Hydrogeological overview map of Lower Saxony 1: 500 000 — Permeability of near-surface rocks (WMS service)

The map shows the permeability of the near-surface rocks in a scale of 1:500 000. The rock units of the Geological Survey Map 1:500,000 (GUEK500) have been divided into three permeability groups, which were defined according to a rough assessment of the effective cavity proportions and using the information available from hydraulic investigations. This assessment is based on the classification of mountain permeability, as given by the Working Group Hydrogeology of the State Geological Services in its hydrogeological carting instructions (Grimmelmann et al. 1997). The gross allocation of the permeability coefficients is carried out as follows: — Low permeability corresponds to permeability coefficients of < 1-10-5 [m/s],— — Mean permeability corresponds to the range of permeability coefficients from 1-10-5 [m/s] to 1-10-4 [m/s], — High permeability corresponds to permeability coefficients of > 1-10-4 [m/s] and — Permeability highly variable means that the corresponding rock complex has such different properties that it can be clearly assigned to any group. The map presented here was created by reattributing the contents of the Geological Overview Map of Lower Saxony 1: 500 000 and thus, as a rule, only takes into account a depth range of about 2 m below the top of the terrain.本地图以1:500 000的比例尺展示了近地表岩石的渗透性。1:500 000地质调查图（GUEK500）的岩石单元被划分为三类渗透性组别，划分依据为有效孔隙占比的粗略评估，以及水文勘察可得的相关信息。该分类基于德国国家地质调查局水文地质学工作组在其《水文地质制图规范》（Grimmelmann等，1997）中提出的山地渗透性分类方案。渗透系数的大致划分标准如下：— 低渗透性：渗透系数小于1×10^-5 m/s；— 中渗透性：渗透系数范围为1×10^-5 m/s至1×10^-4 m/s；— 高渗透性：渗透系数大于1×10^-4 m/s；— 渗透性高度多变：指对应的岩石复合体性质差异显著，无法被明确划归至上述任一组别。本次展示的地图通过对下萨克森州1:500 000地质概览图的内容进行重新归类编制而成，因此通常仅考虑地表以下约2米深度范围内的地层。