Lightning: The New Natural Disaster
Now-a-days, one of the most discussed issues of the country is about the increased number of death from lightning and thunderstorm. According to the Department of Disaster Management (DDM), at least 80 people have been killed by lightning up until just May 13, with more occurring later this year. At least 635 people were killed between 2010 and 2015. (Source: The Daily Star report, published on May 14, 2016).
On the other hand, Comprehensive Disaster Management Programme (CDMP) of the Ministry of Disaster Management and Relief of the Government says that a total of 180 people were killed this year due to thunderstorm (Source: Prothom Alo report, published on September 06, 2016). Apart from these, within this month, lightning killed around 25 in Tangail, Sunamganj, Kishoreganj, Dinajpur, Chapainawabganj and Manikganj. The actual number is believed to be much higher, since many incidents go unreported.
Earlier, in Bangladesh, thunder was not regarded as a natural disaster. But considering the massive death toll this year, the Government has recently announced it as a natural disaster so that if anyone dies from a lighting strike, his/her family will recieve 20 thousand takas from the Government.
But have we ever thought of the reasons behind such incidents? Is there anything wrong in our climate?
When the temperature rises, hot moist air rises upwards-- known as updrafts. At the same time, the cool air sinks downwards, and this is called downdrafts.
“The collision of updrafts and downdrafts creates cumulonimbus (storm cells with electric charge) and it produces lightning and thunder”, states Dr. Dilara Zahid, Assistant Professor, Institute of Disaster Management and Vulnerability Studies, University of Dhaka. “Usually it happens during summer, in the months between March and May, but as the world temperature is rising day by day, such collisions occur every now and then”, she adds.
Other than the rising temperature in the atmosphere, there is another specific reason. In prior times, we had many tall, old trees, most of which have been cut down over the years. As we know, trees are electricity resistant; they can absorb lightning strikes and save us. But due to massive deforestation, we are rapidly losing our forests. Besides, the increased use of metallic devices is one more reason for lightning to reach humans easily, as metals also conduct electricity.
Previously, lightning was rarely taken as seriously as it is taken today. But given the rise in the death toll in the past few years, the DDM has added a few steps in its latest amendment of Standing Orders on Disaster (SOD). Also, the Institute of Disaster Management and Vulnerability Studies, University of Dhaka has arranged a workshop in July this year with the Government on how to create awareness to protect people from lightning strikes. The panel came up with two effective ways-- non- structural and structural.
“The structural way is using 'Lightning Arrestor' both in residential and high rise industrial buildings, so that the current is diverted through the arrestor, in most cases, to earth”, says Professor Dr. Dilara Zahid. “And it is mentioned in the Bangladesh National Building Code (BNBC)”, she adds. Besides, the old buildings, which have no such device to protect from against lightning, should be brought under a retrofitting system.
The non-structural way is to create awareness among the people. It is very tough to develop warnings to protect lightning, as we know that the volt of lightning is very high (in some cases 30-50 lakh volts) and it comes at 220 kilometres per second. Yet, some quick steps can be effective in this regard. After seeing the flash, if we can manage a safe shelter within 30 seconds, we'll be able to protect ourselves. We should keep in mind that, we must avoid tall trees, open fields, boating, fishing, metal wires, electronic equipment, wire fences, water pipes, inflammable materials, corded phones, concrete floor or walls, and utility poles. Apart from these, unplugging expensive electronic equipment and securing outdoor objects that could explode or cause damage is a wise decision.
Though it is not so easy to manage protection from such a quick hazard, but the above mentioned precautions can help to a great extent.