Street-network Sprawl in Wenzhou, 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.

Wenzhou: city in Zhejiang, 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 Wenzhou, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Wenzhou as of 2014, the overall level of street-network sprawl is 2.93, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are 2.92, 2.97, 2.74 and 3.12. Disconnectivity in street construction in Wenzhou follows a zig-zag trend. In 1991-2000, street construction was most disconnected, while construction was most connected in 2001-2014.

Quantity of street network construction: The street network in Wenzhou spans a total of 3081 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 2.92, which is in the 40th to 60th percentile of disconnectedness.

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 2.92, 2.93, 2.93 and 2.93. Disconnectivity in Wenzhou's street network follows a zig-zag trend. In 1975, the city was most disconnected; while it was most connected in 1976-1990.

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

How do development practices in Wenzhou fare in comparison to others in Zhejiang? Most recently in 2001-2014, street construction in Wenzhou was the 19th-most disconnected out of the 94 cities in Zhejiang. Its position in the ranks since 1975 has risen; relative to other cities in Zhejiang, street construction in Wenzhou has become more disconnected. Wenzhou ranked 22nd in 1975, 16th in 1976-1990, 14th in 1991-2000 and 19th in 2001-2014.

Wenzhou 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 Wenzhou fare in comparison to others in China? Most recently in 2001-2014, street construction in Wenzhou was the 356th-most disconnected out of the 1651 cities in China. Its position in the ranks since 1975 has fallen; relative to other cities in China, street construction in Wenzhou has become more connected. Wenzhou ranked 267th in 1975, 319th in 1976-1990, 296th in 1991-2000 and 356th in 2001-2014.

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

To date, Wenzhou is the 17th-most disconnected out of the 94 cities in Zhejiang. Its position in the ranks since 1975 has risen; relative to other cities in Zhejiang, the street network in Wenzhou has become more disconnected. Wenzhou ranked 22nd in 1975, 15th in 1976-1990, 11th in 1991-2000 and 17th in 2001-2014.

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

To date, Wenzhou is the 308th-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 Wenzhou has become more connected. Wenzhou ranked 267th in 1975, 309th in 1976-1990, 291st in 1991-2000 and 308th in 2001-2014.

As of 2015, Wenzhou had a built-up area of 270.0 square kilometers, and a population of 4699633 people.

These are some other cities with approximately the same population: