Examples of nature-based solutions at different levels of a catchment area
© BRGM - Adrien Selles
The philosophy underlying the wide range of nature-based solutions is “to work with nature rather than against it”.
Nature based solutions are emerging as an effective response to the challenges posed by climate change, particularly in terms of managing groundwater, preventing coastal risks and combating run-off and soil erosion. These techniques, integrated into national and international strategies, rely on ecosystem services to deliver both environmental and societal benefits.
Their use raises specific issues that are crucial to several multidisciplinary projects conducted by BRGM.
Reducing run-off and soil erosion
Since the 1960s, changes in land use have led to an increase in run-off and erosion, particularly with the intensification of agriculture and growing urbanisation. The removal of hedgerows, the draining of wetlands and the sealing of soil have accentuated these phenomena, which have been aggravated by the increase in extreme rainfall events related to climate change.
Faced with these risks, public policies since the 2000s have encouraged the deployment of NbSs in the form of hedges, fascines, grassy strips or buffer ponds, in addition to traditional structures (dykes, ponds). Agro-ecology also offers essential levers, with practices such as reduced tillage and crop diversification aimed at sustainably reducing run-off and erosion.
Better management of groundwater
Global warming, combined with urbanisation, is leading to a reduction in aquifer recharging and an increased threat of saline intrusion into coastal aquifers. Some NbSs that are adapted to local characteristics (climate, vegetation, geology) help to maintain the quality and availability of water resources. They encourage the infiltration of rainwater, reduce the risk of flooding and help replenish watercourses in times of drought.
Adapting coastal development
In the face of coastal erosion and flooding, strategies based on massive structures (dykes, rip rap) appear to have limited effectiveness. Coastal ecosystems such as marshes, mangroves, reefs and sea grass beds, as well as dunes, play an essential role in mitigating the impact of storms and storing carbon. Initiatives are emerging to restore these environments and integrate NbSs into coastal development policies, particularly in the most vulnerable areas, such as the Caribbean.
A change of paradigm for greater resilience
The adoption of NbSs requires a multidisciplinary approach combining geoscience, ecology and social sciences to ensure their effectiveness and local acceptability. Demonstrators are essential to validate the effectiveness of these solutions and adapt them to the specific challenges of the regions concerned.
By promoting the sustainable management of natural resources, NbSs offer realistic prospects for strengthening the resilience of territories in the face of climate change, while supporting biodiversity and human well-being.
Cover and extract of issue 28 of the Géosciences journal.
© BRGM
Géosciences No. 28: How can we adapt to climate change?
Adapting to climate change means learning more about its consequences. This issue of BRGM's Géosciences journal takes stock of the research being conducted in this field and the solutions that are emerging.
Moreover, BRGM is a key player in this field, providing expertise to support decision-making by the State and local authorities, notably concerning the issues of coastal erosion, monitoring aquifers and understanding clay soils.
