Scientists in the United States have created the most detailed digital map to track the changing racial diversity of every neighbourhood in the country.
Researchers from University of Cincinnati (UC) in the US applied NASA map making techniques to 20 years of data collected by the US Census Bureau to build one of the most detailed racial-diversity maps ever created.
They take advantage of NASA land-cover grids made up of 30-square-metre blocks. Using this grid system, they can more precisely group people where they actually live by recognising lakes, parks, factories and otherwise uninhabitable areas.
Researchers combined land-cover mapping techniques with cumbersome volumes of federal data collected every 10 years in the census.
The zoomable map shows at a glance how the racial composition of neighbourhoods changed between 1990 and 2010, researchers said.
"People do not realise that the US is a diverse country but at the same time is still very segregated," said Tomasz Stepinski, professor at UC.
"The maps can tell us much more about racial composition and can be used by everyone. They do not require expert knowledge to understand the result, so I think maps can be used by a broader community," said Anna Dmowska of Adam Mickiewicz University in Poland.
"The maps allow users to create their own smaller study area and then glean data from it. In some cities, they tell the story of recent immigration in America," Stepinski said.
"For example, the maps demonstrate the influx of Asian immigrants in San Francisco over the last 20 years. Many of these newcomers are Southeast Asians who were drawn to the area by the Silicon Valley boom," he said.
"If you put the population geography together with an understanding of the social meaning of that road, you can tell a pretty powerful story about what segregation means," said Jeffrey Timberlake, an associate professor at UC.
The study was published in the journal PLOS One.