K-values (horizontal and vertical), storage coefficients in the horizontal model and the porosity for the calculation of the storage coefficient in the vertical and 3D model are data that must be defined for all elements. However, due to the computational cost it is not possible to optimize for each element or node its own parameter. Therefore, these data are zoned.

The following model data types are provided to zone these parameters:

Parameter Z-KW for zoning the K-values (KWER, KWEV).

Parameter Z-SP for zoning the storage coefficients (KSPE).

The zones are established in the model file. The zone numbers must be integers > 0. If some elements or nodes are not defined in any Z-KW and Z-SP zone, an additional zone with the zone number 0 is automatically generated during the model checking, in which all non-covered elements or nodes are listed.

Within a zone exist three possibilities:

If only a corresponding initial parameter is defined for only one element/node of the zone in the parameter file, all the elements/nodes of that zone obtain this constant parameter value. In this case it does not matter, for which element/node of the zone this parameter was defined.

Only one parameter is optimized in this zone.

If initial parameters are defined for several elements/nodes of a zone, values are interpolated for all elements/nodes of this zone from these parameters (the interpolation algorithm must be selected). Parameters of other zones are not taken into account in this interpolation.

There are several parameters optimized within this zone, namely the parameters applied for the interpolation.

If no initial parameter is defined for an element/node in a zone the corresponding data of the model file are used for the calculation.

Within this zone no parameters are optimized. The calculation uses the constant values for the K-values or the storage coefficients of the model file (attributes KWER, KWEV or KSPE).

Should therefore the values of the model file be constant for elements or nodes in a zone, initial parameters for this zone must not be entered in the parameter file.

If one or more initial parameters are defined for certain zones in the parameter file the data for the elements/nodes of the zones entered in the model file is of no significance, because during the optimization they are replaced by the calculated values.

If all the elements/nodes are zoned and initial parameters are defined for all zones the input of K-values and storage coefficients in the model file is not required anymore.

Zoning of leakage coefficients