Drainage class 9 notes

• The Bhagirathi-Hooghly flows southward through the deltaic plains to the Bay of Bengal.
• The mainstream of the Ganges River flows southward into Bangladesh and is joined by the Brahmaputra River. Further downstream, it is known as the Meghna River.
• The Meghna River flows into the Bay of Bengal and forms the Sundarbans Delta.
• The delta of the Ganges River is an important agricultural region and is home to a diverse range of plant and animal life. It is also an important site for fishing and other economic activities.

The Brahmaputra River System

The Brahmaputra River is a major river in South Asia that flows through China, India, and Bangladesh. Here are some key points about the Brahmaputra River system:

• The Brahmaputra River rises in Tibet, east of Mansarover Lake, and is slightly longer than the Indus River.
• The Brahmaputra River flows through the Himalayas and enters India in Arunachal Pradesh, where it is called the Dihang.
• The Dihang is joined by the Dibang, the Lohit, and many other tributaries to form the Brahmaputra River in Assam.
• The Brahmaputra River then flows through Assam and into Bangladesh, where it is joined by the Ganges River and becomes the Meghna River.
• The Brahmaputra River is an important source of water for irrigation, hydropower, and drinking water for millions of people in the region. It is also an important transportation route and is used for the transportation of goods and people.

The Peninsular Rivers

The Peninsular Rivers are a group of rivers in South India that flow through the Deccan Plateau and other peninsular regions of the country. These rivers are shorter and less permanent than the Himalayan rivers.  Some of the main Peninsular Rivers in India include the Godavari, the Kaveri, the Narmada, the Tapi, and the Krishna.

The Narmada Basin

The Narmada Basin is a region in central India that is drained by the Narmada River and its tributaries. Here is a summary of key points about the Narmada Basin:

• The Narmada River originates in the Amarkantak Plateau in Madhya Pradesh and flows westward through the states of Madhya Pradesh and Gujarat, eventually emptying into the Arabian Sea.
• The Narmada River is the main river in the Narmada Basin and has a total length of about 1,312 kilometers (816 miles).
• The Narmada Basin is known for its natural beauty, with several national parks and wildlife sanctuaries located within its boundaries.

The Tapi Basin

• The Tapi River rises in the Satpura ranges in the Betul district of Madhya Pradesh.
• The Tapi River has a total length of about 724 kilometers (450 miles) and flows through the states of Madhya Pradesh, Gujarat, and Maharashtra.
• The Tapi Basin is an important agricultural and economic region, and the Tapi River is an important source of water for irrigation, hydropower, and drinking water for millions of people in the region.

The Godavari Basin

• The Godavari is the largest Peninsular river in India, with a length of about 1,500 kilometers (930 miles).
• The Godavari River rises from the slopes of the Western Ghats in the Nasik district of Maharashtra and flows through the states of Maharashtra, Madhya Pradesh, Odisha, and Andhra Pradesh.
• The Godavari is joined by a number of tributaries, such as the Purna, the Wardha, the Pranhita, the Manjra, the Wainganga, and the Penganga.
• Owing to its length and the area it covers, the Godavari River is also known as the Dakshin Ganga.

The Mahanadi Basin

• The Mahanadi River is a major river in central and eastern India.
• The Mahanadi River rises in the highlands of Chhattisgarh and has a total length of about 860 kilometers (530 miles).
• The drainage basin of the Mahanadi River is shared by the states of Maharashtra, Chhattisgarh, Jharkhand, and Odisha.

The Krishna Basin

• The Krishna River is a major river in southern India.
• The Krishna River rises from a spring near Mahabaleshwar and has a total length of about 1,400 kilometers (870 miles).
• The Krishna is a fourth longest river in India.

The Kaveri Basin

• The Kaveri River is a major river in southern India that rises in the Brahmagri range of the Western Ghats.
• The Kaveri River has a total length of about 760 kilometers (470 miles) and flows through the states of Karnataka, Kerala, and Tamil Nadu.
• The Kaveri Basin is an important agricultural and economic region.

Lakes

India has many lakes, which vary in size and other characteristics.

1. Most lakes in India are permanent, meaning they contain water throughout the year.
2. Some lakes in India contain water only during the rainy season.
3. Some lakes in India were formed by the action of glaciers and ice sheets.
4. Some lakes in India were formed by wind, river action, or human activities.

Lakes are bodies of water that are surrounded by land and are larger than ponds. Lakes can be found all around the world and can vary in size and depth. Some lakes are permanent, meaning they contain water throughout the year, while others are seasonal and only contain water during certain times of the year.

1. Some lakes in India, such as those in Srinagar and Nainital, are attractive tourist destinations.
2. Lakes in India can be formed in different ways, including by meandering rivers, spits and bars in coastal areas, and by tectonic activity.
3. Some lakes in India are seasonal, such as the Sambhar Lake in Rajasthan.
4. Most of the freshwater lakes in India are in the Himalayan region and are of glacial origin.
5. The Wular lake in Jammu and Kashmir is the largest freshwater lake in India, while other important freshwater lakes include the Dal lake, Bhimtal, Nainital, Loktak, and Barapani.

Importance of Lakes

Lakes are important for many reasons, both for the environment and for human use. Here are a few examples of the importance of lakes:

1. Lakes can help to regulate the flow of a river by storing water and releasing it slowly over time.
2. During heavy rains, lakes can prevent flooding by storing excess water.
3. During dry seasons, lakes can help to maintain an even flow of water in a river.
4. Lakes can be used for developing hydroelectric power.
5. Lakes provide important habitat for a wide variety of plants and animals.
6. Lakes are a source of freshwater for many communities. They can be used for drinking water, irrigation, and other purposes.
7. Lakes are often popular destinations for recreational activities such as swimming, boating, and fishing.
8. Lakes can provide economic benefits to the communities that are located near them. They can attract tourists, support fishing and other industries, and provide a source of income for local businesses.
9. Lakes can help to regulate the local environment by storing water and releasing it slowly over time. This can help to prevent flooding and maintain a stable water supply.

River Pollution

River pollution occurs when harmful substances are introduced into a river, causing damage to the water quality and the ecosystem. These substances can come from a variety of sources, including industrial and agricultural runoff, sewage and waste water, and litter. River pollution can have a range of negative impacts, including harm to human health, destruction of habitats for plants and animals, and reduction of the river’s ability to support economic activities such as fishing and tourism. To prevent river pollution, it is important to implement proper waste management practices and to regulate and monitor the discharge of pollutants into rivers.

Q. What is a drainage basin?

Answer – A drainage basin is an area of land where all the water that falls within it, from rain and snow melt, drains into a common body of water, such as a river, lake, or ocean.

Q. What is the water in a drainage basin called?

Answer –  The water in a drainage basin is called runoff. It is the water that flows through the streams and rivers in the drainage basin and eventually drains into a larger body of water.

Q. What is the boundary of a drainage basin called?

Answer – The boundary of a drainage basin is called the watershed or catchment area. It is the line that separates the drainage basin from adjacent areas.

Q. Where is the ‘Bhagirathi’ river located?

Answer – The Bhagirathi is a river in northern India that is considered to be the source of the Ganges River. It is located in the state of Uttarakhand in the Himalayan Mountains, and it flows through the towns of Gangotri and Uttarkashi before merging with the Alaknanda River at Devprayag to form the Ganges. The Bhagirathi is considered to be a sacred river by Hindus, and it is an important source of water for irrigation and hydroelectric power in northern India.

Q. What is a ‘lagoon’?

Answer – A lagoon is a shallow body of water that is separated from the ocean or a larger body of water by a barrier, such as a coral reef or a sandbar. Lagoons are often found along coastal areas and are commonly formed by the action of waves and tides. They can range in size from small, shallow pools to large bodies of water that cover many square miles. Lagoons can be freshwater or saltwater, and they can support a variety of plant and animal life. Lagoons are important habitats for many species and are also popular tourist destinations due to their beautiful, tropical settings.

Q. What is the longest river in India?

Answer – The Ganges is the longest river in India, with a total length of approximately 2,525 kilometers. It is an important source of water for irrigation and other purposes, and is also considered to be sacred by many Hindus.

Q. Which river is known as the “Sorrow of Bihar”?

Answer – The Kosi River, also known as the “Sorrow of Bihar,” is a tributary of the Ganges that has a history of frequent and devastating floods. The river is known for changing course suddenly, which has caused widespread destruction in the past.

Q. What is the major source of the Narmada River?

Answer – The Narmada River is sourced from the Maikal Hills in Madhya Pradesh. It flows westward through the states of Madhya Pradesh, Maharashtra, and Gujarat before emptying into the Arabian Sea.

Q. Which is the only Indian river that flows from east to west?

Answer – The Narmada River is the only river in India that flows from east to west. It originates in the Maikal Hills in Madhya Pradesh and flows through the states of Madhya Pradesh, Maharashtra, and Gujarat before emptying into the Arabian Sea.