Thanks to this world map that shows the density of people with the surname Blau in different countries, you can get an idea not only of the popularity of the surname Blau in each country but also of the different migrations of people surnamed Blau.
The quantity of people with the surname Blau that we can find in each country can help us discern the origin of the surname Blau, as logic tells us that the place with the most people surnamed Blau will be the country or area of origin of the surname Blau.
Locating at a single glance the countries where the surname Blau is more abundant, as well as the areas of the globe where there are hardly any people with the surname Blau, is of great utility for individuals interested in surnames, and specifically in the surname Blau, as it allows them to quickly and easily visualize the data and its distribution."