Appendix G — TESF Commands

The External Stress File (.tesf) allows the definition of time varying global or spatially varying external forcing such as wind or wave radiation stresses, it is read into the .tcf using the External Stress File command. For more information on the .tesf see Section 4.1.13. Applying external stresses is discussed in Section 8.7. The available TESF commands are listed below. For an explanation of the command syntax, see Commands.

G.1 TESF Commands

Global Wind BC == <boundary_name>

This command defines the Wind BC name in the BC Database (Section 8.5). It invokes a global wind boundary in a model. See Section 4.1.13.

Grid Interpolation Method == IWD | Poly | {no default}

Defines the external stress grid interpolation method. See Section 4.1.13.

IDW Exponent == {2.0} | <value>

Sets the exponent term to be used in the external stress IDW interpolation. See Section 4.1.13.

IDW Maximum Distance == <value>

This can be used to set the maximum distance for a point to be considered in the external stress IDW interpolation, any points further than this are not used in the IDW interpolation. If not specified no maximum distance is considered. See Section 4.1.13.

IDW Maximum Point == {all} | <maximum_points>

Controls the maximum number of points considered in the external stress IDW interpolation. By default, all point locations will be used. If a very large number of point locations are provided this command can be used to reduce the memory usage. For example, if 100 wind locations are provided, and the IDW Maximum Point is set to 20 at each output grid interpolation point only the closest 20 points are used. See Section 4.1.13.

Output Grid Cell Size == <value> | {10 x the smallest 2D cell size}

Sets the grid size for the generated stress grids. If omitted, a value of 10 times the smallest 2D cell size is used. Typically, wind stresses can be satisfactorily represented on a much coarser resolution than that required for the hydraulic computations, and using high resolution stress grids is typically not required and may unnecessarily increase memory usage, disk space and may slow down the simulation. See Section 4.1.13.

Output Grid Format == ASC | FLT | {NC}

Sets the output grid format to be used if interpolating point data to a stress grid. The default is to use NetCDF as this packages all output grid data for the simulation into a single .nc file. See Section 4.1.13.

Output Grid Origin == x, y

Sets the origin for the output stress grids. If this command is omitted, the model origin is used. See Section 4.1.13.

Read GIS Wind Point == <gis_file>

This command defines spatially varying wind BC name information, as referenced in the BC Database (see Section 8.5). This command invokes external stress grid interpolation. Uses 2d_ws GIS layers, as described in Table 8.15.

Read GIS Wind Poly == <gis_file>

This command defines spatially varying wind BC name information, as referenced in the BC Database (see Section 8.5). This command invokes external stress grid interpolation. See Section 4.1.13. Uses 2d_ws GIS layers, as described in Table 8.15.

Read Gridded Tau == <path_to_.nc_or_grid_index.csv>

This command is used to reference a user defined external stress file. See Section 4.1.13.