rusleR

This package offers an R implementation of Universal Soil Loss Equation (USLE). You can find here a collection of functions to estimate main factors: R-factor, K-factor, LS-factor and C-factor. The package usesterra and Rsagacmd in the background. SAGA GIS need to be installed on your machine as well.

Disclaimer! This package is under development right now. It was tested on Windows 10 only. However, its operability fully depends on terra and Rsagacmd packages. Therefore it is expected that rusleR should work on Linux-based machines as well.

Installation

You can install the development version of rusleR from GitHub with:

# install.packages("devtools")
devtools::install_github("atsyplenkov/rusleR")

Example

The brief introduction to the rusleR package were made at the IAHS-WasWac workshop in December 2022. You can see it on YouTube:

LS-factor

This is a basic example which shows you how to calculate LS_alpine (Schmidt et al., 2019):

library(rusleR)
library(Rsagacmd)
library(terra)

# initiate a saga object
saga <- saga_gis(raster_backend = "terra")

# load DEM
f <- system.file("extdata/dem.tif", package="rusleR")
DEM <- rast(f)

# calculate LS-alpine
ls <- ls_alpine(dem = DEM)

As a result of ls_alpine() you receive a SpatRaster object:

ls
#> class       : SpatRaster 
#> dimensions  : 78, 54, 1  (nrow, ncol, nlyr)
#> resolution  : 27.30756, 27.30756  (x, y)
#> extent      : 337615.4, 339090, 4814626, 4816756  (xmin, xmax, ymin, ymax)
#> coord. ref. : WGS 84 / UTM zone 38N (EPSG:32638) 
#> source(s)   : memory
#> name        : LSalpine 
#> min value   :   0.0000 
#> max value   : 660.0054

R-factor

With the help of get_glored() function you can quickly download and crop to AOI a Global Rainfall Erosivity Database map (GLORED). It was created by Panagos et al. (2017) based on in-situ measurements from 3,625 stations. This GLORED was used to develop a global erosivity map at 30 arc-seconds(~1 km) based on a Gaussian Process Regression(GPR).

library(rusleR)
library(terra)

f <- system.file("extdata/extent.shp", package="rusleR")
v <- vect(f)

r_factor <- get_glored(v)

As a result of get_glored() you receive a SpatRaster object:

r_factor
#> class       : SpatRaster 
#> dimensions  : 2, 2, 1  (nrow, ncol, nlyr)
#> resolution  : 809.8197, 809.8197  (x, y)
#> extent      : 337544.9, 339164.5, 4814761, 4816381  (xmin, xmax, ymin, ymax)
#> coord. ref. : +proj=utm +zone=38 +datum=WGS84 +units=m +no_defs 
#> source(s)   : memory
#> name        :      out 
#> min value   : 682.1308 
#> max value   : 820.8951

Citation

While rusleR does not redistribute the data or provide it in any way, we encourage users to cite original papers when using this package. E.g. to cite Panagos et al. (2017) when using GLORED, Hengl et al. (2017) when using SoilGrids and Schmidt et al. (2019) when using LS_alpine:

Panagos, Panos, Pasquale Borrelli, Katrin Meusburger, Bofu Yu, Andreas Klik, Kyoung Jae Lim, Jae E. Yang, et al. “Global Rainfall Erosivity Assessment Based on High-Temporal Resolution Rainfall Records.” Scientific Reports 7, no. 1 (June 23, 2017): 4175. https://doi.org/10.1038/s41598-017-04282-8.

Hengl, Tomislav, Jorge Mendes de Jesus, Gerard B. M. Heuvelink, Maria Ruiperez Gonzalez, Milan Kilibarda, Aleksandar Blagotić, Wei Shangguan, et al. “SoilGrids250m: Global Gridded Soil Information Based on Machine Learning.” PLOS ONE 12, no. 2 (February 16, 2017): e0169748. https://doi.org/10.1371/journal.pone.0169748.

Schmidt, Simon, Simon Tresch, and Katrin Meusburger. “Modification of the RUSLE Slope Length and Steepness Factor (LS-Factor) Based on Rainfall Experiments at Steep Alpine Grasslands.” MethodsX 6 (2019): 219–29. https://doi.org/10.1016/j.mex.2019.01.004.

To-do list

• K-factor functions
• Watem/Sedem functions
• Vignettes
• tidy-loader disclaimer (see tidyterra package)
• New radar-based R factor (https://esdac.jrc.ec.europa.eu/themes/satellite-based-global-r-factor)
• SDR estimation (see Batista et al., 2021)
• Connectivity index (see Borselli et al., 2008)
• IC by Cavalli et al., 2013
• SDR by Vigiak et al., 2012
• C-factor????
• Should I use WhiteboxGeo tools in a backend instead of SAGA??

ACKNOWLEDGEMENTS

This package was developed in accordance to the Development program of the Interdisciplinary Scientific and Educational School of M.V. Lomonosov Moscow State University “Future Planet and Global Environmental Change”