Street-network Sprawl in Yomju, North Korea

What is Street-network sprawl?

Street-network Sprawl is a way to measure urban sprawl, worldwide, through the connectedness of the streets. Less sprawl means more connected, more walkable streets. Well-connected streets – like New York City’s grid – are more walkable and can be served by public transit.

The street network is permanent, and its connectivity affects the livability and environmental footprint of cities for decades and centuries to come. In places with more connected streets, residents drive less and walk more. A well-connected street network is associated with better outcomes for health, the environment, sustainable consumption, social integration, and equity.

We can quantify how connected street networks are with the Street Network Disconnectedness Index (SNDi).

SNDi -- our measure of street-network sprawl (disconnectedness)

The SNDi is a comprehensive measurement of “sprawl”. It captures:

A higher SNDi means less-connected streets – i.e., more sprawl. For the 10137 cities in our dataset, the average SNDi is 2.25, with half of the cities' SNDis falling between 1.08 and 3.25.

More information on the sprawl index can be found in these research papers:

To see the state of street-network sprawl across the globe, visit the sprawlmap.

Yomju: city in P'yŏngan-bukto, North Korea

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 Yomju, North Korea on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Yomju as of 2014, the overall level of street-network sprawl is 4.98, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 4.69, nan, nan and nan. Data was not available in 1976-1990, 1991-2000 and 2001-2014.

Quantity of street network construction: The street network in Yomju spans a total of 25 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 4.69, 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 4.69, 4.89, 4.89 and 4.98. Overall, the SNDi of the aggregate street network has risen: the street network in Yomju has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.2 points, but between 1991-2000 and 2001-2014, it rose by just 0.09.

Yomju and P'yŏngan-bukto do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in P'yŏngan-bukto followed a zig-zag trend with an overall increase.

How do development practices in Yomju fare in comparison to others in P'yŏngan-bukto? out of the 14 cities in P'yŏngan-bukto. Yomju ranked 4th in 1975. There was no ranking in 1976-1990, 1991-2000, and 2001-2014 due to unavailable data.

Yomju and North Korea do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in North Korea followed a zig-zag trend with an overall increase.

How do development practices in Yomju fare in comparison to others in North Korea? out of the 79 cities in North Korea. Yomju ranked 40th in 1975. There was no ranking in 1976-1990, 1991-2000, and 2001-2014 due to unavailable data.

Yomju and P'yŏngan-bukto do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Yomju rose steadily, while the SNDi of street constructions in P'yŏngan-bukto followed a zig-zag trend with an overall increase.

To date, Yomju is the 5th-most disconnected out of the 14 cities in P'yŏngan-bukto. Its position in the ranks since 1975 has fallen; relative to other cities in P'yŏngan-bukto, the street network in Yomju has become more connected. Yomju ranked 4th in 1975, 5th in 1976-1990, 5th in 1991-2000 and 5th in 2001-2014.

Yomju and North Korea do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Yomju rose steadily, while the SNDi of street constructions in North Korea rose steadily.

To date, Yomju is the 34th-most disconnected out of the 79 cities in North Korea. Its position in the ranks since 1975 has risen; relative to other cities in North Korea, the street network in Yomju has become more disconnected. Yomju ranked 40th in 1975, 34th in 1976-1990, 34th in 1991-2000 and 34th in 2001-2014.

As of 2015, Yomju had a built-up area of 0.71 square kilometers, and a population of 55842 people.

These are some other cities with approximately the same population: