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dtarb / TauDEM

Terrain Analysis Using Digital Elevation Models (TauDEM) software for hydrologic terrain analysis and channel network extraction.
http://hydrology.usu.edu/taudem
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Zero length river segments #266

Open mee067 opened 1 week ago

mee067 commented 1 week ago

Hi,

I delineated subbasins and rivers for a large basin (~ 900 k sqkm). I got more rivers segments than subbasins. Investigating the issue, there are zero length segments when 3 streams meet. It seems it can only allow 2 streams to join so it creates an intermediate one to resolve the issue but this stream has zero length and has no corresponding subbasin.

Is there a parameter to control the max number of streams that can meet at a point?

dtarb commented 1 week ago

The behaviour you are seeing is the way it was designed. The model for link (stream segment connectivity) has one downstream link and two upstream links. Where 3 or more streams join at one place, artificial links are included to maintain the connectivity within this framework. There is not a parameter to adjust for this. In the way you are using this, how is this a problem. It may be possible to work with the streams and subbasins delineated and identify and filter out zero length streams (stream length is a column in the table) and adjust connectivity to meet your needs. However, in the short term at least, this is something you would need to do.

mee067 commented 1 week ago

the problem is that the link does not have a basin - a tiny one, created with it. I am using the delineated basins and rivers to create a drainage database for a hydrological model and the remainder of the workflow could fail if it finds a river without a corresponding basin.