Town planning and city maintenance are areas of endeavour dominated by engineers, so it’s hardly surprising that coastal communities under threat from storms resort to building big walls, levees and flood barriers to dampen their impact.
Research coming out of the University of California San Diego (UCSD), however, suggests that at least for towns in warmer areas wetlands offer better protection than sodding great lumps of concrete.
A team led by Fanglin Sun – who has since moved on to take a position with Amazon – looked at damage sustained in US districts subject to hurricanes and tropical storms over a 20-year period.
All up, they analysed at the destructive effects of 88 hurricanes and storms that smacked into 232 counties between 1996 and 2016.
The results revealed that areas with more wetlands experienced substantially less damage than those with very little.
Sun, like her senior author Richard Carson, also of UCSD, is not an engineer, still less an ecologist, but actually an economist. She and colleagues estimated that the average value of just a single square kilometre is $1.8 million per year. That value increased considerably for wetlands surrounding urban areas.
The figure was based on the amount of storm damage to built structures each square kilometre prevented, and did not include other types of value, such as that derived from tourism or recreation.
“Wetlands play a critical role in helping to reduce property damage from storms,” says Carson.
“With coastal areas under increasing threat from more powerful storms due to climate change, it’s critical to prevent further destruction of existing wetlands. Government should also actively seek to restore wetlands that have been lost.”
Cynics might suggest that local authorities keen on fostering rateable development along coastlands might be more amenable to the idea of wetland restoration now that Sun and her team have put a hefty dollar value on the benefits of doing so.
The research, published in the journal PNAS, encompassed fresh and saltwater wetlands, including mangrove forests and scrub zones. Storm damage buffering was consistent throughout.
Sun, Carson and colleagues suggest their analysis can form a coherent basis for development policies in suitable regions.
Barry Keily is a science journalist based in Victoria, Australia.
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