Water Quality Assessment And 1-D Water Quality Model Of Tuoketuo Section Of The Yellow River

Water is is one of the most important material resources for human beings.Nowadays,with the rapid development of the society and the economy,the pollution of the water environment is becoming increasingly serious.The river water quality in China restricted the survival and development of human beings.The evaluation and prediction of water quality of river environment has become the core issue of current river water environment management.Therefore,the study of the river water quality and the transport patterns of pollutants in the water can not only know the current status of river water environment,but also ensure the water security along the river.In this paper,mathematical statistical methods,comprehensive water quality index method and matter element analysis method were used to analysis and evaluate the water quality of the Yellow River Tuoketou section from Toudaoguai Section to Putanguai Section,on the topography and hydrological data of the river course,the HEC-RAS software was used to conduct the one-dimensional water quality of the pollutants in the river section.The first component was the indicator of nitrogen,phosphorus nutrients and organic pollution indicators.It was the most important water quality evaluation factor,which contained the most information and can directly affect the quality of the water.Therefore,the four indexes with the maximum load value of the rotation factor load matrix of the first principal component were selected as the water quality evaluation indexes of this study,which are chemical oxygen demand?COD?,total phosphorus?TP?,total nitrogen?TN?and ammonia nitrogen?NH₃-N?,respectively.The water quality evaluation of these four water quality indexes can basically reflect the water quality.At the same time,spatio-temporal changes of water quality monitoring data and water pollution characteristics from April to August 2017 were analyzed.The changes of TN and COD over time along the sections were basically the same,showing a overall"W"trend,and the concentration values in April,June and August were higher than those in May and July.The variation trend of TP fluctuated with time but is not obvious while the change of NH3-N was more stable.The maximum concentration of the four kinds of pollutants all appeared in big Heihe section,August.Except NH₃-N,the other three kinds of water quality indexes did not meet the target water quality III requirement.The water quality assessment of the Tuoketuo section of the Yellow River was evaluated using the comprehensive water quality index method.In the sampling period,the comprehensive water quality index I_wq of each section was the largest in the big Heihe section,which was in accordance with the observed water quality data.It was mainly polluted by TN and the single factor water quality index of TN reached 5.766,followed by TP and COD.At the same time,using matter element analysis method to evaluate the water quality is not only validated the correctness of the evaluation results of the water quality comprehensive identification index method,but also showed that the matter element analysis was also applicable to the evaluation of river water quality.The HEC-RAS software is used to simulate the longitudinal distribution of pollutant concentration in a river at a constant flow stage,namely one-dimensional water quality simulation,the simulated water level simulated by hydrodynamic simulation is basically consistent with the measured data of tou Dao cro hydrological station,and the simulation results are good;The total nitrogen?TN?and chemical oxygen demand?COD?in this river water body is simulated with one dimension water quality.The relative error of the simulated concentration value and the measured concentration of the water quality is less than 20%,and the simulation results are close to the reality,this software is used to predict the water quality of the river.