Natural Disasters - Moving Toward Improved Resilience
342489 - Development and validation of regional scale component level damage function for assessing storm surge risk in England
Friday, April 20
3:30 PM - 5:00 PM
Extra-tropical cyclone induced coastal flooding, or storm surge, is considered a frequent natural hazard in the built environment of England’s coastal floodplain area. This storm surge risk is predicted to increase due to climate change induced sea level rise and urban sprawl , which can significantly impact the regional economy. In December 2013, cyclone ‘Xaver’ produced a maximum surge depth of up to 3.5 m and caused between 1.4 - 1.9 billion USD of insured losses to property and infrastructure, including both wind damage and storm surge related flood damage [1, 2]. Due to limited historical surge damage data for this region, few studies have been conducted to develop and validate regional storm surge damage functions to estimate loss. Furthermore, the majority of currently available damage functions are limited in their ability to account for uncertainty in depth-damage estimation and lack the granularity needed for robust assessment of coastal flood risk in this region.
This study focuses on developing a regional scale component level damage function to assess storm surge risk to residential and commercial buildings in England. The component level vulnerability modeling approach developed by Karthik et al., 2014  has been used as a basis for this study. For this study, the three components considered for buildings are structures, services, and interiors. The development of damage functions has relied on flood depth-damage data from literature review, recent location-specific insurance claims, and expert engineering judgment. Component damage functions have been formulated for both primary and secondary features in an effort to reduce uncertainties within the model. Primary features include different occupancy classes, construction types, and number of stories, while secondary feature includes more detailed characteristic such as foundation types. In addition, a methodology for regions with unknown primary and secondary features has been implemented to account for relative structural vulnerability, reflecting changes in the built environment and construction practices in England. These damage functions have been validated by comparing results with USACE depth-damage curves for saltwater flooding and other published literatures. The resultant functions are suitable for use in a catastrophe modeling framework to assess losses from storm surge hazard.
 Lamond J, Penning-Rowsell E. The robustness of flood insurance regimes given changing risk resulting from climate change. Climate Risk Management. 2014 Dec 31;2:1-0.
 Wadey, M.P., Haigh, I.D. & Brown, J.M. A century of sea level data and the UK’s 2013/14 storm surges: an assessment of extremes and clustering using the Newlyn tide gauge record. Ocean Science. 2014 10(6), pp.1031–1045. Available at: http://www.ocean-sci.net/10/1031/2014/os-10-1031-2014.html [Accessed March 3, 2015]
 Ramanathan K, Kafali C. Component Level Framework for Developing Storm Surge Damage Functions for Application in Catastrophe Models. InStructures Congress 2014 2014 (pp. 1415-1425).