By Hector Marin

Jesus Lopez

Sammy Barajas

Israel Lara

HYDROLOGIC CYCLE

• Precipitation is the primary mechanism for transporting water from the atmosphere to the surface of the earth

• There are several forms of precipitation like hail, snow, sleet, and rain

• Amounts of precipitation also vary from year to year, like in 1988, an intense drought happened the Midwestern United States, messing up agriculture because there was not enough rain to take care of their crops

• In evaporation water is transferred from the surface to the atmosphere, the process by which water changes from a liquid to a gas

• Approximately 80% of all evaporation is from the oceans, with the remaining 20% coming from inland water and vegetation

EVAPORATION PRECIPITATION

• Condensation is the change of water from its gaseous form (water vapor) into liquid

• Condensation generally occurs in the atmosphere when warm air rises, cools and looses its capacity to hold water vapor water.

• Transpiration is one of the main processes in the water cycle

• Transpiration is the evaporation of water into the atmosphere from the leaves and stems of plants

• Transpiration accounts for approximately 10% of all evaporating water

• Plants absorb soil water through their roots and this water can originate from deep in the soil

• Plants pump the water up from the soil to deliver nutrients to their leaves

TRANSPIRATION CONDENSATION

• Runoff is the movement of land water to the oceans, mainly in the form of rivers, lake

• Runoff consists of precipitation that neither evaporates, transpires nor penetrates the surface to become ground waters, and streams

• Transport is the movement of water through the atmosphere, specifically from over the oceans to over land

• Some of the earth's moisture transport is visible as clouds, which themselves consist of ice crystals and tiny water droplets

TRANSPORT RUNOFF

THE MAIN ISSUE WITHIN THE WATER CYCLE • Humans can and do interfere with the water cycle. These are some of the actions that can

have an impact on the water cycle – the green house effect, irrigation, and deforestation , etc..

• Irrigation is the artificial watering of land that does not get enough water through rainfall.

• Deforestation is the removal of trees ; which can cause problems with the water cycle

• Thirdly, the green house effect is a natural phenomenon of Earth’s atmosphere trapping a range of gases, which in turn capture infrared radiation to keep our Earth at a moderate temperature range.

HOW DO HUMAN AFFECT OTHER PROCESSES OF THE WATER CYCLE.

• The green house effect or raising of the Earth’s temperature may mean that there is an increase of evaporation; therefore more water gets condensed and the process of precipitation is affected.

• Deforestation decreases the amount transpiration from trees which in turn effect the level of evaporation in the atmosphere ,as well as the process of precipitation.

• The problem with irrigation is that it can cause run-off where ever it is used. Excess run-off can lead to flooding, which occurs when there is too much precipitation

HOW DO THESE PROBLEMS AFFECT THE ENVIRONMENT?• The problem with irrigation is that it removes water from its natural source and often

causes leaching and run-off where it is used. Thus , excess run-off can cause a major flooding like the Northern Plains Flooding of May ,1997 which caused towns along the Red River like Grand Forks, North Dakota to shut down due to flooding that completely paralyzed the city.

• Since the green house effect causes our Earth to stay at a constant temperature, polar ice caps can melt and affect the climate of the Earth. This can severely damage ecosystems and organisms.

• Deforestation in one area can therefore affect the weather in another area because if trees are cut down, there is less water to be evaporated into the atmosphere and subsequently less rain. As a result, these areas can be prone to droughts and flooding, impacting plants , animals, and humans living near deforested areas.

.

REFERENCES• http://www.enviroliteracy.org/favicon.ico

• 2. The effects of changes in the world hydrological cycle on availability of water resources

• Nature current issue RSS feed

• Man’s impact on the hydrological cycle « David Krohn

• Graphics by: Dan Bramer