Rivers

• Store


  A place where water is held within the hydrological cycle
• Stores


  • lakes
  • oceans
  • glaciers
  • groundwater aquifers
• Flow/Transfer


  The movement of water between different stores in the hydrological cycle
• Flows/Transfers


  • precipitation
  • evaporation
  • infiltration
  • surface runoff
  • transpiration
• Open System


  Exchanges both energy and matter with its surroundings (e.g., a river basin)
• Closed System


  Exchanges energy but not matter with its surroundings (e.g., the global water cycle)
• River discharge


  The volume of water flowing through a river channel at a given location and time, usually measured in cubic meters per second (m³/s)
• Factors that influence a river regime

  • Climate
  • Geology
  • Vegetation
  • Human Activities
  • Topography
• Lag time


  The period between peak rainfall and peak river discharge
• Factors contributing to a flashy (short lag time) river hydrograph

  • Steep Slopes
  • Impermeable Rock
  • Urbanization
  • Intense Rainfall
• Factors contributing to a flat (long lag time) river hydrograph

  • Gentle Slopes
  • Permeable Rock
  • Vegetation
  • Light Rainfall
• Lateral erosion


  The sideways erosion that widens a river channel or valley, typically occurring in the middle and lower courses of a river
• Vertical erosion


  The downward erosion that deepens a river channel, usually dominant in the upper course of a river
• Types of weathering


  • Mechanical (Physical) Weathering
  • Chemical Weathering
  • Biological Weathering
• Types of erosion


  • Hydraulic Action
  • Abrasion
  • Attrition
  • Solution
• Sections of the river profile

  • Upper Course
  • Middle Course
  • Lower Course
• Types of river transportation

  • Traction
  • Saltation
  • Suspension
  • Solution
• Rivers erode more material during periods of high discharge, such as during heavy rainfall or snowmelt, which increases the river's energy and its ability to carry and erode materials
• Rivers deposit sediment when they lose energy, such as when the gradient decreases, flow slows down, or when entering a body of water like a lake or ocean
• Landforms in the upper course of a river

  • V-shaped valleys
  • Interlocking spurs
  • Waterfalls
  • Rapids
• How a waterfall is formed

  A river flows over a vertical drop or cliff, typically where hard rock overlays softer rock. The softer rock erodes faster, creating a plunge pool and leading to the collapse of the hard rock.
• How a meander is formed

  Faster flow on the outer bend causes erosion (forming a river cliff), while slower flow on the inner bend causes deposition (forming a slip-off slope)
• How an oxbow lake is formed


  A meander becomes extremely curved, and eventually the neck of the meander is cut through by the river, leaving an isolated U-shaped body of water
• Meander


  A bend or curve in a river, typically found in the middle and lower courses, characterized by an asymmetrical cross-section with deeper water and erosion on the outer bend and shallower water and deposition on the inner bend
• How levees are formed

  A river floods and deposits coarse sediment on its banks. Repeated flooding builds up these deposits, creating raised banks.
• How floodplains are formed

  Flat areas of land adjacent to a river, formed by the deposition of alluvium during periodic flooding. Over time, layers of sediment build up, creating a fertile area prone to flooding.