What is Water Cycle?

• It is the flow/movement

• and storage of water

• in and between the atmosphere, the lithosphere, the hydrosphere & the biosphere

• It also involves the changes in the state of water - in gaseous, solid & liquid state

Water Cycle

OCEANLAND

ATMOSPHERE

Water evaporates from land & ocean

Evapo-transpiration

OCEANLAND

Water condenses to form cloud

Evapo-transpiration

OCEANLAND

Condensation

Water droplets fall as rain/snow/hail

Evapo-transpiration

OCEANLAND

Condensation

Precipitation on oceanPrecipitation on land

Rain water infiltrates into the soil

Evapo-transpiration

OCEANLAND

Condensation

Precipitation on oceanPrecipitation on land

Infiltration

Water accumulates as surface runoff

Evapo-transpiration

OCEANLAND

Condensation

Precipitation on oceanPrecipitation on land

Surface runoff

Various processes/flows in the water cycle

C

OCEANLAND

A

B D

EF

Basin Hydrological Cycle (Land Phase)

C

OCEANLAND

Atmosphere

D

EFG

H I

Basin Hydrological Cycle (Land Phase)

1. Flow - evaporation,precipitation, stemflow, infiltration, throughflow, surface runoff, _________ ….

2. Storage - interception, soil water, ground water, channel, _________…..

Human Impacts on water cycle

1. Deforestation - removal of trees

2. Agriculture - intensive cultivation

3. Urbanization - widespread development of built-up areas

River Basin & Fluvial Processes

• A river forms when rain falls on the land which forms rills

• rills flow downslope, more rainfall, in the form of runoff, joins them, and the rills grow larger, the rills are large enough to be called streams

River Basin

• A main stream and its tributaries river forms a network of streams, called a drainage network/system

• This network occupies and drains a definite area of land. This area is called a drainage basin

River Basin

• The boundary of the basin forms the watershed of the basin. It follows the crests of the ridges & hills.

Tributary

Watershed Main Stream

River

Mouth

A drainage basin

River Basin

• River basins, like all other systems, have inputs, processes & outputs.

• It is an open system

Related websites:Related websites:

http://www.gewex.com

http://www.iwr.msu.edu/edmodule/water/cycle.htm

http://www.ghcc.msfc.nasa.gov/