Produce a table of forest cover change statistics for a given AOI

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Description

For a given AOI, this function produces two tables: an annual forest loss table (in hectares, by default), and a table specifying 1) the total area of pixels that experienced forest gain and, 2) the total area of pixels that experienced both loss and gain over the full period (from 2000 through the end date of the specific product you are using, depending on the chosen data_year). Note that forest gain and combined loss and gain are not available in the GFC product on an annualized basis. Use extract_gfc to extract the GFC data for the AOI, and threshold it using threshold_gfc prior to running this function.

Usage

1
gfc_stats(aoi, gfc, scale_factor = 1e-04, data_year = 2015)

Arguments

aoi

one or more Area of Interest (AOI) polygon(s) as a SpatialPolygons* object. See Details.

gfc

extract of GFC product for a given AOI (see extract_gfc), recoded using threshold_gfc.

scale_factor

how to scale the output data (from meters). Defaults to .0001 for output in hectares.

data_year

which version of the Hansen data was used when

Details

If theaoi SpatialPolygons* object is not in the coordinate system of gfc, it will be reprojected. If there is a "label" attribute, it will be used to label the output statistics. Otherwise, unique names ("AOI 1", "AOI 2", etc.) will be generated and used to label the output. If multiple AOIs share the same labels, statistics will be provided for the union of these AOIs.

Value

list with two elements "loss_table", a data.frame with statistics on forest loss, and "gain_table", with the area of forest gain, and area that experienced both loss and gain. The units of the output are hectares (when scale_factor is set to .0001).

See Also

extract_gfc, threshold_gfc