Cyclones in India

By: Staff Reporter
In a changing climate scenario the frequency of severe cyclonic storms is increasing in the Indian sub continent. The sub continent with a long coastline of 8041 km is exposed to nearly 10 per cent of the world’s tropical cyclone.
Disaster Events

Tropical cyclones occur in the months of May-June and October-November. The cyclones of severe intensity and frequency in the north Indian Ocean are bi-modal in character, with their primary peak in November and secondary peak in May. There are 8 maritime states along the eastern and western coast of India that have deeply suffered from tropical cyclones.

The Bay of Bengal is a potentially active region for the formation of tropical cyclones. The climatology of cyclone genesis outlined in a study titled ‘Modeling and Data Assimilation for Tropical Cyclone Predictions by Indo-US Science & Technology Forum’, based on 120 years of track and intensity data (1891 – 2010) shows that a total of 606 cyclonic disturbances which include deep depression (DD), cyclonic storm (CS) and severe cyclonic storm (SCS) were formed in the Bay of Bengal. Out of 606 cyclones, 325 (54 per cent) crossed India and as many as 100 (17 per cent) dissipated over the sea without making a landfall. Again with respect to the total number of severe cyclonic storms crossing different countries of the region, out of 197 severe cyclonic storms, 109 (55 per cent) crossed the Indian coast, 47 (24 per cent) to Bangladesh, 23 (11 per cent) to Myanmar, 9 (5 per cent) to Sri Lanka and 9 (5 per cent) dissipated over the ocean without making a landfall.

According to the climatology of cyclone genesis a total of 58 cyclonic disturbances which, formed over the Arabian Sea. Out of these, 53 per cent crossed to India, 9 per cent to Pakistan, 35 per cent to Iran, Arabia and the coast of Africa and 3 per cent dissipated over the sea. According to National Disaster Management Authority (NDMA), Govt. of India, much more cyclones occur in the Bay of Bengal than the Arabian Sea and the ratio is approximately 4:1.

The Super cyclone of the century (OSC99) struck the Odisha coast on October 29, 1999, with an intensity of about 300 kmph accompanied by a 7 meter high storm surge. Out of a total of 30 districts of Odisha state, 11 coastal districts were heavily affected, recording a death toll of more than 10,000 people. However, the worst and oldest cyclone in recorded history of India was in 1737, in Kolkata, that took around 3,00,000 lives.

In a changing climate scenario it is now being understood that the tropical cyclones in the Indian seas is clearly showing a trend – the frequency of severe cyclonic storms is increasing though the occurrence of tropical cyclones remains steady. A significant increase of nearly 46 per cent with a confidence level of 99 per cent is noticed for severe cyclonic storms, while the increase of cyclonic disturbances and cyclones is not statistically significant (Tropical Cyclone Predictions: Eye on the Storm, 2012, Indo-US Science & Technology Forum).

Initiatives and Policies

The Government of India will implement the World Bank-funded National Cyclone Risk Management Project (NCRMP) in Andhra Pradesh and Odisha by 2015, as declared in an official statement by NDMA in September 2012. The Rs. 1400 crore project is aimed at creating physical and non-physical infrastructure to meet emergencies during cyclones. While Rs 758 crore would be spent in Andhra, the rest would be spent in neighbouring Odisha. Of the total amount, Rs. 637.15 crore will be spent on improvement of coastal infrastructure like roads, bridges and 148 multi-purpose cyclone shelters in the nine coastal districts.

In 2004, the World Bank offered to support the NCRMP covering all 13 cyclone prone coastal and islands, states/union territories – Andhra Pradesh, Gujarat, Orissa, West Bengal, Maharashtra, Karnataka, Kerala, Tamil Nadu, Goa, Daman and Diu, Pondicherry, Lakshadweep, and Andaman and Nicobar Islands. The World Bank Mission estimated the overall cost of the proposed NCRMP project (2004-2010) at around 1642.50 crore (365 million USD). World Bank/IDA funding was proposed at Rs 1350 crore.

Figure 1: Major cyclonic circulations over the Indian subcontinent (1996-2012)
Figure 1: Major cyclonic circulations over the Indian subcontinent (1996-2012)

End Note

The Indian subcontinent is one of the worst affected cyclone regions in the world. The subcontinent with a long coastline of 8041 km is exposed to nearly 10 per cent of the world’s tropical cyclones. On an average, five to six tropical cyclones form every year, of which two or three could be severe. Cyclones are characterised by their devastating potential to damage structures; lifeline infrastructure-power and communication towers; hospitals; food storage facilities; roads, bridges and culverts; crops etc. The most fatalities come from storm surges and the torrential rains flooding lowland areas of the coastal territories. For cyclone forecast and advance warning, the Indian government has strengthened the India Meteorological Department (IMD) by providing cyclone Surveillance Radars at Kolkata, Paradeep, Visakhapatnam, Machilipatnam, Madras and Karaikal in the east coast and at Cochin, Goa, Bombay and Bhuj in the west coast. However, with faulty building norms and flouting of coastal regulatory zone laws, cyclone related losses are likely to escalate despite a better warning system in place. The Indian government thus needs to proactively support stringent implementation of laws to save lives and property – and move away from its compensatory model.

Leave a Reply

Your email address will not be published. Required fields are marked *