1

I am looking for guidance about reliable method of sub-basin length calculation.

I am a student and working on morphometric analysis for prioritization of sub-watersheds of a river basin. I am using White Box Tool Plugin for ArcGIS Pro for watershed delineation and stream network extraction.

I used this formula given by Schumm Lb=1.312*A^0.568 to calculate sub-basin length , length exceeded the actual length of basin. In literature this formula is mostly used in morphometric analysis. I am confused about measurement of length of sub-Basins in Morphometric parameters analysis. I want to know how to relate (how can I check / assess or verify) the length of sub-Basin obtained from this formula?

These are the some screen shorts about length calculation;

Basin Length Calculated by using Formula

Basin length I Calculated manually

Diagram of Basin length calculation

Basin Length Calculated in an article

Improve this question
1
  • 2
    To answer this question you need to do some research and report back the official definition of Basin Length. The straight line distance from the mouth is that to a point on the catchment boundary that is nearest to the longest flow or simply the longest straight line in the polygon but anchored to the pour point?
    – Hornbydd
    Jun 22, 2022 at 11:44

1 Answer 1

Reset to default
1

The formula you are quoting (Lb=1.312*A^0.568) is a regression line developed by researchers looking at many watershed areas and their stream lengths. As such, it's just a correlation, to describe "average" watersheds. Not a magic formula that would let you skip actually measuring your flowpaths.

If you have a specific watershed, the way to calculate it's length is to measure the length of the longest flowpath. In ArcGIS, have a look at "flow length" in the spatial analyst toolbox.

Improve this answer
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.