基于承载关系的合肥市土地利用碳排放效应分析

An analysis of land use and carbon emission in Hefei city based on carrying relationship

在碳排放核算的基础上,构建了土地利用类型与碳排放核算项目之间的承载关系,并以合肥市为例,从强度、贡献率和碳汇增减3个方面分析土地利用碳排放效应,以揭示土地利用变化对碳排放的深刻影响。研究结果表明:(1)1995-2012年,合肥市净碳排放量由275.54万t增加到1537.33万t,能源消费是第一大碳源,且只有能源消费的碳排放占比逐年增长;(2)陆地生态系统中的各用地类型碳吸收强度基本稳定,城镇工矿用地的碳排放强度远高于其他建设用地类型;(3)对合肥市碳排放贡献明显的是耕地(为负)、城镇工矿用地(为正)和农村居民点(为正);(4)在土地利用变化过程中,耕地转为城镇工矿用地是碳汇损失最重要的原因。因此,在碳源控制上,以能源消费为抓手是抑制碳排放的有效途径;在土地管理上,严格控制城镇工矿用地扩展,尤其是占用耕地,是增加碳汇、减少碳排放的关键。

The relationship between land use types and carbon emission was established based on the carbonemission calculation in Hefei. The purpose of this research was to reveal the profound impact of land use changeon carbon emission including emission intensity, the contribution rate and carbon sink increase or decrease. Theresults indicate： （1） from 1995 to 2012, Hefei＇s net carbon emission increased from 2.76 million tons to 15.37 mil-lion tons with the energy consumption being the largest emission source and the energy consumption＇s ratio wasincreasing year by year; （2） the carbon absorption intensity of various land use types in the terrestrial ecosystemremained stable. The cultivated land is the most important carbon sink land use type. The carbon emission inten-sity of urban industrial and mining land was much higher than other types of construction land; （3） the obviouscontribution of land use types to carbon emission in Hefei was cultivated land （negative）, urban industrial andmining land （positive） and rural residential areas （positive）; （4） during the course of land use change, the conver-sion of cultivated land to urban industrial and mining land was the main cause of carbon sink loss. In Conclusion,controlling energy consumption is an effective means of decreasing carbon emission. For land management,strictly controlling the extension of urban industrial and mining ＇land, especially reducing the occupation of culti-vated land, is the key to the increase of carbon sink and reduction of carbon emission.