12.2 Case Study: Landslide Susceptibility

This case study is based on a dataset of landslide locations in Southern Ecuador and described in detail in Muenchow, Brenning, and Richter (2012)

data("lsl", "study_mask", package = "spDataLarge")
ta = terra::rast(system.file("raster/ta.tif", package = "spDataLarge"))

str(lsl, give.attr = FALSE)

## 'data.frame':    350 obs. of  8 variables:
##  $ x          : num  713888 712788 713408 714888 715248 ...
##  $ y          : num  9558537 9558917 9560307 9560237 9557117 ...
##  $ lslpts     : Factor w/ 2 levels "FALSE","TRUE": 1 1 1 1 1 1 1 1 1 1 ...
##  $ slope      : num  33.8 39.4 37.5 31.5 44.1 ...
##  $ cplan      : num  0.02318 -0.03864 -0.01333 0.04093 0.00969 ...
##  $ cprof      : num  0.00319 -0.01719 0.00967 0.00589 0.00515 ...
##  $ elev       : num  2423 2052 1958 1969 3008 ...
##  $ log10_carea: num  2.78 4.15 3.64 2.27 3 ...

study_mask

## Simple feature collection with 1 feature and 1 field
## Geometry type: POLYGON
## Dimension:     XY
## Bounding box:  xmin: 712112.8 ymin: 9556864 xmax: 715794 ymax: 9560905
## Projected CRS: WGS 84 / UTM zone 17S
## # A tibble: 1 × 2
##   landuse                                                               geometry
##   <chr>                                                            <POLYGON [m]>
## 1 natural ((714111.8 9560805, 714118.6 9560805, 714172.2 9560812, 714227.2 9560…

ta

## class       : SpatRaster 
## dimensions  : 415, 383, 5  (nrow, ncol, nlyr)
## resolution  : 10, 10  (x, y)
## extent      : 711962.7, 715792.7, 9556862, 9561012  (xmin, xmax, ymin, ymax)
## coord. ref. : WGS 84 / UTM zone 17S (EPSG:32717) 
## source      : ta.tif 
## names       :    slope,      cplan,      cprof,     elev, log10_carea 
## min values  :  0.00000, -25.697536, -0.3194027, 1711.204,    2.000000 
## max values  : 76.17377,   4.267366,  0.1368342, 3164.165,    5.733915

12.2.1 Response Variable

landslide study area

12.2.2 Predictor Variables

slope: slope angle (\(^\circ\))
cplan: plan curvature (rad \(m^{−1}\)) expressing the convergence or divergence of a slope and thus water flow
cprof: profile curvature (rad \(m^{−1}\)) as a measure of flow acceleration, also known as downslope change in slope angle
elev: elevation m.a.s.l. (mean above sea level) as the representation of different altitudinal zones of vegetation and precipitation in the study area
log10_carea: the decadic logarithm of the catchment area (\(\log_{10} m^{2}\)) representing the amount of water flowing towards a location