2. In Wuhan and other big cities in China, the main cause of flooding is that the diameter of drainage system is too small and the displacement is too small. There should be a scene in an American blockbuster, that is, a gun battle in an underground drainage channel. The diameter of underground drainage pipeline is 10 meter, but the diameter of drainage pipeline in China is 1- 1.5 meter. Drain ghosts. Almost urinating!
3. I remember that before 1980s, most places where Wu Da went to the street crossing and Chagang were ponds and paddy fields, and most places along the East Lake in Shui Yuan were Metasequoia wetlands. Now, all the buildings have been built, and there is no place to store water, which will inevitably flood the roads. In this regard, the planning department of Wuhan has the responsibility, and so does Wuhan University.
No matter how heavy it rains in America, you will find that there is almost no water on the ground after going out for a few hours. We should not only build tall buildings, but also pay attention to the construction of sewers. Our city looks much better than America's, but there is still a gap in essence. 5. I have been in contact with municipal work for a short time and know a little. In my third-tier medium-sized city, the drainage facilities are basically negligible. The reason is that there is no systematic drainage facilities planning, and there is no drainage network extending in all directions. If there is heavy rainfall, two-thirds of the streets in the whole city will be flooded. The main and secondary roads are still like this, not to mention the small streets and alleys. Relevant departments will apply for funds for dredging every year, and all they can do is to remove the grate of the drainage well and dig it down. Water accumulation is mainly solved by leakage, not to mention the diversion of rain and sewage. By 20 10, our newly-built roads almost doubled, but ironically, the problem of road water accumulation has not been solved, but has become more and more serious.