Building safety with nature: Salt marshes for flood risk reduction

Flood risk reduction in coastal areas is traditionally approached from a conventional engineering perspective, where dikes and dams are built to withstand the forces of tides, surges and waves. Recently, a nature-based approach to flood risk reduction is increasingly promoted, in which the benefits of coastal ecosystems for reducing the impact of extreme weather events are utilized. Ecosystems such as salt marshes, mangrove forests, coral reefs and sand dunes are preserved, enhanced or even created, in order to reduce flood risk in coastal areas. Nature-based flood defenses can work stand-alone, like sand dunes, but can also function in combination with engineered defenses, for example when vegetated foreshores reduce wave loads on dikes or dams.