Dust emission from different soil types in the northwest and the Indo-Gangetic Plains of India

Nirmala D. Desouza

Abstract

Dust emission is a main source of aerosol in the atmosphere and is highly sensitive to wind velocity. Surface feature characteristics, soil properties and meteorological parameters also influence dust emission. Thus far, no study has referred to dust flux over the Indian subcontinent; therefore, we estimated dust flux using empirical equations and land cover data for seven locations in the northwest and the Indo-Gangetic Plains (IGP) having different soil types. Our study indicates differences in dust flux among locations. In the northwest, dust emission was initiated at a friction velocity of 0.23 to 0.27 m s–1 and dust flux was lesser than the IGP. In the IGP, dust emission was initiated at a friction velocity ranging from 0.22 to 0. 35 m s–1. Dust flux ranged from 0.073 to 0.084 kg m–1 s–1 at a given friction velocity (0.6 m s–1). It was observed that at low friction velocity, dust flux was low at locations with high clay content (> 20%) and sandy soils, compared to sandy loam and silt loam soil types. A reverse trend was observed at a higher friction velocity. Our study clearly indicates the effect of soil texture in dust emission.

Keywords

Dust emission, friction velocity, surface roughness, wind speed.

Full Text:

PDF