Delta: region in Nigeria
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 Delta, Nigeria on the sprawlmap
Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Delta as of 2014, the overall level of street-network sprawl is 4.11, which is highly disconnected.
Trends in street network construction: The SNDis of street construction for the respective time periods are 3.33, 4.14, 3.64 and 5.04. Disconnectivity in street construction in Delta follows a zig-zag trend. In 1975, street construction was most disconnected, while construction was most connected in 2001-2014.
Quantity of street network construction: The street network in Delta spans a total of 11264 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 5.04, 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 3.33, 3.81, 3.78 and 4.11. Disconnectivity in Delta's street network follows a zig-zag trend. In 1975, the region was most disconnected; while it was most connected in 2001-2014.
The level of street-network sprawl in new development in Delta followed a zig-zag trend with an overall increase. To get a sense of how street development has changed in Delta, we can consider three of its most populous cities: Warri, Asaba and Sapele. Out of the three cities, Warri does not follow the same trend as the region. The level of street-network sprawl in new development in Warri peaked in 1991-2000.
How do development practices in Delta fare in comparison to others in Nigeria? Most recently in 2001-2014, street construction in Delta was the 8th-most disconnected out of the 37 regions in Nigeria. Its position in the ranks since 1975 has risen; relative to other regions in Nigeria, street construction in Delta has become more disconnected. Delta ranked 10th in 1975, 9th in 1976-1990, 19th in 1991-2000 and 8th in 2001-2014.
As of 2014, the city with the most disconnected street network in Delta is Ughelli with an SNDi of 5.58, which is highly disconnected. Conversely, the most connected city is Owerre with an SNDi of 0.08, which is very well-connected. See trends for these cities: Owerre, Ughelli
The level of street-network sprawl in the aggregate network in Delta followed a zig-zag trend with an overall increase. To get a sense of how the aggregate street network has changed in Delta, we can consider three of its most populous cities: Warri, Asaba and Sapele. Out of the three cities, Warri and Asaba do not follow the same trend as the region. The level of street-network sprawl in the aggregate network in Warri rose steadily. The level of street-network sprawl in the aggregate network in Asaba peaked in 1976-1990.
To date, Delta is the 11th-most disconnected out of the 37 regions in Nigeria. Its position in the ranks since 1975 has fallen; relative to other regions in Nigeria, the street network in Delta has become more connected. Delta ranked 10th in 1975, 8th in 1976-1990, 12th in 1991-2000 and 11th in 2001-2014.