Street-network Sprawl in Ningbo, 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.

Ningbo: city in Zhejiang, 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 Ningbo, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Ningbo 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 1.94, 2.44, 2.45 and 2.23. Street construction in Ningbo increased in disconnectivity initially but has since improved. The streets constructed in 1991-2000 were the most disconnected.

Quantity of street network construction: The street network in Ningbo spans a total of 3568 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 2.23, 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 1.94, 2.34, 2.35 and 2.29. The aggregate street network in Ningbo increased in disconnectivity initially,but the trend has turned around after 2000.

Ningbo and Zhejiang do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Ningbo peaked in 1991-2000, while the SNDi of street constructions in Zhejiang peaked in 1976-1990.

How do development practices in Ningbo fare in comparison to others in Zhejiang? Most recently in 2001-2014, street construction in Ningbo was the 36th-most disconnected out of the 94 cities in Zhejiang. Its position in the ranks since 1975 has not changed. Ningbo ranked 36th in 1975, 31st in 1976-1990, 20th in 1991-2000 and 36th in 2001-2014.

Ningbo and China do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Ningbo peaked 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 Ningbo fare in comparison to others in China? Most recently in 2001-2014, street construction in Ningbo was the 584th-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 Ningbo has become more connected. Ningbo ranked 516th in 1975, 475th in 1976-1990, 362nd in 1991-2000 and 584th in 2001-2014.

Ningbo and Zhejiang do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Ningbo peaked in 1991-2000, while the SNDi of street constructions in Zhejiang peaked in 1976-1990.

To date, Ningbo is the 34th-most disconnected out of the 94 cities in Zhejiang. Its position in the ranks since 1975 has risen; relative to other cities in Zhejiang, the street network in Ningbo has become more disconnected. Ningbo ranked 36th in 1975, 33rd in 1976-1990, 25th in 1991-2000 and 34th in 2001-2014.

Ningbo and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Ningbo peaked in 1991-2000, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Ningbo is the 576th-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 Ningbo has become more connected. Ningbo ranked 516th in 1975, 518th in 1976-1990, 500th in 1991-2000 and 576th in 2001-2014.

As of 2015, Ningbo had a built-up area of 250.04 square kilometers, and a population of 2650538 people.

These are some other cities with approximately the same population: