Shallow bedrock aquifers are prevalent across the Northern Hemisphere and can be the primary source of freshwater for many communities. Cryospheric impacts from climate warming are particularly concerning for bedrock aquifers where recharge is dominated by winter precipitation. For the management and protection of fractured rock groundwater supplies, the processes influencing infiltration and recharge under warmer winter conditions require a greater understanding. As such, a numerical investigation was undertaken with the objective of testing a conceptual model of midwinter infiltration and recharge near a granitic Canadian Shield bedrock outcrop using data collected over an unseasonably warm and rainy winter in eastern Ontario, Canada. Additional objectives were to determine if infiltration and recharge would be limited through frozen soils without an outcrop and to explore the hydrologic implications of an additional midwinter snowmelt event. Results supported the concept that outcrops provide preferential infiltration along the soil-rock interface at outcrop margins, which enables localized bedrock recharge under frozen conditions. To simulate soil moisture content near the outcrop, bedrock runoff was needed as additional lateral input in the lower soil profile (75 cm). The amount of runoff required as input was controlled by the hydraulic conductivity of the soil-rock interface. In the absence of an outcrop, limited midwinter infiltration occurs due to reduced permeabilities of frozen soils from repeated early winter rainfall and snowmelt events. Additional midwinter melt events can likely increase bedrock recharge, but the associated decline in snow depth deepens soil frost which delays further infiltration and increases surface runoff. Simulations suggest winter is becoming a more active time for bedrock recharge where outcrops are present, but wetter conditions have implications for frozen soil permeability. Findings extend to similar seasonally frozen bedrock environments which are relied on as a source of freshwater and are rapidly changing under a warming climate.

浅基岩含水层在北半球普遍存在，可以成为许多社区淡水的主要来源。气候变暖对冰冻圈的影响对于补给以冬季降水为主的基岩含水层尤为重要。对于裂隙岩石地下水供应的管理和保护，在温暖的冬季条件下影响入渗和补给的过程需要更多的了解。因此，进行了一项数值调查，目的是使用在加拿大安大略省东部异常温暖和多雨的冬季收集的数据，在花岗岩加拿大地盾基岩露头附近测试隆冬入渗和补给的概念模型。其他目标是确定通过没有露头的冻土是否会限制渗透和补给，并探索额外的隆冬融雪事件的水文影响。结果支持了露头沿露头边缘的土壤 - 岩石界面提供优先渗透的概念，这使得在冻结条件下局部基岩补给成为可能。为了模拟露头附近的土壤水分含量，需要基岩径流作为下部土壤剖面（75 厘米）的额外横向输入。作为输入所需的径流量由土壤-岩石界面的水力传导率控制。在没有露头的情况下，由于反复的初冬降雨和融雪事件导致冻土的渗透性降低，因此会发生有限的仲冬入渗。额外的隆冬融化事件可能会增加基岩补给，但相关的积雪深度下降会加深土壤霜冻，从而延迟进一步渗透并增加地表径流。模拟表明，冬季正成为存在露头的基岩补给的更加活跃的时期，但较潮湿的条件对冻土的渗透性有影响。研究结果延伸到类似的季节性冰冻基岩环境，这些环境被视为淡水的来源，并且在气候变暖的情况下正在迅速变化。但潮湿的条件对冻土的渗透性有影响。研究结果延伸到类似的季节性冰冻基岩环境，这些环境被视为淡水的来源，并且在气候变暖的情况下正在迅速变化。但潮湿的条件对冻土的渗透性有影响。研究结果延伸到类似的季节性冰冻基岩环境，这些环境被视为淡水的来源，并且在气候变暖的情况下正在迅速变化。