# iMOD User Manual version 5.2 (html)

#### 13.3Output

This chapter describes the output files that are, by default or optionally, produced by iMOD-WQ. The output files can be divided into 6 categories:

• 1. Standard output

• 2. Grid output (.IDF)

• 3. Point output (.IPF)

• 4. Tecplot output (.TEC)

• 5. Summary output (.FLX)

• 6. Standard Seawat input files

These 6 categories are described in the subsequent section.

##### 13.3.1Standard output

The set of standard output files that iMOD-WQ produces consists of the following files:

• 1. The List (.lst) File: this is the standard output file, which is generated every time the model is run.

• 2. The Unformatted Concentration File (.UCN), one for each species. This file contains concentrations saved at user-selected times in unformatted form.

• 3. The Mass Budget Summary File, one for each species. This file contains a one-line summary of mass budgets at every transport step or a user-specified interval.

Other standard output files produced by Seawat, MT3DMS and RT3D are the unformatted heads output file (.HDS), the Observation File (.OBS) and the Model Grid Configuration File (MT3D.CNF). In iMOD-WQ, the unformatted heads output file is not produced anymore as it is replaced by grid output (see section 3.2). The Observation File is replaced by IPF-files (see Section 3.3). The writing of the MT3D.CNF file is suppressed in iMOD-WQ as it is considered obsolete in the iMOD environment.

##### 13.3.2Grid output

Fluxes, heads and concentrations can be saved in iMOD grid format (.IDF) per model layer. iMOD-WQ produces subfolders for the different output types within the output folder specified in the runfile (keyword RESULT_DIR). Table 13.2 presents an overview of the different subfolders.

Timing/frequency of the grid output is controlled by keywords in the OC package. The table below explains the relevant keywords. The keywords offer the possibility to select stress periods and layers for which output is created. Be aware that output files for budget terms are only written if their corresponding flags are switched on in the respective packages (see also the column named "Produced when" in Table 13.2).

##### 13.3.3Point output

The Observation File type (.OBS) as present in MT3MDS and RT3D is replaced in iMOD-WQ by the iMOD Point File type (.IPF). The output .IPF file is placed in the conc results folder. It comes in the form of an IPF file (max. one per layer) with associated .txt files (one per observation location in the layer) with the time-variant information on concentration at that observation point. The associated .txt files are also places in the conc results folder. The resulting time-series can be visualized in the iMOD GUI (see Figure 13.26). Observation types other than concentrations are not (yet) available.

##### 13.3.4Tecplot output

Tecplot (www.tecplot.com) is a popular 3D visualisation and analysis tool. iMOD-WQ supports writing model output in the format required by Tecplot. Writing heads, concentrations and velocities in the three principal directions is facilitated. Currently, Tecplot output is only available if RUNMODE = SEAWAT. The Tecplot output is managed in the OC package. The table below explains the relevant keywords.

Example:

##### 13.3.5Summary output

iMOD-WQ produces .FLX output files, one per species, which gives for each transport time both the total (water) flux ($L^3/T$) and the total load ($M/T$) to each type of boundary condition (currently implemented are CHD, WEL, DRN, RIV and GHB). This is particularly useful when RUNTYPE = MT3DMS, as in that case water fluxes are not readily available in other MT3DMS output files. The information is written separately for incoming and outgoing fluxes. The naming of these output files is as follows: MT3D.FLX, and cannot be chosen differently. An example of the contents of such a .FLX file is given below.

##### 13.3.6Standard Seawat input

The runfile translator of iMOD-WQ creates input files for Seawat and MT3DMS that contain iMOD-specific formatting for efficient input handling. This makes that these files cannot be read by standard executables of Seawat and MT3DMS. For checking purposes, however, iMOD-WQ can on demand also produce standard Seawat input files in the formats accepted by Seawat v4. Currently, this functionality has only been implemented for the drn, riv, and .ghb file. The files are filled per stress period during runtime and are located in the subdirectory seawat_ori in the imod-wq_tmp directory.