1. What is a drainage system?
Answer:
- A drainage system refers to the network of rivers and their tributaries which drain a particular area.
- It includes main rivers, tributaries, distributaries, and basins.
- It is influenced by relief, slope, climate, rock structure, and human activity.
2. Differentiate between a drainage basin and a watershed.
Answer:
- A drainage basin is the area drained by a single river and its tributaries.
- A watershed is the boundary line separating two drainage basins.
- A basin is larger; a watershed is a higher ridge or divide.
3. What are the two main drainage systems of India?
Answer:
- Himalayan Rivers – Perennial rivers originating from the Himalayas, fed by snow and rainfall.
- Peninsular Rivers – Mostly seasonal rivers originating from plateaus, dependent on monsoon rains.
4. Name three major Himalayan rivers.
Answer:
- Indus
- Ganga
- Brahmaputra
5. Write a short note on the Ganga River system.
Answer:
- The Ganga originates from Gangotri Glacier as Bhagirathi in Uttarakhand.
- It merges with Alaknanda at Devprayag to form the Ganga.
- Major tributaries:
- Right bank: Yamuna, Son
- Left bank: Ghaghara, Gandak, Kosi
- Flows through Uttar Pradesh, Bihar, West Bengal, and drains into the Bay of Bengal.
- Forms the Sundarbans Delta, the world’s largest delta.
6. Explain the main features of the Brahmaputra River.
Answer:
- Originates in Tibet as Tsangpo, enters India as Dihang.
- Called Brahmaputra in Assam.
- Known for high silt load, floods, and wide channels.
- Joins the Ganga in Bangladesh to form the Meghna River.
7. What are the major rivers of Peninsular India?
Answer:
- Narmada
- Tapi
- Godavari
- Krishna
- Mahanadi
- Kaveri
8. Why are Himalayan rivers perennial while Peninsular rivers are seasonal?
Answer:
- Himalayan rivers are snow-fed and have glacial origins, so they flow all year.
- Peninsular rivers are rain-fed, thus they flow mainly during the monsoon.
9. Describe the Narmada River.
Answer:
- Origin: Amarkantak Plateau, Madhya Pradesh
- Flows westward into the Arabian Sea
- Creates a rift valley between Satpura and Vindhya ranges
- Forms gorges and waterfalls, e.g., Marble Rocks at Bhedaghat
- Forms an estuary, not a delta
10. What is the importance of rivers in the economy of India?
Answer:
- Provide irrigation, drinking water, and electricity (hydropower)
- Enable inland navigation and transport
- Support agriculture, industries, and fisheries
- Have religious and cultural importance
11. How is the Ganga river polluted?
Answer:
- Industrial discharge, sewage, plastic waste, and religious offerings
- Leads to loss of aquatic life, health issues, and ecosystem damage
- Controlled through Namami Gange Programme and River Action Plans
12. Write a short note on river pollution and conservation.
Answer:
- Rivers in India are becoming highly polluted due to untreated waste
- Steps for conservation:
- Sewage treatment plants
- Strict industrial regulations
- Public awareness campaigns
- Programs like Namami Gange, NRCP (National River Conservation Plan)
13. What is the difference between a delta and an estuary?
Answer:
- A delta is a triangular landform formed at the mouth of a river due to deposition of sediments (e.g., Ganga).
- An estuary is a funnel-shaped river mouth where the river meets the sea and tides influence water (e.g., Narmada).
14. Name the west-flowing rivers of India.
Answer:
- Narmada
- Tapi
- Mahi
- Sabarmati
15. Explain the drainage pattern and its types.
Answer:
- Drainage pattern: Geometric pattern formed by rivers and their tributaries.
- Types:
- Dendritic – tree-like, common in plains (e.g., Ganga)
- Radial – rivers flow outward from a central point (e.g., Amarkantak Plateau)
- Trellis – rectangular pattern due to hard and soft rocks
- Centripetal – rivers flow into a central basin (e.g., inland basins of Rajasthan)
16. Which is the largest river basin in India?
Answer:
- The Ganga Basin is the largest river basin in India.
17. Why is river interlinking proposed in India?
Answer:
- To manage floods in some areas and drought in others
- Ensure equitable water distribution
- Support irrigation, drinking water, and hydropower
- Example: Ken-Betwa Project
18. What are the disadvantages of river interlinking?
Answer:
- Displacement of people
- Deforestation and ecological damage
- Very expensive projects
- May affect river flow patterns
19. Mention two major saltwater lakes in India.
Answer:
- Sambhar Lake – Rajasthan
- Chilika Lake – Odisha
20. What is the significance of the Sundarbans delta?
Answer:
- Formed by Ganga and Brahmaputra
- World’s largest delta
- Known for mangrove forests and Royal Bengal Tiger
- UNESCO World Heritage Site