Classifies a landscape into slope-position and landform classes on the basis of the Topographic Position Index (TPI) and slope, following Weiss (2001) and Jenness (2006). Two classifications are offered: a six-class Slope Position Classification, based on one TPI scale, and a ten-class Landform Classification, based on a small and a large TPI scale. The TPI can be computed over square, circular or annular neighbourhoods, sized in cells or in map units, and standardised either over the whole grid (as in the original method) or locally. Results are returned as an object holding the classified raster, the TPI and slope surfaces, and per-class descriptive statistics, with methods for printing, summarising and plotting.
Topographic Position Index (TPI) based landform classification for R.
landform classifies a digital terrain model into slope-position classes
(valley, lower slope, flat, middle slope, upper slope, ridge) or into ten
landform classes (from canyons to mountain tops), following Weiss (2001) and
Jenness (2006). The TPI can be computed over square, circular or annular
neighbourhoods, sized in cells or in map units, and standardised over the whole
grid (as in the original method) or locally.
install.packages("landform")
library(landform)
dem <- malta_dtm()
# six-class Slope Position Classification, 9 x 9 cell window
sp <- landform(dem, scale = 9)
sp # class areas and percentages
plot(sp, shade = "slope")
# ten-class Landform Classification, circular neighbourhoods of 200 m and 1 km
lf <- landform(dem, class.type = "landform.classification",
sn = 200, ln = 1000, units = "map", shape = "circle")
plot(lf, what = "area")
See the vignette, vignette("landform"), for a full walk-through.
Jenness, J. (2006). Topographic Position Index (tpi_jen.avx) extension for ArcView 3.x, v. 1.2. Jenness Enterprises.
Weiss, A. (2001). Topographic Position and Landforms Analysis. Poster presentation, ESRI User Conference, San Diego, CA.