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Download and process EarthEnv Freshwater Environmental Variables

Source: R/freshwater.R
freshwater.Rd

This function downloads, processes, and extracts variables from the Near-global freshwater-specific environmental variables dataset. These variables are available at 1 km resolution and capture upstream catchment characteristics, including topography, land cover, soil, and climate.

Usage

freshwater(x, vars, year = NULL, month = NULL, algorithm = NULL, ...)

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.

year

Numeric. Selected year(s) for extraction. Note that most EarthEnv freshwater variables are static layers (2015 version); this argument is primarily for consistency.

month

Numeric. Selected month(s) (1-12) for extraction. Only applicable to monthly variables (e.g., tmin, tmax, prec).

algorithm

Character. Aggregation method to filter specific bands.

  • For Elevation and Slope: "min" (Band 1), "max" (Band 2), "range" (Band 3), "avg" (Band 4).

  • For Flow Accumulation: "length" (Band 1), "acc" (Band 2).

  • For other variables: matches the string in the layer name.

...

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):

Temperature

  • 1 - "monthly_tmin_average.nc" ("monthly minimum temperature average", "min temp average", "tmin avg", "tmin")

  • 2 - "monthly_tmax_average.nc" ("monthly maximum temperature average", "max temp average", "tmax avg", "tmax")

  • 3 - "monthly_tmin_weighted_average.nc" ("monthly minimum temperature weighted", "min temp weighted", "tmin weighted")

  • 4 - "monthly_tmax_weighted_average.nc" ("monthly maximum temperature weighted", "max temp weighted", "tmax weighted")

Precipitation

  • 5 - "monthly_prec_sum.nc" ("monthly upstream precipitation sum", "precipitation sum", "precip sum", "prec")

  • 6 - "monthly_prec_weighted_sum.nc" ("monthly upstream precipitation weighted", "precipitation weighted", "precip weighted")

Hydroclimatic

  • 7 - "hydroclim_average+sum.nc" ("hydroclimatic variables average", "hydroclim average", "hydroclim")

  • 8 - "hydroclim_weighted_average+sum.nc" ("hydroclimatic variables weighted", "hydroclim weighted")

Topography

  • 9 - "elevation.nc" ("upstream elevation", "elevation", "dem")

  • 10 - "slope.nc" ("upstream slope", "slope")

  • 11 - "flow_acc.nc" ("stream length", "flow accumulation", "flow")

Land cover

  • 12 - "landcover_minimum.nc" ("upstream landcover minimum", "landcover min")

  • 13 - "landcover_maximum.nc" ("upstream landcover maximum", "landcover max")

  • 14 - "landcover_range.nc" ("upstream landcover range", "landcover range")

  • 15 - "landcover_average.nc" ("upstream landcover average", "landcover avg", "landcover")

  • 16 - "landcover_weighted_average.nc" ("upstream landcover weighted", "landcover weighted")

Geology & Soil

  • 17 - "geology_weighted_sum.nc" ("upstream geology", "geology weighted", "geology")

  • 18 - "soil_minimum.nc" ("upstream soil minimum", "soil min")

  • 19 - "soil_maximum.nc" ("upstream soil maximum", "soil max")

  • 20 - "soil_range.nc" ("upstream soil range", "soil range")

  • 21 - "soil_average.nc" ("upstream soil average", "soil avg", "soil")

  • 22 - "soil_weighted_average.nc" ("upstream soil weighted", "soil weighted")

Quality control

  • 23 - "quality_control.nc" ("quality control", "qc")

Citation:
Domisch S, Amatulli G, Jetz W (2015). "Near-global freshwater-specific environmental variables for biodiversity analyses in 1 km resolution." Scientific Data 2, 150073. https://doi.org/10.1038/sdata.2015.73

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

Examples

# \donttest{
# Topography with algorithm filtering (keeping only the average band)
processed <- par_set(country = "Switzerland", crs = 3035) %>% 
  freshwater(vars = c("elevation", "slope"), algorithm = "avg")

# Monthly Climate (January and July)
processed <- par_set(country = "Italy", crs = 3035) %>% 
  freshwater(vars = "tmin", month = c(1, 7))
# }