Street-network Sprawl in Lishui, 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.

Lishui: city in Jiangsu, 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 Lishui, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Lishui as of 2014, the overall level of street-network sprawl is 0.86, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -0.2, -0.44, 0.43 and 1.58. The disconnectivity of new streets constructed in Lishui fell, then rose. In 1976-1990, new street layouts were the most connected.

Quantity of street network construction: The street network in Lishui spans a total of 181 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 1.58, 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 -0.2, -0.32, 0.05 and 0.86. The SNDi of the aggregate street network in fell at first, but Lishui has worsened in disconnectivity since 1990.

Lishui and Jiangsu do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Lishui was at its lowest in 1976-1990, while the SNDi of street constructions in Jiangsu followed a zig-zag trend with an overall increase.

How do development practices in Lishui fare in comparison to others in Jiangsu? Most recently in 2001-2014, street construction in Lishui was the 52nd-most disconnected out of the 87 cities in Jiangsu. Its position in the ranks since 1975 has risen; relative to other cities in Jiangsu, street construction in Lishui has become more disconnected. Lishui ranked 72nd in 1975, 82nd in 1976-1990, 64th in 1991-2000 and 52nd in 2001-2014.

Lishui and China do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Lishui was at its lowest in 1976-1990, while the SNDi of street constructions in China followed a zig-zag trend with an overall decrease.

How do development practices in Lishui fare in comparison to others in China? Most recently in 2001-2014, street construction in Lishui was the 825th-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 Lishui has become more disconnected. Lishui ranked 1157th in 1975, 1429th in 1976-1990, 970th in 1991-2000 and 825th in 2001-2014.

Lishui and Jiangsu do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Lishui was at its lowest in 1976-1990, while the SNDi of street constructions in Jiangsu peaked in 1976-1990.

To date, Lishui is the 71st-most disconnected out of the 87 cities in Jiangsu. Its position in the ranks since 1975 has risen; relative to other cities in Jiangsu, the street network in Lishui has become more disconnected. Lishui ranked 72nd in 1975, 83rd in 1976-1990, 82nd in 1991-2000 and 71st in 2001-2014.

Lishui and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Lishui was at its lowest in 1976-1990, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Lishui is the 1294th-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 Lishui has become more connected. Lishui ranked 1157th in 1975, 1528th in 1976-1990, 1500th in 1991-2000 and 1294th in 2001-2014.

As of 2015, Lishui had a built-up area of 15.12 square kilometers, and a population of 157094 people.

These are some other cities with approximately the same population: