What are the hazards of lightning? What are the hazards of lightning

Lightning is one of the 10 most serious natural disasters announced by the United Nations, and it is also one of the top 10 natural disasters in China. Since the 80s of the 20th century, with the wide application of electronic information systems in the production, life and work of residents, the losses caused by lightning disasters have become more and more serious. There are 21 provinces, autonomous regions and municipalities in China with thunderstorm days of more than 50 days, and the maximum number of thunderstorm days can reach 134 days.

Thunderstorms in China are mainly concentrated from June to August every year. Every year, three to four thousand people are struck by lightning**, causing property losses of 5 billion to 10 billion yuan.

Lightning usually strikes the spire of the tallest object outdoors, so isolated tall trees or buildings are often the most susceptible to lightning strikes.

1. Tip discharge and lightning rod.

Under the action of a strong electric field, near the place where the curvature of the object is large (such as a sharp, small tip, and a place where the bending is very strong), the isopotential plane is dense, and the intensity of the electric field increases dramatically, resulting in the ionization of the air here and the gas discharge phenomenon is generated, which is called corona discharge. Tip discharge is a type of corona discharge, which refers to the phenomenon of gas discharge caused by ionization of air near the tip.

When a thundercloud passes over, the middle and lower part of the cloud is a strong negative charge center, and the underlying surface under the cloud is a positive charge center, so a strong electric field is formed between the cloud and the ground. In the vicinity of the tip of the ground protrusion such as building spires, trees, hilltop grass, woods, rocks, etc., the isopotential plane will be dense, where the electric field is extremely strong, and the air is ionized, thus forming a tip discharge from the surface to the atmosphere.

The lightning rod is a lightning protection device composed of a metal rod (flash receiver) standing on the roof of a building, a metal down conductor and a metal grounding body. Its function is to attract lightning that may hit the building to it and enter the ground to protect the building. Further research is needed on the mechanism of why lightning rods can protect against lightning.

It is believed that the tip of the lightning rod discharges, neutralizes the charge accumulated in the thunderstorm cloud, and plays a role in eliminating electricity. But in recent years, by calculating the amount of discharge at the tip, it is far from being able to neutralize all charges.

2. Human lightning protection.

People who are outdoors when thunder and lightning are thundering and lightning should follow four principles in order to protect against lightning strikes.

One is that the human body should lower itself as much as possible so as not to be directly hit by lightning as a protruding tip.

Second, the contact surface between the human body and the ground should be reduced as much as possible to prevent damage caused by "step voltage". The so-called stepping voltage is near the lightning strike point, a large potential difference between the two points, if the two feet of the person are very separated, respectively contact the two points far apart, then the two feet will form a large potential difference, there is a strong current through the human body to cause people to be injured.

Third, do not go under isolated trees and near tall buildings without lightning protection devices, and do not hold metal bodies high above your head.

Fourth, do not enter the water, because the water body conducts electricity well and is easy to be struck by lightning. In general, you should go to a lower place and stand or crouch with your feet together to reduce the chance of encountering lightning.

If you are indoors during the lightning period, do not go near the window, as far away as possible from the electric lights, **, the lead of the outdoor antenna, etc.; In buildings without lightning protection devices, contact with chimneys, water pipes, heating pipes, steel columns, etc. should be avoided.

3. Top 10 methods of outdoor lightning protection.

The following rules should be observed outdoors

1) Fire and **. The high-temperature arc, secondary discharge, huge lightning current, and ball lightning intrusion of direct lightning discharge can directly lead to disasters and mines; Impulse voltage breakdown of insulation and other damage to electrical equipment can indirectly lead to disasters and damage.

2) Electric shock. Cumulus clouds can directly electrocute people by discharging electricity, secondary discharge, ball lightning strike, and lightning current to the human body. Electrical equipment insulation damaged by lightning strikes can also cause people to be electrocuted.

3) Destruction of equipment and facilities. The high voltages and currents generated by lightning strikes can cause damage to important electrical installations, buildings and other facilities.

4) Large-scale power outages. Large-scale power outages can occur when power equipment or power lines are damaged.

Lightning damage is attribute damage, and unlike ordinary damage, it can trigger the chain of iron cables, and has a defense-breaking effect on vine armor. The thunder attribute cards are thunder kill and lightning, and the generals who can cause thunder attribute damage are, Zhang Jiao, Zhang Liang, God Liu Bei and so on.

The hazards of lightning are generally divided into two categories: first, the thermal effect and electrodynamic effect of lightning directly hitting people or buildings; The second is the secondary effect of lightning, that is, the electrostatic induction and electromagnetic induction generated by the lightning current.

There are 6 specific hazards of lightning as follows:

1. The high-voltage effect of lightning current will produce an impulse voltage of up to tens of thousands of volts or even hundreds of thousands of volts, and such a huge voltage will instantly impact electrical equipment, which is enough to break down the insulation and cause a short circuit in the equipment, resulting in direct disasters such as combustion and **.

2. The high thermal effect of lightning current will release a strong current of tens to thousands of amperes, and produce a large amount of heat energy, and the heat at the lightning strike point will be very high, which can lead to metal melting, causing fire and **.

3. The mechanical effect of lightning current is mainly manifested in the phenomenon of **, distortion, collapse, tearing and other phenomena of the lightning struck object, resulting in property loss and personnel **.

4. The electrostatic induction of lightning current can make the conductor of the hit object induce a large number of charges contrary to the nature of lightning, and when the lightning disappears and is too late to disperse, it will produce a very high voltage discharge phenomenon resulting in fire.

5. The electromagnetic induction of lightning current will produce a strong alternating electromagnetic field around the lightning strike point, and the current generated by the induction can cause local overheating of the transformer and cause fire.

6. The intrusion of lightning waves and the counterattack of high voltage on the lightning protection device on the building will also cause the power distribution device or electrical line to be broken and burn and cause fire.

The hazards of lightning are: personnel, destroying buildings, power supply and distribution systems, communication equipment, causing forest fires, causing computer information system interruption, storage, oil refineries, oil fields, etc.

More than 2 3 victims of lightning were attacked outdoors. Two of them out of every 3 people survived. Eighty-five per cent of those killed by lightning were women, ranging in age from 10 to 35. Most of the deceased took refuge in thunderstorms under trees.

Thunderstorm weather lightning protection recommendations:

1. Stay indoors and close doors and windows, and those who work outdoors should take refuge in buildings.

2. Reduce the use of ** and mobile phones.

3. It is not advisable to use televisions, stereos and other electrical appliances without lightning protection measures or insufficient lightning protection measures, and it is not suitable to use faucets. 44. It is not advisable to enter temporary shantytowns, sentry boxes or low-rise buildings without lightning protection facilities.

5. Do not touch antennas, water pipes, barbed wire, metal doors and windows, building exterior walls, and stay away from live equipment such as wires or other similar metal devices.

6. Do not stand on the top of a mountain, the roof of a building or close to an object with high conductivity.

7. Do not dispose of flammable materials contained in open containers.

8. Do not swim or engage in other water sports or activities, should not play outdoor ball games, in case of thunder and lightning, immediately leave the water and other open venues, and find a place to hide.

9. When it is impossible to hide in a building with lightning protection facilities in the wilderness, you should stay away from trees and masts.

10. It is not advisable to play umbrellas, hoes, shovels, badminton rackets, golf clubs, etc. on your shoulders in an open field.

1. The hazards of lightning are: personnel, destroying buildings, power supply and distribution systems, communication equipment, causing forest fires, causing computer information system interruption, storage, oil refineries, oil fields, etc.

2. More than 2 3 of the victims of lightning were attacked outdoors. Two out of every 3 of them survived. Eighty-five per cent of those killed by lightning were women, mostly between the ages of 10 and 35. Most of the deceased took refuge in thunderstorms under trees.

Thunder is an atmospheric phenomenon.

Thunder is caused by the friction of positive and negative charges between clouds and clouds in the atmosphere to produce violent discharge, produce high temperatures, make the atmosphere expand sharply, and produce a deafening loud sound, which is lightning and thunder.

When atmospheric charges are constantly accumulating in the clouds. If the amount of charge becomes strong enough, lightning will occur. When lightning crosses the sky, it can quickly warm up the air along its path.

The heated air expanded rapidly and slammed into all directions as violently as it had happened. This creates a huge sound wave, which we sound like thunder.

The most common lightning is linear thunder, the most dangerous to guess the charge of the great judgment, sometimes you can also see the sheet thunder, and there will also be ** spherical thunder spikes. In the discharge area, the current can reach hundreds of kiloamperes and the voltage can reach millions of volts, and the destructive force is very huge, such as touching trees or houses, it will be knocked down, and touching people and animals will be electrocuted or scorched, causing disasters.