Disaster Management Manual
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5.2.1.1 Definition of large-scale disasters

There exist several definitions for large-scale disasters. The ones provided next are among the most prevalent and commonly used:

Organization for Economic Cooperation and Development (OECD)

OECD defines as being of large-scale any serious disaster which:

  • Causes huge casualties or property losses and/or results in infrastructure large-scale damage
  • Can hardly be coped with by only one nation or region and it shall therefore be handled by means of external resources

According to the above, a major disaster is a catastrophic, high-consequence event which:

  • overwhelms or threatens to overwhelm local and regional response capability; and
  • is caused by natural phenomenon, massive infrastructure failure, industrial accident, or malevolent action.

Indicators of capacity overload include the following:

  • inability to adequately manage immediate rescue of survivors
  • significant backlog of victims waiting to get medical care or other essential support
  • inability to protect vital infrastructure or prevent significant property damage
  • signs of uncontrolled societal breakdown and psychological trauma

Insurance companies

  • The USA Insurance Services Office defines a large-scale disaster as any event that causes a direct covered-property loss of at least $25 million (USD) and affects a certain number of insurers and insureds.
  • Swiss Re (Swiss Reinsurance Company) defines this loss amount as $38.7 million.
  • According to Munich Re (Munich Reinsurance Company), any natural disaster is defined as a catastrophe, provided that, upon occurrence of such a natural disaster that the disaster area cannot help itself with its force, but has to rely on the regional or international assistance.

International Experts

  • Ma Zongjin 1, academician of Chinese Academy of Sciences, defines as Large-scale Disaster any disaster causing more than 10,000 human casualties (deaths) and a direct economic loss of over RMB 10 billion Yuan (1.6 billion $).
  • Mohamed Gad-el-Hak 2, Professor of Biomedical Engineering and former chair of mechanical engineering at Virginia Commonwealth University, defines disasters as shown in Table 5.2.1.1.1:
Table 5.2.1.1.1 – Disaster categories, characterization and magnitude of impact
CategoryDisaster characterizationNumber of casualties or size of area impacted

Scope I

Small

<10 persons or <1 km2

Scope II

Medium

10–100 persons or 1–10 km2

Scope III

Large

100–1,000 persons or 10–100 km2

Scope IV

Enormous

1000–10,000 persons or 100–1,000 km2

Scope V

Extraordinary (Gargantuan)

>10,000 persons or >1,000 km2

 

  • Peijun Shi 3, Professor and vice-president of Beijing Normal University, member of the Expert Committee under the National Disaster Reduction Committee of China and also a member of OECD’s High Level Advisory Board on Financial Management of Large‐Scale Catastrophes, provided one of the most complete and detailed definition for large-scale disasters: “a serious disaster due to disasters encountered once in one century, causing huge human casualties and economics losses and wide range of impact, which, upon occurring, cannot be independently coped with by the disaster areas and has to be aided by means of external forces”

Generally speaking, such large-scale disasters will have an impact comparable to that of an earthquake of intensity/magnitude at least 7.0 on the Richter scale and it will usually cause:

  • total casualties (deaths) of more than 10,000 persons
  • direct economic loss of more than €10 billion ($12 billion)
  • affected area of over 100,000 km2

The aforementioned impacts are subject to the following specifications:

  • Casualties include population killed and population missing for more than 1 month;
  • Direct economic loss equal to the value of properties actually damaged within a year from and due to the disaster;
  • Affected area refers to the disaster area with human casualties or property loss or damaged ecological system due to the disaster.

Therefore, for a disaster to be characterized as being of large-scale it must meet any two of the following conditions:

  • Death toll of more than 1,000 persons;
  • Direct economic loss of more than 1 billion $;
  • Affected area of over 10,000 km2.

Table 5.2.1.1.2 summarizes qualitatively the main characteristics of large-scale disasters, as these pertain to the aforementioned definitions for the purposes of this report.

Table 5.2.1.1.2 – Large-scale disaster characteristics
Main characteristicsDisaster modeOccurenceScale of single disasterDisaster status

Uncommon

Single

Very rare

Medium

Does not change

Large scale

Rare

Large

Table 5.2.1.1.3 provides a summary of major single-mode disaster, which occurred in the 1989-2013 period with their respective impacts.

Table 5.2.1.1.3 – Large-scale disasters and respective impacts worldwide (1989-2013)
YearDisaster NameIntensity (Richter)Death Toll
(persons approx.)
Affected Area
(103km2)
Economic Losses
(billion $)

1995

Kobe Earthquake Disaster in Japan

7.3

6,434

Approx. 120

86

1998

Yangtze River Basin Flood in China

-

1,562

223

13

2003

SARS in China

 

336

Approx. 500

25

2003

European Heat Wave

-

37,451

Approx. 100

16

2004

Indian Ocean Earthquake – Tsunami Disaster

8.9

230,210 and

45,752 missing

800 x 5 km coastal line seriously damaged

Approx. 0.9

 

2005

Kashmir Earthquake in South Asia

7.6

80,000

Approx. 20

Approx. 4.2

 

2008

Burma Hurricane Disaster

-

78,000 and

56,000 missing

Approx. 20

Approx. 3.4

 

2008

Freezing Rain & Snow Disaster in Southern China

-

129 and

4 missing

Approx. 100

18.2

2008

Wenchuan Earthquake Disaster in China

8.0

69,227 and

17,923 missing

Approx. 50

Approx. 150

2010

Haiti earthquake

7.0

112,250

NA

8

2010

Chile earthquake

8.8

215

0.6

66.7

Footnotes
Reference sources

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