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RIVERS (MEANDERS AND OXBOW LAKES (They are towards the sea, always found…
RIVERS
MEANDERS AND OXBOW LAKES
They are towards the sea, always found in flatland
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Water flows faster on the outer curve of the bend, and slower on the inner curve
The outer bank gets eroded, but material is deposited at the inner bank
As the outer bank wears away, and the inner one grows, a meander forms
As the process continues, the meander grows more 'loopy'
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In time the lake will get covered with weeds, and fill with soil, and disappear
FEATURES OF RIVER
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Deltas: Where deposition has taken place. Little 'islands' of land (not always fixed) are found. However heavy rainfall can erode them
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RIVER COURSES
UPPER COURSE
Features: source, waterfalls
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MIDDLE COURSE
Features: Tributaries, confluences, meanders
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LOWER COURSE
Features: oxbow lakes, flood plains, mouth, deltas
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As you move from the upper course, the river is steep and shallow. The river is usually straight with no bends or meanders. However during the middle course, more tributaries and more water into the original river and becomes wider and deeper. Here it is also bendier and have more suspended sediment. During the lower course, where the river is most deep and wide, floodplains and oxbow lakes are found. It becomes wider because it starts to meet with the sea/lake
WATERFALLS
HARD ROCK: This rock is resistant so over time a ledge develops as it is UNDERCUT when the rock beneath it disappears.
WATERFALL: Where the water tumbles over the ledge
SOFT ROCK: This is easier to erode
GORGE: The waterfall retreats backwards up the valley, leaving a narrow, steep sided canyon
FALLEN ROCKS: When the ledge collapses it falls into the plunge pool providing materials to be eroded.
PLUNGE POOL: The deep pool directly underneath the waterfall that is eroded most rapidly (by hydraulic action).