GEM Ontology and Taxonomy

Overview
The development of a global earthquake risk model requires a solid methodological foundation and terminology in order to achieve a shared understanding across the many fields and endeavors GEM will address. The methodological foundation and terminology are termed an Ontology and Taxonomy (respectively, O&T).

Ontology refers to the entire framework that will guide GEM’s development – the set of concepts, and the relationship between those concepts that will allow determination and communication of earthquake risk. While no widely accepted earthquake-specific ontology currently fully satisfies the needs of GEM, much work has been done which can be built upon, such as what in the earthquake arena is often termed the “Esteva-Cornell approach”.

Taxonomy is a part of the ontology, and refers to the classification of things in an ordered system, that reflects their relationship. The GEM taxonomy aims to address hazard, asset, risk and consequence related issues. There are many systems for describing buildings from a seismic risk estimation perspective, but none of them is entirely satisfactory for GEM’s purposes. The GEM taxonomy should be able to distinguish differences in seismic performance between different building types, ranging from highly vulnerable stone masonry buildings to modern buildings designed in compliance with the latest building codes. A challenge will be to cover global building construction practices, ranging from vernacular dwellings in African villages to reinforced concrete highrises in Chile. The taxonomy will be able to characterize each building type by several attributes, including structural system, construction material, type of floor and roof structure, building height, horizontal and vertical irregularity, etc. Each building type will be described with a sufficient definition and images to facilitate field identification.

The GEM taxonomy aims to address hazard, asset, risk and consequence related issues. The taxonomy developed during the first five years of GEM will be restricted to buildings (i.e., infrastructure and lifelines are not addressed although they may be considered at a later stage).

The project has a duration of two years, with an initial intense phase of six months beginning in 4th quarter of 2010.

Approach
There are five tasks that will be carried out in order to develop a comprehensive GEM Ontology and Taxonomy which is commonly shared and is deployed within the various components of GEM.

• Task 1 Development Plan: How GEM's various groups will be involved in the development of the GEM Ontology, and in the development and maintenance of the GEM Taxonomy.
• Task 2 Ontology: Development of the GEM Ontology. 
• Task 3 Taxonomy: Development of the GEM Taxonomy. 
• Task 4 Evaluation and Testing: Evaluation of the appropriateness, usefulness, accuracy and comprehensiveness of the developed O&T.
• Task 5 Information Programme: Outreach to various GEM-related audiences. 

All tasks are described in more detail on a dedicated page.

Consortium
This project is carried out by the Alliance for Global Open Risk Analysis (AGORA) in consortium with the World Housing Encyclopedia / EERI, the Pacific Earthquake Engineering Research Center and the Disaster Prevention Research Institute.

Presentations

• Outreach Meeting 2011

Contacts
The Project Director and lead for Ontology is prof. Charles Scawthorn and can be reached at cscawthorn[at]sparisk.com, with the Taxonomy Task lead being prof. Svetlana Brzev who can be reached at svetlana.brzev[at]gmail.com.