Posted Tue, 13 Nov 2018 14:05:18 GMT by Sebastian Gürke M. Sc.
Hej,

I'm planning to model a river including its floodplain and I'm not quite sure, what the best way is to do so. The floodplain will be based on a digital elevation model and will be modeled as a flexible mesh; easy so far.
But how can I model the river based on river cross sections (point-shapefile) as an quadrangular mesh? Would you simply digitalize the left and right river bank (f. ex. based on aerial images as polyline; without Z-Information) and import them as arcs, connect the alternate ends by arcs as well, redistribute the vertices of the two river bank arcs, generate the mesh AND afterwards apply the Z-information based on the river cross sections by importing the points from the point-shapefile as .xyz-file?

Coming from other software I'm used to a different approach: Import the cross section points (with Z-Information) and connect the single points by arcs and afterwards generate the mesh to ensure that each measured cross section point is part of the generated mesh.

Feedback & ideas are much appreciated, cheers.

Sebastian
Posted Mon, 17 Dec 2018 09:36:26 GMT by Christian Tomsu Germany
Hi Sebastian,

would be interesting, if you got any solution for that.

As I know, there is unfortunately no tool inside MIKE. You have to dodge to other softwares.
We for ourselfs have solved the mentioned problem with a GIS - Tool inside our toolbox.

Bests
Christian
Posted Mon, 17 Dec 2018 13:58:58 GMT by Hasan Zaifoğlu
Hi,

I understand that you only have point data of your cross-sections not any data between successive cross sections right? not dense data or point cloud?

My suggestion is using of ArcGIS. Model your river there and then convert it to ASCII points which is XXX.xyz. Then import it to mesh generator tool in order to interpolate and create your floodplain.

Hasan
Posted Tue, 18 Dec 2018 13:52:12 GMT by Sebastian Gürke M. Sc.
Hi Christian & Hasan,

[quote]would be interesting, if you got any solution for that.
[/quote]

No yet. To be honest I didn't have the time to figure it out and hoped someone knew a solution, sorry. :D

[quote]We for ourselfs have solved the mentioned problem with a GIS - Tool inside our toolbox.[/quote]
Interesting, could you explain how you do that in GIS (I'm quite familiar with ArcGIS).
[quote]I understand that you only have point data of your cross-sections not any data between successive cross sections right? not dense data or point cloud?[/quote]
Thats absolutely right, thanks!

Do you have any hints how you would do that in GIS?

Creating the quadrangular-mesh (without Z-Information) in MIKE21 ain't perfect, but it works. I'm just afraid that the Z-Interpolation based on only those cross-section height points is going to create a weird z-interpolated-mesh between those single-cross-sections.

Thanks in advance!
Sebastian

Posted Thu, 17 Jan 2019 05:10:55 GMT by Sebastian Gürke M. Sc.
Any hints?  :)
Posted Wed, 18 Dec 2019 09:41:37 GMT by Matinaz
Thanks for the knowledge

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