Infiltration and near surface water flow in seasonally frozen landscapes

这项研究计划旨在提高我们对季节性冻土中入渗和近地表水运动的了解，以便更好地量化和管理我们的水资源。近地表环境通常被称为“临界区”，因为水、空气和土壤之间存在着维持生命的复杂相互作用。在经历季节性冻融循环的加拿大等地区，许多临界区过程都发生了独特的变化。水进入(称为入渗)和穿过部分冻结的土壤的能力经常发生巨大变化，很难预测。鉴于该区域的水流最终决定了河流流量的大小和时间、地下水的补给和污染物的移动，我们必须了解冰冻地区的水流运动，以便可持续地管理这一宝贵资源。新颖的实验室和实地实验将填补我们在理解冻土水文学方面的关键空白，包括控制融雪事件(仲冬和春季融化)期间水运动的重要过程，以及这些过程在空间和时间上的变异性。为了实现最大效益，这项研究将侧重于知之甚少的水文过程，如地面融化期间的快速水运动和不同土地覆盖和地形环境下的复杂反馈机制。所获得的科学知识将被用来建立更现实的数值(计算机)模型，以量化临界区内的水运动。这些使用前沿数值工具开发的模型将与新获得的数据进行测试，以确保预测的真实性。这项研究将立即应用于评估径流和地下水补给以融雪为主的广大地区的水文流量。水资源管理者和用户将受益于预测地表和地下流量的新工具(例如洪水预报、地下水补给)，从而能够更可持续地管理水资源。从长远来看，这些发现将产生更准确的水文模型，从而更好地预测和缓解气候变化和土地利用变化对脆弱、季节性冻结地貌的不利影响。

This research program aims to improve our understanding of infiltration and near surface water movement in seasonally frozen ground, in order to better quantify and manage our water resources. The near surface environment is often termed the “critical zone” due to the complex interactions involving water, air, and soil that sustain life. Many critical zone processes are uniquely altered in regions, such as Canada, that experience seasonal freeze-thaw cycles. The ability of water to move into (termed infiltration) and through partially frozen soils is often dramatically altered and difficult to predict. Given that water flow in this zone ultimately governs the magnitude and timing of river flows, groundwater replenishment, and contaminant movement, it is crucial that we understand water movement in frozen landscapes in order to sustainably manage this valuable resource. Novel laboratory and field experiments will fill in key gaps in our understanding of frozen ground hydrology, including the important processes controlling water movement during snowmelt events (both mid-winter and spring melts) and the variability of these processes in space and time. To achieve maximal benefit, the research will focus on poorly understood hydrologic processes, such as rapid water movement during ground thaw and complex feedback mechanisms in different land cover and terrain settings. The scientific knowledge gained will be used to build more realistic numerical (computer) models for quantifying water movement in the critical zone. The models, developed using leading edge numerical tools, will be tested against the newly acquired data to ensure realistic predictions. The research will have immediate application for evaluating hydrologic flows in the vast regions where runoff and groundwater recharge are dominated by snowmelt. Water managers and users will benefit from new tools for predicting surface and subsurface flows (e.g., flood forecasting, groundwater recharge), enabling more sustainable management of water resources. In the long term, the findings will generate more accurate hydrologic models, leading to better prediction and mitigation of adverse impacts from changing climate and land-use in vulnerable, seasonally frozen landscapes.