Wildfire and vegetation impacts on sediment transport and hillslope evolution in mountain landscapes

野火在加拿大的许多地方都是一个严重的危害，当大火蔓延到定居点和发达地区时，会造成特别严重的威胁。近年来发生的严重野火突出表明，有必要进一步了解野火是如何引发、蔓延和影响环境的。尽管野火给人类带来危险，但它们是一种自然形式的干扰，是环境的重要组成部分；生态系统和野生动物已经适应并依赖野火的发生。随着森林地面燃料的积累，扑灭野火不仅可能增加未来火灾的严重程度，而且还会破坏自然生态系统的运作。需要更好地了解野火行为和火灾后对自然系统的影响，以确保采取健全的管理战略。野火可能导致地面植被和/或树木死亡，并可能改变土壤化学，从而减少水分渗入土壤。因此，陆地表面以下和地表以上以及河流中的水流运动可能发生变化。这些变化可能导致土壤侵蚀和/或滑坡加剧，从而增加河流中的泥沙负荷。这些变化可能对水质和鱼类栖息地产生不利影响。滑坡率的增加也对人类住区和基础设施构成威胁。此外，由于温室效应变暖，野火的发生与气候变化之间存在很强的联系，某些地区的火灾活动和严重程度可能会增加。这项研究的任务是更好地了解野火对自然系统运行的影响。这项工作通过实地调查考虑了加拿大落基山脉的火灾后侵蚀。此外，还利用数值模拟方法评估了景观对未来气候变化的响应以及与野火状况相关的变化。从事这项工作的研究小组将产生非常重要的结果，这将对科学界和考虑火灾后侵蚀的环境管理人员有价值。结果还将提供更长时间尺度的自然、火灾后侵蚀过程的基线信息，并允许对景观进行战略性的长期管理。

Wildfire is a serious hazard in many parts of Canada, posing a particularly significant threat when fires spread to settlements and developed locations. Severe wildfires in recent years have highlighted the necessity for improved understanding of how wildfires initiate, spread and impact the environment. Despite the hazard they present to humans, wildfires are a natural form of disturbance and are a critical part of the environment; ecosystems and wildlife have adapted to and rely on wildfire occurrence. Wildfire suppression may not only increase the severity of future fires as fuels on the forest floor accumulate, but it disrupts natural ecosystem operation. Improved understanding of wildfire behaviour and post-fire effects on natural systems is required to ensure sound management strategies are adopted. Wildfires may lead to death of ground vegetation and/or trees, and may modify soil chemistry, thereby decreasing water infiltration into soils. As a consequence, modifications to water movement below and above the land surface, and in rivers, may occur. These changes may lead to increased soil erosion and/or landsliding, and thereby increase sediment loads in rivers. Such changes may adversely impact water quality and fish habitat. Increased landsliding rates also present a hazard to human settlements and infrastructure. In addition, strong connections exist between wildfire occurrence and climate change due to greenhouse warming, with the possibility of increased fire activity and severity in certain regions. The mission of this research is to better understand impacts of wildfire on natural system operation. This work considers post-fire erosion in the Canadian Rockies through field-based investigations. In addition, landscape response to future climate change and associated modifications to wildfire regimes is assessed using numerical modelling simulations. The research team undertaking this work will produce highly significant results, that will be valuable to the scientific community and to environmental managers considering post-fire erosion. Results will also provide baseline information about natural, post-fire erosional processes over longer times scales, and allow for strategic, long-term management of landscapes.