After flow accumulation analysis, what will be the criteria to define the threshold to extract the stream network from DEM? As stream threshold value will influence the extracted drainage networks and stream order level and thus the basin morphometric analysis.
I think it depends on your requirements. Each software comes with default parameters, but they can be adjusted to increase or decrease the number of streams. The topography is an important factor, flat areas do not require a dense drainage extraction.
You could try with GRASS GIS, see the documentation of r.stream.extract module.
Lizardo
There is no certain threshold for such task and it depends on your needs and the topography of your study area.
Hello Alemsha G. Bogale,
There is no specific global threshold to mask out the water bodies/stream network from DEM. Nevertheless, a threshold can be fixed for a region, but the same cannot be applied elsewhere. As the topography changes, the threshold changes, as its local elevation changes from the Mean Sea Level(MSL).
However, NASA provides a global water body mask generated using SRTM DEM data. Kindly check, It may be helpful for your research. It is available in https://lpdaac.usgs.gov/products/srtmswbdv003/
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