Urban Systems As Place-Based Foci For Infrastructure Interactions - Climate Change and Infrastructure, Urban Systems, and Vulnerabilities - page 43

energy (including biomass-based cooking and heating fuels), these cities may become
even more vulnerable to climate change, since many sources of renewable energy are
subject to changing climate regimes.
2) WATER AND WASTEWATER
Cities consistently grapple with maintaining sufficient supplies of fresh drinking water
and managing excess water from flooding as well as handling waste water and sew-
erage flow (Major et al., 2011). Urban water and wastewater systems can come under
great stress as a result of climate change. Both the quantity and quality of the water sup-
ply will be significantly affected by the projected increases in both floods and droughts
(Aerts, et al., 2009; Case, 2008; Kirshen, et al., 2008), as climate change shortens the return
frequencies of extreme weather events. Within cities, impervious surfaces and increased
precipitation intensity can overwhelm current drainage systems. As climate continues
to change, both formal and informal urban water supply services will be highly vulner-
able to drought, extreme precipitation, and sea level rise. Moreover, air temperature in-
creases will affect temperatures of receiving waters. Long-term planning for the impacts
of climate change on the formal and informal water supply and wastewater treatment
sectors in cities is required, with plans monitored, reassessed, and revised every 5-10
years as climate science progresses and data improve (Major et al., 2011).
Several significant adaptation and mitigation strategies - often with co-benefits - are
available for the water and wastewater sector which make these systems more resilient
in the face of increased supply and function stress (Kirshen et al., 2008; Nelson et al.,
2009). In regard to immediate adaptation strategies, programs for effective leak detec-
tion and repair and the implementation of stronger water conservation/demand man-
agement actions - beginning with low-flow toilets, shower heads, and other fixtures -
should be undertaken in formal and, to the extent relevant, informal water supply
systems (Rosenzweig et al., 2007). As higher temperatures bring higher evaporative de-
mand, water reuse also can play a key role in enhancing water-use efficiency, especially
for landscape irrigation in urban open spaces (Major et al., 2011).
3) TRANSPORTATION
Transport-related climate risks that a city faces are contingent on its unique and com-
plex mix of transportation options (Wilby, 2007). The location of transportation systems
either at ground level, underground or as elevated roads and railways changes the im-
pacts of different climate variables, particularly to flooding (Prasad et. al., 2009). Tun-
nels, vent shafts, and ramps are clearly at risk. Flooding necessitates the use of large and
numerous pumps throughout these systems, as well as removal of debris and the repair
or replacement of key infrastructure, such as motors, relays, resistors, and transform-
ers. Besides sea-level rise and storm surge vulnerability, steel rail and overhead electri-
cal wire associated with transportation systems are particularly vulnerable to excessive
heat. Overheating can deform transit equipment, for example, causing steel rail lines to
buckle, throwing them out of alignment, which potentially can cause train derailments
(Mehrotra et al., 2011). Heat can also reduce the expected life of train wheels and auto-
mobile tires. Roadways made of concrete can buckle or “explode” and roads of asphalt
can soften and deteriorate more rapidly.