landslides {RSAGA}

Landslide inventory, study area mask and DEM

Description

Landslide data

Format

The landslides dataset consists of three objects:

1. landslides A dataframe of 1535 rows and 3 variables representing landslide initiation points in the Reserva Biologica San Francisco (RBSF) area of the tropical Andes in Southern Ecuador. The variables are:

   • lslpts landslide initiation point (boolean)

   • x and y Coordinates of coordinate reference system UTM zone 17S (EPSG: 32717)

   The landslide inventory was mapped by Stoyan (2000) in the field and by the presence of landslide scars in aerial imagery.

2. dem Digital elevation model given as a .Rd grid, i.e. a list consisting of the elements header (nine properties) and data (grid elevation values in m a.s.l.). The 10 m x 10 m digital elevation model was triangulated from aerial imagery as described by Jordan et al. (2005) and provided as a courtesy of Lars Ungerechts (2010).

3. study_area An sf-object representing the outlines of the natural part of the RBSF study area.

Details

Landslide data provided here are a subset of that used by Muenchow et al. (2012) to predict spatially landslide susceptibility using generalized additive models (GAMs). Specifically, the here provided landslides belong to the "natural" part of the RBSF area. Please refer also to the accompanying vignette for an introductory tutorial on the use of the RSAGA package for terrain analysis, geoprocessing, and model-building using these data.

Note

Please note that loading landslides overwrites existing objects named dem, landslides and study_area.

Source

DEM:

Ungerechts, L. (2010): DEM 10m (triangulated from aerial photo - b/w). Available online: http://vhrz669.hrz.uni-marburg.de/tmf_respect/data_pre.do?citid=901

Jordan, E., Ungerechts, L., Caceres, B. Penafiel, A. and Francou, B. (2005): Estimation by photogrammetry of the glacier recession on the Cotopaxi Volcano (Ecuador) between 1956 and 1997. Hydrological Sciences 50, 949-961.

Landslide Data:

Muenchow, J., Brenning, A., Richter, R. (2012): Geomorphic process rates of landslides along a humidity gradient in the tropical Andes, Geomorphology 139-140, 271-284. DOI: 10.1016/j.geomorph.2011.10.029.

Stoyan, R. (2000): Aktivitaet, Ursachen und Klassifikation der Rutschungen in San Francisco/Suedecuador. Unpublished diploma thesis, University of Erlangen-Nuremberg, Germany.

Examples

## Not run: 
library("RSAGA")
data(landslides)

# Print the DEM header:
dem$header

# Write the DEM to a SAGA grid:
write.sgrd(data = dem, file = "dem", header = dem$header, env = env)

# Calculate slope of DEM:
rsaga.slope(in.dem = "dem", out.slope = "slope", method = "poly2zevenbergen")

# Pick slope values at landslide points,
# added to landslides data.frame as variable "slope":
landslides <- pick.from.saga.grid(data = landslides,
                                  filename = "slope",
                                  varname = "slope")

## End(Not run)