This is a great tweet and link:

The link is to a figure-ground map of Paris that allows you to filter its buildings by period of construction. Here's what all of the periods and all of the buildings look like:

Once you play around with the map, it will become obvious that the second half of the 19th century and the early 20th century was a prolific building period for Paris (1231 hectares of area). This is what Samuel was getting at in his tweet.

I would love to see a map like this for every city in the world.

This is an interesting study by Clio Andries (assistant professor at the Georgia Institute of Technology) and Xiaofan Laing (city planning graduate student). It looks at restaurant “chaininess” across the United States.

To do this, they mapped over 800,000 restaurants and looked for, among other things, restaurants with the same name. If the same restaurant name shows up in multiple locations, it is considered to be a chain.

Looking at the above snapshot of San Francisco, a yellow dot represents what is thought to be an independent restaurant and a dark purple/maroon dot represents a chain.

San Francisco has a very high percentage of independent restaurants. In their study, the city receives a chainess score of 28, compared to the national average of 1,247. (Some cities in the southeastern US are in the 1,900s).

One of the interesting takeaways from this study is that there appears to be a correlation between chaininess and built form. Generally speaking, the study revealed that auto-centric communities tend to have more chain restaurants, versus more independent restaurants in pedestrian-centric communities.

This is perhaps intuitive if you’ve ever driven and traveled across the US, but it is interesting to consider what is actually leading to this food and beverage outcome. Density certainly plays a role.

Alasdair Rae is back with another set of interesting maps. This time he maps out precipitation levels across the United Kingdom and the United States using cool 3D extruded mappings. He calls them rain shadow maps. Above is showing the average annual precipitation in the contiguous US from 1981 to 2010. The higher the peaks the higher the precipitation. Not surprisingly, the highest values are in the Pacific Northwest with over 4,064 mm (160 inches) of precipitation per annum. Some of the patterns here are also really interesting. Note California's Central Valley.