Catastrophe in the East Coast – Amphan Cyclone
The extremely severe cyclonic storm Amphan intensified into the super cyclonic storm at 11.30 a.m. on 18th May 2020. Amphan had hit West Bengal and Odisha on 20th May 2020. More than 70 persons were killed. Thousands of kutcha houses in the coastal parts of West Bengal were damaged. The landfall started at 2.30 p.m. and continued till 7 p.m. The landfall was reported near Sagar Island of the Sundarbans between Digha in Purba Medinipur and Hatia in Bangladesh. Wind speeds of 150-190 km per hour were recorded in the coastal areas after the cyclone made landfall.
West Bengal had witnessed the fiercest cyclone which is more powerful than Bulbul (2019) and Aila (2009). In Kendrapara and Jagatsinghpur, people left their homes to cyclone shelters. 20 units of the National Disaster Response Force, 16 teams of the Odisha Disaster Rapid Action Force and 231 fire service units were deployed for the rescue operation.
Subject wise current affairs insight for UPSC civil service exam (Prelims and mains GS)
Prelims GS & Mains – GS1 (Geography)
- The wind circulation and movements that are developed around the low-pressure region are called cyclonic circulation.
- Winds blow inwards towards the centre, circulating in the anticlockwise direction in the northern hemisphere and clockwise in the southern hemisphere.
Two types of cyclone
- Tropical Cyclone
- Temperate Cyclone
They are well developed low-pressure regions into which violent winds blow. These cyclones develop in the region lying between tropics and originate only over the oceans. These are not regular and uniform. It is very disastrous.
Some important characteristics of tropical cyclones:
- The center of the cyclone where the wind system converges and vertically rises is called Eye. The Eye is a calm region with no rainfall and experiences highest temperature and lowest pressure within the cyclonic system
- The condition at which the eye of the tropical cyclone crosses the land is called ‘Landfall’ of the cyclone
- Average diameter 80-300 km, Speed ranges from 32 to 1800 km/hr
- Movement – normally they move from east to west under the influence of trade winds
- Rainfall – each part of cyclones yields rainfall
These are cyclones that are formed in the mid-latitudes. As they are formed due to movement of air masses and front, they are called as ‘Dynamic cyclone’ and ‘Wave cyclone’. When two different air masses meet each other either on land or oceans and if form fronts, this process is called Frontogenesis. Initially, a cold front is formed where the warm air gets uplifted and it forms cumulonimbus clouds which result in heavy showers and thunders lightning.
Some important characteristics of temperate cyclones:
- Shape – Circular, elliptical or V-shaped
- Average diameter – 1900 km
- Movement – move eastwards with an average velocity of 32 km/hr in summer and 48 km/hr in winter.
These are the pressure region characterised by high pressure in the centre and low pressure at the outer margin. The wind blows outward from the centre, circulating clockwise in the northern hemisphere and anticlockwise in the southern hemisphere. Main properties for the formation of anticyclones are the clear sky, calm air, high temperature in summer and cold in winter.
Some important characteristic of anticyclone are:
- Shape – Circular or V-shape
- Average velocity 30 to 50 km/hr
- They are associated with rainless fair weather
According to IMD (India Meteorological Department), a super cyclone is a strong cyclone that can blow up to 230 km per hour and it will be extremely severe and continues to gain strength.
Condition for the formation of the Super Cyclone:
- Stay of the low-pressure system over warm ocean water.
- The speed of jet stream may influence the formation of the super cyclone.
- Cumulonimbus Clouds: These are very well developed thick clouds which range up to the stratospheric layer and dark in appearance which brings heavy rainfall with thunder and lightning
- A super cyclone is a strong cyclone that can blow up to 230 km per hour
- About 71% of flood-prone areas are in 9 states (Gujarat, Maharastra, Goa, Karnataka, Kerala, Tamil Nadu, Andhra Pradesh, Odisha and West Bengal) and 1 union territory (Pondicherry)
- Some important tropical cyclones are Hurricanes, typhoons, tornadoes
Prelims GS and Mains GS3 (Environment and Ecology)
- It is one of the world’s largest Mangrove forest located in South 24 Parganas and North 24 Parganas districts in West Bengal, which has been named after the Mangrove tree “Sundari”.This provides a unique ecosystem because of its rich wild habitat.
- It is located on the delta of Ganga, Brahmaputra and Meghna rivers and includes three wildlife sanctuaries such as Sunderbans West Wildlife Sanctuary, Sundarbans South Sanctuary and Sundarbans East Sanctuary.
- This forest covers an area nearly 10,000 sqkm and shares its forest resource with India and Bangladesh between the river Baleswar and Harinbanga adjoining with the Bay of Bengal. It has approximately 150 fish species, 270 birds species, 42 mammals, 35 reptiles and 8 amphibians.
- It is one of the UNESCO’S world heritage sites.
- Some important animals in this region – Tigers, Leopards, Rhinoceros, Wild Buffaloes, Wild Hogs, Wild Cats, Barasinga spotted Deer, Hog Deer, Barking Deer, Water Monitor Lizard, Estuarine Crocodile, River Terrapin, Gangetic Dolphins, Olive ridley turtles, Sea turtle, and Monkeys.
- Some important plants in this region- Geoan, Sundari, Matgaran, Keora, Hetal.
Merits of Sunderbans:
- It acts as a protective barrier from climate change, storms, cyclones, floods and intrusions.
- There are a variety of habitats for plant and animal species.
- It also contributes to socio-economic development and livelihood to the local area of people.
- Tigers which present in Sunderbans are Royal Bengal Tigers (Panthera tigris) and its unique habitat makes them differ from rest of the tigers.
- Found in coastal areas flooded by tides of the sea and some are dense and impenetrable
- Trunks of these trees are supported by several roots which grow within the intertidal zone in tropical and subtropical regions.
- These trees have a special adaptation to survive in both salt and freshwater.
- These are also found along the coast of Tamil Nadu in Pichavaram, Muthupet, Ramnad, Gulf of Mannar, Punnakayal and in the coast of Andaman Islands.
Mains GS3 (Disaster Management)
Indian Meteorological Department:
Meteorology had its firm scientific foundation in the 17th century. In 1636, Halley, a British scientist published a treatise on Indian summer monsoon. For studying weather and climate of India, the British East India Company built stations in Calcutta in 1785 and in Chennai in 1796. In 1875, the government of India had established the Indian Meteorological Department. Mr. H. F. Blanford was the first Director-General of the Observatories. India was the first developing country in the world to have its geostationary satellite named INSAT for continuous weather monitoring.
There are six Regional Meteorological centres in India at Mumbai, Chennai, New Delhi, Calcutta, Nagpur and Guwahati. Operational units like Meteorological Centres at the state capital, Forecasting offices, Agrometeorological Advisory Services Centres, Flood Meteorological Offices, Area Warning Centres and Cyclone Warning Centres are under the control of Deputy Director-General. At present IMD is under the Ministry of Earth Sciences.
The main aims of the IMD are to issue a timely forecast, warn against severe weather phenomena in the Northern Indian Ocean region (including the Malacca Straits, the Bay of Bengal, the Arabian Sea and the Persian Gulf), provide climatological information, conduct and promote research in meteorology, and also responsible for seismology.
The reduced concentration of aerosols particle, which created pollutants in the atmosphere that added high sea surface temperature in the Bay of Bengal. When the Amphan cyclone hit the coast of Bay of Bengal, it created serious loss with heavy rainfall, storm surges, and river floods. Since tropical cyclones are most destructive, Amphan cyclone destroyed both West Bengal and Odisha region. The damage due this Amphan cyclone was estimated to be higher in West Bengal. Several parts of West Bengal left behind with uprooted trees, destroyed thousands of homes, also caused the flood and waterlogging on the roads.
After Gonu and Kayrr, Amphan was the third super cyclone formed in the North Indian Ocean. The topography of this region is responsible for the pros and cons in the Eastern Coastal region. It receives enough amounts of rainfall and also frequent cyclones during the south-west monsoon.
Important data – snips on AMPHAN CYCLONE
- A super cyclone is a strong cyclone that can blow up to 230 km per hour.
- About 71% of flood-prone areas are in 9 states (Gujarat, Maharastra, Goa, Karnataka, Kerala, Tamil Nadu, Andhra Pradesh, Orissa and West Bengal) and one union territory (Pondicherry).
- Each year nearly 3 to 5 tropical cyclones occur in the Bay of Bengal and the Arabian Sea.
- Brahmaputra plains descend towards India in a steep flow from Dihang Gorge it enters with the rapid steep and forms the world’s highest discharge river.