| Quantitative accounting of water pollution capacity in waters is an important prerequisite for formulating and implementing water pollution control,and it is also the fundamental basis for total water pollutant control.The water diversion project has a significant impact on the original hydrological situation and the discharge load conditions of the rivers in the receiving area.Carrying out the analysis of the applicability of the pollution-retaining capacity calculation model is of great significance to accurately verify the water-retaining capacity of the water body.This paper takes the intake area of the Han to Wei River project as the research object,proposes a new modified model based on the analysis of the applicability of different models,and analyzes the impact of the model parameter changes on the calculation results of the pollution energy,It is finally applied to the verification of pollutant holding capacity and pollutant reduction in different periods of the water receiving area.The main research results are as follows:(1)Select the typical river section to compare and analyze the calculation results of different models of pollutant holding capacity.The model selects the regulation model,the segment head control model and the segment end control model.On the basis of the regulation model,a revised model for generalizing the remaining pollutant intake into the river to the midpoint of the river is proposed.The calculation results of the pollutant holding capacity show that the revised model generalizes the remaining pollutant loading into the river to the midpoint of the river section,and fully considers the utilization of the remaining pollutant load discharge to the river self-purification conditions.The water-receiving area can flexibly determine the remaining pollutant holding capacity of different river sections,which helps the verification of pollutant holding capacity and the control of total pollutants to a certain extent.(2)The influence degree of pollutant generalization method,hydrological conditions and comprehensive degradation coefficient of pollutants on the calculation results of pollutant holding capacity was analyzed.The outlet generalization method shows that the apex generalization calculation has the largest result of the pollutant holding capacity,and the uniform generalization is close to the midpoint generalization calculation result,slightly smaller than the midpoint generalization calculation result;the design flow condition result shows that the water receiving area It is reasonable to select the average flow rate in the dry season in the last ten years for the hydrological conditions of the river section.For the section of the water-receiving area where the flow rate of the river is low,the sensitivity of the design flow condition to the calculation results of the pollutant holding capacity is greater than the comprehensive degradation coefficient of pollutants.(3)The revised model was used to account for the pollutant holding capacity of the intake area of the Han to Wei project at different planning levels,and the impact of changes in the amount of backwater from urban industrial and domestic water consumption on the calculation results of the pollutant holding capacity of the intake area was analyzed.Based on the calculation results of the pollution-receiving capacity of each calculation unit,the equal proportion reduction plan was selected to reduce the pollutants at the sewage outlet of the river. |
