Determining the linkages between atmospheric aerosol and drought: a study over Assam
Student name: Ms Suchita Mitra
Guide: Dr Anu Rani Sharma
Year of completion: 2013
Host Organisation: TERI University
Abstract: The present study deals with the connection between atmospheric aerosol particles and
drought in Assam through analysis of satellite data. Meteorological parameters like
rainfall, aerosol optical thickness, type of aerosol concentration, land surface temperature,
relative humidity and anthropogenic factor like forest fire are observed to be closely knitted
in a vicious circle together contributing to drought. Positive relation between NDVI and
Rainfall is observed. Whereas NDVI, the main indicator of drought, is found to be
negatively correlated with atmospheric aerosol loading and surface temperature. Relative
humidity is significantly low during the drought seasons in 2012 compared to 2011 which
was a normal year. Overall temporal variation in AOD, UV-AI and LST shows increasing
trend from 2011 to 2012 while NDVI and Rainfall show decreasing trend. The study also
revealed increase in occurrences of forest fire in the southern hilly areas from 2011 to 2012
leading to higher concentration of smoke and dust in the atmosphere. These particles get
transported to the northern districts, under the influence of South west monsoon winds,
where higher AOD values are observed. The tea gardens of these areas are worst affected
by drought during the season of first flush.
Keyword: Drought, NDVI, Aerosol Index, LST, wind vector
