What are the top ten natural disasters on earth?

Drought, flood, typhoon, storm surge, freezing injury, hail disaster, tsunami, earthquake, volcano, landslide, debris flow, etc.

In fact, it is not reasonable to make it into the top ten.

Natural variations on the earth, including those induced by human activities, occur all the time. When this mutation brings harm to human society, it constitutes a natural disaster. Because it has brought different degrees of damage to human production and life, including the relationship between man and nature through labor and the interpersonal relationship related to it. Disasters are negative or destructive. Therefore, natural disasters are a manifestation of the contradiction between man and nature, with the dual attributes of nature and society, and are one of the most severe challenges faced by mankind in the past, present and future.

The main sudden natural disasters in the world are: drought, flood, typhoon, storm surge, freezing injury, hail, tsunami, earthquake, volcano, landslide, debris flow, forest fire, agricultural and forestry diseases and insect pests, etc.

Flood is a flood caused by excessive rainfall or intensity (rainstorm or rainstorm), which causes rivers to burst their banks, flash floods, flooded fields, destroyed buildings and casualties. In China, floods are frequent and intense, especially in the middle and lower reaches of the Yangtze River, the Huanghuaihai River, the lower reaches of the Liaohe River and South China. April to September is the flood control period of major rivers every year, and the state has to spend a lot of money on flood control measures. In recent 30 years, the most serious flood disaster in China occurred in Zhumadian, Henan Province from August 5 to 7 1975, and the maximum rainfall in three days reached 1605 mm (the average rainfall in this area for many years was 800 mm). Torrential rain triggered flash floods, which caused the earth dams of two reservoirs to burst and flooded farmland1130,000 hectares. 199 1 in the summer of, a large-scale flood disaster in the Jianghuai area became a major disaster at home and abroad, with direct economic losses exceeding 50 billion yuan.

Drought. A long drought brings rain. Meteorological disasters with high temperature, continuous lack of rain or no rain. At the beginning of its appearance, people could not feel its arrival, but the longer it took, the larger and more serious the drought-affected area became. China suffers from drought all the year round, and spring drought occurs frequently, seriously and for a long time in most areas. The occurrence of drought is not only relatively concentrated in time series. For example, among the 170 droughts that occurred in Beijing during 1470- 1949,10/5 droughts occurred year after year. In addition, it appears in large numbers in space. For example, in the spring of 1950, droughts occurred in most parts of Inner Mongolia, Hexi Corridor in Gansu, northern Hebei and northwestern Shaanxi, and droughts occurred in large areas in the Yangtze River, Huaihe River, Yellow River and Hanshui River basins from July to September. 1950- 1980.

Tropical cyclone is a low-pressure atmospheric vortex originating from the tropical ocean surface. According to the wind power near its center, it is divided into four grades: tropical depression 6-7, tropical storm 8-9, strong tropical storm10 ~1,typhoon 12 and above. In the tropical western Pacific, 30 typhoons are generated every year (accounting for 38% of the world), and the peak of typhoon activity is in July-August. After the formation of the tropical ocean surface, it moves to the northwest, with an average of 7 typhoons landing on the coast of China every year. Typhoon brings strong winds, heavy rains (80% of the highest rainfall record in China's coastal 15 provinces is caused by typhoon), huge waves and tidal disasters, which seriously threaten people's lives and property.

The above-mentioned1August, 975, the catastrophic flood disaster in Henan Province was caused by the landing of Typhoon No.7503, which slowed down the inland movement of deep people and kept the low pressure. The typhoon landed in Taiwan Province and Zhejiang successively. Heavy rain occurred in Fujian, Guangdong, Hunan, Jiangxi, Hebei, Henan and other provinces 10. Among them, Henan is the most serious, with the rainstorm area accounting for one-third of the whole province, and the maximum rainfall 1/ hour189.5mm, 24/ hour1.066,5438+0.8mm, which caused a rare flood disaster in a century.

The so-called tidal disaster refers to the fact that under the action of strong storms, offshore storm surges and huge waves are superimposed on the astronomical climax in flood season, and the tide exceeds the local warning water level, destroying defense facilities, leading to flooding and forming tidal disasters. Tidal disasters in China are mainly caused by typhoons and cold waves. The southeast coast was hit by typhoon, which is an area with frequent and repeated tidal disasters. In the Bohai Sea and the northern part of the Yellow River, cold waves and cold fronts pass through in winter and spring, resulting in a strong northeast wind of magnitude 7 or above in the Bohai Sea and a tidal disaster in the south bank of the Bohai Sea.

Low temperature chilling injury is a sharp cooling caused by strong cold wave in the process of crop growth and development. Including the low temperature in summer in Northeast China, freezing rain in winter in South China and low temperature hazards around the cold dew season. Late rice in the middle and lower reaches of the Yangtze River and South China is heading and flowering. In this kind of weather, the empty shell of rice will shrink, resulting in reduced production. 1969 65438+1From October 26th to 30th, the cold wave reached the Yangtze River valley, and the temperature dropped 14 ~ 20℃, causing severe freezing damage to winter wheat, rape and fruit trees. 1977 65438+1From October 25 to 29, the cold wave caused the snow in Inner Mongolia and Xinjiang to be 0.5 meters deep, the grasslands were buried, and a large number of livestock died.

Earthquakes are modern crustal activities caused by dynamic action inside the earth, which are generally divided into tectonic earthquakes (95%), volcanic earthquakes and subsidence earthquakes. The reason why China has become the most serious earthquake area in the world is strongly related to the modern crustal activity in China, which is located at the intersection of the Pacific Rim tectonic belt and the Mediterranean Himalayan tectonic belt. Except for Zhejiang and Guizhou provinces, earthquakes of magnitude 6 or above have occurred in all provinces. 1556 65438+123, the M8 earthquake occurred in hua county, Shaanxi Province. "It was an earthquake in Shanxi, Shaanxi and Henan Province at the same time. Thunder rumbled, chickens and dogs barked ... or the spring burst, or the veranda houses were trapped underground, or the hills stood out on the ground ... killing 820,000 officials, soldiers and soldiers. 1976, an industrial town with a population of one million, was in ruins in an instant, ranking first in the world's most destructive 10 earthquake in the last century.

Earthquake is inevitable, and earthquake prediction is still a difficult problem in the world. China has made great progress in the field of medium and long-term prediction, but only a few people can make accurate predictions, and efforts are still needed to predict this difficult impending earthquake.

Landslide is a large number of rock and soil bodies on the slope, which slides down a certain sliding surface under the action of gravity, resulting in the destruction or burial of farmland and buildings above and below the slope, resulting in casualties. Due to the differences between natural conditions and human factors, there are various types of landslides. China is a mountainous and earthquake-prone country. Landslides caused by heavy rains and earthquakes have occurred from time to time in history. With the development of construction, reservoirs appear constantly. Mining, cutting and landslides in mountain cities. 1933 During the Diexi earthquake in Maowen County, Sichuan Province on August 25th, 30 miles around the mountain collapsed and landslide occurred. Diexi City and two giant high-speed landslides in Longchi Mountain fell opposite each other, blocking the vortex river and forming a dam with a height of160m. Forty-five days later, the congested river burst and was seriously damaged hundreds of kilometers along the river. In Yanchihe Phosphate Mine in Yuan 'an County, Hubei Province, due to underground excavation, the mountain cracked and the displacement suddenly increased after the rain. 1in the early morning of June 3, 980,1100,000 square meters of mountain suddenly collapsed and landslide, and the buildings in the pit were destroyed. Office buildings, dormitories, a large number of mining machinery and more than 280 employees were instantly buried under the ruins of more than 20 meters.