Net Radiation Of Evaporable Water Given Daily Potential Evapotranspiration Calculator

Formula Used:

\[ Hn = \frac{(PET \times (A + \gamma) - (Ea \times \gamma))}{A} \]

Daily Potential Evapotranspiration (PET):

mm/day

Slope of Saturation Vapour Pressure (A):

mmHg/°C

Psychrometric Constant (γ):

Parameter of Wind Velocity and Saturation Deficit (Ea):

Net Radiation of Evaporable Water (Hn):

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1. What is Net Radiation of Evaporable Water?

Net Radiation of Evaporable Water is the net radiation length per day influenced by the incoming solar radiation absorbed by the Earth's surface and the radiation reflected back. It's a crucial parameter in evapotranspiration studies and water balance calculations.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Hn = \frac{(PET \times (A + \gamma) - (Ea \times \gamma))}{A} \]

Where:

\( Hn \) — Net Radiation of Evaporable Water (mm/day)
\( PET \) — Daily Potential Evapotranspiration (mm/day)
\( A \) — Slope of Saturation Vapour Pressure (mmHg/°C)
\( \gamma \) — Psychrometric Constant
\( Ea \) — Parameter of Wind Velocity and Saturation Deficit

Explanation: This formula calculates the net radiation available for evaporation by considering the energy balance between potential evapotranspiration, vapour pressure characteristics, and atmospheric conditions.

3. Importance of Net Radiation Calculation

Details: Accurate calculation of net radiation of evaporable water is essential for hydrological modeling, irrigation planning, climate studies, and understanding the water-energy balance in ecosystems.

4. Using the Calculator

Tips: Enter all parameters with appropriate units. Ensure values are positive and within reasonable physical ranges for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for Net Radiation of Evaporable Water?
A: Values typically range from 0-10 mm/day, depending on climatic conditions, season, and geographical location.

Q2: How does slope of saturation vapour pressure affect the calculation?
A: The slope represents how vapour pressure changes with temperature, significantly influencing the evaporation potential.

Q3: What factors influence the psychrometric constant?
A: The psychrometric constant is primarily influenced by atmospheric pressure and varies with altitude and weather conditions.

Q4: When is this calculation most useful?
A: This calculation is particularly valuable in agricultural water management, hydrological modeling, and climate change impact studies.

Q5: Are there limitations to this formula?
A: The formula assumes steady-state conditions and may need adjustment for extreme weather conditions or complex terrain.