Urban Green and Blue Infrastructures
The importance of nature in the protection of urban fabric.
In urban areas, the elements of the natural environment providing ecosystem services are usually referred to as green infrastructure, or green and blue infrastructure if they include water bodies, rivers, ponds, or other water related areas.
These form a network of natural and semi-natural areas that contribute to the ecological, social and economic health of urban areas. They include such things as parks, playing fields, cemeteries, allotments, private gardens or street trees, as well as urban interventions like green roofs, green walls or sustainable urban drainage systems, not forgetting ponds, rivers or canals.
Although green and blue Infrastructure planning is increasingly recognized not only as a valuable but also a fundamental approach for spatial planning, existing urban green and blue infrastructure in most countries has not been strategically planned to deliver ecosystem services.
Globally, these ecosystems are under threat, with 60 percent experiencing worrying declines. In 2012, more than 3 quarters of the European habitats (77 percent) were considered degraded, showing an increase in 65 percent since 2007, no longer able to deliver the optimal quality and quantity of basic services such as crop pollination, clean air and water, or the control of floods or erosion.
On average, more than half of the world population is already living in cities. By 2050 this number is expected to increase up to 70%. But the number is much already higher in Europe, northern America and Latin America, where up to 4 in each 5 persons live in urban areas. The need for resilient and healthy ecosystems, contributing towards biodiversity and human wellbeing, is particularly pressing in urban contexts, where the highest population densities are coinciding with highest environmental impacts.
Cities are complex socio-ecological systems and the demand for - and use of - ecosystem services are diverse and context-dependent. Strategically planned green and blue infrastructure can be designed and managed in the cities to deliver a wide range of ecosystem services. This network of green and blue spaces can improve environmental conditions and therefore contribute towards citizens' health and quality of life.
