An Analysis On Industrial COD Discharge In Jiangsu Province Based On Semi-parametric Model And LMDI Method

The relationship between the economy and pollution discharge has always been a concern for researchers and policy makers for years.It's shown that the relationship is different in separate areas for specific contaminant.As a result,targeted policy should be made on the basis of the recognition of this relation.Since 2000,the effect has been seen due the implement of environmental protection policy.As the increase of economy starts to get slow,the possible relationship between the environment and pollution discharge in the new stage arouses attention,especially for eastern areas in China whose economic development is ahead and can be referred for areas in the middle and west.Industrial water pollution is one of the main sources of water pollution,which not only leads to the decline of water environment quality,but also leads to direct economic loss.Although industrial wastewater discharge has been declining in recent years,industrial water pollution is still one of the limited factors of social and economic development in Jiangsu province.Industrial wastewater has a variety of pollutants.COD is one of the most representative contaminant.It's important to fully understand the relationship between industrial COD discharge and economic development and its influence factors in order to predict pollutant emission trends and effectively make reduction targets in Jiangsu province.This study simulates the relationship between the economy and the environment using panel data from 1991 to 2015 in Jiangsu province.The research chooses semi-parameter fixed effects regression model based on STIRPAT model which introduces economic factors,demographic factors,water use intensity as explainable variables.To understand the mechanism of industrial COD discharge,the research also uses LMDI decomposition method which decomposes industrial COD discharge into economic scale effect,structural effect and technological effect.And it further decomposes into technological effect into technological effect I which represents the source treatment,technological effect ? which reflects the process control and technological effect III which is representative of governance at the end.The thesis tries to explore the size and trends of separate effect in different areas of the province and analyzes the differences between them.It's found that there is an inverted u-shaped curve relationship between industrial COD discharge and economic development in Jiangsu province and the turning point appears when GDP per capita is around 88000 yuan,which means industrial COD discharge increases with the rise of GDP per capita and will reduce with the increase of GDP per capita when beyond a certain level of economic development.At present,industrial COD emission in Jiangsu province is still at a high level and there is still some space for reduction,especially for the middle and northern part of Jiangsu.In addition,it shows that the economic scale factors and the technical factors have a great impact on the industrial COD emission while economic structure effect is very limited.At present,reduction has entered the bottleneck period in terms of the technological effect.As a result,technological innovation needs to cover the whole process of industrial COD management which can start from the process management.The overall trend of separate effects is consistent in different areas of Jiangsu,but differences still exist.Those less developed areas take the road of green ecological development with the advantage of later development and the help of technological improvement.In conclusion,this thesis puts forward four suggestions for policy makers.First,it's necessary to develop pointed environmental economic strategies in consideration of the differences among regions when it comes to the relationship between the economy and pollution emissions.Second,the quality of economic development and the economic structure should be improved.Third,the emphasis of water pollution control needs to turn to improve water quality.Fourth,the water pollution control cover the whole process of industrial COD discharge.