Civil Engineering Reference
In-Depth Information
sions on retrofi tting and insurance and collaborate and exchange data,
results and opinions amongst each other. It is envisaged that the datasets
and models will, however, be continuously evolving after 2013, and hence
OpenQuake will be built in such a way that it can capture the world's best
understanding of data, the earth and earthquake behaviour, and the built
environment at any given moment in the future. In the years after 2013,
GEM's growing user-community will be able to add data, exchange knowl-
edge on methods for data analysis and other issues, and will in that way
contribute to the continuous improvement of the risk assessment at a global
scale.
The ultimate aim of GEM is to create a global earthquake risk model
that is as homogeneous as possible, based on hazard and risk models that
explicitly account for epistemic uncertainties though logic-trees, and that
relies on highly reproducible procedures. Within GEM's fi rst working pro-
gramme (2009-2013) it will not be possible to incorporate all the data
effectively available, nor cover all the countries in the world in a uniform
way. Also, it is unlikely that secondary hazards such as tsunamis and land-
slides will be covered within the fi rst set of models. During this fi rst Working
Programme GEM will hence create tools and standardised methods for
obtaining and analysing data, and GEM collaborators/affi liated researchers
will use these tools to begin the process of assembling the needed (global)
datasets, hereby producing data coverage for the world that is more uniform
and complete than before.
30.1.2 Scientifi c modules
GEM's global earthquake risk model is based on a probabilistic framework
(see e.g. McGuire, 2004) and consists of seismic hazard (represented by the
exceedance probability of levels of ground shaking resulting from earth-
quakes, within a given time span), vulnerability (defi ned as the probability
of loss given a level of ground shaking for physical vulnerability, or through
indicators that envelop the socio-economic factors known to be driving
forces of vulnerability), and exposure (the elements at risk). Combining
these components within the risk module allows for an estimation of direct
damage and loss as well as risk indicators or indices. Indirect economic loss
and the long-term impacts of earthquakes fi t within the risk and impact
analysis module and then decision-making tools can be built on top of the
aforementioned output, as illustrated in Fig. 30.2. The development focus
within GEM is on the components of hazard, physical vulnerability and
exposure, calculation of direct losses (total losses and insured losses), com-
plemented by derivation of indexes for social vulnerability and disaster
resilience for calculation of total risk, and decision support tools that con-
sider the cost-benefi t analysis of retrofi tting and insurance.
Search WWH ::
Custom Search