Ilocos Sur: region in Philippines
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 Ilocos Sur, Philippines on the sprawlmap
Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Ilocos Sur as of 2014, the overall level of street-network sprawl is 4.02, which is highly disconnected.
Trends in street network construction: The SNDis of street construction for the respective time periods are 2.87, 4.47, 6.6 and 7.31. In each period, new street development in Ilocos Sur steadily grows more disconnected than in the last. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 1.6 points, but between 1991-2000 and 2001-2014, it rose by just 0.71.
Quantity of street network construction: The street network in Ilocos Sur spans a total of 2249 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 4.47, 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 2.87, 3.91, 3.97 and 4.02. Overall, the SNDi of the aggregate street network has risen: the street network in Ilocos Sur has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 1.04 points, but between 1991-2000 and 2001-2014, it rose by just 0.05.
The level of street-network sprawl in new development in Ilocos Sur rose steadily. To get a sense of how street development has changed in Ilocos Sur, we can consider one of its most populous cities: Vigan. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Vigan followed a zig-zag trend with an overall increase.
How do development practices in Ilocos Sur fare in comparison to others in Philippines? Most recently in 2001-2014, street construction in Ilocos Sur was the 7th-most disconnected out of the 51 regions in Philippines. Its position in the ranks since 1975 has risen; relative to other regions in Philippines, street construction in Ilocos Sur has become more disconnected. Ilocos Sur ranked 39th in 1975, 32nd in 1976-1990, 13th in 1991-2000 and 7th in 2001-2014.
As of 2014, the city with the most disconnected street network in Ilocos Sur is Vigan with an SNDi of 2.77, which is in the 40th to 60th percentile of disconnectedness. Conversely, the most connected city is Vigan with an SNDi of 2.77, which is in the 40th to 60th percentile of disconnectedness. See trends for these cities: Vigan, Vigan
The level of street-network sprawl in the aggregate network in Ilocos Sur rose steadily. To get a sense of how the aggregate street network has changed in Ilocos Sur, we can consider one of its most populous cities: Vigan. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Vigan followed a zig-zag trend with an overall increase.
To date, Ilocos Sur is the 40th-most disconnected out of the 51 regions in Philippines. Its position in the ranks since 1975 has fallen; relative to other regions in Philippines, the street network in Ilocos Sur has become more connected. Ilocos Sur ranked 39th in 1975, 33rd in 1976-1990, 37th in 1991-2000 and 40th in 2001-2014.