Compiling and mapping global permeability of the unconsolidated and consolidated Earth: GLobal HYdrogeology MaPS 2.0 (GLHYMPS 2.0). [Supporting Data]

The spatial distribution of subsurface parameters such as permeability are increasingly relevant for regional to global climate, land surface, and hydrologic models that are integrating groundwater dynamics and interactions. Despite the large fraction of unconsolidated sediments on Earth’s surface with a wide range of permeability values, current global, high-resolution permeability maps distinguish solely fine-grained and coarse-grained unconsolidated sediments. Representative permeability values are derived for a wide variety of unconsolidated sediments and applied to a new global map of unconsolidated sediments to produce the first geologically constrained, two-layer global map of shallower and deeper permeability. The new mean logarithmic permeability of the Earth’s surface is 12.7 ± 1.7m2 being 1 order of magnitude higher than that derived from previous maps, which is consistent with the dominance of the coarser sediments. The new data set will benefit a variety of scientific applications including the next generation of climate, land surface, and hydrology models at regional to global scales.

诸如渗透率（permeability）这类地下参数的空间分布，在整合了地下水动力学与交互过程的区域至全球尺度气候、地表及水文模型中的重要性与日俱增。尽管地球地表广泛分布着渗透率跨度极大的未固结沉积物（unconsolidated sediments），但当前的全球高分辨率渗透率图仅区分了细粒与粗粒两类未固结沉积物。研究针对多样的未固结沉积物推导了代表性渗透率数值，并将其应用于全新的全球未固结沉积物分布图，由此生成了首张受地质条件约束的、区分浅层与深层渗透率的双层全球渗透率分布图。地球地表的平均对数渗透率新值为12.7±1.7平方米，较此前基于现有渗透率图得到的结果高出一个数量级，这与粗粒沉积物占主导的地质认知相契合。本全新数据集将服务于多类科学应用场景，包括面向区域至全球尺度的新一代气候、地表及水文模型。