Catchment area
Topic: Drainage System of India: Rivers, Basins and Patterns · NCERT: Class 11, Ch 3 "Drainage System"; Class 11, Ch 6 "Natural Hazards and Disasters: Causes, Consequences and Management"
Meaning
A catchment area is all the land from which a river collects its water. Rain or melted snow that falls anywhere in this area runs downhill and ends up in that river. The size of the catchment, and how much rain it gets, decide how much water the river carries and how badly it can flood. Words change with scale. The catchment of a large river is called a river basin. The catchment of small streams and rills (tiny channels) is usually called a watershed.
Example
The Kaveri's catchment starts in the Brahmagiri hills of Kodagu, Karnataka, and spreads across Karnataka, Tamil Nadu and a little of Kerala. Its upper part gets the southwest (summer) monsoon and its lower part gets the northeast (winter) monsoon. So the Kaveri's flow changes less through the year than that of any other Peninsular river.
Don't confuse with
- Command area: the land that a dam or canal supplies with water, usually downstream. A catchment is the land that supplies water to the river.
Related concepts
- Drainage basin
- Watershed
- Arabian Sea and Bay of Bengal drainage
- Classification of river basins by size