Ground Water

Only available on StudyMode
  • Download(s) : 18
  • Published : January 3, 2013
Open Document
Text Preview
GROUND WATER

THE WATER/HYDROLOGIC CYCLE
* Composed of evaporation from the oceans
* Movements of moist air inland
* Condensation and precipitation
* Run-off on the surface or sub-surface back to the ocean * Plus additional minor cycles
* Involves the exchange of water with the atmosphere, the earth, and the different water forms * Done when clouds gain water vapor from the various water forms * Evaporation – process where water turns into steam or gas when the temperature is hot * Condensation – water vapor goes into the air and into the clouds where it turns into water again * Water precipitation follows; the cycle will go back to the beginning and repeat its process SUBSURFACE WATER

- All of the water occupying pore spaces below the ground surface * Vadose zone or zone of aeration –pore spaces are filled partly with water, partly with air * Water table – where the saturated zone is not at all confined by overlying impermeable rocks * Zone of saturation – zone of rock or soil that is water saturated, in which water fills all the accessible pore spaces * True ground water – water in the zone of saturation

GROUND WATER
* Found at most a few kilometers from the crust
* Flows laterally through permeable soil and rock,
* From higher elevations to lower,
* From areas of abundant infiltration to drier ones,
* Or from places of little ground water use towards places of heavy use * Largest reservoir of unfrozen fresh water in the hydrologic cycle Parts of the Hydrosphere | % of total water | % of fresh water | % of unfrozen freshwater | Oceans | 97.54 | - | - |

Ice glaciers | 1.81 | 73.9 | - |
Ground Water | 0.63 | 25.7 | 98.4 |
Streams and lakes: | | | |
fresh | 0.009 | 0.36 | 1.4 |
salt | 0.007 | - | - |
Water vapor (atmosphere) | 0.001 | 0.04 | 0.2 |
Total | 99.997 | 100.00 | 100.00 |
3 SOURCES OF GROUND WATER
a) Meteoric water – precipitation from the atmosphere as rain or snow; seeps down into the spaces within rocks b) Connate water – trapped in microscopic spaces when sedimentary rocks are formed in the beds, seas, or lakes; usually salty c) Magnetic water – chemically bound up in mineral and released by heating in volcanic processes WELLS

* Hole that is dug or drilled deep enough into the ground to reach the water table * Formed when water flows into and fills up the hole
* Artesian well - type of well where water is obtained from an aquifer in a porous rock layer, usually consisting of sandstone or loose sand and gravel; Often drilled several thousand feet deep *It should not be assumed that all deep wells are artesian.

SPRING
* occurs whenever ground water comes naturally to the surface * some springs are discharged where the water table intersects the land surface but they may occur where water flows out from a cavern or along fractures, faults, or rock contacts that comes to the surface * can occur on a hillside where the table water intersects the land surface. These types of springs do not flow continuously since the water table may drop to low during dry periods MINERAL SPRINGS

* spring water containing dissolved minerals
* are not usable for drinking
SULFUR SPRINGS
* contain dissolved hydrogen sulfide gas which gives it an offensive odor HOT SPRINGS
* formed when water gets heated by nearby magma before coming out of the earth * contain many dissolved minerals because hot water dissolves minerals more readily than cold water does
* hot springs are abundant around the vicinity of Mt. Makiling in Calamba and Los Baños and Mayon Volcano in Albay
* temperature ranges from 6 to 9 degrees Celsius
* boiling point varies depending on the altitude of the spring location GEYSER
Geyser is a hot spring that emits steam and hot water periodically. The interval between eruptions indicates the times it takes the ground water...
tracking img