Study On Water Pollution Control Of Sanhekou Reservoir Basin Based On System Dynamics

Sanhekou Reservoir,as one of the two important water sources of the Han-Ji-Wei water diversion project,plays a very important role in alleviating the water resources problem in Guanzhong area and improving the ecological environment of the Weihe river basin.This paper takes the Sanhekou reservoir basin as the research object,constructs the dynamics model of the water pollution control system of the Sanhekou reservoir basin through the method of system dynamics,and takes 2015 as the base year to carry out historical test and sensitivity analysis of the model After the test,based on the method of scenario analysis,five different scenarios were designed for simulation analysis.Finally,according to the simulation results and the actual situation of Sanhekou basin,reasonable measures and suggestions are put forward.Through the study of this paper,the main conclusions are as follows:(1)The SD model of water pollution control system in Sanhekou reservoir basin is constructed.By using the method of system dynamics and combined with statistical data,the SD model of water pollution control system in Sanhekou reservoir basin is established,and the system is divided into three subsystems:population,agriculture and water pollution.The historical test and sensitivity analysis of the constructed model are carried out.The results show that the model is effective,can better reflect the actual system,and can be used for system analysis and prediction.(2)The changing trend of water pollution control in Sanhekou basin under different scenarios is simulated and analyzed.According to the specific conditions of the Sanhekou reservoir area,five scenarios are designed,which are scheme 1 for maintaining the status quo,scheme 2 for economic growth,scheme 3 and scheme 4 for environmental protection,and scheme 5 for coordinated development.Each scheme is simulated and analyzed respectively,and the results show that under the development of scheme 1,the pollutant discharge of the basin is increasing year by year,and the inflow of COD and ammonia nitrogen in 2030 will increase by 12.4%and 15.1%compared with the current situation.Option 2 increases the speed of economic development on the basis of option 1.Compared with plan 1,the number of livestock and poultry farming will increase slightly in 2030,and the urbanization rate will increase,but the emissions of COD and ammonia nitrogen will further increase,and the water pollution will be more serious.It can be seen that it is not advisable to maintain the status quo without further pollution control,or only pay attention to economic development.From the point of view of domestic pollution source control,under the development of option 3,the river inflow of COD and ammonia nitrogen in 2030 decreased by 17.4%and 24.4%respectively compared with scheme 1.From the point of view of livestock and poultry pollution source control in option 4,compared with option 1,the river inflows of COD and ammonia nitrogen decreased by 8%and 5.4%respectively in 2030.At the same time,compared with scheme 1 and 2,the pollutant emissions of scheme 3 and scheme 4 have been reduced to a certain extent,and the effect of pollution control has been improved to a certain extent.But these two programs have slowed down economic growth.Option 5 integrates the situations of options 2,3 and 4,which not only ensures high economic development,but also takes into account environmental protection.In 2030,the COD inflow into the river increased by 3.6%compared to scheme 3,but the pollutant emissions were lower than those of scheme 1 and 2.Therefore,scheme 5 is a better scheme for the coordinated development of social economy and environment in the Sanhekou basin.(3)The control measures and suggestions of water pollution in Sanhekou reservoir basin are put forward.Based on the results of simulation analysis and the actual situation,reasonable water pollution control measures and suggestions were put forward from three pollution sources:urban life,rural life and livestock and poultry breeding.Urban life adopts the treatment mode of building centralized sewage treatment plants to improve the rate of domestic sewage treatment,rural life adopts the treatment methods of nano-management,centralized treatment and decentralized treatment,livestock and poultry breeding adopts measures such as developing ecological breeding and strengthening publicity.To ensure the safety of water environment and water quality in the Sanhekou basin.