Thunderstorm is undoubtedly one of the most beautiful forms of nature. Beautiful in the sense that such a scene is not visible to the human eye all the time of the year. Only at the beginning of the season with the onset of monsoon do we see the thunderstorms. The roar of thunder and the dazzling spark in the sky give the message of drizzle. Just when the dry nature of winter behaves harshly, the rain comes with thunder. Although this thunderbolt has become a cause of panic lately, it is quite enjoyable for many. Many people startled and laughed when they heard the call of lightning which suddenly illuminated the world covered with thick black clouds.
On August 4, 2021, 17 people, including 5 women, were killed in a lightning strike while going to a Pakka area of the adjoining Shibganj upazila for a wedding ceremony at a ghat house on the banks of Padma river in Sadar upazila of Chapainawabganj district. When it started to rain heavily, they took refuge in a tin-shed house at the dock and died at the spot. At that time, this tragic accident of lightning caused a great stir in the whole country. Moreover, the locals left their food and drink to prevent the theft of the bodies of those killed in the lightning strike and started burying the graves with rod cement. When someone dies in a lightning strike, that corpse becomes a precious object. The media reported that the villagers had taken this initiative out of the fear that the bodies of those killed in lightning strikes would be stolen from the country.
However, the number of deaths due to thunderstorm is increasing at present. News of such deaths is often heard in different parts of the country. In the four months from March to June 2021, 177 people were killed in lightning strikes across the country. At least 47 people were injured at the same time. Chapainawabganj, Jamalapur, Netrokona and Chittagong were the worst hit. However, Sirajganj has already been identified as a hotspot of thunderstorm. On the other hand, from January 2020 to April 30, 79 people were killed in lightning strikes across the country, out of these, 10 are women, 3 are children and 68 are men. In these four months, 21 people have been injured in thunderstorm.
According to a study conducted on thunderstorm, three types of lightning strikes occurred in Bangladesh in 2015-2020. From one cloud to another cloud or inter-cloud, from one place of the same cloud to another place or inner cloud and from cloud to earth. At that time the total amount of those three types of lightning was 55 million(. Their daily and seasonal occurrences differ again. For example, the highest number of thunderstorms in 24 hours is between 8-10 pm, 12 percent. On the other hand, there is also a difference in the type of lightning in the seasonal pattern. About 59 percent of lightning strikes during March to May, and 31 percent during the monsoon season, from June to September. However, about 70 percent of the total thunderstorms occur from April to June. In the two months before the onset of monsoon in Bangladesh, the incidence of lightning in Sylhet, Sunamganj and Moulvibazar is much higher than other districts. Rangamati, Sunamganj and Chittagong are the first three districts to experience lightning during monsoon. In winter, Khulna, Satkhira, Bagerhat and Rangamati, Chittagong and Bandarban have the highest number of thunderstorms during the monsoon season.
Analysis of the causes of lightning shows that when the surface water evaporates, water vapor collides with the heavier part of the cloud at the bottom. As a result, many water particles lose their electrons and become positively charged and many water particles receive those electrons and become negatively charged. The discharge process usually takes place in three ways, namely -a) between the positive and negative charges of the same cloud, b) the positive charge of one cloud with the negative charge of another cloud, again with the negative charge of that cloud with the negative charge of that cloud and c) between the positive charge of the cloud and the ground i.e. it is called cloud to ground discharging. When this charged water vapor turns into a cloud, a huge amount of static electricity is generated in the cloud. At this point the relatively light positive charge is above the cloud and the relatively heavy negative charge is below. The discharge process begins when the amount of these two opposite charges in the cloud is sufficient. Discharging causes an electric spark to flow through the air. The flow of this electric spark is 'thunderstorm'. But not all lightning strikes, only cloud-to-ground discharges cause lightning to fall to the surface. '
The light we see during a thunderstorm is basically an intense glow of energy radiated from the ionized atom of this narrow channel. During the formation of these narrow, ionized and electrically conductive channels, the air temperature rises to about 27,000 ° C and the pressure rises to about 10-100 times. But this whole thing happens in a fraction of a thousandth of a second. This change causes the surrounding air to expand like an explosion at high speed. This produces loud noises and this is the sound we hear and see as the sound of lightning. Climate change is thought to be caused by climate change, a decrease in the number of tall trees, an increase in the number of black clouds in the sky, an increase in the number of frictions in the clouds, and an increase in global temperatures. The higher the temperature, the higher the thunderstorm. If the temperature rises by an average of one degree, thunderstorms are expected to increase by 10 percent or more. Nowadays clouds flow as a result of friction between clouds or the upper and lower parts of dense black clouds flow as two pools. This causes lightning to strike. As the density of black clouds has increased in recent years, the amount of lightning has increased as the amount of sudden rainfall has increased. Electric current flows through the human body much like an electric shock. In the same way that people are shocked when lightning strikes, people are also shocked and killed by lightning. Because the human body is electrically conductive. Due to this people are struck by lightning. If there is no electrically conductive substance like lightning in an open space and if there are people whose height is higher than other electrical conductors then lightning strikes people. Lightning does not usually occur directly on the ground. Lightning strikes the conductor. Then the electricity of the lightning mixes with the soil through that conductor. Tall trees, buildings, and mountain tops are usually more prone to thunderstorms. Lightning strikes also occur on lightning rods installed in homes.
Lightning is an accident that is extremely difficult to prevent. If (lightning) happens then many people may die. In our country, the incidence of lightning usually occurs from April to June. It is important to take some precautions to avoid such death and injury in lightning. These are- 1) Thunderstorms usually last 30-35 minutes. Stay at home during this time. If you need to go out of the house in case of emergency, wear rubber shoes, it will protect you from thunderstorms. 2) If you are in a paddy field or open field during a thunderstorm, you have to sit down with the weight on your toes and fingers on your ears. 3) If there is a risk of lightning, take shelter under a building or concrete tent as soon as possible. Do not go on the roof of the building or on the high ground. 4) The child should be kept away from any kind of sports during lightning, should be kept indoors. 5) If there are tall plants, electric poles, metal objects or mobile towers in the empty space, do not stay near it. It is dangerous to be under a tree during a thunderstorm. 6) You should not go fishing in a boat without a tent during a thunderstorm. If you are in the sea or river, you have to stop fishing and take shelter under the boat tent. 7) If someone is inside the car, then the body can not be connected to the metal part of the car. 8) If you are on the roof of the house or on a high place, you have to get down from there quickly and go to a safe place. If you see thick (storm) clouds during the season, be careful and take shelter in a safe place before the onset of rain. 9) Wear rubber sandals on the feet and refrain from touching water and any metal objects such as stair or balcony railings, water taps etc. 10) Electrical conductors should be away from any object. It is not safe to stay in a pond or pond. 11) In case of lightning, it is better to keep the electronics of the house which are disconnected from the electrical connection or DIS. Even if they are closed, you have to refrain from touching them.
The treatment of people injured by lightning is similar to the treatment of people injured by electric shock. Effective measures must be taken to quickly remove electrical charges from the body. Need to massage the body. The injured person should be taken to the medical center immediately without being disturbed by the abnormal behavior. There is no substitute for awareness to be safe from lightning and to reduce the damage caused by lightning, public and private initiatives should be taken to plant tall palm trees in a large number of open spaces or fields.
Md Zillur Rahaman is a Banker and Columnist.