Street-network Sprawl in Dejen, Ethiopia

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.

Dejen: city in Amhara, Ethiopia

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 Dejen, Ethiopia on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Dejen as of 2014, the overall level of street-network sprawl is 0.62, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are nan, nan, 1.29 and 1.01. Data was not available in 1975 and 1976-1990.

Quantity of street network construction: The street network in Dejen spans a total of 30 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of nan, 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 nan, nan, 0.34 and 0.62. Data was not available in 1975 and 1976-1990.

Dejen and Amhara do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Amhara was at its lowest in 1976-1990.

How do development practices in Dejen fare in comparison to others in Amhara? Most recently in 2001-2014, street construction in Dejen was the 35th-most disconnected out of the 49 cities in Amhara. Its position in the ranks since 1975 has fallen; relative to other cities in Amhara, street construction in Dejen has become more connected. Dejen ranked 15th in 1991-2000 and 35th in 2001-2014. There was no ranking in 1975 and 1976-1990 due to unavailable data.

Dejen and Ethiopia do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Ethiopia followed a zig-zag trend with an overall increase.

How do development practices in Dejen fare in comparison to others in Ethiopia? Most recently in 2001-2014, street construction in Dejen was the 132nd-most disconnected out of the 252 cities in Ethiopia. Its position in the ranks since 1975 has fallen; relative to other cities in Ethiopia, street construction in Dejen has become more connected. Dejen ranked 45th in 1991-2000 and 132nd in 2001-2014. There was no ranking in 1975 and 1976-1990 due to unavailable data.

Dejen and Amhara do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Amhara was at its lowest in 1976-1990.

To date, Dejen is the 40th-most disconnected out of the 49 cities in Amhara. Its position in the ranks since 1975 has fallen; relative to other cities in Amhara, the street network in Dejen has become more connected. Dejen ranked 23rd in 1991-2000 and 40th in 2001-2014. There was no ranking in 1975 and 1976-1990 due to unavailable data.

Dejen and Ethiopia do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Ethiopia followed a zig-zag trend with an overall increase.

To date, Dejen is the 173rd-most disconnected out of the 252 cities in Ethiopia. Its position in the ranks since 1975 has fallen; relative to other cities in Ethiopia, the street network in Dejen has become more connected. Dejen ranked 99th in 1991-2000 and 173rd in 2001-2014. There was no ranking in 1975 and 1976-1990 due to unavailable data.

As of 2015, Dejen had a built-up area of 0.29 square kilometers, and a population of 114128 people.

These are some other cities with approximately the same population: