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! 


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: 

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





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


Message Boards

Where to find grid cell volumes and water balance

Moritz Lehmann, modified 4 Years ago.

Where to find grid cell volumes and water balance

Youngling Posts: 8 Join Date: 1/16/15 Recent Posts
I am running a z-layer model of a large lake and I need to adjust the outflows to match an observed water level. This seems a common task, but I can't think of an easy way to do this, so any suggestions would be very welcome.

One way I can think of is to calculate the excess volume on a daily basis, but I can't find out where cell volumes are stored or how I can calculate them. Any advice using Open Earth Matlab functions would be greatly appreciated.

Thank you, Moritz
Adri Mourits, modified 4 Years ago.

RE: Where to find grid cell volumes and water balance (Answer)

Yoda Posts: 1221 Join Date: 1/3/11 Recent Posts
Hi Moritz,

Is it an option to specify a water level boundary?

The cell volumes are only written to the WAQ-input-files. In case you want to get the cell volumes you have the following options:
1. Get them out of the WAQ-input-files somehow.
2. Change the code to add the volumes to the map-file.
3.Compute the volumes using the depths and waterlevels being written.