fire_exp_dir_multi {fireexposuR} | R Documentation |
Summarize or plot directional load for multiple values
Description
fire_exp_dir_multi()
summarizes the directional vulnerability
load for multiple points in a study area in a table or a plot.
Usage
fire_exp_dir_multi(exposure, values, plot = FALSE, full = FALSE, title, ...)
Arguments
exposure |
SpatRaster from |
values |
Spatvector of value as a point or simplified polygon |
plot |
Boolean, when |
full |
Boolean. Ignored when |
title |
(Optional) String. Ignored when |
... |
arguments passed to |
Details
This function summarizes multiple directional vulnerability assessments into a single table or plot. The plot is based on the methods presented in Beverly and Forbes 2023. For each degree, the frequency of input values with a continuous pathway at that trajectory is found. This summary can be useful in identifying trends in directional exposure to values within a regional area of interest.
Continuous pathways can be assessed for the full span of all three
directional assessment transect segments, or limited to the outer two
segments with the full
parameter. If the values being assessed are variable
sizes and being represented as points, it is recommended this parameter
remains set to FALSE
. The inner segment is sensitive to the size of the
value when a point is used. Adjusting the parameters for fire_exp_dir()
is
also supported. See details in fire_exp_dir()
for more information.
Value
a data.frame of the features with attributes: value featureID, degree, seg1 (binary), seg2 (binary), seg3 (binary), full (binary), outer (binary). Unless:
-
plot = TRUE
: a standardized plot as a ggplot object
References
Beverly JL, Forbes AM (2023) Assessing directional vulnerability to wildfire. Natural Hazards 117, 831-849. doi:10.1007/s11069-023-05885-3
Examples
# read example hazard data
hazard_file_path <- "extdata/hazard.tif"
hazard <- terra::rast(system.file(hazard_file_path, package = "fireexposuR"))
# generate 10 random example points within the hazard extent
e <- terra::buffer(terra::vect(terra::ext(hazard), crs = hazard), -15500)
points <- terra::spatSample(e, 10)
# compute exposure metric
exposure <- fire_exp(hazard)
# plot directional load for multiple points
fire_exp_dir_multi(exposure, points, plot = TRUE, interval = 10)