The sounds of the (green) city

Sounds are an integral part of our urban nature experience: the sound of water, birds singing, wind rustling in the trees, people talking, and cars driving by. The urban soundscape is a central element of a study into people’s experience of the local environment in the Kalasatama and Kuninkaantammi neighbourhoods in Helsinki.

Nature-based solutions for liveable cities

“Kalasatama and Kuninkaantammi are two rapidly developing but very different neighbourhoods,” says Silviya Korpilo, postdoctoral researcher at the University of Helsinki. “While Kalasatama has become emblematic for its smart-city initiatives, the development in Kuninkaantammi is more focused on the green city and nature-based solutions in urban planning.”

The population of Helsinki is projected to grow from 660,000 in 2021 to almost 900,000 in 2060, and the two localities are among the city’s most important development sites. Around 5,000 people currently live in Kalasatama, and by 2040, it will be home to approximately 25,000 people. The study is part of SMARTer Greener Cities, a project funded by NordForsk through the Nordic programme for sustainable urban development and smart cities.

“We’re exploring the links between the social, ecological and technological aspects of urban planning and sustainable development,” Korpilo explains. “We aim to inform better smart-city development and promote urban planning that gives more emphasis to nature-based solutions.”

Extensive mapping of green infrastructure

The researchers have conducted a detailed mapping of the areas’ green infrastructure, including vegetation, water areas and green roofs, and analysed the socio-economic composition of the two neighbourhoods. According to Elina Nyberg, researcher at the Finnish Environment Institute, what is interesting to see is how the tree stands and vegetation have changed during the construction and development period.

“Kalasatama is an old industrial harbour area, where there was very little vegetation in the first place,” says Nyberg. “The neighbourhood’s green structure is mainly centred around Mustikkamaa, a naturally green island next to the site, and a ruderal site in Verkkosaari. The latter is a hybrid green space, meaning that it was initially shaped by humans but is now left to grow naturally. Apart from these two areas, the green structure in Kalasatama consists mostly of newly built parks, green corridors and green roofs.”

Kuninkaantammi’s history is entirely different. The area is a former industrial brownfield and woodland alongside Keskuspuisto, Helsinki’s Central Park, a large, forested area that starts in the city centre and continues to the Vantaanjoki river in the northern part of the city. Except for a few public parks, remnant forest still makes up most of the area’s green structure.

“Looking at the change during the past few years, it’s not surprising that the tree stand has slightly decreased due to the ongoing development,” says Nyberg. “On the other hand, low vegetation is increasing as more parks, green areas and gardens are being established.”

Sound as an urban resource

One thing that distinguishes the SMARTer Greener Cities project’s research in Helsinki from other similar projects is its focus on the sounds of the city. The urban soundscape was a prominent topic in a PPGIS survey conducted in the two neighbourhoods.

“The respondents could map out aesthetic outdoor environments and places they associate with, for instance, nice city life, biodiversity, restorative views, and pleasant or unpleasant sounds,” Korpilo explains. “Whereas previous studies have focused mainly on noise from traffic or construction, we’re studying the soundscapes as an urban resource.”

The survey shows that residents in both neighbourhoods highly appreciate the local green infrastructure. This was particularly the case with the forest areas in Kuninkaantammi and the larger parks within or nearby the study areas, notably in Mustikkamaa. Moreover, Korpilo and Nyberg emphasise the importance of water elements – the ocean in Kalasatama and the river in Kuninkaantammi.

Not surprisingly, natural sounds were often associated with pleasant urban life.

“The urban soundscape is a mixture of different sounds; human sounds, sounds from traffic and construction, and natural sounds in the background,” says Korpilo. “For many, this mix actually produces a similar effect to natural sounds, particularly if none of the sounds is too dominant. Our data brings more depth to the understanding of how sound affects people’s perception of the urban environment.”

Restorative benefits of urban nature

Furthermore, the research team has investigated the impact of urban green spaces on psychological restoration. The insight was gathered by monitoring a group of volunteers and registering their mental and physical reactions to different green and blue areas.

“We use long-established research methods to measure psychological restoration and stress relief,” says Korpilo. “Combined with modern technology, these methods allow us to accurately measure the level of stress and arousal in different environments.” “The research within the SMARTer Greener Cities has produced a better understanding of what people appreciate the most when it comes to urban nature, how they use it, and what type of urban green spaces are the most restorative,” Nyberg concludes. “These perspectives provide valuable input into the planning of our cities and green spaces.”

Related articles