the rate of evaporation is high in june and july. why?
Answers
Evaporation records from pans are frequently used to estimate evaporation from lakes and reservoirs and ET from an area. Since information about monthly coefficients is not available in India, these coefficients are decided using the analogy of spatial variation from arid and humid regions to the conditions that prevail in India during winter and summer months. During the transition months, the ambient temperature and the pan temperature are considered to be the same. Also, as it is generally observed that a factor of 0.7 is accepted the world over as the coefficient on an annual basis, the monthly variation has to be plus or minus the value of the annual coefficient. According to these considerations, the monthly coefficients can be adopted as 0.6 in cold dry winter months, 0.8 in hot summer months and 0.7 in the transition months between the winter and the summer and the vice-versa. For this purpose, the parallel of 22° latitude has been taken as the demarcating line.