IASPEI - Picture Gallery

IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS002 Poster presentation 1804
Applicability of high-precision topographic model for tsunami simulation
Mr. Yoichi Murashima
Disaster Control Research Center Tohoku University IASPEI
Fumihiko Imamura, Shunichi Koshimura
As seen in 2004 Indian Ocean Tsunami, one of the main causes of damage expansion was lack of
information tsunami disaster in inundation area. The importance of hazard maps is steadily increasing.
At this time it is essential to provide detailed information, such as inundation area, tsunami damage,
evacuation centers and evacuation routes. Since developing model to predict tsunamis inundation area
is still in progress and is discussed among researchers, the reliability and accuracy of topographic data
is also essential, which change the results of run-up heights and inundation area from the simulation.
Therefore, a study on accuracy and grid size of topographic model in the simulation is the target in our
research. Recently, not only inundation area but also inundation depth and flow distribution information
is supplied by tsunami simulation. And it is a major issue that using topographic model has impact on
the results of tsunami simulation.In Japan, the 50m mesh elevation data from the Geographical Survey
Institute Japan is available in Japan at a low price and it is widely used in tsunami simulation well.
However, in recent years, it has become possible to measure elevation with adequate precision for
detailed topographic models on an extensive scale, several meters, by airborne laser profilers LiDAR,
Light Detection and Ranging, which has high measurement density and can measure minute
topographical changes. Nowadays, detailed topographic models which use data by LiDAR are being
used for tsunami prediction (Imamura et al, 2004; Tsubaki et al 2006; Iwate Prefecture, 2004).In this
study, the method of topographic models with LiDAR is introduced for tsunamis case. We discuss
whether or not the proposed topographic models made from DEM used LiDAR data and re-extracting
data of dikes and embankments is appropriate for prediction of inundation area. In addition, we study
the accuracy with grid size of topographic model which are suited for run-up tsunami simulations for
such as hazard maps, through the comparisons among the cases with the different resolutions including
50 m data by GSIJ.
Keywords: topographic, lidar, simulation