GEM: Helping reduce earthquake infrastructure damage through science #BuildToLast

Earthquakes are the number one cause of fatalities due to natural hazards from 1998-2017 -- with the majority caused by the 2004 Indian Ocean and 2010 Haiti earthquakes -- and the number two cause  in terms of economic losses, second only to storms. (CRED-UNISDR 2018)

During that period, earthquakes caused more than half (56%) of the 1.3 million fatalities  and cost USD 661 billion or 23% of the USD 2.9 trillion reported economic losses. (CRED-UNISDR 2018)

Majority of the fatalities and injuries from earthquakes are due to building collapse attributed to poorly constructed buildings, lack of adherence to land-use zoning and building codes. The limited knowledge and understanding of citizens regarding the risks and mitigation measures around disasters could have also contributed to less demand for accountability. (Why Do People Die in Earthquakes? - Kenny, 2009) 

We cannot build a sustainable future with these monumental numbers. But as daunting as they might seem, they are not insurmountable and solutions are available.

What can we do to address this? 

This year’s International Day for DRR theme is ‘Build to Last’, which is Target D of the Sendai Framework: to reduce disaster damage to critical infrastructure and disruption of basic services.

GEM believes that by understanding earthquake risk better, and developing the capacity of disaster risk reduction stakeholders, we can significantly reduce fatalities, injuries and economic losses from disaster damage through open risk data sharing; the use and promotion of transparent risk assessment tools; adherence to scientific methodologies; inclusiveness and participation; and putting the interest of the public to the fore.

John Schneider, GEM Secretary General explains, “Earthquakes might be few and far in between, but when they strike the consequences are of epic proportions.” He adds that since 2009, GEM has been at the forefront of developing open analysis tools, global databases, models at various scales, and capacities of DRR scholars and practitioners to combat the damaging effects of earthquakes to human lives, infrastructure and economy.

The importance of understanding seismic hazard

The first global seismic hazard model was created within the Global Seismic Hazard Assessment Program (GSHAP) at the end of the 1990's (Giardini et al., 1999). It represented a substantial improvement in our understanding of earthquake hazard globally and offered essential information for the design of buildings and land-use planning to many countries. (GAR, 2019)

Almost twenty years later, GEM in collaboration with several organisations and projects released a new compilation of probabilistic seismic hazard models called the GEM earthquake hazard mosaic of earthquake hazard models created either at national or regional (i.e. continental) scale. (GAR, 2019)

Marco Pagani, GEM Hazard Team Coordinator explains how GEM’s Global Earthquake Hazard model can be used to help improve resilience to earthquakes.

“Many of the models contained in this collections are already used at national level to update building codes and compute risk at national level. Overall, this compilation of models provides a summary of the best science currently applied to the assessment of seismic hazard across the world at national and regional levels.”

The importance of understanding seismic risk

The calculation of earthquake risk requires a robust earthquake hazard model that defines where, how often and how severely earthquakes will strike in the future; an exposure model (building stock); and vulnerability and fragility functions (likelihood of damage to buildings).

Vitor Silva, GEM Risk Team Coordinator says, "GEM’s Global Earthquake Risk model can be used to support decision-makers in the identification of regions that are prone to higher and more frequent earthquake-induced hazards and losses, to distinguish construction types that have high vulnerability, and to devise strategies for effective risk mitigation."

To further complicate the problem, in terms of risk reduction, earthquakes pose a particular set of problems for countries in seismically active areas. ‘Return periods’ are long and unpredictable, so low mortality in the recent past is not an indicator of future earthquake risk. (Economic Losses, Poverty and Disasters 1998-2017 - CRED-UNISDR, 2018) 

A sustainable future

This is the reason why risk-informed development planning in earthquake-prone areas cannot be overemphasized. The unpredictability of earthquakes combined with their damaging and deadly effects hinder sustainable development, creation of jobs and availability of funds for poverty reduction initiatives. Understanding risk is a prerequisite for a sustainable future.

Mami Mizutori, UN Special Representative of the Secretary General for Disaster Risk Reduction says, “If it’s not risk informed, it’s not sustainable; and if it’s not sustainable it has a human cost.”

To help achieve this year’s DRR Day theme, GEM has compiled in the Related Content sidebar several links to GEM’s products useful for developing disaster risk reduction management strategies.