Cities can be more resilient to climate change if they are able to generate more green areas and trap maximum rainwater. There are many strategies such as draining asphalts, wells, vertical gardens or green roofs. A few years ago, the concept of “sponge city” was born in China, created by landscape architect Kongjian Yu. This is a model that consists of converting large areas of cities into porous river parks that drain water.
And according to a report from the Intergovernmental Panel on Climate Change (IPCC), 700 million people in the world already reside in areas where rain events have intensified, a figure that is expected to increase with the increase in global temperatures. .
China is a pioneer in this type of projects that has already exported to various countries such as Thailand, the United States and France. They are enormous esplanades that can retain and filter rain or river beds into the ground. In addition to avoiding large floods of water when there are floods, these areas allow rainwater to be stored, lower environmental temperatures, minimizing heat islands, and promote biodiversity.
“Sponge cities” are an example of nature-based solutions (NBS). Proposals inspired and supported by nature that use or imitate natural processes to contribute to improving water management. When a solution of this type is implemented it may involve the conservation or rehabilitation of ecosystems, or the improvement or creation of natural processes in artificial ecosystems.
Not all cities can become “sponges”, but they can implement nature-based solutions, such as green roofs, permeable pavements and bioremediation that, together with the restoration of wetlands and urban rivers, help mitigate the impact of pollution. urbanization on natural ecosystems.
One of the strategies that many cities, such as Barcelona, have implemented is the sustainable urban drainage system or SUDS, with pavements or green areas that store and purify rainwater. Until a few years ago, hard squares were built that did not filter water or waterproof pavements were used, so that rainwater was lost through the sewer and ended up contaminated in rivers and seas.
