fasterRaster (version 8.4.0.5)

wetness,GRaster-method: 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 GRaster
wetness(x)

Value

A GRaster.

Arguments

x

A GRaster (typically representing elevation). The raster must be projected (i.e., not in WGS84, NAD83, et cetera).

See Also

terrain(), ruggedness(), geomorphons(), GRASS manual for module r.topidx (see grassHelp("r.topidx"))

Examples

if (grassStarted()) {

# Setup
library(terra)

# Elevation raster
madElev <- fastData("madElev")

# Convert to GRaster:
elev <- fast(madElev)

# Terrain ruggedness index:
tri <- ruggedness(elev)
plot(c(elev, tri))

# Topographic wetness index:
twi <- wetness(elev)
plot(c(elev, twi))

}