RESEARCH AND PRACTICE ON WATER SYSTEM AND SPONGE CITY CONSTRUCTION TECHNOLOGY OF TIANJIN ECO-CITY

Focusing on the goal of building a high-standard water system of Tianjin Eco-city, this paper analyzed the water environment problems and technical need at different stages of development, comprehensively carried out research on the planning, construction and management technology of water system and sponge city, and innovatively formed a new water system planning mode of Eco-city that coordinated all water related facilities, and a sponge city planning strategy that combined the construction of large water systems with the whole process of gray, green and blue. It developed the technology of multi-source and multi-functional purification and treatment of unconventional water, the technology of water quality maintenance and ecological restoration of landscape water, the rainwater runoff pollution control technology of biological detention facilities in saline alkali areas, the rainwater regulation and utilization technology under the influence of saline alkali, the landscape ecological improvement technology based on the improvement of saline soil and the construction of salt tolerant plant communities. And it constructed Tianjin Eco-city water system intelligent management platform, based on the water hydrodynamic-quality coupling model, multi-source water replenishment optimization scheduling model and waterlogging model. The research results had been applied to the planning, construction and management of the water system of Tianjin Eco-city and sponge city, achieving an unconventional water utilization rate of 50% above, water quality class Ⅳ of Environmental Quality Standards for Suface Water(GB 3838—2002), an annual total runoff control rate of 80% above, a runoff pollution reduction rate of 65% above(based on SS), and an annual total rainwater resource utilization of more than 300000 m³. It also optimized the structure of water resources, improved the efficiency of water resource utilization, and comprehensively improved the water environment quality of Tianjin Eco-city. The collaborative management level of dynamic linkage and joint control of water related facilities had been improved. The former saline alkali wasteland has become a prosperous and livable new city, which provided reference for the high standard construction of water systems and sponge cities in similar regions.