Stay updated with the latest - Click here to follow us on Instagram
It is after 25 years that Gujarat coast is bracing for a cyclone in June. Biparjoy will be only the fifth cyclone of the ‘severe’ (wind speed of 48 – 63 kms/hr) or higher category to cross Gujarat, if realised, as per the forecast issued by the India Meteorological Department (IMD).
Biparjoy is the only third ‘extremely severe’ cyclone to develop in the Arabian Sea in June in 58 years, the data suggested.
The ‘Extremely Severe’ Cyclone Biparjoy (wind speed 90 – 119 kms/hr) is expected to cross Saurashtra-Kutch and Pakistan between Mandvi, Gujarat and Karachi, Pakistan near Jakhau Port in Gujarat by Thursday afternoon as ‘Very Severe’ cyclone with a maximum wind speed of 125 – 135 kms/hr, the IMD has predicted. ” As on 8.30am of Monday, Biporjoy was located 320kms south-southwest of Porbandar,, 360kms south-southwest of Dwaraka, 440kms south of Jakhau Port, 440kms south-southwest of Naliya and 620kms south of Karachi, Pakistan,” the Met department’s latest cyclone update said.
Since 1891, only five cyclones of the ‘severe’ category (wind speed 89 – 117 kms/hr) or above have made a landfall over Gujarat in June, the IMD’s cyclone atlas stated. Notably, all of these were post 1900. These ‘severe’ or higher intensity cyclones were during 1920, 1961, 1964 , 1996 and 1998. Overall, 16 depressions and cyclones, formed in the Arabian Sea during the past 132 years, have reached Gujarat, the IMD’s data stated.
While the naming of cyclones is a more recent initiative, a ‘severe’ cyclone with a maximum wind speed of 100kms/hr had made a landfall close to Diu on June 18, 1996. Another stom, had crossed as an ‘extremely severe’ cyclone with a maximum wind speed of 166kms/hr near Porbandar on June 9, 1998.
What makes cyclone Biparjoy unique is its intensity and pace of movement in the sea since last week. The North Indian Ocean basin reports the maximum cyclogenesis in the months of May and November. June, being the Southwest monsoon onset month, the conditions for the development of cyclones in this basin are generally not conducive. This is mainly due to the dominance of the monsoon wind flow.
Of all the cyclones that emerge in the north Indian Ocean, about 30 per cent are formed in the Arabian Sea and the rest in the Bay of Bengal. One of the reasons is the relatively warmer sea surface waters in the Bay of Bengal that helps the formation of cyclones. Only a fourth of all cyclones in the Arabian Sea move towards the Indian coastline. The rest move northwards towards Pakis-tan or northwestwards towards Iran or Oman.
According to the IMD, the probability for a depression to intensify into a ‘severe’ cyclone or higher in June is about 35 per cent, that too, across the land, the Bay of Bengal and the Arabian Sea put together. Which is why, there have been only two cyclones previously — in 1977 and 1998 — that intensified into the ‘extremely severe’ category with Biparjoy becoming the newest addition to this list.
While India’s eastern coast is highly prone to cyclones, some districts along the west coast — especially in Kerala, Konkan-Goa, north Konkan and Gujarat — too are equally prone to cyclones. But, as the overall number of cyclones formed in the Arabian Sea (average 1) are fewer than those formed in the Bay of Bengal (average 3) in a year, the west coast is less affected.
In India, the IMD has identified 72 coastal districts along with 24 neighbouring districts within the range of 100kms from the coast to be the most vulnerable to cyclones based on the hazard and maximum possible wind, rainfall and other impacts caused by cyclones. These districts are further classified into ‘very highly’ prone (12) , ‘highly’ prone (41), ‘moderately’ prone(30) and ‘less’ prone (13).
Junagadh and Kutch districts of Gujarat are among the ‘highly’ prone category whereas Ahmedabad, Bhavnagar, Amreli, Jamnagar, Anand, Navsari, Surat, Valsad, Bharuch, Porbandar, Rajkot and Vadodara are ‘moderately’ cyclone prone districts. Surendranagar and Kheda and ‘less’ cyclone prone districts of Gujarat. The IMD cyclone data also suggests that, in the past, Gujarat’s Junagadh suffered from four severe cyclones whereas Kutch, Bhavnagar, Porbandar (3 cyclones, each), Amreli and Rajkot (2 cyclones, each) whereas Jamnagar, Ahmedabad, Anand (one cyclone, each).
Anjali Marar works at the Raman Research Institute, Bengaluru.
Stay updated with the latest - Click here to follow us on Instagram