Supporting Nature-Based Solutions in Cities

The International Union for the Conservation of Nature (IUCN) defines Nature-Based Solutions (NBS) as “actions to protect, sustainably manage, and restore natural or modified ecosystems that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits”. As cities worldwide are increasingly exposed to the effects of climate change, biodiversity loss and rapid urbanization, this concept has gained growing importance in recent years.

Nature-Based Solutions aim to bring ecosystem services back into urban environments while improving quality of life for citizens. Solutions can broadly be categorised into “blue” and “green” infrastructure, while some approaches also target “gray” infrastructure such as energy-efficient buildings. Examples include the reintroduction of urban forests, wetlands, green belts and parks in and around cities. Linking green roofs, green walls, neighborhood parks and ecosystem corridors into a connected network can help reduce urban heat islands, manage stormwater runoff, improve air quality and sequester carbon while providing much-needed habitats for flora and fauna. 

Earth Observation helps planners identify areas of greatest need and monitor the impact of interventions over time. Urban green areas can be mapped and categorised at high spatial resolutions. Urban heat islands can be identified and paired with socio-economic as well as Population Density data to identify areas where urban greening campaigns will have the most equitable impact. Vegetation Indices, in combination with very high resolution Digital Surface Models and Building Footprints, can be used to identify and monitor green roofs. Similarly, once areas such as wetlands have been designated as urban habitats to be preserved or restored, they can be monitored from space, providing policy-makers, civil society and the public with an objective measure of how well policies in favour of Nature-Based Solutions are being implemented.