成渝城市群陆地碳排放时空变化及效应研究

Spatio-temporal Changes and Effects on Terrestrial Carbon Emission in Chengdu-Chongqing Urban Agglomeration

碳达峰和碳中和是中国立足于经济发展阶段和全球可持续发展要求提出的一项战略目标。开展县级尺度土地利用碳排放研究对指导区域实现“双碳”目标具有重要意义。文章以成渝城市群为研究对象,基于2000-2020年土地利用数据、统计年鉴数据和夜间灯光遥感数据,探究成渝城市群碳排放和碳生态效应,并对碳生态压力进行评价。结果表明:(1)2000-2020年成渝城市群土地利用净碳排放呈增长趋势,年均增长289.90万t,且增速逐年减缓,主要碳源为建设用地,总体呈增长状态,年均增长291.70万t;林地是主要碳汇,呈缓慢增长。(2)碳源和碳足迹主要集中在成都市和重庆市主城区范围,部分分散在各地级市中心城区,碳汇主要分布在成渝城市群外围高山丘陵区,包括川西高原的部分区县、川东平行岭谷和重庆部分山区。(3)研究区总体呈碳赤字,碳生态承载力总体变化不大,碳足迹和碳赤字都呈增长趋势,年均增长率分别为9.78%和12.18%。(4)高度碳生态承载力区主要分布在成渝城市群外围区县,高度碳生态压力区集中在以成都市和重庆市主城区为核心的区域以及各地级市主城区;研究区内部分区县碳生态压力有所缓解,但整体上陆地生态系统碳循环压力依旧很大,此外其余区县生态压力均呈现不同程度的增强。

Carbon peaking and carbon neutrality is a strategic goal put forward by China based on the stage of economic development and the requirements of global sustainable development.It is of great significance to carry out research on carbon emissions from land use at the county level to guide the region to achieve the"double carbon"goal.Taking ChengduChongqing urban agglomeration as the research object,based on 2000-2020 land use data,statistical yearbook data and nighttime light remote sensing data,this study explores the carbon emissions and carbon ecological effects of Chengdu-Chongqing urban agglomeration,and evaluates the carbon ecological pressure.The results shows that:from 2000 to 2020,the net carbon emission of land use in the urban agglomeration shows an increasing trend,with an average annual growth of 2.899 million tons,and the growth rate slows down year by year.The main carbon source is construction land,which shows an overall growth state,with an average annual growth of 2.917 million tons.Forest land is the main carbon sink,growing slowly.The carbon sources and footprints mainly concentrate in Chengdu and the main urban areas of Chongqing,and some scatter in the core urban areas of local cities.The carbon sinks mainly distribute in the mountainous and hilly areas outside the urban agglomeration,including some counties in the Western Sichuan Plateau,Ridge and Valley Province of Chuandong and some mountainous areas in Chongqing.Chengdu-Chongqing urban agglomeration presents a carbon deficit as a whole,and the overall carbon ecological carrying capacity has little change.The carbon footprint and carbon deficit shows an increasing trend,with an average annual growth rate of 9.78%and 12.18%,respectively.The high carbon ecological carrying capacity areas of the urban agglomeration mainly distribute in its peripheral counties,and the high carbon ecological pressure areas concentrate in the areas with Chengdu and the main urban areas of Chongqing as the core,as well as the main urban areas of cities at all levels;The carbon ecological pressure of counties has eased in the study area,but on the whole,the carbon cycle pressure of terrestrial ecosystem is still great.In addition,the ecological pressure of other counties has increased to varying degrees.