Street-network Sprawl in Kaiyuan, 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.

Kaiyuan: city in Yunnan, 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 Kaiyuan, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Kaiyuan as of 2014, the overall level of street-network sprawl is 1.69, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 2.11, 2.44, -0.08 and nan. Data was not available in 2001-2014.

Quantity of street network construction: The street network in Kaiyuan spans a total of 107 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 2.11, 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 2.11, 2.18, 1.69 and 1.69. Disconnectivity in Kaiyuan's street network follows a zig-zag trend. In 1991-2000, the city was most disconnected; while it was most connected in 1976-1990.

Kaiyuan and Yunnan 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 Yunnan rose steadily.

How do development practices in Kaiyuan fare in comparison to others in Yunnan? out of the 56 cities in Yunnan. Its position in the ranks since 1975 has fallen; relative to other cities in Yunnan, street construction in Kaiyuan has become more connected. Kaiyuan ranked 13th in 1975, 22nd in 1976-1990 and 33rd in 1991-2000. There was no ranking in 2001-2014 due to unavailable data.

Kaiyuan 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 Kaiyuan fare in comparison to others in China? 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 Kaiyuan has become more connected. Kaiyuan ranked 466th in 1975, 477th in 1976-1990 and 1100th in 1991-2000. There was no ranking in 2001-2014 due to unavailable data.

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

To date, Kaiyuan is the 40th-most disconnected out of the 56 cities in Yunnan. Its position in the ranks since 1975 has fallen; relative to other cities in Yunnan, the street network in Kaiyuan has become more connected. Kaiyuan ranked 13th in 1975, 22nd in 1976-1990, 35th in 1991-2000 and 40th in 2001-2014.

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

To date, Kaiyuan is the 861st-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 Kaiyuan has become more connected. Kaiyuan ranked 466th in 1975, 574th in 1976-1990, 800th in 1991-2000 and 861st in 2001-2014.

As of 2015, Kaiyuan had a built-up area of 13.38 square kilometers, and a population of 133047 people.

These are some other cities with approximately the same population: