DRAINAGE OF INDIA

River Basins of India

River basins or drainage basins include all the areas from which the river receives its water. It is also known as Watershed.
On the basis of the area drained, the river basins of India have been classified have been classified into three categories.
-River basins with catchment areas of more than 20000 sq. Km are known as large river basins.
-River basins have a catchment area between 2000 to 20000 sq km are known as the medium basins, and
- the rivers have a catchment area of less than 2000 sq km known as minor river basins.
The major river Basins of India in the descending order of area are- the Ganga, Indus Godavari, Krishna, Brahmaputra, lung, Mahanadi, Narmada, Kaveri, Tapi, pennant, Brahmani, Barak, Mahi, Sabarmati, and subarnarekha.
these major river basins form about 81% of the total drainage area of the country.

Himalayan and Peninsular Drainage:
On the basis of mode of origin, the drainage of India may be divided into (i) Himalayan or the ExtraPeninsular Drainage, and (ii) the Peninsular Drainage.
There is no clear-cut line of demarcation between these two drainage systems, as many of the Peninsular rivers like the Chambal, Betwa, Sind, Ken, and Son are much older in age and origin than the Himalayan rivers.
The tributaries of the Himalayan rivers, although some of them are originated from the Peninsular region, are classified as a part of the Himalayan River basin. E.g., Banas, Chambal, Sind, Betwa, Ken which are the tributaries of Yamuna are considered as part of the Himalayan River basin although originating from the Peninsular region.

Himalayan Drainage:

The Himalayan drainage system comprises all the international rivers of India. i.e., the Indus, the Ganga, and the Brahmaputra.
Most of these rivers and their major tributaries are perennial in character, obtaining their water from the glaciers and rains.
These rivers are in their youthful stage carving out a number of erosional landforms like waterfalls,cataracts, rapids, gorges, steep slopes, and river terraces.
The Himalayan rivers are not only eroding agents but are depositing agents in the plains and deltas.
The great Himalayan rivers (Indus, Sutlej, Ganga, Kali, Karnali, Gandhak, Kasi, Tista, and Brahmaputra) are older than the Greater Himalayas. They are antecedent and drain not only the southern slopes of the Himalayas but to a large extent, the northern Tibetan slopes as well.

Antecedent Rivers

Antecedent Rivers are the rivers, present even before the formation of mountains.
These rivers cut through ranges and ultimately, they will form steep gorges.
There are six river basins in India that are antecedent .
The Himalayan courses of these rivers are highly tortuous, but in plains, they display a strong meandering tendency and shift their courses frequently.
The river regimes, although perennial, exhibit wide seasonal fluctuations causing devastating floods during any season but shrinking to the bottom of the valley with a number of shoals during the dry season.
These rivers continue to cause intensive erosion and transport heavy loads of sand and silt annually.
The Himalayan rivers have great socioeconomic and cultural importance in the life of the Indian people. The water of the Himalayan rivers is utilized for irrigation, industries, hydel-power generation, navigation, and domestic purposes. Moreover, the big rivers are navigable in the plain areas of their courses.

MAJOR RIVERS OF THE HIMALAYAN REGION:

Major Himalayan (Extra-Peninsular) Rivers of India

River	Source	Length (km)	Main Tributaries
The Indus	Glacier Bokhar chu in the Mt. Kailash	2880	Jhelum, Chenab, Ravi, Beas, Satluj
The Jhelum	Chashma Verinag in the Kashmir Valley	725 km (India: 165 km)	Sandran River, Bringhi river, Aripath, Rambiara Stream, Romuhi stream, Sasara Stream, Nallah Lidder, Nallah Sindh, Nallah Vishow, Dudhganga River, Pohore
The Chenab (Chandrabhaga)	Lahaul Valley of Himachal Pradesh	960	Stream Chandra, Stream Bhaga, The Miyar Nallah, The Bhut Nallah, The Marusudar, The Tawi River, The Niru
The Ravi	Near Rohtang Pass	725	River Bhadal, River Siul, River Baira, River Tant Gari
The Beas	Beas Kund near Rohtang Pass	460	Bain, Bangana, Luni, Uhal, Banner, Chakki, Gaj, Harla, Mamuni, Parvati, Patikuhal, Sainj, Suketi, Tirthan
The Satluj	Manasarovar-Rakas lakes	1450 km (India: 1050 km)	Baspa, Spiti, Nogli khad, Soan
The Ganga (Bhagirathi)	Gangotri Glacier in Garhwal, Himalaya	2525	Gomti, Ghaghara, Gandaki, Kosi, Yamuna, Son, Punpun, Damodar
The Yamuna	Yamunotri Glacier near Bandarpunch Peaks in the Mussoorie	1376	Tons, Chambal, Hindon, Betwa, Ken, Giri, Sind, Uttangan, Sengar, Rind
The Brahmaputra	Kailash Ranges	2900	Lohit, Dibang, Subansiri, Jiabharali, Dhansiri, Manas, Torsa, Sankosh, Teesta, Burhidihing, Desang, Dikhov, Dhansiri, Kopili

INDO-BRAHMA THEORY

The theory essentially believes that there was a very large river (Inda-Brahma River) starting from Assam in the east, flowing towards the west, and was draining into the Arabian Sea.
During the formation of the Himalayas, the rivers in such regions captured other rivers (tributaries of these rivers captured), and ultimately, they became the Himalayan Rivers.
It is said that, with the formation of the Himalayas, there was the breaking of these rivers, and they today formed the Himalayan drainage basin.
The theory assumes that there should be the presence of such big rivers which transformed into present types of river basins in India. However, evidence (depositional evidence) rejected the assumptions. The depositional evidence suggests that normally near the source of rivers, there should be more coarser materials. However, we find that in Assam, there are lots of limestone rocks that are generally present near the mouth of the rivers. So, this theory cannot be validated and thus the theory has been rejected.
To summarize, the theory says that there were two rivers, the Inda-Brahma River and the Shivalik River. They were dismembered and broken down during the formation of the Himalayas. Lots of other Geomorphological processes such as river capturing, etc., led to the evolution of present drainage basins.

PENINSULAR DRAINAGE:

The peninsular drainage system is older than the Himalayan one. This is evident from the broad, largely graded shallow valleys, and the maturity of the rivers.
The Western Ghat running close to the western coast acts as the water divide between the major Peninsular Rivers, discharging their water in the Bay of Bengal and as small rivulets joining the Arabian Sea.
Most of the major Peninsular Rivers except Narmada andTapi flow from west to east.
The Chambal, the Sind, the Betwa, the Ken, the Son, originating in the northern part of the Peninsula belong to the Ganga River system.
The other major river systems of the Peninsular drainage are -the Mahanadi, the Godavari, the Krishna, and the Kaveri.
Peninsular rivers are characterized by fixed course, absence of meanders, and non-perennial flow of water. The Narmada and the Tapi which flow through the rift valley are, however, exceptions.

Major Peninsular Rivers of India

S. No.	River	Source	Length (km)	Main Tributaries
1	Godavari	Trimbak Plateau Near Nasik (Maharashtra)	1465	Sabari Indravati, Penganga, Wardha, Pranhita, Puma, Wainganga, Manjra, Tima, Pranhita, Moher
2	Krishna	Near Mahabaleshwar (Maharashtra)	1400	Musi, Muneru, Koyna, Nira, Muthu-Mula, Sina, Kagna, Bhima, Ghataprabha, Malprabha, Nira, Panchganga, Dudhganga, Tungbhadra
3	Narmada	Amarkantak	1310	Heran, Orsang, Barna, Kolar, Burnnar, Banjar, Shar, Shakkar, Dudhi, Tawa, Kundi
4	Mahanadi	Dandakaranya Plateau near Raipur	857	Ib, Mand, Hasdeo, Seonath, Ong, Jonk, Tel
5	Kaveri	Taal Kaveri	800	Herangi, Hemavati, Yogachi, Lokpavni, Shimsa, Arkavati, Kabani, Bhavani, Noyil, Amravathi, Sanmukta, Nanganji, Laxman-Tiratha, Suvarnavati, Turunananimutta
6	Tapi	Multai in Betul Distt. (MP)	730	Puma, Girna, Panjhira, Betul, Patki, Arunavati, Ganjal, Dhatranj, Aner, Bokad, Mon, Guli

Comparisons between Himalayan and Peninsular Drainage:

Peninsular Rivers	Extra-Peninsular Rivers
The rivers of Peninsular India are much older. Some of them are as old as the Precambrian period.	The rivers of extra-Peninsular India are much younger except a few antecedent rivers like Indus, Sutlej, Ganga, Brahmaputra, etc.
They are mostly consequent or rejuvenated rivers.	Many of them like Sutlej, Kali, Kosi, Brahmaputra, Tista, are inconsequent rivers.
These rivers, except Godavari, have relatively small basins.	These rivers generally have large basins.
The channels of these rivers are broad.	The channels of these rivers in the upper courses form gorges, waterfalls, and rapids.
There is hardly any vertical erosion.	Both vertical and lateral erosion are significant.
These are slow-moving.	These are both swift and have sluggish movements.
These have a low carrying capacity.	They transport huge quantities of sediments.
These are mainly depositional agents.	These are active erosional and depositional agents.
They make shallow meanders.	In the plains, they make numerous sharp meanders and ox-bow lakes.
These are generally not navigable.	Most of them are navigable in the plains.
These are mostly seasonal.	These are perennial.
Most of them originate from the Western Ghats and Plateau.	Most of them originate from the Himalayan Glaciers.
Most of them are in the senile stage.	Most of them are in the late youth stage.
There is no river capturing.	River capturing is a common phenomenon.
These rivers have been harnessed for the generation of Hydel power. E.g., Hirakund, Koyna, Nagarjuna Sagar	There are numerous multi-purpose projects on these rivers, e.g., Bhakra, Tehri, Salal, etc.
These rivers make deltas (Godavari, Krishna, Kaveri) and estuaries like Narmada and Tapi.	These rivers make only deltas. The Sundarbans Delta is the largest in the world.
Their channels are near the base level.	These rivers are in the ending part of the youth stage. In their mountainous course, they do river capturing.

These have a low carrying capacity.	They transport huge quantities of sediments.
These are mainly depositional agents.	These are active erosional and depositional agents.
They make shallow meanders.	In the plains, they make numerous sharp meanders and ox-bow lakes.
These are generally not navigable.	Most of them are navigable in the plains.
These are mostly seasonal.	These are perennial.
Most of them originate from the Western Ghats and Plateau.	Most of them originate from the Himalayan Glaciers.
Most of them are in the senile stage.	Most of them are in the late youth stage.
There is no river capturing.	River capturing is a common phenomenon.
These rivers have been harnessed for the generation of Hydel power. E.g., Hirakund, Koyna, Nagarjuna Sagar	There are numerous multi-purpose projects on these rivers, e.g., Bhakra, Tehri, Salal, etc.
These rivers make deltas (Godavari, Krishna, Kaveri) and estuaries like Narmada and Tapi.	These rivers make only deltas. The Sundarbans Delta is the largest in the world.
Their channels are near the base level.	These rivers are in the ending part of the youth stage. In their mountainous course, they do river capturing.

RIVER REGIMES

The pattern of the seasonal flow of water in a river is called its regime.
The main difference in the flow pattern of the Himalayan and the Peninsular rivers is caused by the differences in climate.
The Himalayan rivers are perennial, and their regimes are dependent on the pattern of water supply both from snowmelt and rainfall. Their regimes are monsoonal as well as glacial.
The regime of most of the peninsular rivers, on the other hand, are only monsoonal as they are controlled by rainfall alone. Even regimes of different peninsular rivers are not the same because of the differences in the seasonal distribution of rainfall in various parts of the plateau.

Himalayan River regime

The Ganga has minimum flow from January toJune. The maximum is attained in August or September. The rate of flow steadily falls after September. The Ganga has, thus, a typical monsoonal regime. However, there is enough water in this river before the monsoon rains mainly because of snowmelt in the Himalayas.
The Jhelum attains its maximum flow in June or even in May mainly because of the Himalayan snowmelt.
An interesting difference between the regimes of the two rivers is seen in the range of variation between the maximum and the minimum flow. This difference is sharper in the case of the Ganga than the Jhelum. The mean maximum discharge of the Ganga at Farakka is about 45,000 cusecs, while the mean minimum is only 1,300 cusecs. The Jhelum, however, has a less voluminous discharge, the respective mean maximum flow being 600 cusecs and the mean minimum 50 cusecs.

Peninsular River regime:

The Narmada has a very low volume of discharge from January to July which suddenly rises in August when the maximum is attained. The river, however, maintains its fall as spectacular as the rise in August.
The Godavari flows at a low level until May. It has a double maximum-one in May-June and the other in July-August. After August, there is a sharp fall in discharge, although the volume of flow in October and November is higher than in any of the months from January to May.
The mean maximum discharge of the Godavari at Polavaram is 3,200 cusecs, while the mean minimum flow is only 50 cusecs. The respective values for the Narmada, as recorded at Garudeshwar, are 2,300 cusecs and 15 cusecs.

Geography

Geography

Geography

Geography

Geography