Текущая версия на 13:44, 11 июля 2011

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There is a somewhat finite amount of water on our planet that has been used over and over and over.  Comets bring our only fresh supply. Water vapor moves through the atmosphere, some of it condensing (turning to liquid water) to form clouds and precipitation. When this precipitation reaches land surfaces in and around the Celery Bog, the water can seep into the soil (infiltration) or move across the surface (runoff). Some of the water that infiltrates cannot travel down through the underlying till (dense glacial sediments) layers, thus it becomes shallow groundwater that helps keep the marsh wet in the dry part of the year. However, some of the water trickles through layers of till with intermingled lenses of sand and gravel, and eventually the water reaches aquifers (groundwater).

The water fr om the Celery Bog is a source for the Wabash (locally known as Teays) River Valley Aquifer, which provides the water that the City of West Lafayette and Purdue University utilize every day. This is a relatively large aquifer that is 6 miles wide and between 200 to 300 feet deep. The water is drawn up from underground via wellfields, and the aquifer has a capacity of about 18,000,000 gallons. As of 2001, the average amount of water drawn daily was a little over 10,000,000 gallons.  Aquifers have lim its too - and care needs to be taken in the surrounding watersheds to ensure that both good water quantity and quality continues to feed the aquifer, our main source of water.

Runoff can either travel to an area wh ere it can pass through the soil, or it enters a body of water such as a marsh (in our case, the Celery Bog). Surface water can also travel back into the atmosphere before it has a chance to enter the ground (evaporation). Similarly, plants use water that infiltrates the soil and then release some of the water into the atmosphere through a process called transpiration. One single drop of water is recycled constantly through the hydrologic cycle by precipitation, runoff and/or infiltration, evaporation or transpiration, and again by precipitation.

Run and get a glass of water and put it on the table next to you. Take a good long look at the water. Now -- can you guess how old it is?
The water in your glass may have fallen fr om the sky as rain just last week, but the water itself has been around pretty much as long as the earth has!

When the first fish crawled out of the ocean onto the land, your glass of water was part of that ocean. When the Brontosaurus walked through lakes feeding on plants, your glass of water was part of those lakes. When kings and princesses, knights and squires took a drink fr om their wells, your glass of water was part of those wells.

And you thought your parents were OLD

The earth has a lim ited amount of water. That water keeps going around and around and around and around and (well, you get the idea) in what we call the "Water Cycle".

This cycle is made up of a few main parts: evaporation (and transpiration) condensation precipitation collection

Evaporation:   Evaporation is when the sun heats 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 and goes into the air. Do plants sweat?  Well, sort of.... people perspire (sweat) and plants transpire. Transpiration is the process by which plants lose water out of their leaves. Transpiration gives evaporation a bit of a hand in getting the water vapor back up into the air.

Condensation: Water vapor in the air gets cold and changes back into liquid, forming clouds. This is called condensation. You can see the same sort of thing at home... pour a glass of cold water on a hot day and watch what happens. Water forms on the outside of the glass. That water didn't somehow leak through the glass! It actually came from the air. Water vapor in the warm air, turns back into liquid when it touches the cold glass.

Precipitation: Precipitation occurs when so much water has condensed that the air cannot hold it anymore. The clouds get heavy and water falls back to the earth in the form of rain, hail, sleet or snow.

Collection:

When water falls back to earth as precipitation, it may fall back in the oceans, lakes or rivers or it may end up on land. When it ends up on land, it will either soak into the earth and become part of the “ground water” that plants and animals use to drink or it may run over the soil and collect in the oceans, lakes or rivers wh ere the cycle starts

all over again.