Earths Water

Earths WaterWhat are some global concerns about water?Where is most of the water?Most valuable resourceLess than 3% is freshwaterMost of that in unavailable0.49% available Constantly circulating

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(2%)(.62%)Water CycleEvaporationPrecipitation

Infiltration or runoffStoredRepeat the cycle

Runoff occurs when precipitation rate is higher than the infiltration rateWater is then stored either underground as groundwater or in glaciers/snow packs until it makes its way to a body of water or it evaporates directlyPlants can also put water into the air through transpiration and breathing organisms a little also through evaporationThe worlds oceans are relatively constant in height and this indicates that the cycle is fairly stable and what goes into the oceans is about what goes out; average annual precipitation over the Earth equals the amount of water that evaporates4ReservoirDefinitionResidence time

Project ReflectionEffectiveness of group membersWere you a good group member? Give a specific example.Was person A a good group member? Give a specific example.Was person B a good group member? Give a specific example.Was person C a good group member? Give a specific example.What did you learn from presenting to the town council of people not from this class?

Daily Review #1How much of Earths water is freshwater?Where is the majority of Earths water? In what reservoir does water stay the longest? Where does the water you drink at school come from?What was surprising or interesting that you discovered from completing the water footprint activity?

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Direct vs. Indirect Water UsageDirectDrinking waterShowerWatering your lawnIndirect FoodClothes

Groundwater What and Why?What?Infiltrated waterMajor source forConsumptionIrrigationSurface water (streams, etc.)

Groundwater is precipitation that has not run off, been absorbed by plants or evaporated, but has been able to seep into the ground through the spaces in between the particles of soilWe use groundwater for drinking water, irrigation or crops and when it meets the surface water it contributes to streams and lakes or even is the original source of these bodies of surface water9What happens underground?Where it goes is changed byPorosityPermeabilityUndergroundAerated zoneSaturated zoneWater tableAquifer

Once underground and to get underground water needs to move between soil particles which is changed by: porosity = amount of space found between soil particles, permeability = how easily water flows through a material and is changed by how well connected the pore spaces are in the soilUnderground areas where there is air and water in the spaces between soil particles that is called the aerated or unsaturated zone, more water could enter this and does as it flows downward because of gravityOnce you reach an area where there is only water between soil particles, you have reached the saturated zone, everything including spaces between minerals inside of rocks is filled with water; water in this area is called groundwaterThe dividing line between the saturated and aerated zone is called the water table; this is not a perfect line, but rises and falls and changes over time due to the type of soil (porosity and permeability) and the amount of water available at the time; to get free flowing water you must reach the water table with a well or the surface to create a stream or lakeAn aquifer is a zone of rock that groundwater can flow through; has high porosity and permeability, allows water to be delivered at a usable rate; where we get groundwater from to use at the surface for irrigation and consumption10Groundwater movesDue to gravityImpacted by porosity and permeabilityNot a straight lineDischarge vs. rechargeCones of depressionCaused by wellsMove to lowest pointChange the water tableNeed to drill new wellsLand subsidence

Water will move downward mainly because of gravity, but the actual path of water is effected by the spaces available and permeability of the rock and so the path is usually not a straight line and sometimes the water will encounter a layer that is impermeable and not be able to flow down any more or up any moreWater leaves the ground by being pumped out and used or flowing out at a surface location (lake, stream, etc.) = discharge; recharge is how quickly water fills back up the spaces available in the saturation zone; these are not usually equal, if discharge is greater the water table will decrease, if the recharge is greater then the water table will increaseWhen water is pumped out it creates a cone of depression in the groundwater because you are removing the water in that area, surrounding water will then move to fill in the spaces because it is now the lowest location; if not recharged quickly then the water table will decrease; the more pumping the greater this change that could occurIf the water table does change, you might need to drill a new well because your old well is now above the water table, the land could also subside because there is more air in the soil and is more likely to be able to sink, or the groundwater in that area has created caves that are no longer filled with water and are thus empty

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In the country, we are using groundwater at a much higher rate than it is being rechargedLand subsidence has occurred in the California area because of this difference in discharge and recharge, to a very large extent12Ogallala AquiferWhere?What? Why is it significant?Much higher dischargeLand subsidenceLoss of drinking waterLoss of water for irrigationSaltwater intrusion

Located under most of the middle of the countryMajor aquifer that supplies a major part of the groundwater for the country especially agricultural areasCurrently the water from this aquifer is being used a much higher rate than it is being rechargedThis could result in land subsidence, loss of drinking water for some very arid parts of the country, loss of water for irrigation or just supplying agricultural land, in some areas near the ocean if the water table is lower it will/does result in saltwater seeping into the saturation zone and contaminating the water supply (this is happening along the east coast already)

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Daily Review #2What two factors affect groundwater?How does the pumping out of water in a well effect the water table and why?What is the Ogallala Aquifer and why is it important?What do discharge and recharge mean?

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