1. What is Meyer's Constant?

Meyer's Constant refers to an empirical coefficient in the Meyer evaporation formula, with values of 1.1 for deep water and 1.5 for shallow water. It represents the dependency of evaporation on water body depth.

2. How Does the Calculator Work?

The calculator uses Meyer's formula:

Where:

• \( C \) — Meyer's Constant
• \( E_m \) — Evaporation Loss per Month (m)
• \( \delta V \) — Change in Vapour Pressure (cm Hg)
• \( u \) — Mean Wind Velocity (cm/s)

Explanation: The formula calculates the empirical constant that relates evaporation rate to vapour pressure change and wind velocity, accounting for water body depth characteristics.

3. Importance of Meyer's Constant

Details: Meyer's Constant is crucial for accurate estimation of evaporation rates from water bodies, which is essential for water resource management, irrigation planning, and hydrological studies.

4. Using the Calculator

Tips: Enter evaporation loss in meters, change in vapour pressure in cm Hg, and mean wind velocity in cm/s. All values must be positive (wind velocity can be zero).

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for Meyer's Constant?
A: Meyer's Constant typically ranges from 1.1 for deep water bodies to 1.5 for shallow water bodies.

Q2: Why does water depth affect the constant?
A: Shallow water bodies heat up more quickly and have higher evaporation rates, requiring a larger constant to account for increased evaporation.

Q3: How accurate is Meyer's formula?
A: Meyer's formula provides reasonable estimates for evaporation rates but may require local calibration for specific conditions.

Q4: What units should be used for input values?
A: Use meters for evaporation loss, cm Hg for vapour pressure change, and cm/s for wind velocity as specified.

Q5: When is this calculation most useful?
A: This calculation is particularly useful for reservoir management, irrigation system design, and climate impact studies on water resources.