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Identify escape/safety points where roads cross the hazard-zone boundary

Source: R/grid_region_escape.R
find_escape_points.Rd

Intersects a road/pathway network with the boundary of the hazard zone and converts the intersection geometry to points. These points represent candidate exits from the hazard zone.

Usage

find_escape_points(
  hazard_zone,
  roads,
  study_area = NULL,
  region_buffer_m = 5000
)

Arguments

hazard_zone

Hazard/evacuation zone.

roads

Road/pathway network.

study_area

Optional local study area used to crop candidate escape points to a broader region around the study area.

region_buffer_m

Buffer distance passed to make_region_area() when study_area is supplied.

Value

A point SpatVector of candidate escape/safety points.

Examples

r <- terra::rast(nrows = 4, ncols = 4, xmin = 0, xmax = 4, ymin = 0, ymax = 4,
  vals = 1, crs = "EPSG:3857")
zone <- terra::as.polygons(r, dissolve = TRUE)
roads <- terra::vect(matrix(c(-1, 2, 5, 2), ncol = 2, byrow = TRUE),
  type = "lines", crs = "EPSG:3857")
find_escape_points(zone, roads)
#> class       : SpatVector
#> geometry    : points
#> dimensions  : 2, 0  (geometries, attributes)
#> extent      : 0, 4, 2, 2  (xmin, xmax, ymin, ymax)
#> coord. ref. : WGS 84 / Pseudo-Mercator (EPSG:3857)