Define Evapotranspiration.

• A. The loss of water to the atmosphere by a combination of evaporation and transpiration.
• B. The process of rainfall infiltration
• C. The evaporation rate of a lake surface
• D. The rate of groundwater recharge

Answer: (A)

Evapotranspiration is the total loss of water to the atmosphere from a landscape, combining evaporation from soil and water surfaces with transpiration from vegetation. This means it accounts for water vapor coming off bare soil or open water and also the water plants release when their stomata are open. In many ecosystems, plant transpiration can be a major part of ET, so it describes the overall vapor flux leaving the land surface, not just evaporation from a single water body.

The other concepts describe different processes: rainfall infiltration is water entering the soil; evaporation from a lake surface is only the evaporation component from a body of water (ET includes more than just that); groundwater recharge is water moving downward to replenish aquifers.