Urbanisation cause temperature differences in Delhi: Govt

New Delhi: Earth Sciences Minister Jitendra Singh on Thursday said urbanisation was one of main causes that can influence the changes in temperature pattern in Delhi and form heat islands.

In a written reply in the Rajya Sabha, he said the steep rise in pre-monsoon surface air temperature, land surface temperature and relative humidity in Delhi/NCR of late was a cause of concern.

He said there has been a rise in maximum and minimum temperature over Delhi during pre-monsoon season during the last three years, but there was no such increase in relative humidity.

Several studies on the pre-monsoon temperature pattern of Delhi have found that urbanisation as one of main causes that can influence the changes in temperature pattern within the city and form heat islands, the minister said.

"This is reflected by the trends of difference in annual mean minimum temperature of the two stations of which one (Safdarjung) is within the city and the other is in the outer periphery in Delhi NCR (Palam)," Singh said.

He said India's prolonged spell of heat wave experienced during pre-monsoon season 2022 were due to the absence of rainfall and convective activities for a long period, absence of western disturbances and the subsidence of warm and dry air in lower and middle tropospheric levels over north Arabian sea and adjoining south Pakistan and Gujarat.

As an adaptive measure, the India Meteorological Department (IMD) in collaboration with local health departments have started 'heat action plans' in many parts of the country to forewarn about the heat waves and also advising action to be taken during such occasions.

NDMA and IMD are working with 23 states prone to high temperatures leading to heat-wave conditions to develop heat action plans, Singh said.