5. Transpiration - a process inwhich plants give off
water vapor into the atmosphere.
EVAPORATION - is when the sunheats up water in rivers or
lakes or the ocean and turns it into vapor or steam. The water vapor
or steam leaves the river, lake or ocean andgoes into the air.
6.
7. Condensation - water vapor in the air gets cold and changes
back intoliquid, forming clouds.
Precipitation - is the process by which water fallsfrom
clouds to the earth asrain, snow, sleet and hail.
8.
9.
10. The continuous cycle of evaporation, condensation and
precipitation gives the earth its water budget.
LocalWaterBudget- waterbudgetofa particular
area.
12. Waterthat falls on theground but doesnot soak into thesoil is known as runoff.
Runoff flowsintostreams. Streams join together tomake rivers,andeventually rivers
flow intothe ocean.
13. StreamErosion - a streamgraduallybecomewiderand deeperas
iterodes itsbanks andbed.
14. They PROTECT againstfloods, FILTERpollutants, RECYCLE potentially-
harmful nutrients, and PROVIDE food and habitat for many types of fish.
These streams also play acritical role inmaintaining the quality and supply
of ourdrinking water,ensure a continualflow of water to surface waters,
and help recharge underground aquifers.
15. A river is a naturalwatercourse
usuallyfreshwater, flowing
towards an ocean, a lake,a sea,
or anotherriver.
25. Effects of UNCLEAN WATER
The pollution of rivers, streams,
and oceans has become a serious
problem around the world. Pollution
can come from many sources,
including factories, farms, sewage,
and illegal dumping.
>>EVAPORATION – 86% evaporates from the ocean, 14% from other sources like lakes, stream soil.
- Evaporation + transpiration = evatranspiration
>> PERCIPITATION – 75% falls in the oceans, 25% flows over the surface as runoff or into groundwater.
all precipitation does not either evaporate or immediately flow from the land to the ocean (creates formation of water – lake)
Factors affecting the local water budget: temperature, presence of vegetation, wind and duration of rainfall.
>> precipitation exceeds the evatranspiration = moist soil and possible flooding
>> evatranspiration exceeds precipitation = soil becomes dry and irrigation may be necessary
90% of the water used by cities and industry is returned to rivers or to the oceans as waste water.
enough fresh water?
> conservation
> desalination – removing salt from the salt water
River system begins to form when local precipitation exceeds evatranspiration.
A river system begins to form when local precipitation exceeds evatranspiration.
