Street-network Sprawl in Changzhi, 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.

Changzhi: 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 Changzhi, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Changzhi as of 2014, the overall level of street-network sprawl is 1.02, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.61, 1.33, 1.66 and 1.76. In each period, new street development in Changzhi steadily grows more disconnected than in the last. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.72 points, but between 1991-2000 and 2001-2014, it rose by just 0.1.

Quantity of street network construction: The street network in Changzhi spans a total of 492 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 1.33, 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 0.61, 0.96, 0.97 and 1.02. Overall, the SNDi of the aggregate street network has risen: the street network in Changzhi has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.35 points, but between 1991-2000 and 2001-2014, it rose by just 0.05.

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

How do development practices in Changzhi fare in comparison to others in Shanxi? Most recently in 2001-2014, street construction in Changzhi was the 33rd-most disconnected out of the 74 cities in Shanxi. Its position in the ranks since 1975 has risen; relative to other cities in Shanxi, street construction in Changzhi has become more disconnected. Changzhi ranked 44th in 1975, 46th in 1976-1990, 22nd in 1991-2000 and 33rd in 2001-2014.

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

How do development practices in Changzhi fare in comparison to others in China? Most recently in 2001-2014, street construction in Changzhi was the 755th-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 Changzhi has become more disconnected. Changzhi ranked 951st in 1975, 945th in 1976-1990, 587th in 1991-2000 and 755th in 2001-2014.

Changzhi and Shanxi follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Changzhi is the 52nd-most disconnected out of the 74 cities in Shanxi. Its position in the ranks since 1975 has fallen; relative to other cities in Shanxi, the street network in Changzhi has become more connected. Changzhi ranked 44th in 1975, 50th in 1976-1990, 50th in 1991-2000 and 52nd in 2001-2014.

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

To date, Changzhi is the 1209th-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 Changzhi has become more connected. Changzhi ranked 951st in 1975, 1146th in 1976-1990, 1165th in 1991-2000 and 1209th in 2001-2014.

As of 2015, Changzhi had a built-up area of 58.69 square kilometers, and a population of 573666 people.

These are some other cities with approximately the same population:

For some related information about population, urban extent and density, and roads, visit the Atlas of Urban Expansion.