Evaporation Rate Calculator

Calculate the rate of water evaporation from open surfaces based on environmental conditions. This calculator helps estimate water loss from pools, lakes, reservoirs, and other water bodies.

Why Use This Calculator?

• Estimate water loss from swimming pools
• Plan irrigation schedules for agriculture
• Manage water resources effectively
• Calculate cooling tower evaporation
• Understand environmental water cycles

How It Works

The calculator uses the following factors to determine evaporation rate:

1. Air Temperature: Higher temperatures increase evaporation
2. Relative Humidity: Lower humidity increases evaporation
3. Wind Speed: Faster wind speeds accelerate evaporation
4. Surface Area: Larger surfaces lose more water
5. Water Temperature: Optional factor for more accurate results

Understanding the Results

The calculator provides evaporation rates in:

• Liters per hour
• Gallons per day
• Millimeters of depth per day

Typical Evaporation Rates

• Low: < 2mm/day
• Moderate: 2-5mm/day
• High: 5-8mm/day
• Very High: > 8mm/day

Common Use Cases

1. Pool Maintenance

   • Water replacement planning
   • Chemical balance adjustments
   • Cover effectiveness assessment

2. Agricultural Planning

   • Irrigation scheduling
   • Crop water requirements
   • Water conservation strategies

3. Environmental Studies

   • Lake and reservoir management
   • Climate impact assessment
   • Water resource planning

Technical Notes

• Uses modified Penman equation for calculations
• Accounts for vapor pressure deficit
• Includes wind speed effect multiplier
• Considers surface area and shape factor

Tips for Accurate Results

1. Temperature Measurements

   • Use average daily temperature
   • Consider both air and water temperature
   • Account for seasonal variations

2. Wind Speed

   • Measure at standard height (2m above surface)
   • Use average wind speed over time
   • Consider local wind patterns

3. Humidity Readings

   • Use relative humidity percentage
   • Take measurements at consistent times
   • Account for daily variations

Frequently Asked Questions

How does temperature affect evaporation?

For every 10°C increase in temperature, the evaporation rate approximately doubles, assuming other factors remain constant.

Why is wind speed important?

Wind removes saturated air above the water surface, replacing it with drier air that can accept more water vapor, accelerating evaporation.

How can I reduce evaporation loss?

1. Use pool covers
2. Install windbreaks
3. Maintain lower water temperature
4. Reduce water surface exposure
5. Schedule water activities during cooler periods

What affects evaporation most?

The main factors in order of typical impact are:

1. Temperature difference
2. Relative humidity
3. Wind speed
4. Surface area
5. Water temperature