Rivers

• River features


  • 21
  • 12
  • cross profile
  • 2.3
  • hydraulic power
  • LA
  • solution
  • LS abrasion
  • 16
  • LT
  • Enpension
  • 18
  • utation
  • 19
  • Fraction
  • 110
  • 808
  • 111 tramperetion
  • Aline soprase sting a river from its source to its nowhit dhows how a river changes
• Cross section


  A cross section at a riven channel and walley at a certain petaleng a rivers con
• Hydraulic power


  The sheer power of the water in the River smashing against the river bank
• Solution


  Where the river water duches raerial is the river bank
• LS abrasion


  Fecks certed in the rer scoping at the bed and banks
• Enpension


  Rocks carted in the river basing Ingher and breaking dow
• utation


  Sediment and fine particles carried in the rivers flow
• Fraction


  Small rocks bounced along the river bed
• Tramperetion


  Large rada and boulders reled along the river bed
• Aline soprase sting a river from its source to its nowhit dhows how a river changes

  The breakdown of materal ever line
• Madlang in the rivers flew

  313 pation
• Hovely an ana to flood

  135 d
• Agraph showing the rate of river flow seras peak rainfall


  They can be used to show
• lateral rasion


  Iresion that occurs side to side juually in the middle to lower counsel
• vertical ecces


  Erosion that occum domands (sally in the upper coun
• Upper course land


  • The streams are often very small and have low discharge
  • Up to 95% of their energy is used to overcome Fetise and the rest to erode vertically via abrasion and hydraulic action
  • This leaves the sides of the river channels steep and upported
  • The sides are also weakened by weathering and mass movement, and bits slide down into the channel to be washed away by the river leaving a V-shaped valley
• Interior


  • The land has rocks of various resistances. The river winds its way around the more resistant rack and cuts down into the weaker rock. This creates interlocking spurs
• Water


  • They occur where a band of hand rock leg granite) cere saber rack (eg sanchtonel
• Erosion processes


  • Erosion processes such as hydraulic action the force of the water) and abrasion (where the river rabs stores that are being bumperted against the bed of a ther thereby breaking it down) dominate. The softer rock is eroded quicker than the harder rack and gradually washes away downstream
• Plunge pool


  • This creates a plunge pool where water is swilled around potholing can occur here and any rocks and debris svept into the plunge pool by the river will be swirled around and rub apainot the bed and banks of the plunge pool called ABRASION deepening it further
• Waterfall


  • Over time, the saber rock is eroded further creating an overhang of sand rock. This overhang is urntable as to weight is unsupported. Eventually, this hard rack collapses because it i ussupported and the waterfall moves back spstream
• Gorges


  • This creates gangen, which are steep sided deep river saleys. This process will repeat continually, with the location of the waterfall moving back upstream
• Middle course and meanders and exbaxlen

  • Fast at floding
• Factors affecting flooding


  • Precipitation amount-the longer header rains the mase kely to flood
  • Belief steep slopes reduce the rate of WRIation
  • Vegetation type and coverage-the more wegstation the greater the rate of Interception
  • Geology impermeable rocks such as a clay and shale do not allow water to inftrate
  • Perrasable socks allow water to intrane therefore reduce time to infibrate
• Methods of managing flooding

  • Daire-building a wall across a river can central the river flow, storing water above the dam in a reserver to prevent flooding downstream
  • Flood relat channel creating a se river channel next to arban areas to dirt water away from them. Provides additional channel to catch extra w
  • Chassel straightening coffing off meander to create a straight channel to way from flood risk areas
  • Embankments belding web alongside the river banks to prevent flooding whes the river levels got too high
  • Carrying capacity sched
• Human factors affecting flooding

  • urbanisation create impermeable surfaces therefore they increase runoff
  • Deforestation increase soil erosion redate interception and increase flood rbik
  • Increase in population results in more urbanisation and people living en floodplains Therefore increases the risk of flooding
• Soft engineering methods


  • Warning Systems Providing people with warning of floods so that they can evacuate
  • Floodplain aning Preventing expen buildings from being built alongside the er, bet allowing cheaper land unele playing Selds or car parks instead
  • River restoration-Returning the rivers its natural state, where it is allowed to food in certain area, or creating wetlands to catch/low down flood water rataraly
• Middle course landforms


  • lateral erosion in this section of the valley the river crades laterally and migrates across the salley floor aver Ere, widening the valley
  • Within the river self, the fastest cument is found on the outside of a bend and the slowest carent on the side of the bend. This is because the depth of the water on the outside of the bend is deeper, there is less friction and hence higher velocities
  • Over time, this means uteresen course the outside of meander bends and deption occurs on the inside
  • Erosion of the outside of the reader means that the neck of land becomes snower oversee the mide of the bend the slow we encourages the date of beaches
  • After a long time the neck af land gets totally out through by erosion process such as hedication and abradice his outs off the reader bend which is total salted by depetion lengan De bew lake, which is a crescent shaped lake that will evenly with redh and sediment
• Lower course landforms


  • Rivers flood on a regular basis. The fat area over which they flood is known as the floodplain and this often coincides with regions where and form
  • When they flood velocity is slowed and deposition of any being tramperted is encou
  • The deposition leaves alper of sediment as the whole Foodplain aer al Pere are seven levers of sediment rock dea ce t fleadpa
  • In addition, the largest rocks and most depots the ver thome. The leaves a ridge of Sigher nutsal ta the river shemel en beh kano of the river known as a leve
  • Meandering vers can code gwylo len development by eroding laterally and helping to fames saley flows
  • Rivers spread out and slows down at approaches the sea, Deposition is therefore encausa theo a wider bed the diver bees no effort a biggest dirt is hoped fest and the f sedimentation
  • Layers of sediment build up. The river whare peda low to the causes bars or sinch of sediment to build is the of the main channel