pptprism {acdcR}

Calculating precipitation by PRISM grids or Counties with PRISM raster

Description

The function calculates the precipitation (mm) by grids or counties directly from a PRISM raster.

Usage

pptprism(mmprism, year, out = NULL)

Arguments

mmprism

A PRISM raster of the precipitation

year

year of the PRIsM raster

out

Output value type: precipitation by PRISM grids or Counties (default = Counties)

Details

pptprism is a function for calculating precipitation (mm) by PRISM grids or Counties directly from a PRISM raster.

The out is to specify the output values.
- out = 'grid': precipitation by PRISM grids projected on the NLCD map
- out = 'stco': precipitation by Counties of 2017 Agricultural Census (default)
If out is not specified, 'stco' is set as default.

When out='stco' is specified, the weights are applied as:
- year < 2004: agricultural areas in 2001 NLCD
- year = 2004 or 2005: agricultural areas in 2004 NLCD
- year = 2006 or 2007: agricultural areas in 2006 NLCD
- year = 2008, 2009, or 2010: agricultural areas in 2008 NLCD
- year = 2011 or 2012: agricultural areas in 2011 NLCD
- year = 2013, 2014, or 2015: agricultural areas in 2013 NLCD
- year = 2016, 2017, or 2018: agricultural areas in 2016 NLCD
- year >= 2019: agricultural areas in 2019 NLCD

To get a PRIMS raster, follow the instruction at https://prism.oregonstate.edu/documents/PRISM_downloads_FTP.pdf.

Value

A data.frame including precipitation (ppt), PRISM grid numbers (gridNum), or FIPS codes (stco)

See Also

gddprism, grid2stco

Examples

#######################################################
## Note: Need a PRISM raster to run this code
#######################################################
## Not run: 
## PRISM data import
pptdata <- raster('./PRISM_ppt_stable_4kmD2_19960701_bil.bil')
## precipitation over Counties
result <- pptprism(pptdata,1996)
result2 <- pptprism(pptdata,1996,'stco')
## precipitation over PRISM grids
result3 <- pptprism(pptdata,1996,'grid')

## End(Not run)