Street-network Sprawl in Qiandeng, 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.

Qiandeng: city in Jiangsu, 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 Qiandeng, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Qiandeng as of 2014, the overall level of street-network sprawl is 1.72, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are nan, 0.85, 0.25 and 1.96. Data was not available in 1975.

Quantity of street network construction: The street network in Qiandeng spans a total of 155 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of nan, which is highly disconnected.

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 nan, 0.85, 0.45 and 1.72. Data was not available in 1975.

Qiandeng and Jiangsu do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Jiangsu followed a zig-zag trend with an overall increase.

How do development practices in Qiandeng fare in comparison to others in Jiangsu? Most recently in 2001-2014, street construction in Qiandeng was the 39th-most disconnected out of the 87 cities in Jiangsu. Its position in the ranks since 1975 has risen; relative to other cities in Jiangsu, street construction in Qiandeng has become more disconnected. Qiandeng ranked 62nd in 1976-1990, 71st in 1991-2000 and 39th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Qiandeng and China do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in China followed a zig-zag trend with an overall decrease.

How do development practices in Qiandeng fare in comparison to others in China? Most recently in 2001-2014, street construction in Qiandeng was the 678th-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 Qiandeng has become more disconnected. Qiandeng ranked 1114th in 1976-1990, 1023rd in 1991-2000 and 678th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Qiandeng and Jiangsu do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Jiangsu peaked in 1976-1990.

To date, Qiandeng is the 40th-most disconnected out of the 87 cities in Jiangsu. Its position in the ranks since 1975 has risen; relative to other cities in Jiangsu, the street network in Qiandeng has become more disconnected. Qiandeng ranked 68th in 1976-1990, 70th in 1991-2000 and 40th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Qiandeng and China do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Qiandeng is the 843rd-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 Qiandeng has become more disconnected. Qiandeng ranked 1207th in 1976-1990, 1386th in 1991-2000 and 843rd in 2001-2014. There was no ranking in 1975 due to unavailable data.

As of 2015, Qiandeng had a built-up area of 20.09 square kilometers, and a population of 63703 people.

These are some other cities with approximately the same population: