# Example coefficients for nutrient objectives in RIOS? [load_n, eff_n, load_p, eff_p]

I want to run RIOS for the nitrogen and phosphorus objectives with the default lulc biophysical table coefficients, but I can't seem to see these columns in the example data (they are found in the Gura example files for RIOS). Are they necessary for RIOS to run? If so, are there example values for these parameters to tie in with the default lulc table?

Many thanks in advance!

Leon

## Comments

To tag on a question to that: RIOS uses N_exp, N_ret, P_exp, P_ret to estimate where on the landscape to place investment in activities. However when we translate this output activity map to a new LULC to run in InVEST we now need a different set of variables in our biophysical table:

Load_n,

Eff_n,

Load_p,

Eff_p

...is that correct? Unfortunately there seems to be low correspondence between the LULC classes provided in the default RIOS biophysical table and those in the default Water Model biophysical tables. Do you know where these best looked for in the literature?

Many thanks!

Sylvie

The InVEST Nutrient Retention model requires the coefficients load_n, eff_n and/or load_p and eff_p. RIOS requires a similar set of values, just with different names: n_exp, n_ret and/or p_exp and p_ret. So you can use the RIOS values in the Nutrient Retention model for your base LULC classes, but will need to calculate new values for the <old LULC>-><activity> combinations output by RIOS.

The default coefficients provided in RIOS are global averages, and while it's ok to use them to get started, we strongly recommend doing a literature search to try and find values that are more specific to your area, especially if you're using the result for any sort of decision-making, peer-reviewed research, etc. The coefficients provided with the sample data for the water models also should not be used for decision-making.

A literature search is a time-consuming but very typical part of InVEST modeling. The InVEST User Guide provides some pointers to literature to get you started. We also have a database of nutrient and sediment values from literature that we've found over time, and you can look through it for sources that might be relevant.

~ Stacie