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Rainfall Erosivity Index (R) for Sediment Delivery Ratio model


I have daily precipitation data and struggling to find a detailed explanation to construct 'Rainfall Erosivity Index' rasters. My study area is east coast of US. Please suggest if there any tools or script available for the construction of R rasters.



  • PerrinePerrine Moderator, NatCap Staff
    Hi Ibe, 

    Good news that your study is in the US, there are more erosivity data readily available here!

    Another approach is to use the Modified Fournier Index based on monthly precipitation data, as suggested by Renard et al. (1994). The way I've done it in the past is to calculate the R-factors for the rain gages and then interpolate (inverse distance weighting method) to obtain a raster.

    Please also check this thread for more details on this method and for unit conversions.


    Renard, K., & Freimund, J. (1994). Using monthly precipitation data to estimate the R-factor in the revised USLE. Journal of Hydrology, 157, 287–306. 
  • IbeIbe Member
    Hi Perrine,

    Thanks for very useful information. I found a package developed for RUSLE but it will require generation of geodatabase files to include as part of it. Slightly tedious. On the other hand, I am wondering if you wrote a code or know of a script which i can modify for my use with daily precipitation time series data. Please let me know.

  • IbeIbe Member
    Never mind. I used equations 11 and 12 in Renard & Freimund's (1994) to compute it. It was fairly straightforward. 

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