Thursday, April 21, 2011

Water Cycle


WATER CYCLE



WATER CYCLE Hydrologic cycle or H2O cycle :

WATER CYCLE Hydrologic cycle or H2O cycle

WATER CYCLE:

The water cycle, also known as the hydrologic cycle or H2O cycle. Water can change states among liquid, vapor, and ice at various places in the water cycle. WATER CYCLE

Different Processes :

Different Processes Precipitation Condensed water vapor that falls to Earth's surface. Most precipitation occurs as rain, but also includes snow, hail, fog drip, graupel and sleet. About 505 000 km3 (121 000 cubic miles) of water falls as precipitation each year, 398,000 km3 (95,000 cubic miles) of it over the oceans.

Different Processes :

Different Processes Canopy Interception Precipitation that is intercepted by plant foliage and eventually evaporates back into the atmosphere instead of falling.

Different Processes :

Different Processes Snowmelt The runoff produced by melting snow.

Different Processes:

Different Processes Runoff The variety of ways by which water moves across the land. This includes both surface runoff and channel runoff. As it flows, the water may seep into the ground, evaporate into the air, become stored in lakes or reservoirs, or be extracted for agricultural or other human uses.

Different Processes :

Different Processes Infiltration Infiltration is the process by which water on the ground surface enters the soil. Once infiltrated, the water becomes soil moisture or groundwater.

Different Processes :

Different Processes Subsurface Flow The flow of water underground, in the vadose zone and aquifers. Groundwater can return to the surface (for example, as a spring or is pumped) or eventually seep into the oceans. The water returns to the land surface at a lower altitude than in those infiltrated under the force of gravity-induced pressure or gravity. Groundwater tends to move slowly, and is replenished slowly, so they can remain in aquifers for thousands of years.

Different Processes :

Different Processes Evaporation The transformation of water from liquid to gas phases as it moves from the ground or bodies of water into the overlying atmosphere. The source of energy for evaporation is primarily solar radiation. Evaporation often implicitly includes transpiration from plants, though together they are specifically referred to as evapotranspiration .

Different Processes :

Different Processes Sublimation The state change directly from solid water (snow or ice) to water vapor.

Different Processes :

Different Processes Advection The movement of water — in solid, liquid, or vapor states — through the atmosphere. Without advection, water that evaporated over the oceans could not precipitate over land.

Different Processes :

Different Processes Condensation The transformation of water vapor to liquid water droplets in the air, creating clouds and fog.

Different Processes :

Different Processes Transpiration The release of water vapor from plants and soil into the air. Water vapor is a gas that cannot be seen.

Human activities that alter the water cycle include::

Human activities that alter the water cycle include: Agriculture Industry Alteration of the chemical composition of the atmosphere Construction of dams Deforestation and afforestation Removal of groundwater from wells Water abstraction from rivers Urbanization

Slide 15:

For more powerpoint presentations check:- http://sitesforkids-teens-students.blogspot.com/




4 comments:

Monu Awalla said...

hey nice explanation :)

Geeta Singh said...

thanks Monu:) nxt ppt will be on India:P

Defiant said...

Great post :) Defntly an informative one :)

Mohini Puranik said...

Hey! You have worked so hard making this one! PPT is really a challenge to express everything in less words.Please keep doing, great help for kids and students. This way is easy to remember study than simply reading boring chapters.!