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Risk Assessment Tools for Diagnosis of Urban Areas (RADIUS)

Earthquake scenarios and action plans provide city-specific objectives for disaster preparedness and mitigation, and were developed with government, science, business and academic sectors.


The Problem

Urban earthquake risk is rapidly increasing, particularly in developing countries, where many mega-cities are booming. Over the last 25 years, 1 billion people were added to the population of cities of developing countries, a disproportionate number of which are prone to earthquakes. Over the next 25 years, 2 billion more people will be added to those cities. 

Meanwhile, the earthquake-resistance of these cities has been declining. Furthermore, the resources that have been made available to manage natural disasters in cities of developing countries are directed primarily toward response, reconstruction and recovery, and not to mitigation, preparedness and prevention. Buildings should not kill people by collapsing, and damaged urban infrastructure should not halt a city’s vital social and economic life.


GHI’s Response

The United Nations General Assembly designated the 1990s the “International Decade for Natural Disaster Reduction (IDNDR)” to reduce loss of life, property damage, and social and economic disruption caused by natural disasters. In 1996, GHI joined the IDNDR secretariat and two other international institutes to play a leading role in the RADIUS initiative. The primary goal of RADIUS was to help people to understand their earthquake risk and to raise public awareness as the first step towards earthquake risk reduction. Nine case-study cities were selected worldwide to 1) develop earthquake damage scenarios and action plans; 2) develop practical tools for earthquake risk management, which could be applied to any earthquake-prone city in the world; 3) conduct a comparative study to understand urban earthquake risk around the world; and 4) promote information exchange for earthquake risk mitigation at the city level.

Long-Term Outcome

  • RADIUS case studies and action plans provided city-specific objectives for improving disaster preparedness and mitigation.

  • The initiative raised awareness of earthquake risk among decision makers, the general public and the media.

  • The involvement of representatives from the government, science, business and academic sectors helped to develop the local institutional support needed to sustain the earthquake risk mitigation efforts.

  • The initiative promoted interaction of the nine case-study cities with other earthquake-prone cities worldwide, including an online network of more than 70 seismically active cities, to share experiences.

  • The project established a worldwide network of earthquake professionals that can support continued work in comparative urban earthquake risk assessment.


Full RADIUS Report

Guayaquil, Ecuador Case Study Scenario

Tijuana, Mexico Case Study Scenario

Antofagasta, Chile Case Study Scenario

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