| A | B |
|---|
| Pollution | Contaminants in the environment. |
| Aquifer | A natural underground area in limestone where large quantities of water accumulate. |
| Permeability | The measure of the ability of an earth material to let water pass through it. |
| Porosity | The measure of the number and size of spaces in soil or rocks. |
| Percolation | The downward movement of water through soil. |
| Water Table | The upper zone of groundwater. |
| Surface Water | Water in lakes, rivers, wetlands and oceans. |
| Groundwater | Water that is held or flows under the ground. |
| Runoff | The water that drains on the surface from an area after precipitation. |
| Watershed | The land area from which the surface water drains into a specific river, lake or ocean. |
| Evaporation | The physical change of a liquid to a gas. |
| Precipitation | The moisture that falls as rain, snow sleet or hail. |
| Condensation | The physical change of a gas to a liquid. |
| Solar Energy | Energy from the Sun. |
| Continental Divide | The line across the Rocky Mountains that separates the Atlantic from the Pacific watershed. |
| Transpiration | The process of water vapor leaving the stomata of plant leaves. |
| Sublimation | The physical change of a solid directly to a gas such as happens with dry ice (CO2). |
| Mouth of a river | Point of flow into another body of water. |
| Source of a river | Origin. |
| Tributary | A smaller stream or river flowing into a larger one. |
