Study On Hydrodynamic-water Quality-Water Ecology Model And Joint Control Schemes Of River Network In Central Area Of Suzhou

Suzhou is a typical plain river network area,with dense and intricate river network.In recent years,increasing pollution load has caused many water environment problems in Suzhou,and the water quality of the river has deteriorated.In order to improve the water environment of urban river network,the water quality of the river network in the central urban area of Suzhou was monitored,the hydrodynamic-water quality-water ecological model is established,and the relevant regulation and control schemes were analyzed.According to the general situation of water resources and water pollution in the central urban area of Suzhou,the current situation of water environment in the region was analyzed,and the main problems were identified.It was concluded that ammonia nitrogen was the primary pollutant,and the exceeding standard was very serious in April,followed by May to August.The total phosphorus was the secondary pollutant,and the exceeding standard was serious in July and August,which was also the period of algae bloom..The hydrodynamic-water quality-water ecological model was established based on EFDC model.The parameter calibration and model validation was conducted to ensure the accuracy of the model.The hydrodynamic model took the water level as the index,the mean error is less than 3%,and the average relative deviation is above 0.96,meeting the error requirements.The calibration and verification of water quality are based on permanganate index,ammonia nitrogen and total phosphorus.The mean error and average relative error basically meet the requirements,and the parameters were suitable for the river network in the study area.The water quality model is reliable.The chlorophyll is used as the indicator in the water ecological model.In the summer when algae control is needed,the simulation process is acceptable and can be used for the simulation of subsequent regulation schemes.April and July were selected as two basic scenarios to simulate and analyze water environment regulation schemes.Water power regulation,water quality control,ecological control,as well as the joint control scheme were simulated and analyzed respectively,finally it was found that the joint control scheme is more effective than their own separate regulation,it can make the water quality of rivers in the the research area reaches ?class water standard,and chlorophyll is sharply cut,the water quality and water ecological environment is improved.