Street-network Sprawl in Yongcheng, 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.

Yongcheng: city in Henan, 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 Yongcheng, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Yongcheng as of 2014, the overall level of street-network sprawl is 1.33, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -0.25, -0.26, 2.48 and 0.85. Disconnectivity in street construction in Yongcheng follows a zig-zag trend. In 1976-1990, street construction was most disconnected, while construction was most connected in 1991-2000.

Quantity of street network construction: The street network in Yongcheng spans a total of 244 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 0.85, 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 -0.25, -0.27, 1.58 and 1.33. Disconnectivity in Yongcheng's street network follows a zig-zag trend. In 1976-1990, the city was most disconnected; while it was most connected in 1991-2000.

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

How do development practices in Yongcheng fare in comparison to others in Henan? Most recently in 2001-2014, street construction in Yongcheng was the 56th-most disconnected out of the 118 cities in Henan. Its position in the ranks since 1975 has risen; relative to other cities in Henan, street construction in Yongcheng has become more disconnected. Yongcheng ranked 57th in 1975, 103rd in 1976-1990, 17th in 1991-2000 and 56th in 2001-2014.

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

How do development practices in Yongcheng fare in comparison to others in China? Most recently in 2001-2014, street construction in Yongcheng was the 1057th-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 Yongcheng has become more disconnected. Yongcheng ranked 1167th in 1975, 1409th in 1976-1990, 352nd in 1991-2000 and 1057th in 2001-2014.

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

To date, Yongcheng is the 38th-most disconnected out of the 118 cities in Henan. Its position in the ranks since 1975 has risen; relative to other cities in Henan, the street network in Yongcheng has become more disconnected. Yongcheng ranked 57th in 1975, 105th in 1976-1990, 30th in 1991-2000 and 38th in 2001-2014.

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

To date, Yongcheng is the 1047th-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 Yongcheng has become more disconnected. Yongcheng ranked 1167th in 1975, 1520th in 1976-1990, 859th in 1991-2000 and 1047th in 2001-2014.

As of 2015, Yongcheng had a built-up area of 36.22 square kilometers, and a population of 200000 people.

These are some other cities with approximately the same population: