Sea walls are robust structures, typically made of concrete, masonry, or gabions, designed primarily to protect coastal areas from erosion and flooding caused by high tides and storm surges. They achieve this by absorbing and redirecting the energy of incoming waves.
How Sea Walls Protect Coastlines
- Wave Energy Reduction: The primary function of a sea wall is to minimize the erosive impact of waves. The wall's solid structure forces waves to break and dissipate their energy before reaching the land. This is achieved through a variety of designs, including sloped, stepped, or vertical structures, each influencing how waves interact with the wall. [Source: https://blog.duncanseawall.com/what-is-a-seawall-and-how-does-it-work]
- Erosion Prevention: By absorbing wave energy and preventing direct wave impact on the shoreline, sea walls significantly reduce coastal erosion. This protects buildings, infrastructure, and the natural environment immediately behind the wall. [Source: https://www.ctc-n.org/technologies/sea-walls]
- Flood Defense: Sea walls act as barriers against flooding, preventing high tides and storm surges from inundating coastal areas. They are designed to withstand significant wave forces for a considerable lifespan (typically 30-50 years). [Source: Provided text]
- Redirecting Wave Energy: The design of the sea wall influences how waves are redirected. Sloped seawalls, for instance, allow some wave energy to be reflected back out to sea, while vertical walls tend to cause waves to break and dissipate their energy directly against the wall. [Source: https://thegeographyteacher.com/sea-walls/]
Types and Considerations
Sea walls come in various designs, each tailored to specific coastal conditions and wave patterns. Regular inspections and maintenance are crucial for their long-term effectiveness. [Source: https://climate-adapt.eea.europa.eu/en/metadata/adaptation-options/seawalls-and-jetties] However, it's important to note that while effective in protecting immediate areas, seawalls can have unintended consequences, such as increased erosion in adjacent areas. [Source: https://engineering.mit.edu/engage/ask-an-engineer/can-seawalls-prevent-beaches-from-eroding/]
