హైదరాబాద్ లో ఎండలెపుడూ ఎక్కువ, ఎందుకు?
Yesterday, Telangana health department authorities urged the people of the state to avoid going out during the afternoon in view of the ongoing heatwaves as they are likely to be hit by sunstroke. Of late, this type of warning from the health authorities has become routine. This begs a question as to why does Hyderabad face heatwaves so often. The answer is the location of the city in latitudes that receive direct sun rays during the summer months. Here is the explanation:
Telangana lies in Interior peninsular India which is closer to the Tropic of Cancer. The state lies in such latitudes that the rays of the sun fall vertically during the summer months. So, the capital Hyderabad faces more intense heat during summer than many of its South Indian neighbors such as Amaravati, Chennai, Thiruvananthapuram etc.
Tropics are hotter than the Equator, especially during summer and winter solstice. During the Summer solstice, the sun’s rays fall vertically over the tropic of cancer. Tropics are the areas that lie below and above the Equator, which are always hotter than the regions on the Equator.
If the air temperature at the Equator is 30 degrees Celsius, by the time it rises 10 km in the sky, travels polewards, and eventually descends into the tropics, its temperature would be raised by around 12 degrees Celsius. Therefore air temperature in the tropics (42 degrees Celsius) is greater than that of the Equator (30 degrees Celsius).
Telangana being a state that falls in the tropic of cancer comes under the Core Heatwave Zone (CHZ) of India. This zone runs across the states of Telangana, Andhra Pradesh, Himachal Pradesh, Uttarakhand, Delhi, Haryana, Uttar Pradesh, Rajasthan, Madhya Pradesh, Maharashtra, Bihar, Chhattisgarh, and West Bengal.
So, Hyderabad city, the capital of Telangana is highly prone to heatwaves. The city gets heated up at a faster rate and simmers in high temperatures. A report in the Times of India says the heatwaves that struck the state between 2014 and 2020 have claimed more than 1000 lives. But for the Covid-19 lockdown, which forced the people of the state to stay indoors, the heatwave death toll would have been much higher. The majority of the death occurred between 2015 and 2017.
According to Indian Meteorological Department (IMD), Hyderabad is the hottest state capital in South India. At the national level, it is the third hottest capital after Ahmedabad and Kolkata.
A heatwave alert is generally issued when the actual maximum temperature is more than the normal maximum temperature above 40 degrees Celsius. In the hilly regions the threshhold is 30 degress Celsius.
Heavewaves have been on the rise at in many station in CHZ. According to a report in Hindustan Times the number of heatwave days in India in a decade has increased from 413 in 1981-90 decade to 575 in 2001-10.
As per IMD Pune’s Climate Hazards and Vulnerability Atlas of India, Rajasthan, AP , Odisha are worst affected by heatwave that occurs in April, May , June and July,