The Economist Intelligence Unit -- the city rankings specialists -- has a new list claiming the best cities to live. And they have an interesting new livability metrics to judge the world's cities.

The rankings combined EIU's popular "Liveability Index" with a new measure that focuses on spatial characteristics. The "Spatially Adjusted Livability Index" takes into account seven characteristics:

Sprawl: using the "estimated relation between the metropolitan region’s surface and its total population, the overall coherence of the metropolitan form and an estimate of the extent of low density urban fabric."

Green space: based on "the distribution of green spaces within the metropolitan region, the number of local green spaces and the number of metropolitan scale green spaces."

Natural assets: using "Google Earth satellite imagery and information from Open Street Map to assign points to cities based on the natural features" and the number of protected areas around a city center.

Cultural assets: counting the number of UNESCO World Heritage Sites in the vicinity of the cities.

Connectivity: calculating how many cities can be reached by plane from a city and the average number of flights from that city.

Isolation: based on the number of large cities near a city.

Pollution: using World Health Organisation (WHO)’s Air Pollution in Cities database to calculate air quality with a concentration of particulate matter of over 10 micrometres.

Using these criteria here are the 10 best cities to live in:

Hong Kong Amsterdam Osaka Paris Sydney Stockholm Berlin Toronto Munich Tokyo

And the 10 worst:

Tehran Nairobi Lusaka Phnom Penh Karachi Dakar Abidjan Dhaka Lagos Harare

The top ranked city in the U.S. was Washington, D.C. (14), followed by Chicago (15), New York (16), Los Angeles (17), and San Francisco (18).

Of course, no rankings or measurements are perfect, and this one is no exception. Only 70 of the cities on the original EIU "Liveability Index" had their spatial characterists analyzed, for example.

Nonetheless, spatial characteristics are important -- if sometimes overlooked -- aspects of livability. And it's not just about how many parks cities have. Where cities are located and how they grow can have major impacts on the economy, health and wellness of cities and their inhabitants.

UPDATE: Anthony Ilukwe from Buzzdata points out that this ranking was part of a contest in which EIU partnered with Buzzdata to crowdsource a metric for the best city ranking above. As Ilukwe explained in an email to me, "The best city was determined as a result of an experiment in which the EIU opened their city ranking and cost of living data to the world (public) and invited people to compile a new city index." The winner of the contest was Filippo Lovato, from Italy, who came up with the Spatially Adjusted Livability Index. And here's the latest livability index from EIU .

Photo: Flickr/xopherlance

More cities lists on SmartPlanet:

More smart cities posts:

This post was originally published on Smartplanet.com