Street-network Sprawl in Cuando Cubango, 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.

Cuando Cubango: region in 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 Cuando Cubango, Angola on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Cuando Cubango as of 2014, the overall level of street-network sprawl is 4.27, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.45, 4.18, 3.44 and 4.41. Disconnectivity in street construction in Cuando Cubango follows a zig-zag trend. In 1975, street construction was most disconnected, while construction was most connected in 2001-2014.

Quantity of street network construction: The street network in Cuando Cubango spans a total of 4832 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 4.41, 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 1.45, 3.14, 3.19 and 4.27. Overall, the SNDi of the aggregate street network has risen: the street network in Cuando Cubango has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 1.69 points, but between 1991-2000 and 2001-2014, it rose by just 1.08.

The level of street-network sprawl in new development in Cuando Cubango followed a zig-zag trend with an overall increase. To get a sense of how street development has changed in Cuando Cubango, we can consider one of its most populous cities: Menongue. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Menongue peaked in 1976-1990.

How do development practices in Cuando Cubango fare in comparison to others in Angola? Most recently in 2001-2014, street construction in Cuando Cubango was the 6th-most disconnected out of the 18 regions in Angola. Its position in the ranks since 1975 has risen; relative to other regions in Angola, street construction in Cuando Cubango has become more disconnected. Cuando Cubango ranked 14th in 1975, 4th in 1976-1990, 12th in 1991-2000 and 6th in 2001-2014.

As of 2014, the city with the most disconnected street network in Cuando Cubango is Menongue with an SNDi of 1.08, which is relatively well-connected. Conversely, the most connected city is Menongue with an SNDi of 1.08, which is relatively well-connected. See trends for these cities: Menongue, Menongue

The level of street-network sprawl in the aggregate network in Cuando Cubango rose steadily. To get a sense of how the aggregate street network has changed in Cuando Cubango, we can consider one of its most populous cities: Menongue. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Menongue peaked in 1991-2000.

To date, Cuando Cubango is the 6th-most disconnected out of the 18 regions in Angola. Its position in the ranks since 1975 has risen; relative to other regions in Angola, the street network in Cuando Cubango has become more disconnected. Cuando Cubango ranked 14th in 1975, 12th in 1976-1990, 12th in 1991-2000 and 6th in 2001-2014.