Street-network Sprawl in Bagerhat, Bangladesh

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.

Bagerhat: city in Khulna, Bangladesh

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 Bagerhat, Bangladesh on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Bagerhat as of 2014, the overall level of street-network sprawl is 1.24, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -0.47, 0.4, 1.83 and 2.85. In each period, new street development in Bagerhat steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Bagerhat spans a total of 149 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 2.85, which is in the 40th to 60th percentile of disconnectedness.

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 -0.47, 0.1, 0.37 and 1.24. Overall, the SNDi of the aggregate street network has risen: the street network in Bagerhat has become more disconnected.

Bagerhat and Khulna follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these rose steadily.

How do development practices in Bagerhat fare in comparison to others in Khulna? Most recently in 2001-2014, street construction in Bagerhat was the 15th-most disconnected out of the 28 cities in Khulna. Its position in the ranks since 1975 has fallen; relative to other cities in Khulna, street construction in Bagerhat has become more connected. Bagerhat ranked 11th in 1975, 16th in 1976-1990, 12th in 1991-2000 and 15th in 2001-2014.

Bagerhat and Bangladesh follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these rose steadily.

How do development practices in Bagerhat fare in comparison to others in Bangladesh? Most recently in 2001-2014, street construction in Bagerhat was the 69th-most disconnected out of the 157 cities in Bangladesh. Its position in the ranks since 1975 has fallen; relative to other cities in Bangladesh, street construction in Bagerhat has become more connected. Bagerhat ranked 57th in 1975, 92nd in 1976-1990, 62nd in 1991-2000 and 69th in 2001-2014.

Bagerhat and Khulna follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Bagerhat is the 25th-most disconnected out of the 28 cities in Khulna. Its position in the ranks since 1975 has fallen; relative to other cities in Khulna, the street network in Bagerhat has become more connected. Bagerhat ranked 11th in 1975, 17th in 1976-1990, 19th in 1991-2000 and 25th in 2001-2014.

Bagerhat and Bangladesh follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Bagerhat is the 131st-most disconnected out of the 157 cities in Bangladesh. Its position in the ranks since 1975 has fallen; relative to other cities in Bangladesh, the street network in Bagerhat has become more connected. Bagerhat ranked 57th in 1975, 98th in 1976-1990, 118th in 1991-2000 and 131st in 2001-2014.

As of 2015, Bagerhat had a built-up area of 15.07 square kilometers, and a population of 100410 people.

These are some other cities with approximately the same population: