Whole regions 195Proportion of total border length of built area in urban regionfor different-sized communities (%)LondonBerlin+Rome+Bucharest+Stockholm+Barcelona+NantesChicago+San Diego/Tijuana+Philadelphia+Ottawa•EdmontonPortlandAtlantaMexico CitySantiagoBrasilia+TegucigalpaIquitos- Cairo
*
Nairobi+Bamako+East LondonAbecheBeijing*
MoscowSeoul*
Te h r a n*
Sapporo+UlaanbaatarErzurumKagoshimaBangkokKuala Lumpur+CuttackSamarindaCanberraRahimyar Khan•
Europe North
AmericaLatin
AmericaAfrica West-East
AsiaMMMMMM
M MMM MMMMMMM MMMMMMMMMMM M
M M M M
M
M
M
M
M MTS
S
SS
SS S
SSSS
S
S
SS
SSSSSSSS SS
S
SSS S
SSS STTTTT
TTT TTTT
T
TTT TTTTT TT
TTT
TT
TTT TT
TT
T
TTSouth Asia-
AustraliaAverageGeographic area, with cities from large to small population0
20
40
60
80
S SS S S= Metropolitan area
= Satellite cities
= TownsM
S
TFigure 7.18Proportion of built-area border length due to metropolitan area,
satellite cities, and towns relative to geography and city size. Border length of the
metro area and all inner and outer satellite cities was directly measured, while
length for towns was estimated from a representative sample. Cities and towns are
differentiated by area (see Color Figures 2--39). See Figure 7.2 caption.This emphasizes that the border length of metropolitan areas matters, and is
associated with degrading the greatest area of regional greenspace. The metro-
area border plus that of nearby cities (in the inner urban-region ring) provides
about half of the total border length for the region. Greenspace in this area tends
tobe close to the huge metro-area population, which also is likely to expand
outward.
In the outer portion of the urban region, satellite cities and towns provide
theother half of the total border length. In this area many town and small-city
governments with different perspectives, mostly local, make decisions that affect