Coastal Change Hazards: Hurricanes and Extreme Storms

Storm-Induced Coastal Change

Overview

Hurricanes and other extreme storms generate storm surge and large waves, eroding the beach and dune system and reshaping the coastal landscape. During the most extreme events, changes can occur across the width of an entire barrier island. Six types of coastal change observed along the coastlines of the United States are:

Beach Erosion Beach erosion occurs when waves and currents remove sand from the beach system. The narrowing of the beach threatens coastal properties and tourism revenue in coastal counties throughout the United States.

Dune Erosion Dune erosion occurs when waves attack the front face of the sand dune, reducing the volume and elevation of the dune. Erosion of the sand dune leaves coastal properties more vulnerable to future storms.

Overwash When waves exceed the elevation of the dune, sand is transported across island in a process known as overwash. When overwash occurs, it often results in significant damage to coastal property.

Inundation and Island Breaching Inundation occurs when an island is completely submerged under the rising storm surge. Strong currents may carve a channel in the island in a process known as island breaching.

Marsh Erosion Marsh erosion occurs on wetland coastlines exposed to the open ocean or wide bays. Waves and currents erode the wetland soil, causing significant losses of land area.

Coastal Cliff Erosion The impact of waves and currents on coastal cliffs may cause the base of coastal cliffs to erode, eventually undermining the cliff and causing slumping. Materials eroded from the base of the cliff provide sediment for adjacent beaches.

continue to Beach Erosion