Abdul Wahab Khan
Panaji: According to a fresh climate audit of 100 years comprising monsoon data from 1922 to 2022, the capital city of Panaji has emerged as one of the prominent hotspots of heavy and very heavy rainfall events in India, with higher frequency, greater volume and rising contribution in decadal and annual rainfall variability.
The study, conducted by Pragatika Panda and Sandeep Pattnaik of the Indian Institute of Technology Bhubaneswar (School of Earth, Ocean and Climate Sciences), indicates that Panaji, along with the capital cities of Mumbai, Gangtok and Shillong, now record significantly elevated number of extreme-rain days and larger volumes of rainfall tied to such rain events.
The research was conducted to fill a long-standing gap. “In climate change scenarios, the intensity and frequency of heavy rainfall events (HRE) are on the rise over the Indian region. However, no studies are available to quantify the variability of these HREs across the capital cities of India,” states the study.
Using daily rainfall data from the India Meteorological Department for 100 years for the monsoon months (June to September), the researchers determined frequencies (days per year), volumes (mm³ per decade) and contribution (%) of heavy rain events (64.4-124.4 mm/day) and very heavy rain events (124.4-244.4 mm/day) for each capital city plus their adjoining 100-km radius.
The study confirmed the intensifying nature of monsoon rainfall in these capital cities. While Mumbai and Shillong showed clear positive anomalies in recent decades, Panaji experienced a more moderate but consistent heavy rain event anomalies, indicating that Goa’s monsoon is steadily growing more intense.
In contrast, Chennai and Bengaluru, representing the southern peninsular region, showed the lowest rainfall contributions, minimal variability and largely negative or flat trend anomalies.
In the central-India/southern-peninsular sector, the study shows a heavy rain event mean frequency of about 42.13 days per year for Panaji, the highest among the studied cities. The decadal rise in heavy rain events for the city is given as +13.71 events per decade, while for very heavy rain events, the rise is +5.29 events per decade.
The volumetric contribution in the decades shows Panaji’s heavy rain event contribution reaching about 26.71% in its peak decade. Panaji now records more heavy-rain days, and a rising number of very heavy-rain days, according to the study.
