Summarise habitat conversion from MapBiomas class areas — summarise

Aggregates a table of per-class areas into conservation groups and computes the percentage of converted (anthropic) versus remaining natural habitat.

Usage

summarise_conversion(
  class_areas,
  collection = 10,
  initiative = "brazil",
  water_in_denominator = FALSE
)

Arguments

class_areas: Either a data.frame with columns code and area_km2 (e.g. from mb_class_areas_gee) or a terra SpatRaster of MapBiomas codes (which is tabulated via mb_class_areas_raster).
collection: Integer collection number (default 10).
initiative: One of "brazil" (default), "amazonia" or "colombia"; selects the standardised legend context (see mb_legend).
water_in_denominator: Logical; if TRUE, water is treated as natural and included in the terrestrial denominator (default FALSE).

Value

A list with: converted_pct, natural_pct (terrestrial, the headline numbers), converted_pct_total, natural_pct_total, the group areas (natural_km2, anthropic_km2, water_km2, other_km2, not_observed_km2, total_km2) and by_class (the per-class table joined to the legend).

Details

The headline metrics use a terrestrial denominator (natural + anthropic), excluding water, not-observed and ambiguous "other" classes, which is the most defensible measure of habitat conversion. A total-area version (denominator = everything except not-observed) is also returned for transparency.

Examples

ca <- data.frame(code = c(3, 15, 24, 33), area_km2 = c(60, 30, 10, 5))
summarise_conversion(ca)$converted_pct
#> [1] 40