Usage

Requirements

• unzip v6.0.
• PostgreSQL / PostGIS
• Python3

Setup env

$ virtualenv -p python3 env
$ pip install -r requirements.txt

Download & unzip boundaries and observations

$ python cli.py download
$ python cli.py unzip

Prepare observations

    $ python cli.py prepare \
      filename=data/2016/dissemination_areas/98-401-X2016044_English_TAB_data.csv \
      > data/2016/dissemination_areas/census_observations.csv

Dissemination areas took around 5mins to prepare on a 2.5Ghz CPU.

Load into postgres

    $ psql -c "CREATE DATABASE geo;"

    $ psql geo < sql/create_table.sql

    $ psql geo -c "\copy census_observations \
    FROM data/2016/dissemination_areas/census_observations.csv \
    CSV DELIMITER E'\t' NULL as 'null'"

    $ psql geo -c "CREATE EXTENSION postgis"

    $ ogr2ogr -f "PostgreSQL" PG:"dbname=geo" \
    -overwrite \
    -nlt MULTIPOLYGON \
    -nln census_lda \
    -t_srs EPSG:4326 \
    -progress \
    data/2016/dissemination_areas/lda_000b16a_e.shp

Optional: Build a headings table

Do you want the headings and sub-headings of each census observation as a result of a query? Carry out the following to build such a join table:

    $ psql geo < sql/create_headings_table.sql

    $ psql geo -c "\copy dim_headings \
    FROM data/2016/archives/dim_titles.tsv \
    CSV DELIMITER E'\t' NULL as 'null'"

Example

Top individual income by DA

SELECT o.geo_id, o.value_total, g.prname FROM census_observations o, census_lda g
  WHERE g.dauid = o.geo_id
  AND dim=727
  AND value_total is not null
  ORDER BY value_total
  DESC LIMIT 10;

Result:

    geo_id  | value_total | prname
  ----------+-------------+---------
   35202898 |      598016 | Ontario
   48060591 |      519168 | Alberta
   35204279 |      490496 | Ontario
   48060566 |      474112 | Alberta
   35202777 |      468992 | Ontario
   35204262 |      431104 | Ontario
   35202897 |      431104 | Ontario
   35202351 |      423936 | Ontario
   35240203 |      422912 | Ontario
   35202349 |      410624 | Ontario

Get individual income by lat lon

SELECT o.value_total FROM census_observations o, census_lda g
    WHERE ST_Intersects(wkb_geometry, ST_PointFromText('Point(-79.4105825 43.6960938)', 4326))
    AND o.geo_id = g.dauid AND o.dim = 727;

Result:

 value_total
-------------
      598016

Interpolate with custom polygon

If you want to get the observations for other boundaries than the one provided by Census Canada (Province, Forward Station Area, Municipality, ...), you have to interpolate your polygon with the DA (dissemination area). Here is an example:

• vendor contain the electoral districts for the Province of Quebec.
• I use sum because it's an absolute value (population count), if it's an average I guess you should use avg

SELECT vendor.wkb_geometry,
sum(obs.value_total * st_area(st_intersection(vendor.wkb_geometry, census.wkb_geometry))/st_area(census.wkb_geometry))::numeric::integer as total,
sum(obs.value_male * st_area(st_intersection(vendor.wkb_geometry, census.wkb_geometry))/st_area(census.wkb_geometry))::numeric::integer as male,
sum(obs.value_female * st_area(st_intersection(vendor.wkb_geometry, census.wkb_geometry))/st_area(census.wkb_geometry))::numeric::integer as female
FROM electoral_district vendor
JOIN census_lda census ON st_intersects(vendor.wkb_geometry, census.wkb_geometry)
JOIN census_observations obs ON census.dauid = obs.geo_id
WHERE ST_IsValid(census.wkb_geometry) 
AND obs.dim = 8
GROUP BY 1,2,3,4,5;

Flatten observations

  CREATE TABLE census_observations_flat as 
    SELECT level, geo_id, 
      array_agg(value_total ORDER BY dim) as value_total, 
      array_agg(value_male ORDER BY dim) as value_male, 
      array_agg(value_female ORDER BY dim) as value_female 
    FROM census_observations group by level, geo_id;

You can now query multiple observations at the same time:

  SELECT 
    obs.value_total[1698] as pop_count, 
    obs.value_total[1699] as l1_no,
    obs.value_total[1700] as l2_sec,
    obs.value_total[1701] as l3_post
  FROM census_observations obs
  WHERE geo_id = '01';

URLs

Observations (2016)

http://www12.statcan.gc.ca/census-recensement/2016/dp-pd/prof/details/download-telecharger/comp/page_dl-tc.cfm

Observations (Previous)

http://www12.statcan.gc.ca/census-recensement/pc-eng.cfm

Observations (All)

http://www12.statcan.gc.ca/datasets/index-eng.cfm

Boundaries

http://www12.statcan.gc.ca/census-recensement/2011/geo/bound-limit/bound-limit-eng.cfm

Census Observations Fields

 index description
 0     "CENSUS_YEAR"
 1     "GEO_CODE (POR)"
 2     "GEO_LEVEL"
 3     "GEO_NAME"
 4     "GNR"
 5     "DATA_QUALITY_FLAG"
 6     "CSD_TYPE_NAME"
 7     "ALT_GEO_CODE"
 8     "DIM: Profile of Dissemination Areas (832)"
 9     "Member ID: Profile of Dissemination Areas (832)"
 10    "Notes: Profile of Dissemination Areas (832)"
 11    "Dim: Sex (3): Member ID: [1]: Total - Sex"
 12    "Dim: Sex (3): Member ID: [2]: Male"
 13    "Dim: Sex (3): Member ID: [3]: Female"