Drainage Systems in India

Drainage system means the network of rivers and their tributaries. Exam tip: connect drainage with river arrangement.

A drainage basin is the area drained by a river and its tributaries. Exam tip: understand basin as a river area.

A water divide is a ridge, upland, or other elevated land that separates two drainage basins. Rain falling on one side of the divide flows through streams and rivers toward one basin, while water falling on the other side flows toward another basin. It is therefore a natural boundary between river systems, even though it may not look like a sharp line on the ground.

A delta forms where a river deposits sediment near its mouth. The mouth is the place where a river ends by entering a lake, sea, or another river. A lagoon is a shallow coastal water body partly separated from the sea. These meanings do not describe high land between basins. Hence, option C, water divide, is correct.

Indian rivers are mainly studied as Himalayan and Peninsular systems. Exam tip: remember this basic classification.

Himalayan rivers get water from melting snow and rainfall. Exam tip: link perennial with water throughout the year.

Peninsular rivers depend more on rainfall. Exam tip: connect seasonal rivers with monsoon rainfall.

Indus, Ganga and Brahmaputra are major Himalayan river systems. Exam tip: remember them as one group.

The Indus originates near Lake Mansarovar in Tibet. Exam tip: place Indus in the Himalayan river system.

Jhelum, Chenab, Ravi, Beas and Satluj are major tributaries of the Indus system. Exam tip: remember the five rivers of Punjab.

The direct answer is B: Gangotri Glacier. In school geography, the Bhagirathi is identified as rising from the Gangotri Glacier in Uttarakhand. The Bhagirathi flows onward and meets the Alaknanda at Devprayag. From that meeting point, the combined river is called the Ganga. Therefore the question’s clue “Bhagirathi stream” leads directly to Gangotri Glacier. Option B is correct. Option A, Siachen, is a glacier in the Karakoram region and is not the source named for the Bhagirathi. Option C, Pindari, is associated with a different Himalayan river valley and is not the source of the Bhagirathi. Option D, Milam, is another Himalayan glacier but not the standard source given for the Bhagirathi or Ganga in this lesson. A careful exam cue is: Gangotri Glacier gives Bhagirathi; Bhagirathi and Alaknanda meet at Devprayag; after that the river is called Ganga.

Bhagirathi and Alaknanda meet at Devprayag. Exam tip: remember Devprayag for the beginning of the name Ganga.

The Ganga enters the plains near Haridwar. Exam tip: connect Haridwar with Ganga's entry into the plains.

Yamuna is one of the most important tributaries of the Ganga. Exam tip: connect Yamuna with the Ganga system.

Son is a major right-bank tributary of the Ganga. Exam tip: remember left-bank and right-bank tributaries separately.

The direct answer is C: Kosi. The Kosi is a major tributary of the Ganga and is especially famous for serious floods in northern Bihar. It carries large amounts of sediment, and its channel has historically shifted, so floodwater can spread widely over the surrounding plains. Option C is correct because flood risk and changing course are key textbook associations of the Kosi. Option A, Son, is also a Ganga tributary but is not the specially noted answer for this flood association. Option B, Chambal, joins the Yamuna system and is not usually identified in this question as the Ganga tributary famous for floods. Option D, Betwa, also joins the Yamuna and is not the intended river. The answer must be chosen by the strongest textbook clue, not merely by asking whether a river can ever flood. Memory cue: “Kosi” is commonly remembered as the “sorrow of Bihar” because of its destructive floods and shifting course.

The Brahmaputra enters India through Arunachal Pradesh. Exam tip: connect Brahmaputra with north-eastern India.

The direct answer is option A, Tsangpo, also written as Tsangpo or Yarlung Tsangpo. The Brahmaputra begins in the Tibetan region and is known there by this name. As it flows through different regions, its name changes: in Tibet it is commonly called Yarlung Tsangpo, in Arunachal Pradesh it is known as the Siang or Dihang, and after entering Assam it is called the Brahmaputra. Option A is correct because Tsangpo is the Tibetan name asked for. Option B, Bhagirathi, is a headstream of the Ganga in Uttarakhand, not the Tibetan name of the Brahmaputra. Option C, Satluj, is another major Himalayan river that also rises in Tibet, but it is a separate river. Option D, Damodar, is an eastern Indian river associated mainly with Jharkhand and West Bengal. The important reasoning is to connect the river’s location and changing names, not to choose any river merely because it is Himalayan. Memory cue: Tibet—Tsangpo; Arunachal—Siang or Dihang; Assam—Brahmaputra.

Ganga and Brahmaputra together form the Sundarbans Delta. Exam tip: connect Sundarbans with Ganga Brahmaputra.

The direct answer is option C, Godavari. Peninsular India means the old plateau region south of the Northern Plains. Its important rivers generally depend more on seasonal rain than on melting snow. The Godavari rises near Nashik in Maharashtra and flows eastward across the Deccan Plateau before entering the Bay of Bengal. Its length is about 1,465 km, making it the longest river of Peninsular India. It is often called the Dakshin Ganga, meaning the Ganga of the south. Option A, Krishna, is an important east-flowing peninsular river, but it is shorter than the Godavari. Option B, Cauvery, is also an important southern river, but it is much shorter. Option C is correct because the Godavari has the greatest length among the listed peninsular rivers. Option D, Narmada, is a major west-flowing river, but its length is less than that of the Godavari. Do not confuse the longest river of all India with the longest river of Peninsular India. Memory cue: Godavari = longest peninsular river = Dakshin Ganga.

Godavari flows eastward into the Bay of Bengal. Exam tip: connect east-flowing Peninsular rivers with deltas.

Narmada flows westward into the Arabian Sea. Exam tip: remember Narmada as a west-flowing river.

The Narmada rises near Amarkantak, flows westward through a rift valley, and drains into the Arabian Sea. Godavari, Krishna, and Kaveri flow eastward into the Bay of Bengal. Exam tip: Remember Narmada and Tapi as major west-flowing Peninsular rivers.

Narmada and Tapi form estuaries on the western coast. Exam tip: do not consider them delta-forming rivers.

Mahanadi flows eastward into the Bay of Bengal. Exam tip: remember Mahanadi as an east-flowing river.

Correct answer: A, the Peninsular river system. The Krishna is a major river of Peninsular India. It rises in the Western Ghats and flows generally eastward across the Deccan region before entering the Bay of Bengal. It is commonly studied with other important Peninsular rivers such as the Godavari and the Kaveri. B is incorrect because Himalayan rivers, such as the Ganga, Yamuna and Brahmaputra, originate in or near the Himalaya; the Krishna does not. C is incorrect because the Krishna is not a desert river and carries water through a large drainage basin in Peninsular India. D is incorrect because the Krishna is an Indian river, not a foreign river. A useful comparison is that most large east-flowing Peninsular rivers reach the Bay of Bengal, while Narmada and Tapi are notable west-flowing examples. Memory cue: “Krishna, Godavari and Kaveri = Peninsular rivers.”