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Lightning-thunderstorms, flash floods bring horror and misery to the homeless and poorly housed of South Africa

By Michelle Simon - 19 Mar 2011 7:55:0 GMT
Electron Bolt Lightning Science

South Africa: Lightning-thunderstorms have become a horror factor in South Africa with many rural villages, urban squatter settlements and those without shelter (homeless, street-kids) exposed to the natural elements. In addition, to the spring-to-summer-to-early autumn (Southern Hemisphere) flash rains flooding many shack settlements causing a huge disaster management problem displacing shack-dwellers, lightning increasingly becomes a critical risk factor. In the KwaZulu-Natal Province alone, the death-toll due to lightning storms since November 2010 reached 19.

Case Studies

Urban

Saturday, 12th March 2011, In Soweto, a 13-year-old boy was killed and twelve other boys were injured when a bolt of lightning struck the soccer field.

Rural

Wednesday, 9th March 2011, in the rural village of Mhlwazini, a mother and her four young children were inside their rondavel (traditional mud round hut with a thatched roof) when a loud bang was heard followed by a fire to the thatched roof. In a hut not far away another life was

taken when lightning struck the traditional structure. 2011 started off for some families with lightning torture, when out in the Pongolo rural area, seven lives were lost when lightning struck a marquee and another seven (including very young children) in the town of Eshowe. In the

Msintsini village, Eastern Cape Province, a man was struck by a bolt of lightning while walking home. His friend who was walking alongside him survived unscathed. In November 2010, in rural iNtuthuko, seven people were killed, in Mpumaze another seven lives were lost and in Pongola

forty people were injured when lightning struck a local creche; in rural Maratshu a 17 and 18- year-old boy were playing soccer when they were struck dead by lightning and a 70-year-old woman was killed after being struck by lightning sitting in the entrance of her hut, four people

were killed in Port St John's when they were struck by lightning; and in rural Qwasa, an eight- year-old boy was herding cattle was killed by lightning.

In all the cases, with the exception of the pedestrian and the open field, the poor have suffered the brunt of the lightning bolts. The main reason being a lack of proper formalised shelters and lightning conductors on traditional structures, both an unaffordable necessity. Provincial government in KwaZulu-Natal (KZN) in January 2011, called for a lightning probe to understand the causes of lightning strikes. While this is necessary, there has been decades of information explaining this, coupled with the socio-economic inequities, the vulnerability of the poor to lightning is more than obvious. What is needed is action, providing formal shelter to the poor, lightning conductors on traditional homesteads and an education process so that people in all areas, urban, rural, the poor, the rich follow lightning safety procedures as they would in a fire drill, namely, avoid walking out in a lightning storm, avoid using electrical and appliances, and do not play in an open field. However, credit must be given to the start-up efforts of government in trying to address the problem at a minimalist level, households in lightning-prone provinces are to be given 800 lightning conductors, 800 solar lights, 800 solar radios and 800 oil lamps. That's a start but let's move onto addressing the poverty, unemployment and homeless problem simultaneously. Does that meet the needs of all exposed?

Lightning Protection

Metallic conductors can be used to protect a structure by intercepting and diverting the lightning current into the ground as harmlessly as possible. When lightning is likely to occur, people are advised to stay indoors or in a car, away from open doors and windows, and to avoid contact with any electrical appliances or plumbing that might be exposed to the outside environment.

How is lightning formed?

Lightning is created when excess positive and negative charges form within cloud, with a greater portion of positive charges occupying the upper structure of the cloud and a smaller portion of positive charge settling in the lower zone of the cloud. The large negative charge centralises in the

cloud.

Recipe for Making Lightning:

  • Cloud ice - a key ingredient, the more the better.
  • Moisture
  • Instability
  • Cold front to cause the air to rise.

Lightning is then created in four pathways:

  • Within a cloud - intracloud.
  • Between the cloud and the atmosphere.
  • Between clouds - intercloud.
  • Between the cloud and the Earth's surface.

Intracloud lightning is the most common and appears as channels of light emanating from a central point. Cloud-to-ground lightning is less common but more dangerous.

Lightning Bolts - Ground Impacts

A channel of electrically charged air molecules are created, the first stroke (leader stroke) is created and directed downward. The negatively charged stepped leader is invisible to the human eye, and moves in steps in less than a second toward the ground. The ground (Earth's surface) is positively charged, the channel is negatively charged and the two oppositely charged polarities meet about 30 metres (100 ft) above the ground. The electrical transfer in this channel creates lightning. This meeting point connects the cloud to the ground forming a return stroke of lightning, a spectacular bright flash with temperatures as high as 30,000 °C (50,000 °F). As the differences in charges continue to increase, positively charged particles rise up taller objects such as trees, buildings, houses, telephone poles, etc. The entire process is very rapid; the leader stroke reaches the ground in about 30 milliseconds, and the return stroke reaches the centre of the cloud in about 100 microseconds. Though the bolt appears continuous, it is actually a series of short bursts. Most lightning strikes occur in less than a half second and the bolt is usually less than 2 inches in diameter. Not all stepped leader lightning is negatively charged. Positive charged lightning can be and seems to be more dangerous as it may strike before or after the thunderstorm and has a longer duration. Positive lightning also carries high electrical current and therefore ignites fires.

Humans also conduct electricity and electricity passes through us, moving upward. The health impacts are either severe death or fatal injury, for example, heart failure, respiratory failure, multi- system failure, coma, brain damage, haemorrhages or severe burns.

It is hoped that the South African government has a more holistic plan to address disaster impacts to the poor in the range that includes lightning, basic shelter, basic survival resources (water, energy efficient services), floods, disease and an overall quality of life.