RBSE Class 9 Social Science Notes Geography Chapter 3 Drainage

These comprehensive RBSE Class 9 Social Science Notes Geography Chapter 3 Drainage will give a brief overview of all the concepts.

RBSE Class 9 Social Science Notes Geography Chapter 3 Drainage

→ Drainage:
Drainage means flow. The term drainage describes the river system of an area. 

→ River System:
A river along with its tributaries is known as river system.

→ Drainage Basin:
The area drained by a single river system is called a drainage basin.

→ Drainage Systems in India:
The drainage systems of India are mainly controlled by the broad relief features of the subcontinent. Accordingly, the Indian rivers are divided into two major groups:

1. The Himalayan rivers
2. The Peninsular rivers.

Apart from originating from the two major physiographic regions of India, the Himalayan and the Peninsular rivers are different from each other in many ways.

→ The Himalayan Rivers:
Most of the Himalayan rivers have water throughout the year. The main rivers originating from the Himalayas are the Indus, the Ganga and the Brahmaputra. The description of these are as follows:

• The Indus River System: The river Indus rises in Tibet, near Lake Mansarowar. This river system includes the Indus and its tributaries the Satluj, the Beas, the Ravi, the Chenab, Jhelum etc. These rivers join together to enter the Indus near Mithankot in Pakistan.The Indus river falls in the Arabian Sea.
• The Ganga River System: The headwaters of the Ganga, called the ‘Bhagirathi’ is fed by the Gangotri Glacier. Important tributaries of Ganga are Yamuna, Ghaghara, Gandak, Kosi etc. and the main tributaries, which come from the peninsular uplands, are the Chambal, the Betwa, the Son, etc. The main tributary of Ganga- the Yamuna river originates from Yamunotri. Before falling into the Bay of Bengal, the Ganga and the Brahmaputra river together form the Sunderban Delta, which is considered to be the largest delta in the world.
• The Brahmaputra River System: The Brahmaputra rises in Tibet east of Mansarowar lake very close to the sources of the Indus and the Satluj. It’s tributaries are the Dibang, the Lohit, the Kenula, the Teesta, the Jhanji, the Kulsi, the Manas, the Kapila etc.

→ The Peninsular Rivers:
Most of the rivers of Peninsular India are seasonal. During the dry season, the water of big rivers also starts flowing down into small streams. Most of the rivers in this region originate from the Western Ghats and flow towards the Bay of Bengal.

The major drainage basins of this region are:

• The Narmada Basin: It falls in the Arabian Sea.
• The Tapi Basin: It falls in the Arabian Sea.
• The Godavari Basin: It falls in the Bay of Bengal.
• The Mahanadi Basin: It falls in the Bay of Bengal.
• The Krishna Basin: It falls in the Bay of Bengal.
• The Kaveri Basin: It falls in the Bay of Bengal.

→ Lakes:
Where the water accumulates in the trough parts of the surface of the earth, it is called a lake. India has many lakes. Some are salt water lakes and the other are freshwater. Some lakes are made naturally and some are man-made.

→ Role of Rivers in the Economy:
Rivers have been of fundamental importance in the economy. Using rivers for irrigation, navigation, hydro-power generation, is of special significance especially in an agricultural country like India.

→ River Pollution:
At present, the rivers are being polluted due to the heavy load of untreated sewage and industrial effluents which are emptied into the rivers. We should keep the rivers clean.

→ National River Conservation Plan (NRCP):
The National River Conservation Plan has been implemented to remove pollution of rivers and keep them clean.