Indian Drainage System

Drained basin: - The area drained by single river is known as drained basin.

Water divide: - An upland that separate two drainage basin is known as water divide.

Indian rivers are divided into two major group.

●       the Himalayan rivers

●       the Peninsular rivers

A river with its tributary is called river system.

Himalayan rivers

The river originates in the Himalayan. The Himalayan rivers are perennial rivers, means they have water throughout the year. These rivers receive water from rain as well as from melted snow from the mountains. Himalayan river system divided into Indus river system and Ganga-Brahmaputra river system.

Indus river system: -

Indus river rise in Tibet near lake Mansarowar. Flowing west, it enters India in the Ladakh district of Jammu and Kashmir. Several tributaries, the Zaskar, the Nubra, the Shyok and the Hunza, join it in the Kashmir region. The Indus flows through Baltistan and Gilgit and emerges from the mountains at Attock (pakistan).The Satluj, the Beas, the Ravi, the Chenab and the Jhelum join together to enter the Indus near Mithankot in Pakistan. Beyond this, the Indus flows southwards eventually reaching the Arabian Sea, east of Karachi. The Indus plain has a very gentle slope.

According to the regulations of the Indus Water Treaty (1960), India can use only 20 per cent of the total water carried by Indus river system. This water is used for irrigation in the Punjab, Haryana and the southern and western parts of Rajasthan.

The Ganga River : - 

It originate Gangotri Glacier, the head of ganga known as ‘Bhagirathi’ and joined by the Alaknanda at Devaprayag in Uttarakhand. At Haridwar the Ganga emerges from the mountains on to the plains. The rivers join ganga from himalyan are the Yamuna, the Ghaghara, the Gandak and the Kosi.

The river Yamuna rises from the Yamunotri Glacier in the Himalayas. It flows parallel to the Ganga and as a right bank tributary, meets the Ganga at Allahabad. The Ghaghara, the Gandak and the Kosi rise in the Nepal Himalaya. They are the rivers, which flooded parts of the northern plains every year, causing widespread damage to life and property but enriching the soil for the extensive agricultural lands.

The main tributaries, which come from the peninsular uplands, are the Chambal, the Betwa and the Son.

the Ganga flows eastwards till Farakka in West Bengal. This is the northernmost point of the Ganga delta. The river bifurcates(divide into two branches) here namely bhagirathi and Hooghly. The hooghly flow toward the south to the bay of bengal. The mainstream bhagirathi flows southwards into Bangladesh and is joined by the Brahmaputra. Further downstream, it is known as the Meghna and flow into the bay of bengal. The delta is known as Sunderban delta (Delta derived its name from the Sundari tree which grows well in marshland). It is the world’s largest and fastest growing delta. It is also the home of Royal Bengal tiger.

The Brahmaputra River System: -

The Brahmaputra rises in Tibet east of Mansarowar lake very close to the sources of the Indus and the Satluj. It is slightly longer than the Indus, and most of its course lies outside India. it originate in Chemayungdung Glacier in Tibet. In Tibet it is called Tsangpo(purifier) or Yarlung Zangbo. It flow eastwards parallel to the Himalayas. On reaching the Namcha Barwa it takes a ‘U’ turn and enters India in Arunachal Pradesh through a gorge, Here, it is called the Dihang and it is joined by the Dibang, the Lohit, and many others. In Bangladesh it is known as Jamuna.

In Tibet the river carries a smaller volume of water and less silt as it is a cold and a dry area. In India it passes through a region of high rainfall. Here the river carries a large volume of water and considerable amount of silt. The Brahmaputra has a braided channel in its entire length in Assam and forms many riverine islands. The island’s name is Majuli or Majoli. It is world’s largest riverine island and the first Indian island district. 

Every year during the rainy season, the river overflows its banks, causing widespread devastation due to floods in Assam and Bangladesh. Unlike other north Indian rivers the Brahmaputra is marked by huge deposits of silt on its bed causing the river bed to rise. The river also shifts its channel frequently.

Peninsular rivers

Most of the major rivers of the Peninsula such as the Mahanadi, the Godavari, the Krishna and the Kaveri flow eastwards and drain into the Bay of Bengal. These rivers make deltas at their mouths. There are numerous small streams flowing west of the Western Ghats. The Narmada and the Tapi are the only long rivers, which flow west and make estuaries. The drainage basins of the peninsular rivers are comparatively small in size.

A large number of the Peninsular rivers are seasonal, as their flow is dependent on rainfall. During the dry season, even the large rivers have reduced flow of water in their channels. The Peninsular rivers have shorter and shallower courses as compared to their Himalayan counterparts. They are older than Himalaya Rivers.

The Mahanadi basin: -

The Mahanadi rises in the highlands of Chhattisgarh.It flows through Odisha to reach the Bay of Bengal.its tributries are Sheonath, Hasdeo, Mand.Its drainage basin is shared by Maharashtra, Chhattisgarh, Jharkhand, and Odisha.

The Narmada Basin: -

The Narmada rises in the Amarkantak hills in Madhya Pradesh. It flows towards the west in a rift valley formed due to faulting. The Narmada basin covers parts of Madhya Pradesh and Gujarat.

On its way to the sea, the Narmada creates many picturesque locations, The ‘Marble rocks’, near Jabalpur where the Narmada flows through a deep gorge, and the ‘Dhuadhar falls’ where the river plunges over steep 

The Godavari Basin: -

It is the largest Peninsular River. It is also known as dakshin ganga. It rises from the slopes of the Western Ghats in the Nasik district of Maharashtra. It drains into the Bay of Bengal. Its drainage basin is also the largest among the peninsular rivers. The basin covers parts of Maharashtra (about 50 per cent of the basin area lies in Maharashtra), Madhya Pradesh, Odisha and Andhra Pradesh. The Godavari is joined by a number of tributaries such as the Purna, the Wardha, the Pranhita, the Manjra, the Wainganga and the Penganga. The last three tributaries are very large.

The Krishna Basin: -

Rising from a spring near Mahabaleshwar, the Krishna flows for about 1400 km and reaches the Bay of Bengal. It’s tributaries are the Tungabhadra, the Koyana, the Ghatprabha, the Musi and the Bhima. its basin is shared by Maharashtra, Karnataka and Andhra Pradesh.

The Kaveri Basin: -

The Cauvery rises in the Brahmagiri range (karnataka) of the Western Ghats and it reaches the Bay of Bengal in south of Cuddalore, in Tamil Nadu. Its main tributaries are Amravati, Bhavani, Hemavati and Kabini.Its basin drains parts of Karnataka, Kerala and Tamil Nadu.

The Tapi Basin: -

The Tapi rises in the Satpura ranges, in the Betul district of Madhya Pradesh. It also flows in a rift valley parallel to the Narmada but it is much shorter in length. Its basin covers parts of Madhya Pradesh, Gujarat and Maharashtra.