The new concept of the Disruption Index (DI) as an indicator to measure cascading effects in urban areas

Abstract:

Apart from the loss of lives, injuries and homeless resulting from an earthquake, not only the economy and physical landscape are altered, but also the lives of citizens and their places of work are dramatically altered. If critical services and functions are disrupted for more than a reasonable time period, consequences can be severe. All communities are at risk and face potential disaster, if unprepared.

The Disruption Index (DI) is a tool that allows the representation of a complex, multidimensional, situation in a concise and easier way, providing institutions and communities with a way to identify the global earthquake impact in a geographical area, the elements at risk, and the means to reduce it. Understanding how the loss and cascading effects across a number of areas might be correlated during a single earthquake is critical to evaluate risk. The application of this tool, prior-to a catastrophe, assumes a huge importance for earthquake risk professionals and planners to understand their impacts and to start building earthquake resilient cities. Post-to an event, this tool provides an assessment of its extent and impact considering the propagation effects, developed in a Geographic Information System (GIS) environment. The DI was already tested, calibrated after several earthquakes and applied in Portugal, Italy, Spain and Iceland.

 The next step in this research is to implement this tool directly into web portals or websites as well as PAGER or GDACS platforms to:

- Rapidly assess an earthquake impact in a region following significant events. Nowadays the institutions used the shake maps; it’s an important tool but cannot reflect the impact on livelihoods and the cascade effects. The DI maps can be used by state and local organizations, both public and private, for post-earthquake response and recovery, public and scientific information.