海岸統計から見た日本の海岸の改変

抄録

The ratio of artificial to natural coast is considered to be an important index for the study of coastal zone management from an environmental point of view. The length of natural coast can be used as an index showing the destruction of natural environment in the coastal zone as well. The author suggests the usefulness of indices derived from national coastal statistical data published every year by the Ministry of Construction. Toe ratio and length of artificial coastlines in areas to be protected (as specified by the Coastal Protection Law) and in other areas are presented in this study. These indices are good indicators of the differences in artificial modifications among regions in Japan. It is apparent that the statistics can be used as a robust tool for monitoring modification of natural coast. However, the lack of digital statistical data hinders the analysis. Further development of the database is strongly recommended.