Bug report #16982
TauDEM Stream and watershed delineation
|Affected QGIS version:||2.18.9||Regression?:||No|
|Operating System:||Easy fix?:||Yes|
|Pull Request or Patch supplied:||Yes||Resolution:||fixed/implemented|
|Crashes QGIS or corrupts data:||No||Copied to github as #:||24881|
There is an issue with how QGIS calls the TauDEM executable "StreamNet" from the command line. The "delineate single watershed" option has the reverse effect: leaving the box unchecked results in a single watershed, whilst checking the box leads to multiple subwatersheds being delineated.
The issue is due to the "-sw" flag (single watershed option): in the description, the boolean parameter value for the "-sw" parameter is set by default to "False" and in the python script "../python/plugins/processing/algs/taudem/TauDEMAlgorithm.py" line 114-116
elif isinstance(param, ParameterBoolean):
if not param.value:
a None value results in the parameter name, in this case "-sw" being appended to the command line. A simple fix is to edit line 115 to (see attached file)
" if param.value:"
which ensures that the flag is only added when a user checks the option, giving the parameter a value of 1, as expected.