Water doesnt leave the planet - it is continuoulsy cycled between the ocean and the atmosphere.
Forms of precipitation
A rivers drainage basin is the area surrounding the river where the rain is failling on the land flows into the river.
The boundary of the drainage basin are called watersheds-water falling beyond the watershed enters a different drainage basin.
Drainage basins are open systems with inputs and outputs.
Water enters the system though precipitaion - leaves via evaporation, transpiration and river discharge.
Drainage basin terminology
- Precipiation- the way moisture comes out of the atmosphere, eg, rain, hail, snow, fog.
- Interception - when some of the precipitaion lands on vegetation or other structures such as buildings, before it reaches the soil. Interception is only TEMPORARY as the water is evaporated.
- Vegetation storage - water that has been taken up by the plants.
- Surface storage - water in puddles, lakes and ponds.
- Groundwater storage- water stored in the ground, either in soil or rocks.
- The water table - the top surface of the zone of saturation.
- Channel storage - water held in a river or channel.