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I am working on sub-watersheds delineation of an area. The extracted streams do not match with the real world scenario. I have two issues;

  1. there are multiple streams lines which do not match with real water channels as their point of joining with river is different from actual joining point /spot
  2. the river meandering also does not match with the real world

As in the image below, it can be seen the multiple streams and their deviation of streams from actual river flow.

Data Sources: a) SRTM 1 arc DEM b) Sentinel-2 (April, 2022) image.

Method adopted: Standard Hydrology Toolset in ArcMap is used.

I am looking for help to solve these two abovementioned problems.

Data Used https://drive.google.com/drive/folders/1ErBJypaxrtjzspznhQYifjMWNoHXcASp?usp=sharing

Sentinel-2 imagery having Streams in red

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  • Unfortunately, this almost always happens when generating streams from a DEM. You may have shadows or other artefacts causing this behaviour, or it can be caused by the difference in the horizontal and vertical resolution of the DEM. . You can try burning in a stream network if you have one.
    – vinh
    Commented May 23, 2022 at 11:35
  • Thank you for your kind response.
    – AM38
    Commented May 23, 2022 at 14:27

1 Answer 1

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These well known artefacts caused by either low resolution of DEM (large flat areas) or depressions. In case of flat terrain, you can try Taudem package, it might improve results somehow. If issue about depressions, try Whitebox.

Depression check:

Con(Filled > DEM, Filled-DEM)

enter image description here

This image is output of standard Hydrology tools for terrain with depressions:

enter image description here

This is output from Taudem on the same terrain:

enter image description here

These are streams output from my own procedure:

enter image description here

which using least cost analysis for stream delineation inside depressions.

I have Powerpoint presentation of the process, but it is not free.

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  • Thank You. The study area is mountainous but there are still some plain areas in river flow path.
    – AM38
    Commented May 24, 2022 at 8:20
  • any tutorial, manual / guide for hydrological analysis for sub-watershed delineation can be very helpful for me. I have tried to get any of them but I could not. Especially, there is no workflow or user manual of WBT for hydrology. I am trying to extract the accurate streams network.
    – AM38
    Commented Jun 1, 2022 at 12:12
  • I have treid WBT on ALOS-PALSAR DEM12.5 in ArcPro. Now the issues I am facing are: 1. I have streams at those place where in real world there is no stream 2. the river flow path is still different from the real the real path. May I have any solution other than the paid presentation. I am a new learner of GIS and I am seeking help for my assignment.
    – AM38
    Commented Jun 1, 2022 at 12:56
  • Ok, upload test catchment, I'll check if my method will improve output
    – FelixIP
    Commented Jun 1, 2022 at 19:29
  • Please find SRTM and ALOS-PALSAR DEM (AOI) and Streams. drive.google.com/drive/folders/…
    – AM38
    Commented Jun 2, 2022 at 10:03

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