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Summarise the impact of ORDs on a density decay map

summarise_ORD_impact.Rd

Calculates the percentage of a density decay (DD) map contained within ORD footprints and buffer zones, together with the percentage affected by ORD barrier ("shadow") effects.

Usage

summarise_ORD_impact(
  DD_map,
  ORDpolys_with_buffer,
  DBS_map,
  DBS_withORDs,
  smalltol = 0.01
)

Arguments

DD_map

A normalised density decay RasterLayer.

ORDpolys_with_buffer

An sf polygon object containing ORD footprints and associated buffer zones.

DBS_map

A RasterLayer containing Distance By Sea values calculated without ORDs.

DBS_withORDs

A RasterLayer containing Distance By Sea values calculated with ORDs present.

smalltol

Numeric threshold used to identify meaningful increases in Distance By Sea. Defaults to 0.01.

Value

A data frame with two columns:

pc_in_ORD_plus_buffer

Percentage of the DD map contained within ORD footprints and their buffer zones.

pc_in_ORD_shadow

Percentage of the DD map located within areas where Distance By Sea increases by more than smalltol due to the presence of ORDs.

Details

If the density decay map is normalised to sum to one, both outputs can be interpreted directly as percentages of the total density distribution.

Examples

if (FALSE) {
summarise_ORD_impact(
  DD_map = DD_map,
  ORDpolys_with_buffer = ORDpolys_with_buffer,
  DBS_map = DBS_map,
  DBS_withORDs = DBS_withORDs
)
}