SAFARI 2000 Wetlands Data Set, 1-Deg (Matthews and Fung)
----------------------------------------------

Abstract
--------

This data base, compiled by Matthews and Fung (1987), provides information on the
distribution and environmental characteristics of natural wetlands. The data
base was developed to evaluate the role of wetlands in the annual emission of
methane from terrestrial sources. The original data consists of five global 1
degreelatitude by 1 degree longitude arrays. The subset retains all five arrays
at the 1degree resolution but only for the area of interest. The arrays are: (1)
wetland datasource, (2) wetland type, (3) fractional inundation, (4) vegetation
type, and (5) soil type.

The data base is the result of the integration of three independent
digital sources: (1) vegetation classified according to the United Nations
Educational Scientific and Cultural Organization (UNESCO) system [Matthews, 1983],
(2) soil properties from the Food and Agriculture Organization (FAO) soil maps
[Zobler, 1986], and (3) fractional inundation in each 1 degree cell compiled from
a global map survey of Operational Navigation Charts (ONC). With vegetation,
soil and inundation characteristics of each wetland site identified, the data
base has been used for a coherent and systematic estimate of methane emission from
wetlands and for an analysis of the causes for uncertainties in the emission estimate. 

The global data base is available from a number of sources including:
    NASA/GISS -- http://www.giss.nasa.gov/ [Internet Link]
    NCAR, data set ds765.5 -- http://www.ncar.ucar.edu/ [Internet Link]
    ORNL DAAC -- http://www.daac.ornl.gov/ [Internet Link]

=========================================================================

Background Information
----------------------

Investigators:
Elaine Matthews
ematthews@giss.nasa.gov 

Inez Fung
ifung@uclink4.berkeley.edu 

Project: SAFARI 2000
Data Set Title: SAFARI 2000 Wetlands Data Set, 1-Deg (Matthews and Fung)

Site: Southern Africa
Westernmost Longitude: 5
Easternmost Longitude: 60
Northernmost Latitude: 5
Southernmost Latitude: -35
Start_Date: 1971-01-01
End_Date: 1981-02-28 

Data Set Citation:
Matthews, Elaine, and Inez Fung. 2002. SAFARI 2000 Wetlands Data Set, 1-Deg 
(Matthews and Fung). Available on-line [http://www.daac.ornl.gov/] from Oak
Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, 
Tennessee, U.S.A. 


Southern African subset extractions of this data were performed by Oak Ridge
National Laboratory:

    ORNL DAAC User Services Office
    ornldaac@ornl.gov
    +1 (865) 241-3952

Data Set Link: ftp://ncardata.ucar.edu/datasets/ds765.5/
Data Set Link: http://www.giss.nasa.gov/data/landuse/

=========================================================================

Data File Information
---------------------

This data set consists of 5 separate ASCII data files, each one with an
accompanying binary image file: 

  gisswet_file1.dat --> Wetland data soure
  gisswet_file2.dat --> Wetland type
  gisswet_file3.dat --> Fractional inundation
  gisswet_file4.dat --> Vegetation type
  gisswet_file5.dat --> Soil type

=========================================================================

ASCII File Information
----------------------

The data files are in ASCII Grid format for ArcInfo. Each file contains a
single ASCII array with integer values. Coordinates listed below are in decimal
degrees.

  Rows 40
  Columns 55
  UpLeftX 5
  UpLeftY 5
  LoRightX 60
  LoRightY -35
  cellsize 1
  Projection geographic 

The ASCII file consists of header information containing a set of keywords,
followed by cell values in row-major order. The file format is:

  {NCOLS xxx}
  {NROWS xxx}
  {XLLCORNER xxx}
  {YLLCORNER xxx}
  {CELLSIZE xxx}
  {NODATA_VALUE xxx}
  row 1
  row 2
  .
  .
  .
  row n

where xxx is a number, and the keyword NODATA_VALUE is optional and defaults
to -9999. Row 1 of the data is at the top of the grid, row 2 is just under
row 1 and so on. The end of each row of data from the grid is terminated
with a carriage return in the file. 

To import this file into ArcInfo use the following command at an ARC prompt: 

    ASCIIGRID {in_ascii_file} {out_grid} {INT | FLOAT}

Arguments:
{in_ascii_file} - the ASCII file to be converted.
{out_grid} - the name of the grid to be created.
{INT | FLOAT} - the data type of the output grid.
    INT - an integer grid will be created.
    FLOAT - a floating-point grid will be created.


Binary File Information
-----------------------

Each ASCII data file has also been converted into a binary image file that
can be viewed in any standard image viewing package. The files are single-byte
images, no header, 55 columns by 40 rows. Missing data (ASCII -9999) and
-1's have been converted to the maximum value of 255. 

=========================================================================

Procedure Used to Create the Southern Africa Subset
---------------------------------------------------

The original data were downloaded from NCAR (ftp://ncardata.ucar.edu/datasets/ds765.5/)
and imported into ArcInfo using the ASCIIGRID
command. 

Using GRID (a raster- or cell-based geoprocessing toolbox that is integrated
with ArcInfo) the SETWINDOW command was used to define the subarea of
interest. This subarea was defined by identifying the bounding coordinates
as follows: 

    x_min 5     y_min -35     x_max 60     y_max 5

The "snap_grid" option of the SETWINDOW command was used. This snaps the
lower- left corner of the specified window to the lower-left corner of the
nearest cell in the snap_grid and snaps the upper-right corner of the specified
window to the upper-right corner of the nearest cell in the snap_grid. In this case
the snap_grid is an original data grid. The purpose of this is to ensure the
proper registration of the newly set analysis window. The command format used is as
follows: 

    SETWINDOW x_min y_min x_max y_max original_grid

Once the window was set, creating the new grid was simply a matter of setting
the new subset grid equal to the original grid. 

    subset_grid = original_grid

An ASCII array was created from the new subset grid using the GRID command
GRIDASCII. 

    file.dat = GRIDASCII(subset_grid)

=========================================================================

Legend & Additional Sources of Information
------------------------------------------

The following legends are used in the original data:

***************************gisswet_file1.dat****************************
Data Sources for Wetland Locations

1: UNESCO + FAO + ONC(Operation Navigation Charts)
2: UNESCO + ONC
3: UNESCO + FAO
4: UNESCO
5: ONC + FAO
6: ONC
7: FAO
0: Other (non-wet) land
-1: Water

***************************gisswet_file2.dat****************************
Wetland Types

1: Forested bog
2: Nonforested bog
3: Forested swamp
4: Nonforested swamp
5: Alluvial formations
6: Tropical/subtropical forest/woodland
7: Temperate forest/woodland
8: High-latitude temperate/boreal forest/woodland/shrub
9: Shrubland; xeromorphic formations; desert
10: Wooded grassland
11: Nonwooded grassland
12: Tundra
0: Other (non-wet) land
-1: Water

***************************gisswet_file3.dat****************************
Fractional inundation (percent)

1-100: wetland
0: Other (non-wet) land
-1: Water

***************************gisswet_file4.dat****************************
Vegetation type - Due to the number of items in the legend for the global data 
set, only those represented in the southern Africa subset are listed below.  For 
the complete legend please see the original documentation.

-1: Water
0: Other (non-wet) land
1: Tropical evergreen rainforest
3: Tropical evergreen rainforest: submontane
8: Tropical evergreen rainforest: alluvial: frequently flooded
13: Tropical/subtropical evergreen seasonal forest
18: Tropical/subtropical semi-deciduous forest
24: Mangrove forest
40: Tropical/subtropical drought-deciduous forest
61: Extremely xeromorphic thorn forest: deciduous
63: Evergreen broadleaved woodland
70: Tropical/subtropical drought-deciduous woodland
71: Tropical/subtropical drought-deciduous woodland: lowland/submontane, 
    broadleaved
90: Drought-deciduous shrubland without evergreens
96: Extremely xeromorphic subdesert shrubland
102: Extremely xeromorphic evergreen subdesert shrubland: semi-deciduous
131: Tall grassland without woody cover: tropical grassland
133: Tall grassland without woody cover: tropical wetland: wet or flooded most 
     of the year
134: Medium grassland with 10-40% tree cover
139: Medium grassland with <10% tree cover
140: Medium grassland with shrub cover
145: Medium grassland without woody cover: mainly sod grasses
157: Short grassland with shrub cover
160: Short grassland with shrub cover: with deciduous thorny shrub cover
165: Short grassland without woody cover
175: Low forb communities (<1m)


***************************gisswet_file5.dat****************************
FAO Soil Types of Wetland Locations - Due to the number of items in the legend 
for the global data set, only those represented in the southern Africa subset 
are listed below.  For the complete legend please see the original 
documentation.

-1: Water
0: Other (non-wet) land
1: Ferric Acrisol
6: Chromic Cambisol
9: Ferralic Cambisol
25: Orthic Ferralsol
26: Plinthic Ferralsol
27: Rhodic Ferralsol
28: Xanthic Ferralsol
30: Dystric Gleysol
31: Eutric Gleysol
32: Humic Gleysol
40: Lithosol
41: Calcaric Fluvisol
42: Dystric Fluvisol
43: Eutric Fluvisol
44: Thionic Fluvisol
49: Chromic Luvisol
50: Ferric Luvisol
58: Dystric Nitosol
59: Eutric Nitosol
60: Humic Nitosol
62: Eutric Histosol
66: Humic Podzol
70: Albic Arenosol
71: Cambic Arenosol
72: Ferralic Arenosol
73: Luvic Arenosol
74: Calcaric Regosol
82: Mollic Andosol
86: Chromic Vertisol
87: Pellic Vertisol
89: Eutric Planosol
94: Haplic Yermosol
98: Haplic Yermosol
105: Orthic Solonchak

=========================================================================

References
----------

Matthews, E. 1983. Global vegetation and land use: new high-resolution data
bases for climate studies. J. Clim. Appl. Meteorol., 22, 474-487. 

Matthews, E. 1989. Global Data Bases on Distribution, Characteristics and
Methane Emission of Natural Wetlands: Documentation of Archived Data Tape.
NASA TM-4153. National Aeronautics and Space Administration. Washington, D.C.. 

Matthews, E. and I. Fung. 1987. Methane emissions from natural wetlands:
global distribution, area and environmental characteristics of sources. Global
Biogeochemical Cycles, 1, 61-86. 

Zobler, L. 1986. A world soil file for global climate modeling. NASA
Technical Memorandum 87802. 

-------------------------------------------------------------------
ORIGINAL DATA SET CITATION
-------------------------------------------------------------------
Matthews, E. 1989. Global Data Bases on Distribution, Characteristics and 
Methane Emission of Natural Wetlands: Documentation of Archived Data Tape. NASA 
TM-4153. National Aeronautics and Space Administration. Washington, D.C..  Data 
available on-line at: ftp://ncardata.ucar.edu/datasets/ds765.5/