Hi All,
I ran the SWY model in a region in Tanzania and got mostly some positive values for QuickFlow (QF) but also some negative values (pixels in pink in the attached screenshots).
I’m not sure what is the source of the negative QF values. Could that be explained by some sort of issue with the inputs (maybe DEM or lulc)?
Best,
Guille.
Yes, I ran the 3.8.0.
Will try the newest version.
Thanks.
Excellent, let us know how the 3.9 model fairs!
Doug
Hi Doug, I did tried the 3.9 version but obtained the same results (some QF negative values). This is a work for IUCN and I could send the model inputs if further analysis are needed.
Guille.
Hi @Guille ,
Happy to take a look at your data and make sure there are no glaring bugs. Google drive links to data work pretty well, you can also email the link if you don’t want to share publicly. ddenu@stanford.edu
Also, we’ve had similar questions to this one before on the forums. This threads conversation might be helpful:
Doug
Thanks a lot, Doug. I’m sending you the data through mail (drive link).
Best,
Guille.
Thanks @Guille ,
I just requested access to the link and will take a look once I can download the data provided.
Cheers,
Doug
Hi @Guille,
Thanks for sharing your data. It looks like the negative values in QF.tif are occurring on the edge of the raster where the DEM is nodata. Here’s a screenshot of what I’m seeing, where red pixels are less than 0 (all -11 QF values in this case ).
I’ll look into why this might be happening. Likely a nodata masking bug or alignment issue. But I don’t think it has a huge effect on the outputs. It seems to be a boundary issue.
I’ll update here what turns up, but let us know if you have any other concerns with the outputs you’re seeing.
Cheers,
Doug
