A beach is a landform along the shoreline of an ocean, sea, lake, or river. It usually consists of loose particles, which are often composed of rock, such as sand, gravel, shingle, pebbles, or cobblestones. The particles comprising the beach are occasionally biological in origin, such as mollusc shells or coralline algae.
Wild beaches are beaches that do not have lifeguards or trappings of modernity nearby, such as resorts, camps, and hotels. They are sometimes called undeclared, undeveloped, or undiscovered beaches. Wild beaches can be valued for their untouched beauty and preserved nature.
Beaches are changed in shape chiefly by the movement of water and wind. Any weather event that is associated with turbid or fast flowing water, or high winds will erode exposed beaches. Longshore currents will tend to replenish beach sediments and repair storm damage. Tidal waterways generally change the shape of their adjacent beaches by small degrees with every tidal cycle. Over time these changes can become substantial leading to significant changes in the size and location of the beach.
Effects on flora
Changes in the shape of the beach may undermine the roots of large trees and other flora. Many beach adapted species (such as coconut palms) have a fine root system and large root ball which tends to withstand wave and wind action and tends to stabilize beaches better than other trees with a lesser root ball.
Effects on adjacent land
Erosion of beaches can expose less resilient soils and rocks to wind and wave action leading to undermining of coastal headlands eventually resulting in catastrophic collapse of large quantities of overburden into the shallows. This material may be distributed along the beach front leading to a change in the habitat as sea grasses and corals in the shallows may be buried or deprived of light and nutrients.
Manmade erosion and accretion
Coastal areas settled by man inevitably become subject to the effects of man-made structures and processes. Over long periods of time these influences may substantially alter the shape of the coastline, and the character of the beach.