Street-network Sprawl in Guigang, 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.

Guigang: 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 Guigang, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Guigang as of 2014, the overall level of street-network sprawl is 2.42, 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 2.54, 2.34, 2.1 and 2.57. The disconnectivity of new streets constructed in Guigang fell, then rose. In 1991-2000, new street layouts were the most connected.

Quantity of street network construction: The street network in Guigang spans a total of 305 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 2.34, 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 2.54, 2.38, 2.35 and 2.42. The SNDi of the aggregate street network in fell at first, but Guigang has worsened in disconnectivity since 2000.

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

How do development practices in Guigang fare in comparison to others in Guangxi? Most recently in 2001-2014, street construction in Guigang was the 21st-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 Guigang has become more connected. Guigang ranked 14th in 1975, 26th in 1976-1990, 17th in 1991-2000 and 21st in 2001-2014.

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

How do development practices in Guigang fare in comparison to others in China? Most recently in 2001-2014, street construction in Guigang was the 492nd-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 Guigang has become more connected. Guigang ranked 345th in 1975, 514th in 1976-1990, 454th in 1991-2000 and 492nd in 2001-2014.

Guigang and Guangxi do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Guigang was at its lowest in 1991-2000, while the SNDi of street constructions in Guangxi peaked in 1976-1990.

To date, Guigang is the 23rd-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 Guigang has become more connected. Guigang ranked 14th in 1975, 25th in 1976-1990, 24th in 1991-2000 and 23rd in 2001-2014.

Guigang and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Guigang was at its lowest in 1991-2000, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Guigang is the 520th-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 Guigang has become more connected. Guigang ranked 345th in 1975, 487th in 1976-1990, 502nd in 1991-2000 and 520th in 2001-2014.

As of 2015, Guigang had a built-up area of 36.72 square kilometers, and a population of 324439 people.

These are some other cities with approximately the same population: