Factors Affecting Evaporation losses and How it Occures?

What is Evaporation?

Evaporation is the process in which liquid changes into a gaseous state at boiling point is known as evaporation.Evaporation is one of the processes in the hydrologic cycle.In this article, we are going to learn about factors affecting evaporation losses.

This cycle causes evaporation losses.The hydrological cycle consists of precipitation, evaporation, infiltration, condensation etc…

Evaporation Losses

Evaporation losses

According Daltons law

E=C (Es-Ea)

C=a+bV

  • a=b=constants.
  • V=wind velocity in km/hr
  • Es=Saturation vapour pressure at the water surface
  • Ea=Actual vapour pressure.

Factors Affecting Evaporation losses

1.Solar Radiation

The main factor affecting evaporation losses is due to solar radiation.Solar radiation is directly proportional to the rate of evaporation

2.Surface area of water

Greater the surface area more evaporation loss.The evaporation loss is directly proportional to the surface area of water.

3.Nature of soil

In wet soil evaporation is faster, the evaporation is more for black cotton soils than red soils.

4.Depth of water

As the depth of water in the catchment increases the rate of evaporation is lesser.Because the surface temperature is much lesser.As the depth increases, the heat from the solar radiation will transmit downwards(from the surface to the bottom of the water body).Thus the surface temperature is lesser and also evaporation loss will be lesser.

The evaporation rate of summer will be lesser than the winter due to the additional heat energy available, which is stored during the summer in deep waters.

5.Humidity

Ad the humidity increases the evaporation loss will decrease, because of the excess water molecules present in the air.

6.Wind Velocity 

Evaporation loss is directly proportional to the wind velocity.

7.Temperature of air

As the temperature of air increases the rate of evaporation increases.

8.Atmospheric pressure

Evaporation happens when the atmospheric pressure is more than the saturation pressure of water vapour molecules just above the water body.

That is

  • Ps>Pa – Evaporation happens
  • Ps<Pa-Water molecules return to a water body

9.Water quality

The last factor affecting evaporation loss is due to the presence of salts in water.The presence of dissolved salts present in the water decreases the evaporation.Thus sea water has lesser evaporation losses than the pure water at same conditions.

 

Read More

  1. How can be done evaporation losses calculation?Measurement of evaporation losses.
  2. What is precipitation and how it is formed?

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Shinu

Thanks for this post…very good. I love it

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