70% of Earth’s surface is covered by water
Found in 5 main repositories
- 97% is in oceans as salt water
-
3% is freshwater
- 77% of this is in Ice and Glaciers
- 22% of this is in GW
- Rest is else where such as in atmosphere
- Only this freshwater can be consumed
- Because most of the water is GW, less than 1% is easily accessible
Hydrologic Cycle:
- Evaporation
- Transpiration
- Condensation
- Sublimation
- Precipitation
Groundwater:
- Found in small places between layers of rocks and sediment
- Called an aquifer
- Permeable Layer of rock and sediment that contains groundwater
- Water can flow easily in and out of an unconfined aquifer
- Water is trapped in a confined aquifer
- surrounded by layers of impermeable rock (can be clay)
- Called an aquifer
- Water Table
- Uppermost level at which water in a given area fully saturates rock/soil
Groundwater Recharge
- How water fills up an aquifer through ways such as precipitation
- Can only reach through permeable layers
Aquifers are important fresh water sources for plants
Water can sometimes naturally reach surface though springs
- Humans however make artesian wells to get water from GW
- Sometimes water has to be pumped, but can sometimes just push up b/c pressure
Aquifer recharge time ranges from weeks to thousands of years
- Large scale use of confined aquifers is unsustainable b/c this
When water is rapidly extracted, it can cause a cone of depression
Sometimes when water is rapidly pumped near a costal area, it can cause saltwater intrusion
- SW Intrusion is infiltration of salt water in an area where GW pressure has been reduced in costal areas due to rapid pumping of water
