The present state of underground space utilization in Japan, its future prospects and comparisons with Cappadocia, Turkey

Recently, urban underground space is often used as an alternative space for lifelines or subways. However, it is not directly related to human life. In recent years, some museums are constructed underground and such a utilization becomes widespread. The authors carried out a survey of underground structures and its interior environment at Cappadocia, Turkey. Underground structures have been used in this region for more than 2,000 years. In this article, the geologic stability, interior environment of semi underground and underground facilities are presented with a particular emphasis on the climate of underground space. The results indicate that the temperature and humidity conditions of semi underground residences are not inferior to that of present houses in Japan. In addition, some new examples of underground space utilization in Japan are introduced. The authors introduced some parts of the report by the Provisional Investigation Committee for Deep Subterranean Utilization and discussed the implications of the report. Finally, the future prospects of underground space utilization in Japan are presented and compared with the examples at Cappadocia.