Friday, July 24, 2015

1971 CSD Boundary Files


Does anyone know where I might find CSD boundaries for the 1971 census? There’s an attribute table on the EFT, but the researcher who’s asking doesn’t think he can convert it to a shapefile. 
If CSD boundary files aren’t available, the researcher says CD boundaries will suffice, if anyone has those.


I consulted subject matter and they don’t have any other files available for this.

There is a SPSS program that converts files from ASCII to SPSS – if you run it, you’ll have an SPSS file that you can save as a dBase file which includes UTM and Lambert Coordinates, which should be able to be mapped within GIS. However, it’s not a boundary file. I surmised that since there is only one record per Enumeration Area, the file records the centroid of the enumeration area (rather than the boundaries). Looking at geog-attrib-file-71-guide.pdf confirmed that (page 13). So I’m not sure it will do what the researcher wants.

Unfortunately there’s not enough information in the attributes file to produce polygons, which is what the research really wants. Still, I’ll let him know that this is available. It may be as close as he’s going to get.

A few months ago I converted the 1971 gtf71.txt file and the embedded UTM coordinates to a .shp file with lat/long. While it is not a boundary file, each point represents the population weighted centre of each EA along with a population count in the attribute table.

Or as stated in the related PDF guide: for each EA the geocoding programme has chosen a point (centroid) situated at approximately the centre of gravity of the enumeration areas population (page 13). 

We can send these over if they interest the researcher