Urbanisation linked to heavy rains in southern States
HYDERABAD: Increased urbanisation is a possible cause for heavy rainfall in cities of Telangana, Tamil Nadu and Kerala over the past few years, according to a study by the University of Hyderabad (UoH).
A team, led by Professor Karumuri Ashok from the Centre for Earth, Ocean and Atmospheric Sciences of the UoH, examined whether a common factor, the changing Land Use Land Cover (LULC) in southern States of the country, has any implications for the heavy rainfall.
Several heavy rainfall events have been reported in cities of South India, including the extreme rainfall that created havoc in Chennai and nearby areas in Tamil Nadu in December 2015 and the heavy rainfall over Hyderabad and adjoining regions in Telangana. The study showed that the precipitation during heavy rainfall events in these States has significantly increased from 2000 to 2017.
The researchers found distinct LULC changes in these three states, which led to higher surface temperatures and a deeper and moist boundary layer. These, in turn, caused a relatively higher convective potential energy and, consequently, heavier rainfall.
The study also suggests that increasing urbanisation in Telangana and Tamil Nadu is likely to enhance rainfall during the heavy rainfall events by 20 to 25 per cent. The findings were recently reported in the ‘Quarterly Journal of Royal Meteorological Society’. Professor Ashok feels that improving the density of observational rainfall and other weather parameters may help in forecasting extreme rainfalls at the city level.