The cross profile of a river shows how the width and depth of the river valley and channel change as you travel downstream. Near the source of a river there is more vertical erosion as the river flows downhill, using its energy to overcome friction (A).
What is the meaning of cross profile?
What is a cross-profile? River cross profiles show you a cross-section, taken sideways, of a river’s channel and/or valley at certain points in the river’s course. A channel cross-profile only includes the river whereas a valley cross-profile includes the channel, the valley floor and the sides of the valley.
What is a river long profile and cross profile?
A cross profile shows a cross-section of a river’s channel and valley at a certain point along the river’s course. A – as the river flows downhill there is an increase in vertical erosion . The channel is shallow and narrow because there is not a lot of water in the channel.
Why does the cross profile of a river change?
As the river flows downstream it is joined by tributaries, increasing the volume of water, velocity and therefore its erosive power. This enables it to cut a deeper channel as it flows downstream. Downstream, the channel becomes wider as the gradient becomes more gentle leading to less vertical erosion.
What is river profile in geography?
river profile The slope along the bed of a river, expressed as a graph of distance-from-source against height.
What does long profile of a river mean?
The long profile of a river is a way of displaying the channel slope of a river along its entire course.As more streams and tributaries join the river, roughness decreases, discharge and velocity increases and the erosive power of bed load will decrease.
What does cross-section?
Definition of cross section
1a : a cutting or piece of something cut off at right angles to an axis also : a representation of such a cutting. b : section sense 3b. 2 : a measure of the probability of an encounter between particles such as will result in a specified effect (such as scattering or capture)
How does the profile of a river change downstream?
As a river flows down steep slopes, the water performs vertical erosion . This form of erosion cuts down towards the river bed and carves out steep-sided V-shaped valleys.As the river moves from the source to the mouth – both the depth of the river and the width of the river will both increase.
How important is the cross-section drawing?
Cross sections help make plans easier to construct by supplying more detail about both the structure and enclosure. As designs become more complicated and have more parts, more cross sections with various views become necessary.
What does cross-section drawing mean?
In technical drawing a cross-section, being a projection of an object onto a plane that intersects it, is a common tool used to depict the internal arrangement of a 3-dimensional object in two dimensions.
How does the River Severn change from source to mouth?
The River Severn
The Severn swiftly grows and forms a V-shaped valley. The river transports a large load, which allows rapid erosion to take place. Waterfalls and gorges have been formed in the upper course. As the gradient decreases, meanders can be found.
Why does the cross sectional area of a river increase downstream?
It’s well known that rivers increase in size as they transport water from their source in their headwaters to the mouth. The river channel becomes wider and deeper and as a result its cross-sectional area increases.
Why is the cross section of a river important?
Cross sections are located at intervals along a stream to characterize the flow carrying capability of the stream and its adjacent floodplain. They should extend across the entire floodplain and should be perpendicular to the anticipated flow lines.
What are the 3 stages of a river?
Nearly all rivers have an upper, middle, and lower course.
- Young River – the upper course.
- Middle Aged River – the middle course.
- Old River – the lower course.
How do you find the cross sectional area of a river?
Cross-sectional area (A in the formula) is the product of stream width multiplied by average water depth.
How does a river shape the land?
Rivers begin high up in the mountains so they flow quickly downhill eroding the landscape vertically.The river transports the rocks downstream and the channel becomes wider and deeper creating a V-shaped valley between interlocking spurs.
Where is the steepest gradient in the long profile of a river?
upper course
The steepest gradient in the long profile of a river is found in the upper course near to the source.
How and why does discharge change along the long profile of a river?
As more water enters the river from tributaries the channel becomes deeper as discharge increases. The increase in energy leads to less vertical erosion and leads to lateral erosion on meanders. The gradient of the long profile becomes more concave as the vertical erosion reduces.
What is an example of a cross section?
The definition of a cross section is a section of something that has been cut down the middle to show what is inside. An example of a cross section is what you see on the inside when you cut a layered sandwich in half.
What is cross section formula?
Cross-Sectional Area of a Rectangular Solid
The volume of any rectangular solid, including a cube, is the area of its base (length times width) multiplied by its height: V = l × w × h. Therefore, if a cross section is parallel to the top or bottom of the solid, the area of the cross-section is l × w.
What does cross section area mean?
The cross-sectional area is the area of a two-dimensional shape that is obtained when a three-dimensional object – such as a cylinder – is sliced perpendicular to some specified axis at a point. For example, the cross-section of a cylinder – when sliced parallel to its base – is a circle.
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