With global warming accelerating at an alarming pace, glaciers and ice sheets melting away, resulting in a rapid rise in sea levels. Today, sea levels show rise annually by 1/8th of 1", resulting in wide-spread coastal erosion & flooding.
Did you know, a complete meltdown of the Greenland ice-sheet is expected by 2100? This event will lead to a massive sea level rise up to 23 ft that would be significant enough to submerge the whole of London!
Coastal erosion and flooding are just two consequences of rising sea levels. A deeper look into the matter reveals more about the terrifying impacts of an elevated ocean level, including contaminated drinking water, destruction of marine life etc.
Thankfully, engineers are hard at work on intelligent coastal management techniques that can prevent erosion & flooding from heightened sea levels. Let's have a look how coastal engineering is working to save cities from rising seas.
Revetments are concrete structures constructed along a cliff base. Sometimes they are wooden built and positioned at an angle to form a strong barrier against raging waves. As elevated waves hit these structures, they absorb the aquatic energy and mitigate much of the risk of erosion on shorelines. Sometimes, revetments are modified with ribbed surfaces that are more effective in dissipating wave energy.
One of the most common techniques used in coastal engineering to save cities from rising sea levels is the construction of sea walls. Although sea walls have been in use for decades, recent developments in coastal engineering have led to a new evolution of smarter, modernized walls utilizing an optimized, curved structure. The curved contour is better equipped than old flat walls to reflect elevated waves back to the sea and reduce their impact on the shoreline.
Offshore walls made of concrete, breakwaters break down the incoming waves at sea to reduce their erosive strength exponentially as they hit the coast. These structures are proven to be effective but are prone to failure in the face of raging storms & hurricanes.
A major part of coastal management is effective land management. Primarily, this management involves safeguarding & rebuilding sand dunes. Sand dunes are great natural defense against unwanted coastal flooding & erosion, but are rendered useless when submerged by rising seas.
Thus, existing dunes need protection and support to effectively protect nearby residents and buildings from raging seas. Land management additionally involves the construction of boardwalks and the designation of existing dune areas as off limits to the public. These policies prevent unnecessary, man-made erosion to the dunes.
Another engineering method used by engineers for successful coastal management in the face of climate change is the creation and/or restoration of marshland. Marshlands naturally break up waves, slow their pace, and dramatically reduce their erosive ability.
Another "soft engineering" solution, beach stabilization involves the widening and deepening of sandy beach areas on the coastline. This approach is quite effective, but involves a significant spend to bring in the necessary tons and tons of sand. Additionally, because an eroding beach will continue to erode, additional sand must typically be brought in every 5-10 years.
Engineers are hard at work on effective coastal management solutions to combat the threat of rising seas. But the real solution lies in preventing the elevation of sea levels by lessening carbon emissions to reduce global warming.