Numerical study of mining activity and climate change impact on permafrost in Northern Canada
The presence of permafrost and its susceptibility to naturally freeze and thaw under changes in the environment is a major problem in cold regions encompassing nearly 50% of Canada land surface. The excavation of open pit mines in permafrost with subsequent filling with tailings and water presents a...
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Online Access: | http://hdl.handle.net/11023/3780 https://doi.org/10.11575/PRISM/27145 |
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ftunivcalgary:oai:prism.ucalgary.ca:11023/3780 2023-08-27T04:11:14+02:00 Numerical study of mining activity and climate change impact on permafrost in Northern Canada Booshehrian, Ahmad Wan, Richard 2017 application/pdf http://hdl.handle.net/11023/3780 https://doi.org/10.11575/PRISM/27145 eng eng Graduate Studies University of Calgary Calgary Booshehrian, A. (2017). Numerical study of mining activity and climate change impact on permafrost in Northern Canada (Unpublished doctoral thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/27145 http://dx.doi.org/10.11575/PRISM/27145 http://hdl.handle.net/11023/3780 University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Engineering--Civil Permafrost Talik Climate Change doctoral thesis 2017 ftunivcalgary https://doi.org/10.11575/PRISM/27145 2023-08-06T06:27:58Z The presence of permafrost and its susceptibility to naturally freeze and thaw under changes in the environment is a major problem in cold regions encompassing nearly 50% of Canada land surface. The excavation of open pit mines in permafrost with subsequent filling with tailings and water presents a scenario similar to a thermokarst lake that causes a local drift from ground temperatures, thus resulting in talik formation. This thesis is concerned with the numerical analysis of permafrost degradation and its consequences within the permafrost zone due to mining activities and climate change. The Kiggavik uranium mine project in Nunavut, Canada where four open pit mines will be excavated into deep permafrost is chosen as a case study for which extensive data is publicly available. Incrementally complex hydro-thermal models were developed within the finite element framework. Short-term studies indicate that for different considered scenarios during the mine operation period drastic changes are not expected. Open taliks will not form in the smaller pits. Ground deformations due to high in-situ stresses and high ground water pressure will be less than 100 mm. The presence of faulted zones enhances the water inow into open excavations; however, the water level variation within the pits is less than 2 cm/day. The long-term simulations demonstrate that after 2000 years, with no-climate change scenario, the permafrost could only be recovered within the smallest pit. The permafrost thickness decreases to approximately 35m considering a probable climate change scenario. In the case of a severe scenario, the permafrost disappears completely in about 700 years, and the water table will rise to 35m below ground surface. The inuence of material hydraulic properties is examined with introduction of a new analytical method. Decreasing the fractures mean aperture in the rock domains accelerates permafrost thawing up to 100 years in some locations. Doctoral or Postdoctoral Thesis Nunavut permafrost Thermokarst PRISM - University of Calgary Digital Repository Canada Nunavut Talik ENVELOPE(146.601,146.601,59.667,59.667) |
institution |
Open Polar |
collection |
PRISM - University of Calgary Digital Repository |
op_collection_id |
ftunivcalgary |
language |
English |
topic |
Engineering--Civil Permafrost Talik Climate Change |
spellingShingle |
Engineering--Civil Permafrost Talik Climate Change Booshehrian, Ahmad Numerical study of mining activity and climate change impact on permafrost in Northern Canada |
topic_facet |
Engineering--Civil Permafrost Talik Climate Change |
description |
The presence of permafrost and its susceptibility to naturally freeze and thaw under changes in the environment is a major problem in cold regions encompassing nearly 50% of Canada land surface. The excavation of open pit mines in permafrost with subsequent filling with tailings and water presents a scenario similar to a thermokarst lake that causes a local drift from ground temperatures, thus resulting in talik formation. This thesis is concerned with the numerical analysis of permafrost degradation and its consequences within the permafrost zone due to mining activities and climate change. The Kiggavik uranium mine project in Nunavut, Canada where four open pit mines will be excavated into deep permafrost is chosen as a case study for which extensive data is publicly available. Incrementally complex hydro-thermal models were developed within the finite element framework. Short-term studies indicate that for different considered scenarios during the mine operation period drastic changes are not expected. Open taliks will not form in the smaller pits. Ground deformations due to high in-situ stresses and high ground water pressure will be less than 100 mm. The presence of faulted zones enhances the water inow into open excavations; however, the water level variation within the pits is less than 2 cm/day. The long-term simulations demonstrate that after 2000 years, with no-climate change scenario, the permafrost could only be recovered within the smallest pit. The permafrost thickness decreases to approximately 35m considering a probable climate change scenario. In the case of a severe scenario, the permafrost disappears completely in about 700 years, and the water table will rise to 35m below ground surface. The inuence of material hydraulic properties is examined with introduction of a new analytical method. Decreasing the fractures mean aperture in the rock domains accelerates permafrost thawing up to 100 years in some locations. |
author2 |
Wan, Richard |
format |
Doctoral or Postdoctoral Thesis |
author |
Booshehrian, Ahmad |
author_facet |
Booshehrian, Ahmad |
author_sort |
Booshehrian, Ahmad |
title |
Numerical study of mining activity and climate change impact on permafrost in Northern Canada |
title_short |
Numerical study of mining activity and climate change impact on permafrost in Northern Canada |
title_full |
Numerical study of mining activity and climate change impact on permafrost in Northern Canada |
title_fullStr |
Numerical study of mining activity and climate change impact on permafrost in Northern Canada |
title_full_unstemmed |
Numerical study of mining activity and climate change impact on permafrost in Northern Canada |
title_sort |
numerical study of mining activity and climate change impact on permafrost in northern canada |
publisher |
Graduate Studies |
publishDate |
2017 |
url |
http://hdl.handle.net/11023/3780 https://doi.org/10.11575/PRISM/27145 |
long_lat |
ENVELOPE(146.601,146.601,59.667,59.667) |
geographic |
Canada Nunavut Talik |
geographic_facet |
Canada Nunavut Talik |
genre |
Nunavut permafrost Thermokarst |
genre_facet |
Nunavut permafrost Thermokarst |
op_relation |
Booshehrian, A. (2017). Numerical study of mining activity and climate change impact on permafrost in Northern Canada (Unpublished doctoral thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/27145 http://dx.doi.org/10.11575/PRISM/27145 http://hdl.handle.net/11023/3780 |
op_rights |
University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. |
op_doi |
https://doi.org/10.11575/PRISM/27145 |
_version_ |
1775353850457227264 |