Nature to the rescue: Using ecosystem services to reduce flood risks
From the mouth of the Mississippi to that of the Nile, communities have been drawn to coastal flood plains throughout the centuries. Where rivers and oceans meet, nature is at its best, and river sedimentation provides rich soils that greatly benefit agricultural productivity as well as fisheries. At present, an estimated 60 percent of our global population lives along estuaries and coastlines – making them among the most heavily populated areas of the world.
As appealing as coastal areas are, living on a fertile floodplain comes with substantial risks. Floods are the most frequent of all natural disasters globally, and some of the largest disasters have occurred in coastal areas. Think about the devastation done by hurricane Katrina in New Orleans or the dangerous floods that happen every year in Bangladesh.
The country where I was born, the Netherlands, is built on a massive flood plain and extremely exposed to the forces of the sea. Realising the vulnerability of its population, the Dutch Government developed the Zuiderzee Works and later the Delta Works. Including dams, dykes, and massive storm surge barriers, the works are so impressive they were declared as one of the Seven Wonders of the Modern World. But, while heavy infrastructure can be useful in protecting coastal populations from the forces of nature, it is not necessarily the best and most cost-effective solution.
Over the past decades, there has been a growing realisation that mother nature herself sometimes offers much better solutions. Concepts such as nature-based solutions, ecosystem-based adaptation or green infrastructure are increasingly accepted as alternatives or complement traditional infrastructure to provide flood protection.
Nature-based approaches can generally be defined as working together with nature rather than against it. More specifically, these approaches aim to protect, sustainably manage, and restore ecosystems to address societal challenges (such as climate change, water or food security, and disaster risks), simultaneously providing human well-being and environmental benefits.
Nature-based approaches are also cost-efficient and allow for flexibility in dealing with a constantly changing climate.
In the Netherlands, building with nature is now an increasingly popular concept, and solutions such as restoration and protection of wetlands, mudflats, and natural dune systems are often preferred for flood risk reduction. A growing number of countries across the world is realising the benefits of protecting coral reefs and mangrove forests as important areas for marine biodiversity as well as crucial buffers between land and sea.
At UNDP, our Ecosystem-Based Adaptation portfolio includes over US$ 355 million of investments by the Global Environment Facility, Green Climate Fund, government co-financing and other funding sources to support developing countries to address the adverse impacts of climate change using nature-based solutions.
In Bangladesh, we successfully supported coastal communities to reduce their vulnerability to floods through afforestation while simultaneously generating income opportunities through sustainable forestry, agriculture, and aquaculture.
In Sierra Leone, where over 3 million people live in increasingly vulnerable coastal areas, we helped the Government take an integrated approach to managing risks in the face of climate change, by protecting coastal habitats and incorporating scientific data in decision-making processes.
In the Kingdom of Tonga, which consists of 169 Pacific islands that are extremely vulnerable to sea level rise and flooding from storm surges, we are working together with research institutions and the Government to protect communities through a combination of infrastructure and nature-based solutions. This includes restoration, rehabilitation and management of coastal ecosystems as part of a Ridge to Reef approach, through coastal habitats and lagoons to fringing coral reefs.
With climate change, continuing urbanization trends and demographic growth – especially also in coastal areas, the impacts of floods are expected to increase dramatically in the next decades. Finding innovative and sustainable ways to work together with rather than against nature for effective flood risk reduction will be critical.