NDR:negative value of result

Hi, everyone,
I ran the model several times with NDR and tried different parameters, but the model runs came out with negative values, is this a normal situation?

Hi @yajiaoban -

It is not typical to get negative values in the NDR results. Which result(s) had negative values? One of the *_export.tif rasters? Or something in the aggregated watersheds output?

In general, if output values seem different than you’d expect, you can use the layers in the intermediate_outputs folder, along with the equations in the User Guide, to get an idea of which step produced the negative values.

~ Stacie


Hi, thanks for your reply ,It’s the *_export.tif rasters , In general , I think maybe there is no negative value, but everything is ok ,but there are still negative values come out , I don’t know if it is normal.

Stacie Wolny via Natural Capital Project Online Community <notifications@naturalcapitalproject.discoursemail.com> 于2022年5月31日周二 09:49写道:

Is there any chance that these negative values are very small and close to 0? Particularly in routed models, it’s possible for accumulated numerical error to cause very small (<-1e-5 or so) values close to 0 that are just numerical noise and nothing to worry about. But if the negative values are of a greater magnitude than that, we might want to take a closer look.