What does the once-in-a-century flood in Ya 'an section of Qingyi River mean?

Sichuan province sounded the first-class flood warning, or? Once in a hundred years? Since the flood in August, the flood control work in Sichuan has been extremely severe, and it is always in an emergency standby state. Especially on August 18, the once-in-a-century flood disaster occurred in Ya 'an section of Qingyi River, which caused the water level in the connected waters (Dadu River and the lower reaches of Minjiang River) to skyrocket, and it was about to exceed the warning line and the guaranteed water level. According to preliminary statistics, there are nearly 250,000 people affected by disasters in this city, and they are in urgent need of resettlement and assistance. In addition, many public facilities, dams and irrigation ditches were damaged by the flood, and people's property also suffered heavy losses.

In fact, the flood that caused Ya 'an to suffer this flood is not only rare in the literal sense of once in a hundred years. From the point of view of meteorological station, what is the technical term to describe it? An event with a probability of 1% in any year? . In various news reports? Once in a hundred years? The text adds a layer of mystery to the flood in Ya 'an District, but in fact, it is just a more menacing flood than before. People don't have to worry about whether it is really a once-in-a-century flood on time.

Besides,? Once in a hundred years? Flood disaster is not a fixed concept of time, but the probability of an event. Affected by natural conditions, temperature changes and other factors, once in a hundred years? Will the frequency of disasters fluctuate? Or higher than 1% or lower than 1%. For example, one of the chief culprits of heavy rainfall in China since August? The El Nino phenomenon, which used to form corresponding weather according to a fixed trajectory every year, happened last year, leading to the concentration of typhoons in the second half of this year, followed by heavy rainfall.

The disaster-ravaged Ya 'an area is really embarrassing. The suffering people are worthy of sympathy, but are there fire officers and soldiers and people heroes? Take the lead? I believe that the local people will be able to work together in Qi Xin to overcome this disaster and meet the beautiful tomorrow that will eventually come!