Dynamics of permafrost submitted to a warning climate

警告气候下的永久冻土动态

• 批准号: 371764-2009
• 负责人: Fortier, Daniel
• 金额: $ 1.24万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=461362
• 关键词: Dynamics; permafrost; submitted; warning; climate

Permafrost covers about 45% of Canada and therefore Northern landscape evolution is highly dependent on the dynamics of permafrost aggradation and degradation through time. Climatic changes play a key role in the dynamics of permafrost. Changing temperature, precipitation and sedimentary regimes affect the thermal state and the mechanics of permafrost. On the long term, the projected climate warming scenarios for Northern Canada suggest that the permafrost will be markedly affected. These changes will have a profound impact on northern ecosystems via changes in the physical environment and the hydrological cycle. Where the ground is ice-rich the adjustment of the permafrost to climatic conditions will induce thermokarst and thermo-erosion processes related to erosion, ground ice melting, thaw-settlement and mass movement of the surface. These natural processes will be further exacerbated by human activities. In the recent decades, Northern permafrost regions of Canada have experienced a sustained growth and are expected to undergo a tremendous development in the near future. Population growth, as well as oil, gas and mining exploration require the construction of additional roads, railways, airstrips and pipelines which create heavy pressures on the environment. The construction of infrastructures inevitably affects the thermal regime of the underlying permafrost through disturbance of the surface. Recurrent maintenance operations, rehabilitation, reconstruction and relocalization of damaged infrastructures will become very costly. This general objective of this research program is to answer pressing questions of permafrost degradation in natural settings and applied to transport infratsructures. This research program proposes to adopt a field-based geomorphological approach to study the fundamentals of permafrost degradation processes on various time scales (year to decades) and to develop engineering techniques to prevent permafrost degradation and to rehabilitate (re-freeze) thawed permafrost. This research program will help Canadian communities, governments and the industry to develop science-based adaptation strategies to cope with warming and changing permafrost environments.

永久冻土覆盖了加拿大约45％，因此北部景观的演变高度依赖于随着时间的推移多年冻土促进和降解的动态。气候变化在多年冻土的动态中起着关键作用。温度，降水和沉积物的变化会影响热状态和多年冻土的力学。从长远来看，加拿大北部的预计气候变暖方案表明，永久冻土将受到显着影响。这些变化将通过物理环境和水文周期的变化对北部生态系统产生深远的影响。如果地面是冰的含水，则对气候条件的多年冻土的调整将诱导与侵蚀，地面冰融化，解冻和表面质量运动有关的热力学和热渗透过程。 人类活动将进一步加剧这些自然过程。在近几十年中，加拿大北部的佛罗斯特郡地区经历了持续的增长，并有望在不久的将来经历巨大的发展。人口增长以及石油，天然气和采矿勘探需要建造其他道路，铁路，飞机和管道，从而在环境上造成巨大的压力。基础设施的构建不可避免地会通过表面干扰来影响基本冻土的热度状态。经常性维护操作，康复，重建和损害基础设施的重新定位将非常昂贵。 该研究计划的这一总体目标是回答自然环境中多年冻土降解的问题，并应用于运输侵蚀。该研究计划建议采用一种基于现场的地貌方法来研究各种时间尺度（年至数十年）上的多年冻土降解过程的基础，并开发工程技术以防止多年冻土降解并康复（重新冻结）冻结的多年冻土。 该研究计划将帮助加拿大社区，政府和行业制定基于科学的适应策略，以应对变暖和变化的多年冻土环境。