城镇景观格局对区域碳排放影响及其差别化管控研究

Effect of urban landscape pattern on regional carbon emissions and its differential regulation

建设低碳城市作为可持续发展的重要议题在国内外受到广泛关注,开展城镇景观格局对区域CO_2排放影响及其差别化管制研究对建设低碳城市尤为重要。当前我国缺乏完整的、可信度高的CO_2排放基础数据,地级市尺度上的CO_2排放时空特征及其驱动机制研究非常匮乏。论文基于CHRED数据库的2005年和2012年全国281个地级市CO_2排放数据,结合相应年度的土地利用覆被数据,分析全国及区域(东部、中部、西部)城镇景观格局及其CO_2排放的区域特征,从结构(城镇用地比例)和布局(斑块密度、最大斑块指数、平均最近距离)两方面,实证检验城镇景观格局对区域CO_2排放的影响,最后提出基于碳减排的区域差别化管制政策。研究表明:(1)城镇用地占比、斑块密度、集聚性在空间上呈现出"东高西低"的特征;除了西部地区的集聚性呈缩小趋势外,其他指标均呈现出扩大趋势。(2)西部地区城镇用地占比与地均CO_2排放呈正相关性;中部地区城镇用地平均最近距离与地均CO_2排放呈负相关性;东部、中部地区最大斑块指数与地均CO_2排放呈正相关性。不同区域的城镇景观格局对CO_2排放的影响机制不同,因而应当对城市发展实施差别化管控:东部地区应采取"多核心"的城市发展策略以降低区域CO_2排放水平;中部地区在采用"多核心"的发展策略的同时要兼顾集聚性,发挥其集聚效应;西部地区要显化其全国的生态屏障功能,更加严格地控制建设用地面积,避免城市无序扩张。

The construction of‘Low-carbon Cities’,as an important issue of sustainable development,has received extensive attention at home and abroad.The impact of urban landscape pattern on regional carbon emission and differential regulation are particularly important for the construction of‘Low-carbon Cities’.At present,the study on the spatial and temporal characteristics of carbon emission and its driving mechanism is very scarce because of lacking complete and credible carbon emission data in China.Based on the carbon emission data of 281 prefecture-level cities in 2005 and 2012,the paper analyzed the regional characteristics of the urban landscape pattern and the carbon emission in the whole country,eastern China,central China and western China,respectively.The CHRED database is employed.From the perspective of structure(urban land ratio)and layout(urban land patches density,maximum urban land patch index,the average nearest-neighbor distance for urban land patches),empirical test of the impact of urban landscape pattern on regional carbon emissions was conducted.Finally,regional differential regulation policies were proposed based on‘carbon emission reduction’.The results showed that:First,urban land-use ratio,patch density,agglomeration of urban land showed the‘East High-West Low’characteristics.In addition to the narrowing trend of agglomeration in the western region,the other indicators showed a widening trend.Second,positive correlation was found between urban land-use ratio and carbon emission in the western region.Negative correlation was found between average recent distance and carbon emission in central China.The maximum patch indexes of the eastern and central regions were positively correlated with carbon emission.Different urban landscape patterns had different influence on carbon emission;therefore,differential regulation should be carried out:Eastern China should take the multi-core strategy for urban development to reduce the carbon emission intensity.Central China should display the accumulative effect combined with the multi-core strategy.While western China should restrict the scale of built-up land to avoid unlimited urban sprawl and strengthen the ecological function.The results of regional carbon emission mechanism provided reference for the establishment of regional differential regulation based on carbon emission reduction.