River landforms

waterfall
description - A steep drop in the bed of a river causing the water in the river to fall vertically.
explanation - Waterfalls occur where a band of harder rock crosses the path of a river. The river is less able to erode this harder rock and leaves it as a step in the river's long profile.

Here is an animation link for waterfall formation: http://whs.moodledo.co.uk/file.php/1365/Fluvial%20systems/Waterfall2.swf

ox - bow lake
description - This is a truncated (cut off) section of a meander in the river channel which forms a 'c' shape.
explanation - This is formed by the loops in a meander eroding the flood plain until eventually the loop in the meander is left cut off from the main river channel.
diagram - Diagram 2.6h shows four stages in the formation of an ox - bow lake.

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meanders
description - These are bends (loops) in the river. explanation - Lateral (sideways) erosion of the river channel results in the river forming a winding pattern. (tip ! if a river or stream has an absolutely straight pattern then it is probably artificial i.e. a canal).
diagram - As the water flows down a river, its speed is faster on the outside of the meander causing erosion and slower on the inside of the meander resulting in deposition.
This is shown in the diagram below. Mark two areas of erosion and two areas of deposition on Diagram 2.6i.

here is an animation for meander and ox bow lake: http://www.cleo.net.uk/resources/displayframe.php?src=309/consultants_resources%2F_files%2Fmeander4.swf

flood plain
description - This is an area of flat land found on either side of a river. This usually becomes wider as the river nears its mouth.
explanation - The flood plain is the area of land which is flooded when a river overflows its banks. In this area layers of alluvium are laid down. The soils are thus thick and fertile and the land is flat.

Here is an animation for floodplains:
http://whs.moodledo.co.uk/file.php/1365/Fluvial%20systems/Features%20of%20a%20River%20Floodplain.swf

here is an animation link for levees:
http://www.geography.ndo.co.uk/animations2.htm

levees
description - These are mounds of alluvium piled up along the river's edge.
explanation - These are formed by the river depositing the coursest part of its load (pebbles, gravel and sand) close to the river channel when the river floods. This happens because usually when the water overflows the river bank its speed (and therefore its ability to transport alluvium) is greatly reduced.
Sometimes these are built by people in an attempt to prevent the river flooding.
Why should people go to so much trouble and expense to prevent a river flooding ?
diagram - Examine and suitably shade in the following diagram.
Colour in yellow the levees on Diagram 2.6e

v-shaped valley
description - This is a valley whose typical cross section is shaped like a 'v'.
explanation - As the river cuts down into the landscape in an upland area, gravity and mass movements roll material down the valley sides to give the valley a typical 'v' shape.

REMEMBER: All landforms are created by erosion and deposition, it is only a question which process comes more into play, for example:
Valley, waterfall, Gorge = More erosion
Meander=both erosion and deposition
Floodplains, levees, ox bow lake, deltas=more deposition