FCPolygon: Forest-Cover Polygon

Description Usage Arguments Details Value Author(s) References Examples

Description

This function can crop layers of Global Forest Change (GFC) using either Geographic Administrative Units (GADM) or other user-defined polygons.

Usage

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FCPolygon(pol = NULL, lyrs = c("treecover2000", "lossyear"), 
    multicore = TRUE, ...)

Arguments

pol

SpatialPolygonsDataFrame, character or NULL. A spatial-data polygon, the name of a GADM, or such a name plus its corresponding higher-level unit. If NULL then a list of GADM units is printed.

lyrs

character. Strings matching layers in a google api used to download links of GFC. Default 'treecover2000', and 'lossyear'.

multicore

logical. Use parallel execution. Default TRUE. This is ignored in Windows machines.

...

Additional arguments in getGADM other than 'unit.nm'. These could be 'level' and/or 'country'.

Details

The GADM are imported using the in-package getGADM. Links to the data sets are obtained using the in-package GFCurls. Geographic extents in both the GADM and the GFC are intersected using the package function HansenUrltoExtent. Common areas between GFC and GADM are cropped using two functions of the raster package: crop and rasterize. Depending on localization of the GADM unit, several GFC layers by data type might be required. This is done implementing the in-package FCMosaic. This function could be memory demanding if the extents of the polygons used to cut the GFC are big (30,000 km^2). For these cases, machines with RAM of 8 GB or greater should be used. In unix-alike systems, the package can implement parallel execution, see parallel package.

Value

list of rasters or set of GADM units

Author(s)

Wilson Lara <[email protected]>, Victor Gutierrez-Velez <[email protected]>

References

Hansen, M. C., Potapov, P. V., Moore, R., Hancher, M., Turubanova, S. A. A., Tyukavina, A., ... & Kommareddy, A. (2013). High-resolution global maps of 21st-century forest cover change. science, 342(6160), 850-853.

Examples

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## A list of departments of Colombia is printed:
 
     dep <- FCPolygon(level = 1)
     head(dep)
 
## Two adjacent layers of GFC must be bounded together before cropping
## the GFC data using the boundaries of the the municipality of
## 'Cumaribo' in Colombia. This is automatically developed by
## FCPolygon:
 
 cumariboArea <- FCPolygon(pol = 'Cumaribo')
 
## The name 'Mosquera' matchs two municipalities of Colombia. A
## corresponding department should be specified in the argument 'pol'
## of FCPolygon:
 
 mosquera <- FCPolygon('Mosquera')
 mosqueraNarinho <- FCPolygon(pol = c('Mosquera','Narino'))
 

forestChange documentation built on Feb. 20, 2019, 1:05 a.m.