Study On Surface Water Quality Model Certification System And Eutrophication Model Evaluation

Surface water quality model is an important tool for environment management such as water environment assessment,water quality prediction and water pollution control.Model certification is the qualification assessment of the authority,such as the Ministry of Ecology and Environment,on the scientificity,applicability,advanced nature and stability of the model.The research of model certification system is the guidance of research activities of the whole model life cycle including model development,evaluation,application and promotion.The work of surface water quality model certification in China is still in the preliminary stage,and there is no standardized management method and corresponding model evaluation system.A set of standardized surface water quality model certification system and model evaluation system was proposed through literature collection,expert evaluation,analytic hierarchy process(AHP)and other research methods.Relevant lecture of eutrophication model was analyzed by visualization analysis software,and the eutrophication model evaluation was conducted based on case study.The main achievements are as follows:(1)Through literature research,a set of standardized surface water quality model certification system including model certification standards and processes is proposed,and a set of surface water quality model preliminary evaluation system including five layers of evaluation indexes is designed.The evaluation indexes of model scientificity and software performance is included in the preliminary model evaluation system.(2)Based on Cite Space,visualization analysis software,the research hotspots and development trends of eutrophication model in recent ten years were summarized.The common eutrophication model attribute table was summarized,the tendency of eutrophication model development from mono-type to diversity and from simplicity to complexity was found,and the literature co-citation,cooperation network and the phenomenon of co-word was analysed in detail.(3)Based on the application scenarios of Hongze Lake eutrophication simulation,the surface water quality model preliminary evaluation system was applied,the evaluation indexes suitable for specific scenarios were selected,and a set of model evaluation system for eutrophication application was proposed.Expert evaluation and AHP were used to determine the index weight and specific scoring method of each layer.Three common eutrophication models(EFDC,WASP and Delft3D)were evaluated and compared.The results show that EFDC model with the highest score is the most suitable model in the eutrophication scenario of Hongze Lake.(4)The basic data of Hongze Lake such as inlow data,water level,water quality data and meteorological data was collected,the EFDC modeling software was used to build the eutrophication model of Hongze Lake,and model parameters calibrattion and verification was conducted.Model validation results showed that dissolved oxygen and water temperature simulation results shows good fitting degree with measured data,but a certain amount of error exists between simulation results andmeasured data of total nitrogen and total phosphorus.All in all,the basic trend of hydrodynamic and water quality processes of Hongze Lake can be reflected by the eutrophication model results.The spatial and temporal distribution of TN and TP in Hongze Lake was summarized by analyzing the simulation results.