FEWS NET organizes annual sub-national data by the set of reporting entities units which existed at the time of production, not to the current namereporting units. In order to maintain a link with the exact coordinates/locations of previous production estimates, FEWS NET maintains relationship tables of geographic units.
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The process starts in each country by preparing a list of the names and hierarchical relationships of all the sub-national reporting units at a designated 1980s start date.
Each entity is assigned a unique FEWS NET identification code (a FEWS NET “ID”, or “FNID”) which also locates them in the national-level hierarchy of reporting units (Admin 1, Admin 2, etc).
A year-by-year accounting of changes that have occurred in any of the reporting units is developed.
If a change is simply a change of name, then the reporting unit retains its same FNID.
If the reporting unit’s geographic shape or hierarchical relationship is changed (e.g., it is merged with another unit or demoted from Admin 1 to Admin 2), then its FNID is changed. When these types of changes occur, the national map of reporting units changes and FEWS NET creates a new annual set of reporting units. This new annual boundary set becomes effective as of that year. Learn more about FEWS NET’s geographic unit relationship types.
The resulting genealogy of temporal and hierarchical relationships between all reporting units is entered into the FDW.
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