The issue of under-bounding and over-bounding of cities was investigated.
Over-bounding and under-bounding was investigated by comparing the
population density of the 13 cities chosen for comparison. This information is displayed in Table 6, overleaf.
Table 6: Population of UK Cities, ordered by population density
City Population (2001
Census)
Area (km2) Density (persons/
km2)
Liverpool 439,444 112 3929
Leicester 279,887 73 3817
Birmingham 977,063 268 3649
Bristol 380,641 110 3460
Manchester 392,827 116 3397
Glasgow 577,869 176 3293
Coventry 300,851 99 3050
Newcastle upon Tyne
242,388 99 2437
Sunderland 280,773 137 2043
Edinburgh 448,624 264 1701
Sheffield 513,242 368 1395
Leeds 715,421 552 1297
Bradford 467,649 366 1276
Table 6 indicates that over-bounding and under-bounding of cities does exist in the UK. Examples of each can be made from the cases of Bradford and Liverpool
respectively. These cities had near equal populations in 2001, yet the
administrative area of Bradford City Council was more than three times the size of the Liverpool City area. A satellite image of the Bradford area (Figure 23) reveals that the city’s boundary encloses quite a large rural component: the urban portion of this Unitary Authority occupies only the lower right portion of the administrative area as it appears in the figure. Meanwhile, a similar map of the Liverpool area (Figure 24) shows that the heavily urbanised Liverpool
administrative area is continuous with the urban areas of the neighbouring local authorities of Sefton and Knowsley. These maps were created using Google Earth software. This application, which is free to use for all non-profit purposes, is a ‘virtual’ globe composed of several million satellite and aerial photographs and allows the user to zoom in on individual houses and cars or take an overview of a particular country or region.
The difference in urban/rural composition of these cities makes comparisons of deprivation and health outcome problematic since different social factors operate in rural areas than in urban areas and also because rural areas tend to enjoy better population health than urban areas. In addition, while Bradford’s boundary encloses all of that city’s suburbs, one cannot rule out the possibility that suburbs of Liverpool (be they affluent or deprived) actually lie in
neighbouring local authority areas. Therefore, it was necessary to create other definitions of UK cities that encompassed greater areas than their eponymous administrative units to allow fairer comparisons of deprivation and health outcome.
Figure 23: Aerial map of Bradford City Council Area
Figure 24: Aerial map of Liverpool City Council area
Deciding what areas to include in addition to the administrative boundaries of UK cities in order to make further comparisons of urban population health outcomes formed the basis of the next task. When describing under-bounding and over-bounding, Cheshire243wrote about the importance of understanding the
‘functional reach’ of cities rather than simply making comparisons on the basis of their administrative boundaries. A recent analysis of Scotland’s cities
published by the Scottish Executive206 explored this theme. In that analysis, several definitions of the 6 most populous cities in Scotland were discussed. By order of Census-measured population size, these were; Glasgow, Edinburgh, Aberdeen, Dundee, Stirling and Inverness. The definitions included continuously built up areas, 30 minute travel to work areas, 60 minute travel to work areas, and travel to shop or leisure areas. This paper highlighted the importance of transport corridors to the functional reach of Scottish Cities. For example, the M8 and M74 motorways and the Strathclyde Rail Network were fundamental in creating a very large 60 minute travel to work area for Glasgow City; this area encompassed most of West Central Scotland, Stirling and parts of the City of
Edinburgh, thereby defining Edinburgh and Stirling as suburb of Glasgow.
Clearly, applying such a definition as the standard way for creating functional city boundaries would not be worthwhile since similarly defined boundaries of many UK cities (not just Glasgow, Edinburgh and Stirling) would overlap with each other.
From the point of view of creating a standardised set of city boundaries, all of the definitions provided in the Executive’s report were problematic. Each
definition only reflected a single functional aspect of cities; retail, employment, leisure opportunities, education and so on. The report did not have the explicit aim of creating a single standardised set of boundaries for Scottish cities and instead described how the cities are used by the Scottish population and the multi-dimensional influence they have over the rest of the country. As a result, the definitions provided by this report were not used for two main reasons.
First, the report only discussed the various functional boundaries of Scottish cities and did not mention English cities. Second, and most importantly, none of the boundaries described could easily be matched with the level of geography for which secondary data had been made available.
7.1.3.1 Population and demographics of cities and conurbations
Three population datasets were obtained from NHS Scotland’s Information Services Division. Each of these contained the population of each ward and postcode sector in Scotland, England and Wales as measured at the Census.
Population data was broken down into 9 age groups for each sex. All
demographic analyses were performed using Microsoft Excel software or SPSS (version 14.0)
Using a coding key for the six digit identifiers (also obtained from ISD) for all of the small areas, it was possible to calculate the total population of each of the thirteen UK cities chosen for comparative analysis. A new variable entitled
‘city’ was generated within each spreadsheet. This was a categorical variable where individual postcode Sectors and wards were assigned a particular value based upon the city in which they were located. For example, all postcode Sectors within Glasgow were assigned a value of ‘1’ in the city variable; those wards within Manchester were given a value of ‘2’ and so on. Those postcode
sectors and wards that were located outwith the 13 cities were assigned a value of ‘0’ in the city variable. The total population of each city was then calculated in a simple manner by summing the population of each city’s wards or postcode Sectors. The total population of each city was calculated for 1981, 1991 and 2001