What is a Drainage Basin?

What is a Drainage Basin?

Definition:

• A drainage basin, also known as a river basin or watershed, is an area of land where all the surface water (rainfall, snowmelt, etc.) drains into a common river, stream, lake, or other water body.

Components of a Drainage Basin:

• Main River or Stream: The primary river or stream that collects and carries the water within the drainage basin.
• Tributaries: Smaller rivers, streams, or creeks that flow into the main river or stream.
• Divide or Watershed Boundary: The highland or ridge that separates one drainage basin from another. It determines which way the water flows.

Inputs to the Drainage Basin System:

• Precipitation: Rainfall and snowmelt are the primary sources of water that enter a drainage basin.
• Groundwater: Water from underground aquifers can seep into the drainage basin.

Outputs from the Drainage Basin System:

• River Flow: The primary output is the flow of water in the main river or stream, which eventually leads to the ocean or another body of water.
• Evaporation: Some water is lost to the atmosphere through evaporation from rivers, lakes, and soil.
• Transpiration: Plants release water vapour through a process called transpiration.
• Groundwater Flow: Water may also flow underground as groundwater to replenish aquifers or discharge into other water bodies.

Uses of Drainage Basins:

• Drainage basins are essential for supplying freshwater for drinking, agriculture, and industrial use. They also play a crucial role in managing and conserving water resources.

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Geography

What is a Drainage Basin?

Summary

• A drainage basin is an area of land where all surface water drains into a common river, stream, or water body.
• It consists of a main river, tributaries, and a watershed boundary.
• Inputs include precipitation and groundwater, while outputs include river flow, evaporation, transpiration, and groundwater flow.
• Drainage basins are vital for water supply and resource management.