Infiltration and near surface water flow in seasonally frozen landscapes

本研究项目旨在提高我们对季节性冻土的渗透和近地表水运动的理解，以便更好地量化和管理我们的水资源。由于维持生命的水、空气和土壤的复杂相互作用，近地表环境通常被称为“临界区”。在加拿大等经历季节性冻融循环的地区，许多关键的区域过程发生了独特的变化。水进入（称为渗透）和通过部分冻结土壤的能力经常发生巨大变化，难以预测。考虑到这一区域的水流最终决定了河流流量的大小和时间、地下水补给和污染物的运动，为了可持续地管理这一宝贵的资源，我们了解冰冻景观中的水运动是至关重要的。新的实验室和实地实验将填补我们对冻土水文学理解的关键空白，包括融雪事件（冬季中期和春季融雪）期间控制水运动的重要过程以及这些过程在空间和时间上的变化。为了获得最大的效益，研究将集中在尚不清楚的水文过程上，如在不同的土地覆盖和地形环境下，地面融化过程中的快速水运动和复杂的反馈机制。所获得的科学知识将用于建立更现实的数值（计算机）模型，以量化临界带的水运动。使用前沿数值工具开发的模型将针对新获得的数据进行测试，以确保预测的真实性。该研究将立即应用于评估以融雪为主要径流和地下水补给的广大地区的水文流量。水的管理者和使用者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），从而实现更可持续的水资源管理。从长远来看，这些发现将产生更准确的水文模型，从而更好地预测和减轻气候变化和土地利用对脆弱的季节性冻结景观的不利影响。

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.