6 The Model

The model shown in Figure 15 was assembled using Visual Modflow FLEX, with the grid populated using the porosity and hydraulic conductivity relationships from the previous section.

At this point, the model is ready to be used for dynamic simulations. However, this model is presented to illustrate principles of subsurface delineation from borehole data. It represents the site as a single layer, while groundwater models typically require multiple layers to represent groundwater systems with multiple aquifers, engineered features within a groundwater system, and/or complex geologic heterogeneity, especially when contaminant transport or remediation is simulated.

For a multi-layer model, stratigraphic horizons can be modeled using the same methods described in this book. Geostatistical methods may also be applied; for example, most groundwater modeling pre-processing software allow properties such as hydraulic conductivity to be interpolated between observed values using a geostatistical algorithm such as Kriging.