Settings objects
Objects in this category contain the settings that govern several aspects of the model and the simulation template. Tags are also included in this category.
Model settings
Defines the settings that are needed in the creation of a 3Di model (computational grid and subgrid tables).
Raster files need to be stored in a folder called rasters, in the same folder as the schematisation geopackage.
This table can contain only one row.
Layer name
model_settings
Attributes
Attribute alias |
Field name |
Type |
Mandatory |
Units |
Description |
|---|---|---|---|---|---|
ID |
id |
integer |
Yes |
- |
Unique identifier |
DEM file |
dem_file |
Text |
No |
m MSL |
Name of the DEM file (*.tif) |
Minimum cell size |
minimum_cell_size |
Integer |
Yes |
m |
The width/length of the smallest possible 2D computation cell. See Computational grid for more details. |
Number of grid levels |
nr_grid_levels |
Integer |
Yes |
- |
The maximum number of 2D cell sizes, doubling in size each time. See Computational grid for more details. |
Calculation point distance 1D |
calculation_point_distance_1d |
Decimal number |
Yes |
- |
Maximum distance between calculation points for line elements. This global value is superseded in case it is specified for the specific 1D object. |
Minimum table step size |
minimum_table_step_size |
Decimal number |
Yes |
m |
Defines the height interval between successive increments in the subgrid tabulation. See Subgrid tables for more details. |
Maximum table step size |
maximum_table_step_size |
Decimal number |
No |
m |
Defines the maximum height interval between successive increments in the subgrid tabulation. Defaults to 100 × Minimum table step size. See Subgrid tables for more details. |
Table step size 1D |
table_step_size_1d |
Decimal number |
No |
m |
User-defined table step size/increment (m) for 1D cross-sections and volumes; see Subgrid tables. Defaults to Minimum table step size. |
Friction type |
friction_type |
Integer |
Yes |
- |
Defines the friction type for the 2D domain: 1: Chézy or 2: Manning. Make sure the friction type matches the friction coefficient (file). |
Friction coefficient |
friction_coefficient |
Decimal number |
Yes |
m1/2/s (Chézy) or s/m1/3 (Manning) |
Defines a friction coefficient for your schematisation. This global value is superseded in case a friction coefficient file is provided. |
Friction averaging |
friction_averaging |
Boolean |
Yes |
- |
Sets whether the friction values in a subgrid cell are averaged or not |
Friction coefficient file |
friction_coefficient_file |
Text |
No |
m1/2/s (Chézy) or s/m1/3 (Manning) |
Name of the friction coeffient file. This supersedes the global 2D friction coefficient. |
Use 1D flow |
use_1d_flow |
Boolean |
No |
- |
If false, no 1D network and 1D2D flowlines will be created when making the computational grid. |
Use 2D flow |
use_2d_flow |
Boolean |
No |
- |
If false, no 2D flowlines will be created when making the computational grid. Note that 2D cells (for storage) and 1D2D connections will still be made and used. |
Use 2D rain |
use_2d_rain |
Boolean |
No |
- |
Sets whether rain on the 2D domain is taken into account in a simulation. |
Use interception |
use_interception |
Boolean |
No |
- |
Sets the inclusion of interception in the 3Di model. |
Use interflow |
use_interflow |
Boolean |
No |
- |
Sets the inclusion of interflow in the 3Di model. |
Use simple infiltration |
use_simple_infiltration |
Boolean |
No |
- |
Sets the inclusion of simple infiltration in the 3Di model. |
Use vegetation drag 2D |
use_vegetation_drag_2d |
Boolean |
No |
- |
Sets the inclusion of 2D vegetation drag in the 3Di model. |
Use groundwater storage |
use_groundwater_storage |
Boolean |
No |
- |
If true, groundwater cells will be created. Switch on Use groundwater flow to also create groundwater flowlines. |
Use groundwater flow |
use_groundwater_flow |
Boolean |
No |
- |
If true, groundwater flowlines will be created. Switching on Use groundwater storage is required to use this option. |
Max. angle 1D advection |
max_angle_1d_advection |
Decimal number |
No |
Radians |
Maximum angle at which advection is taken into account (should be between 0 and 0.5 π). |
Manhole aboveground storage area |
manhole_aboveground_storage_area |
Decimal number |
For models with only 1D flow |
m2 |
Storage area for connection nodes at street level. This global value is the surface area that each connection node is given when water reaches above the exchange level. To use this feature, set the connection node exchange types to Connected. Must be left empty when using only 2D flow. |
Embedded cutoff threshold |
embedded_cutoff_threshold |
Decimal number |
No |
- |
When an embedded channel intersects a 2D cell with a length shorter than the cell size × cutoff threshold, the embedded channel skips this 2D cell. This is useful for preventing very short embedded channel segments (which slow down your simulation). |
Node open water detection |
node_open_water_detection |
Decimal number |
No |
- |
Sets which calculation nodes are labelled as open water vs. closed. Choose between 0: Node is regarded as open water if at least one channel connects to it (recommended) or 1: Node is regarded as open water if it has no storage area (not recommended; for backward compatibility only) |
Aggregation settings
You can set multiple aggregation options for each flow_variable as long as the aggregation_method is not used twice for the same flow_variable. For more information about result aggregation, see Aggregated output.
These settings are stored in the simulation template. You can change them before starting the simulation, without the need to regenerate the 3Di model.
Layer name
aggregation_settings
Attributes
Attribute |
Field name |
Type |
Mandatory |
Units |
Description |
|---|---|---|---|---|---|
ID |
id |
Integer |
Yes |
- |
Unique identifier. |
Flow variable |
flow_variable |
Text |
Yes |
- |
Variable that is to be aggregated. Text to fill in vs. how it is displayed in the 3Di Modeller Interface:
|
Aggregation method |
aggregation_method |
Text |
Yes |
- |
The aggregation methods that can be used on a flow variable. Text to fill in vs. how it is displayed in the 3Di Modeller Interface:
|
Interval |
interval |
Integer |
Yes |
s |
Interval over which the aggregation will be calculated |
Numerical settings
Most users do not need to worry about these settings. More advanced users can change the default settings to improve their models. For more information on the numerical settings, see Numerical settings.
These settings are stored in the simulation template. You can change them before starting the simulation, without the need to regenerate the 3Di model.
Layer name
numerical_settings
Attributes
Attribute alias |
Field name |
Type |
Mandatory |
Units |
Description |
|---|---|---|---|---|---|
ID |
id |
integer |
Yes |
- |
Unique identifier |
General numerical threshold |
general_numerical_threshold |
Decimal number |
No |
- |
Generally used numerical threshold to avoid singularities due to limited numerical accuracy. |
Max. non-linear Newton iterations |
max_non_linear_newton_iterations |
Integer |
Yes |
- |
Maximum number of non-linear Newton iterations in a single time step. For more information, see Settings for matrix solvers. |
Minimum convergence criterion for Newton’s method |
convergence_eps |
Decimal number |
Yes |
- |
Minimal residual for convergence of Newton iteration. For more information, see Settings for matrix solvers. |
Use nested Newton |
use_nested_newton |
Integer |
Yes |
- |
Choose between 0: For schematisations without closed cross-sections and 1: For schematisations with closed cross-sections. For more information, see Settings for matrix solvers. |
Number of conjugate gradient method iterations |
use_of_cg |
Integer |
Yes |
- |
Number of iterations of the conjugate gradient method before switching to another method. For more information, see Settings for matrix solvers. |
Convergence criterion for conjugate gradient method |
convergence_cg |
Decimal number |
No |
- |
Convergence criterion to iteratively solve matrices. For more information, see Settings for matrix solvers. |
Use preconditioner conjugate gradient |
use_preconditioner_cg |
Boolean |
No |
- |
Preconditioner for the matrix solver. Setting this to True generally increases simulation speed. For more information, see Settings for matrix solvers. |
Max. degree Gauss-Seidel |
max_degree_gauss_seidel |
Integer |
Yes |
- |
Determines the efficiency of the matrix solver. Advised values depend on the type of model:
Play around with this value in case of groundwater. This could potentially speed up your simulation significantly. |
CFL strictness factor 1D |
cfl_strictness_factor_1d |
Decimal number |
No |
- |
Strictness of the Courant-Friedrichs-Lewy ratio for 1D flow. |
CFL strictness factor 2D |
cfl_strictness_factor_2d |
Decimal number |
No |
- |
Strictness of the Courant-Friedrichs-Lewy ratio for 2D flow. |
Time integration method |
time_integration_method |
Integer |
Yes |
- |
The only option at the moment is 0 (Euler implicit). For more information, see Settings for matrix solvers. |
Flooding threshold |
flooding_threshold |
decimal number |
Yes |
- |
The water depth threshold for flow between 2D cells. The depth is relative to the lowest DEM pixel at the edge between two 2D cells. It should be equal or higher than 0. It is recommended to keep this value very low (1e-06). |
Flow direction threshold |
flow_direction_threshold |
Decimal number |
No |
m/s |
Threshold to determine the flow direction, in order to avoid flows of exactly 0.0 m/s. |
Minimum surface area |
min_surface_area |
Decimal number |
No |
m2 |
Numerical setting to guarantee proper matrix characterics |
Minimum friction velocity |
min_friction_velocity |
Decimal number |
No |
m/s |
Minimum velocity that is used for the transition of a cell from dry to wet. This is done for model stability. |
Friction shallow water depth correction |
friction_shallow_water_depth_correction |
Integer |
No |
- |
Determines how the friction is calculated. Choose between 0, 1, 2, and 3. For more information, see Numerical settings for friction. |
Limiter slope cross-sectional area 2D |
limiter_slope_crosssectional_area_2d |
Integer |
No |
- |
Limiter on the 2D slope cross-sectional area to allow the model to deal with unrealistically large cross-sectional areas resulting from the subgrid method in sloping terrain. Choose between 0, 1, 2, and 3. A limiter of 3 has to be used in combination with this water layer definition. For more information, see Limiters. |
Limiter slope friction 2D |
limiter_slope_friction_2d |
Integer |
No |
- |
Limiter on the 2D slope friction depth to allow the model to deal with unrealistically small friction values resulting from the subgrid method in sloping terrain. For more information, see Limiters. |
Limiter slope thin water layer |
limiter_slope_thin_water_layer |
Decimal number |
No |
m/s |
Has to be used in combination with setting Limiter slope cross-sectional area 2D to 3. For more information, see Limiters. |
Limiter water level gradient 1D |
limiter_waterlevel_gradient_1d |
Integer |
No |
- |
Limiter on the 1D water level gradient to allow the model to deal with unrealistically steep gradients. For more information, see Limiters. |
Limiter water level gradient 2D |
limiter_waterlevel_gradient_2d |
Integer |
No |
- |
Limiter on the 2D water level gradient to allow the model to deal with unrealistically steep gradients. For more information, see Limiters. |
Preissmann slot |
preissmann_slot |
Decimal number |
No |
m2 |
Mimics the effect of pressurized flows by creating a narrow slot on top of a pipe. Note that this method is not required for 3Di, but it can be used to compare results with other hydrodynamic simulation software. |
Pump implicit ratio |
pump_implicit_ratio |
Decimal number |
No |
- |
Determines whether and how 3Di will adjust the pump capacity based on the (expected) available water. Should be between 0 and 1. |
Physical settings
Settings related to the physics involved in the simulation.
These settings are stored in the simulation template. You can change them before starting the simulation, without the need to regenerate the 3Di model.
Layer name
physical_settings
Attributes
Attribute alias |
Field name |
Type |
Mandatory |
Units |
Description |
|---|---|---|---|---|---|
ID |
id |
integer |
Yes |
- |
Unique identifier |
Use advection 1D |
use_advection_1d |
integer |
Yes |
- |
See Advection in 1D domain. Choose from:
|
Use advection 2D |
use_advection_2d |
integer |
Yes |
- |
0: Off; 1: On |
Simulation template settings
Settings to set simulation properties in the simulation template.
These settings are stored in the simulation template. You can change them before starting the simulation, without the need to regenerate the 3Di model.
Layer name
simulation_template_settings
Attributes
Attribute alias |
Field name |
Type |
Mandatory |
Units |
Description |
|---|---|---|---|---|---|
ID |
id |
integer |
Yes |
- |
Unique identifier |
Name |
name |
integer |
Yes |
- |
Name of the simulation and the simulation template |
Use 0D inflow |
use_0d_inflow |
boolean |
No |
- |
Set to True to use Surface inflow and Dry weather flow |
Use structure control |
use_structure_control |
boolean |
No |
- |
Set to True to use Structure control |
Time step settings
Settings to set simulation and output time steps.
These settings are stored in the simulation template. You can change them before starting the simulation, without the need to regenerate the 3Di model.
Layer name
time_step_settings
Attributes
Attribute alias |
Field name |
Type |
Mandatory |
Units |
Description |
|---|---|---|---|---|---|
ID |
id |
integer |
Yes |
- |
Unique identifier |
Time step |
time step |
integer |
Yes |
s |
The default time step used in the simulation. |
Min. time step |
min_time_step |
integer |
Yes |
s |
Minimum time step that is allowed in the simulation. |
Use time step stretch |
use_time_step_stretch |
boolean |
Yes |
s |
If set to True, 3Di will use a larger time step than the simulation time step when the simulation reaches a steady state. |
Max. time step |
min_time_step |
integer |
Yes |
s |
Maximum time step that is allowed in the simulation. Use in conjunction with Use time step stretch. |
Output time step |
output_time_step |
integer |
Yes |
s |
The output time step that is written in the output file (NetCDF). This must be a multiple of the simulation time step. |
Tag
Tag that can be assigned to other schematisation objects. Example usages are to track data sources, assumptions, and automated or manual edits.
Layer name
tag
Attributes
Attribute alias |
Field name |
Type |
Mandatory |
Units |
Description |
|---|---|---|---|---|---|
ID |
id |
integer |
Yes |
- |
Unique identifier |
Description |
description |
text |
Yes |
- |
Text of the tag |
Schema version
This table exists in the schematisation database, but is not added to the project when loading the schematisation.
Shows the database schema version. The database schema is the definition of all tables, columns, and data types. If changes to the database schema are made, tools in the 3Di Modeller Interface will ask you to migrate the schematisation database to the newer database schema version. This migration will add or delete the tables and columns that have been changed.
Note
Do not change the schema version manually! Use the processing algorithm Migrate schematisation database.
Layer name
schema_version
Schema version attributes
Attribute |
Field name |
Type |
Mandatory |
Units |
Description |
|---|---|---|---|---|---|
Version number |
version_num |
Text |
No |
- |
Number determining which schematistion version is used, left-padded with zeroes to four characters. |