The world is urbanizing, the world’s megacities do not stop growing attracting people to urban areas. Consequently, urban environments have been gradually denatured, the artificialization and waterproofing of the soil begin to cause problems in urban areas. Currently, challenges such as climate change, environmental quality, access to food and water and others of a natural nature are taking place all over the world. These challenges affect especially in urban environments, normally denatured. The metropolitan areas of Euskadi have also suffered the process of artificialization of the land together with urban expansionism.

The Basque Government includes the main impacts of the artificialization of the soil that are manifested in the Basque Country, which are:

  • The fragmentation of the territory and the loss of biodiversity.
  • The irreversible loss of fertile soils, since due to its mountainous topography and settlement pattern, the areas preferably artificialized are located in the Basque Country at the bottom of valleys.
  • Climatic impact (significant increase in temperature in artificial areas compared to non-artificial ones).
  • The occupation of the basins and of the Hydraulic and Maritime-Terrestrial Public Domains, as a consequence of which there is an increase in the flows of river courses, as well as the risk of floods and the probability of these originating catastrophic consequences.
  • Various effects on the water system (interception of surface-ground water flows, etc.)

There are two solutions to the problem of artificialization. On the one hand, reduce consumption and demand for natural land and on the other naturalize urban land. For this, cities and their inhabitants have to prepare themselves, before problems of a natural nature, such as climate change, the solutions must be based on nature. Therefore, urban societies must open the door to Nature, historically confined to the rural world. To this end, Nature-based Solutions (NbS) present keys in the (re-)naturalization of cities. Paris has already called on the public to revegetate the city and has granted more than 2,000 permits for revegetation in three years.

The incorporation through NBS of green and blue infrastructure in cities provides benefits for the physical and mental health of citizens. It also helps adaptation and mitigation of climate change and contributes to greater urban resilience. Among other benefits:

  • Reduces the impact of heavy rainfall on a fixed-capacity storm sewer system.
  • Reduces the impact of extreme heat on gray infrastructure and human health.
  • Provides services that can better recover after extreme weather events.
  • Provides essential food and habitat for birds and pollinators.
  • Provides spaces for recreation, recreation and healing.
  • Increases connectivity between larger natural heritage features, such as forests and wetlands.