A risk analysis for floods and lahars: case study in the Cordillera Central of Colombia

Matthias Künzler (), Christian Huggel and Juan Ramírez

Natural Hazards: Journal of the International Society for the Prevention and Mitigation of Natural Hazards, 2012, vol. 64, issue 1, 767-796

Abstract: The glacier-covered Nevado del Tolima in the Colombian Cordillera Central is an active volcano with potential lahars that might be more hazardous than those on Nevado del Ruiz. Furthermore, rainfall-triggered floods and landslides notoriously and severely affect the region. For effective disaster prevention, a risk analysis is of primary importance. We present here a risk analysis methodology that is based on the assessment of lahar and rainfall-related flood hazard scenarios and different aspects of vulnerability. The methodology is applied for populated centres in the Combeima valley and the regional capital Ibagué (~500,000 inhabitants). Lahar scenarios of 0.5, 1, 5, and 15 million m 3 volume are based on melting of 1, 2, 10, and 25 % of ice, firn and snow, respectively, due to volcanic activity and subsequent lahar formation. For flood modelling, design floods with a return period of 10 and 100 years were calculated. Vulnerability is assessed considering physical vulnerability, operationalized by market values of dwelling parcels and population density, whereas social vulnerability is expressed by the age structure of the population and poverty. Standardization of hazard and vulnerability allows for the integration into a risk equation, resulting in five-level risk maps, with additional quantitative estimate of damage. The probability of occurrence of lahars is low, but impacts would be disastrous, with about 20,000 people and more directly exposed to it. Floods are much more recurrent, but affected areas are generally smaller. High-risk zones in Ibagué are found in urban areas close to the main river with high social vulnerability. The methodology has proven to be a suitable tool to provide a first overview of spatial distribution of risk which is considered by local and regional authorities for disaster risk reduction. The harmonization of technical-engineering risk analysis and approaches from social sciences into common reference concepts should be further developed. Copyright Springer Science+Business Media B.V. 2012

Keywords: Risk analysis; Vulnerability; Natural hazard; Colombia; Combeima; Nevado del Tolima; Lahar; Cordillera Central (search for similar items in EconPapers)
Date: 2012
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
http://hdl.handle.net/10.1007/s11069-012-0271-9 (text/html)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:spr:nathaz:v:64:y:2012:i:1:p:767-796

Ordering information: This journal article can be ordered from
http://www.springer.com/economics/journal/11069

DOI: 10.1007/s11069-012-0271-9

Access Statistics for this article

Natural Hazards: Journal of the International Society for the Prevention and Mitigation of Natural Hazards is currently edited by Thomas Glade, Tad S. Murty and Vladimír Schenk

More articles in Natural Hazards: Journal of the International Society for the Prevention and Mitigation of Natural Hazards from Springer, International Society for the Prevention and Mitigation of Natural Hazards
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().