Extreme storms could help protect beaches from sea level rise, new study finds

Images in the wake of violent coastal storms usually focus on the damage done to beaches, dunes, property, and surrounding infrastructure.

A new international study has shown that extreme weather events can help protect beaches from the impact of sea level rise by bringing in new sand from deeper waters or nearby beaches.

The study is published in Nature Communications Earth and Environment.

Dr. Harley says that extreme storms cause major coastal erosion and damage to beachfront properties.

For the first time, we looked not just above water, where the impacts of extreme storms are easy to see, but also deep down below the water as well.

The scale of what engineers use to nourish a beach artificially was similar to the amount of sand that was entering these beach systems during these events.

Some of the impacts of sea level rises caused by climate change, such as retreating coastlines, and by several decades in the long-term could be mitigated by this.

It is a new way of looking at storms.

Wave after wave.

The study looked at three coastlines across Australia, the United Kingdom and Mexico. Each was 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217

In Australia, researchers studied Narrabeen beach after a storm ripped a swimming pool away from a property overlooking the coastline.

They were able to show that the gains from the beach were enough to offset decades of shoreline retreat.

For the first time, we were able to mobilize specialized monitoring equipment to get really accurate measurements before and after a storm.

We used a twin engine airplane with a Lidar scanner, drones, and jet skis to go back and forth along the beach taking measurements before and after the storm hit.

This was how we were able to get an accurate picture of the volume of sand moving.

The Perranporth beach in Cornwall has been studied by the researchers of the Coastal Processes Research Group of the University of Plymouth since 2006 using a combination of monthly beach surveys and bathymetric surveys.

The intertidal beach and dune system lost a lot of sand due to the extreme winters of 2013/14 and 2015/16. The beach gained 420,000 square meters of sand by the end of the year.

We don't know if this extra sand has come from offshore or from around the corner, but we do know that extreme waves can potentially contribute to the overall sand budget, despite causing upper beach and dune erosion.

The rule of bruun.

The question of how much a coastline will change due to sea level rise is a key one facing coastal managers.

The Bruun rule has been used to estimate this in the past. The coastline is expected to retreat between 20 and 100 meters depending on the steepness of the coast.

By the end of this century, global sea-level rise caused by climate change is projected to result in a large retreat or loss of almost half of the world's sandy beaches.

Prof. Masselink says that the Bruun rule doesn't take into account the many complex factors about how individual beaches respond to sea-level rise.

This includes the presence of sand stored in deeper water immediately off the coast and its potential to be mobilized during extreme weather events.

Dr. Harley says that extreme storms need to be considered in long-term projections of the movement of sand on the beach.

As global sea-level rise continues, we really need to be doing a beach-by-beach understanding of how our beaches are going to change.

Looking past the storm.

Dr. Harley says it is hard to tell how much sand will be used in the future because there are so few measurements of the seabed immediately off our coastlines.

The long-term future of our coastlines could be changed by the findings from only three storms.

We are only looking at the surface. He says that we need to repeat these types of monitoring for more storms and different types of coastal settings.

Only then will we be able to understand how much sand is stored off the coast that could potentially help buffer the impacts of sea level rise.

More information: Single Extreme Storm Sequence Can Offset Decades Of 2 Shoreline Retreat Projected To Result From Sea-Level Rise, Nature Communications Earth & Environment (2022). DOI: 10.1038/s43247-022-00437-2 , www.nature.com/articles/s43247-022-00437-2 Journal information: Nature Communications Earth & Environment Citation: Extreme storms could help protect beaches from sea level rise, new study finds (2022, May 12) retrieved 12 May 2022 from https://phys.org/news/2022-05-extreme-storms-beaches-sea.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.