Street-network Sprawl in Zhushan, 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.

Zhushan: city in Hubei, 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 Zhushan, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Zhushan as of 2014, the overall level of street-network sprawl is 2.16, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.12, nan, 2.41 and 5.77. Data was not available in 1976-1990.

Quantity of street network construction: The street network in Zhushan spans a total of 79 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 5.77, which is highly disconnected.

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 1.12, 0.89, 1.5 and 2.16. The SNDi of the aggregate street network in fell at first, but Zhushan has worsened in disconnectivity since 1990.

Zhushan and Hubei do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Hubei peaked in 1976-1990.

How do development practices in Zhushan fare in comparison to others in Hubei? Most recently in 2001-2014, street construction in Zhushan was the 4th-most disconnected out of the 80 cities in Hubei. Its position in the ranks since 1975 has risen; relative to other cities in Hubei, street construction in Zhushan has become more disconnected. Zhushan ranked 33rd in 1975, 26th in 1991-2000 and 4th in 2001-2014. There was no ranking in 1976-1990 due to unavailable data.

Zhushan and China do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in China followed a zig-zag trend with an overall decrease.

How do development practices in Zhushan fare in comparison to others in China? Most recently in 2001-2014, street construction in Zhushan was the 57th-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 Zhushan has become more disconnected. Zhushan ranked 780th in 1975, 375th in 1991-2000 and 57th in 2001-2014. There was no ranking in 1976-1990 due to unavailable data.

Zhushan and Hubei do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Zhushan was at its lowest in 1976-1990, while the SNDi of street constructions in Hubei peaked in 1976-1990.

To date, Zhushan is the 34th-most disconnected out of the 80 cities in Hubei. Its position in the ranks since 1975 has fallen; relative to other cities in Hubei, the street network in Zhushan has become more connected. Zhushan ranked 33rd in 1975, 60th in 1976-1990, 49th in 1991-2000 and 34th in 2001-2014.

Zhushan and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Zhushan was at its lowest in 1976-1990, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Zhushan is the 631st-most disconnected out of the 1651 cities in China. Its position in the ranks since 1975 has risen; relative to other cities in China, the street network in Zhushan has become more disconnected. Zhushan ranked 780th in 1975, 1186th in 1976-1990, 901st in 1991-2000 and 631st in 2001-2014.

As of 2015, Zhushan had a built-up area of 3.38 square kilometers, and a population of 59646 people.

These are some other cities with approximately the same population: