Functions to load and flatten commonly used tables and from SSURGO file geodatabases, and create soil profile collection objects (SPC).

get_component_from_GDB(
  dsn = "gNATSGO_CONUS.gdb",
  WHERE = NULL,
  childs = FALSE,
  droplevels = TRUE,
  stringsAsFactors = NULL
)

get_legend_from_GDB(
  dsn = "gNATSGO_CONUS.gdb",
  WHERE = NULL,
  droplevels = TRUE,
  stringsAsFactors = NULL,
  stats = FALSE
)

get_mapunit_from_GDB(
  dsn = "gNATSGO_CONUS.gdb",
  WHERE = NULL,
  droplevels = TRUE,
  stringsAsFactors = NULL,
  stats = FALSE
)

fetchGDB(
  dsn = "gNATSGO_CONUS.gdb",
  WHERE = NULL,
  childs = FALSE,
  droplevels = TRUE,
  stringsAsFactors = NULL
)

Arguments

dsn

data source name (interpretation varies by driver - for some drivers, dsn is a file name, but may also be a folder, or contain the name and access credentials of a database); in case of GeoJSON, dsn may be the character string holding the geojson data. It can also be an open database connection.

WHERE

text string formatted as an SQL WHERE clause (default: FALSE)

childs

logical; if FALSE parent material and geomorphic child tables are not flattened and appended

droplevels

logical: indicating whether to drop unused levels in classifying factors. This is useful when a class has large number of unused classes, which can waste space in tables and figures.

stringsAsFactors

deprecated

stats

Return statistics (number of mapunit keys per legend; number of components, major components per mapunit, total and hydric component percentage)? Default: FALSE

Value

A data.frame or SoilProfileCollection object.

Details

These functions return data from SSURGO file geodatabases with the use of a simple text string that formatted as an SQL WHERE clause (e.g. WHERE = "areasymbol = 'IN001'". Any columns within the target table can be specified (except for fetchGDB() which currently can only target one table (e.g. legend, mapunit or component) at a time with the WHERE clause).

Author

Stephen Roecker

Examples


# \donttest{

## replace `dsn` with path to your own geodatabase (SSURGO OR gNATSGO)
##
##
##  download CONUS gNATSGO from here:
##    https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcseprd1464625
##
##
# dsn <- "D:/geodata/soils/gNATSGO_CONUS.gdb"

# le <- get_legend_from_GDB(dsn = dsn, WHERE = "areasymbol LIKE '%'")

# mu <- get_mapunit_from_GDB(dsn = dsn, WHERE = "muname LIKE 'Miami%'")

# co <- get_component_from_GDB(dsn, WHERE = "compname = 'Miami'
#                              AND majcompflag = 'Yes'", childs = FALSE)

# f_in_GDB <- fetchGDB(WHERE = "areasymbol LIKE 'IN%'")

# }