安徽省会经济圈土地利用变化的碳排放效益

土地利用变化是影响碳排放的重要因素。利用1997和2007年土地利用类型数据,采用碳排放评价模型,对安徽省会经济圈碳排放效益进行评价,并估算碳排放生态补偿标准。研究结果显示:①1997-2007年间碳排放总量增加1 049.92×10⁴ t,年均增长14.4%;②2007年经济圈内地均建设用地碳排放强度和地均碳排放强度分别为1997年的2.41倍、 2.18倍,1997和2007年,碳排放强度指数值都是合肥市>巢湖市>六安市;③经济圈内各县(区)地均碳排放强度差异显著,建设用地平均碳排放强度前3位的是合肥市区、 霍山县、 金寨县;④据中国造林成本的价格估算,合肥、 巢湖、 六安3市的碳汇补偿增加量分别为:21.83×10⁸、 4.31×10⁸、 2.48×10⁸元,县域生态补偿额差异显著;⑤土地利用结构、 产业结构与碳排放量存在一定的关系。从碳排放效益和生态补偿的角度,提出减少碳排放的途径。

Effects of Carbon Emission by Land Use Patterns in Hefei’s Economic Circle of Anhui Province

Land use change is an important factor for carbon emission.According to the assessment model and by using the Landsat TM data separately acquired in 1997 and 2007 on the economic circle of Hefei,the provincial capital of Anhui,the authors utilized data of land use types such as cultivated land,woodland,grassland and land for construction in 1997 and 2007 to calculate carbon emissions and the compensation standard based on price of fixation carbon dioxide.The results shows: 1) Carbon emissions greatly varied over different land use types,in which the land for construction and cultivated land were considered as two major carbon sources.Woodland and grassland were two major carbon sinks.Carbon emissions were found to increase by 14.4% per year over the entire economic circle of Hefiei from 1997 to 2007.Carbon emissions increased most quickly in the city,with an average annual growth rate of 32.3% during the ten years.With more impacts of human activities,carbon emission from land for construction was the highest,increased from 7.4587 million tons in 1997 to 17.9409 million tons in 2007.However,carbon sink maintained generally stable during this period.2) Two indexes describing carbon emissions,i.e.,carbon emission per unit area of land and carbon emission per unit area of construction land,were proposed.These two indexes could better reflect carbon emission intensity from 1997 to 2007 and the differences among the regions.Compared with carbon emission intensity in 1997,the two indexes increased by 1.18 and 1.41 times in 2007,respectively.Carbon emissions peaked in Hefei city,and showed a relatively higher level in Chaohu city and a low level in Lu’an city,and the index of carbon emission per unit area of land and construction land indicated the same changing trend.3) Carbon emission per unit area of land was markedly different in 15 counties or urban areas,and the three largest ones per unit area of construction land are urban area of Hefei city,Huoshan and Jinzhai counties.4) On the basis of carbon emission and price of fixation carbon dioxide over the provincial city economic circle during the period 1997-2007,the value of the standard for ecological compensation in three cities was estimated.Based on average cost of tree planting in China,an increasing amount of the compensation standard for the three cities was 2.183,0.431 and 0.248 billion yuan respectively,and the amount of compensation standard was different among counties or urban areas.5)There was certain relationship between land use structure and carbon emissions.Some suggestions for reducing carbon emissions were put forward.