Typical Urban Drainage Pipe Network And Non-Point Source Pollution Load In Northern Anhui Plain

With the acceleration of urbanization,the proportion of hardened cushion surfaces has gradually increased,resulting in an increase in surface rainfall runoff.Rainfall runoff washes toxic and harmful substances produced by human activities into the water body,which not only pollutes the environment,but also threatens human physical and mental health.Therefore,the control of non-point source pollution is imminent.Non-point source pollution cannot be monitored at a fixed point in time and space,and the data acquisition is complicated,which makes it difficult to control.In recent years,the use of computer models to quantitatively simulate surface source pollution has become the mainstream and effective technical means to strengthen the research and application of surface source pollution models.The prediction and control of surface source pollution are of great significance.This paper takes a certain area of the North Anhui Plain as the research area,considering the smooth terrain,insufficient hydrodynamics,and poor surface runoff mobility in the research area,resulting in the inability of rainwater to be discharged into the receiving water body in time,which aggravates urban waterlogging and the accumulation of water pollutants.Therefore,this study uses Arc GIS software to spatially analyze and process the pipe network and elevation data of the research area,extracts the required data and imports it into SWMM,establishes a SWMM model,and analyzes the research area from the four aspects of surface production convergence,pipeline network transmission,pollutant accumulation erosion and low impact development.The domain conducts simulation research and puts forward corresponding countermeasures.The main contents and conclusions of the study are as follows:(1)Establish a SWMM model in the research area,combine the measured rainfall data,use the runoff coefficient method to determine the model parameters,and adjust the value of each parameter in the process.The rate determination results show that the coefficient of variation under different rainfall reproduction periods is less than 15%,indicating that the model conforms to the situation of the research area.(2)The SWMM model was used to simulate the operation of the drainage network in the study area under different return periods,and to simulate the real-time operation of the drainage network by simulating the dynamic changes of pipe overload,node overflow,and discharge runoff characteristics of the drainage network,in order to find out the problems of the drainage system in the study area.The simulation results show that most of the rainfall in the study area is converted into surface runoff,and with the increasing intensity of rainfall,the pipe and node overloads keep increasing,and the load on the pipe network system becomes larger,and the optimization methods of adopting sunken green areas and expanding pipe diameters can actually reduce the flooding in the study area.(3)The SWMM model was used to study the non-point source pollution load under different rainfall intensity and different land use types in the research area,simulate the pollutant production volume and pollution production process of each pollutant,and predict the pollution control effect in the research area through the pollutant control measures of different schemes.The simulation results show that the total non-point source pollution load emitted by the research area is positively related to the rainfall intensity,and there are far more pollutants emitted from commercial land and residential land than green space.After the adoption of surface source pollution storage tank and LID measures,the effect of reducing the total runoff and the removal of various pollutants is obvious.Figure[24] table[30] reference[125]...