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Analysis of lightning hazards in India
International Journal of Disaster Risk Reduction 19 (2016) 22–24
Contents lists available at ScienceDirect
International Journal of Disaster Risk Reduction journal homepage: www.elsevier.com/locate/ijdrr
Analysis of lightning hazards in India S. Selvi a,n, S. Rajapandian b a b
Research Scholar, Sathyabama University, Chennai, India Senior Professor, Panimalar Engineering College, Chennai, India
art ic l e i nf o
a b s t r a c t
Article history: Received 5 July 2016 Received in revised form 17 August 2016 Accepted 26 August 2016 Available online 27 August 2016
Out of all unnatural deaths, the most unpredictable is due to lightning. It is clear from the records that in India, thousands of deaths occur every year due to lightning. Such deaths are common in rural areas where most of the victims are farmers. Despite the availability of several guidelines, the safety of people is not assured. The authors have visited various places of lightning attack over the past few years. The majority of deaths in rural places are due to step voltage and touch voltage mechanism. The authors have identified the additional guidelines for protection against step voltage and touch voltage mechanism. & 2016 Elsevier Ltd. All rights reserved.
Keywords: Lightning Hazards Precautions Step Voltage Touch Voltage Safety
1. Introduction In India, the National Crime Records Bureau (NCRB), the information technology division of Ministry of Home Affairs publishes the record of unnatural deaths every year. [1,2]. The existing database has the casualty figures for the various causes attributable to nature and they are Avalanche, Cold and Exposure, Cyclone/tornado, Starvation/thirst, Earthquake, , Epidemic, Flood, Heat Stroke, Landslide, Lightning, Forest Fire, Torrential rains and the rest of the incidents were categorised under other natural causes. For the 14 year period from 2001 to 2014, the total number of deaths attributed to nature are 3,17,259, out of which 9.86% were due to lightning which is shown in Fig. 1. It is very clear from the above figure that deaths due to lightning seem most significant. The average annual death rate is 2234 for the above period. Based on the statistics for gender, the vast majority of lightning victims are male. Males are at a higher risk of being struck and killed by lightning more often than female. During the period 2001–2014, out of 31281 deaths, 71.49% (22,310) of the victims were men and 28.51%(8921) were women. The predominance of male victims is fairly consistent from year to year shown in Fig. 2. The greatest number of deaths occurred between the ages of 15 and 60, with somewhat less in the below 14 and above 60 age category as shown in Fig. 3. The reasons for more number of fatalities in this range is most of the working group people fall under this category. n
Corresponding author.
http://dx.doi.org/10.1016/j.ijdrr.2016.08.021 2212-4209/& 2016 Elsevier Ltd. All rights reserved.
In India the reporting of Lightning deaths is haphazard. Hence these data will not show the entire disaster updates as it is prepared from the media reports on daily basis. The reason for underreporting is that most of the casualty events involve only one person. Therefore, the real number of fatalities and injuries will be much higher than those reported by NCRB. In many developed countries lightning deaths and injuries have reduced. In U.S.A, it is reported that the number of lightning fatalities has decreased from a maximum of over 400 deaths per year early in the 20th century to less than 30 deaths annually in recent years [3,4]. Even today the union government has not recognized and included lightning in the National Natural Disaster list and financial help is not given to the affected families from national relief funds [5,6]. In 2015, after several demands from the state governments the Union government made provision to allow the state government to use up to 10% of the State disaster relief funds to state specific natural disasters [7].
2. Present work The authors have visited 35 places of lightning incidents in South India over the last ten years. The topography of the incident spot and interaction with the witness helped in understanding, the lightning mechanism and how the casualties occurred. Such personal visits to lightning incident will help in developing situational precautionary measures since situational awareness and proper planning is essential to safety. From our observations, most of the fatal accidents in rural places are agricultural related deaths [8], and the causalities are due to Direct hit, Touch voltage and Step
S. Selvi, S. Rajapandian / International Journal of Disaster Risk Reduction 19 (2016) 22–24
23
Fig. 1. Deaths due to various natural disasters in India for the period 2001–2014.
Fig. 4. House where Lightning struck.
Fig. 2. The number of lightning deaths Gender wise from 2001 to 2014.
Fig. 5. Mechanism of Touch voltage.
Only in three cases out of 35, the victims were affected by direct hit. If a person is standing on open area or near any water body if not surrounded by any tall object or structure then the safety measure is to crouch down.
One such case of touch voltage happened on September 29, 2014, when a group of youths from Mela Kooniyoor near Cheranmahadevi, Tamilnadu, India seek shelter in a house [10]. The house is shown in Fig. 4. It was a case of a direct lightning hit on the house and the three boys got killed. The mechanism of touch voltage is depicted in the Fig. 5. The person having contact with the side walls would be subjected to touch voltage and if any other person have physical contact with the first person will also be affected by touch voltage. In developing country like India where Lightning safe structures are not available clear instruction should be given to the people. Even if they happen to find shelter in they should not touch the side walls [11].
2.2. Touch voltage
2.3. Step voltage
Generally, in rural places people are not aware of the danger of Lightning. When there is rain threat, people tend to find shelter under a nearby tree or inside a small hut or shed etc. People, who stand under the tree, are likely to lean on the tree and touch each other. And when lightning strikes the tree, the person having contact with the tree will be affected by the touch voltage and if any other person have physical contact with the first person will also be affected by touch voltage [9]. In the second case casualty occurs when people find shelter inside hut, thatched roof, shed etc. The houses are generally very small. People are likely to touch the side walls and touch each other.
When there is raining threat some poor people who are working in the fields are reluctant to stop the work and find shelter. These people who are working in open fields are more prone to be affected by step voltage. In the Fig. 6. Consider the point P where the lightning current enters the ground. The equipotential lines are shown in Fig. 6. The point ‘a′ and ‘b′ are on different equipotential lines. A person with leg position at point a and a′, b and b′ are safe as they are on the equipotential surface, whereas at point a-b or a′-b′ are unsafe and they will be subjected to step voltage. If there is water body on the ground then the danger prone area is extended up to the end of the water body.
Fig. 3. Number of deaths, Gender and Age wise from 2001 to 2014.
voltage. 2.1. Direct hit
24
S. Selvi, S. Rajapandian / International Journal of Disaster Risk Reduction 19 (2016) 22–24
3. Conclusion
Fig. 6. Mechanism of step voltage.
Though Lightning is the biggest killer, research on lightning and its aftermath has been sporadic in India. The awareness of lightning safety among public is very poor. The authors identified people seek shelter only in case of rain threat and not for lightning. To prevent the causalities due to lightning the education of people especially children, villagers, uneducated people is essential. So there is a urgent need for the Central and State Governments to intervene technically and financially and take steps to conduct lightning awareness program extensively across the country. The government should also provide lightning alerts of an hour or so which would help the people to protect lives. Also, it is evident from the incidents that the people who are working in open areas are bound to accommodate themselves in the nearby available huts and sheds. In such cases they should be instructed not to touch the side walls and touch each other. And. people standing outside are safer if they keep their legs together. The safety measures can be considered inclusion in the existing guidelines.
References
Fig. 7. Leg position of people working in Fields.
In India generally the people working in the fields tend to keep their feet apart and their leg position is shown in Fig. 7. When there is a lightning strike on a tree or any other object on the fields or nearby, the lightning current entering the ground can produce a step volatge across the feet. One such case happened in November 3, 2014 two women agricultural workers were killed and five labourers injured when lightning struck at a paddy field in Mallivakkam near Ponneri in Tiruvallur district, Tamilnadu the lightning had struck a tree in the paddy field[12]. The lightning current flowing through the fields produced a step voltage across their feet. Had kept their feet together they would have been safe [13]. For people working in the fields or open areas, when there is a possibility of lightning threat they should go to a nearby building. If there is no nearby shelter available and if they happen to stay outside then they should keep their feet as close as possible. And if they are not among tall trees or object then is better to crouch down.
[1] 〈http://ncrb.gov.in/〉. [2] 〈https://data.gov.in/catalog/stateut-wise-distribution-accidental-deaths-natur al-causes〉. [3] R.E. López, R.L. Holle, Changes in the number of lightning deaths in the United States during the twentieth century, J. Clim. 11 (1998) 2070–2077. [4] E.B. Curran, R.L. Holle, R.E. Lopez, Lightning Fatalities, Injuries and Damage Reports in the United States, NOAA 1995, pp. 1959–1994. [5] Lightning Risk in India Challenges in Disaster Compensation,Faisel T Illiyas, Keshav Mohan, Shibu K Mani, A P Pradeepkumar, Economic & Political Weekly June 7, 2014 vol XlIX no 23. [6] 〈http://www.thehindu.com/news/national/kerala/drought-management-tobe-part-of-local-planning-process/article6516508.ece〉. [7] 〈http://pib.nic.in/newsite/PrintRelease.aspx?relid ¼115810〉. [8] Ron L Holle (2016) Lightning-cased deaths and injuries related to agriculture' Proceedings of the 24th International Lightning Detection Conference and 6th International Lightning Meteorology Conference, 18–21 April, San Diego, California, USA, 5pp. [9] Martin A. Uman, All about Lightning, 81, Dover Publications, N.Y. 1986, p. 55, ISBN- 2-486-25237. [10] 〈http://www.thehindu.com/todays-paper/lightning-kills-three-injures-ninein-tirunelveli-district/article6455916.ece〉. [11] S. Selvi, S. Rajapandian, Lightning precautions and guidelines to the common man in developing nations like India, Int. J. Appl. Eng. Res. (IJAER) 10 (2) (2015) 3601–3606. [12] 〈http://www.thehindu.com/todays-paper/tp-national/tp-tamilnadu/lightningkills-two-workers-injures-five/article6559233.ece〉. [13] S. Selvi, S. Rajapandian, Step voltage: A major cause for Lightning Casualities, Int. J. Appl. Eng. Res. (IJAER) 10 (12) (2015) 31629–31634.
Contents lists available at ScienceDirect
International Journal of Disaster Risk Reduction journal homepage: www.elsevier.com/locate/ijdrr
Analysis of lightning hazards in India S. Selvi a,n, S. Rajapandian b a b
Research Scholar, Sathyabama University, Chennai, India Senior Professor, Panimalar Engineering College, Chennai, India
art ic l e i nf o
a b s t r a c t
Article history: Received 5 July 2016 Received in revised form 17 August 2016 Accepted 26 August 2016 Available online 27 August 2016
Out of all unnatural deaths, the most unpredictable is due to lightning. It is clear from the records that in India, thousands of deaths occur every year due to lightning. Such deaths are common in rural areas where most of the victims are farmers. Despite the availability of several guidelines, the safety of people is not assured. The authors have visited various places of lightning attack over the past few years. The majority of deaths in rural places are due to step voltage and touch voltage mechanism. The authors have identified the additional guidelines for protection against step voltage and touch voltage mechanism. & 2016 Elsevier Ltd. All rights reserved.
Keywords: Lightning Hazards Precautions Step Voltage Touch Voltage Safety
1. Introduction In India, the National Crime Records Bureau (NCRB), the information technology division of Ministry of Home Affairs publishes the record of unnatural deaths every year. [1,2]. The existing database has the casualty figures for the various causes attributable to nature and they are Avalanche, Cold and Exposure, Cyclone/tornado, Starvation/thirst, Earthquake, , Epidemic, Flood, Heat Stroke, Landslide, Lightning, Forest Fire, Torrential rains and the rest of the incidents were categorised under other natural causes. For the 14 year period from 2001 to 2014, the total number of deaths attributed to nature are 3,17,259, out of which 9.86% were due to lightning which is shown in Fig. 1. It is very clear from the above figure that deaths due to lightning seem most significant. The average annual death rate is 2234 for the above period. Based on the statistics for gender, the vast majority of lightning victims are male. Males are at a higher risk of being struck and killed by lightning more often than female. During the period 2001–2014, out of 31281 deaths, 71.49% (22,310) of the victims were men and 28.51%(8921) were women. The predominance of male victims is fairly consistent from year to year shown in Fig. 2. The greatest number of deaths occurred between the ages of 15 and 60, with somewhat less in the below 14 and above 60 age category as shown in Fig. 3. The reasons for more number of fatalities in this range is most of the working group people fall under this category. n
Corresponding author.
http://dx.doi.org/10.1016/j.ijdrr.2016.08.021 2212-4209/& 2016 Elsevier Ltd. All rights reserved.
In India the reporting of Lightning deaths is haphazard. Hence these data will not show the entire disaster updates as it is prepared from the media reports on daily basis. The reason for underreporting is that most of the casualty events involve only one person. Therefore, the real number of fatalities and injuries will be much higher than those reported by NCRB. In many developed countries lightning deaths and injuries have reduced. In U.S.A, it is reported that the number of lightning fatalities has decreased from a maximum of over 400 deaths per year early in the 20th century to less than 30 deaths annually in recent years [3,4]. Even today the union government has not recognized and included lightning in the National Natural Disaster list and financial help is not given to the affected families from national relief funds [5,6]. In 2015, after several demands from the state governments the Union government made provision to allow the state government to use up to 10% of the State disaster relief funds to state specific natural disasters [7].
2. Present work The authors have visited 35 places of lightning incidents in South India over the last ten years. The topography of the incident spot and interaction with the witness helped in understanding, the lightning mechanism and how the casualties occurred. Such personal visits to lightning incident will help in developing situational precautionary measures since situational awareness and proper planning is essential to safety. From our observations, most of the fatal accidents in rural places are agricultural related deaths [8], and the causalities are due to Direct hit, Touch voltage and Step
S. Selvi, S. Rajapandian / International Journal of Disaster Risk Reduction 19 (2016) 22–24
23
Fig. 1. Deaths due to various natural disasters in India for the period 2001–2014.
Fig. 4. House where Lightning struck.
Fig. 2. The number of lightning deaths Gender wise from 2001 to 2014.
Fig. 5. Mechanism of Touch voltage.
Only in three cases out of 35, the victims were affected by direct hit. If a person is standing on open area or near any water body if not surrounded by any tall object or structure then the safety measure is to crouch down.
One such case of touch voltage happened on September 29, 2014, when a group of youths from Mela Kooniyoor near Cheranmahadevi, Tamilnadu, India seek shelter in a house [10]. The house is shown in Fig. 4. It was a case of a direct lightning hit on the house and the three boys got killed. The mechanism of touch voltage is depicted in the Fig. 5. The person having contact with the side walls would be subjected to touch voltage and if any other person have physical contact with the first person will also be affected by touch voltage. In developing country like India where Lightning safe structures are not available clear instruction should be given to the people. Even if they happen to find shelter in they should not touch the side walls [11].
2.2. Touch voltage
2.3. Step voltage
Generally, in rural places people are not aware of the danger of Lightning. When there is rain threat, people tend to find shelter under a nearby tree or inside a small hut or shed etc. People, who stand under the tree, are likely to lean on the tree and touch each other. And when lightning strikes the tree, the person having contact with the tree will be affected by the touch voltage and if any other person have physical contact with the first person will also be affected by touch voltage [9]. In the second case casualty occurs when people find shelter inside hut, thatched roof, shed etc. The houses are generally very small. People are likely to touch the side walls and touch each other.
When there is raining threat some poor people who are working in the fields are reluctant to stop the work and find shelter. These people who are working in open fields are more prone to be affected by step voltage. In the Fig. 6. Consider the point P where the lightning current enters the ground. The equipotential lines are shown in Fig. 6. The point ‘a′ and ‘b′ are on different equipotential lines. A person with leg position at point a and a′, b and b′ are safe as they are on the equipotential surface, whereas at point a-b or a′-b′ are unsafe and they will be subjected to step voltage. If there is water body on the ground then the danger prone area is extended up to the end of the water body.
Fig. 3. Number of deaths, Gender and Age wise from 2001 to 2014.
voltage. 2.1. Direct hit
24
S. Selvi, S. Rajapandian / International Journal of Disaster Risk Reduction 19 (2016) 22–24
3. Conclusion
Fig. 6. Mechanism of step voltage.
Though Lightning is the biggest killer, research on lightning and its aftermath has been sporadic in India. The awareness of lightning safety among public is very poor. The authors identified people seek shelter only in case of rain threat and not for lightning. To prevent the causalities due to lightning the education of people especially children, villagers, uneducated people is essential. So there is a urgent need for the Central and State Governments to intervene technically and financially and take steps to conduct lightning awareness program extensively across the country. The government should also provide lightning alerts of an hour or so which would help the people to protect lives. Also, it is evident from the incidents that the people who are working in open areas are bound to accommodate themselves in the nearby available huts and sheds. In such cases they should be instructed not to touch the side walls and touch each other. And. people standing outside are safer if they keep their legs together. The safety measures can be considered inclusion in the existing guidelines.
References
Fig. 7. Leg position of people working in Fields.
In India generally the people working in the fields tend to keep their feet apart and their leg position is shown in Fig. 7. When there is a lightning strike on a tree or any other object on the fields or nearby, the lightning current entering the ground can produce a step volatge across the feet. One such case happened in November 3, 2014 two women agricultural workers were killed and five labourers injured when lightning struck at a paddy field in Mallivakkam near Ponneri in Tiruvallur district, Tamilnadu the lightning had struck a tree in the paddy field[12]. The lightning current flowing through the fields produced a step voltage across their feet. Had kept their feet together they would have been safe [13]. For people working in the fields or open areas, when there is a possibility of lightning threat they should go to a nearby building. If there is no nearby shelter available and if they happen to stay outside then they should keep their feet as close as possible. And if they are not among tall trees or object then is better to crouch down.
[1] 〈http://ncrb.gov.in/〉. [2] 〈https://data.gov.in/catalog/stateut-wise-distribution-accidental-deaths-natur al-causes〉. [3] R.E. López, R.L. Holle, Changes in the number of lightning deaths in the United States during the twentieth century, J. Clim. 11 (1998) 2070–2077. [4] E.B. Curran, R.L. Holle, R.E. Lopez, Lightning Fatalities, Injuries and Damage Reports in the United States, NOAA 1995, pp. 1959–1994. [5] Lightning Risk in India Challenges in Disaster Compensation,Faisel T Illiyas, Keshav Mohan, Shibu K Mani, A P Pradeepkumar, Economic & Political Weekly June 7, 2014 vol XlIX no 23. [6] 〈http://www.thehindu.com/news/national/kerala/drought-management-tobe-part-of-local-planning-process/article6516508.ece〉. [7] 〈http://pib.nic.in/newsite/PrintRelease.aspx?relid ¼115810〉. [8] Ron L Holle (2016) Lightning-cased deaths and injuries related to agriculture' Proceedings of the 24th International Lightning Detection Conference and 6th International Lightning Meteorology Conference, 18–21 April, San Diego, California, USA, 5pp. [9] Martin A. Uman, All about Lightning, 81, Dover Publications, N.Y. 1986, p. 55, ISBN- 2-486-25237. [10] 〈http://www.thehindu.com/todays-paper/lightning-kills-three-injures-ninein-tirunelveli-district/article6455916.ece〉. [11] S. Selvi, S. Rajapandian, Lightning precautions and guidelines to the common man in developing nations like India, Int. J. Appl. Eng. Res. (IJAER) 10 (2) (2015) 3601–3606. [12] 〈http://www.thehindu.com/todays-paper/tp-national/tp-tamilnadu/lightningkills-two-workers-injures-five/article6559233.ece〉. [13] S. Selvi, S. Rajapandian, Step voltage: A major cause for Lightning Casualities, Int. J. Appl. Eng. Res. (IJAER) 10 (12) (2015) 31629–31634.