Assessing global earthquake risks: the Global Earthquake Model (GEM) initiative - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 812

event; these countries will not be identifi ed by many of the aforemen-
tioned risk assessments.

• Many global earthquake risk assessments lack suffi cient consideration

of the built environment in the vulnerability assessment.

In January 2009 the Global Earthquake Model (GEM) initiative launched
a pilot project, GEM1, which had the objective of developing the initial IT
infrastructure of GEM. As part of this effort, a number of existing hazard
and risk software applications were reviewed (Danciu et al. , 2010; Crowley
et al. , 2010), and the following characteristics were identifi ed as those which
should feature within GEM's software:

• allow users to upload their own hazard, vulnerability and exposure
models (and thus not be tied to any specifi c region in the world);
• combine hazard and risk calculations within a single software, but also
allow users to run hazard-only and risk-only calculations;
• be open-source software;
• be platform independent;
• have a user-friendly and intuitive user interface;
• make use of logic trees to consider the epistemic uncertainty;
• have adequate technical support and documentation;
• allow many different types of assets to be modelled (e.g. buildings,
population and eventually infrastructure);
• incorporate the modelling of spatial correlation of ground motion resid-
uals and correlation of uncertainty in building vulnerability;
• be modular and thus allow some components to be used in risk assess-
ment for other hazards;
• be scalable, with parallelised calculators;
• produce a full spectrum of products such as stochastic event sets, ground
motion fi elds, uniform hazard spectra, hazard curves and maps, disag-
gregation plots, damage and loss curves and maps.
In response to the needs outlined above and the shortcomings highlighted
by the benchmark study and existing software comparisons, the GEM initia-
tive has been launched to promote independent, uniform standards and
tools to calculate and communicate earthquake risk worldwide.

30.1.1 Global earthquake risk modelling

GEM aims to build state-of-the-art, widely accepted basic datasets, models
and software/tools for the assessment of seismic risk on a global scale and
develop a supporting IT infrastructure by the end of 2013. Users across the
globe will be able to access the basic datasets, models and accompanying
tools through GEM's risk assessment platform (OpenQuake), allowing
them not only to perform hazard and risk analyses, but also to make deci-