城市集群土地利用碳足迹时空分异及响应特征

Spatial-temporal Differentiation and Response Relationship Regarding Land-use Carbon Footprint in Urban Clusters

该文基于土地利用碳足迹模型,对比分析长江中游城市群和成渝城市群碳足迹时空分异特征,并利用回归模型明晰社会经济等因素与碳足迹水平之间的响应关系。结果表明:长江中游城市群2000-2015年的碳吸收由11.18×10^(6)t增至11.21×10^(6)t,成渝城市群则由2.84×10^(5)t增至2.86×10^(5)t,林地的碳吸收占比最大(大于95%)。长江中游城市群和成渝城市群碳排放量整体呈逐年上升趋势,其峰值分别为2.96×10^(8)t(2011年)和2.41×10^(8)t(2013年);城市群碳排放来源差异较大,长江中游城市群以煤炭(36.7%)和原煤(33.6%)为主,成渝城市群则为原油(31.2%)和原煤(36.35%)。长江中游城市群人均碳足迹由0.27 hm^(2)增至0.60 hm^(2)(年增速21.36%),成渝城市群则由0.23 hm^(2)增至0.38 hm^(2)(年增速11.11%);而长江中游城市群的人均碳承载呈轻微的下降趋势,由0.026 hm^(2)下降至0.021 hm^(2),成渝城市群则呈现先上升后下降的趋势,2003年达到峰值(0.0157 hm^(2))。城市群间碳足迹响应关系存在明显差异,其中,调整产业结构和增加财政科学事业费支出能够降低长江中游城市群碳足迹水平,而城镇人口比重和人均生产总值对碳足迹具有正向影响;严格控制农业化肥使用量和人口密度则能够显著降低成渝城市群碳足迹。通过与京津冀城市群碳足迹对比,结果表明京津冀城市群碳压力(82.94)远大于长江中游城市群(40.45)和成渝城市群(67.13)。

In this study,a land-use carbon footprint model was used to comparatively analyze the spatial-temporal differentiation characteristics of carbon footprint in two great urban clusters,i.e.the Triangle of Central China(TOCC)and the Chengdu-Chongqing Urban Agglomeration(CCUA),and then the response relationship between socio-economic factors and carbon footprint was clarified by using of the regression models.Consequently,the analysis presented that carbon absorption in TOCC and CCUA increased from 11.18×10^(6)t to 11.21×10^(6)t and from 2.84×10^(5)t to 2.86×10^(5)t during the study period(2000-2015),respectively,wherein,the forest land accounted for more than 95%of the carbon absorption.The overall carbon emissions of TOCC and CCUA tended to rise:carbon emission peak value of TOCC up to 2.96×10^(8)t in 2011,and that of CCUA2.41×10^(8)t in 2013;as for carbon-emission source,there were rather discrepancies between TOCC and CCUA:the carbonemission source of TOCC was coal(36.7%)and raw coal(33.6%),whereas that of CCUA being crude oil(31.2%)and raw coal(36.35%);and as to the carbon footprint,TOCC and CCUA both increased:TOCC from 0.27 hm^(2)/cap to 0.60 hm^(2)/cap(average annual growth of 21.36%),and CCUA from 0.23 hm^(2)/cap to 0.38 hm^(2)/cap(average annual growth 11.11%).However,the per capita carbon carrying capacity of TOCC displayed a trend of slight decreasing:from 0.026 hm^(2)to 0.021 hm^(2),while that of CCUA appeared a trend,i.e.increased firstly and then declined with a peak value in 2003(0.0157 hm^(2)).Moreover,there existed apparent spatial differences in the terms of the response relationship of carbon footprint between the two urban clusters,among others,the industrial structure adjustment and increased financial science expenditure could reduce carbon footprint in TOCC,whereas the growth of urban population density and per capita GDP would add the carbon footprint.As for CCUA,the strict control of agricultural chemical fertilizer application and population density were the essential measures to reduce carbon footprint.In addition,by comparison with carbon footprint of the Beijing-Tianjin-Hebei Urban Agglomeration(BTHUA),it can be seen that carbon pressure(as to the“carbon pressure index”)of the BTHUA(82.94)is by far greater than that of TOCC(40.45)and CCUA(67.13).