The international name is "low-impact rainwater system construction", which absorbs water, stores water, seeps water and purifies water when it rains, and releases the stored water when necessary to realize the free migration of urban rainwater. ?
Starting from ecosystem services, it is the core of sponge city to build water ecological infrastructure through cross-scale construction and combining with various specific technologies.
design concept
To build a sponge city, we must first change our concepts. 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 often leads to waterlogging when it rains, and drought and waterlogging turn sharply.
According to the Technical Guide of Sponge City Construction, green measures such as grass ditch, permeable brick, rain garden and sunken green space will be given priority in urban construction, and the main planning and design concepts of "slow drainage and slow release" and "scattered source" will not only avoid floods, but also effectively collect rainwater.
Building a sponge city, that is, building a low-impact rainwater development system, mainly refers to achieving a benign hydrological cycle of the city through various technical channels such as "infiltration, stagnation, storage, purification, utilization and drainage", improving the ability of infiltration, storage, purification, utilization and discharge of runoff rainwater, and maintaining or restoring the sponge function of the city. ?
supporting facilities
To build a sponge city, there must be a "sponge body". Urban "sponge" not only includes rivers, lakes, ponds and other water systems, but also includes urban supporting facilities such as green spaces, gardens and permeable pavements. Rainwater permeates, stagnates, purifies and recovers through these sponges, and finally the remaining runoff is discharged through pipe networks and pumping stations, which effectively improves the standard of urban drainage system and relieves the pressure of urban waterlogging.
Extended data:
Six major measures
1. Infiltration-Reduce surface runoff from the source by increasing green space rate and using permeable pavement.
2. Stagnant flow-detention of rainwater to delay the peak time of runoff.
3. Regulation and storage-Regulation and storage of rainwater through engineering measures such as rainwater collection can reduce the peak flow, create conditions for rainwater utilization (see below) and save water.
4. Cleanliness-Purify rainwater, reduce pollution and improve urban water environment. The representative practice is ecological wetland.
5. Use-The stored rainwater is finally used as a resource.
6. Drainage-residual rainwater is discharged into the drainage pipe or natural water body. ?
trait
Sponge city has several characteristics:
1, try to digest the rain in the sky. This is commonly called water storage. There are surface water storage, such as reservoirs and lakes. There are permeable pavement, underground water cellar and other underground water storage.
2. The local water must be as clear as a spring. This is commonly known as sewage treatment. Sewage produced locally must be treated on the spot. The burden of sewage treatment cannot be left downstream.
3. The surface water and underground water left in the local area must be used repeatedly and effectively.
4. The block of each sponge city should try to meet all the local water demand.
5. Gradually improve the ecological and environmental functions of the sponge city.
6. The ideal goal of the sponge city is to build the sponge city into a new green mountain and green water, and make the sponge city return to an integral part of the natural ecology.
References:
Baidu encyclopedia-sponge city