Construction And Application Of The Healthy Urban Water System Platform Based On Big Data And Decision Support

With the rapid urbanization process, the urban water system and original ecosystem were destroyed. Flash flood hit cities frequently, and urban water bodies were severely polluted. As disharmony of social water cycle and natural water cycle, contradiction between water supply and demand was prominent. Urban water system includes rivers, lakes, water treatment plants and wastewater treatment plants. Water intakes, sewage outfalls and estuaries staggered to each other. The urban water system present serious health problems. The land cover and water system change rapidly with fast urban sprawl. It is difficult to make systematic, comprehensive and fast decision for healthy urban water system using the traditional planning and construction methods. It is significant to provide strategies for the healthy urban water system by big data decision support platform.This study focus on the construction of spatial database and research of models library under big data support. The healthy urban water system decision support platform integrating hydrologic response model and water environment model based on network grid is developed. By providing decision support and technical solutions for building of healthy urban water system, the platform is applied in the planning, construction and management of urban water system in Liangjiang New Area. The main results of the study are as follows:(1)Against the needs of healthy water system construction in the Liangjiang New Area which is rapid urbanizing area in Chongqing, the spatial water system database supported by big data was established. The database contains digital elevation models, remote sensing, meteorology data, soil texture and watershed unit, rivers, lakes and reservoirs, water quality, social water facilities. The huge, diverse, complicated, integrated data spatial big data will promote the water system database.(2)Using flow direction basic algorithms and spatial topological relations based on digital elevation model, rainfall runoff paths are simulated with high-precision network grid. After unifying the land use classification system, mining water information in ultra-precision grid of land use and land cover. The parameters of hydrological response unit under the different slopes, different soil textures, different land-covers in Liangjiang New Area are summarized. Calculation of accumulated runoff's quantity and quality of parameters along the high-precision runoff network routine is achieved by the hydrologic response model.(3)Founded on hydrologic response model, water environment model is developed by big data processing and analytics. River network grid generalization and automatic numbering subsidizes the model preparation. Hydraulic quality control equation is separated by implicit finite difference. This model achieves the water quality simulation of 19 rivers in Liangjiang New Area. The parameter in water environment model is calibrated with land use, rainfall, hydrology and water quality monitored in flood and non- flood season of 2013 and 2014. And the model can be applied to urban water system water environment simulation and prediction.(4)The decision support platform of healthy urban water system is developed and applied in Liangjiang New Area. The platform simulates the status and developing trend of water system health in four scenarios(Current Mode, Planning Mode, HIGH Mode and BASE Mode). Combining the results and urban development process, technical solutions for building of healthy urban water system in Liangjiang New Area was yielded.Healthy water system construction mode is based on geographic information system, driven by hydrological response model and water environment model and organized with decision support platform. It takes into account the river and land use of the watershed. This mode would provide practical basis for sponge city construction. And the platform would technically support the construction, decision making and management of healthy urban water system. This study has reference significance and application value in urban water system construction.