Temporal And Spatial Evolution Characteristics Of Major Pollutants Emissions In The Yangtze River Economic Belt

In recent years,the level of economic development in the Yangtze River Economic Belt has been continuously improved,and accompanied by a series of environmental problems.The pressure on ecological environment protection is enormous.Taking 2017 as an example,the total sulfur dioxide emissions in the Yangtze River Economic Belt totaled 3,219,600 tons,accounting for 37%of the total national emissions,4.41 million tons of total nitrogen oxide emissions,accounting for 35%of the total national emissions,and 62.3 million tons of ammonia nitrogen emissions.47%of the total national emissions and 4,745,800 tons of chemical oxygen demand,accounting for 48%of the total national emissions.The issue of pollutant emission reduction has become the focus of domestic scholars and the govemment.As an important economic strategic area of China,the Yangtze River Economic Belt is accompanied by a large amount of pollutants in the development process.Therefore,it is significance to study the characteristics of pollutant discharges in this area,which is helpful to formulate reasonable emission reduction measures and promote emission reduction work.Based on the two aspects of pollutant discharge and emission intensity,this paper studies the temporal and spatial evolution characteristics of pollution emissions in the Yangtze River Economic Belt.Taking sulfur dioxide,nitrogen oxides,chemical oxygen demand and ammonia nitrogen as the main pollutants,this paper analyzes the spatial distribution of major pollutant discharges,unit GDP emission intensity,unit construction land discharge intensity and unit land area emission intensity in the Yangtze River Economic Belt.Characteristics and influencing factors.Secondly,based on the pollutant discharge data,the spatial auto-correlation method is used to reveal the spatial pattern evolution characteristics of pollutant discharge in the Yangtze River Economic Belt from the provincial level and the municipal level,and attempts to propose measures for pollutant emission reduction are proposed.The main conclusions are as follows:1)The emissions of atmospheric pollutants in the Yangtze River Economic Belt in 2005-2017 showed a slow downward trend,and the water pollution emissions increased first and then slowed down.The total amount of water pollutants discharged by provinces and cities decreased slightly after the increase in 2011;the degree of pollutant emission reduction in different provinces and cities was different,and the decline in the central urban agglomeration and the Yangtze River Delta region was relatively large,with reductions of more than 50%.In the 2011-2017 period,the reductions in sulfur dioxide emissions in Shanghai,Zhejiang,and Hunan were 92.29%,71.23%,and 68.70%,respectively.2)The contribution of total pollutant discharges in the Yangtze River Economic Belt is large.Guizhou and Jiangsu have a large contribution rate in the total sulfur dioxide emissions of the Yangtze River Economic Belt.In 2011,sulfur dioxide emissions in Guizhou and Jiangsu accounted for 14.33%and 13.68%,respectively.In 2017,Guizhou and Jiangsu accounted for 21.35%and 12.76%,respectively;The largest contribution rate of total emissions is Jiangsu,accounting for 19.4%in 2011 and 20.57%in 2017.There are three extreme points in the total amount of water pollutants discharged from the Yangtze River Economic Belt,namely,Jiangsu in the eastern region,Hunan in the central region,and Sichuan in the western region.In 2017,the total chemical oxygen demand in these three provinces The total amount is about 32.1%.3)The emission intensity of atmospheric and water pollutants in the Yangtze River Economic Belt has a decreasing overall trend.The emission intensity of atmospheric pollutants per unit of GDP in the Yangtze River Economic Belt is significantly different,and the eastern region is significantly smaller than the central and western regions.The areas with high emission intensity of sulfur dioxide in the Yangtze River Economic Belt are concentrated in Guizhou and Yunnan in the western region,and the emission intensity in the Yangtze River Delta region is small.In 2017,the unit GDP emission intensity of Guizhou was 8.72kg/10,000 yuan,which is 8 times of the sum of Shanghai,Jiangsu and Zhejiang.4)The emission intensity of atmospheric pollutants in the Yangtze River Economic Belt has gradually slowed down,and the trends in the eastern,central and western regions are slightly different.There is no significant change in the emission intensity level in the western region.Sichuan and Yunnan have large land areas,accounting for 24%and 19%of the total area of the Yangtze River Economic Belt,respectively.The contribution rate of pollutant emissions is 6%-10%,and the emission intensity is relatively small.The emission intensity of the sulfur dioxide unit in the eastern and central regions is gradually reduced due to the obvious effect of pollutant emission reduction.2011-2017 The emission intensity of NOx units levels in the western and eastern regions are not significantly changed,and the emission intensity in the central regions is gradually decreasing.5)There is difference in the overall change trend of the emission intensity of construction land for atmospheric and water pollutants in the Yangtze River Economic Belt.The emission intensity of construction units of atmospheric pollutants has gradually decreased.The emission intensity of construction sites of sulfur dioxide in the Yangtze River Delta has been decreasing.Compared with 2010,the area of construction land in Shanghai and Jiangsu has not increased by more than 10%.The total reduction of sulfur dioxide emissions exceeded 60%;the emission intensity of construction units of water pollutants was a turning point in 2015,showing a trend of increasing first and then decreasing.6)The spatial agglomeration characteristics of provincial-level pollutant discharge intensity in the Yangtze River Economic Belt are significant,and the spatial distribution of industrial pollution emissions at the prefecture-level level is large.The GDP intensity of the comprehensive pollutant discharge at the provincial level in the Yangtze River Economic Belt has a spatial positive correlation,the Moran Index is positive,and there is a certain degree of agglomeration effect;there is a global spatial autocorrelation phenomenon in the total amount of sulfur dioxide emissions from prefecture-level industries.The spatial distribution of industrial wastewater and industrial smoke dust emissions in the Yangtze River Economic Belt is characterized by high east and low west,and the areas with the highest industrial wastewater discharge are distributed in Jiangsu and Zhejiang.7)Population size,per capita GDP,industrial structure and economic growth rate are the main influencing factors of pollutant emissions in the Yangtze River Economic Belt.Among them,per capita GDP has a positive and significant impact on the emission of sulfur dioxide and nitrogen oxides,which indicates that the current emissions of atmospheric pollutants in the Yangtze River Economic Belt are closely related to the level of economic development.The overall model of chemical oxygen demand estimates that the resident population and economic growth rate at the end of the year have a greater impact on the chemical oxygen demand emissions of the Yangtze River Economic Belt.