(LD Online) – When lightning, lightning running zigzag accompanied by continuous rumbling thunder, fierce wind blowing and pouring rain make us a particularly deep impression.
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| Automatic meteorological measuring device |
THE Phenomenon of Thunderstorms, whirlwinds, lightning, hail in Lam Dong
A thunderstorm is an electrical discharge in the atmosphere in the form of lightning accompanied by thunder. Along with whirlwinds, hail often occurs in thunderstorms. Hail is defined as precipitation in hard form in the form of stones, lumps or ice crystals that fall to the buffer surface (ground, water surface, vegetation, ...) from the mass of cumulus clouds or colossal clouds.
In practice, hail usually occurs only in strong thunderstorms and is accompanied by intense showers of relatively short duration. The shape and size of water pellets frozen in hail are often very different, the most common are spheres, cones, convex lenses, polyhedrons and a few other deformed shapes; diameter from about 0,5mm to 20 - 30mm; from a few grams to several hundred grams. Hail usually only occurs when there is a thunderstorm, but not every thunderstorm has hail. The frequency of hail in a thunderstorm is only about 10%. Hail falls in the atmosphere at a very high speed and increases in proportion to the size and weight of the stone, ranging from 30 to 60 m/s, in particular, up to 90 m/s. At such speeds, ice cubes falling on objects or vegetation always leave traces and cause noises comparable to that of a train or heavy truck, or a crawler vehicle crossing a bridge.
Hail is a dangerous weather phenomenon. Hailstorms lasting for several minutes or more can significantly damage crops, partially or completely lose crops, affect structures, buildings, and transport vehicles, causing injury or death to livestock, poultry and sometimes even humans; especially hail has affected the operation of civil aviation, threatening the safety of flights. The phenomena of thunderstorms, whirlwinds, lightning and hail that have occurred in Lam Dong province in the past 10 years are as follows:
(1) Around 14:30 pm on May 07, 5 in the area of Tran Quang Khai Street, Ward 2013, Da Lat City, Lam Dong, hail occurred on a large scale, damaging dozens of vegetable gardens, greenhouse flowers...
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| Many people in Da Lat witnessed hail for the first time |
(2) On July 3, 7, in wards 2021, 9 and 11 of Da Lat city, hail occurred, damaging many areas of people's crops. Around 12pm on July 14, 4, in Ka Do and Lac Xuan communes, Don Duong district, a huge hailstorm accompanied by a tornado damaged dozens of hectares of farmers' crops. Many farmers said that this was the largest hailstorm in more than 7 years. The hailstorm lasted about 2021 minutes with stones nearly 20 cm in diameter and a dense amount of ice that damaged many crops of the people of Ka Do commune.
(3) On March 21, 3, a tornado took about 2021 minutes to blow off the roofs of dozens of houses, causing serious damage. On the morning of March 10, according to initial information, a tornado damaged 22 houses in Tan Thuong commune (Di Linh district) and injured 3 people; Lightning struck 70 person dead in Da Huoai district, and caused a power outage for many hours in this locality
(4) In 2022, Lam Dong province has experienced 04/22 types of natural disasters (heavy rain, hail, tornadoes, lightning strikes), including 12 heavy rains, 02 hailstorms, 07 heavy rains with tornadoes, 01 lightning strike causing damage to property and people's lives, specifically: natural disasters have caused 01 death, 07 injuries; 172 houses damaged, 441 ha of crops, 0,8 ha of fish ponds drifted, 6,7 ha of greenhouse greenhouses damaged; damaged 02 bridges, 01 car and 02 motorbikes; damaged 04 schools… Total damage is estimated at 13 billion VND. (Source of People's Committee of Lam Dong province).
Lam Dong is one of the areas where thunderstorms are relatively high compared to other neighboring areas. According to statistics, an average of 70 to 80 days of thunderstorms occur every year. Thunderstorms appear most in the season change period, which is the end of the dry season and the beginning of the rainy season (from the end of March to the end of May), this is the period under the influence of the fighting between different air masses causing very strong atmospheric instability, combined with topographical conditions and in this period also often appear hail accompanied by strong winds.
MEASURES IN THE PERIOD OF PURCHASING
Currently is the period of changing seasons, the weather is volatile, it is a period of many thunderstorms accompanied by thunder and strong winds, sometimes with hail. These are dangerous weather phenomena that appear and cause damage quickly and unexpectedly, and it is difficult to accurately predict the time of occurrence, the affected area and the degree of harm.
In the current condition, rain forecasting is still limited, so we need to regularly monitor and update the forecast and warning bulletins of dangerous weather phenomena broadcast on the mass media in the region, combined with passive prevention measures based on statistical results, investigate to identify areas where hail often occurs, so that the plants can be planted, which are less affected by hail, or are less affected by the epidemic. fruit and harvest at the safest time; promptly cover, cover to limit the devastating extent of hail, ...
According to the local Hydrometeorological Station, the weather in Lam Dong province from now until the end of May and early June is still mainly: "Light rain in some places at night, cloudy days with sunny weather, showers and thunderstorms in the afternoon and afternoon." Therefore, all levels, branches, authorities and local people need to pay attention to prevent and take initiative in taking measures to limit damage such as supporting buildings, observing safety principles when using and operating electrical and electronic machinery and equipment used in production and daily life; implement appropriate methods to protect crops, protect crops, and note some ways to prevent thunderstorms as follows:
1. Places of residence, places with works, buildings, places where machinery and equipment, electric poles, antennas, chimneys are located, places often crowded with people such as schools, markets, hospitals, offices, high-rise buildings, etc., must have a lightning protection system, which is a lightning rod. The Lightning Column can be built into a separate column close to the building or it can be attached to the highest place of the building with an iron bar with a pointed tip placed vertically towards the sky; an electrical conductor with one end connected to an iron rod and the other end of the wire tied to a metal foil that is split into many branches buried deep into the ground. The higher the lightning rod, the greater its protection range. The protected space is a circle with the center at the base of the column and the radius equal to the height of the column. Items inside this circle are protected from lightning strikes.
2. When grazing cattle or doing production work in the uplands, in the fields, or walking on the street where there is no lightning protection system, and seeing a thunderstorm coming, it is necessary to quickly find a way to disperse the livestock; If you leave your tools at work, go quickly to the house or not close to home, then find a quiet place on low ground, far from electricity poles, away from metal objects, away from places with water surface such as ponds, lakes, etc., waiting for the storm to pass. Do not move (including traveling in private means of transport); absolutely do not hide under the largest trees, especially those standing alone in the middle of the field, under piles of straw, bunches of rice, where there are high mounds.
3. When there is a thunderstorm, it is important to cut off power to power-consuming machinery and tools, leaving only the things that are really necessary; completely cut off power to electronic devices, unplug the antenna wire from the TV and switch to the ground wire (all antennas need to be grounded like a lightning system); should not make phone calls, turn off the chimneys, close the doors to prevent moisture from entering the house; I don't go barefoot, I should wear thick, dry sandals...
4. When being struck by lightning, it is necessary to receive emergency first aid according to the following regulations: Let the victim lie on the wet ground, loosen the clothes to make it easier to breathe; Mix 5 grams of Bicarbonate salt with 300ml of water for the victim to drink slowly. If the victim is found to have severe signs of shortness of breath, unknown heart rate, it is necessary to do artificial respiration, support the heart by massaging or punching hard on the chest area. And finally, quickly find a way to call an ambulance in time to take the victim to the hospital.
5. In the current conditions, rain forecasting is still limited, so we need to regularly monitor and update the bulletins of Forecast and Warning of dangerous weather phenomena broadcast on the mass media in the area, combined with passive prevention measures based on statistical results, investigate and identify areas where hail often occurs, so as to arrange crops that are less affected by hail, or are less susceptible to disease, to grow crops that are less affected by rain, results and harvest at the safest time; promptly cover and cover to limit the destruction of hail.
