Street-network Sprawl in Dengfeng, 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.

Dengfeng: 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 Dengfeng, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Dengfeng as of 2014, the overall level of street-network sprawl is -0.63, which is very well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -1.22, -0.76, -1.16 and 0.41. Disconnectivity in street construction in Dengfeng 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 Dengfeng spans a total of 134 kilometers. The period with the greatest volume of street construction was 1991-2000. These roads have an SNDi of -1.16, 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 -1.22, -0.81, -0.94 and -0.63. Disconnectivity in Dengfeng's street network follows a zig-zag trend. In 1975, the city was most disconnected; while it was most connected in 2001-2014.

Dengfeng and Henan do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Dengfeng 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 Dengfeng fare in comparison to others in Henan? Most recently in 2001-2014, street construction in Dengfeng was the 75th-most disconnected out of the 118 cities in Henan. Its position in the ranks since 1975 has fallen; relative to other cities in Henan, street construction in Dengfeng has become more connected. Dengfeng ranked 72nd in 1975, 111th in 1976-1990, 98th in 1991-2000 and 75th in 2001-2014.

Dengfeng 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 Dengfeng fare in comparison to others in China? Most recently in 2001-2014, street construction in Dengfeng was the 1196th-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 Dengfeng has become more disconnected. Dengfeng ranked 1283rd in 1975, 1456th in 1976-1990, 1260th in 1991-2000 and 1196th in 2001-2014.

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

To date, Dengfeng is the 116th-most disconnected out of the 118 cities in Henan. Its position in the ranks since 1975 has fallen; relative to other cities in Henan, the street network in Dengfeng has become more connected. Dengfeng ranked 72nd in 1975, 114th in 1976-1990, 116th in 1991-2000 and 116th in 2001-2014.

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

To date, Dengfeng is the 1629th-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 Dengfeng has become more connected. Dengfeng ranked 1283rd in 1975, 1574th in 1976-1990, 1611th in 1991-2000 and 1629th in 2001-2014.

As of 2015, Dengfeng had a built-up area of 11.75 square kilometers, and a population of 121844 people.

These are some other cities with approximately the same population: