Street-network Sprawl in Jiawang, 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.

Jiawang: 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 Jiawang, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Jiawang as of 2014, the overall level of street-network sprawl is 1.81, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.76, 0.22, 2.25 and 3.06. The disconnectivity of new streets constructed in Jiawang fell, then rose. In 1976-1990, new street layouts were the most connected.

Quantity of street network construction: The street network in Jiawang spans a total of 134 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 3.06, which is in the 40th to 60th percentile of disconnectedness.

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 1.76, 1.14, 1.53 and 1.81. The SNDi of the aggregate street network in fell at first, but Jiawang has worsened in disconnectivity since 1990.

Jiawang and Jiangsu do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Jiawang was at its lowest in 1976-1990, while the SNDi of street constructions in Jiangsu followed a zig-zag trend with an overall increase.

How do development practices in Jiawang fare in comparison to others in Jiangsu? Most recently in 2001-2014, street construction in Jiawang was the 10th-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 Jiawang has become more disconnected. Jiawang ranked 32nd in 1975, 77th in 1976-1990, 27th in 1991-2000 and 10th in 2001-2014.

Jiawang and China do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Jiawang was at its lowest 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 Jiawang fare in comparison to others in China? Most recently in 2001-2014, street construction in Jiawang was the 366th-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 Jiawang has become more disconnected. Jiawang ranked 569th in 1975, 1317th in 1976-1990, 414th in 1991-2000 and 366th in 2001-2014.

Jiawang and Jiangsu do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Jiawang was at its lowest in 1976-1990, while the SNDi of street constructions in Jiangsu peaked in 1976-1990.

To date, Jiawang is the 36th-most disconnected out of the 87 cities in Jiangsu. Its position in the ranks since 1975 has fallen; relative to other cities in Jiangsu, the street network in Jiawang has become more connected. Jiawang ranked 32nd in 1975, 57th in 1976-1990, 46th in 1991-2000 and 36th in 2001-2014.

Jiawang and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Jiawang was at its lowest in 1976-1990, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Jiawang is the 795th-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 Jiawang has become more connected. Jiawang ranked 569th in 1975, 1067th in 1976-1990, 885th in 1991-2000 and 795th in 2001-2014.

As of 2015, Jiawang had a built-up area of 24.87 square kilometers, and a population of 92879 people.

These are some other cities with approximately the same population: