Analysis Of Water Quality Influencing Factors And Water Quality Prediction In The Three Gorges Reservoir Area

With the rapid development of China’s economy,the sustainable development of water environment has become a very important issue.As one of the most important parts of the Yangtze River,the water quality of the Three Gorges Reservoir area will directly or indirectly affect the water environment of the Yangtze River Basin,thus affecting the economic development of our country.The water quality of the Three Gorges Reservoir area is affected by many factors.It is necessary to find out what factors affect the water quality of the reservoir area and the relationship between the water quality and its influencing factors.It can not only control the water quality influencing factors,but also pave the way for the water quality prediction research,so as to predict the water quality change trend in advance and do a good job of water pollution prevention and control in advance.Based on the data of four water quality indexes(p H,DO,COD_MN,NH3-N)and a number of potential water quality influencing factors（rainfall,sediment inflow,sediment outflow,deposition,industrial wastewater discharge,urban domestic sewage,goods passing through the Three Gorges,ship oil sewage,oil in ship oil polluted water,ship domestic sewage,etc.）,this paper studies the water quality of the Three Gorges Reservoir area The relationship between water quality and its influencing factors,and use the selected water quality influencing factors to predict the water quality in the reservoir area.First of all,based on the monitoring data of p H,do,COD_MN and NH3-N in the Three Gorges Reservoir area from 2008 to 2017 and the multi statistical data of potential multiple water quality influencing factors,this paper analyzes the single indicators of the two by correlation analysis,and selects the six factors that have the most significant impact on the four water quality,including industrial wastewater discharge,urban domestic sewage,goods passing through the gate Domestic sewage from ships,sediment discharge from storage,sedimentation,etc.Secondly,we use the canonical correlation analysis method to study the correlation between the selected six water quality factors and the four water quality indicators.According to the typical correlation coefficient,the typical correlation model,the typical structure analysis and the redundancy analysis results,we prove that the two systems have significant correlation.Finally,through the establishment of regression model and neural network model,four water quality index data and six water quality influencing factors data are taken as sample basis to predict the water quality of the reservoir area;the results show that the regression model is only suitable for the short-term water quality prediction,and the long-term water quality prediction will produce obvious errors,while the neural network has a high accuracy for the short-term and long-term water quality prediction For the regression model,the neural network model is more suitable for the water quality prediction of the Three Gorges Reservoir area.