Study On Emission Trading Scheme Of Shaying River Basin Based On Interval Optimization Theory

With the increasing pollution of the water environment,rivers in China are affected to varying degrees.Emission trading is an effective means to solve the conflict between regional development and environmental protection,so it is necessary to introduce an emission trading system.However,there are many uncertain factors in the process of emissions trading,such as flow rate,flow velocity,pollutant quality,water concentration,pollution capacity and so on.These factors are in a dynamic change,which will have a great impact on emissions trading when calculated as a fixed value.Based on the above reasons,emissions trading needs to be based on the dynamic changes of rivers,take full account of the impact of uncertainty,and apply uncertainty theory to optimize emissions trading schemes.Based on the analysis of the research progress of emission trading at home and abroad,this paper selects the Shaying River Basin as the research area,and conducts in-depth research on the influence of emission trading between point sources and non-point sources under different inflow conditions.The main research contents and conclusions are as follows:(1)MIKE 11 model was used to simulate the water quantity and quality process of the Shaying River.On the basis of the MIKE 11 model,the model test was carried out according to the pollutant load data of each discharge outlet of the Shaying River.The pollutant carrying capacity threshold of each water function area can be obtained by achieving the target concentration of water quality.The results show that the threshold of water pollution capacity is the largest in the wet year and the smallest in the dry year.(2)Through different methods to calculate the point source and non-point source of pollutants in the river,on the basis of the relationship between the number of pollutants in the river and the threshold of pollution capacity to determine the number of pollutants in the whole basin;secondly,the initial allocation of non-point and point source is carried out according to the allocation method of initial emission rights.The point source is allocated according to the government-water function areaindustry,and the non-point source is allocated according to the government-water function area.Finally,according to the relationship between the initial emission rights,emission reduction potential and pollutant discharge into the river,combined with certain principles,the tradeable emission rights threshold of point source and non-point source can be obtained.(3)Considering the influence of different inflow conditions on the emission trading process of the Shaying River,different inflow conditions such as wet year,normal year and dry year are introduced.By constructing a multi-objective optimization model based on interval programming,an interactive algorithm and linear weighting method are used to solve the optimal solution of an emission trading process,and the optimal scheme and the worst scheme in the optimal results can be obtained.After multi-objective optimization,the economic benefit after emission trading is increased compared with that before trading,and the economic benefit is the largest in a wet year,the middle in a normal year and the smallest in a dry year.Environmental capacity surplus is: wet year > normal year > dry year;the water quality compliance rate also increased after the emission trading.