NOTES Geography Chapter 3 (Class 9, CBSE, NCERT): "Drainage".

 

summary for Geography Chapter 3 (Class 9, CBSE, NCERT): "Drainage".

Chapter 3: Drainage

The term drainage refers to the system of rivers and their tributaries that drain the surface water from a specific region. Drainage plays a critical role in shaping the landscape and supporting the water cycle.

India has a variety of drainage systems, which include rivers, lakes, and wetlands. The drainage system in India can be classified into two major types: the Himalayan Rivers and the Peninsular Rivers.

1. The Concept of Drainage

  • Drainage System: It refers to the network of rivers and their tributaries that drain a specific area.
  • Importance of Drainage: Rivers provide water for irrigation, drinking, and industrial use. They also help in transportation and support agriculture.

India’s drainage system is influenced by its diverse geography and climate. The rivers can be broadly divided into two categories based on their origins: Himalayan Rivers and Peninsular Rivers.

2. The Himalayan Rivers

The Himalayan rivers are perennial, meaning they flow throughout the year. They are fed by glaciers, rainfall, and snowmelt from the Himalayan Mountains. These rivers are generally long and have large basins.

Major Himalayan Rivers:

  1. The Indus River:

    • Origin: The Tibetan Plateau near Tibet.
    • Course: It flows through Pakistan and a part of India in Jammu & Kashmir before draining into the Arabian Sea.
    • Tributaries: Major tributaries include Jhelum, Chenab, Ravi, Beas, and Sutlej.
    • Importance: The Indus is important for irrigation and is a major river in Pakistan.

  2. The Ganga River:

    • Origin: The Gangotri Glacier in the Uttarkashi district of Uttarakhand.
    • Course: It flows through Uttarakhand, Uttar Pradesh, Bihar, West Bengal, and finally empties into the Bay of Bengal.
    • Tributaries: Major tributaries of the Ganga include the Yamuna, Ganges, Ghaghara, Kosi, and Saraswati.
    • Importance: The Ganga is one of the most important and sacred rivers in India, supporting millions of people in the Ganga Basin. It is heavily used for irrigation, transportation, and religious rituals.

  3. The Brahmaputra River:

    • Origin: The Tibetan Plateau (China) as the Yarlung Tsangpo river.
    • Course: It enters India through Arunachal Pradesh, flows through Assam, and finally empties into the Bay of Bengal.
    • Tributaries: Major tributaries include the Subansiri, Dibang, and Lohit.
    • Importance: The Brahmaputra is a major river for both agriculture and transportation, particularly in the Northeastern states.

3. The Peninsular Rivers

Unlike the Himalayan rivers, Peninsular rivers are mainly seasonal and flow only during the monsoon period. These rivers originate from the Peninsular Plateau and flow towards the east or west. The major rivers of India are relatively shorter compared to the Himalayan rivers.

Major Peninsular Rivers:

  1. The Godavari River:

    • Origin: The Western Ghats near Nasik in Maharashtra.
    • Course: It flows eastward and drains into the Bay of Bengal.
    • Tributaries: Major tributaries include the Penganga, Pranhita, and Indravati.
    • Importance: The Godavari is the second-longest river in India and is crucial for irrigation in the Deccan Plateau.

  2. The Narmada River:

    • Origin: The Amarkantak Plateau in Madhya Pradesh.
    • Course: It flows westward and drains into the Arabian Sea.
    • Tributaries: Major tributaries include the Tawa, Hiran, and Kolar rivers.
    • Importance: The Narmada river is unique as it flows westward, unlike most other rivers in India, which flow eastward.

  3. The Tapi (Tapti) River:

    • Origin: The Satpura Range in Madhya Pradesh.
    • Course: It flows westward through Maharashtra and Gujarat and drains into the Arabian Sea.
    • Tributaries: Major tributaries include the Purna, Girna, and Penganga rivers.

  4. The Mahanadi River:

    • Origin: The Chhattisgarh Plateau in Madhya Pradesh.
    • Course: It flows eastward and empties into the Bay of Bengal.
    • Tributaries: Major tributaries include the Ib, Seonath, and Mand rivers.
    • Importance: The Mahanadi supports extensive irrigation and is crucial for fishing in the delta region.

4. Rivers of the Coastal Plains

There are also some important rivers that flow into the coastal plains and are comparatively short:

  • The Sabarmati River (flows into the Arabian Sea).
  • The Krishna River (flows into the Bay of Bengal).
  • The Cauvery River (flows into the Bay of Bengal).
  • These rivers support a lot of agriculture in their regions and are used for irrigation.

5. The Role of Lakes and Wetlands

Apart from rivers, lakes and wetlands also form important components of the drainage system in India.

  • Lakes like the Vembanad Lake in Kerala and the Wular Lake in Jammu & Kashmir play an important role in maintaining the water cycle and supporting local ecosystems.
  • Wetlands like the Sundarbans (located in the delta region of West Bengal) are crucial for biodiversity and flood control.

6. Drainage Systems of India: Features & Importance

  • East Flowing Rivers: Most of the Peninsular rivers flow eastward towards the Bay of Bengal, providing fertile plains and irrigation for agriculture (like Godavari, Krishna, Mahanadi).

  • West Flowing Rivers: Some Peninsular rivers like the Narmada and Tapi flow westward and drain into the Arabian Sea.

  • Importance of Rivers: Rivers in India are important for agriculture, transportation, irrigation, and fishing. They also provide water for daily use and contribute to the economic development of the country.

Key Points to Remember

  1. Himalayan Rivers: Long, perennial rivers like the Ganga, Indus, and Brahmaputra that originate in the Himalayas and flow throughout the year.
  2. Peninsular Rivers: Seasonal rivers like the Godavari, Narmada, and Krishna that originate from the Peninsular Plateau and mostly flow towards the east or west.
  3. Drainage System: The system of rivers, lakes, and wetlands that drain the land, helping maintain the water cycle and supporting agricultural, domestic, and industrial activities.
  4. Drainage Basins: River basins are the areas drained by a river and its tributaries. India has several drainage basins, including those of the Ganga, Indus, and Brahmaputra.
  5. Importance: Rivers are essential for irrigation, drinking water, transportation, and sustaining ecosystems.

Comments

Post a Comment

Popular posts from this blog

NOTES Chapter 15: Our Environment Class 10 Science – CBSE NCERT

  Chapter 15: Our Environment Class 10 Science – CBSE NCERT Chapter 15 focuses on the various components that make up our environment, including ecosystems , biotic and abiotic factors , and food chains and webs . It highlights the balance of nature , biodiversity , and environmental issues like pollution, deforestation, and the need for sustainable development. The chapter also explains the impact of human activities on the environment and emphasizes the importance of conserving natural resources for future generations. 1. The Environment and Its Components The environment is the surrounding in which organisms live. It includes both living and non-living things and can be broadly classified into two categories: 1.1 Biotic Components : These are the living organisms in the environment. They include: Plants (producers), Animals (consumers), Microorganisms (decomposers). 1.2 Abiotic Components : These are the non-living factors that affect the living organisms in th...
Read more

NOTES Chapter 12: "Sound" from Class 9 Science CBSE NCERT:

  summary of Chapter 12: "Sound" from Class 9 Science CBSE NCERT : 1. What is Sound? Sound is a form of energy that is produced by the vibration of objects and propagates through a medium (solid, liquid, or gas) in the form of waves. Sound travels in waves and can be heard when it reaches our ears . How is sound produced? Sound is produced when an object vibrates. These vibrations cause the particles of the medium to move, creating compressions and rarefactions (regions of high and low pressure) that travel through the medium. 2. Propagation of Sound Sound needs a medium (like air, water, or solid objects) to travel. It cannot travel in a vacuum. How sound waves travel : Sound waves are longitudinal waves (particles of the medium move in the same direction as the wave). When an object vibrates, it creates a series of compressions (regions where particles are close together) and rarefactions (regions where particles are spread apart) in the surrounding medium. These co...
Read more

Moments Chapter 3 of CBSE Class 9, titled "Iswaran the Storyteller" by R.K. Narayan:

  summary of Chapter 3 of Moments for CBSE Class 9, titled "Iswaran the Storyteller" by R.K. Narayan : Summary: In this chapter, the story is centered around Iswaran , a cook who works for the narrator, and his fascinating way of telling stories. Iswaran's storytelling skills and his adventurous nature provide both entertainment and a sense of mystery to the narrator, who works in a small town. The narrator begins by describing Iswaran as an enthusiastic and talented cook who makes delicious food and is always happy to serve. Iswaran is very devoted to his job and never seems to get tired, no matter how much work is piled up. He is also well known for his remarkable storytelling abilities. He often entertains the narrator with thrilling stories, which he describes in vivid detail. The Background of Iswaran’s Life: Iswaran is originally from a village, and he later moves to the town where he works for the narrator. He is described as a "man of strong character...
Read more