution of ozone over the entire expanse of the study region. The role of convective systems in the generation of short-lived upper tropospheric ozone maxima at tropical latitudes is illustrated while the different vertical ozone signatures, expressed under cyclonic and anticyclonic systems as described earlier, are reconfirmed by the Okaukuejo and Irene data. An attempt is made to investigate dynamic links between the troposphere and stratosphere and the concomitant exchange of ozone during the passage of westerly trough systems. Particularly deep troughs or cut off low pressure systems are identified as important mechanisms in the generation of upper tropospheric ozone maxima. An examination of the vertical distribution of ozone at Irene during the passage of a COL, using data obtained from the SA'ARI 1994 experiment, suggests concurrence with Danielsen's (1968) model of tropopause folding. The intrusion of high PV and dry stratospheric air, coupled with downward flow near the tropopause, in the vicinity of the upper tropospheric disturbance, promotes the transport of ozone-rich air to tropospheric altitudes. The limited availability of data has severely hampered the understanding of tropospheric ozo~e in southern Africa in the past. This study demonstrates the value of daily vertical ozone data, even for very short periods.
Local atmospheric circulations and the mesoclimate of Durban.
(1970) Preston-Whyte, Robert Arthur.; Davies, Ronald John.
Rapid urban and industrial growth along the Natal coast has occurred with little concern for characteristics of local climate. In general, industrial growth has taken place without taking into account the potential for pollution transportation during the winter season; urban areas have developed without consideration for the vital need in sub-tropical latitudes to maintain adequate mixing of the lower atmosphere. The apparent inadequacy in planning for climate has partly been due to a lack of understanding of the nature and characteristics of local wind systems. The motivation for this study stems , therefore, from the need to evaluate the influence of land-sea and topographically-induced wind systems upon certain aspects of weather and climate on the Natal coast. During summer, moist and relatively cool air is advected almost daily over the Natal coast by the sea breeze . Observations of spatial and temporal variations of these winds were made in the period 1963-69 from recording stations in the Durban area and along a 40-mile transect approximately normal to the coast at Durban. Comparable observations have not as yet been made in South Africa nor have there been a ttempts to examine the influence of sea breezes upon selected climate and weather phenomenon. In this latter connection the role of the sea br eeze is examined in two separate fields in this study, namely urban climatology and thunderstorm development. Climatic discomfort caused by the combined effect of high temperatures and humidities on the Natal coast, is at a maximum in urban areas . Since these areas are also highly populated , a need exists to evaluate the ability of the sea breeze to reduce urban temperatures by advection of cooler air over the area, by eddy diffusion of heat or by displacement of urban temperatures aw~ from poorly ventilated areas. Thus climatic discomfort in these areas may also be reduced. Detailed observations of the influence of the sea breeze, in particular, and wind in general, upon the spatial variation of temperature , humidity and human comfort were, therefore, undertaken in the Durban area. It is believed that this i s the first time an attempt has been made to describe the spatial distribution of a comfort index in an urban area. The results should be of interest to the a rchitect and town planner. The sea breeze, strengthened by gradient and valley Vlinds, is shown to penetrate at least 40 miles inland. In accordance with this , it is suggested that the inland invasion of marine air takes place in response to lowered pressure in adjacent inland areas in southern Natal and provides the moisture required to feed thunderstorms which develop in this area. These storms subsequently move towards the coast following the retreating convergence zone between winds with an onshore and offshore component of motion and reach Durban after sunset. Land breezes are best developed in winter. Observational techniques were similar to those employed in the sea breeze study and provide the only detailed examination of spatial and temporal variations of land breezes in South Africa. Until recently the nature and characteristics of topographically-induced winds in Natal were also a relatively unexplored feature of local atmospheric circulations. However, Tyson (1967) has examined local winds in certain Natal valleys and his prediction that mountain- plain winds reach the coast during the night is also examined in this study. While the relatively weak. and shallow land breeze may be of secondary importance when compared with the sea breeze, it would be a mistake to underestimate the importance of these winds upon certain aspects of coastal climate. In p~rticular the tendency for land breezes to initiate cloud and precipitation at night is examined while the potential for the transportation of atmospheric pollution by these winds is also briefly discussed. A study of the diurnal variation of precipitation at Durban reveals a high frequency of low intensi~ precipitation at night. The nature of this precipitation differs in both frequency and" amount from high intensity rainfall which is the product of thunderstorm and frontal activity. It is suggested in this study that the land breeze plays a dominant role in providing the buoyancy necessary to cause nocturnal drizzle precipitation from shallow stratus cloud. The thesis is divided into four parts. Part I examines details of the physiography, weather, climate, observati ~nal methods and analysis techniques. Because of the variability of weather on the coast of Natal that section is dealt with in more detail than would have been deemed necessary for a similar study inland. Without knowledge of the characteristics of the atmospheric circulation, the behaviour of local wind systems in relation to large scale systems could not be adequately discussed. In Part II land and sea breezes and topographically-induced wind systems are examined in detail. Emphasis is placed not only on the observational characteristics of these winds such as onset, depth, velocity gradient, surging, relation to gradient winds and dissipation but also on their relation to theoretical models of the relevant wind system. The influence of local wind systems upon selected climatic elements is dealt with in Part Ill. Characteristics of the diurnal variation of precipitation are examined in Chapter 6. Rainfall frequencies and amounts are shown to be highest in the first half of the night and a model is developed to explain the influence of land breezes and mountain-plain winds upon low intensity but high frequency nocturnal rainfall. High intensity but low frequency rainfall produced by thunderstorms also occurs soon after sunset and a further model is advanced to explain this phenomenon in relation to the sea breeze. The effect of air movement upon the spatial variation of temperature, humidity and a discomfort index in both summer and winter is examined in Chapters 7 and 8. The relationship between these elements has permitted the development of an empirical model to predict values across the city of mean midday summer and winter temperatures as well as discomfort index values. In Part IV the most significant aspeots relating to the study as a whole are summarised. In conclusion the potential f or the transport of pollutants by land breezes and topographically induced winds is briefly discussed as an aid to planning and siaple spatial models are given showing generalised air movement and ventilation characteristics in the Durban area and along the Natal coast.
An investigation into using textural analysis and change detection techniques on medium and high spatial resolution imagery for monitoring plantation forestry operations.
(2006) Norris-Rogers, Mark.; Van Aardt, Jan.; Ahmed, Fethi B.; Coppin, P. R.
Plantation forestry involves the management of man-made industrial forests for the purpose of producing raw materials for the pulp and paper, saw milling and other related wood products industries. Management of these forests is based on the cycle of planting, tending and felling of forest stands such that a sustainable operation is maintained. The monitoring and reporting of these forestry operations is critical to the successful management of the forestry industry. The aim of this study was to test whether the forestry operations of clear-felling, re-establishment and weed control could be qualitatively and quantitatively monitored through the application of classification and change detection techniques to multi-temporal medium (15-30 m) and a combination of textural analysis and change detection techniques on high resolution (0.6-2.4 m) satellite imagery. For the medium resolution imagery, four Landsat 7 multi-spectral images covering the period from March 2002 to April 2003 were obtained over the midlands of KwaZulu-Natal, South Africa, and a supervised classification, based on the Maximum Likelihood classifier, as well as two unsupervised classification routines were applied to each of these images. The supervised classification routine used 12 classes identified from ground-truthing data, while the unsupervised classification was done using 10 and 4 classes. NDVI was also calculated and used to estimate vegetation status. Three change detection techniques were applied to the unsupervised classification images, in order to determine where clear-felling, planting and weed control operations had occurred. An Assisted "Classified" Image change detection technique was applied to the Ten-Class Unsupervised Classification images, while an Assisted "Quantified Classified" change detection technique was applied to the Four-Class Unsupervised Classification images. An Image differencing technique was applied to the NDVI images. For the high resolution imagery, a series of QuickBird images of a plantation forestry site were used and a combination of textural analysis and change detection techniques was tested to quantify weed development in replanted forest stands less than 24 months old. This was achieved by doing an unsupervised classification on the multi-spectral bands, and an edge-enhancement on the panchromatic band. Both the resultant datasets were then vectorised, unioned and a matrix derived to determine areas of high weed. It was found that clear-felling operations could be identified with accuracy in excess of 95%. However, using medium resolution imagery, newly planted areas and the weed status of forest stands were not definitively identified as the spatial resolution was too coarse to separate weed growth from tree stands. Planted stands younger than one year tended to be classified in the same class as bare ground or ground covered with dead branches and leaves, even if weeds were present. Stands older than one year tended to be classified together in the same class as weedy stands, even where weeds were not present. The NDVI results indicated that further research into this aspect could provide more useful information regarding the identification of weed status in forest stands. Using the multi-spectral bands of the high resolution imagery it was possible to identify areas of strong vegetation, while crop rows were identifiable on the panchromatic band. By combining these two attributes, areas of high weed growth could be identified. By applying a post-classification change detection technique on the high weed growth classes, it was possible to identify and quantify areas of weed increase or decrease between consecutive images. A theoretical canopy model was also derived to test whether it could identify thresholds from which weed infestations could be determined. The conclusions of this study indicated that medium resolution imagery was successful in accurately identifying clear-felled stands, but the high resolution imagery was required to identify replanted stands, and the weed status of those stands. However, in addition to identifying the status of these stands, it was also possible to quantify the level of weed infestation. Only wattle (Acacia mearnsii) stands were tested in this manner but it was recommended that in addition to applying these procedures to wattle stands, they also are tested in Eucalyptus and Pinus stands. The combination of textural analysis on the panchromatic band and classification of multi-spectral bands was found to be a suitable process to achieve the aims of this study, and as such were recommended as standard procedures that could be applied in an operational plantation forest monitoring environment.
Subsurface soil erosion phenomena in Transkei and southern KwaZulu- Natal, South Africa.
(1996) Beckedahl, Heinrich Reinhard.; Fincham, Robert John.
Subsurface erosion forms has been regarded as a unique exception to the more common surficial erosion forms such as rills and gullies, and have therefore been viewed as being of little consequence consequence for the total annual soil loss within any given region. A total of 148 subsurface erosion system occurring at 66 sites in Southern KwaZulu-Natal and Transkei were analysed morphologically to determine the significance of subsurface erosion within this region, to assess the extent to which the observed phenomena may be explained by current theories. Based on morphological criteria related to the dimensions of the subsurface erosion phenomena, it has been shown that there are five distinct -subsurface erosion systems namely scree slope systems; gully- sidewall systems; anthropogenically induced systems; system associated dispersive soils, seepage systems. It was further found that, under certain circumstances, the sediment lost through surficial erosion can be increased 77% by subsurface erosion and the subsurface erosion is spacially to particular slope units which are defined on the basis of the dominant geomorphic processes. Although soil chemistry, in particular dispersion related to the exchangeable Sodium percentage and the Sodium Absorption Ratio, is an important factor in facilitating subsurface erosion, other factors are also important as scree slope systems for example occur in soils which are completely non-dispersive. It has been possible to demonstrate that there is a statistically' significant correspondence between the spatial orientation of inter-ped surfaces the orientation of bedrock joints. This correspondence has enabled the explanation of how the well documented phenomenon of structurally controlled drainage basins may develop._ This correspondence has enabled the explanation of how well documented phenomenon of structurally controlled drainage basins may develop.
An evaluation of the periglacial morphology in the high Drakensberg and associated environmental implications.
(1997) Grab, Stefan Walter.; Hall, Kevin John.; Ahmed, Fethi B.
Although periglacial research in the high Drakensberg and Lesotho mountains has received growing interest amongst southern African geomorphologists, little detailed, quantitative information was available prior to this study. In an attempt to help overcome this deficit, a quantitative assessment on cryogenic landforms and processes operative in the high Drakensberg was undertaken. Morphological and sedimentological assessments of sorted patterned ground, non-sorted steps, thufur, blockstreams, stone-banked lobes, debris deposits and turf exfoliation landforms were undertaken. In addition, geomorphic process assessments in the field included the measurement of turf retreat at turf exfoliation sites, the determination of frost-heave mechanisms within wetlands and sediment mobilization along the Mashai Stream. Ground temperatures were recorded for thufur from 1993 to 1996. The environmental implications of some of the findings are discussed. Seasonal frost-induced sorted patterned ground emerges annually within a few weeks, demonstrating the effect of regular, diurnal freeze-thaw cycles during the winter months. It is found that the present climate is not conducive to maintaining or preserving miniature periglacial landforms below 3200m a.s.l. during the summer months. Large relict sorted circles, stone-banked lobes and blockstreams are the most conspicuous periglacial landforms in the high Drakensberg and are products of at least seasonally-frozen ground. It is suggested that debris deposits found within high Drakensberg cutbacks are possible indicators for marginal niche and cirque glaciation during the Late Pleistocene. It is demonstrated that in climatically marginal periglacial regions, the microtopographically controlled freezing processes may be of paramount importance in maintaining and modifying the cryogenic landforms that occur. Pronounced temperature differentials are found during the winter months, when thufur are frozen for several weeks and depressions remain predominantly unfrozen. It is suggested that such contemporary temperature differentials induce thermodynamic forces and ultimately ground heave at sites in the high Drakensberg. The pronounced seasonal weather patterns in the high Drakensberg have promoted a cycle of geomorphic process events that operate synergistically and initiate particular erosion landforms. However, cryogenic activity during the colder period is overwhelmed by water induced erosion processes during the summer months in the high Drakensberg. It is concluded that the high Drakensberg is currently a marginal periglacial region, but that periglacial conditions prevailed during both the Pleistocene and some Late Holocene Neoglacial events.
Natal : a study in colonial land settlement.
(1969) Christopher, Anthony John.; Davies, Ronald John.
No abstract available.
Communal space construction : the rise and fall of Clairwood and district.
(1994) Scott, Dianne.; McCarthy, Jeffrey J.
This study documents the emergence of an Indian cultural enclave located on the periphery of the colonial town of Durban, its subsequent rise to a flourishing communal space by the mid twentieth century, and its decline in the apartheid era. The focus on change and transformation locates the research question within the broad ambit of historical geography. Clairwood and District grew into a densely-populated informal living space with all facilities and institutions built by the community. Based on a cultural inheritance in the form of language, the extended family system and religious beliefs , the Indian settlers and their descendants developed an elaborate network of kinship and communal relationships which formed the moral and social framework for the process of communal space construction. Entering the colony of Natal predominantly as indentured labour, the Indians were from the outset ostracized and subjugated by the white settlers and perceived as an alien temporary group. This identity was henceforth embodied in discriminatory legislation which marginalized the Indians in South Africa and resulted in their neglect and spatial containment. Parallel to the organic process of Indian communal space construction occurring in southern Durban was the sustained policy of land-use transformation embarked upon by the Durban municipality. The goal of this policy was to create a 'productive zone' south of Durban within an explicit racial zoning plan. The application of this goal resulted in a clash between the dominant white culture and the subordinate Indian culture as each.sought to retain control of the southern corridor and define its land-use and identity. After a protracted struggle the Durban municipality succeeded in imposing a formal industrial landscape upon the communal living space with the exception of the small node in Clairwood itself which has remained a residential enclave. This vestige of the former flourishing residential area of Clairwood and District suffers from industrial penetration and a physically degraded environment. However, it retains a sense of place of the former vibrant community. Clairwood is currently undergoing a process of revitalization under the auspices of the Durban municipality with a subsequent redefinition of identity. The study documents the cultural meanings that have been produced in a unique urban landscape in a South African city revealing the need to uncover the historical geographies of minority groups as a source of identity and a resource for future urban reconstruction.
Assessment of structural attributes of even-aged Eucalyptus grandis forest plantations using small-footprint discrete return lidar data.
(2009) Tesfamichael, Solomon Gebremariam.; van Aardt, Jan.; Ahmed, Fethi B.
Assessment of forest structural attributes has major implications in the management of forestry by providing information of ecological and economic importance. The traditional methods of assessment involve collecting data in the field and are regarded as labour-intensive and expensive. In plantation forestry, field campaigns are generally time consuming and costly, and may compromise profit maximisation. The introduction of lidar (light detection and ranging) remote sensing in forestry has shown promise to add value to the traditional field inventories mainly through large spatial coverages in a timely and cost-effective manner. Lidar remote sensing is an advanced system capable of acquiring information in both the vertical and horizontal dimensions at relatively high resolutions. Numerous studies have established that these qualities of lidar data are suited to estimating forest structural attributes at acceptably high accuracies. The generic approach in most studies is to use lidar data in combination with field data. Such an approach still warrants a high cost of inventory. It is therefore useful to explore alternative methods that rely primarily on lidar data by reducing the necessity for field-derived information. The aim of this study was to derive structural attributes of even-aged Eucalyptus grandis forest plantations using lidar data. The attributes are of significance to timber resource assessments and include plot-level tree height attributes, stems per hectare (SPHA), and volume. The surveyed field data included tree counting and measurement of tree height and diameter at breast height for sample plots. Volume was then calculated using standard allometric models. Small-footprint lidar data of the plantations were also acquired coincident with the field inventories. Mean tree height and dominant height were estimated at a range of simulated lidar point densities between 0.25 points/m2–6 points/m2. Various plot-level distributional metrics were extracted from height values of lidar non-ground points and related with field mean and dominant height values using stepwise regression analysis. The results showed that both attributes could be estimated at high accuracies with no significant differences arising from variations in lidar point density. Estimation of SPHA relied on the exploration of semi-variogram range as a mean window size for applying local maxima filtering to the lidar canopy height surface. A comparative approach of window size determination used pre-determined within-row tree spacing, based on planting information. Two secondary objectives were addressed: comparing spatial resolutions of canopy height surfaces interpolated from non-ground height values and comparison of lidar point densities simulated at three levels. Comparison of spatial resolutions of canopy height surfaces were performed at 0.2 m, 0.5 m, and 1 m using a lidar point density of 5 points/m2. The results indicated that 0.2 m is the most appropriate resolution for locating trees and consequently deriving SPHA. Canopy height surfaces of 0.2 m resolution were created at simulated densities of 1 point/m2, 3 points/m2, and 5 points/m2. While all estimates were negatively biased relative to field-observed SPHA, lidar densities of 3 points/m2 and 5 points/m2 returned similar accuracies, which were both superior to 1 point/m2. It was concluded that 3 points/m2 was sufficient to achieve the accuracy level obtained from higher lidar point densities. Plot-level mean height, dominant height, and volume of trees were estimated for trees located using local maxima filtering approaches at the three lidar point densities. Mean height and dominant height were both estimated at high accuracies for all local maxima filtering techniques and lidar point densities. The results were also comparable to the approach that employed regression analysis that related lidar-derived distributional metrics and field measurements. Estimated dominant height and SPHA, as well as age of trees, were used as independent variables in a function to estimate plot-level basal area. The basal area was then used to compute diameter of the tree with mean basal area, referred to as quadratic mean diameter at breast height (QDBH). Mean tree height and QDBH were used as independent variables in a standard equation to calculate mean tree volume, which was then scaled up to the plot-level. All estimates for the local maxima filtering approaches and lidar point densities returned negatively biased volume, when compared to field observations. This was due to the underestimation of SPHA, which was used as a conversion factor in scaling up from tree-level to plot-level. Volume estimates across lidar point densities exhibited similarities. This suggests that low lidar point densities (e.g., 1 point/m2) have potential for accurate volume estimation. It was concluded that multiple forest structural attributes can be assessed using lidar data only. The accuracy of height derivation meets the standards set by field inventories. The underestimation of SPHA may be comparable to other studies that applied different methods. However, improved estimation accuracy is needed in order to apply the approaches to commercial forestry scenarios. The significance of improving SPHA estimation extends to improved volume estimation. In addition, the potential improvement should also take into consideration the density of lidar points, as this will impact on the cost of acquisition. This research has taken a significant step towards determining if lidar data can be used as a stand-alone remote sensing data source for assessment of structural plantation parameters. Not only does such an approach seem viable, but the lower required point densities will help to reduce acquisition costs significantly.
A comparative study of soil erosion in the Umfolozi Game Reserve and adjacent Kwazulu area from 1937 to 1983.
(1990) Watson, Helen Kerr.; De Villiers, G du T.
This thesis describes a comparative study of actual and potential soil erosion in the Wilderness area of the Umfolozi Game Reserve, and a biophysiographically comparable adjacent traditional KwaZulu landuse area. Estimates of temporal and spatial variations in eroded surfaces, sparsely vegetated surfaces susceptible to erosion, and active gullies were obtained from five sets of sequential aerial photographs taken between 1937 and 1983. Estimates of the potential influence of rainfall erosivity, soil erodibility, topography, and changes in vegetation communities and landuse practices on these variations, were extrapolated from these aerial photographs as well as from maps, field surveys, records and other studies. Interrelationships between these potential influences, and the extent to which they actually contributed to the temporal and spatial variations in the three 'erosion' surfaces, were assessed visually using a geographic information systems thematic overlay technique, and computationally using a forward stepwise multiple regression procedure.

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