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3. Study Methodology
3.1 Scenario Studies
3.1.1 Human Insurance Exposure Database
To study the impact to the insurance industry from
injuries caused by catastrophes, RMS created a high resolution,
dynamic human insurance exposure database.
This database provides information on the geographic
distribution of the population at any time of the day, the
demographics, and most importantly, the insurance coverages
of that population. It covers the entire U.S. at ZIP
Code level and a considerably higher resolution for estimated
occupancies of individual buildings for large parts
of the commercial business districts of major cities.The
construction of this exposure database is described in the
next chapter.
RMS has well-established catastrophe models for
earthquake and terrorism risk. The models have been
adapted for this study to examine their impact on human
exposure.They use a detailed understanding of the physical
process of the events to construct the geographical
extent and severity ‘footprint’ of destructive forces. By
overlaying the footprint of a particular event on top of
detailed property databases, and understanding the vulnerability
of buildings to the destructive forces, it is possible
to analyze the damage likely to be caused to the
property. By adding the human occupancy of the structures
and other people in the streets, the consequences
of building damage and other harmful effects of the event on the exposed population can be analyzed to estimate
the numbers of people injured or killed.
3.1.2 Chicago Area Study
The human exposure database covers the entire U.S. A
case study area was used to assess events in detail and to
understand the granularity of an event. The Chicago
metropolitan area was selected as the location for five of
the seven catastrophe scenarios. The buildings in the
commercial city center have been individually mapped,
and detailed studies made of the commuting patterns,
demographics, and insurance penetration for the
Chicago population. This has made it possible to assess
the insurance claims that will affect the insurance losses
by coverage.
The depiction of five different catastrophe scenarios
in Chicago is not to suggest that Chicago is necessarily
more catastrophe-prone than other cities. However, the
fact that it is the second most densely populated city in
the U.S. means that any events that do occur there are
capable of causing more severe life loss than many other
places. Chicago, like any sizeable city, has had its share of
disasters, with a long history of accidents, health incidents,
and civil disturbances that have caused clusters of
casualties (1). These include the 1871 Great Chicago Fire,
the 1918 influenza epidemic (8,500 deaths), severe winters
in 1967 and 1979, and various heat waves.The concentrations
of people in a major city like Chicago exacerbate
the death toll from accidents.
Figure 3.1 The study area, Chicago, is the second most densely populated city
in the
U.S. and has a large commuting population (Image: Associated Press)
The scenarios included in this study are credible
examples of hazardous events that could occur in
Chicago, or any other major city.
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(1) O’Brien, E., and Benedict, L.“Deaths, Disturbances, Disasters and Disorders in Chicago.” Chicago Public Library.
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