Reclassify natural disturbance and harvest layers

Classify disturbances that have occurred in a user defined time period. The output from this function can be used as either the natDist or anthroDist inputs for caribouMetrics() or disturbanceMetrics().

reclassDist(distYr, endYr = 0, numCumYrs, template, dateField)

Arguments

distYr

sf object, SpatRaster or RasterLayer. A simple feature collection or raster layer covering the focal area and including the year of disturbance or time since disturbance as well as geometry (multipolygon) of the disturbance.

endYr

numeric default 0. Four digit year indicating the latest year to include from distYr. If 0 assume dateField values indicate time since disturbance.

numCumYrs

numeric. Number of years before endYr to include.

template

SpatRaster or RasterLayer. A raster of the focal region, used as a template to which disturbance information is projected. This layer's dimensions determine the dimensions of the output. It is recommended to use the landCover raster layer used in caribouMetrics() or disturbanceMetrics() to ensure equal dimensions

dateField

character. Name of the column in which disturbance year/time since disturbance is recorded.

Value

Returns a binary SpatRaster with the same dimensions as the template input. Values of 1 represent areas of disturbance

See also

Functions for calculating disturbance: DisturbanceMetrics-class, disturbanceMetrics(), results(), updateDisturbance()

Examples

library(sf)
#> Linking to GEOS 3.10.2, GDAL 3.4.1, PROJ 8.2.1; sf_use_s2() is TRUE
# create template raster
lc <- terra::rast(nrows = 10, ncols = 10, xmin = 0, xmax = 10, ymin = 0,
                  ymax = 10, crs = "EPSG:5070")

# create fire polygons 
corners <- matrix(c(0,0,10,10,5, 0,10,10,0,5), ncol = 2)

fireYr <- st_sf(FIRE_YEAR = c(1990, 2000, 2009, 2015),
                     geometry = st_sfc(st_polygon(list(corners[c(1,2,5, 1),])),
                                       st_polygon(list(corners[c(2,3,5, 2),])),
                                       st_polygon(list(corners[c(3,4,5, 3),])),
                                       st_polygon(list(corners[c(4,1,5, 4),])))) 
fireYr <- st_set_crs(fireYr, 5070)

# three polygons should be considered disturbed (1) but the 2015 polygon should
# not (0)
cumFirePresence <- reclassDist(fireYr,
                               endYr = 2010,
                               numCumYrs = 40,
                               template = lc,
                               dateField = "FIRE_YEAR")

plot(cumFirePresence)


# with time since disturbance
fireYr$FIRE_YEAR <- c(50, 15, 10, 20)
cumFirePresence2 <- reclassDist(fireYr,
                               endYr = 0,
                               numCumYrs = 40,
                               template = lc,
                               dateField = "FIRE_YEAR")
                               
plot(cumFirePresence2)