A valley is a landform that is situated between two hills or mountains and is longer than it is wide. Valleys are either U-shaped or V-shaped and their shape and type of characterized by their formation.
Erosion by rivers is the main valley forming process; other processes such as the movement of the earth’s crust and glaciers, also have an important part in some cases.
Some valleys have rivers running through them and are referred to as river valleys.
Vale is a particularly wide river valley.
Glacial valleys are formed by glaciers and are usually U-shaped.
Hanging valleys are higher than the main valley and often create beautiful waterfalls at their outlet.
Giant valleys are formed when the earth’s crust splits or separates.
Hollows are small valleys between hills or mountains.
When valleys sink below sea level they become sunken valleys. Their shape makes a good harbor.
Very narrow valleys with high side walls are often referred to as gorges.
Valleys that are deep and wide are referred to as canyons.
Rift valleys are created when the tectonic plates under the earth’s surface expand the crust.
There are three main types of valleys – the V-shaped valley, the flat-floored valley, and the U-shaped valley.
These valleys are formed by rivers; they have a V-shaped cross-section and very steep sides. These valleys are usually found near the source of a river due to the presence of a steeper bank; however, they can also be formed downstream. V-shaped valleys are formed by erosion. The river carries stones and rocks in its water. The force of the water and the grinding of rocks and stones cut down into the river bed to carve out a valley. Over time, the valley becomes deeper and wider.
A U-shaped valley is the shape left after a valley has been deepened by a glacier. The original V-shaped valley, which would have been made by a river, is widened and deepened after the ice has eroded the sides and bottom of the valley.
The third type of valley is called a flat-floored valley and is the most common type in the world. These valleys, like V-shaped valleys, are formed by streams, but they are usually older, or more developed. As the slope of a stream’s channel becomes smooth and begins to smooth the steep V or U-shaped valley, the valley floor gets wider. Over time, the stream continues to erode the valley’s soil, widening it further. During this process, the shape of the valley changes from a V or U-shaped valley into one with a broad flat valley floor. An example of a flat-floored valley is the Nile river valley.
