Street-network Sprawl in Yunzhou, 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.

Yunzhou: city in Shanxi, 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 Yunzhou, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Yunzhou as of 2014, the overall level of street-network sprawl is 0.81, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -1.29, -0.17, 0.45 and 2.51. In each period, new street development in Yunzhou steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Yunzhou spans a total of 54 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of -0.17, 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 -1.29, -0.35, 0.09 and 0.81. Overall, the SNDi of the aggregate street network has risen: the street network in Yunzhou has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.94 points, but between 1991-2000 and 2001-2014, it rose by just 0.71.

Yunzhou and Shanxi do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Yunzhou rose steadily, while the SNDi of street constructions in Shanxi peaked in 1976-1990.

How do development practices in Yunzhou fare in comparison to others in Shanxi? Most recently in 2001-2014, street construction in Yunzhou was the 23rd-most disconnected out of the 74 cities in Shanxi. Its position in the ranks since 1975 has risen; relative to other cities in Shanxi, street construction in Yunzhou has become more disconnected. Yunzhou ranked 69th in 1975, 65th in 1976-1990, 35th in 1991-2000 and 23rd in 2001-2014.

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

How do development practices in Yunzhou fare in comparison to others in China? Most recently in 2001-2014, street construction in Yunzhou was the 509th-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 Yunzhou has become more disconnected. Yunzhou ranked 1287th in 1975, 1397th in 1976-1990, 961st in 1991-2000 and 509th in 2001-2014.

Yunzhou and Shanxi follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Yunzhou is the 58th-most disconnected out of the 74 cities in Shanxi. Its position in the ranks since 1975 has risen; relative to other cities in Shanxi, the street network in Yunzhou has become more disconnected. Yunzhou ranked 69th in 1975, 71st in 1976-1990, 67th in 1991-2000 and 58th in 2001-2014.

Yunzhou and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Yunzhou rose steadily, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Yunzhou is the 1311th-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 Yunzhou has become more connected. Yunzhou ranked 1287th in 1975, 1535th in 1976-1990, 1493rd in 1991-2000 and 1311th in 2001-2014.

As of 2015, Yunzhou had a built-up area of 1.44 square kilometers, and a population of 52725 people.

These are some other cities with approximately the same population: