Street-network Sprawl in Keur Madiabel, Senegal

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.

Keur Madiabel: city in Kaolack, Senegal

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 Keur Madiabel, Senegal on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Keur Madiabel as of 2014, the overall level of street-network sprawl is -0.36, which is very well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are nan, -0.42, 0.61 and -0.49. Data was not available in 1975.

Quantity of street network construction: The street network in Keur Madiabel spans a total of 56 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, -0.42, -0.28 and -0.36. Data was not available in 1975.

Keur Madiabel and Kaolack 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 Kaolack peaked in 1991-2000.

How do development practices in Keur Madiabel fare in comparison to others in Kaolack? Most recently in 2001-2014, street construction in Keur Madiabel was the 4th-most disconnected out of the 4 cities in Kaolack. Its position in the ranks since 1975 has not changed. Keur Madiabel ranked 4th in 1976-1990, 4th in 1991-2000 and 4th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Keur Madiabel and Senegal 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 Senegal rose steadily.

How do development practices in Keur Madiabel fare in comparison to others in Senegal? Most recently in 2001-2014, street construction in Keur Madiabel was the 23rd-most disconnected out of the 31 cities in Senegal. Its position in the ranks since 1975 has not changed. Keur Madiabel ranked 23rd in 1976-1990, 16th in 1991-2000 and 23rd in 2001-2014. There was no ranking in 1975 due to unavailable data.

Keur Madiabel and Kaolack 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 Kaolack rose steadily.

To date, Keur Madiabel is the 4th-most disconnected out of the 4 cities in Kaolack. Its position in the ranks since 1975 has not changed. Keur Madiabel ranked 4th in 1976-1990, 4th in 1991-2000 and 4th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Keur Madiabel and Senegal 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 Senegal rose steadily.

To date, Keur Madiabel is the 28th-most disconnected out of the 31 cities in Senegal. Its position in the ranks since 1975 has fallen; relative to other cities in Senegal, the street network in Keur Madiabel has become more connected. Keur Madiabel ranked 24th in 1976-1990, 24th in 1991-2000 and 28th in 2001-2014. There was no ranking in 1975 due to unavailable data.

As of 2015, Keur Madiabel had a built-up area of 0.74 square kilometers, and a population of 72577 people.

These are some other cities with approximately the same population: