20年来广东省土地利用碳排放强度与效率空间分异研究

Spatial Differentiation in the Intensity and Efficiency of Carbon Emission from Land Use in Guangdong Province in Past Two Decades

广东省是中国国家级低碳试点省份之一,碳减排是广东省推动社会又好又快发展的迫切需要,也是积极承担经济大省控制温室气体排放责任的战略行动。区域碳排放与土地利用变化密切相关,对土地利用碳排放机理进行深入研究,有利于明确今后省级低碳试点建设工作的方向和重点。为此,以广东省为研究区,采用土地利用地类排放系数法和K-mean聚类法,对广东省1996-2015年土地利用碳排放强度和效率时空变化规律进行研究,结果表明:(1)广东省净碳排放量持续增加,年均增幅6.04%,建设用地是主要碳源,林地是主要碳汇;(2)广东省各区域净碳排放量、耕地与建设用地碳排放量的变化幅度为粤北<粤东和粤西<珠江三角洲,林地碳吸收量变化幅度为粤东和粤西<珠江三角洲<粤北;(3)20 a来随着人均GDP增加,广东省单位GDP碳排放持续下降,土地利用碳排放效益明显提升;(4)以人均碳排放为排放量指标,以单位GDP碳排放为排放效率指标,广东省21个地级市可以分为4类:高排放-中效率(HE-ME)、高排放-低效率(HE-LE)、中排放-低效率(ME-LE)和低排放-高效率(LE-HE)。目前,广东碳减排工作取得一定成效,但碳减排形势仍然严峻,未来应该继续对碳排放强度和效率进行调控,加快转变经济发展方式,着力推进低碳示范省建设。

Guangdong is one of the national trial provinces pursuing low-carbon emission in China.As a major economic province,developing low-carbon economy is an urgent need for Guangdong to promote its socioeconomic quality and shoulder the responsibility for reducing greenhouse gas emission.At regional scale,carbon emission is closely related to land use changes.To to deep into understanding the mechanisms of carbon emission due to land use changes is crucial for developing correct strategy for reducing carbon emission in future.This study analyzed the temporal and spatial variations of carbon emission in Guangdong province from 1996 to 2015 based on land use emission coefficient and the K-mean clustering method.The results showed that Guangdong's net carbon discharge had been rising by on average an annual rate of 6.04%.In terms of the effects of land use on carbon emission,the construction land was the main carbon source whereas forest land was the main carbon sink.Besides,regarding carbon discharge in the past two decades,the northern Guangdong had the least net carbon emission that were mainly from farmland and construction land while the Pearl River Delta had the largest net carbon emission that were mainly from farmland and construction land.As per capita GDP increasing in the past two decades,carbon emission per unit GDP in Guangdong had been declining,indicating that the emission efficiency of land use had significantly been improved.Moreover,the carbon uptake by forest land in eastern and western Guangdong had the least change while the largest change took place in the northern Guangdong.By treating carbon emission per capita as the emission indicator and carbon emission per unit GDP as the efficiency indicator,the 21 prefecture-level cities in Guangdong could be classified into four categories:the high emission-medium efficiency,the high emission-low efficiency,the medium emission-low efficiency,and the low emission-high efficiency group.Although some achievements have been made at present,the situation of carbon emission reduction in Guangdong is still severe.In future,we should continue to regulate the intensity and efficiency of carbon emission,accelerate the transformation of the mode of economic development,and focus on promoting the construction of low-carbon demonstration provinces.