Green Infrastructures

The quality of (green) infrastructures is important to be able to cope with growing urban challenges.

An urban area is a densely populated piece of land, where inhabitants use natural resources like water, soil and air intensively. The higher the density of an urban population, higher is the resource use. Additionally, the several negative effects of intensive resource use come into play: such as loss of biodiversity, air pollution, loss of green spaces, pollution of surface and ground water, shortage of drinking water sources and creation of unfavorable microclimate conditions (e.g. Urban Heat Islands). We also know that  natural resources are limited and getting scarcer by the day, which means we have to manage them carefully to be able to satisfy the needs of urban population in a long term. Another fact to bear in mind is the growing urbanization observable at a global scale.

The combination of all these factors have made us rethink our notions of resource use, and rightly so. Consequently, there have been a number of innovations  in the development and use of urban infrastructure. Emerging across a number of years and a variety of urban contexts, these innovations have collectively highlighted some key concepts that bind them together. One of these key concepts is that of multifunctional infrastructure.

The rationale for infrastructure that perform various functions draws from the multiple challenges that modern urban development is faced with: lack of resources, loss of biodiversity, demographic pressures, pollutions… and so on. Multifunctional infrastructure enables us to increase the efficiency of resource use, while simultaneously improving the quality of urban environment. Given the centrality of ecological/ sustainability concerns in the urban context, discussions on multifunctional infrastructure in cities is invariably framed from the perspective of Green Infrastructure.  

With around 80% of EU’s population now living in towns or cities, and with the spectre of climate change looming large, taking care of the vital green infrastructure that connects and breathes life into urban and rural habitats has never been more important. In response, a number of green cities have come up; one of their key characteristics is that Green Infrastructure forms their very basis.

The following video examines two main Green Infrastructure projects based in Europe:

• The UrbanBees project in Lyon (France) which is designed to halt a decline in the wild bee population that threatens agriculture and the environment;
• A Natura 2000 site in Latvia which aims to protect endangered species such as the fire-bellied toad and the European smooth snake.

Green Infrastructures embed the natural, semi-natural and artificial networks of multifunctional ecological systems within, between and around urban areas.Threy have the potential to improve urban development, nature conservation and public health. Specifically, they provide multiple ecosystem services such as recreation, habitat creation/preservation, climate change adaptation (flood protection and microclimate control), and cultural and spiritual wellbeing. In addition, they make a strong link between ecology and the urbanization process. They can also contribute to biodiversity conservation and protection of water resources. Examples include green roofs, blue roofs, living wall systems, green facades or vertical gardens, water harvesting road system, water harvesting roof system, butterfly roundabouts and green sound protection walls.

Green Roofs are fully or partially covered with a layer of vegetation. They provide a variety of environmental benefits and strengthen  ecosystems in urban areas. They also improve storm-water management, regulate better building temperatures, reduce urban heat-island effects, increase urban wildlife habitat and enhance architectural interest. Here is a video that illustrates some of these points:  

It is important to point out that  green roofs (and the use of lighter-colored surfaces in urban areas) reflect more sunlight and absorb less heat helping to mitigate the urban heat island effect in some cities. 

Vertical greening (green facade,vetical gardens, green walls)  combine aesthetic design with a number of ecological and performance benefits:

The largest vertical garden in Europe is located in Tarragona (Catalonia): it covers 3,200 square meters and one of its strong points is water administration.

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