A German scientific research team recently released a new data set called "Global Building Atlas", constructing the most detailed global three-dimensional building map to date, covering about 97% of the buildings on the earth's surface, with a total of more than 2.75 billion buildings. It presents the spatial distribution of human built environments in the form of small three-dimensional polygons.
This achievement is regarded as an important infrastructure in the fields of urban planning, climate research, and human development monitoring, and is expected to be used to track global urbanization processes and changes in living conditions in the long term.
This project was carried out by a team led by Xiaoxiang Zhu of the Technical University of Munich, and relied on high-resolution satellite imagery, deep learning algorithms, and laser scanning technology for estimating building heights to construct a data set. The researchers first selected data from 168 cities in Europe, North America and Oceania as a reference to train the algorithm, and then input about 800,000 satellite images taken in 2019 into the system, requiring the model to automatically predict the height, volume and floor area of each building. GlobalBuildingAtlas has a spatial resolution of 3 meters by 3 meters and is designed to be updated regularly, resulting in a dynamically evolving global building database.
Newly released data has begun to reveal significant differences in building structures across regions. A study published in the journal "Earth System Science Data" pointed out that Asia accounts for about half of the global building "total", with about 1.22 billion buildings. It is also the continent with the largest total building volume in the world, with a total volume of about 1.27 trillion cubic meters. This largely reflects the agglomeration of high-density and high-volume buildings brought about by the rapid urbanization of China, India and other populous countries. Africa ranks second in terms of the number of buildings, with about 540 million buildings, but the total building volume is only about 117 billion cubic meters, showing a pattern dominated by shorter, low-rise buildings.
With the help of 3D building data, researchers can also more accurately analyze the relationship between population density, economic development and building mass, thereby conducting more comparable cross-sectional studies of different countries within the same continent. Relevant analysis shows that the total building volume in Finland is about 6 times that of Greece, while the per capita building volume in Niger is about 27 times lower than the global average. Such differences are difficult to accurately quantify and present on traditional two-dimensional maps. Three-dimensional building maps are therefore seen as a key tool for understanding global differences in residential space supply, infrastructure distribution, and urban form.
Many scholars who have long been concerned about urbanization and transportation development welcomed Global Building Atlas, believing that this result is expected to become a new basis for studying global urban expansion and spatial structure evolution. Urban planning researchers from the University of Queensland in Brisbane, Australia, said that the database can help them better track the changing shape of urban areas over time; while transportation and urban planning experts from Monash University in Melbourne, Australia, pointed out that in many areas where reliable statistics are lacking, this tool will provide an unprecedented global-scale perspective for assessing urban growth. Currently, this data set is open to the public, providing a searchable, updateable, and expandable global three-dimensional architectural base for academia, government departments, and industry.