Distribution of Human Population with Elevation in the Japanese Islands

Abstract

The vertical distribution of population in the Japanese Islands between 1995 and 2020 is clarified using the population census. The average elevation of residence in Japan has consistently declined since 1995. Since 2005, when the accuracy of the population distribution in the census improved, the average elevation of residence decreased from 62.7 m above sea level in 2005 to 58.4 m in 2020, and the population was concentrated in areas with an elevation of less than 10 m, while the population decreased in areas with an elevation of 40 m or higher. In 2020, nearly 40 million, or about 30% of the population, lived in low-elevation zones less than 10 m above sea level. The population concentration in low-elevation zones is increasing nationwide, but there are also regional differences. The results of the population census by elevation for each prefecture indicate that growth is remarkable in the low-elevation zone of the Pacific Belt, especially in the Tokyo metropolitan area, and that the population is declining in the low-elevation zones outside the Pacific Belt.