Street-network Sprawl in Shaoyang, 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.

Shaoyang: city in Hunan, 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 Shaoyang, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Shaoyang as of 2014, the overall level of street-network sprawl is 2.12, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 3.03, 1.91, 1.11 and 1.46. The disconnectivity of new streets constructed in Shaoyang fell, then rose. In 1991-2000, new street layouts were the most connected.

Quantity of street network construction: The street network in Shaoyang spans a total of 380 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 1.46, 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 3.03, 2.79, 2.37 and 2.12. Overall, the SNDi of the aggregate street network has fallen: the street network in Shaoyang has become more connected. This decrease has quickened: between 1975 and 1976-1990, SNDi fell by 0.25 points, but between 1991-2000 and 2001-2014, it fell by just 0.25.

Shaoyang and Hunan do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Shaoyang was at its lowest in 1991-2000, while the SNDi of street constructions in Hunan followed a zig-zag trend with an overall decrease.

How do development practices in Shaoyang fare in comparison to others in Hunan? Most recently in 2001-2014, street construction in Shaoyang was the 51st-most disconnected out of the 95 cities in Hunan. Its position in the ranks since 1975 has fallen; relative to other cities in Hunan, street construction in Shaoyang has become more connected. Shaoyang ranked 19th in 1975, 45th in 1976-1990, 41st in 1991-2000 and 51st in 2001-2014.

Shaoyang and China do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Shaoyang was at its lowest in 1991-2000, while the SNDi of street constructions in China followed a zig-zag trend with an overall decrease.

How do development practices in Shaoyang fare in comparison to others in China? Most recently in 2001-2014, street construction in Shaoyang was the 872nd-most disconnected 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 Shaoyang has become more connected. Shaoyang ranked 238th in 1975, 695th in 1976-1990, 747th in 1991-2000 and 872nd in 2001-2014.

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

To date, Shaoyang is the 46th-most disconnected out of the 95 cities in Hunan. Its position in the ranks since 1975 has fallen; relative to other cities in Hunan, the street network in Shaoyang has become more connected. Shaoyang ranked 19th in 1975, 29th in 1976-1990, 38th in 1991-2000 and 46th in 2001-2014.

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

To date, Shaoyang is the 654th-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 Shaoyang has become more connected. Shaoyang ranked 238th in 1975, 353rd in 1976-1990, 489th in 1991-2000 and 654th in 2001-2014.

As of 2015, Shaoyang had a built-up area of 28.78 square kilometers, and a population of 556216 people.

These are some other cities with approximately the same population: