Intense rainfall accounted for nearly 8% of all deaths in Mumbai during the monsoon season in the decade through 2015, according to a paper published on Wednesday in the multidisciplinary science journal, Nature. At 2,300-2,700 deaths per year, the toll was comparable to deaths due to cancer in the city from 2006 till 2015, while people living in slums accounted for 85% of all monsoon-related deaths during this period, the paper said. The paper, titled ‘Rain, Tide, and Lives: The Hidden Mortality Cost of Mumbai’s Monsoon’, was published jointly by researchers from University of Chicago, Princeton University and the city-based Green Globe Consulting.
The researchers mapped data from the Brihanmumbai Municipal Corporation’s death registration system onto the 89 postal zones in the city, classified into slum and non-slum areas. They juxtaposed this information with rainfall data from the municipal corporation’s automatic weather station network, which captures precipitation every 15 minutes, alongside ward-level flooding records, tidal effects and long-term sea-level trends.
The study found that across the 10-year period, rainfall and flooding accounted for 7–8% of all deaths in the city during the monsoon season. Deaths occurred both immediately, through drowning, electrocution and road incidents, and in subsequent weeks, as floods triggered outbreaks of diseases like dengue, diarrhoea and malaria.