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Compute Bioclimatic Variables from Monthly Climate Data

Source: R/bioclim.R, R/BioclimData.R
bioclim-variables.Rd

Computes the 19 standard bioclimatic variables (BIO01-BIO19) from monthly climate data following the WorldClim specification. This is an R implementation of the xbioclim C++ library.

Usage

bio01(tas, ...)

bio02(tasmax, tasmin, ...)

bio03(tasmax, tasmin, ...)

bio04(tas, ...)

bio05(tasmax, ...)

bio06(tasmin, ...)

bio07(tasmax, tasmin, ...)

bio08(tas, pr, ...)

bio09(tas, pr, ...)

bio10(tas, ...)

bio11(tas, ...)

bio12(pr, ...)

bio13(pr, ...)

bio14(pr, ...)

bio15(pr, ...)

bio16(pr, ...)

bio17(pr, ...)

bio18(tas, pr, ...)

bio19(tas, pr, ...)

bioclim(tas, tasmax, tasmin, pr, ...)

Arguments

tas

Numeric vector of length 12 or BioclimData: monthly mean temperature.

...

Additional arguments. For BioclimData inputs the argument na.rm is accepted: if TRUE, missing months are omitted and each BIO is computed from the available months (a quarter needs at least one valid month). The default na.rm = FALSE makes a pixel all-NA if any input month is NA.

tasmax

Numeric vector of length 12: monthly maximum temperature.

tasmin

Numeric vector of length 12: monthly minimum temperature.

pr

Numeric vector of length 12: monthly precipitation.

Value

  • For bio01–bio19 with plain numeric-vector inputs: a single numeric value.

  • For bioclim() with plain numeric-vector inputs: a named numeric vector of length 19 (names bio01–bio19).

  • For BioclimData inputs to bio01–bio19: a numeric vector with one value per pixel.

  • For BioclimData inputs to bioclim(): a numeric matrix with one row per pixel and 19 named columns (bio01–bio19).

Details

The 19 bioclimatic variables are:

  • BIO01: Mean Annual Temperature

  • BIO02: Mean Diurnal Range (mean of monthly (tasmax - tasmin))

  • BIO03: Isothermality (100 * BIO02 / BIO07)

  • BIO04: Temperature Seasonality (100 * population SD of monthly tas)

  • BIO05: Max Temperature of Warmest Month

  • BIO06: Min Temperature of Coldest Month

  • BIO07: Temperature Annual Range (BIO05 - BIO06)

  • BIO08: Mean Temperature of Wettest Quarter

  • BIO09: Mean Temperature of Driest Quarter

  • BIO10: Mean Temperature of Warmest Quarter

  • BIO11: Mean Temperature of Coldest Quarter

  • BIO12: Annual Precipitation

  • BIO13: Precipitation of Wettest Month

  • BIO14: Precipitation of Driest Month

  • BIO15: Precipitation Seasonality (CV)

  • BIO16: Precipitation of Wettest Quarter

  • BIO17: Precipitation of Driest Quarter

  • BIO18: Precipitation of Warmest Quarter

  • BIO19: Precipitation of Coldest Quarter

All functions accept either plain numeric vectors of length 12 (single pixel) or a BioclimData object holding a raster block (multiple pixels). When a BioclimData object is supplied, computation is delegated to the compiled C++ backend (xbioclim) and a numeric vector (one value per pixel) is returned.