River Network Hydraulic Calculation And Water Quality Simulation Of YangZhou West Downtown

The formation and development of the city is closely related with the rivers, but with the rapid social and economic development, population growth and accelerating urbanization process, it results in industrial wastewater and domestic sewage increased, and the amount of pollutants discharged into rivers is over the carrying capacity of water bodies, urban rivers are seriously polluted. This not only affects the urban environment, endanger human health, but also restricts social economy development, causing widespread concern.According to the water quality of river networks in Yangzhou west downtown, this article analyzes the necessity for water quality simulation. It plans to take measures to improve the water quality by citation clearance to divert water, and simulates the characteristics of the hydraulics and water quality in river networks under different conditions, analyzes the simulation results. The main contents are as follows:1. It analyzes the natural environment of study area, water quality and pollution status of profiles. According to the standards of surface water quality and the regional water function zoning,it assessed water quality to determine the main pollution load in the river.2. One-dimensional hydrodynamic model is built, in which Preissmann weighted implicit scheme is used to discrete Saint-Venant equations, and pursuit method is used to solve a single channel equations, and according to branch points of convergence conditions of Newton iterative method for solving the hydrodynamic one-dimensional river networks. It developed the simulation programs of the main city river network,generalized river network and estimated the parameters, simulated the river’s water hydraulic situation under different conditions.3. By establishing one-dimensional convection-diffusion water model, it used the chase-after method to solve discrete equations. Used one-dimensional hydrodynamic simulation results, it calculated the BOD, ammonia nitrogen simulation, contrasted and analyzed the trends of pollutants under different operating conditions,and it made effective improvement of urban water quality.