Civil Engineering Reference
In-Depth Information
• Many current efforts use methodologies and input data that vary widely
in format and quality, making it diffi cult to compare results across
national boundaries.
• Earthquake risk estimation is a discipline where geoscience meets
engineering and social science. Often efforts are focused on only one of
these fi elds, or at maximum the combination of geoscience and engi-
neering. Inclusion of modelling and assessment of social and economic
impacts of earthquakes (on a global scale) has rarely happened until
now.
• Current initiatives do not always make clear what the primary, underly-
ing causes of risk are, whether it comes from the severity or frequency
of ground shaking, the vulnerability of the building, or lack of recovery
capability. Focused, effective mitigation requires in-depth knowledge of
the underlying causes of risk.
• Most of the existing software and methodologies are largely developed
by and for users in developed economies. Advanced (scientifi cally
grounded) models or software rarely address risks in developing coun-
tries. Furthermore there is little transfer of technology or knowledge
exchange, in order for local experts to build on their knowledge of the
local circumstances and data.
• The last global scientifi c programme on seismic hazard was carried out
in 1999 (GSHAP; Giardini
et al.
, 1999). The programme resulted in a
static map of global hazards. Maps were produced using - primarily -
seismicity catalogues and regional seismotectonic information. The map
is a static representation of the hazard knowledge at that time.
• For what concerns seismic risk estimation, reliable information of exist-
ing infrastructure (buildings, lifelines, etc.) is indispensable, and a single
database on exposed infrastructure is not currently openly available.
• Strategic decision making by governments, international bodies and
(large) companies requires transparent, uniform and global information
to be accessible in a single platform. At this time there is no such plat-
form for global earthquake risk assessment.
•
Most global earthquake risk assessments carried out in recent years (e.g.
Dilley
et al.
, 2005; ISDR, 2009) are based on empirical data, for both the
hazard and the vulnerability. Whilst an empirical approach to the defi ni-
tion of vulnerability has many advantages related to the use of real
observed loss data that is correlated to recent past events of different
levels of intensity, the same cannot be said of seismic hazard. In some
cases, data from a limited number of years (20-40 years) has been used
to defi ne the seismic hazard; such an observation length is too short for
low-frequency events such as earthquakes. There will be countries which
have not experienced a large disaster in this period but which may nev-
ertheless have a high probability of occurrence of a large magnitude
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