Do you know these "fatal" dangers by the sea?

Summer has come, and the seaside has become a "resort" for people to play. However, there are many drowning accidents at the seaside every year. Here, I have sorted out seven "risk factors" of the seaside for everyone. I hope everyone can put the safety principle first and always "sound the alarm".

1. High-temperature sunburn: Don't apply cool oil to skin with redness and swelling.

Swimming at the seaside is a good way to cool off the heat, but the reflectivity of the beach and water surface to the sun light is very high, so you are at the seaside, even if the sun is not very strong, there is a great risk of sunburn. And direct exposure to ultraviolet rays, no shadow, stay in this environment for a few hours, the skin cooled by water will distract your attention to the skin, and cold water can also alleviate the feeling of sunburn, thus masking the early warning signal of sunburn. Many people find that there is a terrible "abnormality" in their skin after landing or even waking up the next day.

If the skin is allergic and red after sun exposure, it needs timely treatment. The correct way is to wash the skin surface with cold water (not seawater), which is the best way to reduce local fever and pain, or apply a wet towel to the sunburned area. In addition, it is not suitable to use ordinary cleaning products after sunburn. When cleaning the skin, it is best to use weakly acidic cleaning products that meet the pH value of the skin so as not to irritate the skin. Of course, if there are more serious phenomena such as peeling, please go to the hospital in time to avoid more serious situations.

2. Bury the bunker: the high tide is easy to sink in.

Besides swimming, playing with sand on the beach by the sea is a favorite pastime for many children. After all, it is unrealistic for children under the age of ten to swim in the sea, and burying themselves in the sand seems to be a very interesting entertainment. However, compared with swimming in the water, burying sand on the shore is also full of danger! Because sand is loose without water, people can easily loosen it in sand, but once the sand enters the water, the situation will be different immediately. Water will fill the gaps between the sands, and the sands will "suck away" people buried in the sands-this is also the main reason why people will be buried in the sands when the sea water rises.

If you must play with sand, there are several points to pay attention to: First, observe the slope of the beach and the distance to the beach, not below the sea level, and not too close to the beach; Second, we should always pay attention to the change of sea level, pay attention to the fluctuation of sea water, and remember to produce sand as soon as the high tide is found.

3. Surge: It is advisable to stay away from big waves.

As the saying goes, "big waves wash sand", Su Dongpo saw this scene at the seaside thousands of years ago, and he was deeply touched and wrote a famous sentence through the ages. However, in real life, the "big waves scouring sand" is not a good thing. Because when the sea is stormy, huge waves can often directly throw people into the sea, and it is also easy to knock over ships that are sightseeing at sea. If the weather conditions are bad, the chances of survival are even smaller. According to statistics, typhoon is the main cause of disastrous waves in China.

In fact, it is not difficult to avoid the waves. The most important thing is to pay attention to the weather forecast. When the weather conditions are bad, try not to get close to the seaside, and try to choose a regular bathing place with someone on duty to avoid challenging dangerous places such as cliffs. Some beaches can also observe the semaphore on the beach. Blue means that this sea area can be safely played. Orange or yellow indicates that the sea conditions of the day are not suitable for swimming. If it is red, it means that it is forbidden to play in the water in this sea area.

4. Water quality: Some seawater is not "blue"

Water quality is the abbreviation of water quality, which indicates the physical, chemical and biological characteristics and composition of water. In the impression of many people, the endless blue sea is water quality, but this situation may only appear in tourist attractions such as Thailand and Maldives, and many coastal areas in China are also important industrial towns, such as Jinshan Petrochemical near Jinshan Bay. Inadvertently, a large number of pollutants enter the ocean and destroy the water quality in coastal areas.

According to a survey data, as far as China is concerned, the water quality in Bohai Bay and Pearl River Estuary is poor, while the water quality in Changjiang Estuary, Hangzhou Bay and Minjiang Estuary is extremely poor. In addition, the problem of algae in seawater is also worthy of attention. The proliferation of harmful algae is usually brightly colored, which is called "red tide". They can produce toxins and cause human diseases. Nowadays, "red tide" has appeared in lakes and oceans all over the world, which has become a very serious problem. The reproduction of harmful algae can irritate eyes and nose, causing stomach problems or more serious nervous system reactions.

5. Marine life: The "cross talk" around is highly toxic.

On the beach, many people may have seen a blue balloon-shaped object, which looks not low in value, but can't be touched, because it is a highly toxic "jellyfish" and the "jellyfish" is very toxic. Anyone who is stung will have a horrible wound like "flogging" and it will last for a long time. Of course, many people were stung while swimming. Also wandering around are jellyfish: after being bitten by sand jellyfish and jellyfish, erythema, blood rash, itching and burning pain will appear at the wound. Sensitive patients may have wheal, erythema, edema, ecchymosis, blisters and even epidermal necrosis. In particular, patients with allergic constitution may have acute edema, and if they are not rescued in time, they will die in a short time.

Don't be too flustered if you are accidentally stung by jellyfish or jellyfish. You can wipe the wound with a dry towel or other mild clothes in one direction to remove the venom adsorbed on the skin. If the sting bag is large, you should find tools to scrape it off in time. Secondly, wash the sting with seawater (white vinegar can also be used) on site. Remember never to use fresh water, because fresh water will accelerate the release of venom from stinging cells. Of course, the most important thing is to go to the hospital in time and seek professional treatment.

If jellyfish and jellyfish are common "recidivists" and we can always avoid touching them, it will be difficult for swimmers to really grasp the situation of other creatures in the ocean after they really get into the water. Speaking of dangerous and horrible creatures in the ocean, almost everyone will recall the fear dominated by the classic movie Jaws, and the great white shark in it conforms to anyone's horror fantasy. Of course, there are not many chances to meet sharks in the sea, and it is very difficult to see sharks in the coastal areas of China. If you really meet a shark, don't panic, because sharks generally don't take the initiative to invade humans without wounds on their bodies.

However, other marine creatures such as stingrays and sea urchins do not have the "consciousness" of sharks. For example, stingrays avoid crowded places, but they often hide in sand holes. Once they step on the waves in shallow water, the sharp barbs on their tails will immediately pierce your skin and cause serious reactions. Sea urchins have spikes and contain toxins, which can cause painful reactions. Stone fish often disguise themselves, and once they sense danger, the thorns on their backs will stand up and release venom. So it's better to avoid these creatures.

6.rip current: a hidden and dangerous invisible killer

The drowning of a pair of twin girls in Qingdao made "rip current" instantly become a "celebrity vocabulary on the Internet", but this secret and dangerous killer has always existed. Rip current, the scientific name of cleavage, which is the fault tide we see when playing in the sea, is a narrow and strong current like a light beam. The velocity is mostly 0.3- 1 m/s, the fastest is 3 m/s, its length is 30- 100 m or even longer, and its flow direction is almost perpendicular to the coastline. Its horror is that the tearing flow can quickly bring floating objects or swimmers to deep water.

The speed of typical rip flow is about 2m/s, which is faster than the swimming speed of ordinary people. Even lifeguards are often dragged out to sea by it during training. Therefore, it is very important to master the correct escape method. In case of rapids, never swim against the current to the shore, because this will only accelerate physical exertion. The correct way is to swim vertically along the coast. Or you can go with the flow until you reach the end of rip current, swim along the coast for a while, and finally turn around and swim back to the shore.

7. Tsunami: It is very harmful and difficult to predict.

Tsunami is a powerful destructive wave, which may be caused by geological activities such as underwater earthquake, volcanic eruption or underwater collapse and landslide. The tsunami in Indonesia in 2004 impressed everyone and killed more than 200,000 people. Although the tsunami wave is only a few meters or even centimeters high, the destructive power of this "water array" is very great because it is hundreds of kilometers wide. For example, a 2-meter-high tsunami will instantly destroy wooden houses; After the tsunami wave is 20 meters high, it is difficult for reinforced concrete buildings to compete. As far as the current forecasting technology is concerned, tsunami forecasting is often very difficult.

Although tsunami is not a common disaster, we should not take it lightly. Earthquake is the "Depth Charge" of tsunami. There is a time difference between the arrival of earthquake waves and tsunamis, which is just conducive to people's prevention. If you feel a strong vibration, don't go near the mouth of the sea and rivers. In addition, if you find that the tide fluctuates suddenly and abnormally, the sea level drops obviously or there are huge waves, and a large number of blisters emerge, you should leave the shore as soon as possible. When the sea water receded abnormally before the tsunami, many marine animals such as fish and shrimp were often left in the shallows, and the scene was spectacular. Don't pick up fish or go sightseeing at this time. You should leave the coast quickly and move to the inland highlands. ■

This article comes from: Beijing Science and Technology News