The ISI standard pan evaporimeter
The pan coefficient for US class A pan is 0.7 while it is 0.8 for ISI standard Pan.
A 6-h storm had 6 cm of rainfall and the resulting runoff was 3 cm. If the φ-index remains at the same value the runoff due to 12 cm of rainfall in 9 h in the catchment is
Under identical conditions evaporation from sea water is
The highest value of annual evapotranspi ration in India is at Rajkot, Gujarat. Here the annual PET is about
In estimating the maximum floods for design purposes, in the absence of any other data, the φ -index is usually assumed as
Lysimeter is used to measure
Penman’s equation is based on
Consider the following chemical emulsions:
1. Methyl alcohol
2. Cetyl alcohol
3. Stearyl alcohol
Which of the above chemical emuisions is/are used to minimize the loss of water through the process of evaporation?
Certain chemicals such as cetyl alcohol (hexadecanol) and stearyl alcohol (octadecanol) form monomoiecular layers on a water surface. These layers, act as evaporation inhibitors by preventing .the water molecules to escape past them.
The value of W index as compared to φ-index is
The annual potential evapotranspiration for a major part of our country lies in the range of