DRAINAGE SYSTEM OF INDIA

DRAINAGE SYSTEM OF INDIA

WHAT IS DRAINAGE?

• The flow of water through a well-defined channels.

WHAT IS DRAINAGE SYSTEM?

• The network of such channels is called a ‘drainage system’.
• The drainage system of an area is the outcome of :

• Geological time period
•  nature and structure of rocks
•  Slope
•  Topography
•  Amount of water flowing
• Periodicity of flow.

WHAT IS DRAINAGE BASIN?

• The area drained by a single river and its tributaries.

WHAT IS WATER DIVIDE?

•  An elevated area that separates two drainage basins.
•  The largest drainage basin in India is the river Ganga basin.

WHAT IS DRAINAGE PATTERN?

• The system of surface water flow mainly through the forms of rivers and basins.

WHAT ARE DIFFERENT DRAINAGE PATTERNS?

• Dendritic 

• This system resembles the branches of a tree.
• For example, the rivers of the northern plains.

• Radial

• This system occurs when the rivers originate from a hill and flow in all directions.
•  For example, rivers originating from the Amarkantak range.

• Trellis

• This system occurs when the primary tributaries of a river flow parallel to each other and secondary tributaries join them at right angles.

• Centripetal
• This system occurs when the rivers discharge their waters in all directions.
   

DRAINAGE SYSTEMS BASED ON ORIENTATION TO THE SEA

1. The Bay of Bengal drainage
2. Arabian sea drainage

The Bay of Bengal drainage

• Rivers that drain into Bay of Bengal
• East flowing rivers
• It covers almost 77 % of the drainage area of the country
• The Ganga, the Brahmaputra, the Mahanadi, the Godavari, the Krishna, the Cauvery etc.

Arabian sea drainage

• Rivers that drain into Arabian sea
• West flowing rivers.
• It covers almost 23 per cent of the drainage area of the country
• The Indus, the Narmada, the Tapi, the Sabarmati, the Mahi etc.