重庆市县域空间土地利用碳排放的时空格局分析

Spatial-temporal Pattern Analysis of Land Use-related Carbon Emissions in Chongqing Based on County Space

为从县域尺度上探讨土地利用碳排放效应,推动区域经济社会低碳转型,构建生态文明建设新格局,以重庆市38个区县为研究单元,基于不同土地利用类型数据,采用直接与间接碳排放估算模型,计算了1997~2015年各区县土地利用碳排放强度,揭示了其时空演变规律,同时采用空间自相关分析方法,探讨了空间关联特征.研究结果表明:①1997~2015年期间重庆市土地利用碳排放总量从1010.06×104t增加到2443.15×104t,其增长趋势划分为缓慢增长、波动增长、快速增长、持续稳定等4个阶段.受复杂地形地貌类型和差异城乡经济社会发展的影响,重度排放集中在主城核心区,中轻度排放集中在主城拓展区、环主城区及区域中心城市,微度排放主要集中在渝东南武陵山区和渝东北三峡库区.②全局空间自相关Moran’s I值呈现先减小后增大的趋势,但总体上处于集聚状态,并且呈现高值集聚状态.局部空间自相关显示高值集聚区域主要位于主城区和环主城区,低值集聚区域主要位于渝东南和渝东北地区,并具有一定的空间路径依赖特征.

This article attempts to discuss the carbon emission effect of land use from the county scale. It will promote the low-carbon transformation of regional economy and society. And this will also benefit to establish a new pattern of ecological civilization construction. Therefore,thirty-eight districts and counties in Chongqing were selected as study objects. Based on land use data,land use-related carbon emissions were estimated using direct and indirect carbon emission models for the period 1997~2015. On this basis,space-time patterns were revealed.Meanwhile,spatial correlation features were identified using a spatial autocorrelation analysis method. The results show that:(1) the total land use-related carbon emissions during 1997~2015 increased from 10 001 600 t to 24 431 500 t,with the trend having four distinct stages:slow,fluctuating,rapid and stable growth. Influenced by differences in the landform types and socioeconomic development of urban and rural areas,heavy carbon emissions were concentrated in core urban areas;moderate and mild emissions occurred mainly in the main urban expansion area,the region around the main urban areas,and in regional hub cities;low emissions were mainly concentrated in the Wuling mountainous area in southeast Chongqing and the Three Gorges Reservoir area in northeast Chongqing.(2) Global spatial autocorrelation Moran’s I values presented a decreasing and then increasing trend,but they were under agglomeration state on the whole,and presented high-value agglomeration state. Local spatial autocorrelation showed that high-value agglomeration regions were mainly located in the main urban areas and regions around the main urban areas,while low-value agglomeration regions were mainly located in the southeast and northeast areas of Chongqing,with certain spatial path dependence features.