biofuel
~ - Ethanol produces CO2 when its burned
- Switch grass is considered carbon negative (absorbs CO2 as it grows)
- It is essential that non-food crops are used in ethanol production
- Recent advances indicate that algae may be used as a source
renewables
~ - A wide variety of renewable...
- Surface water is found in runoff, lakes, ponds, swamps, streams and rivers
glacial water
✓✓✓✓~ 76% of fresh water
- Not renewable
- Melting into oceans (lost)
- Original source of most current surface water resources on earth
groundwater
✓✓✓✓~ 24% of fresh water
- Groundwater is water found in the pores of soil and sediment, plus narrow
fractures in bedrock
- Largest reservoir of fresh water that is readily available to humans
,water table
✓✓✓✓~ The upper level of the saturated zone of groundwater
- where groundwater is at zero pressure
zone of aeration
✓✓✓✓~ Above the water table
- Water cannot be pumped by wells
zone of saturation (phreatic zone)
✓✓✓✓~ zone where all open spaces in sediment and rock are completely filled with water
- Water within this zone is called "groundwater"
porosity of ground
✓✓✓✓~ Determines storage capacity for water
- primary porosity: in sand and rocks
- secondary porosity: in fractures and caverns
aquitard
, ✓✓✓✓~ An impermeable layer that hinders or prevents water movement (such as clay or
unjointed rock)
aquifer
✓✓✓✓~ permeable rock strata or sediment that transmits groundwater freely (such as sand
and gravels)
exposed soil or sediment
✓✓✓✓~ At depth the pore space between grains would be filled with water
- A well in this rock has a screen to allow water to flow from the soil to the well
- The water table is the height of water in the well after reaching a static level
(no flow)
exposed fractured rock
✓✓✓✓~ At depth these joints would be filled with water
A well in this rock intersects and drains the fractures
There is no underground "pool"
Porosity
✓✓✓✓~ - Percentage of total volume of rock or sediment that consists of pore spaces
- how much groundwater can be stored
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