Hydro- meteorological disasters account for the majority of climate related losses globally. The frequency and intensity of climate extremes have increased under recent climate variability. The coastal regions are particularly vulnerable to climate driven disasters. A study by the Indian Meteorological Department for the period 1891-2007 done in the year 2008 shows that a total of 803 numbers of cyclonic disturbances were documented, showing our vulnerability.
The Bay of Bengal is one of the most cyclone prone regions on earth, where the combination of warm ocean waters, a long coastline, shallow continental shelf, and vast low-lying areas turns tropical storms into deadly disasters. It is worth remembering two cyclones for their catastrophic human and economic toll, namely the 1970 Bhola Cyclone and the 1991 Cyclone Gorky. These events, occurring two decades apart, remain among the deadliest memories, highlighting the extreme destructive power of storm surges in this part of the world.
On November 12, 1970, the Cyclone Bhola made landfall along the coast of Bangladesh, striking during a high tide at night. The storm generated one of the most lethal storm surges in history, with heights reaching up to 35 feet in the worst-affected areas. The surge funnelled into the narrow, shallow Ganges-Brahmaputra-Meghna Delta, inundating flat coastal islands and low-lying tidal flats. Entire villages on islands such as Bhola, Manpura, and Hatia were completely submerged, often drowning residents while they were asleep.
The human toll was staggering. Official estimates place the death toll at least 300,000, with some contemporary reports and survivor accounts suggesting as high as 500,000. The vast majority of fatalities resulted from drowning in the storm surge. In Tazumuddin sub district of Bhola district, more than 45% of the population perished, and some areas lost half or more of their residents. Approximately 85% of homes in the hardest hit coastal zones were destroyed or severely damaged. Fishing communities suffered catastrophic losses. 90% of marine fishermen experienced heavy damage, with around 9,000 offshore fishing boats destroyed and 46,000 onshore fishermen killed. Overall, about 65% of the coastal region’s fishing capacity was wiped out; a devastating blow in an area where fish provided roughly 80% of dietary protein and livelihood support.
Agricultural impacts were equally severe. Vast agricultural areas were flooded with saline water, ruining harvests and salinizing fields for years. An estimated 280,000 cattle were lost, further crippling rural livelihoods. Economic damage was equivalent to several hundred million dollars in today’s terms. Between 4.7 and 4.8 million people were directly affected, with hundreds of thousands rendered homeless.
On April 29, 1991, another Cyclone, Gorky struck near Chittagong with sustained winds exceeding 240 km/h. The storm generated a surge of about 20 feet, inundating coastal areas and offshore islands. The event affected an estimated 13.4 million people across much of Bangladesh’s 57,321 square miles.
The death toll reached at least 138,000, with some estimates as high as 145,000. Most fatalities were from drowning in the surge, though thousands more died in the following weeks from injuries and post-disaster diseases like dysentery, diarrhoea, and infections spread through contaminated water and overcrowded conditions. Nearly 10 million people were left homeless. Over 79,000 buildings were completely destroyed, including more than 9,000 schools and 650 health facilities. Roads, ports, and utilities were heavily damaged, isolating communities and delaying relief.
Agriculture and livelihoods suffered immense losses. Vast rice and grain fields were flooded and salinized, rendering farmland unproductive for years. Nearly three million livestock i.e., cattle, goats, poultry perished, depriving survivors of food, draught power, and income. Fish hatcheries and coastal plantations were devastated completely, causing widespread economic disruption. Offshore islands such as Kutubdia reported 80–90% destruction of homes and near total loss of livestock. Economic damages totalled US$1.5–1.8 billion.
Despite some progress since 1970 including the construction of initial cyclone shelters many people remained in vulnerable mud huts or waited too long to evacuate, amplifying the human cost.
Both cyclones demonstrated the destructive power of storm surges in the Bay of Bengal causing rapid inundation of low-lying, densely populated deltas during high tide, leading to mass drowning, destruction of fragile housing, and collapse of fishing and farming economies. Bhola’s higher death toll (300,000–500,000 vs. 138,000–145,000) reflected near-total absence of warnings, shelters, and communication infrastructure in 1970. Gorky, while still catastrophic, showed marginally lower mortality in some areas where early shelters were used by about two million people.
Both events caused long term environmental and economic damage like salinization of farmland, loss of livestock and fishing capacity, and disruption of food security and agriculture dependent communities. Post storm disease outbreaks added thousands to the toll in 1991, while Bhola’s survivors faced prolonged hunger and loss of livelihoods.
The sheer scale of these disasters underscores several enduring realities. The storm surges, not winds, are the primary killer in the Bay of Bengal, especially when coinciding with high tides and funnelled into shallow deltas. Low-lying coastal populations with limited sturdy housing and economic dependence on fishing and agriculture face disproportionate risk. Small increases in cyclone intensity produce nonlinear, dramatic surges as shown by cyclone Bhola. The absence of timely warnings, shelters, and evacuation infrastructure turns manageable storms into humanitarian catastrophes.
These two tragedies remain stark reminders of nature’s destructive potential in one of the world’s most vulnerable regions. Their impacts caused hundreds of thousands dead, millions displaced, economies shattered. These catastrophes continue to mobilise global efforts to protect coastal communities facing intensifying tropical cyclones in a changing climate.
Bishnupada Sethi, IAS
The author serves as the Chairman of the Odisha Forest Development Corporation (OFDC) and continues as the Chief Administrator of the KBK districts.
