Street-network Sprawl in Lingao, 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.

Lingao: city in Hainan, 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 Lingao, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Lingao as of 2014, the overall level of street-network sprawl is 2.7, 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 1.58, nan, nan and 4.49. Data was not available in 1976-1990 and 1991-2000.

Quantity of street network construction: The street network in Lingao spans a total of 64 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 1.58, 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 1.58, 1.58, 1.63 and 2.7. Overall, the SNDi of the aggregate street network has risen: the street network in Lingao has become more disconnected.

Lingao and Hainan 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 Hainan followed a zig-zag trend with an overall decrease.

How do development practices in Lingao fare in comparison to others in Hainan? Most recently in 2001-2014, street construction in Lingao was the 3rd-most disconnected out of the 16 cities in Hainan. Lingao ranked 12th in 1975 and 3rd in 2001-2014. There was no ranking in 1976-1990 and 1991-2000 due to unavailable data.

Lingao 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 Lingao fare in comparison to others in China? Most recently in 2001-2014, street construction in Lingao was the 140th-most disconnected out of the 1651 cities in China. Lingao ranked 633rd in 1975 and 140th in 2001-2014. There was no ranking in 1976-1990 and 1991-2000 due to unavailable data.

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

To date, Lingao is the 12th-most disconnected out of the 16 cities in Hainan. Its position in the ranks since 1975 has not changed. Lingao ranked 12th in 1975, 13th in 1976-1990, 14th in 1991-2000 and 12th in 2001-2014.

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

To date, Lingao is the 403rd-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 Lingao has become more disconnected. Lingao ranked 633rd in 1975, 842nd in 1976-1990, 833rd in 1991-2000 and 403rd in 2001-2014.

As of 2015, Lingao had a built-up area of 5.89 square kilometers, and a population of 79913 people.

These are some other cities with approximately the same population: