Street-network Sprawl in Manakara, Madagascar

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.

Manakara: city in Fianarantsoa, Madagascar

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 Manakara, Madagascar on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Manakara as of 2014, the overall level of street-network sprawl is 2.67, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are 2.46, 1.13, 6.46 and nan. Data was not available in 2001-2014.

Quantity of street network construction: The street network in Manakara spans a total of 56 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 2.46, 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 2.46, 2.33, 2.74 and 2.67. Disconnectivity in Manakara's street network follows a zig-zag trend. In 1976-1990, the city was most disconnected; while it was most connected in 1991-2000.

Manakara and Fianarantsoa 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 Fianarantsoa followed a zig-zag trend with an overall increase.

How do development practices in Manakara fare in comparison to others in Fianarantsoa? out of the 2 cities in Fianarantsoa. Its position in the ranks since 1975 has not changed. Manakara ranked 1st in 1975, 2nd in 1976-1990 and 1st in 1991-2000. There was no ranking in 2001-2014 due to unavailable data.

Manakara and Madagascar 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 Madagascar followed a zig-zag trend with an overall increase.

How do development practices in Manakara fare in comparison to others in Madagascar? out of the 12 cities in Madagascar. Its position in the ranks since 1975 has risen; relative to other cities in Madagascar, street construction in Manakara has become more disconnected. Manakara ranked 3rd in 1975, 5th in 1976-1990 and 1st in 1991-2000. There was no ranking in 2001-2014 due to unavailable data.

Manakara and Fianarantsoa do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Manakara followed a zig-zag trend with an overall increase, while the SNDi of street constructions in Fianarantsoa was at its lowest in 1976-1990.

To date, Manakara is the 1st-most disconnected out of the 2 cities in Fianarantsoa. Its position in the ranks since 1975 has not changed. Manakara ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Manakara and Madagascar do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Manakara followed a zig-zag trend with an overall increase, while the SNDi of street constructions in Madagascar rose steadily.

To date, Manakara is the 3rd-most disconnected out of the 12 cities in Madagascar. Its position in the ranks since 1975 has not changed. Manakara ranked 3rd in 1975, 4th in 1976-1990, 3rd in 1991-2000 and 3rd in 2001-2014.

As of 2015, Manakara had a built-up area of 1.1 square kilometers, and a population of 68956 people.

These are some other cities with approximately the same population: