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Energy of River - Coggle Diagram

- - - - A measure of the resistivity offered by the material constituting stream
      - Presence of boulders on the river bed and protruding rocks on the river banks => rougher river channel => river flow encounters more resistance and friction between river flow and channel => friction needs to be overcome => slower river flow
    - - Shape of channel or its cross section affects wetted perimeter (extent to which water is in contact with its channel)
      - Greater wetted perimeter => greater friction between water and banks and bed of channel => slower flow of river
    - - depends on angle of inclination / rate of rise or fall
      - steep slope => sharp inclination => higher velocity than gentle gradient
      - gradient decreases downstream
  - - - Larger drainage basin => larger surface area => more rainwater flow off the surface as surface runoff or overland flow into the surrounding river channels => more tributaries contribute water to the main river => high volume of river flow
    - - Area covered with vegetation => higher rates of interception and infiltration => lower surface runoff => lower volume of water
      - Area with little or no vegetation => no interception and little infiltration => more surface runoff => higher volume of water
    - - Permeable: allow water to pass either via a network of pore spaces between particles, or along bedding planes, cracks, and fissures
        
        Depends on grain size of rock and size of pore spaces between grains
      - Water flows through area of permeable rock => more water infiltrates the ground => low surface runoff => lower volume flow
      - Water flows through area of impermeable rocks => little water infiltrates the ground => high surface runoff => higher volume flow
    - - Affected by amount of precipitation and temperature
      - Dry season => river channel may be almost empty => low water volume
      - Wet season => high water volume => water may overflow the channel => flood surrounding land
      - Amount of rainfall
        
        Affected by intensity and duration of rainfall
        
        High rainfall of long duration => high volume of flow
        
        Low rainfall for brief period => low volume of flow