Among the few positive impacts of climate warming in cold regions, permafrost degradation can increase the availability of groundwater as a potential source of drinking water for northern communities. Near the Inuit community of Umiujaq in Nunavik, Canada, a watershed in a valley in the discontinuous permafrost zone was instrumented to monitor the impacts of climate change on permafrost and groundwater, and assess the groundwater availability and quality. Based on Quaternary chronology, knowledge of periglacial processes, and an investigation carried out in the valley (including mapping of Quaternary deposits and ice-rich permafrost distribution, drilling and sampling of deposits, and geophysical surveys), a three-dimensional (3D) geological model of the watershed was built into GoCAD to assess the hydrogeological context in this degrading permafrost environment. In total, six units were identified within the watershed including an upper aquifer in marine sediments, a lower aquifer at depth in glaciofluvial and glacial sediments, and the bedrock acting as a low-permeability boundary. An aquitard, made of frost-susceptible silty sand and discontinuously invaded by ice-rich permafrost, confines the lower aquifer. This 3D geological model clarifies the local stratigraphic architecture and geometries of Quaternary deposits, especially the stratigraphic relationship between the two aquifers, aquitard, and bedrock, and the extent of ice-rich permafrost within the watershed. It is the cornerstone to understand the groundwater dynamics within the watershed and to carry out numerical modelling of coupled groundwater flow and heat transfer processes to predict the impacts of climate change on groundwater resources in this degrading permafrost environment.

在寒冷地区气候变暖带来的一些积极影响中，多年冻土退化可以增加地下水的供应量，从而成为北部社区的潜在饮用水源。在加拿大努纳维克Umiujaq因纽特人社区附近，不连续多年冻土带山谷中的一个分水岭被用来监测气候变化对多年冻土和地下水的影响，并评估地下水的可利用性和质量。基于第四纪年代学，了解冰川过程，并在山谷中进行了调查（包括第四纪沉积物的绘制和富含冰的多年冻土分布，沉积物的钻孔和采样以及地球物理调查），GoCAD中建立了流域的三维（3D）地质模型，以评估在这种退化的多年冻土环境中的水文地质情况。流域内总共确定了六个单元，包括海洋沉积物中的上含水层，冰川河流和冰川沉积物中深处的下含水层以及作为低渗透性边界的基岩。由易受霜冻的粉砂制成的无水玻璃，不连续地被富含冰的永久冻土侵入，限制了下含水层。该3D地质模型阐明了第四纪沉积物的局部地层构造和几何形状，尤其是两个含水层，阿奎塔尔岩和基岩之间的地层关系，以及流域内富冰的多年冻土的范围。