Study On Technical Manual Of Urban Rainwater Utilization In Tianjin

With the accelerating development of urbanization, the contradiction between thesupply and demand of water resources has become increasingly prominent. Theshortage of water resources has become an important factor restricting city sustainabledevelopment, especially in north China. Many large cities seriously short of waterresources. Tianjin is a water shortage city, the per capita possession of water resourcesis only1/15of the national per capita level and far below the international waterscarcity cordon of1000m3per capita.As an important part of the water circulation system in natural world, rainwaterplays a significant role in complementing regional water and regulating the ecologicalenvironment. Rainwater utilization is the most important way to achieve the target ofcity’s sustainable development and promote the construction of a resource-saving,ecolofical livable city at the same time.This dissertation focuses on the technology of rainwater utilization in city andsearch for sustainable stormwater management model suitable for our country thencompose the manual of rainwater utilization. The main research contents include:(1) Rainwater management planning should be integrated into the existingresources, such as environment, society, development, livable and other factors.According to the size of the region, control management level should be divided intowatershed planning, subwatershed planning, environment management planning andstormwater management planning. Graduated stormwater management system shouldbe established to retent surface runoff which has been increased by urbanization stepby step.(2) Summary both domestic and abroad rainwater utilization practice, thecommon measures including: Roof rainwater utilization, Concave down greenbelt,Natural purification technology, Permeable pavement, Rainwater storge and Waterrecharge. The utilization of these measures can aviod the city waterlogging and at thesame time obtain considerable economic benefit, environmental benefit and socialbenefit.(3) According to the reaserch and engineering practice, the rainwater utilizationpractical method and design parameters which provide planning basis and technicalsupport for future rainwater project were summaized.Through the reaserch, we establish a multi-level management system. The control level should be divided into watershed planning, subwatershed planning,environment management planning and stormwater management planning. What’smore, a sustainable rainwater utilization model suitable for our national conditionsshould be formed, which based on infiltration, storage as a supplement, attention tonatural purification, prudent treat stormwater recharge and promote comprehensiveutilization.