Street-network Sprawl in South Kurdufan, Sudan

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.

South Kurdufan: region in Sudan

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 South Kurdufan, Sudan on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in South Kurdufan as of 2014, the overall level of street-network sprawl is 2.09, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.16, 1.88, 3.45 and 2.51. Street construction in South Kurdufan 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 South Kurdufan spans a total of 1766 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 2.51, 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 1.16, 1.07, 1.41 and 2.09. The SNDi of the aggregate street network in fell at first, but South Kurdufan has worsened in disconnectivity since 1990.

The level of street-network sprawl in new development in South Kurdufan peaked in 1991-2000. To get a sense of how street development has changed in South Kurdufan, we can consider three of its most populous cities: Abu Jibeha, Dilling and Kaduqli. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Abu Jibeha followed a zig-zag trend. The level of street-network sprawl in new development in Dilling followed a zig-zag trend. The level of street-network sprawl in new development in Kaduqli was at its lowest in 1991-2000.

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

As of 2014, the city with the most disconnected street network in South Kurdufan is Al ‘Abbāsiyya with an SNDi of 3.07, which is in the 40th to 60th percentile of disconnectedness. Conversely, the most connected city is Kaduqli with an SNDi of 0.28, which is very well-connected. See trends for these cities: Kaduqli, Al ‘Abbāsiyya

The level of street-network sprawl in the aggregate network in South Kurdufan was at its lowest in 1976-1990. To get a sense of how the aggregate street network has changed in South Kurdufan, we can consider three of its most populous cities: Abu Jibeha, Dilling and Kaduqli. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Abu Jibeha followed a zig-zag trend. The level of street-network sprawl in the aggregate network in Dilling followed a zig-zag trend. The level of street-network sprawl in the aggregate network in Kaduqli was at its lowest in 1991-2000.

To date, South Kurdufan is the 6th-most disconnected out of the 17 regions in Sudan. Its position in the ranks since 1975 has risen; relative to other regions in Sudan, the street network in South Kurdufan has become more disconnected. South Kurdufan ranked 9th in 1975, 9th in 1976-1990, 8th in 1991-2000 and 6th in 2001-2014.