Sponge city

　　Sponge city is to realize the virtuous hydrological cycle of the city, improve the infiltration, storage, purification, utilization and discharge capacity of runoff and rainwater, and maintain or restore the "sponge" function of the city through a variety of technical ways such as "seepage, stagnation, purification, use and discharge". We follow the low-impact development model to quantitatively analyze problems, from the perspective of completing the overall goal, coordinate the source-process-end engineering system, coordinate the relationship between gray and green facilities, clarify the goals to be achieved by each watershed engineering measure, select technical means and measures with strong operability, and provide solutions to ensure the overall project implementation effect.