Valleys
A valley is a low area of land between hills or mountains, typically with a river or stream flowing through it. Valleys are one of the most common landforms on the surface of the planet. There are three main types of valleys, the V-shaped valley, the flat floored valley and the U-shaped valley.
V Shaped Valleys
V shaped valleys are valleys 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.
V Shaped Valleys
V shaped valleys are valleys 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.
U-Shaped Valleys
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.
For more information go to......
http://www.scalloway.org.uk/phyl12.htm
Or.......
http://library.thinkquest.org/TQ0311164/v-valley.htm
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.
For more information go to......
http://www.scalloway.org.uk/phyl12.htm
Or.......
http://library.thinkquest.org/TQ0311164/v-valley.htm
Flat Floored Valleys
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.
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.
Rift Valleys
A rift valley forms where the Earth’s crust is spreading or splitting apart. This kind of valley is often narrow, with steep sides and a flat floor.
Many rift valleys have been found underwater, along the large ridges that run throughout the ocean. These ocean ridges are formed as tectonic plates move away from one another.
For more information go to...
http://education.nationalgeographic.com.au/education/encyclopedia/rift-valley/?ar_a=1
A rift valley forms where the Earth’s crust is spreading or splitting apart. This kind of valley is often narrow, with steep sides and a flat floor.
Many rift valleys have been found underwater, along the large ridges that run throughout the ocean. These ocean ridges are formed as tectonic plates move away from one another.
For more information go to...
http://education.nationalgeographic.com.au/education/encyclopedia/rift-valley/?ar_a=1
What climates are they found in?
Valleys record extremes of temperatures in summer and winter. The deeper a valley is, the more the fluctuation of temperature. This means that the valleys which are surrounded by very high mountains can have very large changes in temperature.
"If you've ever driven up to a mountain pass, you know that the higher you climb, the colder it gets. But on clear, calm days, it can actually be colder in the valleys. That's because under high-pressure systems, cold air slides down mountain slopes and pools down below."(http://www.scientificamerican.com/podcast/episode.cfm?id=mountain-vs-valley-temps-stretch-ap-10-04-28)
Valleys record extremes of temperatures in summer and winter. The deeper a valley is, the more the fluctuation of temperature. This means that the valleys which are surrounded by very high mountains can have very large changes in temperature.
"If you've ever driven up to a mountain pass, you know that the higher you climb, the colder it gets. But on clear, calm days, it can actually be colder in the valleys. That's because under high-pressure systems, cold air slides down mountain slopes and pools down below."(http://www.scientificamerican.com/podcast/episode.cfm?id=mountain-vs-valley-temps-stretch-ap-10-04-28)
Flora and Fauna
There are usually rivers in valleys, meaning that there will be all sorts of wildlife in the water as well as out. What flora and fauna you find in a valley depends on the weather conditions, amount of water, and the location of the valley.
To read about the flora and fauna in the Wollombi Valley, go to.......
http://wollombi.nsw.au/flora-fauna/plants.cfm
Or to read about the flora and fauna in the Avon Valley go to.........
http://parks.dpaw.wa.gov.au/sites/default/files/downloads/parks/AVNP_Flora_Fauna.pdf
There are usually rivers in valleys, meaning that there will be all sorts of wildlife in the water as well as out. What flora and fauna you find in a valley depends on the weather conditions, amount of water, and the location of the valley.
To read about the flora and fauna in the Wollombi Valley, go to.......
http://wollombi.nsw.au/flora-fauna/plants.cfm
Or to read about the flora and fauna in the Avon Valley go to.........
http://parks.dpaw.wa.gov.au/sites/default/files/downloads/parks/AVNP_Flora_Fauna.pdf
For more information about valleys go to.....
http://www.scienceclarified.com/landforms/Ocean-Basins-to-Volcanoes/Valley.html
Or.....http://geography.about.com/od/physicalgeography/a/valleyformation.htm
http://www.scienceclarified.com/landforms/Ocean-Basins-to-Volcanoes/Valley.html
Or.....http://geography.about.com/od/physicalgeography/a/valleyformation.htm