New tsunami damage functions developed in the framework of SCHEMA project: application to European-Mediterranean coasts

Abstract

Abstract. In the framework of the European SCenarios for tsunami Hazard-induced Emergencies MAnagement (SCHEMA) project (www.schemaproject.org), we empirically developed new tsunami damage functions to be used for quantifying the potential tsunami damage to buildings along European-Mediterranean coasts.Since no sufficient post-tsunami observations exist in the Mediterranean areas, we based our work on data collected by several authors in Banda Aceh (Indonesia) after the 2004 Indian Ocean tsunami. Obviously, special attention has been paid in focusing on Indonesian buildings which present similarities (in structure, construction material, number of storeys) with the building typologies typical of the EuropeanMediterranean areas.An important part of the work consisted in analyzing, merging, and interpolating the post-disaster observations published by three independent teams in order to obtain the spatial distribution of flow depths necessary to link the flowdepth hazard parameter to the damage level observed on buildings. Then we developed fragility curves (showing the cumulative probability to have, for each flow depth, a damage level equal-to or greater-than a given threshold) and damage curves (giving the expected damage level) for different classes of buildings. It appears that damage curves based on the weighted mean damage level and the maximum flow depth are the most appropriate for producing, under GIS, expected damage maps for different tsunami scenarios.

Building Damage Assessment Using Scenario Based Tsunami Numerical Analysis and Fragility Curves

“…A number of hydrodynamic features can be considered demand parameters in fragility functions. Most of the existing works [4,7,15,25,33] derive fragility curves based on inundation depths as the only demand parameter. However, [9,17] recommended that other tsunami features like velocity, force, scouring, and debris impact to be included in the model.…”

“…This approach can serve as an indirect measure of structural vulnerability; however, for areas with little or no record of damage caused by tsunami, accurate fragility curves cannot be developed. The concept of using existing fragility curves to determine structural damage probability is new, with major contributions from [7,12,13]. We extend this idea to Imwon Port in Korea by proposing improved numerical models with improved bathymetric resolution to capture flow features at the individual structure level; we also use fragility curves based on an advanced statistical approach and vast building damage data from the 2011 Great East Tsunami in Japan.…”

“…To our knowledge, only a few studies to date have addressed this issue. Valencia et al [7] developed damage functions for the European-Mediterranean coasts, for which no post-tsunami observations exist, by analyzing the structures damaged in Banda Aceh (Indonesia) after the 2004 Indian Ocean tsunami. Wiebe and Cox [12] estimated building damage and economic loss for Seaside, Oregon caused by a hypothetical tsunami using the inundation based fragility curves of [4].…”

Inventory of uncertainties associated with the process of tsunami damage assessment on buildings (SCHEMA FP6 EC co-funded project)

“…the vulnerability class of exposed buildings (or roads, or bridges, etc.) following for example the typology proposed by Valencia et al (2011). Once the buildings inventory and classification has been completed, it is possible to cross this with the modelled maximum flow depths in order to allocate a maximum expected flow depth for each building of the data base.…”

“…The variation (uncertainty) in the output of a numerical model can be apportioned, qualitatively or quantitatively, through a sensitivity analysis, to different sources of variation in the input of the model. The publications about this type of analysis are numerous (e.g., Weisz and Winter, 2005;Grilli et al, 2007;Dao and Tkalich, 2007;Synolakis et al, 2007;Hébert et al, 2007).…”