Street-network Sprawl in Dingyuan, 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.

Dingyuan: city in Anhui, 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 Dingyuan, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Dingyuan as of 2014, the overall level of street-network sprawl is 1.78, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.38, 2.21, 2.11 and 1.41. Street construction in Dingyuan increased in disconnectivity initially but has since improved. The streets constructed in 1976-1990 were the most disconnected.

Quantity of street network construction: The street network in Dingyuan spans a total of 149 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 1.41, 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 1.38, 2.1, 2.09 and 1.78. The aggregate street network in Dingyuan increased in disconnectivity initially,but the trend has turned around after 1990.

Dingyuan and Anhui do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Dingyuan peaked in 1976-1990, while the SNDi of street constructions in Anhui fell steadily.

How do development practices in Dingyuan fare in comparison to others in Anhui? Most recently in 2001-2014, street construction in Dingyuan was the 25th-most disconnected out of the 65 cities in Anhui. Its position in the ranks since 1975 has fallen; relative to other cities in Anhui, street construction in Dingyuan has become more connected. Dingyuan ranked 20th in 1975, 16th in 1976-1990, 9th in 1991-2000 and 25th in 2001-2014.

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

How do development practices in Dingyuan fare in comparison to others in China? Most recently in 2001-2014, street construction in Dingyuan was the 883rd-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 Dingyuan has become more connected. Dingyuan ranked 699th in 1975, 570th in 1976-1990, 449th in 1991-2000 and 883rd in 2001-2014.

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

To date, Dingyuan is the 16th-most disconnected out of the 65 cities in Anhui. Its position in the ranks since 1975 has risen; relative to other cities in Anhui, the street network in Dingyuan has become more disconnected. Dingyuan ranked 20th in 1975, 14th in 1976-1990, 13th in 1991-2000 and 16th in 2001-2014.

Dingyuan 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, Dingyuan is the 814th-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 Dingyuan has become more connected. Dingyuan ranked 699th in 1975, 617th in 1976-1990, 613th in 1991-2000 and 814th in 2001-2014.

As of 2015, Dingyuan had a built-up area of 16.8 square kilometers, and a population of 108206 people.

These are some other cities with approximately the same population: