Sometimes, the solution to a problem can be lying right under our nose. Dunes serve as natural buffers to climate change, for instance, by breaking the strength of the wind and waves that can cause erosion and damage coastal infrastructure. That is why UNESCO began working with scientists, local management committees and the wider population four years ago to restore coastal areas in the Po Delta Biosphere Reserve in Italy. This was one of the many case studies discussed at an international conference hosted by UNESCO headquarters in Paris on 13-16 December on the theme of nature-based solutions for hydrometeorological risks.
The conference marked the end of a project funded under the European Union’s Horizon 2020 framework and involving UNESCO which had used research and innovation between 2019 and 2022 to highlight the many ways in which nature-based solutions could reduce environmental risks in rural areas. The project was named OPEn-air laboRAtories for Nature baseD solUtions to Manage hydro-meteo risks (OPERANDUM).
Researchers used sites across Europe which they called ‘open-air laboratories’ to demonstrate the importance of taking an inclusive approach that acknowledged the need to involve diverse stakeholders and combine scientific knowledge with local and indigenous knowledge.
This is where UNESCO’s own designated sites proved an invaluable source of information. For instance, UNESCO is currently restoring mangrove forests in seven biosphere reserves in Latin America and the Caribbean. ‘We need look no farther than nature for the solution to many of our problems’, observes Noëline Raondry Rakotoarisoa, Director of the Division of Ecological and Earth Sciences at UNESCO.
91Â鶹¹ú²ú¾«Æ·×ÔÅÄ more than 2,000 designated sites around the world, which cover about 6% of the Earth's land surface. This network is constantly expanding. These sites and territories – some of which cover 1 million hectares or more – have in common that they set out to strengthen the links between cultural and natural heritage and reinforce both social inclusion and gender equality.
A relatively new concept
The term ‘nature-based solutions’ is still a fairly new concept. The United Nations Environment Assembly only defined this term in September 2022. That is why the December conference offered a timely opportunity to establish a common understanding of how to leverage nature-based solutions around the world and overcome the regulatory and policy barriers to their implementation.
The December conference attracted a wide range of participants: international policy-makers from UNESCO and representatives of the European Commission, United Nations Office for Disaster Risk Reduction and the International Union for Conservation of Nature. Project leaders from OPERANDUM attended but also senior researchers and project leaders from other EU-funded projects.
Putting nature-based solutions into practice
One of the case studies participants discussed concerned Catterline Bay in the United Kingdom, where houses sit atop the sea cliffs. The area around Catterline Bay is subject to shallow landslides, and the cliffs’ slopped topography makes it particularly vulnerable to coastal and surface erosion. Within the OPERANDUM project, UNESCO reinforced the soil by planting vegetation on the cliff to reduce the amount of run-off from falling rain and snow. UNESCO consulted both local and national stakeholders, in order to co-design the solution with them. Since vegetation takes a while to grow, temporary structures were engineered to anchor the soil in the meantime. Over the next five years, plants will grow over these structures, eventually hiding them. In parallel, the project built a cribwall at the base of the sloping cliff out of timber, soil and plant cuttings or saplings. This retention wall provides stability and will gradually be covered by vegetation.
This double live cribwall was co-created by nature-based solution experts and a local farmer in Scotland during June 2021. Built using locally available vegetation, the cribwall acts as a retention wall, protecting slopes against landslides and erosion.
Live ground anchors are a passive and immediate erosion protection system and soil reinforcement, consisting in an engineered anchored grid, supplemented with natural sustainable materials. The main objective is to construct a temporary structure that will support the vegetation growth for a period of time.
A second case study concerned the Bellocchio and Volano Beaches in Italy’s Po Delta Biosphere Reserve, where storm surges are causing the sea to flood the lagoon, threatening the freshwater ecosystem and its biodiversity, including inland fish farms. UNESCO worked with local stakeholders to design a solution, implement it and monitor the result. It was decided to build artificial dunes using sand, wood and coconut fiber. Unlike a seawall, dunes are dynamic, constantly changing in shape and location in response to changes in the wind.
The Velano Beach, Po Delta UNESCO Biosphere Reserve, in Italy is strongly affected by marine erosion. An artificial dune has been constructed using natural materials. It serves as a 'dynamic' structure that can adapt to the small adjustments made by the wind and wave action.
