ANNEX  I

Cities at 300 km² (City-meter)

Introductory notes

This tentative list of cities with population bigger (larger) than 300,000 at the first 300 km of their territory is  merely an attempt to illustrate how much our perception of cities would change if we accept some such common unit for comparison among the cities, “the city meter”. It is accurate as much as the available data.

Key problem is that the data on official area changes are not as available as data for population changes. Unfortunately during the last decade it became fashionable to replace older city limits for the city proper (which were in most cases well bellow 300 km² threshold), with some larger than city area. Still worse, in a kind of creative urban accounting, population data for the larger than city units were (and still are) quite often coupled with the data on area for the city proper. Many errors of this kind were corrected but despite all the checking, some might have remained.

Generally cities that claim larger area are somewhat shortchanged because it was not always possible to estimate the most central 300 km², or the most densely populated first 300 km² (and the two do not necessarily overlap). Yet it was still more difficult to assess the total number for cities with official area smaller than 300 km². Where the data for adjacent suburbs or towns were available, population figure of such cities was inflated to include their neighbourhs in those settlements. Where such data was lacking, no attempt was made to estimate the number of those “neighbourhs”.

If the idea of city meter become accepted, in future it would be possible to give more accurate picture, a more accurate list of cities at 300 km².

Sources

Besides local, national, and supranational statistical offices (like Eurostat), particularly helpful were the city population website (city.population.de), and Wikipedia. They are providing, in many cases, the administrative breakdown of a city area into smaller units (districts, towns etc.), with tables matching the population number with the figure for the

corresponding area, as well as a map in which those areas were painted in different colours. In such cases it was easy to locate the central city districts and to add their areas until you reach the 300 km² threshold.

But in cases where such tables were not available, for the cities with official area exceeding 300km², it was only possible to divide the total population figure by the figure for official area, and to multiply it by 300, to get this population figure for the first 300km². Yet such figure is almost always considerably lower than the real one. This is particularly true in cases when almost all the population lives within 300 km², but official data quote a much larger territory. In less extreme cases, the real figure for the population at 300 km² is still underestimated because the density gradient is ignored. Thus we are getting the figure based on assumption of constant density, while it is usually considerably declining.

Of course, the closer the official area is to 300 km², the smaller such differences are, and vice versa.

In most cases the population figures are derived from census data around the year 2010. Unfortunately many countries have their censuses in different years, or didn’t have one for quite a while so the latest data (or even estimates) may be a decade old. Particular trouble was with the city which appears to be leading the list – Karachi, for which until recently there were only estimates of the population figures for the year 1998 (!), with no breakdown of territorial administrative units. Then, in a short span of time, first the estimates for the year 2006 became available, coupled with a map and a breakdown of city administrative units, and later some estimates from the 2011 census emerged. The problem is that they are indicating an immense increase, the doubling up of population within a little more than a decade, from an already high total of 7 million inhabitants.

Comments

It is interesting to mention another problem, even when maps with the breakdown of administrative units and tables with both population and area figures of such units are given. Namely, density gradient doesn’t have to fall at equal pace in all directions. So, all units within the perfect circle of city’s first 300 km² don’t have to have the same density. Those in the Inner Center usually have the highest density (including a rather small Clark’s crater due to CBD and public buildings). But those in the Wider Center may differ considerably. Thus in Moscow’s Wider Center the northern units have a considerably larger density than the southern ones, resulting in a huge difference of 800,000 inhabitants. So, the most densely populated first 300 km² for Moscow is 3,9 million, instead 3,1 million for the most central first 300 km².

Similar problem emerged in many large cities in LDC, where the most densely populated areas are those least covered by public utilities, at the periphery or even in the closest suburbs (as is the case with Mumbai).