• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1123
  • 837
  • 556
  • 122
  • 105
  • 99
  • 96
  • 54
  • 45
  • 32
  • 25
  • 25
  • 25
  • 25
  • 25
  • Tagged with
  • 3872
  • 566
  • 353
  • 330
  • 326
  • 315
  • 275
  • 271
  • 250
  • 243
  • 241
  • 233
  • 225
  • 221
  • 211
  • 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.
61

Hazard responses in the pre-industrial era : vulnerability and resilience of traditional societies to volcanic disasters

Sangster, Heather January 2013 (has links)
This thesis has two aims to: a. assess the vulnerability and resilience of traditional societies and those on the threshold of modernisation to volcanic and volcano-related disasters; and b. evaluate the extent to which historical events and their associated responses may inform future policies of disaster management. In order to address these aims this thesis has three objectives, these being: a. to test the strengths and weaknesses of two methodologies, an historical approach based on archival and other information - applied to Etna and Vesuvius and a set of techniques focused around vulnerability and resilience – applied to the Azores; b. to identify traditional strategies of coping and survival during the pre-industrial period in the three case-study areas; and c. to evaluate the potential use of these data in the development of future disaster management plans. During this research techniques from the earth sciences (i.e. field data collection) were combined with those more commonly seen in historical studies (i.e. archival data sources) to draw out the ways in which people have coped in the past to eruptions. Field visits were carried out on Etna, Sicily (Italy) and São Miguel Island, Azores (Portugal). The principal conclusions of this research are:- a. That the historical and vulnerability and resilience approach worked well, respectively for Etna and the Azores. b. Less successful was the application of the historical approach to Vesuvius. In contrast to Etna this reflected amongst other things the fact that the last eruption occurred nearly seventy years ago (i.e. in 1944) and since that time the ‘folk’ memory of volcanic activity has been largely expunged because of rapid economic development combined with population growth. c. In all three case study areas, volcanic earthquakes are an under-stated hazard; the process of development is increasing vulnerability and the practice of popular Catholicism does not prevent responses based on scientific understanding and civil defence planning. The study identifies that future work would benefit from the application of a vulnerability and resilience based methodology grounded within both historical and contemporary contexts.
62

Quantifying uncertainty in climate-driven disease risk predictions

MacLeod, David January 2013 (has links)
This thesis considers the uncertainty in forecasts of climate-driven disease risk, focusing on seasonal and decadal timescales. An analysis of the skill of decadal climate predictions is carried out, looking at the first multi-model decadal hindcast set produced as part of the ENSEMBLES project. Some skill in the prediction of global average temperature trends over the forthcoming decade is shown, with no skill evident for precipitation. Focusing on smaller areas shows limited skill in predicting temperature trends and no skill for precipitation trends, suggesting that decadal climate models cannot currently make useful predictions of disease risk. Seasonal climate forecasting skill is then considered. Seasonal hindcasts produced by two research projects, DEMETER and ENSEMBLES, are compared with the most recent version of the European Centre for Medium-Range Weather Forecast’s seasonal forecast model, System 4. The models are validated over Africa and the Indian subcontinent, and it is shown that in general System 4 forecasts are an improvement over the DEMETER and ENSEMBLES multimodel ensembles, particularly for West Africa. A more in depth study of System 4 is subsequently carried out, comparing the variation in skill between forecast start dates. Forecast value is demonstrated at multiple lead times, with most skill found for West African regions and Botswana and limited skill for India; indicating when and where forecasts can potentially be issued to users. Forecasting malaria is then studied by using Liverpool Malaria Model (LMM) driven by System 4. Skill is demonstrated over Botswana, particularly for forecasts issued in November, validating against laboratory confirmed cases of malaria. This is an improvement on previous work where the LMM was driven with the DEMETER seasonal hindcasts. Where malaria data is not available, System 4-driven LMM hindcasts are compared to LMM driven by ERA-Interim in a tier-2 validation context. Skill is demonstrated at the epidemic fringe of the Sahel and in north west Malawi, whilst the Gulf of Guinea shows no skill. This is consistent with previous work suggesting the LMM performs better in epidemic than in endemic regions. A method for interpreting hindcast validation results as uncertainty quantification is then presented. Finally, the uncertainty in the relationship between seasonal average climate and malaria risk is analysed, using the LMM driven by the 20th century reanalysis dataset. The relationship parameters describing seasonal average climate and malaria risk is explored and impact surfaces are created, relating seasonal average temperature and precipitation to average seasonal malaria incidence. The robustness of these impact surfaces is investigated by comparing the surfaces associated with different LMM survival schemes. A method of combining impact surfaces based on tercile categories is described and implemented and it is demonstrated how the resulting graphic could be integrated with a seasonal ensemble forecast system. Such a tool is potentially useful for decision-makers, allowing an intuitive visual communication of the quantified uncertainty in predicting climate-driven disease risk at seasonal timescales.
63

Questioning the principles of sustainable tourism development : a case study of Cocachimba, Peru

Raftopoulos, Malayna January 2013 (has links)
With the emergence of the sustainable development paradigm in the 1980s and the growth of the travel industry it seemed inevitable that the two would coincide at one point or another. Emerging as a reaction to mass tourism and environmental destruction, sustainable tourism development is a combination of two main schools of thought; development theory and environmental sustainability. Once assumed to be a passing fad, two decades on the concept has gained widespread acceptance both within the academic circles and governments. Since the early 1990s, the sustainable tourism paradigm and its practical applicability has become the subject of much debate. Although it is widely acknowledged that sustainable tourism is impractical at macro level, it has long been thought that the principles of sustainable tourism development could be successfully applied at micro level. This thesis aims to contest this statement and demonstrate that small scale sustainable tourism development is just as unattainable. Drawing upon existing literature, it aims to weave together tourism and development theory and examine the links and discrepancies between the principles of sustainable tourism development and the wider framework of sustainable development. In doing so it reveals a number of fundamental weaknesses which undermine the viability of sustainable tourism development. In addition to examining the discrepancies and contradictions of the concept, the thesis also forms a link between the principles and practices of sustainable tourism development and a destinations area ‘life cycle’, thereby; providing a framework for its analysis. Using a sustainable tourism development cycle model (STDC), it will show how as a destination area passes through the various stages of tourism development it moves further away from the principles of sustainable development and consequently fails to meet the fundamental principles of sustainable development. Built upon and adapted from Butler’s (1980) ‘tourism area life cycle’ theory, the STDC model questions the sustainability of a tourism destination area and evaluates its progress in implementing the principles of sustainable tourism development as it evolves.
64

Tourism and sustainable development : active stakeholder discourses in the Waterberg Biosphere Reserve, South Africa

Lyon, Andrew January 2013 (has links)
The aim of this thesis is to examine the extent to which tourism is a sustainable development (SD) option in the Waterberg Biosphere Reserve (WBR), South Africa. It examines the discourses of those stakeholders who can actively affect decisions or actions regarding sustainable tourism development (STD). The literature on tourism points to it being a contested development option, with a number of positive aspects which are mainly economic fitting with the neoliberal development paradigm. There are however critical concerns over the ability of tourism to contribute to the wider issues surrounding SD. There are also conceptual and practical issues regarding SD/STD with stakeholders having varying approaches to, and positions on, the concepts. This case-study examines tourism development in the predominantly rural WBR which has seen tourism become the major economic and land-use sector in the area. Biosphere reserves are a United Nation’s designation stipulating that the region should endeavour to follow the principles of SD. Therefore, how tourism develops in the area has implications for the SD of the biosphere reserve area. An inductive qualitative methodology was designed to collect and analyse the discourses of those stakeholders who can actively affect STD concerns within the WBR. Critical discourse analysis is used to reveal notions of power, ideology and knowledge relating to the macro contexts of development, SD, STD and the micro context of the geographical area. The discourses of the active stakeholders reveal that tourism is seen mainly as an economic driver and SD discourses do emerge regarding the environment and futurity or concern for future generations. The discourses also uncover a strong ‘sense of place’ attachment to the region and a desire to conserve the environment. However they show that tourism does not contribute to wider SD objectives of basic needs, poverty reduction, quality of life improvement and population levels. This thesis reveals how levels of knowledge from active stakeholders, influenced by ideology, affect power in the region. The main contribution of this research is that active stakeholder discourses need to be understood in the contexts of development and that the link between discourse, knowledge, ideology and power needs to recognised when examining tourism as a sustainable development option.
65

Reconstructing historical sea-level trends for the Croatian coast of the Adriatic Sea using salt-marsh foraminifera

Shaw, Timothy January 2013 (has links)
The application of salt-marsh foraminifera to reconstruct historical sea-level trends was investigated for the Croatian coast of the Adriatic Sea using a transfer function approach. This technique, whilst well practised from north Atlantic sites along the shores of America and UK, has previously evaded any published study in the Mediterranean region. A total of 70 surface samples were collected across separate transects established at two micro-tidal salt-marsh sites from the central Croatian coastline to establish a modern dataset of foraminifera. In addition, environmental variables were also investigated including salinity, pH, organic matter, particle size, distance (from open water) and altitude, relative to the Croatian national datum. Three sediment cores were sampled for fossil foraminifera and composite chronologies involving short-lived radionuclides, radiocarbon dating and pollution indicators from XRF. Age-depth models were created using classical and Bayesian approaches. Quantitative analysis of the foraminiferal assemblages revealed on average three faunal zones in which characteristic species occurred. This comprised a faunal zone composed almost exclusively of agglutinated species; J. macrescens, T. inflata and M. fusca extending between mean tidal level (MTL) and beyond MHWST (higher altitude). A second faunal zone was more variable and comprised of a mixed assemblage of agglutinated species described above in addition to calcareous species; Ammonia spp., Elphidium spp., Haynesina germanica and Quinqueloculina spp. This zone spanned a large vertical range above and below MTL. In a third faunal zone calcareous species dominated and was restricted to the lower altitudes of the salt-marsh environments. Further quantitative measures were employed to test the hypothesis that foraminiferal distributions were controlled by altitude. Partial ordination techniques revealed altitude as a statistically significant control confirming their suitability as proxies for sea-level in transfer function reconstructions. An analysis of species environment relationships revealed strong linear response suggesting the use of PLS regression models. Transfer functions were then developed for both site specific and a total combined dataset, where small r2 jack values largely reflected the short environmental gradients despite relatively low predictions errors (RMSEP jack = <0.11). The total combined dataset was chosen and screened to remove sample outliers improving model performance (r2 jack = 0.54 and RMSEP jack = 0.08). Finally, the transfer function model was applied to core sediments to reconstruct mean sea-level where an inflexion observed at AD 1940 showed acceleration comparable to other proxy reconstructions. Indeed this trend was similar to instrumental data from Trieste tide-gauge records. Similarly the transfer function reconstruction identifies the dramatic increases in MSL observed in both tide-gauge (Split and Trieste) and satellite observations since the early 1990s.
66

The deposition and storage of suspended sediment in contemporary floodplain systems : a case study of the River Culm, Devon

Simm, David John January 1993 (has links)
This thesis documents the rates and patterns of contemporary and recent overbank deposition along the lower reaches of the River Calm, S. E. Devon, England. Two temporal perspectives are adopted: (i) short-term rates based on contemporary flood events, using sediment traps, the sampling of in-channel suspended sediment and qualitative field observation of inundation processes; and, (ii) recent (over the past 35 years) rates of vertical accumulation, using the caesium-137 technique. These techniques also enable lateral and downstream trends to be identified. Longer-term implications are also addressed using a simple lithofacies classification of alluvial sections, supplemented by historical evidence of channel change and anthropogenic impact along the study reach. Overbank deposition rates are generally low along the study reach, averaging 0.7 mm year-1 (using estimates of suspended sediment conveyance losses), 0.4 mm year-1 (sediment traps) and 0.5 mm year-1 (caesium-137 studies). In general, the highest deposition rates are associated with the levee, depressions and breaches. Deposition rates, however, are temporally and spatially highly variable, being dependent upon the microtopographic relief and vegetation of the floodplain, the mode of inundation, and the extent of retention pondage. Anthropogenic impact on the floodplain is also noted, in particular the role of ditches in distributing floodwaters across the floodplain and the compartmentalisation effect of barriers to flow. These have important implications for the rates of overbank deposition and the sedimentological characteristics of deposits. The role of scour remobilisation of sediment is also assessed. The spatial detail afforded by the caesium-137 technique has been used to identify areas of the floodplain which may be locally susceptible to scour. This study highlights the potential for lowland floodplains undergoing regular flooding to suffer contamination from radionuclides and other pollutants, and leads to an improved understanding of the spatial and temporal rates and trends in deposition and sedimentological characteristics of overbank deposits on the floodplain of a suspension load-dominant river system.
67

Disentangling water governance in Dar es Salaam : the role of NGOs and community water provision

Pritchard, Nicola F. January 2017 (has links)
This thesis aims to provide a contemporary account of the Dar es Salaam’s water sector as well as the role of the myriad stakeholders involved in it, taking into account the complexity history of the city’s water governance. As a rapidly growing city over recent years, the infrastructure of Dar es Salaam’s municipal system has not been updated for a significant period of time. As such, the areas served by this system face intermittent and piecemeal coverage whereas other large sections of the city are forced to come up with alternative, often expensive water resources that are unreliable and at times, unsafe. This thesis attempts to explore the lived realities of the individuals who reside in these unserved areas, and the ways in which community-based organisations and non-governmental organisations (NGOs) play a role in the city’s water sector. Through analysis of community-level water provision schemes in two case study areas of Dar es Salaam, this research provides a thorough account of the ways in which water resources are managed, debated and utilised at the local level and the challenges faces by these local organisations. In addition, through an observational research at two local NGOs working in the water sector in Dar es Salaam, this research examines these organisations’ place within the city’s broader water governance framework, as well as how they operate and prioritise their day to day work and their outputs. This research also takes into account the national and international policy environment, as well as the ways in which Tanzania’s socio- political history has influenced the current means of water governance. Through an exploration of the prevalent discourses in policy creation and implementation and the aforementioned stakeholders in the water sector, this thesis examines the multitude of influences on Dar es Salaam’s water governance, as well as the tensions that arise between rhetoric and reality, and the impacts these have upon its citizens.
68

The social life of street food : exploring the social sustainability of street food in Hanoi, Vietnam

Stutter, Natalia January 2017 (has links)
This research explores the social life of street food in Hanoi, Vietnam, using a conceptual framework of social sustainability. Although the economic benefits of street vending are widely recognised, little attention has previously been paid to the social aspects. Focusing specifically on the selling of street food through the lens of social sustainability, this research develops a conceptual framework from the literature. The framework comprised eight key themes: social justice, quality of life and well-being, participation, safety and security, social interactions and social networks, social inclusion, sense of place and cultural heritage and was applied empirically to the street food environment of Hanoi. The themes used in the framework were identified as the most pertinent in the literature and were grouped under three broad ideas – social justice, social relations and culture – and used to frame the thesis. The application of the social sustainability framework revealed important details about the social life and social function of the street food environment. It highlighted key areas where street food in Hanoi can be shown to contribute to the principles of social sustainability, such as regarding social relations, cultural heritage and sense of place. It also drew attention to areas that require improvement, including some aspects of social justice, for example, participation, safety and security and food hygiene. The findings of this research suggest the challenges identified that prevent the social sustainability of street food in Hanoi, often manifested themselves through the inequalities experienced between the different types of street food vendors, specifically itinerant or migrant vendors compared to local vendors with fixed selling locations. The thesis argues that the approach adopted in the research offers a useful tool for understanding the social functions of street vending which can be applied and adapted to examine the social sustainability of street food vending in other economic and political contexts.
69

Ethical agency within the responsible tourism experience : a PARTicipative inquiry

Ingram, Claire January 2018 (has links)
This thesis examines consumers’ ethical agency within the responsible tourism experience. It aligns with a post-structuralist, (late) Foucauldian position, adopting the theoretical constructs of ‘power struggles’ (1982), ‘problematisations’ (1984a) and ‘self-care practices’ (1984c) to engender a more fluid view of the market-consumer interface. It investigates (i) how consumers conform to, critique or resist market-promulgated ways of being a ‘responsible tourist’; (ii) how consumers (re)negotiate alternative meanings of how to be ethical and act ethically; (iii) what this reveals about the ways in which consumers retain, apportion or relinquish a sense of autonomy over their ethicality; and (iv) the tensions, struggles and dilemmas that consumers concurrently face. The thesis adopts a participative methodology in order to foster the involvement of participants across the total tourism experience. More specifically, the thesis conducts a PARTicipative inquiry in order to facilitate data collection before, during and after the holiday; enabling ‘prospective’, ‘active’ and ‘reflective’ triangulation (Ingram et al, 2017). To this end, the thesis presents data from participants’ pre-holiday and post-holiday interviews, as well as their (on-holiday) diaries and photographs. The findings of this thesis suggest that consumers’ ethical agency manifests in three main ways. Agency is represented through a critical awareness of the rhetorical construction of ‘responsibility’ within three types of market-consumer interface, namely ethical tourism spaces, ethical policies and market materials. Agency is also represented through consumers’ resistance towards three key areas of the organised tourism industry, specifically large corporations (e.g. chain hotels, international franchises), the tourism ‘package’, and tourism ‘hotspots’. Further, agency is represented through consumers’ self-reflexivity. Tourists are highly introspective of the ways in which they transform personal ethical reflection into action (‘walk the talk’); the ways in which they reflect on ethics but are unwilling to make any material alterations to their behaviour (‘reflexive inertia’); and the personal, product, and destination level considerations that impede their engagement in certain ethical practices (‘pragmatic utility’). Overall, this thesis aims to contribute to existing literature by fulfilling four research gaps. First, it focusses on the practices and narratives of responsible tourists, as opposed to the ‘responsibility’ discourses of travel companies (e.g. Caruana & Crane, 2008; Hanna, 2013). Second, it attends to the current lack of Foucauldian ethics within the consumer responsibility and responsible tourism literatures (Crane et al, 2008). Third, it progresses from studying the ethical consumption of commodity goods to focus on experiential consumption; specifically, highly performative experiential consumption in a potentially environmentally and socio-culturally disparate context to the ‘home’ setting (e.g. Jamal, 2004). Finally, it focusses on the total responsible experience by triangulating tourists’ prospective, active and reflective data. This thesis also has important practical implications. A stronger awareness of how tourists experience responsible tourism will better enable the tourism industry to tailor their products, services and spaces in a way which more effectively matches consumer demand. Further, an improved understanding of how consumers evaluate discourses on ‘responsibility’ will inform the tourism industry as to how responsible policies, guidebooks and other marketing messages are interpreted, and thereby constructed and communicated.
70

Analysis of extreme precipitation events over the eastern Red Sea coast for recent and future climate conditions

Alharbi, Mohammad Mosaed Eid Alahmadi January 2018 (has links)
The investigation of extreme precipitation events over the western coast of Saudi Arabia is necessary to estimate their potential impact on both socioeconomic activities and the regional environment. The current study aims at understanding the atmospheric dynamics leading to extreme precipitation, to improve weather forecasting in the target region and the development of long-term adaptation policies. Preliminary results reveal that extreme precipitation events in this region occur during the wet season (Nov–Jan). The synoptic mechanisms of these events are a function of the complex interaction between tropical, subtropical and middle-latitude dynamics. The synoptic dynamic processes were identified by a subjective study of the highest 30 extreme events. In addition, the weather circulation patterns (WCPs) of all extreme events were classified objectively by means of an empirical orthogonal function (EOF) analysis based on the mean sea level pressure. WCPs were linked with synoptic dynamic processes and teleconnected with large-scale climate variability modes. Furthermore, WCPs, precipitation and data regarding other atmospheric variables from different regional climate models were used to investigate future changes in extreme precipitation events under climate change. The most important weather circulation patterns, which are associated with extreme precipitation events, were identified. The possibility of extreme precipitation events increases with great uncertainty.

Page generated in 0.0258 seconds