How can I create dfs2 files as boundary conditions to MIKE 3 FM?

You can use a dfs2 file to describe a vertical boundary condition in MIKE 3 FM. 

When using a dfs2 file to describe the vertical variation of an item at the boundary, the x-axis defines the spatial extension in the horizontal plane and the y-axis is interpreted as the extension in the vertical given relative to a level defined by the y-axis origin.

The z-level for the rows in a dfs2 file is found by

    z(j) = origin(y) – dy*(NY – j)

where dy is the grid-spacing in y-axis direction, NY is the grid size -1 and Origin(y) is the level for the upper row (j=NY).


The origin for the spatial axis in the vertical is usually set to 0.0, i.e. lowest level corresponds to -dy*NY and the upper level correspond to MWL=0m.  


The mapping from the input dfs2 data file to the boundary section described by the mesh layers is defined by the interpolation type.


In case the boundary of the mesh domain contains levels below or above this interval the values will correspond to the nearest level. An example is given in Fig. 1.


Fig. 1 - Showing example of dfs2 boundary imposed on an equidistant sigma mesh. Values in levels below -2000m will correspond to value in level -2000m


You can use Grid Editor in MIKE Zero for creating a dfs2 file from scratch and/or modifying the axis settings or grid values in an existing dfs2 file.

  • For creating a dfs2 file based on a dfs0 file please see this link:  KA-01030  - DHI Customer Care Portal (
  • For creating a dfs2 file based on a dfs1 file you can download the source code for a small MIKE Core SDK script from the link at the bottom of the page.


Manuals and user Guides
MIKE 3 Flow Model FM User Guide
MIKE Core SDK User Documentation


Related Products: MIKE 21/3

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