176Built systems, built areas, and whole regions
If important resources are nearby, such as a key aquifer and an agricultural
park (Barcelona; Chapter 10 ), strategic planning for a second location, e.g., to
emphasize local/regional travel or cargo transport, is important.
[S12]Aircraft noise in the urban regions occurs in built land most, cropland next, and
natural land least(Figure7. 5).
Aircraft noise in and by built land is well known to create problems for people,
from stopping a conversation or class to physiological stress or disruption of
park recreation. Avoidance and mitigation are commonly attempted. Animals,
like people, hear and are stressed, but additionally they respond to predator--
prey interactions. Wildlife may not hear a predator and get eaten, or may go
hungry if the prey are gone, or may see a sibling get eaten and then avoid
thearea. Avoidance and mitigation are also important for nature. Cropland is
probably least affected by aircraft noise. Wildlife species there are mostly tolerant
generalists and may be common where cropland is extensive and connected.Shipping/ferry ports, airports, and development corridors
[S13]About half of the shipping/ferry ports are close to the city center, while the
other ports are evenly distributed from about 20 to 140 km distant(Figure7. 6).
Portsatadistance require transport of goods and people to and from the
city. This stimulates strip (ribbon) development, with associated disruptions of
stream/river corridors and wildlife crossing. The aquatic zone around a port is
polluted and, in addition, adjoining shoreline stretches tend to be degraded.
Portareas are also likely to be sources of non-native species, some of which may
become invasive in the region.
[S14]About one-sixth of the cities has two of the three major transportation facilities (port
and two closest airports to center city) >20 km out(Figure7. 6).
This suggests a considerable length of strip-development corridors, with nega-
tive consequences for natural systems as described above. Busy flows of truck and
car traffic continue throughout the day, unlike the typical pulses of commuter
traffic.Wildlife underpasses and overpasses
[S15]Most urban regions have busy multilane highways passing between or cut-
ting through major natural areas, where wildlife underpasses or overpasses are especially
valuable to provide connectivity for walking and wildlife movement(Color Figures2--39).
Wide underpasses and overpasses designed with vegetation for wildlife cross-
ing across major highways are widely and successfully used in Europe, and are