Tamil Nadu

Lightning inflicts heavy loss on Kerala every year, says expert

CHENNAI: Kerala ranks high among the States that suffer a substantial loss of lives and damage to equipment in lightning strikes every year, says earth sciences expert S. Murali Das of the Atmospheric Science Division of the Centre for Earth Science Studies (CESS) in Thiruvananthapuram.

Though no cumulative estimates of the financial toll of lightning-induced damage is available, the CESS scientist has estimated the damage caused to BSNL’s fixed line phones during a season of thunder storm activity in the Thiruvananthapuram Short Distance Charging Area (the smallest telecom territorial area) at Rs.2 crore.

He was in Chennai recently to participate in a two-day workshop on lightning protection. Along with Kerala, some of the other States that have been classified by experts as highly ‘lightning-prone’ are West Bengal, Haryana and Himachal Pradesh.

According to Mr. Das, Kerala’s problems with thunder storms originate in the Western Ghats, where atmospheric conditions precipitate convective cloud formations towards the evening.

In contrast, weather phenomena in places like Bangalore produce frontal clouds that can lead to thunder storm activity at any time of the day.

In this southern State, it is a combination of conducive weather patterns, topography features and tall coconut palms that has proved lethal. A pioneering study commissioned by the Union Ministry of Home Affairs to assess the level of risk from lightning strikes in Kerala found that lightning flashes claimed at least 71 lives and injured 112 persons between 1986 and 2002.

“The toll reported in the study is an underestimate of the magnitude of the problem. The source material that comprised newspaper reports and Revenue Department records is by no means comprehensive,” says Mr. Das, who authored the study.

He says that evolving systems for real-time and historical data collection analysis is vital to safety planning across vulnerable sites in the country.

As local weather phenomena cannot be interfered with, safety planning is aimed at scaling down risks, says G.R. Nagabhushana, AICTE Emeritus Fellow, High Voltage Division of the Indian Institute of Science, Bangalore.

Add conducive weather patterns to the low public awareness of lightning protection measures and the toll in terms of loss of human life and damage to property is invariably higher.

A spin-off of damage to electrical and electronic machinery is the downtime when they will be put back into shape.

Experts estimate that roughly 20 per cent of the light-and-sound pyrotechnics across the skyline actually result in a fiery bolt striking the ground.

Modern lightning protection measures include installing air termination systems at homes, commercial complexes and industrial units.

These systems preferentially attract, redirect and dissipate high-voltage lightning beneath the ground. Experts also recommend surge protection devices to buffer power-connected equipment against a pulse of excess voltage.

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