Liquefaction Distribution in the Central Part of Fukui City during the 1948 Fukui Earthquake: Comparison of Micro-topographic Classification Map and Liquefaction Hazard Map

Abstract

We present the detailed distribution of liquefaction during the 1948 Fukui Earthquake in the central part of Fukui City by interpreting air-photographs taken immediately after the earthquake. Comparing this result with the liquefaction hazard map published by Fukui City, the actual distribution of liquefaction is not consistent with the risk assessment. The reason for this contradiction is that because the liquefaction hazard map of Fukui City was evaluated based only on information about the thickness of soft sediments. The results of the current study are also compared with geomorphic classification maps published by Geographical Information Authority of Japan, the land condition map, and the landform classification map for flood control （ the first edition and the updated edition ） , respectively. They show that the liquefaction distribution overlaps with micro-topography such as the former river channel and the natural levee where liquefaction is likely to occur. From these comparison results, the importance of considering micro-topography when preparing a liquefaction hazard map can be recognized, and it is effective to refer to previously published geomorphic classification maps. However, since these maps are created for various purposes and have slightly different interpretations of micro-topography, multiple maps should be integrated to assess liquefaction potential.