Unit 4 (Chapters 8 & 9) Flashcards
What percentage does freshwater make up on earth?
3 percent
How much fresh water on earth is accessible to humans?
1 percent
why is only 1 percent of freshwater on earth accessible to humans?
Because only 3-fourths of the freshwater on earth is surface water, and even then most surface water is as ice and glaciers.
A permeable layer of rock and sediment that contains groundwater.
Aquifer
An aquifer made of porous rock covered by soil out of which water can easily flow.
Unconfined Aquifer
An aquifer surrounded by a layer of impermeable rock or clay that impedes water flow.
Confined Aquifer
The uppermost level at which the water in a given area fully saturates rock or soil.
water table
A process by which water percolates through the soil and works its way into an aquifer.
Groundwater recharge
A natural source of water formed when water from an aquifer percolates up to the ground surface.
spring
A well created by drilling a hole into a confined aquifer.
Artesian well
An area lacking groundwater due to rapid withdrawal by a well.
Cone of depression
An infiltration of salt water in an area where groundwater pressure has been reduced from extensive drilling of wells.
Saltwater intrusion
water that exists aboveground and includes steams, rivers, ponds, and wetlands.
Surface water
Where did early human civilizations typically settle?
along major rivers
The land adjacent to a river.
Floodplain
Pavement or buildings that do not allow water penetration.
Impermeable surface
What is essential to global water distribution?
atmospheric water
An enlarged bank built up on each side of a river.
Levee
A structure built to prevent ocean waters from flooding adjacent land.
Dike
A barrier that runs across a river or stream to control the flow of water.
Dam
The water body created by damming river or stream.
Reservoir
A stair-like structure that allows migrating fish to get around a dam.
Fish ladder
A canal or ditch used to carry water from one location to another.
Aqueduct
What does LA and NYC rely on to meet their daily water needs?
Aqueducts