Street-network Sprawl in Gwoza, 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.

Gwoza: city in Borno, 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 Gwoza, Nigeria on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Gwoza as of 2014, the overall level of street-network sprawl is 0.96, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.23, 0.94, 1.01 and 0.99. Street construction in Gwoza increased in disconnectivity initially but has since improved. The streets constructed in 1991-2000 were the most disconnected.

Quantity of street network construction: The street network in Gwoza spans a total of 104 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 0.99, 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 0.23, 0.92, 0.94 and 0.96. Overall, the SNDi of the aggregate street network has risen: the street network in Gwoza has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.69 points, but between 1991-2000 and 2001-2014, it rose by just 0.01.

Gwoza and Borno do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Gwoza peaked in 1991-2000, while the SNDi of street constructions in Borno was at its lowest in 1976-1990.

How do development practices in Gwoza fare in comparison to others in Borno? Most recently in 2001-2014, street construction in Gwoza was the 9th-most disconnected out of the 17 cities in Borno. Its position in the ranks since 1975 has fallen; relative to other cities in Borno, street construction in Gwoza has become more connected. Gwoza ranked 4th in 1975, 5th in 1976-1990, 6th in 1991-2000 and 9th in 2001-2014.

Gwoza and Nigeria follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these peaked in 1991-2000.

How do development practices in Gwoza fare in comparison to others in Nigeria? Most recently in 2001-2014, street construction in Gwoza was 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, street construction in Gwoza has become more connected. Gwoza ranked 193rd in 1975, 230th in 1976-1990, 198th in 1991-2000 and 290th in 2001-2014.

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

To date, Gwoza is the 6th-most disconnected out of the 17 cities in Borno. Its position in the ranks since 1975 has fallen; relative to other cities in Borno, the street network in Gwoza has become more connected. Gwoza ranked 4th in 1975, 5th in 1976-1990, 4th in 1991-2000 and 6th in 2001-2014.

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

To date, Gwoza is the 274th-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 Gwoza has become more connected. Gwoza ranked 193rd in 1975, 232nd in 1976-1990, 241st in 1991-2000 and 274th in 2001-2014.

As of 2015, Gwoza had a built-up area of 1.69 square kilometers, and a population of 196485 people.

These are some other cities with approximately the same population: