The weather in Hengnan is one month.

Rainstorm: generally refers to rain with heavy precipitation intensity, which is stipulated by China's meteorological department:

1 and 1 hour rainfall 16 mm above rain;

Rain with a rainfall of 50 mm or more within 24 hours.

Heavy rain has the characteristics of "concentration" and "high intensity". It pours down as soon as it appears, causing water accumulation in depressions, sudden increase of runoff and sudden rise of rivers in a short time, which is a serious disastrous weather. Because of the obvious monsoon in China, the annual rainfall is mostly concentrated in May-September, so this period is designated as the "flood season". The "flood season" is the most tense and critical period for the meteorological department's forecasting service.

There are also many disasters caused by heavy rains in China. For example:

1, July 2004 10, Beijing was hit by a torrential rain, and most of the roads in the urban area were flooded, and the traffic was almost completely paralyzed.

2. In the Yinhu Cave Scenic Area in Fangshan District, the highway rushed into a rocky ditch. The rainstorm that lasted for nearly 6 hours completely destroyed a 2-kilometer-long road surface in Yinhu Cave Scenic Area in Fangshan District. The roadbed was also washed into a rocky ditch by the rain. The water is more than half a meter deep and the current is fast. The transportation of five coal mines in three villages on the mountain was completely interrupted.

3. In July, 2004, the continuous rainstorm caused by typhoon led to mudslides and flash floods in central and southern Taiwan Province Province, which aggravated the local disaster. 2 1 person died, 9 people were missing, and the total loss of agricultural disasters exceeded NT$ 2.3 billion. The loss of fishery facilities exceeded NT$ 70 million. Floods caused 265,438+00,000 households in the central and southern regions to lose power. After emergency repair, there were still more than 654,380+03,000 households without power by the middle of the night on the 4th, among which more than 8,000 households could not carry out emergency repair due to road collapse, broken bridge and other reasons. In terms of water supply, there are still 200,000 households that have not resumed normal water supply. The flood caused 94 roads to collapse in the central and southern regions, and 50 roads have not been repaired and opened. Due to the damage of subgrade, some sections of the railway stopped.

4. The rain disaster caused serious losses to Yili Prefecture. From July 18 to July 20, 2004, a sudden rainstorm (rainfall 103mm) occurred in Yili Prefecture, causing 220,000 people to be affected. The affected area of crops is 32,449 hectares, and the crop failure area is 154 14 hectares. There were 268 dead animals and 30 collapsed houses. 13,508 households with 25,423 dangerous houses and 67,246 houses leaked rain, resulting in economic losses of 63.85 million yuan (including agricultural losses of 9.42 million yuan). 165438+1October 65438+The rain lasted for three days from 0: 00 to 3: 00, and residents' houses generally leaked rain, and quite a few houses have become dangerous buildings. According to statistics, the affected population was 4 10308 households with 4 1233 people and 3344 houses collapsed. There are 15430 houses that leak rain cracks and become 368 dangerous houses. Economic losses caused by the disaster 187 10000 yuan.

5. In September 2004, a rainstorm occurred in the east and north of Sichuan Province, resulting in 19 deaths, 2 1 missing and 40 serious injuries. The 24-hour rainfall reached 253.2 mm, and the water level of the river rose sharply, causing flash floods, mudslides and landslides. At present, there are 60 townships in the county, and 1, 0 1, 000 people are affected. Six people were killed, seven were missing and 37 were seriously injured. The direct economic loss was 654.38+56 million yuan.

6. In Guangdong Province, the high water level in Xijiang River, Beijiang River and Pearl River Delta will last for several days, and heavy rain will soak rivers and lakes for many days. After drainage, the flood caused 54 deaths and a loss of 2.4 billion yuan in Guangdong.

7. In April 2004, the urban area, Hengyang County and Hengnan County of Hengyang City, Hunan Province were suddenly hit by heavy rain, with the maximum wind force of 9 and the maximum wind speed of 23 meters per second. A century-old tree was uprooted, tiles were flying about, hail was half the size of a fist, and street billboards were rolled up by heavy rain and fell to the ground. The storm disaster has caused 7 deaths and 207 injuries. There were 2,430 houses collapsed, including 800 houses/KLOC-0, and 700 farmers were homeless. All 22 high-voltage electricity in the disaster area were paralyzed, and there was a power outage throughout Hengyang County. The affected area of crops reached 1 106 hectares, including 366.9 hectares of crops and about 400,000 people.

8. Since mid-June 2005, the southern part of Taiwan Province Province has been hit by heavy rainfall, resulting in agricultural losses of more than 2 1.77 billion yuan, setting a record for agricultural rain losses in Taiwan Province Province. ...

More rain has also brought many landslides:

1.In August 2005, heavy rain continued in most parts of Hong Kong. It is reported that at least 24 floods, 20 landslides and 30 tree collapses occurred. Traffic on Lantau Island has been severely hampered by landslides. Landslides occurred in many places on Lantau Island due to the continuous rainstorm. Due to landslides in many places, two major roads on Lantau Island need to be closed. More than 200 tourists were trapped by heavy rain after visiting the Tiantan Buddha in Angping, Lantau Island. Some places are still flooded, and the water depth is more than one meter. There was also a car accident, 1 people were injured.

2. The Indian financial city Mumbai was hit by a tropical storm for two consecutive days, and more than 60 people died from landslides and floods caused by the storm. Most of the dead in Mumbai were residents of shanty towns on the hillside, and many of them were buried alive with their families. Heavy rain caused traffic jams in some places, and power supply and communication were interrupted. Of Mumbai12 million people, 60% live in slums. Schools in Mumbai have been closed and the campus has been used as a temporary shelter for homeless victims.

3.65438 In February 2003, the death toll caused by heavy rain and landslides in central and southern Philippines has increased to at least 15 1, and many people are still missing. Persistent bad weather, blocked roads, power supply and external communication, made the rescue work very difficult, and many victims dug with their bare hands to search for missing family members.

Less rain will also cause drought;

Drought: Drought is an agricultural meteorological disaster that there is no rain or little rain for a long time, which makes the soil moisture insufficient and the crop water balance destroyed, thus reducing production. It is also the most serious meteorological disaster in China. If drought is accompanied by destructive human activities, it will cause a series of more serious environmental deterioration problems, which are mainly manifested in three aspects in China: first, drought causes the continuous reduction of water resources and the increasingly prominent water crisis; Second, due to drought, the water level of the lake is reduced, and the water surface is reduced or even dried up; Third, drought has led to the obvious expansion of desertified land.

In 1 and 2003, most parts of Africa suffered from the once-in-a-century drought. About 654.38+500 million people in 36 countries face the threat of hunger. In 1983 alone,160,000 people died of hunger and malnutrition-related diseases. Answer adoption rate: 23.6% reported on September 7, 200813: 37. Do you think this answer is good? Good (1) and bad (1).

The rain in the poet's eyes is poetic, however, the rain in nature is endless. It can wash away bridges, flood and destroy crops, and bring disaster to mankind. Next, please talk about the different situations of rain from a scientific point of view.

1. Tell an example of rain flooding.

In ancient times, Dayu controlled water and Bangladesh was flooded.

2. List the strange phenomena related to rain: plum rain, Yu Qian, mud rain, acid rain and so on. Talk about the causes of their formation and the disasters they bring to mankind.

(1) Meiyu:

From the middle and late June to the early summer of the first half of July, the narrow area from the middle and lower reaches of the Yangtze River (or Jianghuai Basin) to southern Japan often has a continuous rainy period, with frequent precipitation processes and frequent heavy rains. At this time, it is the mature period of plums in Jiangnan, so it is called "Meiyu". The ancient poem "It rains at home in Huangmei season, and frogs are everywhere in the grass pond" vividly depicts the natural scene of the local rainy season. Because of the high humidity and temperature in the rainy season, clothes are easy to get moldy, so it is also called "mildew rain".

(2) Yu Qian:

(1) phenomenon:

Speaking of Yu Qian. According to the materials published in People's Daily, "One day in 1994, there was a sudden shower with a large number of ancient copper coins in Gorky State of the Soviet Union, which was called the copper coin rain". In China, there are many such examples. According to Ren Fang in the Southern and Northern Dynasties, in his book Strange Tales, "During the week, it rained all day in Xianyang." "When Wang Mang was young, it rained five baht in Weiyang Palace."

"In the Han Dynasty, the family expenses of Yingchuan people were very high." According to the Records of the Song Dynasty and the Five Elements, "In July of the second year of Shaoxing, money rained or stones flowed out." There is also such a record in the Collection of Ming History: "Chenghua made friends on June 9, when it rained heavily in the capital, he often made money in the rain." Yu Qian is not a miracle.

Besides, we also know that there is golden rain. "Bamboo Chronology" contains: "Yu Xia eight years in summer and June, Xiayi rain gold." Later, Ren Fang wrote: "Confucianism said: It rained for three days in the era of Xiaxia. There is a saying in ancient poetry: "You can get peace and rain, and make it as low as earth. "... yes. "He wrote in Shuo Wen Jie Zi:" When Zhou Chengwang was in office, Xianyang paid gold. There is rain and gold in Xianyang today. " "In the second year of Emperor Hui of Han Dynasty, there was gold and black tin in the palace." "In the Han Dynasty, Weng Zhong's Confucianism was a masterpiece of poverty, and he lived in Weichuan. When it rains, his home is ten times. " I wonder if there is such a golden rain abroad?

And Grain Rain. Ren Fang said: "When King Huan of Wu was in power, Jinling gave food to the poor, and the rich did not rain." According to him, it seems that God can distinguish between the rich and the poor. Of course, this is an incidental meeting. Liu's Other Gardens in Song Dynasty

It also reads: "Zhang Jun, a native of Liangzhou, whose name is Gong Yan, spent nine years in Wuwei, stewed and planted." There is a drop of rice in the grain. For example, Cui Bao of Jin Dynasty wrote in "Notes on Ancient and Modern Times": "In the third year of Huidi, rice and rain fell in Guigong and Yangzhai." There are also rice reduction. Cui Bao also wrote: "In the four years of Yuankang in Xuan Di, Chang 'an was rainy and black millet. "History of Song Dynasty" and "Records of Five Elements" also said: "In June, it rained in Yuan You, Tujing Town, Linjiang County; It was rainy and dark in July. "Similarly," History of the Yuan Dynasty and Five Elements "contains:" In October of the eleventh year of the Yuan Dynasty, it rained like millet in the northeast of Quzhou; Shao Wuyu black millet, such as reed; Xinzhou is rainy and dark, and there are many counties and townships. People take it and eat it. "There is rain millet again. Cui Bao said: "In the fourth year of Jianyuan, it rained heavily." "Xuandi Festival for three years, Chang 'an rain black millet." Of course, there are also rain wheat. Zhang Hua's "Natural History" in the Jin Dynasty contains: "When Emperor Wu of the Han Dynasty, wheat fell in the county." There are many similar records in local county annals. I haven't checked them one by one, so I won't list them here.

If you only read the books mentioned above, you can't find all kinds of other interesting stories about rain. Actually, twenty.

There are countless materials in the five history notes novels. Then open the History of Han Dynasty and the Records of Five Elements, which wrote: "In August of the second year of Yong Guang, it rained grass in Yuan Di, but the leaves were cemented as big as a projectile." This can be called grass rain.

In addition, Cui Bao also said: "Han Emperor Yonghe Zhong, Chang 'an Yu Mian, are all white." He also said: "Xuan Di Yuankang was born in Nanyang for four years.

Rain bean. "History of Song Dynasty" and "Records of Five Elements" also contain: "In June of the second year of Yuanfeng, Zhongzhou was in the capital; In July, Wu Jia, Yudu, Nanbin County. " These examples of rain, bean rain and so on can show that when it rains, there are still many things that can fall with the rain, not just what we are talking about.

② reasons

So, how to explain this phenomenon? Are these supernatural phenomena? Obviously not. These phenomena are actually caused by cyclones. Cyclone, also known as return air, has long been known by the ancients.

Li, an astronomer in the Tang Dynasty, was quoted in the book "The Outline of Peeping" in the Ming Dynasty: "The return air suddenly rises, but turns like a horn, turns upward, and those who rise from top to bottom or grind the ground are collectively called return air." When the return air blows, sand and stones fly, rise from the ground and go straight to the sky. So things on the ground are often blown to the sky, far away, and then fall to the ground. In this way, the so-called strange phenomena such as Yu Qian and Jin Yu have been formed.

In fact, the reason for these phenomena is very simple.

When we go to the countryside, we often see a whirlwind rolling up sand and turning it into a yellow dragon. It is said that if people are in the center of this tornado, it is very dangerous. Even the birds in the sky can't escape when they meet this tornado. Therefore, "History of the Song Dynasty and Five Elements" said: "In December of the second year of Qingyuan, a million copper coins flew to Jin 'e Township, Wuxian County. "Of course it was blown away by the whirlwind." "Continued Literature General Examination" contains: Ming Dynasty, Hongwu eight years, Ku Qianfei. At that time, there was money on the houses of the people in Nantai, and every bamboo, or ten or twenty, was money. Jiang Yikui's Chang 'an Hakka Dialect in the Ming Dynasty also wrote: "The old tower in Zhuozhou is in Sanggan River, which is a famous town tower. In the first year of Jiajing, the tower collapsed and there were ancient coins in it, all of which flew empty. " When these records are connected with the examples mentioned above, the truth of the problem is very clear.