Coastal protection
Coastal protection reduces erosion and flooding using natural features, engineered structures, or managed changes to shorelines.
Seawall: A shore-parallel structure designed to resist waves and prevent land behind it from eroding or flooding. Seawalls block wave attack directly, but can intensify erosion at their base and ends.
Coastal flood: Flooding of land along a coast from high water, waves, storm surge, or sea-level rise. Flood risk is a central reason to build or restore coastal barriers.
Coastal erosion: The removal of coastal land or sediment by waves, currents, tides, or other processes. Protection aims to slow erosion, but structures may shift it to adjacent shores.
Hard engineering: The use of built structures to control natural processes or protect land and infrastructure. Seawalls and groins are hard-engineering options within the broader protection toolkit.
Breakwater: An offshore or nearshore structure that reduces wave energy reaching a protected coast or harbor. Breakwaters weaken incoming waves before they reach the shoreline.
Storm surge: An abnormal rise in sea level during a storm, driven mainly by wind and atmospheric pressure. Storm surge can overwhelm defenses designed for ordinary tides and waves.
Longshore drift: The transport of sediment along a coast by waves approaching at an angle. Interrupting this movement can cause sediment accumulation on one side and erosion on the other.
Nature-based solutions: Actions that protect, manage, or restore ecosystems while addressing societal challenges. This broader approach includes ecosystem-based defenses as alternatives or complements to rigid barriers.
Groin: A shore-perpendicular structure that interrupts sediment transport along a beach. Groins build beaches on their updrift side while often depriving down-drift shores of sand.
Tsunami: A series of long waves generated by sudden displacement of a large volume of water. Tsunamis can exceed the design limits of ordinary coastal defenses.