Sand dunes change primarily by growing, shrinking, and moving due to the consistent action of wind and water.
Over time, coastal environments experience continuous reshaping driven by wind and water, resulting in dynamic dune formations. This leads to several key changes:
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Growth: Dunes increase in size as wind carries sand particles up their windward (upwind) side. These particles are deposited on the leeward (downwind) side, also known as the slipface, building the dune higher.
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Shrinking: Erosion by wind and water can reduce the size of sand dunes. Storms, high tides, and strong winds can remove significant amounts of sand, causing dunes to shrink.
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Movement: Prevailing winds cause dunes to migrate slowly over time. Sand is eroded from the windward side and deposited on the leeward side, resulting in the dune moving in the direction of the wind.
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Formation of Multiple Rows: As the coastline evolves, multiple rows of dunes can form, creating a complex system of ridges between the beach and more stable inland areas.
In essence, sand dunes are not static features; they are dynamic landforms constantly evolving in response to the forces of nature.
