Pleistocene-aged glacial sediments are found in many parts the Northern Hemisphere and are often composed of clay-rich tills which form aquitards that can control drainage and influence groundwater movement and contaminant transport. Site-scale investigations have characterized the hydraulic properties of till aquitards; however, the hydraulic conductivity of these units has not been quantitatively described at a regional scale of tens of kilometers. This study constrains regionally representative hydraulic conductivity estimates and characterizes the hydrogeological properties of Pleistocene-aged till aquitards from data collected at 15 sites compiled from 21 studies. The data quantify the scale dependence of hydraulic conductivity measurements in till aquitards and further define the relationship between hydraulic conductivity and depth. Data from centimeter-scale laboratory tests remained generally constant with depth, with a geometric mean hydraulic conductivity of 7.0 × 10⁻¹¹ m/s and a standard deviation of 0.4 orders of magnitude, while the meter-scale in-situ tests had a geometric mean of 4.9 × 10⁻⁹ m/s and a standard deviation of 1.0 orders of magnitude at depths less than 10 m, and 3.7 × 10⁻¹¹ m/s and 0.2 order of magnitude at depths greater than 23 m. The results support the existence of a shallow fractured zone of higher hydraulic conductivity and a deeper zone characterized by matrix permeability. The observed data variability occurred primarily at the site scale, while the central tendency and variability of the data were consistent between sites separated by hundreds of kilometers suggesting that statistically derived, depth-defined regional hydraulic conductivity estimates can be meaningful.

在北半球的许多地方都发现了更新世时期的冰川沉积物，这些沉积物通常由富含粘土的耕作组成，这些耕作形成了可以控制排水并影响地下水运动和污染物迁移的阿奎塔德。现场规模的调查已经表征了till菜的水力特性。然而，这些装置的水力传导率尚未在数十公里的区域范围内进行定量描述。这项研究限制了地区代表性的水力传导率估算值，并根据从21项研究中收集的15个站点收集的数据，表征了更新世至水生年龄的水文地质特性。数据量化了水力传导率测量的尺度依存性，直至进一步确定水力传导率与深度之间的关系。^-11  m / s，标准偏差为0.4个数量级，而米级原位测试的几何平均值为4.9×10 ^-9  m / s，标准深度为小于1.0数量级时的标准偏差为1.0个数量级。 深度大于23 m时为10 m和3.7×10 ^-11 m / s，且为0.2数量级。结果支持存在较高的水力传导率的浅裂缝区域和以基质渗透性为特征的较深区域。观测到的数据变异性主要发生在站点规模上，而数据的集中趋势和变异性在相距数百公里的站点之间是一致的，这表明从统计角度得出的，深度定义的区域水力传导率估算值可能是有意义的。