Indian Drainage
There are two types of river systems in India. They are known as the Himalayan and Peninsular river systems. They differ on the basis of the evolution of their respective rivers.
The Himalayan Rivers:
The Himalayan river system consists of three major rivers namely the Indus, the Ganga and the Brahmaputra along with their tributaries. These rivers have a common characteristic feature of flowing parallel to the mountains and then bend suddenly towards the south. As they bend to flow towards the sea they cut deep gorges in the Himalayas. The gorges cut by these rivers clearly indicate that they existed before the Himalayas formed. Thus they are examples of antecedent drainage.
The Peninsular Rivers:
These rivers have broad, shallow valleys which indicate that they are much older than the Himalayan Rivers. They are involved in lateral cutting and most of them flow towards the east except the Narmada and Tapi which flow towards the west because they flow in troughs which haven’t been created by them. Due to the submergence of the western flank and the subsidence of the northern flank of the peninsular block the symmetry of the rivers was disturbed and trough – faulting occurred. Hence the Narmada and Tapi are examples of consequent drainage.
– The Himalayan River systems:
These systems include
– The Indus Drainage system
– The Ganga Drainage System
– The Brahmaputra Drainage system
The Indus drainage system:
This system consists of the Indus and its tributaries (the Jhelum, Chenab, Ravi, Beas and the Satluj)
– The Indus:
It originates in Tibet near Lake Mansarowar. It flows west and north – westward through Jammu and Kashmir. It is considered to be one of the largest rivers in the world with a length of about 2,880 kilometres. It flows south – westward across Pakistan to reach the Arabian Sea.
– The Jhelum:
This river originates from a spring in the south – eastern part of Vale in Kashmir. It then runs along the Indo – Pak border to join the Chenab in Pakistan.
– The Chenab:
This river is also known as the ‘Chandrabhaga’ in Himachal Pradesh. It flows north – westward and runs parallel to the Pir Panjal mountain range for some time. It then cuts a deep gorge in the Pir Panjal and flows southwards.
– The Ravi:
This river originates near the Rohtang pass. It flows towards the north – west from its place of origin. It then turns towards the south – west and cuts a deep gorge in the Dhaoladhar range. Since this river forms a part of the Indo – Pakistan boundary it has strategic significance. It joins the Chenab near Multan in Pakistan.
– The Beas:
The Beas originates near the Rohtang too. It cuts through the Dhaoladhar range and flows towards the west entering the Punjab plain. Then it flows south – westward and joins the Satluj.
– The Satluj:
This river originates in Tibet. It first flows towards the north – west and enters Himachal Pradesh. It then flows west and cuts deep gorges in the Himalayan ranges before entering the Punjab plain.
The Ganga Drainage system:
This river system includes the Ganga and its tributaries like the Yamuna and the Ghaghara. All the rivers in this system originate in the Himalayas.
– The Ganga:
The source of the Ganga lies at an altitude of 6,600 metres in the Himalayas. This river flows south – westward and cuts through the hills near Haridwar. The total length of the Ganga is about 2,500 kilometres. It also flows south – eastward to enter Bangladesh where it is known as the Padma. The Padma then joins the Brahmaputra and flows into the Bay of Bengal.
– The Yamuna:
This river is a right – bank tributary of the Ganga and originates from the Yamunotri glacier which lies at an altitude of 3,900 metres. It cuts a deep gorge across the lesser Himalayas and flows south – westward to enter the Ganga plain. The length of the Yamuna is about 1,300 kilometres.
– The Ghaghara:
It originates in the Himalayas and cuts across the western part of the Himalayas in Nepal to join the Ganga. This river has a habit of shifting its course.
The Brahmaputra drainage system:
It runs parallel to the north of the Himalayas for about 1,200 kilometres. It is known as the Tsang – po in Tibet. It then takes a southward turn and enters Arunachal Pradesh as the Dihang River. It then flows south – westward to enter Bangladesh where it joins the Ganga and forms the largest delta in the world. It has a total length of about 2,900 kilometres and is an example of antecedent drainage. This river also causes frequent floods.
The Peninsular Rivers:
All the major rivers in the peninsular originate from the Western Ghats and flow towards the east to meet the Bay of Bengal. These rivers are the Mahanadi, the Godavari, the Krishna and the Cauvery. The Narmada and the Tapi are the only rivers which flow towards the west through rift valleys draining into the Arabian Sea.
Rivers flowing into the Bay of Bengal:
– The Mahanadi:
It flows through Orissa and into the Bay of Bengal. The drainage basin is shared by Madhya Pradesh, Orissa, Bihar, and Maharashtra. It has a length of approximately 850 kilometres.
– The Godavari:
It is the largest peninsular river in India. It originates in Maharashtra and joins the Bay of Bengal in Andhra Pradesh after flowing through Madhya Pradesh, Karnataka and Orissa. It has a length of about 1,450 kilometres.
– The Krishna:
A spring near Mahabaleshwar feeds this river. It has a length of about 1,400 kilometres. It flows through Maharashtra, Karnataka and Andhra Pradesh.
– The Cauvery:
It rises in the Western Ghats and drains into the Bay in Andhra Pradesh after flowing for about 800 kilometres. This is probably the only river fed by water throughout the year. It receives water from the south – west monsoon winds and the retreating north – east monsoons.
Rivers flowing into the Arabian Sea:
– The Narmada:
Its source is located in Madhya Pradesh. It flows towards the west and has a length of about 1,300 kilometres. One – tenth of its basin lies in Gujarat while the rest lies in Madhya Pradesh. It flows through gorges which cut through marble rocks.
– The Tapi:
This river originates in Madhya Pradesh and flows westwards in a trough which is parallel to the Narmada. It has a length of approximately 720 kilometres. It flows through Madhya Pradesh, Maharashtra and Gujarat.
The Sabarmati and the Mahi are two rivers which drain the north – western flank of the peninsular. They originate in the Aravali range in Rajasthan and flow towards the Arabian Sea.