Urban Regions : Ecology and Planning Beyond the City

Big-ideas, governance, megacities, sense of place 339

Figure 12.3Beloved dragons and ball in Beijing’s ‘‘Forbidden City”, the actual,

symbolic, and cultural center for the people of a megacity. An unusual case, Beijing

municipal government governs essentially the entire 100 km (65 mi) radius urban

region (Color Figure 7). Two of the nine dragons on a brightly colored ceramic

courtyard wall. R. Forman photo.

general. Thus any city may have a strong cultural heritage (Figure12.3), depend
on radial highways, have wetlands largely eliminated, or be in a disaster-prone
area (Manila, Dhaka, Mexico City) (Steedman 1995).
However someattributes characterize megacitiesand seem to be important in
almost all of them (Ezcurra and Mazari-Hiriart1996,McMichael2000,ElAraby
2002).An extensive impermeable surface across the metropolitan area produces
several major effects. The heat-island effect results in high temperatures, espe-
cially in summer (Chapter4)(vonStulpnagelet al.1990,Ichinoseet al.1999,
Arnfield 2003). Heat accentuates certain air pollutants and their effects. The
hard-surface area increases flooding, and the so-called 100 year flood may return
quite often. With reduced water recharge into the ground, the water table drops
over a large area, and soil subsidence under buildings and streets commonly
occurs, sometimes quickly. Groundwater is contaminated under and around
themassive impermeable surface area. Surface water quality is degraded over a
major portion of an urban region (Renet al.2003).