rivers

• Abrasion


  Rocks carried along by the river wear down the river bed and banks (sandpaper motion).
• Afforestation


  The planting of trees (a method to reduce flooding by increased interception).

  
• Alluvium


  A deposit of clay, silt, and sand left by flowing floodwater in a river valley or delta, typically producing fertile soil.

  
• Attrition


  Rocks being carried by the river smash together and break into smaller, smoother and rounder particles.
• Catchment


  The area from which water drains into a particular drainage basin.
• Confluence


  The point at which two rivers join.

  
• Delta


  A triangular tract of sediment deposited at the mouth of a river, typically where it diverges into several outlets.

  
• Deposition


  The dropping of sediment that was being carried by a moving force

  
• Discharge


  The volume of water flowing through a river at a certain point.
• Drainage basin


  Is an area of land drained by a main river and its tributaries.

  
• Erosion


  The wearing away and removal of material by moving a force such as the flow of a river

  
• Floodplain


  The relatively flat area forming the valley floor on either side of a river channel, which is sometimes flooded
• Flood risk


  The predicted frequency of floods in an area
• Gorge


  The processes of undercutting and collapse are repeated over a long period of time forming a deep, steep-sided valley.

  
• Groundwater flow


  Water that flows underground.

  
• Hard engineering


  Using solid structures to resist forces of erosion

  
• Hydraulic Action


  The force of the river against the banks can cause air to be trapped in cracks and crevices. The pressure weakens the banks and gradually wears it away.

  
• Storm Hydrograph


  A graph which shows the discharge of a river, related to rainfall, over a period of time

  
• Integrated river management


  A holistic system of managing rivers that takes an overview of the whole river basin and the relationship between its different parts
• Impermeable


  Not allowing water to pass through.

  
• Interception


  When precipitation is interrupted in its fall to the ground e.g. by trees.
• Infiltration


  When water passes through a permeable surface e.g. soil.
• Interlocking spurs


  Areas of high land which stick out into steep sided valleys

  
• Lag time


  The time that it takes between peak precipitation and peak discharge.

  
• Levee


  Natural embankments of sediment along the banks of a river

  
• Long profile


  The gradient of a river, from it source to its mouth

  
• Lower course


  That part of a river system that is close to the mouth of the river - oxbow lakes, meanders, floodplain and deltas.

  
• Meander


  The bend formed in a river as it winds across the landscape

  
• Middle (mid) course


  The central section of a rivers course - meanders

  
• Mouth


  Where the river flows into the sea, or sometimes a lake.

  
• Ox-bow lake


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

  
• Permeable


  Allows water to pass through it.
• River cliff


  Steep outer edge of a meander where erosion is at its maximum
• Saltation


  Small pebbles and stones are bounced along the river bed.

  
• Sediment


  Usually sand, mud or pebbles deposited by a river

  
• Slip-off slope


  Inner gentle slope of a meander where deposition takes place

  
• Solution (corrosion)


  minerals are dissolved in the water and carried along in solution

  
• Source


  The upland area where the river begins.

  
• Surface run-off


  Water from rain, snowmelt or other sources than runs over the land.

  
• Suspension


  fine light material is carried along in the water