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Create Urban Greening Opportunities Raster

make_urban_greening_opportunities.Rd

This function generates an urban greening opportunities raster by integrating NDVI (Normalized Difference Vegetation Index), land use/land cover (LULC) classification or a pre-computed built areas raster, and urban heat intensity from SDEI/GHS data. It identifies urban pixels with high heat exposure and low greenness for targeted greening interventions.

Usage

make_urban_greening_opportunities(
  ndvi_raster,
  lulc_raster = NULL,
  lulc_product = c("esri_10m", "dynamic_world", "esa_worldcover", "local"),
  built_area_lulc_value = NULL,
  built_areas_raster = NULL,
  sdei_statistics,
  threshold = 0.1,
  pus,
  iso3,
  return_urban_areas = FALSE,
  output_path = NULL,
  cores = 4
)

Arguments

ndvi_raster

A SpatRaster representing NDVI values.

lulc_raster

Optional. A SpatRaster representing land use/land cover (LULC) classes. Required if built_areas_raster is not provided.

lulc_product

Character. LULC product used for class value lookups: "esri_10m" (default), "dynamic_world", "esa_worldcover", or "local". When "local", built_area_lulc_value must be explicitly provided.

built_area_lulc_value

Integer or NULL. LULC value representing built-up/urban areas. If NULL, automatically determined from lulc_product. Default is NULL.

built_areas_raster

Optional. A SpatRaster representing pre-classified binary built areas (1 = built, 0 = non-built). Skips internal classification from lulc_raster. Required if lulc_raster is not provided.

sdei_statistics

An sf object with urban heat exposure data (e.g., WBGT statistics).

threshold

Numeric. The fractional threshold (0–1) to classify planning units as urban after aggregation. Planning units with built area fraction above this threshold are considered urban. Default is 0.10.

pus

A SpatRaster defining the planning units.

iso3

Character. ISO3 country code used to subset sdei_statistics.

return_urban_areas

Logical. If TRUE, returns a two-layer stack with both greening opportunities and binary urban extent.

output_path

Optional. Directory path to save the resulting raster(s).

cores

Integer. Number of CPU cores to use (for future expansion, currently unused).

Value

A normalized SpatRaster representing urban greening opportunities. If return_urban_areas = TRUE, returns a raster stack with both the greening opportunities raster and the binary built areas raster.

Details

The built areas layer can be sourced either from a precomputed binary raster (built_areas_raster) or derived dynamically from a LULC raster (lulc_raster), which is classified on-the-fly to extract urban pixels. When aggregating built areas to planning units, fractional values are thresholded to generate a binary raster representing urban (1) and non-urban (0) planning units.

Examples

if (FALSE) { # \dontrun{
result <- make_urban_greening_opportunities(
  ndvi_raster = ndvi,
  built_areas_raster = built_binary,
  sdei_statistics = sdei,
  pus = planning_units,
  iso3 = "BRA"
)
} # }