Rivers

• Levees


  Embankments of sediment along the bank of a river, formed naturally by regular flooding and can be built up by people to protect against flooding
• Flood plain


  The relatively flat area forming the valley floor on either side of the river channel.
• Gorge


  A narrow, steep sided valley often formed when a waterfall retreats upstream
• Erosion


  The removal of weathered sediment by the force of the river water
• Attrition


  the material being carried by the river knocks against one another causing it to become smaller and rounder
• Hydraulic Action


  The sheer force of the water hitting the bed and banks
• Abrasion


  The load repeatedly hits the bed and banks, a sandpapering effect that deepens and widens channel over time.
• Solution


  When river water flows over soluble rocks they become part of the water as they are dissolved by it.
• Traction


  the largest material is rolled along the bed of the river at times of high discharge
• Saltation


  A leapfrogging movement as small stones and grains of sand bounce along the river bed
• Suspension


  The finest material, clay, is carried within the water.
• Lateral Erosion


  The direction of erosion by the river that is sideways. It becomes more dominant in middle and lower course.
• Vertical Erosion


  The direction of erosion by the river that is downwards. It is dominant in the upper course of a river valley.
• Deposition


  When material is dumped by the river at times of low discharge or when the carrying capacity of the water is exceeded.
• Erosion


  The wearing away of the landscape by the movement of the river
• Transportation


  The movement of sediment by the river.
• Hydrograph


  shows the discharge of a river, related to a rainfall event, over a period of time.
• Flood plain zoning


  An attempt to organise land use so that the land nearest the river that floods most often is not built on
• Flood relief channels


  New artificial channels that are used when a river is close to maximum discharge to take the pressure of the main channel and so reduce the flood risk.
• Embankments


  Raised banks constructed along the channel so that they make the river deeper so it can hold more water.
• Hard Engineering


  Building artificial structures using materials such as rock, concrete and steel, to reduce, disrupt or stop the impact of river processes.
• Soft Engineering


  The use of the natural environment surrounding a river, using schemes that work in harmony with the rivers natural processes.
• Interlocking Spurs


  A series of ridges of land projecting out on alternate sides of the valley around which the river winds.
• Meander


  A pronounced bend in a river
• Ox-bow lake


  An arc-shaped lake which has been cut off from a meandering river
• Waterfall .


  A sudden descent of a river over a very steep slope in its bed. Usually where a river meets a band of relatively softer rock
• Estuary


  The tidal mouth of a river where it meets the sea, wide banks of deposited mud are exposed at low tide.
• Fluvial Processes


  Processes relating to erosion, transport and deposition by a river.
• Lagtime


  The time taken from peak rainfall to when peak discharge occurs, in hours.
• Baseflow


  the normal day to day discharge of the river and is the consequence of groundwater seeping into the river channel.
• Interception


  The temporary storage of water on vegetation
• Infiltration


  The movement of water from the surface into the soil
• Discharge


  the volume of water passing a given point at a given time in cubic metres per second.