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A road, railway line, or canal is normally raised onto an embankment made of compacted soil (typically clay or rock-based) to avoid a change in level required by the terrain, the alternatives being either to have an unacceptable change in level or detour to follow a contour.
The low-lying areas (dark blue) defended by the river walls, where 1.25 million people live or work. (After Lavery & Donovan, 2005.) (After Lavery & Donovan, 2005.) The tidal Thames today is virtually a canal [ 14 ] [ 2 ] —in central London, about 250 metres wide—flowing between solid artificial walls, and laterally restrained by these at ...
The side of a levee in Sacramento, California. A levee (/ ˈ l ɛ v i / or / ˈ l ɛ v eɪ /), [a] [1] 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.
A graph shows the groundwater level and sea level changes with respect to the tide on a small island in Portugal. The solid line represents the sea level change in the estuary and the dotted line is date from a piezometer that installed 50 m apart from the coastal line. It shows a time lag between the sea tide and the tide of groundwater.
A levee, an artificial bank raised above the immediately surrounding land to redirect or prevent flooding by a river, lake or sea; Embankment (earthworks), a raised bank to carry a road, railway, or canal across a low-lying or wet area; Embankment dam, a dam made of mounded earth and rock
By placing these embankments somewhat back from the margin of the river-bed, a wide flood-channel is provided for the discharge of the river as soon as it overflows its banks, while leaving the natural channel unaltered for the ordinary flow. Low embankments may be sufficient where only exceptional summer floods have to be excluded from meadows.
When compared to conventional flood protection infrastructure such as embankments and seawalls, sedimentation enhancing strategies provide various benefits.Firstly, flood protection structures can exacerbate environmental problems in deltas: land reclamation and levee construction result in a loss of water storage area during peak river discharges, which may cause an increased risk of flooding ...
The choice of strategy is site-specific, depending on pattern of sea-level change, geomorphological setting, sediment availability and erosion, as well as social, economic and political factors. Alternatively, integrated coastal zone management approaches may be used to prevent development in erosion- or flood-prone areas, reducing the need to ...