With Adaptive Groundwater, hydraulic conductivity (K) may be assigned either as homogeneous K zones or a correlated, lognormally-distributed random K [ln(K)] field by selecting the appropriate radio button in the Simulation Control Parameters dialog. Porous media zones can be assigned by window or polygon (User-defined or imported ASCII polyline coordinates), or on a cell-by-cell basis. In plan view all higher-level grid cells contained in a specific Base Grid cell are assigned the same property value. In cross-section you can optionally increase the grid resolution for material-zone specification (e.g., to add a thin regional clay layer or high-resolution bedrock surface) so that the material layers are much thinner than the base-grid layers (i.e., as thin as the layer thicknesses in the most highly-refined regions of the grid). Parameter values are assigned within the “Porous Media Properties Database” dialog.
Porous media zones may also be assigned based on interpolated geologic contact surfaces that separate delineated hydrogeologic units. With this option the existing porous media zones are permanently replaced by specific zones associated with each hydrogeologic unit. Surfaces defining geologic contacts are loaded through an ASCII file containing XYZ and header information.
The correlated random ln(K) distribution is characterized by a geometric mean, a ln(K) variance, and horizontal and vertical correlation lengths.
Random K values are generated on the highest level of AMR refinement and averaged (geometric mean) for coarser AMR level cells.