Towards spatially distributed quantitative assessment of tsunami inundation models

Abstract

This paper presents a framework and data for spatially distributed assessment of tsunami inundation models. Our associated validation test is based upon the 2004 Indian Ocean tsunami, which affords a uniquely large amount of observational data for events of this kind. Specifically, we use eyewitness accounts to assess onshore flow depths and speeds as well as a detailed inundation survey of Patong City, Thailand to compare modelled and observed inundation. Model predictions matched well the detailed inundation survey as well as altimetry data from the JASON satellite, eyewitness accounts of wave front arrival times and onshore flow speeds. Important buildings and other structures were incorporated into the underlying elevation model and are shown to have a large influence on inundation extent.

The influence of land cover roughness on the results of high resolution tsunami inundation modeling

“…5), which is in agreement with results from Jakeman et al (2010) and Schlurmann et al (2011). However, the approach, to assign very high Manning values (M = 2.5 m 1/3 s −1 ) to resistant buildings as proposed by Gayer et al (2010) and Leschka et al (2009), provides similar results in the validation points, and for flux and current speeds (Figs.…”

“…Recently also Suppasri et al (2011) modeled inundation for Khao Lak and Patong Beach to determine the structural fragility of buildings against tsunamis based on satellite images taken before and after the 2004 tsunami. Goto et al (2007) used a detailed inundation simulation to understand the transport processes of boulders at Cape Pakarang, Khao Lak, and Jakeman et al (2010) analyzed inundation in Patong Beach, taking especially buildings into account.…”

“…Investigations on the influence of buildings and on how to account for them in numerical simulations have been conducted by Gayer et al (2010), Jakeman et al (2010), Liu et al (2002), Schlurmann et al (2011), and Taubenböck et al (2009). Jakeman et al (2010 analyzed the influence of buildings in a hydrodynamic model for Patong Beach, Thailand, concluding that urban areas act as dissipaters reducing the volume of water onshore, while increasing flow velocities between buildings.…”

“…The influence of buildings on inundation patterns has been analyzed for Patong Beach (resistant buildings, high building density), Khao Lak (few buildings, hotels, larger distance between buildings) and Ban Nam Khem (non-resistant houses, poor quality). Four different scenarios (compare also Gayer et al, 2010;Jakeman et al, 2010;Taubenböck et al, 2009) were simulated to determine the one that fits best with the 2004 event:…”

“…For detailed tsunami inundation modeling very accurate data on bathymetry and topography are necessary Taubenböck et al, 2009). Moreover, an inaccurate or unknown representation of the surface roughness induced by vegetation and built environment may lead to inaccurate simulations (Gayer et al, 2010;Jakeman et al, 2010). Many authors argue, for example, that coastal forests like mangroves or casuarina forests attenuate wave energy to some extent (Dahdouh-Guebas et al, 2005;Danielsen et al, 2005;Kathiresan and Rajendran, 2005;Mazda et al, 1997;Wolanski, 2007) and might thus influence inundation patterns, while others request more data and more research on that topic to really prove this statement (Kerr et al, 2006;Kerr and Baird, 2007).…”