Cascading hazards

Hazards that are related in a systemic causal relationship and expressed in a sequence of secondary events in natural and human systems that lead to physical, environmental, social, or economic disruption, and where the resulting impact is significantly larger than under a single hazard event.

Notes:

1. Cascading hazards have a relationship to cascading impacts, which refer to the social, economic and political consequences related to the hazards themselves. Cascading impacts are sometimes referred to as a "Domino effect".

2. Cascading hazards may also be referred to as "Concatenated hazards", which are factored into multi-hazard risk assessment. See also “Disaster risk assessment”, and "Multi-hazard".

3. The impacts of cascading hazards are conditioned by the variable vulnerabilities of systems and their components. They are complex and multi-dimensional and are associated more with the magnitude of vulnerability than with that of the hazard (cf. Pescaroli & Alexander, 2015).

4. See also “Direct and indirect loss”, “Infrastructure interdependencies”, “Systemic risk”, and “Organizational learning”.

Reference:

Modified from IPCC (2019). Annex I: Glossary [Weyer, N.M. (ed.)]. In: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. by DRI Lexicon Project Expert Panel, Febuary 2023

URL: IPCC

Reference for Note 4: Pescaroli, G., & Alexander, D. (2015). A definition of cascading disasters and cascading effects: Going beyond the “toppling dominos” metaphor. Planet@ risk, 3(1), 58-67.

Liquefaction of soil and incapacitation of ports following Haiti earthquake

Two major secondary hazards following the 2010 Haiti Earthquake were liquefaction and landslides, which resulted in increased damage and loss after the earthquake. When loosely packed and water-logged sediment at or near the ground surface is shaken because of earthquake forces, it loses its strength. This is called liquefaction. Most of the flatlands near Port-au-Prince are composed of loose sedimentary material and such soil composition favours liquefaction. Much of the liquefaction occurred around the international port and docks of Port-au-Prince, Haiti’s capital and most populous city. As a result of extensive liquefaction, lateral spreading occurred along the wharf. This resulted in the collapse of jetties, ramps and cranes, which were then submerged in the bay. Satellite imagery revealed that the south pier lost several sections and the north wharf completely collapsed, leaving important facilities in the water. With the seaports incapacitated, the transport of aid supplies and personnel for relief and recovery operations was greatly hampered. It took three months for the ports to resume partial operations.

 

Sources:

Go Back