Prediction Of Water Quality In South Wuhan Based On Mann-Kendall Method And ARIMA Model

Water is the main source of regional economic development in Changzhou,and also a main channel to contain pollution.But in recent years,due to the rapid development of local economy,the excessive demand of natural resources and the massive release of various pollutants,the water bodies in The area have been seriously damaged.The permanganate index(COD_Mn)is one of the most important and readily available comprehensive indexes of organic pollutants in water environment monitoring in China.To assess the relative concentration of organic matter in Chinese waters.In this context,the content of COD_Mnin water bodies in Wunan area will be studied.Concentration COD_Mnin our country at present in the aquatic prediction work focuses on long-term forecast,its malpractice is because there is no management of government departments in the aquatic environment monitoring work force as effective factors,so the prediction results of the long-term monitoring data deviation is large,often and reality so as to lose the practical significance of the forecast.In addition,it is difficult for the government to make timely preparations in the face of water pollution due to the lack of short-term prediction data of COD_Mncontent.By modifying Nemero index method,Mann-Kendall trend test method and constructing ARIMA time series model,this paper discusses the water quality analysis results of ammonia nitrogen content,total phosphorus,total nitrogen and the change trend of COD_Mnlevel in the short term in Dawu South area,thus proving the relative error between the theoretical predicted value and the actual measured value.Thus,an environment numerical detection scheme with better detection accuracy is obtained.In order to study the environmental changes,driving factors and river regulation effects of the main river channels in south Wujin District,a comprehensive study is carried out for four main river channels（Wujin Port,Yong’an River,Wuyi Canal and Tai Gehe Canal）according to the long-term monitoring data of water body from 2016 to 2018,and the environmental development trend is studied and analyzed.The seasonal study and correlation data analysis of heavy pollutant discharge index in yongan river are also carried out.The results showed that from 2016 to2018,the water fluctuation of the four river channels was small and showed an improvement trend.Due to the influence of river dredging construction,the yongan river body has been declining since 2017.The concentration of ammonia nitrogen in wastewater,total nitrogen concentration and permanganate index decreased significantly（P<0.05）,and the total phosphorus content fluctuated.There was homology correlation between total nitrogen,ammonia nitrogen and permanganate index in Yong’an River.In addition,the seasonal variation of ammonia nitrogen content and total phosphorus was obvious,and the obvious rainy day was much less than the drought,so permanganate index did not change significantly,so did total phosphorus.The development level and economic structure of the city have experienced the transition from industry and agriculture to the tertiary industry city.