Ability to extrapolate the Barcelona solutions 291Each of the Barcelona Region pieces outlined in Chapter 10 is therefore
placed in one of three categories: (1) solutions widely applicable to urban regions
worldwide; (2) solutions widely applicable to certain sets of urban regions; and
(3) solutions limited in applicability to the distinctive Barcelona Region.
Solutions widely applicable to urban regions worldwide
Twelve results from the Barcelona analysis (see Chapter 10 and Color
Figures2--39)fall readily into this category. These solutions seem applicable to
most large and small cities irrespective of geography, land use, and culture:
The emerald networkas the backbone of natural systems applies well in
virtually all urban regions. Where the matrix is natural vege-
tation (Iquitos, Tehran), the emerald network represents a spa-
tial framework of priority areas to protect as urbanization and
other land changes proceed over time. Where the matrix is
cultivation (London, Chicago), the spatial framework indicates
priority areas for restoration of natural systems. If emeralds
are presently distributed across the urban-region ring, e.g., due
especially to topography and geology (Barcelona), their enhance-
ment, connection, and protection is the challenge.
Five typesofconnections provide flexibility for connecting the large
natural-area emeralds, a useful approach for the usual urban
region with numerous built areas. Diverse connection types
that provide connectivity across the land for both trail walk-
ers and wildlife are especially valuable in the face of ongoing
urbanization.
Agriculture--nature parksare mainly established on aggregations of small
farms, which exist in almost all urban regions (partially illus-
trated in parts of Switzerland and Germany [Pegel 2007]). A
set of protected agriculture--nature parks would be particularly
valuable where the urban-region ring is small, or the matrix has
been relatively monotonized by extensive agriculture (Chicago,
London, Bangkok).
Wat er-supply protection using vegetation coverapplies widely, e.g., where the
watersource is aquifer, shallow groundwater, lake, reservoir,
river, or stream. To provide relatively clean riverwater, strategic
areas and stretches are targeted for natural vegetation, since
covering an entire river basin with vegetation is often difficult
in an urban region. The vegetation-cover solution is least appli-
cable to a large deep aquifer or a very large lake.