Biophysical table for Annual Water Yield

Hello!
from the biophysical table of annual water yield, there are three parameters that I do not understand: eff_p, load_p and critical_len_p, can someone briefly explain them and also how to determine them or recommend relevant literature.
Regards!

Hi @Popza, The fields eff_p, load_p and crit_len_p aren’t used by the Annual Water Yield model at all! They’re included in the biophysical table here because we use the same sample biophysical table in NDR (which does use these extra columns), as well as SDR.

So, if you’re curious about how the columns are used in NDR, you can take a look at the NDR documentation here: https://storage.googleapis.com/releases.naturalcapitalproject.org/invest-userguide/latest/ndr.html#data-needs

But otherwise, you don’t need to worry about these columns for the Annual Water Yield model.

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Hi @Popza -

In the freshwater sample data (which I’m guessing you’re referring to), the biophysical table for Annual Water Yield (as well as NDR and SDR) actually contains parameters for 3 models - NDR, SDR and Annual Water Yield. Only root_depth, Kc and LULC_veg are used by Annual Water Yield, the other parameters are for NDR and SDR, so you don’t need to worry about them, or have them in your biophysical table, if you’re only running AWY.

~ Stacie

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Thank you guys for clarification, what got me confused is the biophysical table I found from the sample datasets I downloaded, I was also wondering why are these parameters so necessary for AWY. Thanks!