Unveiling 25 Years of Planetary Urbanization with Remote Sensing: perspectives from the Global Human Settlement Layer

In the last few decades the magnitude and impacts of planetary urban transformations have become increasingly evident to scientists and policymakers. The ability to understand these processes remained for long limited in territorial scope and in comparative capacity: data availability and harmonization were among the main constraints. Contemporary technological assets, such as remote sensing and machine learning, allow analyzing global changes in the settlement process with unprecedented detail. The Global Human Settlement Layer (GHSL) project set out to produce detailed datasets to analyze and monitor the spatial footprint of human settlements and their population, which are key indicators for the global policy commitments of the 2030 Development Agenda. In the GHSL, Earth Observation plays a key role for the detection of built-up areas from Landsat imagery upon which population distribution is modelled. The combination of remote sensing imagery and population modelling allows generating globally consistent and detailed information about the spatial distribution of built-up areas and population. The GHSL data facilitates a multi-temporal analysis of human settlements with global coverage. The results presented in this article focus on the patterns of development of built-up areas, population and settlements. The article reports about the present status of global urbanization (2015) and its evolution since 1990 by applying to the GHSL the Degree of Urbanisation definition of the European Commission Directorate General for Regional and Urban Policy (DG-Regio) and the Statistical Office of the European Communities (EUROSTAT). The analysis portrays urbanization dynamics at regional level and per country income classes to show disparities and inequalities. This study analyses how the 6.1 billion urban dwellers settle on Earth. Results show the degree of global urbanization (which reaches 85% in 2015), the more than 100 countries in which urbanization has increased between 1990 and 2015, and the tenths of countries in which urbanization is today above global average and where urbanization grows the fastest. The paper sheds light on the key role of urban areas for development, on the patterns of urban development across the regions of the world and on the role of a new generation of data to advance urbanization theory and reporting.

KEMPER Thomas;  MELCHIORRI Michele;  FLORCZYK Aneta;  CARNEIRO FREIRE Sergio Manuel;  SCHIAVINA Marcello;  PESARESI Martino; 

2018-05-17

MDPI AG

JRC111933

2072-4292,   

http://www.mdpi.com/2072-4292/10/5/768,    https://publications.jrc.ec.europa.eu/repository/handle/JRC111933,   

10.3390/rs10050768,