• Re: User specified boundary - Not well defined


    Thanks for those hints Mathieu; this helped me understand better how Mike identify internal and open boundaries.


  • User specified boundary - Not well defined

    Hello everybody.

    I would like to manually define open boundaries in my M21 model. Basically, those boundaries are single points boundaries.
    Each time I try a simulation I get the following message : 'Single point boundary not well defined' or 'Internal boundary not well  defined'.

    I have absolutely no idea were is the problem from; could someone give me some hints to solve this issue ?

    Might this be linked to the land value ? Or the fact that one on my boundary is in the middle of my DEM (ie. On the coast; beyond the coastal boundary are blank values; deleted on the dfs2 file) ?


  • Unexplained flooding

    Hi everyone;

    I am facing a strange issue with mike 11 HD mapping.
    During the simulation, water level never go beyond river banks level in the whole system of my 1D/2D model however, when I look on the resulting flooding map, the whole are is flooded.

    How that could be possible?

    I thought about a Geoid issue with the SRTM and my bank points but since water do not go beyond banks; how does the plain could be flooded? Projection?

  • Error building search tree


    I have a problem running my Mike 21 FM model.

    I created a mesh with numerous quadrangular domains and get the following message when trying to run the model:
    Fatal Error: InsertElementd2DSearchTree: Error building search tree – Possibly erroneous mesh – Abnormal completion.

    Where could the problem be from? From the mesh itself I suppose but I don’t know which conditions the mesh needs to fill for the model to run without mesh geometry linked errors…

    I actually have some land boundaries within my network; might this be the reason? I didn’t find any solution to erase them from the mesh generator.

    Thanks by advance for hints you might give me.

    Best regards

  • Re: Quadrangular mesh generation

    Hi Mathieu;

    Thanks again =)
    Splitting meanders into smaller polygons was indeed the best solution.
    Actually I am using the 2008 version so, once again, you are right !
    Wish you the best.

  • Re: Quadrangular mesh generation

    Thanks Mathieu =)

    Okey; this worked indeed great but I suppose there is other constrains for the quadrangular mesh generation.

    Actually, the “ValidatePolygon() return FALSE” error message appear to be frequent even if the symmetry is respected regarding to the amount of points. Indeed, I managed to draw large polygons as a first test (high distance between river banks and sides of the polygon) but when I try to refine polygons (by adding points and reduce the distance between banks and polygons sides) for quadrangular mesh, the message appear and mesh generation is not anymore possible. I don’t have any idea where the message is from; any links with meanders (which are numerous) ?

    The “Transfinite interpolation" option seems to not be accessible in my version (not possible to select it…).

    Thanks again. Best

  • Quadrangular mesh generation

    Hello everybody;

    I have an issue trying to work on a Mike Zero mesh generation file.

    I work on a large floodplain and would like to get better mesh resolution along river branch and lower resolution on floodplain. This is to find the best compromise between computing time and results quality.

    I managed to apply quadrangular mesh on a test file and have been convinced by the method. Unfortunately, I would like to apply it to the entire area and get some problems to do so.

    The river system is quite complex. Attach is a schema of the network and loops (not all clockwise direction …) I try to digitalize with land/water boundaries to separate quadrangular from triangular mesh and open boundaries for upstream/downstream conditions. There is a total of 6 portions to be mesh with quadrangular cells.

    When polygon is selected; Start and End arcs defined; I basically get this message: “The polygon subdivision fail due to the unequal points on both side”; then “ValidatePolygon() return FALSE”

    Does somebody could help me to solve my problem and to remesh the DEM? Any other advice for quadrangular mesh generation?


  • Model lakes effects in large natural floodplain

    Hi everybody

    I would like to model the effect of lake within a large natural  floodplain (1000 km2) with multiple inflow/outflows.

    I would ask for orientation on options I have since I am novice in flood modeling and that I do not really know which function I better have to use: Regulating or user defined structure.

    Basically, maps are expected as outputs. How to be sure extends of the reservoir would be well represented? By digging the DEM (30m) or creating new branches with large interpolated CXs ?

    Thanks a lot

  • Re: Boundaries not considered in the simulation


    Thanks for this answer. Problem solved !

  • Boundaries not considered in the simulation

    Hello everyone;

    I have an issue related to boundary I Mike 21
    • Upstream boundary is file type 0 : Inflow
    • Downstream boundary is file type 0 : water level (tide)

    Model area is around 1000 km2. The model (inland) is surrounded by land value
    Boundaries are represented by one point each within the land value belt. They are automatically detected by the software.
    The river network is clearly defined (dug) within the bathymetry.

    Problem is that boundaries does not have effect and are not considered within the (incomplete) result file (only the initial surface elevation does).

    I tried different FAB type; no differences.

    Does somebody have an idea of the origin of my problem?
    Thanks by advance.