The State Council issued a document saying that by 2025, the new urban area will not reproduce the city looking at the sea. What is a city looking at the sea?

Looking at the sea in the city is the phenomenon of urban waterlogging. Urban waterlogging has brought serious inconvenience to China's production and life, and also posed a great threat to people's lives and property.

Urban waterlogging refers to excessive precipitation. So that it exceeds the extreme value of urban displacement, causing a large amount of water in the city. It's like a sea suddenly popping up in the city. So it's also called seeing Haicheng.

Urban waterlogging is a common phenomenon in China, especially in summer, when it often rains heavily. The interval before and after is very short and dense, and a lot of rain has accumulated in a short time, and the city is soaked in soup.

Urban waterlogging is also related to topography. Because there were few cities in the past, the choice of areas was more convenient, but now there is less and less land available for building cities, and most areas will be flooded. Because the drainage system of modern cities is not perfect, there are some relatively low-lying places, such as under overpasses, bridges and underpasses, where serious waterlogging will occur after rainfall.

The occurrence of urban waterlogging is also closely related to the drainage system in China. Urban underground waterways are not very dense, drainage pipes are not changed all the year round, and the displacement is low and not updated in time, resulting in waterlogging. Another example is asphalt roads and cement roads, because of poor water permeability. It is easy to accumulate a lot of rain in a short time.

In addition, because the urban internal environment is a large area of reinforced concrete and lacks vegetation, vegetation is an important backbone for storing rainwater. Secondly, because the temperature in cities is generally higher than that in surrounding areas. The heat island effect will lead to urban rainfall concentration. Finally, due to the large amount of automobile exhaust emissions in cities, condensation nuclei are easy to appear in clouds, which increases the probability of rainfall.

Urban waterlogging will lead to a lot of water on roads, making it impossible to travel, leading to local water and electricity cuts and interruption of normal work and life. However, due to various problems existing in urban construction itself, urban waterlogging is only the cumulative result of these problems.

So this time, the State Council put forward some opinions about urban waterlogging. Next, we will focus on building a sponge city, a resilient city. It is required that by 2025, all parts of the country should lay a solid foundation for reducing precipitation emissions from the source, comprehensively lay urban groundwater pipelines, and synchronize with the discharge of accumulated water to deal with the emergency treatment of waterlogging. For some low-lying areas, when there is waterlogging in the old city, it will be drained in a short time. Areas where serious waterlogging incidents have occurred many times should be thoroughly cleared. Important municipal projects should play an emergency substitution role when the rainfall really exceeds the load.

During the tenth five-year plan period, the prevention and control of urban waterlogging has become one of the key tasks, and it is expected that certain results will be achieved within five years.