基于随机森林模型的我国县域碳排放强度格局与影响因素演进分析

为了研究县域碳排放强度空间格局及其关键影响因素的演进规律,在测算2009~2017年我国县域碳排放强度的基础上,通过ArcGIS空间统计模型分析了县域碳排放强度的空间格局,并利用随机森林模型识别了碳排放强度的关键影响因素及其时序演进特征.结果显示:2009~2017年我国县域平均碳排放强度减量波动下降,2017年县域平均碳排放强度为2.02t/万元,仍有较大的削减潜力;县域碳排放强度总体格局呈显著空间自相关,并呈现波动增强趋势;局部格局呈显著的南北和东西分异,热点区呈西进态势,冷点区呈南下北上态势.关键影响因素中省会距离、产业结构、路网密度和人口的重要性高于经济水平、财政收支、绿色专利和开通高铁;时序演进反映,绿色专利、人口总数和经济水平的重要性在提升,而产业结构和人口密度的重要性在下降;其中大部分关键影响因素同碳排放强度呈现非线性响应关系.

County-levelspatial pattern and influencing factors evolution of carbon emission intensity in China:A random forest model analysis

To explore the spatial distribution pattern of the county-level carbon emission intensity and the dynamic change in influencing factors, in this paper, ArcGIS spatial statistical model was adopted to measure and analyze the spatial distribution pattern of the carbon emission intensity from 2009 to 2017. Then key influencing factors and their effects change were identified by the random forest model. As results indicated, the average county-level carbon emission intensity fluctuated and decreased from 2009 to 2017. The county-level average carbon emission intensity was 2.02t/10000 yuan in 2017, indicating a significant potential in carbon emission reduction at county-level. Besides, there was significant and rising spatial autocorrelation in carbon emission intensity, but the spatial correlation varied between north-south and east-west regions. The hot-spot area of carbon emission intensity expanded westward, while the cold-spot area expended both southward and northward. Among the key influencing factors, distance to provincial capital, industrial structure, road network density and population played more important role compared with economic development, fiscal revenue and expenditure, number of green patents and high-speed railway. Green patent, total population, and economic development risen in the importance rankings over time, while industrial structure and population density fallen back in the rankings. In addition, most of factors were non-linear correlated with the county-level carbon emission intensity.