Street-network Sprawl in 中塘镇, 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.

中塘镇: city in Tianjin, 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 中塘镇, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in 中塘镇 as of 2014, the overall level of street-network sprawl is 1.45, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 4.57, 1.32, 2.23 and 0.82. Disconnectivity in street construction in 中塘镇 follows a zig-zag trend. In 2001-2014, street construction was most disconnected, while construction was most connected in 1975.

Quantity of street network construction: The street network in 中塘镇 spans a total of 466 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 1.32, 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 4.57, 1.55, 1.72 and 1.45. Disconnectivity in 中塘镇's street network follows a zig-zag trend. In 2001-2014, the city was most disconnected; while it was most connected in 1975.

中塘镇 and Tianjin do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in 中塘镇 followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Tianjin peaked in 1991-2000.

How do development practices in 中塘镇 fare in comparison to others in Tianjin? Most recently in 2001-2014, street construction in 中塘镇 was the 10th-most disconnected out of the 14 cities in Tianjin. Its position in the ranks since 1975 has fallen; relative to other cities in Tianjin, street construction in 中塘镇 has become more connected. 中塘镇 ranked 1st in 1975, 10th in 1976-1990, 7th in 1991-2000 and 10th in 2001-2014.

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

How do development practices in 中塘镇 fare in comparison to others in China? Most recently in 2001-2014, street construction in 中塘镇 was the 1070th-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 中塘镇 has become more connected. 中塘镇 ranked 73rd in 1975, 950th in 1976-1990, 421st in 1991-2000 and 1070th in 2001-2014.

中塘镇 and Tianjin do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in 中塘镇 followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Tianjin rose steadily.

To date, 中塘镇 is the 10th-most disconnected out of the 14 cities in Tianjin. Its position in the ranks since 1975 has fallen; relative to other cities in Tianjin, the street network in 中塘镇 has become more connected. 中塘镇 ranked 1st in 1975, 10th in 1976-1990, 9th in 1991-2000 and 10th in 2001-2014.

中塘镇 and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in 中塘镇 followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in China peaked in 1976-1990.

To date, 中塘镇 is the 984th-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 中塘镇 has become more connected. 中塘镇 ranked 73rd in 1975, 864th in 1976-1990, 784th in 1991-2000 and 984th in 2001-2014.

As of 2015, 中塘镇 had a built-up area of 28.37 square kilometers, and a population of 403677 people.

These are some other cities with approximately the same population: