Street-network Sprawl in Gumel, Nigeria

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.

Gumel: city in Jigawa, Nigeria

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 Gumel, Nigeria on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Gumel as of 2014, the overall level of street-network sprawl is 0.82, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -0.12, 0.04, 1.28 and 1.45. In each period, new street development in Gumel steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Gumel spans a total of 97 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 1.45, 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 -0.12, 0.01, 0.09 and 0.82. Overall, the SNDi of the aggregate street network has risen: the street network in Gumel has become more disconnected.

Gumel and Jigawa do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Gumel rose steadily, while the SNDi of street constructions in Jigawa peaked in 1991-2000.

How do development practices in Gumel fare in comparison to others in Jigawa? Most recently in 2001-2014, street construction in Gumel was the 2nd-most disconnected out of the 9 cities in Jigawa. Its position in the ranks since 1975 has risen; relative to other cities in Jigawa, street construction in Gumel has become more disconnected. Gumel ranked 4th in 1975, 4th in 1976-1990, 4th in 1991-2000 and 2nd in 2001-2014.

Gumel and Nigeria do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Gumel rose steadily, while the SNDi of street constructions in Nigeria peaked in 1991-2000.

How do development practices in Gumel fare in comparison to others in Nigeria? Most recently in 2001-2014, street construction in Gumel was the 261st-most disconnected out of the 411 cities in Nigeria. Its position in the ranks since 1975 has fallen; relative to other cities in Nigeria, street construction in Gumel has become more connected. Gumel ranked 207th in 1975, 283rd in 1976-1990, 189th in 1991-2000 and 261st in 2001-2014.

Gumel and Jigawa do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Gumel rose steadily, while the SNDi of street constructions in Jigawa peaked in 1991-2000.

To date, Gumel is the 4th-most disconnected out of the 9 cities in Jigawa. Its position in the ranks since 1975 has not changed. Gumel ranked 4th in 1975, 4th in 1976-1990, 4th in 1991-2000 and 4th in 2001-2014.

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

To date, Gumel is the 290th-most disconnected out of the 411 cities in Nigeria. Its position in the ranks since 1975 has fallen; relative to other cities in Nigeria, the street network in Gumel has become more connected. Gumel ranked 207th in 1975, 293rd in 1976-1990, 301st in 1991-2000 and 290th in 2001-2014.

As of 2015, Gumel had a built-up area of 3.75 square kilometers, and a population of 118368 people.

These are some other cities with approximately the same population: