Marshes, reefs, beaches can bolster coastal resilience: NOAA
“Coastal resiliency and disaster risk reduction have become a national priority, and healthy coastal ecosystems play an important role in building resilient communities,” said Holly Bamford, Ph.D., acting assistant secretary of commerce for conservation and management at NOAA, and co-author of the study. “We know that sea levels are rising and that coastal communities are becoming more vulnerable to extreme weather- and climate-related events. Now is the time to invest in protection to secure our coasts, but we need to make those investments wisely and with a full understanding of the costs and benefits of different approaches.”
The study points out that there is still a need for built approaches in some locations. However, natural or hybrid approaches can be used in many cases.
Some natural ecosystems can maintain themselves, recovering after storm events and reducing the cost of upkeep. Natural habitats such as coral reefs, marshes and dunes can act as buffers for waves, storms and floods. Natural ecosystems also can, in many cases, keep pace with sea level rise, while built infrastructure does not adapt to changing conditions.
“There is a lot of potential innovation with hybrid approaches,” said Katya Wowk, Ph.D., NOAA senior social scientist, and the third co-author of the study. “Hybrid approaches, using both built and natural infrastructure, often provide more cost-effective flood risk reduction options and alternatives for communities when there is not enough space to use natural coastal protection alone.”
Hybrid approaches, such as combining some habitat restoration with openable flood gates or removable flood walls, provide benefits while also providing more storm and erosion protection than natural approaches alone. The study highlights hybrid approaches in the New York City metro area and in Seoul, South Korea, to deal with their monsoon flooding events.
“One of the challenging aspects is that these approaches are very new, so we are still learning what works best in which situations and under what circumstances,” said Wowk.
The authors suggest that every location where hybrid and natural approaches are being implemented provide opportunities for monitoring so we can learn as much as possible about each approach, including longer-term cost effectiveness.
“There is no ‘one size fits all’ solution when it comes to what is best for a community in providing coastal protection from flooding,” said Bamford. “We all have to work to innovate, test, monitor, and develop a better suite of options that includes more natural and hybrid infrastructure alternatives for providing coastal protection to communities around the world.”
— Read more in Ariana Sutton-Grier et al., “Future of our coasts: The potential for natural and hybrid infrastructure to enhance the resilience of our coastal communities, economies and ecosystems,” Environmental Science & Policy51 (August 2015): 137-48 (doi:10.1016/j.envsci.2015.04.006)
