1998 After the flood, why didn't there be a big flood?

The flood in 1998 can be said to be a flood in the whole basin? Natural disasters? 、? Man-made disasters and geographical defects. Deforestation has led to serious soil erosion in the Yangtze River basin, and the forest coverage rate in some places is even less than 3%. Therefore, when the continuous rainstorm in the main flood season is out of control, the storage capacity and peak clipping function of rivers and lakes are fully reflected. 1998 catastrophic flood caused 223 million people to be affected, 4 150 people died, and 6.85 million houses collapsed, among which Jiangxi, Hunan, Hubei and Heilongjiang provinces suffered the most. The reason why we didn't encounter such a devastating flood after that is that extreme weather didn't happen again. On the other hand, the flood in 1998 woke us up. Many water conservancy projects have been built in the Yangtze River basin, and the control station of the main stream is to defend the flood level of the 1998 flood. ? Any flood is a disaster for those who have witnessed it, and I believe no one will want to witness its destructive power. However, we can't ignore the rain warning on weekdays. Although there may not be such a big flood, it is not uncommon for cities to be flooded. Knowing in advance can also effectively reduce some major economic losses. In recent days, there has been a lot of rainfall in China, mainly in the south. Among them, Hunan, Guangxi, Guangdong and other places all experienced heavy rain or heavy rain during the day on the 25th, covering six provinces in total, with the strongest rainfall reaching 95 mm, and some heavy rains (102 ~ 223 mm) occurred in Hechi, Guilin and other places in Guangxi. With the continuous development of rainfall, a new round of heavy rainfall will continue.

According to the rainstorm warning issued by the Central Meteorological Observatory on May 25th 18, there will be heavy rainstorms in the main areas along the southeast coast of China from 20: 00 on May 25th to 20: 00 on May 26th, with heavy rainstorms in southern Jiangxi and northeastern Guangdong, with the maximum rainfall reaching 150mm, which is really strong. Of course, geographically, it is mainly concentrated in the early stage.

Let's take a closer look at the situation. Data show that in the next 24 hours, there will be heavy rain or rainstorm in parts of five provinces, including central and northeastern Guangdong, southwestern Jiangxi, western Fujian, northwestern Yunnan and southeastern Tibet. Guangdong, which needs special attention, experienced a once-in-a-century rainfall only a few days ago. Now heavy rains can be seen in the Pearl River Delta region, and we need to pay attention to the impact of rainfall, the strongest of which. After that, there were 70 mm rainstorm spots and 80 mm rainstorm spots in Fujian and Jiangxi. This is the basic situation.

After this period of time, the basic rainfall has entered the southeast waters of China, and there is only moderate to heavy rain in the coastal areas. According to the data of the Central Meteorological Observatory, from 20: 00 on May 26th to 20: 00 on May 27th, there was only heavy rain (50-80mm) in parts of northwest Yunnan, so a large range of sunny days will be on the line. Sunny day? Mainly in the south, the sunny days in the north lasted for a long time. Although there are many thunderstorms in Northeast China and North China, there is not much rainfall. Therefore, in the first half of May, the rainfall was in the south, especially in the south of the Yangtze River and South China, and in the second half of May, the rainfall in the southwest was gradually increasing.

Judging from the rainfall in the last 30 days, the cumulative rainfall in most parts of the south is between 100 mm and 250 mm, and slightly more than 25 mm to 50 mm in the southwest. At the same time, the most obvious rainfall is in the Pearl River Delta, also this year? Dragon boat water? The main development zones, and the outbreak of the South China Sea monsoon are also the main reasons for the increase in rainfall in South China, so we should pay attention to the fact that there is more rain in the south recently. After this wave, the rain in the south will appear again soon. In terms of time, the Central Meteorological Observatory believes that from 28th to 3rd1,the rain that lasts for four days is brewing again, and there will be moderate to heavy rain and local heavy rain in Jiangnan, South China and Guizhou.

On the whole, there will be three rainfall processes in the south of the Yangtze River in the next 10 day. From the perspective of rainfall weight, the cumulative rainfall in the central and northern parts of the Yangtze River will be 50-80% higher than that in the same period of normal years. What is the concept of 80% rainfall? Perhaps for many areas, the rainfall level is almost 1 month. This year's model in the south can't be a little similar to that at the beginning of last year. Of course, last year was mainly due to El Nino? Water delivery? Obviously, this year's changes are slightly the same, and the National Climate Center has also released it? Weak El Nino? The appearance of this phenomenon is expected to affect the rainfall this summer, but from the latest index, El Ni? o seems to be disappearing, which may not be the main factor affecting it. El Nino is unlikely to appear, and the specific situation will be analyzed later.

On the whole, there will be heavy rains in parts of central and southern Zhejiang, most of Fujian, eastern and southern Jiangxi, central and eastern Guangdong and northern Hainan Island. It should be noted that Guangdong and Jiangxi will be the key areas, with heavy rains, with rainfall ranging from100 mm to 250 mm, accompanied by short-term heavy rainfall, local thunderstorms and strong winds and other strong convective weather, with a maximum hourly rainfall of 30 ~. Therefore, extreme weather conditions are obvious, and everyone tries to stay at home when it rains.