Study On Dynamic Water Environment Capacity Of Main Inlet Branches Of Guanting Reservoir

Yanghe and Sanggan river are the main rivers of Youngding River in the river-sea system.Yanghe and Snaggan river converge into Guanting Reservoir near Huailai,Hebei Province.The two rivers account for 92.3% of the total discharge,and are the two main tributaries of Guanting Reservoir.Based on the division of water function in Hebei Province,the Yanghe River and Sanggan River are taken as the research areas.Through the principal component analysis of Yanghe and Sanggan River,the water quality indexes of the two rivers are optimized,the main factors are selected,the main pollution factors of Yanghe and Sanggan River are determined by the method of over-standard multiple,and the dynamic water environmental capacity is calculated.The main contents and conclusions of this paper are as follows:(1)The reservoir capacity and basin scope of Guanting Reservoir are summarized.The geographical scope,climate,hydrological conditions,administrative area and socio-economic conditions of Yanghe and Sanggan River basins,the main tributaries of the reservoir,are expounded.The urbanization and economic situation of Zhangjiakou area are also described.(2)The reservoir capacity and basin scope of Guanting Reservoir are summarized.The geographical scope,climate,hydrological conditions,administrative area and socio-economic conditions of Yanghe and Sanggan River basins,the main tributaries of the reservoir,are expounded.The urbanization and economic situation of Zhangjiakou area are also described.(3)After completing the optimization of the water environment evaluation index,the water quality index of the study area is evaluated by the method of exceeding standard multiple.Through weighting the index of each section in the study area,the pollutants for calculating the water environment capacity are determined,the design data of each section in the study area and the background concentration value of water quality are determined,and the water quality objectives and pollutants of each region are determined on the basis of the water function zoning of Hebei Province.Degradation coefficient.The calculation models of river water environmental capacity,applicable conditions of various models and calculation formulas of various models are introduced.According to the actual situation of the study area,one-dimensional water environmental capacity model is suitable for selection.(4)Using one-dimensional water quality model to calculate the ideal water environmental capacity,the COD environmental capacity of Yanghe Zhangjiakou Development and Utilization Zone is 890.05 t/a,and the ammonia nitrogen environmental capacity is 47.93 t/a;the COD environmental capacity of Yanghe Zhangjiakou Buffer Zone is 458.45 t/a,and the ammonia nitrogen environmental capacity is 18.57 t/a;the COD environmental capacity of Sanggan River Zhangjiakou Development and Utilization Zone is 617.47 t/a,and the ammonia nitrogen environmental capacity is 35.58 t/a;and the Sanggan River Zhangjiakou Development and Utilization Zone is The environmental capacity of the mouth buffer is 1024.28t/a and that of ammonia nitrogen is 57.27t/a.The ideal dynamic environmental capacity of the study area is recalculated without considering the inflow situation of the upstream water body and the environmental capacity of the downstream water body.The water environmental capacity changes dynamically in a year.Because the hydrological and water quality conditions are different in different months.Residual dynamic water environmental capacity changes dynamically in a year.The residual environmental capacity of COD in Yanghe-Xiangshuibao section is 67.81-244.73t/month,the maximum value of ammonia nitrogen is 5.05 t/month and the minimum value is-1.20 t/month;the variation range of COD capacity in Yanghe-Xiangshuibao-Guanting reservoir is 121.33-314.88 t/month,the maximum value of ammonia nitrogen is 6.74 t/month and the minimum value is 1.27 t/month;the environmental capacity of COD in Sanggan-Yangyuan section is 74.43-153.43t/month,and the maximum value of ammonia nitrogen is 3.00 t/month,the maximum value is 1.27 t/month.The small value is 0.51t/month;the COD of Yangyuan-Yangyang Estuary of Sanggan River ranges from-8.97 to 358.54t/month,and the ammonia nitrogen ranges from-3.69 to 6.77t/month.