Street-network Sprawl in Sahagún, Colombia

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.

Sahagún: city in Córdoba, Colombia

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 Sahagún, Colombia on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Sahagún as of 2014, the overall level of street-network sprawl is 0.37, which is very well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -0.06, nan, 1.75 and 2.59. Data was not available in 1976-1990.

Quantity of street network construction: The street network in Sahagún spans a total of 171 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of -0.06, 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 -0.06, -0.06, 0.14 and 0.37. Overall, the SNDi of the aggregate street network has risen: the street network in Sahagún has become more disconnected.

Sahagún and Córdoba do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, as well as the Córdoba's street network construction.

How do development practices in Sahagún fare in comparison to others in Córdoba? Most recently in 2001-2014, street construction in Sahagún was the 3rd-most disconnected out of the 7 cities in Córdoba. Its position in the ranks since 1975 has risen; relative to other cities in Córdoba, street construction in Sahagún has become more disconnected. Sahagún ranked 5th in 1975, 5th in 1991-2000 and 3rd in 2001-2014. There was no ranking in 1976-1990 due to unavailable data.

Sahagún and Colombia 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 Colombia was at its lowest in 1976-1990.

How do development practices in Sahagún fare in comparison to others in Colombia? Most recently in 2001-2014, street construction in Sahagún was the 42nd-most disconnected out of the 91 cities in Colombia. Its position in the ranks since 1975 has risen; relative to other cities in Colombia, street construction in Sahagún has become more disconnected. Sahagún ranked 81st in 1975, 54th in 1991-2000 and 42nd in 2001-2014. There was no ranking in 1976-1990 due to unavailable data.

Sahagún and Córdoba do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Sahagún rose steadily, while the SNDi of street constructions in Córdoba rose steadily.

To date, Sahagún is the 5th-most disconnected out of the 7 cities in Córdoba. Its position in the ranks since 1975 has not changed. Sahagún ranked 5th in 1975, 5th in 1976-1990, 5th in 1991-2000 and 5th in 2001-2014.

Sahagún and Colombia do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Sahagún rose steadily, while the SNDi of street constructions in Colombia rose steadily.

To date, Sahagún is the 80th-most disconnected out of the 91 cities in Colombia. Its position in the ranks since 1975 has risen; relative to other cities in Colombia, the street network in Sahagún has become more disconnected. Sahagún ranked 81st in 1975, 81st in 1976-1990, 79th in 1991-2000 and 80th in 2001-2014.

As of 2015, Sahagún had a built-up area of 3.56 square kilometers, and a population of 205057 people.

These are some other cities with approximately the same population: