Watersheds

What can excessive groundwater withdrawal lead to?

Subsidence (land sinking).

Why should farms be placed upstream from factories?

To prevent pollution from contaminating food and water supplies.

What is a dead zone?

A low-oxygen area caused by pollution.

What causes algae blooms?

Excessive nitrogen and phosphorus runoff from fertilizers.

How can we help prevent water contamination?

By lining landfills.

What is contamination?

The introduction of harmful substances into natural systems.

What is one way to overuse water?

Leaving the water running while brushing teeth.

How can runoff from human developments affect water temperature?

It often increases the temperature of nearby water sources.

Pollution that comes from one particular point.....

Point source pollution

Water that flows beneath the Earth’s surface

Ground water

The water table can rise or fall depending on the amount of precipitation an area receives.

True

groundwater

fresh water that is located beneath the Earth's surface

aquifers

the underground permeable layers where most groundwater flow takes place.

water table

the upper boundary of the zone of saturation.

recharge

the process in which water from precipitation and runoff is added back to the zone of saturation.

runoff

water that flows over the ground surface rather than soaking into the ground

surface water

Water above the surface of the land, including lakes, rivers, streams, ponds, floodwater, and runoff.

Watershed

An area of land where the surface water and groundwater drain into a particular body of water separated from each other by drainage divides.