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I'm working on channel network extraction from a LiDAR DEM (square grid max resolution 0,25 cm), and my area of study is vary flat with some part below the sea level.

I applied the classical valley recognition method with D8 and ArcGIS software but the output, I think, is not correct (the fill tool modifies a lot the DEM).

I saw there are various method like, for example, Pelletier (2013) and Clubb et al. (2014) but they seem to be created for mountain areas and I can't find many methods applicable in flat areas.

What procedure can I use?

  • Not that it answers your question but QGIS offers a number of different flow accumulation algorithms. Maybe something other than the D8 will produce better results. translate.google.com/… – GBG Feb 15 at 18:27
  • In addition to considering the flow algorithm, I'd suggest using a different DEM preproccessing tool that may be better served for flat areas. Something like Fill Sinks Plus, discussed here: community.esri.com/thread/66980. Or WhiteBox GAT's DepressionBreach tool. – jbrengel Feb 15 at 20:03
  • Also, I've not seen this done on flat areas, but instead of using a flow direction based channel mapping procedure to derive stream channel, perhaps try a pattern recognition technique like geomorphons: sil.uc.edu/geom/app? Again, unsure if this would be appropriately applied in flat areas, since not sure if possible to distinguish channel patterns in a completely flat area. From my experience, it is not a simple thing to map accurate channels on flat areas. – jbrengel Feb 15 at 20:11
  • Thank you for the answers. I'm trying with Whitebox GAT DepressionBreach tool and D-infinity but I'm not very confidenti also in this solution. Probably I will turn my approach in something more geomorphic-based but It's a brand new world for me – Franco Perversi Feb 17 at 17:03

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