Section 2: 30 Cities in Historical Perspective, 1800-2000
A global sample of 30 cities, 27 of which are in the global sample of 120 cities, was created to explore long-term urban expansion and long-term changes in urban population density from 1800 until the end of the twentieth century. The selection of cities for historical analysis was guided by two factors: their regional distribution and the availability of historic maps depicting their built-up area at 20 or 25 year intervals. 3 cities - Jeddah, Nairobi, and Lagos - were added to this sample to ensured a balanced sub-regional distribution of cities. The distribution of the cities in this sample among the nine regions is shown in the map below.
To be included in this sample, the relevant maps of a given city needed to depict the totality of the built-up area of the metropolitan agglomeration and to have sufficiently clear landmarks to be spatially referenced to Google Earth imagery. This geo-referencing process aligns the map to the known coordinates system of Google Earth images and allows the maps to be accurately overlaid and compared. A complete set of the map references containing the original maps used to construct the composite maps for each city is given in the Resources section.
Arriving at an estimate of population density required population data in addition to built-up area data. Two publications proved invaluable to our investigation of historical urban populations (United Nations Population Division 2008; Chandler and Fox 1974). At earlier dates the correspondence between population figures and the built-up area was clear, but for later dates it became more difficult to discern whether the reported population matched the extent of the built-up area. For 1990 and 2000 we again had accurate data obtained from satellite imagery and census maps.
The maps in this section of the atlas are composite digitized maps of the built-up area in a given city in different dates. The actual built-up area of the city at each date was calculated using ArcGIS software. The population associated with each map was interpolated from available historical population data, assuming a constant population growth rate in the intervening period. A total of 261 maps were used to calculate urban extent and average population densities and their change over time in the 30 cities in the sample, an average of 8.7 maps per city approximately 19±1 years apart.
Download jpg files for the 30 historical cities here:
|City||Country||Region||Maps Page||Metric Page|
|Beijing||China||Eastern Asia & the Pacific||Download||Download|
|Buenos Aires||Argentina||Latin America & the Caribbean||Download||Download|
|Chicago||United States||Land-Rich Developed Countries||Download||Download|
|Guatemala City||Guatemala||Latin America & the Caribbean||Download||Download|
|Jeddah||Saudi Arabia||Western Asia||Download||Download|
|Johannesburg||South Africa||Sub-Saharan Africa||Download||Download|
|Kolkata||India||South & Central Asia||Download||Download|
|Kuwait City||Kuwait||Western Asia||Download||Download|
|London||United Kingdom||Europe & Japan||Download||Download|
|Los Angeles||United States||Land-Rich Developed Countries||Download||Download|
|Mexico City||Mexico||Latin America & the Caribbean||Download||Download|
|Moscow||Russian Federation||Europe & Japan||Download||Download|
|Mumbai||India||South and Central Asia||Download||Download|
|Paris||France||Europe & Japan||Download||Download|
|Santiago||Chile||Latin America & the Caribbean||Download||Download|
|Sao Paulo||Chile||Latin America & the Caribbean||Download||Download|
|Shanghai||China||Eastern Asia & the Pacific||Download||Download|
|Sydney||Australia||Land-Rich Developed Countries||Download||Download|
|Teheran||Iran||South and Central Asia||Download||Download|
|Tel Aviv||Israel||Western Asia||Download||Download|
|Tokyo||Japan||Europe & Japan||Download||Download|
|Warsaw||Poland||Europe & Japan||Download||Download|