长江三角洲地区城市二氧化碳排放特征研究

Analysis of the CO2Emission Performance of Urban Areas in Yangtze River Delta Region

自下而上基于点排放源建立长江三角洲地区1 km CO2排放空间网格数据,以第五次全国人口普查方法确定城市边界,研究长江三角洲地区真正城市的CO2排放特征。结果表明,长江三角洲地区的CO2排放的空间特征受典型城市驱动和影响。上海是整个长江三角洲地区的排放中心,上海的城市边界和城市排放结构与上海区域基本一致;江苏和浙江的城市直接排放分别占各省直接排放的47.05%和36.96%。两省的城市人均CO2排放水平都低于农村和整个区域人均CO2排放水平。这种现象和发达国家城市与郊区、农村的排放比较特征一致,说明在经济较为发达的省份,随着城市化和城市产业结构的合理与成熟,城市排放效率会优于非城市地区的排放效率。长江三角洲地区部分地级市(如苏州市和宁波市等)出现了两个核心排放城市,且彼此排放结构差异很大,而一些城市(如上海和昆山、无锡和张家港等)的城市边界和CO2排放在空间上已经联接成片,构成新的城市排放中心。长江三角洲地区的城市整体CO2排放增长速度要快于城市人口的增长速度,城市人口增加1%,则城市总CO2排放约增加1.35%,说明随着城市规模的增加,城市CO2排放效率呈下降趋势。这种整体态势主要是长江三角洲地区的城市人口规模差异较大,众多城市发育不成熟造成的。低于100万人口的城市,其人均排放水平波动很大,当人口规模超过了100万,城市人均排放水平基本都稳定在10.00 t/人以下,而且城市之间差异较小。

The CO2 emission performance of urban areas in Yangtze River Delta region are analyzed based on 1 km gridded CO2 emissiondata which is built bottom-up by point emission sources and urban boundaries defined by the Fifth National Population Census. The spatial feature of CO2 emissions in Yangtze River Delta region were driven and affected by certain key urban areas.Shanghai is the emission center of this Delta region,and its urban area boundary and emission structure are basically consistent with Shanghai administrative region. The direct emissions of urban areas in Jiangsu and Zhejiang provinces accounted for 47. 05% and36. 96% of the direct emissions of their respective provinces. The per capita emissions of urban areas in these two provinces were lower than rural and regional level of their provinces respectively. The emission comparison results are consistent with what have been found in the developed countries,and indicated that the emission performance in urban areas will be better than that in non-urban areas when urban and economic condition are well developed. There were emerged double emission centers in some prefecture-level regions（ e. g.,Suzhou region and Ningbo region）,while some urban areas（ e. g.,Shanghai and Kunshan,Wuxi and Zhangjiagang） belonging to different prefecture-level regions have merged together. The growth rate of CO2 emission were quicker than the growth rate of population in the urban areas of the Yangtze River Delta region,where a 1% increase in population size is associated with a nearly proportional increase in CO2 emission of 1. 35%. This generally implies that the CO2 emission performance will degrade with the size of urban area increase. The main reason is the high variations of population size and development level of urban areas. The per capita emissions varied widely among urban areas when their population size is lower than 1 million,and keep stable and below 10. 00 t / person when population size is larger than 1 million.