Street-network Sprawl in Nurabad, Iran

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.

Nurabad: city in Lorestan, Iran

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 Nurabad, Iran on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Nurabad as of 2014, the overall level of street-network sprawl is 0.92, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -0.44, 0.09, 1.0 and 1.88. In each period, new street development in Nurabad steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Nurabad spans a total of 135 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 1.88, 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 -0.44, 0.02, 0.23 and 0.92. Overall, the SNDi of the aggregate street network has risen: the street network in Nurabad has become more disconnected.

Nurabad and Lorestan do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Nurabad rose steadily, while the SNDi of street constructions in Lorestan was at its lowest in 1976-1990.

How do development practices in Nurabad fare in comparison to others in Lorestan? Most recently in 2001-2014, street construction in Nurabad was the 5th-most disconnected out of the 6 cities in Lorestan. Its position in the ranks since 1975 has not changed. Nurabad ranked 5th in 1975, 6th in 1976-1990, 6th in 1991-2000 and 5th in 2001-2014.

Nurabad and Iran do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Nurabad rose steadily, while the SNDi of street constructions in Iran was at its lowest in 1976-1990.

How do development practices in Nurabad fare in comparison to others in Iran? Most recently in 2001-2014, street construction in Nurabad was the 135th-most disconnected out of the 181 cities in Iran. Its position in the ranks since 1975 has fallen; relative to other cities in Iran, street construction in Nurabad has become more connected. Nurabad ranked 131st in 1975, 168th in 1976-1990, 135th in 1991-2000 and 135th in 2001-2014.

Nurabad and Lorestan do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Nurabad rose steadily, while the SNDi of street constructions in Lorestan was at its lowest in 1976-1990.

To date, Nurabad is the 6th-most disconnected out of the 6 cities in Lorestan. Its position in the ranks since 1975 has fallen; relative to other cities in Lorestan, the street network in Nurabad has become more connected. Nurabad ranked 5th in 1975, 6th in 1976-1990, 6th in 1991-2000 and 6th in 2001-2014.

Nurabad and Iran do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Nurabad rose steadily, while the SNDi of street constructions in Iran was at its lowest in 1976-1990.

To date, Nurabad is the 169th-most disconnected out of the 181 cities in Iran. Its position in the ranks since 1975 has fallen; relative to other cities in Iran, the street network in Nurabad has become more connected. Nurabad ranked 131st in 1975, 171st in 1976-1990, 174th in 1991-2000 and 169th in 2001-2014.

As of 2015, Nurabad had a built-up area of 3.6 square kilometers, and a population of 109255 people.

These are some other cities with approximately the same population: