HISTORY.TXT -  9th of 19 digital documentation files distributed
               with the "Forest Fire Chronology of Saskatchewan"
               (FFCS) dataset.


<Document overview>

     Indicates the progression of the FFCS project since its
     inception, focusing primarily on data handling and
     documentation issues.


<Fire identifiers>

     The project started off using a four digit integer for the
     FIRE_NO identifier which was stored in the -ID field of all
     polygon attribute tables.  (E.g. 4501 representing the first
     fire in 1945).  This identifier was used with the 1945 to 1989
     coverages.  The FIRE_NO identifier has since been converted to
     an eight character field (e.g., "1945-001") that was added to
     .PAT files.

     There were three reasons for this change,  First, up to 999
     fires in a single season can now be recorded.  While it is
     unlikely that there ever will be more than 99 fires larger
     than a thousand hectares in a season (the most fires currently
     in the database is 82 for the year of 1980) it is nevertheless
     possible that more than 100 fires could occur in a single fire
     season.  The odds of experiencing more than 999 fires that are
     at least 1000 ha in size during a single season are quite
     remote.

     Second, the new numbering system permits sequential sorting
     even after fires from the year 2000 on are added to the
     database.  Third, fields containing numerical entries that
     will not be used in mathematical calculations should always be
     character based.


<Documentation>

     The initial dataset had absolutely no on-line documentation.
     A two page metadata document was then prepared, but more
     detailed documentation was still required.  Now, every
     coverage has an INFO file tied to it (*.NB) which describes
     the source of the data and points the user to the SK_READ
     database file.  In turn, the SK_READ briefly describes the
     dataset and copying policies and data limitations.  Finally,
     SK_READ refers the user to the 19 digital text files provided
     with the dataset.

     The exhaustive documentation allows users to appropriately
     apply the database in their application without having to
     contact the author for details.



<Linkage of FFCS datasets to Forest Fire Management Branch data>

     The initial 1945-1989 dataset did not indicate the numbers
     that FFMB assigned to fires.  This prohibited linking the
     spatial FFCS dataset to the FFMB attributes.  Consequently,
     digitizing of all 1990-1994 fires and some 1995 fires involved
     inclusion of the FFMB fire codes.  While these linkages have
     not yet been incorporated into the database that is
     distributed, they will be.  Likewise, pre-1990 fires that can
     be linked to FFMB databases will be retrofitted with FFMB fire
     numbers wherever these linkages can be made with reasonable
     certainty.




This document prepared by:

Ott Naelapea
Wildlife Branch
Saskatchewan Environment & Resource Management
Box 3003, 800 Central Avenue
Prince Albert, SK.  S6V 6G1
CANADA
(306)953-2671 - Tel.
(306)953-2750 - Fax.

November 28, 1996
