2 What is Ground Water?Ground Water: Water beneath the surface trapped in sediment and rock is called groundwaterMOST OF THE FRESH water available for human use is groundwater.
3 What happens to all of the water that falls from the sky? Evaporated into gas againSurface run-off to large bodies of waterTaken up by organismsPercolates into soil
4 What allows the water to percolate into the ground? Porosity and permeability-These are determined by the materials or types of rocks in the ground
5 Water table-the upper level of the ground that is saturated with water. The water is still moving, very slowly, and it is still part of the water cycle.Most of the water in the ground comes from precipitation that infiltrates downward from the land surface.
6 Why is the water table important? It is important because we can drill down to the level of saturation and bring up the groundwater as long as the material is permeable enough to pump water through.
7 Is the water table always in the same place? It is not level-it increases and decreases with the peaks and valleys of the land’s surface
8 Ground Water Unsaturated zone Saturated zone Zone that has some soil water, but varies due to rainfallThis area of the soil is not saturated with waterPorous or permeable zone of soil that is saturated with water
10 Aquifers Another term for ground water is "aquifer," This term is usually used to describe rock or soil formations capable of yielding enough water to supply peoples' uses.Aquifers are a huge storehouse of Earth's freshwater
11 How do we extract ground water from an aquifer? We can extract ground water using a pumpWe can only extract water from the ground if the aquifer is shallow enough (not too deep)AND if the water is flowing through the material the aquifer is made of (sandstone etc.)
12 Different Kinds of Aquifers UnconfinedWhen the “confining” layer of impermeable material is under the aquiferThis Aquifer is unconfined.
13 Different Kinds of Aquifers ConfinedWhen the Aquifer is under the impermeable confining layerThis Aquifer is confined by a layer of impermeable material above it.This Aquifer is considered to be artesian.
15 What is an “artesian” well? A well that is dug into an artesian aquifer.An artesian aquifer is an aquifer that is sandwiched between 2 layers of impermeable materialThis causes pressure to force the water up and to flow out of the well without pumping.
16 Do all wells need pumps?No pump is needed if the well is in a confined aquifer and the surface of the well is below the water table
17 Is there a danger associated with pumping all of the ground water out of a location? Yes-recharge rate (rates of water entering the aquifer) occur very slowly
18 Recharge ZonesGroundwater flows paths from areas of recharge to areas of discharge.Recharge occurs everywhere precipitation that falls on the land surface soaks into the ground, moves through the unsaturated zone, and enters the saturated parts of the subsurface.Recharge also can come from water in surface water bodies moving into the ground.
19 Discharge ZonesDischarge from the saturated subsurface material occurs at springs, streams, lakes, wetlands, bays, the ocean in coastal areas, and as transpiration by plants whose roots extend to near the water table.