What is the concept and content of sponge city?

1. Concept: Sponge city is a new generation of urban storm water management concept, which means that the city can adapt to environmental changes and cope with natural disasters caused by rain like a sponge, and it can also be called "water elastic city". The international term is "low-impact rainwater system construction", which absorbs water, stores water, seeps water and purifies water when it rains, and releases and uses the stored water when necessary to realize the free migration of rainwater in the city.

2. content: to build a sponge city, we must first change our ideas. The traditional urban construction mode is full of hardened roads. When it rains heavily, it mainly relies on "gray" facilities such as pipes, canals and pumping stations to drain water. Taking "quick drainage" and "terminal concentration" control as the main planning and design concepts, it often leads to waterlogging when it rains.

According to the Technical Guide for Sponge City Construction, urban construction will give priority to the use of "green" measures such as grass ditches, permeable bricks, rain gardens and sunken green spaces to organize drainage, with "slow drainage and slow release" and "source dispersion" as the main planning and design concepts, which not only avoids floods, but also effectively collects rainwater.

The demand for funds is large

Chen Zhenggao, Minister of Housing and Urban-Rural Development, has publicly disclosed that the investment in sponge city construction is expected to reach 1 million yuan to 15 million yuan per square kilometer. Lu Kehua, deputy director of the Ministry of Housing and Urban-Rural Development, also said that the first batch of 16 pilot cities plan to invest 86.5 billion yuan in three years with a construction area of more than 45 square kilometers.

according to the current national sponge city construction plan, it is estimated that by 22, more than 2% of the built-up areas of 658 cities in China need to meet the design standards, and the total annual investment in the country is expected to exceed 4 billion yuan. By 23, more than 8% of the urban built-up area will meet the target requirements, requiring about 1.6 trillion yuan of funds.