examples/raster.R

In mfidino/uwinspatialtools: Summarises spatial data in a specified buffer around points for rasters and shapefiles

##############################################
#
# Example of extracting from landuse/landcover
#
# Written by T. Gallo and M. Fidino
#
##############################################

library(uwinspatialtools)

# Need a table of site locations
# Here I use a random sample of 10 Chicago sites as an example
# Data avaliable in same github repo
# Columns: LocationName, UTM_E, UTM_N, UTMZone, City
site_coords <- read.csv(
  "./examples/2019-04-25_SampleChicagoSites.csv",
  stringsAsFactors = FALSE
)

# Create spatial points
# You must put the correct CRS for respective city
sites <- sf::st_as_sf(
  site_coords,
  coords = c("UTM_E", "UTM_N"),
  crs = 26916
)

# We will use the High-res Landcover for NE Illinois for this example
#  Data can be downloaded from:
#  browseURL("https://datahub.cmap.illinois.gov/dataset/high-resolution-land-cover-ne-illinois-and-nw-indiana-2010")
#  Load iLULC map
# REPLACE FILE PATH WITH LOCAL FILE PATH

my_raster_path <-
  "D:/GIS/cmap/landcover_2010_chicagoregion.img"


# read it in
my_map <- terra::rast(my_raster_path)


#  For this example we will extract the proportion canopy cover (lulc class 1)
#    and create our own 'impervious cover' value, which is the sum of multiple
#    lulc classes.
lulc_prop <- extract_raster_prop(
  my_points = sites,
  location_column = "LocationName",
  my_buffer = 1000,
  my_raster_data = my_map,
  lulc_cats = list(
    "tree" = 1,
    "imperv" = 5:7,
    "fail" = 8
  )
)