Hazard: Volcano

Country: Philippines

H
[ Hazard ]
Mount Pinatubo

Event Date

June 15, 1991

Volcanic Explosivity Index (VEI)

6

Notable Features

• Largest Eruption to affect a densely populated area
• Mud flows/avalanches were generated
• Volcanic ash cloud of hundreds of miles was developed
• Impacts of the eruption continue to this day.

Source(s)

• USGS

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Hazard: Volcano

Country: Colombia

H
[ Hazard ]
Nevado del Ruiz

Event Date

November 13, 1985

Volcanic Explosivity Index (VEI)

3

Notable Features

• Second largest volcano-related disaster of 20th Century
• Mud flows/avalanches were generated

Source(s)

• USGS
• NOAA

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Ex
[ Exposures ]
Mount Pinatubo

Principal Area of Impact

Central Luzon Region

  • Population at Time of Event
    6.339 Million Estimated (Region III – Central Luzon, 1990)

Previous Year's Gross Domestic Product (GDP)

$44.31 Billion USD (1990)

Previous Year's Gross Domestic Product Per Capita

$715.30 USD (1990)

Source(s)

• World Bank Group
• 2010 Census and Housing Population, Philippines National Statistics Office

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Ex
[ Exposures ]
Nevado del Ruiz

Principal Area of Impact

Armero /Central Colombia

  • Population at Time of Event
    2.113 Million Estimated (Caldas and Tolima Departments, 1985)

Previous Year's Gross Domestic Product (GDP)

$38.25 Billion USD (1984)

Previous Year's Gross Domestic Product Per Capita

$1,299.45 USD (1984)

Source(s)

• World Bank Group
• National Administrative Department of Statistics, Colombia

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V
[ Vulnerabilities ]
Mount Pinatubo

Governance

World Bank Group Indicator –
Regulatory Quality (Percentile Rank):
Not Available

World Bank Group Indicator -Government Effectiveness (Percentile Rank):
Not Available

World Bank Group Indicator –
Rule of Law (Percentile Rank):
Not Available

World Bank Group Indicator – Voice and Accountability (Percentile Rank):
Not Available

World Bank Group Indicator – Political Stability and Absence of Violence (Percentile Rank):
Not Available

Corruption

World Bank Group Indicator – Control of Corruption (Percentile Rank):
Not Available

Transparency International Corruption Perception Index Score:
Not Available

Transparency International Corruption Perception Index Rank:
Not Available

Development

World Bank Group - GINI Index:
Not Available

Human Development Index Score (HDI):
0.586 (1990)

Human Development Index Rank (HDI):
Not Available

Source(s)

• World Bank Group
• Transparency International
• Human Development Report 1990

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V
[ Vulnerabilities ]
Nevado del Ruiz

Governance

World Bank Group Indicator –
Regulatory Quality (Percentile Rank):
Not Available

World Bank Group Indicator -Government Effectiveness (Percentile Rank):
Not Available

World Bank Group Indicator –
Rule of Law (Percentile Rank):
Not Available

World Bank Group Indicator – Voice and Accountability (Percentile Rank):
Not Available

World Bank Group Indicator – Political Stability and Absence of Violence (Percentile Rank):
Not Available

Corruption

World Bank Group Indicator – Control of Corruption (Percentile Rank):
Not Available

Transparency International Corruption Perception Index Score:
Not Available

Transparency International Corruption Perception Index Rank:
Not Available

Development

World Bank Group - GINI Index:
Not Available

Human Development Index Score (HDI):
Not Available

Human Development Index Rank (HDI):
Not Available

Source(s)

• World Bank Group
• Transparency International

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EmR
DR
CatR
[Risk]
Mount Pinatubo

Total Affected Population

1,036,065

  • Total Deaths
    640
  • Injured
    Not Available
  • Homeless
    Not Available

Total Damage

$367.14 Million (In 2015 USD)

Source(s)

• EM-DAT
• CPI Calculator

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EmR
DR
CatR
[Risk]
Nevado del Ruiz

Total Affected Population

12,700

  • Total Deaths
    21,800
  • Injured
    5,000
  • Homeless
    Not Available

Total Damage

$2.2 Billion (In 2015 USD)

Source(s)

• EM-DAT
• CPI Calculator

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Takeaways

With decades of perspective now on these two volcano hazard events, it is clear that the November 13, 1985 Nevado del Ruiz eruption and subsequent lahar (a mixture of rocks, soil and other debris triggered by a volcanic eruption) qualifies as a true catastrophe for the city of Armero, its principal zone of human impact, of which only a remnant (and relocated) town remains. The June 15, 1991 Pinatubo eruption, however, qualifies as “only” a disaster for its principal impact area.

In 1845 and well documented, what would become the site of the city of Armero was engulfed by a lahar off Nevado del Ruiz. Founded 50 years later, Armero was developed on that solidified lahar, exposing it to a similar hazard event in the future, which began to show precursors in 1990. On the night of November 13, 1991, the volcano erupted and sent a lahar toward Armero that trapped and killed most of the city’s pre-event population of approximately 30,000. Given its siting and practically speaking, little could have been done about Armero’s physical vulnerability, but its human vulnerabilities were a different story, because while the volcano was being monitored, the systems were not real-time, and the meaning of the data was variously interpreted, misinterpreted, and even denied. The event (a total EM-DAT death toll of 21,800) became a largely avoidable warning-alert-evacuation failure:

The catastrophe … was caused, purely and simply, by cumulative human error – by misjudgment, indecision and bureaucratic shortsightedness. In the end, the authorities were unwilling to bear the economic or political costs of early evacuation or a false alarm, and they delayed action to the last possible minute. Catastrophe was the calculated risk, and nature cast the die…. Armero could have produced no victims, and therein lies its immense tragedy” (Voight 1990: 383).


To the extent that the Armero catastrophe had a silver lining, intensive media coverage created a scandal that opened a “window of opportunity” for fundamental policy and organizational improvements in monitoring, hazard analysis, risk assessment, public information, and event management throughout Colombia, from the national to the local level.

In the Philippines, Mt. Pinatubo had been relatively dormant for more than 500 years but showed some late warning signs in 1991, erupting on June 15 and killing a reported 640 people (EM-DAT). Compared to Armero, it offers a classic contrast where the national and international scientific communities, government decision-makers, local communities, emergency management officials, and the Philippine and U.S. militaries managed to maintain close communication and trust even under duress and organized timely evacuations: “As many as 20,000 lives were saved as a consequence…. Despite considerable uncertainties, the eruption was correctly forecast and more than 85,000 were evacuated…. Although about 200,000 were ‘permanently displaced’ by lahars, only about 400 fatalities are attributed to lahars. Timely warnings from scientists and police helped to keep most people safe” (GVM 2015: 18-19). In that sense, Pinatubo 1991 was a warning-alert-evacuation success.

The prime takeaway: the importance of effective communication, coordination, credibility, and trust between (a) the scientific community, (b) emergency management officials, (c) political authorities, and (d) the general public.

References: (1) Voight, Barry, “The 1985 Nevado del Ruíz volcano catastrophe: anatomy and retrospection,” Journal of Volcanology and Geothermal Research 44 (1990): 349-386, and (2)
Global Volcano Model (GVM). < http://globalvolcanomodel.org/ > International Association of Volcanology and Chemistry of the Earth’s Interior Global volcanic hazards and risk, Technical background paper for the UN-ISDR Global Assessment Report on Disaster Risk Reduction 2015
< http://www.preventionweb.net/english/hyogo/gar/2015/en/bgdocs/GVM,%202014b.pdf >