Understanding the impacts of permafrost thaw on surface water flux and storage

加拿大西北部的亚北极地区是地球上变暖最快的地区之一。该地区的永久冻土正在以前所未有的速度融化，对道路、简易机场、渡口、管道和建筑物造成了破坏，同时改变了土地覆盖，扰乱了水循环。例如，在西北地区南部以泥炭为主的不连续永久冻土地区，永久冻土融化正在将大片森林变成湿地，使湿地枯竭，溪流和河流流量上升。考虑到土地覆盖特性强烈影响水的流动和储存过程，而且永久冻土是该区域大部分土地覆盖的基础，永久冻土的融化和消失对该区域的水循环具有深远的影响。然而，监管当局、资源管理委员会和社区在有效应对这一新的和日益增长的挑战方面装备不足，因为该区域几乎没有或根本没有冻土融化监测、适应或预测能力，因此没有适当的决策支持依据。因此，迫切需要调查融化引起的土地和水的变化，开发和调动关于这些变化的知识，开发预测模型工具，并为决策者和其他利益攸关方提供互动培训。作为直接回应，这一研究方案将(与土著社区和其他北方最终用户)共同开发和实施关于永久冻土分布、融化、融化引起的土地覆盖变化和由此产生的水文影响的新知识；此外，还将提供高质量的公共数据集、基于知识的定制预测工具和创新的适应和风险管理战略。每一项都将进行定制，以满足研究区域的专门决策支持需求，以便能够自信地应用环境和资源管理战略。预计这一研究方案的产品也将广泛适用于环北极次北极地区。

The subarctic region of north-western Canada is one of the most rapidly warming on Earth. The permafrost of this region is thawing at unprecedented rates causing damage to roads, air strips, ferry crossings, pipelines, and buildings, while transforming land covers and disrupting the water cycle. For example, in the peatland-dominated region of discontinuous permafrost in the southern Northwest Territories, permafrost thaw is transforming large areas of forest into wetland, enabling wetlands to drain, and the flow of streams and rivers to rise. Considering that land cover characteristics strongly affect water flow and storage processes, and that permafrost is the foundation of much of the land cover in this region, the thaw and disappearance of permafrost has profound implications for the region's water cycle. However, regulatory authorities, resource management boards, and communities are ill-equipped to respond effectively to this new and growing challenge, because there is little or no permafrost thaw monitoring, adaptation or predictive capacity in the region, and therefore no appropriate basis for decision support. As a result, there is an urgent need to investigate thaw-induced changes to land and water, develop and mobilise knowledge on these changes, develop predictive modelling tools, and provide interactive training to decision makers and other stakeholders. In direct response, this research programme will co-develop and co-implement (with Indigenous communities and other northern end-users) new knowledge on permafrost distribution, thaw, thaw-induced land cover change, and resulting hydrological impacts; in addition to high-quality public data sets, and customised knowledge-based predictive tools and innovative adaptation and risk management strategies. Each of these will be customised to meet the specialised decision support needs of the study region so that environmental and resource management strategies can be confidently applied. It is expected that the products of this research programme will also have wide applicability throughout the circumpolar subarctic.