Shaoguan, Guangdong Province may face a once-in-50-year flood. What secondary disasters need special attention?
First of all. Secondary disasters refer to disasters induced by primary disasters. Many natural disasters, especially high-grade and high-intensity natural disasters, often induce a series of other disasters, which is the disaster chain. The earliest effective disaster in the disaster chain is called primary disaster, so other disasters caused by primary disasters are called secondary disasters.
Secondary disasters mostly occur in the fields of meteorological disasters and geological disasters, which have the characteristics of concealment and suddenness and are harmful.
So, what disasters will cause secondary disasters that need our attention? First, the earthquake caused secondary disasters.
1, urban secondary disasters after the earthquake
Fire: A strong earthquake will cause severe ground vibration, causing various potential fire sources in the city to cause fires due to overturning, falling and destruction. For example, in the Great Kanto Earthquake in Japan 1932, only 10000 houses collapsed as a direct result of the earthquake, but 700,000 houses were destroyed by fire in the earthquake.
Explosion: Gas tanks and natural gas pipelines in residential buildings were broken due to the earthquake, resulting in leakage and poisoning accidents. Because of the particularity of gas, it will explode when it meets an external open flame, which will not only bring great harm to the surrounding buildings and people, but also bring certain pollution to the surrounding environment.
Toxic substances: toxic and harmful substances stored in enterprises, schools, hospitals and laboratories during the earthquake. It can be leaked due to damaged containers, causing great harm. These substances include phosgene, liquid chlorine, liquid nitrogen, nitrogen oxides, hydrogen sulfide, sulfur dioxide and radioactive substances. For example, during the 1976 Tangshan earthquake, there were 7 gas leaks in Tianjin, and 2 1 person was poisoned, among which 3 people died. 20 1 1 March11The Great East Japan Earthquake triggered a tsunami, which triggered the explosion of the Fukushima nuclear power plant in Japan, causing nuclear leakage and seriously polluting the local and western Pacific ecological environment.
Plague: After the earthquake, the city may also cause secondary disasters such as bacterial pollution and plague.
System damage: After the earthquake, the information storage system was damaged, which is called "memory damage" disaster.
Pollution of landfill sites and tailings ponds: The earthquake caused ground cracks, collapse, water spraying, sand blasting and other ground damage, which easily exposed the garbage originally buried in the depths of the land and caused environmental pollution. In case of rainy weather or urban flood, it is possible to make these garbage float around, corrupt, breed harmful microorganisms and leak toxic and harmful substances.
Damage to buildings and structures: such as house collapse, broken bridge, dam cracking, rail deformation, etc.
Blind shock absorption: when someone jumps off a building during an earthquake, people in public places flock to escape, which can cause casualties such as falling, squeezing and trampling.
Flood: Earthquake will cause secondary disasters such as dam break or landslide blocking the river course.
2. Earthquake secondary disaster site
Mountain collapse, landslide and debris flow are the most serious secondary disasters caused by earthquakes in the field in China at present, and they are also the disasters with the most casualties.
Many experiences show that post-earthquake secondary disasters are often far greater than the losses caused by the earthquake itself. How to prevent secondary hazards?
(1) Flammable, explosive and toxic substances in industrial and mining enterprises should be closely monitored. During an earthquake, once toxic substances or combustible gases overflow, rescue should be organized immediately.
(2) For large reservoirs and dams. , to do a good job of earthquake inspection in advance, found that the problem in a timely manner to reinforce. When an earthquake occurs, residents downstream of the reservoir should pay close attention to the safety of the dam. In case of danger, in addition to organizing rescue, they should also move to a safe place quickly.
(3) There is a big earthquake in the mountainous area, and the river channel may be blocked by landslides. In this case, we should immediately organize personnel to dredge it to avoid flooding.
(4) After receiving the earthquake prediction, evacuate immediately and leave the house as soon as possible. When evacuating people, avoid tall buildings, chimneys, high doors, parapets and high walls. Don't stay in the narrow alley. Avoid high-voltage lines and transformers to prevent electric poles or wires from breaking and getting an electric shock.
(5) In mountainous areas, stay away from steep cliffs, so as not to hurt people when landslides or landslides occur. You should also leave large canals and river banks, which are prone to large-scale ground landslides or collapses. ?
The second is the secondary disasters caused by floods.
Flood will cause environmental pollution, water pollution, food pollution, bacterial growth and so on. And it is easy to cause the spread and prevalence of intestinal infectious diseases such as cholera, typhoid fever and dysentery.
At the same time, it is easy to cause landslides, landslides, mudslides, mountain torrents, urban waterlogging, ground fissures and land subsidence.
Such secondary disasters are delayed. What should we do after the rainstorm?
How to deal with debris flow;
1. If you are indoors when the mudslide occurs, you must find a way to run out of the house and find a safe place to evacuate quickly.
2. Choose the direction perpendicular to the direction of debris flow and climb to the slopes on both sides. Climb as high as possible. The faster you run, the better. Never go downstream of the mudslide.
3. Unload the heavy travel equipment and luggage immediately, and choose a safe path to escape, but the communication tools cannot be discarded, so as to contact the outside world for help.
4. Don't escape to the place where the terrain is empty and the trees grow sparsely. You can choose a nearby area with dense trees to avoid. Dense trees can block the process of debris flow.
5, don't escape to the thick soil, to escape to the hard geological, no gravel, not easy to be washed away by rain rock.
How to deal with the landslide: First, at the top of the landslide, you should escape to the stable areas on both sides of the hillside as quickly as possible. Secondly, when you can't escape in the middle of a landslide, find an open area with a gentle slope to avoid being too close to houses and telephone poles. When it is at the front of the landslide, it can quickly escape to both sides.
Collapse: If it is outside the scope of collapse, you must pay attention to bypass. If you are under the collapsed body, you should quickly hide to both sides; Or feel the ground shaking, you should immediately flee to the flat places on both sides. Don't go into the disaster area to search for property immediately after the disaster.
Urban waterlogging: Shaoguan's once-in-50-year flood is very large. Urban areas are prone to waterlogging, so urban residents should always pay attention to weather information, cut off power supply in time, prevent people from being injured by electric shock caused by stagnant water, and take personal safety precautions.
No matter what kind of geological disaster you encounter, you should first keep calm, don't panic, look around quickly, evacuate to a safer area, leave the accident site as soon as possible, and don't rush back.