Street-network Sprawl in Ad Da'ein, 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.

Ad Da'ein: city in East Darfur, 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 Ad Da'ein, Sudan on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Ad Da'ein as of 2014, the overall level of street-network sprawl is 0.51, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 2.44, 0.16, 0.84 and 0.51. Disconnectivity in street construction in Ad Da'ein follows a zig-zag trend. In 1976-1990, street construction was most disconnected, while construction was most connected in 1975.

Quantity of street network construction: The street network in Ad Da'ein spans a total of 450 kilometers. The period with the greatest volume of street construction was 1976-1990. These roads have an SNDi of 0.16, which is very 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 2.44, 0.2, 0.5 and 0.51. The SNDi of the aggregate street network in fell at first, but Ad Da'ein has worsened in disconnectivity since 1990.

Ad Da'ein and East Darfur follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these followed a zig-zag trend with an overall decrease.

How do development practices in Ad Da'ein fare in comparison to others in East Darfur? Most recently in 2001-2014, street construction in Ad Da'ein was the 1st-most disconnected out of the 1 cities in East Darfur. Its position in the ranks since 1975 has not changed. Ad Da'ein ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Ad Da'ein and Sudan do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Ad Da'ein followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Sudan peaked in 1991-2000.

How do development practices in Ad Da'ein fare in comparison to others in Sudan? Most recently in 2001-2014, street construction in Ad Da'ein was the 36th-most disconnected out of the 63 cities in Sudan. Its position in the ranks since 1975 has fallen; relative to other cities in Sudan, street construction in Ad Da'ein has become more connected. Ad Da'ein ranked 7th in 1975, 30th in 1976-1990, 18th in 1991-2000 and 36th in 2001-2014.

Ad Da'ein and East Darfur do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Ad Da'ein was at its lowest in 1976-1990, while the SNDi of street constructions in East Darfur followed a zig-zag trend with an overall decrease.

To date, Ad Da'ein is the 1st-most disconnected out of the 1 cities in East Darfur. Its position in the ranks since 1975 has not changed. Ad Da'ein ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

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

To date, Ad Da'ein is the 33rd-most disconnected out of the 63 cities in Sudan. Its position in the ranks since 1975 has fallen; relative to other cities in Sudan, the street network in Ad Da'ein has become more connected. Ad Da'ein ranked 7th in 1975, 31st in 1976-1990, 24th in 1991-2000 and 33rd in 2001-2014.

As of 2015, Ad Da'ein had a built-up area of 8.04 square kilometers, and a population of 560072 people.

These are some other cities with approximately the same population: