Saint-Louis: region in 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 Saint-Louis, Senegal on the sprawlmap
Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Saint-Louis as of 2014, the overall level of street-network sprawl is 1.15, which is relatively well-connected.
Trends in street network construction: The SNDis of street construction for the respective time periods are 0.67, 0.57, 1.23 and 4.23. The disconnectivity of new streets constructed in Saint-Louis fell, then rose. In 1976-1990, new street layouts were the most connected.
Quantity of street network construction: The street network in Saint-Louis spans a total of 650 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 0.57, which is relatively 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 0.67, 0.61, 0.79 and 1.15. The SNDi of the aggregate street network in fell at first, but Saint-Louis has worsened in disconnectivity since 1990.
The level of street-network sprawl in new development in Saint-Louis was at its lowest in 1976-1990. To get a sense of how street development has changed in Saint-Louis, we can consider three of its most populous cities: Saint-Louis, Podor and Richard-Toll. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Saint-Louis peaked in 1991-2000. The level of street-network sprawl in new development in Podor followed a zig-zag trend. The level of street-network sprawl in new development in Richard-Toll followed a zig-zag trend.
How do development practices in Saint-Louis fare in comparison to others in Senegal? Most recently in 2001-2014, street construction in Saint-Louis was the 2nd-most disconnected out of the 13 regions in Senegal. Its position in the ranks since 1975 has risen; relative to other regions in Senegal, street construction in Saint-Louis has become more disconnected. Saint-Louis ranked 6th in 1975, 9th in 1976-1990, 8th in 1991-2000 and 2nd in 2001-2014.
As of 2014, the city with the most disconnected street network in Saint-Louis is Richard-Toll with an SNDi of 0.71, which is relatively well-connected. Conversely, the most connected city is Podor with an SNDi of -1.59, which is very well-connected. See trends for these cities: Podor, Richard-Toll
The level of street-network sprawl in the aggregate network in Saint-Louis was at its lowest in 1976-1990. To get a sense of how the aggregate street network has changed in Saint-Louis, we can consider three of its most populous cities: Saint-Louis, Podor and Richard-Toll. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Saint-Louis followed a zig-zag trend with an overall increase. The level of street-network sprawl in the aggregate network in Podor followed a zig-zag trend. The level of street-network sprawl in the aggregate network in Richard-Toll followed a zig-zag trend with an overall decrease.
To date, Saint-Louis is the 7th-most disconnected out of the 13 regions in Senegal. Its position in the ranks since 1975 has fallen; relative to other regions in Senegal, the street network in Saint-Louis has become more connected. Saint-Louis ranked 6th in 1975, 10th in 1976-1990, 9th in 1991-2000 and 7th in 2001-2014.