Deposition and Mineralogical Characteristics of Atmospheric Dust in relation to Land Use and Land Cover Change in Delhi (India)

Abstract

This study highlights that the increasing urbanization and industrialization in Delhi are responsible for higher fluxes of atmospheric dust and its chemical constituents. Delhi has experienced a drastic change in land use and land cover area during the past two decades. Road lengths of the city have increased by 76% from 1985 to 2011. The number of mobile vehicles has reached 80,52,508 in 2014 from 24,32,295 in 1994. The industrial units in Delhi have increased by 39.54% in 2011 as compared to 1994 value. Atmospheric dust which is originated from soil in this region becomes carbon rich due to interaction of suspended soil with atmospheric pollutants. Emissions of carbonaceous aerosols from coal and petroleum combustions are mainly responsible for silica dominated soil dust transforming into carbon rich particulate matter. Such dust may play very important role in the atmosphere having significant influence on human health, global warming, climate change, radiative forcing, visibility, and cloud formation. It is expected that if the rate of development remains the same, green cover of the city invariably will be sized down in order to meet the demand of housing, transportation, industries, and so forth in proportion to the rising population.

Morphology, Chemical Composition and Mixing State of Atmospheric Aerosols from Two Contrasting Environments in Southern India

“…The chemical composition of the selected particles was determined using EDX, which revealed the presence of Silicon The microscopic examination revealed that the aerosol particles existed in several different geometries including 20 spherical, flat, agglomerate, irregular, cylindrical, crystal, ring, concave, chain and floccule; unlike the common assumption (spherical) in theory, but similar to those previously observed over different locations across the Indian region (Kumar et al, 2014;Pipal et al, 2014;Singh et al, 2014;Agnihotri et al, 2015;Tiwari et al, 2015;Pipal and Gursumeeran Satsangi, 2015;Mishra et al, 2015;Panda and Das, 2017). Such deviations of particles from spherical shape can alter the associated Single Scattering Albedo (SSA) (Mishra et al, 2015).…”

“…6). reported such a coating of Carbon on dust particles over the South Asian (Arimoto et al, 2006;Kumar et al, 2014) and the North-African (Deboudt et al, 2010) regions. Such a coating of carbonaceous species like BC on mineral dust would 'blacken' the dust and reduce its SSA making it more absorptive.…”

Environmental Protection and Regulations in India: Role of the Central Pollution Control Board

“…In addition, twenty-seven CNG buses were checked for meeting vehicular emission norms, of which twelve were low floor buses and fifteen were regular CNG buses (ibid., p. 73). Besides the monitoring of the vehicular pollution, the CPCB also conducted a study in 2014 to analyse the dust fall rates in Delhi, and while the dust fall rates are dependent on spatial and meteorological factors such as temperature, wind movement, etc., the deposition flux, that is, amount of dust per square meter per annum, for Delhi was found to be 35.28 according to the study (Kumar, Verma, & Kulshreshtha, 2014). The study concluded that decreasing green area and increasing residential and commercial built-up space contribute to high fluxes of dust fall in Delhi.…”

Climate Change and Urban Areas of India

“…Delhi has an annual average dustfall of 35 g/m 2 /yr with some of the sites showing figures as high as 168 g/m 2 /yr. 38 For comparison, residential areas adjacent to Jharia coal mines in Jharkhand have an average dustfall of 116.6 g/m 2 /yr. 39 Dust affects the urban environment especially air pollution, to which it is a major contributor.…”