A beach is a stretch of land on which people can walk, run, or swim. Sand beaches are popular worldwide and play an important role in culture and recreation. They also drive local tourism industries. Some beaches feature man-made infrastructure, such as lifeguard posts and changing rooms. Others may feature housing and hotels. In the United States, about a quarter of the coastline is occupied by a beach.
The sand on a beach is made up of all kinds of different materials. Beach sand, pebbles, rocks, and seashell fragments are just a few of the elements that make up a beach. These natural substances are formed over many years through the weathering process. When waves strike land, the erosion creates loose rocks, causing the rock to shift and become part of the sand.
The processes underlying the development of cusps on a beach are complex and variable. One theory posits that tidal cycles play a role in their development. A beach with a higher tidal level will have more cusps. Another explanation involves post-storm conditions.
Beaches also act as filter beds, trapping sediment that would otherwise wash into the sea. These sediments act as food for coastal flora and fauna. Clearing vegetation, however, increases the erosive power of runoff. In addition to silt, the runoff also carries more organic matter, which can contribute to erosion.
Beach composition depends on the composition of sediments upstream. Waves and wind move these sediments and are affected by particle size and state of compaction. The more compacted the sediments, the more resistant they are to erosion. In addition, the presence of vegetation will slow the fluid flow on the surface layer. When waves are long and the tide is high, sediment will not settle and will be more prone to erosion from longshore currents.
Sand on the beach is formed by the combination of water and minerals. The erosion process begins in mountains and continues down rivers and streams. The resulting sediments are carried to the ocean by water and wind. The waves then break these sediments into sand. The sediments eventually form bays. The formation process can take thousands of years.
Sands and sediments have varying profiles and characteristics, and the type of flora that grows on them is highly dependent on freshwater runoff. Diverting freshwater runoff into a drainage system can deprive these plants of the water they need to survive. It may also result in a higher salinity of groundwater. In addition, some species of plants cannot survive in salt water and may disappear, being replaced by mangroves.
In the early nineteenth century, the beach was developed into a popular leisure resort for the aristocracy. By the 1720s, seaside towns such as Scarborough were opened for fashionable people to enjoy. Queen Victoria favored seaside towns and started a trend of seaside dwelling.