Dear experts, I am in urgent need of information about severe weather. The more the better, thank you. . .

There are more than 20 kinds of meteorological disasters, mainly including the following types:

(1) Heavy rain: flash floods, river flooding, urban water accumulation;

(2 ) Rain and waterlogging: waterlogging and waterlogging;

(3) Drought: drought in agriculture, forestry, and grasslands, water shortage in industry, cities, and rural areas;

(4) Hot and dry wind: Drought winds, foehn winds;

(5) High temperatures, heat waves: extreme heat, human diseases, burns, and ripening of crops;

(6) Tropical cyclones: strong winds, heavy rains, floods ;

(7) Cold damage: damage to crops, livestock, and fruit trees due to strong cooling and low temperatures;

(8) Freeze damage: frost, freezing damage to crops, livestock, and freezing of water pipes and oil pipes Bad;

(9) Freezing rain: electric wires, tree branches, and roads freeze;

(10) Icing: rivers, lakes, and seas freeze, and roads freeze after rain and snow;< /p>

(11) Snow damage: blizzard, snow;

(12) Hail damage: damage crops, damage to houses;

(13) Wind damage: fallen trees, House flipping, overturning of cars and boats;

(14) Tornado: local devastating disaster;

(15) Lightning: lightning casualties;

(16) Continuous rain (Rain): adverse to crop growth and development, food mildew, etc.;

(17) Dense fog: human diseases, traffic obstruction;

(18) Low-altitude wind shear: ( Plane) Aviation crash;

(19) Acid rain: Damage to crops, etc.

A review of disastrous weather in my country

my country is located in the southeastern part of Eurasia and borders the Pacific Ocean. Most areas have a monsoon climate. In winter, it is mainly controlled by polar continental air masses or modified polar air masses, with northwest, north, and northeasterly winds prevailing; while in summer, it is controlled by tropical and subtropical oceanic air masses and continental air masses, with southwest, south, and southeasterly winds prevailing. Against this background, meteorological elements such as precipitation, temperature, wind, and clouds in my country are highly variable and often sudden, resulting in a variety of meteorological disasters.

There are many types of meteorological disasters that affect our country, with high intensity and frequency, causing serious losses. With the growth of economic development and social wealth, the losses caused by meteorological disasters are increasing. Accurate weather forecast is one of the most important scientific basis for government departments at all levels to direct disaster prevention and response. According to statistics over the years, among various types of meteorological disasters, floods cause the heaviest losses, while droughts affect the widest area. In addition, there are tropical cyclone disasters, cold wave and strong cold air disasters, sandstorm disasters, wind disasters, hail disasters, frost disasters and snow disasters, etc. These disasters affect a wide area and are often related to anomalies in large-scale weather systems, which also dominate the occurrence of smaller-scale weather disasters.

Changes in my country's large-scale weather systems are closely linked to the East Asian monsoon. The flood season from May to September every year is a period of frequent disastrous weather in my country, and the large-scale precipitation distribution and drought and flood disasters during this period are largely controlled by the summer monsoon. After the onset of the summer monsoon, my country's main rain belts started from South China and gradually advanced northward with the progression of the summer monsoon. The activity of the main rainy belts varies from year to year due to differences in the strength of the monsoon, the speed at which it advances northward, and the length of time the monsoon rainbands stay in one place. The formation of regional heavy rains in my country's history is closely related to the changes in the East Asian summer monsoon; the low-altitude southerly airflow of the summer monsoon not only transports energy and water vapor to the rainstorm areas, stimulating and maintaining heavy rains, but can also cut off the cold air in mid- and high latitudes and cause rain belts in my country. Continuous drought in other areas; at the same time, it is the background condition for the formation of mesoscale strong convective weather disasters.

The East Asian monsoon airflow is the result of the interaction of large-scale weather systems that are members of the entire East Asian monsoon circulation system. Among them, the western Pacific subtropical high plays a particularly important role in my country's weather and climate. This subtropical high is located in the middle troposphere of the Northern Hemisphere over the western Pacific. In summer, there is the Meiyu front to the north and the East Asian tropical monsoon circulation to the south. It is not only directly related to the establishment of the South China Sea summer monsoon, but its northward jump and advance and retreat are closely linked to the changes in the subtropical summer monsoon and its rain belts in my country's mainland. It is the direct cause of the large-scale weather phases in my country. Generally speaking, the position of the subtropical high determines the position of my country's main rain belts, and its strength and stability determine the overall situation of droughts and floods in my country's flood season. Therefore, the study of the movement patterns and mechanisms of the western Pacific subtropical high is a crucial scientific issue.

An important system closely related to the western Pacific subtropical high is the South Asian high. It is a powerful and stable center of atmospheric activity in the upper troposphere and lower stratosphere in southern Asia in summer, and is also an important member of the global subtropical high pressure belt. Although the impact of the upper-level circulation system on precipitation distribution is not as direct as that of the low-level system, compared with the low-level circulation, the upper-level circulation system anomalies are more stable and sustainable, and have a certain advance. Therefore, it is closely related to the northern hemisphere atmospheric circulation in summer and my country's The relationship between weather and climate cannot be ignored.

The tropical weather systems that directly affect our country’s weather are mainly tropical cyclones. Tropical cyclones land in my country every year and cause disasters of varying degrees.

In addition to its own structural characteristics, the path and intensity of tropical cyclones also depend to a large extent on the activities of subtropical high pressure and cold air. At the same time, the activity of tropical cyclones also has a counterproductive effect on the activity of subtropical high pressure.

Another aspect that determines the weather characteristics of East Asia is the weather system in mid- and high-latitudes. During the winter monsoon, tropical and subtropical systems basically withdraw from mainland my country, and the high-altitude westerly troughs and ridges and the corresponding low-level high and low pressure systems completely control my country. Even during the summer monsoon, they still control the northern part of our country and have an important impact on the weather in the south. For example, most of the heavy rains in our country are directly or indirectly related to cold air activities. Compared with the mobile westerly band fluctuations, the East Asian blocking high pressure is of particular importance to the weather in East Asia. The blocking situation is a typical manifestation of persistent abnormal atmospheric circulation. Its formation, maintenance and collapse not only affect the weather anomalies in the region, but also cause changes in the atmospheric circulation in the northern hemisphere. Research and forecasting practice have shown that the blocking situation in Asia, especially in East Asia, is the main circulation background for persistent droughts and floods in summer in my country. The extremely large or relatively large flood years that occurred in the Yangtze River Basin in my country (1954, 1969, 1980, 1983, 1993, 1996) are almost all related to the establishment and maintenance of the congestion situation in East Asia. The establishment and collapse of the blocking situation in East Asia and the Pacific in winter and spring are closely related to the outbreak of cold waves, especially strong cold waves, in my country, and are also related to sand and dust weather in northern my country. Therefore, the blocking situation is extremely important in the large-scale system that affects weather changes in my country.

Among the various natural disasters that occur every year in our country, meteorological disasters account for more than 70%. Every year, more than 500 million acres of farmland are affected by various meteorological disasters, and nearly 600 million people are affected by major meteorological disasters such as drought, heavy rain, floods, and typhoons. Since the 1990s, my country's average annual direct economic losses caused by meteorological disasters have reached 200 billion yuan, accounting for 3%-6% of that year's GDP. As the economy continues to grow and the population increases, its absolute value will further increase.

Divided according to the degree of losses caused by meteorological disasters, my country's meteorological disasters are arranged as follows: floods, typhoons, droughts, cold damage, hail, thunderstorms, strong winds, dry and hot winds in the northern winter wheat area, lightning strikes, and fires. In addition, snowstorms in pastoral areas, floods on the Yellow River, fog in cities and highways, and sandstorms in northern areas also caused a large number of human and animal casualties and economic losses.

Flood disaster refers to the abnormal rise of water level due to meteorological and other reasons, breaking through embankments, submerging fields and houses, drowning people and animals, and causing diseases and other disasters. Floods have always posed a huge threat to humans and other living things throughout history. According to statistics, my country's average annual flood losses in the 1990s were as high as 120 billion yuan, accounting for 2.4% of the gross national product. Floods in the Yangtze River and Huaihe River in 1991, floods in the Pearl River in 1994, and floods in the Yangtze River, Songhua River, and Nen River in 1998 all caused huge economic losses to the country. In 1998, 29 provinces (autonomous regions and municipalities directly under the Central Government) across the country suffered from floods of varying degrees. According to statistics from various provinces, 4,150 people died and direct economic losses were 255.1 billion yuan (Ministry of Water Resources of the People's Republic of China and the People's Republic of China, 1999). Flood disasters have become an important constraint on my country's economic development.

Typhoons (including tropical storms, severe tropical storms and typhoons) refer to tropical cyclones with average winds near the center of level 8 or greater. The strong winds caused by typhoons can overturn ships, destroy houses and other facilities, huge waves can break through sea walls, and heavy rain can trigger flash floods. Typhoon disasters are fierce and have acute and sudden characteristics. Our country is the country hardest hit by typhoons in the world, with an average of 7 typhoons landing every year. The average annual economic loss caused by typhoons in mainland my country alone reaches 24.6 billion yuan, and the death toll is as high as 570.

Drought disaster refers to disasters such as withering of crops and insufficient drinking water for humans and animals due to long periods of clear weather without rain or little rain, lack of water in the soil, and dry air. Considering weather conditions, drought also includes hot and dry winds, high temperatures and heat waves. In the past 40 years, the average area of ​​farmland affected by drought in our country has reached more than 300 million acres every year, causing disasters of 110 million acres, and reducing grain production by tens of billions of kilograms. In the 1990s, droughts occurred frequently in northern my country, and six large-scale severe droughts have occurred in the Central Plains. From February to May 2001, most areas in northern my country experienced the longest, most widespread, and most severe drought disaster in the past 10 years. The area of ​​farmland affected by drought across the country reached 341 million acres, and 15.8 million people and 11.4 million large livestock suffered temporary drinking water difficulties.

A cold wave is a surge of extremely cold air like a tide, commonly known as a "cold wave". When strong cold air from polar or high latitude areas rapidly advances to mid- and low-latitude areas, causing severe cooling in a large area, and is often accompanied by comprehensive disastrous weather phenomena such as strong winds, sand dust, snow (rain) and freezing damage, it is called A cold wave is a large-scale disastrous weather that has a serious impact on our country. There are an average of 5 to 6 cold waves that affect our country every year, and they can occur in autumn, winter, and spring from September of the current year to May of the following year.

Hail is solid precipitation formed by condensation of water vapor in the air. It is a spherical or cone-shaped object with alternating transparent and opaque layers. Hail mainly occurs in mountainous areas and foothills from May to September, with a range of only a few kilometers to dozens of kilometers, and is obviously localized and dispersed.

It is a serious meteorological disaster. A short and violent hailstorm can cause crop failure, withered fruit leaves, destroyed pastures, and casualties of people and animals, thus seriously affecting the agricultural economy and farmers' income.

Sandstorms refer to weather phenomena in which strong winds blow up large amounts of dust and sand from the ground, causing horizontal visibility to be less than 1 km. The frequent sandstorms that occur every spring in northern my country not only cause major natural disasters there, but also seriously harm Beijing, Tianjin and other places, and spread to the whole country. Strong sandstorms can cause house collapse, interrupt transportation and power supply, induce fires, cause casualties of people and animals, pollute the natural environment, destroy crop growth, and cause serious losses and great harm to the national economic construction and the safety of people's lives and property. The sand and dust weather process with the largest scope, strongest intensity, most serious impact, and longest duration since the 1990s occurred from March 18 to 21, 2002 alone, attacking more than 1.4 million square kilometers of land in northern my country. The affected population amounted to 130 million yuan, and the direct losses amounted to more than 1 billion yuan.

Adverse meteorological conditions may also lead to the occurrence of a variety of other secondary or derivative disasters, such as large-scale heavy rainfall and floods, which can trigger debris flows and landslides in specific areas of mountainous areas. In certain areas (especially Mountainous towns), short-term concentrated outbreaks and long-term accumulation of high-density meteorological and geological disasters (mudslides, landslides) seriously threaten people's lives and property safety. In recent years, the frequency of debris flow and landslide disasters and the number of deaths have increased significantly; continuous rainfall or sustained high temperature and drought will also promote the outbreak of large-scale pests and diseases. Therefore, meteorological disasters are important primary disaster systems.

In short, with the development of my country's social economy, the losses caused by meteorological disasters, especially severe disastrous weather, will become more serious, and disaster prevention and reduction will have higher and higher requirements for meteorological services. Disastrous weather is small in scope, strong in intensity and fierce, and often appears in marginal areas. Although all parties are paying great attention to it, it is difficult for the existing conventional meteorological observation network to catch its traces in a timely manner relying on traditional technical means. , it is more difficult to make accurate local weather forecasts in advance. To provide disastrous weather warning and forecasting services, we must first develop remote sensing technology that can conduct continuous observations and have high spatiotemporal density, and strengthen the construction of a comprehensive observation system. The construction and development and application of my country's new generation weather radar station network, mainly Doppler weather radar, will provide extremely effective monitoring, warning and short-term nowcasting services for my country's disastrous weather, especially medium- and small-scale disastrous weather. Tools and information.