Trends and relationships of dew with meteorological factors in the semi−arid region of south−eastern Rajasthan

Abstract

Dew is an additional and significant source of water which needs to be accounted for meeting crop water requirements, especially in arid and semi−arid regions. Therefore, the present study was carried out to analyze the dew accumulation, trends of dewfall, evaporation, relative humidity, rainfall and temperature over 21 years, and its relationship with these meteorological parameters in semi−arid regions of south−eastern Rajasthan. The results indicated a declining trend of dew deposition and evaporation, while a significant (p<0.05) increasing trend of diurnal as well as nocturnal relative humidity over the years (1999−2000 to 2019−20). There was a negative correlation of dew amount with evaporation and mean seasonal temperature, while relative humidity was positively correlated to the amount of dew deposition. The total amount of seasonal dew deposition was significantly (p<0.01) and positively correlated to the total seasonal rainfall. Thus, it can be concluded that the amount of dew formation of a particular agro−ecosystem is most closely related to the micro meteorological conditions, and increases with an increase in relative humidity, rainfall and decrease with increased air temperature and evaporation.