The following vignette will demonstrate how to download, process, and
calculate covariates using amadeus
functions. The examples
will utilize air temperature at 2m height (“air.2m”) data from the NOAA
North American Regional Reanalysis (NARR) dataset.
Download data for years 2021 and 2022 with
download_data
.
<- tempdir()
dir download_data(
dataset_name = "narr",
variable = "air.2m",
year = c(2021, 2022),
directory_to_save = dir,
acknowledgement = TRUE,
download = TRUE,
remove_command = TRUE
)
Check for the downloaded files.
list.files(paste0(dir, "/air.2m"))
[1] "air.2m.2021.nc" "air.2m.2022.nc"
Process data for all dates from December 28, 2021 to January 3, 2022
with process_covariates
.
<- process_covariates(
temp_process covariate = "narr",
variable = "air.2m",
date = c("2021-12-28", "2022-01-03"),
path = paste0(dir, "/air.2m")
)
Check the processed SpatRaster
object.
temp_process
class : SpatRaster
dimensions : 277, 349, 7 (nrow, ncol, nlyr)
resolution : 32462.99, 32463 (x, y)
extent : -16231.49, 11313351, -16231.5, 8976020 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=lcc +lat_0=50 +lon_0=-107 +lat_1=50 +lat_2=50 +x_0=5632642.22547 +y_0=4612545.65137 +datum=WGS84 +units=m +no_defs
sources : air.2m.2021.nc:air (4 layers)
air.2m.2022.nc:air (3 layers)
varnames : air (Daily Air Temperature at 2 m)
air (Daily Air Temperature at 2 m)
names : air.2~11228, air.2~11229, air.2~11230, air.2~11231, air.2~20101, air.2~20102, ...
unit : K, K, K, K, K, K, ...
time : 2021-12-28 to 2022-01-03 UTC
Calculate covariates for North Carolina county boundaries with
calc_covariates
. County boundaries are accessed with the
tigris::counties
function. geom = TRUE
will
return the covariates as a SpatVector
object.
library(tigris)
<- calc_covariates(
temp_covar covariate = "narr",
from = temp_process,
locs = tigris::counties("NC", year = 2021),
locs_id = "NAME",
radius = 0,
geom = TRUE
)
Check the calculated covariates SpatVector
object.
temp_covar
class : SpatVector
geometry : polygons
dimensions : 700, 3 (geometries, attributes)
extent : 7731783, 8506154, 3248490, 3694532 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=lcc +lat_0=50 +lon_0=-107 +lat_1=50 +lat_2=50 +x_0=5632642.22547 +y_0=4612545.65137 +datum=WGS84 +units=m +no_defs
names : NAME time air.2m_0
type : <chr> <POSIXt> <num>
values : Chatham 2021-12-28 289.3
Alamance 2021-12-28 288.8
Davidson 2021-12-28 289.1