1. What is the Pond Evaporation Rate Equation?

The pond evaporation rate equation estimates the daily water loss from a pond due to evaporation. It considers the surface area of the pond and the difference between water vapor pressure and air vapor pressure.

2. How Does the Calculator Work?

The calculator uses the evaporation equation:

Where:

• \( E \) — Evaporation rate (m/day)
• \( A \) — Pond surface area (m²)
• \( P_w \) — Water vapor pressure (kPa)
• \( P_a \) — Air vapor pressure (kPa)

Explanation: The equation calculates the daily evaporation rate based on the vapor pressure difference, which drives the evaporation process.

3. Importance of Evaporation Rate Calculation

Details: Accurate evaporation rate estimation is crucial for water resource management, pond design, irrigation planning, and understanding water balance in aquatic systems.

4. Using the Calculator

Tips: Enter pond surface area in square meters, water vapor pressure and air vapor pressure in kPa. All values must be valid (area > 0, vapor pressures ≥ 0).

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this evaporation estimate?
A: This provides a basic estimate. Actual evaporation can vary with wind speed, humidity, and temperature gradients.

Q2: How do I measure vapor pressures?
A: Vapor pressures can be calculated from temperature and relative humidity measurements using standard meteorological formulas.

Q3: What are typical evaporation rates?
A: Rates vary by climate but typically range from 2-10 mm/day in temperate regions to 10-20 mm/day in arid regions.

Q4: Does this account for rainfall?
A: No, this calculates only evaporation. Net water loss would subtract rainfall from evaporation.

Q5: Can this be used for large lakes?
A: The equation works best for small ponds. Large lakes may need more complex models accounting for fetch and wind effects.