As China's most populous province of Henan Province, the capital of Zhengzhou, suffered a torrential rain once in a thousand years, my country's urban waterlogging and flood management have once again become a problem at hand. We must know that the rainfall in Zhengzhou reached 201.9 mm in one hour, and the rainfall in 3 days was as high as 617.1 mm. The hourly rainfall has exceeded the record in Zhengzhou in the past 60 years. According to understanding, the average annual rainfall in Zhengzhou is about 640 millimeters, which means that the super torrential rain in these three days has almost reached the annual rainfall in the area for one year. This heavy rain attack has a lot to do with the upcoming "fireworks" typhoon. It can also be understood that the typhoon attacked Zhengzhou through "remote control" means. It is worth noting that Zhengzhou suffered a super torrential rain once in a thousand years, but it is a microcosm of China's unique geographical factors, and even makes the city's waterlogging and flood control a problem again.
According to understanding, China, as a country with 9.6 million square kilometers of land, has a stair-like distribution of high west and low east in the overall terrain. In addition, with the advent of the rainy season, due to the influence of my country's topography and topography, the plain areas have become the main areas hit by rain. In addition, there is also a Yangtze River in China, which can be called the longest river in Asia. The river runs through China from west to east. It also presents a stepped distribution. Among them are the Qinghai-Tibet Plateau with an altitude of 3,000 to 5,000 meters, and the other The western plateau and the Hengduan Mountains in the Sichuan region. As a result, the elevation is below 500, the plains and hills in the middle and lower reaches of the Yangtze River are turbulent, and the area of the Yangtze River is wide.
Of course, the Yangtze River basin also includes lakes such as Dongting Lake and Poyang Lake. Eventually, these tributaries will converge with water sources and rainfall along the way and enter the Yangtze River, thus resulting in a huge amount of water energy in the Yangtze River. As a result, the Jingjiang area has become a high-prone area of floods. Due to the tortuous rivers in the area, coupled with the characteristics of high terrain and rapid water pressure, the main floods after the founding of the People's Republic of China occurred in this area. In addition, the Jiujiang City area in the Poyang Lake system is also another area with a high incidence of floods in the Yangtze River Basin. As for Zhengzhou, it is located in the lower reaches of the Yellow River. Since the river is also high in the west and low in the east, there will naturally be a stair-like distribution.
The most important thing is that the sedimentation in the Yellow River basin seems to be not turbulent, but the actual calm water surface is full of sediment. In addition, the precipitation of the Yellow River is basically concentrated in July to August, plus this The remote control of this typhoon will naturally put Zhengzhou in the "vortex center". Once the Yellow River area encounters heavy rains, it will produce strong soil erosion, so the nearby areas will be attacked by a large amount of muddy water. Therefore, even if Zhengzhou has a very powerful drainage system, it will still block the drainage outlets and cause urban waterlogging, and even the subway and railway station inversion that occurred this time.
As for flood control, as China's terrain is distributed in a stepped manner, the plain area where Henan Province is located can be regarded as the "best target" for flood attacks. Even if my country has built a large number of dams to control floods, it still cannot compete with the forces of nature. More importantly, as China continues to develop, each region has a number of powerful industries and enterprises, so economic losses are invisibly increased. It can be said that if we want to completely eradicate urban waterlogging and flooding, it cannot be solved overnight. In addition to planting trees and afforestation to protect the environment, at the same time, every Chinese should also stop cutting trees and destroying the soil. Only by paying attention to the protection of the environment by the whole people can our country find a more reasonable solution.
（writing/alittletyrant）