Get Map Unit Key (mukey) grid from SoilWeb Web Coverage Service (WCS)

Download chunks of the gNATSGO, gSSURGO, OCONUS SSURGO, STATSGO2, and RSS map unit key grid via bounding-box from the SoilWeb WCS.

Usage

mukey.wcs(
  aoi,
  db = c("gNATSGO", "gSSURGO", "RSS", "STATSGO", "fSSURGO", "PR_SSURGO", "HI_SSURGO"),
  res = NULL,
  quiet = FALSE
)

Arguments

aoi: area of interest (AOI) defined using a terra pakcage objects (SpatRaster, SpatVector, ext), sf objects (sf, sfc), raster package object (RasterLayer, bbox), sp package Spatial*, or a list, see details
db: character, mukey grid source, see details
res: grid resolution, leave as NULL to use native grid resolution, see details
quiet: logical, passed to curl::curl_download() to enable / suppress URL and progress bar for download.

Value

A SpatRaster (or RasterLayer) object containing indexed map unit keys and associated raster attribute table, or a try-error if the WCS request fails. Basic metadata are encoded into the resulting SpatRaster, accessible via terra::metags().

Details

When specified as a list, aoi should contain:

aoi: bounding-box specified as (xmin, ymin, xmax, ymax) e.g. c(-114.16, 47.65, -114.08, 47.68)
crs: coordinate reference system of BBOX, e.g. 'OGC:CRS84' (EPSG:4326, WGS84 Longitude/Latitude)

The WCS query is parameterized using a rectangular extent derived from the above AOI specification, after conversion to the native CRS (EPSG:5070) of the WCS grids.

Databases available from this WCS can be queried using WCS_details(wcs = 'mukey').

db	crs	description
ak_ssurgo	EPSG:3338	AK map unit keys
as_ssurgo	EPSG:4326	AS map unit keys
fssurgo	EPSG:5070	SSURGO/STATSGO2 map unit keys
gnatsgo	EPSG:5070	gNATSGO map unit keys
gssurgo	EPSG:5070	gSSURGO map unit keys
gu_ssurgo	EPSG:4326	GU map unit keys
hi_ssurgo	EPSG:6628	HI map unit keys
mp_ssurgo	EPSG:4326	MP map unit keys
pr_ssurgo	EPSG:32161	PR map unit keys
pw_ssurgo	EPSG:4326	PW map unit keys
rss	EPSG:5070	RSS map unit keys
statsgo	EPSG:5070	STATSGO2 map unit keys

The fSSURGO database is an unofficial hybrid of gSSURGO, back-filled with STATSGO2 data where SSURGO data are missing (e.b. denied access, NOTCOM, large misc. areas other than water).

The RSS mukey grid is 10m resolution. CONUS, AK, HI, and PR mukey grids are 30m resolution. AS, GU, MP, and PW use a geographic coordinate system with a grid size of approximately 30m.

Author

D.E. Beaudette and A.G. Brown

Examples

if (FALSE) { # \dontrun{
library(terra)

aoi <- list(aoi = c(-116.7400, 35.2904, -116.7072, 35.3026), crs = "EPSG:4326")
res <- mukey.wcs(aoi, db = 'gNATSGO') 
  
m <- unique(values(res))

prp <- setNames(
  get_SDA_property(
    c("ph1to1h2o_r", "claytotal_r"),
    "weighted average",
    mukeys = m,
    top_depth = 0,
    bottom_depth = 25,
    include_minors = TRUE,
    miscellaneous_areas = FALSE
  )[, c("mukey", "ph1to1h2o_r", "claytotal_r")],
  c("ID",    "pH1to1_0to25", "clay_0to25")
)

levels(res) <- prp
res2 <- catalyze(res)
res2

terra::plot(res2[['pH1to1_0to25']])
} # }