V-shaped valley
Topic: Landforms and their Evolution: Rivers, Groundwater, Glaciers, Waves and Wind · NCERT: Class 9, Ch 2 "Shaping of the Earth's Surface"; Class 11, Ch 6 "Landforms and their Evolution"; Class 11, Ch 5 "Topographical Maps"
Meaning
A V-shaped valley is a river valley with steep sides that slope down to a narrow floor, like the letter V. It forms when a young river on a steep slope cuts straight down into its bed. This deepening of the bed is called vertical erosion, or downcutting. At the same time, weathering (rock breaking up where it stands) and mass movement (soil and rock sliding downhill) wear back the valley sides. It is the typical valley of the youth stage of a river.
Example
The upper Bhagirathi in Uttarakhand flows through deep V-shaped valleys as it comes down from the Gangotri glacier.
Don't confuse with
- U-shaped valley: a glacier carves this valley. It has a broad, flat floor and steep, smooth sides.
- Gorge: a gorge is a very deep valley in hard rock with almost vertical sides. It is about as wide at the top as at the bottom, so it is not a V.