Evapotranspiration
The total amount of water that is transferred from the earth’s surface to the atmosphere. It is made up of the evaporation of liquid or solid water plus the transpiration from plants.
Water
Refers to the chemical compound, H2O, as well as its liquid form. At atmospheric temperatures and pressures, it can exist in all three phases: solid (ice), liquid (water), and gaseous (water vapor). It is a vital, life-sustaining part of life on earth.
Atmosphere
The gaseous or air portion of the physical environment that encircles a planet. In the case of the earth, it is held more or less near the surface by the earth’s gravitational attraction. The divisions of the atmosphere include the troposphere, the stratosphere, the mesosphere, the ionosphere, and the exosphere.
Evaporation
The physical process by which a liquid, such as water is transformed into a gaseous state, such as water vapor. It is the opposite physical process of condensation.
Transpiration
The process by which water in plants is transferred as water vapor to the atmosphere.