1. What is the Evaporation Calculation Formula?

The evaporation rate formula calculates the rate of evaporation based on the difference between saturation vapor pressure and actual vapor pressure, divided by aerodynamic resistance. It's widely used in meteorology, hydrology, and environmental science.

2. How Does the Calculator Work?

The calculator uses the evaporation formula:

Where:

• \( Rate \) — Evaporation rate (mm/s)
• \( e_s \) — Saturation vapor pressure (kPa)
• \( e_a \) — Actual vapor pressure (kPa)
• \( r_a \) — Aerodynamic resistance (s/m)

Explanation: The formula represents the driving force for evaporation (vapor pressure difference) divided by the resistance to vapor transfer.

3. Importance of Evaporation Rate Calculation

Details: Accurate evaporation rate estimation is crucial for water resource management, agricultural planning, and climate modeling.

4. Using the Calculator

Tips: Enter all values in the specified units. Ensure e_s > e_a for meaningful results, and all values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is saturation vapor pressure?
A: The maximum vapor pressure that can exist at a given temperature, representing air fully saturated with water vapor.

Q2: How is actual vapor pressure measured?
A: Typically measured using psychrometers or calculated from dew point temperature.

Q3: What affects aerodynamic resistance?
A: Surface roughness, wind speed, and atmospheric stability are key factors.

Q4: Are there limitations to this formula?
A: It assumes steady-state conditions and may not account for all microclimate variations.

Q5: What are typical evaporation rates?
A: Rates vary widely but typically range from 0-0.5 mm/s depending on conditions.