Interpretation of the Tsunami-inundated Area using Satellite Images in Asahi City, Chiba Prefecture and its Comparison with the Results of Numerical Simulation

Abstract

The 2011 off the Pacific coast of Tohoku earthquake caused extremely large tsunami. The authors conducted the field survey in Asahi, Chiba Prefecture after the occurrence of the earthquake. To reveal the extent of tsunami-inundated areas in Asahi, satellite images captured after the event were employed. Then, the polygons to show the tsunami-inundated areas were developed in the geographic information system (GIS). The authors compared the affected areas with the existing tsunami hazard map in Asahi. The relationship between the topographical characteristics and the inundated areas was also considered using the digital elevation model. In addition, the results of the numerical simulation of tsunami propagation were compared with the inundated areas interpreted using satellite images.