Street-network Sprawl in Yuxi, 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.

Yuxi: 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 Yuxi, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Yuxi as of 2014, the overall level of street-network sprawl is 2.46, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.92, 3.73, 6.41 and 6.54. In each period, new street development in Yuxi steadily grows more disconnected than in the last. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 1.8 points, but between 1991-2000 and 2001-2014, it rose by just 0.14.

Quantity of street network construction: The street network in Yuxi spans a total of 466 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 1.92, 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 1.92, 2.01, 2.33 and 2.46. Overall, the SNDi of the aggregate street network has risen: the street network in Yuxi has become more disconnected.

Yuxi and Yunnan follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these rose steadily.

How do development practices in Yuxi fare in comparison to others in Yunnan? Most recently in 2001-2014, street construction in Yuxi was the 6th-most disconnected out of the 56 cities in Yunnan. Its position in the ranks since 1975 has risen; relative to other cities in Yunnan, street construction in Yuxi has become more disconnected. Yuxi ranked 18th in 1975, 10th in 1976-1990, 3rd in 1991-2000 and 6th in 2001-2014.

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

How do development practices in Yuxi fare in comparison to others in China? Most recently in 2001-2014, street construction in Yuxi was the 36th-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 Yuxi has become more disconnected. Yuxi ranked 522nd in 1975, 173rd in 1976-1990, 25th in 1991-2000 and 36th in 2001-2014.

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

To date, Yuxi is the 23rd-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 Yuxi has become more connected. Yuxi ranked 18th in 1975, 29th in 1976-1990, 23rd in 1991-2000 and 23rd in 2001-2014.

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

To date, Yuxi is the 493rd-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 Yuxi has become more disconnected. Yuxi ranked 522nd in 1975, 660th in 1976-1990, 514th in 1991-2000 and 493rd in 2001-2014.

As of 2015, Yuxi had a built-up area of 36.31 square kilometers, and a population of 370446 people.

These are some other cities with approximately the same population: