RIVERS

• abrasion

  rocks and boulders rub and wear away the river bed
• afforestation

  planting of trees
• attrition

  pebbles collide and become smaller and smoother
• channel straightening

  removing of meanders from a river to make a river straighter - allows it to carry more water quickly downstream so it doesn't build up and makes it less likely to flood
• confluence

  where two rivers meet
• cross profile

  a sideways view of a river channel
• dam and reservoir

  a barrier which holds back water, where it is stored as a reservoir
• deposition

  the material carried by the river
• discharge

  the quantity of water that passes a given point on a stream or river bank within a given period
• embankments

  a raised man-made river bank
• estuary

  an area of tidal water just before the river mouth
• flood plain

  flat area either side of a river which floods when a river overflows
• flood plain zoning

  land that is near the river and often floods that doesn't get built on - could be used for pastoral farming or playing fields
• fluvial processes

  processes relating to erosion, transport and deposition by a river
• gorge

  a narrow, steep sided valley often formed as a waterfall and retreats upsteam
• groundwater

  water stored underground
• hard engineering

  man-made structures that try to control natural processes
• hydraulic action

  the force of the river against the banks causing air to be trapped in cracks and crevices - the pressure weakens the banks and gradually wears it away
• hydrograph

  a graph which shows the discharge if a river, related to rainfall over a period of time
• impermeable

  water cannot infiltrate
• infiltration

  water soaking into the soil
• interception

  trees catch water on their branches and trees
• interlocking spurs

  a series of ridges projecting out on alternate sides of a valley and around which a river winds its course
• lag time

  the time between peak rainfall and peak discharge in the river
• lateral erosion

  sideways erosion by a river on the outside of a meander channel - eventually leads to the widening of the valley and contributes to the formation of the flood plain
• levees

  naturally forming, raised bank next to a river formed where heavier materal is deposited when the river floods
• lowland areas

  areas that are near or at sea level, there are no large hills or mountains
• long profile

  the gradient of a river from its source to its mouth
• meander

  a bend in the river
• mouth

  where a river flows into the sea
• oxbow lake

  a lake which has separated from a meander
• permable

  allows water to soak through
• percipitation

  any moisture falling from the sky
• relief

  the shape and height of the land
• saltation

  small rocks and pebbles bounce along the river bed
• saturation

  the ground is full of water
• soft engineering

  methods that work with natural processes - usually cheaper and more sustainable
• solution

  material is dissolved in the water
• source

  the point where the river starts - often high ground
• sustainable

  meet the needs of people now and future generations - has to be good socially, economically and environmentally