9.4 Initial Conditions
9.4.2 Description
Water column initial conditions are recommended for each simulated water quality constituent. The supported initial condition model implementations are the same as those presented in Sections 7.10.2 and 8.7.2, and are summarised in Table 7.21. Water quality specific initial condition commands are listed in Table 9.4. The following sections describe how these initial condition implementations are extended for water quality simulations.
| Model Implementation | Description |
|---|---|
| Spatially Constant | Sets initial conditions using spatially constant fields in 2D or as horizontal uniform profiles in 3D. |
| Spatially Varying | Sets initial constituent values using 2D or 3D cell based CSV inputs. |
| Restart File | Reads initial conditions from a previous simulation restart file. |
| Command | Description |
|---|---|
| Initial WQ Concentration | Optional - Sets a spatially constant concentration for each simulated water quality constituent. This value is also constant for all water depths. |
| Initial Scalar Profile | Optional - Used to assign spatially constant but depth varying 3D initial condition profiles. |
| Initial Condition 2D | Optional - Used to specify spatially varying depth averaged initial constituent fields. |
| Initial Condition 3D | Optional - Used to specify spatially varying 3D initial constituent fields. |
| Restart File | Optional - Used to initialise salinity, temperature, suspended sediment, tracer and wq constituent fields from a prior simulation. |
9.4.3 Spatially Constant
9.4.3.1 Two Dimensional
This method sets a single value across the entire model domain for each simulated water quality constituent.
The nature and order of constituents in this command depends on the selected water quality simulation class as configured in the water quality control file. These are described in the water quality module manual for DO, Inorganics and Organics simulation classes.
9.4.3.2 Three Dimensional
This method sets a single horizontally constant value for each vertical layer across the entire model domain for each simulated water quality constituent using the
To set salinity, temperature and six (for example) water quality initial conditions as a laterally uniform profile, the referenced csv file requires the following columns:
- DEPTH: Depth values (m) from the surface downwards (positive downward) for assigning concentrations
- SAL: Corresponding salinity (psu) values at each of the depths in the DEPTH column
- TEMP: Corresponding temperatures (C) at each of the depths in the DEPTH column
- WQ_1: Corresponding water quality constituent 1 concentrations at each of the depths in the DEPTH column
- WQ_2: Corresponding water quality constituent 2 concentrations at each of the depths in the DEPTH column
- WQ_3: Corresponding water quality constituent 3 concentrations at each of the depths in the DEPTH column
- WQ_4: Corresponding water quality constituent 4 concentrations at each of the depths in the DEPTH column
- WQ_5: Corresponding water quality constituent 5 concentrations at each of the depths in the DEPTH column
- WQ_6: Corresponding water quality constituent 6 concentrations at each of the depths in the DEPTH column
Example initial scalar profile CSV.
IC_Profile_011.csv
DEPTH, SAL, TEMP, TRACE_1, WQ_1, WQ_2, WQ_3, WQ_4, WQ_5, WQ_6
0.0, 35.0, 25.0, 12.0, 8.0, 23.0, 0.5, 3.0, 4.0, 1.0
5.0, 35.0, 18.0, 12.0, 4.0, 25.0, 0.5, 2.0, 5.0, 0.0
10.0, 35.0, 11.0, 20.0, 0.0, 50.0, 0.5, 1.0, 8.0, 0.0
WQ_1, WQ_2 etc. are key headers. The names of water quality constituents are not recognised and are instead automatically associated with ordered water quality constituents. The nature and order of these constituents depends on the selected water quality simulation class as configured in the water quality control file. These are described in the water quality module manual for DO, Inorganics and Organics simulation classes.
9.4.4 Spatially Varying
9.4.4.1 Two Dimensional
Initial conditions can be set as spatial varying (depth averaged) across the model domain for water quality constituent concentrations within a 2D model with the
This command was previously described in Section 5.15.4 and 8.7.4.
To set salinity, temperature and six (for example) water quality initial conditions as a laterally uniform profile, the referenced csv file requires the following columns:
- ID: 2D cell ID
- WL: Corresponding water level values at each of the 2D cells in the ID column
- U: Corresponding U velocity values at each of the 2D cells in the ID column
- V: Corresponding V velocity values at each of the 2D cells in the ID column
- SAL: Corresponding salinity (psu) values at each of the 2D cells in the ID column
- TEMP: Corresponding temperatures (C) at each of the 2D cells in the ID column
- WQ_1: Corresponding water quality constituent 1 concentrations at each of the 2D cells in the ID column
- WQ_2: Corresponding water quality constituent 2 concentrations at each of the 2D cells in the ID column
- WQ_3: Corresponding water quality constituent 3 concentrations at each of the 2D cells in the ID column
- WQ_4: Corresponding water quality constituent 4 concentrations at each of the 2D cells in the ID column
- WQ_5: Corresponding water quality constituent 5 concentrations at each of the 2D cells in the ID column
- WQ_6: Corresponding water quality constituent 6 concentrations at each of the 2D cells in the ID column
Not all 2D cell IDs need be included in the csv file, so if this command is issued after any of the three commands listed in Section 9.4.3 then this Initial Condition 2D will overwrite only those cells specified. This command can be issued in either 2D or 3D simulations.
Example initial condition 2D file.
IC_ML_2D_037.csv - This lake resides over six TUFLOW FV cells
ID, WL, U, V, SAL, TEMP, WQ_1, WQ_2, WQ_3, WQ_4, WQ_5, WQ_6
23, 1.1, 0.0, 0.0, 1.6, 20.0, 9.0, 10.0, 7.0, 1.0, 0.5, 1.0
28, 1.1, 0.0, 0.0, 2.3, 20.0, 9.0, 10.0, 7.0, 1.2, 0.6, 3.0
29, 1.1, 0.0, 0.0, 1.8, 20.0, 7.0, 11.0, 8.0, 1.0, 0.7, 1.0
42, 1.1, 0.0, 0.0, 1.2, 20.0, 0.0, 10.0, 7.0, 1.0, 0.5, 2.0
45, 1.1, 0.0, 0.0, 2.4, 25.0, 0.0, 10.0, 7.0, 1.1, 0.9, 0.1
46, 1.1, 0.0, 0.0, 2.3, 20.0, 0.0, 20.0, 7.0, 1.0, 0.5, 0.1
WQ_1, WQ_2 etc. are key headers. The names of water quality constituents are not recognised and are instead automatically associated with ordered water quality constituents. The nature and order of these constituents depends on the selected water quality simulation class as configured in the water quality control file. These are described in the water quality module manual for DO, Inorganics and Organics simulation classes.
9.4.4.2 Three Dimensional
Initial conditions can be set at every three dimensional cell across the model domain for water quality constituent concentrations within a 3D model (only) with the
This command was previously described in Sections 6.8.3 and 8.7.4. To set salinity, temperature, and six (for example) water quality concentration initial conditions, the referenced csv file requires a column for each as follows.
- SAL: Corresponding salinity (psu) values at each of the 2D cells in the ID column
- TEMP: Corresponding temperatures (C) at each of the 2D cells in the ID column
- WQ_1: Corresponding water quality constituent 1 concentrations at each of the 2D cells in the ID column
- WQ_2: Corresponding water quality constituent 2 concentrations at each of the 2D cells in the ID column
- WQ_3: Corresponding water quality constituent 3 concentrations at each of the 2D cells in the ID column
- WQ_4: Corresponding water quality constituent 4 concentrations at each of the 2D cells in the ID column
- WQ_5: Corresponding water quality constituent 5 concentrations at each of the 2D cells in the ID column
- WQ_6: Corresponding water quality constituent 6 concentrations at each of the 2D cells in the ID column
Not all 3D cell IDs need be included in the csv file, so if this command is issued after any of the three commands listed in Section 9.4.3 then this Initial Condition 3D will overwrite only those cells specified. This command can only be issued in 3D simulations.
IC_ML_3D_037.csv - This lake resides over 2 3D cells (2 2D cells x 3 layers deep)
ID, WL, U, V, SAL, TEMP, WQ_1, WQ_2, WQ_3, WQ_4, WQ_5, WQ_6
23, 1.1, 0.0, 0.0, 1.6, 20.0, 9.0, 10.0, 7.0, 1.0, 0.5, 1.0
24, 1.1, 0.0, 0.0, 2.3, 20.0, 9.0, 10.0, 7.0, 1.2, 0.6, 3.0
25, 1.1, 0.0, 0.0, 1.8, 20.0, 7.0, 11.0, 8.0, 1.0, 0.7, 1.0
26, 1.1, 0.0, 0.0, 1.2, 20.0, 0.0, 10.0, 7.0, 1.0, 0.5, 2.0
27, 1.1, 0.0, 0.0, 2.4, 25.0, 0.0, 10.0, 7.0, 1.1, 0.9, 0.1
28, 1.1, 0.0, 0.0, 2.3, 20.0, 0.0, 20.0, 7.0, 1.0, 0.5, 0.19.4.5 Restart File
Restart files can be used to provide initial conditions for water quality constituent concentrations in the same manner as described in Sections 5.15.5 and 8.7.5. The combination of water quality constituents (and other variables) must be the same in the restart file and restarted simulation. Water quality properties specified in the water quality control file may change between simulations.