Search results
- Title
- The impact of climate change and harvest of mountain pine beetle stands on streamflow in northern British Columbia.
- Contributors
- Faye Hirshfield (author), Jueyi Sui (Thesis advisor), University of Northern British Columbia (Degree granting institution)
- Abstract
- This research examines the impact of climate change and MPB harvest on streamflow in northern British Columbia using the Hydrologiska Byr~\u2022ns Vattenbalansmodell-Environment Canada model (HBV-EC) a semi-distributed conceptual hydrologic model. Streamflow for the Goathorn Creek watershed in Telkwa is modeled under the IPCC A1B, A2 and B1 emissions scenarios. The TreeGen downscaling method and four global climate models were used to generate future climate. Global climate models used were the Canadian developed CGCM3, ECHAM5 from Germany, GFDL-CM2.1 from the United States and CSIRO-Mk from Australia. Under all climate scenarios HBV-EC modeled a 16 percent reduction in mean annual flows the timing of spring peak flows was also forecast to occur up to 30 days earlier in the year. A change in the timing of peak flows and an overall reduction in mean flows will have important implications for water managers, domestic users and industrial development within the Bulkley Valley. The HBV-EC model was also used to model Moffat Creek streamflow under various harvest scenarios for mountain pine beetle stands. The model predicted an increase in streamflow with an increase in harvest area. When compared to measured streamflow it was however found that average spring discharge during the MPB epidemic was 14 percent lower than it had been during the previous 30 years. The low spring discharge during the MPB epidemic appeared to be related to the 9 percent decrease in SWE for the same years however further investigation is required.
- Discipline
- Environmental Science
- Content Model
- info:fedora/ir:thesisCModel
- Date added
- 2010
- Title
- Local scour around bridge abutments under ice covered conditions.
- Contributors
- Peng Wu (author), Jueyi Sui (Thesis advisor), University of Northern British Columbia (Degree granting institution)
- Abstract
- Local scour refers to the sediment transport around hydraulic structures by flowing water. Excessive scour around the abutment can potentially cause damage to the bridge, which may also result in catastrophic consequences. Abutment scour refers to the local scour generated by the flow passing around bridge abutments. One of the challenging problems for hydraulic engineers is the prediction of maximum scour depth around abutments and pier foundations so that proper provisions can be made in the design and construction to mitigate the consequences. Despite significant research efforts to improve the understanding of scour related problems, abutment scour is still among the more complex and challenging problems. Over the past few decades, local scour around bridge abutments has received wide attention, and many researchers have contributed various studies on the topic. The current state knowledge on local scour still has insufficiently understood aspects, for example, ice accumulation has never been addressed in the abutment scour research. The impacts of ice cover has never been conducted. To fill this gap, the present research is conducted. The ice cover can change the channel morphology and flow field. It is well known that river ice affects the vertical and lateral distribution of flow in a channel. Additionally, because river ice affects the flow conditions, it potentially influence sediment transport. Hence, the scour around abutments is affected. In the present research, a series of large flume experiments are conducted. By adding different simulated ice covers in the flume, ice-covered flow can be generated. By comparing the scour profiles and maximum scour depth around two commonly used abutments in three non-uniform sediments, the ice cover impacts have been investigated. A significant increase can be noticed by adding ice cover. With the increase in ice cover roughness, the maximum scour depth increase correspondingly. Meanwhile, semi-circular abutment can generate a relatively small scour hole. Further
- Discipline
- Natural Resources & Environmental Studies
- Content Model
- info:fedora/ir:thesisCModel
- Date added
- 2015
- Title
- The impact of climate change and harvest of mountain pine beetle stands on streamflow in northern British Columbia
- Contributors
- Faye Hirshfield (author), Jueyi Sui (Thesis advisor), University of Northern British Columbia (Degree granting institution)
- Abstract
- This research examines the impact of climate change and MPB harvest on streamflow in northern British Columbia using the Hydrologiska Byråns Vattenbalansmodell-Environment Canada model (HBV-EC) a semi-distributed conceptual hydrologic model. Streamflow for the Goathorn Creek watershed in Telkwa is modeled under the IPCC A1B, A2 and B1 emissions scenarios. The TreeGen downscaling method and four global climate models were used to generate future climate. Global climate models used were the Canadian developed CGCM3, ECHAM5 from Germany, GFDL-CM2.1 from the United States and CSIRO-Mk from Australia. Under all climate scenarios HBV-EC modeled a 16 percent reduction in mean annual flows the timing of spring peak flows was also forecast to occur up to 30 days earlier in the year. A change in the timing of peak flows and an overall reduction in mean flows will have important implications for water managers, domestic users and industrial development within the Bulkley Valley. The HBV-EC model was also used to model Moffat Creek streamflow under various harvest scenarios for mountain pine beetle stands. The model predicted an increase in streamflow with an increase in harvest area. When compared to measured streamflow it was however found that average spring discharge during the MPB epidemic was 14 percent lower than it had been during the previous 30 years. The low spring discharge during the MPB epidemic appeared to be related to the 9 percent decrease in SWE for the same years however further investigation is required.
- Discipline
- Environmental Science
- Content Model
- info:fedora/ir:thesisCModel
- Date added
- 2010
- Title
- Development of fuzzy multi-criteria decision analysis approach for contaminated site management.
- Contributors
- Mohammad Habibur Rahman (author), Jianbing Li (Thesis advisor), Jueyi Sui (Thesis advisor), University of Northern British Columbia (Degree granting institution)
- Abstract
- Selection of a proper remediation alternative is an important task in the decision making process of contaminated site management. The number of available remediation alternatives is increasing over the years as a result of perpetual development in scientific research. Decision makers face a confounded situation to select the best acceptable alternative by satisfying various preferences of different stakeholders (e.g., industry, government, public_. In this research, a fuzzy multi-criteria decision analysis (FMCDA) approach was developed. Since most information available in the decision making process is not deterministic, fuzzy-set theory was used to deal with such uncertainty. The developed FMCDA approach ranks the candidate alternatives according to the utility value which then assists decision makers in selecting more proper remediation options. Different stakeholders' opinions were effectively incorporated in the developed approach, allowing for a robust decision making for contaminated site management. A user friendly decision support system based on the FMCDA approach was also developed in this research. The developed method was then applied to the management of a site in northern British Columbia to examine its applicability. As well, existing multi-criteria decision making methods were also applied to the remediation selection of this site. The results suggest that the developed FMCDA method is more capable of considering uncertainty issues and it is a helpful means of integrating various interests from different stakeholders.
- Discipline
- Environmental Science
- Content Model
- info:fedora/ir:thesisCModel
- Date added
- 2008