7. Evapotranspiration Equations

Try these first

1. 1.

   What does ET₀ stand for?

   Hint

   Think about what measures the water loss from crops.

2. 2.

   Name one factor affecting evapotranspiration.

   Hint

   Consider environmental conditions.

3. 3.

   What is the main purpose of the FAO Penman-Monteith Equation?

   • To calculate rainfall
   • To estimate reference evapotranspiration
   • To measure soil moisture

   Hint

   Consider what it measures in relation to water loss.

4. 4.

   True or False: Vapor Pressure Deficit (VPD) affects the rate of evapotranspiration.

   • True
   • False

   Hint

   Think about moisture levels affecting evaporation.

5. 5.

   A region records Rn = 20 MJ/m²/day, G = 0.1 MJ/m²/day, T = 30°C, u_2 = 4 m/s, e_s - e_a = 2 kPa, Δ = 0.15 kPa/°C, and γ = 0.067 kPa/°C. Calculate ET₀ using the FAO Penman-Monteith Equation.

   Hint

   Substituting values into the equation step by step will yield the correct answer.

6. 6.

   Discuss how potential evapotranspiration (PET) might differ during summer versus winter in a temperate climate.

   Hint

   Consider how temperature influences water evaporation rates throughout the seasons.