Street-network Sprawl in Zhangzhou, 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.

Zhangzhou: city in Fujian, 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 Zhangzhou, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Zhangzhou as of 2014, the overall level of street-network sprawl is 2.14, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.95, 2.24, -0.71 and 1.92. Disconnectivity in street construction in Zhangzhou follows a zig-zag trend. In 1991-2000, street construction was most disconnected, while construction was most connected in 1976-1990.

Quantity of street network construction: The street network in Zhangzhou spans a total of 644 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 2.24, which is relatively 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 1.95, 2.17, 2.15 and 2.14. The aggregate street network in Zhangzhou increased in disconnectivity initially,but the trend has turned around after 1990.

Zhangzhou and Fujian do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Zhangzhou followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Fujian peaked in 1991-2000.

How do development practices in Zhangzhou fare in comparison to others in Fujian? Most recently in 2001-2014, street construction in Zhangzhou was the 27th-most disconnected out of the 55 cities in Fujian. Its position in the ranks since 1975 has fallen; relative to other cities in Fujian, street construction in Zhangzhou has become more connected. Zhangzhou ranked 21st in 1975, 26th in 1976-1990, 32nd in 1991-2000 and 27th in 2001-2014.

Zhangzhou 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 decrease.

How do development practices in Zhangzhou fare in comparison to others in China? Most recently in 2001-2014, street construction in Zhangzhou was the 687th-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 Zhangzhou has become more connected. Zhangzhou ranked 513th in 1975, 555th in 1976-1990, 1213th in 1991-2000 and 687th in 2001-2014.

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

To date, Zhangzhou is the 30th-most disconnected out of the 55 cities in Fujian. Its position in the ranks since 1975 has fallen; relative to other cities in Fujian, the street network in Zhangzhou has become more connected. Zhangzhou ranked 21st in 1975, 28th in 1976-1990, 29th in 1991-2000 and 30th in 2001-2014.

Zhangzhou and China follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these peaked in 1976-1990.

To date, Zhangzhou is the 644th-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 Zhangzhou has become more connected. Zhangzhou ranked 513th in 1975, 581st in 1976-1990, 593rd in 1991-2000 and 644th in 2001-2014.

As of 2015, Zhangzhou had a built-up area of 65.84 square kilometers, and a population of 693674 people.

These are some other cities with approximately the same population: