What is the upper course of a river called?
If we look into the whole length of a river we will notice that it has three definite courses: 1. The Upper or Mountain Course 2. The Middle or Plain Course 3. The Lower or Deltaic Course.
Why does the upper course of a river valley has a different cross profile from the lower course?
The cross profile of a river changes as it moves from the upper to lower course as a result of changes in the river’s energy and the processes that the river carries out. In the upper course, the valley and channel are narrow and deep as a result of the large amount of vertical erosion and little lateral erosion.
What is the cross profile of a river?
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 channel shape in the upper course of a river?
V-shaped
As the river moves through the upper course, it cuts downwards. The gradient here is steep and the river channel is narrow. Vertical erosion in this highland part of the river helps to create steep-sided V-shaped valleys, interlocking spurs, rapids, waterfalls and gorges.
What is the course of river Ganga?
From the confluence of river Bhagirathi and river Alaknanda at Devprayag, the river is known as Ganges. The upper course stretches from the source till Hardwar. Bhagirathi-Hooghly which passes through West Bengal and the otherPadma (main branch) which passes through Bangladesh and both drains to the Bay of Bengal.
What is the work of a river in its upper course?
The main function of a river in its upper course is erosion. It erodes its bed and banks and carries large boulders of rock with it. The landforms formed in the upper course of a river are V-shaped valley and waterfall.
What processes happen in the upper course of a river?
VERTICAL EROSION is the main process in the upper course of the river, as the river wants to get to sea level. This process creates five distinctive features; a v- shaped valley, interlocking spurs, waterfalls, gorges and rapids. These occur when there are horizontal bands of hard and soft rock.
Why does the cross profile of a river change downstream?
In the upper course, the river erodes its bed by hydraulic action and abrasion. 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.
How does a river change from upper to lower course?
The river channel gets deeper and wider as the bed and banks are eroded. The sediment load of the river gets smaller in size. Small meanders and a small floodplain can be found in this part of the river. Lower course – the final course of the river is where the land is a lot flatter.
What is the longitudinal profile of a river?
Longitudinal profiles are plots of the elevation vs distance from the stream mouth to the upper reaches within watershed basin. They help to establish relationship between slope steepness and distance from the upper to lower reaches. Slope or gradient can be measured in degree or percentage (rise over run).
What is the work of river in upper course?
What are the two Headstreams of Ganga?
The Ganges rises in the southern Great Himalayas, and its five headstreams—the Bhagirathi, the Alaknanda, the Mandakini, the Dhauliganga, and the Pindar—all rise in the mountainous region of northern Uttarakhand state. The two main headstreams are the Alaknanda and the Bhagirathi.
Why does a river have a V shaped cross profile?
A steep, V-shaped cross-profile is typical in the upper course. This is because of vertical erosion by the river combined with weathering and mass movement of the valley slopes. In the middle course, the river is flowing through lower lying land.
Where does the Ganges River originate in India?
The Ganges River originates in the Great Himalayas on the Indian side of its boundary with the Tibet Autonomous Region. The six headstreams of the river Ganga namely, the Alaknanda, Bhagirathi, Dhauliganga, Mandakini, Nandakini, and Pindar all originate from the mountainous regions in the northern part of the Indian State of Uttarakhand.
Are there any gorges in the Brahmaputra River?
Sometimes, the river flows through very hard rocks. In that situation the two sides of the river become so steep that they become almost vertical. The formation is known as Gorge. There are many gorges on the upper course of the Brahmaputra, the Indus, and the Ganges.
How is the middle course of a river different from the upper course?
As a river leaves the hilly area and enters into a plain, its middle course starts. The slope of the river bed is less on a plain. Hence, the speed of the current is also less, compared to the upper course. The river is fed by many tributaries and its volume of water increases.