Numerical Simulation And Risk Control Of Sudden Water Pollution In Water Transfer Project

In order to solve the problem of extremely uneven temporal and spatial distribution of water resources in China,inter basin water transfer projects have sprung up.In recent years,sudden water pollution accidents occur frequently,which not only destroys the safety of water supply quality,but poses a certain threat to the life and health safety of the people along the line and in the water supply area.At present,the research on simulation prediction and risk control of sudden water pollution accidents in water transfer projects is not perfect.Therefore,this study takes "risk source level evaluation-simulation prediction-Emergency Regulation" as the main line to study the numerical simulation and risk control of sudden water pollution in water transfer project.The main contents and results are as follows:(1)Assessment of risk sources of sudden water pollution.Based on the PSR model,the risk grade comprehensive evaluation system of risk sources of sudden water pollution accidents is constructed,and the index assignment basis is determined in combination with the existing research and standards;Build a combined weighting optimization model integrating the advantages of analytic hierarchy process and entropy weight method to calculate the index weight;Take the specific risk enterprise as an example to evaluate the risk level.(2)Simulation and prediction of the impact range of sudden water pollution accidents.Based on the MIKE11 model and combined with the engineering design data,the hydrodynamic water quality model of the engineering water conveyance channel is established,and the simulation of various sudden water pollution accident scenarios is carried out;Set up comparative working conditions to analyze the impact of accident discharge flow,discharge concentration,discharge duration and total discharge on section concentration results,and explain the feasibility of treating sudden water pollution accidents as instantaneous point source pollution;The prediction formulas of pollution threshold and pollutant impact range at each accident point are studied from the perspectives of whether it will cause the pollution of downstream key protection targets and the diffusion law of pollutants.(3)Emergency control of sudden water pollution accidents.Determine the flow regulation,gate closing regulation and discharge regulation methods,and study whether reducing the flow in the flow regulation method can reduce the concentration of pollutants when they reach the concerned section through numerical simulation;Based on the pollution threshold and numerical simulation,the hydraulic regulation system of sudden water pollution accident is proposed.Through the pollution threshold,the need for hydraulic regulation is quickly judged,and the emergency regulation scheme and regulation process are determined in combination with numerical simulation;Taking the specific accident scenario as an example,it provides a reference for the regulation of sudden water pollution in the project,and has engineering practical value.