Street-network Sprawl in Fangcheng, China

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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:

• nodal degree
• dendricity, the tree-likeness of the street network
• circuity, the ratio of the distance by road to the straight-line distance of two locations on the street network
• sinuosity, the curviness of a street

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:

• Global trends toward urban street-network sprawl
• A global assessment of street-network sprawl

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

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Fangcheng: city in Guangxi, 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 Fangcheng, China on the sprawlmap

How have Fangcheng's street networks changed over time?

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Fangcheng as of 2014, the overall level of street-network sprawl is 1.56, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 2.39, 1.26, 2.34 and -0.0. Disconnectivity in street construction in Fangcheng follows a zig-zag trend. In 2001-2014, street construction was most disconnected, while construction was most connected in 1975.

Quantity of street network construction: The street network in Fangcheng spans a total of 120 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of -0.0, 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 2.39, 1.47, 1.66 and 1.56. Disconnectivity in Fangcheng's street network follows a zig-zag trend. In 1976-1990, the city was most disconnected; while it was most connected in 1975.

Fangcheng in context: Street-network sprawl of new development

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

How do development practices in Fangcheng fare in comparison to others in Guangxi? Most recently in 2001-2014, street construction in Fangcheng was the 36th-most disconnected out of the 53 cities in Guangxi. Its position in the ranks since 1975 has fallen; relative to other cities in Guangxi, street construction in Fangcheng has become more connected. Fangcheng ranked 18th in 1975, 38th in 1976-1990, 16th in 1991-2000 and 36th in 2001-2014.

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

Fangcheng in context: Aggregate street-network sprawl

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

To date, Fangcheng is the 34th-most disconnected out of the 53 cities in Guangxi. Its position in the ranks since 1975 has fallen; relative to other cities in Guangxi, the street network in Fangcheng has become more connected. Fangcheng ranked 18th in 1975, 32nd in 1976-1990, 29th in 1991-2000 and 34th in 2001-2014.

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

What about other similarly-populated cities?

As of 2015, Fangcheng had a built-up area of 7.64 square kilometers, and a population of 107514 people.

These are some other cities with approximately the same population:

• Tandil, Argentina
• Birigui, Brazil
• Nangalwadi Phata, India