What is a long profile of a river?

What is a long profile of a river?

The long profile of a river is a way of displaying the channel slope of a river along its entire course. As a result the gradient of the river will generally decrease creating a concave long profile with distance down stream, and deposition serves to enhance this phenomenon further.

What are the long profile and cross profile of a river?

The average flow velocity of a river increases along its long profile. This makes sense; along the profile, more potential energy is converted to kinetic energy, increasing the velocity. This is only the average velocity however; a cross-section of a river shows that the velocity varies from one side to the other.

What are the three sections that make up the long profile of a river?

Definition:

• The long profile of the river can be split into three main sections, the upper course, the middle course and the lower course, as the above diagram shows.
• Upper Course – often flows through a steep sided valley with a narrow channel.

Where is a river fastest?

1. Toward the middle of a river, water tends to flow fastest; toward the margins of the river it tends to flow slowest. 2. In a meandering river, water will tend to flow fastest along the outside bend of a meander, and slowest on the inside bend.

Why is a river wider at its mouth than at its source?

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. In the upper course of the river bedload is larger and more angular.

What is a transversal profile?

Transverse profiles runs deletion method, planimetric and altimetric lifting the details (geometric leveling), the direction perpendicular to the axis of the communication path, starting from the characteristic points marked on the ground, in the center of the track, which are found in longitudinal profile.

How is a waterfall formed?

Often, waterfalls form as streams flow from soft rock to hard rock. This happens both laterally (as a stream flows across the earth) and vertically (as the stream drops in a waterfall). In both cases, the soft rock erodes, leaving a hard ledge over which the stream falls.

What is river efficiency?

• The efficiency of a rivers channel is measured by finding its Hydraulic radius. It is the ratio between the length of wetted perimeter and cross section of a river channel.

Where is the steepest part of a river?

The steepest gradient in the long profile of a river is found in the upper course near to the source.

What does a cross profile of a river look like?

The cross profile shows what a cross-section of a river channel or river valley looks like. The river valley’s cross profile changes throughout the different stages of a river’s long profile. Upper stages – vertical erosion creates narrow valley floors and steep v-shaped valleys Middle stages – lateral erosion creates wider valleys.

Why is the long profile of a river important?

It spans the source of a river (where it starts) and the mouth (where it reaches the sea). The long profile of a river is a way of displaying the channel slope (gradient) of a river along its entire length. Therefore, it shows how a river loses height with increasing distance towards the sea.

What is the difference between the long profile and the cross section?

A long profile shows what is in it from one end to the other, that is, from the tributaries to the mouth. What is a cross section of a river? A cross section of a river is a profile across the river to see the depth of the river from one side to the other.

How does the shape of a river change?

A river changes shape as it flows from its source to its mouth. The shape of the long river profile and the cross river profile changes. Long profiles. The source of a river is often – but not always – in an upland area. Near the source, a river flows over steep slopes with an uneven surface. It often flows over a series of waterfalls and rapids.