Constructing "Sponge City" to Rehabilitate Urban Water Ecology

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New Earth Group


Constructing "Sponge City" to Rehabilitate Urban Water Ecology

In the past urban construction, the control of rainwater was based on the basic concept of "rapid exclusion" and "end concentration. And this is an important reason for the occurrence of urban waterlogging. Chen Jining, president of Tsinghua University, said that a large amount of rainwater is drained away, and rough pipe and canal systems are generally used to realize rainwater collection and centralized discharge nearby. In case of rainstorm, a large amount of rainwater runoff and its pollutants will be transported to the end of the pipeline in a short period of time, which will increase the risk of waterlogging in the downstream area. In fact, if most of the rainwater is left instead of drained away, the accumulation, infiltration and purification of rainwater in urban areas can be realized to the greatest extent, and the utilization of rainwater resources and ecological environment protection can be promoted. The basic idea of "sponge city" is to keep more rain and less drain.
Sponge city is a metaphor for cities like sponges. When there is rainfall, they can "absorb, store, infiltrate and purify" runoff rainwater locally or nearby, supplement groundwater and regulate water circulation. When there is drought and water shortage, they can "release" the stored water and make use of it, thus making the migration of water in the city more "natural". In other words, the "sponge city" is expected to digest a large amount of water originally discharged to the end of the pipe canal in advance through absorption, storage, infiltration and other links, and become an effective way to crack the "waterlogging every rain. After the completion of the sponge city, the rainwater drained away and the rainwater left behind will be 'upside down '. For example, in the past, 70% of the water in a city was drained into the pipeline, while 70% of the water in a sponge city was left behind.
How to stay rainwater? Sponge city construction emphasizes the priority of "source decentralized" control measures, in urban buildings and residential areas, roads, green space and other sites at the source, through the large-scale implementation of rain garden, sunken green space, grass ditch, permeable pavement and other ecological facilities first of rainwater infiltration, regulation and storage, effective control of rainwater runoff pollution load output, reduce the total amount of discharge runoff. It is necessary to transform the single, "fast discharge" model in traditional urban construction into a multi-objective and full-process comprehensive management model of "infiltration, stagnation, storage, purification, use, and discharge.
Relevant people pointed out that in the urban planning stage, clear control objectives and indicators should be put forward. For buildings and residential areas, urban roofs can be made green, and conditional residential green spaces should be fully "sunk", so that roof rainwater and road rainwater can first enter sunken green spaces for storage, infiltration and purification, etc. The construction of a "sponge city" to restore the urban water ecology is to create a better living environment and is also one of the important measures for sustainable development. Good ideas must have a solid backing. In recent years, the government has vigorously promoted the planting, which is a sponge city. A solid backing for development.

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