Dew fall in sand dune areas of India

Abstract

An attempt has been made to study the significance of dew in the sand dune areas of India. Dew data recorded by Duvdevani dew gauges at three India Meteorological Stations (Bikaner, Jaisalmer and Ganganagar) with dew so recorded at four different heights i.e., 5 cm, 25 cm, 50 cm and 100 cm above the ground from 1973 to 1976 is taken for analysis. Mean monthly dew amount per dew night for the three stations at all the four heights is presented and discussed. Variation of mean seasonal (September to April) dew amount with height is also presented. It is found that higher amounts of dew deposit occur during the three months December to February. The data for the year having maximum dew fall (1975–76) is taken and analysed in terms of rainfall and potential evapotranspiration during the season. Ganganagar shows highest percentage of dew in 1975–76 when compared to actual seasonal rainfall (37%) and normal seasonal rainfall (27%); which is about 14% of the actual potential evapotranspiration and 18% of the normal potential evapotranspiration. Techniques standardized for afforesting shifting sand dunes are mentioned and recommended tree species for afforestation are presented.