The goal was to find better ways to plan and design green infrastructure to manage stormwater in cities. To do this, a method called the "sponge equivalent" was suggested. This method helps compare different types of green infrastructure to a standard one called a bioretention pool, making it easier to understand and use. By studying an area in Beijing, it was found that different combinations of green features like green roofs and water storage tanks could help control runoff effectively. This method can help cities plan for better stormwater management and promote eco-friendly development.