All hail the humble salt marsh in the fight against flooding

Salt marshes are often unloved and overlooked muddy stretches along coasts but they are unsung heroes helping to protect the shore from flooding and erosion as sea levels rise and storms grow worse, much of that driven by the warming climate. They are particularly effective at defending against extreme storms, when water levels reach their maximum and waves are at their highest. Most commented 1 US withdraws diplomats from Saudi Arabia amid deadly Houthi attacks US news 203 comments In an ambitious project, researchers cut out a 40 metre-long chunk of natural salt marsh and recreated it in Hanover, Germany, at a huge wave tank — one of the largest in the world — then pummelled it with artificial waves and rising water depths typical of storm surges.

The marsh proved to be a natural barrier that acted as a shock absorber, taking the energy out of waves and reducing their impacts. Even when waves tore into the marsh vegetation, the soil under the plants withstood the pounding and remained stable. The marsh still helped prevent erosion when the plants were hit hard enough to flatten them. The results highlighted the important role salt marshes play as natural barriers against storms, alongside artificial barriers such as flood walls.

Top stories 1 Tripsnacking? Finally a travel trend I can get on board with Advice “We have long known that salt marshes and other natural defences such as sand dunes or mudflats can help protect our coastlines, a lack of data on their effectiveness in extreme conditions has meant that they often are not included in flood risk assessments,” said Dr Iris Möller, a co-author of the study. “But we’ve shown that even in extreme conditions, salt marshes are a vital defence for our coastlines and protect against more frequent storms.”

The need for these natural defence was highlighted in the flooding that hit southwest England last winter when 12 storms struck large parts of Cornwall, Devon and other parts of the region, flooding businesses, railways, roads and farmland, and while on the Somerset Levels high waters forced many families to evacuate their homes. Advertisement With storms expected to grow worse in the future, salt marshes are being recreated at several locations around the UK’s coastline.