Street-network Sprawl in Miyun, China

What is Street-network sprawl?

Street-network Sprawl is a way to measure urban sprawl, worldwide, through the connectedness of the streets. Less sprawl means more connected, more walkable streets. Well-connected streets – like New York City’s grid – are more walkable and can be served by public transit.

The street network is permanent, and its connectivity affects the livability and environmental footprint of cities for decades and centuries to come. In places with more connected streets, residents drive less and walk more. A well-connected street network is associated with better outcomes for health, the environment, sustainable consumption, social integration, and equity.

We can quantify how connected street networks are with the Street Network Disconnectedness Index (SNDi).

SNDi -- our measure of street-network sprawl (disconnectedness)

The SNDi is a comprehensive measurement of “sprawl”. It captures:

A higher SNDi means less-connected streets – i.e., more sprawl. For the 10137 cities in our dataset, the average SNDi is 2.25, with half of the cities' SNDis falling between 1.08 and 3.25.

More information on the sprawl index can be found in these research papers:

To see the state of street-network sprawl across the globe, visit the sprawlmap.

Miyun: city in Beijing, China

What exactly constitutes the spatial extent of the city? For these aggregations, we used the Global Human Settlement Layer Urban Center Database (GHS-UCDB) to define the boundaries of the city. These cities -- or urban centers -- cover areas that are densely populated and built-up, and so may extend beyond the spatial borders of these cities that we may be familiar with. The GHS area is shaded in blue.

View Miyun, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Miyun as of 2014, the overall level of street-network sprawl is 0.66, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.07, 1.28, 0.29 and 2.17. Disconnectivity in street construction in Miyun follows a zig-zag trend. In 1975, street construction was most disconnected, while construction was most connected in 2001-2014.

Quantity of street network construction: The street network in Miyun spans a total of 189 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 0.07, which is very well-connected.

Effect on the aggregate network: New construction in each period adds to the total stock of streets, but does not change streets that have already been built. Therefore, it has a limited effect on the street network as a whole. The SNDis of the aggregate street network in the respective time periods are 0.07, 0.57, 0.52 and 0.66. Disconnectivity in Miyun's street network follows a zig-zag trend. In 1975, the city was most disconnected; while it was most connected in 2001-2014.

Miyun and Beijing do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Miyun followed a zig-zag trend with an overall increase, while the SNDi of street constructions in Beijing rose steadily.

How do development practices in Miyun fare in comparison to others in Beijing? Most recently in 2001-2014, street construction in Miyun was the 7th-most disconnected out of the 9 cities in Beijing. Its position in the ranks since 1975 has risen; relative to other cities in Beijing, street construction in Miyun has become more disconnected. Miyun ranked 9th in 1975, 8th in 1976-1990, 8th in 1991-2000 and 7th in 2001-2014.

Miyun and China follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these followed a zig-zag trend with an overall increase.

How do development practices in Miyun fare in comparison to others in China? Most recently in 2001-2014, street construction in Miyun was the 617th-most disconnected out of the 1651 cities in China. Its position in the ranks since 1975 has risen; relative to other cities in China, street construction in Miyun has become more disconnected. Miyun ranked 1100th in 1975, 965th in 1976-1990, 1015th in 1991-2000 and 617th in 2001-2014.

Miyun and Beijing do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Miyun followed a zig-zag trend with an overall increase, while the SNDi of street constructions in Beijing rose steadily.

To date, Miyun is the 8th-most disconnected out of the 9 cities in Beijing. Its position in the ranks since 1975 has risen; relative to other cities in Beijing, the street network in Miyun has become more disconnected. Miyun ranked 9th in 1975, 8th in 1976-1990, 8th in 1991-2000 and 8th in 2001-2014.

Miyun and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Miyun followed a zig-zag trend with an overall increase, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Miyun is the 1380th-most disconnected out of the 1651 cities in China. Its position in the ranks since 1975 has fallen; relative to other cities in China, the street network in Miyun has become more connected. Miyun ranked 1100th in 1975, 1319th in 1976-1990, 1366th in 1991-2000 and 1380th in 2001-2014.

As of 2015, Miyun had a built-up area of 21.67 square kilometers, and a population of 222356 people.

These are some other cities with approximately the same population: