[5pt] Unrealistically High Slope Values from TAUDEM #1684
Description
Description
The SLOPE values generated by TAUDEM appear to include unusually large values.
A specific case was found for HUC 12030101, branch 0, where the SLOPE value was 677.13 (as shown in the screenshot below from src_base_0.csv):
This large value was subsequently propagated and used as the selected SLOPE in the src_full table for HydroID = 24371364.
Notes
- TAUDEM reports slope as Rise/ Run (tan θ) — a dimensionless ratio, not percent or degrees.
- Therefore, slope values can exceed 1.0, corresponding to terrain steeper than 45°.
- However, extremely high values (such as ≫ 10) often indicate artifacts caused by DEM irregularities, pits, or,...
- The value of 677.13 is therefore physically unrealistic and likely an error.
Proposed Action
Add a filtering step to handle abnormally high SLOPE values before they are used in downstream tables.