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| Question | Answer |
| Confluence- point where tributaries meet the main channel As more tributaries join the river gets wider, deeper and has a lower gradient. | Drainage basin- the area of land that a river drains Watershed- the border line of the drainage basin |
| When in the upper course the river erodes downwards (V-shaped valley formed), in the middle course the slope decreases and the energy is used to carry the material eroded & erodes laterally, then in the lower course the river deposits load due to decreased gradient. | Discharge- amount of water passing a specific point at a given time in m3 volume x velocity = discharge |
| The velocity of the river is determined by the amount of water touching the river's bed and banks, if the river is deeper there is less contact so there is less friction and a greater velocity. | Upper course has V-shaped valley, interlocking spurs and waterfalls. In the upper course a lot of the river is in contact with it's bed and banks so there is a lot of friction, energy is spent overcoming this firction and erodicing vertically. |
| Water takes the easiest course wo when eroding vertically in the upper course it follows softer rock, between barriers of more resistant rock- as this continues interlocking spurs are formed. | A waterfall forms when a river reaches an outcrop of less resistant rock, the softer rock is cut back more quickly leaving an overhang of more resistant rock. In time gravity pulls the overhang off and the debris sits in the plunge pool which is deepened by corrosion on the bed. |
| Hydraulic action and splash back undercut the soft rock further which causes the process to repeat, gradually the waterfall moves further upstream leaving a steep sided gorge. | In the middle course the river is deeper as a result of being joined by a number of tributaries/greater volume, less water is in contact with the channel so there is less friction and it has more power to erode. |
| The outside of a meander bend has the deepest water so this is where the most erosion takes place and forms a river cliff. Water moves more quickly on the outside due to the lack of friction, deposition occurs on the inside where water is slower/shallower making a slip off slope. | In the lower course of the river the channel is wide and deep and is surrounded by a wide valley floor |
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