Geographic Projection
Files for bulk density
Files for bulk density
Data set reference code -- 1996-0128
To accommodate users with a variety of GIS software, the data giving the
bulk density are available in several different formats.
The files needed by each of the types of user below are described
separately.
NOTE -- Most of these files have been compressed using
the GNU gzip program, as indicated by the .gz file
extension. Users who do not have access to the gunzip
decompression program can request that files be uncompressed prior to
transfer via ftp. In some cases, however, the uncompressed file may be
very much larger than the compressed version, greatly increasing file
transfer time.
The orginal STATSGO mapunits for the 48 states have been merged into a
single Arc/Info polygon (vector) coverage. The bulk density for each
standard layer of each mapunit is given by the INFO table MU_BD, which
may be RELATEd to the mapunit coverage using "MUID" as the relate item.
The needed files are
-
mu_poly.e00.gz (101 Mbyte, uncompresses to 269 Mbyte)
- Mapunit polygon coverage in Arc/Info EXPORT format.
-
mu_bd.e00.gz (264 kbyte, uncompresses to 1.3 Mbyte)
- INFO table giving mean bulk density for each standard layer of each
mapunit, in Arc/Info EXPORT format.
-
stdlayer.e00
- INFO table defining the 11 standard soil layers for which the mean
bulk density was computed.
The mapunits have been gridded at 30-arcsec cell size. The value attribute
table (VAT) for the Arc/Info grid listed below contains the mapunit
indentifier, MUID, the mapunit serial number, MUSERIAL, the mean depth
to bedrock, ROCKDEPM, and the mean bulk density for each of the 11
standard soil layers.
Warning -- The uncompressed version of the grid file
below is very much larger than the compressed version.
-
bdgrid.e00.gz (10.6 Mbyte, uncompresses to 192 Mbyte)
- 30-arcsec grid giving bulk density, in Arc/Info grid format.
-
stdlayer.e00
- INFO table defining the 11 standard soil layers for which the mean
bulk density was computed.
The 30-arcsec gridded data are also available as a three-dimensional array of
16-bit unsigned binary integers, where each integer value represents the
bulk density multiplied by 100. The data are organized as eleven
two-dimensional layers, giving, respectively, mean BD for each of the 11
standard soil layers. Within each layer, the values are arranged by
horizontal rows. All values for the first layer are given first,
starting with the value for the left (western) end of the top
(northern-most) row, and continuing left to right along the row. The
data for the last row of the first layer are then followed by the top
row of the second layer, and so on.
The array contains 11 layers each containing 2984 rows of 6936 values.
Code for reading the binary array is available in Fortran 77
and C.
Warning -- The uncompressed version of the BSQ file
below is very much larger than the compressed version.
-
bd.bsq.gz (26 Mbyte, uncompresses to 455 Mbyte)
- Three-dimensional array of 16-bit unsigned integer values for
mean bulk density for each standard layer of each grid cell.
-
stdlayer.ascii
- Table defining the 11 standard soil layers for which the mean bulk
density was computed.
The same array is also available in LAS format (files bd.img.gz and
bd.ddr).
The file systems containing the datasets are cross-mounted on the local
ESSC computer network. Local Arc/Info users may find it more convenient
to copy necessary files directly to their own workspaces using the
Arc/Info COPY and COPYINFO commands. The needed directories and files
(under directory $DSREF/1996-0128/) are
- bdgrid
- Arc/Info grid giving mean bulk density for each standard soil layer
for each 30-arcsec grid cell.
- ../mapunits/mu_poly
- Arc/Info coverage containing polygon version of mapunit boundaries.
- info!MU_BD
- INFO table giving bulk density values for each mapunit.
- info!STDLAYER
- Table defining the 11 standard soil layers for which the mean bulk
density was computed.
Last change: 2006 Apr 14,
R. A. White / raw@essc.psu.edu
Methodws |
Datasets |
Image
STATSGO Mapunits |
Soil Texture Class |
Depth to Bedrock
Sand, Silt, Clay Fractions |
Rock Fragment Class |
Rock Fragment Volume
Bulk Density |
Porosity |
Permeability
Available Water Capacity |
pH |
Plasticity
K-Factor |
Hydrologic Soil Groups |
Curve Numbers
Background |
Methods |
Data Coverages |
Citation |
Feedback
CONUS-Soil |
STATSGO |
SSURGO
|