Street-network Sprawl in Shayuan, 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.

Shayuan: city in Guangdong, 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 Shayuan, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Shayuan as of 2014, the overall level of street-network sprawl is 2.52, 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 1.21, 2.56, 2.47 and 4.14. Disconnectivity in street construction in Shayuan 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 Shayuan spans a total of 149 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 2.56, 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 1.21, 2.36, 2.41 and 2.52. Overall, the SNDi of the aggregate street network has risen: the street network in Shayuan has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 1.15 points, but between 1991-2000 and 2001-2014, it rose by just 0.11.

Shayuan and Guangdong do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Shayuan followed a zig-zag trend with an overall increase, while the SNDi of street constructions in Guangdong was at its lowest in 1991-2000.

How do development practices in Shayuan fare in comparison to others in Guangdong? Most recently in 2001-2014, street construction in Shayuan was the 17th-most disconnected out of the 109 cities in Guangdong. Its position in the ranks since 1975 has risen; relative to other cities in Guangdong, street construction in Shayuan has become more disconnected. Shayuan ranked 54th in 1975, 42nd in 1976-1990, 26th in 1991-2000 and 17th in 2001-2014.

Shayuan 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 Shayuan fare in comparison to others in China? Most recently in 2001-2014, street construction in Shayuan was the 177th-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 Shayuan has become more disconnected. Shayuan ranked 746th in 1975, 437th in 1976-1990, 354th in 1991-2000 and 177th in 2001-2014.

Shayuan and Guangdong do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Shayuan rose steadily, while the SNDi of street constructions in Guangdong was at its lowest in 1991-2000.

To date, Shayuan is the 39th-most disconnected out of the 109 cities in Guangdong. Its position in the ranks since 1975 has risen; relative to other cities in Guangdong, the street network in Shayuan has become more disconnected. Shayuan ranked 54th in 1975, 43rd in 1976-1990, 39th in 1991-2000 and 39th in 2001-2014.

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

To date, Shayuan is the 466th-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 Shayuan has become more disconnected. Shayuan ranked 746th in 1975, 498th in 1976-1990, 475th in 1991-2000 and 466th in 2001-2014.

As of 2015, Shayuan had a built-up area of 13.21 square kilometers, and a population of 144053 people.

These are some other cities with approximately the same population: