Berm

A berm is a level space, shelf, or raised barrier (usually made of compacted soil) separating two areas. It can serve as a fortification line, a border/separation barrier, in industrial settings, or in many other applications. A berm is also used on mountain bike and BMX courses to assist the rider around a corner at speed; this type of berm is often steep and curved, unlike most 'construction berms'. The word berm originates in the Middle Dutch and came into usage in English via French.In medieval military engineering, a berm (or berme) was a level space between a parapet or defensive wall and an adjacent steep-walled ditch or moat. It was intended to reduce soil pressure on the walls of the excavated part to prevent its collapse. It also meant that debris dislodged from fortifications would not fall into (and fill) a ditch or moat.Berms are also used to control erosion and sedimentation by reducing the rate of surface runoff. The berms either reduce the velocity of the water, or direct water to areas that are not susceptible to erosion, thereby reducing the adverse effects of running water on exposed topsoil. Following the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, the construction of berms designed to prevent oil from reaching the fragile Louisiana wetlands (which would result in massive erosion) was proposed early on, and was officially approved by the federal government in mid-June, 2010, after numerous failures to stop and contain the oil leak with more advanced technologies.In coastal geography, a berm is a bank of sand or gravel ridge parallel to the shoreline and a few tens of centimetres high, created by wave action throwing material beyond the average level of the sea.Earth is piled up against exterior walls and packed, sloping down away from the house. The roof may or may not be fully earth covered, and windows/openings may occur on one or more sides of the shelter. Due to the building being above ground, fewer moisture problems are associated with earth berming in comparison to underground/fully recessed construction.For general applications, a berm is a physical, stationary barrier of some kind. For example, in modern highway construction, a berm is a noise barrier constructed of earth, often landscaped, running along a highway to protect adjacent land users from noise pollution. The shoulder of a road is also called a berm and in New Zealand the word sometimes describes a publicly owned grassed nature strip sometimes planted with trees alongside urban roads (usually called a verge). In snowboard cross, a berm is a wall of snow built up in a corner. In mountain biking, a berm is a banked turn formed by soil, commonly dug from the track, being deposited on the outer rim of the turn. In coastal systems, a berm is a raised ridge of pebbles or sand found at high tide or storm tide marks on a beach. In snow removal, a berm or windrow refers to the linear accumulation of snow cast aside by a plow. In open-pit mining, a berm refers to dirt and rock piled alongside a haulage road or along the edge of a dump point. Intended as a safety measure, they are commonly required by government organizations to be at least half as tall as the wheels of the largest mining machine on-site.  Media related to Berms at Wikimedia Commons