Street-network Sprawl in 嘉祥县, 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.

嘉祥县: city in Shandong, 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 嘉祥县, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in 嘉祥县 as of 2014, the overall level of street-network sprawl is 0.39, which is very well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.01, 1.05, 0.4 and 0.15. Street construction in 嘉祥县 increased in disconnectivity initially but has since improved. The streets constructed in 1976-1990 were the most disconnected.

Quantity of street network construction: The street network in 嘉祥县 spans a total of 203 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 0.15, which is very 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 0.01, 0.63, 0.52 and 0.39. The aggregate street network in 嘉祥县 increased in disconnectivity initially,but the trend has turned around after 1990.

嘉祥县 and Shandong do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in 嘉祥县 peaked in 1976-1990, while the SNDi of street constructions in Shandong followed a zig-zag trend with an overall increase.

How do development practices in 嘉祥县 fare in comparison to others in Shandong? Most recently in 2001-2014, street construction in 嘉祥县 was the 90th-most disconnected out of the 113 cities in Shandong. Its position in the ranks since 1975 has fallen; relative to other cities in Shandong, street construction in 嘉祥县 has become more connected. 嘉祥县 ranked 63rd in 1975, 50th in 1976-1990, 69th in 1991-2000 and 90th in 2001-2014.

嘉祥县 and China do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in 嘉祥县 peaked 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 嘉祥县 fare in comparison to others in China? Most recently in 2001-2014, street construction in 嘉祥县 was the 1256th-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 嘉祥县 has become more connected. 嘉祥县 ranked 1113th in 1975, 1046th in 1976-1990, 982nd in 1991-2000 and 1256th in 2001-2014.

嘉祥县 and Shandong follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these peaked in 1976-1990.

To date, 嘉祥县 is the 82nd-most disconnected out of the 113 cities in Shandong. Its position in the ranks since 1975 has fallen; relative to other cities in Shandong, the street network in 嘉祥县 has become more connected. 嘉祥县 ranked 63rd in 1975, 70th in 1976-1990, 73rd in 1991-2000 and 82nd in 2001-2014.

嘉祥县 and China follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these peaked in 1976-1990.

To date, 嘉祥县 is the 1452nd-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 嘉祥县 has become more connected. 嘉祥县 ranked 1113th in 1975, 1304th in 1976-1990, 1365th in 1991-2000 and 1452nd in 2001-2014.

As of 2015, 嘉祥县 had a built-up area of 28.93 square kilometers, and a population of 210649 people.

These are some other cities with approximately the same population: