Download and crop data from the NRCS SSURGO soils database.
Source:R/SSURGO_FUNCTIONS.R
get_ssurgo.Rd
This is an efficient method for spatially merging several different soil survey areas as well as merging their tabular data.
Arguments
- template
An
Simple Feature
orSpatRaster
object to serve as a template for cropping. Optionally, a vector of area names, e.g.,c('IN087','IN088')
may be provided.- label
A character string naming the study area.
- raw.dir
A character string indicating where raw downloaded files should be put. The directory will be created if missing. Defaults to './RAW/SSURGO/'.
- extraction.dir
A character string indicating where the extracted and cropped SSURGO shapefiles should be put. The directory will be created if missing. Defaults to './EXTRACTIONS/SSURGO/'.
- force.redo
If an extraction for this template and label already exists, should a new one be created? Defaults to FALSE.
Details
get_ssurgo
returns a named list of length 2:
'spatial': A
Simple Feature
of soil mapunits in the template, and'tabular': A named list of
data.frames
with the SSURGO tabular data.
Examples
if (FALSE) { # \dontrun{
# Get the NRCS SSURGO data (USA ONLY)
SSURGO.MEVE <- get_ssurgo(template = FedData::meve, label = "meve")
# Plot the VEP polygon
plot(meve$geometry)
# Plot the SSURGO mapunit polygons
plot(SSURGO.MEVE$spatial, lwd = 0.1, add = T)
# Or, download by Soil Survey Area names
SSURGO.areas <- get_ssurgo(template = c("CO670", "CO075"), label = "CO_TEST")
# Let's just look at spatial data for CO675
SSURGO.areas.CO675 <- SSURGO.areas$spatial[SSURGO.areas$spatial$AREASYMBOL == "CO075", ]
# And get the NED data under them for pretty plotting
NED.CO675 <- get_ned(template = SSURGO.areas.CO675, label = "SSURGO_CO675")
# Plot the SSURGO mapunit polygons, but only for CO675
plot(NED.CO675)
plot(SSURGO.areas.CO675, lwd = 0.1, add = T)
} # }