Street-network Sprawl in Yicheng, 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.

Yicheng: city in Shanxi, 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 Yicheng, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Yicheng as of 2014, the overall level of street-network sprawl is 1.28, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are nan, 1.51, nan and 1.76. Data was not available in 1975 and 1991-2000.

Quantity of street network construction: The street network in Yicheng spans a total of 53 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 1.51, 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 nan, 1.25, 1.21 and 1.28. Data was not available in 1975.

Yicheng and Shanxi 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 Shanxi peaked in 1976-1990.

How do development practices in Yicheng fare in comparison to others in Shanxi? Most recently in 2001-2014, street construction in Yicheng was the 34th-most disconnected out of the 74 cities in Shanxi. Yicheng ranked 38th in 1976-1990 and 34th in 2001-2014. There was no ranking in 1975 and 1991-2000 due to unavailable data.

Yicheng 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 Yicheng fare in comparison to others in China? Most recently in 2001-2014, street construction in Yicheng was the 759th-most disconnected out of the 1651 cities in China. Yicheng ranked 869th in 1976-1990 and 759th in 2001-2014. There was no ranking in 1975 and 1991-2000 due to unavailable data.

Yicheng and Shanxi 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 Shanxi rose steadily.

To date, Yicheng is the 43rd-most disconnected out of the 74 cities in Shanxi. Its position in the ranks since 1975 has risen; relative to other cities in Shanxi, the street network in Yicheng has become more disconnected. Yicheng ranked 45th in 1976-1990, 45th in 1991-2000 and 43rd in 2001-2014. There was no ranking in 1975 due to unavailable data.

Yicheng 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, Yicheng is the 1074th-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 Yicheng has become more connected. Yicheng ranked 1016th in 1976-1990, 1053rd in 1991-2000 and 1074th in 2001-2014. There was no ranking in 1975 due to unavailable data.

As of 2015, Yicheng had a built-up area of 9.58 square kilometers, and a population of 70275 people.

These are some other cities with approximately the same population: