Identifying growth criteria and sediment movement mechanisms of needle ice using high-frequency environmental and visual monitoring
- Authors: Borg, Carl-Johan
- Date: 2017
- Subjects: Frazil ice , Sediment transport , Ice mechanics , Photography -- Digital techniques , Environmental monitoring
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/17656 , vital:22268
- Description: Environmental growth conditions and mechanisms involved in sediment transport by needle ice have historically been difficult to assess and are poorly documented. The spatial and temporal dynamics that relate to the environment, growth and decay of needle ice are not fully understood. This study monitored needle ice growth, melt and visually identified sediment displacement mechanisms by needle ice, with the aim of revealing environmental growth criteria, timing of growth/melt, ground-surface-air energy balance and sediment displacement mechanisms. Furthermore, the impact of needle ice displacement on vegetation and patterned ground formation was analysed. High-frequency visual monitoring, using three cameras, supplemented by high-frequency measurements of air temperature, soil moisture and wind speed was used to investigate needle ice growth and decay dynamics. Results from visual and environmental monitoring of needle ice growth, showed that the needle ice growing environment was more dynamic, especially in terms of surface temperature, than previously argued. Needle ice growth was observed to occur during surface temperatures from -2.0°C to 2.2°C, soil moisture levels from 0.4% to 37.4% and in winds speeds of 0 m/s to 12.6 m/s. Needle ice initiation was documented a few minutes to hours before or after the onset of surface temperature dropping to below 0°C. Imagery displayed that the depth of ice nucleation was variable within the soil column, possibly relating to the energy balance of radiative cooling, convective heat loss, ground conductivity and latent heat release at the air-surface-ground boundary. Heaving and resettling, toppling and rolling were identified as slope displacement mechanisms when needle ice decayed. Animal trampling and hail were additionally documented as substantial surface altering processes. Furthermore, no impact of needle ice reducing vegetation stability was identified, although a tendency to hinder vegetation expansion was noted. Also, no creation of patterned ground was observed as a result of needle ice decay.
- Full Text:
- Date Issued: 2017
- Authors: Borg, Carl-Johan
- Date: 2017
- Subjects: Frazil ice , Sediment transport , Ice mechanics , Photography -- Digital techniques , Environmental monitoring
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/17656 , vital:22268
- Description: Environmental growth conditions and mechanisms involved in sediment transport by needle ice have historically been difficult to assess and are poorly documented. The spatial and temporal dynamics that relate to the environment, growth and decay of needle ice are not fully understood. This study monitored needle ice growth, melt and visually identified sediment displacement mechanisms by needle ice, with the aim of revealing environmental growth criteria, timing of growth/melt, ground-surface-air energy balance and sediment displacement mechanisms. Furthermore, the impact of needle ice displacement on vegetation and patterned ground formation was analysed. High-frequency visual monitoring, using three cameras, supplemented by high-frequency measurements of air temperature, soil moisture and wind speed was used to investigate needle ice growth and decay dynamics. Results from visual and environmental monitoring of needle ice growth, showed that the needle ice growing environment was more dynamic, especially in terms of surface temperature, than previously argued. Needle ice growth was observed to occur during surface temperatures from -2.0°C to 2.2°C, soil moisture levels from 0.4% to 37.4% and in winds speeds of 0 m/s to 12.6 m/s. Needle ice initiation was documented a few minutes to hours before or after the onset of surface temperature dropping to below 0°C. Imagery displayed that the depth of ice nucleation was variable within the soil column, possibly relating to the energy balance of radiative cooling, convective heat loss, ground conductivity and latent heat release at the air-surface-ground boundary. Heaving and resettling, toppling and rolling were identified as slope displacement mechanisms when needle ice decayed. Animal trampling and hail were additionally documented as substantial surface altering processes. Furthermore, no impact of needle ice reducing vegetation stability was identified, although a tendency to hinder vegetation expansion was noted. Also, no creation of patterned ground was observed as a result of needle ice decay.
- Full Text:
- Date Issued: 2017
An analysis of digital photojournalistic practices: a study of the Sowetan's photographic department
- Authors: Allan, Christopher
- Date: 2003
- Subjects: Sowetan (Johannesburg, South Africa) , Photojournalism -- South Africa , Photography -- Digital techniques , Photojournalists -- South Africa , Photojournalism -- South Africa -- Moral and ethical aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3496 , http://hdl.handle.net/10962/d1003071 , Sowetan (Johannesburg, South Africa) , Photojournalism -- South Africa , Photography -- Digital techniques , Photojournalists -- South Africa , Photojournalism -- South Africa -- Moral and ethical aspects
- Description: Photojournalism in South Africa is in the process of undergoing a shift from an analogue past to a fully digital future. This shift to digital has already been completed by many of the newspapers in the United States of America and Europe, and the new technology is seen to have made fundamental differences in the way that journalists do their job. This thesis attempts to explore the differences brought about, as well as the problems experienced by the photographic department at the Sowetan newspaper as a result of the shift to digital. How the development of technology has affected the photojournalist throughout is focused upon in a brief history of photojournalism and examples of how technology has shaped different aspects of journalism in both a positive and negative manner is considered. Exactly what digital photography is, how it has been integrated into American Photographic departments and the changes that the new technology has prompted are also explained. The manipulation of images in the past as well as the relative ease of digital manipulation are covered and concerns are raised about the future implications of digital manipulation. By conductlng participant observation and holding interviews, research data was compiled which allowed conclusions to be drawn about the impact that the shift to digital had had on the Sowetan photographic department. Intentional and unintentional consequences were expected and revealed in the research. The job of the photojournalist and photographic editor was found to have changed but perhaps not as dramatically as expected. Third world factors such as crime, poverty and lack of education were discovered to have resulted in problems that differed noticeably from those experienced by American and European photographic departments. Some expected difficulties were not experienced at all, while other major obstacles, specifically the repairs that must constantly be made to the digital cameras, continue to hamper the operations of the new digital department. Some understanding of the problems that might be encountered by future photojournalism departments that are considering making the shift to digital are arrived at, in the hope that they may be foreseen and overcome.
- Full Text:
- Date Issued: 2003
An analysis of digital photojournalistic practices: a study of the Sowetan's photographic department
- Authors: Allan, Christopher
- Date: 2003
- Subjects: Sowetan (Johannesburg, South Africa) , Photojournalism -- South Africa , Photography -- Digital techniques , Photojournalists -- South Africa , Photojournalism -- South Africa -- Moral and ethical aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3496 , http://hdl.handle.net/10962/d1003071 , Sowetan (Johannesburg, South Africa) , Photojournalism -- South Africa , Photography -- Digital techniques , Photojournalists -- South Africa , Photojournalism -- South Africa -- Moral and ethical aspects
- Description: Photojournalism in South Africa is in the process of undergoing a shift from an analogue past to a fully digital future. This shift to digital has already been completed by many of the newspapers in the United States of America and Europe, and the new technology is seen to have made fundamental differences in the way that journalists do their job. This thesis attempts to explore the differences brought about, as well as the problems experienced by the photographic department at the Sowetan newspaper as a result of the shift to digital. How the development of technology has affected the photojournalist throughout is focused upon in a brief history of photojournalism and examples of how technology has shaped different aspects of journalism in both a positive and negative manner is considered. Exactly what digital photography is, how it has been integrated into American Photographic departments and the changes that the new technology has prompted are also explained. The manipulation of images in the past as well as the relative ease of digital manipulation are covered and concerns are raised about the future implications of digital manipulation. By conductlng participant observation and holding interviews, research data was compiled which allowed conclusions to be drawn about the impact that the shift to digital had had on the Sowetan photographic department. Intentional and unintentional consequences were expected and revealed in the research. The job of the photojournalist and photographic editor was found to have changed but perhaps not as dramatically as expected. Third world factors such as crime, poverty and lack of education were discovered to have resulted in problems that differed noticeably from those experienced by American and European photographic departments. Some expected difficulties were not experienced at all, while other major obstacles, specifically the repairs that must constantly be made to the digital cameras, continue to hamper the operations of the new digital department. Some understanding of the problems that might be encountered by future photojournalism departments that are considering making the shift to digital are arrived at, in the hope that they may be foreseen and overcome.
- Full Text:
- Date Issued: 2003
An informed community's perception of the impact of digital technology on the credibility of news photography
- Authors: Làzaro, Angelique Maria
- Date: 2000
- Subjects: Photojournalism -- Moral and ethical aspects , Digital media , Photojournalists , Photography -- Digital techniques
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3451 , http://hdl.handle.net/10962/d1002905 , Photojournalism -- Moral and ethical aspects , Digital media , Photojournalists , Photography -- Digital techniques
- Description: South African photojournalists’ perception of digital technology’s impact on the credibility of news photographs is investigated in this study. Digital technology has the capabilities to produce “manipulated” photographs that appear realistic and credible. Credibility is dependent on a variety of factors including codes of realism and codes of production, which fit conventional codes of photographic representation. Manipulation is the act of deviating from accepted codes of photographic representation that may jeopardise the credibility of news photography. This thesis proposes a new theoretical framework that encompasses existing theories of semiotics, ideology, naturalism, realism and credibility. These theories underpin the definitions and discussion on manipulation and credibility. A descriptive survey is used which attempts to discover photojournalists’ views towards credibility. This research draws on qualitative research methods using a largely qualitative questionnaire, which generates both qualitative and quantitative data. The questions are formulated around two case studies of digitally manipulated photographs. The trends and responses in the research data are connected and discussed. The findings of this study are discussed in terms of credibility, awareness of the digital changes, the reason for the changes, the role of a caption, deletion techniques and background changes. The empirical situation is analysed in relation to the theoretical discussions and this study’s theorisation of photographic representation.
- Full Text:
- Date Issued: 2000
- Authors: Làzaro, Angelique Maria
- Date: 2000
- Subjects: Photojournalism -- Moral and ethical aspects , Digital media , Photojournalists , Photography -- Digital techniques
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3451 , http://hdl.handle.net/10962/d1002905 , Photojournalism -- Moral and ethical aspects , Digital media , Photojournalists , Photography -- Digital techniques
- Description: South African photojournalists’ perception of digital technology’s impact on the credibility of news photographs is investigated in this study. Digital technology has the capabilities to produce “manipulated” photographs that appear realistic and credible. Credibility is dependent on a variety of factors including codes of realism and codes of production, which fit conventional codes of photographic representation. Manipulation is the act of deviating from accepted codes of photographic representation that may jeopardise the credibility of news photography. This thesis proposes a new theoretical framework that encompasses existing theories of semiotics, ideology, naturalism, realism and credibility. These theories underpin the definitions and discussion on manipulation and credibility. A descriptive survey is used which attempts to discover photojournalists’ views towards credibility. This research draws on qualitative research methods using a largely qualitative questionnaire, which generates both qualitative and quantitative data. The questions are formulated around two case studies of digitally manipulated photographs. The trends and responses in the research data are connected and discussed. The findings of this study are discussed in terms of credibility, awareness of the digital changes, the reason for the changes, the role of a caption, deletion techniques and background changes. The empirical situation is analysed in relation to the theoretical discussions and this study’s theorisation of photographic representation.
- Full Text:
- Date Issued: 2000
A comparison of the views of South African and American photojournalists to the digital manipulation of news photographs
- Authors: Cass, Taryn May
- Date: 1999
- Subjects: Photojournalists , Photojournalism , Digital media -- Management , Photography -- Digital techniques , Digital media , Photojournalism -- Moral and ethical aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3420 , http://hdl.handle.net/10962/d1002873 , Photojournalists , Photojournalism , Digital media -- Management , Photography -- Digital techniques , Digital media , Photojournalism -- Moral and ethical aspects
- Description: Digital technology has now become pervasive at most publications in South Africa and in America. Pictures are routinely digitised by publications for ease of handling in the layout process, and this makes it relatively easy to alter or manipulate the pictures using computer software programmes. This thesis attempts to gauge the views of South African photojournalists about the digital manipulation of news photographs, and compare these to the views of American photojournalists. It is based on the hypothesis that South African and American photojournalists have different views of what is acceptable manipulation of news photographs, and that their reasons for this will also be different. This thesis also suggests that the manipulation of news photographs is ethically problematic and can damage the credibility of both the photojournalist and the publication in which the photographs appear. The study involves a comparison of the results from a questionnaire given to South African photojournalists and a similar questionnaire given to American photojournalists. The questionnaires were then supplemented by interviews with six South African photojournalists. The thesis then draws conclusions from the responses to the questionnaires and interviews. These conclusions partially support the initial hypothesis, in that there are some differences between the views of South African and American photojournalists, but, on the whole, these are remarkably similar. Photojournalists do seem to find the manipulation of news photographs to be ethically problematic, but they may find the manipulation of other kinds of images (eg fashion or soft news) to be acceptable. South African photographers also find the manipulation of images by other means (eg different lenses or darkroom techniques) to be more acceptable than Americans do. Although the underlying reasons for these views may differ, maintaining the credibility of the photographer and the publication does seem to be the major issue for avoiding digital manipulation. South African photographers seemed to think that if the photographer had done his or her job well, there would be no need for manipulation, and both groups (but especially the Americans) felt that manipulation could often be equated to lying to the reader, and that this might damage their reputation, and that of their publications.
- Full Text:
- Date Issued: 1999
- Authors: Cass, Taryn May
- Date: 1999
- Subjects: Photojournalists , Photojournalism , Digital media -- Management , Photography -- Digital techniques , Digital media , Photojournalism -- Moral and ethical aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3420 , http://hdl.handle.net/10962/d1002873 , Photojournalists , Photojournalism , Digital media -- Management , Photography -- Digital techniques , Digital media , Photojournalism -- Moral and ethical aspects
- Description: Digital technology has now become pervasive at most publications in South Africa and in America. Pictures are routinely digitised by publications for ease of handling in the layout process, and this makes it relatively easy to alter or manipulate the pictures using computer software programmes. This thesis attempts to gauge the views of South African photojournalists about the digital manipulation of news photographs, and compare these to the views of American photojournalists. It is based on the hypothesis that South African and American photojournalists have different views of what is acceptable manipulation of news photographs, and that their reasons for this will also be different. This thesis also suggests that the manipulation of news photographs is ethically problematic and can damage the credibility of both the photojournalist and the publication in which the photographs appear. The study involves a comparison of the results from a questionnaire given to South African photojournalists and a similar questionnaire given to American photojournalists. The questionnaires were then supplemented by interviews with six South African photojournalists. The thesis then draws conclusions from the responses to the questionnaires and interviews. These conclusions partially support the initial hypothesis, in that there are some differences between the views of South African and American photojournalists, but, on the whole, these are remarkably similar. Photojournalists do seem to find the manipulation of news photographs to be ethically problematic, but they may find the manipulation of other kinds of images (eg fashion or soft news) to be acceptable. South African photographers also find the manipulation of images by other means (eg different lenses or darkroom techniques) to be more acceptable than Americans do. Although the underlying reasons for these views may differ, maintaining the credibility of the photographer and the publication does seem to be the major issue for avoiding digital manipulation. South African photographers seemed to think that if the photographer had done his or her job well, there would be no need for manipulation, and both groups (but especially the Americans) felt that manipulation could often be equated to lying to the reader, and that this might damage their reputation, and that of their publications.
- Full Text:
- Date Issued: 1999
Effective application of digital printing techniques for fine artists in the South African context
- Authors: Giloi, Susan Louise
- Date: 1999
- Subjects: Photography -- Digital techniques
- Language: English
- Type: Thesis , Masters , MTech (Photography)
- Identifier: vital:10760 , http://hdl.handle.net/10948/15 , Photography -- Digital techniques
- Description: The question to be answered by this research is how would a fine artist working in South Africa, identify and use the correct digital printing techniques to accurately print their work?
- Full Text:
- Date Issued: 1999
- Authors: Giloi, Susan Louise
- Date: 1999
- Subjects: Photography -- Digital techniques
- Language: English
- Type: Thesis , Masters , MTech (Photography)
- Identifier: vital:10760 , http://hdl.handle.net/10948/15 , Photography -- Digital techniques
- Description: The question to be answered by this research is how would a fine artist working in South Africa, identify and use the correct digital printing techniques to accurately print their work?
- Full Text:
- Date Issued: 1999
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