Djelfa: region in Algeria
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 Djelfa, Algeria on the sprawlmap
Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Djelfa as of 2014, the overall level of street-network sprawl is 1.04, which is relatively well-connected.
Trends in street network construction: The SNDis of street construction for the respective time periods are 1.49, 0.68, 1.54 and 1.75. The disconnectivity of new streets constructed in Djelfa fell, then rose. In 1976-1990, new street layouts were the most connected.
Quantity of street network construction: The street network in Djelfa spans a total of 4700 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 0.68, 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 1.49, 0.7, 0.91 and 1.04. The SNDi of the aggregate street network in fell at first, but Djelfa has worsened in disconnectivity since 1990.
The level of street-network sprawl in new development in Djelfa was at its lowest in 1976-1990. To get a sense of how street development has changed in Djelfa, we can consider three of its most populous cities: Djelfa, Messaad and Ain Oussara. Out of the three cities, Djelfa and Messaad do not follow the same trend as the region. The level of street-network sprawl in new development in Djelfa followed a zig-zag trend. The level of street-network sprawl in new development in Messaad followed a zig-zag trend with an overall decrease.
How do development practices in Djelfa fare in comparison to others in Algeria? Most recently in 2001-2014, street construction in Djelfa was the 33rd-most disconnected out of the 46 regions in Algeria. Its position in the ranks since 1975 has risen; relative to other regions in Algeria, street construction in Djelfa has become more disconnected. Djelfa ranked 34th in 1975, 42nd in 1976-1990, 36th in 1991-2000 and 33rd in 2001-2014.
As of 2014, the city with the most disconnected street network in Djelfa is Djelfa with an SNDi of 0.98, which is relatively well-connected. Conversely, the most connected city is Hassi Bahbah with an SNDi of -0.06, which is very well-connected. See trends for these cities: Hassi Bahbah, Djelfa
The level of street-network sprawl in the aggregate network in Djelfa was at its lowest in 1976-1990. To get a sense of how the aggregate street network has changed in Djelfa, we can consider three of its most populous cities: Djelfa, Messaad and Ain Oussara. Out of the three cities, Djelfa does not follow the same trend as the region. The level of street-network sprawl in the aggregate network in Djelfa followed a zig-zag trend.
To date, Djelfa is the 41st-most disconnected out of the 46 regions in Algeria. Its position in the ranks since 1975 has fallen; relative to other regions in Algeria, the street network in Djelfa has become more connected. Djelfa ranked 34th in 1975, 44th in 1976-1990, 41st in 1991-2000 and 41st in 2001-2014.