Geo-environmental analysis of the Hanshin-Awaji great earthquake disaster

Abstract

It is impossible to predict when and where an earthquake will occur with the present state of technology. It is, however, possible to estimate which areas are likely to be damaged in case of a major earthquake. Information obtained by archaeological excavations is useful in predicting future earthquake damage. We can also identify such areas through excavations, as well as learn about previous damage due to past earthquakes (Fig. 1). In the Southern Hyogo Prefectural Earthquake, the delta and coastal areas suffered heavy damage. The former lagoons (shallow coastal areas) in particular were heavily damaged. These are areas of soft, swampy ground (Figs. 2 and 3). Railroads and expressway also suffered heavy damage on the boundary between hard and soft ground (Figs. 3 and 4). Houses and railroads were damaged in different areas. Houses and buildings on soft ground suffered the greatest damage. In particular, devastating damage was seen in former river channels which had been abandoned for 2, 500 years. Many people were killed along the former river channels (Figs. 5 and 6). The extent of this earthquake disaster, however, was not solely dependent on natural conditions. The vulnerable natural environment is closely related to social and economic factors. There have been serious floods in Kobe immediately after large earthquakes in the past. We must be cautious of floods in Kobe City in the near future.