# iMOD User Manual version 5.2 (html)

#### 7.6GeoConnect Tool

WHY?
The GeoConnect Tool is an instrument that can be used to aggregate geological formations to model layers and vice versa.

WHAT?
With the GeoConnect Tool it is possible to aggregate geological formations to a dataset with different model layers containing combined formation information. It is now possible to go from model results with multiple geological formations per layer to a geological formations dataset. Besides, with this tool it is possible to use geological formations to come up with a new model parameterization. This functionality is also available as a batch-function (see section 8.8.8).

HOW?
Before starting the GeoConnect Tool, the user needs to create a textfile with the general settings to be used in the tool. This file needs to be placed in the "IMOD_USER\SETTINGS\" subfolder with the name "GeoConnect.txt".

The textfile with general settings needs to contain the following keywords:

These settings are automatically placed on the Settings tab on the GeoConnect window whenever the tool is started. The aggregation process is described in the example below.

Example 1
ACTLAYERS=1111110000000000000
REGISFOLDER=d:\Model_Ibrahym\REGIS\
TOPFOLDER=d:\Model_Ibrahym\TOP\VERSION_1\
BOTFOLDER=d:\Model_Ibrahym\BOT\VERSION_1\
NLAY=19

Geostratigraphy textfile
The geostratigraphy.txt file contains the order of the formations (from surface layer to base) and needs to be located in the Settings-folder in the iMOD user environment (in case of using the GUI), contains all formation abbrevations as used in the geological dataset and corresponding factors. This file can be loaded into the Postprocessing-tab on the GeoConnect window in the iMOD-GUI.

Example of the first 11 and last 4 lines of a geostratigraphy.txt:
HLC
BXSCK1
BXZ1
BXLMK1
BXK1
BXZ2
BXK2
BXZ3
BEROK1
BEZ1
BEK1

MTQ
GUQ
VAC
AKC

Calculation/Aggregation of formations:
This example shows the mathematical theory behind the aggregation of formation characteristics within one model layer. The formulas in the table are used to calculate the new transmissivity, groundwater head vertical resistance and flux. The choice of the formula depends on the variable that needs to be aggregated. In case, it is preferred to calculate the transmissivity (see figure) of the first and second model layer based on the formations given in the formation dataset, the first formula in the table is used to achieve this. In example: $T1=(d_{1}^{f}\times k_{1}^{h}\times f_{1})$
$T2=(d_{2}^{f}\times k_{2}^{h}\times f_{2})+(d_{3}^{f}\times k_{3}^{h}\times f_{3})+(d_{4}^{f}\times k_{4}^{h}\times f_{4})$

Start the Tool
To start the GeoConnect Tool select Toolbox from the main menu, choose GeoConnect Tool. This tool allows the user to continue working in the same iMOD session and using the GeoConnect tool at the same time. Included are a preprocessing, a postprocessing and an identify functionality. The tool opens with the Settings tab up front. The general settings on the tool-window are:

Example of the GeoConnect window; Settings tab

Identify
The Identify option can be found on the first tab of the GeoConnect window. With this option it is possible to analyze, "on-the-fly", the model composition per individual location by making use of the Identify button. The functionality shows the content of the geological formations in the model at mouse position. Aquitard layers (e.g. clayey formations) are identified as connected to the Aquifer layers (sandy formations), the clayey layers are so called "interbed" layers. When a model layer contains a clayey layer the fraction shown in the Identify table is always 100%. See for example Layer 2 in the figure below (Identify-tab). This layer consists for 0.211% of BXZ3, 26.538% of BEZ1, 73.140% of BEZ2 and for 100% of BEK2.

Example of the GeoConnect window; Identify tab

Preprocessing
The preprocessing functionality in the GeoConnect tool can be used to compute a renewed model parameterization out of the geological formation related top-, bot- and k-values.

Example of the GeoConnect window; preprocessing tab

Postprocessing
The postprocessing functionality in the GeoConnect tool can be used to perform model layer aggregation for variables to be chosen based on the formation settings.

Example of the GeoConnect window; postprocessing tab