What are the major grievances in history?

When it comes to the great floods in history, the first thing that comes to my mind is Dayu's flood control. At that time, floods often occurred in the Yellow River basin. In order to prevent floods and protect local agricultural production, Emperor Yao was in a hurry and invited experts from all sides to control water. Dayu changed the blockage to diversion according to his father's experience in water control. Using the natural trend of water, water is introduced into dredged rivers, lakes and depressions from top to bottom. So as to absorb the flood. It has been recognized by the people.

Then I want to talk about the flood in Hunan on 20 17 last year. The truck flood was actually a flood beyond history. June 22nd to July 2nd, 20 17. It rained heavily 1 1 day. The accumulated precipitation is 452 mm, of which the highest water level at Changsha Station can reach 39.5 1 m.. It is 40 cm higher than the historical highest water level of 39.18m. This precipitation is equivalent to the water volume of five Dongting lakes.

Among them, Changsha is the most serious place hit by this rainstorm. When we look at the figures, the precipitation of 452mm doesn't feel very powerful. But think about it, Changsha is only 12000 square kilometers. The total amount of precipitation converted from 452mm water is 5.3 billion cubic meters, which is equivalent to these meters of water falling into Changsha. Just like people are particularly thirsty, it is easy to choke when they are in a hurry to drink water.

March 7 this year. Heavy rain in Hangzhou. Not only accompanied by heavy rain, but also hail disaster. It's still snowing in Hangzhou in March, and it's actually very rare to thunder in the snow. The flood in Hangzhou in early March was also very serious.

Floods always have the following characteristics. First, the rainfall intensity is relatively large and the coverage is relatively wide. Secondly, Hongfeng is tall and big. In the end, all the main and tributary floods are fierce and will form a very bad situation together.

The weather has changed abnormally this year. Please pay attention to the weather and do a good job in flood control and disaster relief.