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 assessment of the formulation of permit conditions associated with environmental authorisations and implications for compliance monitoring
- Authors: Jennings, Patricia Jean
- Date: 2011
- Subjects: Environmental impact analysis , Environmental management , Economic development projects , Licenses , Environmental monitoring , Compliance -- Environmental aspects , Environmental policy
- Language: English
- Type: Thesis , Masters , MPhil (Environmental Studies)
- Identifier: vital:11873 , http://hdl.handle.net/10353/437 , Environmental impact analysis , Environmental management , Economic development projects , Licenses , Environmental monitoring , Compliance -- Environmental aspects , Environmental policy
- Description: Environmental impact assessment is a widely accepted planning tool used in environmental management. Internationally it has been adopted as a formal permitting requirement for development projects in many jurisdictions. Historically the focus has been on the pre-decision making stages of environmental impact assessment. It has, however, been widely acknowledged that post-decision environmental impact assessment follow-up is an important component in confirming initial predictions, enabling responsible adaptive management of environmental impacts and ensuring compliance with permit conditions. It is this last function which is the focus of this study. Specifically, the role of permit conditions in enabling compliance and facilitating compliance monitoring is addressed. Permit conditions of twenty-one environmental authorisations were examined and tested for conformance with legislated requirements, and practicality of monitoring for compliance (monitorability). It was found that there are many contributors to achieving monitorable permit conditions. Amongst the most significant of these are conformity in interpretation of the regulations specifying permit content by officials, gaps in guidance on the part of the regulations themselves, and a tendency to focus on construction related impacts. The lack of clarity regarding the roles and functions of environmental control officer and environmental auditor further contribute to poor monitorability of permit conditions. Specific areas of shortcoming and best practice in the permit conditions analysed were identified and discussed. Finally, recommendations are made for the improvement of permit condition monitorability.
- Full Text:
- Date Issued: 2011
- Authors: Jennings, Patricia Jean
- Date: 2011
- Subjects: Environmental impact analysis , Environmental management , Economic development projects , Licenses , Environmental monitoring , Compliance -- Environmental aspects , Environmental policy
- Language: English
- Type: Thesis , Masters , MPhil (Environmental Studies)
- Identifier: vital:11873 , http://hdl.handle.net/10353/437 , Environmental impact analysis , Environmental management , Economic development projects , Licenses , Environmental monitoring , Compliance -- Environmental aspects , Environmental policy
- Description: Environmental impact assessment is a widely accepted planning tool used in environmental management. Internationally it has been adopted as a formal permitting requirement for development projects in many jurisdictions. Historically the focus has been on the pre-decision making stages of environmental impact assessment. It has, however, been widely acknowledged that post-decision environmental impact assessment follow-up is an important component in confirming initial predictions, enabling responsible adaptive management of environmental impacts and ensuring compliance with permit conditions. It is this last function which is the focus of this study. Specifically, the role of permit conditions in enabling compliance and facilitating compliance monitoring is addressed. Permit conditions of twenty-one environmental authorisations were examined and tested for conformance with legislated requirements, and practicality of monitoring for compliance (monitorability). It was found that there are many contributors to achieving monitorable permit conditions. Amongst the most significant of these are conformity in interpretation of the regulations specifying permit content by officials, gaps in guidance on the part of the regulations themselves, and a tendency to focus on construction related impacts. The lack of clarity regarding the roles and functions of environmental control officer and environmental auditor further contribute to poor monitorability of permit conditions. Specific areas of shortcoming and best practice in the permit conditions analysed were identified and discussed. Finally, recommendations are made for the improvement of permit condition monitorability.
- Full Text:
- Date Issued: 2011
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