Street-network Sprawl in Dongkou, 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.

Dongkou: 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 Dongkou, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Dongkou as of 2014, the overall level of street-network sprawl is 2.29, 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 1.3, 1.92, 1.78 and 2.7. Disconnectivity in street construction in Dongkou follows a zig-zag trend. In 1975, street construction was most disconnected, while construction was most connected in 2001-2014.

Quantity of street network construction: The street network in Dongkou spans a total of 73 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 2.7, which is in the 40th to 60th percentile of disconnectedness.

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 1.3, 1.62, 1.66 and 2.29. Overall, the SNDi of the aggregate street network has risen: the street network in Dongkou has become more disconnected.

Dongkou and Hunan follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these followed a zig-zag trend with an overall increase.

How do development practices in Dongkou fare in comparison to others in Hunan? Most recently in 2001-2014, street construction in Dongkou was the 26th-most disconnected out of the 95 cities in Hunan. Its position in the ranks since 1975 has risen; relative to other cities in Hunan, street construction in Dongkou has become more disconnected. Dongkou ranked 53rd in 1975, 44th in 1976-1990, 30th in 1991-2000 and 26th in 2001-2014.

Dongkou and China follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these followed a zig-zag trend with an overall increase.

How do development practices in Dongkou fare in comparison to others in China? Most recently in 2001-2014, street construction in Dongkou was the 458th-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 Dongkou has become more disconnected. Dongkou ranked 722nd in 1975, 690th in 1976-1990, 559th in 1991-2000 and 458th in 2001-2014.

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

To date, Dongkou is the 39th-most disconnected out of the 95 cities in Hunan. Its position in the ranks since 1975 has risen; relative to other cities in Hunan, the street network in Dongkou has become more disconnected. Dongkou ranked 53rd in 1975, 56th in 1976-1990, 55th in 1991-2000 and 39th in 2001-2014.

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

To date, Dongkou is the 579th-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 Dongkou has become more disconnected. Dongkou ranked 722nd in 1975, 828th in 1976-1990, 822nd in 1991-2000 and 579th in 2001-2014.

As of 2015, Dongkou had a built-up area of 4.95 square kilometers, and a population of 77387 people.

These are some other cities with approximately the same population: