wetness,GRaster-method {fasterRaster} | R Documentation |
Topographic wetness index
Description
This function creates a raster map with values equal to the topographic wetness index (TWI), which is a measure of how much overland water flow tends to accumulate in or flow away from a location.
Usage
## S4 method for signature 'GRaster'
wetness(x)
Arguments
x |
A |
Value
A GRaster
.
See Also
terrain()
, ruggedness()
, geomorphons()
, GRASS manual for tool r.topidx
(see grassHelp("r.topidx")
)
Examples
if (grassStarted()) {
# Setup
library(terra)
# Elevation raster
madElev <- fastData("madElev")
# Convert to GRaster:
elev <- fast(madElev)
# Topographic wetness index:
twi <- wetness(elev)
names(twi) <- 'TWI'
plot(c(elev, twi))
# Terrain ruggedness index:
tri <- ruggedness(elev)
tri7 <- ruggedness(elev, size = 7)
triSmooth7 <- ruggedness(elev, size = 7, exponent = 4)
tris <- c(elev, tri, tri7, triSmooth7)
names(tris) <- c("elevation", "TRI in 3x3", "TRI in 7x7", "Smoothed TRIin 7x7")
plot(tris)
}
[Package fasterRaster version 8.4.1.0 Index]