Alborz: region in Iran
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 Alborz, Iran on the sprawlmap
Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Alborz as of 2014, the overall level of street-network sprawl is 3.7, which is highly disconnected.
Trends in street network construction: The SNDis of street construction for the respective time periods are 4.26, 3.34, 4.0 and 4.81. The disconnectivity of new streets constructed in Alborz fell, then rose. In 1976-1990, new street layouts were the most connected.
Quantity of street network construction: The street network in Alborz spans a total of 8655 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 3.34, 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 4.26, 3.57, 3.6 and 3.7. The SNDi of the aggregate street network in fell at first, but Alborz has worsened in disconnectivity since 1990.
The level of street-network sprawl in new development in Alborz was at its lowest in 1976-1990. To get a sense of how street development has changed in Alborz, we can consider three of its most populous cities: Nazarabad, Safadasht and Mahdasht. Out of the three cities, Safadasht does not follow the same trend as the region. The level of street-network sprawl in new development in Safadasht followed a zig-zag trend.
How do development practices in Alborz fare in comparison to others in Iran? Most recently in 2001-2014, street construction in Alborz was the 7th-most disconnected out of the 31 regions in Iran. Its position in the ranks since 1975 has risen; relative to other regions in Iran, street construction in Alborz has become more disconnected. Alborz ranked 11th in 1975, 5th in 1976-1990, 8th in 1991-2000 and 7th in 2001-2014.
As of 2014, the city with the most disconnected street network in Alborz is Hashtgerd with an SNDi of 3.34, which is highly disconnected. Conversely, the most connected city is Nazarabad with an SNDi of 1.68, which is relatively well-connected. See trends for these cities: Nazarabad, Hashtgerd
The level of street-network sprawl in the aggregate network in Alborz was at its lowest in 1976-1990. To get a sense of how the aggregate street network has changed in Alborz, we can consider three of its most populous cities: Nazarabad, Safadasht and Mahdasht. Out of the three cities, Safadasht does not follow the same trend as the region. The level of street-network sprawl in the aggregate network in Safadasht followed a zig-zag trend.
To date, Alborz is the 7th-most disconnected out of the 31 regions in Iran. Its position in the ranks since 1975 has risen; relative to other regions in Iran, the street network in Alborz has become more disconnected. Alborz ranked 11th in 1975, 8th in 1976-1990, 7th in 1991-2000 and 7th in 2001-2014.