Street-network Sprawl in Hechi, 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.

Hechi: city in Guangxi, 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 Hechi, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Hechi as of 2014, the overall level of street-network sprawl is 1.52, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.23, 1.27, 2.65 and nan. Data was not available in 2001-2014.

Quantity of street network construction: The street network in Hechi spans a total of 75 kilometers. The period with the greatest volume of street construction was 1991-2000. These roads have an SNDi of 2.65, 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 0.23, 0.64, 1.47 and 1.52. Overall, the SNDi of the aggregate street network has risen: the street network in Hechi has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.41 points, but between 1991-2000 and 2001-2014, it rose by just 0.05.

Hechi and Guangxi 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 Guangxi followed a zig-zag trend with an overall increase.

How do development practices in Hechi fare in comparison to others in Guangxi? out of the 53 cities in Guangxi. Its position in the ranks since 1975 has risen; relative to other cities in Guangxi, street construction in Hechi has become more disconnected. Hechi ranked 30th in 1975, 37th in 1976-1990 and 13th in 1991-2000. There was no ranking in 2001-2014 due to unavailable data.

Hechi 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 Hechi fare in comparison to others in China? 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 Hechi has become more disconnected. Hechi ranked 1065th in 1975, 972nd in 1976-1990 and 321st in 1991-2000. There was no ranking in 2001-2014 due to unavailable data.

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

To date, Hechi is the 35th-most disconnected out of the 53 cities in Guangxi. Its position in the ranks since 1975 has fallen; relative to other cities in Guangxi, the street network in Hechi has become more connected. Hechi ranked 30th in 1975, 45th in 1976-1990, 33rd in 1991-2000 and 35th in 2001-2014.

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

To date, Hechi is the 951st-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 Hechi has become more disconnected. Hechi ranked 1065th in 1975, 1297th in 1976-1990, 918th in 1991-2000 and 951st in 2001-2014.

As of 2015, Hechi had a built-up area of 7.89 square kilometers, and a population of 73937 people.

These are some other cities with approximately the same population: