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Download and process EarthEnv Topography layers

Source: R/topography.R
topography.Rd

This function downloads, processes, and extracts variables from the EarthEnv Topography dataset. This dataset provides global, cross-scale topographic variables suitable for biodiversity and ecosystem modeling.

Usage

topography(x, vars, algorithm = "md", topo_source = "GMTED", ...)

Arguments

x

The output from `par_set()` defining the area or locations for extraction, the reference system, and the buffer. Leave this empty and use `par_set()` to define parameters for download.

vars

Character vector of one or more variables to download and process.

algorithm

Character. The aggregation method/algorithm to use.

  • Common options: "md" (median, default), "mn" (mean), "min", "max", "sd".

  • Note: These codes directly affect the downloaded filename (e.g., _1KMmd_).

topo_source

Character. The source of the data.

  • "GMTED" (Global Multi-resolution Terrain Elevation Data) - Default.

  • "SRTM" (Shuttle Radar Topography Mission).

...

Additional arguments (currently unused).

Value

If `par_set()` contained a raster/polygon/points with buffer: a `SpatRaster` stack of processed variables. If `par_set()` contained spatial points or data.frame of points without buffer: a `data.frame` of x, y, and extracted values.

Details

Available variables (working synonyms in parentheses):

[Topography Variables]

  • 1 - "elevation" ([m]) ("dem", "height", "alt", "altitude")

  • 2 - "slope" ([degrees])

  • 3 - "aspect" ([degrees])

  • 4 - "roughness" ([Index]) ("rough")

  • 5 - "tri" ([Index]) ("terrain ruggedness index", "ruggedness")

  • 6 - "tpi" ([Index]) ("topographic position index", "position")

  • 7 - "vrm" ([Index]) ("vector ruggedness measure")

  • 8 - "pcurv" ([radians/m]) ("profile curvature", "profile curve")

  • 9 - "tcurv" ([radians/m]) ("tangential curvature", "tangential curve")

  • 10 - "eastness" ([Index]) ("east")

  • 11 - "northness" ([Index]) ("north")

Citation:
Amatulli G, Domisch S, Tuanmu M-N, Parmentier B, Ranipeta A, Malczyk J, Jetz W (2018). "A suite of global, cross-scale topographic variables for environmental and biodiversity modeling." Scientific Data 5, 180040. https://doi.org/10.1038/sdata.2018.40

Note: Please cite original sources of primary datasets where appropriate.

Examples

# \donttest{
# Example 1: Download elevation and slope for Italy
processed <- par_set(country = "Italy", crs = 3035) %>% 
  topography(vars = c("elevation", "slope"))
  # }