As India faces ‘Amphan’, know what are cyclonic storms and ‘storm surges’
New Delhi | Jagran News Desk: The Super Cyclonic Storm ‘Amphan’ will be crossing West Bengal-Bangladesh coast between Digha and Hatiya close to Sunderbans at around 4 pm today, and will make the landfall with a wind speed of 155-165 kmph gusting to 185 kmph, the Indian Met Department said today.
The IMD has also said that a storm surge of a height of about four-five metre above the astronomical tide will inundate the low-lying coastal areas in Bengal from the cyclonic storm. The storm has also has triggered downpour in coastal Odisha and Gangetic West Bengal, uprooting trees, flattening fragile dwellings and forcing evacuation of over four lakh people.
Meanwhile, the Kolkata airport has also suspended all its operations, including the special planes that were deployed to bring back Indians stranded abroad due to Covid-19, till 5 am tomorrow and has issued a red alert in various coastal districts.
Here are some important facts about 'Amphan' and tropical cyclones:
Cyclones are low-pressure systems which form over warm tropical waters with a very strong wind force near its centre, which can even extend hundreds of kilometres from the centre. The Cyclones often led to torrential rains and cause heavy damage to life and property.
Cyclones can lead to disastrous storm surges when they make a landfall. They can prove to be the deadliest part of a cyclone and are only partially affected by wind speeds. The term "storm surge" refers to rising seas whipped up by a storm, creating a wall of water several metres higher than the normal tide level. The surges can sometimes be so powerful that can extend for kilometres inland.
The size of a storm surge depends on several factors, such as storm intensity, forward speed, the size of a storm and the angle of approach to the coast. The underlying features of the land at the coast, including bays and estuaries, also play the formative role for a storm surge.
Earlier, people failed to flee the storm surge because of the lack of knowledge about surge’s deadly threat. Similar type of incident happened in central Philippines during the 2013's Super Typhoon Haiyan, which claimed lives of 7,350 or missing.
According to the Indian Met Department (IMD) the Cyclone Amphan is expected to make a storm surge of up to five metres (16 feet) in the low lying areas of West Bengal, and up to 3.5 metres in Bangladesh.
Bangladesh is vulnerable to cyclones due to its location at the triangular-shaped head of the Bay of Bengal, the geography of its coastal area and its high-population density, according to experts.
Hundreds of thousands of people living around the Bay of Bengal have been killed in cyclones in recent decades.
The tropical cyclone season in the Bay of Bengal and neighbouring Arabian Sea has two peaks around May and November, according to the World Meteorological Organisation as reported by nes agency AFP.
Many cyclones formed in the western Pacific Ocean travel in northwest direction before arriving in Bay of Bengal. Some move towards southeastern coast of India, while others divert northeast to reach West Bengal and Odisha.
Here are some of the deadliest storms in history to have formed in the Bay of Bengal, including one in 1970 that killed half a million people in what is modern-day Bangladesh.
*Some 138,000 died in Bangladesh in 1991 in a tidal wave caused by a cyclone.
*In 1999 in India's Odisha state, 10,000 people were killed by a cyclone.
*In 2007, Cyclone Sidr killed at least 4,000 in southern Bangladesh.
*In 2008 Cyclone Nargis, which devastated Myanmar's Irrawaddy Delta, killed about 140,000 people.
(With Agency Inputs)
Posted By: Talib Khan