Street-network Sprawl in Bagh-e Zahra, 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.

Bagh-e Zahra: city in Bushehr, 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 Bagh-e Zahra, Iran on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Bagh-e Zahra as of 2014, the overall level of street-network sprawl is 0.69, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are nan, 0.63, nan and nan. Data was not available in 1975, 1991-2000 and 2001-2014.

Quantity of street network construction: The street network in Bagh-e Zahra spans a total of 292 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of nan, which is highly disconnected.

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 nan, 0.63, 0.63 and 0.69. Data was not available in 1975.

Bagh-e Zahra and Bushehr 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 Bushehr was at its lowest in 1976-1990.

How do development practices in Bagh-e Zahra fare in comparison to others in Bushehr? out of the 5 cities in Bushehr. Bagh-e Zahra ranked 4th in 1976-1990. There was no ranking in 1975, 1991-2000, and 2001-2014 due to unavailable data.

Bagh-e Zahra and Iran 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 Iran was at its lowest in 1976-1990.

How do development practices in Bagh-e Zahra fare in comparison to others in Iran? out of the 181 cities in Iran. Bagh-e Zahra ranked 151st in 1976-1990. There was no ranking in 1975, 1991-2000, and 2001-2014 due to unavailable data.

Bagh-e Zahra and Bushehr do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Bushehr was at its lowest in 1976-1990.

To date, Bagh-e Zahra is the 4th-most disconnected out of the 5 cities in Bushehr. Its position in the ranks since 1975 has fallen; relative to other cities in Bushehr, the street network in Bagh-e Zahra has become more connected. Bagh-e Zahra ranked 3rd in 1976-1990, 3rd in 1991-2000 and 4th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Bagh-e Zahra and Iran do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Iran was at its lowest in 1976-1990.

To date, Bagh-e Zahra is the 176th-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 Bagh-e Zahra has become more connected. Bagh-e Zahra ranked 155th in 1976-1990, 164th in 1991-2000 and 176th in 2001-2014. There was no ranking in 1975 due to unavailable data.

As of 2015, Bagh-e Zahra had a built-up area of 10.7 square kilometers, and a population of 114945 people.

These are some other cities with approximately the same population: