Population versus Elevation - adjusted for available land area
Integrated population density (people/sq.km) by altitude, that is, the distribution of human numbers by altitude, divided by the area of land available at each altitude
The ratio of population at each elevation (taken from the previous figure) divided by occupied land area at each elevation (taken from the previous figure) is defined as the integrated population density at each elevation is shown above. The integrated population density of the area between sea level and 100 m elevation is significantly larger than that of any other elevation range and represents far more people. The broad bulge centered around 2300 m elevation arises primarily from the local high density of the trans-Mexican plateau and the vast numbers of people living in the south-central Asian highlands. Although the integrated population density at elevations around 2300 m exceeds that around 200-300 m and approaches that at 0-100 m, the number of people who live between 2000 and 2500 m is small (130,000,000) compared to the number of people living within 500 vertical meters of sea level (4,400,000,000). Almost all the land on Earth lower than 1000 m is occupied (at a density of at least 1 person per 147 sq.km(0.007 person/sq.km)). Greenland and Antarctica are the major unoccupied land masses and have higher elevations as a result of their ice sheets.
One significant result of this study is that most of the world's
population residing at low elevations occurs at moderate population densities
rather than at high densities typical of large cities. Future estimates
of the impact of coastal hazards should consider that a significant number
of coastal residents may not live in large cities, and should strive to
match higher-resolution data on elevation and population distribution. The
land in the lowest 100 m is primarily coastal plain but also includes some
low-elevation drainage basins that extend significant distances inland.
These results reflect the collective human tendency to settle the low-lying
peneplains that facilitate agriculture, transportation and trade in many
regions. By populating these areas humans increase their exposure to the
climatic and coastal hazards associated with these environments.
Back to Main Page