Street-network Sprawl in eMbalenhle, South Africa

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.

eMbalenhle: city in Mpumalanga, South Africa

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 eMbalenhle, South Africa on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in eMbalenhle as of 2014, the overall level of street-network sprawl is 3.64, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.92, 4.23, 3.43 and 3.38. Street construction in eMbalenhle increased in disconnectivity initially but has since improved. The streets constructed in 1976-1990 were the most disconnected.

Quantity of street network construction: The street network in eMbalenhle spans a total of 275 kilometers. It is dominated by roads constructed in 1991-2000. These roads have an SNDi of 3.43, 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 1.92, 3.93, 3.65 and 3.64. The aggregate street network in eMbalenhle increased in disconnectivity initially,but the trend has turned around after 1990.

eMbalenhle and Mpumalanga do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in eMbalenhle peaked in 1976-1990, while the SNDi of street constructions in Mpumalanga rose steadily.

How do development practices in eMbalenhle fare in comparison to others in Mpumalanga? Most recently in 2001-2014, street construction in eMbalenhle was the 8th-most disconnected out of the 11 cities in Mpumalanga. Its position in the ranks since 1975 has fallen; relative to other cities in Mpumalanga, street construction in eMbalenhle has become more connected. eMbalenhle ranked 5th in 1975, 1st in 1976-1990, 7th in 1991-2000 and 8th in 2001-2014.

eMbalenhle and South Africa do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in eMbalenhle peaked in 1976-1990, while the SNDi of street constructions in South Africa followed a zig-zag trend with an overall increase.

How do development practices in eMbalenhle fare in comparison to others in South Africa? Most recently in 2001-2014, street construction in eMbalenhle was the 44th-most disconnected out of the 77 cities in South Africa. Its position in the ranks since 1975 has not changed. eMbalenhle ranked 44th in 1975, 15th in 1976-1990, 44th in 1991-2000 and 44th in 2001-2014.

eMbalenhle and Mpumalanga do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in eMbalenhle peaked in 1976-1990, while the SNDi of street constructions in Mpumalanga rose steadily.

To date, eMbalenhle is the 2nd-most disconnected out of the 11 cities in Mpumalanga. Its position in the ranks since 1975 has risen; relative to other cities in Mpumalanga, the street network in eMbalenhle has become more disconnected. eMbalenhle ranked 5th in 1975, 2nd in 1976-1990, 1st in 1991-2000 and 2nd in 2001-2014.

eMbalenhle and South Africa do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in eMbalenhle peaked in 1976-1990, while the SNDi of street constructions in South Africa rose steadily.

To date, eMbalenhle is the 25th-most disconnected out of the 77 cities in South Africa. Its position in the ranks since 1975 has risen; relative to other cities in South Africa, the street network in eMbalenhle has become more disconnected. eMbalenhle ranked 44th in 1975, 20th in 1976-1990, 23rd in 1991-2000 and 25th in 2001-2014.

As of 2015, eMbalenhle had a built-up area of 10.94 square kilometers, and a population of 128126 people.

These are some other cities with approximately the same population: