Blue-green networks generally refer to an urban space development concept defining a network of existing and/or restored rivers and their valleys (blue areas) and green areas (agricultural areas, parks, old orchards, wastelands, degraded areas and others), as a basis for the spatial planning of cities that will provide sustainable development and adaptation to global climate change. The network aims to create or preserve key ‘reservoirs’ for biodiversity and to link these through ecological corridors vital to the free movement of species. Blue-green networks can range from small-scale endeavours to all-encompassing city plans.
Recreating a nature-oriented water cycle and combining water management and green infrastructure through blue-green networks is an efficient way to provide habitats for flora and fauna, improve the quality of the cities, mitigate the effects of climate change and improve air quality, and it can also have a positive impact on the economic development of a city.
There is a series of measures that can be combined in the construction of efficient blue-green networks within cities, for example:
- creating buffer zones around the green areas and rivers that protect and maintain the ecological processes within the network while minimising the conflicts between potentially incompatible land uses
- regenerating and connecting remaining natural spaces in the city
- implementing protection systems to ensure that natural spaces are preserved
- creating areas for storm water management (e.g. biofiltering systems, constructed wetlands, river rehabilitation, reservoirs with increased capacity due to phyto-technology applications, etc.)
- establishing alternative transport for the public and individuals by providing space for cycle routes, pedestrians and trams.
The idea of a network is vital as it recognises the importance of corridors for the enhancement of biodiversity, and it can also be linked to other urban networks such as the transport network, providing extra added value to policies related to mobility. For more details, see fostering cycling and walking through cycling infrastructure, bike-sharing schemes and promotion of walking.