- The natural environment or place where an organism, population, or species lives.
- Any discarded chemical (solid, liquid, or gas) that threatens human health or the environment. Also called toxic waste.
- One hectare equals to 2.47 acres. One square kilometer equals 100 hectares = 10 dka.
- Also called the water cycle. The cycle by which water evaporates from oceans and other bodies of water, accumulates as water vapor in clouds, and returns to oceans and other bodies of water as rain and snow, or as runoff from this precipitation or as groundwater.
- The system by which moisture reaches the ground and perculates through the soil to a particular water course or body of water.
- The energy of flowing or falling water used to generate electricity.
- The Earth’s supply of water (both liquid and frozen, fresh and salty).