i.evapo.mh: fix radiation conversion factor#5600
Merged
petrasovaa merged 1 commit intoOSGeo:mainfrom Apr 29, 2025
Merged
Conversation
Contributor
|
The initial value of
that is in watts, but according to DROOGERS & ALLEN 2002:36 it should be given in megajoule (MJ m−2 d−1). So this PR should be good as far as I see it. cc @YannChemin |
Contributor
|
Possibly candidate for backport? |
neteler
added
the
backport to 8.4
petrasovaa
approved these changes
Apr 29, 2025
neteler
pushed a commit
that referenced
this pull request
Oct 6, 2025
Previously, the radiation input (ra) was multiplied by 86.4, incorrectly boosting the energy input and resulting in overestimated evapotranspiration values. This PR corrects the unit conversion: Changes ra = ra * (24.0 * 60.0 * 60.0 / 1000.0); to ra = ra * (24.0 * 60.0 * 60.0 / 1000000.0); This matches the correct SI conversion where 1 W/m² = 0.0864 MJ/m²/day
neteler
removed
the
backport to 8.4
Member
Done. |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
5 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This PR fixes an incorrect radiation conversion applied in the evapotranspiration calculations of the
i.evapo.mhmodule.Previously, the radiation input (
ra) was multiplied by86.4, incorrectly boosting the energy input and resulting in overestimated evapotranspiration values.This PR corrects the unit conversion:
ra = ra * (24.0 * 60.0 * 60.0 / 1000.0);tora = ra * (24.0 * 60.0 * 60.0 / 1000000.0);The correction is applied consistently across the following functions:
mh_eto()mh_original()mh_samani()Fixes #5520