Street-network Sprawl in Valaichchenai EP, Sri Lanka

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.

Valaichchenai EP: city in Batticaloa, Sri Lanka

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 Valaichchenai EP, Sri Lanka on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Valaichchenai EP as of 2014, the overall level of street-network sprawl is 2.08, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.66, 2.36, nan and 2.93. Data was not available in 1991-2000.

Quantity of street network construction: The street network in Valaichchenai EP spans a total of 154 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 2.36, which is in the 40th to 60th percentile of disconnectedness.

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 1.66, 2.07, 2.07 and 2.08. Overall, the SNDi of the aggregate street network has risen: the street network in Valaichchenai EP has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.41 points, but between 1991-2000 and 2001-2014, it rose by just 0.01.

Valaichchenai EP and Batticaloa 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 Batticaloa rose steadily.

How do development practices in Valaichchenai EP fare in comparison to others in Batticaloa? Most recently in 2001-2014, street construction in Valaichchenai EP was the 2nd-most disconnected out of the 2 cities in Batticaloa. Its position in the ranks since 1975 has not changed. Valaichchenai EP ranked 1st in 1975, 1st in 1976-1990 and 2nd in 2001-2014. There was no ranking in 1991-2000 due to unavailable data.

Valaichchenai EP and Sri Lanka 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 Sri Lanka followed a zig-zag trend with an overall increase.

How do development practices in Valaichchenai EP fare in comparison to others in Sri Lanka? Most recently in 2001-2014, street construction in Valaichchenai EP was the 19th-most disconnected out of the 22 cities in Sri Lanka. Its position in the ranks since 1975 has not changed. Valaichchenai EP ranked 13th in 1975, 13th in 1976-1990 and 19th in 2001-2014. There was no ranking in 1991-2000 due to unavailable data.

Valaichchenai EP and Batticaloa do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Valaichchenai EP rose steadily, while the SNDi of street constructions in Batticaloa rose steadily.

To date, Valaichchenai EP is the 1st-most disconnected out of the 2 cities in Batticaloa. Its position in the ranks since 1975 has not changed. Valaichchenai EP ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Valaichchenai EP and Sri Lanka do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Valaichchenai EP rose steadily, while the SNDi of street constructions in Sri Lanka followed a zig-zag trend with an overall increase.

To date, Valaichchenai EP is the 18th-most disconnected out of the 22 cities in Sri Lanka. Its position in the ranks since 1975 has fallen; relative to other cities in Sri Lanka, the street network in Valaichchenai EP has become more connected. Valaichchenai EP ranked 13th in 1975, 18th in 1976-1990, 18th in 1991-2000 and 18th in 2001-2014.

As of 2015, Valaichchenai EP had a built-up area of 6.75 square kilometers, and a population of 55066 people.

These are some other cities with approximately the same population: