Using the PLPROC parameter preprocessor supplied with the PEST suite, moveable polylinear and polygonal structural features such as faults and aquitard windows can be inserted into a model. These features can be assigned to one or many model layers. Hydraulic properties can vary along and within them.
If appropriate, the hydraulic properties associated with structural features can “blend” into those of their surroundings. Relationships between model outputs and structural feature shapes and locations therefore become continuous. This allows the latter to be configured as adjustable parameters as PEST or PEST++ undertakes model calibration or history-match-constrained uncertainty analysis.