Study On One-dimensional Hydrodynamic And Water Quality Model Of Songhua River Basin

In recent years,sudden water pollution accidents caused by flooding and improper chemical production and transportation processes have occurred frequently,directly threatening human health besides affecting not only economic but also social development.In the past water pollution incidents emergencies,due to untimely emergency measures and inaccurate predictions,the scope of water pollution is difficult to control,with the pollution situation is deteriorating.Establishing a watershed model with emergency water pollution and flood simulation prediction functions is essential.Based on the hydrodynamic basin network module and convection diffusion module of HYDROINFO water resources information system,this paper establishes the one-dimensional hydrodynamic and water quality model of Songhua River Basin.Based on the Saint-Venant equation,the model uses the semi-implicit finite element method to construct the one-dimensional river network model.The finite volume method is used to establish the one-dimensional river network water quality model,which has the advantages of strong convergence and fast calculation speed.The focus of this paper is to solve the problem that the Songhua River basin has not only a large area but also a long river channel,besides there are many hydraulic structures and gates on the main stream,which have high requirements for the calculation accuracy of the model.The purpose of the model is to simulate and forecast flood and water pollution events by applying models,to understand the transport,diffusion and evolution of pollutants in water bodies and the changes in hydraulic characteristics of various sections.Provide the premise and scientific basis for supporting decision-making in response to flood events and emergency water pollution incidents.A large number of hydrological station measured data were collected in the model.The reliability of the model was verified by simulation analysis of typical flood conditions,flow from January to April 2006,and 2005 nitrobenzene leakage event in Songhua River.After calculation,the hydraulic characteristics of each section and the results of time and concentration values of pollutants reaching different sections in the pollution event were obtained,the calculated value is well fitted with the measured value.The results show that the model can accurately simulate and predict the hydraulic characteristics of various sections under the conditions of flood and sudden water pollution accidents,and the degree of impact and migration of pollutants.The one-dimensional hydrodynamic and water quality model of the Songhua River Basin is reliable enough to be applied to practical work.