This data set provides gridded data for selected soil parameters derived from data and methods developed by the Global Soil Data Task, an international collaborative project with the objective of making accurate and appropriate data relating to soil properties accessible to the global change research community. The task was coordinated by the International Geosphere-Biosphere Programme (IGBP-DIS). The data in this data set were produced by the International Satellite Land-Surface Climatology Project, Initiative II (ISLSCP II) staff from data obtained from the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC, http://daac.ornl.gov/). See the related data sets section below. Two-dimensional gridded maps of selected soil parameters, including soil texture, at a 1.0 by 1.0 degree spatial resolution and for two soil depths are provided. All data layers have been adjusted to match the ISLSCP II land/water mask. There are 36 data files with this data set.
This data set is one of the products of the International Satellite Land-Surface Climatology Project, Initiative II (ISLSCP II) data collection which contains 50 global time series data sets for the ten-year period 1986 to 1995. A complete description of the data, it's derivation, acknowledgements, and references provided by the ISLSCP II Data Management Staff is included with this data set as a companion file named 1_islscp2_soils_doc.pdf.
ISLSCP II is a consistent collection of data sets that were compiled from existing data sources and algorithms, and were designed to satisfy the needs of modelers and investigators of the global carbon, water and energy cycle. The data were acquired from a number of U.S. and international agencies, universities, and institutions. The data and documentation have undergone two peer reviews.
ISLSCP is one of several projects of Global Energy and Water Cycle Experiment (GEWEX) [http://www.gewex.org/] and has the lead role in addressing land-atmosphere interactions -- process modeling, data retrieval algorithms, field experiment design and execution, and the development of global data sets.
Related Data Sets:
Cite this data set as follows:
Scholes, R. J., and E. Brown de Colstoun. 2011. ISLSCP II Global Gridded Soil Characteristics. In Hall, Forrest G., G. Collatz, B. Meeson, S. Los, E. Brown de Colstoun, and D. Landis (eds.). ISLSCP Initiative II Collection. Data set. Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/1004
The archived data sets for ISLSCP II have been organized by categories. This data set is in the Hydrology, Soils, and Topography category---- a collection of hydroclimatology and surface elevation data sets.
Data Set Spatial Extent: Global gridded
Westernmost Longitude: -180 W
Easternmost Longitude: 180 E
Northernmost Latitude: 90 N
Southernmost Latitude: -90 S
Projection: Geographic
Data Set Spatial Resolution: 1.0 degree in both latitude and longitude
Data Set Temporal Extent: 1986 through 1995
Data File Format
All of the data files in each data set within the ISLSCP Initiative II data collection are in ASCII GRID format. The file format consists of numerical fields of varying length, which are delimited by a single space and arranged in columns and rows.
There are 36 data files with the following naming convention:
soil_parameterdepth_1d.asc Example: soil_bulk_dens0-150_1d.asc
where:
parameter is the particular soil parameter (see Section 3.2 and 8.2 for a list of parameters and descriptions).
depth is the soil depth in cm for the estimated soil parameter (i.e. 0-30 or 0-150).
1d identifies the spatial resolution of the data as 1 degree in both latitude and longitude.
.asc identifies the format of the data as ASCII, or text format.
***NOTE: The files for soil thermal capacity are named soil_therm_capWC_depth_1d.asc, where WC is the percent water content
of the soil: 0, 10, 50 or 100 percent.
Selected soil parameters investigated:
| Parameter Name | Units | Description |
|---|---|---|
| bulk_dens | g/cm3 | Bulk Density. |
| clay_perc | % w/w | % Clay Content. |
| field_cap | mm | Field Capacity (FC), with FC water potential = -10 kPa |
| ksat | cm/day | Saturated Hydraulic Conductivity or Ksat |
| nitrogen_dens | g/m2 | Soil Nitrogen Density |
| org_carb_dens | kg/m2 | Soil Carbon Density |
| org_carb_perc | % | Percent Soil Organic Carbon Content |
| pawc | mm |
Profile Available Water Content (PAWC), with: FC water potential = -10 kPa WP water potential = -1500 kPa |
| res_wat_cont | cm3/cm3 | Residual Water Content |
| sand_perc | % w/w | % Sand Content |
| sat_wat_cont | cm3/cm3 | Saturated Water Content or Porosity |
| silt_perc | % w/w | % Silt Content |
| texture | N/A | 12 Soil Texture Classes after USDA soil texture classes. |
| therm_cap | J/m3/K | Thermal Capacity, with 0, 10, 50 and 100 % volumetric soil-water fraction (i.e. four data files for each soil depth). |
| wilting_point | mm | Wilting Point (WP), with WP water potential = -1500 kPa |
Please refer to 1_islscp2_soils_doc.pdf and 0_islscp2_soils_readme.txt for a more complete description of the data files and naming conventions.
These data are available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC)[http://daac.ornl.gov].