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Download land cover data

Source: R/download.R
download_nlcd.Rd

The download_nlcd() function accesses and downloads annual land cover data from the Multi-Resolution Land Characteristics (MRLC) Consortium's National Land Cover Database (NLCD) products data base.

Usage

download_nlcd(
  product = "Land Cover",
  year = 2021,
  directory_to_save = NULL,
  acknowledgement = FALSE,
  download = FALSE,
  remove_command = FALSE,
  hash = FALSE
)

Arguments

product

character(1). "Land Cover", "Land Cover Change", "Land Cover Confidence", "Fractional Impervious Surface", "Impervious Descriptor", or "Spectral Change Day of Year ".

year

integer(1). Available years for Coterminous United States range from 1985 to 2023.

directory_to_save

character(1). Directory to save data. Two sub-directories will be created for the downloaded zip files ("/zip_files") and the unzipped shapefiles ("/data_files").

acknowledgement

logical(1). By setting TRUE the user acknowledges that the data downloaded using this function may be very large and use lots of machine storage and memory.

download

logical(1). FALSE will generate a *.txt file containing all download commands. By setting TRUE the function will download all of the requested data files.

remove_command

logical(1). Remove (TRUE) or keep (FALSE) the text file containing download commands.

hash

logical(1). By setting TRUE the function will return an rlang::hash_file() hash character corresponding to the downloaded files. Default is FALSE.

Value

  • For hash = FALSE, NULL

  • For hash = TRUE, an rlang::hash_file character.

  • Zip and/or data files will be downloaded and stored in respective sub-directories within directory_to_save.

References

Dewitz J (2023). “National Land Cover Database (NLCD) 2021 Products.” doi:10.5066/P9JZ7AO3 .
Dewitz J (2024). “National Land Cover Database (NLCD) 2019 Products (ver. 3.0, February 2024).” doi:10.5066/P9KZCM54 .

Author

Mitchell Manware, Insang Song

Examples

if (FALSE) { # \dontrun{
download_nlcd(
  product = "Land Cover",
  year = 2021,
  directory_to_save = tempdir(),
  acknowledgement = TRUE,
  download = FALSE # NOTE: download skipped for examples
)
} # }