City-level Environmental Footprints Accounting And Linkage Analysis For Water-carbon Nexus In Guangdong Province

Guangdong province,as a core province for economic development in South China and even China in the coming decades.Carbon emissions induced by energy consumption and water scarcity have become the key factors to restrict its sustainable development.With the deepening of trade integration,the developed cities imported a large amount of goods and services through trade to meet their own consumption needs,and outsourced the water resources and carbon emissions generated in the production process to other less developed cities.At the same time,since the carbon emission system and the water resource system in Guangdong Province are in a highly complex network system,the problem in any one system will lead to problems in the whole water-carbon nexus system,these two elements are intertwined and form a complex industrial linkage along the industrial chain.Therefore,it is of great significance to coordinate the complex interdependence between water and carbon in Guangdong Province by considering the coupling mechanism in the socio-economic system for the water conservation,emission reduction and green sustainable development of the industrial chain.In this study,by constructing a city-province nested multi-regional input-output table in 2015,an environmentally extended multi-regional input-output model is used to account for the carbon and water footprints of each city in Guangdong Province and to examine the traderelated carbon and water transfer patterns between cities and others in China.On the basic,conducting the industry linkage analysis to identify the role of each economic sector in water consumption and carbon emission of each city in Guangdong Province.Main findings include:（1）The total carbon footprint of Guangdong Province in 2015 was 347.65Mt,and the carbon footprint of different cities showed significant differences,while the carbon footprint was highly concentrated in the Pearl River Delta urban agglomeration,accounting for about 77.3%of the total carbon footprint,and the per capita carbon footprint and carbon footprint intensity also differed significantly.In terms of final demand categories,large scale infrastructure was the largest driver factor.In terms of sectors,Production and Supply of Electricity and Steam,Heavy Industry and Service Industry contributed the most of the carbon footprint.Meanwhile,the direction of the trade-embodied carbon emission between cities occurs mainly with the Pearl River Delta urban agglomeration.（2）The total water footprint of Guangdong Province in 2015 was 360.63 billion m3.The water footprint,per capita water footprint and water footprint intensity showed significant differences among different cities.In terms of final demand categories,urban consumption is the largest driver factor,while the sectoral perspective shows that Agriculture,Light Industry and Service Industry contribute the most of the water footprint.We also find that the virtual water transfers have a significant effect on regional water footprints and move water allocations in the direction of regional consumption,with virtual water flows moving from relatively less developed regions to relatively developed regions.This increased the inequality between regions.（3）Maoming,Zhongshan and Jieyang were main water-carbon nexus nodes for the net forward linkage,which indicated that these cities export a large amount of embodied carbon emission and virtual to meet the demand of other urban economic setors;Shenzhen,Guangzhou and Dongguan are the main water-carbon nexus nodes for the net backward linkage,which indictes that these cities import a large amount of embodied carbon emission and virtual water from other sectors to meet their demand.Finally,based on the abover findings,the policy suggestions were proposed:from the perspective of inequality among cities,a collaborativer water saving and emission reduction mechanism should be established;From the supply-side perspective,the production structure of imported sources should be adjusted to bring into play the potential of structural optimization for water saving and emission reduction;From the demand-side perspective,by encouraging green consumer behavior,reducing food waste et.al,thus contribute to the overall water saving and emission reduction effect.The findings of this study could provide a solid foundation for the allocation of responsibility for water saving and emission reduction at the urban scale in Guangdong province and help policymakers to develop relevant cross-regional water saving and emission reduction measures.