Street-network Sprawl in Puli Khumri, Afghanistan

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.

Puli Khumri: city in Baghlan, Afghanistan

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 Puli Khumri, Afghanistan on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Puli Khumri as of 2014, the overall level of street-network sprawl is 1.21, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.8, nan, nan and 0.63. Data was not available in 1976-1990 and 1991-2000.

Quantity of street network construction: The street network in Puli Khumri spans a total of 21 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 0.63, 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 1.8, 2.7, 2.48 and 1.21. The aggregate street network in Puli Khumri increased in disconnectivity initially,but the trend has turned around after 1990.

Puli Khumri and Baghlan do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, as well as the Baghlan's street network construction.

How do development practices in Puli Khumri fare in comparison to others in Baghlan? Most recently in 2001-2014, street construction in Puli Khumri was the 1st-most disconnected out of the 1 cities in Baghlan. Puli Khumri ranked 1st in 1975 and 1st in 2001-2014. There was no ranking in 1976-1990 and 1991-2000 due to unavailable data.

Puli Khumri and Afghanistan 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 Afghanistan followed a zig-zag trend with an overall decrease.

How do development practices in Puli Khumri fare in comparison to others in Afghanistan? Most recently in 2001-2014, street construction in Puli Khumri was the 26th-most disconnected out of the 40 cities in Afghanistan. Puli Khumri ranked 17th in 1975 and 26th in 2001-2014. There was no ranking in 1976-1990 and 1991-2000 due to unavailable data.

Puli Khumri and Baghlan follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these peaked in 1976-1990.

To date, Puli Khumri is the 1st-most disconnected out of the 1 cities in Baghlan. Its position in the ranks since 1975 has not changed. Puli Khumri ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

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

To date, Puli Khumri is the 31st-most disconnected out of the 40 cities in Afghanistan. Its position in the ranks since 1975 has fallen; relative to other cities in Afghanistan, the street network in Puli Khumri has become more connected. Puli Khumri ranked 17th in 1975, 16th in 1976-1990, 21st in 1991-2000 and 31st in 2001-2014.

As of 2015, Puli Khumri had a built-up area of 1.93 square kilometers, and a population of 214258 people.

These are some other cities with approximately the same population: