evapotranspiration

The loss of water from a given area and during a specified period of time, due to evaporation from the soil surface and to transpiration from plants. In arid conditions most of the precipitation returns to the atmosphere after some time, and does not participate in the deep soil water recharge. Potential evaporation (or evapotranspiration) is the amount of evapo-transpiration that would occur from a certain area if there were no restriction on water availability.