Water Resources
Soil & Agriculture
Atmosphere & Air Pollution
Land Use & Management
Energy Resources
100

A body of permeable rock which can contain or transmit groundwater.

What is aquifer?

100

The process of eroding or being eroded by wind, water, or other natural agents. 

What is erosion?

100

Gaseous compounds that absorb and emit infrared radiation, trapping heat in the Earth's atmosphere and preventing it from escaping into space.

What is greenhouse gases?

100

The clearing or thinning of forests by humans, usually for non-forest uses. 

What is deforestation?

100

Energy from a source that is not depleted when used, such as wind or solar power.

What is renewable energy?

200

An area or ride of land that separates waters flowing to different rivers, basins, or seas.

What is watershed?

200

The action of rotating around an axis or center.

What is crop rotation?

200

Rainfall made sufficiently acidic by atmospheric pollution that it causes environmental harm.

What is acid rain?

200

The process of replanting an area with trees.

What is reforestation?

200

A renewable energy source that uses the kinetic energy of wind to produce electricity or mechanical power.

What is wind power?

300

The underground boundary between the soil surface and the area where groundwater saturates the spaces between sediments and cracks in rock.

What is water table?

300

The process of increasing the concentration of salt in soil or bodies of water.

What is salinization?

300

A type of air pollution that occurs when nitrogen oxides and hydrocarbons react with sunlight to create ozone and other reactive chemical compounds. 

What is photochemical smog?

300

Cut down and remove every tree from an area.

What is clear-cutting?

300

A form of energy released from the nucleus. 

What is nuclear energy?

400

The supply of water to land or crops to help growth, typically by means of channels. 

What is irrigation?

400

An agricultural practice that involves building rigged platforms, or terraces, across hillside to create flat area for growing crops. 

What is terracing?

400

A layer in the earth's stratosphere at an altitude of about 6.2 miles containing a high concentration of ozone, which absorbs most of the ultraviolet radiation reaching the earth from the sun. 

What is ozone layer?

400
Economic development that is conducted without depletion of natural resources.

What is sustainable development?

400

A natural fuel such as coal or gas, formed in geological past from the remains of living organisms. 

What is fossil fuels?

500

The process of removing salt from seawater.

What is desalination?

500

A farming technique that involves plowing or planting across a slope's elevation contour lines. 

What is contour plowing?

500

Microscopic solid or liquid particles that are suspended in the air or water. 

What is particulate matter?

500

The uncontrolled expansion of urban areas.

What is urban sprawl?

500

The use of falling or fast-running water to produce electricity or to power machines.

What is hydropower?