'Smellscapes' mapping the whiffs of the town and city

The smell of an overflowing rubbish bin is complex and, to the aficionado, quite delightful.

"I'm actually getting a lot of the cardboard, over and above the other smells of the rubbish," says Kate McLean, as she inhales deeply from a dumpster on the Margate promenade.

It's filled with fish and chip wrappers, beer cans, fag ends and cardboard boxes.

"But inside the fish and chips - there's definitely a lot of odour coming from that. Not so much of the fish, but just the vinegar and fat that linger," says Ms McLean.

She beckons me over to sniff with her.

"There's definitely more trash juice down in that bit," she says. "It's not necessarily as bad as you think it would be."

It is.

"Most of the time I get people to sniff bins and it's not so bad," she adds. "It's the smell of the party people had the night before."

Ms McLean is a lecturer in graphic design at Canterbury Christ Church University. Her topic is mapping the smells of a city - what she calls "smellscapes".

Along with other researchers, she's seeking to quantify the ephemeral and subjective aspects of urban places.

"A smellscape is the olfactory equivalent of a landscape," she says.

"We spend most of our time walking around, we see things and we take about 80% of our information from that. But we've got four other senses, all of which contribute.

"And smell's one of those senses that we pay very little heed to, but forms a huge part of how we absorb and how we know the world."

Ms McLean has created smell maps of cities including Edinburgh, Singapore, and, most recently, Kiev.

She asks locals about the smells that mean most to them, then plots them geographically.

She's doing the same for Margate. Thankfully, it's not all rubbish bins, as interesting as their bouquets may be.

We stop by a shop and bury our noses in the candyfloss machine, slowly spinning: an intense, burnt sugar.

She makes me sniff a rack of postcards: redolent of the seaside, says the smell expert. Then a pub, an oyster stand, and down to the beach, where we hold kelp to our noses and breathe it in.

Ms McLean's method is intimate and small scale. Daniele Quercia, a researcher at Nokia Bell Labs in Cambridge, is doing something similar, but on a massive scale.

Instead of going on smell tours, he harvests data from social media - not just for smell, but sound too - and feeds them into algorithm he has created.

"It takes data from social media - typically pictures from Flickr for example. And you know when you upload a picture of a car and then you might ID the car.

"That car is a tag related to traffic sounds so we can take all those tags. In London, actually, you have one billion of these tags.

"And then you can match the vocabulary we have for sound with the picture tag have and then you can map the entire soundscape of the city."

The result is detailed maps on a huge scale: Click on a street to see how it smells.

Mr Quercia is looking to go beyond smell and sound for his next project - he wants to map ambiance; how arty or blue collar a neighbourhood is, say.

He's carrying out a survey at goodcitylife.org.

His ambition is esoteric and at odds with current research into technology and cities.

Most work now, he says is, into the "smart city. They are all about efficiency. It is about safety and security".

"But we know that we don't choose the best city to live in because of these problems," says Mr Quercia.

"These are important and make a city acceptable but they don't make it great.The whole point of this research is to explore those things that make a city great."