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Broken links for data inputs to the NDR and SDR models

G'Morning InVest Gurus,

You may be interested to know that the online Invest User guide data link for Nutrient Loading coefficients from the NDR is broken. There are similar problems with the SDR model data section. The link in the SDR for rainfall erosivity that promises to take the modeler of a vector format map of R values for the US "The EPA has created a digital map that is available at . " takes the querant to a page with administrator biographies and a summary of departmental responsibilities with no clear link to the promised map.

I have resolved the Nutrient Loading Coefficient issue by rooting through relevant scholarship .(BTW the USEPA does seem to have a data set on air borne contaminant deposition that contains nitrogen and phosphorus species.) However, I have not as of yet found an alternate to the erosivity map.

It would be so wonderful if you could help me find the EPA erosivity map described in the user guide.

Thanks HDL 


  • swolnyswolny Member, NatCap Staff
    Hm, it doesn't seem to be available any more. Such is the fickleness of data providers. You could always get the PDF and digitize, but what we generally do for erosivity in the US is to calculate it from an annual precipitation map, using Equation 11 given in this paper by Renard and Freimund (1994)

    ~ Stacie
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