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Introduction

This tool allows the user setting-up or refining in few clicks an existing model. In particular, the following operations can be performed within Delft Dashboard:

  • Create or refine a computational grid (“*. grd” file)
  • Extract and interpolate bathymetry data from open source on-line databases on the computational grid (“*.dep” file).
  • Extract and interpolate tidal boundary conditions from open source on-line databases on the computational grid, creating boundary conditions for the model (“*.bnd” file).

 

Delft Dashboard contains a number of Tabs, which can be used to specify additional information to the model. The model can then be used directly to carry out hydrodynamics, waves, morphodynamics or water quality computations.

Make rectangular grid

After the grid outline is defined within the interface of Delft Dashboard the user can click on ‘Create grid’. The following routines (ddb_ModelMakerToolbox_makeRectangularGrid) will then be called:

  1. Determine the origin (xori, yori), spatial resolution (dx, dy), orientation (rot) and maximum bed level required (zmax) from the specified values in Dashboard.
  2. Create a full grid between these points (+ some buffer of 5%) based on the bathymetry active in Dashboard (default this is GEBCO ’08).  This grid will already be defined in the active coordinate system the user specified.
  3. Grid a rectangular grid within the boundaries specified in Dashboard. The grid cells which are above a certain bed level (zmax) are deleted. A linear interpolation is carried between the full grid and the rectangular grid within the boundaries

 

Figure: The rectangular grid created for New Zealand. At areas above Zmax (m) no grid cells are defined as can be seen clearly at of this example.

Make bathymetry

The (rectangular) grid defined with ‘make grid’ also needs a bathymetry. The user can click on ‘Create bathymetry’. The following routines (ddb_ModelMakerToolbox_bathymetry) will then be called:

  1. Determine which datasets are used and within which limit (zmin and zmax). This feature is especially handy when a different data set is used for the sea part and the land part. An offset can be used in order to shift the bathmetry. Diffusion is used for defining depth values for missing data (NaNs).
    1. If in quick mode ‘make bathymetry’ is used the active bathymetry in Dashboard (default GEBCO ’08) is applied
    2. Other bathymetry sets can be important via the Toolbox ‘Bathmetry’. More about this toolbox can be found in @.
  2. The function will now loop over the different dataset
    1. The bathymetry is first loaded.
      1. This can be downloaded from the OpenDAP server
      2. Or from your local directory file if the data needed is used in a previous set-up.
    2. Bathymetries are applied in the order defined.
    3. Interpolation from the original grid to the model grid is carried out with a linear interpolation. Only values (that are not NaN) are taken into account
  3. If an internal diffusion is applied the remaining non existing bed levels are filled in based on the mean bed level and after that a smoothing function is applied
  4. If a model offset is applied the whole bathymetry is shifted. An offset of 1 meter means the bed level will be 1 meter lower than originally.
  5. The bathymetry created is directly visible in Delft Dashboard.

Figure: The bathymetry created for New Zealand. The colors in Delft Dashboard are updated based on the value defined to the specific grid cell

 

 

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