Sa`dah: region in Yemen
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 Sa`dah, Yemen on the sprawlmap
Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Sa`dah as of 2014, the overall level of street-network sprawl is 5.74, which is highly disconnected.
Trends in street network construction: The SNDis of street construction for the respective time periods are 8.08, nan, 7.55 and 3.25. Data was not available in 1976-1990.
Quantity of street network construction: The street network in Sa`dah spans a total of 953 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 8.08, 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 8.08, 8.03, 6.82 and 5.74. Overall, the SNDi of the aggregate street network has fallen: the street network in Sa`dah has become more connected. This decrease has quickened: between 1975 and 1976-1990, SNDi fell by 0.05 points, but between 1991-2000 and 2001-2014, it fell by just 1.08.
The level of street-network sprawl in new development in Sa`dah followed a zig-zag trend with an overall decrease. To get a sense of how street development has changed in Sa`dah, we can consider one of its most populous cities: Sa'dah. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Sa'dah followed a zig-zag trend.
How do development practices in Sa`dah fare in comparison to others in Yemen? Most recently in 2001-2014, street construction in Sa`dah was the 11th-most disconnected out of the 16 regions in Yemen. Its position in the ranks since 1975 has fallen; relative to other regions in Yemen, street construction in Sa`dah has become more connected. Sa`dah ranked 3rd in 1975, 5th in 1991-2000 and 11th in 2001-2014. There was no ranking in 1976-1990 due to unavailable data.
As of 2014, the city with the most disconnected street network in Sa`dah is Sa'dah with an SNDi of 1.73, which is relatively well-connected. Conversely, the most connected city is Sa'dah with an SNDi of 1.73, which is relatively well-connected. See trends for these cities: Sa'dah, Sa'dah
The level of street-network sprawl in the aggregate network in Sa`dah fell steadily. To get a sense of how the aggregate street network has changed in Sa`dah, we can consider one of its most populous cities: Sa'dah. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Sa'dah followed a zig-zag trend.
To date, Sa`dah is the 5th-most disconnected out of the 16 regions in Yemen. Its position in the ranks since 1975 has fallen; relative to other regions in Yemen, the street network in Sa`dah has become more connected. Sa`dah ranked 3rd in 1975, 3rd in 1976-1990, 7th in 1991-2000 and 5th in 2001-2014.