Global Soil Properties
(Fixed ; FAO, GISS, U. Arizona, NASA/GSFC)
Revision Date for Document: April 5, 1995

Randal D. Koster NASA/GSFC, Norman B. Bliss Principal Scientist Science and Applications Branch, Saud A. Amer ECS DAAC Scientist EROS Data Center, Soroosh Sorooshian Professor and Head Department of Hydrology and Water Resources University of Arizona

Global Soil Data Set Development and Analysis

Contacts (For Data Production Information)

              |            Contact 1             |
2.3.1 Name    |Dr. Randal D. Koster              |
2.3.2 Address |Hydrological Sciences Branch      |
              |Code 974, NASA/GSFC               |
      City/St.|Greenbelt, MD                     |
      Zip Code|20771                             |
2.3.3 Tel.    |(301) 286-7061                    |
2.3.4 Email   |      |

2.4  Requested Form of Acknowledgment. 

     The soil texture data set was constructed by Zobler (1986), and
     the soil profile depth data set was constructed by Webb et al.
     (1993).  Slope data were originally derived from the FAO Soil Map
     of the World in a 1 degree grid (GLOBTEX), version 1.0, by the
     Science and Applications Branch, EROS Data Center, Sioux Falls,
     South Dakota.  Dr. R.D. Koster performed the analyses necessary to 
     assign parameter values to the soil map texture classes.


     Hughes STX Corporation work performed under USGS contract 
     1434-92-C-40004.  Any use of trade, product, or firm names is for 
     descriptive purposes only and does not imply endorsement by the U.S. 

                              3.   Introduction

3.1  Objective/Purpose.

     Climate modelers need information on the water holding capacity of
     global soils.  The best source of this information is the Soil Map
     of the World, which was produced by the Food and Agriculture
     Organization (FAO) of the United Nations Educational, Scientific,
     and Cultural Organization (UNESCO) in 10 volumes between 1970 and
     1978.  It provides the most detailed, globally consistent soil

     Because water holding capacity is not an explicit attribute of the
     FAO soil map, the data on texture, slope, and depth that the soil
     map does provide may be used as surrogates.  The three data sets
     described herein were derived, by various researchers, from
     the FAO soil data.  For climate modelers, a 1 degree by 1 degree
     grid of latitude and longitude has been deemed adequate.

3.2  Summary of Parameters.

     Soil texture is characterized here as either coarse,
     medium/coarse, medium, fine/medium, fine, ice or organic.  Soil
     profile depth is an estimate of the depth from the soil surface to
     bedrock or other impermeable layer.  Slope is the surface slope,
     as defined by the topography.

3.3  Discussion.

     A) SOIL TEXTURE.  The soil texture data file is based on the work
     of Zobler (1986) and uses the indices listed in the table below to
     identify the texture of the dominant soil type within each 1
     degree X 1 degree grid square.  The original FAO data provided,
     for the dominant soil type in a soil unit, the designation
     "coarse", "medium", "fine", or a combination of these based on the
     relative amounts of clay, silt, and sand present in the top 30 cm
     of soil.  Zobler converted this data into a 1 degree X 1 degree

     Also listed in the table are some suggested, arbitrarily chosen
     values (see caveat) for associated soil moisture transport

   index   soil texture       n    psi_s       K_s       b  comments
   -----   ------------   -----    -----     -----   -----  --------
     1     coarse         0.421    .0363   1.41E-5    4.26  Loamy sand values*
     2     medium/coarse  0.434    .1413   5.23E-6    4.74  Sandy loam values*
     3     medium         0.439    .3548   3.38E-6    5.25  Loam values*
     4     fine/medium    0.404    .1349   4.45E-6    6.77  Sandy clay loam
     5     fine           0.465    .2630   2.45E-6    8.17  Clay loam values*
     6     ice              --       --       --       --
     7     organic        0.439    .3548   3.38E-6    5.25  Loam values*
     0     (ocean)          --       --       --       --

         n is the porosity (dimensionless),
         psi_s is the matric potential at saturation (in m)
         K_s is the saturated hydraulic conductivity (in m/s), and
         b (dimensionless) is the slope of the retention curve on a logar-
            ithmic graph, used to compute transport properties of subsaturated

     * CAUTION: The assignment of loamy sand transport parameter values
     to coarse soils does NOT imply that the "coarse" designation
     implies a loamy sand in the USDA soil texture triangle (see
     below).  Similarly, a "medium/coarse" designation does not imply a
     sandy loam, a "medium" designation does not imply a loam, and so
     on.  The mapping of transport parameter values to soil texture in
     the table is highly arbitrary and technically incorrect.  It is
     provided solely as a suggestion for the typical large scale (GCM)
     modeler, who could easily run into trouble if the "technically
     correct" numbers were used.

     The suggested reclassification in the table reflects the
     inappropriateness of assigning hydraulic properties of soils as
     measured in the laboratory to GCM soil columns that represent
     extensive areas -- they tend to produce unrealistic resistance to
     soil moisture diffusion.  This is almost certainly due to the
     inadequacy of current land surface models, which have very limited
     treatments of subgrid soil moisture variability, and to the fact
     that properties measured in the laboratory often do not describe
     soil behavior in the field, which is strongly influenced by
     spatial variability in texture, the presence of decayed root
     systems, wormholes, etc.  As a makeshift response to this problem,
     a given soil type in the table above is arbitrarily assigned
     transport parameter values for a coarser textured soil.
     Determining the optimal parameter values for each type, which are
     probably very different from those listed above, would require
     much further research.

     The values for the four transport parameters were obtained from
     the study of Cosby et al. (1984), who analyzed an extensive and
     diverse collection of soil samples.

     B) SOIL PROFILE DEPTH.  The soil profile thickness file was
     derived by Webb et al. (1991, 1993) from information contained in
     Volumes 2-10 of the FAO/UNESCO Soil Map of the World.  First, the
     Earth was divided into nine continental regions: North America,
     Mexico/Central America, South America, Europe, Africa,
     South-Central Asia, North Central Asia, Southeast Asia, and
     Australia/South Asia.  For each of these regions, the FAO records
     were examined to determine the profile thickness for a
     representative sample of every component soil type.  When a
     thickness was undefined for a soil type, an arbitrary thickness of
     3.6 meters was assigned; presumably the bedrock is at a greater
     depth than this.  All soil elements of a given type within a given
     continental region were then assumed to have the same profile
     thickness.  The thicknesses stored in the file's 1 degree X 1
     degree array are the thicknesses for the dominant soil types
     within the grid squares, as determined by Zobler (1986).

     C) AVERAGE SLOPE.  The average topographical slope for each 1
     degree X 1 degree square was derived from data sets constructed by
     the Science and Applications Branch of the EROS Data Center in
     Sioux Falls, South Dakota.  Unlike the soil texture and soil
     profile thickness data, the average slope data reflects all of the
     soil regimes in a square, not just the dominant one.  The slope
     estimates are crude, however, given the qualitative nature of the
     original data.  See Section 9.2.1 for details on the construction
     of the data set.
                        4.  Theory of Measurements

Textural classes reflect the relative proportions of clay (fraction less than 
2 micrometers), silt (2-50 micrometers), and sand (50-2,000 micrometers) in 
the soil.  The texture of a soil horizon is one of its most permanent 
characteristics.  It is also a very important one because, in combination with 
other properties, it influences soil structure, consistence, porosity, cation 
exchange capacity, permeability and water holding capacity.   

Three textural classes are recognized by the FAO Soil Map of the World:

       1.  Coarse textured:  sands, loamy sands, and sandy loams with less 
           than 18 percent clay and more than 65 percent sand.

       2.  Medium textured:  sandy loams, loams, sandy clay loams, silt loams, 
           silt, silty clay loams, and clay loams with less than 35 percent 
           clay and less than 65 percent sand; the sand fraction may be as 
           high as 82 percent if a minimum of 18 percent clay is present.

       3.  Fine textured: clays, silty clays, sandy clays, clay loams, and 
           silty clay loams with more than 35 percent clay.

The textural class refers to the texture of the upper 30 centimeters of
the soil, which is important for tillage and water retention.  The maps
often state that a dominant soil type is composed of combinations of
these textural classes (e.g., coarse AND medium for a given soil).

                                         /  \
                                      90/    \10
                                       /      \
                                    80/        \20
                                     /          \
                     / \          70/            \30
                      |            /              \
                      |         60/                \40
                      |          /       FINE       \
                Percent clay  50/                    \50  Percent silt
                               /                      \         |
                            40/                        \60      |
                             /--------------------------\       |
                          30/                            \70   \ /
                           /                              \
                        20/                                \80
                         /--------          MEDIUM          \
                      10/         \                          \10
                       /    COARSE \                          \
                     100  90  80  70  60  50  40  30  20  10   
                                     Percent sand

To obtain the soil moisture transport parameters listed in the table in
Section 3.3, points corresponding to these textures or texture
combinations were located on the U.S. Dept. of Agriculture (1951, p.
209) textural triangle, a rough reproduction of which is shown below:

                                         /  \
                                      90/    \10
                                       /      \
                                    80/        \20
                                     /          \
                     / \          70/            \30
                      |            /              \
                      |         60/       C        \40
                      |          /                 /\
                Percent clay  50/\                /  \50  Percent silt
                               /  \              / SiC\         |
                            40/ SC \____________/______\60      |
                             /______\     CL    \ SiCL  \       |
                          30/ SCL    \___________\_______\70   \ /
                           /_________/          /         \
                        20/_         \    L    /   SiL     \80
                         /  \_   SL   \       /             \
                      10/\_   \_       \_____/         ______\90
                       / S \ LS \_          /         /  Si   \
                     100  90  80  70  60  50  40  30  20  10   
                                     Percent sand

The soil textures identified in the figure are:
               C: Clay
              SC: Sandy clay
             SiC: Silty clay
             SCL: Sandy clay loam
              CL: Clay loam
            SiCL: Silty clay loam
               S: Sand
              LS: Loamy sand
              SL: Sandy loam
               L: Loam
             SiL: Silt loam
              Si: Silt

The points were then arbitrarily shifted toward coarser soils (see
Section 3.3), and transport parameters for the coarser soils were taken
from Cosby et al. (1984), who used the same triangle to differentiate
soil types.

Refer to the text published with the Soil Map of the World (FAO,
1970-78) for additional information on the methods of measurement.  See
also Zobler (1986) and Webb et al. (1991, 1993) for more background on
the data used to determine soil texture and soil profile depth.

                            5.  EQUIPMENT

5.1  Instrument Description.

     Not applicable.

     5.1.1  Platform.

            Not applicable.

     5.1.2  Mission Objectives.

            Not applicable.

     5.1.3  Key Variables.

            Not applicable.

     5.1.4  Principles of Operation.

            Not applicable.

     5.1.5  Instrument Measurement Geometry.

            Not applicable.

     5.1.6  Manufacturer of Instrument.

            Not applicable.

5.2  Calibration.

     Not applicable.

     5.2.1  Specifications.

            Not applicable.


                     Not applicable.

     5.2.2  Frequency of Calibration.

            Not applicable.

     5.2.3  Other Calibration Information.

            Not applicable.

                          6.  PROCEDURE

6.1  Data Acquisition Methods.

     The original source maps are the FAO Soil Map of the World.  The ESRI 
     digitized the data under contract to the United Nations Environment 
     Program (UNEP) and the FAO in 1984.  The EROS Data Center obtained
     the digital data from the ESRI in 1986 and constructed the data
     sets that were later used to derive the global array of average
     slope (see Section 9.2.1).

6.2  Spatial Characteristics.

     The original source map had a scale of 1:5,000,000 (1 millimeter on the 
     map = 5 kilometers).

     6.2.1  Spatial coverage.  

            The coverage is global.  Data in each file are ordered from North 
            to South and from West to East beginning at 180 degrees West and 
            90 degrees North.  Point (1,1) represents the grid cell centered 
            at 89.5 N and 179.5 W (see section 8.4).

     6.2.2  Spatial Resolution.

            The data are given in an equal-angle lat/long grid that has a 
            spatial resolution of 1 x 1 degree lat/long.

6.3  Temporal Characteristics.

     6.3.1  Temporal coverage.

            Soil survey and correlation work, primarily in the 1960's and 

     6.3.2  Temporal resolution.

            The soil map typically portrays time-invariant features.   

                             7.  OBSERVATIONS

7.1  Field Notes.

     Not applicable.  Field notes were used by the soil surveyors in 
     developing the original FAO Soil Map of the World and are reflected in 

                               8.  DATA DESCRIPTION

8.1  Table Definition.

     Not applicable.

8.2  Type of Data.

|                 8.2.1              |               |          |             |
|Parameter/Variable Name             |               |          |             |
|                    8.2.2           |     8.2.3     |  8.2.4   |  8.2.5      |
|     Parameter/Variable Description |     Range     |  Units   |  Source     |
|DOMTEX                              |               |          |             |
|    | Dominant soil texture index   |    min=0      |[Unit-    | Zobler et   |
|    |                               |    max=7      |less]*    | al. (1986)  |
|    |                               |               |          |             |
|PROFDEP                             |               |          |             |
|    |Soil profile depth             |    min=0      |   [cm]   | Webb et     |
|    |                               |    max=800    |          | al. (1993)  |
|    |                               |               |          |             |
|AVGSLOPE                            |               |          |             |
|    |Average slope                  |    min=10     |   [%]    | Manipulation|
|    |                               |    max=40     |          | of EROS DATA|
|    |                               |               |          | CENTER data |
|    |                               |               |          | files (see  |
|    |                               |               |          | sect. 9.2.1)|
* The values in the soil texture map are an index. See table in section 3.3 
  for description of each index value.

8.3  Sample Data Record. 

     See Section 8.4, Data Format.

8.4  Data Format.

     The CD-ROM file format is ASCII, and consists of numerical fields of 
     varying length, which are space delimited and arranged in columns and 
     rows.  Each column contains 180 numerical values and each row contain 360 
     numerical values.  

          Grid arrangement

             I  = 1 IS CENTERED AT 179.5W
             J  = 1 IS CENTERED AT 89.5N

             90N - | - - - | - - - | - - - | - -
                   | (1,1) | (2,1) | (3,1) |
             89N - | - - - | - - - | - - - | - -
                   | (1,2) | (2,2) | (3,2) |
             88N - | - - - | - - - | - - - | - -
                   | (1,3) | (2,3) | (3,3) |
             87N - | - - - | - - - | - - - |
                  180W   179W    178W   177W


8.5  Related Data Sets.

     Digital data for the FAO Soil Map of the World are available from the 
     Land and Water Development Division, FAO, in Rome, Italy.  The data set 
     does not include information on the components of the soil map units or 
     the slope and texture within components.  

     The EROS Data Center in Sioux Falls, South Dakota, has constructed
     global arrays containing information on the subgrid distributions
     of important soil properties.  They first divided soil texture
     into three categories (coarse, medium, and fine), soil depth into
     three categories (shallow, limited and other), and slope into
     three categories (0-8%, 8-30%, and >30%).  A given soil element is
     then described by one of 27 different combinations of texture,
     depth, and slope.  The EROS Data Center produced an array for each
     of the 27 combinations, giving the percentage of each 1 degree X 1
     degree square covered by the particular combination.

                            9.  DATA MANIPULATIONS

9.1  Formulas.

     9.1.1  Derivation techniques and algorithms.

            Arc/Info software was used for most processing steps in the
            construction of the slope data files generated by the EROS
            Data Center (which were then used to construct the average
            slopes), including projection from the bipolar oblique
            conformal projection to geographic (latitude-longitude)
            coordinates for the Americas.  The remainder of the world
            was projected from the Miller oblated stereographic
            projection using software provided by Sprinsky (1992).

9.2  Data Processing Sequence.

     9.2.1  Processing steps and data sets.

            Data processing for the soil texture and profile depth
            files are described by Zobler (1986) and Webb et al. (1991,
            1993), respectively.  The average slopes were generated by
            some simple processing of data sets produced by the EROS
            Data Center.  These data sets provide, for each 1 degree X
            1 degree square, the fractions f1, f2, and f3 of area
            covered by "level to gently undulating" (0-8%), "rolling to
            hilly" (8-30%) and "steeply dissected to mountainous"
            (>30%) slopes, respectively.  For the calculation of the
            average slope, the 0-8% slope category was assigned a
            typical slope of 4%, the 8-30% slope category was assigned
            an average slope of 19%, and the >30% slope category was
            assigned the arbitrary slope of 40%.  The average slope was
            then taken to be:

                                       f1*4% + f2*19% + f3*40%
                     average slope =  -------------------------

     9.2.2  Processing change.  

            Not applicable.

9.3  Calculations.

     9.3.1  Special corrections and adjustments.  

            See Webb et al. (1991, 1993) for a discussion of the
            decision rules they used to account for missing or
            inadequate data in the construction of the soil profile
            depth data set.

            A few of the 1 degree X 1 degree squares that were assumed
            by Zobler (1986), Webb et al. (1991, 1993), and/or the EROS
            data center to be ocean squares are in fact listed as land
            squares in the vegetation data sets provided on the CD-ROM,
            and vice-versa.  To correct this inconsistency, the soil
            data files were modified to use the same land/sea mask as
            the vegetation data files.  Missing soil data for the "new
            land squares" were estimated subjectively from neighboring
            squares.  Some of the "ice" squares in the original soil
            data sets are considered "tundra" in the vegetation data
            set; soil properties in these squares were similarly

9.4  Graphs and Plots. 

     Not applicable.

                                     10.  ERRORS

10.1  Sources of Error.

      The original FAO data represent a generalization of more detailed data, 
      which may be available in various countries, and which are in
      turn a generalized representation of reality.  As stated by
      Zobler (1986), "about 11,000 maps were reviewed [to construct the
      FAO Soil Map of the World]; they varied widely in reliability,
      detail, precision, scales, methodologies, etc."  As with any soil
      map, some of the variability in the actual soils is not shown on
      the map.  Errors may have been introduced in the digitizing and
      map projection process.

      The soil texture and profile depth files contain data for the
      dominant soil type in each 1 degree X 1 degree square and thus
      ignore contributions from potentially significant secondary
      components.  The profile depths are generally based on depths
      measured for an equivalent soil elsewhere on the continent;
      depths are not actually measured at each square.  For further
      discussion of the limitations of these data sets, see Zobler
      (1986) and Webb et al. (1991, 1993).  (The latter
      note, for example, that "in many cases, the soil profile
      thicknesses represent minimum possible values because profile
      descriptions do not always extend to subsurface bedrock".)  An
      obvious source of error in the average slope file is the
      arbitrary choice of 40% to represent all steep slopes, when all
      that is known is that they exceed 30%.  Also, for the files used
      to compute the average slopes, assumptions were made on the
      percentage composition of the components.  The vector data sets
      were gridded as separate data sets, and the data sets were merged
      in grid form.  Some overlaps between data sets were removed

10.2  Quality Assessment.

      10.2.1  Data validation by source. 

              Not applicable.

      10.2.2  Confidence level and accuracy judgment.

              Some measure of reliability was provided for the original
              FAO source maps, but these measures were not considered
              when constructing the soil texture, depth, and slope
              files, and corresponding arrays of reliability estimates
              are not available.  The accuracy of the data is, of
              course, severely limited by the errors outlined in
              Section 10.1.

      10.2.3  Measurement error for parameters and variables.  

              The published FAO Soil Map of the World contains inset
              maps showing three categories of reliability for the
              source data used to make the map.  Those interested in
              the reliability at a specific site should consult this
              source; again, digitized global reliability estimates are
              not available. Detailed soil surveys were performed only
              over selected areas of each continent.

      10.2.4  Additional quality assessment applied.  

              Not applicable.

                              11.  NOTES

11.1  Known Problems with the Data.

      The FAO Soil Map of the World is becoming out-of-date because of recent 
      soil surveys and new techniques for measurement and data handling.  An 
      international effort to develop a replacement, the Soil and Terrain 
      (SOTER) digital data base of the world, is under development by the 
      International Society of Soil Science, the International Soil Reference 
      and Information Center, the FAO, and the UNEP.   

11.2  Usage Guidance.

      The three soil data files are provided mainly for use in defining
      land surface properties for general circulation model (GCM)
      applications.  Many land surface models coupled to GCMs require
      estimates of soil profile depth, surface slope, and soil moisture
      transport properties (as obtained from soil texture) for their
      runoff, soil moisture storage, and drainage parameterizations.
      Inherent in the data are large-scale spatial variations in the
      soil properties, which presumably are realistic even if values at
      various grid squares are inaccurate.  This large-scale structure
      can be important for defining GCM climate.

      Given that climate modelers are the expected users of the data,
      the danger of using the data for other applications must be
      stressed.  Extracting a soil texture, slope, or soil profile
      depth from the files for a specific small-scale region (even a
      region composed of numerous 1 degree X 1 degree squares) is
      foolhardy without further research into the reliability of the
      data in the region, as determined, for example, from the original
      FAO Soil Map of the World.  At some squares, the data is
      undoubtedly unreliable.  Even if the reliability were high, soil
      texture and profile depth are provided only for the dominant soil
      component of the 1 degree X 1 degree square, and thus the
      appropriate values in a subgrid region of interest can easily be
      missed.  The moisture transport parameter values listed in the
      table in Section 3.3 are undoubtedly inaccurate and are provided
      ONLY to give climate modelers a consistent basis for performing
      intercomparison studies.

      The data can be spatially aggregated by averaging the values in 
      adjacent grid cells to create, for example, a 2x3 degree grid or a 3x5 
      degree grid.  Although the grid cells are not equal area, and large 
      errors would be introduced if a cell at the equator were averaged with 
      a cell at the north pole, the errors from averaging adjacent cells will 
      be within the accuracy limits for the data set.   

11.3  Other Relevant Information.

      Not applicable.

                             12.  REFERENCES

12.1  Data Processing Documentation.  

      Not applicable.

12.2  Journal Articles and Study Reports.

      Cosby, B.J., G.M. Hornberger, R.B. Clapp, and T.R. Ginn, 1984.  A
         statistical exploration of the relationships of soil moisture
         characteristics to the physical properties of soils, Water
         Resources Research, 20:682-690.
      Food and Agriculture Organization (FAO) of the United Nations, 1970-78, 
         Soil map of the world, scale 1:5,000,000, volumes I- X: United 
         Nations Educational, Scientific, and Cultural Organization, Paris.   
      Sprinsky, William H., 1992. The inverse solution for the Miller oblated 
         stereographic projection:  Presented at the 27th International 
         Geographical Congress, Washington, D.C.   
      U.S. Dept. of Agriculture, 1951.  Soil Survey Manual.  U.S. Dept. of 
         Agriculture Agricultural Handbook, 18, 503pp.
      Webb, R.S., C.E. Rosenzweig, and E.R. Levine, 1991.  A global
         data set of soil particle size properties, NASA Tech. Memo. 4286,
         NASA, 34pp.
      Webb, R.S., C.E. Rosenzweig, and E.R. Levine, 1993.  Specifying
         land surface characteristics in general circulation models: soil
         profile data set and derived water-holding capacities, Global
         Biogeochemical Cycles, 7:97-108.
      Zobler, L., 1986.  A world soil file for global climate modeling.  NASA 
         Tech. Memo. 87802, NASA, 33pp.
      Zobler, Leonard, 1987.  A world soil hydrology file for global climate 
         modeling: International Geographic Information Systems Symposium: 
         The Research Agenda, November 15-18, 1987, Arlington, Virginia, 
         Proceedings. 1:229-244. 

12.3 Archive/DBMS Usage Documentation.

      Contact the EOS Distributed Active Archive Center (DAAC) at NASA Goddard 
      Space Flight Center (GSFC), Greenbelt Maryland (see Section 13 below).
      Documentation about using the archive or information about access to the 
      on-line information system is available through the GSFC DAAC User 
      Services Office.

                             13.  DATA ACCESS

13.1  Contacts for Archive/Data Access Information.

      GSFC DAAC User Services
      NASA/Goddard Space Flight Center
      Code 902.2
      Greenbelt, MD 20771

      Phone:     (301) 286-3209
      Fax:       (301) 286-1775

13.2  Archive Identification.

      Goddard Distributed Active Archive Center
      NASA Goddard Space Flight Center
      Code 902.2
      Greenbelt, MD 20771

      Telephone:  (301) 286-3209
      FAX:        (301) 286-1775

13.3  Procedures for Obtaining Data.

      Users may place requests by accessing the on-line system, by sending 
      letters, electronic mail, FAX, telephone, or personal visit.

      Accessing the GSFC DAAC Online System:

      The GSFC DAAC Information Management System (IMS) allows users to 
      ordering data sets stored on-line.  The system is open to the public.

      Access Instructions:

      Node name:
      Node number:
      Login example: telnet
      Username:  daacims
      password:  gsfcdaac

      You will be asked to register your name and address during your first

      Ordering CD-ROMs:

      To order CD-ROMs (available through the Goddard DAAC) users should 
      contact the Goddard DAAC User Support Office (see section 13.2).

13.4  GSFC DAAC Status/Plans.

      The ISLSCP Initiative I CD-ROM is available from the Goddard DAAC.


14.1  Tape Products.  


14.2  Film Products.  


14.3  Other Products.

      There are several ways in which these data can be made available to 
      users.  One alternative assigns a unique identifier to each one degree 
      cell and uses a relational data base management system to keep track of 
      all of the attribute information.  This format is appropriate for 
      researchers with a geographic information system that is linked to a 
      relational data base management system, especially if additional 
      interpretations are needed of the 106 FAO soil types.   

                              15.  GLOSSARY OF ACRONYMS

CD-ROM           Compact Disk--Read Only Memory
DAAC             Distributed Active Archive Center
DBMS             Data Base Management System
ECS              EOS-DIS Core System
EOS              Earth Observing System
EOS-DIS          EOS Data and Information System
EROS             Earth Resources Observation Systems
ESRI             Environmental Systems Research Institute, Inc.
FAO              Food and Agriculture Organization of the United Nations
FTS              Data set name prefix: Fao soil type, Texture, and Slope
GCM              General Circulation Model of the atmosphere
GLOBTEX          GLOBal soil TEXture and slope data set
GSFC             Goddard Space Flight Center
IDS              Inter disciplinary Science
ISLSCP           International Satellite Land Surface Climotology Project
NASA             National Aeronautics and Space Administration
SOTER            SOil and TERrain digital data base of the world
UNEP             United Nations Environment Program
UNESCO           United Nations Educational, Scientific, and Cultural