Which condition would most likely increase evapotranspiration rates?

Which condition would most likely increase evapotranspiration rates?

• A. Higher temperature.
• B. Lower temperature.
• C. Lower solar radiation.
• D. Lower wind speed.

Answer: (A)

Evapotranspiration is driven by the amount of energy available to move water from surfaces into the air and by how strongly the air demands moisture. When temperature rises, more energy is available to convert liquid water to vapor, and the air can hold more water vapor, increasing the vapor pressure deficit between the surface and the surrounding air. That larger deficit makes it easier for water to move into the air, so both evaporation and plant transpiration rates rise. If temperature were lowered, the energy input drops and the air’s capacity to hold moisture decreases, reducing ET. Lower solar radiation means less energy reaching the surface, also reducing ET. Lower wind speed reduces the removal of water vapor from around the surface, which slows ET. So among the options, higher temperature amplifies the driving force for evapotranspiration, making it the best choice.

Evapotranspiration is driven by the amount of energy available to move water from surfaces into the air and by how strongly the air demands moisture. When temperature rises, more energy is available to convert liquid water to vapor, and the air can hold more water vapor, increasing the vapor pressure deficit between the surface and the surrounding air. That larger deficit makes it easier for water to move into the air, so both evaporation and plant transpiration rates rise.

If temperature were lowered, the energy input drops and the air’s capacity to hold moisture decreases, reducing ET. Lower solar radiation means less energy reaching the surface, also reducing ET. Lower wind speed reduces the removal of water vapor from around the surface, which slows ET. So among the options, higher temperature amplifies the driving force for evapotranspiration, making it the best choice.