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?