Definition
GEOALT_TZ1991 indicates the region of Tanzania where the respondent was interviewed. DHS units in GEOALT_TZ1991 are equivalent to regions.
Other sample years have their own sample-specific geography variables. There are also integrated variables GEO_TZ1991_2015 and GEO_TZ1996_2015, that provide spatially consistent units over time. Lesser geographic detail for the Tanzania 1991 sample can be found in GEO_TZ1991.
A GIS map for GEO_TZ1991 (in shapefile format) can be downloaded from the DHS Program Spatial Data Repository [URL omitted from DDI.] Boundaries page.