# Data structures

Data attributes are provided for the polygons (#.PAT). These are defined as follows:

1. POLYGON DATA (#.PAT)

    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC
        1  AREA                   4    12     F      3
        5  PERIMETER              4    12     F      3
        9  F_EUR_V3#              4     5     B      -
       13  F_EUR_V3-ID            4     5     B      -
       17  ISO3                   3     3     C      -
       20  VEGN3                  3     3     I      -
       23  SOURCE_ID              6     6     C      -

AREA, PERIMETER, <coverage>#, <coverage>-id : Internal ARC/INFO attributes used to store topological structure.

ISO3: Character field attached to the polygon data indicating the ISO3 letter country code for the polygon.

VEGN3: Numeric field attached to the polygon data indicating the CIFOR forest type for the polygon (This is an updated version of vegn2 on the CIFOR CD-ROM) (See Annex 1 for classification details).

The following items can be attached from the file forest_v3.lut via the VEGN3. For further information on the forest relational model see the relationships section at the end of this section.

CIFOR_CODE: Numeric field attached to the polygon data indicating the CIFOR forest type for the polygon, same as VEGN3 except that Tropical Temperate and Other are distinguishable by the 1000, 2000, 3000 added to the vegn3 value in order to easily differentiate between Tropical, Temperate and Other.

WCFSD: Character field attached to the polygon data indicating a four category forest classification, indicating open and closed forests, used for a project done with the World Commission on Forests and Sustainable Development (WCFSD) (See Annex 4 for classification details).

LPI: Character field attached to the polygon data indicating a five category forest classification (See Annex 5 for classification details).

### 2. SOURCE INFORMATION

#### FORSOURCE

Links to arc/info polygon feature classe (coverage.pat) via the item source_code.

#### Table structure

    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC
        1  SOURCE_ID              6     6     C      -
        7  TITLE                160   160     C      -
      167  ORIGIN_ID              2     2     C      -
      169  SOURCE               254   254     C      -
      423  PUBLISHER            254   254     C      -
      677  YEAR                   4     4     I      -
      681  SCALE                 10    10     I      -
      701  OPROJECT              20    20     C      -
      721  ODATUM                10    10     C      -
      731  AUDIT                254   254     C      -

SOURCE_ID is defined as a character field, 6 characters wide. It is composed of the three letter country code from the International Standards Organisation, followed by an underscore(_) and a two digit source number. For example, given three sources for Indonesian forests the source codes would be:

    IDN_01, IDN_02, IDN_03

TITLE: Title holds the title of the data set / map / report that the information was taken from. Unpublished information may not have a title.

ORIGIN_ID two letter code that links to the FORORIGIN look-up table (see below). FORORIGIN stores the textual description of Origin_id, indicating the type of source. Values include: dye-line map, paper, remote sensing, digital data set, report.

SOURCE contains the name of the creator (editor) or creating organisation. This may differ from publisher where a published map has been drawn upon. In this case, publisher holds details on the published map, while source contains details on the source data added/drawn onto the published map.

PUBLISHER contains information for the publisher of the map or the data.

YEAR the year in which the data were published or made available to UNEP-WCMC or revised. Data revision data takes precedence over published data which takes precedence over date of delivery to UNEP-WCMC.

SCALE map scale in the form of 1: the value of the record

OPROJECT: The original projection of the source

ODATUM The original datum of the source

AUDIT: Text description of audit trail and reference to related records.

### FORORIGIN

Look up table for FORSOURCE. Holds the definition for ORIGIN_ID in the field DESC.

#### Table structure

    COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE
        1  ORIGIN_ID              2     2     C
        3  DESC                  80    80     C

## 6. RELATIONSHIPS

Relationships between the spatial data and the included attribute information are shown below. This structure is sometimes delivered as single condensed attribute tables, rather than related tables to assist those using tools with limited relational capabilities.