Back to Main Page | Back to GCSE Page | Back to Rivers, Coasts and Glaciers |
Landforms of the upper valley - V-shaped valleys and waterfalls
Landforms in upland regions are dominantly created by erosion processes, where land is worn away. Generally, the volume and discharge of rivers in upland regions tends to be low, and the river uses much of it's energy in overcoming friction. The erosion direction here is vertical, or straight down into the bed of the river. This has the effect of destabilising the slopes on either side of the river, creating a steep landscape. As shown below, near to the Kunar River in Pakistan.
Landforms in the Upper Valley
Waterfalls
Niagara falls, one of the worlds most famous waterfalls, but not in the upper reaches of it's river! | Above is a diagram showing the formation of a waterfall. You can see an animation by clicking here. |
Waterfalls are one of the most spectacular landforms found in the upper
valley and are created by erosion processes.
Erosion processes such as Hydraulic Action (the force of the water) and Abrasion
(where the river rubs stones that are being transported against the bed of a
river thereby breaking it down) dominate.
The softer rock is eroded quicker than the harder rock and gradually washes away
downstream.
This creates a plunge pool where water is swilled around, potholing can occur here and any rocks and debris swept into the plunge pool by the river will be swirled around and rub against the bed and banks of the plunge pool (called corrasion), deepening it further.
Over time, the softer rock is eroded further creating an over hang of hard rock.
Eventually, this hard rock collapses because it is unsupported and the waterfall
moves back upstream.
This creates Gorges, which are steep sided deep river valleys.
V shaped valleys and interlocking spurs
Vertical erosion processes wear away the rock in upper valleys.
As the river erodes
vertically down over it leaves behind valley sides that are shaped like a
letter V
In addition,
the river valley may also contain interlocking spurs, slivers of land that
interlock. Interlocking spurs are
areas of more resistant rock left behind because the river erodes softer rock
quicker. The river moves between
the interlocking spurs.
Tasks
1) Find out about
upper landform features from the BBC and take a test
2) Using the maps below describe the shape of each land form and explain why
they take that shape on the map
V-shaped valley map | Waterfall map |
3) Play a rivers Penalty shoot out game from Juicy Geography!