intro story D-Flow FM

 

D-Flow Flexible Mesh

D-Flow Flexible Mesh (D-Flow FM) is the new software engine for hydrodynamical simulations on unstructured grids in 1D-2D-3D. Together with the familiar curvilinear meshes from Delft3D 4, the unstructured grid can consist of triangles, pentagons (etc.) and 1D channel networks, all in one single mesh. It combines proven technology from the hydrodynamic engines of Delft3D 4 and SOBEK 2 and adds flexible administration, resulting in:

  • Easier 1D-2D-3D model coupling, intuitive setup of boundary conditions and meteorological forcings (amongst others).
  • More flexible 2D gridding in delta regions, river junctions, harbours, intertidal flats and more.
  • High performance by smart use of multicore architectures, and grid computing clusters.
An overview of the current developments can be found here.
 
The D-Flow FM - team would be delighted if you would participate in discussions on the generation of meshes, the specification of boundary conditions, the running of computations, and all kinds of other relevant topics. Feel free to share your smart questions and/or brilliant solutions! 

 

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We have launched a new website (still under construction so expect continuous improvements) and a new forum dedicated to Delft3D Flexible Mesh.

Please follow this link to the new forum: 
/web/delft3dfm/forum

Post your questions, issues, suggestions, difficulties related to our Delft3D Flexible Mesh Suite on the new forum.

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** PLEASE TAG YOUR POST! **

 

 

Sub groups
D-Flow Flexible Mesh
DELWAQ
Cohesive sediments & muddy systems

 


Message Boards

Bathymetry Interpolation Problem

LC
Luca Castrucci, modified 4 Years ago.

Bathymetry Interpolation Problem

Youngling Posts: 14 Join Date: 6/17/16 Recent Posts
Hi all,

After having extracted the bathymetry from the raster using ArcGIS tool Spatial Analyst Tool - Extraction - Sample, I was able to import the data on Delft3D-Quickin. I decided to use Grid Cell Averaging as interpolation method, since I have more than one bathymetry data inside a grid cell. The problem is that some grid cells remain without value, even if they are in the middle of the ocean, thus they should have bathymetry data. When I click on these grids, Quickin gives me the values "nan". To find a solution, I have tried to use polygon and internal diffusion, but it does not work and the grids remain without values. I have also used Quickin tool Operations - Combine Depth and Uniform Value - Fill Missing Depth with Uniform Value, but I did not solve the problem as well. Is anyone had this problem? This problem is really frustrating since it does not let me load the bathymetry .dep file on Delft3D-FLOW.
Another question, are we allow to have grid points close in the shore that do not have bathymetry data? I found very hard to design a grid that fit perctly the bathymetry; thus some grids cells remain outside.

Thanks for your help guys!!!!
Richard Measures, modified 4 Years ago.

RE: Bathymetry Interpolation Problem

Jedi Knight Posts: 178 Join Date: 3/23/11 Recent Posts
Hi Luca,

Adjusting the settings for grid cell averaging might help you fill more points using grid cell averaging: In QUICKIN if you go to Settings - General you get a dialog box where you can adjust the "minimum number of averaging points" and the "relative search size for averaging". The default setting require a minimum number of 4 points per cell in order for grid cell averaging to work. Decreasing the minimum number of points and/or increasing the search radius may be useful to you?

I'm not sure why internal diffusion or triangular interpolation aren't working for you as they usually work well? Have you tried deleting all polygons (Operations - Delete - Polygons) and then drawing one simple polygon over the area you want to work on before applying the tool? These tools only fill in null depths, they don't overwrite depths already assigned (e.g. by grid cell averaging) so there is no need to be too precise with the polygon.

Good luck,
Richard
LC
Luca Castrucci, modified 4 Years ago.

RE: Bathymetry Interpolation Problem

Youngling Posts: 14 Join Date: 6/17/16 Recent Posts
Hi Richard,

Thanks for your reply. I followed your advises but unfortunately I was not able to find a solution for my problem using Delft3D GUI tools. Thus, I decided to write a Matlab script and I solved the issue.


Best

Luca