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Process CHELSA Climate Data for the IASDT

Source: R/DWF_CHELSA_process.R, R/DWF_CHELSA_prepare.R, R/DWF_CHELSA_project.R
CHELSA_data.Rd

Downloads, processes, and projects CHELSA climate data at the European scale for the Invasive Alien Species Digital Twin (IASDT). Supports multiple climate scenarios, outputting data in TIFF and NetCDF formats. Orchestrated by CHELSA_process(), with helper functions CHELSA_prepare() and CHELSA_project().

Usage

CHELSA_process(
  env_file = ".env",
  n_cores = 8L,
  strategy = "multisession",
  download = FALSE,
  overwrite = FALSE,
  download_attempts = 10L,
  sleep = 5L,
  other_variables = "npp",
  download_n_cores = 4,
  compression_level = 5,
  overwrite_processed = FALSE
)

CHELSA_prepare(
  env_file = ".env",
  download = FALSE,
  n_cores = 8L,
  strategy = "multisession",
  overwrite = FALSE,
  download_attempts = 10L,
  sleep = 5L,
  other_variables = "npp"
)

CHELSA_project(metadata = NULL, env_file = ".env", compression_level = 5L)

Arguments

env_file

Character. Path to the environment file containing paths to data sources. Defaults to .env.

n_cores

Integer. Number of CPU cores to use for parallel processing. Default: 8.

strategy

Character. The parallel processing strategy to use. Valid options are "sequential", "multisession" (default), "multicore", and "cluster". See future::plan() and ecokit::set_parallel() for details.

download

Logical. If TRUE, downloads CHELSA files. Default: FALSE.

overwrite

Logical. If TRUE, re-downloads existing files. Default: FALSE.

download_attempts

Integer. Maximum download retries. Default: 10.

sleep

Integer. Seconds to wait between download attempts. Default: 5.

other_variables

Character. Additional variables to process (e.g., "npp" for Net Primary Productivity alongside 19 bioclimatic variables bio1-bio19). Use "" for bioclimatic only. See CHELSA_variables for details. Default: "npp".

download_n_cores

Integer. Number of CPU cores to use for parallel downloading of CHELSA data. Only valid if download = TRUE. Defaults to 4.

compression_level

Integer. NetCDF compression level (1 = least, 9 = most). Default: 5.

overwrite_processed

Logical. If TRUE, overwrites processed files. Default: FALSE.

metadata

Tibble. Single-row metadata for input files, prepared by CHELSA_prepare()

Note

  • CHELSA_prepare() and CHELSA_project() are internal helpers, not for direct use.

  • Processes 19 bioclimatic variables (bio1–bio19) plus optional variables (e.g., NPP) for 46 scenarios (1 current, 45 future).

  • Time-intensive; depends on file size and compute resources.

Functions details

  • CHELSA_process(): Main function; optionally downloads CHELSA data, processes it to the European scale and reference grid, and saves TIFF and NetCDF outputs for 46 climate scenarios.

  • CHELSA_prepare(): Extracts metadata from local URL text files and manages optional downloads.

  • CHELSA_project(): Projects data to the IASDT reference grid with optional transformations.

Author

Ahmed El-Gabbas