width and length ratio for tessalate_river_aligned in WW

[Yeonju Kim]

Dear all,

I am trying to generate tessellate_river-aligned meshes with wide channels (e.g., width = 8 m) and short segment lengths (e.g., limit=1 m) in order to implement in-stream obstacles.

I understand that the dilation_width argument in create_river_mesh (in river_mesh.py) controls the ratio between width and segment length.

I was able to reduce the segment length somewhat using densify_rivers_new(limit=4), but the resulting segments are still longer than needed for my application. Do you have any suggestions on how to further shorten the segments?

Below is the error I encountered when attempting to run the following:

watershed_workflow.densification.densify_rivers_new(rivers, limit=1)

widths =  dict({1:8, 2:8, 3:8, 4:8})

mesh_points2, conn_list, areas, dists = watershed_workflow.tessalate_river_aligned(watershed, rivers, river_width=widths, ...)

------------------------------------------------------------------------------------------------------------------------------------

File --- in create_river_corridor(river, width)

    368 # check if the points on the river corridor are same as calculated theoretically
    369 if not _isExpectedNumPoints(corr3, river, n):
--> 370     raise RuntimeError(
    371         f"Broken dilation -- expected {n} coords, got {len(corr3.exterior.coords[:])}"
    372         " -- recommend running with ax argument to tessalate_river_aligned() to debug!")
    374 return corr3

RuntimeError: Broken dilation -- expected 0 coords, got 2989 -- recommend running with ax argument to tessalate_river_aligned() to debug!

--------------------------------------------------------------------------------------------------------------------------------------------

Thanks in advance,

Yeonju

[Rathore, Saubhagya]

Hi Yeonju,

 

The existing workflow for stream-aligned mesh generation relies on the quads being elongated, i.e., length being few times the width. That said, there is a major Watershed Workflow refactor underway; the new version approaches river-corridor dilation differently, and (I think) will allow short quads (width comparable or greater than length) like you want. Keep an eye out for a new Watershed Workflow release later this week.

 

Meanwhile, you can consider manipulating Mannings coefficient in quads to mimic obstruction in the river corridor if you like. Not optimal, and I would use the upcoming Watershed Workflow version as it seems you want to keep obstruction localized.

 

Regards,

Saubhagya

 

From: ats-...@googlegroups.com <ats-...@googlegroups.com> on behalf of Yeonju Kim <iamkim...@gmail.com>
Date: Monday, July 28, 2025 at 3:47 PM
To: Amanzi-ATS Users <ats-...@googlegroups.com>
Subject: [EXTERNAL] width and length ratio for tessalate_river_aligned in WW

Dear all, I am trying to generate tessellate_river-aligned meshes with wide channels (e. g. , width = 8 m) and short segment lengths (e. g. , limit=1 m) in order to implement in-stream obstacles. I understand that the dilation_width argument in

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[Rathore, Saubhagya]

Hi Yeonju,

 

The new version hasn’t been released yet. Please wait for Ethan’s announcement, which will include details on the updates.

 

Regards,

Saubhagya

 

From: Yeonju Kim <iamkim...@gmail.com>
Date: Monday, August 4, 2025 at 11:33 AM
To: Rathore, Saubhagya <rath...@ornl.gov>
Cc: Amanzi-ATS Users <ats-...@googlegroups.com>
Subject: Re: [EXTERNAL] width and length ratio for tessalate_river_aligned in WW

Thank you so much, Dr. Saubhagya — your insight has opened up a new direction for me! I looked into the newer version of Watershed Workflow. Did you mean the commit titled "work on differential catchment/subcatchment splitting" on

Thank you so much, Dr. Saubhagya — your insight has opened up a new direction for me!

I looked into the newer version of Watershed Workflow. 

Did you mean the commit titled "work on differential catchment/subcatchment splitting" on the Watershed Workflow GitHub? I noticed that this commit doesn’t include any modifications to river_mesh.py.

May I ask which specific version or commit you were referring to?

Thanks again for your guidance!

Best regards,
Yeonju

 

[Yeonju Kim]

Thank you so much, Dr. Saubhagya — your insight has opened up a new direction for me!

I looked into the newer version of Watershed Workflow. 

Did you mean the commit titled "work on differential catchment/subcatchment splitting" on the Watershed Workflow GitHub? I noticed that this commit doesn’t include any modifications to river_mesh.py.

May I ask which specific version or commit you were referring to?

Thanks again for your guidance!

Best regards,
Yeonju

On Mon, Jul 28, 2025 at 4:01 PM Rathore, Saubhagya <rath...@ornl.gov> wrote: