Global Report on Human Settlements 2007 - PoA-ISS

Disaster risk: Conditions, trends and impacts
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preparedness of individual cities. This is evident when
comparing the contrasting cases of Kobe (Japan) (hit by a 7.2
Richter magnitude earthquake in 1995) and Marmara
(Turkey) (hit by a 7.4 Richter magnitude earthquake in
1999). The Kobe (or Great Hanshin) earthquake was among
the worst disasters to have befallen modern Japan since it
claimed 6433 lives. The Marmara earthquake was similarly
catastrophic; but with 18,000 lives lost, was three times as
deadly as the Kobe earthquake. 17 In Kobe, strong engineering
standards reduced losses; but a lack of planning for social
systems to identify vulnerable groups and help in response,
relief and reconstruction compounded losses. In Marmara,
decades of ineffective building and planning regulation
meant many modern buildings were not adequately resistant
to earthquakes, and accumulated risk translated into high
human loss. As in Kobe, failure in social planning also undermined
response and reconstruction. The Tangshan
earthquake in China in 1976 similarly illustrates how differential
vulnerability shapes loss in different human
settlements (see Box 7.4).
DISASTER IMPACTS
This section differentiates between and discusses the main
impacts of disasters. The capacity for disaster impacts to
cause knock-on consequences and additional risks through
secondary human-made disasters and the ecological impacts
in the city is also examined.
Although the review of natural and human-made
disasters goes some way in indicating their destructive
power, it can only show tip-of-the-iceberg losses. Gaps in
data and contradictory statements make comprehensive
assessment of disaster impacts difficult. Even assessments of
disaster incidence, although made easier by global media, are
not easily undertaken at the global scale, where there is no
standard system for verifying local reports.
Systematic gaps in disaster data collection and presentation
mean that loss is underestimated in three different
ways:
• Psychological and livelihood impacts are seldom
recorded, with the majority of disaster impact data
focusing on mortality and economic loss. 18
• Macro-economic loss estimates cannot easily capture
the secondary and knock-on consequences of disaster
for economic production and trade.
• Disasters affecting small urban settlements and smallscale
disasters in large cities are often overlooked,
despite evidence suggesting that, in aggregate, smallscale
disasters may be associated with at least as much
suffering and loss as the large-scale disasters in cities
that make front page news. 19
At a minimum, psychological trauma, livelihood losses and
losses to productive infrastructure should be included in
measuring the full impact of disasters.
Box 7.4 The Great Tangshan earthquake, China
The most destructive earthquake of the past 400 years occurred in Tangshan (China) in 1976.
The magnitude 7.8 earthquake occurred in the early morning while the majority of the over
1 million residents slept and lasted 14 to 16 seconds. Later in the day, the city was further
paralysed by an aftershock with a magnitude of 7.1. The official death toll published by the
Chinese government was about 240,000. More recent estimates place the total for casualties at
over 0.5 million.
While nearly 50 per cent of the population of the city of Tangshan died during the
earthquake, the neighbouring County of Qinglong had only one death out of 470,000 residents.
Scientists from the State Seismological Bureau identified six main factors that contributed to
the unprecedented destructiveness of the Tangshan earthquake, including high population
density, existence of few earthquake-resistant buildings, occurrence of shock while people were
sleeping followed by a strong aftershock later, paralysis of critical infrastructures and the
geological conditions under the city. 20 Yet, the disparity between the death toll in Tangshan and
Qinglong cannot be accounted for by these factors alone since both counties experienced
similar vulnerabilities. The divergence in the death toll between Qinglong and Tangshan comes
from an additional seventh factor: the difference in earthquake preparedness in the two areas.
Tanghsan’s over-reliance on scientific monitoring of seismic activity for national
preparedness partly contributed to the massive loss of life during the 1976 earthquake. Two
years earlier, a report by the Chinese Academy of Science had advised greater preparedness
and monitoring in North China. During the following two years, Qinglong County increased the
number of earthquake monitoring stations and intensified public education using pamphlets,
films, posters, drills and community discussions, far beyond those reported to have been undertaken
in Tangshan. Qinglong’s successful disaster mitigation was a best-case outcome of the
coordination between public administrators, scientists and the public.
Source: Pottier et al, 2007
Direct and systemic impacts of disaster
Disaster impacts can be classified as either direct or
systemic. Direct impacts include damages directly attributable
to the disaster, including lives lost and injuries and
physical damage to infrastructure and buildings. Direct (and
other) losses can also be caused by knock-on human-made or
natural disasters. For example, an earthquake can trigger
chemical fires or liquefaction. If uncontained, direct impacts
can be magnified through failures in critical infrastructure
and services in the city, leading to systemic impacts such as
outbreaks of disease, social violence and lack of access to
electricity, potable water or food. For instance, a review of
health service infrastructure in Latin America and the
Caribbean found that around half of all hospitals are sited in
high-risk areas. Perhaps not surprisingly, this report also
found that over the 1980s and 1990s, 100 hospitals and 650
health centres have been destroyed in disasters. This is a
little over 5 per cent of all hospitals in this region. 21 In turn,
such disruptions can lead to instabilities in the political
economy of the city and undermine economic development.
Systemic loss can further be differentiated into
indirect losses and secondary effects. Indirect losses
(sometimes called flow losses) are the costs of goods that
will not be produced and services that will not be provided
because of a disaster. Secondary effects are generated by
macro-economic distortions. 22
Urban areas are characterized by great diversity in
land use as well as environmental variability (e.g. in slope
angle and direction, soil properties and land altitude). This
Gaps in data …
make comprehensive
assessment of
disaster impacts
difficult