Create a sponge urban construction make the city back to nature

`Sponge City is a new concept of urban development, referring to the city like a sponge, when rain is encountered on the spot or nearby can absorb, save storage, infiltration, purify rainwater, groundwater recharge, regulation of the water cycle; when the drought Conditional release the reservoir of water, and make use of, so that water transport activities in the city of more "natural." "Sponge cities" broke the traditional "row-based" urban stormwater management concept to construction and residential, green space and plaza, urban roads, urban water systems and other urban infrastructure as a carrier, give full consideration to the safe operation of urban infrastructure and urban water security issues, hydrological conditions differences, planning targets and operational feasibility of the project, and the comprehensive utilization of infiltration, stagnation, storage, net, use, discharge and other ecological technologies to build new urban low impact development stormwater systems. Sponge traditional concept of urban development pattern of urban construction, hardening of the road everywhere. Every heavy rain, mainly rely conduit, pumping stations and other "gray" facilities to drain the water in order to "quickly ruled out" and "end-centralized" control as the main planning and design, often resulting in heavy rains, floods, droughts and Sharp. Heavy rains, floods and gradually evolved into a chronic disease of large and medium cities. However, no longer "the city to see the sea" is not just pipeline expansion that simple. Currently (2014) 99% of China's cities are fast discharge mode, the rain fell on the hardened ground can only concentrate discharge from the pipe fast. Strong rains come to feel a little of the pipe repair is not enough, and many serious water shortage city just let 70 percent of rainwater lost in vain. Shenzhen Guangming New District, for example, the average annual rainfall of 1935 mm, the Flood Season in concentrated urban areas, on the one hand there are 26 waterlogged points, waterlogging serious; the other hand, severe water shortages, more than 70% of the water from the area by redeployment water. This shows that the idea of ??urban drainage and drought must be adjusted to the burden of rainwater into the city to quench their thirst of wealth. According to "sponge City Construction Technology Guide," will emphasize the priority to the use of urban construction ditch grass, rain gardens, sunken green spaces and other "green" measures to organize the drain, "the slow-release row" and "source decentralized" control as the main planning design. Cities should build sponges are "cavernous." City "cavernous" includes both rivers, lakes, ponds and other water systems, including green spaces, gardens, permeable pavement such urban facilities. Rain through these "cavernous" infiltration, detention storage, purification, reuse, the last remaining part of the run-off through the pipe network, pumping stations efflux, which can effectively improve the standard of urban drainage systems, mitigation of urban waterlogging stress.