Research On Spatio-temporal Characteristics Of Regional Carbon Sources And Sinks And Carbon Balance Zoning

Global climate change,characterized by climate warming,is a serious challenge to human life and social development.China has proposed the long-term goal of achieving carbon peaking in 2030 and carbon neutrality in 2060 at the 75th session of the United Nations General Assembly."Reducing emissions"and"increasing sinks"are two crucial paths to achieve the goal of them.Estimating carbon emissions and carbon sinks in the Beijing-Tianjin-Hebei,and analyzing the spatial distribution and change trends of carbon sources and sinks will help formulate regionally differentiated carbon emission reduction policies and measures,reduce carbon emissions,and contribute to sustainable development.Most of the previous studies were carried out independently of each other,and there were few studies on the collection of urban carbon sources that comprehensively considered ecosystem carbon sinks and energy emissions.At the same time,most studies on spatial optimization from the perspective of carbon sources and sinks also use the coefficient method,and the estimated carbon sink data lack real-time and spatial differences.Based on the above two points,this paper from the perspective of natural ecosystem and socio-economic system,Firstly,the carbon dioxide from fixed vegetation was estimated based on CASA model and photosynthesis equation,and the carbon dioxide from energy combustion was estimated based on IPCC inventory method and energy statistics data,and the linear model of night light data and energy carbon emissions was constructed.Secondly,by means of statistical methods,trend analysis,Moran’si index and hot spot analysis,the spatial distribution characteristics and change trend of carbon sources and sinks were analyzed.Finally,the carbon sink data estimated by remote sensing was introduced as the base data of carbon balance zoning research,the carbon balance zoning index system was constructed,the carbon balance zone was demarcated,the carbon balance spatial optimization zone was refined according to the strategic objectives of the main functional zone planning,and the low-carbon development direction and strategy of each type of region were proposed,so as to form a set of carbon source sink estimation system and application research of carbon balance zoning.The main conclusions of this study are as follows:(1)Temporal and spatial analysis of carbon sequestration by vegetation.The average annual carbon sequestration of vegetation in the Beijing-Tianjin-Hebei region from 2015 to2020 was 16465.75×10~4t.The results show that in 2020,the total amount of vegetation carbon sequestration reached a maximum of 17356.46×10~4t,and the monthly data during the study period showed a unimodal periodic change.In terms of spatial distribution,the high-value areas are mainly distributed in the Yanshan and Taihang Mountains in the north and west,and the low-value areas are mainly distributed in the central part of the Beijing-Tianjin-Hebei region.The rate of change from 2015 to 2020 shows a trend from increasing to decreasing from west to east.(2)Spatio-temporal analysis of energy carbon emissions.In 2015,2018 and 2020,the overall energy carbon emissions and per capita carbon emissions in the Beijing-Tianjin-Hebei region will gradually decrease.On the municipal scale,the total amount of carbon emissions from energy consumption has gradually decreased,and the per capita carbon emissions have fluctuated and decreased.The average energy carbon emissions of Tianjin and Tangshan are above 20,000×10~4t.Tangshan has the highest per capita carbon emissions and Xingtai has the lowest.At the county level,Binhai New Area has the highest average total carbon emissions(6603.27×10~4t),and Kangbao County the least(19.51×10~4t);per capita carbon emissions are highest in Caofeidian District and lowest in Kangbao County.The trend is different.The counties with faster emission reduction rate are mainly in Handan City,and the counties with faster carbon emission increase are mainly in Tangshan City.The spatial autocorrelation results show that the spatial correlation of carbon emissions in the Beijing-Tianjin-Hebei region is gradually increasing,and the spatial distribution of high-carbon emissions or low-carbon emissions at the county level is closer and tends to be concentrated.(3)Carbon balance zoning.The spatial distribution of ecological carrying coefficient(ESC),net zero emission carbon footprint(CES)and economic contribution coefficient(ECC)at the county level in 2020 was analyzed.The high value of ESC was mainly distributed in the Bashang Plateau mountain region of northern Beijing-Tianjin-Hebei,Yanshan Mountain region of northern Hebei and Taihang Mountain region of western Hebei.High CES values were distributed in coastal cities with high economic development level and urban areas,indicating that economic development was not in harmony with ecological environment development.The ECC of some key development areas and optimized development areas,such as Tianjin,Tangshan city and Qinhuangdao City,is weak,indicating that the energy utilization efficiency of these areas is low and the carbon emission scale is large.A carbon balance zoning scheme was proposed,which defined the carbon sink barrier zone,low-carbon development zone,carbon intensity control zone and high carbon optimization zone.Combined with the strategic objectives of the main functional zone planning,the carbon balance spatial optimization zone was refined,and suggestions for differentiated low-carbon development space optimization based on the main functional zone planning were put forward.