DRAINAGE - Q&A
EXERCISE
1. Choose the right answer from the four alternatives given below.
(i) In which of the following states is the Wular lake located?
(a) Rajasthan
(b) Punjab
(c) Uttar Pradesh
(d) Jammu and Kashmir
Answer: (d) Jammu and Kashmir
Explanation: Wular Lake is famous for being one of the largest freshwater lakes in India. It is located in the Bandipora district of Jammu and Kashmir and is formed by tectonic activity.
(ii) The river Narmada has its source at
(a) Satpura
(b) Amarkantak
(c) Brahmagiri
(d) Slopes of the Western Ghats
Answer: (b) Amarkantak
Explanation: The Narmada river originates from the Amarkantak hills in Madhya Pradesh. It flows westwards through a rift valley.
(iii) Which one of the following lakes is a salt water lake?
(a) Sambhar
(b) Wular
(c) Dal
(d) Gobind Sagar
Answer: (a) Sambhar
Explanation: The Sambhar Lake, located in Rajasthan, is a salt water lake. Its water is used for producing salt. Wular, Dal, and Gobind Sagar are freshwater lakes.
(iv) Which one of the following is the longest river of the Peninsular India?
(a) Narmada
(b) Godavari
(c) Krishna
(d) Mahanadi
Answer: (b) Godavari
Explanation: The Godavari is the largest Peninsular river. It is often referred to as the 'Dakshin Ganga' because of its length (about 1500 km) and the area it covers.
(v) Which one amongst the following rivers flows through a rift valley?
(a) Mahanadi
(b) Krishna
(c) Tungabhadra
(d) Tapi
Answer: (d) Tapi
Explanation: The Tapi and the Narmada are the two major rivers in India that flow through a rift valley (a valley formed by the sinking of land between two parallel faults).
2. Answer the following questions briefly.
(i) What is meant by a water divide? Give an example.
Answer: Any elevated area, such as a mountain or an upland, that separates two drainage basins is known as a water divide.
Example: The Ambala is located on the water divide between the Indus and the Ganga river systems.
(ii) Which is the largest river basin in India?
Answer: The Ganga basin is the largest river basin in India.
Explanation: The river Ganga, over 2500 km long, drains a massive area in Northern and Eastern India, making its basin the most extensive in the country.
(iii) Where do the rivers Indus and Ganga have their origin?
Answer:
Indus: Originates in Tibet, near Lake Mansarovar.
Ganga: Originates from the Gangotri Glacier in the Himalayas (as the Bhagirathi).
(iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga?
Answer: The two headstreams of the Ganga are the Bhagirathi and the Alaknanda. They meet at Devaprayag in Uttarakhand to form the Ganga.
(v) Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?
Answer: In Tibet, the river carries a smaller volume of water and less silt because it is a cold and dry area. However, once it enters India, it passes through a region of high rainfall, increasing the water volume and silt content significantly.
(vi) Which two Peninsular rivers flow through trough?
Answer: The Narmada and the Tapi are the two Peninsular rivers that flow through a trough (rift valley).
(vii) State some economic benefits of rivers and lakes.
Answer:
1. Irrigation: They provide water for agriculture, which is the backbone of the Indian economy.
2. Hydro-power: Rivers are harnessed to generate electricity.
3. Navigation: They serve as inland waterways for transport.
4. Fisheries: Lakes and rivers support freshwater fishing industries.
5. Tourism: They attract tourists for boating and recreation.
3. Below are given names of a few lakes of India. Group them under two categories – natural and created by human beings.
(a) Wular
(b) Dal
(c) Nainital
(d) Bhimtal
(e) Gobind Sagar
(f) Loktak
(g) Barapani
(h) Chilika
(i) Sambhar
(j) Rana Pratap Sagar
(k) Nizam Sagar
(l) Pulicat
(m) Nagarjuna Sagar
(n) Hirakud
Answer:
Natural Lakes:
1. Wular
2. Dal
3. Nainital
4. Bhimtal
5. Loktak
6. Barapani
7. Chilika
8. Sambhar
9. Pulicat
Human-made (Artificial) Lakes:
1. Gobind Sagar
2. Rana Pratap Sagar
3. Nizam Sagar
4. Nagarjuna Sagar
5. Hirakud
4. Discuss the significant difference between the Himalayan and the Peninsular rivers.
Answer:
Himalayan Rivers:
1. Nature: Perennial (have water throughout the year).
2. Source: Fed by rain and melting snow from the glaciers.
3. Course: Have long courses from source to sea and perform intensive erosional activity.
4. Drainage Pattern: Often form meanders and ox-bow lakes.
5. Examples: Indus, Ganga, Brahmaputra.
Peninsular Rivers:
1. Nature: Seasonal (dependent on rainfall).
2. Source: Fed mainly by rain.
3. Course: Have shorter and shallower courses.
4. Drainage Pattern: Flow through stable, hard rock beds; less meandering.
5. Examples: Godavari, Krishna, Kaveri, Narmada.
5. Compare the east flowing and the west flowing rivers of the Peninsular plateau.
Answer:
East Flowing Rivers:
1. Direction: Flow towards the Bay of Bengal.
2. Delta: Form extensive deltas at their mouths.
3. Tributaries: Have a large number of tributaries.
4. Examples: Mahanadi, Godavari, Krishna, Kaveri.
West Flowing Rivers:
1. Direction: Flow towards the Arabian Sea.
2. Delta: Do not form deltas; they form estuaries.
3. Tributaries: Have fewer and smaller tributaries.
4. Examples: Narmada, Tapi.
6. Why are rivers important for the country's economy?
Answer: Rivers are considered the lifelines of the country's economy because:
1. Agriculture: They provide water for irrigation, essential for a country where agriculture is the major occupation.
2. Energy: They are used for hydro-power generation, a clean source of energy.
3. Transport: They provide cheap inland navigation.
4. Livelihood: They support fisheries and provide water for domestic and industrial use.
5. Civilization: Historically, settlements and cities have developed along river banks due to trade and fertility.
Map Skills
(i) On an outline map of India mark and label the following rivers: Ganga, Satluj, Damodar, Krishna, Narmada, Tapi, Mahanadi, and Brahmaputra.
Answer: (Self-Activity. Description of locations:)
- Ganga: Flows across North India into the Bay of Bengal.
- Satluj: A tributary of the Indus, flowing through Punjab.
- Damodar: Flows through Jharkhand and West Bengal (Sorrow of Bengal).
- Krishna: Flows east across Maharashtra, Karnataka, and Andhra Pradesh.
- Narmada: Flows west in Central India (MP/Gujarat).
- Tapi: Flows west, south of Narmada.
- Mahanadi: Flows east through Odisha.
- Brahmaputra: Flows through the Northeast (Assam).
(ii) On an outline map of India mark and label the following lakes: Chilika, Sambhar, Wular, Pulicat, Kolleru.
Answer: (Self-Activity. Description of locations:)
- Chilika: Coastal lagoon in Odisha.
- Sambhar: Salt lake in Rajasthan.
- Wular: Freshwater lake in Jammu & Kashmir.
- Pulicat: Lagoon on the border of Andhra Pradesh and Tamil Nadu.
- Kolleru: Freshwater lake in Andhra Pradesh (between Krishna and Godavari deltas).
Project/Activity
Solve this crossword puzzle with the help of given clues.
Across
1. Nagarjuna Sagar is a river valley project. Name the river?
2. The longest river of India.
3. The river which originates from a place known as Beas Kund.
4. The river which rises in the Betul district of MP and flows westwards.
5. The river which was known as the "Sorrow" of West Bengal.
6. The river on which the reservoir for Indira Gandhi Canal has been built.
7. The river whose source lies near Rohtang Pass.
8. The longest river of Peninsular India?
Down
9. A tributary of Indus originating from Himachal Pradesh.
10. The river flowing through fault, drains into the Arabian Sea.
11. A river of south India, which receives rainwater both in summer and winter.
12. A river which flows through Ladakh, Gilgit and Pakistan.
13. An important river of the Indian desert.
14. The river which joins Chenab in Pakistan.
15. A river which rises at Yamunotri glacier.
Answer:
Across:
1. KRISHNA
2. GANGA
3. BEAS
4. TAPI
5. DAMODAR
6. SATLUJ
7. RAVI
8. GODAVARI
Down:
9. CHENAB
10. NARMADA
11. KAVERI (Receives rain from both South-West and North-East monsoons)
12. INDUS
13. LUNI
14. JHELUM
15. YAMUNA