soilDB (version 2.8.8)

fetchSOLUS: Fetch Soil Landscapes of the United States (SOLUS) Grids

Description

This tool creates a virtual raster or downloads data for an extent from Cloud Optimized GeoTIFFs (COGs) from the Soil Landscapes of the United States 100-meter (SOLUS100) soil property maps project repository.

Usage

fetchSOLUS(
  x = NULL,
  depth_slices = c(0, 5, 15, 30, 60, 100, 150),
  variables = c("anylithicdpt", "caco3", "cec7", "claytotal", "dbovendry", "ec", "ecec",
    "fragvol", "gypsum", "ph1to1h2o", "resdept", "sandco", "sandfine", "sandmed",
    "sandtotal", "sandvc", "sandvf", "sar", "silttotal", "soc"),
  output_type = c("prediction", "relative prediction interval",
    "95% low prediction interval", "95% high prediction interval"),
  grid = TRUE,
  samples = NULL,
  method = c("linear", "constant", "fmm", "natural", "monoH.FC", "step", "slice"),
  max_depth = 151,
  filename = NULL,
  overwrite = FALSE
)

Value

A SpatRaster object containing SOLUS grids for specified extent, depths, variables, and product types.

Arguments

x

An R spatial object (such as a SpatVector, SpatRaster, or sf object) or a SoilProfileCollection with coordinates initialized via aqp::initSpatial<-. Default: NULL returns the CONUS extent as virtual raster. If x is a SpatRaster the coordinate reference system, extent, and resolution are used as a template for the output raster.

depth_slices

character. One or more of: "0", "5", "15", "30", "60", "100", "150". The "depth slice" "all" (used for variables such as "anylithicdpt", and "resdept") is always included if any site-level variables are selected.

variables

character. One or more of: "anylithicdpt", "caco3", "cec7", "claytotal", "dbovendry", "ec", "ecec", "fragvol", "gypsum", "ph1to1h2o", "resdept", "sandco", "sandfine", "sandmed", "sandtotal", "sandvc", "sandvf", "sar", "silttotal", "soc".

output_type

character. One or more of: "prediction", "relative prediction interval", "95% low prediction interval", "95% high prediction interval"

grid

logical. Default TRUE returns a SpatRaster object for an extent. FALSE returns a SoilProfileCollection. Any other value returns a list object with names "grid" and "spc" containing both result objects.

samples

integer. Number of regular samples to return for SoilProfileCollection output. Default NULL will convert all grid cells to a unique profile. Note that for a large extent, this can produce large objects with a very large number of layers (especially with method other than "step").

method

character. Used to determine depth interpolation method for SoilProfileCollection output. Default: "linear". Options include any method allowed for approxfun() or splinefun() plus "step" and "slice". "step" uses the prediction depths as the top and bottom of each interval to create a piecewise continuous profile to maximum of 200 cm depth (for 150 cm upper prediction depth). "slice" returns a discontinuous profile with 1 cm thick slices at the predicted depths. Both "step" and "slice" return a number of layers equal to length of depth_slices, and all other methods return data in interpolated 1cm slices.

max_depth

integer. Maximum depth to interpolate 150 cm slice data to. Default: 151. Interpolation deeper than 151 cm is not possible for methods other than "step" and will result in missing values.

filename

character. Path to write output raster file. Default: NULL will keep result in memory (or store in temporary file if memory threshold is exceeded)

overwrite

Overwrite filename if it exists? Default: FALSE

Author

Andrew G. Brown

Details

If the input object x is not specified (NULL or missing), a SpatRaster object using the virtual URLs is returned. The full extent and resolution data set can be then downloaded and written to file using terra::writeRaster() (or any other processing step specifying an output file name). When input object x is specified, a SpatRaster object using in memory or local (temporary file or filename) resources is returned after downloading the data only for the target extent. In the case where x is a SoilProfileCollection or an sf or SpatVector object containing point geometries, the result will be a SoilProfileCollection for values extracted at the point locations. To return both the SpatRaster and SoilProfileCollection object output in a list, use grid = NULL.

References

Nauman, T. W., Kienast-Brown, S., Roecker, S. M., Brungard, C., White, D., Philippe, J., & Thompson, J. A. (2024). Soil landscapes of the United States (SOLUS): developing predictive soil property maps of the conterminous United States using hybrid training sets. Soil Science Society of America Journal, 88, 2046–2065. tools:::Rd_expr_doi("https://doi.org/10.1002/saj2.20769")

Examples

if (FALSE) {
b <- c(-119.747629, -119.67935, 36.912019, 36.944987)

bbox.sp <- sf::st_as_sf(wk::rct(
  xmin = b[1], xmax = b[2], ymin = b[3], ymax = b[4],
  crs = sf::st_crs(4326)
))

ssurgo.geom <- soilDB::SDA_spatialQuery(
  bbox.sp,
  what = 'mupolygon',
  db = 'SSURGO',
  geomIntersection = TRUE
)

# grid output
res <- fetchSOLUS(
  ssurgo.geom,
  depth_slices = "0",
  variables = c("sandtotal", "silttotal", "claytotal", "cec7"),
  output_type = "prediction"
)

terra::plot(res)

# SoilProfileCollection output, using linear interpolation for 1cm slices
# site-level variables (e.g. resdept) added to site data.frame of SPC
res <- fetchSOLUS(
  ssurgo.geom,
  depth_slices = c("0", "5", "15", "30", "60", "100", "150"),
  variables = c("sandtotal", "silttotal", "claytotal", "cec7", "resdept"),
  output_type = "prediction",
  method = "linear",
  grid = FALSE,
  samples = 10
)

# plot, truncating each profile to the predicted restriction depth
aqp::plotSPC(trunc(res, 0, res$resdept_p), color = "claytotal_p", divide.hz = FALSE)
}