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Dyke (fortification)
A levee ( or ), dike (American English), dyke (British English; see spelling differences), embankment, floodbank, or stop bank is an elevated ridge, natural or artificial, alongside the banks of a river, often intended to protect against flooding of the area adjoining the river. It is usually earthen and often runs parallel to the course of a river in its floodplain or along low-lying coastlines. Naturally occurring levees form on river floodplains following flooding. Sediment and alluvium are deposited on the banks and settle, forming a ridge that increases the river channel's capacity. Alternatively, levees can be artificially constructed from fill, designed to regulate water levels. In some circumstances, artificial levees can be environmentally damaging. Ancient civilizations in the Indus Valley, ancient Egypt, Mesopotamia and China all built levees. Today, levees can be found around the world, and failures of levees due to erosion or other causes can be major disaste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Levee Cross Section Figure
A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. Rivers are regulated by the water cycle, the processes by which water moves around the Earth. Water first enters rivers through precipitation, whether from rainfall, the runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the Earth. Rivers flow in channeled watercourses and merge in confluences to form drainage basins, or catchments, areas where surface water eventually flows to a common outlet. Rivers have a great effect on the landscape around them. They may regularly overflow their banks and flood the surrounding area, spreading nutrients to the surrounding area. Sediment or alluvium carried by rivers shapes the landscape ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
