spatialEco: sar – R documentation

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sar

Surface Area Ratio

Calculates the Berry (2002) Surface Area Ratio based on slope

sar(x, s = NULL, ...)

`x`	raster object
`s`	cell resolution (default is NULL, not needed if projection is in planar units)
`...`	Additional arguments passed to raster::calc

raster class object of Berry (2002) Surface Area Ratio

SAR is calculated as: resolution^2 * cos( (degrees(slope) * (pi / 180)) )

Jeffrey S. Evans <jeffrey_evans@tnc.org>

Berry, J.K. (2002). Use surface area for realistic calculations. Geoworld 15(9):20-1.

library(raster)
  data(elev)
  surface.ratio <- sar(elev, s=90)
  plot(surface.ratio)

Spatial Analysis and Modelling Utilities

v1.3-6

GPL-3

Authors

Jeffrey S. Evans [aut, cre], Melanie A. Murphy [ctb], Karthik Ram [ctb]

Initial release

2021-03-24