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id: "67b7d7ac444073b65d6df54e"
title: "Drainage"
board: "CBSE"
curriculum: "CBSE"
class: "Class 9"
subject: "Social Science"
book: "Contemporary India"
chapter: "Drainage"
chapter_slug: "drainage"
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# Drainage
The drainage of an area refers to its river system. Notably, small streams from various directions converge to form the main river, which flows into vast water bodies like lakes, seas, or oceans. The entire area supplied by a solitary river system is termed a drainage basin, typically delineated by natural elevations like mountains, referred to as water divides.

---

## Knowledge Snapshot

| Field | Details |
| :--- | :--- |
| Class | Class 9 |
| Subject | Social Science |
| Book | Contemporary India |
| Chapter | Drainage |
| Pages | 17-25 |

---

## Chapter Summary

### Short Summary
The chapter covers the drainage systems in India, highlighting the division into Himalayan and Peninsular rivers, their characteristics, tributaries, and significant ecological features.

### Detailed Summary
This chapter discusses drainage in India, categorizing the river systems into Himalayan and Peninsular rivers. Himalayan rivers are predominantly perennial, receiving water year-round, whereas Peninsular rivers mainly depend on rainfall and exhibit shorter courses. The major Himalayan rivers, such as the Indus, Ganga, and Brahmaputra, have significant tributaries and ecological impacts. The Indus originates in Tibet, flows through India, and meets the Arabian Sea. The Ganga flows from the Himalayas, nourished by numerous tributaries and bifurcating into the Ganges delta. The Brahmaputra, flowing from Tibet and known for its silt-rich waters, faces flooding during monsoon. In contrast, Peninsular rivers, like the Mahanadi and Godavari, predominantly drain into the Bay of Bengal, forming deltas. The Narmada and Tapi, however, flow westward towards the Arabian Sea.

---

## Topic-Wise Explanation

### DRAINAGE
The concept of drainage pertains to the network of rivers and their tributaries that transport water to larger water bodies and the specific area they cover.

### DRAINAGE SYSTEMS IN INDIA
India's drainage systems are categorized into Himalayan and Peninsular rivers, influenced by the distinct geographical features of the subcontinent.

### LAKES
Omitted in the supplied context.

### ROLE OF RIVERS IN THE ECONOMY
Rivers facilitate agricultural irrigation and support biodiversity, impacting economic activities by providing water supply and fertile lands.

### RIVER POLLUTION
Omitted in the supplied context.

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## Core Ideas

| Idea | Explanation |
| :--- | :--- |
| Himalayan Rivers | Characterized by their perennial nature and significant erosive power, forming features like gorges and deltas. |
| Peninsular Rivers | Mostly seasonal, shorter and dependent on rainfall, contributing to agricultural irrigation and regional geography. |

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## Important Points for Revision

* The drainage area of a river system is known as a drainage basin.
* Himalayan rivers are generally perennial due to melting snow and rainfall.
* The Indus River system includes the longest river in India, flowing into the Arabian Sea.
* The Ganga is significant for its tributaries that flood northern plains annually.
* The Brahmaputra is known for its braided channels and substantial silt deposits.
* Peninsular rivers primarily drain towards the Bay of Bengal.
* The Western Ghats act as a major water divide in Peninsular India.
* Major Peninsular rivers include the Mahanadi, Godavari, and Krishna.
* The Narmada and Tapi are unique for flowing towards the west, into the Arabian Sea.

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## Practice Questions

### Short Answer Questions
1. What is the definition of a drainage basin?
2. Name two major Himalayan rivers and their significance.
3. What is the primary characteristic that differentiates Himalayan rivers from Peninsular rivers?
4. Describe the course of the Indus River.
5. What role do tributaries play in a river system?

### Long Answer Questions
1. Explain the features of Himalayan rivers and their impact on the landscape.
2. Discuss the drainage systems of Peninsular India and their economic importance.
3. Describe the Ganga River system and its major tributaries.

---

## Source Attribution

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| :--- | :--- |
| Source | Edzy |
| Reference Type | examSubjectBookChapter |
| Reference ID | 67b7d7ac444073b65d6df54e |
| Canonical URL | https://www.edzy.ai/cbse-class-9-social-science-contemporary-india-drainage |
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