With rapid population growth and urbanization, the problems of air pollution, access to water and land, and scarcity of green spaces are becoming more serious. One innovative idea that has the potential to solve these difficulties is the concept of sponge cities. The action outline was proposed by Chinese researcher Professor Kongjian Yu in 2013. The idea quickly gained popularity around the world.
What are sponge cities?
Sponge cities are an innovative urban planning concept, which holds that cities should be designed to resemble natural ecosystems as much as possible – they should be able to absorb and retain water during rainy periods and then release it during dry periods. The sponge cities aim to create sustainable, environmentally friendly urban spaces.
How do sponge cities work?
The idea of a sponge city is based on the principle of a traditional sponge, which is to absorb water and other substances from the surface, store them, and then return them to the environment in the form of cleaner water and air.
The operation of the sponge cities is based on several main assumptions, which include:
- Increase green space: designers are trying to increase the amount of green space, such as parks, gardens, playgrounds and recreational areas, which act as natural stores. Plants help rainwater adaptation, which counteracts flooding and soil erosion. In addition, greenery absorbs pollutants and emits oxygen, which improves air quality in the city.
- Site permeability: instead of asphalt and concrete, permeable materials are used so that water can flow freely into the land. The use of such solutions reduces the risk of flooding and other natural disasters.
- Creating water retention systems: the concept is to build retention systems, which may include special rain gardens, retention basins or wells. This allows rainwater to be retained and gradually released back into the ground, avoiding soil erosion and keeping the soil moist.
Benefits of implementing urban retention solutions
Sponge cities have many advantages over traditional cities. First, they help solve water shortage problems, especially in regions where droughts are common. Second, they promote environmental protection by reducing water pollution, improving air quality and increasing green space. Third, they are more friendly to residents, as they provide more green space, which improves their health and well-being. In addition, such cities can also help reduce the risk of urban flooding by absorbing excess rainwater more quickly.
Sponge cities around the world
This concept is used in various parts of the world. In China, sponge cities are being built to improve water quality and protect against floods; in India, to improve air quality in crowded cities; in Europe, to improve the quality of life for residents and combat the negative effects of climate change.
Here are some examples of how cities around the world are applying the concept:
Shanghai
Shanghai is one of the largest cities in the world that has introduced the sponge city concept. A range of green infrastructure and permeable materials have been used to counter air pollution problems and flood risks. All 16 Shanghai districts have taken steps to renovate existing parks and green spaces or build new ones. Greenery has been incorporated into architecture, such as roofs and walls. In addition, building codes have been introduced to prevent flooding, requiring new buildings to be equipped with rainwater tanks.
Singapore
Singapore is a city that has managed to transform itself into a sustainable urban space, despite a shortage of space and high levels of air pollution. The city has achieved this by introducing a number of innovative solutions, such as:
- vertical greenery: Singapore has invested in green roofs, green walls and many other vertical gardens, so their surface area has increased, and this has helped improve air quality and reduce temperatures in the city;
- Waterproof infrastructures: flood control systems have been developed in Singapore that allow rainwater to be quickly removed, and stored and later used to irrigate plants in the city;
- Multi-level roads: the city has set its sights on expanding roads on several levels, allowing people and cars to move faster, reducing traffic congestion while increasing green space in the city;
- Increasing the number of green areas: Singapore is investing in the creation of new parks and gardens, helping to improve the quality of life for residents and the city’s appeal to tourists.
Rotterdam
Rotterdam has one of the largest marinas in Europe and is facing serious problems with rising water levels. In response to these challenges, the city decided to apply the sponge city concept. As part of the Rotterdam Water Square project, a huge public square was built that acts as a rainwater retention area. It was designed to be an urban green space during droughts and to accommodate huge amounts of water during rains.
Bydgoszcz
The sponge city concept has also found supporters in Poland. One of the cities that is successfully implementing this idea is Bydgoszcz. We are mainly talking about the largest-ever reconstruction of the city’s sewer system or the construction of new canals and reservoirs to manage rainwater. Bydgoszcz is betting on the creation of green-blue infrastructure – properly designed parks, planting buffer vegetation that increases the area of water absorption, using permeable paving on larger areas, creating rain gardens, etc.
Sponge cities are sustainable development
The sponge city concept is a response to the challenges posed by urbanization. Sponge cities allow for sustainable urbanization that takes into account environmental protection, improving the quality of life of residents and preventing violent natural phenomena. Implementing the concept requires investment and commitment from authorities and the public, but the results are more than noticeable and contribute to a huge improvement in the functioning of urban residents.