The process_gridmet() function imports and cleans raw gridded surface meteorological
data, returning a single SpatRaster object.
Usage
process_gridmet(
date = c("2023-09-01", "2023-09-10"),
variable = NULL,
path = NULL,
extent = NULL,
...
)Arguments
- date
character(1 or 2). Date (1) or start and end dates (2). Format YYYY-MM-DD (ex. September 1, 2023 = "2023-09-01").
- variable
character(1). Variable name or acronym code. See gridMET Generate Wget File for variable names and acronym codes. (Note: variable "Burning Index" has code "bi" and variable "Energy Release Component" has code "erc").
- path
character(1). Directory with downloaded netCDF (.nc) files.
- extent
numeric(4) or SpatExtent giving the extent of the raster if
NULL(default), the entire raster is loaded- ...
Placeholders.
Details
EDDI uses the same native GRIDMET multi-year workflow as SPEI.
Use eddi14d, eddi30d, eddi90d, eddi180d,
eddi270d, eddi1y, eddi2y, or eddi5y;
eddi defaults to eddi30d. Both indices retain the native
1/24-degree grid and five-day observation dates. Select dataset
gridmet in the wrapper functions to use these products; the
standalone drought source aliases continue to select their separate products.
GRIDMET SPEI uses native five-day observations, not daily values.
Use variable = "spei" (alias for "spei30d") or an explicit
accumulation code: "spei14d", "spei30d", "spei90d",
"spei180d", "spei270d", "spei1y", "spei2y",
or "spei5y". Set path to the code directory created by
download_gridmet() (e.g., spei30d). The multi-year file is subset
using its observation dates; no daily interpolation is performed.
Layer names retain the accumulation period (e.g., spei30d_20200105).
Examples
## NOTE: Example is wrapped in `\dontrun{}` as function requires a large
## amount of data which is not included in the package.
if (FALSE) { # \dontrun{
gridmet <- process_gridmet(
date = c("2023-01-01", "2023-01-10"),
variable = "Precipitation",
path = "./data/pr"
)
} # }