Street-network Sprawl in Gabela, Angola

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.

Gabela: city in Cuanza Sul, Angola

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 Gabela, Angola on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Gabela as of 2014, the overall level of street-network sprawl is 3.22, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are 3.87, 3.87, 2.63 and 2.94. The disconnectivity of new streets constructed in Gabela fell, then rose. In 1991-2000, new street layouts were the most connected.

Quantity of street network construction: The street network in Gabela spans a total of 60 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 2.94, 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 3.87, 3.85, 3.49 and 3.22. Overall, the SNDi of the aggregate street network has fallen: the street network in Gabela has become more connected. This decrease has quickened: between 1975 and 1976-1990, SNDi fell by 0.02 points, but between 1991-2000 and 2001-2014, it fell by just 0.27.

Gabela and Cuanza Sul do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Gabela was at its lowest in 1991-2000, while the SNDi of street constructions in Cuanza Sul peaked in 1991-2000.

How do development practices in Gabela fare in comparison to others in Cuanza Sul? Most recently in 2001-2014, street construction in Gabela was the 3rd-most disconnected out of the 6 cities in Cuanza Sul. Its position in the ranks since 1975 has fallen; relative to other cities in Cuanza Sul, street construction in Gabela has become more connected. Gabela ranked 1st in 1975, 1st in 1976-1990, 3rd in 1991-2000 and 3rd in 2001-2014.

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

How do development practices in Gabela fare in comparison to others in Angola? Most recently in 2001-2014, street construction in Gabela was the 17th-most disconnected out of the 51 cities in Angola. Its position in the ranks since 1975 has fallen; relative to other cities in Angola, street construction in Gabela has become more connected. Gabela ranked 2nd in 1975, 5th in 1976-1990, 12th in 1991-2000 and 17th in 2001-2014.

Gabela and Cuanza Sul do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Gabela fell steadily, while the SNDi of street constructions in Cuanza Sul peaked in 1991-2000.

To date, Gabela is the 1st-most disconnected out of the 6 cities in Cuanza Sul. Its position in the ranks since 1975 has not changed. Gabela ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

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

To date, Gabela is the 9th-most disconnected out of the 51 cities in Angola. Its position in the ranks since 1975 has fallen; relative to other cities in Angola, the street network in Gabela has become more connected. Gabela ranked 2nd in 1975, 2nd in 1976-1990, 4th in 1991-2000 and 9th in 2001-2014.

As of 2015, Gabela had a built-up area of 3.54 square kilometers, and a population of 104276 people.

These are some other cities with approximately the same population: